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Sample records for hybrid tension estimation

  1. Rapid cable tension estimation using dynamic and mechanical properties

    Science.gov (United States)

    Martínez-Castro, Rosana E.; Jang, Shinae; Christenson, Richard E.

    2016-04-01

    Main tension elements are critical to the overall stability of cable-supported bridges. A dependable and rapid determination of cable tension is desired to assess the state of a cable-supported bridge and evaluate its operability. A portable smart sensor setup is presented to reduce post-processing time and deployment complexity while reliably determining cable tension using dynamic characteristics extracted from spectral analysis. A self-recording accelerometer is coupled with a single-board microcomputer that communicates wirelessly with a remote host computer. The portable smart sensing device is designed such that additional algorithms, sensors and controlling devices for various monitoring applications can be installed and operated for additional structural assessment. The tension-estimating algorithms are based on taut string theory and expand to consider bending stiffness. The successful combination of cable properties allows the use of a cable's dynamic behavior to determine tension force. The tension-estimating algorithms are experimentally validated on a through-arch steel bridge subject to ambient vibration induced by passing traffic. The tension estimation is determined in well agreement with previously determined tension values for the structure.

  2. An Approach to Evaluate Stability for Cable-Based Parallel Camera Robots with Hybrid Tension-Stiffness Properties

    Directory of Open Access Journals (Sweden)

    Huiling Wei

    2015-12-01

    Full Text Available This paper focuses on studying the effect of cable tensions and stiffness on the stability of cable-based parallel camera robots. For this purpose, the tension factor and the stiffness factor are defined, and the expression of stability is deduced. A new approach is proposed to calculate the hybrid-stability index with the minimum cable tension and the minimum singular value. Firstly, the kinematic model of a cable-based parallel camera robot is established. Based on the model, the tensions are solved and a tension factor is defined. In order to obtain the tension factor, an optimization of the cable tensions is carried out. Then, an expression of the system's stiffness is deduced and a stiffness factor is defined. Furthermore, an approach to evaluate the stability of the cable-based camera robots with hybrid tension-stiffness properties is presented. Finally, a typical three-degree-of-freedom cable-based parallel camera robot with four cables is studied as a numerical example. The simulation results show that the approach is both reasonable and effective.

  3. Computationally fast estimation of muscle tension for realtime bio-feedback.

    Science.gov (United States)

    Murai, Akihiko; Kurosaki, Kosuke; Yamane, Katsu; Nakamura, Yoshihiko

    2009-01-01

    In this paper, we propose a method for realtime estimation of whole-body muscle tensions. The main problem of muscle tension estimation is that there are infinite number of solutions to realize a particular joint torque due to the actuation redundancy. Numerical optimization techniques, e.g. quadratic programming, are often employed to obtain a unique solution, but they are usually computationally expensive. For example, our implementation of quadratic programming takes about 0.17 sec per frame on the musculoskeletal model with 274 elements, which is far from realtime computation. Here, we propose to reduce the computational cost by using EMG data and by reducing the number of unknowns in the optimization. First, we compute the tensions of muscles with surface EMG data based on a biological muscle data, which is a very efficient process. We also assume that their synergists have the same activity levels and compute their tensions with the same model. Tensions of the remaining muscles are then computed using quadratic programming, but the number of unknowns is significantly reduced by assuming that the muscles in the same heteronymous group have the same activity level. The proposed method realizes realtime estimation and visualization of the whole-body muscle tensions that can be applied to sports training and rehabilitation.

  4. Field Evaluation of the System Identification Approach for Tension Estimation of External Tendons

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    Myung-Hyun Noh

    2015-01-01

    Full Text Available Various types of external tendons are considered to verify the applicability of tension estimation method based on the finite element model with system identification technique. The proposed method is applied to estimate the tension of benchmark numerical example, model structure, and field structure. The numerical and experimental results show that the existing methods such as taut string theory and linear regression method show large error in the estimated tension when the condition of external tendon is different with the basic assumption used during the derivation of relationship between tension and natural frequency. However, the proposed method gives reasonable results for all of the considered external tendons in this study. Furthermore, the proposed method can evaluate the accuracy of estimated tension indirectly by comparing the measured and calculated natural frequencies. Therefore, the proposed method can be effectively used for field application of various types of external tendons.

  5. Tension-Compression Fatigue Behavior of Plain Woven Kenaf/Kevlar Hybrid Composites

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    Suhad D. Salman

    2016-02-01

    Full Text Available The applications of hybrid natural/synthetic reinforced polymer composites have been rapidly gaining market share in structural applications due to their remarkable characteristics and the fact that most of the components made of these materials are subjected to cyclic loading. Their fatigue properties have received a lot of attention because predicting their behavior is a challenge due to the effects of the synergies between the fibers. The purpose of this work is to characterize the tension, compression, and tensile-compression fatigue behavior of six layers of Kevlar hybridized with one layer of woven kenaf reinforced epoxy, at a 35% weight fraction. Fatigue tests were carried out and loaded cyclically at 60%, 70%, 80%, and 90% of their ultimate compressive stress. The results give a complete description for tensile and compression properties and could be used to predict fatigue-induced failure mechanisms.

  6. Pengaruh One Direction Pre-Tension pada Reinforcement Fibre terhadap Kekuatan Tarik dan Impact Fibre-Powder Reinforcement Hybrid Composite

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    Gilang Gumilar

    2017-12-01

    Full Text Available Nowadays, industrial manufacturing needs environmentally and friendly material and has special properties which are difficult to obtain from the metal material. Composite is one of the alternative materials that can be used to meet those needs. A structural composite material consisting of a combination of two or more elements bonded material at the macroscopic level. This study was conducted to determine the effect of pre-tension one direction on a hybrid composite reinforcement against tensile strength and impact strength. Composite materials prepared by C-Glass fiber types woven rovings, coconut shell powder and vinyl ester resin. manufacturing composite using hand lay-up methods. The variation of the tension given 0N, 50N, 100N, 150N, and 200N. A tensile test based on the reference standard ASTM D 3039 while testing the impact based on ASTM D 6110-04. The results were obtained giving tension to the hybrid composite reinforcement increases tensile strength and impact strength of the material. The lowest tensile strength of the composite obtained in 0N treatment (without treatment ranged 71,58N / mm², and the greatest tensile strength is obtained in the pre-tension 200N, ranging from 106.05 N / mm2. As for the lowest impact on specimens obtained without treatment ranges 1,34J / mm2 and provision of pre-tension 200N biggest impact strength values obtained, ranging 15,09J / mm2.

  7. Field Application of Cable Tension Estimation Technique Using the h-SI Method

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    Myung-Hyun Noh

    2015-01-01

    Full Text Available This paper investigates field applicability of a new system identification technique of estimating tensile force for a cable of long span bridges. The newly proposed h-SI method using the combination of the sensitivity updating algorithm and the advanced hybrid microgenetic algorithm can allow not only avoiding the trap of local minimum at initial searching stage but also finding the optimal solution in terms of better numerical efficiency than existing methods. First, this paper overviews the procedure of tension estimation through a theoretical formulation. Secondly, the validity of the proposed technique is numerically examined using a set of dynamic data obtained from benchmark numerical samples considering the effect of sag extensibility and bending stiffness of a sag-cable system. Finally, the feasibility of the proposed method is investigated through actual field data extracted from a cable-stayed Seohae Bridge. The test results show that the existing methods require precise initial data in advance but the proposed method is not affected by such initial information. In particular, the proposed method can improve accuracy and convergence rate toward final values. Consequently, the proposed method can be more effective than existing methods in terms of characterizing the tensile force variation for cable structures.

  8. Structural design significance of tension-tension fatigue data on composites

    Science.gov (United States)

    Grimes, G. C.

    1977-01-01

    Constant cycle tension-tension fatigue and related static tension data have been generated on six single composite material/orientation combinations and twenty-one hybrid composite material/orientation combinations. Anomalies are related to the temperature rise and stopped interval creep, whereas endurance limit stresses (runouts) are associated with static proportional limit values, when they occur, and internal damage. The significance of these room temperature-dry data on the design allowables and weight of aerodynamic structueres is discussed. Such structures are helicopter rotor blades and wing and horizontal stabilizer lower surfaces. Typical criteria for turning these data into preliminary allowables are shown, as are examples of such allowables developed from the data. These values are then compared to those that might be used if the structures were made of metal.

  9. Feasibility Study on Tension Estimation Technique for Hanger Cables Using the FE Model-Based System Identification Method

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    Kyu-Sik Park

    2015-01-01

    Full Text Available Hanger cables in suspension bridges are partly constrained by horizontal clamps. So, existing tension estimation methods based on a single cable model are prone to higher errors as the cable gets shorter, making it more sensitive to flexural rigidity. Therefore, inverse analysis and system identification methods based on finite element models are suggested recently. In this paper, the applicability of system identification methods is investigated using the hanger cables of Gwang-An bridge. The test results show that the inverse analysis and systemic identification methods based on finite element models are more reliable than the existing string theory and linear regression method for calculating the tension in terms of natural frequency errors. However, the estimation error of tension can be varied according to the accuracy of finite element model in model based methods. In particular, the boundary conditions affect the results more profoundly when the cable gets shorter. Therefore, it is important to identify the boundary conditions through experiment if it is possible. The FE model-based tension estimation method using system identification method can take various boundary conditions into account. Also, since it is not sensitive to the number of natural frequency inputs, the availability of this system is high.

  10. Estimation of the Critical Temperatures of Some More Deep Eutectic Solvents from Their Surface Tensions

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    Yizhak Marcus

    2018-01-01

    Full Text Available The critical temperatures of two dozen deep eutectic solvents, for only some of which these have been estimated previously, were estimated from the temperature dependences of their surface tensions and densities available in the literature according to the Eötvös and the Guggenheim expressions.

  11. Novel method for the simultaneous estimation of density and surface tension of liquids

    International Nuclear Information System (INIS)

    Thirunavukkarasu, G.; Srinivasan, G.J.

    2003-01-01

    The conventional Hare's apparatus generally used for the determination of density of liquids has been modified by replacing its vertical arms (glass tubes) with capillary tubes of 30 cm length and 0.072 cm diameter. When the columns of liquids are drawn through the capillary tubes with reduced pressure at the top of the liquid columns and kept at equilibrium with the atmospheric pressure acting on the liquid surface outside the capillary tubes, the downward pressure due to gravity of the liquid columns has to be coupled with the pressure arising due to the effect of surface tension of the liquids. A fresh expression for the density and surface tension of liquids has been arrived at while equating the pressure balancing system for the two individual liquid columns of the modified Hare's apparatus. The experimental results showed that the proposed method is precise and accurate in the simultaneous estimation of density and surface tension of liquids, with an error of less than 5%

  12. Stochastic linear hybrid systems: Modeling, estimation, and application

    Science.gov (United States)

    Seah, Chze Eng

    Hybrid systems are dynamical systems which have interacting continuous state and discrete state (or mode). Accurate modeling and state estimation of hybrid systems are important in many applications. We propose a hybrid system model, known as the Stochastic Linear Hybrid System (SLHS), to describe hybrid systems with stochastic linear system dynamics in each mode and stochastic continuous-state-dependent mode transitions. We then develop a hybrid estimation algorithm, called the State-Dependent-Transition Hybrid Estimation (SDTHE) algorithm, to estimate the continuous state and discrete state of the SLHS from noisy measurements. It is shown that the SDTHE algorithm is more accurate or more computationally efficient than existing hybrid estimation algorithms. Next, we develop a performance analysis algorithm to evaluate the performance of the SDTHE algorithm in a given operating scenario. We also investigate sufficient conditions for the stability of the SDTHE algorithm. The proposed SLHS model and SDTHE algorithm are illustrated to be useful in several applications. In Air Traffic Control (ATC), to facilitate implementations of new efficient operational concepts, accurate modeling and estimation of aircraft trajectories are needed. In ATC, an aircraft's trajectory can be divided into a number of flight modes. Furthermore, as the aircraft is required to follow a given flight plan or clearance, its flight mode transitions are dependent of its continuous state. However, the flight mode transitions are also stochastic due to navigation uncertainties or unknown pilot intents. Thus, we develop an aircraft dynamics model in ATC based on the SLHS. The SDTHE algorithm is then used in aircraft tracking applications to estimate the positions/velocities of aircraft and their flight modes accurately. Next, we develop an aircraft conformance monitoring algorithm to detect any deviations of aircraft trajectories in ATC that might compromise safety. In this application, the SLHS

  13. Monte Carlo estimates of interfacial tension in the two-dimensional Ising model from non-equilibrium methods

    International Nuclear Information System (INIS)

    Híjar, Humberto; Sutmann, Godehard

    2008-01-01

    Non-equilibrium methods for estimating free energy differences are used in order to calculate the interfacial tension between domains with opposite magnetizations in two-dimensional Ising lattices. Non-equilibrium processes are driven by changing the boundary conditions for two opposite sides of the lattice from periodic to antiperiodic and vice versa. This mechanism, which promotes the appearance and disappearance of the interface, is studied by means of Monte Carlo simulations performed at different rates and using different algorithms, thus allowing for testing the applicability of non-equilibrium methods for processes driven far from or close to equilibrium. Interfaces in lattices with different widths and heights are studied and the interface tension as a function of these quantities is obtained. It is found that the estimates of the interfacial tension from non-equilibrium procedures are in good agreement with previous reports as well as with exact results. The efficiency of the different procedures used is analyzed and the dynamics of the interface under these perturbations is briefly discussed. A method for determining the efficiency of non-equilibrium methods as regards thermodynamic perturbation is also presented. It is found that for all cases studied, the Crooks non-equilibrium method for estimating free energy differences is the most efficient one

  14. Vehicle Sideslip Angle Estimation Based on Hybrid Kalman Filter

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    Jing Li

    2016-01-01

    Full Text Available Vehicle sideslip angle is essential for active safety control systems. This paper presents a new hybrid Kalman filter to estimate vehicle sideslip angle based on the 3-DoF nonlinear vehicle dynamic model combined with Magic Formula tire model. The hybrid Kalman filter is realized by combining square-root cubature Kalman filter (SCKF, which has quick convergence and numerical stability, with square-root cubature based receding horizon Kalman FIR filter (SCRHKF, which has robustness against model uncertainty and temporary noise. Moreover, SCKF and SCRHKF work in parallel, and the estimation outputs of two filters are merged by interacting multiple model (IMM approach. Experimental results show the accuracy and robustness of the hybrid Kalman filter.

  15. Estimation of cables’ tension of cable-stayed footbridge using measured natural frequencies

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    Jakiel Przemysław

    2017-01-01

    Full Text Available This paper presents analysis of cables’ tension of steel cable-stayed footbridge using their field-test natural frequencies. A vibration method is usually used for the measured cable tension during the construction of cable systems stiffened with inclined cables. Practical formulas for the vibration method applied herein, mainly based on cable-sag and vertical angle effects (a survey measurement, have been verified on the one-tower steel cable-stayed bridge. The bridge is situated in Sieradz (Poland and it was the structure with the longest span concerning all the cable-stayed bridges in Poland until 1999. The obtained cable axial forces for estimated natural frequencies of low- and high-order modes are verified using FEM models. The final conclusions drawn on the basis of conducted studies can be useful for technical diagnosis, monitoring programs and repair works of similar class of cable-stayed bridges.

  16. Manifold absolute pressure estimation using neural network with hybrid training algorithm.

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    Mohd Taufiq Muslim

    Full Text Available In a modern small gasoline engine fuel injection system, the load of the engine is estimated based on the measurement of the manifold absolute pressure (MAP sensor, which took place in the intake manifold. This paper present a more economical approach on estimating the MAP by using only the measurements of the throttle position and engine speed, resulting in lower implementation cost. The estimation was done via two-stage multilayer feed-forward neural network by combining Levenberg-Marquardt (LM algorithm, Bayesian Regularization (BR algorithm and Particle Swarm Optimization (PSO algorithm. Based on the results found in 20 runs, the second variant of the hybrid algorithm yields a better network performance than the first variant of hybrid algorithm, LM, LM with BR and PSO by estimating the MAP closely to the simulated MAP values. By using a valid experimental training data, the estimator network that trained with the second variant of the hybrid algorithm showed the best performance among other algorithms when used in an actual retrofit fuel injection system (RFIS. The performance of the estimator was also validated in steady-state and transient condition by showing a closer MAP estimation to the actual value.

  17. Manifold absolute pressure estimation using neural network with hybrid training algorithm.

    Science.gov (United States)

    Muslim, Mohd Taufiq; Selamat, Hazlina; Alimin, Ahmad Jais; Haniff, Mohamad Fadzli

    2017-01-01

    In a modern small gasoline engine fuel injection system, the load of the engine is estimated based on the measurement of the manifold absolute pressure (MAP) sensor, which took place in the intake manifold. This paper present a more economical approach on estimating the MAP by using only the measurements of the throttle position and engine speed, resulting in lower implementation cost. The estimation was done via two-stage multilayer feed-forward neural network by combining Levenberg-Marquardt (LM) algorithm, Bayesian Regularization (BR) algorithm and Particle Swarm Optimization (PSO) algorithm. Based on the results found in 20 runs, the second variant of the hybrid algorithm yields a better network performance than the first variant of hybrid algorithm, LM, LM with BR and PSO by estimating the MAP closely to the simulated MAP values. By using a valid experimental training data, the estimator network that trained with the second variant of the hybrid algorithm showed the best performance among other algorithms when used in an actual retrofit fuel injection system (RFIS). The performance of the estimator was also validated in steady-state and transient condition by showing a closer MAP estimation to the actual value.

  18. Attempts at estimating mixed venous carbon dioxide tension by the single-breath method.

    Science.gov (United States)

    Ohta, H; Takatani, O; Matsuoka, T

    1989-01-01

    The single-breath method was originally proposed by Kim et al. [1] for estimating the blood carbon dioxide tension and cardiac output. Its reliability has not been proven. The present study was undertaken, using dogs, to compare the mixed venous carbon dioxide tension (PVCO2) calculated by the single-breath method with the PVCO2 measured in mixed venous blood, and to evaluate the influence of variations in the exhalation duration and the volume of expired air usually discarded from computations as the deadspace. Among the exhalation durations of 15, 30 and 45 s tested, the 15 s duration was found to be too short to obtain an analyzable O2-CO2 curve, but at either 30 or 45 s, the calculated values of PVCO2 were comparable to the measured PVCO2. A significant agreement between calculated and measured PVCO2 was obtained when the expired gas with PCO2 less than 22 Torr was considered as deadspace gas.

  19. On relation between the quark-gluon bag surface tension and the colour tube string tension

    International Nuclear Information System (INIS)

    Bugaev, K.A.; Zinovjev, G.M.

    2010-01-01

    We revisit the bag phenomenology of deconfining phase transition aiming to replenish it by introducing systematically the bag surface tension. Comparing the free energies of such bags and the strings confining the static quark-antiquark pair, we express the string tension in terms of the bag surface tension and the bulk pressure in order to estimate the bag characteristics using the lattice QCD (LQCD) data. Our analysis of the bag entropy density demonstrates that the surface tension coefficient is amazingly negative at the cross-over (continuous transition). The approach developed allows us to naturally account for an origin of a pronounced maximum (observed in the LQCD studies) in the behaviour of heavy quark-antiquark pair entropy. The vicinity of the (tri-)critical endpoint is also analyzed to clarify the meaning of vanishing surface tension coefficient.

  20. Parameter Estimation Analysis for Hybrid Adaptive Fault Tolerant Control

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    Eshak, Peter B.

    Research efforts have increased in recent years toward the development of intelligent fault tolerant control laws, which are capable of helping the pilot to safely maintain aircraft control at post failure conditions. Researchers at West Virginia University (WVU) have been actively involved in the development of fault tolerant adaptive control laws in all three major categories: direct, indirect, and hybrid. The first implemented design to provide adaptation was a direct adaptive controller, which used artificial neural networks to generate augmentation commands in order to reduce the modeling error. Indirect adaptive laws were implemented in another controller, which utilized online PID to estimate and update the controller parameter. Finally, a new controller design was introduced, which integrated both direct and indirect control laws. This controller is known as hybrid adaptive controller. This last control design outperformed the two earlier designs in terms of less NNs effort and better tracking quality. The performance of online PID has an important role in the quality of the hybrid controller; therefore, the quality of the estimation will be of a great importance. Unfortunately, PID is not perfect and the online estimation process has some inherited issues; the online PID estimates are primarily affected by delays and biases. In order to ensure updating reliable estimates to the controller, the estimator consumes some time to converge. Moreover, the estimator will often converge to a biased value. This thesis conducts a sensitivity analysis for the estimation issues, delay and bias, and their effect on the tracking quality. In addition, the performance of the hybrid controller as compared to direct adaptive controller is explored. In order to serve this purpose, a simulation environment in MATLAB/SIMULINK has been created. The simulation environment is customized to provide the user with the flexibility to add different combinations of biases and delays to

  1. PARAMETER ESTIMATION OF THE HYBRID CENSORED LOMAX DISTRIBUTION

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    Samir Kamel Ashour

    2010-12-01

    Full Text Available Survival analysis is used in various fields for analyzing data involving the duration between two events. It is also known as event history analysis, lifetime data analysis, reliability analysis or time to event analysis. One of the difficulties which arise in this area is the presence of censored data. The lifetime of an individual is censored when it cannot be exactly measured but partial information is available. Different circumstances can produce different types of censoring. The two most common censoring schemes used in life testing experiments are Type-I and Type-II censoring schemes. Hybrid censoring scheme is mixture of Type-I and Type-II censoring scheme. In this paper we consider the estimation of parameters of Lomax distribution based on hybrid censored data. The parameters are estimated by the maximum likelihood and Bayesian methods. The Fisher information matrix has been obtained and it can be used for constructing asymptotic confidence intervals.

  2. Multistage optimal PMU placement for hybrid state estimation

    DEFF Research Database (Denmark)

    Hazra, J.; Das, Kaushik; Roy, B. K. S.

    2017-01-01

    placed by the proposed method are used in developing a hybrid state estimator (HSE). The HSE estimates the voltage phasor at all the buses of a power system with a limited numbers of PMUs in steady state as well as in the presence of disturbances even in that part of network which is unobservable through...... PMUs. Performance of the proposed phased installation scheme for HSE is evaluated on the number of standard test system and the simulation results shows an improvement in the accuracy of the estimated states as compared to the existing methods in the literature....

  3. Efficient synthesis of tension modulation in strings and membranes based on energy estimation.

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    Avanzini, Federico; Marogna, Riccardo; Bank, Balázs

    2012-01-01

    String and membrane vibrations cannot be considered as linear above a certain amplitude due to the variation in string or membrane tension. A relevant special case is when the tension is spatially constant and varies in time only in dependence of the overall string length or membrane surface. The most apparent perceptual effect of this tension modulation phenomenon is the exponential decay of pitch in time. Pitch glides due to tension modulation are an important timbral characteristic of several musical instruments, including the electric guitar and tom-tom drum, and many ethnic instruments. This paper presents a unified formulation to the tension modulation problem for one-dimensional (1-D) (string) and two-dimensional (2-D) (membrane) cases. In addition, it shows that the short-time average of the tension variation, which is responsible for pitch glides, is approximately proportional to the system energy. This proportionality allows the efficient physics-based sound synthesis of pitch glides. The proposed models require only slightly more computational resources than linear models as opposed to earlier tension-modulated models of higher complexity. © 2012 Acoustical Society of America.

  4. 4D Trajectory Estimation for Air Traffic Control Automation System Based on Hybrid System Theory

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    Xin-Min Tang

    2012-03-01

    Full Text Available To resolve the problem of future airspace management under great traffic flow and high density condition, 4D trajectory estimation has become one of the core technologies of the next new generation air traffic control automation system. According to the flight profile and the dynamics models of different aircraft types under different flight conditions, a hybrid system model that switches the aircraft from one flight stage to another with aircraft state changing continuously in one state is constructed. Additionally, air temperature and wind speed are used to modify aircraft true airspeed as well as ground speed, and the hybrid system evolution simulation is used to estimate aircraft 4D trajectory. The case study proves that 4D trajectory estimated through hybrid system model can image the flight dynamic states of aircraft and satisfy the needs of the planned flight altitude profile.KEY WORDSair traffic management, 4D trajectory estimation, hybrid system model, aircraft dynamic model

  5. Estimates of hybridization between two species of catostomids in the Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Dauble, D.D.; Buschbom, R.L.

    1981-01-01

    Extent of hybridization is described between two sympatric catostomids, Catostomus macrocheilus and C. columbianus, from the Hanford Reach of the Columbia River, southeastern Washington state. Estimated percentage of hybrids based on presence of intermediate meristic characters ranged from 12.4 to 14.6% of the total sucker population. Discriminant function analysis reduced subjective variability and lowered estimates of hybridization to 3.0 to 7.1%. Principal component analysis also provided evidence that the suspected hybrids were intermediate between populations of C. macrocheilus and C. columbianus. Meristic characters contributed most to all methods of treatment, with number of lateral line scales the best single criterion for species separation. Any analysis of closely related species would benefit from examination of offspring from artificial crosses and from knowledge of allopatric population characteristics. Breakdown of isolating mechanisms leading to C. macrocheilus X C. columbianus crosses may result from overlap in spawning time and incomplete habitat segregation. Morphological and coloration differences at spawning may provide a basis for species recognition, thus providing some degree of ethological isolation.

  6. The estimation of energy efficiency for hybrid refrigeration system

    International Nuclear Information System (INIS)

    Gazda, Wiesław; Kozioł, Joachim

    2013-01-01

    Highlights: ► We present the experimental setup and the model of the hybrid cooling system. ► We examine impact of the operating parameters of the hybrid cooling system on the energy efficiency indicators. ► A comparison of the final and the primary energy use for a combination of the cooling systems is carried out. ► We explain the relationship between the COP and PER values for the analysed cooling systems. -- Abstract: The concept of the air blast-cryogenic freezing method (ABCF) is based on an innovative hybrid refrigeration system with one common cooling space. The hybrid cooling system consists of a vapor compression refrigeration system and a cryogenic refrigeration system. The prototype experimental setup for this method on the laboratory scale is discussed. The application of the results of experimental investigations and the theoretical–empirical model makes it possible to calculate the cooling capacity as well as the final and primary energy use in the hybrid system. The energetic analysis has been carried out for the operating modes of the refrigerating systems for the required temperatures inside the cooling chamber of −5 °C, −10 °C and −15 °C. For the estimation of the energy efficiency the coefficient of performance COP and the primary energy ratio PER for the hybrid refrigeration system are proposed. A comparison of these coefficients for the vapor compression refrigeration and the cryogenic refrigeration system has also been presented.

  7. Low physiologic oxygen tensions reduce proliferation and differentiation of human multipotent mesenchymal stromal cells

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    Handgretinger Rupert

    2010-01-01

    Full Text Available Abstract Background Human multipotent mesenchymal stromal cells (MSC can be isolated from various tissues including bone marrow. Here, MSC participate as bone lining cells in the formation of the hematopoietic stem cell niche. In this compartment, the oxygen tension is low and oxygen partial pressure is estimated to range from 1% to 7%. We analyzed the effect of low oxygen tensions on human MSC cultured with platelet-lysate supplemented media and assessed proliferation, morphology, chromosomal stability, immunophenotype and plasticity. Results After transferring MSC from atmospheric oxygen levels of 21% to 1%, HIF-1α expression was induced, indicating efficient oxygen reduction. Simultaneously, MSC exhibited a significantly different morphology with shorter extensions and broader cell bodies. MSC did not proliferate as rapidly as under 21% oxygen and accumulated in G1 phase. The immunophenotype, however, was unaffected. Hypoxic stress as well as free oxygen radicals may affect chromosomal stability. However, no chromosomal abnormalities in human MSC under either culture condition were detected using high-resolution matrix-based comparative genomic hybridization. Reduced oxygen tension severely impaired adipogenic and osteogenic differentiation of human MSC. Elevation of oxygen from 1% to 3% restored osteogenic differentiation. Conclusion Physiologic oxygen tension during in vitro culture of human MSC slows down cell cycle progression and differentiation. Under physiological conditions this may keep a proportion of MSC in a resting state. Further studies are needed to analyze these aspects of MSC in tissue regeneration.

  8. Using the surface tension to estimate the condensate density of superfluid 4He

    International Nuclear Information System (INIS)

    Campbell, L.J.

    1983-01-01

    Distortion of the condensate wavefunction at the free surface of superfluid 4 He contributes to the surface tension in proportion to the condensate fraction n 0 (T). Using this to resolve the present discrepancy between the measured and predicted temperature dependencies of the surface tension gives n 0 (T) in good agreement with results from neutron and x-ray scattering measurements. This picture is also consistent with the measured 3 He- 4 He interfacial tension

  9. A novel approach to pipeline tensioner modeling

    Energy Technology Data Exchange (ETDEWEB)

    O' Grady, Robert; Ilie, Daniel; Lane, Michael [MCS Software Division, Galway (Ireland)

    2009-07-01

    As subsea pipeline developments continue to move into deep and ultra-deep water locations, there is an increasing need for the accurate prediction of expected pipeline fatigue life. A significant factor that must be considered as part of this process is the fatigue damage sustained by the pipeline during installation. The magnitude of this installation-related damage is governed by a number of different agents, one of which is the dynamic behavior of the tensioner systems during pipe-laying operations. There are a variety of traditional finite element methods for representing dynamic tensioner behavior. These existing methods, while basic in nature, have been proven to provide adequate forecasts in terms of the dynamic variation in typical installation parameters such as top tension and sagbend/overbend strain. However due to the simplicity of these current approaches, some of them tend to over-estimate the frequency of tensioner pay out/in under dynamic loading. This excessive level of pay out/in motion results in the prediction of additional stress cycles at certain roller beds, which in turn leads to the prediction of unrealistic fatigue damage to the pipeline. This unwarranted fatigue damage then equates to an over-conservative value for the accumulated damage experienced by a pipeline weld during installation, and so leads to a reduction in the estimated fatigue life for the pipeline. This paper describes a novel approach to tensioner modeling which allows for greater control over the velocity of dynamic tensioner pay out/in and so provides a more accurate estimation of fatigue damage experienced by the pipeline during installation. The paper reports on a case study, as outlined in the proceeding section, in which a comparison is made between results from this new tensioner model and from a more conventional approach. The comparison considers typical installation parameters as well as an in-depth look at the predicted fatigue damage for the two methods

  10. A wireless smart sensor network for automated monitoring of cable tension

    International Nuclear Information System (INIS)

    Sim, Sung-Han; Cho, Soojin; Li, Jian; Jo, Hongki; Park, Jong-Woong; Jung, Hyung-Jo; Spencer Jr, Billie F

    2014-01-01

    As cables are primary load carrying members in cable-stayed bridges, monitoring the tension forces of the cables provides valuable information regarding structural soundness. Incorporating wireless smart sensors with vibration-based tension estimation methods provides an efficient means of autonomous long-term monitoring of cable tensions. This study develops a wireless cable tension monitoring system using MEMSIC’s Imote2 smart sensors. The monitoring system features autonomous operation, sustainable energy harvesting and power consumption, and remote access using the internet. To obtain the tension force, an in-network data processing strategy associated with the vibration-based tension estimation method is implemented on the Imote2-based sensor network, significantly reducing the wireless data transmission and the power consumption. The proposed monitoring system has been deployed and validated on the Jindo Bridge, a cable-stayed bridge located in South Korea. (paper)

  11. A wireless smart sensor network for automated monitoring of cable tension

    Science.gov (United States)

    Sim, Sung-Han; Li, Jian; Jo, Hongki; Park, Jong-Woong; Cho, Soojin; Spencer, Billie F., Jr.; Jung, Hyung-Jo

    2014-02-01

    As cables are primary load carrying members in cable-stayed bridges, monitoring the tension forces of the cables provides valuable information regarding structural soundness. Incorporating wireless smart sensors with vibration-based tension estimation methods provides an efficient means of autonomous long-term monitoring of cable tensions. This study develops a wireless cable tension monitoring system using MEMSIC’s Imote2 smart sensors. The monitoring system features autonomous operation, sustainable energy harvesting and power consumption, and remote access using the internet. To obtain the tension force, an in-network data processing strategy associated with the vibration-based tension estimation method is implemented on the Imote2-based sensor network, significantly reducing the wireless data transmission and the power consumption. The proposed monitoring system has been deployed and validated on the Jindo Bridge, a cable-stayed bridge located in South Korea.

  12. A new method of hybrid frequency hopping signals selection and blind parameter estimation

    Science.gov (United States)

    Zeng, Xiaoyu; Jiao, Wencheng; Sun, Huixian

    2018-04-01

    Frequency hopping communication is widely used in military communications at home and abroad. In the case of single-channel reception, it is scarce to process multiple frequency hopping signals both effectively and simultaneously. A method of hybrid FH signals selection and blind parameter estimation is proposed. The method makes use of spectral transformation, spectral entropy calculation and PRI transformation basic theory to realize the sorting and parameter estimation of the components in the hybrid frequency hopping signal. The simulation results show that this method can correctly classify the frequency hopping component signal, and the estimated error of the frequency hopping period is about 5% and the estimated error of the frequency hopping frequency is less than 1% when the SNR is 10dB. However, the performance of this method deteriorates seriously at low SNR.

  13. Multi-locus estimates of population structure and migration in a fence lizard hybrid zone.

    Directory of Open Access Journals (Sweden)

    Adam D Leaché

    Full Text Available A hybrid zone between two species of lizards in the genus Sceloporus (S. cowlesi and S. tristichus on the Mogollon Rim in Arizona provides a unique opportunity to study the processes of lineage divergence and merging. This hybrid zone involves complex interactions between 2 morphologically and ecologically divergent subspecies, 3 chromosomal groups, and 4 mitochondrial DNA (mtDNA clades. The spatial patterns of divergence between morphology, chromosomes and mtDNA are discordant, and determining which of these character types (if any reflects the underlying population-level lineages that are of interest has remained impeded by character conflict. The focus of this study is to estimate the number of populations interacting in the hybrid zone using multi-locus nuclear data, and to then estimate the migration rates and divergence time between the inferred populations. Multi-locus estimates of population structure and gene flow were obtained from 12 anonymous nuclear loci sequenced for 93 specimens of Sceloporus. Population structure estimates support two populations, and this result is robust to changes to the prior probability distribution used in the Bayesian analysis and the use of spatially-explicit or non-spatial models. A coalescent analysis of population divergence suggests that gene flow is high between the two populations, and that the timing of divergence is restricted to the Pleistocene. The hybrid zone is more accurately described as involving two populations belonging to S. tristichus, and the presence of S. cowlesi mtDNA haplotypes in the hybrid zone is an anomaly resulting from mitochondrial introgression.

  14. A hybrid algorithm combining EKF and RLS in synchronous estimation of road grade and vehicle' mass for a hybrid electric bus

    Science.gov (United States)

    Sun, Yong; Li, Liang; Yan, Bingjie; Yang, Chao; Tang, Gongyou

    2016-02-01

    This paper proposes a novel hybrid algorithm for simultaneously estimating the vehicle mass and road grade for hybrid electric bus (HEB). First, the road grade in current step is estimated using extended Kalman filter (EKF) with the initial state including velocity and engine torque. Second, the vehicle mass is estimated twice, one with EKF and the other with recursive least square (RLS) using the estimated road grade. A more accurate value of the estimated mass is acquired by weighting the trade-off between EKF and RLS. Finally, the road grade and vehicle mass thus obtained are used as the initial states for the next step, and two variables could be decoupled from the nonlinear vehicle dynamics by performing the above procedure repeatedly. Simulation results show that in different starting conditions, the proposed algorithm provides higher accuracy and faster convergence speed, compared with the results using EKF or RLS alone.

  15. Surface tension estimation of high temperature melts of the binary alloys Ag-Au

    Science.gov (United States)

    Dogan, Ali; Arslan, Hüseyin

    2017-11-01

    Surface tension calculation of the binary alloys Ag-Au at the temperature of 1381 K, where Ag and Au have similar electronic structures and their atomic radii are comparable, are carried out in this study using several equations over entire composition range of Au. Apparently, the deviations from ideality of the bulk solutions, such as activities of Ag and Au are small and the maximum excess Gibbs free energy of mixing of the liquid phase is for instance -4500 J/mol at XAu = 0.5. Besides, the results obtained in Ag-Au alloys that at a constant temperature the surface tension increases with increasing composition while the surface tension decreases as the temperature increases for entire composition range of Au. Although data about surface tension of the Ag-Au alloy are limited, it was possible to make a comparison for the calculated results for the surface tension in this study with the available experimental data. Taken together, the average standard error analysis that especially the improved Guggenheim model in the other models gives the best agreement along with the experimental results at temperature 1383 K although almost all models are mutually in agreement with the other one.

  16. Parameter estimation of Lorenz chaotic system using a hybrid swarm intelligence algorithm

    International Nuclear Information System (INIS)

    Lazzús, Juan A.; Rivera, Marco; López-Caraballo, Carlos H.

    2016-01-01

    A novel hybrid swarm intelligence algorithm for chaotic system parameter estimation is present. For this purpose, the parameters estimation on Lorenz systems is formulated as a multidimensional problem, and a hybrid approach based on particle swarm optimization with ant colony optimization (PSO–ACO) is implemented to solve this problem. Firstly, the performance of the proposed PSO–ACO algorithm is tested on a set of three representative benchmark functions, and the impact of the parameter settings on PSO–ACO efficiency is studied. Secondly, the parameter estimation is converted into an optimization problem on a three-dimensional Lorenz system. Numerical simulations on Lorenz model and comparisons with results obtained by other algorithms showed that PSO–ACO is a very powerful tool for parameter estimation with high accuracy and low deviations. - Highlights: • PSO–ACO combined particle swarm optimization with ant colony optimization. • This study is the first research of PSO–ACO to estimate parameters of chaotic systems. • PSO–ACO algorithm can identify the parameters of the three-dimensional Lorenz system with low deviations. • PSO–ACO is a very powerful tool for the parameter estimation on other chaotic system.

  17. Parameter estimation of Lorenz chaotic system using a hybrid swarm intelligence algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Lazzús, Juan A., E-mail: jlazzus@dfuls.cl; Rivera, Marco; López-Caraballo, Carlos H.

    2016-03-11

    A novel hybrid swarm intelligence algorithm for chaotic system parameter estimation is present. For this purpose, the parameters estimation on Lorenz systems is formulated as a multidimensional problem, and a hybrid approach based on particle swarm optimization with ant colony optimization (PSO–ACO) is implemented to solve this problem. Firstly, the performance of the proposed PSO–ACO algorithm is tested on a set of three representative benchmark functions, and the impact of the parameter settings on PSO–ACO efficiency is studied. Secondly, the parameter estimation is converted into an optimization problem on a three-dimensional Lorenz system. Numerical simulations on Lorenz model and comparisons with results obtained by other algorithms showed that PSO–ACO is a very powerful tool for parameter estimation with high accuracy and low deviations. - Highlights: • PSO–ACO combined particle swarm optimization with ant colony optimization. • This study is the first research of PSO–ACO to estimate parameters of chaotic systems. • PSO–ACO algorithm can identify the parameters of the three-dimensional Lorenz system with low deviations. • PSO–ACO is a very powerful tool for the parameter estimation on other chaotic system.

  18. Axisymmetric drop shape analysis for estimating the surface tension of cell aggregates by centrifugation.

    Science.gov (United States)

    Kalantarian, Ali; Ninomiya, Hiromasa; Saad, Sameh M I; David, Robert; Winklbauer, Rudolf; Neumann, A Wilhelm

    2009-02-18

    Biological tissues behave in certain respects like liquids. Consequently, the surface tension concept can be used to explain aspects of the in vitro and in vivo behavior of multicellular aggregates. Unfortunately, conventional methods of surface tension measurement cannot be readily applied to small cell aggregates. This difficulty can be overcome by an experimentally straightforward method consisting of centrifugation followed by axisymmetric drop shape analysis (ADSA). Since the aggregates typically show roughness, standard ADSA cannot be applied and we introduce a novel numerical method called ADSA-IP (ADSA for imperfect profile) for this purpose. To examine the new methodology, embryonic tissues from the gastrula of the frog, Xenopus laevis, deformed in the centrifuge are used. It is confirmed that surface tension measurements are independent of centrifugal force and aggregate size. Surface tension is measured for ectodermal cells in four sample batches, and varies between 1.1 and 7.7 mJ/m2. Surface tension is also measured for aggregates of cells expressing cytoplasmically truncated EP/C-cadherin, and is approximately half as large. In parallel, such aggregates show a reduction in convergent extension-driven elongation after activin treatment, reflecting diminished intercellular cohesion.

  19. Cost Performance Estimating Relationships for Hybrid Electric Vehicle Components

    Science.gov (United States)

    2003-07-31

    Permanent magnet motors are more likely to be used as generators, while AC induction motors are more efficiently used as motors. Inverters/controllers can...than permanent magnet motors . Switched Reluctance motors are also used on hybrid electric vehicles, but are not used as widely as either AC...induction or permanent magnet motors , and are not analyzed here. Methodology The motor estimates are based on power, with kilowatts being the unit of

  20. Origin and cross-century dynamics of an avian hybrid zone.

    Science.gov (United States)

    Morales-Rozo, Andrea; Tenorio, Elkin A; Carling, Matthew D; Cadena, Carlos Daniel

    2017-12-15

    Characterizations of the dynamics of hybrid zones in space and time can give insights about traits and processes important in population divergence and speciation. We characterized a hybrid zone between tanagers in the genus Ramphocelus (Aves, Thraupidae) located in southwestern Colombia. We evaluated whether this hybrid zone originated as a result of secondary contact or of primary differentiation, and described its dynamics across time using spatial analyses of molecular, morphological, and coloration data in combination with paleodistribution modeling. Models of potential historical distributions based on climatic data and genetic signatures of demographic expansion suggested that the hybrid zone likely originated following secondary contact between populations that expanded their ranges out of isolated areas in the Quaternary. Concordant patterns of variation in phenotypic characters across the hybrid zone and its narrow extent are suggestive of a tension zone, maintained by a balance between dispersal and selection against hybrids. Estimates of phenotypic cline parameters obtained using specimens collected over nearly a century revealed that, in recent decades, the zone appears to have moved to the east and to higher elevations, and may have become narrower. Genetic variation was not clearly structured along the hybrid zone, but comparisons between historical and contemporary specimens suggested that temporal changes in its genetic makeup may also have occurred. Our data suggest that the hybrid zone likey resulted from secondary contact between populations. The observed changes in the hybrid zone may be a result of sexual selection, asymmetric gene flow, or environmental change.

  1. Prediction of the optimum hybridization conditions of dot-blot-SNP analysis using estimated melting temperature of oligonucleotide probes.

    Science.gov (United States)

    Shiokai, Sachiko; Kitashiba, Hiroyasu; Nishio, Takeshi

    2010-08-01

    Although the dot-blot-SNP technique is a simple cost-saving technique suitable for genotyping of many plant individuals, optimization of hybridization and washing conditions for each SNP marker requires much time and labor. For prediction of the optimum hybridization conditions for each probe, we compared T (m) values estimated from nucleotide sequences using the DINAMelt web server, measured T (m) values, and hybridization conditions yielding allele-specific signals. The estimated T (m) values were comparable to the measured T (m) values with small differences of less than 3 degrees C for most of the probes. There were differences of approximately 14 degrees C between the specific signal detection conditions and estimated T (m) values. Change of one level of SSC concentrations of 0.1, 0.2, 0.5, and 1.0x SSC corresponded to a difference of approximately 5 degrees C in optimum signal detection temperature. Increasing the sensitivity of signal detection by shortening the exposure time to X-ray film changed the optimum hybridization condition for specific signal detection. Addition of competitive oligonucleotides to the hybridization mixture increased the suitable hybridization conditions by 1.8. Based on these results, optimum hybridization conditions for newly produced dot-blot-SNP markers will become predictable.

  2. Lithium-ion Battery Degradation Assessment and Remaining Useful Life Estimation in Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Nabil Laayouj

    2016-06-01

    Full Text Available Abstract—Prognostic activity deals with prediction of the remaining useful life (RUL of physical systems based on their actual health state and their usage conditions. RUL estimation gives operators a potent tool in decision making by quantifying how much time is left until functionality is lost. In addition, it can be used to improve the characterization of the material proprieties that govern damage propagation for the structure being monitored. RUL can be estimated by using three main approaches, namely model-based, data-driven and hybrid approaches. The prognostics methods used later in this paper are hybrid and data-driven approaches, which employ the Particle Filter in the first one and the autoregressive integrated moving average in the second. The performance of the suggested approaches is evaluated in a comparative study on data collected from lithium-ion battery of hybrid electric vehicle.

  3. Local deformation method for measuring element tension in space deployable structures

    Directory of Open Access Journals (Sweden)

    Belov Sergey

    2017-01-01

    Full Text Available The article describes the local deformation method to determine the tension of cord and thin membrane elements in space deployable structure as antenna reflector. Possible measuring instrument model, analytical and numerical solutions and experimental results are presented. The boundary effects on measurement results of metallic mesh reflector surface tension are estimated. The study case depicting non-uniform reflector surface tension is considered.

  4. Navigation Aiding by a Hybrid Laser-Camera Motion Estimator for Micro Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Jamal Atman

    2016-09-01

    Full Text Available Micro Air Vehicles (MAVs equipped with various sensors are able to carry out autonomous flights. However, the self-localization of autonomous agents is mostly dependent on Global Navigation Satellite Systems (GNSS. In order to provide an accurate navigation solution in absence of GNSS signals, this article presents a hybrid sensor. The hybrid sensor is a deep integration of a monocular camera and a 2D laser rangefinder so that the motion of the MAV is estimated. This realization is expected to be more flexible in terms of environments compared to laser-scan-matching approaches. The estimated ego-motion is then integrated in the MAV’s navigation system. However, first, the knowledge about the pose between both sensors is obtained by proposing an improved calibration method. For both calibration and ego-motion estimation, 3D-to-2D correspondences are used and the Perspective-3-Point (P3P problem is solved. Moreover, the covariance estimation of the relative motion is presented. The experiments show very accurate calibration and navigation results.

  5. Navigation Aiding by a Hybrid Laser-Camera Motion Estimator for Micro Aerial Vehicles.

    Science.gov (United States)

    Atman, Jamal; Popp, Manuel; Ruppelt, Jan; Trommer, Gert F

    2016-09-16

    Micro Air Vehicles (MAVs) equipped with various sensors are able to carry out autonomous flights. However, the self-localization of autonomous agents is mostly dependent on Global Navigation Satellite Systems (GNSS). In order to provide an accurate navigation solution in absence of GNSS signals, this article presents a hybrid sensor. The hybrid sensor is a deep integration of a monocular camera and a 2D laser rangefinder so that the motion of the MAV is estimated. This realization is expected to be more flexible in terms of environments compared to laser-scan-matching approaches. The estimated ego-motion is then integrated in the MAV's navigation system. However, first, the knowledge about the pose between both sensors is obtained by proposing an improved calibration method. For both calibration and ego-motion estimation, 3D-to-2D correspondences are used and the Perspective-3-Point (P3P) problem is solved. Moreover, the covariance estimation of the relative motion is presented. The experiments show very accurate calibration and navigation results.

  6. A hybrid model to predict the onset of gas entrainment with surface tension effects

    International Nuclear Information System (INIS)

    Saleh, W.; Bowden, R.C.; Hassan, I.G.; Kadem, L.

    2008-01-01

    The onset of gas entrainment, in a single downward oriented discharge from a stratified gas-liquid region with was modeled. The assumptions made in the development of the model reduced the problem to that of a potential flow. The discharge was modeled as a point-sink. Through use of the Kelvin-Laplace equation the model included the effects of surface tension. The resulting model required further knowledge of the flow field, specifically the dip radius of curvature prior to the onset of gas entrainment. The dip shape and size was investigated experimentally and correlations were provided to characterize the dip in terms of the discharge Froude number. The experimental correlation was used in conjunction with the theoretical model to predict the critical height. The results showed that by including surface tension effects the predicted critical height showed excellent agreement with experimental data. Surface tension reduces the critical height through the Bond number

  7. Adaptive Hybrid Control of Vehicle Semiactive Suspension Based on Road Profile Estimation

    Directory of Open Access Journals (Sweden)

    Yechen Qin

    2015-01-01

    Full Text Available A new road estimation based suspension hybrid control strategy is proposed. Its aim is to adaptively change control gains to improve both ride comfort and road handling with the constraint of rattle space. To achieve this, analytical expressions for ride comfort, road handling, and rattle space with respect to road input are derived based on the hybrid control, and the problem is transformed into a MOOP (Multiobjective Optimization Problem and has been solved by NSGA-II (Nondominated Sorting Genetic Algorithm-II. A new road estimation and classification method, which is based on ANFIS (Adaptive Neurofuzzy Inference System and wavelet transforms, is then presented as a means of detecting the road profile level, and a Kalman filter is designed for observing unknown states. The results of simulations conducted with random road excitation show that the efficiency of the proposed control strategy compares favourably to that of a passive system.

  8. Tension layer winding of cable-in-conduit conductor

    International Nuclear Information System (INIS)

    Devernoe, A.; Ciancetta, G.; King, M.; Parizh, M.; Painter, T.; Miller, J.

    1996-01-01

    A 710 mm i.d. by 440 mm long, 6 layer Cable-in-Conduit (CIC) coil was precision tension layer wound with Incoloy 908 jacketed conductor to model winding technology that will be used for the Nb 3 Sn outsert coils of the 45 Tesla Hybrid Magnet Project at the US National High Magnetic Field Laboratory. This paper reports on the set up of a new winding facility with unique capabilities for insulating and winding long length CIC conductor and on special procedures which were developed to wind and support layer to layer transitions and to safely form conductor into and out of the winding. Analytical methods used to predict conduit keystoning, springback and back tensioning requirements before winding are reported in comparison to results obtained during winding and actual winding build-up dimensions on a layer by layer basis in comparison to design requirements

  9. Effect of potential attraction term on surface tension of ionic liquids

    Science.gov (United States)

    Vaziri, N.; Khordad, R.; Rezaei, G.

    2018-03-01

    In this work, we have studied the effect of attraction term of molecular potential on surface tension of ionic liquids (ILs). For this purpose, we have introduced two different potential models to obtain analytical expressions for the surface tension of ILs. The introduced potential models have different attraction terms. The obtained surface tensions in this work have been compared with other theoretical methods and also experimental data. Using the calculated surface tension, the sound velocity is also estimated. We have studied the structural effects on the surface tensions of imidazolium-based ionic liquids. It is found that the cation alkyl chain length and the anion size play important roles to the surface tension of the selected ionic liquids. The calculated surface tensions show a good harmony with experimental data. It is clear that the attraction term of molecular potential has an important role on surface tension and sound velocity of our system.

  10. Tension Headache

    Science.gov (United States)

    ... tight band around your head. A tension headache (tension-type headache) is the most common type of headache, and ... Headache after a head injury, especially if the headache gets worse ... tension or stress. But research suggests muscle contraction isn't the ...

  11. Effect of elevated temperature on the tensile strength of Napier/glass-epoxy hybrid reinforced composites

    Science.gov (United States)

    Ridzuan, M. J. M.; Majid, M. S. Abdul; Afendi, M.; Firdaus, A. Z. Ahmad; Azduwin, K.

    2017-11-01

    The effects of elevated temperature on the tensile strength of Napier/glass-epoxy hybrid reinforced composites and its morphology of fractured surfaces are discussed. Napier/glass-epoxy hybrid reinforced composites were fabricated by using vacuum infusion method by arranging Napier fibres in between sheets of woven glass fibres. Napier and glass fibres were laminated with estimated volume ratios were 24 and 6 vol. %, respectively. The epoxy resin was used as matrix estimated to 70 vol. %. Specimens were tested to failure under tension at a cross-head speed of 1 mm/min using Universal Testing Machine (Instron) with a load cell 100 kN at four different temperatures of RT, 40°C, 60°C and 80°C. The morphology of fractured surface of hybrid composites was investigated by field emission scanning electron microscopy. The result shows reduction in tensile strength at elevated temperatures. The increase in the temperature activates the process of diffusion, and generates critical stresses which cause the damage at first-ply or at the centre of the hybrid plate, as a result lower the tensile strength. The observation of FESEM images indicates that the fracture mode is of evolution of localized damage, from fibre/matrix debonding, matric cracking, delamination and fibre breakage.

  12. Fatigue of hybrid glass/carbon composites: 3D computational studies

    DEFF Research Database (Denmark)

    Dai, Gaoming; Mishnaevsky, Leon

    2014-01-01

    3D computational simulations of fatigue of hybrid carbon/glass fiber reinforced composites is carried out using X-FEM and multifiber unit cell models. A new software code for the automatic generation of unit cell multifiber models of composites with randomly misaligned fibers of various properties...... and geometrical parameters is developed. With the use of this program code and the X-FEM method, systematic investigations of the effect of microstructure of hybrid composites (fraction of carbon versus glass fibers, misalignment, and interface strength) and the loading conditions (tensile versus compression...... cyclic loading effects) on fatigue behavior of the materials are carried out. It was demonstrated that the higher fraction of carbon fibers in hybrid composites is beneficial for the fatigue lifetime of the composites under tension-tension cyclic loading, but might have negative effect on the lifetime...

  13. A Hybrid Estimator for Active/Reactive Power Control of Single-Phase Distributed Generation Systems with Energy Storage

    DEFF Research Database (Denmark)

    Pahlevani, Majid; Eren, Suzan; Guerrero, Josep M.

    2016-01-01

    This paper presents a new active/reactive power closed-loop control system for a hybrid renewable energy generation system used for single-phase residential/commercial applications. The proposed active/reactive control method includes a hybrid estimator, which is able to quickly and accurately es...

  14. Axisymmetric Drop Shape Analysis for Estimating the Surface Tension of Cell Aggregates by Centrifugation

    OpenAIRE

    Kalantarian, Ali; Ninomiya, Hiromasa; Saad, Sameh M.I.; David, Robert; Winklbauer, Rudolf; Neumann, A. Wilhelm

    2009-01-01

    Biological tissues behave in certain respects like liquids. Consequently, the surface tension concept can be used to explain aspects of the in vitro and in vivo behavior of multicellular aggregates. Unfortunately, conventional methods of surface tension measurement cannot be readily applied to small cell aggregates. This difficulty can be overcome by an experimentally straightforward method consisting of centrifugation followed by axisymmetric drop shape analysis (ADSA). Since the aggregates ...

  15. A hybrid system approach to airspeed, angle of attack and sideslip estimation in Unmanned Aerial Vehicles

    KAUST Repository

    Shaqura, Mohammad; Claudel, Christian

    2015-01-01

    , low power autopilots in real-time. The computational method is based on a hybrid decomposition of the modes of operation of the UAV. A Bayesian approach is considered for estimation, in which the estimated airspeed, angle of attack and sideslip

  16. Automated wireless monitoring system for cable tension using smart sensors

    Science.gov (United States)

    Sim, Sung-Han; Li, Jian; Jo, Hongki; Park, Jongwoong; Cho, Soojin; Spencer, Billie F.; Yun, Chung-Bang

    2013-04-01

    Cables are critical load carrying members of cable-stayed bridges; monitoring tension forces of the cables provides valuable information for SHM of the cable-stayed bridges. Monitoring systems for the cable tension can be efficiently realized using wireless smart sensors in conjunction with vibration-based cable tension estimation approaches. This study develops an automated cable tension monitoring system using MEMSIC's Imote2 smart sensors. An embedded data processing strategy is implemented on the Imote2-based wireless sensor network to calculate cable tensions using a vibration-based method, significantly reducing the wireless data transmission and associated power consumption. The autonomous operation of the monitoring system is achieved by AutoMonitor, a high-level coordinator application provided by the Illinois SHM Project Services Toolsuite. The monitoring system also features power harvesting enabled by solar panels attached to each sensor node and AutoMonitor for charging control. The proposed wireless system has been deployed on the Jindo Bridge, a cable-stayed bridge located in South Korea. Tension forces are autonomously monitored for 12 cables in the east, land side of the bridge, proving the validity and potential of the presented tension monitoring system for real-world applications.

  17. Prediction of surface tension of binary mixtures with the parachor method

    Directory of Open Access Journals (Sweden)

    Němec Tomáš

    2015-01-01

    Full Text Available The parachor method for the estimation of the surface tension of binary mixtures is modified by considering temperature-dependent values of the parachor parameters. The temperature dependence is calculated by a least-squares fit of pure-solvent surface tension data to the binary parachor equation utilizing the Peng-Robinson equation of state for the calculation of equilibrium densities. A very good agreement between experimental binary surface tension data and the predictions of the modified parachor method are found for the case of the mixtures of carbon dioxide and butane, benzene, and cyclohexane, respectively. The surface tension is also predicted for three refrigerant mixtures, i.e. propane, isobutane, and chlorodifluoromethane, with carbon dioxide.

  18. Bayesian estimation of realized stochastic volatility model by Hybrid Monte Carlo algorithm

    International Nuclear Information System (INIS)

    Takaishi, Tetsuya

    2014-01-01

    The hybrid Monte Carlo algorithm (HMCA) is applied for Bayesian parameter estimation of the realized stochastic volatility (RSV) model. Using the 2nd order minimum norm integrator (2MNI) for the molecular dynamics (MD) simulation in the HMCA, we find that the 2MNI is more efficient than the conventional leapfrog integrator. We also find that the autocorrelation time of the volatility variables sampled by the HMCA is very short. Thus it is concluded that the HMCA with the 2MNI is an efficient algorithm for parameter estimations of the RSV model

  19. Advanced RESTART method for the estimation of the probability of failure of highly reliable hybrid dynamic systems

    International Nuclear Information System (INIS)

    Turati, Pietro; Pedroni, Nicola; Zio, Enrico

    2016-01-01

    The efficient estimation of system reliability characteristics is of paramount importance for many engineering applications. Real world system reliability modeling calls for the capability of treating systems that are: i) dynamic, ii) complex, iii) hybrid and iv) highly reliable. Advanced Monte Carlo (MC) methods offer a way to solve these types of problems, which are feasible according to the potentially high computational costs. In this paper, the REpetitive Simulation Trials After Reaching Thresholds (RESTART) method is employed, extending it to hybrid systems for the first time (to the authors’ knowledge). The estimation accuracy and precision of RESTART highly depend on the choice of the Importance Function (IF) indicating how close the system is to failure: in this respect, proper IFs are here originally proposed to improve the performance of RESTART for the analysis of hybrid systems. The resulting overall simulation approach is applied to estimate the probability of failure of the control system of a liquid hold-up tank and of a pump-valve subsystem subject to degradation induced by fatigue. The results are compared to those obtained by standard MC simulation and by RESTART with classical IFs available in the literature. The comparison shows the improvement in the performance obtained by our approach. - Highlights: • We consider the issue of estimating small failure probabilities in dynamic systems. • We employ the RESTART method to estimate the failure probabilities. • New Importance Functions (IFs) are introduced to increase the method performance. • We adopt two dynamic, hybrid, highly reliable systems as case studies. • A comparison with literature IFs proves the effectiveness of the new IFs.

  20. Coulomb string tension, asymptotic string tension, and the gluon chain

    OpenAIRE

    Greensite, Jeff; Szczepaniak, Adam P.

    2014-01-01

    We compute, via numerical simulations, the non-perturbative Coulomb potential of pure SU(3) gauge theory in Coulomb gauge. We find that that the Coulomb potential scales nicely in accordance with asymptotic freedom, that the Coulomb potential is linear in the infrared, and that the Coulomb string tension is about four times larger than the asymptotic string tension. We explain how it is possible that the asymptotic string tension can be lower than the Coulomb string tension by a factor of four.

  1. Clutch pressure estimation for a power-split hybrid transmission using nonlinear robust observer

    Science.gov (United States)

    Zhou, Bin; Zhang, Jianwu; Gao, Ji; Yu, Haisheng; Liu, Dong

    2018-06-01

    For a power-split hybrid transmission, using the brake clutch to realize the transition from electric drive mode to hybrid drive mode is an available strategy. Since the pressure information of the brake clutch is essential for the mode transition control, this research designs a nonlinear robust reduced-order observer to estimate the brake clutch pressure. Model uncertainties or disturbances are considered as additional inputs, thus the observer is designed in order that the error dynamics is input-to-state stable. The nonlinear characteristics of the system are expressed as the lookup tables in the observer. Moreover, the gain matrix of the observer is solved by two optimization procedures under the constraints of the linear matrix inequalities. The proposed observer is validated by offline simulation and online test, the results have shown that the observer achieves significant performance during the mode transition, as the estimation error is within a reasonable range, more importantly, it is asymptotically stable.

  2. Mapping surface tension induced menisci with application to tensiometry and refractometry.

    Science.gov (United States)

    Mishra, Avanish; Kulkarni, Varun; Khor, Jian-Wei; Wereley, Steve

    2015-07-28

    In this work, we discuss an optical method for measuring surface tension induced menisci. The principle of measurement is based upon the change in the background pattern produced by the curvature of the meniscus acting as a lens. We measure the meniscus profile over an inclined glass plate and utilize the measured meniscus for estimation of surface tension and refractive index.

  3. Semi-empirical modelling for forest above ground biomass estimation using hybrid and fully PolSAR data

    Science.gov (United States)

    Tomar, Kiledar S.; Kumar, Shashi; Tolpekin, Valentyn A.; Joshi, Sushil K.

    2016-05-01

    Forests act as sink of carbon and as a result maintains carbon cycle in atmosphere. Deforestation leads to imbalance in global carbon cycle and changes in climate. Hence estimation of forest biophysical parameter like biomass becomes a necessity. PolSAR has the ability to discriminate the share of scattering element like surface, double bounce and volume scattering in a single SAR resolution cell. Studies have shown that volume scattering is a significant parameter for forest biophysical characterization which mainly occurred from vegetation due to randomly oriented structures. This random orientation of forest structure causes shift in orientation angle of polarization ellipse which ultimately disturbs the radar signature and shows overestimation of volume scattering and underestimation of double bounce scattering after decomposition of fully PolSAR data. Hybrid polarimetry has the advantage of zero POA shift due to rotational symmetry followed by the circular transmission of electromagnetic waves. The prime objective of this study was to extract the potential of Hybrid PolSAR and fully PolSAR data for AGB estimation using Extended Water Cloud model. Validation was performed using field biomass. The study site chosen was Barkot Forest, Uttarakhand, India. To obtain the decomposition components, m-alpha and Yamaguchi decomposition modelling for Hybrid and fully PolSAR data were implied respectively. The RGB composite image for both the decomposition techniques has generated. The contribution of all scattering from each plot for m-alpha and Yamaguchi decomposition modelling were extracted. The R2 value for modelled AGB and field biomass from Hybrid PolSAR and fully PolSAR data were found 0.5127 and 0.4625 respectively. The RMSE for Hybrid and fully PolSAR between modelled AGB and field biomass were 63.156 (t ha-1) and 73.424 (t ha-1) respectively. On the basis of RMSE and R2 value, this study suggests Hybrid PolSAR decomposition modelling to retrieve scattering

  4. Construction cost estimation of spherical storage tanks: artificial neural networks and hybrid regression—GA algorithms

    Science.gov (United States)

    Arabzadeh, Vida; Niaki, S. T. A.; Arabzadeh, Vahid

    2017-10-01

    One of the most important processes in the early stages of construction projects is to estimate the cost involved. This process involves a wide range of uncertainties, which make it a challenging task. Because of unknown issues, using the experience of the experts or looking for similar cases are the conventional methods to deal with cost estimation. The current study presents data-driven methods for cost estimation based on the application of artificial neural network (ANN) and regression models. The learning algorithms of the ANN are the Levenberg-Marquardt and the Bayesian regulated. Moreover, regression models are hybridized with a genetic algorithm to obtain better estimates of the coefficients. The methods are applied in a real case, where the input parameters of the models are assigned based on the key issues involved in a spherical tank construction. The results reveal that while a high correlation between the estimated cost and the real cost exists; both ANNs could perform better than the hybridized regression models. In addition, the ANN with the Levenberg-Marquardt learning algorithm (LMNN) obtains a better estimation than the ANN with the Bayesian-regulated learning algorithm (BRNN). The correlation between real data and estimated values is over 90%, while the mean square error is achieved around 0.4. The proposed LMNN model can be effective to reduce uncertainty and complexity in the early stages of the construction project.

  5. Performance estimation of photovoltaic–thermoelectric hybrid systems

    International Nuclear Information System (INIS)

    Zhang, Jin; Xuan, Yimin; Yang, Lili

    2014-01-01

    A theoretical model for evaluating the efficiency of concentrating PV–TE (photovoltaic–thermoelectric) hybrid system is developed in this paper. Hybrid systems with different photovoltaic cells are studied, including crystalline silicon photovoltaic cell, silicon thin-film photovoltaic cell, polymer photovoltaic cell and copper indium gallium selenide photovoltaic cell. The influence of temperature on the efficiency of photovoltaic cell has been taken into account based on the semiconductor equations, which reveals different efficiency temperature characteristic of polymer photovoltaic cells. It is demonstrated that the polycrystalline silicon thin-film photovoltaic cell is suitable for concentrating PV–TE hybrid system through optimization of the convection heat transfer coefficient and concentrating ratio. The polymer photovoltaic cell is proved to be suitable for non-concentrating PV–TE hybrid system. - Highlights: • Performances of four types of photovoltaic–thermoelectric hybrid systems are studied. • Temperature is one of dominant factors of affecting the conversion efficiency of PV–TE systems. • One can select a proper PV–TE assembly system according to given operating conditions

  6. Estimation of polyclonal IgG4 hybrids in normal human serum.

    Science.gov (United States)

    Young, Elizabeth; Lock, Emma; Ward, Douglas G; Cook, Alexander; Harding, Stephen; Wallis, Gregg L F

    2014-07-01

    The in vivo or in vitro formation of IgG4 hybrid molecules, wherein the immunoglobulins have exchanged half molecules, has previously been reported under experimental conditions. Here we estimate the incidence of polyclonal IgG4 hybrids in normal human serum and comment on the existence of IgG4 molecules with different immunoglobulin light chains. Polyclonal IgG4 was purified from pooled or individual donor human sera and sequentially fractionated using light-chain affinity and size exclusion chromatography. Fractions were analysed by SDS-PAGE, immunoblotting, ELISA, immunodiffusion and matrix-assisted laser-desorption mass spectrometry. Polyclonal IgG4 purified from normal serum contained IgG4κ, IgG4λ and IgG4κ/λ molecules. Size exclusion chromatography showed that IgG4 was principally present in monomeric form (150 000 MW). SDS-PAGE, immunoblotting and ELISA showed the purity of the three IgG4 samples. Immunodiffusion, light-chain sandwich ELISA and mass spectrometry demonstrated that both κ and λ light chains were present on only the IgG4κ/λ molecules. The amounts of IgG4κ/λ hybrid molecules ranged from 21 to 33% from the five sera analysed. Based on the molecular weight these molecules were formed of two IgG4 heavy chains plus one κ and one λ light chain. Polyclonal IgG (IgG4-depleted) was similarly fractionated according to light-chain specificity. No evidence of hybrid IgG κ/λ antibodies was observed. These results indicate that hybrid IgG4κ/λ antibodies compose a substantial portion of IgG4 from normal human serum. © 2014 John Wiley & Sons Ltd.

  7. Necessary Tension in Marine Risers Tension des colonnes montantes en mer

    Directory of Open Access Journals (Sweden)

    Lubinski A.

    2006-11-01

    Full Text Available The tension governing transverse static and dynamic deflections in a riser is not the actual tension but the so-called « effective tension » The concept of effective tension and effective compression is thoroughly explained, and means for calculating effective forces are given. Numerical examples are worked out for risers whose length is between 152 m (520 ft and 920 m (3020 ft. The reciprocal of maximum bending moment of the vicinity of the hall joint is plotted versus the effective tension of the ball joint. Bending moments used were obtained through use of static and dynamic computer programs applied ta a variety of conditions of wave loading, use or non-use of buoyant moterial sleeves, etc. The most important parameters affecting riser performance are the effective La tension régissant les déflections transversales statiques et dynamiques d'une colonne montante n'est pas la tension réelle mais ce qu'on appelle « la tension effective ». Le concept de tension ou de compression effective est expliqué en détail et la façon de calculer les forces effectives est indiquée dans cet article. Des exemples numériques sont développés pour des colonnes montantes de longueur comprise entre 152 m (520 ft et 920 m (3 020 ft. On a tracé la courbe de l'inverse du moment fléchissant en fonction de la tension effective à l'articulation. Les moments fléchissants utilisés ont été calculés par ordinateur en utilisant des programmes dynamiques et statiques pour des conditions variées d'action des vagues, la colonne montante étant ou non munie de manchettes de flottabilité, etc. Les deux paramètres les plus importants qui affectent le bon comportement d'une colonne montante sont la tension effective et la charge latérale.

  8. Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities

    Science.gov (United States)

    Baylin-Stern, Adam C.

    This paper demonstrates how an U.S. application of CIMS, a technologically explicit and behaviourally realistic energy-economy simulation model which includes macro-economic feedbacks, can be used to derive estimates of elasticity of substitution (ESUB) and autonomous energy efficiency index (AEEI) parameters. The ability of economies to reduce greenhouse gas emissions depends on the potential for households and industry to decrease overall energy usage, and move from higher to lower emissions fuels. Energy economists commonly refer to ESUB estimates to understand the degree of responsiveness of various sectors of an economy, and use estimates to inform computable general equilibrium models used to study climate policies. Using CIMS, I have generated a set of future, 'pseudo-data' based on a series of simulations in which I vary energy and capital input prices over a wide range. I then used this data set to estimate the parameters for transcendental logarithmic production functions using regression techniques. From the production function parameter estimates, I calculated an array of elasticity of substitution values between input pairs. Additionally, this paper demonstrates how CIMS can be used to calculate price-independent changes in energy-efficiency in the form of the AEEI, by comparing energy consumption between technologically frozen and 'business as usual' simulations. The paper concludes with some ideas for model and methodological improvement, and how these might figure into future work in the estimation of ESUBs from CIMS. Keywords: Elasticity of substitution; hybrid energy-economy model; translog; autonomous energy efficiency index; rebound effect; fuel switching.

  9. Estimation of volt second saving by application of lower hybrid waves on JET

    International Nuclear Information System (INIS)

    Van Houtte, D.

    1987-12-01

    Volt-second saving by application of lower hybrid current discharges on JET is assessed and the extent of the duration time of the flat top current is estimated. A data base obtained mainly on PETULA is compared with theory. Together with an optimization of LH and plasma parameters, a hybrid (OH-LH) current drive operating scenario for volt-second saving is proposed for JET. An RF-assisted ohmic heating current rises up on JET enables volt-second to be saved enough to achieve a longer plasma current flat top than could be achieved by ohmic heating alone. This plasma current, up to I p = 7MA, should last as long as the toroidal and equilibrium field allows it

  10. Temperature dependent power capability estimation of lithium-ion batteries for hybrid electric vehicles

    International Nuclear Information System (INIS)

    Zheng, Fangdan; Jiang, Jiuchun; Sun, Bingxiang; Zhang, Weige; Pecht, Michael

    2016-01-01

    The power capability of lithium-ion batteries affects the safety and reliability of hybrid electric vehicles and the estimate of power by battery management systems provides operating information for drivers. In this paper, lithium ion manganese oxide batteries are studied to illustrate the temperature dependency of power capability and an operating map of power capability is presented. Both parametric and non-parametric models are established in conditions of temperature, state of charge, and cell resistance to estimate the power capability. Six cells were tested and used for model development, training, and validation. Three samples underwent hybrid pulse power characterization tests at varied temperatures and were used for model parameter identification and model training. The other three were used for model validation. By comparison, the mean absolute error of the parametric model is about 29 W, and that of the non-parametric model is around 20 W. The mean relative errors of two models are 0.076 and 0.397, respectively. The parametric model has a higher accuracy in low temperature and state of charge conditions, while the non-parametric model has better estimation result in high temperature and state of charge conditions. Thus, two models can be utilized together to achieve a higher accuracy of power capability estimation. - Highlights: • The temperature dependency of power capability of lithium-ion battery is investigated. • The parametric and non-parametric power capability estimation models are proposed. • An exponential function is put forward to compensate the effects of temperature. • A comparative study on the accuracy of two models using statistical metrics is presented.

  11. Investigating the molecular underpinnings underlying morphology and changes in carbon partitioning during tension wood formation in Eucalyptus.

    Science.gov (United States)

    Mizrachi, Eshchar; Maloney, Victoria J; Silberbauer, Janine; Hefer, Charles A; Berger, Dave K; Mansfield, Shawn D; Myburg, Alexander A

    2015-06-01

    Tension wood has distinct physical and chemical properties, including altered fibre properties, cell wall composition and ultrastructure. It serves as a good system for investigating the genetic regulation of secondary cell wall biosynthesis and wood formation. The reference genome sequence for Eucalyptus grandis allows investigation of the global transcriptional reprogramming that accompanies tension wood formation in this global wood fibre crop. We report the first comprehensive analysis of physicochemical wood property changes in tension wood of Eucalyptus measured in a hybrid (E. grandis × Eucalyptus urophylla) clone, as well as genome-wide gene expression changes in xylem tissues 3 wk post-induction using RNA sequencing. We found that Eucalyptus tension wood in field-grown trees is characterized by an increase in cellulose, a reduction in lignin, xylose and mannose, and a marked increase in galactose. Gene expression profiling in tension wood-forming tissue showed corresponding down-regulation of monolignol biosynthetic genes, and differential expression of several carbohydrate active enzymes. We conclude that alterations of cell wall traits induced by tension wood formation in Eucalyptus are a consequence of a combination of down-regulation of lignin biosynthesis and hemicellulose remodelling, rather than the often proposed up-regulation of the cellulose biosynthetic pathway. © 2014 University of Pretoria New Phytologist © 2014 New Phytologist Trust.

  12. Mesospheric gravity wave momentum flux estimation using hybrid Doppler interferometry

    Directory of Open Access Journals (Sweden)

    A. J. Spargo

    2017-06-01

    Full Text Available Mesospheric gravity wave (GW momentum flux estimates using data from multibeam Buckland Park MF radar (34.6° S, 138.5° E experiments (conducted from July 1997 to June 1998 are presented. On transmission, five Doppler beams were symmetrically steered about the zenith (one zenith beam and four off-zenith beams in the cardinal directions. The received beams were analysed with hybrid Doppler interferometry (HDI (Holdsworth and Reid, 1998, principally to determine the radial velocities of the effective scattering centres illuminated by the radar. The methodology of Thorsen et al. (1997, later re-introduced by Hocking (2005 and since extensively applied to meteor radar returns, was used to estimate components of Reynolds stress due to propagating GWs and/or turbulence in the radar resolution volume. Physically reasonable momentum flux estimates are derived from the Reynolds stress components, which are also verified using a simple radar model incorporating GW-induced wind perturbations. On the basis of these results, we recommend the intercomparison of momentum flux estimates between co-located meteor radars and vertical-beam interferometric MF radars. It is envisaged that such intercomparisons will assist with the clarification of recent concerns (e.g. Vincent et al., 2010 of the accuracy of the meteor radar technique.

  13. Mesospheric gravity wave momentum flux estimation using hybrid Doppler interferometry

    Science.gov (United States)

    Spargo, Andrew J.; Reid, Iain M.; MacKinnon, Andrew D.; Holdsworth, David A.

    2017-06-01

    Mesospheric gravity wave (GW) momentum flux estimates using data from multibeam Buckland Park MF radar (34.6° S, 138.5° E) experiments (conducted from July 1997 to June 1998) are presented. On transmission, five Doppler beams were symmetrically steered about the zenith (one zenith beam and four off-zenith beams in the cardinal directions). The received beams were analysed with hybrid Doppler interferometry (HDI) (Holdsworth and Reid, 1998), principally to determine the radial velocities of the effective scattering centres illuminated by the radar. The methodology of Thorsen et al. (1997), later re-introduced by Hocking (2005) and since extensively applied to meteor radar returns, was used to estimate components of Reynolds stress due to propagating GWs and/or turbulence in the radar resolution volume. Physically reasonable momentum flux estimates are derived from the Reynolds stress components, which are also verified using a simple radar model incorporating GW-induced wind perturbations. On the basis of these results, we recommend the intercomparison of momentum flux estimates between co-located meteor radars and vertical-beam interferometric MF radars. It is envisaged that such intercomparisons will assist with the clarification of recent concerns (e.g. Vincent et al., 2010) of the accuracy of the meteor radar technique.

  14. Hybrid fuzzy charged system search algorithm based state estimation in distribution networks

    Directory of Open Access Journals (Sweden)

    Sachidananda Prasad

    2017-06-01

    Full Text Available This paper proposes a new hybrid charged system search (CSS algorithm based state estimation in radial distribution networks in fuzzy framework. The objective of the optimization problem is to minimize the weighted square of the difference between the measured and the estimated quantity. The proposed method of state estimation considers bus voltage magnitude and phase angle as state variable along with some equality and inequality constraints for state estimation in distribution networks. A rule based fuzzy inference system has been designed to control the parameters of the CSS algorithm to achieve better balance between the exploration and exploitation capability of the algorithm. The efficiency of the proposed fuzzy adaptive charged system search (FACSS algorithm has been tested on standard IEEE 33-bus system and Indian 85-bus practical radial distribution system. The obtained results have been compared with the conventional CSS algorithm, weighted least square (WLS algorithm and particle swarm optimization (PSO for feasibility of the algorithm.

  15. A hybrid computational approach to estimate solar global radiation: An empirical evidence from Iran

    International Nuclear Information System (INIS)

    Mostafavi, Elham Sadat; Ramiyani, Sara Saeidi; Sarvar, Rahim; Moud, Hashem Izadi; Mousavi, Seyyed Mohammad

    2013-01-01

    This paper presents an innovative hybrid approach for the estimation of the solar global radiation. New prediction equations were developed for the global radiation using an integrated search method of genetic programming (GP) and simulated annealing (SA), called GP/SA. The solar radiation was formulated in terms of several climatological and meteorological parameters. Comprehensive databases containing monthly data collected for 6 years in two cities of Iran were used to develop GP/SA-based models. Separate models were established for each city. The generalization of the models was verified using a separate testing database. A sensitivity analysis was conducted to investigate the contribution of the parameters affecting the solar radiation. The derived models make accurate predictions of the solar global radiation and notably outperform the existing models. -- Highlights: ► A hybrid approach is presented for the estimation of the solar global radiation. ► The proposed method integrates the capabilities of GP and SA. ► Several climatological and meteorological parameters are included in the analysis. ► The GP/SA models make accurate predictions of the solar global radiation.

  16. Hybrid system of unbonded post-tensioned CLT panels and light-frame wood shear walls

    Science.gov (United States)

    T. Ho; T. Dao; S. Aaleti; J. van de Lindt; Douglas Rammer

    2016-01-01

    Cross-laminated timber (CLT) is a relatively new type of massive timber system that has shown to possess excellent mechanical properties and structural behavior in building construction. When post-tensioned with high-strength tendons, CLT panels perform well under cyclic loadings because of two key characteristics: their rocking behavior and self-centering capacity....

  17. An adaptive hybrid EnKF-OI scheme for efficient state-parameter estimation of reactive contaminant transport models

    KAUST Repository

    El Gharamti, Mohamad; Valstar, Johan R.; Hoteit, Ibrahim

    2014-01-01

    Reactive contaminant transport models are used by hydrologists to simulate and study the migration and fate of industrial waste in subsurface aquifers. Accurate transport modeling of such waste requires clear understanding of the system's parameters, such as sorption and biodegradation. In this study, we present an efficient sequential data assimilation scheme that computes accurate estimates of aquifer contamination and spatially variable sorption coefficients. This assimilation scheme is based on a hybrid formulation of the ensemble Kalman filter (EnKF) and optimal interpolation (OI) in which solute concentration measurements are assimilated via a recursive dual estimation of sorption coefficients and contaminant state variables. This hybrid EnKF-OI scheme is used to mitigate background covariance limitations due to ensemble under-sampling and neglected model errors. Numerical experiments are conducted with a two-dimensional synthetic aquifer in which cobalt-60, a radioactive contaminant, is leached in a saturated heterogeneous clayey sandstone zone. Assimilation experiments are investigated under different settings and sources of model and observational errors. Simulation results demonstrate that the proposed hybrid EnKF-OI scheme successfully recovers both the contaminant and the sorption rate and reduces their uncertainties. Sensitivity analyses also suggest that the adaptive hybrid scheme remains effective with small ensembles, allowing to reduce the ensemble size by up to 80% with respect to the standard EnKF scheme. © 2014 Elsevier Ltd.

  18. An adaptive hybrid EnKF-OI scheme for efficient state-parameter estimation of reactive contaminant transport models

    KAUST Repository

    El Gharamti, Mohamad

    2014-09-01

    Reactive contaminant transport models are used by hydrologists to simulate and study the migration and fate of industrial waste in subsurface aquifers. Accurate transport modeling of such waste requires clear understanding of the system\\'s parameters, such as sorption and biodegradation. In this study, we present an efficient sequential data assimilation scheme that computes accurate estimates of aquifer contamination and spatially variable sorption coefficients. This assimilation scheme is based on a hybrid formulation of the ensemble Kalman filter (EnKF) and optimal interpolation (OI) in which solute concentration measurements are assimilated via a recursive dual estimation of sorption coefficients and contaminant state variables. This hybrid EnKF-OI scheme is used to mitigate background covariance limitations due to ensemble under-sampling and neglected model errors. Numerical experiments are conducted with a two-dimensional synthetic aquifer in which cobalt-60, a radioactive contaminant, is leached in a saturated heterogeneous clayey sandstone zone. Assimilation experiments are investigated under different settings and sources of model and observational errors. Simulation results demonstrate that the proposed hybrid EnKF-OI scheme successfully recovers both the contaminant and the sorption rate and reduces their uncertainties. Sensitivity analyses also suggest that the adaptive hybrid scheme remains effective with small ensembles, allowing to reduce the ensemble size by up to 80% with respect to the standard EnKF scheme. © 2014 Elsevier Ltd.

  19. Constraining brane tension using rotation curves of galaxies

    Science.gov (United States)

    García-Aspeitia, Miguel A.; Rodríguez-Meza, Mario A.

    2018-04-01

    We present in this work a study of brane theory phenomenology focusing on the brane tension parameter, which is the main observable of the theory. We show the modifications steaming from the presence of branes in the rotation curves of spiral galaxies for three well known dark matter density profiles: Pseudo isothermal, Navarro-Frenk-White and Burkert dark matter density profiles. We estimate the brane tension parameter using a sample of high resolution observed rotation curves of low surface brightness spiral galaxies and a synthetic rotation curve for the three density profiles. Also, the fittings using the brane theory model of the rotation curves are compared with standard Newtonian models. We found that Navarro-Frenk-White model prefers lower values of the brane tension parameter, on the average λ ∼ 0.73 × 10‑3eV4, therefore showing clear brane effects. Burkert case does prefer higher values of the tension parameter, on the average λ ∼ 0.93 eV4 ‑ 46 eV4, i.e., negligible brane effects. Whereas pseudo isothermal is an intermediate case. Due to the low densities found in the galactic medium it is almost impossible to find evidence of the presence of extra dimensions. In this context, we found that our results show weaker bounds to the brane tension values in comparison with other bounds found previously, as the lower value found for dwarf stars composed of a polytropic equation of state, λ ≈ 104 MeV4.

  20. Gravity Search Algorithm hybridized Recursive Least Square method for power system harmonic estimation

    Directory of Open Access Journals (Sweden)

    Santosh Kumar Singh

    2017-06-01

    Full Text Available This paper presents a new hybrid method based on Gravity Search Algorithm (GSA and Recursive Least Square (RLS, known as GSA-RLS, to solve the harmonic estimation problems in the case of time varying power signals in presence of different noises. GSA is based on the Newton’s law of gravity and mass interactions. In the proposed method, the searcher agents are a collection of masses that interact with each other using Newton’s laws of gravity and motion. The basic GSA algorithm strategy is combined with RLS algorithm sequentially in an adaptive way to update the unknown parameters (weights of the harmonic signal. Simulation and practical validation are made with the experimentation of the proposed algorithm with real time data obtained from a heavy paper industry. A comparative performance of the proposed algorithm is evaluated with other recently reported algorithms like, Differential Evolution (DE, Particle Swarm Optimization (PSO, Bacteria Foraging Optimization (BFO, Fuzzy-BFO (F-BFO hybridized with Least Square (LS and BFO hybridized with RLS algorithm, which reveals that the proposed GSA-RLS algorithm is the best in terms of accuracy, convergence and computational time.

  1. The environmental factors as reason for emotional tension

    Science.gov (United States)

    Prisniakova, L.

    The information from environment is a reason of activation of an organism, it calls abrupt changings in nervous processes and it offers emotions. One part of emotions organizes and supports activity, others disorganize it. In fields of perception, of making decision, fulfilment of operatings, of learning the emotional excitation raises the level of carrying-out more easy problems and reduces of more difficult one. The report are presented the outcomes of quantitative determination of a level of emotional tension on successful activity. The inverse of the sign of influencing on efficiency of activity of the man is detected. The action of the emotional tension on efficiency of professional work was demonstrated to have similarly to influencing of motivation according to the law Yerkes -Dodson. The report introduces a mathematical model of connection of successful activity and motivations or the emotional tension. Introduced in the report the outcomes can serve the theoretical idealized basis of the quantitative characteristics of an estimation of activity of astronauts in conditions of the emotional factors at a phase of selection

  2. A density gradient theory based method for surface tension calculations

    DEFF Research Database (Denmark)

    Liang, Xiaodong; Michelsen, Michael Locht; Kontogeorgis, Georgios

    2016-01-01

    The density gradient theory has been becoming a widely used framework for calculating surface tension, within which the same equation of state is used for the interface and bulk phases, because it is a theoretically sound, consistent and computationally affordable approach. Based on the observation...... that the optimal density path from the geometric mean density gradient theory passes the saddle point of the tangent plane distance to the bulk phases, we propose to estimate surface tension with an approximate density path profile that goes through this saddle point. The linear density gradient theory, which...... assumes linearly distributed densities between the two bulk phases, has also been investigated. Numerical problems do not occur with these density path profiles. These two approximation methods together with the full density gradient theory have been used to calculate the surface tension of various...

  3. Reactor vessel stud tensioner

    International Nuclear Information System (INIS)

    Malandra, L.J.; Beer, R.W.; Salton, R.B.; Spiegelman, S.R.; Cognevich, M.L.

    1982-01-01

    A quick-acting stud tensioner, for facilitating the loosening or tightening of a stud nut on a reactor vessel stud, has gripper jaws which when the tensioner is lowered into engagement with the upper end of the stud are moved inwards to grip the upper end and which when the tensioner is lifted move outward to release the upper end. (author)

  4. A Method for Estimating Urban Background Concentrations in Support of Hybrid Air Pollution Modeling for Environmental Health Studies

    Directory of Open Access Journals (Sweden)

    Saravanan Arunachalam

    2014-10-01

    Full Text Available Exposure studies rely on detailed characterization of air quality, either from sparsely located routine ambient monitors or from central monitoring sites that may lack spatial representativeness. Alternatively, some studies use models of various complexities to characterize local-scale air quality, but often with poor representation of background concentrations. A hybrid approach that addresses this drawback combines a regional-scale model to provide background concentrations and a local-scale model to assess impacts of local sources. However, this approach may double-count sources in the study regions. To address these limitations, we carefully define the background concentration as the concentration that would be measured if local sources were not present, and to estimate these background concentrations we developed a novel technique that combines space-time ordinary kriging (STOK of observations with outputs from a detailed chemistry-transport model with local sources zeroed out. We applied this technique to support an exposure study in Detroit, Michigan, for several pollutants (including NOx and PM2.5, and evaluated the estimated hybrid concentrations (calculated by combining the background estimates that addresses this issue of double counting with local-scale dispersion model estimates using observations. Our results demonstrate the strength of this approach specifically by eliminating the problem of double-counting reported in previous hybrid modeling approaches leading to improved estimates of background concentrations, and further highlight the relative importance of NOx vs. PM2.5 in their relative contributions to total concentrations. While a key limitation of this approach is the requirement for another detailed model simulation to avoid double-counting, STOK improves the overall characterization of background concentrations at very fine spatial scales.

  5. On the q-Weibull distribution for reliability applications: An adaptive hybrid artificial bee colony algorithm for parameter estimation

    International Nuclear Information System (INIS)

    Xu, Meng; Droguett, Enrique López; Lins, Isis Didier; Chagas Moura, Márcio das

    2017-01-01

    The q-Weibull model is based on the Tsallis non-extensive entropy and is able to model various behaviors of the hazard rate function, including bathtub curves, by using a single set of parameters. Despite its flexibility, the q-Weibull has not been widely used in reliability applications partly because of the complicated parameters estimation. In this work, the parameters of the q-Weibull are estimated by the maximum likelihood (ML) method. Due to the intricate system of nonlinear equations, derivative-based optimization methods may fail to converge. Thus, the heuristic optimization method of artificial bee colony (ABC) is used instead. To deal with the slow convergence of ABC, it is proposed an adaptive hybrid ABC (AHABC) algorithm that dynamically combines Nelder-Mead simplex search method with ABC for the ML estimation of the q-Weibull parameters. Interval estimates for the q-Weibull parameters, including confidence intervals based on the ML asymptotic theory and on bootstrap methods, are also developed. The AHABC is validated via numerical experiments involving the q-Weibull ML for reliability applications and results show that it produces faster and more accurate convergence when compared to ABC and similar approaches. The estimation procedure is applied to real reliability failure data characterized by a bathtub-shaped hazard rate. - Highlights: • Development of an Adaptive Hybrid ABC (AHABC) algorithm for q-Weibull distribution. • AHABC combines local Nelder-Mead simplex method with ABC to enhance local search. • AHABC efficiently finds the optimal solution for the q-Weibull ML problem. • AHABC outperforms ABC and self-adaptive hybrid ABC in accuracy and convergence speed. • Useful model for reliability data with non-monotonic hazard rate.

  6. Estimating the location and shape of hybrid zones

    DEFF Research Database (Denmark)

    Guedj, Benjamin; Guillot, Gilles

    2011-01-01

    We propose a new model to make use of georeferenced genetic data for inferring the location and shape of a hybrid zone. The model output includes the posterior distribution of a parameter that quantifies the width of the hybrid zone. The model proposed is implemented in the GUI and command‐line v...

  7. Development of corresponding states model for estimation of the surface tension of chemical compounds

    DEFF Research Database (Denmark)

    Gharagheizi, Farhad; Eslamimanesh, Ali; Sattari, Mehdi

    2013-01-01

    include critical temperature or temperature/critical volume/acentric factor/critical pressure/reduced temperature/reduced normal boiling point temperature/molecular weight of the compounds. Around 1,300 surface tension data of 118 random compounds are used for developing the first model (a four...

  8. Estimated Trans-Lamina Cribrosa Pressure Differences in Low-Teen and High-Teen Intraocular Pressure Normal Tension Glaucoma: The Korean National Health and Nutrition Examination Survey

    OpenAIRE

    Lee, Si Hyung; Kwak, Seung Woo; Kang, Eun Min; Kim, Gyu Ah; Lee, Sang Yeop; Bae, Hyoung Won; Seong, Gong Je; Kim, Chan Yun

    2016-01-01

    Background To investigate the association between estimated trans-lamina cribrosa pressure difference (TLCPD) and prevalence of normal tension glaucoma (NTG) with low-teen and high-teen intraocular pressure (IOP) using a population-based study design. Methods A total of 12,743 adults (? 40 years of age) who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) from 2009 to 2012 were included. Using a previously developed formula, cerebrospinal fluid pressure (C...

  9. Aerodynamic Profiles of Women with Muscle Tension Dysphonia/Aphonia

    Science.gov (United States)

    Gillespie, Amanda I.; Gartner-Schmidt, Jackie; Rubinstein, Elaine N.; Abbott, Katherine Verdolini

    2013-01-01

    Purpose: In this study, the authors aimed to (a) determine whether phonatory airflows and estimated subglottal pressures (est-P[subscript sub]) for women with primary muscle tension dysphonia/aphonia (MTD/A) differ from those for healthy speakers; (b) identify different aerodynamic profile patterns within the MTD/A subject group; and (c) determine…

  10. A highly precise frequency-based method for estimating the tension of an inclined cable with unknown boundary conditions

    Science.gov (United States)

    Ma, Lin

    2017-11-01

    This paper develops a method for precisely determining the tension of an inclined cable with unknown boundary conditions. First, the nonlinear motion equation of an inclined cable is derived, and a numerical model of the motion of the cable is proposed using the finite difference method. The proposed numerical model includes the sag-extensibility, flexural stiffness, inclination angle and rotational stiffness at two ends of the cable. Second, the influence of the dynamic parameters of the cable on its frequencies is discussed in detail, and a method for precisely determining the tension of an inclined cable is proposed based on the derivatives of the eigenvalues of the matrices. Finally, a multiparameter identification method is developed that can simultaneously identify multiple parameters, including the rotational stiffness at two ends. This scheme is applicable to inclined cables with varying sag, varying flexural stiffness and unknown boundary conditions. Numerical examples indicate that the method provides good precision. Because the parameters of cables other than tension (e.g., the flexural stiffness and rotational stiffness at the ends) are not accurately known in practical engineering, the multiparameter identification method could further improve the accuracy of cable tension measurements.

  11. Uniaxial Tension Test of Slender Reinforced Early Age Concrete Members

    Directory of Open Access Journals (Sweden)

    Wenbo Zhang

    2011-08-01

    Full Text Available The present study aims to obtain the tensile properties of early age concrete based on a uniaxial tension test employing RC slender members. First, the paper shows that concrete strain is equal to the strain of rebar at the mid-span of the RC member. The tensile Young’s modulus and the strain capacity of early age concrete are estimated using strain measurements. The experiment indicated that the tensile Young’s modulus at an early age is higher than the compressive modulus. This observation was similar to one found in a previous investigation which used a direct tension test of early age concrete. Moreover, the paper describes how an empirical equation for mature concrete can be applied to the relation between uniaxial tensile strength and splitting tensile strength even in early age concrete. Based on a uniaxial tension test, the paper proposes an empirical equation for the relationship between standard bond stresses and relative slip.

  12. Estimating SPT-N Value Based on Soil Resistivity using Hybrid ANN-PSO Algorithm

    Science.gov (United States)

    Nur Asmawisham Alel, Mohd; Ruben Anak Upom, Mark; Asnida Abdullah, Rini; Hazreek Zainal Abidin, Mohd

    2018-04-01

    Standard Penetration Resistance (N value) is used in many empirical geotechnical engineering formulas. Meanwhile, soil resistivity is a measure of soil’s resistance to electrical flow. For a particular site, usually, only a limited N value data are available. In contrast, resistivity data can be obtained extensively. Moreover, previous studies showed evidence of a correlation between N value and resistivity value. Yet, no existing method is able to interpret resistivity data for estimation of N value. Thus, the aim is to develop a method for estimating N-value using resistivity data. This study proposes a hybrid Artificial Neural Network-Particle Swarm Optimization (ANN-PSO) method to estimate N value using resistivity data. Five different ANN-PSO models based on five boreholes were developed and analyzed. The performance metrics used were the coefficient of determination, R2 and mean absolute error, MAE. Analysis of result found that this method can estimate N value (R2 best=0.85 and MAEbest=0.54) given that the constraint, Δ {\\bar{l}}ref, is satisfied. The results suggest that ANN-PSO method can be used to estimate N value with good accuracy.

  13. Non-linear belt transient analysis. A hybrid model for numerical belt conveyor simulation

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, A. [Scientific Solutions, Inc., Aurora, CO (United States)

    2008-07-01

    Frictional and rolling losses along a running conveyor are discussed due to their important influence on wave propagation during starting and stopping. Hybrid friction models allow belt rubber losses and material flexing to be included in the initial tension calculations prior to any dynamic analysis. Once running tensions are defined, a numerical integration method using non-linear stiffness gradients is used to generate transient forces during starting and stopping. A modified Euler integration technique is used to simulate the entire starting and stopping cycle in less than 0.1 seconds. The procedure enables a faster scrutiny of unforeseen conveyor design issues such as low belt tension zones and high forces at drives. (orig.)

  14. General definition of gravitational tension

    International Nuclear Information System (INIS)

    Harmark, T.; Obers, N.A.

    2004-01-01

    In this note we give a general definition of the gravitational tension in a given asymptotically translationally-invariant spatial direction of a space-time. The tension is defined via the extrinsic curvature in analogy with the Hawking-Horowitz definition of energy. We show the consistency with the ADM tension formulas for asymptotically-flat space-times, in particular for Kaluza-Klein black hole solutions. Moreover, we apply the general tension formula to near-extremal branes, constituting a check for non-asymptotically flat space-times. (author)

  15. Spontaneous oscillation of tension and sarcomere length in skeletal myofibrils. Microscopic measurement and analysis.

    Science.gov (United States)

    Anazawa, T; Yasuda, K; Ishiwata, S

    1992-05-01

    We have devised a simple method for measuring tension development of single myofibrils by micromanipulation with a pair of glass micro-needles. The tension was estimated from the deflection of a flexible needle under an inverted phase-contrast microscope equipped with an image processor, so that the tension development is always accompanied by the shortening of the myofibril (auxotonic condition) in the present setup. The advantage of this method is that the measurement of tension (1/30 s for time resolution and about 0.05 micrograms for accuracy of tension measurement; 0.05 microns as a spatial resolution for displacement of the micro-needle) and the observation of sarcomere structure are possible at the same time, and the technique to hold myofibrils, even single myofibrils, is very simple. This method has been applied to study the tension development of glycerinated skeletal myofibrils under the condition where spontaneous oscillation of sarcomeres is induced, i.e., the coexistence of MgATP, MgADP and inorganic phosphate without free Ca2+. Under this condition, we found that the tension of myofibrils spontaneously oscillates accompanied by the oscillation of sarcomere length with a main period of a few seconds; the period was lengthened and shortened with stretch and release of myofibrils. A possible mechanism of the oscillation is discussed.

  16. Tension type headache

    Directory of Open Access Journals (Sweden)

    Debashish Chowdhury

    2012-01-01

    Full Text Available Tension type headaches are common in clinical practice. Earlier known by various names, the diagnosis has had psychological connotations. Recent evidence has helped clarify the neurobiological basis and the disorder is increasingly considered more in the preview of neurologists. The classification, clinical features, differential diagnosis and treatment of tension type headache are discussed in this paper.

  17. Load estimator-based hybrid controller design for two-interleaved boost converter dedicated to renewable energy and automotive applications.

    Science.gov (United States)

    Bougrine, Mohamed; Benmiloud, Mohammed; Benalia, Atallah; Delaleau, Emmanuel; Benbouzid, Mohamed

    2017-01-01

    This paper is devoted to the development of a hybrid controller for a two-interleaved boost converter dedicated to renewable energy and automotive applications. The control requirements, resumed in fast transient and low input current ripple, are formulated as a problem of fast stabilization of a predefined optimal limit cycle, and solved using hybrid automaton formalism. In addition, a real time estimation of the load is developed using an algebraic approach for online adjustment of the hybrid controller. Mathematical proofs are provided with simulations to illustrate the effectiveness and the robustness of the proposed controller despite different disturbances. Furthermore, a fuel cell system supplying a resistive load through a two-interleaved boost converter is also highlighted. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Relación entre cefalea tensional y disfunción familiar en una unidad de medicina familiar Relation of tension headache and family dysfunction in a family medicine unit

    Directory of Open Access Journals (Sweden)

    Jorge Octavio Carvajal Rivera

    2009-03-01

    Full Text Available La cefalea tensional es la forma más frecuente de cefalea primaria. Este trabajo se realizó con el objetivo de estimar si existe asociación entre cefalea tensional y disfunción familiar. 60 pacientes evaluaron sus familias a través del cuestionario FF-SIL de funcionamiento familiar. La cefalea tensional fue más frecuente en miembros de familias disfuncionales que en aquellos que provenían de familias funcionales (p=.028. Fueron frecuentes las manifestaciones clínicas relacionadas con estrés postraumático en el paciente problema, existe un complejo y conflictual ambiente familiar que incluye a estos enfermos, lo que nos sugiere el uso de los recursos de la familia como opción terapéutica aún pobremente explorada.Tension headache is the more frequent presentation of primary cephalagia. Aim of this paper is to estimate if there is an association between tension headache and familial dysfunction. Sixty patients evaluated their families by through FF-SIL questionnaire of familial performance. Tension headache was more frequent in members of dysfunctional families than in those from functional families (p = .028. Clinical manifestations related to post-traumatic stress were frequent, there is a familial complex and difficult environment including these sick persons, suggesting us the use of family resources as therapeutical option not very explored yet.

  19. A novel chitosan 3-amino-1,2,4-triazole hybrid: Preparation and its effects on cotton fabric properties

    Directory of Open Access Journals (Sweden)

    Asmaa Aboelnaga

    2017-09-01

    Full Text Available A hybrid of chitosan and 3-amino-1,2,4-triazole was prepared using the semi-wet method, which allows for the adsorption of the triazole molecules on the chitosan surface. Moreover, an easy method for applying this hybrid to cotton fabric was established. The tensional strength, uniformity and compatibility of the hybrid components in forming of a strong film were studied using different variables, including the chitosan 3-amino-1,2,4-triazole ratio, fixation temperature and time. The loading of the hybrid onto the fabric in the absence and presence of cross linker (butane tetra carboxylic acid was also studied. The best conditions for preparing the hybrid was a 1:4 molar ratio of chitosan to 3-amino-1,2,4-triazole at 60 °C for 240 min, and those for the application of the hybrid to cotton fabric were a 1:1 molar ratio at 150 °C with a 5 min curing time. Both hybrid and treated cotton fabrics were characterized using FTIR, SEM, TGA, and DSC as well as the nitrogen content and tensional strength of the treated cotton. Finally, the antibacterial activities of the treated cotton fabric display 100% activity and excellent effects against gram-positive bacteria, Staphylococcus aureus and gram-negative Escherichia coli.

  20. Design of Passive Power Filter for Hybrid Series Active Power Filter using Estimation, Detection and Classification Method

    Science.gov (United States)

    Swain, Sushree Diptimayee; Ray, Pravat Kumar; Mohanty, K. B.

    2016-06-01

    This research paper discover the design of a shunt Passive Power Filter (PPF) in Hybrid Series Active Power Filter (HSAPF) that employs a novel analytic methodology which is superior than FFT analysis. This novel approach consists of the estimation, detection and classification of the signals. The proposed method is applied to estimate, detect and classify the power quality (PQ) disturbance such as harmonics. This proposed work deals with three methods: the harmonic detection through wavelet transform method, the harmonic estimation by Kalman Filter algorithm and harmonic classification by decision tree method. From different type of mother wavelets in wavelet transform method, the db8 is selected as suitable mother wavelet because of its potency on transient response and crouched oscillation at frequency domain. In harmonic compensation process, the detected harmonic is compensated through Hybrid Series Active Power Filter (HSAPF) based on Instantaneous Reactive Power Theory (IRPT). The efficacy of the proposed method is verified in MATLAB/SIMULINK domain and as well as with an experimental set up. The obtained results confirm the superiority of the proposed methodology than FFT analysis. This newly proposed PPF is used to make the conventional HSAPF more robust and stable.

  1. Estimation of heterosis in yield and yield attributing traits in single cross hybrids of maize

    Directory of Open Access Journals (Sweden)

    Hari Prasad Sharma

    2016-12-01

    Full Text Available A field experiment was conducted at National Maize Research Program, Rampur, Chitwan, Nepal during winter season from 6th October, 2015 to 5th March 2016 to estimate different heterosis on single cross maize hybrids . Thirteen maize hybrids were tested randomized complete block design with three replications. Hybrid namely RML-98/RL-105 gave the highest standard heterosis (57.5% for grain yield over CP-666 followed by RML-4/NML-2 (32.6%, RML-95/RL-105 (29% and RML-5/RL-105 (20.6%. The hybrid RML-98/RL-105 produced the highest standard heterosis (75.1% for grain yield over Rajkumar followed by RML-4/NML-2(50.2%, RML-95/RL-105(46.6%, RML-5/RL-105 and (35.7%. Mid and better parent heterosis were significantly higher for yield and yield attributes viz. ear length, ear diameter, no of kernel row per ear, no of kernel per row and test weight. The highest positive mid-parent heterosis for grain yield was found in RML-98/RL-105 followed by RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2. For the grain yield the better parent heterosis was the highest in RML-98/RL-105, followed by RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2. These results suggested that maize production can be maximized by cultivating hybrids namely RML-98/RL-105, RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2 .

  2. Using velocity dispersion to estimate halo mass: Is the Local Group in tension with ΛCDM?

    Science.gov (United States)

    Elahi, Pascal J.; Power, Chris; Lagos, Claudia del P.; Poulton, Rhys; Robotham, Aaron S. G.

    2018-06-01

    Satellite galaxies are commonly used as tracers to measure the line-of-sight (LOS)velocity dispersion (σLOS) of the dark matter halo associated with their central galaxy, and thereby to estimate the halo's mass. Recent observational dispersion estimates of the Local Group, including the Milky Way and M31, suggest σ ˜50 km s-1, which is surprisingly low when compared to the theoretical expectation of σ ˜100 km s-1 for systems of their mass. Does this pose a problem for Lambda cold dark matter (ΛCDM)? We explore this tension using the SURFS suite of N-body simulations, containing over 10000 (sub)haloes with well tracked orbits. We test how well a central galaxy's host halo velocity dispersion can be recovered by sampling σLOS of subhaloes and surrounding haloes. Our results demonstrate that σLOS is biased mass proxy. We define an optimal window in vLOS and projected distance (Dp) - 0.5 ≲ Dp/Rvir ≲ 1.0 and vLOS ≲ 0.5Vesc, where Rvir is the virial radius and Vesc is the escape velocity - such that the scatter in LOS to halo dispersion is minimized - σLOS = (0.5 ± 0.1)σv, H. We argue that this window should be used to measure LOS dispersions as a proxy for mass, as it minimises scatter in the σLOS-Mvir relation. This bias also naturally explains the results from McConnachie (2012), who used similar cuts when estimating σLOS, LG, producing a bias of σLG = (0.44 ± 0.14)σv, H. We conclude that the Local Group's velocity dispersion does not pose a problem for ΛCDM and has a mass of log M_{LG, vir}/M_{⊙}=12.0^{+0.8}_{-2.0}.

  3. Managers as consultants:The hybridity and tensions of neo-bureaucratic management

    OpenAIRE

    Sturdy, Andrew J; Wright, Christopher; Wylie, Nick

    2016-01-01

    The nature and extent of changes in management remain subject to debate, especially around the notion of post-bureaucracy. Most research concedes that, partly in response to critiques of bureaucracy, some change has occurred, but towards hybrid or neo-bureaucratic practices which retain core elements of bureaucratic organisation. However, both the mechanisms through which these changes have occurred and their outcomes have received less attention. This paper addresses these issues by focusing...

  4. Estimation of Entropy Generation for Ag-MgO/Water Hybrid Nanofluid Flow through Rectangular Minichannel by Using Artificial Neural Network

    OpenAIRE

    Uysal, Cuneyt; Korkmaz, Mehmet Erdi

    2018-01-01

    The convective heat transfer andentropy generation characteristics of Ag-MgO/water hybrid nanofluid flowthrough rectangular minichannel were numerically investigated. The Reynoldsnumber was in the range of 200 to 2000 and different nanoparticle volume fractionswere varied between = 0.005 and 0.02. In addition, ArtificialNeural Network was used to create a model for estimating of entropy generationof Ag-MgO/water hybrid nanofluid flow. As a result, it was found th...

  5. Clinical manifestations of tension pneumothorax: protocol for a systematic review and meta-analysis

    Science.gov (United States)

    2014-01-01

    Background Although health care providers utilize classically described signs and symptoms to diagnose tension pneumothorax, available literature sources differ in their descriptions of its clinical manifestations. Moreover, while the clinical manifestations of tension pneumothorax have been suggested to differ among subjects of varying respiratory status, it remains unknown if these differences are supported by clinical evidence. Thus, the primary objective of this study is to systematically describe and contrast the clinical manifestations of tension pneumothorax among patients receiving positive pressure ventilation versus those who are breathing unassisted. Methods/Design We will search electronic bibliographic databases (MEDLINE, PubMed, EMBASE, and the Cochrane Database of Systematic Reviews) and clinical trial registries from their first available date as well as personal files, identified review articles, and included article bibliographies. Two investigators will independently screen identified article titles and abstracts and select observational (cohort, case–control, and cross-sectional) studies and case reports and series that report original data on clinical manifestations of tension pneumothorax. These investigators will also independently assess risk of bias and extract data. Identified data on the clinical manifestations of tension pneumothorax will be stratified according to whether adult or pediatric study patients were receiving positive pressure ventilation or were breathing unassisted, as well as whether the two investigators independently agreed that the clinical condition of the study patient(s) aligned with a previously published tension pneumothorax working definition. These data will then be summarized using a formal narrative synthesis alongside a meta-analysis of observational studies and then case reports and series where possible. Pooled or combined estimates of the occurrence rate of clinical manifestations will be calculated using

  6. Soft-tissue tension total knee arthroplasty.

    Science.gov (United States)

    Asano, Hiroshi; Hoshino, Akiho; Wilton, Tim J

    2004-08-01

    It is far from clear how best to define the proper strength of soft-tissue tensioning in total knee arthroplasty (TKA). We attached a torque driver to the Monogram balancer/tensor device and measured soft-tissue tension in full extension and 90 degrees flexion during TKA. In our surgical procedure, when we felt proper soft-tissue tension was being applied, the mean distraction force was noted to be 126N in extension and 121N in flexion. There was no significant correlation between soft-tissue tension and the postoperative flexion angle finally achieved. To the best of our knowledge, this is the first study to assess the actual distraction forces in relation to soft-tissue tension in TKA. Further study may reveal the most appropriate forces to achieve proper soft-tissue tension in the wide variety of circumstances presenting at knee arthroplasty.

  7. Spontaneous tension haemopneumothorax

    OpenAIRE

    Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

    2008-01-01

    Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such c...

  8. Periodic orbits of hybrid systems and parameter estimation via AD

    International Nuclear Information System (INIS)

    Guckenheimer, John; Phipps, Eric Todd; Casey, Richard

    2004-01-01

    Rhythmic, periodic processes are ubiquitous in biological systems; for example, the heart beat, walking, circadian rhythms and the menstrual cycle. Modeling these processes with high fidelity as periodic orbits of dynamical systems is challenging because: (1) (most) nonlinear differential equations can only be solved numerically; (2) accurate computation requires solving boundary value problems; (3) many problems and solutions are only piecewise smooth; (4) many problems require solving differential-algebraic equations; (5) sensitivity information for parameter dependence of solutions requires solving variational equations; and (6) truncation errors in numerical integration degrade performance of optimization methods for parameter estimation. In addition, mathematical models of biological processes frequently contain many poorly-known parameters, and the problems associated with this impedes the construction of detailed, high-fidelity models. Modelers are often faced with the difficult problem of using simulations of a nonlinear model, with complex dynamics and many parameters, to match experimental data. Improved computational tools for exploring parameter space and fitting models to data are clearly needed. This paper describes techniques for computing periodic orbits in systems of hybrid differential-algebraic equations and parameter estimation methods for fitting these orbits to data. These techniques make extensive use of automatic differentiation to accurately and efficiently evaluate derivatives for time integration, parameter sensitivities, root finding and optimization. The boundary value problem representing a periodic orbit in a hybrid system of differential algebraic equations is discretized via multiple-shooting using a high-degree Taylor series integration method (GM00, Phi03). Numerical solutions to the shooting equations are then estimated by a Newton process yielding an approximate periodic orbit. A metric is defined for computing the distance

  9. Tension headache.

    Science.gov (United States)

    Ziegler, D K

    1978-05-01

    Headache is an extremely common symptom, and many headaches undoubtedly have a relationship to stressful situations. The clear definition, however, of a "tension headache" complex and its differentiation from migraine in some patients is difficult. The problems are in the identification of a specific headache pattern induced by stress or "tension" and the relationship of the symptom to involuntary contraction of neck and scalp muscles. Treatment consists of analgesics and occasionally mild tranquilizers. Psychotherapy consists of reassurance and often other supportive measures, including modification of life styles. Various feedback techniques have been reported of value, but their superiority to suggestion and hypnosis is still problematic.

  10. Evaluation of Repair Tension in Arthroscopic Rotator Cuff Repair: Does It Really Matter to the Integrity of the Rotator Cuff?

    Science.gov (United States)

    Kim, Do Hoon; Jang, Young Hoon; Choi, Young Eun; Lee, Hwa-Ryeong; Kim, Sae Hoon

    2016-11-01

    Repair tension of a torn rotator cuff can affect healing after repair. However, a measurement of the actual tension during arthroscopic rotator cuff repair is not feasible. The relationship between repair tension and healing of a rotator cuff repair remains unclear. The purpose of this study was to evaluate the effect of repair tension on healing at the repair site. The hypothesis was that repair tension would be a major factor in determining the anatomic outcome of rotator cuff repair. Cohort study; Level of evidence, 2. Arthroscopic rotator cuff repairs (132 patients) for full-thickness rotator cuff tears were analyzed. An intraoperative model was designed for the estimation of repair tension using a tensiometer. Magnetic resonance imaging (MRI) was performed approximately 1 year (mean [±SD], 12.7 ± 3.2 months) postoperatively for the evaluation of healing at the repair site. Multivariable analysis was performed for tear size, amount of retraction, and fatty degeneration (FD) of rotator cuff muscles. The mean repair tension measured during the arthroscopic procedure was 28.5 ± 23.1 N. There was a statistically significant correlation between tension and tear size (Pearson correlation coefficient [PCC], 0.529; P repair tension also showed a significant inverse correlation with healing at the repair site (SCC, 0.195; P = .025). However, when sex, age, tear size, amount of retraction, tendon quality, and FD of rotator cuff muscles were included for multivariable logistic regression analysis, only FD of the infraspinatus showed an association with the anatomic outcome of repair (Exp(B) = 0.596; P = .010). Our intraoperative model for the estimation of rotator cuff repair tension showed an inverse correlation of repair tension with healing at the repair site, suggesting that complete healing is less likely with high-tension repairs. A significant association was observed on MRI between a high level of FD of the infraspinatus and repaired tendon integrity. © 2016

  11. Tensions in Distributed Leadership

    Science.gov (United States)

    Ho, Jeanne; Ng, David

    2017-01-01

    Purpose: This article proposes the utility of using activity theory as an analytical lens to examine the theoretical construct of distributed leadership, specifically to illuminate tensions encountered by leaders and how they resolved these tensions. Research Method: The study adopted the naturalistic inquiry approach of a case study of an…

  12. OligoHeatMap (OHM): an online tool to estimate and display hybridizations of oligonucleotides onto DNA sequences.

    Science.gov (United States)

    Croce, Olivier; Chevenet, François; Christen, Richard

    2008-07-01

    The efficiency of molecular methods involving DNA/DNA hybridizations depends on the accurate prediction of the melting temperature (T(m)) of the duplex. Many softwares are available for T(m) calculations, but difficulties arise when one wishes to check if a given oligomer (PCR primer or probe) hybridizes well or not on more than a single sequence. Moreover, the presence of mismatches within the duplex is not sufficient to estimate specificity as it does not always significantly decrease the T(m). OHM (OligoHeatMap) is an online tool able to provide estimates of T(m) for a set of oligomers and a set of aligned sequences, not only as text files of complete results but also in a graphical way: T(m) values are translated into colors and displayed as a heat map image, either stand alone or to be used by softwares such as TreeDyn to be included in a phylogenetic tree. OHM is freely available at http://bioinfo.unice.fr/ohm/, with links to the full source code and online help.

  13. Tension pneumocephalus: Mount Fuji sign

    Directory of Open Access Journals (Sweden)

    Pulastya Sanyal

    2015-01-01

    Full Text Available A 13-year-old male was operated for a space occupying lesion in the brain. A noncontrast computed tomography scan done in the late postoperative period showed massive subdural air collection causing compression of bilateral frontal lobes with widening of interhemispheric fissure and the frontal lobes acquiring a peak like configuration - causing tension pneumocephalus-"Mount Fuji sign." Tension pneumocephalus occurs when air enters the extradural or intradural spaces in sufficient volume to exert a mass or pressure effect on the brain, leading to brain herniation. Tension pneumocephalus is a surgical emergency, which needs immediate intervention in the form of decompression of the cranial cavity by a burr hole or needle aspiration. The Mount Fuji sign differentiates tension pneumocephalus from pneumocephalus.

  14. Numerical modeling of hybrid fiber-reinforced concrete (hyfrc)

    International Nuclear Information System (INIS)

    Hameed, R.; Turatsinze, A.

    2015-01-01

    A model for numerical simulation of mechanical response of concrete reinforced with slipping and non slipping metallic fibers in hybrid form is presented in this paper. Constitutive law used to model plain concrete behaviour is based on plasticity and damage theories, and is capable to determine localized crack opening in three dimensional (3-D) systems. Behaviour law used for slipping metallic fibers is formulated based on effective stress carried by these fibers after when concrete matrix is cracked. A continuous approach is proposed to model the effect of addition of non-slipping metallic fibers in plain concrete. This approach considers the constitutive law of concrete matrix with increased fracture energy in tension obtained experimentally in direct tension tests on Fiber Reinforced Concrete (FRC). To simulate the mechanical behaviour of hybrid fiber-reinforced concrete (HyFRC), proposed approaches to model non-slipping metallic fibers and constitutive law of plain concrete and slipping fibers are used simultaneously without any additive equation. All the parameters used by the proposed model have physical meanings and are determined through experiments or drawn from literature. The model was implemented in Finite Element (FE) Code CASTEM and tested on FRC prismatic notched specimens in flexure. Model prediction showed good agreement with experimental results. (author)

  15. Feasibility study on the introduction of hybrid buses; Hybrid bus donyu kanosei chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The purpose of this research is to design pilot projects for introducing hybrid buses into the public transportation sector. This research also covers contents regarding hybrid buses with a trolley-collector motor and a diesel engine, to identify technical and economical problems and to analyze cost beneficiation using hybrid buses. The trolley parallel hybrid system has been employed for the feasibility study. This system has abundant operation results in Europe and the USA. Its battery is small or is not necessary, and the maintenance cost is also low. As a result of the feasibility study, reduction effects of CO2 emission were found out. When the CO2 generation at the power plant is not counted, the reduction effect was estimated to be 32% compared with the CO2 emission from diesel buses. When the CO2 generation at the power plant is considered, it was estimated to be 18%. The cost beneficiation was investigated for the cases of the transportations using trolley system surrounding a medium-scale terminal among large-scale housing development, tourist resort, and stations. The annual income is estimated to be larger than the annual payment in each case. It was found that the hybrid bus is economically established. 17 refs., 48 figs., 41 tabs.

  16. The effects of temperature and alkyl chain length on the density and surface tension of the imidazolium-based geminal dicationic ionic liquids

    International Nuclear Information System (INIS)

    Moosavi, Majid; Khashei, Fatemeh; Sharifi, Ali; Mirzaei, Mojtaba

    2017-01-01

    Highlights: • Surface tension and density of three GDILs were measured at different temperatures. • Surface entropy and surface enthalpy indicate the surface ordering in these GDILs. • Parachors and critical temperatures of these systems were estimated. • Results of GDILs were compared with the results of corresponding traditional MILs. • Relations between surface tension, density and viscosity of GDILs were demonstrated. - Abstract: Surface tensions and densities of three imidazolium-based geminal dicationic ionic liquids (GDILs) with the bis(trifluoromethylsulfonyl)imide, [NTf 2 ] − , as a common anion, have been measured at ambient pressure at different temperatures in the range from 296.00 to 353.15 K. The surface thermodynamic functions such as surface entropy and surface enthalpy were derived from the temperature dependence of surface tension which indicated the surface ordering in these GDILs. As well as the parachor, the critical temperatures of these systems have been estimated using the Guggenheim and Eotvos correlations. In each case, the results of GDILs have been compared with the results of corresponding traditional monocationic ILs (MILs). Also, the relations between the surface tension and density and also surface tension and viscosity data have been demonstrated and discussed.

  17. Vacuum phase transition solves the H0 tension

    Science.gov (United States)

    Di Valentino, Eleonora; Linder, Eric V.; Melchiorri, Alessandro

    2018-02-01

    Taking the Planck cosmic microwave background data and the more direct Hubble constant measurement data as unaffected by systematic offsets, the values of the Hubble constant H0 interpreted within the Λ CDM cosmological constant and cold dark matter cosmological model are in ˜3.3 σ tension. We show that the Parker vacuum metamorphosis (VM) model, physically motivated by quantum gravitational effects and with the same number of parameters as Λ CDM , can remove the H0 tension and can give an improved fit to data (up to a mean Δ χ2=-7.5 ). It also ameliorates tensions with weak lensing data and the high redshift Lyman alpha forest data. Considering Bayesian evidence, we found in the case of the Planck data set alone positive evidence for a VM model against a cosmological constant both in the six- and nine-parameter framework. When the R16 data set is also considered, we found a strong evidence for the VM model against a cosmological constant in nine-parameter space. We separately consider a scale-dependent scaling of the gravitational lensing amplitude, such as provided by modified gravity, neutrino mass, or cold dark energy, motivated by the somewhat different cosmological parameter estimates for low and high CMB multipoles. We find that no such scale dependence is preferred.

  18. A HYBRID METHOD IN VEGETATION HEIGHT ESTIMATION USING POLINSAR IMAGES OF CAMPAIGN BIOSAR

    Directory of Open Access Journals (Sweden)

    S. Dehnavi

    2015-12-01

    Full Text Available Recently, there have been plenty of researches on the retrieval of forest height by PolInSAR data. This paper aims at the evaluation of a hybrid method in vegetation height estimation based on L-band multi-polarized air-borne SAR images. The SAR data used in this paper were collected by the airborne E-SAR system. The objective of this research is firstly to describe each interferometry cross correlation as a sum of contributions corresponding to single bounce, double bounce and volume scattering processes. Then, an ESPIRIT (Estimation of Signal Parameters via Rotational Invariance Techniques algorithm is implemented, to determine the interferometric phase of each local scatterer (ground and canopy. Secondly, the canopy height is estimated by phase differencing method, according to the RVOG (Random Volume Over Ground concept. The applied model-based decomposition method is unrivaled, as it is not limited to specific type of vegetation, unlike the previous decomposition techniques. In fact, the usage of generalized probability density function based on the nth power of a cosine-squared function, which is characterized by two parameters, makes this method useful for different vegetation types. Experimental results show the efficiency of the approach for vegetation height estimation in the test site.

  19. a Hybrid Method in Vegetation Height Estimation Using Polinsar Images of Campaign Biosar

    Science.gov (United States)

    Dehnavi, S.; Maghsoudi, Y.

    2015-12-01

    Recently, there have been plenty of researches on the retrieval of forest height by PolInSAR data. This paper aims at the evaluation of a hybrid method in vegetation height estimation based on L-band multi-polarized air-borne SAR images. The SAR data used in this paper were collected by the airborne E-SAR system. The objective of this research is firstly to describe each interferometry cross correlation as a sum of contributions corresponding to single bounce, double bounce and volume scattering processes. Then, an ESPIRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) algorithm is implemented, to determine the interferometric phase of each local scatterer (ground and canopy). Secondly, the canopy height is estimated by phase differencing method, according to the RVOG (Random Volume Over Ground) concept. The applied model-based decomposition method is unrivaled, as it is not limited to specific type of vegetation, unlike the previous decomposition techniques. In fact, the usage of generalized probability density function based on the nth power of a cosine-squared function, which is characterized by two parameters, makes this method useful for different vegetation types. Experimental results show the efficiency of the approach for vegetation height estimation in the test site.

  20. Do the contact angle and line tension of surface-attached droplets depend on the radius of curvature?

    Science.gov (United States)

    Das, Subir K; Egorov, Sergei A; Virnau, Peter; Winter, David; Binder, Kurt

    2018-06-27

    Results from Monte Carlo simulations of wall-attached droplets in the three-dimensional Ising lattice gas model and in a symmetric binary Lennard-Jones fluid, confined by antisymmetric walls, are analyzed, with the aim to estimate the dependence of the contact angle [Formula: see text] on the droplet radius [Formula: see text] of curvature. Sphere-cap shape of the wall-attached droplets is assumed throughout. An approach, based purely on 'thermodynamic' observables, e.g. chemical potential, excess density due to the droplet, etc, is used, to avoid ambiguities in the decision which particles belong (or do not belong, respectively) to the droplet. It is found that the results are compatible with a variation [Formula: see text], [Formula: see text] being the contact angle in the thermodynamic limit ([Formula: see text]). The possibility to use such results to estimate the excess free energy related to the contact line of the droplet, namely the line tension, at the wall, is discussed. Various problems that hamper this approach and were not fully recognized in previous attempts to extract the line tension are identified. It is also found that the dependence of wall tensions on the difference of chemical potential of the droplet from that at the bulk coexistence provides effectively a change of the contact angle of similar magnitude. The simulation approach yields precise estimates for the excess density due to wall-attached droplets and the corresponding free energy excess, relative to a system without a droplet at the same chemical potential. It is shown that this information suffices to estimate nucleation barriers, not affected by ambiguities on droplet shape, contact angle and line tension.

  1. Shape accuracy optimization for cable-rib tension deployable antenna structure with tensioned cables

    Science.gov (United States)

    Liu, Ruiwei; Guo, Hongwei; Liu, Rongqiang; Wang, Hongxiang; Tang, Dewei; Song, Xiaoke

    2017-11-01

    Shape accuracy is of substantial importance in deployable structures as the demand for large-scale deployable structures in various fields, especially in aerospace engineering, increases. The main purpose of this paper is to present a shape accuracy optimization method to find the optimal pretensions for the desired shape of cable-rib tension deployable antenna structure with tensioned cables. First, an analysis model of the deployable structure is established by using finite element method. In this model, geometrical nonlinearity is considered for the cable element and beam element. Flexible deformations of the deployable structure under the action of cable network and tensioned cables are subsequently analyzed separately. Moreover, the influence of pretension of tensioned cables on natural frequencies is studied. Based on the results, a genetic algorithm is used to find a set of reasonable pretension and thus minimize structural deformation under the first natural frequency constraint. Finally, numerical simulations are presented to analyze the deployable structure under two kinds of constraints. Results show that the shape accuracy and natural frequencies of deployable structure can be effectively improved by pretension optimization.

  2. Spontaneous tension haemopneumothorax.

    Science.gov (United States)

    Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

    2008-10-31

    We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported.Aetiology and current approach to spontaneous haemothorax are discussed briefly.

  3. Membrane tension regulates clathrin-coated pit dynamics

    Science.gov (United States)

    Liu, Allen

    2014-03-01

    Intracellular organization depends on close communication between the extracellular environment and a network of cytoskeleton filaments. The interactions between cytoskeletal filaments and the plasma membrane lead to changes in membrane tension that in turns help regulate biological processes. Endocytosis is thought to be stimulated by low membrane tension and the removal of membrane increases membrane tension. While it is appreciated that the opposing effects of exocytosis and endocytosis have on keeping plasma membrane tension to a set point, it is not clear how membrane tension affects the dynamics of clathrin-coated pits (CCPs), the individual functional units of clathrin-mediated endocytosis. Furthermore, although it was recently shown that actin dynamics counteracts membrane tension during CCP formation, it is not clear what roles plasma membrane tension plays during CCP initiation. Based on the notion that plasma membrane tension is increased when the membrane area increases during cell spreading, we designed micro-patterned surfaces of different sizes to control the cell spreading sizes. Total internal reflection fluorescence microscopy of living cells and high content image analysis were used to quantify the dynamics of CCPs. We found that there is an increased proportion of CCPs with short (<20s) lifetime for cells on larger patterns. Interestingly, cells on larger patterns have higher CCP initiation density, an effect unexpected based on the conventional view of decreasing endocytosis with increasing membrane tension. Furthermore, by analyzing the intensity profiles of CCPs that were longer-lived, we found CCP intensity decreases with increasing cell size, indicating that the CCPs are smaller with increasing membrane tension. Finally, disruption of actin dynamics significantly increased the number of short-lived CCPs, but also decreased CCP initiation rate. Together, our study reveals new mechanistic insights into how plasma membrane tension regulates

  4. Estimates for Genetic Variance Components in Reciprocal Recurrent Selection in Populations Derived from Maize Single-Cross Hybrids

    Directory of Open Access Journals (Sweden)

    Matheus Costa dos Reis

    2014-01-01

    Full Text Available This study was carried out to obtain the estimates of genetic variance and covariance components related to intra- and interpopulation in the original populations (C0 and in the third cycle (C3 of reciprocal recurrent selection (RRS which allows breeders to define the best breeding strategy. For that purpose, the half-sib progenies of intrapopulation (P11 and P22 and interpopulation (P12 and P21 from populations 1 and 2 derived from single-cross hybrids in the 0 and 3 cycles of the reciprocal recurrent selection program were used. The intra- and interpopulation progenies were evaluated in a 10×10 triple lattice design in two separate locations. The data for unhusked ear weight (ear weight without husk and plant height were collected. All genetic variance and covariance components were estimated from the expected mean squares. The breakdown of additive variance into intrapopulation and interpopulation additive deviations (στ2 and the covariance between these and their intrapopulation additive effects (CovAτ found predominance of the dominance effect for unhusked ear weight. Plant height for these components shows that the intrapopulation additive effect explains most of the variation. Estimates for intrapopulation and interpopulation additive genetic variances confirm that populations derived from single-cross hybrids have potential for recurrent selection programs.

  5. Dead space and slope indices from the expiratory carbon dioxide tension-volume curve

    NARCIS (Netherlands)

    A.H. Kars (Alice); J.M. Bogaard (Jan); Th. Stijnen (Theo); J. de Vries; A.F.M. Verbraak (Anton); C. Hilvering

    1997-01-01

    textabstractThe slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate

  6. Application of a hybrid model to reduce bias and improve precision in population estimates for elk (Cervus elaphus) inhabiting a cold desert ecosystem

    Science.gov (United States)

    Schoenecker, Kathryn A.; Lubow, Bruce C.

    2016-01-01

    Accurately estimating the size of wildlife populations is critical to wildlife management and conservation of species. Raw counts or “minimum counts” are still used as a basis for wildlife management decisions. Uncorrected raw counts are not only negatively biased due to failure to account for undetected animals, but also provide no estimate of precision on which to judge the utility of counts. We applied a hybrid population estimation technique that combined sightability modeling, radio collar-based mark-resight, and simultaneous double count (double-observer) modeling to estimate the population size of elk in a high elevation desert ecosystem. Combining several models maximizes the strengths of each individual model while minimizing their singular weaknesses. We collected data with aerial helicopter surveys of the elk population in the San Luis Valley and adjacent mountains in Colorado State, USA in 2005 and 2007. We present estimates from 7 alternative analyses: 3 based on different methods for obtaining a raw count and 4 based on different statistical models to correct for sighting probability bias. The most reliable of these approaches is a hybrid double-observer sightability model (model MH), which uses detection patterns of 2 independent observers in a helicopter plus telemetry-based detections of radio collared elk groups. Data were fit to customized mark-resight models with individual sighting covariates. Error estimates were obtained by a bootstrapping procedure. The hybrid method was an improvement over commonly used alternatives, with improved precision compared to sightability modeling and reduced bias compared to double-observer modeling. The resulting population estimate corrected for multiple sources of undercount bias that, if left uncorrected, would have underestimated the true population size by as much as 22.9%. Our comparison of these alternative methods demonstrates how various components of our method contribute to improving the final

  7. HYBRID EDUCATION: THE ESTIMATION IN THE CATEGORIES OF INFORMATION-AXIOLOGICAL APPROACH

    Directory of Open Access Journals (Sweden)

    A. S. Kizilova

    2018-01-01

    Full Text Available Introduction: a hybrid assessment of reality is a new information-axiological level of communication between people. The term "hybrid (hybrid training" has been used as a result of the integration of digital and communication technologies in the form of online courses.Materials and methods: the main Russian forms of education are analyzed. The evaluation of the forms of education in the categories of the information-axiological approach is made on the basis of the following idea: everything is interchangeable, since everything has value. The mixing principles and models used in the process of hybrid formation are considered. Due to the fact that any mixed training requires planning, the analysis of the project and the target group, content analysis and financial analysis in this process is carried out.Results: specific educational methods are studied at the Bauman MSTU, subject to a hybrid assessment in the categories of the information-axiological approach. The analysis showed that the above explanation of the term "hybrid formation" is extremely narrow and one-sided. In particular, the search for information on volunteer education and the search for a socially-based education was conducted not only in the Bauman MSTU, but in Russia as a whole. However, the result was the portals of international student organizations with their own projects. Another example of a different interpretation of the "hybrid education" may be the assumption of quite axiologically new duties.Discussion and Conclusions: hybrid education is not limited to any temporal and territorial framework. It can manifest itself not only in the Internet-sphere, but also in the most diverse spheres of everyday life, with the interaction of various people and entire societies.

  8. Spontaneous tension haemopneumothorax

    Directory of Open Access Journals (Sweden)

    Itam Sarah

    2008-10-01

    Full Text Available Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported. Aetiology and current approach to spontaneous haemothorax are discussed briefly.

  9. Air traffic surveillance and control using hybrid estimation and protocol-based conflict resolution

    Science.gov (United States)

    Hwang, Inseok

    The continued growth of air travel and recent advances in new technologies for navigation, surveillance, and communication have led to proposals by the Federal Aviation Administration (FAA) to provide reliable and efficient tools to aid Air Traffic Control (ATC) in performing their tasks. In this dissertation, we address four problems frequently encountered in air traffic surveillance and control; multiple target tracking and identity management, conflict detection, conflict resolution, and safety verification. We develop a set of algorithms and tools to aid ATC; These algorithms have the provable properties of safety, computational efficiency, and convergence. Firstly, we develop a multiple-maneuvering-target tracking and identity management algorithm which can keep track of maneuvering aircraft in noisy environments and of their identities. Secondly, we propose a hybrid probabilistic conflict detection algorithm between multiple aircraft which uses flight mode estimates as well as aircraft current state estimates. Our algorithm is based on hybrid models of aircraft, which incorporate both continuous dynamics and discrete mode switching. Thirdly, we develop an algorithm for multiple (greater than two) aircraft conflict avoidance that is based on a closed-form analytic solution and thus provides guarantees of safety. Finally, we consider the problem of safety verification of control laws for safety critical systems, with application to air traffic control systems. We approach safety verification through reachability analysis, which is a computationally expensive problem. We develop an over-approximate method for reachable set computation using polytopic approximation methods and dynamic optimization. These algorithms may be used either in a fully autonomous way, or as supporting tools to increase controllers' situational awareness and to reduce their work load.

  10. Initial tension loss in cerclage cables.

    Science.gov (United States)

    Ménard, Jérémie; Émard, Maxime; Canet, Fanny; Brailovski, Vladimir; Petit, Yvan; Laflamme, George Y

    2013-10-01

    Cerclage cables, frequently used in the management of fractures and osteotomies, are associated with a high failure rate and significant loosening during surgery. This study compared the capacity to maintain tension of different types of orthopaedic cable systems. Multifilament Cobalt-Chrome (CoCr) cables with four different crimp/clamp devices (DePuy, Stryker, Zimmer and Smith&Nephew) and one non-metallic Nylon (Ny) cable from Kinamed were instrumented with a load cell to measure tension during insertion. Significant tension loss was observed with crimping for all cables (Ptensioner led to an additional unexpected tension loss (CoCr-DePuy: 18%, CoCr-Stryker: 29%, CoCr-Smith&Nephew: 33%, Ny: 46%, and CoCr-Zimmer: 52%). The simple CoCr (DePuy) cable system outperformed the more sophisticated locking devices due to its significantly better ability to prevent tension loss. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Toward a general psychological model of tension and suspense.

    Science.gov (United States)

    Lehne, Moritz; Koelsch, Stefan

    2015-01-01

    Tension and suspense are powerful emotional experiences that occur in a wide variety of contexts (e.g., in music, film, literature, and everyday life). The omnipresence of tension and suspense suggests that they build on very basic cognitive and affective mechanisms. However, the psychological underpinnings of tension experiences remain largely unexplained, and tension and suspense are rarely discussed from a general, domain-independent perspective. In this paper, we argue that tension experiences in different contexts (e.g., musical tension or suspense in a movie) build on the same underlying psychological processes. We discuss key components of tension experiences and propose a domain-independent model of tension and suspense. According to this model, tension experiences originate from states of conflict, instability, dissonance, or uncertainty that trigger predictive processes directed at future events of emotional significance. We also discuss possible neural mechanisms underlying tension and suspense. The model provides a theoretical framework that can inform future empirical research on tension phenomena.

  12. Finite element modelling of concrete beams reinforced with hybrid fiber reinforced bars

    Science.gov (United States)

    Smring, Santa binti; Salleh, Norhafizah; Hamid, NoorAzlina Abdul; Majid, Masni A.

    2017-11-01

    Concrete is a heterogeneous composite material made up of cement, sand, coarse aggregate and water mixed in a desired proportion to obtain the required strength. Plain concrete does not with stand tension as compared to compression. In order to compensate this drawback steel reinforcement are provided in concrete. Now a day, for improving the properties of concrete and also to take up tension combination of steel and glass fibre-reinforced polymer (GFRP) bars promises favourable strength, serviceability, and durability. To verify its promise and support design concrete structures with hybrid type of reinforcement, this study have investigated the load-deflection behaviour of concrete beams reinforced with hybrid GFRP and steel bars by using ATENA software. Fourteen beams, including six control beams reinforced with only steel or only GFRP bars, were analysed. The ratio and the ordinate of GFRP to steel were the main parameters investigated. The behaviour of these beams was investigated via the load-deflection characteristics, cracking behaviour and mode of failure. Hybrid GFRP-Steel reinforced concrete beam showed the improvement in both ultimate capacity and deflection concomitant to the steel reinforced concrete beam. On the other hand, finite element (FE) modelling which is ATENA were validated with previous experiment and promising the good result to be used for further analyses and development in the field of present study.

  13. A numerical study on seismic response of self-centring precast segmental columns at different post-tensioning forces

    Directory of Open Access Journals (Sweden)

    Ehsan Nikbakht

    Full Text Available Precast bridge columns have shown increasing demand over the past few years due to the advantages of such columns when compared against conventional bridge columns, particularly due to the fact that precast bridge columns can be constructed off site and erected in a short period of time. The present study analytically investigates the behaviour of self-centring precast segmental bridge columns under nonlinear-static and pseudo-dynamic loading at different prestressing strand levels. Self-centring segmental columns are composed of prefabricated reinforced concrete segments which are connected by central post-tensioning (PT strands. The present study develops a three dimensional (3D nonlinear finite element model for hybrid post-tensioned precast segmental bridge columns. The model is subjected to constant axial loading and lateral reverse cyclic loading. The lateral force displacement results of the analysed columns show good agreement with the experimental response of the columns. Bonded post-tensioned segmental columns at 25%, 40% and 70% prestressing strand stress levels are analysed and compared with an emulative monolithic conventional column. The columns with a higher initial prestressing strand levels show greater initial stiffness and strength but show higher stiffness reduction at large drifts. In the time-history analysis, the column samples are subjected to different earthquake records to investigate the effect post-tensioning force levels on their lateral seismic response in low and higher seismicity zones. The results indicate that, for low seismicity zones, post-tensioned segmental columns with a higher initial stress level deflect lower lateral peak displacement. However, in higher seismicity zones, applying a high initial stress level should be avoided for precast segmental self-centring columns with low energy dissipation capacity.

  14. Tension type headaches: a review

    African Journals Online (AJOL)

    Location of the pain:There is often a typical location for tension- type headaches, as ... Cranial nerve abnormalities, including papilloedema. • Signs of ... peripheral and central mechanisms underlie tension-type ... Physiotherapy has been shown to be an effective management option for .... Acupuncture in primary headache.

  15. Post-tensioning system surveillance program

    International Nuclear Information System (INIS)

    Drew, G.E.

    1979-01-01

    Nuclear power plant containment structure post-tensioning system tendon surveillance program is described in detail. Data collected over three yearly post-tensioning system Surveillance Programs is presented and evaluated to correlate anticipated stress losses with actual losses. In addition corrosion protected system performance is analyzed

  16. The study and design of tension controller

    Science.gov (United States)

    Jun, G.; Lamei, X.

    2018-02-01

    Tension control is a wide used technology in areas such as textiles, paper and plastic films. In this article, the tension control system release and winding process is analyzed and the mathematical model of tension control system is established, and a high performance tension controller is designed. In hardware design, STM32F130 single chip microcomputer is used as the control core, which has the characteristics of fast running speed and rich peripheral features. In software design, μC/OS-II operating system is introduced to improve the efficiency of single chip microcomputer, and enhance the independence of each module, and make development and maintenance more convenient. The taper tension control is adopted in the winding part, which can effectively solve the problem of rolling shrinkage. The results show that the tension controller has the characteristics of simple structure, easy operation and stable performance.

  17. Tension and robustness in multitasking cellular networks.

    Directory of Open Access Journals (Sweden)

    Jeffrey V Wong

    Full Text Available Cellular networks multitask by exhibiting distinct, context-dependent dynamics. However, network states (parameters that generate a particular dynamic are often sub-optimal for others, defining a source of "tension" between them. Though multitasking is pervasive, it is not clear where tension arises, what consequences it has, and how it is resolved. We developed a generic computational framework to examine the source and consequences of tension between pairs of dynamics exhibited by the well-studied RB-E2F switch regulating cell cycle entry. We found that tension arose from task-dependent shifts in parameters associated with network modules. Although parameter sets common to distinct dynamics did exist, tension reduced both their accessibility and resilience to perturbation, indicating a trade-off between "one-size-fits-all" solutions and robustness. With high tension, robustness can be preserved by dynamic shifting of modules, enabling the network to toggle between tasks, and by increasing network complexity, in this case by gene duplication. We propose that tension is a general constraint on the architecture and operation of multitasking biological networks. To this end, our work provides a framework to quantify the extent of tension between any network dynamics and how it affects network robustness. Such analysis would suggest new ways to interfere with network elements to elucidate the design principles of cellular networks.

  18. Mentoring Preservice Teachers: Identifying Tensions and Possible Resolutions

    Science.gov (United States)

    Hudson, Peter; Hudson, Sue

    2018-01-01

    Tensions can occur in the mentor-mentee relationship during school-based professional experiences that require problem solving. What are the tensions for mentor teachers in preservice teacher education and how might these tensions be resolved? This qualitative study collected data from 31 high school mentor teachers about tensions experienced with…

  19. Multifaceted, cross-generational costs of hybridization in sibling Drosophila species.

    Directory of Open Access Journals (Sweden)

    Erin M Myers

    Full Text Available Maladaptive hybridization, as determined by the pattern and intensity of selection against hybrid individuals, is an important factor contributing to the evolution of prezygotic reproductive isolation. To identify the consequences of hybridization between Drosophila pseudoobscura and D. persimilis, we estimated multiple fitness components for F1 hybrids and backcross progeny and used these to compare the relative fitness of parental species and their hybrids across two generations. We document many sources of intrinsic (developmental and extrinsic (ecological selection that dramatically increase the fitness costs of hybridization beyond the well-documented F1 male sterility in this model system. Our results indicate that the cost of hybridization accrues over multiple generations and reinforcement in this system is driven by selection against hybridization above and beyond the cost of hybrid male sterility; we estimate a fitness loss of >95% relative to the parental species across two generations of hybridization. Our findings demonstrate the importance of estimating hybridization costs using multiple fitness measures from multiple generations in an ecologically relevant context; so doing can reveal intense postzygotic selection against hybridization and thus, an enhanced role for reinforcement in the evolution of populations and diversification of species.

  20. Multifaceted, cross-generational costs of hybridization in sibling Drosophila species.

    Science.gov (United States)

    Myers, Erin M; Harwell, Tiffany I; Yale, Elizabeth L; Lamb, Abigail M; Frankino, W Anthony

    2013-01-01

    Maladaptive hybridization, as determined by the pattern and intensity of selection against hybrid individuals, is an important factor contributing to the evolution of prezygotic reproductive isolation. To identify the consequences of hybridization between Drosophila pseudoobscura and D. persimilis, we estimated multiple fitness components for F1 hybrids and backcross progeny and used these to compare the relative fitness of parental species and their hybrids across two generations. We document many sources of intrinsic (developmental) and extrinsic (ecological) selection that dramatically increase the fitness costs of hybridization beyond the well-documented F1 male sterility in this model system. Our results indicate that the cost of hybridization accrues over multiple generations and reinforcement in this system is driven by selection against hybridization above and beyond the cost of hybrid male sterility; we estimate a fitness loss of >95% relative to the parental species across two generations of hybridization. Our findings demonstrate the importance of estimating hybridization costs using multiple fitness measures from multiple generations in an ecologically relevant context; so doing can reveal intense postzygotic selection against hybridization and thus, an enhanced role for reinforcement in the evolution of populations and diversification of species.

  1. Speed control for a two-mass drive system using integrated fuzzy estimator and hybrid fuzzy PD/PI controller

    International Nuclear Information System (INIS)

    Pai, N-S; Kuo, Y-P

    2008-01-01

    This paper presents a novel speed control scheme for a 2- mass motor drive system. The speed controller is based on the estimated state feedback compensation. The integrated fuzzy observer can give a fast and accuracy estimation of the unmeasured states. Two kinds of hybrid fuzzy proportional-derivative and proportional-integral (HF PD/PI) are proposed to cope with this speed control problem. The first is the static HF PD/PI controller and the second is the dynamic one. Simulation results show that the developed integrated fuzzy observer provide the better estimation performance than that of the Kalman filter and the proposed control schemes can effectively track the desired speed in the presence of load disturbance

  2. Viscosity and surface tension of binary systems of N,N-dimethylformamide with alkan-1-ols at different temperatures

    International Nuclear Information System (INIS)

    Mohammad, Abubaker A.; Alkhaldi, Khaled H.A.E.; AlTuwaim, Mohammad S.; Al-Jimaz, Adel S.

    2013-01-01

    Highlights: ► Physical properties of binary mixtures of DMF+1-pentanol, 1-hexanol, or 1-heptanol. ► Viscosity and surface tension were measured. ►Δη, Δσ σ and G ∗E were calculated using the experimental data. ► H σ and S σ were determined using the surface tension data. ► Semi-empirical relations were used to estimate the viscosity of liquid mixtures. - Abstract: Viscosity η and surface tension σ were measured for binary mixtures of N,N-dimethylformamide DMF with pentan-1-ol, hexan-1-ol, and heptan-1-ol at T = (298.15, 303.15, 308.15, and 313.15) K and atmospheric pressure over the entire mole fraction range. Deviations in viscosity Δη and surface tension Δσ were calculated using experimental results. Moreover, the values of the excess Gibbs free energy of activation G ∗E , surface enthalpy H σ and surface entropy S σ of these mixtures were determined. Viscosity measurements of the binary systems were correlated with Grunberg and Nissan, the three-body and four-body McAllister expressions. Viscosity deviation, surface tension deviation and excess Gibbs energy of activation functions were fitted to the method of Redlich–Kister (R–K) polynomial to estimate the coefficients and standard deviations. The effects of chain length of alkan-1-ols and temperature on the thermodynamic properties of binary systems were studied.

  3. Sequence-dependent theory of oligonucleotide hybridization kinetics

    International Nuclear Information System (INIS)

    Marimuthu, Karthikeyan; Chakrabarti, Raj

    2014-01-01

    A theoretical approach to the prediction of the sequence and temperature-dependent rate constants for oligonucleotide hybridization reactions has been developed based on the theory of relaxation kinetics. One-sided and two-sided melting reaction mechanisms for oligonucleotide hybridization reactions have been considered, analyzed, modified, and compared to select a physically consistent as well as robust model for prediction of the relaxation times of DNA hybridization reactions that agrees with the experimental evidence. The temperature- and sequence-dependent parameters of the proposed model have been estimated using available experimental data. The relaxation time model that we developed has been combined with the nearest neighbor model of hybridization thermodynamics to estimate the temperature- and sequence-dependent rate constants of an oligonucleotide hybridization reaction. The model-predicted rate constants are compared to experimentally determined rate constants for the same oligonucleotide hybridization reactions. Finally, we consider a few important applications of kinetically controlled DNA hybridization reactions

  4. Perceiving the affordance of string tension for power strokes in badminton: expertise allows effective use of all string tensions.

    Science.gov (United States)

    Zhu, Qin

    2013-01-01

    Affordances mean opportunities for action. These affordances are important for sports performance and relevant to the abilities developed by skilled athletes. In racquet sports such as badminton, different players prefer widely different string tension because it is believed to provide opportunities for effective strokes. The current study examined whether badminton players can perceive the affordance of string tension for power strokes and whether the perception of affordance itself changed as a function of skill level. The results showed that string tension constrained the striking performance of both novice and recreational players, but not of expert players. When perceptual capability was assessed, perceptual mode did not affect perception of the optimal string tension. Skilled players successfully perceived the affordance of string tension, but only experts were concerned about saving energy. Our findings demonstrated that perception of the affordance of string tension in badminton was determined by action abilities. Furthermore, experts could adjust the action to maintain a superior level of performance based on the perception of affordance.

  5. Tension waves in tethered satellite cables

    Science.gov (United States)

    Lallman, F. J.

    1984-01-01

    A one-degree-of-freedom simulation of the Tethered Satellite System (TSS) was programmed using a distributed system model of the tether based on the one-dimensional wave equation. This model represents the time varying tension profile along the tether as the sum of two traveling waves of tension moving in opposite directions. A control loop was devised which combines a deployment rate command with the measured tension at the deployer to produce a smooth, stable rate of deployment of the subsatellite. Simulation results show a buildup of periodic bursts of high frequency oscillation in tension. This report covers the mathematical modelling and simulation results and explains the reason for the observed oscillations. The design of a possible vibration damping device is discussed.

  6. Hybrid external fixation of the proximal tibia: strategies to improve frame stability.

    Science.gov (United States)

    Roberts, Craig S; Dodds, James C; Perry, Kelvin; Beck, Dennis; Seligson, David; Voor, Michael J

    2003-07-01

    To determine the specific frame construction strategies that can increase the stability of hybrid (ring with tensioned wires proximally connected by bars to half-pins distally) external fixation of proximal tibia fractures. DESIGN Repeated measures biomechanical testing. Laboratory. Composite fiberglass tibias. Using the Heidelberg and Ilizarov systems, external fixators were tested on composite fiberglass tibias with a 1-cm proximal osteotomy (OTA fracture classification 41-A3.3) in seven frame configurations: unilateral frames with 5-mm diameter half-pins and 6-mm diameter half-pins; hybrid (as described above), with and without a 6-mm anterior proximal half-pin; a "box" hybrid (additional ring group distal to the fracture connected by symmetrically spaced bars to the proximal rings) with and without an anterior, proximal half-pin; and a full, four-ring configuration. Each configuration was loaded in four positions (central, medial, posterior, and posteromedial). Displacement at point of loading of proximal fragment. The "box" hybrid was stiffer than the standard hybrid for all loading positions. The addition of an anterior half-pin stiffened the standard hybrid and the "box" hybrid. The most dramatic improvements in the stability of hybrid frames used for proximal tibial fractures result from addition of an anterior, proximal half-pin.

  7. Some factors affecting the use of lighter than air systems. [economic and performance estimates for dirigibles and semi-buoyant hybrid vehicles

    Science.gov (United States)

    Havill, C. D.

    1974-01-01

    The uses of lighter-than-air vehicles are examined in the present day transportation environment. Conventional dirigibles were found to indicate an undesirable economic risk due to their low speeds and to uncertainties concerning their operational use. Semi-buoyant hybrid vehicles are suggested as an alternative which does not have many of the inferior characteristics of conventional dirigibles. Economic and performance estimates for hybrid vehicles indicate that they are competitive with other transportation systems in many applications, and unique in their ability to perform some highly desirable emergency missions.

  8. An adaptive finite element method for simulating surface tension with the gradient theory of fluid interfaces

    KAUST Repository

    Kou, Jisheng; Sun, Shuyu

    2014-01-01

    The gradient theory for the surface tension of simple fluids and mixtures is rigorously analyzed based on mathematical theory. The finite element approximation of surface tension is developed and analyzed, and moreover, an adaptive finite element method based on a physical-based estimator is proposed and it can be coupled efficiently with Newton's method as well. The numerical tests are carried out both to verify the proposed theory and to demonstrate the efficiency of the proposed method. © 2013 Elsevier B.V. All rights reserved.

  9. An adaptive finite element method for simulating surface tension with the gradient theory of fluid interfaces

    KAUST Repository

    Kou, Jisheng

    2014-01-01

    The gradient theory for the surface tension of simple fluids and mixtures is rigorously analyzed based on mathematical theory. The finite element approximation of surface tension is developed and analyzed, and moreover, an adaptive finite element method based on a physical-based estimator is proposed and it can be coupled efficiently with Newton\\'s method as well. The numerical tests are carried out both to verify the proposed theory and to demonstrate the efficiency of the proposed method. © 2013 Elsevier B.V. All rights reserved.

  10. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.......To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  11. Evaluation of the clamping force in high tension bolt by using the ultrasonic nonlinearity

    International Nuclear Information System (INIS)

    Jang, Kyung Young; Cheon, Hae Wha; Ha, Hob; Park, Man Sick; Kim, No You

    2005-01-01

    High tension bolts have been used widely for the clamping of many kinds of large structure. Therefore, its estimation has been regarded as main issue in the maintenance of high tension bolts. This paper proposes a novel method using the ultrasonic nonlinearity, which is based on the dependency of sound speed on the stress. For this we introduce nonlinear elastic constants in the stress-strain relationship, and derive the sound speed as a linear function of stress. In order to verify the usefulness of the proposed method, two kinds of experiments are carried out: The first one is to measure the sound speed when the bolt is stressed by the tension tester. The result showed good agreement with the expected linear relationship between the sound speed and the axial stress. The second one is to measure the sound speed when the bolt is stressed by the torque wrench. The results showed that the sound speed was decreased when the torque was increased. From these results we can say that the proposed method is enough useful to evaluate the clamping force in the high tension bolt.

  12. Distributed and self-adaptive vehicle speed estimation in the composite braking case for four-wheel drive hybrid electric car

    Science.gov (United States)

    Zhao, Z.-G.; Zhou, L.-J.; Zhang, J.-T.; Zhu, Q.; Hedrick, J.-K.

    2017-05-01

    Considering the controllability and observability of the braking torques of the hub motor, Integrated Starter Generator (ISG), and hydraulic brake for four-wheel drive (4WD) hybrid electric cars, a distributed and self-adaptive vehicle speed estimation algorithm for different braking situations has been proposed by fully utilising the Electronic Stability Program (ESP) sensor signals and multiple powersource signals. Firstly, the simulation platform of a 4WD hybrid electric car was established, which integrates an electronic-hydraulic composited braking system model and its control strategy, a nonlinear seven degrees-of-freedom vehicle dynamics model, and the Burckhardt tyre model. Secondly, combining the braking torque signals with the ESP signals, self-adaptive unscented Kalman sub-filter and main-filter adaptable to the observation noise were, respectively, designed. Thirdly, the fusion rules for the sub-filters and master filter were proposed herein, and the estimation results were compared with the simulated value of a real vehicle speed. Finally, based on the hardware in-the-loop platform and by picking up the regenerative motor torque signals and wheel cylinder pressure signals, the proposed speed estimation algorithm was tested under the case of moderate braking on the highly adhesive road, and the case of Antilock Braking System (ABS) action on the slippery road, as well as the case of ABS action on the icy road. Test results show that the presented vehicle speed estimation algorithm has not only a high precision but also a strong adaptability in the composite braking case.

  13. Urinary incontinence - tension-free vaginal tape

    Science.gov (United States)

    ... ency/article/007377.htm Urinary incontinence - tension-free vaginal tape To use the sharing features on this page, please enable JavaScript. Placement of tension-free vaginal tape is surgery to help control stress urinary ...

  14. Evaluation of post-tensioning of a curved continuous girder using long-gauge fiber optic sensors

    Science.gov (United States)

    Abdel-Jaber, Hiba; Glisic, Branko

    2014-03-01

    Streicker Bridge is a pedestrian bridge on the Princeton University campus. It consists of a main span and four curved continuous girders (legs). The main span and the southeast leg of the bridge are equipped with fiber optic strain and temperature sensors, allowing the bridge to also function as an on-campus laboratory for the Structural Health Monitoring research group. Parallel sensors were embedded at critical cross-sections in the deck prior to the pouring of concrete. The deck of the southeast leg experienced early age cracking within a few days of concrete pouring, which was detected by the strain sensors. Post-tensioning was then performed and it is assumed that it closed off the cracks. Evaluation of post-tensioning forces is complex due to the existence of the cracks, and this paper researches a procedure to estimate the post-tensioning forces at cracked and uncracked locations. The obtained post-tensioning forces were compared to design forces and conclusions regarding the status of post-tensioning were made. This is important as it gives information on the actual health condition and performance of the structure. It also provides information on the safety of the structure. The objective of this paper is to present a methodology for the evaluation of the post-tensioning force along the deck based on strain measurements. The monitoring system, results, data analysis method, and conclusions regarding the bridge health condition and performance are presented in this paper.

  15. Damage development in woven fabric composites during tension-tension fatigue

    DEFF Research Database (Denmark)

    Hansen, U.

    1999-01-01

    of the operating fatigue damage mechanism(s). Fatigue leads to a degradation of material properties. Consequently, in connection with impact induced local stress raisers, fatigue produces continuously changing non-uniform stress fields because of stress redistribution effects. Other models addressing evolution...... of fatigue damage in composite materials have not been able to simulate evolving nonuniform stress fields. Therefore. in the second part of this paper, an analytical/numerical approach capable of addressing these issues is also proposed.......Impacted woven fabric composites were tested in tension-tension fatigue. In contrast to results from static testing, the effects of low energy impact damage in a fatigue environment were found to be the critical element leading to failure of the specimen. This difference emphasizes the need...

  16. A Novel Degradation Estimation Method for a Hybrid Energy Storage System Consisting of Battery and Double-Layer Capacitor

    Directory of Open Access Journals (Sweden)

    Yuanbin Yu

    2016-01-01

    Full Text Available This paper presents a new method for battery degradation estimation using a power-energy (PE function in a battery/ultracapacitor hybrid energy storage system (HESS, and the integrated optimization which concerns both parameters matching and control for HESS has been done as well. A semiactive topology of HESS with double-layer capacitor (EDLC coupled directly with DC-link is adopted for a hybrid electric city bus (HECB. In the purpose of presenting the quantitative relationship between system parameters and battery serving life, the data during a 37-minute driving cycle has been collected and decomposed into discharging/charging fragments firstly, and then the optimal control strategy which is supposed to maximally use the available EDLC energy is presented to decompose the power between battery and EDLC. Furthermore, based on a battery degradation model, the conversion of power demand by PE function and PE matrix is applied to evaluate the relationship between the available energy stored in HESS and the serving life of battery pack. Therefore, according to the approach which could decouple parameters matching and optimal control of the HESS, the process of battery degradation and its serving life estimation for HESS has been summed up.

  17. Speaker and Observer Perceptions of Physical Tension during Stuttering.

    Science.gov (United States)

    Tichenor, Seth; Leslie, Paula; Shaiman, Susan; Yaruss, J Scott

    2017-01-01

    Speech-language pathologists routinely assess physical tension during evaluation of those who stutter. If speakers experience tension that is not visible to clinicians, then judgments of severity may be inaccurate. This study addressed this potential discrepancy by comparing judgments of tension by people who stutter and expert clinicians to determine if clinicians could accurately identify the speakers' experience of physical tension. Ten adults who stutter were audio-video recorded in two speaking samples. Two board-certified specialists in fluency evaluated the samples using the Stuttering Severity Instrument-4 and a checklist adapted for this study. Speakers rated their tension using the same forms, and then discussed their experiences in a qualitative interview so that themes related to physical tension could be identified. The degree of tension reported by speakers was higher than that observed by specialists. Tension in parts of the body that were less visible to the observer (chest, abdomen, throat) was reported more by speakers than by specialists. The thematic analysis revealed that speakers' experience of tension changes over time and that these changes may be related to speakers' acceptance of stuttering. The lack of agreement between speaker and specialist perceptions of tension suggests that using self-reports is a necessary component for supporting the accurate diagnosis of tension in stuttering. © 2018 S. Karger AG, Basel.

  18. The tension of framed membranes from computer simulations

    DEFF Research Database (Denmark)

    Hamkens, Daniel; Jeppesen, Claus; Ipsen, John H.

    2018-01-01

    the membranes display power-law characteristics for the equation of state, while higher tension levels includes both an extended linear (elastic) as well as a highly non-linear stretching regime. For semi-flexible membranes a transition from extended to buckled conformations takes place at negative frame......Abstract.: We have analyzed the behavior of a randomly triangulated, self-avoiding surface model of a flexible, fluid membrane subject to a circular boundary by Wang-Landau Monte Carlo computer simulation techniques. The dependence of the canonical free energy and frame tension on the frame area...... is obtained for flexible membranes. It is shown that for low bending rigidities the framed membrane is only stable above a threshold tension, suggesting a discontinuous transition from the collapsed (branched polymer) state to a finite tension extended state. In a tension range above this threshold tension...

  19. Assessment and reduction of diaphragmatic tension during hiatal hernia repair.

    Science.gov (United States)

    Bradley, Daniel Davila; Louie, Brian E; Farivar, Alexander S; Wilshire, Candice L; Baik, Peter U; Aye, Ralph W

    2015-04-01

    During hiatal hernia repair there are two vectors of tension: axial and radial. An optimal repair minimizes the tension along these vectors. Radial tension is not easily recognized. There are no simple maneuvers like measuring length that facilitate assessment of radial tension. The aims of this project were to: (1) establish a simple intraoperative method to evaluate baseline tension of the diaphragmatic hiatal muscle closure; and, (2) assess if tension is reduced by relaxing maneuvers and if so, to what degree. Diaphragmatic characteristics and tension were assessed during hiatal hernia repair with a tension gage. We compared tension measured after hiatal dissection and after relaxing maneuvers were performed. Sixty-four patients (29 M:35F) underwent laparoscopic hiatal hernia repair. Baseline hiatal width was 2.84 cm and tension 13.6 dag. There was a positive correlation between hiatal width and tension (r = 0.55) but the strength of association was low (r (2) = 0.31). Four different hiatal shapes (slit, teardrop, "D", and oval) were identified and appear to influence tension and the need for relaxing incision. Tension was reduced by 35.8 % after a left pleurotomy (12 patients); by 46.2 % after a right crural relaxing incision (15 patients); and by 56.1 % if both maneuvers were performed (6 patients). Tension on the diaphragmatic hiatus can be measured with a novel device. There was a limited correlation with width of the hiatal opening. Relaxing maneuvers such as a left pleurotomy or a right crural relaxing incision reduced tension. Longer term follow-up will determine whether outcomes are improved by quantifying and reducing radial tension.

  20. Density and surface tension of ionic liquids.

    Science.gov (United States)

    Kolbeck, C; Lehmann, J; Lovelock, K R J; Cremer, T; Paape, N; Wasserscheid, P; Fröba, A P; Maier, F; Steinrück, H-P

    2010-12-30

    We measured the density and surface tension of 9 bis[(trifluoromethyl)sulfonyl]imide ([Tf(2)N](-))-based and 12 1-methyl-3-octylimidazolium ([C(8)C(1)Im](+))-based ionic liquids (ILs) with the vibrating tube and the pendant drop method, respectively. This comprehensive set of ILs was chosen to probe the influence of the cations and anions on density and surface tension. When the alkyl chain length in the [C(n)C(1)Im][Tf(2)N] series (n = 1, 2, 4, 6, 8, 10, 12) is increased, a decrease in density is observed. The surface tension initially also decreases but reaches a plateau for alkyl chain lengths greater than n = 8. Functionalizing the alkyl chains with ethylene glycol groups results in a higher density as well as a higher surface tension. For the dependence of density and surface tension on the chemical nature of the anion, relations are only found for subgroups of the studied ILs. Density and surface tension values are discussed with respect to intermolecular interactions and surface composition as determined by angle-resolved X-ray photoelectron spectroscopy (ARXPS). The absence of nonvolatile surface-active contaminants was proven by ARXPS.

  1. Hemodynamic parameters change earlier than tissue oxygen tension in hemorrhage.

    Science.gov (United States)

    Pestel, Gunther J; Fukui, Kimiko; Kimberger, Oliver; Hager, Helmut; Kurz, Andrea; Hiltebrand, Luzius B

    2010-05-15

    Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds. Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after preparation, baseline measurements were taken. At first, 5% of total blood volume was withdrawn, followed by another 5% increment, and then in 10% increments until death. After withdrawal of 5% of estimated blood volume, dPP increased from 6.1% +/- 3.0% to 20.8% +/- 2.7% (P < 0.01). Mean arterial pressure (MAP), mean pulmonary artery pressure (PAP) and pulmonary artery occlusion pressure (PAOP) decreased with a blood loss of 10% (P < 0.01). Cardiac output (CO) changed after a blood loss of 20% (P < 0.05). Tissue oxygen tension in central organs, and blood flow in the jejunal muscularis decreased (P < 0.05) after a blood loss of 20%. Tissue oxygen tension in the skin, and jejunal mucosa blood flow decreased (P < 0.05) after a blood loss of 40% and 50%, respectively. In this hemorrhagic pig model systemic hemodynamic parameters were more sensitive to detect acute hypovolemia than tissue oxygen tension measurements or jejunal LDF measurements. Acute blood loss was detected first by dPP. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  2. An Unscented Kalman-Particle Hybrid Filter for Space Object Tracking

    Science.gov (United States)

    Raihan A. V, Dilshad; Chakravorty, Suman

    2018-03-01

    Optimal and consistent estimation of the state of space objects is pivotal to surveillance and tracking applications. However, probabilistic estimation of space objects is made difficult by the non-Gaussianity and nonlinearity associated with orbital mechanics. In this paper, we present an unscented Kalman-particle hybrid filtering framework for recursive Bayesian estimation of space objects. The hybrid filtering scheme is designed to provide accurate and consistent estimates when measurements are sparse without incurring a large computational cost. It employs an unscented Kalman filter (UKF) for estimation when measurements are available. When the target is outside the field of view (FOV) of the sensor, it updates the state probability density function (PDF) via a sequential Monte Carlo method. The hybrid filter addresses the problem of particle depletion through a suitably designed filter transition scheme. To assess the performance of the hybrid filtering approach, we consider two test cases of space objects that are assumed to undergo full three dimensional orbital motion under the effects of J 2 and atmospheric drag perturbations. It is demonstrated that the hybrid filters can furnish fast, accurate and consistent estimates outperforming standard UKF and particle filter (PF) implementations.

  3. Relationship between surface tension and refractive index in binary non-electrolyte mixtures

    International Nuclear Information System (INIS)

    Acevedo, I.L.; Pedrosa, G.C.; Katz, M.

    1990-01-01

    Lorentz-Lorenz equation for molecular refraction has been combined with Sugden's parachor equation for binary non-electrolyte mixtures at 298.15 K. The obtained equation has been shown successful in calculating values of surface tensions, by measuring refractive indices of the binary mixtures at the same mole fractions. The estimated error decreases when the mixtures present possible isorefractives. (Author) [es

  4. Traumatic tension pneumocephalus: Two case reports

    Directory of Open Access Journals (Sweden)

    Abubaker Al-Aieb

    2017-01-01

    Conclusions: These are two rare cases with posttraumatic tension pneumocephalus treated conservatively with a favorable outcome. Early diagnosis of tension pneumocephalus is a crucial step to facilitate early recovery; however, the associated injuries need attention as they could influence the hospital course.

  5. Exploratory experimental investigations on post-tensioned structural glass beams

    DEFF Research Database (Denmark)

    Louter, C.; Nielsen, Jens Henrik; Belis, J.

    2013-01-01

    This paper discusses two projects on post-tensioned glass beams, performed at EPFL and DTU, respectively. In these projects small scale glass beams (length of 1.5m and 1m) are post-tensioned by means of steel threaded rods tensioned at the beam ends. The purpose of post-tensioning glass beams...

  6. The environment strongly affects estimates of heterosis in hybrid sweet sorghum

    Science.gov (United States)

    Sweet sorghum (Sorghum bicolor (L.) Moench) has potential as a biofuel feedstock but hybrid cultivars are needed to support an industry based on this crop. The purpose of this study was to compare five inbred sweet sorghum lines and 15 hybrids derived from them, and to determine the extent of envir...

  7. Critical review of on-board capacity estimation techniques for lithium-ion batteries in electric and hybrid electric vehicles

    Science.gov (United States)

    Farmann, Alexander; Waag, Wladislaw; Marongiu, Andrea; Sauer, Dirk Uwe

    2015-05-01

    This work provides an overview of available methods and algorithms for on-board capacity estimation of lithium-ion batteries. An accurate state estimation for battery management systems in electric vehicles and hybrid electric vehicles is becoming more essential due to the increasing attention paid to safety and lifetime issues. Different approaches for the estimation of State-of-Charge, State-of-Health and State-of-Function are discussed and analyzed by many authors and researchers in the past. On-board estimation of capacity in large lithium-ion battery packs is definitely one of the most crucial challenges of battery monitoring in the aforementioned vehicles. This is mostly due to high dynamic operation and conditions far from those used in laboratory environments as well as the large variation in aging behavior of each cell in the battery pack. Accurate capacity estimation allows an accurate driving range prediction and accurate calculation of a battery's maximum energy storage capability in a vehicle. At the same time it acts as an indicator for battery State-of-Health and Remaining Useful Lifetime estimation.

  8. Projective and hybrid projective synchronization for the Lorenz-Stenflo system with estimation of unknown parameters

    International Nuclear Information System (INIS)

    Mukherjee, Payel; Banerjee, Santo

    2010-01-01

    In this work, in the first phase, we study the phenomenon of projective synchronization in the Lorenz-Stenflo system. Synchronization is then investigated for the same system with unknown parameters. We show analytically that synchronization is possible for some proper choice of the nonlinear controller by using a suitable Lyapunov function. With the help of this result, it is also possible to estimate the values of the unknown system parameters. In the second phase as an extension of our analysis, we investigate the new hybrid projective synchronization for the same system. All our analyses are well supported with numerical evidence.

  9. Estimation of Heterosis and Combining Ability in F1 Hybrids of Upland Cotton for Yield and Fiber Traits

    International Nuclear Information System (INIS)

    Arain, B.T.; Baloch, M.J.; Bughio, Q.U.A.; Sial, P.; Arain, M.A.; Baloch, A.

    2015-01-01

    The experimental research was conducted so as to determine the general combining ability (GCA) and specific combining ability (SCA) estimates and heterotic effects for seed cotton yield and fibre traits in 5 x 5 half diallel crosses of upland cotton (Gossypium hirsutum L.). The parental genotypes studied were; CRIS-134, IR-3701, IR-1524, FH-113 and MG-6. The characters such as bolls/plant, sympodial branches/plant, boll weight (g), plant height (cm), fibre length (mm), seed cotton yield/plant (g), seed index (g) and ginning out turn percentage were studied. The experiment was laid-out in a randomized complete block design with four replications at experimental field of the Department of Plant Breeding and Genetics, Sindh Agriculture University Tandojam, Pakistan during 2013. The results revealed that, parents and hybrids differed significantly for their mean performance regarding all the traits studied. The importance of heterotic effects was evident from the significance of parents vs. hybrids performance. The variances due to GCA and SCA were significant for all the traits except that GCA was non-significant for boll weight only whereas, SCA was non-significant for boll weight, seed index and ginning out turn percentage. The significance of GCA indicated the importance of additive genes advocating the traits while, the involvement of non-additive genes was evident from the significance of SCA variances. The GCA variances were greater than SCA for bolls per plant, plant height, seed cotton yield and lint percentage while, SCA variances were higher than GCA for sympodial branches/plant and fibre length. Parents IR-3701, FH-113 and MG-6 displayed higher positive GCA effects for bolls/plant, sympodial branches/plant, fibre length, seed cotton yield, seed index and ginning out turn percentage. The per se performance of these three parents was exactly reflected in their GCA effects and such happenings are exceptional. Such results suggested that, all three parents were

  10. Tension pneumothorax, is it a really life-threatening condition?

    Science.gov (United States)

    2013-01-01

    Background Tension pneumothorax is a life-threatening occurrence that is infrequently the consequence of spontaneous pneumothorax. The aim of this study was to identify the risk factors for the development of tension pneumothorax and its effect on clinical outcomes. Methods We reviewed patients who were admitted with spontaneous pneumothorax between August 1, 2003 and December 31, 2011. Electronic medical records and the radiological findings were reviewed with chest x-ray and high-resolution computed tomography scans that were retrieved from the Picture Archiving Communication System. Results Out of the 370 patients included in this study, tension pneumothorax developed in 60 (16.2%). The bullae were larger in patients with tension pneumothorax than in those without (23.8 ± 16.2 mm vs 16.1 ± 19.1 mm; P = 0.007). In addition, the incidence of tension pneumothorax increased with the lung bulla size. Fibrotic adhesion was more prevalent in the tension pneumothorax group than in that without (P = 0.000). The bullae were large in patients with fibrotic adhesion than in those without adhesion (35.0 ± 22.3 mm vs 10.4 ± 11.5 mm; P = 0.000). On multivariate analysis, the size of bullae (odds ratio (OR) = 1.03, P = 0.001) and fibrotic adhesion (OR = 10.76, P = 0.000) were risk factors of tension pneumothorax. Hospital mortality was 3.3% in the tension pneumothorax group and it was not significantly different from those patients without tension pneunothorax (P = 0.252). Conclusions Tension pneumothorax is not uncommon, but clinically fatal tension pneumothorax is extremely rare. The size of the lung bullae and fibrotic adhesion contributes to the development of tension pneumothorax. PMID:24128176

  11. Elastic MCF Rubber with Photovoltaics and Sensing on Hybrid Skin (H-Skin) for Artificial Skin by Utilizing Natural Rubber: 2nd Report on the Effect of Tension and Compression on the Hybrid Photo- and Piezo-Electricity Properties in Wet-Type Solar Cell Rubber.

    Science.gov (United States)

    Shimada, Kunio

    2018-06-06

    In contrast to ordinary solid-state solar cells, a flexible, elastic, extensible and light-weight solar cell has the potential to be extremely useful in many new engineering applications, such as in the field of robotics. Therefore, we propose a new type of artificial skin for humanoid robots with hybrid functions, which we have termed hybrid skin (H-Skin). To realize the fabrication of such a solar cell, we have continued to utilize the principles of ordinary solid-state wet-type or dye-sensitized solar rubber as a follow-up study to the first report. In the first report, we dealt with both photovoltaic- and piezo-effects for dry-type magnetic compound fluid (MCF) rubber solar cells, which were generated because the polyisoprene, oleic acid of the magnetic fluid (MF), and water served as p- and n- semiconductors. In the present report, we deal with wet-type MCF rubber solar cells by using sensitized dyes and electrolytes. Photoreactions generated through the synthesis of these components were investigated by an experiment using irradiation with visible and ultraviolet light. In addition, magnetic clusters were formed by the aggregation of Fe₃O₄ in the MF and the metal particles created the hetero-junction structure of the semiconductors. In the MCF rubber solar cell, both photo- and piezo-electricity were generated using a physical model. The effects of tension and compression on their electrical properties were evaluated. Finally, we experimentally demonstrated the effect of the distance between the electrodes of the solar cell on photoelectricity and built-in electricity.

  12. Oxygen tension level and human viral infections

    Energy Technology Data Exchange (ETDEWEB)

    Morinet, Frédéric, E-mail: frederic.morinet@sls.aphp.fr [Centre des Innovations Thérapeutiques en Oncologie et Hématologie (CITOH), CHU Saint-Louis, Paris (France); Université Denis Diderot, Sorbonne Paris Cité Paris, Paris (France); Casetti, Luana [Institut Cochin INSERM U1016, Paris (France); François, Jean-Hugues; Capron, Claude [Institut Cochin INSERM U1016, Paris (France); Laboratoire d' Hématologie, Hôpital Ambroise Paré, Boulogne (France); Université de Versailles Saint-Quentin en Yvelynes, Versailles (France); Pillet, Sylvie [Laboratoire de Bactériologie-Virologie-Hygiène, CHU de Saint-Etienne, Saint-Etienne (France); Université de Lyon et Université de Saint-Etienne, Jean Monnet, GIMAP EA3064, F-42023 Saint-Etienne, Lyon (France)

    2013-09-15

    The role of oxygen tension level is a well-known phenomenon that has been studied in oncology and radiotherapy since about 60 years. Oxygen tension may inhibit or stimulate propagation of viruses in vitro as well as in vivo. In turn modulating oxygen metabolism may constitute a novel approach to treat viral infections as an adjuvant therapy. The major transcription factor which regulates oxygen tension level is hypoxia-inducible factor-1 alpha (HIF-1α). Down-regulating the expression of HIF-1α is a possible method in the treatment of chronic viral infection such as human immunodeficiency virus infection, chronic hepatitis B and C viral infections and Kaposi sarcoma in addition to classic chemotherapy. The aim of this review is to supply an updating concerning the influence of oxygen tension level in human viral infections and to evoke possible new therapeutic strategies regarding this environmental condition. - Highlights: • Oxygen tension level regulates viral replication in vitro and possibly in vivo. • Hypoxia-inducible factor 1 (HIF-1α) is the principal factor involved in Oxygen tension level. • HIF-1α upregulates gene expression for example of HIV, JC and Kaposi sarcoma viruses. • In addition to classical chemotherapy inhibition of HIF-1α may constitute a new track to treat human viral infections.

  13. Photometric redshifts for the next generation of deep radio continuum surveys - II. Gaussian processes and hybrid estimates

    Science.gov (United States)

    Duncan, Kenneth J.; Jarvis, Matt J.; Brown, Michael J. I.; Röttgering, Huub J. A.

    2018-04-01

    Building on the first paper in this series (Duncan et al. 2018), we present a study investigating the performance of Gaussian process photometric redshift (photo-z) estimates for galaxies and active galactic nuclei detected in deep radio continuum surveys. A Gaussian process redshift code is used to produce photo-z estimates targeting specific subsets of both the AGN population - infrared, X-ray and optically selected AGN - and the general galaxy population. The new estimates for the AGN population are found to perform significantly better at z > 1 than the template-based photo-z estimates presented in our previous study. Our new photo-z estimates are then combined with template estimates through hierarchical Bayesian combination to produce a hybrid consensus estimate that outperforms both of the individual methods across all source types. Photo-z estimates for radio sources that are X-ray sources or optical/IR AGN are significantly improved in comparison to previous template-only estimates - with outlier fractions and robust scatter reduced by up to a factor of ˜4. The ability of our method to combine the strengths of the two input photo-z techniques and the large improvements we observe illustrate its potential for enabling future exploitation of deep radio continuum surveys for both the study of galaxy and black hole co-evolution and for cosmological studies.

  14. Application of the Eötvos and Guggenheim empirical rules for predicting the density and surface tension of ionic liquids analogues

    Energy Technology Data Exchange (ETDEWEB)

    Mjalli, Farouq S., E-mail: farouqsm@yahoo.com [Petroleum and Chemical Engineering Department, Sultan Qaboos University, 123 Sultanate of Oman (Oman); Vakili-Nezhaad, Gholamreza; Shahbaz, Kaveh [School of Engineering, Taylor' s University, 47500 Selangor (Malaysia); AlNashef, Inas M. [Chemical Engineering Department, King Saud University, Riyadh 11421 (Saudi Arabia)

    2014-01-10

    Highlights: • Critical temperatures of eight common DES were calculated using two methods. • Density and surface tension were calculated using the Rackett and Guggenheim equations. • The Rackett method should be used in the low temperature range only. • The Eötvos and Guggenheim methods gave best density and surface tension predictions. - Abstract: The recent continuing interest in deep eutectic solvents (DES) as ionic liquids analogues and their successful applications in different areas of separation necessities the existence of reliable physical and thermodynamic properties database. The scarcity of data on the physical properties of such solvents, increases the need for their prediction using reliable methods. In this study, first the critical temperatures of eight DES systems have been calculated based on the Eötvos empirical equation using the experimental data of the density and surface tension at various temperatures, then the density and surface tension values of these systems were predicted from the calculated critical temperatures. For the density prediction the Eötvos and Guggenheim equations were combined to introduce a simple power law equation using the estimated critical temperatures from the Eötvos and the Modified Lydersen–Joback–Reid group contribution methods. Finally, the estimated critical temperatures by these two methods were used in the Guggenheim empirical equation to calculate the surface tension of the DES systems. The prediction quality of the two physical properties under investigation were compared and proper recommendations were postulated.

  15. Application of the Eötvos and Guggenheim empirical rules for predicting the density and surface tension of ionic liquids analogues

    International Nuclear Information System (INIS)

    Mjalli, Farouq S.; Vakili-Nezhaad, Gholamreza; Shahbaz, Kaveh; AlNashef, Inas M.

    2014-01-01

    Highlights: • Critical temperatures of eight common DES were calculated using two methods. • Density and surface tension were calculated using the Rackett and Guggenheim equations. • The Rackett method should be used in the low temperature range only. • The Eötvos and Guggenheim methods gave best density and surface tension predictions. - Abstract: The recent continuing interest in deep eutectic solvents (DES) as ionic liquids analogues and their successful applications in different areas of separation necessities the existence of reliable physical and thermodynamic properties database. The scarcity of data on the physical properties of such solvents, increases the need for their prediction using reliable methods. In this study, first the critical temperatures of eight DES systems have been calculated based on the Eötvos empirical equation using the experimental data of the density and surface tension at various temperatures, then the density and surface tension values of these systems were predicted from the calculated critical temperatures. For the density prediction the Eötvos and Guggenheim equations were combined to introduce a simple power law equation using the estimated critical temperatures from the Eötvos and the Modified Lydersen–Joback–Reid group contribution methods. Finally, the estimated critical temperatures by these two methods were used in the Guggenheim empirical equation to calculate the surface tension of the DES systems. The prediction quality of the two physical properties under investigation were compared and proper recommendations were postulated

  16. The approximate determination of the critical temperature of a liquid by measuring surface tension versus the temperature

    International Nuclear Information System (INIS)

    Maroto, J A; Nieves, F J de las; Quesada-Perez, M

    2004-01-01

    A classical experience in a physics student laboratory is to determine the surface tension of a liquid versus the temperature and to check the linear appearance of the obtained graph. In this work we show a simple method to estimate the critical temperature of three liquids by using experimental data of surface tension at different temperatures. By a logarithm fitting between surface tension and temperature, the critical temperature can be determined and compared with data from the literature. For two liquids (butanol and nitrobenzene) the comparison is acceptable but the differences are too high for the third liquid (water). By discussing the results it seems to be clear that the difference between the critical temperature of the liquid and the maximum temperature of the surface tension measurements is the determining factor in obtaining acceptable results. From this study it is possible to obtain more information on the liquid characteristics from surface tension measurements that are currently carried out in a student laboratory. Besides, in this paper it is shown how to select the most suitable liquids which provide both acceptable values for the critical temperature and measurements of the surface tension at moderate temperatures. The complementary use of numerical methods permits us to offer a complete experience for the students with a simple laboratory experiment which we recommend for physics students in advanced university courses

  17. The Equilibrium Spreading Tension of Pulmonary Surfactant

    OpenAIRE

    Dagan, Maayan P.; Hall, Stephen B.

    2015-01-01

    Monomolecular films at an air/water interface coexist at the equilibrium spreading tension (γe) with the bulk phase from which they form. For individual phospholipids, γe is single-valued, and separates conditions at which hydrated vesicles adsorb from tensions at which overcompressed monolayers collapse. With pulmonary surfactant, isotherms show that monolayers compressed on the surface of bubbles coexist with the three-dimensional collapsed phase over a range of surface tensions. γe therefo...

  18. Tension perturbations of black brane spacetimes

    International Nuclear Information System (INIS)

    Traschen, Jennie; Fox, Daniel

    2004-01-01

    We consider black brane spacetimes that have at least one spatial translation Killing field that is tangent to the brane. A new parameter, the tension of a spacetime, is defined. The tension parameter is associated with spatial translations in much the same way that the ADM mass is associated with the time translation Killing field. In this work, we explore the implications of the spatial translation symmetry for small perturbations around a background black brane. For static-charged black branes we derive a law which relates the tension perturbation to the surface gravity times the change in the horizon area, plus terms that involve variations in the charges and currents. We find that as a black brane evaporates the tension decreases. We also give a simple derivation of a first law for black brane spacetimes. These constructions hold when the background stress-energy is governed by a Hamiltonian, and the results include arbitrary perturbative stress-energy sources

  19. Measurement for Surface Tension of Aqueous Inorganic Salt

    Directory of Open Access Journals (Sweden)

    Jiming Wen

    2018-03-01

    Full Text Available Bubble columns are effective means of filtration in filtered containment venting systems. Here, the surface tension has a significant influence on bubble size distribution and bubble deformation, which have a strong impact on the behavior of the bubble column. The influence of aqueous inorganic compounds on the surface tension depends on the electrolytic activity, Debye length, entropy of ion hydration, and surface deficiencies or excess. In this work, the surface tensions of same specific aqueous solutions have been measured by different methods including platinum plate method, platinum ring method, and maximum bubble pressure method. The measured surface tensions of both sodium hydroxide and sodium thiosulfate are less than that of water. As solution temperature ranges from 20 to 75°C, the surface tension of 0.5 mol/L sodium hydroxide solution decreases from 71 to 55 mN/m while that of 1 mol/L solution decreases from 60 to 45 mN/m. Similarly during the same temperature range, the surface tension of 0.5 mol/L sodium thiosulfate decreases from 70 to 38 mN/m, and that of 1 mol/L sodium thiosulfate is between 68 and 36 mN/m. The analysis for the influence mechanism of aqueous inorganic on surface tension is provided. In addition, experimental results show that the surface tension of solid aerosol suspension liquid has no obvious difference from that of distilled water.

  20. Geometrical properties of tension-induced fractures in granite

    International Nuclear Information System (INIS)

    Sato, Hisashi; Sawada, Atsushi; Yasuhara, Hideaki

    2011-03-01

    Considering a safe, long-term sequestration of energy byproducts such as high level radioactive wastes, it is of significant importance to well-constrain the hydraulic and transport behavior of targeted permeants within fractured rocks. Specifically, fluid flow within low-permeability crystalline rock masses (e.g., granite) is often dominated by transport in through-cutting fractures, and thus careful considerations are needed on the behavior. There are three planes along that granites fail most easily under tension, and those may be identified as the rift, grain, and hardway planes. This anisotropic fabric may be attributed to preferentially oriented microcrack sets contained within intact rock. In this research, geometrical properties of tension-induced fractures are evaluated as listed below; (1) Creation of tension-induced fractures considering the anisotropy clarified by elastic wave measurements. (2) Evaluation of geometrical properties in those fractures characterized by the anisotropy. In the item (1), the three planes of rift, grain and hardway were identified by measuring elastic wave. In the item (2), JRC, variogram, fractal dimension and distributions of elevations in the fracture surfaces were evaluated using digitized data of the fracture surfaces measured via a laser profilometry. Results show that rift planes are less rougher than the other planes of grain and hardway, and grain planes are generically rougher than the other planes of rift and hardway. It was also confirmed that the fracture shape anisotropy was correlated with the direction of the slit which constructed during tensile tests. On the other hand, the tendency peculiar to the direction of slit and granites fail about the estimated aperture distribution from fracture shape was not seen. (author)

  1. Hybrid vehicle assessment. Phase I. Petroleum savings analysis

    Energy Technology Data Exchange (ETDEWEB)

    Levin, R.; Liddle, S.; Deshpande, G.; Trummel, M.; Vivian, H.

    1984-03-01

    This report presents the results of a comprehensive analysis of near-term electric-hybrid vehicles. Its purpose was to estimate their potential to save significant amounts of petroleum on a national scale in the 1990s. Performance requirements and expected annual usage patterns of these vehicles were first modeled. The projected US fleet composition was estimated, and conceptual hybrid vehicle designs were conceived and analyzed for petroleum use when driven in the expected annual patterns. These petroleum consumption estimates were then compared to similar estimates for projected 1990 conventional vehicles having the same performance and driven in the same patterns. Results are presented in the form of three utility functions and comparisons of several conceptual designs are made. The Hybrid Vehicle (HV) design and assessment techniques are discussed and a general method is explained for selecting the optimum energy management strategy for any vehicle-mission-battery combination. A discussion of lessons learned during the construction and test of the General Electric Hybrid Test Vehicle is also presented. Conclusions and recommendations are presented, and development recommendations are identified.

  2. Tending the tensions in co-creation

    DEFF Research Database (Denmark)

    Phillips, Professor MSO Louise; Nordentoft, Helle Merete; Pedersen, Lektor Christina Hee

    -for-granted positive value. In the panel we de-romanticise “co-creation” and explore how it is enacted in particular organisational contexts, concentrating on context-specific tensions arising in the meeting between different knowledge forms and interests. These include tensions BETWEEN dialogic views of knowledge co-creation...

  3. Surface tension in soap films: revisiting a classic demonstration

    International Nuclear Information System (INIS)

    Behroozi, F

    2010-01-01

    We revisit a classic demonstration for surface tension in soap films and introduce a more striking variation of it. The demonstration shows how the film, pulling uniformly and normally on a loose string, transforms it into a circular arc under tension. The relationship between the surface tension and the string tension is analysed and presented in a useful graphical form. (letters and comments)

  4. Surface tension in soap films: revisiting a classic demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, F [Department of Physics, University of Northern Iowa, Cedar Falls, IA 50614 (United States)], E-mail: behroozi@uni.edu

    2010-01-15

    We revisit a classic demonstration for surface tension in soap films and introduce a more striking variation of it. The demonstration shows how the film, pulling uniformly and normally on a loose string, transforms it into a circular arc under tension. The relationship between the surface tension and the string tension is analysed and presented in a useful graphical form. (letters and comments)

  5. Bending Under Tension Test with Direct Friction Measurement

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Olsson, David Dam; Chodnikiewicz, K.

    2006-01-01

    A special Bending-Under-Tension (BUT) transducer has been developed in which friction around the tool radius can be directly measured when drawing a plane sheet strip around a cylindrical tool-pin under constant back tension. The front tension, back tension and torque on the tool-pin are all...... measured directly, thus enabling accurate measurement of friction and direct determination of lubricant film breakdown for varying normal pressure, sliding speed, tool radius and tool preheat temperature. The transducer is applied in an experimental investigation focusing on limits of lubrication...

  6. Magnetic tension and gravitational collapse

    International Nuclear Information System (INIS)

    Tsagas, Christos G

    2006-01-01

    The gravitational collapse of a magnetized medium is investigated by studying qualitatively the convergence of a timelike family of non-geodesic worldlines in the presence of a magnetic field. Focusing on the field's tension, we illustrate how the winding of the magnetic forcelines due to the fluid's rotation assists the collapse, while shear-like distortions in the distribution of the field's gradients resist contraction. We also show that the relativistic coupling between magnetism and geometry, together with the tension properties of the field, lead to a magneto-curvature stress that opposes the collapse. This tension stress grows stronger with increasing curvature distortion, which means that it could potentially dominate over the gravitational pull of the matter. If this happens, a converging family of non-geodesic worldlines can be prevented from focusing without violating the standard energy conditions

  7. Muscle trigger point therapy in tension-type headache.

    Science.gov (United States)

    Alonso-Blanco, Cristina; de-la-Llave-Rincón, Ana Isabel; Fernández-de-las-Peñas, César

    2012-03-01

    Recent evidence suggests that active trigger points (TrPs) in neck and shoulder muscles contribute to tension-type headache. Active TrPs within the suboccipital, upper trapezius, sternocleidomastoid, temporalis, superior oblique and lateral rectus muscles have been associated with chronic and episodic tension-type headache forms. It seems that the pain profile of this headache may be provoked by referred pain from active TrPs in the posterior cervical, head and shoulder muscles. In fact, the presence of active TrPs has been related to a higher degree of sensitization in tension-type headache. Different therapeutic approaches are proposed for proper TrP management. Preliminary evidence indicates that inactivation of TrPs may be effective for the management of tension-type headache, particularly in a subgroup of patients who may respond positively to this approach. Different treatment approaches targeted to TrP inactivation are discussed in the current paper, focusing on tension-type headache. New studies are needed to further delineate the relationship between muscle TrP inactivation and tension-type headache.

  8. Patients with tension-type headaches feel stigmatized

    Directory of Open Access Journals (Sweden)

    Sanjay Prakash

    2016-01-01

    Full Text Available The author, a sufferer of tension-type headache (TTH, believes that the word "tension" in "tension-type headache" carries a social stigma and that patients do not accept a diagnosis of TTH readily. TTH is the most common primary headache disorder. The disability of TTH as a burden of society is greater than that of migraine. Absenteeism because of TTH is higher than that due to migraine. However, patients with TTH do not go for consultation. Even the prevalence of new daily persistent headache (NDPH is 12 times higher at the headache clinic than that of chronic TTH (CTTH. These points hint that TTH patients probably do not want to visit the clinic. The author believes that it could be because of the stigma attached to "tension." Herein, the author has noted the first responses given by 50 consecutive patients with TTH when they were told that they had been suffering from TTH. The first answer of 64% of patients with TTH was "I do not have any tension/stress ." This denial is similar to the denial declared by patients with depression. Depression and tension are similar in the sense that both are considered as a signs of personal weakness. Such a preconception in the society creates a stigma, and patients deny the diagnosis, conceal symptoms, and become reluctant to seek help and treatment.

  9. Exploring the Use of Interactive Digital Storytelling Video: Promoting Student Engagement and Learning in a University Hybrid Course

    Science.gov (United States)

    Shelton, Catharyn C.; Warren, Annie E.; Archambault, Leanna M.

    2016-01-01

    This study explores interactive digital storytelling in a university hybrid course. Digital stories leverage imagery and narrative-based content to explore concepts, while appealing to millennials. When digital storytelling is used as the main source of course content, tensions arise regarding how to engage and support student learning while…

  10. Application of Matrix Pencil Algorithm to Mobile Robot Localization Using Hybrid DOA/TOA Estimation

    Directory of Open Access Journals (Sweden)

    Lan Anh Trinh

    2012-12-01

    Full Text Available Localization plays an important role in robotics for the tasks of monitoring, tracking and controlling a robot. Much effort has been made to address robot localization problems in recent years. However, despite many proposed solutions and thorough consideration, in terms of developing a low-cost and fast processing method for multiple-source signals, the robot localization problem is still a challenge. In this paper, we propose a solution for robot localization with regards to these concerns. In order to locate the position of a robot, both the coordinate and the orientation of a robot are necessary. We develop a localization method using the Matrix Pencil (MP algorithm for hybrid detection of direction of arrival (DOA and time of arrival (TOA. TOA of the signal is estimated for computing the distance between the mobile robot and a base station (BS. Based on the distance and the estimated DOA, we can estimate the mobile robot's position. The characteristics of the algorithm are examined through analysing simulated experiments and the results demonstrate the advantages of our method over previous works in dealing with the above challenges. The method is constructed based on the low-cost infrastructure of radio frequency devices; the DOA/TOA estimation is performed with just single value decomposition for fast processing. Finally, the MP algorithm combined with tracking using a Kalman filter allows our proposed method to locate the positions of multiple source signals.

  11. An Accurate FFPA-PSR Estimator Algorithm and Tool for Software Effort Estimation

    Directory of Open Access Journals (Sweden)

    Senthil Kumar Murugesan

    2015-01-01

    Full Text Available Software companies are now keen to provide secure software with respect to accuracy and reliability of their products especially related to the software effort estimation. Therefore, there is a need to develop a hybrid tool which provides all the necessary features. This paper attempts to propose a hybrid estimator algorithm and model which incorporates quality metrics, reliability factor, and the security factor with a fuzzy-based function point analysis. Initially, this method utilizes a fuzzy-based estimate to control the uncertainty in the software size with the help of a triangular fuzzy set at the early development stage. Secondly, the function point analysis is extended by the security and reliability factors in the calculation. Finally, the performance metrics are added with the effort estimation for accuracy. The experimentation is done with different project data sets on the hybrid tool, and the results are compared with the existing models. It shows that the proposed method not only improves the accuracy but also increases the reliability, as well as the security, of the product.

  12. Markov Chain Monte Carlo (MCMC) methods for parameter estimation of a novel hybrid redundant robot

    International Nuclear Information System (INIS)

    Wang Yongbo; Wu Huapeng; Handroos, Heikki

    2011-01-01

    This paper presents a statistical method for the calibration of a redundantly actuated hybrid serial-parallel robot IWR (Intersector Welding Robot). The robot under study will be used to carry out welding, machining, and remote handing for the assembly of vacuum vessel of International Thermonuclear Experimental Reactor (ITER). The robot has ten degrees of freedom (DOF), among which six DOF are contributed by the parallel mechanism and the rest are from the serial mechanism. In this paper, a kinematic error model which involves 54 unknown geometrical error parameters is developed for the proposed robot. Based on this error model, the mean values of the unknown parameters are statistically analyzed and estimated by means of Markov Chain Monte Carlo (MCMC) approach. The computer simulation is conducted by introducing random geometric errors and measurement poses which represent the corresponding real physical behaviors. The simulation results of the marginal posterior distributions of the estimated model parameters indicate that our method is reliable and robust.

  13. Assessing Tillage Effects on Soil Hydraulic Properties via Inverse Parameter Estimation using Tension Infiltrometry

    Science.gov (United States)

    Schwen, Andreas; Bodner, Gernot; Loiskandl, Willibald

    2010-05-01

    Hydraulic properties are key factors controlling water and solute movement in soils. While several recent studies have focused on the assessment of the spatial variability of hydraulic properties, the temporal dynamics are commonly not taken into account, primarily because its measurement is costly and time-consuming. However, there is extensive empirical evidence that these properties are subject to temporal changes, particularly in the near-saturated range where soil structure strongly influences water flow. One main source of temporal variability is soil tillage. It can improve macroporosity by loosening the soil and thereby changing the pore-size distribution. Since these modifications are quite unstable over time, the pore space partially collapses after tillage. This effect should be largest for conventional tillage (CT), where the soil is ploughed after harvest every year. Assessing the effect of different tillage treatments on the temporal variability of hydraulic properties requires adequate measurement techniques. Tension infiltrometry has become a popular and convenient method providing not only the hydraulic conductivity function but also the soil rentention properties. The inverse estimation of parameters from infiltration measurements remains challenging, despite some progress since the first approach of Šimůnek et al. (1998). Measured data like the cumulative infiltration, the initial and final volumetric water content, as well as independently measured retention data from soil core analysis with laboratory methods, have to be considered to find an optimum solution describing the soil's pore space. In the present study we analysed tension infiltration measurements obtained several times between August 2008 and December 2009 on an arable field in the Moravian Basin, Lower Austria. The tillage treatments were conventional tillage including ploughing (CT), reduced tillage with chisel only (RT), and no-tillage treatment using a direct seeding

  14. Ultrasound Findings in Tension Pneumothorax: A Case Report.

    Science.gov (United States)

    Inocencio, Maxine; Childs, Jeannine; Chilstrom, Mikaela L; Berona, Kristin

    2017-06-01

    Delayed recognition of tension pneumothorax can lead to a mortality of 31% to 91%. However, the classic physical examination findings of tracheal deviation and distended neck veins are poorly sensitive in the diagnosis of tension pneumothorax. Point-of-care ultrasound is accurate in identifying the presence of pneumothorax, but sonographic findings of tension pneumothorax are less well described. We report the case of a 21-year-old man with sudden-onset left-sided chest pain. He was clinically stable without hypoxia or hypotension, and the initial chest x-ray study showed a large pneumothorax without mediastinal shift. While the patient was awaiting tube thoracostomy, a point-of-care ultrasound demonstrated findings of mediastinal shift and a dilated inferior vena cava (IVC) concerning for tension physiology, even though the patient remained hemodynamically stable. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case demonstrates a unique clinical scenario of ultrasound evidence of tension physiology in a clinically stable patient. Although this patient was well appearing without hypotension, respiratory distress, tracheal deviation, or distended neck veins, point-of-care ultrasound revealed mediastinal shift and a plethoric IVC. Given that the classic clinical signs of tension pneumothorax are not uniformly present, this case shows how point-of-care ultrasound may diagnose tension pneumothorax before clinical decompensation. Published by Elsevier Inc.

  15. Tension and relaxation in the individual.

    Science.gov (United States)

    Newbury, C R

    1979-06-01

    Increasing materialism in society is resulting in more wide spread nervous tension in all age groups. While some degree of nervous tension is necessary in everyday living, its adverse effects require that we must learn to bring it under control. Total tension is shown to have two components: a controllable element arising from factors in the environment and the inbuilt uncontrollable residue which is basic in the individual temperament. The effects of excessive or uncontrolled stress can be classified as 1) emotional reactions such as neurotic behaviour (anxiety hypochondria, hysteria, phobia, depression obsessions and compulsions) or psychotic behaviour and 2) psychosomatic reactions (nervous asthma, headache, insomnia, heart attack). Nervous energy can be wastefully expended by such factors as loss of temper, wrong attitudes to work, job frustration and marital strains. Relaxation is the only positive way to control undesirable nervous tension and its techniques require to be learned. A number of techniques (progressive relaxation, differential relaxation, hypnosis, the use of biofeedback, Yoga and Transcendental Meditation) are described and their application to dental practice is discussed.

  16. Hybrid Firefly Variants Algorithm for Localization Optimization in WSN

    Directory of Open Access Journals (Sweden)

    P. SrideviPonmalar

    2017-01-01

    Full Text Available Localization is one of the key issues in wireless sensor networks. Several algorithms and techniques have been introduced for localization. Localization is a procedural technique of estimating the sensor node location. In this paper, a novel three hybrid algorithms based on firefly is proposed for localization problem. Hybrid Genetic Algorithm-Firefly Localization Algorithm (GA-FFLA, Hybrid Differential Evolution-Firefly Localization Algorithm (DE-FFLA and Hybrid Particle Swarm Optimization -Firefly Localization Algorithm (PSO-FFLA are analyzed, designed and implemented to optimize the localization error. The localization algorithms are compared based on accuracy of estimation of location, time complexity and iterations required to achieve the accuracy. All the algorithms have hundred percent estimation accuracy but with variations in the number of firefliesr requirements, variation in time complexity and number of iteration requirements. Keywords: Localization; Genetic Algorithm; Differential Evolution; Particle Swarm Optimization

  17. Emergency percutaneous needle decompression for tension pneumoperitoneum

    Directory of Open Access Journals (Sweden)

    Körner Markus

    2011-05-01

    Full Text Available Abstract Background Tension pneumoperitoneum as a complication of iatrogenic bowel perforation during endoscopy is a dramatic condition in which intraperitoneal air under pressure causes hemodynamic and ventilatory compromise. Like tension pneumothorax, urgent intervention is required. Immediate surgical decompression though is not always possible due to the limitations of the preclinical management and sometimes to capacity constraints of medical staff and equipment in the clinic. Methods This is a retrospective analysis of cases of pneumoperitoneum and tension pneumoperitoneum due to iatrogenic bowel perforation. All patients admitted to our surgical department between January 2005 and October 2010 were included. Tension pneumoperitoneum was diagnosed in those patients presenting signs of hemodynamic and ventilatory compromise in addition to abdominal distension. Results Between January 2005 and October 2010 eleven patients with iatrogenic bowel perforation were admitted to our surgical department. The mean time between perforation and admission was 36 ± 14 hrs (range 30 min - 130 hrs, between ER admission and begin of the operation 3 hrs and 15 min ± 47 min (range 60 min - 9 hrs. Three out of eleven patients had clinical signs of tension pneumoperitoneum. In those patients emergency percutaneous needle decompression was performed with a 16G venous catheter. This improved significantly the patients' condition (stabilization of vital signs, reducing jugular vein congestion, bridging the time to the start of the operation. Conclusions Hemodynamical and respiratory compromise in addition to abdominal distension shortly after endoscopy are strongly suggestive of tension pneumoperitoneum due to iatrogenic bowel perforation. This is a rare but life threatening condition and it can be managed in a preclinical and clinical setting with emergency percutaneous needle decompression like tension pneumothorax. Emergency percutaneous decompression is no

  18. On the Problem of Determining Aggregation Numbers from Surface Tension Measurements.

    Science.gov (United States)

    Rusanov, Anatoly I

    2017-11-07

    In view of the recent discovery of variable aggregation numbers in the vicinity of the critical micelle concentration (CMC), the mass-action-law theory of the surface tension isotherm of a micellar solution with variable aggregation numbers is formulated both for nonionic and ionic surfactants. It is shown that the shape of the surface tension isotherm should be concave in the logarithmic scale above the CMC. Considering a change in the isotherm slope at the CMC apparent break point, the problems of determining the aggregation number for nonionic micelles and the degree of counterion binding for ionic micelles are discussed. In case of the aggregation number variability near the CMC, finding the aggregation number above the CMC apparent break point is considered and a computational scheme is elaborated, requiring a higher precision for experiment. Some experimental data from the literature are analyzed, and the method of estimating the degree of counterion binding is improved.

  19. [Diagnostic and therapy of tension-type headache].

    Science.gov (United States)

    Straube, A

    2014-08-01

    Episodic headache of the tension type is the most prevalent primary headache with a lifetime prevalence of about 78 %. Clinical characteristics are a dull, moderate, holocephalic headache without accompanying autonomic or vegetative symptoms. The episodic tension-type headache often lasts only 30 min up to a maximum of a few days. In contrast to this clinically often undemanding headache, chronic tension-type headache can cause considerable disability in patients. The 1-year prevalence is 1-3 % of the population. All therapy strategies combine nonpharmaceutical therapy such as education of the patient, regular aerobic exercise, and psychological treatment (e.g., Jacobson's progressive muscle relaxation etc.) with pharmaceutical treatment such as tricyclic antidepressants or combined serotonergic and noradrenergic antidepressants. Combination therapy has been proven to be more effective than singular strategies; however, the chronic tension-type headache still poses a therapeutic problem.

  20. Mitochondrial Respiration and Oxygen Tension.

    Science.gov (United States)

    Shaw, Daniel S; Meitha, Karlia; Considine, Michael J; Foyer, Christine H

    2017-01-01

    Measurements of respiration and oxygen tension in plant organs allow a precise understanding of mitochondrial capacity and function within the context of cellular oxygen metabolism. Here we describe methods that can be routinely used for the isolation of intact mitochondria, and the determination of respiratory electron transport, together with techniques for in vivo determination of oxygen tension and measurement of respiration by both CO 2 production and O 2 consumption that enables calculation of the respiratory quotient [CO 2 ]/[O 2 ].

  1. Hybrid islanding detection method by using grid impedance estimation in parallel-inverters-based microgrid

    DEFF Research Database (Denmark)

    Ghzaiel, Walid; Jebali-Ben Ghorbal, Manel; Slama-Belkhodja, Ilhem

    2014-01-01

    This paper presents a hybrid islanding detection algorithm integrated on the distributed generation unit more close to the point of common coupling of a Microgrid based on parallel inverters where one of them is responsible to control the system. The method is based on resonance excitation under...... parameters, both resistive and inductive parts, from the injected resonance frequency determination. Finally, the inverter will disconnect the microgrid from the faulty grid and reconnect the parallel inverter system to the controllable distributed system in order to ensure high power quality. This paper...... shows that grid impedance variation detection estimation can be an efficient method for islanding detection in microgrid systems. Theoretical analysis and simulation results are presented to validate the proposed method....

  2. Prediction of tension-type headache risk in adolescents

    Directory of Open Access Journals (Sweden)

    K. A. Stepanchenko

    2016-08-01

    Full Text Available Tension-type headache is the actual problem of adolescent neurology, which is associated with the prevalence of the disease, the tendency of the disease to the chronic course and a negative impact on performance in education, work capacity and quality of patients’ life. The aim. To develop a method for prediction of tension-type headache occurrence in adolescents. Materials and methods. 2342 adolescent boys and girls at the age of 13-17 years in schools of Kharkiv were examined. We used questionnaire to identify the headache. A group of adolescents with tension-type headache - 1430 people (61.1% was selected. The control group included 246 healthy adolescents. Possible risk factors for tension-type headache formation were divided into 4 groups: genetic, biomedical, psychosocial and social. Mathematical prediction of tension-type headache risk in adolescents was performed using the method of intensive indicators normalization of E.N. Shigan, which was based on probabilistic Bayesian’s method. The result was presented in the form of prognostic coefficients. Results. The most informative risk factors for tension-type headache development were the diseases, from which the teenager suffered after 1 year (sleep disorders, gastrointestinal diseases, autonomic disorders in the family history, traumatic brain injury, physical inactivity, poor adaptation of the patient in the kindergarten and school, stresses. Diagnostic scale has been developed to predict the risk of tension-type headache. It includes 23 prognostic factors with their gradation and meaning of integrated risk indicator, depending on individual factor strength influence. The risk of tension-type headache development ranged from 25,27 to 81,43 values of prognostic coefficient (low probability (25,27-43,99, the average probability (43,99-62,71 and high probability (62,71- 81,43. Conclusion. The study of tension-type headache risk factors, which were obtained by using an assessed and

  3. Optimal Orientation Planning and Control Deviation Estimation on FAST Cable-Driven Parallel Robot

    Directory of Open Access Journals (Sweden)

    Hui Li

    2014-03-01

    Full Text Available The paper is devoted theoretically to the optimal orientation planning and control deviation estimation of FAST cable-driven parallel robot. Regarding the robot characteristics, the solutions are obtained from two constrained optimizations, both of which are based on the equilibrium of the cabin and the attention on force allocation among 6 cable tensions. A kind of control algorithm is proposed based on the position and force feedbacks. The analysis proves that the orientation control depends on force feedback and the optimal tension solution corresponding to the planned orientation. Finally, the estimation of orientation deviation is given under the limit range of tension errors.

  4. Combined tension and bending testing of tapered composite laminates

    Science.gov (United States)

    O'Brien, T. Kevin; Murri, Gretchen B.; Hagemeier, Rick; Rogers, Charles

    1994-11-01

    A simple beam element used at Bell Helicopter was incorporated in the Computational Mechanics Testbed (COMET) finite element code at the Langley Research Center (LaRC) to analyze the responce of tappered laminates typical of flexbeams in composite rotor hubs. This beam element incorporated the influence of membrane loads on the flexural response of the tapered laminate configurations modeled and tested in a combined axial tension and bending (ATB) hydraulic load frame designed and built at LaRC. The moments generated from the finite element model were used in a tapered laminated plate theory analysis to estimate axial stresses on the surface of the tapered laminates due to combined bending and tension loads. Surfaces strains were calculated and compared to surface strains measured using strain gages mounted along the laminate length. The strain distributions correlated reasonably well with the analysis. The analysis was then used to examine the surface strain distribution in a non-linear tapered laminate where a similarly good correlation was obtained. Results indicate that simple finite element beam models may be used to identify tapered laminate configurations best suited for simulating the response of a composite flexbeam in a full scale rotor hub.

  5. Modeling and state-of-charge prediction of lithium-ion battery and ultracapacitor hybrids with a co-estimator

    International Nuclear Information System (INIS)

    Wang, Yujie; Liu, Chang; Pan, Rui; Chen, Zonghai

    2017-01-01

    The modeling and state-of-charge estimation of the batteries and ultracapacitors are crucial to the battery/ultracapacitor hybrid energy storage system. In recent years, the model based state estimators are welcomed widely, since they can adjust the gain according to the error between the model predictions and measurements timely. In most of the existing algorithms, the model parameters are either configured by theoretical values or identified off-line without adaption. But in fact, the model parameters always change continuously with loading wave or self-aging, and the lack of adaption will reduce the estimation accuracy significantly. To overcome this drawback, a novel co-estimator is proposed to estimate the model parameters and state-of-charge simultaneously. The extended Kalman filter is employed for parameter updating. To reduce the convergence time, the recursive least square algorithm and the off-line identification method are used to provide initial values with small deviation. The unscented Kalman filter is employed for the state-of-charge estimation. Because the unscented Kalman filter takes not only the measurement uncertainties but also the process uncertainties into account, it is robust to the noise. Experiments are executed to explore the robustness, stability and precision of the proposed method. - Highlights: • A co-estimator is proposed to estimate the model parameters and state-of-charge. • The extended Kalman filter is used for model parameter adaption. • The unscented Kalman filter is designed for state estimation with strong robust. • The dynamic profiles are employed to verify the proposed co-estimator.

  6. Planck and the local Universe: quantifying the tension

    CERN Document Server

    Verde, Licia; Protopapas, Pavlos

    2013-01-01

    We use the latest Planck constraints, and in particular constraints on the derived parameters (Hubble constant and age of the Universe) for the local universe and compare them with local measurements of the same quantities. We propose a way to quantify whether cosmological parameters constraints from two different experiments are in tension or not. Our statistic, T, is an evidence ratio and therefore can be interpreted with the widely used Jeffrey's scale. We find that in the framework of the LCDM model, the Planck inferred two dimensional, joint, posterior distribution for the Hubble constant and age of the Universe is in "strong" tension with the local measurements; the odds being ~ 1:50. We explore several possibilities for explaining this tension and examine the consequences both in terms of unknown errors and deviations from the LCDM model. In some one-parameter LCDM model extensions, tension is reduced whereas in other extensions, tension is instead increased. In particular, small total neutrino masses ...

  7. Effects of surface tension on tray point efficiencies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, G.X.; Afacan, A.; Chuang, K.T. (Alberta Univ., Edmonton, AB (Canada))

    1994-08-01

    Sieve tray efficiencies for the distillation of methanol/water, acetic acid/water, and cyclohexane/n-heptane mixtures were measured as a function of composition under fixed vapor and liquid rates in a 0.15 m diameter distillation column. The three binary distillation systems used in the study had a wide range of surface tensions measured as a function of composition. From the efficiencies measured, the number of vapor- and liquid-phase transfer units (Ng and Nl) was determined and the effects of surface tension on Ng and Nl were identified. To further verify the results obtained from the distillation column, bubble sizes in froths for air/water, air/methanol, and air/(water + surfactant) systems with different surface tensions were measured. The results show that surface tension has a significant effect on tray efficiency and the number of transfer units. Bubble sizes in the tray froths were mainly determined by surface tension, and bubble breakup and coalescence occur in the froths. 45 refs., 15 figs., 1 tab.

  8. Evolution of hybrid defect networks

    International Nuclear Information System (INIS)

    Martins, C. J. A. P.

    2009-01-01

    We apply a recently developed analytic model for the evolution of monopole networks to the case of monopoles attached to one string, usually known as hybrid networks. We discuss scaling solutions for both local and global hybrid networks, and also find an interesting application for the case of vortons. Our quantitative results agree with previous estimates in indicating that the hybrid networks will usually annihilate soon after the string-forming phase transition. However, we also show that in some specific circumstances these networks can survive considerably more than a Hubble time.

  9. Bearing Stress at Failure of Double-Lap Hybrid Joints in Woven Fabric Kenaf Fiber Composite Plates under Quasi-static Loading

    Directory of Open Access Journals (Sweden)

    Lee Sim Yee

    2017-01-01

    Full Text Available The present paper is focused on the bearing stress at failure of double-lap woven fabric kenaf fiber reinforced polymer (KFRP hybrid bonded-bolted joints in experimental frameworks. The effects of different normalized plate width (plate width/hole diameter, W/d, lay-up types and bolt loads were incorporated in current study as specified in testing series. Generally, hybrid joint coupons separated within adhesive layer prior to net-tension failure or bearing/net-tension failure. The bearing stress at failure increased as W/d ratio increment, critical W/d is given as four and three in clamped and finger tight condition respectively. Lay-up types present insignificant effect to bearing stress at failure due to low volume fiber fraction in kenaf fiber composites. Combination of thicker and clamped conditions plate demonstrated greater bearing stress than equivalent finger-tight (FT conditions due to higher load transferred from friction, as expected.

  10. Free energies of stable and metastable pores in lipid membranes under tension.

    Science.gov (United States)

    den Otter, Wouter K

    2009-11-28

    The free energy profile of pore formation in a lipid membrane, covering the entire range from a density fluctuation in an intact bilayer to a large tension-stabilized pore, has been calculated by molecular dynamics simulations with a coarse-grained lipid model. Several fixed elongations are used to obtain the Helmholtz free energy as a function of pore size for thermodynamically stable, metastable, and unstable pores, and the system-size dependence of these elongations is discussed. A link to the Gibbs free energy at constant tension, commonly known as the Litster model, is established by a Legendre transformation. The change of genus upon pore formation is exploited to estimate the saddle-splay modulus or Gaussian curvature modulus of the membrane leaflets. Details are provided of the simulation approach, which combines the potential of mean constraint force method with a reaction coordinate based on the local lipid density.

  11. Characterisation of the joining zone of serially arranged hybrid semi-finished components

    Science.gov (United States)

    Behrens, B.-A.; Chugreev, A.; Matthias, T.

    2018-05-01

    Forming of already joined semi-finished products is an innovative approach to manufacture components which are well-adapted to external loads. This approach results in an economically and ecologically improved production by the targeted use of high-quality materials in component areas, which undergo high stresses. One possible production method for hybrid semi-finished products is friction welding. This welding method allows for the production of hybrid semi-finished products made of aluminium and steel as well as steel and steel. In this paper, the thermomechanical tensile and shear stresses causing a failure of the joined zone are experimentally determined through tension tests. These tests are performed with specimens whose joint zones are aligned with different angles to the load direction.

  12. Effect of Ageing on the Passive and Active Tension and Pharmacodynamic Characteristics of Rat Coronary Arteries

    DEFF Research Database (Denmark)

    Sheykhzade, Majid; Simonsen, Anja Hviid; Boonen, Harrie C.M.

    2012-01-01

    The influence of ageing on the passive and active tension and pharmacodynamic characteristics of intramural coronary arteries from 3-month-old and 2-year-old male Wistar rats was investigated using an isometric myograph. The passive vessel wall tension measured in Ca2+-free physiological salt...... solution at L0 was significantly greater in arteries from old rats (1.46 ± 0.10 Nm–1, n = 7) than in young rats (1.13 ± 0.13 Nm–1, n = 6). However, the maximal active tension at L0 was similar. The spontaneous myogenic tone was increased by age and the vasorelaxation induced by extracellular K...... from both young and old rats. The slopes of the regression lines of the Schild plots were not significantly different from unity and the estimated pKB values for ketanserin were similar. In conclusion, ageing is associated with changes in passive mechanical characteristics as well as changes...

  13. An automatic tension measurement system of MWPC wires

    International Nuclear Information System (INIS)

    D'Antone, I.; Lolli, M.; Torromeo, G.

    1992-01-01

    An electronic system is presented for automatic mechanical tension measurement to test wire chambers. The developed system works in the tension range from 50 g to 300 g; this large working range is obtained by using a microcontroller that performs a digital control on the bridge of an oscillator containing the wire of which the tension has to be measured. The microcontroller automatically brings the system towards the oscillation condition and subsequently, measuring the frequency, it evaluates, displays and sends to a host computer the value of the mechanical tension of the wires. The system is precise and allows fast measurements. A description of the hardware and software design is given. (orig.)

  14. A Hybrid Imagination

    DEFF Research Database (Denmark)

    Jamison, Andrew; Christensen, Steen Hyldgaard; Botin, Lars

    “hubris” that is so much taken for granted in contemporary science and engineering discourses and practices with a sense of cooperation and social responsibility. The book portrays the history of science and technology as an underlying tension between hubris – literally the ambition to “play god...... an alternative approach, devoting special attention to the role played by social and cultural movements in the making of science and technology. They show how social and cultural movements, from the Renaissance of the late 15th century to the environmental and global justice movements of our time, have provided......” on the part of many a scientist and engineer and neglect the consequences - and a hybrid imagination, connecting scientific “facts” and technological “artifacts” with cultural understanding. The book concludes with chapters on the recent transformations in the modes of scientific and technological production...

  15. Gastrothorax or tension pneumothorax: A diagnostic dilemma

    Directory of Open Access Journals (Sweden)

    Singh Sarvesh

    2011-01-01

    Full Text Available Gastrothorax, a rare complication following thoracoabdominal aortic aneurysm repair, is reported. The clinical features of a gastrothorax and tension pneumothorax are similar and thus, a gastrothorax can masquerade as a tension pneumothorax. The diagnosis is made by a high level of clinical suspicion, chest X-ray shows a distended stomach with air fluid levels and a computerised tomography is useful in assessing the diaphragm and establishing the positions of the various intra-abdominal organs. Also, the risk of an intercostal drainage tube placement and the role of nasogastric tube in avoiding the development of a tension gastrothorax is highlighted.

  16. Smart Battery Thermal Management for PHEV Efficiency Une gestion avancée de la thermique de la batterie basse tension de traction pour optimiser l’efficacité d’un véhicule hybride électrique rechargeable

    Directory of Open Access Journals (Sweden)

    Lefebvre L.

    2013-03-01

    Full Text Available A smart battery thermal management is crucial for vehicle performances and battery lifetime targets achievements when electric and plug-in hybrid electric vehicles are concerned. The thermal system needs to be designed and tuned in accordance and compromises with powertrain and vehicle requirements, battery pack architecture, environmental constraints, costs, weight, etc., in a process that will be described in the first part of this paper. Among the portfolio of battery thermal management technologies, these items will be illustrated by two examples: thermal management by cabin air and by refrigerant in a direct cooling, enlightening a decision process. A simplified battery thermo-electric simulation model, which the second part of our work focuses on, has been built, first for both thermal and energetic balance dimensioning of the battery thermal management system. Examples are given on these two perspectives. That simplified simulation model has also identified some promising thermal management strategies for improving vehicle efficiency and performances and battery lifetime. That is the task of the last part of this paper. Battery heating has shown opportunities for improving energy and power availability at cold conditions and, thus, electric drive availability and autonomy. Post-cooling the battery at the end of a journey and its pre-conditioning before the following journey, not only improve vehicle efficiency, electric drive availability and autonomy, but also enhance battery lifetime and compromises with cabin thermal comfort. Others promising strategies optimizing the relation between vehicle performances and battery lifetime are still under investigations. L’atteinte des performances et des prestations requises d’un véhicule électrique ou hybride électrique rechargeable nécessite un thermomanagement intelligent de la batterie basse tension de traction. Ce thermomanagement est incontournable pour respecter dans le même temps

  17. Tension Hydrothorax Related to Disseminated Endometriosis

    Directory of Open Access Journals (Sweden)

    AnnaKate Deal, MD

    2016-01-01

    Full Text Available We present the case of a 34-year-old woman presenting to the emergency department (ED with dyspnea, cough, and fever. She was found to have a tension hydrothorax and was treated with ultrasound-guided thoracentesis in the ED. Subsequent inpatient evaluation showed the patient had disseminated endometriosis. Tension hydrothorax has not been previously described in the literature as a complication of this disease.

  18. Rein tension acceptance in young horses in a voluntary test situation.

    Science.gov (United States)

    Christensen, J W; Zharkikh, T L; Antoine, A; Malmkvist, J

    2011-03-01

    During riding, horses are frequently exposed to pressure from the rider, e.g. through the bit and reins, but few studies have investigated at which point rein tension becomes uncomfortable for the horse. To investigate how much rein tension young inexperienced horses are willing to accept in order to obtain a food reward; whether the tension acceptance changes during 3 consecutive test days; and whether rein tension correlates with the expression of conflict behaviour and heart rate. Pressure-naïve horses will apply only little rein tension in the first voluntary trial, but their acceptance will gradually increase. High levels of rein tension will lead to expression of conflict behaviour and increases in heart rate. Fifteen 2-year-old, bridle-naïve mares were encouraged to stretch their head forward (across a 0.95 m high metal bar) to obtain a food reward in a voluntary test situation. On each test day, each horse was exposed to 2 control sessions (loose reins), an intermediate and a short rein session (1 min/session). Rein tension, heart rate and behaviour were recorded. The horses applied significantly more tension on the first day (mean rein tension: 10.2 N), compared to the second and third test day (Day 2: 6.0 and Day 3: 5.7 N). The horses showed significantly more conflict behaviour in the short rein treatment. There was no treatment effect on heart rate. The horses applied the highest rein tension on the first day, and apparently learned to avoid the tension, rather than habituate to it. Rein tension correlated with expression of conflict behaviour, indicating that the horses found the tension aversive. Further studies should focus on the correlation between rein tension and conflict behaviour in ridden horses. © 2010 EVJ Ltd.

  19. Surface tension of liquid Al-Cu binary alloys.

    OpenAIRE

    Schmitz, Julianna; Brillo, Jürgen; Egry, Ivan; Schmid-Fetzer, Rainer

    2009-01-01

    Surface tension data of liquid Al–Cu binary alloys have been measured contactlessly using the technique of electromagnetic levitation. A digital CMOS-camera (400 fps) recorded image sequences of the oscillating liquid sample and surface tensions were determined from analysis of the frequency spectra. Measurements were performed for samples covering the entire range of composition and precise data were obtained in a broad temperature range. It was found that the surface tensions can ...

  20. Associations between stress and migraine and tension-type headache: results from a school-based study in adolescents from grammar schools in Germany.

    Science.gov (United States)

    Milde-Busch, Astrid; Blaschek, Astrid; Heinen, Florian; Borggräfe, Ingo; Koerte, Inga; Straube, Andreas; Schankin, Christoph; von Kries, Rüdiger

    2011-05-01

    Stress is considered the major contributor to migraine and tension-type headache in adolescents. Previous studies have focused on general stressors, whereas the aim of the present study was to investigate associations between individuals' stressful experiences and different types of headache. Adolescents from 10th and 11th grades of grammar schools filled in questionnaires. Stressful experiences were measured with the Trier Inventory of Chronic Stress. Type of headache was classified according to the International Classification of Headache Disorders. Linear regressions, adjusted for sex and grade, were calculated to estimate differences in stress scores that can be attributed to migraine, tension-type headache or miscellaneous headache. A total of 1260 questionnaires were analysed. Tension-type headache, migraine and co-existing migraine plus tension-type headache were found in 48.7%, 10.2% and 19.8% of the participants. In subjects with migraine or co-existing migraine plus tension-type headache, high increases in stress scores were found in all investigated dimensions, whereas much weaker and inconsistent associations were found in subjects with tension-type headache only. The characteristic of migraine is more associated with stressful experiences than this is the case for tension-type headache. This suggests that adolescent migraine patients might especially benefit from behavioural interventions regarding stress.

  1. Estimation method of state-of-charge for lithium-ion battery used in hybrid electric vehicles based on variable structure extended kalman filter

    Science.gov (United States)

    Sun, Yong; Ma, Zilin; Tang, Gongyou; Chen, Zheng; Zhang, Nong

    2016-07-01

    Since the main power source of hybrid electric vehicle(HEV) is supplied by the power battery, the predicted performance of power battery, especially the state-of-charge(SOC) estimation has attracted great attention in the area of HEV. However, the value of SOC estimation could not be greatly precise so that the running performance of HEV is greatly affected. A variable structure extended kalman filter(VSEKF)-based estimation method, which could be used to analyze the SOC of lithium-ion battery in the fixed driving condition, is presented. First, the general lower-order battery equivalent circuit model(GLM), which includes column accumulation model, open circuit voltage model and the SOC output model, is established, and the off-line and online model parameters are calculated with hybrid pulse power characteristics(HPPC) test data. Next, a VSEKF estimation method of SOC, which integrates the ampere-hour(Ah) integration method and the extended Kalman filter(EKF) method, is executed with different adaptive weighting coefficients, which are determined according to the different values of open-circuit voltage obtained in the corresponding charging or discharging processes. According to the experimental analysis, the faster convergence speed and more accurate simulating results could be obtained using the VSEKF method in the running performance of HEV. The error rate of SOC estimation with the VSEKF method is focused in the range of 5% to 10% comparing with the range of 20% to 30% using the EKF method and the Ah integration method. In Summary, the accuracy of the SOC estimation in the lithium-ion battery cell and the pack of lithium-ion battery system, which is obtained utilizing the VSEKF method has been significantly improved comparing with the Ah integration method and the EKF method. The VSEKF method utilizing in the SOC estimation in the lithium-ion pack of HEV can be widely used in practical driving conditions.

  2. Embracing Tensions in Feminist Organizational Communication Pedagogies

    Science.gov (United States)

    Linabary, Jasmine R.; Long, Ziyu; Mouton, Ashton; Rao, Ranjani L.; Buzzanell, Patrice M.

    2017-01-01

    Feminist pedagogies hold potential to create more inclusive and transformative classrooms. Adopting a tension-centered approach, we draw on our individual and collective reflections on the design and instruction of a multi-section undergraduate organizational communication course to build an autoethnographic account of the tensions associated with…

  3. Tension Pneumothorax following an Accidental Kerosene Poisoning ...

    African Journals Online (AJOL)

    Tension pneumothorax is a rare complication following an accidental kerosene poisoning. In such situation, a bed-side needle thoracocentesis is performed because of its potential of becoming fatal; hence its clinical importance. A case of 15 month old boy with tension pneumothorax following accidental kerosene ...

  4. J-integral analysis of heterogeneous mismatched girth welds in clamped single-edge notched tension specimens

    International Nuclear Information System (INIS)

    Hertelé, Stijn; De Waele, Wim; Verstraete, Matthias; Denys, Rudi; O'Dowd, Noel

    2014-01-01

    Flaw assessment procedures require a quantification of crack driving force, and such procedures are generally based on the assumption of weld homogeneity. However, welds generally have a heterogeneous microstructure, which will influence the crack driving force. This paper describes a stress-based methodology to assess complex heterogeneous welds using a J-based approach. Clamped single-edge notched tension specimens, representative of girth weld flaws, are analyzed and the influence of weld heterogeneity on crack driving force has been determined. The use of a modified limit load for heterogeneous welds is proposed, suitable for implementation in a ‘homogenized’ J-integral estimation scheme. It follows from an explicit modification of an existing solution for centre cracked tension specimens. The proposed solution provides a good estimate of crack driving force and any errors in the approximation may be accounted for by means of a small safety factor on load bearing capacity. - Highlights: • We present a crack driving force estimation procedure for heterogeneous welds. • The procedure is based on a ‘homogenized’ version of the EPRI equation. • Complex welds are translated into equivalent idealized mismatched welds. • The procedure is validated for clamped SE(T) specimens. • A mismatch limit load for clamped SE(T) specimens is developed

  5. 2D Unitary ESPRIT Based Super-Resolution Channel Estimation for Millimeter-Wave Massive MIMO with Hybrid Precoding

    KAUST Repository

    Liao, Anwen

    2017-11-01

    Millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) with hybrid precoding is a promising technique for the future 5G wireless communications. Due to a large number of antennas but a much smaller number of radio frequency (RF) chains, estimating the high-dimensional mmWave massive MIMO channel will bring the large pilot overhead. To overcome this challenge, this paper proposes a super-resolution channel estimation scheme based on two-dimensional (2D) unitary ESPRIT algorithm. By exploiting the angular sparsity of mmWave channels, the continuously distributed angle of arrivals/departures (AoAs/AoDs) can be jointly estimated with high accuracy. Specifically, by designing the uplink training signals at both base station (BS) and mobile station (MS), we first use low pilot overhead to estimate a low-dimensional effective channel, which has the same shift-invariance of array response as the high-dimensional mmWave MIMO channel to be estimated. From the low-dimensional effective channel, the superresolution estimates of AoAs and AoDs can be jointly obtained by exploiting the 2D unitary ESPRIT channel estimation algorithm. Furthermore, the associated path gains can be acquired based on the least squares (LS) criterion. Finally, we can reconstruct the high-dimensional mmWave MIMO channel according to the obtained AoAs, AoDs, and path gains. Simulation results have confirmed that the proposed scheme is superior to conventional schemes with a much lower pilot overhead.

  6. 2D Unitary ESPRIT Based Super-Resolution Channel Estimation for Millimeter-Wave Massive MIMO with Hybrid Precoding

    KAUST Repository

    Liao, Anwen; Gao, Zhen; Wu, Yongpeng; Wang, Hua; Alouini, Mohamed-Slim

    2017-01-01

    Millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) with hybrid precoding is a promising technique for the future 5G wireless communications. Due to a large number of antennas but a much smaller number of radio frequency (RF) chains, estimating the high-dimensional mmWave massive MIMO channel will bring the large pilot overhead. To overcome this challenge, this paper proposes a super-resolution channel estimation scheme based on two-dimensional (2D) unitary ESPRIT algorithm. By exploiting the angular sparsity of mmWave channels, the continuously distributed angle of arrivals/departures (AoAs/AoDs) can be jointly estimated with high accuracy. Specifically, by designing the uplink training signals at both base station (BS) and mobile station (MS), we first use low pilot overhead to estimate a low-dimensional effective channel, which has the same shift-invariance of array response as the high-dimensional mmWave MIMO channel to be estimated. From the low-dimensional effective channel, the superresolution estimates of AoAs and AoDs can be jointly obtained by exploiting the 2D unitary ESPRIT channel estimation algorithm. Furthermore, the associated path gains can be acquired based on the least squares (LS) criterion. Finally, we can reconstruct the high-dimensional mmWave MIMO channel according to the obtained AoAs, AoDs, and path gains. Simulation results have confirmed that the proposed scheme is superior to conventional schemes with a much lower pilot overhead.

  7. The application of computational thermodynamics and a numerical model for the determination of surface tension and Gibbs-Thomson coefficient of aluminum based alloys

    International Nuclear Information System (INIS)

    Jacome, Paulo A.D.; Landim, Mariana C.; Garcia, Amauri; Furtado, Alexandre F.; Ferreira, Ivaldo L.

    2011-01-01

    Highlights: → Surface tension and the Gibbs-Thomson coefficient are computed for Al-based alloys. → Butler's scheme and ThermoCalc are used to compute the thermophysical properties. → Predictive cell/dendrite growth models depend on accurate thermophysical properties. → Mechanical properties can be related to the microstructural cell/dendrite spacing. - Abstract: In this paper, a solution for Butler's formulation is presented permitting the surface tension and the Gibbs-Thomson coefficient of Al-based binary alloys to be determined. The importance of Gibbs-Thomson coefficient for binary alloys is related to the reliability of predictions furnished by predictive cellular and dendritic growth models and of numerical computations of solidification thermal variables, which will be strongly dependent on the thermophysical properties assumed for the calculations. A numerical model based on Powell hybrid algorithm and a finite difference Jacobian approximation was coupled to a specific interface of a computational thermodynamics software in order to assess the excess Gibbs energy of the liquid phase, permitting the surface tension and Gibbs-Thomson coefficient for Al-Fe, Al-Ni, Al-Cu and Al-Si hypoeutectic alloys to be calculated. The computed results are presented as a function of the alloy composition.

  8. Modeling and Density Estimation of an Urban Freeway Network Based on Dynamic Graph Hybrid Automata.

    Science.gov (United States)

    Chen, Yangzhou; Guo, Yuqi; Wang, Ying

    2017-03-29

    In this paper, in order to describe complex network systems, we firstly propose a general modeling framework by combining a dynamic graph with hybrid automata and thus name it Dynamic Graph Hybrid Automata (DGHA). Then we apply this framework to model traffic flow over an urban freeway network by embedding the Cell Transmission Model (CTM) into the DGHA. With a modeling procedure, we adopt a dual digraph of road network structure to describe the road topology, use linear hybrid automata to describe multi-modes of dynamic densities in road segments and transform the nonlinear expressions of the transmitted traffic flow between two road segments into piecewise linear functions in terms of multi-mode switchings. This modeling procedure is modularized and rule-based, and thus is easily-extensible with the help of a combination algorithm for the dynamics of traffic flow. It can describe the dynamics of traffic flow over an urban freeway network with arbitrary topology structures and sizes. Next we analyze mode types and number in the model of the whole freeway network, and deduce a Piecewise Affine Linear System (PWALS) model. Furthermore, based on the PWALS model, a multi-mode switched state observer is designed to estimate the traffic densities of the freeway network, where a set of observer gain matrices are computed by using the Lyapunov function approach. As an example, we utilize the PWALS model and the corresponding switched state observer to traffic flow over Beijing third ring road. In order to clearly interpret the principle of the proposed method and avoid computational complexity, we adopt a simplified version of Beijing third ring road. Practical application for a large-scale road network will be implemented by decentralized modeling approach and distributed observer designing in the future research.

  9. Pore-scale simulation of wettability and interfacial tension effects on flooding process for enhanced oil recovery.

    Science.gov (United States)

    Zhao, Jin; Wen, Dongsheng

    2017-08-27

    For enhanced oil recovery (EOR) applications, the oil/water flow characteristics during the flooding process was numerically investigated with the volume-of-fluid method at the pore scale. A two-dimensional pore throat-body connecting structure was established, and four scenarios were simulated in this paper. For oil-saturated pores, the wettability effect on the flooding process was studied; for oil-unsaturated pores, three effects were modelled to investigate the oil/water phase flow behaviors, namely the wettability effect, the interfacial tension (IFT) effect, and the combined wettability/IFT effect. The results show that oil saturated pores with the water-wet state can lead to 25-40% more oil recovery than with the oil-wet state, and the remaining oil mainly stays in the near wall region of the pore bodies for oil-wet saturated pores. For oil-unsaturated pores, the wettability effects on the flooding process can help oil to detach from the pore walls. By decreasing the oil/water interfacial tension and altering the wettability from oil-wet to water-wet state, the remaining oil recovery rate can be enhanced successfully. The wettability-IFT combined effect shows better EOR potential compared with decreasing the interfacial tension alone under the oil-wet condition. The simulation results in this work are consistent with previous experimental and molecular dynamics simulation conclusions. The combination effect of the IFT reducation and wettability alteration can become an important recovery mechanism in future studies for nanoparticles, surfactant, and nanoparticle-surfactant hybrid flooding process.

  10. Length and elasticity of side reins affect rein tension at trot.

    Science.gov (United States)

    Clayton, Hilary M; Larson, Britt; Kaiser, LeeAnn J; Lavagnino, Michael

    2011-06-01

    This study investigated the horse's contribution to tension in the reins. The experimental hypotheses were that tension in side reins (1) increases biphasically in each trot stride, (2) changes inversely with rein length, and (3) changes with elasticity of the reins. Eight riding horses trotted in hand at consistent speed in a straight line wearing a bit and bridle and three types of side reins (inelastic, stiff elastic, compliant elastic) were evaluated in random order at long, neutral, and short lengths. Strain gauge transducers (240 Hz) measured minimal, maximal and mean rein tension, rate of loading and impulse. The effects of rein type and length were evaluated using ANOVA with Bonferroni post hoc tests. Rein tension oscillated in a regular pattern with a peak during each diagonal stance phase. Within each rein type, minimal, maximal and mean tensions were higher with shorter reins. At neutral or short lengths, minimal tension increased and maximal tension decreased with elasticity of the reins. Short, inelastic reins had the highest maximal tension and rate of loading. Since the tension variables respond differently to rein elasticity at different lengths, it is recommended that a set of variables representing different aspects of rein tension should be reported. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Study of alteration in the mechanical properties in hybrid nanocomposite of polypropylene/sisal fibers/mineral clay irradiated with gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Nilson C.; Terence, Mauro C.; Miranda, Leila F., E-mail: nilpereira@mackenzie.com.b [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Escola de Engenharia. Curso de Engenharia de Materiais

    2009-07-01

    A new material class formed with reinforced filler, hybrid of organic and inorganic materials provides the technological development of materials with modified properties. And among great numbers of properties that can be modified by presence of hybrid filler to stand out the tension resistance. Polymer shows behavior of tensions and deformation that are not related of simple form. The answer of this material at mechanicals solicitations depends of structural factors and externals variables. As structural factors can be, for example, molecular weight, ramifications and crosslink. As external variables can be, for example, temperature, time or velocity of deformation, kind of solicitation and others. This work was possible to verify as nanostructures materials behavior, mechanically, after were submitted gamma radiation. This work utilized as polymeric matrix, recycled polypropylene, and as hybrid filler, a mixture of montimorillonite mineral clay with natural sisal fibers. It is known that form to magnify the tensile resistance is increase the number of crosslink of principal chain for gamma radiation. After irradiation the polypropylene was crosslinked structures that are result recombination of radicals formed during process of irradiation. It.s known that radicals formed occur preferentially in the amorphous region of polymer. Considering that polymeric matrix polypropylene, without addition fillers suffer strong structural influence when irradiated, was possible verify change in the extension, tensile strength and also maxim tensile in rupture, when this matrix was incorporated with fillers hybrids. (author)

  12. Study of alteration in the mechanical properties in hybrid nanocomposite of polypropylene/sisal fibers/mineral clay irradiated with gamma rays

    International Nuclear Information System (INIS)

    Pereira, Nilson C.; Terence, Mauro C.; Miranda, Leila F.

    2009-01-01

    A new material class formed with reinforced filler, hybrid of organic and inorganic materials provides the technological development of materials with modified properties. And among great numbers of properties that can be modified by presence of hybrid filler to stand out the tension resistance. Polymer shows behavior of tensions and deformation that are not related of simple form. The answer of this material at mechanicals solicitations depends of structural factors and externals variables. As structural factors can be, for example, molecular weight, ramifications and crosslink. As external variables can be, for example, temperature, time or velocity of deformation, kind of solicitation and others. This work was possible to verify as nanostructures materials behavior, mechanically, after were submitted gamma radiation. This work utilized as polymeric matrix, recycled polypropylene, and as hybrid filler, a mixture of montimorillonite mineral clay with natural sisal fibers. It is known that form to magnify the tensile resistance is increase the number of crosslink of principal chain for gamma radiation. After irradiation the polypropylene was crosslinked structures that are result recombination of radicals formed during process of irradiation. It.s known that radicals formed occur preferentially in the amorphous region of polymer. Considering that polymeric matrix polypropylene, without addition fillers suffer strong structural influence when irradiated, was possible verify change in the extension, tensile strength and also maxim tensile in rupture, when this matrix was incorporated with fillers hybrids. (author)

  13. Improved practical formulas for estimation of cable tension by vibration method; Shindoho ni yoru cable choryoku jitsuyo santeishiki no hosei

    Energy Technology Data Exchange (ETDEWEB)

    Zui, H. [Setsunan University, Osaka (Japan). Faculty of Engineering; Shinke, T. [Kobe Technical College, Kobe, Kobe (Japan); Hamazaki, Y. [Kobe Steel, Ltd., Kobe (Japan)

    1995-10-21

    The vibration method is usually utilized on the measurement of cable tension during construction of cable bridge such as Nielsen bridges or cable stayed bridges. Practical formula for the vibration method previously proposed by authors is often used where bending rigidity is taken into account. These formula, however, have a certain limit of application and do not yield good results when the cable is not slender or not enough mentioned. The practical formula is modified to improve the accuracy and new formulas are made. The new practical formulas are applicable to any cables, regardless of its length and tension in it. The accuracy is confirmed through comparison of the value obtained by practical formulas with measured values and calculated value by F.E.M. 2 refs., 4 figs., 1 tab.

  14. Hybrid discrete choice models: Gained insights versus increasing effort

    Energy Technology Data Exchange (ETDEWEB)

    Mariel, Petr, E-mail: petr.mariel@ehu.es [UPV/EHU, Economía Aplicada III, Avda. Lehendakari Aguire, 83, 48015 Bilbao (Spain); Meyerhoff, Jürgen [Institute for Landscape Architecture and Environmental Planning, Technical University of Berlin, D-10623 Berlin, Germany and The Kiel Institute for the World Economy, Duesternbrooker Weg 120, 24105 Kiel (Germany)

    2016-10-15

    Hybrid choice models expand the standard models in discrete choice modelling by incorporating psychological factors as latent variables. They could therefore provide further insights into choice processes and underlying taste heterogeneity but the costs of estimating these models often significantly increase. This paper aims at comparing the results from a hybrid choice model and a classical random parameter logit. Point of departure for this analysis is whether researchers and practitioners should add hybrid choice models to their suite of models routinely estimated. Our comparison reveals, in line with the few prior studies, that hybrid models gain in efficiency by the inclusion of additional information. The use of one of the two proposed approaches, however, depends on the objective of the analysis. If disentangling preference heterogeneity is most important, hybrid model seems to be preferable. If the focus is on predictive power, a standard random parameter logit model might be the better choice. Finally, we give recommendations for an adequate use of hybrid choice models based on known principles of elementary scientific inference. - Highlights: • The paper compares performance of a Hybrid Choice Model (HCM) and a classical Random Parameter Logit (RPL) model. • The HCM indeed provides insights regarding preference heterogeneity not gained from the RPL. • The RPL has similar predictive power as the HCM in our data. • The costs of estimating HCM seem to be justified when learning more on taste heterogeneity is a major study objective.

  15. Hybrid discrete choice models: Gained insights versus increasing effort

    International Nuclear Information System (INIS)

    Mariel, Petr; Meyerhoff, Jürgen

    2016-01-01

    Hybrid choice models expand the standard models in discrete choice modelling by incorporating psychological factors as latent variables. They could therefore provide further insights into choice processes and underlying taste heterogeneity but the costs of estimating these models often significantly increase. This paper aims at comparing the results from a hybrid choice model and a classical random parameter logit. Point of departure for this analysis is whether researchers and practitioners should add hybrid choice models to their suite of models routinely estimated. Our comparison reveals, in line with the few prior studies, that hybrid models gain in efficiency by the inclusion of additional information. The use of one of the two proposed approaches, however, depends on the objective of the analysis. If disentangling preference heterogeneity is most important, hybrid model seems to be preferable. If the focus is on predictive power, a standard random parameter logit model might be the better choice. Finally, we give recommendations for an adequate use of hybrid choice models based on known principles of elementary scientific inference. - Highlights: • The paper compares performance of a Hybrid Choice Model (HCM) and a classical Random Parameter Logit (RPL) model. • The HCM indeed provides insights regarding preference heterogeneity not gained from the RPL. • The RPL has similar predictive power as the HCM in our data. • The costs of estimating HCM seem to be justified when learning more on taste heterogeneity is a major study objective.

  16. Tension Stiffened and Tendon Actuated Manipulator

    Science.gov (United States)

    Doggett, William R. (Inventor); Dorsey, John T. (Inventor); Ganoe, George G. (Inventor); King, Bruce D. (Inventor); Jones, Thomas C. (Inventor); Mercer, Charles D. (Inventor); Corbin, Cole K. (Inventor)

    2015-01-01

    A tension stiffened and tendon actuated manipulator is provided performing robotic-like movements when acquiring a payload. The manipulator design can be adapted for use in-space, lunar or other planetary installations as it is readily configurable for acquiring and precisely manipulating a payload in both a zero-g environment and in an environment with a gravity field. The manipulator includes a plurality of link arms, a hinge connecting adjacent link arms together to allow the adjacent link arms to rotate relative to each other and a cable actuation and tensioning system provided between adjacent link arms. The cable actuation and tensioning system includes a spreader arm and a plurality of driven and non-driven elements attached to the link arms and the spreader arm. At least one cable is routed around the driven and non-driven elements for actuating the hinge.

  17. Ultimate stress increase in unbonded tendons in post-tensioned indeterminate I-beams cast with high strength normal and self compacting concrete

    Directory of Open Access Journals (Sweden)

    Yousef Askari Dolatabad

    2018-06-01

    Full Text Available The use of un-bonded tendons is prevalent in post-tensioned concrete structures. Equations for prediction of stress in un-bonded tendons of post-tensioned normal (vibrating concrete flexural members have been given in various codes. They are based on experience and don’t account all of important parameters such as concrete strength (normal and high strength and its type (vibrating and non-vibrating concrete. Since self-compacting concrete (SCC is nearly a new innovation therefore, understanding the implementation of this type of non-vibrating concrete on the ultimate unbonded tendon stress is critical. For this aim, in this paper there are presented experimental results of six continuous un-bonded post-tensioned I-beams in two groups were casted and monitored by different electrical strain gauges. In the first tested group, the beams (UPN1-12, UPN1-18, UPN1-22 were consisting of high strength normal concrete (HSNC where as in the second group (UPS1-12, UPS1-18, UPS1-22 high strength self-compacting concrete (HSSCC were tested. The variables included the type of concrete and percentage of bounded non-prestressed steel. Experimental monitored results of ultimate stress increase in unbonded tendons are compared with predicted equations of different researchers and standards. It was found that, the proposed equation is in better agreement with the test results. The results of standard error of estimate Sy/x, indicates that for two types of HSCs, the ACI 318-2011 provides better estimates than AASHTO-2010 model whereas this model provides better estimates than BS 8110-97. Keywords: Post-tensioned, Unbonded tendons, Stress increase, High strength normal and self-compacting concrete, Continuous beams

  18. Probabilistic modelling and analysis of stand-alone hybrid power systems

    International Nuclear Information System (INIS)

    Lujano-Rojas, Juan M.; Dufo-López, Rodolfo; Bernal-Agustín, José L.

    2013-01-01

    As a part of the Hybrid Intelligent Algorithm, a model based on an ANN (artificial neural network) has been proposed in this paper to represent hybrid system behaviour considering the uncertainty related to wind speed and solar radiation, battery bank lifetime, and fuel prices. The Hybrid Intelligent Algorithm suggests a combination of probabilistic analysis based on a Monte Carlo simulation approach and artificial neural network training embedded in a genetic algorithm optimisation model. The installation of a typical hybrid system was analysed. Probabilistic analysis was used to generate an input–output dataset of 519 samples that was later used to train the ANNs to reduce the computational effort required. The generalisation ability of the ANNs was measured in terms of RMSE (Root Mean Square Error), MBE (Mean Bias Error), MAE (Mean Absolute Error), and R-squared estimators using another data group of 200 samples. The results obtained from the estimation of the expected energy not supplied, the probability of a determined reliability level, and the estimation of expected value of net present cost show that the presented model is able to represent the main characteristics of a typical hybrid power system under uncertain operating conditions. - Highlights: • This paper presents a probabilistic model for stand-alone hybrid power system. • The model considers the main sources of uncertainty related to renewable resources. • The Hybrid Intelligent Algorithm has been applied to represent hybrid system behaviour. • The installation of a typical hybrid system was analysed. • The results obtained from the study case validate the presented model

  19. A hybrid system approach to airspeed, angle of attack and sideslip estimation in Unmanned Aerial Vehicles

    KAUST Repository

    Shaqura, Mohammad

    2015-06-01

    Fixed wing Unmanned Aerial Vehicles (UAVs) are an increasingly common sensing platform, owing to their key advantages: speed, endurance and ability to explore remote areas. While these platforms are highly efficient, they cannot easily be equipped with air data sensors commonly found on their larger scale manned counterparts. Indeed, such sensors are bulky, expensive and severely reduce the payload capability of the UAVs. In consequence, UAV controllers (humans or autopilots) have little information on the actual mode of operation of the wing (normal, stalled, spin) which can cause catastrophic losses of control when flying in turbulent weather conditions. In this article, we propose a real-time air parameter estimation scheme that can run on commercial, low power autopilots in real-time. The computational method is based on a hybrid decomposition of the modes of operation of the UAV. A Bayesian approach is considered for estimation, in which the estimated airspeed, angle of attack and sideslip are described statistically. An implementation on a UAV is presented, and the performance and computational efficiency of this method are validated using hardware in the loop (HIL) simulation and experimental flight data and compared with classical Extended Kalman Filter estimation. Our benchmark tests shows that this method is faster than EKF by up to two orders of magnitude. © 2015 IEEE.

  20. Parachute Cord Tension Sensor

    Data.gov (United States)

    National Aeronautics and Space Administration — To design and fabricate a light weight (few oz), very small (~2 inch length) parachute cord tension sensor demonstrator device.A major challenge for the CPAS (The...

  1. Tension-filled Governance?

    DEFF Research Database (Denmark)

    Celik, Tim Holst

    on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...

  2. Focal adhesions, stress fibers and mechanical tension

    Energy Technology Data Exchange (ETDEWEB)

    Burridge, Keith, E-mail: Keith_Burridge@med.unc.edu [Department of Cell Biology and Physiology, and Lineberger Comprehensive Cancer Center, 12-016 Lineberger, CB#7295, University of North Carolina, Chapel Hill, NC (United States); Guilluy, Christophe, E-mail: christophe.guilluy@univ-nantes.fr [Inserm UMR-S1087, CNRS UMR-C6291, L' institut du Thorax, and Université de Nantes, Nantes (France)

    2016-04-10

    Stress fibers and focal adhesions are complex protein arrays that produce, transmit and sense mechanical tension. Evidence accumulated over many years led to the conclusion that mechanical tension generated within stress fibers contributes to the assembly of both stress fibers themselves and their associated focal adhesions. However, several lines of evidence have recently been presented against this model. Here we discuss the evidence for and against the role of mechanical tension in driving the assembly of these structures. We also consider how their assembly is influenced by the rigidity of the substratum to which cells are adhering. Finally, we discuss the recently identified connections between stress fibers and the nucleus, and the roles that these may play, both in cell migration and regulating nuclear function. - Highlights: • The different types of stress fiber and focal adhesion are described. • We discuss the controversy about tension and assembly of these structures. • We describe the different models used to investigate assembly of these structures. • The influence of substratum rigidity is discussed. • Stress fiber connections to the nucleus are reviewed.

  3. The law of corresponding states and surface tension of metals

    International Nuclear Information System (INIS)

    Digilov, R.

    2001-01-01

    Full Text: Surface tension of liquid metals is one of fundamental and most important quantities in theory and practice of material processing and its temperature dependence leads to the well-known Marangoni convection. Although currently methods are sufficiently precise to measure the surface tension, there are uncertainties in experimental data and its temperature dependence mainly due to impurity, which even a trace of it strongly affects the results of measurements. The theoretical treatment from the first principles is unwieldy and not always permits one to calculate the surface tension with certainty. Another active research field deals with empirical correlation between the surface tension and bulk thermodynamic properties, which we interpret as a simple consequence of the law of corresponding states. In order to relate the surface tension and to bulk properties of liquid metals the reduced formula is derived by scaling with the melting point T m (0) at p = 0 and atomic volume Ω 0 2/3 at T = 0 K as macroscopic parameters for scaling ε and a characterizing the interatomic potential in metals. The reduced surface tension and the reduced surface entropy obtained in high temperature limit are discussed and compared with the experiment. The reduced temperature coefficient of the surface tension found is a universal constant for the metals of the same structure. It is shown that pressure dependence of the surface tension, so called baric coefficient of the surface tension, can be described by pressure dependence of scaling parameters T m (p) and Ω 0 (p). (author)

  4. Influence on cervical MR imaging by tension. Comparison between the picture quality of cervical MR image and tension

    International Nuclear Information System (INIS)

    Iseki, Tadahiro; Okano, Tamotsu; Kanou, Norio; Tanaka, Kazuharu; Kawasaki, Kouichi; Kawachi, Toshiaki

    2003-01-01

    In our first report, we compared influence on cervical MR image (C-MRI) by fear and anxiety on between the first time and experienced patients, in which the significant difference was not seen between those patients. Then, the present study, we made a comparison of the picture sharpness of C-MRI on between patients who were in states of tension and not, and on among tense patients by several causes. Our study showed the tendency which the good quality pictures were easy to be obtained in the experienced patients who were tensely and the poor quality pictures were in the patients who were not, which could not demonstrated the statistical significant difference. However, as compared the respective cause which induces tension with the picture sharpness, the patients with tenses caused by MR device showed to be difficult to be obtained the good quality pictures. The present study suggested that ''unsuitable tension'', which was overstrung due to fear and anxiety from MR device, was difficult to obtain good quality picture of C-MRI, and that ''suitable tension'', with which could be kept still during the examination, was easy to do it. (author)

  5. Tensions between Teams and Their Leaders

    Directory of Open Access Journals (Sweden)

    J. David Johnson

    2016-10-01

    Full Text Available The intersection of teamwork and leadership results in tensions, dilemmas, and paradoxes for both individuals and for institutions such as simultaneously empowering individuals at the same time it frustrates them when our naive, cultural understanding of leadership centralizes power and values leaders who can impose their will and vision on others. Perhaps the fundamental paradox of teamwork and leadership is that the more leadership is focused on an individual the less likely a team’s potential will be realized. Six specific domains where tensions arise are: at team boundaries; culture; who is in charge, rationality/cognition; diversity; and collaborations. Three approaches - clarifying different levels of analysis, temporal factors, and overarching concepts - to resolving tensions are discussed. New conceptions of leadership and the importance of the larger cultural frame within which they are embedded are needed for the management of technology and innovation.

  6. Bending Under Tension Test with Direct Friction Measurement

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Olsson, David Dam; Chodnikiewicz, K.

    2004-01-01

    A special BUT-transducer has been developed in which friction around the tool radius can be directly measured when drawing a plane sheet strip around a cylindrical tool-pin under constant back tension. The front tension, back tension and torque on the tool-pin are all measured directly, thus...... enabling accurate measurement of friction and direct determination of lubricant film breakdown for varying normal pressure, sliding speed, tool radius and tool preheat temperature. The transducer is applied in an experimental investigation focusing on limits of lubrication in drawing of stainless steel...

  7. Parameter estimation for chaotic systems using a hybrid adaptive cuckoo search with simulated annealing algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Zheng, E-mail: 19994035@sina.com [College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101 (China); Wang, Jun; Zhou, Bihua [National Defense Key Laboratory on Lightning Protection and Electromagnetic Camouflage, PLA University of Science and Technology, Nanjing 210007 (China); Zhou, Shudao [College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101 (China); Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044 (China)

    2014-03-15

    This paper introduces a novel hybrid optimization algorithm to establish the parameters of chaotic systems. In order to deal with the weaknesses of the traditional cuckoo search algorithm, the proposed adaptive cuckoo search with simulated annealing algorithm is presented, which incorporates the adaptive parameters adjusting operation and the simulated annealing operation in the cuckoo search algorithm. Normally, the parameters of the cuckoo search algorithm are kept constant that may result in decreasing the efficiency of the algorithm. For the purpose of balancing and enhancing the accuracy and convergence rate of the cuckoo search algorithm, the adaptive operation is presented to tune the parameters properly. Besides, the local search capability of cuckoo search algorithm is relatively weak that may decrease the quality of optimization. So the simulated annealing operation is merged into the cuckoo search algorithm to enhance the local search ability and improve the accuracy and reliability of the results. The functionality of the proposed hybrid algorithm is investigated through the Lorenz chaotic system under the noiseless and noise condition, respectively. The numerical results demonstrate that the method can estimate parameters efficiently and accurately in the noiseless and noise condition. Finally, the results are compared with the traditional cuckoo search algorithm, genetic algorithm, and particle swarm optimization algorithm. Simulation results demonstrate the effectiveness and superior performance of the proposed algorithm.

  8. Parameter estimation for chaotic systems using a hybrid adaptive cuckoo search with simulated annealing algorithm

    International Nuclear Information System (INIS)

    Sheng, Zheng; Wang, Jun; Zhou, Bihua; Zhou, Shudao

    2014-01-01

    This paper introduces a novel hybrid optimization algorithm to establish the parameters of chaotic systems. In order to deal with the weaknesses of the traditional cuckoo search algorithm, the proposed adaptive cuckoo search with simulated annealing algorithm is presented, which incorporates the adaptive parameters adjusting operation and the simulated annealing operation in the cuckoo search algorithm. Normally, the parameters of the cuckoo search algorithm are kept constant that may result in decreasing the efficiency of the algorithm. For the purpose of balancing and enhancing the accuracy and convergence rate of the cuckoo search algorithm, the adaptive operation is presented to tune the parameters properly. Besides, the local search capability of cuckoo search algorithm is relatively weak that may decrease the quality of optimization. So the simulated annealing operation is merged into the cuckoo search algorithm to enhance the local search ability and improve the accuracy and reliability of the results. The functionality of the proposed hybrid algorithm is investigated through the Lorenz chaotic system under the noiseless and noise condition, respectively. The numerical results demonstrate that the method can estimate parameters efficiently and accurately in the noiseless and noise condition. Finally, the results are compared with the traditional cuckoo search algorithm, genetic algorithm, and particle swarm optimization algorithm. Simulation results demonstrate the effectiveness and superior performance of the proposed algorithm

  9. Dead space and slope indices from the expiratory carbon dioxide tension-volume curve

    OpenAIRE

    Kars, Alice; Bogaard, Jan; Stijnen, Theo; Vries, J.; Verbraak, Anton; Hilvering, C.

    1997-01-01

    textabstractThe slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate (PIE), were investigated in 28 healthy control subjects, 12 asthma and 29 emphysema patients (20 severely obstructed and nine moderately obstructed) with the aim to establish diagnostic value. Because breath volume and frequenc...

  10. Corrosion resistance of grouted post-tensioning systems : [summary].

    Science.gov (United States)

    2013-08-01

    The increased popularity of post-tensioned bridge construction in the United States has led to concerns about corrosion and its impact on the life cycle of these bridges. Although the vast majority of post-tensioned bridges in the United States have ...

  11. Development of hybrid lifecycle cost estimating tool (HLCET) for manufacturing influenced design tradeoff

    Science.gov (United States)

    Sirirojvisuth, Apinut

    In complex aerospace system design, making an effective design decision requires multidisciplinary knowledge from both product and process perspectives. Integrating manufacturing considerations into the design process is most valuable during the early design stages since designers have more freedom to integrate new ideas when changes are relatively inexpensive in terms of time and effort. Several metrics related to manufacturability are cost, time, and manufacturing readiness level (MRL). Yet, there is a lack of structured methodology that quantifies how changes in the design decisions impact these metrics. As a result, a new set of integrated cost analysis tools are proposed in this study to quantify the impacts. Equally important is the capability to integrate this new cost tool into the existing design methodologies without sacrificing agility and flexibility required during the early design phases. To demonstrate the applicability of this concept, a ModelCenter environment is used to develop software architecture that represents Integrated Product and Process Development (IPPD) methodology used in several aerospace systems designs. The environment seamlessly integrates product and process analysis tools and makes effective transition from one design phase to the other while retaining knowledge gained a priori. Then, an advanced cost estimating tool called Hybrid Lifecycle Cost Estimating Tool (HLCET), a hybrid combination of weight-, process-, and activity-based estimating techniques, is integrated with the design framework. A new weight-based lifecycle cost model is created based on Tailored Cost Model (TCM) equations [3]. This lifecycle cost tool estimates the program cost based on vehicle component weights and programmatic assumptions. Additional high fidelity cost tools like process-based and activity-based cost analysis methods can be used to modify the baseline TCM result as more knowledge is accumulated over design iterations. Therefore, with this

  12. A new hybrid support vector machine–wavelet transform approach for estimation of horizontal global solar radiation

    International Nuclear Information System (INIS)

    Mohammadi, Kasra; Shamshirband, Shahaboddin; Tong, Chong Wen; Arif, Muhammad; Petković, Dalibor; Ch, Sudheer

    2015-01-01

    Highlights: • Horizontal global solar radiation (HGSR) is predicted based on a new hybrid approach. • Support Vector Machines and Wavelet Transform algorithm (SVM–WT) are combined. • Different sets of meteorological elements are used to predict HGSR. • The precision of SVM–WT is assessed thoroughly against ANN, GP and ARMA. • SVM–WT would be an appealing approach to predict HGSR and outperforms others. - Abstract: In this paper, a new hybrid approach by combining the Support Vector Machine (SVM) with Wavelet Transform (WT) algorithm is developed to predict horizontal global solar radiation. The predictions are conducted on both daily and monthly mean scales for an Iranian coastal city. The proposed SVM–WT method is compared against other existing techniques to demonstrate its efficiency and viability. Three different sets of parameters are served as inputs to establish three models. The results indicate that the model using relative sunshine duration, difference between air temperatures, relative humidity, average temperature and extraterrestrial solar radiation as inputs shows higher performance than other models. The statistical analysis demonstrates that SVM–WT approach enjoys very good performance and outperforms other approaches. For the best SVM–WT model, the obtained statistical indicators of mean absolute percentage error, mean absolute bias error, root mean square error, relative root mean square error and coefficient of determination for daily estimation are 6.9996%, 0.8405 MJ/m 2 , 1.4245 MJ/m 2 , 7.9467% and 0.9086, respectively. Also, for monthly mean estimation the values are 3.2601%, 0.5104 MJ/m 2 , 0.6618 MJ/m 2 , 3.6935% and 0.9742, respectively. Based upon relative percentage error, for the best SVM–WT model, 88.70% of daily predictions fall within the acceptable range of −10% to +10%

  13. Job-related tension, self-esteem and psychological distress in rehabilitation professionals.

    Science.gov (United States)

    Flett, R; Biggs, H; Alpass, F

    1995-06-01

    We examined perceptions of job-related tension among a non-random sample of 52 New Zealand rehabilitation service providers. We considered the relations between job tension and psychological distress and the extent to which feelings of self-esteem moderated this relationship. Major findings are that (a) there is a consistent positive relationship between job tension and general psychological distress; (b) there is a consistent negative relationship between self-esteem and both job tension and general distress; (c) self-esteem moderates the effect of job tension on general distress in that high levels of job tension were associated with increases in psychological distress among respondents with low self-esteem while among respondents with high-self esteem, job-related tension had little negative impact on feelings of psychological distress. Despite a number of limitations, the findings have a number of important implications for professional functioning among rehabilitation service providers and highlight the need for appropriate staff development and training initiatives which focus specifically on service provider wellbeing.

  14. Pendent_Drop: An ImageJ Plugin to Measure the Surface Tension from an Image of a Pendent Drop

    Directory of Open Access Journals (Sweden)

    Adrian Daerr

    2016-01-01

    Full Text Available The pendent drop method for surface tension measurement consists in analysing the shape of an axisymmetric drop hanging from a capillary tube. This software is an add-on for the public domain image processing software ImageJ which matches a theoretical profile to the contour of a pendent drop, either interactively or by automatically minimising the mismatch. It provides an estimate of the surface tension, drop volume and surface area from the best matching parameters. It can be used in a headless setup. It is hosted on http://fiji.sc/List_of_update_sites with the source code on https://github.com/adaerr/pendent-drop

  15. Hybrid Cubature Kalman filtering for identifying nonlinear models from sampled recording: Estimation of neuronal dynamics.

    Science.gov (United States)

    Madi, Mahmoud K; Karameh, Fadi N

    2017-01-01

    Kalman filtering methods have long been regarded as efficient adaptive Bayesian techniques for estimating hidden states in models of linear dynamical systems under Gaussian uncertainty. Recent advents of the Cubature Kalman filter (CKF) have extended this efficient estimation property to nonlinear systems, and also to hybrid nonlinear problems where by the processes are continuous and the observations are discrete (continuous-discrete CD-CKF). Employing CKF techniques, therefore, carries high promise for modeling many biological phenomena where the underlying processes exhibit inherently nonlinear, continuous, and noisy dynamics and the associated measurements are uncertain and time-sampled. This paper investigates the performance of cubature filtering (CKF and CD-CKF) in two flagship problems arising in the field of neuroscience upon relating brain functionality to aggregate neurophysiological recordings: (i) estimation of the firing dynamics and the neural circuit model parameters from electric potentials (EP) observations, and (ii) estimation of the hemodynamic model parameters and the underlying neural drive from BOLD (fMRI) signals. First, in simulated neural circuit models, estimation accuracy was investigated under varying levels of observation noise (SNR), process noise structures, and observation sampling intervals (dt). When compared to the CKF, the CD-CKF consistently exhibited better accuracy for a given SNR, sharp accuracy increase with higher SNR, and persistent error reduction with smaller dt. Remarkably, CD-CKF accuracy shows only a mild deterioration for non-Gaussian process noise, specifically with Poisson noise, a commonly assumed form of background fluctuations in neuronal systems. Second, in simulated hemodynamic models, parametric estimates were consistently improved under CD-CKF. Critically, time-localization of the underlying neural drive, a determinant factor in fMRI-based functional connectivity studies, was significantly more accurate

  16. Hybrid Cubature Kalman filtering for identifying nonlinear models from sampled recording: Estimation of neuronal dynamics

    Science.gov (United States)

    2017-01-01

    Kalman filtering methods have long been regarded as efficient adaptive Bayesian techniques for estimating hidden states in models of linear dynamical systems under Gaussian uncertainty. Recent advents of the Cubature Kalman filter (CKF) have extended this efficient estimation property to nonlinear systems, and also to hybrid nonlinear problems where by the processes are continuous and the observations are discrete (continuous-discrete CD-CKF). Employing CKF techniques, therefore, carries high promise for modeling many biological phenomena where the underlying processes exhibit inherently nonlinear, continuous, and noisy dynamics and the associated measurements are uncertain and time-sampled. This paper investigates the performance of cubature filtering (CKF and CD-CKF) in two flagship problems arising in the field of neuroscience upon relating brain functionality to aggregate neurophysiological recordings: (i) estimation of the firing dynamics and the neural circuit model parameters from electric potentials (EP) observations, and (ii) estimation of the hemodynamic model parameters and the underlying neural drive from BOLD (fMRI) signals. First, in simulated neural circuit models, estimation accuracy was investigated under varying levels of observation noise (SNR), process noise structures, and observation sampling intervals (dt). When compared to the CKF, the CD-CKF consistently exhibited better accuracy for a given SNR, sharp accuracy increase with higher SNR, and persistent error reduction with smaller dt. Remarkably, CD-CKF accuracy shows only a mild deterioration for non-Gaussian process noise, specifically with Poisson noise, a commonly assumed form of background fluctuations in neuronal systems. Second, in simulated hemodynamic models, parametric estimates were consistently improved under CD-CKF. Critically, time-localization of the underlying neural drive, a determinant factor in fMRI-based functional connectivity studies, was significantly more accurate

  17. Tensioned Fabric Structures with Surface in the Form of Chen-Gackstatter

    Directory of Open Access Journals (Sweden)

    Yee Hooi Min

    2016-01-01

    Full Text Available Form-finding has to be carried out for tensioned fabric structure in order to determine the initial equilibrium shape under prescribed support condition and prestress pattern. Tensioned fabric structures are normally designed to be in the form of equal tensioned surface. Tensioned fabric structure is highly suited to be used for realizing surfaces of complex or new forms. However, research study on a new form as a tensioned fabric structure has not attracted much attention. Another source of inspiration minimal surface which could be adopted as form for tensioned fabric structure is very crucial. The aim of this study is to propose initial equilibrium shape of tensioned fabric structures in the form of Chen-Gackstatter. Computational form-finding using nonlinear analysis method is used to determine the Chen-Gackstatter form of uniformly stressed surfaces. A tensioned fabric structure must curve equally in opposite directions to give the resulting surface a three dimensional stability. In an anticlastic doubly curved surface, the sum of all positive and all negative curvatures is zero. This study provides an alternative choice for structural designer to consider the Chen-Gackstatter applied in tensioned fabric structures. The results on factors affecting initial equilibrium shape can serve as a reference for proper selection of surface parameter for achieving a structurally viable surface.

  18. Use of local and global limit load solutions for plates with surface cracks under tension

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Y. [British Energy Generation Ltd, Barnett Way, Bamwood, Gloucester GL4 3RS (United Kingdom)], E-mail: yuebao.lei@british-energy.com

    2007-09-15

    Some available experimental results for the ductile failure of plates with surface cracks under tension are reviewed. The response of crack driving force, J, and the ligament strain near the local and global limit loads are investigated by performing elastic-perfectly plastic finite element (FE) analysis of a plate with a semi-elliptical crack under tension. The results show that a ligament may survive until the global collapse load is reached when the average ligament strain at the global collapse load, which depends on the uniaxial strain corresponding to the flow stress of the material and the crack geometry, is less than the true fracture strain of the material obtained from uniaxial tension tests. The FE analysis shows that ligament yielding corresponding to the local limit load has little effect on J and the average ligament strain, whereas approach to global collapse corresponds to a sharp increase in both J and the average ligament strain. The prediction of the FE value of J using the reference stress method shows that the global limit load is more relevant to J-estimation than the local one.

  19. Use of local and global limit load solutions for plates with surface cracks under tension

    International Nuclear Information System (INIS)

    Lei, Y.

    2007-01-01

    Some available experimental results for the ductile failure of plates with surface cracks under tension are reviewed. The response of crack driving force, J, and the ligament strain near the local and global limit loads are investigated by performing elastic-perfectly plastic finite element (FE) analysis of a plate with a semi-elliptical crack under tension. The results show that a ligament may survive until the global collapse load is reached when the average ligament strain at the global collapse load, which depends on the uniaxial strain corresponding to the flow stress of the material and the crack geometry, is less than the true fracture strain of the material obtained from uniaxial tension tests. The FE analysis shows that ligament yielding corresponding to the local limit load has little effect on J and the average ligament strain, whereas approach to global collapse corresponds to a sharp increase in both J and the average ligament strain. The prediction of the FE value of J using the reference stress method shows that the global limit load is more relevant to J-estimation than the local one

  20. Inclusion and Participation: Working with the Tensions

    Directory of Open Access Journals (Sweden)

    Gideon Calder

    2011-12-01

    Full Text Available Democracy is crucially about inclusion: a theory of democracy must account for who is to be included in the democratic process, how, and on what terms. Inclusion, if conceived democratically, is fraught with tensions. This article identifies three such tensions, arising respectively in: (i the inauguration of the democratic public; (ii enabling equal participation; and (iii the relationship between instrumental and non-instrumental accounts of democracy’s value. In each case, I argue, rather than seeking somehow to dissolve or avoid such tensions, theories of democracy should allow us to live with their implications reflexively: to work with them. Such tensions are counter-democratic to the extent that they derail what Nancy Fraser calls “participatory parity,” under which citizens count as “full partners in social interaction.” But the extent to which they do this is not itself dependent on points of paradox in the very idea of inclusion. Such parity relies on complex factors, social and economic, which democratic institutions and procedures will not by themselves address. To achieve full democratic inclusion we must already have addressed such factors; no account of democracy itself, however finely-tuned, will do this.

  1. Hybrid vehicle assessment. Phase 1: Petroleum savings analysis

    Science.gov (United States)

    Levin, R.; Liddle, S.; Deshpande, G.; Trummel, M.; Vivian, H. C.

    1984-01-01

    The results of a comprehensive analysis of near term electric hybrid vehicles are presented, with emphasis on their potential to save significant amounts of petroleum on a national scale in the 1990s. Performance requirements and expected annual usage patterns of these vehicles are first modeled. The projected U.S. fleet composition is estimated, and conceptual hybrid vehicle designs are conceived and analyzed for petroleum use when driven in the expected annual patterns. These petroleum consumption estimates are then compared to similar estimates for projected 1990 conventional vehicles having the same performance and driven in the same patterns. Results are presented in the form of three utility functions and comparisons of sevral conceptual designs are made. The Hybrid Vehicle (HV) design and assessment techniques are discussed and a general method is explained for selecting the optimum energy management strategy for any vehicle mission battery combination. Conclusions and recommendations are presented, and development recommendations are identified.

  2. 33 CFR 147.809 - Mars Tension Leg Platform safety zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Mars Tension Leg Platform safety... SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.809 Mars Tension Leg Platform safety zone. (a) Description. The Mars Tension Leg Platform (Mars TLP) is located at position 28°10′10.29...

  3. Short-Time Structural Stability of Compressible Vortex Sheets with Surface Tension

    Science.gov (United States)

    Stevens, Ben

    2016-11-01

    Assume we start with an initial vortex-sheet configuration which consists of two inviscid fluids with density bounded below flowing smoothly past each other, where a strictly positive fixed coefficient of surface tension produces a surface tension force across the common interface, balanced by the pressure jump. We model the fluids by the compressible Euler equations in three space dimensions with a very general equation of state relating the pressure, entropy and density such that the sound speed is positive. We prove that, for a short time, there exists a unique solution of the equations with the same structure. The mathematical approach consists of introducing a carefully chosen artificial viscosity-type regularisation which allows one to linearise the system so as to obtain a collection of transport equations for the entropy, pressure and curl together with a parabolic-type equation for the velocity which becomes fairly standard after rotating the velocity according to the interface normal. We prove a high order energy estimate for the non-linear equations that is independent of the artificial viscosity parameter which allows us to send it to zero. This approach loosely follows that introduced by Shkoller et al. in the setting of a compressible liquid-vacuum interface. Although already considered by Coutand et al. [10] and Lindblad [17], we also make some brief comments on the case of a compressible liquid-vacuum interface, which is obtained from the vortex sheets problem by replacing one of the fluids by vacuum, where it is possible to obtain a structural stability result even without surface tension.

  4. Fatigue Life Analysis of Tapered Hybrid Composite Flexbeams

    Science.gov (United States)

    Murri, Gretchen B.; Schaff, Jeffery R.; Dobyns, Alan L.

    2002-01-01

    Nonlinear-tapered flexbeam laminates from a full-size composite helicopter rotor hub flexbeam were tested under combined constant axial tension and cyclic bending loads. The two different graphite/glass hybrid configurations tested under cyclic loading failed by delamination in the tapered region. A 2-D finite element model was developed which closely approximated the flexbeam geometry, boundary conditions, and loading. The analysis results from two geometrically nonlinear finite element codes, ANSYS and ABAQUS, are presented and compared. Strain energy release rates (G) obtained from the above codes using the virtual crack closure technique (VCCT) at a resin crack location in the flexbeams are presented for both hybrid material types. These results compare well with each other and suggest that the initial delamination growth from the resin crack toward the thick region of the flexbeam is strongly mode II. The peak calculated G values were used with material characterization data to calculate fatigue life curves and compared with test data. A curve relating maximum surface strain to number of loading cycles at delamination onset compared reasonably well with the test results.

  5. Tension bulla: a cause of reversible pulmonary hypertension.

    Science.gov (United States)

    Waxman, Michael J; Waxman, Jacob D; Forman, John M

    2015-01-01

    A tension pneumothorax represents a medical emergency warranting urgent diagnosis and treatment. A rapidly expanding bulla may resemble the same clinical presentation but requires an entirely different treatment. A 53-year-old woman presented with increasing shortness of breath and her physical examination and chest x-ray were interpreted as showing a tension pneumothorax. A chest tube was placed which did not resolve the process. Placement of a second chest tube was likewise unsuccessful. A chest CT was then performed and was interpreted as showing an unresolved tension pneumothorax, despite seemingly adequate placement of the 2 chest tubes. Further review of the CT showed the border of a giant bulla and a tentative diagnosis was made of a rapidly expanding bulla with tension physiology. Echocardiogram revealed significant pulmonary hypertension. The bulla was surgically excised, the patient had marked improvement in her clinical symptoms and signs, and echocardiographic follow-up showed complete resolution of the pulmonary hypertension.

  6. Leadership. Using Creative Tension.

    Science.gov (United States)

    Cook, David L.

    1986-01-01

    Leadership involves maintaining a balance of the variables which comprise leadership. Love and fear, types of power, success and effectiveness, and driving and restraining forces are discussed as sources of the creative tension a leader uses to influence others. (MT)

  7. The application of computational thermodynamics and a numerical model for the determination of surface tension and Gibbs-Thomson coefficient of aluminum based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jacome, Paulo A.D.; Landim, Mariana C. [Department of Mechanical Engineering, Fluminense Federal University, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil); Garcia, Amauri, E-mail: amaurig@fem.unicamp.br [Department of Materials Engineering, University of Campinas, UNICAMP, PO Box 6122, 13083-970 Campinas, SP (Brazil); Furtado, Alexandre F.; Ferreira, Ivaldo L. [Department of Mechanical Engineering, Fluminense Federal University, Av. dos Trabalhadores, 420-27255-125 Volta Redonda, RJ (Brazil)

    2011-08-20

    Highlights: {yields} Surface tension and the Gibbs-Thomson coefficient are computed for Al-based alloys. {yields} Butler's scheme and ThermoCalc are used to compute the thermophysical properties. {yields} Predictive cell/dendrite growth models depend on accurate thermophysical properties. {yields} Mechanical properties can be related to the microstructural cell/dendrite spacing. - Abstract: In this paper, a solution for Butler's formulation is presented permitting the surface tension and the Gibbs-Thomson coefficient of Al-based binary alloys to be determined. The importance of Gibbs-Thomson coefficient for binary alloys is related to the reliability of predictions furnished by predictive cellular and dendritic growth models and of numerical computations of solidification thermal variables, which will be strongly dependent on the thermophysical properties assumed for the calculations. A numerical model based on Powell hybrid algorithm and a finite difference Jacobian approximation was coupled to a specific interface of a computational thermodynamics software in order to assess the excess Gibbs energy of the liquid phase, permitting the surface tension and Gibbs-Thomson coefficient for Al-Fe, Al-Ni, Al-Cu and Al-Si hypoeutectic alloys to be calculated. The computed results are presented as a function of the alloy composition.

  8. Influence of reinforcement type on the mechanical behavior and fire response of hybrid composites and sandwich structures

    Science.gov (United States)

    Giancaspro, James William

    Lightweight composites and structural sandwich panels are commonly used in marine and aerospace applications. Using carbon, glass, and a host of other high strength fiber types, a broad range of laminate composites and sandwich panels can be developed. Hybrid composites can be constructed by laminating multiple layers of varying fiber types while sandwich panels are manufactured by laminating rigid fiber facings onto a lightweight core. However, the lack of fire resistance of the polymers used for the fabrication remains a very important problem. The research presented in this dissertation deals with an inorganic matrix (Geopolymer) that can be used to manufacture laminate composites and sandwich panels that are resistant up to 1000°C. This dissertation deals with the influence of fiber type on the mechanical behavior and the fire response of hybrid composites and sandwich structures manufactured using this resin. The results are categorized into the following distinct studies. (i) High strength carbon fibers were combined with low cost E-glass fibers to obtain hybrid laminate composites that are both economical and strong. The E-glass fabrics were used as a core while the carbon fibers were placed on the tension face and on both tension and compression faces. (ii) Structural sandwich beams were developed by laminating various types of reinforcement onto the tension and compression faces of balsa wood cores. The flexural behavior of the beams was then analyzed and compared to beams reinforced with organic composite. The effect of core density was evaluated using oak beams reinforced with inorganic composite. (iii) To measure the fire response, balsa wood sandwich panels were manufactured using a thin layer of a fire-resistant paste to serve for fire protection. Seventeen sandwich panels were fabricated and tested to measure the heat release rates and smoke-generating characteristics. The results indicate that Geopolymer can be effectively used to fabricate both

  9. Optimizing hybrid spreading in metapopulations.

    Science.gov (United States)

    Zhang, Changwang; Zhou, Shi; Miller, Joel C; Cox, Ingemar J; Chain, Benjamin M

    2015-04-29

    Epidemic spreading phenomena are ubiquitous in nature and society. Examples include the spreading of diseases, information, and computer viruses. Epidemics can spread by local spreading, where infected nodes can only infect a limited set of direct target nodes and global spreading, where an infected node can infect every other node. In reality, many epidemics spread using a hybrid mixture of both types of spreading. In this study we develop a theoretical framework for studying hybrid epidemics, and examine the optimum balance between spreading mechanisms in terms of achieving the maximum outbreak size. We show the existence of critically hybrid epidemics where neither spreading mechanism alone can cause a noticeable spread but a combination of the two spreading mechanisms would produce an enormous outbreak. Our results provide new strategies for maximising beneficial epidemics and estimating the worst outcome of damaging hybrid epidemics.

  10. Surface tension of H2O and D2O

    International Nuclear Information System (INIS)

    Vargaftik, N.B.; Voljak, L.D.; Volkov, B.N.

    1975-01-01

    There is a great number of works on surface tension of clean water (H 2 O) at temperatures up to 100 deg C and very few above the boiling point. Works on surface tension of heavy water (D 2 O) are insufficient. A review of works on surface tension of both kinds of water is given

  11. Strain Capacity of Reinforced Concrete Members Subjected to Uniaxial Tension

    DEFF Research Database (Denmark)

    Hagsten, Lars German; Rasmussen, Annette Beedholm; Fisker, Jakob

    2017-01-01

    The aim of this paper is to set up a method to determine the strain capacity of tension bars of reinforced concrete (RC) subjected to pure tension. Due to the interaction between reinforcement and concrete and due to the presence of cracks, the stresses in both reinforcement and concrete...... are varying along the length of the tension bar. The strain capacity of the tension bar is seen as the average strain in the reinforcement at the load level corresponding to the ultimate stress capacity of the reinforcement at the cracks. The result of the approach is in overall good agreement when comparing...

  12. Hybrid Charmonium and the p-n Puzzle

    International Nuclear Information System (INIS)

    Kisslinger, L.S.; Parno, D.; Riordan, S.

    2008-01-01

    Using the method of QCD sum rules, we estimate the energy of the lowest hybrid charmonium state, and find it to be at the energy of the Ψ (2S) state, about 600 MeV above the J/Ψ(1S) state. Since our solution is not consistent with a pure hybrid at this energy, we conclude that the Ψ (2S) state is probably an admixed cc - and hybrid cc - g state. From this conjecture, we find a possible explanation of the famous ρ-p puzzle.

  13. Choroidal Excavation in Eye with Normal Tension Glaucoma

    Directory of Open Access Journals (Sweden)

    Kazunobu Asao

    2014-05-01

    Full Text Available Purpose: To report the case of an eye with normal tension glaucoma and a choroidal excavation. Methods: This is an observational case report. Results: A 59-year-old woman with normal tension glaucoma had a choroidal excavation in the left eye. Her best-corrected visual acuity and intraocular pressure were within normal limits and had been stable for 5 years. Fundus examination showed a small white lesion inferior to the macula and a nerve fiber layer defect at the inferior edge of the optic disc. Humphrey Field Analyzer (HFA showed visual field defects corresponding to the nerve fiber layer defect with C30-2, and a central scotoma superior to the macula with C10-2. Optical coherence tomography (OCT showed a 150-µm deep choroidal excavation. Disruptions of the IS/OS line were detected only in the area inferior to the choroidal excavation. During the 5 months of follow-up, her best-corrected visual acuity remained at 1.0 and the IOP ranged from 12 to 14 mm Hg in the left eye. The fundus and OCT images did not deteriorate and the choroidal excavation did not enlarge. Conclusions: The disruption of the inner/outer segment (IS/OS line was detected only at the area surrounding the choroidal excavation. OCT examinations are useful in assessing the area of the residual IS/OS line, and HFA can be used to estimate the residual central visual field.

  14. Tension in the recent Type Ia supernovae datasets

    International Nuclear Information System (INIS)

    Wei, Hao

    2010-01-01

    In the present work, we investigate the tension in the recent Type Ia supernovae (SNIa) datasets Constitution and Union. We show that they are in tension not only with the observations of the cosmic microwave background (CMB) anisotropy and the baryon acoustic oscillations (BAO), but also with other SNIa datasets such as Davis and SNLS. Then, we find the main sources responsible for the tension. Further, we make this more robust by employing the method of random truncation. Based on the results of this work, we suggest two truncated versions of the Union and Constitution datasets, namely the UnionT and ConstitutionT SNIa samples, whose behaviors are more regular.

  15. Study of homogeneous bubble nucleation in liquid carbon dioxide by a hybrid approach combining molecular dynamics simulation and density gradient theory

    Science.gov (United States)

    Langenbach, K.; Heilig, M.; Horsch, M.; Hasse, H.

    2018-03-01

    A new method for predicting homogeneous bubble nucleation rates of pure compounds from vapor-liquid equilibrium (VLE) data is presented. It combines molecular dynamics simulation on the one side with density gradient theory using an equation of state (EOS) on the other. The new method is applied here to predict bubble nucleation rates in metastable liquid carbon dioxide (CO2). The molecular model of CO2 is taken from previous work of our group. PC-SAFT is used as an EOS. The consistency between the molecular model and the EOS is achieved by adjusting the PC-SAFT parameters to VLE data obtained from the molecular model. The influence parameter of density gradient theory is fitted to the surface tension of the molecular model. Massively parallel molecular dynamics simulations are performed close to the spinodal to compute bubble nucleation rates. From these simulations, the kinetic prefactor of the hybrid nucleation theory is estimated, whereas the nucleation barrier is calculated from density gradient theory. This enables the extrapolation of molecular simulation data to the whole metastable range including technically relevant densities. The results are tested against available experimental data and found to be in good agreement. The new method does not suffer from typical deficiencies of classical nucleation theory concerning the thermodynamic barrier at the spinodal and the bubble size dependence of surface tension, which is typically neglected in classical nucleation theory. In addition, the density in the center of critical bubbles and their surface tension is determined as a function of their radius. The usual linear Tolman correction to the capillarity approximation is found to be invalid.

  16. Study of homogeneous bubble nucleation in liquid carbon dioxide by a hybrid approach combining molecular dynamics simulation and density gradient theory.

    Science.gov (United States)

    Langenbach, K; Heilig, M; Horsch, M; Hasse, H

    2018-03-28

    A new method for predicting homogeneous bubble nucleation rates of pure compounds from vapor-liquid equilibrium (VLE) data is presented. It combines molecular dynamics simulation on the one side with density gradient theory using an equation of state (EOS) on the other. The new method is applied here to predict bubble nucleation rates in metastable liquid carbon dioxide (CO 2 ). The molecular model of CO 2 is taken from previous work of our group. PC-SAFT is used as an EOS. The consistency between the molecular model and the EOS is achieved by adjusting the PC-SAFT parameters to VLE data obtained from the molecular model. The influence parameter of density gradient theory is fitted to the surface tension of the molecular model. Massively parallel molecular dynamics simulations are performed close to the spinodal to compute bubble nucleation rates. From these simulations, the kinetic prefactor of the hybrid nucleation theory is estimated, whereas the nucleation barrier is calculated from density gradient theory. This enables the extrapolation of molecular simulation data to the whole metastable range including technically relevant densities. The results are tested against available experimental data and found to be in good agreement. The new method does not suffer from typical deficiencies of classical nucleation theory concerning the thermodynamic barrier at the spinodal and the bubble size dependence of surface tension, which is typically neglected in classical nucleation theory. In addition, the density in the center of critical bubbles and their surface tension is determined as a function of their radius. The usual linear Tolman correction to the capillarity approximation is found to be invalid.

  17. Tensions in implementing the “energy-conservation/carbon-reduction” policy in Taiwanese culture

    International Nuclear Information System (INIS)

    Chiu, Mei-Shiu

    2013-01-01

    The aim of this study is to investigate the Taiwanese public's perceptions of tensions between the implementation of an energy policy and the practice of traditional culture. The energy policy calls for public actions to conserve energy and reduce carbon emissions. The research participants are 94 people, selected by balancing sexes, ages, and residential areas, from a wide range of vocations. The research data were collected by semi-structured interview with the participants individually. Interview questions were designed to elicit the participants' constructs, beliefs, behaviours, and tensions in relation to energy policy and traditional culture. Data analysis was performed based on a qualitative methodology by the procedure of open coding, theme finding, constant comparison, and theory generation. The analysis identifies four tensions: (1) tensions in knowledge bases between energy conservation and carbon reduction, (2) tensions in lifestyles between having and being, (3) tensions in social systems between authority and conformity, and (4) tensions in creation boundaries between technology and nature. The themes underlying the four tensions are uncertainty, pleasure, power, and control, respectively. Solutions to the four tensions may include practical knowledge, pragmatic idealism, hierarchical collaboration, and sustainable innovation. - Highlights: ► Tensions occur between energy policy and traditional culture. ► Tensions occur in knowledge, life, society, and creation in Taiwan. ► The themes of the four tensions are uncertainty, pleasure, power, and control

  18. Evaluation of J and CTOD (Crack Tip Opening Displacement) fracture parameters for pipeline steels using Single Edge Notch Tension SE(T) specimens

    Energy Technology Data Exchange (ETDEWEB)

    Paredes Tobar, Lenin Marcelo; Ruggieri, Claudio [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Naval e Oceanica

    2009-12-19

    This work presents an evaluation procedure to determine the elastic-plastic J-integral and CTOD for pin-loaded and clamped single edge notch tension (SE(T)) specimens based upon the eta-method. The primary objective is to derive estimation equations applicable to determine J and CTOD fracture parameters for a wide range of a/W-ratios and material flow properties. Very detailed non-linear finite element analyses for plane-strain and full-thickness, 3-D models provide the evolution of load with increased crack mouth opening displacement which is required for the estimation procedure. The present analyses, when taken together with previous studies provide a fairly extensive body of results which serve to determine parameters J and CTOD for different materials using tension specimens with varying geometries. (author)

  19. Rein tension acceptance in young horses in a voluntary test situation

    DEFF Research Database (Denmark)

    Christensen, Janne Winther; zharkikh, T.L.; Antoine, A.

    2011-01-01

    Reasons for performing the study: During riding, horses are frequently exposed to pressure from the rider, e.g. through the bit and reins, but few studies have investigated at which point rein tension becomes uncomfortable for the horse. Objectives: To investigate how much rein tension young...... inexperienced horses are willing to accept in order to obtain a food reward; whether the tension acceptance changes during 3 consecutive test days; and whether rein tension correlates with the expression of conflict behaviour and heart rate. Hypotheses: Pressure-naïve horses will apply only little rein tension...... in the first voluntary trial, but their acceptance will gradually increase. High levels of rein tension will lead to expression of conflict behaviour and increases in heart rate. Methods: Fifteen 2-year-old, bridle-naïve mares were encouraged to stretch their head forward (across a 0.95 m high metal bar...

  20. Tensions in the Parent and Adult Child Relationship: Links to Solidarity and Ambivalence

    Science.gov (United States)

    Birditt, Kira S.; Miller, Laura M.; Fingerman, Karen L.; Lefkowitz, Eva S.

    2009-01-01

    Tensions are normative in the parent and adult child relationship, but there is little research on the topics that cause the most tension or whether tensions are associated with overall relationship quality. Adult sons and daughters, aged 22 to 49, and their mothers and fathers (N = 158 families, 474 individuals) reported the intensity of different tension topics and relationship quality (solidarity and ambivalence) with one another. Tensions varied between and within families by generation, gender and age of offspring. In comparison to tensions regarding individual issues, tensions regarding the relationship were associated with lower affective solidarity and greater ambivalence. Findings are consistent with the developmental schism hypothesis, which indicates that parent-child tensions are common and are the result of discrepancies in developmental needs which vary by generation, gender, and age. PMID:19485648

  1. Estimating Security Betas Using Prior Information Based on Firm Fundamentals

    NARCIS (Netherlands)

    Cosemans, Mathijs; Frehen, Rik; Schotman, Peter; Bauer, Rob

    2016-01-01

    We propose a hybrid approach for estimating beta that shrinks rolling window estimates toward firm-specific priors motivated by economic theory. Our method yields superior forecasts of beta that have important practical implications. First, unlike standard rolling window betas, hybrid betas carry a

  2. Hybrid Adaptive Observer for a Brushless DC Motor

    DEFF Research Database (Denmark)

    Niemczyk, Piotr; Porchez, Thomas; Bendtsen, Jan Dimon

    2008-01-01

    A novel hybrid adaptive observer for Brushless DC Motors (BLDCM) is presented. It uses two current measurements of BLDCM phases to estimate the angle and the speed of the rotor. The observer is designed on the basis of a hybrid model, which is also presented in this paper. The parameters...

  3. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T

    2004-01-01

    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta...

  4. Estimation of Production KWS Maize Hybrids Using Nonlinear Regression

    Directory of Open Access Journals (Sweden)

    Florica MORAR

    2018-06-01

    Full Text Available This article approaches the model of non-linear regression and the method of smallest squares with examples, including calculations for the model of logarithmic function. This required data obtained from a study which involved the observation of the phases of growth and development in KWS maize hybrids in order to analyze the influence of the MMB quality indicator on grain production per hectare.

  5. Cellular control of connective tissue matrix tension.

    Science.gov (United States)

    Langevin, Helene M; Nedergaard, Maiken; Howe, Alan K

    2013-08-01

    The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function, and cancer. Copyright © 2013 Wiley Periodicals, Inc.

  6. Simultaneous Estimation of Model State Variables and Observation and Forecast Biases Using a Two-Stage Hybrid Kalman Filter

    Science.gov (United States)

    Pauwels, V. R. N.; DeLannoy, G. J. M.; Hendricks Franssen, H.-J.; Vereecken, H.

    2013-01-01

    In this paper, we present a two-stage hybrid Kalman filter to estimate both observation and forecast bias in hydrologic models, in addition to state variables. The biases are estimated using the discrete Kalman filter, and the state variables using the ensemble Kalman filter. A key issue in this multi-component assimilation scheme is the exact partitioning of the difference between observation and forecasts into state, forecast bias and observation bias updates. Here, the error covariances of the forecast bias and the unbiased states are calculated as constant fractions of the biased state error covariance, and the observation bias error covariance is a function of the observation prediction error covariance. In a series of synthetic experiments, focusing on the assimilation of discharge into a rainfall-runoff model, it is shown that both static and dynamic observation and forecast biases can be successfully estimated. The results indicate a strong improvement in the estimation of the state variables and resulting discharge as opposed to the use of a bias-unaware ensemble Kalman filter. Furthermore, minimal code modification in existing data assimilation software is needed to implement the method. The results suggest that a better performance of data assimilation methods should be possible if both forecast and observation biases are taken into account.

  7. Simultaneous estimation of model state variables and observation and forecast biases using a two-stage hybrid Kalman filter

    Directory of Open Access Journals (Sweden)

    V. R. N. Pauwels

    2013-09-01

    Full Text Available In this paper, we present a two-stage hybrid Kalman filter to estimate both observation and forecast bias in hydrologic models, in addition to state variables. The biases are estimated using the discrete Kalman filter, and the state variables using the ensemble Kalman filter. A key issue in this multi-component assimilation scheme is the exact partitioning of the difference between observation and forecasts into state, forecast bias and observation bias updates. Here, the error covariances of the forecast bias and the unbiased states are calculated as constant fractions of the biased state error covariance, and the observation bias error covariance is a function of the observation prediction error covariance. In a series of synthetic experiments, focusing on the assimilation of discharge into a rainfall-runoff model, it is shown that both static and dynamic observation and forecast biases can be successfully estimated. The results indicate a strong improvement in the estimation of the state variables and resulting discharge as opposed to the use of a bias-unaware ensemble Kalman filter. Furthermore, minimal code modification in existing data assimilation software is needed to implement the method. The results suggest that a better performance of data assimilation methods should be possible if both forecast and observation biases are taken into account.

  8. On the efficiency of the hybrid and the exact second-order sampling formulations of the EnKF: a reality-inspired 3-D test case for estimating biodegradation rates of chlorinated hydrocarbons at the port of Rotterdam

    KAUST Repository

    El Gharamti, Mohamad

    2016-11-15

    This study considers the assimilation problem of subsurface contaminants at the port of Rotterdam in the Netherlands. It involves the estimation of solute concentrations and biodegradation rates of four different chlorinated solvents. We focus on assessing the efficiency of an adaptive hybrid ensemble Kalman filter and optimal interpolation (EnKF-OI) and the exact second-order sampling formulation (EnKFESOS) for mitigating the undersampling of the estimation and observation errors covariances, respectively. A multi-dimensional and multi-species reactive transport model is coupled to simulate the migration of contaminants within a Pleistocene aquifer layer located around 25 m below mean sea level. The biodegradation chain of chlorinated hydrocarbons starting from tetrachloroethene and ending with vinyl chloride is modeled under anaerobic environmental conditions for 5 decades. Yearly pseudo-concentration data are used to condition the forecast concentration and degradation rates in the presence of model and observational errors. Assimilation results demonstrate the robustness of the hybrid EnKF-OI, for accurately calibrating the uncertain biodegradation rates. When implemented serially, the adaptive hybrid EnKF-OI scheme efficiently adjusts the weights of the involved covariances for each individual measurement. The EnKFESOS is shown to maintain the parameter ensemble spread much better leading to more robust estimates of the states and parameters. On average, a well tuned hybrid EnKF-OI and the EnKFESOS respectively suggest around 48 and 21 % improved concentration estimates, as well as around 70 and 23 % improved anaerobic degradation rates, over the standard EnKF. Incorporating large uncertainties in the flow model degrades the accuracy of the estimates of all schemes. Given that the performance of the hybrid EnKF-OI depends on the quality of the background statistics, satisfactory results were obtained only when the uncertainty imposed on the background

  9. Exploring the tensions of being and becoming a medical educator.

    Science.gov (United States)

    Sethi, Ahsan; Ajjawi, Rola; McAleer, Sean; Schofield, Susie

    2017-03-23

    Previous studies have identified tensions medical faculty encounter in their roles but not specifically those with a qualification in medical education. It is likely that those with postgraduate qualifications may face additional tensions (i.e., internal or external conflicts or concerns) from differentiation by others, greater responsibilities and translational work against the status quo. This study explores the complex and multi-faceted tensions of educators with qualifications in medical education at various stages in their career. The data described were collected in 2013-14 as part of a larger, three-phase mixed-methods research study employing a constructivist grounded theory analytic approach to understand identity formation among medical educators. The over-arching theoretical framework for the study was Communities of Practice. Thirty-six educators who had undertaken or were undertaking a postgraduate qualification in medical education took part in semi-structured interviews. Participants expressed multiple tensions associated with both becoming and being a healthcare educator. Educational roles had to be juggled with clinical work, challenging their work-life balance. Medical education was regarded as having lower prestige, and therefore pay, than other healthcare career tracks. Medical education is a vast speciality, making it difficult as a generalist to keep up-to-date in all its areas. Interestingly, the graduates with extensive experience in education reported no fears, rather asserting that the qualification gave them job variety. This is the first detailed study exploring the tensions of educators with postgraduate qualifications in medical education. It complements and extends the findings of the previous studies by identifying tensions common as well as specific to active students and graduates. These tensions may lead to detachment, cynicism and a weak sense of identity among healthcare educators. Postgraduate programmes in medical education

  10. Conducting Qualitative Data Analysis: Managing Dynamic Tensions within

    Science.gov (United States)

    Chenail, Ronald J.

    2012-01-01

    In the third of a series of "how-to" essays on conducting qualitative data analysis, Ron Chenail examines the dynamic tensions within the process of qualitative data analysis that qualitative researchers must manage in order to produce credible and creative results. These tensions include (a) the qualities of the data and the qualitative data…

  11. Coupled Interfacial Tension and Phase Behavior Model Based on Micellar Curvatures

    KAUST Repository

    Torrealba, V. A.

    2017-11-08

    This article introduces a consistent and robust model that predicts interfacial tensions for all microemulsion Winsor types and overall compositions. The model incorporates film bending arguments and Huh\\'s equation and is coupled to phase behavior so that simultaneous tuning of both interfacial tension (IFT) and phase behavior is possible. The oil-water interfacial tension and characteristic length are shown to be related to each other through the hydrophilic-lipophilic deviation (HLD). The phase behavior is tied to the micelle curvatures, without the need for using the net average curvature (NAC). The interfacial tension model is related to solubilization ratios in order to introduce a coupled interfacial tension-phase behavior model for all phase environments. The approach predicts two- and three-phase interfacial tensions and phase behavior (i.e., tie lines and tie triangles) for changes in composition and HLD input parameters, such as temperature, pressure, surfactant structure, and oil equivalent alkane carbon number. Comparisons to experimental data show excellent fits and predictive capability.

  12. Estimating security betas using prior information based on firm fundamentals

    NARCIS (Netherlands)

    Cosemans, Mathijs; Frehen, Rik; Schotman, Peter; Bauer, Rob

    We propose a hybrid approach for estimating beta that shrinks rolling window estimates towards firm-specific priors motivated by economic theory. Our method yields superior forecasts of beta that have important practical implications. First, hybrid betas carry a significant price of risk in the

  13. Quantifying the BICEP2-Planck tension over gravitational waves.

    Science.gov (United States)

    Smith, Kendrick M; Dvorkin, Cora; Boyle, Latham; Turok, Neil; Halpern, Mark; Hinshaw, Gary; Gold, Ben

    2014-07-18

    The recent BICEP2 measurement of B-mode polarization in the cosmic microwave background (r = 0.2(-0.05)(+0.07)), a possible indication of primordial gravity waves, appears to be in tension with the upper limit from WMAP (r < 0.13 at 95% C.L.) and Planck (r < 0.11 at 95% C.L.). We carefully quantify the level of tension and show that it is very significant (around 0.1% unlikely) when the observed deficit of large-scale temperature power is taken into account. We show that measurements of TE and EE power spectra in the near future will discriminate between the hypotheses that this tension is either a statistical fluke or a sign of new physics. We also discuss extensions of the standard cosmological model that relieve the tension and some novel ways to constrain them.

  14. Synthesis and mechanical behavior of carbon nanotube-magnesium composites hybridized with nanoparticles of alumina

    International Nuclear Information System (INIS)

    Thakur, Sanjay Kumar; Srivatsan, T.S.; Gupta, Manoj

    2007-01-01

    Carbon nanotubes reinforced magnesium based composites were prepared with diligence and care using the powder metallurgy route coupled with rapid microwave sintering. Nanometer-sized particles of alumina were used to hybridize the carbon nanotubes reinforcement in the magnesium matrix so as to establish the intrinsic influence of hybridization on mechanical behavior of the resultant composite material. The yield strength, tensile strength and strain-to-failure of the carbon nanotubes-magnesium composites were found to increase with the addition of nanometer-sized alumina particles to the composite matrix. Scanning electron microscopy observations of the fracture surfaces of the samples deformed and failed in uniaxial tension revealed the presence of cleavage-like features on the fracture surface indicative of the occurrence of locally brittle fracture mechanism in the composite microstructure

  15. Modeling of surface tension effects in venturi scrubbing

    Science.gov (United States)

    Ott, Robert M.; Wu, Tatsu K. L.; Crowder, Jerry W.

    A modified model of venturi scrubber performance has been developed that addresses two effects of liquid surface tension: its effect on droplet size and its effect on particle penetration into the droplet. The predictions of the model indicate that, in general, collection efficiency increases with a decrease in liquid surface tension, but the range over which this increase is significant depends on the particle size and on the scrubber operating parameters. The predictions further indicate that the increases in collection efficiency are almost totally due to the effect of liquid surface tension on the mean droplet size, and that the collection efficiency is not significantly affected by the ability of the particle to penetrate the droplet.

  16. Hybrid Adaptive Observer for a Brushless DC Motor

    DEFF Research Database (Denmark)

    Niemczyk, Piotr; Porchez, Thomas; Bendtsen, Jan Dimon

    2008-01-01

    A novel hybrid adaptive observer for Brushless DC Motors (BLDCM) is presented. It uses two current measurements of BLDCM phases to estimate the angle and the speed of the rotor. The observer is designed on the basis of a hybrid model, which is also presented in this paper. The parameters of the o...

  17. Rapid detection of chromosome rearrangement in medical diagnostic X-ray workers by using fluorescence in situ hybridization and study on dose estimation

    International Nuclear Information System (INIS)

    Wang Zhiquan; Sun Yuanming; Li Jin

    1998-01-01

    Objective: Biological doses were estimated for medical diagnostic X-ray workers. Methods: Chromosome rearrangements in X-ray workers were analysed by fluorescence in situ hybridization (FISH) with composite whole chromosome paintings number 4 and number 7. Results: The frequency of translocation in medical diagnostic X-ray workers was much higher than that in control group (P<0.01). The biological doses to individual X-ray workers were calculated by their translocation frequency. The translocation frequencies of both FISH and G-banding were in good agreement. Conclusion: The biological doses to X-ray workers are estimated by FISH first when their dosimetry records are not documented

  18. Real-Time Implementation of an Extended Kalman Filter and a PI Observer for State Estimation of Rechargeable Li-Ion Batteries in Hybrid Electric Vehicle Applications—A Case Study

    Directory of Open Access Journals (Sweden)

    Roxana-Elena Tudoroiu

    2018-04-01

    Full Text Available The Li-Ion battery state-of-charge estimation is an essential task in a continuous dynamic automotive industry for large-scale and successful marketing of hybrid electric vehicles. Also, the state-of-charge of any rechargeable battery, regardless of its chemistry, is an essential condition parameter for battery management systems of hybrid electric vehicles. In this study, we share from our accumulated experience in the control system applications field some preliminary results, especially in modeling, control and state estimation techniques. We investigate the design and effectiveness of two state-of-charge estimators, namely an extended Kalman filter and a proportional integral observer, implemented in a real-time MATLAB environment for a particular Li-Ion battery. Definitely, the aim of this work is to find the most suitable estimator in terms of estimation accuracy and robustness to changes in initial conditions (i.e., the initial guess value of battery state-of-charge and changes in process and measurement noise levels. By a rigorous performance analysis of MATLAB simulation results, the potential estimator choice is revealed. The performance comparison can be done visually on similar graphs if the information gathered provides a good insight, otherwise, it can be done statistically based on the calculus of statistic errors, in terms of root mean square error, mean absolute error and mean square error.

  19. Myosin II dynamics are regulated by tension in intercalating cells.

    Science.gov (United States)

    Fernandez-Gonzalez, Rodrigo; Simoes, Sérgio de Matos; Röper, Jens-Christian; Eaton, Suzanne; Zallen, Jennifer A

    2009-11-01

    Axis elongation in Drosophila occurs through polarized cell rearrangements driven by actomyosin contractility. Myosin II promotes neighbor exchange through the contraction of single cell boundaries, while the contraction of myosin II structures spanning multiple pairs of cells leads to rosette formation. Here we show that multicellular actomyosin cables form at a higher frequency than expected by chance, indicating that cable assembly is an active process. Multicellular cables are sites of increased mechanical tension as measured by laser ablation. Fluorescence recovery after photobleaching experiments show that myosin II is stabilized at the cortex in regions of increased tension. Myosin II is recruited in response to an ectopic force and relieving tension leads to a rapid loss of myosin, indicating that tension is necessary and sufficient for cortical myosin localization. These results demonstrate that myosin II dynamics are regulated by tension in a positive feedback loop that leads to multicellular actomyosin cable formation and efficient tissue elongation.

  20. Estimating raw material equivalents on a macro-level: comparison of multi-regional input-output analysis and hybrid LCI-IO.

    Science.gov (United States)

    Schoer, Karl; Wood, Richard; Arto, Iñaki; Weinzettel, Jan

    2013-12-17

    The mass of material consumed by a population has become a useful proxy for measuring environmental pressure. The "raw material equivalents" (RME) metric of material consumption addresses the issue of including the full supply chain (including imports) when calculating national or product level material impacts. The RME calculation suffers from data availability, however, as quantitative data on production practices along the full supply chain (in different regions) is required. Hence, the RME is currently being estimated by three main approaches: (1) assuming domestic technology in foreign economies, (2) utilizing region-specific life-cycle inventories (in a hybrid framework), and (3) utilizing multi-regional input-output (MRIO) analysis to explicitly cover all regions of the supply chain. While the first approach has been shown to give inaccurate results, this paper focuses on the benefits and costs of the latter two approaches. We analyze results from two key (MRIO and hybrid) projects modeling raw material equivalents, adjusting the models in a stepwise manner in order to quantify the effects of individual conceptual elements. We attempt to isolate the MRIO gap, which denotes the quantitative impact of calculating the RME of imports by an MRIO approach instead of the hybrid model, focusing on the RME of EU external trade imports. While, the models give quantitatively similar results, differences become more pronounced when tracking more detailed material flows. We assess the advantages and disadvantages of the two approaches and look forward to ways to further harmonize data and approaches.

  1. Surface tension anomalies in room temperature ionic liquids-acetone solutions

    Science.gov (United States)

    Abe, Hiroshi; Murata, Keisuke; Kiyokawa, Shota; Yoshimura, Yukihiro

    2018-05-01

    Surface tension anomalies were observed in room temperature ionic liquid (RTIL)-acetone solutions. The RTILs are 1-alkyl-3-methylimidazorium iodide with [Cnmim][I] in a [Cnmim][I]-x mol% acetone. The maximum value of the surface tension appeared at 40 mol% acetone, although density decreased monotonically with an increase in acetone concentration. A small alkyl chain length effect of the Cnmim+ cations was observed in the surface tension. By the Gibbs adsorption isotherm, it was found that I- anion-mediated surface structure became dominant above 40 mol%. In the different [Cnmim][TFSI]-acetone mixtures, normal decay of the surface tension was observed on the acetone concentration scale, where TFSI- is bis(trifluoromethanesulfonyl)imide.

  2. Exotic hybrid mesons in hard electroproduction

    CERN Document Server

    Anikin, I V; Szymanowski, L; Teryaev, O V; Wallon, S

    2005-01-01

    We estimate the sizeable cross section for deep exclusive electroproduction of an exotic $J^{PC}=1^{-+}$ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as $1/Q^2$. This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in $\\alpha_{S}$ and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. We study the particular case where the hybrid meson decays through a $\\pi\\eta $ meson pair. We discuss the $\\pi\\eta$ generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of $\\pi$ and $\\eta$ mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very ...

  3. Transitions of tethered chain molecules under tension.

    Science.gov (United States)

    Luettmer-Strathmann, Jutta; Binder, Kurt

    2014-09-21

    An applied tension force changes the equilibrium conformations of a polymer chain tethered to a planar substrate and thus affects the adsorption transition as well as the coil-globule and crystallization transitions. Conversely, solvent quality and surface attraction are reflected in equilibrium force-extension curves that can be measured in experiments. To investigate these effects theoretically, we study tethered chains under tension with Wang-Landau simulations of a bond-fluctuation lattice model. Applying our model to pulling experiments on biological molecules we obtain a good description of experimental data in the intermediate force range, where universal features dominate and finite size effects are small. For tethered chains in poor solvent, we observe the predicted two-phase coexistence at transitions from the globule to stretched conformations and also discover direct transitions from crystalline to stretched conformations. A phase portrait for finite chains constructed by evaluating the density of states for a broad range of solvent conditions and tensions shows how increasing tension leads to a disappearance of the globular phase. For chains in good solvents tethered to hard and attractive surfaces we find the predicted scaling with the chain length in the low-force regime and show that our results are well described by an analytical, independent-bond approximation for the bond-fluctuation model for the highest tensions. Finally, for a hard or slightly attractive surface the stretching of a tethered chain is a conformational change that does not correspond to a phase transition. However, when the surface attraction is sufficient to adsorb a chain it will undergo a desorption transition at a critical value of the applied force. Our results for force-induced desorption show the transition to be discontinuous with partially desorbed conformations in the coexistence region.

  4. A Decoupling Control Algorithm for Unwinding Tension System Based on Active Disturbance Rejection Control

    Directory of Open Access Journals (Sweden)

    Shanhui Liu

    2013-01-01

    Full Text Available This paper presents a new control methodology based on active disturbance rejection control (ADRC for designing the tension decoupling controller of the unwinding system in a gravure printing machine. The dynamic coupling can be actively estimated and compensated in real time, which makes feedback control an ideal approach to designing the decoupling controller of the unwinding system. This feature is unique to ADRC. In this study, a nonlinear mathematical model is established according to the working principle of the unwinding system. A decoupling model is also constructed to determine the order and decoupling plant of the unwinding system. Based on the order and decoupling plant, an ADRC decoupling control methodology is designed to enhance the tension stability in the unwinding system. The effectiveness and capability of the proposed methodology are verified through simulation and experiments. The results show that the proposed strategy not only realises a decoupling control for the unwinding system but also has an effective antidisturbance capability and is robust.

  5. Effect of temperature and composition on the surface tension and surface properties of binary mixtures containing DMSO and short chain alcohols

    International Nuclear Information System (INIS)

    Bagheri, Ahmad; Fazli, Mostafa; Bakhshaei, Malihe

    2016-01-01

    Highlights: • Surface tension of DMSO + alcohol (methanol, ethanol and isopropanol) at various temperatures was measured. • The surface tension data of binary mixtures were correlated with four equations. • Intermolecular interaction of DMSO with alcohol was discussed. • The surface mole fraction of alcohol increase with increasing the length of alcohol chain. - Abstract: Surface tension of binary mixtures of methanol, ethanol and isopropanol with DMSO (dimethyl sulfoxide) was measured over the whole range of composition at atmospheric pressure of 82.5 kPa within the temperatures between (298.15 and 328.15) K. The experimental measurements were used to calculate in surface tension deviations (Δσ). The sign of Δσ for all temperatures is negative (except of methanol/DMSO system) because of the factors of hydrogen bonding and dipole–dipole interactions in the DMSO-alcohol systems. Surface tension values of the binary systems were correlated with FLW, MS, RK and LWW models. The mean standard deviation obtained from the comparison of experimental and calculated surface tension values for binary systems with three models (FLW, MS and RK) at various temperatures is less than 0.83. Also, the results of the LWW model were used to account for the interaction energy between alcohols and DMSO in binary mixtures. The temperature dependence of σ (surface tension) at fixed composition of solutions was used to estimate surface enthalpy, H s , and surface entropy, S s . The results obtained show that the values of the thermodynamic parameters for alcohol/DMSO mixtures decrease with increasing alkyl chain length of alcohol. Finally, the results are discussed in terms of surface mole fraction and lyophobicity using the extended Langmuir (EL) isotherm.

  6. Surface tensions of binary mixtures of ionic liquids with bis(trifluoromethylsulfonyl)imide as the common anion

    International Nuclear Information System (INIS)

    Oliveira, M.B.; Domínguez-Pérez, M.; Cabeza, O.; Lopes-da-Silva, J.A.; Freire, M.G.; Coutinho, J.A.P.

    2013-01-01

    Highlights: • Novel data for the surface tensions of mixtures [C 4 mim][NTf 2 ] + [C 4 C 1 mim]/[C 3 mpy]/[C 3 mpyr]/[C 3 mpip][NTf 2 ] are presented. • γ were determined at a fixed temperature, 298.2 K, and at atmospheric pressure, for the whole composition range. • Surface tension deviations showed the near ideal behavior of the selected mixtures. • Gibbs adsorption isotherms showed the surface preferential adsorption of one ionic liquid over the other. -- Abstract: While values for thermophysical properties of ionic liquids are becoming widely available, data for ionic liquid mixtures are still scarce. In an effort to overcome this limitation and understand the behavior of ionic liquid mixtures, novel data for the surface tension of mixtures composed of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C 4 mim][NTf 2 ], with other ionic liquids with a common anion, namely 1-butyl-2,3-dimethylimidazolium, [C 4 C 1 mim] + , 3-methyl-1-propylpyridinium, [C 3 mpy] + , 1-methyl-1-propylpyrrolidinium, [C 3 mpyr] + , and 1-methyl-1-propylpiperidinium, [C 3 mpip] + , were measured at T = 298.2 K and atmospheric pressure over the entire composition range. From the surface tension deviations derived from the experimental results, it was possible to infer that the cation alkyl chain length of the second ionic liquid constituting the mixture has a stronger influence in the ideal mixture behavior than the type of family the ionic liquid cation belongs to. The Gibbs adsorption isotherms, estimated from the experimental values, show that the composition of the vapor–liquid interface is not the same as that of the bulk and that the interface is richer in the ionic liquid with the lowest surface tension, [C 4 mim][NTf 2

  7. POSTOPERATIVE URINARY RETENTION AND EARLY REPOSITION OF TENSION-FREE VAGINAL TAPE

    Directory of Open Access Journals (Sweden)

    Marijan Lužnik

    2003-12-01

    Full Text Available Background. The purpose of this article is to show a possible method of treatment of postoperative urinary retention after an initial tension-free vaginal tape.Methods. From December 1999 to May 2003 we performed one hundred TVT procedures at our department, among them five women had postoperative urinary retention evaluated with catheterization. Revision and reposition of tension-free vaginal tape were performed if retention of urine was over 100 ml.Results. Urinary retention after an initial tension-free vaginal tape was successfully treated by early reposition of tension-free vaginal tape. This resulted in immediate residualfree voiding and continence, which remained unchanged at 6 week and 3 month follow-up.Conclusions. Postoperative urinary retention may be treated by reposition instead of dissection or elongation of the tension-free vaginal tape.

  8. New Hybrid Algorithms for Estimating Tree Stem Diameters at Breast Height Using a Two Dimensional Terrestrial Laser Scanner

    Directory of Open Access Journals (Sweden)

    Jianlei Kong

    2015-07-01

    Full Text Available In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH for tree trunks in forest areas is proposed. First, the information is collected by a two-dimensional terrestrial laser scanner (2DTLS, which emits laser pulses to generate a point cloud. After extraction and filtration, the laser point clusters of the trunks are obtained, which are optimized by an arithmetic means method. Then, an algebraic circle fitting algorithm in polar form is non-linearly optimized by the Levenberg-Marquardt method to form a new hybrid algorithm, which is used to acquire the diameters and positions of the trees. Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time. Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents.

  9. The tension as perturbative parameter in string theory

    International Nuclear Information System (INIS)

    Gamboa, J.

    1990-01-01

    We propose an approach to string theory where the zero theory is the null string. We find an explicit form of the propagator for the null string in the momentum space. We show that considering the tension as perturbative parameter, the perturbative series is completely summable and we find the propagator of the bosonic open string with tension T. (author) [pt

  10. Surface tension and density of Si-Ge melts

    Science.gov (United States)

    Ricci, Enrica; Amore, Stefano; Giuranno, Donatella; Novakovic, Rada; Tuissi, Ausonio; Sobczak, Natalia; Nowak, Rafal; Korpala, Bartłomiej; Bruzda, Grzegorz

    2014-06-01

    In this work, the surface tension and density of Si-Ge liquid alloys were determined by the pendant drop method. Over the range of measurements, both properties show a linear temperature dependence and a nonlinear concentration dependence. Indeed, the density decreases with increasing silicon content exhibiting positive deviation from ideality, while the surface tension increases and deviates negatively with respect to the ideal solution model. Taking into account the Si-Ge phase diagram, a simple lens type, the surface tension behavior of the Si-Ge liquid alloys was analyzed in the framework of the Quasi-Chemical Approximation for the Regular Solutions model. The new experimental results were compared with a few data available in the literature, obtained by the containerless method.

  11. Rein tension during canter

    NARCIS (Netherlands)

    Egenvall, Agneta; Eisersiö, Marie; Rhodin, Marie; van Weeren, P.R.; Roepstorff, Lars

    2015-01-01

    Riders generally use reins as a means for communication with the horse. At present, the signalling pattern is poorly understood. The aim of this study was to illustrate and analyse the rein tension patterns in a number of rider/horse combinations across a variety of exercises in the canter gait. Our

  12. Modelling dependable systems using hybrid Bayesian networks

    International Nuclear Information System (INIS)

    Neil, Martin; Tailor, Manesh; Marquez, David; Fenton, Norman; Hearty, Peter

    2008-01-01

    A hybrid Bayesian network (BN) is one that incorporates both discrete and continuous nodes. In our extensive applications of BNs for system dependability assessment, the models are invariably hybrid and the need for efficient and accurate computation is paramount. We apply a new iterative algorithm that efficiently combines dynamic discretisation with robust propagation algorithms on junction tree structures to perform inference in hybrid BNs. We illustrate its use in the field of dependability with two example of reliability estimation. Firstly we estimate the reliability of a simple single system and next we implement a hierarchical Bayesian model. In the hierarchical model we compute the reliability of two unknown subsystems from data collected on historically similar subsystems and then input the result into a reliability block model to compute system level reliability. We conclude that dynamic discretisation can be used as an alternative to analytical or Monte Carlo methods with high precision and can be applied to a wide range of dependability problems

  13. On innovation patterns and value-tensions in public services

    DEFF Research Database (Denmark)

    Fuglsang, Lars; Rønning, Rolf

    2015-01-01

    to the possibility of intertwined innovation patterns. Focusing public sector services, this paper agues that intertwined innovation patterns emerge within public services as a response to value-tensions. Values can be defined as measures for beneficial behaviour that guide innovation. Value-tensions in public...... services include tensions between the political, economic, communal, aesthetic and intellectual values. The contribution of the paper to service innovation research is the emphasis on the concept of intertwined innovation patterns, such as the intertwinement of science driven and task driven innovation....... Further, the paper contributes by pinpointing how varied values guide innovation in public services....

  14. A hybrid downscaling procedure for estimating the vertical distribution of ambient temperature in local scale

    Science.gov (United States)

    Yiannikopoulou, I.; Philippopoulos, K.; Deligiorgi, D.

    2012-04-01

    The vertical thermal structure of the atmosphere is defined by a combination of dynamic and radiation transfer processes and plays an important role in describing the meteorological conditions at local scales. The scope of this work is to develop and quantify the predictive ability of a hybrid dynamic-statistical downscaling procedure to estimate the vertical profile of ambient temperature at finer spatial scales. The study focuses on the warm period of the year (June - August) and the method is applied to an urban coastal site (Hellinikon), located in eastern Mediterranean. The two-step methodology initially involves the dynamic downscaling of coarse resolution climate data via the RegCM4.0 regional climate model and subsequently the statistical downscaling of the modeled outputs by developing and training site-specific artificial neural networks (ANN). The 2.5ox2.5o gridded NCEP-DOE Reanalysis 2 dataset is used as initial and boundary conditions for the dynamic downscaling element of the methodology, which enhances the regional representivity of the dataset to 20km and provides modeled fields in 18 vertical levels. The regional climate modeling results are compared versus the upper-air Hellinikon radiosonde observations and the mean absolute error (MAE) is calculated between the four grid point values nearest to the station and the ambient temperature at the standard and significant pressure levels. The statistical downscaling element of the methodology consists of an ensemble of ANN models, one for each pressure level, which are trained separately and employ the regional scale RegCM4.0 output. The ANN models are theoretically capable of estimating any measurable input-output function to any desired degree of accuracy. In this study they are used as non-linear function approximators for identifying the relationship between a number of predictor variables and the ambient temperature at the various vertical levels. An insight of the statistically derived input

  15. Tensions, arrangements et ambivalences alimentaires dans le couple mixte Tensions, arrangements and food ambivalence among mixed couples : French men married in Taiwan

    Directory of Open Access Journals (Sweden)

    Fong-Ming Yang

    2010-12-01

    Full Text Available A partir d’une enquête effectuée en milieu urbain taiwanais auprès de neuf Français(es ayant migré à Taiwan et marié(es avec des Taiwanais(es, l’auteur propose de réfléchir à la question des pratiques alimentaires en situation de mixité conjugale. Il fait l’hypothèse que ces pratiques alimentaires doivent être observées et s’apprécier en fonction des différents repas et moments alimentaires: petit-déjeuner, déjeuner, nourritures de rue, dîner conjugal, repas dans la belle famille. Ces situations sont riches d’ambivalences : attachement aux habitudes mais aussi passage du dégoût au goût ou bien de la méfiance à la curiosité, double appréciation pour la nourriture dont la présentation n’est pas estimée de la même façon que les produits eux-mêmes, efforts pour accepter les manières de table dans le cadre d’un rapport de force social et/ou affectif, enfin ‘‘oubli’’ de la question alimentaire au profit du lien social qu’il produit.From an investigation made in urban zones with nine male and female French people having migrated to Taiwan and married with Taiwaneses, the author studies the issue of food tensions in situation of mixed couples. He presents the hypothesis that these tensions vary according to food grips: breakfast, lunch, street foods, conjugal dinner, meals with allies. Such food tensions provoke varied practices and judgments: attachment to habits but also the passage of disgust to appreciation, distrust regarding curiosity, double appreciation for food displayed which is not esteemed in the same way as the products themselves, efforts to accept table manners within the framework of a social or emotional balance of power, finally ‘‘forgetting’’ the issue for the benefit of the social link which it produces.

  16. Tension-induced binding of semiflexible biopolymers

    Science.gov (United States)

    Benetatos, Panayotis; von der Heydt, Alice; Zippelius, Annette

    2015-03-01

    We investigate theoretically the effect of polymer tension on the collective behaviour of reversible cross-links. We use a model of two parallel-aligned, weakly-bending wormlike chains with a regularly spaced sequence of binding sites subjected to a tensile force. Reversible cross-links attach and detach at the binding sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and we show the emergence of a free energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the polymer tension increases. The force-induced first-order transition in the number of cross-links implies a sudden force-induced stiffening of the effective stretching modulus of the polymers. This mechanism may be relevant to the formation and stress-induced strengthening of stress fibers in the cytoskeleton. We acknowledge support by the Deutsche Forschungsgemeinschaft (DFG) via grant SFB-937/A1.

  17. Bilateral tension pneumothorax related to acupuncture.

    Science.gov (United States)

    Tagami, Rumi; Moriya, Takashi; Kinoshita, Kosaku; Tanjoh, Katsuhisa

    2013-06-01

    We report on a patient with a rare case of bilateral tension pneumothorax that occurred after acupuncture. A 69-year-old large-bodied man, who otherwise had no risk factors for spontaneous pneumothorax, presented with chest pressure, cold sweats and shortness of breath. Immediately after bilateral pneumothorax had been identified on a chest radiograph in the emergency room, his blood pressure and percutaneous oxygen saturation suddenly decreased to 78 mm Hg and 86%, respectively. We confirmed deterioration in his cardiopulmonary status and diagnosed bilateral tension pneumothorax. We punctured his chest bilaterally and inserted chest tubes for drainage. His vital signs promptly recovered. After the bilateral puncture and drainage, we learnt that he had been treated with acupuncture on his upper back. We finally diagnosed a bilateral tension pneumothorax based on the symptoms that appeared 8 h after the acupuncture. Because the patient had no risk factors for spontaneous pneumothorax, no alternative diagnosis was proposed. We recommend that patients receiving acupuncture around the chest wall must be adequately informed of the possibility of complications and expected symptoms, as a definitive diagnosis can be difficult without complete information.

  18. Tension-induced binding of semiflexible biopolymers

    International Nuclear Information System (INIS)

    Benetatos, Panayotis; Heydt, Alice von der; Zippelius, Annette

    2014-01-01

    We investigate theoretically the effect of polymer tension on the collective behavior of reversibly binding cross-links. For this purpose, we employ a model of two weakly bending wormlike chains aligned in parallel by a tensile force, with a sequence of inter-chain binding sites regularly spaced along the contours. Reversible cross-links attach and detach at the sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and find the emergence of a free-energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the tension increases. We show that this transition is related to the cross-over between weak and strong localization of a directed polymer in a pinning potential. The cross-over to the strongly bound state can be interpreted as a mechanism for force-stiffening which exceeds the capabilities of single-chain elasticity and thus available only to reversibly cross-linked polymers. (paper)

  19. A Model for Shovel Capital Cost Estimation, Using a Hybrid Model of Multivariate Regression and Neural Networks

    Directory of Open Access Journals (Sweden)

    Abdolreza Yazdani-Chamzini

    2017-12-01

    Full Text Available Cost estimation is an essential issue in feasibility studies in civil engineering. Many different methods can be applied to modelling costs. These methods can be divided into several main groups: (1 artificial intelligence, (2 statistical methods, and (3 analytical methods. In this paper, the multivariate regression (MVR method, which is one of the most popular linear models, and the artificial neural network (ANN method, which is widely applied to solving different prediction problems with a high degree of accuracy, have been combined to provide a cost estimate model for a shovel machine. This hybrid methodology is proposed, taking the advantages of MVR and ANN models in linear and nonlinear modelling, respectively. In the proposed model, the unique advantages of the MVR model in linear modelling are used first to recognize the existing linear structure in data, and, then, the ANN for determining nonlinear patterns in preprocessed data is applied. The results with three indices indicate that the proposed model is efficient and capable of increasing the prediction accuracy.

  20. The effects of combined elastic- and free-weight tension vs. free-weight tension on one-repetition maximum strength in the bench press.

    Science.gov (United States)

    Bellar, David M; Muller, Matthew D; Barkley, Jacob E; Kim, Chul-Ho; Ida, Keisuke; Ryan, Edward J; Bliss, Mathew V; Glickman, Ellen L

    2011-02-01

    The present study investigated the effects of training combining elastic tension, free weights, and the bench press. Eleven college-aged men (untrained) in the bench press participated in the 13-week study. The participants were first given instructions and then practiced the bench press, followed by a one-repetition maximum (1RM) test of baseline strength. Subjects were then trained in the bench press for 3 weeks to allow for the beginning of neural adaptation. After another 1RM test, participants were assigned to 1 of 2 conditions for the next 3 weeks of training: 85% Free-Weight Tension, 15% Elastic Tension (BAND), or 100% Free-Weight Tension (STAND). After 3 weeks of training and a third 1RM max test, participants switched treatments, under which they completed the final 3 weeks of training and the fourth 1RM test. Analysis via analysis of covariance revealed a significant (p ≤ 0.05) main effect for time and interaction effect for Treatment (BAND vs. STAND). Subsequent analysis via paired-samples t-test revealed the BAND condition was significantly better (p = 0.05) at producing raw gains in 1RM strength. (BAND 9.95 ± 3.7 kg vs. STAND 7.56 ± 2.8 kg). These results suggest that the addition of elastic tension to the bench press may be an effective method of increasing strength.

  1. A Computational Study of Richtmyer-Meshkov Instability with Surface Tension

    Science.gov (United States)

    Francois, Marianne; Velechovsky, Jan; Jibben, Zach; Masser, Thomas; LANL Collaboration

    2017-11-01

    We have added the capability to model surface tension in our adaptive mesh refinement compressible flow solver, xRage. Our surface tension capability employs the continuum surface force to model surface tension and the height function method to compute curvatures. We have verified our model implementation for the static and oscillating droplets test cases and the linear regime of the Rayleigh-Taylor instability. With this newly added capability, we have performed a numerical study of the effects of surface tension on single-mode and multi-mode Richtmyer-Meshkov instability. This work was performed under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy at Los Alamos National Laboratory under Contract No. DE-AC52 - 06NA25396.

  2. Proceedings of the colloquium: The response of liquids to dynamic tension

    International Nuclear Information System (INIS)

    Jones, A.V.

    1978-01-01

    The contributed papers are: - Tension pulses in a liquid column; - A generalized cavitationn model for liquids; - Transmission of a tension pulse through water; - Current status of the equation of state in Lagrangian codes; - The effects of the reflection of an underwater shock at a free surface; - The calculation of the propagation of tension and recompaction waves

  3. Spreading of oil films on water in the surface tension regime

    Energy Technology Data Exchange (ETDEWEB)

    Camp, D.W.

    1985-01-01

    Surface tension forces will cause an oil to spread over water if the tension of the oil film (the summed surface and interfacial tensions for bulk oil films, or the equilibrium spreading tension for monomolecular films) is less than the surface tension of water. For oil films spreading in a 40 cm long channel, measurements are made of leading edge position and lateral profiles of film thickness, velocity, and tension as a function of time. Measurements of the tension profiles, important for evaluating proposed theories, is made possible by the development of a new technique based on the Wilhelmy method. The oils studied were silicones, fatty acids and alcohols, and mixtures of surfactants in otherwise nonspreading oils. The single-component oils show an acceleration zone connecting a slow-moving inner region with a fast-moving leading monolayer. The dependence of film tension on film thickness for spreading single-component oils often differs from that at equilibrium. The mixtures show a bulk oil film configuration which extends to the leading edge and have velocity profiles which increase smoothly. The theoretical framework, similarity transformation, and asymptotic solutions of Foda and Cox for single-component oils were shown to be valid. An analysis of spreading surfactant-oil mixtures is developed which allows them to be treated under this framework. An easily-used semi-empirical model is proposed which allows them to be treated under this framework. An easily-used semi-empirical model is proposed which allows accurate prediction of detailed spreading behavior for any spreading oil.

  4. An exponential material model for prediction of the flow curves of several AZ series magnesium alloys in tension and compression

    International Nuclear Information System (INIS)

    Fereshteh-Saniee, F.; Barati, F.; Badnava, H.; Fallah Nejad, Kh.

    2012-01-01

    Highlights: ► The exponential model can represent flow behaviors of AZ series Mg alloys very well. ► Strain rate sensitivities of AZ series Mg alloys in compression are nearly the same. ► Effect of zinc element on tensile activation energy is higher than on compressive one. ► Activation energies of AZ80 and AZ81 in tension were greater than in compression. ► Tensile and compressive rate sensitivities of AZ80 are not close to each other. -- Abstract: This paper is concerned with flow behaviors of several magnesium alloys, such as AZ31, AZ80 and AZ81, in tension and compression. The experiments were performed at elevated temperatures and for various strain rates. In order to eliminate the effect of inhomogeneous deformation in tensile and compression tests, the Bridgeman’s and numerical correction factors were respectively employed. A two-section exponential mathematical model was also utilized for prediction of flow stresses of different magnesium alloys in tension and compression. Moreover, based on the compressive flow model proposed, the peak stress and the relevant true strain could be estimated. The true stress and strain of the necking point can also be predicted using the corresponding relations. It was found that the flow behaviors estimated by the exponential flow model were encouragingly in very good agreement with experimental findings.

  5. Fatigue in tension perpendicular to the grain

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1999-01-01

    Traditinally fatigue resistance is quantified as number of cycles to failure at a given stress level. A previous study by the authors showed that fatigue in compression parallel to the grain is governed partly by duration of load and partly by an effect of loading, i.e. a combination of a creep...... mechanism and a mechanism connected to damage introduce in the loading sequences. The purpose of the present study is to disentangle the effect of duration of load from the effect of load oscillation in fatigue in tension perpendicular to the grain. Fatigue experiments are made on small specimens...... and on dowel type joints with slotted in steel plates. In series of ten, the small specimens are taken to fatigue failure in uniform tension at square wave shaped load cycles at 0.01 Hz and 0.1 Hz. In order to test the predictive validity of the result from the small tension specimens, fatigue experiments...

  6. Fatigue In Tension Perpendicular to the Grain

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Uhre; Hoffmeyer, Preben

    2004-01-01

    Traditionally fatigue resistance is quantified as number of cycles to failure at a given stress level. A previous study by the authors showed that fatigue in compression parallel to the grain is governed partly by duration of load and partly by an effect of loading, i.e. a combination of a creep...... mechanism and a mechanism connected to damage introduced in the loading sequences. The purpose of the present study is to disentangle the effect of duration of load from the effect of load oscillation in fatigue in tension perpendicular to the grain. Fatigue experiments are made on small specimens...... and on dowel type joints with slotted in steel plates. In series of ten, the small specimens are taken to fatigue failure in uniform tension at square wave shaped load cycles at 0.01 Hz and 0.1 Hz. In arder to test the predictive validity of the result from the small tension specimens, fatigue experiments...

  7. Surface tension of normal and heavy water

    International Nuclear Information System (INIS)

    Straub, J.; Rosner, N.; Grigull, V.

    1980-01-01

    A Skeleton Table and simple interpolation equation for the surface tension of light water was developed by the Working Group III of the International Association for the Properties of Steam and is recommended as an International Standard. The Skeleton Table is based on all known measurements of the surface tension and individual data were weighted corresponding to the accuracy of the measurements. The form of the interpolation equation is based on a physical concept. It represents an extension of van der Waals-equation, where the exponent conforms to the 'Scaling Laws'. In addition for application purposes simple relations for the Laplace-coefficient and for the density difference between the liquid and gaseous phases of light water are given. The same form of interpolation equation for the surface tension can be used for heavy water, for which the coefficients are given. However, this equation is based only on a single set of data. (orig.) [de

  8. Modeling combined tension-shear failure of ductile materials

    International Nuclear Information System (INIS)

    Partom, Y

    2014-01-01

    Failure of ductile materials is usually expressed in terms of effective plastic strain. Ductile materials can fail by two different failure modes, shear failure and tensile failure. Under dynamic loading shear failure has to do with shear localization and formation of adiabatic shear bands. In these bands plastic strain rate is very high, dissipative heating is extensive, and shear strength is lost. Shear localization starts at a certain value of effective plastic strain, when thermal softening overcomes strain hardening. Shear failure is therefore represented in terms of effective plastic strain. On the other hand, tensile failure comes about by void growth under tension. For voids in a tension field there is a threshold state of the remote field for which voids grow spontaneously (cavitation), and the material there fails. Cavitation depends on the remote field stress components and on the flow stress. In this way failure in tension is related to shear strength and to failure in shear. Here we first evaluate the cavitation threshold for different remote field situations, using 2D numerical simulations with a hydro code. We then use the results to compute examples of rate dependent tension-shear failure of a ductile material.

  9. Hybrid Force Control Based on ICMAC for an Astronaut Rehabilitative Training Robot

    Directory of Open Access Journals (Sweden)

    Lixun Zhang

    2012-08-01

    Full Text Available A novel Astronaut Rehabilitative Training Robot (ART based on a cable-driven mechanism is represented in this paper. ART, a typical passive force servo system, can help astronauts to bench press in a microgravity environment. The purpose of this paper is to design controllers to eliminate the surplus force caused by an astronaut's active movements. Based on the dynamics modelling of the cable-driven unit, a hybrid force controller based on improved credit assignment CMAC (ICMAC is presented. A planning method for the cable tension is proposed so that the dynamic load produced by the ART can realistically simulate the gravity and inertial force of the barbell in a gravity environment. Finally, MATLAB simulation results of the man-machine cooperation system are provided in order to verify the effectiveness of the proposed control strategy. The simulation results show that the hybrid control method based on the structure invariance principle can inhibit the surplus force and that ICMAC can improve the dynamic performance of the passive force servo system. Furthermore, the hybrid force controller based on ICMAC can ensure the stability of the system.

  10. Curvature dependence of the electrolytic liquid-liquid interfacial tension

    NARCIS (Netherlands)

    Bier, Markus; de Graaf, J.; Zwanikken, J.W.; van Roij, R.H.H.G.

    2009-01-01

    The interfacial tension of a liquid droplet surrounded by another liquid in the presence of microscopic ions is studied as a function of the droplet radius. An analytical expression for the interfacial tension is obtained within a linear Poisson–Boltzmann theory and compared with numerical results

  11. Indirect coupling of phosphate release to de novo tension generation during muscle contraction.

    Science.gov (United States)

    Davis, J S; Rodgers, M E

    1995-01-01

    A key question in muscle contraction is how tension generation is coupled to the chemistry of the actomyosin ATPase. Biochemical and mechanochemical experiments link tension generation to a change in structure associated with phosphate release. Length-jump and temperature-jump experiments, on the other hand, implicate phase 2slow, a significantly faster, markedly strain-sensitive kinetic process in tension generation. We use a laser temperature jump to probe the kinetics and mechanism of tension generation in skinned rabbit psoas fibers--an appropriate method since both phosphate release and phase 2slow are readily perturbed by temperature. Kinetics characteristic of the structural change associated with phosphate release are observed only when phosphate is added to fibers. When present, it causes a reduction in fiber tension; otherwise, no force is generated when it is perturbed. We therefore exclude this step from tension generation. The kinetics of de novo tension generation by the temperature-jump equivalent of phase 2slow appear unaffected by phosphate binding. We therefore propose that phosphate release is indirectly coupled to de novo tension generation via a steady-state flux through an irreversible step. We conclude that tension generation occurs in the absence of chemical change as the result of an entropy-driven transition between strongly bound crossbridges in the actomyosin-ADP state. The mechanism resembles the operation of a clock, with phosphate release providing the energy to tension the spring, and the irreversible step functions as the escapement mechanism, which is followed in turn by tension generation as the movement of the hands. Images Fig. 6 PMID:7479824

  12. A hybrid pareto mixture for conditional asymmetric fat-tailed distributions.

    Science.gov (United States)

    Carreau, Julie; Bengio, Yoshua

    2009-07-01

    In many cases, we observe some variables X that contain predictive information over a scalar variable of interest Y , with (X,Y) pairs observed in a training set. We can take advantage of this information to estimate the conditional density p(Y|X = x). In this paper, we propose a conditional mixture model with hybrid Pareto components to estimate p(Y|X = x). The hybrid Pareto is a Gaussian whose upper tail has been replaced by a generalized Pareto tail. A third parameter, in addition to the location and spread parameters of the Gaussian, controls the heaviness of the upper tail. Using the hybrid Pareto in a mixture model results in a nonparametric estimator that can adapt to multimodality, asymmetry, and heavy tails. A conditional density estimator is built by modeling the parameters of the mixture estimator as functions of X. We use a neural network to implement these functions. Such conditional density estimators have important applications in many domains such as finance and insurance. We show experimentally that this novel approach better models the conditional density in terms of likelihood, compared to competing algorithms: conditional mixture models with other types of components and a classical kernel-based nonparametric model.

  13. Methodology for the analysis of self-tensioned wooden structural floors

    Directory of Open Access Journals (Sweden)

    F. Suárez-Riestra

    2017-09-01

    Full Text Available It is described a self-tensioning system constituted by a force multiplying device which, attached to the supports of the ends of the structural element, is able to convert the vertical resultant from the gravitatonial actions into an effective tensioning action, through the movement that was induced by a set of rods. The self-tensioning system is able to offer a high performance, thanks to the beneficial effect of the opposite deflection generated by the tensioning, in proportion to the increasing of the gravitational action. This allows to design long-span timber ribbed floors using reduced depths. The complexity of calculation due to the non-linearity of the system can be obviated with the methodology of analysis developed in the article. In order to illustrate the advantages of the self-tensioning system and the methodology of analysis which were developed, six cases of ribbed floors have been analysed, with spans of 9, 12 and 15 m and variable using loads of 3,00 kN/m2 and 5,00 kN/m2.

  14. Development of a 14-inch ID High-Pressure Hybrid Riser for SBOP Drilling Développement d’un riser hybride 14”ID haute pression pour le forage SBOP

    Directory of Open Access Journals (Sweden)

    Persent E.

    2009-11-01

    Full Text Available This paper discusses the development of a 14-inch ID high-pressure hybrid riser (10 000 psi for surface BOP drilling in ultra-deep water (10 000 ft. The high-pressure hybrid riser system is obtained by adapting and combining two existing technologies, previously developed by the IFP for other applications: – the Clip connector, a double breech-block type connector to provide a quick and safe connection for riser joints; – hybrid pipe technology, a steel pipe hoop-wound with tapes of carbon fibers impregnated with polyamide thermoplastic resin. IFP has developed a new 14-inch ID HP Clip connector for the hybrid riser application. The connector is capable of withstanding a 2.8 million pound tension and a 10 000 psi operating pressure. In addition, a 16-inch nominal OD hybrid riser pipe has been designed to replace the steel riser pipe with a thinnerwalled hoop-wound steel pipe. The significant weight savings that can be achieved with the hybrid riser pipe make it possible to design an effective riser architecture to withstand the high pressure and deep water requirements. Pursuant to design studies, a 14-inch ID prototype assembly consisting of two hybrid riser pipe sections with a high-pressure Clip connector was manufactured. A test program, including burst and collapse tests as well as cyclic fatigue testing, was formulated and carried out to qualify the performance of the Clip connector and hybrid riser pipe system. Completion of hybrid pipe additional fatigue testing and realization of a scale-one field testing of the hybrid riser are considered as the next steps of the project. To date, the main test results (burst, collapse, fatigue resistance confirm that the Clip connector and the hybrid pipe technologies are well suited for ultra-deep sea drilling with a surface BOP. However, the fatigue resistance of hybrid riser pipes still needs to be better characterized. Cet article présente le développement d’un riser hybride 14”ID haute

  15. A Hybrid Neural Network-Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics

    Science.gov (United States)

    Kobayashi, Takahisa; Simon, Donald L.

    2001-01-01

    In this paper, a model-based diagnostic method, which utilizes Neural Networks and Genetic Algorithms, is investigated. Neural networks are applied to estimate the engine internal health, and Genetic Algorithms are applied for sensor bias detection and estimation. This hybrid approach takes advantage of the nonlinear estimation capability provided by neural networks while improving the robustness to measurement uncertainty through the application of Genetic Algorithms. The hybrid diagnostic technique also has the ability to rank multiple potential solutions for a given set of anomalous sensor measurements in order to reduce false alarms and missed detections. The performance of the hybrid diagnostic technique is evaluated through some case studies derived from a turbofan engine simulation. The results show this approach is promising for reliable diagnostics of aircraft engines.

  16. Managing Tensions Between New and Existing Business Models

    DEFF Research Database (Denmark)

    Sund, Kristian J.; Bogers, Marcel; Villarroel Fernandez, Juan Andrei

    2016-01-01

    Exploring new business models may be a good way to stay competitive, but doing so can create tensions internally, in areas such as organizational structure and competition for resources. Companies exploring business model innovation may not recognize the inevitability of these tensions and thus b...... be poorly prepared to manage them. But understanding these issues may lessen some of the organizational challenges associated with business model innovation....

  17. Contact angle control of sessile drops on a tensioned web

    Science.gov (United States)

    Park, Janghoon; Kim, Dongguk; Lee, Changwoo

    2018-04-01

    In this study, the influence of the change of tension applied to flexible and thin web substrate on the contact angle of sessile drop in roll-to-roll system was investigated. Graphene oxide and deionized water solutions were used in the experiments. Tension was changed to 29, 49, and 69 N, and the casting distance of the micropipette and the material was set to 10, 20, and 40 mm, and the droplet volume was set to 10, 20, and 30 μL, respectively. Statistical analysis of three variables and analysis of the variance methodology showed that the casting distance was most significant for the contact angle change, and the most interesting tension variable was also affected. The change in tension caused the maximum contact angle to change by 5.5°. The tension was not uniform in the width direction. When the droplet was applied in the same direction in the width direction, it was confirmed that the tension unevenness had great influence on the contact angle up to 11°. Finally, the casting distance, which has a large effect on the contact angle, was calibrated in the width direction to reduce the width direction contact angle deviation to 1%. This study can be applied to fine patterning research using continuous inkjet printing and aerosol jet printing, which are roll-to-roll processes based on droplet handling.

  18. Corrosion characteristics of post-tensioning strands in ungrouted ducts : summary.

    Science.gov (United States)

    2011-01-01

    To prevent corrosion of post-tensioning strands, FDOT construction specifications currently require post-tensioning ducts to be grouted within seven calendar days of strand installation. This period challenges construction schedules on large projects...

  19. Measurement of calcium influx in tethered rings of rabbit aorta under tension

    International Nuclear Information System (INIS)

    Gleason, M.M.; Ratz, P.H.; Flaim, S.F.

    1985-01-01

    Calcium (Ca) influx in vascular smooth muscle is routinely measured in untethered preparations not under passive stretch, and Ca influx data are correlated with data for steady-state isometric tension obtained under parallel conditions from tethered preparations under passive stretch. The validity of this method was tested by simultaneous measurement of Ca influx and tension in tethered rings of rabbit thoracic aorta. Ca influx ( 45 Ca 3-min pulse) and tension were measured at 3 and 30 min after norepinephrine (NE) or KCl and under control (no agonist) conditions. Active tension was significantly altered by variations in passive tension. Ca influx was unaffected by passive tension under control, NE, or KCl conditions, and results were similar at 3 and 30 min. The results confirm the validity of correlating Ca influx data from untethered rings with steady-state contractile response data obtained from tethered rings under similar experimental conditions

  20. Phenylephrine Decreases Vascular Tension in Goat Arteries in Specific Circumstances.

    Directory of Open Access Journals (Sweden)

    Renu R Raj

    Full Text Available Phenylephrine (PE causes vasoconstriction through alpha adrenergic receptors. PE-induced vasodilatation has also been reported earlier in pre-constricted vessels. Here we demonstrate in spiral strips of goat arteries that addition of PE can decrease tone even from base-line levels (i.e. not pre-constricted and show that this process requires nitric oxide (NO and alpha adrenergic stimulation, but is cGMP-independent. Under control conditions, PE caused vasoconstriction, but under conditions where NO levels are higher, as with L-Arginine or sodium nitroprusside, PE decreased vessel tension. L-Arginine/PE combination was not able to decrease tension when alpha adrenoceptors were blocked with Phentolamine or endothelial nitric oxide synthase (eNOS was blocked with Nω-Nitro-L-arginine (L-NNA. Propranolol, a beta blocker, was unable to prevent the reduction in tension by the L-Arginine/PE combination. Adrenaline and noradrenaline (and not isoproterenol also reduced vessel tension in the presence of L-Arginine. Even when NO levels were not enhanced, relieving NO from having to stimulate the enzyme soluble guanylyl cyclase (sGC (either by using sGC blockers, namely ODQ or methylene blue, or by enhancing cGMP levels (with sildenafil which by negative feedback probably inhibits sGC led to PE-induced reduction of vascular tension. PMA-phorbol myristate acetate-an agonist which stimulates Protein Kinase C was able to prevent the ability of PE to reduce vascular tension in a high NO environment. Our conclusion is that PE reduces vascular tension through alpha adrenoceptors if there is excess NO availability to activate a putative pathway. Though the reduction of vessel tone by PE is dependent on NO, it is independent of cGMP. Prior treatment with PMA or PE itself can prevent further PE-induced reduction of tension in a high NO environment. The results here suggest, counter-intuitively, that alpha blockers may be of help in the treatment of septic shock

  1. A microfluidic cell culture array with various oxygen tensions.

    Science.gov (United States)

    Peng, Chien-Chung; Liao, Wei-Hao; Chen, Ying-Hua; Wu, Chueh-Yu; Tung, Yi-Chung

    2013-08-21

    Oxygen tension plays an important role in regulating various cellular functions in both normal physiology and disease states. Therefore, drug testing using conventional in vitro cell models under normoxia often possesses limited prediction capability. A traditional method of setting an oxygen tension in a liquid medium is by saturating it with a gas mixture at the desired level of oxygen, which requires bulky gas cylinders, sophisticated control, and tedious interconnections. Moreover, only a single oxygen tension can be tested at the same time. In this paper, we develop a microfluidic cell culture array platform capable of performing cell culture and drug testing under various oxygen tensions simultaneously. The device is fabricated using an elastomeric material, polydimethylsiloxane (PDMS) and the well-developed multi-layer soft lithography (MSL) technique. The prototype device has 4 × 4 wells, arranged in the same dimensions as a conventional 96-well plate, for cell culture. The oxygen tensions are controlled by spatially confined oxygen scavenging chemical reactions underneath the wells using microfluidics. The platform takes advantage of microfluidic phenomena while exhibiting the combinatorial diversities achieved by microarrays. Importantly, the platform is compatible with existing cell incubators and high-throughput instruments (liquid handling systems and plate readers) for cost-effective setup and straightforward operation. Utilizing the developed platform, we successfully perform drug testing using an anti-cancer drug, triapazamine (TPZ), on adenocarcinomic human alveolar basal epithelial cell line (A549) under three oxygen tensions ranging from 1.4% to normoxia. The developed platform is promising to provide a more meaningful in vitro cell model for various biomedical applications while maintaining desired high throughput capabilities.

  2. Analysis of Hybrid Hydrogen Systems: Final Report

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-01

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

  3. String tensions for lattice gauge theories in 2+1 dimensions

    International Nuclear Information System (INIS)

    Ambjoern, J.; Hey, A.J.G.; Otto, S.

    1982-01-01

    Compact U(1) and SU(2) lattice gauge theories in 3 euclidean dimensions are studied by standard Monte Carlo techniques. The question of extracting reliable string tensions from these theories is examined in detail, including a comparison of the Monte Carlo Wilson loop data with weak coupling predictions and a careful error analysis: our conclusions are rather different from those of previous investigations of these theories. In the case of U(1) theory, we find that only a tiny range of β values can possibly be relevant for extracting a string tension and we are unable to convincingly demonstrate the expected exponential dependence of the string tension on β. For the SU(2) theory we are able to determine, albeit with rather large errors, a string tension from a study of Wilson loops. (orig.)

  4. Creating Tension in Writing.

    Science.gov (United States)

    Folta, Bernarr

    This paper discusses the rationale and teaching methods for a six-week unit, for a high school freshman English Class, on perception, semantics, and writing, which places special focus on developing tension in student writing. The first four objectives of the course focus on perception and the next two focus on semantics. The seventh…

  5. Surface tension modelling of liquid Cd-Sn-Zn alloys

    Science.gov (United States)

    Fima, Przemyslaw; Novakovic, Rada

    2018-06-01

    The thermodynamic model in conjunction with Butler equation and the geometric models were used for the surface tension calculation of Cd-Sn-Zn liquid alloys. Good agreement was found between the experimental data for limiting binaries and model calculations performed with Butler model. In the case of ternary alloys, the surface tension variation with Cd content is better reproduced in the case of alloys lying on vertical sections defined by high Sn to Zn molar fraction ratio. The calculated surface tension is in relatively good agreement with the available experimental data. In addition, the surface segregation of liquid ternary Cd-Sn-Zn and constituent binaries has also been calculated.

  6. On the Minimum Cable Tensions for the Cable-Based Parallel Robots

    Directory of Open Access Journals (Sweden)

    Peng Liu

    2014-01-01

    Full Text Available This paper investigates the minimum cable tension distributions in the workspace for cable-based parallel robots to find out more information on the stability. First, the kinematic model of a cable-based parallel robot is derived based on the wrench matrix. Then, a noniterative polynomial-based optimization algorithm with the proper optimal objective function is presented based on the convex optimization theory, in which the minimum cable tension at any pose is determined. Additionally, three performance indices are proposed to show the distributions of the minimum cable tensions in a specified region of the workspace. An important thing is that the three performance indices can be used to evaluate the stability of the cable-based parallel robots. Furthermore, a new workspace, the Specified Minimum Cable Tension Workspace (SMCTW, is introduced, within which all the minimum tensions exceed a specified value, therefore meeting the specified stability requirement. Finally, a camera robot parallel driven by four cables for aerial panoramic photographing is selected to illustrate the distributions of the minimum cable tensions in the workspace and the relationship between the three performance indices and the stability.

  7. Robust total energy demand estimation with a hybrid Variable Neighborhood Search – Extreme Learning Machine algorithm

    International Nuclear Information System (INIS)

    Sánchez-Oro, J.; Duarte, A.; Salcedo-Sanz, S.

    2016-01-01

    Highlights: • The total energy demand in Spain is estimated with a Variable Neighborhood algorithm. • Socio-economic variables are used, and one year ahead prediction horizon is considered. • Improvement of the prediction with an Extreme Learning Machine network is considered. • Experiments are carried out in real data for the case of Spain. - Abstract: Energy demand prediction is an important problem whose solution is evaluated by policy makers in order to take key decisions affecting the economy of a country. A number of previous approaches to improve the quality of this estimation have been proposed in the last decade, the majority of them applying different machine learning techniques. In this paper, the performance of a robust hybrid approach, composed of a Variable Neighborhood Search algorithm and a new class of neural network called Extreme Learning Machine, is discussed. The Variable Neighborhood Search algorithm is focused on obtaining the most relevant features among the set of initial ones, by including an exponential prediction model. While previous approaches consider that the number of macroeconomic variables used for prediction is a parameter of the algorithm (i.e., it is fixed a priori), the proposed Variable Neighborhood Search method optimizes both: the number of variables and the best ones. After this first step of feature selection, an Extreme Learning Machine network is applied to obtain the final energy demand prediction. Experiments in a real case of energy demand estimation in Spain show the excellent performance of the proposed approach. In particular, the whole method obtains an estimation of the energy demand with an error lower than 2%, even when considering the crisis years, which are a real challenge.

  8. Higher-Order Hybrid Gaussian Kernel in Meshsize Boosting Algorithm

    African Journals Online (AJOL)

    In this paper, we shall use higher-order hybrid Gaussian kernel in a meshsize boosting algorithm in kernel density estimation. Bias reduction is guaranteed in this scheme like other existing schemes but uses the higher-order hybrid Gaussian kernel instead of the regular fixed kernels. A numerical verification of this scheme ...

  9. Impact of fusion-fission hybrids on world nuclear future

    International Nuclear Information System (INIS)

    Abdel-Khalick, S.; Jansen, P.; Kessler, G.; Klumpp, P.

    1980-08-01

    An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been: (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrids are coupled to the breeders. The results also indicate that from a resource standpoint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

  10. Incidence of migraine and tension-type headache in three different populations at risk within the German DMKG headache study.

    Science.gov (United States)

    Khil, Laura; Pfaffenrath, Volker; Straube, Andreas; Evers, Stefan; Berger, Klaus

    2012-03-01

    Unlike the prevalence, the incidence of headache disorders has attracted only little attention in epidemiological research. Different definitions of the 'population at risk' among the few published migraine and tension-type headache incidence studies limit their comparability and warrant further research. Therefore, we analysed data from the German Migraine and Headache Society (DMKG). Incidences were assessed in the general population in Germany via standardized headache questions using the International Classification of Headache Disorders, 2nd Edition (ICHD-2). The population was drawn from a 5-year age-group- stratified and gender-stratified random sample from the population register. Of the 1312 baseline participants examined between 2003 and 2004, 1122 (85.5%) participated in the follow-up in 2006 and were the basis for three different populations at risk. We found that the three populations differed in size, age, gender and incidence estimate. The total sample incidence of migraine ranged between 0% and 3.3% and of tension-type headache between 5.3% and 9.2% depending on the definition of 'at risk'. We concluded that one significant problem in headache incidence estimation is the definition of 'at risk', limiting comparability. Thus, this study supports the need for a common definition for prospective headache incidence estimations.

  11. Hybrid dynamical systems observation and control

    CERN Document Server

    Defoort, Michael

    2015-01-01

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

  12. 33 CFR 147.817 - Sir Douglas Morpeth Tension Leg Platform safety zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sir Douglas Morpeth Tension Leg... HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.817 Sir Douglas Morpeth Tension Leg Platform safety zone. (a) Description. The Sir Douglas Morpeth Tension Leg Platform (Morpeth...

  13. Effect of electrolytes on surface tension and surface adsorption of 1-hexyl-3-methylimidazolium chloride ionic liquid in aqueous solution

    International Nuclear Information System (INIS)

    Ghasemian, Ensieh; Najafi, Mojgan; Rafati, Amir Abbas; Felegari, Zahra

    2010-01-01

    Surface and bulk properties of 1-hexyl-3-methylimidazolium chloride [C 6 mim][Cl] as an ionic liquid (IL) have been investigated by surface tension and electrical conductivity techniques at various temperatures. Results reveal that the ionic liquid behaves as surfactant-like and aggregates in aqueous solution. Critical aggregation concentration (cac) values obtained by conductivity and surface tension measurements are in good agreement with values found in the literature. A series of important and useful adsorption parameters including cac, surface excess concentration (Γ), and minimum surface area per molecule (A min ) at the air + water interface were estimated from surface tension in the presence and absence of different electrolytes. Obtained data show that the surface tension as well as the cac of [C 6 mim][Cl] is reduced by electrolytes. Also, values of surface excess concentration (Γ) show that the IL ions in the presence of electrolyte have much larger affinity to adsorption at the surface and this affinity increased in aqueous electrolyte solution in the order of I - > Br - > Cl - for counter ion of salts that was explained in terms of a larger repulsion of chloride anions from interface to the bromide and iodide anion as well as difference in their excess polarizability.

  14. Ethical tensions: A qualitative systematic review of new graduate perceptions.

    Science.gov (United States)

    Hazelwood, Tori; Murray, Carolyn M; Baker, Amy; Stanley, Mandy

    2017-01-01

    New graduate transition into the workforce is challenging and can involve managing ethical tensions. Ethical tensions cause new graduates to doubt their capabilities due to their lack of experience. To support new graduates, we need to know what these ethical tensions are. To explore the ethical tensions perceived to occur in practice for new graduate health professionals. This qualitative systematic review involved a search of five databases (Medline, EMBASE, AMED, CINAHL and Scopus) which resulted in the retrieval of 3554 papers. After the two-phased screening process, eight studies were identified that met the inclusion criteria and had rich data on the review question. Articles were read several times, critically appraised and analysed through thematic analysis. Ethical considerations: No ethical approval was required for the systematic review. The review was conducted following well-established reporting guidelines enabling transparency and rigour. Studies originated from Australia, United States, Iran and China. One study included speech pathologists and seven were with nurses. Four themes included the following: (1) enduring an unknown workplace culture that generates uncertainty without support for new graduates; (2) being vulnerable because of distress from bullying, exclusion and being a scapegoat; (3) constraining systems and institutional restrictions that cause dilemmas; and (4) experiencing disillusionment from lost ideals about ethical practice. This review has brought to light the vulnerability of new graduates to negative workplace culture and collegial incivility. In addition, new graduates are subjected to ethical tensions created by institutional constraints which can create dilemmas and uncertainties through practice that does not align with what they anticipated. Understanding ethical tensions experienced by new graduates enables provision of informed support. There needs to be considerable cultural change for orientation and socialisation of

  15. The Seven Deadly Tensions of Health-Related Human Information Behavior

    Directory of Open Access Journals (Sweden)

    J. David Johnson

    2015-08-01

    Full Text Available Tensions are a ubiquitous feature of social life and are manifested in a number of particular forms: contradictory logics, competing demands, clashes of ideas, contradictions, dialectics, irony, paradoxes, and/or dilemmas. This essay aims to explore in detail tensions surrounding seven common findings of the information seeking literature relating to: interpersonal communication, accessibility, level of skill, individual preferences, psychological limits, inertia, and costs. Our incomplete understanding of these tensions can lead us to suggest resolutions that do not recognize their underlying dualities. Human information behavior stands at the intersection of many important theoretical and policy issues (e.g., personalized medicine. Policy makers need to be more attuned to these basic tensions of information seeking recognizing the real human limits they represent to informing the public. So, even if you build a great information system, people will not necessarily use it because of the force of these underlying tensions. While rationality rules systems, irrationality rules people. The proliferation of navigator roles over the last several years is actually a hopeful sign: recognition that people need a human interface to inform them about our ever more complex health care systems.

  16. Evaluation of tension stiffening effect on the crack width calculation of flexural RC members

    Directory of Open Access Journals (Sweden)

    Said M. Allam

    2013-06-01

    Full Text Available Building codes consider the tension stiffening when calculating the crack width of the flexural members. A simple analytical procedure is proposed for the determination of forces, stresses and strains acting on a reinforced concrete section subjected to flexure considering the concrete contribution in tension up to tensile concrete strain corresponding to the cracking strength of concrete. This analytical method gives the minimum value (lower bound of tension stiffening. Also, a commercial Finite Element Program (ABAQUS 2007 was used to perform non-linear analysis in order to evaluate the total contribution of the tensioned concrete in carrying loads which may be considered as the upper bound of tension stiffening. In addition, a comparison is carried out among the different codes using four reinforced concrete rectangular models to compare and evaluate the tension stiffening with proposed analytical lower bound tension stiffening and upper bound as obtained by ABAQUS. The models include different percentages of flexural steel ratio. The comparison revealed that the codes’ equations always consider tension stiffening lying between lower and upper bound of tension stiffening proposed in this study. Also, the study showed that the tension stiffening decreases with the increase of the percentage of the flexural reinforcement ratio.

  17. Contact Angles and Surface Tension of Germanium-Silicon Melts

    Science.gov (United States)

    Croell, A.; Kaiser, N.; Cobb, S.; Szofran, F. R.; Volz, M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Precise knowledge of material parameters is more and more important for improving crystal growth processes. Two important parameters are the contact (wetting) angle and the surface tension, determining meniscus shapes and surface-tension driven flows in a variety of methods (Czochralski, EFG, floating-zone, detached Bridgman growth). The sessile drop technique allows the measurement of both parameters simultaneously and has been used to measure the contact angles and the surface tension of Ge(1-x)Si(x) (0 less than or equal to x less than or equal to 1.3) alloys on various substrate materials. Fused quartz, Sapphire, glassy carbon, graphite, SiC, carbon-based aerogel, pyrolytic boron nitride (pBN), AIN, Si3N4, and polycrystalline CVD diamond were used as substrate materials. In addition, the effect of different cleaning procedures and surface treatments on the wetting behavior were investigated. Measurements were performed both under dynamic vacuum and gas atmospheres (argon or forming gas), with temperatures up to 1100 C. In some experiments, the sample was processed for longer times, up to a week, to investigate any changes of the contact angle and/or surface tension due to slow reactions with the substrate. For pure Ge, stable contact angles were found for carbon-based substrates and for pBN, for Ge(1-x)Si(x) only for pBN. The highest wetting angles were found for pBN substrates with angles around 170deg. For the surface tension of Ge, the most reliable values resulted in gamma(T) = (591- 0.077 (T-T(sub m)) 10(exp -3)N/m. The temperature dependence of the surface tension showed similar values for Ge(1-x)Si(x), around -0.08 x 10(exp -3)N/m K, and a compositional dependence of 2.2 x 10(exp -3)N/m at%Si.

  18. THE STAGES OF HETEROTIC HYBRIDS F1 DEVELOPMENT IN EUROPEAN RADISH

    Directory of Open Access Journals (Sweden)

    M. A. Kosenko

    2017-01-01

    Full Text Available The scheme  of  development  of  two-line  of  hybrids  F1  in European radish based on self-incompatibility includes five stages, as follows: 1 – selection of self-incompatible lines, common and specified combining ability estimation; 2 – inbreeding and selection to make the lines homozygous for morphological traits, common and specified combining ability estimation; maintenance and reproduction of self-incompatible lines; 4 – production of hybrid seeds. The research work on assessment of hybrid F1 that were obtained from cross of eight self-incompatible lines of European winter radish by the Griffing’s method was carried out in 2016. The assessment of length, diameter and yield of radish root was performed. According to the root shape the heterotic hybrids F1 were divided into three groups: rounded-flat,  48.2%; round, 50.0%; and flatten-round,  1.8%. The level of root marketability of hybrids F1 reached 100%. As a result of the work the promising hybrid combination distinguished by high uniformity, marketability and high yield were selected out.

  19. Tensions within Teaching: An Autoethnography of an American Teacher

    Science.gov (United States)

    Tuura, Brianne Marie

    2012-01-01

    This dissertation examines the personal transformation of an American teacher as she becomes aware of the social, political, and economic tensions that exist within the American school system and the affects these tensions have on her ability to teach. As the researcher becomes more aware of power structures surrounding her, the reader is enabled…

  20. An Investigation of Corrosion Mitigation Strategies for Aging Post-Tensioned Cables

    Science.gov (United States)

    2017-01-01

    for Aging Post- Tensioned Cables Ernest L. Miller, Barry C. White, Richard W. Haskins, Robert M. Ebeling, and James A. Evans Information Technology...approach walls) using post- tensioning (PT) seven-wire strand cables is a common approach. In the Portland District, for example, 10% of the projects...hydraulic structures by post- tensioned ground anchorage, appreciable loss of capacity in seven-wire strand cables due to corrosion is a reason for concern

  1. An Investigation of Corrosion Mitigation Strategies for Aging Post Tensioned Cables

    Science.gov (United States)

    2017-01-01

    for Aging Post- Tensioned Cables Ernest L. Miller, Barry C. White, Richard W. Haskins, Robert M. Ebeling, and James A. Evans Information Technology...approach walls) using post- tensioning (PT) seven-wire strand cables is a common approach. In the Portland District, for example, 10% of the projects...hydraulic structures by post- tensioned ground anchorage, appreciable loss of capacity in seven-wire strand cables due to corrosion is a reason for concern

  2. Anterior cruciate ligament graft tensioning. Is the maximal sustained one-handed pull technique reproducible?

    Directory of Open Access Journals (Sweden)

    Hirpara Kieran M

    2011-07-01

    Full Text Available Abstract Background Tensioning of anterior cruciate ligament (ACL reconstruction grafts affects the clinical outcome of the procedure. As yet, no consensus has been reached regarding the optimum initial tension in an ACL graft. Most surgeons rely on the maximal sustained one-handed pull technique for graft tension. We aim to determine if this technique is reproducible from patient to patient. Findings We created a device to simulate ACL reconstruction surgery using Ilizarov components and porcine flexor tendons. Six experienced ACL reconstruction surgeons volunteered to tension porcine grafts using the device to see if they could produce a consistent tension. None of the surgeons involved were able to accurately reproduce graft tension over a series of repeat trials. Conclusions We conclude that the maximal sustained one-handed pull technique of ACL graft tensioning is not reproducible from trial to trial. We also conclude that the initial tension placed on an ACL graft varies from surgeon to surgeon.

  3. Anterior cruciate ligament graft tensioning. Is the maximal sustained one-handed pull technique reproducible?

    LENUS (Irish Health Repository)

    O'Neill, Barry J

    2011-07-20

    Abstract Background Tensioning of anterior cruciate ligament (ACL) reconstruction grafts affects the clinical outcome of the procedure. As yet, no consensus has been reached regarding the optimum initial tension in an ACL graft. Most surgeons rely on the maximal sustained one-handed pull technique for graft tension. We aim to determine if this technique is reproducible from patient to patient. Findings We created a device to simulate ACL reconstruction surgery using Ilizarov components and porcine flexor tendons. Six experienced ACL reconstruction surgeons volunteered to tension porcine grafts using the device to see if they could produce a consistent tension. None of the surgeons involved were able to accurately reproduce graft tension over a series of repeat trials. Conclusions We conclude that the maximal sustained one-handed pull technique of ACL graft tensioning is not reproducible from trial to trial. We also conclude that the initial tension placed on an ACL graft varies from surgeon to surgeon.

  4. Stress measurement and bolt tensioning by ultrasonic methods

    International Nuclear Information System (INIS)

    Smith, J.F.; Greiner, J.D.

    1980-01-01

    In the past decade, a new technique has been developed for measuring tensile stresses in solids. This ultrasonic technique has been used thus far primarily for measuring fastener tension. The precision of measurement is routinely to 2-3% and, with special care, to approx. 1%. The method is insensitive to the frictional losses which plague tensioning by torque wrench. Though the approach is relatively new, it promises a wide range of applicability

  5. Stress Measurement and Bolt Tensioning by Ultrasonic Methods

    Science.gov (United States)

    Smith, J. F.; Greiner, John D.

    1980-07-01

    In the past decade, a new technique has been developed for measuring tensile stresses in solids. This ultrasonic technique has been used thus far primarily for measuring fastener tension. The precision of measurement is routinely to 2-3% and, with special care, to ˜1%. The method is insensitive to the frictional losses which plague tensioning by torque wrench. Though the approach is relatively new, it promises a wide range of applicability.

  6. Reverse hybrid total hip arthroplasty

    DEFF Research Database (Denmark)

    Wangen, Helge; Havelin, Leif I.; Fenstad, Anne M

    2017-01-01

    Background and purpose - The use of a cemented cup together with an uncemented stem in total hip arthroplasty (THA) has become popular in Norway and Sweden during the last decade. The results of this prosthetic concept, reverse hybrid THA, have been sparsely described. The Nordic Arthroplasty....... Patients and methods - From the NARA, we extracted data on reverse hybrid THAs from January 1, 2000 until December 31, 2013. 38,415 such hips were studied and compared with cemented THAs. The Kaplan-Meier method and Cox regression analyses were used to estimate the prosthesis survival and the relative risk...

  7. Hard electroproduction of hybrid mesons

    International Nuclear Information System (INIS)

    Anikin, I.V.; LPT Universite Paris-Sud, Orsay; Szymanowski, L.; Teryaev, O.V.; ); Wallon, S.

    2005-01-01

    We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC = 1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e. as 1/Q 2 . This is due to the non-vanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in as and we explore the consequences of fixing the renormalization scale ambiguity through the BLM procedure. (author)

  8. Transitional Failure of Carbon Nanotube Systems under a Combination of Tension and Torsion

    OpenAIRE

    Jeong, Byeong-Woo

    2012-01-01

    Transitional failure envelopes of single- and double-walled carbon nanotubes under combined tension-torsion are predicted using classical molecular dynamics simulations. The observations reveal that while the tensile failure load decreases with combined torsion, the torsional buckling moment increases with combined tension. As a result, the failure envelopes under combined tension-torsion are definitely different from those under pure tension or torsion. In such combined loading, there is a m...

  9. Hybrid time-variant reliability estimation for active control structures under aleatory and epistemic uncertainties

    Science.gov (United States)

    Wang, Lei; Xiong, Chuang; Wang, Xiaojun; Li, Yunlong; Xu, Menghui

    2018-04-01

    Considering that multi-source uncertainties from inherent nature as well as the external environment are unavoidable and severely affect the controller performance, the dynamic safety assessment with high confidence is of great significance for scientists and engineers. In view of this, the uncertainty quantification analysis and time-variant reliability estimation corresponding to the closed-loop control problems are conducted in this study under a mixture of random, interval, and convex uncertainties. By combining the state-space transformation and the natural set expansion, the boundary laws of controlled response histories are first confirmed with specific implementation of random items. For nonlinear cases, the collocation set methodology and fourth Rounge-Kutta algorithm are introduced as well. Enlightened by the first-passage model in random process theory as well as by the static probabilistic reliability ideas, a new definition of the hybrid time-variant reliability measurement is provided for the vibration control systems and the related solution details are further expounded. Two engineering examples are eventually presented to demonstrate the validity and applicability of the methodology developed.

  10. Beef Production on Rotationally Grazed F1 Pennisetum Hybrid and ...

    African Journals Online (AJOL)

    Comparative studies of elephant grass and the F1 hybrids between the 'maiwa' cultivar of millet (Pennisetum americanum) and elephant grass (P. purpureum) indicated a superiority in quality of the hybrids. To ascertain this potential superiority animal performance was measured by estimating beef production on F1 ...

  11. Optimization of hybrid system (wind-solar energy) for pumping water ...

    African Journals Online (AJOL)

    This paper presents an optimization method for a hybrid (wind-solar) autonomous system designed for pumping water. This method is based on mathematical models demonstrated for the analysis and control of the performance of the various components of the hybrid system. These models provide an estimate of ...

  12. Polyelectrolyte mediated nano hybrid particle as a nano-sensor with outstandingly amplified specificity and sensitivity for enzyme free estimation of cholesterol.

    Science.gov (United States)

    Chebl, Mazhar; Moussa, Zeinab; Peurla, Markus; Patra, Digambara

    2017-07-01

    As a proof of concept, here it is established that curcumin integrated chitosan oligosaccharide lactate (COL) self-assembles on silica nanoparticle surface to form nano hybrid particles (NHPs). These NHPs have size in the ranges of 25-35nm with silica nanoparticle as its core and curcumin-COL as outer layer having thickness of 4-8nm. The fluorescence intensity of these NHPs are found to be quenched and emission maximum is ~50nm red shifted compared to free curcumin implying inner filter effect and/or homo-FRET between curcumin molecules present on the surface of individual nano hybrid particle. Although fluorescence of free curcumin is remarkably quenched by Hg 2+ /Cu 2+ ions due to chelation through keto-enol form, the fluorescence of NHPs is unaffected by Hg 2+ /Cu 2+ ion that boosts analytical selectivity. The fluorescence intensity is outstandingly enhanced in the presence of cholesterol but is not influenced by ascorbic acid, uric acid, glucose, albumin, lipid and other potential interfering substances that either obstruct during enzymatic reaction or affect fluorescence of free curcumin. Thus, NHPs outstandingly improve analytical specificity, selectivity and sensitivity during cholesterol estimation compared to free curcumin. The interaction between cholesterol and NHPs is found to be a combination of ground state electrostatic interaction through the free hydroxyl group of cholesterol along with hydrophobic interaction between NHPs and cholesterol and excited state interaction. The proposed cholesterol biosensor illustrates a wider linear dynamic range, 0.002-10mmolL -1 , (upper limit is due to lack of solubility of cholesterol) needed for biomedical application and better than reported values during enzymatic reaction. In addition, the NHPs are found to be photo-stable potentially making it suitable for simple, quick and cost-effective cholesterol estimation and opening an alternative approach other than enzymatic reaction using nano hybrid structure to

  13. Probabilistic Wind Power Forecasting with Hybrid Artificial Neural Networks

    DEFF Research Database (Denmark)

    Wan, Can; Song, Yonghua; Xu, Zhao

    2016-01-01

    probabilities of prediction errors provide an alternative yet effective solution. This article proposes a hybrid artificial neural network approach to generate prediction intervals of wind power. An extreme learning machine is applied to conduct point prediction of wind power and estimate model uncertainties...... via a bootstrap technique. Subsequently, the maximum likelihood estimation method is employed to construct a distinct neural network to estimate the noise variance of forecasting results. The proposed approach has been tested on multi-step forecasting of high-resolution (10-min) wind power using...... actual wind power data from Denmark. The numerical results demonstrate that the proposed hybrid artificial neural network approach is effective and efficient for probabilistic forecasting of wind power and has high potential in practical applications....

  14. Density and surface tension of high-temperature stratifying mixtures of alkali metal bromides and lithium fluoride

    International Nuclear Information System (INIS)

    Rukavishnikova, I.V.; Lokett, V.N.; Burukhin, A.S.; Stepanov, V.P.

    2006-01-01

    The density and interphase tension of molten mixtures of lithium fluoride with potassium, rubidium, and cesium bromides were measured over the temperature range 1120-1320 K in the region of limited mutual solubility by the hydrostatic weighing and meniscus weight methods. The dependences of properties on the size ratio between the mixed ions were determined. The critical order parameters for systems with the predominantly ionic character of interparticle interactions were estimated [ru

  15. Carbonic anhydrase inhibition increases retinal oxygen tension and dilates retinal vessels

    DEFF Research Database (Denmark)

    Pedersen, Daniella Bach; Koch Jensen, Peter; la Cour, Morten

    2005-01-01

    Carbonic anhydrase inhibitors (CAIs) increase blood flow in the brain and probably also in the optic nerve and retina. Additionally they elevate the oxygen tension in the optic nerve in the pig. We propose that they also raise the oxygen tension in the retina. We studied the oxygen tension in the...... in the pig retina and optic nerve before and after dorzolamide injection. Also the retinal vessel diameters during carbonic anhydrase inhibition were studied....

  16. Caregiving, perceptions of maternal favoritism, and tension among siblings.

    Science.gov (United States)

    Suitor, J Jill; Gilligan, Megan; Johnson, Kaitlin; Pillemer, Karl

    2014-08-01

    Studies of later-life families have revealed that sibling tension often increases in response to parents' need for care. Both theory and research on within-family differences suggest that when parents' health declines, sibling relations may be affected by which children assume care and whether siblings perceive that the parent favors some offspring over others. In the present study, we explore the ways in which these factors shape sibling tension both independently and in combination during caregiving. In this article, we use data collected from 450 adult children nested within 214 later-life families in which the offspring reported that their mothers needed care within 2 years prior to the interview. Multilevel analyses demonstrated that providing care and perceiving favoritism regarding future caregiving were associated with sibling tension following mothers' major health events. Further, the effects of caregiving on sibling tension were greater when perceptions of favoritism were also present. These findings shed new light on the conditions under which adult children are likely to experience high levels of sibling tension during caregiving. Understanding these processes is important because siblings are typically the individuals to whom caregivers are most likely to turn for support when assuming care of older parents, yet these relationships are often a major source of interpersonal stress. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Corrosion characteristics of unprotected post-tensioning strands under stress : [summary].

    Science.gov (United States)

    2014-05-01

    Post tensioned concrete is used in many Florida : transportation structures, many of which are : exposed to fresh or salt water. The steel strands : that supply the tension are encased in a plastic : duct which is later filled with grout, so the stra...

  18. Impact of fusion-fission hybrids on world nuclear future

    International Nuclear Information System (INIS)

    Abdel-Khalik, S.I.; Jansen, P.; Kessler, G.; Klumpp, P.

    1981-01-01

    An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been: (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources with or without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrids are coupled to the breeders. The results also indicate that from a resource standpoint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

  19. Impact of fusion-fission hybrids on world nuclear future

    International Nuclear Information System (INIS)

    Abdel-Khalik, S.I.

    1980-01-01

    An investigation has been conducted to examine the impact of fusion-fission hybrids on world nuclear future. The primary objectives of this investigation have been (1) to determine whether hybrids can allow us to meet the projected nuclear component of the world energy demand within current estimates of uranium resources with or without fast breeders, and (2) to identify the preferred hybrid concept from a resource standpoint. The results indicate that hybrids have the potential to lower the world uranium demand to values well below the resource base. However, the time window for hybrid introduction is quite near and narrow (2000-2020). If historical market penetration rates are assumed, the demand will not be met within the resource base unless hybrides are coupled to the breeders. The results also indicate that from a resource standpaint hybrids which breed their own tritium and have a low blanket energy multiplication are preferable. (orig.) [de

  20. Hybrid Feedforward-Feedback Noise Control Using Virtual Sensors

    Science.gov (United States)

    Bean, Jacob; Fuller, Chris; Schiller, Noah

    2016-01-01

    Several approaches to active noise control using virtual sensors are evaluated for eventual use in an active headrest. Specifically, adaptive feedforward, feedback, and hybrid control structures are compared. Each controller incorporates the traditional filtered-x least mean squares algorithm. The feedback controller is arranged in an internal model configuration to draw comparisons with standard feedforward control theory results. Simulation and experimental results are presented that illustrate each controllers ability to minimize the pressure at both physical and virtual microphone locations. The remote microphone technique is used to obtain pressure estimates at the virtual locations. It is shown that a hybrid controller offers performance benefits over the traditional feedforward and feedback controllers. Stability issues associated with feedback and hybrid controllers are also addressed. Experimental results show that 15-20 dB reduction in broadband disturbances can be achieved by minimizing the measured pressure, whereas 10-15 dB reduction is obtained when minimizing the estimated pressure at a virtual location.

  1. Creep and threshold tension in aluminum-matrix composite with short fibers obtained by hot pressing

    International Nuclear Information System (INIS)

    Moreno, M.F; Gonzalez Oliver, C.R.J

    2004-01-01

    An aluminum matrix composite reinforced with 5% vol. of short fibers of silicon carbide and un-reinforced matrix, produced by pulvimetallurgy (PM) were studied using creep compression at different deformation speeds and in the range of 300 o C to 500 o C. The creep curve of both materials showed the typical behavior of a material with threshold tension τ 0 ; with an estimate value of 6.31MPa for the matrix at 400 o C and 6.43, 8.76 and 11MPa at 350, 400 and 450 o C respectively for the composite. The τ 0 was shown to obey a thermally activated mechanism whose energy is about 17 kJ/mol. Nanometric particles of aluminum oxide were scattered throughout the matrix and the composite, arising from the inevitable film of oxides and hydroxides formed in the metallic powder. The exponent of power-law creep occurs in the values of n = 4.3 to 4.85 by reducing the tension to an effective value τ-τ 0 , corresponding to a drilling fault in both materials. In the composite, the activation energy was estimated at 167 to 125 kJ/mol, close to the self- diffusion enthalpy of the pure aluminum at 143.4 kJ/mol so that the creep process in the composite is controlled exclusively by the deformation of the matrix (CW)

  2. Determining and optimizing effective factors in laser irradiation on skin tensional strength using a hybrid DOE and DEA approach

    International Nuclear Information System (INIS)

    Bashiri, M.; Dehghan, E.; Mottaghian, F.; Amjadi, A.

    2010-01-01

    We investigated the characteristic of a suitable irradiation on skin's tensional strength using design of experiments. The experiments in this research are designed in two phases and data envelopment analysis is used for performance measurement of each phase. Material and Methods: Samples were provided from pleura as surface tissue made of collagen and elastin fibers. In each experiment, the sample was stretched before and after irradiation. Variation of the sample length was measured. Then force-length data were plotted and the slope of the fitted line was calculated. Variation in these slopes was used as a criterion to determine tissue strength variation after laser irradiation. Furthermore, the output oriented data envelopment analysis model by variable return to scale was used to examine performance of the designed experiments for each phase. Results: Results of the first phase experiments showed that the main effect of time duration was significant; but this was not the case for beam radius. Regarding polarization, only its interaction effect with time duration was significant. Results of the second phase indicated that laser irradiation with parallel polarization for 10 seconds caused a greater increase in tensional strength. Resultant efficiencies of applying data envelopment analysis showed that the first phase experiments were more efficient. Discussion and Conclusions: This research has combined data envelopment analysis and design of experiments to investigate the effects of laser on skin elasticity. Comparing the results of the two phases indicates that it is more efficient to use the experimental design of phase 1 in our experiment. So for similar future studies, we suggest using more levels for experiments of phase 1 instead of doing the experimental design in two phases.

  3. Determining and Optimizing Effective Factors in Laser Irradiation on Skin Tensional Strength using a Hybrid DOE and DEA Approach

    Directory of Open Access Journals (Sweden)

    Mehdi Bashiri

    2010-03-01

    Full Text Available Introduction: We investigated the characteristic of a suitable irradiation on skin's tensional strength using design of experiments (DOE. The experiments in this research are designed in two phases and data envelopment analysis (DEA is used for performance measurement of each phase. Material and Methods: Samples were provided from pleura as surface tissue made of collagen and elastin fibers. In each experiment, the sample was stretched before and after irradiation. Variation of the sample length was measured. Then force-length data were plotted and the slope of the fitted line was calculated. Variation in these slopes was used as a criterion to determine tissue strength variation after laser irradiation. Furthermore, the output oriented DEA model by variable return to scale was used to examine performance of the designed experiments for each phase. Results: Results of the first phase experiments showed that the main effect of time duration was significant; but this was not the case for beam radius. Regarding polarization, only its interaction effect with time duration was significant. Results of the second phase indicated that laser irradiation with parallel polarization for 10 seconds caused a greater increase in tensional strength. Resultant efficiencies of applying DEA showed that the first phase experiments were more efficient. Discussion and Conclusions: This research has combined DEA and DOE to investigate the effects of laser on skin elasticity. Comparing the results of the two phases indicates that it is more efficient to use the experimental design of phase 1 in our experiment. So for similar future studies, we suggest using more levels for experiments of phase 1 instead of doing the experimental design in two phases.

  4. A Hybrid Extended Kalman Filter as an Observer for a Pot-Electro-Magnetic Actuator

    International Nuclear Information System (INIS)

    Schmidt, Simon; Mercorelli, Paolo

    2017-01-01

    This paper deals with an application in which a hybrid extended Kalman Filter (HEKF) is used to estimate state variables in a U-shaped electro-magnetic actuator to be used in mechanical systems. In this context a hybrid Kalman Filter is the one which switches between different models. The paper proposes a hybrid model for an extended Kalman Filter to be used as an observer to estimate the state and to control the force of the actuator. Applications include position, velocity and force control in automotive, engine and manufacturing systems. This work is focused on the estimation of state variables of the actuator. Simulated results show the effectiveness of the proposed approach. (paper)

  5. Separation anxiety: Stress, tension and cytokinesis

    International Nuclear Information System (INIS)

    Mohan, Krithika; Iglesias, Pablo A.; Robinson, Douglas N.

    2012-01-01

    Cytokinesis, the physical separation of a mother cell into two daughter cells, progresses through a series of well-defined changes in morphology. These changes involve distinct biochemical and mechanical processes. Here, we review the mechanical features of cells during cytokinesis, discussing both the material properties as well as sources of stresses, both active and passive, which lead to the observed changes in morphology. We also describe a mechanosensory feedback control system that regulates protein localization and shape progression during cytokinesis. -- Highlights: ► Cytokinesis progresses through three distinct mechanical phases. ► Cortical tension initially resists deformation of mother cell. ► Late in cytokinesis, cortical tension provides stress, enabling furrow ingression. ► A mechanosensory feedback control system regulates cytokinesis.

  6. Some remarks on the solid surface tension determination from contact angle measurements

    Energy Technology Data Exchange (ETDEWEB)

    Zdziennicka, Anna; Szymczyk, Katarzyna; Krawczyk, Joanna; Jańczuk, Bronisław, E-mail: bronislaw.janczuk@poczta.umcs.lublin.pl

    2017-05-31

    Graphical abstract: Surface tension of PE, nylon 6 and quartz from different approaches to the interface tension. - Highlights: • New values of water and formamide surface tension components were established. • Quartz surface tension depends on its crystal face. • Usefulness of different approaches for solid surface tension determination was tested. - Abstract: The measurements of water, formamide and diiodomethane contact angle (θ) on polytetrafluoroethylene (PTFE), polyethylene (PE), polymethyl methacrylate (PMMA), nylon 6, quartz and silica were performed. Based on the θ values of these liquids obtained on PTFE, the Lifshitz-van der Waals and acid-base and/or dispersion and polar components of their surface tension (ST) were determined. In turn, the θ values for water, formamide and diiodomethane on PMMA were applied to calculate the electron-acceptor and electron-donor parameters of the Lewis acid-base component of the formamide ST. For this calculation the same values of the electron-acceptor and electron-donor parameters for water ST were used. Taking into account the values of components and parameters of water, formamide and diiodomethane ST obtained by us, van Oss et al. and from the water(formamide)-n-alkane and water-diiodomethane interface tension, the components and parameters of studied solids ST were calculated. To this end different approaches to the interface tension were considered. The obtained values were compared with those in the literature. It was concluded that for determination of solid ST components and parameters, those of water, formamide and diiodomethane ST obtained from the θ measurements on the model solids should be used.

  7. Apparatus producing constant cable tension for intermittent demand

    Science.gov (United States)

    Lauritzen, Ted

    1985-01-01

    The disclosed apparatus produces constant tension in superconducting electrical cable, or some other strand, under conditions of intermittent demand, as the cable is unreeled from a reel or reeled thereon. The apparatus comprises a pivotally supported swing frame on which the reel is rotatably supported, a rotary motor, a drive train connected between the motor and the reel and including an electrically controllable variable torque slip clutch, a servo transducer connected to the swing frame for producing servo input signals corresponding to the position thereof, a servo control system connected between the transducer and the clutch for regulating the torque transmitted by the clutch to maintain the swing frame in a predetermined position, at least one air cylinder connected to the swing frame for counteracting the tension in the cable, and pressure regulating means for supplying a constant air pressure to the cylinder to establish the constant tension in the cable, the servo system and the clutch being effective to produce torque on the reel in an amount sufficient to provide tension in the cable corresponding to the constant force exerted by the air cylinder. The drive train also preferably includes a fail-safe brake operable to its released position by electrical power in common with the servo system, for preventing rotation of the reel if there is a power failure. A shock absorber and biasing springs may also be connected to the swing frame, such springs biasing the frame toward its predetermined position. The tension in the cable may be measured by force measuring devices engageable with the bearings for the reel shaft, such bearings being supported for slight lateral movement. The reel shaft is driven by a Shmidt coupler which accommodates such movement.

  8. Apparatus producing constant cable tension for intermittent demand

    International Nuclear Information System (INIS)

    Lauritzen, T.

    1985-01-01

    The disclosed apparatus produces constant tension in superconducting electrical cable, or some other strand, under conditions of intermittent demand, as the cable is unreeled from a reel or reeled thereon. The apparatus comprises a pivotally supported swing frame on which the reel is rotatably supported, a rotary motor, a drive train connected between the motor and the reel and including an electrically controllable variable torque slip clutch, a servo transducer connected to the swing frame for producing servo input signals corresponding to the position thereof, a servo control system connected between the transducer and the clutch for regulating the torque transmitted by the clutch to maintain the swing frame in a predetermined position, at least one air cylinder connected to the swing frame for counteracting the tension in the cable, and pressure regulating means for supplying a constant air pressure to the cylinder to establish the constant tension in the cable, the servo system and the clutch being effective to produce torque on the reel in an amount sufficient to provide tension in the cable corresponding to the constant force exerted by the air cylinder. The drive train also preferably includes a fail-safe brake operable to its released position by electrical power in common with the servo system, for preventing rotation of the reel if there is a power failure. A shock absorber and biasing springs may also be connected to the swing frame, such springs biasing the frame toward its predetermined position. The tension in the cable may be measured by force measuring devices engageable with the bearings for the reel shaft, such bearings being supported for slight lateral movement. The reel shaft is driven by a Shmidt coupler which accommodates such movement

  9. Post-tensioned Discrete Concrete Elements Developed For Free-form Construction

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole; Larsen, Niels Martin; Pigram, Dave

    2015-01-01

    This paper presents a method for the construction of non-uniform precast concrete shell structures from unique parts. A novel method of discontinuous post-tensioning is introduced which allows tension to be taken through the connections. This increases the formal possibilities of the system beyon...

  10. Improving corrosion resistance of post-tensioned substructures emphasizing high performance grouts

    Science.gov (United States)

    Schokker, Andrea Jeanne

    The use of post-tensioning in bridges can provide durability and structural benefits to the system while expediting the construction process. When post-tensioning is combined with precast elements, traffic interference can be greatly reduced through rapid construction. Post-tensioned concrete substructure elements such as bridge piers, hammerhead bents, and straddle bents have become more prevalent in recent years. Chloride induced corrosion of steel in concrete is one of the most costly forms of corrosion each year. Coastal substructure elements are exposed to seawater by immersion or spray, and inland bridges may also be at risk due to the application of deicing salts. Corrosion protection of the post-tensioning system is vital to the integrity of the structure because loss of post-tensioning can result in catastrophic failure. Documentation for durability design of the grout, ducts, and anchorage systems is very limited. The objective of this research is to evaluate the effectiveness of corrosion protection measures for post-tensioned concrete substructures by designing and testing specimens representative of typical substructure elements using state-of-the-art practices in aggressive chloride exposure environments. This was accomplished through exposure testing of twenty-seven large-scale beam specimens and ten large-scale column specimens. High performance grout for post-tensioning tendon injection was also developed through a series of fresh property tests, accelerated exposure tests, and a large-scale pumping test to simulate field conditions. A high performance fly ash grout was developed for applications with small vertical rises, and a high performance anti-bleed grout was developed for applications involving large vertical rises such as tall bridge piers. Long-term exposure testing of the beam and column specimens is ongoing, but preliminary findings indicate increased corrosion protection with increasing levels of post-tensioning, although traditional

  11. Exotic hybrid mesons in hard electroproduction

    International Nuclear Information System (INIS)

    Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

    2005-01-01

    We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC =1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e., as 1/Q 2 . This is due to the nonvanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy-momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in α S and we explore the consequences of fixing the renormalization scale ambiguity through the Brodsky-Lepage-Mackenzie (BLM) procedure. We study the particular case where the hybrid meson decays through a πη meson pair. We discuss the πη generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of π and η mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very high energy, in the diffractive limit where a QCD Odderon exchange mechanism should dominate. The conclusion of our study is that hard electroproduction is a promising way to study exotic hybrid mesons, in particular, at JLAB, HERA (HERMES), or CERN (Compass)

  12. Social inequality as a factor of social tensions in Russian society

    Directory of Open Access Journals (Sweden)

    A. A. Oseev

    2014-01-01

    Full Text Available Based on this study the author concludes that “the latent and open social tensions... in Russian society today is quite high”, “clearly defined trend towards further improving it”, and to the deterioration of the social situation in the country and rising social tensions it “could lead to a sharp (abrupt increase in overt signs of social tensions and the development of its pre-crisis aside, and then the crisis situation”.

  13. Dynamic surface tension measurements of ionic surfactants using maximum bubble pressure tensiometry

    Science.gov (United States)

    Ortiz, Camilla U.; Moreno, Norman; Sharma, Vivek

    Dynamic surface tension refers to the time dependent variation in surface tension, and is intimately linked with the rate of mass transfer of a surfactant from liquid sub-phase to the interface. The diffusion- or adsorption-limited kinetics of mass transfer to interfaces is said to impact the so-called foamability and the Gibbs-Marangoni elasticity of surfaces. Dynamic surface tension measurements carried out with conventional methods like pendant drop analysis, Wilhelmy plate, etc. are limited in their temporal resolution (>50 ms). In this study, we describe design and application of maximum bubble pressure tensiometry for the measurement of dynamic surface tension effects at extremely short (1-50 ms) timescales. Using experiments and theory, we discuss the overall adsorption kinetics of charged surfactants, paying special attention to the influence of added salt on dynamic surface tension.

  14. Aversive tension in female adolescents with Anorexia Nervosa: a controlled ecological momentary assessment using smartphones.

    Science.gov (United States)

    Kolar, David R; Hammerle, Florian; Jenetzky, Ekkehart; Huss, Michael; Bürger, Arne

    2016-04-12

    Current models of Anorexia Nervosa (AN) emphasize the role of emotion regulation. Aversive tension, described as a state of intense arousal and negative valence, is considered to be a link between emotional events and disordered eating. Recent research focused only on adult patients, and mainly general emotion regulation traits were studied. However, the momentary occurrence of aversive tension, particularly in adolescents with AN, has not been previously studied. 20 female adolescents with AN in outpatient treatment and 20 healthy adolescents aged 12 to 19 years participated in an ecological momentary assessment using their smartphones. Current states of aversive tension and events were assessed hourly for two consecutive weekdays. Mean and maximum values of aversive tension were compared. Multilevel analyses were computed to test the influence of time and reported events on aversive tension. The effect of reported events on subsequent changes of aversive tension in patients with AN were additionally tested in a multilevel model. AN patients showed higher mean and maximum levels of aversive tension. In a multilevel model, reported food intake was associated with higher levels of aversive tension in the AN group, whereas reported school or sport-related events were not linked to specific states of aversive tension. After food intake, subsequent increases of aversive tension were diminished and decreases of aversive tension were induced in adolescents with AN. Aversive tension may play a substantial role in the psychopathology of AN, particular in relation with food intake. Therefore, treatment should consider aversive tension as a possible intervening variable during refeeding. Our findings encourage further research on aversive tension and its link to disordered eating. German register of clinical trials (DRKS): DRKS00005228 (Date of registration: September 2, 2013).

  15. Tensions of Corporate Social Responsibility

    DEFF Research Database (Denmark)

    Strand, Robert

    , and formally rational tools like key performance indicators (KPIs) can be developed and employed in service of the selected substantively rational ends. I show how these KPIs can serve to highlight tensions between substantively rational ends. As such, I argue the CSR bureaucracy can create a space...

  16. Biomechanics of Concussion: The Importance of Neck Tension

    Science.gov (United States)

    Jadischke, Ronald

    Linear and angular velocity and acceleration of the head are typically correlated to concussion. Despite improvements in helmet performance to reduce accelerations, a corresponding reduction in the incidence of concussion has not occurred (National Football League [NFL] 1996-present). There is compelling research that forces on and deformation to the brain stem are related to concussion. The brain stem is the center of control for respiration, blood pressure and heart rate and is the root of most cranial nerves. Injury to the brain stem is consistent with most symptoms of concussion reported in the National Football League and the National Hockey League, such as headaches, neck pain, dizziness, and blurred vision. In the Hybrid III anthropomorphic test device (ATD), the upper neck load cell is in close proximity to the human brain stem. This study found that the additional mass of a football helmet onto the Hybrid III headform increases the upper neck forces and moments in response to helmet-to-helmet impact and helmet-to-chest impacts. A new laboratory impactor device was constructed to simulate collisions using two moving Hybrid III ATDs. The impactor was used to recreate on-field collisions (n = 20) in American football while measuring head, neck and upper torso kinematics. A strong correlation between upper neck forces, upper neck power and the estimated strains and strain rates along the axis of the upper cervical spinal cord and brain stem and concussion was found. These biomechanical responses should be added to head kinematic responses for a more comprehensive evaluation of concussion.

  17. “Conyo talk”: the affirmation of hybrid identity and power in contemporary Philippine discourse

    Directory of Open Access Journals (Sweden)

    M. M. Garvida

    2013-01-01

    Full Text Available The Philippine linguistic and cultural phenomenon “coño talk” (a mix of predominantly Spanish and English with tagalog is a type of discourse that purportedly identifies and differentiates people of ‘power’ from the common masses, and arose from the impact of Spanish and American colonization. This paper examines how web discussion forums embody these social tensions through ethnomethodological discourse analysis (Tate 2007 and Bhabha’s (1990 third space to demonstrate the patent cultural hybridity in the Philippine society. Analysis demonstrates how participants as conyo speakers position themselves, and discusses the socio-cultural implications of these presentations. Results show participants instinctively and/or intentionally use this type of discourse and position themselves to construct or establish their own identities. Implications for cultural hybridity and the constraining, facilitating or subjectification effects of this type of discourse on Philippine society are discussed

  18. Update on normal tension glaucoma

    Directory of Open Access Journals (Sweden)

    Jyotiranjan Mallick

    2016-01-01

    Full Text Available Normal tension glaucoma (NTG is labelled when typical glaucomatous disc changes, visual field defects and open anterior chamber angles are associated with intraocular pressure (IOP constantly below 21 mmHg. Chronic low vascular perfusion, Raynaud's phenomenon, migraine, nocturnal systemic hypotension and over-treated systemic hypertension are the main causes of normal tension glaucoma. Goldmann applanation tonometry, gonioscopy, slit lamp biomicroscopy, optical coherence tomography and visual field analysis are the main tools of investigation for the diagnosis of NTG. Management follows the same principles of treatment for other chronic glaucomas: To reduce IOP by a substantial amount, sufficient to prevent disabling visual loss. Treatment is generally aimed to lower IOP by 30% from pre-existing levels to 12-14 mmHg. Betaxolol, brimonidine, prostaglandin analogues, trabeculectomy (in refractory cases, systemic calcium channel blockers (such as nifedipine and 24-hour monitoring of blood pressure are considered in the management of NTG. The present review summarises risk factors, causes, pathogenesis, diagnosis and management of NTG.

  19. Adaptive measurement selection for progressive damage estimation

    Science.gov (United States)

    Zhou, Wenfan; Kovvali, Narayan; Papandreou-Suppappola, Antonia; Chattopadhyay, Aditi; Peralta, Pedro

    2011-04-01

    Noise and interference in sensor measurements degrade the quality of data and have a negative impact on the performance of structural damage diagnosis systems. In this paper, a novel adaptive measurement screening approach is presented to automatically select the most informative measurements and use them intelligently for structural damage estimation. The method is implemented efficiently in a sequential Monte Carlo (SMC) setting using particle filtering. The noise suppression and improved damage estimation capability of the proposed method is demonstrated by an application to the problem of estimating progressive fatigue damage in an aluminum compact-tension (CT) sample using noisy PZT sensor measurements.

  20. Chromosomal rearrangements and gene flow over time in an inter-specific hybrid zone of the Sorex araneus group.

    Science.gov (United States)

    Yannic, G; Basset, P; Hausser, J

    2009-06-01

    Most hybrid zones have existed for hundreds or thousands of years but have generally been observed for only a short time period. Studies extending over periods long enough to track evolutionary changes in the zones or assess the ultimate outcome of hybridization are scarce. Here, we describe the evolution over time of the level of genetic isolation between two karyotypically different species of shrews (Sorex araneus and Sorex antinorii) at a hybrid zone located in the Swiss Alps. We first evaluated hybrid zone movement by contrasting patterns of gene flow and changes in cline parameters (centre and width) using 24 microsatellite loci, between two periods separated by 10 years apart. Additionally, we tested the role of chromosomal rearrangements on gene flow by analysing microsatellite loci located on both rearranged and common chromosomes to both species. We did not detect any movement of the hybrid zone during the period analysed, suggesting that the zone is a typical tension zone. However, the gene flow was significantly lower among the rearranged than the common chromosomes for the second period, whereas the difference was only marginally significant for the first period. This further supports the role of chromosomal rearrangements on gene flow between these taxa.

  1. [Cognitive behavioral therapy for tension-type headache: a case report].

    Science.gov (United States)

    Salman, İsmail Barış; Sertel Berk, Hanife Özlem

    2017-10-01

    Tension-type headache has a very high socioeconomic impact, and its lifetime prevalence is reported to be between 30% and 78% in different studies. It is widely acknowledged that noninvasive management with a multidisciplinary approach should be considered for the treatment of tension-type headache. Cognitive behavioral therapy and relaxation exercises are efficient techniques. This article illustrates the application of a cognitive behavioral therapy protocol enhanced with progressive muscle stretching and relaxation exercises in the treatment of chronic tension-type headache via a case report. Our patient had an ongoing headache for 6 years when he was referred to us by the department of psychiatry. After 10 cognitive behavioral therapy sessions, the patient had learned to notice muscle tension and relax the muscles as well as to recognize and express his emotions in a better way. He became aware of automatic thoughts and learned to find alternative thoughts. Headache severity decreased, and he was able to increase participation in daily life activities.

  2. Modeling and characterization of strengthened concrete tension members

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg; Stang, Henrik

    2011-01-01

    The structural potential for cracking of externally strengthened concrete tension members, can be predicted with three parameters, describing the structural cracking potential based on fracture mechanical properties of the of concrete and interface between concrete and strengthening medium....... With these parameters, it is possible to design reinforcement and obtain a required cracking behavior of a given structure. Design recommendations for single and multiple cracking of the tension specimen are given in terms of fracture mechanical parameters, and a structural stiffness parameter....

  3. Stride-related rein tension patterns in walk and trot in the ridden horse.

    Science.gov (United States)

    Egenvall, Agneta; Roepstorff, Lars; Eisersiö, Marie; Rhodin, Marie; van Weeren, René

    2015-12-30

    The use of tack (equipment such as saddles and reins) and especially of bits because of rein tension resulting in pressure in the mouth is questioned because of welfare concerns. We hypothesised that rein tension patterns in walk and trot reflect general gait kinematics, but are also determined by individual horse and rider effects. Six professional riders rode three familiar horses in walk and trot. Horses were equipped with rein tension meters logged by inertial measurement unit technique. Left and right rein tension data were synchronized with the gait. Stride split data (0-100 %) were analysed using mixed models technique to elucidate the left/right rein and stride percentage interaction, in relation to the exercises performed. In walk, rein tension was highest at hindlimb stance. Rein tension was highest in the suspension phase at trot, and lowest during the stance phase. In rising trot there was a significant difference between the two midstance phases, but not in sitting trot. When turning in trot there was a significant statistical association with the gait pattern with the tension being highest in the inside rein when the horse was on the outer fore-inner hindlimb diagonal. Substantial between-rider variation was demonstrated in walk and trot and between-horse variation in walk. Biphasic rein tensions patterns during the stride were found mainly in trot.

  4. Modelo biopsicossocial e formulação comportamental: compreendendo a cefaléia do tipo tensional Modelo biopsicosocial y formulación comportamental: comprendiendo la cefalea del tipo tensional The bio-psychosocial model and behavioral formulation: understanding the tension-type headache

    Directory of Open Access Journals (Sweden)

    Adriana Mayon Neiva Flores

    2008-03-01

    Full Text Available A cefaléia do tipo tensional constitui um tipo freqüente de dor de cabeça, que tende a ocasionar uma série de comportamentos de evitação, com prejuízos físicos, sociais e psicológicos aos indivíduos afetados. O presente trabalho descreve algumas contribuições do modelo biopsicossocial de saúde para a compreensão da cefaléia do tipo tensional, descreve os tratamentos mais freqüentemente oferecidos e discute as vantagens de modalidades terapêuticas que utilizam a formulação comportamental. Destaca-se a relevância da consideração de fatores psicossociais presentes nas formas mais comuns de evolução da cefaléia do tipo tensional, o que contribui para a elaboração de planos de tratamento mais eficientes e coerentes com uma proposta realmente sistêmica e idiográfica.La cefalea del tipo tensional constituye un tipo frecuente de dolor de cabeza, que tiene la tendencia a ocasionar una serie de comportamientos de evitación, con daños físicos, sociales y psicológicos a los individuos afectados. El presente trabajo describe algunas contribuciones del modelo biopsicosocial de salud para la comprensión de la cefalea del tipo tensional, describe los tratamientos más frecuentemente ofrecidos y discute las ventajas de modalidades terapéuticas que utilizan la formulación comportamental. Se destaca la relevancia de la consideración de factores psicosociales presentes en las formas más comunes de evolución de la cefalea del tipo tensional, lo que contribuye para la elaboración de planes de tratamiento más eficientes y coherentes con una propuesta realmente sistémica e idiográfica.Tension-type headache are a frequent source of complaints in health assistance units. It tends to cause avoidance behaviors with adverse consequences in physical, psychological and social aspects. Contributions from the Bio-Psychosocial perspective are described for a better understanding of the tension-type headache problem. Study also analyzes

  5. Kalman Filtered Bio Heat Transfer Model Based Self-adaptive Hybrid Magnetic Resonance Thermometry.

    Science.gov (United States)

    Zhang, Yuxin; Chen, Shuo; Deng, Kexin; Chen, Bingyao; Wei, Xing; Yang, Jiafei; Wang, Shi; Ying, Kui

    2017-01-01

    To develop a self-adaptive and fast thermometry method by combining the original hybrid magnetic resonance thermometry method and the bio heat transfer equation (BHTE) model. The proposed Kalman filtered Bio Heat Transfer Model Based Self-adaptive Hybrid Magnetic Resonance Thermometry, abbreviated as KalBHT hybrid method, introduced the BHTE model to synthesize a window on the regularization term of the hybrid algorithm, which leads to a self-adaptive regularization both spatially and temporally with change of temperature. Further, to decrease the sensitivity to accuracy of the BHTE model, Kalman filter is utilized to update the window at each iteration time. To investigate the effect of the proposed model, computer heating simulation, phantom microwave heating experiment and dynamic in-vivo model validation of liver and thoracic tumor were conducted in this study. The heating simulation indicates that the KalBHT hybrid algorithm achieves more accurate results without adjusting λ to a proper value in comparison to the hybrid algorithm. The results of the phantom heating experiment illustrate that the proposed model is able to follow temperature changes in the presence of motion and the temperature estimated also shows less noise in the background and surrounding the hot spot. The dynamic in-vivo model validation with heating simulation demonstrates that the proposed model has a higher convergence rate, more robustness to susceptibility problem surrounding the hot spot and more accuracy of temperature estimation. In the healthy liver experiment with heating simulation, the RMSE of the hot spot of the proposed model is reduced to about 50% compared to the RMSE of the original hybrid model and the convergence time becomes only about one fifth of the hybrid model. The proposed model is able to improve the accuracy of the original hybrid algorithm and accelerate the convergence rate of MR temperature estimation.

  6. Predicting the minimum liquid surface tension activity of pseudomonads expressing biosurfactants.

    Science.gov (United States)

    Mohammed, I U; Deeni, Y; Hapca, S M; McLaughlin, K; Spiers, A J

    2015-01-01

    Bacteria produce a variety of biosurfactants capable of significantly reducing liquid (aqueous) surface tension (γ) with a range of biological roles and biotechnological uses. To determine the lowest achievable surface tension (γMin ), we tested a diverse collection of Pseudomonas-like isolates from contaminated soil and activated sludge and identified those expressing biosurfactants by drop-collapse assay. Liquid surface tension-reducing ability was quantitatively determined by tensiometry, with 57 isolates found to significantly lower culture supernatant surface tensions to 24·5-49·1 mN m(-1) . Differences in biosurfactant behaviour determined by foaming, emulsion and oil-displacement assays were also observed amongst isolates producing surface tensions of 25-27 mN m(-1) , suggesting that a range of structurally diverse biosurfactants were being expressed. Individual distribution identification (IDI) analysis was used to identify the theoretical probability distribution that best fitted the surface tension data, which predicted a γMin of 24·24 mN m(-1) . This was in agreement with predictions based on earlier work of published mixed bacterial spp. data, suggesting a fundamental limit to the ability of bacterial biosurfactants to reduce surface tensions in aqueous systems. This implies a biological restriction on the synthesis and export of these agents or a physical-chemical restriction on their functioning once produced. Numerous surveys of biosurfactant-producing bacteria have been conducted, but only recently has an attempt been made to predict the minimum liquid surface tension these surface-active agents can achieve. Here, we determine a theoretical minimum of 24 mN m(-1) by statistical analysis of tensiometry data, suggesting a fundamental limit for biosurfactant activity in bacterial cultures incubated under standard growth conditions. This raises a challenge to our understanding of biosurfactant expression, secretion and function, as well as

  7. Tension stiffening in partially prestressed concrete flexural members

    International Nuclear Information System (INIS)

    Oukaili, K. N.

    2000-01-01

    Concrete tensile strength is not being zero, cracking does not extend to the neutral axis as assumed in standard cracked section analysis. In addition, un cracked concrete, which exists above the crack tip in the tension zone, contributes to the stiffness of the member. This paper discusses the influence of concrete tensile stress below the neut ural axis position at the cracked section on the tension stiffening phenomenon and deflection of progressively cracking partially prestressed concrete flexural members. The computation of the neutral axis location, which takes into consideration the effect of concrete in tension, can be achieved by solving iteratively tow simultaneous equation derived from forces and moments equilibrium, strain compatibility and linear stress - strain relationship in concrete across the section depth. Once the section depth after cracking is known, it can be used to calculate the effective moment of inertia for deflection analysis. (author). 13 refs., 3 figs., 1 table

  8. Tensile behavior and tension stiffening of reinforced concrete

    International Nuclear Information System (INIS)

    Choun, Young Sun; Seo, Jeong Moon

    2001-03-01

    For the ultimate behavior analysis of containment buildings under severe accident conditions, a clear understanding of tensile behaviors of plain and reinforced concrete is necessary. Nonlinear models for tensile behaviors of concrete are also needed. This report describe following items: tensile behaviors of plain concrete, test results of reinforced concrete panels in uniaxial and biaxial tension, tension stiffening. The tensile behaviors of reinforced concrete are significantly influenced by the properties of concrete and reinforcing steel. Thus, for a more reliable evaluation of tensile behavior and ultimate pressure capacity of a reinforced or prestressed concrete containment building, an advanced concrete model which can be considered rebar-concrete interaction effects should be developed. In additions, a crack behavior analysis method and tension stiffening models, which are based on fracture mechanics, should be developed. The model should be based on the various test data from specimens considering material and sectional properties of the containment building

  9. The Investigation of the Corrosion Resistance of the Tension Clamps Skl14

    Directory of Open Access Journals (Sweden)

    Marek Pětioký

    2015-05-01

    Full Text Available At the level crossings it is possible to find the problems with the corrosion of the parts of the fastening system. These problems are especially at the rubber level crossings and in the tunnels. As a part of the thesis the problem of the corrosion of the tension clamp Skl14 of the producer Vossloh at the rubber level crossings is examined. For the purposes of the comparison the tension clamps without the corrosion protection and the tension clamps with the corrosion protection KTL were examined. As a first step the corrosion features of the tension clamps Skl14 were solved. The examination was divided into two parts. First part it was the examination according to ČSN EN ISO 9227. The samples of the tension clamps were putted into the corrosion chamber. After 1728 h the results of the corrosion impacts were not satisfied. It was decided for the second step of the examination. It was the immersion in an electrolyte solution. As a result of the paper the corrosion features of the tension clamps without the corrosion protection and with the corrosion protection are compared.

  10. Navigating the Tensions of Innovative Assessment and Pedagogy in Higher Education

    Directory of Open Access Journals (Sweden)

    Jennifer Lock

    2018-04-01

    Full Text Available Innovative practice in a classroom adds challenges and tensions to programs and institutional structures in higher education. With the recent emphasis on curricula reform, there is a great focus on assessment and pedagogical practices to support student learning. To illustrate the tensions arising from these efforts, we present four pedagogical and assessment innovation approaches using both Shulman’s (2005 Signature Pedagogies and Tatar’s (2007 Design Tensions frameworks. The four approaches include problem-based learning, game-based learning, case-based learning, and technology-enhanced learning. A narrative for each approach examines and addresses tensions using Shulman’s (2005 surface, deep and implicit structures. We argue that there is an interconnected complexity and conflicting visions among the micro- (e.g., classroom or practicum, meso- (e.g., program, and macro- (e.g., institution levels. We acknowledge that dynamic tensions continually exist and needs to be thoughtfully navigated in support of innovative assessment and pedagogies in higher education. Dans l’enseignement supérieur, les pratiques innovatrices en salle de classe ajoutent des défis et des tensions aux programmes et aux structures institutionnelles. Suite à l’importance accrue récemment attachée à la réforme des programmes d’études, l’accent est mis sur l’évaluation et les pratiques pédagogiques pour soutenir l’apprentissage des étudiants. Afin d’illustrer les tensions qui découlent de ces efforts, nous présentons quatre approches de pédagogie et d’évaluation innovatrices qui font appel à la fois aux cadres de Shulman, Signature Pedagogies (2005, et à ceux de Tatar, Design Tensions (2007. Les quatre approches comprennent l’apprentissage par problèmes, l’apprentissage fondé sur le jeu, l’apprentissage basé sur des cas et l’apprentissage amélioré par les technologies. Chaque approche est examinée et traite des tensions

  11. Managing the accountability-autonomy tensions in university research commercialisation

    OpenAIRE

    Narayan, Anil K.; Northcott, Deryl; Parker, Lee D.

    2017-01-01

    This article investigates organisational responses to emerging concerns about how accountability–autonomy tensions can be managed within the context of university research commercialisation. The findings suggest that changed expectations of university research practices, which result from the introduction of a commercialisation logic, can be managed via the homogenisation of research goals and strategies. The successful management of accountability–autonomy tensions also depends on utilising ...

  12. Comparing the Knotless Tension Band and the Traditional Stainless Steel Wire Tension Band Fixation for Medial Malleolus Fractures: A Retrospective Clinical Study

    Directory of Open Access Journals (Sweden)

    Michael W. Downey

    2016-01-01

    Full Text Available The traditional stainless steel wire tension band (WTB has been popularized for small avulsion fractures at the medial malleolus. Despite the tension band principle creating a stable construct, complications continue to arise utilizing the traditional stainless steel WTB with patients experiencing hardware irritation at the tension band site and subsequent hardware removal. Coupled with hardware irritation is fatigue failure with the wire. The goal of this investigation was to retrospectively compare this traditional wire technique to an innovative knotless tension band (KTB technique in order to decrease costly complications. A total of 107 patients were reviewed with a minimum follow-up of 1 year. Outcome measures include descriptive data, fracture classification, results through economic costs, and fixation results (including hardware status, healing status, pain status, and time to healing. The KTB group had a 13% lower true cost as compared to the WTB group while the fixation results were equivocal for the measured outcomes. Our results demonstrate that the innovative KTB is comparable to the traditional WTB while offering a lower true cost, an irritation free reduction all without the frustration of returning to the operating room for additional hardware removal, which averages approximately to $8,288.

  13. Ethical Tensions Related to Systemic Constraints: Occupational Alienation in Occupational Therapy Practice.

    Science.gov (United States)

    Durocher, Evelyne; Kinsella, Elizabeth Anne; McCorquodale, Lisa; Phelan, Shanon

    2016-09-03

    Ethical tensions arise daily in health care practice and are frequently related to health care system structures or policies. Collective case study methodology was adopted to examine ethical tensions reported by occupational therapists practicing in different settings in Southwestern Ontario, Canada. Inductive analysis involving multiple layers of coding was conducted. This article focuses on tensions related to systemic constraints. Participants reported ethical tensions related to balancing client priorities with those of health care services. Four themes related to systemic constraints were identified including imposed practices, ineffective processes, resource limitations, and lack of services. Therapists' aims could be seen to align with an "ethic of care" and were seen to be in tension in light of systemic constraints. The findings raise issues related to occupational justice, particularly related to occupational alienation in occupational therapy practice, and open conversations related to neoliberalist health care agendas. © The Author(s) 2016.

  14. The tokamak hybrid reactor

    International Nuclear Information System (INIS)

    Kelly, J.L.; Rose, R.P.

    1981-01-01

    At a time when the potential benefits of various energy options are being seriously evaluated in many countries through-out the world, it is both timely and important to evaluate the practical application of fusion reactors for their economical production of nuclear fissile fuels from fertile fuels. The fusion hybrid reactor represents a concept that could assure the availability of adequate fuel supplies for a proven nuclear technology and have the potential of being an electrical energy source as opposed to an energy consumer as are the present fuel enrichment processes. Westinghouse Fusion Power Systems Department, under Contract No. EG-77-C-02-4544 with the Department of Energy, Office of Fusion Energy, has developed a preliminary conceptual design for an early twenty-first century fusion hybrid reactor called the commercial Tokamak Hybrid Reactor (CTHR). This design was developed as a first generation commercial plant producing fissile fuel to support a significant number of client Light Water Reactor (LWR) Plants. To the depth this study has been performed, no insurmountable technical problems have been identified. The study has provided a basis for reasonable cost estimates of the hybrid plants as well as the hybrid/LWR system busbar electricity costs. This energy system can be optimized to have a net cost of busbar electricity that is equivalent to the conventional LWR plant, yet is not dependent on uranium ore prices or standard enrichment costs, since the fusion hybrid can be fueled by numerous fertile fuel resources. A nearer-term concept is also defined using a beam driven fusion driver in lieu of the longer term ignited operating mode. (orig.)

  15. Flexural Strengthening of RC Slabs Using a Hybrid FRP-UHPC System Including Shear Connector

    Directory of Open Access Journals (Sweden)

    Jiho Moon

    2017-01-01

    Full Text Available A polymeric hybrid composite system made of UHPC and CFRP was proposed as a retrofit system to enhance flexural strength and ductility of RC slabs. While the effectiveness of the proposed system was confirmed previously through testing three full-scale one-way slabs having two continuous spans, the slabs retrofitted with the hybrid system failed in shear. This sudden shear failure would stem from the excessive enhancement of the flexural strength over the shear strength. In this study, shear connectors were installed between the hybrid system and a RC slab. Using simple beam, only positive moment section was examined. Two full-scale RC slabs were cast and tested to failure: the first as a control and the second using this new strengthening technique. The proposed strengthening system increased the ultimate load carrying capacity of the slab by 70%, the stiffness by 60%, and toughness by 128%. The efficiency of shear connectors on ductile behavior of the retrofitted slab was also confirmed. After the UHPC top is separated from the slab, the shear connector transfer shear load and the slab system were in force equilibrium by compression in UHPC and tension in CFRP.

  16. Density, refractive index, interfacial tension, and viscosity of ionic liquids [EMIM][EtSO4], [EMIM][NTf2], [EMIM][N(CN)2], and [OMA][NTf2] in dependence on temperature at atmospheric pressure.

    Science.gov (United States)

    Fröba, Andreas P; Kremer, Heiko; Leipertz, Alfred

    2008-10-02

    The density, refractive index, interfacial tension, and viscosity of ionic liquids (ILs) [EMIM][EtSO 4] (1-ethyl-3-methylimidazolium ethylsulfate), [EMIM][NTf 2] (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), [EMIM][N(CN) 2] (1-ethyl-3-methylimidazolium dicyanimide), and [OMA][NTf 2] (trioctylmethylammonium bis(trifluoromethylsulfonyl)imide) were studied in dependence on temperature at atmospheric pressure both by conventional techniques and by surface light scattering (SLS). A vibrating tube densimeter was used for the measurement of density at temperatures from (273.15 to 363.15) K and the results have an expanded uncertainty ( k = 2) of +/-0.02%. Using an Abbe refractometer, the refractive index was measured for temperatures between (283.15 and 313.15) K with an expanded uncertainty ( k = 2) of about +/-0.0005. The interfacial tension was obtained from the pendant drop technique at a temperature of 293.15 K with an expanded uncertainty ( k = 2) of +/-1%. For higher and lower temperatures, the interfacial tension was estimated by an adequate prediction scheme based on the datum at 293.15 K and the temperature dependence of density. For the ILs studied within this work, at a first order approximation, the quantity directly accessible by the SLS technique was the ratio of surface tension to dynamic viscosity. By combining the experimental results of the SLS technique with density and interfacial tension from conventional techniques, the dynamic viscosity could be obtained for temperatures between (273.15 and 333.15) K with an estimated expanded uncertainty ( k = 2) of less than +/-3%. The measured density, refractive index, and viscosity are represented by interpolating expressions with differences between the experimental and calculated values that are comparable with but always smaller than the expanded uncertainties ( k = 2). Besides a comparison with the literature, the influence of structural variations on the thermophysical properties of the

  17. EXPERIENCE WITH THE OPEN TENSION-FREE HERNIA REPAIR

    Directory of Open Access Journals (Sweden)

    Slavko Rakovec

    2002-03-01

    Full Text Available Background. All old techniques of herniorrhaphy involve approximation of tissues under tension, which accounts for their unreliability. Therefore the recovery time is long and the recurrence rate unacceptably high. The new methods using a mesh patch of polypropylene allow for a tensionfree repair, which is much more reliable. So they are associated with a shorter recovery time and carry a low probability of recurrence. The tension-free repair can be accomplished in an open manner, by placing the mesh through an open incision, or by the endoscopic technique, which involves placing the mesh from within by laparoscopic instruments. The open tension-free procedures can be performed with the use of stitches (according to Lichtenstein or without them (sutureless techniques. Stitching the mesh may cause problems due to maldistribution of tension between the mesh and the patient’s tissues, the occurrence of neuralgia or the development of inflammatory granuloma. Therefore sutureless procedures are increasingly performed. They usually require, besides the use of a mesh patch, also the use of a dart plug made of the same material.Methods. The open tension-free methods of hernia repair have been used at our Department since 1994. The first 77 operations were performed by Lichtenstein technique. The mean postoperative hospital stay was 3.4 days and the mean work restriction period was 3 weeks. In the middle of the year 1995, we shifted to suturless technique. By the end of the year 2000, we had performed 768 operations. The average postoperative hospital stay was 1.2 days and the average recovery time was 10 days.Results. In the first group of 77 hernia repairs performed by the Lichtenstein procedure serious complications were noted in six patients: bleeding in one, long-lasting neuralgia in two, and purulent granuloma, appearing long after discharge from the hospital, in three. There were no recurrences. In the second group of 768 hernia repairs

  18. [Peppermint oil in the acute treatment of tension-type headache].

    Science.gov (United States)

    Göbel, H; Heinze, A; Heinze-Kuhn, K; Göbel, A; Göbel, C

    2016-06-01

    Tension-type headache is the most frequent form of headache. The local topical treatment with peppermint oil (oleum menthae piperitae) has proven to be significantly more effective than placebo in controlled studies. Peppermint oil targets headache pathophysiology in multiple ways. The efficacy is comparable to that of acetylsalicylic acid or paracetamol. Solutions of 10 % peppermint oil in ethanol are licensed for the treatment of tension-type headache in adults and children above 6 years. It is included in treatment recommendations and guidelines by the respective professional societies and is regarded as a standard treatment for the acute therapy of tension-type headaches.

  19. Inference in hybrid Bayesian networks

    International Nuclear Information System (INIS)

    Langseth, Helge; Nielsen, Thomas D.; Rumi, Rafael; Salmeron, Antonio

    2009-01-01

    Since the 1980s, Bayesian networks (BNs) have become increasingly popular for building statistical models of complex systems. This is particularly true for boolean systems, where BNs often prove to be a more efficient modelling framework than traditional reliability techniques (like fault trees and reliability block diagrams). However, limitations in the BNs' calculation engine have prevented BNs from becoming equally popular for domains containing mixtures of both discrete and continuous variables (the so-called hybrid domains). In this paper we focus on these difficulties, and summarize some of the last decade's research on inference in hybrid Bayesian networks. The discussions are linked to an example model for estimating human reliability.

  20. The use of computational thermodynamics for the determination of surface tension and Gibbs-Thomson coefficient of multicomponent alloys

    Science.gov (United States)

    Ferreira, D. J. S.; Bezerra, B. N.; Collyer, M. N.; Garcia, A.; Ferreira, I. L.

    2018-04-01

    The simulation of casting processes demands accurate information on the thermophysical properties of the alloy; however, such information is scarce in the literature for multicomponent alloys. Generally, metallic alloys applied in industry have more than three solute components. In the present study, a general solution of Butler's formulation for surface tension is presented for multicomponent alloys and is applied in quaternary Al-Cu-Si-Fe alloys, thus permitting the Gibbs-Thomson coefficient to be determined. Such coefficient is a determining factor to the reliability of predictions furnished by microstructure growth models and by numerical computations of solidification thermal parameters, which will depend on the thermophysical properties assumed in the calculations. The Gibbs-Thomson coefficient for ternary and quaternary alloys is seldom reported in the literature. A numerical model based on Powell's hybrid algorithm and a finite difference Jacobian approximation has been coupled to a Thermo-Calc TCAPI interface to assess the excess Gibbs energy of the liquid phase, permitting liquidus temperature, latent heat, alloy density, surface tension and Gibbs-Thomson coefficient for Al-Cu-Si-Fe hypoeutectic alloys to be calculated, as an example of calculation capabilities for multicomponent alloys of the proposed method. The computed results are compared with thermophysical properties of binary Al-Cu and ternary Al-Cu-Si alloys found in the literature and presented as a function of the Cu solute composition.

  1. Insight and Evidence Motivating the Simplification of Dual-Analysis Hybrid Systems into Single-Analysis Hybrid Systems

    Science.gov (United States)

    Todling, Ricardo; Diniz, F. L. R.; Takacs, L. L.; Suarez, M. J.

    2018-01-01

    Many hybrid data assimilation systems currently used for NWP employ some form of dual-analysis system approach. Typically a hybrid variational analysis is responsible for creating initial conditions for high-resolution forecasts, and an ensemble analysis system is responsible for creating sample perturbations used to form the flow-dependent part of the background error covariance required in the hybrid analysis component. In many of these, the two analysis components employ different methodologies, e.g., variational and ensemble Kalman filter. In such cases, it is not uncommon to have observations treated rather differently between the two analyses components; recentering of the ensemble analysis around the hybrid analysis is used to compensated for such differences. Furthermore, in many cases, the hybrid variational high-resolution system implements some type of four-dimensional approach, whereas the underlying ensemble system relies on a three-dimensional approach, which again introduces discrepancies in the overall system. Connected to these is the expectation that one can reliably estimate observation impact on forecasts issued from hybrid analyses by using an ensemble approach based on the underlying ensemble strategy of dual-analysis systems. Just the realization that the ensemble analysis makes substantially different use of observations as compared to their hybrid counterpart should serve as enough evidence of the implausibility of such expectation. This presentation assembles numerous anecdotal evidence to illustrate the fact that hybrid dual-analysis systems must, at the very minimum, strive for consistent use of the observations in both analysis sub-components. Simpler than that, this work suggests that hybrid systems can reliably be constructed without the need to employ a dual-analysis approach. In practice, the idea of relying on a single analysis system is appealing from a cost-maintenance perspective. More generally, single-analysis systems avoid

  2. The Tension between Justice and Freedom in Paulo Freire's Epistemology.

    Science.gov (United States)

    Joldersma, Clarence W.

    2001-01-01

    Explores how the concept of freedom in Paulo Freire's constructivist epistemology-constituted as agentive, spontaneity-based action-is in tension with his ethical project of a pedagogy for justice, one based on responsibility and non-indifference. Resolution of this tension means reconceptualizing the grounding notion of the subject beyond a…

  3. Infinite tension limit of the pure spinor superstring

    Energy Technology Data Exchange (ETDEWEB)

    Berkovits, Nathan [ICTP South American Institute for Fundamental Research,Instituto de Física Teórica, UNESP - Univ. Estadual Paulista,Rua Dr. Bento T. Ferraz 271, 01140-070, São Paulo, SP (Brazil)

    2014-03-04

    Mason and Skinner recently constructed a chiral infinite tension limit of the Ramond-Neveu-Schwarz superstring which was shown to compute the Cachazo-He-Yuan formulae for tree-level d=10 Yang-Mills amplitudes and the NS-NS sector of tree-level d=10 supergravity amplitudes. In this letter, their chiral infinite tension limit is generalized to the pure spinor superstring which computes a d=10 superspace version of the Cachazo-He-Yuan formulae for tree-level d=10 super-Yang-Mills and supergravity amplitudes.

  4. Patient goals after tension free vaginal tape operation

    DEFF Research Database (Denmark)

    Glavind, Karin; Bjørk, Jonna; Kousgaard, Sabrina Just

    INTRODUCTION: This prospective study investigates sexual function in women after a tension-free vaginal tape (TVT) operation and compares short-term and long-term effects. METHODS: Sixty-three women had a TVT operation performed at Aalborg University Hospital, Department of Gynecology and Obstetr......INTRODUCTION: This prospective study investigates sexual function in women after a tension-free vaginal tape (TVT) operation and compares short-term and long-term effects. METHODS: Sixty-three women had a TVT operation performed at Aalborg University Hospital, Department of Gynecology...

  5. Application of DNA-DNA colony hybridization to the detection of catabolic genotypes in environmental samples

    International Nuclear Information System (INIS)

    Sayler, G.S.; Shields, M.S.; Tedford, E.T.; Breen, A.; Hooper, S.W.; Sirotkin, K.M.; Davis, J.W.

    1985-01-01

    The application of preexisting DNA hybridization techniques was investigated for potential in determining populations of specific gene sequences in environmental samples. Cross-hybridizations among two degradative plasmids, TOL and NAH, and two cloning vehicles, pLAFR1 and RSF1010, were determined. The detection limits for the TOL plasmid against a nonhomologous plasmid-bearing bacterial background was ascertained. The colony hybridization technique allowed detection of one colony containing TOL plasmid among 10(6) Escherichia coli colonies of nonhomologous DNA. Comparisons between population estimates derived from growth on selective substrates and from hybridizations were examined. Findings indicated that standard sole carbon source enumeration procedures for degradative populations lead to overestimations due to nonspecific growth of other bacteria on the microcontaminant carbon sources present in the media. Population estimates based on the selective growth of a microcosm population on two aromatic substrates (toluene and naphthalene) and estimates derived from DNA-DNA colony hybridizations, using the TOL or NAH plasmid as a probe, corresponded with estimates of substrate mineralization rates and past exposure to environmental contaminants. The applications of such techniques are hoped to eventually allow enumeration of any specific gene sequences in the environment, including both anabolic and catabolic genes. In addition, this procedure should prove useful in monitoring recombinant DNA clones released into environmental situations

  6. Estimation of reactive power sources dynamic limits for Volt / VAr control

    International Nuclear Information System (INIS)

    Orozco Alvarado, Juan Jose

    2013-01-01

    A generic model of capacity curves is obtained from the theoretical capacity curves of the distribution generators and reactive compensation elements. The obtained generic model is structured in a simplified method of points, taking eight strategic points of two detailed curves of a generator and through a series of interpolations, achieving the estimation of limits of capacity of delivery / consumption of the generator. The theory of electric generation elements and reactive power compensation is reviewed. The curves of capacity 'Reactive Power / Active Power' are achieved for different values of tension: from wind generators with complete converter and doubly fed, photovoltaic generators with inverter and synchronous generators. The 'Reactive Power / Line Tension' capacity curves are acquired from static var compensators (SVC). The generic limits of generators and SVC are estimated from the capacity curves [es

  7. Fields of Tension in a Boundary-Crossing World: Towards a Democratic Organization of the Self.

    Science.gov (United States)

    Hermans, Hubert J M; Konopka, Agnieszka; Oosterwegel, Annerieke; Zomer, Peter

    2017-12-01

    In their study of the relationship between self and society, scientists have proposed taking society as a metaphor for understanding the dynamics of the self, such as the analogy between the self and the functioning of a totalitarian state or the analogy between the self and the functioning of a bureaucratic organization. In addition to these models, the present article proposes a democratic society as a metaphor for understanding the workings of a dialogical self in a globalizing, boundary-crossing world. The article follows four steps. In the first step the self is depicted as extended to the social and societal environment and made up of fields of tension in which a multiplicity of self-positions are involved in processes of positioning and counter-positioning and in relationships of social power. In the second step, the fertility of the democratic metaphor is demonstrated by referring to theory and research from three identity perspectives: multicultural, multiracial, and transgender. In the fields of tension emerging between the multiplicity of self-positions, new, hybrid, and mixed identities have a chance to emerge as adaptive responses to the limitations of existing societal structures. In the third step, we place the democratic self in a broader societal context by linking three levels of inclusiveness, proposed by Self-Categorization Theory (personal, social, and human) to recent conceptions of a cosmopolitan democracy. In the fourth and final step, a model is presented which allows the formulation of a series of specific research questions for future studies of a democratically organized self.

  8. Modeling the surface tension of complex, reactive organic-inorganic mixtures

    Science.gov (United States)

    Schwier, A. N.; Viglione, G. A.; Li, Z.; McNeill, V. Faye

    2013-11-01

    Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as heterogeneous reactivity, ice nucleation, and cloud droplet formation. We present new experimental data for the surface tension of complex, reactive organic-inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2-6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two semi-empirical surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well described by a weighted Szyszkowski-Langmuir (S-L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling of aerosol systems because the Henning model (using data obtained from organic-inorganic systems) and Tuckermann approach provide similar modeling results and goodness-of-fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.

  9. Automatic control of arterial carbon dioxide tension in mechanically ventilated patients.

    Science.gov (United States)

    Fernando, Tyrone; Cade, John; Packer, John

    2002-12-01

    This paper presents a method of controlling the arterial carbon dioxide tension of patients receiving mechanical ventilation. Controlling of the CO2 tension is achieved by regulating the ventilator initiated breath frequency and also volume per breath.

  10. Tensions and Striving for Coherence in an Academic's Professional Identity Work

    Science.gov (United States)

    Arvaja, Maarit

    2018-01-01

    The emergence of 'new managerialism' in academic institutions and professions has given rise to tensions between one's professional self and work context. Such tensions often originate from a misalignment between institutional and personal values. This study builds on a dialogical approach to identity and discusses the role of inner tensions and…

  11. Notch effects in uniaxial tension specimens

    International Nuclear Information System (INIS)

    Delph, T.J.

    1979-03-01

    Results of a literature survey on the effect of notches on the time-dependent failure of uniaxial tension specimens at elevated temperatures are presented. Particular attention is paid to the failure of notched specimens containing weldments

  12. Mathematical foundations of hybrid data assimilation from a synchronization perspective

    Science.gov (United States)

    Penny, Stephen G.

    2017-12-01

    The state-of-the-art data assimilation methods used today in operational weather prediction centers around the world can be classified as generalized one-way coupled impulsive synchronization. This classification permits the investigation of hybrid data assimilation methods, which combine dynamic error estimates of the system state with long time-averaged (climatological) error estimates, from a synchronization perspective. Illustrative results show how dynamically informed formulations of the coupling matrix (via an Ensemble Kalman Filter, EnKF) can lead to synchronization when observing networks are sparse and how hybrid methods can lead to synchronization when those dynamic formulations are inadequate (due to small ensemble sizes). A large-scale application with a global ocean general circulation model is also presented. Results indicate that the hybrid methods also have useful applications in generalized synchronization, in particular, for correcting systematic model errors.

  13. Unilateral microform cleft lip repair: application of muscle tension line group theory.

    Science.gov (United States)

    Yin, Ningbei; Song, Tao; Wu, Jiajun; Chen, Bo; Ma, Hengyuan; Zhao, Zhenmin; Wang, Yongqian; Li, Haidong; Wu, Di

    2015-03-01

    In microform cleft lip repair, reconstructing the elaborate structures is difficult. We describe a new technique of unilateral microform cleft lip repair that is based on the muscle tension line group theory. According to the shape of Cupid bow, a different small incision is used without creating an obvious cutaneous scar. First, the nasolabial muscle around the nasal floor (the first auxiliary tension line group) is reconstructed, and then the orbicularis oris muscle around the philtrum (the second auxiliary tension line group) is reconstructed based on the muscle tension line group theory. From June 2006 to June 2012, the technique was used in 263 unilateral microform cleft lip repairs. For 18 months, 212 patients were followed up. The appearance of the nasal alar, nasal sill, philtrum, and Cupid bow peak improved. Most patients had a satisfactory appearance. Based on the muscle tension line group theory, using this technique offers the ability to adduct the nasal alar effectively to form a good nasal sill and philtrum.

  14. [Tension gastrothorax as a cause of death by obstructive shock - case report].

    Science.gov (United States)

    García-Regalado, Juan F; Navarro-Rojas, Mariana M

    2014-07-01

    Tension gastrothorax is caused by the herniation of the stomach into the thorax due to a congenital defect of the diaphragm; the Bochdaleck diaphragmatic hernia (HDB) is the most frequent type. Tension gastrothorax should be considered as a differential diagnosis in patients with obstructive shock and tension pneumothorax. A previously healthy 10 month-old male infant, who presented increased respiratory distress, increased volume of the left hemithorax, absence of breath sounds, ipsilateral hyper-resonance, 76% saturation, cold skin and capillary filling > 5 seconds, followed by a cardio-respiratory arrest. Due to clinical suspicion of pneumothorax, needle decompression was performed reversing cardiac arrest, but with persistent hemodynamic and respiratory instability; chest radiograph suggested diaphragmatic hernia. He underwent surgery confirming the presence of a diaphragmatic hernia of 5 cm. The evolution of this case shows the difficulty differentiating a tension gastrothorax from tension pneumothorax in patients admitted to the emergency room who are in serious condition; therefore, a high index of suspicion is needed for its identification.

  15. Development of a computer-controlled tensiometer for real-time measurements of tension in tubular organs.

    Science.gov (United States)

    Gregersen, H; Barlow, J; Thompson, D

    1999-04-01

    A computer-controlled tensiometer for studying wall tension in tubular organs has been developed. The system consisted of a probe with an inflatable balloon, an impedance planimeter, pressure transducer and amplifier, a pump with RS232 interface and a PC with dedicated software. Circumferential wall tension was computed in real time from pressure and cross-sectional area measurements (tension measurement mode). Wall tension can be maintained on a preset level or be changed as a step or ramp function by a feedback control of the infusion/withdrawal pump (tension control mode). A software regulator adjusted the volume rate (low volume rate when the computed tension was close to the preset value) to minimize overshoot and oscillation. Validation tests were performed and the technique was applied in the human oesophagus. Volume- and tension-controlled balloon distensions elicited secondary peristalsis of increasing intensity that was decreased significantly by the antimuscarinic agent Hyoscine butyl bromide. In tension control mode Hyoscine butyl bromide caused oesophageal relaxation, i.e. CSA to increase and pressure to decay. Furthermore, pronounced pressure relaxation and tension relaxation were observed during volume-controlled distension after administration of Hyoscine butyl bromide.

  16. Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion

    DEFF Research Database (Denmark)

    Noergaard, Michael Hove; Bach-Holm, Daniella; Scherfig, Erik

    2008-01-01

    To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.......To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs....

  17. Central and peripheral mechanisms in chronic tension-type headache

    OpenAIRE

    Lipchik, Gay L.; Holroyd, Kenneth A.; France, Christopher R.; Kvaal, Steven A.; Segal, David; Cordingley, Gary E.; Rokicki, Lori A.; McCool, Heidi R.

    1996-01-01

    The second exteroceptive suppression of masseter muscle activity (ES2) and tenderness in pericranial muscles were evaluated in 112 young adults who met IHS criteria in the following diagnostic classifications: 31 chronic tension headache, 31 episodic tension headache, 33 migraine without aura and 17 migraine with aura. An additional 31 subjects served as controls. Pericranial muscle tenderness better distinguished diagnostic subgroups and better distinguished recurrent headache sufferers from...

  18. Study on the makinq of Cockroft Walton high tension

    International Nuclear Information System (INIS)

    Hutapea, Sumihar.

    1976-01-01

    A prototype of a generator is being developed at the GAMA Research Center. Experience in working with some components, high voltage capacitor, column, and potential divider is discussed. High voltage diode, the type which is usually used in television, is used. The tension of the generator is measured by using the high ohmic resistence of 4000 megaohm. The maximum tension can be reached no more than 150000 volts. (author)

  19. Thermal Characteristics of Plastic Film Tension in Roll-to-Roll Gravure Printed Electronics

    Directory of Open Access Journals (Sweden)

    Kui He

    2018-02-01

    Full Text Available In the printing section of a roll-to-roll gravure printed electronics machine, the plastic film tension is directly associated with the product quality. The temperature distribution of the plastic film in the printing section is non-uniform, because of the higher drying temperature and the lower room temperature. Furthermore, the drying temperature and the room temperature are not constants in industrial production. As the plastic film is sensitive to temperature, the temperature of the plastic film will affects the web tension in the printing section. In this paper, the thermal characteristics of the plastic film tension in roll-to-roll gravure printed electronics are studied in order to help to improve the product quality. First, the tension model including the factor of temperature is derived based on the law of mass conservation. Then, some simulations and experiments are carried out in order to in-depth research the effects of the drying temperature and room temperature based on the relations between system inputs and outputs. The results show that the drying temperature and room temperature have significant influences on the web tension. The research on the thermal characteristics of plastic film tension would benefit the tension control accuracy for further study.

  20. Force generation and temperature-jump and length-jump tension transients in muscle fibers.

    Science.gov (United States)

    Davis, J S; Rodgers, M E

    1995-01-01

    Muscle tension rises with increasing temperature. The kinetics that govern the tension rise of maximally Ca(2+)-activated, skinned rabbit psoas fibers over a temperature range of 0-30 degrees C was characterized in laser temperature-jump experiments. The kinetic response is simple and can be readily interpreted in terms of a basic three-step mechanism of contraction, which includes a temperature-sensitive rapid preequilibrium(a) linked to a temperature-insensitive rate-limiting step and followed by a temperature-sensitive tension-generating step. These data and mechanism are compared and contrasted with the more complex length-jump Huxley-Simmons phases in which all states that generate tension or bear tension are perturbed. The rate of the Huxley-Simmons phase 4 is temperature sensitive at low temperatures but plateaus at high temperatures, indicating a change in rate-limiting step from a temperature-sensitive (phase 4a) to a temperature-insensitive reaction (phase 4b); the latter appears to correlate with the slow, temperature-insensitive temperature-jump relaxation. Phase 3 is absent in the temperature-jump, which excludes it from tension generation. We confirm that de novo tension generation occurs as an order-disorder transition during phase 2slow and the equivalent, temperature-sensitive temperature-jump relaxation. PMID:7612845

  1. Influence of specimen type and reinforcement on measured tension-tension fatigue life of unidirectional GFRP laminates

    DEFF Research Database (Denmark)

    Korkiakoski, Samuli; Brøndsted, Povl; Sarlin, Essi

    2016-01-01

    It is well known that standardised tension-tension fatigue test specimens of unidirectional (UD) glass-fibre-reinforced plastics (GFRP) laminates tend to fail at end tabs. The true fatigue life is then underestimated. The first objective of this study was to find for UD GFRP laminates a test...... specimen that fails in the gauge section. The second objective was to compare fatigue performance of two laminates, one having a newly developed UD powder-bound fabric as a reinforcement and the other having a quasi-UD stitched non-crimp fabric as a reinforcement. In the first phase, a rectangular specimen...... in accordance with the ISO 527-5 standard and two slightly different dog-bone shaped specimens were evaluated by means of finite element modelling. Subsequent comparative fatigue tests were performed for the laminates with the three specimen types. The results showed that the test specimen type has...

  2. Post-tensioning and splicing of precast/prestressed bridge beams to extend spans

    Science.gov (United States)

    Collett, Brandon S.; Saliba, Joseph E.

    2002-06-01

    This paper explores the status and techniques of post-tensioning and splicing precast concrete I-beams in bridge applications. It will look at the current practices that have been used in the United States and comment on the advantages of these techniques. Representative projects are presented to demonstrate the application and success of specific methods used. To demonstrate the benefits of using post-tensioning and splicing to extend spans, multiple analysis of simple span post-tensioned I-beams were performed varying such characteristics as beam spacing, beam sections, beam depth and concrete strength. Tables were then developed to compare the maximum span length of a prestressed I-beam versus a one segment or a spliced three segment post-tensioned I-beam. The lateral stability of the beam during fabrication, transportation and erection is also examined and discussed. These tables are intended to aid designers and owners in preliminary project studies to determine if post-tensioning can be beneficial to their situation. AASHTO Standard Specifications(2) will be used as basic guidelines and specifications. In many cases, post-tensioning was found to extend the maximum span length of a typical 72-inch precast I-beam more than 40 feet over conventional prestress.

  3. Detection of low tension cosmic superstrings

    Science.gov (United States)

    Chernoff, David F.; Tye, S.-H. Henry

    2018-05-01

    Cosmic superstrings of string theory differ from conventional cosmic strings of field theory. We review how the physical and cosmological properties of the macroscopic string loops influence experimental searches for these relics from the epoch of inflation. The universe's average density of cosmic superstrings can easily exceed that of conventional cosmic strings having the same tension by two or more orders of magnitude. The cosmological behavior of the remnant superstring loops is qualitatively distinct because the string tension is exponentially smaller than the string scale in flux compactifications in string theory. Low tension superstring loops live longer, experience less recoil (rocket effect from the emission of gravitational radiation) and tend to cluster like dark matter in galaxies. Clustering enhances the string loop density with respect to the cosmological average in collapsed structures in the universe. The enhancement at the Sun's position is ~ 105. We develop a model encapsulating the leading order string theory effects, the current understanding of the string network loop production and the influence of cosmological structure formation suitable for forecasting the detection of superstring loops via optical microlensing, gravitational wave bursts and fast radio bursts. We evaluate the detection rate of bursts from cusps and kinks by LIGO- and LISA-like experiments. Clustering dominates rates for G μ 10‑14.2 (LIGO cusp), G μ>10‑15 (LISA cusp) and G μ>10‑ 14.1 (LISA kink).

  4. Minimally invasive tension band wiring technique for olecranon fractures.

    Science.gov (United States)

    Takada, Naoya; Kato, Kenji; Fukuta, Makoto; Wada, Ikuo; Otsuka, Takanobu

    2013-12-01

    Some types of implants, such as plates, screws, wires, and nails, have been used for open reduction and internal fixation of olecranon fractures. A ≥ 10 cm longitudinal incision is used for open reduction and internal fixation of olecranon fractures. According to previous studies, tension band wiring is a popular method that gives good results. However, back out of the wires after the surgery is one of the main postoperative complications. Moreover, if the Kirschner wires are inserted through the anterior ulnar cortex, they may impinge on the radial neck, supinator muscle, or biceps tendon. Herein, we describe the minimally invasive tension band wiring technique using Ring-Pin. This technique can be performed through a 2 cm incision. Small skin incisions are advantageous from an esthetic viewpoint. Ring-Pin was fixed by using a dedicated cable wire that does not back out unless the cable wire breaks or slips out of the dedicated metallic clamp. As the pins are placed in intramedullary canal, this technique does not lead to postoperative complications that may occur after transcortical fixation by conventional tension band wiring. Minimally invasive tension band wiring is one of the useful options for the treatment of olecranon fractures with some advantages.

  5. Tension cost correlates with mechanical and biochemical parameters in different myocardial contractility conditions

    Directory of Open Access Journals (Sweden)

    Cleci M. Moreira

    2012-01-01

    Full Text Available OBJECTIVES: Tension cost, the ratio of myosin ATPase activity to tension, reflects the economy of tension development in the myocardium. To evaluate the mechanical advantage represented by the tension cost, we studied papillary muscle contractility and the activity of myosin ATPase in the left ventricles in normal and pathophysiological conditions. METHODS: Experimental protocols were performed using rat left ventricles from: (1 streptozotocin-induced diabetic and control Wistar rats; (2 N-nitro-L-arginine methyl ester (L-NAME hypertensive and untreated Wistar rats; (3 deoxycorticosterone acetate (DOCA salt-treated, nephrectomized and salt- and DOCA-treated rats; (4 spontaneous hypertensive rats (SHR and Wistar Kyoto (WKY rats; (5 rats with myocardial infarction and shamoperated rats. The isometric force, tetanic tension, and the activity of myosin ATPase were measured. RESULTS: The results obtained from infarcted, diabetic, and deoxycorticosterone acetate-salt-treated rats showed reductions in twitch and tetanic tension compared to the control and sham-operated groups. Twitch and tetanic tension increased in the N-nitro-L-arginine methyl ester-treated rats compared with the Wistar rats. Myosin ATPase activity was depressed in the infarcted, diabetic, and deoxycorticosterone acetate salt-treated rats compared with control and sham-operated rats and was increased in N-nitro-L-arginine methyl ester-treated rats. These parameters did not differ between SHR and WKY rats. In the studied conditions (e.g., post-myocardial infarction, deoxycorticosterone acetate salt-induced hypertension, chronic N-nitro-L-arginine methyl ester treatment, and streptozotocin-induced diabetes, a positive correlation between force or plateau tetanic tension and myosin ATPase activity was observed. CONCLUSION: Our results suggest that the myocardium adapts to force generation by increasing or reducing the tension cost to maintain myocardial contractility with a better

  6. Hydraulic nuts (HydraNuts) for reactor vessel tensioning

    International Nuclear Information System (INIS)

    Greenwell, Steve

    2008-01-01

    The paper will present how the introduction of hydraulic nuts - HydraNuts, has reduced critical path times, dose exposure for workers and improved working safety conditions around the reactor vessel during tensioning or de-tensioning operations. It will focus upon detailing the advantages realized by utilities that have introduced the technology and providing examples of the improvements made to the process as well as discussing the engineering design change packages required to make the conversion to the new system. HydraNuts replace the traditional mechanical nut/stud tensioning equipment, combining the two functions into a single system, designed for easy installation and operation by one individual. The primary components of the HydraNut can be assembled without the need for external crane or hoist support and are designed so that each sub assembly can be fitted separately. Once all HydraNuts are fitted to the Rx vessel studs and are sitting on the main Rx vessel head flange, then a system of flexible hydraulic hoses is connected to them, forming a closed loop hydraulic harness, which will allow for simultaneous pressurization of all HydraNuts. Hydraulic pressure is obtained by the use of a hydraulic pumping unit and the resultant load generated in each HydraNut is transferred to the stud and main flange closure is obtained. While maintaining hydraulic pressure, a locking ring is rotated into place on the HydraNut assembly that will support the tensioned load mechanically when the hydraulic pressure is released from the hose harness assembly. The hose harness is removed and the HydraNut is now functioning as a mechanical nut retaining the tensioned load. The HydraNut system for Rx vessel applications was first introduced into a plant in the U.S. in October 2006 and based upon the benefits realized subsequent projects are under way within the Asian and U.S. operating fleet. (author)

  7. Model-on-Demand Predictive Control for Nonlinear Hybrid Systems With Application to Adaptive Behavioral Interventions

    Science.gov (United States)

    Nandola, Naresh N.; Rivera, Daniel E.

    2011-01-01

    This paper presents a data-centric modeling and predictive control approach for nonlinear hybrid systems. System identification of hybrid systems represents a challenging problem because model parameters depend on the mode or operating point of the system. The proposed algorithm applies Model-on-Demand (MoD) estimation to generate a local linear approximation of the nonlinear hybrid system at each time step, using a small subset of data selected by an adaptive bandwidth selector. The appeal of the MoD approach lies in the fact that model parameters are estimated based on a current operating point; hence estimation of locations or modes governed by autonomous discrete events is achieved automatically. The local MoD model is then converted into a mixed logical dynamical (MLD) system representation which can be used directly in a model predictive control (MPC) law for hybrid systems using multiple-degree-of-freedom tuning. The effectiveness of the proposed MoD predictive control algorithm for nonlinear hybrid systems is demonstrated on a hypothetical adaptive behavioral intervention problem inspired by Fast Track, a real-life preventive intervention for improving parental function and reducing conduct disorder in at-risk children. Simulation results demonstrate that the proposed algorithm can be useful for adaptive intervention problems exhibiting both nonlinear and hybrid character. PMID:21874087

  8. Changing market values? Tensions of contradicting public management discourses

    DEFF Research Database (Denmark)

    Plotnikof, Mie

    2016-01-01

    that the discursive tensions between such value-laden practices indicate a changing marketization associated with collaboration and trust, yet also competition. Research limitations/implications To research it becomes critical to advance theoretical and empirical knowledge on the constitutive effects of such complex......The purpose of this paper is to address studies of New Public Governance (NPG) as a post-New Public Management (NPM) tendency. Although NPG is considered a contrast to NPM and its market incentives, it argues that the practices emerging in tensions of NPM and NPG discourses indicate not a clear......-cut shift away from NPM, but rather changes that combine competition with collaboration and trust. Design/methodology/approach It offers a discourse approach to advance the theorizing and empirical unfolding of the tensions of contradicting, yet co-existing discourses of NPM and NPG and their effects...

  9. Surface tension in microsystems engineering below the capillary length

    CERN Document Server

    Lambert, Pierre

    2014-01-01

    This book describes how surface tension effects can be used by engineers to provide mechanical functions in miniaturized products (<1 mm). Even if precursors of this field such as Jurin or Laplace already date back to the 18th century, describing surface tension effects from a mechanical perspective is very recent. The originality of this book is to consider the effects of capillary bridges on solids, including forces and torques exerted both statically and dynamically by the liquid along the 6 degrees-of-freedom. It provides a comprehensive approach to various applications, such as capillary adhesion (axial force), centering force in packaging and micro-assembly (lateral force) and recent developments such as a capillary motor (torque). It devises how surface tension can be used to provide mechanical functions such as actuation (bubble-actuated compliant table), sealing and tightness, energy harvesting, nanodispending.

  10. Experiment and model for the surface tension of amine–ionic liquids aqueous solutions

    International Nuclear Information System (INIS)

    Zhang, Pan; Du, LeiXia; Fu, Dong

    2014-01-01

    Highlights: • The surface tensions of MEA/DEA–ionic liquids aqueous solutions were measured. • The experiments were modeled satisfactorily by using a thermodynamic equation. • The temperature dependence of the surface tension was illustrated. • The effects of the mass fractions of MEA/DEA and ionic liquids were demonstrated. - Abstract: The surface tension (γ) of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF 4 ])–monoethanolamine (MEA), 1-butyl-3-methylimidazolium bromide ([Bmim][Br])–MEA, [Bmim][BF 4 ]–diethanolamine (DEA) and [Bmim][Br]–DEA aqueous solutions was measured by using the BZY-1 surface tension meter. The temperature ranged from (293.2 to 323.2) K. The mass fraction of amines and ionic liquids (ILS) respectively ranged from 0.15 to 0.30 and 0.05 to 0.10. A thermodynamic equation was proposed to model the surface tension of amines–ILS aqueous solutions and the calculated results agreed well with the experiments. The effects of temperature, mass fraction of amines and ILS on the surface tension were demonstrated on the basis of experiments and calculations

  11. In situ hybridization at the electron microscope level: hybrid detection by autoradiography and colloidal gold.

    Science.gov (United States)

    Hutchison, N J; Langer-Safer, P R; Ward, D C; Hamkalo, B A

    1982-11-01

    In situ hybridization has become a standard method for localizing DNA or RNA sequences in cytological preparations. We developed two methods to extend this technique to the transmission electron microscope level using mouse satellite DNA hybridization to whole mount metaphase chromosomes as the test system. The first method devised is a direct extension of standard light microscope level using mouse satellite DNA hybridization to whole mount metaphase chromosomes as the test system. The first method devised is a direct extension of standard light microscope in situ hybridization. Radioactively labeled complementary RNA (cRNA) is hybridized to metaphase chromosomes deposited on electron microscope grids and fixed in 70 percent ethanol vapor; hybridixation site are detected by autoradiography. Specific and intense labeling of chromosomal centromeric regions is observed even after relatively short exposure times. Inerphase nuclei present in some of the metaphase chromosome preparations also show defined paatterms of satellite DNA labeling which suggests that satellite-containing regions are associate with each other during interphase. The sensitivity of this method is estimated to at least as good as that at the light microscope level while the resolution is improved at least threefold. The second method, which circumvents the use of autoradiogrphic detection, uses biotin-labeled polynucleotide probes. After hybridization of these probes, either DNA or RNA, to fixed chromosomes on grids, hybrids are detected via reaction is improved at least threefold. The second method, which circumvents the use of autoradiographic detection, uses biotin-labeled polynucleotide probes. After hybridization of these probes, either DNA or RNA, to fixed chromosomes on grids, hybrids are detected via reaction with an antibody against biotin and secondary antibody adsorbed to the surface of over centromeric heterochromatin and along the associated peripheral fibers. Labeling is on average

  12. Characterization of tillage effects on soil permeability using different measures of macroporosity derived from tension infiltrometry

    Science.gov (United States)

    Bodner, G.; Schwen, A.; Scholl, P.; Kammerer, G.; Buchan, G.; Kaul, H.-P.; Loiskandl, W.

    2010-05-01

    Soil macroporosity is a highly dynamic property influenced by environmental factors, such as raindrop impact, wetting-drying and freezing-thawing cycles, soil biota and plant roots, as well as agricultural management measures. Macroporosity represents an important indicator of soil physical quality, particularly in relation to the site specific water transmission properties, and can be used as a sensitive measure to assess soil structural degradation. Its quantification is also required for the parameterization of dual porosity models that are frequently used in environmental impact studies on erosion and solute (pesticide, nitrate) leaching. The importance of soil macroporosity for the water transport properties of the soil and its complexity due to high spatio-temporal heterogeneity make its quantitative assessment still a challenging task. Tension infiltrometers have been shown to be adequate measurement devices to obtain data in the near-saturated range of water flow where structural (macro)pores are dominating the transport process. Different methods have been used to derive water transmission characteristics from tension infiltrometer measurements. Moret and Arrúe (2007) differentiated between using a minimum equivalent capillary pore radius and a flow weighted mean pore radius to obtain representative macropore flow properties from tension infiltrometer data. Beside direct approaches based on Wooding's equation, also inverse methods have been applied to obtain soil hydraulic properties (Šimůnek et al. 1998). Using a dual porosity model in the inverse procedure allows estimating parameters in the dynamic near-saturated range by numerical optimization to the infiltration measurements, while fixing parameters in the more stable textural range of small pores using e.g. pressure plate data or even pedotransfer functions. The present work presents a comparison of quantitative measures of soil macroporosity derived from tension infiltrometer data by different

  13. Parenteral treatment of episodic tension-type headache: a systematic review.

    Science.gov (United States)

    Weinman, Danielle; Nicastro, Olivia; Akala, Olabiyi; Friedman, Benjamin W

    2014-02-01

    Tension-type headache is highly prevalent in the general population and is a consistent if not frequent cause of visits to acute care settings. Analgesics such as nonsteroidal anti-inflammatory drugs, acetaminophen, and salicylates are considered first-line therapy for treatment of tension-type headache. For patients who present to an acute care setting with persistent tension-type headache despite analgesic therapy, it is not clear which parenteral agent should be administered. We performed a systematic review of the medical literature to determine whether parenteral therapies other than salicylates or nonsteroidals are efficacious for acute tension-type headache. We performed a systematic review of Medline, EMBASE, CINAHL, Google scholar, and the Cochrane Central Registry of Controlled Trials from inception through August, 2012 using the search terms "tension-type headache" and "parenteral or subcutaneous or intramuscular or intravenous." Our goal was to identify randomized trials in which one parenteral treatment was compared to another active comparator or to placebo for the acute relief of tension-type headache. Parenteral was defined as intravenous, intramuscular, or subcutaneous administration. We only included studies that distinguished tension-type headache from other primary headache disorders, such as migraine. The primary outcome for this review was measures of efficacy one hour after medication administration. Data abstraction was performed by two authors. Disagreements were resolved by a third author. We assessed the internal validity of trials using the Cochrane Collaboration risk of bias tool. Because of the small number of trials identified, and the substantial heterogeneity among study design and medications, we decided that combining data and reporting summary statistics would serve no useful function. The results of individual studies are presented using Number Needed to Treat (NNT) with 95%CI when dichotomous outcomes were available and

  14. Cadherin adhesion, tissue tension, and noncanonical Wnt signaling regulate fibronectin matrix organization.

    Science.gov (United States)

    Dzamba, Bette J; Jakab, Karoly R; Marsden, Mungo; Schwartz, Martin A; DeSimone, Douglas W

    2009-03-01

    In this study we demonstrate that planar cell polarity signaling regulates morphogenesis in Xenopus embryos in part through the assembly of the fibronectin (FN) matrix. We outline a regulatory pathway that includes cadherin adhesion and signaling through Rac and Pak, culminating in actin reorganization, myosin contractility, and tissue tension, which, in turn, directs the correct spatiotemporal localization of FN into a fibrillar matrix. Increased mechanical tension promotes FN fibril assembly in the blastocoel roof (BCR), while reduced BCR tension inhibits matrix assembly. These data support a model for matrix assembly in tissues where cell-cell adhesions play an analogous role to the focal adhesions of cultured cells by transferring to integrins the tension required to direct FN fibril formation at cell surfaces.

  15. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    KAUST Repository

    Elsheikh, Ahmed H.; Wheeler, Mary Fanett; Hoteit, Ibrahim

    2014-01-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using

  16. A hybrid method for accurate star tracking using star sensor and gyros.

    Science.gov (United States)

    Lu, Jiazhen; Yang, Lie; Zhang, Hao

    2017-10-01

    Star tracking is the primary operating mode of star sensors. To improve tracking accuracy and efficiency, a hybrid method using a star sensor and gyroscopes is proposed in this study. In this method, the dynamic conditions of an aircraft are determined first by the estimated angular acceleration. Under low dynamic conditions, the star sensor is used to measure the star vector and the vector difference method is adopted to estimate the current angular velocity. Under high dynamic conditions, the angular velocity is obtained by the calibrated gyros. The star position is predicted based on the estimated angular velocity and calibrated gyros using the star vector measurements. The results of the semi-physical experiment show that this hybrid method is accurate and feasible. In contrast with the star vector difference and gyro-assisted methods, the star position prediction result of the hybrid method is verified to be more accurate in two different cases under the given random noise of the star centroid.

  17. Surface tension effects on vertical upward annular flows in a small diameter pipe

    Energy Technology Data Exchange (ETDEWEB)

    Sadatomi, Michio, E-mail: sadatomi@mech.kumamoto-u.ac.jp [Dept. of Advanced Mechanical Systems, Kumamoto Univ., 39-1, Kurokami 2-chome, Chuou-ku, Kumamoto 860-8555 (Japan); Kawahara, Akimaro [Dept. of Advanced Mechanical Systems, Kumamoto Univ., 39-1, Kurokami 2-chome, Chuou-ku, Kumamoto 860-8555 (Japan); Suzuki, Aruta [Plant Design & Engineering Dept., Environment, Energy & Plant Headquarters, Hitachi Zosen Corporation, 7-89, Nankokita 1-chome, Suminoe-ku, Osaka, 559-8559 (Japan)

    2016-12-15

    Highlights: • Surface tension effects were clarified on annular flow in a small diameter pipe. • The mean liquid film thickness became thinner with decreasing of surface tension. • The liquid droplet fraction and the interfacial shear stress became higher with it. • New prediction methods for the above parameters were developed and validated. - Abstract: Experiments were conducted to study the surface tension effects on vertical upward annular flows in a 5 mm I.D. pipe using water and low surface tension water with a little surfactant as the test liquid and air as the test gas. Firstly, the experimental results on the mean liquid film thickness, the liquid droplet fraction and the interfacial shear stress in annular flows together with some flow pictures are presented to clarify the surface tension effects. From these, the followings are clarified: In the low surface tension case, the liquid film surface becomes rough, the liquid film thickness thin, the liquid droplet fraction high, and the interfacial shear stress high. Secondary, correlations in literatures for the respective parameters are tested against the present data. The test results show that no correlation for the respective parameters could predict well the present data. Thus, correlations are revised by accounting for the surface tension effects. The results of the experiments, the correlations tests and their revisions mentioned above are presented in the present paper.

  18. Graft fixation with predetermined tension using a new device, the double spike plate.

    Science.gov (United States)

    Shino, Konsei; Mae, Tatsuo; Maeda, Akira; Miyama, Takahide; Shinjo, Hirotaka; Kawakami, Hideo

    2002-10-01

    To biomechanically evaluate a new fixation device, DSP (Double Spike Plate; Meira Corp, Nagoya, Aichi, Japan), for pullout graft fixation. Biomechanical study. A porcine tibia in which 8-mm diameter drill holes had been made from the medial tibial metaphysis to the anterior cruciate ligament attachment was rigidly fixed to a tension analyzer. A quadrupled graft consisting of 2 double-looped bovine tendons was prepared with No. 3 polyester sutures placed distally. The graft was passed through the drill hole, and its proximal loop ends were rigidly fixed to a load cell for monitoring graft tension. The graft's distal ends were connected to the DSP by tying the sutures to the top hole in the DSP. The graft tension was predetermined at 49 N (n = 5) or 98 N (n = 5). This tension was maintained for 5 minutes with a suture passed through the bottom hole of the DSP. The plate was fixed to the tibia by hammering its spikes into the bone under the index tension. Finally, the fixation was completed by inserting a screw. Although the graft tension immediately increased to 69 +/- 11 N or 133 +/- 14 N during hammering, it gradually reduced to 49 +/- 10 N or 100 +/- 7 N 5 minutes later. This study shows that graft fixation under a predetermined tension can be achieved with the DSP.

  19. Hybrid rocket engine, theoretical model and experiment

    Science.gov (United States)

    Chelaru, Teodor-Viorel; Mingireanu, Florin

    2011-06-01

    The purpose of this paper is to build a theoretical model for the hybrid rocket engine/motor and to validate it using experimental results. The work approaches the main problems of the hybrid motor: the scalability, the stability/controllability of the operating parameters and the increasing of the solid fuel regression rate. At first, we focus on theoretical models for hybrid rocket motor and compare the results with already available experimental data from various research groups. A primary computation model is presented together with results from a numerical algorithm based on a computational model. We present theoretical predictions for several commercial hybrid rocket motors, having different scales and compare them with experimental measurements of those hybrid rocket motors. Next the paper focuses on tribrid rocket motor concept, which by supplementary liquid fuel injection can improve the thrust controllability. A complementary computation model is also presented to estimate regression rate increase of solid fuel doped with oxidizer. Finally, the stability of the hybrid rocket motor is investigated using Liapunov theory. Stability coefficients obtained are dependent on burning parameters while the stability and command matrixes are identified. The paper presents thoroughly the input data of the model, which ensures the reproducibility of the numerical results by independent researchers.

  20. Horizontally-connected ZnO-graphene hybrid films for multifunctional devices

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Yi Rang [Thin Film Materials Research Center, Korea Research Institute of Chemical Technology, Yuseong Post Office Box 107, Daejeon 305-600 (Korea, Republic of); School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center (SPRC), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Song, Wooseok; Lee, Young Bum; Kim, Seong Ku; Han, Jin Kyu; Myung, Sung; Lee, Sun Sook; An, Ki-Seok [Thin Film Materials Research Center, Korea Research Institute of Chemical Technology, Yuseong Post Office Box 107, Daejeon 305-600 (Korea, Republic of); Choi, Chel-Jong [School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center (SPRC), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lim, Jongsun, E-mail: jslim@krict.re.kr [Thin Film Materials Research Center, Korea Research Institute of Chemical Technology, Yuseong Post Office Box 107, Daejeon 305-600 (Korea, Republic of)

    2016-08-30

    Highlights: • We designed horizontally-connected ZnO and graphene hybrid nanofilms with improved flexibility for multifunctional nanodevices including high performance TFTs. • The photocurrent on-off ratio, response time, and recovery time of the hybrid photodetectors were estimated to be 10{sup 2}, 34 s, and 27 s, respectively. The photocurrent from the hybrid photodetector decreased only by two-fold, whereas a significant decrease in photocurrent by two orders of magnitude was observed from the ZnO thin film based photodetectors after 10{sup 5} cycles of 5-mm radius bending. • The hybrid thin film transistors exhibited unipolar n-channel transistor behavior with electron mobility of 68.7 cm{sup 2}/V s and on-off ratio of 10{sup 7}. - Abstract: Here we designed horizontally-connected ZnO thin films and graphene in order to combine advantages of ZnO thin films, which are high on/off ratio and photo responsivity, and the superior mobility and sensitivity of graphene for applications in thin film transistors (TFTs) and flexible photodetectors. To synthesize the ZnO/graphene hybrid films, a 70-nm-thick ZnO thin film with a uniformly flat surface deposited by the atomic layer deposition process was horizontally connected with highly crystalline monolayer graphene grown by thermal chemical vapor deposition. The photocurrent on-off ratio, response time, and recovery time of the hybrid photodetectors were estimated to be 10{sup 2}, 34 s, and 27 s, respectively. The photocurrent from the hybrid photodetector decreased only by two-fold, whereas a significant decrease in photocurrent by two orders of magnitude was observed from the ZnO thin film based photodetectors after 10{sup 5} cycles of 5-mm radius bending. The hybrid TFT exhibited unipolar n-channel transistor behavior with electron mobility of 68.7 cm{sup 2}/V s and on-off ratio of 10{sup 7}.

  1. Transient interfacial tension and dilatational rheology of diffuse polymer-polymer interfaces

    NARCIS (Netherlands)

    Peters, G.W.M.; Zdravkov, A.N.; Meijer, H.E.H.

    2005-01-01

    We demonstrate the influence of molecular weight and molecular weightasymmetry across an interface on the transient behavior of the interfacial tension. The interfacial tension was measured as a function of time for a range of polymer combinations with a broadrange of interfacial properties using a

  2. Lung abscess presenting as tension pyopneumothorax in a gastrointestinal cancer patient.

    Science.gov (United States)

    Okita, Riki; Miyata, Yoshihiro; Hamai, Yoichi; Hihara, Jun; Okada, Morihito

    2014-01-01

    We report a surgical case of tension pyopneumothorax in a patient who was receiving chemotherapy for esophageal cancer. A 68-year-old man who had undergone total gastrectomy with splenectomy for gastric cancer and was receiving chemotherapy for esophageal cancer was presented to our hospital with dyspnea. Left tension pyopneumothorax was diagnosed, and he received left lower lobectomy after pleural drainage. His postoperative course was uneventful, and he is alive without any cancer recurrences 5 years after the lobectomy. Once tension pyopneumothorax has developed from lung abscess, emergent lobectomy may be a useful option to prevent lethal aspiration pneumonia.

  3. Social tension as precursor of large damaging earthquake: legend or reality?

    Science.gov (United States)

    Molchanov, O.

    2008-11-01

    Using case study of earthquake (EQ) activity and war conflicts in Caucasus during 1975 2002 time interval and correlation analysis of global distribution of damaging EQs and war-related social tension during 1901 2005 period we conclude: There is a statistically reliable increase of social tension several years (or several months in case study) before damaging EQs, There is evident decrease of social tension several years after damaging EQs, probably due to society consolidation, Preseismic effect is absent for the large EQs in unpopulated areas, There is some factual background for legendary belief in Almighty retribution for social abnormal behavior.

  4. Tension-type headache

    DEFF Research Database (Denmark)

    Bendtsen, Lars; Jensen, Rigmor; Bendtsen, Lars

    2009-01-01

    The substantial societal and individual burdens associated with tension-type headache (TTH) constitute a previously overlooked major public health issue. TTH is prevalent, affecting up to 78% of the general population, and 3% suffer from chronic TTH. Pericranial myofascial nociception probably...... is important for the pathophysiology of episodic TTH, whereas sensitization of central nociceptive pathways seems responsible for the conversion of episodic to chronic TTH. Headache-related disability usually can be reduced by identification of trigger factors combined with nonpharmacologic and pharmacologic...... treatments, but effective treatment modalities are lacking. Benefits can be gained by development of specific and effective treatment strategies....

  5. AUTOGENIC THERAPY IN TENSION HEADACHE

    Science.gov (United States)

    Amruthraj, Brunda; Mishra, H.; Kumaraiah, V.

    1987-01-01

    SUMMARY Ten subjects diagnosed as Psychalgia were taken for study. A multiple baseline design was adapted and clients were subjected to 30 sessions of autogenic training. They were assessed using physiological (EMG and thermal change) and behavioural measures (Visual analogue scale and behavioural symptom checklist). Findings revealed autogenic therapy to be effective in reducing tension headache. PMID:21927245

  6. AUTOGENIC THERAPY IN TENSION HEADACHE

    OpenAIRE

    Amruthraj, Brunda; Mishra, H.; Kumaraiah, V.

    1987-01-01

    SUMMARY Ten subjects diagnosed as Psychalgia were taken for study. A multiple baseline design was adapted and clients were subjected to 30 sessions of autogenic training. They were assessed using physiological (EMG and thermal change) and behavioural measures (Visual analogue scale and behavioural symptom checklist). Findings revealed autogenic therapy to be effective in reducing tension headache.

  7. Static and dynamic testing of a damaged post tensioned concrete beam

    Directory of Open Access Journals (Sweden)

    Limongelli M.P.

    2015-01-01

    Full Text Available In this paper are reported the results of an experimental campaign carried out on a post tensioned concrete beam with the aim of investigating the possibility to detect early warning signs of deterioration basing on static and/or dynamic tests. The beam was tested in several configurations aimed to reproduce several different phases of the ‘life’ of the beam: the original undamaged state, increasing loss of tension in the post tensioning cables, a strengthening intervention carried out by means of a second tension cable, formation of further cracks on the strengthened beam. Responses of the beam were measured by an extensive set of instruments consisting of accelerometers, inclinometers, displacement transducers, strain gauges and optical fibres. The paper discusses the tests program and the dynamic characterization of the beam in the different damage scenarios. The modal properties of the beam in the different phases were recovered basing on the responses recorded on the beam during sine-sweep and impact hammer tests. The variation of the first modal frequency was studied to investigate the sensitivity of this parameter to both the cracking of the concrete section and the tension in the cables and also to compare results given by different types of experimental tests.

  8. Deleted in Malignant Brain Tumors 1 (DMBT1 is present in hyaline membranes and modulates surface tension of surfactant

    Directory of Open Access Journals (Sweden)

    Griese Matthias

    2007-10-01

    Full Text Available Abstract Background Deleted in Malignant Brain Tumors 1 (DMBT1 is a secreted scavenger receptor cysteine-rich protein that binds various bacteria and is thought to participate in innate pulmonary host defense. We hypothesized that pulmonary DMBT1 could contribute to respiratory distress syndrome in neonates by modulating surfactant function. Methods DMBT1 expression was studied by immunohistochemistry and mRNA in situ hybridization in post-mortem lungs of preterm and full-term neonates with pulmonary hyaline membranes. The effect of human recombinant DMBT1 on the function of bovine and porcine surfactant was measured by a capillary surfactometer. DMBT1-levels in tracheal aspirates of ventilated preterm and term infants were determined by ELISA. Results Pulmonary DMBT1 was localized in hyaline membranes during respiratory distress syndrome. In vitro addition of human recombinant DMBT1 to the surfactants increased surface tension in a dose-dependent manner. The DMBT1-mediated effect was reverted by the addition of calcium depending on the surfactant preparation. Conclusion Our data showed pulmonary DMBT1 expression in hyaline membranes during respiratory distress syndrome and demonstrated that DMBT1 increases lung surface tension in vitro. This raises the possibility that DMBT1 could antagonize surfactant supplementation in respiratory distress syndrome and could represent a candidate target molecule for therapeutic intervention in neonatal lung disease.

  9. Depression, automatic thoughts, alexithymia, and assertiveness in patients with tension-type headache.

    Science.gov (United States)

    Yücel, Basak; Kora, Kaan; Ozyalçín, Süleyman; Alçalar, Nilüfer; Ozdemir, Ozay; Yücel, Aysen

    2002-03-01

    The role of psychological factors related to headache has long been a focus of investigation. The aim of this study was to evaluate depression, automatic thoughts, alexithymia, and assertiveness in persons with tension-type headache and to compare the results with those from healthy controls. One hundred five subjects with tension-type headache (according to the criteria of the International Headache Society classification) and 70 controls were studied. The Beck Depression Inventory, Automatic Thoughts Scale, Toronto Alexithymia Scale, and Rathus Assertiveness Schedule were administered to both groups. Sociodemographic variables and headache features were evaluated via a semistructured scale. Compared with healthy controls, the subjects with headache had significantly higher scores on measures of depression, automatic thoughts, and alexithymia and lower scores on assertiveness. Subjects with chronic tension-type headache had higher depression and automatic thoughts scores than those with episodic tension-type headache. These findings suggested that persons with tension-type headache have high depression scores and also may have difficulty with expression of their emotions. Headache frequency appears to influence the likelihood of coexisting depression.

  10. Needle Decompression of Tension Pneumothorax with Colorimetric Capnography.

    Science.gov (United States)

    Naik, Nimesh D; Hernandez, Matthew C; Anderson, Jeff R; Ross, Erika K; Zielinski, Martin D; Aho, Johnathon M

    2017-11-01

    The success of needle decompression for tension pneumothorax is variable, and there are no objective measures assessing effective decompression. Colorimetric capnography, which detects carbon dioxide present within the pleural space, may serve as a simple test to assess effective needle decompression. Three swine underwent traumatically induced tension pneumothorax (standard of care, n = 15; standard of care with needle capnography, n = 15). Needle thoracostomy was performed with an 8-cm angiocatheter. Similarly, decompression was performed with the addition of colorimetric capnography. Subjective operator assessment of decompression was recorded and compared with true decompression, using thoracoscopic visualization for both techniques. Areas under receiver operating curves were calculated and pairwise comparison was performed to assess statistical significance (P pneumothorax, that is, the absence of any pathologic/space-occupying lesion, in 100% of cases (10 of 10 attempts). Standard of care needle decompression was detected by operators in 9 of 15 attempts (60%) and was detected in 3 of 10 attempts when tension pneumothorax was not present (30%). True decompression, under direct visualization with thoracoscopy, occurred 15 of 15 times (100%) with capnography, and 12 of 15 times (80%) without capnography. Areas under receiver operating curves were 0.65 for standard of care and 1.0 for needle capnography (P = .002). Needle decompression with colorimetric capnography provides a rapid, effective, and highly accurate method for eliminating operator bias for tension pneumothorax decompression. This may be useful for the treatment of this life-threatening condition. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  11. Superdualities, brane tensions and massive IIA/IIB duality

    International Nuclear Information System (INIS)

    Lavrinenko, I.V.; Lue, H.; Pope, C.N.; Stelle, K.S.

    1999-01-01

    The gauge transformations of p-form fields in supergravity theories acquire a non-commuting character when one introduces potentials both for the theory's original field strengths and for their duals. This has previously been shown in the 'doubled' formalism for maximal supergravities, where a generalised duality relation between original and dual field strengths replaces the equations of motion. In the doubled formalism, the gauge transformations generate a superalgebra, and the corresponding symmetries have accordingly been called 'superdualities'. The corresponding Noether charges form a representation of the cohomology ring on the space-time manifold. In this paper, we show that the gauge symmetry superalgebra implies certain non-trivial relations among the various p-brane tensions, which can straightforwardly be read off from the superalgebra commutation relations. This provides an elegant derivation of the brane-tension relations purely within a given theory, without the need to make use of duality relations between different theories, such as the type IIA/IIB T-duality, although the results are consistent with such dualities. We present the complete set of brane-tension relations in M-theory, in the type IIA and type IIB theories, and in all the lower-dimensional maximal supergravities. We also construct a doubled formalism for massive type IIA supergravity, and this enables us to obtain the brane-tension relations involving the D8-brane, purely within the framework of the massive IIA theory. We also obtain explicit transformations for the nine-dimensional T-duality between the massive type IIA theory and the Scherk-Schwarz reduced type IIB theory

  12. The Tension-Stiffening Contribution of NSM CFRP to the Behavior of Strengthened RC Beams

    Directory of Open Access Journals (Sweden)

    Ahmad Azim Shukri

    2015-07-01

    Full Text Available Tension stiffening is a characteristic behavior of reinforced concrete (RC beams which is directly affected by the bond-slip property of steel bar and concrete interfaces. A beam strengthened with a near-surface mounted (NSM technique would be even more affected by tension stiffening, as the NSM reinforcement also possess a bond-slip property. Yet assessing how much the tension stiffening of NSM contributes to the behavior of RC beams is difficult due to the fact that bond-slip effects cannot be directly incorporated into a strain-based moment-curvature analysis. As such, the tension stiffening is typically incorporated through various empirical formulations, which can require a great deal of testing and calibrations to be done. In this paper a relatively new method, which can be called the mechanics-based segmental approach, is used to directly simulate the tension stiffening effect of NSM reinforcements on RC beams, without the need for empirical formulations to indirectly simulate the tension stiffening. Analysis shows that the tension stiffening of NSM fiber reinforced polymer (FRP contributes a significant portion to the stiffness and strength of the strengthened RC beam not only during serviceability, but at all load levels.

  13. The Tension-Stiffening Contribution of NSM CFRP to the Behavior of Strengthened RC Beams.

    Science.gov (United States)

    Shukri, Ahmad Azim; Darain, Kh Mahfuz Ud; Jumaat, Mohd Zamin

    2015-07-08

    Tension stiffening is a characteristic behavior of reinforced concrete (RC) beams which is directly affected by the bond-slip property of steel bar and concrete interfaces. A beam strengthened with a near-surface mounted (NSM) technique would be even more affected by tension stiffening, as the NSM reinforcement also possess a bond-slip property. Yet assessing how much the tension stiffening of NSM contributes to the behavior of RC beams is difficult due to the fact that bond-slip effects cannot be directly incorporated into a strain-based moment-curvature analysis. As such, the tension stiffening is typically incorporated through various empirical formulations, which can require a great deal of testing and calibrations to be done. In this paper a relatively new method, which can be called the mechanics-based segmental approach, is used to directly simulate the tension stiffening effect of NSM reinforcements on RC beams, without the need for empirical formulations to indirectly simulate the tension stiffening. Analysis shows that the tension stiffening of NSM fiber reinforced polymer (FRP) contributes a significant portion to the stiffness and strength of the strengthened RC beam not only during serviceability, but at all load levels.

  14. Estimating the right allocation of resources on weekends and public holidays in Green Zone using hybrid methods

    Science.gov (United States)

    Yusoff, Nazhatul Sahima Mohd; Liong, Choong-Yeun; Ismail, Wan Rosmanira; Noh, Abu Yazid Md; Noor, Nur Amalina Mohd

    2018-04-01

    Long patient waiting time and congestion is a major problem faced by Green Zone in Emergency Department at Hospital Universiti Sains Malaysia (EDHUSM) especially during weekends and public holidays. Even though the Green Zone is servicing only the non-critical patients, patient waiting time, causing the department fails to achieve its Key Performance Indicator (KPI). The long waiting time is due to the insufficient resources provided during the weekends and public holidays versus the large number of patients. Currently, only two doctors supported by two nurses are scheduled for every shift during weekends and public holidays. The numbers of patients are higher during weekends and public holidays as compared to weekdays, but the scheduled number of doctors and nurses are the same as weekdays. Therefore, this study presents a hybrid method to estimate the right number of doctors and nurses for improving the services of the Green Zone during weekends and public holidays. Fifty scenarios based on current and proposed schedules of doctors and nurses are simulated and analysed using the hybrid method of Discrete Event Simulation (DES) and Data Envelopment Analysis (DEA). Banker, Charnes and Cooper (BCC) input-oriented model and Super-Efficiency models of DEA were used to analyse the efficiency of the scenarios. The results show that the best schedule is a combination of four doctors supported by four nurses in every shift during weekends and public holidays for the Green Zone. The findings show that such schedule will not only help the department to achieve its KPI but also enable a more optimal utilization of the resources.

  15. Normal tension glaucoma and Alzheimer disease

    DEFF Research Database (Denmark)

    Bach-Holm, Daniella; Kessing, Svend Vedel; Mogensen, Ulla Brasch

    2012-01-01

    Purpose: To investigate whether normal tension glaucoma (NTG) is associated with increased risk of developing dementia/Alzheimer disease (AD). Methods: A total of 69 patients with NTG were identified in the case note files in the Glaucoma Clinic, University Hospital of Copenhagen (Rigshospitalet...

  16. Tension-induced vesicle fusion: pathways and pore dynamics

    DEFF Research Database (Denmark)

    Shillcock, Julian C.

    2008-01-01

    and eventually opens a pore to complete the fusion process. In pathway II, at higher tension, a stalk is formed during the fusion process that is then transformed by transmembrane pore formation into a fusion pore. Whereas the latter pathway II resembles stalk pathways as observed in other simulation studies......, fusion pathway I, which does not involve any stalk formation, has not been described previously to the best of our knowledge. A statistical analysis of the various processes shows that fusion is the dominant pathway for releasing the tension of the vesicles. The functional dependence of the observed...

  17. Numerical tension adjustment of x-ray membrane to represent goat skin kompang

    Science.gov (United States)

    Siswanto, Waluyo Adi; Abdullah, Muhammad Syiddiq Bin

    2017-04-01

    This paper presents a numerical membrane model of traditional musical instrument kompang that will be used to find the parameter of membrane tension of x-ray membrane representing the classical goat-skin membrane of kompang. In this study, the experiment towards the kompang is first conducted in an acoustical anechoic enclosure and in parallel a mathematical model of the kompang membrane is developed to simulate the vibration of the kompang membrane in polar coordinate by implementing Fourier-Bessel wave function. The wave equation in polar direction in mode 0,1 is applied to provide the corresponding natural frequencies of the circular membrane. The value of initial and boundary conditions in the function is determined from experiment to allow the correct development of numerical equation. The numerical mathematical model is coded in SMath for the accurate numerical analysis as well as the plotting tool. Two kompang membrane cases with different membrane materials, i.e. goat skin and x-ray film membranes with fixed radius of 0.1 m are used in the experiment. An alternative of kompang's membrane made of x-ray film with the appropriate tension setting can be used to represent the sound of traditional goat-skin kompang. The tension setting of the membrane to resemble the goat-skin is 24N. An effective numerical tool has been develop to help kompang maker to set the tension of x-ray membrane. In the future application, any tradional kompang with different size can be replaced by another membrane material if the tension is set to the correct tension value. The developed numerical tool is useful and handy to calculate the tension of the alternative membrane material.

  18. Nonlinear analysis of reinforced concrete beam with/without tension stiffening effect

    International Nuclear Information System (INIS)

    Dede, T.; Ayvaz, Y.

    2009-01-01

    The aim of this paper is to do materially nonlinear failure analysis of RC beam by using finite element method. In the finite element modeling, two different approaches and different tension stress-strain models with/without tension stiffening effect are used by considering two different mesh sizes. In the first approach, the material matrices of concrete and reinforcement are constructed separately, and then superimposed to obtain the element stiffness matrix. In the second approach, the reinforcement is assumed to be uniformly distributed throughout the beam. So, the beam is modeled as a single composite element with increasing the modulus of elasticity of concrete by considering the reinforcement ratio. For these two approaches, elastic-perfectly plastic stress-strain relationship is used for concrete in compression. For the concrete in tension, a stress-strain relationship with/without tension stiffening is used. It is concluded that the approaches and the models considered in this study can be effectively used in the materially nonlinear analysis of RC beams.

  19. Membrane tension controls adhesion positioning at the leading edge of cells.

    Science.gov (United States)

    Pontes, Bruno; Monzo, Pascale; Gole, Laurent; Le Roux, Anabel-Lise; Kosmalska, Anita Joanna; Tam, Zhi Yang; Luo, Weiwei; Kan, Sophie; Viasnoff, Virgile; Roca-Cusachs, Pere; Tucker-Kellogg, Lisa; Gauthier, Nils C

    2017-09-04

    Cell migration is dependent on adhesion dynamics and actin cytoskeleton remodeling at the leading edge. These events may be physically constrained by the plasma membrane. Here, we show that the mechanical signal produced by an increase in plasma membrane tension triggers the positioning of new rows of adhesions at the leading edge. During protrusion, as membrane tension increases, velocity slows, and the lamellipodium buckles upward in a myosin II-independent manner. The buckling occurs between the front of the lamellipodium, where nascent adhesions are positioned in rows, and the base of the lamellipodium, where a vinculin-dependent clutch couples actin to previously positioned adhesions. As membrane tension decreases, protrusion resumes and buckling disappears, until the next cycle. We propose that the mechanical signal of membrane tension exerts upstream control in mechanotransduction by periodically compressing and relaxing the lamellipodium, leading to the positioning of adhesions at the leading edge of cells. © 2017 Pontes et al.

  20. Evaluation on Dorsey Method in Surface Tension Measurement of Solder Liquids Containing Surfactants

    Science.gov (United States)

    Zhao, Xingke; Xie, Feiming; Fan, Jinsheng; Liu, Dayong; Huang, Jihua; Chen, Shuhai

    2018-06-01

    With the purpose of developing a feasible approach for measuring the surface tension of solders containing surfactants, the surface tension of Sn-3Ag-0.5Cu-xP solder alloys, with various drop sizes as well as different phosphorus (P) content, was evaluated using the Dorsey method based on the sessile drop test. The results show that the accuracy of the surface tension calculations depends on both of sessile drop size and the liquid metal composition. With a proper drop size, in the range of 4.5 mm to 5.3 mm in equivalent spherical diameters, the deviation of the surface tension calculation can be limited to 1.43 mN·m-1 and 6.30 mN·m-1 for SnAgCu and SnAgCu-P, respectively. The surface tension of SnAgCu-xP solder alloys decreases quickly to a minimum value when the P content reaches 0.5 wt% and subsequently increases slowly with the P content further increasing. The formation of a P-enriched surface layer and Sn4P3 intermetallic phases is regarded to be responsible for the decreasing and subsequent increasing of surface tension, respectively.

  1. Inflation and late-time acceleration in braneworld cosmological models with varying brane tension

    International Nuclear Information System (INIS)

    Wong, K.C.; Cheng, K.S.; Harko, T.

    2010-01-01

    Braneworld models with variable brane tension λ introduce a new degree of freedom that allows for evolving gravitational and cosmological constants, the latter being a natural candidate for dark energy. We consider a thermodynamic interpretation of the varying brane tension models, by showing that the field equations with variable λ can be interpreted as describing matter creation in a cosmological framework. The particle creation rate is determined by the variation rate of the brane tension, as well as by the brane-bulk energy-matter transfer rate. We investigate the effect of a variable brane tension on the cosmological evolution of the Universe, in the framework of a particular model in which the brane tension is an exponentially dependent function of the scale factor. The resulting cosmology shows the presence of an initial inflationary expansion, followed by a decelerating phase, and by a smooth transition towards a late accelerated de Sitter type expansion. The varying brane tension is also responsible for the generation of the matter in the Universe (reheating period). The physical constraints on the model parameters, resulting from the observational cosmological data, are also investigated. (orig.)

  2. Managing Tensions And Forging Creative Synergies Between ...

    African Journals Online (AJOL)

    Managing Tensions And Forging Creative Synergies Between Indigenous And Modern Settlement Planning Concepts And Practices: Lessons For The Design And Planning For Sustainable Settlements And Built-Forms In Southern Africa.

  3. Guidelines for controlled trials of drugs in tension-type headache: second edition

    DEFF Research Database (Denmark)

    Bendtsen, L; Bigal, M E; Cerbo, R

    2010-01-01

    and chronic tension-type headache have been published, providing new information on trial methodology for this disorder. Furthermore, the classification of the headaches, including tension-type headache, has been revised. These developments support the need for also revising the guidelines for drug treatments......The Clinical Trials Subcommittee of the International Headache Society published its first edition of the guidelines on controlled trials of drugs in tension-type headache in 1995. These aimed 'to improve the quality of controlled clinical trials in tension-type headache', because 'good quality...... controlled trials are the only way to convincingly demonstrate the efficacy of a drug, and form the basis for international agreement on drug therapy'. The Committee published similar guidelines for clinical trials in migraine and cluster headache. Since 1995 several studies on the treatment of episodic...

  4. Indentation of a floating elastic sheet: geometry versus applied tension.

    Science.gov (United States)

    Box, Finn; Vella, Dominic; Style, Robert W; Neufeld, Jerome A

    2017-10-01

    The localized loading of an elastic sheet floating on a liquid bath occurs at scales from a frog sitting on a lily pad to a volcano supported by the Earth's tectonic plates. The load is supported by a combination of the stresses within the sheet (which may include applied tensions from, for example, surface tension) and the hydrostatic pressure in the liquid. At the same time, the sheet deforms, and may wrinkle, because of the load. We study this problem in terms of the (relatively weak) applied tension and the indentation depth. For small indentation depths, we find that the force-indentation curve is linear with a stiffness that we characterize in terms of the applied tension and bending stiffness of the sheet. At larger indentations, the force-indentation curve becomes nonlinear and the sheet is subject to a wrinkling instability. We study this wrinkling instability close to the buckling threshold and calculate both the number of wrinkles at onset and the indentation depth at onset, comparing our theoretical results with experiments. Finally, we contrast our results with those previously reported for very thin, highly bendable membranes.

  5. Mechanical Behavior of BFRP-Steel Composite Plate under Axial Tension

    Directory of Open Access Journals (Sweden)

    Yunyu Li

    2014-06-01

    Full Text Available Combining the advantages of basalt fiber-reinforced polymer (BFRP material and steel material, a novel BFRP-steel composite plate (BSP is proposed, where a steel plate is sandwiched between two outer BFRP laminates. The main purpose of this research is to investigate the mechanical behavior of the proposed BSP under uniaxial tension and cyclic tension. Four groups of BSP specimens with four different BFRP layers and one control group of steel plate specimens were prepared. A uniaxial tensile test and a cyclic tensile test were conducted to determine the initial elastic modulus, postyield stiffness, yield strength, ultimate bearing capacity and residual deformation. Test results indicated that the stress-strain curve of the BSP specimen was bilinear prior to the fracture of the outer BFRP, and the BSP specimen had stable postyield stiffness and small residual deformation after the yielding of the inner steel plate. The postyield modulus of BSP specimens increased almost linearly with the increasing number of outer BFRP layers, as well as the ultimate bearing capacity. Moreover, the predicted results from the selected models under both monotonic tension and cyclic tension were in good agreement with the experimental data.

  6. Hybrid mimics and hybrid vigor in Arabidopsis

    Science.gov (United States)

    Wang, Li; Greaves, Ian K.; Groszmann, Michael; Wu, Li Min; Dennis, Elizabeth S.; Peacock, W. James

    2015-01-01

    F1 hybrids can outperform their parents in yield and vegetative biomass, features of hybrid vigor that form the basis of the hybrid seed industry. The yield advantage of the F1 is lost in the F2 and subsequent generations. In Arabidopsis, from F2 plants that have a F1-like phenotype, we have by recurrent selection produced pure breeding F5/F6 lines, hybrid mimics, in which the characteristics of the F1 hybrid are stabilized. These hybrid mimic lines, like the F1 hybrid, have larger leaves than the parent plant, and the leaves have increased photosynthetic cell numbers, and in some lines, increased size of cells, suggesting an increased supply of photosynthate. A comparison of the differentially expressed genes in the F1 hybrid with those of eight hybrid mimic lines identified metabolic pathways altered in both; these pathways include down-regulation of defense response pathways and altered abiotic response pathways. F6 hybrid mimic lines are mostly homozygous at each locus in the genome and yet retain the large F1-like phenotype. Many alleles in the F6 plants, when they are homozygous, have expression levels different to the level in the parent. We consider this altered expression to be a consequence of transregulation of genes from one parent by genes from the other parent. Transregulation could also arise from epigenetic modifications in the F1. The pure breeding hybrid mimics have been valuable in probing the mechanisms of hybrid vigor and may also prove to be useful hybrid vigor equivalents in agriculture. PMID:26283378

  7. WORRY, ANXIETY AND TENSION — IMPORTANCE ...

    African Journals Online (AJOL)

    Enrique

    cognitive. Tension: Increased and unpleasant motor and psychological activity or a state of mental or ... MRC Research Unit on Anxiety and Stress. Disorders ... and brain imaging. Worry ... serve an adaptive function to the daily challenges of our environment. ... connection to physical symptoms ... Experience-conditioning.

  8. The Effect of Pre-Tension on Deformation Behaviour of Natural Fabric Reinforced Composite

    Directory of Open Access Journals (Sweden)

    Paulė BEKAMPIENĖ

    2011-03-01

    Full Text Available In the fiber-reinforced composites industry together with the promotion of environmental friendly production, synthetic materials are attempted to be replaced by renewable, biodegradable and recyclable materials. The most important challenge is to improve strength and durability of these materials. Matrix that supports the fiber-reinforcement in composite generally is brittle and deformation causes fragmentation of the matrix. Pre-tension of reinforcement is a well-known method to increase tensile strength of woven material. The current study develops the idea to use pre-tension of woven fabric in order to improve quality and strength properties of the obtained composite. Natural (cotton fiber and synthetic (glass fiber woven fabrics were investigated. The pressure forming operation was carried out in order to study clamping imposed strain variation across the surface of woven fabric. The uniaxial tension test of single-layer composite specimens with and without pre-tension was performed to study the effect of pre-tension on strength properties of composite. The results have shown that pre-tension imposed by clamping is an effective method to improve the quality of shaped composite parts (more smoothed contour is obtained and to increase the strength properties of composite reinforced by woven natural fabric. After pre-tension the tensile strength at break increased in 12 % in warp direction, in 58 % in weft direction and in 39 % in bias direction.http://dx.doi.org/10.5755/j01.ms.17.1.250

  9. Strand Tension Control in Anchor Span for Suspension Bridge Using Dynamic Balance Theory

    Directory of Open Access Journals (Sweden)

    Da Wang

    Full Text Available Abstract Strand tension control is essential in suspension bridge safety. However, few quantitative studies have examined the bending rigidity and boundary condition behavior of strands in the anchor span of suspension bridges because of their special structure and complex configuration. In this paper, a new calculation method for strand tension is explored by using dynamic balance theory to determine the effect of bending rigidity and boundary conditions. The accuracy and effectiveness of the proposed method are tested and confirmed with verification examples and application on Nanxi Yangtze Suspension Bridge in China. The results indicated that only low-order frequency calculation could be used to calculate the strand tension without considering the effect of bending rigidity to ensure control accuracy. The influence of bending rigidity on the control precision is related to the tension and the length of the strands, which is significantly determined by the specific value between the stress rigidity and the bending rigidity. The uncertain boundary conditions of the anchor span cable, which are fixed between consolidated and hinged, also have a major effect on the control accuracy. To improve the accuracy of strand tension control, the least squares method is proposed during the tension construction control of the anchor span. This approach can significantly improve the accuracy of the tension control of the main cable strand. Some recommendations for future bridge analysis are provided based on the results of this study.

  10. Segmentation of 3D microPET images of the rat brain via the hybrid gaussian mixture method with kernel density estimation.

    Science.gov (United States)

    Chen, Tai-Been; Chen, Jyh-Cheng; Lu, Henry Horng-Shing

    2012-01-01

    Segmentation of positron emission tomography (PET) is typically achieved using the K-Means method or other approaches. In preclinical and clinical applications, the K-Means method needs a prior estimation of parameters such as the number of clusters and appropriate initialized values. This work segments microPET images using a hybrid method combining the Gaussian mixture model (GMM) with kernel density estimation. Segmentation is crucial to registration of disordered 2-deoxy-2-fluoro-D-glucose (FDG) accumulation locations with functional diagnosis and to estimate standardized uptake values (SUVs) of region of interests (ROIs) in PET images. Therefore, simulation studies are conducted to apply spherical targets to evaluate segmentation accuracy based on Tanimoto's definition of similarity. The proposed method generates a higher degree of similarity than the K-Means method. The PET images of a rat brain are used to compare the segmented shape and area of the cerebral cortex by the K-Means method and the proposed method by volume rendering. The proposed method provides clearer and more detailed activity structures of an FDG accumulation location in the cerebral cortex than those by the K-Means method.

  11. Robust Tension Control of Strip for 5-Stand Tandem Cold Mills

    Directory of Open Access Journals (Sweden)

    Behrooz Shafiei

    2014-01-01

    Full Text Available Tandem cold rolling process is a nonlinear complex system with external and internal uncertainties and significant disturbances. The improvement in the quality of the final output depends on the control strategy of centerline thickness and interstand tension. This paper focuses on interstand tension control problem in 5-stand tandem cold rolling mills. Tension dynamics can be described by a nominal model perturbed by parametric uncertainties. In order to overcome the model uncertainties and external disturbances, suboptimal H∞ and μ controllers are proposed and the Hankel-norm approximation is used to reduce the order of μ controller. The performance of the proposed controllers is demonstrated by some simulations.

  12. [Case of tension pneumothorax associated with asthma attack during general anesthesia].

    Science.gov (United States)

    Komasawa, Nobuyasu; Ueki, Ryusuke; Kusuyama, Kazuki; Okano, Yukari; Tatara, Tsuneo; Tashiro, Chikara

    2010-05-01

    We report a case of tension pneumothorax associated with asthma attack during general anesthesia. An 86-year-old woman with dementia underwent cataract surgery under general anesthesia. At 70 min after the start of operation, airway pressure suddenly increased from 19 to 28 cm HO2O. In spite of bag ventilation with 100% oxygen, Sp(O2) decreased to 81%. Chest-Xp showed typical image of tension pneumothorax. Chest drainage was immediately performed, after which Pa(O2) recovered soon. She was extubated on postoperative day 1 without any neurological disorder. Hyperinflation of fragile alveoli by mechanical ventilation was likely a cause of tension pneumothorax.

  13. Why Clothes Don't Fall Apart: Tension Transmission in Staple Yarns

    Science.gov (United States)

    Warren, Patrick B.; Ball, Robin C.; Goldstein, Raymond E.

    2018-04-01

    The problem of how staple yarns transmit tension is addressed within abstract models in which the Amontons-Coulomb friction laws yield a linear programing (LP) problem for the tensions in the fiber elements. We find there is a percolation transition such that above the percolation threshold the transmitted tension is in principle unbounded. We determine that the mean slack in the LP constraints is a suitable order parameter to characterize this supercritical state. We argue the mechanism is generic, and in practical terms, it corresponds to a switch from a ductile to a brittle failure mode accompanied by a significant increase in mechanical strength.

  14. Z(2) vortices and the SU(2) string tension

    International Nuclear Information System (INIS)

    Goepfert, M.

    1981-01-01

    Topologically determined Z(2) variables in pure SU(2) lattice gauge theory are discussed. They count the number of 'vortex souls'. The high temperature expansion for the corresponding Z(2) loops is examined. They obey an area law. The coefficient of the area is shown to be equal to the string tension to all orders of the high temperature expansion. This shows that the string tension is determined by the probability distribution of the vortex souls, at least in the high temperature region. The dependence of the string tension α(β,h) on an external field h that is coupled to the Z(2) field strength is calculated to lowest order of the high temperature expansion. In this approximation, α(β,h) is determined by the free energy of a 2-dimensional Ising model in an external magnetic field 1/2log(β/4tanhh) at an inverse temperature 1/2log3/4π = 0.429. (orig.)

  15. Microdamage in polycrystalline ceramics under dynamic compression and tension

    International Nuclear Information System (INIS)

    Zhang, K.S.; Zhang, D.; Feng, R.; Wu, M.S.

    2005-01-01

    In-grain microplasticity and intergranular microdamage in polycrystalline hexagonal-structure ceramics subjected to a sequence of dynamic compression and tension are studied computationally using the Voronoi polycrystal model, by which the topological heterogeneity and material anisotropy of the crystals are simulated explicitly. The constitutive modeling considers crystal plasticity by basal slip, intergranular shear damage during compression, and intergranular mode-I cracking during tension. The model parameters are calibrated with the available shock compression and spall strength data on polycrystalline α-6H silicon carbide. The numerical results show that microplasticity is a more plausible micromechanism for the inelastic response of the material under shock compression. On the other hand, the spallation behavior of the shocked material can be well predicted by intergranular mode-I microcracking during load reversal from dynamic compression to tension. The failure process and the resulting spall strength are, however, affected strongly by the intensity of local release heterogeneity induced by heterogeneous microplasticity, and by the grain-boundary shear damage during compression

  16. DNA:DNA hybridization studies on the pink-pigmented facultative methylotrophs.

    Science.gov (United States)

    Hood, D W; Dow, C S; Green, P N

    1987-03-01

    The genomic relatedness among 36 strains of pink-pigmented facultatively methylotrophic bacteria (PPFMs) was estimated by determination of DNA base composition and by DNA:DNA hybridization studies. A reproducible hybridization system was developed for the rapid analysis of multiple DNA samples. Results indicated that the PPFMs comprise four major and several minor homology groups, and that they should remain grouped in a single genus, Methylobacterium.

  17. Interfacial tensions of binary mixtures of ethanol with octane, decane, dodecane, and tetradecane

    International Nuclear Information System (INIS)

    Mejia, Andres; Cartes, Marcela; Segura, Hugo

    2011-01-01

    Highlights: → Experimental interfacial tensions in binary mixtures with aneotropic behavior. → Experimental interfacial tensions for ethanol + hydrocarbon mixtures. → Aneotropic displacement in ethanol mixtures. - Abstract: This contribution is devoted to the experimental characterization of interfacial tensions of a representative group of binary mixtures pertaining to the (ethanol + linear hydrocarbon) series (i.e. octane, decane, dodecane, and tetradecane). Experimental measurements were isothermically performed using a maximum differential bubble pressure technique, which was applied over the whole mole fraction range and over the temperature range 298.15 K < T/K < 318.15 K. Experimental results show that the interfacial tensions of (ethanol + octane or decane) negatively deviate from the linear behavior and that sharp minimum points on concentration, or aneotropes, are observed for each isotherm. The interfacial tensions of (ethanol + dodecane or tetradecane), in turn, are characterized by combined deviations from the linear behavior, and inflecting behavior observed on concentration for each isotherm. The experimental evidence also shows that these latter mixtures are close to exhibit aneotropy. For the case of (ethanol + octane or decane) mixtures, aneotropy was clearly induced by the similarity of the interfacial tension values of the constituents. The inflecting behavior of the interfacial tensions of (ethanol + dodecane or tetradecane), in turn, was observed in the vicinity of the coordinates of the critical point of these mixtures, thus pointing to the fact that the quasi-aneotropic singularity that affects these mixtures was provoked by the proximity of an immiscibility gap of the liquid phase. Finally, the experimental data of interfacial tensions were smoothed with the Scott-Myers expansion, from which it is possible to conclude that the observed aneotropic concentrations weakly depend on temperature for all the analyzed mixtures.

  18. Spreading of oil on water in the surface-tension regime

    Energy Technology Data Exchange (ETDEWEB)

    Camp, D.W.; Berg, J.C.

    1987-11-01

    Data which describe the unidirectional spreading of several pure oils and oil-surfactant mixtures on water in the surface-tension regime are reported. Leading-edge position and profiles of velocity, thickness and film tension are given as functions of time. The data are consistent with the numerical similarity solution of Foda and Cox (1980), although the measured dependence of the film tension on the film thickness often differs from the equilibrium relationship. The configuration of the oil film near the spreading origin may be either a coherent multimolecular layer or a multitude of thinning, outward-moving lenses surrounded by monolayer. The pure oils show an acceleration zone connecting the slow-moving inner region to a fast-moving outer region, while the oil-surfactant mixtures show a much more gradual increase in film velocity.

  19. Tourniquet pressures: strap width and tensioning system widths.

    Science.gov (United States)

    Wall, Piper L; Coughlin, Ohmar; Rometti, Mary; Birkholz, Sarah; Gildemaster, Yvonne; Grulke, Lisa; Sahr, Sheryl; Buising, Charisse M

    2014-01-01

    Pressure distribution over tourniquet width is a determinant of pressure needed for arterial occlusion. Different width tensioning systems could result in arterial occlusion pressure differences among nonelastic strap designs of equal width. Ratcheting Medical Tourniquets (RMTs; m2 inc., http://www.ratcheting buckles.com) with a 1.9 cm-wide (Tactical RMT) or 2.3 cm-wide (Mass Casualty RMT) ladder were directly compared (16 recipients, 16 thighs and 16 upper arms for each tourniquetx2). Then, RMTs were retrospectively compared with the windlass Combat Application Tourniquet (C-A-T ["CAT"], http://combattourniquet.com) with a 2.5 cm-wide internal tensioning strap. Pressure was measured with an air-filled No. 1 neonatal blood pressure cuff under each 3.8 cm-wide tourniquet. RMT circumferential pressure distribution was not uniform. Tactical RMT pressures were not higher, and there were no differences between the RMTs in the effectiveness, ease of use ("97% easy"), or discomfort. However, a difference did occur regarding tooth skipping of the pawl during ratchet advancement: it occurred in 1 of 64 Tactical RMT applications versus 27 of 64 Mass Casualty RMT applications. CAT and RMT occlusion pressures were frequently over 300 mmHg. RMT arm occlusion pressures (175-397 mmHg), however, were lower than RMT thigh occlusion pressures (197-562 mmHg). RMT effectiveness was better with 99% reached occlusion and 1% lost occlusion over 1 minute versus the CAT with 95% reached occlusion and 28% lost occlusion over 1 minute. RMT muscle tension changes (up to 232 mmHg) and pressure losses over 1 minute (24±11 mmHg arm under strap to 40±12 mmHg thigh under ladder) suggest more occlusion losses may have occurred if tourniquet duration was extended. The narrower tensioning system Tactical RMT has better performance characteristics than the Mass Casualty RMT. The 3.8 cm-wide RMTs have some pressure and effectiveness similarities and differences compared with the CAT. Clinically

  20. Current and emerging concepts in muscle tension dysphonia: a 30-month review.

    Science.gov (United States)

    Altman, Kenneth W; Atkinson, Cory; Lazarus, Cathy

    2005-06-01

    The modern theory of hoarseness is that there are multifactorial etiologies contributing to the voice problem. The hypothesis of this study is that muscle tension dysphonia is multifactorial with various contributing etiologies. This project is a retrospective chart review of all patients seen in the Voice Speech and Language Service and Swallowing Center at our institution with a diagnosis of muscle tension (functional hypertensive) dysphonia over a 30-month period. A literature search and review is also performed regarding current and emerging concepts of muscle tension dysphonia. One hundred fifty subjects were identified (60% female, 40% male, with a mean age of 42.3 years). Significant factors in patient history believed to contribute to abnormal voice production were gastroesophageal reflux in 49%, high stress levels in 18%, excessive amounts of voice use in 63%, and excessive loudness demands on voice use in 23%. Otolaryngologic evaluation was performed in 82% of patients, in whom lesions, significant vocal fold edema, or paralysis/paresis was identified in 52.3%. Speech pathology assessment revealed poor breath support, inappropriately low pitch, and visible cervical neck tension in the majority of patients. Inappropriate intensity was observed in 23.3% of patients. This set of multiple contributing factors is discussed in the context of current and emerging understanding of muscle tension dysphonia. Results confirm multifactorial etiologies contributing to hoarseness in the patients identified with muscle tension dysphonia. An interdisciplinary approach to treating all contributing factors portends the best prognosis.