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1

Filament winding  

NASA Astrophysics Data System (ADS)

The major aspects of filament winding are discussed, emphasizing basic reinforcement and matrix materials, winding procedures, process controls, and cured composite properties. Fiberglass (E-glass and S-glass strengths are 500,000 and 665,000 psi respectively) and polyester resins are the principal reinforcement constituent materials. Graphite and aramid reinforcements are being used more frequently, primarily for the more critical pressure vessels. Matrix systems are most commonly based on epoxy as it has superior mechanical properties, fatigue behavior, and heat resistance as compard with polyesters. A fiberglass overwrap of PVC pipe is an anticipated development in on-site winding and combination winding, and the compression molding of filament wound lay-ups will be investigated. The fabrication of weight-sensitive structural components may be achieved by using such moldings.

Shibley, A. M.

2

Filament winding - Waking the sleeping giant  

NASA Technical Reports Server (NTRS)

The use of filament winding (FW) in the production of aerospace composite structures is examined. The FW process applies spools of fiber and prepreg tow or prepreg tape to a male mandrel; the process is more efficient and cost effective than metallic construction. The fibers used in FW and the curing process are explained. The reduced storage and fabrication costs that result from FW are discussed. The use of FW to produce a filament-wound case for a solid rocket motor and the substructure and skin of an aircraft fuselage are described. Areas which require further development in order to expand the use of FW are listed and discussed.

Freeman, W. T., Jr.; Stein, B. A.

1985-01-01

3

Filament winding cylinders. I - Process model  

NASA Technical Reports Server (NTRS)

A model was developed which describes the filament winding process of composite cylinders. The model relates the significant process variables such as winding speed, fiber tension, and applied temperature to the thermal, chemical and mechanical behavior of the composite cylinder and the mandrel. Based on the model, a user friendly code was written which can be used to calculate (1) the temperature in the cylinder and the mandrel, (2) the degree of cure and viscosity in the cylinder, (3) the fiber tensions and fiber positions, (4) the stresses and strains in the cylinder and in the mandrel, and (5) the void diameters in the cylinder.

Lee, Soo-Yong; Springer, George S.

1990-01-01

4

Heat flow analysis in connection with thermoplastic filament winding  

Microsoft Academic Search

In thermoplastic filament winding the calculated rate of cooling is found to be in the order of 100000 degr.C\\/second at the bonding interface. Short range heat flow phenomena are analyzed, and the result provides a simple rule of thumb for practice, together with a winding speed dependant correction for glass and carbon fiber composites. This enables an easy method to

Anders Brage; Charles Lamrell

1988-01-01

5

Filament winding cylinders. III - Selection of the process variables  

NASA Technical Reports Server (NTRS)

By using the Lee-Springer filament winding model temperatures, degrees of cure, viscosities, stresses, strains, fiber tensions, fiber motions, and void diameters were calculated in graphite-epoxy composite cylinders during the winding and subsequent curing. The results demonstrate the type of information which can be generated by the model. It is shown, in reference to these results, how the model, and the corresponding WINDTHICK code, can be used to select the appropriate process variables.

Lee, Soo-Yong; Springer, George S.

1990-01-01

6

Filament winding S-glass/polyimide resin composite processing studies  

NASA Technical Reports Server (NTRS)

The work performed in selecting a TRW A-type polyimide resin that would be suitable for fabrication of filament wound reinforced plastic structures is described. Several different formulations were evaluated after which the P105AC formulation was selected as the most promising. Procedures then were developed for preparing P105AC/S-glass roving prepreg and for fabricating filament wound structural composites. Composites were fabricated and then tested in order to obtain tensile and shear strength information. Small, closed-end cylindrical pressure vessels then were fabricated using a stainless steel liner and end fittings with a P105AC/S-glass polar wound overwrap. These pressure vessels were cured in an air circulating oven without augmented pressure. It is concluded that the P105AC resin system is suitable for filament winding; that low void content, high strength composites are obtained by the filament winding process; and that augmented pressure is not required to effect the fabrication of filament wound P105AC composites.

Vaughan, R. W.; Jones, R. J.

1974-01-01

7

High performance thermoplastic composites fabricated by filament winding  

SciTech Connect

Filament winding processing has been applied to produce composite rings on the basis of FIT{reg_sign}-tows. Important steps in the process are the preheating of the tow within an infrared (IR) preheater and the subsequent heating by hot air at the consolidation point. To assess the bonding quality achieved by this process, axial compression and in-plane shear strength measurements of curved samples (sections of the rings wound) have been made. Furthermore results of modeling the heating processes of the tow are provided with the aim to draw conclusions about the preheater length, IR-power, and temperature of the heating air at the consolidation point.

Lauke, B.; Schoene, A. [Institute of Polymer Research, Dresden (Germany); Friedrich, K. [Univ. of Kaiserslautern (Germany). Institute for Composite Materials

1993-12-31

8

Filament winding cylinders. II - Validation of the process model  

NASA Technical Reports Server (NTRS)

Analytical and experimental studies were performed to validate the model developed by Lee and Springer for simulating the manufacturing process of filament wound composite cylinders. First, results calculated by the Lee-Springer model were compared to results of the Calius-Springer thin cylinder model. Second, temperatures and strains calculated by the Lee-Springer model were compared to data. The data used in these comparisons were generated during the course of this investigation with cylinders made of Hercules IM-6G/HBRF-55 and Fiberite T-300/976 graphite-epoxy tows. Good agreement was found between the calculated and measured stresses and strains, indicating that the model is a useful representation of the winding and curing processes.

Calius, Emilio P.; Lee, Soo-Yong; Springer, George S.

1990-01-01

9

Simulation of the geodesic and non-geodesic trajectories of the filament winding  

SciTech Connect

The analysis of simulation data plays a key role in the determination of the filament winding trajectories over the mandrel. Through simulation, not only the most appropriate filament winding for a specific purpose can be chosen, but also wrong winding configurations can be avoided. An interactive environment for the analysis of the filament winding has been developed and is briefly described. A suitable algorithm for computing geodesic and nongeodesic trajectories is presented. Analytical expressions for the determination of the winding angle law on a general axisymmetric surface of revolution are presented. Expressions to evaluate the maximum winding length to avoid the use of unproper winding parameters, initial winding angle and slippage tendency, are also presented.

Simoes, J.A.O.; Marques, A.T.; Castro, P.M.S.T. de [Universidade do Porto, Rua dos Bragas (Portugal)

1993-12-31

10

Development of Induction Machines in Wind Power Technology  

Microsoft Academic Search

This paper gives an overview of the development of the induction machine as a generator for wind turbines from the middle of the 20th century up to now. After a short history chapter the different energy conversion concepts are presented. At first a squirrel cage machine is direct coupled to the grid (Danish concept). To adjust the machine speed the

Stefan Soter; R. Wegener

2007-01-01

11

Fields of Opportunity: Wind Machines Return to the Plains  

ERIC Educational Resources Information Center

The last two decades have seen a rebirth of wind machines on the rural landscape. In ironic fashion the wind's kinetic energy has grown in significance through its ability to generate commercial amounts of electricity, the commodity that a few generations earlier hastened the demise of the old Great Plains windmill. Yet the reemergence of wind

Sowers, Jacob

2006-01-01

12

Is titin a 'winding filament'? A new twist on muscle contraction.  

PubMed

Recent studies have demonstrated a role for the elastic protein titin in active muscle, but the mechanisms by which titin plays this role remain to be elucidated. In active muscle, Ca(2+)-binding has been shown to increase titin stiffness, but the observed increase is too small to explain the increased stiffness of parallel elastic elements upon muscle activation. We propose a 'winding filament' mechanism for titin's role in active muscle. First, we hypothesize that Ca(2+)-dependent binding of titin's N2A region to thin filaments increases titin stiffness by preventing low-force straightening of proximal immunoglobulin domains that occurs during passive stretch. This mechanism explains the difference in length dependence of force between skeletal myofibrils and cardiac myocytes. Second, we hypothesize that cross-bridges serve not only as motors that pull thin filaments towards the M-line, but also as rotors that wind titin on the thin filaments, storing elastic potential energy in PEVK during force development and active stretch. Energy stored during force development can be recovered during active shortening. The winding filament hypothesis accounts for force enhancement during stretch and force depression during shortening, and provides testable predictions that will encourage new directions for research on mechanisms of muscle contraction. PMID:21900329

Nishikawa, Kiisa C; Monroy, Jenna A; Uyeno, Theodore E; Yeo, Sang Hoon; Pai, Dinesh K; Lindstedt, Stan L

2012-03-01

13

Intraseasonal variability in the summer South China Sea: Wind jet, cold filament, and recirculations  

Microsoft Academic Search

A recent study shows that the blockage of the southwest monsoon by the mountain range on the east coast of Indochina triggers a chain of ocean-atmospheric response, including a wind jet and cold filament in the South China Sea (SCS). We extend this climatological analysis by using higher temporal resolution (weekly) to study intraseasonal variability in summer. Our analysis shows

Shang-Ping Xie; Chueh-Hsin Chang; Qiang Xie; Dongxiao Wang

2007-01-01

14

High pressure gas storage capacities. Example of a solution using filament windings  

NASA Technical Reports Server (NTRS)

The use of epoxy resin fiber glass and economic factors affecting the choice of materials for gas storage are discussed. The physical nature of the filament windings are described together with the results obtained. It is demonstrated that a substantial reduction in mass and an enhanced level of safety can be assured at a competitive cost by storing gases in this way.

Phan, A.; Lamalle, J.

1981-01-01

15

Liquid oxygen-compatible filament-winding matrix resin  

NASA Technical Reports Server (NTRS)

Polyurethanes derived from hydroxy terminated polyperfluoro propylene oxide prepolymers were evaluated as matrix resins for filament wound composites which would be exposed to liquid (and 100% gaseous) oxygen environments. A number of structural modifications were brought about by variations in prepolymer molecular weight, and alternative curing agents which allowed retention of the oxygen compatibility. Although satisfactory performance was achieved at sub-ambient temperatures, the derived composites suffered considerable property loss at ambient or slightly elevated temperatures. To attain overall effectiveness of the composite system, upgrading of the polymer thermomechanical properties must first be achieved.

Harrison, E. S.

1973-01-01

16

Rotating Electric Machine Having a Toroidal Wound Motor Winding.  

National Technical Information Service (NTIS)

A rotor rotating electric machine having a toroidal winding assembly wound in a toroidal helix configuration. The toroidal winding includes four coils, each of which is wound in the form of a toroidal helix around a thin cylindrical ring. A rotor, coaxial...

K. H. Gutz

1981-01-01

17

Permanent magnet machine with windings having strand transposition  

DOEpatents

This document discusses, among other things, a stator with transposition between the windings or coils. The coils are free from transposition to increase the fill factor of the stator slots. The transposition at the end connections between an inner coil and an outer coil provide transposition to reduce circulating current loss. The increased fill factor reduces further current losses. Such a stator is used in a dual rotor, permanent magnet machine, for example, in a compressor pump, wind turbine gearbox, wind turbine rotor.

Qu, Ronghai (Clifton Park, NY); Jansen, Patrick Lee (Scotia, NY)

2009-04-21

18

Stator for a rotating electrical machine having multiple control windings  

DOEpatents

A rotating electric machine is provided which includes multiple independent control windings for compensating for rotor imbalances and for levitating/centering the rotor. The multiple independent control windings are placed at different axial locations along the rotor to oppose forces created by imbalances at different axial locations along the rotor. The multiple control windings can also be used to levitate/center the rotor with a relatively small magnetic field per unit area since the rotor and/or the main power winding provides the bias field.

Shah, Manoj R. (Latham, NY); Lewandowski, Chad R. (Amsterdam, NY)

2001-07-17

19

Filament Winding of Co-Extruded Polypropylene Tapes for Fully Recyclable All-Polypropylene Composite Products  

Microsoft Academic Search

The creation of high-strength co-extruded polypropylene (PP) tapes allows the production of recyclable “all-polypropylene”\\u000a (all-PP) composite products, with a large temperature processing window and a high fibre volume fraction. Available technologies\\u000a for all-PP composites are mostly based on manufacturing processes such as thermoforming of pre-consolidated sheets. The objective\\u000a of this research is to assess the potential of filament winding as

N. O. Cabrera; B. Alcock; E. T. J. Klompen; T. Peijs

2008-01-01

20

WindTech TV: Bonus Materials- Machine Control Circuits  

NSDL National Science Digital Library

This section of the Wind Technician TV website provides bonus materials pertaining to machine control circuits. Users can review content on topics like electrical theory, magnetics, ladder diagrams and start-stop interlock example. Clicking on a subtopic will launch a pop up window demonstrating the concept.

2013-07-01

21

Analysis of a bearingless machine with divided windings  

Microsoft Academic Search

This paper shows some characteristics of a bearingless three-phase induction motor with divided windings independently controlled to generate radial and rotational forces. The analysis of this device has been performed by a two-dimensional finite-element model which has allowed the prediction of the machine performances in terms of current, torque, and force behavior. Some preliminary experimental results have been used to

Jossana M. S. Ferreira; Mauro Zucca; Andrés O. Salazar; Lorenzo Donadio

2005-01-01

22

The Inertial Response of Induction-Machine-Based Wind Turbines  

Microsoft Academic Search

The inertial response of a generator is influenced by the sensitivity of the generator's electromagnetic torque to changes in the power system frequency. This paper deals with the inertial response of wind turbines employing induction-machine-based generators. A model of a field-oriented controlled doubly fed induction generator based on a fifth-order induction-generator model is described. The proposed model is implemented in

Alan Mullane; Mark O'Malley

2005-01-01

23

Design of a Lightweight Transverse Flux Permanent Magnet Machine for Direct-Drive Wind Turbines  

Microsoft Academic Search

The aim of this paper is to design a lightweight transverse flux permanent magnet (TFPM) machine for large scale direct-drive wind turbines. The requirements for suitable generator systems for wind turbines are discussed. Analytical modeling of TFPM machines is discussed by considering the machine parameters and the magnetic circuit. The proposed analytical model is verified by comparing it to results

Deok-Je Bang; Henk Polinder; Ghanshyam Shrestha; Jan Abraham Ferreira

2008-01-01

24

Fault tolerant switched reluctance machine for wind turbine blade pitch control  

Microsoft Academic Search

The paper's goal is to accomplish a study regarding the usefulness of a fault tolerant machine in wind turbine pitch control. The pitch control both helps to catch the wind at the optimal angle of attack of the blade's airfoil and to turn the blades out of the wind when maximum speed is exceeded. To fulfill this assignment electrical machines

Mircea RUBA; Loránd SZABÓ; Florin JURCA

2009-01-01

25

Sensors-less neural MPPT control of wind generators with induction machines  

Microsoft Academic Search

This paper presents a MPPT technique for high performance wind generator with induction machine based on the growing neural gas (GNG) network. Here a GNG network has been trained off-line to learn the turbine characteristic surface torque versus wind speed and machine speed, and implemented on-line to obtain the wind tangential speed on the basis of the estimated torque and

Maurizio Cirrincione; M. Pucci

2009-01-01

26

Pole-phase modulated toroidal winding for an induction machine  

DOEpatents

A stator (10) for an induction machine for a vehicle has a cylindrical core (12) with inner and outer slots (26, 28) extending longitudinally along the inner and outer peripheries between the end faces (22, 24). Each outer slot is associated with several adjacent inner slots. A plurality of toroidal coils (14) are wound about the core and laid in the inner and outer slots. Each coil occupies a single inner slot and is laid in the associated outer slot thereby minimizing the distance the coil extends from the end faces and minimizing the length of the induction machine. The toroidal coils are configured for an arbitrary pole phase modulation wherein the coils are configured with variable numbers of phases and poles for providing maximum torque for cranking and switchable to a another phase and pole configuration for alternator operation. An adaptor ring (36) circumferentially positioned about the stator improves mechanical strength, and provides a coolant channel manifold (34) for removing heat produced in stator windings during operation.

Miller, John Michael (Saline, MI); Ostovic, Vlado (Weinheim, DE)

1999-11-02

27

Broken Bar Detection in Synchronous Machines Based Wind Energy Conversion System  

E-print Network

Electrical machines are subject to different types of failures. Early detection of the incipient faults and fast maintenance may prevent costly consequences. Fault diagnosis of wind turbine is especially important because they are situated...

Rahimian, Mina Mashhadi

2012-10-19

28

Simulation of a doubly-fed induction machine for wind turbine generator fault analysis  

Microsoft Academic Search

For modern large wind farms, it is more and more interesting to design an efficient diagnostics system oriented to wind turbine generators based on doubly-fed induction machine (DFIM). In this paper, a complete system will be analyzed by suitable simulations to deeply study fault influence and to identify the best diagnostic procedure to perform predictive maintenance. All the research efforts

A. Yazidi; H. Henao; G. A. Capolino; D. Casadei; F. Filippetti; C. Rossi

2005-01-01

29

Development status of rotating machines employing superconducting field windings  

Microsoft Academic Search

Superconducting rotating machines have looked promising since multifilamentary niobium-titanium (NbTi) superconductors became available in the mid-1960s. Both dc homopolar and ac synchronous machines were successfully tested from the 1970s to the 1990s. Three different 70-MW generators were recently demonstrated by the SuperGM project in Japan. However, economic considerations with respect to competitive cost combined with the requirement for liquid helium

SWARN S. KALSI; KONRAD WEEBER; H. Takesue; CLIVE LEWIS; HEINZ-WERNER NEUMUELLER; RICHARD D. BLAUGHER

2004-01-01

30

Application of the AC Commutator Machine in Wind Energy Conversion Systems  

E-print Network

APPLICATION OF THE AC OOMM3TATOR MACHINE IN WIND ENERGY CONVKGION SYSTB3S A Thesis By SAMI GF33RGES EL-Jhl'3OUS Submitted to the Graduate College of Twas AW University in partial fulfillment of the requirement for the degree of MASTER... of using the AC three-phase Comsutator Nachine (ACCM) in Wind Energy Conversion Systems (WECS). A mathematical nudel of the ACCN is derived snd is used to study the performance char- acteristics of the machine. Of particular interest is the shunt ACCN...

El-Jamous, Sami Georges

2012-06-07

31

Cogging torque reduction in axial flux machines for small wind turbines  

Microsoft Academic Search

This paper presents a technique for cogging torque reduction in an axial-flux permanent-magnet (PM) generator suitable for use in a small wind turbine. These machines can be compact and have high power density; they are axially short with larger diameter which makes then very suitable for a wind turbine. The inherent cogging torque can cause problems during turbine start-up and

Min-Fu Hsieh; D. G. Dorrell; Yu-Han Yeh; Samsul Ekram

2009-01-01

32

Growing Neural Gas (GNG)Based Maximum Power Point Tracking for High-Performance Wind Generator With an Induction Machine  

Microsoft Academic Search

This paper presents a maximum power point track- ing (MPPT) technique for a high-performance wind generator with induction machine based on the growing neural gas (GNG) network. Here, a GNG network has been trained offline to learn the turbine characteristic surface torque versus wind speed and machine speed. It has been implemented online to perform the inversion of this function,

Maurizio Cirrincione; Marcello Pucci; Gianpaolo Vitale

2011-01-01

33

Research on Potential of Advanced Technology for Housing. A Building System Based on Filament Winding and New Developments in Water and Waste Management.  

ERIC Educational Resources Information Center

The University of Michigan and Aerojet Corporation report their development of a new building system which will offer the consumer a higher quality product at lower cost. To achieve this goal, the University-Aerojet proposal suggested filament winding (a process derived from the aerospace program for the manufacture of reinforced plastic…

Michigan Univ., Ann Arbor.

34

System for maintaining the alignment of mandrels in filament winding operations  

DOEpatents

The present invention is directed to a system for sensing and correcting the alignment of a mandrel being wound with filamentary material with respect to the filamentary material winding mechanism. A positioned reference pin attached to the mandrel is positioned in a beam of collimated light emanating from a laser so as to bisect the light beam and create a shadow therebetween. A pair of photocells are positioned to receive the bisected light beam with the shadow uniformly located between the photocells when the pin is in a selected position. The mandrel is supported in the selected position for the winding of a filamentary material by a position adjustable roller mechanism which is coupled by a screw drive to a reversible motor. Changes in the pin position such as caused by winding growth are sensed by the photocells to provide the displacement of the roller mechanism in the direction necessary to return the mandrel to the selected position.

Robinson, S.C.; Dodge, W.G.; Pollard, R.E.

1983-10-12

35

System for maintaining the alignment of mandrels in filament winding operations  

DOEpatents

The present invention is directed to a system for sensing and correcting the alignment of a mandrel being wound with filamentary material with respect to the filamentary material winding mechanism. A positioned reference pin attached to the mandrel is positioned in a beam of collimated light emanating from a laser so as to bisect the light beam and create a shadow therebetween. A pair of photocells are positioned to receive the bisected light beam with the shadow uniformly located between the photocells when the pin is in a selected position. The mandrel is supported in the selected position for the winding of a filamentary material by a position adjustable roller mechanism which is coupled by a screw drive to a reversible motor. Changes in the pin position such as caused by winding growth are sensed by the photocells to provide the displacement of the roller mechanism in the direction necessary to return the mandrel to the selected position.

Robinson, Samuel C. (Clinton, TN); Dodge, William G. (Oak Ridge, TN); Pollard, Roy E. (Powell, TN)

1984-01-01

36

Numerical simulation of kinetic Alfven waves to study filament formation and their nonlinear dynamics in solar wind and corona  

SciTech Connect

This paper presents a numerical simulation leading to the formation of intense magnetic filaments of kinetic Alfven waves (KAWs) in steady state when the nonlinearity arises due to ponderomotive effects and Joule heating. The nonlinear dynamical equation for the KAW satisfies the modified nonlinear Schroedinger equation. When the plain KAW is perturbed by a transverse perturbation, filamentary structures in solar wind and coronal holes are observed. By changing the parameters of the perturbation (such as the wave number and the phase factor), filamentary structures of KAW magnetic field have been observed. The effect of the change of the dimensionless transverse wave number {gamma} (normalized in terms of electron's collisionless skin depth of the KAW) plays a very important role on filamentary dynamics. Besides the study of the magnetic-field intensity, we have done various diagnostics such as phase portraits and surface plots, and also studied the power spectrum. The effect of changing the value of {gamma} on power spectrum is significant. The motion is found to be quasiperiodic and appears to be chaotic for different parametric regimes. The relevance of these studies in coronal heating and solar wind acceleration/turbulence has also been pointed out.

Singh, H.D.; Sharma, R.P. [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi-110016 (India)

2006-01-15

37

Analysis of a single-phase induction machine with a shifted auxiliary winding  

SciTech Connect

This paper extends the method of multiple reference frames to the analysis of asymmetrical induction motors with non-orthogonal stator windings, with particular emphasis on the permanent split capacitor (PSC) machine. The predictions of the method are verified by comparison to both experimental results and to results obtained using a machine variable computer simulation. Once verified, the method is used to derive the transfer function relating rotor speed to load torque disturbance, which is of particular interest when analyzing PSC machines driving compressor loads. It is shown that the transfer function exhibits a distinct resonant point, and that the magnitude of the resonant peak increases as the motor approaches synchronous speed. It is also shown that the magnitude of the resonant peak may be lowered by increasing rotational inertia or rotor resistance.

Walls, T.A. [Emerson Motor Co., St. Louis, MO (United States). Specialty Motor Div.] [Emerson Motor Co., St. Louis, MO (United States). Specialty Motor Div.; Sudhoff, S.D. [Univ. of Missouri, Rolla, MO (United States). Dept. of Electrical Engineering] [Univ. of Missouri, Rolla, MO (United States). Dept. of Electrical Engineering

1996-12-01

38

Multi-star multi-phase winding for a high power naval propulsion machine with low ripple torques  

E-print Network

1 Multi-star multi-phase winding for a high power naval propulsion machine with low ripple torques Permanent Magnet (SMPM) Machine designed for naval propulsion is proposed. The design objective of this high and to optimize the quality of the torque by reducing the electromagnetic torque ripples which underlie

Boyer, Edmond

39

Direct-Matrix-Converter-Based Drive for a Three-Phase Open-End-Winding AC Machine With Advanced Features  

Microsoft Academic Search

This paper describes how matrix converters (MCs), one at each side of a three-phase open-end-winding ac machine, achieve the following features simultaneously: 1) machine phase voltage up to 1.5 times the input phase voltage in the linear modulation mode, therefore extending the rated torque operation region to 150% of the rated speed of the machine; 2) peak voltage stress across

Ranjan K. Gupta; Krushna K. Mohapatra; Apurva Somani; Ned Mohan

2010-01-01

40

Growing Neural Gas (GNG) based Maximum Power Point Tracking for high performance VOC-FOC based wind generator system with an induction machine  

Microsoft Academic Search

This paper presents a MPPT technique for high performance wind generator with induction machine based on the Growing Neural Gas (GNG) network. Here a GNG network has been trained off-line to learn the turbine characteristic surface torque versus wind speed and machine speed, and implemented on-line so to perform the inversion of this function obtaining the wind free speed on

Maurizio Cirrincione; Marcello Pucci; Gianpaolo Vitale

2009-01-01

41

Analysis and mapping of monthly wind field patterns using machine learning  

NASA Astrophysics Data System (ADS)

Spatial prediction/mapping of wind speed patterns is important for both renewable resources and natural hazards studies. Many different approaches were proposed in the literature: deterministic science-based models, geostatistical interpolations, data driven modelling based on machine learning algorithms (artificial neural networks of different architectures, support vector machines). Deterministic (science-based or physical) models suffer from computational burden and are hardly applicable over fine grids in complex regions. Geostatistical models depend on modelling of spatial correlations and are limited to the low dimensional spaces. The present study focuses on the use of machine learning algorithms for spatial mapping of monthly average wind speed in Switzerland. The real data were provided by Meteoswiss and presented complex relationships with topography. The topographic information was derived by filtering the Swiss DEM and was necessary to correctly describe wind speed patterns. Additional input variables, highlighting ridges, canyons, exposed flanks, were stacked to spatial coordinates (X, Y, Z). However, the integration of these "geo-features" considerably increased the dimensionality of the original input space (~10-30). Therefore the use of machine learning methods became crucial for providing robust nonlinear predictions of high quality. The generic methodology used includes the following important steps: exploratory spatial data analysis, including variography and detection of spatially structured patterns; automatic features selection/scaling using the adaptive/anisotropic generalized regression neural networks (GRNN); optimization of model hyper-parameters by minimizing cross-validation error using iterative gradient-based algorithms; modelling (mapping) of the functional relationships between the spatial locations and topography, comprehensive analysis of the residuals and visual interpretation of the results. It was shown that anisotropic GRNN considerably outperforms its isotropic version. Stability of adaptive GRNN in selecting features was assessed by analyzing the variance of the proposed solutions. Other observations concern the variation of the predictability of wind speed during the year: lower in summer and higher in winter. Finally, the results were compared with a support vector regression (SVR), which is a well known non-linear and robust model efficient in high dimensional spaces. The research was partly supported by SNSF project No. 200020-121835.

Robert, Sylvain; Foresti, Loris; Kanevski, Mikhail

2010-05-01

42

A novel design of DC-AC electrical machine rotary converter for hybrid solar and wind energy applications  

NASA Astrophysics Data System (ADS)

This paper proposes the design of a new bi-directional DC-AC rotary converter machine to convert a d.c. voltage to three-phase voltage and vice-versa using a two-stage energy conversion machine. The rotary converter consists of two main stages which are combined into single frame. These two stages are constructed from three main electromagnetic components. The first inner electromagnetic component represents the input stage that enables the DC power generated by solar energy from photo-voltaic cells to be transformed by the second and third components electro-magnetically to produce multi-phase voltages at the output stage. At the same time, extra kinetic energy from wind, which is sufficiently available, can be added to existing torque on the second electromagnetic component. Both of these input energies will add up to the final energy generated at the output terminals. Therefore, the machine will be able to convert solar and wind energies to the output terminals simultaneously. If the solar energy is low, the available wind energy will be able to provide energy to the output terminals and at the same time charges the batteries which are connected as backup system. At this moment, the machine behaves as wind turbine. The energy output from the machine benefits from two energy sources which are solar and wind. At night when the solar energy is not available and also the load is low, the wind energy is able to charge the batteries and at the same time provides output electrical power to the remaining the load. Therefore, the proposed system will have high usage of available renewable energy as compared to separated wind or solar systems. MATLAB codes are used to calculate the required dimensions, the magnetic and electrical circuits parameters to design of the new bi-directional rotary converter machine.

Mohammed, K. G.; Ramli, A. Q.; Amirulddin, U. A. U.

2013-06-01

43

Eddy-current formulation for constructing transmission-line models for machine windings  

NASA Astrophysics Data System (ADS)

In this paper, an eddy-current formulation is used to determine the transmission-line parameters of a machine winding. It is shown that this formulation covers a broader frequency range than the commonly used low-frequency magnetostatic and high-frequency magnetodynamic approximations. The eddy-current formulation, however, suffers from large computation times and may lead to severe inaccuracies if the finite-element mesh does not resolve the skin depth, a modelling concern that does not exist for the traditional formulations. The three finite-element models are compared according to the accuracy of the resulting transmission-line model applied to the winding of a permanent-magnet synchronous machine. This article has been submitted as part of “NUMELEC 2008 - 6e Conférence Européenne sur les Méthodes Numériques en Électromagnétisme”, 8-10 December 2008, LiègeThis work has been carried out in the collaborative research group (Forschergruppe 575) “High-frequency parasitic effects in inverter-fed electrical drives” funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG).

de Gersem, H.; Henze, O.; Weiland, T.; Binder, A.

2010-03-01

44

Induction machine  

DOEpatents

A polyphase rotary induction machine for use as a motor or generator utilizing a single rotor assembly having two series connected sets of rotor windings, a first stator winding disposed around the first rotor winding and means for controlling the current induced in one set of the rotor windings compared to the current induced in the other set of the rotor windings. The rotor windings may be wound rotor windings or squirrel cage windings.

Owen, Whitney H. (Ogden, UT)

1980-01-01

45

Barriers to the use of wind energy machines: The present legal\\/regulatory regime and a preliminary assessment of some legal\\/political\\/societal problems  

Microsoft Academic Search

The present state of law and regulation at all levels of government that may affect wind energy machines is analyzed. Also analyzed and assessed is the state of analogous and related law and regulation, requirements at various levels of government, and international rules, as wind machines grow larger and\\/or are used in arrays. It suggests some potential impacts of the

R. F. Taubenfeld; H. J. Taubenfeld

1976-01-01

46

Tests of Wing Machine-Gun and Cannon Installations in the NACA Full-Scale Wind Tunnel, Special Report  

NASA Technical Reports Server (NTRS)

At the request of the Bureau of Aeronautics, an investigation was conducted in the full-scale wind tunnel of wing installations of .50-caliber machine guns and 20-millimeter cannons. The tests were made to determine the effect of various gun installations on the maximum lift and the high-speed drag of the airplane.

Czarnecki, K. R.; Guryansky, Eugene R.

1941-01-01

47

Investigation of Ice Shape Measurement Technique Based on Laser Sheet and Machine Vision in Icing Wind Tunnel  

Microsoft Academic Search

For the sake of developing an ice shape profilometer in icing wind tunnel, the technique of ice shape measurement based on laser sheet and machine vision is studied. The measurement principle and computing theory have been demonstrated in detail. The instrument projects a thin sheet of laser light onto an ice shape and uses high resolution CCD cameras to detect

Long Zhang; Longde Guo; Jianjun Yang

2009-01-01

48

Doubly-fed induction machine as generator in wind power plant: nonlinear control algorithms with direct decoupling  

Microsoft Academic Search

Currently the doubly fed induction machine (DFIM) is often used in wind power plants. The digital rotor current controller is always based on DFIM models linearized within a sampling period which does not correspond to the nonlinear nature of the DFIM. The paper deals with a nonlinear control scheme with direct decoupling and presents some first investigation results. This new

N. P. Quang; A. Dittrich; P. N. Lan

2005-01-01

49

Winding for the wind  

NASA Astrophysics Data System (ADS)

The mechanical properties and construction of epoxy-impregnated fiber-glass blades for wind turbines are discussed, along with descriptions of blades for the Mod 0A and Mod 5A WECS and design goals for a 4 kW WECS. Multicell structure combined with transverse filament tape winding reduces labor and material costs, while placing a high percentage of 0 deg fibers spanwise in the blades yields improved strength and elastic properties. The longitudinal, transverse, and shear modulus are shown to resist stresses exceeding the 50 lb/sq ft requirements, with constant stress resistance expected until fatigue failure is approached. Regression analysis indicates a fatigue life of 400 million operating cycles. The small WECS under prototype development features composite blades, nacelle, and tower. Rated at 5.7 kW in a 15 mph wind, the machine operates over a speed range of 9-53.9 mph and is expected to produce 16,200 kWh annually in a 10 mph average wind measured at 30 ft.

Weingart, O.

50

Winding for the wind  

NASA Technical Reports Server (NTRS)

The mechanical properties and construction of epoxy-impregnated fiber-glass blades for wind turbines are discussed, along with descriptions of blades for the Mod 0A and Mod 5A WECS and design goals for a 4 kW WECS. Multicell structure combined with transverse filament tape winding reduces labor and material costs, while placing a high percentage of 0 deg fibers spanwise in the blades yields improved strength and elastic properties. The longitudinal, transverse, and shear modulus are shown to resist stresses exceeding the 50 lb/sq ft requirements, with constant stress resistance expected until fatigue failure is approached. Regression analysis indicates a fatigue life of 400 million operating cycles. The small WECS under prototype development features composite blades, nacelle, and tower. Rated at 5.7 kW in a 15 mph wind, the machine operates over a speed range of 9-53.9 mph and is expected to produce 16,200 kWh annually in a 10 mph average wind measured at 30 ft.

Weingart, O.

1981-01-01

51

The use of doubly fed reluctance machines for large pumps and wind turbines  

Microsoft Academic Search

Brushless doubly fed induction machines (BDFIMs) have been extensively researched over because of the possibility of using a partially rated inverter in many applications with limited speed variations. However, the special cage rotor construction and substantial rotor losses is one of the key deficiencies of these machines. A similar and extremely interesting machine, the brushless doubly fed reluctance machine (BDFRM),

Milutin G. Jovanovic; Robert E. Betz; Jian Yu

2002-01-01

52

Use of a permeance model to predict force harmonic components and damper winding effects in salient-pole synchronous machines  

Microsoft Academic Search

This paper presents a combined finite-element and analytical modeling technique for the prediction of force-density harmonics in salient-pole synchronous machines. The model calculates the induced currents in the damper winding cage and includes their effect on force-density components in the solution. Use of a combined analytical and finite-element approach considerably reduces simulation times compared to full time-stepping finite-element solutions, while

Andrew M. Knight; Haran Karmaker; Konrad Weeber

2002-01-01

53

The use of doubly fed reluctance machines for large pumps and wind turbines  

Microsoft Academic Search

Brushless doubly-fed induction machines (BDFIMs) have been extensively researched over the last 15 years because of the possibility of using a partially rated inverter in many applications with limited speed variations. However, the special cage rotor construction and substantial rotor losses is one of the key deficiencies of these machines. A similar and extremely interesting machine, the brushless doubly-fed reluctance

M. G. Jovanovic; Robert E. Betz; Jian Yu

2001-01-01

54

Effects of Aerospace Contaminants on EPIKOTE(TM) 862 / EPIKURE(TM)-W Filament Winding Resin System: An Experimental Study  

NASA Astrophysics Data System (ADS)

This thesis presents the findings of extensive experiments to determine the effects of various common aerospace chemicals on EPIKOTE(TM) 862 (resin) and EPIKURE(TM) W (curing agent), a resin system utilized in filament wound carbon fiber reinforced polymer (CRP) structures. Test specimens of the neat resin system were fabricated and exposed for up to 6 months at room temperature to 11 fluids representing typical aerospace chemicals found on the flight line, and to 74°C tap water. Post exposure the samples were tested in torsion using a rheometer, which performed strain sweeps and frequency sweeps on all the samples. In addition, a subset of the samples received a temperatures sweep. The rheology test parameters represented the nominal stress levels CRP structures would expect to see in operation. In addition to the rheological tests, dimensional and mass measurements were made of the samples both pre and post exposure to study the physical changes due to the chemical interactions. Based on the results, a common detergent, MEK on structures manufactured with the 862W resin system should be prevented or severely limited. It had a significant impact on the performance of the resin system within 3 months, with no visible indications of the degradation. The resins system had good chemical resistance to all the other chemicals used in this study including hot water.

Moffet, Mitchell Lee

55

Helical filaments  

NASA Astrophysics Data System (ADS)

The shaping of laser-induced filamenting plasma channels into helical structures by guiding the process with a non-diffracting beam is demonstrated. This was achieved using a Bessel beam superposition to control the phase of an ultrafast laser beam possessing intensities sufficient to induce Kerr effect driven non-linear self-focusing. Several experimental methods were used to characterize the resulting beams and confirm the observed structures are laser air filaments.

Barbieri, Nicholas; Hosseinimakarem, Zahra; Lim, Khan; Durand, Magali; Baudelet, Matthieu; Johnson, Eric; Richardson, Martin

2014-06-01

56

The single-phase brushless doubly-fed machine as a generator for wind turbines  

Microsoft Academic Search

This paper proposes a single-phase variant of the Brushless Doubly-Fed Machine, the Single-Phase BDFM, SPB. Like the BDFM it is a variable speed generator which requires a converter rated at only a fraction of the machine rating, using structure with no brushes. Unlike the BDFM, most of its power is delivered directly into a single-phase grid connection. As such it

Thomas Logan; Teng Long; Richard McMahon

2011-01-01

57

Finite element field analysis of nonuniform surface contaminations on high voltage windings of electric machines  

Microsoft Academic Search

The analysis of electric fields in insulation systems containing conductive materials such as surface contaminations or grading tapes requires the solution of the complex Laplace equation. This paper presents two techniques of modeling thin conductive layers on the insulation of high voltage electric machines with electrodynamic finite element simulations. Case studies are performed to illustrate the benefits of employing finite

K. Weeber; M. Stutt; J. Dymond; R. Rehder

1996-01-01

58

FINAL REPORT ON CONTROL ALGORITHM TO IMPROVE THE PARTIAL-LOAD EFFICIENCY OFSURFACE PM MACHINES WITH FRACTIONAL-SLOT CONCENTRATED WINDINGS  

SciTech Connect

Surface permanent magnet (SPM) synchronous machines using fractional-slot concentrated windings are being investigated as candidates for high-performance traction machines for automotive electric propulsion systems. It has been shown analytically and experimentally that such designs can achieve very wide constant-power speed ratios (CPSR) [1,2]. This work has shown that machines of this type are capable of achieving very low cogging torque amplitudes as well as significantly increasing the machine power density [3-5] compared to SPM machines using conventional distributed windings. High efficiency can be achieved in this class of SPM machine by making special efforts to suppress the eddy-current losses in the magnets [6-8], accompanied by efforts to minimize the iron losses in the rotor and stator cores. Considerable attention has traditionally been devoted to maximizing the full-load efficiency of traction machines at their rated operating points and along their maximum-power vs. speed envelopes for higher speeds [9,10]. For example, on-line control approaches have been presented for maximizing the full-load efficiency of PM synchronous machines, including the use of negative d-axis stator current to reduce the core losses [11,12]. However, another important performance specification for electric traction applications is the machine's efficiency at partial loads. Partial-load efficiency is particularly important if the target traction application requires long periods of cruising operation at light loads that are significantly lower than the maximum drive capabilities. While the design of the machine itself is clearly important, investigation has shown that this is a case where the choice of the control algorithm plays a critical role in determining the maximum partial-load efficiency that the machine actually achieves in the traction drive system. There is no evidence that this important topic has been addressed for this type of SPM machine by any other authors. This topic takes on even greater significance for fractional-slot concentrated-winding SPM machine designs. In particular, maximizing the torque/power density of this class of SPM machines typically leads to machine designs with high numbers of poles. The resulting high electrical frequencies can easily result in high stator core losses unless special care is taken during the machine design process. The purpose of this report is to discuss a modified vector control algorithm for a fractional-slot concentrated winding SPM machine that has been developed to maximize the machine's partial-load efficiency over a wide range of operating conditions. For purposes of this discussion, a 55 kW (peak) SPM machine designed to meet requirements established in the US FreedomCar program [13] is used as the basis for demonstrating the proposed technique. A combination of closed-form analysis [14] and finite element analysis (FEA) is used during this investigation.

Reddy, P.B.; Jahns, T.M.

2007-04-30

59

Final Report on Control Algorithm to Improve the Partial-Load Efficiency of Surface PM Machines with Fractional-Slot Concentrated Windings  

SciTech Connect

Surface permanent magnet (SPM) synchronous machines using fractional-slot concentrated windings are being investigated as candidates for high-performance traction machines for automotive electric propulsion systems. It has been shown analytically and experimentally that such designs can achieve very wide constant-power speed ratios (CPSR) [1,2]. This work has shown that machines of this type are capable of achieving very low cogging torque amplitudes as well as significantly increasing the machine power density [3-5] compared to SPM machines using conventional distributed windings. High efficiency can be achieved in this class of SPM machine by making special efforts to suppress the eddy-current losses in the magnets [6-8], accompanied by efforts to minimize the iron losses in the rotor and stator cores. Considerable attention has traditionally been devoted to maximizing the full-load efficiency of traction machines at their rated operating points and along their maximum-power vs. speed envelopes for higher speeds [9,10]. For example, on-line control approaches have been presented for maximizing the full-load efficiency of PM synchronous machines, including the use of negative d-axis stator current to reduce the core losses [11,12]. However, another important performance specification for electric traction applications is the machine's efficiency at partial loads. Partial-load efficiency is particularly important if the target traction application requires long periods of cruising operation at light loads that are significantly lower than the maximum drive capabilities. While the design of the machine itself is clearly important, investigation has shown that this is a case where the choice of the control algorithm plays a critical role in determining the maximum partial-load efficiency that the machine actually achieves in the traction drive system. There is no evidence that this important topic has been addressed for this type of SPM machine by any other authors. This topic takes on even greater significance for fractional-slot concentrated-winding SPM machine designs. In particular, maximizing the torque/power density of this class of SPM machines typically leads to machine designs with high numbers of poles. The resulting high electrical frequencies can easily result in high stator core losses unless special care is taken during the machine design process. The purpose of this report is to discuss a modified vector control algorithm for a fractional-slot concentrated winding SPM machine that has been developed to maximize the machine's partial-load efficiency over a wide range of operating conditions. For purposes of this discussion, a 55 kW (peak) SPM machine designed to meet requirements established in the US FreedomCar program [13] is used as the basis for demonstrating the proposed technique. A combination of closed-form analysis [14] and finite element analysis (FEA) is used during this investigation.

McKeever, John W [ORNL; Reddy, Patel [University of Wisconsin; Jahns, Thomas M [ORNL

2007-05-01

60

FUZZY LOGIC BASED INTELLIGENT CONTROL OF A VARIABLE SPEED CAGE MACHINE WIND GENERATION SYSTEM  

EPA Science Inventory

The paper describes a variable-speed wind generation system where fuzzy logic principles are used to optimize efficiency and enhance performance control. A squirrel cage induction generator feeds the power to a double-sided pulse width modulated converter system which either pump...

61

Fuzzy logic based intelligent control of a variable speed cage machine wind generation system  

Microsoft Academic Search

The paper describes a variable speed wind generation system where fuzzy logic principles are used for efficiency optimization and performance enhancement control. A squirrel cage induction generator feeds the power to a double-sided pulse width modulated converter system which pumps power to a utility grid or can supply to an autonomous system. The generation system has fuzzy logic control with

M. G. Simoes; B. K. Bose; R. J. Spiegel

1997-01-01

62

Wind turbine power electronics and electrical machines: On lightning protection simulation  

Microsoft Academic Search

This paper presents an overview of wind energy in Portugal and briefly describes the Portuguese Lightning Location System. Some aspects of lightning activity in Portugal are discussed. The method for risk assessment due to lightning flashes to earth is performed by the computer program LPS 2008 developed in Visual Basic by the authors. LPS 2008 is based on well established

R. B. Rodrigues; V. M. F. Mendes; J. P. S. Catalao

2008-01-01

63

Performance analysis of various configurations of Switched Reluctance Machine for wind energy applications  

Microsoft Academic Search

Climate change is a contemporary issue and the international communities have accepted the dangers of green house gas emissions. Renewable energy is one of the hot topics when it comes to dealing with green house gas emissions treatments. Wind generation is one of the renewable energy power sources that helps in reducing the carbon di oxide from our atmosphere and

E. Annie Elisabeth Jebaseeli; D. Susitra

2010-01-01

64

FUZZY LOGIC BASED INTELLIGENT CONTROL OF A VARIABLE SPEED CAGE MACHINE WIND GENERATION SYSTEM  

EPA Science Inventory

The report gives results of a demonstration of the successful application of fuzzy logic to enhance the performance and control of a variable-speed wind generation system. A squirrel cage induction generator feeds the power to either a double-sided pulse-width modulation converte...

65

Filament turbulence  

NASA Astrophysics Data System (ADS)

How much information do you need to distinguish between different mechanisms for spatiotemporal chaos in three-dimensions? In this talk, I will show that the observation of the dynamics on the surface of a medium can be sufficient. Studying mechanisms for filament turbulence in the context of reaction-diffusion media, we found numerically that two major classes of instabilities leave a very different signature on what can be observed on the surface of a three-dimensional medium. These results are of direct relevance in the context of ventricular fibrillation - a turbulent electrical wave activity that destroys the coherent contraction of the ventricular muscle and its main pumping function leading to sudden cardiac death. While it has been proposed that the three-dimensional structure of the heart plays an important role in this type of filament turbulence, only the surface of the heart is currently accessible to experimental observation preventing the study of the full dynamics. Our results suggest that such observations might be sufficient.

Davidsen, Joern

2010-03-01

66

Detection of stator winding faults in induction machines using flux and vibration analysis  

NASA Astrophysics Data System (ADS)

This work aims at presenting the detection and diagnosis of electrical faults in the stator winding of three-phase induction motors using magnetic flux and vibration analysis techniques. A relationship was established between the main electrical faults (inter-turn short circuits and unbalanced voltage supplies) and the signals of magnetic flux and vibration, in order to identify the characteristic frequencies of those faults. The experimental results showed the efficiency of the conjugation of these techniques for detection, diagnosis and monitoring tasks. The results were undoubtedly impressive and can be adapted and used in real predictive maintenance programs in industries.

Lamim Filho, P. C. M.; Pederiva, R.; Brito, J. N.

2014-01-01

67

A Sensorless Adaptive Stator Winding Temperature Estimator for Mains-Fed Induction Machines With Continuous-Operation Periodic Duty Cycles  

Microsoft Academic Search

An induction machine's thermal behavior is determined by various machine components with dissimilar thermal characteristics. When a model with a single thermal time constant is used to characterize the machine's thermal behavior under periodic duty cycles, the magnitude of the thermal time constant needs to be adjusted according to the duty cycles to reflect the machine's dominant thermal dynamics during

Zhi Gao; Thomas G. Habetler; Ronald G. Harley; Roy S. Colby

2008-01-01

68

Analysis and design of a coreless permanent-magnet machine considering the winding shape by using a lumped equivalent magnetic circuit model  

NASA Astrophysics Data System (ADS)

A simple and rapid analysis and design method is proposed for a coreless permanent magnet machine (CPMM) using a hexagonal winding (HW). The HW, which combines a rectangular winding (RTW) and rhombic winding (RBW), can compensate for the disadvantages and maximize the advantages of the RTW and RBW. The CPMM is typically analyzed using complex differential equations or a timeconsuming finite element analysis (FEA). To address this problem, a relatively simpler and less timeconsuming analysis method is proposed by using a lumped equivalent magnetic circuit (LEMC) model. Furthermore, an effect of winding angle on a motor performance is analyzed via precise inspection of the relationship between the variables of the HW and the characteristics of motor. The validity and usefulness of the proposed method are verified via FEA and experiment.

Seo, Jung-Moo; Jung, In-Soung; Jung, Hyun-Kyo; Ro, Jong-Suk

2014-05-01

69

Winding for the wind  

Microsoft Academic Search

The mechanical properties and construction of epoxy-impregnated fiber-glass blades for wind turbines are discussed, along with descriptions of blades for the Mod 0A and Mod 5A WECS and design goals for a 4 kW WECS. Multicell structure combined with transverse filament tape winding reduces labor and material costs, while placing a high percentage of 0 deg fibers spanwise in the

O. Weingart

1981-01-01

70

Proceedings of the 2008 International Conference on Electrical Machines Paper ID 1434 DFIG-Based Wind Turbine Fault Diagnosis  

E-print Network

-Based Wind Turbine Fault Diagnosis Using a Specific Discrete Wavelet Transform E. Al-Ahmar1,2 , M for electrical and mechanical fault diagnosis in a DFIG-based wind turbine. The investigated technique unambiguously diagnose faults under transient conditions. Index Terms--Wind turbine, Doubly-Fed Induction

Boyer, Edmond

71

A Comparative Evaluation of Automated Solar Filament Detection  

NASA Astrophysics Data System (ADS)

We present a comparative evaluation for automated filament detection in H? solar images. By using metadata produced by the Advanced Automated Filament Detection and Characterization Code (AAFDCC) module, we adapted our trainable feature recognition (TFR) module to accurately detect regions in solar images containing filaments. We first analyze the AAFDCC module's metadata and then transform it into labeled datasets for machine-learning classification. Visualizations of data transformations and classification results are presented and accompanied by statistical findings. Our results confirm the reliable event reporting of the AAFDCC module and establishes our TFR module's ability to effectively detect solar filaments in H? solar images.

Schuh, M. A.; Banda, J. M.; Bernasconi, P. N.; Angryk, R. A.; Martens, P. C. H.

2014-07-01

72

Millikelvin Lab Machine Shop  

E-print Network

Millikelvin Lab OP105­112 Machine Shop OP132 Resistive Magnet Shop CICC Winding Area Transformers This building is home to the Millikelvin lab, the control room, the resistive magnet and machine shops, the CICC@magnet.fsu.edu (850) 644-4378 (850) 644-0534 2 MACHINE SHOP OP132 Vaughan Williams (A114*) williams

McQuade, D. Tyler

73

Wind energy conversion  

Microsoft Academic Search

Effective utilization of wind energy requires systematic studies of the sites available for the location of wind energy conversion systems and careful evaluation of the type and size of machines to be used. The present paper describes an approach currently in use for the siting of wind generators. It describes also the aerodynamic features of various types of wind machines

A. A. Fejer

1978-01-01

74

Comparison of 5th order and 3rd order machine models for doubly fed induction generator (DFIG) wind turbines  

Microsoft Academic Search

With increasing concern over climate change, a number of countries have implemented new renewable energy targets, which require significant amounts of wind generation. It is now recognized that much of this new wind generation plant will be variable speed type using doubly fed induction generators (DFIG). In order to investigate the impacts of these DFIG installations on the operation and

J. B. Ekanayake; L. Holdsworth; N. Jenkins

2003-01-01

75

PowerformerTM-experiences from the application of extruded solid dielectric cables in the stator winding of rotating machines  

Microsoft Academic Search

ABB has developed a new class of generators, PowerformerTM which are able to deliver electric power directly at transmission voltage levels. This is achieved by changing from traditional stator windings with rectangular conductors to windings with circular conductors based on proven high voltage cable technology with solid extruded dielectric. The paper discusses the concept of Powerformer and some of the

Mats Leijon; Stefan G. Johansson; Fredrik Owman; Stefan Alfredson; Thommy Karlsson; Sture Lindahl; C. Parkegren; S. Thoren

2000-01-01

76

Externally refuelled optical filaments  

NASA Astrophysics Data System (ADS)

Plasma channels produced in air through femtosecond laser filamentation hold great promise for a number of applications, including remote sensing, attosecond physics and spectroscopy, channelling microwaves and lightning protection. In such settings, extended filaments are desirable, yet their longitudinal span is limited by dissipative processes. Although various techniques aiming to prolong this process have been explored, the substantial extension of optical filaments remains a challenge. Here, we experimentally demonstrate that the natural range of a plasma column can be enhanced by at least an order of magnitude when the filament is prudently accompanied by an auxiliary beam. In this arrangement, the secondary low-intensity `dressing' beam propagates linearly and acts as a distributed energy reservoir, continuously refuelling the optical filament. Our approach offers an efficient and viable route towards the generation of extended light strings in air without inducing premature wave collapse or an undesirable beam break-up into multiple filaments.

Scheller, Maik; Mills, Matthew S.; Miri, Mohammad-Ali; Cheng, Weibo; Moloney, Jerome V.; Kolesik, Miroslav; Polynkin, Pavel; Christodoulides, Demetrios N.

2014-04-01

77

Multiple coupled circuit modeling of induction machines  

Microsoft Academic Search

A multiple coupled circuit model is presented for simulation of induction machines with both arbitrary winding layout and\\/or unbalanced operating conditions. The model is derived by means of winding functions. No symmetry is assumed. The parameters of the model are calculated directly from the geometry and winding layout of the machine. The behavior of an induction machine during starting is

X. Luo; Yuefeng Liao; H. Toliyat; A. El-Antably; T.A. Lipo

1993-01-01

78

Multiple coupled circuit modeling of induction machines  

Microsoft Academic Search

A new multiple coupled circuit model is presented for simulation of induction machines with both arbitrary winding layout and\\/or unbalanced operating conditions. The model is derived by means of winding functions. No symmetry is assumed. The parameters of the model are calculated directly from the geometry and winding layout of the machine. The behavior of an induction machine during starting

Xiaogang Luo; Yuefeng Liao; H. A. Toliyat; A. El-Antably; T.A. Lipo

1995-01-01

79

Processing and thermal properties of filament wound carbon-carbon composites for impact shell application  

NASA Astrophysics Data System (ADS)

The performance and safety of the radioisotope power source depend in part on the thermal and impact properties of the materials used in the general purpose heat source (GPHS) through the use of an impact shell, thermal insulation and an aeroshell. Results from an earlier study indicate the importance of circumferential fibers to the mechanical properties of cylindrical filament wound carbon-carbon composites for the impact shell application. Based on this study, an investigation was initiated to determine the processing characteristics and the mechanical and thermal response of three filament wound configurations with different percentages of circumferential fibers: 50%, 66% and 80%. The performs were fabricated using a 3-D filament winding machine followed by five cycles of resin impregnation and carbonization. In this paper, the processing sequence and the resulting microstructures of the composites will be described. The thermal conductivity values of the composites as a function of fiber configuration and density will be discussed. These results will be compared with the fine-weave pierced-fabric (FWPF) material and carbon-bonded carbon-fiber insulation. Finally, the relevance of the new configurations for applications in the general purpose heat source (GPHS) will also be inferred. .

Zee, Ralph; Romanoski, Glenn; Gale, H. Shyam; Wang, Hsin

2001-02-01

80

Winds  

NSDL National Science Digital Library

In this problem-based learning (PBL) scenario, students prepare a presentation for investors showing how their fishing company has a significant advantage because it locates upwelling zones and fishing areas using TRMM (Tropical Rainfall Measuring Mission) and other satellite data. Prior to launching the PBL, students learn about wind: the topics of air pressure, coriolis effect, upwelling and the role of differential heating on the atmosphere are explored in classroom demonstrations. Materials required include a beaker, coffee grounds, drinking straw, balloon, flashlight, and turntable. The resource includes teacher background information, glossary, assessment rubric, and an appendix introducing problem-based learning.

81

Wind Energy: An Engineering Survey  

Microsoft Academic Search

This paper presents an extensive survey of literature about wind energy and wind machines, their design and their applications. The paper intends to provide those who plan for energy policy with thorough information about this renewable type of energy and the available machines that convert wind energy into useful mechanical or electrical work. The machines which are available at present

M. N. NAHAS; A. S. MOHAMAD; M. AKYURT; A. K. EL-KALAY

1987-01-01

82

Lightning Protection for Rotating Machines  

Microsoft Academic Search

The high monetary value and low insulation levels of rotating machines make it necessary to employ special protection. A rotating machine can be conceived as a transmission line with distributed constants, the essential difference being that the machine winding is wound back on itself in the form of turns, which may permit high voltage across the turn-to-turn insulation. The installation

G. D. McCann; E. Beck; L. A. Finzi

1944-01-01

83

The Cooling of Electric Machines  

Microsoft Academic Search

The elevation in temperature of the windings of any electric machine due to the internal heat losses is usually the dominating factor in limiting the rating of the machine. This limitation found in the heating, is primarily due to the effects of high temperatures on the various types of insulation used in such machines. The American Institute of Electrical Engineers

George E. Luke

1923-01-01

84

Cardiac thin filament regulation  

PubMed Central

Myocardial contraction is initiated upon the release of calcium into the cytosol from the sarcoplasmic reticulum following membrane depolarization. The fundamental physiological role of the heart is to pump an amount blood that is determined by the prevailing requirements of the body. The physiological control systems employed to accomplish this task include regulation of heart rate, the amount of calcium release, and the response of the cardiac myofilaments to activator calcium ions. Thin filament activation and relaxation dynamics has emerged as a pivotal regulatory system tuning myofilament function to the beat-to-beat regulation of cardiac output. Maladaptation of thin filament dynamics, in addition to dysfunctional calcium cycling, is now recognized as an important cellular mechanism causing reduced cardiac pump function in a variety of cardiac diseases. Here, we review current knowledge regarding protein–protein interactions involved in the dynamics of thin filament activation and relaxation and the regulation of these processes by protein kinase-mediated phosphorylation. PMID:18421471

Kobayashi, Tomoyoshi; Jin, Lei; de Tombe, Pieter P.

2010-01-01

85

Aerogel-supported filament  

DOEpatents

The present invention is a thin filament embedded in a low density aerogel for use in radiation detection instruments and incandescent lamps. The aerogel provides a supportive matrix that is thermally and electrically nonconductive, mechanically strong, highly porous, gas-permeable, and transparent to ionizing radiation over short distances. A low density, open-cell aerogel is cast around a fine filament or wire, which allows the wire to be positioned with little or no tension and keeps the wire in place in the event of breakage. The aerogel support reduces the stresses on the wire caused by vibrational, gravitational, electrical, and mechanical forces. 6 Figs.

Wuest, C.R.; Tillotson, T.M.; Johnson, C.V. III

1995-05-16

86

Aerogel-supported filament  

DOEpatents

The present invention is a thin filament embedded in a low density aerogel for use in radiation detection instruments and incandescent lamps. The aerogel provides a supportive matrix that is thermally and electrically nonconductive, mechanically strong, highly porous, gas-permeable, and transparent to ionizing radiation over short distances. A low density, open-cell aerogel is cast around a fine filament or wire, which allows the wire to be positioned with little or no tension and keeps the wire in place in the event of breakage. The aerogel support reduces the stresses on the wire caused by vibrational, gravitational, electrical, and mechanical forces.

Wuest, Craig R. (Danville, CA); Tillotson, Thomas M. (Tracy, CA); Johnson, III, Coleman V. (Dallas, TX)

1995-01-01

87

Reversibility of laser filamentation  

E-print Network

We investigate the reversibility of laser filamentation, a self-sustained, non-linear propagation regime including dissipation and time-retarded effects. We show that even losses related to ionization marginally affect the possibility of reverse propagating ultrashort pulses back to the initial conditions, although they make it prone to finite-distance blow-up susceptible to prevent backward propagation.

Nicolas Berti; Wahb Ettoumi; Jérôme Kasparian; Jean-Pierre Wolf

2014-01-13

88

The aeroelastic behaviour of hot-wire anemometer filaments in an air stream  

Microsoft Academic Search

The motion of a hot-wire filament is analysed by treating it as an elastically bowed column subjected to lateral wind loads. The elastic bow is caused by thermal expansion. This model is firstly investigated for static wind loads and the non-linear differential equation for fluctuating winds is then derived. Some experimental evidence for the static loading is included. The analytical

A. E. Perry

1972-01-01

89

Development of a new generation of filament wound composite pressure cylinders  

Microsoft Academic Search

A new generation of composite pressure vessels for large scale market applications has been studied in this work. The vessels consist on a thermoplastic liner wrapped with a filament winding glass fibre reinforced polymer matrix structure. A high density polyethylene (HDPE) was selected as liner and a thermosetting resin used as matrix in the glass reinforced filament wound laminate.The Abaqus

J. C. Velosa; J. P. Nunes; P. J. Antunes; J. F. Silva; A. T. Marques

2009-01-01

90

ORIGIN OF THE DENSE CORE MASS FUNCTION IN CONTRACTING FILAMENTS  

SciTech Connect

Mass functions of starless dense cores (CMFs) may arise from contraction and dispersal of core-forming filaments. In an illustrative model, a filament contracts radially by self-gravity, increasing the mass of its cores. During this contraction, FUV photoevaporation and ablation by shocks and winds disperse filament gas and limit core growth. The stopping times of core growth are described by a waiting-time distribution. The initial filament column density profile and the resulting CMF each match recent Herschel observations in detail. Then low-mass cores have short growth ages and arise from the innermost filament gas, while massive cores have long growth ages and draw from more extended filament gas. The model fits the initial density profile and CMF best for mean core density 2 Multiplication-Sign 10{sup 4} cm{sup -3} and filament dispersal timescale 0.5 Myr. Then the typical core mass, radius, mean column density, and contraction speed are respectively 0.8 solar masses, 0.06 pc, 6 Multiplication-Sign 10{sup 21} cm{sup -2}, and 0.07 km s{sup -1}, also in accord with observed values.

Myers, Philip C., E-mail: pmyers@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-02-20

91

The Filament Feeding Mechanism  

Microsoft Academic Search

\\u000a Now that your Extruder is complete, it’s time to bolt it onto your 3D printer frame. Your 3D printer works by feeding a plastic\\u000a filament into the heater core of the Extruder. The plastic melts and is then forced through the Extruder’s nozzle and applied\\u000a to the worktable to print three dimensional objects.

Patrick Hood-Daniel; James Floyd Kelly

92

Protein machines and self assembly in muscle organization  

NASA Technical Reports Server (NTRS)

The remarkable order of striated muscle is the result of a complex series of protein interactions at different levels of organization. Within muscle, the thick filament and its major protein myosin are classical examples of functioning protein machines. Our understanding of the structure and assembly of thick filaments and their organization into the regular arrays of the A-band has recently been enhanced by the application of biochemical, genetic, and structural approaches. Detailed studies of the thick filament backbone have shown that the myosins are organized into a tubular structure. Additional protein machines and specific myosin rod sequences have been identified that play significant roles in thick filament structure, assembly, and organization. These include intrinsic filament components, cross-linking molecules of the M-band and constituents of the membrane-cytoskeleton system. Muscle organization is directed by the multistep actions of protein machines that take advantage of well-established self-assembly relationships. Copyright 1999 John Wiley & Sons, Inc.

Barral, J. M.; Epstein, H. F.

1999-01-01

93

Dynamic buckling of morphoelastic filaments.  

PubMed

The equilibrium shapes of biological structures as diverse as plant tendrils and bacterial filaments can be altered by externally imposed stresses of sufficient duration. We study the simplest model for this morphoelasticity--a filament whose intrinsic curvatures relax to the local curvatures--and illustrate its properties in the context of dynamic Euler buckling and writhing. When a thrust or twist is ramped in time the effective elastic properties of the filament depend on the load rate. Slow ramps interrupted by removal of the external forces can leave in equilibrium any of a whole continuum of buckled shapes. Morphoelastic relaxation can also allow a filament to bypass a bifurcation. PMID:16907052

Goldstein, Raymond E; Goriely, Alain

2006-07-01

94

Aeroelastic wind energy converter  

Microsoft Academic Search

The principle of aeroelastic wind energy conversion is introduced and an H-section model which works on the basis of torsional aeroelastic instability is described. A mathematical formulation for the prediction of the power coefficient of such wind machines is presented. A small model is constructed and tested in a wind tunnel. Although the efficiency of the model was very low,

G. Ahmadi

1978-01-01

95

Wind Power Now!  

ERIC Educational Resources Information Center

The government promotes and heavily subsidizes research in nuclear power plants. Federal development of wind power is slow in comparison even though much research with large wind-electric machines has already been conducted. Unless wind power programs are accelerated it will not become a major energy alternative to nuclear power. (MR)

Inglis, David Rittenhouse

1975-01-01

96

The Bearingless Electrical Machine  

NASA Technical Reports Server (NTRS)

Electromagnetic bearings allow the suspension of solids. For rotary applications, the most important physical effect is the force of a magnetic circuit to a high permeable armature, called the MAXWELL force. Contrary to the commonly used MAXWELL bearings, the bearingless electrical machine will take advantage of the reaction force of a conductor carrying a current in a magnetic field. This kind of force, called Lorentz force, generates the torque in direct current, asynchronous and synchronous machines. The magnetic field, which already exists in electrical machines and helps to build up the torque, can also be used for the suspension of the rotor. Besides the normal winding of the stator, a special winding was added, which generates forces for levitation. So a radial bearing, which is integrated directly in the active part of the machine, and the motor use the laminated core simultaneously. The winding was constructed for the levitating forces in a special way so that commercially available standard ac inverters for drives can be used. Besides wholly magnetic suspended machines, there is a wide range of applications for normal drives with ball bearings. Resonances of the rotor, especially critical speeds, can be damped actively.

Bichsel, J.

1992-01-01

97

A Review of Modern Wind Turbine Technology  

Microsoft Academic Search

This article deals with a review of modern wind turbine technology. Wind energy for electricity production today is a mature, competitive, and virtually pollution-free technology widely used in many areas of the world. Wind technology converts the energy available in wind to electricity or mechanical power through the use of wind turbines. A wind turbine is a machine for converting

M. Balat

2009-01-01

98

Design optimization of small wind turbines for low wind regimes  

Microsoft Academic Search

Attention is given to two examples illustrating the design optimization process for small wind turbines, which is concerned with machine parameters and the wind characteristics and electrical loads of the intended operating environment. The optimization process emphasizes the importance of rated wind speed, rotor rpm, generator size, and rotor blade characteristics. Wind turbines are noted to have been designed for

D. E. Cromack; Debbie Oscar

1984-01-01

99

Filament Eruptions, Jets, and Space Weather  

NASA Technical Reports Server (NTRS)

Previously, from chromospheric H alpha and coronal X-ray movies of the Sun's polar coronal holes, it was found that nearly all coronal jets (greater than 90%) are one or the other of two roughly equally common different kinds, different in how they erupt: standard jets and blowout jets (Yamauchi et al 2004, Apl, 605, 5ll: Moore et all 2010, Apj, 720, 757). Here, from inspection of SDO/AIA He II 304 A movies of 54 polar x-ray jets observed in Hinode/XRT movies, we report, as Moore et al (2010) anticipated, that (1) most standard x-ray jets (greater than 80%) show no ejected plasma that is cool enough (T is less than or approximately 10(exp 5K) to be seen in the He II 304 A movies; (2) nearly all blownout X-ray jets (greater than 90%) show obvious ejection of such cool plasma; (3) whereas when cool plasma is ejected in standard X-ray jets, it shows no lateral expansion, the cool plasma ejected in blowout X-ray jets shows strong lateral expansion; and (4) in many blowout X-ray jets, the cool plasma ejection displays the erupting-magnetic-rope form of clasic filament eruptions and is thereby seen to be a miniature filament eruption. The XRT movies also showed most blowout X-ray jets to be larger and brighter, and hence to apparently have more energy, than most standard X-ray jets. These observations (1) confirm the dichotomy of coronal jets, (2) agree with the Shibata model for standard jets, and (3) support the conclusion of Moore et al (2010) that in blowout jets the magnetic-arch base of the jet erupts in the manner of the much larger magnetic arcades in which the core field, the field rooted along the arcade's polarity inversion line, is sheared and twisted (sigmoid), often carries a cool-plasma filament, and erupts to blowout the arcade, producing a CME. From Hinode/SOT Ca II movies of the polar limb, Sterling et al (2010, ApJ, 714, L1) found that chromospheric Type-II spicules show a dichotomy of eruption dynamics similar to that found here for the cool-plasma component of coronal X-ray jets. This favors the idea that Type-II spicules are miniature counterparts of coronal X-ray jets. In Moore et al (2011, ApJ, 731, L18), we pointed out that if Type-II spicules are magnetic eruptions that work like coronal X-ray jets, they carry an area-averaged mechanical energy flux of approximately 7x10)(exp 5) erg cm(exp -2) s(exp-1) into the corona in the form of MHD waves and jet outflow, enough to power the heating of the global corona and solar wind. On this basis, from our observations of mini-filament eruptions in blowout X-ray jets, we infer that magnetic explosions of the type that have erupting filaments in them are the main engines of both (1) the steady solar wind and (2) the CMEs that produce the most severe space weather by blasting out through the corona and solar wind, making solar energetic particle storms, and bashing the Earth's magnetosphere. We conclude that in focusing on prominences and filament eruptions, Einar had his eye on the main bet for understanding what powers all space weather, both the extreme and the normal.

Moore, Ronald; Sterling, Alphonse; Robe, Nick; Falconer, David; Cirtain, Jonathan

2013-01-01

100

Quantification of Processing Effects on Filament Wound Pressure Vessels. Revision  

NASA Technical Reports Server (NTRS)

A computational simulation procedure is described which is designed specifically for the modeling and analysis of filament wound pressure vessels. Cylindrical vessels with spherical or elliptical end caps can be generated automatically. End caps other than spherical or elliptical may be modeled by varying circular sections along the x-axis according to the end cap shape. The finite element model generated is composed of plate type quadrilateral shell elements on the entire vessel surface. This computational procedure can also be used to generate grid, connectivity and material cards (bulk data) for component parts of a larger model. These bulk data are assigned to a user designated file for finite element structural/stress analysis of composite pressure vessels. The procedure accommodates filament wound pressure vessels of all types of shells-of -revolution. It has provisions to readily evaluate initial stresses due to pretension in the winding filaments and residual stresses due to cure temperature.

Aiello, Robert A.; Chamis, Christos C.

2002-01-01

101

Quantification of Processing Effects on Filament Wound Pressure Vessels  

NASA Technical Reports Server (NTRS)

A computational simulation procedure is described which is designed specifically for the modeling and analysis of filament wound pressure vessels. Cylindrical vessels with spherical or elliptical end caps can be generated automatically. End caps other than spherical or elliptical may be modeled by varying circular sections along the x-axis according to the C C! end cap shape. The finite element model generated is composed of plate type quadrilateral shell elements on the entire vessel surface. This computational procedure can also be sued to generate grid, connectivity and material cards (bulk data) for component parts of a larger model. These bulk data are assigned to a user designated file for finite element structural/stress analysis of composite pressure vessels. The procedure accommodates filament would pressure vessels of all types of shells-of-revolution. It has provisions to readily evaluate initial stresses due to pretension in the winding filaments and residual stresses due to cure temperature.

Aiello, Robert A.; Chamis, Christos C.

1999-01-01

102

Filament geometrical model and nozzle trajectory analysis in the fused deposition modeling process  

Microsoft Academic Search

The geometrical model of the filament during the fused deposition modeling (FDM) process was firstly proposed based on three\\u000a different models, tractrix, parabola, and catenary. Comparing with the actual measured filament curves on the Stratasys 1600\\u000a FDM machine, it is indicated that the tractrix model had the best agreement with the actual measured curves. With the analytical\\u000a simulation, the nozzle

Yu-zhen Jin; Jia-fan Zhang; Ying Wang; Zu-chao Zhu

2009-01-01

103

Intermediate Filaments: A Historical Perspective  

PubMed Central

Intracellular protein filaments intermediate in size between actin microfilaments and microtubules are composed of a surprising variety of tissue specific proteins commonly interconnected with other filamentous systems for mechanical stability and decorated by a variety of proteins that provide specialized functions. The sequence conservation of the coiled-coil, alpha-helical structure responsible for polymerization into individual 10 nm filaments defines the classification of intermediate filament proteins into a large gene family. Individual filaments further assemble into bundles and branched cytoskeletons visible in the light microscope. However, it is the diversity of the variable terminal domains that likely contributes most to different functions. The search for the functions of intermediate filament proteins has led to discoveries of roles in diseases of the skin, heart, muscle, liver, brain, adipose tissues and even premature aging. The diversity of uses of intermediate filaments as structural elements and scaffolds for organizing the distribution of decorating molecules contrasts with other cytoskeletal elements. This review is an attempt to provide some recollection of how such a diverse field emerged and changed over about 30 years. PMID:17493611

Oshima, Robert G.

2007-01-01

104

Centromeres of filamentous fungi  

PubMed Central

How centromeres are assembled and maintained remains one of the fundamental questions in cell biology. Over the past 20 years the idea of centromeres as precise genetic loci has been replaced by the realization that it is predominantly the protein complement that defines centromere localization and function. Thus, placement and maintenance of centromeres are excellent examples of epigenetic phenomena in the strict sense. In contrast, the highly derived “point centromeres” of the budding yeast Saccharomyces cerevisiae and its close relatives are counterexamples for this general principle of centromere maintenance. While we have learned much in the past decade, it remains unclear if mechanisms for epigenetic centromere placement and maintenance are shared amongst various groups of organisms. For that reason it seems prudent to examine species from many different phylogenetic groups with the aim to extract comparative information that will yield a more complete picture of cell division in all eukaryotes. This review addresses what has been learned by studying the centromeres of filamentous fungi, a large, heterogeneous group of organisms that includes important plant, animal and human pathogens, saprobes and symbionts that fulfill essential roles in the biosphere, as well as a growing number of taxa that have become indispensable for industrial use. PMID:22752455

Smith, Kristina M.; Galazka, Jonathan M.; Phatale, Pallavi A.; Connolly, Lanelle R.; Freitag, Michael

2012-01-01

105

Scanning Doppler Lidar Measurements for Wind Energy Applications  

Microsoft Academic Search

The development of wind energy has increased rapidly along with the size and capacity of wind turbines. These larger machines require detailed wind resource measurements at higher and higher altitudes. Accurate wind speed, wind direction, and turbulence statistics are required for wind resource assessment and efficient wind farm operation. Tower measurements are limited in coverage and do not provide the

R. Frehlich; N. Kelley

2008-01-01

106

Plasticity of Intermediate Filament Subunits  

E-print Network

Intermediate filaments (IFs) assembled in vitro from recombinantly expressed proteins have a diameter of 8–12 nm and can reach several micrometers in length. IFs assemble from a soluble pool of subunits, tetramers in the ...

Kirmse, Robert

107

A model of filament-wound thin cylinders  

NASA Technical Reports Server (NTRS)

A model was developed for simulating he manufacturing process of filament-wound cylinders made of a thermoset matrix composite. The model relates the process variables (winding speed, fiber tension, applied temperature) to the parameters characterizing the composite cylinder and the mandrel. The model is applicable to cylinders for which the diameter is large compared to the wall thickness. The model was implemented by a user-friendly computer code suitable for generating numerical results.

Calius, Emilio P.; Springer, George S.

1990-01-01

108

Analytical expressions for maximum wind turbine average power in a Rayleigh wind regime  

SciTech Connect

Average or expectation values for annual power of a wind turbine in a Rayleigh wind regime are calculated and plotted as a function of cut-out wind speed. This wind speed is expressed in multiples of the annual average wind speed at the turbine installation site. To provide a common basis for comparison of all real and imagined turbines, the Rayleigh-Betz wind machine is postulated. This machine is an ideal wind machine operating with the ideal Betz power coefficient of 0.593 in a Rayleigh probability wind regime. All other average annual powers are expressed in fractions of that power. Cases considered include: (1) an ideal machine with finite power and finite cutout speed, (2) real machines operating in variable speed mode at their maximum power coefficient, and (3) real machines operating at constant speed.

Carlin, P.W.

1996-12-01

109

A confined flare above filaments  

NASA Astrophysics Data System (ADS)

We present the dynamics of two filaments and a C-class flare observed in NOAA 11589 on 2012 October 16. We used the multi-wavelength high-resolution data from SDO, as well as THEMIS and ARIES ground-based observations. The observations show that the filaments are progressively converging towards each other without merging. We find that the filaments have opposite chirality which may have prevented them from merging. On October 16, a C3.3 class flare occurred without the eruption of the filaments. According to the standard solar flare model, after the reconnection, post-flare loops form below the erupting filaments whether the eruption fails or not. However, the observations show the formation of post-flare loops above the filaments, which is not consistent with the standard flare model. We analyze the topology of the active region's magnetic field by computing the quasi-separatrix layers (QSLs) using a linear force-free field extrapolation. We find a good agreement between the photospheric footprints of the QSLs and the flare ribbons. We discuss how slipping or slip-running reconnection at the QSLs may explain the observed dynamics.

Dalmasse, K.; Chandra, R.; Schmieder, B.; Aulanier, G.

2014-01-01

110

Galaxy filaments as pearl necklaces  

NASA Astrophysics Data System (ADS)

Context. Galaxies in the Universe form chains (filaments) that connect groups and clusters of galaxies. The filamentary network includes nearly half of the galaxies and is visually the most striking feature in cosmological maps. Aims: We study the distribution of galaxies along the filamentary network, trying to find specific patterns and regularities. Methods: Galaxy filaments are defined by the Bisous model, a marked point process with interactions. We use the two-point correlation function and the Rayleigh Z-squared statistic to study how galaxies and galaxy groups are distributed along the filaments. Results: We show that galaxies and groups are not uniformly distributed along filaments, but tend to form a regular pattern. The characteristic length of the pattern is around 7 h-1 Mpc. A slightly smaller characteristic length 4 h-1 Mpc can also be found, using the Z-squared statistic. Conclusions: We find that galaxy filaments in the Universe are like pearl necklaces, where the pearls are galaxy groups distributed more or less regularly along the filaments. We propose that this well-defined characteristic scale could be used to test various cosmological models and to probe environmental effects on the formation and evolution of galaxies. Appendices are available in electronic form at http://www.aanda.org

Tempel, E.; Kipper, R.; Saar, E.; Bussov, M.; Hektor, A.; Pelt, J.

2014-12-01

111

Minimal principle for rotor filaments  

PubMed Central

Three-dimensional rotors, or scroll waves, provide essential insight into the activity of excitable media. They also are a suspected cause in the formation and maintenance of ventricular fibrillation, whose lethality is well known. It is therefore of considerable interest to find out what configurations can be adopted by such pathologies. A scroll's behavior is embodied in its organizing center or filament, a largely quiescent tube about which the scroll rotates. Predicting filament shape has normally required computer-intensive simulations of the whole scroll in time. We have found a fast and robust principle that yields the prediction for stationary filaments on a purely geometrical basis, blind to the reaction parameters of the medium. The procedure is to calculate the filament shape as a minimal path. We work in singly diffusive media whose diffusivity tensor—and no other feature—varies spatially. Mathematical and numerical evidence is presented for the proposition that a stable filament is a geodesic in a three-dimensional space whose metric is given by the inverse diffusivity tensor of the medium. Away from the boundaries, a stable filament is unaffected by the reaction parameters. The algorithmic aspects of this work are subsidiary to our main purpose of drawing attention to the universal and unexpectedly exact fit of an elementary geodesic principle within reaction–diffusion theories. PMID:12048234

Wellner, Marcel; Berenfeld, Omer; Jalife, José; Pertsov, Arkady M.

2002-01-01

112

Improving the torque output in radial- and axial-flux permanent-magnet synchronous machines with concentrated windings by using a combined wye-delta connection  

Microsoft Academic Search

In this paper, a combined wye-delta connection is introduced and compared with a common wye-connection of a concentrated winding. Because the combined wye-delta connection has a higher fundamental winding factor, the output torque is higher for the same current density when a sinusoidal current is imposed. As the combined wye-delta connection has only a minor influence on the losses in

Hendrik Vansompel; Peter Sergeant; Luc Dupre; Alex Van den Bossche

2011-01-01

113

Kid Machine  

NSDL National Science Digital Library

This activity is on page 3 (continued on page 2) of the pdf, part of the Simple Machines Discovery Box. In this fun activity, learners "create" a complex machine by simulating the parts in action. Learners move their bodies and make sounds as if they are individual parts of a moving machine. Then learners discover what happens when part of a machine is broken and problem solve ways to fix it.

Omsi

2004-01-01

114

Quantum Machines  

E-print Network

We discuss quantum information processing machines. We start with single purpose machines that either redistribute quantum information or identify quantum states. We then move on to machines that can perform a number of functions, with the function they perform being determined by a program, which is itself a quantum state. Examples of both deterministic and probabilistic programmable machines are given, and we conclude with a discussion of the utility of quantum programs.

Mark Hillery; Vladimir Buzek

2009-03-24

115

Electron emitting filaments for electron discharge devices  

DOEpatents

Electrons are copiously emitted by a device comprising a loop-shaped filament made of lanthanum hexaboride. The filament is directly heated by an electrical current produced along the filament by a power supply connected to the terminal legs of the filament. To produce a filament, a diamond saw or the like is used to cut a slice from a bar made of lanthanum hexaboride. The diamond saw is then used to cut the slice into the shape of a loop which may be generally rectangular, U-shaped, hairpin-shaped, zigzag-shaped, or generally circular. The filaments provide high electron emission at a relatively low operating temperature, such as 1600.degree. C. To achieve uniform heating, the filament is formed with a cross section which is tapered between the opposite ends of the filament to compensate for non-uniform current distribution along the filament due to the emission of electrons from the filament.

Leung, Ka-Ngo (Hercules, CA); Pincosy, Philip A. (Oakland, CA); Ehlers, Kenneth W. (Alamo, CA)

1988-01-01

116

Mining machine  

Microsoft Academic Search

A haulage system for a mining machine comprises a mining machine mounted on and\\/or guided by a conveyor and reciprocable with respect thereto, the conveyor being provided with a rack having plural rows of teeth of identical pitch, with the teeth of one row staggered with respect to an adjacent row(s), and the machine being provided with at least one

Parrott

1985-01-01

117

Surface Heat Transfer in Electric Machines with Forced Air Flow  

Microsoft Academic Search

Since the insulation of windings in electric machines has comparatively low temperature limits, the problem of cooling these machines with the most economical use of material becomes one of major importance. The design of such machines from a temperature standpoint is usually based on tests of a previously made similar machine or else is of the ``cut arnd try'' type

G. E. Luke

1926-01-01

118

Doubly fed machine review: agenda. Conference report, Washington, DC  

SciTech Connect

The visual aids presented at the doubly fed machine review are presented. The doubly fed machine is a generating system either for wind turbines or hydro systems. Conceptual design and trade-offs are included, as well as testing. (LEW)

Not Available

1982-09-01

119

The Swedish Wind Energy Programme  

Microsoft Academic Search

Prospects and plans for wind energy development in Sweden are discussed. Most efforts will be devoted to developing large wind power units connected to the national grid. Most attention will be devoted to the horizontal-axis, propeller-type machine. Wind energy prospecting program will consist of a survey of winds in the 50-200 m height level. The Wind Power Experimental Unit will

S. Hugosson

1977-01-01

120

Actin filament dynamics using microfluidics.  

PubMed

We describe how combining microfluidics with TIRF and epifluorescence microscopy can greatly facilitate the quantitative analysis of actin assembly dynamics and its regulation, as well as the exploration of issues that were often out of reach with standard single-filament microscopy, such as the kinetics of processes linked to actin self-assembly or the kinetics of interaction with regulators. We also show how the viscous drag force exerted by fluid flowing on the filaments can be calibrated in order to assess the mechanosensitivity of end-binding protein machineries such as formins or adhesion proteins. We also discuss how microfluidics, in conjunction with other techniques, could be used to address the mechanism of coordination between heterogeneous populations of filaments, or the behavior of individual filaments during regulated treadmilling. These techniques also can be applied to study the assembly and regulation of other cytoskeletal polymers such as microtubules, septins, intermediate filaments, as well as the transport of cargoes by molecular motors under a flow-produced load. PMID:24630098

Carlier, Marie-France; Romet-Lemonne, Guillaume; Jégou, Antoine

2014-01-01

121

Droplets engulfing on a filament  

NASA Astrophysics Data System (ADS)

Two immiscible droplets wetting on a filament may assume engulfing, partial-engulfing, or non-engulfing morphology that depends on the wetting behavior and geometries of the resulting droplet-on-filament system. This paper studies the wetting behavior of two immiscible droplets contacting and sitting symmetrically on a straight filament. A set of ordinary differential equations (ODEs) is formulated for determining the wetting morphology of the droplet-on-filament system. In the limiting case of engulfing or non-engulfing, the morphology of the droplet-on-filament system is determined in explicit form. In the case of partial-engulfing, surface finite element method is further employed for determining the wetting morphology, surface energy, and internal pressures of droplets of the system. Numerical scaling study is performed to explore their dependencies upon the wetting properties and geometries of the system. The study can be applicable for analysis and design of textiles with tailorable wetting properties and development of novel multifunctional fibrous materials for environmental protection such as oil-spill sorption, etc.

Wu, Xiang-Fa; Yu, Meng; Zhou, Zhengping; Bedarkar, Amol; Zhao, Youhao

2014-03-01

122

Adjustable speed generators for wind turbines based on doubly-fed induction machines and 4-quadrant IGBT converters linked to the rotor  

Microsoft Academic Search

Wind turbines are being built at power levels above 1.5 MW. Higher power levels are being anticipated for offshore applications. To limit mechanical stresses and power surges in these high power systems, speed control is necessary. The doubly-fed induction generator (DFIG) system is investigated as a viable alternative to adjust speed over a wide range while keeping the cost of

S. Muller; M. Deicke; Rik W. De Doncker

2000-01-01

123

A wideband lumped circuit model of the terminal and internal electromagnetic response of rotating machine windings with a coaxial insulation system  

Microsoft Academic Search

The polyphase model can be used to simulate the terminal and internal electromagnetic response of, for example, Powerformer™: a new power generator. The circuit parameters are based on geometrical and material data. The slot leakage is modeled by means of a reluctance circuit, which is coupled to the electric circuit by means of winding templates. The capacitive current and its

Pär Holmberg; Mats Leijon; Stefan Johansson

2004-01-01

124

Predicting Noise From Wind Turbines  

NASA Technical Reports Server (NTRS)

Computer program WINDY predicts broadband noise spectra of horizontal-axis wind-turbine generators. Enables adequate assessment of impact of broadband wind-turbine noise. Effects of turbulence, trailing-edge wakes, and bluntness taken into account. Program has practical application in design and siting of wind-turbine machines acceptable to community. Written in GW-Basic.

Grosveld, Ferdinand W.

1990-01-01

125

The circulation dynamics associated with a northern Benguela upwelling filament during October 2010  

NASA Astrophysics Data System (ADS)

Upwelling filaments, a common feature in all the major upwelling systems, are also regularly observed in the Benguela upwelling system and are thought to provide an effective mechanism for the exchange of matter between the shelf and the open ocean. The mesoscale dynamics of a northern Benguela upwelling filament located at approximately 18.5°S were examined and the associated transport was quantified. The development of the filament was tracked using optimal interpolated SST satellite data and two transects were consequently sampled across the feature using a towed undulating CTD (ScanFish). Additional hydrographic, nutrient and biological parameters were investigated at several stations along each transect. Following 7 days of strong upwelling favorable winds, sampling coincided with a period of relative wind relaxation and the filament was presumably in a decaying state. The basic mesoscale structure of the investigated filament corresponded well to what had previously been described for filaments from other eastern boundary current systems. The cross-shore transport associated with the filament was found to be significantly greater than the integrated Ekman transport in the region. With the combination of the high resolution dataset and a MOM-4 ecosystem model the complex mesoscale flow field associated with the feature could be observed and the counterbalancing onshore transport, associated with subsurface dipole eddies, was revealed within the filament. The results further suggest that an interaction between the offshore bending of flow at the Angola-Benguela Front (ABF), the detachment of the strong poleward flow from the coast as the thermal front meanders and the observed dipole eddies may be driving filament occurrence in the region off Cape Frio.

Muller, Annethea A.; Mohrholz, Volker; Schmidt, Martin

2013-07-01

126

Kicking Machine  

NSDL National Science Digital Library

In this design challenge activity, learners build a machine that kicks a Ping-Pong ball into a cup lying on its side 12 inches away. Learners use a pendulum, a rubber band, or a combination of the two to do this and test the accuracy of their machines by shooting a Ping-Pong ball into a cup. Educators can use this activity to demonstrate simple machines and kinetic/potential energy. This activity can be followed up with "Extreme Kicking Machine" which adds an even greater challenge into the mix.

Wgbh

2010-01-01

127

Development of Nylon Based FDM Filament for Rapid Tooling Application  

NASA Astrophysics Data System (ADS)

There has been critical need for development of cost effective nylon based wire to be used as feed stock filament for fused deposition modelling (FDM) machine. But hitherto, very less work has been reported for development of alternate solution of acrylonitrile butadiene styrene (ABS) based wire which is presently used in most of FDM machines. The present research work is focused on development of nylon based wire as an alternative of ABS wire (which is to be used as feedstock filament on FDM) without changing any hardware or software of machine. For the present study aluminium oxide (Al2O3) as additive in different proportion has been used with nylon fibre. Single screw extruder was used for wire preparation and wire thus produced was tested on FDM. Mechanical properties i.e. tensile strength and percentage elongation of finally developed wire have been optimized by Taguchi L9 technique. The work represented major development in reducing cost and time in rapid tooling applications.

Singh, R.; Singh, S.

2014-04-01

128

: Helmholtz machine estimation .  

E-print Network

: Helmholtz machine density estimation . . : . . . (supervised learning) , (active learning) (query learning) [1, 3]. . (unsupervised learning), . , [5]. . Helmholtz machine , . Helmholtz machine : Helmholtz machine [2] . Helmholtz machine (generative network) (recognition network) . , , . Helmholtz machine (self

129

Absence of spermine in filamentous fungi.  

PubMed Central

Polyamines were examined in several yeasts and filamentous fungi. Whereas putrescine, spermidine, and spermine were present in the yeasts, spermine was not detected in any of the filamentous fungi. PMID:830639

Nickerson, K W; Dunkle, L D; Van Etten, J L

1977-01-01

130

Studies on the dynamics of limited filaments  

E-print Network

A study on the dynamics of filaments in the presence of a diagnostic, conductive limiter is presented. Plasma filaments are coherent structures present in many fusion devices and transport a significant amount of particles ...

Bonde, Jeffrey David

2010-01-01

131

One Half Million Mile Solar Filament  

NASA Video Gallery

NASAâ??s Solar Dynamics Observatory (SDO) captures a very long, whip-like solar filament extending over half a million miles in a long arc above the sunâ??s surface. Filaments are cooler clouds of ...

132

SDO Watches Giant Filament on the Sun  

NASA Video Gallery

A snaking, extended filament of solar material currently lies on the front of the sun-- some 1 million miles across from end to end. Filaments are clouds of solar material suspended above the sun b...

133

Allelopathy of filamentous green algae  

Microsoft Academic Search

Allelopathy of filamentous green algae (FGA) has been less studied than that of macrophytes. Little Budworth Pool, Cheshire, UK is a small, shallow, clear-water lake with high TP concentrations, very high NO3-N concentrations, only moderate phytoplankton density, high FGA growth (mainly Spirogyra sp.) and no submerged plants. Experiments were carried out to test the possible allelopathic effects of Spirogyra on

Brian Moss

2005-01-01

134

Filament depolymerisation by motor proteins  

NASA Astrophysics Data System (ADS)

Many active processes in cells are driven by highly specialized motor proteins, which interact with filaments of the cytoskeleton. Members of the Kin-13 kinesin subfamily are able to interact specifically with filament ends and induce depolymerisation of the filaments ends. Recent in vitro assays and single molecule studies have shown, that MCAK accumulates at both ends of stabilized microtubules and induces depolymerisation while at the same time MCAK molecules do not generate directed motion along the microtubules [1]. We analyse both, a stochastic model and a generic mean-field description of this process. We discuss conditions under which motors dynamically accumulate at the filament end. Such a dynamic accumulation occurs for processive cutting, which implies, that the motor can remain attached to the shrinking edge after subunit removal. For processive cutting, the depolymerisation speed as a function of the bulk motor concentration can exhibit a maximum for intermediate motor concentration. For high motor processivity a dynamic instability can occur. We discuss our results in relation to recent experiments on Kin-13 motor proteins [2]. [1] A.W. Hunter, et al., Mol. Cell 11, 445 (2003) [2] G.Klein, et al., submitted

Klein, Gernot

2005-03-01

135

Nonplanar machines  

SciTech Connect

This talk examines methods available to minimize, but never entirely eliminate, degradation of machine performance caused by terrain following. Breaking of planar machine symmetry for engineering convenience and/or monetary savings must be balanced against small performance degradation, and can only be decided on a case-by-case basis. 5 refs.

Ritson, D. (Stanford Linear Accelerator Center, Menlo Park, CA (USA))

1989-05-01

136

Electric machine  

DOEpatents

An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.

El-Refaie, Ayman Mohamed Fawzi (Niskayuna, NY); Reddy, Patel Bhageerath (Madison, WI)

2012-07-17

137

Simple Machines  

NSDL National Science Digital Library

How do you get a glove and a ball up to your tree house? One answer is to use a pulley. A pulley is a simple machine. In this original KET interactive, children learn about the basic workings of three simple machines.

Ket

2010-11-16

138

Excavating machines  

SciTech Connect

The excavating machine has a cutter carrying boom carried by a boom support member which can be swung about an axis extending in the direction of the roadway. The machine includes a cutter unit and a stay unit each of which is releasably anchorable in the roadway and each of which can be advanced relative to the other unit.

Plummer, D.

1980-10-21

139

ACTIN FILAMENT DESTRUCTION BY OSMIUM TETROXIDE  

Microsoft Academic Search

We have studied the destruction of purified muscle actin filaments by osmium tetroxide (OsO4) to develop methods to preserve actin filaments during prepara- tion for electron microscopy. Actin filaments are fragmented during exposure to OsO4. This causes the viscosity of solutions of actin filaments to decrease, ultimately to zero, and provides a convenient quantitative assay to analyze the reaction. The

PAMELA MAUPIN-SZAMIER; THOMAS D. POLLARD

2010-01-01

140

Power factor correction of an electrical drive system based on multiphase machines  

E-print Network

Power factor correction of an electrical drive system based on multiphase machines Khoudir MAROUANI on multiphase machines. Thus, the double-star induction machine is taken, as an example of multiphase machines is to maintain the PF of the power-winding, of the double star induction machine, in vicinity of unity whatever

Paris-Sud XI, Université de

141

Actin Filament Segmentation Using Dynamic Programming  

E-print Network

Actin Filament Segmentation Using Dynamic Programming Hongsheng Li, Tian Shen, and Xiaolei Huang for actin filament segmen- tation in 2D TIRFM image sequences. This problem is difficult because actin candidate tip locations, actin filaments' body points are inferred by a dynamic programming method, which

Huang, Xiaolei

142

The Length of the Filamentous Pseudomonas aeruginosa  

Microsoft Academic Search

SUMMARY The length of the Pseudomonas aeruginosa filamentous bacteriophage Pf was found to be 1915 +77 nm, as measured in the electron microscope using the Kleinschmidt spreading technique. Pf is thus the longest filamentous phage so far isolated. Coliphage If, the I-specific filamentous phage, is nearest to it with a length of I3OO nm. Bacteriophage Pf, which is the only

Bacteriophage Pf

1973-01-01

143

Diamond film by hot filament CVD method  

NASA Technical Reports Server (NTRS)

Diamond synthesis by the hot filament CVD method is discussed. A hot filament decomposes gas mixtures and oxygen containing organic compounds such as alcohols. which are carbon sources. The resulting thin films, growth mechanisms, and characteristics and problems associated with the hot filament CVD method are analyzed and evaluated.

Hirose, Y.

1988-01-01

144

The M-band: an elastic web that crosslinks thick filaments in the center of the sarcomere  

Microsoft Academic Search

The sarcomere of striated muscle is an efficient molecular machine, characterized by perfect structural organization of contractile filaments. This order is ensured by the sarcomere cytoskeleton, an important element of which is the M-band, believed to maintain the thick filament lattice. We review here recent progress in understanding the M-band function and its structural organization. We explain how the M-band

Irina Agarkova; Jean-Claude Perriard

2005-01-01

145

Development status of superconducting rotating machines  

Microsoft Academic Search

Advances in high temperature superconductors (HTS) are enabling a new class of synchronous rotating machines (supermotors and supergenerators) that can generically be categorized as supermachines. Compared to conventional machines of equivalent rating, these supermachines are expected to be less expensive, lighter, more compact, efficient, and provide significantly superior stable operation in a power system. The field windings are made with

S. S. Kalsi

2002-01-01

146

Numerical simulation of vortex breakdown by the vortex-filament method  

NASA Technical Reports Server (NTRS)

The vortex filament method was applied to the simulation of vortex breakdown. The principal vortex region was represented by multiple filaments, and an axial velocity component was induced by a spiral winding of the filaments. First, an accuracy check was performed for a cylindrical swirling flow with simple analytical expressions for the axial and theta velocities. The result suggests that the flow field is simulated to any accuracy by increasing the number of filaments. Second, an axisymmetric type vortex breakdown was simulated, with experimental data serving as upstream conditions. The calculated axial and theta velocity contours show the breakdown of the vortex, including a rapid change in the vortex core, followed axially by a recovery zone and then a second breakdown. When three dimensional initial data are used the second breakdown appears to be of the spiral type in correspondence with experimental observations. The present method is easily used to simulate other types of vortex breakdown or other vortex flows with axial velocity.

Nakamura, Y.; Leonard, A.; Spalart, P. R.

1983-01-01

147

Scribbling Machines  

NSDL National Science Digital Library

In this activity, learners explore electronics and motion by making a Scribbling Machine, a motorized contraption that moves in unusual ways and leaves a mark to trace its path. Itâs made from simple materials and is based on the idea of motion created by an offset motor. Try using harvested motors and switches from discarded toys and electronics to make your Scribbling Machine - this not only keeps costs down, but is a playful and inventive way to explore how everyday objects work. To take the activity further, you can also incorporate PicoCrickets to make your Scribbling Machine more intelligent and to explore computers.

Exploratorium

2013-01-30

148

Testing of the Pole Face Winding crimpings Measurements carried out on the 100 PS main units before start up of the PS machine in 2007  

E-print Network

The crimpings of the Pole Face Windings (PFW), used to connect the rectangular copper conductor of the main windings with its supply cable, could have defects due to the manufacture process. They could lead to an extensive high electrical resistance. To locate these defects, the PFW are powered with 80 Ampere DC and the voltage drop over the electrical resistances of the crimping is measured. The measurements are done between the PFW current leads and the corresponding pick-up. By subtracting the resistance of the supply cable and the interconnection cable the crimping resistance is calculated. During the long shutdown 2005 and the annual shutdown 2006/2007 a total of 34 main units, and their PFWs, have been refurbished [1]. The refurbished main units are equipped with new PFW. On this PFW the crimping technique was improved and the defect of high crimping contact resistance should not appear. Nevertheless to have complete picture of the situation the 34 refurbished main units and the 66 none refurbished unit...

Hans, O

2007-01-01

149

On the equilibrium of rotating filaments  

E-print Network

The physical properties of the so-called Ostriker isothermal, non-rotating filament have been classically used as benchmark to interpret the stability of the filaments observed in nearby clouds. However, such static picture seems to contrast with the more dynamical state observed in different filaments. In order to explore the physical conditions of filaments under realistic conditions, in this work we theoretically investigate how the equilibrium structure of a filament changes in a rotating configuration. To do so, we solve the hydrostatic equilibrium equation assuming both uniform and differential rotations independently. We obtain a new set of equilibrium solutions for rotating and pressure truncated filaments. These new equilibrium solutions are found to present both radial and projected column density profiles shallower than their Ostriker-like counterparts. Moreover, and for rotational periods similar to those found in the observations, the centrifugal forces present in these filaments are also able to...

Recchi, S; Palestini, A

2014-01-01

150

PARTIAL SLINGSHOT RECONNECTION BETWEEN TWO FILAMENTS  

SciTech Connect

We present a rare observation of an interaction between two filaments around AR 11358 and AR 11361 on 2011 December 3 that is strongly suggestive of the occurrence of slingshot reconnection. A small elbow-shaped active-region filament (F12) underwent a failed eruption that brought it into contact with a nearby larger, thicker filament (F34). Accompanied by the appearance of complicated internal structures below the erupting F12, its two legs separated away from each other and then connected into F34. This process led the filaments to change their connectivity to form two newly linked filaments, and one of them showed a clear inverse {gamma}-shape. However, the alteration in the filament connectivity was imperfect since F34 is discernible after the eruption. These observations can be interpreted as a partial slingshot reconnection between two filaments that had unequal axial magnetic flux.

Jiang, Yunchun; Hong, Junchao; Yang, Jiayan; Bi, Yi; Zheng, Ruisheng; Yang, Bo; Li, Haidong; Yang, Dan, E-mail: jyc@ynao.ac.cn [National Astronomical Observatory/Yunnan Astronomical Observatory, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China)] [National Astronomical Observatory/Yunnan Astronomical Observatory, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China)

2013-02-10

151

UNUSUAL FILAMENTS INSIDE THE UMBRA  

SciTech Connect

We analyze several unusual filamentary structures which appeared in the umbra of one of the sunspots in AR 11302. They do not resemble typical light bridges in morphology or in evolution. We analyze data from SDO/HMI to investigate their temporal evolution, Hinode/SP for photospheric inversions, IBIS for chromospheric imaging, and SDO/AIA for the overlying corona. Photospheric inversions reveal a horizontal, inverse Evershed flow along these structures, which we call umbral filaments. Chromospheric images show brightenings and energy dissipation, while coronal images indicate that bright coronal loops seem to end in these umbral filaments. These rapidly evolving features do not seem to be common, and are possibly related to the high flare-productivity of the active region. Their analysis could help to understand the complex evolution of active regions.

Kleint, L. [High Altitude Observatory/NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); Sainz Dalda, A., E-mail: kleintl@ucar.edu [Stanford-Lockheed Institute for Space Research, Stanford University, HEPL, 466 Via Ortega, Stanford, CA 94305 (United States)

2013-06-10

152

Machine therapy  

E-print Network

Machine Therapy is a new practice combining art, design, psychoanalysis, and engineering work in ways that access and reveal the vital, though often unnoticed, relevance of people's interactions and relationships with ...

Dobson, Kelly E. (Kelly Elizabeth), 1970-

2007-01-01

153

Math Machines  

NSDL National Science Digital Library

The mission of the Math Machines organization is to "improve the quality of mathematical education, enhance the transfer of mathematical thinking into other classes, and increase students' ability to apply rigorous mathematics outside the classroom." Their website supports a National Science Foundation ATE grant-supported project designed to improve teaching in the areas of Mathematics, Science, and Technology at the high school and college levels. This improved learning results from using math, science, and technology principles to build and control various machines such as pointers and robots or "math machines", which are simple devices that provide an immediate, physical, dynamic expression to abstract mathematical equations. The website provides information links on Educational Theory, Classroom Activities, Project Workshops, Calculators & Programs, and Machine Construction Instructions for Building: Closed Circuits, Servo Motors, Controllers, Robot Boards and more. There is also contact information, an FAQ section, as well as upcoming events.

2010-05-18

154

Mechanics of vimentin intermediate filaments  

NASA Technical Reports Server (NTRS)

It is increasingly evident that the cytoskeleton of living cells plays important roles in mechanical and biological functions of the cells. Here we focus on the contribution of intermediate filaments (IFs) to the mechanical behaviors of living cells. Vimentin, a major structural component of IFs in many cell types, is shown to play an important role in vital mechanical and biological functions such as cell contractility, migration, stiffness, stiffening, and proliferation.

Wang, Ning; Stamenovic, Dimitrijie

2002-01-01

155

Filament wound rocket motor chambers  

NASA Technical Reports Server (NTRS)

The design, analysis, fabrication and testing of a Kevlar-49/HBRF-55A filament wound chamber is reported. The chamber was fabricated and successfully tested to 80% of the design burst pressure. Results of the data reduction and analysis from the hydrotest indicate that the chamber design and fabrication techniques used for the chamber were adequate and the chamber should perform adequately in a static test.

1976-01-01

156

Monel Machining  

NASA Technical Reports Server (NTRS)

Castle Industries, Inc. is a small machine shop manufacturing replacement plumbing repair parts, such as faucet, tub and ballcock seats. Therese Castley, president of Castle decided to introduce Monel because it offered a chance to improve competitiveness and expand the product line. Before expanding, Castley sought NERAC assistance on Monel technology. NERAC (New England Research Application Center) provided an information package which proved very helpful. The NASA database was included in NERAC's search and yielded a wealth of information on machining Monel.

1983-01-01

157

Rotating electric machine with fluid supported parts  

DOEpatents

A rotating electric machine in which the armature winding thereof and other parts are supported by a liquid to withstand the mechanical stresses applied during transient overloads and the like. In particular, a narrow gap is provided between the armature winding and the stator which supports it and this gap is filled with an externally pressurized viscous liquid. The liquid is externally pressurized sufficiently to balance the static loads on the armature winding. Transient mechanical loads which deform the armature winding alter the gap dimensions and thereby additionally pressurize the viscous liquid to oppose the armature winding deformation and more nearly uniformly to distribute the resulting mechanical stresses.

Smith, Jr., Joseph L. (Concord, MA); Kirtley, Jr., James L. (Brookline, MA)

1981-01-01

158

Comparative study of the behavior of wind-turbines in a wind farm  

Microsoft Academic Search

The Sotavento wind farm is an experimental wind farm which has different types of wind turbines. It is located in an area whose topography is moderately complex, and where wake effects can be significant. One of the objectives of Sotavento wind farm is to compare the performances of the different machines; particularly regarding power production, maintenance and failures. However, because

Emilio Migoya; Antonio Crespo; Javier García; Fermín Moreno; Fernando Manuel; Ángel Jiménez; Alexandre Costa

2007-01-01

159

Generalization of Filament Braiding Model for Amyloid Fibril Assembly  

NASA Astrophysics Data System (ADS)

Research into the formation of amyloid fibrils is motivated by their association with several prominent diseases, among these Alzheimer's Disease, Parkinson's Disease and amyloidosis. Previous work in monitering the aggregation of immunoglobulin light chains to form amyloid fibrils suggests a braided structure where filaments and protofibrils wind together to form Type I and Type II fibrils. Non-contact atomic force microscopy is used to image and explore the kinetics of several other amyloid fibril forming proteins in an effort to generalize the filament braiding model. Included in this study are insulin and the B1 domain of G. Both of these have been shown to form fibrils in vitro. Alpha-synuclein is also included in this study. It is involved in the formation of Lewy bodies in Parkinson's Disease. The fourth protein used in this comparitive study is human amylin that is the cause of a systemic amyloidosis. Results from these four proteins and their associated fibrils are compared to the Ig light chain fibril structure in an effort to show the universality of the filament braiding model.

Pope, Maighdlin; Ionescu-Zanetti, Cristian; Khurana, Ritu; Carter, Sue

2001-03-01

160

Wind resource assessment in California. Contractor report (final)  

Microsoft Academic Search

The report provides a strategy for wind-energy prospecting, a design for a wind prospecting instrument, and a method of analysis of wind-energy data. The formulation also produces an improved basis for the calculation of wind machine performance using only a few wind parameter measurements.

1980-01-01

161

Femtosecond Laser Filamentation for Atmospheric Sensing  

PubMed Central

Powerful femtosecond laser pulses propagating in transparent materials result in the formation of self-guided structures called filaments. Such filamentation in air can be controlled to occur at a distance as far as a few kilometers, making it ideally suited for remote sensing of pollutants in the atmosphere. On the one hand, the high intensity inside the filaments can induce the fragmentation of all matters in the path of filaments, resulting in the emission of characteristic fluorescence spectra (fingerprints) from the excited fragments, which can be used for the identification of various substances including chemical and biological species. On the other hand, along with the femtosecond laser filamentation, white-light supercontinuum emission in the infrared to UV range is generated, which can be used as an ideal light source for absorption Lidar. In this paper, we present an overview of recent progress concerning remote sensing of the atmosphere using femtosecond laser filamentation. PMID:22346566

Xu, Huai Liang; Chin, See Leang

2011-01-01

162

Workout Machine  

NASA Technical Reports Server (NTRS)

The Orbotron is a tri-axle exercise machine patterned after a NASA training simulator for astronaut orientation in the microgravity of space. It has three orbiting rings corresponding to roll, pitch and yaw. The user is in the middle of the inner ring with the stomach remaining in the center of all axes, eliminating dizziness. Human power starts the rings spinning, unlike the NASA air-powered system. Marketed by Fantasy Factory (formerly Orbotron, Inc.), the machine can improve aerobic capacity, strength and endurance in five to seven minute workouts.

1995-01-01

163

Culture Machine  

NSDL National Science Digital Library

Culture Machine is a new, refereed, electronic journal encompassing cultural studies and cultural theory. The international editorial board of the interactive journal aims to "generat[e] research in culture and theory" by promoting and publishing "the most provocative of new work." The theme of the inaugural issue is Taking Risks with the Future. Content includes articles such as Life After Death of the Text by Johan Fornas, Cultural Studies in the Clouds: Mourning for Detail by Tadeusz Slawek, and The Future States of Politics by Kenneth Surin. Culture Machine is hosted by the University of Teesside, England.

164

Intermediate Filaments as Signaling Platforms  

NSDL National Science Digital Library

Intermediate filaments (IFs) are cytoskeletal structures that are crucial for maintaining the structural and mechanical integrity of cells and tissues. Intriguingly, a wide range of previously unknown nonmechanical roles for the IF cytoskeleton are emerging: Recent studies have linked IFs to the integration of signals related to the determination of cell size, the regulation of cell migration and cell survival, and the buffering of the effects of stress-activated kinases. The characteristic structural features and expression patterns of the different members of this diverse family of highly abundant proteins make them well suited to act as cell- and tissue-specific modifiers and organizers of signaling.

Hanna-Mari Pallari (University of Turku and Abo Akademi University;Turku Centre for Biotechnology REV); John E. Eriksson (University of Turku and Abo Akademi University;Turku Centre for Biotechnology REV)

2006-12-19

165

On arch-filament systems in spotgroups  

Microsoft Academic Search

Systems of arch-shaped filaments (AFS) occurring in the interspot region of young bipolar groups are studied. Their main characteristics are: Average length: 30000km, average width 20000km, width of individual filaments 1000–3000 km, height of arches 4–15000 km. A typical lifetime of the filaments 30 min; appreciable changes of the system occur within several hours; the lifetime of a system is

A. Bruzek

1967-01-01

166

Magnetic field generated by current filaments  

NASA Astrophysics Data System (ADS)

We investigate the magnetic field generated by two straight current filaments using the analogy between steady MHD and Euler flows. Using the Biot-Savart law, we present a dynamical system describing the extension of magnetic lines around the current filaments. It is demonstrated that, if two current filaments are non-parallel, a magnetic line starting near one current goes to infinity by the drifting effect of the other.

Kimura, Y.

2014-10-01

167

Wind Energy Conversion Using a Self-Excited Induction Generator  

Microsoft Academic Search

A wind energy conversion scheme using an induction machine driven by a variable speed wind turbine is described. Excitation control has been obtained by employing a single value capacitor and thyristor controlled inductor. Wind speed cube law is proposed to be followed in loading the induction machine for maximising energy conversion. Performance characteristics of the generation scheme have been evaluated

G. Raina; O. P. Malik

1983-01-01

168

An Unusual System of HI Filaments near WR 5 and HD 17603  

E-print Network

We report the discovery of a system of unusual HI filaments which appear to be associated with molecular clouds in the Perseus spiral arm of our Galaxy. We investigate the hypothesis that this system is the result of a directed flow of dissociated gas from clouds trapped within an extended wind flow from massive stars. The Wolf-Rayet star WR 5 and the OIb(f) star HD 17603 are identified as candidate driving sources. However, an examination of this hypothesis within the context of the theory of mass-loaded winds shows that these two stars alone cannot account for the energetics and kinematics of the required spherically symmetric wind flow. Unless the apparent association between HI, molecular gas, and stars is an accidental one, we suggest that other as-yet unidentified stars must have contributed to driving the filaments.

Lewis B. G. Knee; Bradley J. Wallace; Magdalen Normandeau

2005-05-18

169

Methods for modeling cytoskeletal and DNA filaments  

NASA Astrophysics Data System (ADS)

This review summarizes the models that researchers use to represent the conformations and dynamics of cytoskeletal and DNA filaments. It focuses on models that address individual filaments in continuous space. Conformation models include the freely jointed, Gaussian, angle-biased chain (ABC), and wormlike chain (WLC) models, of which the first three bend at discrete joints and the last bends continuously. Predictions from the WLC model generally agree well with experiment. Dynamics models include the Rouse, Zimm, stiff rod, dynamic WLC, and reptation models, of which the first four apply to isolated filaments and the last to entangled filaments. Experiments show that the dynamic WLC and reptation models are most accurate. They also show that biological filaments typically experience strong hydrodynamic coupling and/or constrained motion. Computer simulation methods that address filament dynamics typically compute filament segment velocities from local forces using the Langevin equation and then integrate these velocities with explicit or implicit methods; the former are more versatile and the latter are more efficient. Much remains to be discovered in biological filament modeling. In particular, filament dynamics in living cells are not well understood, and current computational methods are too slow and not sufficiently versatile. Although primarily a review, this paper also presents new statistical calculations for the ABC and WLC models. Additionally, it corrects several discrepancies in the literature about bending and torsional persistence length definitions, and their relations to flexural and torsional rigidities.

Andrews, Steven S.

2014-02-01

170

On the equilibrium of rotating filaments  

NASA Astrophysics Data System (ADS)

The physical properties of the so-called Ostriker isothermal, non-rotating filament have been classically used as benchmark to interpret the stability of the filaments observed in nearby clouds. However, such static picture seems to contrast with the more dynamical state observed in different filaments. In order to explore the physical conditions of filaments under realistic conditions, in this work we theoretically investigate how the equilibrium structure of a filament changes in a rotating configuration. To do so, we solve the hydrostatic equilibrium equation assuming both uniform and differential rotations independently. We obtain a new set of equilibrium solutions for rotating and pressure truncated filaments. These new equilibrium solutions are found to present both radial and projected column density profiles shallower than their Ostriker-like counterparts. Moreover, and for rotational periods similar to those found in the observations, the centrifugal forces present in these filaments are also able to sustain large amounts of mass (larger than the mass attained by the Ostriker filament) without being necessary unstable. Our results indicate that further analysis on the physical state of star-forming filaments should take into account rotational effects as stabilizing agents against gravity.

Recchi, S.; Hacar, A.; Palestini, A.

2014-10-01

171

Myosin filament structure in vertebrate smooth muscle  

PubMed Central

The in vivo structure of the myosin filaments in vertebrate smooth muscle is unknown. Evidence from purified smooth muscle myosin and from some studies of intact smooth muscle suggests that they may have a nonhelical, side-polar arrangement of crossbridges. However, the bipolar, helical structure characteristic of myosin filaments in striated muscle has not been disproved for smooth muscle. We have used EM to investigate this question in a functionally diverse group of smooth muscles (from the vascular, gastrointestinal, reproductive, and visual systems) from mammalian, amphibian, and avian species. Intact muscle under physiological conditions, rapidly frozen and then freeze substituted, shows many myosin filaments with a square backbone in transverse profile. Transverse sections of fixed, chemically skinned muscles also show square backbones and, in addition, reveal projections (crossbridges) on only two opposite sides of the square. Filaments gently isolated from skinned smooth muscles and observed by negative staining show crossbridges with a 14.5-nm repeat projecting in opposite directions on opposite sides of the filament. Such filaments subjected to low ionic strength conditions show bare filament ends and an antiparallel arrangement of myosin tails along the length of the filament. All of these observations are consistent with a side-polar structure and argue against a bipolar, helical crossbridge arrangement. We conclude that myosin filaments in all smooth muscles, regardless of function, are likely to be side-polar. Such a structure could be an important factor in the ability of smooth muscles to contract by large amounts. PMID:8698822

1996-01-01

172

Measurement of birefringence inside a filament  

SciTech Connect

We quantified the ultrafast birefringence induced in the filament in an atomic gas by measuring the filament-induced polarization rotation of a probe pulse. Based on the dephasing of the probe's orthogonal polarization components in argon, the experiment was done at 1 atm by copropagating a linearly polarized 400-nm probe pulse with an 800-nm pump pulse which generated the filament. The probe's elliptical polarization states were shown under various initial pump-probe polarization schemes. These states were verified by comparing the filament-induced probe polarization rotation angle and the ellipticity of the probe polarization.

Yuan Shuai [Centre d'Optique, Photonique et Laser (COPL) et Departement de physique, de genie physique et d'optique, Universite Laval, Quebec, Quebec G1V 0A6 (Canada); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Wang, Tie-Jun; Chin, See Leang [Centre d'Optique, Photonique et Laser (COPL) et Departement de physique, de genie physique et d'optique, Universite Laval, Quebec, Quebec G1V 0A6 (Canada); Kosareva, Olga; Panov, Nikolay; Makarov, Vladimir [International Laser Center and Faculty of Physics, Lomonosov Moscow State University, Moscow (Russian Federation); Zeng Heping [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China)

2011-07-15

173

Simulating Turing Machines on Maurer Machines  

E-print Network

Simulating Turing Machines on Maurer Machines J.A. Bergstra1,2 and C.A. Middelburg3 1 Programming MB Eindhoven, the Netherlands keesm@win.tue.nl Abstract. Maurer machines are much closer to real computers than Turing machines. Computer instructions play a prominent part in Mau- rer machines. We show

van der Zwaag, Mark

174

Decoding Machine  

NSDL National Science Digital Library

In this math lesson, learners explore variables and their uses. Learners pretend to be FBI agents and make a TOP SECRET tool that enables them to decode and find the values of hidden messages and words. Learners make their simple "decoding machines" out of paper and tape.

Lessonplans, Utah

2012-10-22

175

Leonardo's Machines  

NSDL National Science Digital Library

This Science NetLinks lesson will highlight some of Leonardo da Vinci's futuristic inventions, introducing the elements of machines. Through the use of student interactives, this lesson provides an interesting context in which students can begin to develop their ideas about the uniqueness of humans in the natural world.

Science Netlinks;

2003-03-05

176

Function Machine  

NSDL National Science Digital Library

This Java applet allows learners to explore simple linear functions. Students determine the algebraic form of a linear equation by entering inputs into the machine and by looking for patterns in the outputs. The function rules available are: integers from -10 to 10 are either added to, subtracted from, or multiplied by the input x to yield the output y.

2011-01-01

177

The WSRT virgo filament survey  

E-print Network

In the last few years the realization has emerged that the universal baryons are almost equally distributed by mass in three components: (1) galactic concentrations, (2) a warm-hot intergalactic medium (WHIM) and (3) a diffuse intergalactic medium. These three components are predicted by hydrodynamical simulations and are probed by QSO absorption lines. To observe the WHIM in neutral hydrogen, observations are needed which are deeper than log(N$_{HI}$)=18. The WHIM should appear as a Cosmic Web, underlying the galaxies with higher column densities. We have used the WSRT, to simulate a filled aperture by observing at very high hour angles, to reach very high column density sensitivity. To achieve even higher image fidelity, an accurate model of the WSRT primary beam was developed. This will be used in the joint deconvolution of the observations. To get a good overview of the distribution and kinematics of the Cosmic Web, a deep survey of 1500 square degrees of sky was undertaken, containing the galaxy filament extending between the Local Group and the Virgo Cluster. The auto-correlation data has been reduced and has an RMS of $\\Delta N_{HI} = 4.2\\times10^{16}$ cm$^{-2}$ over 20 kms$^{-1}$. Several sources have been tentatively detected, which were previously unknown, as well as an indication for diffuse intergalactic filaments.

Attila Popping; Robert Braun

2007-03-27

178

Stability and Reformation of Partially Eruptive Filament  

NASA Astrophysics Data System (ADS)

We present an observation of the confined partial filament eruption on 4 August 2012 which later exhibits a rapid reformation along the same magnetic channel within ?2 hours. We used BBSO and GONG Halpha as well as SDO AIA 171 Å observations to study the filament properties and its kinematics. SDO/AIA observations over the disk are used to study at coronal temperature the plasma dynamics associated with the filament. STEREO/SECCHI provides the limb observations of the filament dynamics. On the basis of the filament internal fine structure as evident in the Halpha observations and its position relative to the photospheric magnetic fields, it is found that the filament chirality is sinistral. On the other hand, the activated enveloping flux rope shows right-handed twist in the SDO/AIA 171 Å observations. Therefore, this dynamic event exhibits one-to-one correspondence between the filament chirality (sinistral) and the enveloping flux rope helicity (positive). Filament plasma goes into dynamic motion at ?11:20 UT from its middle part towards the north-west direction with an average speed of ?100 km s(-1) . Brightening underneath the eruptive part of the filament shows the most likely signature of low atmospheric reconnection. After traveling a distance of around ?215 Mm towards north-west, the cool filament plasma stops and returns back at ?12:00 UT towards its eastern foot point with the speed of ?60 km s(-1) . We calculated the coronal magnetic field decay index (n) near the flux rope. Using this estimation, we conjecture that the filament lies within the stability domain n <1, which is the cause of its stability and possibility of prompt reformation.

Joshi, Navin Chandra; Prasad Choudhary, Debi; Chandra, Ramesh; Srivastava, Abhishek K.; Dwivedi, B. N.; Kayshap, Pradeep; Filippov, Boris; Uddin, Wahab

179

Wind energy development in China  

Microsoft Academic Search

China's history in the use of wind energy is reviewed and its current development program is discussed. Current work includes aerodynamic optimization and computation for rotor performance, development of new wind machines and development of special generators. Prospect for long-term development are also discussed.

Dexin

1984-01-01

180

Drilling Machines: Vocational Machine Shop.  

ERIC Educational Resources Information Center

The lessons and supportive information in this field tested instructional block provide a guide for teachers in developing a machine shop course of study in drilling. The document is comprised of operation sheets, information sheets, and transparency masters for 23 lessons. Each lesson plan includes a performance objective, material and tools,…

Thomas, John C.

181

Machine Learning  

NASA Astrophysics Data System (ADS)

The purpose of this chapter is to present fundamental ideas and techniques of machine learning suitable for the field of this book, i.e., for automated scientific discovery. The chapter focuses on those symbolic machine learning methods, which produce results that are suitable to be interpreted and understood by humans. This is particularly important in the context of automated scientific discovery as the scientific theories to be produced by machines are usually meant to be interpreted by humans. This chapter contains some of the most influential ideas and concepts in machine learning research to give the reader a basic insight into the field. After the introduction in Sect. 1, general ideas of how learning problems can be framed are given in Sect. 2. The section provides useful perspectives to better understand what learning algorithms actually do. Section 3 presents the Version space model which is an early learning algorithm as well as a conceptual framework, that provides important insight into the general mechanisms behind most learning algorithms. In section 4, a family of learning algorithms, the AQ family for learning classification rules is presented. The AQ family belongs to the early approaches in machine learning. The next, Sect. 5 presents the basic principles of decision tree learners. Decision tree learners belong to the most influential class of inductive learning algorithms today. Finally, a more recent group of learning systems are presented in Sect. 6, which learn relational concepts within the framework of logic programming. This is a particularly interesting group of learning systems since the framework allows also to incorporate background knowledge which may assist in generalisation. Section 7 discusses Association Rules - a technique that comes from the related field of Data mining. Section 8 presents the basic idea of the Naive Bayesian Classifier. While this is a very popular learning technique, the learning result is not well suited for human comprehension as it is essentially a large collection of probability values. In Sect. 9, we present a generic method for improving accuracy of a given learner by generatingmultiple classifiers using variations of the training data. While this works well in most cases, the resulting classifiers have significantly increased complexity and, hence, tend to destroy the human readability of the learning result that a single learner may produce. Section 10 contains a summary, mentions briefly other techniques not discussed in this chapter and presents outlook on the potential of machine learning in the future.

Hoffmann, Achim; Mahidadia, Ashesh

182

An Analysis of the Hysteresis Motor I - Analysis of the Idealized Machine  

Microsoft Academic Search

This paper presents an analysis of an idealized polyphase hysteresis machine. The distributed magnetic field within the machine is described in terms of dimensions and windings. A single-phase equivalent circuit is developed for the machine and expressions are given for the parameters of this equivalent circuit and for the machine torque. Improvement of power factor by reduction of stator voltage

M. A. Copeland; G. R. Slemon

1963-01-01

183

The heat and cooling of electronically switching synchronous machine as a main drive of a car  

Microsoft Academic Search

The electromobil or hybrid-electromobil is equipped by an electric machine. This machine can work in a generator mode or in a motor mode. Because the size and weight of this type of machine are very limited, it is necessary (during the drive) to overload this machine for a short time. Consequently, the cooling system, the winding insulation system and power

Bohumil Skala

2011-01-01

184

Biophysics of Molecules Cytoskeletal filaments, Actin  

E-print Network

Biophysics of Molecules Cytoskeletal filaments, Actin polymerization and Actin Treadmilling Part 1 (26.11.2012) Dr. Carsten Grashoff MPI of Biochemistry E-mail: cgrasho@biochem.mpg.de #12;1. Actin dynamics and the f-actin network 2. Tubulin dynamics, the tubulin network and intermediate filaments

Kersting, Roland

185

Process for making silver metal filaments  

SciTech Connect

This invention relates to a process for making filaments of metal compounds and more particularly to a process for making silver metal filaments. The United States Government has rights to this invention pursuant to Contract No. DE-AC05-8421400 with Lockheed Martin Energy Systems, Inc. awarded by the US Department of Energy.

Bamberger, C.E.

1998-04-01

186

Evaluation of elasticity modulus for textiles filament  

NASA Astrophysics Data System (ADS)

Now, we propose a simple method of the elasticity modulus measurements for textiles filament using a mechanical pulse spectrometer. These measurements were performed for the polyamide filaments with a diameter about 11?m. Also we reanalyze the factors giving an experimental error. Estimation of the measurement error for our elasticity modulus is of a range 6,7%.

Wi?cek, Tomasz; P?kala, ?ukasz; Podko?cielny, Adam; Wasilewski, Andrzej

2008-01-01

187

Are filaments cylindrical or sheet-like?  

Microsoft Academic Search

A numerical model is presented for cooling gas regions collapsing into filaments around supernova remnants (SNR). Denser gas regions cool quicker than lower density regions and become even denser. The inner pressure reaches a lower state than outer pressure and a collapse occurs along warps in the original gas sheet. The filamentation then appears, together with a more ordered magnetic

M. D. Smith; J. R. Dickel

1983-01-01

188

Analysis of electromechanical interactions in a flywheel system with a doubly fed induction machine  

E-print Network

This paper analyzes the electromechanical inter-action in a flywheel system with a doubly fed induction machine, used for wind farm power smoothing or grid frequency response control. The grid-connected electrical machine ...

Ran, Li

189

Fullerene Machines  

NASA Technical Reports Server (NTRS)

Fullerenes possess remarkable properties and many investigators have examined the mechanical, electronic and other characteristics of carbon SP2 systems in some detail. In addition, C-60 can be functionalized with many classes of molecular fragments and we may expect the caps of carbon nanotubes to have a similar chemistry. Finally, carbon nanotubes have been attached to t he end of scanning probe microscope (Spill) tips. Spills can be manipulated with sub-angstrom accuracy. Together, these investigations suggest that complex molecular machines made of fullerenes may someday be created and manipulated with very high accuracy. We have studied some such systems computationally (primarily functionalized carbon nanotube gears and computer components). If such machines can be combined appropriately, a class of materials may be created that can sense their environment, calculate a response, and act. The implications of such hypothetical materials are substantial.

Globus, Al; Saini, Subhash (Technical Monitor)

1998-01-01

190

Fullerene Machines  

NASA Technical Reports Server (NTRS)

Recent computational efforts at NASA Ames Research Center and computation and experiment elsewhere suggest that a nanotechnology of machine phase functionalized fullerenes may be synthetically accessible and of great interest. We have computationally demonstrated that molecular gears fashioned from (14,0) single-walled carbon nanotubes and benzyne teeth should operate well at 50-100 gigahertz. Preliminary results suggest that these gears can be cooled by a helium atmosphere and a laser motor can power fullerene gears if a positive and negative charge have been added to form a dipole. In addition, we have unproven concepts based on experimental and computational evidence for support structures, computer control, a system architecture, a variety of components, and manufacture. Combining fullerene machines with the remarkable mechanical properties of carbon nanotubes, there is some reason to believe that a focused effort to develop fullerene nanotechnology could yield materials with tremendous properties.

Globus, Al; Saini, Subhash

1998-01-01

191

Simple Machines  

NSDL National Science Digital Library

Can you identify the six types of simple machines? 1. What do you know about Inclined Planes? Draw an example on your graphic organizer and state one fact.Inclined Plane 2. What do you know about levers? Draw an example on your graphic organizer and state one fact.Lever. 3. What do you know about pulleys? Draw an example on your graphic organizer and ...

Stewart, Miss

2010-03-24

192

Fatigue life prediction for wind turbines: A case study on loading spectra and parameter sensitivity  

Microsoft Academic Search

Wind turbines are fatigue-critical machines used to produce electrical energy from the wind. These rotating machines are subjected to environmental loadings that are highly irregular in nature. Historical examples of fatigue problems in both research and commercial wind turbine development are presented. Some example data on wind turbine environments, loadings and material properties are also shown. Before a description of

H. J. Sutherland; P. S. Veers; T. D. Ashwill

1992-01-01

193

A Generalized Deletion Machine  

E-print Network

In this work we prescribe a more generalized quantum-deleting machine (input state dependent). The fidelity of deletion is dependent on some machine parameters such that on alteration of machine parameters we get back to standard deleting machines. We also carried out a various comparative study of various kinds of quantum deleting machines. We also plotted graphs, making a comparative study of fidelity of deletion of the deletion machines, obtained as particular cases on changing the machine parameters of our machine.

Indranil Chakrabarty; Satyabrata Adhikari

2005-11-22

194

State-Machine Replication  

E-print Network

State-Machine Replication #12;The Problem Clients Server #12;The Problem Clients Server #12;The (state machine) #12;The Solution 1. Make server deterministic (state machine) State machine #12;The Solution 1. Make server deterministic (state machine) 2. Replicate server State machines #12;The Solution 1

Venkataramani, Arun

195

Automatic Detect and Trace of Solar Filaments  

NASA Astrophysics Data System (ADS)

We developed a series of methods to automatically detect and trace solar filaments in solar H? images. The programs are able to not only recognize filaments and determine their properties, such as the position, the area and other relevant parameters, but also to trace the daily evolution of the filaments. For solar full disk H? images, the method consists of three parts: first, preprocessing is applied to correct the original images; second, the Canny edge-detection method is used to detect the filaments; third, filament properties are recognized through the morphological operators. For each H? filament and its barb features, we introduced the unweighted undirected graph concept and adopted Dijkstra shortest-path algorithm to recognize the filament spine; then, using polarity inversion line shift method for measuring the polarities in both sides of the filament to determine the filament axis chirality; finally, employing connected components labeling method to identify the barbs and calculating the angle between each barb and spine to indicate the barb chirality. Our algorithms are applied to the observations from varied observatories, including the Optical & Near Infrared Solar Eruption Tracer (ONSET) in Nanjing University, Mauna Loa Solar Observatory (MLSO) and Big Bear Solar Observatory (BBSO). The programs are demonstrated to be effective and efficient. We used our method to automatically process and analyze 3470 images obtained by MLSO from January 1998 to December 2009, and a butterfly diagram of filaments is obtained. It shows that the latitudinal migration of solar filaments has three trends in the Solar Cycle 23: The drift velocity was fast from 1998 to the solar maximum; after the solar maximum, it became relatively slow and after 2006, the migration became divergent, signifying the solar minimum. About 60% filaments with the latitudes larger than 50 degree migrate towards the Polar Regions with relatively high velocities, and the latitudinal migrating speeds in the northern and the southern hemispheres do not differ significantly in the Solar Cycle 23. We also processed a number of relatively high-resolution H? images obtained by BBSO. It is found that in some cases, the filament axis has single chirality and the associated magnetic field also has single helicity, while its barbs in different parts of it have opposite barb chirality.

Fang, Cheng; Chen, P. F.; Tang, Yu-hua; Hao, Qi; Guo, Yang

196

Origin of Enigmatic Galactic-center Filaments Revealed  

NASA Astrophysics Data System (ADS)

Twenty years ago, astronomers discovered a number of enigmatic radio-emitting filaments concentrated near the center of the Milky Way Galaxy. These features initially defied explanation, but a new study of radio images of the Galactic center may point to their possible source. By combining data from the National Science Foundation's Very Large Array (VLA) and Robert C. Byrd Green Bank Telescope (GBT) astronomer Farhad Yusef-Zadeh of Northwestern University has found evidence that at least some of the filaments spring from the concentrated star-formation regions that populate the Galactic center. Galatic Center Combined VLA and GBT image (green) of the Galactic center, with red inset of GBT data only (red). Bright region on right is location of supermassive black hole. Linear filaments are visible above this area. CREDIT: NRAO/AUI/NSF Yusef-Zadeh, et.al. (Click on Image for Larger Version) Yusef-Zadeh presented his findings at the Denver, Colorado, meeting of the American Astronomical Society. William Cotton of the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, and William Hewitt of Northwestern University also contributed to this research. "Astronomers have long puzzled over the cause of these striking features," said Yusef-Zadeh, "and the turbulent nature of the Galactic center has made detailed analysis difficult. With new multi-wavelength radio images of the Galactic center, however, we can finally see a link between areas of starburst activity and these long-linear filaments." The filaments, which range from 10 to 100 light-years in length and are perhaps little more than 1 to 3 light-years across, occur only in a very narrow area, within approximately two degrees of the Galactic center (which translates to approximately 900 light-years across). Early theories about the origin of these filaments suggested that they were somehow related to the Milky Way’s own magnetic field. This was due to the fact that the first filaments detected were oriented perpendicular to the plane of the Galaxy, which would have aligned them with the Galaxy’s own magnetic field. "The problem with this hypothesis is that more recent images have revealed a population of weaker filaments oriented randomly in relation to the plane of the Galaxy," said Yusef-Zadeh. "This makes it difficult to explain the origin of the filaments by an organized Galactic magnetic field." In March and June of 2004, a team of astronomers using the GBT made images of the Galactic center at various wavelengths. The purpose of these surveys was to help identify radio features produced by hot gas (thermal emission) and those produced in magnetic fields (non-thermal emission). In general, thermal features radiate more strongly at shorter wavelengths and non-thermal at longer wavelengths. By comparing the GBT images with earlier VLA data taken of the same region, Yusef-Zadeh determined that a number of the non-thermal filaments seemed to connect to concentrated areas of thermal emission, which identify pockets of star formation. Galatic Center Combined radio image from the Very Large Array and Green Bank Telescope. The linear filaments near the top are some of the nonthermal radio filaments (NRFs) studied by the researchers. Other features, such as supernova remnants (SNRs) and the area surrounding our Galaxy's supermassive black hole (Sgr A) are shown. CREDIT: NRAO/AUI/NSF Yusef-Zadeh, et.al. (Click on Image for Larger Version) "What this showed us is that two seemingly disparate processes, thermal and non-thermal radio emission, can be created by the very same phenomenon," said Yusef-Zadeh. "In this case, that phenomenon is pockets of starburst activity." Yusef-Zadeh notes that the exact mechanism for how the areas of starburst generate the magnetic fields is still being investigated. "There are many ideas about the mechanism that generates these filaments," added Yusef-Zadeh, "but one possibility is that they are produced by the collision of winds blown off from indi

2004-06-01

197

Mechanotransduction down to individual actin filaments.  

PubMed

The actin cytoskeleton plays an essential role in a cell's ability to generate and sense forces, both internally and in interaction with the outside world. The transduction of mechanical cues into biochemical reactions in cells, in particular, is a multi-scale process which requires a variety of approaches to be understood. This review focuses on understanding how mechanical stress applied to an actin filament can affect its assembly dynamics. Today, experiments addressing this issue at the scale of individual actin filaments are emerging and bring novel insight into mechanotransduction. For instance, recent data show that actin filaments can act as mechanosensors, as an applied tension or curvature alters their conformation and their affinity for regulatory proteins. Filaments can also transmit mechanical tension to other proteins, which consequently change the way they interact with the filaments to regulate their assembly. These results provide evidence for mechanotransduction at the scale of individual filaments, showing that forces participate in the regulation of filament assembly and organization. They bring insight into the elementary events coupling mechanics and biochemistry in cells. The experiments presented here are linked to recent technical developments, and certainly announce the advent of more exciting results in the future. PMID:24252518

Romet-Lemonne, Guillaume; Jégou, Antoine

2013-01-01

198

Star forming filaments in warm dark models  

E-print Network

We performed a hydrodynamical cosmological simulation of the formation of a Milky Way-like galaxy in a warm dark matter (WDM) cosmology. Smooth and dense filaments, several co-moving mega parsec long, form generically above z 2 in this model. Atomic line cooling allows gas in the centres of these filaments to cool to the base of the cooling function, resulting in a very striking pattern of extended Lyman-limit systems (LLSs). Observations of the correlation function of LLSs might hence provide useful limits on the nature of the dark matter. We argue that the self-shielding of filaments may lead to a thermal instability resulting in star formation. We implement a sub-grid model for this, and find that filaments rather than haloes dominate star formation until z 6. Reionisation decreases the gas density in filaments, and the more usual star formation in haloes dominates below z 6, although star formation in filaments continues until z=2. Fifteen per cent of the stars of the z=0 galaxy formed in filaments. At hi...

Gao, Liang; Springel, Volker

2014-01-01

199

Contraction of Asymmetric Newtonian Liquid Filaments  

NASA Astrophysics Data System (ADS)

Understanding the dynamics of satellite drops is important in several industrial applications involving drop formation including inkjet printing, electrospraying and atomization. The precursor to these satellite drops is a slender liquid filament that connects an about-to-form drop to the rest of the liquid in the nozzle. Once a filament is formed, it either contracts into a single satellite or breaks into multiple satellites, due to surface tension. Our understanding of the contraction of Newtonian filaments in a passive ambient fluid has improved greatly over the past two decades thanks to the numerical analyses of Schulkes (1996) and Notz and Basaran (2004) who modeled the filaments as cylinders that are terminated by two identical spherical caps. However, in many situations, the filament shapes at the onset of formation may not be symmetric as in the aforementioned studies. To improve our understanding of the fluid mechanics of contraction of such asymmetric filaments, we study here the recoil of filaments whose initial shapes are sections of tapered axisymmetric cones that are terminated by two unequal spherical caps. The dynamics are studied by both a 2-D analysis and a 1-D slender-jet analysis, and the results are summarized by constructing phase diagrams involving the dimensionless groups governing the dynamics.

McGough, Patrick; Sambath, Krishnaraj; Appathurai, Santosh; Bhat, Pradeep; Harris, Michael; Basaran, Osman

2009-11-01

200

Comparison of hand laid-up tape and filament wound composite cylinders and panels with and without impact damage  

NASA Technical Reports Server (NTRS)

Experimentally determined axial compressive failure loads, strains and failure modes of composite flat panels and cylinders are presented. A comparison of two types of filament wound flat graphite-epoxy panels indicates that the winding pattern can influence structural response. A comparison of hand laid-up tape and filament wound composite cylinders indicates that fabrication method may not significantly influence the failure mode or average failure strain of thick-walled (radius-to-thickness ratio less than 15) graphite-epoxy cylinders. The interaction of manufacturing-induced features (fiber cross-overs) and low-speed impact damage for graphite-epoxy specimens is also presented. Filament would flat panels with many fiber cross-overs exhibited lower failure strains than filament wound panels without fiber cross-overs for all impact speeds examined. Graphite-thermoplastic cylinders exhibited a significantly different failure mode from the graphite-epoxy cylinders.

Jegley, Dawn C.; Lopez, Osvaldo F.

1991-01-01

201

Apparatus for cooling an electric machine  

DOEpatents

Provided is an apparatus, for example, for use with a rotating electric machine, that includes a housing. The housing can include a housing main portion and a housing end portion. The housing main portion can be configured to be disposed proximal to a body portion of a stator section of an electric machine. The housing main portion can define a main fluid channel that is configured to conduct fluid therethrough. The housing end portion can receive fluid from said main fluid channel and direct fluid into contact with a winding end portion of a conductive winding of the stator section.

Palafox, Pepe; Gerstler, William Dwight; Shen, Xiaochun; El-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Salasoo, Lembit

2013-07-16

202

Machine Design  

NSDL National Science Digital Library

This website, the homepage of Machine Design.com, contains resources on a variety of information for engineers and technicians related to devices, components, design applications, products, and systems in the manufacturing technology sector. The site also features a CAD library, eBooks, audiovisual aids, webinars, whitepapers and a reference center. Some of the resources require a free login. The page offers an RSS feed to keep users up to date on new resources. A free login may be required to access some of these items.

2009-11-09

203

Function Machine  

NSDL National Science Digital Library

This Java activity for the interactive white board (free access with registration) provides learners an opportunity to explore number functions and to predict outcomes. Teachers set the desired function from the drop-down list (double it, halve it, add 1, subtract 1, add 10, or subtract 10) and choose the start number from 1-20. Students are asked to predict the outcome before asking the machine to go. There is an option to hide the function so the teacher can ask students to work out what operation is being used to get from the starting number to the number generated.

2012-07-19

204

The Stokesian hydrodynamics of flexing, stretching filaments  

NASA Astrophysics Data System (ADS)

A central element of many fundamental problems in physics and biology lies in the interaction of a viscous fluid with slender, elastic filaments. Examples arise in the dynamics of biological fibers, the motility of microscopic organisms, and in phase transitions of liquid crystals. When considering the dynamics on the scale of a single filament, the surrounding fluid can often be assumed to be inertialess and hence governed by the Stokes’ equations. A typical simplification then is to assume a local relation, along the filament, between the force per unit length exerted by the filament upon the fluid and the velocity of the filament. While this assumption can be justified through slender-body theory as the leading-order effect, this approximation is only logarithmically separated (in aspect ratio) from the next-order contribution capturing the first effects of non-local interactions mediated by the surrounding fluid; non-local interactions become increasingly important as a filament comes within proximity to itself, or another filament. Motivated by a pattern forming system in isotropic to smectic-A phase transitions, we consider the non-local Stokesian dynamics of a growing elastica immersed in a fluid. The non-local interactions of the filament with itself are included using a modification of the slender-body theory of Keller and Rubinow. This modification is asymptotically equivalent, and removes an instability of their formulation at small, unphysical length-scales. Within this system, the filament lives on a marginal stability boundary, driven by a continual process of growth and buckling. Repeated bucklings result in filament flex, which, coupled to the non-local interactions and mediated by elastic response, leads to the development of space-filling patterns. We develop numerical methods to solve this system accurately and efficiently, even in the presence of temporal stiffness and the close self-approach of the filament. While we have ignored many of the thermodynamic aspects of this system, our simulations show good qualitative agreement with experimental observations. Our results also suggest that non-locality, induced by the surrounding fluid, will be important to understanding the dynamics of related filament systems.

Shelley, Michael J.; Ueda, Tetsuji

2000-11-01

205

Galactic winds in the intergalactic medium  

E-print Network

We have performed hydrodynamical simulations to investigate the effects of galactic winds on the high-redshift (z=3) universe. Strong winds suppress the formation of low-mass galaxies significantly, and the metals carried by them produce C IV absorption lines with properties in reasonable agreement with observations. The winds have little effect on the statistics of the H I absorption lines, because the hot gas bubbles blown by the winds fill only a small fraction of the volume and because they tend to escape into the voids, thereby leaving the filaments that produce these lines intact.

Tom Theuns; Matteo Viel; Scott Kay; Joop Schaye; Robert F. Carswell; Panayiotis Tzanavaris

2002-08-23

206

A bearingless method for induction machines  

Microsoft Academic Search

A bearingless induction motor system that uses standard windings is proposed. The theoretical assumptions are tested experimentally using a four-pole, two-phase machine without one mechanical bearing. The basic idea is the modulation of the stator winding currents to achieve positioning and rotary forces. Shaft deviations smaller than 0.5 mm at speeds of 4000 rpm are reached during the initial laboratory

Andres Ortiz Salazar; R. M. Stephan

1993-01-01

207

Advances of interior permanent magnet (IPM) wind generators  

Microsoft Academic Search

The current confluence of energy needs, enhanced environmental awareness and technical developments has led vigorous global efforts toward making wind power a key component of renewable and sustainable energy resources. The conventional wind generators are induction machine types having small and limited wind power production and high cost per unit. Large wind plants involving interior permanent magnet (IPM) synchronous generators

M. A. Rahman

2008-01-01

208

Filament overwrapped motor case technology  

NASA Astrophysics Data System (ADS)

Atlantic Research Corporation (ARC) joined with the French Societe Europeenne de Propulsion (SEP) to develop and deliver to the U.S. Navy a small quantity of composite filament wound rocket motors to demonstrate a manufacturing technique that was being applied at the two companies. It was perceived that the manufacturing technique could produce motors that would be light in weight, inexpensive to produce, and that had a good chance of meeting insensitive munitions (IM) requirements that were being formulated by the Navy in the early 1980s. Under subcontract to ARC, SEP designed, tested, and delivered 2.75-inch rocket motors to the U.S. Navy for IM tests that were conducted in 1989 at China Lake, California. The program was one of the first to be founded by Nunn Amendment money. The Government-to-Government program was sponsored by the Naval Air Systems Command and was monitored by the Naval Surface Warfare Center, Indian Head (NSWC-IH), Maryland. The motor propellant that was employed was a new, extruded composite formulation that was under development at the Naval Surface Warfare Center. The following paper describes the highlights of the program and gives the results of structural and ballistic static tests and insensitive munitions tests that were conducted on demonstration motors.

Compton, Joel P.

1993-11-01

209

The WSRT virgo filament survey  

E-print Network

In the last few years the realization has emerged that the universal baryons are almost equally distributed by mass in three components: (1) galactic concentrations, (2) a warm-hot intergalactic medium (WHIM) and (3) a diffuse intergalactic medium. These three components are predicted by hydrodynamical simulations and are probed by QSO absorption lines. To observe the WHIM in neutral hydrogen, observations are needed which are deeper than log(N$_{HI}$)=18. The WHIM should appear as a Cosmic Web, underlying the galaxies with higher column densities. We have used the WSRT, to simulate a filled aperture by observing at very high hour angles, to reach very high column density sensitivity. To achieve even higher image fidelity, an accurate model of the WSRT primary beam was developed. This will be used in the joint deconvolution of the observations. To get a good overview of the distribution and kinematics of the Cosmic Web, a deep survey of 1500 square degrees of sky was undertaken, containing the galaxy filament...

Popping, A; Popping, Attila; Braun, Robert

2007-01-01

210

Hybrid Wound Filaments for Greater Resistance to Impacts  

NASA Technical Reports Server (NTRS)

A hybrid material containing wound filaments made of a hybrid of high-strength carbon fibers and poly(phenylene benzobisoxazole) [PBO] fibers is discussed. This hybrid material is chosen in an effort to increase the ability of the pressure vessel to resist damage by low-speed impacts (e.g., dropping of tools on the vessel or bumping of the vessel against hard objects during installation and use) without significantly increasing the weight of the vessel. While the basic concept of hybridizing fibers in filament-wound structures is not new, the use of hybridization to increase resistance to impacts is an innovation, and can be expected to be of interest in the composite-pressure-vessel industry. The precise types and the proportions of the high-strength carbon fibers and the PBO fibers in the hybrid are chosen, along with the filament-winding pattern, to maximize the advantageous effects and minimize the disadvantageous effects of each material. In particular, one seeks to (1) take advantage of the ability of the carbon fibers to resist stress rupture while minimizing their contribution to vulnerability of the vessel to impact damage and (2) take advantage of the toughness of the PBO fibers while minimizing their contribution to vulnerability of the vessel to stress rupture. Experiments on prototype vessels fabricated according to this concept have shown promising results. At the time of reporting the information for this article, research toward understanding and optimizing the performances of PBO fibers so as to minimize their contribution to vulnerability of the pressure vessel to stress rupture had yet to be performed.

DeLay, Thomas K.; Patterson, James E.; Olson, Michael A.

2008-01-01

211

Iogenic Ion Loss via Magnetic Filaments in Jupiter's Magnetotail  

NASA Astrophysics Data System (ADS)

We show that energetic ions with Iogenic (sulfur-rich) composition are recurrently injected at 150 ±30RJ (RJ = 71,492 km) anti-sunward of Jupiter and funnelled down the magnetotail. The particle events show velocity dispersion and were observed during the first half of 2007 by the PEPSSI (Pluto Energetic Particle Spectrometer Science Investigation) instrument on the Pluto-bound New Horizons (NH) spacecraft. Our survey to 2562 RJ down the magnetotail characterizes the behavior of ˜few-keV—1 MeV particles and their environment, yielding an estimate of the injection site location. A case study of one of the most interesting of the many sulfur-rich events, beginning on day-of-year 118, 28 April 2007, contributes to the determination that the ˜400 RJ-wide > 9000RJ -long magnetotail is actually composed of narrow ˜1 RJ -diameter filaments stretching down the tail. Reconciling this with the large (˜500 RJ ) plasmoid interpretation supported by the NH/SWAP (Solar Wind Around Pluto) observations is an opportunity to greatly expand our understanding of the Jovian magnetotail and its particle dynamics. The impact of Io's vulcanism is clear as far down the tail as we observed, but between events the abundance of the solar wind tracer helium grows as the spacecraft recedes from the planet, possibly due to solar wind flux tubes mixing with the Jovian flux tubes liberating material trapped in the Io taurus and inner magnetosphere into interplanetary space.

Hill, Matthew; Haggerty, Dennis; McNutt, Ralph L., Jr.; Paranicas, Chris

212

High-Strength Undiffused Brushless (HSUB) Machine  

SciTech Connect

This paper introduces a new high-strength undiffused brushless machine that transfers the stationary excitation magnetomotive force to the rotor without any brushes. For a conventional permanent magnet (PM) machine, the air gap flux density cannot be enhanced effectively but can be weakened. In the new machine, both the stationary excitation coil and the PM in the rotor produce an enhanced air gap flux. The PM in the rotor prevents magnetic flux diffusion between the poles and guides the reluctance flux path. The pole flux density in the air gap can be much higher than what the PM alone can produce. A high-strength machine is thus obtained. The air gap flux density can be weakened through the stationary excitation winding. This type of machine is particularly suitable for electric and hybrid-electric vehicle applications. Patents of this new technology are either granted or pending.

Hsu, John S [ORNL; Tolbert, Leon M [ORNL; Lee, Seong T [ORNL

2007-01-01

213

High-Strength Undiffused Brushless (HSUB) Machine  

SciTech Connect

This paper introduces a new high-strength undiffused brushless machine that transfers the stationary excitation magnetomotive force to the rotor without any brushes. For a conventional permanent magnet (PM) machine, the air-gap flux density cannot be enhanced effectively but can be weakened. In the new machine, both the stationary excitation coil and the PM in the rotor produce an enhanced air-gap flux. The PM in the rotor prevents magnetic-flux diffusion between the poles and guides the reluctance flux path. The pole flux density in the air gap can be much higher than what the PM alone can produce. A high-strength machine is thus obtained. The air-gap flux density can be weakened through the stationary excitation winding. This type of machine is particularly suitable for electric and hybrid-electric vehicle applications. Patents of this new technology are either granted or pending.

Hsu, John S [ORNL] [ORNL; Lee, Seong T [ORNL] [ORNL; Tolbert, Leon M [ORNL] [ORNL

2008-01-01

214

Huge Filament Rises From Sun's Northern Hemisphere  

NASA Video Gallery

On August 1, 2010 following a C3-class solar flare from sunspot 1092, an enormous magnetic filament stretching across the sun's northern hemisphere erupted. This 304 angstrom video shows that filam...

215

Performance analysis of synchronous machines under dynamic eccentricity  

E-print Network

The performance of salient pole synchronous machines under eccentric rotors is studied. Relationships between stator and rotor current induced harmonics and dynamic eccentricity are investigated. The winding function theory has been modified...

Al-Nuaim, Nabil Abdulaziz

2012-06-07

216

Designing highly tunable semiflexible filament networks  

NASA Astrophysics Data System (ADS)

Semiflexible polymers can generate a range of filamentous networks significantly different in structure from those seen in conventional polymer solutions. Our coarse-grained simulations with an implicit cross-linker potential show that networks of branching bundles, knotted morphologies, and structural chirality can be generated by a generalized approach independent of specific cross-linkers. Network structure depends primarily on filament flexibility and separation, with significant connectivity increase after percolation. Results should guide the design of engineered semiflexible polymers.

Pandolfi, Ronald J.; Edwards, Lauren; Johnston, David; Becich, Peter; Hirst, Linda S.

2014-06-01

217

Study of filamentation threshold in zinc selenide.  

PubMed

The possibility of creating filaments with laser wavelengths ranging from 800 nm to 2.4 µm was investigated using an OPA laser system. Zinc Selenide's (ZnSe) unique characteristics - small band gap E(gZnSe)=2.67eV and positive dispersion for this wavelength range - are well suited for filamentation study where multi-photon absorption can be achieved with two to six photons. PMID:24663922

Durand, Magali; Houard, Aurélien; Lim, Khan; Durécu, Anne; Vasseur, Olivier; Richardson, Martin

2014-03-10

218

Role of Helicity in the Formation of Intermediate Filaments.  

E-print Network

theories of filament formation have been put for­ ward by Rust and Kumar (1995), Kuperus (1996), PriestRole of Helicity in the Formation of Intermediate Filaments. D.H. Mackay, E.R. Priest, School. To explain this pattern, a new theory for filament channel and filament formation is put forward. The theory

Mackay, Duncan

219

Mind & Machine  

NSDL National Science Digital Library

Mind & Machine is a weekly column provided by Ashley Dunn for the New York Times Cybertimes that discusses topics related to computing, technology, and the Internet. Recent columns have addressed the topics of the development of Internet telephony, possible futures of user interfaces, the history of technology and standards, and the Internet as a vehicle for community. Articles are well written, opinionated, and thought provoking. Mr. Dunn is a free lance writer who has written for such papers as the New York Times, the Los Angeles Times, the Seattle Post-Intelligencer, and the South China Morning Post. Note that the site is available only upon registration and is free of charge only in the US.

Dunn, Ashley.

1996-01-01

220

Ionization structure of the Crab Filaments  

NASA Astrophysics Data System (ADS)

The Crab filaments consist of gas photoionized by the radiation of the synchrotron nebula and hence are seen in emission lines. Recent HST-WFPC2 observations of the northern part of the nebula taken through several narrow line filters show a wealth of structure. The filamentary structure is a result of magnetic R-T instabilities at the interface between the synchrotron nebula and a swept up shell of ejecta (Hester et al, 1995, ApJ 456,225). Variations in the densities and magnetic fields at the interface produce a range of filament types, distinguishable by their ionization structure. We isolate individual filaments of different types and obtain their shapes and brightnesses. We then match these filament properties with photoionization models calculated using CLOUDY (Ferland, 1993, Univ. of Kentucky Department of Physics and Astronomy Internal Report). The model results, which are calculated in one dimension are converted to quasi two dimensional models assuming cylindrical geometry for the filaments. We obtain the range of observed filament properties by varying our model input parameters and examine the effect these variations have on a number of predicted line strengths and line ratios.

Sankrit, R.; Hester, J. J.; Scowen, P. A.

1996-09-01

221

Course info Machine Learning  

E-print Network

Course info Machine Learning Real life problems Lecture 1: Machine Learning Problem Qinfeng (Javen) Shi 28 July 2014 Intro. to Stats. Machine Learning COMP SCI 4401/7401 Qinfeng (Javen) Shi Lecture 1: Machine Learning Problem #12;Course info Machine Learning Real life problems Table of Contents I 1 Course

Shi, Qinfeng "Javen"

222

The influence of filament temperature and oxygen concentration on tungsten oxide nanostructures by hot filament metal oxide deposition  

Microsoft Academic Search

Tungsten oxide (WOx) nanostructures were prepared by a hot filament chemical vapour deposition system and the temperature of the hot tungsten filaments was changed by steps of degrees. The morphology and average growth rate were indicated by scanning electron microscopy which showed that the morphology was highly related to the filament temperature (Tf) and the distance between the filaments and

J Lou; B J Ye; H M Weng; H J Du; Z B Wang; X P Wang

2008-01-01

223

Wind Turbine Acoustics  

NASA Technical Reports Server (NTRS)

Wind turbine generators, ranging in size from a few kilowatts to several megawatts, are producing electricity both singly and in wind power stations that encompass hundreds of machines. Many installations are in uninhabited areas far from established residences, and therefore there are no apparent environmental impacts in terms of noise. There is, however, the potential for situations in which the radiated noise can be heard by residents of adjacent neighborhoods, particularly those neighborhoods with low ambient noise levels. A widely publicized incident of this nature occurred with the operation of the experimental Mod-1 2-MW wind turbine, which is described in detail elsewhere. Pioneering studies which were conducted at the Mod-1 site on the causes and remedies of noise from wind turbines form the foundation of much of the technology described in this chapter.

Hubbard, Harvey H.; Shepherd, Kevin P.

2009-01-01

224

Socially guided machine learning  

E-print Network

Social interaction will be key to enabling robots and machines in general to learn new tasks from ordinary people (not experts in robotics or machine learning). Everyday people who need to teach their machines new things ...

Thomaz, Andrea Lockerd

2006-01-01

225

Magnetic Couplings in a Bearingless Reluctance Machine  

Microsoft Academic Search

In this paper the problem of magnetic coupling between the motor and the radial bearing system in a bearingless reluctance machine is discussed. First the process of radial force production by interaction of two windings with different pole pair numbers is described. Numerical simulations are presented to show the influence of magnetic saturation on the force and torque generation. A

L. Hertel; W. Hofmann

226

Relationship of Species-Specific Filament Levels to Filamentous Bulking in Activated Sludge  

PubMed Central

To examine the relationship between activated-sludge bulking and levels of specific filamentous bacteria, we developed a statistics-based quantification method for estimating the biomass levels of specific filaments using 16S rRNA-targeted fluorescent in situ hybridization (FISH) probes. The results of quantitative FISH for the filament Sphaerotilus natans were similar to the results of quantitative membrane hybridization in a sample from a full-scale wastewater treatment plant. Laboratory-scale reactors were operated under different flow conditions to develop bulking and nonbulking sludge and were bioaugmented with S. natans cells to stimulate bulking. Instead of S. natans, the filament Eikelboom type 1851 became dominant in the reactors. Levels of type 1851 filaments extending out of the flocs correlated strongly with the sludge volume index, and extended filament lengths of approximately 6 × 108 ?m ml?1 resulted in bulking in laboratory-scale and full-scale activated-sludge samples. Quantitative FISH showed that high levels of filaments occurred inside the flocs in nonbulking sludge, supporting the “substrate diffusion limitation” hypothesis for bulking. The approach will allow the monitoring of incremental improvements in bulking control methods and the delineation of the operational conditions that lead to bulking due to specific filaments. PMID:15066840

Liao, Jiangying; Lou, Inchio; de los Reyes, Francis L.

2004-01-01

227

Evapotranspiration modelling using support vector machines \\/ Modélisation de l'évapotranspiration à l'aide de ‘support vector machines  

Microsoft Academic Search

This study investigates the accuracy of support vector machines (SVM), which are regression procedures, in modelling reference evapotranspiration (ET0). The daily meteorological data, solar radiation, air temperature, relative humidity and wind speed from three stations, Windsor, Oakville and Santa Rosa, in central California, USA, are used as inputs to the support vector machines to reproduce ET0 obtained using the FAO-56

OZGUR KI?I; MESUT ÇIMEN

2009-01-01

228

Machine musicianship  

NASA Astrophysics Data System (ADS)

The training of musicians begins by teaching basic musical concepts, a collection of knowledge commonly known as musicianship. Computer programs designed to implement musical skills (e.g., to make sense of what they hear, perform music expressively, or compose convincing pieces) can similarly benefit from access to a fundamental level of musicianship. Recent research in music cognition, artificial intelligence, and music theory has produced a repertoire of techniques that can make the behavior of computer programs more musical. Many of these were presented in a recently published book/CD-ROM entitled Machine Musicianship. For use in interactive music systems, we are interested in those which are fast enough to run in real time and that need only make reference to the material as it appears in sequence. This talk will review several applications that are able to identify the tonal center of musical material during performance. Beyond this specific task, the design of real-time algorithmic listening through the concurrent operation of several connected analyzers is examined. The presentation includes discussion of a library of C++ objects that can be combined to perform interactive listening and a demonstration of their capability.

Rowe, Robert

2002-05-01

229

Wind driven gas generator  

SciTech Connect

A means is provided to convert wind energy into electrical energy which, through electrolysis, forms gases to be stored under pressure, giving a form of stored energy for use at some future time by the use of a high torque, low speed vertical axis wind machine connected by direct drive to homopolar direct current generators so as to create direct current for the electrolysis of water, resulting in the breakdown of water into its basic components of hydrogen and oxygen, which are then stored under pressure until necessary for use as a source of energy.

Crehore, R.

1980-01-15

230

Steady State Operation of Self-Excited Induction Generator with Varying Wind Speeds  

Microsoft Academic Search

In contrast to conventional generators, self-excited induction generators are found to be most suitable machines for wind energy conversion in remote and windy areas due to many advantages over grid connected machines. However such machines exhibits poor performance in terms of voltage and frequency under frequent variations of operating speeds, which is a common feature in wind energy conversion. In

K. S. Sandhu; S. P. Jain

231

Monitoring the integrity of filament-wound structures using built-in sensor networks  

NASA Astrophysics Data System (ADS)

Monitoring the integrity of filament wound composite structures such as solid rocket motors and liquid fuel bottles is important in order to prevent catastrophic failures and to prolong the service life of these structures. To ensure the safety and reliability of rocket components, they require frequent inspection for structural damages that might have occurred during manufacturing, transportation, and storage. The timely and accurate detection, characterization and monitoring of structural cracking, delamination, debonding and other types of damage is a major concern in the operational environment. Utilization of a sensor network system integrated with the structure itself can greatly reduce this inspection burden through fast in-situ data collection and processing. Acellent Technologies, Inc. is currently developing integrated structural monitoring tools for continuous monitoring of composite and metal structures on aircraft and spacecraft. Acellent's integrated structural monitoring system consists of a flexible sensor/actuator network layer called the SMART Layer, supporting diagnostic hardware, and data processing/analysis software. Recently, Acellent has been working with NASA Marshall Space Flight Center to develop ways of embedding the SMART Layer inside filament wound composite bottles. SMART Layers were designed and manufactured for the filament wound bottles and embedded in them during the filament winding process. Acellent has been working on developing a complete structural health monitoring system for the filament wound bottles including data processing tools to interpret the changes in sensor signal caused by changes in the structural condition or material property. A prototype of a filament wound composite bottle with an embedded sensor network has been fabricated and preliminary data analysis tools have been developed.

Lin, Mark; Kumar, Amrita; Qing, Xinlin; Beard, Shawn J.; Russell, Samuel S.; Walker, James L.; Delay, Thomas K.

2003-08-01

232

On the nature of star-forming filaments - I. Filament morphologies  

NASA Astrophysics Data System (ADS)

We use a suite of high-resolution molecular cloud simulations carried out with the moving mesh code AREPO to explore the nature of star-forming filaments. The simulated filaments are identified and categorized from column density maps in the same manner as for recent Herschel observations. When fitted with a Plummer-like profile, the filaments are in excellent agreement with observations, and have shallow power-law profiles of p ˜ 2.2 without the need for magnetic support. When data within 1 pc of the filament centre are fitted with a Gaussian function, the average full width at half-maximum (FWHM) is ˜0.3 pc, in agreement with predictions for accreting filaments. However, if the fit is constructed using only the inner regions, as in Herschel observations, the resulting FWHM is only ˜0.2 pc. This value is larger than that measured in IC 5146 and Taurus, but is similar to that found in the Planck Galactic cold cores and in Cygnus X. The simulated filaments have a range of widths rather than a constant value. When the column density maps are compared to the 3D gas densities, the filaments seen in column density do not belong to a single structure. Instead, they are made up of a network of short ribbon-like sub-filaments reminiscent of those seen in Taurus. The sub-filaments are pre-existing within the simulated clouds, have radii similar to their Jeans radius, and are not primarily formed through fragmentation of the larger filament seen in column density. Instead, small filamentary clumps are swept together into a single column density structure by the large-scale collapse of the cloud.

Smith, Rowan J.; Glover, Simon C. O.; Klessen, Ralf. S.

2014-12-01

233

Nebulin binding impedes mutant desmin filament assembly  

PubMed Central

Desmin intermediate filaments (DIFs) form an intricate meshwork that organizes myofibers within striated muscle cells. The mechanisms that regulate the association of desmin to sarcomeres and their role in desminopathy are incompletely understood. Here we compare the effect nebulin binding has on the assembly kinetics of desmin and three desminopathy-causing mutant desmin variants carrying mutations in the head, rod, or tail domains of desmin (S46F, E245D, and T453I). These mutants were chosen because the mutated residues are located within the nebulin-binding regions of desmin. We discovered that, although nebulin M160–164 bound to both desmin tetrameric complexes and mature filaments, all three mutants exhibited significantly delayed filament assembly kinetics when bound to nebulin. Correspondingly, all three mutants displayed enhanced binding affinities and capacities for nebulin relative to wild-type desmin. Electron micrographs showed that nebulin associates with elongated normal and mutant DIFs assembled in vitro. Moreover, we measured significantly delayed dynamics for the mutant desmin E245D relative to wild-type desmin in fluorescence recovery after photobleaching in live-cell imaging experiments. We propose a mechanism by which mutant desmin slows desmin remodeling in myocytes by retaining nebulin near the Z-discs. On the basis of these data, we suggest that for some filament-forming desmin mutants, the molecular etiology of desminopathy results from subtle deficiencies in their association with nebulin, a major actin-binding filament protein of striated muscle. PMID:23615443

Baker, Laura K.; Gillis, David C.; Sharma, Sarika; Ambrus, Andy; Herrmann, Harald; Conover, Gloria M.

2013-01-01

234

Interaction and Merging of two Sinistral Filaments  

NASA Astrophysics Data System (ADS)

In this paper, we report the interaction and subsequent merging of two sinistral filaments (F1 and F2) occurring at the boundary of AR 9720 on 2001 December 6. The two filaments were close and nearly perpendicular to each other. The interaction occurred after F1 was erupted and the eruption was impeded by a more extended filament channel (FC) standing in the way, in which F2 was embedded. The erupted material ran into FC along its axis, causing F1 and F2 to merge into a single structure that subsequently underwent a large-amplitude to-and-fro motion. A significant plasma heating process was observed in the merging process, making the mixed material largely disappear from the H? passband, but appear in Extreme Ultraviolet Telescope 195 Å images for a while. These observations can serve as strong evidence of merging reconnection between the two colliding magnetic structures. A new sinistral filament was formed along FC after the cooling of the merged and heated material. No coronal mass ejection was observed to be associated with the event; though, the eruption was accompanied by a two-ribbon flare with a separation motion, indicating that the eruption had failed. This event shows that, in addition to overlying magnetic fields, such an interaction is an effective restraint to make a filament eruption fail in this way.

Jiang, Yunchun; Yang, Jiayan; Wang, Haimin; Ji, Haisheng; Liu, Yu; Li, Haidong; Li, Jianping

2014-09-01

235

The wind program in a typhoon environment  

NASA Astrophysics Data System (ADS)

The present wind program in the Republic of China (including Taiwan and the off-shore islands under ROC control) is discussed. The collection of wind data in hopeful windmill sites, especially those on offshore islands and coastal areas is discussed. The installation of experimental small wind machines in the above-mentioned sites is described. For example, some small machines will be set up this year in Quemoy for pumping of irrigation water while others will be used for salt-making in the Southern Coast of Taiwan. An evaluation of available Wind energy in Taiwan is given. The assessment of the effect of typhoon on the safety, cost and operation of wind machines is discussed

Tsao, Y. S.

236

A decision support model for travelling gun irrigation machines  

Microsoft Academic Search

The computer model, TRAVGUN was developed to simulate the irrigation applications by travelling gun machines under different wind conditions. A novel approach to calibration of the model was introduced to give both the sprinkler pattern (radial leg) and the six wind parameters of the empirical sprinkler irrigation model, from simple field measurements of applied depths along transects perpendicular to the

R. J. Smith; M. H. Gillies; G. Newell; J. P. Foley

2008-01-01

237

Hybrid-secondary uncluttered induction machine  

DOEpatents

An uncluttered secondary induction machine (100) includes an uncluttered rotating transformer (66) which is mounted on the same shaft as the rotor (73) of the induction machine. Current in the rotor (73) is electrically connected to current in the rotor winding (67) of the transformer, which is not electrically connected to, but is magnetically coupled to, a stator secondary winding (40). The stator secondary winding (40) is alternately connected to an effective resistance (41), an AC source inverter (42) or a magnetic switch (43) to provide a cost effective slip-energy-controlled, adjustable speed, induction motor that operates over a wide speed range from below synchronous speed to above synchronous speed based on the AC line frequency fed to the stator.

Hsu, John S. (Oak Ridge, TN)

2001-01-01

238

Wind farm location and environmental impact  

Microsoft Academic Search

Though wind power is now cheap enough to be economic, and its technical feasibility has been demonstrated to produce the equivalent energy generation capacity of a power station, still requires hundreds of very large machines or even thousands of smaller ones. One remaining uncertainty concerns the environmental impact of this and the resulting public attitudes. Large machines, which could be

A. Clarke

1989-01-01

239

SOLAR MAGNETIZED 'TORNADOES': RELATION TO FILAMENTS  

SciTech Connect

Solar magnetized 'tornadoes', a phenomenon discovered in the solar atmosphere, appear as tornado-like structures in the corona but are rooted in the photosphere. Like other solar phenomena, solar tornadoes are a feature of magnetized plasma and therefore differ distinctly from terrestrial tornadoes. Here we report the first analysis of solar 'tornadoes' (two papers which focused on different aspects of solar tornadoes were published in the Astrophysical Journal Letters and Nature, respectively, during the revision of this Letter). A detailed case study of two events indicates that they are rotating vertical magnetic structures probably driven by underlying vortex flows in the photosphere. They usually exist as a group and are related to filaments/prominences, another important solar phenomenon whose formation and eruption are still mysteries. Solar tornadoes may play a distinct role in the supply of mass and twists to filaments. These findings could lead to a new explanation of filament formation and eruption.

Su Yang; Veronig, Astrid; Temmer, Manuela [IGAM-Kanzelhoehe Observatory, Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Wang Tongjiang [Department of Physics, Catholic University of America, Washington, DC 20064 (United States); Gan Weiqun, E-mail: yang.su@uni-graz.at [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

2012-09-10

240

Filament velocity scaling laws for warm ions  

SciTech Connect

The dynamics of filaments or blobs in the scrape-off layer of magnetic fusion devices are studied by magnitude estimates of a comprehensive drift-interchange-Alfvén fluid model. The standard blob models are reproduced in the cold ion case. Even though usually neglected, in the scrape-off layer, the ion temperature can exceed the electron temperature by an order of magnitude. The ion pressure affects the dynamics of filaments amongst others by adding up to the interchange drive and the polarisation current. It is shown how both effects modify the scaling laws for filament velocity in dependence of its size. Simplifications for experimentally relevant limit regimes are given. These are the sheath dissipation, collisional, and electromagnetic regime.

Manz, P. [Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany) [Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany); Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Carralero, D.; Birkenmeier, G.; Müller, H. W.; Scott, B. D. [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany)] [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Müller, S. H. [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego 92093 (United States)] [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego 92093 (United States); Fuchert, G. [Insitut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, 70569 Stuttgart (Germany)] [Insitut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, 70569 Stuttgart (Germany); Stroth, U. [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany) [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany)

2013-10-15

241

Solar Magnetized "Tornadoes:" Relation to Filaments  

NASA Astrophysics Data System (ADS)

Solar magnetized "tornadoes," a phenomenon discovered in the solar atmosphere, appear as tornado-like structures in the corona but are rooted in the photosphere. Like other solar phenomena, solar tornadoes are a feature of magnetized plasma and therefore differ distinctly from terrestrial tornadoes. Here we report the first analysis of solar "tornadoes" (two papers which focused on different aspects of solar tornadoes were published in the Astrophysical Journal Letters and Nature, respectively, during the revision of this Letter). A detailed case study of two events indicates that they are rotating vertical magnetic structures probably driven by underlying vortex flows in the photosphere. They usually exist as a group and are related to filaments/prominences, another important solar phenomenon whose formation and eruption are still mysteries. Solar tornadoes may play a distinct role in the supply of mass and twists to filaments. These findings could lead to a new explanation of filament formation and eruption.

Su, Yang; Wang, Tongjiang; Veronig, Astrid; Temmer, Manuela; Gan, Weiqun

2012-09-01

242

Filament Twist in F-Actin Bundles  

NASA Astrophysics Data System (ADS)

The twist state of F-actin can modify specific binding sites and influence the hierarchy of interactions in cytoskeletal regulation. F-actin in the cytoskeleton is often organized into bundles, using a wide variety of cationic molecules and actin-linking proteins. The native helical symmetry of uncondensed f-actin filaments is not necessarily the preferred symmetry of bundled filaments, which will depend on the particular bundling mechanism and the kind of condensing agent used. In order to explore the role of filament distortion in the process of bundle formation, we have carried out a series of synchrotron x-ray measurements on systems of bundled f-actin, using multivalent cations, cationic globular proteins, and actin binding proteins. Preliminary results will be presented. This work was supported by NSF DMR-0071761, DOE, DEFG02-91ER45439, the Beckman Young Investigator Program, and the Cystic Fibrosis Foundation.

Angelini, Tommy; Sanders, Lori; Wong, Gerard

2003-03-01

243

Spatiotemporal rogue events in optical multiple filamentation.  

PubMed

The transient appearance of bright spots in the beam profile of optical filaments formed in xenon is experimentally investigated. Fluence profiles are recorded with high-speed optical cameras at the kilohertz repetition rate of the laser source. A statistical analysis reveals a thresholdlike appearance of heavy-tailed fluence distributions together with the transition from single to multiple filamentation. The multifilament scenario exhibits near-exponential probability density functions, with extreme events exceeding the significant wave height by more than a factor of 10. The extreme events are isolated in space and in time. The macroscopic origin of these experimentally observed heavy-tail statistics is shown to be local refractive index variations inside the nonlinear medium, induced by multiphoton absorption and subsequent plasma thermalization. Microscopically, mergers between filament strings appear to play a decisive role in the observed rogue wave statistics. PMID:24483663

Birkholz, Simon; Nibbering, Erik T J; Brée, Carsten; Skupin, Stefan; Demircan, Ayhan; Genty, Goëry; Steinmeyer, Günter

2013-12-13

244

The axial filament antigen of Treponema pallidum.  

PubMed Central

Axial filaments (flagella) of Treponema pallidum have been purified in large enough quantities to be analysed electrophoretically. They produced a characteristic linear precipitate in two-dimensional immunoelectrophoresis. Polyacrylamide gel electrophoresis showed three major polypeptides, the most prominent having an apparent molecular weight of 37,000, about 1500 less than the corresponding component of axial filaments of the Reiter treponeme. A doublet of less abundant polypeptides of 33,500-34,000 MW also differed slightly from those of the Reiter treponeme. Western blot analysis showed that the principal polypeptide of the T. pallidum axial filament was strongly antigenic, and antibody to it was prominent in sera from hyperimmunized, as well as acutely infected (orchitic), rabbits, and in soluble fractions from acutely infected rabbit testes from which large numbers of viable treponemes had been extracted. This indicated that antibody to this component was ineffective in eliminating treponemes from the tissue. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:3884491

Penn, C W; Bailey, M J; Cockayne, A

1985-01-01

245

Wind turbines in simulated gusts  

Microsoft Academic Search

The results of trials in the T4 wind tunnel to simulate the effects of gusts on wind turbines are reported. Three-bladed NACA 0012 and 0018 profile and a six bladed 0012 profile machines were examined in gusts of 10 sec duration. The mean free stream velocity was 7-8 m\\/sec and the gusts generated had an amplitude of 30-40 pct. An

C. Egozcue; R. Leblanc; R. Goethals

1982-01-01

246

Performance Analysis of Small Wind Turbine Connected to a Grid through Modelling and Simulation  

Microsoft Academic Search

This paper focuses on the modelling and performance analysis of small Wind Turbine Generator (WTG). A specially developed pole changeable induction machine, which is directly connected into a grid, is considered for simulation. The mathematical equations of the induction machine, wind turbine, grid are simulated in powerful software tool Matlab\\/Simulink. The dynamic analysis has been carried out by changing wind

Rajesh Saiju; Abdel Tamzarti; Siegfried Heier

2007-01-01

247

Machines registres Yves Lafont  

E-print Network

Machines à registres Yves Lafont Université d'Aix-Marseille Institut de Mathématiques de Luminy) Pascal Turing Von Neumann #12;Quelle opération calcule cette machine ? Exemple 1 2 registres : (+ 1 Quelle opération calcule cette machine ? #12;Quelle propriété teste cette machine ? Exemple 3 1 seul

Lafont, Yves

248

Terahertz radiation from a laser plasma filament  

SciTech Connect

By the use of two-dimensional particle-in-cell simulations, we clarify the terahertz (THz) radiation mechanism from a plasma filament formed by an intense femtosecond laser pulse. The nonuniform plasma density of the filament leads to a net radiating current for THz radiation. This current is mainly located within the pulse and the first cycle of the wakefield. As the laser pulse propagates, a single-cycle and radially polarized THz pulse is constructively built up forward. The single-cycle shape is mainly due to radiation damping effect.

Wu, H.-C.; Meyer-ter-Vehn, J. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Ruhl, H. [Department fuer Physik der Ludwig-Maximillians-Universitaet, Theresienstrasse 37A, D-80333 Muenchen (Germany); Sheng, Z.-M. [Institute of Plasma Studies, Department of Physics, Shanghai Jiaotong University, Shanghai 200240 (China); Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China)

2011-03-15

249

Current Filamentation Instability in Laser Wakefield Accelerators  

SciTech Connect

Experiments using an electron beam produced by laser-wakefield acceleration have shown that varying the overall beam-plasma interaction length results in current filamentation at lengths that exceed the laser depletion length in the plasma. Three-dimensional simulations show this to be a combination of hosing, beam erosion, and filamentation of the decelerated beam. This work suggests the ability to perform scaled experiments of astrophysical instabilities. Additionally, understanding the processes involved with electron beam propagation is essential to the development of wakefield accelerator applications.

Huntington, C. M.; Drake, R. P. [Atmospheric, Oceanic and Space Science, University of Michigan, Ann Arbor, Michigan, 48103 (United States); Thomas, A. G. R.; McGuffey, C.; Matsuoka, T.; Chvykov, V.; Kalintchenko, G.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Kneip, S.; Najmudin, Z.; Palmer, C. [Blackett Laboratory, Imperial College London, London, SW7 2BZ (United Kingdom); Katsouleas, T. [Platt School of Engineering, Duke University, Durham, North Carolina, 27708 (United States)

2011-03-11

250

Reversibility of filamentous carbon growth and gasification  

SciTech Connect

Controlled atmosphere electron microscopy observations of the nickel-catalyzed growth and gasification of carbon filaments have shown that these processes can be reversed. This supports the view that growth and gasification in either hydrogen or steam occur by similar mechanisms, where one of the steps involves the diffusion of carbon through the metal. It was observed that the small catalyst particles are the most active in filament formation and steam gasification, while the large particles are the most active for the hydrogenation reaction. This is explained in terms of different rate-controlling steps.

Figueiredo, J.L.; Bernardo, C.A.; Chludzinski, J.J. Jr.; Baker, R.T.K.

1988-03-01

251

Enhancement of filamentation postcompression by astigmatic focusing.  

PubMed

The energy scaling up of pulse postcompression is still an open issue. In this work we analyze the use of astigmatic focusing to improve the output pulses in a filamentation based postcompression setup. Unlike spherical conditions, astigmatic focusing enhances the output energy and the spectral broadening of the filament. This is due to the increase of critical power, allowing a considerable improvement of the postcompression energy and stability in a simple way. We demonstrated compression from FWHM 100 fs, 10 nm, 3 mJ input pulses to 13 fs, 142 nm, near 1 mJ pulses. PMID:21964124

Alonso, Benjamín; Borrego-Varillas, Rocío; Sola, Íñigo J; Varela, Óscar; Villamarín, Ayalid; Collados, M Victoria; Román, Julio San; Bueno, Juan M; Roso, Luis

2011-10-01

252

Molecular Emission From Filaments In Cooling Flows  

NASA Astrophysics Data System (ADS)

Infrared and radio observations reveal large reservoirs of molecular gas in optical filaments seen in cooling flows in clusters of galaxies. Recent Spitzer observations show that molecular hydrogen emission occurs over a broad range of temperatures, ranging from roughly 300 K to 2000 K. Central questions involve the history of the filaments, their total mass, and the energy sources responsible for the molecular hydrogen and low-ionization emission. Here we present numerical simulations of the effects of cosmic rays or thermalized heating upon otherwise well shielded molecular gas. We show diagnostic excitation and emission diagrams and discuss implications for the nature of the emission.

Ferland, Gary J.; Fabian, A. C.; Hatch, N. A.; Johnstone, R. M.; Porter, R. L.; van Hoof, P. A. M.; Williams, R. J. R.

2007-12-01

253

Filamentary structures in dense plasma focus: Current filaments or vortex filaments?  

NASA Astrophysics Data System (ADS)

Recent observations of an azimuthally distributed array of sub-millimeter size sources of fusion protons and correlation between extreme ultraviolet (XUV) images of filaments with neutron yield in PF-1000 plasma focus have re-kindled interest in their significance. These filaments have been described variously in literature as current filaments and vortex filaments, with very little experimental evidence in support of either nomenclature. This paper provides, for the first time, experimental observations of filaments on a table-top plasma focus device using three techniques: framing photography of visible self-luminosity from the plasma, schlieren photography, and interferometry. Quantitative evaluation of density profile of filaments from interferometry reveals that their radius closely agrees with the collision-less ion skin depth. This is a signature of relaxed state of a Hall fluid, which has significant mass flow with equipartition between kinetic and magnetic energy, supporting the "vortex filament" description. This interpretation is consistent with empirical evidence of an efficient energy concentration mechanism inferred from nuclear reaction yields.

Soto, Leopoldo; Pavez, Cristian; Castillo, Fermin; Veloso, Felipe; Moreno, José; Auluck, S. K. H.

2014-07-01

254

Numerical simulation of vortex breakdown by the vortex-filament method  

NASA Technical Reports Server (NTRS)

The vortex-filament method was applied to the simulation of vortex breakdown. The principal vortex region was represented by multiple filaments, and an axial velocity component was induced by a spiral winding of the filaments. An accuracy check was performed for a cylindrical swirling flow with simple analytical expressions for the axial and theta velocities. The result suggests that the flow field can be simulated to any accuracy by increasing the number of filaments. An axisymmetric-type vortex breakdown was simulated, with experimental data serving as upstream conditions. The calculated axial- and theta-velocity contours show the breakdown of the vortex, including a rapid change in the vortex core, followed axially by a recovery zone and then a second breakdown. When three dimensional initial data are used the second breakdown appears to be of the spiral type in correspondence with experimental observations. The present method can easily be used to simulate other types of vortex breakdown or other vortex flows with axial velocity.

Nakamura, Y.; Leonard, A.; Spalart, P. R.

1983-01-01

255

Large, low cost composite wind turbine blades  

NASA Technical Reports Server (NTRS)

A woven roving E-glass tape, having all of its structural fibers oriented across the tape width was used in the manufacture of the spar for a wind turbine blade. Tests of a 150 ft composite blade show that the transverse filament tape is capable of meeting structural design requirements for wind turbine blades. Composite blades can be designed for interchangeability with steel blades in the MOD-1 wind generator system. The design, analysis, fabrication, and testing of the 150 ft blade are discussed.

Gewehr, H. W.

1979-01-01

256

GRAVITATIONAL INFALL ONTO MOLECULAR FILAMENTS. II. EXTERNALLY PRESSURIZED CYLINDERS  

SciTech Connect

Two aspects of the evolution of externally pressurized, hydrostatic filaments are discussed. (1) The free-fall accretion of gas onto such a filament will lead to filament parameters (specifically, FWHM-column-density relations) inconsistent with the observations of Arzoumanian et al., except for two cases: for low-mass, isothermal filaments, agreement is found as in the analysis by Fischera and Martin. Magnetized cases, for which the field scales weakly with the density as B?n {sup 1/2}, also reproduce observed parameters. (2) Realistically, the filaments will be embedded not only in gas of non-zero pressure, but also of non-zero density. Thus, the appearance of sheet-embedded filaments is explored. Generating a grid of filament models and comparing the resulting column density ratios and profile shapes with observations suggests that the three-dimensional filament profiles are intrinsically flatter than isothermal, beyond projection and evolution effects.

Heitsch, Fabian, E-mail: fheitsch@unc.edu [Department of Physics and Astronomy, University of North Carolina Chapel Hill, Chapel Hill, NC 27599-3255 (United States)

2013-10-10

257

Radial interchange motions of plasma filaments  

SciTech Connect

Radial convection of isolated filamentary structures due to interchange motions in magnetized plasmas is investigated. Following a basic discussion of vorticity generation, ballooning, and the role of sheaths, a two-field interchange model is studied by means of numerical simulations on a biperiodic domain perpendicular to the magnetic field. It is demonstrated that a blob-like plasma structure develops dipolar vorticity and electrostatic potential fields, resulting in rapid radial acceleration and formation of a steep front and a trailing wake. While the dynamical evolution strongly depends on the amount of collisional diffusion and viscosity, the structure travels a radial distance many times its initial size in all parameter regimes in the absence of sheath dissipation. In the ideal limit, there is an inertial scaling for the maximum radial velocity of isolated filaments. This velocity scales as the acoustic speed times the square root of the structure size relative to the length scale of the magnetic field. The plasma filament eventually decelerates due to mixing and collisional dissipation. Finally, the role of sheath dissipation is investigated. When included in the simulations, it significantly reduces the radial velocity of isolated filaments. The results are discussed in the context of convective transport in scrape-off layer plasmas, comprising both blob-like structures in low confinement modes and edge localized mode filaments in unstable high confinement regimes.

Garcia, O. E.; Bian, N. H.; Fundamenski, W. [Association EURATOM-Risoe National Laboratory, P.O. Box 49, OPL-128 Risoe, DK-4000 Roskilde (Denmark); School of Physics and Astronomy, University of Manchester, Manchester M60 1QD (United Kingdom); EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2006-08-15

258

Conformational phases of membrane bound cytoskeletal filaments  

NASA Astrophysics Data System (ADS)

Membrane bound cytoskeletal filaments found in living cells are employed to carry out many types of activities including cellular division, rigidity and transport. When these biopolymers are bound to a membrane surface they may take on highly non-trivial conformations as compared to when they are not bound. This leads to the natural question; What are the important interactions which drive these polymers to particular conformations when they are bound to a surface? Assuming that there are binding domains along the polymer which follow a periodic helical structure set by the natural monomeric handedness, these bound conformations must arise from the interplay of the intrinsic monomeric helicity and membrane binding. To probe this question, we study a continuous model of an elastic filament with intrinsic helicity and map out the conformational phases of this filament for various mechanical and structural parameters in our model, such as elastic stiffness and intrinsic twist of the filament. Our model allows us to gain insight into the possible mechanisms which drive real biopolymers such as actin and tubulin in eukaryotes and their prokaryotic cousins MreB and FtsZ to take on their functional conformations within living cells.

Quint, David A.; Grason, Gregory; Gopinathan, Ajay

2013-03-01

259

Organic Acid Production by Filamentous Fungi  

E-print Network

12 Organic Acid Production by Filamentous Fungi Jon K. Magnuson and Linda L. Lasure 1. Introduction Many of the commercial production processes for organic acids are excellent examples of fungal biotechnology. However, unlike penicillin, the organic acids have had a less vis- ible impact on human well

260

Actin organization and dynamics in filamentous fungi  

Microsoft Academic Search

Growth and morphogenesis of filamentous fungi is underpinned by dynamic reorganization and polarization of the actin cytoskeleton. Actin has crucial roles in exocytosis, endocytosis, organelle movement and cytokinesis in fungi, and these processes are coupled to the production of distinct higher-order structures (actin patches, cables and rings) that generate forces or serve as tracks for intracellular transport. New approaches for

Adokiye Berepiki; Alexander Lichius; Nick D. Read

2011-01-01

261

Drebrin-induced Stabilization of Actin Filaments*  

PubMed Central

Drebrin is a mammalian neuronal protein that binds to and organizes filamentous actin (F-actin) in dendritic spines, the receptive regions of most excitatory synapses that play a crucial role in higher brain functions. Here, the structural effects of drebrin on F-actin were examined in solution. Depolymerization and differential scanning calorimetry assays show that F-actin is stabilized by the binding of drebrin. Drebrin inhibits depolymerization mainly at the barbed end of F-actin. Full-length drebrin and its C-terminal truncated constructs were used to clarify the domain requirements for these effects. The actin binding domain of drebrin decreases the intrastrand disulfide cross-linking of Cys-41 (in the DNase I binding loop) to Cys-374 (C-terminal) but increases the interstrand disulfide cross-linking of Cys-265 (hydrophobic loop) to Cys-374 in the yeast mutants Q41C and S265C, respectively. We also demonstrate, using solution biochemistry methods and EM, the rescue of filament formation by drebrin in different cases of longitudinal interprotomer contact perturbation: the T203C/C374S yeast actin mutant and grimelysin-cleaved skeletal actin (between Gly-42 and Val-43). Additionally, we show that drebrin rescues the polymerization of V266G/L267G, a hydrophobic loop yeast actin mutant with an impaired lateral interface formation between the two filament strands. Overall, our data suggest that drebrin stabilizes actin filaments through its effect on their interstrand and intrastrand contacts. PMID:23696644

Mikati, Mouna A.; Grintsevich, Elena E.; Reisler, Emil

2013-01-01

262

Modeling and control of a wind turbine driven doubly fed induction generator  

Microsoft Academic Search

This paper presents the simulation results of a grid-connected wind driven doubly fed induction machine (DFIM) together with some real machine performance results. The modeling of the machine considers operating conditions below and above synchronous speed, which are actually achieved by means of a double-sided PWM converter joining the machine rotor to the grid. In order to decouple the active

Arantxa Tapia; Gerardo Tapia; J. Xabier Ostolaza; José Ramón Sáenz

2003-01-01

263

Can Machines BeCan Machines Be Polite?Polite?  

E-print Network

Can Machines BeCan Machines Be Polite?Polite? Michael A. CovingtonMichael A. Covington Artificial Intelligence CenterArtificial Intelligence Center #12;Can machines be polite?Can machines be polite? Machines have beenMachines have been annoying peopleannoying people ever since humanever since human--machine

Covington, Michael A.

264

Dynamic behavior of variable speed wind turbines under stochastic wind  

Microsoft Academic Search

It is recognized that the most important advantage of the variable speed wind turbines (VS WTs) over the conventional constant speed (CS) machines are the improved dynamic characteristics, resulting in the reduction of the drive train mechanical stresses and output power fluctuations. In this paper alternative configurations of the electrical part of a VS WT are considered, using a squirrel

S. A. Papathanassiou; M. P. Papadopoulos

1999-01-01

265

Sec. 2.5 Elasticity of cellular filaments 49 2.5 Elasticity of cellular filaments  

E-print Network

· length], the flexural rigidity of uniform rods can be written as a product of the Young's modulus Y deformation energy of a filament can be characterized by its flexural rigidity f. Having units of [energy

Boal, David

266

Filamentation control in the temperature gradient argon gas  

Microsoft Academic Search

A novel technique of controlling the evolution of the filamentation was experimentally demonstrated in an argon gas-filled\\u000a tube. The entrance of the filament was heated by a furnace and the other end was cooled with air, which resulted in the temperature\\u000a gradient distribution along the tube. The experimental results show that multiple filaments are merged into a single filament\\u000a and

S.-Y. Cao; W.-P. Kong; Z. Wang; Z.-M. Song; Y. Qin; R.-X. Li; Q.-Y. Wang; Z.-G. Zhang

2009-01-01

267

Hybrid Quantum Cloning Machine  

E-print Network

In this work, we introduce a special kind of quantum cloning machine called Hybrid quantum cloning machine. The introduced Hybrid quantum cloning machine or transformation is nothing but a combination of pre-existing quantum cloning transformations. In this sense it creates its own identity in the field of quantum cloners. Hybrid quantum cloning machine can be of two types: (i) State dependent and (ii) State independent or Universal. We study here the above two types of Hybrid quantum cloning machines. Later we will show that the state dependent hybrid quantum-cloning machine can be applied on only four input states. We will also find in this paper another asymmetric universal quantum cloning machine constructed from the combination of optimal universal B-H quantum cloning machine and universal anti-cloning machine. The fidelities of the two outputs are different and their values lie in the neighborhood of ${5/6} $

Satyabrata Adhikari; A. K. Pati; Indranil Chakrabarty; B. S. Choudhury

2007-05-04

268

The Origin of the Galactic Center Nonthermal Radio Filaments: Young Stellar Clusters  

NASA Astrophysics Data System (ADS)

The unusual class of magnetized nonthermal radio filaments, threads, and streaks, with their unique physical characteristics, is found only within the inner couple of degrees of the Galactic center. Also, a number of young, mass-losing, and rare stellar clusters are recognized as lying in the Galactic center region. The latter characteristic of the Galactic center region is used to explain the origin of the nonthermal radio filaments. We consider a mechanism in which the collective winds of massive W-R and OB stars within a dense stellar environment produce shock waves that can accelerate particles to relativistic energies. This mechanism is an extension of a model originally proposed in 1996 by Rosner & Bodo, who suggested that energetic nonthermal particles are produced in a terminal shock of mass-losing stars. The large-scale distribution of the magnetic field in the context of this model is argued to be neither poloidal in geometry nor pervasive throughout the Galactic center region.

Yusef-Zadeh, F.

2003-11-01

269

Variabilities detected by acoustic emission from filament-wound Aramid fiber/epoxy composite pressure vessels  

NASA Technical Reports Server (NTRS)

Two hundred and fifty Aramid fiber/epoxy pressure vessels were filament-wound over spherical aluminum mandrels under controlled conditions typical for advanced filament-winding. A random set of 30 vessels was proof-tested to 74% of the expected burst pressure; acoustic emission data were obtained during the proof test. A specially designed fixture was used to permit in situ calibration of the acoustic emission system for each vessel by the fracture of a 4-mm length of pencil lead (0.3 mm in diameter) which was in contact with the vessel. Acoustic emission signatures obtained during testing showed larger than expected variabilities in the mechanical damage done during the proof tests. To date, identification of the cause of these variabilities has not been determined.

Hamstad, M. A.

1978-01-01

270

Residual stress analysis in forming process of filament wound thick-walled CFRP pipes  

SciTech Connect

Residual stress analysis for the cracking phenomenon of filament would thick-walled CFRP pipes, which frequently occurs in the forming process of curing and thermal cycling through the course of the wet filament winding, was made from both the experimental and theoretical points of view. A simple analytical model to study the cracking in the CFRP pipes was proposed. The pipes are multilayered and reinforced in the axial and circumferential directions alternatively by carbon fibers. Taking account of the anisotropy of mechanical and thermal properties including the shrinkage strain, which depend considerably on the temperature, the residual stresses in the CFRP pipes were elucidated in the forming process, particularly, in cooling of the cure process.

Kondo, Toshimi [Nagaoka College of Technology (Japan). Dept. of Mechanical Engineering; Sekine, Hideki [Tohoku Univ., Sendai (Japan). Dept. of Aeronautics and Space Engineering; Nakano, Kunio [Japan Space Utilization Center, Tokyo (Japan)

1995-11-01

271

Wind turbine simulator based on DSEM  

Microsoft Academic Search

In this paper, a new type of wind turbine simulator (WTS) based on DSEM (doubly salient electro-magnetic machine) is proposed to simulate the steady-state and dynamic characteristics of a wind turbine in direct-driven DSEG (doubly salient electromagnetic generator) wind power generation system. A simple and effective torque control strategy is proposed to realize torque closed-loop control of DSEM which reproduces

Cheng Fangshun; Zhou Bo; Zhang Le

2009-01-01

272

Atomic model of a myosin filament in the relaxed state  

Microsoft Academic Search

Contraction of muscle involves the cyclic interaction of myosin heads on the thick filaments with actin subunits in the thin filaments(1). Muscles relax when this interaction is blocked by molecular switches on either or both filaments(2). Insight into the relaxed ( switched OFF) structure of myosin has come from electron microscopic studies of smooth muscle myosin molecules, which are regulated

John L. Woodhead; Fa-Qing Zhao; Roger Craig; Edward H. Egelman; Lorenzo Alamo; R. Padron

2005-01-01

273

Interaction of Actin Filaments with Microtubules Is Mediated by  

E-print Network

Interaction of Actin Filaments with Microtubules Is Mediated by Microtubule-Associated Proteins At the present time, the best evidence for interactions between actin filaments and microtubules comes from biophysical experiments with purified actin and microtubule proteins.'" In cells, actin filaments

274

Potential fields of merging and splitting filaments in air  

Microsoft Academic Search

Two interacting light filaments with different initial phases propagating in air are investigated numerically by using a ray tracing method. The evolution of the rays of a filament is governed by a potential field. During propagation, the two potential wells of the two filaments can merge into one or repel each other, depending on the initial phase difference between the

Yuan-Yuan Ma; Xin Lu; Ting-Ting Xi; Zuo-Qiang Hao; Qi-Huang Gong; Jie Zhang

2007-01-01

275

Solar Filament Material Oscillations and Drainage before Eruption  

NASA Astrophysics Data System (ADS)

Both large-amplitude longitudinal (LAL) oscillations and material drainage in a solar filament are associated with the flow of material along the filament axis, often followed by an eruption. However, the relationship between these two motions and a subsequent eruption event is poorly understood. We analyze a filament eruption using EUV imaging data captured by the Atmospheric Imaging Array on board the Solar Dynamics Observatory and the H? images from the Global Oscillation Network Group. Hours before the eruption, the filament was activated, with one of its legs undergoing a slow rising motion. The asymmetric activation inclined the filament relative to the solar surface. After the active phase, LAL oscillations were observed in the inclined filament. The oscillation period increased slightly over time, which may suggest that the magnetic fields supporting the filament evolve to be flatter during the slow rising phase. After the oscillations, a significant amount of filament material was drained toward one filament endpoint, followed immediately by the violent eruption of the filament. The material drainage may further support the change in magnetic topology prior to the eruption. Moreover, we suggest that the filament material drainage could play a role in the transition from a slow to a fast rise of the erupting filament.

Bi, Yi; Jiang, Yunchun; Yang, Jiayan; Hong, Junchao; Li, Haidong; Yang, Dan; Yang, Bo

2014-08-01

276

Motility and Chemotaxis of Filamentous Cells of Escherichia coli  

Microsoft Academic Search

Filamentous cells of Escherichia coli can be produced by treatment with the antibiotic cephalexin, which blocks cell division but allows cell growth. To explore the effect of cell size on chemotactic activity, we studied the motility and chemotaxis of filamentous cells. The filaments, up to 50 times the length of normal E. coli organisms, were motile and had flagella along

NAZLI MAKI; JASON E. GESTWICKI; ELLEN M. LAKE; LAURA L. KIESSLING; J. Adler

2000-01-01

277

Filaments in Orion: A first look of the Integral Shaped Filament with Herschel  

NASA Astrophysics Data System (ADS)

We present here the first maps of the Integral Shaped Filament in Orion A Molecular Cloud as mapped by the Herschel guaranteed time key program Gould Belt. The two tiles, mapped in parallel mode (PACS/SPIRE), are located just below the L1641N star forming region in the southern most regions of the Integral Shaped Filament. In this first study of the region we focus on the abundant filamentary structure apparent in the tiles. We have detected over 400 compact sources and derived their temperature distribution and the Core Mass Function (Msolar =~0.1~10s). We find that the spatial distribution of the identified sources follows closely the pattern of the filaments, strengthening arguments where filaments are the preferred location of star formation in molecular clouds. We have identified such filaments in the maps and derived their physical properties (i.e. column densities etc.). We will discuss here the relation between the physical properties of the sources and their parent filament.

Polychroni, D.

2012-01-01

278

Condition Monitoring of Wind Turbines: A Review  

E-print Network

ABSTRACT- This paper presents condition monitoring in wind turbines, and related technologies currently applied in practice and under development for aerospace applications, are reviewed. Condition monitoring system estimate the current condition of a machine from sensor measurements, whereas prediction systems give a probabilistic forecast of the future condition of the machine under the projected usage conditions. Current condition monitoring practice in wind turbine rotors involves tracking rotor imbalance, aerodynamic, surface roughness and overall performance and offline and online measurements of stress and strain. Key words- Wind energy, Condition monitoring 1.

Sachin Sharma; Dalgobind Mahto

279

Extreme Kicking Machine  

NSDL National Science Digital Library

In this design challenge activity follow up to "Kicking Machine", learners add a hands-free feature to their Kicking Machine. Learners modify their kicking machine to have it either release the pendulum or rubber band while standing three feet away or have it automatically feed balls into the kicking machine, one after another. They must figure out how to integrate the new feature into the existing structure and use the design process to make sure the modified kicking machine works properly. Educators can use this activity to demonstrate simple machines and kinetic/potential energy.

Wgbh

2010-01-01

280

Meteorology (Wind)  

Wind speed at 50 m (m/s) The average and percent difference minimum and ... are given.   Percent of time for ranges of wind speed at 50 m (percent) Percentage [frequency] of time that wind ... be adjusted to heights from 10 to 300 meters using the Gipe power law. Wind speeds may be adjusted for different terrain by selecting from ...

2014-09-25

281

Wind turbine optimal control during storms  

NASA Astrophysics Data System (ADS)

This paper proposes a control algorithm that enables wind turbine operation in high winds. With this objective, an online optimization procedure is formulated that, based on the wind turbine state, estimates those extremal wind speed variations that would produce maximal allowable wind turbine loads. Optimization results are compared to the actual wind speed and, if there is a danger of excessive loading, the wind turbine power reference is adjusted to ensure that loads stay within allowed limits. This way, the machine can operate safely even above the cut-out wind speed, thereby realizing a soft envelope-protecting cut-out. The proposed control strategy is tested and verified using a high-fidelity aeroservoelastic simulation model.

Petrovi?, V.; Bottasso, C. L.

2014-06-01

282

Machine Learning for Global Optimization  

E-print Network

global optimization, machine learning, support vector machines, space trajectory design. Introduction ...... LIBSVM: a library for support vector machines. (Software ... Boston, Dordrecht, London: Kluwer Academic Publishers. Mangasarian, O. L. ...

schoen,,,

283

Interactive Gumball Machine  

NSDL National Science Digital Library

In this activity, learners review the history of gumball machines and explore potential and kinetic energy, while working in teams to build a gumball slide. Teams then design and build their own interactive gumball machine.

Ieee

2013-08-30

284

Feasibility of utilizing wind energy in Thailand  

SciTech Connect

The purpose of this study was to ascertain the feasibility of utilizing wind energy to meet part of the energy demands related to pumping water and to generating electricity for the rural households in Thailand. The data for this study were divided into three different areas: (1) wind speed data, (2) the wind machine performance data, and (3) the rural energy demand data. The wind machine were divided into two categories of water-pumping windmills and electricity-generating wind machines. Three types of water pumping windmills and one type of electricity-generating wind machine were matched with the wind condition in Thailand. They were the multi-blade rotor, the sailwing rotor model (WE 002), the slow-speed sailwing rotor, and the Aerowatt model (1100 FP5G) respectively. It was concluded that, in Thailand: (1) the multiblade rotor and the sail-wing rotor (WE 002) windmill is suitable for pumping water for domestic use at 43 specified locations; (2) the slow-speed sailwing rotor windmill is suitable for pumping water for small irrigation at 32 specified locations; and (3) the Aerowatt model (1100 GP5G) is suitable for generating electricity for household use at 29 specified locations.

Jamkrajang, M.

1984-01-01

285

Enertech 2-kW high-reliability wind system. Phase II. Fabrication and testing  

SciTech Connect

A high-reliability wind machine rated for 2 kW in a 9 m/s wind has been developed. Activities are summarized that are centered on the fabrication and testing of prototypes of the wind machine. The test results verified that the wind machine met the power output specification and that the variable-pitch rotor effectively controlled the rotor speed for wind speeds up to 50 mph. Three prototypes of the wind machine were shipped to the Rocky Flats test center in September through November of 1979. Work was also performed to reduce the start-up wind speed. The start-up wind speed to the Enertech facility has been reduced to 4.5 m/s.

Cordes, J A; Johnson, B A

1981-06-01

286

Properties of Magnetic Neutral Lines and Filament Formation  

NASA Astrophysics Data System (ADS)

Chromospheric filaments form at a boundary (neutral lines) between opposite polarity magnetic fields. Both the total length of neutral lines and the number of filaments vary with solar cycle. However, our analysis indicates that the cycle variation in filaments is not due to the change in the total length of neutral lines. It is likely due to change in magnetic properties of neutral lines. In present study we compare properties of magnetic polarity inversion lines that have filaments above them and those without filaments, and investigate how these properties change during the solar cycle. Our results show that the gradient as well as convergence/divergence of magnetic field across neutral lines are not the major factors that determine the places of filament formation. We discuss the role of canceling magnetic features in filament formation and their cycle variation.

Karachik, N.; Pevtsov, A. A.

2011-12-01

287

Your Sewing Machine.  

ERIC Educational Resources Information Center

The programed instruction manual is designed to aid the student in learning the parts, uses, and operation of the sewing machine. Drawings of sewing machine parts are presented, and space is provided for the student's written responses. Following an introductory section identifying sewing machine parts, the manual deals with each part and its…

Peacock, Marion E.

288

Talking Vending Machines  

E-print Network

're in the central Tokyo Station and you're thirsty so you go to the, you know, vending machine to buy a drink. Only this is not your average vending machine. Uh uh. This vending machine has opinions on what beverage you want. Sensors built into large touch panels...

Hacker, Randi

2011-02-02

289

Cable-Twisting Machine  

NASA Technical Reports Server (NTRS)

New cable-twisting machine is smaller and faster than many production units. Is useful mainly in production of short-run special cables. Already-twisted cable can be fed along axis of machine. Faster operation than typical industrial cable-twisting machines possible by using smaller spools of wire.

Kurnett, S.

1982-01-01

290

Morphogenesis of filaments growing in flexible confinements  

E-print Network

Space-saving design is a requirement that is encountered in biological systems and the development of modern technological devices alike. Many living organisms dynamically pack their polymer chains, filaments or membranes inside of deformable vesicles or soft tissue like cell walls, chorions, and buds. Surprisingly little is known about morphogenesis due to growth in flexible confinements - perhaps owing to the daunting complexity lying in the nonlinear feedback between packed material and expandable cavity. Here we show by experiments and simulations how geometric and material properties lead to a plethora of morphologies when elastic filaments are growing far beyond the equilibrium size of a flexible thin sheet they are confined in. Depending on friction, sheet flexibility and thickness, we identify four distinct morphological phases emerging from bifurcation and present the corresponding phase diagram. Four order parameters quantifying the transitions between these phases are proposed.

Roman Vetter; Falk K. Wittel; Hans J. Herrmann

2014-07-17

291

Morphogenesis of filaments growing in flexible confinements  

E-print Network

Space-saving design is a requirement that is encountered in biological systems and the development of modern technological devices alike. Many living organisms dynamically pack their polymer chains, filaments or membranes inside of deformable vesicles or soft tissue like cell walls, chorions, and buds. Surprisingly little is known about morphogenesis due to growth in flexible confinements - perhaps owing to the daunting complexity lying in the nonlinear feedback between packed material and expandable cavity. Here we show by experiments and simulations how geometric and material properties lead to a plethora of morphologies when elastic filaments are growing far beyond the equilibrium size of a flexible thin sheet they are confined in. Depending on friction, sheet flexibility and thickness, we identify four distinct morphological phases emerging from bifurcation and present the corresponding phase diagram. Four order parameters quantifying the transitions between these phases are proposed.

Vetter, Roman; Herrmann, Hans J

2014-01-01

292

Solar Magnetized "Tornadoes": Relation to Filaments  

E-print Network

Solar magnetized "tornadoes", a phenomenon discovered in the solar atmosphere, appear as tornado-like structures in the corona but root in the photosphere. Like other solar phenomena, solar tornadoes are a feature of magnetized plasma and therefore differ distinctly from terrestrial tornadoes. Here we report the first analysis of solar "tornadoes" {Two papers which focused on different aspect of solar tornadoes were published in the Astrophysical Journal Letters (Li et al. 2012) and Nature (Wedemeyer-B\\"ohm et al. 2012), respectively, during the revision of this Letter.}. A detailed case study of two events indicates that they are rotating vertical magnetic structures probably driven by underlying vortex flows in the photosphere. They usually exist as a group and relate to filaments/prominences, another important solar phenomenon whose formation and eruption are still mysteries. Solar tornadoes may play a distinct role in the supply of mass and twists to filaments. These findings could lead to a new explanati...

Su, Yang; Veronig, Astrid; Temmer, Manuela; Gan, Weiqun

2012-01-01

293

Online Catalog for Filament-Sigmoid Correlation  

NASA Astrophysics Data System (ADS)

A new online catalog correlating H-alpha filaments with SXT sigmoids gives researchers, teachers and pre-college students the ability to access digital H-alpha images online that were previously available only at the physical location of the NSO at Sunspot, NM. This web-based catalog correlates SOHO's SXT sigmoids from 1993-1998 as described in a non-online catalog created by Zach Blehm under the direction of Richard Canfield, MSU-Bozeman, with H-alpha filament activity as described by Ivy Merriot under the direction of Alexei Pevtsov, NSO, and Petrus Martens, MSU-Bozeman. The H-alpha images were digitized from film archives of the Flare Patrol Telescope at Sunspot, NM. Use of the online catalog will be demonstrated at the poster site with critical comments encouraged.

Merriot, Ivy; Pevtsov, A.; Martens, P.

2007-05-01

294

Influence of multiple ionization in laser filamentation  

NASA Astrophysics Data System (ADS)

Laser filaments in gases result from the nonlinear balance between optical Kerr self-focusing and plasma generation in the single ionization limit, i.e., the pulse intensity is supposed to remain moderate enough (? {{10}14} W cm?2) to apply photo-ionization theories valid for an averaged ion charge less than unity. However, no theory has attempted so far to consider how an ionization model allowing a priori multiple-charged states could impact the standard filamentation scenario. Here, we discuss a multiple photo-ionization scheme that relies on probabilities assuming successive single-electron ionizations. We numerically show that a multiple ionization scheme can increase the clamping intensity, the peak electron density and supercontinuum generation in gases with high binding energy, e.g., helium.

González de Alaiza Martínez, P.; Bergé, L.

2014-10-01

295

Antibody to intermediate filaments of the cytoskeleton.  

PubMed Central

IgM antibodies against cultures of intermediate filaments (IMF) of the cytoskeleton were demonstrated by immunofluorescence in the sera of 94 (80%) of 118 patients with seropositive rheumatoid arthritis. These antibodies reacted with IMF in cultures of both human fetal fibroblasts and laryngeal carcinoma (HEp2) cells. Of 10 patients from whom paired synovial fluids were also available 8 had anti-IMF antibodies in both serum and fluid. In seronegative RA the incidence of anti-IMF was 40%, in ankylosing spondylitis 25%, in osteoarthrosis 16%, and in normal subjects 14%. Only a minority of RA sera positive for anti-IMF antibodies were also positive for smooth muscle antibody. Absorption experiments suggest that in RA anti-IMF is directed at the intermediate filament protein, vimentin. Images PMID:7039524

Osung, O A; Chandra, M; Holborow, E J

1982-01-01

296

Morphogenesis of filaments growing in flexible confinements.  

PubMed

Space-saving design is a requirement that is encountered in biological systems and the development of modern technological devices alike. Many living organisms dynamically pack their polymer chains, filaments or membranes inside deformable vesicles or soft tissue-like cell walls, chorions and buds. Surprisingly little is known about morphogenesis due to growth in flexible confinements--perhaps owing to the daunting complexity lying in the nonlinear feedback between packed material and expandable cavity. Here we show by experiments and simulations how geometric and material properties lead to a plethora of morphologies when elastic filaments are growing far beyond the equilibrium size of a flexible thin sheet they are confined in. Depending on friction, sheet flexibility and thickness, we identify four distinct morphological phases emerging from bifurcation and present the corresponding phase diagram. Four order parameters quantifying the transitions between these phases are proposed. PMID:25026967

Vetter, R; Wittel, F K; Herrmann, H J

2014-01-01

297

Impact damage in filament wound composite bottles  

NASA Technical Reports Server (NTRS)

Increasingly, composite materials are being used in advanced structural applications because of the significant weight savings they offer when compared to more traditional engineering materials. The higher cost of composites must be offset by the increased performance that results from reduced structural weight if these new materials are to be used effectively. At present, there is considerable interest in fabricating solid rocket motor cases out of composite materials, and capitalizing on the reduced structural weight to increase rocket performance. However, one of the difficulties that arises when composite materials are used is that composites can develop significant amounts of internal damage during low velocity impacts. Such low velocity impacts may be encountered in routine handling of a structural component like a rocket motor case. The ability to assess the reduction in structural integrity of composite motor cases that experience accidental impacts is essential if composite rocket motor cases are to be certified for manned flight. While experimental studies of the post-impact performance of filament wound composite motor cases haven been proven performed (2,3), scaling impact data from small specimens to full scale structures has proven difficult. If such a scaling methodology is to be achieved, an increased understanding of the damage processes which influence residual strength is required. The study described herein was part of an ongoing investigation of damage development and reduction of tensile strength in filament wound composites subjected to low velocity impacts. The present study, which focused on documenting the damage that develops in filament wound composites as a result of such impacts, included two distinct tasks. The first task was to experimentally assess impact damage in small, filament wound pressure bottles using x-ray radiography. The second task was to study the feasibility of using digital image processing techniques to assist in determining the 3-D distribution of damage from stereo x-ray pairs.

Highsmith, Alton L.

1993-01-01

298

Continuous-Filament Isogrid Composite Panel  

NASA Technical Reports Server (NTRS)

Damaged panels do not fail catastrophically when fabricated this way. Isogrid stiffener formed in slotted silicon-rubber tool. At grid intersections, slots offset to prevent excessive buildup of composite material and widened to give room for overlapping filaments to spread when compressed. Following total failure of skin, isogrid stiffener still carries 350 kN/m (2,000 1b/in.) and remains intact.

Williams, J. G.; Palmer, R. J.; Tucci, A. T.

1985-01-01

299

Kinetics of Filamentous Growth and Branching  

Microsoft Academic Search

Both Chapters 14 and 15 are concerned with quantification of fungal growth and morphology. This is frequently necessary for\\u000a purely practical or technical reasons. For example, many physiological studies require information on the specific rate of\\u000a growth or biomass yield. Similarly, large-scale industrial fermentations involving filamentous fungi can only be operated\\u000a and controlled efficiently on the basis of quantitative information

J. I. Prosser

300

White-Light Filaments for Atmospheric Analysis  

Microsoft Academic Search

Most long-path remote spectroscopic studies of the atmosphere rely on ambient light or narrow-band lasers. High-power femtosecond laser pulses have been found to propagate in the atmosphere as dynamically self-guided filaments that emit in a continuum from the ultraviolet to the infrared. This white light exhibits a directional behavior with enhanced backward scattering and was detected from an altitude of

J. Kasparian; M. Rodriguez; G. Méjean; J. Yu; E. Salmon; H. Wille; R. Bourayou; S. Frey; Y.-B. André; A. Mysyrowicz; R. Sauerbrey; J.-P. Wolf; L. Wöste

2003-01-01

301

Stator for Rotating Electrical Machine Having Multiple Controlwindings  

SciTech Connect

A rotating electric machine is provided which includes multiple independent control windings for compensating for rotor imbalances and for levitating/centering the rotor. The multiple independent control windings are placed at different axial locations along the rotor to oppose forces created by imbalances at different axial locations along the rotor. The multiple control windings can also be used to levitate/center the rotor with a relatively small magnetic field per unit area since the rotor and/or the main power winding provides the biasfield.

Shah, Manoj R.; Lewandowski, Chad R.

1999-05-05

302

Hot filament CVD of boron nitride films  

DOEpatents

Using a hot filament (.apprxeq.1400.degree. C.) to activate borazine (B.sub.3 N.sub.3 H.sub.6) molecules for subsequent reaction with a direct line-of-sight substrate, transparent boron ntiride films as thick as 25,000 angstroms are grown for a substrate temperature as low as 100.degree. C. The minimum temperature is determined by radiative heating from the adjacent hot filament. The low temperature BN films show no indication of crystallinity with X-ray diffraction (XRD). X-ray photoelectron spectra (XPS) show the films to have a B:N ratio of 0.97:1 with no other XPS detectable impurities above the 0.5% level. Both Raman and infrared (IR) spectroscopy are characteristic of h-BN with small amounts of hydrogen detected as N-H and B-H bands in the IR spectrum. An important feature of this method is the separation and localization of the thermal activation step at the hot filament from the surface reaction and film growth steps at the substrate surface. This allows both higher temperature thermal activation and lower temperature film growth.

Rye, Robert R. (Albuquerque, NM)

1992-01-01

303

Power in the wind. [Techniques for estimation of wind potential energy  

SciTech Connect

Techniques are described which can be used by engineers, technicians and homeowners for the estimation of potential energy in wind and in particular wind machines. They are suitable for onsite calculations with the use of nothing more than a pocket calculator. (JMT)

Gipe, P.

1981-04-01

304

Circular tests for HSM machine tools: Bore machining application  

Microsoft Academic Search

Today's High-Speed Machining (HSM) machine tool combines productivity and part quality. The difficulty inherent in HSM operations lies in understanding the impact of machine tool behaviour on machining time and part quality. Analysis of some of the relevant ISO standards [230. Acceptance code for machine tools. Part 4, Circular tests for numerically controlled machine-tools, April 1998, 10791. Test conditions for

Laurent Tapie; Kwamiwi Mawussi; Bernard Anselmetti

2007-01-01

305

What is Machine Learning? About the Course Example Machine Learning  

E-print Network

What is Machine Learning? About the Course Example Machine Learning DD2431 ¨Orjan Ekeberg Oct­Dec, 2008 #12;What is Machine Learning? About the Course Example 1 What is Machine Learning? Definition A Hypothetical Project #12;What is Machine Learning? About the Course Example 1 What is Machine Learning

Kjellström, Hedvig

306

What is Machine Learning? About the Course Example Machine Learning  

E-print Network

What is Machine Learning? About the Course Example Machine Learning DD2431 ¨Orjan Ekeberg Oct­Dec, 2007 What is Machine Learning? About the Course Example 1 What is Machine Learning? Definition A Hypothetical Project What is Machine Learning? About the Course Example 1 What is Machine Learning? Definition

Kjellström, Hedvig

307

What is Machine Learning? About the Course Example Machine Learning  

E-print Network

What is Machine Learning? About the Course Example Machine Learning DD2431 ¨Orjan Ekeberg Oct­Dec, 2008 What is Machine Learning? About the Course Example 1 What is Machine Learning? Definition A Hypothetical Project What is Machine Learning? About the Course Example 1 What is Machine Learning? Definition

Kjellström, Hedvig

308

What is Machine Learning? About the Course Example Machine Learning  

E-print Network

What is Machine Learning? About the Course Example Machine Learning DD2431 ¨Orjan Ekeberg Oct­Dec, 2007 #12;What is Machine Learning? About the Course Example 1 What is Machine Learning? Definition A Hypothetical Project #12;What is Machine Learning? About the Course Example 1 What is Machine Learning

Kjellström, Hedvig

309

Benchmarking the Connection Machine  

SciTech Connect

The purpose of this memo is to present the results of work done recently on the Connection Machine during a one-week visit by the authors to Thinking Machines Corporation. The main objectives of the trip were to benchmark the Connection Machine and to assess the software environment, in order to determine the suitability of the Connection Machine for solving computationally-intensive problems and to compare the Connection Machine with other highly-parallel computers. This report presents preliminary results, and describes the computer architecture.

Baillie, C.; Felten, E.; Walker, D.

1987-01-01

310

Edheads: The Compound Machine  

NSDL National Science Digital Library

This resource is a collection of interactive animations designed to help kids learn how forces and simple machines can work together to create the compound machine. Child-centered animated activities enhance understanding of how compound machines function and how they are differentiated from simple machines. Additionally the site includes a glossary of important terms, lesson plans, a teacher's guide and information about professionals who work with compound machines. This page is part of a larger collection of animated education resources for the elementary level.

2007-09-18

311

The fault diagnosis of large-scale wind turbine based on expert system  

Microsoft Academic Search

The wind turbine is the critical equipment for wind power, due to the poor working environment and the long running, the wind turbine components will have a variety of failures. Planned maintenance which has long been used is unable to understand the operational status of equipment comprehensively and timely in a way, especially for large wind machine, the repair work

Changzheng Chen; Yun Li

2011-01-01

312

Energetic particle evidence for magnetic filaments in Jupiter's magnetotail  

NASA Astrophysics Data System (ADS)

Jupiter's immense magnetotail was uniquely traversed and observed in situ to 2562 Jovian radii (RJ = 71,492 km) for the first time by the Pluto-bound New Horizons spacecraft during the first half of 2007. We show evidence that energetic ions with sulfur-rich composition traceable to Io's volcanism originated 150 ± 40 RJ antisunward of the planet and were recurrently released and funneled by the magnetic field down the magnetotail. Ions detected at New Horizons by the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument showed unmistakable signatures of velocity dispersion. We performed a survey of the unambiguous dispersion events observed by PEPSSI and provide a quantitative description of each event's dispersion characteristics. Energetic ions are sensitive probes of the magnetic field structure in the magnetotail; so, for a case study of one of the most interesting events, beginning on day of year 118, 28 April 2007, we are also able to estimate small-scale features of the magnetotail. Our observations (which include energies above ˜2 keV/nuc and total energies below ˜1 MeV), combined with straightforward simulations of particle flow, are consistent with narrow spatial structures, or filaments, on the order of 5 RJ wide in the ˜400 RJ wide > 9000 RJ long magnetotail; the Solar Wind Around Pluto plasma instrument measurements show coherent structures on a much larger scale (˜500 RJ) in the same region.

Hill, Matthew E.; Haggerty, Dennis K.; McNutt, Ralph L.; Paranicas, Christopher P.

2009-11-01

313

Residual and fracture strains of Bi2223 filaments and their relation to critical current under applied bending and tensile strains in Bi2223\\/Ag\\/Ag alloy composite superconductor  

Microsoft Academic Search

Mechanical and electromagnetic stresses are exerted on Bi2223\\/Ag\\/Ag alloy superconducting composite tapes during fabrication\\/winding and operation, which cause reduction in critical current when the Bi2223 filaments are damaged. In the damage process, the thermally induced residual strain and fracture strain of the Bi2223 filaments play a dominant role. The aim of the present work was to propose a comprehensive method

S. Ochiai; J. K. Shin; S. Iwamoto; H. Okuda; S. S. Oh; D. W. Ha; M. Sato

2008-01-01

314

Filamentation in argon microwave plasma at atmospheric pressure  

SciTech Connect

Filamentation in an argon plasma is studied using a microwave cavity at atmospheric pressure. We show that the size and gas temperature of the filaments increase with the power absorbed by the plasma. The appearance of an additional filament occurs at specific values of the absorbed power. Each new filament appears with a smaller diameter than that of its parent filament but the sum of the diameters of all filaments evolves linearly with the absorbed power. A secondary filament emerges from a set of microfilaments created by a perturbation of the electric field (a slight increase in the incident power above a threshold value). This perturbation occurs over a larger radius than that of the parent filament. By resorting to modeling, we found that the filamentation process involves either a decrease in the effective frequency for momentum-transfer collisions, i.e., a lower electron temperature, or an increase in the electron density. We could show that a small change in the relative positions occupied by two filaments in the microwave cavity requires a strong variation in the electron temperature.

Cardoso, R. P.; Belmonte, T.; Noeel, C.; Kosior, F.; Henrion, G. [Departement CP2S, CNRS, Institut Jean Lamour, Nancy-Universite, UPV-Metz, Parc de Saurupt, CS 14234, 54042 Nancy Cedex (France)

2009-05-01

315

Atomic force microscopy of thermally treated myosin filaments.  

PubMed

Heat-induced morphological change in myosin filaments was observed using atomic force microscope. The thickness of fixed native myosin filament was estimated to be 95 +/- 5 nm. When myosin filaments in 0.1 M NaCl at pH 6.0 were heated at 40, 55, and 70 degrees C for 10 min, the particulate structure appeared spirally on the surface of the filament at 40 degrees C, and the thickness of the filament was 75 +/- 10 nm. When myosin filaments were treated at 55 degrees C, several filaments were formed associated with side-by-side interaction through projected myosin heads to form a strand. The surface of the strand looked knobby. The thickness of thermally denatured filaments at 55 degrees C was 48 +/- 5 nm, and that of strands was about 80-110 nm, indicating the involvement of several filaments in a strand. The strands became to be rope-like at 70 degrees C, and the individual filaments in a strand were not distinguishable. PMID:15913330

Iwasaki, Tomohito; Washio, Masahiro; Yamamoto, Katsuhiro

2005-06-01

316

Geometry of flexible filament cohesion: Better contact through twist?  

E-print Network

Cohesive interactions between filamentous molecules have broad implications for a range of biological and synthetic materials. While long-standing theoretical approaches have addressed the problem of inter-filament forces from the limit of infinitely rigid rods, the ability of flexible filaments to deform intra-filament shape in response to changes in inter-filament geometry has a profound affect on the nature of cohesive interactions. In this paper, we study two theoretical models of inter-filament cohesion in the opposite limit, in which filaments are sufficiently flexible to maintain cohesive contact along their contours, and address, in particular, the role played by helical-interfilament geometry in defining interactions. Specifically, we study models of featureless, tubular filaments interacting via 1) pair-wise Lennard-Jones (LJ) interactions between surface elements and 2) depletion-induced filament binding stabilized by electrostatic surface repulsion. Analysis of these models reveals a universal preference for cohesive filament interactions for non-zero helical skew, and further, that in the asymptotic limit of vanishing interaction range relative to filament diameter, the skew-dependence of cohesion approaches a geometrically defined limit described purely by the close-packing geometry of twisted tubular filaments. We further analyze non-universal features of the skew-dependence of cohesion at small-twist for both potentials, and argue that in the LJ model the pair-wise surface attraction generically destabilizes parallel filaments, while in the second model, pair-wise electrostatic repulsion in combination with non-pairwise additivity of depletion leads to a meta-stable parallel state.

Luis Cajamarca; Gregory M. Grason

2014-07-16

317

Perspex machine: VII. The universal perspex machine  

NASA Astrophysics Data System (ADS)

The perspex machine arose from the unification of projective geometry with the Turing machine. It uses a total arithmetic, called transreal arithmetic, that contains real arithmetic and allows division by zero. Transreal arithmetic is redefined here. The new arithmetic has both a positive and a negative infinity which lie at the extremes of the number line, and a number nullity that lies off the number line. We prove that nullity, 0/0, is a number. Hence a number may have one of four signs: negative, zero, positive, or nullity. It is, therefore, impossible to encode the sign of a number in one bit, as floating-point arithmetic attempts to do, resulting in the difficulty of having both positive and negative zeros and NaNs. Transrational arithmetic is consistent with Cantor arithmetic. In an extension to real arithmetic, the product of zero, an infinity, or nullity with its reciprocal is nullity, not unity. This avoids the usual contradictions that follow from allowing division by zero. Transreal arithmetic has a fixed algebraic structure and does not admit options as IEEE, floating-point arithmetic does. Most significantly, nullity has a simple semantics that is related to zero. Zero means "no value" and nullity means "no information." We argue that nullity is as useful to a manufactured computer as zero is to a human computer. The perspex machine is intended to offer one solution to the mind-body problem by showing how the computable aspects of mind and, perhaps, the whole of mind relates to the geometrical aspects of body and, perhaps, the whole of body. We review some of Turing's writings and show that he held the view that his machine has spatial properties. In particular, that it has the property of being a 7D lattice of compact spaces. Thus, we read Turing as believing that his machine relates computation to geometrical bodies. We simplify the perspex machine by substituting an augmented Euclidean geometry for projective geometry. This leads to a general-linear perspex-machine which is very much easier to program than the original perspex-machine. We then show how to map the whole of perspex space into a unit cube. This allows us to construct a fractal of perspex machines with the cardinality of a real-numbered line or space. This fractal is the universal perspex machine. It can solve, in unit time, the halting problem for itself and for all perspex machines instantiated in real-numbered space, including all Turing machines. We cite an experiment that has been proposed to test the physical reality of the perspex machine's model of time, but we make no claim that the physical universe works this way or that it has the cardinality of the perspex machine. We leave it that the perspex machine provides an upper bound on the computational properties of physical things, including manufactured computers and biological organisms, that have a cardinality no greater than the real-number line.

Anderson, James A. D. W.

2006-01-01

318

Machine Learning Group Machine Learning Group Machine Learning Group  

E-print Network

The deep Boltzmann machine is a powerful model that extracts the hierarchical structure of observed data. While inference is typically slow due to its undirected nature, we argue that the emerging feature hierarchy is still explicit enough to be traversed in a feedforward fashion. The claim is corroborated by training a set of deep neural networks on real data and measuring the evolution of the representation layer after layer. The analysis reveals that the deep Boltzmann machine produces a feed-forward hierarchy of increasingly invariant representations that clearly surpasses the layer-wise approach. 1

Grégoire Montavon; Mikio L. Braun; Klaus-robert Müller; Tu Berlin; Tu Berlin; Tu Berlin

319

Filaments of Forming Star Cluster Complexes in the Heart of NGC~1808  

NASA Astrophysics Data System (ADS)

We present new ESO/VLT/SINFONI data of the central starburst region of NGC~1808. We highlight the detection of chaplets of embedded clusters forming along filaments of gas circling around the nucleus. The embedded clusters are detected as Br_gamma sources and have no K-band counterpart. The kinematic maps reveal an inward radial velocity component for the gas, which is more pronounced than that for the stars. This suggests a scenario in which clusters are formed in inward spiraling filaments of gas which are locally illuminated by the young massive clusters. After 4-8 Myr, the clusters, following the stellar kinematic pattern, drift away from the gas filaments and become detectable in the K-band. This mechanism may complement gas expulsion by winds and supernovae for explaining the transition from embedded to non-embedded state, and may be especially important in dense environments such as those observed in the central starburst region of barred spiral galaxies.

Galliano, E.; Kissler-Patig, M.; Tacconi-Garmann, L.; Alloin, D.

2014-09-01

320

A filament of energetic particles near the high-latitude dawn magnetopause  

NASA Technical Reports Server (NTRS)

The Geotail satelite detected a filament of tailward-streaming energetic particles spatially separated from the boundary layer of energetic particles at the high-latitude dawn magnetopause at a downstream distance of approximately 80 R(sub E) on October 27, 1992. During this event, the composition and charge states of energetic ions at energies above approximately 10 keV show significant intermix of ions from solar wind and ionospheric sources. Detailed analysis leads to the deduction that the filament was moving southward towards the neutral sheet at an average speed of approximately 80 km/s, implying an average duskward electric field of approximately 1 mV/m. Its north-south dimension was approximately 1 R(sub E) and it was associated with an earthward directed field-aligned current of approximately 5 mA/m. The filament was separated from the energetic particle boundary layer straddling the magnetopause by approximately 0.8 R(sub E) and was inferred to be detached from the boundary layer at downstream distance beyond approximately 70 R(sub E) in the distant tail.

Lui, A. T. Y.; Williams, D. J.; Mcentire, R. W.; Christon, S. P.; Jacquey, C.; Angelopoulos, V.; Yamamoto, T.; Kokubun, S.; Frank, L. A.; Ackerson, K. L.

1994-01-01

321

Wind Whispers  

NSDL National Science Digital Library

The Advanced Technology Environmental and Energy Center (ATEEC) provides this presentation on the career and technical aspects of wind energy. In addition to discussing careers in wind, the presentation covers the siting of wind turbines and some electricity basics. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

2011-03-09

322

Toasty Wind  

NSDL National Science Digital Library

In this quick activity, learners use a toaster to investigate the source for the Earth's wind. Learners hold a pinwheel above a toaster to discover that rising heat causes wind. Use this activity to introduce learners to the process of convection as a source for wind. This resource also explains how convection causes thunderstorms and lists important thunderstorm safety tips.

Service, National W.

2012-07-24

323

Force generation by a parallel array of actin filaments  

E-print Network

We develop a model to describe the force generated by an array of well- separated parallel biofilaments, such as actin filaments. The filaments are assumed to only be coupled through mechanical contact with a movable barrier. We calculate the filament density distribution and the force-velocity relation with a mean-field approach combined with simulations. We identify two regimes: a non-condensed regime at low force in which filaments are spread out spatially, and a condensed regime at high force in which filaments accumulate near the barrier. We confirm that in this model, the stall force is equal to N times the stall force of a single filament. However, surprisingly, for large N, we find that the velocity approaches zero at forces significantly lower than the stall force.

Tsekouras, K; Mallick, K; Joanny, J -F

2011-01-01

324

Filamentation Instability of Counterpropagating Charged Particle Beams: Statistical Properties  

SciTech Connect

The filamentation instability (FI) driven by beams of counter-propagating electrons is examined with one-dimensional (1D) and two-dimensional (2D) particle-in-cell (PIC) simulations. The 1D simulation reveals the saturation mechanism of the FI. The magnetic pressure gradient displaces the electrons. The resulting electrostatic field inhibits together with the magnetic field a further growth of the filaments by suppressing the electron motion. The FI evolves into a stationary equilibrium in 1D, which shows a statistical distribution of the filament sizes that resembles a Gumbel distribution. The 2D PIC simulation allows the filaments to move around each other and filaments carrying currents of equal polarity can merge. The time-evolution of the characteristic size of the filaments in the 2D simulation is measured. It increases linearly with the time.

Dieckmann, M. E. [Centre for Plasma Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Department of Science and Technology (ITN), Linkoping University, Campus Norrkoping, SE-60174 Norrkoping (Sweden)

2008-10-15

325

A FILAMENT ERUPTION ON 2010 OCTOBER 21 FROM THREE VIEWPOINTS  

SciTech Connect

A filament eruption on 2010 October 21 observed from three different viewpoints by the Solar Terrestrial Relations Observatory and the Solar Dynamic Observatory is analyzed by also invoking data from the Solar and Heliospheric Observatory and the Kanzelhoehe Solar Observatory. The position of the filament just before the eruption at the central meridian not far from the center of the solar disk was favorable for photospheric magnetic field measurements in the area below the filament. Because of this, we were able to calculate with high precision the distribution of the coronal potential magnetic field near the filament. We found that the filament began to erupt when it approached the height in the corona where the magnetic field decay index was greater than 1. We also determined that during the initial stage of the eruption the filament moved along the magnetic neutral surface.

Filippov, Boris, E-mail: bfilip@izmiran.ru [Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences (IZMIRAN), Troitsk, Moscow 142190 (Russian Federation)

2013-08-10

326

Microwave guiding in air along single femtosecond laser filament  

NASA Astrophysics Data System (ADS)

Microwave guiding along single plasma filament generated through the propagation of femtosecond (fs) laser pulses in air has been demonstrated over a distance of about 6.5 cm, corresponding to a microwave signal intensity enhancement of more than 3-fold over free space propagation. The current propagation distance along the fs laser filament is in agreement with the calculations and limited by the relatively high resistance of the single plasma filament. Using a single fs laser filament to channel microwave radiation considerably alleviate requirements to the power of fs laser pulses compared to the case of the circular filaments waveguide. In addition, it can be used as a simple and non-intrusive method to obtain the basic parameters of laser-generated plasma filament.

Ren, Yu; Alshershby, Mostafa; Qin, Jiang; Hao, Zuoqiang; Lin, Jingquan

2013-03-01

327

Envelope structure of four gliding filamentous cyanobacteria.  

PubMed Central

The cell walls of four gliding filamentous Oscillatoriaceae species comprising three different genera were studied by freeze substitution, freeze fracturing, and negative staining. In all species, the multilayered gram-negative cell wall is covered with a complex external double layer. The first layer is a tetragonal crystalline S-layer anchored on the outer membrane. The second array is formed by parallel, helically arranged surface fibrils with diameters of 8 to 12 nm. These fibrils have a serrated appearance in cross sections. In all cases, the orientation of the surface fibrils correlates with the sense of revolution of the filaments during gliding, i.e., clockwise in both Phormidium strains and counterclockwise in Oscillatoria princeps and Lyngbya aeruginosa. The lack of longitudinal corrugations or contractions of the surface fibrils and the identical appearances of motile and nonmotile filaments suggest that this structure plays a passive screw thread role in gliding. It is hypothesized that the necessary propulsive force is generated by shear forces between the surface fibrils and the continuing flow of secreted extracellular slime. Furthermore, the so-called junctional pores seem to be the extrusion sites of the slime. In motile cells, these pores exhibit a different staining behavior than that seen in nonmotile ones. In the former, the channels of the pores are filled with electron-dense material, whereas in the latter, the channels appear comparatively empty, highly contrasting the peptidoglycan. Finally, the presence of regular surface structures in other gliding prokaryotes is considered an indication that comparable structures are general features of the cell walls of gliding microbes. PMID:7730269

Hoiczyk, E; Baumeister, W

1995-01-01

328

The sawing machine is a machine SAWING MACHINES  

E-print Network

main parts, which are discussed below. The head is the large unit at the top of the contour machine), and the adjustable post which supports the upper saw guide. The job selector dial is also located on the head the speed in feet per minute (FPM). The butt welder is also mounted on the column. different positions

Gellman, Andrew J.

329

Machine tool locator  

DOEpatents

Machine tools can be accurately measured and positioned on manufacturing machines within very small tolerances by use of an autocollimator on a 3-axis mount on a manufacturing machine and positioned so as to focus on a reference tooling ball or a machine tool, a digital camera connected to the viewing end of the autocollimator, and a marker and measure generator for receiving digital images from the camera, then displaying or measuring distances between the projection reticle and the reference reticle on the monitoring screen, and relating the distances to the actual position of the autocollimator relative to the reference tooling ball. The images and measurements are used to set the position of the machine tool and to measure the size and shape of the machine tool tip, and examine cutting edge wear. patent

Hanlon, John A. (Los Alamos, NM); Gill, Timothy J. (Stanley, NM)

2001-01-01

330

Plasma planar filament instability and Alfven waves  

E-print Network

Inhomogeneous plasmas filaments instabilities are investigated by using the techniques of classical differential geometry of curves where Frenet torsion and curvature describe completely the motion of curves. In our case the Frenet frame changes in time and also depends upon the other coordinates taking into account the inhomogeneity of the plasma. The exponential perturbation method so commonly used to describe cosmological perturbatons is applied to magnetohydrodynamic (MHD) plasma equations to find longitudinal modes describing Alfven waves propagation modes describing plasma waves in the medium. Stability is investigated in the imaginary axis of the spectra of complex frequencies ${\\omega}$ or $Im(\\omega)\

Garcia de Andrade

2007-03-05

331

Spatiotemporal rogue events in femtosecond filamentation  

SciTech Connect

We present experimental and numerical investigations of optical extreme (rogue) event statistics recorded in the regime of femtosecond pulse filamentation in water. In the spectral domain, the extreme events manifest themselves as either large or small extremes of the spectral intensity, justified by right- or left-tailed statistical distributions, respectively. In the time domain, the observed extreme events are associated with pulse splitting and energy redistribution in space and therefore are exquisitely linked to three-dimensional, spatiotemporal dynamics and formation of the X waves.

Majus, D.; Jukna, V.; Valiulis, G.; Dubietis, A. [Department of Quantum Electronics, Vilnius University, Sauletekio Avenue 9, Building 3, LT-10222 Vilnius (Lithuania); Faccio, D. [School of Engineering and Physical Sciences, SUPA, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

2011-02-15

332

Measuring forces between two single actin filaments during bundle formation.  

PubMed

Bundles of filamentous actin are dominant cytoskeletal structures, which play a crucial role in various cellular processes. As yet quantifying the fundamental interaction between two individual actin filaments forming the smallest possible bundle has not been realized. Applying holographic optical tweezers integrated with a microfluidic platform, we were able to measure the forces between two actin filaments during bundle formation. Quantitative analysis yields forces up to 0.2 pN depending on the concentration of bundling agents. PMID:21838252

Streichfuss, Martin; Erbs, Friedrich; Uhrig, Kai; Kurre, Rainer; Clemen, Anabel E-M; Böhm, Christian H J; Haraszti, Tamás; Spatz, Joachim P

2011-09-14

333

Self-organized Propagation of Femtosecond Laser Filamentation in Air  

Microsoft Academic Search

A long plasma channel is formed with a length up to a few hundred meters when intense femtosecond laser pulses propagate in\\u000a air. We find that the propagation of the filaments in the channel shows a very complicated process including the evolution\\u000a from a single filament into two and three and even more distinct filaments periodically, and the merging of

Jie Zhang; Zuoqiang Hao; Tingting Xi; Xin Lu; Zhe Zhang; Hui Yang; Zhan Jin; Zhaohua Wang; Zhiyi Wei

2009-01-01

334

Characterization of Osmotically Induced Filaments of Salmonella enterica  

PubMed Central

Salmonella enterica forms aseptate filaments with multiple nucleoids when cultured in hyperosmotic conditions. These osmotic-induced filaments are viable and form single colonies on agar plates even though they contain multiple genomes and have the potential to divide into multiple daughter cells. Introducing filaments that are formed during osmotic stress into culture conditions without additional humectants results in the formation of septa and their division into individual cells, which could present challenges to retrospective analyses of infectious dose and risk assessments. We sought to characterize the underlying mechanisms of osmotic-induced filament formation. The concentration of proteins and chromosomal DNA in filaments and control cells was similar when standardized by biomass. Furthermore, penicillin-binding proteins in the membrane of salmonellae were active in vitro. The activity of penicillin-binding protein 2 was greater in filaments than in control cells, suggesting that it may have a role in osmotic-induced filament formation. Filaments contained more ATP than did control cells in standardized cell suspensions, though the levels of two F0F1-ATP synthase subunits were reduced. Furthermore, filaments could septate and divide within 8 h in 0.2× Luria-Bertani broth at 23°C, while nonfilamentous control cells did not replicate. Based upon the ability of filaments to septate and divide in this diluted broth, a method was developed to enumerate by plate count the number of individual, viable cells within a population of filaments. This method could aid in retrospective analyses of infectious dose of filamented salmonellae. PMID:22798362

Pratt, Zachary L.; Chen, Bingming; Czuprynski, Charles J.; Wong, Amy C. L.

2012-01-01

335

Observations of CO in the eastern filaments of NGC 1275  

Microsoft Academic Search

We recently found extended CO(2-1) emission from cold molecular gas embedded in the network of Halpha filaments surrounding the galaxy NGC 1275 (Salome et al. 2006). We now present CO(2-1) interferometer maps of the eastern filaments, at high spatial and spectral resolutions. The cold molecular gas is detected by the Plateau de Bure Interferometer along the eastern filaments over an

P. Salomé; Y. Revaz; F. Combes; J. Pety; D. Downes; A. C. Edge; A. C. Fabian

2008-01-01

336

Killer pop machines.  

PubMed

Abuse and misuse of soda vending machines has resulted in a considerable number of injuries and deaths. The machines fall forward when rocked or tilted and crush those in front. These accidents are all preventable by a simple and cheap device. There should be a law compelling safety requirements for these machines. This is a report of a recent case in which a young man was crushed to death. PMID:2329341

Spitz, D J; Spitz, W U

1990-03-01

337

Quantum Learning Machine  

E-print Network

We propose a novel notion of a quantum learning machine for automatically controlling quantum coherence and for developing quantum algorithms. A quantum learning machine can be trained to learn a certain task with no a priori knowledge on its algorithm. As an example, it is demonstrated that the quantum learning machine learns Deutsch's task and finds itself a quantum algorithm, that is different from but equivalent to the original one.

Jeongho Bang; James Lim; M. S. Kim; Jinhyoung Lee

2008-03-20

338

Actin filament organization in the fish keratocyte lamellipodium  

PubMed Central

From recent studies of locomoting fish keratocytes it was proposed that the dynamic turnover of actin filaments takes place by a nucleation- release mechanism, which predicts the existence of short (less than 0.5 microns) filaments throughout the lamellipodium (Theriot, J. A., and T. J. Mitchison. 1991. Nature (Lond.). 352:126-131). We have tested this model by investigating the structure of whole mount keratocyte cytoskeletons in the electron microscope and phalloidin-labeled cells, after various fixations, in the light microscope. Micrographs of negatively stained keratocyte cytoskeletons produced by Triton extraction showed that the actin filaments of the lamellipodium are organized to a first approximation in a two-dimensional orthogonal network with the filaments subtending an angle of around 45 degrees to the cell front. Actin filament fringes grown onto the front edge of keratocyte cytoskeletons by the addition of exogenous actin showed a uniform polarity when decorated with myosin subfragment-1, consistent with the fast growing ends of the actin filaments abutting the anterior edge. A steady drop in filament density was observed from the mid- region of the lamellipodium to the perinuclear zone and in images of the more posterior regions of lower filament density many of the actin filaments could be seen to be at least several microns in length. Quantitative analysis of the intensity distribution of fluorescent phalloidin staining across the lamellipodium revealed that the gradient of filament density as well as the absolute content of F-actin was dependent on the fixation method. In cells first fixed and then extracted with Triton, a steep gradient of phalloidin staining was observed from the front to the rear of the lamellipodium. With the protocol required to obtain the electron microscope images, namely Triton extraction followed by fixation, phalloidin staining was, significantly and preferentially reduced in the anterior part of the lamellipodium. This resulted in a lower gradient of filament density, consistent with that seen in the electron microscope, and indicated a loss of around 45% of the filamentous actin during Triton extraction. We conclude, first that the filament organization and length distribution does not support a nucleation release model, but is more consistent with a treadmilling-type mechanism of locomotion featuring actin filaments of graded length. Second, we suggest that two layers of filaments make up the lamellipodium; a lower, stabilized layer associated with the ventral membrane and an upper layer associated with the dorsal membrane that is composed of filaments of a shorter range of lengths than the lower layer and which is mainly lost in Triton. PMID:7775574

1995-01-01

339

History and phylogeny of intermediate filaments: now in insects.  

PubMed

Intermediate filaments include the nuclear lamins, which are universal in metazoans, and the cytoplasmic intermediate filaments, which are much more varied and form cell type-specific networks in animal cells. Until now, it has been thought that insects harbor lamins only. This view is fundamentally challenged by the discovery, reported in BMC Biology, of an intermediate filament-like cytoplasmic protein, isomin, in the hexapod Isotomurus maculatus. Here we briefly review the history of research on intermediate filaments, and discuss the implications of this latest finding in the context of what is known of their structure and functions. PMID:21356127

Herrmann, Harald; Strelkov, Sergei V

2011-01-01

340

Cofilin-Linked Changes in Actin Filament Flexibility Promote Severing  

PubMed Central

The actin regulatory protein, cofilin, increases the bending and twisting elasticity of actin filaments and severs them. It has been proposed that filaments partially decorated with cofilin accumulate stress from thermally driven shape fluctuations at bare (stiff) and decorated (compliant) boundaries, thereby promoting severing. This mechanics-based severing model predicts that changes in actin filament compliance due to cofilin binding affect severing activity. Here, we test this prediction by evaluating how the severing activities of vertebrate and yeast cofilactin scale with the flexural rigidities determined from analysis of shape fluctuations. Yeast actin filaments are more compliant in bending than vertebrate actin filaments. Severing activities of cofilactin isoforms correlate with changes in filament flexibility. Vertebrate cofilin binds but does not increase the yeast actin filament flexibility, and does not sever them. Imaging of filament thermal fluctuations reveals that severing events are associated with local bending and fragmentation when deformations attain a critical angle. The critical severing angle at boundaries between bare and cofilin-decorated segments is smaller than in bare or fully decorated filaments. These measurements support a cofilin-severing mechanism in which mechanical asymmetry promotes local stress accumulation and fragmentation at boundaries of bare and cofilin-decorated segments, analogous to failure of some nonprotein materials. PMID:21723825

McCullough, Brannon R.; Grintsevich, Elena E.; Chen, Christine K.; Kang, Hyeran; Hutchison, Alan L.; Henn, Arnon; Cao, Wenxiang; Suarez, Cristian; Martiel, Jean-Louis; Blanchoin, Laurent; Reisler, Emil; De La Cruz, Enrique M.

2011-01-01

341

Actin filament organization in the fish keratocyte lamellipodium.  

PubMed

From recent studies of locomoting fish keratocytes it was proposed that the dynamic turnover of actin filaments takes place by a nucleation-release mechanism, which predicts the existence of short (less than 0.5 microns) filaments throughout the lamellipodium (Theriot, J. A., and T. J. Mitchison. 1991. Nature (Lond.). 352:126-131). We have tested this model by investigating the structure of whole mount keratocyte cytoskeletons in the electron microscope and phalloidin-labeled cells, after various fixations, in the light microscope. Micrographs of negatively stained keratocyte cytoskeletons produced by Triton extraction showed that the actin filaments of the lamellipodium are organized to a first approximation in a two-dimensional orthogonal network with the filaments subtending an angle of around 45 degrees to the cell front. Actin filament fringes grown onto the front edge of keratocyte cytoskeletons by the addition of exogenous actin showed a uniform polarity when decorated with myosin subfragment-1, consistent with the fast growing ends of the actin filaments abutting the anterior edge. A steady drop in filament density was observed from the mid-region of the lamellipodium to the perinuclear zone and in images of the more posterior regions of lower filament density many of the actin filaments could be seen to be at least several microns in length. Quantitative analysis of the intensity distribution of fluorescent phalloidin staining across the lamellipodium revealed that the gradient of filament density as well as the absolute content of F-actin was dependent on the fixation method. In cells first fixed and then extracted with Triton, a steep gradient of phalloidin staining was observed from the front to the rear of the lamellipodium. With the protocol required to obtain the electron microscope images, namely Triton extraction followed by fixation, phalloidin staining was, significantly and preferentially reduced in the anterior part of the lamellipodium. This resulted in a lower gradient of filament density, consistent with that seen in the electron microscope, and indicated a loss of around 45% of the filamentous actin during Triton extraction. We conclude, first that the filament organization and length distribution does not support a nucleation release model, but is more consistent with a treadmilling-type mechanism of locomotion featuring actin filaments of graded length. Second, we suggest that two layers of filaments make up the lamellipodium; a lower, stabilized layer associated with the ventral membrane and an upper layer associated with the dorsal membrane that is composed of filaments of a shorter range of lengths than the lower layer and which is mainly lost in Triton. PMID:7775574

Small, J V; Herzog, M; Anderson, K

1995-06-01

342

Improving the electrochemical performance of carbon filaments by solvent cleansing  

SciTech Connect

Found inherent in the submicron-diameter vapor-grown carbon filament fabrication process was a tarry residue, which comprised polyaromatic hydrocarbons. Cyclic voltammetry conducted using carbon working electrodes and an iron cyanide electrolyte showed that the residue harmed the electrochemical performance. Removal of the residue from the filaments using a solvent resulted in increases in the electron transfer rate (to values as high as 0.2 cm/s) and reversibility of the iron cyanide redox species, increase in the packing density and decrease in the filament-filament contact electrical resistivity.

Shui, X.; Chung, D.D.L. [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.; Frysz, C.A. [Wilson Greatbatch, Ltd., Clarence, NY (United States)

1995-12-31

343

Parallel Kinematic Machines (PKM)  

SciTech Connect

The purpose of this 3-year cooperative research project was to develop a parallel kinematic machining (PKM) capability for complex parts that normally require expensive multiple setups on conventional orthogonal machine tools. This non-conventional, non-orthogonal machining approach is based on a 6-axis positioning system commonly referred to as a hexapod. Sandia National Laboratories/New Mexico (SNL/NM) was the lead site responsible for a multitude of projects that defined the machining parameters and detailed the metrology of the hexapod. The role of the Kansas City Plant (KCP) in this project was limited to evaluating the application of this unique technology to production applications.

Henry, R.S.

2000-03-17

344

Asymmetric universal entangling machine  

E-print Network

We give a definition of asymmetric universal entangling machine which entangles a system in an unknown state to a specially prepared ancilla. The machine produces a fixed state-independent amount of entanglement in exchange to a fixed degradation of the system state fidelity. We describe explicitly such a machine for any quantum system having $d$ levels and prove its optimality. We show that a $d^2$-dimensional ancilla is sufficient for reaching optimality. The introduced machine is a generalization to a number of widely investigated universal quantum devices such as the symmetric and asymmetric quantum cloners, the symmetric quantum entangler, the quantum information distributor and the universal-NOT gate.

Dmitri Horoshko; Mikhail Kolobov; Sergei Kilin

2004-12-23

345

What Can Turing Machines Do? How powerful are Turing machines?  

E-print Network

1 What Can Turing Machines Do? How powerful are Turing machines? Turing machines can accept any regular or context- free language. Turing machines can perform basic arithmetic computations. Sequencing can be implemented on Turing ma- chines. Subroutine calls can be implemented on Turing machines

Bylander, Tom

346

Circular tests for HSM machine tools: Bore machining application  

E-print Network

Circular tests for HSM machine tools: Bore machining application Abstract: Today's High was ultimately validated on a bore machining simulation. Keywords: circular interpolation, HSM, kinematic machine machining features can be extracted [3] [4] such as bores, holes, drillings, tapered holes and planes

Paris-Sud XI, Université de

347

Analysis of Machining Stability for a Parallel Machine Tool  

Microsoft Academic Search

Machine tool chatter is a self-excited vibration generated by chip thickness variation. It severely degrades the quality of the machined surface. The incidence of chatter is greatly affected by the dynamic characteristics of machine tool structure. This article extends chatter stability analysis to a machine tool equipped with a parallel mechanism. The vibration model of a parallel machine tool is

D. Hong; S. Kim; W. C. Choi; J.-B. Song

2003-01-01

348

Production of cutinolytic esterase by filamentous bacteria.  

PubMed

Thirty-eight strains of filamentous bacteria, many of which are thermophilic or thermotolerant and commonly found in composts and mouldy fodders, were examined for their ability to produce cutinolytic esterase (cutinase) in culture media supplemented with cutin, suberin or cutin-containing agricultural by-products. Initially, the ability of culture supernatants to hydrolyse the artificial substrate p-nitrophenyl butyrate was determined by spectrophotometric assays. Only one bacterium, Thermoactinomyces vulgaris NRRL B-16117, exhibited cutinolytic esterase production. The enzyme was highly inducible, was repressed by the presence of glucose in the medium and hydrolysed both apple and tomato cutins. Inducers included apple cutin, apple pomace, tomato peel, potato suberin and commercial cork. Unlike similar fungal enzymes, the T. vulgaris cutinolytic esterase was not inducible by cutin hydrolysate. The cutinolytic esterase exhibited a half-life of over 60 min at 70 degrees C and a pH optimum of >/= 11.0. This study indicates that thermophylic filamentous bacteria may be excellent commercial sources of heat-stable cutin-degrading enzymes that can be produced by fermentation of low cost feedstocks. PMID:10886609

Fett, W F; Wijey, C; Moreau, R A; Osman, S F

2000-07-01

349

New feather-degrading filamentous fungi.  

PubMed

Among 106 filamentous fungi isolated from poultry farm waste, 13 species belonging to seven genera (Aspergillus, Acremonium, Alternaria, Beauvaria, Curvularia, Paecilomyces, and Penicillium) were able to grow and produce keratinase in stationary cultures using poultry feather powder as the only substrate. The four most efficient keratinase producers were selected for a comparative study of keratinase production in submerged and stationary conditions. The highest keratinolytic activities were produced after 4-6 days of cultivation in submerged conditions: 53.8 +/- 6.1 U/mL (Alternaria tenuissima), 51.2 +/- 5.4 U/mL (Acremonium hyalinulum), 55.4 +/- 5.2 U/mL (Curvularia brachyspora), and 62.8 +/- 4.8 U/mL (Beauveria bassiana). These novel nondermatophytic keratinolytic fungi have potential use in biotechnological processes involving keratin hydrolysis. The results of this work contribute to show that keratinolytic activity is relatively widespread among common filamentous fungi and may have an important rule in feather decomposition in natural settings. PMID:17899245

Rodrigues Marcondes, Nadir; Ledesma Taira, Cleison; Cirena Vandresen, Daniela; Estivalet Svidzinski, Terezinha Inez; Kadowaki, Marina Kimiko; Peralta, Rosane Marina

2008-07-01

350

The Filamentous Fungal Gene Expression Database (FFGED)  

PubMed Central

Filamentous fungal gene expression assays provide essential information for understanding systemic cellular regulation. To aid research on fungal gene expression, we constructed a novel, comprehensive, free database, the Filamentous Fungal Gene Expression Database (FFGED), available at http://bioinfo.townsend.yale.edu. FFGED features user-friendly management of gene expression data, which are assorted into experimental metadata, experimental design, raw data, normalized details, and analysis results. Data may be submitted in the process of an experiment, and any user can submit multiple experiments, thus classifying the FFGED as an “active experiment” database. Most importantly, FFGED functions as a collective and collaborative platform, by connecting each experiment with similar related experiments made public by other users, maximizing data sharing among different users, and correlating diverse gene expression levels under multiple experimental designs within different experiments. A clear and efficient web interface is provided with enhancement by AJAX (Asynchronous JavaScript and XML) and through a collection of tools to effectively facilitate data submission, sharing, retrieval and visualization. PMID:20025988

Zhang, Zhang; Townsend, Jeffrey P.

2010-01-01

351

Laser filament-induced aerosol formation  

NASA Astrophysics Data System (ADS)

Using the aerosol and cloud simulation chamber AIDA we investigated the laser filament induced particle formation in ambient air, humid synthetic air, humid nitrogen, argon-oxygen mixture, and pure argon in order to simulate the particle formation under realistic atmospheric conditions as well as to investigate the influence of typical gas-phase atmospheric constituents on the particle formation. Terawatt laser plasma filaments generated new particles in the size range 3 to 130 nm with particle production rates ranging from 1 × 107 to 5 × 109 cm-3 plasma s-1. In all cases the particle formation rates increased exponentially with the water content of the gas mixture. Furthermore, the presence of a few ppb of trace gases like SO2 and ?-pinene clearly enhanced the particle yield by number, the latter also by mass. Our findings suggest that new particle formation is efficiently supported by acids generated by the photo-ionization of both major and minor components of the air, including N2, NH3, SO2 and organics.

Saathoff, H.; Henin, S.; Stelmaszczyk, K.; Petrarca, M.; Delagrange, R.; Hao, Z.; Lüder, J.; Möhler, O.; Petit, Y.; Rohwetter, P.; Schnaiter, M.; Kasparian, J.; Leisner, T.; Wolf, J.-P.; Wöste, L.

2012-11-01

352

Laser filament-induced aerosol formation  

NASA Astrophysics Data System (ADS)

Using the aerosol and cloud simulation chamber AIDA, we investigated the laser filament induced particle formation in ambient air, humid synthetic air, humid nitrogen, argon-oxygen mixture, and pure argon in order to simulate the particle formation under realistic atmospheric conditions as well as to investigate the influence of typical gas-phase atmospheric constituents on the particle formation. Terawatt laser plasma filaments generated new particles in the size range 3 to 130 nm with particle production rates ranging from 1 × 107 to 5 × 109 cm-3 plasma s-1 for the given experimental conditions. In all cases the particle formation rates increased exponentially with the water content of the gas mixture. Furthermore, the presence of a few ppb of trace gases like SO2 and ?-pinene clearly enhanced the particle yield by number, the latter also by mass. Our findings suggest that new particle formation is efficiently supported by oxidized species like acids generated by the photoionization of both major and minor components of the air, including N2, NH3, SO2 and organics.

Saathoff, H.; Henin, S.; Stelmaszczyk, K.; Petrarca, M.; Delagrange, R.; Hao, Z.; Lüder, J.; Möhler, O.; Petit, Y.; Rohwetter, P.; Schnaiter, M.; Kasparian, J.; Leisner, T.; Wolf, J.-P.; Wöste, L.

2013-05-01

353

Harmonic control of multiple-stator induction machines for voltage regulation  

E-print Network

Small, one to a few horsepower, three-phase induction machines with three sets of electrically-isolated, magnetically-coupled stator winding circuits are described. A voltage inverter is developed and used to drive one set ...

Holloway, Jack Wade, 1980-

2004-01-01

354

Investigation of self-excited induction generators for wind turbine applications  

Microsoft Academic Search

The use of squirrel-cage induction machines in wind generation is widely accepted as a generator of choice. The squirrel-cage induction machine is simple, reliable, cheap, lightweight, and requires very little maintenance. Generally, the induction generator is connected to the utility at constant frequency and operates at practically constant speed (small range of slip). The wind turbine operates in optimum efficiency

Eduard Muljadi; Jesus Sallan; M. Sanz; Charles P. Butterfield

1999-01-01

355

Voltage Stability and Power Quality Issues of Wind Farm with Series Compensation  

E-print Network

of a power system. This is due to the non-self-excitation of an induction machine in the case of a FSWT as harmonics generating sources and are modeled according to IEC standard 61000. The induction machines-speed wind turbine (FSWT) and doubly-fed induction generator (DFIG) based wind farms. The expected number

Pota, Himanshu Roy

356

Modeling and simulation of an induction drive with application to a small wind turbine generator  

Microsoft Academic Search

Among renewable energies the solution of utilizing wind energy conversion systems is now in a growing trend. A valid choice for operation of such systems may be the use of the induction machine. This study presents modeling and simulation of a stand-alone induction drive with application to a small wind turbine generator system. The model of the induction machine is

L. Tamas; Z. Szekely

2008-01-01

357

Diamond machine tool face lapping machine  

DOEpatents

An apparatus for shaping, sharpening and polishing diamond-tipped single-point machine tools. The isolation of a rotating grinding wheel from its driving apparatus using an air bearing and causing the tool to be shaped, polished or sharpened to be moved across the surface of the grinding wheel so that it does not remain at one radius for more than a single rotation of the grinding wheel has been found to readily result in machine tools of a quality which can only be obtained by the most tedious and costly processing procedures, and previously unattainable by simple lapping techniques.

Yetter, H.H.

1985-05-06

358

Pyruvate decarboxylase filaments are associated with the cortical cytoskeleton of asci and spores over the sexual cycle of filamentous ascomycetes.  

PubMed

We show that pyruvate decarboxylase (PDC) 8- to 10-nm-diameter filaments, first described in vegetative cells of Neurospora crassa, are ubiquitously present in filamentous fungi. The cellular arrangement of these structures was examined over the entire sexual cycle of the ascomycetes N. crassa, N. tetraesperma, Podospora anserina, and Sordaria macrospora. PDC-filaments were found associated with the cortical microtubule array of asci and ascospores and absent from the vicinity of spindles and spindle pole bodies. Nocodazole-induced depolymerization of the cortical microtubules results in the loss of PDC-filaments. Moreover, a S. macrospora mutant defective in cortical MT distribution shows abnormal PDC organization. Neurospora asci generated on various metabolic conditions, which modify the presence and relative abundance of PDC-filaments in vegetative cells, have identical patterns of subcellular distribution of these structures. A N. crassa mutant (snowflake) that accumulates giant bundles of PDC-filaments during vegetative growth, shows normal distribution of the filaments during ascogenesis. Thus, the regulation conditioning the presence and supramolecular assembly of PDC-filaments in Neurospora differs between vegetative and sexual cells. Taken together, these results suggest that PDC in filamentous fungi may perform two functions, intervening as an enzyme in vegetative metabolism and as a structural protein associated with the cytoskeleton during sexual development. PMID:10072321

Thompson-Coffe, C; Borioli, G; Zickler, D; Rosa, A L

1999-02-01

359

Synthesis of high performance PM motors with concentrated windings  

Microsoft Academic Search

The windings concentrated around the teeth offer obvious advantages for the electrical machines with radial air-gap, because the volume of copper used in the end-windings can be reduced. The Joule losses are decreased, and the efficiency is improved. These machines are still limited to applications of sub-fractional power and they generally present a reduced number of phases. In the three-phase

Jéröme Cros; Philippe Viarouge

2002-01-01

360

Mini-thin filaments regulated by troponin-tropomyosin.  

PubMed

Striated muscle thin filaments contain hundreds of actin monomers and scores of troponins and tropomyosins. To study the cooperative mechanism of thin filaments, "mini-thin filaments" were generated by isolating particles nearly matching the minimal structural repeat of thin filaments: a double helix of actin subunits with each strand approximately seven actins long and spanned by a troponin-tropomyosin complex. One end of the particles was capped by a gelsolin (segment 1-3)-TnT fusion protein (substituting for normal TnT), and the other end was capped by tropomodulin. EM showed that the particles were 46 +/- 9 nm long, with a knob-like mass attributable to gelsolin at one end. Average actin, tropomyosin, and gelsolin-troponin composition indicated one troponin-tropomyosin attached to each strand of the two-stranded actin filament. The minifilaments thus nearly represent single regulatory units of thin filaments. The myosin S1 MgATPase rate stimulated by the minifilaments was Ca2+-sensitive, indicating that single regulatory length particles are sufficient for regulation. Ca2+ bound cooperatively to cardiac TnC in conventional thin filaments but noncooperatively to cardiac TnC in minifilaments in the absence of myosin. This suggests that thin filament Ca2+-binding cooperativity reflects indirect troponin-troponin interactions along the long axis of conventional filaments, which do not occur in minifilaments. Despite noncooperative Ca2+ binding to minifilaments in the absence of myosin, Ca2+ cooperatively activated the myosin S1-particle ATPase rate. Two-stranded single regulatory units therefore may be sufficient for myosin-mediated Ca2+-binding cooperativity. Functional mini-thin filaments are well suited for biochemical and structural analysis of thin-filament regulation. PMID:15644437

Gong, Huiyu; Hatch, Victoria; Ali, Laith; Lehman, William; Craig, Roger; Tobacman, Larry S

2005-01-18

361

Lecture outline Support vector machines  

E-print Network

Lecture outline · Support vector machines #12;Support Vector Machines · Find a linear hyperplane (decision boundary) that will separate the data #12;Support Vector Machines · One Possible Solution #12;Support Vector Machines · Another possible solution #12;Support Vector Machines · Other possible solutions

Terzi, Evimaria

362

Lecture outline Support vector machines  

E-print Network

Lecture outline · Support vector machines #12;Support Vector Machines · Find a linear hyperplane (decision boundary) that will separate the data #12;Support Vector Machines · One Possible Solution B1 #12;Support Vector Machines · Another possible solution B2 #12;Support Vector Machines · Other possible

Terzi, Evimaria

363

14. Interior, Machine Shop, Roundhouse Machine Shop Extension, Southern Pacific ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. Interior, Machine Shop, Roundhouse Machine Shop Extension, Southern Pacific Railroad Carlin Shops, view to north (90mm lens). - Southern Pacific Railroad, Carlin Shops, Roundhouse Machine Shop Extension, Foot of Sixth Street, Carlin, Elko County, NV

364

Technique for Machining Glass  

NASA Technical Reports Server (NTRS)

Process for machining glass with conventional carbide tools requires a small quantity of a lubricant for aluminum applied to area of glass to be machined. A carbide tool is then placed against workpiece with light pressure. Tool is raised periodically to clear work of glass dust and particles. Additional lubricant is applied as it is displaced.

Rice, S. H.

1982-01-01

365

Imagining machines with imagination  

Microsoft Academic Search

The author reviews and comments upon George Morton's predictive paper “Machines with Imagination”. He argues that Morton's paper demonstrates a significant insight into the progress of machine intelligence, particularly because that progress was hardly accomplished in a linear progression of systematic advances. Indeed, the forecasts laid down in Morton's paper have become pertinent only after a series of relative failures

DAVID B. FOGEL

2000-01-01

366

Stirling machine operating experience  

SciTech Connect

Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that stirling machines are capable of reliable and lengthy operating lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and are not expected to operate for lengthy periods of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered. The record in this paper is not complete, due to the reluctance of some organizations to release operational data and because several organizations were not contacted. The authors intend to repeat this assessment in three years, hoping for even greater participation.

Ross, B. [Stirling Technology Co., Richland, WA (United States); Dudenhoefer, J.E. [Lewis Research Center, Cleveland, OH (United States)

1994-09-01

367

Simple Machines Made Simple.  

ERIC Educational Resources Information Center

Simple machines have become a lost point of study in elementary schools as teachers continue to have more material to cover. This manual provides hands-on, cooperative learning activities for grades three through eight concerning the six simple machines: wheel and axle, inclined plane, screw, pulley, wedge, and lever. Most activities can be…

St. Andre, Ralph E.

368

Cellular Multihead Turing Machine.  

National Technical Information Service (NTIS)

The Turing machine is a mathematical model for describing procedures. It can do any calculation that can be done by modern day computers. One disadvantage of the Turing machine is its very slow speed. One way to increase the speed is to increase the numbe...

L. Librizzi

1970-01-01

369

The Chemical Abstract Machine  

Microsoft Academic Search

We introduce a new kind of abstract machine based on the chemical metaphor used in the ? language of Banâtre & al. States of a machine are chemical solutions where floating molecules can interact according to reaction rules. Solutions can be stratified by encapsulating subsolutions within membranes that force reactions to occur locally. We illustrate the use of this model

Gérard Berry; Gérard Boudol

1990-01-01

370

Cape Blanco wind farm feasibility study  

NASA Astrophysics Data System (ADS)

The Cape Blanco Wind Farm (CBWF) Feasibility Study was undertaken as a prototype for determining the feasibility of proposals for wind energy projects at Northwest sites. It was intended to test for conditions under which wind generation of electricity could be commercially feasible, not by another abstract survey of alternative technologies, but rather through a site-specific, machine-specific analysis of one proposal. Some of the study findings would be most pertinent to the Cape Blanco site - local problems require local solutions. Other findings would be readily applicable to other sites and other machines, and study methodologies would be designed to be modified for appraisal of other proposals. This volume discusses environmental, economic, and technical issues of the Wind Farm.

1987-11-01

371

From Reduction Machines To Narrowing Machines  

Microsoft Academic Search

Narrowing, the evaluation mechanism of functional logic languages, can be seen as a generalizationof reduction, the evaluation mechanism of purely functional languages. The unidirectionalpattern matching, which is used for parameter passing in functional languages, is simplyreplaced by the bidirectional unification known from logic programming languages. We showin this paper, how to extend a reduction machine, that has been designed for

Rita Loogen; RWTH Aachen

1991-01-01

372

Biophysics of filament length regulation by molecular motors  

E-print Network

Regulating physical size is an essential problem that biological organisms must solve from the subcellular to the organismal scales, but it is not well understood what physical principles and mechanisms organisms use to sense and regulate their size. Any biophysical size-regulation scheme operates in a noisy environment and must be robust to other cellular dynamics and fluctuations. This work develops theory of filament length regulation inspired by recent experiments on kinesin-8 motor proteins, which move with directional bias on microtubule filaments and alter microtubule dynamics. Purified kinesin-8 motors can depolymerize chemically-stabilized microtubules. In the length-dependent depolymerization model, the rate of depolymerization tends to increase with filament length, because long filaments accumulate more motors at their tips and therefore shorten more quickly. When balanced with a constant filament growth rate, this mechanism can lead to a fixed polymer length. However, the mechanism by which kinesin-8 motors affect the length of dynamic microtubules in cells is less clear. We study the more biologically realistic problem of microtubule dynamic instability modulated by a motor-dependent increase in the filament catastrophe frequency. This leads to a significant decrease in the mean filament length and a narrowing of the filament length distribution. The results improve our understanding of the biophysics of length regulation in cells.

Hui-Shun Kuan; M. D. Betterton

2013-02-13

373

Bending Flexibility of Actin Filaments during Motor-Induced Sliding  

PubMed Central

Muscle contraction and other forms of cell motility occur as a result of cyclic interactions between myosin molecules and actin filaments. Force generation is generally attributed to ATP-driven structural changes in myosin, whereas a passive role is ascribed to actin. However, some results challenge this view, predicting structural changes in actin during motor activity, e.g., when the actin filaments slide on a myosin-coated surface in vitro. Here, we analyzed statistical properties of the sliding filament paths, allowing us to detect changes of this type. It is interesting to note that evidence for substantial structural changes that led to increased bending flexibility of the filaments was found in phalloidin-stabilized, but not in phalloidin-free, actin filaments. The results are in accordance with the idea that a high-flexibility structural state of actin is a prerequisite for force production, but not the idea that a low-to-high flexibility transition of the actin filament should be an important component of the force-generating step per se. Finally, our data challenge the general view that phalloidin-stabilized filaments behave as native actin filaments in their interaction with myosin. This has important implications, since phalloidin stabilization is a routine procedure in most studies of actomyosin function. PMID:18835897

Vikhorev, Petr G.; Vikhoreva, Natalia N.; Mansson, Alf

2008-01-01

374

Actin Filament Segmentation using Spatiotemporal Active-Surface and  

E-print Network

Actin Filament Segmentation using Spatiotemporal Active-Surface and Active-Contour Models Hongsheng a novel algorithm for actin filament segmen- tation in a 2D TIRFM image sequence. We treat the 2D time of this approach. 1 Introduction Actin proteins spontaneously assemble into long polymers to build networks

Huang, Xiaolei

375

Dictyostelium Myosin Bipolar Thick Filament Formation: Importance of Charge  

E-print Network

Dictyostelium Myosin Bipolar Thick Filament Formation: Importance of Charge and Specific Domains of the Myosin Rod Daniel Hostetter1[¤1 , Sarah Rice1[¤2 , Sara Dean1 , David Altman1 , Peggy M. McMahon2 of America Myosin-II thick filament formation in Dictyostelium is an excellent system for investigating

Spudich, James A.

376

Dynamics of filamentous viral RNPs prior to egress  

Microsoft Academic Search

The final step in the maturation of paramyxoviruses, orthomyxoviruses and viruses of several other families, entails the budding of the viral nucleo- capsid through the plasma membrane of the host cell. Many medically important viruses, such as influenza, parainfluenza, respiratory syncytial virus (RSV) and Ebola, can form filamentous particles when budding. Although filamentous virions have been previously studied, details of

Philip J. Santangelo; Gang Bao

2007-01-01

377

The effect of delays on filament oscillations and stability  

NASA Astrophysics Data System (ADS)

We discuss the linear response of a filament to perturbations, taking the finite communication time between the filament and the photosphere into account. The finite communication time introduces delays in the system. Recently Schutgens (1997ab) investigated the solutions of the delay equation for vertical perturbations. In this paper we expand his analysis by considering also horizontal and coupled oscillations. The latter occur in asymmetric coronal fields. We also discuss the effect of Alfven wave emission on filament oscillations and show that wave emission is important for stabilizing filaments. We introduce a fairly straightforward method to study the solutions of delay equations as a function of the filament-photosphere communication time. A solution can be described by a linear combination of damped harmonic oscillations each characterized by a frequency, a damping/growth time and, accordingly, a quality factor. As a secondary result of our analysis we show that, within the context of line current models, Kippenhahn/Schlüter-type filament equilibria can never be stable in the horizontal and the vertical direction at the same time but we also demonstrate that Kuperus/Raadu-type equilibria can account for both an inverse or a normal polarity signature. The diagnostic value of our analysis for determining, e.g., the filament current from observations of oscillating filaments is discussed.

van den Oord, G. H. J.; Schutgens, N. A. J.; Kuperus, M.

1998-11-01

378

THEMIS, BBSO, MDI AND TRACEOBSERVATIONS OF A FILAMENT ERUPTION  

E-print Network

(Antiochos and Klimchuk, 1991; Antiochos, Dahlburg, and Klimchuk, 1994) proposed that filament formation to the neutral line, with the consequent formation of a c fl 2003 Kluwer Academic Publishers. Printed, and Rust, 1977) or during gradual changes of the magnetic topology surrounding the filament which lead

Yurchyshyn, Vasyl

379

Controlling the Shape of Filamentous Cells of Escherichia coli  

E-print Network

Controlling the Shape of Filamentous Cells of Escherichia coli Shoji Takeuchi,, Willow R. Di of Escherichia coli with defined shapes, including crescents, zigzags, sinusoids, and spirals. The procedure into solution. This paper describes a technique for controlling the shape of filamentous cells of Escherichia

Weibel, Douglas B.

380

Galaxy Spin Alignment in Filaments and Sheets: Observational Evidence  

NASA Astrophysics Data System (ADS)

The properties of galaxies are known to be affected by their environment. One important question is how their angular momentum reflects the surrounding cosmic web. We use the Sloan Digital Sky Survey to investigate the spin axes of spiral and elliptical galaxies relative to their surrounding filament/sheet orientations. To detect filaments, a marked point process with interactions (the "Bisous model") is used. Sheets are found by detecting "flattened" filaments. The minor axes of ellipticals are found to be preferentially perpendicular to hosting filaments. A weak correlation is found with sheets. These findings are consistent with the notion that elliptical galaxies formed via mergers, which predominantly occurred along the filaments. The spin axis of spiral galaxies is found to align with the host filament, with no correlation between spiral spin and sheet normal. When examined as a function of distance from the filament axis, a much stronger correlation is found in the outer parts, suggesting that the alignment is driven by the laminar infall of gas from sheets to filaments. When compared with numerical simulations, our results suggest that the connection between dark matter halo and galaxy spin is not straightforward. Our results provide an important input to the understanding of how galaxies acquire their angular momentum.

Tempel, Elmo; Libeskind, Noam I.

2013-10-01

381

Hydrodynamic interaction induced spontaneous rotation of coupled active filaments.  

PubMed

We investigate the coupled dynamics of active filaments with long range hydrodynamic interactions (HI). Remarkably, we find that filaments can rotate spontaneously under the same conditions in which a single filament alone can only move in translation. Detailed analysis reveals that the emergence of coupled rotation originates from an asymmetric flow field associated with HI which breaks the symmetry of translational motion when filaments approach. The breaking is then further stabilized by HI to form self-sustained coupled rotation. Intensive simulations show that coupled rotation forms easily when one filament tends to collide with the front-half of the other. For head-to-tail approaching, we observe another interesting HI-induced coupled motion, where filaments move together in the form of one following the other. Moreover, the radius of coupled rotation increases exponentially as the rigidity of the filament increases, which suggests that HI are also important for the alignment of rigid-rod-like filaments which has been assumed to be solely a consequence of direct collisions. PMID:25322453

Jiang, Huijun; Hou, Zhonghuai

2014-11-01

382

Programmable smart electron emission controller for hot filament  

Microsoft Academic Search

In electron ionization source, electrons are produced through thermionic emission by heating a wire filament, accelerating the electrons by high voltage, and ionizing the analyzed molecules. In such a system, one important parameter is the filament emission current that determines the ionization rate; therefore, one needs to regulate this current. On the one hand, fast responses control is needed to

Eli Flaxer

2011-01-01

383

Probing the cosmic web: intercluster filament detection using gravitational lensing  

Microsoft Academic Search

The problem of detecting dark matter filaments in the cosmic web is considered. Weak lensing is an ideal probe of dark matter, and therefore forms the basis of particularly promising detection methods. We consider and develop a number of weak lensing techniques that could be used to detect filaments in individual or stacked cluster fields, and apply them to synthetic

James M. G. Mead; Lindsay J. King; Ian G. McCarthy

2010-01-01

384

Preparation of chitosan filament applying new coagulation system  

Microsoft Academic Search

A new coagulation system for chitosan, aqueous alcohol solution of calcium chloride or acetate, was found and successfully applied for spinning of chitosan filament. FT-IR and atomic absorption spectrophotometric experiments indicated that chitosan coagulation was induced through calcium chelation with amino group of chitosan molecule. The original spun filament was soluble in water because chitosan exists as an acetic acid

Hiroshi Tamura; Yukihiko Tsuruta; Kouki Itoyama; Wannasiri Worakitkanchanakul; Ratana Rujiravanit; Seiichi Tokura

2004-01-01

385

Astrochemistry Along the Orion Integral-shaped Filament  

Microsoft Academic Search

The Integral Shaped Filament (ISF) in Orion A contains numerous star-forming centers, the most famous of which is the Orion Nebula. Using SCUBA on the JCMT, we have extensively mapped the dust emission from the ISF. Analysis of the data reveals that the filament is NOT an isothermal cylinder, requiring a shallower radial density profile to match the emission. There

Doug Johnstone; A. M. S. Bonnman; E. F. van Dishoeck

2003-01-01

386

Verifying Stiffness Parameters Of Filament-Wound Cylinders  

NASA Technical Reports Server (NTRS)

Predicted engineering stiffness parameters of filament-wound composite-material cylinders verified with respect to experimental data, by use of equations developed straightforwardly from applicable formulation of Hooke's law. Equations derived in engineering study of filament-wound rocket-motor cases, also applicable to other cylindrical pressure vessels made of orthotropic materials.

Verderaime, V.; Rheinfurth, M.

1994-01-01

387

Ultrafast laser filamentation control techniques for remote applications  

Microsoft Academic Search

Two methods of filamentation control for remote applications were studied. The first one consisted in an adaptive optic system, implemented in a specially designed focusing beam expander, which corrected for wavefront aberrations. Using this setup we are able to generate extraordinarily strong nitrogen signals at a distance as far as 90 m using 40 mJ laser pulses. Moreover, the filaments

J.-F. Daigle; O. Kosareva; Y. Kamali; M. Chateauneuf; J. Dubois; F. Theberge; G. Roy; See Leang Chin

2009-01-01

388

Method for simultaneously coating a plurality of filaments  

DOEpatents

Methods and apparatuses for coating materials, and the products and compositions produced thereby. Substances, such as diamond or diamond-like carbon, are deposited onto materials, such as a filament or a plurality of filaments simultaneously, using one or more cylindrical, inductively coupled, resonator plasma reactors.

Miller, Paul A. (1004 Matia Ct. NE., Albuquerque, NM 87123); Pochan, Paul D. (3308 Morris St. NE., #11, Albuquerque, NM 87111); Siegal, Michael P. (9900 Spain NE., Apt. W-2123, Albuquerque, NM 87111); Dominguez, Frank (11341 Academy Ridge Rd. NE., Albuquerque, NM 87111)

1995-01-01

389

Method for simultaneously coating a plurality of filaments  

DOEpatents

Methods and apparatuses are disclosed for coating materials, and the products and compositions produced thereby. Substances, such as diamond or diamond-like carbon, are deposited onto materials, such as a filament or a plurality of filaments simultaneously, using one or more cylindrical, inductively coupled, resonator plasma reactors. 3 figs.

Miller, P.A.; Pochan, P.D.; Siegal, M.P.; Dominguez, F.

1995-07-11

390

The art and design of genetic screens: filamentous fungi  

Microsoft Academic Search

In the 1940s, screens for metabolic mutants of the filamentous fungus Neurospora crassa established the fundamental, one-to-one relationship between a gene and a specific protein, and also established fungi as important genetic organisms. Today, a wide range of filamentous species, which represents a billion years of evolutionary divergence, is used for experimental studies. The developmental complexity of these fungi sets

Miriam Zolan; Lorna Casselton

2002-01-01

391

The motion of a falling liquid filament Diane Hendersona)  

E-print Network

The motion of a falling liquid filament Diane Hendersona) William G. Pritchard Fluid Mechanics points. A nearby but different problem, on the stability of a uniform liquid jet, was studied long ago, because a uni- form liquid jet and a falling liquid filament are different. This can be seen in at least

Smolka, Linda B.

392

Finite element analyses of continuous filament ties for masonry applications:final report for the Arquin Corporation.  

SciTech Connect

Finite-element analyses were performed to simulate the response of a hypothetical masonry shear wall with and without continuous filament ties to various lateral loads. The loads represented three different scenarios: (1) 100 mph wind, (2) explosive attack, and (3) an earthquake. In addition, a static loading analysis and cost comparison were performed to evaluate optimal materials and designs for the spacers affixed to the filaments. Results showed that polypropylene, ABS, and polyethylene (high density) were suitable materials for the spacers based on performance and cost, and the short T-spacer design was optimal based on its performance and functionality. Results of the shear-wall loading simulations revealed that simulated walls with the continuous filament ties yielded factors of safety that were at least ten times greater than those without the ties. In the explosive attack simulation (100 psi), the simulated wall without the ties failed (minimum factor of safety was less than one), but the simulated wall with the ties yielded a minimum factor of safety greater than one. Simulations of the walls subject to lateral loads caused by 100 mph winds (0.2 psi) and seismic events with a peak ground acceleration of 1 ''g'' (0.66 psi) yielded no failures with or without the ties. Simulations of wall displacement during the seismic scenarios showed that the wall with the ties resulted in a maximum displacement that was 20% less than the wall without the ties.

Quinones, Armando (Arquin Corporation, La Luz, NM); Bibeau, Tiffany A.; Ho, Clifford Kuofei

2006-06-01

393

Finite element analysis of filament-wound composite pressure vessel under internal pressure  

NASA Astrophysics Data System (ADS)

In this study, finite element analysis (FEA) of composite overwrapped pressure vessel (COPV), using commercial software ABAQUS 6.12 was performed. The study deals with the simulation of aluminum pressure vessel overwrapping by Carbon/Epoxy fiber reinforced polymer (CFRP). Finite element method (FEM) was utilized to investigate the effects of winding angle on filament-wound pressure vessel. Burst pressure, maximum shell displacement and the optimum winding angle of the composite vessel under pure internal pressure were determined. The Laminae were oriented asymmetrically for [00,00]s, [150,-150]s, [300,-300]s, [450,-450]s, [550,-550]s, [600,-600]s, [750,-750]s, [900,-900]s orientations. An exact elastic solution along with the Tsai-Wu, Tsai-Hill and maximum stress failure criteria were employed for analyzing data. Investigations exposed that the optimum winding angle happens at 550 winding angle. Results were compared with the experimental ones and there was a good agreement between them.

Sulaiman, S.; Borazjani, S.; Tang, S. H.

2013-12-01

394

On parallel machine scheduling 1  

E-print Network

On parallel machine scheduling 1 machines with setup times. The setup has to be performed by a single server. The objective is to minimize even for the case of two identical parallel machines. This paper presents a pseudopolynomial

Magdeburg, Universität

395

Apparatus For Laminating Segmented Core For Electric Machine  

DOEpatents

A segmented core for an electric machine includes segments stamped from coated electric steel. The segments each have a first end, a second end, and winding openings. A predetermined number of segments are placed end-to-end to form layers. The layers are stacked such that each of the layers is staggered from adjacent layers by a predetermined rotation angle. The winding openings of each of the layers are in vertical alignment with the winding openings of the adjacent layers. The stack of layers is secured to form the segmented core.

Lawrence, Robert Anthony (Kokomo, IN); Stabel, Gerald R (Swartz Creek, MI)

2003-06-17

396

Integrated inverter\\/induction machine design based on operating conditions for electrical generation  

Microsoft Academic Search

New applications, like electrical power generation, present new challenges in designing induction machines due to specific operation conditions. Wind generation demands the machine for operating doubly fed, requiring an electrical installation based on long cable lengths connecting the converter to the generator. What results in rotor and stator circuits operate under high voltage with high gradients and damped high frequencies

H. B. Goncalves; O. F. Soares; A. S. Araujo; A. S. Carvalho

2005-01-01

397

Analysis of Electromechanical Interactions in a Flywheel System With a Doubly Fed Induction Machine  

Microsoft Academic Search

This paper analyzes the electromechanical interac- tion in a flywheel system with a doubly fed induction machine, used for wind farm power smoothing or grid frequency response control. The grid-connected electrical machine is subject to power control, and this can cause it to produce negative damping to the shaft torsional vibration. Resonance must be prevented, and this paper proposes a

Li Ran; Dawei Xiang; James L. Kirtley

2011-01-01

398

Analysis of Electromechanical Interactions in a Flywheel System with a Doubly Fed Induction Machine  

Microsoft Academic Search

This paper analyzes the electromechanical inter-action in a flywheel system with a doubly fed induction machine, used for wind farm power smoothing or grid frequency response control. The grid-connected electrical machine is subject to power control and this can cause it to produce negative damping to the shaft torsional vibration. Resonance must be prevented and the study proposes a solution

Li Ran; Dawei Xiang; James L. Kirtley Jr

2010-01-01

399

Transverse Flux Machines for Sustainable Development - Road Transportation and Power Generation  

Microsoft Academic Search

The higher specific torque and power density of a transverse flux machine (TFM) in comparison to a conventional machine makes it a promising energy converter in various applications. In this paper, a free piston energy converter and a direct-driven wind turbine are considered. The analytical investigation of the novel TFM topology applied in these two cases is presented. The cogging

D. Svechkarenko; A. Cosic; J. Soulard; C. Sadarangani

2007-01-01

400

Investigation of Internal Fault Modeling of Powerformer Part I: The Machine Model  

Microsoft Academic Search

This paper discusses the set-up of a mathematical model of powerformer, a new type of salient pole synchronous machine, for analyzing internal phase and ground faults in stator windings. The method employs a direct phase representation considering the cable capacitance. To effectively implement the internal fault simulation, the magnetic axis locations of fault parts are arranged appropriately. Besides, all machine

Qing Tian

2006-01-01

401

Structure and orientation of troponin in the thin filament.  

PubMed

The troponin complex on the thin filament plays a crucial role in the regulation of muscle contraction. However, the precise location of troponin relative to actin and tropomyosin remains uncertain. We have developed a method of reconstructing thin filaments using single particle analysis that does not impose the helical symmetry of actin and is independent of a starting model. We present a single particle three-dimensional reconstruction of the thin filament. Atomic models of the F-actin filament were fitted into the electron density maps and troponin and tropomyosin located. The structure provides evidence that the globular head region of troponin labels the two strands of actin with a 27.5-A axial stagger. The density attributed to troponin appears tapered with the widest point toward the barbed end. This leads us to interpret the polarity of the troponin complex in the thin filament as reversed with respect to the widely accepted model. PMID:19321455

Paul, Danielle M; Morris, Edward P; Kensler, Robert W; Squire, John M

2009-05-29

402

Programmable smart electron emission controller for hot filament.  

PubMed

In electron ionization source, electrons are produced through thermionic emission by heating a wire filament, accelerating the electrons by high voltage, and ionizing the analyzed molecules. In such a system, one important parameter is the filament emission current that determines the ionization rate; therefore, one needs to regulate this current. On the one hand, fast responses control is needed to keep the emission current constant, but on the other hand, we need to protect the filament from damage that occurs by large filaments current transients and overheating. To control our filament current and emission current, we developed a digital circuit based on a digital signal processing controller that has several modes of operation. We used a smart algorithm that has a fast response to a small signal and a slow response to a large signal. In addition, we have several protective measures that prevent the current from reaching unsafe values. PMID:21361637

Flaxer, Eli

2011-02-01

403

An archaeal RadA paralog influences presynaptic filament formation  

PubMed Central

Recombinases of the RecA family play vital roles in homologous recombination, a high-fidelity mechanism to repair DNA double-stranded breaks. These proteins catalyze strand invasion and exchange after forming dynamic nucleoprotein filaments on ssDNA. Increasing evidence suggests that stabilization of these dynamic filaments is a highly conserved function across diverse species. Here, we analyze the presynaptic filament formation and DNA binding characteristics of the Sulfolobus solfataricus recombinase SsoRadA in conjunction with the SsoRadA paralog SsoRal1. In addition to constraining SsoRadA ssDNA-dependent ATPase activity, the paralog also enhances SsoRadA ssDNA binding, effectively influencing activities necessary for presynaptic filament formation. These activities result in enhanced SsoRadA-mediated strand invasion in the presence of SsoRal1 and suggest a filament stabilization function for the SsoRal1 protein. PMID:23622866

Graham, William J.; Rolfsmeier, Michael L.; Haseltine, Cynthia A.

2014-01-01

404

Programmable smart electron emission controller for hot filament  

NASA Astrophysics Data System (ADS)

In electron ionization source, electrons are produced through thermionic emission by heating a wire filament, accelerating the electrons by high voltage, and ionizing the analyzed molecules. In such a system, one important parameter is the filament emission current that determines the ionization rate; therefore, one needs to regulate this current. On the one hand, fast responses control is needed to keep the emission current constant, but on the other hand, we need to protect the filament from damage that occurs by large filaments current transients and overheating. To control our filament current and emission current, we developed a digital circuit based on a digital signal processing controller that has several modes of operation. We used a smart algorithm that has a fast response to a small signal and a slow response to a large signal. In addition, we have several protective measures that prevent the current from reaching unsafe values.

Flaxer, Eli

2011-02-01

405

Condensation of actin filaments pushing against a barrier  

E-print Network

We develop a model to describe the force generated by the polymerization of an array of parallel biofilaments. The filaments are assumed to be coupled only through mechanical contact with a movable barrier. We calculate the filament density distribution and the force-velocity relation with a mean-field approach combined with simulations. We identify two regimes: a non-condensed regime at low force in which filaments are spread out spatially, and a condensed regime at high force in which filaments accumulate near the barrier. We confirm a result previously known from other related studies, namely that the stall force is equal to N times the stall force of a single filament. In the model studied here, the approach to stalling is very slow, and the velocity is practically zero at forces significantly lower than the stall force.

K. Tsekouras; D. Lacoste; K. Mallick; J. -F. Joanny

2011-01-06

406

Affinity selection using filamentous phage display.  

PubMed

Display of peptides on filamentous phage, phage display, is an in vitro selection technique well suited for identification of therapeutic peptide binders for a huge variety of protein targets. The peptides are identified in a process where phage libraries are subjected to affinity selection towards a particular protein target. A successful outcome of an affinity selection is dependent on proper surveillance of the phage life cycle, to make sure that the selection is based on affinity for the target, not on bias in phage propagation rate. In this chapter we present two approaches for protein target presentation and a protocol for phage rescue and propagation, which includes several controls to ensure that all phages initially eluted from the protein target are given equal conditions during the following amplification and selection steps. PMID:24146397

Kulseth, Mari Ann; Fagerlund, Annette; Myrset, Astrid Hilde

2014-01-01

407

Segmented filamentous bacteria take the stage  

PubMed Central

Commensal bacteria are crucial for maturation and function of the mucosal immune system. However, the mechanisms of these interactions are poorly understood. In addition, the role of the composition of the microbiota and the importance of individual species in this community in stimulating different types of immunity are major unanswered questions. We recently demonstrated that the balance between two major effector T cell populations in the intestine, IL-17+ Th17 cells and Foxp3+ Tregs, requires signals from commensal bacteria and is dependent on the composition of the intestinal microbiota. Comparison of microbiota from Th17 cell-deficient and Th17 cell-sufficient mice identified segmented filamentous bacteria (SFB) as capable of specifically inducing Th17 cells in the gut. SFB represent the first example of a commensal species that can skew the mucosal effector T cell balance and thus affect the immune fitness of the individual. PMID:20147894

Ivanov, Ivaylo I.; Littman, Dan R.

2010-01-01

408

Cryogenic glass-filament-wound tank evaluation  

NASA Technical Reports Server (NTRS)

High-pressure glass-filament-wound fluid storage vessels with thin aluminum liners were designed, fabricated, and tested at ambient and cryogenic temperatures which demonstrated the feasibility of producing such vessels as well as high performance and light weight. Significant developments and advancements were made in solving problems associated with the thin metal liners in the tanks, including liner bonding to the overwrap and high strain magnification at the vessel polar bosses. The vessels had very high burst strengths, and failed in cyclic fatigue tests by local liner fracture and leakage without structural failure of the composite tank wall. The weight of the tanks was only 40 to 55% of comparable 2219-T87 aluminum and Inconel 718 tanks.

Morris, E. E.; Landes, R. E.

1971-01-01

409

RADIATION SPECTRAL SYNTHESIS OF RELATIVISTIC FILAMENTATION  

SciTech Connect

Radiation from many astrophysical sources, e.g., gamma-ray bursts and active galactic nuclei, is believed to arise from relativistically shocked collisionless plasmas. Such sources often exhibit highly transient spectra evolving rapidly compared with source lifetimes. Radiation emitted from these sources is typically associated with nonlinear plasma physics, complex field topologies, and non-thermal particle distributions. In such circumstances, a standard synchrotron paradigm may fail to produce accurate conclusions regarding the underlying physics. Simulating spectral emission and spectral evolution numerically in various relativistic shock scenarios is then the only viable method to determine the detailed physical origin of the emitted spectra. In this Letter, we present synthetic radiation spectra representing the early stage development of the filamentation (streaming) instability of an initially unmagnetized plasma, which is relevant for both collisionless shock formation and reconnection dynamics in relativistic astrophysical outflows as well as for laboratory astrophysics experiments. Results were obtained using a highly efficient in situ diagnostics method, based on detailed particle-in-cell modeling of collisionless plasmas. The synthetic spectra obtained here are compared with those predicted by a semi-analytical model for jitter radiation from the filamentation instability, the latter including self-consistent generated field topologies and particle distributions obtained from the simulations reported upon here. Spectra exhibit dependence on the presence-or the absence-of an inert plasma constituent, when comparing baryonic plasmas (i.e., containing protons) with pair plasmas. The results also illustrate that considerable care should be taken when using lower-dimensional models to obtain information about the astrophysical phenomena generating observed spectra.

Frederiksen, Jacob Trier; Haugboelle, Troels; Medvedev, Mikhail V.; Nordlund, Ake, E-mail: trier@nbi.d [Niels Bohr International Academy, Blegdamsvej 17, DK-2199 Koebenhavn (Denmark)

2010-10-10

410

Analysis of the Yokeless And Segmented Armature Machine  

Microsoft Academic Search

This paper presents a new type of axial flux motor, the yokeless and segmented armature (YASA) topology. The YASA motor has no stator yoke, a high fill factor and short end windings which all increase torque density and efficiency of the machine. Thus, the topology is highly suited for high performance applications. The LIFEcar project is aimed at producing the

T. J. Woolmer; M. D. McCulloch

2007-01-01

411

Triboelectrification Based Motion Sensor for Human-Machine Interfacing  

E-print Network

vector sensor,20 tactile sensor,21 tracking sensor,22 and acoustic sensor.23 It is known that human skin nanosensors,14,15 biosensor,16 displacement vector sensor,17 acceleration sensor,18 pressure sensor,19 windTriboelectrification Based Motion Sensor for Human-Machine Interfacing Weiqing Yang,,, Jun Chen

Wang, Zhong L.

412

Characterizing pivot sprinklers using an experimental irrigation machine  

Microsoft Academic Search

In this work, a Fixed Spray Plate Sprinkler (FSPS) and two Rotating Spray Plate Sprinklers (RSPS) were compared in terms of wetted diameter, wind drift and evaporation losses (WDEL), static water precipitation pattern and dynamic water application profile. An experimental irrigation machine reproducing a pivot section was constructed and used to perform experiments in static and dynamic (linear displacement) modes.

E. Playán; S. Garrido; J. M. Faci; A. Galán

2004-01-01

413

Break-even investment in a wind-energy-conversion system for an irrigated farm on the Texas High Plains  

Microsoft Academic Search

The purpose of this study was to quantify the benefits of using a wind energy system for irrigation. The value of wind energy was estimated on both a static basis (where the annual value of wind power was assumed to be constant over the life of the machine) and on a temporal basis (where the annual value of wind power

1981-01-01

414

A review of UK wind energy activities  

NASA Astrophysics Data System (ADS)

Wind power activities in Great Britain are reviewed, including a brief summary of historical windmill usage and details of developmental efforts in large and small wind turbines. An annual average resource of 5 m/sec at 10 m has been extrapolated to predict an 8-10 m/sec resource at the hub heights of large wind turbines. Initial estimates indicate that at least half of Great Britain's annual electricity consumption can be produced from windpowered generators. The potential of offshore large WECS siting is being examined, although the wind-derived electricity from those regions are projected to cost three times that of land-based operation. Recorded wind patterns with 12-48 hr. duration have indicated that at least 20% penetration into the national grid is acceptable. A test 250 kW machine is being built as a model for a 3.7 MW machine, both intended for installation at Orkney, Scotland. Additionally, construction has begun on a 25-m diameter, vertical axis, variable geometry Musgrove wind turbine. The straight-bladed machine will produce a maximum of 130 kW, and is a prototype of multi-MW offshore units.

Musgrove, P. J.

1982-01-01

415

The Basic Anaesthesia Machine  

PubMed Central

After WTG Morton's first public demonstration in 1846 of use of ether as an anaesthetic agent, for many years anaesthesiologists did not require a machine to deliver anaesthesia to the patients. After the introduction of oxygen and nitrous oxide in the form of compressed gases in cylinders, there was a necessity for mounting these cylinders on a metal frame. This stimulated many people to attempt to construct the anaesthesia machine. HEG Boyle in the year 1917 modified the Gwathmey's machine and this became popular as Boyle anaesthesia machine. Though a lot of changes have been made for the original Boyle machine still the basic structure remains the same. All the subsequent changes which have been brought are mainly to improve the safety of the patients. Knowing the details of the basic machine will make the trainee to understand the additional improvements. It is also important for every practicing anaesthesiologist to have a thorough knowledge of the basic anaesthesia machine for safe conduct of anaesthesia. PMID:24249876

Gurudatt, CL

2013-01-01

416

DNA-Based Machines.  

PubMed

The base sequence in nucleic acids encodes substantial structural and functional information into the biopolymer. This encoded information provides the basis for the tailoring and assembly of DNA machines. A DNA machine is defined as a molecular device that exhibits the following fundamental features. (1) It performs a fuel-driven mechanical process that mimics macroscopic machines. (2) The mechanical process requires an energy input, "fuel." (3) The mechanical operation is accompanied by an energy consumption process that leads to "waste products." (4) The cyclic operation of the DNA devices, involves the use of "fuel" and "anti-fuel" ingredients. A variety of DNA-based machines are described, including the construction of "tweezers," "walkers," "robots," "cranes," "transporters," "springs," "gears," and interlocked cyclic DNA structures acting as reconfigurable catenanes, rotaxanes, and rotors. Different "fuels", such as nucleic acid strands, pH (H(+)/OH(-)), metal ions, and light, are used to trigger the mechanical functions of the DNA devices. The operation of the devices in solution and on surfaces is described, and a variety of optical, electrical, and photoelectrochemical methods to follow the operations of the DNA machines are presented. We further address the possible applications of DNA machines and the future perspectives of molecular DNA devices. These include the application of DNA machines as functional structures for the construction of logic gates and computing, for the programmed organization of metallic nanoparticle structures and the control of plasmonic properties, and for controlling chemical transformations by DNA machines. We further discuss the future applications of DNA machines for intracellular sensing, controlling intracellular metabolic pathways, and the use of the functional nanostructures for drug delivery and medical applications. PMID:24647836

Wang, Fuan; Willner, Bilha; Willner, Itamar

2014-01-01

417

Development of a process for producing ribbon shaped filaments. [production of silicon carbide filaments  

NASA Technical Reports Server (NTRS)

Silicon carbide (SiC) ribbon filaments were produced on a carbon ribbon substrate, about 1500 microns (60 mils) wide and 100 microns (4 mils) thick in lengths up to 2 meters (6 ft), and with tensile strengths up to 142 KN/cm sq (206 Ksi). During the course of the study, ribbon filaments of boron were also produced on the carbon ribbon substrate; the boron ribbon produced was extremely fragile. The tensile strength of the SiC ribbon was limited by large growths or flaws caused by anomalies at the substrate surface; these anomalies were either foreign dirt or substrate imperfections or both. Related work carried out on round 100 micron (4 mils) diameter SiC filaments on a 33 micron (1.3 mil) diameter, very smooth carbon monofilament substrate has shown that tensile strengths as high as 551 KN/cm sq (800 Ksi) are obtainable with the SiC-carbon round substrate combination, and indicates that if the ribbon substrate surface and ribbon deposition process can be improved similar strengths can be realizable. Cost analysis shows that 100 micron x 5-10 micron SiC ribbon can be very low cost reinforcement material.

Debolt, H. E.; Krukonis, V. J.

1973-01-01

418

Hyperphosphorylation induces self-assembly of ? into tangles of paired helical filaments/straight filaments  

PubMed Central

The microtubule-associated protein ? is a family of six isoforms that becomes abnormally hyperphosphorylated and accumulates in the form of paired helical filaments (PHF) in the brains of patients with Alzheimer's disease (AD) and patients with several other tauopathies. Here, we show that the abnormally hyperphosphorylated ? from AD brain cytosol (AD P-?) self-aggregates into PHF-like structures on incubation at pH 6.9 under reducing conditions at 35°C during 90 min. In vitro dephosphorylation, but not deglycosylation, of AD P-? inhibits its self-association into PHF. Furthermore, hyperphosphorylation induces self-assembly of each of the six ? isoforms into tangles of PHF and straight filaments, and the microtubule binding domains/repeats region in the absence of the rest of the molecule can also self-assemble into PHF. Thus, it appears that ? self-assembles by association of the microtubule binding domains/repeats and that the abnormal hyperphosphorylation promotes the self-assembly of ? into tangles of PHF and straight filaments by neutralizing the inhibitory basic charges of the flanking regions. PMID:11381127

Alonso, Alejandra del C.; Zaidi, Tanweer; Novak, Michal; Grundke-Iqbal, Inge; Iqbal, Khalid

2001-01-01

419

Virtual Turing Machine 2  

NSDL National Science Digital Library

A Turing machine is theoretical computer consisting of a finite set of internal states, a finite alphabet that includes a blank symbol, and a finite set of instructions. It has a physical head and a physical infinitely long tape, which is divided into cells. The cell values consist of the alphabet. The tape has a finite number of non-blank cells. The head can read and write to the cells and move the tape one cell to the left and one cell to the right. The Virtual Turing Machine lets you input tape values and an instruction set to see the output of a turing machine.

Ming, Paul R.

420

Wind Engineering  

NASA Technical Reports Server (NTRS)

Dr. Jack Cermak, Director of Fluid Dynamics and Diffusion Laboratory, developed the first wind tunnel to simulate the changing temperatures, directions and velocities of natural winds. In this work, Cermak benefited from NASA technology related to what is known as the atmospheric boundary layer (ABL).

1983-01-01

421

New Horizons for Offshore Wind Energy: Shifting Paradigms and Challenges  

Microsoft Academic Search

The placing of wind turbines offshore is likely to lead to developments of the technology as far-reaching as those which turned the crude onshore machines of the early 1980s into the elegant giants of today. This article discusses the acute need of development of offshore wind energy converting systems. The development of different design techniques and the economics of these

T. S. BHATTI; D. P. KOTHARI

2005-01-01

422

Wind Energy Conversion Systems. A Unit of Instruction.  

ERIC Educational Resources Information Center

The number of secondary schools, colleges, and universities offering courses in wind energy machine construction, repair, and installation, continues to increase. It is the purpose of this unit to include the study of wind energy conversion systems (WECS) as an integral part of related vocational and technical curriculum materials. The unit's…

Greenwald, Martin

423

Stator winding leakage inductances determination using finite elements method  

Microsoft Academic Search

This paper presents a new method to establish the leakage inductances of AC machine stator winding using a numerical analyzing program based on the finite elements method. The 3D numerical analysis is used to determine the end winding leakage inductance. In order to eliminate the magnetic flux present in the space normally occupied by the rotor, when the rotor is

O. Chiver; E. Micu; C. Barz

2008-01-01

424

Post-Assembly Magnetization of Rare-Earth Fractional-Slot Surface Permanent-Magnet Machines Using a Two-Shot Method  

Microsoft Academic Search

This paper studies the post-assembly magnetization of a fractional-slot, concentrated winding brushless rare-earth surface permanent-magnet machine with six rotor poles and nine stator slots. In the paper, the simulation method is discussed, and it is illustrated that it is possible to fully magnetize the machine after assembly using two pulses of the winding (\\

Min-Fu Hsieh; Yao-Min Lien; David G. Dorrell

2011-01-01

425

PRIMA (Prediction Intelligent Machine) is a software platform for testing of advanced statistical  

E-print Network

Overview ARGUS1 PRIMA (Prediction Intelligent Machine) is a software platform for testing for systematic testing and comparison of different computational learning algorithms. For wind power point for the forecasting errors. In tests on real-world data from two large-scale wind farms in the U.S. Midwest, results

Kemner, Ken

426

Theory of Molecular Machines. I. Channel Capacity of Molecular Machines  

E-print Network

Theory of Molecular Machines. I. Channel Capacity of Molecular Machines running title: Channel Capacity of Molecular Machines Thomas D. Schneider version = 5.76 of ccmm.tex 2004 Feb 3 Version 5.67 was submitted 1990 December 5 Schneider, T. D. (1991). Theory of molecular machines. I. Channel capacity

Schneider, Thomas D.

427

Speech Recognition in Machines 785 Speech Recognition in Machines  

E-print Network

Speech Recognition in Machines 785 Speech Recognition in Machines Over the past several decades (speech recognition systems) human speech. We concentrate on speech recognition systems in this section. Speech recognition by machine refers to the capability of a machine to convert human speech to a textual

Liebling, Michael

428

16. Interior, Machine Shop, Roundhouse Machine Shop Extension, Southern Pacific ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. Interior, Machine Shop, Roundhouse Machine Shop Extension, Southern Pacific Railroad Carlin Shops, view to south (90mm lens). Note the large segmental-arched doorway to move locomotives in and out of Machine Shop. - Southern Pacific Railroad, Carlin Shops, Roundhouse Machine Shop Extension, Foot of Sixth Street, Carlin, Elko County, NV

429

Universal Developer Platform for MachinePlatform for Machine  

E-print Network

1 Universal Developer Platform for MachinePlatform for Machine Control Applications Hansjoerg will need some things: · Senses · Means June 24-26, 2008 ETH Zurich #12;2 And for Machine Control? June 24 ETH Zurich Conclusion: big effort for things that have little to do with Machine Control Multi

430

Curious and Creative Machines  

Microsoft Academic Search

st -grade elementary school children. In the school's gymnasium hall, a few dozen 6-year-olds gathered enthusiastically around a few shiny machines with plenty of sensors and actuators, demonstrating patterns of locomotion. \\

Hod Lipson

2006-01-01

431

Design of Vitrification Machine  

E-print Network

and unreliable process. Moreover, there is a lack of standardization in the methods for preparing cells and biological material for the vitrification process. The purpose of the Vitrification Machine is to greatly simplify the process by making it faster, more...

McDonald, Todd William

2009-11-30

432

Protein Thin Film Machines  

E-print Network

We report the first example of microcantilever beams that are reversibly driven by protein thin film machines fuelled by cycling the salt concentration of the surrounding solution. We also show that upon the same salinity ...

Federici, Stefania

433

Machine For Grinding Fog  

E-print Network

Machine For Grinding Fog, an exhibition of stop motion animated films, revolves around three primary concerns: relationships, psychological or subjective reality, and relativity. Rooted within concerns of faith, personal ethics, and a re...

Ward, Nicholas Adam

2010-04-30

434

Positive Linear Function Machine  

NSDL National Science Digital Library

Students investigate linear functions with positive slopes by trying to guess the slope and intercept from inputs and outputs. Positive Linear Function Machine is one of the Interactivate assessment explorers.

435

Designing Sociable Machines  

Microsoft Academic Search

Sociable machines are a blend of art, science, and engineering. We highlight how insights from these disciplines have helped us to address a few key design issues for building expressive humanoid robots that interact with people in a social manner.

Cynthia Breazeal

436

The SERI wind energy program  

NASA Astrophysics Data System (ADS)

The widespread implementation of wind energy is supported by conducting research and development studies. The activities fall into three general areas-planning, management and analysis; advanced and innovative concepts; and information development. In the first area, the work conducted relates to economic, application, legal, social and environmental studies which are generic and could be applied to a wide range of machine size and type. The second area of responsibility lies with the directing and managing of advanced and innovative concepts--those high risk concepts that offer the potential of improving upon the cost of energy of conventional systems and of increasing the wide spread implementation of wind systems into populated areas. The third area of responsibility relates to the development of informational documents which are designed for specific audiences. This activity generally supports the Solar Energy Information Data Bank in their efforts to provide general information in response to inquiries on wind energy.

Vas, I. E.

437

Localizing and Extracting Filament Distributions from Microscopy Images  

PubMed Central

Detailed quantitative measurements of biological filament networks represent a crucial step in understanding architecture and structure of cells and tissues, which in turn explain important biological events such as wound healing and cancer metastases. Confocal microscope images of biological specimens marked for different structural proteins constitute an important source for observing and measuring meaningful parameters of biological networks. Unfortunately, current efforts at quantitative estimation of architecture and orientation of biological filament networks from microscopy images are predominantly limited to visual estimation and indirect experimental inference. Here we describe a new method for localizing and extracting filament distributions from 2D confocal microscopy images. The method combines a filter-based detection of pixels likely to contain a filament with a constrained reverse diffusion-based approach for localizing the filaments centerlines. We show with qualitative and quantitative experiments, using both simulated and real data, that the new method can provide more accurate centerline estimates of filament in comparison to other approaches currently available. In addition, we show the algorithm is more robust with respect to variations in the initial filter-based filament detection step often used. We demonstrate the application of the method in extracting quantitative parameters from an experiment that seeks to quantify the effects of carbon nanotubes on actin cytoskeleton in live HeLa cells. We show that their presence can disrupt the overall actin cytoskeletal organization in such cells. PMID:23458491

Basu, Saurav; Dahl, Kris Noel; Rohde, Gustavo Kunde

2013-01-01

438

Filamentous smooth muscle myosin is regulated by phosphorylation  

SciTech Connect

The enzymatic activity of filamentous dephosphorylated smooth muscle myosin has been difficult to determine because the polymer disassembles to the folded conformation in the presence of MgATP. Monoclonal antirod antibodies were used here to fix dephosphorylated myosin in the filamentous state. The steady-state actin-activated ATPase of phosphorylated filaments was 30-100-fold higher than that of antibody-stabilized dephosphorylated filaments, suggesting that phosphorylation can activate ATPase activity independent of changes in assembly. The degree of regulation may exceed 100-fold, because steady-state measurements slightly overestimate the rate of product release from dephosphorylated filaments. Single-turnover experiments in the absence of actin showed that although dephosphorylated folded myosin released products at the low rate of 0.0005 s-1. The addition of actin did not increase this rate to any appreciable extent. Dephosphorylated filaments and dephosphorylated heavy meromyosin thus have similar low rates of phosphate release both in the presence and absence of actin. These results show that light chain phosphorylation alone, without invoking other mechanisms, is an effective switch for regulating the activity of smooth muscle myosin filaments.

Trybus, K.M. (Brandeis Univ., Waltham, MA (USA))

1989-12-01

439

Disappearance of a coronal hole induced by a filament activation  

NASA Astrophysics Data System (ADS)

We present a rare observation of direct magnetic interaction between an activating filament and a coronal hole (CH). The filament was a quiescent one located at the northwest of the CH. It underwent a nonradial activation, during which filament material constantly fell and intruded into the CH. As a result, the CH was clearly destroyed by the intrusion. Brightenings appeared at the boundaries and in the interior of the CH, meanwhile, its west boundaries began to retreat and the area gradually shrank. It is noted that the CH went on shrinking after the end of the intrusion and finally disappeared entirely. Following the filament activation, three coronal dimmings (D1–D3) were formed, among which D1 and D2 persisted throughout the complete disappearance of the CH. The derived coronal magnetic configuration shows that the filament was located below an extended loop system, which obviously linked D1 to D2. By extrapolating this result, our observations imply that the interaction between the filament and the CH involved direct intrusion of the filament material to the CH and the disappearance of the CH might be due to interchange reconnection between the expanding loop system and the CH's open field.

Ma, Lin; Qu, Zhong-Quan; Yan, Xiao-Li; Xue, Zhi-Ke

2014-11-01

440

How ion binding affects actin filament stability and flexural rigidity  

NASA Astrophysics Data System (ADS)

Actin filaments are semi-flexible biopolymers essential for the mechanical support and cell motility. Ions strongly affect actin polymerization and the flexibility of actin filaments; however, the molecular basis for how ions are coupled to the mechanics of actin filaments remains elusive. Here, we demonstrate a linkage between cation binding and both actin filament polymerization and flexural rigidity. Our results show that the thermodynamic stability and flexural rigidity of actin filament increase with cation concentration in a manner that implicates specific cation binding as opposed to general electrostatic screening. Using structural bioinformatics, we identify two distinct cation-binding sites within the F-actin structure that help explain how specific cation binding is linked to actin polymerization and flexural rigidity. Site-specific substitution of a charged amino acid residue at one of the sites modulates the cation concentration-dependence of filament bending stiffness, consistent with a bound cation at this site increasing the flexural rigidity of actin filaments. Mutation of a charged amino acid at the other site causes ``polymerization incompetent'' G-actin.

Kang, Hyeran; Bradley, Michael; McCullough, Brannon; Pierre, Anaëlle; Grintsevich, Elena; de La Cruz, Enrique

2012-02-01

441

Proper horizontal photospheric flows below an eruptive filament  

NASA Astrophysics Data System (ADS)

An analysis of the proper motions using SDO/HMI continuum images with the new version of the coherent structure tracking (CST) algorithm developed to track the granules as well as the large scale photospheric flows, was perfomed during three hours in a region containing a large filament channel on September 17, 2010. Supergranules were idenfied in the filament channel. Diverging flows inside the supergranules are similar in and out the filament channel. Using corks, we derived the passive scalar points and produced maps of cork distribution. The anchorage structures with the photosphere (feet) of the filament are located in the areas of converging flows with accumulations of corks. Averaging the velocity vectors for each latitude we defined a profile of the differential rotation. We conclude that the coupling between the convection and magnetic field in the photosphere is relatively strong. The filament experienced the convection motions through its feet. On a large scale point-of-view the differential rotation induced a shear of 0.1 km/s in the filament. On a small scale point-of-view convection motions favored the interaction/cancellation of the parasitic polarities at the base of the feet with the surrounding network explaining the brightenings,/jets and the eruption that were observed in the EUV filament.

Schmieder, Brigitte; Mein, Pierre; Mein, Nicole; Roudier, Thierry; Chandra, Ramseh

442

MUSE discovers perpendicular arcs in Cen A inner filament  

E-print Network

Evidence of AGN interaction with the intergalactic medium is observed in some galaxies and many cool core clusters. Radio-jets are suspected to dig large cavities into the surrounding gas. In most cases, very large optical filaments (several kpc) are also seen all around the central galaxy. The origin of these filaments is still not understood. Star forming regions are sometimes observed inside the filaments and are interpreted as evidence of positive feedback (AGN-triggered star formation). Cen A is a very nearby galaxy with huge optical filaments aligned with AGN radio-jet direction. Here, we search for line ratio variations along the filaments, kinematic evidence of shock-broadend line widths and large scale dynamical structures. We observe a 1'x1' region around the inner filament of Cen A with MUSE on the VLT during the Science Verification period. The brightest lines are the Halpha, [NII], [OIII] and [SII]. MUSE shows that the filaments are made of clumpy structures inside a more diffuse medium aligned w...

Hamer, Stephen; Combes, Francoise; Salomé, Quentin

2014-01-01

443

Human-machine interactions  

SciTech Connect

Digital technology utilizing a cognitive model based on human naturalistic decision-making processes, including pattern recognition and episodic memory, can reduce the dependency of human-machine interactions on the abilities of a human user and can enable a machine to more closely emulate human-like responses. Such a cognitive model can enable digital technology to use cognitive capacities fundamental to human-like communication and cooperation to interact with humans.

Forsythe, J. Chris (Sandia Park, NM); Xavier, Patrick G. (Albuquerque, NM); Abbott, Robert G. (Albuquerque, NM); Brannon, Nathan G. (Albuquerque, NM); Bernard, Michael L. (Tijeras, NM); Speed, Ann E. (Albuquerque, NM)

2009-04-28

444

The Lisp Machine manual  

Microsoft Academic Search

This 471-page, softcover manual describes the programming language and software environment of the Lisp Machine developed at M.I.T.'s Artificial Intelligence Laboratory over the past 8 years. The Lisp Machine is the result of a successful experiment in computer science: a distributed computing system consisting of a network of powerful 32-bit personal computers, implemented with custom hardware and software as complete,

Daniel Weinreb; David Moon

1981-01-01

445

Working with simple machines  

NASA Astrophysics Data System (ADS)

A set of examples is provided that illustrate the use of work as applied to simple machines. The ramp, pulley, lever and hydraulic press are common experiences in the life of a student, and their theoretical analysis therefore makes the abstract concept of work more real. The mechanical advantage of each of these systems is also discussed so that students can evaluate their usefulness as machines.

Norbury, John W.

2006-11-01

446

Design a Flying Machine  

NSDL National Science Digital Library

The purpose of this activity is for the students to draw a design for their own flying machine. They will apply their knowledge of aircraft design and the forces acting on them. The students will start with a brainstorming activity where they come up with creative uses for every day objects. They will then use their creativity and knowledge of airplanes to design their own flying machine.

Integrated Teaching And Learning Program

447

Metalworking and machining fluids  

Microsoft Academic Search

Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and\\/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and\\/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction,

Ali Erdemir; Frank Sykora; Mark Dorbeck

2010-01-01

448

Weka Machine Learning Project  

NSDL National Science Digital Library

If you are inspired to try the process, the Weka Machine Learning Project from Waikato University offers open source software that can be used for data mining tasks. Visitors can also find the projects 1993 to 2006 publications, many of which are available for free in as PDFs. The "related" section offers a number of links to further information on topics such as artificial intelligence and machine learning.

2008-01-10

449

Metalworking and machining fluids  

DOEpatents

Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

Erdemir, Ali (Naperville, IL); Sykora, Frank (Caledon, ON, CA); Dorbeck, Mark (Brighton, MI)

2010-10-12

450

Driven Wave Machine Model  

NSDL National Science Digital Library

The Driven Wave Machine model simulates a wave machine driven by a sinusoidal oscillator. The machine consists of horizontal bars welded to a torsion rod that is perpendicular to the bars. The simulation allows the user to change the number of bars, the drive frequency, and the boundary conditions. The simulation also allows the user to change the lengths of the bars, thereby simulating the effect of a wave propagating in a non-uniform medium. The Driven Wave Machine model is a supplemental simulation for the article "Standing Waves in a Nonuniform Medium" by Paul Gluck in The Physics Teacher 49(2), 76-77 (2011) and has been approved by the authors and The Physics Teacher editor. The Driven Wave Machine model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_mech_osc_chains_DrivenWaveMachine.jar file will run the program if Java is installed.

Christian, Wolfgang

2010-11-09

451

Wave Machine Model  

NSDL National Science Digital Library

This model simulates the wave generating machine created by John Shive at Bell Laboratories and made famous by the Similarities in Wave Behavior film. The machine consists of horizontal cross-bars welded to a central wire spine that is perpendicular to the bars. The spine was constructed so that it can freely twist, allowing the cross-bars to produce wave-like patterns. The simulation allows various pulse shapes to be sent down the machine by selecting a function for the twist of the first rod or by dragging the first rod. The far end of the wave machine can be free or fixed, which changes the nature of the reflected wave. Change the lengths of the bars to simulate the effect of a wave propagating in a non-uniform medium. The original film that introduced Dr. Shive's wave generating machine can be viewed at no cost: Film: Similarities of Wave Behavior (AT&T Archives and History Collection). The Wave Machine model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive.

Christian, Wolfgang

2014-06-13

452

Mechanism of interaction of Dictyostelium severin with actin filaments  

PubMed Central

Severin, a 40,000-dalton protein from Dictyostelium that disassembles actin filaments in a Ca2+ -dependent manner, was purified 500-fold to greater than 99% homogeneity by modifications of the procedure reported by Brown, Yamamoto, and Spudich (1982. J. Cell Biol. 93:205-210). Severin has a Stokes radius of 29 A and consists of a single polypeptide chain. It contains a single methionyl and five cysteinyl residues. We studied the action of severin on actin filaments by electron microscopy, viscometry, sedimentation, nanosecond emission anisotropy, and fluorescence energy transfer spectroscopy. Nanosecond emission anisotropy of fluoresence-labeled severin shows that this protein changes its conformation on binding Ca2+. Actin filaments are rapidly fragmented on addition of severin and Ca2+, but severin does not interact with actin filaments in the absence of Ca2+. Fluorescence energy transfer measurements indicate that fragmentation of actin filaments by severin leads to a partial depolymerization (t1/2 approximately equal to 30 s). Depolymerization is followed by exchange of a limited number of subunits in the filament fragments with the disassembled actin pool (t1/2 approximately equal to 5 min). Disassembly and exchange are probably restricted to the ends of the filament fragments since only a few subunits in each fragment participate in the disassembly or exchange process. Steady state hydrolysis of ATP by actin in the presence of Ca2+-severin is maximal at an actin: severin molar ratio of approximately 10:1, which further supports the inference that subunit exchange is limited to the ends of actin filaments. The observation of sequential depolymerization and subunit exchange following the fragmentation of actin by severin suggests that severin may regulate site-specific disassembly and turnover of actin filament arrays in vivo. PMID:6897549

1982-01-01

453

Extensive Non-Radiative Filaments in the Cygnus Loop  

NASA Astrophysics Data System (ADS)

We have obtained CCD images in H? covering the northern perimeter of the Cygnus Loop, using the wide-field imaging capability of the Burrell Schmidt telescope and S2KA chip at Kitt Peak. Mosaics of these images reveal a near-continuous chain of non-radiative filaments extending about 90deg around the northern portion of the Loop. These faint filaments have an extremely thin, delicate morphology, surely the result of thin sheets of emission viewed edge-on, and are located several arcmin outside the familiar bright, radiative filaments. Non-radiative filaments emit almost exclusively in Balmer lines, and delineate the present position of primary supernova shocks (e.g. Hester, Raymond, and Danielson, Ap J Lett, 303, L17). The non-radiative filaments we have observed appear to trace the outer edge of X-ray emission, as observed with lower resolution from the Einstein IPC by Ku et al., (Ap J, 278, 615). In the limited field where our imagery overlaps with Ku et al's HRI images, the optical filaments coincide precisely with the leading edge of the X-ray emission. A few of the non-radiative filaments are faintly visible on the POSS plates, and crude comparison with our images indicates obvious proper motions ~ 0.1\\ arcsec yr(-1) . The Balmer line widths in non-radiative filaments give a direct measure of the shock velocity, so the combination of high resolution spectroscopy and precise proper motion measurement could lead to a distance determination independent of the classic Hubble-Minkowski measurement of 770 pc based on kinematics of the bright, radiative filaments (Rev Mod Phys, 30, 1048). This work was supported in part by NSF grant AST-9114935 and by the W.M. Keck Foundation through the Keck Northeast Astronomy Consortium.

Hanson, G. J.; Winkler, P. F.

1992-12-01

454

NSTX Filament Preionization and Glow Discharge Cleaning Systems  

SciTech Connect

Initial NSTX GDC experiments were performed with one moveable anode and a biased filament preionization system that allowed D2 and He Glow Discharge breakdowns at the actual operating pressure, voltage and current. The biased filament system was also operated continuously during ohmic operations, and used to reduce volt-sec consumption for February 1999 plasma discharges up to 280 KA. An upgraded system has been installed with 2 fixed wall anodes and 3 biased filaments; 2 on the mid-plane and one in the divertor region; all separately controllable remotely using a PLC system. Recent applications include assisting in preionization for 800 KA plasma discharges.

H.W. Kugel, W. Blanchard, G. D'Amico, R. Gernhardt, T. Provost

1999-11-01

455

Spectroscopic characterization of femtosecond laser filament in argon gas  

SciTech Connect

We report a spectroscopic approach to measure the plasma density and electron temperature inside a filament created by an intense femtosecond laser pulse in atmospheric pressure argon gas. The technique relies on the proportionality between the Stark broadened argon fluorescence line width due to electron impact and the plasma density, while the electron temperature is determined from the well known Boltzmann plot. The obtained maximum plasma density is about 5.5x10{sup 16} cm{sup -3}, and the electron temperature is about 5800 K. Our method provides a promising and convenient way to characterize the filament for further understanding the fundamental physics and potential applications of filamentation.

Liu, W.; Bernhardt, J.; Theberge, F.; Chin, S. L.; Chateauneuf, M.; Dubois, J. [Institute of Modern Optics, Nankai University, Key Laboratory of Opto-electronic Information Science and Technology, Education Ministry of China, Tianjin 300071 (China); Centre d'Optique, Photonique et Laser (COPL) and Departement de physique, de genie physique et d'optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada); Defence Research and Development Canada--Valcartier, 2459 Pie-XI Blvd. North, Quebec, Quebec, G3J 1X5 Canada (Canada)

2007-08-01

456

Interaction of tropomyosin-troponin with actin filaments.  

PubMed

The assembly of actin filaments with tropomyosin-troponin was investigated by means of light scattering. Binding curves of tropomyosin-troponin [consisting of all three subunits (holotroponin)] and of tropomyosin-troponin-T-I to actin filaments were analyzed by separating the affinity of tropomyosin-troponin for actin filaments and the affinity for the end-to-end contact of tropomyosin molecules. Under the experimental conditions (42.4 degrees C, 300 mM KCl), tropomyosin-holotroponin in the absence of calcium and tropomyosin-troponin-T-I had similar affinities for actin filaments whereas tropomyosin-holotroponin in the presence of calcium was found to bind more weakly. Tropomyosin-holotroponin and tropomyosin-troponin-T-I bound about 200-300-fold more strongly to binding sites with adjacent tropomyosin-troponin units than to isolated sites on actin filaments. The equilibrium constant for isolated association with actin filaments was more than 2-fold higher for tropomyosin-holotroponin in the absence of calcium (15 400 M-1) and tropomyosin-troponin-T-I (17 500 M-1) than for tropomyosin-holotroponin in the presence of calcium (6600 M-1). Binding curves of mixtures of tropomyosin-holotroponin in the presence of calcium and of tropomyosin-troponin-T-I were measured and analyzed on the basis of a model of cooperative binding of two types of large ligands to a one-dimensional homogeneous lattice. The results provided information on the strength of the end-to-end contacts of tropomyosin-troponin units in different positions on an actin filament. It was found that a tropomyosin-troponin unit binds adjacently to another unit in a different position on an actin filament about 2-fold more weakly than adjacent to a unit in the same position. With the aid of these results, it was possible to obtain information of the equilibrium distribution of tropomyosin-troponin in the two positions on actin filaments. Generation of a sequence of tropomyosin-troponin units in a different position on actin filaments was found to be 4-fold less favored than elongation of an existing sequence (cooperativity parameter sigma = 1/4). Shifting of tropomyosin-troponin on actin filaments appears to be accompanied by small free-energy changes in the various interactions of the components of actin-tropomyosin-troponin filaments and not to be an all-or-none reaction PMID:6457636

Wegner, A; Walsh, T P

1981-09-15

457

Footpoint detection and mass-motion in chromospheric filaments  

NASA Astrophysics Data System (ADS)

A quiescent region on the Sun containing three filaments is used to study the properties of mass motion. This study determines if the footpoints or end-points of the filaments are the locations from where mass gets injected into the filaments. Several hypotheses have been put forth in the past to determine how a filament acquires mass. Trapping of coronal mass in the filament channel due to condensation (Martin, 1996) and injection of mass into the filaments during magnetic reconnection (Priest, et al., 1995) are some of the speculations. This study looks for indications for injection of mass via chromospheric footpoints. The data consists of blue (H?-0.5 Å) and red (H?+0.5 Å) wing high resolution H? images of the W29N37 region of the Sun taken on Oct 30, 2010, from 1200 - 1600 UT. The Dutch Open Telescope was used to obtain the data. The images are aligned and animated to see Doppler motion in the fibrils. Smaller fibrils merge to form longer ones; barbs appear and disappear in one of the long filaments and is seen moving along the length of the filament. A region with no typical filament-like absorption feature is observed to be continuously receiving mass. Fibrils appear to be converging from opposite sides along what appears to be a neutral line; mass motion is seen in these fibrils as well. An eruption occurs in a region of fibrils lumped together at the end of the first hour (1300 UT) followed by plage brightening at 1430 UT near one of the filament regions. Helioviewer (Panasenco, et al., 2011) is used for aligning the images; GIMP is used for precision alignment and animation. Each frame in the sequence is studied carefully to note changes in the filament regions. The footpoints of the filaments are determined by the changes observed in the position of the filament ‘legs’ in each frame. Variations in the magnetic polarity corresponding to changes observed in the chromosphere are analyzed using HMI magnetograms. Bright and dark points on the magnetogram surrounding the filaments are examined for possible locations of footpoints. The HMI images are overlaid with Stonyhurst grids and full disk H? images to improve the accuracy in determining the location of the footpoints.Abstract (2,250 Maximum Characters): A quiescent region on the Sun containing three filaments is used to study the properties of mass motion. This study determines if the footpoints or end-points of the filaments are the locations from where mass gets injected into the filaments. Several hypotheses have been put forth in the past to determine how a filament acquires mass. Trapping of coronal mass in the filament channel due to condensation (Martin, 1996) and injection of mass into the filaments during magnetic reconnection (Priest, et al., 1995) are some of the speculations. This study looks for indications for injection of mass via chromospheric footpoints. The data consists of blue (H?-0.5 Å) and red (H?+0.5 Å) wing high resolution H? images of the W29N37 region of the Sun taken on Oct 30, 2010, from 1200 - 1600 UT. The Dutch Open Telescope was used to obtain the data. The images are aligned and animated to see Doppler motion in the fibrils. Smaller fibrils merge to form longer ones; barbs appear and disappear in one of the long filaments and is seen moving along the length of the filament. A region with no typical filament-like absorption feature is observed to be continuously receiving mass. Fibrils appear to be converging from opposite sides along what appears to be a neutral line; mass motion is seen in these fibrils as well. An eruption occurs in a region of fibrils lumped together at the end of the first hour (1300 UT) followed by plage brightening at 1430 UT near one of the filament regions. Helioviewer (Panasenco, et al., 2011) is used for aligning the images; GIMP is used for precision alignment and animation. Each frame in the sequence is studied carefully to note changes in the filament regions. The footpoints of the filaments are determined by the changes observed in the position of the filament ‘legs’ in each frame

V, Aparna; Hardersen, P. S.; Martin, S. F.

2013-07-01

458

Gradient catastrophe and flutter in vortex filament dynamics  

NASA Astrophysics Data System (ADS)

Gradient catastrophe and flutter instability in the motion of a vortex filament within the localized induction approximation are analyzed. It is shown that the origin of this phenomenon is in the gradient catastrophe for the dispersionless Da Rios system which describes the motion of a filament with slow varying curvature and torsion. Geometrically, this catastrophe manifests as a rapid oscillation of a filament curve in a point that resembles the flutter of airfoils. Analytically, it is the elliptic umbilic singularity in the terminology of the catastrophe theory. It is demonstrated that its double scaling regularization is governed by the Painlevé-I equation.

Konopelchenko, B. G.; Ortenzi, G.

2011-10-01

459

HIERARCHICAL FRAGMENTATION OF THE ORION MOLECULAR FILAMENTS  

SciTech Connect

We present a high angular resolution map of the 850 {mu}m continuum emission of the Orion Molecular Cloud-3 (OMC 3) obtained with the Submillimeter Array (SMA); the map is a mosaic of 85 pointings covering an approximate area of 6.'5 Multiplication-Sign 2.'0 (0.88 Multiplication-Sign 0.27 pc). We detect 12 spatially resolved continuum sources, each with an H{sub 2} mass between 0.3-5.7 M {sub Sun} and a projected source size between 1400-8200 AU. All the detected sources are on the filamentary main ridge (n{sub H{sub 2}}{>=}10{sup 6} cm{sup -3}), and analysis based on the Jeans theorem suggests that they are most likely gravitationally unstable. Comparison of multi-wavelength data sets indicates that of the continuum sources, 6/12 (50%) are associated with molecular outflows, 8/12 (67%) are associated with infrared sources, and 3/12 (25%) are associated with ionized jets. The evolutionary status of these sources ranges from prestellar cores to protostar phase, confirming that OMC-3 is an active region with ongoing embedded star formation. We detect quasi-periodical separations between the OMC-3 sources of Almost-Equal-To 17''/0.035 pc. This spatial distribution is part of a large hierarchical structure that also includes fragmentation scales of giant molecular cloud ( Almost-Equal-To 35 pc), large-scale clumps ( Almost-Equal-To 1.3 pc), and small-scale clumps ( Almost-Equal-To 0.3 pc), suggesting that hierarchical fragmentation operates within the Orion A molecular cloud. The fragmentation spacings are roughly consistent with the thermal fragmentation length in large-scale clumps, while for small-scale cores it is smaller than the local fragmentation length. These smaller spacings observed with the SMA can be explained by either a helical magnetic field, cloud rotation, or/and global filament collapse. Finally, possible evidence for sequential fragmentation is suggested in the northern part of the OMC-3 filament.

Takahashi, Satoko; Ho, Paul T. P.; Su, Yu-Nung [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China)] [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Teixeira, Paula S. [Institut fuer Astrophysik, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180, Wien (Austria)] [Institut fuer Astrophysik, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180, Wien (Austria); Zapata, Luis A., E-mail: satoko_t@asiaa.sinica.edu.tw [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Morelia, Michoacan 58090 (Mexico)

2013-01-20

460

Organic Acid Production by Filamentous Fungi  

SciTech Connect

Many of the commercial production processes for organic acids are excellent examples of fungal biotechnology. However, unlike penicillin, the organic acids have had a less visible impact on human well-being. Indeed, organic acid fermentations are often not even identified as fungal bioprocesses, having been overshadowed by the successful deployment of the ?-lactam processes. Yet, in terms of productivity, fungal organic acid processes may be the best examples of all. For example, commercial processes using Aspergillus niger in aerated stirred-tank-reactors can convert glucose to citric acid with greater than 80% efficiency and at final concentrations in hundreds of grams per liter. Surprisingly, this phenomenal productivity has been the object of relatively few research programs. Perhaps a greater understanding of this extraordinary capacity of filamentous fungi to produce organic acids in high concentrations will allow greater exploitation of these organisms via application of new knowledge in this era of genomics-based biotechnology. In this chapter, we will explore the biochemistry and modern genetic aspects of the current and potential commercial processes for making organic acids. The organisms involved, with a few exceptions, are filamentous fungi, and this review is limited to that group. Although yeasts including Saccharomyces cerevisiae, species of Rhodotorula, Pichia, and Hansenula are important organisms in fungal biotechnology, they have not been significant for commercial organic acid production, with one exception. The yeast, Yarrowia lipolytica, and related yeast species, may be in use commercially to produce citric acid (Lopez-Garcia, 2002). Furthermore, in the near future engineered yeasts may provide new commercial processes to make lactic acid (Porro, Bianchi, Ranzi, Frontali, Vai, Winkler, & Alberghina, 2002). This chapter is divided into two parts. The first contains a review of the commercial aspects of current and potential large-scale processes for fungal organic acid production. The second presents a detailed review of current knowledge of the biochemistry and genetic regulation of organic acid biosynthesis. The organic acids considered are limited to polyfunctional acids containing one or more carboxyl groups, hydroxyl groups, or both, that are closely tied to central metabolic pathways. A major objective of the review is to link the biochemistry of organic acid production to the available genomic data.

Magnuson, Jon K.; Lasure, Linda L.

2004-05-03

461

A Direct Drive Wind Turbine HTS Generator  

Microsoft Academic Search

The wind turbine market is growing rapidly, and there has also been a trend toward ever increasing turbine rating. Most turbines to date has used geared high speed generators, but a history of gearbox reliability problems have turned many turbine manufacturers towards direct drive generators, which are very low speed, high torque, and therefore very large. Superconducting machines offer the

Clive Lewis; Jens Müller

2007-01-01

462

Superconductivity for Large Scale Wind Turbines  

SciTech Connect

A conceptual design has been completed for a 10MW superconducting direct drive wind turbine generator employing low temperature superconductors for the field winding. Key technology building blocks from the GE Wind and GE Healthcare businesses have been transferred across to the design of this concept machine. Wherever possible, conventional technology and production techniques have been used in order to support the case for commercialization of such a machine. Appendices A and B provide further details of the layout of the machine and the complete specification table for the concept design. Phase 1 of the program has allowed us to understand the trade-offs between the various sub-systems of such a generator and its integration with a wind turbine. A Failure Modes and Effects Analysis (FMEA) and a Technology Readiness Level (TRL) analysis have been completed resulting in the identification of high risk components within the design. The design has been analyzed from a commercial and economic point of view and Cost of Energy (COE) calculations have been carried out with the potential to reduce COE by up to 18% when compared with a permanent magnet direct drive 5MW baseline machine, resulting in a potential COE of 0.075 $/kWh. Finally, a top-level commercialization plan has been proposed to enable this technology to be transitioned to full volume production. The main body of this report will present the design processes employed and the main findings and conclusions.

R. Fair; W. Stautner; M. Douglass; R. Rajput-Ghoshal; M. Moscinski; P. Riley; D. Wagner; J. Kim; S. Hou; F. Lopez; K. Haran; J. Bray; T. Laskaris; J. Rochford; R. Duckworth

2012-10-12

463

Wind Energy Leasing Handbook  

E-print Network

Wind Energy Leasing Handbook Wind Energy Leasing Handbook E-1033 Oklahoma Cooperative Extension?..................................................................................................................... 31 What do wind developers consider in locating wind energy projects?............................................................................................ 37 How do companies and individuals invest in wind energy projects?....................................................................

Balasundaram, Balabhaskar "Baski"

464

The Knife Machine. Module 15.  

ERIC Educational Resources Information Center

This module on the knife machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers one topic: performing special operations on the knife machine (a single needle or multi-needle machine which sews and cuts at the same time). These components are provided: an introduction, directions, an objective,…

South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

465

Applications of the Connection Machine  

Microsoft Academic Search

The Connection Machine development effort was initiated in the belief that parallel processing and artificial intelligence could together accelerate the rate of progress toward truly intelligent machines. This progress is the result of the ease with which the machine can be programmed and the dramatic increase in compute power that the machine can bring to bear. The authors have been

David L. Waltz

1987-01-01

466

Harvesting Machine Census 1999 & 2001  

E-print Network

1 Harvesting Machine Census 1999 & 2001 231 Corstorphine Road Edinburgh EH12 7AT www.forestry.gov.uk FCTN001 SUMMARY This Technical Note contains information on the 1999 and 2001 harvesting machine machines, converted forwarders, etc., account for the remaining machines. In the 2001 census, 65

467

MACHINE MONITORING USING PROBABILITY THRESHOLDS  

E-print Network

MACHINE MONITORING USING PROBABILITY THRESHOLDS AND SYSTEM OPERATING CHARACTERISTICS Stephen M a discrete-part production machine, with the objective of effectively determining when to shut the machine analysis: a) There is an underlying time interval that characterizes the operation of the machine, most

Pollock, Stephen

468

Machine Learning Thomas G. Dietterich  

E-print Network

Machine Learning Thomas G. Dietterich Department of Computer Science Oregon State University Corvallis, OR 97331 1 Introduction Machine Learning is the study of methods for programming computers a computer system. A machine learning system can study recorded data and subsequent machine failures

469

Stochastic Optimization for Machine Learning  

E-print Network

Stochastic Optimization for Machine Learning ICML 2010, Haifa, Israel Tutorial by Nati Srebro Descent: formulation, analysis and use in machine learning · Learn about extensions and generalizations, and their Machine Learning counterparts Main Goal: Machine Learning is Stochastic Optimization #12;Outline

Powell, Warren B.

470

Interactive Machine Learning Mustafa Bilgic  

E-print Network

Interactive Machine Learning Mustafa Bilgic "Who We Are" Seminars IIT 9/24/2013 #12;Bio Bachelor Komurlu 2 #12;Research Interests Machine learning Interactive machine learning Statistical relational Diagnosis Recommender Systems Search Engines 4 #12;How Does a Machine Learn? There are many approaches

Heller, Barbara

471

Quadraphonic Wind  

NSDL National Science Digital Library

In this activity, learners discover how the extent of various wind speeds changes in each of the four quadrants around a hurricane. Learners use data from the 'present' location of Hurricane Bill (2009) to plot the distance of various wind speeds that extend from the center of the storm. This resource includes brief background information about hurricanes and forecasting as well as an explanation of the Hurricane Bill data used in this activity and how small increases in wind speed can cause increased potential for damage.

Service, National W.

2012-12-18

472

Wind Tunnel  

NSDL National Science Digital Library

Scientists use enormous wind tunnels to test the design of planes, helicopters, even the Space Shuttle. In this simulation activity, learners create a miniature wind tunnel test by blowing air with a fan or blow dryer through a large tube, then flying paper airplanes, helicopters and other folded paper models in the "wind." Unless the source of the air is a fan that stands on its own, for example, more than one person will be needed to do the activity.This activity can be combined with the Helicopter Twirl, Parachute Drop and Boomerang activities, also found on the Lawrence Hall of Science Kids Site.

Science, Lawrence H.

2009-01-01

473

Global Winds  

NSDL National Science Digital Library

On this worksheet, students examine a diagram of global winds and learn the position of the prevailing westerlies, the polar easterlies, the trade winds, the horse latitudes and the doldrums, and that together, the uneven heating of the planet by the Sun and the Coriolis Effect are responsible for the global wind belts. The resource is part of the teacher's guide accompanying the video, NASA Why Files: The Case of the Mysterious Red Light. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide.

474

Stellar Winds  

NASA Astrophysics Data System (ADS)

A "stellar wind" is the continuous, supersonic outflow of matter from the surface layers of a star. Our sun has a solar wind, driven by the gas-pressure expansion of the hot (T > 106 K) solar corona. It can be studied through direct in situ measurement by interplanetary spacecraft; but analogous coronal winds in more distant solar-type stars are so tenuous and transparent that that they are difficult to detect directly. Many more luminous stars have winds that are dense enough to be opaque at certain wavelengths of the star's radiation, making it possible to study their wind outflows remotely through careful interpretation of the observed stellar spectra. Red giant stars show slow, dense winds that may be driven by the pressure from magnetohydrodyanmic waves. As stars with initial mass up to 8 M ? evolve toward the Asymptotic Giant Branch (AGB), a combination of stellar pulsations and radiative scattering off dust can culminate in "superwinds" that strip away the entire stellar envelope, leaving behind a hot white dwarf stellar core with less than the Chandrasekhar mass of ˜ ?? 1. 4M ?. The winds of hot, luminous, massive stars are driven by line-scattering of stellar radiation, but such massive stars can also exhibit superwind episodes, either as Red Supergiants or Luminous Blue Variable stars. The combined wind and superwind mass loss can strip the star's hydrogen envelope, leaving behind a Wolf-Rayet star composed of the products of earlier nuclear burning via the CNO cycle. In addition to such direct effects on a star's own evolution, stellar winds can be a substantial source of mass, momentum, and energy to the interstellar medium, blowing open large cavities or "bubbles" in this ISM, seeding it with nuclear processed material, and even helping trigger the formation of new stars, and influencing their eventual fate as white dwarves or core-collapse supernovae. This chapter reviews the properties of such stellar winds, with an emphasis on the various dynamical driving processes and what they imply for key wind parameters like the wind flow speed and mass loss rate.

Owocki, Stan

475

Inter-cluster Filaments of Galaxies Programme: Abundance and Distribution of Filaments in the 2dFGRS Catalogue  

E-print Network

Filaments of galaxies are known to stretch between galaxy clusters at all redshifts in a complex manner. In this Letter, we present an analysis of the frequency and distribution of inter-cluster galaxy filaments selected from the 2dF Galaxy Redshift Survey. Out of 805 cluster-cluster pairs, we find at least 40 per cent have bone-fide filaments. We introduce a filament classification scheme and cast the filaments into several types according to their visual morphology: straight (lying on the cluster-cluster axis; 37 per cent), warped or curved (lying off the cluster-cluster axis; 33 per cent), sheets (planar configurations of galaxies; 3 per cent), uniform (1 per cent) and irregular (26 per cent). We find that straight filaments are more likely to reside between close cluster pairs and they become more curved with increasing cluster separation. This curving is toward a larger mass concentration in general. We also show that the more massive a cluster is, the more likely it is to have a larger number of filaments. Our results are found to be consistent with a Lambda cold dark matter cosmology.

Kevin A. Pimbblet; Michael J. Drinkwater; Mary C. Hawkrigg

2004-09-24

476

DFIG-based wind farm electromagnetic dynamic model and impact on protection relay of transmission network  

Microsoft Academic Search

A DFIG-based wind generator electromagnetic transient model is established on the RTDS platform in this paper. Stator flux oriented vector control scheme is adopted to achieve power decoupling control in the DFIG based wind model. In order to research the impact of the wind farm on the existing protection relay of the network, this paper establishes single machine electromagnetic dynamic

Guanghui Li; Baohui Zhang; Jin Wang; Zhiqian Bo; Tony Yip; David Writer; Yu-ming Lei

2011-01-01

477

Improved Crowbar Control Strategy of DFIG Based Wind Turbines for Grid Fault Ride-Through  

Microsoft Academic Search

Nowadays, the most widely used variable speed machine for wind turbine above 1 MW is the doubly fed induction generator (DFIG). As the wind power penetration continues to increase, wind turbines are required to provide Low Voltage Ride-Through (LVRT) capability. Crowbars are commonly used to protect the power converters during voltage dips. Its main drawback is that the DFIG absorbs

Ling Peng; Bruno Francois; Yongdong Li

2009-01-01