Theoretical analysis of transcranial Hall-effect stimulation based on passive cable model

NASA Astrophysics Data System (ADS)

Yuan, Yi; Li, Xiao-Li

2015-12-01

Transcranial Hall-effect stimulation (THS) is a new stimulation method in which an ultrasonic wave in a static magnetic field generates an electric field in an area of interest such as in the brain to modulate neuronal activities. However, the biophysical basis of simulating the neurons remains unknown. To address this problem, we perform a theoretical analysis based on a passive cable model to investigate the THS mechanism of neurons. Nerve tissues are conductive; an ultrasonic wave can move ions embedded in the tissue in a static magnetic field to generate an electric field (due to Lorentz force). In this study, a simulation model for an ultrasonically induced electric field in a static magnetic field is derived. Then, based on the passive cable model, the analytical solution for the voltage distribution in a nerve tissue is determined. The simulation results showthat THS can generate a voltage to stimulate neurons. Because the THS method possesses a higher spatial resolution and a deeper penetration depth, it shows promise as a tool for treating or rehabilitating neuropsychiatric disorders. Project supported by the National Natural Science Foundation of China (Grant Nos. 61273063 and 61503321), the China Postdoctoral Science Foundation (Grant No. 2013M540215), the Natural Science Foundation of Hebei Province, China (Grant No. F2014203161), and the Youth Research Program of Yanshan University, China (Grant No. 02000134).

Study of Thermomechanical Properties of The Epoxy-Impregnated Cable Composite for a 15 T Nb3Sn Dipole Demonstrator

NASA Astrophysics Data System (ADS)

Li, Pei; Krave, Steve; Zlobin, Alexander

2017-12-01

The knowledge of the thermomechanical properties of the composite of cable/insulation/epoxy impregnation are important for the design, fabrication and operation of superconducting accelerator magnets. As a part of the 15 T dipole magnet development at Fermi National Accelerator Laboratory (FNAL), we studied the thermomechanical properties of cable stack that represents the cable composites in the 15 T dipole. The measurements include thermal contraction and strain-stress characterization under compressive load along the principal directions. The cable stack samples show hysteresis behaviour in loading-unloading cycles, which is found to be most dramatic along the azimuthal direction. Also, the choice of insulation material/procedure is found to strongly impact the bonding between cables and epoxy/cable layers. The cable stacks measured in this study use E-glass tape wrapping insulation and show weaker bonding to cables than similar cable stacks using S-2 glass sleeves insulation previously studied.

Multi-source micro-friction identification for a class of cable-driven robots with passive backbone

NASA Astrophysics Data System (ADS)

Tjahjowidodo, Tegoeh; Zhu, Ke; Dailey, Wayne; Burdet, Etienne; Campolo, Domenico

2016-12-01

This paper analyses the dynamics of cable-driven robots with a passive backbone and develops techniques for their dynamic identification, which are tested on the H-Man, a planar cabled differential transmission robot for haptic interaction. The mechanism is optimized for human-robot interaction by accounting for the cost-benefit-ratio of the system, specifically by eliminating the necessity of an external force sensor to reduce the overall cost. As a consequence, this requires an effective dynamic model for accurate force feedback applications which include friction behavior in the system. We first consider the significance of friction in both the actuator and backbone spaces. Subsequently, we study the required complexity of the stiction model for the application. Different models representing different levels of complexity are investigated, ranging from the conventional approach of Coulomb to an advanced model which includes hysteresis. The results demonstrate each model's ability to capture the dynamic behavior of the system. In general, it is concluded that there is a trade-off between model accuracy and the model cost.

Brillouin distributed temperature sensing system for monitoring of submarine export cables of off-shore wind farms

NASA Astrophysics Data System (ADS)

Marx, Benjamin; Rath, Alexander; Kolm, Frederick; Schröder, Andreas; Buntebarth, Christian; Dreß, Albrecht; Hill, Wieland

2016-05-01

For high-voltage cables, the maximum temperature of the insulation must never be exceeded at any location and at any load condition. The local temperatures depend not only on the cable design and load history, but also on the local thermal environment of the cable. Therefore, distributed temperature monitoring of high-voltage cables is essential to ensure the integrity of the cable at high load. Especially, the load of the export cables of wind farms varies strongly in dependence on weather conditions. In this field study, we demonstrate the measurement performance of a new, robust Brillouin distributed temperature sensing system (Brillouin-DTS). The system is based on spontaneous Brillouin scattering and does not require a fibre loop. This is essential for long submarine high-voltage cables, where normally no loop can be formed in the seabed. It is completely passively cooled and does not contain any moving or wearing parts. The instrument is dedicated for use in industrial and other rough environments. With a measuring time below 10 min, the temperature resolution is better than 1 °C for distances up to 50 km. In the field study, the submarine export cable of an off-shore wind farm has been monitored. The temperature profile of the export cable shows several hot spots, mostly located at cable joints, and also several cold spots.

OTEC riser cable model and prototype testing

NASA Astrophysics Data System (ADS)

Kurt, J. P.; Schultz, J. A.; Roblee, L. H. S.

1981-12-01

Two different OTEC riser cables have been developed to span the distance between a floating OTEC power plant and the ocean floor. The major design concerns for a riser cable in the dynamic OTEC environment are fatigue, corrosion, and electrical/mechanical aging of the cable components. The basic properties of the cable materials were studied through tests on model cables and on samples of cable materials. Full-scale prototype cables were manufactured and were tested to measure their electrical and mechanical properties and performance. The full-scale testing was culminated by the electrical/mechanical fatigue test, which exposes full-scale cables to simultaneous tension, bending and electrical loads, all in a natural seawater environment.

Subsea Cable Tracking by Autonomous Underwater Vehicle with Magnetic Sensing Guidance.

PubMed

Xiang, Xianbo; Yu, Caoyang; Niu, Zemin; Zhang, Qin

2016-08-20

The changes of the seabed environment caused by a natural disaster or human activities dramatically affect the life span of the subsea buried cable. It is essential to track the cable route in order to inspect the condition of the buried cable and protect its surviving seabed environment. The magnetic sensor is instrumental in guiding the remotely-operated vehicle (ROV) to track and inspect the buried cable underseas. In this paper, a novel framework integrating the underwater cable localization method with the magnetic guidance and control algorithm is proposed, in order to enable the automatic cable tracking by a three-degrees-of-freedom (3-DOF) under-actuated autonomous underwater vehicle (AUV) without human beings in the loop. The work relies on the passive magnetic sensing method to localize the subsea cable by using two tri-axial magnetometers, and a new analytic formulation is presented to compute the heading deviation, horizontal offset and buried depth of the cable. With the magnetic localization, the cable tracking and inspection mission is elaborately constructed as a straight-line path following control problem in the horizontal plane. A dedicated magnetic line-of-sight (LOS) guidance is built based on the relative geometric relationship between the vehicle and the cable, and the feedback linearizing technique is adopted to design a simplified cable tracking controller considering the side-slip effects, such that the under-actuated vehicle is able to move towards the subsea cable and then inspect its buried environment, which further guides the environmental protection of the cable by setting prohibited fishing/anchoring zones and increasing the buried depth. Finally, numerical simulation results show the effectiveness of the proposed magnetic guidance and control algorithm on the envisioned subsea cable tracking and the potential protection of the seabed environment along the cable route.

Subsea Cable Tracking by Autonomous Underwater Vehicle with Magnetic Sensing Guidance

PubMed Central

Xiang, Xianbo; Yu, Caoyang; Niu, Zemin; Zhang, Qin

2016-01-01

The changes of the seabed environment caused by a natural disaster or human activities dramatically affect the life span of the subsea buried cable. It is essential to track the cable route in order to inspect the condition of the buried cable and protect its surviving seabed environment. The magnetic sensor is instrumental in guiding the remotely-operated vehicle (ROV) to track and inspect the buried cable underseas. In this paper, a novel framework integrating the underwater cable localization method with the magnetic guidance and control algorithm is proposed, in order to enable the automatic cable tracking by a three-degrees-of-freedom (3-DOF) under-actuated autonomous underwater vehicle (AUV) without human beings in the loop. The work relies on the passive magnetic sensing method to localize the subsea cable by using two tri-axial magnetometers, and a new analytic formulation is presented to compute the heading deviation, horizontal offset and buried depth of the cable. With the magnetic localization, the cable tracking and inspection mission is elaborately constructed as a straight-line path following control problem in the horizontal plane. A dedicated magnetic line-of-sight (LOS) guidance is built based on the relative geometric relationship between the vehicle and the cable, and the feedback linearizing technique is adopted to design a simplified cable tracking controller considering the side-slip effects, such that the under-actuated vehicle is able to move towards the subsea cable and then inspect its buried environment, which further guides the environmental protection of the cable by setting prohibited fishing/anchoring zones and increasing the buried depth. Finally, numerical simulation results show the effectiveness of the proposed magnetic guidance and control algorithm on the envisioned subsea cable tracking and the potential protection of the seabed environment along the cable route. PMID:27556465

47 CFR 36.153 - Assignment of Cable and Wire Facilities (C&WF) to categories.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 2 2014-10-01 2014-10-01 false Assignment of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.153 Assignment of Cable and Wire Facilities (C&WF) to categories. (a) Cable consists of: Aerial cable, underground cable, buried cable, submarine cable, deep sea...

47 CFR 36.153 - Assignment of Cable and Wire Facilities (C&WF) to categories.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 2 2012-10-01 2012-10-01 false Assignment of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.153 Assignment of Cable and Wire Facilities (C&WF) to categories. (a) Cable consists of: Aerial cable, underground cable, buried cable, submarine cable, deep sea...

47 CFR 36.153 - Assignment of Cable and Wire Facilities (C&WF) to categories.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 2 2013-10-01 2013-10-01 false Assignment of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.153 Assignment of Cable and Wire Facilities (C&WF) to categories. (a) Cable consists of: Aerial cable, underground cable, buried cable, submarine cable, deep sea...

Enhanced damping for bridge cables using a self-sensing MR damper

NASA Astrophysics Data System (ADS)

Chen, Z. H.; Lam, K. H.; Ni, Y. Q.

2016-08-01

This paper investigates enhanced damping for protecting bridge stay cables from excessive vibration using a newly developed self-sensing magnetorheological (MR) damper. The semi-active control strategy for effectively operating the self-sensing MR damper is formulated based on the linear-quadratic-Gaussian (LQG) control by further considering a collocated control configuration, limited measurements and nonlinear damper dynamics. Due to its attractive feature of sensing-while-damping, the self-sensing MR damper facilitates the collocated control. On the other hand, only the sensor measurements from the self-sensing device are employed in the feedback control. The nonlinear dynamics of the self-sensing MR damper, represented by a validated Bayesian NARX network technique, are further accommodated in the control formulation to compensate for its nonlinearities. Numerical and experimental investigations are conducted on stay cables equipped with the self-sensing MR damper operated in passive and semi-active control modes. The results verify that the collocated self-sensing MR damper facilitates smart damping for inclined cables employing energy-dissipative LQG control with only force and displacement measurements at the damper. It is also demonstrated that the synthesis of nonlinear damper dynamics in the LQG control enhances damping force tracking efficiently, explores the features of the self-sensing MR damper, and achieves better control performance over the passive MR damping control and the Heaviside step function-based LQG control that ignores the damper dynamics.

Experimental study on the fire protection properties of PVC sheath for old and new cables.

PubMed

Xie, Qiyuan; Zhang, Heping; Tong, Lin

2010-07-15

The objective of the present study is to analyze the fire protection properties of old and new cables through TG, FTIR and MCC experiments. The results show that the mass loss of old cable sheath is clearly larger than the new one when the temperature is higher than 550 K in air or nitrogen atmosphere. It suggests that the old cable sheath starts to pyrolyze generally at the same temperature based on the analysis of the onset temperatures of mass loss. The results also show that there is a main peak DTG for the old and new cable sheath under each condition. However, the main peak DTG of old cable sheath is larger than that of the new cable sheath, especially in air atmosphere. The FTIR experiments show that the HCl is released by the new cable later but more quickly than the old cable. The MCC experiments suggest that compared with the new one, the peak heat release rate is larger for the old cable. It illustrates that the old cable sheath generally pyrolyzes and combusts more strongly and completely than the new one. Namely, the fire protection properties of the old cable in old buildings are relatively weak. 2010 Elsevier B.V. All rights reserved.

Static and Dynamic Characteristics of a Long-Span Cable-Stayed Bridge with CFRP Cables

PubMed Central

Xie, Xu; Li, Xiaozhang; Shen, Yonggang

2014-01-01

In this study, the scope of CFRP cables in cable-stayed bridges is studied by establishing a numerical model of a 1400-m span of the same. The mechanical properties and characteristics of CFRP stay cables and of a cable-stayed bridge with CFRP cables are here subjected to comprehensive analysis. The anomalies in the damping properties of free vibration, nonlinear parametric vibration and wind fluctuating vibration between steel cables and CFRP cables are determined. The structural stiffness, wind resistance and traffic vibration of the cable-stayed bridge with CFRP cables are also analyzed. It was found that the static performances of a cable-stayed bridge with CFRP cables and steel cables are basically the same. The natural frequencies of CFRP cables do not coincide with the major natural frequencies of the cable-stayed bridge, so the likelihood of CFRP cable-bridge coupling vibration is minuscule. For CFRP cables, the response amplitudes of both parametric vibration and wind fluctuating vibration are smaller than those of steel cables. It can be concluded from the research that the use of CFRP cables does not change the dynamic characteristics of the vehicle-bridge coupling vibration. Therefore, they can be used in long-span cable-stayed bridges with an excellent mechanical performance. PMID:28788710

Static and Dynamic Characteristics of a Long-Span Cable-Stayed Bridge with CFRP Cables.

PubMed

Xie, Xu; Li, Xiaozhang; Shen, Yonggang

2014-06-23

In this study, the scope of CFRP cables in cable-stayed bridges is studied by establishing a numerical model of a 1400-m span of the same. The mechanical properties and characteristics of CFRP stay cables and of a cable-stayed bridge with CFRP cables are here subjected to comprehensive analysis. The anomalies in the damping properties of free vibration, nonlinear parametric vibration and wind fluctuating vibration between steel cables and CFRP cables are determined. The structural stiffness, wind resistance and traffic vibration of the cable-stayed bridge with CFRP cables are also analyzed. It was found that the static performances of a cable-stayed bridge with CFRP cables and steel cables are basically the same. The natural frequencies of CFRP cables do not coincide with the major natural frequencies of the cable-stayed bridge, so the likelihood of CFRP cable-bridge coupling vibration is minuscule. For CFRP cables, the response amplitudes of both parametric vibration and wind fluctuating vibration are smaller than those of steel cables. It can be concluded from the research that the use of CFRP cables does not change the dynamic characteristics of the vehicle-bridge coupling vibration. Therefore, they can be used in long-span cable-stayed bridges with an excellent mechanical performance.

Development of material formula and structure property indicators for low cold-resistant characterization of Cables’ Material

NASA Astrophysics Data System (ADS)

Sun, W.; Cai, Y. G.; Feng, Y. M.; Li, Y. L.; Zhou, H. Y.; Zhou, Y.

2018-01-01

Alpine regions account for about 27.9% of total land area in China. Northeast China, Inner Mongolia, Northwest China and other regions are located in alpine regions, wherein the above regions are rich in energy. However, the low-temperature impact embrittlement temperature of traditional PVC cable materials is between -15°C and -20°C, which is far lower than actual operation requirements. Cable insulation and sheath are always damaged during cable laying in alpine regions. Therefore, it is urgent to develop low-temperature-resistant cables applicable to low-temperature environment in alpine regions, and safe and stable operation of power grids in the alpine regions can be guaranteed. In the paper, cold-resistant PVC formula systems were mainly trial-manufactured and studied. Appropriate production technologies and formulas were determined through selecting raw materials and modified materials. The low-temperature impact embrittlement temperature was adjusted below -50°C under the precondition that PVC cable materials met national standard property requirements. Cold-resistant PVC cable materials were prepared, which were characterized by excellent physical and mechanical properties, and sound extrusion process, and cold-resistant PVC cable materials can meet production requirements of low-temperature-resistant cables. Meanwhile, the prepared cold-resistant cable material was used for extruding finished product cables and trial-manufacturing sample cables. Type tests of low temperature elongation ratio, 15min withstand voltage, etc. were completed for 35kV and lower sample cables in Mohe Low-temperature Test Site. All properties were consistent with standard requirements.

KENNEDY SPACE CENTER, FLA. - Research team members work with acoustic cable during underwater acoustic research being conducted in the Launch Complex 39 turn basin. Several government agencies, including NASA, NOAA, the Navy, the Coast Guard, and the Florida Fish and Wildlife Commission are involved in the testing. The research involves demonstrations of passive and active sensor technologies, with applications in fields ranging from marine biological research to homeland security. The work is also serving as a pilot project to assess the cooperation between the agencies involved. Equipment under development includes a passive acoustic monitor developed by NASA’s Jet Propulsion Laboratory, and mobile robotic sensors from the Navy’s Mobile Diving and Salvage Unit.

NASA Image and Video Library

2003-08-18

KENNEDY SPACE CENTER, FLA. - Research team members work with acoustic cable during underwater acoustic research being conducted in the Launch Complex 39 turn basin. Several government agencies, including NASA, NOAA, the Navy, the Coast Guard, and the Florida Fish and Wildlife Commission are involved in the testing. The research involves demonstrations of passive and active sensor technologies, with applications in fields ranging from marine biological research to homeland security. The work is also serving as a pilot project to assess the cooperation between the agencies involved. Equipment under development includes a passive acoustic monitor developed by NASA’s Jet Propulsion Laboratory, and mobile robotic sensors from the Navy’s Mobile Diving and Salvage Unit.

Instrumentation techniques for monitoring shock and detonation waves

NASA Astrophysics Data System (ADS)

Dick, R. D.; Parrish, R. L.

1985-09-01

CORRTEX (Continuous Reflectometry for Radius Versus Time Experiments), SLIFER (Shorted Location Indication by Frequency of Electrical Resonance), and pin probes were used to monitor several conditions of blasting such as the detonation velocity of the explosive, the functioning of the stemming column confining the explosive, and rock mass motion. CORRTEX is a passive device that employs time-domain reflectometry to interrogate the two-way transit time of a coaxial cable. SLIFER is an active device that monitors the changing frequency resulting from a change in length of a coaxial cable forming an element of an oscillator circuit. Pin probes in this application consist of RG-174 coaxial cables, each with an open circuit, placed at several known locations within the material. Each cable is connected to a pulse-forming network and a voltage source. When the cables are shorted by the advancing wave, time-distance data are produced from which a velocity can be computed. Each technique, installation of the gauge, examples of the signals, and interpretation of the records are described.

Effects of stochastic sodium channels on extracellular excitation of myelinated nerve fibers.

PubMed

Mino, Hiroyuki; Grill, Warren M

2002-06-01

The effects of the stochastic gating properties of sodium channels on the extracellular excitation properties of mammalian nerve fibers was determined by computer simulation. To reduce computation time, a hybrid multicompartment cable model including five central nodes of Ranvier containing stochastic sodium channels and 16 flanking nodes containing detenninistic membrane dynamics was developed. The excitation properties of the hybrid cable model were comparable with those of a full stochastic cable model including 21 nodes of Ranvier containing stochastic sodium channels, indicating the validity of the hybrid cable model. The hybrid cable model was used to investigate whether or not the excitation properties of extracellularly activated fibers were influenced by the stochastic gating of sodium channels, including spike latencies, strength-duration (SD), current-distance (IX), and recruitment properties. The stochastic properties of the sodium channels in the hybrid cable model had the greatest impact when considering the temporal dynamics of nerve fibers, i.e., a large variability in latencies, while they did not influence the SD, IX, or recruitment properties as compared with those of the conventional deterministic cable model. These findings suggest that inclusion of stochastic nodes is not important for model-based design of stimulus waveforms for activation of motor nerve fibers. However, in cases where temporal fine structure is important, for example in sensory neural prostheses in the auditory and visual systems, the stochastic properties of the sodium channels may play a key role in the design of stimulus waveforms.

47 CFR 36.153 - Assignment of Cable and Wire Facilities (C&WF) to categories.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Assignment of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.153 Assignment of Cable and Wire Facilities (C&WF) to... cable and intrabuilding network cable. Where an entire cable or aerial wire is assignable to one...

47 CFR 36.153 - Assignment of Cable and Wire Facilities (C&WF) to categories.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Assignment of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.153 Assignment of Cable and Wire Facilities (C&WF) to... cable and intrabuilding network cable. Where an entire cable or aerial wire is assignable to one...

Advances in Spectral Electrical Impedance Tomography (EIT) for Near-Surface Geophysical Exploration

NASA Astrophysics Data System (ADS)

Huisman, J. A.; Zimmermann, E.; Kelter, M.; Zhao, Y.; Bukhary, T. H.; Vereecken, H.

2016-12-01

Recent advances in spectral Electrical Impedance Tomography (EIT) now allow to obtain the complex electrical conductivity distribution in near-surface environments with a high accuracy for a broad range of frequencies (mHz - kHz). One of the key advances has been the development of correction methods to account for inductive coupling effects between wires used for current and potential measurements and capacitive coupling between cables and the subsurface environment. In this study, we first review these novel correction methods and then illustrate how the consideration of capacitive and inductive coupling improves spectral EIT results. For this, borehole EIT measurements were made in a shallow aquifer using a custom-made EIT system with two electrode chains each consisting of eight active electrodes with a separation of 1 m. The EIT measurements were inverted with and without consideration of inductive and capacitive coupling effects. The inversion results showed that spatially and spectrally consistent imaging results can only be obtained when inductive coupling effects are considered (phase accuracy of 1-2 mrad at 1 kHz). Capacitive coupling effects were found to be of secondary importance for the set-up used here, but its importance will increase when longer cables are used. Although these results are promising, the active electrode chains can only be used with our custom-made EIT system. Therefore, we also explored to what extent EIT measurements with passive electrode chains amenable to commercially available EIT measurement systems can be corrected for coupling effects. It was found that EIT measurements with passive unshielded cables could not be corrected above 100 Hz because of the strong but inaccurately known capacitive coupling between the electrical wires. However, it was possible to correct EIT measurements with passive shielded cables, and the final accuracy of the phase measurements was estimated to be 2-4 mrad at 1 kHz.

Passive Vibration Control of Existing Structures by Gravity-Loaded Cables

NASA Astrophysics Data System (ADS)

Alvis, E.; Tsang, H. H.; Hashemi, M. J.

2017-06-01

Structures with high concentration of mass at or close to the top such as highway bridge piers are vulnerable in earthquakes or accidents. In this paper, a simple and convenient retrofit strategy is proposed for minimizing vibrations and damages, extending service life and preventing collapse of existing structures. The proposed system comprises of tension-only cables secured to the sides of the structure through gravity anchor blocks that are free to move in vertical shafts. The system is installed in such a way that the cables do not induce unnecessary stress on the main structure when there is no lateral motion or vibration. The effectiveness of controlling global structural responses is investigated for tension-only bilinear-elastic behaviour of cables. Results of a realistic case study for a reinforced concrete bridge pier show that response reduction is remarkably well under seismic excitation.

Cluster analysis of stress corrosion mechanisms for steel wires used in bridge cables through acoustic emission particle swarm optimization.

PubMed

Li, Dongsheng; Yang, Wei; Zhang, Wenyao

2017-05-01

Stress corrosion is the major failure type of bridge cable damage. The acoustic emission (AE) technique was applied to monitor the stress corrosion process of steel wires used in bridge cable structures. The damage evolution of stress corrosion in bridge cables was obtained according to the AE characteristic parameter figure. A particle swarm optimization cluster method was developed to determine the relationship between the AE signal and stress corrosion mechanisms. Results indicate that the main AE sources of stress corrosion in bridge cables included four types: passive film breakdown and detachment of the corrosion product, crack initiation, crack extension, and cable fracture. By analyzing different types of clustering data, the mean value of each damage pattern's AE characteristic parameters was determined. Different corrosion damage source AE waveforms and the peak frequency were extracted. AE particle swarm optimization cluster analysis based on principal component analysis was also proposed. This method can completely distinguish the four types of damage sources and simplifies the determination of the evolution process of corrosion damage and broken wire signals. Copyright © 2017. Published by Elsevier B.V.

Fully synthetic taped insulation cables

DOEpatents

Forsyth, E.B.; Muller, A.C.

1983-07-15

The present invention is a cable which, although constructed from inexpensive polyolefin tapes and using typical impregnating oils, furnishes high voltage capability up to 765 kV, and has such excellent dielectric characteristics and heat transfer properties that it is capable of operation at capacities equal to or higher than presently available cables at a given voltage. This is accomplished by using polyethylene, polybutene or polypropylene insulating tape which has been specially processed to attain properties which are not generally found in these materials, but are required for their use in impregnated electrical cables. Chief among these properties is compatibility with impregnating oil.

Passive fetal monitoring sensor

NASA Astrophysics Data System (ADS)

Zuckerwar, Allan J.; Hall, Earl T.; Baker, Donald A.; Bryant, Timothy D.

1992-08-01

An ambulatory, passive sensor for use in a fetal monitoring system is discussed. The invention is comprised of a piezoelectric polymer film, combined with a metallic mounting plate fastened to a belt, and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted by a fetus inside an expectant mother. Additionally, the monitor will filter out pressure pulses arising from other sources, such as the maternal heart.

Passive fetal monitoring sensor

NASA Astrophysics Data System (ADS)

1990-07-01

The invention is an ambulatory, passive sensor for use in a fetal monitoring system. The invention incorporates piezoelectric polymer film combined with a metallic mounting plate fastened to a belt and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted from a fetus inside an expectant mother and to provide means for filtering out pressure pulses arising from other sources, such as the maternal heart.

Passive fetal monitoring sensor

NASA Technical Reports Server (NTRS)

Zuckerwar, Allan J. (Inventor); Hall, Earl T. (Inventor); Baker, Donald A. (Inventor); Bryant, Timothy D. (Inventor)

1992-01-01

An ambulatory, passive sensor for use in a fetal monitoring system is discussed. The invention is comprised of a piezoelectric polymer film, combined with a metallic mounting plate fastened to a belt, and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted by a fetus inside an expectant mother. Additionally, the monitor will filter out pressure pulses arising from other sources, such as the maternal heart.

KENNEDY SPACE CENTER, FLA. - Research team members roll out acoustic cable to the water's edge during underwater acoustic research being conducted in the Launch Complex 39 turn basin. Several government agencies, including NASA, NOAA, the Navy, the Coast Guard, and the Florida Fish and Wildlife Commission are involved in the testing. The research involves demonstrations of passive and active sensor technologies, with applications in fields ranging from marine biological research to homeland security. The work is also serving as a pilot project to assess the cooperation between the agencies involved. Equipment under development includes a passive acoustic monitor developed by NASA’s Jet Propulsion Laboratory, and mobile robotic sensors from the Navy’s Mobile Diving and Salvage Unit.

NASA Image and Video Library

2003-08-18

KENNEDY SPACE CENTER, FLA. - Research team members roll out acoustic cable to the water's edge during underwater acoustic research being conducted in the Launch Complex 39 turn basin. Several government agencies, including NASA, NOAA, the Navy, the Coast Guard, and the Florida Fish and Wildlife Commission are involved in the testing. The research involves demonstrations of passive and active sensor technologies, with applications in fields ranging from marine biological research to homeland security. The work is also serving as a pilot project to assess the cooperation between the agencies involved. Equipment under development includes a passive acoustic monitor developed by NASA’s Jet Propulsion Laboratory, and mobile robotic sensors from the Navy’s Mobile Diving and Salvage Unit.

Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges

PubMed Central

Ahmad, Javaid; Ghrib, Faouzi

2015-01-01

Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control. PMID:26167539

Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges.

PubMed

Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

2015-01-01

Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control.

Cable deformation simulation and a hierarchical framework for Nb3Sn Rutherford cables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arbelaez, D.; Prestemon, S. O.; Ferracin, P.

2009-09-13

Knowledge of the three-dimensional strain state induced in the superconducting filaments due to loads on Rutherford cables is essential to analyze the performance of Nb{sub 3}Sn magnets. Due to the large range of length scales involved, we develop a hierarchical computational scheme that includes models at both the cable and strand levels. At the Rutherford cable level, where the strands are treated as a homogeneous medium, a three-dimensional computational model is developed to determine the deformed shape of the cable that can subsequently be used to determine the strain state under specified loading conditions, which may be of thermal, magnetic,more » and mechanical origins. The results can then be transferred to the model at the strand/macro-filament level for rod restack process (RRP) strands, where the geometric details of the strand are included. This hierarchical scheme can be used to estimate the three-dimensional strain state in the conductor as well as to determine the effective properties of the strands and cables from the properties of individual components. Examples of the modeling results obtained for the orthotropic mechanical properties of the Rutherford cables are presented.« less

Gbit/s-operation of graphene electro-absorption modulators in a passive polymer waveguide platform for data and telecommunications

NASA Astrophysics Data System (ADS)

Kleinert, M.; Reinke, P.; Bach, H.-G.; Brinker, W.; Zawadzki, C.; Dietrich, A.; de Felipe, D.; Keil, N.; Schell, M.

2017-02-01

Graphene with its high carrier mobility as well as its tunable light absorption is an attractive active material for highspeed electro-absorption modulators (EAMs). Large-area CVD-grown graphene monolayers can be transferred onto arbitrary substrates to add active optoelectronic properties to intrinsically passive photonic integration platforms. In this work, we present graphene-based EAMs integrated in passive polymer waveguides. To facilitate modulation frequencies in the GHz range, a 50 Ω termination resistor as well as a DC blocking capacitor are integrated with graphene EAMs for the first time. Large signal data transmission experiments were carried out across the O, C and L optical communications bands. The fastest devices exhibit a 3-dB bandwidth of more than 4 GHz. Our analytical model of the modulation response for the graphene-based EAMs is in good agreement with the measurement results. It predicts that bandwidths greater than 50 GHz are possible with future device iterations. Owing to the absorption properties of the graphene layers, the devices are expected to be functional at smaller wavelengths of interest for optical interconnects and data-communications as well, offering a novel flexibility for the integration of high-speed functionalities in optoelectronic integrated circuits. Our work is the first step towards an Active Optical Printed Circuit Board, hiding the optics completely inside the board and thus removing entry barriers in manufacturing. We believe this will lead to the same success as observed in Active Optical Cables for short range optically wired connections.

47 CFR 36.154 - Exchange Line Cable and Wire Facilities (C&WF)-Category 1-apportionment procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Exchange Line Cable and Wire Facilities (C&WF... COMPANIES 1 Telecommunications Property Cable and Wire Facilities § 36.154 Exchange Line Cable and Wire... apportioning the cost of exchange line cable and wire facilities among the operations is the determination of...

47 CFR 36.154 - Exchange Line Cable and Wire Facilities (C&WF)-Category 1-apportionment procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Exchange Line Cable and Wire Facilities (C&WF... COMPANIES 1 Telecommunications Property Cable and Wire Facilities § 36.154 Exchange Line Cable and Wire... apportioning the cost of exchange line cable and wire facilities among the operations is the determination of...

Using passive fiber-optic distributed temperature sensing to estimate soil water content at a discontinuous permafrost site

NASA Astrophysics Data System (ADS)

Wagner, A. M.; Lindsey, N.; Ajo Franklin, J. B.; Gelvin, A.; Saari, S.; Ekblaw, I.; Ulrich, C.; Dou, S.; James, S. R.; Martin, E. R.; Freifeld, B. M.; Bjella, K.; Daley, T. M.

2016-12-01

We present preliminary results from an experimental study targeting the use of passive fiber-optic distributed temperature sensing (DTS) in a variety of geometries to estimate moisture content evolution in a dynamic permafrost system. A 4 km continuous 2D array of multi-component fiber optic cable (6 SM/6 MM) was buried at the Fairbanks Permafrost Experiment Station to investigate the possibility of using fiber optic distributed sensing as an early detection system for permafrost thaw. A heating experiment using 120 60 Watt heaters was conducted in a 140 m2 area to artificially thaw the topmost section of permafrost. The soils at the site are primarily silt but some disturbed areas include backfilled gravel to depths of approximately 1.0 m. Where permafrost exists, the depth to permafrost ranges from 1.5 to approximately 5 m. The experiment was also used to spatially estimate soil water content distribution throughout the fiber optic array. The horizontal fiber optic cable was buried at depths between 10 and 20 cm. Soil temperatures were monitored with a DTS system at 25 cm increments along the length of the fiber. At five locations, soil water content time-domain reflectometer (TDR) probes were also installed at two depths, in line with the fiber optic cable and 15 to 25 cm below the cable. The moisture content along the fiber optic array was estimated using diurnal effects from the dual depth temperature measurements. In addition to the horizontally installed fiber optic cable, vertical lines of fiber optic cable were also installed inside and outside the heater plot to a depth of 10 m in small diameter (2 cm) boreholes. These arrays were installed in conjunction with thermistor strings and are used to monitor the thawing process and to cross correlate with soil temperatures at the depth of the TDR probes. Results will be presented from the initiation of the artificial thawing through subsequent freeze-up. A comparison of the DTS measured temperatures and thermistors in vertically installed PVC pipes will also be shown. Initial results from a thermal model of the artificial heating experiment and the model's correlation to the actual soil temperature measurements will also be presented. These results show the possibility of using fiber optic cable to measure moisture contents along a longer array with only limited control points.

47 CFR 36.152 - Categories of Cable and Wire Facilities (C&WF).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Categories of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.152 Categories of Cable and Wire Facilities (C&WF). (a) C... exchange cable and wire facilites among the operations are set forth in §§ 36.154 and 36.155. (b...

47 CFR 36.152 - Categories of Cable and Wire Facilities (C&WF).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Categories of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.152 Categories of Cable and Wire Facilities (C&WF). (a) C... exchange cable and wire facilites among the operations are set forth in §§ 36.154 and 36.155. (b...

Experimental characterization of shape memory alloy actuator cables

NASA Astrophysics Data System (ADS)

Biggs, Daniel B.; Shaw, John A.

2016-04-01

Wire rope (or cables) are a fundamental structural element in many engineering applications. Recently, there has been growing interest in stranding NiTi wires into cables to scale up the adaptive properties of NiTi tension elements and to make use of the desirable properties of wire rope. Exploratory experiments were performed to study the actuation behavior of two NiTi shape memory alloy cables and straight monofilament wire of the same material. The specimens were held under various dead loads ranging from 50 MPa to 400 MPa and thermally cycled 25 times from 140°C to 5°C at a rate of 12°C/min. Performance metrics of actuation stroke, residual strain, and work output were measured and compared between specimen types. The 7x7 cable exhibited similar actuation to the single straight wire, but with slightly longer stroke and marginally more shakedown, while maintaining equivalent specific work output. This leads to the conclusion that the 7x7 cable effectively scaled up the adaptive properties the straight wire. Under loads below 150 MPa, the 1x27 cable had up to double the actuation stroke and work output, but exhibited larger shakedown and poorer performance when loaded higher.

KENNEDY SPACE CENTER, FLA. - Research team members roll out acoustic cable to the water's edge as others stand by in a watercraft during underwater acoustic research being conducted in the Launch Complex 39 turn basin. Several government agencies, including NASA, NOAA, the Navy, the Coast Guard, and the Florida Fish and Wildlife Commission are involved in the testing. The research involves demonstrations of passive and active sensor technologies, with applications in fields ranging from marine biological research to homeland security. The work is also serving as a pilot project to assess the cooperation between the agencies involved. Equipment under development includes a passive acoustic monitor developed by NASA’s Jet Propulsion Laboratory, and mobile robotic sensors from the Navy’s Mobile Diving and Salvage Unit.

NASA Image and Video Library

2003-08-18

KENNEDY SPACE CENTER, FLA. - Research team members roll out acoustic cable to the water's edge as others stand by in a watercraft during underwater acoustic research being conducted in the Launch Complex 39 turn basin. Several government agencies, including NASA, NOAA, the Navy, the Coast Guard, and the Florida Fish and Wildlife Commission are involved in the testing. The research involves demonstrations of passive and active sensor technologies, with applications in fields ranging from marine biological research to homeland security. The work is also serving as a pilot project to assess the cooperation between the agencies involved. Equipment under development includes a passive acoustic monitor developed by NASA’s Jet Propulsion Laboratory, and mobile robotic sensors from the Navy’s Mobile Diving and Salvage Unit.

Rotation analysis on large complex superconducting cables based on numerical modeling and experiments

NASA Astrophysics Data System (ADS)

Qin, Jinggang; Yue, Donghua; Zhang, Xingyi; Wu, Yu; Liu, Xiaochuan; Liu, Huajun; Jin, Huan; Dai, Chao; Nijhuis, Arend; Zhou, Chao; Devred, Arnaud

2018-07-01

The conductors used in large fusion reactors, e.g. ITER, CFETR and DEMO, are made of cable-in-conduit conductor (CICC) with large diameters up to about 50 mm. The superconducting and copper strands are cabled around a central spiral and then wrapped with stainless-steel tape of 0.1 mm thickness. The cable is then inserted into a jacket under tensile force that increases with the length of insertion. Because the cables are long and with a large diameter, the insertion force could reach values of about 40 kN. The large tensile force could lead to significant rotation forces. This may lead to an increase of the twist pitch, especially for the final one. Understanding the twist pitch variation is very important; in particular, the twist pitch of a cable inside a CICC strongly affects its properties, especially for Nb3Sn conductors. In this paper, a simplified numerical model was used to analyze the cable rotation, including material properties, cabling tension as well as wrap tension. Several rotation experiments with tensile force have been performed to verify the numerical results for CFETR CSMC cables. The results show that the numerical analysis is consistent with the experiments and provides the optimal cabling conditions for large superconducting cables.

Integrated cable vibration control system using wireless sensors

NASA Astrophysics Data System (ADS)

Jeong, Seunghoo; Cho, Soojin; Sim, Sung-Han

2017-04-01

As the number of long-span bridges is increasing worldwide, maintaining their structural integrity and safety become an important issue. Because the stay cable is a critical member in most long-span bridges and vulnerable to wind-induced vibrations, vibration mitigation has been of interest both in academia and practice. While active and semi-active control schemes are known to be quite effective in vibration reduction compared to the passive control, requirements for equipment including data acquisition, control devices, and power supply prevent a widespread adoption in real-world applications. This study develops an integrated system for vibration control of stay-cables using wireless sensors implementing a semi-active control. Arduino, a low-cost single board system, is employed with a MEMS digital accelerometer and a Zigbee wireless communication module to build the wireless sensor. The magneto-rheological (MR) damper is selected as a damping device, controlled by an optimal control algorithm implemented on the Arduino sensing system. The developed integrated system is tested in a laboratory environment using a cable to demonstrate the effectiveness of the proposed system on vibration reduction. The proposed system is shown to reduce the vibration of stay-cables with low operating power effectively.

Semi Active Control of Civil Structures, Analytical and Numerical Studies

NASA Astrophysics Data System (ADS)

Kerboua, M.; Benguediab, M.; Megnounif, A.; Benrahou, K. H.; Kaoulala, F.

Structural control for civil structures was born out of a need to provide safer and more efficient designs with the reality of limited resources. The purpose of structural control is to absorb and to reflect the energy introduced by dynamic loads such as winds, waves, earthquakes, and traffic. Today, the protection of civil structures from severe dynamic loading is typically achieved by allowing the structures to be damaged. Semi-active control devices, also called "smart" control devices, assume the positive aspects of both the passive and active control devices. A semi-active control strategy is similar to the active control strategy. Only here, the control actuator does not directly apply force to the structure, but instead it is used to control the properties of a passive energy device, a controllable passive damper. Semi-active control strategies can be used in many of the same civil applications as passive and active control. One method of operating smart cable dampers is in a purely passive capacity, supplying the dampers with constant optimal voltage. The advantages to this strategy are the relative simplicity of implementing the control strategy as compared to a smart or active control strategy and that the dampers are more easily optimally tuned in- place, eliminating the need to have passive dampers with unique optimal damping coefficients. This research investigated semi-active control of civil structures for natural hazard mitigation. The research has two components, the seismic protection of buildings and the mitigation of wind-induced vibration in structures. An ideal semi-active motion equation of a composite beam that consists of a cantilever beam bonded with a PZT patch using Hamilton's principle and Galerkin's method was treated. A series R-L and a parallel R-L shunt circuits are coupled into the motion equation respectively by means of the constitutive relation of piezoelectric material and Kirchhoff's law to control the beam vibration. A numerical example of the parallel R-L piezoelectric vibration shunt control simulated with MATLAB® is presented. An analytical study of the resistor-inductor (R-L) passive piezoelectric vibration shunt control of a cantilever beam was undertaken. The modal and strain analyses were performed by varying the material properties and geometric configurations of the piezoelectric transducer in relation to the structure in order to maximize the mechanical strain produced in the piezoelectric transducer.

Radiopaque UHMWPE sublaminar cables for spinal deformity correction: Preclinical mechanical and radiopacifier leaching assessment.

PubMed

Roth, Alex K; Boon-Ceelen, Karlien; Smelt, Harold; van Rietbergen, Bert; Willems, Paul C; van Rhijn, Lodewijk W; Arts, Jacobus J

2018-02-01

Polymeric sublaminar cables have a number of advantages over metal cables in the field of spinal deformity surgery, with decreased risk of neurological injury and potential for higher correction forces as the two most predominant. However, currently available polymer cables are radiolucent, precluding postoperative radiological assessment of instrumentation stability and integrity. This study provides a preclinical assessment of a woven UHMWPE cable made with radiopaque UHMWPE fibers. Our primary goal was to determine if the addition of a radiopacifier negatively affects the mechanical properties of UHMWPE woven cables. Tensile mechanical properties were determined and compared to suitable controls. Radiopacity was evaluated and radiopacifier leaching was assessed in vitro and in vivo. Finally, in vivo bismuth organ content was quantified after a 24-week implantation period in sheep. Results show that the mechanical properties of woven UHMWPE cables were not deleteriously affected by the addition of homogenously dispersed bismuth oxide particles within each fiber. Limited amounts of bismuth oxide were released in vitro, well below the toxicological threshold. Tissue concentrations lower than generally accepted therapeutic dosages for use against gastrointestinal disorders, well below toxic levels, were discovered in vivo. These results substantiate controlled clinical introduction of these radiopaque UHMWPE cables. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 771-779, 2018. © 2017 Wiley Periodicals, Inc.

47 CFR 36.152 - Categories of Cable and Wire Facilities (C&WF).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 2 2014-10-01 2014-10-01 false Categories of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.152 Categories of Cable and Wire Facilities (C&WF). (a) C... channels, and for circuits between control terminals and radio stations providing very high frequency...

47 CFR 36.152 - Categories of Cable and Wire Facilities (C&WF).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 2 2013-10-01 2013-10-01 false Categories of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.152 Categories of Cable and Wire Facilities (C&WF). (a) C... channels, and for circuits between control terminals and radio stations providing very high frequency...

47 CFR 36.152 - Categories of Cable and Wire Facilities (C&WF).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 2 2012-10-01 2012-10-01 false Categories of Cable and Wire Facilities (C&WF... Telecommunications Property Cable and Wire Facilities § 36.152 Categories of Cable and Wire Facilities (C&WF). (a) C... channels, and for circuits between control terminals and radio stations providing very high frequency...

Who Owns What--An Initial Inquiry into Current Crossownership among Leading Companies in Cable Television.

ERIC Educational Resources Information Center

Katz, Helen

Despite longstanding interest in cable television regulation, little has been investigated concerning crossownership of cable with other media properties. A study examined the issue from economic (antitrust) and First Amendment (diversity of sources) perspectives. Data on where the cable companies' franchises were located and in what other media…

Differential polarization of cortical pyramidal neuron dendrites through weak extracellular fields

PubMed Central

Obermayer, Klaus

2018-01-01

The rise of transcranial current stimulation (tCS) techniques have sparked an increasing interest in the effects of weak extracellular electric fields on neural activity. These fields modulate ongoing neural activity through polarization of the neuronal membrane. While the somatic polarization has been investigated experimentally, the frequency-dependent polarization of the dendritic trees in the presence of alternating (AC) fields has received little attention yet. Using a biophysically detailed model with experimentally constrained active conductances, we analyze the subthreshold response of cortical pyramidal cells to weak AC fields, as induced during tCS. We observe a strong frequency resonance around 10-20 Hz in the apical dendrites sensitivity to polarize in response to electric fields but not in the basal dendrites nor the soma. To disentangle the relative roles of the cell morphology and active and passive membrane properties in this resonance, we perform a thorough analysis using simplified models, e.g. a passive pyramidal neuron model, simple passive cables and reconstructed cell model with simplified ion channels. We attribute the origin of the resonance in the apical dendrites to (i) a locally increased sensitivity due to the morphology and to (ii) the high density of h-type channels. Our systematic study provides an improved understanding of the subthreshold response of cortical cells to weak electric fields and, importantly, allows for an improved design of tCS stimuli. PMID:29727454

47 CFR 36.157 - Host/remote message Cable and Wire Facilities (C&WF)-Category 4-apportionment procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Host/remote message Cable and Wire Facilities... TELECOMMUNICATIONS COMPANIES 1 Telecommunications Property Cable and Wire Facilities § 36.157 Host/remote message Cable and Wire Facilities (C&WF)—Category 4—apportionment procedures. (a) Host/Remote Message C&WF...

47 CFR 36.157 - Host/remote message Cable and Wire Facilities (C&WF)-Category 4-apportionment procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Host/remote message Cable and Wire Facilities... TELECOMMUNICATIONS COMPANIES 1 Telecommunications Property Cable and Wire Facilities § 36.157 Host/remote message Cable and Wire Facilities (C&WF)—Category 4—apportionment procedures. (a) Host/Remote Message C&WF...

Cable-driven elastic parallel humanoid head with face tracking for Autism Spectrum Disorder interventions.

PubMed

Su, Hao; Dickstein-Fischer, Laurie; Harrington, Kevin; Fu, Qiushi; Lu, Weina; Huang, Haibo; Cole, Gregory; Fischer, Gregory S

2010-01-01

This paper presents the development of new prismatic actuation approach and its application in human-safe humanoid head design. To reduce actuator output impedance and mitigate unexpected external shock, the prismatic actuation method uses cables to drive a piston with preloaded spring. By leveraging the advantages of parallel manipulator and cable-driven mechanism, the developed neck has a parallel manipulator embodiment with two cable-driven limbs embedded with preloaded springs and one passive limb. The eye mechanism is adapted for low-cost webcam with succinct "ball-in-socket" structure. Based on human head anatomy and biomimetics, the neck has 3 degree of freedom (DOF) motion: pan, tilt and one decoupled roll while each eye has independent pan and synchronous tilt motion (3 DOF eyes). A Kalman filter based face tracking algorithm is implemented to interact with the human. This neck and eye structure is translatable to other human-safe humanoid robots. The robot's appearance reflects a non-threatening image of a penguin, which can be translated into a possible therapeutic intervention for children with Autism Spectrum Disorders.

State-of-the-art fiber optics for short distance frequency reference distribution

NASA Astrophysics Data System (ADS)

Lutes, G. F.; Primas, L. E.

1989-05-01

A number of recently developed fiber-optic components that hold the promise of unprecedented stability for passively stabilized frequency distribution links are characterized. These components include a fiber-optic transmitter, an optical isolator, and a new type of fiber-optic cable. A novel laser transmitter exhibits extremely low sensitivity to intensity and polarization changes of reflected light due to cable flexure. This virtually eliminates one of the shortcomings in previous laser transmitters. A high-isolation, low-loss optical isolator has been developed which also virtually eliminates laser sensitivity to changes in intensity and polarization of reflected light. A newly developed fiber has been tested. This fiber has a thermal coefficient of delay of less than 0.5 parts per million per deg C, nearly 20 times lower than the best coaxial hardline cable and 10 times lower than any previous fiber-optic cable. These components are highly suitable for distribution systems with short extent, such as within a Deep Space Communications Complex. Here, these new components are described and the test results presented.

State-of-the-art fiber optics for short distance frequency reference distribution

NASA Technical Reports Server (NTRS)

Lutes, G. F.; Primas, L. E.

1989-01-01

A number of recently developed fiber-optic components that hold the promise of unprecedented stability for passively stabilized frequency distribution links are characterized. These components include a fiber-optic transmitter, an optical isolator, and a new type of fiber-optic cable. A novel laser transmitter exhibits extremely low sensitivity to intensity and polarization changes of reflected light due to cable flexure. This virtually eliminates one of the shortcomings in previous laser transmitters. A high-isolation, low-loss optical isolator has been developed which also virtually eliminates laser sensitivity to changes in intensity and polarization of reflected light. A newly developed fiber has been tested. This fiber has a thermal coefficient of delay of less than 0.5 parts per million per deg C, nearly 20 times lower than the best coaxial hardline cable and 10 times lower than any previous fiber-optic cable. These components are highly suitable for distribution systems with short extent, such as within a Deep Space Communications Complex. Here, these new components are described and the test results presented.

Two different electrical properties can improve transoceanic cable-route mapping

USGS Publications Warehouse

Wynn, J.; McGinnis, T.

2001-01-01

Induced polarization (IP) measurements made in the marine environment were investigated to map and remotely characterize the top 6-10 meters of the seafloor. The continuous resistivity profiling with cone-penetrometer tests, providing important information to engineers planning transoceanic cable routes, was also described. The IP effect and resistivity were identified as the two electric properties to improve transoceanic cable-route mapping. The measurement of IP and resistivity was found to depend on electrical current.

Cable Effects Study. Tangents, Rabbit Holes, Dead Ends, and Valuable Results

DOE PAGES

Ardelean, Emil V.; Babuška, Vít; Goodding, James C.; ...

2014-08-04

Lessons learned during a study on the effects that electrical power and signal wiring harness cables introduce on the dynamic response of precision spacecraft is presented, along with the most significant results. Our study was a three year effort to discover a set of practical approaches for updating well-defined dynamic models of harness-free structures where knowledge of the cable type, position, and tie-down method are known. Although cables are found on every satellite, the focus was on precision, low damping, and very flexible structures. Obstacles encountered, classified as tangents, rabbit holes, and dead ends, offer practical lessons for structural dynamicsmore » research. The paper traces the historical, experiential progression of the project, describing how the obstacles affected the project. Methods were developed to estimate cable properties. Problems were encountered because of the flexible, highly damped nature of cables. A beam was used as a test article to validate experimentally derived cable properties and to refine the assumptions regarding boundary conditions. Furthermore, a spacecraft bus-like panel with cables attached was designed, and finite element models were developed and validated through experiment. Various paths were investigated at each stage before a consistent test and analysis methodology was developed« less

Fatigue properties of superelastic Ti-Ni filaments and braided cables for bone fixation.

PubMed

Baril, Y; Brailovski, V

2010-02-01

This work is focused on the fatigue properties of the braided hollow tubular cables for bone fixation made of superelastic Ti-Ni filaments. To evaluate the fatigue life of the cable and the impact of braiding on fatigue life, a comparative study was conducted on both the braided cable and the single filament. The results of strain-controlled fatigue testing under variable mean and alternating strain conditions demonstrated that: (a) even though alternating strain is the most influent parameter, mean strain also has a significant impact on the fatigue life of both the filament and the braid; an improvement in the braided cable's fatigue life is observed under mean strains corresponding to the middle of the superelastic loop plateau; and (b) run-out (10(5) cycles) is reached at 1% of alternating strain for the filament, and at 0.3% for the braided cable. It was proved that the negative impact of braiding on fatigue life is caused: (a) by friction-induced damage of the braided filaments during cable manufacturing and (b) by locally occurring bending in the vicinity of the filaments' crossing, combined with the interfilament fretting during repetitive stretching of the braided cable.

Cable Effects Study. Tangents, Rabbit Holes, Dead Ends, and Valuable Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ardelean, Emil V.; Babuška, Vít; Goodding, James C.

Lessons learned during a study on the effects that electrical power and signal wiring harness cables introduce on the dynamic response of precision spacecraft is presented, along with the most significant results. Our study was a three year effort to discover a set of practical approaches for updating well-defined dynamic models of harness-free structures where knowledge of the cable type, position, and tie-down method are known. Although cables are found on every satellite, the focus was on precision, low damping, and very flexible structures. Obstacles encountered, classified as tangents, rabbit holes, and dead ends, offer practical lessons for structural dynamicsmore » research. The paper traces the historical, experiential progression of the project, describing how the obstacles affected the project. Methods were developed to estimate cable properties. Problems were encountered because of the flexible, highly damped nature of cables. A beam was used as a test article to validate experimentally derived cable properties and to refine the assumptions regarding boundary conditions. Furthermore, a spacecraft bus-like panel with cables attached was designed, and finite element models were developed and validated through experiment. Various paths were investigated at each stage before a consistent test and analysis methodology was developed« less

Rapid cable tension estimation using dynamic and mechanical properties

NASA Astrophysics Data System (ADS)

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

2016-04-01

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

A novel method for surface defect inspection of optic cable with short-wave infrared illuminance

NASA Astrophysics Data System (ADS)

Chen, Xiaohong; Liu, Ning; You, Bo; Xiao, Bin

2016-07-01

Intelligent on-line detection of cable quality is a crucial issue in optic cable factory, and defects on the surface of optic cable can dramatically depress cable grade. Manual inspection in optic cable quality cannot catch up with the development of optic cable industry due to its low detection efficiency and huge human cost. Therefore, real-time is highly demanded by industry in order to replace the subjective and repetitive process of manual inspection. For this reason, automatic cable defect inspection has been a trend. In this paper, a novel method for surface defect inspection of optic cable with short-wave infrared illuminance is presented. The special condition of short-wave infrared cannot only provide illumination compensation for the weak illumination environment, but also can avoid the problem of exposure when using visible light illuminance, which affects the accuracy of inspection algorithm. A series of image processing algorithms are set up to analyze cable image for the verification of real-time and veracity of the detection method. Unlike some existing detection algorithms which concentrate on the characteristics of defects with an active search way, the proposed method removes the non-defective areas of the image passively at the same time of image processing, which reduces a large amount of computation. OTSU algorithm is used to convert the gray image to the binary image. Furthermore, a threshold window is designed to eliminate the fake defects, and the threshold represents the considered minimum size of defects ε . Besides, a new regional suppression method is proposed to deal with the edge burrs of the cable, which shows the superior performance compared with that of Open-Close operation of mathematical morphological in the boundary processing. Experimental results of 10,000 samples show that the rates of miss detection and false detection are 2.35% and 0.78% respectively when ε equals to 0.5 mm, and the average processing period of one frame image is 2.39 ms. All the improvements have been verified in the paper to show the ability of our inspection method for optic cable.

Electric poling and electromechanical characterization of 0.1-mm-thick sensor films and 0.2-mm-thick cable layers from piezoelectric poly(vinylidene fluoride-trifluoroethylene).

PubMed

Wegener, Michael; Gerhard-Multhaupt, Reimund

2003-07-01

Piezoelectric polymers have been proposed for many sensor and actuator applications. Among these, piezoelectric polymer films with thicknesses between several tens and a few hundreds of micrometers as well as coaxial cables with piezoelectric polymer layers are highly suitable and attractive for the detection of mechanical loads. In addition to good piezoelectric properties, materials for such sensors should have high mechanical strength. Therefore, the most common materials are nonporous piezoelectric polymers, such as polyvinylidene fluoride (PVDF) or its copolymer with trifluoroethylene (P(VDF-TrFE)). Here, P(VDF-TrFE) polymer films as well as the operating principle and the geometry of piezoelectric polymer cables are described. As active piezoelectric cable layer, P(VDF-TrFE) (76/24) was employed. After electrical poling with one or more point-to-cable corona discharges, the polarization in the P(VDF-TrFE) layer was investigated. Poling parameters, such as electric field and poling time, were varied. The resulting polarization was characterized with measurements of polarization profiles across the film or the cable-layer thickness as well as with the determination of other electromechanical quantities. The optimized poling process yields good piezoelectric properties in the piezoelectric polymer layers as well as useful sensor properties of the piezoelectric polymer cable, which are assessed and discussed.

Estimation of macroscopic elastic characteristics for hierarchical anisotropic solids based on probabilistic approach

NASA Astrophysics Data System (ADS)

Smolina, Irina Yu.

2015-10-01

Mechanical properties of a cable are of great importance in design and strength calculation of flexible cables. The problem of determination of elastic properties and rigidity characteristics of a cable modeled by anisotropic helical elastic rod is considered. These characteristics are calculated indirectly by means of the parameters received from statistical processing of experimental data. These parameters are considered as random quantities. With taking into account probable nature of these parameters the formulas for estimation of the macroscopic elastic moduli of a cable are obtained. The calculating expressions for macroscopic flexural rigidity, shear rigidity and torsion rigidity using the macroscopic elastic characteristics obtained before are presented. Statistical estimations of the rigidity characteristics of some cable grades are adduced. A comparison with those characteristics received on the basis of deterministic approach is given.

Armstrong Flight Research Center Flight Test Capabilities and Opportunities for the Applications of Wireless Data Acquisition Systems

NASA Technical Reports Server (NTRS)

Hang, Richard

2015-01-01

The presentation will overview NASA Armstrong Flight Research Centers flight test capabilities, which can provide various means for flight testing of passive and active wireless sensor systems, also, it will address the needs of the wireless data acquisition solutions for the centers flight instrumentation issues such as additional weight caused by added instrumentation wire bundles, connectors, wire cables routing, moving components, etc., that the Passive Wireless Sensor Technology Workshop may help. The presentation shows the constraints and requirements that the wireless sensor systems will face in the flight test applications.

Notes on recent approaches concerning the Kirchhoff-law-Johnson-noise-based secure key exchange

NASA Astrophysics Data System (ADS)

Kish, Laszlo B.; Horvath, Tamas

2009-08-01

We critically analyze the results and claims in [P.-L. Liu, Phys. Lett. A 373 (2009) 901]. We show that the strong security leak appeared in the simulations is only an artifact and not caused by “multiple reflections”. Since no wave modes exist at cable length of 5% of the shortest wavelength of the signal, no wave is present to reflect it. In the high wave impedance limit, the conditions used in the simulations are heavily unphysical (requiring cable diameters up to 28000 times greater than the measured size of the known universe) and the results are modeling artifacts due to the unphysical values. At the low cable impedance limit, the observed artifacts are due to violating the recommended (and tested) conditions by neglecting the cable capacitance restrictions and using about 100 times longer cable than recommended without cable capacitance compensation arrangement. We implement and analyze the general circuitry of Liu's circulator [P.-L. Liu, Phys. Lett. A 373 (2009) 901] and confirm that they are conceptually secure against passive attacks. We introduce an asymmetric, more robust version without feedback loop. Then we crack all these systems by an active attack: a circulator-based man-in-the middle attack. Finally, we analyze the proposed method to increase security by dropping only high-risk bits. We point out the differences between different types of high-risk bits and show the shortage of this strategy for some simple key exchange protocols.

Application of Optical Diagnosis to Aged Low-Voltage Cable Insulation in Nuclear Plants

NASA Astrophysics Data System (ADS)

Katagiri, Junichi; Takezawa, Yoshitaka; Shouji, Hiroshi

We have developed a novel non-destructive optical diagnosis technique for low-voltage cable insulations used in nuclear power plants. The key features of this diagnosis are the use of two wavelengths to measure the change in reflective absorbance (ΔAR), the use of polarized light to measure crystallinity and the use of element volatilizing to measure fluorescence. Chemical kinetics is used to predict the lifetimes of the cable insulations. When cable insulations darken and harden by time degradation, the ΔAR and depolarization parameters increase. This means that the cross-linking density in the cable insulations increases due to deterioration reactions. When the cross-linking density of insulation increases, its elasticity, corresponding to the material's life, increases. Similarly, as the crystallinity increases due to the change in the high-order structure of the insulating resin caused by irradiation, its elongation property decreases. The elongation property of insulation is one of the most important parameters that can be used to evaluate material lifetimes, because it relates to elasticity. The ΔAR correlated with the elongation property, and the correlation coefficient of an accelerated experiment using model pieces was over 0.9. Thus, we concluded that this optical diagnosis should be applied to evaluate the degradation of cable insulations used in nuclear power plants.

Fixation systems of greater trochanteric osteotomies: biomechanical and clinical outcomes.

PubMed

Jarit, Gregg J; Sathappan, Sathappan S; Panchal, Anand; Strauss, Eric; Di Cesare, Paul E

2007-10-01

The development of cerclage systems for fixation of greater trochanteric osteotomies has progressed from monofilament wires to multifilament cables to cable grip and cable plate systems. Cerclage wires and cables have various clinical indications, including fixation for fractures and for trochanteric osteotomy in hip arthroplasty. To achieve stable fixation and eventual union of the trochanteric osteotomy, the implant must counteract the destabilizing forces associated with pull of the peritrochanteric musculature. The material properties of cables and cable grip systems are superior to those of monofilament wires; however, potential complications with the use of cables include debris generation and third-body polyethylene wear. Nevertheless, the cable grip system provides the strongest fixation and results in lower rates of nonunion and trochanteric migration. Cable plate constructs show promise but require further clinical studies to validate their efficacy and safety.

Radiation Testing of a Low Voltage Silicone Nuclear Power Plant Cable.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernstein, Robert

This report summarizes the results generated in FY13 for cable insulation in support of DOE's Light Water Reactor Sustainability (LWRS) Program, in collaboration with the US- Argentine Binational Energy Working Group (BEWG). A silicone (SiR) cable, which was stored in benign conditions for %7E30 years, was obtained from Comision Nacional de Energia Atomica (CNEA) in Argentina. Physical property testing was performed on the as-received cable. This cable was artificially aged to assess behavior with additional analysis. SNL observed appreciable tensile elongation values for all cable insulations received, indicative of good mechanical performance. Of particular note, the work presented here providesmore » correlations between measured tensile elongation and other physical properties that may be potentially leveraged as a form of condition monitoring (CM) for actual service cables. It is recognized at this point that the polymer aging community is still lacking the number and types of field returned materials that are desired, but SNL -- along with the help of others -- is continuing to work towards that goal. This work is an initial study that should be complimented with location- mapping of environmental conditions of CNEA plant conditions (dose and temperature) as well as retrieval, analysis, and comparison with in-service cables.« less

Coaxial printing method for directly writing stretchable cable as strain sensor

NASA Astrophysics Data System (ADS)

Yan, Hai-liang; Chen, Yan-qiu; Deng, Yong-qiang; Zhang, Li-long; Hong, Xiao; Lau, Woon-ming; Mei, Jun; Hui, David; Yan, Hui; Liu, Yu

2016-08-01

Through applying the liquid metal and elastomer as the core and shell materials, respectively, a coaxial printing method is being developed in this work for preparing a stretchable and conductive cable. When liquid metal alloy eutectic Gallium-Indium is embedded into the elastomer matrix under optimized control, the cable demonstrates well-posed extreme mechanic performance, under stretching for more than 350%. Under developed compression test, the fabricated cable also demonstrates the ability for recovering original properties due to the high flowability of the liquid metal and super elasticity of the elastomeric shell. The written cable presents high cycling reliability regarding its stretchability and conductivity, two properties which can be clearly predicted in theoretical calculation. This work can be further investigated as a strain sensor for monitoring motion status including frequency and amplitude of a curved object, with extensive applications in wearable devices, soft robots, electronic skins, and wireless communication.

Coaxial printing method for directly writing stretchable cable as strain sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Hai-liang; Chengdu Green Energy and Green Manufacturing Technology R&D Center, 610299 Chengdu; Chen, Yan-qiu, E-mail: yu.liu@vip.163.com, E-mail: cyqleaf@qq.com, E-mail: hyan@but.ac.cn

Through applying the liquid metal and elastomer as the core and shell materials, respectively, a coaxial printing method is being developed in this work for preparing a stretchable and conductive cable. When liquid metal alloy eutectic Gallium-Indium is embedded into the elastomer matrix under optimized control, the cable demonstrates well–posed extreme mechanic performance, under stretching for more than 350%. Under developed compression test, the fabricated cable also demonstrates the ability for recovering original properties due to the high flowability of the liquid metal and super elasticity of the elastomeric shell. The written cable presents high cycling reliability regarding its stretchabilitymore » and conductivity, two properties which can be clearly predicted in theoretical calculation. This work can be further investigated as a strain sensor for monitoring motion status including frequency and amplitude of a curved object, with extensive applications in wearable devices, soft robots, electronic skins, and wireless communication.« less

Comprehensive Morpho-Electrotonic Analysis Shows 2 Distinct Classes of L2 and L3 Pyramidal Neurons in Human Temporal Cortex

PubMed Central

Deitcher, Yair; Eyal, Guy; Kanari, Lida; Verhoog, Matthijs B; Atenekeng Kahou, Guy Antoine; Mansvelder, Huibert D; de Kock, Christiaan P J; Segev, Idan

2017-01-01

Abstract There have been few quantitative characterizations of the morphological, biophysical, and cable properties of neurons in the human neocortex. We employed feature-based statistical methods on a rare data set of 60 3D reconstructed pyramidal neurons from L2 and L3 in the human temporal cortex (HL2/L3 PCs) removed after brain surgery. Of these cells, 25 neurons were also characterized physiologically. Thirty-two morphological features were analyzed (e.g., dendritic surface area, 36 333 ± 18 157 μm2; number of basal trees, 5.55 ± 1.47; dendritic diameter, 0.76 ± 0.28 μm). Eighteen features showed a significant gradual increase with depth from the pia (e.g., dendritic length and soma radius). The other features showed weak or no correlation with depth (e.g., dendritic diameter). The basal dendritic terminals in HL2/L3 PCs are particularly elongated, enabling multiple nonlinear processing units in these dendrites. Unlike the morphological features, the active biophysical features (e.g., spike shapes and rates) and passive/cable features (e.g., somatic input resistance, 47.68 ± 15.26 MΩ, membrane time constant, 12.03 ± 1.79 ms, average dendritic cable length, 0.99 ± 0.24) were depth-independent. A novel descriptor for apical dendritic topology yielded 2 distinct classes, termed hereby as “slim-tufted” and “profuse-tufted” HL2/L3 PCs; the latter class tends to fire at higher rates. Thus, our morpho-electrotonic analysis shows 2 distinct classes of HL2/L3 PCs. PMID:28968789

Static and dynamic parasitic magnetizations and their control in superconducting accelerator dipoles

NASA Astrophysics Data System (ADS)

Collings, E. W.; Sumption, M. D.

2001-05-01

Long dipole magnets guide the particle beams in synchrotron-type high energy accelerators. In principal Cu-wound DC-excited dipoles could be designed to deliver a very uniform transverse bore field, i.e. with small or negligible harmonic (multipolar) distortion. But if the Cu is replaced by (a) superconducting strand that is (b) wound into a Rutherford cable carrying a time-varying transport current, extra magnetizations present within the windings cause distortions of the otherwise uniform field. The static (persistent-current) strand magnetization can be reduced by reducing the filament diameter, and the residue compensated or corrected by strategically placed active or passive components. The cable’s interstrand coupling currents can be controlled by increasing the interstrand contact resistance by: adjusting the level of native oxidation of the strand, coating it, or by inserting a ribbon-like core into the cable itself. Methods of locally compensating the magnetization of NbTi and Nb 3Sn strand and cable are discussed, progress in coupling-current suppression through the use of coatings and cores is reviewed, and a method of simultaneously reducing both the static and dynamic magnetizations of a NbTi cable by means of a thin Ni core is suggested.

Electrical aging markers for EPR-based low-voltage cable insulation wiring of nuclear power plants

NASA Astrophysics Data System (ADS)

Verardi, L.; Fabiani, D.; Montanari, G. C.

2014-01-01

This paper presents results of electrical property measurements on EPR-based insulations of low-voltage power cables used in nuclear power plants. The specimens underwent accelerated aging through the simultaneous application of high temperature and gamma-radiation. Mechanical properties and the dielectric response at different frequencies were investigated. Results showed significant variation of the electrical and mechanical properties of aged cables at low frequencies, i.e. lower than 10-2 Hz. In particular, the real and imaginary parts of permittivity increase with aging time, accumulated dose and stress levels applied showing good correlation with elongation at break, which decreases as a function of extent of insulation aging.

Applications of FRP-OFBG sensors on bridge cables

NASA Astrophysics Data System (ADS)

Zhou, Zhi; Zhang, Zhichun; Deng, Nianchun; Zhao, Xuefeng; Li, Dongsheng; Wang, Chuang; Ou, Jinping

2005-05-01

It is still a practical problem how to effectively install FBG sensors on bridge cabes. In this paper, a simple and effective solution is introduced to develop smart bridge cables using FRP-OFBG bars developed in HIT (Harbin Institute of Technology). Here, the FRP-OFBG bar acts as one component of the cable and shows force resistance and well-protected sensors in service. The installation techniques and the sensing properties of FBGs in three kinds of cables, FRP cables, common steel-wire cable and extruded-anchor cable, are introduced and tested under dead load. Moreover, the preliminary introduction of a practical field application based on this solution has been also given. The experimental results show that the deformability of FRP-OFBG bars in the smart cables can reach the terminal and show wonderful accuracy, which shows that such kind of smart cable is practical in field application.

Combustibility of Electrical Wire and Cable for Rail Rapid Transit Systems. Volume 1. Flammability.

DOT National Transportation Integrated Search

1983-05-01

The objective of this study was to examine the flammability of wires and cables used in rapid rail transit systems. The overall goal of the study was to quantify the fire properties of wires and cables in a manner so that the relative fire hazards co...

Combustibility of Electrical Wire and Cable for Rail Rapid Transit Systems. Volume 2. Toxicity.

DOT National Transportation Integrated Search

1983-05-01

The objective of this study was to examine the flammability of wires and cables used in rapid rail transit systems. The overall goal of the study was to quantify the fire properties of wires and cables in a manner so that the relative fire hazards co...

Simultaneous Thermal and Gamma Radiation Aging of Electrical Cable Polymers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fifield, Leonard S.

The polymers used for insulation in nuclear power plant electrical cables are susceptible to aging during long term operation. Elevated temperature is the primary contributor to changes in polymer structure that result loss of mechanical and electrical properties, but gamma radiation is also a significant source of degradation for polymers used within relevant plant locations. Despite many years of polymer degradation research, the combined effects of simultaneous exposure to thermal and radiation stress are not well understood. As nuclear operators contemplate and prepare for extended operations beyond initial license periods, a predictive understanding of exposure-based cable material degradation is becomingmore » an increasingly important input to safety, licensing, operations and economic decisions. We are focusing on carefully-controlled simultaneous thermal and gamma radiation accelerating aging and characterization of the most common nuclear cable polymers to understand the relative contributions of temperature, time, dose and dose rate to changes in cable polymer material structure and properties. Improved understanding of cable performance in long term operation will help support continued sustainable nuclear power generation.« less

Material Selection for Cable Gland to Improved Reliability of the High-hazard Industries

NASA Astrophysics Data System (ADS)

Vashchuk, S. P.; Slobodyan, S. M.; Deeva, V. S.; Vashchuk, D. S.

2018-01-01

The sealed cable glands (SCG) are available to ensure safest connection sheathed single wire for the hazard production facility (nuclear power plant and others) the same as pilot cable, control cables, radio-frequency cables et al. In this paper, we investigate the specifics of the material selection of SCG with the express aim of hazardous man-made facility. We discuss the safe working conditions for cable glands. The research indicates the sintering powdered metals cables provide the reliability growth due to their properties. A number of studies have demonstrated the verification of material selection. On the face of it, we make findings indicating that double glazed sealed units could enhance reliability. We had evaluated sample reliability under fire conditions, seismic load, and pressure containment failure. We used the samples mineral insulated thermocouple cable.

Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants – Interim Study FY13

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simmons, Kevin L.; Fifield, Leonard S.; Westman, Matthew P.

2013-09-27

The most important criterion for cable performance is its ability to withstand a design-basis accident. With nearly 1000 km of power, control, instrumentation, and other cables typically found in an NPP, it would be a significant undertaking to inspect all of the cables. Degradation of the cable jacket, electrical insulation, and other cable components is a key issue that is likely to affect the ability of the currently installed cables to operate safely and reliably for another 20 to 40 years beyond the initial operating life. The development of one or more nondestructive evaluation (NDE) techniques and supporting models thatmore » could assist in determining the remaining life expectancy of cables or their current degradation state would be of significant interest. The ability to nondestructively determine material and electrical properties of cable jackets and insulation without disturbing the cables or connections has been deemed essential. Currently, the only technique accepted by industry to measure cable elasticity (the gold standard for determining cable insulation degradation) is the indentation measurement. All other NDE techniques are used to find flaws in the cable and do not provide information to determine the current health or life expectancy. There is no single NDE technique that can satisfy all of the requirements needed for making a life-expectancy determination, but a wide range of methods have been evaluated for use in NPPs as part of a continuous evaluation program. The commonly used methods are indentation and visual inspection, but these are only suitable for easily accessible cables. Several NDE methodologies using electrical techniques are in use today for flaw detection but there are none that can predict the life of a cable. There are, however, several physical and chemical ptoperty changes in cable insulation as a result of thermal and radiation damage. In principle, these properties may be targets for advanced NDE methods to provide early warning of aging and degradation. Examples of such key indicators include changes in chemical structure, mechanical modulus, and dielectric permittivity. While some of these indicators are the basis of currently used technologies, there is a need to increase the volume of cable that may be inspected with a single measurement, and if possible, to develop techniques for in-situ inspection (i.e., while the cable is in operation). This is the focus of the present report.« less

Literature review of environmental qualification of safety-related electric cables: Summary of past work. Volume 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subudhi, M.

1996-04-01

This report summarizes the findings from a review of published documents dealing with research on the environmental qualification of safety-related electric cables used in nuclear power plants. Simulations of accelerated aging and accident conditions are important considerations in qualifying the cables. Significant research in these two areas has been performed in the US and abroad. The results from studies in France, Germany, and Japan are described in this report. In recent years, the development of methods to monitor the condition of cables has received special attention. Tests involving chemical and physical examination of cable`s insulation and jacket materials, and electricalmore » measurements of the insulation properties of cables are discussed. Although there have been significant advances in many areas, there is no single method which can provide the necessary information about the condition of a cable currently in service. However, it is possible that further research may identify a combination of several methods that can adequately characterize the cable`s condition.« less

Analytical and numerical construction of equivalent cables.

PubMed

Lindsay, K A; Rosenberg, J R; Tucker, G

2003-08-01

The mathematical complexity experienced when applying cable theory to arbitrarily branched dendrites has lead to the development of a simple representation of any branched dendrite called the equivalent cable. The equivalent cable is an unbranched model of a dendrite and a one-to-one mapping of potentials and currents on the branched model to those on the unbranched model, and vice versa. The piecewise uniform cable, with a symmetrised tri-diagonal system matrix, is shown to represent the canonical form for an equivalent cable. Through a novel application of the Laplace transform it is demonstrated that an arbitrary branched model of a dendrite can be transformed to the canonical form of an equivalent cable. The characteristic properties of the equivalent cable are extracted from the matrix for the transformed branched model. The one-to-one mapping follows automatically from the construction of the equivalent cable. The equivalent cable is used to provide a new procedure for characterising the location of synaptic contacts on spinal interneurons.

Radiation Testing of a Low Voltage Silicone Nuclear Power Plant Cable.

DOE Office of Scientific and Technical Information (OSTI.GOV)

White II, Gregory Von; Schroeder, John Lee.; Sawyer, Patricia Sue.

This report summarizes the results generated in FY13 for cable insulation in support of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program, in collaboration with the US-Argentine Binational Energy Working Group (BEWG). A silicone (SiR) cable, which was stored in benign conditions for %7E30 years, was obtained from Comision Nacional de Energia Atomica (CNEA) in Argentina with the approval of NA-SA (Nucleoelectrica Argentina Sociedad Anonima). Physical property testing was performed on the as-received cable. This cable was artificially aged to assess behavior with additional analysis. SNL observed appreciable tensile elongation values for all cable insulations received, indicative ofmore » good mechanical performance. Of particular note, the work presented here provides correlations between measured tensile elongation and other physical properties that may be potentially leveraged as a form of condition monitoring (CM) for actual service cables. It is recognized at this point that the polymer aging community is still lacking the number and types of field returned materials that are desired, but Sandia National Laboratories (SNL) -- along with the help of others -- is continuing to work towards that goal. This work is an initial study that should be complimented with location-mapping of environmental conditions of Argentinean plant conditions (dose and temperature) as well as retrieval, analysis, and comparison with in- service cables.« less

Detection and characterization of corrosion of bridge cables by time domain reflectometry

NASA Astrophysics Data System (ADS)

Liu, Wei; Hunsperger, Robert G.; Folliard, Kevin; Chajes, Michael J.; Barot, Jignesh; Jhaveri, Darshan; Kunz, Eric

1999-02-01

In this paper, we develop and demonstrate a nondestructive evaluation technique for corrosion detection of embedded or encased steel cables. This technique utilizes time domain reflectometry (TDR), which has been traditionally used to detect electrical discontinuities in transmission lines. By applying a sensor wire along with the bridge cable, we can model the cable as an asymmetric, twin-conductor transmission line. Physical defects of the bridge cable will change the electromagnetic properties of the line and can be detected by TDR. Furthermore, different types of defects can be modeled analytically, and identified using TDR. TDR measurement results from several fabricated bridge cable sections with built-in defects are reported.

Investigation of the strength of shielded and unshielded underwater electrical cables

NASA Astrophysics Data System (ADS)

Glowe, D. E.; Arnett, S. L.

1981-09-01

The mechanical properties of shielded and unshielded submarine cables (MIL-C-915/8E) were investigated to determine the effect of shielding on cable life, performance, and reliability. Ten cables (five shielded and five unshielded) were selected for laboratory evaluation. A mission profile was developed to establish the mechanical stress limits that cables must endure in service and a test sequence designed to measure tensile strength, flexural abrasion endurance, crush resistance, creep under static tension, and performance in a hull-stuffing tube. The results of this program showed that: (1) DSS-2 cable does not have adequate tensile strength and should have a strength member added. DSS-3 and larger cables have adequate tensile strength with or without the shield; (2) Unshielded DSS-3 type cable does not perform satisfactorily in hull-stuffing tubes; (3) Shielding is not required to meet mission profile specifications for cable crush or flexural abrasion resistance; (4) Construction parameters other than shielding can significantly affect mechanical performance of cable; (5) Unshielded cable construction can result in increased reliability since it permits a thicker single-jacket construction; and (6) Unshielded cable construction can reduce the cost of cable by 8 to 20 percent.

Development of a single-phase 30 m HTS power cable

NASA Astrophysics Data System (ADS)

Cho, Jeonwook; Bae, Joon-Han; Kim, Hae-Jong; Sim, Ki-Deok; Kim, Seokho; Jang, Hyun-Man; Lee, Chang-Young; Kim, Dong-Wook

2006-05-01

HTS power transmission cables appear to be the replacement and retrofitting of underground cables in urban areas and HTS power transmission cable offers a number of technical and economic merits compared to the normal conductor cable system. A 30 m long, single-phase 22.9 kV class HTS power transmission cable system has been developed by Korea Electrotechnology Research Institute (KERI), LS Cable Ltd., and Korea Institute of Machinery and Materials (KIMM), which is one of the 21st century frontier project in Korea since 2001. The HTS power cable has been developed, cooled down and tested to obtain realistic thermal and electrical data on HTS power cable system. The evaluation results clarified such good performance of HTS cable that DC critical current of the HTS cable was 3.6 kA and AC loss was 0.98 W/m at 1260 Arms and shield current was 1000 Arms. These results proved the basic properties for 22.9 kV HTS power cable. As a next step, we have been developing a 30 m, three-phase 22.9 kV, 50 MV A HTS power cable system and long term evaluation is in progress now.

Elasticity and Mechanical Advantage in Cables and Ropes

ERIC Educational Resources Information Center

O'Shea, M. J.

2007-01-01

Abstract. The conditions under which one can gain mechanical advantage by pulling with a force F perpendicular to a cable (or rope) that is fixed at both ends are examined. While this is a commonly discussed example in introductory physics classes, its solution in terms of fundamental properties of the cable requires one to model the elasticity of…

Scaled position-force tracking for wireless teleoperation of miniaturized surgical robotic system.

PubMed

Guo, Jing; Liu, Chao; Poignet, Philippe

2014-01-01

Miniaturized surgical robotic system presents promising trend for reducing invasiveness during operation. However, cables used for power and communication may affect its performance. In this paper we chose Zigbee wireless communication as a means to replace communication cables for miniaturized surgical robot. Nevertheless, time delay caused by wireless communication presents a new challenge to performance and stability of the teleoperation system. We proposed a bilateral wireless teleoperation architecture taking into consideration of the effect of position-force scaling between operator and slave. Optimal position-force tracking performance is obtained and the overall system is shown to be passive with a simple condition on the scaling factors satisfied. Simulation studies verify the efficiency of the proposed scaled wireless teleoperation scheme.

Self-healing cable for extreme environments

NASA Technical Reports Server (NTRS)

Huston, Dryver R. (Inventor); Tolmie, Bernard R. (Inventor)

2009-01-01

Self-healing cable apparatus and methods disclosed. The self-healing cable has a central core surrounded by an adaptive cover that can extend over the entire length of the self-healing cable or just one or more portions of the self-healing cable. The adaptive cover includes an axially and/or radially compressible-expandable (C/E) foam layer that maintains its properties over a wide range of environmental conditions. A tape layer surrounds the C/E layer and is applied so that it surrounds and axially and/or radially compresses the C/E layer. When the self-healing cable is subjected to a damaging force that causes a breach in the outer jacket and the tape layer, the corresponding localized axially and/or radially compressed portion of the C/E foam layer expands into the breach to form a corresponding localized self-healed region. The self-healing cable is manufacturable with present-day commercial self-healing cable manufacturing tools.

Woven ribbon cable for cryogenic instruments

NASA Astrophysics Data System (ADS)

Cunningham, C. R.; Hastings, P. R.; Strachan, J. M. D.

Robust woven ribbon cables are described for connecting sensors at low temperatures to higher temperature systems. Woven cables have several advantages over conventional wiring or flat ribbon cables in cryostats: heat sinking is easier; twisted pairs may be used; and miniature multi-way connectors are easily incorporated. Their use is demonstrated in making connections from 131 bolometers in two arrays mounted in a dilution refrigerator at 100 mK. Thermal and electrical properties are discussed, as are other possible applications in cryogenic instruments.

Passively operated spool valve for drain-down freeze protection of thermosyphon water heaters. Final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1982-04-30

The work done to extend the existing drain-down valve technology to provide passive drain-down freeze protection for thermosyphon-based solar water heaters is described. The basic design of the existing valve model is that of a spool valve, employing a cylindrical spool which moves axially in a mating cartridge to open and close o-rings at the two operating extremes (drain and operate) to perform the valving function. Three passive actuators to drive the basic valving mechanism were designed, fabricated, and tested. Two piping configurations used to integrate the spool valve with the thermosyphon system are described, as are the passive actuators.more » The three actuator designs are: photovoltaic driven, refrigerant-based bellows, and heat motor cable-drive designs. Costs are compared for the alternative actuator designs, and operating characteristics were examined for the thermosyphon system, including field tests. The market for the valve for thermosyphon systems is then assessed. (LEW)« less

JPRS Report: Telecommunications.

DTIC Science & Technology

1988-03-31

Services, Integrated Business Systems , Computasia, Unitel, Cable Television and Telco Properties. 07310 Cable TV License Bidder Eyes Intermediate...international network: ARPA CNUCE (CNR) Pisa EAN IASI (CNR) Roma EARN CNUCE (CNR) Pisa SPAN INFN (CNR) Bologna UCCP Systems & Management (Private company ...largest interna- tional telecommunications companies , in a joint venture with PTAT Systems Incorporated of the U.S. The cable will form a key link in

Irradiation ageing of CSPE/EPR control command electric cables. Correlation between mechanical properties and oxidation

NASA Astrophysics Data System (ADS)

Calmet, J. F.; Carlin, F.; Nguyen, T. M.; Bousquet, S.; Quinot, P.

2002-03-01

In this paper, correlations between the elongation at break and the oxidation of chlorosulfonated polyethylene and ethylene propylene rubber (EPR) polymers in instrumentation and control cables irradiated at different dose rates are brought to evidence. During irradiation, the following phenomena are observed: an increase of oxygen consumption, a degradation of the mechanical properties and a reduction of the oxidation induction time (OIT) measured for EPR. A correlation between the mechanical properties and the OIT of the EPR has only been established in the case of irradiation at low dose rate. This reveals a difference in the oxidative degradation process at low and high dose rates. This study shows the possibility to assess the ageing of electric cables installed inside nuclear power plants by OIT measurements.

Well logging evaporative thermal protection system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamers, M.D.; Martelli, V.P.

1981-02-03

An evaporative thermal protection system for use in hostile environment well logging applications, the system including a downhole thermal protection cartridge disposed within a well logging sonde or tool to keep a payload such as sensors and support electronics cool, the cartridge carrying either an active evaporative system for refrigeration or a passive evaporative system, both exhausting to the surface through an armored flexible fluidic communication mechanical cable.

Shields for protecting cables from the effects of electromagnetic noise and interference

NASA Astrophysics Data System (ADS)

Hoeft, L. O.; Hofstra, J. S.; Karaskiewicz, R. J.; Torres, B. W.

1988-12-01

The intrinsic electromagnetic property of a cable or connector shield is its surface transfer impedance. This is the ratio of the longitudinal open circuit voltage measured on one side of the shield (normally the inside) to the axial current on the other side (normally the outside). In cases where a high electric field is present at the surface of the shield, the transfer admittance or charge transfer elastance is also important. Measurements of typical cables, connectors, backshells and cable terminations are presented and explained in terms of simple models.

Nb 3Sn RRP® strand and Rutherford cable development for a 15 T dipole demonstrator

DOE PAGES

Barzi, E.; Andreev, N.; Li, P.; ...

2016-03-16

Keystoned Rutherford cables made of 28 strands and with a stainless steel core were developed and manufactured using 1 mm Nb3Sn composite wires produced by Oxford Superconducting Technology with 127 and 169 restacks using the Restacked-Rod-Process ®. Furthermore, the performance and properties of these cables were studied to evaluate possible candidates for 15 T accelerator magnets.

Shape Memory Actuator System

DTIC Science & Technology

1998-07-31

The advantage in utilizing 15 shape-memory cables made of Nitinol for size reduction of the remote control actuator system is 1 Fi well suited for...a submarine environment because of its non-magnetic and corrosion resistance 17 properties. Use of thermoelastic Nitinol introduces other...problems because of the cooling and 18 resetting properties of Nitinol cables. It is therefore an important object of the present invention 19 on to

Thin semi-rigid coaxial cables for cryogenics applications

NASA Astrophysics Data System (ADS)

Kushino, Akihiro; Kasai, Soichi

2013-03-01

We have developed cryogenic coaxial cables for low temperature signal readout from sensitive devices, such as transition edge sensors, superconducting tunnel junctions, and kinetic inductance detectors. In order to reduce heat penetration into cryogenic stages, low thermal conductivity metals were chosen for both center and outer electrical conductors. Various types of coaxial cables, employing stainless-steel, cupro-nickel, brass, beryllium-copper, phosphor-bronze, niobium, and niobium-titanium, were manufactured using drawing dies. Thermal and electrical properties were investigated between 1 and 8 K. Coaxial cables made of copper alloys showed thermal conductance roughly consistent with literature, meanwhile Nb coaxial cable must be affected by the drawing process and thermal conductance was lowered. Attenuation of superconducting Nb and NbTi coaxial cables were observed to be adequately small up to above 10 GHz compared to those of normal conducting coaxial cables, which are subject to the Wiedemann-Franz law. We also measured normal conducting coaxial cables with silver-plated center conductors to improve high frequency performance.

Damping properties of fiber reinforced composite suitable for stayed cable

NASA Astrophysics Data System (ADS)

Li, Jianzhi; Sun, Baochen; Du, Yanliang

2011-11-01

Carbon fiber reinforced plastics (CFRP) cables were initially most investigated to replace steel cables. To further explore the advantages of FRP cables, the potential ability of vibration control is studied in this paper emphasizing the designable characteristic of hybrid FRP cables. Fiber reinforced vinyl ester composites and fiber reinforced epoxy composites were prepared by the pultrusion method. Due to the extensive application of fiber reinforced composites, the temperature spectrum and frequency spectrum of loss factor for the composite were tested using dynamic mechanical analysis (DMA) equipment. The damping properties and damping mechanism of the composite were investigated and discussed at different temperatures and frequencies. The result indicates that the loss factor of the composites is increasing with the increase of the frequency from 0.1Hz to 2 Hz and decreasing with the decrease of the temperature from -20°C to 60°C. The loss factor of the carbon fiber composite is higher than that of the glass fiber for the same matrix. The loss factor of the vinyl ester composite is higher than that of the epoxy composite for the same fiber.

Damping properties of fiber reinforced composite suitable for stayed cable

NASA Astrophysics Data System (ADS)

Li, Jianzhi; Sun, Baochen; Du, Yanliang

2012-04-01

Carbon fiber reinforced plastics (CFRP) cables were initially most investigated to replace steel cables. To further explore the advantages of FRP cables, the potential ability of vibration control is studied in this paper emphasizing the designable characteristic of hybrid FRP cables. Fiber reinforced vinyl ester composites and fiber reinforced epoxy composites were prepared by the pultrusion method. Due to the extensive application of fiber reinforced composites, the temperature spectrum and frequency spectrum of loss factor for the composite were tested using dynamic mechanical analysis (DMA) equipment. The damping properties and damping mechanism of the composite were investigated and discussed at different temperatures and frequencies. The result indicates that the loss factor of the composites is increasing with the increase of the frequency from 0.1Hz to 2 Hz and decreasing with the decrease of the temperature from -20°C to 60°C. The loss factor of the carbon fiber composite is higher than that of the glass fiber for the same matrix. The loss factor of the vinyl ester composite is higher than that of the epoxy composite for the same fiber.

Mechanical and Chemical Properties of Harvested Hypalon Cable Jacket Subjected to Accelerated Thermal Aging

DOE PAGES

Duckworth, Robert C.; Kidder, Michelle K.; Aytug, Tolga; ...

2018-02-27

We report that for nuclear power plants (NPPs) considering second license renewal for operation beyond 60 years, knowledge of long-term operation, condition monitoring, and viability for the reactor components including reactor pressure vessel, concrete structures, and cable systems is essential. Such knowledge will provide NPP owners/operators with a basis for predicting performance and estimating the costs associated with monitoring or replacement programs for the affected systems. For cable systems that encompass a wide variety of materials, manufacturers, and in-plant locations, accelerated aging of harvested cable jacket and insulation can provide insight into a remaining useful life and methods for monitoring.more » Accelerated thermal aging in air at temperatures between 80°C and 120°C was conducted on a multiconductor control rod drive mechanism cable manufactured by Boston Insulated Wire (BIW). The cable, which had been in service for over 30 years, was jacketed with Hypalon and insulated with ethylene propylene rubber. From elongation at break (EAB) measurements and supporting Arrhenius analysis of the jacket material, an activation energy of 97.84 kJ/mol was estimated, and the time to degradation, as represented by 50% EAB at the expected maximum operating temperature of 45°C, was estimated to be 80 years. These values were slightly below previous measurements on similar BIW Hypalon cable jacket and could be attributed to either in-service degradation or variations in material properties from production variations. Lastly, results from indenter modulus measurements and Fourier transform infrared spectroscopy suggest possible markers that could be beneficial in monitoring cable conditions.« less

Mechanical and Chemical Properties of Harvested Hypalon Cable Jacket Subjected to Accelerated Thermal Aging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duckworth, Robert C.; Kidder, Michelle K.; Aytug, Tolga

We report that for nuclear power plants (NPPs) considering second license renewal for operation beyond 60 years, knowledge of long-term operation, condition monitoring, and viability for the reactor components including reactor pressure vessel, concrete structures, and cable systems is essential. Such knowledge will provide NPP owners/operators with a basis for predicting performance and estimating the costs associated with monitoring or replacement programs for the affected systems. For cable systems that encompass a wide variety of materials, manufacturers, and in-plant locations, accelerated aging of harvested cable jacket and insulation can provide insight into a remaining useful life and methods for monitoring.more » Accelerated thermal aging in air at temperatures between 80°C and 120°C was conducted on a multiconductor control rod drive mechanism cable manufactured by Boston Insulated Wire (BIW). The cable, which had been in service for over 30 years, was jacketed with Hypalon and insulated with ethylene propylene rubber. From elongation at break (EAB) measurements and supporting Arrhenius analysis of the jacket material, an activation energy of 97.84 kJ/mol was estimated, and the time to degradation, as represented by 50% EAB at the expected maximum operating temperature of 45°C, was estimated to be 80 years. These values were slightly below previous measurements on similar BIW Hypalon cable jacket and could be attributed to either in-service degradation or variations in material properties from production variations. Lastly, results from indenter modulus measurements and Fourier transform infrared spectroscopy suggest possible markers that could be beneficial in monitoring cable conditions.« less

A Wireless Fully Passive Neural Recording Device for Unobtrusive Neuropotential Monitoring.

PubMed

Kiourti, Asimina; Lee, Cedric W L; Chae, Junseok; Volakis, John L

2016-01-01

We propose a novel wireless fully passive neural recording device for unobtrusive neuropotential monitoring. Previous work demonstrated the feasibility of monitoring emulated brain signals in a wireless fully passive manner. In this paper, we propose a novel realistic recorder that is significantly smaller and much more sensitive. The proposed recorder utilizes a highly efficient microwave backscattering method and operates without any formal power supply or regulating elements. Also, no intracranial wires or cables are required. In-vitro testing is performed inside a four-layer head phantom (skin, bone, gray matter, and white matter). Compared to our former implementation, the neural recorder proposed in this study has the following improved features: 1) 59% smaller footprint, 2) up to 20-dB improvement in neuropotential detection sensitivity, and 3) encapsulation in biocompatible polymer. For the first time, temporal emulated neuropotentials as low as 63 μVpp can be detected in a wireless fully passive manner. Remarkably, the high-sensitivity achieved in this study implies reading of most neural signals generated by the human brain. The proposed recorder brings forward transformational possibilities in wireless fully passive neural detection for a very wide range of applications (e.g., epilepsy, Alzheimer's, mental disorders, etc.).

Inductively coupled wireless RF coil arrays.

PubMed

Bulumulla, S B; Fiveland, E; Park, K J; Foo, T K; Hardy, C J

2015-04-01

As the number of coils increases in multi-channel MRI receiver-coil arrays, RF cables and connectors become increasingly bulky and heavy, degrading patient comfort and slowing workflow. Inductive coupling of signals provides an attractive "wireless" approach, with the potential to reduce coil weight and cost while simplifying patient setup. In this work, multi-channel inductively coupled anterior arrays were developed and characterized for 1.5T imaging. These comprised MR receiver coils inductively (or "wirelessly") linked to secondary or "sniffer" coils whose outputs were transmitted via preamps to the MR system cabinet. The induced currents in the imaging coils were blocked by passive diode circuits during RF transmit. The imaging arrays were totally passive, obviating the need to deliver power to the coils, and providing lightweight, untethered signal reception with easily positioned coils. Single-shot fast spin echo images were acquired from 5 volunteers using a 7-element inductively coupled coil array and a conventionally cabled 7-element coil array of identical geometry, with the inductively-coupled array showing a relative signal-to-noise ratio of 0.86 +/- 0.07. The concept was extended to a larger 9-element coil array to demonstrate the effect of coil element size on signal transfer and RF-transmit blocking. Copyright © 2015 Elsevier Inc. All rights reserved.

Dynamic properties of stay cables on the Penobscot Narrows bridge.

DOT National Transportation Integrated Search

2014-09-01

Cable-stayed bridges have been recognized as the most efficient and cost effective structural form for medium to long : span bridges over the past several decades. With their widespread use, cases of serviceability problems associated with : large am...

47 CFR 36.151 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... AND RESERVES FOR TELECOMMUNICATIONS COMPANIES 1 Telecommunications Property Cable and Wire Facilities § 36.151 General. (a) Cable and Wire Facilities, Account 2410, includes the following types of... cost of the facilities so identified. Because of variations among companies in the character of the...

H-Man: a planar, H-shape cabled differential robotic manipulandum for experiments on human motor control.

PubMed

Campolo, Domenico; Tommasino, Paolo; Gamage, Kumudu; Klein, Julius; Hughes, Charmayne M L; Masia, Lorenzo

2014-09-30

In the last decades more robotic manipulanda have been employed to investigate the effect of haptic environments on motor learning and rehabilitation. However, implementing complex haptic renderings can be challenging from technological and control perspectives. We propose a novel robot (H-Man) characterized by a mechanical design based on cabled differential transmission providing advantages over current robotic technology. The H-Man transmission translates to extremely simplified kinematics and homogenous dynamic properties, offering the possibility to generate haptic channels by passively blocking the mechanics, and eliminating stability concerns. We report results of experiments characterizing the performance of the device (haptic bandwidth, Z-width, and perceived impedance). We also present the results of a study investigating the influence of haptic channel compliance on motor learning in healthy individuals, which highlights the effects of channel compliance in enhancing proprioceptive information. The generation of haptic channels to study motor redundancy is not easy for actual robots because of the needs of powerful actuation and complex real-time control implementation. The mechanical design of H-Man affords the possibility to promptly create haptic channels by mechanical stoppers (on one of the motors) without compromising the superior backdriveability and high isotropic manipulability. This paper presents a novel robotic device for motor control studies and robotic rehabilitation. The hardware was designed with specific emphasis on the mechanics that result in a system that is easy to control, homogeneous, and is intrinsically safe for use. Copyright © 2014 Elsevier B.V. All rights reserved.

Ruby-based inorganic scintillation detectors for 192Ir brachytherapy

NASA Astrophysics Data System (ADS)

Kertzscher, Gustavo; Beddar, Sam

2016-11-01

We tested the potential of ruby inorganic scintillation detectors (ISDs) for use in brachytherapy and investigated various unwanted luminescence properties that may compromise their accuracy. The ISDs were composed of a ruby crystal coupled to a poly(methyl methacrylate) fiber-optic cable and a charge-coupled device camera. The ISD also included a long-pass filter that was sandwiched between the ruby crystal and the fiber-optic cable. The long-pass filter prevented the Cerenkov and fluorescence background light (stem signal) induced in the fiber-optic cable from striking the ruby crystal, which generates unwanted photoluminescence rather than the desired radioluminescence. The relative contributions of the radioluminescence signal and the stem signal were quantified by exposing the ruby detectors to a high-dose-rate brachytherapy source. The photoluminescence signal was quantified by irradiating the fiber-optic cable with the detector volume shielded. Other experiments addressed time-dependent luminescence properties and compared the ISDs to commonly used organic scintillator detectors (BCF-12, BCF-60). When the brachytherapy source dwelled 0.5 cm away from the fiber-optic cable, the unwanted photoluminescence was reduced from  >5% to  <1% of the total signal as long as the ISD incorporated the long-pass filter. The stem signal was suppressed with a band-pass filter and was  <3% as long as the source distance from the scintillator was  <7 cm. Some ruby crystals exhibited time-dependent luminescence properties that altered the ruby signal by  >5% within 10 s from the onset of irradiation and after the source had retracted. The ruby-based ISDs generated signals of up to 20 times that of BCF-12-based detectors. The study presents solutions to unwanted luminescence properties of ruby-based ISDs for high-dose-rate brachytherapy. An optic filter should be sandwiched between the ruby crystal and the fiber-optic cable to suppress the photoluminescence. Furthermore, we recommend avoiding ruby crystals that exhibit significant time-dependent luminescence.

Ruby-based inorganic scintillation detectors for 192Ir brachytherapy

PubMed Central

Kertzscher, Gustavo; Beddar, Sam

2016-01-01

We tested the potential of ruby inorganic scintillation detectors (ISDs) for use in brachytherapy and investigated various unwanted luminescence properties that may compromise their accuracy. The ISDs were composed of a ruby crystal coupled to a poly(methyl methacrylate) fiber-optic cable and a charge-coupled device camera. The ISD also included a long-pass filter that was sandwiched between the ruby crystal and the fiber-optic cable. The long-pass filter prevented the Cerenkov and fluorescence background light (stem signal) induced in the fiber-optic cable from striking the ruby crystal, which generates unwanted photoluminescence rather than the desired radioluminescence. The relative contributions of the radioluminescence signal and the stem signal were quantified by exposing the ruby detectors to a high-dose-rate brachytherapy source. The photoluminescence signal was quantified by irradiating the fiber-optic cable with the detector volume shielded. Other experiments addressed time-dependent luminescence properties and compared the ISDs to commonly used organic scintillator detectors (BCF-12, BCF-60). When the brachytherapy source dwelled 0.5 cm away from the fiber-optic cable, the unwanted photoluminescence was reduced from > 5% to < 1% of the total signal as long as the ISD incorporated the long-pass filter. The stem signal was suppressed with a band-pass filter and was < 3% as long as the source distance from the scintillator was < 7 cm. Some ruby crystals exhibited time-dependent luminescence properties that altered the ruby signal by > 5% within 10 s from the onset of irradiation and after the source had retracted. The ruby-based ISDs generated signals of up to 20 times that of BCF-12-based detectors. The study presents solutions to unwanted luminescence properties of ruby-based ISDs for high-dose-rate brachytherapy. An optic filter should be sandwiched between the ruby crystal and the fiber-optic cable to suppress the photoluminescence. Furthermore, we recommend avoiding ruby crystals that exhibit significant time-dependent luminescence. PMID:27740947

Ruby-based inorganic scintillation detectors for 192Ir brachytherapy.

PubMed

Kertzscher, Gustavo; Beddar, Sam

2016-11-07

We tested the potential of ruby inorganic scintillation detectors (ISDs) for use in brachytherapy and investigated various unwanted luminescence properties that may compromise their accuracy. The ISDs were composed of a ruby crystal coupled to a poly(methyl methacrylate) fiber-optic cable and a charge-coupled device camera. The ISD also included a long-pass filter that was sandwiched between the ruby crystal and the fiber-optic cable. The long-pass filter prevented the Cerenkov and fluorescence background light (stem signal) induced in the fiber-optic cable from striking the ruby crystal, which generates unwanted photoluminescence rather than the desired radioluminescence. The relative contributions of the radioluminescence signal and the stem signal were quantified by exposing the ruby detectors to a high-dose-rate brachytherapy source. The photoluminescence signal was quantified by irradiating the fiber-optic cable with the detector volume shielded. Other experiments addressed time-dependent luminescence properties and compared the ISDs to commonly used organic scintillator detectors (BCF-12, BCF-60). When the brachytherapy source dwelled 0.5 cm away from the fiber-optic cable, the unwanted photoluminescence was reduced from  >5% to  <1% of the total signal as long as the ISD incorporated the long-pass filter. The stem signal was suppressed with a band-pass filter and was  <3% as long as the source distance from the scintillator was  <7 cm. Some ruby crystals exhibited time-dependent luminescence properties that altered the ruby signal by  >5% within 10 s from the onset of irradiation and after the source had retracted. The ruby-based ISDs generated signals of up to 20 times that of BCF-12-based detectors. The study presents solutions to unwanted luminescence properties of ruby-based ISDs for high-dose-rate brachytherapy. An optic filter should be sandwiched between the ruby crystal and the fiber-optic cable to suppress the photoluminescence. Furthermore, we recommend avoiding ruby crystals that exhibit significant time-dependent luminescence.

Assessment of the insulation degradation of cables used in nuclear power plants

NASA Astrophysics Data System (ADS)

Bartoníc̆ek, B.; Hnát, V.; Plac̆ek, V.

1999-05-01

Cable insulating materials are usually, during their operational lifetime, exposed to a high number of various deteriorative enviromental effects resulting in their degradation. In the case of cables used in the nuclear power plant (NPP) hermetic zone these factors consist predominantly of long-term irradiation (at rather low dose rates, in the presence of oxygen) and enhanced temperature. Hence, all cables assigned for use in NPP have to be qualified for use under such severe conditions. However, not only the initial qualification but also monitoring of the actual state of the installed cables in regular intervals is now recommended. Monitoring of the actual state of the cable insulation and the prediction of their residual service life (i.e., the on-going qualification) consist of the measurement of the properties that are directly proportional to the functionality of the cables (usually the elongation at break is used as the critical parameter). For the cables installed in the NPP hermetic zone a method based on the measurement of the thermo-oxidative stability by the differential scanning calorimetry has been developed.

Iodine doped carbon nanotube cables exceeding specific electrical conductivity of metals

PubMed Central

Zhao, Yao; Wei, Jinquan; Vajtai, Robert; Ajayan, Pulickel M.; Barrera, Enrique V.

2011-01-01

Creating highly electrically conducting cables from macroscopic aggregates of carbon nanotubes, to replace metallic wires, is still a dream. Here we report the fabrication of iodine-doped, double-walled nanotube cables having electrical resistivity reaching ∼10−7 Ω.m. Due to the low density, their specific conductivity (conductivity/weight) is higher than copper and aluminum and is only just below that of the highest specific conductivity metal, sodium. The cables exhibit high current-carrying capacity of 104∼105 A/cm2 and can be joined together into arbitrary length and diameter, without degradation of their electrical properties. The application of such nanotube cables is demonstrated by partly replacing metal wires in a household light bulb circuit. The conductivity variation as a function of temperature for the cables is five times smaller than that for copper. The high conductivity nanotube cables could find a range of applications, from low dimensional interconnects to transmission lines. PMID:22355602

47 CFR 32.2341 - Large private branch exchanges.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 32.2341 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES..., Intrabuilding Network Cable. (c) The cost of outside plant, whether or not on private property, used with intrabuilding, network cable shall be charged to the appropriate outside plant accounts. (d)-(e) [Reserved] (f...

Treeing phenomenon of thermoplastic polyethylene blends for recyclable cable insulation materials

NASA Astrophysics Data System (ADS)

Li, Lunzhi; Zhang, Kai; Zhong, Lisheng; Gao, Jinghui; Xu, Man; Chen, Guanghui; Fu, Mingli

2017-02-01

Owing to its good recyclability and low processing energy consumption, non-crosslinked polyethylene blends (e.g. LLDPE-HDPE blends) are considered as one of potential environmental-friendly substitutions for crosslinked polyethylene (XLPE) as cable insulation material. Although extensive work has been performed for measuring the basic dielectric properties, there is a lack of the investigations on the aging properties for such a material system, which hinders the evaluation of reliability and lifetime of the material for cable insulation. In this paper, we study the electric aging phenomenon of 0.7LLDPE-0.3HDPE blending material by investigating the treeing behavior, and its comparison with XLPE and LLDPE. Treeing tests show that the 0.7LLDPE-0.3HDPE blends have lower probability for treeing as well as smaller treeing dimensions. Further thermal analysis and microstructure study results suggest that the blends exhibit larger proportion of thick lamellae and higher crystallinity with homogeneously-distributed amorphous region, which is responsible for good anti-treeing performance. Our finding provides the evidence that the 0.7LLDPE-0.3HDPE blends exhibits better electric-aging-retardance properties than XLPE, which may result in a potential application for cable insulation.

An Event-Structural Account of Passive Acquisition in Korean

ERIC Educational Resources Information Center

Lee, Kwee-Ock; Lee, Youngjoo

2008-01-01

Some peculiar properties of children's passives have long been observed in various languages such as an asymmetry between actional passives and nonactional passives. These peculiarities have been accounted for under the hypothesis that children's early passives are adjectival, and as such exhibit properties of adjectival passives in adult grammar.…

Catenary-induced geometric nonlinearity effects on cable linear vibrations

NASA Astrophysics Data System (ADS)

Mansour, Achref; Mekki, Othman Ben; Montassar, Sami; Rega, Giuseppe

2018-01-01

This paper investigates the free undamped vibrations of cables of arbitrary sag and inclination according to the catenary theory. The proposed approach accounts for the catenary effect on the static profile around which the cable motion is defined. Considering first order geometric nonlinearities, exact expression of the curvature is obtained along with the ensuing correction of the well known Irvine parameter. Taking into account the new characterization, different regions of shallow and non-shallow profiles are identified for various inclinations. In view of such classification, the analysis carried out on cable linear modal properties shows the emergence of new dynamic features such as additional hybrid modes and internal resonances. Analytical and numerical results reduce to those obtained by classic formulations in the cases of both horizontal and inclined shallow/non-shallow cables.

Lightning vulnerability of fiber-optic cables.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, Leonard E.; Caldwell, Michele

2008-06-01

One reason to use optical fibers to transmit data is for isolation from unintended electrical energy. Using fiber optics in an application where the fiber cable/system penetrates the aperture of a grounded enclosure serves two purposes: first, it allows for control signals to be transmitted where they are required, and second, the insulating properties of the fiber system help to electrically isolate the fiber terminations on the inside of the grounded enclosure. A fundamental question is whether fiber optic cables can allow electrical energy to pass through a grounded enclosure, with a lightning strike representing an extreme but very importantmore » case. A DC test bed capable of producing voltages up to 200 kV was used to characterize electrical properties of a variety of fiber optic cable samples. Leakage current in the samples were measured with a micro-Ammeter. In addition to the leakage current measurements, samples were also tested to DC voltage breakdown. After the fiber optic cables samples were tested with DC methods, they were tested under representative lightning conditions at the Sandia Lightning Simulator (SLS). Simulated lightning currents of 30 kA and 200 kA were selected for this test series. This paper documents measurement methods and test results for DC high voltage and simulated lightning tests performed at the Sandia Lightning Simulator on fiber optic cables. The tests performed at the SLS evaluated whether electrical energy can be conducted inside or along the surface of a fiber optic cable into a grounded enclosure under representative lightning conditions.« less

7 CFR 1755.860 - RUS specification for filled buried wires.

Code of Federal Regulations, 2012 CFR

2012-01-01

... sufficient heat barrier to prevent visible evidence of conductor insulation deformation or adhesion between... Insulations and Jackets for Telecommunications Wire and Cable; ASTM D 4566-90, Standard Test Methods for Electrical Performance Properties of Insulations and Jackets for Telecommunications Wire and Cable; ASTM D...

7 CFR 1755.860 - RUS specification for filled buried wires.

Code of Federal Regulations, 2014 CFR

2014-01-01

... sufficient heat barrier to prevent visible evidence of conductor insulation deformation or adhesion between... Insulations and Jackets for Telecommunications Wire and Cable; ASTM D 4566-90, Standard Test Methods for Electrical Performance Properties of Insulations and Jackets for Telecommunications Wire and Cable; ASTM D...

7 CFR 1755.860 - RUS specification for filled buried wires.

Code of Federal Regulations, 2013 CFR

2013-01-01

... sufficient heat barrier to prevent visible evidence of conductor insulation deformation or adhesion between... Insulations and Jackets for Telecommunications Wire and Cable; ASTM D 4566-90, Standard Test Methods for Electrical Performance Properties of Insulations and Jackets for Telecommunications Wire and Cable; ASTM D...

Extracellular matrix dynamics during vertebrate axis formation.

PubMed

Czirók, András; Rongish, Brenda J; Little, Charles D

2004-04-01

The first evidence for the dynamics of in vivo extracellular matrix (ECM) pattern formation during embryogenesis is presented below. Fibrillin 2 filaments were tracked for 12 h throughout the avian intraembryonic mesoderm using automated light microscopy and algorithms of our design. The data show that these ECM filaments have a reproducible morphogenic destiny that is characterized by directed transport. Fibrillin 2 particles initially deposited in the segmental plate mesoderm are translocated along an unexpected trajectory where they eventually polymerize into an intricate scaffold of cables parallel to the anterior-posterior axis. The cables coalesce near the midline before the appearance of the next-formed somite. Moreover, the ECM filaments define global tissue movements with high precision because the filaments act as passive motion tracers. Quantification of individual and collective filament "behaviors" establish fate maps, trajectories, and velocities. These data reveal a caudally propagating traveling wave pattern in the morphogenetic movements of early axis formation. We conjecture that within vertebrate embryos, long-range mechanical tension fields are coupled to both large-scale patterning and local organization of the ECM. Thus, physical forces or stress fields are essential requirements for executing an emergent developmental pattern-in this case, paraxial fibrillin cable assembly.

Qualification Testing of Solid Rocket Booster Diagonal Strut Restraint Cable Assembly Part Number 10176-0031-102/103

NASA Technical Reports Server (NTRS)

Malone, T. W.

2006-01-01

This Technical Memorandum presents qualification test results for solid rocket booster diagonal strut restraint cable part number 101276-00313-102/103. During flight this assembly is exposed to a range of temperatures. MIL-W-83420 shows the breaking strength of the cable as 798 kg (1,760 lb) at room temperature but does not define cable strength at the maximum temperature to which the cable is exposed during the first 2 min of flight; 669 C (1,236 F). The cable, which can be built from different corrosion resistant steel alloys, may also vary in its chemical, physical, and mechanical properties at temperature. Negative margins of safety were produced by analysis of the cable at temperature using standard knockdown factors. However, MSFC-HDBK-5 allows the use of a less conservative safety factor of 1.4 and knockdown factors verified by testing. Test results allowed a calculated knockdown factor of 0.1892 to be determined for the restraint cables, which provides a minimum breaking strength of 151 kg (333 lb) at 677 C (1,250 F) when combined with the minimum breaking strength of 0.317-cm (0.125- or 1/8-in) diameter, type 1 composition rope.

Inductive passive sensor for intraparenchymal and intraventricular monitoring of intracranial pressure.

PubMed

Behfar, Mohammad H; Abada, Emily; Sydanheimo, Lauri; Goldman, Ken; Fleischman, Aaron J; Gupta, Nalin; Ukkonen, Leena; Roy, Shuvo

2016-08-01

Accurate measurement of intracranial hypertension is crucial for the management of elevated intracranial pressure (ICP). Catheter-based intraventricular ICP measurement is regarded as the gold standard for accurate ICP monitoring. However, this method is invasive, time-limited, and associated with complications. In this paper, we propose an implantable passive sensor that could be used for continuous intraparenchymal and intraventricular ICP monitoring. Moreover, the sensor can be placed simultaneously along with a cerebrospinal fluid shunt system in order to monitor its function. The sensor consists of a flexible coil which is connected to a miniature pressure sensor via an 8-cm long, ultra-thin coaxial cable. An external orthogonal-coil RF probe communicates with the sensor to detect pressure variation. The performance of the sensor was evaluated in an in vitro model for intraparenchymal and intraventricular ICP monitoring. The findings from this study demonstrate proof-of-concept of intraparenchymal and intraventricular ICP measurement using inductive passive pressure sensors.

Thermal Conductance and High-Frequency Properties of Cryogenic Normal or Superconducting Semi-rigid Coaxial Cables in the Temperature Range of 1-8 K

NASA Astrophysics Data System (ADS)

Kushino, A.; Kasai, S.; Ukibe, M.; Ohkubo, M.

2018-04-01

In this study, the characteristics of thin semi-rigid cables composed of different conductors and with outer diameters ranging from 0.86 to 1.19 mm were investigated at low temperatures. The thermal conductance was measured between approximately 1 and 8 K, and the frequency dependence of the attenuation in the cables was obtained at 3 K. The electrical conductors used in the cables were alloys: beryllium copper, brass, stainless steel (SUS304), phosphor bronze, cupronickel (CuNi), and niobium-titanium (NbTi). The thermal conductance of a commercial miniature coaxial cable with braided wires forming the outer electrical conductor was also examined for reference. The measured thermal conductance was compared to published data and that generated from material libraries and databases. Among the measured cables using normal metals, the semi-rigid cable composed of SUS304 conductors and a polytetrafluoroethylene insulator showed the lowest thermal conductance. The transmission performance of the semi-rigid cables using SUS304 or CuNi was improved by plating the central conductors with a silver coating of approximately 3 μm thickness, and their thermal conductance with the plating increased by approximately one order of magnitude. The superconducting NbTi semi-rigid cable exhibited the lowest thermal conductance of all the cables considered in the present study along with very small attenuation up to above 5 GHz.

Testing of a 1.25-m HTS Cable Made from YBCO Tapes

NASA Astrophysics Data System (ADS)

Gouge, M. J.; Lue, J. W.; Demko, J. A.; Duckworth, R. C.; Fisher, P. W.; Daumling, M.; Lindsay, D. T.; Roden, M. L.; Tolbert, J. C.

2004-06-01

Ultera and Oak Ridge National Laboratory (ORNL) have jointly designed, built, and tested a 1.25-m-long, prototype high-temperature superconducting (HTS) power cable made from 1-cm-wide, second-generation YBa2Cu3Ox (YBCO)-coated conductor tapes. Electrical tests of this cable were performed in boiling liquid nitrogen at 77 K. DC testing of the 1.25-m cable included determination of the V-I curve, with a critical current of 4200 A. This was consistent with the properties of the 24 individual YBCO tapes. AC testing of the cable was conducted at currents up to 2500 Arms. The ac losses were measured calorimetrically by measuring the response of a calibrated temperature sensor placed on the former and electrically by use of a Rogowski coil with a lock-in amplifier. AC losses of about 2 W/m were measured at a cable ac current of 2000 Arms. Overcurrent testing was conducted at peak current values up to 12 kA for pulse lengths of 0.1-0.2 s. The cable temperature increased to 105 K for a 12 kA, 0.2 s overcurrent pulse, and the cable showed no degradation after the sequence of overcurrent testing. This commercial-grade HTS cable demonstrated the feasibility of second-generation YBCO tapes in an ac cable application.

Infrared glass fiber cables for CO laser medical applications

NASA Astrophysics Data System (ADS)

Arai, Tsunenori; Mizuno, Kyoichi; Sensaki, Koji; Kikuchi, Makoto; Watanabe, Tamishige; Utsumi, Atsushi; Takeuchi, Kiyoshi; Akai, Yoshiro

1993-05-01

We developed the medical fiber cables which were designed for CO laser therapy, i.e., angioplasty and endoscopic therapy. As-S chalcogenide glass fibers were used for CO laser delivery. A 230 micrometers core-diameter fiber was used for the angioplasty laser cable. The outer diameter of this cable was 600 micrometers . The total length and insertion length of the angioplasty laser cable were 2.5 m and 1.0 m, respectively. Typically, 2.0 W of fiber output was used in the animal experiment in vivo for the ablation of the model plaque which consisted of human atheromatous aorta wall. The transmission of the angioplasty laser cable was approximately 35%, because the reflection loss occurred at both ends of the fiber and window. Meanwhile, the core diameter of the energy delivery fiber for the endoscopic therapy was 450 micrometers . The outer diameter of this cable was 1.7 mm. Approximately 4.5 W of fiber output was used for clinical treatment of pneumothorax through a pneumoscope. Both types of the cables had the ultra-thin thermocouples for temperature monitoring at the tip of the cables. This temperature monitoring was extremely useful to prevent the thermal destruction of the fiber tip. Moreover, the As-S glass fibers were completely sealed by the CaF2 windows and outer tubes. Therefore, these cables were considered to have sufficient safety properties for medical applications. These laser cables were successfully used for the in vivo animal experiments and/or actual clinical therapies.

Fire behavior of halogen-free flame retardant electrical cables with the cone calorimeter.

PubMed

Meinier, Romain; Sonnier, Rodolphe; Zavaleta, Pascal; Suard, Sylvain; Ferry, Laurent

2018-01-15

Fires involving electrical cables are one of the main hazards in Nuclear Power Plants (NPPs). Cables are complex assemblies including several polymeric parts (insulation, bedding, sheath) constituting fuel sources. This study provides an in-depth characterization of the fire behavior of two halogen-free flame retardant cables used in NPPs using the cone calorimeter. The influence of two key parameters, namely the external heat flux and the spacing between cables, on the cable fire characteristics is especially investigated. The prominent role of the outer sheath material on the ignition and the burning at early times was highlighted. A parameter of utmost importance called transition heat flux, was identified and depends on the composition and the structure of the cable. Below this heat flux, the decomposition is limited and concerns only the sheath. Above it, fire hazard is greatly enhanced because most often non-flame retarded insulation part contributes to heat release. The influence of spacing appears complex, and depends on the considered fire property. Copyright © 2017 Elsevier B.V. All rights reserved.

Dynamic analysis of suspension cable based on vector form intrinsic finite element method

NASA Astrophysics Data System (ADS)

Qin, Jian; Qiao, Liang; Wan, Jiancheng; Jiang, Ming; Xia, Yongjun

2017-10-01

A vector finite element method is presented for the dynamic analysis of cable structures based on the vector form intrinsic finite element (VFIFE) and mechanical properties of suspension cable. Firstly, the suspension cable is discretized into different elements by space points, the mass and external forces of suspension cable are transformed into space points. The structural form of cable is described by the space points at different time. The equations of motion for the space points are established according to the Newton’s second law. Then, the element internal forces between the space points are derived from the flexible truss structure. Finally, the motion equations of space points are solved by the central difference method with reasonable time integration step. The tangential tension of the bearing rope in a test ropeway with the moving concentrated loads is calculated and compared with the experimental data. The results show that the tangential tension of suspension cable with moving loads is consistent with the experimental data. This method has high calculated precision and meets the requirements of engineering application.

High-Resolution Monitoring of Soil Water Dynamics in a Vegetated Hillslope by Active Distributed Temperature Sensing

NASA Astrophysics Data System (ADS)

Ciocca, F.; Krause, S.; Blaen, P.; Hannah, D. M.; Chalari, A.; Mondanos, M.; Abesser, C.

2016-12-01

Water and thermal conditions in the shallow vadose zone can be very complex and dynamic across a range of spatiotemporal scales. The efficient analysis of such dynamics requires technologies capable of precise and high-resolution monitoring of soil temperature and moisture across multiple scales. Optical fibre distributed temperature sensors (DTS) allows for precise temperature measurements at high spatio-temporal resolution, over several kilometres of optical fibre cable. In addition to passive temperature monitoring, hybrid optical cables with embedded metal conductors can be electrically heated and allow for distributed heat pulses. Such Active-DTS technique involves the analysis of temperatures during both heating and cooling phases of an optical fibre cable buried in the soil in order to provide distributed soil moisture estimates. In summer 2015, three loops of a 500m hybrid-optical cable have been deployed at 10cm, 25cm and 40cm depths along a hillslope with juvenile forest. Active-DTS surveys have been conducted with the aim to: (i) monitor the post-installation soil settling around the cable; (ii) analyse different heating strategies (intensity, duration) of the cable; (iii) establish a method for inferring soil moisture from Active-DTS results and validate with independent soil moisture readings from point probes; (iv) monitor the soil moisture response to short forcing events such as storms and artificial irrigation. Results from the surveys will be presented, and first assumptions on how the obtained soil water dynamics can be associated to specific triggers such as precipitation, evapotranspiration, soil inclination, will be discussed. This research is part of the British National Environmental Research Council (NERC) funded Distributed intelligent Heat Pulse System (DiHPS) project and is realised in the context of the Free Air Carbon Enrichment (FACE) experiment, in collaboration with the Birmingham Institute of Forest Research (BIFoR).

Corrosion study on high power feeding of telecomunication copper cable in 5 wt.% CaSO4.2H2O solution

NASA Astrophysics Data System (ADS)

Shamsudin, Shaiful Rizam; Hashim, Nabihah; Ibrahim, Mohd Saiful Bahri; Rahman, Muhammad Sayuzi Abdul; Idrus, Muhammad Amin; Hassan, Mohd Rezadzudin; Abdullah, Wan Razli Wan

2016-07-01

The studies were carried out to find out the best powering scheme over the copper telephone line. It was expected that the application of the higher power feeding could increase the data transfer and capable of providing the customer's satisfaction. To realize the application of higher remote power feeding, the potential of corrosion problem on Cu cables was studied. The natural corrosion behaviour of copper cable in the 0.5% CaSO4.2H2O solution was studied in term of open circuit potential for 30 days. The corrosion behaviour of higher power feeding was studied by the immersion and the planned interval test to determine the corrosion rate as well as the effect of voltage magnitudes and the current scheme i.e. positive direct (DC+) and alternating current (AC) at about 0.40 ± 0.01 mA/ cm2 current density. In the immersion test, both DC+ and AC scheme showed the increasing of feeding voltage magnitude has increased the corrosion rate of Cu samples starting from 60 to 100 volts. It was then reduced at about 100 - 120 volts which may due to the passive and transpassive mechanism. The corrosion rate was slowly reduced further from 120 to 200 volts. Visually, the positively charged of Cu cable was seems susceptible to severe corrosion, while AC scheme exhibited a slight corrosion reaction on the surface. However, the planned interval test and XRD results showed the corrosion activity of the copper cable in the studied solution was a relatively slow process and considered not to be corroded as a partially protective scale of copper oxide formed on the surface.

Space science/space station attached payload pointing accommodation study: Technology assessment white paper

NASA Technical Reports Server (NTRS)

Lin, Richard Y.; Mann, Kenneth E.; Laskin, Robert A.; Sirlin, Samuel W.

1987-01-01

Technology assessment is performed for pointing systems that accommodate payloads of large mass and large dimensions. Related technology areas are also examined. These related areas include active thermal lines or power cables across gimbals, new materials for increased passive damping, tethered pointing, and inertially reacting pointing systems. Conclusions, issues and concerns, and recommendations regarding the status and development of large pointing systems for space applications are made based on the performed assessments.

A Hybrid LCC-VSC HVDC Transmission System Supplying a Passive Load

NASA Astrophysics Data System (ADS)

Kotb, Omar

High Voltage Direct Current (HVDC) transmission systems continue to be an excellent asset in modern power systems, mainly for their ability to overcome the problems of AC transmission, such as the interconnection of asynchronous grids, stability of long transmission lines, and use of long cables for power transmission. In the past 20 years, Voltage Source Converter (VSC)-HVDC transmission systems were developed and installed in many projects, thereby adding more operational benefits to DC transmission option, such as high controllability, ability to supply weak networks, and reduced converter reactive power demand. Nevertheless, VSC-HVDC transmission suffers from the disadvantages of high losses and cost. In this research, a hybrid HVDC employing a Line Commutated Converter (LCC) as rectifier and a VSC as inverter is used to supply a passive network through a DC cable. The hybrid system is best suited for unidirectional power transmission scenarios, such as power transmission to islands and remote load centers, where the construction of new transmission lines is prohibitively expensive. Control modes for the rectifier and inverter are selected and implemented using Proportional Integral (PI) controllers. Special control schemes are developed for abnormal operating conditions such as starting at light load and recovering from AC network faults. The system performance under steady state and transient conditions is investigated by EMTP-RV simulations. The results show the feasibility of the hybrid system.

Quartz crystal resonator g sensitivity measurement methods and recent results

NASA Astrophysics Data System (ADS)

Driscoll, M. M.

1990-09-01

A technique for accurate measurements of quartz crystal resonator vibration sensitivity is described. The technique utilizes a crystal oscillator circuit in which a prescribed length of coaxial cable is used to connect the resonator to the oscillator sustaining stage. A method is provided for determination and removal of measurement errors normally introduced as a result of cable vibration. In addition to oscillator-type measurements, it is also possible to perform similar vibration sensitivity measurements using a synthesized signal generator with the resonator installed in a passive phase bridge. Test results are reported for 40 and 50 MHz, fifth overtone AT-cut, and third overtone SC-cut crystals. Acceleration sensitivity (gamma vector) values for the SC-cut resonators were typically four times smaller (5 x 10 to the -10th/g) than for the AT-cut units. However, smaller unit-to-unit gamma vector magnitude variation was exhibited by the AT-cut resonators.

Development and evaluation of thin semi-rigid cables for superconducting detectors

NASA Astrophysics Data System (ADS)

Kasai, Soichi; Kushino, Akihiro

2015-03-01

We are developing semi-rigid cables for accurate readout of superconducting radiation/particle detectors and other low temperature experiments. The center conductor with a diameter of 0.86 mm is separated with seamless metal outer conductor by dielectric material, polytetrafluoroethylene. We used various metal materials with low thermal conductivity for the electrical conductors such as stainless-steel, cupro-nickel, brass, beryllium-copper, phosphor-bronze, niobium-titanium, and niobium. In addition to the conventional semi-rigid cables, low-pass-filter-type cables were manufactured and evaluated to cut the high frequency noise into superconducting detectors. We measured their low thermal conductance and attenuation property up to 10GHz below the liquid helium temperature.

Development of semi-rigid cables for low temperature superconducting detectors

NASA Astrophysics Data System (ADS)

Kushino, Akihiro; Kasai, Soichi

We are developing semi-rigid cables for accurate readout of superconducting radiation/particle detectors and other low temperature experiments. The center conductor with a diameter of 0.86 mm is separated with seamless metal outer conductor by dielectric material, polytetrafluoroethylene. We used various metal materials with low thermal conductivity for the electrical conductors such as stainless-steel, cupro-nickel, brass, beryllium-copper, phosphor-bronze, niobium-titanium, and niobium. In addition to the conventional semi-rigid cables, low-pass-filter type cables were manufactured and evaluated to cut the high frequency noise into superconducting detectors. We measured their low thermal conductance and attenuation property up to 10 GHz below the liquid helium temperature.

Electro-mechanical characterization of MgB2 wires for the Superconducting Link Project at CERN

NASA Astrophysics Data System (ADS)

Konstantopoulou, K.; Ballarino, A.; Gharib, A.; Stimac, A.; Garcia Gonzalez, M.; Perez Fontenla, A. T.; Sugano, M.

2016-08-01

In previous years, the R & D program between CERN and Columbus Superconductors SpA led to the development of several configurations of MgB2 wires. The aim was to achieve excellent superconducting properties in high-current MgB2 cables for the HL-LHC upgrade. In addition to good electrical performance, the superconductor shall have good mechanical strength in view of the stresses during operation (Lorenz forces and thermal contraction) and handling (tension and bending) during cabling and installation at room temperature. Thus, the study of the mechanical properties of MgB2 wires is crucial for the cable design and its functional use. In the present work we report on the electro-mechanical characterization of ex situ processed composite MgB2 wires. Tensile tests (critical current versus strain) were carried out at 4.2 K and in a 3 T external field by means of a purpose-built bespoke device to determine the irreversible strain limit of the wire. The minimum bending radius of the wire was calculated taking into account the dependence of the critical current with the strain and it was then used to obtain the minimum twist pitch of MgB2 wires in the cable. Strands extracted from cables having different configurations were tested to quantify the critical current degradation. The Young’s modulus of the composite wire was measured at room temperature. Finally, all measured mechanical parameters will be used to optimize an 18-strand MgB2 cable configuration.

Preparation and Dielectric Properties of SiC/LSR Nanocomposites for Insulation of High Voltage Direct Current Cable Accessories

PubMed Central

Shang, Nanqiang; Chen, Qingguo; Wei, Xinzhe

2018-01-01

The conductivity mismatch in the composite insulation of high voltage direct current (HVDC) cable accessories causes electric field distribution distortion and even insulation breakdown. Therefore, a liquid silicone rubber (LSR) filled with SiC nanoparticles is prepared for the insulation of cable accessories. The micro-morphology of the SiC/LSR nanocomposites is observed by scanning electron microscopy, and their trap parameters are characterized using thermal stimulated current (TSC) tests. Moreover, the dielectric properties of SiC/LSR nanocomposites with different SiC concentrations are tested. The results show that the 3 wt % SiC/LSR sample has the best nonlinear conductivity, more than one order of magnitude higher than that of pure LSR with improved temperature and nonlinear conductivity coefficients. The relative permittivity increased 0.2 and dielectric loss factor increased 0.003, while its breakdown strength decreased 5 kV/mm compared to those of pure LSR. Moreover, the TSC results indicate the introduction of SiC nanoparticles reduced the trap level and trap density. Furthermore, the SiC nanoparticles filling significantly increased the sensitivity of LSR to electric field stress and temperature changes, enhancing the conductivity and electric field distribution within the HVDC cable accessories, thus improving the reliability of the HVDC cable accessories. PMID:29518054

Stabilisation of cables of fibronectin with micromolar concentrations of copper: in vitro cell substrate properties.

PubMed

Ahmed, Zubair; Briden, Anita; Hall, Susan; Brown, Robert A

2004-02-01

We have previously described the production of large cables of fibronectin, a large extracellular matrix cell adhesion glycoprotein, which has a potential application in tissue engineering. Here we have stabilised these cables for longer survival and looked at their ultrastructural cell-substrate behaviour in vitro. Dissolution experiments showed that low concentrations of copper not only caused significant material stabilisation but left pores which could promote cell ingrowth, as we have previously reported with Fn-mats. Indeed, the greatest amount of cell ingrowth was observed for copper treated cables. Immunostaining showed S-100(+) multi-layers of cells around the edge of cables while ultrastructural analysis confirmed the presence of a mixture of fibroblasts and bipolar cells associated with fragments of basal lamina, which is a Schwann cell phenotype. Interestingly, the outermost layers of cells consisted of S-100(-) cells, presumed fibroblasts, apparently 'capping' the Schwann cells. Toxicity tests revealed that Schwann cells were only able to grow at the lowest concentration of copper used (1microM) while fibroblasts grew at all concentrations tested. These results could be used to design biomaterials with optimum properties for promoting cellular ingrowth and survival in tissue engineered grafts which may be used to improve peripheral nerve repair.

Preparation and Dielectric Properties of SiC/LSR Nanocomposites for Insulation of High Voltage Direct Current Cable Accessories.

PubMed

Shang, Nanqiang; Chen, Qingguo; Wei, Xinzhe

2018-03-08

The conductivity mismatch in the composite insulation of high voltage direct current (HVDC) cable accessories causes electric field distribution distortion and even insulation breakdown. Therefore, a liquid silicone rubber (LSR) filled with SiC nanoparticles is prepared for the insulation of cable accessories. The micro-morphology of the SiC/LSR nanocomposites is observed by scanning electron microscopy, and their trap parameters are characterized using thermal stimulated current (TSC) tests. Moreover, the dielectric properties of SiC/LSR nanocomposites with different SiC concentrations are tested. The results show that the 3 wt % SiC/LSR sample has the best nonlinear conductivity, more than one order of magnitude higher than that of pure LSR with improved temperature and nonlinear conductivity coefficients. The relative permittivity increased 0.2 and dielectric loss factor increased 0.003, while its breakdown strength decreased 5 kV/mm compared to those of pure LSR. Moreover, the TSC results indicate the introduction of SiC nanoparticles reduced the trap level and trap density. Furthermore, the SiC nanoparticles filling significantly increased the sensitivity of LSR to electric field stress and temperature changes, enhancing the conductivity and electric field distribution within the HVDC cable accessories, thus improving the reliability of the HVDC cable accessories.

Measurement of rock mass deformation with grouted coaxial antenna cables

NASA Astrophysics Data System (ADS)

Dowding, C. H.; Su, M. B.; O'Connor, K.

1989-01-01

Techniques presented herein show how reflected voltage pulses from coaxial antenna cable grouted in rock masses can be employed to quantify the type and magnitude of rock mass deformation. This measurement is similar to that obtained from a combined full profile extensometer (to measure local extension) and inclinometer (to measure local shearing). Rock mass movements deform the grouted cable, which locally changes cable capacitance and thereby the reflected wave form of the voltage pulse. Thus, by monitoring changes in these reflection signatures, it is possible to monitor rock mass deformation. This paper presents laboratory measurements necessary to quantitatively interpret the reflected voltage signatures. Cables were sheared and extended to correlate measured cable deformation with reflected voltage signals. Laboratory testing included development of grout mixtures with optimum properties for field installation and performance of a TDR (Time Domain Reflectometry) monitoring system. Finally, the interpretive techniques developed through laboratory measurements were applied to previously collected field data to extract hitherto unrealized information.

High-power fiber optic cable with integrated active sensors for live process monitoring

NASA Astrophysics Data System (ADS)

Blomster, Ola; Blomqvist, Mats; Bergstrand, Hans; Pålsson, Magnus

2012-03-01

In industrial applications using high-brilliance lasers at power levels up to and exceeding 20 kW and similarly direct diode lasers of 10 kW, there is an increasing demand to continuously monitor component status even in passive components such as fiber-optic cables. With fiber-optic cables designed according to the European Automotive Industry fiber standard interface there is room for integrating active sensors inside the connectors. In this paper we present the integrated active sensors in the new Optoskand QD fiber-optic cable designed to handle extreme levels of power losses, and how these sensors can be employed in industrial manufacturing. The sensors include photo diodes for detection of scattered light inside the fiber connector, absolute temperature of the fiber connector, difference in temperature of incoming and outgoing cooling water, and humidity measurement inside the fiber connector. All these sensors are connected to the fiber interlock system, where interlock break enable functions can be activated when measured signals are higher than threshold levels. It is a very fast interlock break system as the control of the signals is integrated in the electronics inside the fiber connector. Also, since all signals can be logged it is possible to evaluate what happened inside the connector before the interlock break instance. The communication to the fiber-optic connectors is via a CAN interface. Thus it is straightforward to develop the existing laser host control to also control the CAN-messages from the QD sensors.

A Trigger Residue for Transmembrane Signaling in the Escherichia coli Serine Chemoreceptor.

PubMed

Kitanovic, Smiljka; Ames, Peter; Parkinson, John S

2015-08-01

The transmembrane Tsr protein of Escherichia coli mediates chemotactic responses to environmental serine gradients. Serine binds to the periplasmic domain of the homodimeric Tsr molecule, promoting a small inward displacement of one transmembrane helix (TM2). TM2 piston displacements, in turn, modulate the structural stability of the Tsr-HAMP domain on the cytoplasmic side of the membrane to control the autophosphorylation activity of the signaling CheA kinase bound to the membrane-distal cytoplasmic tip of Tsr. A five-residue control cable segment connects TM2 to the AS1 helix of HAMP and transmits stimulus and sensory adaptation signals between them. To explore the possible role of control cable helicity in transmembrane signaling by Tsr, we characterized the signaling properties of mutant receptors with various control cable alterations. An all-alanine control cable shifted Tsr output toward the kinase-on state, whereas an all-glycine control cable prevented Tsr from reaching either a fully on or fully off output state. Restoration of the native isoleucine (I214) in these synthetic control cables largely alleviated their signaling defects. Single amino acid replacements at Tsr-I214 shifted output toward the kinase-off (L, N, H, and R) or kinase-on (A and G) states, whereas other control cable residues tolerated most amino acid replacements with little change in signaling behavior. These findings indicate that changes in control cable helicity might mediate transitions between the kinase-on and kinase-off states during transmembrane signaling by chemoreceptors. Moreover, the Tsr-I214 side chain plays a key role, possibly through interaction with the membrane interfacial environment, in triggering signaling changes in response to TM2 piston displacements. The Tsr protein of E. coli mediates chemotactic responses to environmental serine gradients. Stimulus signals from the Tsr periplasmic sensing domain reach its cytoplasmic kinase control domain through piston displacements of a membrane-spanning helix and an adjoining five-residue control cable segment. We characterized the signaling properties of Tsr variants to elucidate the transmembrane signaling role of the control cable, an element present in many microbial sensory proteins. Both the kinase-on and kinase-off output states of Tsr depended on control cable helicity, but only one residue, I214, was critical for triggering responses to attractant inputs. These findings suggest that signal transmission in Tsr involves modulation of control cable helicity through interaction of the I214 side chain with the cytoplasmic membrane. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

A Trigger Residue for Transmembrane Signaling in the Escherichia coli Serine Chemoreceptor

PubMed Central

Kitanovic, Smiljka; Ames, Peter

2015-01-01

ABSTRACT The transmembrane Tsr protein of Escherichia coli mediates chemotactic responses to environmental serine gradients. Serine binds to the periplasmic domain of the homodimeric Tsr molecule, promoting a small inward displacement of one transmembrane helix (TM2). TM2 piston displacements, in turn, modulate the structural stability of the Tsr-HAMP domain on the cytoplasmic side of the membrane to control the autophosphorylation activity of the signaling CheA kinase bound to the membrane-distal cytoplasmic tip of Tsr. A five-residue control cable segment connects TM2 to the AS1 helix of HAMP and transmits stimulus and sensory adaptation signals between them. To explore the possible role of control cable helicity in transmembrane signaling by Tsr, we characterized the signaling properties of mutant receptors with various control cable alterations. An all-alanine control cable shifted Tsr output toward the kinase-on state, whereas an all-glycine control cable prevented Tsr from reaching either a fully on or fully off output state. Restoration of the native isoleucine (I214) in these synthetic control cables largely alleviated their signaling defects. Single amino acid replacements at Tsr-I214 shifted output toward the kinase-off (L, N, H, and R) or kinase-on (A and G) states, whereas other control cable residues tolerated most amino acid replacements with little change in signaling behavior. These findings indicate that changes in control cable helicity might mediate transitions between the kinase-on and kinase-off states during transmembrane signaling by chemoreceptors. Moreover, the Tsr-I214 side chain plays a key role, possibly through interaction with the membrane interfacial environment, in triggering signaling changes in response to TM2 piston displacements. IMPORTANCE The Tsr protein of E. coli mediates chemotactic responses to environmental serine gradients. Stimulus signals from the Tsr periplasmic sensing domain reach its cytoplasmic kinase control domain through piston displacements of a membrane-spanning helix and an adjoining five-residue control cable segment. We characterized the signaling properties of Tsr variants to elucidate the transmembrane signaling role of the control cable, an element present in many microbial sensory proteins. Both the kinase-on and kinase-off output states of Tsr depended on control cable helicity, but only one residue, I214, was critical for triggering responses to attractant inputs. These findings suggest that signal transmission in Tsr involves modulation of control cable helicity through interaction of the I214 side chain with the cytoplasmic membrane. PMID:26013490

Towards aging mechanisms of cross-linked polyethylene (XLPE) cable insulation materials in nuclear power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Shuaishuai; Fifield, Leonard S.; Bowler, Nicola

Cross-linked polyethylene (XLPE) cable insulation material undergoes simultaneous, accelerated thermal and gamma-radiation aging to simulate the long-term aging environment within nuclear power plants (NPPs). A variety of materials characterization tests, including scanning electron microscopy, thermo-gravimetric analysis, differential scanning calorimetry, oxidation induction time, gel-fraction and dielectric properties measurement, are conducted on pristine and differently aged XLPE samples. A preliminary model of one possible aging mechanism of XLPE cable insulation material under gamma radiation at elevated temperature of 115 °C is suggested.

Rapid optimization of tension distribution for cable-driven parallel manipulators with redundant cables

NASA Astrophysics Data System (ADS)

Ouyang, Bo; Shang, Weiwei

2016-03-01

The solution of tension distributions is infinite for cable-driven parallel manipulators(CDPMs) with redundant cables. A rapid optimization method for determining the optimal tension distribution is presented. The new optimization method is primarily based on the geometry properties of a polyhedron and convex analysis. The computational efficiency of the optimization method is improved by the designed projection algorithm, and a fast algorithm is proposed to determine which two of the lines are intersected at the optimal point. Moreover, a method for avoiding the operating point on the lower tension limit is developed. Simulation experiments are implemented on a six degree-of-freedom(6-DOF) CDPM with eight cables, and the results indicate that the new method is one order of magnitude faster than the standard simplex method. The optimal distribution of tension distribution is thus rapidly established on real-time by the proposed method.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kertzscher, G; Beddar, S

Purpose: To study the promising potential of inorganic scintillator detectors (ISDs) and investigate various unwanted luminescence properties which may compromise their accuracy. Methods: The ISDs were comprised of a ruby crystal coupled to a polymethyl methacrylate (PMMA) fiber-optic cable and a charged coupled device camera. A new type of ISD was manufactured and included a long-pass filter that was sandwiched between the crystal and the fiber-optic cable. The purpose of the filter was to suppress the Cerenkov and fluorescence background light induced in the PMMA (the stem signal) from striking the ruby crystal, generating unwanted ruby excitation. A variety ofmore » experiments were performed to characterize the ruby based ISDs. The relative contribution of the induced ruby signal and the stem signal were quantified while exposing the detector and a bare fiber-optic cable to a high dose rate (HDR) brachytherapy (BT) source, respectively. The unwanted ruby excitation was quantified while irradiating the fiber-optic cable with the detector volume shielded. Other experiments addressed time-dependent luminescence properties and a comparison to other commonly used organic scintillator detectors (BCF-12, BCF-60). Results: When the BT source dwelled 0.5 cm away from the fiber-optic cable, the unwanted ruby excitation amounted to >5% of the total signal if the source-distance from the scintillator was >7 cm. However, the unwanted excitation was suppressed to <1% if the ISD incorporated an optic filter. The stem signal was suppressed with a 20 nm band-pass filter and was <3% as long as the source-distance was <7 cm. The ruby based ISDs generated signal up to 20(40) times that of BCF-12(BCF-60). Conclusion: The study presents solutions to unwanted luminescence properties of ruby based ISDs for HDR BT. An optic filter should be sandwiched between the scintillator volume and the fiber-optic cable to prevent the stem signal to excite the ruby crystal.« less

Thermo-Mechanical Behavior and Shakedown of Shape Memory Alloy Cable Structures

NASA Astrophysics Data System (ADS)

Biggs, Daniel B.

Shape memory alloys (SMAs) are a versatile class of smart materials that exhibit adaptive properties which have been applied to solve engineering problems in wide-ranging fields from aerospace to biomedical engineering. Yet there is a lack of understanding of the fundamental nature of SMAs in order to effectively apply them to challenging problems within these engineering fields. Stranding fine NiTi wires into a cable form satisfies the demands of many aerospace and civil engineering applications which require actuators to withstand large tensile loads. The impact of increased bending and twisting in stranded NiTi wire structures, as well as introducing contact mechanics to the unstable phase transformation is not well understood, and this work aims to fill that void. To study the scalability of NiTi cables, thermo-mechanical characterization tests are conducted on cables much larger than those previously tested. These cables are found to have good superelastic properties and repeatable cyclic behavior with minimal induced plasticity. The behavior of additional cables, which have higher transition temperatures that can be used in a shape memory mode as thermo-responsive, high force actuator elements, are explored. These cables are found to scale up the performance of straight wire by maintaining an equivalent work output. Moreover, this work investigates the degradation of the thermal actuation of SMA wires through novel stress-temperature paths, discovering several path dependent behaviors of transformation-induced plasticity. The local mechanics of NiTi cable structures are explored through experiments utilizing digital image correlation, revealing new periodic transformation instabilities. Finite element simulations are presented, which indicate that the instabilities are caused by friction and relative sliding between wires in a cable. Finally, a study of the convective heat transfer of helical wire involving a suite of wind tunnel experiments, numerical analyses, and an empirical correlation is presented. This provides a method to better model the thermal behavior of helical SMA actuators and highlights the non-monotonic dependence of the convective heat transfer coefficient of helical wire with respect to the angle of the flow.

Actin cable distribution and dynamics arising from cross-linking, motor pulling, and filament turnover

PubMed Central

Tang, Haosu; Laporte, Damien; Vavylonis, Dimitrios

2014-01-01

The growth of fission yeast relies on the polymerization of actin filaments nucleated by formin For3p, which localizes at tip cortical sites. These actin filaments bundle to form actin cables that span the cell and guide the movement of vesicles toward the cell tips. A big challenge is to develop a quantitative understanding of these cellular actin structures. We used computer simulations to study the spatial and dynamical properties of actin cables. We simulated individual actin filaments as semiflexible polymers in three dimensions composed of beads connected with springs. Polymerization out of For3p cortical sites, bundling by cross-linkers, pulling by type V myosin, and severing by cofilin are simulated as growth, cross-linking, pulling, and turnover of the semiflexible polymers. With the foregoing mechanisms, the model generates actin cable structures and dynamics similar to those observed in live-cell experiments. Our simulations reproduce the particular actin cable structures in myoVΔ cells and predict the effect of increased myosin V pulling. Increasing cross-linking parameters generates thicker actin cables. It also leads to antiparallel and parallel phases with straight or curved cables, consistent with observations of cells overexpressing α-actinin. Finally, the model predicts that clustering of formins at cell tips promotes actin cable formation. PMID:25103242

KSC-98pc1659

NASA Image and Video Library

1998-11-06

Workers in the Space Station Processing Facility watch as cables and a crane lift the Passive Common Berthing Mechanism (PCBM) before mating it to the Z1 integrated truss structure, a component of the International Space Station (ISS). The Z1 truss will be used for the temporary installation of the P6 truss segment to the Unity connecting module. The P6 truss segment contains the solar arrays and batteries which will provide early station power. The truss is scheduled to be launched aboard STS-92 in late 1999

Frequency Domain Reflectometry NDE for Aging Cables in Nuclear Power Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glass, Samuel W.; Jones, Anthony M.; Fifield, Leonard S.

Cable insulation polymers are among the more susceptible materials to age-related degradation within a nuclear power plant. This is recognized by both regulators and utilities, so all plants have developed cable aging management programs to detect damage before critical component failure in compliance with regulatory guidelines. Although a wide range of tools are available to evaluate cables and cable systems, cable aging management programs vary in how condition monitoring and nondestructive examinations are conducted as utilities search for the most reliable and cost-effective ways to assess cable system condition. Frequency domain reflectometry (FDR) is emerging as one valuable tool tomore » locate and assess damaged portions of a cable system with minimal cost and only requires access in most cases to one of the cable terminal ends. Since laboratory studies to evaluate the use of FDR for inspection of aged cables can be expensive and data interpretation may be confounded by multiple factors which influence results, a model-based approach is desired to parametrically investigate the effect of insulation material damage in a controlled manner. This work describes development of a physics-based FDR model which uses finite element simulations of cable segments in conjunction with cascaded circuit element simulations to efficiently study a cable system. One or more segments of the cable system model have altered physical or electrical properties which represent the degree of damage and the location of the damage in the system. This circuit model is then subjected to a simulated FDR examination. The modeling approach is verified using several experimental cases and by comparing it to a commercial simulator suitable for simulation of some cable configurations. The model is used to examine a broad range of parameters including defect length, defect profile, degree of degradation, number and location of defects, FDR bandwidth, and addition of impedance-matched extensions to minimize the end-shadow effect.« less

Frequency domain reflectometry modeling for nondestructive evaluation of nuclear power plant cables

NASA Astrophysics Data System (ADS)

Glass, S. W.; Fifield, L. S.; Jones, A. M.; Hartman, T. S.

2018-04-01

Cable insulation polymers are among the more susceptible materials to age-related degradation within a nuclear power plant. This is recognized by both regulators and utilities, so all plants have developed cable aging management programs to detect damage before critical component failure in compliance with regulatory guidelines. Although a wide range of tools are available to evaluate cables and cable systems, cable aging management programs vary in how condition monitoring and nondestructive examinations are conducted as utilities search for the most reliable and cost-effective ways to assess cable system condition. Frequency domain reflectometry (FDR) is emerging as one valuable tool to locate and assess damaged portions of a cable system with minimal cost and only requires access in most cases to one of the cable terminal ends. Since laboratory studies to evaluate the use of FDR for inspection of aged cables can be expensive and data interpretation may be confounded by multiple factors which influence results, a model-based approach is desired to parametrically investigate the effect of insulation material damage in a controlled manner. This work describes development of a physics-based FDR model which uses finite element simulations of cable segments in conjunction with cascaded circuit element simulations to efficiently study a cable system. One or more segments of the cable system model have altered physical or electrical properties which represent the degree of damage and the location of the damage in the system. This circuit model is then subjected to a simulated FDR examination. The modeling approach is verified using several experimental cases and by comparing it to a commercial simulator suitable for simulation of some cable configurations. The model is used to examine a broad range of parameters including defect length, defect profile, degree of degradation, number and location of defects, FDR bandwidth, and addition of impedance-matched extensions to minimize the end-shadow effect.

Production of Aluminum Stabilized Superconducting Cable for the Mu2e Transport Solenoid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lombardo, Vito; Ambrosio, Giorgio; Evbota, Daniel

Here, the Fermilab Mu2e experiment, currently under construction at Fermilab, has the goal of measuring the rare process of direct muon to electron conversion in the field of a nucleus. The experiment features three large superconducting solenoids: the production solenoid (PS), the transport solenoid (TS), and the detector solenoid (DS). The TS is an “S-shaped” solenoid that sits in between the PS and the DS producing a magnetic field ranging between 2.5 and 2.0 T. This paper describes the various steps that led to the successful procurement of over 740 km of superconducting wire and 44 km of Al-stabilized Rutherfordmore » cable needed to build the 52 coils that constitute the Mu2e TS cold mass. The main cable properties and results of electrical and mechanical test campaigns are summarized and discussed. Critical current measurements of the Al-stabilized cables are presented and compared to expected critical current values as measured on extracted strands from the final cables after chemical etching of the aluminum stabilizer. A robust and reliable approach to cable welding is presented, and the effect of cable bending on the transport current is also investigated and presented.« less

Production of Aluminum Stabilized Superconducting Cable for the Mu2e Transport Solenoid

DOE PAGES

Lombardo, Vito; Ambrosio, Giorgio; Evbota, Daniel; ...

2018-01-15

Here, the Fermilab Mu2e experiment, currently under construction at Fermilab, has the goal of measuring the rare process of direct muon to electron conversion in the field of a nucleus. The experiment features three large superconducting solenoids: the production solenoid (PS), the transport solenoid (TS), and the detector solenoid (DS). The TS is an “S-shaped” solenoid that sits in between the PS and the DS producing a magnetic field ranging between 2.5 and 2.0 T. This paper describes the various steps that led to the successful procurement of over 740 km of superconducting wire and 44 km of Al-stabilized Rutherfordmore » cable needed to build the 52 coils that constitute the Mu2e TS cold mass. The main cable properties and results of electrical and mechanical test campaigns are summarized and discussed. Critical current measurements of the Al-stabilized cables are presented and compared to expected critical current values as measured on extracted strands from the final cables after chemical etching of the aluminum stabilizer. A robust and reliable approach to cable welding is presented, and the effect of cable bending on the transport current is also investigated and presented.« less

An investigation of the curing process for moisture-crosslinkable polyethylene used in cable coating extrusion

NASA Astrophysics Data System (ADS)

Cantor, Kirk Martin

1998-12-01

Moisture-crosslinkable polyethylene used in the extrusion coating of electrical cable has many advantages over other polymer systems used for crosslinked cable coating. However, one of its major drawbacks is the long cure times required. The purpose of this study was to describe how curing takes place in cable systems using moisture-crosslinkable polyethylene, with an ultimate goal of gaining insight into how cure times might be reduced. Crosslinking was investigated with an emphasis on how the curing reaction proceeds through the coating, using analyses to characterize processing conditions and resulting mechanical and structural properties. In the design of the study, material compounds were varied as were curing conditions. Cable coatings were sectioned by position through the coating thickness and characterized using several techniques. Mechanical, thermal, and structural properties of the polymer coating were measured. A significant finding from the study was that the degree of cure was highest at positions in the coating closest to the conductor. Because this was opposite to what was expected, an investigation into the cause of this finding was pursued. It was found that during cure at elevated temperature, the inside surface of the coating remains at a generally higher temperature than the outside surface. This provides a more favorable cure condition for positions in the coating closest to the conductor. Based on the results of this study, a list of suggested follow-up studies is provided at the end of the dissertation. One proposal for investigating reduced cure times involves providing heat to the interior of the cable during cure.

The effect of age on hamstring passive properties after a 10-week stretch training

PubMed Central

Haab, Thomas; Wydra, Georg

2017-01-01

[Purpose] Degenerative changes take place in the musculoskeletal system of elderly people, resulting in a reduced range of motion. For this reason, stretch training is recommended for elderly individuals. To date, there have been no studies of the adaptations of the passive properties of muscles following long-term stretch training. The aim of this study is to investigate the hamstring elasticity of elderly people following a 10-week stretch training and compare the results to a younger cohort. [Subjects and Methods] The experimental groups consisted of 15 younger (24.0 ± 4.0 years) and 14 older (65.1 ± 7.9 years) individuals. Both experimental groups undertook a standardised 10-week static passive hamstring stretch training. Passive properties of the hamstring were measured with an instrumented Straight Leg Raise Test. [Results] After a 10-week stretch training, there were increases in range of motion, passive resistive force and passive elastic energy in both age groups. Passive elastic stiffness decreased. Changes of hamstring passive properties did not differ significantly between age groups after a 10-week stretch training. [Conclusion] Increasing age has a negative effect on muscle passive properties, but older individuals benefit from regular stretch training, just as younger individuals do. PMID:28626322

Final Report: MATERIALS, STRANDS, AND CABLES FOR SUPERCONDUCTING ACCELERATOR MAGNETS [Grant Number DE-SC0010312

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sumption, Mike D.; Collings, Edward W.

2014-10-29

Our program consisted of the two components: Strand Research and Cable Research, with a focus on Nb3Sn, Bi2212, and YBCO for accelerator magnet applications. We demonstrated a method to refine the grains in Nb3Sn by a factor of two, reaching 45 nm grain sizes, and layer Jcs of 6 kA/mm2 at 12 T. W also measured conductor magnetization for field quality. This has been done both with Nb3Sn conductor, as well as Bi:2212 strand. Work in support of quench studies of YBCO coils was also performed. Cable loss studies in Nb3Sn focused on connecting and comparing persistent magnetization and couplingmore » magnetization for considering their relative impact on HEP machines. In the area of HTS cables, we have investigated both the quench in multistrand YBCO CORC cables, as well as the magnetization of these cables for use in high field magnets. In addition, we examined the magnetic and thermal properties of large (50 T) solenoids.« less

Study on AC loss measurements of HTS power cable for standardizing

NASA Astrophysics Data System (ADS)

Mukoyama, Shinichi; Amemiya, Naoyuki; Watanabe, Kazuo; Iijima, Yasuhiro; Mido, Nobuhiro; Masuda, Takao; Morimura, Toshiya; Oya, Masayoshi; Nakano, Tetsutaro; Yamamoto, Kiyoshi

2017-09-01

High-temperature superconducting power cables (HTS cables) have been developed for more than 20 years. In addition of the cable developments, the test methods of the HTS cables have been discussed and proposed in many laboratories and companies. Recently the test methods of the HTS cables is required to standardize and to common in the world. CIGRE made the working group (B1-31) for the discussion of the test methods of the HTS cables as a power cable, and published the recommendation of the test method. Additionally, IEC TC20 submitted the New Work Item Proposal (NP) based on the recommendation of CIGRE this year, IEC TC20 and IEC TC90 started the standardization work on Testing of HTS AC cables. However, the individual test method that used to measure a performance of HTS cables hasn’t been established as world’s common methods. The AC loss is one of the most important properties to disseminate low loss and economical efficient HTS cables in the world. We regard to establish the method of the AC loss measurements in rational and in high accuracy. Japan is at a leading position in the AC loss study, because Japanese researchers have studied on the AC loss technically and scientifically, and also developed the effective technologies for the AC loss reduction. The JP domestic commission of TC90 made a working team to discussion the methods of the AC loss measurements for aiming an international standard finally. This paper reports about the AC loss measurement of two type of the HTS conductors, such as a HTS conductor without a HTS shield and a HTS conductor with a HTS shield. The AC loss measurement method is suggested by the electrical method..

Properties of plastic tapes for cryogenic power cable insulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muller, A C

1978-01-01

A superconducting ac power transmission cable is under development at Brookhaven National Laboratory (BNL). This project was undertaken in 1972 in response to growing national power requirements. The goal of this program is to develop an underground power transmission system suitable for transferring bulk quantities of electricity over distances of 16 to 160 km. Both the capital investment and operating costs must be low enough to make the system attractive to the electric utilities. The superconducting cable shares the advantages with conventional underground cables of needing only a few feet of right-of-way width rather than the large tracts of increasinglymore » expensive land required for conventional aerial transmission. Recent cost analysis studies show that superconducting cables, although more expensive than aerial transmission, will probably be competitive with other methods of underground transmission at loads greater than 2000 MVA. Initial design studies showed that a flexible, forced-cooled cable offered the best combination of technical and economic features. A helium cooled cable with Nb/sub 3/Sn superconductor was chosen as the BNL design. The present goal of the BNL program is the construction of a 100 meter outdoor three-phase ac cable rated at 138 kV and 1000 MVA. The refrigerator and the 100 m-long dewar are already installed. Terminations and cables are under design, and it is planned to begin installation of the first single phase cable in 1979. If the results on this model show promise for eventual commercial use, cables of higher voltage and power rating will be developed. One fundamental phase of this project; the development of the required insulating materials, is described.« less

Effects of core type, placement, and width on the estimated interstrand coupling properties of QXF-type Nb 3Sn Rutherford cables

DOE PAGES

Collings, E. W.; Sumption, M. D.; Majoros, M.; ...

2015-01-12

The coupling magnetization of a Rutherford cable is inversely proportional to an effective interstrand contact resistance R eff , a function of the crossing-strand resistance R c, and the adjacent strand resistance R a. In cored cables, R eff continuously varies with W, the core width expressed as percent interstrand cover. For a series of un-heat-treated stabrite-coated NbTi LHC-inner cables with stainless-steel (SS, insulating) cores, R eff (W) decreased smoothly as W decreased from 100%, whereas for a set of research-wound SS-cored Nb 3Sn cables, R eff plummeted abruptly and remained low over most of the range. The difference ismore » due to the controlling influence of R c - 2.5 μΩ for the stabrite/NbTi and 0.26 μΩ for Nb 3Sn. The experimental behavior was replicated in the R eff (W)’s calculated by the program CUDI, which (using the basic parameters of the QXF cable) went on to show in terms of decreasing W that: 1) in QXF-type Nb 3Sn cables (R c = 0.26 μΩ), R eff dropped even more suddenly when the SS core, instead of being centered, was offset to one edge of the cable; 2) R eff decreased more gradually in cables with higher R c’s; and 3) a suitable R eff for a Nb 3Sn cable can be achieved by inserting a suitably resistive core rather than an insulating (SS) one.« less

Franchise Fees and Public, Educational and Government (PEG) Access. Report to the Minnesota Legislature.

ERIC Educational Resources Information Center

Minnesota State Dept. of Public Service, St. Paul. Energy Div.

Franchise fees are a tax imposed on a private entity to compensate a municipality for use of a public property for private gain. The Telecommunications Act of 1996 grants municipalities the right to assess a 5% franchise fee to both cable companies and competitors of cable companies, such as operators of open video systems. The Minnesota State…

Statistical analysis of modal properties of a cable-stayed bridge through long-term structural health monitoring with wireless smart sensor networks

NASA Astrophysics Data System (ADS)

Asadollahi, Parisa; Li, Jian

2016-04-01

Understanding the dynamic behavior of complex structures such as long-span bridges requires dense deployment of sensors. Traditional wired sensor systems are generally expensive and time-consuming to install due to cabling. With wireless communication and on-board computation capabilities, wireless smart sensor networks have the advantages of being low cost, easy to deploy and maintain and therefore facilitate dense instrumentation for structural health monitoring. A long-term monitoring project was recently carried out for a cable-stayed bridge in South Korea with a dense array of 113 smart sensors, which feature the world's largest wireless smart sensor network for civil structural monitoring. This paper presents a comprehensive statistical analysis of the modal properties including natural frequencies, damping ratios and mode shapes of the monitored cable-stayed bridge. Data analyzed in this paper is composed of structural vibration signals monitored during a 12-month period under ambient excitations. The correlation between environmental temperature and the modal frequencies is also investigated. The results showed the long-term statistical structural behavior of the bridge, which serves as the basis for Bayesian statistical updating for the numerical model.

Density measurements as a condition monitoring approach for following the aging of nuclear power plant cable materials

NASA Astrophysics Data System (ADS)

Gillen, K. T.; Celina, M.; Clough, R. L.

1999-10-01

Monitoring changes in material density has been suggested as a potentially useful condition monitoring (CM) method for following the aging of cable jacket and insulation materials in nuclear power plants. In this study, we compare density measurements and ultimate tensile elongation results versus aging time for most of the important generic types of commercial nuclear power plant cable materials. Aging conditions, which include thermal-only, as well as combined radiation plus thermal, were chosen such that potentially anomalous effects caused by diffusion-limited oxidation (DLO) are unimportant. The results show that easily measurable density increases occur in most important cable materials. For some materials and environments, the density change occurs at a fairly constant rate throughout the mechanical property lifetime. For cases involving so-called induction-time behavior, density increases are slow to moderate until after the induction time, at which point they begin to increase dramatically. In other instances, density increases rapidly at first, then slows down. The results offer strong evidence that density measurements, which reflect property changes under both radiation and thermal conditions, could represent a very useful CM approach.

Passive Sensors for Long Duration Internet of Things Networks.

PubMed

Pereira, Felisberto; Correia, Ricardo; Carvalho, Nuno Borges

2017-10-03

In this work, three different concepts are used to develop a fully passive sensor that is capable of measuring different types of data. The sensor was supplied by Wireless Power Transmission (WPT). Communication between the sensor and reader is established by a backscatter, and to ensure minimum energy consumption, low power techniques are used. In a simplistic way, the process starts by the transmission of two different waves by the reader to the sensor, one of which is used in power transmission and the other of which is used to communicate. Once the sensor is powered, the monitoring process starts. From the monitoring state, results from after processing are used to modulate the incoming wave, which is the information that is sent back from the reader to the tag. This new combination of technologies enables the possibility of using sensors without any cables or batteries to operate 340 cm from the reader. The developed prototype measures acceleration and temperature. However, it is scalable. This system enables a new generation of passive Internet of Things (IoT) devices.

Passive Sensors for Long Duration Internet of Things Networks

PubMed Central

Correia, Ricardo; Carvalho, Nuno Borges

2017-01-01

In this work, three different concepts are used to develop a fully passive sensor that is capable of measuring different types of data. The sensor was supplied by Wireless Power Transmission (WPT). Communication between the sensor and reader is established by a backscatter, and to ensure minimum energy consumption, low power techniques are used. In a simplistic way, the process starts by the transmission of two different waves by the reader to the sensor, one of which is used in power transmission and the other of which is used to communicate. Once the sensor is powered, the monitoring process starts. From the monitoring state, results from after processing are used to modulate the incoming wave, which is the information that is sent back from the reader to the tag. This new combination of technologies enables the possibility of using sensors without any cables or batteries to operate 340 cm from the reader. The developed prototype measures acceleration and temperature. However, it is scalable. This system enables a new generation of passive Internet of Things (IoT) devices. PMID:28972554

Underwater fiber-wireless communication with a passive front end

NASA Astrophysics Data System (ADS)

Xu, Jing; Sun, Bin; Lyu, Weichao; Kong, Meiwei; Sarwar, Rohail; Han, Jun; Zhang, Wei; Deng, Ning

2017-11-01

We propose and experimentally demonstrate a novel concept on underwater fiber-wireless (Fi-Wi) communication system with a fully passive wireless front end. A low-cost step-index (SI) plastic optical fiber (POF) together with a passive collimating lens at the front end composes the underwater Fi-Wi architecture. We have achieved a 1.71-Gb/s transmission at a mean BER of 4.97 × 10-3 (1.30 × 10-3 when using power loading) over a 50-m SI-POF and 2-m underwater wireless channel using orthogonal frequency division multiplexing (OFDM). Although the wireless part is very short, it actually plays a crucial role in practical underwater implementation, especially in deep sea. Compared with the wired solution (e.g. using a 52-m POF cable without the UWOC part), the proposed underwater Fi-Wi scheme can save optical wet-mate connectors that are sophisticated, very expensive and difficult to install in deep ocean. By combining high-capacity robust POF with the mobility and ubiquity of underwater wireless optical communication (UWOC), the proposed underwater Fi-Wi technology will find wide application in ocean exploration.

Biomechanical analysis using FEA and experiments of a standard plate method versus three cable methods for fixing acetabular fractures with simultaneous THA.

PubMed

Aziz, Mina S R; Dessouki, Omar; Samiezadeh, Saeid; Bougherara, Habiba; Schemitsch, Emil H; Zdero, Radovan

2017-08-01

Acetabular fractures potentially account for up to half of all pelvic fractures, while pelvic fractures potentially account for over one-tenth of all human bone fractures. This is the first biomechanical study to assess acetabular fracture fixation using plates versus cables in the presence of a total hip arthroplasty, as done for the elderly. In Phase 1, finite element (FE) models compared a standard plate method versus 3 cable methods for repairing an acetabular fracture (type: anterior column plus posterior hemi-transverse) subjected to a physiological-type compressive load of 2207N representing 3 x body weight for a 75kg person during walking. FE stress maps were compared to choose the most mechanically stable cable method, i.e. lowest peak bone stress. In Phase 2, mechanical tests were then done in artificial hemipelvises to compare the standard plate method versus the optimal cable method selected from Phase 1. FE analysis results showed peak bone stresses of 255MPa (Plate method), 205MPa (Mears cable method), 250MPa (Kang cable method), and 181MPa (Mouhsine cable method). Mechanical tests then showed that the Plate method versus the Mouhsine cable method selected from Phase 1 had higher stiffness (662versus 385N/mm, p=0.001), strength (3210versus 2060N, p=0.009), and failure energy (8.8versus 6.2J, p=0.002), whilst they were statistically equivalent for interfragmentary sliding (p≥0.179) and interfragmentary gapping (p≥0.08). The Plate method had superior mechanical properties, but the Mouhsine cable method may be a reasonable alternative if osteoporosis prevents good screw thread interdigitation during plating. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Quartz crystal resonator g sensitivity measurement methods and recent results.

PubMed

Driscoll, M M

1990-01-01

A technique for accurate measurements of quartz crystal resonator vibration sensitivity is described. The technique utilizes a crystal oscillator circuit in which a prescribed length of coaxial cable is used to connect the resonator to the oscillator sustaining stage. A method is provided for determination and removal of measurement errors normally introduced as a result of cable vibration. In addition to oscillator-type measurements, it is also possible to perform similar vibration sensitivity measurements using a synthesized signal generator with the resonator installed in a passive phase bridge. Test results are reported for 40 and 50 MHz, fifth overtone AT-cut, and third overtone SC-cut crystals. Acceleration sensitivity (gamma vector) values for the SC-cut resonators were typically four times smaller (5x10(-10) per g) than for the AT-cut units. However, smaller unit-to-unit gamma vector magnitude variation was exhibited by the AT-cut resonators. Oscillator sustaining stage vibration sensitivity was characterized by an equivalent open-loop phase modulation of 10(-6) rad/g.

Improve the refractive index sensitivity of coaxial-cable type gold nanostructure: the effect of dielectric polarization from the separate layer

NASA Astrophysics Data System (ADS)

Zhu, Jian; Li, Jian-Jun; Zhao, Jun-Wu

2013-06-01

The separate layer refractive index sensitivity of a coaxial-cable type three-layered gold nanotube has been studied. Theoretical calculation results based on quasi-static model show that the coaxial-cable type gold nanostructure has higher refractive index sensitivity than that of single-layered gold nanotube. This sensitivity could be improved by increasing the inner wire radius or decreasing the total radius of the tube, and the maximum sensitivity may exceed 1,000 nm per refractive index unit. The physical origin was also investigated based on the coupling of the dielectric media induced polarizations and the local electric fields in separate layer and outer surrounding. These separate layer refractive index sensing properties of coaxial-cable type gold nanostructure present well potential for plasmonic biosensing applications.

Fractional cable equation models for anomalous electrodiffusion in nerve cells: infinite domain solutions.

PubMed

Langlands, T A M; Henry, B I; Wearne, S L

2009-12-01

We introduce fractional Nernst-Planck equations and derive fractional cable equations as macroscopic models for electrodiffusion of ions in nerve cells when molecular diffusion is anomalous subdiffusion due to binding, crowding or trapping. The anomalous subdiffusion is modelled by replacing diffusion constants with time dependent operators parameterized by fractional order exponents. Solutions are obtained as functions of the scaling parameters for infinite cables and semi-infinite cables with instantaneous current injections. Voltage attenuation along dendrites in response to alpha function synaptic inputs is computed. Action potential firing rates are also derived based on simple integrate and fire versions of the models. Our results show that electrotonic properties and firing rates of nerve cells are altered by anomalous subdiffusion in these models. We have suggested electrophysiological experiments to calibrate and validate the models.

Integrated arc suppression unit for defect reduction in PVD applications

NASA Astrophysics Data System (ADS)

Li, Jason; Narasimhan, Murali K.; Pavate, Vikram; Loo, David; Rosenblum, Steve; Trubell, Larry; Scholl, Richard; Seamons, Scott; Hagerty, Chris; Ramaswami, Sesh

1997-09-01

Arcing between the target and plasma during PVD deposition causes substantial damage to the target and splats and other contamination on the deposited films. Arc-related damages and defects are frequently encountered in microelectronics manufacturing and contributes largely to reduced wafer yields. Arcing is caused largely by the charge buildup at the contaminated sites on the target surface that contains either nonconducting inclusions or nodules. Arc suppression is a key issue for defect reduction, yield improvement and for reliable high quality metallization. An Integrated Arc Suppression Unit (IASU) has been designed for Endura HP PVDTM sputtering sources. The integrated design reduces cable length from unit to source and reduces electrical energy stored in the cable. Active arc handling mode, proactive arc prevention mode, and passive by-pass arc counting mode are incorporated into the same unit. The active mode is designed to quickly respond to chamber conditions, like a large chamber voltage drop, that signals a arc. The self run mode is designed to proactively prevent arc formation by pulsing and reversing target voltage at 50 kHz. The design of the IASU, also called mini small package arc repression circuit--low energy unit (mini Sparc-le), has been optimized for various DC magnetron sources, plasma stability, chamber impedance, power matching, CE MARK test, and power dissipation. Process characterization with Ti, TiN and Al sputtering indicates that the unit has little adverse impact on film properties. Mini Sparc-le unit has been shown here to significantly reduce splats occurrence in Al sputtering. Marathon test of the unit with Ti/TiN test demonstrated the unit's reliability and its ability to reduce sensitivity of defects to target characteristics.

Electrodynamics panel presentation

NASA Technical Reports Server (NTRS)

Mccoy, J.

1986-01-01

The Plasma Motor Generator (PMG) concept is explained in detail. The PMG tether systems being used to calculate the estimated performance data is described. The voltage drops and current contact geometries involved in the operation of an electrodynamic tether are displayed illustrating the comparative behavior of hollow cathodes, electron guns, and passive collectors for current coupling into the ionosphere. The basic PMG design involving the massive tether cable with little or no satellite mass at the far end(s) are also described. The Jupiter mission and its use of electrodynamic tethers are given. The need for demonstration experiments is stressed.

Design of ground test suspension systems for verification of flexible space structures

NASA Technical Reports Server (NTRS)

Cooley, V. M.; Juang, J. N.; Ghaemmaghami, P.

1988-01-01

A simple model demonstrates the frequency-increasing effects of a simple cable suspension on flexible test article/suspension systems. Two passive suspension designs, namely a negative spring mechanism and a rolling cart mechanism, are presented to alleviate the undesirable frequency-increasing effects. Analysis methods are provided for systems in which the augmentations are applied to both discrete and continuous representations of test articles. The damping analyses are based on friction equivalent viscous damping. Numerical examples are given for comparing the two augmentations with respect to minimizing frequency and damping increases.

Reduce Nb3Sn Strand Deformation when Fabricating High Jc Rutherford Cables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Xuan

2012-12-17

During Phase I, our efforts were to reduce subelements deformation when fabricating Nb3Sn Rutherford cables. Our first focus is on 217-sublement tube type strand. We successfully made a few billets in OD tube with different Cu spacing between subelements, and supplied the strands to Fermi Lab for cabling. Through the rolling test characterization, these types of strands did not have enough bonding between subelements to withstand the deformation. We saw copper cracking between subelements in the deformed strands. We scaled up the billet from OD to 1.5 OD, and made two billets. This greatly improves the bonding. There is nomore » copper cracking in the deformed strands when we scaled up the diameter of the billets. Fermi Lab successfully made cables using one of this improved strands. In their cables, no Cu cracking and no filament bridging occurred. We also successfully made a couple of billets with hex OD and round ID subelements for 61-subelement restack. Due to the lack of bonding, we could not judge its cabling property properly. But we know through this experiment, we could keep the Nb round, once we select the proper Cu spacing.« less

High frequency optoelectronic oscillators based on the optical feedback of semiconductor mode-locked laser diodes.

PubMed

Haji, Mohsin; Hou, Lianping; Kelly, Anthony E; Akbar, Jehan; Marsh, John H; Arnold, John M; Ironside, Charles N

2012-01-30

Optical self seeding feedback techniques can be used to improve the noise characteristics of passively mode-locked laser diodes. External cavities such as fiber optic cables can increase the memory of the phase and subsequently improve the timing jitter. In this work, an improved optical feedback architecture is proposed using an optical fiber loop delay as a cavity extension of the mode-locked laser. We investigate the effect of the noise reduction as a function of the loop length and feedback power. The well known composite cavity technique is also implemented for suppressing supermode noise artifacts presented due to harmonic mode locking effects. Using this method, we achieve a record low radio frequency linewidth of 192 Hz for any high frequency (>1 GHz) passively mode-locked laser to date (to the best of the authors' knowledge), making it promising for the development of high frequency optoelectronic oscillators.

Listening to the Deep: live monitoring of ocean noise and cetacean acoustic signals.

PubMed

André, M; van der Schaar, M; Zaugg, S; Houégnigan, L; Sánchez, A M; Castell, J V

2011-01-01

The development and broad use of passive acoustic monitoring techniques have the potential to help assessing the large-scale influence of artificial noise on marine organisms and ecosystems. Deep-sea observatories have the potential to play a key role in understanding these recent acoustic changes. LIDO (Listening to the Deep Ocean Environment) is an international project that is allowing the real-time long-term monitoring of marine ambient noise as well as marine mammal sounds at cabled and standalone observatories. Here, we present the overall development of the project and the use of passive acoustic monitoring (PAM) techniques to provide the scientific community with real-time data at large spatial and temporal scales. Special attention is given to the extraction and identification of high frequency cetacean echolocation signals given the relevance of detecting target species, e.g. beaked whales, in mitigation processes, e.g. during military exercises. Copyright © 2011. Published by Elsevier Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emanuela Barzi et al.

Fermilab is developing 11 T superconducting dipole magnets for future accelerators based on Nb{sub 3}Sn conductor. Within the High Field Magnet Project, the first prototypes feature 1 meter long two-layer shell-type coils and common coils. For the former, keystoned Rutherford-type cable made of 28 Nb{sub 3}Sn strands 1 mm in diameter are used, whereas for the latter a 60-strand flat cable was chosen. Multifilamentary Nb{sub 3}Sn strands produced with various technologies by industry were used for the development and testing of the prototype cable. An experimental cabling machine with up to 28-strand capacity that has been recently purchased, installed andmore » commissioned at Fermilab, has allowed further advances in strand and cable studies. Cables of 27 and 28 strands of various structures (single strands or assemblies of sub-strands), with aspect ratios from 7 to 17, packing factors from 85 to 95%, with and without a stainless steel core were made out of Copper, NbTi, and Modified Jelly Roll (OST), Powder-in-Tube (SMI) and Internal Tin (Mitsubishi) Nb{sub 3}Sn strands. optimal parameters were determined with respect to mechanical and electrical properties, including critical current degradation, interstrand resistance, etc. Round strands of the same billets used in the cables were deformed by rolling them down to various thicknesses. Their critical current Ic was then measured and compared with that of the strands extracted from cables having different packing factors. This paper summarizes the results of such R and D efforts at Fermilab.« less

The effect of postoperative passive motion on rotator cuff healing in a rat model.

PubMed

Peltz, Cathryn D; Dourte, Leann M; Kuntz, Andrew F; Sarver, Joseph J; Kim, Soung-Yon; Williams, Gerald R; Soslowsky, Louis J

2009-10-01

Surgical repairs of torn rotator cuff tendons frequently fail. Immobilization has been shown to improve tissue mechanical properties in an animal model of rotator cuff repair, and passive motion has been shown to improve joint mechanics in animal models of flexor tendon repair. Our objective was to determine if daily passive motion would improve joint mechanics in comparison with continuous immobilization in a rat rotator cuff repair model. We hypothesized that daily passive motion would result in improved passive shoulder joint mechanics in comparison with continuous immobilization initially and that there would be no differences in passive joint mechanics or insertion site mechanical properties after four weeks of remobilization. A supraspinatus injury was created and was surgically repaired in sixty-five Sprague-Dawley rats. Rats were separated into three postoperative groups (continuous immobilization, passive motion protocol 1, and passive motion protocol 2) for two weeks before all underwent a remobilization protocol for four weeks. Serial measurements of passive shoulder mechanics (internal and external range of motion and joint stiffness) were made before surgery and at two and six weeks after surgery. After the animals were killed, collagen organization and mechanical properties of the tendon-to-bone insertion site were determined. Total range of motion for both passive motion groups (49% and 45% of the pre-injury values) was less than that for the continuous immobilization group (59% of the pre-injury value) at two weeks and remained significantly less following four weeks of remobilization exercise. Joint stiffness at two weeks was increased for both passive motion groups in comparison with the continuous immobilization group. At both two and six weeks after repair, internal range of motion was significantly decreased whereas external range of motion was not. There were no differences between the groups in terms of collagen organization or mechanical properties. In this model, immediate postoperative passive motion was found to be detrimental to passive shoulder mechanics. We speculate that passive motion results in increased scar formation in the subacromial space, thereby resulting in decreased range of motion and increased joint stiffness. Passive motion had no effect on collagen organization or tendon mechanical properties measured six weeks after surgery.

Edge modulation of electronics and transport properties of cliff-edge phosphorene nanoribbons

NASA Astrophysics Data System (ADS)

Guo, Caixia; Wang, Tianxing; Xia, Congxin; Liu, Yufang

2017-12-01

Based on the first-principles calculations, we study the electronic structures and transport properties of cliff-like edge phosphorene nanoribbons (CPNRs), considering different types of edge passivation. The band structures of bare CPNRs possess the metallic features; while hydrogen (H), fluorine (F), chlorine (Cl) and oxygen (O) atoms-passivated CPNRs are semiconductor materials, and the band gap values monotonically decrease when the ribbon width increases. Moreover, the H and F-passivated CPNRs exhibit the direct band gap characteristics, while the Cl and O-passivated cases show the features of indirect band gap. In addition, the edge passivated CPNRs are more energetically stable than bare edge case. Meanwhile, our results also show that the transport properties of the CPNRs can be obviously influenced by the different edge passivation.

Probabilistic models to estimate fire-induced cable damage at nuclear power plants

NASA Astrophysics Data System (ADS)

Valbuena, Genebelin R.

Even though numerous PRAs have shown that fire can be a major contributor to nuclear power plant risk, there are some specific areas of knowledge related to this issue, such as the prediction of fire-induced damage to electrical cables and circuits, and their potential effects in the safety of the nuclear power plant, that still constitute a practical enigma, particularly for the lack of approaches/models to perform consistent and objective assessments. This report contains a discussion of three different models to estimate fire-induced cable damage likelihood given a specified fire profile: the kinetic, the heat transfer and the IR "K Factor" model. These models not only are based on statistical analysis of data available in the open literature, but to the greatest extent possible they use physics based principles to describe the underlying mechanism of failures that take place among the electrical cables upon heating due to external fires. The characterization of cable damage, and consequently the loss of functionality of electrical cables in fire is a complex phenomenon that depends on a variety of intrinsic factors such as cable materials and dimensions, and extrinsic factors such as electrical and mechanical loads on the cables, heat flux severity, and exposure time. Some of these factors are difficult to estimate even in a well-characterized fire, not only for the variability related to the unknown material composition and physical arrangements, but also for the lack of objective frameworks and theoretical models to study the behavior of polymeric wire cable insulation under dynamic external thermal insults. The results of this research will (1) help to develop a consistent framework to predict fire-induced cable failure modes likelihood, and (2) develop some guidance to evaluate and/or reduce the risk associated with these failure modes in existing and new power plant facilities. Among the models evaluated, the physics-based heat transfer model takes into account the properties and characteristics of the cables and cable materials, and the characteristics of the thermal insult. This model can be used to estimate the probability of cable damage under different thermal conditions.

Reliability of dynamometric passive properties of the pelvic floor muscles in postmenopausal women with stress urinary incontinence.

PubMed

Morin, Mélanie; Gravel, Denis; Bourbonnais, Daniel; Dumoulin, Chantale; Ouellet, Stéphane

2008-01-01

The passive properties of the pelvic floor muscles (PFM) might play a role in stress urinary incontinence (SUI) pathophysiology. To investigate the test-retest reliability of the dynamometric passive properties of the PFM in postmenopausal SUI women. Thirty-two SUI postmenopausal women were convened to two sessions 2 weeks apart. In each session, the measurements were repeated twice. The pelvic floor musculature was evaluated in four different conditions: (1) forces recorded at minimal aperture (initial passive resistance); (2) passive resistance at maximal aperture; (3) five lengthening and shortening cycles (Forces and passive elastic stiffness (PES) were evaluated at different vaginal apertures. Hysteresis was also calculated.); (4) Percentage of passive resistance loss after 1 min of sustained stretching was computed. The generalizability theory was used to calculate two reliability estimates, the dependability indices (Phi) and the standard error of measurement (SEM), for one session involving one measurement or the mean of two measurements. Overall, the reliability of the passive properties was good with indices of dependability of 0.75-0.93. The SEMs for forces and PES were 0.24-0.67 N and 0.03-0.10 N/mm, respectively, for mean, maximal and 20-mm apertures, representing an error between 13% and 23%. Passive forces at minimal aperture showed lower reliability (Phi = 0.51-0.57) compared with other vaginal openings. The aperture at a common force of 0.5 N was the only parameter demonstrating a poor reliability (Phi = 0.35). This new approach for assessing PFM passive properties showed enough reliability for highly recommending its inclusion in the PFM assessment of SUI postmenopausal women. (c) 2008 Wiley-Liss, Inc.

Asymptotic Stability of Interconnected Passive Non-Linear Systems

NASA Technical Reports Server (NTRS)

Isidori, A.; Joshi, S. M.; Kelkar, A. G.

1999-01-01

This paper addresses the problem of stabilization of a class of internally passive non-linear time-invariant dynamic systems. A class of non-linear marginally strictly passive (MSP) systems is defined, which is less restrictive than input-strictly passive systems. It is shown that the interconnection of a non-linear passive system and a non-linear MSP system is globally asymptotically stable. The result generalizes and weakens the conditions of the passivity theorem, which requires one of the systems to be input-strictly passive. In the case of linear time-invariant systems, it is shown that the MSP property is equivalent to the marginally strictly positive real (MSPR) property, which is much simpler to check.

Cable aging and condition monitoring of radiation resistant nano-dielectrics in advanced reactor applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duckworth, Robert C; Aytug, Tolga; Paranthaman, Mariappan Parans

2015-01-01

Cross-linked polyethylene (XLPE) nanocomposites have been developed in an effort to improve cable insulation lifetime to serve in both instrument cables and auxiliary power systems in advanced reactor applications as well as to provide an alternative for new or retro-fit cable insulation installations. Nano-dielectrics composed of different weight percentages of MgO & SiO 2 have been subjected to radiation at accumulated doses approaching 20 MRad and thermal aging temperatures exceeding 100 C. Depending on the composition, the performance of the nanodielectric insulation was influenced, both positively and negatively, when quantified with respect to its electrical and mechanical properties. For virginmore » unradiated or thermally aged samples, XLPE nanocomposites with 1wt.% SiO 2 showed improvement in breakdown strength and reduction in its dissipation factor when compared to pure undoped XLPE, while XLPE 3wt.% SiO 2 resulted in lower breakdown strength. When aged in air at 120 C, retention of electrical breakdown strength and dissipation factor was observed for XLPE 3wt.% MgO nanocomposites. Irrespective of the nanoparticle species, XLPE nanocomposites that were gamma irradiated up to the accumulated dose of 18 MRad showed a significant drop in breakdown strength especially for particle concentrations greater than 3 wt.%. Additional attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy measurements suggest changes in the structure of the XLPE SiO 2 nanocomposites associated with the interaction of silicon and oxygen. Discussion on the relevance of property changes with respect to cable aging and condition monitoring is presented.« less

THE PASSIVE PROPERTIES OF MUSCLE FIBERS ARE VELOCITY DEPENDENT

PubMed Central

Rehorn, Michael R.; Schroer, Alison K.; Blemker, Silvia S.

2014-01-01

The passive properties of skeletal muscle play an important role in muscle function. While the passive quasi-static elastic properties of muscle fibers have been well characterized, the dynamic visco-elastic passive behavior of fibers has garnered less attention. In particular, it is unclear how the visco-elastic properties are influenced by lengthening velocity, in particular for the range of physiologically relevant velocities. The goals of this work were to: (i) measure the effects of lengthening velocity on the peak stresses within single muscle fibers to determine how passive behavior changes over a range of physiologically relevant lengthening rates (0.1–10 Lo/s), and (ii) develop a mathematical model of fiber viscoelasticity based on these measurements. We found that passive properties depend on strain rate, in particular at the low loading rates (0.1–3 Lo/s), and that the measured behavior can be predicted across a range of loading rates and time histories with a quasi-linear viscoelastic model. In the future, these results can be used to determine the impact of viscoelastic behavior on intramuscular stresses and forces during a variety of dynamic movements. PMID:24360198

Carbon nanotube wires and cables: Near-term applications and future perspectives

NASA Astrophysics Data System (ADS)

Jarosz, Paul; Schauerman, Christopher; Alvarenga, Jack; Moses, Brian; Mastrangelo, Thomas; Raffaelle, Ryne; Ridgley, Richard; Landi, Brian

2011-11-01

Wires and cables are essential to modern society, and opportunities exist to develop new materials with reduced resistance, mass, and/or susceptibility to fatigue. This article describes how carbon nanotubes (CNTs) offer opportunities for integration into wires and cables for both power and data transmission due to their unique physical and electronic properties. Macroscopic CNT wires and ribbons are presently shown as viable replacements for metallic conductors in lab-scale demonstrations of coaxial, USB, and Ethernet cables. In certain applications, such as the outer conductor of a coaxial cable, CNT materials may be positioned to displace metals to achieve substantial benefits (e.g. reduction in cable mass per unit length (mass/length) up to 50% in some cases). Bulk CNT materials possess several unique properties which may offer advantages over metallic conductors, such as flexure tolerance and environmental stability. Specifically, CNT wires were observed to withstand greater than 200,000 bending cycles without increasing resistivity. Additionally, CNT wires exhibit no increase in resistivity after 80 days in a corrosive environment (1 M HCl), and little change in resistivity with temperature (<1% from 170-330 K). This performance is superior to conventional metal wires and truly novel for a wiring material. However, for CNTs to serve as a full replacement for metals, the electrical conductivity of CNT materials must be improved. Recently, the conductivity of a CNT wire prepared through simultaneous densification and doping has exceeded 1.3 × 106 S/m. This level of conductivity brings CNTs closer to copper (5.8 × 107 S/m) and competitive with some metals (e.g. gold) on a mass-normalized basis. Developments in manipulation of CNT materials (e.g. type enrichment, doping, alignment, and densification) have shown progress towards this goal. In parallel with efforts to improve bulk conductivity, integration of CNT materials into cabling architectures will require development in electrical contacting. Several methods for contacting bulk CNT materials to metals are demonstrated, including mechanical crimping and ultrasonic bonding, along with a method for reducing contact resistance by tailoring the CNT-metal interface via electroless plating. Collectively, these results summarize recent progress in CNT wiring technologies and illustrate that nanoscale conductors may become a disruptive technology in cabling designs.

Carbon nanotube wires and cables: near-term applications and future perspectives.

PubMed

Jarosz, Paul; Schauerman, Christopher; Alvarenga, Jack; Moses, Brian; Mastrangelo, Thomas; Raffaelle, Ryne; Ridgley, Richard; Landi, Brian

2011-11-01

Wires and cables are essential to modern society, and opportunities exist to develop new materials with reduced resistance, mass, and/or susceptibility to fatigue. This article describes how carbon nanotubes (CNTs) offer opportunities for integration into wires and cables for both power and data transmission due to their unique physical and electronic properties. Macroscopic CNT wires and ribbons are presently shown as viable replacements for metallic conductors in lab-scale demonstrations of coaxial, USB, and Ethernet cables. In certain applications, such as the outer conductor of a coaxial cable, CNT materials may be positioned to displace metals to achieve substantial benefits (e.g. reduction in cable mass per unit length (mass/length) up to 50% in some cases). Bulk CNT materials possess several unique properties which may offer advantages over metallic conductors, such as flexure tolerance and environmental stability. Specifically, CNT wires were observed to withstand greater than 200,000 bending cycles without increasing resistivity. Additionally, CNT wires exhibit no increase in resistivity after 80 days in a corrosive environment (1 M HCl), and little change in resistivity with temperature (<1% from 170-330 K). This performance is superior to conventional metal wires and truly novel for a wiring material. However, for CNTs to serve as a full replacement for metals, the electrical conductivity of CNT materials must be improved. Recently, the conductivity of a CNT wire prepared through simultaneous densification and doping has exceeded 1.3 × 10(6) S/m. This level of conductivity brings CNTs closer to copper (5.8 × 10(7) S/m) and competitive with some metals (e.g. gold) on a mass-normalized basis. Developments in manipulation of CNT materials (e.g. type enrichment, doping, alignment, and densification) have shown progress towards this goal. In parallel with efforts to improve bulk conductivity, integration of CNT materials into cabling architectures will require development in electrical contacting. Several methods for contacting bulk CNT materials to metals are demonstrated, including mechanical crimping and ultrasonic bonding, along with a method for reducing contact resistance by tailoring the CNT-metal interface via electroless plating. Collectively, these results summarize recent progress in CNT wiring technologies and illustrate that nanoscale conductors may become a disruptive technology in cabling designs.

Development and Evaluation of Phosphonitrilic Fluoroelastomer O-Rings.

DTIC Science & Technology

1975-04-01

and having the following formula: c 0CH2(CF2$CF2H n 1 The polymer contained svfflclent cure sites to attain good curability with mnvent~onai...cable with phosphonitrilic fluoroelastomer compounds. A good quality coating of approximately 0,031" thickness was obtained by passing the cable through...extreme low temperature flexibility, outstanding fluid resistance, good heat resis- tance and good dynnmic properties. O-ring seals are one such

Effects of various Mg/Si ratios on microstructure and performance property of Al-Mg-Si alloy cables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Xuexuan

2016-09-15

High quality AA6101 aluminum cables are critical to electrical industry to meet the energy consumption requests. In the present work, the influence of Mg/Si ratios on the electrical conductivity and mechanical properties of AA6101 aluminum alloy was investigated. Wheatstone Bridge method and tensile test were employed to characterize the mechanical properties. X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were used to understand the morphology of the precipitation and the mechanism of age hardening. It is found that excessive Si benefits high strength and high conductivity while excessive Mg plays a negative role in the strengthmore » and the conductivity of AA6101 cables. Excessive Si elements promote both the precipitating rate and quantity of β″ phase therefore increase the tensile strength. Excessive Si elements also help with decreasing the lattice distortion, which contributes to the enhancement of the conductivity. Excessive Mg elements lead to more dissolved Mg after aging treatment, therefore increase lattice distortion of the matrix and promote the deposit of coarse Mg-enriched secondary phase. - Highlights: •A new available method to improve the mechanical and electrical properties of Al-Mg-Si alloy •Investigation on the role of various Mg/Si ratios in the changes of comprehensive performances •Discussions on the morphology of the precipitation phases and the mechanism of hardening.« less

Evaluation of DC electric field distribution of PPLP specimen based on the measurement of electrical conductivity in LN2

NASA Astrophysics Data System (ADS)

Hwang, Jae-Sang; Seong, Jae-Kyu; Shin, Woo-Ju; Lee, Jong-Geon; Cho, Jeon-Wook; Ryoo, Hee-Suk; Lee, Bang-Wook

2013-11-01

High temperature superconducting (HTS) cable has been paid much attention due to its high efficiency and high current transportation capability, and it is also regarded as eco-friendly power cable for the next generation. Especially for DC HTS cable, it has more sustainable and stable properties compared to AC HTS cable due to the absence of AC loss in DC HTS cable. Recently, DC HTS cable has been investigated competitively all over the world, and one of the key components of DC HTS cable to be developed is a cable joint box considering HVDC environment. In order to achieve the optimum insulation design of the joint box, analysis of DC electric field distribution of the joint box is a fundamental process to develop DC HTS cable. Generally, AC electric field distribution depends on relative permittivity of dielectric materials but in case of DC, electrical conductivity of dielectric material is a dominant factor which determines electric field distribution. In this study, in order to evaluate DC electric field characteristics of the joint box for DC HTS cable, polypropylene laminated paper (PPLP) specimen has been prepared and its DC electric field distribution was analyzed based on the measurement of electrical conductivity of PPLP in liquid nitrogen (LN2). Electrical conductivity of PPLP in LN2 has not been reported yet but it should be measured for DC electric field analysis. The experimental works for measuring electrical conductivity of PPLP in LN2 were presented in this paper. Based on the experimental works, DC electric field distribution of PPLP specimen was fully analyzed considering the steady state and the transient state of DC. Consequently, it was possible to determine the electric field distribution characteristics considering different DC applying stages including DC switching on, DC switching off and polarity reversal conditions.

LONG TERM OPERATION ISSUES FOR ELECTRICAL CABLE SYSTEMS IN NUCLEAR POWER PLANTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fifield, Dr Leonard S; Duckworth, Robert C; Glass III, Dr. Samuel W.

Nuclear power plants contain hundreds of kilometers of electrical cables including cables used for power, for instrumentation, and for control. It is essential that safety-related cable systems continue to perform following a design-basis event. Wholesale replacement of electrical cables in existing plants facing licensing period renewal is both impractical and cost-prohibitive. It is therefore important to understand the long term aging of cable materials to have confidence that aged cables will perform when needed. It is equally important in support of cable aging management to develop methods to evaluate the health of installed cables and inform selective cable replacement decisions.more » The most common insulation materials for electrical cables in nuclear power plants are cross-linked polyethylene and ethylene-propylene rubber. The mechanical properties of these materials degrade over time in the presence of environmental stresses including heat, gamma irradiation, and moisture. Mechanical degradation of cable insulation beyond a certain threshold is unacceptable because it can lead to insulation cracking, exposure of energized conductors, arcing and burning or loss of the ability of the cable system to function during a design-basis accident. While thermal-, radiation-, and moisture-related degradation of polymer insulation materials has been extensively studied over the last few decades, questions remain regarding the long-term performance of cable materials in nuclear plant-specific environments. Identified knowledge gaps include an understanding of the temperature-dependence of activation energies for thermal damage and an understanding of the synergistic effects of radiation and thermal stress on polymer degradation. Many of the outstanding questions in the aging behavior of cable materials relate to the necessity of predicting long-term field degradation using accelerated aging results from the laboratory. Materials degrade faster under more extreme conditions, but extension of behavior to long term degradation under more mild conditions, such as those experienced by most installed cables in nuclear power plants, is complicated by the fact that different degradation mechanisms may be involved in extreme and mild scenarios. The discrepancy in predicted results from short term, more extreme exposure and actual results from longer term, more mild exposures can be counter intuitive. For instance, due to the attenuation of oxidation penetration in material samples rapidly aged through exposure to high temperatures, the bulk of the samples may be artificially protected from thermal aging. In another example, simultaneous exposure of cable insulation material to heat and radiation may actually lead to less damage at higher temperatures than may be observed at lower temperatures. The Light Water Reactor Sustainability program of the United States (US) Department of Energy Office (DOE) of Nuclear Energy is funding research to increase the predictive understanding of electrical cable material aging and degradation in existing nuclear power plants in support of continued safe operation of plants beyond their initial license periods. This research includes the evaluation and development of methods to assess installed cable condition.« less

Dose rate effects in radiation degradation of polymer-based cable materials

NASA Astrophysics Data System (ADS)

Plaček, V.; Bartoníček, B.; Hnát, V.; Otáhal, B.

2003-08-01

Cable ageing under the nuclear power plant (NPP) conditions must be effectively managed to ensure that the required plant safety and reliability are maintained throughout the plant service life. Ionizing radiation is one of the main stressors causing age-related degradation of polymer-based cable materials in air. For a given absorbed dose, radiation-induced damage to a polymer in air environment usually depends on the dose rate of the exposure. In this work, the effect of dose rate on the degradation rate has been studied. Three types of NPP cables (with jacket/insulation combinations PVC/PVC, PVC/PE, XPE/XPE) were irradiated at room temperature using 60Co gamma ray source at average dose rates of 7, 30 and 100 Gy/h with the doses up to 590 kGy. The irradiated samples have been tested for their mechanical properties, thermo-oxidative stability (using differential scanning calorimetry, DSC), and density. In the case of PVC and PE samples, the tested properties have shown evident dose rate effects, while the XPE material has shown no noticeable ones. The values of elongation at break and the thermo-oxidative stability decrease with the advanced degradation, density tends to increase with the absorbed dose. For XPE samples this effect can be partially explained by the increase of crystallinity. It was tested by the DSC determination of the crystalline phase amount.

77 FR 12906 - Notice of Release From Federal Grant Assurance Obligations at Fresno Yosemite International...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-02

... continue to use the land as passive wetlands, which will keep the property vacant and compatible with the... generating potential. The planned land use is for water recharge, ponding basin, and passive wetlands. The property will be kept mitigated to ensure that its passive use does not interfere with airport operations...

Development of aluminum-stabilized superconducting cables for the Mu2e detector solenoid

DOE PAGES

Lombardo, Vito; Buehler, M.; Lamm, M.; ...

2016-06-01

Here, the Mu2e experiment at Fermilab is designed to measure the rare process of direct muon-to-electron conversion in the field of a nucleus. The experiment comprises a system of three superconducting solenoids, which focus secondary muons from the production target and transport them to an aluminum stopping target, while minimizing the associated background. The Detector Solenoid (DS) is the last magnet in the transport line and its main functions are to provide a graded field in the region of the stopping target as well as a precision magnetic field in a volume large enough to house the tracker downstream ofmore » the stopping target. The Detector Solenoid coils are designed to be wound using NbTi Rutherford cables conformed in high purity aluminum for stabilization and then cold-worked for strength. Two types of Al-stabilized conductor are required to build the DS coils, one for the gradient section and one for the spectrometer section of the solenoid. The dimensions are optimized to generate the required field profile when the same current is transported in both conductors. The conductors contain NbTi Rutherford cables with 12 (DS1) and 8 (DS2) strands respectively and are manufactured by two different vendors. This paper describes the results of the manufacturing of production lengths of the Al-stabilized cables needed to build the Mu2e Detector Solenoid as well as the testing campaigns and main results. The main cable properties and results of electrical and mechanical tests are summarized and discussed for each stage of the cable development process. Results are compared to design values to show how the production cables satisfy all the design criteria starting from the NbTi wires to the Al-stabilized cables.« less

Structural design and static analysis of a double-ring deployable truss for mesh antennas

NASA Astrophysics Data System (ADS)

Xu, Yan; Guan, Fuling; Chen, Jianjun; Zheng, Yao

2012-12-01

This paper addresses the structural design, the deployment control design, the static analysis and the model testing of a new double-ring deployable truss that is intended for large mesh antennas. This deployable truss is a multi-DOF (degree-of-freedom), over-constrained mechanism. Two kinds of deployable basic elements were introduced, as well as a process to synthesise the structure of the deployable truss. The geometric equations were formulated to determine the length of each strut, including the effects of the joint size. A DOF evaluation showed that the mechanism requires two active cables and requires deployment control. An open-loop control system was designed to control the rotational velocities of two motors. The structural stiffness of the truss was assessed by static analysis that considered the effects of the constraint condition and the pre-stress of the passive cables. A 4.2-metre demonstration model of an antenna was designed and fabricated. The geometry and the deployment behaviour of the double-ring truss were validated by the experiments using this model.

Captivating Broad Audiences with an Internet-connected Ocean

NASA Astrophysics Data System (ADS)

Moran, K.; Elliott, L.; Gervais, F.; Juniper, K.; Owens, D.; Pirenne, B.

2012-12-01

NEPTUNE Canada, a network of Ocean Networks Canada and the first deep water cabled ocean observatory, began operations in December 2009. Located offshore Canada's west coast, the network streams data from passive, active, and interactive sensors positioned at five nodes along its 800 km long looped cable to the Internet. This technically advanced system includes a sophisticated data management and archiving system, which enables the collection of real-time physical, chemical, geological, and biological oceanographic data, including video, at resolutions relevant for furthering our understanding of the dynamics of the earth-ocean system. Scientists in Canada and around the world comprise the primary audience for these data, but NEPTUNE Canada is also serving these data to broader audiences including K-16 students and teachers, informal educators, citizen scientists, the press, and the public. Here we present our engagement tools, approaches, and experiences including electronic books, personal phone apps, Internet-served video, social media, mini-observatory systems, print media, live broadcasting from sea, and a citizen scientist portal.NEPTUNE Canada's ibook available on Apple's iBook store.

Structure-property relationships in an Al matrix Ca nanofilamentary composite conductor with potential application in high-voltage power transmission

NASA Astrophysics Data System (ADS)

Tian, Liang

This study investigated the processing-structure-properties relationships in an Al/Ca composites using both experiments and modeling/simulation. A particular focus of the project was understanding how the strength and electrical conductivity of the composite are related to its microstructure in the hope that a conducting material with light weight, high strength, and high electrical conductivity can be developed to produce overhead high-voltage power transmission cables. The current power transmission cables (e.g., Aluminum Conductor Steel Reinforced (ACSR)) have acceptable performance for high-voltage AC transmission, but are less well suited for high-voltage DC transmission due to the poorly conducting core materials that support the cable weight. This Al/Ca composite was produced by powder metallurgy and severe plastic deformation by extrusion and swaging. The fine Ca metal powders have been produced by centrifugal atomization with rotating liquid oil quench bath, and a detailed study about the atomization process and powder characteristics has been conducted. The microstructure of Al/Ca composite was characterized by electron microscopy. Microstructure changes at elevated temperature were characterized by thermal analysis and indirect resistivity tests. The strength and electrical conductivity were measured by tensile tests and four-point probe resistivity tests. Predicting the strength and electrical conductivity of the composite was done by micro-mechanics-based analytical modeling. Microstructure evolution was studied by mesoscale-thermodynamics-based phase field modeling and a preliminary atomistic molecular dynamics simulation. The application prospects of this composite was studied by an economic analysis. This study suggests that the Al/Ca (20 vol. %) composite shows promise for use as overhead power transmission cables. Further studies are needed to measure the corrosion resistance, fatigue properties and energized field performance of this composite.

Model identification and vision-based H∞ position control of 6-DoF cable-driven parallel robots

NASA Astrophysics Data System (ADS)

Chellal, R.; Cuvillon, L.; Laroche, E.

2017-04-01

This paper presents methodologies for the identification and control of 6-degrees of freedom (6-DoF) cable-driven parallel robots (CDPRs). First a two-step identification methodology is proposed to accurately estimate the kinematic parameters independently and prior to the dynamic parameters of a physics-based model of CDPRs. Second, an original control scheme is developed, including a vision-based position controller tuned with the H∞ methodology and a cable tension distribution algorithm. The position is controlled in the operational space, making use of the end-effector pose measured by a motion-tracking system. A four-block H∞ design scheme with adjusted weighting filters ensures good trajectory tracking and disturbance rejection properties for the CDPR system, which is a nonlinear-coupled MIMO system with constrained states. The tension management algorithm generates control signals that maintain the cables under feasible tensions. The paper makes an extensive review of the available methods and presents an extension of one of them. The presented methodologies are evaluated by simulations and experimentally on a redundant 6-DoF INCA 6D CDPR with eight cables, equipped with a motion-tracking system.

Comparison of cable ageing

NASA Astrophysics Data System (ADS)

Plaček, Vít; Kohout, Tomáš

2010-03-01

Two cable types, which currently are used in nuclear power plants (NPP) and which are composed by jacket/insulation materials, i.e. PVC/PVC and PVC/PE, were exposed to accelerated ageing conditions, in order to simulate their behavior after 10 years in service. The cables were aged under two different test conditions: With relatively high accelerating ageing speed:Radiation ageing was carried out at room temperature at a dose rate of 2900 Gy/h, followed by thermal ageing at 100 °C. This accelerated ageing condition was fairly fast, but still in compliance with the standards. With moderate ageing speed:The radiation and thermal ageing was performed simultaneously (superimposed) at a dose rate of 2.7-3.7Gy/h and a temperature of 68-70 °C. Such a test condition seems to be very close to the radiation and temperature impact onto the cables in the real NPP service. Finally, mechanical properties were measured to characterize the ageing status of the cables. The purpose of this study was to compare degradation effects, derived from both ageing methods, and to demonstrate that results obtained from high values of accelerating parameters and from fast ageing simulation can be very different from reality. The observed results corroborated this assumption.

Unusual Attenuation Recovery Process After Fiber Optic Cable Irradiation

NASA Astrophysics Data System (ADS)

Konečná, Z.; Plaček, V.; Havránek, P.

2017-11-01

At present, the number of optical cables in nuclear power plants has been increasing. Fiber optic cables are commonly used at nuclear power plants in instrumentation and control systems but they are usually used in environments without radiation. Nevertheless, currently, the number of applications in NPP containment with radiation is increasing. One of the most prevalent effects of radiation exposure is an increase of signal attenuation (signal loss). This is the result of fiber darkening due to radiation exposure and it is the main limitation factor in application of fiber optics in radiation environment. However, after the irradiation, the fiber optics go through a “recovery process” during which the optical properties improve again; i.e. attenuation decreases. However, we have found cable, where the expected healing process after few days changed its trend and the attenuation increased again to a value well above the attenuation just after the irradiation. This paper describes experiments that were carried out to explain this unusual recovery behaviour.

A Prestressed Cable Network Model of the Adherent Cell Cytoskeleton

PubMed Central

Coughlin, Mark F.; Stamenović, Dimitrije

2003-01-01

A prestressed cable network is used to model the deformability of the adherent cell actin cytoskeleton. The overall and microstructural model geometries and cable mechanical properties were assigned values based on observations from living cells and mechanical measurements on isolated actin filaments, respectively. The models were deformed to mimic cell poking (CP), magnetic twisting cytometry (MTC) and magnetic bead microrheometry (MBM) measurements on living adherent cells. The models qualitatively and quantitatively captured the fibroblast cell response to the deformation imposed by CP while exhibiting only some qualitative features of the cell response to MTC and MBM. The model for CP revealed that the tensed peripheral actin filaments provide the key resistance to indentation. The actin filament tension that provides mechanical integrity to the network was estimated at ∼158 pN, and the nonlinear mechanical response during CP originates from filament kinematics. The MTC and MBM simulations revealed that the model is incomplete, however, these simulations show cable tension as a key determinant of the model response. PMID:12547813

Asymmetric distribution of Echinoid defines the epidermal leading edge during Drosophila dorsal closure

PubMed Central

Laplante, Caroline

2011-01-01

During Drosophila melanogaster dorsal closure, lateral sheets of embryonic epidermis assemble an actomyosin cable at their leading edge and migrate dorsally over the amnioserosa, converging at the dorsal midline. We show that disappearance of the homophilic cell adhesion molecule Echinoid (Ed) from the amnioserosa just before dorsal closure eliminates homophilic interactions with the adjacent dorsal-most epidermal (DME) cells, which comprise the leading edge. The resulting planar polarized distribution of Ed in the DME cells is essential for the localized accumulation of actin regulators and for actomyosin cable formation at the leading edge and for the polarized localization of the scaffolding protein Bazooka/PAR-3. DME cells with uniform Ed fail to assemble a cable and protrude dorsally, suggesting that the cable restricts dorsal migration. The planar polarized distribution of Ed in the DME cells thus provides a spatial cue that polarizes the DME cell actin cytoskeleton, defining the epidermal leading edge and establishing its contractile properties. PMID:21263031

A prestressed cable network model of the adherent cell cytoskeleton.

PubMed

Coughlin, Mark F; Stamenović, Dimitrije

2003-02-01

A prestressed cable network is used to model the deformability of the adherent cell actin cytoskeleton. The overall and microstructural model geometries and cable mechanical properties were assigned values based on observations from living cells and mechanical measurements on isolated actin filaments, respectively. The models were deformed to mimic cell poking (CP), magnetic twisting cytometry (MTC) and magnetic bead microrheometry (MBM) measurements on living adherent cells. The models qualitatively and quantitatively captured the fibroblast cell response to the deformation imposed by CP while exhibiting only some qualitative features of the cell response to MTC and MBM. The model for CP revealed that the tensed peripheral actin filaments provide the key resistance to indentation. The actin filament tension that provides mechanical integrity to the network was estimated at approximately 158 pN, and the nonlinear mechanical response during CP originates from filament kinematics. The MTC and MBM simulations revealed that the model is incomplete, however, these simulations show cable tension as a key determinant of the model response.

Modeling of Electrical Cable Failure in a Dynamic Assessment of Fire Risk

NASA Astrophysics Data System (ADS)

Bucknor, Matthew D.

Fires at a nuclear power plant are a safety concern because of their potential to defeat the redundant safety features that provide a high level of assurance of the ability to safely shutdown the plant. One of the added complexities of providing protection against fires is the need to determine the likelihood of electrical cable failure which can lead to the loss of the ability to control or spurious actuation of equipment that is required for safe shutdown. A number of plants are now transitioning from their deterministic fire protection programs to a risk-informed, performance based fire protection program according to the requirements of National Fire Protection Association (NFPA) 805. Within a risk-informed framework, credit can be taken for the analysis of fire progression within a fire zone that was not permissible within the deterministic framework of a 10 CFR 50.48 Appendix R safe shutdown analysis. To perform the analyses required for the transition, plants need to be able to demonstrate with some level of assurance that cables related to safe shutdown equipment will not be compromised during postulated fire scenarios. This research contains the development of new cable failure models that have the potential to more accurately predict electrical cable failure in common cable bundle configurations. Methods to determine the thermal properties of the new models from empirical data are presented along with comparisons between the new models and existing techniques used in the nuclear industry today. A Dynamic Event Tree (DET) methodology is also presented which allows for the proper treatment of uncertainties associated with fire brigade intervention and its effects on cable failure analysis. Finally a shielding analysis is performed to determine the effects on the temperature response of a cable bundle that is shielded from a fire source by an intervening object such as another cable tray. The results from the analyses demonstrate that models of similar complexity to existing cable failure techniques and tuned to empirical data can better approximate the temperature response of a cables located in tightly packed cable bundles. The new models also provide a way to determine the conditions insides a cable bundle which allows for separate treatment of cables on the interior of the bundle from cables on the exterior of the bundle. The results from the DET analysis show that the overall assessed probability of cable failure can be significantly reduced by more realistically accounting for the influence that the fire brigade has on a fire progression scenario. The shielding analysis results demonstrate a significant reduction in the temperature response of a shielded versus a non-shielded cable bundle; however the computational cost of using a fire progression model that can capture these effects may be prohibitive for performing DET analyses with currently available computational fluid dynamics models and computational resources.

26 CFR 1.469-11 - Effective date and transition rules.

Code of Federal Regulations, 2010 CFR

2010-04-01

... passive activity for any taxable year of the taxpayer beginning before January 1, 1988. (ii) Property... apply the rules in § 1.469-7 in computing the taxpayer's passive activity loss and passive activity... compute the taxpayer's passive activity loss and passive activity credit. Items from nonlending...

SisterTalk: final results of a culturally tailored cable television delivered weight control program for Black women.

PubMed

Risica, Patricia Markham; Gans, Kim M; Kumanyika, Shiriki; Kirtania, Usree; Lasater, Thomas M

2013-12-27

Obesity among Black women continues to exceed that of other women. Most weight loss programs created without reference to specific cultural contexts are less effective for Black than White women. Weight control approaches accessible to Black women and adapted to relevant cultural contexts are important for addressing this problem. This paper reports the final results of SisterTalk, the randomized controlled trial of a cable TV weight control program oriented toward Black women. A five group design included a comparison group and a 2 × 2 factorial comparison of a) interactive vs. passive programming and b) telephone social support vs no telephone support, with 12 weekly initial cable TV programs followed by 4 monthly booster videos. At baseline, 3, 8, and 12 months post randomization, telephone and in person surveys were administered on diet, physical activity, and physical measurements of height and weight were taken to calculate body mass index (BMI). Analysis of variance (ANOVA) was used to examine differences over time, and between treatment and comparison groups. Dose variables reflecting use of the TV/video and written materials were also assessed. At 3 months, BMI, weight, and dietary fat were significantly lower and physical activity significantly higher among women exposed to the Cable TV intervention compared to the wait-list comparison group. Significant dietary fat differences were still observed at 8 and 12 month evaluations, but not BMI or physical activity differences. Main effects were not observed for interactive programming or enhanced social support at any time point. Within the intervention group, higher watching of the TV series and higher reading of educational materials were both (separately) associated with significantly lower dietary fat. Cable TV was an effective delivery channel to assist Black women with weight control, increasing physical activity and decreasing dietary fat during an initial intervention period, but only dietary changes persisted Enhanced social support and the ability to interact with others during the show were not effective complementary intervention components as conducted in this trial. Future research to strengthen the ability of this approach to achieve long term effects may offer even more promising outcomes.

The Thermal Regime Around Buried Submarine High-Voltage Cables

NASA Astrophysics Data System (ADS)

Emeana, C. J.; Dix, J.; Henstock, T.; Gernon, T.; Thompson, C.; Pilgrim, J.

2015-12-01

The expansion of offshore renewable energy infrastructure and the desire for "trans-continental shelf" power transmission, all require the use of submarine High Voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70oC and are typically buried at depths of 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the thermal properties of near surface shelf sediments are poorly understood and this increases the uncertainty in determining the required cable current ratings, cable reliability and the potential effects on the sedimentary environments. We present temperature measurements from a 2D laboratory experiment, designed to represent a buried, submarine HV cable. We used a large (2.5 m-high) tank, filled with water-saturated ballotini and instrumented with 120 thermocouples, which measured the time-dependent 2D temperature distributions around the heat source. The experiments use a buried heat source to represent a series of realistic cable surface temperatures with the aim for identifying the thermal regimes generated within typical non-cohesive shelf sediments: coarse silt, fine sand and very coarse sand. The steady state heat flow regimes, and normalised and radial temperature distributions were assessed. Our results show that at temperatures up to 60°C above ambient, the thermal regimes are conductive for the coarse silt sediments and convective for the very coarse sand sediments even at 7°C above ambient. However, the heat flow pattern through the fine sand sediment shows a transition from conductive to convective heat flow at a temperature of approximately 20°C above ambient. These findings offer an important new understanding of the thermal regimes associated with submarine HV cables buried in different substrates and has huge impacts on cable ratings as the IEC 60287 standard only considers conductive heat flow as well as other potential near surface impacts.

Properties and durability of the passive films on a nickel-chromium-molybdenum alloy and an iron-based bulk metallic glass

NASA Astrophysics Data System (ADS)

Pharkya, Pallavi

Alloy 22, a Ni-Cr-Mo-W alloy, and SAM1651, an Fe-Cr-Mo-B-Y-C bulk metallic glass are highly corrosion-resistant alloys. The high corrosion resistance of these alloys is due to the formation of tenacious oxide films on their surfaces. This study examines the reformation behavior of the passive films as a function of the corrosion resistance of the alloys and the corrosivity of the environment. The main tasks of this study were (i) to determine the chemical durability of passive films on these highly corrosion-resistant alloys in aggressive environments, (ii) to investigate the durability after mechanically damaging the passive films either locally or over the entire surface area and to study the reformation kinetics, (iii) to compare the durability of the passive films of the aforementioned highly corrosion resistant alloys with an alloy of intermediate corrosion resistance, AL6XN, and an alloy of less corrosion resistance, 316L SS, (iv) to examine the evolution of the electronic properties of the passive films on alloy 22 and SAM1651 under different environmental conditions such as concentrated chloride solution, acidic solution, temperature, potential and oxyanions, and (v) to develop an understanding of the relationship between the passive films' composition, electronic and electrochemical properties and the performance. A combination of techniques was utilized to meet the above mentioned objectives. Cyclic potentiodynamic polarization (CPP) was used to determine the electrochemical parameters such as freely corroding, breakdown and repassivation potentials. Electrochemical impedance spectroscopy (EIS) was used to determine the electronic properties such as impedance, thickness and capacitance of the passive films. Mott-Schottky (M-S) analysis was used to determine the type and the density of the defects in the passive films. The mechanical durability and reformation kinetics of the passive films was investigated using a scratch-repassivation method. The quality and the protectiveness of the reformed passive films after scribing were examined using EIS, M-S analysis, and AES. The results show that the passive films on alloy 22 and SAM1651 possess high chemical and mechanical durability. The reformed passive films acquired the same electronic and elemental properties as the passive films which were undamaged. The passive films on SAM1651 and alloy 22 showed better corrosion resistance and durability than did the passive films on AL6XN and 316L SS. The results also showed that the passive film behavior depends on the inherent corrosion resistance of an alloy and the corrosivity of the environment. The inherent corrosion resistance depends on the concentration of the passivity-providing elements such as Cr and Mo in the bulk composition of the alloy (and passive film), and the corrosivity of the environment which is influenced by chloride concentration, oxyanions, temperature, pH, and oxidizing potential.

Recycling of polymeric fraction of cable waste by rotational moulding.

PubMed

Díaz, Sara; Ortega, Zaida; McCourt, Mark; Kearns, Mark P; Benítez, Antonio N

2018-06-01

This study focuses on the mechanical recycling of polymeric waste that is produced in considerable amount from the cable industry. Every year large amounts of cables become waste; wires recycling has traditionally focused on metal recovery, while the polymer cover has just been considered as a residue, being landfilled or incinerated. Nowadays, increasingly restrictive regulations and concern about environment make necessary to reduce landfilling as much as possible. Main novelty of the study is that the material used in the research is a post-consumer material and the entire residual material is used, without a previous purification, in contrast with similar studies. Characterization of this residue was performed by thermal analysis, showing that the material is mainly made up of a heavy fraction (84% of the residue), which is not able to melt, fact what makes recycling more difficult. Once characterized, the material was ground, blended with virgin polyethylene and reprocessed by rotational moulding. The influence of the amount of residue and parts structure (1, 2 and 3 layers) was assessed, studying the mechanical behaviour of obtained parts (tensile, flexural and impact properties). It has been found that although mechanical properties get reduced with the increased amount of residue, up to a 35% of residue can be used without an important decrease in mechanical properties. On the other hand, the use of multiple layers in the mouldings allowed obtaining a better external appearance without compromising the mechanical properties. Copyright © 2018 Elsevier Ltd. All rights reserved.

High Voltage Hybrid Electric Propulsion - Multilayered Functional Insulation System (MFIS) NASA-GRC

NASA Technical Reports Server (NTRS)

Lizcano, M.

2017-01-01

High power transmission cables pose a key challenge in future Hybrid Electric Propulsion Aircraft. The challenge arises in developing safe transmission lines that can withstand the unique environment found in aircraft while providing megawatts of power. High voltage AC, variable frequency cables do not currently exist and present particular electrical insulation challenges since electrical arcing and high heating are more prevalent at higher voltages and frequencies. Identifying and developing materials that maintain their dielectric properties at high voltage and frequencies is crucial.

Benchmark Accelerated Aging of Harvested Hypalon/Epr and Cspe/Xlpe Power and I&C Cable in Nuclear Power Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duckworth, Robert C.; Frame, Emily; Fifield, Leonard S.

As part of the Light Water Reactor and Sustainability (LWRS) program in the U.S. Department of Energy (DOE) Office of Nuclear Energy, material aging and degradation research is currently geared to support the long-term operation of existing nuclear power plants (NPPs) as they move beyond their initial 40 year licenses. The goal of this research is to provide information so that NPPs can develop aging management programs (AMPs) to address replacement and monitoring needs as they look to operate for 20 years, and in some cases 40 years, beyond their initial operating lifetimes. For cable insulation and jacket materials thatmore » support instrument, control, and safety systems, accelerated aging data are needed to determine priorities in cable aging management programs. Before accelerated thermal and radiation aging of harvested, representative cable insulation and jacket materials, the benchmark performance of a new test capability at Oak Ridge National Laboratory (ORNL) was evaluated for temperatures between 70 and 135°C, dose rates between 100 and 500 Gy/h, and accumulated doses up to 20 kGy, Samples that were characterized and are representative of current materials in use were harvested from the Callaway NPP near Fulton, Missouri, and the San Onofre NPP north of San Diego, California. From the Callaway NPP, a multiconductor control rod cable manufactured by Boston Insulated Wire (BIW), with a Hypalon/ chorolosulfonated polyethylene (CSPE) jacket and ethylene-propylene rubber (EPR) insulation, was harvested from the auxiliary space during a planned outage in 2013. This cable was placed into service when the plant was started in 1984. From the San Onofre NPP, a Rockbestos Firewall III (FRIII) cable with a Hypalon/ CSPE jacket with cross-linked polyethylene (XLPE) insulation was harvested from an on-site, climate-controlled storage area. This conductor, which was never placed into service, was procured around 2007 in anticipation of future operation that did not occur. Benchmark aging for both jacket and insulation material was carried out in air at a temperature of 125°C or in uniform 140 Gy/h gamma irradiation over a period of 60 days. Their mechanical properties over the course of their exposures were compared with reference data from comparable cable jacket/insulation compositions and aging conditions. For both accelerated thermal and radiation aging, it was observed that the mechanical properties for the Callaway BIW control rod cable were consistent with those previously measured. However, for the San Onofre Rockbestos FRIII, there was an observable functional difference for accelerated thermal aging at 125°C. Details on possible sources for this difference and plans for resolving each source are given in this paper.« less

BENCHMARK ACCELERATED AGING OF HARVESTED HYPALON/EPR AND CSPE/XLPE POWER AND I&C CABLE IN NUCLEAR POWER PLANTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duckworth, Robert C; Fifield, Dr Leonard S

As part of the Light Water Reactor and Sustainability (LWRS) program in the U.S. Department of Energy (DOE) Office of Nuclear Energy, material aging and degradation research is currently geared to support the long-term operation of existing nuclear power plants (NPPs) as they move beyond their initial 40 year licenses. The goal of this research is to provide information so that NPPs can develop aging management programs (AMPs) to address replacement and monitoring needs as they look to operate for 20 years, and in some cases 40 years, beyond their initial operating lifetimes. For cable insulation and jacket materials thatmore » support instrument, control, and safety systems, accelerated aging data are needed to determine priorities in cable aging management programs. Before accelerated thermal and radiation aging of harvested, representative cable insulation and jacket materials, the benchmark performance of a new test capability at Oak Ridge National Laboratory (ORNL) was evaluated for temperatures between 70 and 135 C, dose rates between 100 and 500 Gy/h, and accumulated doses up to 20 kGy, Samples that were characterized and are representative of current materials in use were harvested from the Callaway NPP near Fulton, Missouri, and the San Onofre NPP north of San Diego, California. From the Callaway NPP, a multiconductor control rod cable manufactured by Boston Insulated Wire (BIW), with a Hypalon/ chorolosulfonated polyethylene (CSPE) jacket and ethylene-propylene rubber (EPR) insulation, was harvested from the auxiliary space during a planned outage in 2013. This cable was placed into service when the plant was started in 1984. From the San Onofre NPP, a Rockbestos Firewall III (FRIII) cable with a Hypalon/ CSPE jacket with cross-linked polyethylene (XLPE) insulation was harvested from an on-site, climate-controlled storage area. This conductor, which was never placed into service, was procured around 2007 in anticipation of future operation that did not occur. Benchmark aging for both jacket and insulation material was carried out in air at a temperature of 125 C or in uniform 140 Gy/h gamma irradiation over a period of 60 days. Their mechanical properties over the course of their exposures were compared with reference data from comparable cable jacket/insulation compositions and aging conditions. For both accelerated thermal and radiation aging, it was observed that the mechanical properties for the Callaway BIW control rod cable were consistent with those previously measured. However, for the San Onofre Rockbestos FRIII, there was an observable functional difference for accelerated thermal aging at 125 C. Details on possible sources for this difference and plans for resolving each source are given in this paper.« less

Mitigation of Manhole Events Caused by Secondary Cable Failure

NASA Astrophysics Data System (ADS)

Zhang, Lili

"Manhole event" refers to a range of phenomena, such as smokers, fires and explosions which occur on underground electrical infrastructure, primarily in major cities. The most common cause of manhole events is decomposition of secondary cable initiated by an electric fault. The work presented in this thesis addresses various aspects related to the evolution and mitigation of the manhole events caused by secondary cable insulation failure. Manhole events develop as a result of thermal decomposition of organic materials present in the cable duct and manholes. Polymer characterization techniques are applied to intensively study the materials properties as related to manhole events, mainly the thermal decomposition behaviors of the polymers present in the cable duct. Though evolved gas analysis, the combustible gases have been quantitatively identified. Based on analysis and knowledge of field conditions, manhole events is divided into at least two classes, those in which exothermic chemical reactions dominate and those in which electrical energy dominates. The more common form of manhole event is driven by air flow down the duct. Numerical modeling of smolder propagation in the cable duct demonstrated that limiting air flow is effective in reducing the generation rate of combustible gas, in other words, limiting manhole events to relatively minor "smokers". Besides manhole events, another by-product of secondary cable insulation breakdown is stray voltage. The danger to personnel due to stray voltage is mostly caused by the 'step potential'. The amplitude of step potential as a result of various types of insulation defects is calculated using Finite Element Analysis (FEA) program.

Effects of Various Passivation Layers on Electrical Properties of Multilayer MoS₂ Transistors.

PubMed

Ma, Jiyeon; Yoo, Geonwook

2018-09-01

So far many of research on transition metal dichalcogenides (TMDCs) are based on a bottomgate device structure due to difficulty with depositing a dielectric film on top of TMDs channel layer. In this work, we study different effects of various passivation layers on electrical properties of multilayer MoS2 transistors: spin-coated CYTOP, SU-8, and thermal evaporated MoOX. The SU-8 passivation layer alters device performance least significantly, and MoOX induces positive threshold voltage shift of ~8.0 V due to charge depletion at the interface, and the device with CYTOP layer exhibits decreased field-effect mobility by ~50% due to electric dipole field effect of C-F bonds in the end groups. Our results imply that electrical properties of the multilayer MoS2 transistors can be modulated using a passivation layer, and therefore a proper passivation layer should be considered for MoS2 device structures.

The numerical study of the influence of rheological parameters stratified flows characteristics in cable dies

NASA Astrophysics Data System (ADS)

Kozitsyna, M. V.; Trufanova, N. M.

2017-01-01

Today the process of coextrusion is the most technological in the cable production with cross-linked polyethylene, composed of two or more layers of polymeric insulation. Since the covering technology is a simultaneous imposition of all necessary layers (two semiconducting shields on the insulation and conductor and one - on insulation), the main focus of this study is the analysis of significance of various factors influence on stratified flows characteristics. This paper has considered the flow of two abnormally viscous liquids in the cable head. The problem has been solved through a three-dimensional statement by applying the finite element method in the Ansys software package. The influence has been estimated by varying the rheological properties of materials to create all necessary layers thickness.

Automation of extrusion of porous cable products based on a digital controller

NASA Astrophysics Data System (ADS)

Chostkovskii, B. K.; Mitroshin, V. N.

2017-07-01

This paper presents a new approach to designing an automated system for monitoring and controlling the process of applying porous insulation material on a conductive cable core, which is based on using structurally and parametrically optimized digital controllers of an arbitrary order instead of calculating typical PID controllers using known methods. The digital controller is clocked by signals from the clock length sensor of a measuring wheel, instead of a timer signal, and this provides the robust properties of the system with respect to the changing insulation speed. Digital controller parameters are tuned to provide the operating parameters of the manufactured cable using a simulation model of stochastic extrusion and are minimized by moving a regular simplex in the parameter space of the tuned controller.

Passive lipoidal diffusion and carrier-mediated cell uptake are both important mechanisms of membrane permeation in drug disposition.

PubMed

Smith, Dennis; Artursson, Per; Avdeef, Alex; Di, Li; Ecker, Gerhard F; Faller, Bernard; Houston, J Brian; Kansy, Manfred; Kerns, Edward H; Krämer, Stefanie D; Lennernäs, Hans; van de Waterbeemd, Han; Sugano, Kiyohiko; Testa, Bernard

2014-06-02

Recently, it has been proposed that drug permeation is essentially carrier-mediated only and that passive lipoidal diffusion is negligible. This opposes the prevailing hypothesis of drug permeation through biological membranes, which integrates the contribution of multiple permeation mechanisms, including both carrier-mediated and passive lipoidal diffusion, depending on the compound's properties, membrane properties, and solution properties. The prevailing hypothesis of drug permeation continues to be successful for application and prediction in drug development. Proponents of the carrier-mediated only concept argue against passive lipoidal diffusion. However, the arguments are not supported by broad pharmaceutics literature. The carrier-mediated only concept lacks substantial supporting evidence and successful applications in drug development.

Electrochemical and passive behaviour of tin alloyed ferritic stainless steel in concrete environment

NASA Astrophysics Data System (ADS)

Luo, Hong; Su, Huaizhi; Li, Baosong; Ying, Guobing

2018-05-01

In the present work, the electrochemical behavior and semiconducting properties of a tin alloyed ferritic stainless steel in simulated concrete solution in presence of NaCl were estimated by conventional electrochemical methods such as potentiodynamic polarization, electrochemical impedance spectroscopy, and capacitance measurement (Mott-Schottky approach). The surface passive film was analyzed by X-ray photoelectron spectroscopy. The results revealed a good agreement between pitting corrosion, electrochemical behaviour, and electronic properties. The p and n-type bilayer structure passive film were observed. The increase of Sn4+ oxide species in the passive film shows no beneficial effects on the pitting corrosion. In addition, the dehydration of the passive film was further discussed.

26 CFR 1.469-2 - Passive activity loss.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 6 2011-04-01 2011-04-01 false Passive activity loss. 1.469-2 Section 1.469-2...) INCOME TAXES (CONTINUED) Taxable Year for Which Deductions Taken § 1.469-2 Passive activity loss. (a)-(c... passive activity unless the interest in property was used in a passive activity for either— (1) 20 percent...

46 CFR 111.60-17 - Connections and terminations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... general, connections and terminations to all conductors must retain the original electrical, mechanical, flame-retarding, and, where necessary, fire-resisting properties of the cable. All connecting devices...

46 CFR 111.60-17 - Connections and terminations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... general, connections and terminations to all conductors must retain the original electrical, mechanical, flame-retarding, and, where necessary, fire-resisting properties of the cable. All connecting devices...

KSC-98pc1661

NASA Image and Video Library

1998-11-06

Still suspended by a crane and cables in the Space Station Processing Facility, yet hidden by the top of the Z1 integrated truss structure, the Passive Common Berthing Mechanism (PCBM) is lowered onto the truss for attachment. Workers at the top of a workstand guide it into place. A component of the International Space Station (ISS), the Z1 truss will be used for the temporary installation of the P6 truss segment to the Unity connecting module. The P6 truss segment contains the solar arrays and batteries which will provide early station power. The truss is scheduled to be launched aboard STS-92 in late 1999

Compression-bending of multi-component semi-rigid columns in response to axial loads and conjugate reciprocal extension-prediction of mechanical behaviours and implications for structural design.

PubMed

Lau, Ernest W

2013-01-01

The mathematical modelling of column buckling or beam bending under an axial or transverse load is well established. However, the existent models generally assume a high degree of symmetry in the structure of the column and minor longitudinal and transverse displacements. The situation when the column is made of several components with different mechanical properties asymmetrically distributed in the transverse section, semi-rigid, and subjected to multiple axial loads with significant longitudinal and transverse displacements through compression and bending has not been well characterised. A more comprehensive theoretical model allowing for these possibilities and assuming a circular arc contour for the bend is developed, and used to establish the bending axes, balance between compression and bending, and equivalent stiffness of the column. In certain situations, such as with pull cable catheters commonly used for minimally invasive surgical procedures, the compression loads are applied via cables running through channels inside a semi-rigid column. The model predicts the mathematical relationships between the radius of curvature of the bend and the tension in and normal force exerted by such cables. Conjugate extension with reciprocal compression-bending is a special structural arrangement for a semi-rigid column such that extension of one segment is linked to compression-bending of another by inextensible cables running between them. Leads are cords containing insulated electrical conductor coil and cables between the heart muscle and cardiac implantable electronic devices. Leads can behave like pull cable catheters through differential component pulling, providing a possible mechanism for inside-out abrasion and conductor cable externalisation. Certain design features may predispose to this mode of structural failure. Copyright © 2012 Elsevier Ltd. All rights reserved.

30 CFR 18.36 - Cables between machine components.

Code of Federal Regulations, 2010 CFR

2010-07-01

... protection, (3) insulation compatible with the impressed voltage, and (4) flame-resistant properties unless... mechanical damage by position, flame-resistant hose conduit, metal tubing, or troughs (flexible or threaded...

30 CFR 18.36 - Cables between machine components.

Code of Federal Regulations, 2011 CFR

2011-07-01

... protection, (3) insulation compatible with the impressed voltage, and (4) flame-resistant properties unless... mechanical damage by position, flame-resistant hose conduit, metal tubing, or troughs (flexible or threaded...

Permanent installation of fibre-optic DTS cables in boreholes for temperature monitoring

NASA Astrophysics Data System (ADS)

Henninges, J.; Schrötter, J.; Erbas, K.; Böde, S.; Huenges, E.

2003-04-01

Temperature measurements have become an important tool for the monitoring of dynamic processes in the subsurface both in academia and industry. An innovative experimental design for the monitoring of spatial and temporal variations of temperature along boreholes was developed and successfully applied under extreme arctic conditions during a field experiment, which was carried out within the framework of the Mallik 2002 Production Research Well Program*. Three 40 m spaced, 1200 m deep wells were equipped with permanent fibre-optic sensor cables and the variation of temperature was measured deploying the Distributed Temperature Sensing (DTS) technology. The used DTS system enables the simultaneous online registration of temperature profiles along the three boreholes with a maximum spatial resolution of 0.25 m and a minimum sampling interval of 7 sec. After an individual calibration of the fibre-optic sensor cables a resolution of 0.3 °C of the measured temperature data could be achieved. A special feature of the experiment design is the installation of the sensor cables outside the borehole casing. The fibre-optic cables were attached to the outer side of the casing at every connector within intervals of approx. 12 m with cable clamps. The clamps enable a defined positioning of the cable around the perimeter of the casing and are protecting the cable from mechanical damage during installation. After completion the sensor cables are located in the cement annulus between casing and borehole wall. As an example of the performance of the described temperature logging technology data from the reaming of a 300 m thick cement plug inside the borehole is displayed, offering a unique opportunity to explore thermal processes in the near vicinity of a borehole during drilling. The temperature changes image the progress of the drill bit as well as changes in the mud circulation. Furthermore, local effects can be observed that relate to local thermal properties and technical features of the cable installation. (*) The program participants include 8 partners; The Geological Survey of Canada (GSC), The Japan National Oil Corporation (JNOC), GeoForschungsZentrum Potsdam (GFZ), United States Geological Survey (USGS), United States Department of the Energy (USDOE), India Ministry of Petroleum and Natural Gas (MOPNG)/Gas Authority of India (GAIL) and the Chevron-BP-Burlington joint venture group.

Chinese Passives: Transformational or Lexical?

ERIC Educational Resources Information Center

Zhang, Jiuwu; Wen, Xiaohong

Analysis of Chinese passive constructions indicates two types. The first is a verbal or syntactic passive because it is derived through a transformational rule. The second is a lexical passive that has certain properties in common with the predicate adjectives in both Chinese and English and is derived through the semantic function and in lexical…

Electronic properties and mechanical strength of β-phosphorene nano-ribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swaroop, Ram; Bhatia, Pradeep; Kumar, Ashok, E-mail: ashok@cup.ac.in

We have performed first principles calculations to find out the effect of mechanical strain on the electronic properties of zig-zag edged nano ribbons of β-phosphorene. It is found that electronic band-gap get opened-up to 2.61 eV by passivation of the edges of ribbons. Similarly, the mechanical strength is found to be increase from 1.75 GPa to 2.65 GPa on going from unpassivated nano ribbons to passivated ones along with the 2% increase in ultimate tensile strain. The band-gap value of passivated ribbon gets decreased to 0.43 eV on applying strain up to which the ribbon does not break. These tunable properties ofmore » β-phospherene with passivation with H-atom and applying mechanical strain offer its use in tunable nano electronics.« less

PASSIVE MECHANICAL PROPERTIES AND RELATED PROTEINS CHANGE WITH BOTULINUM NEUROTOXIN A INJECTION OF NORMAL SKELETAL MUSCLE

PubMed Central

Thacker, Bryan E.; Tomiya, Akihito; Hulst, Jonah B.; Suzuki, Kentaro P.; Bremner, Shannon N.; Gastwirt, Randy F.; Greaser, Marion L.; Lieber, Richard L.; Ward, Samuel R.

2011-01-01

Summary The effects of botulinum neurotoxin A on the passive mechanical properties of skeletal muscle have not been investigated, but may have significant impact in the treatment of neuromuscular disorders including spasticity. Single fiber and fiber bundle passive mechanical testing was performed on rat muscles treated with botulinum neurotoxin A. Myosin heavy chain and titin composition of single fibers was determined by gel electrophoresis. Muscle collagen content was determined using a hydroxyproline assay. Neurotoxin-treated single fiber passive elastic modulus was reduced compared to control fibers (53.00 kPa versus 63.43 kPa). Fiber stiffness and slack sarcomere length were also reduced compared to control fibers and myosin heavy chain composition shifted from faster to slower isoforms. Average titin molecular weight increased 1.77% after treatment. Fiber bundle passive elastic modulus increased following treatment (168.83 kPa versus 75.14 kPa). Bundle stiffness also increased while collagen content per mass of muscle tissue increased 38%. Injection of botulinum neurotoxin A produces an effect on the passive mechanical properties of normal muscle that is opposite to the changes observed in spastic muscles. PMID:21853457

Passive mechanical properties and related proteins change with botulinum neurotoxin A injection of normal skeletal muscle.

PubMed

Thacker, Bryan E; Tomiya, Akihito; Hulst, Jonah B; Suzuki, Kentaro P; Bremner, Shannon N; Gastwirt, Randy F; Greaser, Marion L; Lieber, Richard L; Ward, Samuel R

2012-03-01

The effects of botulinum neurotoxin A on the passive mechanical properties of skeletal muscle have not been investigated, but may have significant impact in the treatment of neuromuscular disorders including spasticity. Single fiber and fiber bundle passive mechanical testing was performed on rat muscles treated with botulinum neurotoxin A. Myosin heavy chain and titin composition of single fibers was determined by gel electrophoresis. Muscle collagen content was determined using a hydroxyproline assay. Neurotoxin-treated single fiber passive elastic modulus was reduced compared to control fibers (53.00 kPa vs. 63.43 kPa). Fiber stiffness and slack sarcomere length were also reduced compared to control fibers and myosin heavy chain composition shifted from faster to slower isoforms. Average titin molecular weight increased 1.77% after treatment. Fiber bundle passive elastic modulus increased following treatment (168.83  kPa vs. 75.14 kPa). Bundle stiffness also increased while collagen content per mass of muscle tissue increased 38%. Injection of botulinum neurotoxin A produces an effect on the passive mechanical properties of normal muscle that is opposite to the changes observed in spastic muscles. Copyright © 2011 Orthopaedic Research Society.

Influence of La addition on the semi-conductive properties of passive films formed on Cu-Ni alloy

NASA Astrophysics Data System (ADS)

Leng, Xiang; Zhang, Yadong; Zhou, Qiongyu; Zhang, Yinghui; Wang, Zhigang; Wang, Hang; Yang, Bin

2018-05-01

The semi-conductive properties of passive films formed on Cu-Ni alloy and Cu-Ni-La alloy were investigated in 0.1 M NaOH solution, by employing electrochemical impedance spectroscopy (EIS), Mott–Schottky analysis and point defect model (PDM). Results indicate that both the passive films formed on Cu-Ni alloy and Cu-Ni-La alloy display p-type semi-conductive characteristics with cation vacancies in order of magnitude of 1020 cm3. Compared with Cu-Ni alloy, La addition could significantly improve the corrosion resistance, due to a superior barrier passive film formed Cu-Ni-La alloy with a bigger film resistance (R f), increased passive film thickness (L ss) in conjunction with decreased diffusion coefficient (D 0).

An Introduction to the properties of Superconductors

NASA Astrophysics Data System (ADS)

Letarte, Alec

2001-03-01

A brief introductory presentation of the various properties of superconductors. The discussion will be focussed mainly on the newer ceramic superconductors, but the classic metal ones will also be touched upon. Some of the properties to be considered are: Optical properties, transport properties, persistent currents, coherence length, flux magnetisation, and the ``anti-gravity effect" produced be superconductors Another subject to be looked at will be the recent technological uses and developments of superconductors. For example, they have developed thin superconductors which they are making into a superconducting cable.

Plasmonic nanorod arrays of a two-segment dimer and a coaxial cable with 1 nm gap for large field confinement and enhancement

NASA Astrophysics Data System (ADS)

Cheng, Zi-Qiang; Nan, Fan; Yang, Da-Jie; Zhong, Yu-Ting; Ma, Liang; Hao, Zhong-Hua; Zhou, Li; Wang, Qu-Quan

2015-01-01

Seeking plasmonic nanostructures with large field confinement and enhancement is significant for photonic and electronic nanodevices with high sensitivity, reproducibility, and tunability. Here, we report the synthesis of plasmonic arrays composed of two-segment dimer nanorods and coaxial cable nanorods with ~1 nm gap insulated by a self-assembled Raman molecule monolayer. The gap-induced plasmon coupling generates an intense field in the gap region of the dimer junction and the cable interlayer. As a result, the longitudinal plasmon resonance of nanorod arrays with high tunability is obviously enhanced. Most interestingly, the field enhancement of dimer nanorod arrays can be tuned by the length ratio L1/L2 of the two segments, and the maximal enhancement appears at L1/L2 = 1. In that case, the two-photon luminescence (TPL) of dimer nanorod arrays and the Raman intensity in the dimer junction is enhanced by 27 and 30 times, respectively, under resonant excitation. In the same way, the Raman intensity in the gap region is enhanced 16 times for the coaxial cable nanorod arrays. The plasmonic nanorod arrays synthesized by the facile method, having tunable plasmon properties and large field enhancement, indicate an attractive pathway to the photonic nanodevices.Seeking plasmonic nanostructures with large field confinement and enhancement is significant for photonic and electronic nanodevices with high sensitivity, reproducibility, and tunability. Here, we report the synthesis of plasmonic arrays composed of two-segment dimer nanorods and coaxial cable nanorods with ~1 nm gap insulated by a self-assembled Raman molecule monolayer. The gap-induced plasmon coupling generates an intense field in the gap region of the dimer junction and the cable interlayer. As a result, the longitudinal plasmon resonance of nanorod arrays with high tunability is obviously enhanced. Most interestingly, the field enhancement of dimer nanorod arrays can be tuned by the length ratio L1/L2 of the two segments, and the maximal enhancement appears at L1/L2 = 1. In that case, the two-photon luminescence (TPL) of dimer nanorod arrays and the Raman intensity in the dimer junction is enhanced by 27 and 30 times, respectively, under resonant excitation. In the same way, the Raman intensity in the gap region is enhanced 16 times for the coaxial cable nanorod arrays. The plasmonic nanorod arrays synthesized by the facile method, having tunable plasmon properties and large field enhancement, indicate an attractive pathway to the photonic nanodevices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05544f

New Technologies for Repairing Aging Cables in Nuclear Power Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simmons, Kevin L.; Fifield, Leonard S.; Westman, Matthew P.

The goal of this project is to demonstrate a proof-of-concept for a technique to repair aging cables that have been subjected to degradation associated with long-term thermal and radiation exposure in nuclear power plants. The physical degradation of the aging cables manifests itself primarily as cracking and increased brittleness of the polymeric electrical insulation. Therefore, the proposed cable-repair concept comprises development of techniques to impart a softening agent within the deteriorated polymer insulation jacket so as to regain the ability of the insulation to stretch without failing and possibly to heal existing cracks in the insulation. Our approach is tomore » use commercially available ethylene-propylene rubber (EPR) as the relevant test material, demonstrate the adsorption of chemical treatments in the EPR and quantify changes in resulting physical and mechanical properties. EPR cable samples have been thermally treated in air to produce specimens corresponding to the full range of cable age-performance points from new (>350% elongation at break) to end-of-life (<50% elongation at break). The current focus is on two chemical treatments selected as candidates for restoring age-related cable elasticity loss: a rubber plasticizer and a reactive silane molecule. EPR specimens of 200, 150, 100, and 50% elongation at break have been soaked in the candidate chemical treatments and the kinetics of chemical uptake, measured by change in mass of the samples, has been determined. Mechanical properties as a function of aging and chemical treatment have been measured including ultimate tensile strength, tensile modulus at 50% strain, elongation at break, and storage modulus. Dimensional changes with treatment and changes in glass transition temperature were also investigated. These ongoing experiments are expected to provide insight into the physical-chemical nature of the effect of thermal degradation on EPR rejuvenation limits and to advance novel methods for restoring the ability of degraded EPR to be compliant and resist fracture. The results of this research reveal that absorption of chemical treatments can lower the glass transition temperature and modulus of EPR. Chemical treatments pursued thus far have proven ineffective at restoring EPR strength and elongation at break. Future work will combine the plasticizer modalities found to successfully increase the volume of the EPR, reduce EPR glass transition temperature and reduce EPR modulus with promising chemistries that will repair the damage of the polymer, potentially using the plasticizer as a host for the new chemistry.« less

Controlling the Optical and Magnetic Properties of Nanostructured Cuprous Oxide Synthesized from Waste Electric Cables

NASA Astrophysics Data System (ADS)

Abdelbasir, S. M.; El-Sheikh, S. M.; Rashad, M. M.; Rayan, D. A.

2018-03-01

Cuprous oxide Cu2O nanopowders were purposefully synthesised from waste electric cables (WECs) via a simple precipitation route at room temperature using lactose as a reducing agent. In this regard, dimethyl sulfoxide (DMSO) was first applied as an organic solvent for the dissolution of the cable insulating materials. Several parameters were investigated during dissolution of WECs such as dissolution temperature, time and solid/liquid ratio to determine the dissolution percentage of the insulating materials in DMSO. The morphology and the optical properties of the formed Cu2O particles were investigated using X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy and UV-visible-near IR spectrophotometer. XRD data confirmed the presence of single crystalline phase of Cu2O nanoparticles. FE-SEM and TEM images revealed spherical, cubic and octahedral shapes with the various particle sizes ranged from 16 to 57 nm depending on the synthesis conditions. A possible mechanism explaining the Cu2O nanostructures formation was proposed. The band gap energies of the Cu2O nanostructures were estimated and the values were located between 1.5 and 2.08 eV. Photoluminescence spectroscopy analysis clearly showed a noticeably blue-shifted emission for the synthesized samples compared to spectrum of the bulk. Eventually, magnetic properties of the synthesized nanoparticles have been measured by vibrating sample magnetometer and the attained results implied that the synthesized particles are weakly ferromagnetic in nature at normal temperature.

AC loss, interstrand resistance and mechanical properties of prototype EU DEMO TF conductors up to 30 000 load cycles

NASA Astrophysics Data System (ADS)

Yagotintsev, K.; Nijhuis, A.

2018-07-01

Two prototype Nb3Sn cable-in-conduit conductors conductors were designed and manufactured for the toroidal field (TF) magnet system of the envisaged European DEMO fusion reactor. The AC loss, contact resistance and mechanical properties of two sample conductors were tested in the Twente Cryogenic Cable Press under cyclic load up to 30 000 cycles. Though both conductors were designed to operate at 82 kA in a background magnetic field of 13.6 T, they reflect different approaches with respect to the magnet winding pack assembly. The first approach is based on react and wind technology while the second is the more common wind and react technology. Each conductor was tested first for AC loss in virgin condition without handling. The impact of Lorentz load during magnet operation was simulated using the cable press. In the press each conductor specimen was subjected to transverse cyclic load up to 30 000 cycles in liquid helium bath at 4.2 K. Here a summary of results for AC loss, contact resistance, conductor deformation, mechanical heat production and conductor stiffness evolution during cycling of the load is presented. Both conductors showed similar mechanical behaviour but quite different AC loss. In comparison with previously tested ITER TF conductors, both DEMO TF conductors possess very low contact resistance resulting in high coupling loss. At the same time, load cycling has limited impact on properties of DEMO TF conductors in comparison with ITER TF conductors.

SisterTalk: final results of a culturally tailored cable television delivered weight control program for Black women

PubMed Central

2013-01-01

Background Obesity among Black women continues to exceed that of other women. Most weight loss programs created without reference to specific cultural contexts are less effective for Black than White women. Weight control approaches accessible to Black women and adapted to relevant cultural contexts are important for addressing this problem. This paper reports the final results of SisterTalk, the randomized controlled trial of a cable TV weight control program oriented toward Black women. Methods A five group design included a comparison group and a 2 × 2 factorial comparison of a) interactive vs. passive programming and b) telephone social support vs no telephone support, with 12 weekly initial cable TV programs followed by 4 monthly booster videos. At baseline, 3, 8, and 12 months post randomization, telephone and in person surveys were administered on diet, physical activity, and physical measurements of height and weight were taken to calculate body mass index (BMI). Analysis of variance (ANOVA) was used to examine differences over time, and between treatment and comparison groups. Dose variables reflecting use of the TV/video and written materials were also assessed. Results At 3 months, BMI, weight, and dietary fat were significantly lower and physical activity significantly higher among women exposed to the Cable TV intervention compared to the wait-list comparison group. Significant dietary fat differences were still observed at 8 and 12 month evaluations, but not BMI or physical activity differences. Main effects were not observed for interactive programming or enhanced social support at any time point. Within the intervention group, higher watching of the TV series and higher reading of educational materials were both (separately) associated with significantly lower dietary fat. Conclusions Cable TV was an effective delivery channel to assist Black women with weight control, increasing physical activity and decreasing dietary fat during an initial intervention period, but only dietary changes persisted Enhanced social support and the ability to interact with others during the show were not effective complementary intervention components as conducted in this trial. Future research to strengthen the ability of this approach to achieve long term effects may offer even more promising outcomes. PMID:24373253

Membrane hydrophone phase characteristics through nonlinear acoustics measurements.

PubMed

Bloomfield, Philip E; Gandhi, Gaurav; Lewin, Peter A

2011-11-01

This work considers the need for both the amplitude and phase to fully characterize polyvinylidene fluoride (PVDF) membrane hydrophones and presents a comprehensive discussion of the nonlinear acoustic measurements utilized to extract the phase information and the experimental results taken with two widely used PVDF membrane hydrophones up to 100 MHz. A semi-empirical computer model utilized the hyperbolic propagation operator to predict the nonlinear pressure field and provide the complex frequency response of the corresponding source transducer. The PVDF hydrophone phase characteristics, which were obtained directly from the difference between the computer-modeled nonlinear field simulation and the corresponding measured harmonic frequency phase values, agree to within 10% with the phase predictions obtained from receive-transfer-function simulations based on software modeling of the membrane's physical properties. Cable loading effects and membrane hydrophone resonances were distinguished and identified through a series of impedance measurements and receive transfer function simulations on the hydrophones including their hard-wired coaxial cables. The results obtained indicate that the PVDF membrane hydrophone's phase versus frequency plot exhibits oscillations about a monotonically decreasing line. The maxima and minima inflection point slopes occur at the membrane thickness resonances and antiresonances, respectively. A cable resonance was seen at 100 MHz for the hydrophone with a 1-m cable attached, but not seen for the hydrophone with a shorter 0.65-m cable.

Thermal Conductivity in Soil: Theoretical Approach by 3D Infinite Resistance Grid Model

NASA Astrophysics Data System (ADS)

Changjan, A.; Intaravicha, N.

2018-05-01

Thermal conductivity in soil was elementary characteristic of soil that conduct heat, measured in terms of Fourier’s Law for heat conduction and useful application in many fields: such as Utilizing underground cable for transmission and distribution systems, the rate of cooling of the cable depends on the thermal properties of the soil surrounding the cable. In this paper, we investigated thermal conductivity in soil by infinite three dimensions (3D) electrical resistance circuit concept. Infinite resistance grid 3D was the grid of resistors that extends to infinity in all directions. Model of thermal conductivity in soil of this research was generated from this concept: comparison between electrical resistance and thermal resistance in soil. Finally, we investigated the analytical form of thermal conductivity in soil which helpful for engineering and science students that could exhibit education with a principle of physics that applied to real situations.

Automatic modal identification of cable-supported bridges instrumented with a long-term monitoring system

NASA Astrophysics Data System (ADS)

Ni, Y. Q.; Fan, K. Q.; Zheng, G.; Chan, T. H. T.; Ko, J. M.

2003-08-01

An automatic modal identification program is developed for continuous extraction of modal parameters of three cable-supported bridges in Hong Kong which are instrumented with a long-term monitoring system. The program employs the Complex Modal Indication Function (CMIF) algorithm to identify modal properties from continuous ambient vibration measurements in an on-line manner. By using the LabVIEW graphical programming language, the software realizes the algorithm in Virtual Instrument (VI) style. The applicability and implementation issues of the developed software are demonstrated by using one-year measurement data acquired from 67 channels of accelerometers deployed on the cable-stayed Ting Kau Bridge. With the continuously identified results, normal variability of modal vectors caused by varying environmental and operational conditions is observed. Such observation is very helpful for selection of appropriate measured modal vectors for structural health monitoring applications.

Method and device for tensile testing of cable bundles

DOEpatents

Robertson, Lawrence M; Ardelean, Emil V; Goodding, James C; Babuska, Vit

2012-10-16

A standard tensile test device is improved to accurately measure the mechanical properties of stranded cables, ropes, and other composite structures wherein a witness is attached to the top and bottom mounting blocks holding the cable under test. The witness is comprised of two parts: a top and a bottom rod of similar diameter with the bottom rod having a smaller diameter stem on its upper end and the top rod having a hollow opening in its lower end into which the stem fits forming a witness joint. A small gap is present between the top rod and the larger diameter portion of the bottom rod. A standard extensometer is attached to the top and bottom rods of the witness spanning this small witness gap. When a force is applied to separate the mounting blocks, the gap in the witness expands the same length that the entire test specimen is stretched.

A passive optical fibre hydrophone array utilising fibre Bragg grating sensors

NASA Astrophysics Data System (ADS)

Karas, Andrew R.; Papageorgiou, Anthony W.; Cook, Peter R.; Arkwright, John W.

2018-02-01

Many current high performance hydrophones use piezo-electric technology to measure sound pressure in water. These hydrophones are sensitive enough to detect any sound above the lowest ambient ocean acoustic noise, however cost of manufacture, weight and storage volume of the array as well as deployment and maintenance costs can limit their largescale application. Piezo-electric systems also have issues with electro-magnetic interference and the signature of the electrical cabling required in a large array. A fibre optic hydrophone array has advantages over the piezo-electric technology in these areas. This paper presents the operating principle of a passive optical fibre hydrophone array utilising Fibre Bragg Gratings (FBGs). The multiple FBG sensors are interrogated using a single solid state spectrometer which further reduces the cost of the deployed system. A noise equivalent power (NEP) comparison of the developed FBG hydrophone versus an existing piezo-electric hydrophone is presented as well as a comparison to the lowest ambient ocean acoustic noise (sea state zero). This research provides an important first step towards a cost effective multi sensor hydrophone array using FBGs.

Real-time monitoring and fault locating using amplified spontaneous emission noise reflection for tree-structured Ethernet passive optical networks

NASA Astrophysics Data System (ADS)

Naim, Nani Fadzlina; Ab-Rahman, Mohammad Syuhaimi; Kamaruddin, Nur Hasiba; Bakar, Ahmad Ashrif A.

2013-09-01

Nowadays, optical networks are becoming dense while detecting faulty branches in the tree-structured networks has become problematic. Conventional methods are inconvenient as they require an engineer to visit the failure site to check the optical fiber using an optical time-domain reflectometer. An innovative monitoring technique for tree-structured network topology in Ethernet passive optical networks (EPONs) by using the erbium-doped fiber amplifier to amplify the traffic signal is demonstrated, and in the meantime, a residual amplified spontaneous emission spectrum is used as the input signal to monitor the optical cable from the central office. Fiber Bragg gratings with distinct center wavelengths are employed to reflect the monitoring signals. Faulty branches of the tree-structured EPONs can be identified using a simple and low-cost receiver. We will show that this technique is capable of providing monitoring range up to 32 optical network units using a power meter with a sensitivity of -65 dBm while maintaining the bit error rate of 10-13.

Toward a unified model of passive drug permeation II: the physiochemical determinants of unbound tissue distribution with applications to the design of hepatoselective glucokinase activators.

PubMed

Ghosh, Avijit; Maurer, Tristan S; Litchfield, John; Varma, Manthema V; Rotter, Charles; Scialis, Renato; Feng, Bo; Tu, Meihua; Guimaraes, Cris R W; Scott, Dennis O

2014-10-01

In this work, we leverage a mathematical model of the underlying physiochemical properties of tissues and physicochemical properties of molecules to support the development of hepatoselective glucokinase activators. Passive distribution is modeled via a Fick-Nernst-Planck approach, using in vitro experimental data to estimate the permeability of both ionized and neutral species. The model accounts for pH and electrochemical potential across cellular membranes, ionization according to Henderson-Hasselbalch, passive permeation of the neutral species using Fick's law, and passive permeation of the ionized species using the Nernst-Planck equation. The mathematical model of the physiochemical system allows derivation of a single set of parameters governing the distribution of drug molecules across multiple conditions both in vitro and in vivo. A case study using this approach in the development of hepatoselective glucokinase activators via organic anion-transporting polypeptide-mediated hepatic uptake and impaired passive distribution to the pancreas is described. The results for these molecules indicate the permeability penalty of the ionized form is offset by its relative abundance, leading to passive pancreatic exclusion according to the Nernst-Planck extension of Fickian passive permeation. Generally, this model serves as a useful construct for drug discovery scientists to understand subcellular exposure of acids or bases using specific physiochemical properties. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

GPON FTTH trial: lessons learned

NASA Astrophysics Data System (ADS)

Weis, Erik; Hölzl, Rainer; Breuer, Dirk; Lange, Christoph

2009-11-01

This paper reports on a FTTH field trial with GPON (Gigabit-capable passive optical network) technology in the network of Deutsche Telekom in the region of the cities of Berlin and Potsdam. Focus of this trial was to gain practical experience regarding GPON technology, fibre installation in existing ducts with micro duct technology, fibre cabling in customer buildings and impact on operational processes. Furthermore it is reported on an initial Deutsche Telekom FTTB deployment based on GPON technology in the city of Dresden with the main targets to obtain practical deployment and operation experiences with fibre-based access networks and to provide broadband access to a part of the city formerly not servable by DSL (digital subscriber line) technology.

Effects of annealing and conformal alumina passivation on anisotropy and hysteresis of magneto-optical properties of cobalt slanted columnar thin films

NASA Astrophysics Data System (ADS)

Briley, Chad; Mock, Alyssa; Korlacki, Rafał; Hofmann, Tino; Schubert, Eva; Schubert, Mathias

2017-11-01

We present magneto-optical dielectric tensor data of cobalt and cobalt oxide slanted columnar thin films obtained by vector magneto-optical generalized ellipsometry. Room-temperature hysteresis magnetization measurements were performed in longitudinal and polar Kerr geometries on samples prior to and after a heat treatment process with and without a conformal Al2O3 passivation coating. The samples have been characterized by generalized ellipsometry, scanning electron microscopy, and Raman spectroscopy in conjuncture with density functional theory. We observe strongly anisotropic hysteresis behaviors, which depend on the nanocolumn and magnetizing field orientations. We find that deposited cobalt films that have been exposed to heat treatment and subsequent atmospheric oxidation into Co3O4, when not conformally passivated, reveal no measurable magneto-optical properties while cobalt films with passivation coatings retain highly anisotropic magneto-optical properties.

Spacesuit Soft Upper Torso Sizing Systems

NASA Technical Reports Server (NTRS)

Graziosi, David; Splawn, Keith

2011-01-01

The passive sizing system consists of a series of low-profile pulleys attached to the front and back of the shoulder bearings on a spacesuit soft upper torso (SUT), textile cord or stainless steel cable, and a modified commercial ratchet mechanism. The cord/cable is routed through the pulleys and attached to the ratchet mechanism mounted on the front of the spacesuit within reach of the suited subject. Upon actuating the ratchet mechanism, the shoulder bearing breadth is changed, providing variable upper torso sizing. The active system consists of a series of pressurizable nastic cells embedded into the fabric layers of a spacesuit SUT. These cells are integrated to the front and back of the SUT and are connected to an air source with a variable regulator. When inflated, the nastic cells provide a change in the overall shoulder bearing breadth of the spacesuit and thus, torso sizing. The research focused on the development of a high-performance sizing and actuation system. This technology has application as a suit-sizing mechanism to allow easier suit entry and more accurate suit fit with fewer torso sizes than the existing EMU (Extravehicular Mobility Unit) suit system. This advanced SUT will support NASA s Advanced EMU Evolutionary Concept of a two-sizes-fit-all upper torso for replacement of the current EMU hard upper torso (HUT). Both the passive and nastic sizing system approaches provide astronauts with real-time upper torso sizing, which translates into a more comfortable suit, providing enhanced fit resulting in improved crewmember performance during extravehicular activity. These systems will also benefit NASA by reducing flight logistics as well as overall suit system cost. The nastic sizing system approach provides additional structural redundancy over existing SUT designs by embedding additional coated fabric and uncoated fabric layers. Two sizing systems were selected to build into a prototype SUT: one active and one passive. From manned testing, it was found that both systems offer good solutions to sizing a SUT to fit a crewmember. This new system provided improved suit don/doff over existing spacesuit designs as well as providing better fit at suit operational pressure resulting in improved comfort and mobility. It was found that a SUT with a sizing system may solve several problems that have plagued existing HUT designs, and that a SUT with a sizing system may be a viable option for advanced suit architectures.

Fluorine incorporation in solution-processed poly-siloxane passivation for highly reliable a-InGaZnO thin-film transistors

NASA Astrophysics Data System (ADS)

Yoshida, Naofumi; Bermundo, Juan Paolo; Ishikawa, Yasuaki; Nonaka, Toshiaki; Taniguchi, Katsuto; Uraoka, Yukiharu

2018-03-01

We investigated a fluorine-containing polysiloxane (Poly-SX) passivation layer fabricated by solution process for amorphous InGaZnO (a-IGZO) thin-film transistors (TFT). This passivation layer greatly improved the stability of the a-IGZO device even after being subjected to positive bias stress (PBS) and negative bias stress (NBS). The mobility (µ) of TFTs passivated by fluorine-containing Poly-SX increased by 31%-56% (10.50-12.54 cm2 V-1 s-1) compared with TFTs passivated by non-fluorinated Poly-SX (8.04 cm2 V-1 s-1). Increasing the amount of fluorine additives led to a higher µ in passivated TFTs. Aside from enhancing the performance, these passivation layers could increase the reliability of a-IGZO TFTs under PBS and NBS with a minimal threshold voltage shift (ΔV th) of up to  +0.2 V and  -0.1 V, respectively. Additionally, all TFTs passivated by the fluorinated passivation materials did not exhibit a hump effect after NBS. We also showed that fluorinated photosensitive Poly-SX, which can be fabricated without any dry etching process, had an effective passivation property. In this report, we demonstrated the photolithography of Poly-SX, and electrical properties of Poly-SX passivated TFTs, and analyzed the state of the a-IGZO layer to show the large potential of Poly-SX as an effective solution-processed passivation material.

Effect of temperature on the passivation behavior of steel rebar

NASA Astrophysics Data System (ADS)

Chen, Shan-meng; Cao, Bei; Wu, Yin-shun; Ma, Ke

2014-05-01

Steel rebar normally forms an oxide or rusty skin before it is embedded into concrete and the passivation properties of this skin will be heavily influenced by temperature. To study the effect of temperature on the passivation properties of steel rebar under different surface conditions, we conducted scanning electron microscopy (SEM) observations and electrochemical measurements, such as measurements of the free corrosion potential and polarization curves of HPB235 steel rebar. These measurements identified three kinds of surfaces: polished, oxide skin, and rusty skin. Our results show that the passivation properties of all the surface types decrease with the increase of temperature. Temperature has the greatest effect on the rusty-skin rebar and least effect on the polished steel rebar, because of cracks and crevices on the mill scale on the steel rebar's surface. The rusty-skin rebar exhibits the highest corrosion rate because crevice corrosion can accelerate the corrosion of the steel rebar, particularly at high temperature. The results also indicate that the threshold temperatures of passivation for the oxide-skin rebar and the rusty-skin rebar are 37°C and 20°C, respectively.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behnke, M. R.; Bellei, T.A.; Bloethe, W.G.

This paper presents a summary of the most impor- tant considerations for wind power plant collection system un- derground and overhead cable designs. Various considerations, including conductor selection, soil thermal properties, installa- tion methods, splicing, concentric grounding, and NESC/NEC requirements are discussed.

Electronic structure and magnetic properties of zigzag blue phosphorene nanoribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Tao; Hong, Jisang, E-mail: hongj@pknu.ac.kr

2015-08-07

We investigated the electronic structure and magnetism of zigzag blue phosphorene nanoribbons (ZBPNRs) using first principles density functional theory calculations by changing the widths of ZBPNRs from 1.5 to 5 nm. In addition, the effect of H and O passivation was explored as well. The ZBPNRs displayed intra-edge antiferromagnetic ground state with a semiconducting band gap of ∼0.35 eV; and this was insensitive to the edge structure relaxation effect. However, the edge magnetism of ZBPNRs disappeared with H-passivation. Moreover, the band gap of H-passivated ZBPNRs was greatly enhanced because the calculated band gap was ∼1.77 eV, and this was almost the same asmore » that of two-dimensional blue phosphorene layer. For O-passivated ZBPNRs, we also found an intra-edge antiferromagnetic state. Besides, both unpassivated and O-passivated ZBPNRs preserved almost the same band gap. We predict that the electronic band structure and magnetic properties can be controlled by means of passivation. Moreover, the edge magnetism can be also modulated by the strain. Nonetheless, the intrinsic physical properties are size independent. This feature can be an advantage for device applications because it may not be necessary to precisely control the width of the nanoribbon.« less

A deep-level transient spectroscopy study of gamma-ray irradiation on the passivation properties of silicon nitride layer on silicon

NASA Astrophysics Data System (ADS)

Dong, Peng; Yu, Xuegong; Ma, Yao; Xie, Meng; Li, Yun; Huang, Chunlai; Li, Mo; Dai, Gang; Zhang, Jian

2017-08-01

Plasma-enhanced chemical vapor deposited silicon nitride (SiNx) films are extensively used as passivation material in the solar cell industry. Such SiNx passivation layers are the most sensitive part to gamma-ray irradiation in solar cells. In this work, deep-level transient spectroscopy has been applied to analyse the influence of gamma-ray irradiation on the passivation properties of SiNx layer on silicon. It is shown that the effective carrier lifetime decreases with the irradiation dose. At the same time, the interface state density is significantly increased after irradiation, and its energy distribution is broadened and shifts deeper with respect to the conduction band edge, which makes the interface states becoming more efficient recombination centers for carriers. Besides, C-V characteristics show a progressive negative shift with increasing dose, indicating the generation of effective positive charges in SiNx films. Such positive charges are beneficial for shielding holes from the n-type silicon substrates, i. e. the field-effect passivation. However, based on the reduced carrier lifetime after irradiation, it can be inferred that the irradiation induced interface defects play a dominant role over the trapped positive charges, and therefore lead to the degradation of passivation properties of SiNx on silicon.

A biomechanical comparison of three sternotomy closure techniques.

PubMed

Cohen, David J; Griffin, Lanny V

2002-02-01

A biomechanical study of three sternotomy closure techniques (figure-of-eight stainless-steel wires, Pectofix Dynamic Sternal Fixation [DSF] stainless-steel plates, and figure-of-eight stainless-steel cables) was conducted to compare strength and stiffness variables in three clinically relevant loading modes (anterior-posterior shear, longitudinal shear, and lateral distraction). All tests were conducted on polyurethane foam sternal models that simulate the properties of cancellous bone. Each model was divided longitudinally and reconstructed using one of the sternotomy closure repair techniques. Tests were performed using a materials testing system that applies a continuously increasing amount of force in one direction to the model until it catastrophically breaks. A total of six trials of each fixation type in each of three test groups were prepared and tested, for a total of 54 tests. Strength and stiffness variables as well as a post-yield analysis of failure were evaluated. Sternums repaired using the DSF plate system are a more rigid construct than sternums repaired using the stainless-steel wires or cables in the distraction and transverse shear modes and they are not significantly different from sternums repaired with wires or cables in the longitudinal shear mode. The DSF plate system offers a 25% improvement in resistance to failure (yield) compared to wires when a transverse shear force is applied to the model. The cable system had a higher resistance to failure than the wires in all modes although the differences were not statistically significant. Additionally, the DSF plate system provides substantial reduction of the implant's cutting into the sternal model under loading as evidenced by the post-yield displacement when compared with either cables or wires for the distraction and longitudinal shear modes. For the transverse shear mode, the cables or wires would completely fail at the load for which cutting begins for the DSF. Both the DSF plate system and the stainless-steel cable system offer important advantages over figure-of-eight wire for sternal closure.

Health monitoring and rehabilitation of a concrete structure using intelligent materials

NASA Astrophysics Data System (ADS)

Song, G.; Mo, Y. L.; Otero, K.; Gu, H.

2006-04-01

This paper presents the concept of an intelligent reinforced concrete structure (IRCS) and its application in structural health monitoring and rehabilitation. The IRCS has multiple functions which include self-rehabilitation, self-vibration damping, and self-structural health monitoring. These functions are enabled by two types of intelligent (smart) materials: shape memory alloys (SMAs) and piezoceramics. In this research, Nitinol type SMA and PZT (lead zirconate titanate) type piezoceramics are used. The proposed concrete structure is reinforced by martensite Nitinol cables using the method of post-tensioning. The martensite SMA significantly increases the concrete's damping property and its ability to handle large impact. In the presence of cracks due to explosions or earthquakes, by electrically heating the SMA cables, the SMA cables contract and close up the cracks. In this research, PZT patches are embedded in the concrete structure to detect possible cracks inside the concrete structure. The wavelet packet analysis method is then applied as a signal-processing tool to analyze the sensor signals. A damage index is defined to describe the damage severity for health monitoring purposes. In addition, by monitoring the electric resistance change of the SMA cables, the crack width can be estimated. To demonstrate this concept, a concrete beam specimen with reinforced SMA cables and with embedded PZT patches is fabricated. Experiments demonstrate that the IRC has the ability of self-sensing and self-rehabilitation. Three-point bending tests were conducted. During the loading process, a crack opens up to 0.47 inches. Upon removal of the load and heating the SMA cables, the crack closes up. The damage index formed by wavelet packet analysis of the PZT sensor data predicts and confirms the onset and severity of the crack during the loading. Also during the loading, the electrical resistance value of the SMA cable changes by up to 27% and this phenomenon is used to monitor the crack width.

Transforming Ocean Sciences in the Northeast Pacific: NSF's Ocean Observatories Initiative Cabled Array is Now Operational

NASA Astrophysics Data System (ADS)

Kelley, D. S.

2016-02-01

In July-August, 2015 the first operations and maintenance cruise was successfully completed for the high power and bandwidth underwater cabled component of the National Science Foundation's Ocean Observatories Initiative: the Cabled Array. This system includes 900 km of backbone cable and 7 Primary Nodes, which provide 8 kW power and 10 Gbs bandwidth to myriad seafloor instruments (Manalang et al., this meeting) and instrumented full water column moorings (McRae et al., this meeting). Over 33,000 m of extension cables connected to 17 secondary junction boxes support >100 instruments now streaming data live to shore. In concert, this array forms: 1) the most advanced observatory along the global mid-ocean ridge network were 20 instruments and a state-of-the-art mooring system are providing new insights into volcanic and overlying water column processes at Axial Seamount (which erupted April 2015, see Delaney et al., this meeting); and 2) an extensive, technologically-advanced coastal observatory spanning 80 m to 2900 m water depths off Newport, OR. Here, cabled, instrumented moorings, with up to 18 instruments each, and associated seafloor arrays provide real-time, coregistered geophysical, biogeochemical, and physical measurements at unprecedented temporal and spatial resolution. Nearly 1.5 years of continuous data (see Knuth et al., this meeting), two-way communication capabilities that allow responses to events, and continuing real-time data flow, will allow the community to investigate in ways never before possible earthquakes along the Cascadia margin with impacts on fluid flow and release of methane into the hydrosphere, underwater eruptions resulting in perturbations to hydrothermal systems, associated biological communities, and overlying water column properties, and linkages among biogeochemical and physical processes along the Cascadia margin.

The correlation between elongation at break and thermal decomposition of aged EPDM cable polymer

NASA Astrophysics Data System (ADS)

Šarac, T.; Devaux, J.; Quiévy, N.; Gusarov, A.; Konstantinović, M. J.

2017-03-01

The effect of simultaneous thermal and gamma irradiation ageing on the mechanical and physicochemical properties of industrial EPDM was investigated. Accelerated ageing, covering a wide range of dose rates, doses and temperatures, was preformed in stagnant air on EPDM polymer samples extracted from the cables in use in the Belgian nuclear power plants. The mechanical properties, ultimate tensile stress and elongation at break, are found to exhibit the strong dependence on the dose, ageing temperature and dose rate. The thermal decomposition of aged polymer is observed to be the dose dependent when thermogravimetry test is performed under air atmosphere. No dose dependence is observed when thermal decomposition is performed under nitrogen atmosphere. The thermal decomposition rates are found to fully mimic the reduction of elongation at break for all dose rates and ageing temperatures. This effect is argued to be the result of thermal and radiation mediated oxidation degradation process.

Magnetic resonance conditional paramagnetic choke for suppression of imaging artifacts during magnetic resonance imaging.

PubMed

Wu, Kevin J; Gregory, T Stan; Boland, Brian L; Zhao, Wujun; Cheng, Rui; Mao, Leidong; Tse, Zion Tsz Ho

2018-06-01

Higher risk patient populations require continuous physiological monitoring and, in some cases, connected life-support systems, during magnetic resonance imaging examinations. While recently there has been a shift toward wireless technology, some of the magnetic resonance imaging devices are still connected to the outside using cabling that could interfere with the magnetic resonance imaging's radio frequency during scanning, resulting in excessive heating. We developed a passive method for radio frequency suppression on cabling that may assist in making some of these devices magnetic resonance imaging compatible. A barrel-shaped strongly paramagnetic choke was developed to suppress induced radio frequency signals which are overlaid onto physiological monitoring leads during magnetic resonance imaging. It utilized a choke placed along the signal lines, with a gadolinium solution core. The choke's magnetic susceptibility was modeled, for a given geometric design, at increasing chelate concentration levels, and measured using a vibrating sample magnetometer. Radio frequency noise suppression versus frequency was quantified with network-analyzer measurements and tested using cabling placed in the magnetic resonance imaging scanner. Temperature-elevation and image-quality reduction due to the device were measured using American Society for Testing and Materials phantoms. Prototype chokes with gadolinium solution cores exhibited increasing magnetic susceptibility, and insertion loss (S21) also showed higher attenuation as gadolinium concentration increased. Image artifacts extending <4 mm from the choke were observed during magnetic resonance imaging, which agreed well with the predicted ∼3 mm artifact from the electrochemical machining simulation. An accompanying temperature increase of <1 °C was observed in the magnetic resonance imaging phantom trial. An effective paramagnetic choke for radio frequency suppression during magnetic resonance imaging was developed and its performance demonstrated.

Towards Noise Tomography and Passive Monitoring Using Distributed Acoustic Sensing

NASA Astrophysics Data System (ADS)

Paitz, P.; Fichtner, A.

2017-12-01

Distributed Acoustic Sensing (DAS) has the potential to revolutionize the field of seismic data acquisition. Thanks to their cost-effectiveness, fiber-optic cables may have the capability of complementing conventional geophones and seismometers by filling a niche of applications utilizing large amounts of data. Therefore, DAS may serve as an additional tool to investigate the internal structure of the Earth and its changes over time; on scales ranging from hydrocarbon or geothermal reservoirs to the entire globe. An additional potential may be in the existence of large fibre networks deployed already for telecommunication purposes. These networks that already exist today could serve as distributed seismic antennas. We investigate theoretically how ambient noise tomography may be used with DAS data. For this we extend the theory of seismic interferometry to the measurement of strain. With numerical, 2D finite-difference examples we investigate the impact of source and receiver effects. We study the effect of heterogeneous source distributions and the cable orientation by assessing similarities and differences to the Green's function. We also compare the obtained interferometric waveforms from strain interferometry to displacement interferometric wave fields obtained with existing methods. Intermediate results show that the obtained interferometric waveforms can be connected to the Green's Functions and provide consistent information about the propagation medium. These simulations will be extended to reservoir scale subsurface structures. Future work will include the application of the theory to real-data examples. The presented research depicts the early stage of a combination of theoretical investigations, numerical simulations and real-world data applications. We will therefore evaluate the potentials and shortcomings of DAS in reservoir monitoring and seismology at the current state, with a long-term vision of global seismic tomography utilizing DAS data from existing fiber-optic cable networks.

Modulation of electronic transport properties in armchair phosphorene nanoribbons by doping and edge passivation.

PubMed

Guo, Caixia; Wang, Tianxing; Xia, Congxin; Liu, Yufang

2017-10-09

The electronic structures and transport properties of group IV atoms (C, Si, Ge)-doped armchair phosphorene nanoribbons (APNRs) are investigated using first-principles calculations, considering different edge passivation. The results show that the C, Si, Ge dopants can induce the transition occur from semiconductor to metal in the APNRs. The negative differential resistance (NDR) behavior in the doped APNR system is robust with respect to the doping concentration and edge passivation type. However, their current peak positions and peak-to-valley ratio (PVR) values are correlated with doping concentration and edge passivation type. In particular, for the C, Si-doped APNRs, the low bias NDR behavior with the PVR (10 5 -10 8 ) can be observed when doping concentration is low in the APNRs with the F and H edge passivation. These results may play an important role for the fabrication of future low power consumption nano-electronic devices.

Motility versus fluctuations in mixtures of self-motile and passive agents.

PubMed

Hinz, Denis F; Panchenko, Alexander; Kim, Tae-Yeon; Fried, Eliot

2014-12-07

Many biological systems consist of self-motile and passive agents both of which contribute to overall functionality. However, little is known about the properties of such mixtures. Here we formulate a model for mixtures of self-motile and passive agents and show that the model gives rise to three different dynamical phases: a disordered mesoturbulent phase, a polar flocking phase, and a vortical phase characterized by large-scale counter rotating vortices. We use numerical simulations to construct a phase diagram and compare the statistical properties of the different phases with observed features of self-motile bacterial suspensions. Our findings afford specific insights regarding the interaction of microorganisms and passive particles and provide novel strategic guidance for efficient technological realizations of artificial active matter.

Effect of surface passivation on corrosion resistance and antibacterial properties of Cu-bearing 316L stainless steel

NASA Astrophysics Data System (ADS)

Zhao, Jinlong; Xu, Dake; Shahzad, M. Babar; Kang, Qiang; Sun, Ying; Sun, Ziqing; Zhang, Shuyuan; Ren, Ling; Yang, Chunguang; Yang, Ke

2016-11-01

The resistance for pitting corrosion, passive film stability and antibacterial performance of 316L-Cu SS passivated by nitric acid solution containing certain concentration of copper sulfate, were studied by electrochemical cyclic polarization, electrochemical impedance spectroscopy (EIS) and co-culture with bacteria. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the Cu2+ ions release from 316L-Cu SS surface. XPS analysis proved that the enrichment of CuO, Cr2O3 and Cr(OH)3 on the surface of specimen could simultaneously guarantee a better corrosion resistance and stable antibacterial properties. The biocompatibility evaluation determined by RTCA assay also indicated that the 316L-Cu SS after antibacterial passivation was completely biocompatible.

Filament structure, organization, and dynamics in MreB sheets.

PubMed

Popp, David; Narita, Akihiro; Maeda, Kayo; Fujisawa, Tetsuro; Ghoshdastider, Umesh; Iwasa, Mitsusada; Maéda, Yuichiro; Robinson, Robert C

2010-05-21

In vivo fluorescence microscopy studies of bacterial cells have shown that the bacterial shape-determining protein and actin homolog, MreB, forms cable-like structures that spiral around the periphery of the cell. The molecular structure of these cables has yet to be established. Here we show by electron microscopy that Thermatoga maritime MreB forms complex, several mum long multilayered sheets consisting of diagonally interwoven filaments in the presence of either ATP or GTP. This architecture, in agreement with recent rheological measurements on MreB cables, may have superior mechanical properties and could be an important feature for maintaining bacterial cell shape. MreB polymers within the sheets appear to be single-stranded helical filaments rather than the linear protofilaments found in the MreB crystal structure. Sheet assembly occurs over a wide range of pH, ionic strength, and temperature. Polymerization kinetics are consistent with a cooperative assembly mechanism requiring only two steps: monomer activation followed by elongation. Steady-state TIRF microscopy studies of MreB suggest filament treadmilling while high pressure small angle x-ray scattering measurements indicate that the stability of MreB polymers is similar to that of F-actin filaments. In the presence of ADP or GDP, long, thin cables formed in which MreB was arranged in parallel as linear protofilaments. This suggests that the bacterial cell may exploit various nucleotides to generate different filament structures within cables for specific MreB-based functions.

Comparison of two tension-band fixation materials and techniques in transverse patella fractures: a biomechanical study.

PubMed

Rabalais, R David; Burger, Evalina; Lu, Yun; Mansour, Alfred; Baratta, Richard V

2008-02-01

This study compared the biomechanical properties of 2 tension-band techniques with stainless steel wire and ultra high molecular weight polyethylene (UHMWPE) cable in a patella fracture model. Transverse patella fractures were simulated in 8 cadaver knees and fixated with figure-of-8 and parallel wire configurations in combination with Kirschner wires. Identical configurations were tested with UHMWPE cable. Specimens were mounted to a testing apparatus and the quadriceps was used to extend the knees from 90 degrees to 0 degrees; 4 knees were tested under monotonic loading, and 4 knees were tested under cyclic loading. Under monotonic loading, average fracture gap was 0.50 and 0.57 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.16 and 0.04 mm, respectively, in the parallel wire construct. Under cyclic loading, average fracture gap was 1.45 and 1.66 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.45 and 0.60 mm, respectively, in the parallel wire construct. A statistically significant effect of technique was found, with the parallel wire construct performing better than the figure-of-8 construct in both loading models. There was no effect of material or interaction. In this biomechanical model, parallel wires performed better than the figure-of-8 configuration in both loading regimens, and UHMWPE cable performed similarly to 18-gauge steel wire.

In vitro biomechanical comparison of multistrand cables with conventional cervical stabilization.

PubMed

Weis, J C; Cunningham, B W; Kanayama, M; Parker, L; McAfee, P C

1996-09-15

The biomechanical stability of six different methods of cervical spine stabilization, three using multistrand cables, were evaluated in a bovine model. To quantify and compare the in vitro biomechanical properties of multistrand cables used for posterior cervical wiring to standard cervical fixation techniques. Fixation of the posterior cervical spine with monofilament stainless steel wire is a proven technique for stabilization of the cervical spine. Recently, multistrand braided cables have been used as a substitute for monofilament stainless steel wires. These cables, made of stainless steel, titanium, or polyethylene, are reported to be stronger, more flexible, and fatigue resistant than are monofilament wire based on mechanical testing. However, no in vitro biomechanical studies have been performed testing a standard posterior cervical wiring technique using multistrand cables. Thirty-six fresh frozen cervical calf spines consistent in size and age were mounted and fixed rigidly to isolate the C4-C5 motion segment. Six different reconstruction techniques were evaluated for Rogers' posterior cervical wiring technique using: 1) 20-gauge stainless steel monofilament wire, 2) stainless steel cable, 3) titanium cable, 4) polyethylene cables, 5) anterior locking plate construct with interbody graft, and 6) posterior plate construct. Six cervical spines were included in each group (n = 6), with each specimen statically evaluated under three stability conditions: 1) intact, 2) reconstructed, and 3) postfatigue. The instability model created before the reconstruction consisted of a distractive flexion Stage 3 injury at C4-C5. Nondestructive static biomechanical testing, performed on an material testing machine (MTS 858 Bionix test system, Minneapolis, MN), included axial compression, axial rotation, flexion-extension, and lateral bending. After reconstruction and static analysis, the specimens were fatigued for 1500 cycles and then statically retested. Data analysis included normalization of the reconstructed and postfatigue data to the intact condition. The calculated static parameters included operative functional unit stiffness and range of motion. Posterior cervical reconstruction with stainless steel monofilament wire proved inadequate under fatigue testing. Two of the six specimens failed with fatigue, and this construct permitted the greatest degree of flexion-extension motion after fatigue in comparison with all other constructs (P < 0.05). There were no significant differences in flexural stiffness or range of motion between stainless steel, titanium, or polyethylene cable constructs before or after fatigue testing. The posterior cervical plate constructs were the stiffest constructs under flexion, extension, and lateral bending modes, before and after fatigue testing (P < 0.05). Multistrand cables were superior to monofilament wire with fatigue testing using an in vitro calf cervical spine model. There were no failures or detectable differences in elongation after fatigue testing between the stainless steel, titanium, and polyethylene cables, as shown by the flexion-extension range of motion. The posterior cervical plate construct offered the greatest stability compared with all other constructs.

Evaluation of a buried cable roadside animal detection system.

DOT National Transportation Integrated Search

2015-06-01

Animal-vehicle collisions (AVC) are a concern for departments of transportation as they translate into hundreds of : human fatalities and billions of dollars in property damage each year. A recently published report states that the Virginia : Departm...

Safety of externally stimulated intracranial electrodes during functional MRI at 1.5T.

PubMed

Bhattacharyya, Pallab K; Mullin, Jeffery; Lee, Bryan S; Gonzalez-Martinez, Jorge A; Jones, Stephen E

2017-05-01

Surgical resection of the epileptogenic zone (EZ) is a potential cure for medically refractory focal epilepsy. Proper identification of the EZ is essential for such resection. Synergistic application of functional magnetic resonance imaging (fMRI) simultaneously with stimulation of a single externalized intracranial stereotactic EEG (SEEG) electrode has the potential to improve identification of the EZ. While most EEG-fMRI studies use the electrodes passively to record electrical activity, it is possible to stimulate the brain using the electrodes by connecting them with conducting cables to the stimulation hardware. In this study, we investigated the effect of MRI-induced heating on a single SEEG electrode and its sensitivity to geometry, configuration, and associated connections required for the stimulation. The temperature increase of a single electrode embedded within a gel phantom and connected to an external stimulation system was measured during 1.5T MRI scans using adjacent fluoroptic temperature sensors. A receive-only split-array head coil and a transmit-receive head coil were used for testing. Sequences included a standard localizer, T1-weighted axial fast low-angle shot (FLASH), gradient echo-planar imaging (GE-EPI) axial fMRI, and a high specific absorption rate T2-weighted turbo spin-echo (TSE) axial scan. Variations of the electrode location and connecting cable configuration were tested. No unacceptable heating was observed with the standard sequences used for evaluation of the EZ. Considerable heating (up to 14°C) was observed with the TSE sequence, which is not used clinically. The temperature increase was insignificant (<0.05°C) for electrode contacts closest to the isocenter and connecting cables lying along the isocenter, and varied with configurations of the connecting cable assembly. Simultaneous intracranial electrode stimulation during fMRI using an externalized stimulation system may be safe with strict adherence to settings tested prior to the fMRI. Localizer, FLASH, and GE-EPI fMRI may be safely performed in patients with a single SEEG electrode following the configurations tested in this study, but high SAR TSE scans should not be performed in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Directional Stability of Towed Airplanes

NASA Technical Reports Server (NTRS)

Soehne, W.

1956-01-01

So far, very careful investigations have been made regarding the flight properties, in particular the static and dynamic stability, of engine-propelled aircraft and of untowed gliders. In contrast, almost no investigations exist regarding the stability of airplanes towed by a towline. Thus, the following report will aim at investigating the directional stability of the towed airplane and, particularly, at determining what parameters of the flight attitude and what configuration properties affect the stability. The most important parameters of the flight attitude are the dynamic pressure, the aerodynamic coefficients of the flight attitude, and the climbing angle. Among the configuration properties, the following exert the greatest influence on the stability: the tow-cable length, the tow-cable attachment point, the ratio of the wing loadings of the towing and the towed airplanes, the moments of inertia, and the wing dihedral of the towed airplane. In addition, the size and shape of the towed airplane vertical tail, the vertical tail length, and the fuselage configuration are decisive factors in determining the yawing moment and side force due to sideslip, respectively.

Impact of pregnancy and vaginal delivery on the passive and active mechanics of the rat vagina.

PubMed

Feola, Andrew; Moalli, Pamela; Alperin, Marianna; Duerr, Robbie; Gandley, Robin E; Abramowitch, Steven

2011-01-01

Remodeling of vaginal extracellular matrix and smooth muscle likely plays a critical role in reducing the risk of maternal injury during vaginal delivery by altering the mechanical properties to increase distension and reduce stress. Long-Evans rats were divided into five groups to examine the passive mechanical and active contractile properties throughout pregnancy and postpartum: virgin (n=17), mid-pregnant (Day 14-16, n=12), late-pregnant (Day 20-22, n=14), immediate postpartum (0-2 h after delivery, n=14), and 4 week postpartum (n=15). Longitudinal sections of vaginal tissue were loaded to failure uniaxially for passive mechanical or active contractile properties were examined. For passive mechanics, the tangent modulus decreased 45% by mid-pregnancy and immediately postpartum (p<0.001). The ultimate strain continuously increased up to 43% higher than virgin animals (p=0.007) in the immediate postpartum group. For active mechanics, the maximal contractile force was 36-56% lower through immediate postpartum animals, and was significantly more sensitive to K+ throughout pregnancy and postpartum (p=0.003). The changes observed in the passive and active properties of the rat vagina are consistent with what would be expected from a tissue that is remodeling to maximize its ability to distend at the time of vaginal delivery to facilitate passage of the fetus with minimal injury.

Adsorption of molecular additive onto lead halide perovskite surfaces: A computational study on Lewis base thiophene additive passivation

NASA Astrophysics Data System (ADS)

Zhang, Lei; Yu, Fengxi; Chen, Lihong; Li, Jingfa

2018-06-01

Organic additives, such as the Lewis base thiophene, have been successfully applied to passivate halide perovskite surfaces, improving the stability and properties of perovskite devices based on CH3NH3PbI3. Yet, the detailed nanostructure of the perovskite surface passivated by additives and the mechanisms of such passivation are not well understood. This study presents a nanoscopic view on the interfacial structure of an additive/perovskite interface, consisting of a Lewis base thiophene molecular additive and a lead halide perovskite surface substrate, providing insights on the mechanisms that molecular additives can passivate the halide perovskite surfaces and enhance the perovskite-based device performance. Molecular dynamics study on the interactions between water molecules and the perovskite surfaces passivated by the investigated additive reveal the effectiveness of employing the molecular additives to improve the stability of the halide perovskite materials. The additive/perovskite surface system is further probed via molecular engineering the perovskite surfaces. This study reveals the nanoscopic structure-property relationships of the halide perovskite surface passivated by molecular additives, which helps the fundamental understanding of the surface/interface engineering strategies for the development of halide perovskite based devices.

Comparison of body-powered voluntary opening and voluntary closing prehensor for activities of daily life.

PubMed

Berning, Kelsey; Cohick, Sarah; Johnson, Reva; Miller, Laura Ann; Sensinger, Jonathon W

2014-01-01

Persons with an upper-limb amputation who use a body-powered prosthesis typically control the prehensor through contralateral shoulder movement, which is transmitted through a Bowden cable. Increased cable tension either opens or closes the prehensor; when tension is released, some passive element, such as a spring, returns the prehensor to the default state (closed or open). In this study, we used the Southampton Hand Assessment Procedure to examine functional differences between these two types of prehensors in 29 nondisabled subjects (who used a body-powered bypass prosthesis) and 2 persons with unilateral transradial amputations (who used a conventional body-powered device). We also administered a survey to determine whether subjects preferred one prehensor or the other for specific tasks, with a long-term goal of assessing whether a prehensor that could switch between both modes would be advantageous. We found that using the voluntary closing prehensor was 1.3 s faster (p = 0.02) than using the voluntary opening prehensor, across tasks, and that there was consensus among subjects on which types of tasks they preferred to do with each prehensor type. Twenty-five subjects wanted a device that could switch between the two modes in order to perform particular tasks.

VCSEL-based optical transceiver module for high-speed short-reach interconnect

NASA Astrophysics Data System (ADS)

Yagisawa, Takatoshi; Oku, Hideki; Mori, Tatsuhiro; Tsudome, Rie; Tanaka, Kazuhiro; Daikuhara, Osamu; Komiyama, Takeshi; Ide, Satoshi

2017-02-01

Interconnects have been more important in high-performance computing systems and high-end servers beside its improvements in computing capability. Recently, active optical cables (AOCs) have started being used for this purpose instead of conventionally used copper cables. The AOC enables to extend the transmission distance of the high-speed signals dramatically by its broadband characteristics, however, it tend to increase the cost. In this paper, we report our developed quad small form-factor pluggable (QSFP) AOC utilizing cost-effective optical-module technologies. These are a unique structure using generally used flexible printed circuit (FPC) in combination with an optical waveguide that enables low-cost high-precision assembly with passive alignment, a lens-integrated ferrule that improves productivity by eliminating a polishing process for physical contact of standard PMT connector for the optical waveguide, and an overdrive technology that enables 100 Gb/s (25 Gb/s × 4-channel) operation with low-cost 14 Gb/s vertical-cavity surfaceemitting laser (VCSEL) array. The QSFP AOC demonstrated clear eye opening and error-free operation at 100 Gb/s with high yield rate even though the 14 Gb/s VCSEL was used thanks to the low-coupling loss resulting from the highprecision alignment of optical devices and the over-drive technology.

Mineralization of the Sea Urchin Skeleton

NASA Astrophysics Data System (ADS)

Wilt, F.

2001-12-01

The sea urchin possess a calcareous skeleton composed of over 99% magnesian calcite,an enveloping extracellular matrix, and an occluded protein matrix. The most intensively studied skeletal element is the spicule of the embryo. At the 32 cell stage of development a cohort of 4 cells becomes irrevocably dedicated to spicule formation. At the early gastrula stage the descendants of these founder cells form the primary mesenchyme (PMC). The PMCs fuse to form a multinucleated syncytium connected by cytoplasmic cables, and the calcitic skeleton is formed within these cables. Our primary concern is with the cellular and molecular mechanisms that support the formation of the mineralized spicules. The import of calcium into the PMCs results in appearance of intracellular vesicles containing precipitated calcium, which is neither very stable nor birefringent, and could be amorphous. The precipitated calcium is vectorially secreted into an extracellular space. This space is almost completely enclosed by cytoplasmic strands, and the mineral is encased in an extracellular matrix. Proteins destined for the extracellular matrix, and for inclusion in the spicule, are present in the Golgi membranes and in small intracellular vesicles. These vesicles apparently deliver the matrix proteins to the growing spicule. Our current view is that the matrix molecules are much more than a passive armature, but are actively involved in precipitation, secretion, and organization of the mineral phase.

Preparation of SiO2 Passivation Thin Film for Improved the Organic Light-Emitting Device Life Time

NASA Astrophysics Data System (ADS)

Hong, Jeong Soo; Kim, Sang Mo; Kim, Kyung-Hwan

2011-08-01

To improve the organic light-emitting diode (OLED) lifetime, we prepared a SiO2 thin film for OLED passivation using a facing target sputtering (FTS) system as a function of oxygen gas flow rate and working pressure. The properties of the SiO2 thin film were examined by Fourier transform infrared (FT-IR), photoluminescence (PL) intensity measurement, field emission scanning electron microscopy (FE-SEM), and ultraviolet-visible (UV-vis) spectrometry that As a result, we found that a SiO2 thin film is formed at a 2 sccm oxygen gas flow rate and results the minimum damage to the organic layer is observed at a 1 mTorr working pressure. Also, from the water vapor transmission rate (WVTR), we observed that all of the as-deposited SiO2 thin films showed the ability of blocking moisture. After the properties were evaluated, an optimized SiO2 thin film was applied to OLED passivation. As a result, the property of the OLED fabricated by SiO2 passivation is similar to the OLED fabricated by glass passivation. However, the performance of OLED was degraded by enhancing of SiO2 passivation. This is the organic layer of the device is exposed to plasma for a prolonged period. Therefore, a method of minimizing damage to the organic layer and optimum conditions for what are important.

30 CFR 77.605 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Breaking trailing cable and power cable... OF UNDERGROUND COAL MINES Trailing Cables § 77.605 Breaking trailing cable and power cable connections. Trailing cable and power cable connections between cables and to power sources shall not be made...

30 CFR 77.605 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Breaking trailing cable and power cable... OF UNDERGROUND COAL MINES Trailing Cables § 77.605 Breaking trailing cable and power cable connections. Trailing cable and power cable connections between cables and to power sources shall not be made...

30 CFR 77.605 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Breaking trailing cable and power cable... OF UNDERGROUND COAL MINES Trailing Cables § 77.605 Breaking trailing cable and power cable connections. Trailing cable and power cable connections between cables and to power sources shall not be made...

30 CFR 77.605 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Breaking trailing cable and power cable... OF UNDERGROUND COAL MINES Trailing Cables § 77.605 Breaking trailing cable and power cable connections. Trailing cable and power cable connections between cables and to power sources shall not be made...

30 CFR 77.605 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Breaking trailing cable and power cable... OF UNDERGROUND COAL MINES Trailing Cables § 77.605 Breaking trailing cable and power cable connections. Trailing cable and power cable connections between cables and to power sources shall not be made...

Impedance self-matching ultra-narrow linewidth fiber resonator by use of a tunable π-phase-shifted FBG.

PubMed

Jing, Mingyong; Yu, Bo; Hu, Jianyong; Hou, Huifang; Zhang, Guofeng; Xiao, Liantuan; Jia, Suotang

2017-05-15

In this paper, we present a novel ultra-narrow linewidth fiber resonator formed by a tunable polarization maintaining (PM) π-phase-shifted fiber Bragg grating and a PM uniform fiber Bragg grating with a certain length of PM single mode fiber patch cable between them. Theoretical prediction shows that this resonator has ultra-narrow linewidth resonant peaks and is easy to realize impedance matching. We experimentally obtain 3 MHz narrow linewidth impedance matched resonant peak in a 7.3 m ultra-long passive fiber cavity. The impedance self-matching characteristic of this resonator also makes itself particularly suitable for use in ultra-sensitive sensors, ultra-narrow band rejection optical filters and fiber lasers applications.

Fiberoptics technology and its application to propulsion control systems

NASA Technical Reports Server (NTRS)

Baumbick, R. J.

1983-01-01

Electro-optical systems have many advantages over conventional electrical systems. Among these are optics' insensitivity to electro-magnetic interference, good electrical isolation and the ability to make measurements in highly explosive areas without risk. These advantages promise to help improve the reliability of future aircraft engine control systems which will be entirely electronic digital. To improve the reliability of these systems, especially against lightning strikes, passive, optical, sensors and fiberoptic transmission lines are being considered for use in future engine systems. Also under consideration are actuators which receive their command signals over fiber optic cables. This paper reviews concepts used for optical instrumentation and actuation systems and discusses work being done by NASA Lewis Research Center in this area.

Deep Charging Evaluation of Satellite Power and Communication System Components

NASA Technical Reports Server (NTRS)

Schneider, T. A.; Vaughn, J. A.; Chu, B.; Wong, F.; Gardiner, G.; Wright, K. H.; Phillips, B.

2016-01-01

A set of deep charging tests has been carried out by NASA's Marshall Space Flight Center on subscale flight-like samples developed by Space Systems/Loral, LLC. The samples, which included solar array wire coupons, a photovoltaic cell coupon, and a coaxial microwave transmission cable, were placed in passive and active (powered) circuit configurations and exposed to electron radiation. The energy of the electron radiation was chosen to deeply penetrate insulating (dielectric) materials on each sample. Each circuit configuration was monitored to determine if potentially damaging electrostatic discharge events (arcs) were developed on the coupon as a result of deep charging. The motivation for the test, along with charging levels, experimental setup, sample details, and results will be discussed.

Studies of a full-scale mechanical prototype line for the ANTARES neutrino telescope and tests of a prototype instrument for deep-sea acoustic measurements

NASA Astrophysics Data System (ADS)

Ageron, M.; Aguilar, J. A.; Albert, A.; Ameli, F.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardellier-Desages, F.; Aslanides, E.; Aubert, J.-J.; Auer, R.; Barbarito, E.; Basa, S.; Battaglieri, M.; Bazzotti, M.; Becherini, Y.; Béthoux, N.; Beltramelli, J.; Bertin, V.; Bigi, A.; Billault, M.; Blaes, R.; de Botton, N.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Burgio, G. F.; Busto, J.; Cafagna, F.; Caillat, L.; Calzas, A.; Capone, A.; Caponetto, L.; Carmona, E.; Carr, J.; Castel, D.; Castorina, E.; Cavasinni, V.; Cecchini, S.; Ceres, A.; Charvis, P.; Chauchot, P.; Chiarusi, T.; Circella, M.; Coail, J.-Y.; Colnard, C.; Compére, C.; Coniglione, R.; Cottini, N.; Coyle, P.; Cuneo, S.; Cussatlegras, A.-S.; Damy, G.; van Dantzig, R.; Debonis, G.; de Marzo, C.; de Vita, R.; Dekeyser, I.; Delagnes, E.; Denans, D.; Deschamps, A.; Dessa, J.-X.; Destelle, J.-J.; Dinkespieler, B.; Distefano, C.; Donzaud, C.; Drogou, J.-F.; Druillole, F.; Durand, D.; Ernenwein, J.-P.; Escoffier, S.; Falchini, E.; Favard, S.; Fehr, F.; Feinstein, F.; Fiorello, C.; Flaminio, V.; Fratini, K.; Fuda, J.-L.; Galeotti, S.; Gallone, J.-M.; Giacomelli, G.; Girard, N.; Gojak, C.; Goret, Ph.; Graf, K.; Guilloux, F.; Hallewell, G.; Harakeh, M. N.; Hartmann, B.; Heijboer, A.; Heine, E.; Hello, Y.; Hernández-Rey, J. J.; Hößl, J.; Hoffman, C.; Hogenbirk, J.; Hubbard, J. R.; Jaquet, M.; Jaspers, M.; de Jong, M.; Jouvenot, F.; Kalantar-Nayestanaki, N.; Kappes, A.; Karg, T.; Katz, U.; Keller, P.; Kneib, J. P.; Kok, E.; Kok, H.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kretschmer, W.; Kruijer, A.; Kuch, S.; Lagier, P.; Lahmann, R.; Lamanna, G.; Lamare, P.; Lambard, G.; Languillat, J. C.; Laschinsky, H.; Lavalle, J.; Le Guen, Y.; Le Provost, H.; Le van Suu, A.; Lefévre, D.; Legou, T.; Lelaizant, G.; Lim, G.; Lo Presti, D.; Loaec, G.; Loehner, H.; Loucatos, S.; Louis, F.; Lucarelli, F.; Lyashuk, V.; Mangano, S.; Marcelin, M.; Margiotta, A.; Masullo, R.; Mazéas, F.; Mazure, A.; Megna, R.; Melissas, M.; Migneco, E.; Mongelli, M.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Musumeci, M.; Naumann, C.; Naumann-Godo, M.; Niess, V.; Noble, A.; Olivetto, C.; Ostasch, R.; Palanque-Delabrouille, N.; Payre, P.; Peek, H. Z.; Perez, A.; Petta, C.; Piattelli, P.; Pillet, R.; Pineau, J.-P.; Poinsignon, J.; Popa, V.; Pradier, T.; Racca, C.; Randazzo, N.; van Randwijk, J.; Real, D.; Regnier, M.; van Rens, B.; Réthoré, F.; Rewiersma, P.; Riccobene, G.; Rigaud, V.; Ripani, M.; Roca, V.; Roda, C.; Rolin, J. F.; Rostovtsev, A.; Roux, J.; Ruppi, M.; Russo, G. V.; Rusydi, G.; Salesa, F.; Salomon, K.; Sapienza, P.; Schmitt, F.; Schuller, J.-P.; Shanidze, R.; Sokalski, I.; Spona, T.; Spurio, M.; van der Steenhoven, G.; Stolarczyk, T.; Streeb, K.; Sulak, L.; Taiuti, M.; Tamburini, C.; Tao, C.; Tasca, L.; Terreni, G.; Urbano, F.; Valdy, P.; Valente, V.; Vallage, B.; Vaudaine, G.; Venekamp, G.; Verlaat, B.; Vernin, P.; van Wijk, R.; Wijnker, G.; Wobbe, G.; de Wolf, E.; Yao, A.-F.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zúñiga, J.

2007-11-01

A full-scale mechanical prototype line was deployed to a depth of 2500 m to test the leak tightness of the electronics containers and the pressure-resistant properties of an electromechanical cable under evaluation for use in the ANTARES deep-sea neutrino telescope. During a month-long immersion study, line parameter data were taken using miniature autonomous data loggers and shore-based optical time domain reflectometry. Details of the mechanical prototype line, the electromechanical cable and data acquisition are presented. Data taken during the immersion study revealed deficiencies in the pressure resistance of the electromechanical cable terminations at the entry points to the electronics containers. The improvements to the termination, which have been integrated into subsequent detection lines, are discussed. The line also allowed deep-sea acoustic measurements with a prototype hydrophone system. The technical setup of this system is described, and the first results of the data analysis are presented.

Locating illicit connections in storm water sewers using fiber-optic distributed temperature sensing.

PubMed

Hoes, O A C; Schilperoort, R P S; Luxemburg, W M J; Clemens, F H L R; van de Giesen, N C

2009-12-01

A newly developed technique using distributed temperature sensing (DTS) has been developed to find illicit household sewage connections to storm water systems in the Netherlands. DTS allows for the accurate measurement of temperature along a fiber-optic cable, with high spatial (2m) and temporal (30s) resolution. We inserted a fiber-optic cable of 1300m in two storm water drains. At certain locations, significant temperature differences with an intermittent character were measured, indicating inflow of water that was not storm water. In all cases, we found that foul water from households or companies entered the storm water system through an illicit sewage connection. The method of using temperature differences for illicit connection detection in storm water networks is discussed. The technique of using fiber-optic cables for distributed temperature sensing is explained in detail. The DTS method is a reliable, inexpensive and practically feasible method to detect illicit connections to storm water systems, which does not require access to private property.

A simple method for characterizing passive and active neuronal properties: application to striatal neurons.

PubMed

Lepora, Nathan F; Blomeley, Craig P; Hoyland, Darren; Bracci, Enrico; Overton, Paul G; Gurney, Kevin

2011-11-01

The study of active and passive neuronal dynamics usually relies on a sophisticated array of electrophysiological, staining and pharmacological techniques. We describe here a simple complementary method that recovers many findings of these more complex methods but relies only on a basic patch-clamp recording approach. Somatic short and long current pulses were applied in vitro to striatal medium spiny (MS) and fast spiking (FS) neurons from juvenile rats. The passive dynamics were quantified by fitting two-compartment models to the short current pulse data. Lumped conductances for the active dynamics were then found by compensating this fitted passive dynamics within the current-voltage relationship from the long current pulse data. These estimated passive and active properties were consistent with previous more complex estimations of the neuron properties, supporting the approach. Relationships within the MS and FS neuron types were also evident, including a graduation of MS neuron properties consistent with recent findings about D1 and D2 dopamine receptor expression. Application of the method to simulated neuron data supported the hypothesis that it gives reasonable estimates of membrane properties and gross morphology. Therefore detailed information about the biophysics can be gained from this simple approach, which is useful for both classification of neuron type and biophysical modelling. Furthermore, because these methods rely upon no manipulations to the cell other than patch clamping, they are ideally suited to in vivo electrophysiology. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Chemical passivation as a method of improving the electrochemical corrosion resistance of Co-Cr-based dental alloy.

PubMed

Rylska, Dorota; Sokołowski, Grzegorz; Sokołowski, Jerzy; Łukomska-Szymańska, Monika

2017-01-01

The purpose of the study was to evaluate corrosion resistance of Wirobond C® alloy after chemical passivation treatment. The alloy surface undergone chemical passivation treatment in four different media. Corrosion studies were carried out by means of electrochemical methods in saline solution. Corrosion effects were determined using SEM. The greatest increase in the alloy polarization resistance was observed for passive layer produced in Na2SO4 solution with graphite. The same layer caused the highest increase in corrosion current. Generally speaking, the alloy passivation in Na2SO4 solution with graphite caused a substantial improvement of the corrosion resistance. The sample after passivation in Na2SO4 solution without graphite, contrary to others, lost its protective properties along with successive anodic polarization cycles. The alloy passivation in Na3PO4 solution with graphite was the only one that caused a decrease in the alloy corrosion properties. The SEM studies of all samples after chemical passivation revealed no pit corrosion - in contrast to the sample without any modification. Every successive polarization cycle in anodic direction of pure Wirobond C® alloy enhances corrosion resistance shifting corrosion potential in the positive direction and decreasing corrosion current value. The chemical passivation in solutions with low pH values decreases susceptibility to electrochemical corrosion of Co-Cr dental alloy. The best protection against corrosion was obtained after chemical passivation of Wirobond C® in Na2SO4 solution with graphite. Passivation with Na2SO4 in solution of high pH does not cause an increase in corrosion resistance of WIROBOND C. Passivation process increases alloy resistance to pit corrosion.

A deflectable guiding catheter for real-time MRI-guided interventions.

PubMed

Bell, Jamie A; Saikus, Christina E; Ratnayaka, Kanishka; Wu, Vincent; Sonmez, Merdim; Faranesh, Anthony Z; Colyer, Jessica H; Lederman, Robert J; Kocaturk, Ozgur

2012-04-01

To design a deflectable guiding catheter that omits long metallic components yet preserves mechanical properties to facilitate therapeutic interventional MRI procedures. The catheter shaft incorporated Kevlar braiding. A 180° deflection was attained with a 5-cm nitinol slotted tube, a nitinol spring, and a Kevlar pull string. We tested three designs: passive, passive incorporating an inductively coupled coil, and active receiver. We characterized mechanical properties, MRI properties, RF induced heating, and in vivo performance in swine. Torque and tip deflection force were satisfactory. Representative procedures included hepatic and azygos vein access, laser cardiac septostomy, and atrial septal defect crossing. Visualization was best in the active configuration, delineating profile and tip orientation. The passive configuration could be used in tandem with an active guidewire to overcome its limited conspicuity. There was no RF-induced heating in all configurations under expected use conditions in vitro and in vivo. Kevlar and short nitinol component substitutions preserved mechanical properties. The active design offered the best visibility and usability but reintroduced metal conductors. We describe versatile deflectable guiding catheters with a 0.057" lumen for interventional MRI catheterization. Implementations are feasible using active, inductive, and passive visualization strategies to suit application requirements. Copyright © 2011 Wiley Periodicals, Inc.

Very Low Frequency Breakdown Properties of Electrical Insulation Materials at Cryogenic Temperatures

NASA Astrophysics Data System (ADS)

Sauers, I.; Tuncer, E.; Polizos, G.; James, D. R.; Ellis, A. R.; Pace, M. O.

2010-04-01

For long cables or equipment with large capacitance it is not always possible to conduct high voltage withstand tests at 60 Hz due to limitations in charging currents of the power supply. Very low frequency (typically at a frequency of 0.1 Hz) has been used for conventional cables as a way of getting around the charging current limitation. For superconducting grid applications the same issues apply. However there is very little data at cryogenic temperatures on how materials perform at low frequency compared to 60 Hz and whether higher voltages should be applied when performing a high voltage acceptability test. Various materials including G10 (fiberglass reinforced plastic or FRP), Cryoflex™ (a tape insulation used in some high temperature superconducting cables), kapton (commonly used polyimide), polycarbonate, and polyetherimide, and in liquid nitrogen alone have been tested using a step method for frequencies of 60 Hz, 0.1 Hz, and dc. The dwell time at each step was chosen so that the aging factor would be the same in both the 60 Hz and 0.1 Hz tests. The data indicated that, while there is a small frequency dependence for liquid nitrogen, there are significant differences for the solid materials studied. Breakdown data for these materials and for model cables will be shown and discussed.

Plasmonic nanorod arrays of a two-segment dimer and a coaxial cable with 1 nm gap for large field confinement and enhancement.

PubMed

Cheng, Zi-Qiang; Nan, Fan; Yang, Da-Jie; Zhong, Yu-Ting; Ma, Liang; Hao, Zhong-Hua; Zhou, Li; Wang, Qu-Quan

2015-01-28

Seeking plasmonic nanostructures with large field confinement and enhancement is significant for photonic and electronic nanodevices with high sensitivity, reproducibility, and tunability. Here, we report the synthesis of plasmonic arrays composed of two-segment dimer nanorods and coaxial cable nanorods with ∼1 nm gap insulated by a self-assembled Raman molecule monolayer. The gap-induced plasmon coupling generates an intense field in the gap region of the dimer junction and the cable interlayer. As a result, the longitudinal plasmon resonance of nanorod arrays with high tunability is obviously enhanced. Most interestingly, the field enhancement of dimer nanorod arrays can be tuned by the length ratio L1/L2 of the two segments, and the maximal enhancement appears at L1/L2 = 1. In that case, the two-photon luminescence (TPL) of dimer nanorod arrays and the Raman intensity in the dimer junction is enhanced by 27 and 30 times, respectively, under resonant excitation. In the same way, the Raman intensity in the gap region is enhanced 16 times for the coaxial cable nanorod arrays. The plasmonic nanorod arrays synthesized by the facile method, having tunable plasmon properties and large field enhancement, indicate an attractive pathway to the photonic nanodevices.

Summary Report of Cable Aging and Performance Data for Fiscal Year 2014.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Celina, Mathias C.; Celina, Mathias C.; Redline, Erica Marie

2014-09-01

As part of the Light Water Reactor Sustainability Program, science - based engineering approaches were employed to address cable degradation behavior under a range of exposure environments. Experiments were conducted with the goal to provide best guidance for aged material states, remaining life and expected performance under specific conditions for a range of cable materials. Generic engineering tests , which focus on rapid accelerated aging and tensile elongation , were combined with complementar y methods from polymer degradation science. Sandia's approach, building on previous years' efforts, enabled the generation of some of the necessary data supporting the development of improvedmore » lifetime predictions models, which incorporate known material b ehaviors and feedback from field - returned 'aged' cable materials. Oxidation rate measurements have provided access to material behavior under low dose rate thermal conditions, where slow degradation is not apparent in mechanical property changes. Such da ta have shown aging kinetics consistent with established radiati on - thermal degradation models. ACKNOWLEDGEMENTS We gratefully acknowledge ongoing technical support at the LICA facility and extensive sample handling provided by Maryla Wasiolek and Don Hans on. Sam Durbin and Patrick Mattie are recognized for valuable guidance throughout the year and assistance in the preparation of the final report. Doug Brunson is appreciated for sample analysis, compilation and plotting of experimental data.« less

Critical current degradation behaviour of GdBCO CC tapes in pure torsion and combined tension-torsion modes

NASA Astrophysics Data System (ADS)

Gorospe, Alking; Bautista, Zhierwinjay; Shin, Hyung-Seop

2016-10-01

Coated conductor (CC) tapes utilized in high-current-density superconducting cables are commonly subjected to different loading modes, primarily torsion and tension especially in the case of twisted stacked-tape cable. Torsion load can occur due to twisting along the length or when winding the CC tapes around a former, while tension load can occur due to pre-tension when coiled and as a hoop stress when the coil is energized. In this study, electromechanical properties of single CC tapes under torsion load were investigated using a new test apparatus. The results could provide basic information for cable designers to fully characterize stacked cables. Copper-electroplated and brass-laminated CC tapes fabricated with different deposition techniques were subjected to pure torsion and combined tension-torsion loading. The critical current, I c degradation behaviours of CC tapes under torsional deformation were examined. Also, the effect of further external lamination on the I c degradation behaviour of the CC tapes under such loading conditions was investigated. In the case of the combined tension-torsion test, short samples were subjected to twist pitches of 200 mm and 100 mm. Critical parameters including reversible axial stress and strain in such twist pitch conditions were also investigated.

Impact of hydrodynamics on effective interactions in suspensions of active and passive matter.

PubMed

Krafnick, Ryan C; García, Angel E

2015-02-01

Passive particles exhibit unique properties when immersed in an active bath of self-propelling entities. In particular, an effective attraction can appear between particles that repel each other when in a passive solution. Here we numerically study the effect of hydrodynamics on an active-passive hybrid system, where we observe qualitative differences as compared to simulations with excluded volume effects alone. The results shed light on an existing discrepancy in pair lifetimes between simulation and experiment, due to the hydrodynamically enhanced stability of coupled passive particles.

Passive stiffness of rat skeletal muscle undernourished during fetal development

PubMed Central

Toscano, Ana Elisa; Ferraz, Karla Mônica; de Castro, Raul Manhães; Canon, Francis

2010-01-01

OBJECTIVES: The aim of the study was to investigate the effect of fetal undernutrition on the passive mechanical properties of skeletal muscle of weaned and young adult rats. INTRODUCTION: A poor nutrition supply during fetal development affects physiological functions of the fetus. From a mechanical point of view, skeletal muscle can be also characterized by its resistance to passive stretch. METHODS: Male Wistar rats were divided into two groups according to their mother's diet during pregnancy: a control group (mothers fed a 17% protein diet) and an isocaloric low‐protein group (mothers fed a 7.8% protein diet). At birth, all mothers received a standardized meal ad libitum. At the age of 25 and 90 days, the soleus muscle and extensor digitorum longus (EDL) muscles were removed in order to test the passive mechanical properties. A first mechanical test consisted of an incremental stepwise extension test using fast velocity stretching (500 mm/s) enabling us to measure, for each extension stepwise, the dynamic stress (σd) and the steady stress (σs). A second test consisted of a slow velocity stretch in order to calculate normalized stiffness and tangent modulus from the stress–strain relationship. RESULTS: The results for the mechanical properties showed an important increase in passive stiffness in both the soleus and EDL muscles in weaned rat. In contrast, no modification was observed in young adult rats. CONCLUSIONS: The increase in passive stiffness in skeletal muscle of weaned rat submitted to intrauterine undernutrition it is most likely due to changes in muscle passive stiffness. PMID:21340228

Effects of Postmortem Freezing on Passive Properties of Rabbit Extensor Digtorum Longus Muscle Tendon Complex

DTIC Science & Technology

1993-06-14

AD-A266 429 INSTITUTE REPORT NO. 483 Effects of Postmortem Freezing on Passive Properties of Rabbit Extensor Digtorum Longus Muscle Tendon Complex D...Extensor Digtorum Longus Muscle Tendon Complex -- Paul H. Leitschuh, Tammy J. Doherty, Dean C. Taylor, Daniel E. Brooks, John B. Ryan This document has...ABSTRACT The tensile properties of the extensor digitorum longus muscle tendon unit (EDL MTU) were studied in 16 white male New Zealand rabbits in both

Modeling of Passive Forces of Machine Tool Covers

NASA Astrophysics Data System (ADS)

Kolar, Petr; Hudec, Jan; Sulitka, Matej

The passive forces acting against the drive force are phenomena that influence dynamical properties and precision of linear axes equipped with feed drives. Covers are one of important sources of passive forces in machine tools. The paper describes virtual evaluation of cover passive forces using the cover complex model. The model is able to compute interaction between flexible cover segments and sealing wiper. The result is deformation of cover segments and wipers which is used together with measured friction coefficient for computation of cover total passive force. This resulting passive force is dependent on cover position. Comparison of computational results and measurement on the real cover is presented in the paper.

30 CFR 77.601 - Trailing cables or portable cables; temporary splices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Trailing cables or portable cables; temporary... OF UNDERGROUND COAL MINES Trailing Cables § 77.601 Trailing cables or portable cables; temporary splices. Temporary splices in trailing cables or portable cables shall be made in a workmanlike manner and...

Laminated NbTi-on-Kapton Microstrip Cables for Flexible Sub-Kelvin RF Electronics

NASA Astrophysics Data System (ADS)

Walter, Alex B.; Bockstiegel, Clinton; Mazin, Benjamin A.; Daal, Miguel

2017-11-01

Large arrays of superconducting devices such as microwave kinetic inductance detectors require high density interconnects from higher temperatures with minimal heat load, low loss, and negligible crosstalk capable of carrying large and overlapping bandwidth signals. We report the fabrication of superconducting 53 wt% Nb-47 wt% Ti (Nb-47Ti) microstrip transmission lines laminated onto flexible polyimide substrates with lengths up to 40 cm and up to ten traces. The 50 Ω traces terminate in G3PO coaxial push-on connectors. We found transmission losses of 2.5 dB and a nearest-neighbor forward crosstalk of -25 dB at 8 GHz on a typical 5 trace, 1.8-cm-wide, 0.198-mm-thick, 22-cm-long flex cable at 30 mK. A simple two-port analytical model and subsequent Sonnet simulations indicate that this loss is mainly due to a complex impedance mismatch from wirebonds at the end connector without which the insertion loss would be < 2.7 dB/m. This is about six times worse than the transmission measured in Coax Company, Ltd.'s smallest ( 0.86 mm) Nb-47Ti coaxial cables, possibly from differences in the low temperature loss properties of polyimide laminates versus PTFE or from unaccounted resistive losses in the copper adapter coaxes of our tested device. Heat flow calculations from literature data show that the 0.198-mm-thick flex cables tested have roughly equivalent thermal conductance per trace below 4 K compared to the 0.86 mm Nb-47Ti coaxial cables.

Understanding the rates of nonpolar organic chemical accumulation into passive samplers deployed in the environment: Guidance for passive sampler deployments.

PubMed

Apell, Jennifer N; Tcaciuc, A Patricia; Gschwend, Philip M

2016-07-01

Polymeric passive samplers have become a common method for estimating freely dissolved concentrations in environmental media. However, this approach has not yet been adopted by investigators conducting remedial investigations of contaminated environmental sites. Successful adoption of this sampling methodology relies on an understanding of how passive samplers accumulate chemical mass as well as developing guidance for the design and deployment of passive samplers. Herein, we outline the development of a simple mathematical relationship of the environmental, polymer, and chemical properties that control the uptake rate. This relationship, called a timescale, is then used to illustrate how each property controls the rate of equilibration in samplers deployed in the water or in the sediment. Guidance is also given on how to use the timescales to select an appropriate polymer, deployment time, and suite of performance reference compounds. Integr Environ Assess Manag 2016;12:486-492. © 2015 SETAC. © 2015 SETAC.

The influence of the PCF scattering on the electrical properties of the AlGaN/AlN/GaN HEMTs after the Si3N4 surface passivation

NASA Astrophysics Data System (ADS)

Fu, Chen; Lin, Zhaojun; Cui, Peng; Lv, Yuanjie; Zhou, Yang; Dai, Gang; Luan, Chongbiao; Liu, Huan; Cheng, Aijie

2018-04-01

In this paper, the detailed device characteristics were investigated both before and after the Si3N4 passivation grown by plasma-enhanced chemical vapor deposition (PECVD). Better transport properties have been observed for the passivated devices compared with the same ones before passivation. The strain variation and the influence of the scattering mechanisms were analyzed and studied. The calculated results show that the non-uniform distribution of the additional polarization charges at the AlGaN/AlN/GaN interfaces has been weakened by the deposition of the Si3N4 layer. The numerical rise of the two-dimensional electron gas (2DEG) electron mobility and the decrease of the measured R on- A values were in a good consistency, and the weakening of the polarization Coulomb field (PCF) scattering after the passivation process is considered to be the main cause of these phenomena.

Acoustic explorations of the upper ocean boundary layer

NASA Astrophysics Data System (ADS)

Vagle, Svein

2005-04-01

The upper ocean boundary layer is an important but difficult to probe part of the ocean. A better understanding of small scale processes at the air-sea interface, including the vertical transfer of gases, heat, mass and momentum, are crucial to improving our understanding of the coupling between atmosphere and ocean. Also, this part of the ocean contains a significant part of the total biomass at all trophic levels and is therefore of great interest to researchers in a range of different fields. Innovative measurement plays a critical role in developing our understanding of the processes involved in the boundary layer, and the availability of low-cost, compact, digital signal processors and sonar technology in self-contained and cabled configurations has led to a number of exciting developments. This talk summarizes some recent explorations of this dynamic boundary layer using both active and passive acoustics. The resonant behavior of upper ocean bubbles combined with single and multi-frequency broad band active and passive devices are now giving us invaluable information on air-sea gas transfer, estimation of biological production, marine mammal behavior, wind speed and precipitation, surface and internal waves, turbulence, and acoustic communication in the surf zone.

Reliability and Characterization of High Voltage Power Capacitors

DTIC Science & Technology

2014-03-01

Cable The HVPS cable is a specialized coaxial cable that utilizes a high voltage bayonet connector. The cable itself has a voltage rating in excess...the( LabVIEW(program( GPIB( CABLE ( HVPS( HVPS( COAXIAL ( CABLE ( BNC( COAXIAL ( CABLE ( BNC( COAXIAL ( CABLE ( CAPACITOR(‘C’(DATA( CAPACITOR(‘A’(DATA( Circuit...16   F.   CABLES AND CONNECTORS ...................................................................16

Mechanical Properties of the Plantarflexor Musculotendinous Unit during Passive Dorsiflexion in Children with Cerebral Palsy Compared with Typically Developing Children

ERIC Educational Resources Information Center

Alhusaini, Adel A. A.; Crosbie, Jack; Shepherd, Roberta B.; Dean, Catherine M.; Scheinberg, Adam

2010-01-01

Aim: To examine the passive length-tension relations in the myotendinous components of the plantarflexor muscles of children with and without cerebral palsy (CP) under conditions excluding reflex muscle contraction. Method: A cross-sectional, non-interventional study was conducted in a hospital outpatient clinic. Passive torque-angle…

Effect of pH on Semiconducting Property of Passive Film Formed on Ultra-High-Strength Corrosion-Resistant Steel in Sulfuric Acid Solution

NASA Astrophysics Data System (ADS)

Sun, Min; Xiao, Kui; Dong, Chaofang; Li, Xiaogang; Zhong, Ping

2013-10-01

Because Cr9Ni5MoCo14 is a new ultra-high-strength corrosion-resistant steel, it is important to study its corrosion behavior in sulfuric acid solution, which is used to simulate the aggressive environment. The effect of pH on the electrochemical and semiconducting properties of passive films formed on ultra-high-strength corrosion-resistant steel in sulfuric acid solution was investigated by means of the potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and X-ray photoelectron spectroscopy (XPS). The results indicated that Cr9Ni5MoCo14 steel showed a passive state in acid solutions. The corrosion behavior of this Cr9Ni5MoCo14 alloy was influenced by the passive film formed on the surface, including thickness, stability, and partitioning of elements of the passive film. The passive current density decreases with increasing pH, and the corrosion resistance was enhanced by the increasing thickness and depletion of the defects within the passive film. Moreover, an enrichment of chromium (primarily the oxides of Cr) and depletion of iron in the passive film led to improved corrosion resistance. These results can provide a theoretical basis for use of this alloy and further development of ultra-high-strength corrosion-resistant steel in today's society.

Passive stiffness of the gastrocnemius muscle in athletes with spastic hemiplegic cerebral palsy.

PubMed

Hussain, A W; Onambele, G L; Williams, A G; Morse, C I

2013-09-01

The passive properties of the muscle-tendon unit are regularly assessed in individuals with cerebral palsy (CP). However, no information is available on the passive properties of adult muscle, and whether any differences exist between the paretic and control muscles. Eleven ambulant male athletes with spastic hemiplegic CP (21.2 ± 3.0 years) and controls without neurological impairment (age = 21.8 ± 2.2 years) completed two and one passive stretch session, respectively. During each session, the ankle was passively dorsiflexed until end range of motion (ROM), whilst recording passive ankle angle, torque and gastrocnemius medialis (GM) myotendinous junction (MTJ) displacement. In addition, GM cross-sectional area (CSA) and length were measured. Subsequently, in vivo stress and strain were determined to calculate elastic modulus. Passive stiffness, MTJ displacement and ROM of the paretic GM were not different from the control muscles. However, the elastic modulus of the paretic GM was two times stiffer than the control GM muscles. In conclusion, athletes with CP exhibit absolute passive muscle stiffness similar to the controls; however, the elastic modulus of the CP muscle was significantly greater. Therefore, throughout the same ROM a smaller GM CSA in CP athletes has to dissipate larger relative torque compared to the control muscles, consequently causing the muscle to elongate to the same extent as the non-paretic muscle under stretch.

Modeling vibration response and damping of cables and cabled structures

NASA Astrophysics Data System (ADS)

Spak, Kaitlin S.; Agnes, Gregory S.; Inman, Daniel J.

2015-02-01

In an effort to model the vibration response of cabled structures, the distributed transfer function method is developed to model cables and a simple cabled structure. The model includes shear effects, tension, and hysteretic damping for modeling of helical stranded cables, and includes a method for modeling cable attachment points using both linear and rotational damping and stiffness. The damped cable model shows agreement with experimental data for four types of stranded cables, and the damped cabled beam model shows agreement with experimental data for the cables attached to a beam structure, as well as improvement over the distributed mass method for cabled structure modeling.

30 CFR 75.607 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Breaking trailing cable and power cable....607 Breaking trailing cable and power cable connections. [Statutory Provisions] Trailing cable and power cable connections to junction boxes shall not be made or broken under load. ...

30 CFR 75.607 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Breaking trailing cable and power cable....607 Breaking trailing cable and power cable connections. [Statutory Provisions] Trailing cable and power cable connections to junction boxes shall not be made or broken under load. ...

30 CFR 75.607 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Breaking trailing cable and power cable....607 Breaking trailing cable and power cable connections. [Statutory Provisions] Trailing cable and power cable connections to junction boxes shall not be made or broken under load. ...

30 CFR 75.607 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Breaking trailing cable and power cable....607 Breaking trailing cable and power cable connections. [Statutory Provisions] Trailing cable and power cable connections to junction boxes shall not be made or broken under load. ...

A model of activity-dependent changes in dendritic spine density and spine structure.

PubMed

Crook, S M; Dur-E-Ahmad, M; Baer, S M

2007-10-01

Recent evidence indicates that the morphology and density of dendritic spines are regulated during synaptic plasticity. See, for instance, a review by Hayashi and Majewska [9]. In this work, we extend previous modeling studies [27] by combining a model for activity-dependent spine density with one for calcium-mediated spine stem restructuring. The model is based on the standard dimensionless cable equation, which represents the change in the membrane potential in a passive dendrite. Additional equations characterize the change in spine density along the dendrite, the current balance equation for an individual spine head, the change in calcium concentration in the spine head, and the dynamics of spine stem resistance. We use computational studies to investigate the changes in spine density and structure for differing synaptic inputs and demonstrate the effects of these changes on the input-output properties of the dendritic branch. Moderate amounts of high-frequency synaptic activation to dendritic spines result in an increase in spine stem resistance that is correlated with spine stem elongation. In addition, the spine density increases both inside and outside the input region. The model is formulated so that this long-term potentiation-inducing stimulus eventually leads to structural stability. In contrast, a prolonged low-frequency stimulation paradigm that would typically induce long-term depression results in a decrease in stem resistance (correlated with stem shortening) and an eventual decrease in spine density.

Theory of the Maxwell pressure tensor and the tension in a water bridge.

PubMed

Widom, A; Swain, J; Silverberg, J; Sivasubramanian, S; Srivastava, Y N

2009-07-01

A water bridge refers to an experimental "flexible cable" made up of pure de-ionized water, which can hang across two supports maintained with a sufficiently large voltage difference. The resulting electric fields within the de-ionized water flexible cable maintain a tension that sustains the water against the downward force of gravity. A detailed calculation of the water bridge tension will be provided in terms of the Maxwell pressure tensor in a dielectric fluid medium. General properties of the dielectric liquid pressure tensor are discussed along with unusual features of dielectric fluid Bernoulli flows in an electric field. The "frictionless" Bernoulli flow is closely analogous to that of a superfluid.

30 CFR 75.607 - Breaking trailing cable and power cable connections.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Breaking trailing cable and power cable... LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Trailing Cables § 75.607 Breaking trailing cable and power cable connections. [Statutory Provisions] Trailing cable and...

The analysis of cable forces based on natural frequency

NASA Astrophysics Data System (ADS)

Suangga, Made; Hidayat, Irpan; Juliastuti; Bontan, Darwin Julius

2017-12-01

A cable is a flexible structural member that is effective at resisting tensile forces. Cables are used in a variety of structures that employ their unique characteristics to create efficient design tension members. The condition of the cable forces in the cable supported structure is an important indication of judging whether the structure is in good condition. Several methods have been developed to measure on site cable forces. Vibration technique using correlation between natural frequency and cable forces is a simple method to determine in situ cable forces, however the method need accurate information on the boundary condition, cable mass, and cable length. The natural frequency of the cable is determined using FFT (Fast Fourier Transform) Technique to the acceleration record of the cable. Based on the natural frequency obtained, the cable forces then can be determine by analytical or by finite element program. This research is focus on the vibration techniques to determine the cable forces, to understand the physical parameter effect of the cable and also modelling techniques to the natural frequency and cable forces.

PREFACE: Focus section on superconducting power systems Focus section on superconducting power systems

NASA Astrophysics Data System (ADS)

Cardwell, D. A.; Amemiya, N.; Fair, R.

2012-01-01

This focus section of Superconductor Science and Technology looks at the properties, technology and applications of (RE)BCO and MgB2 based superconductors for power engineering systems. Both bulk and conductor forms of material are addressed, including elements of materials fabrication and processing, and the measurement of their applied properties for various levels of system application. The areas of research include ac losses in type II materials in power devices, cables and coated conductors, the development of high current dc cables and the application of superconductors in levitation devices, motors and fault current limiters. This focus section presents a broad cross-section of contemporary issues, that represent state-of-the-art for power applications of superconductors, and highlights the areas that require further development if commercial applications of these rapidly emerging materials are to be realised. It contains papers from some of the major groups in the field, including contributions from Europe, the USA and Japan, and describes devices that are relatively close to market.

Morphology and crystalline-phase-dependent electrical insulating properties in tailored polypropylene for HVDC cables

NASA Astrophysics Data System (ADS)

Zha, Jun-Wei; Yan, Hong-Da; Li, Wei-Kang; Dang, Zhi-Min

2016-11-01

Polypropylene (PP) has become one promising material to potentially replace the cross-link polyethylene used for high voltage direct current cables. Besides the isotactic polypropylene, the block polypropylene (b-PP) and random polypropylene (r-PP) can be synthesized through the copolymerization of ethylene and propylene molecules. In this letter, the effect of morphology and crystalline phases on the insulating electrical properties of PP was investigated. It was found that the introduction of polyethylene monomer resulted in the formation of β and γ phases in b-PP and r-PP. The results from the characteristic trap energy levels indicated that the β and γ phases could induce deep electron traps which enable to capture the carriers. And the space charge accumulation was obviously suppressed. Besides, the decreased electrical conductivity was observed in b-PP and r-PP. It is attributed to the existence of deep traps which can effectively reduce the carrier mobility and density in materials.

Underwater spark discharge with long transmission line for cleaning horizontal wells

NASA Astrophysics Data System (ADS)

Lee, Kern; Chung, Kyoung-Jae; Hwang, Y. S.; Kim, C. Y.

2017-06-01

A transmission line is discussed for application in an underwater spark-discharge technique in the cleaning of a horizontal well by incorporating a power-transmission model into the simulation. The pulsed-spark-discharge technique has been proposed for clogged-well rehabilitation, because it removes incrustations that are attached to well screens by using strong pressure waves that are generated by the rapid expansion of a spark channel. To apply the pulsed-spark-discharge technique to the cleaning of horizontal wells, the coaxial cable between the pulsed power supply and the spark gap as a load needs to be extended to a few hundred meters. Prior to field application, pulsed-spark-discharge experiments were conducted and the role of the transmission line was examined using an improved simulation model. In the model, a non-linear interaction of the spark channel and the capacitor bank is described by the pulse-forming action of the coaxial cable. Based on the accurate physical properties of the water plasma, such as the equation of state and electrical conductivity within the region of interest, the amount of energy contributed to the development of a shock wave was evaluated. The simulation shows that if the initial conditions of the spark channel are the same, no further reduction in strength of the pressure wave occurs, even if the cable length is increased above 50 m. Hence, the degraded peak pressure that was observed in the experiments using the longer cable is attributed to a change in the initial condition of the spark channel. The parametric study suggests that the low initial charging voltage, the high ambient water pressure, and the long cable length yield the low initial spark-channel density, which results in a reduced peak pressure. The simulation of line charging is presented to discuss the principle of disturbing the pre-breakdown process by an extended cable.

Active Heat Injection to Investigate Seepage Conditions Along the Interface Between a Concrete Diversion Sluiceway and Earthen Embankment Dam

NASA Astrophysics Data System (ADS)

Ringeri, A.; Butler, K. E.; MacQuarrie, K. T. B.

2016-12-01

The interface between embankment dams and adjoining hydraulic structures are regions which can give rise to seepage defects. A field experiment was conducted at the Mactaquac Generating Station in New Brunswick, Canada using active thermometry to investigate seepage conditions along the interface of a diversion sluiceway and earth embankment. The method involved monitoring the time evolution of temperature following the injection of a controlled heat pulse from a subsurface heat cable acting as a line source. Transient anomalies in the induced temperature field can result from the aberration of thermal properties and flow conditions which accompany defects. An industrial heat trace cable and distributed temperature sensing (DTS) fibre optic cable were installed in two parallel, 42 m deep, sub-vertical boreholes separated by 3 m and offset 0.5 m from the core-concrete interface. The heat and DTS cables were installed in the upstream and downstream boreholes respectively. Heat was injected as a box car function at a constant rate of 78.72 W/m for 51 d while the DTS cable, with a 20 cm sampling resolution, was averaged over 10 min at 30 min intervals for 300 d. The DTS cable successfully detected temperature changes induced by the upstream heat pulse. A coherent temperature response occurred along a 13 m section of deep fibre, where mean peak temperatures rose 1.59 ± 0.03 °C above ambient temperatures with an average time lag of 8.2 d following the end of the heating cycle. Two temperature anomalies above this region coincided with the position of the water table and the location of a previously detected fibre break. The method appears to be particularly useful in seepage surveillance of the deeper regions of the interface. Further analysis is required to remove the influence of seasonal temperatures on the heat pulse response at shallow depths.

SiC formation for a solar cell passivation layer using an RF magnetron co-sputtering system

PubMed Central

2012-01-01

In this paper, we describe a method of amorphous silicon carbide film formation for a solar cell passivation layer. The film was deposited on p-type silicon (100) and glass substrates by an RF magnetron co-sputtering system using a Si target and a C target at a room-temperature condition. Several different SiC [Si1-xCx] film compositions were achieved by controlling the Si target power with a fixed C target power at 150 W. Then, structural, optical, and electrical properties of the Si1-xCx films were studied. The structural properties were investigated by transmission electron microscopy and secondary ion mass spectrometry. The optical properties were achieved by UV-visible spectroscopy and ellipsometry. The performance of Si1-xCx passivation was explored by carrier lifetime measurement. PMID:22221730

Passivation of Black Phosphorus via Self-Assembled Organic Monolayers by van der Waals Epitaxy.

PubMed

Zhao, Yinghe; Zhou, Qionghua; Li, Qiang; Yao, Xiaojing; Wang, Jinlan

2017-02-01

An effective passivation approach to protect black phosphorus (BP) from degradation based on multi-scale simulations is proposed. The self-assembly of perylene-3,4,9,10-tetracarboxylic dianhydride monolayers via van der Waals epitaxy on BP does not break the original electronic properties of BP. The passivation layer thickness is only 2 nm. This study opens up a new pathway toward fine passivation of BP. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transport Of Passive Scalars In A Turbulent Channel Flow

NASA Technical Reports Server (NTRS)

Kim, John; Moin, Parviz

1990-01-01

Computer simulation of transport of passive scalars in turbulent channel flow described in report. Shows flow structures and statistical properties. As used here, "passive scalars" means scalar quantities like fluctuations in temperature or concentrations of contaminants that do not disturb flow appreciably. Examples include transport of heat in heat exchangers, gas turbines, and nuclear reactors and dispersal of pollution in atmosphere.

Electrical properties associated with wide intercellular clefts in rabbit Purkinje fibres.

PubMed Central

Colatsky, T J; Tsien, R W

1979-01-01

1. Rabbit Purkinje fibres were studied using micro-electrode recordings of electrical activity or a two-micro-electrode voltage clamp. Previous morphological work had suggested that these preparations offer structural advantages for the analysis of ionic permeability mechanisms. 2. Viable preparations could be obtained consistently by exposure to a K glutamate Tyrode solution during excision and recovery. In NaCl Tyrode solution, the action potential showed a large overshoot and fully developed plateau, but no pacemaker depolarization at negative potentials. 3. The passive electrical properties were consistent with morphological evidence for the accessibility of cleft membranes within the cell bundle. Electrotonic responses to intracellular current steps showed the behaviour expected for a simple leaky capacitative cable. Capacitative current transients under voltage clamp were changed very little by an eightfold reduction in the external solution conductivity. 4. Slow current changes attributable to K depletion were small compared to those found in other cardiac preparations. The amount of depletion was close to that predicted by a cleft model which assumed free K diffusion in 1 micron clefts. 5. Step depolarizations over the plateau range of potentials evoked a slow inward current which was resistant to tetrodotoxin but blocked by D600. 6. Strong depolarizations to potentials near 0 mV elicited a transient outward current and a slowly activating late outward current. Both components resembled currents found in sheep or calf Purkinje fibres. 7. These experiments support previous interpretations of slow plateau currents in terms of genuine permeability changes. The rabbit Purkinje fibre may allow various ionic channels to be studied with relatively little interference from radial non-uniformities in membrane potential or ion concentration. Images Fig. 7 PMID:469754

A deflectable guiding catheter for real-time MRI-guided interventions

PubMed Central

Bell, Jamie A.; Saikus, Christina E.; Ratnakaya, Kanishka; Wu, Vincent; Sonmez, Merdim; Faranesh, Anthony Z.; Colyer, Jessica H.; Lederman, Robert J.; Kocaturk, Ozgur

2011-01-01

Purpose To design a deflectable guiding catheter that omits long metallic components yet preserves mechanical properties to facilitate therapeutic interventional MRI procedures. Materials and Methods The catheter shaft incorporated Kevlar braiding. 180° deflection was attained with a 5 cm nitinol slotted tube, a nitinol spring, and a Kevlar pull string. We tested three designs: passive, passive incorporating an inductively-coupled coil, and active receiver. We characterized mechanical properties, MRI properties, RF induced heating, and in vivo performance in swine. Results Torque and tip deflection force were satisfactory. Representative procedures included hepatic and azygos vein access, laser cardiac septostomy, and atrial septal defect crossing. Visualization was best in the active configuration, delineating profile and tip orientation. The passive configuration could be used in tandem with an active guidewire to overcome its limited conspicuity. There was no RF-induced heating in all configurations under expected use conditions in vitro and in vivo. Conclusion Kevlar and short nitinol component substitutions preserved mechanical properties. The active design offered the best visibility and usability but reintroduced metal conductors. We describe versatile deflectable guiding catheters with a 0.057” lumen for interventional MRI catheterization. Implementations are feasible using active, inductive, and passive visualization strategies to suit application requirements. PMID:22128071

A Novel Actuator for Simulation of Epidural Anesthesia and Other Needle Insertion Procedures

PubMed Central

Magill, John C.; Byl, Marten F.; Hinds, Michael F.; Agassounon, William; Pratt, Stephen D.; Hess, Philip E.

2010-01-01

Introduction When navigating a needle from skin to epidural space, a skilled clinician maintains a mental model of the anatomy and uses the various forms of haptic and visual feedback to track the location of the needle tip. Simulating the procedure requires an actuator that can produce the feel of tissue layers even as the needle direction changes from the ideal path. Methods A new actuator and algorithm architecture simulate forces associated with passing a needle through varying tissue layers. The actuator uses a set of cables to suspend a needle holder. The cables are wound onto spools controlled by brushless motors. An electromagnetic tracker is used to monitor the position of the needle tip. Results Novice and expert clinicians simulated epidural insertion with the simulator. Preliminary depth-time curves show that the user responds to changes in tissue properties as the needle is advanced. Some discrepancy in clinician response indicates that the feel of the simulator is sensitive to technique, thus perfect tissue property simulation has not been achieved. Conclusions The new simulator is able to approximately reproduce properties of complex multilayer tissue structures, including fine-scale texture. Methods for improving fidelity of the simulation are identified. PMID:20651481

A novel actuator for simulation of epidural anesthesia and other needle insertion procedures.

PubMed

Magill, John C; Byl, Marten F; Hinds, Michael F; Agassounon, William; Pratt, Stephen D; Hess, Philip E

2010-06-01

When navigating a needle from skin to epidural space, a skilled clinician maintains a mental model of the anatomy and uses the various forms of haptic and visual feedback to track the location of the needle tip. Simulating the procedure requires an actuator that can produce the feel of tissue layers even as the needle direction changes from the ideal path. A new actuator and algorithm architecture simulate forces associated with passing a needle through varying tissue layers. The actuator uses a set of cables to suspend a needle holder. The cables are wound onto spools controlled by brushless motors. An electromagnetic tracker is used to monitor the position of the needle tip. Novice and expert clinicians simulated epidural insertion with the simulator. Preliminary depth-time curves show that the user responds to changes in tissue properties as the needle is advanced. Some discrepancy in clinician response indicates that the feel of the simulator is sensitive to technique, thus perfect tissue property simulation has not been achieved. The new simulator is able to approximately reproduce properties of complex multilayer tissue structures, including fine-scale texture. Methods for improving fidelity of the simulation are identified.

Cable equation for general geometry

NASA Astrophysics Data System (ADS)

López-Sánchez, Erick J.; Romero, Juan M.

2017-02-01

The cable equation describes the voltage in a straight cylindrical cable, and this model has been employed to model electrical potential in dendrites and axons. However, sometimes this equation might give incorrect predictions for some realistic geometries, in particular when the radius of the cable changes significantly. Cables with a nonconstant radius are important for some phenomena, for example, discrete swellings along the axons appear in neurodegenerative diseases such as Alzheimers, Parkinsons, human immunodeficiency virus associated dementia, and multiple sclerosis. In this paper, using the Frenet-Serret frame, we propose a generalized cable equation for a general cable geometry. This generalized equation depends on geometric quantities such as the curvature and torsion of the cable. We show that when the cable has a constant circular cross section, the first fundamental form of the cable can be simplified and the generalized cable equation depends on neither the curvature nor the torsion of the cable. Additionally, we find an exact solution for an ideal cable which has a particular variable circular cross section and zero curvature. For this case we show that when the cross section of the cable increases the voltage decreases. Inspired by this ideal case, we rewrite the generalized cable equation as a diffusion equation with a source term generated by the cable geometry. This source term depends on the cable cross-sectional area and its derivates. In addition, we study different cables with swelling and provide their numerical solutions. The numerical solutions show that when the cross section of the cable has abrupt changes, its voltage is smaller than the voltage in the cylindrical cable. Furthermore, these numerical solutions show that the voltage can be affected by geometrical inhomogeneities on the cable.

Influence of square wave anodization on the electronic properties and structures of the passive films on Ti in sulfuric acid solution

NASA Astrophysics Data System (ADS)

Long, Y.; Li, D. G.; Chen, D. R.

2017-12-01

Two types of square wave anodization (type 1 and type 2) were employed in this work to form a passive film on Ti in a 0.5 M H2SO4 solution. The influences of the anodization potential and duration on the electronic properties and structures of the passive films were studied by Mott-Schottky plots, auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). The results showed that the donor density, ND, of the passive film decreased and the flat band potential, EFB, shifted to the positive direction with the increase of the anodization duration and high anodization potential irrespective of whether type 1 or type 2 was used. Moreover, the passive film that formed on Ti using type 1 had a lower donor density and a more positive flat band potential than that on Ti using type 2 at one fixed anodization duration (only exchanging the anodization order of 1 V and the high potential). XPS analysis revealed that the outmost passive film was only composed of TiO2, the inner passive film was mainly composed of TiO2 with some amount of TiO and Ti2O3, and the TiO2 concentration in the outermost passive film increased with the increase of the anodization duration and the high potential in the case of using type 1 or type 2, implying an increased degree of crystallinity. The AES results showed that the O/Ti atomic ratio of the passive film obviously increased with the increasing anodization duration and high potential, demonstrating the increased homogeneous characteristic of the passive film; this was in agreement with the Mott-Schottky and XPS results.

Finite Element Modeling of Passive Material Influence on the Deformation and Force Output of Skeletal Muscle

PubMed Central

Hodgson, John A.; Chi, Sheng-Wei; Yang, Judy P.; Chen, Jiun-Shyan; Edgerton, V. Reggie; Sinha, Shantanu

2014-01-01

The pattern of deformation of the different structural components of a muscle-tendon complex when it is activated provides important information about the internal mechanics of the muscle. Recent experimental observations of deformations in contracting muscle have presented inconsistencies with current widely held assumption about muscle behavior. These include negative strain in aponeuroses, non-uniform strain changes in sarcomeres, even of individual muscle fibers and evidence that muscle fiber cross sectional deformations are asymmetrical suggesting a need to readjust current models of contracting muscle. We report here our use of finite element modeling techniques to simulate a simple muscle-tendon complex and investigate the influence of passive intramuscular material properties upon the deformation patterns under isometric and shortening conditions. While phenomenological force-displacement relationships described the muscle fiber properties, the material properties of the passive matrix were varied to simulate a hydrostatic model, compliant and stiff isotropically hyperelastic models and an anisotropic elastic model. The numerical results demonstrate that passive elastic material properties significantly influence the magnitude, heterogeneity and distribution pattern of many measures of deformation in a contracting muscle. Measures included aponeurosis strain, aponeurosis separation, muscle fiber strain and fiber cross-sectional deformation. The force output of our simulations was strongly influenced by passive material properties, changing by as much as ~80% under some conditions. Maximum output was accomplished by introducing anisotropy along axes which were not strained significantly during a muscle length change, suggesting that correct costamere orientation may be a critical factor in optimal muscle function. Such a model not only fits known physiological data, but also maintains the relatively constant aponeurosis separation observed during in vivo muscle contractions and is easily extrapolated from our plane-strain conditions into a 3-dimensional structure. Such modeling approaches have the potential of explaining the reduction of force output consequent to changes in material properties of intramuscular materials arising in the diseased state such as in genetic disorders. PMID:22498294

Finite element modeling of passive material influence on the deformation and force output of skeletal muscle.

PubMed

Hodgson, John A; Chi, Sheng-Wei; Yang, Judy P; Chen, Jiun-Shyan; Edgerton, Victor R; Sinha, Shantanu

2012-05-01

The pattern of deformation of different structural components of a muscle-tendon complex when it is activated provides important information about the internal mechanics of the muscle. Recent experimental observations of deformations in contracting muscle have presented inconsistencies with current widely held assumption about muscle behavior. These include negative strain in aponeuroses, non-uniform strain changes in sarcomeres, even of individual muscle fibers and evidence that muscle fiber cross sectional deformations are asymmetrical suggesting a need to readjust current models of contracting muscle. We report here our use of finite element modeling techniques to simulate a simple muscle-tendon complex and investigate the influence of passive intramuscular material properties upon the deformation patterns under isometric and shortening conditions. While phenomenological force-displacement relationships described the muscle fiber properties, the material properties of the passive matrix were varied to simulate a hydrostatic model, compliant and stiff isotropically hyperelastic models and an anisotropic elastic model. The numerical results demonstrate that passive elastic material properties significantly influence the magnitude, heterogeneity and distribution pattern of many measures of deformation in a contracting muscle. Measures included aponeurosis strain, aponeurosis separation, muscle fiber strain and fiber cross-sectional deformation. The force output of our simulations was strongly influenced by passive material properties, changing by as much as ~80% under some conditions. The maximum output was accomplished by introducing anisotropy along axes which were not strained significantly during a muscle length change, suggesting that correct costamere orientation may be a critical factor in the optimal muscle function. Such a model not only fits known physiological data, but also maintains the relatively constant aponeurosis separation observed during in vivo muscle contractions and is easily extrapolated from our plane-strain conditions into a three-dimensional structure. Such modeling approaches have the potential of explaining the reduction of force output consequent to changes in material properties of intramuscular materials arising in the diseased state such as in genetic disorders. Copyright © 2012 Elsevier Ltd. All rights reserved.

A simplified fragility analysis of fan type cable stayed bridges

NASA Astrophysics Data System (ADS)

Khan, R. A.; Datta, T. K.; Ahmad, S.

2005-06-01

A simplified fragility analysis of fan type cable stayed bridges using Probabilistic Risk Analysis (PRA) procedure is presented for determining their failure probability under random ground motion. Seismic input to the bridge support is considered to be a risk consistent response spectrum which is obtained from a separate analysis. For the response analysis, the bridge deck is modeles as a beam supported on spring at different points. The stiffnesses of the springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysis provides a coupled stiffness matrix for the spring system. A continuum method of analysis using dynamic stiffness is used to determine the dynamic properties of the bridges. The response of the bridge deck is obtained by the response spectrum method of analysis as applied to multidegree of freedom system which duly takes into account the quasi-static component of bridge deck vibration. The fragility analysis includes uncertainties arising due to the variation in ground motion, material property, modeling, method of analysis, ductility factor and damage concentration effect. Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM) method of reliability. A three span double plane symmetrical fan type cable stayed bridge of total span 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure are obtained under a number of parametric variations. Some of the important conclusions of the study indicate that (i) not only vertical component but also the horizontal component of ground motion has considerable effect on the probability of failure; (ii) ground motion with no time lag between support excitations provides a smaller probability of failure as compared to ground motion with very large time lag between support excitation; and (iii) probability of failure may considerably increase soft soil condition.

Ten Years of Observatory Science from Saanich Inlet on the VENUS Cabled Ocean Observatory

NASA Astrophysics Data System (ADS)

Dewey, R. K.; Tunnicliffe, V.; Macoun, P.; Round, A.

2016-02-01

The Saanich Inlet array of the VENUS cabled ocean observatory, maintained and operated by Ocean Networks Canada, was installed in February 2006, and in 2016 will have supported ten years of comprehensive interactive science. Representing the first in the present generation of cabled observing technologies, this coastal array has provided continuous high power and broadband communications to a variety of instrument platforms, hundreds of sensors, and enabled dozens of short, medium, and long-term studies. Saanich Inlet is a protected fjord with limited tidal action, resulting in an extremely productive environment, with strong seasonal chemical variations driven by episodic deep water renewal events and oxygen reduction processes. The breadth of the research has included microbial and benthic community dynamics, biogeochemical cycles, forensics, quantifying inter-annual variations, benthic-pelagic coupling, sensor testing, plankton dynamics, and bio-turbulence. Observatory measurements include core water properties (CTD & O2) and water-column echo-sounder records, as well as experiment-oriented deployments utilizing cameras, Gliders, Dopplers, hydrophones, and a variety of biogeochemical sensors. With a recently installed Buoy Profiler System for monitoring the entire water column, community plans continue with a dedicated Redox experiment through the 2016-17 seasons. Highlights from the dozens of research papers and theses will be presented to demonstrate the achievements enabled by a comprehensive coastal cabled observing system.

Multispectral Analysis of Surface Wave (MASW) Analysis of Near-Surface Structure at Brady Hot Springs from Active Source and Ambient Noise Using a 8700-meter Distributed Acoustic Sensing (DAS) Array

NASA Astrophysics Data System (ADS)

Wang, H. F.; Lord, N. E.; Zeng, X.; Fratta, D.; Feigl, K. L.; Team, P.

2016-12-01

The Porotomo research team deployed 8700-meters of Distributed Acoustic Sensing (DAS) cable in a shallow trench on the surface and 400 meters down a borehole at Brady Hot Springs, Nevada in March 2016. The goal of the experiment was to detect changes in geophysical properties associated with hydrologic changes. The DAS cable occupied a natural laboratory of 1500-by-500-by-400-meters overlying a commercial, geothermal field operated by Ormat Technologies. The DAS cable was laid out in three parallel zig-zag lines with line segments approximately 120-meters in length. A large Vibroseis truck (T-Rex) provided the seismic source with a sweep frequency between 5 and 80 Hz over 20 seconds. Over the 15 days of the experiment, the Vibroseis truck re-occupied approximately 250 locations outside and within the array days while changes were made in water reinjection from the power plant into wells in the field. At each source location, one vertical and two orthogonal horizontal modes were excited. Dispersion curves were constructed using MASW and a Vibroseis source location approximately in line with each DAS cable segment or from ambient noise correlation functions. Representative fence diagrams of S-wave profiles were constructed by inverting the dispersion curves obtained for several different line segments.

An equivalent frequency approach for determining non-linear effects on pre-tensioned-cable cross-braced structures

NASA Astrophysics Data System (ADS)

Giaccu, Gian Felice

2018-05-01

Pre-tensioned cable braces are widely used as bracing systems in various structural typologies. This technology is fundamentally utilized for stiffening purposes in the case of steel and timber structures. The pre-stressing force imparted to the braces provides to the system a remarkable increment of stiffness. On the other hand, the pre-tensioning force in the braces must be properly calibrated in order to satisfactorily meet both serviceability and ultimate limit states. Dynamic properties of these systems are however affected by non-linear behavior due to potential slackening of the pre-tensioned brace. In the recent years the author has been working on a similar problem regarding the non-linear response of cables in cable-stayed bridges and braced structures. In the present paper a displacement-based approach is used to examine the non-linear behavior of a building system. The methodology operates through linearization and allows obtaining an equivalent linearized frequency to approximately characterize, mode by mode, the dynamic behavior of the system. The equivalent frequency depends on both the mechanical characteristics of the system, the pre-tensioning level assigned to the braces and a characteristic vibration amplitude. The proposed approach can be used as a simplified technique, capable of linearizing the response of structural systems, characterized by non-linearity induced by the slackening of pre-tensioned braces.

Numerical investigation of metal-semiconductor-insulator-semiconductor passivated hole contacts based on atomic layer deposited AlO x

NASA Astrophysics Data System (ADS)

Ke, Cangming; Xin, Zheng; Ling, Zhi Peng; Aberle, Armin G.; Stangl, Rolf

2017-08-01

Excellent c-Si tunnel layer surface passivation has been obtained recently in our lab, using atomic layer deposited aluminium oxide (ALD AlO x ) in the tunnel layer regime of 0.9 to 1.5 nm, investigated to be applied for contact passivation. Using the correspondingly measured interface properties, this paper compares the theoretical collection efficiency of a conventional metal-semiconductor (MS) contact on diffused p+ Si to a metal-semiconductor-insulator-semiconductor (MSIS) contact on diffused p+ Si or on undoped n-type c-Si. The influences of (1) the tunnel layer passivation quality at the tunnel oxide interface (Q f and D it), (2) the tunnel layer thickness and the electron and hole tunnelling mass, (3) the tunnel oxide material, and (4) the semiconductor capping layer material properties are investigated numerically by evaluation of solar cell efficiency, open-circuit voltage, and fill factor.

Passivation properties of alumina for multicrystalline silicon nanostructure prepared by spin-coating method

NASA Astrophysics Data System (ADS)

Jiang, Ye; Shen, Honglie; Yang, Wangyang; Zheng, Chaofan; Tang, Quntao; Yao, Hanyu; Raza, Adil; Li, Yufang; Huang, Chunlai

2018-02-01

In this paper, we report passivation properties of inverted pyramidal nanostructure based multi-crystalline silicon (mc-Si) by Al2O3 films with spin-coating method. Precursors AlCl3 and Al(acac)3 for Al2O3 films were chosen for comparison. Al2O3/SiO x stacks were found to be able to passivate the nanostructured surface well. With the number of spin-coating up to five, the Al2O3 films could conformally attach the nanostructure. The weighted average reflectance values (ranging from 400-900 nm) of the passivated silicon surface could be reduced to 10.74% (AlCl3) and 11.12% (Al(acac)3), and the effective carrier lifetime could reach 7.84 and 16.98 μs, respectively. This work presented a potential process to fabricate low cost high efficiency mc-Si solar cells.

Rear-Sided Passivation by SiNx:H Dielectric Layer for Improved Si/PEDOT:PSS Hybrid Heterojunction Solar Cells.

PubMed

Sun, Yiling; Gao, Pingqi; He, Jian; Zhou, Suqiong; Ying, Zhiqin; Yang, Xi; Xiang, Yong; Ye, Jichun

2016-12-01

Silicon/organic hybrid solar cells have recently attracted great attention because they combine the advantages of silicon (Si) and the organic cells. In this study, we added a patterned passivation layer of silicon nitride (SiNx:H) onto the rear surface of the Si substrate in a Si/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) hybrid solar cell, enabling an improvement of 0.6 % in the power conversion efficiency (PCE). The addition of the SiNx:H layer boosted the open circuit voltage (V oc) from 0.523 to 0.557 V, suggesting the well-passivation property of the patterned SiNx:H thin layer that was created by plasma-enhanced chemical vapor deposition and lithography processes. The passivation properties that stemmed from front PSS, rear-SiNx:H, front PSS/rear-SiNx:H, etc. are thoroughly investigated, in consideration of the process-related variations.

SHORT-PULSE ELECTROMAGNETIC TRANSPONDER FOR HOLE-TO-HOLE USE.

USGS Publications Warehouse

Wright, David L.; Watts, Raymond D.; Bramsoe, Erik

1983-01-01

Hole-to-hole observations were made through nearly 20 m of granite using an electromagnetic transponder (an active reflector) in one borehole and a single-hole short-pulse radar in another. The transponder is inexpensive, operationally simple, and effective in extending the capability of a short-pulse borehole radar system to allow hole-to-hole operation without requiring timing cables. A detector in the transponder senses the arrival of each pulse from the radar. Each pulse detection triggers a kilovolt-amplitude pulse for retransmission. The transponder 'echo' may be stronger than that of a passive reflector by a factor of as much as 120 db. The result is an increase in range capability by a factor which depends on attenuation in the medium and hole-to-hole wavepath geometry.

Cable and Line Inspection Mechanism

NASA Technical Reports Server (NTRS)

Ross, Terence J. (Inventor)

2003-01-01

An automated cable and line inspection mechanism visually scans the entire surface of a cable as the mechanism travels along the cable=s length. The mechanism includes a drive system, a video camera, a mirror assembly for providing the camera with a 360 degree view of the cable, and a laser micrometer for measuring the cable=s diameter. The drive system includes an electric motor and a plurality of drive wheels and tension wheels for engaging the cable or line to be inspected, and driving the mechanism along the cable. The mirror assembly includes mirrors that are positioned to project multiple images of the cable on the camera lens, each of which is of a different portion of the cable. A data transceiver and a video transmitter are preferably employed for transmission of video images, data and commands between the mechanism and a remote control station.

Cable and line inspection mechanism

NASA Technical Reports Server (NTRS)

Ross, Terence J. (Inventor)

2003-01-01

An automated cable and line inspection mechanism visually scans the entire surface of a cable as the mechanism travels along the cable=s length. The mechanism includes a drive system, a video camera, a mirror assembly for providing the camera with a 360 degree view of the cable, and a laser micrometer for measuring the cable=s diameter. The drive system includes an electric motor and a plurality of drive wheels and tension wheels for engaging the cable or line to be inspected, and driving the mechanism along the cable. The mirror assembly includes mirrors that are positioned to project multiple images of the cable on the camera lens, each of which is of a different portion of the cable. A data transceiver and a video transmitter are preferably employed for transmission of video images, data and commands between the mechanism and a remote control station.

Microwave remote sensing of sea ice in the AIDJEX Main Experiment. [Arctic Ice Dynamics Joint Experiment

NASA Technical Reports Server (NTRS)

Campbell, W. J.; Wayenberg, J.; Ramseyer, J. B.; Ramseier, R. O.; Vant, M. R.; Weaver, R.; Redmond, A.; Arsenault, L.; Gloersen, P.; Zwally, H. J.

1978-01-01

A microwave remote sensing program of sea ice in the Beaufort Sea was conducted during the Arctic Ice Dynamics Joint Experiment (AIDJEX). Several types of both passive and active sensors were used to perform surface and aircraft measurements during all seasons of the year. In situ observations were made of physical properties (salinity, temperature, density, surface roughness), dielectric properties, and passive microwave measurements were made of first-year, multiyear, and first-year/multiyear mixtures. Airborne passive microwave measurements were performed with the electronically scanning microwave radiometer while airborne active microwave measurements were performed by synthetic aperture radar, X- and L-band radar, and a scatterometer.

Mechanisms of Cables 1 gene inactivation in human ovarian cancer development.

PubMed

Sakamoto, Hideo; Friel, Anne M; Wood, Antony W; Guo, Lankai; Ilic, Ana; Seiden, Michael V; Chung, Daniel C; Lynch, Maureen P; Serikawa, Takehiro; Munro, Elizabeth; Oliva, Esther; Orsulic, Sandra; Kirley, Sandra D; Foster, Rosemary; Zukerberg, Lawrence R; Rueda, Bo R

2008-02-01

Cables 1, a cyclin-dependent kinase binding protein, is primarily involved in cell cycle regulation. Loss of nuclear Cables 1 expression is observed in human colon, lung and endometrial cancers. We previously reported that loss of nuclear Cables 1 expression was also observed with high frequency in a limited sample set of human ovarian carcinomas, although the mechanisms underlying loss of nuclear Cables 1 expression remained unknown. Our present objective was to examine Cables 1 expression in ovarian cancer in greater detail, and determine the predominant mechanisms of Cables 1 loss. We assessed potential genetic and epigenetic modifications of the Cables 1 locus through analyses of mutation, polymorphisms, loss of heterozygosity and DNA methylation. We observed a marked loss of nuclear Cables 1 expression in serous and endometrioid ovarian carcinomas that correlated with decreased Cables 1 mRNA levels. Although we detected no Cables 1 mutations, there was evidence of LOH at the Cables 1 locus and epigenetic modification of the Cables 1 promoter region in a subset of ovarian carcinomas and established cancer cell lines. From a functional perspective, over-expression of Cables 1 induced apoptosis, whereas, knockdown of Cables 1 negated this effect. Together these findings suggest that multiple mechanisms underlie the loss of Cables 1 expression in ovarian cancer cells, supporting the hypothesis that Cables 1 is a tumor suppressor in human ovarian cancer.

Development of inspection robots for bridge cables.

PubMed

Yun, Hae-Bum; Kim, Se-Hoon; Wu, Liuliu; Lee, Jong-Jae

2013-01-01

This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

Symmetry Breaking in a random passive scalar

NASA Astrophysics Data System (ADS)

Kilic, Zeliha; McLaughlin, Richard; Camassa, Roberto

2017-11-01

We consider the evolution of a decaying passive scalar in the presence of a gaussian white noise fluctuating shear flow. We focus on deterministic initial data and establish the short, intermediate, and long time symmetry properties of the evolving point wise probability measure for the random passive scalar. Analytical results are compared directly to Monte Carlo simulations. Time permitting we will compare the predictions to experimental observations.

A density functional theory study of the role of functionalized graphene particles as effective additives in power cable insulation

PubMed Central

Song, Shuwei; Zhao, Hong; Zheng, Xiaonan; Zhang, Hui; Wang, Ying; Han, Baozhong

2018-01-01

The role of a series of functionalized graphene additives in power cable insulation in suppressing the growth of electrical treeing and preventing the degradation of the polymer matrix has been investigated by density functional theory calculations. Bader charge analysis indicates that pristine, doped or defect graphene could effectively capture hot electrons to block their attack on cross-linked polyethylene (XLPE) because of the π–π conjugated unsaturated structures. Further exploration of the electronic properties in the interfacial region between the additives and XLPE shows that N-doped single-vacancy graphene, graphene oxide and B-, N-, Si- or P-doped graphene oxide have relatively strong physical interaction with XLPE to restrict its mobility and rather weak chemical activity to prevent the cleavage of the C–H or C–C bond, suggesting that they are all potential candidates as effective additives. The understanding of the features of functionalized graphene additives in trapping electrons and interfacial interaction will assist in the screening of promising additives as voltage stabilizers in power cables. PMID:29515821

Ultrastrong Graphene-Copper Core-Shell Wires for High-Performance Electrical Cables.

PubMed

Kim, Sang Jin; Shin, Dong Heon; Choi, Yong Seok; Rho, Hokyun; Park, Min; Moon, Byung Joon; Kim, Youngsoo; Lee, Seuoung-Ki; Lee, Dong Su; Kim, Tae-Wook; Lee, Sang Hyun; Kim, Keun Soo; Hong, Byung Hee; Bae, Sukang

2018-03-27

Recent development in mobile electronic devices and electric vehicles requires electrical wires with reduced weight as well as enhanced stability. In addition, since electric energy is mostly generated from power plants located far from its consuming places, mechanically stronger and higher electric power transmission cables are strongly demanded. However, there has been no alternative materials that can practically replace copper materials. Here, we report a method to prepare ultrastrong graphene fibers (GFs)-Cu core-shell wires with significantly enhanced electrical and mechanical properties. The core GFs are synthesized by chemical vapor deposition, followed by electroplating of Cu shells, where the large surface area of GFs in contact with Cu maximizes the mechanical toughness of the core-shell wires. At the same time, the unique electrical and thermal characteristics of graphene allow a ∼10 times higher current density limit, providing more efficient and reliable delivery of electrical energies through the GFs-Cu wires. We believe that our results would be useful to overcome the current limit in electrical wires and cables for lightweight, energy-saving, and high-power applications.

A density functional theory study of the role of functionalized graphene particles as effective additives in power cable insulation.

PubMed

Song, Shuwei; Zhao, Hong; Zheng, Xiaonan; Zhang, Hui; Liu, Yang; Wang, Ying; Han, Baozhong

2018-02-01

The role of a series of functionalized graphene additives in power cable insulation in suppressing the growth of electrical treeing and preventing the degradation of the polymer matrix has been investigated by density functional theory calculations. Bader charge analysis indicates that pristine, doped or defect graphene could effectively capture hot electrons to block their attack on cross-linked polyethylene (XLPE) because of the π-π conjugated unsaturated structures. Further exploration of the electronic properties in the interfacial region between the additives and XLPE shows that N-doped single-vacancy graphene, graphene oxide and B-, N-, Si- or P-doped graphene oxide have relatively strong physical interaction with XLPE to restrict its mobility and rather weak chemical activity to prevent the cleavage of the C-H or C-C bond, suggesting that they are all potential candidates as effective additives. The understanding of the features of functionalized graphene additives in trapping electrons and interfacial interaction will assist in the screening of promising additives as voltage stabilizers in power cables.

Coronal plasma development in wire-array z-pinches made of twisted-pairs

NASA Astrophysics Data System (ADS)

Hoyt, C. L.; Greenly, J. B.; Gourdain, P. A.; Knapp, P. F.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.; Kusse, B. R.

2009-11-01

We have investigated coronal and core plasma development in wire array z-pinches in which single fine wires are replaced by twisted-pairs (``cable'') on the 1 MA, 100 ns rise time COBRA pulsed power generator. X-ray radiography, employed to investigate dense wire core expansion, showed periodic axial nonuniformity and evidence for shock waves developing where the individual wire plasmas collide. Laser shadowgraphy images indicated that the axial instability properties of the coronal plasma are substantially modified from ordinary wire arrays. Cable mass per unit length, material and the twist wavelength were varied in order to study their effects upon the instability wavelength. Implosion uniformity and bright-spot formation, as well as magnetic topology evolution, have also been investigated using self-emission imaging, x-ray diagnostics and small B-dot probes, respectively. Results from the cable-array z-pinches will be compared with results from ordinary wire-array z-pinches. This research was supported by the SSAA program of the National Nuclear Security Administration under DOE Cooperative agreement DE-FC03-02NA00057.

Environmental Impact of a Submarine Cable: Case Study of the Acoustic Thermometry of Ocean Climate (ATOC)/ Pioneer Seamount Cable

NASA Astrophysics Data System (ADS)

Kogan, I.; Paull, C. K.; Kuhnz, L.; von Thun, S.; Burton, E.; Greene, H. G.; Barry, J. P.

2003-12-01

To better understand the potential impacts of the presence of cables on the seabed, a topic of interest for which little data is published or publicly available, a study of the environmental impacts of the ATOC/Pioneer Seamount cable was conducted. The 95 km long, submarine, coaxial cable extends between Pioneer Seamount and the Pillar Point Air Force Station in Half Moon Bay, California. Approximately two thirds of the cable lies within the Monterey Bay National Marine Sanctuary. The cable is permitted to NOAA- Oceanic and Atmospheric Research for transmitting data from a hydrophone array on Pioneer Seamount to shore. The cable was installed unburied on the seafloor in 1995. The cable path crosses the continental shelf, descends to a maximum depth of 1,933 m, and climbs back upslope to 998 m depth near the crest of Pioneer Seamount. A total of 42 hours of video and 152 push cores were collected in 10 stations along cable and control transects using the ROVs Ventana and Tiburon equipped with cable-tracking tools. The condition of the cable, its effect on the seafloor, and distribution of benthic megafauna and infauna were determined. Video data indicated the nature of interaction between the cable and the seafloor. Rocky nearshore areas, where wave energies are greatest, showed the clearest evidence of impact. Here, evidence of abrasion included frayed and unraveling portions of the cable's armor and vertical grooves in the rock apparently cut by the cable. The greatest incision and armor damage occurred on ledges between spans in irregular rock outcrop areas. Unlike the nearshore rocky region, neither the rocks nor the cable appeared damaged along outcrops on Pioneer Seamount. Multiple loops of slack cable added during a 1997 cable repair operation were found lying flat on the seafloor. Several sharp kinks in the cable were seen at 240 m water depths in an area subjected to intense trawling activity. Most of the cable has become buried with time in sediment substrates on the continental shelf whereas much of the cable remains exposed in sediments at deeper depths. The cable is exposed in rocky environments of the nearshore region and on all of Pioneer Seamount. The main biological features associated with the cable were organisms utilizing the cable as substrate and occasionally as shelter. Considerable care was taken to count megafauna in video transects and macrofauna from the top 5 cm of push cores. Few differences were found between cable and control sites at the 95% confidence level. Anemones Metridium farcimen and Stomphia sp. colonized the cable and were more abundant in cable transects at most soft sediment sites. Coarse extrapolation of the transect data suggest that more than 5,000 M. farcimen may live on the continental shelf portion of the cable. Several other species of anemones living on the cable are common along deeper sections of the cable route. Where the cable was buried, the presence of linear rows of sea anemones proved to be a reliable indicator of the cable's position. Flatfish and rockfish apparently congregate near the cable and were as much as 1 order of magnitude more abundant near the cable at some sites.

30 CFR 75.827 - Guarding of trailing cables.

Code of Federal Regulations, 2012 CFR

2012-07-01

... grounded metal. (b) Suspended cables and cable crossovers. When equipment must cross any portion of the cable, the cable must be either: (1) Suspended from the mine roof; or (2) Protected by a cable crossover...

30 CFR 75.827 - Guarding of trailing cables.

Code of Federal Regulations, 2014 CFR

2014-07-01

... grounded metal. (b) Suspended cables and cable crossovers. When equipment must cross any portion of the cable, the cable must be either: (1) Suspended from the mine roof; or (2) Protected by a cable crossover...

30 CFR 75.827 - Guarding of trailing cables.

Code of Federal Regulations, 2011 CFR

2011-07-01

... grounded metal. (b) Suspended cables and cable crossovers. When equipment must cross any portion of the cable, the cable must be either: (1) Suspended from the mine roof; or (2) Protected by a cable crossover...

30 CFR 75.827 - Guarding of trailing cables.

Code of Federal Regulations, 2013 CFR

2013-07-01

... grounded metal. (b) Suspended cables and cable crossovers. When equipment must cross any portion of the cable, the cable must be either: (1) Suspended from the mine roof; or (2) Protected by a cable crossover...

47 CFR 76.802 - Disposition of cable home wiring.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 4 2013-10-01 2013-10-01 false Disposition of cable home wiring. 76.802... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Inside Wiring § 76.802 Disposition of cable home wiring... cable operator shall not remove the cable home wiring unless it gives the subscriber the opportunity to...

47 CFR 76.802 - Disposition of cable home wiring.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Disposition of cable home wiring. 76.802... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Inside Wiring § 76.802 Disposition of cable home wiring... cable operator shall not remove the cable home wiring unless it gives the subscriber the opportunity to...

47 CFR 76.802 - Disposition of cable home wiring.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Disposition of cable home wiring. 76.802... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Inside Wiring § 76.802 Disposition of cable home wiring... cable operator shall not remove the cable home wiring unless it gives the subscriber the opportunity to...

47 CFR 76.802 - Disposition of cable home wiring.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Disposition of cable home wiring. 76.802... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Inside Wiring § 76.802 Disposition of cable home wiring... cable operator shall not remove the cable home wiring unless it gives the subscriber the opportunity to...

47 CFR 27.1202 - Cable/BRS cross-ownership.

Code of Federal Regulations, 2014 CFR

2014-10-01

... portion of the franchise area actually served by the cable operator's cable system and the cable operator... franchise area actually served by the cable operator's cable system the cable operator will use the BRS... that no portion of the GSA of the BRS station is within the portion of the franchise area actually...

47 CFR 27.1202 - Cable/BRS cross-ownership.

Code of Federal Regulations, 2011 CFR

2011-10-01

... portion of the franchise area actually served by the cable operator's cable system and the cable operator... franchise area actually served by the cable operator's cable system the cable operator will use the BRS... that no portion of the GSA of the BRS station is within the portion of the franchise area actually...

47 CFR 27.1202 - Cable/BRS cross-ownership.

Code of Federal Regulations, 2012 CFR

2012-10-01

... portion of the franchise area actually served by the cable operator's cable system and the cable operator... franchise area actually served by the cable operator's cable system the cable operator will use the BRS... that no portion of the GSA of the BRS station is within the portion of the franchise area actually...

47 CFR 27.1202 - Cable/BRS cross-ownership.

Code of Federal Regulations, 2013 CFR

2013-10-01

... portion of the franchise area actually served by the cable operator's cable system and the cable operator... franchise area actually served by the cable operator's cable system the cable operator will use the BRS... that no portion of the GSA of the BRS station is within the portion of the franchise area actually...

Enhancement of Electrical Properties of Nanostructured Polysilicon Layers Through Hydrogen Passivation.

PubMed

Zhou, D; Xu, T; Lambert, Y; Cristini-Robbe; Stiévenard, D

2015-12-01

The light absorption of polysilicon planar junctions can be improved using nanostructured top surfaces due to their enhanced light harvesting properties. Nevertheless, associated with the higher surface, the roughness caused by plasma etching and defects located at the grain boundary in polysilicon, the concentration of the recombination centers increases, leading to electrical performance deterioration. In this work, we demonstrate that wet oxidation combined with hydrogen passivation using SiN(x):H are the key technological processes to significantly decrease the surface recombination and improve the electrical properties of nanostructured n(+)-i-p junctions. Nanostructured surface is fabricated by nanosphere lithography in a low-cost and controllable approach. Furthermore, it has been demonstrated that the successive annealing of silicon nitride films has significant effect on the passivation quality, resulting in some improvements on the efficiency of the Si nanostructure-based solar cell device.

Hydrogen passivation of polycrystalline silicon thin films

NASA Astrophysics Data System (ADS)

Scheller, L.-P.; Weizman, M.; Simon, P.; Fehr, M.; Nickel, N. H.

2012-09-01

The influence of post-hydrogenation on the electrical and optical properties of solid phase crystallized polycrystalline silicon (poly-Si) was examined. The passivation of grain-boundary defects was measured as a function of the passivation time. The silicon dangling-bond concentration decreases with increasing passivation time due to the formation of Si-H complexes. In addition, large H-stabilized platelet-like clusters are generated. The influence of H on the electrical properties was investigated using temperature dependent conductivity and Hall-effect measurements. For poly-Si on Corning glass, the dark conductivity decreases upon hydrogenation, while it increases when the samples are fabricated on silicon-nitride covered Borofloat glass. Hall-effect measurements reveal that for poly-Si on Corning glass the hole concentration and the mobility decrease upon post-hydrogenation, while a pronounced increase is observed for poly-Si on silicon-nitride covered Borofloat glass. This indicates the formation of localized states in the band gap, which is supported by sub band-gap absorption measurments. The results are discussed in terms of hydrogen-induced defect passivation and generation mechanisms.

Capability and Cost of COTS Networking Components

NASA Astrophysics Data System (ADS)

Hinteregger, Hans

In this talk we will emphasize first the ease with which dedicated 'dark' fiber can today be 'lit' at one or more gigE-bandwidth wavelengths with low-cost switches, optical transceivers with up to 100 Km reach, and passive mux/demux's. The chief expense for dedicated links today is that of leasing a fiber pair, especially in a city like Wash. DC. But, at least in the US, the intercity cable overbuild of the telecom boom has now, in the bust, made in-the-ground dark fiber pairs buyable for <$1000/km. Hence there are now business interests in COTS networking components,with corresponding opportunities for e-VLBI. We will outline the fairly clear and certain road from gigE in SFP to 10gigE in XFP commodity pluggable packages. The timing of cost/bandwidth crossover is less so - due to current uncertainty in the telecom business climate. A 2006 budget for LOFAR networking requirements, assumed here to be built from scratch in the WA desert where the dominant cable laying costs are minimized, is considered in some detail. The cost of fibers and the cost lighting them (one-way) to 200 Gb/s per station is judged to be affordable. A further projection to SKA's COFON in 2009 will be made. Denser CWDM and/or cheaper DWDM may be developed and mature by that time.

Experimental Measurements and Comparison of Cable Performance for Mine Hunting Applications

NASA Astrophysics Data System (ADS)

Mangum, Katherine

2005-11-01

The Naval Surface Warfare Center (NSWCCD) conducted testing of multiple faired synthetic cables in the High Speed Basin in April, 2005. The objective of the test was to determine the hydrodynamic characteristics of bare cables, ribbon faired cables, and cables with extruded plastic ``strakes.'' Faired cables are used to gain on-station time and improve performance of the MH-60 Helicopter when towing mine hunting vehicles. Drag and strum were compared for all cases. Strum was quantified by computing standard deviations of lateral cable acceleration amplitudes. Drag coefficients were calculated using cable tension and angle readings. While the straked cables strummed less than the bare synthetic cable, they did not reduce strum levels as well as ribbon fairing at steep cable angles for speeds of 10, 15, 20 and 25 knots. The drag coefficient of the straked cables was calculated to be higher than that of a bare cable, although further testing is needed to determine an exact number.

Development of Inspection Robots for Bridge Cables

PubMed Central

Kim, Se-Hoon; Lee, Jong-Jae

2013-01-01

This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented. PMID:24459453

Measurements of Leaky Coaxial Cables and Possible Applications to Train Communication

DOT National Transportation Integrated Search

1974-05-01

The electrical and radiation properties of the Radiax have been measured. The main results are: i) the surface wave exists, ii) the radial radiation follows 1/r2 relation for frequency below 190 MHz and 1/r relation for frequency near 400 MHz, iii) t...

The Properties of Condensed Explosives for Electromagnetic Energy Coupling,

DTIC Science & Technology

1985-10-01

CONCLUSIONS Due t o the 3-dimensional nature of the experiment, multiple reflections occurred within the eleccrode block during the course of the experiment...Self- integracion is used as a method of band-limiting to prevent resonance, as discussed later. Self-resonance and Cable Matching From Figure C-4

Comparison of degradation effects induced by gamma radiation and electron beam radiation in two cable jacketing materials

NASA Astrophysics Data System (ADS)

Bartoníček, B.; Plaček, V.; Hnát, V.

2007-05-01

The radiation degradation behavior of commercial low density polyethylene (LDPE) and ethylene-vinylacetate (EVA) cable materials has been investigated. The changes of mechanical properties, thermooxidative stability and density exhibit different radiation stability towards 60Co-gamma radiation and 160 keV electron beam radiation. This difference reflects much higher penetration of the gamma radiation through the polymeric material as a function of sample thickness. These results are discussed with respect to the role of beta radiation during design basis events in a nuclear power plants. In case when total accidental design basis event (DBE) dose (involving about 80% soft beta radiation) is simulated by 60Co-gamma radiation the conservatism is reached.

Damping Estimation from Free Decay Responses of Cables with MR Dampers.

PubMed

Weber, Felix; Distl, Hans

2015-01-01

This paper discusses the damping measurements on cables with real-time controlled MR dampers that were performed on a laboratory scale single strand cable and on cables of the Sutong Bridge, China. The control approach aims at producing amplitude and frequency independent cable damping which is confirmed by the tests. The experimentally obtained cable damping in comparison to the theoretical value due to optimal linear viscous damping reveals that support conditions of the cable anchors, force tracking errors in the actual MR damper force, energy spillover to higher modes, and excitation and sensor cables hanging on the stay cable must be taken into consideration for the interpretation of the identified cable damping values.

Damping Estimation from Free Decay Responses of Cables with MR Dampers

PubMed Central

Weber, Felix; Distl, Hans

2015-01-01

This paper discusses the damping measurements on cables with real-time controlled MR dampers that were performed on a laboratory scale single strand cable and on cables of the Sutong Bridge, China. The control approach aims at producing amplitude and frequency independent cable damping which is confirmed by the tests. The experimentally obtained cable damping in comparison to the theoretical value due to optimal linear viscous damping reveals that support conditions of the cable anchors, force tracking errors in the actual MR damper force, energy spillover to higher modes, and excitation and sensor cables hanging on the stay cable must be taken into consideration for the interpretation of the identified cable damping values. PMID:26167537

Broadband EIT borehole measurements with high phase accuracy using numerical corrections of electromagnetic coupling effects

NASA Astrophysics Data System (ADS)

Zhao, Y.; Zimmermann, E.; Huisman, J. A.; Treichel, A.; Wolters, B.; van Waasen, S.; Kemna, A.

2013-08-01

Electrical impedance tomography (EIT) is gaining importance in the field of geophysics and there is increasing interest for accurate borehole EIT measurements in a broad frequency range (mHz to kHz) in order to study subsurface properties. To characterize weakly polarizable soils and sediments with EIT, high phase accuracy is required. Typically, long electrode cables are used for borehole measurements. However, this may lead to undesired electromagnetic coupling effects associated with the inductive coupling between the double wire pairs for current injection and potential measurement and the capacitive coupling between the electrically conductive shield of the cable and the electrically conductive environment surrounding the electrode cables. Depending on the electrical properties of the subsurface and the measured transfer impedances, both coupling effects can cause large phase errors that have typically limited the frequency bandwidth of field EIT measurements to the mHz to Hz range. The aim of this paper is to develop numerical corrections for these phase errors. To this end, the inductive coupling effect was modeled using electronic circuit models, and the capacitive coupling effect was modeled by integrating discrete capacitances in the electrical forward model describing the EIT measurement process. The correction methods were successfully verified with measurements under controlled conditions in a water-filled rain barrel, where a high phase accuracy of 0.8 mrad in the frequency range up to 10 kHz was achieved. The corrections were also applied to field EIT measurements made using a 25 m long EIT borehole chain with eight electrodes and an electrode separation of 1 m. The results of a 1D inversion of these measurements showed that the correction methods increased the measurement accuracy considerably. It was concluded that the proposed correction methods enlarge the bandwidth of the field EIT measurement system, and that accurate EIT measurements can now be made in the mHz to kHz frequency range. This increased accuracy in the kHz range will allow a more accurate field characterization of the complex electrical conductivity of soils and sediments, which may lead to the improved estimation of saturated hydraulic conductivity from electrical properties. Although the correction methods have been developed for a custom-made EIT system, they also have potential to improve the phase accuracy of EIT measurements made with commercial systems relying on multicore cables.

Comparison study of cable geometries and superconducting tape layouts for high-temperature superconductor cables

NASA Astrophysics Data System (ADS)

Ta, Wurui; Shao, Tianchong; Gao, Yuanwen

2018-04-01

High-temperature superconductor (HTS) rare-earth-barium-copper-oxide (REBCO) tapes are very promising for use in high-current cables. The cable geometry and the layout of the superconducting tapes are directly related to the performance of the HTS cable. In this paper, we use numerical methods to perform a comparison study of multiple-stage twisted stacked-tape cable (TSTC) conductors to find better cable structures that can both improve the critical current and minimize the alternating current (AC) losses of the cable. The sub-cable geometry is designed to have a stair-step shape. Three superconducting tape layouts are chosen and their transport performance and AC losses are evaluated. The magnetic field and current density profiles of the cables are obtained. The results show that arrangement of the superconducting tapes from the interior towards the exterior of the cable based on their critical current values in descending order can enhance the cable's transport capacity while significantly reducing the AC losses. These results imply that cable transport capacity improvements can be achieved by arranging the superconducting tapes in a manner consistent with the electromagnetic field distribution. Through comparison of the critical currents and AC losses of four types of HTS cables, we determine the best structural choice among these cables.

The Role of Interfaces in Polyethylene/Metal-Oxide Nanocomposites for Ultrahigh-Voltage Insulating Materials.

PubMed

Pourrahimi, Amir Masoud; Olsson, Richard T; Hedenqvist, Mikael S

2018-01-01

Recent progress in the development of polyethylene/metal-oxide nanocomposites for extruded high-voltage direct-current (HVDC) cables with ultrahigh electric insulation properties is presented. This is a promising technology with the potential of raising the upper voltage limit in today's underground/submarine cables, based on pristine polyethylene, to levels where the loss of energy during electric power transmission becomes low enough to ensure intercontinental electric power transmission. The development of HVDC insulating materials together with the impact of the interface between the particles and the polymer on the nanocomposites electric properties are shown. Important parameters from the atomic to the microlevel, such as interfacial chemistry, interfacial area, and degree of particle dispersion/aggregation, are discussed. This work is placed in perspective with important work by others, and suggested mechanisms for improved insulation using nanoparticles, such as increased charge trap density, adsorption of impurities/ions, and induced particle dipole moments are considered. The effects of the nanoparticles and of their interfacial structures on the mechanical properties and the implications of cavitation on the electric properties are also discussed. Although the main interest in improving the properties of insulating polymers has been on the use of nanoparticles, leading to nanodielectrics, it is pointed out here that larger microscopic hierarchical metal-oxide particles with high surface porosity also impart good insulation properties. The impact of the type of particle and its inherent properties (purity and conductivity) on the nanocomposite dielectric and insulating properties are also discussed based on data obtained by a newly developed technique to directly observe the charge distribution on a nanometer scale in the nanocomposite. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystal River 3 Cable Materials for Thermal and Gamma Radiation Aging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fifield, Leonard S.; Correa, Miguel; Zwoster, Andy

The Expanded Materials Degradation Assessment Volume 5: Aging of Cables and Cable Systems (EMDA) summarizes the state of knowledge of materials, constructions, operating environments, and aging behavior of low voltage and medium cables in nuclear power plants (NPPs) and identifies potential knowledge gaps with regard to cable operation beyond 60 years. The greatest area of uncertainty relates to how well the accelerated aging used in the original equipment qualification (EQ) processes predicts the performance of cable materials in extended operation. General opinion and utility experience have indicated that actual operating environments of in-plant cables are not as severe, however, asmore » the operating and design basis environments used in the qualification process. Better understanding of the long term aging behavior of cable insulation materials in service conditions and the analysis of actual cable operating environments are the objectives of ongoing research to support subsequent license renewal activities in particular and long term cable aging management in general. A key component of the effort to better understand cable material aging behavior is the availability of representative samples of cables that have been installed in operating light water reactors and have experienced long term service. Unique access to long term service cables, including relatively rich information on cable identity and history, occurred in 2016 through the assistance of the Electric Power Research Institute (EPRI). EPRI facilitated DOE receipt of harvested cables from the decommissioned Crystal River Unit 3 (CR3) pressurized water reactor representing six of the nine most common low voltage cable manufacturers (EPRI 103841R1): Rockbestos, Anaconda Wire and Cable Company (Anaconda), Boston Insulated Wire (BIW), Brand-Rex, Kerite and Okonite. Cable samples received had been installed in the operating plant for durations ranging from 10 years to 36 years. These cables provide the opportunity to assess actual in-plant material aging and compare it to the expectations for service aging implied in original equipment qualification. The received samples are from cables manufactured as early as 1971 and as late as 1998. Of the original manufacturers, BIW, Anaconda and Kerite no longer supply low-voltage cables to the nuclear industry. Okonite, Rockbestos, and Brand-Rex do still supply nuclear-grade low-voltage cables, but most cable insulation formulations have changed over the years. Thus the availability of the CR3 samples representative of cables installed in existing U.S. NPPs also presents the opportunity for additional aging studies on the most relevant insulation and jacketing materials. This report describes the cables received from CR3 through EPRI assistance, some of the specific knowledge gaps that study of these cable materials can be used to address, and experimental plans for addressing those gaps using these materials. Harvested cables from CR3 and other NPPs that have experienced long term service, new old stock cables (manufactured before 2000, but never put in service), and relevant modern nuclear cables and materials from cable manufacturers are enabling research to address identified knowledge gaps and better understand long term aging behavior for cable materials currently installed in NPPs. This research, combined with refined understanding of actual service environments and conditions, will both support subsequent licensing activities and more efficient plant cable aging management.« less

Cable load sensing device

DOEpatents

Beus, Michael J.; McCoy, William G.

1998-01-01

Apparatus for sensing the magnitude of a load on a cable as the cable is employed to support the load includes a beam structure clamped to the cable so that a length of the cable lies along the beam structure. A spacer associated with the beam structure forces a slight curvature in a portion of the length of cable under a cable "no-load" condition so that the portion of the length of cable is spaced from the beam structure to define a cable curved portion. A strain gauge circuit including strain gauges is secured to the beam structure by welding. As the cable is employed to support a load the load causes the cable curved portion to exert a force normal to the cable through the spacer and on the beam structure to deform the beam structure as the cable curved portion attempts to straighten under the load. As this deformation takes place, the resistance of the strain gauges is set to a value proportional to the magnitude of the normal strain on the beam structure during such deformation. The magnitude of the normal strain is manipulated in a control device to generate a value equal to the magnitude or weight of the load supported by the cable.

Performance of Passive Samplers for Monitoring Estuarine Water Column Concentrations: 2. Emerging Contaminants

EPA Science Inventory

Measuring dissolved concentrations of emerging contaminants, such as polybrominated diphenyl ethers (PBDEs) and triclosan (TCS), can be challenging due to their physicochemical properties resulting in low aqueous solubilities and association with particles. Passive sampling meth...

13 CFR 120.131 - Leasing part of new construction or existing building to another business.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... If the Borrower is an Eligible Passive Company which leases 100 percent of the new building's space... than 51 percent of the Rentable Property. If the Borrower is an Eligible Passive Company which leases...

Braided tubular superelastic cables provide improved spinal stability compared to multifilament sublaminar cables.

PubMed

Tremblay, Jaëlle; Mac-Thiong, Jean-Marc; Brailovski, Vladimir; Petit, Yvan

2015-09-01

This study investigates the use of braided tubular superelastic cables, previously used for sternum closure following sternotomy, as sublaminar fixation method. It compares the biomechanical performance of spinal instrumentation fixation systems with regular sublaminar cables and proprietary superelastic cables. A hybrid experimental protocol was applied to six porcine L1-L4 spinal segments to compare multifilament sublaminar cables (Atlas, Medtronic Sofamor Danek, Memphis, TN) with proprietary superelastic cables. First, intact total range of motion was determined for all specimens using pure moment loading. Second, pure moments were imposed to the instrumented specimens until these intact total ranges of motion were reproduced. Compared to the intact specimens, the use of superelastic cables resulted in stiffer instrumented specimens than the use of multifilament cables for all the loading modes except axial torsion. Consequently, the superelastic cables limited the instrumented segments mobility more than the multifilament cables. Spinal instrumentation fixation systems using superelastic cables could be a good alternative to conventional sublaminar cables as it maintains a constant stabilization of the spine during loading. © IMechE 2015.

Stable High-Performance Perovskite Solar Cells via Grain Boundary Passivation.

PubMed

Niu, Tianqi; Lu, Jing; Munir, Rahim; Li, Jianbo; Barrit, Dounya; Zhang, Xu; Hu, Hanlin; Yang, Zhou; Amassian, Aram; Zhao, Kui; Liu, Shengzhong Frank

2018-04-01

The trap states at grain boundaries (GBs) within polycrystalline perovskite films deteriorate their optoelectronic properties, making GB engineering particularly important for stable high-performance optoelectronic devices. It is demonstrated that trap states within bulk films can be effectively passivated by semiconducting molecules with Lewis acid or base functional groups. The perovskite crystallization kinetics are studied using in situ synchrotron-based grazing-incidence X-ray scattering to explore the film formation mechanism. A model of the passivation mechanism is proposed to understand how the molecules simultaneously passivate the Pb-I antisite defects and vacancies created by under-coordinated Pb atoms. In addition, it also explains how the energy offset between the semiconducting molecules and the perovskite influences trap states and intergrain carrier transport. The superior optoelectronic properties are attained by optimizing the molecular passivation treatments. These benefits are translated into significant enhancements of the power conversion efficiencies to 19.3%, as well as improved environmental and thermal stability of solar cells. The passivated devices without encapsulation degrade only by ≈13% after 40 d of exposure in 50% relative humidity at room temperature, and only ≈10% after 24 h at 80 °C in controlled environment. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Molecule–Surface Reaction Mechanism on the Electronic Characteristics and Photovoltaic Performance of Molecularly Modified Si

PubMed Central

2013-01-01

We report on the passivation properties of molecularly modified, oxide-free Si(111) surfaces. The reaction of 1-alcohol with the H-passivated Si(111) surface can follow two possible paths, nucleophilic substitution (SN) and radical chain reaction (RCR), depending on adsorption conditions. Moderate heating leads to the SN reaction, whereas with UV irradiation RCR dominates, with SN as a secondary path. We show that the site-sensitive SN reaction leads to better electrical passivation, as indicated by smaller surface band bending and a longer lifetime of minority carriers. However, the surface-insensitive RCR reaction leads to more dense monolayers and, therefore, to much better chemical stability, with lasting protection of the Si surface against oxidation. Thus, our study reveals an inherent dissonance between electrical and chemical passivation. Alkoxy monolayers, formed under UV irradiation, benefit, though, from both chemical and electronic passivation because under these conditions both SN and RCR occur. This is reflected in longer minority carrier lifetimes, lower reverse currents in the dark, and improved photovoltaic performance, over what is obtained if only one of the mechanisms operates. These results show how chemical kinetics and reaction paths impact electronic properties at the device level. It further suggests an approach for effective passivation of other semiconductors. PMID:24205409

System for stabilizing cable phase delay utilizing a coaxial cable under pressure

NASA Technical Reports Server (NTRS)

Clements, P. A. (Inventor)

1974-01-01

Stabilizing the phase delay of signals passing through a pressurizable coaxial cable is disclosed. Signals from an appropriate source at a selected frequency, e.g., 100 MHz, are sent through the controlled cable from a first cable end to a second cable end which, electrically, is open or heavily mismatched at 100 MHz, thereby reflecting 100 MHz signals back to the first cable end. Thereat, the phase difference between the reflected-back signals and the signals from the source is detected by a phase detector. The output of the latter is used to control the flow of gas to or from the cable, thereby controlling the cable pressure, which in turn affects the cable phase delay.

Fire related hazards of cables: The Canadian position development of fire resistant inside wiring cable

NASA Astrophysics Data System (ADS)

Hartley, M. D.; Jaques, R. E.

1986-11-01

The Canadian Electrical Code and the National Building Code in Canada recognize only two designations in regards to fire resistance of cables; cables for use in combustible (residential) buildings and cables for use in non-combustible buildings. The Test standard for cables for non-combustible buildings resembles IEEE-383. However, it is more severe; particularly for small nonarmoured cables such as Inside Wiring Cable. This forthcoming requirement has necessitated material and product development. Although an Inside Wiring cable modification of both insulation and jacket was undertaken, the large volume fraction of combustible material in the jacket vis a vis the insulation made it the area of greatest impact. The paper outlines the development and its effect on cable performance.

Modal resonant dynamics of cables with a flexible support: A modulated diffraction problem

NASA Astrophysics Data System (ADS)

Guo, Tieding; Kang, Houjun; Wang, Lianhua; Liu, Qijian; Zhao, Yueyu

2018-06-01

Modal resonant dynamics of cables with a flexible support is defined as a modulated (wave) diffraction problem, and investigated by asymptotic expansions of the cable-support coupled system. The support-cable mass ratio, which is usually very large, turns out to be the key parameter for characterizing cable-support dynamic interactions. By treating the mass ratio's inverse as a small perturbation parameter and scaling the cable tension properly, both cable's modal resonant dynamics and the flexible support dynamics are asymptotically reduced by using multiple scale expansions, leading finally to a reduced cable-support coupled model (i.e., on a slow time scale). After numerical validations of the reduced coupled model, cable-support coupled responses and the flexible support induced coupling effects on the cable, are both fully investigated, based upon the reduced model. More explicitly, the dynamic effects on the cable's nonlinear frequency and force responses, caused by the support-cable mass ratio, the resonant detuning parameter and the support damping, are carefully evaluated.

Computational methods for the control of distributed parameter systems

NASA Technical Reports Server (NTRS)

Burns, J. A.; Cliff, E. M.; Powers, R. K.

1985-01-01

It is shown that care must be taken to ensure that finite dimensional approximations of distributed parameter systems preserve important system properties (i.e., controllability, observability, stabilizability, detectability, etc.). It is noted that, if the particular scheme used to construct the finite dimensional model does not take into account these system properties, the model may not be suitable for control design and analysis. These ideas are illustrated by a simple example, i.e., a cable-spring-mass system.

105. VIEW NORTH FROM SLC3W CABLE TUNNEL INTO CABLE VAULT ...

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

105. VIEW NORTH FROM SLC-3W CABLE TUNNEL INTO CABLE VAULT AND SLC-3E CABLE TUNNEL. NOTE WOODEN PLANKING ON FLOOR OF TUNNEL AND CABLE TRAYS LINING TUNNEL WALLS. STAIRS ON EAST WALL OF CABLE VAULT LEAD INTO LANDLINE INSTRUMENTATION ROOM. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Frequency domain reflectometry NDE for aging cables in nuclear power plants

NASA Astrophysics Data System (ADS)

Glass, S. W.; Jones, A. M.; Fifield, L. S.; Hartman, T. S.

2017-02-01

Degradation of the cable jacket, electrical insulation, and other cable components of installed cables within nuclear power plants (NPPs) is known to occur as a function of age, temperature, radiation, and other environmental factors. Although system tests verify cable function under normal loads, demonstration of some cable's ability to perform under exceptional loads associated with design-basis events is essential to assuring plant integrity. The cable's ability to perform safely over the initial 40-year planned and licensed life has generally been demonstrated and there have been very few age-related cable failures. With greater than 1000 km of power, control, instrumentation, and other cables typically found in an NPP, replacing all the cables would be a severe cost burden. Justification for life extension to 60 and 80 years requires a cable aging management program that includes condition monitoring to justify cable performance under normal operation as well as accident conditions. A variety of tests are available to assess various aspects of electrical and mechanical cable performance, but none are suitable for all cable configurations nor does any single test confirm all features of interest. One particularly promising test that is beginning to be used more and more by utilities is frequency domain reflectometry (FDR). FDR is a nondestructive electrical inspection technique used to detect and localize faults in power and communication system conductors along the length of a cable from a single connection point. FDR detects discontinuities in the electrical impedance that arise due to cable splices or similar changes along the path of the conductor pair. In addition, FDR has the potential to provide sensitivity to insulation degradation by detecting small changes in impedance between the cable conductors being examined. The technique is also sensitive to cable bends, the particular lay of the cable in tray, proximity to other cable, and other factors that bear consideration when interpreting the test results. This paper examines various influences on the FDR approach and compares results of three different instruments to assess accelerated aging damage among several NPP representative cables.

The Cables Gene on Chromosome 18q Is Silenced by Promoter Hypermethylation and Allelic Loss in Human Colorectal Cancer

PubMed Central

Park, Do Youn; Sakamoto, Hideo; Kirley, Sandra D.; Ogino, Shuji; Kawasaki, Takako; Kwon, Eunjeong; Mino-Kenudson, Mari; Lauwers, Gregory Y.; Chung, Daniel C.; Rueda, Bo R.; Zukerberg, Lawrence R.

2007-01-01

Cables is a cyclin-dependent kinase-binding nuclear protein that maps to chromosome 18q11-12. Here, we assessed Cables expression in 160 colorectal cancers (CRCs), its role in colon cancer cell growth, and the potential mechanisms of Cables inactivation. Expression levels, promoter methylation, and mutational status of Cables were investigated in colon cancer cell lines and primary colon tumors. Chromosome 18q loss of heterozygosity (LOH) was evaluated with multiple polymorphic markers. Cables inhibited cellular proliferation and colony formation in colon cancer cell lines. Cables expression was reduced in 65% of primary CRCs. No mutations were detected in 10 exons of Cables in 20 primary colon tumors. Cables promoter was methylated in cell lines with decreased Cables expression and vice versa. 5-Aza-2′-deoxycytidine resulted in increased Cables expression in methylated cell lines. There was a significant correlation between promoter methylation and Cables gene expression in primary colon tumors. Sixty-five percent of primary colon tumors demonstrated chromosome 18q LOH. LOH involving the Cables region was observed in 35% of cases, including those in which more distal portions of chromosome 18q were retained, and Cables expression was decreased in all such cases. Loss of Cables expression in 65% of CRCs suggests that it is a common event in colonic carcinogenesis, with promoter methylation and LOH appearing to be important mechanisms of Cables gene inactivation. PMID:17982127

Investigation of cables for ionization chambers.

PubMed

Spokas, J J; Meeker, R D

1980-01-01

Seven coaxial cables which are in use for carrying currents generated in ionization chambers have been critically studied with reference to their suitability to this application. Included in this study are four low-noise triaxial cables and three low-noise two-conductor cables. For each cable the following characteristics were considered: inherent noise currents, currents produced by cable movements, polarization currents, the degree of electrostatic shielding of the central signal-carrying conductor, and radiation-induced cable currents. The study indicated that of the seven cables, two low-noise triaxial cables, both employing solid Teflon dielectric surrounding the central conductor, appear to offer the best overall performance for use with ionization chambers.

An Internal Coaxial Cable Electrical Connector For Use In Downhole Tools

DOEpatents

Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron; Briscoe, Michael

2005-11-29

A coaxial cable electrical connector more specifically an internal coaxial cable connector placed within a coaxial cable and its constituent components. A coaxial cable connector is in electrical communcation with an inductive transformer and a coaxial cable. The connector is in electrical communication with the outer housing of the inductive transfonner. A generally coaxial center conductor, a portion of which could be the coil in the inductive transformer, passes through the connector, is electrically insulated from the connector, and is in electrical communication with the conductive care of the coaxial cable. A plurality of bulbous pliant tabs on the coaxial cable connector mechanically engage the inside diameter of the coaxial cable thus grounding the transformer to the coaxial cable. The coaxial cable and inductive transformer are disposed within downhole tools to transmit electrical signals between downhole tools within a drill string.

High power cable with internal water cooling 400 kV

NASA Astrophysics Data System (ADS)

Rasquin, W.; Harjes, B.

1982-08-01

Due to the concentration of electricity production in large power plants, the need of higher power transmissions, and the protection of environment, developement of a 400 kV water cooled cable in the power range of 1 to 5 GVA was undertaken. The fabrication and testing of equipment, engineering of cable components, fabrication of a test cable, development of cable terminal laboratory, testing of test cable, field testing of test cable, fabrication of industrial cable laboratory, testing of industrial cable, field testing of industrial cable, and system analysis for optimization were prepared. The field testing was impossible to realize. However, it is proved that a cable consisting of an internal stainless steel water cooled tube, covered by stranded copper profiles, insulated with heavy high quality paper, and protected by an aluminum cover can be produced, withstand tests accordingly to IEC/VDE recommendations, and is able to fulfill all exploitation conditions.

30 CFR 7.403 - Application requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Cables, Signaling Cables, and Cable Splice Kits § 7.403 Application requirements. (a) Electric cables and signaling cables. A single... product: (1) Product information: (i) Cable type (for example, G or G-GC). (ii) Construction (for example...

30 CFR 7.403 - Application requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Cables, Signaling Cables, and Cable Splice Kits § 7.403 Application requirements. (a) Electric cables and signaling cables. A single... product: (1) Product information: (i) Cable type (for example, G or G-GC). (ii) Construction (for example...

30 CFR 7.403 - Application requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Cables, Signaling Cables, and Cable Splice Kits § 7.403 Application requirements. (a) Electric cables and signaling cables. A single... product: (1) Product information: (i) Cable type (for example, G or G-GC). (ii) Construction (for example...

Effect of oxygen concentration on fire growth of various types of cable bending in horizontal and vertical orientations

NASA Astrophysics Data System (ADS)

Pangaribuan, Adrianus; Dhiputra, I. M. K.; Nugroho, Yulianto S.

2017-03-01

Electrical cable is a whole of the material including metal (cooper) conductor and its insulation, when an electrical cable is flowed by electric current, based on its own capacity, the temperature of cable conductor increases gradually. If the current flows above the cable carrying capacity, then an extreme temperature rises are expected. When temperature increase, the electric current flow inside cable conductor will decrease gradually related to the resistance and could occur repeatedly in a period. Since electrical faults on electrical cable system are often suspected as the cause of fires, thus this research aims to investigate measures of preventing the fire to start by means of controlling oxygen concentration in a cable compartment. The experimental work was conducted in laboratory by using electrical power cable of 1.5 mm2 size. Two transparent chambers were applied for studying the effect of vertical and horizontal orientations on the cable temperature rise, under various oxygen concentration of the gas streams. In the present work, the electrical was maintained at a constant level during a typical test run. Parametric studies reported in the paper include the use of a bare and insulated cables as well as the bending shape of the cable lines of a straight cable, coiled cable and randomly bent cable which were loaded with the same electric load and oxygen concentration in the gas supply.

The Over-Selling of Fiber Optics? Cable Planning for Educational Technology.

ERIC Educational Resources Information Center

Kovacs, Robert E.

1993-01-01

Describes fiber optic cables and coaxial cables and considers when each would be appropriate for educational technology. Single mode versus multimode fiber optics are explained, advantages and disadvantages of each type of cable are discussed, and guidelines for choosing fiber optic cables and coaxial cables are offered. (LRW)

Helical grip for the cable cars of San Francisco

NASA Technical Reports Server (NTRS)

Peyran, R. J.

1979-01-01

A helical cable car grip to minimize high maintenance costs of San Francisco's cable car operation is presented. The grip establishes a rolling contact between the cable and grip to reduce sliding friction and associated cable wear. The design, development, and testing of the helical cable car grip are described.

47 CFR 76.1001 - Unfair practices generally.

Code of Federal Regulations, 2012 CFR

2012-10-01

... control with a cable operator or cable operators, satellite cable programming vendor or vendors in which a... under common control with, such terrestrial cable programming vendor shall be deemed responsible for... programming vendor is wholly owned by, controlled by, or under common control with a cable operator or cable...

14 CFR 25.689 - Cable systems.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.689 Cable systems. (a) Each cable, cable fitting, turnbuckle, splice, and pulley must be approved. In addition— (1) No cable... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Cable systems. 25.689 Section 25.689...

47 CFR 76.1001 - Unfair practices generally.

Code of Federal Regulations, 2014 CFR

2014-10-01

... control with a cable operator or cable operators, satellite cable programming vendor or vendors in which a... under common control with, such terrestrial cable programming vendor shall be deemed responsible for... programming vendor is wholly owned by, controlled by, or under common control with a cable operator or cable...

47 CFR 76.1001 - Unfair practices generally.

Code of Federal Regulations, 2013 CFR

2013-10-01

... control with a cable operator or cable operators, satellite cable programming vendor or vendors in which a... under common control with, such terrestrial cable programming vendor shall be deemed responsible for... programming vendor is wholly owned by, controlled by, or under common control with a cable operator or cable...

30 CFR 57.12014 - Handling energized power cables.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Handling energized power cables. 57.12014... Electricity Surface and Underground § 57.12014 Handling energized power cables. Power cables energized to.... This does not prohibit pulling or dragging of cable by the equipment it powers when the cable is...

30 CFR 57.12014 - Handling energized power cables.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Handling energized power cables. 57.12014... Electricity Surface and Underground § 57.12014 Handling energized power cables. Power cables energized to.... This does not prohibit pulling or dragging of cable by the equipment it powers when the cable is...

30 CFR 57.12014 - Handling energized power cables.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Handling energized power cables. 57.12014... Electricity Surface and Underground § 57.12014 Handling energized power cables. Power cables energized to.... This does not prohibit pulling or dragging of cable by the equipment it powers when the cable is...

30 CFR 57.12014 - Handling energized power cables.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Handling energized power cables. 57.12014... Electricity Surface and Underground § 57.12014 Handling energized power cables. Power cables energized to.... This does not prohibit pulling or dragging of cable by the equipment it powers when the cable is...

30 CFR 57.12014 - Handling energized power cables.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Handling energized power cables. 57.12014... Electricity Surface and Underground § 57.12014 Handling energized power cables. Power cables energized to.... This does not prohibit pulling or dragging of cable by the equipment it powers when the cable is...

14 CFR 29.685 - Control system details.

Code of Federal Regulations, 2010 CFR

2010-01-01

... must be means to prevent the slapping of cables or tubes against other parts. (d) Cable systems must be designed as follows: (1) Cables, cable fittings, turnbuckles, splices, and pulleys must be of an acceptable kind. (2) The design of cable systems must prevent any hazardous change in cable tension throughout the...

14 CFR 27.685 - Control system details.

Code of Federal Regulations, 2010 CFR

2010-01-01

... must be means to prevent the slapping of cables or tubes against other parts. (d) Cable systems must be designed as follows: (1) Cables, cable fittings, turnbuckles, splices, and pulleys must be of an acceptable kind. (2) The design of the cable systems must prevent any hazardous change in cable tension throughout...

Actin cable dynamics in budding yeast

PubMed Central

Yang, Hyeong-Cheol; Pon, Liza A.

2002-01-01

Actin cables, bundles of actin filaments that align along the long axis of budding yeast, are crucial for establishment of cell polarity. We fused green fluorescent protein (GFP) to actin binding protein 140 (Abp140p) and visualized actin cable dynamics in living yeast. We detected two populations of actin cables: (i) bud-associated cables, which extend from the bud along the mother-bud axis, and (ii) randomly oriented cables, which are relatively short. Time-lapse imaging of Abp140p–GFP revealed an apparent increase in the length of bud-associated actin cables. Analysis of movement of Abp140p–GFP fiduciary marks on bud-associated cables and fluorescence loss in photobleaching experiments revealed that this apparent elongation occurs by assembly of new material at the end of the cable within the bud and movement of the opposite end of the cable toward the tip of the mother cell distal to the bud. The rate of extension of the tip of an elongating actin cable is 0.29 ± 0.08 μm/s. Latrunculin A (Lat-A) treatment completely blocked this process. We also observed movement of randomly oriented cables around the cortex of cells at a rate of 0.59 ± 0.14 μm/s. Mild treatment with Lat-A did not affect the velocity of movement of randomly oriented cables. However, Lat-A treatment did increase the number of randomly oriented, motile cables per cell. Our observations suggest that establishment of bud-associated actin cables during the cell cycle is accomplished not by realignment of existing cables but by assembly of new cables within the bud or bud neck, followed by elongation. PMID:11805329

A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges

PubMed Central

Asgari, B.; Osman, S. A.; Adnan, A.

2014-01-01

Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method. PMID:25050400

A new multiconstraint method for determining the optimal cable stresses in cable-stayed bridges.

PubMed

Asgari, B; Osman, S A; Adnan, A

2014-01-01

Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

Si{sub 3}N{sub 4} layers for the in-situ passivation of GaN-based HEMT structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yunin, P. A., E-mail: yunin@ipmras.ru; Drozdov, Yu. N.; Drozdov, M. N.

2015-11-15

A method for the in situ passivation of GaN-based structures with silicon nitride in the growth chamber of a metal organic vapor phase epitaxy (MOVPE) reactor is described. The structural and electrical properties of the obtained layers are investigated. The in situ and ex situ passivation of transistor structures with silicon nitride in an electron-beam-evaporation device are compared. It is shown that ex situ passivation changes neither the initial carrier concentration nor the mobility. In situ passivation makes it possible to protect the structure surface against uncontrollable degradation upon the finishing of growth and extraction to atmosphere. In the inmore » situ passivated structure, the carrier concentration increases and the mobility decreases. This effect should be taken into account when manufacturing passivated GaN-based transistor structures.« less

ATOC/Pioneer Seamount cable after 8 years on the seafloor: Observations, environmental impact

NASA Astrophysics Data System (ADS)

Kogan, Irina; Paull, Charles K.; Kuhnz, Linda A.; Burton, Erica J.; von Thun, Susan; Gary Greene, H.; Barry, James P.

2006-04-01

A study was conducted on the impacts of the presence of the Acoustic Thermometry of Ocean Climate (ATOC)/Pioneer Seamount cable on the benthos from nearshore waters adjacent to its origin at Pillar Point Air Force Station in Half Moon Bay, California to its terminus 95 km along its length on Pioneer Seamount. The coaxial Type SD cable was installed, unburied on the seafloor in 1995. Thirteen sites along the cable route were surveyed using the Monterey Bay Aquarium Research Institute (MBARI) ROVs Ventana and Tiburon equipped with cable-tracking tools. Quantitative comparisons of biological communities and seafloor features between cable and control sites were performed at nine stations. Forty-two hours of video footage and 138 push cores were collected over 15.1 km of seafloor. Approximately 12.1 km of the cable was observed (13% of the cable route). This study documents the appearance and condition of the cable and the underlying seafloor, and the effects of the cable on biological communities along its route. Limited self-burial of the cable has occurred during the 8-year deployment, particularly over the continental shelf and upper slope. Cable strumming by nearshore wave action has incised rocky siltstone outcrops. Several observations of kinks and snags in the cable on the upper slope (˜240 m depth) suggest contact with trawling gear. Few changes in the abundance or distribution of benthic fauna were detectable from video observations (epifaunal) and sediment core samples (infauna). Of 17 megafaunal groups and 19 infaunal taxa, no tests evaluating the overall effect of the cable were statistically significant. While these results indicate that the biological impacts of the cable are minor at most, three megafaunal groups exhibited cable-related changes at one or more stations. Actiniarians (sea anemones) colonized the cable when it was exposed on the seafloor, and were therefore generally more abundant on the cable than in surrounding, sediment-dominated seafloor habitats. Some fishes were also more abundant near the cable, apparently due to the higher habitat complexity provided by the cable. The study also documents general changes in the benthos across the Central California continental margin.

Burning Characteristics and Flammability of PVC Cables in Groups

NASA Technical Reports Server (NTRS)

Mikado, T.; Akita, K.

1988-01-01

Because burning cables represent a danger of increasing secondary damage it is of utmost importance for disaster prevention to correctly evaluate the combustion characteristics of cable. However, in many cases cable is laid out in bundles complicating the combustion characteristics. A situation has developed where group cable characteristics are not completely understood. A new method is developed for testing the combustion of high polymer type cable and earlier reports gave comparative combustion measurement results. It was learned that there is considerable difference between the combustion characteristics of the grouped cables and those of single cables. This study is supplemental research concerning the special behavior of group PVC cables, throwing some light on their combustion characteristics.

System for effecting underwater coupling of optical fiber cables characterized by a novel V-probe cable capture mechanism

NASA Astrophysics Data System (ADS)

Hillenbrand, Christopher F.; Barron, Thomas D.; Nugent, David M.

1995-03-01

A submarine trails one fiber optic cable and an undersea vehicle is controlled by this first cable. A missile/torpedo trails a second cable that is to be coupled to the first cable. The second cable has a segment suspended vertically underwater between a buoyant pod and a sea anchor type buoy. The undersea vehicle, or Autonomous Undersea Vehicle, (AUV) hunts for the pod by conventional homing means. A forked cable pickup device in the nose of the AUV captures the suspended cable segment directing it into a slot so a male socket in the underside of the pod mates with a female socket in the slot.

47 CFR 32.2422 - Underground cable.

Code of Federal Regulations, 2013 CFR

2013-10-01

... cable. This subsidiary record category shall include the original cost of optical fiber cable and other..., Buried Cable. (d) The cost of cables leading from the main distributing frame or equivalent to central...

47 CFR 32.2422 - Underground cable.

Code of Federal Regulations, 2010 CFR

2010-10-01

... cable. This subsidiary record category shall include the original cost of optical fiber cable and other..., Buried Cable. (d) The cost of cables leading from the main distributing frame or equivalent to central...

47 CFR 32.2422 - Underground cable.

Code of Federal Regulations, 2014 CFR

2014-10-01

... cable. This subsidiary record category shall include the original cost of optical fiber cable and other..., Buried Cable. (d) The cost of cables leading from the main distributing frame or equivalent to central...

47 CFR 32.2422 - Underground cable.

Code of Federal Regulations, 2011 CFR

2011-10-01

... cable. This subsidiary record category shall include the original cost of optical fiber cable and other..., Buried Cable. (d) The cost of cables leading from the main distributing frame or equivalent to central...

47 CFR 32.2422 - Underground cable.

Code of Federal Regulations, 2012 CFR

2012-10-01

... cable. This subsidiary record category shall include the original cost of optical fiber cable and other..., Buried Cable. (d) The cost of cables leading from the main distributing frame or equivalent to central...

Horizontal-to-Vertical Spectral Ratio for Estimating Thickness of Sedimentary Deposits across the PoroTomo site in Brady Hot Springs, Nevada (USA)

NASA Astrophysics Data System (ADS)

Parker, L.; Fratta, D.; Zeng, X.; Lord, N. E.; Wang, H. F.; Thurber, C. H.; Lin, F. C.; Feigl, K. L.; Team, P.

2016-12-01

During March 2016, the PoroTomo research team deployed more than 8700 m of DAS and DTS cable in horizontal and vertical sensing arrays, 244 three-component surface geophones, inSAR images, pressure transducers, and a vibroseis truck to actively and passively image the response of a geothermal field in Brady Hot Springs, Nevada. During the imaging period the geothermal field was manipulated to change the pore pressure in the formation. The objective of the study is to invert for poroelastic parameters within a 1500 m by 500 m by 400 m volume using tomographic techniques. Among the different imaging techniques, the research team is using passive horizontal-to-vertical spectral ratio data captured with the three-component geophones to estimate the thickness of the sedimentary deposits across the PoroTomo site. The interpretation of the inverted data is complicated due the heterogeneity in the near surface deposits at the site. These deposits include diatomaceous earth, sandy/silty layers, and hardened silica associated with the presence of fumaroles. In spite of the challenges associated with deposits of very different stiffness, the mapping of sediment thickness across the Natural Laboratory helps constrain the inversion of Multiple Channel Analysis of Surface Waves to improve the quality of the solution images.

Stability analysis of an F/A-18 E/F cable mount m odel

NASA Technical Reports Server (NTRS)

Thompson, Nancy; Farmer, Moses

1994-01-01

A full-span F/A-18 E/F cable mounted wind tunnel model is part of a flutter clearance program at the NASA Langley Transonic Dynamics Tunnel. Parametric analysis of this model using GRUMCBL software was conducted to assess stability for wind tunnel tests. Two configurations of the F/A-18 E/F were examined. The parameters examined were pulley-cable friction, mach number, dynamic pressure, cable geometry, center of gravity location, cable tension, snubbing the model, drag, and test medium. For the nominal cable geometry (Cable Geometry 1), Configuration One was unstable for cases with higher pulley-cable friction coefficients. A new cable geometry (Cable Geometry 3) was determined in which Configuration One was stable for all cases evaluated. Configuration Two with the nominal center of gravity position was found to be unstable for cases with higher pulley-cable friction coefficients; however, the model was stable when the center of gravity moved forward 1/2. The model was tested using the cable mount system during the initial wind tunnel entry and was stable as predicted.

System for effecting underwater coupling of optical fiber cables characterized by a novel lateral arm cable capture mechanism

NASA Astrophysics Data System (ADS)

Hillenbrand, Christopher F.

1995-03-01

A submarine trails one fiber optic cable and an undersea vehicle is controlled by this first cable. A missile/torpedo trails a second cable that is to be coupled to the first cable. The second cable has a segment suspended vertically underwater between a buoyant pod and a sea anchor type buoy. The undersea vehicle, or autonomous undersea vehicle, (AUV) hunts for the pod by conventional homing components, and cable capturing arms on the vehicle direct the cable's movement relative to the vehicle into a pod mating position that achieves optical coupling of the two cables. In one embodiment two arms are pivotably mounted to the vehicle's sides so one arm captures the suspended cable segment directing it into a slot so a male socket in the underside of the pod mates with a female socket in the slot. Another embodiment accomplishes the same result with a device in which the arms are formed as the off-shoots of a forked cable pickup device in the nose of the AUV.

Performance and properties of arsenic passivated lithium-titanium disulfide cells

NASA Technical Reports Server (NTRS)

Yen, S. P. S.; Shen, D.; Fitzgerald, D.; Vasquez, R. P.; Somoano, R. B.

1986-01-01

In order to inhibit chemical degradation associated with the lithium-electrolyte interaction in ambient temperature lithium cells, an attempt was made to synthetically passivate the anode via ion implantation of arsenic. Solvent reduction is reduced although salt reaction with lithium is still present. The performance of the Li-TiS2 cell differs from those with standard electrodes, but further work is necessary to clarify the efficacy of this mode of passivation.

Cable Tester Box

NASA Technical Reports Server (NTRS)

Lee, Jason H.

2011-01-01

Cables are very important electrical devices that carry power and signals across multiple instruments. Any fault in a cable can easily result in a catastrophic outcome. Therefore, verifying that all cables are built to spec is a very important part of Electrical Integration Procedures. Currently, there are two methods used in lab for verifying cable connectivity. (1) Using a Break-Out Box and an ohmmeter this method is time-consuming but effective for custom cables and (2) Commercial Automated Cable Tester Boxes this method is fast, but to test custom cables often requires pre-programmed configuration files, and cables used on spacecraft are often uniquely designed for specific purposes. The idea is to develop a semi-automatic continuity tester that reduces human effort in cable testing, speeds up the electrical integration process, and ensures system safety. The JPL-Cable Tester Box is developed to check every single possible electrical connection in a cable in parallel. This system indicates connectivity through LED (light emitting diode) circuits. Users can choose to test any pin/shell (test node) with a single push of a button, and any other nodes that are shorted to the test node, even if they are in the same connector, will light up with the test node. The JPL-Cable Tester Boxes offers the following advantages: 1. Easy to use: The architecture is simple enough that it only takes 5 minutes for anyone to learn how operate the Cable Tester Box. No pre-programming and calibration are required, since this box only checks continuity. 2. Fast: The cable tester box checks all the possible electrical connections in parallel at a push of a button. If a cable normally takes half an hour to test, using the Cable Tester Box will improve the speed to as little as 60 seconds to complete. 3. Versatile: Multiple cable tester boxes can be used together. As long as all the boxes share the same electrical potential, any number of connectors can be tested together.

Radhard optical patchcords and packaging for satellites using liquid crystal polymers

NASA Astrophysics Data System (ADS)

O'Riorden, S.; Mahapatra, A.

2017-11-01

There are many advantages to employing fiber optics for high capacity satellite communication. However, optical cables can be susceptible to high radiation, temperature extremes and vacuum environment. Any hardware used in these systems must be rugged, durable and immune to the detrimental effects of the aforementioned conditions. Standard COTS optical fiber will darken when exposed to high levels of radiation limiting the effectiveness of the communications system. Of particular concern to satellites in GEO are energetic electrons, bursts of heavy particles due to solar storms which can cause total dose and single event effects (SEE). Conventional fiber optic cables have several issues performing in high radiation environments. Linden has patented and developed a novel cable using an extruded layer of Liquid Crystal Polymer (LCP) applied to commercially available fiber. Total dose effects are minimized by shielding with Liquid Crystal Polymer jacketing. It is a simple, inexpensive way to increase the radiation shielding and mechanical performance of cables in satellites while concomitantly providing hermeticity and thus increased fatigue factor for optical glass. • LCPs exposed to 5000 Mrad dose of gamma rays retain in excess of 90% of their mechanical properties. • LCPs exposed to 1 Mrad radiation dose with energetic protons retain almost 100% of their mechanical strength. Tensile modulus increases with exposure to the radiation. • Weight for weight the proton absorbing power of LCP is 25% better than that of aluminum. We will present experimental data on radhard optical patchcords.

Comparison of contemporary occipitocervical instrumentation techniques with and without C1 lateral mass screws.

PubMed

Wolfla, Christopher E; Salerno, Simon A; Yoganandan, Narayan; Pintar, Frank A

2007-09-01

This study was designed to test the kinematic properties of three occiput-C2 instrumentation constructs with and without supplemental rigid C1 fixation. The results are compared with intact specimens and with constructs incorporating contemporary cabling techniques. Five unembalmed human cadaver specimens underwent range of motion (ROM) testing in the intact condition, followed by destabilization with odontoid osteotomy. Destabilized specimens then underwent ROM testing with each of seven occipitocervical instrumentation constructs, all incorporating occipital screws: C1 and C2 sublaminar cables with cable connectors, C2 pars screws +/- C1 lateral mass screws, C2 lamina screws +/- C1 lateral mass screws, and C1-C2 transarticular screws +/- C1 lateral mass screws. All seven constructs demonstrated significantly lower ROM in all loading modes than intact specimens (P < 0.05). With a single exception, the addition of C1 lateral mass screws to the screw-based constructs produced no significant change in ROM in any of the loading modes. Compared with intact specimens, constructs anchored by C1-C2 transarticular screws demonstrated the greatest decrease in ROM, and those anchored by sublaminar cables demonstrated the least decrease in ROM. Any of the tested screw-based constructs are likely to provide adequate support for the patient with an unstable craniocervical junction. Therefore, the choice of construct should be based on anatomic considerations. The routine incorporation of C1 lateral mass screws into occipitocervical instrumentation constructs does not seem necessary.

HoloGondel: in situ cloud observations on a cable car in the Swiss Alps using a holographic imager

NASA Astrophysics Data System (ADS)

Beck, Alexander; Henneberger, Jan; Schöpfer, Sarah; Fugal, Jacob; Lohmann, Ulrike

2017-02-01

In situ observations of cloud properties in complex alpine terrain where research aircraft cannot sample are commonly conducted at mountain-top research stations and limited to single-point measurements. The HoloGondel platform overcomes this limitation by using a cable car to obtain vertical profiles of the microphysical and meteorological cloud parameters. The main component of the HoloGondel platform is the HOLographic Imager for Microscopic Objects (HOLIMO 3G), which uses digital in-line holography to image cloud particles. Based on two-dimensional images the microphysical cloud parameters for the size range from small cloud particles to large precipitation particles are obtained for the liquid and ice phase. The low traveling velocity of a cable car on the order of 10 m s-1 allows measurements with high spatial resolution; however, at the same time it leads to an unstable air speed towards the HoloGondel platform. Holographic cloud imagers, which have a sample volume that is independent of the air speed, are therefore well suited for measurements on a cable car. Example measurements of the vertical profiles observed in a liquid cloud and a mixed-phase cloud at the Eggishorn in the Swiss Alps in the winters 2015 and 2016 are presented. The HoloGondel platform reliably observes cloud droplets larger than 6.5 µm, partitions between cloud droplets and ice crystals for a size larger than 25 µm and obtains a statistically significantly size distribution for every 5 m in vertical ascent.

Thermal analysis of underground power cable system

NASA Astrophysics Data System (ADS)

Rerak, Monika; Ocłoń, Paweł

2017-10-01

The paper presents the application of Finite Element Method in thermal analysis of underground power cable system. The computations were performed for power cables buried in-line in the ground at a depth of 2 meters. The developed mathematical model allows determining the two-dimensional temperature distribution in the soil, thermal backfill and power cables. The simulations studied the effect of soil and cable backfill thermal conductivity on the maximum temperature of the cable conductor. Also, the effect of cable diameter on the temperature of cable core was studied. Numerical analyses were performed based on a program written in MATLAB.

DC attenuation meter

DOEpatents

Hargrove, Douglas L.

2004-09-14

A portable, hand-held meter used to measure direct current (DC) attenuation in low impedance electrical signal cables and signal attenuators. A DC voltage is applied to the signal input of the cable and feedback to the control circuit through the signal cable and attenuators. The control circuit adjusts the applied voltage to the cable until the feedback voltage equals the reference voltage. The "units" of applied voltage required at the cable input is the system attenuation value of the cable and attenuators, which makes this meter unique. The meter may be used to calibrate data signal cables, attenuators, and cable-attenuator assemblies.

Cable Communications Revolution. Future: Broadband Communications, Local Origination.

ERIC Educational Resources Information Center

Peters, Robert W.

The revolution in two-way broadband communications envisioned for the future includes remote access to libraries, interactive educational programing, shopping at home, personal and property security, and many other services limited only by man's imagination and his ability to deliver the service at a price the consumer is willing and able to pay.…

A Carbon Nanotube Cable for a Space Elevator

ERIC Educational Resources Information Center

Bochnícek, Zdenek

2013-01-01

In this paper the mechanical properties of carbon nanotubes are discussed in connection with the possibility to use them for the construction of a space elevator. From the fundamental information about the structure of a carbon nanotube and the chemical bond between carbon atoms, Young's modulus and the ultimate tensile strength are…

Nondestructive Examination for Nuclear Power Plant Cable Aging Management Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glass, Samuel W.; Fifield, Leonard S.

2016-01-01

Degradation of the cable jacket, electrical insulation, and other cable components of installed cables within nuclear power plants (NPPs) is known to occur as a function of age, temperature, radiation, and other environmental factors. System tests verify cable function under normal loads; however, the concern is over cable performance under exceptional loads associated with design-basis events (DBEs). The cable’s ability to perform safely over the initial 40 year planned and licensed life has generally been demonstrated and there have been very few age-related cable failures. With greater than 1000 km of power, control, instrumentation, and other cables typically found inmore » an NPP, replacing all the cables would be a severe cost burden. Justification for life extension to 60 and 80 years requires a cable aging management program (AMP) to justify cable performance under normal operation as well as accident conditions. This paper addresses various NDE technologies that constitute the essence of an acceptable aging management program.« less

Study on Elastic Helical TDR Sensing Cable for Distributed Deformation Detection

PubMed Central

Tong, Renyuan; Li, Ming; Li, Qing

2012-01-01

In order to detect distributed ground surface deformation, an elastic helical structure Time Domain Reflectometry (TDR) sensing cable is shown in this paper. This special sensing cable consists of three parts: a silicone rubber rope in the center; a couple of parallel wires coiling around the rope; a silicone rubber pipe covering the sensing cable. By analyzing the relationship between the impedance and the structure of the sensing cable, the impedance model shows that the sensing cable impedance will increase when the cable is stretched. This specific characteristic is verified in the cable stretching experiment which is the base of TDR sensing technology. The TDR experiment shows that a positive reflected signal is created at the stretching deformation point on the sensing cable. The results show that the deformation section length and the stretching elongation will both affect the amplitude of the reflected signal. Finally, the deformation locating experiments show that the sensing cable can accurately detect the deformation point position on the sensing cable. PMID:23012560

Parametrically excited oscillation of stay cable and its control in cable-stayed bridges.

PubMed

Sun, Bing-nan; Wang, Zhi-gang; Ko, J M; Ni, Y Q

2003-01-01

This paper presents a nonlinear dynamic model for simulation and analysis of a kind of parametrically excited vibration of stay cable caused by support motion in cable-stayed bridges. The sag, inclination angle of the stay cable are considered in the model, based on which, the oscillation mechanism and dynamic response characteristics of this kind of vibration are analyzed through numerical calculation. It is noted that parametrically excited oscillation of a stay cable with certain sag, inclination angle and initial static tension force may occur in cable-stayed bridges due to deck vibration under the condition that the natural frequency of a cable approaches to about half of the first model frequency of the bridge deck system. A new vibration control system installed on the cable anchorage is proposed as a possible damping system to suppress the cable parametric oscillation. The numerical calculation results showed that with the use of this damping system, the cable oscillation due to the vibration of the deck and/or towers will be considerably reduced.

Identification of internal properties of fibers and micro-swimmers

NASA Astrophysics Data System (ADS)

Plouraboue, Franck; Thiam, Ibrahima; Delmotte, Blaise; Climent, Eric; PSC Collaboration

2016-11-01

In this presentation we discuss the identifiability of constitutive parameters of passive or active micro-swimmers. We first present a general framework for describing fibers or micro-swimmers using a bead-model description. Using a kinematic constraint formulation to describe fibers, flagellum or cilia, we find explicit linear relationship between elastic constitutive parameters and generalised velocities from computing contact forces. This linear formulation then permits to address explicitly identifiability conditions and solve for parameter identification. We show that both active forcing and passive parameters are both identifiable independently but not simultaneously. We also provide unbiased estimators for elastic parameters as well as active ones in the presence of Langevin-like forcing with Gaussian noise using normal linear regression models and maximum likelihood method. These theoretical results are illustrated in various configurations of relaxed or actuated passives fibers, and active filament of known passive properties, showing the efficiency of the proposed approach for direct parameter identification. The convergence of the proposed estimators is successfully tested numerically.

Coaxial cable stripping device facilitates RF cabling fabrication

NASA Technical Reports Server (NTRS)

Hughes, R. S.; Tobias, R. A.

1967-01-01

Coaxial cable stripping device assures clean, right angled shoulder for RF cable connector fabrication. This method requires minimal skill and creates a low voltage standing wave ratio and mechanical stability in the interconnecting RF Cables.

Local vibration enhanced the efficacy of passive exercise on mitigating bone loss in hindlimb unloading rats

NASA Astrophysics Data System (ADS)

Huang, Yunfei; Luan, Huiqin; Sun, Lianwen; Bi, Jingfang; Wang, Ying; Fan, Yubo

2017-08-01

Spaceflight induced bone loss is seriously affecting astronauts. Mechanical stimulation from exercise has been shown to restrain bone resorption as well as improve bone formation. Current exercise countermeasures in space cannot prevent it completely. Active exercise may convert to passive exercise in some ways because of the loss of gravity stimulus and inertia of exercise equipment. The aim of this study was to compare the efficacy of passive exercise or/and local vibration on counteracting the deterioration of the musculoskeletal system, including bone, muscle and tendons in tail-suspended rats. We hypothesized that local vibration could enhance the efficacy of passive exercise on countering bone loss. 40 Sprague Dawley rats were randomly distributed into five groups (n = 8, each): tail-suspension (TS), TS+35 Hz vibration (TSV), TS + passive exercise (TSP), TS + passive exercise coupled with 35 Hz vibration (TSPV) and control (CON). Passive exercise or/and local vibration was performed for 21 days. On day 0 and 21, bone mineral density (BMD) was observed by dual energy X-ray absorptiometry (DXA), and trabecular microstructure was evaluated by microcomputer tomography (μCT) analysis in vivo. Mechanical properties of tibia and tendon were determined by a mechanical testing system. Soleus and bone ash weight was tested by an electronic balance. Results showed that the passive exercise could not prevent the decrease of trabecular BMD, microstructure and bone ash weight induced by TS, whereas vibration and passive exercise coupled with local vibration (PV) could. Biomechanical properties of the tibia and tendon in TSPV group significantly increased compared with TS group. In summary, PV in this study was the best method in preventing weightlessness-induced bone loss. Consistent with our hypothesis, local vibration partly enhanced the effect of passive exercise. Furthermore, this study will be useful in improving countermeasure for astronauts, but also for the rehabilitation of disused or aged osteoporosis.

Development of a 10 m quasi-isotropic strand assembled from 2G wires

NASA Astrophysics Data System (ADS)

Kan, Changtao; Wang, Yinshun; Hou, Yanbing; Li, Yan; Zhang, Han; Fu, Yu; Jiang, Zhe

2018-03-01

Quasi-isotropic strands made of second generation (2G) high temperature superconducting (HTS) wires are attractive to applications of high-field magnets at low temperatures and power transmission cables at liquid nitrogen temperature in virtue of their high current carrying capability and well mechanical property. In this contribution, a 10 m length quasi-isotropic strand is manufactured and successfully tested in liquid nitrogen to verify the feasibility of an industrial scale production of the strand by the existing cabling technologies. The strand with copper sheath consists of 72 symmetrically assembled 2G wires. The uniformity of critical properties of long quasi-isotropic strands, including critical current and n-value, is very important for their using. Critical currents as well as n-values of the strand are measured every 1 m respectively and compared with the simulation results. Critical current and n-value of the strand are calculated basing on the self-consistent model solved by the finite element method (FEM). Effects of self-field on the critical current and n-value distributions in wires of the strand are analyzed in detail. The simulation results show good agreement with the experimental data and the 10 m quasi-isotropic strand has good critical properties uniformity.

Electron Beam Irradiated Intercalated CNT Yarns For Aerospace Applications

NASA Technical Reports Server (NTRS)

Waters, Deborah L.; Gaier, James R.; Williams, Tiffany S.; Lopez Calero, Johnny E.; Ramirez, Christopher; Meador, Michael A.

2015-01-01

Multi-walled CNT yarns have been experimentally and commercially created to yield lightweight, high conductivity fibers with good tensile properties for application as electrical wiring and multifunctional tendons. Multifunctional tendons are needed as the cable structures in tensegrity robots for use in planetary exploration. These lightweight robust tendons can provide mechanical strength for movement of the robot in addition to power distribution and data transmission. In aerospace vehicles, such as Orion, electrical wiring and harnessing mass can approach half of the avionics mass. Use of CNT yarns as electrical power and data cables could reduce mass of the wiring by thirty to seventy percent. These fibers have been intercalated with mixed halogens to increase their specific electrical conductivity to that near copper. This conductivity, combined with the superior strength and fatigue resistance makes it an attractive alternative to copper for wiring and multifunctional tendon applications. Electron beam irradiation has been shown to increase mechanical strength in pristine CNT fibers through increased cross-linking. Both pristine and intercalated CNT yarns have been irradiated using a 5-megavolt electron beam for various durations and the conductivities and tensile properties will be discussed. Structural information obtained using a field emission scanning electron microscope, energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy will correlate microstructural details with bulk properties.

47 CFR 36.341 - Cable and wire facilities expenses-Account 6410 (Class B telephone companies); Accounts 6411...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Cable and wire facilities expenses-Account 6410... Operating Expenses and Taxes Cable and Wire Facilities Expenses § 36.341 Cable and wire facilities expenses... network cable, aerial wire, and conduit systems. (b) The general method of separating cable and wire...

47 CFR 36.341 - Cable and wire facilities expenses-Account 6410 (Class B telephone companies); Accounts 6411...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Cable and wire facilities expenses-Account 6410... Operating Expenses and Taxes Cable and Wire Facilities Expenses § 36.341 Cable and wire facilities expenses... network cable, aerial wire, and conduit systems. (b) The general method of separating cable and wire...

47 CFR 76.930 - Initiation of review of basic cable service and equipment rates.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Initiation of review of basic cable service and...) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Rate Regulation § 76.930 Initiation of review of basic cable service and equipment rates. A cable operator shall file its schedule of...

Space Flight Cable Model Development

NASA Technical Reports Server (NTRS)

Spak, Kaitlin

2013-01-01

This work concentrates the modeling efforts presented in last year's VSGC conference paper, "Model Development for Cable-Harnessed Beams." The focus is narrowed to modeling of space-flight cables only, as a reliable damped cable model is not yet readily available and is necessary to continue modeling cable-harnessed space structures. New experimental data is presented, eliminating the low-frequency noise that plagued the first year's efforts. The distributed transfer function method is applied to a single section of space flight cable for Euler-Bernoulli and shear beams. The work presented here will be developed into a damped cable model that can be incorporated into an interconnected beam-cable system. The overall goal of this work is to accurately predict natural frequencies and modal damping ratios for cabled space structures.

Design and characterization of a biologically inspired quasi-passive prosthetic ankle-foot.

PubMed

Mooney, Luke M; Lai, Cara H; Rouse, Elliott J

2014-01-01

By design, commonly worn energy storage and release (ESR) prosthetic feet cannot provide biologically realistic ankle joint torque and angle profiles during walking. Additionally, their anthropomorphic, cantilever architecture causes their mechanical stiffness to decrease throughout the stance phase of walking, opposing the known trend of the biological ankle. In this study, the design of a quasi-passive pneumatic ankle-foot prosthesis is detailed that is able to replicate the biological ankle's torque and angle profiles during walking. The prosthetic ankle is comprised of a pneumatic piston, bending spring and solenoid valve. The mechanical properties of the pneumatic ankle prosthesis are characterized using a materials testing machine and the properties are compared to those from a common, passive ESR prosthetic foot. The characterization spanned a range of ankle equilibrium pressures and testing locations beneath the foot, analogous to the location of center of pressure within the stance phase of walking. The pneumatic ankle prosthesis was shown to provide biologically appropriate trends and magnitudes of torque, angle and stiffness behavior, when compared to the passive ESR prosthetic foot. Future work will focus on the development of a control system for the quasi-passive device and clinical testing of the pneumatic ankle to demonstrate efficacy.

Noise from implantable Cooper cable.

PubMed

Carrington, V; Zhou, L; Donaldson, N

2005-09-01

Cooper cable is made for implanted devices, usually for connection to stimulating electrodes. An experiment has been performed to see whether these cables would be satisfactory for recording electroneurogram (ENG) signals from cuffs. Four cables were subjected to continuous flexion at 2 Hz while submerged in saline. The cables were connected to a low-noise amplifier, and the noise was measured using a spectrum analyser. These cables had not fractured after 184 million flexions, and the noise in the neural band (500-5000 Hz) had not increased owing to age. Noise in the ENG band increased by less than 3 dB owing to the motion. A fifth, worn cable did fail during the experiment, the conductors becoming exposed to the saline, but this was only apparent by extra noise when the cable was in motion. After 184 million flexions, the four cables were given a more severe test: instead of being connected to the amplifier reference node, two of the four cores of each cable were connected to 18V batteries. Two of the cables were then noisier, but only when in motion, presumably because of leakage between cores. Cooper cables are excellent for transmitting neural signals alone; transmission in one cable of neural signals and power supplies should be avoided if possible.

Optimal Design of Cable-Driven Manipulators Using Particle Swarm Optimization.

PubMed

Bryson, Joshua T; Jin, Xin; Agrawal, Sunil K

2016-08-01

The design of cable-driven manipulators is complicated by the unidirectional nature of the cables, which results in extra actuators and limited workspaces. Furthermore, the particular arrangement of the cables and the geometry of the robot pose have a significant effect on the cable tension required to effect a desired joint torque. For a sufficiently complex robot, the identification of a satisfactory cable architecture can be difficult and can result in multiply redundant actuators and performance limitations based on workspace size and cable tensions. This work leverages previous research into the workspace analysis of cable systems combined with stochastic optimization to develop a generalized methodology for designing optimized cable routings for a given robot and desired task. A cable-driven robot leg performing a walking-gait motion is used as a motivating example to illustrate the methodology application. The components of the methodology are described, and the process is applied to the example problem. An optimal cable routing is identified, which provides the necessary controllable workspace to perform the desired task and enables the robot to perform that task with minimal cable tensions. A robot leg is constructed according to this routing and used to validate the theoretical model and to demonstrate the effectiveness of the resulting cable architecture.

Cable Overheating Risk Warning Method Based on Impedance Parameter Estimation in Distribution Network

NASA Astrophysics Data System (ADS)

Yu, Zhang; Xiaohui, Song; Jianfang, Li; Fei, Gao

2017-05-01

Cable overheating will lead to the cable insulation level reducing, speed up the cable insulation aging, even easy to cause short circuit faults. Cable overheating risk identification and warning is nessesary for distribution network operators. Cable overheating risk warning method based on impedance parameter estimation is proposed in the paper to improve the safty and reliability operation of distribution network. Firstly, cable impedance estimation model is established by using least square method based on the data from distribiton SCADA system to improve the impedance parameter estimation accuracy. Secondly, calculate the threshold value of cable impedance based on the historical data and the forecast value of cable impedance based on the forecasting data in future from distribiton SCADA system. Thirdly, establish risks warning rules library of cable overheating, calculate the cable impedance forecast value and analysis the change rate of impedance, and then warn the overheating risk of cable line based on the overheating risk warning rules library according to the variation relationship between impedance and line temperature rise. Overheating risk warning method is simulated in the paper. The simulation results shows that the method can identify the imedance and forecast the temperature rise of cable line in distribution network accurately. The result of overheating risk warning can provide decision basis for operation maintenance and repair.

Detection of Local Temperature Change on HTS Cables via Time-Frequency Domain Reflectometry

NASA Astrophysics Data System (ADS)

Bang, Su Sik; Lee, Geon Seok; Kwon, Gu-Young; Lee, Yeong Ho; Ji, Gyeong Hwan; Sohn, Songho; Park, Kijun; Shin, Yong-June

2017-07-01

High temperature superconducting (HTS) cables are drawing attention as transmission and distribution cables in future grid, and related researches on HTS cables have been conducted actively. As HTS cables have come to the demonstration stage, failures of cooling systems inducing quench phenomenon of the HTS cables have become significant. Several diagnosis of the HTS cables have been developed but there are still some limitations of the experimental setup. In this paper, a non-destructive diagnostic technique for the detection of the local temperature change point is proposed. Also, a simulation model of HTS cables with a local temperature change point is suggested to verify the proposed diagnosis. The performance of the diagnosis is checked by comparative analysis between the proposed simulation results and experiment results of a real-world HTS cable. It is expected that the suggested simulation model and diagnosis will contribute to the commercialization of HTS cables in the power grid.

Experimentally determined transport and magnetization ac losses of small cable models constructed from YBCO coated conductors

NASA Astrophysics Data System (ADS)

Šouc, J.; Vojenčiak, M.; Gömöry, F.

2010-04-01

Several short cable models were constructed from YBCO coated conductor (YBCO CC) to study their basic dc and ac electrical properties. They were prepared using superconducting tapes helically wound on fiberglass former of different diameter (5, 8 and 10 mm) with different twist pitch (from 1.7 up to 2.4 cm). The number of parallel-connected tapes ranged from 1 up to 6. The standard length of the models was 11 cm. In one case a 35 cm long model has been manufactured in order to perform a bending test. We observed that the critical currents of the models were proportional to the number of tapes used for their construction. Transport and magnetization ac loss were measured at 36 and 72 Hz.

Test plan and report for Space Shuttle launch environment testing of Bergen cable technology safety cable

NASA Technical Reports Server (NTRS)

Ralph, John

1992-01-01

Bergen Cable Technology (BCT) has introduced a new product they refer to as 'safety cable'. This product is intended as a replacement for lockwire when installed per Aerospace Standard (AS) 4536 (included in Appendix D of this document). Installation of safety cable is reportedly faster and more uniform than lockwire. NASA/GSFC proposes to use this safety cable in Shuttle Small Payloads Project (SSPP) applications on upcoming Shuttle missions. To assure that BCT safety cable will provide positive locking of fasteners equivalent to lockwire, the SSPP will conduct vibration and pull tests of the safety cable.

Wire in the Cable-Driven System of Surgical Robot

NASA Astrophysics Data System (ADS)

Wang, X. F.; Lv, N.; Mu, H. Z.; Xue, L. J.

2017-07-01

During the evolution of the surgical robot, cable plays an important role. It translates motion and force precisely from surgeon’s hand to the tool’s tips. In the paper, the vertical wires, the composition of cable, are mathematically modeled from a geometric point of view. The cable structure and tension are analyzed according to the characteristics of wire screw twist. The structural equations of the wires in different positions are derived for both non-bent cable and bent cable, respectively. The bending moment formula of bent cable is also obtained. This will help researchers find suitable cable and design more matched pulley.

Development of external cooling cryo-resistive cable systems. Part 2: Insulation characteristics on 66 kV rated cryo-resistive testing cable

NASA Astrophysics Data System (ADS)

Ishihara, Kaoru; Akita, Shige; Suzuki, Hiroshi; Ogata, Junichi; Nemoto, Minoru

1987-08-01

Cryo-resistive cable system was tested to demonstrate dielectric characteristics. Dielectric characteristics of 66kV cryo-resistive cable at the start of immersion cooling in the liquid nitrogen were 2.25 specific dielectric constant and 0.18 percent dielectric loss which was less than 0.4 percent , the aimed value. Electrostatic capacity and dielectric loss tangent of dielectric characteristics under the applied voltage did not depend on the voltage and the dielectric loss was less than 0.4 percent through the temperature range from -170 to -190C. These values fulfilled the specifications on 275kV class cryo-resistive cable design. The tested cable passed the cable test on 66kV oil-filled cable (ac 90kV, 10 min), but broken down at ac 110kV on the way to endurance testing voltage 130kV. The breakdown occurred due to the mechanical damage of cable insulator by bending and thermal contraction of the cable. It is necessary from these facts to develop flexible cable terminal and joint which can absorb the contraction to realize 275kV cryo-resistive cable. (19 figs, 7 tabs, 15 refs).

Number of lightning discharges causing damage to lightning arrester cables for aerial transmission lines in power systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nikiforov, E. P.

2009-07-15

Damage by lightning discharges to lightning arrester cables for 110-175 kV aerial transmission lines is analyzed using data from power systems on incidents with aerial transmission lines over a ten year operating period (1997-2006). It is found that failures of lightning arrester cables occur when a tensile force acts on a cable heated to the melting point by a lightning current. The lightning currents required to heat a cable to this extent are greater for larger cable cross sections. The probability that a lightning discharge will develop decreases as the amplitude of the lightning current increases, which greatly reduces themore » number of lightning discharges which damage TK-70 cables compared to TK-50 cables. In order to increase the reliability of lightning arrester cables for 110 kV aerial transmission lines, TK-70 cables should be used in place of TK-50 cables. The number of lightning discharges per year which damage lightning arrester cables is lowered when the density of aerial transmission lines is reduced within the territory of electrical power systems. An approximate relationship between these two parameters is obtained.« less

Improved interfacial and electrical properties of GaAs metal-oxide-semiconductor capacitors with HfTiON as gate dielectric and TaON as passivation interlayer

NASA Astrophysics Data System (ADS)

Wang, L. S.; Xu, J. P.; Zhu, S. Y.; Huang, Y.; Lai, P. T.

2013-08-01

The interfacial and electrical properties of sputtered HfTiON on sulfur-passivated GaAs with or without TaON as interfacial passivation layer (IPL) are investigated. Experimental results show that the GaAs metal-oxide-semiconductor capacitor with HfTiON/TaON stacked gate dielectric annealed at 600 °C exhibits low interface-state density (1.0 × 1012 cm-2 eV-1), small gate leakage current (7.3 × 10-5 A cm-2 at Vg = Vfb + 1 V), small capacitance equivalent thickness (1.65 nm), and large equivalent dielectric constant (26.2). The involved mechanisms lie in the fact that the TaON IPL can effectively block the diffusions of Hf, Ti, and O towards GaAs surface and suppress the formation of interfacial As-As bonds, Ga-/As-oxides, thus unpinning the Femi level at the TaON/GaAs interface and improving the interface quality and electrical properties of the device.

Application and research of recyclable cables in foundation pit support engineering

NASA Astrophysics Data System (ADS)

Zheng, Suping

2018-05-01

Anchoring cables are widely used in the construction of foundation pit as a temporary support structure. After the construction is completed, the anchor cables left in the ground will not only cause environmental pollution but also cause a great waste of resources. The emergence of recyclable cable technology, to avoid such problems, to achieve the secondary use of the anchor cable, excavation in the excavation project is more and more widely used. Combined with the design and construction of recoverable anchor cable in engineering practice, the application effect of recoverable anchor cable in foundation pit support is analyzed, and the conclusion that the support effect of recoverable anchor cable is stable and safe can be obtained Recyclable anchor cable in the future support projects to provide a reference.

A family of asymptotically stable control laws for flexible robots based on a passivity approach

NASA Technical Reports Server (NTRS)

Lanari, Leonardo; Wen, John T.

1991-01-01

A general family of asymptotically stabilizing control laws is introduced for a class of nonlinear Hamiltonian systems. The inherent passivity property of this class of systems and the Passivity Theorem are used to show the closed-loop input/output stability which is then related to the internal state space stability through the stabilizability and detectability condition. Applications of these results include fully actuated robots, flexible joint robots, and robots with link flexibility.

47 CFR 76.1001 - Unfair practices generally.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Competitive Access to Cable Programming § 76.1001 Unfair practices generally. (a) Unfair practices generally. No cable operator, satellite cable programming vendor in which a cable operator has an attributable interest, or satellite broadcast programming vendor...

47 CFR 76.1001 - Unfair practices generally.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Competitive Access to Cable Programming § 76.1001 Unfair practices generally. (a) Unfair practices generally. No cable operator, satellite cable programming vendor in which a cable operator has an attributable interest, or satellite broadcast programming vendor...

Method to improve superconductor cable

DOEpatents

Borden, A.R.

1984-03-08

A method is disclosed of making a stranded superconductor cable having improved flexing and bending characteristics. In such method, a plurality of superconductor strands are helically wound around a cylindrical portion of a mandrel which tapers along a transitional portion to a flat end portion. The helically wound strands form a multistrand hollow cable which is partially flattened by pressure rollers as the cable travels along the transitional portion. The partially flattened cable is impacted with repeated hammer blows as the hollow cable travels along the flat end portion. The hammer blows flatten both the internal and the external surfaces of the strands. The cable is fully flattened and compacted by two sets of pressure rollers which engage the flat sides and the edges of the cable after it has traveled away from the flat end portion of the mandrel. The flattened internal surfaces slide easily over one another when the cable is flexed or bent so that there is very little possibility that the cable will be damaged by the necessary flexing and bending required to wind the cable into magnet coils.

External heating of electrical cables and auto-ignition investigation.

PubMed

Courty, L; Garo, J P

2017-01-05

Electric cables are now extensively used for both residential and industrial applications. During more than twenty years, multi-scale approaches have been developed to study fire behavior of such cables that represents a serious challenge. Cables are rather complicated materials because they consist of an insulated part and jacket of polymeric materials. These polymeric materials can have various chemical structures, thicknesses and additives and generally have a char-forming tendency when exposed to heat source. In this work, two test methods are used for the characterization of cable pyrolysis and flammability. The first one permits the investigation of cable pyrolysis. A description of the cable mass loss is obtained, coupling an Arrhenius expression with a 1D thermal model of cables heating. Numerical results are successfully compared with experimental data obtained for two types of cable commonly used in French nuclear power plants. The second one is devoted to ignition investigations (spontaneous or piloted) of these cables. All these basic observations, measurements and modelling efforts are of major interest for a more comprehensive fire resistance evaluation of electric cables. Copyright © 2016 Elsevier B.V. All rights reserved.

Electronic properties of graphene nano-flakes: energy gap, permanent dipole, termination effect, and Raman spectroscopy.

PubMed

Singh, Sandeep Kumar; Neek-Amal, M; Peeters, F M

2014-02-21

The electronic properties of graphene nano-flakes (GNFs) with different edge passivation are investigated by using density functional theory. Passivation with F and H atoms is considered: C(N(c)) X(N(x)) (X = F or H). We studied GNFs with 10 < Nc < 56 and limit ourselves to the lowest energy configurations. We found that: (i) the energy difference Δ between the highest occupied molecular orbital and the lowest unoccupied molecular orbital decreases with Nc, (ii) topological defects (pentagon and heptagon) break the symmetry of the GNFs and enhance the electric polarization, (iii) the mutual interaction of bilayer GNFs can be understood by dipole-dipole interaction which were found sensitive to the relative orientation of the GNFs, (iv) the permanent dipoles depend on the edge terminated atom, while the energy gap is independent of it, and (v) the presence of heptagon and pentagon defects in the GNFs results in the largest difference between the energy of the spin-up and spin-down electrons which is larger for the H-passivated GNFs as compared to F-passivated GNFs. Our study shows clearly the effect of geometry, size, termination, and bilayer on the electronic properties of small GNFs. This study reveals important features of graphene nano-flakes which can be detected using Raman spectroscopy.

A cable-driven wrist robotic rehabilitator using a novel torque-field controller for human motion training.

PubMed

Chen, Weihai; Cui, Xiang; Zhang, Jianbin; Wang, Jianhua

2015-06-01

Rehabilitation technologies have great potentials in assisted motion training for stroke patients. Considering that wrist motion plays an important role in arm dexterous manipulation of activities of daily living, this paper focuses on developing a cable-driven wrist robotic rehabilitator (CDWRR) for motion training or assistance to subjects with motor disabilities. The CDWRR utilizes the wrist skeletal joints and arm segments as the supporting structure and takes advantage of cable-driven parallel design to build the system, which brings the properties of flexibility, low-cost, and low-weight. The controller of the CDWRR is designed typically based on a virtual torque-field, which is to plan "assist-as-needed" torques for the spherical motion of wrist responding to the orientation deviation in wrist motion training. The torque-field controller can be customized to different levels of rehabilitation training requirements by tuning the field parameters. Additionally, a rapidly convergent parameter self-identification algorithm is developed to obtain the uncertain parameters automatically for the floating wearable structure of the CDWRR. Finally, experiments on a healthy subject are carried out to demonstrate the performance of the controller and the feasibility of the CDWRR on wrist motion training or assistance.

Non-destructive evaluation of polyolefin thermal aging using infrared spectroscopy

NASA Astrophysics Data System (ADS)

Fifield, Leonard S.; Shin, Yongsoon; Simmons, Kevin L.

2017-04-01

Fourier transform infrared (FTIR) spectroscopy is an information-rich method that reveals chemical bonding near the surface of polymer composites. FTIR can be used to verify composite composition, identify chemical contaminants and expose composite moisture content. Polymer matrix changes due to thermal exposure including loss of additives, chain scission, oxidation and changes in crystallinity may also be determined using FTIR spectra. Portable handheld instruments using non-contact reflectance or surface contact attenuated total reflectance (ATR) may be used for nondestructive evaluation (NDE) of thermal aging in polymer and composite materials of in-service components. We report the use of ATR FTIR to track oxidative thermal aging in ethylene-propylene rubber (EPR) and chlorinated polyethylene (CPE) materials used in medium voltage nuclear power plant electrical cable insulation and jacketing. Mechanical property changes of the EPR and CPE materials with thermal degradation for correlation with FTIR data are tracked using indenter modulus (IM) testing. IM is often used as a local NDE metric of cable jacket health. The FTIR-determined carbonyl index was found to increase with IM and may be a valuable NDE metric with advantages over IM for assessing cable remaining useful life.

Non-Destructive Evaluation of Polyolefin Thermal Aging Using Infrared Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fifield, Leonard S.; Shin, Yongsoon; Simmons, Kevin L.

Fourier transform infrared (FTIR) spectroscopy is an information-rich method that reveals chemical bonding near the surface of polymer composites. FTIR can be used to verify composite composition, identify chemical contaminants and expose composite moisture content. Polymer matrix changes due to thermal exposure including loss of additives, chain scission, oxidation and changes in crystallinity may also be determined using FTIR spectra. Portable handheld instruments using non-contact reflectance or surface contact attenuated total reflectance (ATR) may be used for non-destructive evaluation (NDE) of thermal aging in polymer and composite materials of in-service components. We report the use of ATR FTIR to trackmore » oxidative thermal aging in ethylene-propylene rubber (EPR) and chlorinated polyethylene (CPE) materials used in medium voltage nuclear power plant electrical cable insulation and jacketing. Mechanical property changes of the EPR and CPE materials with thermal degradation for correlation with FTIR data are tracked using indenter modulus (IM) testing. IM is often used as a local NDE metric of cable jacket health. The FTIR-determined carbonyl index was found to increase with IM and may be a valuable NDE metric with advantages over IM for assessing cable remaining useful life.« less

A cable-driven wrist robotic rehabilitator using a novel torque-field controller for human motion training

NASA Astrophysics Data System (ADS)

Chen, Weihai; Cui, Xiang; Zhang, Jianbin; Wang, Jianhua

2015-06-01

Rehabilitation technologies have great potentials in assisted motion training for stroke patients. Considering that wrist motion plays an important role in arm dexterous manipulation of activities of daily living, this paper focuses on developing a cable-driven wrist robotic rehabilitator (CDWRR) for motion training or assistance to subjects with motor disabilities. The CDWRR utilizes the wrist skeletal joints and arm segments as the supporting structure and takes advantage of cable-driven parallel design to build the system, which brings the properties of flexibility, low-cost, and low-weight. The controller of the CDWRR is designed typically based on a virtual torque-field, which is to plan "assist-as-needed" torques for the spherical motion of wrist responding to the orientation deviation in wrist motion training. The torque-field controller can be customized to different levels of rehabilitation training requirements by tuning the field parameters. Additionally, a rapidly convergent parameter self-identification algorithm is developed to obtain the uncertain parameters automatically for the floating wearable structure of the CDWRR. Finally, experiments on a healthy subject are carried out to demonstrate the performance of the controller and the feasibility of the CDWRR on wrist motion training or assistance.

Superconducting ac cable

NASA Astrophysics Data System (ADS)

Schmidt, F.

1980-11-01

The components of a superconducting 110 kV ac cable for power ratings or = 2000 MVA were developed. The cable design is of the semiflexible type, with a rigid cryogenic envelope containing a flexible hollow coaxial cable core. The cable core consists of spirally wound Nb-A1 composite wires electrically insulated by high pressure polyethylene tape wrappings. A 35 m long single phase test cable with full load terminals rated at 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of this cable design.

Flat conductor cable design, manufacture, and installation

NASA Technical Reports Server (NTRS)

Angele, W.; Hankins, J. D.

1973-01-01

Pertinent information for hardware selection, design, manufacture, and quality control necessary for flat conductor cable interconnecting harness application is presented. Comparisons are made between round wire cable and flat conductor cable. The flat conductor cable interconnecting harness systems show major cost, weight, and space savings, plus increased system performance and reliability. The design application section includes electrical characteristics, harness design and development, and a full treatise on EMC considerations. Manufacturing and quality control sections pertain primarily to the developed conductor-contact connector system and special flat conductor cable to round wire cable transitions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bahder, G.; Bopp, L.A.; Eager, G.S.

This report covers the continuation of the work to develop technology to manufacture chemically crosslinked polyethylene insulated power cables in the ac voltage range of 138 kV to 345 kV having insulation thicknesses approximately equal to that of oil impregnated paper insulated cables. It also incorporates the development of field molded splices and terminations for new high voltage stress 138 kV cables. After reviewing the main equipment elements, incorporated in the pilot extrusion line, the special features of this system are noted and a step-by-step description of the cable extrusion process is given. Optimization of the process and introduction ofmore » modifications in the equipment culminated with the production of 138 kV cables. Results of laboratory tests to demonstrate the high quality of the cables are given. The development of molded splices and molded stress control cones was initiated with the work on model cables and followed by the making of splices and terminations on 138 kV cables. The molded components are made with the same purified insulating compound as used in the manufacture of the cables. Both the molded splices and the molded stress control cones have been fully tested in the laboratory. Following the completion of the development of the 138 kV cable a high stress 230 kV crosslinked polyethylene cable was developed and optimized. A full evaluation program similar to the one utilized on the 138 kV cable was carried out. Subsequently, work to develop a 345 kV high voltage stress cable, having insulation thickness of 1.02'' was undertaken. 345 kV cables were successfully manufactured and tested. However, additional work is required to further optimize the quality of this cable.« less

Defining the extent of cables loss in endometrial cancer subtypes and its effectiveness as an inhibitor of cell proliferation in malignant endometrial cells in vitro and in vivo.

PubMed

DeBernardo, Robert L; Littell, Ramey D; Luo, Hongwei; Duska, Linda R; Oliva, Esther; Kirley, Sandra D; Lynch, Maureen P; Zukerberg, Lawrence R; Rueda, Bo R

2005-01-01

Loss of Cables expression is associated with a high incidence of endometrial hyperplasia and endometrial adenocarcinoma in humans. The Cables mutant mouse develops endometrial hyperplasia and following exposure to chronic estrogen develops early endometrial adenocarcinoma. The objectives of the current study were to determine if: (1) loss of Cables expression occurred in high grade endometrioid adenocarcinoma, uterine serous and clear cell carcinoma as observed in endometrial hyperplasia and low grade endometrial adenocarcinoma; (2) overexpression of Cables inhibited cell proliferation in endometrial cancer (EC) cells in vitro and in vivo; and (3) progesterone could regulate the expression of Cables mRNA. Hyperplastic endometrium and low and high grade endometrioid adenocarcinoma showed loss of Cables expression when compared to benign control secretory endometrium. Loss of Cables expression in serous and clear cell tumors was similar to that observed in endometrioid adenocarcinomas with greater than 80% showing loss of protein expression. Treatment of EC lines with progesterone increased cables expression in low-grade EC whereas it had no effect on cables expression in cells derived from high-grade EC. The progesterone-induced increase in cables was abrogated in the presence of a progesterone receptor (PR) antagonist, suggesting the PR mediates the increase. Cables overexpression inhibited cell proliferation of well differentiated EC cells and had no effect on the poorly differentiated EC cells. The capacity to form tumors was dramatically reduced in the Cables overexpressing cell lines compared to those cells containing the control vector. Collectively these results suggest that Cables is an important regulator of cell proliferation and loss of Cables expression contributes to the development of all types of EC.

Temperature Distribution and Critical Current of Long HTS Cables Cooled with Subcooled Liquid Nitrogen

NASA Astrophysics Data System (ADS)

Vyatkin, V. S.; Ivanov, Y. V.; Watanabe, H.; Chikumoto, N.; Yamaguchi, S.

2017-07-01

Cooling of the long HTS power transmission lines performs by pumping of subcooled liquid nitrogen (LN2) along the cable. The temperature of LN2 along the cable increases due to the heat losses of the cryostat and heat generation in the HTS cable. The experiment using test cable line in Ishikari shows that flow rate of 35 L/min retains increasing of LN2 temperature by 1 K per 1 km of length. The technology when the back flow of LN2 cools the radiation shield surrounding the cable pipe is also applied in Ishikari-2 project. In this case the ambient heat flow into cable pipe is 50 times less than that without radiation shield. Back flow of LN2 removes almost all heat coming from the environment. When transport current is close to the critical value the Joule heat of HTS cable is significant. This heat additionally increases the temperature of LN2 flowing along the HTS cable. Near the outlet the temperature of HTS cable is maximal and the local critical current is minimal. The current matching critical current criterion of average electrical field of E 0 = 10-4 V/m provides the voltage drop and significant Joule heat at the hot end of the cable. It can lead the damage of the cable. The present work contains analysis of temperature distribution along the cable and the way to achieve the fail-safe operation of long HTS cable cooled by subcooled LN2. We also performed extrapolation of obtained results for several times longer cable lines by decreasing the LN2 flow rate.

Workers in the VAB test SRB cables on STS-98 solid rocket boosters

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- United Space Alliance SRB technician Richard Bruns attaches a cable end cover to a cable pulled from the solid rocket booster on Space Shuttle Atlantis. The Shuttle was rolled back from Launch Pad 39A in order to conduct tests on the SRB cables. A prior extensive evaluation of NASA'''s SRB cable inventory on the shelf revealed conductor damage in four (of about 200) cables. Shuttle managers decided to prove the integrity of the system tunnel cables already on Atlantis before launching. Workers are conducting inspections, making continuity checks and conducting X-ray analysis on the cables. The launch has been rescheduled no earlier than Feb. 6.

Comparison of alternative designs for reducing complex neurons to equivalent cables.

PubMed

Burke, R E

2000-01-01

Reduction of the morphological complexity of actual neurons into accurate, computationally efficient surrogate models is an important problem in computational neuroscience. The present work explores the use of two morphoelectrotonic transformations, somatofugal voltage attenuation (AT cables) and signal propagation delay (DL cables), as bases for construction of electrotonically equivalent cable models of neurons. In theory, the AT and DL cables should provide more accurate lumping of membrane regions that have the same transmembrane potential than the familiar equivalent cables that are based only on somatofugal electrotonic distance (LM cables). In practice, AT and DL cables indeed provided more accurate simulations of the somatic transient responses produced by fully branched neuron models than LM cables. This was the case in the presence of a somatic shunt as well as when membrane resistivity was uniform.

Improved models of cable-to-post attachments for high-tension cable barriers.

DOT National Transportation Integrated Search

2012-05-01

Computer simulation models were developed to analyze and evaluate a new cable-to-post attachment for high-tension cable : barriers. The models replicated the performance of a keyway bolt currently used in the design of a high-tension cable : median b...

Local Area Networks.

ERIC Educational Resources Information Center

Marks, Kenneth E.; Nielsen, Steven

1991-01-01

Discusses cabling that is needed in local area networks (LANs). Types of cables that may be selected are described, including twisted pair, coaxial cables (or ethernet), and fiber optics; network topologies, the manner in which the cables are laid out, are considered; and cable installation issues are discussed. (LRW)

The biodegradation of cable oil components: impact of oil concentration, nutrient addition and bioaugmentation.

PubMed

Towell, Marcie G; Paton, Graeme I; Semple, Kirk T

2011-12-01

The effect of cable oil concentration, nutrient amendment and bioaugmentation on cable oil component biodegradation in a pristine agricultural soil was investigated. Biodegradation potential was evaluated over 21 d by measuring cumulative CO(2) respiration on a Micro-Oxymax respirometer and (14)C-phenyldodecane mineralisation using a (14)C-respirometric assay. Cable oil concentration had a significant effect upon oil biodegradation. Microbial respiratory activity increased with increasing cable oil concentration, whereas (14)C-phenydodecane mineralisation decreased. Bioaugmentation achieved the best cable oil biodegradation performance, resulting in increases in cumulative CO(2) respiration, and maximum rates and extents of (14)C-phenyldodecane mineralisation. Generally, nutrient amendment also enhanced cable oil biodegradation, but not to the extent that degrader amendment did. Cable oil biodegradation was a function of (i) cable oil concentration and (ii) catabolic ability of microbial populations. Bioaugmentation may enhance cable oil biodegradation, and is dependent upon composition, cell number and application of catabolic inocula to soil. Copyright © 2011 Elsevier Ltd. All rights reserved.

Frequency Domain Reflectometry Modeling and Measurement for Nondestructive Evaluation of Nuclear Power Plant Cables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glass, Samuel W.; Fifield, Leonard S.; Jones, Anthony M.

Cable insulation polymers are among the more susceptible materials to age-related degradation within a nuclear power plant. This is recognized by both regulators and utilities, so all plants have developed cable aging management programs to detect damage before critical component failure in compliance with regulatory guidelines. Although a wide range of tools are available to evaluate cables and cable systems, cable aging management programs vary in how condition monitoring and NDE is conducted as utilities search for the most reliable and cost-effective ways to assess cable system condition. Frequency domain reflectometry (FDR) is emerging as one valuable tool to locatemore » and assess damaged portions of a cable system with minimal cost and only requires access in most cases to one of the cable terminal ends. This work examines a physics-based model of a cable system and relates it to FDR measurements for a better understanding of specific damage influences on defect detectability.« less

30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of electric... a minimum of 24 hours at a temperature of 70 ±10 °F (21.1 ±5.5 °C) and a relative humidity of 55 ±10...

30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of electric... a minimum of 24 hours at a temperature of 70 ±10 °F (21.1 ±5.5 °C) and a relative humidity of 55 ±10...

30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of electric... a minimum of 24 hours at a temperature of 70 ±10 °F (21.1 ±5.5 °C) and a relative humidity of 55 ±10...

65. CALIFORNIA STREET CABLE RAILWAY WINDING MACHINERY: Photocopy of ...

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

65. CALIFORNIA STREET CABLE RAILWAY - WINDING MACHINERY: Photocopy of February 1955 photograph showing the winding machinery of the California Street Cable Railroad. The two suspended sheaves on the right of the photograph bore down on the cable as it left the winders, supplying tension to the cable and eliminating the need for a long tension run. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

Hybrid modeling for dynamic analysis of cable-pulley systems with time-varying length cable and its application

NASA Astrophysics Data System (ADS)

Wang, Jing; Qi, Zhaohui; Wang, Gang

2017-10-01

The dynamic analysis of cable-pulley systems is investigated in this paper, where the time-varying length characteristic of the cable as well as the coupling motion between the cable and the pulleys are considered. The dynamic model for cable-pulley systems are presented based on the principle of virtual power. Firstly, the cubic spline interpolation is adopted for modeling the flexible cable elements and the virtual 1powers of tensile strain, inertia and gravity forces on the cable are formulated. Then, the coupled motions between the cable and the movable or fixed pulley are described by the input and output contact points, based on the no-slip assumption and the spatial description. The virtual powers of inertia, gravity and applied forces on the contact segment of the cable, the movable and fixed pulleys are formulated. In particular, the internal node degrees of freedom of spline cable elements are reduced, which results in that only the independent description parameters of the nodes connected to the pulleys are included in the final governing dynamic equations. At last, two cable-pulley lifting mechanisms are considered as demonstrative application examples where the vibration of the lifting process is investigated. The comparison with ADAMS models is given to prove the validity of the proposed method.

The use of sublaminar cables to replace Luque wires.

PubMed

Songer, M N; Spencer, D L; Meyer, P R; Jayaraman, G

1991-08-01

Sublaminar wires have been used in conjunction with posterior instrumentation to stabilize the spine. Sublaminar wiring has fallen into disfavor because of an increase in neurologic complications with the Luque technique as well as wire breakage, dural tears, and difficulty of removal. A cable system consisting of two 49-stranded stainless steel cables connected to one malleable leader was designed to overcome these shortcomings. Biomechanical testing revealed that the maximum yield strength of a single stainless steel cable loop was 2.85-2.94 times greater than a double 0.05-in. stainless steel wire loop. The fatigue tests demonstrated that the stainless steel cables required 6-22 times more cycles to failure than the stainless steel wire. Many of the titanium cables failed immediately under higher loads (0-100 lb) because of slipping of the crimp. The preliminary clinical results after a mean of 19 months of follow-up of 245 cables are encouraging. There has been no breakage or loosening of the cables and no complications associated with the use of the cables. The stainless steel cables are very strong, but more important, the cable flexibility prevents repeated contusions to the spinal cord during insertion of the rods and tightening of wires. The cable conforms to the undersurface of the lamina. This may lead to a decrease in neurologic complications.

Recent Progress on Stability and Passivation of Black Phosphorus.

PubMed

Abate, Yohannes; Akinwande, Deji; Gamage, Sampath; Wang, Han; Snure, Michael; Poudel, Nirakar; Cronin, Stephen B

2018-05-11

From a fundamental science perspective, black phosphorus (BP) is a canonical example of a material that possesses fascinating surface and electronic properties. It has extraordinary in-plane anisotropic electrical, optical, and vibrational states, as well as a tunable band gap. However, instability of the surface due to chemical degradation in ambient conditions remains a major impediment to its prospective applications. Early studies were limited by the degradation of black phosphorous surfaces in air. Recently, several robust strategies have been developed to mitigate these issues, and these novel developments can potentially allow researchers to exploit the extraordinary properties of this material and devices made out of it. Here, the fundamental chemistry of BP degradation and the tremendous progress made to address this issue are extensively reviewed. Device performances of encapsulated BP are also compared with nonencapsulated BP. In addition, BP possesses sensitive anisotropic photophysical surface properties such as excitons, surface plasmons/phonons, and topologically protected and Dirac semi-metallic surface states. Ambient degradation as well as any passivation method used to protect the surface could affect the intrinsic surface properties of BP. These properties and the extent of their modifications by both the degradation and passivation are reviewed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cable coupling lightning transient qualification

NASA Technical Reports Server (NTRS)

Cook, M.

1989-01-01

Simulated lightning strike testing of instrumentation cabling on the redesigned solid rocket motor was performed. Testing consisted of subjecting the lightning evaluation test article to simulated lightning strikes and evaluating the effects of instrumentation cable transients on cables within the system tunnel. The maximum short-circuit current induced onto a United Space Boosters, Inc., operational flight cable within the systems tunnel was 92 A, and the maximum induced open-circuit voltage was 316 V. These levels were extrapolated to the worst-case (200 kA) condition of NASA specification NSTS 07636 and were also scaled to full-scale redesigned solid rocket motor dimensions. Testing showed that voltage coupling to cables within the systems tunnel can be reduced 40 to 90 dB and that current coupling to cables within the systems tunnel can be reduced 30 to 70 dB with the use of braided metallic sock shields around cables that are external to the systems tunnel. Testing also showed that current and voltage levels induced onto cables within the systems tunnel are partially dependant on the cables' relative locations within the systems tunnel. Results of current injections to the systems tunnel indicate that the dominant coupling mode on cables within the systems tunnel is not from instrumentation cables but from coupling through the systems tunnel cover seam apertures. It is recommended that methods of improving the electrical bonding between individual sections of the systems tunnel covers be evaluated. Further testing to better characterize redesigned solid rocket motor cable coupling effects as an aid in developing methods to reduce coupling levels, particularly with respect to cable placement within the systems tunnel, is also recommended.

Optic fiber sensor-based smart bridge cable with functionality of self-sensing

NASA Astrophysics Data System (ADS)

He, Jianping; Zhou, Zhi; Jinping, Ou

2013-02-01

Bridge cables, characterized by distributed large span, serving in harsh environment and vulnerability to random damage, are the key load-sustaining components of cable-based bridges. To ensure the safety of the bridge structure, it is critical to monitor the loading conditions of these cables under lengthwise random damages. Aiming at obtaining accurate monitoring at the critical points as well as the general information of the cable force distributed along the entire cable, this paper presents a study on cable force monitoring by combining optical fiber Bragg grating (FBG) sensors and Brillouin optical time domain analysis/reflectory (BOTDA/R) sensing technique in one single optical fiber. A smart FRP-OF-FBG rebar based cable was fabricated by protruding a FRP packaged OF-FBG sensor into the bridge cable. And its sensing characteristics, stability under high stress state temperature self-compensation as well as BOTDA/R distributed data improvement by local FBG sensors have been investigated. The results show that FRP-OF-FBG rebar in the smart cable can deform consistantly along with the steel wire and the cable force obtained from the optical fiber sensors agree well with theoretical value with relative error less than ±5%. Besides, the temperature self-compensation method provides a significant cost-effective technique for the FRP-OF-FBG based cables' in situ cable force measurement. And furthermore, potential damages of the bridge cable, e.g. wire breaking and corrosion, can be characterized and symbolized by the discontinuity and fluctuation of the distributed BOTDA data thereafter accuracy improved by local FBG sensors.

The biomechanical analysis of sublaminar wires and cables using luque segmental spinal instrumentation.

PubMed

Parsons, J R; Chokshi, B V; Lee, C K; Gundlapalli, R V; Stamer, D

1997-02-01

Data was gathered from biomechanical testing of 10 thoracic human cadaveric spines. Spines were tested intact and with a Luque rectangle fixed with wire or cable. To compare the rigidity of fixation and intraspinal penetration of sublaminar monofilament wire and multistrand cable under identical conditions using human cadaveric spines. Reports of neurologic and mechanical complications associated with sublaminar wiring techniques have led to the recent development of more flexible multistrand cable systems. The relative performance of flexible cable versus monofilament wire has not been explored fully in a controlled mechanical environment. A servohydraulic mechanical testing machine was used to measure the static mechanical stiffness of sublaminar wire or cable fixation in conjunction with a Luque rectangle for thoracic human cadaveric spine segments in flexion-extension and torsion modes. Cyclic testing was performed in the flexion-extension mode. Intraspinal penetration of wires and cables was measured. Spine fixation with sublaminar wire and cable resulted in constructs of equal stiffness in flexion-extension and torsion modes. Cyclic testing also indicated similar fatigue profiles for wire- and cable-instrumented spines. Wire and cable fixed spines displayed greater stiffness than the intact spines. Cable encroachment of the spinal canal was less than that seen with wire. Sublaminar multistrand cable may be a rational alternative to monofilament wire in segmental spinal instrumentation because it provides less encroachment into the spinal canal. Further, cadaveric spines instrumented with wire and cable display equivalent mechanical behavior, statically and under cyclic loading. The potential advantages of cable, however, must be balanced against a substantial increase in cost relative to wire.

Commercialization of Medium Voltage HTS Triax TM Cable Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knoll, David

2012-12-31

The original project scope that was established in 2007 aimed to install a 1,700 meter (1.1 mile) medium voltage HTS Triax{TM} cable system into the utility grid in New Orleans, LA. In 2010, however, the utility partner withdrew from the project, so the 1,700 meter cable installation was cancelled and the scope of work was reduced. The work then concentrated on the specific barriers to commercialization of HTS cable technology. The modified scope included long-length HTS cable design and testing, high voltage factory test development, optimized cooling system development, and HTS cable life-cycle analysis. In 2012, Southwire again analyzed themore » market for HTS cables and deemed the near term market acceptance to be low. The scope of work was further reduced to the completion of tasks already started and to testing of the existing HTS cable system in Columbus, OH. The work completed under the project included: • Long-length cable modeling and analysis • HTS wire evaluation and testing • Cable testing for AC losses • Optimized cooling system design • Life cycle testing of the HTS cable in Columbus, OH • Project management. The 200 meter long HTS Triax{TM} cable in Columbus, OH was incorporated into the project under the initial scope changes as a test bed for life cycle testing as well as the site for an optimized HTS cable cooling system. The Columbus cable utilizes the HTS TriaxTM design, so it provided an economical tool for these of the project tasks.« less