WorldWideScience

Sample records for twin wire electric

  1. Durability to Electromigration of an Annealing-Twinned Ag-4Pd Alloy Wire Under Current Stressing

    Science.gov (United States)

    Chuang, Tung-Han; Lin, Hsin-Jung; Chuang, Chien-Hsun; Tsai, Chih-Hsin; Lee, Jun-Der; Tsai, Hsing-Hua

    2014-11-01

    Ag-4Pd binary alloy wire has been produced as an alternative to a previously developed Ag-8Au-3Pd ternary alloy wire to meet requirements for high electrical conductivity and low cost. The electrical resistivity of this Ag-4Pd bonding wire, manufactured with a conventional method, is 3.7 μΩ cm, close to the values of traditional 3N Au wire (3.5 μΩ cm) and Pd-coated Cu wire (1.8 μΩ cm). To further improve the performance of this bonding wire, a large amount of annealing twins were introduced in this Ag-4Pd alloy wire through an innovative concept of sequential drawing and multiple annealing processes. The resulting electrical resistivity of this annealing-twinned Ag-4Pd wire is 3.5 μΩ cm. In contrast to the apparent increase in grain size in the conventional Ag-4Pd wire under electrical stressing with a current density of 1.23 × 105 A/cm2 for various times, the grains in this annealing-twinned wire grow much more slowly. The breaking load and elongation of this annealing-twinned Ag-4Pd wire are also higher than those of conventional wire. Furthermore, annealing twins increase the durability to electromigration of this Ag-4Pd wire under electrical stressing with various current densities.

  2. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  3. Microstructures of 2219 twin wire welded joints

    Institute of Scientific and Technical Information of China (English)

    Xu Wenli; Li Qingfen; Meng Qingguo; Gao Na; Fang Hongyuan

    2005-01-01

    With thick plates of 2219 high-strength alloy, the microstructures of welded joints with twin wire MIG welding were analyzed. Experimental results show that no hot crack was found in the weld due to discontinuous distribution of cocrystallization with low melting temperature, but porosity is serious in the first weld seam that is mainly composed of equiaxial grains with uneven sizes. As the poor position of the whole welded joint, fusion zone has big and coarse grains,uneven microstructures ; In quenching zone, there exist a lot of soaked microstructures that cocrystallization with low melting temperature solute into matrix, thus strengthening the metal in this zone; In excessive aging zone, much more phases that distribute evenly will be separated from the matrix; Outside this zone, properties and microstructures of the metal are basically similar to matrix due to the relatively low temperature or unaffected heat in the zone during welding.

  4. Electromagnetic Characteristic of Twin-wire Indirect Arc Welding

    Institute of Scientific and Technical Information of China (English)

    SHI Chuanwei; ZOU Yong; ZOU Zengda; WU Dongting

    2015-01-01

    Traditional welding methods are limited in low heat input to workpiece and high welding wire melting rate. Twin-wire indirect arc(TWIA) welding is a new welding method characterized by high melting rate and low heat input. This method uses two wires:one connected to the negative electrode and another to the positive electrode of a direct-current(DC) power source. The workpiece is an independent, non-connected unit. A three dimensional finite element model of TWIA is devised. Electric and magnetic fields are calculated and their influence upon TWIA behavior and the welding process is discussed. The results show that with a 100 A welding current, the maximum temperature reached is 17 758 K, arc voltage is 14.646 V while maximum current density was 61 A/mm2 with a maximum Lorene force of 84.5mN. The above mentioned arc parameters near the cathode and anode regions are far higher than those in the arc column region. The Lorene force is the key reason for plasma velocity direction deviated and charged particles flowed in the channel formed by the cathode, anode and upper part of arc column regions. This led to most of the energy being supplied to the polar and upper part of arc column regions. The interaction between electric and magnetic fields is a major determinant in shaping TWIA as well as heat input on the workpiece. This is a first study of electromagnetic characteristics and their influences in the TWIA welding process, and it is significant in both a theoretical and practical sense.

  5. Buoyant Helical Twin-Axial Wire Antenna

    Science.gov (United States)

    2016-11-15

    Wire Antenna” by the inventor, David A. Tonn. STATEMENT OF GOVERNMENT INTEREST [0002] The invention described herein may be manufactured and used by...BACKGROUND OF THE INVENTION (1) Field of the Invention [0003] The present invention is directed to a linear antenna for dual frequencies and a method for...curves and hinders the submarine’s operations when using the antenna. SUMMARY OF THE INVENTION [0006] It is a first object of the present

  6. Quality Designed Twin Wire Arc Spraying of Aluminum Bores

    Science.gov (United States)

    König, Johannes; Lahres, Michael; Methner, Oliver

    2015-01-01

    After 125 years of development in combustion engines, the attractiveness of these powerplants still gains a great deal of attention. The efficiency of engines has been increased continuously through numerous innovations during the last years. Especially in the field of motor engineering, consequent friction optimization leads to cost-effective fuel consumption advantages and a CO2 reduction. This is the motivation and adjusting lever of NANOSLIDE® from Mercedes-Benz. The twin wire arc-spraying process of the aluminum bore creates a thin, iron-carbon-alloyed coating which is surface-finished through honing. Due to the continuous development in engines, the coating strategies must be adapted in parallel to achieve a quality-conformed coating result. The most important factors to this end are the controlled indemnification of a minimal coating thickness and a homogeneous coating deposition of the complete bore. A specific system enables the measuring and adjusting of the part and the central plunging of the coating torch into the bore to achieve a homogeneous coating thickness. Before and after measurement of the bore diameter enables conclusions about the coating thickness. A software tool specifically developed for coating deposition can transfer this information to a model that predicts the coating deposition as a function of the coating strategy.

  7. Integrated Electrical Wire Insulation Repair System

    Science.gov (United States)

    Williams, Martha; Jolley, Scott; Gibson, Tracy; Parks, Steven

    2013-01-01

    An integrated system tool will allow a technician to easily and quickly repair damaged high-performance electrical wire insulation in the field. Low-melt polyimides have been developed that can be processed into thin films that work well in the repair of damaged polyimide or fluoropolymer insulated electrical wiring. Such thin films can be used in wire insulation repairs by affixing a film of this low-melt polyimide to the damaged wire, and heating the film to effect melting, flow, and cure of the film. The resulting repair is robust, lightweight, and small in volume. The heating of this repair film is accomplished with the use of a common electrical soldering tool that has been modified with a special head or tip that can accommodate the size of wire being repaired. This repair method can furthermore be simplified for the repair technician by providing replaceable or disposable soldering tool heads that have repair film already "loaded" and ready for use. The soldering tool heating device can also be equipped with a battery power supply that will allow its use in areas where plug-in current is not available

  8. Microstructural evolution and deformation behavior of twinning-induced plasticity (TWIP) steel during wire drawing

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Joong-Ki [Graduate Institute of Ferrous Technology, POSTECH, Pohang 790-784 (Korea, Republic of); Steel Products Research Group, Technical Research Laboratories, POSCO, Pohang 790-785 (Korea, Republic of); Yi, Il-Cheol [Graduate Institute of Ferrous Technology, POSTECH, Pohang 790-784 (Korea, Republic of); Son, Il-Heon; Yoo, Jang-Yong [Steel Products Research Group, Technical Research Laboratories, POSCO, Pohang 790-785 (Korea, Republic of); Kim, Byoungkoo [Materials Technology Development Team, DHIC, Changwon 642-792 (Korea, Republic of); Zargaran, A. [Graduate Institute of Ferrous Technology, POSTECH, Pohang 790-784 (Korea, Republic of); Kim, Nack J., E-mail: njkim@postech.ac.kr [Graduate Institute of Ferrous Technology, POSTECH, Pohang 790-784 (Korea, Republic of)

    2015-09-17

    The effect of wire drawing on the microstructural evolution and deformation behavior of Fe–Mn–Al–C twinning-induced plasticity (TWIP) steel has been investigated. The inhomogeneities of the stress state, texture, microstructure, and mechanical properties were clarified over the cross section of drawn wire with the aid of numerical simulation, Schmid factor analysis, and electron backscatter diffraction (EBSD) techniques. The analysis of texture in drawn wire shows that a mixture of <111> and <100> fiber texture was developed with strain; however, the distribution of <111> and <100> fibers was inhomogeneous along the radial direction of wire due to uneven strain distribution and different stress state along the radial direction. It has also been shown that the morphology, volume fraction, and variant system of twins as well as twinning rate were dependent on the imposed stress state. The surface area was subjected to larger strain and more complex stress state involving compression, shear, and tension than the center area, resulting in a larger twin volume fraction and more twin variants in the former than in the latter at all the strain levels. While the surface area was saturated with twins at an early stage of drawing, the center area was not saturated with twins even at fracture, implying that the fracture of wire were initiated at the surface area because of the exhaustion of ductility due to twinning. Based on these results, it is suggested that imposing a uniform strain distribution along the radial direction of wire by the control of processing conditions such as die angle and amount of reduction per pass is necessary to increase the drawing limit of TWIP steel.

  9. EVALUATION OF INDUCTANCE WITH ELECTRICAL WIRES

    Directory of Open Access Journals (Sweden)

    V. Kudry

    2016-08-01

    Full Text Available In this paper proved the possibility of developing passive electronic inductive elements based replace metal wire that is wound inductor, the wire is made of electret. The relative permeability of the electret S  10 000, several orders of magnitude greater than the permeability of conventional insulation materials, i < 10, resulting current in the wire acquires properties bias current. The essence of innovation is to replace the source of of magnetic induction flow that pervades the core of the coil. According to the theory of electrodynamics, current bias, in contrast to conduction current, generated no movement of charge along the wire, but the change of the charge in the local volume.Equivalence bias current and conduction current is manifested in the possibility of forming a magnetic field. The flow through magnetic induction coil core regardless of the current it generates, creates voltage at its ends.The paper also shows the numeric characteristics that determine the effective frequency range, specified the reason why electric a wire with і < 10 can not generate magnetic flux through the core and serve as a passive reactive component.

  10. Arc Interference Behavior during Twin Wire Gas Metal Arc Welding Process

    Directory of Open Access Journals (Sweden)

    Dingjian Ye

    2013-01-01

    Full Text Available In order to study arc interference behavior during twin wire gas metal arc welding process, the synchronous acquisition system has been established to acquire instantaneous information of arc profile including dynamic arc length variation as well as relative voltage and current signals. The results show that after trailing arc (T-arc is added to the middle arc (M-arc in a stable welding process, the current of M arc remains unchanged while the agitation increases; the voltage of M arc has an obvious increase; the shape of M arc changes, with increasing width, length, and area; the transfer frequency of M arc droplet increases and the droplet itself becomes smaller. The wire extension length of twin arc turns out to be shorter than that of single arc welding.

  11. Micro-mechanical properties of 2219 welded joints with twin wire welding

    Institute of Scientific and Technical Information of China (English)

    Xu Wenli; Li Qingfen; Meng Qingguo; Fang Hongyuan; Gao Na

    2006-01-01

    Nanoindentation method was adopted to investigate the distribution regularities of micro-mechanical properties of 2219 twin wire welded joints, thus providing the necessary theoretical basis and guidance for joint strengthening and improvement of welding procedure.Experimental results show that in weld zone, micro-mechanical properties are seriously uneven.Both hardness and elastic modulus distribute as uneven sandwich layers, while micro-mechanical properties in bond area are much more uniform than weld zone;In heat-affected zone of 2219 twin wire welded joint, distribution regularity of hardness is similar to elastic modulus.The average hardness in quenching zone is higher than softening zone, and the average elastic modulus in solid solution zone is slightly higher than softening zone.As far as the whole welded joint is concerned,metal in weld possesses the lowest hardness.For welded specimens without reinforcement, fracture position is the weld when tensioning.While for welded specimens with reinforcement, bond area is the poorest position with joint strength coefficient of 61%.So, it is necessary to strengthen the poor positions-weld and bond area of 2219 twin wire welded joint in order to solve joint weakening of welding this kind of alloy.

  12. Twin-wire Submerged Arc Welding Process of a High-strength Low-alloy Steel

    Institute of Scientific and Technical Information of China (English)

    YANG Xiuzhi; XU Qinghua; YIN Niandong; XIAO Xinhua

    2011-01-01

    The measurement of thermal cycle curves of a high-strength low-alloy steel (HSLA)subjected twin-wire submerged arc welding (SAW) was introduced. The thermal simulation test was performed by using the obtained curves. The impact toughness at -50 ℃ temperature of the simulated samples was also tested. OM, SEM and TEM of the heat-affected zone (HAZ) of some simulation specimens were investigated. The results showed that the HSLA endured the twin-wire welding thermal cycle, generally, the low-temperature toughness values of each part of HAZ was lower than that of the parent materials, and the microstructure of coarse-grained zone(CGHAZ) mainly made up of granular bainite is the reason of the toughness serious deterioration. Coarse grain, grain boundary carbide extract and M-A island with large size and irregular polygon, along the grain boundary distribution, are the reasons for the toughness deterioration of CGHAZ. The research also showed that selected parameters of twin-wire SAW can meet the requirements to weld the test steel.

  13. Electric Effect of Impurity in Square Quantum Wires

    Institute of Scientific and Technical Information of China (English)

    LI Kui-Hua; ZHANG Ying-Tao; LI You-Cheng

    2004-01-01

    @@ In the presence of an electric fidd perpendicular to the axes of the wire, the binding energy of shallow donor impurity in finite square quantum well wires is calculated. For different impurity positions and aspect ratios of the wires, we investigate the Stark shift of the 1s-like state energy of the impurity by expanding the wavefunction into a two-dimensional Fourier series and by using the variational scheme.

  14. EFFECTS OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM

    Directory of Open Access Journals (Sweden)

    S. K. SINHA

    2010-11-01

    Full Text Available WEDM is very useful wherever complex geometry with tight tolerances needs to be generated on hard materials. In view of modern and sophisticated technology readily available these days, the expectation of accuracy in WEDM is ever-increasing, and therefore, techniques for the improvement in WEDM must be developed. The main cause of inaccuracy is wire-lag, the cause and effect of which is described in the present work, along with a technique to obviate the problem in straight cutting. In a subsequent paper, a software approach (since the problem gets too complicated for improvement of accuracy in contour cutting is described.

  15. Corrosion Preventative Compounds (CPCs) Effect on Aircraft Electrical Wiring Components

    Science.gov (United States)

    2011-08-01

    Electrical Wiring Components TR285HN301 Final Report Revision: - • Fretting research project was performed on nano -miniature connectors...CPCs, including gold plated edge card connectors, electrical connectors, tin plated pins, nano -miniature connectors. Current Air Force and NAVAIR...early 1980’s on many Navy aircraft. The Navy’s standard wire type. M5086/2-20 c Polyvinyl chloride, polyamide jacket, glass fiber braid ( PVC /glass

  16. REMEDY OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM

    Directory of Open Access Journals (Sweden)

    S. K. SINHA

    2010-12-01

    Full Text Available WEDM is extensively used these days for generating complex geometries with tight tolerances on difficult-tomachine materials. Therefore, demand for improvement in precision has been ever increasing. The main source of inaccuracy is wire-lag, the cause and effect of which is well-known. Research has been going on to overcome this drawback. So far, the techniques suggested for improvement in accuracy are, in general, based on monitoring the machining process at hardware-level, which is not only tedious but involves extra expenditure also. In the present paper, a software approach for improvement in accuracy is described, which does not require any additional investment on the machine, and still gives very good results.

  17. Self-healable electrically conducting wires for wearable microelectronics.

    Science.gov (United States)

    Sun, Hao; You, Xiao; Jiang, Yishu; Guan, Guozhen; Fang, Xin; Deng, Jue; Chen, Peining; Luo, Yongfeng; Peng, Huisheng

    2014-09-01

    Electrically conducting wires play a critical role in the advancement of modern electronics and in particular are an important key to the development of next-generation wearable microelectronics. However, the thin conducting wires can easily break during use, and the whole device fails to function as a result. Herein, a new family of high-performance conducting wires that can self-heal after breaking has been developed by wrapping sheets of aligned carbon nanotubes around polymer fibers. The aligned carbon nanotubes offer an effective strategy for the self-healing of the electric conductivity, whereas the polymer fiber recovers its mechanical strength. A self-healable wire-shaped supercapacitor fabricated from a wire electrode of this type maintained a high capacitance after breaking and self-healing.

  18. Numerical model for electrical explosion of copper wires in water

    Science.gov (United States)

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

    2016-11-01

    This paper presents a simple but quite accurate numerical model for analyzing electrical explosion of copper wires in water. The numerical model solves a circuit equation coupled with one-dimensional magneto-hydrodynamic (MHD) equations with the help of appropriate wide-range equation of state (EOS) and electrical conductivity for copper. The MHD equations are formulated in a Lagrangian form to identify the interface between the wire and surrounding water clearly. A quotidian EOS (QEOS) that is known as the simplest form of EOS is utilized to build wide-range EOS for copper. In the QEOS, we consider the liquid-vapor phase transition, which is critical in analyzing the wire explosion system. For the electrical conductivity of copper, a semi-empirical set of equations covering from solid state to partially ionized plasma state are employed. Experimental validation has been performed with copper wires of various diameters, which are exploded by a microsecond timescale pulsed capacitive discharge. The simulation results show excellent agreements with the experimental results in terms of temporal motions of a plasma channel boundary and a shock front as well as current and voltage waveforms. It is found that the wire explodes (vaporizes) along the liquid branch of a binodal curve irrespective of wire dimension and operating voltage. After the explosion, the wire becomes a plasma state right away or after the current pause (dwell), depending on the operating conditions. It is worth noting that such a peculiar characteristic of wire explosion, i.e., current pause and restrike, is well simulated with the present numerical model. In particular, it is shown that the wire cools down along the vapor branch of the binodal curve during the current dwell, due to a significant difference of thermodynamic characteristics across the binodal curve. The influence of radiation for studying nonideal plasmas with a wire explosion technique and a physical process for shock wave formation

  19. Flame spread over inclined electrical wires with AC electric fields

    KAUST Repository

    Lim, Seung J.

    2017-07-21

    Flame spread over polyethylene-insulated electrical wires was studied experimentally with applied alternating current (AC) by varying the inclination angle (θ), applied voltage (VAC), and frequency (fAC). For the baseline case with no electric field applied, the flame spread rate and the flame width of downwardly spreading flames (DSFs) decreased from the horizontal case for −20° ≤ θ < 0° and maintained near constant values for −90° ≤ θ < −20°, while the flame spread rate increased appreciably as the inclination angle of upwardly spreading flames (USFs) increased. When an AC electric field was applied, the behavior of flame spread rate in DSFs (USFs) could be classified into two (three) sub-regimes characterized by various functional dependences on VAC, fAC, and θ. In nearly all cases of DSFs, a globular molten polyethylene formed ahead of the spreading flame edge, occasionally dripping onto the ground. In these cases, an effective flame spread rate was defined to represent the burning rate by measuring the mass loss due to dripping. This effective spread rate was independent of AC frequency, while it decreased linearly with voltage and was independent of the inclination angle. In DSFs, when excessively high voltage and frequency were applied, the dripping led to flame extinction during propagation and the extinction frequency correlated well with applied voltage. In USFs, when high voltage and frequency were applied, multiple globular molten PEs formed at several locations, leading to ejections of multiple small flame segments from the main flame, thereby reducing the flame spread rate, which could be attributed to the electrospray phenomenon.

  20. Wire electric-discharge machining and other fabrication techniques

    Science.gov (United States)

    Morgan, W. H.

    1983-01-01

    Wire electric discharge machining and extrude honing were used to fabricate a two dimensional wing for cryogenic wind tunnel testing. Electric-discharge cutting is done with a moving wire electrode. The cut track is controlled by means of a punched-tape program and the cutting feed is regulated according to the progress of the work. Electric-discharge machining involves no contact with the work piece, and no mechanical force is exerted. Extrude hone is a process for honing finish-machined surfaces by the extrusion of an abrasive material (silly putty), which is forced through a restrictive fixture. The fabrication steps are described and production times are given.

  1. Development of Rotary Axis For Wire Electrical Discharge Machining (WEDM

    Directory of Open Access Journals (Sweden)

    M. Parthiban, C. Manigandan, G. Muthu Venkadesh, M. Ranjith Kumar

    2013-08-01

    Full Text Available This paper gives an overview of setting up a rotary axis to the existing WEDM machine to investigate the machining parameters in WEDG of harder materials. There are a number of hybrid machining processes (HMPs seeking the combined advantage of EDM and other machining techniques. One such combination is wire electrical discharge grinding (WEDG, which is commonly used for micro-machining of fine and hard rods. WEDG employs a single wire guide to confine the wire tension within the discharge area between the rod and the front edge of the wire and also to minimize the wire vibration. Other advantages of WEDG include the ability to machine hard- to- machine materials with large aspect ratio.

  2. Detection System Design of Electric Vehicle Wiring Harness

    Institute of Scientific and Technical Information of China (English)

    SUN Jian-Xin; LI Xiao-Peng

    2015-01-01

    This paper introduces a method of harness testing system for electric vehicle wiring harness wiring .The system has implemented some commonly used electric wiring harness state detection using the way of the upper machine and lower machine communicate with each other, Such as normal, open circuit, short circuit, fault, etc. And then the lower machine send the wiring harness status to the upper machine, and then the upper machine parses the line state, and at the same time shows the test results, And then stores the test results in the database. After all, we can call at any time to check the date and the results of detection. It changes the traditional manual test mode of operation and Implements the detection process of automation and intellectualization.

  3. Effects of process parameters on arc shape and penetration in twin-wire indirect arc welding

    Institute of Scientific and Technical Information of China (English)

    Shun-shan ZHANG; Mei-qing CAO; Dong-ting WU; Zeng-da ZOU

    2009-01-01

    In this study, the effects of variable parameters on arc shape and depth of penetration in twin-wire indirect arc gas shielded welding were investigated. The variation of arc shape caused by changes of the parameters was recorded by a high-speed camera,and the depths of penetration of specimen were measured after bead welding by an optical microscope. Experiments indicated that proper parameters give birth to a concentrated and compressed welcimg arc, which Would increase the depth of penetration as the incensement of the arc foice Several pnncipal parameters including toe distance ot twin wires intersecting point to base metal,the included angle,and the content of shielding gas were determined. The arc turned more concentrated and the depth of penetration increased obviously as the welding current increased,the arc turned brighter while unobvlous change of penetration occurred as the arc voltage increased,and the deepest penetration was obtained when the welding speed was 10.5 mm/s..

  4. Measurement of electrical conductivity of micron-scale metallic wires

    Institute of Scientific and Technical Information of China (English)

    JU Bing-feng; JU Yang

    2006-01-01

    Electrical conductivities of micron-scale aluminum wires were quantitatively measured by a four-point atomic force microscope (AFM) probe. This technique is a combination of the principles of the four-point probe method and standard AFM. This technique was applied to the 99.999% aluminum wires with 350 nm thickness and different widths of 5.0,25.0 and 50.0 μm. Since the small dimensions of the wires,the geometrical effects were discussed in details. Experiment results show that the four-point AFM probe is mechanically flexible and robust. The four-point AFM probe technique is capable of measuring surface topography together with local electrical conductivity simultaneously. The repeatable measurements indicate that this technique could be used for fast in-situ electrical properties characterization of sensors and microelectromechanical system devices.

  5. 75 FR 78979 - Application to Export Electric Energy; Twin Rivers Paper Company Inc.

    Science.gov (United States)

    2010-12-17

    ... Application to Export Electric Energy; Twin Rivers Paper Company Inc. AGENCY: Office of Electricity Delivery.... (Twin Rivers) has applied for authority to transmit electric energy from the United States to Canada... authority to transmit electric energy from the United States to Canada over the existing...

  6. Composite ceramic superconducting wires for electric motor applications

    Science.gov (United States)

    Halloran, John W.

    1990-07-01

    Several types of HTSC wire have been produced and two types of HTSC motors are being built. Hundreds of meters of Ag- clad wire were fabricated from YBa2Cu3O(7-x) (Y-123) and Bi2Ca2Sr2Cu3O10 (BiSCCO). The dc homopolar motor coils are not yet completed, but multiple turns of wire have been wound on the coil bobbins to characterize the superconducting properties of coiled wire. Multifilamentary conductors were fabricated as cables and coils. The sintered polycrystalline wire has self-field critical current densities (Jc) as high as 2800 A/sq cm, but the Jc falls rapidly with magnetic field. To improve Jc, sintered YBCO wire is melt textured with a continuous process which has produced textures wire up to 0.5 meters long with 77K transport Jc above 11, 770 A/sq cm2 in self field and 2100 A/sq cm2 at 1 telsa. The Emerson Electric dc homopolar HTSC motor has been fabricated and run with conventional copper coils. A novel class of potential very powerful superconducting motors have been designed to use trapped flux in melt textures Y-123 as magnet replicas in an new type of permanent magnet motor. The stator element and part of the rotor of the first prototype machine exist, and the HTSC magnet replica segments are being fabricated.

  7. Enhancing GMI properties of melt-extracted Co-based amorphous wires by twin-zone Joule annealing

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.S.; Cao, F.Y.; Xing, D.W.; Zhang, L.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Qin, F.X. [Advanced Composite Center for Innovation and Science (ACCIS), Department of Aerospace Engineering, University of Bristol, University Walk, Bristol BS8 1TR (United Kingdom); Peng, H.X. [Advanced Composite Center for Innovation and Science (ACCIS), Department of Aerospace Engineering, University of Bristol, University Walk, Bristol BS8 1TR (United Kingdom); Centre for Nanoscience and Quantum Information, University of Bristol, Tyndall Avenue, Bristol BS8 1FD (United Kingdom); Xue, X. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Sun, J.F., E-mail: jfsun_hit@263.net [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer GMI effect is closely related to annealed microstructures observed by HRTEM. Black-Right-Pointing-Pointer Twin-zone Joule-heated annealing (TJHA) as a novel effective annealing treatment. Black-Right-Pointing-Pointer TJHA wires have relatively larger GMI ratio and field sensitivity. Black-Right-Pointing-Pointer From HRTEM perspective to explain the GMI peaks feature of different states wires. Black-Right-Pointing-Pointer TJHA wires are useful for high-resolution magnetic sensor applications. - Abstract: The influence of twin-zone Joule annealing (TJA) on the microstructure and magnetic properties of melt-extracted Co{sub 68.2}Fe{sub 4.3}B{sub 15}Si{sub 12.5} amorphous microwires has been investigated. Experimental results indicated that twin-zone Joule annealing treatment improved the GMI property of as-cast wires to a greater extent comparing with Joule annealing (JA) and conventional vacuum annealing (CVA) techniques. At 15 MHz, e.g., the maximum GMI ratio [{Delta}Z/Z{sub 0}]{sub max} of a TJA wire increases to 104.29%, which is more than 5 times of 20.49% for the as-cast wire, nearly two times of 56.47% for the JA wire, while the CVA wire has a decreased GMI ratio; the field response sensitivity of the TJA wire increased to 171.62%/Oe from 80.32%/Oe for the as-cast wire, exceeding the values of 140.76%/Oe for the JA wire and of 39.17%/Oe for the CVA wire. The stress or structural relaxation in TJA wire increases circumferential permeability, and magnetic moment achieves a critical state of excitation for overcoming eddy-current damping or 'nail-sticked' action in rotational magnetization process at relatively high frequency. From the microstructural point of view, the role of regularly arranged atomic micro-regions (RAAM) and of medium range order region (MROR) determines the efficiency of various annealing techniques. Conclusively, TJA is established as an efficient annealing technique to enhance the GMI effect

  8. The Effect of Process Parameters on Twin Wire Arc Spray Pattern Shape

    Directory of Open Access Journals (Sweden)

    Allison Lynne Horner

    2015-04-01

    Full Text Available A design of experiments approach was used to describe process parameter—spray pattern relationships in the Twin Wire Arc process using zinc feed stock in a TAFA 8835 (Praxair, Concord, NH, USA spray torch. Specifically, the effects of arc current, primary atomizing gas pressure, and secondary atomizing gas pressure on spray pattern size, spray pattern flatness, spray pattern eccentricity, and coating deposition rate were investigated. Process relationships were investigated with the intent of maximizing or minimizing each coating property. It was determined that spray pattern area was most affected by primary gas pressure and secondary gas pressure. Pattern eccentricity was most affected by secondary gas pressure. Pattern flatness was most affected by primary gas pressure. Coating deposition rate was most affected by arc current.

  9. Trade Electricity. Signal Wiring--Level 1. Standardized Curriculum.

    Science.gov (United States)

    New York City Board of Education, Brooklyn, NY. Office of Occupational and Career Education.

    This curriculum guide consists of nine modules on signal wiring, one of the three divisions of the standardized trade electricity curriculum in high schools in New York City. The modules cover the following subjects: bells, double contact pushbuttons, annunciator circuits, open circuit burglar alarms, closed circuit burglar alarms, fire alarms,…

  10. Rapid Prototyping of Electrically Small Spherical Wire Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2014-01-01

    It is shown how modern rapid prototyping technologies can be applied for quick and inexpensive, but still accurate, fabrication of electrically small wire antennas. A well known folded spherical helix antenna and a novel spherical zigzag antenna have been fabricated and tested, exhibiting...

  11. Established and Adapted Diagnostic Tools for Investigation of a Special Twin-Wire Arc Spraying Process

    Science.gov (United States)

    König, Johannes; Lahres, Michael; Zimmermann, Stephan; Schein, Jochen

    2016-10-01

    In the LDS® ( Lichtbogendrahtspritzen) process, a twin-wire arc spraying (TWAS) process developed by Daimler AG, the gas injection and feed to the arc play a crucial role in separating the molten particles from the wire ends. This paper describes an investigation of the gas and particle behavior according to individual LDS® process parameters. Coating problems are not considered. The measurements are separated into two different parts: "cold" (without arc and particles) and "hot" (with arc and particles). The results provide the first detailed understanding of the effect of different LDS® process parameters. A correlation between the gas parameter settings and the particle beam properties was found. Using established and adapted diagnostic tools, as also applied for conventional TWAS processes, this special LDS® process was investigated and the results (gas and particle behavior) validated, thereby allowing explanation and comparison of the diagnostic methods, which is the main focus of this paper. Based on error analysis, individual instabilities, limits, and deviations during the gas determinations and particle measurements are explained in more detail. The paper concludes with presentation of the first particle-shadow diagnostic results and main statements regarding these investigations.

  12. Effect of AC electric fields on flame spread over electrical wire

    KAUST Repository

    Kim, Minkuk

    2011-01-01

    The effect of electric fields on the characteristics of flame spread over insulated electrical wire has been investigated experimentally by varying AC voltage and frequency applied to the wire in the normal gravity condition. The polyethylene (PE) insulated electrical wire was placed horizontally on electrically non-conducting posts and one end of the wire was connected to the high voltage terminal. Thus, the electrical system is the single electrode configuration. The wire was ignited at one end and the flame spread rate along the wire has been measured from the images using a video camera. Two distinct regimes existed depending on the applied AC frequency. In the low frequency regime, the flame spread rate decreased with the frequency and voltage. While in the high frequency regime, it decreased initially with voltage and then increased. At high frequency, the spread rate was even over that without applying electric fields. This result implies that fire safety codes developed without considering the effect of electric fields may require modifications. © 2010 Published by Elsevier Inc. on behalf of The Combustion Institute. All rights reserved.

  13. 75 FR 65052 - Consensus Standards, Standard Practice for Maintenance of Airplane Electrical Wiring Systems

    Science.gov (United States)

    2010-10-21

    ... Practice for Maintenance of Airplane Electrical Wiring Systems (Standard Practice) as an acceptable means... FAA finds the standards to be acceptable methods and procedures for maintenance of electrical wiring... Practice for Maintenance of Airplane Electrical Wiring Systems. FOR FURTHER INFORMATION CONTACT:...

  14. Operational environments for electrical power wiring on NASA space systems

    Science.gov (United States)

    Stavnes, Mark W.; Hammoud, Ahmad N.; Bercaw, Robert W.

    1994-01-01

    Electrical wiring systems are used extensively on NASA space systems for power management and distribution, control and command, and data transmission. The reliability of these systems when exposed to the harsh environments of space is very critical to mission success and crew safety. Failures have been reported both on the ground and in flight due to arc tracking in the wiring harnesses, made possible by insulation degradation. This report was written as part of a NASA Office of Safety and Mission Assurance (Code Q) program to identify and characterize wiring systems in terms of their potential use in aerospace vehicles. The goal of the program is to provide the information and guidance needed to develop and qualify reliable, safe, lightweight wiring systems, which are resistant to arc tracking and suitable for use in space power applications. This report identifies the environments in which NASA spacecraft will operate, and determines the specific NASA testing requirements. A summary of related test programs is also given in this report. This data will be valuable to spacecraft designers in determining the best wiring constructions for the various NASA applications.

  15. Nanopowder production by gas-embedded electrical explosion of wire

    Institute of Scientific and Technical Information of China (English)

    Zou Xiao-Bing; Mao Zhi-Guo; Wang Xin-Xin; Jiang Wei-Hua

    2013-01-01

    A small electrical explosion of wire (EEW) setup for nanopowder production is constructed.It consists of a low inductance capacitor bank of 2 μF--4 μF typically charged to 8 kV-30 kV,a triggered gas switch,and a production chamber housing the exploding wire load and ambient gas.With the EEW device,nanosize powders of titanium oxides,titanium nitrides,copper oxides,and zinc oxides are successfully synthesized.The average particle size of synthesized powders under different experimental conditions is in a range of 20 nm-80 nm.The pressure of ambient gas or wire vapor can strongly affect the average particle size.The lower the pressure,the smaller the particle size is.For wire material with relatively high resistivity,such as titanium,whose deposited energy Wd is often less than sublimation energy Ws due to the flashover breakdown along the wire prematurely ending the Joule heating process,the synthesized particle size of titanium oxides or titanium nitrides increases with overheat coefficient k (k =Wd/Ws) increasing.

  16. Spherical magnetic nanoparticles fabricated by electric explosion of wire

    Science.gov (United States)

    Kurlyandskaya, G. V.; Bhagat, S. M.; Safronov, A. P.; Beketov, I. V.; Larrañaga, A.

    2011-12-01

    We report the first use of an electrophysical method of electric explosion of wire for preparing magnetic nanoparticles of iron oxide. X-ray diffraction, transmission electron microscopy, magnetization and magnetic resonance measurements were comparatively analyzed. They indicated that the shape of magnetic nanoparticles is close to being spherical. The production order of 100g per hour by this method is advantageous when a large amount of material is needed for applications.

  17. Analysis of an Underground Vertical Electrically Small Wire Antenna

    Directory of Open Access Journals (Sweden)

    Shuwei Dong

    2015-01-01

    Full Text Available The problem considered is a vertical electrically small wire antenna located underground, which transmits electromagnetic signals to the ground. Getting Green’s function of the vertical dipole underground was the first step to calculate this issue. A quasistatic situation was considered to make an approximation on Sommerfeld integral for easy solution. The method of moments was used to solve the current distribution on the antenna surface at different frequencies, which laid a good foundation for obtaining the electric field of the antenna. Then the axial and radial components of the electric field with the radial distance on the ground were investigated, as well as the voltage received on the ground. Furthermore, the influence of the frequency and stratum parameters on current and electric field was studied to understand the variation clearly.

  18. Effect of applied DC electric fields in flame spread over polyethylene-coated electrical wire

    KAUST Repository

    Jin, Young Kyu

    2011-03-01

    We experimentally investigated the effect of applied DC electric fields on the flame spread over polyethylene-coated electrical wire. The flame-spread rates over electrical wire with negative and positive DC electric fields from 0 to ±7 kV were measured and analyzed. We compared the results for DC electric fields with previous results for AC electric fields. We explored whether or not various flame shapes could be obtained with DC electric fields and the main reason for the flame-spread acceleration, particularly at the end of the electrical wire, for AC electric fields. We found that DC electric fields do not significantly affect the flame-spread rates. However, the flame shape is mildly altered by the ionic wind effect even for DC electric fields. The flame-spread rate is relevant to the flame shape and the slanted direction in spite of the mild impact. A possible explanation for the flame spread is given by a thermal-balance mechanism and fuel-vapor jet. © 2011 The Korean Society of Mechanical Engineers.

  19. 30 CFR 77.516 - Electric wiring and equipment; installation and maintenance.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric wiring and equipment; installation and maintenance. 77.516 Section 77.516 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.516 Electric wiring and...

  20. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Science.gov (United States)

    2010-01-01

    ... Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems (EWIS) maintenance... unless the maintenance program for that airplane includes inspections and procedures for electrical... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Electrical wiring interconnection...

  1. 14 CFR 26.11 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Electrical wiring interconnection systems (EWIS) maintenance program. 26.11 Section 26.11 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... AIRPLANES Enhanced Airworthiness Program for Airplane Systems § 26.11 Electrical wiring...

  2. Trends in Wire Electrical Discharge Machining (WEDM: A Review

    Directory of Open Access Journals (Sweden)

    Ms. Sharanya S. Nair

    2014-12-01

    Full Text Available The exponential growth of manufacturing industries and production and the increased need of accuracy and precision throws the spotlight on the nontraditional machining processes. The machining of metals and nonmetals having special properties like high strength, high hardness and toughness is done by non- conventional machining methods. Wire electrical discharge machining is one of the earliest non-traditional machining processes. This machining process competes with conventional machining such as milling, broaching, grinding etc. However, its ability to cut extremely intricate and delicate shapes with utmost accuracy makes this process most suitable among all other processes. The otherwise hard to be machined materials like carbides, tungsten, zirconium etc. can be easily machined using this process. This paper reviews notable work done in the field of WEDM by various researchers.

  3. Microstructural Characterization and Wear Properties of Fe-Based Amorphous-Crystalline Coating Deposited by Twin Wire Arc Spraying

    Directory of Open Access Journals (Sweden)

    Ana Arizmendi-Morquecho

    2014-01-01

    Full Text Available Twin wire arc spraying (TWAS was used to produce an amorphous crystalline Fe-based coating on AISI 1018 steel substrate using a commercial powder (140MXC in order to improve microhardness and wear properties. The microstructures of coating were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM as well as the powder precursor. Analysis in the coating showed the formation of an amorphous matrix with boron and tungsten carbides randomly dispersed. At high amplifications were identified boron carbides at interface boron carbide/amorphous matrix by TEM. This kind of carbides growth can be attributed to partial crystallization by heterogeneous nucleation. These interfaces have not been reported in the literature by thermal spraying process. The measurements of average microhardness on amorphous matrix and boron carbides were 9.1 and 23.85 GPa, respectively. By contrast, the microhardness values of unmelted boron carbide in the amorphous phase were higher than in the substrate, approaching 2.14 GPa. The relative wear resistance of coating was 5.6 times that of substrate. These results indicate that the twin wire arc spraying is a promising technique to prepare amorphous crystalline coatings.

  4. Effect of reduction of area on microstructure and mechanical properties of twinning-induced plasticity steel during wire drawing

    Science.gov (United States)

    Hwang, Joong-Ki; Son, Il-Heon; Yoo, Jang-Yong; Zargaran, A.; Kim, Nack J.

    2015-09-01

    The effect of reduction of area (RA), 10%, 20%, and 30%, during wire drawing on the inhomogeneities in microstructure and mechanical properties along the radial direction of Fe-Mn-Al-C twinning-induced plasticity steel has been investigated. After wire drawing, the deformation texture developed into the major and minor duplex fiber texture. However, the texture became more pronounced in both center and surface areas as the RA per pass increased. It also shows that a larger RA per pass resulted in a higher yield strength and smaller elongation than a smaller RA per pass at all strain levels. Although inhomogeneities in microstructure and mechanical properties along the radial direction decreased with increasing RA per pass, there existed an optimum RA per pass for maximum drawing limit. Insufficient penetration of strain from surface to center at small RA per pass (e.g., 10%) and high friction and unsound metal flow at large RA per pass (e.g., 30%) all resulted in heterogeneous microstructure and mechanical properties along the radial direction of drawn wire. On the other hand, 20% RA per pass improved the drawing limit by about 30% as compared to the 10% and 30% RAs per pass.

  5. Physical and Electrical Measurements of Different Metals used in Exploding Wires

    Science.gov (United States)

    Valancius, Cole; Bainbridge, Joe; Love, Cody; Richardson, Duane

    2016-11-01

    Implementation of the energy density metric has made it possible to better understand the physics of exploding wires. When applying the energy density metric to exploding wire experiments in a porous material bed, results suggest a link between characteristics of wire materials (e.g. their electrical properties during burst and the physical work done by the bursting wire). Previous work has focused on qualitative comparisons of current and voltage waveforms and the qualitative comparison of Schlieren images of wire shocks in air. In these experiments, the wires were all buried in a porous media allowing the simultaneous capture of accurate current and voltage to observe the energy density at burst, while simultaneously observing the amount of time the wire took to compress the porous media to a 1 mm deep crater. Observing the physical compression of the porous bed in time in concert with the energy density allows a link to be established between the measured electrical signals and the physical work done by the exploding wire. This research allows a more quantitative link to be established between the electrical energy and the physical energy expended by an exploding wire, allowing for the development of more accurate models and a better understanding of exploding wire physics.

  6. The Effect of Twin Grain Boundary Tuned by Temperature on the Electrical Transport Properties of Monolayer MoS2

    OpenAIRE

    Luojun Du; Hua Yu; Li Xie; Shuang Wu; Shuopei Wang; Xiaobo Lu; Mengzhou Liao; Jianling Meng; Jing Zhao; Jing Zhang; Jianqi Zhu; Peng Chen; Guole Wang; Rong Yang; Dongxia Shi

    2016-01-01

    Theoretical calculation and experimental measurement have shown that twin grain boundary (GB) of molybdenum disulphide (MoS2) exhibits extraordinary effects on transport properties. Precise transport measurements need to verify the transport mechanism of twin GB in MoS2. Here, monolayer molybdenum disulphide with a twin grain boundary was grown in our developed low-pressure chemical vapor deposition (CVD) system, and we investigated how the twin GB affects the electrical transport properties ...

  7. Analysis of thermal characteristics of electrical wiring for load groups in cattle barns.

    Science.gov (United States)

    Kim, Doo Hyun; Yoo, Sang-Ok; Kim, Sung Chul; Hwang, Dong Kyu

    2015-01-01

    The purpose of the current study is to analyze the thermal characteristics of electrical wirings depending on the number of operating load by connecting four types of electrical wirings that are selected by surveying the conditions for the electric fans, automatic waterers and halogen warm lamps that were installed in cattle barns in different years. The conditions of 64 cattle barns were surveyed and an experimental test was conducted at a cattle barn. The condition-survey covered inappropriate design, construction and misuse of electrical facility, including electrical wiring mostly used, and the mode of load current was evaluated. The survey showed that the mode of load current increased as the installation year of the fans, waterers and halogen lamps became older. Accordingly, the cattle barn manager needed to increase the capacity of the circuit breaker, which promoted the degradation of insulation of the electrical wires' sheath and increased possibility for electrical fires in the long-run. The test showed that the saturation temperature of the wire insulated sheath increased depending on the installation year of the load groups, in case of VCTFK and VFF electric wires, therefore, requiring their careful usage in the cattle barns.

  8. Review of effects of dielectric coatings on electrical exploding wires and Z pinches

    Science.gov (United States)

    Wu, Jian; Li, Xingwen; Li, Mo; Li, Yang; Qiu, Aici

    2017-10-01

    As the most powerful x-ray source in the laboratories, the wire array Z pinches have been of great relevance to inertial confinement fusions, laboratory astrophysics, and other high-energy density applications. In order to produce x-ray with greater power and higher efficiency, the dynamics of wire array has been investigated extensively, and various methods have been proposed to improve the implosion quality of the wire array. This review focuses on the experimental and theoretical investigations regarding the effects of the dielectric coatings on electrical exploding wires and Z pinches. Since the early 2000, the electrical wire explosion related to the first stage of the wire array Z pinches has been studied extensively, and the results indicated that the dielectric coatings can significantly increase the joule energy deposition into a wire in the initial stage, and even the corona free explosion of tungsten wires can be achieved. Recently, there is an increasing interest in the dynamics of insulated wire array Z pinches. By applying dielectric coatings, the ablation process is suppressed, the x-ray start time is delayed, and the possibility of multi-peak radiation is decreased. This review is organized by the evolution dynamics of wire array Z pinches, and a broad introduction to relevant scientific concepts and various other applications are presented. According to the current research status, the challenges, opportunities and further developments of Z pinch loads using dielectric coatings are proposed to further promote the researches and their applications.

  9. Microstructure of Ni-Al powder and Ni-Al composite coatings prepared by twin-wire arc spraying

    Institute of Scientific and Technical Information of China (English)

    Ji-xiao Wang; Gui-xian Wang; Jing-shun Liu; Lun-yong Zhang; Wei Wang; Ze Li; Qi-xiang Wang; Jian-fei Sun

    2016-01-01

    Ni–Al powder and Ni–Al composite coatings were fabricated by twin-wire arc spraying (TWAS). The microstructures of Ni-5wt%Al powder and Ni-20wt%Al powder were characterized by scanning electronic microscopy (SEM) and energy dispersive spec-troscopy (EDS). The results showed that the obtained particle size ranged from 5 to 50μm. The morphology of the Ni–Al powder showed that molten particles were composed of Ni solid solution, NiAl, Ni3Al, Al2O3, and NiO. The Ni–Al phase and a small amount of Al2O3 parti-cles changed the composition of the coating. The microstructures of the twin-wire-arc-sprayed Ni–Al composite coatings were characterized by SEM, EDS, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results showed that the main phase of the Ni-5wt%Al coating consisted of Ni solid solution and NiAl in addition to a small amount of Al2O3. The main phase of the Ni-20wt%Al coating mainly consisted of Ni solid solution, NiAl, and Ni3Al in addition to a small amount of Al and Al2O3, and NiAl and Ni3Al intermet-allic compounds effectively further improved the final wear property of the coatings. TEM analysis indicated that fine spherical NiAl3 pre-cipitates and a Ni–Al–O amorphous phase formed in the matrix of the Ni solid solution in the original state.

  10. Traveling wire electrode increases productivity of Electrical Discharge Machining /EDM/ equipment

    Science.gov (United States)

    Kotora, J., Jr.; Smith, S. V.

    1967-01-01

    Traveling wire electrode on electrical discharge machining /EDM/ equipment reduces the time requirements for precision cutting. This device enables cutting with a minimum of lost material and without inducing stress beyond that inherent in the material. The use of wire increases accuracy and enables tighter tolerances to be maintained.

  11. Radial electric field 3D modeling for wire arrays driving dynamic hohlraums on Z.

    Energy Technology Data Exchange (ETDEWEB)

    Mock, Raymond Cecil

    2007-06-01

    The anode-cathode structure of the Z-machine wire array results in a higher negative radial electric field (Er) on the wires near the cathode relative to the anode. The magnitude of this field has been shown to anti-correlate with the axial radiation top/bottom symmetry in the DH (Dynamic Hohlraum). Using 3D modeling, the structure of this field is revealed for different wire-array configurations and for progressive mechanical alterations, providing insight for minimizing the negative Er on the wire array in the anode-to-cathode region of the DH. Also, the 3D model is compared to Sasorov's approximation, which describes Er at the surface of the wire in terms of wire-array parameters.

  12. Nanosecond electrical explosion of bare and dielectric coated tungsten wire in vacuum

    Science.gov (United States)

    Wang, Kun

    2017-02-01

    Experiments of the electrical explosion of tungsten wire with and without insulating coatings demonstrate that the insulating coatings exert a significant influence on the exploding characteristics. The shadowgraphy and interferometry diagnostics are applied to present the morphology of the exploding products. In the experiments, energy of ˜3.2 eV/atom is deposited into the bare tungsten wire at the instant of voltage breakdown, giving a velocity of 0.38 km/s for the high density core. The value and structure of the energy deposition for the tungsten wire explosions are substantially improved by employing the thin dielectric coatings. Energy of ˜15.2 eV/atom is deposited into the coated tungsten wire transforming the wire into gaseous state and the expanding velocity of the high density core is 5.64 km/s. The interference phase shift and atomic density are reconstructed from the interferogram for the exploding coated tungsten wire.

  13. Effects of grain boundaries on electrical property of copper wires

    Institute of Scientific and Technical Information of China (English)

    严文; 陈建; 范新会

    2003-01-01

    By means of annealing at different temperatures, the copper wires with various numbers of grain boundaries were achieved. And the resistivity of copper wires was measured. The results show that with increasing the number of grain boundaries, the resistivity of copper wires increases, the relationship between the number of grain boundaries and the resistivity of cooper wires can be expressed as y=1.86×10-8e-0.90/x. Unlike dislocation and lattice vacant sites, the curve of the grain boundary vs the resistivity is not linear. Grain boundary controls the general trend of the curve, but the type and the quantity of impurity controls the details of the curve.

  14. Experimental study on the effects of AC electric fields on flame spreading over polyethylene-insulated electric-wire

    KAUST Repository

    Jin, Young Kyu

    2010-11-01

    In this present study, we experimentally investigated the effects of electric fields on the characteristics of flames spreading over electric-wires with AC fields. The dependence of the rate at which a flame spreads over polyethylene-insulated wires on the frequency and amplitude of the applied AC electric field was examined. The spreading of the flame can be categorized into linear spreading and non-linearly accelerated spreading of flame. This categorization is based on the axial distribution of the field strength of the applied electric field. The rate at which the flame spreads is highly dependent on the inclined direction of the wire fire. It could be possible to explain the spreading of the flame on the basis of thermal balance. © 2010 The Korean Society of Mechanical Engineers.

  15. 14 CFR 129.111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Electrical wiring interconnection systems (EWIS) maintenance program. 129.111 Section 129.111 Aeronautics and Space FEDERAL AVIATION... ENGAGED IN COMMON CARRIAGE Continued Airworthiness and Safety Improvements § 129.111 Electrical...

  16. Joining characteristics of titanium-based orthodontic wires connected by laser and electrical welding methods.

    Science.gov (United States)

    Matsunaga, Junko; Watanabe, Ikuya; Nakao, Noriko; Watanabe, Etsuko; Elshahawy, Waleed; Yoshida, Noriaki

    2015-01-01

    This study investigated the possibility of electrical and laser welding to connect titanium-based alloy (beta-titanium and nickel-titanium) wires and stainless-steel or cobalt-chromium alloy wires for fabrication of combination arch-wires. Four kinds of straight orthodontic rectangular wires (0.017 × 0.025 inch) were used: stainless-steel (S-S), cobalt-chromium (Co-Cr), beta-titanium alloy (β-Ti), and nickel-titanium (Ni-Ti). Homogeneous and heterogeneous end-to-end joints (15 mm long each) were made by electrical welding and laser welding. Non-welded wires (30 mm long) were also used as a control. Maximum loads at fracture (N) and elongation (%) were measured by conducting tensile test. The data (n = 10) were statistically analyzed using analysis of variance/Tukey test (P welding and those of the S-S/S-S and Co-Cr/Co-Cr specimens welded by laser. On the other hand, the laser-welded Ni-Ti/Ni-Ti and β-Ti/β-Ti specimens exhibited higher values of the ML and EL compared to those of the corresponding specimens welded by electrical method. In the heterogeneously welded combinations, the electrically welded Ni-Ti/S-S, β-Ti/S-S and β-Ti/Co-Cr specimens showed significantly (P welded by laser. Electrical welding exhibited the higher values of maximum load at fracture and elongation for heterogeneously welded combinations than laser-welding.

  17. Measurement of interfacial toughness of metal film wire and polymer membrane through electricity induced buckling method.

    Science.gov (United States)

    Wang, Qinghua; Xie, Huimin; Lu, Jian; Chen, Pengwan; Zhang, Qingming

    2011-06-15

    Measurement of interfacial toughness of a metal film wire and a flexible substrate is a challenging issue for evaluating the interfacial bonding capacity of the film-wire/substrate systems. In this paper, an electricity induced buckling method is proposed to measure the interfacial toughness between a metal film wire and a polymer membrane, which does not use a pre-existing weak interface. This method relies on causing a buckling driven delamination of the metal film wire from the polymer membrane, by inducing a compressive stress due to electrification of the film wire. For a sort of structure formed by a constantan film wire and a polymer membrane, the current density range under which the buckling of the film wire will emerge is obtained from experiments. The average interfacial toughness of one typical sample is measured to be 31.6 J/m(2). According to the buckling topographies under different current densities, the interfacial toughness of the constantan film wire and the polymer substrate is found to vary from 10 J/m(2) to 60 J/m(2).

  18. Electrical wire as a foreign body in a male urethra: a case report

    Directory of Open Access Journals (Sweden)

    Stravodimos Konstantinos G

    2009-02-01

    Full Text Available Abstract Introduction Self-inflicted foreign bodies in the male urethra and urinary bladder are an emergency that urologists may rarely have to face. A case of an electrical wire inserted in the male urethra and coiled in the bladder is presented. Case presentation A 53-year-old male presented with the inability to void and bloody urethral discharge after having introduced an electrical wire in his urethra for masturbation 3 hours earlier. He had made several unsuccessful attempts to remove it. Conclusion The variety of these objects may be impressive and removal of the foreign body may be quite challenging requiring imagination and high-level surgical skills., In this case an electrical wire was used and the diagnostic as well as the therapeutic steps for its removal are presented.

  19. New Free Electron Wire for Loss Free Utilization of Electrical Energy and Highly Energy Efficient Electrical Appliances

    Directory of Open Access Journals (Sweden)

    Sabyasachi Haldar

    2014-07-01

    Full Text Available New Free Electrons Wire will enable the use of electrical energy and also energy in various other forms, in a loss free way, at room temperature. Free Electrons confined in vacuum at the order of 10-4 torr or more, at the core of the wire, can move a distance as long as about, to a few kilometers without any collision. The vacuum is maintained in a tube made up of alternate layers of Teflon and Silicon Oxynitride. The columbic repulsion between these free electrons will actually conduct energy without any loss. The free electrons trapped in vacuum tube, should be at a particular density of around 2.02 x 108 electrons per unit area. A metal encapsulation(s over the wire is there to keep the electromagnetic field remain confined within the free electron wire, to make it harmless to the health of living creatures. Apart from loss free energy transportation, the free electron wire is also capable of generating very high electromagnetic field due to the free electrons, simply by removing the metal encapsulation(s, which can be used for various purposes. The materials and techniques adopted will make New Free Electron Wire producible commercially, at the cost of general copper wires.

  20. Ubiquity of chaotic magnetic-field lines generated by three-dimensionally crossed wires in modern electric circuits.

    Science.gov (United States)

    Hosoda, M; Miyaguchi, T; Imagawa, K; Nakamura, K

    2009-12-01

    We investigate simple three-dimensionally crossed wires carrying electric currents which generate chaotic magnetic-field lines (CMFLs). As such wire systems, cross-ring and perturbed parallel-ring wires are studied, since topologically equivalent configurations to these systems can often be found in contemporary electric and integrated circuits. For realistic fundamental wire configurations, the conditions for wire dimensions (size) and current values to generate CMFLs are numerically explored under the presence of the weak but inevitable geomagnetic field. As a result, it is concluded that CMFLs can exist everywhere; i.e., they are ubiquitous in the modern technological world.

  1. The Effect of Twin Grain Boundary Tuned by Temperature on the Electrical Transport Properties of Monolayer MoS2

    Directory of Open Access Journals (Sweden)

    Luojun Du

    2016-09-01

    Full Text Available Theoretical calculation and experimental measurement have shown that twin grain boundary (GB of molybdenum disulphide (MoS2 exhibits extraordinary effects on transport properties. Precise transport measurements need to verify the transport mechanism of twin GB in MoS2. Here, monolayer molybdenum disulphide with a twin grain boundary was grown in our developed low-pressure chemical vapor deposition (CVD system, and we investigated how the twin GB affects the electrical transport properties of MoS2 by temperature-dependent transport studies. At low temperature, the twin GB can increase the in-plane electrical conductivity of MoS2 and the transport exhibits variable-range hopping (VRH, while at high temperature, the twin GB impedes the electrical transport of MoS2 and the transport exhibits nearest-neighbor hopping (NNH. Our results elucidate carrier transport mechanism of twin GB and give an important indication of twin GB in tailoring the electronic properties of MoS2 for its applications in next-generation electronics and optoelectronic devices.

  2. Double-section curvature tunable functional actuator with micromachined buckle and grid wire for electricity delivery

    Science.gov (United States)

    Feng, Guo-Hua; Hou, Sheng-You

    2015-09-01

    This paper presents an ionic polymer metal composite (IPMC)-driven tentacle-like biocompatible flexible actuator with double-section curvature tunability. This actuator, possessing an embedded electrical transmission ability that mimics skeletal muscle nerves in the human body, affords versatile device functions. Novel micromachined copper buckles and grid wires are fabricated and their superiority in electricity delivery and driving the IPMC component with less flexural rigidity is demonstrated. In addition, soft conductive wires realized on a polydimethylsiloxane structure function as electrical signal transmitters. A light-emitting diode integrated with the developed actuator offers directional guiding light ability while the actuator performs a snake-like motion. The electrical conductivity and Young’s modulus of the key actuator components are investigated, and flexural rigidity and dynamic behavior analyses of the actuator under electrical manipulation are elaborated.

  3. Electrically Injected Twin Photon Emitting Lasers at Room Temperature

    Directory of Open Access Journals (Sweden)

    Claire Autebert

    2016-08-01

    Full Text Available On-chip generation, manipulation and detection of nonclassical states of light are some of the major issues for quantum information technologies. In this context, the maturity and versatility of semiconductor platforms are important assets towards the realization of ultra-compact devices. In this paper we present our work on the design and study of an electrically injected AlGaAs photon pair source working at room temperature. The device is characterized through its performances as a function of temperature and injected current. Finally we discuss the impact of the device’s properties on the generated quantum state. These results are very promising for the demonstration of electrically injected entangled photon sources at room temperature and let us envision the use of III-V semiconductors for a widespread diffusion of quantum communication technologies.

  4. Dynamic polarizability of tungsten atoms reconstructed from fast electrical explosion of fine wires in vacuum

    Science.gov (United States)

    Sarkisov, G. S.; Rosenthal, S. E.; Struve, K. W.

    2016-10-01

    Nanosecond electrical explosion of fine metal wires in vacuum generates calibrated, radially expanded gas cylinders of metal atoms surrounded by a low-density fast expanding plasma corona. An integrated-phase technique, based on laser interferometry, provides the dynamic dipole polarizability of metal atoms. These data were previously unavailable for tungsten atoms. An extremely high melting temperature and significant premelt electronic emission make these measurements particularly complicated for this refractory metal. Most attempts to vaporize tungsten wire by electrical current pulse result in the disintegration of the sample into macro- and microfragments. However, application of a very fast-rising current, ˜1 kA /ns , can vaporize a thin 10-15 μm-diameter tungsten wire and generate a calibrated gas-plasma cylinder. Adding a dielectric coating to the wire leads to increased energy deposition to the wire core and a reduction of the surrounding plasma corona. Employing the integrated-phase technique on a fast-exploding coated tungsten wire, we find that the dynamic dipole polarizability of tungsten atoms at a wavelength of 532 nm equals 15 ±1.3 Å3 .

  5. Development of practical high temperature superconducting wire for electric power application

    Science.gov (United States)

    Hawsey, Robert A.; Sokolowski, Robert S.; Haldar, Pradeep; Motowidlo, Leszek R.

    1995-01-01

    The technology of high temperature superconductivity has gone from beyond mere scientific curiousity into the manufacturing environment. Single lengths of multifilamentary wire are now produced that are over 200 meters long and that carry over 13 amperes at 77 K. Short-sample critical current densities approach 5 x 104 A/sq cm at 77 K. Conductor requirements such as high critical current density in a magnetic field, strain-tolerant sheathing materials, and other engineering properties are addressed. A new process for fabricating round BSCCO-2212 wire has produced wires with critical current densities as high as 165,000 A/sq cm at 4.2 K and 53,000 A/sq cm at 40 K. This process eliminates the costly, multiple pressing and rolling steps that are commonly used to develop texture in the wires. New multifilamentary wires with strengthened sheathing materials have shown improved yield strengths up to a factor of five better than those made with pure silver. Many electric power devices require the wire to be formed into coils for production of strong magnetic fields. Requirements for coils and magnets for electric power applications are described.

  6. Department of Energy`s Wire Development Workshop - Superconductivity program for electric systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    The 1996 High-Temperature Superconducting Wire Development Workshop was held on January 31--February 1 at the Crown Plaza Tampa Westshore in Tampa, Florida. The meeting was hosted by Tampa Electric Company and sponsored by the Department of Energy`s Superconductivity Program for Electric Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. Tampa Electric`s Greg Ramon began the meeting by giving a perspective on the changes now occurring in the utility sector. Major program wire development accomplishments during the past year were then highlighted, particularly the world record achievements at Los Alamos and Oak Ridge National Laboratories. The meeting then focussed on three priority technical issues: thallium conductors; AC losses in HTS conductors; and coated conductors on textured substrates. Following in-depth presentations, working groups were formed in each technology area to discuss and critique the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  7. A Methodology to Enable Automatic 3D Routing of Aircraft Electrical Wiring Interconnection Systems

    NARCIS (Netherlands)

    Zhu, Z.; La Rocca, G.; Van Tooren, M.J.L.

    2015-01-01

    Harness 3D routing in aircraft Electrical Wiring Interconnection System (EWIS) design is very complex because of both the intrinsic complexity of EWIS and the increasing number of design constraints. The complexity hinders the improvement of the design efficiency and makes the design error prone. Co

  8. 脉冲电流差值对双丝CO2焊影响%Research on the effect of pulse current difference on the twin - wire CO2 welding

    Institute of Scientific and Technical Information of China (English)

    李钰桢; 彭灿灿; 朱晓军; 岳海瑞; 杨锦辉; 薛家祥

    2014-01-01

    搭建由双丝数字化焊接电源系统组成的焊接工艺平台,通过大量工艺试验,全面测试所设计的双丝电源工艺性能。通过对比分析采集的电压、电流波形和焊缝,进一步确定双丝电流差值对双丝焊接效果的影响规律。实验结果得到最优电流差值范围,使双丝数字化焊接电源能有效实现双丝 CO2焊接,且焊接质量优异。%By utilizing the developed twin - wire digital welding power system,this paper established the welding technological plat-form. Then a large number of technological experiments have been carried out to fully test the designed twin - wire poer process perform-ance. through the contrast analysis the aacquisition of current,voltage waveforms and welding bram,to further determine the tein - wire current difference influence law of twin - wire weding effect. The experiment to get the best range of pulse current difference that the digital twin - wrie welding power system could achieve twin - wire CO2 welding effectively,and the welding quality is excellent.

  9. Experimental Study on Downwardly Spreading Flame over Inclined Polyethylene-insulated Electrical Wire with Applied AC Electric Fields

    KAUST Repository

    Lim, Seung Jae

    2014-12-30

    An experimental study on downwardly spreading flame over slanted electrical wire, which is insulated by Polyethylene (PE), was conducted with applied AC electric fields. The result showed that the flame spread rate decreased initially with increase in inclination angle of wire and then became nearly constant. The flame shape was modified significantly with applied AC electric field due to the effect of ionic wind. Such a variation in flame spread rate could be explained by a thermal balance mechanism, depending on flame shape and slanted direction of flame. Extinction of the spreading flame was not related to angle of inclination, and was described well by a functional dependency upon the frequency and voltage at extinction.

  10. Optimal Modes for the Fabrication of Aluminum Nanopowders by the Electrical Explosion of Wires

    Directory of Open Access Journals (Sweden)

    Alexei Pustovalov

    2017-01-01

    Full Text Available The paper is aimed at studying the impact of initial conditions of electrical explosion of wires on energy characteristics of the explosion and some other properties of the obtained aluminum powders. Explosion modes where the energy input into the wire has the maximal level were found. These modes are optimal for fabrication of powders with the best properties. The powders have the highest value of the specific surface of 14.5 m2/g, a narrow histogram of the particle size distribution, and a narrow distribution histogram with a high polydispersity coefficient of 0.7.

  11. The Characterization of Twin-Wire Arc-Sprayed FeCrBSi Coating and the Application in Sewage Sludge Boilers

    Science.gov (United States)

    Qin, Enwei; Huang, Qian; Shao, Yumin; Chen, Guoxing; Ye, Lin; Gu, Qin; Wu, Shuhui

    2014-12-01

    Incineration in boilers is an environment-friendly treatment for industrial and civil sewage sludge. However, due to the aggressive nature of the sludge, the boiler fireside-surface is subjected to severe wear, erosive, and high temperature corrosion problems during incineration. In this study, we developed an economical FeCrBSi wire material with iron weight content as high as 80%. The coating was prepared by twin-wire arc spraying processing. The chemical compositions of the coating, as well as phase components were analyzed by energy-dispersive spectroscopy and x-ray diffraction method. The surface roughness, porosity, and cross-sectional morphology were further characterized. The coating hardness is close to that of the commercial Armacor M and Armacor C materials. In-boiler test was also carried out. The low thickness loss of the tube indicates a promising application future in sludge boilers.

  12. Hot embossing of electrophoresis microchannels in PMMA substrates using electric heating wires.

    Science.gov (United States)

    Gan, Zhibing; Yu, Zhengyin; Chen, Zhi; Chen, Gang

    2010-04-01

    A simple method based on electric heating wires has been developed for the rapid fabrication of poly(methyl methacrylate) (PMMA) electrophoresis microchips in ordinary laboratories without the need for microfabrication facilities. A piece of stretched electric heating wire placed across the length of a PMMA plate along its midline was sandwiched between two microscope slides under pressure. Subsequently, alternating current was allowed to pass through the wire to generate heat to emboss a separation microchannel on the PMMA separation channel plate at room temperature. The injection channel was fabricated using the same procedure on a PMMA sheet that was perpendicular to the separation channel. The complete microchip was obtained by bonding the separation channel plate to the injection channel sheet, sealing the channels inside. The electric heating wires used in this work not only generated heat; they also served as templates for embossing the microchannels. The prepared microfluidic microchips have been successfully employed in the electrophoresis separation and detection of ions in connection with contactless conductivity detection.

  13. CUTTING REGULARITY AND DISCHARGE CHARACTERISTICS BY USING COMPOSITE COOLING LIQUID IN WIRE CUT ELECTRICAL DISCHARGE MACHINE WITH HIGH WIRE TRAVELING SPEED

    Institute of Scientific and Technical Information of China (English)

    LIU Zhidong

    2008-01-01

    The analysis of cutting regularity is provided through using and comparing two typical cooling liquids. It is proved that cutting regularity is greatly affected by cooling liquid's washing ability. Discharge characteristics and theoretic analysis between two electrodes are also discussed based on discharge waveform. By using composite cooling liquid which has strong washing ability, the efficiency in the first stable cutting phase has reached more than 200 mm2/min, and the roughness of the surface has reached Ra<0.8 μm after the fourth cutting with more than 50 mm2/min average cutting efficiency. It is pointed out that cutting situation of the wire cut electrical discharge machine with high wire traveling speed (HSWEDM) is better than the wire cut electrical discharge machine with low wire traveling speed (LSWEDM) in the condition of improving the cooling liquid washing ability. The machining indices of HSWEDM will be increased remarkably by using the composite cooling liquid.

  14. Electrical Core Transformer for Grid Improvement Incorporating Wire Magnetic Components

    Energy Technology Data Exchange (ETDEWEB)

    Harrie R. Buswell, PhD; Dennis Jacobs, PhD; Steve Meng

    2012-03-26

    The research reported herein adds to the understanding of oil-immersed distribution transformers by exploring and demonstrating potential improvements in efficiency and cost utilizing the unique Buswell approach wherein the unit is redesigned, replacing magnetic sheet with wire allowing for improvements in configuration and increased simplicity in the build process. Exploration of new designs is a critical component in our drive to assure reduction of energy waste, adequate delivery to the citizenry, and the robustness of U.S. manufacturing. By moving that conversation forward, this exploration adds greatly to our base of knowledge and clearly outlines an important avenue for further exploration. This final report shows several advantages of this new transformer type (outlined in a report signed by all of our collaborating partners and included in this document). Although materials development is required to achieve commercial potential, the clear benefits of the technology if that development were a given is established. Exploration of new transformer types and further work on the Buswell design approach is in the best interest of the public, industry, and the United States. Public benefits accrue from design alternatives that reduce the overall use of energy, but it must be acknowledged that new DOE energy efficiency standards have provided some assurance in that regard. Nonetheless the burden of achieving these new standards has been largely shifted to the manufacturers of oil-immersed distribution transformers with cost increasing up to 20% of some units versus 2006 when this investigation was started. Further, rising costs have forced the industry to look closely are far more expensive technologies which may threaten U.S. competitiveness in the distribution transformer market. This concern is coupled with the realization that many units in the nation's grid are beyond their optimal life which suggests that the nation may be headed for an infrastructure

  15. Electrical explosion of Al and Ag wires in air at different pressures

    Science.gov (United States)

    Sarkisov, G. S.; Caplinger, J.; Parada, F.; Sotnikov, V. I.

    2016-09-01

    Experiments with electrically exploding fine Al and Ag wires in air demonstrate a strong dependence of the expanding metal core condition and velocity on ambient pressure. Expansion velocity of the wire core varies by 23 times between ˜0.2 km/s and ˜4.6 km/s. The shock-wave velocity at atmospheric pressure is ˜5 km/s and increases to ˜6 km/s when the pressure is decreased to 50 Torr. The condition of the metal core is strongly dependent on material and whether it is expanding into vacuum or against ambient air pressure. Expansion velocity of the fine Al and Ag wires for different surrounding pressures in general agree with Paschen's Law for air gap.

  16. In vitro toxicity evaluation of silver soldering, electrical resistance, and laser welding of orthodontic wires.

    Science.gov (United States)

    Sestini, Silvia; Notarantonio, Laura; Cerboni, Barbara; Alessandrini, Carlo; Fimiani, Michele; Nannelli, Pietro; Pelagalli, Antonio; Giorgetti, Roberto

    2006-12-01

    The long-term effects of orthodontic appliances in the oral environment and the subsequent leaching of metals are relatively unknown. A method for determining the effects of various types of soldering and welding, both of which in turn could lead to leaching of metal ions, on the growth of osteoblasts, fibroblasts, and oral keratinocytes in vitro, is proposed. The effects of cell behaviour of metal wires on osteoblast differentiation, expressed by alkaline phosphatase (ALP) activity; on fibroblast proliferation, assayed by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenil)-2H-tetrazolium-phenazine ethosulphate method; and on keratinocyte viability and migration on the wires, observed by scanning electron microscopy (SEM), were tested. Two types of commercially available wires normally used for orthodontic appliances, with a similar chemical composition (iron, carbon, silicon, chromium, molybdenum, phosphorus, sulphur, vanadium, and nitrogen) but differing in nickel and manganese content, were examined, as well as the joints obtained by electrical resistance welding, traditional soldering, and laser welding. Nickel and chromium, known as possible toxic metals, were also examined using pure nickel- and chromium-plated titanium wires. Segments of each wire, cut into different lengths, were added to each well in which the cells were grown to confluence. The high nickel and chromium content of orthodontic wires damaged both osteoblasts and fibroblasts, but did not affect keratinocytes. Chromium strongly affected fibroblast growth. The joint produced by electrical resistance welding was well tolerated by both osteoblasts and fibroblasts, whereas traditional soldering caused a significant (P < 0.05) decrease in both osteoblast ALP activity and fibroblast viability, and prevented the growth of keratinocytes in vitro. Laser welding was the only joining process well tolerated by all tested cells.

  17. Pneumatic artificial rubber muscle using shape-memory polymer sheet with embedded electrical heating wire

    Science.gov (United States)

    Takashima, Kazuto; Sugitani, Kazuhiro; Morimoto, Naohiro; Sakaguchi, Seiya; Noritsugu, Toshiro; Mukai, Toshiharu

    2014-12-01

    Shape-memory polymer (SMP) can be deformed by applying a small load above its glass transition temperature (Tg). Shape-memory polymer maintains its shape after it has cooled below Tg and returns to a predefined shape when subsequently heated above Tg. The reversible change in the elastic modulus between the glassy and rubbery states of an SMP can be on the order of several hundred times. Based on the change in stiffness of the SMP in relation to the change in temperature, the present study attempts to evaluate the application of the SMP to soft actuators of a robot. In order to control the temperature of the SMP, we developed an SMP sheet with an embedded electrical heating wire. We formed a uniform, thin SMP sheet without air bubbles using a heat press. The SMP sheet with a heating wire can be heated quickly and can be maintained at a constant temperature. Moreover, the effects of the embedded wire on the mechanical properties in bending and tensile tests were small. Then, we applied the SMP sheet with the embedded electrical heating wire to a pneumatic artificial rubber muscle. The enhanced versatility of SMP sheet applications is demonstrated through a series of experiments conducted using a prototype. The initial shape and bending displacement of the pneumatic artificial rubber muscle can be changed by controlling the temperature of the SMP sheet.

  18. External electric field effect on exciton binding energy in InGaAsP/InP cylindrical quantum wires

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hailong, E-mail: hlwang@mail.qfnu.edu.cn [College of Physics and Engineering, Qufu Normal University, Qufu 273165 (China); Wang, Wenjuan [College of Physics and Engineering, Qufu Normal University, Qufu 273165 (China); Gong, Qian; Wang, Shumin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

    2016-12-15

    Exciton binding energies in InGaAsP/InP cylindrical quantum wires are calculated through variational method under the framework of effective-mass envelope-function approximation. It is shown that the variation of exciton binding energy is highly dependent on radius of the wire, material composition and external electric field. Exciton binding energy is a non-monotonic function of wire radius. It increases until it reaches a maximum, and then decreases as the wire radius decreases. With the increase of In composition, the wire radius need increase to reach the maximum value of exciton binding energy. It is also found that the external electric field has little effect on exciton binding energy. However, the excitonic effect will be destroyed when external electric field is large enough. In addition, the Stark shift of exciton binding energy is also calculated.

  19. Experimental investigation on the energy deposition and expansion rate under the electrical explosion of aluminum wire in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Zongqian; Wang, Kun; Shi, Yuanjie; Wu, Jian; Han, Ruoyu [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

    2015-12-28

    Experimental investigations on the electrical explosion of aluminum wire using negative polarity current in vacuum are presented. Current pulses with rise rates of 40 A/ns, 80 A/ns, and 120 A/ns are generated for investigating the influence of current rise rate on energy deposition. Experimental results show a significant increase of energy deposition into the wire before the voltage breakdown with the increase of current rise rate. The influence of wire dimension on energy deposition is investigated as well. Decreasing the wire length allows more energy to be deposited into the wire. The energy deposition of a 0.5 cm-long wire explosion is ∼2.5 times higher than the energy deposition of a 2 cm-long wire explosion. The dependence of the energy deposition on wire diameter demonstrates a maximum energy deposition of 2.7 eV/atom with a diameter of ∼18 μm. Substantial increase in energy deposition is observed in the electrical explosion of aluminum wire with polyimide coating. A laser probe is applied to construct the shadowgraphy, schlieren, and interferometry diagnostics. The morphology and expansion trajectory of exploding products are analyzed based on the shadowgram. The interference phase shift is reconstructed from the interferogram. Parallel dual wires are exploded to estimate the expansion velocity of the plasma shell.

  20. Electrically tunable Fano-type resonance of an asymmetric metal wire pair.

    Science.gov (United States)

    Fu, Quanhong; Zhang, Fuli; Fan, Yuancheng; He, Xuan; Qiao, Tong; Kong, Botao

    2016-05-30

    We theoretically and experimentally investigate the electrically tunable Fano-type resonance of asymmetric metal wire pair loaded with varactor diodes. It is illustrated that Fano-type transmission spectrum with high quality factor Q appears as a result of interference between the dipole and quadrupole modes. The ohmic loss of series resistance in varactor diode makes major contribution to absorption. At the Fano-type resonance frequency, both the two metal wires exhibit the strongest electric resonance simultaneously, and the Fano-type resonance manifests a large group delay. As the bias voltage ranges from 0 V to 8 V, the Fano-type resonance frequency exhibits a prominent blueshift of 0.16 GHz and the transmission experiences a modulation with a modulation depth of 97%.

  1. Strategic Optimization and Investigation Effect Of Process Parameters On Performance Of Wire Electric Discharge Machine (WEDM

    Directory of Open Access Journals (Sweden)

    ATUL KUMAR

    2012-06-01

    Full Text Available Wire electrical discharge machining (WEDM is widely used in machining of conductive materials when precision is of primary significance. Wire-cut electric discharge machining of Skd 61alloy has been considered in the present work. Experimentation has been completed by using Taguchi’s L18 (21x37 orthogonal array under different conditions of parameters. Optimal combinations of parameters were obtained by this technique. The study shows that with the minimum number of experiments the complete problem can be solvedwhen compared to full factorial design. Experimental results make obvious that the machining model is proper and the Taguchi’s method satisfies the practical conditions. The results obtained are analyzed for the selection of an optimal combination of WEDM parameters for proper machining of Skd 61 alloy to achieve better surface finish. Different analysis was made on the data obtained from the experiments.

  2. New devices for flow measurements: Hot film and burial wire sensors, infrared imagery, liquid crystal, and piezo-electric model

    Science.gov (United States)

    Mcree, Griffith J., Jr.; Roberts, A. Sidney, Jr.

    1991-01-01

    An experimental program aimed at identifying areas in low speed aerodynamic research where infrared imaging systems can make significant contributions is discussed. Implementing a new technique, a long electrically heated wire was placed across a laminar flow. By measuring the temperature distribution along the wire with the IR imaging camera, the flow behavior was identified.

  3. Influence of a cold deformation process by drawing on the electrical properties of copper wires

    Directory of Open Access Journals (Sweden)

    Rafael da Silva Bernardo

    Full Text Available Abstract This article presents a study of the drawing, deformation, hardening and heat treatment of copper wire, in order to investigate the influence of combinations of operating variables (annealing factor, oil emulsion temperature and machine speed during the drawing process on the electrical conductivity of copper wires. The results showed that when the metal is deformed, the value of electrical conductivity suffers a decrease due to the hardening phenomenon. Because of this, it is necessary to heat treat the material. So, it was observed that the annealing factor, which is associated with the thermal treatment temperature, showed a high degree of correlation with the electrical conductivity. This fact is explained by the annealing factor which is responsible for the intensity of the heat treatment. The speed at which the drawing occurs also showed a direct correlation with electric conductivity because the higher the value, the greater the heat treatment temperature and consequently, the greater the electrical conductivity of the material. On the other hand, it had not been possible to establish a conclusion about the correlation between the electrical conductivity and oil emulsion temperature during the drawing process.

  4. 16th edition IEE wiring regulations design and verification of electrical installations

    CERN Document Server

    Scaddan, Brian

    1995-01-01

    This book builds on the basic knowledge and techniques covered in 16th Edition IEE Wiring Regulations Explained and Illustrated, providing the information and revision materials needed for the City & Guilds 2400 (Design, Erection and Verification ofElectrical Installations) exam. All Qualifying Managers will be required to gain this qualification, and Brian Scaddan's book is the ideal text for all students undertaking C&G 2400 courses.

  5. Precision power generator system for a single-wire electric power transmission

    OpenAIRE

    2014-01-01

    The article contains an example of the construction of precision oscillator operating frequency based of the chip AD 9832 company Аnalog Devices that implements the method of direct digital synthesis (DDS) and high-frequency power circuit for a system of single-wire electric power transmission which supports functions digital installations of the operating frequency.The use of DDS frequency synthesizer allows you to build a precision oscillator with a unique digital certainty: the signal gene...

  6. Study on the recycling of waste PVC compounds from electrical wires

    Energy Technology Data Exchange (ETDEWEB)

    Roman Jr, Celso, E-mail: romancelso@gmail.com; Zattera, Ademir José, E-mail: romancelso@gmail.com [Center for Exact Sciences and Technology (CCET), University of Caxias do Sul (UCS), Caxias do Sul-RS (Brazil)

    2014-05-15

    The good mechanical, thermal and electrical properties of poly (vinyl chloride) (PVC) make it a polymer used in many applications, among which is the coating of wires and cables. The processing of PVC for this application is made using the extrusion process. The PVC waste resulting from extrusion can be recycled or placed on landfills. The objective of this work is to develop recycling methods to decrease the amount of PVC stored in landfills. This work evaluated the influence of successive processing of PVC on the final properties of the obtained compound, which will be used in the process of coating wire and cable by extrusion. The mechanical properties of the electrical wires were assessed according to the Brazilian Association of Technical Standards (ABNT NBR 6251). Tests of tensile strength, elongation at break, before and after thermal aging in an oven with air circulation for a period of 168 hours at 100 °C were performed. The degradation of the PVC compound was carried out through Fourier transform infrared spectroscopy (FTIR) and mechanical properties evaluation. The results showed that the compound can be reprocessed five times keeping the minimum requirements of the ABNT NBR 6251 Standard. Reprocessing was stopped upon color changing (yellowing) of the compound. Yellowing is a characteristic degradation behavior by dehydrochlorination of PVC. FTIR analysis showed changes at 1600 cm{sup −1}, 1430 cm{sup −1}, 685 cm{sup −1} and 614 cm{sup −1} bands. The performance of the PVC compound for coating electrical wire and cable was fair, meeting the requirements of the ABNT NBR 6251 Standard even after five reprocessing cycles.

  7. Fabrication and Electrical Characteristics of Individual ZnO Submicron-Wire Field-Effect Transistor

    Institute of Scientific and Technical Information of China (English)

    JIANG Wei; GAO Hong; XU Ling-Ling

    2012-01-01

    Fabrication and electrical characteristics of individual ZnO submicro-wire field-effect transistors (FETs) are investigated by a simple micro-grid template method.The fabricated back-gate ZnO submicro-wire FET is characterized at room temperature in air.The gate voltage Vgs curves reveal gating effect characteristic of n-type conductivity.The field effect mobility of the ZnO submicro-wire is determined to be 7.9cm2/V.s at Vds =2 V,the capacitance and transconductance are estimated to be about 3.9fF and 15.5nS,respectively.UV sensitive property is measured using a 325-nm laser as the excitation source.Compared to the result carried in darkness,the ZnO submicro-wire FET is sensitive to UV irradiation,which indicates its potential application on UV detectors.Experimental results show that the approach introduced here allows the possibility of fabricating low-cost,reliable and flexible microelectronic devices.

  8. Melt quality induced failure of electrical conductor (EC grade aluminum wires

    Directory of Open Access Journals (Sweden)

    Khaliq A.

    2017-01-01

    Full Text Available The failure of electrical conductor grade (EC aluminum during wire drawing process was investigated. The fractured aluminum wires were subjected to Scanning Electron Microscopy (SEM and Energy Dispersive X-ray (EDX analyses for an initial examination. Thermodynamic analyses of molten aluminum interaction with refractories was also carried out using FactSage at 710°C to predict the stable phases. The SEM/EDX analyses has revealed the inclusions in aluminum matrix. The typical inclusions observed were Al2O3, Al3C4 (Al-Carbide and oxides of refractories elements (Al, Mg, Si and O that have particle size ranging up to 5 μm. The transition metal boride particles were not identified during SEM/EDX analyses these might be too fine to be detected with this microscope. The overall investigation suggested that the possible cause of this failure is second phase particles presence as inclusions in the aluminum matrix, and this was associated with the poor quality of melt. During wire drawing process, these inclusions were pulled out of the aluminum matrix by the wiredrawing forces to produce micro-voids which led to ductile tearing and final fracture of wires. It was recommended to use ceramic foam filters to segregate inclusions from molten aluminum.

  9. Generation of extreme state of water by spherical wire array underwater electrical explosion

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, O.; Gilburd, L.; Efimov, S.; Bazalitski, G.; Gurovich, V. Tz.; Krasik, Ya. E. [Physics Department, Technion, Haifa 3200 (Israel)

    2012-10-15

    The results of the first experiments on the underwater electrical explosion of a spherical wire array generating a converging strong shock wave are reported. Using a moderate pulse power generator with a stored energy of {<=}6 kJ and discharge current of {<=}500 kA with a rise-time of {approx}300 ns, explosions of Cu and Al wire arrays of different diameters and with a different number and diameter of wires were tested. Electrical, optical, and destruction diagnostics were used to determine the energy deposited into the array, the time-of-flight of the shock wave to the origin of the implosion, and the parameters of water at that location. The experimental and numerical simulation results indicate that the convergence of the shock wave leads to the formation of an extreme state of water in the vicinity of the implosion origin that is characterized by pressure, temperature, and compression factors of (2 {+-} 0.2) Multiplication-Sign 10{sup 12} Pa, 8 {+-} 0.5 eV, and 7 {+-} 0.5, respectively.

  10. Depollution benchmarks for capacitors, batteries and printed wiring boards from waste electrical and electronic equipment (WEEE)

    Energy Technology Data Exchange (ETDEWEB)

    Savi, Daniel, E-mail: d.savi@umweltchemie.ch [Dipl. Environmental Sci. ETH, büro für umweltchemie, Zurich (Switzerland); Kasser, Ueli [Lic. Phil. Nat. (Chemist), büro für umweltchemie, Zurich (Switzerland); Ott, Thomas [Dipl. Phys. ETH, Institute of Applied Simulation, Zurich University of Applied Sciences, Wädenswil (Switzerland)

    2013-12-15

    Highlights: • We’ve analysed data on the dismantling of electronic and electrical appliances. • Ten years of mass balance data of more than recycling companies have been considered. • Percentages of dismantled batteries, capacitors and PWB have been studied. • Threshold values and benchmarks for batteries and capacitors have been identified. • No benchmark for the dismantling of printed wiring boards should be set. - Abstract: The article compiles and analyses sample data for toxic components removed from waste electronic and electrical equipment (WEEE) from more than 30 recycling companies in Switzerland over the past ten years. According to European and Swiss legislation, toxic components like batteries, capacitors and printed wiring boards have to be removed from WEEE. The control bodies of the Swiss take back schemes have been monitoring the activities of WEEE recyclers in Switzerland for about 15 years. All recyclers have to provide annual mass balance data for every year of operation. From this data, percentage shares of removed batteries and capacitors are calculated in relation to the amount of each respective WEEE category treated. A rationale is developed, why such an indicator should not be calculated for printed wiring boards. The distributions of these de-pollution indicators are analysed and their suitability for defining lower threshold values and benchmarks for the depollution of WEEE is discussed. Recommendations for benchmarks and threshold values for the removal of capacitors and batteries are given.

  11. Secondary recrystallization behavior in a twin-roll cast grain-oriented electrical steel

    Science.gov (United States)

    Song, Hong-Yu; Liu, Hai-Tao; Wang, Yin-Ping; Wang, Guo-Dong

    2017-04-01

    The microstructure and texture evolution along the processing was investigated with a particular focus on the secondary recrystallization behavior in a 0.23 mm-thick twin-roll cast grain-oriented electrical steel. A striking feature is that Goss orientation originated during twin-roll casting as a result of shear deformation and it was further enhanced during hot rolling and normalizing. After primary recrystallization annealing, a homogeneous microstructure associated with a sharp γ-fiber texture was produced. During secondary recrystallization annealing, the γ-fiber texture was first strengthened and weakened with increasing temperature prior to the onset of secondary recrystallization. Goss grains always exhibited more 20-45° misoriented boundaries than the matrix. The matrix was quite stable during secondary recrystallization with the aid of dense inhibitors. Finally, a complete secondary recrystallization microstructure consisting of large Goss grains was produced. The grain boundary characteristics distribution indicated that the high energy model was responsible for the abnormal growth of Goss grains under the present conditions.

  12. Intelligent electrical harness connector assembly using Bell Helicopter Textron's 'Wire Harness Automated Manufacturing System'

    Science.gov (United States)

    Springer, D. W.

    Bell Helicopter Textron, Incorporated (BHTI) installed two Digital Equipment Corporation PDP-11 computers and an American Can Inc. Ink Jet printer in 1980 as the cornerstone of the Wire Harness Automated Manufacturing System (WHAMS). WHAMS is based upon the electrical assembly philosophy of continuous filament harness forming. This installation provided BHTI with a 3 to 1 return-on-investment by reducing wire and cable identification cycle time by 80 percent and harness forming, on dedicated layout tooling, by 40 percent. Yet, this improvement in harness forming created a bottle neck in connector assembly. To remove this bottle neck, BHTI has installed a prototype connector assembly cell that integrates the WHAMS' data base and innovative computer technologies to cut harness connector assembly cycle time. This novel connector assembly cell uses voice recognition, laser identification, and animated computer graphics to help the electrician in the correct assembly of harness connectors.

  13. Universal temperature crossover behavior of electrical conductance in a single oligothiophene molecular wire.

    Science.gov (United States)

    Lee, See Kei; Yamada, Ryo; Tanaka, Shoji; Chang, Gap Soo; Asai, Yoshihiro; Tada, Hirokazu

    2012-06-26

    We have observed and analyzed a universal temperature crossover behavior of electrical conductance in a single oligothiophene molecular wire. The crossover between the Arrhenius-type temperature dependence at high temperature and the temperature-invariant behavior at low temperature is found at a critical molecular wire length of 5.6 nm, where we found a change from the exponential length dependence to the length-invariant behavior. We have derived a scaling function analysis for the origin of the crossover behavior. After assuring that the analysis fits the explanation of the Keldysh Green's function calculation for the temperature dependence, we have applied it to our experimental results and found successfully that our scaling function gives a universal description of the temperature dependence for all over the temperature range.

  14. Optimal synthesis and characterization of Ag nanofluids by electrical explosion of wires in liquids

    Directory of Open Access Journals (Sweden)

    Won Lee Seung

    2011-01-01

    Full Text Available Abstract Silver nanoparticles were produced by electrical explosion of wires in liquids with no additive. In this study, we optimized the fabrication method and examined the effects of manufacturing process parameters. Morphology and size of the Ag nanoparticles were determined using transmission electron microscopy and field-emission scanning electron microscopy. Size and zeta potential were analyzed using dynamic light scattering. A response optimization technique showed that optimal conditions were achieved when capacitance was 30 μF, wire length was 38 mm, liquid volume was 500 mL, and the liquid type was deionized water. The average Ag nanoparticle size in water was 118.9 nm and the zeta potential was -42.5 mV. The critical heat flux of the 0.001-vol.% Ag nanofluid was higher than pure water.

  15. STUDY ON FLUX CORED WIRE FOR ELECTRIC ARC SPRAYING AND PROPERTIES OF COATING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    According to the characteristics of electric arc sp raying technology and abrasion of boiler piping,a fluxcored wire SMD 45 for el ectric arc spraying is developedThe experimental results show that the surface hardness of the coating reaches 60~65 HR and the adhesive strength between the coating and base is 23~28 MPaThe wearability of the coating sprayed by the w ire is 5 times than that of ordinary steel pipeApplying the wire to the heated surface,the life of the economizer pipe is doubly increasedNo local desquamat ion,rust and abrasion can be examined during more than one year's service

  16. High Power Diode Laser-Treated HP-HVOF and Twin Wire Arc-Sprayed Coatings for Fossil Fuel Power Plants

    Science.gov (United States)

    Mann, B. S.

    2013-08-01

    This article deals with high power diode laser (HPDL) surface modification of twin wire arc-sprayed (TWAS) and high pressure high velocity oxy-fuel (HP-HVOF) coatings to combat solid particle erosion occurring in fossil fuel power plants. To overcome solid particle impact wear above 673 K, Cr3C2-NiCr-, Cr3C2-CoNiCrAlY-, and WC-CrC-Ni-based HVOF coatings are used. WC-CoCr-based HVOF coatings are generally used below 673 K. Twin wire arc (TWA) spraying of Tafa 140 MXC and SHS 7170 cored wires is used for a wide range of applications for a temperature up to 1073 K. Laser surface modification of high chromium stainless steels for steam valve components and LPST blades is carried out regularly. TWA spraying using SHS 7170 cored wire, HP-HVOF coating using WC-CoCr powder, Ti6Al4V alloy, and high chromium stainless steels (X20Cr13, AISI 410, X10CrNiMoV1222, 13Cr4Ni, 17Cr4Ni) were selected in the present study. Using robotically controlled parameters, HPDL surface treatments of TWAS-coated high strength X10CrNiMoV1222 stainless steel and HP-HVOF-coated AISI 410 stainless steel samples were carried out and these were compared with HPDL-treated high chromium stainless steels and titanium alloy for high energy particle impact wear (HEPIW) resistance. The HPDL surface treatment of the coatings has improved the HEPIW resistance manifold. The improvement in HPDL-treated stainless steels and titanium alloys is marginal and it is not comparable with that of HPDL-treated coatings. These coatings were also compared with "as-sprayed" coatings for fracture toughness, microhardness, microstructure, and phase analyses. The HEPIW resistance has a strong relationship with the product of fracture toughness and microhardness of the HPDL-treated HP-HVOF and TWAS SHS 7170 coatings. This development opens up a possibility of using HPDL surface treatments in specialized areas where the problem of HEPIW is very severe. The HEPIW resistance of HPDL-treated high chromium stainless steels and

  17. Enhanced Electrical Conductivity in Extruded Single-Wall Carbon Nanotube Wires from Modified Coagulation Parameters and Mechanical Processing.

    Science.gov (United States)

    Bucossi, Andrew R; Cress, Cory D; Schauerman, Christopher M; Rossi, Jamie E; Puchades, Ivan; Landi, Brian J

    2015-12-16

    Single-wall carbon nanotubes (SWCNTs) synthesized via laser vaporization have been dispersed using chlorosulfonic acid (CSA) and extruded under varying coagulation conditions to fabricate multifunctional wires. The use of high purity SWCNT material based upon established purification methods yields wires with highly aligned nanoscale morphology and an over 4× improvement in electrical conductivity over as-produced SWCNT material. A series of eight liquids have been evaluated for use as a coagulant bath, and each coagulant yielded unique wire morphology based on its interaction with the SWCNT-CSA dispersion. In particular, dimethylacetamide as a coagulant bath is shown to fabricate highly uniform SWCNT wires, and acetone coagulant baths result in the highest specific conductivity and tensile strength. A 2× improvement in specific conductivity has been measured for SWCNT wires following tensioning induced both during extrusion via increased coagulant bath depth and during solvent evaporation via mechanical strain, over that of as-extruded wires from shallower coagulant baths. Overall, combination of the optimized coagulation parameters has yielded acid-doped wires with the highest reported room temperature electrical conductivities to date of 4.1-5.0 MS/m and tensile strengths of 210-250 MPa. Such improvements in bulk electrical conductivity can impact the adoption of metal-free, multifunctional SWCNT materials for advanced cabling architectures.

  18. Effect of machining fluid on the process performance of wire electrical discharge machining of nanocomposite ceramic

    Directory of Open Access Journals (Sweden)

    Zhang Chengmao

    2015-01-01

    Full Text Available Wire electric discharge machining (WEDM promise to be effective and economical techniques for the production of tools and parts from conducting ceramic blanks. However, the manufacturing of nanocomposite ceramics blanks with these processes is a long and costly process. This paper presents a new process of machining nanocomposite ceramics using WEDM. WEDM uses water based emulsion, polyvinyl alcohol and distilled water as the machining fluid. Machining fluid is a primary factor that affects the material removal rate and surface quality of WEDM. The effects of emulsion concentration, polyvinyl alcohol concentration and distilled water of the machining fluid on the process performance have been investigated.

  19. Acoustic patterning for 3D embedded electrically conductive wire in stereolithography

    Science.gov (United States)

    Erdem Yunus, Doruk; Sohrabi, Salman; He, Ran; Shi, Wentao; Liu, Yaling

    2017-04-01

    In this paper, we reported a new approach for particle assembly with acoustic tweezers during three-dimensional (3D) printing, for the fabrication of embedded conductive wires with 3D structures. A hexagon shaped acoustic tweezer was incorporated with a digital light processing based stereolithography printer to pattern conductive lines via aligning and condensing conductive nanoparticles. The effect of filler content on electrical resistivity and pattern thickness were studied for copper, magnetite nanoparticles, and carbon nanofiber reinforced nanocomposite samples. The obtained data was later used to produce examples of conductive 3D microstructures and embedded electronic components by using the suggested method.

  20. Spin–orbit interaction effect on nonlinear optical rectification of quantum wire in the presence of electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Manoj [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Lahon, Siddhartha, E-mail: sid.lahon@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Department of Physics, Kirori Mal College, University of Delhi, Delhi 110007 (India); Jha, Pradip Kumar [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Department of Physics, DDU College, University of Delhi, Delhi 110007 (India); Gumber, Sukirti; Mohan, Man [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2014-04-01

    Here we have investigated the influence of external electric field and magnetic field on the nonlinear optical rectification of a parabolic confinement wire in the presence of Rashba spin–orbit interaction. We have used density matrix formulation for obtaining optical properties within the effective mass approximation. The results are presented as a function of quantum wire radius, electric field, magnetic field, Rashba spin–orbit interaction strength and photon energy. Our results indicate an increase of electric field gives the red-shift of the peak positions of nonlinear optical rectification. The role of confinement strength and spin–orbit interaction strength as control parameters on this nonlinear property have been demonstrated.

  1. Optimization of Process Parameters in Wire Electrical Discharge Machining of MMC: A Review

    Directory of Open Access Journals (Sweden)

    J.M.Pujara

    2015-07-01

    Full Text Available Wire electrical discharge machining (WEDM is a specialized thermal machining process capable of accurately machining parts with varying hardness or complex shapes, which have sharp edges that are very difficult to be machined by the main stream machining processes. This practical technology of the WEDM process is based on the conventional EDM sparking phenomenon utilizing the widely accepted non-contact technique of material removal. Since the introduction of the process, WEDM has evolved from a simple means of making tools and dies to the best alternative of producing micro-scale parts with the highest degree of dimensional accuracy and surface finish quality. Metal matrix composites are advanced materials having high specific strength, good wear resistance, and high thermal expansion coefficient. To achieve this task, machining parameters such as pulse on time, pulse off time, peak current, servo voltage, wire feed, wire tension etc. of this process should be selected such that optimal value of their performance measures like Material Removal Rate (MRR, Surface Roughness (SR, Gap current, Dimensional deviation, etc. can be obtained or improved. In past decades, intensive research work had been carried out by different researchers for improvement and optimization of WEDM performance measures using various optimization techniques like Taguchi, Response Surface Methodology (RSM, Artificial Neural Network (ANN, Genetic Algorithm (GA, etc. This paper also highlights the feasibility of the different control strategies of obtaining the optimal machining conditions. This literature review helps to identify the suitable process parameters and their ranges in machining of metal matrix composites.

  2. Research on Modeling and Active Steering Control Algorithm for Electric Forklift Steer-by-Wire System

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-11-01

    Full Text Available In this paper, according to the structure characteristics of steer-by-wire (SBW system for the TFC20 electric forklift, steering dynamics model and two degree of freedom vehicle model are deduced for SBW forklift. Aiming at the free design features of the angular transmission characteristics in the SBW system of electric forklift, the theory of active steering control strategy is studied. After analyzing the influence factors of the angular trans mission ratio of the steering system, the ideal angular transmission ratio is proposed, which is based on the yaw rate gain invariance. Also, the control strategy of the yaw rate feedback and the full state feedback is studied. The simulation results show that the above strategy is effective for the active steering control; it can improve the operating stability and the response speed of the forklift.

  3. Algorithm for Modeling Wire Cut Electrical Discharge Machine Parameters using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    G.Sankara Narayanan

    2014-03-01

    Full Text Available Unconventional machining process finds lot of application in aerospace and precision industries. It is preferred over other conventional methods because of the advent of composite and high strength to weight ratio materials, complex parts and also because of its high accuracy and precision. Usually in unconventional machine tools, trial and error method is used to fix the values of process parameters which increase the production time and material wastage. A mathematical model functionally relating process parameters and operating parameters of a wire cut electric discharge machine (WEDM is developed incorporating Artificial neural network (ANN and the work piece material is SKD11 tool steel. This is accomplished by training a feed forward neural network with back propagation learning Levenberg-Marquardt algorithm. The required data used for training and testing the ANN are obtained by conducting trial runs in wire cut electric discharge machine in a small scale industry from South India. The programs for training and testing the neural network are developed, using matlab 7.0.1 package. In this work, we have considered the parameters such as thickness, time and wear as the input values and from that the values of the process parameters are related and a algorithm is arrived. Hence, the proposed algorithm reduces the time taken by trial runs to set the input process parameters of WEDM and thus reduces the production time along with reduction in material wastage. Thus the cost of machining processes is reduced and thereby increases the overall productivity.

  4. Micro- and nano- second time scale, high power electrical wire explosions in water.

    Science.gov (United States)

    Grinenko, Alon; Efimov, Sergey; Sayapin, Arkadii; Fedotov, Alexander; Gurovich, Viktor; Krasik, Yakov

    2006-10-01

    Experimental and magneto-hydro-dynamic simulation results of micro- and nanosecond time scale underwater electrical Al, Cu and W wires explosions are presented. A capacitor bank with stored energy up to 6 kJ (discharge current up to 80 kA with 2.5 μs quarter period) was used in microsecond time scale experiments and water forming line generator with current amplitude up to 100 kA and pulse duration of 100 ns were used in nanosecond time scale experiments. Extremely high energy deposition of up to 60 times the atomization enthalpy was registered in nanosecond time scale explosions. A discharge channel evolution and surface temperature were analyzed by streak shadow imaging and using fast photo-diode with a set of interference filters, respectively. Microsecond time scale electrical explosion of cylindrical wire array showed extremely high pressure of converging shock waves at the axis, up to 0.2 MBar. A 1D and 2D magneto-hydro-dynamic simulation demonstrated good agreement with such experimental parameters as discharge channel current, voltage, radius, and temperature.

  5. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  6. wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  7. Nonlinear optical rectification in laterally-coupled quantum well wires with applied electric field

    Science.gov (United States)

    Liu, Guanghui; Guo, Kangxian; Zhang, Zhongmin; Hassanbadi, Hassan; Lu, Liangliang

    2017-03-01

    Nonlinear optical rectification coefficient χ0(2) in laterally-coupled AlxGa1-xAs/GaAs quantum well wires with an applied electric field is theoretically investigated using the effective mass approximation as well as the numerical energy levels and wavefunctions of electrons. We find that χ0(2) is greatly influenced by the electric field as well as both the distance and the radius of the coupled system. A blue shift of χ0(2) with increasing electric field is exhibited while a red shift followed by a blue shift with increasing distance or radius is exhibited. A nonmonotonic behavior can be found in the resonant peak values of χ0(2) along with the increase of the electric field, the distance or the radius. One or two of the following physical mechanisms: the increased localization of the ground and first-excited states, the reduced coupling and the reduced quantum confinement effect are applied to elucidate the results above. Our results play a potential role in infrared photodetectors based on the coupled system.

  8. Relationship between energy deposition and shock wave phenomenon in an underwater electrical wire explosion

    Science.gov (United States)

    Han, Ruoyu; Zhou, Haibin; Wu, Jiawei; Qiu, Aici; Ding, Weidong; Zhang, Yongmin

    2017-09-01

    An experimental study of pressure waves generated by an exploding copper wire in a water medium is performed. We examined the effects of energy deposited at different stages on the characteristics of the resulting shock waves. In the experiments, a microsecond time-scale pulsed current source was used to explode a 300-μm-diameter, 4-cm-long copper wire with initial stored energies ranging from 500 to 2700 J. Our experimental results indicated that the peak pressure (4.5-8.1 MPa) and energy (49-287 J) of the shock waves did not follow a simple relationship with any electrical parameters, such as peak voltage or deposited energy. Conversely, the impulse had a quasi-linear relationship with the parameter Π. We also found that the peak pressure was mainly influenced by the energy deposited before separation of the shock wave front and the discharge plasma channel (DPC). The decay time constant of the pressure waveform was affected by the energy injection after the separation. These phenomena clearly demonstrated that the deposited energy influenced the expansion of the DPC and affected the shock wave characteristics.

  9. An experimental investigation of wire electrical discharge machining of hot-pressed boron carbide

    Directory of Open Access Journals (Sweden)

    Ravindranadh Bobbili

    2015-12-01

    Full Text Available The present work discusses the experimental study on wire-cut electric discharge machining of hot-pressed boron carbide. The effects of machining parameters, such as pulse on time (TON, peak current (IP, flushing pressure (FP and spark voltage on material removal rate (MRR and surface roughness (Ra of the material, have been evaluated. These parameters are found to have an effect on the surface integrity of boron carbide machined samples. Wear rate of brass wire increases with rise in input energy in machining of hot-pressed boron carbide. The surfaces of machined samples were examined using scanning electron microscopy (SEM. The influence of machining parameters on mechanism of MRR and Ra was described. It was demonstrated that higher TON and peak current deteriorate the surface finish of boron carbide samples and result in the formation of large craters, debris and micro cracks. The generation of spherical particles was noticed and it was attributed to surface tension of molten material. Macro-ridges were also observed on the surface due to protrusion of molten material at higher discharge energy levels.

  10. Depollution benchmarks for capacitors, batteries and printed wiring boards from waste electrical and electronic equipment (WEEE).

    Science.gov (United States)

    Savi, Daniel; Kasser, Ueli; Ott, Thomas

    2013-12-01

    The article compiles and analyses sample data for toxic components removed from waste electronic and electrical equipment (WEEE) from more than 30 recycling companies in Switzerland over the past ten years. According to European and Swiss legislation, toxic components like batteries, capacitors and printed wiring boards have to be removed from WEEE. The control bodies of the Swiss take back schemes have been monitoring the activities of WEEE recyclers in Switzerland for about 15 years. All recyclers have to provide annual mass balance data for every year of operation. From this data, percentage shares of removed batteries and capacitors are calculated in relation to the amount of each respective WEEE category treated. A rationale is developed, why such an indicator should not be calculated for printed wiring boards. The distributions of these de-pollution indicators are analysed and their suitability for defining lower threshold values and benchmarks for the depollution of WEEE is discussed. Recommendations for benchmarks and threshold values for the removal of capacitors and batteries are given.

  11. Software design of integrative twin-wire pulsed MIG welding based on DSP%基于DSP的一体化双丝脉冲MIG焊机软件设计

    Institute of Scientific and Technical Information of China (English)

    陈晓东; 马前进; 姚屏; 陈辉; 薛家祥

    2012-01-01

    双丝焊具有单丝焊无法比拟的优势,焊接效率高,热输入小,能够满足大电流焊接的需要,但其技术复杂,在国内的研究才刚起步.基于DSP芯片TMS320F2808设计了双丝脉冲MIG焊接核心控制系统,实现了双丝的协同工作,采用增量式数字PI算法实现对焊接电流的控制.对双丝电源进行了硬件调试、软件调试和整机联调,调试结果表明电源的静态特性和动态特性良好,满足双丝系统要求.针对8mm厚的45号钢进行了双丝脉冲MIG焊的双丝脉冲不同相位对比实验.在两路脉冲试验参数匹配合适的情况下,进行了若干组试验,焊接效果良好.%Twin-wire welding has much more advantages than single wire welding.Twin-wire is very efficient in welding and has a small heat input which can suit the big current circumstance.But because of its technical complexity,the research is only just beginning in China.the control system of integrative twin-wire plused power supply based on DSP chip TMS320F2808 was established in this article.Using an incremental digital PI algorithm welding current control.The overall power source testing was done on that platform,including the hardware testing and the software debugging.Then the static characteristics and the instant motive characteristics were both tested,which turned out to be a satisfaction of the Tandem system designed.With twin-wire pulsed MIG welding process for 8mm thick 45 steel, a series of comparative experiments is done, Including twin-wire pulse different phase. Finally good performances and beautiful Tandem welding seams came out,at the premise of the right parameters-matching of the two output pulses.

  12. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  13. Fine-wire electromyography response to neuromuscular electrical stimulation in the triceps surae.

    Science.gov (United States)

    Breen, Paul P; Nene, Anand V; Grace, Pierce A; ÓLaighin, Gearóid

    2015-03-01

    Neuromuscular electrical stimulation (NMES) has previously been used to enhance venous return from the lower leg. By artificially activating lower leg muscles, venous blood may be effectively ejected from the muscle and adjacent veins. It could easily be assumed that combined NMES of the gastrocnemius and soleus would be the most effective single-channel application in this regard, as these muscles represent the largest muscular bulk in the lower leg. However, we have previously reported that soleus stimulation in isolation is substantially more effective. To understand why this is the case, we recorded fine-wire electromyography during NMES of the gastrocnemius and soleus muscles. We found that gastrocnemius and soleus stimulation are effective in eliciting selective stimulation of these muscles. However, combined stimulation of these muscles using a single set of electrodes was only capable in generating ∼ 50% of the response in each muscle, insufficient to generate their theoretical maximum venous return.

  14. Characterization of Cu-Zn Alloy Nanocrystalline Powders Prepared by Wire Electrical Explosion

    Institute of Scientific and Technical Information of China (English)

    WANG Qun; YANG Hai-Bin; GUO Wei-Li; ZOU Guang-Tian

    2000-01-01

    Nanocrystalline powders of Cu-Zn alloy in size ranging from 10 to 140nm was prepared from α-Cu-Zn alloy wire containing 39.8at.% Zn by an electrical explosion method. The particles are identified from x-ray diffraction as a mixture of the α,β,γ, and ε phases of Cu-Zn alloy. Most of the particles are hexagonal in shape, with only a small part being spherical and cubic. The composition of Zn in the explosion products varied from 6.9 to 45.2 at.% in different particles as determined by energy dispersive x-ray spectrometer. A possible mechanism for the formation of the alloy nanocrystalline powders is proposed, in which a redistribution process occurred caused by strong collision and diffusion between the two kinds of atoms during the powder formation.

  15. Calculation of electrical transport properties and electron entanglement in inhomogeneous quantum wires

    Directory of Open Access Journals (Sweden)

    A A Shokri

    2013-10-01

    Full Text Available In this paper, we have investigated the spin-dependent transport properties and electron entanglement in a mesoscopic system, which consists of two semi-infinite leads (as source and drain separated by a typical quantum wire with a given potential. The properties studied include current-voltage characteristic, electrical conductivity, Fano factor and shot noise, and concurrence. The calculations are based on the transfer matrix method within the effective mass approximation. Using the Landauer formalism and transmission coefficient, the dependence of the considered quantities on type of potential well, length and width of potential well, energy of transmitted electron, temperature and the voltage have been theoretically studied. Also, the effect of the above-mentioned factors has been investigated in the nanostructure. The application of the present results may be useful in designing spintronice devices.

  16. Bifurcation Diagram and Pattern Formation of Phase Slip Centers in Superconducting Wires Driven with Electric Currents

    Science.gov (United States)

    Rubinstein, J.; Sternberg, P.; Ma, Q.

    2007-10-01

    We provide here new insights into the classical problem of a one-dimensional superconducting wire exposed to an applied electric current using the time-dependent Ginzburg-Landau model. The most striking feature of this system is the well-known appearance of oscillatory solutions exhibiting phase slip centers (PSC’s) where the order parameter vanishes. Retaining temperature and applied current as parameters, we present a simple yet definitive explanation of the mechanism within this nonlinear model that leads to the PSC phenomenon and we establish where in parameter space these oscillatory solutions can be found. One of the most interesting features of the analysis is the evident collision of real eigenvalues of the associated PT-symmetric linearization, leading as it does to the emergence of complex elements of the spectrum.

  17. H2-norm for mesh optimization with application to electro-thermal modeling of an electric wire in automotive context

    Science.gov (United States)

    Chevrié, Mathieu; Farges, Christophe; Sabatier, Jocelyn; Guillemard, Franck; Pradere, Laetitia

    2017-04-01

    In automotive application field, reducing electric conductors dimensions is significant to decrease the embedded mass and the manufacturing costs. It is thus essential to develop tools to optimize the wire diameter according to thermal constraints and protection algorithms to maintain a high level of safety. In order to develop such tools and algorithms, accurate electro-thermal models of electric wires are required. However, thermal equation solutions lead to implicit fractional transfer functions involving an exponential that cannot be embedded in a car calculator. This paper thus proposes an integer order transfer function approximation methodology based on a spatial discretization for this class of fractional transfer functions. Moreover, the H2-norm is used to minimize approximation error. Accuracy of the proposed approach is confirmed with measured data on a 1.5 mm2 wire implemented in a dedicated test bench.

  18. Microstructure and mechanical properties of twin-wire arc sprayed Ni-Al composite coatings on 6061-T6 aluminum alloy sheet

    Institute of Scientific and Technical Information of China (English)

    Ji-xiao Wang; Jing-shun Liu; Lun-yong Zhang; Jian-fei Sun; Zhi-ping Wang

    2014-01-01

    We have systematically studied the microstructure and mechanical properties of Ni-5wt%Al and Ni-20wt%Al composite coat-ings fabricated on 6061-T6 aluminum alloy sheet by twin-wire arc spraying under different experimental conditions. The abrasive wear be-havior and interface diffusion behavior of the composite coatings were evaluated by dry/wet rubber wheel abrasive wear tests and heat treat-ment, respectively. Experimental results indicate that the composite coatings exhibit features of adhesive wear. Besides, the Vickers micro-hardness of NiAl and Ni3Al intermetallic compounds is relatively larger than that of the substrate, which is beneficial for enhancing the wear resistance. With the increase of annealing temperature and time, the interface diffusion area between the Ni-Al coating and the substrate gradually expands with the formation of NiAl3 and Ni2Al3 phases, and is controlled by diffusion of aluminum atoms. The grain growth ex-ponent n of diffusion kinetics of the Ni-Al coating, calculated via a high-temperature diffusion model at 400, 480, and 550°C, is between 0.28 and 0.38. This satisfies the cubic law, which is consistent with the general theoretical relationship of high-temperature diffusion.

  19. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Directory of Open Access Journals (Sweden)

    Thangam Chinnadurai

    2016-12-01

    Full Text Available This study focuses on investigating the effects of process parameters, namely, Peak current (Ip, Pulse on time (Ton, Pulse off time (Toff, Water pressure (Wp, Wire feed rate (Wf, Wire tension (Wt, Servo voltage (Sv and Servo feed setting (Sfs, on the Material Removal Rate (MRR and Surface Roughness (SR for Wire electrical discharge machining (Wire-EDM of nickel using Taguchi method. Response Surface Methodology (RSM is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used.

  20. Simulation study of solar wind push on a charged wire: basis of solar wind electric sail propulsion

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2007-03-01

    Full Text Available One possibility for propellantless propulsion in space is to use the momentum flux of the solar wind. A way to set up a solar wind sail is to have a set of thin long wires which are kept at high positive potential by an onboard electron gun so that the wires repel and deflect incident solar wind protons. The efficiency of this so-called electric sail depends on how large force a given solar wind exerts on a wire segment and how large electron current the wire segment draws from the solar wind plasma when kept at a given potential. We use 1-D and 2-D electrostatic plasma simulations to calculate the force and present a semitheoretical formula which captures the simulation results. We find that under average solar wind conditions at 1 AU the force per unit length is (5±1×10−8 N/m for 15 kV potential and that the electron current is accurately given by the well-known orbital motion limited (OML theory cylindrical Langmuir probe formula. Although the force may appear small, an analysis shows that because of the very low weight of a thin wire per unit length, quite high final speeds (over 50 km/s could be achieved by an electric sailing spacecraft using today's flight-proved components. It is possible that artificial electron heating of the plasma in the interaction region could increase the propulsive effect even further.

  1. Electrical and Thermal Properties of Twin-Screw Extruded Multiwalled Carbon Nanotube/Epoxy Composites

    Science.gov (United States)

    Karippal, Jeena Jose; Narasimha Murthy, H. N.; Rai, K. S.; Krishna, M.; Sreejith, M.

    2010-11-01

    This paper presents the experimental results of dispersing multiwalled carbon nanotubes (MWNTs) into epoxy (space grade structural adhesive) nanocomposites using co-rotating twin screw extrusion process. Two sets of specimens were prepared; set 1 with ultrasonication for predispersing MWNT before extrusion and set 2 direct dispersion of MWNT in the extruder. MWNT was loaded up to 8 vol.% in both the sets. The specimens were characterized for room temperature volume and surface resistivities as per ASTM D257 using Keithley Model 6517 and for thermal conductivity in the temperature range -50 to 150 °C as per ASTM E 1530 using Thermal Conductivity Instrument (TCI) 2022 SX211. The volume resistivity of sets 1 and 2 decreased to an extent of 1011 and 109 respectively. The surface resistivity drop was of the order of 109 for both the sets. These drops corresponded to the maximum MWNT loading of 8 vol.%. Electrical conductivity values of the specimens were fitted into the Power Law Model to evaluate the critical exponent. Both sets 1 and 2 showed increase in thermal conductivity with increase in temperature in the testing range. Thermal conductivity increased with increase in filler loading and the maximum increase was 60% at 150 °C in case of 8 vol.% MWNT nanocomposites for set 1. The corresponding value for the set 2 was 25%. Thermal conductivity values were predicted using Lewis Nielson model. DSC of the specimens showed increase in glass transition temperature with increase in filler loading. The dispersion of the nanofillers was studied using SEM and the surface morphology using AFM.

  2. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  3. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  4. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  5. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  6. Microscopic Evaluation of Electrical and Thermal Conduction in Random Metal Wire Networks.

    Science.gov (United States)

    Gupta, Ritu; Kumar, Ankush; Sadasivam, Sridhar; Walia, Sunil; Kulkarni, Giridhar U; Fisher, Timothy S; Marconnet, Amy

    2017-04-05

    Ideally, transparent heaters exhibit uniform temperature, fast response time, high achievable temperatures, low operating voltage, stability across a range of temperatures, and high optical transmittance. For metal network heaters, unlike for uniform thin-film heaters, all of these parameters are directly or indirectly related to the network geometry. In the past, at equilibrium, the temperature distributions within metal networks have primarily been studied using either a physical temperature probe or direct infrared (IR) thermography, but there are limits to the spatial resolution of these cameras and probes, and thus, only average regional temperatures have typically been measured. However, knowledge of local temperatures within the network with a very high spatial resolution is required for ensuring a safe and stable operation. Here, we examine the thermal properties of random metal network thin-film heaters fabricated from crack templates using high-resolution IR microscopy. Importantly, the heaters achieve predominantly uniform temperatures throughout the substrate despite the random crack network structure (e.g., unequal sized polygons created by metal wires), but the temperatures of the wires in the network are observed to be significantly higher than the substrate because of the significant thermal contact resistance at the interface between the metal and the substrate. Last, the electrical breakdown mechanisms within the network are examined through transient IR imaging. In addition to experimental measurements of temperatures, an analytical model of the thermal properties of the network is developed in terms of geometrical parameters and material properties, providing insights into key design rules for such transparent heaters. Beyond this work, the methods and the understanding developed here extend to other network-based heaters and conducting films, including those that are not transparent.

  7. Iron oxide nanoparticles fabricated by electric explosion of wire: focus on magnetic nanofluids

    Science.gov (United States)

    Beketov, I. V.; Safronov, A. P.; Medvedev, A. I.; Alonso, J.; Kurlyandskaya, G. V.; Bhagat, S. M.

    2012-06-01

    Nanoparticles of iron oxides (MNPs) were prepared using the electric explosion of wire technique (EEW). The main focus was on the fabrication of de-aggregated spherical nanoparticles with a narrow size distribution. According to XRD the major crystalline phase was magnetite with an average diameter of MNPs, depending on the fraction. Further separation of air-dry EEW nanoparticles was performed in aqueous suspensions. In order to provide the stability of magnetite suspension in water, we found the optimum concentration of the electrostatic stabilizer (sodium citrate and optimum pH level) based on zeta-potential measurements. The stable suspensions still contained a substantial fraction of aggregates which were disintegrated by the excessive ultrasound treatment. The separation of the large particles out of the suspension was performed by centrifuging. The structural features, magnetic properties and microwave absorption of MNPs and their aqueous solutions confirm that we were able to obtain an ensemble in which the magnetic contributions come from the spherical MNPs. The particle size distribution in fractionated samples was narrow and they showed a similar behaviour to that expected of the superparamagnetic ensemble. Maximum obtained concentration was as high as 5 % of magnetic material (by weight). Designed assembly of de-aggregated nanoparticles is an example of on-purpose developed magnetic nanofluid.

  8. Iron oxide nanoparticles fabricated by electric explosion of wire: focus on magnetic nanofluids

    Directory of Open Access Journals (Sweden)

    I. V. Beketov

    2012-06-01

    Full Text Available Nanoparticles of iron oxides (MNPs were prepared using the electric explosion of wire technique (EEW. The main focus was on the fabrication of de-aggregated spherical nanoparticles with a narrow size distribution. According to XRD the major crystalline phase was magnetite with an average diameter of MNPs, depending on the fraction. Further separation of air-dry EEW nanoparticles was performed in aqueous suspensions. In order to provide the stability of magnetite suspension in water, we found the optimum concentration of the electrostatic stabilizer (sodium citrate and optimum pH level based on zeta-potential measurements. The stable suspensions still contained a substantial fraction of aggregates which were disintegrated by the excessive ultrasound treatment. The separation of the large particles out of the suspension was performed by centrifuging. The structural features, magnetic properties and microwave absorption of MNPs and their aqueous solutions confirm that we were able to obtain an ensemble in which the magnetic contributions come from the spherical MNPs. The particle size distribution in fractionated samples was narrow and they showed a similar behaviour to that expected of the superparamagnetic ensemble. Maximum obtained concentration was as high as 5 % of magnetic material (by weight. Designed assembly of de-aggregated nanoparticles is an example of on-purpose developed magnetic nanofluid.

  9. One-step process for superhydrophobic metallic surfaces by wire electrical discharge machining.

    Science.gov (United States)

    Bae, Won Gyu; Song, Ki Young; Rahmawan, Yudi; Chu, Chong Nam; Kim, Dookon; Chung, Do Kwan; Suh, Kahp Y

    2012-07-25

    We present a direct one-step method to fabricate dual-scale superhydrophobic metallic surfaces using wire electrical discharge machining (WEDM). A dual-scale structure was spontaneously formed by the nature of exfoliation characteristic of Al 7075 alloy surface during WEDM process. A primary microscale sinusoidal pattern was formed via a programmed WEDM process, with the wavelength in the range of 200 to 500 μm. Notably, a secondary roughness in the form of microcraters (average roughness, Ra: 4.16 to 0.41 μm) was generated during the exfoliation process without additional chemical treatment. The low surface energy of Al 7075 alloy (γ = 30.65 mJ/m(2)) together with the presence of dual-scale structures appears to contribute to the observed superhydrophobicity with a static contact angle of 156° and a hysteresis less than 3°. To explain the wetting characteristics on dual-scale structures, we used a simple theoretical model. It was found that Cassie state is likely to present on the secondary roughness in all fabricated surfaces. On the other hand, either Wenzel or Cassie state can present on the primary roughness depending on the characteristic length of sinusoidal pattern. In an optimal condition of the serial cutting steps with applied powers of ∼30 and ∼8 kW, respectively, a stable, superhydrophobic metallic surface was created with a sinusoidal pattern of 500 μm wavelength.

  10. Structure, magnetic and microwave properties of FeNi nanoparticles obtained by electric explosion of wire

    Energy Technology Data Exchange (ETDEWEB)

    Kurlyandskaya, G.V., E-mail: galina@we.lc.ehu.es [University of the Basque Country UPV-EHU, Bilbao (Spain); Ural Federal University, Ekaterinburg (Russian Federation); Madinabeitia, Iñaki, E-mail: melixelbeitia@gmail.com [Ural Federal University, Ekaterinburg (Russian Federation); Beketov, I.V., E-mail: beketov@iep.uran.ru [Ural Federal University, Ekaterinburg (Russian Federation); Institute of Electrophysics, RAS, Urals Branch, Ekaterinburg (Russian Federation); Medvedev, A.I., E-mail: medtom@iep.uran.ru [Ural Federal University, Ekaterinburg (Russian Federation); Institute of Electrophysics, RAS, Urals Branch, Ekaterinburg (Russian Federation); Larrañaga, A., E-mail: aitor.larranaga@ehu.es [University of the Basque Country UPV-EHU, Bilbao (Spain); Safronov, A.P., E-mail: safronov@iep.uran.ru [Ural Federal University, Ekaterinburg (Russian Federation); Institute of Electrophysics, RAS, Urals Branch, Ekaterinburg (Russian Federation); Bhagat, S.M., E-mail: bhagat@umd.edu [University of Maryland, College Park (United States)

    2014-12-05

    Highlights: • We have prepared a new nanomaterial Fe48Ni52 by the EEW technique. • X-ray diffraction, BET, magnetization and microwave absorption were studied. • The electron microscopies showed that the grains are spherical in shape. • The field variation of the microwave loss required a deeper structural investigation. • HRTEM revealed the presence of “twinned” layers inside the grains. - Abstract: Magnetic nanoparticles (MNPs) of FeNi were prepared by the electric explosion of wire aiming to obtain a large batch of magnetic nanomaterial with enhanced effective magnetization. X-ray diffraction, transmission, scanning electron microscopy, low temperature nitrogen adsorption, magnetization and microwave absorption measurements were used for full characterization. The shape of the MNPs with weight averaged mean diameter of 69 ± 8 nm, was very close to being spherical. The saturation magnetization of about 140 emu/g up for 300 K was established. The room temperature microwave signal was very complex due to sizable zero field absorption and various contributions. We obtain reasonable agreement between structural magnetic and microwave techniques by taking into account the presence of so-called “twin” structure in the MNPs.

  11. Size effects in electrical and magnetic properties of quasi-one-dimensional tin wires in asbestos

    Science.gov (United States)

    Chernyaev, A. V.; Shamshur, D. V.; Fokin, A. V.; Kalmykov, A. E.; Kumzerov, Yu. A.; Sorokin, L. M.; Parfen'ev, R. V.; Lashkul, A.

    2016-03-01

    Bulk composites have been prepared based on one-dimensional fibers of natural chrisothil-asbestos with various internal diameters ( d = 6-2.5 nm) filled with tin. The electrical and magnetic properties of quasi-one-dimensional Sn wires have been studied at low temperatures. The electrical properties have been measured at T = 300 K at a pressure P = 10 kbar. It has been found that the superconducting (SC) characteristics of the nanocomposites (critical temperature T c and critical magnetic field H c) increase as the Sn filament diameter decreases. The temperature spreading of the resistive SC transition also increases as the Sn filament diameter decreases, which is explained by the SC order parameter fluctuations. The size effects (the increase in critical temperature T c and transition width Δ T c) in Sn nanofilaments are well described by the independent Aslamazov-Larkin and Langer-Ambegaokara fluctuation theories, which makes it possible to find the dependence of T c of the diffuse SC transition on the nanowire diameter. Using the temperature and magnetic-field dependences of the magnetic moment M( T, H), it has been found that the superconductor-normal metal phase diagram of the Sn-asbestos nanocomposite has a wider region of the SC state in T and H as compared to the data for bulk Sn. The magnetic properties of chrisotil-asbestos fibers unfilled with Sn have been studied. It has been found that the Curie law is fulfilled and that the superparamagnetism is absent in such samples. The obtained results indicate the absence of magnetically ordered impurities (magnetite) in the chrisotil-asbestos matrix, which allowed one to not consider the problem of the interaction of the magnetic subsystem of the asbestos matrix and the superconducting subsystem of Sn nanowires.

  12. Flame spread over electrical wire with AC electric fields: Internal circulation, fuel vapor-jet, spread rate acceleration, and molten insulator dripping

    KAUST Repository

    Lim, Seungjae

    2015-04-01

    The effect of electric field on the characteristics of flame spread along a polyethylene (PE) insulated electrical wire was investigated experimentally by varying the AC frequency and voltage applied to the wire. The results showed that the flame spread rate was accelerated due to the convergence of electric flux near the end of wire, having three distinct regimes depending on applied voltage. In each regime, several subregimes could be identified depending on AC frequency. Flame shape (height and width) and slanted direction of the spreading flame were influenced differently. Fuel-vapor jets were ejected from the molten PE surface even for the baseline case without the application of an electric field; this could be attributed to the bursting of fuel vapor bubbles generated from internal boiling at the molten PE surface. An internal circulation of molten-PE was also observed as a result of non-uniform heating by the spreading flame. In the high voltage regime with a high AC frequency, excessive dripping of molten PE led to flame extinction.

  13. Investigation Into the Effects of Nucleotide Content on the Electrical Characteristics of DNA Plasmid Molecular Wires.

    Science.gov (United States)

    Goshi, Noah; Narenji, Alaleh; Bui, Chris; Mokili, John L; Kassegne, Sam

    2016-09-01

    In this study, we investigate the effect of nucleotide content on the conductivity of plasmid length DNA molecular wires covalently bound to high aspect-ratio gold electrodes. The DNA wires were all between [Formula: see text] in length (>6000bp), and contained either 39%, 53%, or 64% GC base-pairs. We compared the current-voltage (I-V) and frequency-impedance characteristics of the DNA wires with varying GC content, and observed statistically significantly higher conductivity in DNA wires containing higher GC content in both AC and DC measurement methods. Additionally, we noted that the conductivity decreased as a function of time for all DNA wires, with the impedance at 100 Hz nearly doubling over a period of seven days. All readings were taken in humidity and temperature controlled environments on DNA wires suspended above an insulative substrate, thus minimizing the effect of experimental and environmental factors as well as potential for nonlinear alternate DNA confirmations. While other groups have studied the effect of GC content on the conductivity of nanoscale DNA molecules (DNA wires at scales that may be required during the fabrication of DNA-based electronics. Furthermore, our results provide further evidence that many of the charge transfer theories developed from experiments using nanoscale DNA molecules may still be applicable for DNA wires at the micro scale.

  14. Investigation of Effects of Nucleotide Content on Electrical Characteristics of DNA Plasmid Molecular Wires.

    Science.gov (United States)

    Goshi, Noah; Narenji, Alaleh; Bui, Chris; Mokili, John L; Kassegne, Sam

    2016-07-28

    In this study, we investigate the effect of nucleotide content on the conductivity of plasmid length DNA molecular wires covalently bound to high aspect-ratio gold electrodes. The DNA wires were all between 2.20-2.35μm in length (>6000bp), and contained either 39%, 53%, or 64% GC base-pairs. We compared the current-voltage (I-V) and frequency-impedance characteristics of the DNA wires with varying GC content, and observed statistically significantly higher conductivity in DNA wires containing higher GC content in both AC and DC measurement methods. Additionally, we noted that the conductivity decreased as a function of time for all DNA wires, with the impedance at 100Hz nearly doubling over a period of seven days. All readings were taken in humidity and temperature controlled environments on DNA wires suspended above an insulative substrate, thus minimizing the effect of experimental and environmental factors as well as potential for nonlinear alternate DNA confirmations. While other groups have studied the effect of GC content on the conductivity of nano-scale DNA molecules (DNA wires at scales that may be required during the fabrication of DNA-based electronics. Furthermore, our results provide further evidence that many of the charge transfer theories developed from experiments using nano-scale DNA molecules may still be applicable for DNA wires at the micro-scale.

  15. Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity

    Science.gov (United States)

    Chung, Wan-Ho; Hwang, Yeon-Taek; Lee, Seung-Hyun; Kim, Hak-Sung

    2016-05-01

    In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet-visible spectroscopy (UV-vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

  16. Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity.

    Science.gov (United States)

    Chung, Wan-Ho; Hwang, Yeon-Taek; Lee, Seung-Hyun; Kim, Hak-Sung

    2016-05-20

    In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet-visible spectroscopy (UV-vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

  17. Numerical investigation on the growth process and size distribution of nanoparticles obtained through electrical explosion of aluminum wire

    Science.gov (United States)

    Bai, Jun; Shi, Zongqian; Jia, Shenli

    2017-02-01

    Numerical investigations on the formation process and the final size distribution of nanoparticles during electrical explosion of Al wire are carried out. Firstly, the formation of the atomic vapor clusters is investigated. It indicates that the Al wire does not reach its atomization conditions. The size of the atomic vapor clusters is obtained, and it increases with the temperature at explosion. Then the growth process of Al nanoparticles from the formed atomic vapor clusters is modeled and the size distribution is predicted. The size distribution at different temperatures indicates that the growth process of Al nanoparticles becomes inactive gradually as the temperature decreases. The investigation of the size distribution under different cooling rates indicates that the bigger cooling rate is favorable for the formation of Al nanoparticles with smaller size dispersion and lower average dimension. The size distribution of Al nanoparticles obtained by the model is qualitatively consistent with the experimental data, which demonstrates the feasibility of this model.

  18. Twin-Axial Wire Antenna

    Science.gov (United States)

    2015-08-06

    COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...by mutual capacitance between the elements. Reactive loads are positioned in said HF/VHF element at regular intervals for optimizing performance of...capacitance between the elements. Reactive loads are positioned in said HF/VHF element at regular intervals for optimizing performance of the antenna in

  19. Energy-loss rate of hot electrons due to confined acoustic phonon modes in a semiconductor quantum wire under transverse electric field

    Science.gov (United States)

    Stepanyan, A.; Yeranosyan, M.; Vardanyan, L.; Asatryan, A.; Kirakosyan, A.; Vartanian, A.

    2017-08-01

    The hot-electron energy-loss rate via the acoustic-phonons in an embedded semiconductor quantum wire of circular cross section in the presence of external electric field has been investigated using deformation potential theory. Dimensional confinement effect on modifying acoustic-phonon modes are taken into account. The energy-loss rate as a function of electric field strength, electron density and electron temperature is obtained. Our calculations show that the electric field applied perpendicularly to the wire axis can be used as an important tool for the control of the energy-loss processes in nanowires.

  20. Effect of Ag in structural, electrical and magnetic properties of Ag-sheated Bi-2223 wires

    Directory of Open Access Journals (Sweden)

    D Sohrabi

    2009-08-01

    Full Text Available  In this study, the superconducting properties of Bi-2223/Ag wires, made by the PIT method have been studied. Powder samples were prepared using conventional solid state reaction method. After calcination, samples with different Ag percent (0, 5, 10, 15, 20, and 25 prepared and sintered at 830 °C. It was shown that Ag addition has not only affected the formation of the desired Bi-2223 phase and the microstructure of these wires, but also influenced on the critical current density (JC and critical temperature.

  1. Time response of electrical conduction block in novel cardiomyocyte wire by extra-cellular photosensitization reaction at various irradiances

    Science.gov (United States)

    Kurotsu, Mariko; Ogawa, Emiyu; Arai, Tsunenori

    2015-03-01

    We studied time response of electrical conduction (EC) block in a novel cardiomyocyte wire by extra-cellular photosensitization reaction (EPR) at various irradiances. This EC block using the EPR has been studied to develop a non-thermal arrhythmia therapeutic methodology. Despite the EC block in acute phase is needed to judge therapeutic endpoint in clinical arrhythmia therapy, time response of the EC block by the EPR in acute phase hasn't been studied. We measured the time to EC block occurrence by the EPR with intra-cellular Ca2+ concentration change using Fluo-4 AM fluorescence measurement by a confocal laser microscope system. The pattern cultivation cover glass with 10 mm Φ which had 60 μm width cultivation areas with 300 μm separations was used to form the cardiomyocyte wires. Rat cardiomyocyte with 10.8×105 cells was disseminated to the cover glasses installed in a 35 mmΦ dish. After 3 days from the dissemination, the EPR was operated to the cardiomyocyte wires for 10 min varying 3-120 mW/cm2 in 663 nm laser irradiances with 20 μg/ml talaporfin sodium. An irradiation area was approximately 60×340 μm2 on each wires. Cross correlation functions (CCF) in measured fluorescence images in every 10 s were calculated across the irradiation area. The time to EC block occurrence was defined as the time of the max difference between adjacent CCFs. By decreasing irradiances in 30-6 mW/cm2, the time to EC block occurrence became longer from 294 to 434 s. In 30-120 mW/cm2, the time to EC block occurrence was nearly constant in 300 s.

  2. Electrically active, doped monocrystalline silicon nanoparticles produced by hot wire thermal catalytic pyrolysis

    CSIR Research Space (South Africa)

    Scriba, MR

    2011-05-01

    Full Text Available Doped silicon nanoparticles have successfully been produced by hot wire thermal catalytic pyrolysis at 40 mbar and a filament temperature of 1800 °C, using a mixture of silane and diborane or phosphine. All particles are monocrystalline with shapes...

  3. Effects of distance between tungsten wire and glass substrate on particle size and photochromic characteristic of tungsten oxide prepared by electric current heating method

    Energy Technology Data Exchange (ETDEWEB)

    Hagizawa, T; Honma, T; Kuroki, Y; Okamoto, T; Takata, M, E-mail: takata@vos.nagaokaut.ac.jp [Department of Electrical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2011-10-29

    Tungsten oxide films consisting of particles were prepared on the substrates placed at various distances from the tungsten wires heated by electric current. The shapes of the particles were sphere in an area on the substrate just above the wire while octahedral shape was found in other area. For the spherical particles, with increasing the distance, the mean particle diameter increased, reached its maximum value and gradually decreased. The particles in each area showed the photochromism especially in near-infrared region. The spherical particles with the smallest size exhibited a significant photochromic effect which could be controlled by changing the distance between the wire and the substrate.

  4. Grain Refinement and High-Performance of Equal-Channel Angular Pressed Cu-Mg Alloy for Electrical Contact Wire

    Directory of Open Access Journals (Sweden)

    Aibin Ma

    2014-12-01

    Full Text Available Multi-pass equal-channel angular pressing (EACP was applied to produce ultrafine-grained (UFG Cu-0.2wt%Mg alloy contact wire with high mechanical/electric performance, aim to overcome the catenary barrier of high-speed trains by maximizing the tension and improving the power delivery. Microstructure evolution and overall properties of the Cu-Mg alloy after different severe-plastic-deformation (SPD routes were investigated by microscopic observation, tensile and electric tests. The results show that the Cu-Mg alloy after multi-pass ECAP at 473 K obtains ultrafine grains, higher strength and desired conductivity. More passes of ECAP leads to finer grains and higher strength, but increasing ECAP temperature significantly lower the strength increment of the UFG alloy. Grain refinement via continuous SPD processing can endow the Cu-Mg alloy superior strength and good conductivity characteristics, which are advantageous to high-speed electrification railway systems.

  5. Water Desalination with Wires

    NARCIS (Netherlands)

    Porada, S.; Sales, B.B.; Hamelers, H.V.M.; Biesheuvel, P.M.

    2012-01-01

    We show the significant potential of water desalination using a novel capacitive wire-based technology in which anode/cathode wire pairs are constructed from coating a thin porous carbon electrode layer on top of electrically conducting rods (or wires). By alternately dipping an array of electrode

  6. Quantum theory of the effect of grain boundaries on the electrical conductivity of thin films and wires

    Science.gov (United States)

    Moraga, Luis; Henriquez, Ricardo; Solis, Basilio

    2015-08-01

    We calculate the electrical conductivity of a metallic sample under the effects of distributed impurities and a random distribution of grain boundaries by means of a quantum mechanical procedure based on Kubo formula. Grain boundaries are represented either by a one-dimensional regular array of Dirac delta potentials (Mayadas and Shatzkes model) or by its three-dimensional extension (Szczyrbowski and Schmalzbauer model). We give formulas expressing the conductivity of bulk samples, thin films and thin wires of rectangular cross-sections in the case when the samples are bounded by perfectly flat surfaces. We find that, even in the absence of surface roughness, the conductivity in thin samples is reduced from its bulk value. If there are too many grain boundaries per unit length, or their scattering strength is high enough, there is a critical value Rc of the reflectivity R of an individual boundary such that the electrical conductivity vanishes for R >Rc. Also, the conductivity of thin wires shows a stepwise dependence on R. The effect of weak random variations in the strength or separation of the grain boundaries is computed by means of the method of correlation length. Finally, the resistivity of nanometric polycrystalline tungsten films reported in Choi et al. J. Appl. Phys. (2014) 115 104308 is tentatively analyzed by means of the present formalism.

  7. Heat Transfer From Electrically Heated Nichrome Wires to Boiling Water at Different Pressures

    Directory of Open Access Journals (Sweden)

    Devi Dayal

    1968-01-01

    Full Text Available Boiling curves for nucleate and film boiling have been drawn for nichrome of three sizes in distilled and degasified water at saturation temperatures under five different sub-atmospheric vapour pressure. It has been observed that (i for the same Q/A (heat transfer, Delta Theta (excess of wire temperature over saturation point of water decreases with pressure in both nucleate and film boiling ranges, (ii Both Q/A max. and Delta Theta/SubC show a rapid decrease with pressure but these variations become more gradual at higher pressures, and (iii Q/A max. and Delta Theta/SubC increase with wire size at all pressures; increase in Delta Theta/SubC however, becomes less conspicuous at higher pressures approaching one atmosphere.

  8. Conjoined Twins

    Science.gov (United States)

    ... sites of conjoined twins. Abdomen. Omphalopagus (om-fuh-LOP-uh-gus) twins are joined near the bellybutton. ... brain tissue. Head and chest. Cephalopagus (sef-uh-LOP-uh-gus) twins are joined at the face ...

  9. Generation of ultra-fast cumulative water jets by sub-microsecond underwater electrical explosion of conical wire arrays

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, D.; Gurovich, V. Tz.; Gleizer, S.; Gruzinsky, K.; Krasik, Ya. E. [Physics Department, Technion, Haifa 32000 (Israel)

    2015-12-15

    The results of experiments with underwater electrical explosion of modified conical arrays of copper and aluminum wires are presented. A pulsed generator producing a 550 kA-amplitude current with a 400 ns rise time was used in the explosion of the arrays. The array explosion generates water flows converging at the axis of the cone. This flow generates a fast-moving water jet with a velocity exceeding 1.8 × 10{sup 5 }cm/s, which was observed being ejected from the surface of the water covering the array. The positions of the water jet were measured by multiple-exposure fast framing imaging. In experiments, the apex angle of the array, the thickness of the water layer above the arrays, or the material of the wires was altered, which changed the resulting velocities and shapes of the emitted jets. A model that considers the converging stationary flow of a slightly compressible fluid is suggested. The velocities and shapes of the jets obtained by this model agree well with the experimentally measured jet velocities.

  10. Modeling and optimization of process variables of wire-cut electric discharge machining of super alloy Udimet-L605

    Directory of Open Access Journals (Sweden)

    Somvir Singh Nain

    2017-02-01

    Full Text Available This paper presents the behavior of Udimet-L605 after wire electric discharge machining and evaluating the WEDM process using sophisticated machine learning approaches. The experimental work is depicted on the basis of Taguchi orthogonal L27 array, considering six input variables and three interactions. Three models such as support vector machine algorithms based on PUK kernel, non-linear regression and multi-linear regression have been proposed to examine the variance between experimental and predicted outcome and preferred the preeminent model based on its evaluation parameters performance and graph analysis. The grey relational analysis is the relevant approach to obtain the best grouping of input variables for maximum material removal rate and minimum surface roughness. Based on statistical analysis, it has been concluded that pulse-on time, interaction between pulse-on time x pulse-off time, spark-gap voltage and wire tension are the momentous variable for surface roughness while the pulse-on time, spark-gap voltage and pulse-off time are the momentous variables for material removal rate. The micro structural and compositional changes on the surface of work material were examined by means of SEM and EDX analysis. The thickness of the white layer and the recast layer formation increases with increases in the pulse-on time duration.

  11. Analysis of electrical explosion of wire systems for the production of nanopowder

    Indian Academy of Sciences (India)

    Rashmita Das; Basanta Kumar Das; Rohit Shukla; T Prabaharan; Anurag Shyam

    2012-10-01

    Nanoscience and nanotechnology continue to grow as fields of scientific research and commercial development as many fundamental properties are size dependent on the nano scale. There are so many techniques for the production and characterization of various ultra fine powders. To gain a fundamental understanding of size dependant properties of matter in the nanometer size regimes and to developnanoscale materials into useful devices to benefit society requires detailed study of the experimental methods, better methods of sample preparation of mono dispersed material in large quantities, and development of nanoparticles characterization methods. Exploding wire method is one such method for the production of metal and metal oxide nanoparticles capable of producing bulk amount of metal nanoparticles at low cost. With the intention of developing better exploding wire system for the production of nanoparticle and to understand the nanoparticle formation process, we have developed two systems in the way of optimization of the experimental set-up for final production of nanoparticles. The detail analysis of the systems and its effect on the nanoparticles has been described in the paper.

  12. Study on mild and severe wear of 7075 aluminum alloys by high-speed wire electrical discharge machining

    Science.gov (United States)

    Xu, Jinkai; Qiu, Rongxian; Xia, Kui; Wang, Zhichao; Xu, Lining; Yu, Huadong

    2017-01-01

    The recast and the carbon layers were fabricated on 7075Al alloys surface by the high-speed wire electrical discharge machining (HS-WEDM) technologyunder various working parameters. The mechanical properties and friction behaviors of the layers were investigated by UMT. 7075 Al alloys were used to do dry sliding wear tests on a pin-ondisk wear tester at room temperature under various contact pressures. 7075 Al alloys had almost the same wear regularity as a function of sliding velocity and rated frequency. The hardness of recast layer was improved. And this method can enhance durability of 7075 Al alloy effectively.The transition to severe wear occurred at a higher load (12N) for asmachined samples, compared with 7075 matrix (9N), the as-machined samples exhibited lower wear rates within the tested loading range.

  13. Analysis of axially symmetric wire antennas by the use of exact kernel of electric field integral equation

    Directory of Open Access Journals (Sweden)

    Krneta Aleksandra J.

    2016-01-01

    Full Text Available The paper presents a new method for the analysis of wire antennas with axial symmetry. Truncated cones have been applied to precisely model antenna geometry, while the exact kernel of the electric field integral equation has been used for computation. Accuracy and efficiency of the method has been further increased by the use of higher order basis functions for current expansion, and by selecting integration methods based on singularity cancelation techniques for the calculation of potential and impedance integrals. The method has been applied to the analysis of a typical dipole antenna, thick dipole antenna and a coaxial line. The obtained results verify the high accuracy of the method. [Projekat Ministarstva nauke Republike Srbije, br. TR-32005

  14. Thermo-Electrical Mathematical Model for Prediction of Ni-Cr Hot-Wire Temperature in Free Air and Inside Small Circular Cavities

    DEFF Research Database (Denmark)

    Petkov, Kiril; Hattel, Jesper Henri

    2017-01-01

    is a semicoupled solution of the heat conduction equation and the electrical diffusion equation in a one-dimensional (1-D) control volume finite-difference framework. A study on the available natural convection correlations for thin metal wires for Rayleigh numbers in the range of 10-3-101 is carried out in order...

  15. Spin–orbit interaction effect on the linear and nonlinear properties of quantum wire in the presence of electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lahon, Siddhartha [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Department of Physics, Kirori Mal College, University of Delhi, Delhi 110007 (India); Kumar, Manoj, E-mail: manojmalikdu@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Jha, Pradip Kumar [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Department of Physics, DDU College, University of Delhi, Delhi 110007 (India); Mohan, Man [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2013-12-15

    Here we have investigated the influence of external electric field and magnetic field on the optical absorption and refractive index changes of a parabolically confinement wire in the presence of Rashba spin orbit interaction. We have used density matrix formulation for obtaining optical properties within the effective mass approximation. The results are presented as a function of quantum wire radius, electric field, magnetic field, Rashba spin orbit interaction strength and photon energy. Our results indicate an increase of electric field redshifts the peak positions of absorption coefficient and refractive index changes. The role of confinement strength and spin orbit interaction strength as control parameters on the linear and nonlinear properties have been demonstrated. -- Highlights: • We study nonlinear properties in a quantum wire. • We have solved the effect of external electric and magnetic field with Rashba spin orbit interaction on linear and nonlinear properties in quantum wire. • We have used density matrix theory approach. • We find that the absorption coefficients and changes in refractive index are shifted.

  16. ACARDIAC TWIN

    OpenAIRE

    Vinayachandran; Jyothi,; Bindu; Umadevi

    2014-01-01

    Acardiac twin is a very rare complication occurring in monozygotic twins in which one fetus develops normally (pump twin) and the other (recipient twin) demonstrate cardiac non development and othe r anomalies. This may represent an extreme form of TTTS, also referred to as TRAP sequence. 1,2,

  17. Biomechanical difference between Twin-Block appliance and straight wire appliance in the early treatment of Class II division 1 malocclusion%Twin-Block与直丝弓矫治器早期矫治骨性安氏Ⅱ类1分类错牙合:生物力学差异

    Institute of Scientific and Technical Information of China (English)

    晋朝晖; 刘文慧

    2015-01-01

    BACKGROUND:Class II malocclusion is commonly observed in clinics, with the main manifestation of skeletal malocclusion, and mandibular retrusion is the main reason. Class II malocclusion should be treated early to correct skeletal malformation and improve facial appearance. OBJECTIVE:To compare the biomechanics change in early treatment of Class II division 1 malocclusion with Twin-Block appliance and straight wire appliance combined with face-bow and Class II drawing. METHODS: Thirty patients with malocclusion who were at peak velocity on the growth curve were randomly divided into two groups, with 15 cases in each group. Patients in each group were treated with Twin-Block appliance and straight wire appliance combined face-bow and Class II drawing, respectively. The cephalometric records of al patients were examined before and after the treatments. The acquired data were processed by statistical analysis. RESULTS AND CONCLUSION:After treatment, al molars and cuspid teeth achieved or reached Class I, and ANB angle decreased to normal range. The bone effect of Twin-Block appliance was more significant than straight wire appliance. Using Twin-Block appliance, the length of mandible body and lower face height increased significantly. Experimental findings indicate that, Twin-Block appliance has significant therapeutic effects in treatment of early skeletal Class II division 1 malocclusion patients, who are at peak velocity on the growth curve. With the biomechanical effects, this treatment corrects asymmetrical jaw relation, reconstructs the tissue, and obtains satisfactory lateral facial profile of soft tissues. The therapeutic effect is more obvious for patients with obvious mandibular retrusion, flared upper incisors and upright lower incisors.%背景:安氏Ⅱ类错牙合是临床上常见的错牙合畸形,主要表现为骨性错牙合,其主要因素是下颌后缩,对于此类患者,多进行早期矫治,以纠正骨性畸形,明显改善

  18. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  19. Using the Zero-Resistance Spark Circuit on the Wire Cut Electric Discharge Machine to Realize Energy Savings

    Directory of Open Access Journals (Sweden)

    Shao-Hsien Chen

    2014-08-01

    Full Text Available There is an increasing emphasis on the development green manufacturing technologies. To improve processing and energy efficiency of modern Wire Cut Electric Discharge Machines (WEDM, many studies have focused on the design of the device’s discharge circuit. Currently, most such circuits use a resistor to impose current-limitations. When current flows through this resistor, considerable electrical energy converted into heat. The generated heat increases the temperature in the discharge circuit, which negatively impacts processing and energy efficiency, even though the temperature rise could be controlled by arranging cooling devices around the discharge circuit. This study seeks to produce an improved discharge circuit for use in WEDMs. We use DC-DC and electronic voltage regulation technology to convert the energy originally dissipated in the resistor directly into the energy for use in machining. The Zero-Resistance Spark Circuit is the critical design to realize the energy saving effect. Experimental results indicate energy savings of 10 to 15%.

  20. Wiring through tunneling nanotubes--from electrical signals to organelle transfer.

    Science.gov (United States)

    Abounit, Saïda; Zurzolo, Chiara

    2012-03-01

    Tunneling nanotubes (TNTs) represent a subset of F-actin-based transient tubular connections that allow direct communication between distant cells. Recent studies have provided new insights into the existence of TNTs in vivo, and this novel mechanism of intercellular communication is implicated in various essential processes, such as development, immunity, tissue regeneration and transmission of electrical signals. TNTs are versatile structures known to facilitate the transfer of various cargos, such as organelles, plasma membrane components, pathogens and Ca(2+). Recently, a new function of TNTs in the long-range transfer of electrical signals that involves gap junctions has been suggested. This indicates that different types of TNTs might exist, and supports the notion that TNTs might not be just passive open conduits but rather are regulated by gating mechanisms. Furthermore, TNTs have been found in different cell lines and are characterized by their diversity in terms of morphology. Here we discuss these novel findings in the context of the two models that have been proposed for TNT formation, and focus on putative proteins that could represent TNT specific markers. We also shed some light on the molecular mechanisms used by TNTs to transfer cargos, as well as chemical and electrical signals.

  1. Spectroscopy of a plasma formed in the vicinity of implosion of the shock wave generated by underwater electrical explosion of spherical wire array

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, O.; Efimov, S.; Gurovich, V. Tz.; Krasik, Ya. E. [Physics Department, Technion, Haifa 32000 (Israel); Bernshtam, V. [Weizmann Institute of Science, Rehovot 76100 (Israel)

    2015-05-15

    The results of visible spectroscopy of the plasma formed inside a copper capillary placed at the equatorial plane of an underwater electrically exploded spherical wire array (30 mm in diameter; 40 wires, each of 100 μm in diameter) are reported. In the experiments, a pulsed power generator with current amplitude of ∼300 kA and rise time of ∼1.1 μs was used to produce wire array explosion accompanied by the formation of a converging strong shock wave. The data obtained support the assumption of uniformity of the shock wave along the main path of its convergence. The spectroscopic measurements show that this rather simple method of formation of a converging strong shock wave can be used successfully for studying the shock wave's interaction with matter and the evaporation processes of atoms from a target.

  2. Stress serration and arch-shaped Lüders stress plateau behaviour of Ti-50.8 at% Ni wire prepared by selective electrical resistance over-aging

    Science.gov (United States)

    Meng, Qinglin; Wu, Zhigang; Bakhtiari, Reza; Zhang, Junsong; Yang, Hong; Liu, Yinong

    2016-11-01

    Joule heating of NiTi shape memory alloy wires is a commonly applied technique for heat treatment and shape setting in many applications. Another innovative use of this method is to produce functionally graded NiTi. In this study, NiTi wires with spatially varied shape memory characteristics along the length were created by electrical resistance over-aging of a Ni-rich superelastic NiTi alloy. The stress-strain behaviour of such wires exhibited some new and unique characteristics during the stress-induced martensitic transformation, including two discrete stress plateaus, stress serration during transition between the two stress plateaus and an arch-shaped stress plateau in the over-aged section. These unique features have direct implications to design using NiTi alloys and the underlying mechanisms are explained in this study.

  3. Exp erimental investigation on the electrical explosion of single aluminum wire in vacuum%真空中铝单丝电爆炸的实验研究∗

    Institute of Scientific and Technical Information of China (English)

    王坤; 史宗谦; 石元杰; 白骏; 李阳; 武子骞; 邱爱慈; 贾申利

    2016-01-01

    The electrical explosion of single wire occurs in many application fields, such as wire-array Z-pinch, synthesis of the nanopowder, high-intensity magnetic field source, etc. The initial stage of the electrical explosion of single wire has a critical influence on the stagnation and X-ray yield in the wire-array Z-pinch. The impressive result of X-ray yield from wire-array Z-pinch is a major motivation to promote the research in this field. Although numerous studies have been carried out to gain a deep insight into the physics of the electrical explosion of single wire, more experimental investigations are necessary to optimize the energy deposition and expansion rate. It is important to investigate the characteristics of the electrical explosion of single wire under the negative polarity pulsed-current, which is adopted in many Z-pinch facilities. In this paper, the electrical explosion of aluminum wire under negative polarity pulsed-current in vacuum is investigated. In the present experiments, the light emission is measured by the photomultiplier and streak camera. A laser probe EKSPLA-PL2251C (30 ps, 532 nm) is adopted to perform the shadowgraphy, schlieren and interferometry diagnostics. The radial knife-edge schlieren scheme is employed to translate the regions with plasma refractivity and gas-type refractivity. The interferometry is constructed based on Mach-Zehnder interferometer. The shadowgram, schlieren image and interferogram are recorded by Canon cameras. The typical waveforms of the voltage, current and light emission from the electrical explosion of 15 µm-diameter, 2 cm-long aluminum wire are derived. The energy deposition at the instant of voltage collapse is about 2.4 eV/atom (vaporization energy is about 4 eV/atom). In order to increase the energy deposited into the wire, the 15 µm-diameter, 2 cm-long aluminum wire with 2 µm polyimide coating is exploded with the same electrical parameters. The energy deposition in the coated wire is about 5 e

  4. Development of TiO2 electrical insulation coating on Ag-alloy sheathed Bi2Sr2CaCu2O8-x round-wire

    Science.gov (United States)

    Kandel, H.; Lu, J.; Jiang, J.; Chen, P.; Matras, M.; Craig, N.; Trociewitz, U. P.; Hellstrom, E. E.; Larbalestier, D. C.

    2015-03-01

    We have developed TiO2 coating on Ag-alloy sheathed Bi2Sr2CaCu2O8-x (Bi-2212) round-wire conductor for electrical insulation in Bi-2212 magnets. The green coating has a base layer comprised of TiO2, polyvinyl butyral (PVB) and a small amount of polysilicate and a top layer made of polyacrylic. The coating was applied on the conductor using a continuous reel-to-reel dip coating process and showed very good adherence and flexibility that is suitable for magnet coil winding. The thickness of the coating is a function of slurry viscosity, wire withdrawal speed and wire radius. Small test coils were built with the coated Bi-2212 round-wires and were heat treated at 100 atm pressure. During the heat treatment, the PVB and polyacrylic were removed from the green coating and the polysilicate decomposed to SiO2 that served as a sintering aid for TiO2. After the heat treatment, the coating remained strongly adhered to the conductor and did not have a detrimental effect on the critical current (Ic) values. The breakdown voltage was about 150 V across a 7 μm thick heat treated coating on Bi-22112 round-wire conductor, corresponding to a dc dielectric strength of about 21 MV m-1.

  5. Twin births

    DEFF Research Database (Denmark)

    Hoffmann, Elise; Oldenburg, Anna; Rode, Line;

    2012-01-01

    To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery.......To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery....

  6. Effect of synthetic temperature on the dispersion stability of gold nanocolloid produced via electrical explosion of wire.

    Science.gov (United States)

    Yun, G S; Bac, L H; Kim, J S; Kwon, Y S; Choi, H S; Kim, J C

    2011-07-01

    In this study, gold nanocolloid was produced via the electrical explosion of wire in water, for the purpose of medical treatment. Thus, the use of other additives was avoided to stabilize the gold nanocolloid. The temperature of the water that was to be used for explosion was changed, and its effect on the stability of the gold nanocolloid was investigated. The synthetic temperature was varied from ice temperature to 80 degrees C. The morphology and particle size were studied using a transmission electron microscope. The UV-Vis spectra confirmed the formation of gold nanoparticles in the water. The stability of the gold nanocolloid was estimated using the zeta-potential and Turbiscan methods. The results showed that the synthetic temperature affected the stability of the gold nanocolloid. The TEM images of the gold nanoparticles prepared at low temperatures (0 and 20 degrees C) have several big particles. But, when the synthetic temperature was increased to 80 degrees C, most of the nanoparticles formed a spherical shape, without neck connection. Better stability was obtained in the gold nanocolloid sample prepared at a higher temperature. The gold nanocolloid that was synthesized at 80 degrees C was stable for more than three months, with small sedimentation.

  7. Micro-CT evaluation of in vivo osteogenesis at implants processed by wire-type electric discharge machining.

    Science.gov (United States)

    Yamaki, Koichi; Kataoka, Yu; Ohtsuka, Fukunaga; Miyazaki, Takashi

    2012-01-01

    Titanium surfaces processed by wire-type electric discharge machining (EDM) are microfabricated surfaces with an irregular morphology, and they exhibited excellent in vitro bone biocompatibility. In this study, the efficiency of in vivo osteogenesis on EDM surfaces was investigated by surgically placing screw-shaped EDM-processed and machined-surface implants into the femurs of four Japanese white rabbits. The volume and process of new bone formation were evaluated by an X-ray micro-CT scanner, coupled with histopathological observations at 1, 2, and 4 weeks post-implantation. Before surgical implantation, the surface topography and contact angle of each implant surface were examined. Bone formation increased over time on both implant surfaces, with both implant types yielding statistically equivalent bone volume at 4 weeks post-implementation. However, at 1 week post-implantation, amount of new bone at EDM-processed implant was markedly greater than that at machined-surface implant. Moreover, new bone appeared to initiate directly from the EDM surfaces, while new bone appeared to generate from pre-existing host bone to the machined surfaces. Thus, EDM seemed to be a promising method for surface modification of titanium implants to support enhanced osteogenesis.

  8. Signal Analysis and Waveform Reconstruction of Shock Waves Generated by Underwater Electrical Wire Explosions with Piezoelectric Pressure Probes.

    Science.gov (United States)

    Zhou, Haibin; Zhang, Yongmin; Han, Ruoyu; Jing, Yan; Wu, Jiawei; Liu, Qiaojue; Ding, Weidong; Qiu, Aici

    2016-04-22

    Underwater shock waves (SWs) generated by underwater electrical wire explosions (UEWEs) have been widely studied and applied. Precise measurement of this kind of SWs is important, but very difficult to accomplish due to their high peak pressure, steep rising edge and very short pulse width (on the order of tens of μs). This paper aims to analyze the signals obtained by two kinds of commercial piezoelectric pressure probes, and reconstruct the correct pressure waveform from the distorted one measured by the pressure probes. It is found that both PCB138 and Müller-plate probes can be used to measure the relative SW pressure value because of their good uniformities and linearities, but none of them can obtain precise SW waveforms. In order to approach to the real SW signal better, we propose a new multi-exponential pressure waveform model, which has considered the faster pressure decay at the early stage and the slower pressure decay in longer times. Based on this model and the energy conservation law, the pressure waveform obtained by the PCB138 probe has been reconstructed, and the reconstruction accuracy has been verified by the signals obtained by the Müller-plate probe. Reconstruction results show that the measured SW peak pressures are smaller than the real signal. The waveform reconstruction method is both reasonable and reliable.

  9. Relative Genetic and Environmental Contributions to Variations in Human Retinal Electrical Responses Quantified in a Twin Study.

    Science.gov (United States)

    Bhatti, Taha; Tariq, Ambreen; Shen, Ting; Williams, Katie M; Hammond, Christopher J; Mahroo, Omar A

    2017-08-01

    To estimate heritability of parameters of human retinal electrophysiology and to explore which parameters change with age. Prospective, classic twin study. Adult monozygotic and dizygotic twin pairs recruited from the TwinsUK cohort. Electroretinogram responses were recorded using conductive fiber electrodes in response to stimuli incorporating standards set by the International Society for the Clinical Electrophysiology of Vision. These parameters were extracted; in addition, photopic negative-response (PhNR; originating from retinal ganglion cells) and i-wave components were extracted from responses to the photopic single flash. Parameter values were averaged from both eyes. Mean values were calculated for the cohort. Correlation coefficients with age were calculated (averaging parameters from both twins from each pair). Coefficients of intrapair correlation were calculated for monozygotic and dizygotic twins. Age-adjusted heritability estimates were derived using standard maximum likelihood structural equation twin modeling. Responses were recorded from 210 participants in total (59 monozygotic and 46 dizygotic twin pairs). Ninety-three percent were women. Mean age for the cohort was 62.4 years (standard deviation, 11.4 years). In general, response amplitudes correlated negatively, and implicit times positively, with age. Correlations were statistically significant (P 0.35) for the following parameters: scotopic standard and bright-flash a-wave implicit times, photopic 30-Hz flicker and single-flash b-wave implicit times, and PhNR and i-wave implicit times. Intrapair correlations were higher for monozygotic than dizygotic twins, suggesting important genetic influences. Age-adjusted estimates of heritability were significant for all parameters (except scotopic dim-flash b-wave implicit time), ranging from 0.34 to 0.85. Highest estimates were for photopic single-flash a-wave and b-wave amplitudes (0.84 and 0.85, respectively). This study explored heritability of

  10. 电火花线切割机床加工工艺参数的研究%Research on Wire Electrical Discharge Machining Processing Technology Parameters

    Institute of Scientific and Technical Information of China (English)

    杨亚琴

    2012-01-01

    This paper describes the processing mechanism of wire electrical discharge machining, by using orthogonal test, makes optimization design of peak current, pulse width, and intrapulse ratio of wire electrical discharge machining with high cutting rate and low wire wear, reduce the experiment times, shorten the cycle and improve the efficiency and benefit, so as to optimize processing technology parameter, improve the product quality- It concluded the relation of electric parameters and the processing speed, and surface roughness, for providing the basis for further studying on the processing law of wire electrical discharge machining.%本文阐述了电火花线切割机床的加工机理,利用正交试验的方法,对高速走丝电火花线切割机床加工中的峰值电流、脉冲宽度、脉间比等工艺条件进行了试验的优化设计,减少了试验的次数,缩短了实验周期,提高了效率和效益;从而优化了电火花线切割机床加工工艺参数,提高了加工件的质量;得出了电参数与加工速度和表面粗糙度之间的联系,为进一步研究电火花线切割加工工艺规律提供了基础.

  11. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  12. Structural, optical and electrical properties of ZnO/Zn 2GeO 4 porous-like thin film and wires

    Science.gov (United States)

    Jumidali, Mohd Muzafa; Sulieman, Kamal Mahir; Hashim, Md Roslan

    2011-03-01

    Zinc oxide/zinc germanium oxide (ZnO/Zn 2GeO 4) porous-like thin film and wires has been fabricated by simple thermal evaporation method at temperature about 1120 °C for 2.5 h. The structural and optical properties of the porous-like-thin film and wires have been investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. Metal semiconductor metal (MSM) photodetector structure was used to evaluate the electrical characteristics by using current-voltage ( I- V) measurements. Room temperature photoluminescence spectrum of the sample shows one prominent ultraviolet peak at 378 nm and a shoulder at 370 nm. In addition, broad visible blue emission peak at wavelength 480 nm and green emission peak at 500 nm are also observed. Strong photoelectric properties of the MSM in the UV demonstrated that the porous-like-thin film and wires contribute to its photosensitivity and therefore making ZnO/Zn 2GeO 4 wires potential photodetector in the shorter wavelength applications.

  13. Structure, magnetic and microwave properties of FeNi invar nanoparticles obtained by electrical explosion of wire in different preparation conditions

    Science.gov (United States)

    Kurlyandskaya, G. V.; Bhagat, S. M.; Bagazeev, A. V.; Medvedev, A. I.; Ballesteros, A.; Beketov, I. V.; Safronov, A. P.

    2016-11-01

    Magnetic nanoparticles (MNPs) of close to invar (Fe0.635Ni0.365) composition were prepared by the electrical explosion of wire using different conditions to insure different values of overheating rates. X-ray diffraction, transmission electron microscopy, low temperature nitrogen adsorption, magnetic and microwave measurements were used for the characterization of MNPs. Increase of the energy injected into the wire led to increase of the specific surface (Ssp) of the produced MNPs from 4.6 to 13.5 m2/g. The fabricated MNPs were spherical and weakly aggregated with the average weighted diameter in the range of 54-160 nm depending on the Ssp. The phase composition of FeNi MNPs consists of two solid solutions of Ni in α-phase and γ-phase lattices. The increase of the energy injected into the wire leads to increase of the α-phase from 5 to 10 wt% as the injected energy raised from 0.8 to 2.5 times the sublimation energies of the wire material. Comparative analysis of structure magnetic and microwave properties showed that the obtained MNPs are important magnetic materials with high saturation magnetization and significant zero field microwave absorption which can be expected to lead to important technological applications.

  14. Parametric Optimization of Wire Electrical Discharge Machining of Powder Metallurgical Cold Worked Tool Steel using Taguchi Method

    Science.gov (United States)

    Sudhakara, Dara; Prasanthi, Guvvala

    2016-08-01

    Wire Cut EDM is an unconventional machining process used to build components of complex shape. The current work mainly deals with optimization of surface roughness while machining P/M CW TOOL STEEL by Wire cut EDM using Taguchi method. The process parameters of the Wire Cut EDM is ON, OFF, IP, SV, WT, and WP. L27 OA is used for to design of the experiments for conducting experimentation. In order to find out the effecting parameters on the surface roughness, ANOVA analysis is engaged. The optimum levels for getting minimum surface roughness is ON = 108 µs, OFF = 63 µs, IP = 11 A, SV = 68 V and WT = 8 g.

  15. Heat Transfer in Film Boiling from Electrically Heated Nichrome Wire to Boiling Water at Different Pressure-II

    Directory of Open Access Journals (Sweden)

    Devi Dayal

    1969-01-01

    Full Text Available Values of film thickness in film boiling have been computed for three different sizes of nichrome wires at five different sub-atmospheric pressures. The values of alpha , total heat transmission co-efficient, ac heat transmission co-efficient due to conduction through the vapour film and alpha R, heat transmission co-efficient due to radiation, have been calculated. The values of film thickness were found to decrease with external pressure, but were found to increase slightly with the radius of the wire. alpha & alpha c both increase with rise of pressure but decrease with the radius of the radius of the heated wire. Alpha R shows a minimum value at a pressure of 15 cm. of Hg. in the case of all the wire sizes. The radiation loss alpha R is much smaller than conduction loss alpha. "

  16. Bridge Wire Electric Ignition Drive Circuits Design%桥丝电点火器的驱动电路设计∗

    Institute of Scientific and Technical Information of China (English)

    张宪国; 曹红松; 赵捍东; 白松

    2015-01-01

    Pulse jet engines are often ignited by gunpowder wrapped bridge wire electric igniter and widely used in aircraft attitude control. The electric igniter needs short-pulse current driving for rapid initiation. In this paper,opto-isolated constant current source and capacitor discharge mode driving circuits are designed for the demand of micro-bridge wire electric igniter. Two kinds of detonating circuit designs implemente the ignition driving of brige wire e-lectric igniter wtih resistance fluctuations. The constant current source mode is capable of long storage life,compact spatial structure and high safety, and the reservoir capacitor mode demonstrates high energy efficiency and fast-acting for quick initiation. Two methods provide reference designs for the pulse jet engines of different engineering requirements.%用于飞行器姿态控制的脉喷发动机常采用火药包裹的桥丝电点火器进行点火,电点火器需要短时脉冲电流驱动。本文针对微小型桥丝电点火器驱动需求,设计了光耦隔离恒流源方式及电容储能脉冲放电驱动电路,均实现了对阻值波动桥丝电点火器的点火驱动。试验证明,光耦隔离恒流源方式可靠性高,安全稳定,电容储能放电方式效率高、作用迅速。该两种设计方法可为脉喷发动机的工程实践提供参考。

  17. 双丝间接电弧氩弧焊的熔滴过渡形式%Mode of Metal Transfer on Twin-wire Indirect Arc Argon Welding

    Institute of Scientific and Technical Information of China (English)

    曹梅青; 邹增大; 张顺善; 曲仕尧

    2011-01-01

    采用氙灯背光高速摄像系统及示波器对双丝间接电弧氩气保护焊的熔滴过渡进行了研究。结果表明:双丝间接电弧氩弧焊正、负极的熔滴过渡形式并不完全相同,根据正、负极熔滴过渡形式的不同组合将熔滴过渡分为大滴—大滴过渡,射滴—大滴过渡,短路过渡,射滴—射滴过渡,射流—大滴过渡,射流—射滴过渡及射流过渡7种类型。在焊接过程中以射流过渡及射流—射滴过渡为主。双丝间接电弧氩弧焊主要靠电弧热量及熔滴携带热量熔化母材,熔滴过渡方向与电流流动方向不同,正、负两极熔滴同时过渡,两极的过渡频率、尺寸有所不同。%The metal transfer of twin-wire indirect arc argon welding was investigated with high-speed camcorder system based on a xenon lamp source and digital oscillogragh.Results show that the metal transfer mode of anodal and cathodal does not mean completely th

  18. Hardness and electrical conductivity of alloy wire for track circuit%轨道电路合金导线的硬度及导电性能

    Institute of Scientific and Technical Information of China (English)

    贺帅超; 谭丽

    2016-01-01

    By taking the alloy wire for track circuit with a single addition of Ce , Y and composite addition of Ce +Y as research objects respectively , the influence of alloying elements and heat treatment processes on hardness and electrical conductivity of the Cu -Cr-Zr alloy wire were investigated , and the high temperature softening resistance of the alloy wire was also analyzed .The results show that adding rare earth elements Ce or Y, the hardness of the alloy wire increases by 14-20 HV0.1 after aging, while the electrical conductivity reduces by 2%-4%IACS.The hardness order of the alloy wire aged for the same time from high to low is Cu-Cr-Zr-Ce>Cu-Cr-Zr-Y>Cu-Cr-Zr, while the conductivity order of it from high to low is Cu-Cr-Zr >Cu-Cr-Zr-Ce >Cu-Cr-Zr-Y.The softening temperature of the alloy wire with composite addition of Ce and Y increases by 30 ℃.The precipitation strengthening phase in Cu-Cr-Zr-Ce-Y alloy is mainly CrCu2 ( Zr, Mg) phase.%以单一添加稀土元素Ce、Y和复合添加Ce+Y的Cu-Cr-Zr合金轨道电路导线为研究对象,研究了合金化元素和热处理工艺对Cu-Cr-Zr合金导线的硬度和电导率的影响,并分析了合金导线的抗高温软化性能。结果表明,添加稀土元素Ce、Y的合金导线时效后的硬度提高了14~20 HV0.1,而电导率降低了2~4%IACS;相同时效时间下合金导线硬度从高至低的顺序为Cu-Cr-Zr-Ce>Cu-Cr-Zr-Y>Cu-Cr-Zr,电导率从高至低的顺序为Cu-Cr-Zr>Cu-Cr-Zr-Ce>Cu-Cr-Zr-Y;复合添加Ce+Y合金导线的软化温度提高了约30℃,Cu-Cr-Zr-Ce-Y合金中的时效析出相主要是CrCu2( Zr, Mg)相。

  19. Twin pregnancy

    DEFF Research Database (Denmark)

    Sperling, Lene; Tabor, A

    2001-01-01

    Determination of chorionicity is one of the most important issues in the management of twin pregnancy. Modern ultrasound equipment has made it possible to accurately assess placentation already in the first trimester with the lambda sign. With regard to prenatal diagnosis, it is important to know...... for clinicians caring for twin pregnancies....

  20. Wire Array Photovoltaics

    Science.gov (United States)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  1. Enhanced electrical properties at boundaries including twin boundaries of polycrystalline CdTe thin-film solar cells.

    Science.gov (United States)

    Li, H; Liu, X X; Lin, Y S; Yang, B; Du, Z M

    2015-05-07

    The effect of grain boundaries (GBs), in particular twin boundaries (TBs), on CdTe polycrystalline thin films is studied by conductive atomic force microscopy (C-AFM), electron-beam-induced current (EBIC), scanning Kelvin probe microscopy (SKPM), electron backscatter diffraction (EBSD), and scanning transmission electron microscopy (STEM). Four types of CdTe grains with various densities of {111} Σ3 twin boundaries (TBs) are found in Cl-treated CdTe polycrystalline thin films: (1) grains having multiple {111} Σ3 TBs with a low angle to the film surface; (2) grains having multiple {111} Σ3 TBs parallel to the film surfaces; (3) small grains on a scale of not more than 500 nm, composed of Cd, Cl, Te, and O; and (4) CdTe grains with not more than two {111} Σ3 TBs. Grain boundaries (including TBs) exhibit enhanced current transport phenomena. However, the {111} Σ3 TB is much more beneficial to micro-current transport. The enhanced current transport can be explained by the lower electron potential at GBs (including TBs) than the grain interiors (GIs). Our results open new opportunities for enhancing solar cell performances by controlling the grain boundaries, and in particular TBs.

  2. Optical and Electrical Investigation of ZnO Nano-Wire Array to Micro-Flower from Hierarchical Nano-Rose Structures.

    Science.gov (United States)

    Pal, Kaushik; Zhan, Bihong; Ma, Xiao; Wang, Guoping; Schirhagl, Romana; Murgasen, Priya

    2016-01-01

    We have demonstrated a simple solvo-chemical and solvo-thermal route to design various nano-structures growth of zinc oxide (ZnO). The shapes and morphologies can be easily controlled by using different ambient conditions. We successfully fabricated ZnO nano-wires array on ITO substrate. Those nano-wire array center gradually formed micro-flower like structure evolved in this solvo-chemical route. This novel synthesis happened under cationic surfactant CTAB in the solution helps to form hierarchical structures of ZnO. The length of nano-wire is around 2.0 µm, which formed micro-flower diameter 5.0 µm. Micro-flowers were scratched out from ITO substrate thin film and annealed at 650 °C in electric oven for 1 hour, eventually this micro-flower transformed to novel nano-rose structure confirmed by electron microscopic study. Synthesized nano-rose diameter was around 730 nm. Moreover, we found a drastic change of dielectric behavior and DC conductivity of ZnO nanostructures depending on geometry regulated by the duration of preparation. Interestingly enough, optical and electrical properties also changed due to different crystalline structure formation. The dielectric constant is higher at 7.5 also high threshold voltages at 4 V, corresponds to nano-wires array with micro-flower system. A detail dielectric analysis of one step behavior of broad single relaxation peak was obtained only shows the normal dispersion in this system from 1000 kHz to 10 MHz. While less dielectric constant 1.7 and low threshold voltage 1 V, investigated nano-wires with micro-flower, then nano-rose transition appeared in two step behaviors of double relaxations phenomenon appeared one at low frequency and other at higher frequency region. Besides, I~V response characteristics is new idea about different breakdown voltages and bi-stable DC switching capability. Our work demonstrates the possibility of a fast novel synthesis route using a Solvo-chemical process for this type of nanomaterials

  3. "Cut wires grating – single longitudinal wire" planar metastructure to achieve microwave magnetic resonance in a single wire

    OpenAIRE

    G. Kraftmakher; V. Butylkin

    2012-01-01

    Here we present metastructures containing cut-wire grating and a single longitudinal cut-wire orthogonal to grating’s wires. Experimental investigations at microwaves show these structures can provide strong magnetic resonant response of a single nonmagnetic cut-wire in dependence on configuration and sizes in the case when metastructures are oriented along the direction of wave propagation and cut-wires of grating are parallel to the electric field of a plane electromagnetic wave. It is sugg...

  4. Experimental verification of the vaporization's contribution to the shock waves generated by underwater electrical wire explosion under micro-second timescale pulsed discharge

    Science.gov (United States)

    Han, Ruoyu; Zhou, Haibin; Wu, Jiawei; Clayson, Thomas; Ren, Hang; Wu, Jian; Zhang, Yongmin; Qiu, Aici

    2017-06-01

    This paper studies pressure waves generated by exploding a copper wire in a water medium, demonstrating the significant contribution of the vaporization process to the formation of shock waves. A test platform including a pulsed current source, wire load, chamber, and diagnostic system was developed to study the shock wave and optical emission characteristics during the explosion process. In the experiment, a total of 500 J was discharged through a copper wire load 0.2 mm in diameter and 4 cm in length. A water gap was installed adjacent to the load so that the current was diverted away from the load after breakdown occurred across the water gap. This allows the electrical energy injection into the load to be interrupted at different times and at different stages of the wire explosion process. Experimental results indicate that when the load was bypassed before the beginning of the vaporization phase, the measured peak pressure was less than 2.5 MPa. By contrast, the peak pressure increased significantly to over 6.5 MPa when the water gap broke down after the beginning of the vaporization phase. It was also found that when bypassing the load after the voltage peak, similar shock waves were produced to those from a non-bypassed load. However, the total optical emission of these bypassed loads was at least an order of magnitude smaller. These results clearly demonstrate that the vaporization process is vital to the formation of shock waves and the energy deposited after the voltage collapse may only have a limited effect.

  5. 30 CFR 57.12047 - Guy wires.

    Science.gov (United States)

    2010-07-01

    ... Underground § 57.12047 Guy wires. Guy wires of poles supporting high-voltage transmission lines shall meet the... “Safety Rules for the Installation and Maintenance of Electric Supply and Communication Lines”...

  6. Microstructure changes during non-conventional heat treatment of thin Ni-Ti wires by pulsed electric current studied by transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Delville, R., E-mail: remi.delville@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Malard, B.; Pilch, J.; Sittner, P. [Institute of Physics, Na Slovance 2, 182 21 Praha (Czech Republic); Schryvers, D. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2010-08-15

    Transmission electron microscopy, electrical resistivity measurements and mechanical testing were employed to investigate the evolution of microstructure and functional superelastic properties of 0.1 mm diameter as-drawn Ni-Ti wires subjected to a non-conventional heat treatment by controlled electric pulse currents. This method enables a better control of the recovery and recrystallization processes taking place during the heat treatment and accordingly a better control on the final microstructure. Using a stepwise approach of millisecond pulse annealing, it is shown how the microstructure evolves from a severely deformed state with no functional properties to an optimal nanograined microstructure (20-50 nm) that is partially recovered through polygonization and partially recrystallized and that has the best functional properties. Such a microstructure is highly resistant against dislocation slip upon cycling, while microstructures annealed for longer times and showing mostly recrystallized grains were prone to dislocation slip, particularly as the grain size exceeds 200 nm.

  7. Donor impurity states and related terahertz range nonlinear optical response in GaN cylindrical quantum wires: Effects of external electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Correa, J. D. [Departamento de Ciencias Básicas, Universidad de Medellín, Medellín (Colombia); Mora-Ramos, M. E., E-mail: memora@uaem.mx [Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, CP 62209 Cuernavaca, Morelos (Mexico); Duque, C. A. [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

    2014-06-07

    We report a study on the optical absorption coefficient associated to hydrogenic impurity interstate transitions in zinc-blende GaN quantum wires of cylindrical shape taking into account the effects of externally applied static electric and magnetic fields. The electron states emerge within the effective mass approximation, via the exact diagonalization of the donor-impurity Hamiltonian with parabolic confinement and external field effects. The nonlinear optical absorption is calculated using a recently derived expression for the dielectric susceptibility, obtained via a nonperturbative solution of the density-matrix Bloch equation. Our results show that this treatment eliminates not only the intensity-dependent bleaching effect but also the change in sign of the nonlinear contribution due to the combined effect of asymmetric impurity location and the applied electric field.

  8. Donor impurity states and related terahertz range nonlinear optical response in GaN cylindrical quantum wires: Effects of external electric and magnetic fields

    Science.gov (United States)

    Correa, J. D.; Mora-Ramos, M. E.; Duque, C. A.

    2014-06-01

    We report a study on the optical absorption coefficient associated to hydrogenic impurity interstate transitions in zinc-blende GaN quantum wires of cylindrical shape taking into account the effects of externally applied static electric and magnetic fields. The electron states emerge within the effective mass approximation, via the exact diagonalization of the donor-impurity Hamiltonian with parabolic confinement and external field effects. The nonlinear optical absorption is calculated using a recently derived expression for the dielectric susceptibility, obtained via a nonperturbative solution of the density-matrix Bloch equation. Our results show that this treatment eliminates not only the intensity-dependent bleaching effect but also the change in sign of the nonlinear contribution due to the combined effect of asymmetric impurity location and the applied electric field.

  9. Measurement of air distribution and void fraction of an upwards air-water flow using electrical resistance tomography and a wire-mesh sensor

    Science.gov (United States)

    Olerni, Claudio; Jia, Jiabin; Wang, Mi

    2013-03-01

    Measurements on an upwards air-water flow are reported that were obtained simultaneously with a dual-plane electrical resistance tomograph (ERT) and a wire-mesh sensor (WMS). The ultimate measurement target of both ERT and WMS is the same, the electrical conductivity of the medium. The ERT is a non-intrusive device whereas the WMS requires a net of wires that physically crosses the flow. This paper presents comparisons between the results obtained simultaneously from the ERT and the WMS for evaluation and calibration of the ERT. The length of the vertical testing pipeline section is 3 m with an internal diameter of 50 mm. Two distinct sets of air-water flow rate scenarios, bubble and slug regimes, were produced in the experiments. The fast impedance camera ERT recorded the data at an approximate time resolution of 896 frames per second (fps) per plane in contrast with the 1024 fps of the wire-mesh sensor WMS200. The set-up of the experiment was based on well established knowledge of air-water upwards flow, particularly the specific flow regimes and wall peak effects. The local air void fraction profiles and the overall air void fraction were produced from two systems to establish consistency for comparison of the data accuracy. Conventional bulk flow measurements in air mass and electromagnetic flow metering, as well as pressure and temperature, were employed, which brought the necessary calibration to the flow measurements. The results show that the profiles generated from the two systems have a certain level of inconsistency, particularly in a wall peak and a core peak from the ERT and WMS respectively, whereas the two tomography instruments achieve good agreement on the overall air void fraction for bubble flow. For slug flow, when the void fraction is over 30%, the ERT underestimates the void fraction, but a linear relation between ERT and WMS is still observed.

  10. Effects of Thermal and Solvent Aging on Breakdown Voltage of TPE, PBT/PET Alloy, and PBT Insulated Low Voltage Electric Wire

    Directory of Open Access Journals (Sweden)

    Eun-Soo Park

    2013-01-01

    Full Text Available Tests were performed to evaluate the effects of thermal and solvent aging on the mechanical and dielectric breakdown properties of four types of polyester resins, namely, the insulation layer of poly(butylene terephthalat (PBT- based thermoplastic elastomer (TPE, TPE1, poly(butylene 2,6-naphthalate-based TPE (TPE2, PBT/poly(ethylene terephthalate alloy (Alloy, and PBT extruded onto a copper conductor of low voltage electric wire. The tensile specimens used in this series were prepared from the same extruded resins. The prepared electric wires and tensile specimens were thermally aged in air and in toluene, xylene, TCB, and NMP. When Alloy and PBT were thermally aged in toluene, xylene and TCB at 120°C for 6 h, the tensile properties were significantly decreased compared to TPE1 and TPE2 at the same condition. The reduction of elongation at break of Alloy was more discernible than that of PBT. This result indicated that Alloy is more affected by thermal and solvent ageing. Among them, TPE2 showed the highest breakdown voltage (BDV, and it has also the highest BDV after thermal and solvent aging.

  11. Diagnostics of underwater electrical wire explosion through a time- and space-resolved hard x-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Sheftman, D.; Shafer, D.; Efimov, S.; Gruzinsky, K.; Gleizer, S.; Krasik, Ya. E. [Physics Department, Technion, Haifa 32000 (Israel)

    2012-10-15

    A time- and space-resolved hard x-ray source was developed as a diagnostic tool for imaging underwater exploding wires. A {approx}4 ns width pulse of hard x-rays with energies of up to 100 keV was obtained from the discharge in a vacuum diode consisting of point-shaped tungsten electrodes. To improve contrast and image quality, an external pulsed magnetic field produced by Helmholtz coils was used. High resolution x-ray images of an underwater exploding wire were obtained using a sensitive x-ray CCD detector, and were compared to optical fast framing images. Future developments and application of this diagnostic technique are discussed.

  12. Limiting oxygen concentration for extinction of upward spreading flames over inclined thin polyethylene-insulated NiCr electrical wires with opposed-flow under normal- and micro-gravity

    KAUST Repository

    Hu, Longhua

    2016-10-02

    Materials, such as electrical wire, used in spacecraft must pass stringent fire safety standards. Tests for such standards are typically performed under normal gravity conditions and then extended to applications under microgravity conditions. The experiments reported here used polyethylene (PE)-insulated (thickness of 0.15 mm) Nichrome (NiCr)-core (diameter of 0.5 mm) electrical wires. Limiting oxygen concentrations (LOC) at extinction were measured for upward spreading flame at various forced opposed-flow (downward) speeds (0−25 cm/s) at several inclination angles (0−75°) under normal gravity conditions. The differences from those previously obtained under microgravity conditions were quantified and correlated to provide a reference for the development of fire safety test standards for electrical wires to be used in space exploration. It was found that as the opposed-flow speed increased for a specified inclination angle (except the horizontal case), LOC first increased, then decreased and finally increased again. The first local maximum of this LOC variation corresponded to a critical forced flow speed resulted from the change in flame spread pattern from concurrent to counter-current type. This critical forced flow speed correlated well with the buoyancy-induced flow speed component in the wire\\'s direction when the flame base width along the wire was used as a characteristic length scale. LOC was generally higher under the normal gravity than under the microgravity and the difference between the two decreased as the opposed-flow speed increases, following a reasonably linear trend at relatively higher flow speeds (over 10 cm/s). The decrease in the difference in LOC under normal- and microgravity conditions as the opposed-flow speed increases correlated well with the gravity acceleration component in the wire\\'s direction, providing a measure to extend LOC determined by the tests under normal gravity conditions (at various inclination angles and opposed

  13. Wiring and lighting

    CERN Document Server

    Kitcher, Chris

    2013-01-01

    Wiring and Lighting provides a comprehensive guide to DIY wiring around the home. It sets out the regulations and legal requirements surrounding electrical installation work, giving clear guidelines that will enable the reader to understand what electrical work they are able to carry out, and what the testing and certification requirements are once the work is completed. Topics covered include: Different types of circuits; Types of cables and cable installation under floors and through joists; Isolating, earthing and bonding; Accessory boxes and fixings; Voltage bands; Detailed advice on safe

  14. Impurity-related optical properties in rectangular-transverse section GaAs-Ga{sub 1-x}Al{sub x}As quantum well wires: Hydrostatic pressure and electric field effects

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.W.; Duque, C.A. [Instituto de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia); Lopez, S.Y. [Facultad de Educacion, Universidad de Antioquia, AA 1226, Medellin (Colombia); Rodriguez, A.H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico (UNAM), Apdo. Postal 20-364, San Angel 01000, Mexico DF (Mexico); Porras-Montenegro, N. [Departamento de Fisica, Universidad del Valle, AA 25360, Cali (Colombia)

    2007-01-15

    Using a variational procedure within the effective mass approximation, we have calculated the influence of an applied electric field and hydrostatic pressure on the shallow-impurity-related optical properties in a rectangular-transverse section GaAs-Ga{sub 1-x}Al{sub x}As quantum well wire. The electric field is applied in the plane of the transverse section of the wire and different angular directions have been considered. The results presented are for the impurity binding energy, its corresponding density of impurity states, and impurity-related transition energy and polarizability. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Twin Baryogenesis

    CERN Document Server

    Farina, Marco; Shin, Chang Sub

    2016-01-01

    In the context of Twin Higgs models, we study a simple mechanism that simultaneously generates asymmetries in the dark and visible sector through the out-of-equilibrium decay of a TeV scale particle charged under a combination of baryon and twin baryon number. We predict the dark matter to be a 5 GeV twin baryon, which is easy to achieve because of the similarity between the two confinement scales. Dark matter is metastable and can decay to three quarks, yielding indirect detection signatures. The mechanism requires the introduction of a new colored particle, typically within the reach of the LHC, of which we study the rich collider phenomenology, including prompt and displaced dijets, multi-jets, monojets and monotops.

  16. Twin - Arch technique. Revival of the "edgewise -Technique"?

    Directory of Open Access Journals (Sweden)

    Jacob Karp

    2012-01-01

    The SNB – Bracket brings a new dimension into the orthodontic world which is most apparent in extraction cases. Its Teflon – like material has a very low friction coefficient thus, reducing the treatment time considerably. Through the use of low dimensioned arch wires, the Twin – Arch Technique becomes a Light – wire system and simultaneously provides good anchorage and torque control.

  17. Utilisation of the magnetic sensor in a smartphone for facile magnetostatics experiment: magnetic field due to electrical current in straight and loop wires

    Science.gov (United States)

    Septianto, R. D.; Suhendra, D.; Iskandar, F.

    2017-01-01

    This paper reports on the result of a research into the utilisation of a smartphone for the study of magnetostatics on the basis of experiments. The use of such a device gives great measurement result and thus it can replace magnetic sensor tools that are relatively expensive. For the best experimental result, firstly the position of the magnetic sensor in the smartphone has to be considered by way of value mapping of a magnetic field due to permanent magnet. The magnetostatics experiment investigated in this research was the measurement of magnetic field due to electrical currents in two shapes of wire, straight and looped. The current flow, the distance between the observation point and the wire, and the diameter of the loop were the variable parameters investigated to test the smartphone’s capabilities as a measurement tool. To evaluate the experimental results, the measured data were compared with theoretical values that were calculated by using both an analytical and a numerical approach. According to the experiment results, the measured data had good agreement with the results from the analytical and the numerical approach. This means that the use of the magnetic sensor in a smartphone in physics experiments is viable, especially for magnetic field measurement.

  18. Investigation of electrically active defects in InGaAs quantum wire intermediate-band solar cells using deep-level transient spectroscopy technique

    Science.gov (United States)

    Saqri, Noor alhuda Al; Felix, Jorlandio F.; Aziz, Mohsin; Kunets, Vasyl P.; Jameel, Dler; Taylor, David; Henini, Mohamed; Abd El-sadek, Mahmmoud S.; Furrow, Colin; Ware, Morgan E.; Benamara, Mourad; Mortazavi, Mansour; Salamo, Gregory

    2017-01-01

    InGaAs quantum wire (QWr) intermediate-band solar cell-based nanostructures grown by molecular beam epitaxy are studied. The electrical and interface properties of these solar cell devices, as determined by current-voltage (I-V) and capacitance-voltage (C-V) techniques, were found to change with temperature over a wide range of 20-340 K. The electron and hole traps present in these devices have been investigated using deep-level transient spectroscopy (DLTS). The DLTS results showed that the traps detected in the QWr-doped devices are directly or indirectly related to the insertion of the Si δ-layer used to dope the wires. In addition, in the QWr-doped devices, the decrease of the solar conversion efficiencies at low temperatures and the associated decrease of the integrated external quantum efficiency through InGaAs could be attributed to detected traps E1QWR_D, E2QWR_D, and E3QWR_D with activation energies of 0.0037, 0.0053, and 0.041 eV, respectively.

  19. Investigation of electrically active defects in InGaAs quantum wire intermediate-band solar cells using deep-level transient spectroscopy technique.

    Science.gov (United States)

    Al Saqri, Noor Alhuda; Felix, Jorlandio F; Aziz, Mohsin; Kunets, Vasyl P; Jameel, Dler; Taylor, David; Henini, Mohamed; Abd El-Sadek, Mahmmoud S; Furrow, Colin; Ware, Morgan E; Benamara, Mourad; Mortazavi, Mansour; Salamo, Gregory

    2017-01-27

    InGaAs quantum wire (QWr) intermediate-band solar cell-based nanostructures grown by molecular beam epitaxy are studied. The electrical and interface properties of these solar cell devices, as determined by current-voltage (I-V) and capacitance-voltage (C-V) techniques, were found to change with temperature over a wide range of 20-340 K. The electron and hole traps present in these devices have been investigated using deep-level transient spectroscopy (DLTS). The DLTS results showed that the traps detected in the QWr-doped devices are directly or indirectly related to the insertion of the Si δ-layer used to dope the wires. In addition, in the QWr-doped devices, the decrease of the solar conversion efficiencies at low temperatures and the associated decrease of the integrated external quantum efficiency through InGaAs could be attributed to detected traps E1QWR_D, E2QWR_D, and E3QWR_D with activation energies of 0.0037, 0.0053, and 0.041 eV, respectively.

  20. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  1. An Analysis of Magnetic Field Environment Near High-Voltage Power Lines and Contact Wires of Electric Railways

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Image method is used in this paper to calculate the value of magnetic field near high-voltage transmission lines and electric railways. Areas in which the magnetic field is less than 0.002 Gauss are given and the magnetic pollution of high-voltage power transmission lines and electric railways is discussed

  2. Evaluation of mechanical and electrical properties for an aluminium alloy thermo resistant for application in electrical cables and wires; Avaliacao das propriedades mecanicas e eletricas para uma liga de aluminio termorresistente para aplicacao em fios e cabos eletricos

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, M.A.; Reis, W.L.S.; Souza, A.T.M.D.; Quaresma, J.M.V. [Universidade Federal do Para, Belem, PA (Brazil)

    2010-07-01

    With the constant growth of brazilian industry and, consequently, the demand for electric power, realized the need to develop new metal alloys for use in wire and cable transmission and distribution of electricity to support the high temperatures which will be submitted. this study is based on the modification of aluminum by contents of Zr. the alloys were cast into ingot shaped {sup u,} after machined to a diameter of 18 mm, were homogenized and cold-worked (rolled). subsequently underwent a series of heat treatments at temperatures (230 degree c, 310 degree c and 390 degree c) for one hour in order to obtain the recrystallization temperature of alloys and demonstrate its potential for thermo resistant. With the inclusion of increasing contents of Zr, the alloy showed a higher recrystallization temperature and an increase in their limit of tensile strength. (author)

  3. 49 CFR 393.28 - Wiring systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Wiring systems. 393.28 Section 393.28 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.28 Wiring systems...

  4. Qualitative modifications and new dynamic phases in the phase diagram of one-dimensional superconducting wires driven with electric currents

    Science.gov (United States)

    Kallush, Shimshon; Berger, Jorge

    2014-06-01

    After an initial transient period, the conduction regime in a one-dimensional superconducting wire that carries a fixed current is either normal, periodic, or stationary. The phase diagram for these possibilities was studied in Phys. Rev. Lett. 99, 167003 (2007), 10.1103/PhysRevLett.99.167003 for particular values of the length and the material parameters. We have extended this study to arbitrary length and to a range of material parameters that includes realistic values. Variation of the length leads to scaling laws for the phase diagram. Variation of the material parameters leads to new qualitative features and new phases, including a parameter region in which all three regimes are possible.

  5. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  6. Modern wiring practice

    CERN Document Server

    Steward, W E

    2012-01-01

    Continuously in print since 1952, Modern Wiring Practice has now been fully revised to provide an up-to-date source of reference to building services design and installation in the 21st century. This compact and practical guide addresses wiring systems design and electrical installation together in one volume, creating a comprehensive overview of the whole process for contractors and architects, as well as electricians and other installation engineers. Best practice is incorporated throughout, combining theory and practice with clear and accessible explanation, all

  7. Synthesis and characterization of magnetic of Ni/ABS nanocomposites by electrical explosion of wire in liquid and solution blending methods

    Science.gov (United States)

    Thuyet-Nguyen, Minh; Hai-Nguyen, Hong; Kim, Won Joo; Kim, Ho Yoon; Kim, Jin-Chun

    2017-03-01

    Nanomaterials have attracted great attention from chemists, physicists and materials scientists because of their application benefits and special properties. Thermoplastics have been used in many applications such as molding of non-electrical components, conducting, magnetic field and 3D printing. Nanocomposites are known as a material which blends the best properties of components, a high performance material exhibits unusual property combinations and unique design possibilities. In this research, we focused to investigate and report primary results in the synthesis of magnetic nanocomposites based on acrylonitrile butadiene styrene (ABS), which are useful and important thermoplastics. Nickel nanopowder was prepared by electrical explosion of wire in a liquid were used as magnetic component. The composites were prepared by following steps, first the obtained Ni nanopowders were incorporated into the ABS matrix via a solution blending method (drop-casting), and then the solvent was evaporated. The characterizations of obtaining composites were analyzed by field emission scanning electron microscopy, X-Ray Diffraction analysis and vibrating sample magnetometer.

  8. 广州九号线蓄电池电力工程车布线设计%The wiring design of Guangzhou Metro Line 9 battery electric engineering locomotive

    Institute of Scientific and Technical Information of China (English)

    黄海; 郭婉露; 王文丰

    2016-01-01

    This paper first presents the fundamental principle and cable selection method of the wiring design of Guangzhou Metro Line 9 battery electric engineering locomotive,the wiring design was analyzed in detail from three aspects including main circuit ,auxiliary circuit and control circuit.%介绍了广州九号线蓄电池电力工程车布线设计的基本原则以及电缆选型方法,从主电路、辅助电路以及控制电路三个方面详细分析了布线设计方案。

  9. USE OF SECONDARY HEAT FOR DECREASE IN ELECTRICITY CONSUMPTION IN THE COURSE OF BURIROVANIYA OF THE WIRE

    Directory of Open Access Journals (Sweden)

    E. V. Chebotaryov

    2016-01-01

    Full Text Available In article introduction of an energy saving activity in technological process of wire’s surfacing by borate of soda during drawing is described. This activity is directed to decrease in electricity consumption for heating of solution in borate of soda bathtubs by use of the recovered heat of steel-smelting shops and is described in the article.

  10. Research on Variable Transmission Ratio and Yaw Rate Control Strategy of Electric Forklift Steering-by-Wire System

    Directory of Open Access Journals (Sweden)

    Guohua Xiang

    2016-10-01

    Full Text Available Combined with the trans mission ratio characteristics of forklift steering-by-wire (SBW system, through the application of fuzzy control technology, the variable trans mission ratio function is designed based on the steering handle angle and vehicle speed, and simulation analysis of sinusoidal steering is done at low-speed and high-speed. Simulation results show that the fuzzy variable transmission ratio control can make forklift steering light & sensitive at low-speed and steering steady & heavy at high speed, also it can improve the operation stability and reduce the driver’s load. Discuss the relationship between yaw rate and forklift handling stability, propose the yaw rate feedback control strategy based on the fuzzy variable transmission ratio control, and design a fuzzy self-adaptive PID controller. Simulation results show that the SBW system based on the fuzzy variable trans mission ratio control with yaw rate feedback can accurately and quickly track the desired yaw rate, and reduce or even eliminate the overshoot phenomenon, improve the forklift dynamic performance.

  11. IEE wiring regulations explained and illustrated

    CERN Document Server

    Scaddan, Brian

    2013-01-01

    The IEE Wiring Regulations Explained and Illustrated, Second Edition discusses the recommendations of the IEE Regulations for the Electrical Equipment of Buildings for the safe selection or erection of wiring installations. The book emphasizes earthing, bonding, protection, and circuit design of electrical wirings. The text reviews the fundamental requirements for safety, earthing systems, the earth fault loop impedance, and supplementary bonding. The book also describes the different types of protection, such as protection against mechanical damage, overcurrent, under voltage (which prevents

  12. Diamagnetism in wire medium metamaterials: theory and experiment

    CERN Document Server

    Yagupov, Ilya; Kosulnikov, Sergei; Hasan, Mehedi; Iorsh, Ivan; Belov, Pavel

    2015-01-01

    Strong diamagnetic response of wire medium with finite wire radius is reported. Contrary to the previous works where it was assumed that the wire medium exhibits only the electric response, we show that the non-zero magnetic susceptibility has to be taken into account for proper effective medium description of the wire medium. Analytical and numerical results are supported by the experimental measurements.

  13. 30 CFR 57.12053 - Circuits powered from trolley wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuits powered from trolley wires. 57.12053... Electricity Surface and Underground § 57.12053 Circuits powered from trolley wires. Ground wires for lighting circuits powered from trolley wires shall be connected securely to the ground return circuit. Surface Only...

  14. Formation of Micron-size Particles During Process of Nano-powders Production by Wire Electrical Explosion%气体放电式丝电爆制备纳米粉中大颗粒的形成

    Institute of Scientific and Technical Information of China (English)

    毕学松; 朱亮

    2012-01-01

    To understand the mechanism of the micron-size particles formation in the process of nano-powders produced by the wire electrical explosion, the powders were collected by a quartz probe, and the characters of micron-size particies were analyzed. The results show that the micron-size particles proportion of the wire ends powders is higher than that of wire center section powders. With the increasing of initial charging voltage, the micron-size particles proportion of the wire every sections powders decreases, and finally reaches unanimity. During the process of the wire electrical explosion, the energy deposits into the wire mainly by the Joule heating at the wire center section. The charged particles which come from the plasma strike on the wire surface at a high speed. Some energy also can be injected into the wire end by this effect besides of the Joule heating.%为认识丝电爆制备纳米粉过程中大颗粒的形成特征,利用石英探针直接收集金属丝各个部分形成的粉末并进行显微分析.结果表明,丝端部形成的粉末中微米级大颗粒比例要比丝中间部分粉末中的比例大;随着初始电压的升高,丝端部与丝中间部分的粉末中微米级大颗粒比例都减小,并最终达到一致.气体放电式丝电爆过程中,丝中间部分主要通过焦耳加热的作用沉积能量;而丝端部还会受到等离子体中高温粒子的高速撞击作用,也会向丝端部沉积一部分能量.

  15. Internal Arc: People safety in the electrical wiring; Arco interno: Seguridad de las personas ante instalaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Inchausti, J. M.

    2009-07-01

    The aim of this article is to describe the internal arc phenomenon, an extremely fast, almost explosive and unattended process of transformation form an initial electric power to the generation of a pressure and heat wave inside the medium its produced its consequences for safety, current methods of limiting them and current regulations in general for equipment used in medium-voltage electrical distribution networks. Taking into account that this type of equipment is found thought the distribution network in both public buildings and unrestricted access areas, safety (of operators and the general public) must be taken into account in the design of equipment and installations to minimize the risk of internal arcs occurring. This is the gist of, for example, ITC 16 of the Spanish Regulation on Power Plants and transformer substations. In addition to the construction aspects specific to each device in which the manufacturer has to takes steps to minimize the risks of an internal arcs occurring. This is the gist of, for example, ITC 16 of the Spanish Regulation on Power Plants and transformer substations. In addition to the construction aspects specific to each device in which an internal arc occurring, it is understood to be vitally important that users, installers and designers of Medium Voltage installations are familiar with the installation conditions stated by the manufacturer and thus avoid risks. (Author) 14 refs.

  16. Mechanical twinning in small quartz crystals

    Science.gov (United States)

    Laughner, J. W.; Newnham, R. E.; Cross, L. E.

    1982-02-01

    Quartz is known to be ferrobielastic; that is, quartz crystals have domain states (Dauphiné twins) which differ in their elastic compliance values and which can be switched by an appropriately oriented stress. Polycrystalline quartz has also been reported (Tullis 1970) to show preferential orientation of these domains following application of large uniaxial stresses. These experiments were designed to study twinning of synthetic quartz “grains” (minimum size 0.07×0.07×0.02 cm) in specially-constructed composites and of grains in three natural quartz aggregates — a quartzite, a novaculite, and a jasper. Backreflection X-ray techniques were used to verify twinning in the composite grains, while special electroding and electrical detection allowed the twinning processes to be examined in “real time.” Small synthetic quartz crystals were found to behave identically to the massive samples previously studied. Electrical pulses due to the reversal of piezoelectric coefficient d 11 in twinned quartz were detected from quartzite and from the man-made composites. Novaculite also gave electrical pulses which were probably from twinning (evidenced by the correlation of expected and observed pulse sizes and shapes), while no pulses from the jaspers indicative of twinning were detected. Grain size distribution differences are considered the main structural reason for the different behaviors.

  17. Effect of the initial structure on the electrical property of crystalline silicon films deposited on glass by hot-wire chemical vapor deposition.

    Science.gov (United States)

    Chung, Yung-Bin; Lee, Sang-Hoon; Bae, Sung-Hwan; Park, Hyung-Ki; Jung, Jae-Soo; Hwang, Nong-Moon

    2012-07-01

    Crystalline silicon films on an inexpensive glass substrate are currently prepared by depositing an amorphous silicon film and then crystallizing it by excimer laser annealing, rapid thermal annealing, or metal-induced crystallization because crystalline silicon films cannot be directly deposited on glass at a low temperature. It was recently shown that by adding HCI gas in the hot-wire chemical vapor deposition (HWCVD) process, the crystalline silicon film can be directly deposited on a glass substrate without additional annealing. The electrical properties of silicon films prepared using a gas mixture of SiH4 and HCl in the HWCVD process could be further improved by controlling the initial structure, which was achieved by adjusting the delay time in deposition. The size of the silicon particles in the initial structure increased with increasing delay time, which increased the mobility and decreased the resistivity of the deposited films. The 0 and 5 min delay times produced the silicon particle sizes of approximately 10 and approximately 28 nm, respectively, in the initial microstructure, which produced the final films, after deposition for 300 sec, of resistivities of 0.32 and 0.13 Omega-cm, mobilities of 1.06 and 1.48 cm2 V(-1) S(-1), and relative densities of 0.87 and 0.92, respectively.

  18. 电雷管脚线成型工艺设备现状与发展趋势%Present Situation and Trends of Process and Equipment of Winding Electric Detonator Lighting Blasting Cap Wire

    Institute of Scientific and Technical Information of China (English)

    杨民刚; 夏光; 杨宗玲

    2014-01-01

    Basing on the production process of winding electric detonator lighting blasting cap wire, the present situation of process and equipment were discussed. With the guidance on the progress of civilian explosives materials technology, the development direction and technical ideas of process technology and equipment for winding electric detonator lighting blasting cap wire were put forward.%在简述电雷管脚线打把生产工艺的基础上,对工艺技术与设备现状进行了分析评述,结合民用爆炸物品技术进步指导意见,提出了工业电雷管脚线制作的工艺技术与设备发展方向和技术思路。

  19. 焊丝用高速层绕机的电气控制%Electric control of high speed layer winder for welding wire

    Institute of Scientific and Technical Information of China (English)

    李鹏; 文丰

    2013-01-01

    High speed layer winder for welding wire is made up take-up,pay-off,loop tension device and electric control system.To introduce functions and requirement of every sections,analyze welding wire coil diameter change in layer winding,the control system with coil diameter calculating and loop PID adjusting function was designed.The system takes S7-226PLC as core,and deploy PWS-5600 touch screen ; the take-up and pay-off were driven by motor with MD320 frequency converter control; adopting MODBUS protocol to data exchange.The every functions realizing courses are expounded,the diagrams of system consisting,initialization communication program and frequency converter parameters setting are given.The control system can make layer winder start and stop quickly,stable running,layer winding speed is up to 20 m/s,output in one shift is over 2 tons.%焊丝用高速层绕机由收线机、放线机、活套张力装置及电控部分组成,介绍各部分功能和要求,分析焊丝层绕过程中卷径的变化,设计出具有卷径计算和活套PID调节功能的控制系统.该系统以S7-226PLC为核心,并配置PWS-5600触摸屏;收线机、放线机均由MD320变频器控制的电动机驱动;采用MODBUS协议进行数据交换.详述各个功能的实现过程,并就系统组成、初始化通讯程序、变频器参数设定给出具体图表.该控制系统可使层绕机快速启停,平稳运行,层绕速度最高可达20 m/s,每班产量超过2t.

  20. Anisotropic ionic transport in quartz: the effect of twin boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Calleja, Mark [Mineral Physics Group, Department of Earth Sciences, University of Cambridge, Cambridge (United Kingdom)). E-mail: mcal00@esc.cam.ac.uk; Dove, Martin T.; Salje, Ekhard K.H. [Mineral Physics Group, Department of Earth Sciences, University of Cambridge, Cambridge (United Kingdom)

    2001-10-22

    Transport of Na{sup +} and Li{sup +} under the influence of an electric field in twinned quartz is simulated using molecular dynamics techniques. Comparison between bulk transport and transport along twin boundaries shows that the cations are trapped inside twin walls for weak fields along the crystallographic c-axis. Stronger fields lead to transport along twin walls with significantly lower mobility than in the bulk. With E along [110], transport in the wall is faster than in the bulk. We observe cation trapping preferentially in the twin walls when E is applied out of the plane of the wall. (author)

  1. Miniature bending manipulator for fetoscopic intrauterine laser therapy to treat twin-to-twin transfusion syndrome.

    Science.gov (United States)

    Yamashita, H; Matsumiya, K; Masamune, K; Liao, H; Chiba, T; Dohi, T

    2008-02-01

    Recent typical therapy for twin-to-twin transfusion syndrome (TTTS) is selective laser photocoagulation of anastomotic communicating vessels on the placenta using the fetoscopic approach. The difficulty of a conventional laser device approach for this procedure depends significantly on the placental location, so a new robotized device is required to bend the direction of laser irradiation flexibly within the narrow uterus. The authors designed a miniature bending mechanism impelled by a wire-guided linkage driving method that provides a stable procedure for bending laser irradiation from -90 degrees to 90 degrees . Using this bending mechanism, the authors developed a bending manipulator with a diameter of 3.5 mm and a hollow central channel with a diameter of 0.8 mm for passing a glass fiber for neodymium:yttrium-aluminum-garnet (Nd:YAG) laser photocoagulation. The bending mechanism is motorized by an electrical actuator and controlled by a grip-type interface with a small joystick. The robotized tip's part and the actuator's part are easily separable for cleaning and sterilization. In performance evaluations of the manipulator, the bending characteristics with a glass fiber were examined. The bending range was -52.6 degrees to 80 degrees, with a very small hysteresis error, and the bending repeatability error was 0.5 degrees +/- 0.2 degrees, which corresponds with the high accuracy of 0.2 +/- 0.1-mm positioning error at the glass fiber's tip. In the evaluation of Nd:YAG laser photocoagulation, the study confirmed that the manipulator performed effective laser photocoagulation of the placental phantom surface (underwater chicken liver). The large bending range, reaching 80 degrees, enabled a flexible approach from various directions with a high irradiation efficiency of no less than 96.6%. The authors' original miniature bending manipulator can change the laser irradiating direction with highly repeatable positioning accuracy for speedy, safe, and effective vessel

  2. The Qingdao Twin Registry

    DEFF Research Database (Denmark)

    Duan, Haiping; Ning, Feng; Zhang, Dongfeng;

    2013-01-01

    In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants...... of metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes...

  3. Circuit Diagram Illustration of Wiring Harness Electrical Junction Box in Front Cabin on HAIMA FSTAR%福仕达前舱线束电气盒电路图解

    Institute of Scientific and Technical Information of China (English)

    张震华; 李鹤丽; 牛鹏浩

    2011-01-01

    介绍海马福仕达豪华型微型客车的线束部件配置明细,并根据全车线束产品图纸,对前舱线束中电气盒的连接电路作出图解。当车载某电气设备不能正常工作时,本文可以作为参照,便于对连接电器设备的线束电路进行查找及故障的排除。%The author introduces the components listing of wiring harness on HAIMA FSTAR minibus(DELUXE);according to the wire harnesses drawing of entire vehicle,illustrates the junction circuit of wiring harness electrical junction box in front cabin.When an electrical equipment can not work normally,this article can be used as a reference in searching and clearing faults for harness circuit connecting electrical equipments.

  4. Twin Jet

    Science.gov (United States)

    Henderson, Brenda; Bozak, Rick

    2010-01-01

    Many subsonic and supersonic vehicles in the current fleet have multiple engines mounted near one another. Some future vehicle concepts may use innovative propulsion systems such as distributed propulsion which will result in multiple jets mounted in close proximity. Engine configurations with multiple jets have the ability to exploit jet-by-jet shielding which may significantly reduce noise. Jet-by-jet shielding is the ability of one jet to shield noise that is emitted by another jet. The sensitivity of jet-by-jet shielding to jet spacing and simulated flight stream Mach number are not well understood. The current experiment investigates the impact of jet spacing, jet operating condition, and flight stream Mach number on the noise radiated from subsonic and supersonic twin jets.

  5. Deformation twinning in monazite

    Energy Technology Data Exchange (ETDEWEB)

    Hay, R.S.; Marshall, D.B

    2003-10-20

    Polycrystalline monazite (LaPO{sub 4}) was deformed at room temperature by a spherical indenter. Deformation twins were identified by TEM in 70 grains. Five twin planes were found: (100) was by far the most common; (001) and (120) were less common; (122-bar)was rare, and kinks in (120) twins were identified as irrational '(483)' twin planes. The twinning modes on these planes were inferred from the expression of twinning shear at free surfaces, predictions of classical deformation twinning theory, and various considerations of twin morphology and crystal structure. Atomic shuffle calculations that allow formation of either a glide plane or a mirror plane at the twin interface were used to analyze twin modes. The inferred twin modes all have small atomic shuffles. For (001) twins, the smallest shuffles were obtained with a glide plane at the interface, with displacement vector R=((1)/(2))[010]. The results do not uniquely define a twin mode on (100), leaving open the possibility of more than one mode operating on this plane. Factors that may determine the operative deformation twinning modes are discussed. Crystal structure considerations suggest that the relative abundance of twinning modes may correlate with low shear modulus on the twin plane in the direction of twinning shear, and with a possible low-energy interface structure consisting of a layer of xenotime of one half-unit-cell thickness that could form at (100) and (001) twins. The three most common twins have low strains to low {sigma} coincidence site lattices (CSLs)

  6. Electrical Wiring of the Aldehyde Oxidoreductase PaoABC with a Polymer Containing Osmium Redox Centers: Biosensors for Benzaldehyde and GABA

    Directory of Open Access Journals (Sweden)

    Artavazd Badalyan

    2014-11-01

    Full Text Available Biosensors for the detection of benzaldehyde and g-aminobutyric acid (GABA are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below −0.15 V (vs. Ag|AgCl, 1 M KCl. The pH-dependence of benzaldehyde oxidation can be strongly influenced by the ionic strength. The effect is similar with the soluble osmium redox complex and therefore indicates a clear electrostatic effect on the bioelectrocatalytic efficiency of PaoABC in the osmium containing redox polymer. At lower ionic strength, the pH-optimum is high and can be switched to low pH-values at high ionic strength. This offers biosensing at high and low pH-values. A “reagentless” biosensor has been formed with enzyme wired onto a screen-printed electrode in a flow cell device. The response time to addition of benzaldehyde is 30 s, and the measuring range is between 10–150 µM and the detection limit of 5 µM (signal to noise ratio 3:1 of benzaldehyde. The relative standard deviation in a series (n = 13 for 200 µM benzaldehyde is 1.9%. For the biosensor, a response to succinic semialdehyde was also identified. Based on this response and the ability to work at high pH a biosensor for GABA is proposed by coimmobilizing GABA-aminotransferase (GABA-T and PaoABC in the osmium containing redox polymer.

  7. Electrical Wiring of the Aldehyde Oxidoreductase PaoABC with a Polymer Containing Osmium Redox Centers: Biosensors for Benzaldehyde and GABA.

    Science.gov (United States)

    Badalyan, Artavazd; Dierich, Marlen; Stiba, Konstanze; Schwuchow, Viola; Leimkühler, Silke; Wollenberger, Ulla

    2014-12-01

    Biosensors for the detection of benzaldehyde and γ-aminobutyric acid (GABA) are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below -0.15 V (vs. Ag|AgCl, 1 M KCl). The pH-dependence of benzaldehyde oxidation can be strongly influenced by the ionic strength. The effect is similar with the soluble osmium redox complex and therefore indicates a clear electrostatic effect on the bioelectrocatalytic efficiency of PaoABC in the osmium containing redox polymer. At lower ionic strength, the pH-optimum is high and can be switched to low pH-values at high ionic strength. This offers biosensing at high and low pH-values. A "reagentless" biosensor has been formed with enzyme wired onto a screen-printed electrode in a flow cell device. The response time to addition of benzaldehyde is 30 s, and the measuring range is between 10-150 µM and the detection limit of 5 µM (signal to noise ratio 3:1) of benzaldehyde. The relative standard deviation in a series (n = 13) for 200 µM benzaldehyde is 1.9%. For the biosensor, a response to succinic semialdehyde was also identified. Based on this response and the ability to work at high pH a biosensor for GABA is proposed by coimmobilizing GABA-aminotransferase (GABA-T) and PaoABC in the osmium containing redox polymer.

  8. The Norwegian Twin Registry.

    Science.gov (United States)

    Nilsen, Thomas S; Brandt, Ingunn; Magnus, Per; Harris, Jennifer R

    2012-12-01

    Norway has a long-standing tradition in twin research, but the data collected in several population-based twin studies were not coordinated centrally or easily accessible to the scientific community. In 2009, the Norwegian Twin Registry was established at the Norwegian Institute of Public Health (NIPH) in Oslo with the purpose of creating a single research resource for Norwegian twin data. As of today, the Norwegian Twin Registry contains 47,989 twins covering birth years 1895-1960 and 1967-1979; 31,440 of these twins consented to participate in health-related research. In addition, DNA from approximately 4,800 of the twins is banked at the NIPH biobank and new studies are continually adding new data to the registry. The value of the Norwegian twin data is greatly enhanced by the linkage opportunities offered by Norway's many nationwide registries, spanning a broad array of medical, demographic, and socioeconomic information.

  9. Temperature characteristics analysis of HIV partial disconnection wire

    Science.gov (United States)

    Lee, Dae-Dong; Shim, Jae-Myung; Lee, Yu-Sung; Jeong, Yun-Mi; Kim, Young-Dal

    2015-09-01

    Electric fires are caused mainly due to short circuits, overloads, and electric leakage. Of the causes, short circuits are caused by deteriorated insulation, poor contacts, and pressure damage. A partially disconnected wire refers to the status in which the wire section is partially cut, thus reducing the contact area compared to the normal state. Causes of partially disconnected wires, e.g., poor wire contacts and pressure damage, occur mostly in the wiring and in the device's contact area, and they locally increase the resistance, thus triggering thermal changes. Thus, this study simulated damage to a 450/750 V heat-resistant polyvinyl-chloride-insulated (HIV) wire used for preventing electric fires and analyzed the temperature characteristics of normal wires and partially disconnected wires.

  10. System and method for evaluating a wire conductor

    Science.gov (United States)

    Panozzo, Edward; Parish, Harold

    2013-10-22

    A method of evaluating an electrically conductive wire segment having an insulated intermediate portion and non-insulated ends includes passing the insulated portion of the wire segment through an electrically conductive brush. According to the method, an electrical potential is established on the brush by a power source. The method also includes determining a value of electrical current that is conducted through the wire segment by the brush when the potential is established on the brush. The method additionally includes comparing the value of electrical current conducted through the wire segment with a predetermined current value to thereby evaluate the wire segment. A system for evaluating an electrically conductive wire segment is also disclosed.

  11. In situ nanoindentation study on plasticity and work hardening in aluminium with incoherent twin boundaries.

    Science.gov (United States)

    Bufford, D; Liu, Y; Wang, J; Wang, H; Zhang, X

    2014-09-10

    Nanotwinned metals have been the focus of intense research recently, as twin boundaries may greatly enhance mechanical strength, while maintaining good ductility, electrical conductivity and thermal stability. Most prior studies have focused on low stacking-fault energy nanotwinned metals with coherent twin boundaries. In contrast, the plasticity of twinned high stacking-fault energy metals, such as aluminium with incoherent twin boundaries, has not been investigated. Here we report high work hardening capacity and plasticity in highly twinned aluminium containing abundant Σ3{112} incoherent twin boundaries based on in situ nanoindentation studies in a transmission electron microscope and corresponding molecular dynamics simulations. The simulations also reveal drastic differences in deformation mechanisms between nanotwinned copper and twinned aluminium ascribed to stacking-fault energy controlled dislocation-incoherent twin boundary interactions. This study provides new insight into incoherent twin boundary-dominated plasticity in high stacking-fault energy twinned metals.

  12. Results from some anode wire aging tests

    Energy Technology Data Exchange (ETDEWEB)

    Juricic, I.; Kadyk, J.A.

    1986-01-01

    Using twin setups to test anode wire aging in small gas avalanche tubes, a variety of different gas mixtures were tried and other parameters were varied to study their effects upon the gain drop, nomalized to charge transfer: - 1/Q dI/I. This was found to be quite sensitive to the purity of the gases, and also sensitive to the nominal gain and the gas flow rate. The wire surface material can also significantly affect the aging, as can additives, such as ethanol or water vapor. Certain gas mixtures have been found to be consistent with zero aging at the sensitivity level of this technique.

  13. Wire Chamber

    CERN Multimedia

    1986-01-01

    Two wire chambers made originally for the R807 Experiment at CERN's Intersecting Storage Rings. In 1986 they were used for the PS 201 experiment (Obelix Experiment) at LEAR, the Low Energy Antiproton Ring. The group of researchers from Turin, using the chambers at that time, changed the acquisition system using for the first time 8 bit (10 bit non linear) analog to digital conversion for incoming signals from the chambers. The acquisition system was controlled by 54 CPU and 80 digital signal processors. The power required for all the electronics was 40 kW. For the period, this system was one of the most powerful on-line apparatus in the world. The Obelix Experiment was closed in 1996. To find more about how a wire chamber works, see the description for object CERN-OBJ-DE-038.

  14. Flywheel system using wire-wound rotor

    Energy Technology Data Exchange (ETDEWEB)

    Chiao, Edward Young; Bender, Donald Arthur; Means, Andrew E.; Snyder, Philip K.

    2016-06-07

    A flywheel is described having a rotor constructed of wire wound onto a central form. The wire is prestressed, thus mitigating stresses that occur during operation. In another aspect, the flywheel incorporates a low-loss motor using electrically non-conducting permanent magnets.

  15. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A;

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  16. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  17. 基于 ArcEngine 的输电网地理接线图管理平台%Electric Grid of Geo graphical Wiring Diarg am Manaeg ment Platform Based on the ArcEngine

    Institute of Scientific and Technical Information of China (English)

    陈政文; 余代俊; 张颖

    2015-01-01

    In view of the traditional electric grid of geographical wiring diagram no tower actual coordinates, wireless road direction, no actual terrain、no attribute data and other issues, this paper uses the ArcEngine component development and spatial analysis tech-nology, build an electric grid of geographical wiring diagram management platform.The platform using database to store and manage tower coordinate data and other attribute data, integrate the existing terrain data and image data as the geographic base map, the plat-form not only marked wire tower in the reallocation, distribution and show the whole electric grid, but also has the attribute inquiry and spatial analysis function.Apply the platform to ya, an electric grid, the results show that compared with the traditional transmission network of geographical wiring diagram, based on ArcEngine development the management platform has good visual and spatial analy-sis ability, improved the management level of electric grid.%针对传统输电网地理接线图无杆塔实际坐标、无线路走向、无实际地形、无属性数据等问题,本文采用ArcEngine组件式开发技术及空间分析技术,构建一个输电网地理接线图管理平台。该平台利用数据库存储和管理杆塔坐标数据及其他属性数据,整合现有地形数据和影像数据作为地理底图,从而使得该平台不但具备属性查询和空间分析功能,而且能将杆塔位置标记于真实的地理位置中,显示出整个输电网络分布及走向。将该平台运用于雅安市输电网结果表明,与传统输电网地理接线图相比,基于ArcEngine的输电网地理接线图管理平台具有良好的直观性和较好的空间分析能力,提高了电网的运行管理水平。

  18. Monochorionic twin pregnancies

    NARCIS (Netherlands)

    Hack, K.E.A.

    2008-01-01

    Following widespread application of assisted reproductive technology modalities and the increased age of motherhood, the incidence of twin gestations has increased markedly. Twins are either monozygotic or dizygotic. Dizygotic (i.e. fraternal) twins result from the fertilization of two different egg

  19. 30 CFR 56.12047 - Guy wires.

    Science.gov (United States)

    2010-07-01

    ... wires of poles supporting high-voltage transmission lines shall meet the requirements for grounding or... Installation and Maintenance of Electric Supply and Communication Lines” (also referred to as National...

  20. Electrical contracting

    CERN Document Server

    Neidle, Michael

    2013-01-01

    Electrical Contracting, Second Edition is a nine-chapter text guide for the greater efficiency in planning and completing installations for the design, installation and control of electrical contracts. This book starts with a general overview of the efficient cabling and techniques that must be employed for safe wiring design, as well as the cost estimation of the complete electrical contract. The subsequent chapters are devoted to other electrical contracting requirements, including electronic motor control, lighting, and electricity tariffs. A chapter focuses on the IEE Wiring Regulations an

  1. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  2. Development and Manufacture of Bi-2223 Wires

    Science.gov (United States)

    Kobayashi, Shin-Ichi

    This chapter reviews Ag-sheathed (Bi, Pb)2Sr2Ca2Cu3Ox (Bi-2223) wire made by the powder-in-tube technique (PIT). The currently leading high-temperature superconductors (HTS) wire technology for practical use is Bi-2223 wire, made by the controlled over-pressure (CT-OP) sintering process. The CT-OP process uses pressures up to 30MPa during heat treatment. The technique densifies the Bi-2223 filaments and enhances the uniformity of the electrical and mechanical performance in the Bi-2223 wire. Today, Bi-2223 wires are used in most HTS applications, such as power cables, many kinds of magnets, and motors for ship propulsion and electric vehicles.

  3. Space Station Freedom secondary power wiring requirements

    Science.gov (United States)

    Sawyer, C. R.

    1994-09-01

    Secondary power is produced by DDCU's (direct current to direct current converter units) and routed to and through secondary power distribution assemblies (SPDA's) to loads or tertiary distribution assemblies. This presentation outlines requirements of Space Station Freedom (SSF) EEE (electrical, electronic, and electromechanical) parts wire and the approved electrical wire and cable. The SSF PDRD (Program Definition and Requirements Document) language problems and resolution are reviewed. The cable routing to and from the SPDA's is presented as diagrams and the wire recommendations and characteristics are given.

  4. 三相四线静止式多功能电能表错误接线时退补电量算法研究%Error-wiring correction approach for three-phase four-wire static multifunctional electric energy meter

    Institute of Scientific and Technical Information of China (English)

    庞富宽; 丁恒春; 巨汉基; 郑蒙蒙; 妙红英

    2016-01-01

    电能的准确计量关系到电力企业和广大电力用户的切身利益。如果电能计量装置接线错误,将会引起计量差错,甚至造成经济纠纷。在纠正接线错误引起的电能计量差错过程中,多数情况下,确定更正系数是核算退补电量的前提。由于更正系数往往与功率因数角有关,且功率因数角又实时变化,因此将给退补电量的核算带来误差或不便。分析了三相四线静止式多功能电能表可能出现的错误接线情况,通过向量分析推导出实际有功电量与无功电量的表达式,实现了不依赖功率因数而进行退补电量的计算,提高了退补电量核算的准确性与便捷性。%Accurate measurement of electric energy is related to the immediate interests of the general electric power en-terprise and users. If there is an incorrect wiring event of the electric energy metering device, it will cause metering mis-take and even may cause economic disputes. In most process of correcting metering misalignment caused by incorrect connection, determining the correction coefficient is the precondition of calculating electricity for return or compensa-tion. The correction coefficient is often associated with the power factor angle which is probably real-time changing, what will bring calculating misalignment or inconvenience. This paper lists some possible event about false wiring of three-phase four-wire electric energy meter. The expression of actual active power and reactive power is deduced by means of vector analysis, what makes the calculation more accurate.

  5. Optical and Electrical Investigation of ZnO Nano-Wire Array to Micro-Flower from Hierarchical Nano-Rose Structures

    NARCIS (Netherlands)

    Pal, Kaushik; Zhan, Bihong; Ma, Xiao; Wang, Guoping; Schirhagl, Romana; Murgasen, Priya

    2016-01-01

    We have demonstrated a simple solvo-chemical and solvo-thermal route to design various nano-structures growth of zinc oxide (ZnO). The shapes and morphologies can be easily controlled by using different ambient conditions. We successfully fabricated ZnO nano-wires array on ITO substrate. Those nano-

  6. Optical and Electrical Investigation of ZnO Nano-Wire Array to Micro-Flower from Hierarchical Nano-Rose Structures

    NARCIS (Netherlands)

    Pal, Kaushik; Zhan, Bihong; Ma, Xiao; Wang, Guoping; Schirhagl, Romana; Murgasen, Priya

    2016-01-01

    We have demonstrated a simple solvo-chemical and solvo-thermal route to design various nano structures growth of zinc oxide (ZnO). The shapes and morphologies can be easily controlled by using different ambient conditions. We successfully fabricated ZnO nano-wires array on ITO substrate. Those nano-

  7. Optical and Electrical Investigation of ZnO Nano-Wire Array to Micro-Flower from Hierarchical Nano-Rose Structures

    NARCIS (Netherlands)

    Pal, Kaushik; Zhan, Bihong; Ma, Xiao; Wang, Guoping; Schirhagl, Romana; Murgasen, Priya

    We have demonstrated a simple solvo-chemical and solvo-thermal route to design various nano structures growth of zinc oxide (ZnO). The shapes and morphologies can be easily controlled by using different ambient conditions. We successfully fabricated ZnO nano-wires array on ITO substrate. Those

  8. Experimenting with wires, batteries, bulbs and the induction coil: Narratives of teaching and learning physics in the electrical investigations of Laura, David, Jamie, myself and the nineteenth century experimenters. Our developments and instruments

    Science.gov (United States)

    Cavicchi, Elizabeth Mary

    Physics is conventionally taught as a fixed curriculum which students must master. This thesis changes that: curriculum emerges from what learners try and question in experiments they invent. The thesis narrates: three adult students exploring wires, batteries and bulbs with me as teacher; nineteenth century investigations of electromagnetism; my laboratory work replicating historic instruments. In each case, learning arose through activity with materials. Evidences of this are analyzed within narratives and reflections. I used teaching-research, a method developed by Duckworth from Piaget's clinical interviewing, to research and simultaneously extend students' evolving understandings. What I learned through questioning students informed my next interactions; what they learned extended their experimenting. Similarly, I researched historical accounts interactively: improvising experiments to develop my understandings. Studying my own learning deepened my interpretations of students' learning. My students Laura, David and Jamie experimented by: soldering bulbs to wires, making series and parallel circuits, inserting resistive wire that dimmed bulbs, conducting electricity through salt water They noticed bulb brightness and battery heat, compared electricity's paths, questioned how voltage and current relate. They inferred electricity's effects manifest magnitudes of material properties. They found their experiences while learning were inseparable from what they learned. I researched investigations connected with Cavendish's leather fish, Galvani's frogs, Schweigger's wire spiraled around a compass needle, Henry's electromagnets, Faraday's induction ring, induction devices of Page, Callan, Hearder. Experimentally, I made galvanometers, electromagnets, induction rings, induction coil. I observed effects of electromagnetism, internal resistance, induced sparking. Across these investigations, learning developed with instrumental innovations; confusions were productive

  9. Measurement of Resistivity of Electric Resistance Wire and Evaluation of Uncertainty in Measurement Result%电阻丝电阻率的测量及测量结果的评定

    Institute of Scientific and Technical Information of China (English)

    郭琦

    2016-01-01

    The electrical resistivity of resistance wire was measured by Wheastone brige method.The component of uncertainty and degree of freedom were evaluated.The measurement uncertainty method of the bridge sensi-tivity was introduced. The measurement result and combined standard uncertainty of electrical resistivity were assessed.%采用惠斯通电桥测量了电阻丝的电阻率,对各不确定度分量及自由度进行了评定,描述了电桥灵敏度引入的测量不确定度评定方法,给出了电阻丝电阻率的测量值及不确定度评定结果。

  10. Development of experimental platform for airplane fly-by-wire and electric loading system%飞机电传操纵及模拟加载系统实验台开发

    Institute of Scientific and Technical Information of China (English)

    孟忱; 郝魁红; 何永勃

    2015-01-01

    Experimental platform for airplane fly‐by‐wire and electric loading system is designed to study the performance of airplane fly‐by‐wire control system and provide the experimental basis for the system . Hardware‐in‐the‐loop(HIL ) simulation of airplane control system can be completed .Students can adjust the aircraft attitude by a joystick of the experimental platform to simulate aircraft flight attitude adjustment .It can also do experiments such as permanent magnet synchronous motor system identification ,parameter debugging in PID control ,electric loading and the fault simulation of the four‐redundancy aircraft rudder .It can make students better understand the four‐redundancy EMA how to work .It also provide a platform for the research of fly‐by‐wire system .%为研究飞机电传操纵系统性能、给电传操纵系统设计提供实验依据,设计开发了飞机电传操纵及模拟加载系统实验台,实现全机飞控操纵系统半物理仿真。学生可以通过实验台操纵杆对飞机姿态进行调整,模拟飞机飞行过程中的姿态调整。并可完成永磁同步电机系统辨识、PID参数调试、电动加载模拟以及四余度方向舵故障模拟的实验,使学生更好熟悉四余度EM A机电作动器工作原理,为电传操纵系统的试验研究提供了平台。

  11. 9R structure in drawn industrial single crystal copper wires

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian; YAN Wen; FAN Xin-hui

    2009-01-01

    By using transmission electron microscopy, the microstructures of drawn industrial single crystal copper wires produced by Ohno Continuous Casting(OCC) process were analyzed. The results show that the typical microstructures in the wires mainly include extended planar dislocation boundaries, a small fraction of twins and some dislocation cells sharing boundaries parallel to drawn direction. Besides the typical microstructures, 9R structure configurations were observed in the wires. The formation of 9R polytypes may be caused by the coupled emission of Shockley dislocations from a boundary.

  12. Transformation and Discuss about Electrical System of DK7740 A Type Wire Cutting Machine%DK7740 A线切割机电气系统改造探讨∗

    Institute of Scientific and Technical Information of China (English)

    李杰

    2016-01-01

    DK7740A型线切割机由于原设计和配置电脑系统以及高频脉冲电源部分多为分立元件,受到当时电器制造技术发展的限制,元件性能差,发热严重,经常造成系统死机和高频脉冲电源不工作,严重影响生产的故障,对DK7740A线切割机电气系统进行改造,通过试验,改造使用效果良好。%The original design and configuration of computer system and high frequency pulse power supply parts of DK7740A type wire cutting machine are discrete components, which is limited by the development of electrical appliance manufacturing technology at that time, so component performance is very poor and is seriously heating, the system is often crashed and high frequency pulse power supply does not work usually. These have serious effects on producing. By transforming and testing the electrical system of DK7740A type wire cutting machine, It is found that the using effect is better.

  13. Design of a New Type of Reciprocating Travelling Wire Electrical-discharge Machines%新型往复走丝电火花线切割机床设计

    Institute of Scientific and Technical Information of China (English)

    张旭东; 岳伟栋

    2015-01-01

    Split type structure is widely used in high speed wire-cut electric discharge machine. The machine body, the electrical cabinet and the dielectric fluid cistern are detached. This structure is difficult in storage and transportation. On account of those defects ,all-in-one structure is conducted , but the heat produced by the electrical cabinet will have detrimental effects on mechanical precision. In addition,the dielectric fluid cistern is still split. In view of these disadvantages,new high speed wire-cut electric discharge machine is designed and introduced in this paper. Because of thermal insulation design,some disadvantages are overcame and machine tool′s aesthetics and the degree of automation are improved.%目前的往复走丝电火花线切割机床大多采用机床本体、电气箱、工作液箱三者分离的分体式结构,其储运较复杂;有些采用一体式结构的,由于电气箱紧凑安装于机床本体上,电气箱所带来的热量导入床体后会对机械精度产生不利影响,且工作液箱使用时还是分离的。针对这些弊端,研发了新型一体式结构的往复走丝电火花线切割机床,同时通过特殊隔热设计,克服了目前一体式结构的缺陷,提升了机床的整洁、美观和自动化程度。

  14. Microstructure and mechanical behavior of an as-drawn MP35N alloy wire

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M.J.N.V. [School of Engineering, Brown University, Providence, RI 02912 (United States); Reiterer, M.W. [Medtronic Incorporated, Science and Technology, Minneapolis, MN 55432 (United States); Kumar, K.S., E-mail: Sharvan_Kumar@brown.edu [School of Engineering, Brown University, Providence, RI 02912 (United States)

    2014-07-29

    The deformation response of low Ti (<0.1%), MP35N alloy (35% Co–35% Ni–20% Cr–10% Mo, all in wt%) wire with a ∼100 µm diameter was assessed in monotonic and cyclic loading modes. The as-drawn wire exhibited a strong 〈111〉 fiber texture and consisted of a hierarchically twinned microstructure with twins spanning the micrometer to nanometer scale; when deformed in this condition in uniaxial tension at room temperature, high strengths up to 2 GPa, limited tensile ductility of 3% and strain rate sensitivity in the quasi-static regime were noted. The deformed microstructure revealed evidence for slip, twinning and de-twinning, and in the necked region, in the vicinity where fracture had occurred, the fine twins appeared broken down into nanograins. The cyclic response of the as-drawn wire, evaluated using rotary beam bending (R=−1) and in tension–tension fatigue (R=0.3), appeared to be initiation-controlled and sensitive to the presence of extraneous second phase inclusions identified as Al{sub 2}O{sub 3} particles. Cyclically-deformed as{sub -}drawn wire samples displayed extensive de-twinning and multiple twin variants formation.

  15. "Cut wires grating – single longitudinal wire" planar metastructure to achieve microwave magnetic resonance in a single wire

    Directory of Open Access Journals (Sweden)

    G. Kraftmakher

    2012-09-01

    Full Text Available Here we present metastructures containing cut-wire grating and a single longitudinal cut-wire orthogonal to grating’s wires. Experimental investigations at microwaves show these structures can provide strong magnetic resonant response of a single nonmagnetic cut-wire in dependence on configuration and sizes in the case when metastructures are oriented along the direction of wave propagation and cut-wires of grating are parallel to the electric field of a plane electromagnetic wave. It is suggested a concept of magnetic response based on antiparallel resonant currents excited by magnetic field of surface polaritons in many spatial LC-circuits created from cut-wire pairs of a grating and section of longitudinal cut-wire. Three separately observed resonant effects connected with grating, LC-circuits and with longitudinal cut-wire have been identified applying measurements in waveguides, cutoff waveguides and free space. To tune and mark resonance split cut-wires are loaded with varactor diodes.

  16. Malaysian Twin Registry.

    Science.gov (United States)

    Jahanfar, Shayesteh; Jaffar, Sharifah Halimah

    2013-02-01

    The National Malaysian Twin Registry was established in Royal College of Medicine, Perak, University Kuala Lumpur (UniKL) in June 2008 through a grant provided by UniKL. The general objective is to facilitate scientific research involving participation of twins and their family members in order to answer questions of health and wellbeing relevant to Malaysians. Recruitment is done via mass media, poster, and pamphlets. We now have 266 adult and 204 children twins registered. Several research projects including reproductive health study of twins and the role of co-bedding on growth and development of children are carried out. Registry holds annual activities for twins and seeks to provide health-related information for twins. We seek international collaboration.

  17. Perinatal hepatic infarction in twin-twin transfusion.

    LENUS (Irish Health Repository)

    O'Sullivan, M J

    2012-02-03

    We report a case of a twin pregnancy which was complicated by a twin-twin transfusion in which the recipient twin was noted to have an intra-abdominal echogenic mass. This twin died at two days of age of hepatic infarction. The donor twin was healthy at birth, at thirty weeks\\' gestation, and did not have any subsequent problems. Fetal intra-abdominal echogenicity may be a marker of hepatic infarction.

  18. 46 CFR 111.30-19 - Buses and wiring.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Buses and wiring. 111.30-19 Section 111.30-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-19 Buses and wiring. (a) General. Each bus must meet the requirements...

  19. 30 CFR 75.1003 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Science.gov (United States)

    2010-07-01

    ... wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 75.1003 Section 75.1003... Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. Trolley wires, trolley feeder wires, and bare signal wires shall be insulated...

  20. The Brazilian Twin Registry.

    Science.gov (United States)

    Ferreira, Paulo H; Oliveira, Vinicius C; Junqueira, Daniela R; Cisneros, Lígia C; Ferreira, Lucas C; Murphy, Kate; Ordoñana, Juan R; Hopper, John L; Teixeira-Salmela, Luci F

    2016-12-01

    The Brazilian Twin Registry (BTR) was established in 2013 and has impelled twin research in South America. The main aim of the initiative was to create a resource that would be accessible to the Brazilian scientific community as well as international researchers interested in the investigation of the contribution of genetic and environmental factors in the development of common diseases, phenotypes, and human behavior traits. The BTR is a joint effort between academic and governmental institutions from Brazil and Australia. The collaboration includes the Federal University of Minas Gerais (UFMG) in Brazil, the University of Sydney and University of Melbourne in Australia, the Australian Twin Registry, as well as the research foundations CNPq and CAPES in Brazil. The BTR is a member of the International Network of Twin Registries. Recruitment strategies used to register twins have been through participation in a longitudinal study investigating genetic and environmental factors for low back pain occurrence, and from a variety of sources including media campaigns and social networking. Currently, 291 twins are registered in the BTR, with data on demographics, zygosity, anthropometrics, and health history having been collected from 151 twins using a standardized self-reported questionnaire. Future BTR plans include the registration of thousands of Brazilian twins identified from different sources and collaborate nationally and internationally with other research groups interested on twin studies.

  1. Delivery in Twin Gestation

    Directory of Open Access Journals (Sweden)

    Mark T. Peters

    1995-01-01

    Full Text Available Objective: The objective of this study was to determine whether prophylactic treatment with oral broad-spectrum antimicrobial therapy improves pregnancy outcomes in twin gestations.

  2. 聚合物膜上的微尺度金属导线在力电耦合作用下的屈曲行为%Buckling behavior of micro metal wire on polymer membrane under combined effect of electrical loading and mechanical loading

    Institute of Scientific and Technical Information of China (English)

    王庆华; 岸本哲; 谢惠民; 李艳杰; 吴丹

    2014-01-01

    The buckling behavior of a typical structure consisting of a micro constantan wire and a polymer membrane under coupled electrical-mechanical loading was studied. The phenomenon that the constantan wire delaminates from the polymer membrane was observed after unloading. The interfacial toughness of the constantan wire and the polymer membrane was estimated. Moreover, several new instability modes of the constantan wire could be further triggered based on the buckle-driven delamination. After electrical loading and tensile loading, the constantan wire was likely to fracture based on buckling. After electrical loading and compressive loading, the constantan wire was easily folded at the top of the buckling region. On the occasion, the constantan wire buckled towards the inside of the polymer membrane under electrical-compressive loading. The mechanisms of these instability modes were analyzed.%研究一种典型的微尺度康铜线/聚合物膜结构在力电耦合作用下的屈曲行为。根据卸载后康铜线从聚合物基底上屈曲的现象,评估康铜线与聚合物基底间的界面韧性。此外,力电耦合作用还会诱发新的失稳模态。在电载荷和拉伸载荷作用下,康铜线易在屈曲时发生断裂。在电载荷和压缩载荷作用下,康铜线易在屈曲区域的顶部发生折叠,偶尔还会向聚合物基底内部方向发生屈曲。分析了这些失稳模态的产生机理。

  3. Research of Relationship Between Interelectrode Dielectric Properties and Energy Distribution in Wire Electrical Discharge Machining%电火花线切割极问介电特性与放电能量分配关系

    Institute of Scientific and Technical Information of China (English)

    刘志东; 魏为; 陆霖琰; 徐安阳

    2012-01-01

    建立了电火花线切割极间介质电阻模型,分析了加工能量与极间介质电导率、工件厚度之间的关系,并对极间介质电阻模型进行了实验验证.研究结果表明,随着电导率的升高或者工件厚度的增加,放电期间极间“漏电流”增大,损耗在极间介质的能量增加,加工效率降低,电导率变化导致的极间电阻改变对于加工效率的影响显著.%A resistance model of (WEDM) was established. And interelectrode dielectric fluid in wire electrical discharge machining the relationship among machining energy, electrical conductivity and thickness of a workpiece was analyzed. The resistance model of interelectrode dielectric fluid was verified by experiments. The results show that with the higher electrical conductivity or the thickness of work- piece, the larger the interelectrode leakage current is during discharge, the more the energy loss in the in- terelectrode dielectric fluid, the lower the machining efficiency. Cutting efficiency is obviously influenced by the change of the resistance which is due to the change of electrical conductivity.

  4. Barcode Technology in Electric Power Communications Room Wiring Relationship Management%利用条码技术管理电力通信机房配线关系

    Institute of Scientific and Technical Information of China (English)

    宋来扣

    2015-01-01

    随着通信建设发展,电力通信机房配线系统模块数量巨大,维护工作繁重,设备接口及配线端子间连接关系使用传统的手工抄录,准确性差,效率低。容易造成数据不一致,漏录及查找不便,从而延缓电话、网络等重要业务缺陷的判断、分析与处理,严重影响机房设备的维护与管理效率。本文利用条码技术,配以智能终端应用软件管理电力机房配线连接关系,可以有效地解决上述问题,提高工作精益化水平。%With the development of communication construction, module distribution system of the electric power communication equipment room number is huge, heavy maintenance work, equipment interface and wiring terminals using traditional connection wiring manual transcriptions, poor accuracy, low effi ciency.It is easy to cause data inconsistency, dropout and searches inconvenience, analysis and processing, thus delaying the telephone, network and other important business judgment of defects, seriously affect the equipment maintenance and management efficiency.In this paper, using bar code technology, with connections to the intelligent terminal application software management in the power room wiring, can effectively solve the above problems, improve the work level.

  5. Comparison of Wired and Wireless Bio-Electrical Impedance Fluid Status Monitoring Devices and Validation to Body Mass and Urine Specific Gravity Changes Following Mild Dehydration

    Science.gov (United States)

    2008-01-18

    status assessment method, ZOE2, is FDA approved for fluid status monitoring. The ZOE2 measures thoracic bio -electrical impedance. A new wireless version...impedance as a valid measure of hydration status in clinical or controlled settings. However, there is speculation as to the utility of bio -electrical...no significant differences were detected between pre- to post-practice for the ZOE2 or ZOEW device. Bio -electrical impedance, as measured by the ZOEW

  6. Twin anemia polycythemia sequence

    NARCIS (Netherlands)

    Slaghekke, Femke

    2014-01-01

    In this thesis we describe that Twin Anemia Polycythemia Sequence (TAPS) is a form of chronic feto-fetal transfusion in monochorionic (identical) twins based on a small amount of blood transfusion through very small anastomoses. For the antenatal diagnosis of TAPS, Middle Cerebral Artery – Peak Syst

  7. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Ohm Kyvik, Kirsten; Vilstrup Holm, Niels

    2011-01-01

    Introduction: The Danish Twin Registry is a unique source for studies of genetic, familial and environmental factors on life events, health conditions and diseases. Content: More than 85,000 twin pairs born 1870-2008 in Denmark. Validity and coverage: Four main ascertainment methods have been emp...

  8. Twin anemia polycythemia sequence

    NARCIS (Netherlands)

    Slaghekke, Femke

    2014-01-01

    In this thesis we describe that Twin Anemia Polycythemia Sequence (TAPS) is a form of chronic feto-fetal transfusion in monochorionic (identical) twins based on a small amount of blood transfusion through very small anastomoses. For the antenatal diagnosis of TAPS, Middle Cerebral Artery – Peak

  9. A wire scanning type position monitor for an undulator radiation

    Science.gov (United States)

    Zhang, Xiaowei; Sugiyama, Hiroshi; Ando, Masami; Xia, Shaojian; Shiwaku, Hideaki

    1995-02-01

    A scanning wire position monitor for insertion devices was designed and installed in an x-ray undulator beam line. It consists of a graphite wire, a copper mesh for electric shielding, and a motor-driven linear guide. The wire of the monitor was tested under the undulator radiation thermal load. It has been found that the signal level of the monitor was proportional to the radiation power density on the wire. Even when the wire crossed the beam during the x-ray experiment, no detectable influence on the experiment was observed.

  10. Nano-storage wires.

    Science.gov (United States)

    Lee, Dong Jun; Kim, Eunji; Kim, Daesan; Park, Juhun; Hong, Seunghun

    2013-08-27

    We report the development of "nano-storage wires" (NSWs), which can store chemical species and release them at a desired moment via external electrical stimuli. Here, using the electrodeposition process through an anodized aluminum oxide template, we fabricated multisegmented nanowires composed of a polypyrrole segment containing adenosine triphosphate (ATP) molecules, a ferromagnetic nickel segment, and a conductive gold segment. Upon the application of a negative bias voltage, the NSWs released ATP molecules for the control of motor protein activities. Furthermore, NSWs can be printed onto various substrates including flexible or three-dimensional structured substrates by direct writing or magnetic manipulation strategies to build versatile chemical storage devices. Since our strategy provides a means to store and release chemical species in a controlled manner, it should open up various applications such as drug delivery systems and biochips for the controlled release of chemicals.

  11. Electric Power Transmission Lines

    Data.gov (United States)

    Department of Homeland Security — Transmission Lines are the system of structures, wires, insulators and associated hardware that carry electric energy from one point to another in an electric power...

  12. Electroanalysis using macro-, micro-, and nanochemical architectures on electrode surfaces. Bulk surface modification of glassy carbon microspheres with gold nanoparticles and their electrical wiring using carbon nanotubes.

    Science.gov (United States)

    Dai, Xuan; Wildgoose, Gregory G; Salter, Chris; Crossley, Alison; Compton, Richard G

    2006-09-01

    Gold nanoparticles (approximately 30-60 nm in diameter) were deposited onto the surface of glassy carbon microspheres (10-20 microm) through electroless plating to produce bulk (i.e., gram) quantities of nanoparticle surface-modified microspheres. The gold nanoparticle-modified powder was then characterized by means of scanning electron microscopy and cyclic voltammetry. The voltammetric response of a macroelectrode consisting of a film of gold nanoparticle-modified glassy carbon microspheres, bound together and "wired-up" using multiwalled carbon nanotubes (MWCNTs), was investigated. We demonstrate that by intelligently exploiting both nano- and microchemical architectures and wiring up the electroactive centers using MWCNTs in this way, we can obtain macroelectrode voltammetric behavior while only using approximately 1% by mass of the expensive gold material that would be required to construct the equivalent gold film macrodisk electrode. The potential utility of electrodes constructed using chemical architectures such as this was demonstrated by applying them to the analytical determination of arsenic(III) concentration. An optimized limit of detection of 2.5 ppb was obtained.

  13. Neonatal status of twins

    Directory of Open Access Journals (Sweden)

    Božinović Dragica

    2012-01-01

    Full Text Available Multiple pregnancy is a pregnancy where more than one fetus develops simultaneously in the womb, as a result of the ovulation and fertilization of more than one egg. It is relatively rare in humans and represents the rest of the phylogenetic stages. The most common are twins and they indicate the development of two fetuses in the womb. The frequency of twin pregnancies is about 1%. Multiple pregnancies belong to a group of high-risk pregnancies because of the many complications that occur during the pregnancy: higher number of premature deliveries, bleeding, early neonatal complications and higher perinatal morbidity and mortality. Such pregnancies and infants require greater supervision and monitoring. The aim of this study was to determine the percentage of baby twins born at the maternity ward of the General Hospital in Prokuplje and their morbidity and mortality. Data on the total number of deliveries, number of twins, parity and maternal age, gestational age, body weight of twins, method of delivery, Apgar score and perinatal mortality were collected and statistically analyzed by means of retrospective analysis of operative birth and neonatal protocol for 6 years (2005 of 2010. Out of 4527 mothers who gave birth 43 were pairs of twins, or 0.95% of women gave birth to twins. These babies are more likely born by Caesarean section, but delivered with slightly lower birth weight.

  14. Diagnosis of Electric Wiring in Starting System of Jie Fang CA1111 P1K2L7 Diesel Truck%解放牌CA111P1K2L7型柴油载货汽车起动系统电路故障诊断与排除

    Institute of Scientific and Technical Information of China (English)

    杨树森

    2001-01-01

    解放牌CA111P1K2L7型柴油载货汽车起动系统电路中增设了DK238型电源总开关和断油电磁铁,该装置具有电源电路和起动电路的保护作用。介绍了该起动系统电路的结构及工作原理,以及该电路的常见故障与诊断。%A DK238 main electric power switch and a fuel shutoff electromagnet are added into the electric wiring in starting system of Jie Fang CA1111P1K2L7 diesel truck. This device has a protection for electric power wiring and starting wiring. The structure and working principle, routine troubles and diagnosis of the electric wiring in the starting system are described.

  15. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2016-01-01

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  16. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2017-01-01

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  17. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2017-01-31

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  18. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  19. Simulation on Synchronization Control Strategy of Erecting Equipment with Twin Electric Cylinders%双电动缸起竖设备同步控制策略仿真研究

    Institute of Scientific and Technical Information of China (English)

    邓飙; 张潇; 郭君斌; 郭杨

    2016-01-01

    A parallel driving structure of twin electric cylinders was applied to ensure the fast and reliable erection of a certain de-vice. The erecting equipment is a multi-body system with complex electromechanical coupling effect, and the load variation exhibits un-certainty. Aiming at the non-synchronous problem in the equipment while the load for each cylinder is inconsistent, a master-slave ( MS) synchronization control scheme with relative coupling strategy was proposed, and a rule-based fuzzy PD synchronization control-ler was designed. The controller adopted the position error of two cylinders as the input, and position compensation signal for the slave cylinder as output. Simulation of twin cylinder equipment was conducted under extreme partial load conditions in MATLAB/Simulink environment. The result indicates that the MS control scheme can enable the system to meet the accuracy requirement for synchroniza-tion. Owing to the use of fuzzy PD controller, the synchronization error in starting process can be effectively restrained and the effects on synchronization error caused by the load disturbance can be successfully overcome.%为实现某型设备快速可靠地起竖,采用双电动缸并列驱动的结构.起竖设备是一个具有复杂机电耦合效应的多体系统,每支缸的负载变化规律不确定.针对设备在两缸负载不一致时,存在同步误差的问题,提出了一种带有偏差耦合策略的主从式同步控制方案,设计了基于规则的模糊PD同步控制器,以两缸位置误差为控制器输入量,以对从动缸的位置补偿量为输出量.在MATLAB/Simulink环境下模拟极限偏载情况,对双缸设备的起动和运行进行仿真.结果表明:主从同步控制方案使设备在偏载条件下也能达到同步精度要求,而采用模糊PD控制器既能有效抑制起动段的同步误差,又能克服负载扰动对同步误差的影响.

  20. Comparison of the copper and gold wire bonding processes for LED packaging*

    Institute of Scientific and Technical Information of China (English)

    Chen Zhaohui; Liu Yong; Liu Sheng

    2011-01-01

    Wire bonding is one of the main processes of the LED packaging which provides electrical interconnection between the LED chip and lead frame The gold wire bonding process has been widely used in LED packaging industry currently. However, due to the high cost of gold wire, copper wire bonding is a good substitute for the gold wire bonding which can lead to significant cost saving. In this paper, the copper and gold wire bonding processes on the high power LED chip are compared and analyzed with finite element simulation. This modeling work may provide guidelines for the parameter optimization of coppor wire bonding process on the high power LED packaging.

  1. Wire harness twisting aid

    Science.gov (United States)

    Casey, E. J.; Commadore, C. C.; Ingles, M. E.

    1980-01-01

    Long wire bundles twist into uniform spiral harnesses with help of simple apparatus. Wires pass through spacers and through hand-held tool with hole for each wire. Ends are attached to low speed bench motor. As motor turns, operator moves hand tool away forming smooth twists in wires between motor and tool. Technique produces harnesses that generate less radio-frequency interference than do irregularly twisted cables.

  2. Integrating the Gradient of the Thin Wire Kernel

    Science.gov (United States)

    Champagne, Nathan J.; Wilton, Donald R.

    2008-01-01

    A formulation for integrating the gradient of the thin wire kernel is presented. This approach employs a new expression for the gradient of the thin wire kernel derived from a recent technique for numerically evaluating the exact thin wire kernel. This approach should provide essentially arbitrary accuracy and may be used with higher-order elements and basis functions using the procedure described in [4].When the source and observation points are close, the potential integrals over wire segments involving the wire kernel are split into parts to handle the singular behavior of the integrand [1]. The singularity characteristics of the gradient of the wire kernel are different than those of the wire kernel, and the axial and radial components have different singularities. The characteristics of the gradient of the wire kernel are discussed in [2]. To evaluate the near electric and magnetic fields of a wire, the integration of the gradient of the wire kernel needs to be calculated over the source wire. Since the vector bases for current have constant direction on linear wire segments, these integrals reduce to integrals of the form

  3. Twin-twin Transfusion Syndrome with a Single Ectopic Kidney in a Twin Donor. Case Presentation

    Directory of Open Access Journals (Sweden)

    Gerardo Rogelio Robaina Castellanos

    2016-10-01

    Full Text Available Twin-twin Transfusion Syndrome presents more frequently in diamniotic monochromic twins. In advanced stages and without prenatal intervention, is associated to high rates of peri natal mortality and neurological sequel in the survivors. It is presented a case of a pair of twins with severe depression at birth in which it was diagnosed a Twin-twin Transfusion Syndrome, later confirmed with the presence of anemia in the donor twin and polycythemia in the receptor twin. Both twins had an unfavourable evolution with an early neonatal death. Necropsy findings were comparable with secondary damage to the syndrome, with the particularity that both had evidences of pulmonary infection and a renal malformation in the donor twin which is not included in the proper malformations of this syndrome. The objective of this work is to point out the essential elements for the diagnosis and antenatal treatment for this disease through the peculiarities of the presented case.

  4. Fullerton Virtual Twin Study.

    Science.gov (United States)

    Segal, Nancy L

    2006-12-01

    Virtual twins (VTs; same-age unrelated siblings reared together from early infancy) have been studied at California State University (CSU), Fullerton since 1991. The current sample includes over 130 pairs. Past and current research have research have focused on siblings' similarities and differences in general intelligence and body size. Future research in these areas will continue as new pairs continue to be identified. These studies will be supplemented by analyses of personality, social relations and adjustment using monozygotic (MZ) twins, dizygotic (DZ) twins, full siblings and friends, as well as new VTs, who have participated in Twins, Adoptees, Peers and Siblings (TAPS), a collaborative project conducted between CSU Fullerton and the University of San Francisco, from 2002 to 2006.

  5. Craniofacial anomalies in twins.

    Science.gov (United States)

    Keusch, C F; Mulliken, J B; Kaplan, L C

    1991-01-01

    Studies of twins provide insight into the relative contribution of genetic and environmental factors in the causality of structural anomalies. Thirty-five affected twin pairs were identified from a group of 1114 patients with congenital craniofacial deformities evaluated from 1972 to 1989. Forty-three of these 70 twins exhibited one or more craniofacial anomalies; these were analyzed for dysmorphic characteristics, zygosity, concordance, and family history. The anomalies were categorized into two groups: malformations and deformations. The malformations (n = 36) included hemifacial microsomia (n = 10), cleft lip and palate (n = 8), cleft palate (n = 4), rare facial cleft (n = 2), craniosynostosis (n = 2), Binder syndrome (n = 2), Treacher Collins syndrome (n = 2), craniopagus (n = 2), CHARGE association (n = 1), frontonasal dysplasia (n = 2), and constricted ears (n = 1). The deformations (n = 7) included plagiocephaly (n = 5), hemifacial hypoplasia (n = 1), and micrognathia (n = 1). Twenty-one monozygotic and 14 dizygotic twin pairs were identified. The concordance rate was 33 percent for monozygotic twins and 7 percent for dizygotic twins.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. 直流与交流电气线路中铜导线短路痕迹的分析%Analysis on short circuit trace of copper wire in direct and alternating current electric circuits

    Institute of Scientific and Technical Information of China (English)

    王连铁; 高伟; 赵长征; 袁晓光

    2012-01-01

    直流电气线路及交流电气线路中铜导线发生短路故障时所形成的熔痕的组织特征不同,为区分二者之间的差别,利用模拟试验手段制备出金相样品,并采用宏观分析、金相分析等各种技术手段进行分析总结,归纳出二者发生短路故障时所形成的痕迹特征规律.模拟研究结果表明,直流线路一次短路熔痕的金相组织以细小的柱状晶为主,且孔洞较少;在交流线路中,一次短路故障形成的熔痕的金相组织胞状晶较多,且交、直流电气线路中铜导线发生短路故障时所形成的熔痕的组织特征明显不同,这些特征可用于实际鉴定工作中.%The microstructural characteristics of melted marks formed due to the short circuit fault of copper wire in direct current(DC) and alternating current(AC) electric circuits are different.In order to distinguish the difference between them,the metallographic samples were prepared through the simulation tests.In addition,such technical means as macro analysis and metallographic analysis were used to analyze and summarize the characteristics of the mark formed due to the short circuit fault in DC and AC electric circuits.The simulation results show that the microstructures of melted marks formed due to the primary short circuit fault in DC circuit are mainly composed of fine columnar crystals with fewer holes.However,the microstructures of melted marks formed due to the primary short circuit fault in AC circuit contain more cellular crystals.Furthermore,the microstructural characteristics of melted marks formed due to the short circuit faults of copper wire in DC and AC electric circuits are obviously different,and can provide the reference for the actual identification work.

  7. Twin delivery: how should the second twin be delivered?

    Science.gov (United States)

    Olofsson, P; Rydhström, H

    1985-11-01

    In a series of 803 pairs of twins born between 1973 and 1982, 0.33% of second twins were delivered by cesarean section after vaginal delivery of the first twin. During the last year the frequency has increased to 7%, calling attention to the problem of declining obstetric skills and experience. This has caused us to update the routines of intrapartum management of twin gestations. In the present program only commonly available obstetric techniques are used. The potentially hazardous twin delivery is excluded from a trial of vaginal delivery. Hopefully, the program will help other obstetricians to decide in favor of vaginal delivery in selected twin gestations.

  8. Third NASA Workshop on Wiring for Space Applications

    Science.gov (United States)

    Hammoud, Ahmad (Compiler); Stavnes, Mark (Compiler)

    1995-01-01

    This workshop addressed key technology issues in the field of electrical power wiring for space applications, and transferred information and technology related to space wiring for use in government and commercial applications. Speakers from space agencies, U.S. Federal labs, industry, and academia presented program overviews and discussed topics on arc tracking phenomena, advancements in insulation materials and constructions, and new wiring system topologies.

  9. Effect of wire shape on wire array discharge

    Energy Technology Data Exchange (ETDEWEB)

    Shimomura, N.; Tanaka, Y.; Yushita, Y.; Nagata, M. [University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima (Japan); Teramoto, Y.; Katsuki, S.; Akiyama, H. [Kumamoto University, Department of Electrical and Computer Engineering, Kumamoto (Japan)

    2001-09-01

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  10. Experimental investigation and multi-objective optimization of wire electrical discharge machining (WEDM) of 5083 aluminum alloy%电火花线切割5083 Al合金的实验研究和参数优化

    Institute of Scientific and Technical Information of China (English)

    G. SELVAKUMAR; G. SORNALATHA; S. SARKAR; S. MITRA

    2014-01-01

    通过实验分析,优化电火花线切割5083 Al合金的工艺参数。基于Taguchi优化法,将脉宽、脉间、峰电流和线张力作为输入参数进行了系列实验。将表面粗糙度和切割速度作为响应,基于信噪比,测定了输入参数对响应的影响。通过Taguchi优化方法,得到了最大切割速度和最小表面粗糙度的最佳加工参数。再采用附加的模型预测可能的加工组合。最后,通过使用Pareto优化法,得到一个简明的工艺参数表。%The experimental analysis presented aims at the selection of the most optimal machining parameter combination for wire electrical discharge machining (WEDM) of 5083 aluminum alloy. Based on the Taguchi experimental design (L9 orthogonal array) method, a series of experiments were performed by considering pulse-on time, pulse-off time, peak current and wire tension as input parameters. The surface roughness and cutting speed were considered responses. Based on the signal-to-noise (S/N) ratio, the influence of the input parameters on the responses was determined. The optimal machining parameters setting for the maximum cutting speed and minimum surface roughness were found using Taguchi methodology. Then, additive model was employed for prediction of all (34) possible machining combinations. Finally, a handy technology table has been reported using Pareto optimality approach.

  11. Analyzing a Vibrating Wire Transducer using Coupled Resonator Circuits

    Directory of Open Access Journals (Sweden)

    POP, S.

    2015-08-01

    Full Text Available This paper intends to be an approach on the vibrating wire transducer from the perspective of the necessary rules used for a correct measurement procedure. There are several studies which analyze the vibrating wire transducer as a mechanical system. However, a comparative time-domain analysis between the mechanical and the electrical model is lacking. The transducer analysis is based on a theoretical analysis of the equivalent circuit, on both excitation and response time intervals. The electrical model consists of two magnetic coupled resonating circuits. When connected to an excitation source, there will be an energy transfer from the coil to the wire. The maximum energy transfer will occur at the vibrating wire's frequency of resonance. Using the transient regime analysis, it has been proven that, in the response time interval - when the wire vibrates freely, the current through the circuit that models the wire describes the oscillating movement of the wire. A complex signal is obtained, that contains both coil's and wire's frequencies of resonance, strongly dependent with theirs parasitic elements. The mathematical analysis highlights the similarity between mechanical and electrical model and the procedures in order to determine the wire frequency of resonance from the output signal.

  12. Highly stretchable wrinkled gold thin film wires

    Science.gov (United States)

    Kim, Joshua; Park, Sun-Jun; Nguyen, Thao; Chu, Michael; Pegan, Jonathan D.; Khine, Michelle

    2016-02-01

    With the growing prominence of wearable electronic technology, there is a need to improve the mechanical reliability of electronics for more demanding applications. Conductive wires represent a vital component present in all electronics. Unlike traditional planar and rigid electronics, these new wearable electrical components must conform to curvilinear surfaces, stretch with the body, and remain unobtrusive and low profile. In this paper, the piezoresistive response of shrink induced wrinkled gold thin films under strain demonstrates robust conductive performance in excess of 200% strain. Importantly, the wrinkled metallic thin films displayed negligible change in resistance of up to 100% strain. The wrinkled metallic wires exhibited consistent performance after repetitive strain. Importantly, these wrinkled thin films are inexpensive to fabricate and are compatible with roll to roll manufacturing processes. We propose that these wrinkled metal thin film wires are an attractive alternative to conventional wires for wearable applications.

  13. Highly stretchable wrinkled gold thin film wires

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joshua, E-mail: joshuk7@uci.edu; Park, Sun-Jun; Nguyen, Thao [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Chu, Michael [Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States); Pegan, Jonathan D. [Department of Materials and Manufacturing Technology, University of California, Irvine, California 92697 (United States); Khine, Michelle, E-mail: mkhine@uci.edu [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States)

    2016-02-08

    With the growing prominence of wearable electronic technology, there is a need to improve the mechanical reliability of electronics for more demanding applications. Conductive wires represent a vital component present in all electronics. Unlike traditional planar and rigid electronics, these new wearable electrical components must conform to curvilinear surfaces, stretch with the body, and remain unobtrusive and low profile. In this paper, the piezoresistive response of shrink induced wrinkled gold thin films under strain demonstrates robust conductive performance in excess of 200% strain. Importantly, the wrinkled metallic thin films displayed negligible change in resistance of up to 100% strain. The wrinkled metallic wires exhibited consistent performance after repetitive strain. Importantly, these wrinkled thin films are inexpensive to fabricate and are compatible with roll to roll manufacturing processes. We propose that these wrinkled metal thin film wires are an attractive alternative to conventional wires for wearable applications.

  14. Physarum wires: Self-growing self-repairing smart wires made from slime mould

    CERN Document Server

    Adamatzky, Andrew

    2013-01-01

    We report experimental laboratory studies on developing conductive pathways, or wires, using protoplasmic tubes of plasmodium of acellular slime mould Physarum polycephalum. Given two pins to be connected by a wire, we place a piece of slime mould on one pin and an attractant on another pin. Physarum propagates towards the attract and thus connects the pins with a protoplasmic tube. A protoplasmic tube is conductive, can survive substantial over-voltage and can be used to transfer electrical current to lightning and actuating devices. In experiments we show how to route Physarum wires with chemoattractants and electrical fields. We demonstrate that Physarum wire can be grown on almost bare breadboards and on top of electronic circuits. The Physarum wires can be insulated with a silicon oil without loss of functionality. We show that a Physarum wire self-heals: end of a cut wire merge together and restore the conductive pathway in several hours after being cut. Results presented will be used in future designs ...

  15. A KBE Application for Automatic Aircraft Wire Harness Routing

    NARCIS (Netherlands)

    Zhu, Z.; Van Tooren, M.J.L.; La Rocca, G.

    2012-01-01

    Wire harness design is an increasingly complex task. Knowledge Based Engineering (KBE) and optimization techniques can be used to support designers in handling this complexity. The wire harness design process can be divided in three main parts, namely electrical design, configuration design and geom

  16. Cooling method prolongs life of hot-wire transducer

    Science.gov (United States)

    Baldwin, L. V.; Sandborn, V. A.

    1964-01-01

    To cool a hot-wire transducer, the two ends of the wire are supported on thermally and electrically conductive rods, surrounded by a fluid cooling medium. By keeping the supporting rods at a substantially constant temperature, the probe is prevented from overheating.

  17. The Texas Twin Project.

    Science.gov (United States)

    Harden, K Paige; Tucker-Drob, Elliot M; Tackett, Jennifer L

    2013-02-01

    Socioeconomic position, racial/ethnic minority status, and other characteristics of the macro-environment may be important moderators of genetic influence on a wide array of psychosocial outcomes. Designed to maximize representation of low socioeconomic status families and racial/ethnic minorities, the Texas Twin Project is an ongoing study of school-age twins (preschool through 12th grade) enrolled in public schools in the Austin, Texas and Houston, Texas metropolitan areas. School rosters are used to identify twin families from a target population with sizable populations of African American (18%), Hispanic/Latino (48%), and non-Hispanic White (27%) children and adolescents, over half of whom meet US guidelines for classification as economically disadvantaged. Initial efforts have focused on a large-scale, family-based survey study involving both parent and child reports of personality, psychopathology, physical health, academic interests, parent-child relationships, and aspects of the home environment. In addition, the Texas Twin Project is the basis for an in-laboratory study of adolescent decision-making, delinquency, and substance use. Future directions include geographic expansion of the sample to the entire state of Texas (with a population of over 25 million) and genotyping of participating twins.

  18. Hypoalbuminemia in Donors with Twin-Twin Transfusion Syndrome

    NARCIS (Netherlands)

    Verbeek, L.; Middeldorp, J. M.; Hulzebos, C. V.; Oepkes, D.; Walther, F. J.; Lopriore, E.

    2013-01-01

    Objective: To estimate the differences in albumin levels between donors and recipients with twin-twin transfusion syndrome (TTTS). Methods: We performed a matched case-control study including twin pairs with TTTS treated conservatively (conservative group) or with fetoscopic laser surgery (laser gro

  19. 30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Science.gov (United States)

    2010-07-01

    ... wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802... Wires and Trolley Feeder Wires § 77.1802 Insulation of trolley wires, trolley feeder wires and bare..., and bare signal wires shall be adequately guarded: (a) At all points where men are required to work or...

  20. High conductivity carbon nanotube wires from radial densification and ionic doping

    Science.gov (United States)

    Alvarenga, Jack; Jarosz, Paul R.; Schauerman, Chris M.; Moses, Brian T.; Landi, Brian J.; Cress, Cory D.; Raffaelle, Ryne P.

    2010-11-01

    Application of drawing dies to radially densify sheets of carbon nanotubes (CNTs) into bulk wires has shown the ability to control electrical conductivity and wire density. Simultaneous use of KAuBr4 doping solution, during wire drawing, has led to an electrical conductivity in the CNT wire of 1.3×106 S/m. Temperature-dependent electrical measurements show that conduction is dominated by fluctuation-assisted tunneling, and introduction of KAuBr4 significantly reduces the tunneling barrier between individual nanotubes. Ultimately, the concomitant doping and densification process leads to closer packed CNTs and a reduced charge transfer barrier, resulting in enhanced bulk electrical conductivity.

  1. Mechanical and electrical evaluation of a dilute aluminium alloy heat treated for application in electrical cables and wires; Avaliacao mecanica e eletrica de uma liga diluida de aluminio tratada termicamente para aplicacao em fios e cabos eletricos

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, E.S. [Faculdade de Engenharia Mecanica - Unicamp - Campinas, SP (Brazil)], e-mail: manu@fem.unicamp.br; Kamizono, K.A.; Nogueira, P.; Nogueira, A.T.; Quaresma, Jose Maria do Vale [Universidade Federal do Para - UFPA, PA (Brazil)

    2010-07-01

    With the need to investigate new materials developed and presented to the market of non-ferrous materials and in particular those developed for the transmission and distribution of electricity, we conducted a study on a dilute alloy Al-EC-0, 7% Si, where from his previous characterization and thus knowing their good mechanical and electrical properties, we developed a new aluminum alloy in an attempt to know the properties of the alloy Al-EC-0, 7% Si in the presence of alloying elements, titanium. Being the new alloy under different thermal treatment temperature in order to observe their behavior under such mechanical and electrical conditions. (author)

  2. Recycling silicon wire-saw slurries: separation of silicon and silicon carbide in a ramp settling tank under an applied electrical field.

    Science.gov (United States)

    Tsai, Tzu-Hsuan; Shih, Yu-Pei; Wu, Yung-Fu

    2013-05-01

    The growing demand for silicon solar cells in the global market has greatly increased the amount of silicon sawing waste produced each year. Recycling kerf Si and SiC from sawing waste is an economical method to reduce this waste. This study reports the separation of Si and SiC using a ramp settling tank. As they settle in an electrical field, small Si particles with higher negative charges have a longer horizontal displacement than SiC particles in a solution of pH 7, resulting in the separation of Si and SiC. The agreement between experimental results and predicted results shows that the particles traveled a short distance to reach the collection port in the ramp tank. Consequently, the time required for tiny particles to hit the tank bottom decreased, and the interference caused by the dispersion between particles and the fluid motion during settling decreased. In the ramp tank, the highest purities of the collected SiC and Si powders were 95.2 and 7.01 wt%, respectively. Using a ramp tank, the recycling fraction of Si-rich powders (SiC electrical field. As they settle in an electrical field, small Si particles with higher negative charges have a longer horizontal displacement than SiC particles in a solution of pH 7, resulting in the separation of Si and SiC. Compared with the rectangular tanks, the recycling fraction of Si-rich powders using a ramp tank is greater, and the proposed ramp settling tank is more suitable for industrial applications.

  3. Dialysis for twins

    DEFF Research Database (Denmark)

    Gramkow, Ann-Maria; Aarup, Michael; Andersen, L. L. T.

    2014-01-01

    A 32-year-old woman with known stage-4 chronic kidney disease due to lupus nephritis presented with twin pregnancy after in vitro fertilization at a gestational age of 24 weeks + 3 days because of imminent preterm labour. Repeated ultrasound evaluations confirmed intrauterine growth restriction...... in both twins and polyhydramnios as the cause of imminent preterm labour. After initiation of haemodialysis treatment, ultrasound evaluation showed a significant decrease in amniotic fluids, and also reduction in blood urea nitrogen and in clinical complaints could be observed. At a gestational age of 28...... weeks + 4 days, delivery was performed by Caesarean section. This case study shows that effective treatment of elevated uraemic toxins significantly reduced the morbidity risks of the twins....

  4. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Christiansen, Lene; Kyvik, Kirsten Ohm;

    2013-01-01

    decade of combining questionnaire and survey data with national demographic, social, and health registers in Statistics Denmark. Second, we describe our most recent data collection effort, which was conducted during the period 2008-2011 and included both in-person assessments of 14,000+ twins born 1931......Over the last 60 years, the resources and the research in the Danish Twin Registry (DTR) have periodically been summarized. Here, we give a short overview of the DTR and a more comprehensive description of new developments in the twenty-first century. First, we outline our experience over the last......-1969 and sampling of biological material, hereby expanding and consolidating the DTR biobank. Third, two examples of intensively studied twin cohorts are given. The new developments in the DTR in the last decade have facilitated the ongoing research and laid the groundwork for new research directions....

  5. Inorganic Nanostructured High-Temperature Magnet Wires Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop a high-temperature tolerant electrically-insulating coating for magnet wires. The Phase I program will result in a flexible, inorganic...

  6. Vibrating wire alignment technique

    CERN Document Server

    Xiao-Long, Wang; lei, Wu; Chun-Hua, Li

    2013-01-01

    Vibrating wire alignment technique is a kind of method which through measuring the spatial distribution of magnetic field to do the alignment and it can achieve very high alignment accuracy. Vibrating wire alignment technique can be applied for magnet fiducialization and accelerator straight section components alignment, it is a necessary supplement for conventional alignment method. This article will systematically expound the international research achievements of vibrating wire alignment technique, including vibrating wire model analysis, system frequency calculation, wire sag calculation and the relation between wire amplitude and magnetic induction intensity. On the basis of model analysis this article will introduce the alignment method which based on magnetic field measurement and the alignment method which based on amplitude and phase measurement. Finally, some basic questions will be discussed and the solutions will be given.

  7. Maternal nutrition in twin pregnancy.

    Science.gov (United States)

    Campbell, D M; MacGillivray, I; Tuttle, S

    1982-01-01

    Energy and protein intake as measured by 24-hour urinary nitrogen values are similar in twin and singleton pregnancies. The relationship between urinary nitrogen and nitrogen intake is equally significant in twin and singleton pregnancies. Dietary zinc, copper, and iron are not different in women with twins, nor are the levels of these elements in plasma. These observations are surprising in view of the extra fetal demands on the mother and the different adaptation of twin pregnancies.

  8. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  9. Relativistic twins or sextuplets?

    CERN Document Server

    Sheldon, E S

    2003-01-01

    A recent study of the relativistic twin 'paradox' by Soni in this journal affirmed that 'A simple solution of the twin paradox also shows anomalous behaviour of rigidly connected distant clocks' but entailed a pedagogic hurdle which the present treatment aims to surmount. Two scenarios are presented: the first 'flight-plan' is akin to that depicted by Soni, with constant-velocity segments, while the second portrays an alternative mission undertaken with sustained acceleration and deceleration, illustrated quantitatively for a two-way spacecraft flight from Earth to Polaris (465.9 light years distant) and back.

  10. Imaging of conjoined twins

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kieran [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Kiely, Edward M.; Spitz, Lewis [Great Ormond Street Hospital for Children, Department of Surgery, London (United Kingdom)

    2006-09-15

    The incidence of conjoined twins is estimated to be around 1 in 250,000 live births. There is a distinct female predominance. In this paper the imaging of conjoined twins both antenatally and postnatally is reviewed, in particular taking into consideration recent advances with multidetector CT. Accurate counselling of parents regarding the likely outcome of the pregnancy and the likelihood of successful separation is dependent on good prenatal imaging with ultrasound and MRI. Planning of postnatal surgical separation is aided by accurate preoperative imaging which, depending on the conjoined area, will encompass many imaging modalities, but often relies heavily on CT scanning. (orig.)

  11. The Twin Interdisciplinary Neuroticism Study

    NARCIS (Netherlands)

    Riese, Harriette; Rijsdijk, Fruehling V.; Snieder, Harold; Ormel, Johan

    The Twin Interdisciplinary Neuroticism Study (TWINS) is a three-wave study including >800 twin pairs from the northern part of the Netherlands. The aim of the study is to unravel why neuroticism reflects vulnerability to mental disorders. In this study, we focus on possible mechanisms underlying

  12. 30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

    Science.gov (United States)

    2010-07-01

    ... power conductors and telephone wires. 75.521 Section 75.521 Mineral Resources MINE SAFETY AND HEALTH... Electrical Equipment-General § 75.521 Lightning arresters; ungrounded and exposed power conductors and telephone wires. Each ungrounded, exposed power conductor and each ungrounded, exposed telephone wire...

  13. 30 CFR 56.12066 - Guarding trolley wires and bare powerlines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guarding trolley wires and bare powerlines. 56... Electricity § 56.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded or deenergized. ...

  14. 30 CFR 57.12066 - Guarding trolley wires and bare powerlines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guarding trolley wires and bare powerlines. 57... MINES Electricity Surface Only § 57.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded...

  15. 30 CFR 77.515 - Bare signal or control wires; voltage.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal or control wires; voltage. 77.515... COAL MINES Electrical Equipment-General § 77.515 Bare signal or control wires; voltage. The voltage on bare signal or control wires accessible to personal contact shall not exceed 40 volts. ...

  16. Modelling of coil-loaded wire antenna using composite multiple domain basis functions

    CSIR Research Space (South Africa)

    Lysko, AA

    2010-03-01

    Full Text Available with electrically small features. The reduction in the number of unknowns is accomplished by a logical aggregation/grouping of the individual wire segments into equivalent continuous wires. A single composite basis function is applied over several wire segments...

  17. 30 CFR 77.508-1 - Lightning arresters; wires entering buildings.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lightning arresters; wires entering buildings... OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.508-1 Lightning arresters; wires entering buildings. Lightning arresters protecting exposed telephone wires entering buildings shall be provided...

  18. Photovoltaic Wire Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  19. On-Wire Lithography

    National Research Council Canada - National Science Library

    Lidong Qin; Sungho Park; Ling Huang; Chad A. Mirkin

    2005-01-01

    .... This procedure, termed on-wire lithography, combines advances in template-directed synthesis of nanowires with electrochemical deposition and wet-chemical etching and allows routine fabrication...

  20. 1998 wire development workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  1. Heat Transfer Analysis in Wire Bundles for Aerospace Vehicles

    Science.gov (United States)

    Rickman, S. L.; Iamello, C. J.

    2016-01-01

    Design of wiring for aerospace vehicles relies on an understanding of "ampacity" which refers to the current carrying capacity of wires, either, individually or in wire bundles. Designers rely on standards to derate allowable current flow to prevent exceedance of wire temperature limits due to resistive heat dissipation within the wires or wire bundles. These standards often add considerable margin and are based on empirical data. Commercial providers are taking an aggressive approach to wire sizing which challenges the conventional wisdom of the established standards. Thermal modelling of wire bundles may offer significant mass reduction in a system if the technique can be generalized to produce reliable temperature predictions for arbitrary bundle configurations. Thermal analysis has been applied to the problem of wire bundles wherein any or all of the wires within the bundle may carry current. Wire bundles present analytical challenges because the heat transfer path from conductors internal to the bundle is tortuous, relying on internal radiation and thermal interface conductance to move the heat from within the bundle to the external jacket where it can be carried away by convective and radiative heat transfer. The problem is further complicated by the dependence of wire electrical resistivity on temperature. Reduced heat transfer out of the bundle leads to higher conductor temperatures and, hence, increased resistive heat dissipation. Development of a generalized wire bundle thermal model is presented and compared with test data. The steady state heat balance for a single wire is derived and extended to the bundle configuration. The generalized model includes the effects of temperature varying resistance, internal radiation and thermal interface conductance, external radiation and temperature varying convective relief from the free surface. The sensitivity of the response to uncertainties in key model parameters is explored using Monte Carlo analysis.

  2. Design Scheme of Medium-speed Wire Cut Electrical Discharge Machining Workbench Feeding System%中走丝线切割机床工作台进给系统设计方案的研究

    Institute of Scientific and Technical Information of China (English)

    高荣; 罗刚; 胥宏; 陈勇; 杨章; 杨海

    2015-01-01

    在采用滚动直线导轨的基础上,对中走丝线切割机床DK7732的工作台进给系统进行了设计。根据机床工作台速度从静止加速至快速移动速度,为满足工作台性能的要求,对工作台进给系统电机转速、驱动扭矩、惯量匹配作了详细的计算。另外,对工作台滚珠丝杠螺母进给传动系统结构进行了设计和分析。%Adopting rolling linear guide, the workbench feeding system of the medium⁃speed wire cut electrical discharge machi⁃ning DK7732 was designed. According to the character of accelerating speed from motionless to the fast moving speed, to meet the re⁃quirements of workbench performance, the motor speed of workbench feeding system, driving torque, inertia matching were calculated in detail. On the other hand, the ball screw nut feeding drive system structure of the workbench was designed and analyzed.

  3. Thermal Model of a Current-Carrying Wire in a Vacuum

    Science.gov (United States)

    Border, James

    2006-01-01

    A computer program implements a thermal model of an insulated wire carrying electric current and surrounded by a vacuum. The model includes the effects of Joule heating, conduction of heat along the wire, and radiation of heat from the outer surface of the insulation on the wire. The model takes account of the temperature dependences of the thermal and electrical properties of the wire, the emissivity of the insulation, and the possibility that not only can temperature vary along the wire but, in addition, the ends of the wire can be thermally grounded at different temperatures. The resulting second-order differential equation for the steady-state temperature as a function of position along the wire is highly nonlinear. The wire is discretized along its length, and the equation is solved numerically by use of an iterative algorithm that utilizes a multidimensional version of the Newton-Raphson method.

  4. Second NASA Workshop on Wiring for Space Applications

    Science.gov (United States)

    1994-01-01

    This document contains the proceedings of the Second NASA Workshop on Wiring for Space Applications held at NASA LeRC in Cleveland, OH, 6-7 Oct. 1993. The workshop was sponsored by NASA Headquarters Code QW Office of Safety and Mission Quality, Technical Standards Division and hosted by NASA LeRC, Power Technology Division, Electrical Components and Systems Branch. The workshop addressed key technology issues in the field of electrical power wiring for space applications. Speakers from government, industry, and academia presented and discussed topics on arc tracking phenomena, wiring system design, insulation constructions, and system protection. Presentation materials provided by the various speakers are included in this document.

  5. Identical Twins Raised Apart

    Science.gov (United States)

    Farnsworth, David L.

    2015-01-01

    This article describes a bivariate data set that is interesting to students. Indeed, this particular data set, which involves twins and IQ, has sparked more student interest than any other set that I have presented. Specific uses of the data set are presented.

  6. Sleep Terrors in Twins

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-12-01

    Full Text Available In an attempt to clarify the genetic and environmental causes of sleep terrors in childhood, reasearchers in Canada followed 390 pairs of monozygotic and dizygotic twins by assessing the frequency of sleep terrors at 18 and 30 months of age using a questionnaire administered to the biological mothers.

  7. Twin Hub Network (poster)

    NARCIS (Netherlands)

    Kreutzberger, E.D.; Konings, J.W.

    2014-01-01

    Twin hub network, a European Interreg IVB project, aims at making intermodal rail transport within, to and from North West Europe more competitive, in particular between seaports and inland terminals. Improving rail competitiveness enables to shift freight flows from road to rail, providing a more s

  8. Amelia in Twin Pregnancy

    Directory of Open Access Journals (Sweden)

    Davari Tanha Fatemeh

    2009-04-01

    Full Text Available Limb bud first appears during the third week of gestation with the upper limb buds appearing a few days before the lower limb buds. Complete absence of one or more limbs, called Amelia, occurs prior to the eighth week of gestation. We report a case of Amelia in a twin gestation.

  9. TWIN BLOCK (Studi Pustaka

    Directory of Open Access Journals (Sweden)

    Evie Lamtiur

    2015-08-01

    Full Text Available Young patients with class II skeletal malocclusion are often found. To avoid further discrepancy of this case, myofunctional therapy is one of the options. Functional appliance often used for such treatment. Functional appliance has been modified since activator was introduced by Andresen. With its bulky shape, activator makes difficulty for patient to speak and eat. Patient unable to wear it full time due to uncomfortness and negative facial appearance. In 1977, Clark developed twin block to overcome the weakness of previous appliances. A more simple design allows patient to be more comfortable and willing to wear it longer. Twin block is myofunctional appliance to reposition the mandible forward for skeletal class II correction with retruded mandible. This paper describes the design, clinical management effects of twin block treatment and brief case presentation using twin block appliance. Similar to the study reports found, this case revealed improvement of facial appearance, decrease overjet and overbite, improvement of molar relationship and good compliance of patient.

  10. Twin-twin transfusion syndrome - diagnosis and prognosis

    Directory of Open Access Journals (Sweden)

    Hajrić-Egić Amira

    2003-01-01

    Full Text Available Twin-twin transfusion syndrome is a serious complication of monozygotic, monochorionic, diamniotic twins resulting from transplacental vascular communications. In this syndrome blood is thought to be shunted from one twin - donor,who develops anaemia,growth retardation and oligoamnios, to the other twin - recipient,who becomes plethoric,macrosomic and develops polyhydroamnios. The incidence of twin-twin transfusion syndrome ranges from 5-15% of all twin pregnancies. If this condition develops in the second trimester, it is usually associated with spontaneous abortion and death of one or both fetuses before viability. Developing the syndrome in the third trimester has better perinatal outcome. Mortality rates ranging from 56%-100%, depending on gestational age and severity of the syndrome. The ultrasound criterias for diagnosis, in this study,were the presence of twins of the same sex with discordant growth, with oligohydroamnios in one twin sac and polyhydroamnios in the other one, one placenta and thin membrane between twins. The present study shows clinical course of 14 cases and value of Doppler ultrasound to analyze the usefulness of umbilical artery blood flow velocimetry for predicting the risk of twin-twin transfusion syndrome. 14 twin pregnancies with twin-twin transfusion syndrome were diagnosed during the last four years period and prospectivelly followed. 9 cases were diagnosed before the completion od 28 weeks of gestation.The mean gestational age was 21,6_+4,2 weeks at diagnosis and 23,2+_3,6 weeks at delivery. 5 cases were diagnosed after 28 weeks of gestation. The mean gestational age in this group was 29,6+_2,1 weeks at diagnosis and 33+_3,3 weeks at delivery. The survival rate in this study was 29%(8/28.9 cases ended in spontaneous abortion between 18th and 27th weeks of pregnancy (table 1 and 5 in premature labor (table 2.There were 7 intrauterine death (5 at admission and 2 few days after admission and 13 neonatal deaths

  11. Developing Process of Negative Creeping Discharge along Aerial Insulated Wire

    Science.gov (United States)

    Nishi, Toshiyuki; Hanaoka, Ryoichi; Takata, Shinzo

    When a lightning occurs at the neighborhood of high voltage aerial distribution lines, the overvoltage due to the inductive lightning surge invades to the central line of the insulated wire. Because of the insulated wire is supported by the insulator and the binding wire at the electric light pole, the creeping discharges develop along the wire surface from the free end of the binding wire, just after a flashover of the insulator at the wire supporting point. These creeping discharges give rise to the disaster near the wire supporting point including the punch-through breakdown of wire when the weak points such as pin-holes exist in the wire insulator. To prevent these accidents, it is important to understand the behavior of creeping discharges at the insulated wire surface originating in the lightning strike. Positive and negative creeping discharges reveal the distinctive aspect by the polarities of the inductive lightning surges. In the previous paper, we have clarified the developing process of positive creeping discharge based on the data obtained from an image converter camera. In this paper, we report the developing process of negative creeping discharge. Complicated behavior of negative creeping discharge is clarified using an image converter camera and its process is discussed.

  12. Temperature effect on DNA molecular wires

    Science.gov (United States)

    Bui, Christopher Minh

    The demand of technology and information today has further pushed the fabrication process of nanotechnology, yet there are limits and obstacles set by the primary laws of physics. Therefore, researchers are pursuing alternative technologies. Deoxyribonucleic acids (DNA) molecular wire is one advantageous option due to its unique characteristics including self-assembly and naturally small; size. This thesis reports the temperature effect on the electrical properties of a double-stranded ?-DNA molecular wire. The data will help expand the DNA wire application and functionality. Thus, the data supports the charge hopping theory on DNA electrical conductivity. Diverse amount of literatures has demonstrated that DNA experiences a biochemical alteration when exposed under different temperature conditions. This change will also cause a change in the electrical properties. In this research, DNA will hang between two gold covered microelectrodes with a distance of 10 to 12 microns. The microelectrodes are fabricated through negative lithography techniques. Then, the samples were exposed to a numerous range of temperature from 25°C to 180°C and went through varying cycles of heating and cooling. The experimental results revealed that the DNA experienced a hysteresis like behavior where the impedance differed between the heating and cooling phase. The impedance of the DNA molecular wire increased when exposed to higher temperature. Furthermore, the impedance stops increasing after a certain amount of heat cycles before the DNA structure failed. The biology and thermodynamics of the DNA wire was analyzed due to the temperature hysteresis effect. The melting temperature and the bond dissociation temperature were evaluated to determine the cause of the impedance trends. The studies and analysis of the temperature effect provided certain insights towards the charge hopping transport mechanism. The thesis concludes with possible applications relating to the temperature effect of

  13. Mitral valve regurgitation in twins

    DEFF Research Database (Denmark)

    Bakkestrøm, Rine; Larsen, Lisbeth Aagaard; Møller, Jacob Eifer

    2016-01-01

    BACKGROUND: Smaller observational studies have suggested familial clustering of mitral regurgitation (MR). Using a large twin cohort, the aims were to assess MR concordance rates and assess mortality in MR twins and unaffected cotwins. METHODS: Through the Danish Twin Registry, twins...... with an International Classification of Diseases, Eighth Revision and Tenth Revision diagnosis code of MR born 1880-1989 were identified and proband-wise concordance rates were calculated. To assess whether having a cotwin with MR affected survival, 10 matched twins without MR (n = 5,575) were selected for each MR twin...... (n = 562), and all-cause mortality rates were assessed. RESULTS: Among the 87,432 twins alive January 1, 1977, or later, 494 (0.57%) MR individuals were identified. Six MR concordant pairs were found, of which 3 were monozygotic. Proband-wise concordance rate when accounting for right censoring...

  14. Fabrication of Wire Mesh Heat Exchangers for Waste Heat Recovery Using Wire-Arc Spraying

    Science.gov (United States)

    Rezaey, R.; Salavati, S.; Pershin, L.; Coyle, T.; Chandra, S.; Mostaghimi, J.

    2014-04-01

    Waste heat can be recovered from hot combustion gases using water-cooled heat exchangers. Adding fins to the external surfaces of the water pipes inserted into the hot gases increases their surface area and enhances heat transfer, increasing the efficiency of heat recovery. A method of increasing the heat transfer surface area has been developed using a twin wire-arc thermal spray system to generate a dense, high-strength coating that bonds wire mesh to the outside surfaces of stainless steel pipes through which water passes. At the optimum spray distance of 150 mm, the oxide content, coating porosity, and the adhesion strength of the coating were measured to be 7%, 2%, and 24 MPa, respectively. Experiments were done in which heat exchangers were placed inside a high-temperature oven with temperature varying from 300 to 900 °C. Several different heat exchanger designs were tested to estimate the total heat transfer in each case. The efficiency of heat transfer was found to depend strongly on the quality of the bond between the wire meshes and pipes and the size of openings in the wire mesh.

  15. [Study of a wire-to-plate positive pulsed corona discharge reactor by emission spectroscopy].

    Science.gov (United States)

    Wang, Shen-Bing; Luo, Zhong-Yang; Zhao, Lei; Xuan, Jian-Yong; Jiang, Jian-Ping; Cen, Ke-Fa

    2011-11-01

    In order to get extensive knowledge of wire-to-plate pulsed corona discharge reactor, the influences of different diameters of wire electrode, different wire-to-plate and wire-to-wire spacing on OH radical generation were experimentally investigated under atmospheric pressure based on emission spectrum, and the spatial distribution of OH radicals in the electric field was also discussed in detail The results showed that OH radicals decrease along the X-axis, and the activation radius is approximately 20 mm; showing a trend of first increase and then decrease along the Y-axis, with the activation radius being more than 30 mm. OH radical has small change as the diameter of wire electrode changes below 2 mm, with a sharp decline as the diameter continues to increase. OH radical emission intensity increases as wire-to-wire spacing increases and decrease as wire-to-plate spacing increases.

  16. Sidewall morphology-dependent formation of multiple twins in Si nanowires.

    Science.gov (United States)

    Shin, Naechul; Chi, Miaofang; Filler, Michael A

    2013-09-24

    Precise placement of twin boundaries and stacking faults promises new opportunities to fundamentally manipulate the optical, electrical, and thermal properties of semiconductor nanowires. Here we report on the appearance of consecutive twin boundaries in Si nanowires and show that sidewall morphology governs their spacing. Detailed electron microscopy analysis reveals that thin {111} sidewall facets, which elongate following the first twin boundary (TB1), are responsible for deforming the triple-phase line and favoring the formation of the second twin boundary (TB2). While multiple, geometrically correlated defect planes are known in group III-V nanowires, our findings show that this behavior is also possible in group IV materials.

  17. Brazilian Twin Registry: A Bright Future for Twin Studies/Twin Research: Twin Study of Alcohol Consumption and Mortality; Oxygen Uptake in Adolescent Twins/In the News: Superfecundated Twins In Vietnam; Adolescent Twin Relations; Twin and Triplet Co-Workers; A Special Twin Ultrasound; Monozygotic Twins With Different Skin Color; Identical Twin Returns from Space.

    Science.gov (United States)

    Segal, Nancy L

    2016-06-01

    The establishment of the Brazilian Twin Registry for the study of genetic, social, and cultural influences on behavior is one of eleven newly funded projects in the Department of Psychology at the University of São Paulo. These 11 interrelated projects form the core of the university's Center for Applied Research on Well-Being and Human Behavior. An overview of the planned twin research and activities to date is presented. Next, two recent twin studies are reviewed, one on the relationship between alcohol consumption and mortality, and the other on factors affecting maximal oxygen uptake. Twins cited in the media include the first identified superfecundated twins in Vietnam, adolescent twin relations, twins and triplets who work together, monozygotic twins with different skin tones and a co-twin control study that addresses the effects of space travel.

  18. Recrystallization and Grain Growth of 316L Stainless Steel Wires

    Science.gov (United States)

    Zhao, Xiuyun; Liu, Yong; Wang, Yan; Feng, Ping; Tang, Huiping

    2014-07-01

    Recrystallization and grain growth behaviors of 316L stainless steel wires with a diameter of 12 µm were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy (TEM), and X-ray diffraction techniques. Heavily cold-drawn wires were isothermally held at temperatures from 1073 K to 1223 K (800 °C to 950 °C) for various holding times. Optical microscopy and TEM observations showed that recrystallization grains have irregular shape and that twins exist. The texture formed during drawing and annealing processes of the wires, as measured by X-ray methods, showed a fiber texture approximated by a and a component. The value of the grain growth exponent n was calculated, and the kinetic rates were plotted using the Arrhenius equation. Results show that the activation energy of the grain growth for 316L stainless steel wire was determined to be 407 kJ/mol, which was much higher than that of the bulk 316L stainless steel. The small wire diameter and the existence of texture played important roles in the increase of the activation energy for grain growth of the wire.

  19. 线切割加工质量的分析及改善措施%Analysis and improvement for wire-cutting electrical discharge machining

    Institute of Scientific and Technical Information of China (English)

    魏妍丽

    2015-01-01

    线切割加工在模具制造业中常用于加工精密、微细的模具零件。通过介绍线切割的加工原理,研究了线切割加工过程容易产生的加工质量缺陷,分析了加工面变形与开裂、变质层及表面粗糙度产生的原因,提出了进一步提高工件表面质量的改善措施和方法。实践中可以通过合理选材、优化电参数、选择正确的加工路线等方面综合分析和控制线切割加工,在保证生产率的前提下,改善和提高线切割加工质量。%Wire‐cutting electrical discharge machining is commonly used in the precision and micro‐parts machining process for the mould .Through the introduction of wire‐cutting ma‐chining principle ,the processing defects during wire‐cutting machining are analyzed ,such as the deformation and cracking on the machined surface ,the generation of metamorphic layer and rough surface .Some measures are also proposed to improve the surface quality . Practice proves that appropriate materials , optimal discharge parameters and reasonable cutting paths can improve the machining quality .

  20. Body of Knowledge (BOK) for Copper Wire Bonds

    Science.gov (United States)

    Rutkowski, E.; Sampson, M. J.

    2015-01-01

    Copper wire bonds have replaced gold wire bonds in the majority of commercial semiconductor devices for the latest technology nodes. Although economics has been the driving mechanism to lower semiconductor packaging costs for a savings of about 20% by replacing gold wire bonds with copper, copper also has materials property advantages over gold. When compared to gold, copper has approximately: 25% lower electrical resistivity, 30% higher thermal conductivity, 75% higher tensile strength and 45% higher modulus of elasticity. Copper wire bonds on aluminum bond pads are also more mechanically robust over time and elevated temperature due to the slower intermetallic formation rate - approximately 1/100th that of the gold to aluminum intermetallic formation rate. However, there are significant tradeoffs with copper wire bonding - copper has twice the hardness of gold which results in a narrower bonding manufacturing process window and requires that the semiconductor companies design more mechanically rigid bonding pads to prevent cratering to both the bond pad and underlying chip structure. Furthermore, copper is significantly more prone to corrosion issues. The semiconductor packaging industry has responded to this corrosion concern by creating a palladium coated copper bonding wire, which is more corrosion resistant than pure copper bonding wire. Also, the selection of the device molding compound is critical because use of environmentally friendly green compounds can result in internal CTE (Coefficient of Thermal Expansion) mismatches with the copper wire bonds that can eventually lead to device failures during thermal cycling. Despite the difficult problems associated with the changeover to copper bonding wire, there are billions of copper wire bonded devices delivered annually to customers. It is noteworthy that Texas Instruments announced in October of 2014 that they are shipping microcircuits containing copper wire bonds for safety critical automotive applications

  1. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    2009-01-01

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  2. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  3. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    2009-01-01

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  4. Reared-Apart Chinese Twins: Chance Discovery/Twin-Based Research: Twin Study of Media Use; Twin Relations Over the Life Span; Breast-Feeding Opposite-Sex Twins/Print and Online Media: Twins in Fashion; Second Twin Pair Born to Tennis Star; Twin Primes; Twin Pandas.

    Science.gov (United States)

    Segal, Nancy L

    2017-04-01

    A January 2017 reunion of 10-year-old reared-apart Chinese twin girls was captured live on ABC's morning talk show Good Morning America, and rebroadcast on their evening news program Nightline. The twins' similarities and differences, and their participation in ongoing research will be described. This story is followed by reviews of twin research concerning genetic and environmental influences on media use, twin relations across the lifespan and the breast-feeding of opposite-sex twins. Popular interest items include twins in fashion, the second twin pair born to an internationally renowned tennis star, twin primes and twin pandas.

  5. Induced voltage in an open wire

    CERN Document Server

    Morawetz, K; Trupp, A

    2015-01-01

    A puzzle arising from Faraday's law is considered and solved concerning the question which voltage is induced in an open wire feeling a time-varying homogeneous magnetic field. The longitudinal electric field contributes 1/3 and the transverse field 2/3 to the induced voltage. The representation of a homogeneous and time-varying magnetic field implies unavoidably a certain symmetry point or line dependent on the geometry of the source. As a consequence the induced voltage of an open wire is found to be the area covered with respect to the symmetry line or point perpendicular to the magnetic field. This in turn allows to find the symmetry points of a magnetic field source by measuring the voltage of an open wire. We present two exactly solvable models for a symmetry point and for a symmetry line. The results are applicable to open circuit problems and for astrophysical applications.

  6. Reusable Hot-Wire Cable Cutter

    Science.gov (United States)

    Pauken, Michael T.; Steinkraus, Joel M.

    2010-01-01

    During the early development stage of balloon deployment systems for missions, nichrome wire cable cutters were often used in place of pyro-actuated cutters. Typically, a nichrome wire is wrapped around a bundle of polymer cables with a low melting point and connected to a relay-actuated electric circuit. The heat from the nichrome reduces the strength of the cable bundle, which quickly breaks under a mechanical load and can thus be used as a release mechanism for a deployment system. However, the use of hand-made heated nichrome wire for cutters is not very reliable. Often, the wrapped nichrome wire does not cut through the cable because it either pulls away from its power source or does not stay in contact with the cable being cut. Because nichrome is not readily soldered to copper wire, unreliable mechanical crimps are often made to connect the nichrome to an electric circuit. A self-contained device that is reusable and reliable was developed to sever cables for device release or deployment. The nichrome wire in this new device is housed within an enclosure to prevent it from being damaged by handling. The electric power leads are internally connected within the unit to the nichrome wire using a screw terminal connection. A bayonet plug, a quick and secure method of connecting the cutter to the power source, is used to connect the cutter to the power leads similar to those used in pyro-cutter devices. A small ceramic tube [0.25-in. wide 0.5-in. long (.6.4-mm wide 13-mm long)] houses a spiraled nichrome wire that is heated when a cable release action is required. The wire is formed into a spiral coil by wrapping it around a mandrel. It is then laid inside the ceramic tube so that it fits closely to the inner surface of the tube. The ceramic tube provides some thermal and electrical insulation so that most of the heat generated by the wire is directed toward the cable bundle in the center of the spiral. The ceramic tube is cemented into an aluminum block, which

  7. Minimal Mirror Twin Higgs

    CERN Document Server

    Barbieri, Riccardo; Harigaya, Keisuke

    2016-01-01

    In a Mirror Twin World with a maximally symmetric Higgs sector the little hierarchy of the Standard Model can be significantly mitigated, perhaps displacing the cutoff scale above the LHC reach. We show that consistency with observations requires that the Z2 parity exchanging the Standard Model with its mirror be broken in the Yukawa couplings. A minimal such effective field theory, with this sole Z2 breaking, can generate the Z2 breaking in the Higgs sector necessary for the Twin Higgs mechanism, and has constrained and correlated signals in invisible Higgs decays, direct Dark Matter Detection and Dark Radiation, all within reach of foreseen experiments. For dark matter, both mirror neutrons and a variety of self-interacting mirror atoms are considered. Neutrino mass signals and the effects of a possible additional Z2 breaking from the vacuum expectation values of B-L breaking fields are also discussed.

  8. Transparent electric convection heater

    OpenAIRE

    Khalid, A.; Luck, J.L.

    2001-01-01

    An optically transparent electrically heated convection heater for use as a space heater in homes, offices, shops. Typically, said convection heater consists of a transparent layer 1 upon which is deposited a layer of a transparent electrically conductive material 2 such as indium-tin-oxide, electrodes 3 and 3a are formed on opposite edges of the transparent electrically conductive layer 2 and electrical wires 4 and 4a are connected to the electrodes. The transparent electrically conductive l...

  9. Emergence of Digital Twins

    OpenAIRE

    Datta, Shoumen Palit Austin

    2016-01-01

    Multiple forms of digital transformation are imminent. Digital Twins represent one concept. It is gaining momentum because it may offer real-time transparency. Rapid diffusion of digital duplicates faces hurdles due to lack of semantic interoperability between architectures, standards and ontologies. The technologies necessary for automated discovery are in short supply. Progression of the field depends on convergence of information technology, operational technology and protocol-agnostic tel...

  10. Nutrition in twin pregnancy.

    Science.gov (United States)

    MacGillivray, I

    1979-01-01

    The urinary nitrogen output appears to be related to both protein and energy intake, so that women having heavier babies probably eat more, although this may simply mean that they are larger women. Women with twin pregnancies have been found to have a lesser urinary nitrogen output, but it seems unlikely that this be due to lower intakes. They might simply utilize their diet more efficiently--a hypothesis that is now being tested.

  11. The Safety Inspection of Steel Wire Rope Electric Block for Hoisting and Conveying Melt Metal%吊运熔融金属的钢丝绳电动葫芦的安全检验

    Institute of Scientific and Technical Information of China (English)

    卜广强

    2011-01-01

    吊运熔融金属的钢丝绳电动葫芦安全事故苗头险象丛生,安全检验的要求和内容散见于相关法规、规范和标准,由于颁布实施时间和执行效力的不同,且存在一定的差异,给检验判定尺度的准确掌握增加了不小的难度.作者通过研究关于吊运熔融金属起重机的法规、规范和标准,结合工厂实际使用的该类电动葫芦安全现状以及相关检验经验,对吊运熔融金属的钢丝绳电动葫芦安全检验项目的设置、内容与要求、结论判定等方面提出了自己的理解,供相关单位和人员参考.%With investigation on rule of law, technical specifications and standards of crane to hoist and convey melt metal, combined with the status que of safety and corresponding inspection experiences with such crane practical service in foundries, the sectors such as setting, content and requirement, conclusion judgement on the items of safety inspection for steel wire rope electric block of hoisting and conveying melt metal have been expressed with own point of view for reference to corresponding units and personnel.

  12. Tribute to dr louis keith: twin and physician extraordinaire/twin research reports: influences on asthma severity; chimerism revisited; DNA strand break repair/media reports: twins born apart; elevated twin frequencies; celebrity father of twins; conjoined twinning.

    Science.gov (United States)

    Segal, Nancy L

    2014-10-01

    The International Society for Twin Studies has lost a valued friend and colleague. Dr Louis Keith, Emeritus Professor of Obstetrics and Gynecology at Northwestern University, in Chicago, passed away on Sunday, July 6, 2014. His life and work with twins will be acknowledged at the November 2014 International Twin Congress in Budapest, Hungary. Next, twin research reports on the severity of asthma symptoms, a case of chimerism, and factors affecting DNA breakage and repair mechanisms are reviewed. Media reports cover twins born apart, elevated twin frequencies, a celebrity father of twins, and a family's decision to keep conjoined twins together.

  13. Socioeconomic position and twins' health

    DEFF Research Database (Denmark)

    Osler, Merete; McGue, Matt; Christensen, Kaare

    2007-01-01

    of middle-aged Danish twins was conducted in 1998-99. The study population included 1266 like-sex twin pairs [52.5% monozygotic (MZ) and 47.6% dizygotic (DZ)]. Data were obtained on childhood and adult social class and on height, BMI, grip strength, depression symptoms, self-rated health, cognitive function......, prenatal and rearing environmental factors from environmental factor later in life, we compared the health status among male and female twin pairs who lived together during childhood and were discordant or concordant on adult socioeconomic position. METHODS: A cross-sectional survey among a random sample......, physical activity, smoking, alcohol and food intake. RESULTS: The expected associations between the individual twins' adult social class and health measures were observed. Among DZ male twins discordant on adult social class, the higher social class twin was on average significantly taller and had higher...

  14. Design and control of a Nitinol wire actuated rotary servo

    Science.gov (United States)

    Song, G.

    2007-10-01

    This paper presents the design and control of a rotary servo actuated by a shape memory alloy (SMA) wire. A new rotary servo device using Nitinol type of SMA wire is designed and fabricated in this study. This new rotary actuator utilizes a Nitinol wire wound on a threaded non-conductive rotor. One end of the Nitinol wire is fixed to the rotor and the other end is fixed to the supporting base plate. The rotor is connected to a pre-tensioned torsional spring such that two-way rotation can be achieved. Upon heating of the Nitinol wire using electric current, the wire contracts, causing the rotor to rotate, since the other end of the SMA wire is rigidly connected to the base plate. This rotor design is compact and offers a space-saving solution for the use of SMA wire actuators. To actively control the servo, a sliding-mode based robust control approach is used. The sliding-mode based robust control consists of three components: a standard proportional plus derivative (PD) control term, a feedforward term used as a bias current, and a robust term to increase system stability and concurrently control accuracy. Experimental results confirm the functionality of the Nitinol wire actuated rotary servo and show this device can be precisely controlled using the sliding-mode based robust control approach.

  15. Twin-to-twin delivery time: neonatal outcome of the second twin.

    Science.gov (United States)

    Schneuber, Susanne; Magnet, Eva; Haas, Josef; Giuliani, Albrecht; Freidl, Thomas; Lang, Uwe; Bjelic-Radisic, Vesna

    2011-12-01

    To examine the effect of twin-to-twin delivery time (TTDT) on neonatal outcome. We evaluated twin deliveries >34 weeks of gestation. Twin pregnancies with both twins delivered by cesarean section and pregnancies with antenatal complications were excluded. We analyzed TTDT and neonatal outcomes of the second twin (umbilical arterial pH value (pH(art)), Apgar scores at 1, 5 and 10 minutes, need for intensive care). The study population was divided into two homogenous groups based on the mode of delivery: (A) vertex presentation and vaginal delivery of both twins, (B) vertex presentation and vaginal or vaginal operative delivery of twin I, breech or transverse presentation and vaginal breech delivery or cesarean section (CS) of twin II. A total of 207 twin pairs were included in our study. In Group A (n = 151) there were no significant correlations between TTDT and pH(art) or Apgar scores at 1,5 and 10 minutes of twin II (p = .156; 0.861; 0.151 and 0.384, respectively). In Group B (n = 56), the mean pH(art) of twin II was inversely correlated to TTDT, but not significantly (p = .417). TTDT was inversely related to 1-min and 5-min Apgar scores, but not significantly (p = .330; p = .138, respectively). The 10-min Apgar score showed no correlation with TTDT (p = .638). Increasing TTDT was not associated with adverse fetal outcome. Expectant management of the second twin appears possible and elapsed time alone does not appear to be an indication for intervention.

  16. Simulations of Twin-Box Joints for ITER PF Coils

    NARCIS (Netherlands)

    Ilyin, Y.; Rolando, G.; Nijhuis, A.; Simon, F.; Lim, B.S.; Mitchell, N.; Turck, B.

    2014-01-01

    An ITER Poloidal Field coil winding consists of stacked double pancakes wound with NbTi cable-in-conduit conductors. One of the critical components of the coil is the electrical joint connecting either two conductor lengths within a double pancake or two double pancakes. All joints utilize the twin-

  17. Optimal welding of beta titanium orthodontic wires.

    Science.gov (United States)

    Nelson, K R; Burstone, C J; Goldberg, A J

    1987-09-01

    Today the orthodontist is confronted by an array of new orthodontic wire materials that, when applied to appliance design, can vastly increase the flexibility and versatility of therapy. Welded joints, especially for the newer titanium alloy wires, provide a means to extend the useful applications of these materials. The purpose of this study was to determine the optimum settings for electrical resistance welding of various configurations of titanium-molybdenum (TMA) wires. Specimens were of a t-joint configuration and were mechanically tested in torsion to simulate the failure mode most often observed in clinical practice. Variables included wire size, wire orientation, and welding voltage. Results indicated that excellent welds can be obtained with very little loss of strength and ductility in the area of the weld joint. Torsional loads at failure were at least 90% of the unwelded base material. Although a wide range of voltage settings resulted in high-strength welds, typically a narrow range of voltages yielded optimal ductility.

  18. Trojan twin planets

    Science.gov (United States)

    Dvorak, R.; Loibnegger, B.; Schwarz, R.

    2017-03-01

    The Trojan asteroids are moving in the vicinity of the stable Lagrange points L_4 and L_5 of the gas giants Jupiter, Uranus and Neptune. Their motion can be described and understood with the aid of the restricted three-body problem. As an extension of this problem we investigate how stable motion close to the Lagrange points of two massive bodies can exist. This configuration can be described as the Trojan Twin Problem when we regard the two additional bodies as having a mass significantly smaller than the the two primary bodies: a star in the center (m_1) and an additional Jupiter-like mass (m_2). Using this 4-body problem we have undertaken numerical investigations concerning possible stable "twin orbits". However, these two bodies (m_3 and m_4) in Trojan-like orbits may have quite different masses. We decided to choose 6 different scenaria for this problem: as primary body, m2, we have taken a Jupiter-like planet, a Saturn-like one, and a super-Earth with 10 Earthmasses (m_{Earth}) respectively. As quasi twin planets, we have used different mass ratios namely objects for m3 and m4 from 10m_{Earth} to Moon like ones. We found different stable configurations depending on the involved masses and the initial distances between the twins (always close to the Lagrange point). Although the formation of such a configuration seems to be not very probable we should not exclude that it exists regarding the huge number of planets even in our own galaxy. This model is of special interest when the most massive planet (m_2) is moving on an orbit in the habitable zone around a main sequence star. One can use our results of stable orbits of Trojan Twin Planets (or asteroids) for extrasolar systems having as second primary a Jupiter-like, a Saturn-like or a super-Earth like planet around a star similar to our Sun.

  19. The flavor of the Composite Twin Higgs

    Science.gov (United States)

    Csáki, Csaba; Geller, Michael; Telem, Ofri; Weiler, Andreas

    2016-09-01

    The assumption of anarchic quark flavor puts serious stress on composite Higgs models: flavor bounds imply a tuning of a few per-mille (at best) in the Higgs potential. Composite twin Higgs (CTH) models significantly reduce this tension by opening up a new region of parameter space, obtained by raising the coupling among the composites close to the strong coupling limit g ∗ ˜ 4π, thereby raising the scale of composites to around 10 TeV. This does not lead to large tuning in the Higgs potential since the leading quantum corrections are canceled by the twin partners (rather than the composites). We survey the leading flavor bounds on the CTH, which correspond to tree-level Δ F = 2 four-Fermi operators from Kaluza-Klein (KK) Z exchange in the kaon system and 1-loop corrections from KK fermions to the electric dipole moment of the neutron. We provide a parametric estimate for these bounds and also perform a numeric scan of the parameter space using the complete calculation for both quantities. The results confirm our expectation that CTH models accommodate anarchic flavor significantly better than regular composite Higgs (CH) models. Our conclusions apply both to the identical and fraternal twin cases.

  20. When You Are a Twin or Triplet

    Science.gov (United States)

    ... be a twin? Are you a twin and wonder why everyone thinks it's so special? It's fascinating ... the way the egg is fertilized when a woman becomes pregnant . In fraternal twins, two different eggs ...

  1. Effect of the Circuit and Wire Parameters on Exploding an Al Wire in Water%Effect of the Circuit and Wire Parameters on Exploding an Al Wire in Water

    Institute of Scientific and Technical Information of China (English)

    周庆; 张乔根; 张俊; 赵军平; 任保忠; 庞磊

    2011-01-01

    The underwater electrical explosion of an aluminum wire is influenced by many factors, such as wire parameters, pulsed power energy, etc. In this paper, underwater electrical explosion of an aluminum wire was investigated with pulsed voltage in the time scale of a few microseconds. A self-integrated Rogowski coil and a voltage divider were used for the measurements of current and voltage at the wire load, respectively. The deposited energy before breakdown was calculated based on experimental waveforms of current and voltage by mathematical method. Effects of the applied voltage, circuit inductance and sion and energy deposition were analyzed by means parameters of Al wire on the electrical exploof experiments and calculation. The results show that the current rise rate has an important influence on explosion process, such as the energy deposition before breakdown, the electrical power as well as the various explosion stages. A higher current rise rate can be achieved by increasing applied voltage and decreasing circuit inductance. The inhomogeneity of the energy deposition will result in prematured breakdown as well as lowered energy deposition, making the explosion process of wire more complicated.

  2. Cavitation during wire brushing

    Science.gov (United States)

    Li, Bo; Zou, Jun; Ji, Chen

    2016-11-01

    In our daily life, brush is often used to scrub the surface of objects, for example, teeth, pots, shoes, pool, etc. And cleaning rust and stripping paint are accomplished using wire brush. Wire brushes also can be used to clean the teeth for large animals, such as horses, crocodiles. By observing brushing process in water, we capture the cavitation phenomenon on the track of moving brush wire. It shows that the cavitation also can affect the surface. In order to take clear and entire pictures of cavity, a simplified model of one stainless steel wire brushing a boss is adopted in our experiment. A transparent organic tank filled with deionized water is used as a view box. And a high speed video camera is used to record the sequences. In experiment, ambient pressure is atmospheric pressure and deionized water temperature is kept at home temperature. An obvious beautiful flabellate cavity zone appears behind the moving steel wire. The fluctuation of pressure near cavity is recorded by a hydrophone. More movies and pictures are used to show the behaviors of cavitation bubble following a restoring wire. Beautiful tracking cavitation bubble cluster is captured and recorded to show.

  3. Study on a wire grasping system for construction works in the electric supply utilizing a visual feedback technique. Visual feedback shuho-wo riyoshita haidensen koji ni okeru densen haaku system ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, T.; Eto, J.; Zhang, H.; Kimuro, Y.; Okada, N. (Kyushu University, Fukuoka (Japan). Faculty of Engineering); Yuki, M. (The Kyushu Electric Power Co. Inc., Fukuoka (Japan))

    1992-01-30

    Report is made of an automatic wire grasping system studied by applying an image processing method to it. Together with its concept and aspect, explanation is made of a method to process the image in each of the manual mode and auto mide, and control the manipulator. From a small CCD camera fitted to the finger end of manipulator, the image information is put in the computer through an image processor. The locative determination for the wire to be grasped can have the manipulator automatically shifted and located proper to grasp the wire. For the image processing in the auto mode, a linear equation was automatically detected of objective wire as per the image data put therein. Though experimentally fitted at the finger end of manipulator, the CCD camera requires a fitting of fiberscope at its end or other engineered method to take the image data therein against the insulation properties on the site. 4 refs., 16 figs.

  4. Contemporary management of complicated monochorionic twins.

    Science.gov (United States)

    Moise, Karen Y; Kugler, Lisa; Jones, Tyra

    2012-01-01

    Monochorionic twins are at increased risk for unique complications including twin-twin transfusion syndrome (TTTS), selective intrauterine growth restriction (sIUGR), and twin-reversed arterial perfusion (TRAP) sequence. Twin-twin transfusion syndrome is treated with laser photocoagulation whereas selective reduction is an option in previable sIUGR or TRAP sequence. The nurse is integral in the management, education, care and support of women with complicated pregnancies. © 2012 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  5. Controlled electromigration and oxidation of free-standing copper wires

    Science.gov (United States)

    Hauser, J. S.; Schwichtenberg, J.; Marz, M.; Sürgers, C.; Seiler, A.; Gerhards, U.; Messerschmidt, F.; Hensel, A.; Dittmeyer, R.; Löhneysen, H. v.; Hoffmann-Vogel, R.

    2016-12-01

    We have studied controlled electromigration (EM) in free-standing copper wires. Besides electrical characterization by voltage-current measurements, structural analyses have been performed by means of scanning electron microscopy and cross-sectional microprobe measurements. We have found that oxidation during the EM in air stabilizes the free-standing wire against uncontrolled blowing, making it possible to thin the conductive part of the wire down to a conductance of a few conductance quanta G_0=2e^2{/}h. The decisive influence of oxidation by air on the EM process was confirmed by control experiments performed under ultra-high vacuum conditions. In line with these findings, free-standing Au wires were difficult to thin down reproducibly to a conductance of a few G_0. Estimates of the local temperature in the free-standing wire are obtained from finite element method calculations.

  6. Ultrasonic Device for Assessing the Quality of a Wire Crimp

    Science.gov (United States)

    Yost, William T. (Inventor); Perey, Daniel F. (Inventor); Cramer, Karl E. (Inventor)

    2015-01-01

    A system for determining the quality of an electrical wire crimp between a wire and ferrule includes an ultrasonically equipped crimp tool (UECT) configured to transmit an ultrasonic acoustic wave through a wire and ferrule, and a signal processor in communication with the UECT. The signal processor includes a signal transmitting module configured to transmit the ultrasonic acoustic wave via an ultrasonic transducer, signal receiving module configured to receive the ultrasonic acoustic wave after it passes through the wire and ferrule, and a signal analysis module configured to identify signal differences between the ultrasonic waves. The signal analysis module is then configured to compare the signal differences attributable to the wire crimp to a baseline, and to provide an output signal if the signal differences deviate from the baseline.

  7. Twinning across the Developing World.

    Directory of Open Access Journals (Sweden)

    Jeroen Smits

    Full Text Available BACKGROUND: Until now, little was known about the variation in incidence of twin births across developing countries, because national representative data was lacking. This study provides the first comprehensive overview of national twinning rates across the developing world on the basis of reliable survey data. METHODS: Data on incidence of twinning was extracted from birth histories of women aged 15-49 interviewed in 150 Demographic and Health Surveys, held between 1987 and 2010 in 75 low and middle income countries. During the interview, information on all live births experienced by the women was recorded, including whether it was a singleton or multiple birth. Information was available for 2.47 million births experienced by 1.38 million women in a period of ten years before the interview. Twinning incidence was measured as the number of twin births per thousand births. Data for China were computed on the basis of published figures from the 1990 census. Both natural and age-standardized twinning rates are presented. RESULTS/CONCLUSIONS: The very low natural twinning rates of 6-9 per thousand births previously observed in some East Asian countries turn out to be the dominant pattern in the whole South and South-East Asian region. Very high twinning rates of above 18 per thousand are not restricted to Nigeria (until now seen as the world's twinning champion but found in most Central-African countries. Twinning rates in Latin America turn out to be as low as those in Asia. Changes over time are small and not in a specific direction. SIGNIFICANCE: We provide the most complete and comparable overview of twinning rates across the developing world currently possible.

  8. Twinning and heteropaternity in chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Ely, John J; Frels, William I; Howell, Sue; Izard, M Kay; Keeling, Michale E; Lee, D Rick

    2006-05-01

    Unlike monozygotic (MZ) twins, dizygotic (DZ) twins develop from separate ova. The resulting twins can have different sires if the fertilizing sperm comes from different males. Routine paternity testing of a pair of same-sexed chimpanzee twins born to a female housed with two males indicated that the twins were sired by two different males. DNA typing of 22 short-tandem repeat (STR) loci demonstrated that these twins were not MZ twins but heteropaternal DZ twins. Reproductive data from 1926-2002 at five domestic chimpanzee colonies, including 52 twins and two triplets in 1,865 maternities, were used to estimate total twinning rates and the MZ and DZ components. The average chimpanzee MZ twinning rate (0.43%) equaled the average human MZ rate (0.48%). However, the chimpanzee DZ twinning rate (2.36%) was over twice the human average, and higher than all but the fertility-enhanced human populations of Nigeria. Similarly high twinning rates among African chimpanzees indicated that these estimates were not artifacts of captivity. Log-linear analyses of maternal and paternal effects on recurrent twinning indicated that females who twinned previously had recurrence risks five times greater than average, while evidence for a paternal twinning effect was weak. Chimpanzee twinning rates appear to be elevated relative to corresponding estimated human rates, making twinning and possibly heteropaternity more important features of chimpanzee reproductive biology than previously recognized.

  9. Twin Legacies: Victor and Vincent McKusick/Twin Studies: Twinning Rates I; Twinning Rates II; MZ Twin Discordance for Russell-Silver Syndrome; Twins' Language Skills/Headlines: Babies Born to Identical Twin Couples; Identity Exchange; Death of Princess Ashraf (Twin); Yahoo CEO Delivers Identical Twins.

    Science.gov (United States)

    Segal, Nancy L

    2016-04-01

    The lives of the illustrious monozygotic (MZ) twins, Victor A. and Vincent L. McKusick, are described. Victor earned the distinction as the 'Father of Medical Genetics', while Vincent was a legendary Chief Justice of the Maine Supreme Court. This dual biographical account is followed by two timely reports of twinning rates, a study of MZ twin discordance for Russell-Silver Syndrome (RSS) and a study of twins' language skills. Twin stories in the news include babies born to identical twin couples, a case of switched identity, the death of Princess Ashraf (Twin) and a new mother of twins who is also Yahoo's CEO.

  10. Estimating twin concordance for bivariate competing risks twin data

    DEFF Research Database (Denmark)

    Scheike, Thomas Harder; Holst, Klaus Kähler; von Bornemann Hjelmborg, Jacob

    2014-01-01

    For twin time-to-event data, we consider different concordance probabilities, such as the casewise concordance that are routinely computed as a measure of the lifetime dependence/correlation for specific diseases. The concordance probability here is the probability that both twins have experienced...... over time, and covariates may be further influential on the marginal risk and dependence structure. We establish the estimators large sample properties and suggest various tests, for example, for inferring familial influence. The method is demonstrated and motivated by specific twin data on cancer...... the event of interest. Under the assumption that both twins are censored at the same time, we show how to estimate this probability in the presence of right censoring, and as a consequence, we can then estimate the casewise twin concordance. In addition, we can model the magnitude of within pair dependence...

  11. Niobium and tantalum: indispensable twins

    Science.gov (United States)

    Schulz, Klaus; Papp, John

    2014-01-01

    Niobium and tantalum are transition metals almost always paired together in nature. These “twins” are difficult to separate because of their shared physical and chemical properties. In 1801, English chemist Charles Hatchett uncovered an unknown element in a mineral sample of columbite; John Winthrop found the sample in a Massachusetts mine and sent it to the British Museum in London in 1734. The name columbium, which Hatchet named the new element, came from the poetic name for North America—Columbia—and was used interchangeably for niobium until 1949, when the name niobium became official. Swedish scientist Anders Ekberg discovered tantalum in 1802, but it was confused with niobium, because of their twinned properties, until 1864, when it was recognized as a separate element. Niobium is a lustrous, gray, ductile metal with a high melting point, relatively low density, and superconductor properties. Tantalum is a dark blue-gray, dense, ductile, very hard, and easily fabricated metal. It is highly conductive to heat and electricity and renowned for its resistance to acidic corrosion. These special properties determine their primary uses and make niobium and tantalum indispensable.

  12. Computer simulation of metal wire explosion under high rate heating

    Science.gov (United States)

    Zolnikov, K. P.; Kryzhevich, D. S.; Korchuganov, A. V.

    2017-05-01

    Synchronous electric explosion of metal wires and synthesis of bicomponent nanoparticles were investigated on the base of molecular dynamics method. Copper and nickel nanosized crystallites of cylindrical shape were chosen as conductors for explosion. The embedded atom approximation was used for calculation of the interatomic interactions. The agglomeration process after explosion metal wires was the main mechanism for particle synthesis. The distribution of chemical elements was non-uniform over the cross section of the bicomponent particles. The copper concentration in the surface region was higher than in the bulk of the synthesized particle. By varying the loading parameters (heating temperature, the distance between the wires) one can control the size and internal structure of the synthesized bicomponent nanoparticles. The obtained results showed that the method of molecular dynamics can be effectively used to determine the optimal technological mode of nanoparticle synthesis on the base of electric explosion of metal wires.

  13. Confronting Twin Paradox Acceleration

    Science.gov (United States)

    Murphy, Thomas W.

    2016-05-01

    The resolution to the classic twin paradox in special relativity rests on the asymmetry of acceleration. Yet most students are not exposed to a satisfactory analysis of what exactly happens during the acceleration phase that results in the nonaccelerated observer's more rapid aging. The simple treatment presented here offers both graphical and quantitative solutions to the problem, leading to the correct result that the acceleration-induced age gap is 2Lβ years when the one-way distance L is expressed in light-years and velocity β ≡v/c .

  14. Holographic twin Higgs model.

    Science.gov (United States)

    Geller, Michael; Telem, Ofri

    2015-05-15

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.

  15. Oliver Sacks: Our Correspondence About Twins/Twin Research: Vanishing Twins Syndrome; Discordant Sex in MZ Twins; Pregnancy Outcomes in IVF and ICSI Conceived Twins/Print and Media: Superfetated Twins; Twins Discordant for Smoking; Twins in Fashion; Yale University Twin Hockey Players; Conjoined Twin-Visiting Professor.

    Science.gov (United States)

    Segal, Nancy L

    2017-08-01

    The late neurologist and author, Oliver Sacks, published an insightful 1986 review of Marjorie Wallace's book, The Silent Twins, in the New York Times. Taking exception to his assertion about Sir Francis Galton, I wrote a letter to the Times' editor. The letter was unpublished, but it brought a wonderful response from Sacks himself that is reproduced and examined. Next, brief reviews of twin research concerning the vanishing twin syndrome (VTS), discordant sex in a monozygotic (MZ) twin pair, and multiple pregnancy outcomes from assisted reproductive technology (ART) are presented. This section is followed by popular coverage of superfetated twins, smoking-discordant co-twins, twins in fashion, Yale University twin hockey players, and a visiting professor who was a conjoined twin.

  16. Peltier effect in strongly driven quantum wires

    OpenAIRE

    Mierzejewski, M.; Crivelli, D.; Prelovsek, P.

    2013-01-01

    We study a microscopic model of a thermocouple device with two connected correlated quantum wires driven by a constant electric field. In such isolated system we follow the time-- and position--dependence of the entropy density using the concept of the reduced density matrix. At weak driving, the initial changes of the entropy at the junctions can be described by the linear Peltier response. At longer times the quasiequilibrium situation is reached with well defined local temperatures which i...

  17. Transformation: From Twin to Individual

    Science.gov (United States)

    Magagna, Jeanne

    2007-01-01

    This article explores some of the complexities of psychotherapy with an identical twin. The difficulty of developing in psychotherapy while so much of what is oneself is located in the other twin will also be explored. The use of the countertransference as a therapeutic method will be considered as the young person develops her unique, separate…

  18. Twin Studies of Atopic Dermatitis

    DEFF Research Database (Denmark)

    Elmose, Camilla; Thomsen, Simon Francis

    2015-01-01

    Aim. The aim of this study was to conduct a systematic review of population-based twin studies of (a) the concordance and heritability of AD and (b) the relationship between AD and asthma and, furthermore, to reinterpret findings from previous twin studies in the light of the emerging knowledge a...

  19. Twin methodology in epigenetic studies

    DEFF Research Database (Denmark)

    Tan, Qihua; Christiansen, Lene; von Bornemann Hjelmborg, Jacob

    2015-01-01

    Since the final decades of the last century, twin studies have made a remarkable contribution to the genetics of human complex traits and diseases. With the recent rapid development in modern biotechnology of high-throughput genetic and genomic analyses, twin modelling is expanding from analysis ...

  20. Twin Higgs WIMP Dark Matter

    CERN Document Server

    García, Isabel García; March-Russell, John

    2015-01-01

    Dark matter (DM) without a matter asymmetry is studied in the context of Twin Higgs (TH) theories in which the LHC naturalness problem is addressed. These possess a twin sector related to the Standard Model (SM) by a (broken) $\\mathbb{Z}_2$ symmetry, and interacting with the SM via a specific Higgs portal. We focus on the minimal realisation of the TH mechanism, the Fraternal Twin Higgs, with only a single generation of twin quarks and leptons, and $SU(3)'\\times SU(2)'$ gauge group. We show that a variety of natural twin-WIMP DM candidates are present (directly linked to the weak scale by naturalness), the simplest and most attractive being the $\\tau^\\prime$ lepton with a mass $m_{\\tau^\\prime} > m_{\\rm Higgs}/2$, although spin-1 $W^{\\prime\\pm}$ DM and multicomponent DM are also possible (twin baryons are strongly disfavoured by tuning). We consider in detail the dynamics of the possibly (meta)stable glueballs in the twin sector, the nature of the twin QCD phase transition, and possible new contributions to th...

  1. Hypertensive disorders in twin pregnancy

    NARCIS (Netherlands)

    J.G. Santema (Job); E. Koppelaar (Elin); H.C.S. Wallenburg (Henk)

    1995-01-01

    textabstractObjective: To compare the incidence and severity of pregnancy-induced hypertensive disorders in twin pregnancy and in singleton gestation. Study design: Case-control study in the setting of a University Hospital. Each pregnancy of a consecutive series of 187 twin pregnancies attending th

  2. Conductance of a quantum wire in the Wigner crystal regime

    OpenAIRE

    Matveev, K. A.

    2003-01-01

    We study the effect of Coulomb interactions on the conductance of a single-mode quantum wire connecting two bulk leads. When the density of electrons in the wire is very low, they arrange in a finite-length Wigner crystal. In this regime the electron spins form an antiferromagnetic Heisenberg chain with exponentially small coupling J. An electric current in the wire perturbs the spin chain and gives rise to a temperature-dependent contribution of the spin subsystem to the resistance. At low t...

  3. Addressing water vaporization in the vicinity of an exploding wire

    Science.gov (United States)

    Grinenko, A.; Gurovich, V. Tz.; Krasik, Ya. E.; Dolinsky, Yu.

    2006-12-01

    The phase state of thin (˜1μm) layer of water adjacent to the surface of rapidly heated thin wire 100±50μm in radius is analyzed by computer hydrodynamic calculation. It is shown that when heating of a wire to a temperature of 420°C is achieved in less than ˜500ns, the trajectory of the phase state is contained in the liquid part of the phase diagram. This suggests additional proof of and an explanation for the absence of shunting plasma discharge in fast underwater electrical wire explosions.

  4. Wire system ageing assessment and condition monitoring (WASCO)

    Energy Technology Data Exchange (ETDEWEB)

    Fantoni, P.F. (Institute for Energy Technology (IFE) (Norway))

    2009-07-15

    Nuclear facilities rely on electrical wire systems to perform a variety of functions for successful operation. Many of these functions directly support the safe operation of the facility; therefore, the continued reliability of wire systems, even as they age, is critical. Condition Monitoring (CM) of installed wire systems is an important part of any aging program, both during the first 40 years of the qualified life and even more in anticipation of the license renewal for a nuclear power plant. This report contains the results of experiments performed in collaboration with Tecnatom SA, Spain, to compare several cable condition monitoring techniques including LIRA (LIne Resonance Analysis) (au)

  5. A Computational Discriminability Analysis on Twin Fingerprints

    Science.gov (United States)

    Liu, Yu; Srihari, Sargur N.

    Sharing similar genetic traits makes the investigation of twins an important study in forensics and biometrics. Fingerprints are one of the most commonly found types of forensic evidence. The similarity between twins’ prints is critical establish to the reliability of fingerprint identification. We present a quantitative analysis of the discriminability of twin fingerprints on a new data set (227 pairs of identical twins and fraternal twins) recently collected from a twin population using both level 1 and level 2 features. Although the patterns of minutiae among twins are more similar than in the general population, the similarity of fingerprints of twins is significantly different from that between genuine prints of the same finger. Twins fingerprints are discriminable with a 1.5%~1.7% higher EER than non-twins. And identical twins can be distinguished by examine fingerprint with a slightly higher error rate than fraternal twins.

  6. Dramatically different dizygotic twins: will we include them in Research? Twin research reviews: congenital anomalies, mirror-image effects in conjoined twins, older mothers of twins; Twin statistics: 'Massachusetts, land of twins'; Tribute: Dr Victor A. McKusick.

    Science.gov (United States)

    Segal, Nancy L

    2008-10-01

    The increased frequency of interracial marriage is a likely source of unusual-looking dizygotic (DZ) twins. Some members of DZ twin pairs born to mixed-race couples inherit very different physical features from their parents. This raises several questions, such as: Will researchers wish to include such twins in their ongoing studies? Next, new twin research concerned with congenital anomalies, mirror-image effects in conjoined twins and older mothers of twins will be reviewed. New statistics on twinning rates in Massachusetts will also be summarized, followed by a tribute to the late medical geneticist Dr. Victor A. McKusick.

  7. [Hereditary phaeochromocytoma in twins].

    Science.gov (United States)

    Tóth, Géza; Patócs, Attila; Tóth, Miklós

    2016-08-01

    Phaeochromocytoma is a tumor of the catecholamine-producing cells of the adrenal gland. Extraadrenal phaeochromocytomas are frequently called paragangliomas. The majority of phaeochromocytomas are sporadic, however, about 25-30% are caused by genetic mutation. These tumor are frequently referred as hereditary phaeochromocytomas/paragangliomas. Their incidence increases continuously which can be attributed to availability of genetic examination and to the discovery of novel genes. The 47-year-old female patient underwent abdominal computed tomography which revealed bilateral adrenal gland enlargement. Abdominal magnetic resonance imaging, the 131-I- metaiodobenzylguanidine scintigraphy, urinary catecholamines and serum chomogranin A measurements confirmed the diagnosis of bilateral phaeochromocytomas. The genetically identical twin sister of the patient was also diagnosed with hormonally active bilateral phaechromocytoma, suggesting the genetic origin of phaeochromocytoma. Mutation screening confirmed a germline mutation of the transmembrane protein 127 tumorsupressor gene in both patients. Both patients underwent cortical-sparing adrenalectomy. The adrenal gland with the larger tumor was totally resected, while in the opposite side only the tumor was resected and a small part of the cortex was saved. After the operation urinary catecholamines and serum chromogranin A returned to normal in both patients. Adrenocortical deficiency was absent in the first patient, but her sister developed adrenal insufficiency requiring glucocorticoid replacement. To the best of the authors' knowledge phaeochromocytoma affecting twins has never been described earlier. Genetic examination performed in siblings confirmed the presence of the mutant gene through four generations. Orv. Hetil., 2016, 157(33), 1326-1330.

  8. 智能电能表无导线连接式开关电源设计技术探讨%Design of single-phase intelligent electric meter base on switching power and hard-wired

    Institute of Scientific and Technical Information of China (English)

    丁乔乐; 张向程; 李辉; 苍久蛟

    2015-01-01

    传统表计整机功耗高,易受工频磁场干扰,生产不便,质量不好,可靠性不高;为了克服上述不足,本文介绍了一款硬连接式开关电源单相智能电能表,详述了该表的优势、硬件整体设计框图、各单元功能说明、线路板图以及装配图;该表采用无导线硬连接方式,生产方便,节省人力资源成本,工频防潜值低且稳定;表计采用开关电源供电,整表功耗低,电压量程宽,重量轻;表计其他硬件功能电路设计,进一步提高了产品的可靠性;该表已通过我司检测中心测试,基本参数符合国网、南网要求,产品质量好,可靠性高,我司正积极完善此款表,逐步推向市场。%The traditional single-phase intelligent meter has many disadvantages such as high-power consumption, im-pact by the power-frequency magnetic field easily, not conducive to productivity and poor reliability; To overcome these disadvantages, this article describes a single-phase smart electric meter based on switching power and hard-wired from the following part:the advantage of the meter, the block diagram of the hardware, the function description of each unit, the circuit board and assembly drawing;this meter adopts the wireless connection that can facilitates the produc-tion, saves the cost of human resource and reduces the impact of frequency magnetic fields;Powered by the switching power, the meter has the advantages of low power consumption, wide voltage range and light weight. Other hardware de-sign improves the reliability of the meter as well. This meter has passed test by our company, the hardware performance can meet the requirement of National Grid and Southern Power Grid, Our company is actively improving this meter and planning to push the market gradually.

  9. The Processing Efficiency Optimization of Titanium-zir-conium-molybdenum by Wire Electrical-discharge Machining%钼钛锆高温合金电火花线切割加工效率优化

    Institute of Scientific and Technical Information of China (English)

    朱颖谋; 孙长宏; 牛禄; 顾琳

    2015-01-01

    In order to study the processing efficiency of Titanium-zir-conium-molybdenum (TZM) by unidirectional traveling wire electrical-discharge machining (WEDM) ,a 25-1 fractional factorial experiment was designed to screen out the significant discharge parameters which markedly influence the experiment results. A further full factorial experiment was conducted to explore the machining performance of TZM by unidirectional traveling WEDM under different pulse durations ,duty cycles and peak currents. On the basis of full-factorial experimental results ,a central composite response surface experiment was designed to explore the pattern of machining efficiency ,and fit the empirical formula of processing efficiency through the experiment. The verification experiment was designed to verify the accuracy of the recommended formula ,and the experimental results show that the actual machining efficiency agree with the theoretical value. Furthermore ,the parameters scope of the formula and the influence of peak current on surface roughness were analysed.%为研究钼钛锆高温合金的单向走丝电火花线切割加工效率问题,通过25-1析因实验对影响加工效率的因素进行了筛选,得出影响显著的加工参数为脉宽、峰值电流和占空比,进而设计了三因素全因子实验并研究了显著因素对加工效率的影响。在此基础上,设计了中心复合响应曲面实验,通过实验结果拟合出加工效率的推荐公式。证实了在参数适用范围内,实际加工效率与拟合公式值吻合。此外,还分析了模型的参数适用范围及峰值电流对加工工件表面粗糙度的影响。

  10. Electromagnetic Nondestructive Evaluation of Wire Insulation and Models of Insulation Material Properties

    Science.gov (United States)

    Bowler, Nicola; Kessler, Michael R.; Li, Li; Hondred, Peter R.; Chen, Tianming

    2012-01-01

    Polymers have been widely used as wiring electrical insulation materials in space/air-craft. The dielectric properties of insulation polymers can change over time, however, due to various aging processes such as exposure to heat, humidity and mechanical stress. Therefore, the study of polymers used in electrical insulation of wiring is important to the aerospace industry due to potential loss of life and aircraft in the event of an electrical fire caused by breakdown of wiring insulation. Part of this research is focused on studying the mechanisms of various environmental aging process of the polymers used in electrical wiring insulation and the ways in which their dielectric properties change as the material is subject to the aging processes. The other part of the project is to determine the feasibility of a new capacitive nondestructive testing method to indicate degradation in the wiring insulation, by measuring its permittivity.

  11. Distribution of wire deformation within strands of wire ropes

    Institute of Scientific and Technical Information of China (English)

    MA Jun; GE Shi-rong; ZHANG De-kun

    2008-01-01

    Using ANSYS software, we developed a modeling program for several kinds of wire ropes with metal cores and built a geometric model for the 6x19 IWS wire rope. Through proper grid partitioning, a finite element model for calculating the deformation of wire rope was obtained. Completely constraining one end of the wire rope and applying an axial force to the other end, we established the boundary conditions for solving the model. In addition, we numerically simulated the stress and deformation of the wire, obtaining the deformation distribution of each wire within the wire rope under different laying directions.At the end, a tensile test of the 6x19 IWS wire rope was carried out and the results of simulation and experiment compared.

  12. Twin-box ITER joints under electromagnetic transient loads

    Energy Technology Data Exchange (ETDEWEB)

    Stepanov, Boris, E-mail: boris.stepanov@psi.ch; Bruzzone, Pierluigi; March, Stephen; Sedlak, Kamil

    2015-10-15

    Highlights: • ITER “twin-box” joint design. • Dependence of the joint resistance on current. • Resistance change under the transient electromagnetic load. • Breakdown of the contributions to the joint resistance. • Field dump and conductor performance behind the twin-box joint. - Abstract: The ITER Toroidal Field (TF) coil winding packs are designed to be wound in double-pancakes. The twin-box joint provides the electrical pancake-to-pancake connection between the two Nb{sub 3}Sn 68 kA conductors and electrical coil-to-bus bar connection between the TF coil terminations and NbTi 68 kA bus bars conductors. The twin-box full size joint sample connecting two Nb{sub 3}Sn conductors (pancake-to-pancake joint) was prepared in order to qualify the TF joint assembly in SULTAN Test Facility. The original goal of the test program was the measurement of joint resistance at different operating conditions. The accidental dump of the SULTAN background field caused a noticeable increase of resistance due to the induced electromagnetic transient load. The TF joint test was continued in order to investigate a change of joint resistance following electromagnetic transient loading which was triggered by intentional dump of the background field. Also, a dependence of the joint resistance on current was observed; in order to explore the origin of resistance change, additional experiments were performed with a modified (artificially degraded) TF twin-box joint. The test results of a TF twin-box joint after electromagnetic transient loading and performance of the joint after a modification are presented in this paper. The performance of Nb{sub 3}Sn 68 kA conductor observed during those tests is highlighted as well.

  13. Twins and Kindergarten Separation: Divergent Beliefs of Principals, Teachers, Parents, and Twins

    Science.gov (United States)

    Gordon, Lynn Melby

    2015-01-01

    Should principals enforce mandatory separation of twins in kindergarten? Do school separation beliefs of principals differ from those of teachers, parents of twins, and twins themselves? This survey questioned 131 elementary principals, 54 kindergarten teachers, 201 parents of twins, and 112 twins. A majority of principals (71%) believed that…

  14. Methodology for Measurement of Submicron Metallic Wire's Local Electrical Conductivity by Applying Four-points AFM Probe Technique%金属薄膜导线的亚微米局域电导率精确测量技术

    Institute of Scientific and Technical Information of China (English)

    吴蕾; 葛耀峥; 居冰峰

    2011-01-01

    作为薄膜器件最重要物理量之一的局域电导率的定量测定,能在保证性能、提高成品率、完善制作工艺等方面起关键作用.利用基于原子力显微镜(Atomic force microscope,AFM)的4电极微探针局域电导率测量技术,精确测量厚度为350nm、宽度分别为50.0 μm、25.0μm、5.0 μm、2.0μm及600 nm、纯度为99.999%的铝薄膜导线的电导率.由于被测试件宽度和厚度方向的尺寸明显缩小且十分接近电极的最小间距,综合考虑电极尺寸、不同批次电极的加工精度和加工参数、4个电极间的位置误差等几个影响测量精度的因素,修正电导率的计算模型并将传统4电极电导率测量法的应用领域拓展到亚微米级微观尺度.试验结果证明基于AFM的4电极微探针技术在亚微米级局域电导率测量方面的能力.%The quantitative measurement of electrical conductivity plays a key role in ensuring material performance, improving yield and fabrication process. The four-points AFM probe technique is applied for the purpose of quantitatively measuring local conductivities of the 99.999% aluminum wires and 350 nm thickness and different widths of 600 mn, 2.0 μm, 5.0 μm, 25.0 βm and 50.0 βm. As position the width and thickness of the specimen is very close to the minimum distance of the electrodes, we consider the factors that affect the measurement accuracy, such as size, diversity of parameter and precision in processing and position error of the four-points AFM probe, modify the calculation model of conductivity and extend the traditional four-electrode conductivity measurements to the sub-micron level. The repeatability of conductivity measurements indicates that this four-point AFM probe technique could be used for fast in situ characterization of local electrical properties of nanocircuits and nanodevices.

  15. Paternal age and telomere length in twins

    DEFF Research Database (Denmark)

    Hjelmborg, Jacob B; Dalgård, Christine; Mangino, Massimo

    2015-01-01

    . Based on two independent (discovery and replication) twin studies, comprising 889 twin pairs, we show an increase in the resemblance of leukocyte telomere length between dizygotic twins of older fathers, which is not seen in monozygotic twins. This phenomenon might result from a paternal age...

  16. Recipient twin limb ischemia with postnatal onset.

    Science.gov (United States)

    Broadbent, Roland Spencer

    2007-02-01

    After the occurrence of 3 local cases of limb ischemia in newborn twins, we reviewed the literature to investigate this combination systematically. This review reveals a distinct condition: postnatal onset limb ischemia affecting recipient twins in twin-twin transfusion syndrome.

  17. Best Practices for Twin Placement in School

    Science.gov (United States)

    Lacina, Jan

    2012-01-01

    The children's book "Two Is for Twins" celebrates twins and illustrates the many "twos" in a child's world. The uniqueness of twos does not have to mean separate classrooms for twins in child development programs, preschool, or elementary school settings. With recent dramatic increases in the US twin population, how should educators address the…

  18. Best Practices for Twin Placement in School

    Science.gov (United States)

    Lacina, Jan

    2012-01-01

    The children's book "Two Is for Twins" celebrates twins and illustrates the many "twos" in a child's world. The uniqueness of twos does not have to mean separate classrooms for twins in child development programs, preschool, or elementary school settings. With recent dramatic increases in the US twin population, how should educators address the…

  19. Twin Higgs Asymmetric Dark Matter.

    Science.gov (United States)

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

  20. Twin methodology in epigenetic studies.

    Science.gov (United States)

    Tan, Qihua; Christiansen, Lene; von Bornemann Hjelmborg, Jacob; Christensen, Kaare

    2015-01-01

    Since the final decades of the last century, twin studies have made a remarkable contribution to the genetics of human complex traits and diseases. With the recent rapid development in modern biotechnology of high-throughput genetic and genomic analyses, twin modelling is expanding from analysis of diseases to molecular phenotypes in functional genomics especially in epigenetics, a thriving field of research that concerns the environmental regulation of gene expression through DNA methylation, histone modification, microRNA and long non-coding RNA expression, etc. The application of the twin method to molecular phenotypes offers new opportunities to study the genetic (nature) and environmental (nurture) contributions to epigenetic regulation of gene activity during developmental, ageing and disease processes. Besides the classical twin model, the case co-twin design using identical twins discordant for a trait or disease is becoming a popular and powerful design for epigenome-wide association study in linking environmental exposure to differential epigenetic regulation and to disease status while controlling for individual genetic make-up. It can be expected that novel uses of twin methods in epigenetic studies are going to help with efficiently unravelling the genetic and environmental basis of epigenomics in human complex diseases.

  1. The vector-like twin Higgs

    Science.gov (United States)

    Craig, Nathaniel; Knapen, Simon; Longhi, Pietro; Strassler, Matthew

    2016-07-01

    We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.

  2. The Vector-like Twin Higgs

    CERN Document Server

    Craig, Nathaniel; Longhi, Pietro; Strassler, Matthew

    2016-01-01

    We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.

  3. Properties of NiTi wires with direct electric resistance heat treatment method in three-point bending tests%直流电热处理对镍钛合金丝三点弯曲性能的影响

    Institute of Scientific and Technical Information of China (English)

    王红梅; 王邦康; 任超超; 白玉兴

    2011-01-01

    Objective To investigate the mechanical properties of Ni-Ti wires with direct electric resistance heat treatment(DERHT) method in three-point bending tests. Methods Two superelastic Ni-Ti wires(wire A: Smart SE, wire B: SENTALLOY SE, 0.406 mm ×0.559 mm) and 2 heat-actived Ni-Ti wires(wire C: Smart SM, wire D: L&H TITAN, 0.406 mm ×0.559 mm) were selected. They were heattreated using the DERHT method by a controlled electric current(6. 36 A) applied for different period of time[0(control), 1.0, 1.5, 2. 0, 2. 5 seconds). Then, a three-point bending test was performed under controlled temperature (37 ℃ ) to examine the relationships between the deflection and the load in the bending of wires. Results After DERHT treatment, the plateau in the force-deflection curve of superelastic Ni-Ti wires and heat-actived Ni-Ti wires were increased. When the wires were heated for 2. 0 seconds and deflected to 1.5 mm, the loading force of A, B, C and D Ni-Ti wires increased from (3.85 ± 0. 11 ),(3.62±0.07), (3.28±0.09), (2.91 ±0.23) Nto (4.33 ±0.07), (4.07 ±0.05), (4.52±0.08),(3.27 ± 0. 15 ) N respectively. Conclusions DERHT method is very convenient for clinical use. It is possible to change the arch form and superelastic force of NiTi wires. The longer the heating time is, the more the superelastic characteristics of the wires are altered.%目的 探讨直流电热处理后镍钛合金丝三点弯曲性能的变化规律,以期更好地发挥镍钛合金丝在临床治疗中的作用.方法 选择两种超弹性镍钛合金丝(弓丝A:圣马特超弹性镍钛合金牙齿矫形丝;弓丝B:SENTALLOY(R)超弹性镍钛合金丝)和两种热激活镍钛合金丝(弓丝C:圣马特热激活镍钛合金牙齿矫形丝;弓丝D:L&H镍钛丝),用加热仪分别对弓丝进行0(对照)、1.0、1.5、2.0、2.5 s的直流电热处理(恒定电流强度6.36 A);在37℃下利用三点弯曲实验检测弓丝的性能变化.结果 热处理后镍钛合金丝的平台期

  4. Fivefold twinned boron carbide nanowires.

    Science.gov (United States)

    Fu, Xin; Jiang, Jun; Liu, Chao; Yuan, Jun

    2009-09-01

    Chemical composition and crystal structure of fivefold twinned boron carbide nanowires have been determined by electron energy-loss spectroscopy and electron diffraction. The fivefold cyclic twinning relationship is confirmed by systematic axial rotation electron diffraction. Detailed chemical analysis reveals a carbon-rich boron carbide phase. Such boron carbide nanowires are potentially interesting because of their intrinsic hardness and high temperature thermoelectric property. Together with other boron-rich compounds, they may form a set of multiply twinned nanowire systems where the misfit strain could be continuously tuned to influence their mechanical properties.

  5. Failure of vincristine induce twinning

    Science.gov (United States)

    Binder, M.

    1984-01-01

    Mammalian ova do not contain axes of symmetry from which are derived embryonic axes of symmetry. Mammalian axis determination is an early embryologic event occurring at about the time that monozygous twinning in mice. (Kaufma MH & O'Shea KS, 1978, Nature 276:707) and an attempt was made to reproduce their work in several strains of mice. Over 3200 embryos were examined without any twins being found. To rule out the possibility that vincristine caused twinning plus some lethal malformation (with subsequent resorption of the embryo) the embryos were examined 36-60 hours after vincristine treatment.

  6. Practical wiring in SI units

    CERN Document Server

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  7. 3D Wire 2015

    DEFF Research Database (Denmark)

    Jordi, Moréton; F, Escribano; J. L., Farias

    This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and ha......, improves socialization and networking, improves media impact, improves fun factor and improves encouragement of the production team....

  8. One-wire thermocouple

    Science.gov (United States)

    Goodrich, W. D.; Staimach, C. J.

    1977-01-01

    Nickel alloy/constantan device accurately measures surface temperature at precise locations. Device is moderate in cost and simplifies fabrication of highly-instrumented seamless-surface heat-transfer models. Device also applies to metal surfaces if constantan wire has insulative coat.

  9. Electrochemical corrosion behavior of steel wires in a coalmine with a corrosive medium

    Institute of Scientific and Technical Information of China (English)

    Wang Songquan; Zhang Dekun; Wang Dagang; Zhang Zefeng

    2011-01-01

    A 6 × 19 point-contact hoisting cable was used as our research object to examine the progress of corrosion of steel wires in a laboratory, simulating the actual working conditions in a coalmine. An electrochemical method was used to investigate the corrosion behavior of steel wires with different surface treatments of a corrosive acid solution. The results show that anode activation of steel wire mainly occurs during pre-corrosion, where the anode activation process of bare steel wires is the fastest as is their corresponding corrosion speed, while the anode activation process of oil coated steel wires and their corresponding corrosion speed are the lowest. During the intermediate and late immersion periods,a passive film is generated on the surface of steel wires, which are gradually damaged with the passage of time. Local pitting corrosion occurs easily on the surface of steel wires with a high-polarization potential.Suitable equivalent circuits were chosen to fit the electrochemical impedance spectroscopy (EIS) of steel wires over various corrosive times and different surface treatments, which indicate good fitting results.The double electrical layer charge-transfer resistance increases in the sequence: bare steel wire,untreated steel wire and oil coated steel wire and their corrosion resistance decreases in turn, which is consistent with their polarization curves. The oil layer provides a certain protective effect on untreated steel wires, but its effect is not entirely clear.

  10. Parallel-wire grid assembly with method and apparatus for construction thereof

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, Edward F. (Westmont, IL); Vrabec, John (South Holland, IL)

    1984-01-01

    Disclosed is a parallel wire grid and an apparatus and method for making the same. The grid consists of a generally coplanar array of parallel spaced-apart wires secured between metallic frame members by an electrically conductive epoxy. The method consists of continuously winding a wire about a novel winding apparatus comprising a plurality of spaced-apart generally parallel spindles. Each spindle is threaded with a number of predeterminedly spaced-apart grooves which receive and accurately position the wire at predetermined positions along the spindle. Overlying frame members coated with electrically conductive epoxy are then placed on either side of the wire array and are drawn together. After the epoxy hardens, portions of the wire array lying outside the frame members are trimmed away.

  11. Summary of the First Generation High Temperature Superconducting Wire:Processing, Characterization and Applications

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Silver-clad (Bi,Pb)2Sr2Ca2Cu3O10+x long wires produced by powder-in-tube techniques, which have been recognized as the first generation of the High Temperature Superconducting (HTS) wires, are expected to apply widely especially in strong current applications. In this work, the processing, characterization and application of the silver-clad (Bi,Pb)2Sr2Ca2Cu3O10+x HTS wires are summarized. The HTS wires are fabricated using the combination of powder-in-tube technique, and the resulting wires are fully characterized by the means of chemical analyses, microstructural observation, electrical and magnetic measurements. The relationship among fabrication parameters, chemical and microstructural characteristics, and electrical and magnetic properties are analyzed. Applications of the HTS wires have also been introduced according to their strong current behaviors with various prototype devices made.

  12. Twin-to-twin transfusion syndrome : from placental anastomoses to long-term outcome

    NARCIS (Netherlands)

    Lopriore, Enrico

    2006-01-01

    Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Placental vascular anastomoses, almost invariably present in monochorionic placentas, are the essential anatomical substrate for the devel

  13. Twin-to-twin transfusion syndrome : from placental anastomoses to long-term outcome

    NARCIS (Netherlands)

    Lopriore, Enrico

    2006-01-01

    Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Placental vascular anastomoses, almost invariably present in monochorionic placentas, are the essential anatomical substrate for the

  14. Twin-to-twin transfusion syndrome : from placental anastomoses to long-term outcome

    NARCIS (Netherlands)

    Lopriore, Enrico

    2006-01-01

    Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Placental vascular anastomoses, almost invariably present in monochorionic placentas, are the essential anatomical substrate for the devel

  15. Simultaneous Intussusception in Monozygotic Twins

    Directory of Open Access Journals (Sweden)

    Mete Kaya

    2014-12-01

    Full Text Available In this case report, it was aimed to present the simultaneously occurring intussusception in the monozygotic twins. In addition to genetic predisposition, environmental factors has been hypothesized to be responsible for the development of the disease.

  16. Discordant Epilepsy in Monozygous Twins

    OpenAIRE

    2001-01-01

    Twelve monozygotic twins, discordant for epilepsy, were analysed for nonhereditary etiological factors by clinical history, MRI, and quantitative brain volume studies at the Brain Research Institute, University of Melbourne, Victoria, Australia.

  17. Flexible and weaveable capacitor wire based on a carbon nanocomposite fiber.

    Science.gov (United States)

    Ren, Jing; Bai, Wenyu; Guan, Guozhen; Zhang, Ye; Peng, Huisheng

    2013-11-06

    A flexible and weaveable electric double-layer capacitor wire is developed by twisting two aligned carbon nanotube/ordered mesoporous carbon composite fibers with remarkable mechanical and electronic properties as electrodes. This capacitor wire exhibits high specific capacitance and long life stability. Compared with the conventional planar structure, the capacitor wire is also lightweight and can be integrated into various textile structures that are particularly promising for portable and wearable electronic devices.

  18. Shifting a Quantum Wire through a Disordered Crystal: Observation of Conductance Fluctuations in Real Space

    OpenAIRE

    Heinzel, T.; Salis, G.; Held, R; Luescher, S.; Ensslin, K; Wegscheider, W.; Bichler, M.

    1999-01-01

    A quantum wire is spatially displaced by suitable electric fields with respect to the scatterers inside a semiconductor crystal. As a function of the wire position, the low-temperature resistance shows reproducible fluctuations. Their characteristic temperature scale is a few hundred millikelvin, indicating a phase-coherent effect. Each fluctuation corresponds to a single scatterer entering or leaving the wire. This way, scattering centers can be counted one by one.

  19. Nano-/micro metallic wire synthesis on Si substrate and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Jaskiran, E-mail: kaur.jaskiran@gmail.com; Kaur, Harmanmeet, E-mail: kaur.jaskiran@gmail.com; Singh, Surinder, E-mail: kaur.jaskiran@gmail.com [Department of Physics, Guru Nanak Dev University, Amritsar-143005 (India); Kanjilal, Dinakar [Inter-University Accelerator Centre, New Delhi-110067 (India); Chakarvarti, Shiv Kumar [Manav Rachna International University, Faridabad-121003 (India)

    2014-04-24

    Nano-/micro wires of copper are grown on semiconducting Si substrate using the template method. It involves the irradiation of 8 um thick polymeric layer coated on Si with150 MeV Ni ion beam at a fluence of 2E8. Later, by using the simple technique of electrodeposition, copper nano-/micro wires were grown via template synthesis. Synthesized wires were morphologically characterized using SEM and electrical characterization was carried out by finding I-V plot.

  20. Hypertensive disorders in twin pregnancy

    OpenAIRE

    Santema, Job; Koppelaar, Elin; Wallenburg, Henk

    1995-01-01

    textabstractObjective: To compare the incidence and severity of pregnancy-induced hypertensive disorders in twin pregnancy and in singleton gestation. Study design: Case-control study in the setting of a University Hospital. Each pregnancy of a consecutive series of 187 twin pregnancies attending the antenatal clinic and booked before a gestational age of 24 weeks was matched for maternal age, parity, and gestational age at delivery with a singleton pregnancy delivered in the same year. Prima...

  1. Prediction of grain deformation in drawn copper wire

    Directory of Open Access Journals (Sweden)

    Chang Chao-Cheng

    2015-01-01

    Full Text Available Most copper wire is produced using a drawing process. The crystallographic texture of copper wire, which is strongly associated with grain deformation, can have a profound effect on the formability and mechanical and electrical properties. Thus, the ability to predict grain deformation in drawn copper wire could help to elucidate the evolution of microstructure, which could be highly valuable in product design. This study developed a novel method for predicting grain deformation in drawn copper wire based on finite element simulation with flow net analysis. Simple upsetting tests were conducted to obtain flow stress curves for the simulation of the drawing process. Predictions related to grain deformation were compared with those on the micrographs of the drawn copper wire obtained in experiments. In longitudinal and transverse cross-sections of the drawn wire, the predicted and experiment results presented similar trends involving considerable deformation within the grains. This preliminary study demonstrates the efficacy of the proposed method in providing information useful to the prediction of the grain deformation in drawn copper wire.

  2. Syllabus in Trade Electricity-Electronics. Section II. Trade Electricity.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Occupational Education Curriculum Development.

    This second section of a three-part syllabus for a flexible curriculum in trade electricity-electronics contains four semi-independent units: (1) Advanced Electricity, (2) Residential and Commercial Wiring, (3) Industrial Electricity, and (4) Motor Controls. Introductory sections describe development of the curriculum, outline the total trade…

  3. Hot wire needle probe for thermal conductivity detection

    Energy Technology Data Exchange (ETDEWEB)

    Condie, Keith Glenn; Rempe, Joy Lynn; Knudson, Darrell lee; Daw, Joshua Earl; Wilkins, Steven Curtis; Fox, Brandon S.; Heng, Ban

    2015-11-10

    An apparatus comprising a needle probe comprising a sheath, a heating element, a temperature sensor, and electrical insulation that allows thermal conductivity to be measured in extreme environments, such as in high-temperature irradiation testing. The heating element is contained within the sheath and is electrically conductive. In an embodiment, the heating element is a wire capable of being joule heated when an electrical current is applied. The temperature sensor is contained within the sheath, electrically insulated from the heating element and the sheath. The electrical insulation electrically insulates the sheath, heating element and temperature sensor. The electrical insulation fills the sheath having electrical resistance capable of preventing electrical conduction between the sheath, heating element, and temperature sensor. The control system is connected to the heating element and the temperature sensor.

  4. Miniaturized Linear Wire Ion Trap Mass Analyzer.

    Science.gov (United States)

    Wu, Qinghao; Li, Ailin; Tian, Yuan; Zare, Richard N; Austin, Daniel E

    2016-08-02

    We report a linear ion trap (LIT) in which the electric field is formed by fine wires held under tension and accurately positioned using holes drilled in two end plates made of plastic. The coordinates of the hole positions were optimized in simulation. The stability diagram and mass spectra using boundary ejection were compared between simulation and experiment and good agreement was found. The mass spectra from experiments show peak widths (fwhm) in units of mass-to-charge of around 0.38 Th using a scan rate of 3830 Th/s. The limits of detection are 137 ppbv and 401 ppbv for benzene and toluene, respectively. Different sizes of the wire ion trap can be easily fabricated by drilling holes in scaled positions. Other distinguishing features, such as high ion and photon transmission, low capacitance, high tolerance to mechanical and assembly error, and low weight, are discussed.

  5. The Qingdao Twin Registry: a status update.

    Science.gov (United States)

    Duan, Haiping; Ning, Feng; Zhang, Dongfeng; Wang, Shaojie; Zhang, Dong; Tan, Qihua; Tian, Xiaocao; Pang, Zengchang

    2013-02-01

    In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants of metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes using twin modeling and genome-wide association analysis. Cross-cultural collaborative studies have been carried out between China, Denmark, Finland, and US cohorts. Ongoing data collection and analysis for the Qingdao Twin Registry will be discussed in this article.

  6. Wired to freedom

    DEFF Research Database (Denmark)

    Jepsen, Kim Sune Karrasch; Bertilsson, Margareta

    2017-01-01

    of cochlear implantations among Danish users in order to shed more light on their social and political implications. We situate cochlear implantation in a framework of new life science advances, politics, and user experiences. Analytically, we draw upon the notion of social imaginary and explore the social...... dimension of life science through a notion of public politics adopted from the political theory of John Dewey. We show how cochlear implantation engages different social imaginaries on the collective and individual levels and we suggest that users share an imaginary of being “wired to freedom” that involves...... new access to social life, continuous communicative challenges, common practices, and experiences. In looking at their lives as “wired to freedom,” we hope to promote a wider spectrum of civic participation in the benefit of future life science developments within and beyond the field of Cochlear...

  7. From Wires to Cosmology

    CERN Document Server

    Amin, Mustafa A

    2015-01-01

    We provide a statistical framework for characterizing stochastic particle production in the early universe via a precise correspondence to current conduction in wires with impurities. Our approach is particularly useful when the microphysics is uncertain and the dynamics are complex, but only coarse-grained information is of interest. We study scenarios with multiple interacting fields and derive the evolution of the particle occupation numbers from a Fokker-Planck equation. At late times, the typical occupation numbers grow exponentially which is the analog of Anderson localization for disordered wires. Some statistical features of the occupation numbers show hints of universality in the limit of a large number of interactions and/or a large number of fields. For test cases, excellent agreement is found between our analytic results and numerical simulations.

  8. Twisting wire scanner

    CERN Document Server

    Gharibyan, V; Krouptchenkov, I; Nölle, D; Tiessen, H; Werner, M; Wittenburg, K

    2012-01-01

    A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors is presented.

  9. The Flavor of the Composite Twin Higgs

    CERN Document Server

    Csaki, Csaba; Telem, Ofri; Weiler, Andreas

    2015-01-01

    The assumption of anarchic quark flavor puts serious stress on composite Higgs models: flavor bounds imply a tuning of a few per-mille (at best) in the Higgs potential. Composite twin Higgs (CTH) models significantly reduce this tension by opening up a new region of parameter space, obtained by raising the coupling among the composites close to the strong coupling limit $g_* \\sim 4\\pi$, thereby raising the scale of composites to around 10 TeV. This does not lead to large tuning in the Higgs potential since the leading quantum corrections are canceled by the twin partners (rather than the composites). We survey the leading flavor bounds on the CTH, which correspond to tree-level $\\Delta F=2$ four-Fermi operators from Kaluza-Klein (KK) Z exchange in the kaon system and 1-loop corrections from KK fermions to the electric dipole moment of the neutron. We provide a parametric estimate for these bounds and also perform a numeric scan of the parameter space using the complete calculation for both quantities. The res...

  10. 30 CFR 56.12069 - Lightning protection for telephone wires and ungrounded conductors.

    Science.gov (United States)

    2010-07-01

    ... ungrounded conductors. 56.12069 Section 56.12069 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... NONMETAL MINES Electricity § 56.12069 Lightning protection for telephone wires and ungrounded conductors. Each ungrounded power conductor or telephone wire that leads underground and is directly exposed...

  11. Depositing High-T(sub c) Superconductors On Normal-Conductor Wires

    Science.gov (United States)

    Kirlin, Peter S.

    1994-01-01

    Experiments have demonstrated feasibility of depositing thin layers of high-T(sub c) superconductor on normally electrically conductive wires. Superconductivity evident at and below critical temperature (T{sub c}) of 71 K. OMCVD, organometallic vapor deposition, apparatus coats Ag wire with layer high-T(sub c) superconductor. Superconductive phase of this material formed subsequently by annealing under controlled conditions.

  12. Outlook for China’s Copper Rod& Copper Wire Markets-Part II

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>Along with the implementation of the 12th Five-year Plan,there will be an upsurge of infrastructure construction dominated by electric power,water conservancy and railways.Demand for wire and cable in these sectors will grow.Therefore,China’s imports of wire and cable are expected to rise during2012-2015.

  13. Magnetoconductance of quantum wires

    Science.gov (United States)

    Ferreira, Gerson J.; Sammarco, Filipe; Egues, Carlos

    2010-03-01

    At low temperatures the conductance of a quantum wires exhibit characteristic plate-aus due to the quantization of the transverse modes [1]. In the presence of high in-plane magnetic fields these spin-split transverse modes cross. Recently, these crossings were observed experimentally [2] via measurements of the differential conductance as a function of the gate voltage and the in-plane magnetic-field. These show structures described as either anti-crossings or magnetic phase transitions. Motivated by our previous works on magnetotransport in 2DEGs via the Spin Density Functional Theory (SDFT) [3], here we propose a similar model to investigate the magnetoconductance of quantum wires. We use (i) the SDFT via the Kohn-Sham self-consistent scheme within the local spin density approximation to obtain the electronic structure and (ii) the Landauer-Buettiker formalism to calculate the conductance of a quantum wire. Our results show qualitative agreement with the data of Ref. [2]. [1] B. J. van Wees et al., Phys. Rev. Lett. 60, 848 (1988). [2] A. C. Graham et al., Phys. Rev. Lett. 100, 226804 (2008). [3] H. J. P. Freire, and J. C. Egues, Phys. Rev. Lett. 99, 026801 (2007); G. J. Ferreira, and J. Carlos Egues, J. Supercond. Nov. Mag., in press; G. J. Ferreira, H. J. P. Freire, J. Carlos Egues, submitted.

  14. Estimating twin concordance for bivariate competing risks twin data.

    Science.gov (United States)

    Scheike, Thomas H; Holst, Klaus K; Hjelmborg, Jacob B

    2014-03-30

    For twin time-to-event data, we consider different concordance probabilities, such as the casewise concordance that are routinely computed as a measure of the lifetime dependence/correlation for specific diseases. The concordance probability here is the probability that both twins have experienced the event of interest. Under the assumption that both twins are censored at the same time, we show how to estimate this probability in the presence of right censoring, and as a consequence, we can then estimate the casewise twin concordance. In addition, we can model the magnitude of within pair dependence over time, and covariates may be further influential on the marginal risk and dependence structure. We establish the estimators large sample properties and suggest various tests, for example, for inferring familial influence. The method is demonstrated and motivated by specific twin data on cancer events with the competing risk death. We thus aim to quantify the degree of dependence through the casewise concordance function and show a significant genetic component.

  15. Spina bifida occulta and monozygotic twins.

    Science.gov (United States)

    Spacca, Barbara; Buxton, Neil

    2008-10-01

    Central nervous system maldevelopment can have different presentations in twins. We report on a case of different presentations of spina bifida occulta in monozygotic twins. The first twin presented at birth with a lipomyelomeningocele; a tethered cord was diagnosed in the second twin at 2 years of age. Neural tube defects (NTDs) are a group of common congenital malformations of the brain and spine generated during neurulation. The genetic basis of this process is still not well known. Whenever an NTD is diagnosed in one of a pair of twins, the other twin should also be evaluated for NTDs.

  16. [Twin dystocia: about one case of compaction].

    Science.gov (United States)

    Desseauve, D; Voluménie, J-L

    2008-09-01

    We report a case of twin dystocia during the evacuation of full-term fetus both in cephalic presentation. A low-outlet forceps for second-phase arrest was performed for the first twin but the head remained stuck to maternal perineum, mimicking a shoulder dystocia. Digital examination found a twin compaction, that is the presence of the second twin's fetal head at the level of the first twin's chest. The discrepancy between fetal weights and the use of forceps could favor this rare complication. Various maneuvers were described previously attempted to solve the problem. Forcing back the second head may help to achieve delivery of the first twin.

  17. [The Chinese national twin cohort: an update].

    Science.gov (United States)

    Gao, W J; Li, L M

    2017-06-10

    The importance of large cohort studies in China has been increasingly emphasized. As special group in the population, twins provide excellent natural resources since they share the same birthday, maternal intrauterine environment and early family environment. Twin cohorts are unique for and benefit on controlling the confounding factors as age, gender (same-sex twins), genetic background (monozygotic twins) or early environment (being raised together) in the etiological studies on complex diseases. In this review, we briefly introduce the objectives, current situation, challenges and opportunities related to the Chinese national twin cohort, focusing on the characteristics of twins that are different from other groups in the general population.

  18. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  19. TWIN GESTATION : A CHALLENGING TASK

    Directory of Open Access Journals (Sweden)

    Vrunda V.

    2015-03-01

    Full Text Available INTRODUCTION In the era of modern obstetrics when multiple pregnancies are on increase it is very important to know the incidence and obstetric outcomes of twin deliveries. Twin pregnancy is still associated with increased maternal and perinatal morbidity and mortality as well as healthcare costs . ( 1 , 2 , 3 MATERIALS AND METHODS : This is a r etrospective study of twin deliveries done in the rural medical college teaching hospital over a period of 3 years. RESULTS : During the study period , incidence of twin delivery was 19.37 per 1000 deliveries. Majority cases of twins were young primies in ag e group (20 - 30 years . Preterm delivery occurred in 68% cases and was therefore , the most common morbidity followed by anaemia (38% and PIH (28%. Most common presentation was vertex (66% and malpresentation were present in 44% of cases. 54% were deliver ed by caesarean section. In 88% second baby delivered within 15 minutes. Uterine inertia , PROM , fetal distress , PPH , cord prolapse and abruption were complications during labour. There was no maternal mortality in present study. Average weight of first baby was 1679.63 gms and 2 nd baby was 1586.94 gms. Perinatal mortality of 1 st baby was 27.55 for 1 st baby and 37.25% for 2 nd baby . Average gestational age for patients in whom cervical encirclage was done was 34 weeks. CONCLUSION: P reterm delivery and low birth weight babies are main challenges to the obstetrician. Incidence of LSCS is quite high with malpresentation of leading (twin A baby is a major indication for LSCS . The use of antenatal care services and good intrapartum mana gement will help improve outcome in twin pregnancies.

  20. Characteristics of Electromagnetic Coupling with A Wire through Shielding Enclosure

    Directory of Open Access Journals (Sweden)

    Yanpeng Sun

    2013-09-01

    Full Text Available The paper presents a numerical method based on Finite Difference Time Domain (FDTD in both frequency and time domain for modeling the coupling of an incident electromagnetic pulse(EMP with a conducting wire through a metallic shielding enclosure with a small aperture. Simulation and analysis are done by radius, length, and number of the wires, the incidence angle of EMP and the polaration angle of electric field in consideration. The simulation result shows that interference of the electromagnetic coupling into the shielding enclosure can be affected in different degrees by above factors. At low frequency, the larger the leakage length, the radius or the number of the wire penetrated into the cavity, the more interference is coupled into the shielding cavity from electromagnetic field. Also, the smaller the incident direction angle of propagation of the electromagnetic pulse or the polarization direction angle of the incident electric field, the more easily the electromagnetic interference is coupled into the cavity.

  1. First NASA Workshop on Wiring for Space Applications

    Science.gov (United States)

    Hammond, Ahmad (Compiler); Stavnes, Mark W. (Compiler)

    1994-01-01

    This document contains the proceedings of the First NASA Workshop on Wiring for Space Applications held at NASA Lewis Research Center in Cleveland, OH, July 23-24, 1991. The workshop was sponsored by NASA Headquarters Code QE Office of Safety and Mission Quality, Technical Standards Division and hosted by the NASA Lewis Research Center, Power Technology Division, Electrical Components and Systems Branch. The workshop addressed key technology issues in the field of electrical power wiring for space applications. Speakers from government, industry and academia presented and discussed topics on arc tracking phenomena, wiring applications and requirements, and new candidate insulation materials and constructions. Presentation materials provided by the various speakers are included in this document.

  2. Twin-twin transfusion syndrome: neurodevelopmental screening test

    Directory of Open Access Journals (Sweden)

    Amabile Vessoni Arias

    2015-03-01

    Full Text Available Objective To assess the neurodevelopmental functions (cognition, language and motor function of survivors of twin-twin transfusion syndrome (TTTS. Method Observational cross-sectional study of a total of 67 monochorionic diamniotic twins who underwent fetoscopic laser coagulation (FLC for treatment of TTTS. The study was conducted at the Center for Investigation in Pediatrics (CIPED, Universidade Estadual de Campinas. Ages ranged from one month and four days to two years four months. Bayley Scales of Infant and Toddler Development Screening Test-III, were used for evaluation. Results Most children reached the competent category and were classified as having appropriate performance. The preterm children scored worse than term infants for gross motor subtest (p = 0.036. Conclusion The majority of children reached the expected development according to their age. Despite the good neurodevelopment, children classified at risk should be monitored for development throughout childhood.

  3. TWIN PREGNANCY WITH ACARDIUS ANCEPS

    Directory of Open Access Journals (Sweden)

    Padma

    2014-02-01

    Full Text Available Acardiac twin is an anomaly unique to monochorionic multiple pregnancies, characterized by formation of malformed fetus with an absent or rudimentary (nonfunctional heart. Acardiac twinning, often results from abnormal placental vascular anastomoses. A 20 year old primigravida admitted to the department of Obstetrics and Gynecology S .S. Medical College, Rewa, on 26th July 2012 at the gestation of 34 week with spontaneous monochorionic monoamniotic twin pregnancy and fetal acardius with oligohydramnios. Patient was taking her treatment from private Hospital; acardius was diagnosed at 27 week due to late booking. In view of oligohydramnios and hypoxic changes in color Doppler, elective LSCS was done on 28/7/13 at 34 week 2 day, after betnesol coverage. She delivered a live, healthy, female child with good APGAR score having apparently no congenital anomaly, with a birth weight of 2.3 kg .The other twin was fetus acardius, of about900 gm. with head and face partially developed . Upper limb was rudimentary and lower limb was partially developed and malformed. External genitalia were developed as female. Placenta was monochorionic and monoamniotic, weighing500 gm. The umbilical cord of the normal twin was20 cm with central attachment, while the other umbilical cord was10 cm long with peripheral attachment

  4. TwinMux Testing System

    CERN Document Server

    Wong, Wei Wen; CERN. Geneva. PH Department

    2015-01-01

    During the CERN summer school program, I joined the CMS Muon Drift Tube (DT) group, and mainly worked on two projects, which, both of them, are related to the electronics of a new data concentrator called the “TwinMux”. My first task within the TwinMux project was to build an integrated software test station in order to run several tests on the functionality of the TwinMux hardware. Essentially, I had to integrate existing testing scripts, adding several new ones, into a single user-friendly testing platform which can perform quick, convenient and automated hardware testing. Later, I was also involved in the design of the local technical triggering of the DT. Such system relies on some firmware functionality built in the TwinMux and controlled by software. I had attempted two different approaches to design the communication topology of all the 12 TwinMux cards in order to send a user-defined logical operation to the read-out electronics. The final goal of this system is to drive local trigger signal for...

  5. Reconciling large- and small-scale structure in Twin Higgs models

    Science.gov (United States)

    Prilepina, Valentina; Tsai, Yuhsin

    2017-09-01

    We study possible extensions of the Twin Higgs model that solve the Hierarchy problem and simultaneously address problems of the large- and small-scale structures of the Universe. Besides naturally providing dark matter (DM) candidates as the lightest charged twin fermions, the twin sector contains a light photon and neutrinos, which can modify structure formation relative to the prediction from the ΛCDM paradigm. We focus on two viable scenarios. First, we study a Fraternal Twin Higgs model in which the spin-3/2 baryon \\widehat{Ω}˜ (\\widehat{b}\\widehat{b}\\widehat{b}) and the lepton twin tau \\widehat{τ} contribute to the dominant and subcomponent dark matter densities. A non-decoupled scattering between the twin tau and twin neutrino arising from a gauged twin lepton number symmetry provides a drag force that damps the density inhomogeneity of a dark matter subcomponent. Next, we consider the possibility of introducing a twin hydrogen atom Ĥ as the dominant DM component. After recombination, a small fraction of the twin protons and leptons remains ionized during structure formation, and their scattering to twin neutrinos through a gauged U(1) B-L force provides the mechanism that damps the density inhomogeneity. Both scenarios realize the Partially Acoustic dark matter (PAcDM) scenario and explain the σ 8 discrepancy between the CMB and weak lensing results. Moreover, the self-scattering neutrino behaves as a dark fluid that enhances the size of the Hubble rate H 0 to accommodate the local measurement result while satisfying the CMB constraint. For the small-scale structure, the scattering of \\widehat{Ω} 's and Ĥ's through the twin photon exchange generates a self-interacting dark matter (SIDM) model that solves the mass deficit problem from dwarf galaxy to galaxy cluster scales. Furthermore, when varying general choices of the twin photon coupling, bounds from the dwarf galaxy and the cluster merger observations can set an upper limit on the twin

  6. Hot wire and spark pyrolysis as simple new routes to silicon nanoparticle synthesis

    CSIR Research Space (South Africa)

    Scriba, MR

    2012-11-01

    Full Text Available gases, silane and diborane or silane and phosphine were used. While hot wire pyrolysis always results in multifaceted particles, those produced by spark pyrolysis are spherical. Electrical resistance measurements of compressed powders showed that boron...

  7. Lightweight Metal Rubber Wire and Cable for Space Power Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this NASA STTR program is to produce ultra-lightweight electrical wire and cable harnesses to reduce the liftoff weight of future space flight...

  8. Complications arising in twin pregnancy: findings of prenatal ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Ah; Cho, Jeong Yeon; Lee, Young Ho; Song, Mi Jin; Min, Jee Yeon; Lee, Hak Jong; Han, Byoung Hee; Lee, Kyung Sang; Cho, Byung Jae; Chun, Yi Kyeong [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2003-03-01

    Multifetal gestations are high-risk pregnancies involving higher perinatal morbidity and mortality, and are subject to unique complications including twin oligohydramnios- polyhydramnios sequence, twin-to-twin transfusion syndrome, acardiac twins, conjoined twins, co-twin demise, and heterotopic pregnancies. The purpose of this study is to describe the prenatal ultrasonographic and pathologic findings of these complications.

  9. Radiation-crosslinked polyethylene for wire and cable applications

    Science.gov (United States)

    Ueno, Keiji; Uda, Ikujiro; Tada, Shotaro

    Polyethylene is used as an insulation material for wires and cables because of its excellent electrical properties. Polyethylene is also a typical irradiated crosslinked polymer. The characteristics of irradiated polyethylene, the effects of density, molecular weight and so on, were studied.

  10. Computation of radiation from wire antennas on conducting bodies

    DEFF Research Database (Denmark)

    Albertsen, N. Christian; Hansen, Jesper; Jensen, Niels E.

    1974-01-01

    A theoretical formulation, in terms of combined magnetic and electric field integral equations, is presented for the class of electromagnetic problems in which one or more wire antennas are connected to a conducting body of arbitrary shape. The formulation is suitable for numerical computation...

  11. Microstructure and mechanical behavior of annealed MP35N alloy wire

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M.J.N.V. [School of Engineering, Brown University, Providence, RI 02912 (United States); Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Reiterer, M.W. [Medtronic, PLC, USA, Science and Technology, Minneapolis, MN 55432 (United States); Kumar, K.S., E-mail: Sharvan_Kumar@brown.edu [School of Engineering, Brown University, Providence, RI 02912 (United States)

    2015-06-11

    In a previous paper, the microstructure, monotonic, and cyclic response of as-drawn ~100 μm diameter MP35N low-Ti alloy wire were presented and discussed. In this sequel paper, the effects of annealing the same cold-drawn wire on microstructure and mechanical properties are examined. Specifically, segments of the wire were annealed for 1 h at 973 K, 1023 K, 1073 K, 1123 K and 1173 K in a vacuum furnace. The resulting microstructure was characterized by SEM, EBSD and TEM and compared to the as-drawn microstructure. In-situ heating in the TEM of MP35N ribbon in a similarly cold worked condition enabled corroboration of microstructure evolution during annealing. Annealed wires were tested monotonically and cyclically in uniaxial tension at room temperature, the latter using a stress ratio (R) of 0.3. In addition, the annealed wires were tested cyclically at R=−1 using the rotating beam bending fatigue test. Post-deformation structures and fracture surfaces were characterized using TEM and SEM respectively. Annealing the cold drawn wire results in recrystallization and grain growth; the extent is dependent on the annealing temperature. Deformation twin boundaries in the as-drawn structure illustrate faceted bulging and eventually complete elimination, the microstructure evolving into fine equiaxed grains containing coarser annealing twins with no significant change in texture. Yield strength decreases rapidly with recrystallization to almost half the value of the as-drawn condition, but is accompanied by an increase in modulus (by ~25%) and tensile elongation reaching ~30%. Cyclic response by the way of S–N curves is not enhanced by annealing on an absolute stress scale (due to the loss in yield strength) although the annealed wires are cyclically superior when the stress data are normalized by yield stress.

  12. THERMAL CONDUCTIVITY OF METALLIC WIRES

    Institute of Scientific and Technical Information of China (English)

    LU XIANG; GU JI-HUA; CHU JUN-HAO

    2001-01-01

    The effect of radial thickness on the thermal conductivity of a free standing wire is investigated. The thermal conductivity is evaluated using the Boltzmann equation. A simple expression for the reduction in conductivity due to the increase of boundary scattering is presented. A comparison is made between the experimental results of indium wires and the theoretical calculations. It is shown that this decrease of conductivity in wires is smaller than that in film where heat flux is perpendicular to the surface.

  13. Breast-Feeding Twins: Making Feedings Manageable

    Science.gov (United States)

    ... more than one baby? Here's help breast-feeding twins or other multiples, from getting positioned and ensuring ... babies who are born prematurely, as are many twins and higher order multiples. Breast milk is easier ...

  14. Risk of Oral Clefts in Twins

    DEFF Research Database (Denmark)

    Grosen, Dorthe; Bille, Camilla; Petersen, Inge

    2011-01-01

    BACKGROUND:: Small studies have indicated that twinning increases the risk of oral cleft. METHODS:: We used data from a Danish national population-based cohort study to investigate whether twinning was associated with isolated oral cleft, and to estimate the twin probandwise concordance rate...... and heritability. Twins (207 affected/130,710) and singletons (7766 affected/4,798,526) born from 1936 through 2004 in Denmark were ascertained by linkage among the Danish Facial Cleft Database, the Danish Twin Registry, and the Civil Registration System. We computed oral cleft prevalence and prevalence proportion...... ratio for twins versus singletons, stratified for 3 subphenotypes. Probandwise concordance rates and heritability for twins were estimated for 2 phenotypes-cleft lip with or without cleft palate (CL/P) and cleft palate (CP). RESULTS:: The prevalence of oral cleft was 15.8 per 10,000 twins and 16.6 per...

  15. Having Twins? How to Stay Healthy

    Science.gov (United States)

    ... Listen Español Text Size Email Print Share Having Twins? How to Stay Healthy Page Content Article Body ... the eyes of obstetricians. Many would call a twin pregnancy a high-risk pregnancy , but don’t ...

  16. Nike Twins Seven Seven: Nigerian Batik Artist.

    Science.gov (United States)

    LaDuke, Betty

    1987-01-01

    Chronicles the personal and professional life of Nike Twins Seven Seven (born 1951), a Nigerian batik artist, and her husband, Twins Seven Seven, a musician-artist, both of whom have received international acclaim. (BJV)

  17. Preterm twin gestation and cystic periventricular leucomalacia

    NARCIS (Netherlands)

    Resch, B; Jammernegg, A; Vollaard, E; Maurer, U; Mueller, WD; Pertl, B

    2004-01-01

    Objective: To identify risk factors for the development of cystic periventricular leucomalacia (PVL) in twin gestation. Design: Retrospective case-control study. Setting: Tertiary care university hospital, Department of Paediatrics, Division of Neonatology, Graz, Austria. Patients: Preterm twin gest

  18. Nike Twins Seven Seven: Nigerian Batik Artist.

    Science.gov (United States)

    LaDuke, Betty

    1987-01-01

    Chronicles the personal and professional life of Nike Twins Seven Seven (born 1951), a Nigerian batik artist, and her husband, Twins Seven Seven, a musician-artist, both of whom have received international acclaim. (BJV)

  19. Contribution to advanced hot wire wind sensing

    OpenAIRE

    Kowalski, Lukasz

    2016-01-01

    La consulta íntegra de la tesi, inclos l'article no comunicat públicament per drets d'autor, es pot realitzar prèvia petició a l'Arxiu de la UPC The thermal anemometry is a method which allows to estimate wind magnitude be the mean of measuring heat transfer to the ambient in a forced convection process. For Earth's atmosphere condition, this method is typically applied to the hot wires made of temperature dependent electrical conductor, typically platinum or tungsten, which working with o...

  20. Phenomena at hot-wire electrodes.

    Science.gov (United States)

    Gründler, P

    2000-06-01

    An overview is given describing phenomena at heated microelectrodes where matter and heat energy are simultaneously emitted into the solution. With controlled electric heating, virtual "quiescent" periods as well as ones with constant streaming conditions are found that depend on the heating time. A close look at a permanently heated wire reveals a well defined structure with stationary concentration, temperature and flow rate profiles. The observed phenomena can be utilised for analytical measurements, e.g. with the novel method "Temperature Pulse Voltammetry" (TPV).

  1. Somatosensory Brain Function and Gray Matter Regional Volumes Differ According to Exercise History: Evidence from Monozygotic Twins.

    Science.gov (United States)

    Hautasaari, Pekka; Savić, Andrej M; Loberg, Otto; Niskanen, Eini; Kaprio, Jaakko; Kujala, Urho M; Tarkka, Ina M

    2017-01-01

    Associations between long-term physical activity and cortical function and brain structure are poorly known. Our aim was to assess whether brain functional and/or structural modulation associated with long-term physical activity is detectable using a discordant monozygotic male twin pair design. Nine monozygotic male twin pairs were carefully selected for an intrapair difference in their leisure-time physical activity of at least three years duration (mean age 34 ± 1 years). We registered somatosensory mismatch response (SMMR) in EEG to electrical stimulation of fingers and whole brain MR images. We obtained exercise history and measured physical fitness and body composition. Equivalent electrical dipole sources of SMMR as well as gray matter (GM) voxel counts in regions of interest indicated by source analysis were evaluated. SMMR dipolar source strengths differed between active and inactive twins within twin pairs in postcentral gyrus, medial frontal gyrus and superior temporal gyrus and in anterior cingulate (AC) GM voxel counts differed similarly. Compared to active twins, their inactive twin brothers showed greater dipole strengths in short periods of the deviant-elicited SMMR and larger AC GM voxel counts. Stronger activation in early unattended cortical processing of the deviant sensory signals in inactive co-twins may imply less effective gating of somatosensory information in inactive twins compared to their active brothers. Present findings indicate that already in 30's long-term physical activity pattern is linked with specific brain indices, both in functional and structural domains.

  2. Twins or two single children

    Directory of Open Access Journals (Sweden)

    2002-08-01

    Full Text Available Based on Swedish register data, we compared the influence of a twin birth on the divorce risk with the influence of the sequential birth of two single children. The divorce risk for a woman with a very young child was lower than the risk for women without children or women with children older than 3.5 years. This behaviour was essentially independent of the number of children and whether or not the woman gave birth to twins. The effect of parity was much smaller than the effect of child age. The influence of twins on the divorce risk appeared to fall between that of a first and a second singleton.

  3. Twin TQFTs and Frobenius Algebras

    Directory of Open Access Journals (Sweden)

    Carmen Caprau

    2013-01-01

    Full Text Available We introduce the category of singular 2-dimensional cobordisms and show that it admits a completely algebraic description as the free symmetric monoidal category on a twin Frobenius algebra, by providing a description of this category in terms of generators and relations. A twin Frobenius algebra (C,W,z,z∗ consists of a commutative Frobenius algebra C, a symmetric Frobenius algebra W, and an algebra homomorphism z:C→W with dual z∗:W→C, satisfying some extra conditions. We also introduce a generalized 2-dimensional Topological Quantum Field Theory defined on singular 2-dimensional cobordisms and show that it is equivalent to a twin Frobenius algebra in a symmetric monoidal category.

  4. Subminiature Hot-Wire Probes

    Science.gov (United States)

    Westphal, R. V.; Lemos, F. R.; Ligrani, P. M.

    1989-01-01

    Class of improved subminiature hot-wire flow-measuring probes developed. Smaller sizes yield improved resolution in measurements of practical aerodynamic flows. Probe made in one-wire, two-perpendicular-wire, and three-perpendicular-wire version for measurement of one, two, or all three components of flow. Oriented and positioned on micromanipulator stage and viewed under microscope during fabrication. Tested by taking measurements in constant-pressure turbulent boundary layer. New probes give improved measurements of turbulence quantities near surfaces and anisotropies of flows strongly influence relative errors caused by phenomena related to spatial resolution.

  5. Plasma Formation Around Single Wires

    Science.gov (United States)

    Duselis, Peter U.; Kusse, Bruce R.

    2002-12-01

    At Cornell's Laboratory of Plasma Studies, single wires of various metals were exploded using a ˜250 ns pulser with a rise time of ˜20 A/ns. It was found that the wires first experience a resistive heating phase that lasts 50-80 ns before a rapid collapse of voltage. From that point on, the voltage across the wire was negligible while the current through the wire continued to increase. We attribute this voltage collapse to the formation of plasma about the wire. Further confirmation of this explanation will be presented along with new experimental data describing preliminary spectroscopy results, the expansion rate of the plasma, and current flow along the wire as a function of radius. The resistance of the wire-electrode connection will be shown to significantly affect the energy deposition. Various diagnostics were used to obtain these experiments. Ultraviolet sensitive vacuum photodiodes and a framing camera with an 8 ns shutter were used to detect and measure the width of the visible light emitted by the plasma. A special wire holder was constructed that allowed the transfer of current from the wire to the surrounding plasma to be observed.

  6. Texture development in Galfenol wire

    Science.gov (United States)

    Boesenberg, A. J.; Restorff, J. B.; Wun-Fogle, M.; Sailsbury, H.; Summers, E.

    2013-05-01

    Galfenol (Fe-Ga alloy) wire fabrication provides a low cost alternative to directional solidification methods. This work evaluates the compositional dependence of the wire drawing suitability of Fe-Ga and characterizes the microstructural and magnetic properties of these wires. Wire has been produced with Ga contents between 10 at. % and 17 at. % to allow determination of the ductile to brittle transition (DTBT) in wire manufacture. Published results on chill cast bend specimens indicated that a DTBT occurs at roughly 15 at. % Ga. This DTBT was observed under tensile loading with a corresponding change in fracture behavior from transverse fracture to intergranular fracture. For improved magnetostrictive performance, higher Ga contents are desired, closer to the 17 at. % Ga evaluated in this work. Electron backscattered diffraction B-H loop and resonance measurements as a function of magnetic field (to determine modulus and coupling factor) are presented for as-drawn, furnace, and direct current (DC) annealed wire. Galfenol wire produced via traditional drawing methods is found to have a strong (α) texture parallel to the drawing direction. As-drawn wire was observed to have a lower magnetic permeability and larger hysteresis than DC annealed wire. This is attributed to the presence of a large volume of crystalline defects; such as vacancies and dislocations.

  7. Twins' injuries: genetic and environmental risks / twin research reports / human interest stories.

    Science.gov (United States)

    Segal, Nancy L

    2011-04-01

    The relative contributions of genetic and environmental factors to unintentional injuries are of interest to families with young twins. A recent study found that childhood injuries are explained mostly by child-specific environmental factors. Next, twin research reviews of the association between periodontal disease and cancer, secular trends in gestational age and birthweight, and language development in hearing and deaf co-twins are also summarized. Interesting reports of newborn twins, twin-like relationships, twin interactions and missed twin relationships are presented.

  8. The Fourth International Network of Twin Registries: Overview from Osaka/Research Reviews: Familial Fraternal Twinning; Twin Study of Masculine Faces; Physical Aggression and Epigenetics; Prenatal Education for Parents of Twins/Current Events: 2016 Guinness Book of World Records; Oldest Living Male Twins; Twins Reunited at Sixty-Nine; Panda Twins; Twins.com.

    Science.gov (United States)

    Segal, Nancy L

    2015-12-01

    The 4th International Network of Twin Registries (INTR) Consortium Meeting took place in Osaka, Japan, September 28-29, 2015. The venue was the Osaka Medical Center for Medical Innovation and Translational Research. An overview of presentations and other activities is provided. Next, 1930s research on familial fraternal twinning, preference for masculine faces, physical aggression and epigenetics, and a prenatal education program for parents of multiples are described. Current twin-related events include the 2016 Guinness Book of World Records (GWR), the oldest living male twins, newly reunited twins, the birth of panda twins and a controversial twin-based website.

  9. Do Twin Boundaries Always Strengthen Metal Nanowires?

    OpenAIRE

    Zhang Yongfeng; Huang Hanchen

    2008-01-01

    Abstract It has been widely reported that twin boundaries strengthen nanowires regardless of their morphology—that is, the strength of nanowires goes up as twin spacing goes down. This article shows that twin boundaries do not always strengthen nanowires. Using classical molecular dynamics simulations, the authors show that whether twin boundaries strengthen nanowires depends on the necessary stress for dislocation nucleation, which in turn depends on surface morphologies. When nanowire...

  10. Niobium Titanium and Copper wire samples

    CERN Multimedia

    2009-01-01

    A comparison of the LHC magnet wire that carries 13kA and the equivalent in copper that would be needed to carry such a current. About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC will be the largest superconducting installation ever built and, at 1.9 degrees above absolute zero (300 degrees below room temperature), one of the the coldest objects in the universe! Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9000 niobium–titanium filaments ten times finer than a hair. The cables carry up to 12 500 amps and must withstand enormous electromagnetic forces. At full field, the force on one metre of magnet is comparable to the weight of a jumbo jet. Coil winding requires great care to prevent movements as the field changes. Friction can create hot spots which “quench” the mag...

  11. NA48: Wiring up for Change

    CERN Multimedia

    2001-01-01

    The NA48 Collaboration is rebuilding its drift chambers ready for the experiment to start up again this coming July. An intricate task involving the soldering of over 24,000 wires! The future of the NA48 experiment is coming right down to the wire, that is, the wires which the Collaboration is installing in the clean room of Hall 887 on the Prévessin site. Six days a week, technicians are working in shifts to rebuild the experiment's drift chambers. The original chambers were damaged when a section of a vacuum tube imploded at the end of 1999. A year ago, CERN gave the green light for this essential part of the spectrometer to be rebuilt, so the NA48 experiment, which studies CP violation (see box), still has a bright future ahead of it. Three years of data-taking ahead The NA48 experiment aims to penetrate the secrets of CP (Charge Parity) violation. Charge and parity are two parameters which distinguish a particle from an antiparticle. In other words, an electron possesses a negative electric ...

  12. Wiring regulations in brief

    CERN Document Server

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  13. Twins reunited: scientific and personal perspectives/twin research studies: multiple birth effects on IQ and body size; life style, muscles, and metabolism; monochorionic dizygotic twin with blood chimerism; amniocentesis for twins/twins in the media: identical doctors; freedom fighter for twins; twin scholarships; Auguste and Jean-Felix Piccard; twins born apart.

    Science.gov (United States)

    Segal, Nancy L; Mulligan, Christy A

    2014-04-01

    A reunion of 38-year-old female monozygotic twins took place in Daegu, South Korea, on January 14, 2014. Scientific and personal perspectives on this extraordinary event are provided. A review of timely twin research follows, covering the effects of multiple births on IQ and body size, lifestyle and physical fitness associations, a rare case of a dizygotic twin with blood chimerism and definitional issues surrounding amniocentesis-related loss in multiple birth pregnancies. Interesting and informative mention of twins in the media includes twin doctors, a twin freedom fighter, the availability of college scholarships for twins, a new book about the Piccard family (two of whose members were twins), and co-twins born before and after the new year. A follow-up to a previous mention of identical twin biatheletes is also provided.

  14. Multiple rectal carcinoid tumors in monozygotic twins.

    Science.gov (United States)

    Doi, Momoko; Ikawa, Osamu; Taniguchi, Hiroki; Kawamura, Takuji; Katsura, Kanade

    2016-08-01

    We report multiple rectal carcinoid tumors in monozygotic twins who, respectively, had 42 and 36 carcinoid tumors in the lower rectum. This is the first report about carcinoid tumors in monozygotic twins. Both twins developed a similar number of rectal carcinoids with a similar distribution. Investigation of their genetic background may provide information about the origin of these tumors.

  15. Postpartum Mental State of Mothers of Twins

    Science.gov (United States)

    Brantmüller, Éva; Gyúró, Mónika; Galgán, Kitti; Pakai, Annamária

    2016-01-01

    Twin birth is a relevant risk factor for postnatal depression (PND). The primary objective of our study is to reveal the prevalence of suspected cases of depression and to identify some background factors among mothers of twins. We applied convenience sampling method within a retrospective, quantitative study among mothers given birth to twins for…

  16. A RARE CASE OF ACARDIAC TWIN

    OpenAIRE

    Padmaja; Nirmala,

    2015-01-01

    Fetus Acardiacus is a very rare manifestation of twin gestation . This happens due to TRAP sequence . That is Twin reversed arterial perfusion . In this case an amorphous mass was seen on a routine antenatal scan and followed as there was a live twin also . The case report highlights the importance of careful scanning and ...

  17. MIR phasing using merohedrally twinned crystals

    NARCIS (Netherlands)

    Terwisscha van Scheltinga, Anke C.; Valegård, Karin; Hajdu, Janos; Andersson, Inger

    2003-01-01

    Merohedral twinning is a crystal-growth disorder that seriously hinders the determination of macromolecular crystal structures by isomorphous replacement. The strategies used in the structures solved so far are discussed. Several methods can be used to determine the extent of twinning, the twin frac

  18. Epigenetic Epidemiology of Complex Diseases Using Twins

    DEFF Research Database (Denmark)

    Tan, Qihua

    2013-01-01

    through multiple epigenetic mechanisms. This paper reviews the new developments in using twins to study disease-related epigenetic alterations, links them to lifetime environmental exposure with a focus on the discordant twin design and proposes novel data-analytical approaches with the aim of promoting...... a more efficient use of twins in epigenetic studies of complex human diseases....

  19. [The diagnostic algorithm in twin pregnancy].

    Science.gov (United States)

    Ropacka-Lesiak, Mariola; Szaflik, Krzysztof; Breborowicz, Grzegorz H

    2015-03-01

    This paper presents the diagnostic algorithm in twin pregnancy. The most important sonographic parameters in the assessment of twins have been discussed. Moreover, the most significant complications of twin pregnancy as well as diagnostic possibilities and management, have been also presented and defined.

  20. Natal Influences and Twin Differences: Draft.

    Science.gov (United States)

    Van den Daele, Leland D.

    1972-01-01

    A classification of natal influences is proposed with a model of their operation. Natal influences affect maternal capacity, maternal load, and maternal efficiency. Since maternal load is increased in twin pregnancy, results of twin studies must be generalized with caution. The method of co-twin control is exemplified by examination of a small…

  1. Twin and genetic effects on life events

    NARCIS (Netherlands)

    Middeldorp, C.M.; Cath, D.C.; Vink, J.M.; Boomsma, D.I.

    2005-01-01

    Twin studies that examine the effect of specific environmental risk factors on psychiatric disorders assume that there are no differences in prevalences of these risk factors between twins and singletons. Violation of this assumption signifies that the results from twin studies might not generalize

  2. Concordance for multiple sclerosis in Danish twins

    DEFF Research Database (Denmark)

    Hansen, T; Skytthe, Axel; Stenager, Egon

    2005-01-01

    The occurrence of multiple sclerosis (MS) in twins has not previously been studied in complete nationwide data sets. The existence of almost complete MS and twin registries in Denmark ensures that essentially unbiased samples of MS cases among twins can be obtained. In this population-based study...

  3. The Charles Perkins Centre's Twins Research Node.

    Science.gov (United States)

    Ferreira, Lucas C; Craig, Jeffrey M; Hopper, John L; Carrick, Susan E

    2016-08-01

    Twins can help researchers disentangle the roles of genes from those of the environment on human traits, health, and diseases. To realize this potential, the Australian Twin Registry (ATR), University of Melbourne, and the Charles Perkins Centre (CPC), University of Sydney, established a collaboration to form the Twins Research Node, a highly interconnected research facility dedicated specifically to research involving twins. This collaboration aims to foster the adoption of twin designs as important tools for research in a range of health-related domains. The CPC hosted their Twins Research Node's launch seminar entitled 'Double the power of your research with twin studies', in which experienced twin researchers described how twin studies are supporting scientific discoveries and careers. The launch also featured twin pairs who have actively participated in research through the ATR. Researchers at the CPC were surveyed before the event to gauge their level of understanding and interest in utilizing twin research. This article describes the new Twins Research Node, discusses the survey's main results and reports on the launch seminar.

  4. Corrosion of Wires on Wooden Wire-Bound Packaging Crates

    Science.gov (United States)

    Samuel L. Zelinka; Stan Lebow

    2015-01-01

    Wire-bound packaging crates are used by the US Army to transport materials. Because these crates may be exposed to harsh environments, they are dip-treated with a wood preservative (biocide treatment). For many years, zinc-naphthenate was the most commonly used preservative for these packaging crates and few corrosion problems with the wires were observed. Recently,...

  5. Prosthetic leg powered by MR brake and SMA wires

    Science.gov (United States)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  6. 24 CFR 3285.701 - Electrical crossovers.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Electrical crossovers. 3285.701... URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Electrical Systems and Equipment § 3285.701 Electrical crossovers. Multi-section homes with electrical wiring in more than one section...

  7. Glide twinning and pseudotwinning in peristerite: twin morphology and propagation

    Science.gov (United States)

    Brown, William L.

    1989-07-01

    Optically visible Albite glide “twins” in a peristerite (˜An9Or1.6), identified from their tapering shape and relationship to grain boundaries, were studied by transmission electron microscopy. Near the tips in sections ⊥ a, the microstructure consists of small (˜400 nm long) lensshaped Albite twins centred exclusively on the oligoclase lamellae. The lenses extend partly outwards into the two adjacent low albite lamellae and induce strong inhomogeneous strain. Where the lenses are closer together, they form, depending on the sense of shear, nearly linear left or right-stepping en échelon arrays, with overlap of the strain fields. Slightly farther in from the tip, the twin domains coalesce to form continuous pinch-and-swell lamellae, being always thicker in the oligoclase. Because of Si,Al order, only elastic glide pseudotwins are possible in low albite. In oligoclase glide pseudotwins may be mechanically stable (metastable relative to Si,Al order) and may deviate only slightly from true twins. Pseudotwins develop first in the oligoclase, propagate dynamically by jumping across the intervening albite lamellae, extend lengthways and thicken sideways and finally coalesce. They are stabilized by diffusion-controlled inversion of Si,Al order giving rise to true twins described in a companion paper.

  8. The effect of DC Joule-heating on magnetic structure of conventional amorphous wires

    Science.gov (United States)

    Aştefănoaei, Iordana; Stancu, Alexandru; Chiriac, Horia

    2007-09-01

    In this paper, we determined the effect of DC Joule-heating on magnetic structure of conventional amorphous wires starting from the stresses that appear during preparation process. For a specified value of applied electrical DC current to some amorphous wires, we have analyzed the thermal stresses that appear during the thermal treatment and we calculated the radius of axial magnetic domain (cylindrical inner core) that results after the preparation and annealing processes. We have obtained that: (a) the total stresses (owing to the successive heating, crystallization and cooling) depend strongly on the applied electrical DC current and the radius of the wires; (b) the axial magnetic domain is bigger for the wire having a bigger radius; (c) the cylindrical inner core enlarges significantly after DC Joule-heating; and (d) smaller internal stresses are obtained at smaller values of the wire's radius.

  9. Transport of an arbitrary near-field component with an array of tilted wires

    Energy Technology Data Exchange (ETDEWEB)

    Morgado, Tiago A; Silveirinha, Mario G [Departamento de Engenharia Electrotecnica, Universidade de Coimbra, Instituto de Telecomunicacoes, Polo II, 3030 Coimbra (Portugal)], E-mail: mario.silveirinha@co.it.pt

    2009-08-15

    In this work, we investigate the possibility of near-field transport using an array of tilted metallic wires. It is demonstrated that consistent with the results reported in Belov et al (2006 Phys. Rev. B 73 033108), which describes subwavelength imaging by an array of metallic wires normal to the interface, the setup considered here may enable the transport of the subwavelength details of a given source through an oblique projection. The array of tilted wires permits the transfer of the electric field component parallel to the wires at the image plane, even when there is no electric field normal to interface, and thus the manipulation of other near-field components (i.e. other wave polarizations) that are not accessible with the usual setup of wires normal to the interface. The emergence of negative refraction due to the extreme anisotropy of structured material is also demonstrated.

  10. Soft magnetic wires

    Science.gov (United States)

    Vázquez, M.

    2001-06-01

    An overview of the present state of the art on the preparation techniques, outstanding magnetic properties and applications of soft magnetic micro and nanowires is presented. Rapid solidification techniques (in-rotating-water quenching and drawing methods) to fabricate amorphous microwires with diameter in the range from 100 down to 1 μm are first described. Electrodeposition is also employed to prepare composite microtubes (magnetic coatings) and to fill porous membranes (diameter of the order of 0.1 μm). Magnetic behaviours of interest are related to the different hysteresis loops of samples: square-shaped loops typical of bistable behaviour, and nearly non-hysteretic loop with well-defined transverse anisotropy field. The role played by magnetic dipolar interactions in the magnetic behaviour of arrays of micro and nanowires is described. A particular analysis is done on the giant magnetoimpedance (GMI) effect in the radio and microwave frequency ranges exhibited by ultrasoft microwires. Finally, a few examples of applications are introduced for magnetostrictive and non-magnetostrictive wires, they are: “magnetoelastic pens”, micromotors; DC current-sensors based on GMI, and sharpened amorphous wire tips in spin polarised scanning tunneling microscopy.

  11. NOTE: Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    Science.gov (United States)

    van Gemert, Martin J. C.; Umur, Asli; van den Wijngaard, Jeroen P. H. M.; Van Bavel, Ed; Vandenbussche, Frank P. H. A.; Nikkels, Peter G. J.

    2005-02-01

    An acardiac twin pregnancy is a rare but serious complication of monochorionic twinning and consists of an acardiac twin and a pump twin. The acardiac twin is a severely malformed fetus that lacks most organs, particularly a heart, but grows during pregnancy because it is perfused by the developmentally normal pump twin via a set of arterioarterial and venovenous placental anastomoses. Pump twins die intrauterine or neonatally in about 50% of the cases. Because the effects of an acardiac mass on the pump twin's development are incompletely known, methods for outcome prognosis are currently not available. We sought to derive simple relations for the pump twin's excess cardiac output and decreased oxygenation and to use available clinical cases for a preliminary test of the model. As a method, we used a theoretical flow model to represent the fetoplacental circulation of an acardiac twin pregnancy and estimated blood deoxygenation and reoxygenation following perfusion of the two bodies and placentas, respectively. The results show the pump twin's excess cardiac output and decrease of venous oxygen saturation to depend on the ratio of pump twin to acardiac twin umbilical blood flow, whose ratio can be measured by ultrasonography. The clinical cases show a decreasing umbilical flow ratio with gestation. In conclusion, prospective serial study is necessary to test whether measurement of umbilical flow ratios allows monitoring the pump twin's pathophysiologic development, possibly resulting in a guideline for prognosis of pump twin survival.

  12. Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    Energy Technology Data Exchange (ETDEWEB)

    Gemert, Martin J C van [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Umur, Asli [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Wijngaard, Jeroen P H M van den [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); VanBavel, Ed [Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Vandenbussche, Frank P H A [Department of Obstetrics, Leiden University Medical Center, Leiden (Netherlands); Nikkels, Peter G J [Department of Pathology, University Medical Center, Utrecht (Netherlands)

    2005-02-07

    An acardiac twin pregnancy is a rare but serious complication of monochorionic twinning and consists of an acardiac twin and a pump twin. The acardiac twin is a severely malformed fetus that lacks most organs, particularly a heart, but grows during pregnancy because it is perfused by the developmentally normal pump twin via a set of arterioarterial and venovenous placental anastomoses. Pump twins die intrauterine or neonatally in about 50% of the cases. Because the effects of an acardiac mass on the pump twin's development are incompletely known, methods for outcome prognosis are currently not available. We sought to derive simple relations for the pump twin's excess cardiac output and decreased oxygenation and to use available clinical cases for a preliminary test of the model. As a method, we used a theoretical flow model to represent the fetoplacental circulation of an acardiac twin pregnancy and estimated blood deoxygenation and reoxygenation following perfusion of the two bodies and placentas, respectively. The results show the pump twin's excess cardiac output and decrease of venous oxygen saturation to depend on the ratio of pump twin to acardiac twin umbilical blood flow, whose ratio can be measured by ultrasonography. The clinical cases show a decreasing umbilical flow ratio with gestation. In conclusion, prospective serial study is necessary to test whether measurement of umbilical flow ratios allows monitoring the pump twin's pathophysiologic development, possibly resulting in a guideline for prognosis of pump twin survival. (note)

  13. The 'Planemo' Twins

    Science.gov (United States)

    2006-08-01

    The cast of exoplanets has an extraordinary new member. Using ESO's telescopes, astronomers have discovered an approximately seven-Jupiter-mass companion to an object that is itself only twice as hefty. Both objects have masses similar to those of extra-solar giant planets, but they are not in orbit around a star - instead they appear to circle each other. The existence of such a double system puts strong constraints on formation theories of free-floating planetary mass objects. ESO PR Photo 29a/06 ESO PR Photo 29a/06 Double System of Planetary Mass Objects (Artist's View) Ray Jayawardhana of the University of Toronto (Canada) and Valentin D. Ivanov of ESO report the discovery in the August 3 issue of Science Express, the rapid online publication service of the journal Science. "This is a truly remarkable pair of twins - each having only about one percent the mass of our Sun," said Jayawardhana. "Its mere existence is a surprise, and its origin and fate a bit of a mystery." Roughly half of all Sun-like stars come in pairs. So do about a sixth of brown dwarfs, 'failed stars' that have less than 75 Jupiter masses and are unable to sustain nuclear fusion in their cores. During the past five years, astronomers have identified a few dozen of even smaller free-floating planetary mass objects, or planemos, in nearby star forming regions. Oph 162225-240515, or Oph1622 for short, is the first planemo found to be a double. The researchers discovered the companion candidate in an optical image taken with ESO's 3.5-m New Technology Telescope at La Silla, Chile. They decided to take optical spectra and infrared images of the pair with ESO's 8.2-m Very Large Telescope to make sure that it is a true companion, instead of a foreground or background star that happens to be in the same line of sight. These follow up observations indeed confirmed that both objects are young, at the same distance, and much too cool to be stars. This suggests the two are physically associated. ESO PR

  14. BEPC II wire scanner system

    Institute of Scientific and Technical Information of China (English)

    SUI Yan-Feng; WANG Lin; ZHAO Ying; YUE Jun-Hui; LI Xiao-Ping; CAO Jian-She; MA Li

    2010-01-01

    To monitor the beam profile at the end of the linac non-destructively,a wire scanner as a new diagnostic instrument was designed,manufactured and installed in 2007.Since then,several measurements have been carried out using this device.This paper describes the whole system of the wire scanner and the testing results.

  15. Wire and Packing Tape Sandwiches

    Science.gov (United States)

    Rabinowitz, Sandy

    2009-01-01

    In this article, the author describes how students can combine craft wire with clear packing tape to create a two-dimensional design that can be bent and twisted to create a three-dimensional form. Students sandwich wire designs between two layers of tape. (Contains 1 online resource.)

  16. Epigenetic Epidemiology of Complex Diseases Using Twins

    DEFF Research Database (Denmark)

    Tan, Qihua

    2013-01-01

    In the past decades, studies on twins have had a great impact on dissecting the genetic and environmental contributions to human diseases and complex traits. In the era of functional genomics, the valuable samples of twins help to bridge the gap between gene activity and environmental conditions...... through multiple epigenetic mechanisms. This paper reviews the new developments in using twins to study disease-related epigenetic alterations, links them to lifetime environmental exposure with a focus on the discordant twin design and proposes novel data-analytical approaches with the aim of promoting...... a more efficient use of twins in epigenetic studies of complex human diseases....

  17. The Danish political twin study

    DEFF Research Database (Denmark)

    Klemmensen, Robert; Hobolt, Sara B; Dinesen, Peter Thisted

    2012-01-01

    We compare a recent Danish twin survey on political attitudes and behaviors to a nationally representative survey covering similar topics. We find very similar means and variances for most of our constructed scales of political attitudes and behaviors in the two surveys, although even small...

  18. Twin-Arginine Protein Translocation

    NARCIS (Netherlands)

    Goosens, Vivianne J; van Dijl, Jan Maarten

    2016-01-01

    Twin-arginine protein translocation systems (Tat) translocate fully folded and co-factor-containing proteins across biological membranes. In this review, we focus on the Tat pathway of Gram-positive bacteria. The minimal Tat pathway is composed of two components, namely a TatA and TatC pair, which a

  19. Peltier effect in strongly driven quantum wires

    Science.gov (United States)

    Mierzejewski, M.; Crivelli, D.; Prelovšek, P.

    2014-08-01

    We study a microscopic model of a thermocouple device with two connected correlated quantum wires driven by a constant electric field. In such a closed system we follow the time and position dependence of the entropy density using the concept of the reduced density matrix. At weak driving, the initial changes of the entropy at the junctions can be described by the linear Peltier response. At longer times the quasiequilibrium situation is reached with well defined local temperatures which increase due to an overall Joule heating. On the other hand, a strong electric field induces a nontrivial nonlinear thermoelectric response, e.g., the Bloch oscillations of the energy current. Moreover, we show for the doped Mott insulators that strong driving can reverse the Peltier effect.

  20. Simulation and 'TWINS Observations of the 22 July 2009 Storm

    Science.gov (United States)

    Fok, Mei-Ching; Buzulukova, Natalia Y.; Chen, Sheng-Hsien; Valek, Phil; Goldstein, Jerry; McComas, David

    2010-01-01

    TWINS is the first mission to perform stereo imaging of the Earth's ring current. The magnetic storm on 22 July 2009 is the largest storm observed since TWINS began routine stereo imaging in June 2008. On 22 July 2009, the Dst dropped to nearly -80nT at 7:00 and 10:00 UT. During the main phase and at the peak of the storm, TWINS 1 and 2 were near apogee and moving from pre-dawn to post-dawn local time. The energetic neutral atom (ENA) imagers on the 2 spacecraft captured the storm intensification and the formation of the partial ring current. The peak of the ENA emissions was seen in the midnight-to-dawn local-time sector. The development of this storm has been simulated using the Comprehensive Ring Current Model (CRCM) to understand and interpret the observed signatures. We perform CRCM runs with constant and time-varying magnetic field. The model calculations are validated by comparing the simulated ENA and ion flux intensities with TWINS ENA images and in-situ ion data from THEMIS satellites. Simulation with static magnetic field produces a strong shielding electric field that skews the ion drift trajectories toward dawn. The model's corresponding peak ENA emissions are always eastward than those in the observed TWINS images. On the other hand, simulation with a dynamic magnetic field gives better spatial agreements with both ENA and insitu particle data, suggesting that temporal variations of the geomagnetic field exert a significant influence upon global ring current ion dynamics.