Flexible fiber batteries for applications in smart textiles

NASA Astrophysics Data System (ADS)

Qu, Hang; Semenikhin, Oleg; Skorobogatiy, Maksim

2015-02-01

In this paper, we demonstrate flexible fiber-based Al-NaOCl galvanic cells fabricated using fiber drawing process. Aluminum and copper wires are used as electrodes, and they are introduced into the fiber structure during drawing of the low-density polyethylene microstructured jacket. NaOCl solution is used as electrolyte, and it is introduced into the battery after the drawing process. The capacity of a 1 m long fiber battery is measured to be ˜10 mAh. We also detail assembly and optimization of the electrical circuitry in the energy-storing fiber battery textiles. Several examples of their applications are presented including lighting up an LED, driving a wireless mouse and actuating a screen with an integrated shape-memory nitinol wire. The principal advantages of the presented fiber batteries include: ease of fabrication, high flexibility, simple electrochemistry and use of widely available materials in the battery design.

200-m optical fiber with an integrated electrode and its poling.

PubMed

Lee, Kenneth; Hu, Peifang; Blows, Justin L; Thorncraft, David; Baxter, John

2004-09-15

More than 200 m of germanosilica optical fiber is manufactured with an internal wire electrode running parallel to the core. In this new fabrication method the wire is integrated into the fiber during the draw process. This length of fiber is an order of magnitude longer than other previously reported fibers with internal electrodes. The optical loss is less than our measurement floor of 0.5 dB/m at 1550 nm. A 0.9-m section of the fiber is thermally poled, inducing a permanent second-order nonlinearity of 0.0125 pm/V. Methods to increase the induced nonlinearity are discussed. Integrating the wire into the fiber during the draw allows lengths of fiber with internal electrodes greater than 1 km to be manufactured and subsequently poled.

Development of wire drawing processes for refractory metal fibers

NASA Technical Reports Server (NTRS)

King, G. W.

1972-01-01

Fabrication schedules were developed for producing wire, 0.25 mm to 0.51 mm diameter, from the refractory metal alloys ASTAR-811C, B-88 and W-Hf-C. Tensile properties were evaluated at room temperature and up to 1204 C. Also, the stress rupture properties of the alloys at 1093 C were determined. W-Hf-C and B-88 were found to have the best mechanical properties on a strength to density basis. The fabrication schedules for producing wire from these two alloys were further improved with regards to the wire quality and material yield under the optimization of fabrication schedule.

High strength, low carbon, dual phase steel rods and wires and process for making same

DOEpatents

Thomas, Gareth; Nakagawa, Alvin H.

1986-01-01

A high strength, high ductility, low carbon, dual phase steel wire, bar or rod and process for making the same is provided. The steel wire, bar or rod is produced by cold drawing to the desired diameter in a single multipass operation a low carbon steel composition characterized by a duplex microstructure consisting essentially of a strong second phase dispersed in a soft ferrite matrix with a microstructure and morphology having sufficient cold formability to allow reductions in cross-sectional area of up to about 99.9%. Tensile strengths of at least 120 ksi to over 400 ksi may be obtained.

Microstructures and Mechanical Properties of as-Drawn and Laboratory Annealed Pearlitic Steel Wires

NASA Astrophysics Data System (ADS)

Durgaprasad, A.; Giri, S.; Lenka, S.; Kundu, S.; Mishra, S.; Chandra, S.; Doherty, R. D.; Samajdar, I.

2017-10-01

Near eutectoid fully pearlitic wire rod (5.5 mm diameter) was taken through six stages of wire drawing (drawing strains of 0 to 2.47). The as-drawn (AD) wires were further laboratory annealed (LA) to re-austenitize and reform the pearlite. AD and LA grades, for respective wire diameters, had similar pearlite microstructure: interlamellar spacing ( λ) and pearlite alignment with the wire axis. However, LA grade had lower hardness (for both phases) and slightly lower fiber texture and residual stresses in ferrite. Surprisingly, essentially identical tensile yield strengths in AD and LA wires, measured at equivalent spacing, were found. The work hardened AD had, as expected, higher torsional yield strengths and lower tensile and torsional ductilities than LA. In both wires, stronger pearlite alignment gave significantly increased torsional ductility.

Effects of δ phase and cold drawing ratio on the LCF properties of alloy 718 wire

NASA Astrophysics Data System (ADS)

Jeong, Yong-Kwon; Jo, Chang-Yong; Kim, In-Bae

2000-10-01

The effects of the amount and distribution of δ particles on the low cycle fatigue (LCF) properties of alloy 718 wire were investigated. The amount and distribution of δ particles were controlled by cold drawing followed by a variety of agings. As the cold drawing ratio and aging time at 1116K increased, the well developed granular δ particles increased in amount and their distribution at grain/twin boundaries became more uniform. Regardless of the aging conditions, the LCF life increased as the cold drawing ratio increased. The granular particles precipitated along the grain boundary also improved the LCF life of alloy 718 wire since they inhibited crack propagation. After Merrick heat treatment, 50% of the cold drawn wire displayed lower 698K tensile and yield strength than 30% of the cold drawn wire. This was because the higher strain induced by the cold drawing prior to the first aging at 1116K appeared to promote the precipitation of the δ phase during aging, which has no influence on the strength of the material but has same stoichiometry with the γ phase as Ni3Nb and, as a result, the higher strain precipitated a smaller quantity of γ particles with subsequent aging, which is a major hardening phase of the alloy. Cold drawing also lowered the precipitation temperature of the δ phase.

Analysis of Fatigue Crack Paths in Cold Drawn Pearlitic Steel

PubMed Central

Toribio, Jesús; González, Beatriz; Matos, Juan-Carlos

2015-01-01

In this paper, a fracto-metallographic analysis was performed on the cracked specimens of cold drawn pearlitic steel subjected to fatigue tests. Fatigue cracks are transcollonial and exhibit a preference for fracturing pearlitic lamellae, with non-uniform crack opening displacement values, micro-discontinuities, branchings, bifurcations and frequent local deflections that create microstructural roughness. At the micro-level, the cold drawn pearlitic steel exhibits higher micro-roughness than the hot rolled bar (this is a consequence of the manufacturing process by cold drawing), so that the actual fractured surface in the cold drawn wire is greater than that in the hot rolled bar, due to the fact that the crack deflection events are more frequent and with higher angle in the former (the heavily drawn prestressing steel wire). These findings show the relevant role on the manufacturing process by cold drawing in the fatigue crack propagation in pearlitic steel. PMID:28793647

Analysis of Fatigue Crack Paths in Cold Drawn Pearlitic Steel.

PubMed

Toribio, Jesús; González, Beatriz; Matos, Juan-Carlos

2015-11-04

In this paper, a fracto-metallographic analysis was performed on the cracked specimens of cold drawn pearlitic steel subjected to fatigue tests. Fatigue cracks are transcollonial and exhibit a preference for fracturing pearlitic lamellae, with non-uniform crack opening displacement values, micro-discontinuities, branchings, bifurcations and frequent local deflections that create microstructural roughness. At the micro-level, the cold drawn pearlitic steel exhibits higher micro-roughness than the hot rolled bar (this is a consequence of the manufacturing process by cold drawing), so that the actual fractured surface in the cold drawn wire is greater than that in the hot rolled bar, due to the fact that the crack deflection events are more frequent and with higher angle in the former (the heavily drawn prestressing steel wire). These findings show the relevant role on the manufacturing process by cold drawing in the fatigue crack propagation in pearlitic steel.

Study of thermomechanical treatment on mechanical-induced phase transformation of NiTi and TiNiCu wires.

PubMed

Seyyed Aghamiri, S M; Nili Ahmadabadi, M; Shahmir, H; Naghdi, F; Raygan, Sh

2013-05-01

The nickel-titanium shape memory alloys have been used in orthodontic application due to their unique properties like superelasticity and biocompatibility. The phase transformation behavior of these alloys can be changed by alloying elements and thermomechanical processing conditions. In this study, two types of NiTi and TiNiCu wires of 0.4mm diameter were produced via thermomechanical treatments with final step of 20% cold drawing followed by annealing at different temperatures of 300 and 400 °C for varying times of 10, 30 and 60 min. The processed wires were characterized by oral cavity configuration three point bending (OCTPB) test at 37 °C to specify the mechanical transformation features. Also, differential scanning calorimetry (DSC) was used to analyze the thermal transformation temperatures of selected wires. The results showed the thermomechanical treatment at 300 °C for 30 min was the suitable process in terms of superelasticity and transformation temperatures for orthodontic application. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nanowire and microwire fabrication technique and product

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

Sumant, Anirudha V.; Zach, Michael; Marten, Alan David

A continuous or semi-continuous process for fabricating nanowires or microwires makes use of the substantially planar template that may be moved through electrochemical solution to grow nanowires or microwires on exposed conductive edges on the surface of that template. The planar template allows fabrication of the template using standard equipment and techniques. Adhesive transfer may be used to remove the wires from the template and in one embodiment to draw a continuous wire from the template to be wound around the drum.

Development of termination and utilization concepts for flat conductor cables. Volume 3: Cost study comparison, flat versus round conductor cable

NASA Technical Reports Server (NTRS)

1972-01-01

A cost study comparing flat conductor cable (FCC) with small-gage wire (SGW) and conventional round conductor cable (RCC) is presented. This study was based on a vehicle wiring system consisting of 110,000 ft of conventional RCC equally divided between AWG sizes 20,22, and 24 using MIL-W-81044-type wire and MIL-C-26500 circular connectors. Basic cost data were developed on a similar-sized commercial jet airplane wiring system on a previous company R&D program in which advanced wiring techniques were carried through equivalent installations on an airplane mockup; and on data developed on typical average bundles during this program. Various cost elements included were engineering labor, operations (manufacturing) labor, material costs, and cost impact on payload. Engineering labor includes design, wiring system integration, wiring diagrams and cable assembly drawings, wire installations, and other related supporting functions such as the electronic data processing for the wiring. Operations labor includes mockup, tooling and production planning, fabrication, assembly, installation, and quality control cost impact on payload is the conversion of wiring system weight variations through use of different wiring concepts to program payload benefits in terms of dollars.

The Work Softening Behavior of Pure Mg Wire during Cold Drawing.

PubMed

Sun, Liuxia; Bai, Jing; Xue, Feng; Chu, Chenglin; Meng, Jiao

2018-04-13

We performed multiple-pass cold drawing for pure Mg wire which showed excellent formability (~138% accumulative true strain) at room temperature. Different from the continuous work hardening occurring during cold drawing of Mg alloy wires, for pure Mg, an initially rapid increase in hardness and strength was followed by significant work softening and finally reached a steady-state level, approximately 40~45 HV. The work softening can be attributed to the dynamic recovery and recrystallization of pure Mg at room temperature. Meanwhile, an abrupt change in texture component also was detected with the transition from work hardening to softening in the strain range of 28~34%. During the whole drawing, the strongest texture component gradually transformed from as-extruded basal to <10 1 ¯ 0> fiber (~28% accumulative true strain), and then rapidly returned to the weak basal texture.

Development of ultrafine-grained microstructure in Al-Cu-Mg alloy through equal-channel angular pressing

NASA Astrophysics Data System (ADS)

Sai Anuhya, Danam; Gupta, Ashutosh; Nayan, Niraj; Narayana Murty, S. V. S.; Manna, R.; Sastry, G. V. S.

2014-08-01

Al-Cu-Mg alloys are extensively used for riveting applications in aerospace industries due to their relatively high shear strength coupled with high plasticity. The significant advantage of using V65 aluminum alloy ((Al-4Cu-0.2Mg) for rivet application also stems from its significantly slower natural aging kinetics, which gives operational flexibility to carryout riveting operation even after 4 days of solution heat treatment, in contrast to its equivalent alloy AA2024.Rivets are usually made by cold heading of wire rods. In order to form a defect free rivet head, grain size control in wire rods is essential at each and every stage of processing right from casting onwards upto the final wire drawing stage. Wire drawing is carried out at room temperature to reduce diameter as well as impart good surface finish. In the present study, different microstructures in V65 alloy bars were produced by rolling at different temperatures (room temperature to 523K) and subsequently deformed by equal channel angular pressing (ECAP) at 423K upto an equivalent strain of 7. ECAP was carried out to study the effect of initial microstructure on grain refinement and degree of deformation on the evolution of ultrafine grain structure. The refinement of V65 alloy by ECAP is significantly influenced by Initial microstructure but amount of deformation strongly affects the evolution processes as revealed by optical microscopy and transmission electron microscopy.

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

NASA Astrophysics Data System (ADS)

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 <111> and minor <100> duplex fiber texture. However, the <111> 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.

Fine-Filament MgB2 Superconductor Wire

NASA Technical Reports Server (NTRS)

Cantu, Sherrie

2015-01-01

Hyper Tech Research, Inc., has developed fine-filament magnesium diboride (MgB2) superconductor wire for motors and generators used in turboelectric aircraft propulsion systems. In Phase I of the project, Hyper Tech demonstrated that MgB2 multifilament wires (<10 micrometers) could reduce alternating current (AC) losses that occur due to hysteresis, eddy currents, and coupling losses. The company refined a manufacturing method that incorporates a magnesium-infiltration process and provides a tenfold enhancement in critical current density over wire made by a conventional method involving magnesium-boron powder mixtures. Hyper Tech also improved its wire-drawing capability to fabricate fine multifilament strands. In Phase II, the company developed, manufactured, and tested the wire for superconductor and engineering current density and AC losses. Hyper Tech also fabricated MgB2 rotor coil packs for a superconducting generator. The ultimate goal is to enable low-cost, round, lightweight, low-AC-loss superconductors for motor and generator stator coils operating at 25 K in next-generation turboelectric aircraft propulsion systems.

Improvement of the Mechanical Properties of 1022 Carbon Steel Coil by Using the Taguchi Method to Optimize Spheroidized Annealing Conditions.

PubMed

Yang, Chih-Cheng; Liu, Chang-Lun

2016-08-12

Cold forging is often applied in the fastener industry. Wires in coil form are used as semi-finished products for the production of billets. This process usually requires preliminarily drawing wire coil in order to reduce the diameter of products. The wire usually has to be annealed to improve its cold formability. The quality of spheroidizing annealed wire affects the forming quality of screws. In the fastener industry, most companies use a subcritical process for spheroidized annealing. Various parameters affect the spheroidized annealing quality of steel wire, such as the spheroidized annealing temperature, prolonged heating time, furnace cooling time and flow rate of nitrogen (protective atmosphere). The effects of the spheroidized annealing parameters affect the quality characteristics of steel wire, such as the tensile strength and hardness. A series of experimental tests on AISI 1022 low carbon steel wire are carried out and the Taguchi method is used to obtain optimum spheroidized annealing conditions to improve the mechanical properties of steel wires for cold forming. The results show that the spheroidized annealing temperature and prolonged heating time have the greatest effect on the mechanical properties of steel wires. A comparison between the results obtained using the optimum spheroidizing conditions and the measures using the original settings shows the new spheroidizing parameter settings effectively improve the performance measures over their value at the original settings. The results presented in this paper could be used as a reference for wire manufacturers.

7 CFR 1755.506 - Aerial wire services

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 11 2011-01-01 2011-01-01 false Aerial wire services 1755.506 Section 1755.506... § 1755.506 Aerial wire services (a) Aerial services of one through six pairs shall consist of Service...), Specifications and Drawings for Service Installations at Customer Access Locations. The wire used for aerial...

Method of preparing composite superconducting wire

DOEpatents

Verhoeven, John D.; Gibson, Edwin D.; Finnemore, Douglas K.; Ostenson, Jerome E.; Schmidt, Frederick A.; Owen, Charles V.

1985-08-06

An improved method of preparing composite multifilament superconducting wire of Nb.sub.3 Sn in a copper matrix which eliminates the necessity of coating the drawn wire with tin. A generalized cylindrical billet of an alloy of copper containing at least 15 weight percent niobium, present in the copper as discrete, randomly distributed and oriented dendritic-shaped particles, is provided with at least one longitudinal opening which is filled with tin to form a composite drawing rod. The drawing rod is then drawn to form a ductile composite multifilament wire containing a filament of tin. The ductile wire containing the tin can then be wound into magnet coils or other devices before heating to diffuse the tin through the wire to react with the niobium forming Nb.sub.3 Sn. Also described is an improved method for making large billets of the copper-niobium alloy by consumable-arc casting.

Improved method of preparing composite superconducting wire

DOEpatents

Verhoeven, J.D.; Gibson, E.D.; Finnemore, D.K.; Ostenson, J.E.; Schmidt, F.A.; Owen, C.V.

1979-10-17

An improved method of preparing composite multifilament superconducting wire of Nb/sub 3/Sn in a copper matrix eliminates the necessity of coating the drawn wire with tin. A generalized cylindrical billet of an alloy of copper containing at least 15 weight percent niobium, present in the copper as discrete, randomly distributed and oriented dendritic-shaped particles, is provided with at least one longitudinal opening which is filled with tin to form a composite drawing rod. The drawing rod is then drawn to form a ductile composite multifilament wire containing a filament of tin. The ductile wire containing the tin can then be wound into magnet coils or other devices before heating to diffuse the tin through the wire to react with the niobium forming Nb/sub 3/Sn. Also described is an improved method for making large billets of the copper-niobium alloy by consumable-arc casting.

Fabrication and evaluation of low fiber content alumina fiber/aluminum composites

NASA Technical Reports Server (NTRS)

Hack, J. E.; Strempek, G. C.

1980-01-01

The mechanical fabrication of low volume percent fiber, polycrystalline alumina fiber reinforced aluminum composites was accomplished. Wire preform material was prepared by liquid-metal infiltration of alumina fiber bundles. The wires were subsequently encapsulated with aluminum foil and fabricated into bulk composite material by hot-drawing. Extensive mechanical, thermal and chemical testing was conducted on preform and bulk material to develop a process and material data base. In addition, a preliminary investigation of mechanical forming of bulk alumina fiber reinforced aluminum composite material was conducted.

Efficacy of Tantalum Tungsten Alloys for Diffusion Barrier Applications

NASA Astrophysics Data System (ADS)

Smathers, D. B.; Aimone, P. R.

2017-12-01

Traditionally either Niobium, Tantalum or a combination of both have been used as diffusion barriers in Nb3Sn Multi-filament wire. Vanadium has also been used successfully but the ultimate RRR of the copper is limited unless an external shell of Niobium is included. Niobium is preferred over Tantalum when alternating current losses are not an issue as the Niobium will react to form Nb3Sn. Pure Tantalum tends to deform irregularly requiring extra starting thickness to ensure good barrier qualities. Our evaluations showed Tantalum lightly alloyed with 3 wt% Tungsten is compatible with the wire drawing process while deforming as well as or better than pure Niobium. Ta3wt%W has been processed as a single barrier and as a distributed barrier to fine dimensions. In addition, the higher modulus and strength of the Tantalum Tungsten alloy improves the overall tensile properties of the wire.

The influence of drawing parameters on the mechanical properties of two beta-titanium alloys.

PubMed

Shastry, C V; Goldberg, A J

1983-10-01

The total cold reduction and reduction per pass used during the drawing of fine wires affected the mechanical properties of two beta-titanium alloys. Both Ti-11.5Mo-6Zr-4.5Sn and Ti-13V-11Cr-3Al showed increased yield strengths and low moduli of elasticity, which resulted in wires appropriate for orthodontic application.

Hydrostatic Microextrusion of Steel and Copper

NASA Astrophysics Data System (ADS)

Berti, Guido; Monti, Manuel; D'Angelo, Luciano

2011-05-01

The paper presents an experimental investigation based on hydrostatic micro extrusion of billets in low carbon steel and commercially pure copper, and the relevant results. The starting billets have a diameter of 0.3 mm and are 5 mm long; a high pressure generator consisting of a manually operated piston screw pump is used to pressurize the fluid up to 4200 bar, the screw pump is connected through a 3-way distribution block to the extrusion die and to a strain gauge high pressure sensor. The sensor has a full scale of 5000 bar and the extrusion pressure is acquired at a sampling rate of 2 kHz by means of an acquisition program written in the LabVIEW environment. Tests have been conducted at room temperature and a lubricant for wire drawing (Chemetall Gardolube DO 338) acts both as the pressurizing fluid and lubricant too. In addition, billets were graphite coated. Different fluid pressures and process durations have been adopted, resulting in different extrusion lengths. The required extrusion pressure is much higher than in non-micro forming operations (this effect is more evident for steel). On the cross section of the extruded parts, hardness and grain size distribution have been measured, the former through Vickers micro hardness (10 g load) tests. In the case of the extrusion of copper, the material behaves as in microdrawing process. In the case of the extrusion of steel, the hardness increases from the core to the surface as in the drawing process, but with lower values. The analysis evidenced the presence of the external layer, but its thickness is about 1/3 of the external layer in the drawn wire and the grains appear smaller than in the layer of the drawn wire. The extruding force required along the extruding direction is higher (22-24 N) than the drawing force along the same direction (12 N): being the material, the reduction ratio, the die sliding length the same in both cases, the higher extrusion force should be caused by a higher tangential friction force and/or a higher redundant work of deformation and/or a different material behaviour. Which is the real mechanism is not clear at present, but surface layer grains in extrusion are more deformed than in wire drawing. For this reason the deformation inhomogeneity increases in extrusion and the material under the highly deformed surface layer should be subjected to lower strains, strain hardening and finally resulting in lower hardness.

Hydrostatic Microextrusion of Steel and Copper

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

Berti, Guido; Monti, Manuel; D'Angelo, Luciano

2011-05-04

The paper presents an experimental investigation based on hydrostatic micro extrusion of billets in low carbon steel and commercially pure copper, and the relevant results. The starting billets have a diameter of 0.3 mm and are 5 mm long; a high pressure generator consisting of a manually operated piston screw pump is used to pressurize the fluid up to 4200 bar, the screw pump is connected through a 3-way distribution block to the extrusion die and to a strain gauge high pressure sensor. The sensor has a full scale of 5000 bar and the extrusion pressure is acquired at amore » sampling rate of 2 kHz by means of an acquisition program written in the LabVIEW environment. Tests have been conducted at room temperature and a lubricant for wire drawing (Chemetall Gardolube DO 338) acts both as the pressurizing fluid and lubricant too. In addition, billets were graphite coated. Different fluid pressures and process durations have been adopted, resulting in different extrusion lengths. The required extrusion pressure is much higher than in non-micro forming operations (this effect is more evident for steel). On the cross section of the extruded parts, hardness and grain size distribution have been measured, the former through Vickers micro hardness (10 g load) tests. In the case of the extrusion of copper, the material behaves as in microdrawing process. In the case of the extrusion of steel, the hardness increases from the core to the surface as in the drawing process, but with lower values. The analysis evidenced the presence of the external layer, but its thickness is about 1/3 of the external layer in the drawn wire and the grains appear smaller than in the layer of the drawn wire. The extruding force required along the extruding direction is higher (22-24 N) than the drawing force along the same direction (12 N): being the material, the reduction ratio, the die sliding length the same in both cases, the higher extrusion force should be caused by a higher tangential friction force and/or a higher redundant work of deformation and/or a different material behaviour. Which is the real mechanism is not clear at present, but surface layer grains in extrusion are more deformed than in wire drawing. For this reason the deformation inhomogeneity increases in extrusion and the material under the highly deformed surface layer should be subjected to lower strains, strain hardening and finally resulting in lower hardness.« less

Mechanical properties and aesthetics of FRP orthodontic wire fabricated by hot drawing.

PubMed

Imai, T; Watari, F; Yamagata, S; Kobayashi, M; Nagayama, K; Toyoizumi, Y; Nakamura, S

1998-12-01

The FRP wires 0.5 mm in diameter with a multiple fiber structure were fabricated by drawing the fiber polymer complex at 250 degrees C for an esthetic, transparent orthodontic wire. Biocompatible CaO-P2O5-SiO2-Al2O3 (CPSA) glass fibers of 8-20 microm in diameter were oriented unidirectionally in the longitudinal direction in PMMA matrix. The mechanical properties were investigated by 3-point flexural test. The FRP wire showed sufficient strength and a very good elastic recovery after deformation. Young's modulus and the flexural load at deflection 1 mm were nearly independent of the fiber diameter and linearly increased with the fiber fraction. The dependence on fiber fraction obeys well the rule of mixture. This FRP wire could cover the range of strength corresponding to the conventional metal orthodontic wires from Ni-Ti used in the initial stage of orthodontic treatments to Co-Cr used in the final stage by changing the volume ratio of glass fibers with the same external diameter. The estheticity in external appearance was excellent. Thus the new FRP wire can satisfy both mechanical properties necessary for an orthodontic wire and enough estheticity, which was not possible for the conventional metal wire.

Microstructural Development and Control in Liquid Phase Sintering; Processing, Structures and Properties of Cold Worked Metal Matrix Composites

DTIC Science & Technology

1984-06-03

between them in a composite develops in a manner consistent with the macroscopic axisymmetric deformation of wire drawing or swaging. Additionally, for...spacing) V 0 bo :vsii~f:- nikel omposit’es 0.5 -~ ................................*. . C pper-7chrorhium c2o * - - 0 0 C -io~omposites ~ :13 Nickeil

The Effect of Sintering Temperature on The Rolled Silver-Sheathed Monofilament Bi,Pb-Sr-Ca-Cu-O Superconducting Wire

NASA Astrophysics Data System (ADS)

Hendrik; Sebleku, P.; Siswayanti, B.; Pramono, A. W.

2017-05-01

The manufacture of high critical temperature (Tc) Bi, Pb-Sr-Ca-Cu-O (HTS BPSCCO) superconductor wire fabricated by power-in-tube (PIT) is a multi-step process. The main difficulty is that the value of Tc superconductor wire determined by various factors for each step. The objective of this research is to investigate the effect of sintering parameters on the properties of final rolled material. The fabrication process of 1 m rolled-silver sheath monofilament superconductor BPSCCO wire using mechanical deformation process including rolling and drawing has been carried out. The pure silver powders were melted and formed into pure silver (Ag) tube. The tube was 10 mm in diameter with a sheath material: superconductor powders ratio of about 6 : 1. Starting powders, containing the nominal composition of Bi2-Sr2-Cam-1-Cum-Oy, were inserted into the pure silver tube and rolled until it reached a diameter of 4 mm. A typical area reduction ratio of about 5% per step has been proposed to prevent microcracking during the cold-drawing process. The process of rolling of the silver tube was subsequently repeated to obtain three samples and then followed by heat-treated at 820 °C, 840 °C, and 860 °C, respectively. The surface morphology was analyzed by using SEM; the crystal structure was studied by using X-RD, whereas the superconductivity was investigated by using temperature dependence resistivity measurement by using four-point probe technique. SEM images showed the porosity of the cross-sectional surface of the samples. The sample with low heating temperature showed porosity more than the one with high temperature. The value of critical temperature (Tc) of the sample with a dwelling time of heating of 8 hours is 70 K. At above 70 K, it shows the behavior of conductor properties. However, the porosity increased as the heating time increased up to 24 hours. The critical temperature was difficult to be identified due to its porosity. According to XRD results, the Bi-2212 phase is prominent in all samples.

Zn-Li alloy after extrusion and drawing: Structural, mechanical characterization, and biodegradation in abdominal aorta of rat.

PubMed

Zhao, Shan; Seitz, Jan-M; Eifler, Rainer; Maier, Hans J; Guillory, Roger J; Earley, Elisha J; Drelich, Adam; Goldman, Jeremy; Drelich, Jaroslaw W

2017-07-01

Zinc shows great promise as a bio-degradable metal. Our early in vivo investigations implanting pure zinc wires into the abdominal aorta of Sprague-Dawley rats revealed that metallic zinc does not promote restenotic responses and may suppress the activities of inflammatory and smooth muscle cells. However, the low tensile strength of zinc remains a major concern. A cast billet of the Zn-Li alloy was produced in a vacuum induction caster under argon atmosphere, followed by a wire drawing process. Two phases of the binary alloy identified by x-ray diffraction include the zinc phase and intermetallic LiZn 4 phase. Mechanical testing proved that incorporating 0.1wt% of Li into Zn increased its ultimate tensile strength from 116±13MPa (pure Zn) to 274±61MPa while the ductility was held at 17±7%. Implantation of 10mm Zn-Li wire segments into abdominal aorta of rats revealed an excellent biocompatibility of this material in the arterial environment. The biodegradation rate for Zn-Li was found to be about 0.008mm/yr and 0.045mm/yr at 2 and 12months, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Composite superconducting wires obtained by high-rate tinning in molten Bi-Pb-Sr-Ca-Cu-O system

NASA Technical Reports Server (NTRS)

Grozav, A. D.; Konopko, L. A.; Leporda, N. I.

1990-01-01

The preparation of high-T(sub c) superconducting long composite wires by short-time tinning of the metal wires in a molten Bi-Pb-Sr-Ca-Cu-O compound is discussed. The application of this method to the high-T(sub c) materials is tested, possibly for the first time. The initial materials used for this experiment were ceramic samples with nominal composition Bi(1.5)Pb(0.5)Sr2Ca2Cu3O(x) and T(sub c) = 80 K prepared by the ordinary solid-state reaction, and industrial copper wires from 100 to 400 microns in diameter and from 0.5 to 1 m long. The continuously moving wires were let through a small molten zone (approximately 100 cubic mm). The Bi-based high-T(sub c) ceramics in a molten state is a viscous liquid and it has a strongly pronounced ability to spread on metal wire surfaces. The maximum draw rate of the Cu-wire, at which a dense covering is still possible, corresponds to the time of direct contact of wire surfaces and liquid ceramics for less than 0.1 s. A high-rate draw of the wire permits a decrease in the reaction of the oxide melt and Cu-wire. This method of manufacture led to the fabrication of wire with a copper core in a dense covering with uniform thickness of about h approximately equal to 5 to 50 microns. Composite wires with h approximately equal to 10 microns (h/d approximately equal to 0.1) sustained bending on a 15 mm radius frame without cracking during flexing.

Method for making an elastomeric member with end pieces

DOEpatents

Hoppie, L.O.; McNinch, J.H. Jr.; Nowell, G.C.

1984-10-23

A molding process is described for molding an elongated elastomeric member with wire mesh sleeves bonded to the ends. A molding preform of elastomeric material is positioned within a seamless mold cylinder, and the open ends of the wire mesh sleeves are mounted to end plug assemblies slidably received into the mold cylinder and positioned against the ends of the preform. A specialized profile is formed into surfaces of the respective end plug assemblies and by heating of the mold, the ends of the elastomeric preform are molded to the profile, as well as bonded to the reinforcing wire mesh sleeves. Vacuum is applied to the interior of the mold to draw outgassing vapors through relief spaces there through. The completed elastomeric member is removed from the mold cylinder by stretching, the consequent reduction in diameter enabling ready separation from the mold cylinder and removal thereof. 9 figs.

An interactive wire-wrap board layout program

NASA Technical Reports Server (NTRS)

Schlutsmeyer, A.

1987-01-01

An interactive computer-graphics-based tool for specifying the placement of electronic parts on a wire-wrap circuit board is presented. Input is a data file (currently produced by a commercial logic design system) which describes the parts used and their interconnections. Output includes printed reports describing the parts and wire paths, parts counts, placement lists, board drawing, and a tape to send to the wire-wrap vendor. The program should reduce the engineer's layout time by a factor of 3 to 5 as compared to manual methods.

A Study Into the Mechanism(s) for the Electroplastic Effect in Metals and Its Application to Metalworking, Processing and Fatigue

DTIC Science & Technology

1989-03-10

Regarding metal processing , exploratory studies established that electropulsing (1 105 A/cm2 , - 100 lts duration and - 2 pulses per s) reduced the force...required for 3 drawing Cu wire and enhanced the rates of recovery and recrystallization of cold worked Cu [19] and the rate of sintering of Al powder...h£~A .2 3 o9o./7-t, s A STUDY INTO THE MECHANISM(S) FOR THE ELECTROPLASTIC EFFECT IN METALS AND ITS APPLICATION TO METALWORKING, PROCESSING AND

Effect of Thermomechanical Processing on the Microstructure, Properties, and Work Behavior of a Ti50.5 Ni29.5 Pt20 High-Temperature Shape Memory Alloy

NASA Technical Reports Server (NTRS)

Noebe, Ronald; Draper, Susan; Gaydosh, Darrell; Garga, Anita; Lerch, Brad; Penney, Nicholas; Begelow, Glen; Padula, Santo, II; Brown, Jeff

2006-01-01

TiNiPt shape memory alloys are particularly promising for use as solid state actuators in environments up to 300 C, due to a reasonable balance of properties, including acceptable work output. However, one of the challenges to commercializing a viable high-temperature shape memory alloy (HTSMA) is to establish the appropriate primary and secondary processing techniques for fabrication of the material in a required product form such as rod and wire. Consequently, a Ti(50.5)Ni(29.5)Pt20 alloy was processed using several techniques including single-pass high-temperature extrusion, multiple-pass high-temperature extrusion, and cold drawing to produce bar stock, thin rod, and fine wire, respectively. The effects of heat treatment on the hardness, grain size, room temperature tensile properties, and transformation temperatures of hot- and cold-worked material were examined. Basic tensile properties as a function of temperature and the strain-temperature response of the alloy under constant load, for the determination of work output, were also investigated for various forms of the Ti(50.5)Ni(29.5)Pt20 alloy, including fine wire.

Superconducting wire manufactured

NASA Astrophysics Data System (ADS)

Fu, Yuexian; Sun, Yue; Xu, Shiming; Peng, Ying

1985-10-01

The MF Nb/Cu Extrusion Tube Method was used to manufacture 3 kg of stable practical MF Nb2Sn composite superconducting wire containing pure Cu(RRR approx. 200)/Ta. The draw state composite wire diameter was 0.56 mm, it contained 11,448 x 2.6 micron Nb core, and the twist distance was 1.5 cm. The composite wire cross-section was pure Cu/Ta/11,448 Nb core/Cu/ 91Sn-Cu; containing 22.8 v. % pure Cu, 13.3 v. % Ta; within the Ta layer to prevent Sn diffusion. The wire was sheathed in nonalkaline glass fiber as an insulating layer. A section of wire weighing 160 g was cut off and coiled it into a small solenoid. After reaction diffusion processing at 675 C/30 and curing by vacuum dipping in paraffin, it was measured in a Nb-Ti backfield of 7.2 T intensity, a current of 129 A was passed through the Nb3Sn solenoid and produced a strength of 2.5 T, the overall magnetic field intensity of the composite magnet reached 9.7 T. At this time, the wire full current density J sub c.w. = 5.2 x 10 to the 4th power A/sq cm; the effective current density J sub c (Nb + Sn - Cu) = 8.2 x 10 to the 4th power A/sq cm.

Perforated plates for cryogenic regenerators and method of fabrication

DOEpatents

Hendricks, J.B.

1994-03-29

Perforated plates having very small holes with a uniform diameter throughout the plate thickness are prepared by a [open quotes]wire drawing[close quotes] process in which a billet of sacrificial metal is disposed in an extrusion can of the plate metal, and the can is extruded and restacked repeatedly, converting the billet to a wire of the desired hole diameter. At final size, the rod is then sliced into wafers, and the wires are removed by selective etching. This process is useful for plate metals of interest for high performance regenerator applications, in particular, copper, niobium, molybdenum, erbium, and other rare earth metals. Er[sub 3]Ni, which has uniquely favorable thermophysical properties for such applications, may be incorporated in regions of the plates by providing extrusion cans containing erbium and nickel metals in a stacked array with extrusion cans of the plate metal, which may be copper. The array is heated to convert the erbium and nickel metals to Er[sub 3]Ni. Perforated plates having two sizes of perforations, one of which is small enough for storage of helium, are also disclosed. 10 figures.

Perforated plates for cryogenic regenerators and method of fabrication

DOEpatents

Hendricks, John B.

1994-01-01

Perforated plates (10) having very small holes (14) with a uniform diameter throughout the plate thickness are prepared by a "wire drawing" process in which a billet of sacrificial metal is disposed in an extrusion can of the plate metal, and the can is extruded and restacked repeatedly, converting the billet to a wire of the desired hole diameter. At final size, the rod is then sliced into wafers, and the wires are removed by selective etching. This process is useful for plate metals of interest for high performance regenerator applications, in particular, copper, niobium, molybdenum, erbium, and other rare earth metals. Er.sub.3 Ni, which has uniquely favorable thermophysical properties for such applications, may be incorporated in regions of the plates by providing extrusion cans (20) containing erbium and nickel metals in a stacked array (53) with extrusion cans of the plate metal, which may be copper. The array is heated to convert the erbium and nickel metals to Er.sub.3 Ni. Perforated plates having two sizes of perforations (38, 42), one of which is small enough for storage of helium, are also disclosed.

Embrittlement phenomenon of Ag core MP35N cable as lead conductor in medical device.

PubMed

Wang, Ling; Li, Bernie; Zhang, Haitao

2013-02-01

Ag core MP35N (Ag/MP35N) wire has been used in lead electric conductor wires in the medical device industry for many years. Recently it was noticed that the combination of silver and MP35N restricts its wire drawing process. The annealing temperature in Ag/MP35N has to be lower than the melting temperature of pure Ag (960 °C), which cannot fully anneal MP35N. The lower annealing temperature results in a highly cold worked MP35N, which significantly reduces Ag/MP35N ductility. The embrittlement phenomenon of Ag/MP35N cable was observed in tension and bending deformation. The effect of the embrittlement on the wire flex fatigue life was evaluated using a newly developed flex fatigue testing method. The Ag/MP35N cable fatigue results was analyzed with a Coffin-Manson approach and compared to the MP35N cable fatigue results. The root causes of the Ag/Mp35N embrittlement phenomenon are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Finite Element Modeling of Dieless Tube Drawing of Strain Rate Sensitive Material with Coupled Thermo-Mechanical Analysis

NASA Astrophysics Data System (ADS)

Furushima, Tsuyoshi; Sakai, Takashi; Manabe, Ken-ichi

2004-06-01

Dieless drawing is a unique deformation process without conventional dies, which can achieve a great reduction of wire and tube metals in single pass by means of local heating and cooling approach. In this study, for microtube forming, the dieless drawing process applying superplastic behavior was analyzed by finite element method (FEM) in order to clarify the effect of dieless tube drawing conditions such as tensile speed, moving speed of heating and cooling system, and material properties on deformation behavior of the tube. In the calculation, the material properties were dealt in a special subroutine, whose constitutive equation was defined as σ = Kɛnɛ˙m, and was linked to the solver. A coupled thermo-mechanical analysis was performed for the dieless tube drawing using the FEM. In the thermal analysis of dieless tube drawing, heat transfer was introduced to calculate the heat flux between heating coil and tube surface, and heat conduction in a tube. The influence of dieless tube drawing conditions on deformation behavior was clarified. As a result, for the strain rate sensitive material, the maximum reduction of area and the minimum outer diameter in single pass attain to 90.9% and 2.56mm, respectively. From the result, it is concluded that the dieless tube drawing is essential to produce an extrafine microtube by reason of keeping cylindrical tube diameter ratio constant with extremely high reduction.

Magnetic properties of permalloy wires in vycor capillaries

NASA Astrophysics Data System (ADS)

Lubitz, P.; Ayers, J. D.; Davis, A.

1991-11-01

Thin wires of NiFe alloys with compositions near 80% Ni were prepared by melting the alloy in vycor tubes and drawing fibers from the softened glass. The resulting fibers consist of relatively thick-walled vycor capillaries containing permalloy wires filling a few percent of the volume. The wires are continuous over considerable lengths, uniform in circular cross section, nearly free of contact with the walls and can be drawn to have diameters less than 1 μm. Their magnetic properties are generally similar to bulk permalloy, but show a variety of magnetic switching behaviors for fields along the wire axis, depending on composition, wire diameter, and thermal history. As pulled, the wires can show sharp switching, reversible rotation or mixed behavior. This method can produce NiFe alloy wires suitable for use in applications as sensor, memory or inductive elements; other alloys, such as supermalloy and sendust, also can be fabricated as fine wires by this method.

Alloys For Corrosive, Hydrogen-Rich Environments

NASA Technical Reports Server (NTRS)

Mcpherson, William B.; Bhat, Biliyar N.; Chen, Po-Shou; Kuruvilla, A. K.; Panda, Binayak

1993-01-01

"NASA-23" denotes class of alloys resisting both embrittlement by hydrogen and corrosion. Weldable and castable and formed by such standard processes as rolling, forging, and wire drawing. Heat-treated to obtain desired combinations of strength and ductility in ranges of 100 to 180 kpsi yield strength, 120 to 200 kpsi ultimate tensile strength, and 10 to 30 percent elongation at break. Used in place of most common aerospace structural alloy, Inconel(R) 718.

Method for making an elastomeric member with end pieces

DOEpatents

Hoppie, Lyle O.; McNinch, Jr., Joseph H.; Nowell, Gregory C.

1984-01-01

A molding process for molding an elongated elastomeric member (60) with wire mesh sleeves (16) bonded to the ends (14). A molding preform (10) of elastomeric material is positioned within a seamless mold cylinder (26), and the open ends of the wire mesh sleeves (16) are mounted to end plug assemblies (30) slidably received into the mold cylinder (26) and positioned against the ends (14) of the preform (10). A specialized profile is formed into surfaces (44) of the respective end plug assemblies (30) and by heating of the mold (26), the ends (14) of the elastomeric preform (10) are molded to the profile, as well as bonded to the reinforcing wire mesh sleeves (16). Vacuum is applied to the interior of the mold to draw outgassing vapors through relief spaces therethrough. The completed elastomeric member (60) is removed from the mold cylinder (26) by stretching, the consequent reduction in diameter enabling ready separation from the mold cylinder (26) and removal thereof.

Research on High Temperature Ceramic Insulation for Electrical Conductors

NASA Technical Reports Server (NTRS)

Kreidler, Eric R.; Bhallamudi, Vidya Praveen

2001-01-01

Three methods for applying ceramic coatings to wires were examined in depth and a fourth (chemical vapor deposition) was studied briefly. CVD coatings were not reported in the thesis because it was realized early in the study that the deposition rate of the coatings was too slow to be used in a commercial process. Of the methods reported in the thesis, slurry coating was the most promising. This method consists of slowly drawing a platinum wire through a thixotropic slurry of alumina in a vehicle composed of polyvinyl butyral, methyl ethyl ketone, and toluene. The coatings produced by this method were continuous and free of cracks after sintering. The sintered coatings crack when the wire is bent around sharp corners, but most of the coating remains in place and still provides electrical insulation between the wire and any metallic structure to which the wire may be attached. The coating thickness was 0.61 mm (16 micrometers). The electrical resistivity of the intact coating was 340 M-Ohm-cm at 800 C and 23 M-Ohm-cm at 1050 C. Therefore, these coatings more than meet the electrical requirements for use in turbine engines. Although adherence of the coating to the wire was generally excellent, a problem was noted in localized areas where the coating flaked off. Further work will be needed to obtain good coating adherence along the entire length of the wire. The next most promising coatings were made by electrophoretic deposition (EPD) of Al2O3 onto platinum wires, using mixtures of ethanol and acetone as the suspending liquid. These EPD coatings were made only on short lengths of wire because the coating is too fragile to allow spooling of the wire. The worst coatings were those made by electrophoretic deposition from aqueous suspensions. Continuous slurry coating of wire was achieved, but due to lack of suitable equipment, the wire had to be cut into short lengths for sintering.

Mechanical Device Traces Parabolas

NASA Technical Reports Server (NTRS)

Soper, Terry A.

1989-01-01

Mechanical device simplifies generation of parabolas of various focal lengths. Based on fundamental geometrical construction of parabola. Constancy of critical total distance enforced by maintaining cable in tension. Applications of device include design of paraboloidal antennas, approximating catenaries on drawings of powerlines or long-wire antennas, and general tracing of parabolas on drawings.

Controlled rolling process for dual phase steels and application to rod, wire, sheet and other shapes

DOEpatents

Thomas, G.; Ahn, J.H.; Kim, N.J.

1986-10-28

An improved, energy efficient, hot rolling method for direct production of cold formable dual-phase steel is provided. The steel is heated to completely austenitize it and then continuously hot rolled and cooled down into the ferrite-austenite two phase region to a temperature which is just below the effective Ar[sub 3] temperature. The hot rolled steel is then rapidly quenched to provide an alloy containing strong, tough lath martensite (fibers) in a ductile soft ferrite matrix. The method is particularly useful for providing rods in which form the alloy is capable of being drawn into high strength wire or the like in a cold drawing operation without any intermediate annealing or patenting, and has excellent strength, ductility and fatigue characteristics. 3 figs.

Controlled rolling process for dual phase steels and application to rod, wire, sheet and other shapes

DOEpatents

Thomas, Gareth; Ahn, Jae-Hwan; Kim, Nack-Joon

1986-01-01

An improved, energy efficient, hot rolling method for direct production of cold formable dual-phase steel is provided. The steel is heated to completely austenitize it and then continuously hot rolled and cooled down into the ferrite-austenite two phase region to a temperature which is just below the effective Ar.sub.3 temperature. The hot rolled steel is then rapidly quenched to provide an alloy containing strong, tough lath martensite (fibers) in a ductile soft ferrite matrix. The method is particularly useful for providing rods in which form the alloy is capable of being drawn into high strength wire or the like in a cold drawing operation without any intermediate annealing or patenting, and has excellent strength, ductility and fatigue characteristics.

Sulfur Content Precision Control Technology for CO2-Shielded Welding Wire Steel

NASA Astrophysics Data System (ADS)

Chaofa, Zhang; Huaqiang, Hao; Youbing, Xiang; Shanxi, Liu

As a kind of impurity and displaying with FeS and MnS form in steel, Sulfur can make the disadvantage effect on the performance of hot-working, welding and corrosion resistance. The high content sulfur in steel can cause the hot brittle phenomenon for the steel. For the welding steel, when the sulfur content is higher, the drawing performance of wire rod become worst and the yield of wire rod decrease. When the sulfur is lower, the automatic wire feeding performance for the gas shielded welding become worst and the weld seam is not smooth. According to the results of welding expert research, 0.010%≤ S≤ 0.020% in CO2-shielded welding wire steel is reasonable.

Prosthetic leg powered by MR brake and SMA wires

NASA Astrophysics Data System (ADS)

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.

51. Photograph of an original construction drawing, dated August 1927, ...

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

51. Photograph of an original construction drawing, dated August 1927, in the possession of Facilities planning Office, Iowa State University, Ames, Iowa. GROUND FLOOR PLAN, MECHANICAL FAN ROOM LAYOUT, ELECTRICAL WIRING DIAGRAM, RADIATOR, FANS 1 & 2, DETAILS; SHEET NO. 202 OF 3 - Dairy Industry Building, Iowa State University campus, Ames, Story County, IA

The Tail of BPM

NASA Astrophysics Data System (ADS)

Kruba, Steve; Meyer, Jim

Business process management suites (BPMS's) represent one of the fastest growing segments in the software industry as organizations automate their key business processes. As this market matures, it is interesting to compare it to Chris Anderson's 'Long Tail.' Although the 2004 "Long Tail" article in Wired magazine was primarily about the media and entertainment industries, it has since been applied (and perhaps misapplied) to other markets. Analysts describe a "Tail of BPM" market that is, perhaps, several times larger than the traditional BPMS product market. This paper will draw comparisons between the concepts in Anderson's article (and subsequent book) and the BPM solutions market.

Interactive wire-frame ship hullform generation and display

NASA Technical Reports Server (NTRS)

Calkins, D. E.; Garbini, J. L.; Ishimaru, J.

1984-01-01

An interactive automated procedure to generate a wire frame graphic image of a ship hullform, which uses a digitizing tablet in conjunction with the hullform lines drawing, was developed. The geometric image created is displayed on an Evans & Sutherland PS-300 graphics terminal for real time interactive viewing or is output as hard copy on an inexpensive dot matrix printer.

Fabrication of fine-grain tantalum diffusion barrier tube for Nb3Sn conductors

NASA Astrophysics Data System (ADS)

Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N.; Robinson, J.; Barber, R. E.

2014-01-01

Diffusion barriers used in Nb3Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy.

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

Yu, Cun; Aoun, Bachir; Cui, Lishan

Microstructure evolution of a cold-drawn NiTi shape memory alloy wire was investigated by means of in-situ synchrotron high-energy X-ray diffraction during continuous heating. The cold-drawn wire contained amorphous regions and nano-crystalline domains in its microstructure. Pair distribution function analysis revealed that the amorphous regions underwent structural relaxation via atomic rearrangement when heated above 100 °C. The nano-crystalline domains were found to exhibit a strong cold work induced lattice strain anisotropy having a preferential <111> fiber orientation along the wire axial direction. The lattice strain anisotropy systematically decreased upon heating above 200 °C, implying a structural recovery. A broad conical texturemore » was formed in the wire specimen after crystallization similar in detail to the initial <111> texture axial orientation of the nano-crystalline domains produced by the severe cold wire drawing deformation.« less

Deformability of Oxide Inclusions in Tire Cord Steels

NASA Astrophysics Data System (ADS)

Zhang, Lifeng; Guo, Changbo; Yang, Wen; Ren, Ying; Ling, Haitao

2018-04-01

The deformation of oxide inclusions in tire cord steels during hot rolling was analyzed, and the factors influencing their deformability at high and low temperatures were evaluated and discussed. The aspect ratio of oxide inclusions decreased with the increasing reduction ratio of the steel during hot rolling owing to the fracture of the inclusions. The aspect ratio obtained after the first hot-rolling process was used to characterize the high-temperature deformability of the inclusions. The deformation first increased and then decreased with the increasing (MgO + Al2O3)/(SiO2 + MnO) ratio of the inclusions. It also increased with the decreasing melting temperatures of the inclusions. Young's modulus was used to evaluate the low-temperature deformability of the inclusions. An empirical formula was fitted to calculate the Young's moduli of the oxides using the mean atomic volume. The moduli values of the inclusions causing wire fracture were significantly greater than the average. To reduce fracture in tire cord steel wires during cold drawing, it is proposed that inclusions be controlled to those with high SiO2 content and extremely low Al2O3 content. This proposal is based on the hypothesis that the deformabilities of oxides during cold drawing are inversely proportional to their Young's moduli. The future study thus proposed includes an experimental confirmation for the abovementioned predictions.

Relationship between friction force and orthodontic force at the leveling stage using a coated wire.

PubMed

Murayama, Masaki; Namura, Yasuhiro; Tamura, Takahiko; Iwai, Hiroaki; Shimizu, Noriyoshi

2013-01-01

The relationship between orthodontic force and friction produced from an archwire and brackets affects the sliding of the wire in the leveling stage. The purpose of this study was to evaluate the relationship between force and friction in a small esthetic nickel-titanium (Ni-Ti) wire. Five esthetic wires (three coated and two plated) and two small, plain Ni-Ti wires (0.012 and 0.014 inches) were used. We performed a three-point bending test according to ISO 15841 and the drawing test with a dental arch model designed with upper linguoversion of the lateral incisor in the arch (displacements of 0.5, 1.0, 2.0 and 3.0 mm), and evaluated the relationship between them. Unloading bending forces of all wires at displacements of less than 1.0 mm were larger than friction forces, but all friction forces at displacements exceeding 2.0 mm were larger than unloading bending forces. The arch likely expands when displacement from the proximal brackets exceeds 1.0 mm. The friction force of a martensite 0.014-inch Ni-Ti wire was significantly greater than those of the other esthetic and austenitic wires. A wire with the smallest possible friction force should be used in cases with more than 1.0 mm displacement.

Measurement and modeling of dispersive pulse propagation in draw wire waveguides

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Kohl, Thomas W.; Rogers, Wayne P.

1995-01-01

An analytical model of dispersive pulse propagation in semi-infinite cylinders due to transient axially symmetric end conditions has been experimentally investigated. Specifically, the dispersive propagation of the first axially symmetric longitudinal mode in thin wire waveguides, which have ends in butt contact with longitudinal piezoelectric ultrasonic transducers, is examined. The method allows for prediction of a propagated waveform given a measured source waveform, together with the material properties of the cylinder. Alternatively, the source waveform can be extracted from measurement of the propagated waveform. The material properties required for implementation of the pulse propagation model are determined using guided wave phase velocity measurements. Hard tempered aluminum 1100 and 304 stainless steel wires, with 127, 305, and 406 micron diam., were examined. In general, the drawn wires were found to behave as transversely isotropic media.

Electrodynamic Tether

NASA Technical Reports Server (NTRS)

Johnson, Charles L. (Inventor); Ballance, Judy L. (Inventor); Welzyn, Kenneth J. (Inventor); Vaughn, Jason A. (Inventor); Lorenzini, Enrico (Inventor); Schuler, Peter S. (Inventor)

2006-01-01

A tether system for providing thrust to or power subsystems of an artificial satellite in a low earth orbit. The tether has three main sections, an insulated section connected to the satellite, a conducting section connected to the insulating section for drawing in and releasing electrons from the space plasma and a non-conducting section for providing a tension to the other sections of the tether. An oxygen resistant coating is applied to the bare wire of the conducting section as well as the insulated wires of the insulated section that prevents breakdown during tether operations in the space plasma. The insulated and bare wire sections also surround a high tensile flexible polymer core to prevent any debris from breaking the tether during use.

A deformation-processed Al-matrix/Ca-nanofilamentary composite with low density, high strength, and high conductivity

DOE PAGES

Tian, Liang

2017-03-06

Light, strong materials with high conductivity are desired for many applications such as power transmission conductors, fly-by-wire systems, and downhole power feeds. However, it is difficult to obtain both high strength and high conductivity simultaneously in a material. In this study, an Al/Ca (20 vol%) nanofilamentary metal-metal composite was produced by powder metallurgy and severe plastic deformation. Fine Ca metal powders (~200 µm) were produced by centrifugal atomization, mixed with pure Al powder, and deformed by warm extrusion, swaging, and wire drawing to a true strain of 12.9. The Ca powder particles became fine Ca nanofilaments that reinforce the compositemore » substantially by interface strengthening. The conductivity of the composite is slightly lower than the rule-of-mixtures prediction due to minor quantities of impurity inclusions. As a result, the elevated temperature performance of this composite was also evaluated by differential scanning calorimetry and resistivity measurements.« less

A deformation-processed Al-matrix/Ca-nanofilamentary composite with low density, high strength, and high conductivity

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

Tian, Liang

Light, strong materials with high conductivity are desired for many applications such as power transmission conductors, fly-by-wire systems, and downhole power feeds. However, it is difficult to obtain both high strength and high conductivity simultaneously in a material. In this study, an Al/Ca (20 vol%) nanofilamentary metal-metal composite was produced by powder metallurgy and severe plastic deformation. Fine Ca metal powders (~200 µm) were produced by centrifugal atomization, mixed with pure Al powder, and deformed by warm extrusion, swaging, and wire drawing to a true strain of 12.9. The Ca powder particles became fine Ca nanofilaments that reinforce the compositemore » substantially by interface strengthening. The conductivity of the composite is slightly lower than the rule-of-mixtures prediction due to minor quantities of impurity inclusions. As a result, the elevated temperature performance of this composite was also evaluated by differential scanning calorimetry and resistivity measurements.« less

Relationship between friction force and orthodontic force at the leveling stage using a coated wire

PubMed Central

MURAYAMA, Masaki; NAMURA, Yasuhiro; TAMURA, Takahiko; IWAI, Hiroaki; SHIMIZU, Noriyoshi

2013-01-01

The relationship between orthodontic force and friction produced from an archwire and brackets affects the sliding of the wire in the leveling stage. Objective The purpose of this study was to evaluate the relationship between force and friction in a small esthetic nickel-titanium (Ni-Ti) wire. Material and Methods Five esthetic wires (three coated and two plated) and two small, plain Ni-Ti wires (0.012 and 0.014 inches) were used. We performed a three-point bending test according to ISO 15841 and the drawing test with a dental arch model designed with upper linguoversion of the lateral incisor in the arch (displacements of 0.5, 1.0, 2.0 and 3.0 mm), and evaluated the relationship between them. Results Unloading bending forces of all wires at displacements of less than 1.0 mm were larger than friction forces, but all friction forces at displacements exceeding 2.0 mm were larger than unloading bending forces. The arch likely expands when displacement from the proximal brackets exceeds 1.0 mm. The friction force of a martensite 0.014-inch Ni-Ti wire was significantly greater than those of the other esthetic and austenitic wires. Conclusions A wire with the smallest possible friction force should be used in cases with more than 1.0 mm displacement. PMID:24473722

Drafting. Advanced Print Reading--Electrical.

ERIC Educational Resources Information Center

Oregon State Dept. of Education, Salem.

This document is a workbook for drafting students learning advanced print reading for electricity applications. The workbook contains seven units covering the following material: architectural working drawings; architectural symbols and dimensions; basic architectural electrical symbols; wiring symbols; riser diagrams; schematic diagrams; and…

Influence of Nitinol wire surface treatment on oxide thickness and composition and its subsequent effect on corrosion resistance and nickel ion release.

PubMed

Clarke, B; Carroll, W; Rochev, Y; Hynes, M; Bradley, D; Plumley, D

2006-10-01

Medical implants and devices are now used successfully in surgical procedures on a daily basis. Alloys of nickel and titanium, and in particular Nitinol are of special interest in the medical device industry, because of their shape memory and superelastic properties. The corrosion behavior of nitinol in the body is also of critical importance because of the known toxicological effects of nickel. The stability of a NiTi alloy in the physiological environment is dependant primarily on the properties of the mostly TiO(2) oxide layer that is present on the surface. For the present study, a range of nitinol wires have been prepared using different drawing processes and a range of surface preparation procedures. It is clear from the results obtained that the wire samples with very thick oxides also contain a high nickel content in the oxide layer. The untreated samples with the thicker oxides show the lowest pitting potential values and greater nickel release in both long and short-term experiments. It was also found that after long-term immersion tests breakdown potentials increased for samples that exhibited lower values initially. From these results it would appear that surface treatment is essential for the optimum bioperformance of nitinol. (c) 2006 Wiley Periodicals, Inc

Californium--palladium metal neutron source material

DOEpatents

Dahlen, B.L.; Mosly, W.C. Jr.; Smith, P.K.; Albenesius, E.L.

1974-01-22

Californium, as metal or oxide, is uniformly dispersed throughout a noble metal matrix, provided in compact, rod or wire form. A solution of californium values is added to palladium metal powder, dried, blended and pressed into a compact having a uni-form distribution of californium. The californium values are decomposed to californium oxide or metal by heating in an inert or reducing atmosphere. Sintering the compact to a high density closes the matrix around the dispersed californium. The sintered compact is then mechanically shaped into an elongated rod or wire form. (4 claims, no drawings) (Official Gazette)

Electrochemical investigations of Cr-Ni-Mo stainless steel used in urology

NASA Astrophysics Data System (ADS)

Przondziono, J.; Walke, W.

2011-05-01

The influence of chemical passivation process on physical and chemical characteristics of samples made of X2CrNiMo 17-7-2 steel with differentiated hardening, in the solution simulating the environment of human urine was analysed in the study. Wire obtained in cold drawing process is used for the production of stents and appliances in urological treatment. Proper roughness of the surface was obtained through mechanical working - grinding (Ra = 0,40 μn) and electrochemical polishing (Ra = 0,12 μn). Chemical passivation process was carried out in 40% solution of HN03 within 60 minutes in the temperature of 65°C. The tests of corrosion resistance were made on the ground of registered anodic polarisation curves and Stern method. For evaluation of phenomena occurring on the surface of tested steel, electrochemical impedance spectroscopy (EIS) was applied.

30 CFR 27.4 - Application procedures and requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... applicable MSHA product approval requirements; (iii) Identification of components or features of the product that are critical to the safety of the product; and (iv) All documentation, including drawings and... all components and subassemblies that are submitted for investigation, and shall include wiring and...

30 CFR 27.4 - Application procedures and requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... applicable MSHA product approval requirements; (iii) Identification of components or features of the product that are critical to the safety of the product; and (iv) All documentation, including drawings and... all components and subassemblies that are submitted for investigation, and shall include wiring and...

A debugging method of the Quadrotor UAV based on infrared thermal imaging

NASA Astrophysics Data System (ADS)

Cui, Guangjie; Hao, Qian; Yang, Jianguo; Chen, Lizhi; Hu, Hongkang; Zhang, Lijun

2018-01-01

High-performance UAV has been popular and in great need in recent years. The paper introduces a new method in debugging Quadrotor UAVs. Based on the infrared thermal technology and heat transfer theory, a UAV is under debugging above a hot-wire grid which is composed of 14 heated nichrome wires. And the air flow propelled by the rotating rotors has an influence on the temperature distribution of the hot-wire grid. An infrared thermal imager below observes the distribution and gets thermal images of the hot-wire grid. With the assistance of mathematic model and some experiments, the paper discusses the relationship between thermal images and the speed of rotors. By means of getting debugged UAVs into test, the standard information and thermal images can be acquired. The paper demonstrates that comparing to the standard thermal images, a UAV being debugging in the same test can draw some critical data directly or after interpolation. The results are shown in the paper and the advantages are discussed.

Superelasticity of NiTi Ring-Shaped Springs Induced by Aging for Cranioplasty Applications

NASA Astrophysics Data System (ADS)

Morawiec, Henryk Z.; Lekston, Zdzisław H.; Kobus, Kazimierz F.; Węgrzyn, Marek C.; Drugacz, Jan T.

2009-08-01

This paper concerns the application of titanium-nickel rings in modeling the cranium. After being fixed to the osseous margins, the ring’s expansion at the same time broadens and shortens the cranium vault. The rings formed from a straight superelastic wire, flattened to an ellipse, do not show the presence of a typical force plateau but rather a pseudoelastic loop during loading-unloading in the relationship between the force and the deflection. Based on the idea that superelasticity in more complex shape-springs may be induced by the precipitation hardening process, the further studies were carried out on alloys with higher nickel contents (51.06 at.% Ni). The rings that had been formed were welded and aged at an optimal temperature and time. The improved superelastic behavior during compression and unloading the rings was obtained by introducing small deformation by drawing the quenched wires before forming the rings and aging. Very positive clinical reshaping by long-term distraction with the superelastic ring-shaped springs was achieved in young children under one year and a less spectacular effect was observed in the group of older children.

Desktop computer graphics for RMS/payload handling flight design

NASA Technical Reports Server (NTRS)

Homan, D. J.

1984-01-01

A computer program, the Multi-Adaptive Drawings, Renderings and Similitudes (MADRAS) program, is discussed. The modeling program, written for a desktop computer system (the Hewlett-Packard 9845/C), is written in BASIC and uses modular construction of objects while generating both wire-frame and hidden-line drawings from any viewpoint. The dimensions and placement of objects are user definable. Once the hidden-line calculations are made for a particular viewpoint, the viewpoint may be rotated in pan, tilt, and roll without further hidden-line calculations. The use and results of this program are discussed.

Cold-Drawn Bioabsorbable Ferrous and Ferrous Composite Wires: An Evaluation of Mechanical Strength and Fatigue Durability

NASA Astrophysics Data System (ADS)

Schaffer, Jeremy E.; Nauman, Eric A.; Stanciu, Lia A.

2012-08-01

Yield strengths exceeding 1 GPa with elastic strains exceeding 1 pct were measured in novel bioabsorbable wire materials comprising high-purity iron (Fe), manganese (Mn), magnesium (Mn), and zinc (Zn), which may enable the development of self-expandable, bioabsorbable, wire-based endovascular stents. The high strength of these materials is attributed to the fine microstructure and fiber textures achieved through cold drawing techniques. Bioabsorbable vascular stents comprising nutrient metal compositions may provide a means to overcome the limitations of polymer-based bioabsorbable stents such as excessive strut thickness and poor degradation rate control. Thin, 125- μm wires comprising combinations of ferrous alloys surrounding a relatively anodic nonferrous core were manufactured and tested using monotonic and cyclic techniques. The strength and durability properties are tested in air and in body temperature phosphate-buffered saline, and then they were compared with cold-drawn 316L stainless steel wire. The antiferromagnetic Fe35Mn-Mg composite wire exhibited more than 7 pct greater elasticity (1.12 pct vs 1.04 pct engineering strain), similar fatigue strength in air, an ultimate strength of more than 1.4 GPa, and a toughness exceeding 35 mJ/mm3 compared with 30 mJ/mm3 for 316L.

Metallurgical characterization of a new nickel-titanium wire for rotary endodontic instruments.

PubMed

Alapati, Satish B; Brantley, William A; Iijima, Masahiro; Clark, William A T; Kovarik, Libor; Buie, Caesar; Liu, Jie; Ben Johnson, William

2009-11-01

A novel thermomechanical processing procedure has been developed that yields a superelastic (SE) nickel-titanium (NiTi) wire (M-Wire) that laboratory testing shows has improved mechanical properties compared with conventional SE austenitic NiTi wires used for manufacture of rotary instruments. The objective of this study was to determine the origin of the improved mechanical properties. Specimens from 2 batches of M-Wire prepared under different processing conditions and from 1 batch of standard-processed SE wire for rotary instruments were examined by scanning transmission electron microscopy, temperature-modulated differential scanning calorimetry, micro-x-ray diffraction, and scanning electron microscopy with x-ray energy-dispersive spectrometric analyses. The processing for M-Wire yields a microstructure containing martensite, that the proportions of NiTi phases depend on processing conditions, and that the microstructure exhibits pronounced evidence of alloy strengthening. The presence of Ti(2)Ni precipitates in both microstructures indicates that M-Wire and the conventional SE wire for rotary instruments are titanium-rich.

46 CFR 162.017-6 - Procedure for approval.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and size of wire of flame screens. (c) Pre-approval tests. Before approval is granted, the... desiring approval of a new design or type of pressure-vacuum relief valve shall submit drawings in quadruplicate showing the design of the valve, the sizes for which approval is requested, method of operation...

46 CFR 162.017-6 - Procedure for approval.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and size of wire of flame screens. (c) Pre-approval tests. Before approval is granted, the... desiring approval of a new design or type of pressure-vacuum relief valve shall submit drawings in quadruplicate showing the design of the valve, the sizes for which approval is requested, method of operation...

46 CFR 162.017-6 - Procedure for approval.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and size of wire of flame screens. (c) Pre-approval tests. Before approval is granted, the... desiring approval of a new design or type of pressure-vacuum relief valve shall submit drawings in quadruplicate showing the design of the valve, the sizes for which approval is requested, method of operation...

Modeling and simulation of the fluid flow in wire electrochemical machining with rotating tool (wire ECM)

NASA Astrophysics Data System (ADS)

Klocke, F.; Herrig, T.; Zeis, M.; Klink, A.

2017-10-01

Combining the working principle of electrochemical machining (ECM) with a universal rotating tool, like a wire, could manage lots of challenges of the classical ECM sinking process. Such a wire-ECM process could be able to machine flexible and efficient 2.5-dimensional geometries like fir tree slots in turbine discs. Nowadays, established manufacturing technologies for slotting turbine discs are broaching and wire electrical discharge machining (wire EDM). Nevertheless, high requirements on surface integrity of turbine parts need cost intensive process development and - in case of wire-EDM - trim cuts to reduce the heat affected rim zone. Due to the process specific advantages, ECM is an attractive alternative manufacturing technology and is getting more and more relevant for sinking applications within the last few years. But ECM is also opposed with high costs for process development and complex electrolyte flow devices. In the past, few studies dealt with the development of a wire ECM process to meet these challenges. However, previous concepts of wire ECM were only suitable for micro machining applications. Due to insufficient flushing concepts the application of the process for machining macro geometries failed. Therefore, this paper presents the modeling and simulation of a new flushing approach for process assessment. The suitability of a rotating structured wire electrode in combination with an axial flushing for electrodes with high aspect ratios is investigated and discussed.

Investigation of ball bond integrity for 0.8 mil (20 microns) diameter gold bonding wire on low k die in wire bonding technology

NASA Astrophysics Data System (ADS)

Kudtarkar, Santosh Anil

Microelectronics technology has been undergoing continuous scaling to accommodate customer driven demand for smaller, faster and cheaper products. This demand has been satisfied by using novel materials, design techniques and processes. This results in challenges for the chip connection technology and also the package technology. The focus of this research endeavor was restricted to wire bond interconnect technology using gold bonding wires. Wire bond technology is often regarded as a simple first level interconnection technique. In reality, however, this is a complex process that requires a thorough understanding of the interactions between the design, material and process variables, and their impact on the reliability of the bond formed during this process. This research endeavor primarily focused on low diameter, 0.8 mil thick (20 mum) diameter gold bonding wire. Within the scope of this research, the integrity of the ball bond formed by 1.0 mil (25 mum) and 0.8 mil (20 mum) diameter wires was compared. This was followed by the evaluation of bonds formed on bond pads having doped SiO2 (low k) as underlying structures. In addition, the effect of varying the percentage of the wire dopant, palladium and bonding process parameters (bonding force, bond time, ultrasonic energy) for 0.8 mil (20 mum) bonding wire was also evaluated. Finally, a degradation empirical model was developed to understand the decrease in the wire strength. This research effort helped to develop a fundamental understanding of the various factors affecting the reliability of a ball bond from a design (low diameter bonding wire), material (low k and bonding wire dopants), and process (wire bonding process parameters) perspective for a first level interconnection technique, namely wire bonding. The significance of this research endeavor was the systematic investigation of the ball bonds formed using 0.8 mil (20 microm) gold bonding wire within the wire bonding arena. This research addressed low k structures on 90 nm silicon technology, bonding wires with different percentage of doping element (palladium), and different levels of bonding process parameters. An empirical model to understand the high temperature effects for bonds formed using the low diameter wire was also developed.

Forming Refractory Insulation On Copper Wire

NASA Technical Reports Server (NTRS)

Setlock, J.; Roberts, G.

1995-01-01

Alternative insulating process forms flexible coat of uncured refractory insulating material on copper wire. Coated wire formed into coil or other complex shape. Wire-coating apparatus forms "green" coat on copper wire. After wire coiled, heating converts "green" coat to refractory electrical insulator. When cured to final brittle form, insulating material withstands temperatures above melting temperature of wire. Process used to make coils for motors, solenoids, and other electrical devices to be operated at high temperatures.

Process for attaching molecular wires and devices to carbon nanotubes and compositions thereof

NASA Technical Reports Server (NTRS)

Yang, Jiping (Inventor); Tour, James M. (Inventor); Bahr, Jeffrey L. (Inventor)

2008-01-01

The present invention is directed towards processes for covalently attaching molecular wires and molecular electronic devices to carbon nanotubes and compositions thereof. Such processes utilize diazonium chemistry to bring about this marriage of wire-like nanotubes with molecular wires and molecular electronic devices.

Is Big Brother Watching the Wired Campus? Information Technologies Undermine the Climate of Freedom in Academia.

ERIC Educational Resources Information Center

Earls, Alan R.

2000-01-01

Explores privacy issues raised by information technology at colleges and universities. Drawing on accounts and opinions of faculty and staff members, provides examples of current practices and policies on Internet and e-mail use and discusses the possible need for more developed policies. (EV)

Promoting Sustainability in a College Café by Opposite-Sex Cashiers

ERIC Educational Resources Information Center

Tifferet, Sigal; Rosenblit, Niv; Shalev, Maya

2017-01-01

Purpose: People engage in green consumption for many reasons, both conscious and unconscious. This paper aims to draw on evolutionary psychology to propose that hard-wired mating strategies encourage both men and women to increase their green consumption in the presence of members of the opposite sex. Design/methodology/approach: Observations were…

Weld Wire Investigation Summary

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

Cunningham, M.A.

1999-03-22

After GTA welding reservoir A production/process prove-in assemblies, X-ray examination detected a lack of sidewall fusion. After examining several possible causes, it was determined that the weld wire filler metal was responsible, particularly the wire cleaning process. The final conclusion was that the filler wire must be abrasively cleaned in a particular manner to perform as required. The abrasive process was incorporated into the wire material specification, ensuring consistency for all reservoir GTA welding at AlliedSignal Federal Manufacturing and Technologies (FM and T).

MATERIALS WITH COMPLEX ELECTRONIC/ATOMIC STRUCTURES

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

D. M. PARKIN; L. CHEN; ET AL

2000-09-01

We explored both experimentally and theoretically the behavior of materials at stresses close to their theoretical strength. This involves the preparation of ultra fine scale structures by a variety of fabrication methods. In the past year work has concentrated on wire drawing of in situ composites such as Cu-Ag and Cu-Nb. Materials were also fabricated by melting alloys in glass and drawing them into filaments at high temperatures by a method known as Taylor wire technique. Cu-Ag microwires have been drawn by this technique to produce wires 10 {micro}m in diameter that consist of nanoscale grains of supersaturated solid solution.more » Organogels formed from novel organic gelators containing cholesterol tethered to squaraine dyes or trans-stilbene derivatives have been studied from several different perspectives. The two types of molecules are active toward several organic liquids, gelling in some cases at w/w percentages as low as 0.1. While relatively robust, acroscopically dry gels are formed in several cases, studies with a variety of probes indicate that much of the solvent may exist in domains that are essentially liquid-like in terms of their microenvironment. The gels have been imaged by atomic force microscopy and conventional and fluorescence microscopy, monitoring both the gelator fluorescence in the case of the stilbene-cholesterol gels and, the fluorescence of solutes dissolved in the solvent. Remarkably, our findings show that several of the gels are composed of similarly appearing fibrous structures visible at the nano-, micro-, and macroscale.« less

Advantages of a distant cellulase catalytic base.

PubMed

Burgin, Tucker; Ståhlberg, Jerry; Mayes, Heather B

2018-03-30

The inverting glycoside hydrolase Trichoderma reesei ( Hypocrea jecorina ) Cel6A is a promising candidate for protein engineering for more economical production of biofuels. Until recently, its catalytic mechanism had been uncertain: The best candidate residue to serve as a catalytic base, Asp-175, is farther from the glycosidic cleavage site than in other glycoside hydrolase enzymes. Recent unbiased transition path sampling simulations revealed the hydrolytic mechanism for this more distant base, employing a water wire; however, it is not clear why the enzyme employs a more distant catalytic base, a highly conserved feature among homologs across different kingdoms. In this work, we describe molecular dynamics simulations designed to uncover how a base with a longer side chain, as in a D175E mutant, affects procession and active site alignment in the Michaelis complex. We show that the hydrogen bond network is tuned to the shorter aspartate side chain, and that a longer glutamate side chain inhibits procession as well as being less likely to adopt a catalytically productive conformation. Furthermore, we draw comparisons between the active site in Trichoderma reesei Cel6A and another inverting, processive cellulase to deduce the contribution of the water wire to the overall enzyme function, revealing that the more distant catalytic base enhances product release. Our results can inform efforts in the study and design of enzymes by demonstrating how counterintuitive sacrifices in chemical reactivity can have worthwhile benefits for other steps in the catalytic cycle. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Use of beam deflection to control an electron beam wire deposition process

NASA Technical Reports Server (NTRS)

Taminger, Karen M. (Inventor); Hofmeister, William H. (Inventor); Hafley, Robert A. (Inventor)

2013-01-01

A method for controlling an electron beam process wherein a wire is melted and deposited on a substrate as a molten pool comprises generating the electron beam with a complex raster pattern, and directing the beam onto an outer surface of the wire to thereby control a location of the wire with respect to the molten pool. Directing the beam selectively heats the outer surface of the wire and maintains the position of the wire with respect to the molten pool. An apparatus for controlling an electron beam process includes a beam gun adapted for generating the electron beam, and a controller adapted for providing the electron beam with a complex raster pattern and for directing the electron beam onto an outer surface of the wire to control a location of the wire with respect to the molten pool.

Using wire shaping techniques and holographic optics to optimize deposition characteristics in wire-based laser cladding.

PubMed

Goffin, N J; Higginson, R L; Tyrer, J R

2016-12-01

In laser cladding, the potential benefits of wire feeding are considerable. Typical problems with the use of powder, such as gas entrapment, sub-100% material density and low deposition rate are all avoided with the use of wire. However, the use of a powder-based source material is the industry standard, with wire-based deposition generally regarded as an academic curiosity. This is because, although wire-based methods have been shown to be capable of superior quality results, the wire-based process is more difficult to control. In this work, the potential for wire shaping techniques, combined with existing holographic optical element knowledge, is investigated in order to further improve the processing characteristics. Experiments with pre-placed wire showed the ability of shaped wire to provide uniformity of wire melting compared with standard round wire, giving reduced power density requirements and superior control of clad track dilution. When feeding with flat wire, the resulting clad tracks showed a greater level of quality consistency and became less sensitive to alterations in processing conditions. In addition, a 22% increase in deposition rate was achieved. Stacking of multiple layers demonstrated the ability to create fully dense, three-dimensional structures, with directional metallurgical grain growth and uniform chemical structure.

Using wire shaping techniques and holographic optics to optimize deposition characteristics in wire-based laser cladding

PubMed Central

Higginson, R. L.; Tyrer, J. R.

2016-01-01

In laser cladding, the potential benefits of wire feeding are considerable. Typical problems with the use of powder, such as gas entrapment, sub-100% material density and low deposition rate are all avoided with the use of wire. However, the use of a powder-based source material is the industry standard, with wire-based deposition generally regarded as an academic curiosity. This is because, although wire-based methods have been shown to be capable of superior quality results, the wire-based process is more difficult to control. In this work, the potential for wire shaping techniques, combined with existing holographic optical element knowledge, is investigated in order to further improve the processing characteristics. Experiments with pre-placed wire showed the ability of shaped wire to provide uniformity of wire melting compared with standard round wire, giving reduced power density requirements and superior control of clad track dilution. When feeding with flat wire, the resulting clad tracks showed a greater level of quality consistency and became less sensitive to alterations in processing conditions. In addition, a 22% increase in deposition rate was achieved. Stacking of multiple layers demonstrated the ability to create fully dense, three-dimensional structures, with directional metallurgical grain growth and uniform chemical structure. PMID:28119550

Welding wire selection critical to jet engine repair work

NASA Astrophysics Data System (ADS)

1992-11-01

A review is provided of issues related to the selection of welding wire for aircraft gas-turbine engines emphasizing the importance of cleanliness in the welding wire product. A three-step metallurgical control process is described for the production of welding wire that is clean and suitable for turbine repair. The process is based on: (1) vacuum induction melting; (2) contamination-free processing of the wire; and (3) environmentally controlled packaging. Weld work on aerospace casting is shown to be useful and suitable for many alloy and superalloy materials with various filler materials.

Wire Composition: Its Effect on Metal Disintegration and Particle Formation in Twin-Wire Arc-Spraying Process

NASA Astrophysics Data System (ADS)

Tillmann, W.; Abdulgader, M.

2013-03-01

The wire tips in twin-wire arc-spraying (TWAS) are heated in three different zones. A high-speed camera was used to observe the melting behavior, metal breakup, and particle formation under different operating conditions. In zone (I), the wire tips are melted (liquidus metal) and directly atomized in the form of smaller droplets. Their size is a function of the specific properties of the molten metal and the exerting aerodynamic forces. Zone (II) is directly beneath zone (I) and the origin of the extruded metal sheets at the wire tips. The extruded metal sheets in the case of cored wires are shorter than those observed while using solid wires. In this study, the effects of adjustable parameters and powder filling on melting behavior, particle formation, and process instability were revealed, and a comparison between solid and cored wires was made. The findings can improve the accuracy of the TWAS process modeling.

Effect of gold wire bonding process on angular correlated color temperature uniformity of white light-emitting diode.

PubMed

Wu, Bulong; Luo, Xiaobing; Zheng, Huai; Liu, Sheng

2011-11-21

Gold wire bonding is an important packaging process of lighting emitting diode (LED). In this work, we studied the effect of gold wire bonding on the angular uniformity of correlated color temperature (CCT) in white LEDs whose phosphor layers were coated by freely dispersed coating process. Experimental study indicated that different gold wire bonding impacts the geometry of phosphor layer, and it results in different fluctuation trends of angular CCT at different spatial planes in one LED sample. It also results in various fluctuating amplitudes of angular CCT distributions at the same spatial plane for samples with different wire bonding angles. The gold wire bonding process has important impact on angular uniformity of CCT in LED package. © 2011 Optical Society of America

Development and Properties of Advanced Internal Magnesium Infiltration (AIMI) Processed MgB2 Wires

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

Collings, Prof Edward William; Sumption, Prof Michael D; Li, Guangze

The development, processing, properties, and formation mechanisms of Advanced Internal Magnesium Infiltration (AIMI) MgB2 wires are discussed against a background of the related and original processes, Internal-Magnesium-Diffusion (IMD) and Magnesium-Reactive-Liquid-Infiltration (Mg-RLI). First reviewed are the formation, properties and applications of Mg-RLI bulks as basis for discussions of Mg-RLI-processed and IMD-processed wires. The transition from Mg-RLI- and IMD- to AIMI wires is explained, and the relative performances of powder-in-tube (PIT), IMD and AIMI wires are summarized in the form of an iso-Je diagram of Jc,nb versus Anb/ATOT in which ATOT, Anb, Jc,nb, and Je are, respectively, the wire s cross-sectional area,more » the area inside the chemical barrier, the critical current (Ic) normalized to Anb, and Ic normalized to ATOT. After the details of AIMI wire fabrication selection of starting powders, dopants, and reaction heat treatments are introduced the report goes on to describe in detail the development of high performance AIMI wires: layer Jcs, fill factors, Jes, and the effects of wire size, multifilamentarization, doping with C, and co-doping with C and Dy2O3. The two-stage mechanism of layer formation in AIMI wires is discussed: first the reactive infiltration of liquid Mg into a porous B pack, a process that terminates with the formation of a dense MgB2 layer; second the slow diffusion of Mg into any remaining B through that MgB2 layer. The report concludes with a brief general discussion of anisotropy, current percolation, and the Jc field dependence of MgB2 wires.« less

In Situ Electrochemical Deposition of Microscopic Wires

NASA Technical Reports Server (NTRS)

Yun, Minhee; Myung, Nosang; Vasquez, Richard

2005-01-01

A method of fabrication of wires having micron and submicron dimensions is built around electrochemical deposition of the wires in their final positions between electrodes in integrated circuits or other devices in which the wires are to be used. Heretofore, nanowires have been fabricated by a variety of techniques characterized by low degrees of controllability and low throughput rates, and it has been necessary to align and electrically connect the wires in their final positions by use of sophisticated equipment in expensive and tedious post-growth assembly processes. The present method is more economical, offers higher yields, enables control of wire widths, and eliminates the need for post-growth assembly. The wires fabricated by this method could be used as simple electrical conductors or as transducers in sensors. Depending upon electrodeposition conditions and the compositions of the electroplating solutions in specific applications, the wires could be made of metals, alloys, metal oxides, semiconductors, or electrically conductive polymers. In this method, one uses fabrication processes that are standard in the semiconductor industry. These include cleaning, dry etching, low-pressure chemical vapor deposition, lithography, dielectric deposition, electron-beam lithography, and metallization processes as well as the electrochemical deposition process used to form the wires. In a typical case of fabrication of a circuit that includes electrodes between which microscopic wires are to be formed on a silicon substrate, the fabrication processes follow a standard sequence until just before the fabrication of the microscopic wires. Then, by use of a thermal SiO-deposition technique, the electrodes and the substrate surface areas in the gaps between them are covered with SiO. Next, the SiO is electron-beam patterned, then reactive-ion etched to form channels having specified widths (typically about 1 m or less) that define the widths of the wires to be formed. Drops of an electroplating solution are placed on the substrate in the regions containing the channels thus formed, then the wires are electrodeposited from the solution onto the exposed portions of the electrodes and into the channels. The electrodeposition is a room-temperature, atmospheric-pressure process. The figure shows an example of palladium wires that were electrodeposited into 1-mm-wide channels between gold electrodes.

Recovery of process water from spent emulsions generated in copper cable factory.

PubMed

Karakulski, K; Morawski, A W

2011-02-28

Treatment of waste emulsions generated in the cable factory from copper wire drawing was investigated using the integrated membrane processes: ultrafiltration (UF) and nanofiltration (NF). The application of UF tubular membranes (MWCO 100 kDa) resulted in 98% retention of oil and lubricants, whereas the degree of passage of copper ions (the major component of effluents from cable factory) was 99%. The average permeate flux amounted to 45 l/m(2) h for the transmembrane pressure of 3.5 bar during the UF pretreatment of waste emulsions. The Silt Density Index (SDI) values of UF permeates were appropriate for the application of spiral wound membranes in the NF process. The complete removal of oil and lubricants was achieved in NF process and the content of TOC was reduced by more than 90%. The rejection of copper ions in the NF process was 90% and 98% for NF270 and NF90 membranes (FILMTEC), respectively. The quality of NF permeates allows a direct reuse of treated water for the preparation of fresh emulsion. Copyright © 2010 Elsevier B.V. All rights reserved.

Sociocultural Knowledge and Visual Re(-)Presentations of Black Masculinity and Community: Reading "The Wire" for Critical Multicultural Teacher Education

ERIC Educational Resources Information Center

Brown, Keffrelyn D.; Kraehe, Amelia

2011-01-01

In this article we consider the implications of using popular visual media as a pedagogic tool for helping teachers acquire critical sociocultural knowledge to work more effectively with students of color, particularly Black males. Drawing from a textual analysis (McKee 2001, 2003; Rose 2001) conducted in the critical visual studies tradition…

The Influence of Pd-Doped Au Wire Bonding on HAZ Microstructure and Looping Profile in Micro-Electromechanical Systems (MEMS) Packaging

NASA Astrophysics Data System (ADS)

Ismail, Roslina; Omar, Ghazali; Jalar, Azman; Majlis, Burhanuddin Yeop

2015-07-01

Wire bonding processes has been widely adopted in micro-electromechanical systems (MEMS) packaging especially in biomedical devices for the integration of components. In the first process sequence in wire bonding, the zone along the wire near the melted tips is called the heat-affected zone (HAZ). The HAZ plays an important factor that influenced the looping profiles of wire bonding process. This paper investigates the effect of dopants on microstructures in the HAZ. One precent palladium (Pd) was added to the as-drawn 4N gold wire and annealed at 600°C. The addition of Pd was able to moderate the grain growth in the HAZ by retarding the heat propagation to the wire. In the formation of the looping profile, the first bending point of the looping is highly associated with the length of the HAZ. The alloyed gold wire (2N gold) has a sharp angle at a distance of about 30 m from the neck of the wire with a measured bending radius of about 40 mm and bending angle of about 40° clockwise from vertical axis, while the 4N gold wire bends at a longer distance. It also shows that the HAZ for 4N gold is longer than 2N gold wire.

Method and apparatus for forming high-critical-temperature superconducting layers on flat and/or elongated substrates

DOEpatents

Ciszek, Theodore F.

1994-01-01

An elongated, flexible superconductive wire or strip is fabricated by pulling it through and out of a melt of metal oxide material at a rate conducive to forming a crystalline coating of superconductive metal oxide material on an elongated, flexible substrate wire or strip. A coating of crystalline superconductive material, such as Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8, is annealed to effect conductive contact between adjacent crystalline structures in the coating material, which is then cooled to room temperature. The container for the melt can accommodate continuous passage of the substrate through the melt. Also, a second pass-through container can be used to simultaneously anneal and overcoat the superconductive coating with a hot metallic material, such as silver or silver alloy. A hollow, elongated tube casting method of forming an elongated, flexible superconductive wire includes drawing the melt by differential pressure into a heated tubular substrate.

Method and apparatus for forming high-critical-temperature superconducting layers on flat and/or elongated substrates

DOEpatents

Ciszek, T.F.

1994-04-19

An elongated, flexible superconductive wire or strip is fabricated by pulling it through and out of a melt of metal oxide material at a rate conducive to forming a crystalline coating of superconductive metal oxide material on an elongated, flexible substrate wire or strip. A coating of crystalline superconductive material, such as Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8], is annealed to effect conductive contact between adjacent crystalline structures in the coating material, which is then cooled to room temperature. The container for the melt can accommodate continuous passage of the substrate through the melt. Also, a second pass-through container can be used to simultaneously anneal and overcoat the superconductive coating with a hot metallic material, such as silver or silver alloy. A hollow, elongated tube casting method of forming an elongated, flexible superconductive wire includes drawing the melt by differential pressure into a heated tubular substrate. 8 figures.

Telecommunications administration standard

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

Gustwiller, K.D.

1996-05-01

The administration of telecommunications is critical to proper maintenance and operation. The intent is to be able to properly support telecommunications for the distribution of all information within a building/campus. This standard will provide a uniform administration scheme that is independent of applications, and will establish guidelines for owners, installers, designers and contractors. This standard will accommodate existing building wiring, new building wiring and outside plant wiring. Existing buildings may not readily adapt to all applications of this standard, but the requirement for telecommunications administration is applicable to all buildings. Administration of the telecommunications infrastructure includes documentation (labels, records, drawings,more » reports, and work orders) of cables, termination hardware, patching and cross-connect facilities, telecommunications rooms, and other telecommunications spaces (conduits, grounding, and cable pathways are documented by Facilities Engineering). The investment in properly documenting telecommunications is a worthwhile effort. It is necessary to adhere to these standards to ensure quality and efficiency for the operation and maintenance of the telecommunications infrastructure for Sandia National Laboratories.« less

Prediction of multi performance characteristics of wire EDM process using grey ANFIS

NASA Astrophysics Data System (ADS)

Kumanan, Somasundaram; Nair, Anish

2017-09-01

Super alloys are used to fabricate components in ultra-supercritical power plants. These hard to machine materials are processed using non-traditional machining methods like Wire cut electrical discharge machining and needs attention. This paper details about multi performance optimization of wire EDM process using Grey ANFIS. Experiments are designed to establish the performance characteristics of wire EDM such as surface roughness, material removal rate, wire wear rate and geometric tolerances. The control parameters are pulse on time, pulse off time, current, voltage, flushing pressure, wire tension, table feed and wire speed. Grey relational analysis is employed to optimise the multi objectives. Analysis of variance of the grey grades is used to identify the critical parameters. A regression model is developed and used to generate datasets for the training of proposed adaptive neuro fuzzy inference system. The developed prediction model is tested for its prediction ability.

Permanent wire splicing by an explosive joining process

NASA Technical Reports Server (NTRS)

Bement, Laurence J. (Inventor); Kushnick, Anne C. (Inventor)

1991-01-01

The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebent, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires, and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity, angular collision between the mating surfaces. This collision creates surface melts and collision bonding results in electron sharing linkups.

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

Takai, Yoshizo; Kawasaki, Tadahiro; Kimura, Yoshihide

A single-atom-sized gold wire was successfully observed in real time by a newly developed defocus-image modulation processing electron microscope. Because of phase retrieval processing with spherical aberration correction, the single-atom strand wire was observed with high contrast and without contrast blurring. By carefully looking at the atomic distance, the contrast, and the dynamic behavior of the wire, we recognized that there are two stages of the wire. In the first stage the wire maintained the atomic distance in the bulk crystal, but in the second stage the wire showed the atomic distance of the nearest-neighbor atoms with weaker contrast. Themore » gold wire was rather stable for a few seconds under strong electron beam illumination.« less

Tapered capillary optics

DOEpatents

Hirsch, Gregory

1998-01-01

A metal or glass wire is etched with great precision into a very narrowly tapering cone which has the shape of the desired final capillary-optics bore. By controlling the rate of removal of the wire from an etchant bath, a carefully controlled taper is produced. A sensor measures the diameter of the wire as it leaves the surface of the etchant. This signal is used for feedback control of the withdrawal speed. The etched wire undergoes a treatment to produce an extremely low surface-roughness. The etched and smoothed wire is coated with the material of choice for optimizing the reflectivity of the radiation being focused. This could be a vacuum evaporation, sputtering, CVD or aqueous chemical process. The coated wire is either electroplated, built up with electroless plating, or encapsulated in a polymer cylinder such as epoxy to increase the diameter of the wire for easier handling and greater robustness. During this process, the wire is vertically oriented and tensioned to assure that the wire is absolutely straight. The coated and electroformed wire is bonded to a flat, rigid substrate and is then periodically segmented by cutting or etching a series of narrow slits or grooves into the wire. The wire is vertically oriented and tensioned during the bonding process to assure that it is straight. The original wire material is then chemically etched away through the slits or otherwise withdrawn to leave the hollow internal bore of the final tapered-capillary optical element.

Process water reduction in a wire milling operation. 1989 summer intern report

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

Alberg, J.

1989-12-31

Johnson Filtration Systems is a company located in New Brighton, Minnesota which employs 256 people. The focus of the project was to reduce the water usage of the wire milling operation. Water in the milling process is used to clean the wire and cool the mill components. Total annual water usage for this operation is six million gallons. The milling process changes the cross sectional shape of the wire by using flattening hammers and rollers. A synthetic coolant is used to enhance this process and remove heat. The coolant is removed from the wire as it is pulled through amore » squeegee, washed it with water and dried with an air knife.« less

Intelligent Software for System Design and Documentation

NASA Technical Reports Server (NTRS)

2002-01-01

In an effort to develop a real-time, on-line database system that tracks documentation changes in NASA's propulsion test facilities, engineers at Stennis Space Center teamed with ECT International of Brookfield, WI, through the NASA Dual-Use Development Program to create the External Data Program and Hyperlink Add-on Modules for the promis*e software. Promis*e is ECT's top-of-the-line intelligent software for control system design and documentation. With promis*e the user can make use of the automated design process to quickly generate control system schematics, panel layouts, bills of material, wire lists, terminal plans and more. NASA and its testing contractors currently use promis*e to create the drawings and schematics at the E2 Cell 2 test stand located at Stennis Space Center.

Promising More Information

NASA Technical Reports Server (NTRS)

2003-01-01

When NASA needed a real-time, online database system capable of tracking documentation changes in its propulsion test facilities, engineers at Stennis Space Center joined with ECT International, of Brookfield, Wisconsin, to create a solution. Through NASA's Dual-Use Program, ECT developed Exdata, a software program that works within the company's existing Promise software. Exdata not only satisfied NASA s requirements, but also expanded ECT s commercial product line. Promise, ECT s primary product, is an intelligent software program with specialized functions for designing and documenting electrical control systems. An addon to AutoCAD software, Promis e generates control system schematics, panel layouts, bills of material, wire lists, and terminal plans. The drawing functions include symbol libraries, macros, and automatic line breaking. Primary Promise customers include manufacturing companies, utilities, and other organizations with complex processes to control.

A MEMS sensor for AC electric current

NASA Astrophysics Data System (ADS)

Leland, Eli Sidney

This manuscript describes the development of a new MEMS sensor for the measurement of AC electric current. The sensor is comprised of a MEMS piezoelectric cantilever with a microscale permanent magnet mounted to the cantilever's free end. When placed near a wire carrying AC current, the magnet couples to the oscillating magnetic field surrounding the wire, causing the cantilever to deflect, and piezoelectric coupling produces a sinusoidal voltage proportional to the current in the wire. The sensor is itself passive, requiring no power supply to operate. It also operates on proximity and need only be placed near a current carrier in order to function. The sensor does not need to encircle the current carrier and it therefore can measure current in two-wire zip-cords without necessitating the separation of the two conductors. Applications for tins sensor include measuring residential and commercial electricity use and monitoring electric power distribution networks. An analytical model describing the behavior of the current sensor was developed. This model was also adapted to describe the power output of an energy scavenger coupled to a wire carrying AC current. A mesoscale sensor exhibited a sensitivity of 75 mV/A when measuring AC electric current in a zip-cord. A mesoscale energy scavenger produced 345 muW when coupled to a zip-cord carrying 13 A. MEMS current sensors were fabricated from aluminum nitride piezoelectric cantilevers and composite permanent magnets. The cantilevers were fabricated using a four-mask process. Microscale permanent magnets were dispenser-printed using NdFeB magnetic powder with an epoxy binder. The MEMS AC current sensor was interfaced with amplification circuitry and packaged inside an almninum enclosure. The sensor was also integrated with a mesoscale energy scavenger and power conditioning circuitry to create a fully self-powered current sensor. Unamplified sensitivity of the sensor was 0.1-1.1 mV/A when measuring currents in single wires and zip-cords. The self-powered current sensor operated at a 0.6% duty cycle when coupled to the zip-cord of a 1500 W space heater drawing 13 A. The self-powered sensor's energy scavenger transferred energy to a 10 mF storage capacitor at a rate of 69 muJ/s.

Energetic additive manufacturing process with feed wire

DOEpatents

Harwell, Lane D.; Griffith, Michelle L.; Greene, Donald L.; Pressly, Gary A.

2000-11-07

A process for additive manufacture by energetic wire deposition is described. A source wire is fed into a energy beam generated melt-pool on a growth surface as the melt-pool moves over the growth surface. This process enables the rapid prototyping and manufacture of fully dense, near-net shape components, as well as cladding and welding processes. Alloys, graded materials, and other inhomogeneous materials can be grown using this process.

PCACE- PERSONAL COMPUTER AIDED CABLING ENGINEERING

NASA Technical Reports Server (NTRS)

Billitti, J. W.

1994-01-01

A computerized interactive harness engineering program has been developed to provide an inexpensive, interactive system which is designed for learning and using an engineering approach to interconnection systems. PCACE is basically a database system that stores information as files of individual connectors and handles wiring information in circuit groups stored as records. This directly emulates the typical manual engineering methods of data handling, thus making the user interface to the program very natural. Data files can be created, viewed, manipulated, or printed in real time. The printed ouput is in a form ready for use by fabrication and engineering personnel. PCACE also contains a wide variety of error-checking routines including connector contact checks during hardcopy generation. The user may edit existing harness data files or create new files. In creating a new file, the user is given the opportunity to insert all the connector and harness boiler plate data which would be part of a normal connector wiring diagram. This data includes the following: 1) connector reference designator, 2) connector part number, 3) backshell part number, 4) cable reference designator, 5) cable part number, 6) drawing revision, 7) relevant notes, 8) standard wire gauge, and 9) maximum circuit count. Any item except the maximum circuit count may be left blank, and any item may be changed at a later time. Once a file is created and organized, the user is directed to the main menu and has access to the file boiler plate, the circuit wiring records, and the wiring records index list. The organization of a file is such that record zero contains the connector/cable boiler plate, and all other records contain circuit wiring data. Each wiring record will handle a circuit with as many as nine wires in the interface. The record stores the circuit name and wire count and the following data for each wire: 1) wire identifier, 2) contact, 3) splice, 4) wire gauge if different from standard, 5) wire/group type, 6) wire destination, and 7) note number. The PCACE record structure allows for a wide variety of wiring forms using splices and shields, yet retains sufficient structure to maintain ease of use. PCACE is written in TURBO Pascal 3.0 and has been implemented on IBM PC, XT, and AT systems under DOS 3.1 with a memory of 512K of 8 bit bytes, two floppy disk drives, an RGB monitor, and a printer with ASCII control characters. PCACE was originally developed in 1983, and the IBM version was released in 1986.

A biomechanical analysis of sublaminar and subtransverse process fixation using metal wires and polyethylene cables.

PubMed

Fujita, Masaru; Diab, Mohammad; Xu, Zheng; Puttlitz, Christian M

2006-09-01

An in vitro biomechanical calf thoracic spine study. To evaluate the biomechanical stability of sublaminar and subtransverse process fixation using stainless steel wires and ultra-high molecular weight polyethylene (UHMWPE) cables. It is commonly held that transverse process fixation provides less stability than sublaminar fixation. To our knowledge, this is the first biomechanical study to compare the stability afforded by sublaminar fixation and subtransverse process fixation using metal wire and UHMWPE cable before and after cyclic loading. There were 6 fresh-frozen calf thoracic spines (T4-T9) used to determine the sublaminar fixation stiffness and subtransverse process fixation stiffness in each group. Double strands of 18-gauge stainless steel wire, 3 and 5 mm-width UHMWPE cable (Nesplon; Alfresa, Inc., Osaka, Japan) were applied to each spine. Cyclic pure flexion-extension moment loading (2 Nm, 0.5 Hz, 5000 cycles) was applied after the initial stability was analyzed by measuring the range of motion. Statistical analyses were used to delineate differences between the various experimental groups. Subtransverse process wiring was more stable than sublaminar wiring after cyclic loading in flexion-extension (P < 0.05). There were no significant differences between each group in lateral bending and axial rotation after cyclic loading. Sublaminar stainless steel wiring was more stable than sublaminar 3 and 5-mm cable before and after cyclic loading in axial rotation (P < 0.01). Acute subtransverse process fixation using 3-mm cable was less stable after cyclic loading in axial rotation (P < 0.05). All other groups did not produce statistically significant differences. Subtransverse process fixation provides at least as much stability as sublaminar fixation. A 5-mm UHMWPE cable and stainless steel wire result in equivalent sublaminar and subtransverse process stability.

Laser Hot Wire Process: A Novel Process for Near-Net Shape Fabrication for High-Throughput Applications

NASA Astrophysics Data System (ADS)

Kottman, Michael; Zhang, Shenjia; McGuffin-Cawley, James; Denney, Paul; Narayanan, Badri K.

2015-03-01

The laser hot wire process has gained considerable interest for additive manufacturing applications, leveraging its high deposition rate, low dilution, thermal stability, and general metallurgical control including the ability to introduce and preserve desired meta-stable phases. Recent advancements in closed-loop process control and laser technology have increased productivity, process stability, and control of deposit metallurgy. The laser hot wire process has shown success in several applications: repairing and rejuvenating casting dies, depositing a variety of alloys including abrasion wear-resistant overlays with solid and tubular wires, and producing low-dilution (<5%) nickel alloy overlays for corrosion applications. The feasibility of fabricating titanium buildups is being assessed for aerospace applications.

Superconductor Composite

DOEpatents

Dorris, Stephen E.; Burlone, Dominick A.; Morgan; Carol W.

1999-02-02

A superconducting conductor fabricated from a plurality of wires, e.g., fine silver wires, coated with a superconducting powder. A process of applying superconducting powders to such wires, to the resulting coated wires and superconductors produced therefrom.

Enamel Insulated Copper Wire in Electric Motors: Sliding Behavior and Possible Damage Mechanisms During Die Bending

NASA Astrophysics Data System (ADS)

Demiri, Albion

This study investigates the sliding friction and the forming behaviour of enamel insulated copper wire during the die-forming process. It also aims to determine potential damage mechanisms to the wire during bending process for electric motor coils. In this investigation a wire-bending machine was designed and built in order to simulate the wire forming process in a laboratory scale. Bending angle of the wire and the bending radii were used to control the strain on the wire surface. The effect of speed on COF was investigated for different speeds of of 1, 5, 10, 15, and 20mm/s. A positive correlation was observed between the COF and the testing speed. Additionally, the effect of strain on COF was studied for 2% and 23% to determine its influence on the COF. A general trend was observed of decreased COF with increased strain in wires. Finally, the ability of the enamel coating to resist external damage and wire strain was investigated by tensile testing of pre-scratched magnet wire. The results showed that wire enamel can withstand significant surface damage prior to breach and failure. The insulating polymer coating failed under the scratch tests at 20N load using a Rockwell indenter and at 5N load using a 90° conical steel indenter. Additional tests, such as tensile testing, scratch testing and reciprocating friction testing, were used to characterize the mechanical and tribological properties of the enamel insulated copper wire.

Aluminum-Scandium: A Material for Semiconductor Packaging

NASA Astrophysics Data System (ADS)

Geissler, Ute; Thomas, Sven; Schneider-Ramelow, Martin; Mukhopadhyay, Biswajit; Lang, Klaus-Dieter

2016-10-01

A well-known aluminum-scandium (Al-Sc) alloy, already used in lightweight sports equipment, is about to be established for use in electronic packaging. One application for Al-Sc alloy is manufacture of bonding wires. The special feature of the alloy is its ability to harden by precipitation. The new bonding wires with electrical conductivity similar to pure Al wires can be processed on common wire bonders for aluminum wedge/wedge (w/w) bonding. The wires exhibit very fine-grained microstructure. Small Al3Sc particles are the main reason for its high strength and prevent recrystallization and grain growth at higher temperatures (>150°C). After the wire-bonding process, the interface is well closed. Reliability investigations by active power cycling demonstrated considerably improved lifetime compared with pure Al heavy wires. Furthermore, the Al-Sc alloy was sputter-deposited onto silicon wafer to test it as chip metallization in copper (Cu) ball/wedge bonding technology. After deposition, the layers exhibited fine-grained columnar structure and small coherent Al3Sc particles with dimensions of a few nanometers. These particles inhibit softening processes such as Al splashing in fine wire bonding processes and increase the thickness of remnant Al under the copper balls to 85% of the initial thickness.

Fabrication of Microstripline Wiring for Large Format Transition Edge Sensor Arrays

NASA Technical Reports Server (NTRS)

Chervenak, James A.; Adams, J. M.; Bailey, C. N.; Bandler, S.; Brekosky, R. P.; Eckart, M. E.; Erwin, A. E.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.;

Engineered pinning landscapes for enhanced 2G coil wire

DOE PAGES

Rupich, Martin W.; Sathyamurthy, Srivatsan; Fleshler, Steven; ...

2016-04-01

We demonstrate a twofold increase in the in-field critical current of AMSC's standard 2G coil wire by irradiation with 18-MeV Au ions. The optimum pinning enhancement is achieved with a dose of 6 × 10 11 Au ions/cm 2. Although the 77 K, self-field critical current is reduced by about 35%, the in-field critical current (H//c) shows a significant enhancement between 4 and 50 K in fields > 1 T. The process was used for the roll-to-roll irradiation of AMSC's standard 46-mm-wide production coated conductor strips, which were further processed into standard copper laminated coil wire. The long-length wires showmore » the same enhancement as attained with short static irradiated samples. The roll-to-roll irradiation process can be incorporated in the standard 2G wire manufacturing, with no modifications to the current process. In conclusion, the enhanced performance of the wire will benefit rotating machine and magnet applications.« less

Carbon nanotube wires with continuous current rating exceeding 20 Amperes

NASA Astrophysics Data System (ADS)

Cress, Cory D.; Ganter, Matthew J.; Schauerman, Christopher M.; Soule, Karen; Rossi, Jamie E.; Lawlor, Colleen C.; Puchades, Ivan; Ubnoske, Stephen M.; Bucossi, Andrew R.; Landi, Brian J.

2017-07-01

A process to fabricate carbon nanotube (CNT) wires with diameters greater than 1 cm and continuous current carrying capability exceeding 20 A is demonstrated. Wires larger than 5 mm are formed using a multi-step radial densification process that begins with a densified CNT wire core followed by successive wrapping of additional CNT material to increase the wire size. This process allows for a wide range of wire diameters to be fabricated, with and without potassium tetrabromoaurate (KAuBr4) chemical doping, and the resulting electrical and thermal properties to be characterized. Electrical measurements are performed with on/off current steps to obtain the maximum current before reaching a peak CNT wire temperature of 100 °C and before failure, yielding values of instantaneous currents in excess of 45 A for KAuBr4 doped CNT wires with a diameter of 6 mm achieved prior to failure. The peak temperature of the wires at failure (˜530 °C) is correlated with the primary decomposition peak observed in thermal gravimetric analysis of a wire sample confirming that oxidation is the primary failure mode of CNT wires operated in air. The in operando stability of doped CNT wires is confirmed by monitoring the resistance and temperature, which remain largely unaltered over 40 days and 1 day for wires with 1.5 mm and 11.2 mm diameters, respectively. The 100 °C continuous current rating, or ampacity, is measured for a range of doped CNT wire diameters and corresponding linear mass densities ρL. To describe the results, a new form of the fuse-law, where the critical current is defined as I ∝ρL3 /4, is developed and shows good agreement with the experimental data. Ultimately, CNT wires are shown to be stable electrical conductors, with failure current densities in excess of 50 A in the case of a convectively cooled 11.2 mm doped CNT wire, and amenable for use in applications that have long-term, high-current demands.

Training children aged 5-10 years in manual compliance control to improve drawing and handwriting.

PubMed

Bingham, Geoffrey P; Snapp-Childs, Winona

2018-04-12

A large proportion of school-aged children exhibit poor drawing and handwriting. This prevalence limits the availability of therapy. We developed an automated method for training improved manual compliance control and relatedly, prospective control of a stylus. The approach included a difficult training task, while providing parametrically modifiable support that enables the children to perform successfully while developing good compliance control. The task was to use a stylus to push a bead along a 3D wire path. Support was provided by making the wire magnetically attractive to the stylus. Support was progressively reduced as 3D tracing performance improved. We report studies that (1) compared performance of Typically Developing (TD) children and children with Developmental Coordination Disorder (DCD), (2) tested training with active versus passive movement, (3) tested progressively reduced versus constant or no support during training, (4) tested children of different ages, (5) tested the transfer of training to a drawing task, (6) tested the specificity of training in respect to the size, shape and dimensionality of figures, and (7) investigated the relevance of the training task to the Beery VMI, an inventory used to diagnose DCD. The findings were as follows. (1) Pre-training performance of TD and DCD children was the same and good with high support but distinct and poor with low support. Support yielded good self-efficacy that motivated training. Post training performance with no support was improved and the same for TD and DCD children. (2) Actively controlled movements were required for improved performance. (3) Progressively reduced support was required for good performance during and after training. (4) Age differences in performance during pre-training were eliminated post-training. (5) Improvements transferred to drawing. (6) There was no evidence of specificity of training in transfer. (7) Disparate Beery scores were reflected in pre-training but not post-training performance. We conclude that the method improves manual compliance control, and more generally, prospective control of movements used in drawing performance. Copyright © 2018. Published by Elsevier B.V.

Synergistic responses of superficial chemistry and micro topography of titanium created by wire-type electric discharge machining.

PubMed

Kataoka, Yu; Tamaki, Yukimichi; Miyazaki, Takashi

2011-01-01

Wire-type electric discharge machining has been applied to the manufacture of endosseous titanium implants as this computer associated technique allows extremely accurate complex sample shaping with an optimal micro textured surface during the processing. Since the titanium oxide layer is sensitively altered by each processing, the authors hypothesized that this technique also up-regulates biological responses through the synergistic effects of the superficial chemistry and micro topography. To evaluate the respective in vitro cellular responses on the superficial chemistry and micro topography of titanium surface processed by wire-type electric discharge, we used titanium-coated epoxy resin replica of the surface. An oxide layer on the titanium surface processed by wire-type electric discharge activated the initial responses of osteoblastic cells through an integrin-mediated mechanism. Since the mRNA expression of ALP on those replicas was up-regulated compared to smooth titanium samples, the micro topography of a titanium surface processed by wire-type electric discharge promotes the osteogenic potential of cells. The synergistic response of the superficial chemistry and micro topography of titanium processed by wire-type electric discharge was demonstrated in this study.

Composite ceramic superconducting wires for electric motor applications

NASA Astrophysics Data System (ADS)

Holloran, John W.

1989-07-01

Progress is described on developing Y-123 wire for an HTSC motor. The wire development involves synthesis of Y-123 powder, spinning polymer containing green fiber, heat treating the fiber to produce metallized superconducting filaments, and characterizing the electrical properties. A melt spinning process was developed for producing 125-micron diameter green fiber containing 50 vol percent Y-123. This fiber can be braided for producing transposed multifilamentary wire. A process was developed to coat green fiber with silver alloys which can be continuous sintering. A second process for multifilamentary ribbon wire is also being developed. The Y-123 filaments have 77 deg self-field Jc values up to 2600 A/sq cm, but Jc is reduced to 10 A/cm squared at 800 G. Preliminary data is presented on mechanical properties. A dc homopolar motor with an iron magnetic circuit is being designed to operate with early HTSC wire.

Electromagnetic Nondestructive Evaluation of Wire Insulation and Models of Insulation Material Properties

NASA Technical Reports Server (NTRS)

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.

Splicing Wires Permanently With Explosives

NASA Technical Reports Server (NTRS)

Bement, Laurence J.; Kushnick, Anne C.

1990-01-01

Explosive joining process developed to splice wires by enclosing and metallurgically bonding wires within copper sheets. Joints exhibit many desirable characteristics, 100-percent conductivity and strength, no heat-induced annealing, no susceptibility to corrosion in contacts between dissimilar metals, and stability at high temperature. Used to join wires to terminals, as well as to splice wires. Applicable to telecommunications industry, in which millions of small wires spliced annually.

Structure and thermomechanical behavior of NiTiPt shape memory alloy wires.

PubMed

Lin, Brian; Gall, Ken; Maier, Hans J; Waldron, Robbie

2009-01-01

The objective of this work is to understand the structure-property relationships in polycrystalline NiTiPt (Ti 42.7 at.% Ni 7.5 at %Pt) with a composition showing pseudoelasticity at ambient temperatures. Structural characterization of the alloy includes grain size determination and texture analysis while the thermomechanical properties are explored using tensile testing. Variation in heat treatment is used as a vehicle to modify microstructure. The results are compared to experiments on Ni-rich NiTi alloy wires (Ti-51.0 at.% Ni), which are in commercial use in various biomedical applications. With regards to microstructure, both alloys exhibit a <111> fiber texture along the wire drawing axis; however, the NiTiPt alloy grain size is smaller than that of the Ni-rich NiTi wires, while the latter materials contain second-phase precipitates. Given the nanometer-scale grain size in NiTiPt and the dispersed, nanometer-scale precipitate size in NiTi, the overall strength and ductility of the alloys are essentially identical when given appropriate heat treatments. Property differences include a much smaller stress hysteresis and smaller temperature dependence of the transformation stress for NiTiPt alloys compared to NiTi alloys. Potential benefits and implications for use in vascular stent applications are discussed.

Progress toward a tungsten alloy wire/high temperature alloy composite turbine blade

NASA Technical Reports Server (NTRS)

Ritzert, F. J.; Dreshfield, R. L.

1992-01-01

A tungsten alloy wire reinforced high temperature alloy composite is being developed for potential application as a hollow turbine blade for advanced rocket engine turbopumps. The W-24Re-HfC alloy wire used for these composite blades provides an excellent balance of strength and wire ductility. Preliminary fabrication, specimen design, and characterization studies were conducted by using commercially available W218 tungsten wire in place of the W-24Re-Hfc wire. Subsequently, two-ply, 50 vol pct composite panels using the W-24Re-HfC wire were fabricated. Tensile tests and metallographic studies were performed to determine the material viability. Tensile strengths of a Waspaloy matrix composite at 870 C were 90 pct of the value expected from rule-of-mixtures calculations. During processing of this Waspaloy matrix composite, a brittle phase was formed at the wire/matrix interface. Circumferential wire cracks were found in this phase. Wire coating and process evaluation efforts were performed in an attempt to solve the reaction problem. Although problems were encountered in this study, wire reinforced high temperature alloy composites continue to show promise for turbopump turbine blade material improvement.

Influence of Wire Electrical Discharge Machining (WEDM) process parameters on surface roughness

NASA Astrophysics Data System (ADS)

Yeakub Ali, Mohammad; Banu, Asfana; Abu Bakar, Mazilah

2018-01-01

In obtaining the best quality of engineering components, the quality of machined parts surface plays an important role. It improves the fatigue strength, wear resistance, and corrosion of workpiece. This paper investigates the effects of wire electrical discharge machining (WEDM) process parameters on surface roughness of stainless steel using distilled water as dielectric fluid and brass wire as tool electrode. The parameters selected are voltage open, wire speed, wire tension, voltage gap, and off time. Empirical model was developed for the estimation of surface roughness. The analysis revealed that off time has a major influence on surface roughness. The optimum machining parameters for minimum surface roughness were found to be at a 10 V open voltage, 2.84 μs off time, 12 m/min wire speed, 6.3 N wire tension, and 54.91 V voltage gap.

Dynamical analysis of surface-insulated planar wire array Z-pinches

NASA Astrophysics Data System (ADS)

Li, Yang; Sheng, Liang; Hei, Dongwei; Li, Xingwen; Zhang, Jinhai; Li, Mo; Qiu, Aici

2018-05-01

The ablation and implosion dynamics of planar wire array Z-pinches with and without surface insulation are compared and discussed in this paper. This paper first presents a phenomenological model named the ablation and cascade snowplow implosion (ACSI) model, which accounts for the ablation and implosion phases of a planar wire array Z-pinch in a single simulation. The comparison between experimental data and simulation results shows that the ACSI model could give a fairly good description about the dynamical characteristics of planar wire array Z-pinches. Surface insulation introduces notable differences in the ablation phase of planar wire array Z-pinches. The ablation phase is divided into two stages: insulation layer ablation and tungsten wire ablation. The two-stage ablation process of insulated wires is simulated in the ACSI model by updating the formulas describing the ablation process.

Shuttleless toroid winder

DOEpatents

Lindenmeyer, Carl W.

1981-01-01

A lower support receives a toroid at a winding station with the axis of the toroid aligned with a slot in the support. An upper guide member applies an axial force to hold the toroid against the lower support. A pair of movable jaws carried by an indexing mechanism engage the outer surface of the toroid to apply a radial holding force. While the toroid is thus held, a wire is placed axially through the toroid, assisted by a funnel-shaped surface in the upper guide member, and is drawn tight about the toroid by a pair of cooperating draw rollers. When operated in the "full cycle" mode, the operator then actuates a switch which energizes a power drive to release the axial clamp and to drive the indexing mechanism and the jaws to rotate the toroid about its axis. At the same time, the wire is ejected from the draw rollers beneath the toroid so that the operator may grasp it to form another loop. When the toroid is fully indexed, the jaws release it, and the upper guide member is returned to clamp the toroid axially while the indexing mechanism is returned to its starting position. The apparatus may also be operated in a "momentary contact" mode in which the mechanism is driven only for the time a switch is actuated.

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

Rupich, Martin W.; Sathyamurthy, Srivatsan; Fleshler, Steven

We demonstrate a twofold increase in the in-field critical current of AMSC's standard 2G coil wire by irradiation with 18-MeV Au ions. The optimum pinning enhancement is achieved with a dose of 6 × 10 11 Au ions/cm 2. Although the 77 K, self-field critical current is reduced by about 35%, the in-field critical current (H//c) shows a significant enhancement between 4 and 50 K in fields > 1 T. The process was used for the roll-to-roll irradiation of AMSC's standard 46-mm-wide production coated conductor strips, which were further processed into standard copper laminated coil wire. The long-length wires showmore » the same enhancement as attained with short static irradiated samples. The roll-to-roll irradiation process can be incorporated in the standard 2G wire manufacturing, with no modifications to the current process. In conclusion, the enhanced performance of the wire will benefit rotating machine and magnet applications.« less

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

Rupich, Martin W.; Sathyamurthy, Srivatsan; Fleshler, Steven

We demonstrate a twofold increase in the in-field critical current of AMSC's standard 2G coil wire by irradiation with 18-MeV Au ions. The optimum pinning enhancement is achieved with a dose of 6 x 10(11) Au ions/cm(2). Although the 77 K, self-field critical current is reduced by about 35%, the in-field critical current (H//c) shows a significant enhancement between 4 and 50 K in fields > 1 T. The process was used for the roll-to-roll irradiation of AMSC's standard 46-mm-wide production coated conductor strips, which were further processed into standard copper laminated coil wire. The long-length wires show the samemore » enhancement as attained with short static irradiated samples. The roll-to-roll irradiation process can be incorporated in the standard 2G wire manufacturing, with no modifications to the current process. The enhanced performance of the wire will benefit rotating machine and magnet applications.« less

Effect of cold drawing ratio on γ′ precipitation in Inconel X-750

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

Ha, Jeong Won; Research and Development Center, KOS Limited, Yangsan 626-230; Seong, Baek Seok

2014-10-15

Inconel X-750 is a Ni-based precipitation-hardened superalloy having large tensile and fracture strengths. In the study, X-750 wires were cold drawn to different extents. Small angle neutron scattering was employed to quantitatively measure the size and volume fraction of the γ′ phase as a function of the cold drawing ratio (DR) and aging temperature. The presence and size of γ′ precipitates were confirmed by transmission electron microscopy. The drawing ratio had an important effect on the volume fraction of the γ′ precipitates. However, the size of the precipitates was independent on the drawing ratio. The specimen with the minimum drawingmore » ratio (DR0) produced the largest volume fraction of γ′ as compared with large drawing ratio (DR) specimens such as DR17 and DR42. The small volume fraction of the γ′ phase for a sizeable drawing ratio was associated with the large amount of nucleation sites for secondary carbides, M{sub 23}C{sub 6}, and the fast diffusion path, i.e., dislocation, needed to form M{sub 23}C{sub 6}. A Cr depletion zone around the secondary carbides raised the solubility of γ′. Therefore, the significant drawing ratio contributing to the large volume fraction of the secondary carbides decreased the volume fraction of the γ′ precipitates in Inconel X-750. - Highlights: • The volume fraction of secondary carbides increased with the drawing ratio. • The volume fraction of γ′ decreased as the drawing ratio increased. • The drawing ratio affected the γ′ volume fraction with no variation of the γ' size. • The volume fraction of γ′ was affected by the secondary carbide volume fraction.« less

Formation of Bi2Sr2CaCu2O x /Ag multifilamentary metallic precursor powder-in-tube wires

NASA Astrophysics Data System (ADS)

Zhang, Yun; Koch, Carl C.; Schwartz, Justin

2016-12-01

Previously, a metallic precursor (MP) approach to synthesizing Bi2Sr2CaCu2O x (Bi2212), with a homogeneous mixture of Bi, Sr, Ca, Cu and Ag was produced by mechanical alloying. Here, Bi2212/Ag round multifilamentary wire is manufactured using a metallic precursor powder-in-tube (MPIT) process. The MP powders were packed into a pure Ag tube in an Ar atmosphere and then sealed. After deformation, multifilamentary round wires and rolled tapes were heat treated in flowing oxygen through three stages: oxidation, conversion and partial-melt processing (PMP). Processing-microstructure-property relationships on 20-50 mm long multifilamentary round wires and rolled tapes were studied extensively. It is shown that conventional wire deformation processes, optimized for oxide-powder-in-tube wires, are not effective for deforming MPIT wires, and that as with prior studies of MPIT Bi2Sr2Ca2Cu3O y conductors, hot extrusion is required for obtaining a multifilamentary structure with fine filaments. As a result, the Bi2212 MPIT wires reported here have low engineering critical current density. Nonetheless, by focusing on sections of wires that remain intact after deformation, it is also shown that the first heat treatment stage, the oxidation stage, plays a crucial role in chemical homogeneity, phase transformation, and microstructural evolution and three reaction pathways for MP oxidation are presented. Furthermore, it is found the Bi2212 grain alignment within an MPIT filament is significantly different from that found in OPIT filaments after PMP, indicating the formation of highly dense filaments containing Bi2212 fine grains and Ag particles before PMP aids the formation of large, c-axis textured Bi2212 filaments during PMP. These results show that, with improved wire deformation, high critical current density may be obtained via a MPIT process.

Monte Carlo design of optimal wire mesh collimator for breast tumor imaging process

NASA Astrophysics Data System (ADS)

Saad, W. H. M.; Roslan, R. E.; Mahdi, M. A.; Choong, W.-S.; Saion, E.; Saripan, M. I.

2011-08-01

This paper presents the modeling of breast tumor imaging process using wire mesh collimator gamma camera. Previous studies showed that the wire mesh collimator has a potential to improve the sensitivity of the tumor detection. In this paper, we extend our research significantly, to find an optimal configuration of the wire mesh collimator specifically for semi-compressed breast tumor detection, by looking into four major factors: weight, sensitivity, spatial resolution and tumor contrast. The numbers of layers in the wire mesh collimator is varied to optimize the collimator design. The statistical variations of the results are studied by simulating multiple realizations for each experiment using different starting random numbers. All the simulation environments are modeled using Monte Carlo N-Particle Code (MCNP). The quality of the detection is measured directly by comparing the sensitivity, spatial resolution and tumor contrast of the images produced by the wire mesh collimator and benchmarked that with a standard multihole collimator. The proposed optimal configuration of the wire mesh collimator is optimized by selecting the number of layers in wire mesh collimator, where the tumor contrast shows a relatively comparable value to the multihole collimator, when it is tested with uniformly semi-compressed breast phantom. The wire mesh collimator showed higher number of sensitivity because of its loose arrangement while the spatial resolution of wire mesh collimator does not shows much different compared to the multihole collimator. With a relatively good tumor contrast and spatial resolution, and increased in sensitivity, a new proposed wire mesh collimator gives a significant improvement in the wire mesh collimator design for breast cancer imaging process. The proposed collimator configuration is reduced to 44.09% from the total multihole collimator weight.

[Contrast of Z-Pinch X-Ray Yield Measure Technique].

PubMed

Li, Mo; Wang, Liang-ping; Sheng, Liang; Lu, Yi

2015-03-01

Resistive bolometer and scintillant detection system are two mainly Z-pinch X-ray yield measure techniques which are based on different diagnostic principles. Contrasting the results from two methods can help with increasing precision of X-ray yield measurement. Experiments with different load material and shape were carried out on the "QiangGuang-I" facility. For Al wire arrays, X-ray yields measured by the two techniques were largely consistent. However, for insulating coating W wire arrays, X-ray yields taken from bolometer changed with load parameters while data from scintillant detection system hardly changed. Simulation and analysis draw conclusions as follows: (1) Scintillant detection system is much more sensitive to X-ray photons with low energy and its spectral response is wider than the resistive bolometer. Thus, results from the former method are always larger than the latter. (2) The responses of the two systems are both flat to Al plasma radiation. Thus, their results are consistent for Al wire array loads. (3) Radiation form planar W wire arrays is mainly composed of sub-keV soft X-ray. X-ray yields measured by the bolometer is supposed to be accurate because of the nickel foil can absorb almost all the soft X-ray. (4) By contrast, using planar W wire arrays, data from scintillant detection system hardly change with load parameters. A possible explanation is that while the distance between wires increases, plasma temperature at stagnation reduces and spectra moves toward the soft X-ray region. Scintillator is much more sensitive to the soft X-ray below 200 eV. Thus, although the total X-ray yield reduces with large diameter load, signal from the scintillant detection system is almost the same. (5) Both Techniques affected by electron beams produced by the loads.

Butt Welding Joint of Aluminum Alloy by Space GHTA Welding Process in Vacuum

NASA Astrophysics Data System (ADS)

Suita, Yoshikazu; Shinike, Shuhei; Ekuni, Tomohide; Terajima, Noboru; Tsukuda, Yoshiyuki; Imagawa, Kichiro

Aluminum alloys have been used widely in constructing various space structures including the International Space Station (ISS) and launch vehicles. For space applications, welding experiments on aluminum alloy were performed using the GHTA (Gas Hollow Tungsten Arc) welding process using a filler wire feeder in a vacuum. We investigated the melting phenomenon of the base metal and filler wire, bead formation, and the effects of wire feed speed on melting characteristics. The melting mechanism in the base metal during the bead on a plate with wire feed was similar to that for the melt run without wire feed. We clarified the effects of wire feed speed on bead sizes and configurations. Furthermore, the butt welded joint welded using the optimum wire feed speed, and the joint tensile strengths were evaluated. The tensile strength of the square butt joint welded by the pulsed DC GHTA welding with wire feed in a vacuum is nearly equal to that of the same joint welded by conventional GTA (Gas Tungsten Arc) welding in air.

An Investigation into the Comparative Costs of Additive Manufacture vs. Machine from Solid for Aero Engine Parts

DTIC Science & Technology

2006-05-01

welding power sources are not totally efficient at converting power drawn from the wall into heat energy used for the welding process . TIG sources are...Powder bed + Laser • Wire + Laser • Wire + Electron Beam • Wire + TIG Each system has its own unique attributes in terms of process variables...relative economics of producing a near net shape by Additive Manufacturing (AM) processes compared with traditional machine from solid processes (MFS

Superconducting MgB2 wires with vanadium diffusion barrier

NASA Astrophysics Data System (ADS)

Hušek, I.; Kováč, P.; Melišek, T.; Kulich, M.; Rosová, A.; Kopera, L.; Szundiová, B.

2017-10-01

Single-core MgB2 wires with a vanadium barrier and Cu stabilization have been made by the in situ powder-in-tube (PIT) and internal magnesium diffusion (IMD) into boron processes. Heat treatment of PIT wires was done at the temperature range of 650 °C-850 °C/30 min. Critical currents of differently treated MgB2/V/Cu wires have been measured and related with the structure of MgB2. It was found that critical current density of MgB2/V wire annealed above 700 °C decreases rapidly. The obtained results clearly show that vanadium is a well formable metal and can be applied as an effective diffusion barrier for MgB2 wires heat-treated at temperatures ≤700 °C. This temperature limit is well applicable for MgB2 wires with high current densities made by PIT and also by the IMD process.

Present status of PIT round wires of 122-type iron-based superconductors

NASA Astrophysics Data System (ADS)

Tamegai, T.; Suwa, T.; Pyon, S.; Kajitani, H.; Takano, K.; Koizumi, N.; Awaji, S.; Watanabe, K.

2017-12-01

Outstanding characteristics with high T c and H c2 and small anisotropy in iron-based superconductors (IBSs) have triggered the development of superconducting wires and tapes using these novel superconductors. In this short article, developments and present status of round wires of 122-type IBSs are reviewed. By introducing hot-isostatic pressing (HIP) technique, J c in round wires of 122-type IBSs has been improved significantly. Further improvements have been realized by refining the fabrication process of the core material and introducing partial texturing of the wire core. The largest transport J c for round wires at 4.2 K at self-field and 100 kOe are 2.0x105 A/cm2 and 3.8x104 A/cm2, respectively. We also compare the J c characteristics of wires and tapes processed by HIP.

The Effects of Operational Parameters on a Mono-wire Cutting System: Efficiency in Marble Processing

NASA Astrophysics Data System (ADS)

Yilmazkaya, Emre; Ozcelik, Yilmaz

2016-02-01

Mono-wire block cutting machines that cut with a diamond wire can be used for squaring natural stone blocks and the slab-cutting process. The efficient use of these machines reduces operating costs by ensuring less diamond wire wear and longer wire life at high speeds. The high investment costs of these machines will lead to their efficient use and reduce production costs by increasing plant efficiency. Therefore, there is a need to investigate the cutting performance parameters of mono-wire cutting machines in terms of rock properties and operating parameters. This study aims to investigate the effects of the wire rotational speed (peripheral speed) and wire descending speed (cutting speed), which are the operating parameters of a mono-wire cutting machine, on unit wear and unit energy, which are the performance parameters in mono-wire cutting. By using the obtained results, cuttability charts for each natural stone were created on the basis of unit wear and unit energy values, cutting optimizations were performed, and the relationships between some physical and mechanical properties of rocks and the optimum cutting parameters obtained as a result of the optimization were investigated.

Scale-up of 2G wire manufacturing at American Superconductor Corporation

NASA Astrophysics Data System (ADS)

Fleshler, S.; Buczek, D.; Carter, B.; Cedrone, P.; DeMoranville, K.; Gannon, J.; Inch, J.; Li, X.; Lynch, J.; Otto, A.; Podtburg, E.; Roy, D.; Rupich, M.; Sathyamurthy, S.; Schreiber, J.; Thieme, C.; Thompson, E.; Tucker, D.; Nagashima, K.; Ogata, M.

2009-10-01

American Superconductor Corporation (AMSC) has developed the base technology and a manufacturing line for initial volume production of low-cost second generation high temperature superconductor (2G HTS) wire for commercial and military applications. The manufacturing line is based on reel-to-reel processing of wide HTS strips using rolling assisted bi-axially textured substrate (RABiTS™) for the template and Metal Organic Deposition (MOD) for the HTS layer. AMSC’s wide strip process is a low cost manufacturing technology since multiple wires are produced in a single manufacturing pass by slitting the wide strip to narrower width in the last stage of the manufacturing process. Industry standard 4.4 mm wide wires are produced by laminating metallic foils, such as copper, stainless steel or any other material, to the HTS insert wire, and are chosen to tailor the electrical, thermal and mechanical properties of the wire for specific applications. The laminated, 4.4 mm wide wires are known as “344 superconductors.” In this paper, we summarize the status of AMSC’s manufacturing capability, the performance of the wire presently being produced, as well as the cost and technical advantages of AMSC’s manufacturing approach. In addition, future direction for research and development to improve electrical performance is presented.

[Extensive injuries due to high-tension electrical current].

PubMed

Tomásek, D; Königová, R; Snupárek, Z

1989-03-01

The authors submit a case of severe injury with high tension electric current. They emphasize the necessity of prevention of this injury which occurs most frequently when transformer stations are not adequately safeguarded, in case of inadequate protection when approaching trolley wires on the railway track, and when safety principles are not respected during work on the railway. The authors draw attention to the importance of immediate resuscitation and multidisciplinary comprehensive care.

A comparison study of exploding a Cu wire in air, water, and solid powders

NASA Astrophysics Data System (ADS)

Han, Ruoyu; Wu, Jiawei; Ding, Weidong; Zhou, Haibin; Qiu, Aici; Wang, Yanan

2017-11-01

In this paper, an experimental study on exploding a copper wire in air, water, incombustible powders, and energetic materials is performed. We examined the effects of the surrounding media on the explosion process and its related phenomena. Experiments were first carried out with copper wire explosions driven by microsecond timescale pulsed currents in air, water, and the half-half case. Then, the copper wires were exploded in air, water, SiO2 powders, quartz sand, NaCl powders, and energetic-material cylinders, respectively. Our experimental results indicated that the explosion process was significantly influenced by the surrounding media, resulting in noticeable differences in energy deposition, optical emission, and shock waves. In particular, incombustible powders could throttle the current flow completely when a fine wire was adopted. We also found that an air or incombustible-powder layer could drastically attenuate the shock wave generated by a wire explosion. As for energetic-material loads, obvious discrepancies were found in voltage/current waveforms from vaporization when compared with a wire explosion in air/water, which meant the metal vapor/liquid drops play a significant role in the ignition process.

Investigation of the degradation mechanism of catalytic wires during oxidation of ammonia process

NASA Astrophysics Data System (ADS)

Pura, Jarosław; Wieciński, Piotr; Kwaśniak, Piotr; Zwolińska, Marta; Garbacz, Halina; Zdunek, Joanna; Laskowski, Zbigniew; Gierej, Maciej

2016-12-01

The most common catalysts for the ammonia oxidation process are 80 μm diameter platinum-rhodium wires knitted or woven into the form of a gauze. In an aggressive environment and under extreme conditions (temperature 800-900 °C, intensive gas flow, high pressure) precious elements are drained from the surface of the wires. Part of this separated material quickly decomposes on the surface in the form of characteristic "cauliflower-shape protrusions". The rest of the platinum is captured by palladium-nickel catalytic-capture gauzes located beneath. In our investigation we focused on the effects of the degradation of gauzes from one industrial catalytic system. The aim of the study was to compare the degree and the mechanism of degradation of gauzes from a different part of the reactor. The study covered PtRh7 catalytic and PdNi5 catalytic-capture gauzes. X-ray computer microtomography investigation revealed that despite strong differences in morphology, each Pt-Rh wire has a similar specific surface area. This indicates that the oxidation process and morphological changes of the wires occur in a self-regulating balance, resulting in the value of the specific surface area of the catalyst. Microtomography analysis of Pd-Ni wires revealed strong redevelopment of the wires' surface, which is related to the platinum capture phenomenon. Scanning electron microscope observations also revealed the nanostructure in the cauliflower-shape protrusions and large grains in the wires' preserved cores. The high temperature in the reactor and the long-term nature of the process do not favor the occurrence of the nanostructure in this type of material. Further and detailed analysis of this phenomena will provide a better understanding of the precious metals etching and deposition processes during oxidation.

Analytical methods to characterize heterogeneous raw material for thermal spray process: cored wire Inconel 625

NASA Astrophysics Data System (ADS)

Lindner, T.; Bonebeau, S.; Drehmann, R.; Grund, T.; Pawlowski, L.; Lampke, T.

2016-03-01

In wire arc spraying, the raw material needs to exhibit sufficient formability and ductility in order to be processed. By using an electrically conductive, metallic sheath, it is also possible to handle non-conductive and/or brittle materials such as ceramics. In comparison to massive wire, a cored wire has a heterogeneous material distribution. Due to this fact and the complex thermodynamic processes during wire arc spraying, it is very difficult to predict the resulting chemical composition in the coating with sufficient accuracy. An Inconel 625 cored wire was used to investigate this issue. In a comparative study, the analytical results of the raw material were compared to arc sprayed coatings and droplets, which were remelted in an arc furnace under argon atmosphere. Energy-dispersive X-ray spectroscopy (EDX) and X-ray fluorescence (XRF) analysis were used to determine the chemical composition. The phase determination was performed by X-ray diffraction (XRD). The results were related to the manufacturer specifications and evaluated in respect to differences in the chemical composition. The comparison between the feedstock powder, the remelted droplets and the thermally sprayed coatings allows to evaluate the influence of the processing methods on the resulting chemical and phase composition.

Thermoelectric Mechanism and Interface Characteristics of Cyanide-Free Nanogold-Coated Silver Wire

NASA Astrophysics Data System (ADS)

Tseng, Yi-Wei; Hung, Fei-Yi; Lui, Truan-Sheng

2016-01-01

Traditional bath-plated gold contains a cyanide complex, which is an environmental hazard. In response, our study used a green plating process to produce cyanide-free gold-coated silver (cyanide-free ACA) bonding wire that has been proven to be a feasible alternative to gold bonding wire in semiconductor packaging. In this work, ACA wire annealed at 550°C was found to have stable microstructure and superior mechanical properties. Intermetallic compounds Ag2Al and AuAl2 grew from Ag-Au balls and Al pads after aging at 175°C for 500 h. After current testing, ACA wire was found to have improved electrical properties due to equiaxed grain growth. The gold nanolayer on the Ag surface increased the oxidation resistance. These results provide insights regarding the reliability of ACA wire in advanced bonding processes.

Observation of fast expansion velocity with insulating tungsten wires on ∼80 kA facility

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

Li, M.; Li, Y.; State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Xi'an 710024

2016-07-15

This paper presents experimental results on the effects of insulating coatings on tungsten planar wire array Z-pinches on an 80 kA, 100 ns current facility. Expansion velocity is obviously increased from ∼0.25 km/s to ∼3.5 km/s by using the insulating coatings. It can be inferred that the wire cores are in gaseous state with this fast expansion velocity. An optical framing camera and laser probing images show that the standard wire arrays have typical ablation process which is similar to their behaviors on mega-ampere facilities. The ablation process and precursor plasma are suppressed for dielectric tungsten wires. The wire array implosion might be improvedmore » if these phenomena can be reproduced on Mega-ampere facilities.« less

Wiring Damage Analyses for STS OV-103

NASA Technical Reports Server (NTRS)

Thomas, Walter, III

2006-01-01

This study investigated the Shuttle Program s belief that Space Transportation System (STS) wiring damage occurrences are random, that is, a constant occurrence rate. Using Problem Reporting and Corrective Action (PRACA)-derived data for STS Space Shuttle OV-103, wiring damage was observed to increase over the vehicle s life. Causal factors could include wiring physical deterioration, maintenance and inspection induced damage, and inspection process changes resulting in more damage events being reported. Induced damage effects cannot be resolved with existent data. Growth analysis (using Crow-AMSAA, or CA) resolved maintenance/inspection effects (e.g., heightened awareness) on all wire damages and indicated an overall increase since Challenger Return-to-Flight (RTF). An increasing failure or occurrence rate per flight cycle was seen for each wire damage mode; these (individual) rates were not affected by inspection process effects, within statistical error.

Fatigue failure of regenerator screens in a high frequency Stirling engine

NASA Technical Reports Server (NTRS)

Hull, David R.; Alger, Donald L.; Moore, Thomas J.; Scheuermann, Coulson M.

1988-01-01

Failure of Stirling Space Power Demonstrator Engine (SPDE) regenerator screens was investigated. After several hours of operation the SPDE was shut down for inspection and on removing the regenator screens, debris of unknown origin was discovered along with considerable cracking of the screens in localized areas. Metallurgical analysis of the debris determined it to be cracked-off-deformed pieces of the 41 micron thickness Type 304 stainless steel wire screen. Scanning electron microscopy of the cracked screens revealed failures occurring at wire crossovers and fatigue striations on the fracture surface of the wires. Thus, the screen failure can be characterized as a fatigue failure of the wires. The crossovers were determined to contain 30 percent reduction in wire thickness and a highly worked microstructure occurring from the manufacturing process of the wire screens. Later it was found that reduction in wire thickness occurred because the screen fabricator had subjected it to a light cold-roll process after weaving. Installation of this screen left a clearance in the regenerator allowing the screens to move. The combined effects of the reduction in wire thickness, stress concentration (caused by screen movement), and highly worked microstructure at the wire crossovers led to the fatigue failure of the screens.

Operation and force analysis of the guide wire in a minimally invasive vascular interventional surgery robot system

NASA Astrophysics Data System (ADS)

Yang, Xue; Wang, Hongbo; Sun, Li; Yu, Hongnian

2015-03-01

To develop a robot system for minimally invasive surgery is significant, however the existing minimally invasive surgery robots are not applicable in practical operations, due to their limited functioning and weaker perception. A novel wire feeder is proposed for minimally invasive vascular interventional surgery. It is used for assisting surgeons in delivering a guide wire, balloon and stenting into a specific lesion location. By contrasting those existing wire feeders, the motion methods for delivering and rotating the guide wire in blood vessel are described, and their mechanical realization is presented. A new resistant force detecting method is given in details. The change of the resistance force can help the operator feel the block or embolism existing in front of the guide wire. The driving torque for rotating the guide wire is developed at different positions. Using the CT reconstruction image and extracted vessel paths, the path equation of the blood vessel is obtained. Combining the shapes of the guide wire outside the blood vessel, the whole bending equation of the guide wire is obtained. That is a risk criterion in the delivering process. This process can make operations safer and man-machine interaction more reliable. A novel surgery robot for feeding guide wire is designed, and a risk criterion for the system is given.

Laser Wire Stripper

NASA Technical Reports Server (NTRS)

1983-01-01

NASA-developed space shuttle technology is used in a laser wire stripper designed by Raytheon Company. Laser beams cut through insulation on a wire without damaging conductive metal, because laser radiation that melts plastic insulation is reflected by the metal. The laser process is fast, clean, precise and repeatable. It eliminates quality control problems and the expense of rejected wiring.

Dual-Wavelength Interferometry and Light Emission Study for Experimental Support of Dual-Wire Ablation Experiments

NASA Astrophysics Data System (ADS)

Hamilton, Andrew; Caplinger, James; Sotnikov, Vladimir; Sarkisov, Gennady; Leland, John

2017-10-01

In the Plasma Physics and Sensors Laboratory, located at Wright Patterson Air Force Base, we utilize a pulsed power source to create plasma through a wire ablation process of metallic wires. With a parallel arrangement of wires the azimuthal magnetic fields generated around each wire, along with the Ohmic current dissipation and heating occurring upon wire evaporation, launch strong radial outflows of magnetized plasmas towards the centralized stagnation region. It is in this region that we investigate two phases of the wire ablation process. Observations in the first phase are collsionless and mostly comprised of light ions ejected from the initial corona. The second phase is observed when the wire core is ablated and heavy ions dominate collisions in the stagnation region. In this presentation we will show how dual-wavelength interferometric techniques can provide information about electron and atomic densities from experiments. Additionally, we expect white-light emission to provide a qualitative confirmation of the instabilities observed from our experiments. The material is based upon work supported by the Air Force Office of Scientific Research under Award Number 16RYCOR289.

Model-Based Testability Assessment and Directed Troubleshooting of Shuttle Wiring Systems

NASA Technical Reports Server (NTRS)

Deb, Somnath; Domagala, Chuck; Shrestha, Roshan; Malepati, Venkatesh; Cavanaugh, Kevin; Patterson-Hine, Ann; Sanderfer, Dwight; Cockrell, Jim; Norvig, Peter (Technical Monitor)

2000-01-01

We have recently completed a pilot study on the Space shuttle wiring system commissioned by the Wiring Integrity Research (WIRe) team at NASA Ames Research Center, As the space shuttle ages, it is experiencing wiring degradation problems including arcing, chaffing insulation breakdown and broken conductors. A systematic and comprehensive test process is required to thoroughly test and quality assure (QA) the wiring systems. The NASA WIRe team recognized the value of a formal model based analysis for risk-assessment and fault coverage analysis. However. wiring systems are complex and involve over 50,000 wire segments. Therefore, NASA commissioned this pilot study with Qualtech Systems. Inc. (QSI) to explore means of automatically extracting high fidelity multi-signal models from wiring information database for use with QSI's Testability Engineering and Maintenance System (TEAMS) tool.

Explosive Spot Joining of Metals

NASA Technical Reports Server (NTRS)

Bement, Laurence J. (Inventor); Perry, Ronnie B. (Inventor)

1997-01-01

The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebend, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires. and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity. angular collision between the mating surfaces. This collision creates surface melts and collision bonding resulting in electron-sharing linkups.

Process for Nondestructive Evaluation of the Quality of a Crimped Wire Connector

NASA Technical Reports Server (NTRS)

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

2014-01-01

A process and apparatus for collecting data for nondestructive evaluation of the quality of a crimped wire connector are provided. The process involves providing a crimping tool having an anvil and opposing jaw for crimping a terminal onto a stranded wire, moving the jaw relative to the anvil to close the distance between the jaw and the anvil and thereby compress the terminal against the wire, while transmitting ultrasonic waves that are propagated through the terminal-wire combination and received at a receiving ultrasonic transducer as the jaw is moved relative to the anvil, and detecting and recording the position of the jaw relative to the anvil as a function of time and detecting and recording the amplitude of the ultrasonic wave that is received at the receiving ultrasonic transducer as a function of time as the jaw is moved relative to the anvil.

Corrosion of stainless steel sternal wire after long-term implantation.

PubMed

Tomizawa, Yasuko; Hanawa, Takao; Kuroda, Daisuke; Nishida, Hiroshi; Endo, Masahiro

2006-01-01

A variety of metallic components have been used in medical devices where lifelong durability and physical strength are demanded. To investigate the in vivo changes of implanted metallic medical devices in humans, stainless steel sternal wires removed from patients were evaluated. Stainless steel (316L) sternal wires removed from four patients after 10, 13, 22, and 30 years of implantation were evaluated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Macroscopically, the removed specimens maintained their metallic luster and color. Under SEM, small holes were observed sporadically at 10 years and they tended to connect in the drawing direction. The longer the implanted duration, the more numerous and deeper were the crevices observed. By EDS, sulfur, phosphorus, and calcium were identified in all areas at 10 years, in addition to the component elements of stainless steel, comprising iron, chromium, nickel, and manganese. Corrosion products observed at 30 years were identified as calcium phosphate. In conclusion, stainless steel sternal wires develop corroded pores that grow larger and deeper with time after implantation; however, the pores remain shallow even after decades of implantation and they may not be a cause of mechanical failure. An amount of metal ions equivalent to the corroded volume must have been released into the human body, but the effect of these metal ions on the body is not apparent.

Copper, Aluminum and Nickel: A New Monocrystalline Orthodontic Alloy

NASA Astrophysics Data System (ADS)

Wierenga, Mark

Introduction: This study was designed to evaluate, via tensile and bend testing, the mechanical properties of a newly-developed monocrystalline orthodontic archwire comprised of a blend of copper, aluminum, and nickel (CuAlNi). Methods: The sample was comprised of three shape memory alloys; CuAlNi, copper nickel titanium (CuNiTi), and nickel titanium (NiTi); from various orthodontic manufacturers in both 0.018" round and 0.019" x 0.025" rectangular dimensions. Additional data was gathered for similarly sized stainless steel and beta-titanium archwires as a point of reference for drawing conclusions about the relative properties of the archwires. Measurements of loading and unloading forces were recorded in both tension and deflection testing. Repeated-measure ANOVA (alpha= 0.05) was used to compare loading and unloading forces across wires and one-way ANOVA (alpha= 0.05) was used to compare elastic moduli and hysteresis. To identify significant differences, Tukey post-hoc comparisons were performed. Results: The modulus of elasticity, deflection forces, and hysteresis profiles of CuAlNi were significantly different than the other superelastic wires tested. In all tests, CuAlNi had a statistically significant lower modulus of elasticity compared to the CuNiTi and NiTi wires (P <0.0001). The CuAlNi wire exhibited significantly lower loading and unloading forces than any other wire tested. In round wire tensile tests, loading force at all deflections was significantly lower for CuAlNi than CuNiTi or NiTi (P <0.0001). In tensile testing, the CuAlNi alloy was able to recover from a 7 mm extension (10% elongation) without permanent deformation and with little to no loss in force output. In large-deflection bend tests at 4, 5, and 6 mm deflection, CuAlNi showed the significantly lowest loading forces across the three wire materials (P <0.0001). The NiTi wires showed up to 12 times the amount of energy loss due to hysteresis compared to CuAlNi. CuAlNi showed a hysteresis loss that was significantly less than any other wire tested in this study (P <0.0001). Conclusions: The relatively constant force delivered for a long period of time during the deactivation of this wire, the minimal hysteresis loss, the low force output in deflection, and the relatively low modulus of elasticity suggest that CuAlNi wires should be considered an important material addition to orthodontic metallurgy.

Corrosion resistance of premodeled wires made of stainless steel used for heart electrotherapy leaders

NASA Astrophysics Data System (ADS)

Przondziono, J.; Walke, W.; Młynarski, R.; Szatka, W.

2012-05-01

The purpose of the study is to evaluate resistance to electrochemical corrosion of wire made of X10CrNi18-8 stainless steel designed for use in cardiology treatment. The influence of strain formed in the premodeling process and methods of wire surface preparation to corrosive resistance in artificial plasma solution were analysed. Wire corrosion tests were carried out in the solution of artificial plasma. Resistance to electrochemical corrosion was evaluated on the ground of recorded curves of anodic polarization by means of potentiodynamic method. Potentiodynamic tests carried out enabled to determine how the resistance to pitting corrosion of wire changes, depending on strain formed in the premodeling process as well as on the method of wire surface preparation. For evaluation of phenomena occurring on the surface of tested steel, electrochemical impedance spectroscopy (EIS) was applied. Deterioration of corrosive properties of wire along with the increase in the formed strain hardening was observed.

Curvature effect on the mechanical behaviour of a martensitic shape-memory-alloy wire for applications in civil engineering

NASA Astrophysics Data System (ADS)

Tran, Hanh; Balandraud, Xavier; Destrebecq, Jean-François

2015-02-01

The mechanical response of a bent shape memory alloy (SMA) wire is a key point for the understanding of the process of the creation of confining effects in a wrapped concrete cylinder for example. The objective of the present study is to model the phenomena involved in the bending of a martensitic SMA wire. The mechanism of martensite reorientation is considered in the model, which also takes into account the asymmetry between tension and compression. For validation purposes, experiments were performed on Ni-Ti wires: measurement of residual curvatures after bending release and tensile tests on pre-bent wires. In particular, the analysis shows a variation in axial stiffness as a function of the preliminary curvature. This result shows the necessity of modelling the distributions of the state variables within the wire cross-section for the simulation of confinement processes using SMA wires. It also opens prospects to potential application to the bending of SMA fibres in smart textiles.

Superconductor-insulator transition in long MoGe nanowires.

PubMed

Kim, Hyunjeong; Jamali, Shirin; Rogachev, A

2012-07-13

The properties of one-dimensional superconducting wires depend on physical processes with different characteristic lengths. To identify the process dominant in the critical regime we have studied the transport properties of very narrow (9-20 nm) MoGe wires fabricated by advanced electron-beam lithography in a wide range of lengths, 1-25  μm. We observed that the wires undergo a superconductor-insulator transition (SIT) that is controlled by cross sectional area of a wire and possibly also by the width-to-thickness ratio. The mean-field critical temperature decreases exponentially with the inverse of the wire cross section. We observed that a qualitatively similar superconductor-insulator transition can be induced by an external magnetic field. Our results are not consistent with any currently known theory of the SIT. Some long superconducting MoGe nanowires can be identified as localized superconductors; namely, in these wires the one-electron localization length is much smaller than the length of a wire.

Electrical wire insulation and electromagnetic coil

DOEpatents

Bich, George J.; Gupta, Tapan K.

1984-01-01

An electromagnetic coil for high temperature and high radiation application in which glass is used to insulate the electrical wire. A process for applying the insulation to the wire is disclosed which results in improved insulation properties.

Development of explosively bonded TZM wire reinforced Columbian sheet composites

NASA Technical Reports Server (NTRS)

Otto, H. E.; Carpenter, S. H.

1972-01-01

Methods of producing TZM molybdenum wire reinforced C129Y columbium alloy composites by explosive welding were studied. Layers of TZM molybdenum wire were wound on frames with alternate layers of C129Y columbium alloy foil between the wire layers. The frames held both the wire and foils in place for the explosive bonding process. A goal of 33 volume percent molybdenum wire was achieved for some of the composites. Variables included wire diameter, foil thickness, wire separation, standoff distance between foils and types and amounts of explosive. The program was divided into two phases: (1) development of basic welding parameters using 5 x 10-inch composites, and (2) scaleup to 10 x 20-inch composites.

Comparison of X-ray Radiation Process in Single and Nested Wire Array Implosions

NASA Astrophysics Data System (ADS)

Li, Z. H.; Xu, Z. P.; Yang, J. L.; Xu, R. K.; Guo, C.; Grabovsky, E. V.; Oleynic, G. M.; Smirnov, V. P.

2006-01-01

In order to understanding the difference between tungsten single-wire-array and tungsten nested-wire-array Z-pinches, we have measured the x-ray power, the temporal-spatial distributions of x-ray radiation from each of the two loads. The measurements were performed with 0.1mm spatial and 1 ns temporal resolutions at 2.5- and 3.5-MA currents. The experimental conditions, including wire material, number of wires, wire-array length, electrode design, and implosion time, remained unchanged from shot to shot. Analysis of the radiation power profiles suggests that the nested-wire-array radiate slightly less x-ray energy in relatively shorter time interval than the single wire-array, leading to a much greater x-ray power in nested-wire-array implosion. The temporal-spatial distributions of x-ray power show that in both cases, plasmas formed by wire-array ablation radiate not simultaneously along load axis. For nested-wire-array Z-pinch, plasmas near the anode begin to radiate in 2ns later than that near the cathode. As a contrast, the temporal divergence of radiation among different plasma zones of single-wire-array Z-pinch along Z-axis is more than 6ns. Measurements of the x-ray emissions from small segments of pinch (2mm length along axis) indicate that local radiation power profiles almost do not vary for the two loads. Photographs taken by X-ray framing camera give a same description about the radiation process of pinch. One may expect that, as a result of this study, if the single-wire-array can be redesigned so ingeniously that the x-rays are emitted at the same time all over the pinch zone, the radiation power of single wire array Z-pinch may be much greater than what have been achieved.

A Critical Review of Heat Transfer Enhancement Techniques for Use in Marine Condensers.

DTIC Science & Technology

1982-09-01

horizontal tube, the Nusselt theory predicts that the condensate film is thinnest at the top of the tube, and thickens around the tube until at the...transfer coefficient. As pointed out above, the Nusselt analysis assumes that the condensate film drains from a horizontal tube in a continuous sheet...the condensate falling on the lower tubes does not deteriorate the thermal performance of these tubes because the helically - wrapped wires draw the

Application Of Numerical Modelling To Ribbed Wire Rod Dimensions Precision Increase

NASA Astrophysics Data System (ADS)

Szota, Piotr; Mróz, Sebastian; Stefanik, Andrzej

2007-05-01

The paper presents the results of theoretical and experimental investigations of the process of rolling square ribbed wire rod designed for concrete reinforcement. Numerical modelling of the process of rolling in the finishing and pre-finishing grooves was carried out using the Forge2005® software. In the investigation, particular consideration was given to the analysis of the effect of pre-finished band shape on the formation of ribs on the finished wire rod in the finishing groove. The results of theoretical studies were verified in experimental tests, which were carried out in a wire rolling mill.

Needleless electrospinning with twisted wire spinneret

NASA Astrophysics Data System (ADS)

Holopainen, Jani; Penttinen, Toni; Santala, Eero; Ritala, Mikko

2015-01-01

A needleless electrospinning setup named ‘Needleless Twisted Wire Electrospinning’ was developed. The polymer solution is electrospun from the surface of a twisted wire set to a high voltage and collected on a cylindrical collector around the wire. Multiple Taylor cones are simultaneously self-formed on the downward flowing solution. The system is robust and simple with no moving parts aside from the syringe pump used to transport the solution to the top of the wire. The structure and process parameters of the setup and the results on the preparation of polyvinyl pyrrolidone (PVP), hydroxyapatite (HA) and bioglass fibers with the setup are presented. PVP fiber sheets with areas of 40 × 120 cm2 and masses up to 1.15 g were prepared. High production rates of 5.23 g h-1 and 1.40 g h-1 were achieved for PVP and HA respectively. The major limiting factor of the setup is drying of the polymer solution on the wire during the electrospinning process which will eventually force to interrupt the process for cleaning of the wire. Possible solutions to this problem and other ways to develop the setup are discussed. The presented system provides a simple way to increase the production rate and area of fiber sheet as compared with the conventional needle electrospinning.

The 80 kV electrostatic wire septum for AmPS

NASA Astrophysics Data System (ADS)

Vanderlinden, A.; Bijleveld, J. H. M.; Rookhuizen, H. Boer; Bruinsma, P. J. T.; Heine, E.; Lassing, P.; Prins, E.

The characteristics of the wire septum for the Amsterdam Pulse Stretcher (AmPS) are summarized. In the extraction process of the AmPS the extracted beam is intercepted from the circulating beam by the 1 m long electrostatic wire septum. For a bending angle of 4.4 mrad, the maximum anode voltage is 80 kV. The system developed consists of a wire spacing of 0.65 mm between tungsten wires of 50 micrometers diameter. Stainless steel spring wires, bent in a half cylindrical carrier, stretch the septum wires two by two. Prototype tests were successful up to an anode voltage of 120 kV.

Could titanium oxide coating from a sol-gel process make stone baskets more resistant to laser radiation at 2.1 μm?

PubMed

Cordes, Jens; Nguyen, Felix; Heidenau, Frank; Jocham, Dieter

2012-10-19

Stone baskets could be easily destroyed by Holmium:YAG-laser at an endourologic treatment, with respect to this, we try to improve the resistance by coating them with a titanium oxide layer. The layer was established by a sol-gel-process. Six new baskets (Equadus, Opi Med, Ettlingen, Germany) were used: 1.8 Ch. with 4 wires (diameter 0.127 mm). Three baskets were coated with a layer of titanium oxide established by a sol-gel process at the BioCerEntwicklungs GmbH in Bayreuth (~100 nanometres thickness). The lithotripter was a Holmium:YAG laser (Auriga XL, Starmedtec, Starnberg, Germany). 10 uncoated and 10 coated wires were tested with 610 mJ (the minimal clinical setting) and 2 uncoated and 2 coated wires were tested with 110 mJ. The wires were locked in a special holding instrument under water and the laser incident angle was 90°. The endpoint was gross visible damage to the wire and loss of electric conduction. Only two coated wires resisted two pulses (one in the 610 mJ and one in the 110 mJ setting). All other wires were destroyed after one pulse. This was the first attempt at making stone baskets more resistant to a Holmium:YAG laser beam. Titanium oxide deposited by a sol-gel-process on a titanium-nickel alloy did not result in better resistance to laser injuries.

Fatigue failure of regenerator screens in a high frequency Stirling engine

NASA Technical Reports Server (NTRS)

Hull, David R.; Alger, Donald L.; Moore, Thomas J.; Scheuermann, Coulson M.

1987-01-01

Failure of Stirling Space Power Demonstrator Engine (SPDE) regenerator screens was investigated. After several hours of operation the SPDE was shut down for inspection and on removing the regenerator screens, debris of unknown origin was discovered along with considerable cracking of the screens in localized areas. Metallurgical analysis of the debris determined it to be cracked-off-deformed pieces of the 41 micron thickness Type 304 stainless steel wire screen. Scanning electron microscopy of the cracked screens revealed failures occurring at wire crossovers and fatigue striations on the fracture surface of the wires. Thus, the screen failure can be characterized as a fatigue failure of the wires. The crossovers were determined to contain a 30 percent reduction in wire thickness and a highly worked microstructure occurring from the manufacturing process of the wire screens. Later it was found that reduction in wire thickness occurred because the screen fabricator had subjected it to a light cold-roll process after weaving. Installation of this screen left a clearance in the regenerator allowing the screens to move. The combined effects of the reduction in wire thickness, stress concentration (caused by screen movement), and highly worked microstructure at the wire crossovers led to the fatigue failure of the screens.

Electron beam additive manufacturing with wire - Analysis of the process

NASA Astrophysics Data System (ADS)

Weglowski, Marek St.; Błacha, Sylwester; Pilarczyk, Jan; Dutkiewicz, Jan; Rogal, Łukasz

2018-05-01

The electron beam additive manufacturing process with wire is a part of global trend to find fast and efficient methods for producing complex shapes elements from costly metal alloys such as stainless steels, nickel alloys, titanium alloys etc. whose production by other conventional technologies is unprofitable or technically impossible. Demand for additive manufacturing is linked to the development of new technologies in the automotive, aerospace and machinery industries. The aim of the presented work was to carried out research on electron beam additive manufacturing with a wire as a deposited (filler) material. The scope of the work was to investigate the influence of selected technological parameters such as: wire feed rate, beam current, travelling speed, acceleration voltage on stability of the deposition process and geometric dimensions of the padding welds. The research revealed that, at low beam currents, the deposition process is unstable. The padding weld reinforcement is non-uniform. Irregularity of the width, height and straightness of the padding welds can be observed. At too high acceleration voltage and beam current, burn-through of plate and excess penetration weld can be revealed. The achieved results and gained knowledge allowed to produce, based on EBAM with wire process, whole structure from stainless steel.

Method for making radioactive metal articles having small dimensions

DOEpatents

Ohriner, Evan K.

2000-01-01

A method for making a radioactive article such as wire, includes the steps of providing a metal article having a first shape, such a cylinder, that is either radioactive itself or can be converted to a second, radioactive isotope by irradiation; melting the metal article one or more times; optionally adding an alloying metal to the molten metal in order to enhance ductility or other properties; placing the metal article having the first shape (e.g., cylindrical) into a cavity in the interior of an extrusion body (e.g., a cylinder having a cylindrical cavity therein); extruding the extrusion body and the article having the first shape located in the cavity therein, resulting in an elongated extrusion body and an article having a second shape; removing the elongated extrusion body, for example by chemical means, leaving the elongated inner article substantially intact; optionally repeating the extrusion procedure one or more times; and then drawing the elongated article to still further elongate it, into wire, foil, or another desired shape. If the starting metal is enriched in a radioactive isotope or a precursor thereof, the end product can provide a more intense radiation source than conventionally manufactured radioactive wire, foil, or the like.

The effect of mechano-chemical treatment on structural properties of the drawn TiNi-based alloy wire

NASA Astrophysics Data System (ADS)

Anikeev, Sergey; Hodorenko, Valentina; Gunther, Victor; Chekalkin, Timofey; Kang, Ji-hoon; Kang, Seung-baik

2018-01-01

The rapid development of biomedical materials with the advanced functional characteristics is a challenging task because of the growing demands for better material properties in-clinically employed. Modern medical devices that can be implanted into humans have evolved steadily by replacing TiNi-based alloys for titanium and stainless steel. In this study, the effect of the mechano-chemical treatment on structural properties of the matrix and surface layer of the drawn TiNi-based alloy wire was assessed. A range of samples have been prepared using different drawing and etching procedures. It is clear from the results obtained that the fabricated samples show a composite structure comprising the complex matrix and textured oxycarbonitride spitted surface layer. The suggested method of surface treatment is a concept to increase the surface roughness for the enhanced bio-performance and better in vivo integration.

Confining jackets for concrete cylinders using NiTiNb and NiTi shape memory alloy wires

NASA Astrophysics Data System (ADS)

Choi, Eunsoo; Nam, Tae-Hyun; Yoon, Soon-Jong; Cho, Sun-Kyu; Park, Joonam

2010-05-01

This study used prestrained NiTiNb and NiTi shape memory alloy (SMA) wires to confine concrete cylinders. The recovery stress of the wires was measured with respect to the maximal prestrain of the wires. SMA wires were preelongated during the manufacturing process and then wrapped around concrete cylinders of 150 mm×300 mm (phi×L). Unconfined concrete cylinders were tested for compressive strength and the results were compared to those of cylinders confined by SMA wires. NiTiNb SMA wires increased the compressive strength and ductility of the cylinders due to the confining effect. NiTiNb wires were found to be more effective in increasing the peak strength of the cylinders and dissipating energy than NiTi wires. This study showed the potential of the proposed method to retrofit reinforced concrete columns using SMA wires to protect them from earthquakes.

Understanding the densification process of Bi2Sr2CaCu2Ox round wires with overpressure processing and its effect on critical current density

PubMed Central

Matras, M. R.; Jiang, J.; Larbalestier, D. C.; Hellstrom, E. E.

2016-01-01

Overpressure (OP) processing increases the critical current density (JC) of Bi2Sr2CaCu2Ox (2212) round wires by shrinking the surrounding Ag matrix around the 2212 filaments, driving them close to full density and greatly increasing the 2212 grain connectivity. Indeed densification is vital for attaining the highest JC. Here, we investigate the time and temperature dependence of the wire densification. We find that the wire diameter decreases by 3.8 ± 0.3 % after full heat treatment at 50 atm and 100 atm OP. At 50 atm OP pressure, the filaments start densifying above 700 °C and reach a 3.30 ± 0.07 % smaller diameter after 2 h at 820 °C, which is below the melting point of 2212 powder. The densification is homogeneous and does not change the filament shape before melting. The growth of non-superconducting phases is observed at 820 °C, suggesting that time should be minimized at high temperature prior to melting the 2212 powder. Study of an open-ended 2.2 m long wire sample shows that full densification and the high OP JC (JC varies by about 3.1 times over the 2.2 m long wire) is reached about 1 m from the open ends, thus showing that coil-length wires can be protected from leaky seals by adding at least 1 m of sacrificial wire at each end. PMID:28479675

Using of fiber-array diagnostic to measure the propagation of fast axial ionization wave during breakdown of electrically exploding tungsten wire in vacuum.

PubMed

Shi, Huantong; Zou, Xiaobing; Wang, Xinxin

2017-12-01

The physical process of electrical explosion of wires in vacuum is featured with the surface discharge along the wire, which generates the corona plasma layer and terminates the Joule heating of the wire core. In this paper, a fiber-array probe was designed to directly measure the radiation of surface arc with spatial and temporal resolution. The radiation of the exploding wire was casted to the section of an optical-fiber-array by a lens and transmitted to PIN diodes and finally collected with an oscilloscope. This probe enables direct diagnostics of the evolution of surface discharge with high temporal resolution and certain spatial resolution. The radiation of a tungsten wire driven by a positive current pulse was measured, and results showed that surface discharge initiates near the cathode and propagates toward the anode with a speed of 7.7 ± 1.6 mm/ns; further estimations showed that this process is responsible for the "conical" structure of the exploding wire.

InGaAs/InP quantum wires grown on silicon with adjustable emission wavelength at telecom bands

NASA Astrophysics Data System (ADS)

Han, Yu; Li, Qiang; Ng, Kar Wei; Zhu, Si; Lau, Kei May

2018-06-01

We report the growth of vertically stacked InGaAs/InP quantum wires on (001) Si substrates with adjustable room-temperature emission at telecom bands. Based on a self-limiting growth mode in selective area metal–organic chemical vapor deposition, crescent-shaped InGaAs quantum wires with variable dimensions are embedded within InP nano-ridges. With extensive transmission electron microscopy studies, the growth transition and morphology change from quantum wires to ridge quantum wells (QWs) have been revealed. As a result, we are able to decouple the quantum wires from ridge QWs and manipulate their dimensions by scaling the growth time. With minimized lateral dimension and their unique positioning, the InGaAs/InP quantum wires are more immune to dislocations and more efficient in radiative processes, as evidenced by their excellent optical quality at telecom-bands. These promising results thus highlight the potential of combining low-dimensional quantum wire structures with the aspect ratio trapping process for integrating III–V nano-light emitters on mainstream (001) Si substrates.

Using of fiber-array diagnostic to measure the propagation of fast axial ionization wave during breakdown of electrically exploding tungsten wire in vacuum

NASA Astrophysics Data System (ADS)

Shi, Huantong; Zou, Xiaobing; Wang, Xinxin

2017-12-01

The physical process of electrical explosion of wires in vacuum is featured with the surface discharge along the wire, which generates the corona plasma layer and terminates the Joule heating of the wire core. In this paper, a fiber-array probe was designed to directly measure the radiation of surface arc with spatial and temporal resolution. The radiation of the exploding wire was casted to the section of an optical-fiber-array by a lens and transmitted to PIN diodes and finally collected with an oscilloscope. This probe enables direct diagnostics of the evolution of surface discharge with high temporal resolution and certain spatial resolution. The radiation of a tungsten wire driven by a positive current pulse was measured, and results showed that surface discharge initiates near the cathode and propagates toward the anode with a speed of 7.7 ± 1.6 mm/ns; further estimations showed that this process is responsible for the "conical" structure of the exploding wire.

Development of practical high temperature superconducting wire for electric power application

NASA Technical Reports Server (NTRS)

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.

InGaAs/InP quantum wires grown on silicon with adjustable emission wavelength at telecom bands.

PubMed

Han, Yu; Li, Qiang; Ng, Kar Wei; Zhu, Si; Lau, Kei May

2018-06-01

We report the growth of vertically stacked InGaAs/InP quantum wires on (001) Si substrates with adjustable room-temperature emission at telecom bands. Based on a self-limiting growth mode in selective area metal-organic chemical vapor deposition, crescent-shaped InGaAs quantum wires with variable dimensions are embedded within InP nano-ridges. With extensive transmission electron microscopy studies, the growth transition and morphology change from quantum wires to ridge quantum wells (QWs) have been revealed. As a result, we are able to decouple the quantum wires from ridge QWs and manipulate their dimensions by scaling the growth time. With minimized lateral dimension and their unique positioning, the InGaAs/InP quantum wires are more immune to dislocations and more efficient in radiative processes, as evidenced by their excellent optical quality at telecom-bands. These promising results thus highlight the potential of combining low-dimensional quantum wire structures with the aspect ratio trapping process for integrating III-V nano-light emitters on mainstream (001) Si substrates.

Solution of magnetohydrodynamic flow and heat transfer of radiative viscoelastic fluid with temperature dependent viscosity in wire coating analysis

PubMed Central

Khan, Muhammad Altaf; Siddiqui, Nasir; Ullah, Murad; Shah, Qayyum

2018-01-01

Wire coating process is a continuous extrusion process for primary insulation of conducting wires with molten polymers for mechanical strength and protection in aggressive environments. In the present study, radiative melt polymer satisfying third grade fluid model is used for wire coating process. The effect of magnetic parameter, thermal radiation parameter and temperature dependent viscosity on wire coating analysis has been investigated. Reynolds model and Vogel’s models have been incorporated for variable viscosity. The governing equations characterizing the flow and heat transfer phenomena are solved analytically by utilizing homotopy analysis method (HAM). The computed results are also verified by ND-Solve method (Numerical technique) and Adomian Decomposition Method (ADM). The effect of pertinent parameters is shown graphically. In addition, the instability of the flow in the flows of the wall of the extrusion die is well marked in the case of the Vogel model as pointed by Nhan-Phan-Thien. PMID:29596448

Cryogenic deformation of high temperature superconductive composite structures

DOEpatents

Roberts, Peter R.; Michels, William; Bingert, John F.

2001-01-01

An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

Blast Coating of Superelastic NiTi Wire with PTFE to Enhance Wear Properties

NASA Astrophysics Data System (ADS)

Dunne, Conor F.; Roche, Kevin; Twomey, Barry; Hodgson, Darel; Stanton, Kenneth T.

2015-03-01

This work investigates the deposition of polytetrafluoroethylene (PTFE) onto a superelastic NiTi wire using an ambient temperature-coating technique known as CoBlast. The process utilises a stream of abrasive (Al2O3) and a coating medium (PTFE) sprayed simultaneously at the surface of the substrate. Superelastic NiTi wire is used in guidewire applications, and PTFE coatings are commonly applied to reduce damage to vessel walls during insertion and removal, and to aid in accurate positioning by minimising the force required to advance, retract or rotate the wire. The CoBlast coated wires were compared to wire treated with PTFE only. The coated samples were examined using variety of techniques: X-ray diffraction (XRD), microscopy, surface roughness, wear testing and flexural tests. The CoBlast coated samples had an adherent coating with a significant resistance to wear compared to the samples coated with PTFE only. The XRD revealed that the process gave rise to a stress-induced martensite phase in the NiTi which may enhance mechanical properties. The study indicates that the CoBlast process can be used to deposit thin adherent coatings of PTFE onto the surface of superelastic NiTi.

Evaluation of Young’s modulus of MgB2 filaments in composite wires for the superconducting links for the high-luminosity LHC upgrade

NASA Astrophysics Data System (ADS)

Sugano, Michinaka; Ballarino, Amalia; Bartova, Barbora; Bjoerstad, Roger; Gerardin, Alexandre; Scheuerlein, Christian

2016-02-01

MgB2 wire is a promising superconductor for the superconducting links for the high-luminosity upgrade of the large Hadron collider at CERN. The mechanical properties of MgB2 must be fully quantified for the cable design, and in this study, we evaluate the Young’s modulus of MgB2 filaments in wires with a practical level of critical current. The Young’s moduli of MgB2 filaments by two different processes, in situ and ex situ, were compared. Two different evaluation methods were applied to an in situ MgB2 wire, a single-fiber tensile test and a tensile test after removing Monel. In addition, the Young’s modulus of the few-micron-thick Nb-Ni reaction layer in an ex situ processed wire was evaluated using a nanoindentation testing technique to improve the accuracy of analysis based on the rule of mixtures. The Young’s moduli of the in situ and ex situ MgB2 wires were in the range of 76-97 GPa and no distinct difference depending on the fabrication process was found.

PROCESSING OF HIGH-PERFORMANCE Nb{sub 3}Sn WIRES THROUGH A NEW DIFFUSION REACTION USING Sn BASED ALLOYS

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

Tachikawa, K.; Sasaki, H.; Yamaguchi, M.

Tightly consolidated Sn-Ta and Sn-B based alloys have been prepared by the reaction among constituent metal powders at 750-775 deg. C. Sn-Ta and Sn-B based alloys exhibit quite similar microstructures. A small amount of Ti addition seems to improve the bonding between Ta or B particles and Sn matrix. Nb{sub 3}Sn wires have been fabricated by the Jelly Roll (JR) and Multi-rod (MR) process using Sn based alloy sheet and rod, respectively. Thick Nb{sub 3}Sn layers with nearly stoichiometric A15 composition are synthesized through a new diffusion mechanism between Nb and Sn based alloy. B{sub c2}(4.2 K)'s of 26.9 Tmore » (mid) and 26.5 T (mid) have been obtained in the JR and MR processed wires, respectively, using Sn-Ta based alloy. These wires exhibit enough non-Cu J{sub c} to be used above 20 T and 4.2 K. T{sub c} of JR wires using Sn-B based sheet is 18.14 K (offset) which is slightly higher than that of wires using Sn-Ta based sheet.« less

Strengthening of Aluminum Wires Treated with A206/Alumina Nanocomposites.

PubMed

Florián-Algarín, David; Marrero, Raúl; Li, Xiaochun; Choi, Hongseok; Suárez, Oscar Marcelo

2018-03-10

This study sought to characterize aluminum nanocomposite wires that were fabricated through a cold-rolling process, having potential applications in TIG (tungsten inert gas) welding of aluminum. A206 (Al-4.5Cu-0.25Mg) master nanocomposites with 5 wt % γAl₂O₃ nanoparticles were first manufactured through a hybrid process combining semi-solid mixing and ultrasonic processing. A206/1 wt % γAl₂O₃ nanocomposites were fabricated by diluting the prepared master nanocomposites with a monolithic A206 alloy, which was then added to a pure aluminum melt. The fabricated Al-γAl₂O₃ nanocomposite billet was cold-rolled to produce an Al nanocomposite wire with a 1 mm diameter and a transverse area reduction of 96%. Containing different levels of nanocomposites, the fabricated samples were mechanically and electrically characterized. The results demonstrate a significantly higher strength of the aluminum wires with the nanocomposite addition. Further, the addition of alumina nanoparticles affected the wires' electrical conductivity compared with that of pure aluminum and aluminum-copper alloys. The overall properties of the new material demonstrate that these wires could be an appealing alternative for fillers intended for aluminum welding.

The Effect of Condensate Inundation on Steam Condensation Heat Transfer in a Tube Bundle.

DTIC Science & Technology

1985-06-01

predicted by Nusselt [Ref. 10] were measured. This increase was attributed to the effect of surface tension drawing the condensate to the wire and acting...analysis of film condensation on a horizontal tube was set forth by Nusselt in 1916. His analy- sis was, however, for laminar film condensation on a single...temperature. Jakob [Ref. 17] extended the Nusselt analysis to film condensation on a vertical in-line column of horizontal tubes by assuming that all

System design and installation for RS600 programmable control system for solar heating and cooling

NASA Technical Reports Server (NTRS)

1978-01-01

Procedures for installing, operating, and maintaining a programmable control system which utilizes a F8 microprocessor to perform all timing, control, and calculation functions in order to customize system performance to meet individual requirements for solar heating, combined heating and cooling, and/or hot water systems are described. The manual discusses user configuration and options, displays, theory of operation, trouble-shooting procedures, and warranty and assistance. Wiring lists, parts lists, drawings, and diagrams are included.

Structural Response of the Slotted Waveguide Antenna Stiffened Structure Components Under Compression

DTIC Science & Technology

2010-03-01

mounted in its center point. One can see the 62 Figure 45 Shear Specimen Drawing for ASTM Test D7078 wire lead pads coming from the gage in the ±45...wall is much stronger without the slots cut in it. This inward buckling motion tilts the three slots towards inward bulging and this crumpling of the...Structural Composites with Piezoelectric Micro-Constituents. Tech. rep., U.S. Army Research Office. 15. Thomas, J., Qidwai, M., Baucom, J., and Pogue, W

Physical and mechanical properties of a thermomechanically treated NiTi wire used in the manufacture of rotary endodontic instruments.

PubMed

Pereira, E S J; Peixoto, I F C; Viana, A C D; Oliveira, I I; Gonzalez, B M; Buono, V T L; Bahia, M G A

2012-05-01

To compare physical and mechanical properties of one conventional and one thermomechanically treated nickel-titanium (NiTi) wire used to manufacture rotary endodontic instruments. Two NiTi wires 1.0 mm in diameter were characterized; one of them, C-wire (CW), was processed in the conventional manner, and the other, termed M-Wire (MW), received an additional heat treatment according to the manufacturer. Chemical composition was determined by energy-dispersive X-ray spectroscopy, phase constitution by XRD and the transformation temperatures by DSC. Tensile loading/unloading tests and Vickers microhardness measurements were performed to assess the mechanical behaviour. Data were analysed using analysis of variance (α = 0.05). The two wires showed approximately the same chemical composition, close to the 1 : 1 atomic ratio, and the β-phase was the predominant phase present. B19' martensite and the R-phase were found in MW, in agreement with the higher transformation temperatures found in this wire compared with CW, whose transformation temperatures were below room temperature. Average Vickers microhardness values were similar for MW and CW (P = 0.91). The stress at the transformation plateau in the tensile load-unload curves was lower and more uniform in the M-Wire, which also showed the smallest stress hysteresis and apparent elastic modulus. The M-Wire had physical and mechanical properties that can render endodontic instruments more flexible and fatigue resistant than those made with conventionally processed NiTi wires. © 2011 International Endodontic Journal.

Line drawing of Apollo 14 Command/Service Modules

NASA Image and Video Library

1971-01-12

S71-16823 (January 1971) --- A line drawing illustrating a cutaway view of the Apollo 14 Command and Service Modules, showing the engineering changes in the CSM which were recommended by the Apollo 13 Review Board. (The Apollo 13 abort was caused by a short circuit and wiring overheating in one of the SM cryogenic oxygen tanks.) The major changes to the Apollo 14 CSM include adding a third cryogenic oxygen tank installed in a heretofore empty bay (in sector one) of the SM, addition of an auxiliary battery in the SM as a backup in case of fuel cell failure, and removal of destratification fans in the cryogenic oxygen tanks and removal of thermostat switches from the oxygen tank heater circuits. Provision for stowage of an emergency five-gallon supply of drinking water has been added to the CM.

Quench degradation limit of multifilamentary AgBi 2Sr 2CaCu 2O x round wires

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

Ye, Liyang; Li, Pei; Shen, Tengming

Understanding safe operating limits of composite superconducting wires is important for the design of superconducting magnets. Here we report measurements of quench-induced critical current density Jc degradation in commercial Ag/Bi 2Sr 2CaCu 2O x (Bi-2212) round wires using heater-induced quenches at 4.2 K in self magnetic field that reveal a general degradation behavior. J c degradation strongly depends on the local hot spot temperature T max, and is nearly independent of operating current, the temperature gradient along the conductor dT max/dx, and the temperature rising rate dT max/dt. Both J c and n value (where n is an index ofmore » the sharpness of the superconductor-to-normal transition) exhibit small but irreversible degradation when T max exceeds 400-450 K, and large degradation occurs when Tmax exceeds 550 K. This behavior was consistently found for a series of Bi-2212 wires with widely variable wire architectures and porosity levels in the Bi-2212 filaments, including a wire processed using a standard partial melt processing and in which Bi-2212 filaments are porous, an overpressure processed wire in which Bi-2212 filaments are nearly porosity-free and that has a J c(4.2 K, self field) exceeding 8000 A/mm 2, and a wire that has nearly no filament to filament bridges after reaction. Microstructural observations of degraded wires reveal cracks in the Bi-2212 filaments perpendicular to the wire axis, indicating that the quench-induced I c degradation is primarily driven by strain. These results further suggest that the quench degradation temperature limit depends on the strain state of Bi-2212 filaments and this dependence shall be carefully considered when engineering a high-field Bi-2212 magnet.« less

Quench degradation limit of multifilamentary AgBi 2Sr 2CaCu 2O x round wires

DOE PAGES

Ye, Liyang; Li, Pei; Shen, Tengming; ...

2016-02-02

Understanding safe operating limits of composite superconducting wires is important for the design of superconducting magnets. Here we report measurements of quench-induced critical current density Jc degradation in commercial Ag/Bi 2Sr 2CaCu 2O x (Bi-2212) round wires using heater-induced quenches at 4.2 K in self magnetic field that reveal a general degradation behavior. J c degradation strongly depends on the local hot spot temperature T max, and is nearly independent of operating current, the temperature gradient along the conductor dT max/dx, and the temperature rising rate dT max/dt. Both J c and n value (where n is an index ofmore » the sharpness of the superconductor-to-normal transition) exhibit small but irreversible degradation when T max exceeds 400-450 K, and large degradation occurs when Tmax exceeds 550 K. This behavior was consistently found for a series of Bi-2212 wires with widely variable wire architectures and porosity levels in the Bi-2212 filaments, including a wire processed using a standard partial melt processing and in which Bi-2212 filaments are porous, an overpressure processed wire in which Bi-2212 filaments are nearly porosity-free and that has a J c(4.2 K, self field) exceeding 8000 A/mm 2, and a wire that has nearly no filament to filament bridges after reaction. Microstructural observations of degraded wires reveal cracks in the Bi-2212 filaments perpendicular to the wire axis, indicating that the quench-induced I c degradation is primarily driven by strain. These results further suggest that the quench degradation temperature limit depends on the strain state of Bi-2212 filaments and this dependence shall be carefully considered when engineering a high-field Bi-2212 magnet.« less

Understanding the densification process of Bi2Sr2CaCu2O x round wires with overpressure processing and its effect on critical current density

NASA Astrophysics Data System (ADS)

Matras, M. R.; Jiang, J.; Larbalestier, D. C.; Hellstrom, E. E.

2016-10-01

Overpressure (OP) processing increases the critical current density ({{\\boldsymbol{J}}}{{C}}) of Bi2Sr2CaCu2O x (2212) round wires by shrinking the surrounding Ag matrix around the 2212 filaments, driving them close to full density and greatly increasing the 2212 grain connectivity. Indeed densification is vital for attaining the highest {{\\boldsymbol{J}}}{{C}}. Here, we investigate the time and temperature dependence of the wire densification. We find that the wire diameter decreases by 3.8 ± 0.3% after full heat treatment at 50 atm and 100 atm OP. At 50 atm OP pressure, the filaments start densifying above 700 °C and reach a 3.30 ± 0.07% smaller diameter after 2 h at 820 °C, which is below the melting point of 2212 powder. The densification is homogeneous and does not change the filament shape before melting. The growth of non-superconducting phases is observed at 820 °C, suggesting that time should be minimized at high temperature prior to melting the 2212 powder. Study of an open-ended 2.2 m long wire sample shows that full densification and the high OP {{\\boldsymbol{J}}}{{C}} ({{\\boldsymbol{J}}}{{C}} varies by about 3.1 times over the 2.2 m long wire) is reached about 1 m from the open ends, thus showing that coil-length wires can be protected from leaky seals by adding at least 1 m of sacrificial wire at each end.

Next Generation Wiring

NASA Technical Reports Server (NTRS)

Medelius, Petro; Jolley, Scott; Fitzpatrick, Lilliana; Vinje, Rubiela; Williams, Martha; Clayton, LaNetra; Roberson, Luke; Smith, Trent; Santiago-Maldonado, Edgardo

2007-01-01

Wiring is a major operational component on aerospace hardware that accounts for substantial weight and volumetric space. Over time wire insulation can age and fail, often leading to catastrophic events such as system failure or fire. The next generation of wiring must be reliable and sustainable over long periods of time. These features will be achieved by the development of a wire insulation capable of autonomous self-healing that mitigates failure before it reaches a catastrophic level. In order to develop a self-healing insulation material, three steps must occur. First, methods of bonding similar materials must be developed that are capable of being initiated autonomously. This process will lead to the development of a manual repair system for polyimide wire insulation. Second, ways to initiate these bonding methods that lead to materials that are similar to the primary insulation must be developed. Finally, steps one and two must be integrated to produce a material that has no residues from the process that degrades the insulating properties of the final repaired insulation. The self-healing technology, teamed with the ability to identify and locate damage, will greatly improve reliability and safety of electrical wiring of critical systems. This paper will address these topics, discuss the results of preliminary testing, and remaining development issues related to self-healing wire insulation.

Selection of Wire Electrical Discharge Machining Process Parameters on Stainless Steel AISI Grade-304 using Design of Experiments Approach

NASA Astrophysics Data System (ADS)

Lingadurai, K.; Nagasivamuni, B.; Muthu Kamatchi, M.; Palavesam, J.

2012-06-01

Wire electrical discharge machining (WEDM) is a specialized thermal machining process capable of accurately machining parts of hard materials with complex shapes. Parts having sharp edges that pose difficulties to be machined by the main stream machining processes can be easily machined by WEDM process. Design of Experiments approach (DOE) has been reported in this work for stainless steel AISI grade-304 which is used in cryogenic vessels, evaporators, hospital surgical equipment, marine equipment, fasteners, nuclear vessels, feed water tubing, valves, refrigeration equipment, etc., is machined by WEDM with brass wire electrode. The DOE method is used to formulate the experimental layout, to analyze the effect of each parameter on the machining characteristics, and to predict the optimal choice for each WEDM parameter such as voltage, pulse ON, pulse OFF and wire feed. It is found that these parameters have a significant influence on machining characteristic such as metal removal rate (MRR), kerf width and surface roughness (SR). The analysis of the DOE reveals that, in general the pulse ON time significantly affects the kerf width and the wire feed rate affects SR, while, the input voltage mainly affects the MRR.

Real-time monitoring of the laser hot-wire welding process

NASA Astrophysics Data System (ADS)

Liu, Wei; Liu, Shuang; Ma, Junjie; Kovacevic, Radovan

2014-04-01

The laser hot-wire welding process was investigated in this work. The dynamics of the molten pool during welding was visualized by using a high-speed charge-coupled device (CCD) camera assisted by a green laser as an illumination source. It was found that the molten pool is formed by the irradiation of the laser beam on the filler wire. The effect of the hot-wire voltage on the stability of the welding process was monitored by using a spectrometer that captured the emission spectrum of the laser-induced plasma plume. The spectroscopic study showed that when the hot-wire voltage is above 9 V a great deal of spatters occur, resulting in the instability of the plasma plume and the welding process. The effect of spatters on the plasma plume was shown by the identified spectral lines of the element Mn I. The correlation between the Fe I electron temperature and the weld-bead shape was studied. It was noted that the electron temperature of the plasma plume can be used to real-time monitor the variation of the weld-bead features and the formation of the weld defects.

Kinetic analysis of MgB2 layer formation in advanced internal magnesium infiltration (AIMI) processed MgB2 wires

PubMed Central

Li, G. Z.; Sumption, M. D.; Collings, E. W.

2015-01-01

Significantly enhanced critical current density (Jc) for MgB2 superconducting wires can be obtained following the advanced internal Mg infiltration (AIMI) route. But unless suitable precautions are taken, the AIMI-processed MgB2 wires will exhibit incomplete MgB2 layer formation, i.e. reduced superconductor core size and hence suppressed current-carrying capability. Microstructural characterization of AIMI MgB2 wires before and after the heat treatment reveals that the reaction mechanism changes from a “Mg infiltration-reaction” at the beginning of the heat treatment to a “Mg diffusion-reaction” once a dense MgB2 layer is formed. A drastic drop in the Mg transport rate from infiltration to diffusion causes the termination of the MgB2 core growth. To quantify this process, a two-stage kinetic model is built to describe the MgB2 layer formation and growth. The derived kinetic model and the associated experimental observations indicate that fully reacted AIMI-processed MgB2 wires can be achieved following the optimization of B particle size, B powder packing density, MgB2 reaction activation energy and its response to the additions of dopants. PMID:26973431

Thin wire pointing method

NASA Technical Reports Server (NTRS)

Green, G.; Mattauch, R. J. (Inventor)

1983-01-01

A method is described for forming sharp tips on thin wires, in particular phosphor bronze wires of diameters such as one-thousandth inch used to contact micron size Schottky barrier diodes, which enables close control of tip shape and which avoids the use of highly toxic solutions. The method includes dipping an end of a phosphor bronze wire into a dilute solution of sulfamic acid and applying a current through the wire to electrochemically etch it. The humidity in the room is controlled to a level of less than 50%, and the voltage applied between the wire and another electrode in the solutions is a half wave rectified voltage. The current through the wire is monitored, and the process is stopped when the current falls to a predetermined low level.

Failure analysis of the fractured wires in sternal perichronal loops.

PubMed

Chao, Jesús; Voces, Roberto; Peña, Carmen

2011-10-01

We report failure analysis of sternal wires in two cases in which a perichronal fixation technique was used to close the sternotomy. Various characteristics of the retrieved wires were compared to those of unused wires of the same grade and same manufacturer and with surgical wire specifications. In both cases, wire fracture was un-branched and transgranular and proceeded by a high cycle fatigue process, apparently in the absence of corrosion. However, stress anlysis indicates that the effective stress produced during strong coughing is lower than the yield strength. Our findings suggest that in order to reduce the risk for sternal dehiscence, the diameter of the wire used should be increased. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

Sudhakara, Dara; Prasanthi, Guvvala

2017-04-01

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.

Choice of mathematical models for technological process of glass rod drawing

NASA Astrophysics Data System (ADS)

Alekseeva, L. B.

2017-10-01

The technological process of drawing glass rods (light guides) is considered. Automated control of the drawing process is reduced to the process of making decisions to ensure a given quality. The drawing process is considered as a control object, including the drawing device (control device) and the optical fiber forming zone (control object). To study the processes occurring in the formation zone, mathematical models are proposed, based on the continuum mechanics basics. To assess the influence of disturbances, a transfer function is obtained from the basis of the wave equation. Obtaining the regression equation also adequately describes the drawing process.

Method for controlling gas metal arc welding

DOEpatents

Smartt, Herschel B.; Einerson, Carolyn J.; Watkins, Arthur D.

1989-01-01

The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

22 CFR 122.2 - Submission of registration statement.

Code of Federal Regulations, 2013 CFR

2013-04-01

... payment via Automated Clearing House or Federal Reserve Wire Network payable to the Department of State of... Federal Reserve Wire Network (FedWire) are electronic networks used to process financial transactions in...., Comptroller, Treasurer, General Counsel) or any member of the board of directors: (i) Has ever been indicted...

22 CFR 122.2 - Submission of registration statement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... payment via Automated Clearing House or Federal Reserve Wire Network payable to the Department of State of... Federal Reserve Wire Network (FedWire) are electronic networks used to process financial transactions in...., Comptroller, Treasurer, General Counsel) or any member of the board of directors: (i) Has ever been indicted...

Processing and Characterization of Liquid-Phase Sintered NiTi Woven Structures

NASA Astrophysics Data System (ADS)

Erdeniz, Dinc; Weidinger, Ryan P.; Sharp, Keith W.; Dunand, David C.

2018-03-01

Porous NiTi is of interest for bone implants because of its unique combination of biocompatibility (encouraging osseointegration), high strength (to prevent fracture), low stiffness (to reduce stress shielding), and shape memory or superelasticity (to deploy an implant). A promising method for creating NiTi structures with regular open channels is via 3D weaving of NiTi wires. This paper presents a processing method to bond woven NiTi wire structures at contact points between wires to achieve structural integrity: (i) a slurry consisting of a blend of NiTi and Nb powders is deposited on the surface of the NiTi wires after the weaving operation; (ii) the powders are melted to create a eutectic liquid phase which collects at contact points; and (iii) the liquid is solidified and binds the NiTi woven structures. The bonded NiTi wire structures exhibited lower transformation temperatures compared to the as-woven NiTi wires because of Nb diffusion into the NiTi wires. A bonded woven sample was deformed in bending and showed near-complete recovery up to 6% strain and recovered nearly half of the deformation up to 19% strain.

Update on High-Temperature Coils for Electromagnets

NASA Technical Reports Server (NTRS)

Kascak, Albert F.; Montague, Gerald T.; Palazzolo, Alan; Preuss, Jason; Carter, Bart; Tucker, Randall; Hunt, Andrew

2005-01-01

A report revisits the subject matter of "High-Temperature Coils for Electromagnets" (LEW-17164), NASA Tech Briefs, Vol. 26, No. 8, (August 2002) page 38. To recapitulate: Wires have been developed for use in electromagnets that operate at high temperatures. The starting material for a wire of this type can be either a nickel-clad, ceramic-insulated copper wire or a bare silver wire. The wire is covered by electrical-insulation material that is intended to withstand operating temperatures in the range from 800 to 1,300 F (.430 to .700 C): The starting wire is either primarily wrapped with S-glass as an insulating material or else covered with another insulating material wrapped in S-glass prior to the winding process. A ceramic binding agent is applied as a slurry during the winding process to provide further insulating capability. The turns are pre-bent during winding to prevent damage to the insulation. The coil is then heated to convert the binder into ceramic. The instant report mostly reiterates the prior information and presents some additional information on the application of the ceramic binding agent and the incorporation of high-temperature wire into the windings.

Edge Modes and Teleportation in a Topologically Insulating Quantum Wire

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

Ghrear, Majd; Mackovic, Brie; Semenoff, Gordon W.

We find a simple model of an insulating state of a quantum wire which has a single isolated edge mode. We argue that, when brought to proximity, the edge modes on independent wires naturally form Bell entangled states which could be used for elementary quantum processes such as teleportation. We give an example of an algorithm which teleports the spin state of an electron from one quantum wire to another.

The effects of insulating coatings and current prepulse on tungsten planar wire array Z-pinches

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

Li, M., E-mail: limo@nint.ac.cn; Li, Y.; State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Xi'an 710024

2015-12-15

This paper presents experimental results on the effects of insulating coatings and current prepulse on tungsten planar wire array Z-pinches on ∼100 ns main current facility. Optical framing images indicated that without a current prepulse the wire ablation process was asymmetrical and the implosion was zippered. The x-ray peak power was ∼320 GW. By using insulating coatings on the wire surface the asymmetry remained, and the processes of ablation and implosion were delayed by ∼30 ns. The x-ray burst was narrow and decreased to ∼200 GW. When current prepulses were used on both standard and insulated wire arrays, implosion symmetry was improved and themore » x-ray burst was improved (to ∼520 GW peak power). In addition, there was a strong emitting precursor column for insulated loads with the current prepulse.« less

Experimental and numerical investigations of wire bending by linear winding of rectangular tooth coils

NASA Astrophysics Data System (ADS)

Komodromos, A.; Tekkaya, A. E.; Hofmann, J.; Fleischer, J.

2018-05-01

Since electric motors are gaining in importance in many fields of application, e.g. hybrid electric vehicles, optimization of the linear coil winding process greatly contributes to an increase in productivity and flexibility. For the investigation of the forming behavior of the winding wire the material behavior is characterized in different experimental setups. Numerical examinatons of the linear winding process are carried out in a case study for a rectangular bobbin in order to analyze the influence of forming parameters on the resulting properties of the wound coil. Besides the numerical investigation of the linear winding method by using the finite element method (FEM), a multi-body dynamics (MBD) simulation is carried out. The multi-body dynamics simulation is necessary to represent the movement of the bodies as well as the connection of the components during winding. The finite element method is used to represent the material behavior of the copper wire and the plastic strain distribution within the wire. It becomes clear that the MBD simulation is not sufficient for analyzing the process and the wire behavior in its entirety. Important parameters that define the final coil properties cannot be analyzed in the manner of a precise manifestation, e.g. the clearance between coil bobbin and wire as well as the wire deformation behavior in form of a diameter reduction which negatively affects the ohmic resistance. Finally, the numerical investigations are validated experimentally by linear winding tests.

Increasing component functionality via multi-process additive manufacturing

NASA Astrophysics Data System (ADS)

Coronel, Jose L.; Fehr, Katherine H.; Kelly, Dominic D.; Espalin, David; Wicker, Ryan B.

2017-05-01

Additively manufactured components, although extensively customizable, are often limited in functionality. Multi-process additive manufacturing (AM) grants the ability to increase the functionality of components via subtractive manufacturing, wire embedding, foil embedding and pick and place. These processes are scalable to include several platforms ranging from desktop to large area printers. The Multi3D System is highlighted, possessing the capability to perform the above mentioned processes, all while transferring a fabricated component with a robotic arm. Work was conducted to fabricate a patent inspired, printed missile seeker. The seeker demonstrated the advantage of multi-process AM via introduction of the pick and place process. Wire embedding was also explored, with the successful interconnect of two layers of embedded wires in different planes. A final demonstration of a printed contour bracket, served to show the reduction of surface roughness on a printed part is 87.5% when subtractive manufacturing is implemented in tandem with AM. Functionality of the components on all the cases was improved. Results included optical components embedded within the printed housing, wires embedded with interconnection, and reduced surface roughness. These results highlight the improved functionality of components through multi-process AM, specifically through work conducted with the Multi3D System.

Novel Chemical Process for Producing Chrome Coated Metal

PubMed Central

Pelar, Christopher; Greenaway, Karima; Zea, Hugo; Wu, Chun-Hsien

2018-01-01

This work demonstrates that a version of the Reduction Expansion Synthesis (RES) process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 °C for 10 min in a tube furnace under a slow flow of nitrogen gas. The processed wires were then polished and characterized, primarily with scanning electron microscopy (SEM). SEM indicates the chrome layer is uneven, but only on the scale of a fraction of a micron. The evidence of porosity is ambiguous. Elemental mapping using SEM electron microprobe that confirmed the process led to the formation of a chrome metal layer, with no evidence of alloy formation. Additionally, it was found that thickness of the final Cr layer correlated with the thickness of the precursor layer that was applied prior to the heating step. Potentially, this technique could replace electrolytic processing, a process that generates carcinogenic hexavalent chrome, but further study and development is needed. PMID:29303977

Novel Chemical Process for Producing Chrome Coated Metal.

PubMed

Pelar, Christopher; Greenaway, Karima; Zea, Hugo; Wu, Chun-Hsien; Luhrs, Claudia C; Phillips, Jonathan

2018-01-05

This work demonstrates that a version of the Reduction Expansion Synthesis (RES) process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 °C for 10 min in a tube furnace under a slow flow of nitrogen gas. The processed wires were then polished and characterized, primarily with scanning electron microscopy (SEM). SEM indicates the chrome layer is uneven, but only on the scale of a fraction of a micron. The evidence of porosity is ambiguous. Elemental mapping using SEM electron microprobe that confirmed the process led to the formation of a chrome metal layer, with no evidence of alloy formation. Additionally, it was found that thickness of the final Cr layer correlated with the thickness of the precursor layer that was applied prior to the heating step. Potentially, this technique could replace electrolytic processing, a process that generates carcinogenic hexavalent chrome, but further study and development is needed.

Bending effects and temperature dependence of magnetic properties in a Fe-rich amorphous wire

NASA Astrophysics Data System (ADS)

Bordin, G.; Buttino, G.; Poppi, M.

2001-08-01

Amorphous wires with composition Fe 77.5Si 7.5B 15 exhibit a very peculiar magnetization process characterized by a single and quite large Barkhausen jump. This gives rise to a squared hysteresis loop at a critical magnetic field. The bistable behaviour, widely studied in wires with typical length of 10 cm and diameter of 125 μm, appears above a length of about 7 cm in straight wires and disappears for curvature radius within the range 2-12 cm in bent wires. In this work it is shown that bistability occurs in bent wires, whatever their curvature is, provided the wires are long enough. To this purpose spiral-shaped samples with several turns are considered. However, when the wire length is not a integer number of turns the magnetization reverses through many large Barkhausen jumps. In this condition, varying the measuring temperature can activate the energy barriers for the jumps.

Autonomous diagnostics and prognostics of signal and data distribution systems

NASA Astrophysics Data System (ADS)

Blemel, Kenneth G.

2001-07-01

Wiring is the nervous system of any complex system and is attached to or services nearly every subsystem. Damage to optical wiring systems can cause serious interruptions in communication, command and control systems. Electrical wiring faults and failures due to opens, shorts, and arcing probably result in adverse effects to the systems serviced by the wiring. Abnormalities in a system usually can be detected by monitoring some wiring parameter such as vibration, data activity or power consumption. This paper introduces the mapping of wiring to critical functions during system engineering to automatically define the Failure Modes Effects and Criticality Analysis. This mapping can be used to define the sensory processes needed to perform diagnostics during system engineering. This paper also explains the use of Operational Modes and Criticality Effects Analysis in the development of Sentient Wiring Systems as a means for diagnostic, prognostics and health management of wiring in aerospace and transportation systems.

Wire Crimp Connectors Verification using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2007-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp connections is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp connector and wire is shown to correlate with the results of a destructive pull test, which previously has been used to assess crimp wire junction quality. Various crimp junction pathologies (missing wire strands, incorrect wire gauge, incomplete wire insertion in connector) are ultrasonically tested, and their results are correlated with pull tests. Results show that the ultrasonic measurement technique consistently (as evidenced with pull-testing data) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying the technique while wire crimps are installed is also presented.

Polymer Chemistry

NASA Technical Reports Server (NTRS)

Williams, Martha; Roberson, Luke; Caraccio, Anne

2010-01-01

This viewgraph presentation describes new technologies in polymer and material chemistry that benefits NASA programs and missions. The topics include: 1) What are Polymers?; 2) History of Polymer Chemistry; 3) Composites/Materials Development at KSC; 4) Why Wiring; 5) Next Generation Wiring Materials; 6) Wire System Materials and Integration; 7) Self-Healing Wire Repair; 8) Smart Wiring Summary; 9) Fire and Polymers; 10) Aerogel Technology; 11) Aerogel Composites; 12) Aerogels for Oil Remediation; 13) KSC's Solution; 14) Chemochromic Hydrogen Sensors; 15) STS-130 and 131 Operations; 16) HyperPigment; 17) Antimicrobial Materials; 18) Conductive Inks Formulations for Multiple Applications; and 19) Testing and Processing Equipment.

Extrusion of metal oxide superconducting wire, tube or ribbon

DOEpatents

Dusek, Joseph T.

1993-10-05

A process for extruding a superconducting metal oxide composition YBa.sub.2 Cu.sub.3 O.sub.7-x provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6-85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87-355 mil has also been produced. Flat ribbons have been produced in the range of 10-125 mil thick by 100-500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

Extrusion of metal oxide superconducting wire, tube or ribbon

DOEpatents

Dusek, Joseph T.

1993-01-01

A process for extruding a superconducting metal oxide composition YBa.sub.2 Cu.sub.3 O.sub.7-x provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6-85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87-355 mil has also been produced. Flat ribbons have been produced in the range of 10-125 mil thick by 100-500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

A review of wiring system safety in space power systems

NASA Technical Reports Server (NTRS)

Stavnes, Mark W.; Hammoud, Ahmad N.

1993-01-01

Wiring system failures have resulted from arc propagation in the wiring harnesses of current aerospace vehicles. These failures occur when the insulation becomes conductive upon the initiation of an arc. In some cases, the conductive path of the carbon arc track displays a high enough resistance such that the current is limited, and therefore may be difficult to detect using conventional circuit protection. Often, such wiring failures are not simply the result of insulation failure, but are due to a combination of wiring system factors. Inadequate circuit protection, unforgiving system designs, and careless maintenance procedures can contribute to a wiring system failure. This paper approaches the problem with respect to the overall wiring system, in order to determine what steps can be taken to improve the reliability, maintainability, and safety of space power systems. Power system technologies, system designs, and maintenance procedures which have led to past wiring system failures will be discussed. New technologies, design processes, and management techniques which may lead to improved wiring system safety will be introduced.

Ex-situ manufacturing of SiC-doped MgB2 used for superconducting wire in medical device applications

NASA Astrophysics Data System (ADS)

Herbirowo, Satrio; Imaduddin, Agung; Sofyan, Nofrijon; Yuwono, Akhmad Herman

2017-02-01

Magnesium diboride (MgB2) is a superconductor material with a relatively high critical temperature. Due to its relatively high critical temperature, this material is promising and has the potential to replace Nb3Sn for wire superconducting used in many medical devices. In this work, nanoparticle SiC-doped MgB2 superconducting material has been fabricated through an ex-situ method. The doping of nanoparticle SiC by 10 and 15 wt% was conducted to analyze its effect on specific resistivity of MgB2. The experiment was started by weighing a stoichiometric amount of MgB2 and nanoparticles SiC. Both materials were mixed and grounded for 30 minutes by using an agate mortar. The specimens were then pressed into a 6 mm diameter stainless steel tube, which was then reduced until 3 mm through a wire drawing method. X-ray diffraction analysis was conducted to confirm the phase, whereas the superconductivity of the specimens was analyzed by using resistivity measurement under cryogenic magnetic system. The results indicated that the commercial MgB2 showed a critical temperature of 37.5 K whereas the SiC doped MgB2 has critical temperature of 38.3 K.

Load-resistant coaxial transmission line

DOEpatents

Hall, David R.; Fox, Joe

2006-01-03

A transmission line for downhole tools that make up all or part of a tool string for drilling and production of oil, gas, and geothermal wells that can withstand the dynamic gravitational forces and other accelerations associated with downhole excavations. The transmission line has a metal tube, or outer conductor, that houses a coaxial wire inner conductor. A non-metallic dielectric material is interposed between the inner and outer conductors. The outer and inner conductors and the dielectric are sufficiently compressed together so that independent motion between them is abated. Compression of the components of the transmission line may be achieved by drawing the transmission through one or more dies in order to draw down the outer conductor onto the dielectric, or by expanding the inner conductor against the dielectric using a mandrel or hydraulic pressure. Non-metallic bead segments may be used in aid of the compression necessary to resist the dynamic forces and accelerations of drilling.

Geometry characteristics modeling and process optimization in coaxial laser inside wire cladding

NASA Astrophysics Data System (ADS)

Shi, Jianjun; Zhu, Ping; Fu, Geyan; Shi, Shihong

2018-05-01

Coaxial laser inside wire cladding method is very promising as it has a very high efficiency and a consistent interaction between the laser and wire. In this paper, the energy and mass conservation law, and the regression algorithm are used together for establishing the mathematical models to study the relationship between the layer geometry characteristics (width, height and cross section area) and process parameters (laser power, scanning velocity and wire feeding speed). At the selected parameter ranges, the predicted values from the models are compared with the experimental measured results, and there is minor error existing, but they reflect the same regularity. From the models, it is seen the width of the cladding layer is proportional to both the laser power and wire feeding speed, while it firstly increases and then decreases with the increasing of the scanning velocity. The height of the cladding layer is proportional to the scanning velocity and feeding speed and inversely proportional to the laser power. The cross section area increases with the increasing of feeding speed and decreasing of scanning velocity. By using the mathematical models, the geometry characteristics of the cladding layer can be predicted by the known process parameters. Conversely, the process parameters can be calculated by the targeted geometry characteristics. The models are also suitable for multi-layer forming process. By using the optimized process parameters calculated from the models, a 45 mm-high thin-wall part is formed with smooth side surfaces.

Method for controlling gas metal arc welding

DOEpatents

Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

1987-08-10

The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

New concepts and materials for the manufacturing of MR-compatible guide wires.

PubMed

Brecher, Christian; Emonts, Michael; Brack, Alexander; Wasiak, Christian; Schütte, Adrian; Krämer, Nils; Bruhn, Robin

2014-04-01

This paper shows the development of a new magnetic resonance imaging (MRI)-compatible guide wire made from fiber-reinforced plastics. The basic material of the developed guide wire is manufactured using a specially developed micro-pullwinding technology, which allows the adjustment of tensile, bending, and torsional stiffness independent from each other. Additionally, the micro-pullwinding technology provides the possibility to vary the stiffness along the length of the guide wire in a continuous process. With the possibilities of this technology, the mechanical properties of the guide wire were precisely adjusted for the intended usage in MRI-guided interventions. The performance of the guide wire regarding the mechanical properties was investigated. It could be shown, that the mechanical properties could be changed independently from each other by varying the process parameters. Especially, the torsional stiffness could be significantly improved with only a minor influence on bending and tensile properties. The precise influence of the variation of the winding angle on the mechanical and geometrical properties has to be further investigated. The usability of the guide wire as well as its visibility in MRI was investigated by radiologists. With the micro-pullwinding technology, a continuous manufacturing technique for highly stressable, MRI-safe profiles is available and can be the trigger for a new class of medical devices.

Wire-shaped perovskite solar cell based on TiO2 nanotubes

NASA Astrophysics Data System (ADS)

Wang, Xiaoyan; Kulkarni, Sneha A.; Li, Zhen; Xu, Wenjing; Batabyal, Sudip K.; Zhang, Sam; Cao, Anyuan; Wong, Lydia Helena

2016-05-01

In this work, a wire-shaped perovskite solar cell based on TiO2 nanotube (TNT) arrays is demonstrated for the first time by integrating a perovskite absorber on TNT-coated Ti wire. Anodization was adopted for the conformal growth of TNTs on Ti wire, together with the simultaneous formation of a compact TiO2 layer. A sequential step dipping process is employed to produce a uniform and compact perovskite layer on top of TNTs with conformal coverage as the efficient light absorber. Transparent carbon nanotube film is wrapped around Ti wire as the hole collector and counter electrode. The integrated perovskite solar cell wire by facile fabrication approaches shows a promising future in portable and wearable textile electronics.

Welding wire pressure sensor assembly

NASA Technical Reports Server (NTRS)

Morris, Timothy B. (Inventor); Milly, Peter F., Sr. (Inventor); White, J. Kevin (Inventor)

1994-01-01

The present invention relates to a device which is used to monitor the position of a filler wire relative to a base material being welded as the filler wire is added to a welding pool. The device is applicable to automated welding systems wherein nonconsumable electrode arc welding processes are utilized in conjunction with a filler wire which is added to a weld pool created by the electrode arc. The invention senses pressure deviations from a predetermined pressure between the filler wire and the base material, and provides electrical signals responsive to the deviations for actuating control mechanisms in an automatic welding apparatus so as to minimize the pressure deviation and to prevent disengagement of the contact between the filler wire and the base material.

Method and apparatus for diamond wire cutting of metal structures

DOEpatents

Parsells, Robert; Gettelfinger, Geoff; Perry, Erik; Rule, Keith

2005-04-19

A method and apparatus for diamond wire cutting of metal structures, such as nuclear reactor vessels, is provided. A diamond wire saw having a plurality of diamond beads with beveled or chamfered edges is provided for sawing into the walls of the metal structure. The diamond wire is guided by a plurality of support structures allowing for a multitude of different cuts. The diamond wire is cleaned and cooled by CO.sub.2 during the cutting process to prevent breakage of the wire and provide efficient cutting. Concrete can be provided within the metal structure to enhance cutting efficiency and reduce airborne contaminants. The invention can be remotely controlled to reduce exposure of workers to radioactivity and other hazards.

Wire ablation dynamics model and its application to imploding wire arrays of different geometries.

PubMed

Esaulov, A A; Kantsyrev, V L; Safronova, A S; Velikovich, A L; Shrestha, I K; Williamson, K M; Osborne, G C

2012-10-01

The paper presents an extended description of the amplified wire ablation dynamics model (WADM), which accounts in a single simulation for the processes of wire ablation and implosion of a wire array load of arbitrary geometry and wire material composition. To investigate the role of wire ablation effects, the implosions of cylindrical and planar wire array loads at the university based generators Cobra (Cornell University) and Zebra (University of Nevada, Reno) have been analyzed. The analysis of the experimental data shows that the wire mass ablation rate can be described as a function of the current through the wire and some coefficient defined by the wire material properties. The aluminum wires were found to ablate with the highest rate, while the copper ablation is the slowest one. The lower wire ablation rate results in a higher inward velocity of the ablated plasma, a higher rate of the energy coupling with the ablated plasma, and a more significant delay of implosion for a heavy load due to the ablation effects, which manifest the most in a cylindrical array configuration and almost vanish in a single-planar array configuration. The WADM is an efficient tool suited for wire array load design and optimization in wide parameter ranges, including the loads with specific properties needed for the inertial confinement fusion research and laboratory astrophysics experiments. The data output from the WADM simulation can be used to simplify the radiation magnetohydrodynamics modeling of the wire array plasma.

The confining effectiveness of NiTiNb and NiTi SMA wire jackets for concrete

NASA Astrophysics Data System (ADS)

Choi, Eunsoo; Chung, Young-Soo; Choi, Jun-Hyeok; Kim, Hong-Taek; Lee, Hacksoo

2010-03-01

The purpose of this study is to assess the confining effectiveness of shape memory alloy (SMA) wire jackets for concrete. The performance of SMA wire jackets was compared to that of steel jackets. A prestrained martensitic SMA wire was wrapped around a concrete cylinder and then heated by a heating jacket. In the process, a confining stress around the cylinder was developed in the SMA wire due to the shape memory effect; this jacketing method can increase the strength and ductility of the cylinder under an axial compressive load. In this study, NiTi and NiTiNb SMA wires of 1.0 mm in diameter were used for the confinement. Recovery tests were conducted on the wires to assess their recovery and residual stress. The confinement by SMA wire jackets increased the strength slightly and greatly increased the ductility compared to the strength and ductility of plain concrete cylinders. The NiTiNb SMA wire jacket showed better performance than that of the NiTi SMA wire jacket. The confining effectiveness of the SMA wire jackets of this study was estimated to be similar to that of the steel jackets. This study showed the potential of the SMA wire jacketing method to retrofit reinforced concrete columns and protect them from seismic risks.

Fabrication of multifilamentary Nb/sub 3/(Al,Ge) wires through a modified jelly roll process

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

Tachikawa, K.; Kamisada, Y.; Suzuki, E.

Recently, development of Nb/sub 3/Al multifilamentary wires has gained much interests since high-field performance superior to that of Nb/sub 3/Sn can be expected in these wires. In this study, Nb/Al-Ge alloy composites were fabricated into multifilamentary wires through a modified jelly roll (MJR) process. A Nb mesh sheet produced at the Teledyne Wah Chang Co. was used as Nb component. An Al-Ge alloy prepared by a conventional casting process was forged and rolled into a sheet of 0.2 mm in thickness. The Nb/Al-Ge composite was prepared by wrapping the Nb mesh sheet together with the Al-Ge alloy sheet around amore » Nb core into a jelly roll form. The MJR composite was encased in a Cu-Ni alloy tube of which outer diameter was 43 mm. The resulting composite was hydrostatically pressed and extruded into a rod of 18 mm in diameter. A Nb barrier was then inserted between the MJR and the Cu-Ni jacket. The composite rod was swaged and drawn into a wire without any intermediate annealing. The wire was able to be drawn down to a very small diameter of 0.1 mm. The cross-sectional configuration of the MJR composite was not much disturbed by the fabrication. Superconducting transition temperature Tc of the wire, after different heat treatment including a rapid quenching from high temperatures by a continuous electron beam irradiation, was studied, and an onset Tc of 19.3K has been achieved.« less

A high-performance constant-temperature hot-wire anemometer

NASA Technical Reports Server (NTRS)

Watmuff, Jonathan H.

1994-01-01

A high-performance constant-temperature hot-wire anemometer has been designed based on a system theory analysis that can be extended to arbitrary order. A motivating factor behind the design was to achieve the highest possible frequency response while ensuring overall system stability. Based on these considerations, the design of the circuit and the selection of components is discussed in depth. Basic operating instructions are included in an operator's guide. The analysis is used to identify operating modes, observed in all anemometers, that are misleading in the sense that the operator can be deceived by interpreting an erroneous frequency response. Unlike other anemometers, this instrument provides front panel access to all the circuit parameters which affect system stability and frequency response. Instructions are given on how to identify and avoid these rather subtle and undesirable operating modes by appropriate adjustment of the controls. Details, such as fabrication drawings and a parts list, are provided to enable others to construct the instrument.

Assessment of exposure to EMF in a Danish case-control study of childhood cancer.

PubMed

Jensen, J K; Olsen, J H; Folkersen, E

1994-01-01

In Denmark it is permitted to draw overhead lines across residential areas. In connection with a Danish case-control study we developed a method for estimating the historical values of magnetic fields at residences. The study included 1,707 cases with childhood cancer and 4,788 matched population controls. A total of 16,082 different addresses had been occupied by the families from the time of conception until the date of diagnosis. The values of the extreme, maximum, middle and minimum 50 Hz magnetic field strengths originating from a 50-400 kV high-voltage installation were estimated for each of the dwellings included in a potential exposure area. 30 children were exposed to an average level of magnetic fields of 0.1 microT or more. The evaluated Danish method of exposure assessment was compared with the method for residential wiring codes developed by Wertheimer and Leeper /1/. We concluded that the US wiring codes are inappropriate for use in connection with the Danish electricity transmission system.

Strengthening of Aluminum Wires Treated with A206/Alumina Nanocomposites

PubMed Central

Marrero, Raúl; Li, Xiaochun; Choi, Hongseok

2018-01-01

This study sought to characterize aluminum nanocomposite wires that were fabricated through a cold-rolling process, having potential applications in TIG (tungsten inert gas) welding of aluminum. A206 (Al-4.5Cu-0.25Mg) master nanocomposites with 5 wt % γAl2O3 nanoparticles were first manufactured through a hybrid process combining semi-solid mixing and ultrasonic processing. A206/1 wt % γAl2O3 nanocomposites were fabricated by diluting the prepared master nanocomposites with a monolithic A206 alloy, which was then added to a pure aluminum melt. The fabricated Al–γAl2O3 nanocomposite billet was cold-rolled to produce an Al nanocomposite wire with a 1 mm diameter and a transverse area reduction of 96%. Containing different levels of nanocomposites, the fabricated samples were mechanically and electrically characterized. The results demonstrate a significantly higher strength of the aluminum wires with the nanocomposite addition. Further, the addition of alumina nanoparticles affected the wires’ electrical conductivity compared with that of pure aluminum and aluminum–copper alloys. The overall properties of the new material demonstrate that these wires could be an appealing alternative for fillers intended for aluminum welding. PMID:29534441

Investigation about the Chrome Steel Wire Arc Spray Process and the Resulting Coating Properties

NASA Astrophysics Data System (ADS)

Wilden, J.; Bergmann, J. P.; Jahn, S.; Knapp, S.; van Rodijnen, F.; Fischer, G.

2007-12-01

Nowadays, wire-arc spraying of chromium steel has gained an important market share for corrosion and wear protection applications. However, detailed studies are the basis for further process optimization. In order to optimize the process parameters and to evaluate the effects of the spray parameters DoE-based experiments had been carried out with high-speed camera shoots. In this article, the effects of spray current, voltage, and atomizing gas pressure on the particle jet properties, mean particle velocity and mean particle temperature and plume width on X46Cr13 wire are presented using an online process monitoring device. Moreover, the properties of the coatings concerning the morphology, composition and phase formation were subject of the investigations using SEM, EDX, and XRD-analysis. These deep investigations allow a defined verification of the influence of process parameters on spray plume and coating properties and are the basis for further process optimization.

Micro-structure and properties of Cu-0.5 wt%Ag alloy fine wires with severe cold plastic deformation treatment

NASA Astrophysics Data System (ADS)

Shu-sen, Wang; Yuan-wang, Zhang; Da-wei, Yao

2018-04-01

In this work, the Cu-0.5 wt% Ag alloy was prepared and then sold solution treated at 760 °C for 4 h and aged at 400 °C for 4 h. The severe cold plastic deformation treatment with a maximum true strain of 11.48 was applied to obtain the Cu-0.5 wt%Ag fine wires with the diameter of 0.087 mm. Then the fine wires were given eight intermediate heat treatments at 300 °C–350 °C for 10–60 min. Properties of the fine wires with different annealing heat treatments were analyzed, results showed that after the annealing process of 350 °C, 20 min was applied to Cu-0.5 wt% Ag fine wires, their conductivity, tensile strength and elongation could reach 98.6%IACS, 367 MPa and 8%, respectively. This demonstrated that the Cu-0.5 wt% Ag processes high strength and high conductivity properties and was a promising conductive material.

Fine pitch thermosonic wire bonding: analysis of state-of-the-art manufacturing capability

NASA Astrophysics Data System (ADS)

Cavasin, Daniel

1995-09-01

A comprehensive process characterization was performed at the Motorola plastic package assembly site in Selangor, Malaysia, to document the current fine pitch wire bond process capability, using state-of-the-art equipment, in an actual manufacturing environment. Two machines, representing the latest technology from two separate manufacturers, were operated one shift per day for five days, bonding a 132 lead Plastic Quad Flat Pack. Using a test device specifically designed for fine pitch wire bonding, the bonding programs were alternated between 107 micrometers and 92 micrometers pad pitch, running each pitch for a total of 1600 units per machine. Wire, capillary type, and related materials were standardized and commercially available. A video metrology measurement system, with a demonstrated six sigma repeatability band width of 0.51 micrometers , was utilized to measure the bonded units for bond dimensions and placement. Standard Quality Assurance (QA) metrics were also performed. Results indicate that state-of-the-art thermosonic wire bonding can achieve acceptable assembly yields at these fine pad pitches.

2D projection-based software application for mobile C-arms optimises wire placement in the proximal femur - An experimental study.

PubMed

Swartman, B; Frere, D; Wei, W; Schnetzke, M; Beisemann, N; Keil, H; Franke, J; Grützner, P A; Vetter, S Y

2017-10-01

A new software application can be used without fixed reference markers or a registration process in wire placement. The aim was to compare placement of Kirschner wires (K-wires) into the proximal femur with the software application versus the conventional method without guiding. As study hypothesis, we assumed less placement attempts, shorter procedure time and shorter fluoroscopy time using the software. The same precision inside a proximal femur bone model using the software application was premised. The software detects a K-wire within the 2D fluoroscopic image. By evaluating its direction and tip location, it superimposes a trajectory on the image, visualizing the intended direction of the K-wire. The K-wire was positioned in 20 artificial bones with the use of software by one surgeon; 20 bones served as conventional controls. A brass thumb tack was placed into the femoral head and its tip targeted with the wire. Number of placement attempts, duration of the procedure, duration of fluoroscopy time and distance to the target in a postoperative 3D scan were recorded. Compared with the conventional method, use of the application showed fewer attempts for optimal wire placement (p=0.026), shorter duration of surgery (p=0.004), shorter fluoroscopy time (p=0.024) and higher precision (p=0.018). Final wire position was achieved in the first attempt in 17 out of 20 cases with the software and in 9 out of 20 cases with the conventional method. The study hypothesis was confirmed. The new application optimised the process of K-wire placement in the proximal femur in an artificial bone model while also improving precision. Benefits lie especially in the reduction of placement attempts and reduction of fluoroscopy time under the aspect of radiation protection. The software runs on a conventional image intensifier and can therefore be easily integrated into the daily surgical routine. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low temperature junction growth using hot-wire chemical vapor deposition

DOEpatents

Wang, Qi; Page, Matthew; Iwaniczko, Eugene; Wang, Tihu; Yan, Yanfa

2014-02-04

A system and a process for forming a semi-conductor device, and solar cells (10) formed thereby. The process includes preparing a substrate (12) for deposition of a junction layer (14); forming the junction layer (14) on the substrate (12) using hot wire chemical vapor deposition; and, finishing the semi-conductor device.

Dynamics of vapor emissions at wire explosion thresholda)

NASA Astrophysics Data System (ADS)

Belony, Paul A.; Kim, Yong W.

2010-10-01

X-pinch plasmas have been actively studied in the recent years. Numerical simulation of the ramp-up of metallic vapor emissions from wire specimens shows that under impulsive Ohmic heating the wire core invariably reaches a supercritical state before explosion. The heating rate depends sensitively on the local wire resistance, leading to highly variable vapor emission flux along the wire. To examine the vapor emission process, we have visualized nickel wire explosions by means of shock formation in air. In a single explosion as captured by shadowgraphy, there usually appear several shocks with spherical or cylindrical wave front originating from different parts of the wire. Growth of various shock fronts in time is well characterized by a power-law scaling in one form or another. Continuum emission spectra are obtained and calibrated to measure temperature near the explosion threshold. Shock front structures and vapor plume temperature are examined.

Pull-pull position control of dual motor wire rope transmission.

PubMed

Guo, Quan; Jiao, Zongxia; Yan, Liang; Yu, Qian; Shang, Yaoxing

2016-08-01

Wire rope transmission is very efficient because of the small total moving object mass. The wire rope could only transmit pulling force. Therefore it has to be kept in a tightened state during transmission; in high speed applications the dynamic performance depends on the rope's stiffness, which can be adjusted by the wire rope tension. To improve the system dynamic performance output, this paper proposes a novel pull-pull method based on dual motors connected by wire ropes, for precise, high speed position control applications. The method can regulate target position and wire rope tension simultaneously. Wire ropes remain in a pre-tightening state at all times, which prevents the influence of elasticity and reduces the position tracking error in the changing direction process. Simulations and experiments were conducted; the results indicate that both position precision and superior dynamic performance can be synchronously achieved. The research is relevant to space craft precision pointing instruments.

SpaceWire: IP, Components, Development Support and Test Equipment

NASA Astrophysics Data System (ADS)

Parkes, S.; McClements, C.; Mills, S.; Martin, I.

SpaceWire is a communications network for use onboard spacecraft. It is designed to connect high data-rate sensors, large solid-state memories, processing units and the downlink telemetry subsystem providing an integrated data-handling network. SpaceWire links are serial, high-speed (2 Mbits/sec to 400 Mbits/sec), bi-directional, full-duplex, pointto- point data links which connect together SpaceWire equipment. Application information is sent along a SpaceWire link in discrete packets. Control and time information can also be sent along SpaceWire links. SpaceWire is defined in the ECSS-E50-12A standard [1]. With the adoption of SpaceWire on many space missions the ready availability of intellectual property (IP) cores, components, software drivers, development support, and test equipment becomes a major issue for those developing satellites and their electronic subsystems. This paper describes the work being done at the University of Dundee and STAR-Dundee Ltd with ESA, BNSC and internal funding to make these essential items available. STAR-Dundee is a spin-out company of the University of Dundee set up specifically to support users of SpaceWire.

Predictors of temporary epicardial pacing wires use after valve surgery

PubMed Central

2014-01-01

Background Although temporary cardiac pacing is infrequently needed, temporary epicardial pacing wires are routinely inserted after valve surgery. As they are associated with infrequent, but life threatening complications, and the decreased need for postoperative pacing in a group of low risk patients; this study aims to identify the predictors of temporary cardiac pacing after valve surgery. Methods A retrospective analysis of data collected prospectively on 400 consecutive valve surgery patients between May 2002 and December 2012 was performed. Patients were grouped according to avoidance or insertion of temporary pacing wires, and were further subdivided according to temporary cardiac pacing need. Multiple logistic regression was used to determine the predictors of temporary cardiac pacing. Results 170 (42.5%) patients did not have insertion of temporary pacing wires and none of them needed temporary pacing. 230 (57.5%) patients had insertion of temporary pacing wires and among these, only 55 (23.9%) required temporary pacing who were compared with the remaining 175 (76.1%) patients in the main analysis. The determinants of temporary cardiac pacing (adjusted odds ratios; 95% confidence interval) were as follows: increased age (1.1; 1.1, 1.3, p = 0.002), New York Heart Association class III- IV (5.6; 1.6, 20.2, p = 0.008) , pulmonary artery pressure ≥ 50 mmHg (22.0; 3.4, 142.7, p = 0.01), digoxin use (8.0; 1.3, 48.8, p = 0.024), multiple valve surgery (13.5; 1.5, 124.0, p = 0.021), aorta cross clamp time ≥ 60 minutes (7.8; 1.6, 37.2, p = 0.010), and valve annulus calcification (7.9; 2.0, 31.7, p = 0.003). Conclusion Although limited by sample size, the present results suggest that routine use of temporary epicardial pacing wires after valve surgery is only necessary for high risk patients. Preoperative identification and aggressive management of predictors of temporary cardiac pacing and the possible modulation of intraoperative techniques can decrease the need of temporary cardiac pacing. Prospective randomized controlled studies on a larger number of patients are necessary to draw solid conclusions regarding the selective use of temporary epicardial pacing wires in valve surgery. PMID:24521215

Composite ceramic superconducting wires for electric motor applications

NASA Astrophysics Data System (ADS)

Halloran, John W.

1990-04-01

Silver clad polycrystalline Y-123 wire is being fabricated with a continuous reel-to-reel process. Scale-up activities are underway to produce enough wire for the field coils of the HTSC motor. Green HTSC fiber were produced in kilometer lengths, and sintered wires up to 166 meters long. The 77K Jc values are 1000-2800 A/sq cm in self field. To improve Jc of the Y-123 wire, development began on directional crystallization, including preliminary work at A. D. Little and Oak Ridge National Lab. Large lots of BiSCCO material were produced to fabricated fibers and sintered polycrystalline BiSSCO wire as rolled tape. Work continued in collaboration with Sandia and Los Alamos National Laboratories on rapid thermal processing of Y-123, with most emphasis on characterizing the rapid oxygenation effect. The design of the HTSC homopolar motor has been improved to increase the output from field coils by using six smaller coils, each with separately optimized current. Motor construction is in progress. Preliminary design is underway on a dc heteropolar motor with HTSC field windings and armature and a brushless trapped flux permanent magnet dc motor, in which the field is produced by trapped flux in an HTSC rotor.

Intermetallic alloy welding wires and method for fabricating the same

DOEpatents

Santella, M.L.; Sikka, V.K.

1996-06-11

Welding wires for welding together intermetallic alloys of nickel aluminides, nickel-iron aluminides, iron aluminides, or titanium aluminides, and preferably including additional alloying constituents are fabricated as two-component, clad structures in which one component contains the primary alloying constituent(s) except for aluminum and the other component contains the aluminum constituent. This two-component approach for fabricating the welding wire overcomes the difficulties associated with mechanically forming welding wires from intermetallic alloys which possess high strength and limited ductilities at elevated temperatures normally employed in conventional metal working processes. The composition of the clad welding wires is readily tailored so that the welding wire composition when melted will form an alloy defined by the weld deposit which substantially corresponds to the composition of the intermetallic alloy being joined. 4 figs.

Intermetallic alloy welding wires and method for fabricating the same

DOEpatents

Santella, Michael L.; Sikka, Vinod K.

1996-01-01

Welding wires for welding together intermetallic alloys of nickel aluminides, nickel-iron aluminides, iron aluminides, or titanium aluminides, and preferably including additional alloying constituents are fabricated as two-component, clad structures in which one component contains the primary alloying constituent(s) except for aluminum and the other component contains the aluminum constituent. This two-component approach for fabricating the welding wire overcomes the difficulties associated with mechanically forming welding wires from intermetallic alloys which possess high strength and limited ductilities at elevated temperatures normally employed in conventional metal working processes. The composition of the clad welding wires is readily tailored so that the welding wire composition when melted will form an alloy defined by the weld deposit which substantially corresponds to the composition of the intermetallic alloy being joined.

The Effect of Material Removal on the Corrosion Resistance and Biocompatibility of Nitinol Laser-Cut and Wire-Form Products

NASA Astrophysics Data System (ADS)

Decker, Jennifer Fino; Trépanier, Christine; Vien, Lot; Pelton, Alan R.

2011-07-01

Laser cutting and wire forming are two of the most commonly used processes in the manufacture of Nitinol medical devices. This study explores how varying the amount of material removed during the final surface treatment steps affects the corrosion resistance of Z-type stents that have either been laser-cut from tube or shape set from wire. All parts were subjected to a typical heat treatment process necessary to achieve an Austenite finish (Af) temperature of 25 ± 5 °C, and were subsequently post-processed with an electrochemical passivation process. The total weight loss during post-processing was recorded and the process adjusted to create groups with less than 5%, less than 10%, and less than 25% amounts of weight loss. The parts were then crimped to 6 mm and allowed to expand back to their original diameter. The corrosion test results showed that on average both groups of Z-stents experienced an increase in the corrosion breakdown potential and a decrease in the standard deviation with increasing amounts of material removal. In addition, less material removal is required from the wire-form Z-stents as compared to the laser-cut Z-stents to achieve high corrosion resistance. Finally, 7 day nickel ion release tests performed on the wire-formed Z-stents showed a dramatic decrease from 0.0132 mg of nickel leached per day for the low weight loss group to approximately 0.001 mg/day for the medium and high weight loss groups.

Conversion of electromagnetic energy in Z-pinch process of single planar wire arrays at 1.5 MA

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

Liangping, Wang; Mo, Li; Juanjuan, Han

The electromagnetic energy conversion in the Z-pinch process of single planar wire arrays was studied on Qiangguang generator (1.5 MA, 100 ns). Electrical diagnostics were established to monitor the voltage of the cathode-anode gap and the load current for calculating the electromagnetic energy. Lumped-element circuit model of wire arrays was employed to analyze the electromagnetic energy conversion. Inductance as well as resistance of a wire array during the Z-pinch process was also investigated. Experimental data indicate that the electromagnetic energy is mainly converted to magnetic energy and kinetic energy and ohmic heating energy can be neglected before the final stagnation. Themore » kinetic energy can be responsible for the x-ray radiation before the peak power. After the stagnation, the electromagnetic energy coupled by the load continues increasing and the resistance of the load achieves its maximum of 0.6–1.0 Ω in about 10–20 ns.« less

Closed-Loop Process Control for Electron Beam Freeform Fabrication and Deposition Processes

NASA Technical Reports Server (NTRS)

Taminger, Karen M. (Inventor); Hofmeister, William H. (Inventor); Martin, Richard E. (Inventor); Hafley, Robert A. (Inventor)

2013-01-01

A closed-loop control method for an electron beam freeform fabrication (EBF(sup 3)) process includes detecting a feature of interest during the process using a sensor(s), continuously evaluating the feature of interest to determine, in real time, a change occurring therein, and automatically modifying control parameters to control the EBF(sup 3) process. An apparatus provides closed-loop control method of the process, and includes an electron gun for generating an electron beam, a wire feeder for feeding a wire toward a substrate, wherein the wire is melted and progressively deposited in layers onto the substrate, a sensor(s), and a host machine. The sensor(s) measure the feature of interest during the process, and the host machine continuously evaluates the feature of interest to determine, in real time, a change occurring therein. The host machine automatically modifies control parameters to the EBF(sup 3) apparatus to control the EBF(sup 3) process in a closed-loop manner.

Attainment of students’ conception in magnetic fields by using of direct observation and symbolic language ability

NASA Astrophysics Data System (ADS)

Desy Fatmaryanti, Siska; Suparmi; Sarwanto; Ashadi

2017-11-01

This study focuses on description attainment of students’ conception in the magnetic field. The conception was based by using of direct observation and symbolic language ability. The method used is descriptive quantitative research. The subject of study was about 86 students from 3 senior high school at Purworejo. The learning process was done by guided inquiry model. During the learning, students were required to actively investigate the concept of a magnetic field around a straight wire electrical current Data retrieval was performed using an instrument in the form of a multiple choice test reasoned and observation during the learning process. There was four indicator of direct observation ability and four indicators of symbolic language ability to grouping category of students conception. The results of average score showed that students conception about the magnitude more better than the direction of magnetic fields in view of symbolic language. From the observation, we found that students could draw the magnetic fields line not from a text book but their direct observation results. They used various way to get a good accuracy of observation results. Explicit recommendations are presented in the discussion section at the end of this paper.

Effect of electrical spot welding on load deflection rate of orthodontic wires.

PubMed

Alavi, Shiva; Abrishami, Arezoo

2015-01-01

One of the methods used for joining metals together is welding, which can be carried out using different techniques such as electric spot welding. This study evaluated the effect of electric spot welding on the load deflection rate of stainless steel and chromium-cobalt orthodontic wires. In this experimental-laboratory study, load deflection rate of 0.016 × 0.022 inch stainless steel and chromium cobalt wires were evaluated in five groups (n =18): group one: Stainless steel wires, group two: chromium-cobalt wires, group three: stainless steel wires welded to stainless steel wires, group four: Stainless steel wires welded to chromium-cobalt wires, group five: chromium-cobalt wire welded to chromium-cobalt wires. Afterward, the forces induced by the samples in 0.5 mm, 1 mm, 1.5 mm deflection were measured using a universal testing machine. Then mean force measured for each group was compared with other groups. The data were analyzed using repeated measure analysis of variance (ANOVA), one-way ANOVA, and paired t-test by the SPSS software. The significance level was set as 0.05. The Tukey test showed that there were significant differences between the load deflection rates of welded groups compared to control ones (P < 0.001). Considering the limitation of this study, the electric spot welding process performed on stainless steel and chromium-cobalt wires increased their load deflection rates.

Decreasing diameter fluctuation of polymer optical fiber with optimized drawing conditions

NASA Astrophysics Data System (ADS)

Çetinkaya, Onur; Wojcik, Grzegorz; Mergo, Pawel

2018-05-01

The diameter fluctuations of poly(methyl methacrylate) based polymer optical fibers, during drawing processes, have been comprehensively studied. In this study, several drawing parameters were selected for investigation; such as drawing tensions, preform diameters, preform feeding speeds, and argon flows. Varied drawing tensions were used to draw fibers, while other parameters were maintained at constant. At a later stage in the process, micro-structured polymer optical fibers were drawn under optimized drawing conditions. Fiber diameter deviations were reduced to 2.2%, when a 0.2 N drawing tension was employed during the drawing process. Higher drawing tensions led to higher diameter fluctuations. The Young’s modulus of fibers drawn with different tensions was also measured. Our results showed that fiber elasticity increased as drawing tensions decreased. The inhomogeneity of fibers was also determined by comparing the deviation of Young’s modulus.

Study on nondestructive detection system based on x-ray for wire ropes conveyer belt

NASA Astrophysics Data System (ADS)

Miao, Changyun; Shi, Boya; Wan, Peng; Li, Jie

2008-03-01

A nondestructive detection system based on X-ray for wire ropes conveyer belt is designed by X-ray detection technology. In this paper X-ray detection principle is analyzed, a design scheme of the system is presented; image processing of conveyer belt is researched and image processing algorithms are given; X-ray acquisition receiving board is designed with the use of FPGA and DSP; the software of the system is programmed by C#.NET on WINXP/WIN2000 platform. The experiment indicates the system can implement remote real-time detection of wire ropes conveyer belt images, find faults and give an alarm in time. The system is direct perceived, strong real-time and high accurate. It can be used for fault detection of wire ropes conveyer belts in mines, ports, terminals and other fields.

Effects of beam configurations on wire melting and transfer behaviors in dual beam laser welding with filler wire

NASA Astrophysics Data System (ADS)

Ma, Guolong; Li, Liqun; Chen, Yanbin

2017-06-01

Butt joints of 2 mm thick stainless steel with 0.5 mm gap were fabricated by dual beam laser welding with filler wire technique. The wire melting and transfer behaviors with different beam configurations were investigated detailedly in a stable liquid bridge mode and an unstable droplet mode. A high speed video system assisted by a high pulse diode laser as an illumination source was utilized to record the process in real time. The difference of welding stability between single and dual beam laser welding with filler wire was also compartively studied. In liquid bridge transfer mode, the results indicated that the transfer process and welding stability were disturbed in the form of "broken-reformed" liquid bridge in tandem configuration, while improved by stabilizing the molten pool dynamics with a proper fluid pattern in side-by-side configuration, compared to sigle beam laser welding with filler wire. The droplet transfer period and critical radius were studied in droplet transfer mode. The transfer stability of side-by-side configuration with the minium transfer period and critical droplet size was better than the other two configurations. This was attributed to that the action direction and good stability of the resultant force which were beneficial to transfer process in this case. The side-by-side configuration showed obvious superiority on improving welding stability in both transfer modes. An acceptable weld bead was successfully generated even in undesirable droplet transfer mode under the present conditions.

Evolution of flexural rigidity according to the cross-sectional dimension of a superelastic nickel titanium orthodontic wire.

PubMed

Garrec, Pascal; Tavernier, Bruno; Jordan, Laurence

2005-08-01

The choice of the most suitable orthodontic wire for each stage of treatment requires estimation of the forces generated. In theory, the selection of wire sequences should initially utilize a lower flexural rigidity; thus clinicians use smaller round cross-sectional dimension wires to generate lighter forces during the preliminary alignment stage. This assessment is true for conventional alloys, but not necessarily for superelastic nickel titanium (NiTi). In this case, the flexural rigidity dependence on cross-sectional dimension differs from the linear elasticity prediction because of the martensitic transformation process. It decreases with increasing deflection and this phenomenon is accentuated in the unloading process. This behaviour should lead us to consider differently the biomechanical approach to orthodontic treatment. The present study compared bending in 10 archwires made from NiTi orthodontics alloy of two cross-sectional dimensions. The results were based on microstructural and mechanical investigations. With conventional alloys, the flexural rigidity was constant for each wire and increased largely with the cross-sectional dimension for the same strain. With NiTi alloys, the flexural rigidity is not constant and the influence of size was not as important as it should be. This result can be explained by the non-constant elastic modulus during the martensite transformation process. Thus, in some cases, treatment can begin with full-size (rectangular) wires that nearly fill the bracket slot with a force application deemed to be physiologically desirable for tooth movement and compatible with patient comfort.

Real-time monitoring of laser hot-wire cladding of Inconel 625

NASA Astrophysics Data System (ADS)

Liu, Shuang; Liu, Wei; Harooni, Masoud; Ma, Junjie; Kovacevic, Radovan

2014-10-01

Laser hot-wire cladding (LHWC), characterized by resistance heating of the wire, largely increases the productivity and saves the laser energy. However, the main issue of applying this method is the occurrence of arcing which causes spatters and affects the stability of the process. In this study, an optical spectrometer was used for real-time monitoring of the LHWC process. The corresponding plasma intensity was analyzed under various operating conditions. The electron temperature of the plasma was calculated for elements of nickel and chromium that mainly comprised the plasma plume. There was a correlation between the electron temperature and the stability of the process. The characteristics of the resulted clad were also investigated by measuring the dilution, hardness and microstructure.

Flexible Microstrip Circuits for Superconducting Electronics

NASA Technical Reports Server (NTRS)

Chervenak, James; Mateo, Jennette

2013-01-01

Flexible circuits with superconducting wiring atop polyimide thin films are being studied to connect large numbers of wires between stages in cryogenic apparatus with low heat load. The feasibility of a full microstrip process, consisting of two layers of superconducting material separated by a thin dielectric layer on 5 mil (approximately 0.13 mm) Kapton sheets, where manageable residual stress remains in the polyimide film after processing, has been demonstrated. The goal is a 2-mil (approximately 0.051-mm) process using spin-on polyimide to take advantage of the smoother polyimide surface for achieving highquality metal films. Integration of microstrip wiring with this polyimide film may require high-temperature bakes to relax the stress in the polyimide film between metallization steps.

Measuring the Pain Area: An Intra- and Inter-Rater Reliability Study Using Image Analysis Software.

PubMed

Dos Reis, Felipe Jose Jandre; de Barros E Silva, Veronica; de Lucena, Raphaela Nunes; Mendes Cardoso, Bruno Alexandre; Nogueira, Leandro Calazans

2016-01-01

Pain drawings have frequently been used for clinical information and research. The aim of this study was to investigate intra- and inter-rater reliability of area measurements performed on pain drawings. Our secondary objective was to verify the reliability when using computers with different screen sizes, both with and without mouse hardware. Pain drawings were completed by patients with chronic neck pain or neck-shoulder-arm pain. Four independent examiners participated in the study. Examiners A and B used the same computer with a 16-inch screen and wired mouse hardware. Examiner C used a notebook with a 16-inch screen and no mouse hardware, and Examiner D used a computer with an 11.6-inch screen and a wireless mouse. Image measurements were obtained using GIMP and NIH ImageJ computer programs. The length of all the images was measured using GIMP software to a set scale in ImageJ. Thus, each marked area was encircled and the total surface area (cm(2) ) was calculated for each pain drawing measurement. A total of 117 areas were identified and 52 pain drawings were analyzed. The intrarater reliability between all examiners was high (ICC = 0.989). The inter-rater reliability was also high. No significant differences were observed when using different screen sizes or when using or not using the mouse hardware. This suggests that the precision of these measurements is acceptable for the use of this method as a measurement tool in clinical practice and research. © 2014 World Institute of Pain.

Method for wiring allocation and switch configuration in a multiprocessor environment

DOEpatents

Aridor, Yariv [Zichron Ya'akov, IL; Domany, Tamar [Kiryat Tivon, IL; Frachtenberg, Eitan [Jerusalem, IL; Gal, Yoav [Haifa, IL; Shmueli, Edi [Haifa, IL; Stockmeyer, legal representative, Robert E.; Stockmeyer, Larry Joseph [San Jose, CA

2008-07-15

A method for wiring allocation and switch configuration in a multiprocessor computer, the method including employing depth-first tree traversal to determine a plurality of paths among a plurality of processing elements allocated to a job along a plurality of switches and wires in a plurality of D-lines, and selecting one of the paths in accordance with at least one selection criterion.

Manufacture and quality control of interconnecting wire hardnesses, Volume 1

NASA Technical Reports Server (NTRS)

1972-01-01

A standard is presented for manufacture, installation, and quality control of eight types of interconnecting wire harnesses. The processes, process controls, and inspection and test requirements reflected are based on acknowledgment of harness design requirements, acknowledgment of harness installation requirements, identification of the various parts, materials, etc., utilized in harness manufacture, and formulation of a typical manufacturing flow diagram for identification of each manufacturing and quality control process, operation, inspection, and test. The document covers interconnecting wire harnesses defined in the design standard, including type 1, enclosed in fluorocarbon elastomer convolute, tubing; type 2, enclosed in TFE convolute tubing lines with fiberglass braid; type 3, enclosed in TFE convolute tubing; and type 5, combination of types 3 and 4. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated.

Wrapping process for fabrication of A-15 superconducting composite wires

DOEpatents

Suenaga, M.; Klamut, C.J.; Luhman, T.S.

1980-08-15

A method for fabricating superconducting wires wherein a billet of copper containing filaments of niobium or vanadium is rolled to form a strip which is wrapped about a tin-alloy core to form a composite. The alloy is a tin-copper alloy for niobium filaments and a gallium-copper alloy for vanadium filaments. The composite is then drawn down to a desired wire size and heat treated. During the heat treatment process, the tin in the bronze reacts with the niobium to form the superconductor niobium tin. In the case where vanadium is used, the gallium in the gallium bronze reacts with the vanadium to form the superconductor vanadium gallium. This new process eliminates the costly annealing steps, external tin plating and drilling of bronze ingots required in a number of prior art processes.

Straightforward Downsizing of Inclusions in NiTi Alloys: A New Generation of SMA Wires with Outstanding Fatigue Life

NASA Astrophysics Data System (ADS)

Coda, Alberto; Cadelli, Andrea; Zanella, Matteo; Fumagalli, Luca

2018-03-01

One of most debated aspects around Nitinol quality is microcleanliness, nowadays considered as the main factor affecting fatigue life. Recent results demonstrate that fatigue is undoubtedly associated with inclusions which can act as crack initiators. However, type, size, and distribution of such particles have been observed to strongly depend on Ni/Ti ratio as well as melting and thermo-mechanical processes. Therefore, if a general reduction of non-metallic inclusions is expected to generate a beneficial effect in improving lifetime of Nitinol, on the other hand this necessarily involves a hard review of both material melting and processing. In this work, the characterization of the fatigue behavior of SMA wires with diameter below 100 µm is presented. The wires were prepared by a peculiar, non-standard combination of melting and thermo-mechanical processes (Clean Melt technology). Thermo-mechanical cycling was carried out and the fracture surfaces of all failed wires were investigated by scanning electron microscopy. A robust set of data was collected and analyzed by using the statistics of extremes. Results clearly demonstrate that in the new NiTi Clean Melt alloy the maximum inclusion size and area fraction are significantly reduced compared to standard Nitinol. This offers meaningful improvement in fatigue resistance over standard wires.

Making Connections.

ERIC Educational Resources Information Center

Garbe, Edward

1998-01-01

Discusses enhancing a college's competitive position by offering technological capabilities to its students, including the planning process and wiring installation issues to be considered. Highlights two examples concerning building the wiring infrastructure to support multipurpose, technology-rich learning environments. (GR)

Research on Mechanisms and Controlling Methods of Macro Defects in TC4 Alloy Fabricated by Wire Additive Manufacturing.

PubMed

Ji, Lei; Lu, Jiping; Tang, Shuiyuan; Wu, Qianru; Wang, Jiachen; Ma, Shuyuan; Fan, Hongli; Liu, Changmeng

2018-06-28

Wire feeding additive manufacturing (WFAM) has broad application prospects because of its advantages of low cost and high efficiency. However, with the mode of lateral wire feeding, including wire and laser additive manufacturing, gas tungsten arc additive manufacturing etc., it is easy to generate macro defects on the surface of the components because of the anisotropy of melted wire, which limits the promotion and application of WFAM. In this work, gas tungsten arc additive manufacturing with lateral wire feeding is proposed to investigate the mechanisms of macro defects. The results illustrate that the defect forms mainly include side spatters, collapse, poor flatness, and unmelted wire. It was found that the heat input, layer thickness, tool path, and wire curvature can have an impact on the macro defects. Side spatters are the most serious defects, mainly because the droplets cannot be transferred to the center of the molten pool in the lateral wire feeding mode. This research indicates that the macro defects can be controlled by optimizing the process parameters. Finally, block parts without macro defects were fabricated, which is meaningful for the further application of WFAM.

Facile fabrication of wire-type indium gallium zinc oxide thin-film transistors applicable to ultrasensitive flexible sensors.

PubMed

Kim, Yeong-Gyu; Tak, Young Jun; Kim, Hee Jun; Kim, Won-Gi; Yoo, Hyukjoon; Kim, Hyun Jae

2018-04-03

We fabricated wire-type indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) using a self-formed cracked template based on a lift-off process. The electrical characteristics of wire-type IGZO TFTs could be controlled by changing the width and density of IGZO wires through varying the coating conditions of template solution or multi-stacking additional layers. The fabricated wire-type devices were applied to sensors after functionalizing the surface. The wire-type pH sensor showed a sensitivity of 45.4 mV/pH, and this value was an improved sensitivity compared with that of the film-type device (27.6 mV/pH). Similarly, when the wire-type device was used as a glucose sensor, it showed more variation in electrical characteristics than the film-type device. The improved sensing properties resulted from the large surface area of the wire-type device compared with that of the film-type device. In addition, we fabricated wire-type IGZO TFTs on flexible substrates and confirmed that such structures were very resistant to mechanical stresses at a bending radius of 10 mm.

Drawing links between the autism cognitive profile and imagination: Executive function and processing bias in imaginative drawings by children with and without autism.

PubMed

Ten Eycke, Kayla D; Müller, Ulrich

2018-02-01

Little is known about the relation between cognitive processes and imagination and whether this relation differs between neurotypically developing children and children with autism. To address this issue, we administered a cognitive task battery and Karmiloff-Smith's drawing task, which requires children to draw imaginative people and houses. For children with autism, executive function significantly predicted imaginative drawing. In neurotypically developing controls, executive function and cognitive-perceptual processing style predicted imaginative drawing, but these associations were moderated by mental age. In younger (neurotypically developing) children, better executive function and a local processing bias were associated with imagination; in older children, only a global bias was associated with imagination. These findings suggest that (a) with development there are changes in the type of cognitive processes involved in imagination and (b) children with autism employ a unique cognitive strategy in imaginative drawing.

Feasibility study of an active soft catheter actuated by SMA wires

NASA Astrophysics Data System (ADS)

Konh, Bardia; Karimi, Saeed; Miller, Scott

2018-03-01

This study aims to assess the feasibility of using a combination of thin elastomer tubes and SMA wires to develop an active catheter. Cardiac catheters have been widely used in investigational and interventional procedures such as angiography, angioplasty, electro- physiology, and endocardial ablation. The commercial models manually steer inside the patient's body via internally installed pull wires. Active catheters, on the other hand, have the potential to revolutionize surgical procedures because of their computer-controlled and enhanced motion. Shape memory alloys have been used for almost a decade as a trustworthy actuator for biomedical applications. In this work, SMA wires were attached to a small pressurized elastomer tube to realize deflection. The tube was pressurized to maintain a constant stress on the SMA wires. The tip motion via actuation of SMA wires was then measured and reported. The results of this study showed that by adopting an appropriate training process for the SMA wires prior to performing the experiments and adopting an appropriate internal pressure for the elastomer tube, less external loads on SMA wires would be needed for a consistent actuation.

Mechanical behavior of M-Wire and conventional NiTi wire used to manufacture rotary endodontic instruments.

PubMed

Pereira, Erika S J; Gomes, Renata O; Leroy, Agnès M F; Singh, Rupinderpal; Peters, Ove A; Bahia, Maria G A; Buono, Vicente T L

2013-12-01

Comparison of physical and mechanical properties of one conventional and a new NiTi wire, which had received an additional thermomechanical treatment. Specimens of both conventional (NiTi) and the new type of wire, called M-Wire (MW), were subjected to tensile and three-point bending tests, Vickers microhardness measurements, and to rotating-bending fatigue tests at a strain-controlled level of 6%. Fracture surfaces were observed by scanning electron microscopy and the non-deformed microstructures by transmission electron microscopy. The thermomechanical treatment applied to produce the M-Wire apparently increased the tensile strength and Vickers microhardness of the material, but its apparent Young modulus was smaller than that of conventionally treated NiTi. The three-point bending tests showed a higher flexibility for MW which also exhibited a significantly higher number of cycles to failure. M-Wire presented mechanical properties that can render endodontic instruments more flexible and fatigue resistant than those made with conventionally processed NiTi wires. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Wire Crimp Termination Verification Using Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Perey, Daniel F.; Cramer, K. Elliott; Yost, William T.

2007-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp terminations is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp termination and wire is shown to correlate with the results of a destructive pull test, which is a standard for assessing crimp wire junction quality. Various crimp junction pathologies such as undercrimping, missing wire strands, incomplete wire insertion, partial insulation removal, and incorrect wire gauge are ultrasonically tested, and their results are correlated with pull tests. Results show that the nondestructive ultrasonic measurement technique consistently (as evidenced with destructive testing) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying this technique while wire crimps are installed is also presented. The instrument is based on a two-jaw type crimp tool suitable for butt-splice type connections. Finally, an approach for application to multipin indenter type crimps will be discussed.

Connectivity, Doping, and Anisotropy in Highly Dense Magnesium Diboride (MgB2)

NASA Astrophysics Data System (ADS)

Li, Guangze

Magnesium diboride (MgB2) is a superconducting material which can be potentially used in many applications such as magnetic resonance imaging system (MRI), wind turbine generators and high energy physics facilities. The major advantages of MgB2 over other superconductors include its relatively high critical temperature of about 39 K, its low cost of raw materials, its simple crystal structure, and its round multifilament form when in the form of superconducting wires. Over the past fourteen years, much effort has been made to develop MgB2 wires with excellent superconducting properties, particularly the critical current density J c. However, this research has been limited by technical difficulties such as high porosity and weak connectivity in MgB2, relatively small flux pinning strength, low upper critical field B c2 and relatively high anisotropy. The goal of this dissertation is to understand the relationship between superconducting properties, microstructure, and reaction mechanisms in MgB 2. In particular, the influences of connectivity, B c2, anisotropy and flux pinning were investigated in terms of the effects of these variables on the Jcs and n-values of MgB2 superconducting wires (n-value is a parameter which indicates the sharpness of resistive V-I transition). The n -values of traditional "Powder in Tube (PIT)" processed MgB2 wires were improved by optimizing precursor species after the identification of microstructural defects such as so-called "sausaging problems". Also, it was found that "high porosity and weak connectivity" was one of the most critical issues which limited the J c performance in typical MgB2. To overcome this problem, highly dense, well-connected MgB2 conductors were successfully fabricated by adopting an innovative "Advanced Internal Magnesium Infiltration (AIMI)" process. A careful study on the reaction kinetics together with the microstructural evidence demonstrated how the MgB2 layer was formed as the infiltration process proceeded. As a result, it is possible to control the MgB2 layer growth in the AIMI-processed MgB 2 wires. The best AIMI wires, with improved density and connectivity, accomplished an outstanding layer Jc, which was 1.0 x 105 A/cm2 at 4.2 K and 10 T, nearly 10 times higher than the Jcs of PIT wires. The engineering Je of AIMI wires, namely the critical current over the whole cross-sectional area in the wire, achieved 1.7 x 104 A/cm2 at 4.2 K, 10 T, 200 % higher than those of PIT wires. Finally, two promising dopants, Dy2O3 and O, were engineered to incorporate with MgB2. Dy 2O3 nanopowders, co-doped with C in AIMI wires, enhanced the Jc performance at elevated temperatures such as 20 K. Oxygen, on the other hand, doped into MgB2 thin films through a newly-developed O2 annealing process, improved Bc2 to 14 T at 21 K. Both of the doping studies were helpful to understand the superconducting nature of MgB2.

Experimental investigations of ablation stream interaction dynamics in tungsten wire arrays: Interpenetration, magnetic field advection, and ion deflection

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

Swadling, G. F.; Lebedev, S. V.; Hall, G. N.

2016-05-01

Experiments have been carried out to investigate the collisional dynamics of ablation streams produced by cylindrical wire array z-pinches. A combination of laser interferometric imaging, Thomson scattering, and Faraday rotation imaging has been used to make a range of measurements of the temporal evolution of various plasma and flow parameters. Our paper presents a summary of previously published data, drawing together a range of different measurements in order to give an overview of the key results. The paper focuses mainly on the results of experiments with tungsten wire arrays. Early interferometric imaging measurements are reviewed, then more recent Thomson scatteringmore » measurements are discussed; these measurements provided the first direct evidence of ablation stream interpenetration in a wire array experiment. Combining the data from these experiments gives a view of the temporal evolution of the tungsten stream collisional dynamics. In the final part of the paper, we present new experimental measurements made using an imaging Faraday rotation diagnostic. Our experiments investigated the structure of magnetic fields near the array axis directly; the presence of a magnetic field has previously been inferred based on Thomson scattering measurements of ion deflection near the array axis. Although the Thomson and Faraday measurements are not in full quantitative agreement, the Faraday data do qualitatively supports the conjecture that the observed deflections are induced by a static toroidal magnetic field, which has been advected to the array axis by the ablation streams. It is likely that detailed modeling will be needed in order to fully understand the dynamics observed in the experiment.« less

Experimental investigations of ablation stream interaction dynamics in tungsten wire arrays: Interpenetration, magnetic field advection, and ion deflection

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

Swadling, G. F.; Lebedev, S. V.; Hall, G. N.

2016-05-15

Experiments have been carried out to investigate the collisional dynamics of ablation streams produced by cylindrical wire array z-pinches. A combination of laser interferometric imaging, Thomson scattering, and Faraday rotation imaging has been used to make a range of measurements of the temporal evolution of various plasma and flow parameters. This paper presents a summary of previously published data, drawing together a range of different measurements in order to give an overview of the key results. The paper focuses mainly on the results of experiments with tungsten wire arrays. Early interferometric imaging measurements are reviewed, then more recent Thomson scatteringmore » measurements are discussed; these measurements provided the first direct evidence of ablation stream interpenetration in a wire array experiment. Combining the data from these experiments gives a view of the temporal evolution of the tungsten stream collisional dynamics. In the final part of the paper, we present new experimental measurements made using an imaging Faraday rotation diagnostic. These experiments investigated the structure of magnetic fields near the array axis directly; the presence of a magnetic field has previously been inferred based on Thomson scattering measurements of ion deflection near the array axis. Although the Thomson and Faraday measurements are not in full quantitative agreement, the Faraday data do qualitatively supports the conjecture that the observed deflections are induced by a static toroidal magnetic field, which has been advected to the array axis by the ablation streams. It is likely that detailed modeling will be needed in order to fully understand the dynamics observed in the experiment.« less

Ultrasonic friction power during Al wire wedge-wedge bonding

NASA Astrophysics Data System (ADS)

Shah, A.; Gaul, H.; Schneider-Ramelow, M.; Reichl, H.; Mayer, M.; Zhou, Y.

2009-07-01

Al wire bonding, also called ultrasonic wedge-wedge bonding, is a microwelding process used extensively in the microelectronics industry for interconnections to integrated circuits. The bonding wire used is a 25μm diameter AlSi1 wire. A friction power model is used to derive the ultrasonic friction power during Al wire bonding. Auxiliary measurements include the current delivered to the ultrasonic transducer, the vibration amplitude of the bonding tool tip in free air, and the ultrasonic force acting on the bonding pad during the bond process. The ultrasonic force measurement is like a signature of the bond as it allows for a detailed insight into mechanisms during various phases of the process. It is measured using piezoresistive force microsensors integrated close to the Al bonding pad (Al-Al process) on a custom made test chip. A clear break-off in the force signal is observed, which is followed by a relatively constant force for a short duration. A large second harmonic content is observed, describing a nonsymmetric deviation of the signal wave form from the sinusoidal shape. This deviation might be due to the reduced geometrical symmetry of the wedge tool. For bonds made with typical process parameters, several characteristic values used in the friction power model are determined. The ultrasonic compliance of the bonding system is 2.66μm/N. A typical maximum value of the relative interfacial amplitude of ultrasonic friction is at least 222nm. The maximum interfacial friction power is at least 11.5mW, which is only about 4.8% of the total electrical power delivered to the ultrasonic generator.

Imitation, Inspiration, and Creation: Cognitive Process of Creative Drawing by Copying Others' Artworks

ERIC Educational Resources Information Center

Okada, Takeshi; Ishibashi, Kentaro

2017-01-01

To investigate the cognitive processes underlying creative inspiration, we tested the extent to which viewing or copying prior examples impacted creative output in art. In Experiment 1, undergraduates made drawings under three conditions: (a) copying an artist's drawing, then producing an original drawing; (b) producing an original drawing without…

PEEK (polyether-ether-ketone)-coated nitinol wire: Film stability for biocompatibility applications

NASA Astrophysics Data System (ADS)

Sheiko, Nataliia; Kékicheff, Patrick; Marie, Pascal; Schmutz, Marc; Jacomine, Leandro; Perrin-Schmitt, Fabienne

2016-12-01

High quality biocompatible poly-ether-ether-ketone (PEEK) coatings were produced on NiTi shape memory alloy wires using dipping deposition from colloidal aqueous PEEK dispersions after substrate surface treatment. The surface morphology and microstructure were investigated by Scanning Electron Microscopy at every step of the process from the as-received Nitinol substrate to the ultimate PEEK-coated NiTi wire. Nanoscratch tests were carried out to access the adhesive behavior of the polymer coated film to the NiTi. The results indicate that the optimum process conditions in cleaning, chemical etching, and electropolishing the NiTi, were the most important and determining parameters to be achieved. Thus, high quality PEEK coatings were obtained on NiTi wires, straight or curved (even with a U-shape) with a homogeneous microstructure along the wire length and a uniform thickness of 12 μm without any development of cracks or the presence of large voids. The biocompatibility of the PEEK coating film was checked in fibrobast cultured cells. The coating remains stable in biological environment with negligible Ni ion release, no cytotoxicity, and no delamination observed with time.

Improvisation of mechanical and electrical properties of Cu by reinforcing MWCNT using modified electro-co-deposition process

NASA Astrophysics Data System (ADS)

Belgamwar, Sachin U.; Sharma, N. N.

2018-04-01

Multi-walled Carbon nanotubes–copper (MWCNT/Cu) composite powders with variable MWCNT content were synthesized by modified electro-co-deposition method. The electro-co-deposited MWCNT/Cu powders were consolidated by conventional compaction and sintering process. The consolidated products were then hot rolled and cold drawn to fine wires. The MWCNT/Cu composite wire samples were characterized for electrical and mechanical properties. We have been able to achieve an increase of around 8% in electrical conductivity of the form wires repeatedly. It has been observed that there was gradual improvement in the properties with reinforcement of MWCNT in the copper matrix. The betterment of electrical property has been achieved with simultaneous improvement in mechanical properties of the wire. The yield strength of MWCNT/Cu composite wire was found to be four times and the tensile strength two times greater than that of pure copper. The improved properties are attributed to the proper distribution of MWCNTs in the copper matrix and excellent interfacial bonding between MWCNT and composite copper fabricated by the modified method.

Shear bond strength of different retainer wires and bonding adhesives in consideration of the pretreatment process.

PubMed

Reicheneder, Claudia; Hofrichter, Bernd; Faltermeier, Andreas; Proff, Peter; Lippold, Carsten; Kirschneck, Christian

2014-11-28

We aimed to compare the shear bond strength (SBS) of three different retainer wires and three different bonding adhesives in consideration of the pretreatment process of enamel surface sandblasting. 400 extracted bovine incisors were divided into 10 groups of 20 paired specimens each. 10 specimens of each group were pretreated by enamel sandblasting. The retainer wires Bond-A-Braid™, GAC-Wildcat®-Twistflex and everStick®ORTHO were bonded to the teeth with the adhesives Transbond™-LR, Tetric-EvoFlow™ and Stick®FLOW and then debonded measuring the SBS. While sandblasting generally increased SBS for all tested combinations, the retainer wires bonded with Transbond™-LR showed the highest SBS both with and without prior sandblasting. Significantly lower SBS were found for Tetric-EvoFlow™ that were comparable to those for everStick®ORTHO. Pretreatment of enamel surfaces by sandblasting increased the SBS of all retainer-wires. Transbond™-LR showed the best results compared to Tetric-EvoFlow™ and everStick®ORTHO, while all combinations used provided sufficient bonding strengths for clinical use.

Progress in high performance DI-BSCCO wire

NASA Astrophysics Data System (ADS)

Kikuchi, M.; Ayai, N.; Fujikami, J.; Kobayashi, S.; Yamazaki, K.; Yamade, S.; Ishida, T.; Kato, T.; Hayashi, K.; Sato, K.; Hata, R.; Iihara, J.; Yamaguchi, K.; Kumakura, H.; Kitaguchi, H.; Osamura, K.; Shimoyama, J.

2008-03-01

The high performances of Dynamically Innovative BSCCO (DI-BSCCO) wire have been reviewed. Critical current (Ic) has reached 210 A (77 K and self-field), which is equivalent 500 A per 10 mm width, by total optimization of whole manufacturing process including Controlled Over Pressure (CT-OP) sintering. The further higher Ic value will be available on preferable oxide filaments with the improved c-axis orientation of Bi2223 grains, the minimized non-superconducting phases, and so on. The Ic of long length wires has been reached 203 A of 42 m 180 A of 1,400 m. Ic in the magnetic field at low temperature has showed great improvements in comparison with the past 150 A class wire. The mechanical performances has been improved due to the densification of the Bi2223 filaments up to 100% by CT-OP process, moreover have been dynamically improved by reinforcement with stainless steel tapes or brass tapes. These results can enable DI-BSCCO wire to be applied for the cryogenic applications such as motors, magnets, cables and so on.

Shot noise enhancement from non-equilibrium plasmons in Luttinger liquid junctions.

PubMed

Kim, Jaeuk U; Kinaret, Jari M; Choi, Mahn-Soo

2005-06-29

We consider a quantum wire double junction system with each wire segment described by a spinless Luttinger model, and study theoretically shot noise in this system in the sequential tunnelling regime. We find that the non-equilibrium plasmonic excitations in the central wire segment give rise to qualitatively different behaviour compared to the case with equilibrium plasmons. In particular, shot noise is greatly enhanced by them, and exceeds the Poisson limit. We show that the enhancement can be explained by the emergence of several current-carrying processes, and that the effect disappears if the channels effectively collapse to one because of fast plasmon relaxation processes, for example.

Studies of $${\\rm Nb}_{3}{\\rm Sn}$$ Strands Based on the Restacked-Rod Process for High Field Accelerator Magnets

DOE PAGES

Barzi, E.; Bossert, M.; Gallo, G.; ...

2011-12-21

A major thrust in Fermilab's accelerator magnet R&D program is the development of Nb 3Sn wires which meet target requirements for high field magnets, such as high critical current density, low effective filament size, and the capability to withstand the cabling process. The performance of a number of strands with 150/169 restack design produced by Oxford Superconducting Technology was studied for round and deformed wires. To optimize the maximum plastic strain, finite element modeling was also used as an aid in the design. Results of mechanical, transport and metallographic analyses are presented for round and deformed wires.

Shot noise enhancement from non-equilibrium plasmons in Luttinger liquid junctions

NASA Astrophysics Data System (ADS)

Kim, Jaeuk U.; Kinaret, Jari M.; Choi, Mahn-Soo

2005-06-01

We consider a quantum wire double junction system with each wire segment described by a spinless Luttinger model, and study theoretically shot noise in this system in the sequential tunnelling regime. We find that the non-equilibrium plasmonic excitations in the central wire segment give rise to qualitatively different behaviour compared to the case with equilibrium plasmons. In particular, shot noise is greatly enhanced by them, and exceeds the Poisson limit. We show that the enhancement can be explained by the emergence of several current-carrying processes, and that the effect disappears if the channels effectively collapse to one because of fast plasmon relaxation processes, for example.

Corrosion behavior and surface structure of orthodontic Ni-Ti alloy wires.

PubMed

Iijima, M; Endo, K; Ohno, H; Yonekura, Y; Mizoguchi, I

2001-03-01

The corrosion behaviors of a commercial Ni-Ti alloy orthodontic wire and a polished plate with same composition in 0.9% NaCl and 1% lactic acid solutions were examined using an electrochemical technique, an analysis of released ions, and a surface analysis by X-ray photoelectron spectroscopy (XPS). The effect of polishing the wire on the corrosion was also examined. The XPS analysis demonstrated the presence of a thick oxide film mainly composed of TiO2 with trace amounts of Ni hydroxide, which had formed on the wire surface during the heat treatment and subsequent pickling processes. This oxide layer contributed to the higher resistance of the as-received wire to both general and localized corrosion in 0.9% NaCl solution, compared with that of the polished plate and the polished wire. The thick oxide layer, however, was not stable and did not protect the orthodontic wire from corrosion in 0.1% lactic acid solution.

Numerical analysis of transient fields near thin-wire antennas and scatterers

NASA Astrophysics Data System (ADS)

Landt, J. A.

1981-11-01

Under the premise that `accelerated charge radiates,' one would expect radiation on wire structures to occur from driving points, ends of wires, bends in wires, or locations of lumped loading. Here, this premise is investigated in a series of numerical experiments. The numerical procedure is based on a moment-method solution of a thin-wire time-domain electric-field integral equation. The fields in the vicinity of wire structures are calculated for short impulsive-type excitations, and are viewed in a series of time sequences or snapshots. For these excitations, the fields are spatially limited in the radial dimension, and expand in spheres centered about points of radiation. These centers of radiation coincide with the above list of possible source regions. Time retardation permits these observations to be made clearly in the time domain, similar to time-range gating. In addition to providing insight into transient radiation processes, these studies show that the direction of energy flow is not always defined by Poynting's vector near wire structures.

Evaluating Thermally Damaged Polyimide Insulated Wiring (MIL-W-81381) with Ultrasound

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Anastasi, Robert F.

2002-01-01

A series of experiments to investigate the use of ultrasound for measuring wire insulation have been conducted. Initial laboratory tests were performed on MIL-W-81381/7,/12, and /21 aviation wire, a wire that has polyimide (Kapton Registered Trademark) layers for insulation. Samples of this wiring were exposed to 370C temperatures for different periods of time to induce a range of thermal damage. For each exposure, 12 samples of each gauge (12, 16, and 20 gauges) were processed. The velocity of the lowest order axisymmetric ultrasonic guided mode, a mode that is sensitive to the geometry and stiffness of the wire conductor and insulation, was measured. The phase velocity for the 20-gauge MIL-W-81381/7 wire had a baseline value of 3023 +/- 78 m/s. After exposure to the high temperatures, the wire's phase velocity rapidly increased, and reached an asymptotic value of 3598 +/- 20 m/s after 100 hours exposure. Similar behavior was measured for the 16 gauge MIL-W-81381/21 wire and 12 gauge MIL-W-81381/12 wire which had baseline values of 3225 +/- 22 m/s and 3403 +/- 33 m/s respectively, and reached asymptotic values of 3668 +/- 19 m/s, and 3679 +/- 42 m/s respectively. These measured velocity changes represent changes of 19, 14, and 8 percent respectively for the 20, 16, and 12 gauge wires. Finally, some results for a wire with an ethylene tetrafluoroethylene insulation are reported. Qualitatively similar behaviors are noted ultrasonically.

Composite Ceramic Superconducting Wires for Electric Motor Applications

DTIC Science & Technology

1989-07-07

generators that have been built using NbTi superconducting wire at liquid 3 helium temperature (4.2*K). Most of these magnets , motors, and generators have...temperature superconductors. A magnetic diffusivity value cannot be rigorously determined for the superconductor in the superconducting state when flux jump...cv, FIRST ANNUAL REPORT FOR THE PROJECT "COMPOSITE CERAMIC SUPERCONDUCTING WIRES FOR ELECTRIC MOTOR APPLICATIONS" 2 PRIME CONTRACTOR CERAMICS PROCESS

Monitoring Tensile Fatigue of Superelastic NiTi Wire in Liquids by Electrochemical Potential

NASA Astrophysics Data System (ADS)

Racek, Jan; Stora, Marc; Šittner, Petr; Heller, Luděk; Kopeček, Jaromir; Petrenec, Martin

2015-06-01

Fatigue of superelastic NiTi wires was investigated by cyclic tension in simulated biofluid. The state of the surface of the fatigued NiTi wire was monitored by following the evolution of the electrochemical open circuit potential (OCP) together with macroscopic stresses and strains. The ceramic TiO2 oxide layer on the NiTi wire surface cannot withstand the large transformation strain and fractures in the first cycle. Based on the analysis of the results of in situ OCP experiments and SEM observation of cracks, it is claimed that the cycled wire surface develops mechanochemical reactions at the NiTi/liquid interface leading to cumulative generation of hydrogen, uptake of the hydrogen by the NiTi matrix, local loss of the matrix strength, crack transfer into the NiTi matrix, accelerated crack growth, and ultimately to the brittle fracture of the wire. Fatigue degradation is thus claimed to originate from the mechanochemical processes occurring at the excessively deforming surface not from the accumulation of defects due to energy dissipative bulk deformation processes. Ironically, combination of the two exciting properties of NiTi—superelasticity due to martensitic transformation and biocompatibility due to the protective TiO2 surface oxide layer—leads to excessive fatigue damage during cyclic mechanical loading in biofluids.

Measurements of multi-scalar mixing in a turbulent coaxial jet

NASA Astrophysics Data System (ADS)

Hewes, Alais; Mydlarski, Laurent

2017-11-01

There are relatively few studies of turbulent multi-scalar mixing, despite the occurrence of this phenomenon in common processes (e.g. chemically reacting flows, oceanic mixing). In the present work, we simultaneously measure the evolution of two passive scalars (temperature and helium concentration) and velocity in a coaxial jet. Such a flow is particularly relevant, as coaxial jets are regularly employed in applications of turbulent non-premixed combustion, which relies on multi-scalar mixing. The coaxial jet used in the current experiment is based on the work of Cai et al. (J. Fluid Mech., 2011), and consists of a vertically oriented central jet of helium and air, surrounded by an annular flow of (unheated) pure air, emanating into a slow co-flow of (pure) heated air. The simultaneous two-scalar and velocity measurements are made using a 3-wire hot-wire anemometry probe. The first two wires of this probe form an interference (or Way-Libby) probe, and measure velocity and concentration. The third wire, a hot-wire operating at a low overheat ratio, measures temperature. The 3-wire probe is used to obtain concurrent velocity, concentration, and temperature statistics to characterize the mixing process by way of single and multivariable/joint statistics. Supported by the Natural Sciences and Engineering Research Council of Canada (Grant 217184).

A novel data reduction technique for single slanted hot-wire measurements used to study incompressible compressor tip leakage flows

NASA Astrophysics Data System (ADS)

Berdanier, Reid A.; Key, Nicole L.

2016-03-01

The single slanted hot-wire technique has been used extensively as a method for measuring three velocity components in turbomachinery applications. The cross-flow orientation of probes with respect to the mean flow in rotating machinery results in detrimental prong interference effects when using multi-wire probes. As a result, the single slanted hot-wire technique is often preferred. Typical data reduction techniques solve a set of nonlinear equations determined by curve fits to calibration data. A new method is proposed which utilizes a look-up table method applied to a simulated triple-wire sensor with application to turbomachinery environments having subsonic, incompressible flows. Specific discussion regarding corrections for temperature and density changes present in a multistage compressor application is included, and additional consideration is given to the experimental error which accompanies each data reduction process. Hot-wire data collected from a three-stage research compressor with two rotor tip clearances are used to compare the look-up table technique with the traditional nonlinear equation method. The look-up table approach yields velocity errors of less than 5 % for test conditions deviating by more than 20 °C from calibration conditions (on par with the nonlinear solver method), while requiring less than 10 % of the computational processing time.

Ultra-High Performance, High-Temperature Superconducting Wires via Cost-effective, Scalable, Co-evaporation Process

PubMed Central

Kim, Ho-Sup; Oh, Sang-Soo; Ha, Hong-Soo; Youm, Dojun; Moon, Seung-Hyun; Kim, Jung Ho; Dou, Shi Xue; Heo, Yoon-Uk; Wee, Sung-Hun; Goyal, Amit

2014-01-01

Long-length, high-temperature superconducting (HTS) wires capable of carrying high critical current, Ic, are required for a wide range of applications. Here, we report extremely high performance HTS wires based on 5 μm thick SmBa2Cu3O7 − δ (SmBCO) single layer films on textured metallic templates. SmBCO layer wires over 20 meters long were deposited by a cost-effective, scalable co-evaporation process using a batch-type drum in a dual chamber. All deposition parameters influencing the composition, phase, and texture of the films were optimized via a unique combinatorial method that is broadly applicable for co-evaporation of other promising complex materials containing several cations. Thick SmBCO layers deposited under optimized conditions exhibit excellent cube-on-cube epitaxy. Such excellent structural epitaxy over the entire thickness results in exceptionally high Ic performance, with average Ic over 1,000 A/cm-width for the entire 22 meter long wire and maximum Ic over 1,500 A/cm-width for a short 12 cm long tape. The Ic values reported in this work are the highest values ever reported from any lengths of cuprate-based HTS wire or conductor. PMID:24752189

Fabrication of Copper-Rich Cu-Al Alloy Using the Wire-Arc Additive Manufacturing Process

NASA Astrophysics Data System (ADS)

Dong, Bosheng; Pan, Zengxi; Shen, Chen; Ma, Yan; Li, Huijun

2017-12-01

An innovative wire-arc additive manufacturing (WAAM) process is used to fabricate Cu-9 at. pct Al on pure copper plates in situ, through separate feeding of pure Cu and Al wires into a molten pool, which is generated by the gas tungsten arc welding (GTAW) process. After overcoming several processing problems, such as opening the deposition molten pool on the extremely high-thermal conductive copper plate and conducting the Al wire into the molten pool with low feed speed, the copper-rich Cu-Al alloy was successfully produced with constant predesigned Al content above the dilution-affected area. Also, in order to homogenize the as-fabricated material and improve the mechanical properties, two further homogenization heat treatments at 1073 K (800 °C) and 1173 K (900 °C) were applied. The material and mechanical properties of as-fabricated and heat-treated samples were compared and analyzed in detail. With increased annealing temperatures, the content of precipitate phases decreased and the samples showed gradual improvements in both strength and ductility with little variation in microstructures. The present research opened a gate for in-situ fabrication of Cu-Al alloy with target chemical composition and full density using the additive manufacturing process.

A methodology to select a wire insulation for use in habitable spacecraft.

PubMed

Paulos, T; Apostolakis, G

1998-08-01

This paper investigates electrical overheating events aboard a habitable spacecraft. The wire insulation involved in these failures plays a major role in the entire event scenario from threat development to detection and damage assessment. Ideally, if models of wire overheating events in microgravity existed, the various wire insulations under consideration could be quantitatively compared. However, these models do not exist. In this paper, a methodology is developed that can be used to select a wire insulation that is best suited for use in a habitable spacecraft. The results of this study show that, based upon the Analytic Hierarchy Process and simplifying assumptions, the criteria selected, and data used in the analysis, Tefzel is better than Teflon for use in a habitable spacecraft.

Researching on Control Device of Prestressing Wire Reinforcement

NASA Astrophysics Data System (ADS)

Si, Jianhui; Guo, Yangbo; Liu, Maoshe

2017-06-01

This paper mainly introduces a device for controlling prestress and its related research methods, the advantage of this method is that the reinforcement process is easy to operate and control the prestress of wire rope accurately. The relationship between the stress and strain of the steel wire rope is monitored during the experiment, and the one - to - one relationship between the controllable position and the pretightening force of the steel wire rope is confirmed by the 5mm steel wire rope, and the results are analyzed theoretically by the measured elastic modulus. The results show that the method can effectively control the prestressing force, and the result provides a reference method for strengthening the concrete column with prestressed steel strand.

Ductile alloy and process for preparing composite superconducting wire

DOEpatents

Verhoeven, John D.; Finnemore, Douglas K.; Gibson, Edwin D.; Ostenson, Jerome E.

1983-03-29

An alloy for the commercial production of ductile superconducting wire is prepared by melting together copper and at least 15 weight percent niobium under non-oxygen-contaminating conditions, and rapidly cooling the melt to form a ductile composite consisting of discrete, randomly distributed and orientated dendritic-shaped particles of niobium in a copper matrix. As the wire is worked, the dendritric particles are realigned parallel to the longitudinal axis and when drawn form a plurality of very fine ductile superconductors in a ductile copper matrix. The drawn wire may be tin coated and wound into magnets or the like before diffusing the tin into the wire to react with the niobium. Impurities such as aluminum or gallium may be added to improve upper critical field characteristics.

Ductile alloy and process for preparing composite superconducting wire

DOEpatents

Verhoeven, J.D.; Finnemore, D.K.; Gibson, E.D.; Ostenson, J.E.

An alloy for the commercial production of ductile superconducting wire is prepared by melting together copper and at least 15 weight percent niobium under non-oxygen-contaminating conditions, and rapidly cooling the melt to form a ductile composite consisting of discrete, randomly distributed and oriented dendritic-shaped particles of niobium in a copper matrix. As the wire is worked, the dendritic particles are realigned parallel to the longitudinal axis and when drawn form a plurality of very fine ductile superconductors in a ductile copper matrix. The drawn wire may be tin coated and wound into magnets or the like before diffusing the tin into the wire to react with the niobium. Impurities such as aluminum or gallium may be added to improve upper critical field characteristics.

Far infrared polarizing grids for use at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Novak, Giles; Sundwall, Jeffrey L.; Pernic, Robert J.

1989-01-01

A technique is proposed for the construction of free-standing wire grids for use as far-IR polarizers. The method involves wrapping a strand of wire around a single cylinder rather than around a pair of parallel rods, thus simplifying the problem of maintaining constant wire tension. The cylinder is composed of three separate pieces which are disassembled at a later stage in the grid-making process. Grids have been constructed using 8-micron-diameter stainless steel wire and a grid spacing of 25 microns. The grids are shown to be reliable under repeated cycling between room temperature and 1.5 K.

High density harp for SSCL linac. [Suerconducting Super Collider Laboratory (SSCL)

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

Fritsche, C.T.; Krogh, M.L.; Crist, C.E.

1993-05-01

AlliedSignal Inc., Kansas City Division, and the Superconducting Super Collider Laboratory (SSCL) are collaboratively developing a high density harp for the SSCL linac. This harp is designed using hybrid microcircuit (HMC) technology to obtain a higher wire density than previously available. The developed harp contains one hundred twenty-eight 33-micron-diameter carbon wires on 0.38-mm centers. The harp features an onboard broken wire detection circuit. Carbon wire preparation and attachment processes were developed. High density surface mount connectors were located. The status of high density harp development will be presented along with planned future activities.

High density harp for SSCL linac

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

Fritsche, C.T.; Krogh, M.L.; Crist, C.E.

1993-05-01

AlliedSignal Inc., Kansas City Division, and the Superconducting Super Collider Laboratory (SSCL) are collaboratively developing a high density harp for the SSCL linac. This harp is designed using hybrid microcircuit (HMC) technology to obtain a higher wire density than previously available. The developed harp contains one hundred twenty-eight 33-micron-diameter carbon wires on 0.38-mm centers. The harp features an onboard broken wire detection circuit. Carbon wire preparation and attachment processes were developed. High density surface mount connectors were located. The status of high density harp development will be presented along with planned future activities.

Critical current densities of Jelly-Roll and powder metallurgy Nb{sub 3}Al wires as a function of temperature and magnetic field

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

Thieme, C.L.H.; Kim, J.B.; Takayasu, M.

Critical current densities of multi-filamentary Nb{sub 3}Al wire made with the Jelly-Roll process (JR) and mono-core powder metallurgy process (PM) wire were measured as a function of temperature and magnetic field. The temperature dependence of the resistive critical field B{sub c2} was measured in PM wires. There is a significant difference between these resistive B{sub c2} values and the ones determined by Kramer plots. The field dependence of the critical current depends on the manufacturing method. In general, it follows a relationship that falls between pure Kramer and one where the pinning force is inversely proportional with B{sup 2}. Inmore » contrast with Nb{sub 3}Sn no maximum in the bulk pinning force is observed down to 3 T (0.15MxB{sub c2}).« less

Role of research aircraft in technology development

NASA Technical Reports Server (NTRS)

Szalai, K. J.

1984-01-01

The United States's aeronautical research program has been rich in the use of research aircraft to explore new flight regimes, develop individual aeronautical concepts, and investigate new vehicle classes and configurations. This paper reviews the NASA supercritical wing, digital fly-by-wire, HiMAT, and AD-1 oblique-wing flight research programs, and draws from these examples general conclusions regarding the role and impact of research aircraft in technology development. The impact of a flight program on spinoff technology is also addressed. The secondary, serendipitous results are often highly significant. Finally, future research aircraft programs are examined for technology trends and expected results.

Method of sealing

DOEpatents

Groh, Edward F.; Cassidy, Dale A.

1978-01-01

A thermocouple lead or other small diameter wire, cable or tube is passed through a thin material such as sheet metal and sealed thereinto by drawing complementary longitudinally angled, laterally rounded grooves terminating at their base ends in a common plane in both sides of the thin material with shearing occuring at the deep end faces thereof to form a rounded opening in the thin material substantially perpendicular to the plane of the thin material, passing a thermocouple lead or similar object through the opening so formed and sealing the opening with a sealant which simultaneously bonds the lead to the thin material.

Design and implementation of a hot-wire probe for simultaneous velocity and vorticity vector measurements in boundary layers

NASA Astrophysics Data System (ADS)

Zimmerman, S.; Morrill-Winter, C.; Klewicki, J.

2017-10-01

A multi-sensor hot-wire probe for simultaneously measuring all three components of velocity and vorticity in boundary layers has been designed, fabricated and implemented in experiments up to large Reynolds numbers. The probe consists of eight hot-wires, compactly arranged in two pairs of orthogonal ×-wire arrays. The ×-wire sub-arrays are symmetrically configured such that the full velocity and vorticity vectors are resolved about a single central location. During its design phase, the capacity of this sensor to accurately measure each component of velocity and vorticity was first evaluated via a synthetic experiment in a set of well-resolved DNS fields. The synthetic experiments clarified probe geometry effects, allowed assessment of various processing schemes, and predicted the effects of finite wire length and wire separation on turbulence statistics. The probe was subsequently fabricated and employed in large Reynolds number experiments in the Flow Physics Facility wind tunnel at the University of New Hampshire. Comparisons of statistics from the actual probe with those from the simulated sensor exhibit very good agreement in trend, but with some differences in magnitude. These comparisons also reveal that the use of gradient information in processing the probe data can significantly improve the accuracy of the spanwise velocity measurement near the wall. To the authors' knowledge, the present are the largest Reynolds number laboratory-based measurements of all three vorticity components in boundary layers.

The magnetoresistance of sub-micron Fe wires

NASA Astrophysics Data System (ADS)

Blundell, S. J.; Shearwood, C.; Gester, M.; Baird, M. J.; Bland, J. A. C.; Ahmed, H.

1994-07-01

A novel combination of electron- and ion-beam lithography has been used to prepare Fe gratings with wire widths of 0.5 μm and wire separations in the range 0.5-4 μm from an Fe/GaAs (001) film of thickness 25 nm. With an in-plane magnetic field applied perpendicular to the length of the wires, a harder magnetisation loop is observed using the magneto-optic Kerr effect (MOKE), compared with that observed in the unprocessed film. We observe a strong effect in the magnetoresistance (MR) when the magnetic field is applied transverse to the wires. It is believed that this effect originates from the highly non-uniform demagnetising field in each wire of the grating. These results demonstrate that the combination of MOKE and MR measurements can provide important information about the magnetisation reversal processes in magnetic gratings and can be used to understand the effect of shape anisotropy on magnetic properties.

Metallic Glass Wire Based Localization of Kinesin/Microtubule Bio-molecular Motility System

NASA Astrophysics Data System (ADS)

Kim, K.; Sikora, A.; Yaginuma, S.; Nakayama, K. S.; Nakazawa, H.; Umetsu, M.; Hwang, W.; Teizer, W.

2014-03-01

We report electrophoretic accumulation of microtubules along metallic glass (Pd42.5Cu30Ni7.5P20) wires free-standing in solution. Microtubules are dynamic cytoskeletal filaments. Kinesin is a cytoskeletal motor protein. Functions of these bio-molecules are central to various dynamic cellular processes. Functional artificial organization of bio-molecules is a prerequisite for transferring their native functions into device applications. Fluorescence microscopy at the individual-microtubule level reveals microtubules aligning along the wire axis during the electrophoretic migration. Casein-treated electrodes are effective for releasing trapped microtubules upon removal of the external field. Furthermore, we demonstrate gliding motion of microtubules on kinesin-treated metallic glass wires. The reversible manner in the local adsorption of microtubules, the flexibility of wire electrodes, and the compatibility between the wire electrode and the bio-molecules are beneficial for spatio-temporal manipulation of the motility machinery in 3 dimensions.

Inverse Analysis to Formability Design in a Deep Drawing Process

NASA Astrophysics Data System (ADS)

Buranathiti, Thaweepat; Cao, Jian

Deep drawing process is an important process adding values to flat sheet metals in many industries. An important concern in the design of a deep drawing process generally is formability. This paper aims to present the connection between formability and inverse analysis (IA), which is a systematical means for determining an optimal blank configuration for a deep drawing process. In this paper, IA is presented and explored by using a commercial finite element software package. A number of numerical studies on the effect of blank configurations to the quality of a part produced by a deep drawing process were conducted and analyzed. The quality of the drawing processes is numerically analyzed by using an explicit incremental nonlinear finite element code. The minimum distance between elemental principal strains and the strain-based forming limit curve (FLC) is defined as tearing margin to be the key performance index (KPI) implying the quality of the part. The initial blank configuration has shown that it plays a highly important role in the quality of the product via the deep drawing process. In addition, it is observed that if a blank configuration is not greatly deviated from the one obtained from IA, the blank can still result a good product. The strain history around the bottom fillet of the part is also observed. The paper concludes that IA is an important part of the design methodology for deep drawing processes.

A real time dynamic data acquisition and processing system for velocity, density, and total temperature fluctuation measurements

NASA Technical Reports Server (NTRS)

Clukey, Steven J.

1991-01-01

The real time Dynamic Data Acquisition and Processing System (DDAPS) is described which provides the capability for the simultaneous measurement of velocity, density, and total temperature fluctuations. The system of hardware and software is described in context of the wind tunnel environment. The DDAPS replaces both a recording mechanism and a separate data processing system. DDAPS receives input from hot wire anemometers. Amplifiers and filters condition the signals with computer controlled modules. The analog signals are simultaneously digitized and digitally recorded on disk. Automatic acquisition collects necessary calibration and environment data. Hot wire sensitivities are generated and applied to the hot wire data to compute fluctuations. The presentation of the raw and processed data is accomplished on demand. The interface to DDAPS is described along with the internal mechanisms of DDAPS. A summary of operations relevant to the use of the DDAPS is also provided.

A Novel Multi-Charged Draw Solute That Removes Organic Arsenicals from Water in a Hybrid Membrane Process.

PubMed

Ge, Qingchun; Lau, Cher Hon; Liu, Minghua

2018-03-20

The potential of forward osmosis for water treatment can only be maximized with suitable draw solutes. Here a three-dimensional, multicharge draw solute of decasodium phytate (Na 10 -phytate) is designed and synthesized for removing organic arsenicals from water using a hybrid forward osmosis (FO) - membrane distillation (MD) process. Efficient water recovery is achieved using Na 10 -phytate as a draw solute with a water flux of 20.0 LMH and negligible reverse solute diffusion when 1000 ppm organic arsenicals as the feed and operated under ambient conditions with FO mode. At 50 °C, the novel draw solute increases water flux by more than 30% with water fluxes higher than 26.0 LMH on the FO side, drastically enhancing water recovery efficiency. By combining the FO and MD processes into a single hybrid process, a 100% recovery of Na 10 -phytate draw solute was achieved. Crucially, organic arsenicals or Na 10 -phytate draw solutes are both rejected 100% and not detected in the permeate of the hybrid process. The complete rejection of both organic arsenicals and draw solutes using hybrid membrane processes is unprecedented; creating a new application for membrane separations.

Attachment of Free Filament Thermocouples for Temperature Measurements on CMC

NASA Technical Reports Server (NTRS)

Lei, Jih-Fen; Cuy, Michael D.; Wnuk, Stephen P.

1997-01-01

Ceramic Matrix Composites (CMC) are being developed for use as enabling materials for advanced aeropropulsion engine and high speed civil transport applications. The characterization and testing of these advanced materials in hostile, high-temperature environments require accurate measurement of the material temperatures. Commonly used wire Thermo-Couples (TC) can not be attached to this ceramic based material via conventional spot-welding techniques. Attachment of wire TC's with commercially available ceramic cements fail to provide sufficient adhesion at high temperatures. While advanced thin film TC technology provides minimally intrusive surface temperature measurement and has good adhesion on the CMC, its fabrication requires sophisticated and expensive facilities and is very time consuming. In addition, the durability of lead wire attachments to both thin film TC's and the substrate materials requires further improvement. This paper presents a newly developed attachment technique for installation of free filament wire TC's with a unique convoluted design on ceramic based materials such as CMC's. Three CMC's (SiC/SiC CMC and alumina/alumina CMC) instrumented with type IC, R or S wire TC's were tested in a Mach 0.3 burner rig. The CMC temperatures measured from these wire TC's were compared to that from the facility pyrometer and thin film TC's. There was no sign of TC delamination even after several hours exposure to 1200 C. The test results proved that this new technique can successfully attach wire TC's on CMC's and provide temperature data in hostile environments. The sensor fabrication process is less expensive and requires very little time compared to that of the thin film TC's. The same installation technique/process can also be applied to attach lead wires for thin film sensor systems.

Influencing the arc and the mechanical properties of the weld metal in GMA-welding processes by additive elements on the wire electrode surface

NASA Astrophysics Data System (ADS)

Wesling, V.; Schram, A.; Müller, T.; Treutler, K.

2016-03-01

Under the premise of an increasing scarcity of raw materials and increasing demands on construction materials, the mechanical properties of steels and its joints are gaining highly important. In particular high- and highest-strength steels are getting in the focus of the research and the manufacturing industry. To the same extent, the requirements for filler metals are increasing as well. At present, these low-alloy materials are protected by a copper coating (<1μm) against corrosion. In addition, the coating realizes a good ohmic contact and good sliding properties between the welding machine and the wire during the welding process. By exchanging the copper with other elements it should be possible to change the mechanical properties of the weld metal and the arc stability during gas metal arc welding processes and keep the basic functions of the coating nearly untouched. On a laboratory scale solid wire electrodes with coatings of various elements and compounds such as titanium oxide were made and processed with a Gas Metal Arc Welding process. During the processing a different process behavior between the wire electrodes, coated and original, could be observed. The influences ranges from greater/shorter arc-length over increasing/decreasing droplets to larger/smaller arc foot point. Furthermore, the weld metal of the coated electrodes has significantly different mechanical and technological characteristics as the weld metal from the copper coated ground wire. The yield strength and tensile strength can be increased by up to 50%. In addition, the chemical composition of the weld metal was influenced by the application of coatings with layer thicknesses to 15 microns in the lower percentage range (up to about 3%). Another effect of the coating is a modified penetration. The normally occurring “argon finger” can be suppressed or enhanced by the choice of the coating. With the help of the presented studies it will be shown that Gas Metal Arc Welding processes are significantly affected by thin film coatings on solid wire electrodes for Gas Metal Arc welding. The influences are regarding the stability of the arc, the properties of the weld metal in terms of geometric expression, chemical composition and mechanical properties, the composition of the arc-plasma and the dynamics of the molten metal.

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

NASA Astrophysics Data System (ADS)

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.

A Full-Visible-Spectrum Invisibility Cloak for Mesoscopic Metal Wires.

PubMed

Kim, Sang-Woo; An, Byeong Wan; Cho, Eunjin; Hyun, Byung Gwan; Moon, Yoon-Jong; Kim, Sun-Kyung; Park, Jang-Ung

2018-06-13

Structured metals can sustain a very large scattering cross-section that is induced by localized surface plasmons, which often has an adverse effect on their use as transparent electrodes in displays, touch screens, and smart windows due to an issue of low clarity. Here, we report a broadband optical cloaking strategy for the network of mesoscopic metal wires with submicrometer to micrometer diameters, which is exploited for manufacturing and application of high-clarity metal-wires-based transparent electrodes. We prepare electrospun Ag wires with 300-1800 nm in diameter and perform a facile surface oxidation process to form Ag/Ag 2 O core/shell heterogeneous structures. The absorptive Ag 2 O shell, together with the coating of a dielectric cover, leads to the cancellation of electric multipole moments in Ag wires, thereby drastically suppressing plasmon-mediated scattering over the full visible spectrum and rendering Ag wires to be invisible. Simultaneously with the effect of invisibility, the transmittance of Ag/Ag 2 O wires is significantly improved compared to bare Ag wires, despite the formation of an absorptive Ag 2 O shell. As an application example, we demonstrate that these invisible Ag wires serve as a high-clarity, high-transmittance, and high-speed defroster for automotive windshields.

Corrosion of NiTi Wires with Cracked Oxide Layer

NASA Astrophysics Data System (ADS)

Racek, Jan; Šittner, Petr; Heller, Luděk; Pilch, Jan; Petrenec, Martin; Sedlák, Petr

2014-07-01

Corrosion behavior of superelastic NiTi shape memory alloy wires with cracked TiO2 surface oxide layers was investigated by electrochemical corrosion tests (Electrochemical Impedance Spectroscopy, Open Circuit Potential, and Potentiodynamic Polarization) on wires bent into U-shapes of various bending radii. Cracks within the oxide on the surface of the bent wires were observed by FIB-SEM and TEM methods. The density and width of the surface oxide cracks dramatically increase with decreasing bending radius. The results of electrochemical experiments consistently show that corrosion properties of NiTi wires with cracked oxide layers (static load keeps the cracks opened) are inferior compared to the corrosion properties of the straight NiTi wires covered by virgin uncracked oxides. Out of the three methods employed, the Electrochemical Impedance Spectroscopy seems to be the most appropriate test for the electrochemical characterization of the cracked oxide layers, since the impedance curves (Nyquist plot) of differently bent NiTi wires can be associated with increasing state of the surface cracking and since the NiTi wires are exposed to similar conditions as the surfaces of NiTi implants in human body. On the other hand, the potentiodynamic polarization test accelerates the corrosion processes and provides clear evidence that the corrosion resistance of bent superelastic NiTi wires degrades with oxide cracking.

Understanding Irreversible Degradation of Nb3Sn Wires with Fundamental Fracture Mechanics

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

Zhai, Yuhu; Calzolaio, Ciro; Senatore, Carmine

2014-08-01

Irreversible performance degradation of advanced Nb3Sn superconducting wires subjected to transverse or axial mechanical loading is a critical issue for the design of large-scale fusion and accelerator magnets such as ITER and LHC. Recent SULTAN tests indicate that most cable-in-conduit conductors for ITER coils made of Nb3Sn wires processed by various fabrication techniques show similar performance degradation under cyclic loading. The irreversible degradation due to filament fracture and local strain accumulation in Nb3Sn wires cannot be described by the existing strand scaling law. Fracture mechanic modeling combined with X-ray diffraction imaging of filament micro-crack formation inside the wires under mechanicalmore » loading may reveal exciting insights to the wire degradation mechanisms. We apply fundamental fracture mechanics with a singularity approach to study influence of wire filament microstructure of initial void size and distribution to local stress concentration and potential crack propagation. We report impact of the scale and density of the void structure on stress concentration in the composite wire materials for crack initiation. These initial defects result in an irreversible degradation of the critical current beyond certain applied stress. We also discuss options to minimize stress concentration in the design of the material microstructure for enhanced wire performance for future applications.« less

Methods for dispensing mercury into devices

DOEpatents

Grossman, Mark W.; George, William A.

1987-04-28

A process for dispensing mercury into devices which requires mercury. Mercury is first electrolytically separated from either HgO or Hg.sub.2 Cl.sub.2 and plated onto a cathode wire. The cathode wire is then placed into a device requiring mercury.

Dental Arch Wire

NASA Technical Reports Server (NTRS)

1979-01-01

Straightening teeth is an arduous process requiring months, often years, of applying corrective pressure by means of arch wires-better known as brace-which may have to be changed several times in the course of treatment. A new method has been developed by Dr. George Andreasen, orthodontist and dental scientist at the University of Iowa. The key is a new type of arch wire material, called Nitinol, with exceptional elasticity which helps reduce the required number of brace changes. An alloy of nickel and titanium, Nitinol was originally developed for aerospace applications by the Naval Ordnance Laboratory, now the Naval Surface Weapons Laboratory, White Oaks, Maryland. NASA subsequently conducted additional research on the properties of Nitinol and on procedures for processing the metal.

A tool for measuring the bending length in thin wires

NASA Astrophysics Data System (ADS)

Lorenzini, M.; Cagnoli, G.; Cesarini, E.; Losurdo, G.; Martelli, F.; Piergiovanni, F.; Vetrano, F.; Viceré, A.

2013-03-01

Great effort is currently being put into the development and construction of the second generation, advanced gravitational wave detectors, Advanced Virgo and Advanced LIGO. The development of new low thermal noise suspensions of mirrors, based on the experience gained in the previous experiments, is part of this task. Quasi-monolithic suspensions with fused silica wires avoid the problem of rubbing friction introduced by steel cradle arrangements by directly welding the wires to silica blocks bonded to the mirror. Moreover, the mechanical loss level introduced by silica (ϕfs ˜ 10-7 in thin fused silica wires) is by far less than the one associated with steel. The low frequency dynamical behaviour of the suspension can be computed and optimized, provided that the wire bending shape under pendulum motion is known. Due to the production process, fused silica wires are thicker near the two ends (necks), so that analytical bending computations are very complicated. We developed a tool to directly measure the low frequency bending parameters of fused silica wires, and we tested it on the wires produced for the Virgo+ monolithic suspensions. The working principle and a set of test measurements are presented and explained.

A tool for measuring the bending length in thin wires.

PubMed

Lorenzini, M; Cagnoli, G; Cesarini, E; Losurdo, G; Martelli, F; Piergiovanni, F; Vetrano, F; Viceré, A

2013-03-01

Great effort is currently being put into the development and construction of the second generation, advanced gravitational wave detectors, Advanced Virgo and Advanced LIGO. The development of new low thermal noise suspensions of mirrors, based on the experience gained in the previous experiments, is part of this task. Quasi-monolithic suspensions with fused silica wires avoid the problem of rubbing friction introduced by steel cradle arrangements by directly welding the wires to silica blocks bonded to the mirror. Moreover, the mechanical loss level introduced by silica (φfs ∼ 10(-7) in thin fused silica wires) is by far less than the one associated with steel. The low frequency dynamical behaviour of the suspension can be computed and optimized, provided that the wire bending shape under pendulum motion is known. Due to the production process, fused silica wires are thicker near the two ends (necks), so that analytical bending computations are very complicated. We developed a tool to directly measure the low frequency bending parameters of fused silica wires, and we tested it on the wires produced for the Virgo+ monolithic suspensions. The working principle and a set of test measurements are presented and explained.

KSC-08pd0078

NASA Image and Video Library

2008-01-23

KENNEDY SPACE CENTER, FLA. -- Quality inspectors with NASA and Lockheed Martin examine a red-line drawing of foam placement on space shuttle Atlantis's external tank (in front of them) to verify the foam insulation that was reapplied. The foam covers the feed-through engine cut-off, or ECO, sensor connector. The foam was removed to enable engineers to remove and replace the ECO sensor connector on the tank. The feed-through connector passes the wires from the inside of the tank to the outside. Results of a tanking test on Dec. 18 pointed to an open circuit in the feed-through connector wiring, which is located at the base of the tank. The pins in the replacement connector were precisely soldered to create a connection that allows sensors inside the tank to send signals to the computers onboard Atlantis. The repair work was done on Atlantis while the shuttle has been on Launch Pad 39A at NASA's Kennedy Space Center. The launch date for the shuttle's STS-122 mission has now been targeted for Feb. 7. Photo credit: NASA/Cory Husten

KSC-08pd0077

NASA Image and Video Library

2008-01-23

KENNEDY SPACE CENTER, FLA. -- Quality inspectors with NASA and Lockheed Martin examine a red-line drawing of foam placement on space shuttle Atlantis's external tank (in front of them) to verify the foam insulation that was reapplied. The foam covers the feed-through engine cut-off, or ECO, sensor connector. The foam was removed to enable engineers to remove and replace the ECO sensor connector on the tank. The feed-through connector passes the wires from the inside of the tank to the outside. Results of a tanking test on Dec. 18 pointed to an open circuit in the feed-through connector wiring, which is located at the base of the tank. The pins in the replacement connector were precisely soldered to create a connection that allows sensors inside the tank to send signals to the computers onboard Atlantis. The repair work was done on Atlantis while the shuttle has been on Launch Pad 39A at NASA's Kennedy Space Center. The launch date for the shuttle's STS-122 mission has now been targeted for Feb. 7. Photo credit: NASA/Cory Husten

KSC-08pd0080

NASA Image and Video Library

2008-01-23

KENNEDY SPACE CENTER, FLA. -- Quality inspectors with NASA and Lockheed Martin examine a red-line drawing of foam placement on space shuttle Atlantis's external tank (in front of them) to verify the foam insulation that was reapplied. The foam covers the feed-through engine cut-off, or ECO, sensor connector. The foam was removed to enable engineers to remove and replace the ECO sensor connector on the tank. The feed-through connector passes the wires from the inside of the tank to the outside. Results of a tanking test on Dec. 18 pointed to an open circuit in the feed-through connector wiring, which is located at the base of the tank. The pins in the replacement connector were precisely soldered to create a connection that allows sensors inside the tank to send signals to the computers onboard Atlantis. The repair work was done on Atlantis while the shuttle has been on Launch Pad 39A at NASA's Kennedy Space Center. The launch date for the shuttle's STS-122 mission has now been targeted for Feb. 7. Photo credit: NASA/Cory Husten

KSC-08pd0079

NASA Image and Video Library

2008-01-23

KENNEDY SPACE CENTER, FLA. -- Quality inspectors with NASA and Lockheed Martin examine a red-line drawing of foam placement on space shuttle Atlantis's external tank (in front of them) to verify the foam insulation that was reapplied. The foam covers the feed-through engine cut-off, or ECO, sensor connector. The foam was removed to enable engineers to remove and replace the ECO sensor connector on the tank. The feed-through connector passes the wires from the inside of the tank to the outside. Results of a tanking test on Dec. 18 pointed to an open circuit in the feed-through connector wiring, which is located at the base of the tank. The pins in the replacement connector were precisely soldered to create a connection that allows sensors inside the tank to send signals to the computers onboard Atlantis. The repair work was done on Atlantis while the shuttle has been on Launch Pad 39A at NASA's Kennedy Space Center. The launch date for the shuttle's STS-122 mission has now been targeted for Feb. 7. Photo credit: NASA/Cory Husten

Integration of gold-sputtered electrofluidic paper on wire-included analytical platforms for glucose biosensing.

PubMed

Núnez-Bajo, Estefanía; Carmen Blanco-López, M; Costa-García, Agustín; Teresa Fernández-Abedul, M

2017-05-15

This work describes the fabrication and evaluation of an electroanalytical paper-based platform based on the combination of both, reusable and disposable materials in order to generate simple, versatile and low-cost microfluidic devices. With this aim, a holder containing metal wires that act as reusable reference and counter electrodes has been developed. The gold-sputtered paper electrode is disposable and easily interchangeable, meanwhile the platform that includes reference and counter electrodes can be reused. The detection zone in the paper is delimited by drawing a hydrophobic line with an inexpensive permanent marker. The effect of experimental variables such as adding solutions through the face where the gold was sputtered (upwards) or through the opposite one (downwards) as well as of other working parameters were studied by cyclic and differential pulse voltammetry with potassium ferrocyanide as a common redox probe and indicator species for enzymatic, immune and DNA biosensing. Enzymatic determination of glucose in real food samples prove the feasibility of the developed system for the construction of electrochemical biosensors. Copyright © 2017 Elsevier B.V. All rights reserved.

High-performance MgB2 superconducting wires for use under liquid-helium-free conditions fabricated using an internal Mg diffusion process

NASA Astrophysics Data System (ADS)

Ye, ShuJun; Song, Minghui; Matsumoto, Akiyoshi; Togano, Kazumasa; Takeguchi, Masaki; Ohmura, Takahito; Kumakura, Hiroaki

2013-12-01

MgB2 has a superconducting transition temperature (Tc) of 39 K, which is much higher than that for practical metallic superconductors. Thus, it is hoped that MgB2 can not only replace metallic superconductors, but can be used under liquid-helium-free conditions, for example, at temperatures of 10-20 K that can easily be achieved using cryocooling systems. However, to date, the reported critical current density (Jc) for MgB2 wires is not high enough for large-scale applications in liquid-helium-free conditions. In the present study, successful fabrication of high-performance MgB2 superconducting wires was carried out using an internal Mg diffusion (IMD) process, involving a p-dimethylbenzene (C8H10) pre-treatment of carbon-coated B powder with nanometer-sized particles. The resulting wires exhibited the highest ever Jc of 1.2 × 105 A cm-2 at 4.2 K and 10 T, and an engineering critical current density (Je) of about 1 × 104 A cm-2. Not only in 4.2 K, but also in 10 K, the Jc values for the wires fabricated in the present study are in fact higher than that for Nb-Ti wires at 4.2 K for the magnetic fields at which the measurements were carried out. At 20 K and 5 T, the Jc and Je were about 7.6 × 105 A cm-2 and 5.3 × 103 A cm-2, respectively, which are the highest values reported for MgB2 wires to date. The results of a detailed microstructural analysis suggested that the main reason for the superior electrical performance was the high density of the MgB2 layer rather than just the small grain size, and that the critical current could be further increased by suitable control of the microstructure. These high-performance IMD-processed MgB2 wires are thus promising superconductors for applications such as magnetic resonance imaging and maglev trains that can operate under liquid-helium-free conditions.

The Integrity bare-metal stent made by continuous sinusoid technology.

PubMed

Turco, Mark A

2011-05-01

The Integrity Coronary Stent System (Medtronic Vascular, CA, USA) is a low-profile, open-cell, cobalt-chromium-alloy advanced bare-metal iteration of the well-known Driver/Micro-Driver Coronary Stent System (Medtronic Vascular). The Integrity stent is made with a process called continuous sinusoid technology. This process allows stent construction via wrapping a single thin strand of wire around a mandrel in a sinusoid configuration, with laser fusion of adjacent crowns. The wire-forming process and fusion pattern provide the stent with a continuous preferential bending plane, intended to allow easier access to, and smoother tracking within, distal and tortuous vessels while radial strength is maintained. Continuous sinusoid technology represents innovation in the design of stent platforms and will provide a future stent platform for newer technology, including drug-eluting stent platforms, drug-filled stents and core wire stents.

A-15 Superconducting composite wires and a method for making

DOEpatents

Suenaga, Masaki; Klamut, Carl J.; Luhman, Thomas S.

1984-01-01

A method for fabricating superconducting wires wherein a billet of copper containing filaments of niobium or vanadium is rolled to form a strip which is wrapped about a tin-alloy core to form a composite. The alloy is a tin-copper alloy for niobium filaments and a gallium-copper alloy for vanadium filaments. The composite is then drawn down to a desired wire size and heat treated. During the heat treatment process, the tin in the bronze reacts with the niobium to form the superconductor niobium tin. In the case where vanadium is used, the gallium in the gallium bronze reacts with the vanadium to form the superconductor vanadium gallium. This new process eliminates the costly annealing steps, external tin plating and drilling of bronze ingots required in a number of prior art processes.

Surface characteristics and damage distributions of diamond wire sawn wafers for silicon solar cells

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

Sopori, Bhushan; Devayajanam, Srinivas; Basnyat, Prakash

2016-01-01

This paper describes surface characteristics, in terms of its morphology, roughness and near-surface damage of Si wafers cut by diamond wire sawing (DWS) of Si ingots under different cutting conditions. Diamond wire sawn Si wafers exhibit nearly-periodic surface features of different spatial wavelengths, which correspond to kinematics of various movements during wafering, such as ingot feed, wire reciprocation, and wire snap. The surface damage occurs in the form of frozen-in dislocations, phase changes, and microcracks. The in-depth damage was determined by conventional methods such as TEM, SEM and angle-polishing/defect-etching. However, because these methods only provide local information, we have alsomore » applied a new technique that determines average damage depth over a large area. This technique uses sequential measurement of the minority carrier lifetime after etching thin layers from the surfaces. The lateral spatial damage variations, which seem to be mainly related to wire reciprocation process, were observed by photoluminescence and minority carrier lifetime mapping. Our results show a strong correlation of damage depth on the diamond grit size and wire usage.« less

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

NASA Astrophysics Data System (ADS)

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.

Nondestructive x-ray Scattering Characterization of High Temperature Superconducting Wires

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

Thurston, T R

The purpose of this CRADA was to characterize the structural properties of the superconductor material within the wires in order to determine which processing procedures produce the best superconductor texture and phase development, and hence the best ultimate current carrying capacity.

Manufacturing and quality control of interconnecting wire harnesses, Volume 2

NASA Technical Reports Server (NTRS)

1972-01-01

Interconnecting wire harnesses defined in the design standard are considered, including type 4, open bundle (not enclosed). Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into the document.

10. Photograph of a line drawing. 'PROCESS FLOW SCHEMATIC, GAS ...

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

10. Photograph of a line drawing. 'PROCESS FLOW SCHEMATIC, GAS PRODUCER PROCESS, BUILDING 10A.' Holston Army Ammunition Plant, Holston Defense Corporation. August 29, 1974. Delineator: G. A. Horne. Drawing # SK-1942. - Holston Army Ammunition Plant, Producer Gas Plant, Kingsport, Sullivan County, TN

The DAB model of drawing processes

NASA Technical Reports Server (NTRS)

Hochhaus, Larry W.

1989-01-01

The problem of automatic drawing was investigated in two ways. First, a DAB model of drawing processes was introduced. DAB stands for three types of knowledge hypothesized to support drawing abilities, namely, Drawing Knowledge, Assimilated Knowledge, and Base Knowledge. Speculation concerning the content and character of each of these subsystems of the drawing process is introduced and the overall adequacy of the model is evaluated. Second, eight experts were each asked to understand six engineering drawings and to think aloud while doing so. It is anticipated that a concurrent protocol analysis of these interviews can be carried out in the future. Meanwhile, a general description of the videotape database is provided. In conclusion, the DAB model was praised as a worthwhile first step toward solution of a difficult problem, but was considered by and large inadequate to the challenge of automatic drawing. Suggestions for improvements on the model were made.

One-step internal-tin Nb/sub 3/Sn superconductor fabrication. Final report, June 1983-August 1984

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

Marancik, W.

1985-03-01

The object of this research is to demonstrate the feasibility of producing a Nb/sub 3/Sn superconductor in a single extrusion process with a large number of filaments with internal tin. The technique chosen uses .010'-diameter Nb and tin-plated Cu wires formed into a solenoid. The solenoid is covered with tin-plated copper foil and isostatically compacted to a pressure of 17,000 psi. The solenoid is slit along its length. This results in a ribbon about 40 inches long by about 5-inches wide, with the Nb wires running across the 5-inch-width. The ribbon is then rolled up (Jelly Roll) around a 0.5more » inch diameter Ta covered copper rod to produce a composite of about 1.5 inches in diameter by 5 inches long. The composite geometry is now a cylindrical bundle of 0.010-inch-diameter Nb wire separated from each other by tin-plated copper. Each Nb wire is aligned with the axis of cylinder. The cylinder is slid into a Ta-lined copper extrusion can which is evacuated and sealed. The can is extruded at a low temperature and drawn to final wire size without intermediate annealing. The advantage of the process is that it is an internal tin process with the tin uniformly distributed through the matrix. The Nb is in a relatively soft state having been fully annealed at 0.020-inch diameter. Only one extrusion is required since the bundling technique allows a large number of wires to be precisely aligned and spaced in the matrix.« less

Novel Approach to Increase the Energy-related Process Efficiency and Performance of Laser Brazing

NASA Astrophysics Data System (ADS)

Mittelstädt, C.; Seefeld, T.; Radel, T.; Vollertsen, F.

Although laser brazing is well established, the energy-related efficiency of this joining method is quite low. That is because of low absorptivity of solid-state laser radiation, especially when copper base braze metals are used. Conventionally the laser beam is set close to the vertical axis and the filler wire is delivered under a flat angle. Therefore, the most of the utilized laser power is reflected and thus left unexploited. To address this situation an alternative processing concept for laser brazing, where the laser beam is leading the filler wire, has been investigated intending to make use of reflected shares of the laser radiation. Process monitoring shows, that the reflection of the laser beam can be used purposefully to preheat the substrate which is supporting the wetting and furthermore increasing the efficiency of the process. Experiments address a standard application from the automotive industry joining zinc coated steels using CuSi3Mn1 filler wire. Feasibility of the alternative processing concept is demonstrated, showing that higher processing speeds can be attained, reducing the required energy per unit length while maintaining joint properties.

Customized Hermetic Feedthrough Developed to Isolate Fluids

NASA Technical Reports Server (NTRS)

Meredith, Roger D.

1999-01-01

A common problem occurs when refrigerant fluids wick inside the insulation of thermocouple wires through a compressor's casing feedthrough and then leak into the adjacent disconnect box outside the casing. Leaking fluids create an unfavorable situation inside the disconnect box and may contaminate the fluids. To address this problem, NASA Lewis Research Center s Manufacturing Engineering Division developed a customized hermetic feedthrough for a bank of Worthington compressors. In these compressors, bearing temperatures are measured by internal thermocouples embedded in bearings located inside the compressor casings. The thermocouple wires need to be routed outside the casing and read at another location. These wires are short and are terminated to a disconnect strip inside the casing. The bearings operate at about 170 F, but because the casing is filled with R12 refrigerant oil, the casing has a maximum temperature of about 100 F. The operating conditions of these compressors permit the use of an epoxy that is compatible with the R12 fluid. The desired finished product is a stainless steel tube that has been filled solid with epoxy after thermocouple wires bonded and sealed by epoxy have been inserted through its length. Shrink tubing extends from both ends of the tube. The process that was developed to isolate the thermocouple wires from the R12 fluid follows. For this application, use an 8-in.-long piece of 0.500-in. 304 stainless steel tube with six pairs of 24-gauge stranded, PTFE-insulated (polytetrafluoroethylene) type "T" thermocouple wires for each feedthrough. Use shrink tubing to strain relief the insulated wires at their exit from the stainless steel tube. Cut the wire to length and identify the location of the stainless steel tube sleeve with masking tape. Then, remove the outer insulation from a 2-in. section of wire that will be inside the tube, and carefully strip to bare wire a 1-in. section in the middle of the section with the outer insulation removed. For an effective seal, the epoxy must penetrate between the strands when stranded conductors are used. Make the seal with epoxy bond on the bare wire. The bare wire must be encapsulated with a thin layer of the epoxy that leaves only a very low profile. These encapsulated wires must cure before the assembly can be continued. Then, inspect the cured wires for complete encapsulation before going to the next step. Insert the wires in the stainless steel tube and orient them so that the epoxied stripped sections are staggered within the tube; then, apply shrink tubing to one end of the cleaned wires, positioning it inside the edge of the tube. The small gaps between the wires on the other end will be used to inject the epoxy into the tube. Let the epoxy cure inside the tube, free of any voids. Then, continue to fill the tube until the entire 8-in. length is nearly filled, allowing room for the other strain-relieving shrink tubing. Since this first design, the process has been adjusted to fit many needs and situations. Customized feedthroughs have been assembled from various wire types, wire gauges, and/or stainless steel tube passages. The fittings selected to mount these feedthroughs allow their use in other areas, such as pressure or vacuum systems.

Combined effects of different heat treatments and Cu element on transformation behavior of NiTi orthodontic wires.

PubMed

Seyyed Aghamiri, S M; Ahmadabadi, M Nili; Raygan, Sh

2011-04-01

The shape memory nickel-titanium alloy has been applied in many fields due to its unique thermal and mechanical performance. One of the successful applications of NiTi wires is in orthodontics because of its good characteristics such as low stiffness, high spring back, high stored energy, biocompatibility, superelasticity and shape memory effect. The mechanical properties of wires are paid special attention which results in achieving continuous optimal forces and eventually causing rapid tooth movement without any damage. The behavior of the alloy can be controlled by chemical composition and thermo-mechanical treatment during the manufacturing process. In this study two kinds of commercial superelastic NiTi archwires of 0.41 mm diameter were investigated: Copper NiTi and Highland Metal. The chemical analysis of both wires was estimated by energy dispersive spectroscopy (EDS). It was showed that Copper NiTi wire contained copper and chromium. The two types of wires were exposed to different heat treatment conditions at 400 and 500 °C for 10 and 60 min to compare the behavior of the wires at aged and as-received conditions. Phase transformation temperatures clarified by differential scanning calorimetry (DSC) showed B2 <--> R <--> B19 transformation in Highland Metal wire and B2 <--> B19(') transformation in Copper NiTi wire. Three point bending (TPB) tests in the certain designed fixture were performed at 37 °C to evaluate the mechanical behavior of the wires. The experimental results revealed the superelastic behavior of the Highland Metal wire after 60 min ageing at 400 and 500 °C and the plastic deformation of the Copper NiTi wire after annealing due to the effect of copper in the alloy composition. Copyright © 2010 Elsevier Ltd. All rights reserved.

Analytical and regression models of glass rod drawing process

NASA Astrophysics Data System (ADS)

Alekseeva, L. B.

2018-03-01

The process of drawing glass rods (light guides) is being studied. The parameters of the process affecting the quality of the light guide have been determined. To solve the problem, mathematical models based on general equations of continuum mechanics are used. The conditions for the stable flow of the drawing process have been found, which are determined by the stability of the motion of the glass mass in the formation zone to small uncontrolled perturbations. The sensitivity of the formation zone to perturbations of the drawing speed and viscosity is estimated. Experimental models of the drawing process, based on the regression analysis methods, have been obtained. These models make it possible to customize a specific production process to obtain light guides of the required quality. They allow one to find the optimum combination of process parameters in the chosen area and to determine the required accuracy of maintaining them at a specified level.

Preferential sites for InAsP/InP quantum wire nucleation using molecular dynamics

NASA Astrophysics Data System (ADS)

Nuñez-Moraleda, Bernardo; Pizarro, Joaquin; Guerrero, Elisa; Guerrero-Lebrero, Maria P.; Yáñez, Andres; Molina, Sergio Ignacio; Galindo, Pedro Luis

2014-11-01

In this paper, stress fields at the surface of the capping layer of self-assembled InAsP quantum wires grown on an InP (001) substrate have been determined from atomistic models using molecular dynamics and Stillinger-Weber potentials. To carry out these calculations, the quantum wire compositional distribution was extracted from previous works, where the As and P distributions were determined by electron energy loss spectroscopy and high-resolution aberration-corrected Z-contrast imaging. Preferential sites for the nucleation of wires on the surface of the capping layer were studied and compared with (i) previous simulations using finite element analysis to solve anisotropic elastic theory equations and (ii) experimentally measured locations of stacked wires. Preferential nucleation sites of stacked wires were determined by the maximum stress location at the MD model surface in good agreement with experimental results and those derived from finite element analysis. This indicates that MD simulations based on empirical potentials provide a suitable and flexible tool to study strain dependent atom processes.

Fabrication and properties of multifilamentary MgB 2 wires by in-situ powder-in-tube process

NASA Astrophysics Data System (ADS)

Wang, Q. Y.; Jiao, G. F.; Liu, G. Q.; Xiong, X. M.; Yan, S. C.; Zhang, P. X.; Sulpice, A.; Mossang, E.; Feng, Y.; Yan, G.

2010-11-01

We have fabricated the long TiC-doped MgB2 wires with 6 filaments by in-situ powder-in-tube method using Nb as the barrier and copper as the stabilizer. To improve the strength of wires, the Nb-core was used as the central filament. The transport engineering critical current density (Jce) of the samples sintered at different temperature were measured, which reaches 2.5 × 104 A/cm2 at 4.2 K, 5 T. 100 m MgB2 wires with different diameter were wound into coils and the transport critical current (Ic) of the coil were measured at 30 K in self-field. The Jce value 100 m coil achieves 1.1 × 104 A/cm2 in 1.2 mm wire. The reasons leading to the enhancement of high field Jce were discussed. The results show a good potential to fabricate high performance MgB2 wires and tapes at ambient pressure on an industrial scale.

Development of automatic through-insulation welding for microelectric interconnections

NASA Technical Reports Server (NTRS)

Arnett, J. C.

1972-01-01

The capability to automatically route, remove insulation from, and weld small-diameter solid conductor wire is presented. This would facilitate the economical small-quantity production of complex miniature electronic assemblies. An engineering model of equipment having this capability was developed and evaluated. Whereas early work in the use of welded magnet wire interconnections was concentrated on opposed electrode systems, and generally used heat to melt the wire insulation, the present method is based on a concentric electrode system and a wire feed system which splits the insulation by application of pressure prior to welding. The work deals with the design, fabrication, and evaluation testing of an improved version of this concentric electrode system. Two different approaches to feeding the wire to the concentric electrodes were investigated. It was concluded that the process is feasible for the interconnection of complex miniature electronic assemblies.

Applying a punch with microridges in multistage deep drawing processes.

PubMed

Lin, Bor-Tsuen; Yang, Cheng-Yu

2016-01-01

The developers of high aspect ratio components aim to minimize the processing stages in deep drawing processes. This study elucidates the application of microridge punches in multistage deep drawing processes. A microridge punch improves drawing performance, thereby reducing the number of stages required in deep forming processes. As an example, the original eight-stage deep forming process for a copper cylindrical cup with a high aspect ratio was analyzed by finite element simulation. Microridge punch designs were introduced in Stages 4 and 7 to replace the original punches. In addition, Stages 3 and 6 were eliminated. Finally, these changes were verified through experiments. The results showed that the microridge punches reduced the number of deep drawing stages yielding similar thickness difference percentages. Further, the numerical and experimental results demonstrated good consistency in the thickness distribution.

Body of Knowledge (BOK) for Copper Wire Bonds

NASA Technical Reports Server (NTRS)

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. An evaluation of copper wire bond technology for applicability to spaceflight hardware may be warranted along with concurrently compiling a comprehensive understanding of the failure mechanisms involved with copper wire bonded semiconductor devices.

AIR EMISSIONS FROM LASER DRILLING OF PRINTED WIRING BOARD MATERIALS

EPA Science Inventory

The paper gives results of a study to characterize gases generated during laser drilling of printed wiring board (PWB) material and identifies the pollutants and generation rates found during the drilling process. Typically found in the missions stream were trace amounts of carbo...

Methods for dispensing mercury into devices

DOEpatents

Grossman, M.W.; George, W.A.

1987-04-28

A process is described for dispensing mercury into devices which requires mercury. Mercury is first electrolytically separated from either HgO or Hg[sub 2]Cl[sub 2] and plated onto a cathode wire. The cathode wire is then placed into a device requiring mercury. 2 figs.

Wired vs. Wireless.

ERIC Educational Resources Information Center

Fielding, Randall

2000-01-01

Presents a debate on which technology will be in tomorrow's classrooms and the pros and cons of wiring classrooms and using a wireless network. Concluding comments address the likelihood, and desirability, of placing computers throughout the entire educational process and what types of computers and capabilities are needed. (GR)

Ionization Electron Signal Processing in Single Phase LArTPCs I. Algorithm Description and Quantitative Evaluation with MicroBooNE Simulation

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

Adams, C.; et al.

We describe the concept and procedure of drifted-charge extraction developed in the MicroBooNE experiment, a single-phase liquid argon time projection chamber (LArTPC). This technique converts the raw digitized TPC waveform to the number of ionization electrons passing through a wire plane at a given time. A robust recovery of the number of ionization electrons from both induction and collection anode wire planes will augment the 3D reconstruction, and is particularly important for tomographic reconstruction algorithms. A number of building blocks of the overall procedure are described. The performance of the signal processing is quantitatively evaluated by comparing extracted charge withmore » the true charge through a detailed TPC detector simulation taking into account position-dependent induced current inside a single wire region and across multiple wires. Some areas for further improvement of the performance of the charge extraction procedure are also discussed.« less

Wired to freedom: Life science, public politics, and the case of Cochlear Implantation.

PubMed

Jepsen, Kim Sune; Bertilsson, T Margareta

2017-02-01

Cochlear Implantation is now regarded as the most successful medical technology. It carries promises to provide deaf/hearing impaired individuals with a technological sense of hearing and an access to participate on a more equal level in social life. In this article, we explore the adoption 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 Implantation. As our empirical observations are largely based in the Scandinavian countries (notably Denmark), we also provide some reflections on the character of the technology-friendly Scandinavian welfare states and the unintended consequences that may follow in the wake of rapid technology implementation of life science in society.

A Fundamental Study of Stretch-Drawing Process of Sheet Metals : Single and Double Operations

NASA Astrophysics Data System (ADS)

Gotoh, Manabu; Kim, Young-soo; Yamashita, Minoru

1998-05-01

Fundamental and informative data of axisymmetric stretch-drawing of several sheet metals with thichness of 0.7 1.0 mm are presented especially for single and double operations. Very small radius is applied to the die-profile (or -shoulder) in all operations to induce wall-thinning by the effect of bending-under-tension, from which the name `stretch-drawing' comes. It is clearly demonstrated that deeper cups could be formed by the single and double stretch-drawings from smaller cirlcular blanks due to such wall-thinning action than in the usual deep-drawing of larger blanks. From this fact, it is emphasized that the deep-drawability of a sheet metal is not evaluated simply by the conventional LDR (=limiting drawing ratio), but the depth of the drawn cup should also be taken into account. Many experimental data about various metals and thicknesses given in this paper offer a valueable information on this process for more general use which recommends to replace the conventional deep-drawing process by the stretch-drawing process both for single and double operations. In the single stretch-drawing, it is also confirmed that a deeper cup can be produced by raising the blank-holding force at later stage of operation. Fracturing is found to occur at the middle section of the wall part or at the die-profile other than at the punch profile common in the usual deep-drawing process. Numerical simulation of the single stretch-drawing process is also performed by use of DYNA-3D code to confirm that a satisfactory prediction especially in the depth of the drawn-cup can be done at least in a practical sense, although this kind of numerical analysis is very difficult because of the severity or localization of deformation around the die profile. The drawn cup of SUS304 among others fractures in a couple of weeks after the operation due to the residual circumferential tensile stress, whereas that of SUS304L does not. In the double stretch-drawing, it is confirmed that very deeper cups can be produced when compared to the usual re-drawing process, which assures typically the usefulness of this operation as a practical process. Fracture often takes place circumferentially or, very peculiarly, even in a spiral mode for SUS304 at the middle of the wall part of the cup.

Minimum depth of investigation for grounded-wire TEM due to self-transients

NASA Astrophysics Data System (ADS)

Zhou, Nannan; Xue, Guoqiang

2018-05-01

The grounded-wire transient electromagnetic method (TEM) has been widely used for near-surface metalliferous prospecting, oil and gas exploration, and hydrogeological surveying in the subsurface. However, it is commonly observed that such TEM signal is contaminated by the self-transient process occurred at the early stage of data acquisition. Correspondingly, there exists a minimum depth of investigation, above which the observed signal is not applicable for reliable data processing and interpretation. Therefore, for achieving a more comprehensive understanding of the TEM method, it is necessary to perform research on the self-transient process and moreover develop an approach for quantifying the minimum detection depth. In this paper, we first analyze the temporal procedure of the equivalent circuit of the TEM method and present a theoretical equation for estimating the self-induction voltage based on the inductor of the transmitting wire. Then, numerical modeling is applied for building the relationship between the minimum depth of investigation and various properties, including resistivity of the earth, offset, and source length. It is guide for the design of survey parameters when the grounded-wire TEM is applied to the shallow detection. Finally, it is verified through applications to a coal field in China.

Annular beam shaping system for advanced 3D laser brazing

NASA Astrophysics Data System (ADS)

Pütsch, Oliver; Stollenwerk, Jochen; Kogel-Hollacher, Markus; Traub, Martin

2012-10-01

As laser brazing benefits from advantages such as smooth joints and small heat-affected zones, it has become established as a joining technology that is widely used in the automotive industry. With the processing of complex-shaped geometries, recent developed brazing heads suffer, however, from the need for continuous reorientation of the optical system and/or limited accessibility due to lateral wire feeding. This motivates the development of a laser brazing head with coaxial wire feeding and enhanced functionality. An optical system is designed that allows to generate an annular intensity distribution in the working zone. The utilization of complex optical components avoids obscuration of the optical path by the wire feeding. The new design overcomes the disadvantages of the state-of-the-art brazing heads with lateral wire feeding and benefits from the independence of direction while processing complex geometries. To increase the robustness of the brazing process, the beam path also includes a seam tracking system, leading to a more challenging design of the whole optical train. This paper mainly discusses the concept and the optical design of the coaxial brazing head, and also presents the results obtained with a prototype and selected application results.

Markovian and non-Markovian light-emission channels in strained quantum wires.

PubMed

Lopez-Richard, V; González, J C; Matinaga, F M; Trallero-Giner, C; Ribeiro, E; Sousa Dias, M Rebello; Villegas-Lelovsky, L; Marques, G E

2009-09-01

We have achieved conditions to obtain optical memory effects in semiconductor nanostructures. The system is based on strained InP quantum wires where the tuning of the heavy-light valence band splitting has allowed the existence of two independent optical channels with correlated and uncorrelated excitation and light-emission processes. The presence of an optical channel that preserves the excitation memory is unambiguously corroborated by photoluminescence measurements of free-standing quantum wires under different configurations of the incoming and outgoing light polarizations in various samples. High-resolution transmission electron microscopy and electron diffraction indicate the presence of strain effects in the optical response. By using this effect and under certain growth conditions, we have shown that the optical recombination is mediated by relaxation processes with different natures: one a Markov and another with a non-Markovian signature. Resonance intersubband light-heavy hole transitions assisted by optical phonons provide the desired mechanism for the correlated non-Markovian carrier relaxation process. A multiband calculation for strained InP quantum wires was developed to account for the description of the character of the valence band states and gives quantitative support for light hole-heavy hole transitions assisted by optical phonons.

Cyclic Fatigue Resistance of Novel Rotary Files Manufactured from Different Thermal Treated Nickel-Titanium Wires in Artificial Canals.

PubMed

Karataşlıoglu, E; Aydın, U; Yıldırım, C

2018-02-01

The aim of this in vitro study was to compare the static cyclic fatigue resistance of thermal treated rotary files with a conventional nickel-titanium (NiTi) rotary file. Four groups of 60 rotary files with similar file dimensions, geometries, and motion were selected. Groups were set as HyFlex Group [controlled memory wire (CM-Wire)], ProfileVortex Group (M-Wire), Twisted File Group (R-Phase Wire), and OneShape Group (conventional NiTi wire)] and tested using a custom-made static cyclic fatigue testing apparatus. The fracture time and fragment length of the each file was also recorded. Statistical analysis was performed using one-way analysis of variance and Tukey's test at the 95% confidence level (P = 0.05). The HyFlex group had a significantly higher mean cyclic fatigue resistance than the other three groups (P < 0.001). The OneShape groups had the least fatigue resistance. CM-Wire alloy represented the best performance in cyclic fatigue resistance, and NiTi alloy in R-Phase had the second highest fatigue resistance. CM and R-Phase manufacturing technology processed to the conventional NiTi alloy enhance the cyclic fatigue resistance of files that have similar design and size. M-wire alloy did not show any superiority in cyclic fatigue resistance when compared with conventional NiTi wire.

Imitation, Inspiration, and Creation: Cognitive Process of Creative Drawing by Copying Others' Artworks.

PubMed

Okada, Takeshi; Ishibashi, Kentaro

2017-09-01

To investigate the cognitive processes underlying creative inspiration, we tested the extent to which viewing or copying prior examples impacted creative output in art. In Experiment 1, undergraduates made drawings under three conditions: (a) copying an artist's drawing, then producing an original drawing; (b) producing an original drawing without having seen another's work; and (c) copying another artist's work, then reproducing that artist's style independently. We discovered that through copying unfamiliar abstract drawings, participants were able to produce creative drawings qualitatively different from the model drawings. Process analyses suggested that participants' cognitive constraints became relaxed, and new perspectives were formed from copying another's artwork. Experiment 2 showed that exposure to styles of artwork considered unfamiliar facilitated creativity in drawing, while styles considered familiar did not do so. Experiment 3 showed that both copying and thoroughly viewing artwork executed using an unfamiliar style facilitated creativity in drawing, whereas merely thinking about alternative styles of artistic representation did not do so. These experiments revealed that deep encounters with unfamiliar artworks-whether through copying or prolonged observation-change people's cognitive representations of the act of drawing to produce novel artwork. Copyright © 2016 Cognitive Science Society, Inc.

Optimisation of wire-cut EDM process parameter by Grey-based response surface methodology

NASA Astrophysics Data System (ADS)

Kumar, Amit; Soota, Tarun; Kumar, Jitendra

2018-03-01

Wire electric discharge machining (WEDM) is one of the advanced machining processes. Response surface methodology coupled with Grey relation analysis method has been proposed and used to optimise the machining parameters of WEDM. A face centred cubic design is used for conducting experiments on high speed steel (HSS) M2 grade workpiece material. The regression model of significant factors such as pulse-on time, pulse-off time, peak current, and wire feed is considered for optimising the responses variables material removal rate (MRR), surface roughness and Kerf width. The optimal condition of the machining parameter was obtained using the Grey relation grade. ANOVA is applied to determine significance of the input parameters for optimising the Grey relation grade.

The insulation of copper wire by the electrostatic coating process

NASA Astrophysics Data System (ADS)

Wells, M. G. H.

1983-06-01

A review of the fluidized bed electrostatic coating process and materials available for application to flat copper conductor has been made. Lengths of wire were rolled and electrostatically coated with two epoxy insulations. Electrical tests were made in air on coated samples at room and elevated temperatures. Compatibility tests in the cooling/lubricating turbine oil at temperatures up to 220 deg. C were also made. Recommendations for additional work are provided.

A method for identifying EMI critical circuits during development of a large C3

NASA Astrophysics Data System (ADS)

Barr, Douglas H.

The circuit analysis methods and process Boeing Aerospace used on a large, ground-based military command, control, and communications (C3) system are described. This analysis was designed to help identify electromagnetic interference (EMI) critical circuits. The methodology used the MIL-E-6051 equipment criticality categories as the basis for defining critical circuits, relational database technology to help sort through and account for all of the approximately 5000 system signal cables, and Macintosh Plus personal computers to predict critical circuits based on safety margin analysis. The EMI circuit analysis process systematically examined all system circuits to identify which ones were likely to be EMI critical. The process used two separate, sequential safety margin analyses to identify critical circuits (conservative safety margin analysis, and detailed safety margin analysis). These analyses used field-to-wire and wire-to-wire coupling models using both worst-case and detailed circuit parameters (physical and electrical) to predict circuit safety margins. This process identified the predicted critical circuits that could then be verified by test.

Organization of the Drosophila larval visual circuit

PubMed Central

Gendre, Nanae; Neagu-Maier, G Larisa; Fetter, Richard D; Schneider-Mizell, Casey M; Truman, James W; Zlatic, Marta; Cardona, Albert

2017-01-01

Visual systems transduce, process and transmit light-dependent environmental cues. Computation of visual features depends on photoreceptor neuron types (PR) present, organization of the eye and wiring of the underlying neural circuit. Here, we describe the circuit architecture of the visual system of Drosophila larvae by mapping the synaptic wiring diagram and neurotransmitters. By contacting different targets, the two larval PR-subtypes create two converging pathways potentially underlying the computation of ambient light intensity and temporal light changes already within this first visual processing center. Locally processed visual information then signals via dedicated projection interneurons to higher brain areas including the lateral horn and mushroom body. The stratified structure of the larval optic neuropil (LON) suggests common organizational principles with the adult fly and vertebrate visual systems. The complete synaptic wiring diagram of the LON paves the way to understanding how circuits with reduced numerical complexity control wide ranges of behaviors.

Design of power cable grounding wire anti-theft monitoring system

NASA Astrophysics Data System (ADS)

An, Xisheng; Lu, Peng; Wei, Niansheng; Hong, Gang

2018-01-01

In order to prevent the serious consequences of the power grid failure caused by the power cable grounding wire theft, this paper presents a GPRS based power cable grounding wire anti-theft monitoring device system, which includes a camera module, a sensor module, a micro processing system module, and a data monitoring center module, a mobile terminal module. Our design utilize two kinds of methods for detecting and reporting comprehensive image, it can effectively solve the problem of power and cable grounding wire box theft problem, timely follow-up grounded cable theft events, prevent the occurrence of electric field of high voltage transmission line fault, improve the reliability of the safe operation of power grid.

MRI-guided Wire Localization Surgical Biopsy in an Adolescent Patient with a Difficult to Diagnose Case of Lymphoma

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

Thompson, Scott M., E-mail: Thompson.scott@mayo.edu; Gorny, Krzysztof R.; Jondal, Danielle E.

A 17-year-old previously healthy female presented with a progressive soft tissue infiltrative process involving the neck and thorax. Extensive diagnostic evaluation including multiple imaging, laboratory, and biopsy studies was nondiagnostic. Due to an urgent need to establish a diagnosis and several previous nondiagnostic biopsies, she was referred to interventional radiology for MRI-guided wire localization immediately prior to open surgical biopsy. Under general anesthesia, wires were placed in the areas of increased T2 signal within the bilateral splenius capitis muscles using intermittent MRI-guidance followed by immediate surgical biopsy down to the wires. Pathology confirmed the diagnosis of diffuse large B-cell lymphoma.

Calibration of optical particle-size analyzer

DOEpatents

Pechin, William H.; Thacker, Louis H.; Turner, Lloyd J.

1979-01-01

This invention relates to a system for the calibration of an optical particle-size analyzer of the light-intercepting type for spherical particles, wherein a rotary wheel or disc is provided with radially-extending wires of differing diameters, each wire corresponding to a particular equivalent spherical particle diameter. These wires are passed at an appropriate frequency between the light source and the light detector of the analyzer. The reduction of light as received at the detector is a measure of the size of the wire, and the electronic signal may then be adjusted to provide the desired signal for corresponding spherical particles. This calibrator may be operated at any time without interrupting other processing.

A novel photochemical machining process for magnesium aerospace and biomedical microengineering applications

NASA Astrophysics Data System (ADS)

Allen, D. M.; Simpkins, M.; Almond, H.

2010-10-01

Research was carried out to evaluate the feasibility of fabricating perforated (filigree) magnesium microcomponents with metal wire widths of the order of the metal thickness using a photochemical machining (PCM) process. Experimentally, it has been demonstrated for the first time that metal wire widths of 0.15 mm can be achieved within a 2D, 0.25 mm thick magnesium foil to fabricate microcomponents for use as micro air vehicle (MAV) wings or stents through a bespoke PCM process. This etching process differs significantly from the industrial etching process used currently to manufacture magnesium letterpress printing plates and embossing dies.

Design of measuring system for wire diameter based on sub-pixel edge detection algorithm

NASA Astrophysics Data System (ADS)

Chen, Yudong; Zhou, Wang

2016-09-01

Light projection method is often used in measuring system for wire diameter, which is relatively simpler structure and lower cost, and the measuring accuracy is limited by the pixel size of CCD. Using a CCD with small pixel size can improve the measuring accuracy, but will increase the cost and difficulty of making. In this paper, through the comparative analysis of a variety of sub-pixel edge detection algorithms, polynomial fitting method is applied for data processing in measuring system for wire diameter, to improve the measuring accuracy and enhance the ability of anti-noise. In the design of system structure, light projection method with orthogonal structure is used for the detection optical part, which can effectively reduce the error caused by line jitter in the measuring process. For the electrical part, ARM Cortex-M4 microprocessor is used as the core of the circuit module, which can not only drive double channel linear CCD but also complete the sampling, processing and storage of the CCD video signal. In addition, ARM microprocessor can complete the high speed operation of the whole measuring system for wire diameter in the case of no additional chip. The experimental results show that sub-pixel edge detection algorithm based on polynomial fitting can make up for the lack of single pixel size and improve the precision of measuring system for wire diameter significantly, without increasing hardware complexity of the entire system.

Strain tolerance in technical Nb3Al superconductors

NASA Astrophysics Data System (ADS)

Banno, N.; Takeuchi, T.; Kitaguchi, H.; Tagawa, K.

2006-10-01

We observed crack formation in transformation-processed Nb3Al wires at room temperature, the wire being bent with a small clamp fixture with a curvature. The polished cross-section parallel to the longitudinal axis was observed, using a high power optical microscope or a field-emission scanning electron microscope. The bend strain limit for microcrack formation is found, changing the radius of the curvature of the clamp. The bend strain limit was found to be around 0.3% for standard Nb3Al wires. This corresponds to the irreversible tensile strain limit of the Ic characteristics determined with a 0.1 µV cm-1 criterion. Reduction of the barrier thickness should be avoided to keep to the bend strain limit. A new configuration of the Nb3Al wire is demonstrated to improve the bend strain limit. The filament is divided into segments in the transverse cross-section. The wire is fabricated by a double-stacking method. The bend strain limit is enhanced to about 0.85% for the wire surface; the equivalent strain of the outermost filament location is about 0.66%. A simple react and wind test for this wire was performed, where the wire experienced 0.86% bend strain. The degradation of Jc was found to be very small.

Using Drawing Technology to Assess Students' Visualizations of Chemical Reaction Processes

ERIC Educational Resources Information Center

Chang, Hsin-Yi; Quintana, Chris; Krajcik, Joseph

2014-01-01

In this study, we investigated how students used a drawing tool to visualize their ideas of chemical reaction processes. We interviewed 30 students using thinking-aloud and retrospective methods and provided them with a drawing tool. We identified four types of connections the students made as they used the tool: drawing on existing knowledge,…

The forming simulation of flexible glass with silt down draw method

NASA Astrophysics Data System (ADS)

Yansheng, Hou; Jinshu, Cheng; Junfeng, Kang; Jing, Cui

2018-03-01

The slit down draw method is the main manufacturing process of flexible glass. In this study, Flow3DTM software was used to simulate the process of drawing and thinning glass slits during the slit down draw process. The influence of glass viscosity, initial plate thickness and initial plate speed on the glass spreading process was studied. The maximum pull-down force that the root can bear is linearly proportional to the viscosity, the initial thickness of 1.3837 power and the initial plate speed, respectively. The best way to improve the tensile strength of flexible glass is to increase the viscosity. Flexible glass was more easily to obtain with low viscosity, low thickness and low drawing speed.

Single-step laser deposition of functionally graded coating by dual ‘wire powder’ or ‘powder powder’ feeding—A comparative study

NASA Astrophysics Data System (ADS)

Syed, Waheed Ul Haq; Pinkerton, Andrew J.; Liu, Zhu; Li, Lin

2007-07-01

The creation of iron-copper (Fe-Cu) alloys has practical application in improving the surface heat conduction and corrosion resistance of, for example, conformal cooling channels in steel moulds, but is difficult to achieve because the elements have got low inter-solubility and are prone to solidification cracking. Previous work by these authors has reported a method to produce a graded iron-nickel-copper coating in a single-step by direct diode laser deposition (DLD) of nickel wire and copper powder as a combined feedstock. This work investigates whether dual powder feeds can be used in that process to afford greater geometric flexibility and compares attributes of the 'nickel wire and copper powder' and 'nickel powder and copper powder' processes for deposition on a H13 tool steel substrate. In wire-powder deposition, a higher temperature developed in the melt pool causing a clad with a smooth gradient structure. The nickel powder in powder-powder deposition did not impart much heat into the melt pool so the melt pool solidified with sharp composition boundaries due to single metal melting in some parts. In wire-powder experiments, a graded structure was obtained by varying the flow rates of wire and powder. However, a graded structure was not realised in powder-powder experiments by varying either the feed or the directions. Reasons for the differences and flow patterns in the melt pools and their effect on final part properties of parts produced are discussed.

Si Wire-Array Solar Cells

NASA Astrophysics Data System (ADS)

Boettcher, Shannon

2010-03-01

Micron-scale Si wire arrays are three-dimensional photovoltaic absorbers that enable orthogonalization of light absorption and carrier collection and hence allow for the utilization of relatively impure Si in efficient solar cell designs. The wire arrays are grown by a vapor-liquid-solid-catalyzed process on a crystalline (111) Si wafer lithographically patterned with an array of metal catalyst particles. Following growth, such arrays can be embedded in polymethyldisiloxane (PDMS) and then peeled from the template growth substrate. The result is an unusual photovoltaic material: a flexible, bendable, wafer-thickness crystalline Si absorber. In this paper I will describe: 1. the growth of high-quality Si wires with controllable doping and the evaluation of their photovoltaic energy-conversion performance using a test electrolyte that forms a rectifying conformal semiconductor-liquid contact 2. the observation of enhanced absorption in wire arrays exceeding the conventional light trapping limits for planar Si cells of equivalent material thickness and 3. single-wire and large-area solid-state Si wire-array solar cell results obtained to date with directions for future cell designs based on optical and device physics. In collaboration with Michael Kelzenberg, Morgan Putnam, Joshua Spurgeon, Daniel Turner-Evans, Emily Warren, Nathan Lewis, and Harry Atwater, California Institute of Technology.

Molten thermoplastic dripping behavior induced by flame spread over wire insulation under overload currents.

PubMed

He, Hao; Zhang, Qixing; Tu, Ran; Zhao, Luyao; Liu, Jia; Zhang, Yongming

2016-12-15

The dripping behavior of the molten thermoplastic insulation of copper wire, induced by flame spread under overload currents, was investigated for a better understanding of energized electrical wire fires. Three types of sample wire, with the same polyethylene insulation thickness and different core diameters, were used in this study. First, overload current effects on the transient one-dimensional wire temperature profile were predicted using simplified theoretical analysis; the heating process and equilibrium temperature were obtained. Second, experiments on the melting characteristics were conducted in a laboratory environment, including drop formation and frequency, falling speed, and combustion on the steel base. Third, a relationship between molten mass loss and volume variation was proposed to evaluate the dripping time and frequency. A strong current was a prerequisite for the wire dripping behavior and the averaged dripping frequency was found to be proportional to the square of the current based on the theoretical and experimental results. Finally, the influence of dripping behavior on the flame propagation along the energized electrical wire was discussed. The flame width, bright flame height and flame spreading velocity presented different behaviors. Copyright © 2016 Elsevier B.V. All rights reserved.

Laser Indirect Shock Welding of Fine Wire to Metal Sheet.

PubMed

Wang, Xiao; Huang, Tao; Luo, Yapeng; Liu, Huixia

2017-09-12

The purpose of this paper is to present an advanced method for welding fine wire to metal sheet, namely laser indirect shock welding (LISW). This process uses silica gel as driver sheet to accelerate the metal sheet toward the wire to obtain metallurgical bonding. A series of experiments were implemented to validate the welding ability of Al sheet/Cu wire and Al sheet/Ag wire. It was found that the use of a driver sheet can maintain high surface quality of the metal sheet. With the increase of laser pulse energy, the bonding area of the sheet/wire increased and the welding interfaces were nearly flat. Energy dispersive spectroscopy (EDS) results show that the intermetallic phases were absent and a short element diffusion layer which would limit the formation of the intermetallic phases emerging at the welding interface. A tensile shear test was used to measure the mechanical strength of the welding joints. The influence of laser pulse energy on the tensile failure modes was investigated, and two failure modes, including interfacial failure and failure through the wire, were observed. The nanoindentation test results indicate that as the distance to the welding interface decreased, the microhardness increased due to the plastic deformation becoming more violent.

Cavitation during wire brushing

NASA Astrophysics Data System (ADS)

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.

Simple electronic apparatus for the analysis of radioactively labeled gel electrophoretograms

DOEpatents

Goulianos, Konstantin; Smith, Karen K.; White, Sebastian N.

1982-01-01

A high resolution position sensitive radiation detector for analyzing radiation emanating from a source, constructed of a thin plate having an elongated slot with conductive edges acting as a cathode, a charged anode wire positioned within 0.5 mm adjacent the source and running parallel to the slot and centered therein, an ionizable gas ionized by radiation emanating from the source provided surrounding the anode wire in the slot, a helical wire induction coil serving as a delay line and positioned beneath the anode wire for detecting gas ionization and for producing resulting ionization signals, and processing circuits coupled to the induction coil for receiving ionization signals induced therein after determining therefrom the location along the anode wire of any radiation emanating from the source. An ionization gas of 70% Ar, 29% Isobutane, 0.6% Freon 13BI, and 0.4% Methylal is used.

Studies with cathode drift chambers for the GlueX experiment at Jefferson Lab

DOE PAGES

Pentchev, L.; Barbosa, F.; Berdnikov, V.; ...

2017-04-22

A drift chamber system consisting of 24 1 m-diameter chambers with both cathode and wire readout (total of 12,672 channels) is operational in Hall D at Jefferson Lab (Virginia). Two cathode strip planes and one wire plane in each chamber register the same avalanche allowing the study of avalanche development, charge induction process, and strip resolution. We demonstrate a method for reconstructing the two-dimensional distribution of the avalanche “center-of-gravity” position around the wire from an 55Fe source with resolutions down to 30 μm. We estimate the azimuthal extent of the avalanche around the wire as a function of the totalmore » charge for an Ar/CO 2 gas mixture. By means of cluster counting using a modified 3 cm-gap chamber, we observe significant space charge effects within the same track, resulting in an extent of the avalanche along the wire.« less

Current Bypassing Properties by Thermal Switch for PCS Application on NMR/MRI HTS Magnets

NASA Astrophysics Data System (ADS)

Kim, S. B.; Takahashi, M.; Saito, R.; Park, Y. J.; Lee, M. W.; Oh, Y. K.; Ann, H. S.

We develop the compact NMR/MRI device using high temperature superconducting (HTS) wires with the persistent current mode operating. So, the joint techniques between 2G wires are very important issue and many studies have been carried out. Recently, the Kbigdot JOINS, Inc. has developed successfully the high performance superconducting joints between 2G wires by partial melting diffusion and oxygenation annealing process [1]. In this study, the current bypassing properties in a loop-shaped 2G wire are measured experimentally to develop the permanent current switch (PSC). The current bypassing properties of loop-shaped test coil wound with 2G wire (GdBCO) are evaluated by measured the self-magnetic field due to bypassed current by Hall sensors. The strain gauge was used as heater for persistent current switch, and thermal properties against various thermal inputs were investigated experimentally.

Computer simulation of metal wire explosion under high rate heating

NASA Astrophysics Data System (ADS)

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.

Manufacture and quality control of interconnecting wire harnesses, Volume 3

NASA Technical Reports Server (NTRS)

1972-01-01

The document covers interconnecting wire harnesses defined in the design standard, including type 6, enclosed in TFE heat shrink tubing; and type 7, flexible armored. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into this document.

76 FR 13976 - Notice of Request for Revision of a Currently Approved Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-15

.... SUPPLEMENTARY INFORMATION: Title: Form RD 1951-65, Customer Initiated Payments (CIP) Enrollment Form; Form RD... Initiated Payments [CIP], FedWire, and Preauthorized Debits [PAD]) for receiving and processing loan... approved forms for collecting bank routing information for CIP, FedWire, and PAD. Estimate of Burden...

Analyzing Systems Integration Best Practices and Assessment in DoD Space Systems Acquisition

DTIC Science & Technology

2009-12-01

satellite  Insufficient stress relief and insulation caused abrasion of wiring harness. C Product–Product: stress relief and insulation – wiring...delaminated during firing . This problem escaped qualification since slow heating rates (0.1–deg F/sec) used in the lab test provided time for the gas...to escape. Faster rates would have revealed the issue. E Product–Process: material – replace, firing ; rate – test B Process–Process: replace

Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

DOEpatents

Heiple, C.R.; Burgardt, P.

1984-03-13

An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

Wire Detection Algorithms for Navigation

NASA Technical Reports Server (NTRS)

Kasturi, Rangachar; Camps, Octavia I.

2002-01-01

In this research we addressed the problem of obstacle detection for low altitude rotorcraft flight. In particular, the problem of detecting thin wires in the presence of image clutter and noise was studied. Wires present a serious hazard to rotorcrafts. Since they are very thin, their detection early enough so that the pilot has enough time to take evasive action is difficult, as their images can be less than one or two pixels wide. Two approaches were explored for this purpose. The first approach involved a technique for sub-pixel edge detection and subsequent post processing, in order to reduce the false alarms. After reviewing the line detection literature, an algorithm for sub-pixel edge detection proposed by Steger was identified as having good potential to solve the considered task. The algorithm was tested using a set of images synthetically generated by combining real outdoor images with computer generated wire images. The performance of the algorithm was evaluated both, at the pixel and the wire levels. It was observed that the algorithm performs well, provided that the wires are not too thin (or distant) and that some post processing is performed to remove false alarms due to clutter. The second approach involved the use of an example-based learning scheme namely, Support Vector Machines. The purpose of this approach was to explore the feasibility of an example-based learning based approach for the task of detecting wires from their images. Support Vector Machines (SVMs) have emerged as a promising pattern classification tool and have been used in various applications. It was found that this approach is not suitable for very thin wires and of course, not suitable at all for sub-pixel thick wires. High dimensionality of the data as such does not present a major problem for SVMs. However it is desirable to have a large number of training examples especially for high dimensional data. The main difficulty in using SVMs (or any other example-based learning method) is the need for a very good set of positive and negative examples since the performance depends on the quality of the training set.

Bundled monocapillary optics

DOEpatents

Hirsch, Gregory

2002-01-01

A plurality of glass or metal wires are precisely etched to form the desired shape of the individual channels of the final polycapillary optic. This shape is created by carefully controlling the withdrawal speed of a group of wires from an etchant bath. The etched wires undergo a subsequent operation to create an extremely smooth surface. This surface is coated with a layer of material which is selected to maximize the reflectivity of the radiation being used. This reflective surface may be a single layer of material, or a multilayer coating for optimizing the reflectivity in a narrower wavelength interval. The collection of individual wires is assembled into a close-packed multi-wire bundle, and the wires are bonded together in a manner which preserves the close-pack configuration, irrespective of the local wire diameter. The initial wires are then removed by either a chemical etching procedure or mechanical force. In the case of chemical etching, the bundle is generally segmented by cutting a series of etching slots. Prior to removing the wire, the capillary array is typically bonded to a support substrate. The result of the process is a bundle of precisely oriented radiation-reflecting hollow channels. The capillary optic is used for efficiently collecting and redirecting the radiation from a source of radiation which could be the anode of an x-ray tube, a plasma source, the fluorescent radiation from an electron microprobe, a synchrotron radiation source, a reactor or spallation source of neutrons, or some other source.

Electrophoretic-like gating used to control metal-insulator transitions in electronically phase separated manganite wires.

PubMed

Guo, Hangwen; Noh, Joo H; Dong, Shuai; Rack, Philip D; Gai, Zheng; Xu, Xiaoshan; Dagotto, Elbio; Shen, Jian; Ward, T Zac

2013-08-14

Electronically phase separated manganite wires are found to exhibit controllable metal-insulator transitions under local electric fields. The switching characteristics are shown to be fully reversible, polarity independent, and highly resistant to thermal breakdown caused by repeated cycling. It is further demonstrated that multiple discrete resistive states can be accessed in a single wire. The results conform to a phenomenological model in which the inherent nanoscale insulating and metallic domains are rearranged through electrophoretic-like processes to open and close percolation channels.

Nanopowder synthesis based on electric explosion technology

NASA Astrophysics Data System (ADS)

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

2017-10-01

A computer simulation of the bicomponent nanoparticle formation during the electric explosion of copper and nickel wires was carried out. The calculations were performed in the framework of the molecular dynamics method using many-body potentials of interatomic interaction. As a result of an electric explosion of dissimilar metal wires, bicomponent nanoparticles having different stoichiometry and a block structure can be formed. It is possible to control the process of destruction and the structure of the formed bicomponent nanoparticles by varying the distance between the wires and the loading parameters.

Attachment of lead wires to thin film thermocouples mounted on high temperature materials using the parallel gap welding process

NASA Technical Reports Server (NTRS)

Holanda, Raymond; Kim, Walter S.; Pencil, Eric; Groth, Mary; Danzey, Gerald A.

1990-01-01

Parallel gap resistance welding was used to attach lead wires to sputtered thin film sensors. Ranges of optimum welding parameters to produce an acceptable weld were determined. The thin film sensors were Pt13Rh/Pt thermocouples; they were mounted on substrates of MCrAlY-coated superalloys, aluminum oxide, silicon carbide and silicon nitride. The entire sensor system is designed to be used on aircraft engine parts. These sensor systems, including the thin-film-to-lead-wire connectors, were tested to 1000 C.

Study on Electro-polymerization Nano-micro Wiring System Imitating Axonal Growth of Artificial Neurons towards Machine Learning

NASA Astrophysics Data System (ADS)

Dang, Nguyen Tuan; Akai-Kasada, Megumi; Asai, Tetsuya; Saito, Akira; Kuwahara, Yuji; Hokkaido University Collaboration

2015-03-01

Machine learning using the artificial neuron network research is supposed to be the best way to understand how the human brain trains itself to process information. In this study, we have successfully developed the programs using supervised machine learning algorithm. However, these supervised learning processes for the neuron network required the very strong computing configuration. Derivation from the necessity of increasing in computing ability and in reduction of power consumption, accelerator circuits become critical. To develop such accelerator circuits using supervised machine learning algorithm, conducting polymer micro/nanowires growing process was realized and applied as a synaptic weigh controller. In this work, high conductivity Polypyrrole (PPy) and Poly (3, 4 - ethylenedioxythiophene) PEDOT wires were potentiostatically grown crosslinking the designated electrodes, which were prefabricated by lithography, when appropriate square wave AC voltage and appropriate frequency were applied. Micro/nanowire growing process emulated the neurotransmitter release process of synapses inside a biological neuron and wire's resistance variation during the growing process was preferred to as the variation of synaptic weigh in machine learning algorithm. In a cooperation with Graduate School of Information Science and Technology, Hokkaido University.

Drawing Links between the Autism Cognitive Profile and Imagination: Executive Function and Processing Bias in Imaginative Drawings by Children with and without Autism

ERIC Educational Resources Information Center

Ten Eycke, Kayla D.; Müller, Ulrich

2018-01-01

Little is known about the relation between cognitive processes and imagination and whether this relation differs between neurotypically developing children and children with autism. To address this issue, we administered a cognitive task battery and Karmiloff-Smith's drawing task, which requires children to draw imaginative people and houses. For…

A nanofabricated wirescanner with free standing wires: Design, fabrication and experimental results

NASA Astrophysics Data System (ADS)

Veronese, M.; Grulja, S.; Penco, G.; Ferianis, M.; Fröhlich, L.; Dal Zilio, S.; Greco, S.; Lazzarino, M.

2018-05-01

Measuring the transverse size of electron beams is of crucial importance in modern accelerators, from large colliders to free electron lasers to storage rings. For this reason several kind of beam instrumentation have been developed such as optical transition radiation screens, scintillating screens, laser scanners and wire scanners. The last ones although providing only a multishot profile in one plane have demonstrated a very high resolution. Wirescanners employ thin wires with typical thickness of the order of tens of microns that are scanned across the beam, whilst ionizing radiation generated from the impact of the electrons with the wires is detected. In this paper we describe a new approach to wirescanners design based on nanofabrication technologies opening new possibilities in term of wire shape, size, material and thickness with potential for sub-micron resolution and increase flexibility for instrumentation designers. We present a device fitted with nanofabricated wires and its fabrication process. We also report the measurements performed on the FERMI FEL electron beam with the goal of providing an online profile measurement without perturbing the FEL.

Regulation of Drosophila Brain Wiring by Neuropil Interactions via a Slit-Robo-RPTP Signaling Complex.

PubMed

Oliva, Carlos; Soldano, Alessia; Mora, Natalia; De Geest, Natalie; Claeys, Annelies; Erfurth, Maria-Luise; Sierralta, Jimena; Ramaekers, Ariane; Dascenco, Dan; Ejsmont, Radoslaw K; Schmucker, Dietmar; Sanchez-Soriano, Natalia; Hassan, Bassem A

2016-10-24

The axonal wiring molecule Slit and its Round-About (Robo) receptors are conserved regulators of nerve cord patterning. Robo receptors also contribute to wiring brain circuits. Whether molecular mechanisms regulating these signals are modified to fit more complex brain wiring processes is unclear. We investigated the role of Slit and Robo receptors in wiring Drosophila higher-order brain circuits and identified differences in the cellular and molecular mechanisms of Robo/Slit function. First, we find that signaling by Robo receptors in the brain is regulated by the Receptor Protein Tyrosine Phosphatase RPTP69d. RPTP69d increases membrane availability of Robo3 without affecting its phosphorylation state. Second, we detect no midline localization of Slit during brain development. Instead, Slit is enriched in the mushroom body, a neuronal structure covering large areas of the brain. Thus, a divergent molecular mechanism regulates neuronal circuit wiring in the Drosophila brain, partly in response to signals from the mushroom body. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Integrated Electrical Wire Insulation Repair System

NASA Technical Reports Server (NTRS)

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

Composite ceramic superconducting wires for electric motor applications

NASA Astrophysics Data System (ADS)

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.

47 CFR 1.1306 - Actions which are categorically excluded from environmental processing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the installation of aerial wire or cable over existing aerial corridors of prior or permitted use or the underground installation of wire or cable along existing underground corridors of prior or permitted use, established by the applicant or others. The use of existing buildings, towers or corridors is...

Colleges Question Data Used by "Yahoo!" To Rank the "Most Wired" Campus.

ERIC Educational Resources Information Center

Young, Jeffrey R.

1997-01-01

College administrators are complaining that "Yahoo! Internet Life" magazine used a flawed surveying process and inaccurate data to select the institutions it named in a recent ranking of "American's 100 Most Wired Colleges." Even some institutions faring well in the ranking have concerns about the survey, citing problems with…

A study of narrow gap laser welding for thick plates using the multi-layer and multi-pass method

NASA Astrophysics Data System (ADS)

Li, Ruoyang; Wang, Tianjiao; Wang, Chunming; Yan, Fei; Shao, Xinyu; Hu, Xiyuan; Li, Jianmin

2014-12-01

This paper details a new method that combines laser autogenous welding, laser wire filling welding and hybrid laser-GMAW welding to weld 30 mm thick plate using a multi-layer, multi-pass process. A “Y” shaped groove was used to create the joint. Research was also performed to optimize the groove size and the processing parameters. Laser autogenous welding is first used to create the backing weld. The lower, narrowest part of the groove is then welded using laser wire filling welding. Finally, the upper part of the groove is welded using laser-GMAW hybrid welding. Additionally, the wire feeding and droplet transfer behaviors are observed by high speed photography. The two main conclusions from this work are: the wire is often biased towards the side walls, resulting in a lack of fusion at the joint and the creation of other defects for larger groove sizes. Additionally, this results in the droplet transfer behavior becoming unstable, leading to a poor weld appearance for smaller groove sizes.

Cu-Al-Ni Shape Memory Single Crystal Wires with High Transformation Temperature

NASA Technical Reports Server (NTRS)

Hautcoeur, Alain; Fouché, Florian; Sicre, Jacques

2016-01-01

CN-250X is a new material with higher performance than Nickel-Titanium Shape Memory Alloy (SMA). For space mechanisms, the main disadvantage of Nickel-Titanium Shape Memory Alloy is the limited transformation temperature. The new CN-250X Nimesis alloy is a Cu-Al-Ni single crystal wire available in large quantity because of a new industrial process. The triggering of actuators made with this Cu-Al-Ni single crystal wire can range from ambient temperature to 200 C in cycling and even to 250 C in one-shot mode. Another advantage of CN-250X is a better shape recovery (8 to 10%) than Ni-Ti (6 to 7%). Nimesis is the first company able to produce this type of material with its new special industrial process. A characterization study is presented in this work, including the two main solicitation modes for this material: tensile and torsion. Different tests measure the shape recovery of Cu-Al-Ni single crystals wires during heating from room temperature to a temperature higher than temperature of end of martensitic transformation.

Numerical analysis on temperature field in single-wire flux-aided backing-submerged arc welding

NASA Astrophysics Data System (ADS)

Pu, Juan; Wu, Ming Fang; Pan, Haichao

2017-07-01

Single-wire flux-aided backing-submerged arc welding (FAB-SAW) technology has been widely used to weld thick steel plate due to its easy assembly and high heat input. The microstructure and property of welded joint are closely related to the thermal field of FAB-SAW process. In this research, the feature of thermal field for single-wire FAB-SAW was investigated. Based on the heat transfer mechanism, a three-dimensional transient model for thermal field was developed based on the influence of steel thickness, groove angle and ceramic backing. The temperature profile in single-wire FAB-SAW of D36 steel under different welding conditions was simulated by ANSYS. The characteristic of thermal field was analyzed and the influences of groove angle on temperature field for different plate thicknesses were discussed. The calculated geometries and dimensions of weld cross-section under different conditions show a good agreement with the experimental results. This newly built model can describe the thermal field accurately, which would be helpful to understanding the thermophysical mechanism of FAB-SAW and optimizing the welding process.

Amplification of Reynolds number dependent processes by wave distortion. [acoustic instability of liquid propellant rocket engines

NASA Technical Reports Server (NTRS)

Ventrice, M. B.; Fang, J. C.; Purdy, K. R.

1975-01-01

A system using a hot-wire transducer as an analog of a liquid droplet of propellant was employed to investigate the ingredients of the acoustic instability of liquid-propellant rocket engines. It was assumed that the combustion process was vaporization-limited and that the combustion chamber was acoustically similar to a closed-closed right-circular cylinder. Before studying the hot-wire closed-loop system (the analog system), a microphone closed-loop system, which used the response of a microphone as the source of a linear feedback exciting signal, was investigated to establish the characteristics of self-sustenance of acoustic fields. Self-sustained acoustic fields were found to occur only at resonant frequencies of the chamber. In the hot-wire closed-loop system, the response of hot-wire anemometer was used as the source of the feedback exciting signal. The self-sustained acoustic fields which developed in the system were always found to be harmonically distorted and to have as their fundamental frquency a resonant frequency for which there also existed a second resonant frequency which was approximately twice the fundamental frequency.

The Process by Which Double Base Propellants with Embedded Continuous Wires are Fabricated by Use of the Screw Extruder,

DTIC Science & Technology

1983-03-08

Engineering Research Center in Xian Xian City, People’s Republic of China received June 9, 1981 Abstract This paper describes a process by which the screw... research , it is not only possible to satisfy a full range of design requirements, but also to produce double base propellant grains with continuous...arranged in a radial configuration by the application of an electrical charge. In recent years3 researches on the embedding of wires in propellant

Methods of measurement for semiconductor materials, process control, and devices

NASA Technical Reports Server (NTRS)

Bullis, W. M. (Editor)

1972-01-01

Activities directed toward the development of methods of measurement for semiconductor materials, process control, and devices are described. Topics investigated include: measurements of transistor delay time; application of the infrared response technique to the study of radiation-damaged, lithium-drifted silicon detectors; and identification of a condition that minimizes wire flexure and reduces the failure rate of wire bonds in transistors and integrated circuits under slow thermal cycling conditions. Supplementary data concerning staff, standards committee activities, technical services, and publications are included as appendixes.

Process for making RF shielded cable connector assemblies and the products formed thereby

NASA Technical Reports Server (NTRS)

Fisher, A.; Clatterbuck, C. H. (Inventor)

1973-01-01

A process for making RF shielded cable connector assemblies and the resulting structures is described. The process basically consists of potting wires of a shielded cable between the cable shield and a connector housing to fill in, support, regidize, and insulate the individual wires contained in the cable. The formed potting is coated with an electrically conductive material so as to form an entirely encompassing adhering conductive path between the cable shield and the metallic connector housing. A protective jacket is thereby formed over the conductive coating between the cable shield and the connector housing.

Red Plague Control Plan (RPCP)

NASA Technical Reports Server (NTRS)

Cooke, Robert W.

2010-01-01

SCOPE: Prescribes the minimum requirements for the control of cuprous / cupric oxide corrosion (a.k.a. Red Plague) of silver-coated copper wire, cable, and harness assemblies. PURPOSE: Targeted for applications where exposure to assembly processes, environmental conditions, and contamination may promote the development of cuprous / cupric oxide corrosion (a.k.a. Red Plague) in silver-coated copper wire, cable, and harness assemblies. Does not exclude any alternate or contractor-proprietary documents or processes that meet or exceed the baseline of requirements established by this document. Use of alternate or contractor-proprietary documents or processes shall require review and prior approval of the procuring NASA activity.

Scalable Manufacturing of Metal Micro/Nanowires and Applications by Thermal Fiber Drawing Method

NASA Astrophysics Data System (ADS)

Hwang, Injoo

The objective of this study is to better understand the fundamental principal of the thermal fiber drawing process with metal-core preforms. This would enable us to overcome the fundamental limits of current thermal drawing techniques by tuning material properties of core metals and interactions between core and cladding materials using nanoparticles. Metal micro/nanowires with controlled size, aspect ratio and spatial configurations of core and cladding materials exhibit extraordinary mechanical, thermal, electrical and optical properties. These metal micro/nanowires can be utilized for widespread applications such as: thermoelectric, conductive electrode and plasmonic photonic crystal fibers. Thermal fiber drawing method has emerged as an advanced scalable manufacturing technique for micro/nanowires production due to its unique characteristics that allow mass production of continuous and arbitrary designed wires. It is of tremendous scientific and technical interests to conduct a fundamental study on thermal fiber drawing methods and to break the current limits of the crystalline metal core thermal fiber drawing process. In this study, metal core was fabricated by cold compaction of the Zinc (Zn)-Tungsten Carbide (WC) nanopowders. Our characterizations through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) showed that WC nanoparticle are uniformly dispersed in Zn matrix. The effects of WC nanoparticles on the mechanical properties and degradation rate in Zn-WC nanocomposites were carefully analyzed by tensile, compressive, hardness, degradation and viscosity tests. Metallic stents are commonly used to expand blood vessels that have been narrowed by plaque buildup (atherosclerosis). Fabrication difficulty and other constrains of metallic stents result in high cost. Zn-WC nanocomposite microwires were controllably drawn for stent struts with a diameter of 200 ?m. Characterizations by the tensile and degradation tests of Zn-WC nanocomposite microwires validate the eligibility for stent fabrication. Single cell Zn-WC nanocomposite stents were fabricated by braiding thermally drawn Zn-WC nanocomposite microwires on a weaving stage built by 3D printing. Zn-WC nanocomposite stents with an inner diameter of 2 mm was expanded up to 10 mm without recoil by a catheter, which is thin tube inserted into human body serving in a broad range of functions. For the purpose of in vivo test, Zn-WC nanocomposite stents were deployed in a pig by percutaneous coronary intervention method (angioplasty with stent). The surgery under fluoroscopy that continuous X-ray beam is passed through the body part being examined. X-ray opaque Zn-WC nanocomposite stents were distinctly shown to be expanded by a catheter and remained without bounce back through the whole procedure. The Zn-WC nanocomposite stents were extracted from the pig a month later and studied for the degradability by SEM and EDS mapping analysis. SEM images of Zn-WC stents showed that the degradation of the stents was uniformly proceeded on the surface without fractures. While the Zn-WC nanocomposite stents stayed inside the vessel, good endothelializations between the Zn-WC stents and surrounding cell tissues as well as no acute pathological problems were discovered from this study. One of the current challenges of thermal fiber drawing process for crystalline metal nanowires is low aspect ratio (< 10,000). A molten metal nanowire in a cladding material breaks up into shorter nanowires or smaller droplets due to Plateau-Rayleigh instability. It was experimentally and theoretically shown that molten liquid tends to minimize their surface area by virtue of surface tensions. The Tomotika model introduced the relation among instability time, viscosities of core and cladding materials, the wavelength and diameter of the core fluid, and interfacial energy between core and cladding materials as specifying the Plateau-Rayleigh instability [1]. The instability time was impeded by high viscosity of the Zn-WC nanocomposite core material while the preform of Zn-WC nanocomposite was thermally drawn by the stack-and-draw method. Consequently, high aspect ratio (> 1,500,000) of Zn-WC nanocomposite nanowires that are 200 nm in diameter and up to 31 cm length were achieved. Herein, we present that WC nanoparticles decreased interfacial energy between metal and glass due to its inherent characteristic such as partly metallic bonding. As a result, the nanoparticle can play the role of anchors to prevent breakage by capillary instability in nanoscale thermal fiber drawing process. Zn-WC nanocomposite nanowires surrounded by borosilicate glass were shown through the TEM (transmission electron microscope) diffraction patterns. By the electrical resistance test, not onlythe electrical resistance and but also the continuity of the Zn-WC nanocomposite nanowires was presented. (Abstract shortened by ProQuest.).

In-Situ Wire Damage Detection System

NASA Technical Reports Server (NTRS)

Williams, Martha; Roberson, Luke; Tate, Lanetra; Smith, Trent; Gibson, Tracy; Medelius, Pedro; Jolley, Scott

2012-01-01

An In-Situ Wire Damage Detection System (ISWDDS) has been developed that is capable of detecting damage to a wire insulation, or a wire conductor, or to both. The system will allow for realtime, continuous monitoring of wiring health/integrity and reduce the number of false negatives and false positives while being smaller, lighter in weight, and more robust than current systems. The technology allows for improved safety and significant reduction in maintenance hours for aircraft, space vehicles, satellites, and other critical high-performance wiring systems for industries such as energy production and mining. The integrated ISWDDS is comprised of two main components: (1) a wire with an innermost core conductor, an inner insulation film, a conductive layer or inherently conductive polymer (ICP) covering the inner insulation film, an outermost insulation jacket; and (2) smart connectors and electronics capable of producing and detecting electronic signals, and a central processing unit (CPU) for data collection and analysis. The wire is constructed by applying the inner insulation films to the conductor, followed by the outer insulation jacket. The conductive layer or ICP is on the outer surface of the inner insulation film. One or more wires are connected to the CPU using the smart connectors, and up to 64 wires can be monitored in real-time. The ISWDDS uses time domain reflectometry for damage detection. A fast-risetime pulse is injected into either the core conductor or conductive layer and referenced against the other conductor, producing transmission line behavior. If either conductor is damaged, then the signal is reflected. By knowing the speed of propagation of the pulse, and the time it takes to reflect, one can calculate the distance to and location of the damage.

Real time remote monitoring and pre-warning system for Highway landslide in mountain area.

PubMed

Zhang, Yonghui; Li, Hongxu; Sheng, Qian; Wu, Kai; Chen, Guoliang

2011-06-01

The wire-pulling trigger displacement meter with precision of 1 mm and the grid pluviometer with precision of 0.1 mm are used to monitor the surface displacement and rainfall for Highway slope, and the measured data are transferred to the remote computer in real time by general packet radio service (GPRS) net of China telecom. The wire-pulling trigger displacement meter, grid pluviometer, data acquisition and transmission unit, and solar power supply device are integrated to form a comprehensive monitoring hardware system for Highway landslide in mountain area, which proven to be economical, energy-saving, automatic and high efficient. Meantime, based on the map and geographic information system (MAPGIS) platform, the software system is also developed for three dimensional (3D) geology modeling and visualization, data inquiring and drawing, stability calculation, displacement forecasting, and real time pre-warning. Moreover, the pre-warning methods based on monitoring displacement and rainfall are discussed. The monitoring and forecasting system for Highway landslide has been successfully applied in engineering practice to provide security for Highway transportation and construction and reduce environment disruption. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Bio-inspired multistructured conical copper wires for highly efficient liquid manipulation.

PubMed

Wang, Qianbin; Meng, Qingan; Chen, Ming; Liu, Huan; Jiang, Lei

2014-09-23

Animal hairs are typical structured conical fibers ubiquitous in natural system that enable the manipulation of low viscosity liquid in a well-controlled manner, which serves as the fundamental structure in Chinese brush for ink delivery in a controllable manner. Here, drawing inspiration from these structure, we developed a dynamic electrochemical method that enables fabricating the anisotropic multiscale structured conical copper wire (SCCW) with controllable conicity and surface morphology. The as-prepared SCCW exhibits a unique ability for manipulating liquid with significantly high efficiency, and over 428 times greater than its own volume of liquid could be therefore operated. We propose that the boundary condition of the dynamic liquid balance behavior on conical fibers, namely, steady holding of liquid droplet at the tip region of the SCCW, makes it an excellent fibrous medium to manipulate liquid. Moreover, we demonstrate that the titling angle of the SCCW can also affect its efficiency of liquid manipulation by virtue of its mechanical rigidity, which is hardly realized by flexible natural hairs. We envision that the bio-inspired SCCW could give inspiration in designing materials and devices to manipulate liquid in a more controllable way and with high efficiency.

Study of the effect of varying core diameter, shell thickness and strain velocity on the tensile properties of single crystals of Cu-Ag core-shell nanowire using molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Sarkar, Jit; Das, D. K.

2018-01-01

Core-shell type nanostructures show exceptional properties due to their unique structure having a central solid core of one type and an outer thin shell of another type which draw immense attention among researchers. In this study, molecular dynamics simulations are carried out on single crystals of copper-silver core-shell nanowires having wire diameter ranging from 9 to 30 nm with varying core diameter, shell thickness, and strain velocity. The tensile properties like yield strength, ultimate tensile strength, and Young's modulus are studied and correlated by varying one parameter at a time and keeping the other two parameters constant. The results obtained for a fixed wire size and different strain velocities were extrapolated to calculate the tensile properties like yield strength and Young's modulus at standard strain rate of 1 mm/min. The results show ultra-high tensile properties of copper-silver core-shell nanowires, several times than that of bulk copper and silver. These copper-silver core-shell nanowires can be used as a reinforcing agent in bulk metal matrix for developing ultra-high strength nanocomposites.

Laser Indirect Shock Welding of Fine Wire to Metal Sheet

PubMed Central

Wang, Xiao; Huang, Tao; Luo, Yapeng; Liu, Huixia

2017-01-01

The purpose of this paper is to present an advanced method for welding fine wire to metal sheet, namely laser indirect shock welding (LISW). This process uses silica gel as driver sheet to accelerate the metal sheet toward the wire to obtain metallurgical bonding. A series of experiments were implemented to validate the welding ability of Al sheet/Cu wire and Al sheet/Ag wire. It was found that the use of a driver sheet can maintain high surface quality of the metal sheet. With the increase of laser pulse energy, the bonding area of the sheet/wire increased and the welding interfaces were nearly flat. Energy dispersive spectroscopy (EDS) results show that the intermetallic phases were absent and a short element diffusion layer which would limit the formation of the intermetallic phases emerging at the welding interface. A tensile shear test was used to measure the mechanical strength of the welding joints. The influence of laser pulse energy on the tensile failure modes was investigated, and two failure modes, including interfacial failure and failure through the wire, were observed. The nanoindentation test results indicate that as the distance to the welding interface decreased, the microhardness increased due to the plastic deformation becoming more violent. PMID:28895900

Photoelastic analysis of stress generated by wires when conventional and self-ligating brackets are used: A pilot study

PubMed Central

Sobral, Guilherme Caiado; Vedovello, Mário; Degan, Viviane Veroni; Santamaria, Milton

2014-01-01

OBJECTIVE: By means of a photoelastic model, this study analyzed the stress caused on conventional and self-ligating brackets with expanded arch wires. METHOD: Standard brackets were adhered to artificial teeth and a photoelastic model was prepared using the Interlandi 19/12 diagram as base. Successive activations were made with 0.014-in and 0.018-in rounded cross section Nickel-Titanium wires (NiTi) and 0.019 x 0.025-in rectangular stainless steel wires all of which made on 22/14 Interlandi diagram. The model was observed on a plane polariscope - in a dark field microscope configuration - and photographed at each exchange of wire. Then, they were replaced by self-ligating brackets and the process was repeated. Analysis was qualitative and observed stress location and pattern on both models analyzed. CONCLUSIONS: Results identified greater stress on the region of the apex of premolars in both analyzed models. Upon comparing the stress between models, a greater amount of stress was found in the model with conventional brackets in all of its wires. Therefore, the present pilot study revealed that alignment of wires in self-ligating brackets produced lower stress in periodontal tissues in expansive mechanics. PMID:25715719

Recoverable Wire-Shaped Supercapacitors with Ultrahigh Volumetric Energy Density for Multifunctional Portable and Wearable Electronics.

PubMed

Shi, Minjie; Yang, Cheng; Song, Xuefeng; Liu, Jing; Zhao, Liping; Zhang, Peng; Gao, Lian

2017-05-24

Wire-shaped supercapacitors (SCs) based on shape memory materials are of considerable interest for next-generation portable and wearable electronics. However, the bottleneck in this field is how to develop the devices with excellent electrochemical performance while well-maintaining recoverability and flexibility. Herein, a unique asymmetric electrode concept is put forward to fabricate smart wire-shaped SCs with ultrahigh energy density, which is realized by using porous carbon dodecahedra coated on NiTi alloy wire and flexible graphene fiber as yarn electrodes. Notably, the wire-shaped SCs not only exhibit high flexibility that can be readily woven into real clothing but also represent the available recoverable ability. When irreversible plastic deformations happen, the deformed shape of the devices can automatically resume the initial predesigned shape in a warm environment (about 35 °C). More importantly, the wire-shaped SCs act as efficient energy storage devices, which display high volumetric energy density (8.9 mWh/cm 3 ), volumetric power density (1080 mW/cm 3 ), strong durability in multiple mechanical states, and steady electrochemical behavior after repeated shape recovery processes. Considering their relative facile fabrication technology and excellent electrochemical performance, this asymmetric electrode strategy produced smart wire-shaped supercapacitors desirable for multifunctional portable and wearable electronics.

Charge Transport in 4 nm Molecular Wires with Interrupted Conjugation: Combined Experimental and Computational Evidence for Thermally Assisted Polaron Tunneling.

PubMed

Taherinia, Davood; Smith, Christopher E; Ghosh, Soumen; Odoh, Samuel O; Balhorn, Luke; Gagliardi, Laura; Cramer, Christopher J; Frisbie, C Daniel

2016-04-26

We report the synthesis, transport measurements, and electronic structure of conjugation-broken oligophenyleneimine (CB-OPI 6) molecular wires with lengths of ∼4 nm. The wires were grown from Au surfaces using stepwise aryl imine condensation reactions between 1,4-diaminobenzene and terephthalaldehyde (1,4-benzenedicarbaldehyde). Saturated spacers (conjugation breakers) were introduced into the molecular backbone by replacing the aromatic diamine with trans-1,4-diaminocyclohexane at specific steps during the growth processes. FT-IR and ellipsometry were used to follow the imination reactions on Au surfaces. Surface coverages (∼4 molecules/nm(2)) and electronic structures of the wires were determined by cyclic voltammetry and UV-vis spectroscopy, respectively. The current-voltage (I-V) characteristics of the wires were acquired using conducting probe atomic force microscopy (CP-AFM) in which an Au-coated AFM probe was brought into contact with the wires to form metal-molecule-metal junctions with contact areas of ∼50 nm(2). The low bias resistance increased with the number of saturated spacers, but was not sensitive to the position of the spacer within the wire. Temperature dependent measurements of resistance were consistent with a localized charge (polaron) hopping mechanism in all of the wires. Activation energies were in the range of 0.18-0.26 eV (4.2-6.0 kcal/mol) with the highest belonging to the fully conjugated OPI 6 wire and the lowest to the CB3,5-OPI 6 wire (the wire with two saturated spacers). For the two other wires with a single conjugation breaker, CB3-OPI 6 and CB5-OPI 6, activation energies of 0.20 eV (4.6 kcal/mol) and 0.21 eV (4.8 kcal/mol) were found, respectively. Computational studies using density functional theory confirmed the polaronic nature of charge carriers but predicted that the semiclassical activation energy of hopping should be higher for CB-OPI molecular wires than for the OPI 6 wire. To reconcile the experimental and computational results, we propose that the transport mechanism is thermally assisted polaron tunneling in the case of CB-OPI wires, which is consistent with their increased resistance.

Formability analysis of aluminum alloys through deep drawing process

NASA Astrophysics Data System (ADS)

Pranavi, U.; Janaki Ramulu, Perumalla; Chandramouli, Ch; Govardhan, Dasari; Prasad, PVS. Ram

2016-09-01

Deep drawing process is a significant metal forming process used in the sheet metal forming operations. From this process complex shapes can be manufactured with fewer defects. Deep drawing process has different effectible process parameters from which an optimum level of parameters should be identified so that an efficient final product with required mechanical properties will be obtained. The present work is to evaluate the formability of Aluminum alloy sheets using deep drawing process. In which effects of punch radius, lubricating conditions, die radius, and blank holding forces on deep drawing process observed for AA 6061 aluminum alloy sheet of 2 mm thickness. The numerical simulations are performed for deep drawing of square cups using three levels of aforesaid parameters like lubricating conditions and blank holding forces and two levels of punch radii and die radii. For numerical simulation a commercial FEM code is used in which Hollomon's power law and Hill's 1948 yield criterions are implemented. The deep drawing setup used in the FEM code is modeled using a CAD tool by considering the modeling requirements from the literature. Two different strain paths (150x150mm and 200x200mm) are simulated. Punch forces, thickness distributions and dome heights are evaluated for all the conditions. In addition failure initiation and propagation is also observed. From the results, by increasing the coefficient of friction and blank holding force, punch force, thickness distribution and dome height variations are observed. The comparison has done and the optimistic parameters were suggested from the results. From this work one can predict the formability for different strain paths without experimentation.

The influence of carbon content on cyclic fatigue of NiTi SMA wires.

PubMed

Matheus, T C U; Menezes, W M M; Rigo, O D; Kabayama, L K; Viana, C S C; Otubo, J

2011-06-01

To evaluate two NiTi wires with different carbon and oxygen contents in terms of mechanical resistance to rotary bending fatigue (RBF) under varied parameters of strain amplitude and rotational speed. The wires produced from two vacuum induction melting (VIM) processed NiTi ingots were tested, Ti-49.81 at%Ni and Ti-50.33 at%Ni, named VIM 1 and VIM 2. A brief analysis related to wire fabrication is also presented, as well as chemical and microstructural analysis by energy dispersive spectroscopy (EDS) and optical microscope, respectively. A computer controlled RBF machine was specially constructed for the tests. Three radii of curvature were used: 50.0, 62.5 and 75.0 mm, respectively, R(1), R(2) and R(3), resulting in three strain amplitudes ε(a) : 1.00%, 0.80% and 0.67%. The selected rotational speeds were 250 and 455 rpm. The VIM 1 wire had a high carbon content of 0.188 wt% and a low oxygen content of 0.036 wt%. The oxygen and carbon contents of wire VIM 2 did not exceed their maximum, of 0.070 and 0.050 wt%, according to ASTM standard (ASTM F-2063-00 2001). The wire with lower carbon content performed better when compared to the one with higher carbon content, withstanding 29,441 and 12,895 cycles, respectively, to fracture. The surface quality of the wire was associated with resistance to cyclic fatigue. Surface defects acted as stress concentrators points. Overall, the number of cycles to failure was higher for VIM 2 wires with lower carbon content. © 2011 International Endodontic Journal.

Metallurgical characterization of M-Wire nickel-titanium shape memory alloy used for endodontic rotary instruments during low-cycle fatigue.

PubMed

Ye, Jia; Gao, Yong

2012-01-01

Rotary instruments made of a new nickel-titanium (NiTi) alloy (M-Wire) have shown improved cyclic fatigue resistance and mechanical properties compared with those made of conventional superelastic NiTi wires. The objective of this study was to characterize microstructural changes of M-Wire throughout the cyclic fatigue process under controlled strain amplitude. The average fatigue life was calculated from 30 M-Wire samples that were subjected to a strain-controlled (≈ 4%) rotating bend fatigue test at room temperature and rotational speed of 300 rpm. Microstructural evolution of M-Wire has been investigated by different metallurgical characterization techniques, including differential scanning calorimetry, Vickers microhardness, and transmission electron microscopy at 4 different stages (as-received state, 30%, 60%, and 90% of average fatigue life). During rotating bend fatigue test, no statistically significant difference (P > .05) was found on austenite finish temperatures between as-received M-Wire and fatigued samples. However, significant differences (P < .05) were observed on Vickers microhardness for samples with 60% and 90% fatigue life compared with as-received and 30% fatigue life. Coincidentally, substantial growth of martensite grains and martensite twins was observed in microstructure under transmission electron microscopy after 60% fatigue life. The results of the present study suggested that endodontic instruments manufactured with M-Wire are expected to have higher strength and wear resistance than similar instruments made of conventional superelastic NiTi wires because of its unique nano-crystalline martensitic microstructure. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Influence of asymmetrical drawing radius deviation in micro deep drawing

NASA Astrophysics Data System (ADS)

Heinrich, L.; Kobayashi, H.; Shimizu, T.; Yang, M.; Vollertsen, F.

2017-09-01

Nowadays, an increasing demand for small metal parts in electronic and automotive industries can be observed. Deep drawing is a well-suited technology for the production of such parts due to its excellent qualities for mass production. However, the downscaling of the forming process leads to new challenges in tooling and process design, such as high relative deviation of tool geometry or blank displacement compared to the macro scale. FEM simulation has been a widely-used tool to investigate the influence of symmetrical process deviations as for instance a global variance of the drawing radius. This study shows a different approach that allows to determine the impact of asymmetrical process deviations on micro deep drawing. In this particular case the impact of an asymmetrical drawing radius deviation and blank displacement on cup geometry deviation was investigated for different drawing ratios by experiments and FEM simulation. It was found that both variations result in an increasing cup height deviation. Nevertheless, with increasing drawing ratio a constant drawing radius deviation has an increasing impact, while blank displacement results in a decreasing offset of the cups geometry. This is explained by different mechanisms that result in an uneven cup geometry. While blank displacement leads to material surplus on one side of the cup, an unsymmetrical radius deviation on the other hand generates uneven stretching of the cups wall. This is intensified for higher drawing ratios. It can be concluded that the effect of uneven radius geometry proves to be of major importance for the production of accurately shaped micro cups and cannot be compensated by intentional blank displacement.

Drawing as Instrument, Drawings as Evidence: Capturing Mental Processes with Pencil and Paper

PubMed Central

Puglionesi, Alicia

2016-01-01

Researchers in the mind sciences often look to the production and analysis of drawings to reveal the mental processes of their subjects. This essay presents three episodes that trace the emergence of drawing as an instrumental practice in the study of the mind. Between 1880 and 1930, drawings gained currency as a form of scientific evidence – as stable, reproducible signals from a hidden interior. I begin with the use of drawings as data in the child study movement, move to the telepathic transmission of drawings in psychical research and conclude with the development of drawing as an experimental and diagnostic tool for studying neurological impairment. Despite significant shifts in the theoretical and disciplinary organisation of the mind sciences in the early twentieth century, researchers attempted to stabilise the use of subject-generated drawings as evidence by controlling the contexts in which drawings were produced and reproduced, and crafting subjects whose interiority could be effectively circumscribed. While movements such as psychoanalysis and art therapy would embrace the narrative interpretation of patient art, neuropsychology continued to utilise drawings as material traces of cognitive functions. PMID:27292325

Drawing as Instrument, Drawings as Evidence: Capturing Mental Processes with Pencil and Paper.

PubMed

Puglionesi, Alicia

2016-07-01

Researchers in the mind sciences often look to the production and analysis of drawings to reveal the mental processes of their subjects. This essay presents three episodes that trace the emergence of drawing as an instrumental practice in the study of the mind. Between 1880 and 1930, drawings gained currency as a form of scientific evidence - as stable, reproducible signals from a hidden interior. I begin with the use of drawings as data in the child study movement, move to the telepathic transmission of drawings in psychical research and conclude with the development of drawing as an experimental and diagnostic tool for studying neurological impairment. Despite significant shifts in the theoretical and disciplinary organisation of the mind sciences in the early twentieth century, researchers attempted to stabilise the use of subject-generated drawings as evidence by controlling the contexts in which drawings were produced and reproduced, and crafting subjects whose interiority could be effectively circumscribed. While movements such as psychoanalysis and art therapy would embrace the narrative interpretation of patient art, neuropsychology continued to utilise drawings as material traces of cognitive functions.

Processing and Characterization of Nickel-Manganese-Gallium Shape-Memory Fibers and Foams

NASA Astrophysics Data System (ADS)

Zheng, Peiqi-Paige

Ferromagnetic Ni-Mn-Ga shape memory alloys with large magnetic field-induced strains are promising candidates for actuators. Magnetic shape memory alloys display magnetic-field-induced strain (MFIS) of up to 10%, as single crystals. Polycrystalline materials are much easier to create but display a near-zero MFIS because twinning of neighboring grains introduces strain incompatibility leading to high internal stresses. Pores reduce these incompatibilities between grains and thus increase the MFIS of polycrystalline Ni-Mn-Ga which after training (thermo-magneto-mechanical cycling) exhibits MFIS as high as 8.7%. In this thesis, a systematic study of the effect of porosity on the magneto-mechanical properties of polycrystalline Ni-Mn-Ga foams is presented. The MFIS increased with increasing porosity, demonstrating that removal of constraints by addition of porosity is responsible for the high MFIS in polycrystalline foams. Ni-Mn-Ga foams with 57 volume percent of 355-500 micrometers open pores, with and without directional solidification were cast replicated. One directional solidified foam specimen showed a maximum magnetic-field induced strain of 0.65%, which is twice the value displayed by other foam specimens without directional solidification. This improvement is consistent with a reduction of incompatibility stresses under magnetic field from the reduced crystallographic misorientation between neighboring grains. Polycrystalline Ni-Mn-Ga foam displays ˜1% MFIS after the hermo-magnetic training. To show this effect in this highly textured sample, neutron diffraction texture measurements were conducted with a magnetic field applied at various orientations to the sample, demonstrating that selection of martensite variants takes place during cooling. Oligocrystalline Ni-Mn-Ga foams with an open porosity of 63.5?0.7% were created by a sintering replication process using NaCl space-holders. The high surface/volume ratio and mechanical stability under cyclic strain makes polycrystalline Ni-Mn-Ga metallic foams attractive for magnetic refrigeration. Compared to a polycrystalline bulk material, open-cells Ni-Mn-Ga foams shows a reduction in the temperature span of the phase transition and an increase in the magnetocaloric effect (MCE). Ni-Mn-Ga wires with sub-millimeter diameter, either as individual wires or as part of a 2D/3D wire assemblies, are promising candidates for actuators, sensors, magnetic cooling systems and energy harvesting devices. Here, we report the mechanical behavior of oligocrystalline Ni-Mn-Ga Taylor wires by tensile tests at room temperature. Magnetic-field induced shape recovery is demonstrated at 0°C in a martensitic Ni-Mn-Ga microwire, where a mechanically-produced 120° bend is recovered near fully within a magnetic field produced by permanent magnets. Tubes of the ferromagnetic shape-memory alloy Ni-Mn-Ga of composition near the Ni2MnGa Heusler phase can be used, alone or combined in structures, in magnetic actuators or magnetic refrigerators. However, fabrication of Ni-Mn-Ga tubes with sub-millimeter diameter by classical cold or hot drawing methods is hampered by the brittleness of the alloy. Here, we demonstrate a new process, where Ni-Mn-Ga tubes are fabricated by interdiffusion of Mn and Ga into drawn, ductile Ni tubes with 500 and 760 micrometers inner and outer diameters.

Technology That's Ready and Able to Inspect Those Cables

NASA Technical Reports Server (NTRS)

2005-01-01

Attempting to locate a malfunctioning wire in a complex bundle of wires or in a cable that is concealed behind a wall is as difficult as trying to find a needle in a haystack. The result of such an effort can also be costly, time-consuming, and frustrating, whether it is the tedious process of examining cable connections for the Space Shuttle or troubleshooting a cable television hookup. Furthermore, other maintenance restrictions can compound the effort required to locate and repair a particular wiring problem. For example, on the Space Shuttle, once a repair is completed, all systems that have a wire passing through any of the connectors that were disconnected during troubleshooting are affected and, therefore, must undergo retesting, an arduous task that is completely unrelated to the original problem. In an effort to streamline wire inspection and maintenance, two contractors supporting NASA's Kennedy Space Center invented the Standing Wave Reflectometer (SWR) in 1999. In doing so, they leveraged technology that was first developed to detect problems that could lead to aircraft accidents, such as the one that resulted in the catastrophic failure of TWA flight 800 in 1996. The SWR performs a non-intrusive inspection that verifies the condition of electrical power and signal-distribution systems inside the Space Shuttle orbiters. Such testing reduces processing delays and ensures safe operation of these systems.

An experimental platform for pulsed-power driven magnetic reconnection

NASA Astrophysics Data System (ADS)

Hare, J. D.; Suttle, L. G.; Lebedev, S. V.; Loureiro, N. F.; Ciardi, A.; Chittenden, J. P.; Clayson, T.; Eardley, S. J.; Garcia, C.; Halliday, J. W. D.; Robinson, T.; Smith, R. A.; Stuart, N.; Suzuki-Vidal, F.; Tubman, E. R.

2018-05-01

We describe a versatile pulsed-power driven platform for magnetic reconnection experiments, based on the exploding wire arrays driven in parallel [Suttle et al., Phys. Rev. Lett. 116, 225001 (2016)]. This platform produces inherently magnetised plasma flows for the duration of the generator current pulse (250 ns), resulting in a long-lasting reconnection layer. The layer exists for long enough to allow the evolution of complex processes such as plasmoid formation and movement to be diagnosed by a suite of high spatial and temporal resolution laser-based diagnostics. We can access a wide range of magnetic reconnection regimes by changing the wire material or moving the electrodes inside the wire arrays. We present results with aluminium and carbon wires, in which the parameters of the inflows and the layer that forms are significantly different. By moving the electrodes inside the wire arrays, we change how strongly the inflows are driven. This enables us to study both symmetric reconnection in a range of different regimes and asymmetric reconnection.

Improved microstructure and mechanical properties in gas tungsten arc welded aluminum joints by using graphene nanosheets/aluminum composite filler wires.

PubMed

Fattahi, M; Gholami, A R; Eynalvandpour, A; Ahmadi, E; Fattahi, Y; Akhavan, S

2014-09-01

In the present study, different amounts of graphene nanosheets (GNSs) were added to the 4043 aluminum alloy powders by using the mechanical alloying method to produce the composite filler wires. With each of the produced composite filler wires, one all-weld metal coupon was welded using the gas tungsten arc (GTA) welding process. The microstructure, mechanical properties and fracture surface morphology of the weld metals have been evaluated and the results are compared. As the amount of GNSs in the composition of filler wire is increased, the microstructure of weld metal was changed from the dendritic structure to fine equiaxed grains. Furthermore, the tensile strength and microhardness of weld metal was improved, and is attributed to the augmented nucleation and retarded growth. From the results, it was seen that the GNSs/Al composite filler wire can be used to improve the microstructure and mechanical properties of GTA weld metals of aluminum and its alloys. Copyright © 2014 Elsevier Ltd. All rights reserved.

Electron transport in gated InGaAs and InAsP quantum well wires in selectively grown InP ridge structures

NASA Astrophysics Data System (ADS)

Granger, G.; Kam, A.; Studenikin, S. A.; Sachrajda, A. S.; Aers, G. C.; Williams, R. L.; Poole, P. J.

2010-09-01

The purpose of this work is to fabricate ribbon-like InGaAs and InAsP wires embedded in InP ridge structures and investigate their transport properties. The InP ridge structures that contain the wires are selectively grown by chemical beam epitaxy (CBE) on pre-patterned InP substrates. To optimize the growth and micro-fabrication processes for electronic transport, we explore the Ohmic contact resistance, the electron density, and the mobility as a function of the wire width using standard transport and Shubnikov-de Haas measurements. At low temperatures the ridge structures reveal reproducible mesoscopic conductance fluctuations. We also fabricate ridge structures with submicron gate electrodes that exhibit non-leaky gating and good pinch-off characteristics acceptable for device operation. Using such wrap gate electrodes, we demonstrate that the wires can be split to form quantum dots evidenced by Coulomb blockade oscillations in transport measurements.

Energy-Conversion Properties of Vapor-Liquid-Solid-Grown Silicon Wire-Array Photocathodes

NASA Astrophysics Data System (ADS)

Boettcher, Shannon W.; Spurgeon, Joshua M.; Putnam, Morgan C.; Warren, Emily L.; Turner-Evans, Daniel B.; Kelzenberg, Michael D.; Maiolo, James R.; Atwater, Harry A.; Lewis, Nathan S.

2010-01-01

Silicon wire arrays, though attractive materials for use in photovoltaics and as photocathodes for hydrogen generation, have to date exhibited poor performance. Using a copper-catalyzed, vapor-liquid-solid-growth process, SiCl4 and BCl3 were used to grow ordered arrays of crystalline p-type silicon (p-Si) microwires on p+-Si(111) substrates. When these wire arrays were used as photocathodes in contact with an aqueous methyl viologen2+/+ electrolyte, energy-conversion efficiencies of up to 3% were observed for monochromatic 808-nanometer light at fluxes comparable to solar illumination, despite an external quantum yield at short circuit of only 0.2. Internal quantum yields were at least 0.7, demonstrating that the measured photocurrents were limited by light absorption in the wire arrays, which filled only 4% of the incident optical plane in our test devices. The inherent performance of these wires thus conceptually allows the development of efficient photovoltaic and photoelectrochemical energy-conversion devices based on a radial junction platform.

Energy-conversion properties of vapor-liquid-solid-grown silicon wire-array photocathodes.

PubMed

Boettcher, Shannon W; Spurgeon, Joshua M; Putnam, Morgan C; Warren, Emily L; Turner-Evans, Daniel B; Kelzenberg, Michael D; Maiolo, James R; Atwater, Harry A; Lewis, Nathan S

2010-01-08

Silicon wire arrays, though attractive materials for use in photovoltaics and as photocathodes for hydrogen generation, have to date exhibited poor performance. Using a copper-catalyzed, vapor-liquid-solid-growth process, SiCl4 and BCl3 were used to grow ordered arrays of crystalline p-type silicon (p-Si) microwires on p+-Si(111) substrates. When these wire arrays were used as photocathodes in contact with an aqueous methyl viologen(2+/+) electrolyte, energy-conversion efficiencies of up to 3% were observed for monochromatic 808-nanometer light at fluxes comparable to solar illumination, despite an external quantum yield at short circuit of only 0.2. Internal quantum yields were at least 0.7, demonstrating that the measured photocurrents were limited by light absorption in the wire arrays, which filled only 4% of the incident optical plane in our test devices. The inherent performance of these wires thus conceptually allows the development of efficient photovoltaic and photoelectrochemical energy-conversion devices based on a radial junction platform.

Obstacle Detection Algorithms for Rotorcraft Navigation

NASA Technical Reports Server (NTRS)

Kasturi, Rangachar; Camps, Octavia I.; Huang, Ying; Narasimhamurthy, Anand; Pande, Nitin; Ahumada, Albert (Technical Monitor)

2001-01-01

In this research we addressed the problem of obstacle detection for low altitude rotorcraft flight. In particular, the problem of detecting thin wires in the presence of image clutter and noise was studied. Wires present a serious hazard to rotorcrafts. Since they are very thin, their detection early enough so that the pilot has enough time to take evasive action is difficult, as their images can be less than one or two pixels wide. After reviewing the line detection literature, an algorithm for sub-pixel edge detection proposed by Steger was identified as having good potential to solve the considered task. The algorithm was tested using a set of images synthetically generated by combining real outdoor images with computer generated wire images. The performance of the algorithm was evaluated both, at the pixel and the wire levels. It was observed that the algorithm performs well, provided that the wires are not too thin (or distant) and that some post processing is performed to remove false alarms due to clutter.

Nuclear cargo detector

DOEpatents

Christo, Steven Basil

2006-12-19

Apparatus for the inspection of cargo containers for nuclear materials comprising one or more arrays of modules comprising grounded, closed conductive tubes filled with an ionizing gas mixture such as, but not limited to, Argon:CO.sub.2. A wire is suspended along each tube axis and electrically connected at both ends of the tube. A positive, dc high voltage is supplied to one end of the wire and an amplifier is attached to the other end through a capacitance to decouple the amplifier from the high voltage. X-rays, gamma rays or neutrons produced by nuclear material and passing through the tube ionize the gas. The electrons from the gas ionization process are accelerated toward the wire surface due to the wire's electrical potential. The acceleration of the electrons near the wire's surface is sufficient to ionize more gas and produce an amplification of electrons/ions that create a surge of current large enough to be detectable by the amplifier. Means are also provided for a warning device coupled to the amplifier.

Casting of superconducting composite materials (M-4)

NASA Technical Reports Server (NTRS)

Togano, Kazumasa

1993-01-01

An aluminum-lead-bismuth alloy is a flexible alloy and is promising for easily workable embedded-type, filament-dispersed superconducting wire material. It is difficult to produce homogeneous ingots of this material because it is easily separated into elements when melted on Earth due to the large specific gravity differences. In this experiment, a homogeneous alloy will first be produced in molten state in microgravity. It will then be returned to Earth and processed into a wire or tape form. It will then be dispersed as the second phase in micro texture form into the primary phase of aluminum. Superconducting wire material with high-critical-magnetic-field characteristics will be produced. The texture of the material will be observed, and its performance will be evaluated. In addition to the above alloy, a four-element alloy will be produced from silver, a rare Earth element, barium, and copper. The alloys will be oxidized and drawn into wire after being returned to Earth. The materials are expected to be forerunners in obtaining superconducting wire materials from oxide superconductors.

"Crows on the Wire": Intermediality in Applied Drama and Conflict Transformation--"Humanising" the Police in Northern Ireland

ERIC Educational Resources Information Center

Jennings, Matt

2016-01-01

"Crows on the Wire" (COTW) is an intermedial project deploying applied theatre, educational drama and digital performance [Dixon, S. (2007). "Digital Performance: A History of New Media in Theatre, Dance, Performance Art and Installation." Cambridge, MA: MIT Press] to explore the recent history of the peace process in Northern…

Flexural Testing of Steel Wire Composite Beams Made with Hardwire (trademark) Unidirectional Tape

DTIC Science & Technology

2003-11-18

Hardwire to carbon fabric in the panels was 85%/15% respectively. The 3XSF Hardwire/fiberglass specimens were made with a 675 yield Type 30 Owens ... Corning glass fiber incorporated into the steel wire cord as shown in Figure 3 in a proprietary co-mingling operation in the cord making process. Ply by

37 CFR 1.83 - Content of drawing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Content of drawing. 1.83... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES National Processing Provisions The Drawings § 1.83 Content of drawing. (a) The drawing in a nonprovisional application must show every feature of the...

Young Children's Drawings in Problem Solving

ERIC Educational Resources Information Center

Bakar, Kamariah Abu; Way, Jennifer; Bobis, Janette

2016-01-01

This paper explores young children's drawings (6 years old) in early number and addition activities in Malaysia. Observation, informal interviews and analysis of drawings revealed two types of drawing, and gave insight into the transitional process required for children to utilise drawings in problem solving. We argue the importance of valuing and…

SRTM is removed from Endeavour's payload bay to ease wiring inspections

NASA Technical Reports Server (NTRS)

1999-01-01

In the Orbiter Processing Facility, workers observe as an overhead crane lowers the Shuttle Radar Topography Mission (SRTM) into a payload canister. The payload on mission STS-99, SRTM was removed from orbiter Endeavour's payload bay to allow technicians access to the orbiter's midbody for planned wiring inspections. The entire fleet of orbiters is being inspected for wiring abrasions after the problem was first discovered in Columbia. Shuttle managers are reviewing several manifest options and could establish new target launch dates for the balance of 1999 next week. Shuttle Endeavour currently remains slated for launch in early October.

Web-based healthcare hand drawing management system.

PubMed

Hsieh, Sheau-Ling; Weng, Yung-Ching; Chen, Chi-Huang; Hsu, Kai-Ping; Lin, Jeng-Wei; Lai, Feipei

2010-01-01

The paper addresses Medical Hand Drawing Management System architecture and implementation. In the system, we developed four modules: hand drawing management module; patient medical records query module; hand drawing editing and upload module; hand drawing query module. The system adapts windows-based applications and encompasses web pages by ASP.NET hosting mechanism under web services platforms. The hand drawings implemented as files are stored in a FTP server. The file names with associated data, e.g. patient identification, drawing physician, access rights, etc. are reposited in a database. The modules can be conveniently embedded, integrated into any system. Therefore, the system possesses the hand drawing features to support daily medical operations, effectively improve healthcare qualities as well. Moreover, the system includes the printing capability to achieve a complete, computerized medical document process. In summary, the system allows web-based applications to facilitate the graphic processes for healthcare operations.

Impact of manual preference on directionality in children's drawings.

PubMed

Picard, Delphine

2011-01-01

The effects of handedness on directionality in drawing are already well documented in the literature, at least as far as adults are concerned. The present study investigates the impact of manual preference on directionality as seen in the drawing product and drawing process, from a developmental point of view. A total of 120 children aged 5 to 9, both right and left-handed drawers, volunteered for the study. Children were asked to draw twice from memory a set of six common objects. Results indicate that directionality in drawing product varies significantly according to manual preference in the 9-year-old children, but not in the younger age groups. The concomitant increase between 7 and 9 years of age in the use of preferred stroke directions and the impact of manual preference in the drawing process suggests that biomechanical factors might play an important role in behavioural asymmetries in drawing.

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

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

Relationship Between the Electromagnetic Wave Energy Coupled by Overhead Lines and the Radiation Source Current Explored in the Laboratory

NASA Astrophysics Data System (ADS)

Li, Xiangchao; Wan, Zhicheng

2018-04-01

In order to solve the damage and interference problems to the electronic devices, which are induced by overvoltage excited by the coupling process between lightning electromagnetic wave and overhead lines, the lightning channel is set to be equivalent to a radiant wire antenna. Based on the integration model of lightning return stroke channel, transmission line, and ground, we take advantage of the derived formula gotten from the transmission line model. By combing the theoretical and experimental methods, we conduct a comparative analysis on the coupling process between natural/simulated lightning and overhead line. Besides, we also calculate the amplitude and energy of overvoltage, which is caused by the coupling process between lightning electromagnetic wave and overhead lines. Upon these experimental results, we can draw several conclusions as follows: when the amplitude of the lightning current in the channel is between 5 kA and 41 kA, it takes on an excellent linear relation between the amplitude of overvoltage and the magnitude of the lightning current, the relation between coupling energy and magnitude of the lightning current takes on an exponential trend. When lightning wave transmits on the transmission lines, the high-order mode will be excited. Through analysis on the high-order mode's characteristics, we find that the theoretical analysis is consistent with the experimental results, which has a certain reference value to the protection on overhead lines.

Inspecting rapidly moving surfaces for small defects using CNN cameras

NASA Astrophysics Data System (ADS)

Blug, Andreas; Carl, Daniel; Höfler, Heinrich

2013-04-01

A continuous increase in production speed and manufacturing precision raises a demand for the automated detection of small image features on rapidly moving surfaces. An example are wire drawing processes where kilometers of cylindrical metal surfaces moving with 10 m/s have to be inspected for defects such as scratches, dents, grooves, or chatter marks with a lateral size of 100 μm in real time. Up to now, complex eddy current systems are used for quality control instead of line cameras, because the ratio between lateral feature size and surface speed is limited by the data transport between camera and computer. This bottleneck is avoided by "cellular neural network" (CNN) cameras which enable image processing directly on the camera chip. This article reports results achieved with a demonstrator based on this novel analogue camera - computer system. The results show that computational speed and accuracy of the analogue computer system are sufficient to detect and discriminate the different types of defects. Area images with 176 x 144 pixels are acquired and evaluated in real time with frame rates of 4 to 10 kHz - depending on the number of defects to be detected. These frame rates correspond to equivalent line rates on line cameras between 360 and 880 kHz, a number far beyond the available features. Using the relation between lateral feature size and surface speed as a figure of merit, the CNN based system outperforms conventional image processing systems by an order of magnitude.

Computer Aided Process Planning for Non-Axisymmetric Deep Drawing Products

NASA Astrophysics Data System (ADS)

Park, Dong Hwan; Yarlagadda, Prasad K. D. V.

2004-06-01

In general, deep drawing products have various cross-section shapes such as cylindrical, rectangular and non-axisymmetric shapes. The application of the surface area calculation to non-axisymmetric deep drawing process has not been published yet. In this research, a surface area calculation for non-axisymmetric deep drawing products with elliptical shape was constructed for a design of blank shape of deep drawing products by using an AutoLISP function of AutoCAD software. A computer-aided process planning (CAPP) system for rotationally symmetric deep drawing products has been developed. However, the application of the system to non-axisymmetric components has not been reported yet. Thus, the CAPP system for non-axisymmetric deep drawing products with elliptical shape was constructed by using process sequence design. The system developed in this work consists of four modules. The first is recognition of shape module to recognize non-axisymmetric products. The second is a three-dimensional (3-D) modeling module to calculate the surface area for non-axisymmetric products. The third is a blank design module to create an oval-shaped blank with the identical surface area. The forth is a process planning module based on the production rules that play the best important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing field engineers. Especially, the drawing coefficient, the punch and die radii for elliptical shape products are considered as main design parameters. The suitability of this system was verified by applying to a real deep drawing product. This CAPP system constructed would be very useful to reduce lead-time for manufacturing and improve an accuracy of products.

Children's episodic memory.

PubMed

Ghetti, Simona; Lee, Joshua

2011-07-01

Episodic memory develops during childhood and adolescence. This trajectory depends on several underlying processes. In this article, we first discuss the development of the basic binding processes (e.g., the processes by which elements are bound together to form a memory episode) and control processes (e.g., reasoning and metamemory processes) involved in episodic remembering. Then, we discuss the role of these processes in false-memory formation. In the subsequent sections, we examine the neural substrates of the development of episodic memory. Finally, we discuss atypical development of episodic memory. As we proceed through the article, we suggest potential avenues for future research. WIREs Cogni Sci 2011 2 365-373 DOI: 10.1002/wcs.114 For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.

Picturing academic learning: salutogenic and health promoting perspectives on drawings.

PubMed

Garista, Patrizia; Pocetta, Giancarlo; Lindström, Bengt

2018-05-25

More than 20 years ago an article about the use of drawings in higher education appeared in a medical journal. After that, other papers explored the possible contribution of drawings in adult education, while only very few in the field of health promotion and education. This article aims to introduce the use of drawing in this field using the salutogenic lens to think, plan and reflect on academic learning. Reflections on what salutogenesis is and what we can consider a clear application of salutogenic principles to the learning process answer a hypothetical question for the reader concerning the relationship between drawings and health promotion theories. They appear as communication tools capable of exploring meaning-making processes, capturing data that is flexible to dynamic systems, power relations, as well as emotional and latent aspects of human experience. This article proposes a connection between salutogenesis and drawings through: a theoretical framework on salutogenic learning and drawings; a teacher practice and its tools focusing the critical point on visual data analysis in a learning environment; a learner case example for knowledge and capacity building through the drawing process; and a health promotion competency-based analysis. Our case example illustrates how drawings were introduced in a post-graduate course in Health Promotion and Education and argues their strengths and weaknesses.

Validation of the FEA of a deep drawing process with additional force transmission

NASA Astrophysics Data System (ADS)

Behrens, B.-A.; Bouguecha, A.; Bonk, C.; Grbic, N.; Vucetic, M.

2017-10-01

In order to meet requirements by automotive industry like decreasing the CO2 emissions, which reflects in reducing vehicles mass in the car body, the chassis and the powertrain, the continuous innovation and further development of existing production processes are required. In sheet metal forming processes the process limits and components characteristics are defined through the process specific loads. While exceeding the load limits, a failure in the material occurs, which can be avoided by additional force transmission activated in the deep drawing process before the process limit is achieved. This contribution deals with experimental investigations of a forming process with additional force transmission regarding the extension of the process limits. Based on FEA a tool system is designed and developed by IFUM. For this purpose, the steel material HCT600 is analyzed numerically. Within the experimental investigations, the deep drawing processes, with and without the additional force transmission are carried out. Here, a comparison of the produced rectangle cups is done. Subsequently, the identical deep drawing processes are investigated numerically. Thereby, the values of the punch reaction force and displacement are estimated and compared with experimental results. Thus, the validation of material model is successfully carried out on process scale. For further quantitative verification of the FEA results the experimental determined geometry of the rectangular cup is measured optically with ATOS system of the company GOM mbH and digitally compared with external software Geomagic®QualifyTM. The goal of this paper is the verification of the transferability of the FEA model for a conventional deep drawing process to a deep drawing process with additional force transmission with a counter punch.

High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suit Gas Processing System (GPS) Carbon Dioxide Scrubber

NASA Technical Reports Server (NTRS)

Gundersen, Cynthia; Hoffman, Christopher; Munoz, Bruno; Steohenson, Timothy; Thomas, Walter

2008-01-01

In support of the GPS for the SAM instrument suite built by GSFC, a life test facility was developed to test the suitability of 80Ni-20Cr wire, 0.0056 inches in diameter, for use as a heater element for the carbon dioxide scrubber. The wire would be required to operate at 1000 C in order to attain the 800 C required for regeneration of the getter. The wire also would need to operate in the Mars atmosphere, which consists mostly of CO2 at pressures between 4 and 12 torr. Data on the high temperature degradation mechanism of 80Ni-20Cr in low pressure CO2, together with the effects of thermal cycling, were unknown. In addition, the influence of work hardening of the wire during assembly and the potential for catastrophic grain growth also were unknown. Verification of the wire reliability as defined by the mission goals required the construction of a test facility that would accurately simulate the duty cycles in a simulated Mars atmosphere. The experimental set-up, along with the test protocol and results will be described.

Control of occupational exposure to hexavalent chromium and ozone in tubular wire arc-welding processes by replacement of potassium by lithium or by addition of zinc.

PubMed

Dennis, John H; French, Michael J; Hewitt, Peter J; Mortazavi, Seyed B; Redding, Christopher A J

2002-01-01

Hexavalent chromium [Cr(VI)] and ozone are produced in many arc-welding processes. Cr(VI) is formed when welding with chromium-containing alloys and is a suspected carcinogen. Ozone is formed by the action of ultraviolet light from the arc on oxygen and can cause severe irritation to the eyes and mucous membranes. Previous work has demonstrated that reduction of sodium and potassium in manual metal arc-welding electrodes leads to substantial reductions in Cr(VI) concentrations in the fume as well as a reduction in the fume formation rate. In this paper replacement of potassium by lithium in a tubular wire welding electrode (self-shielding flux-cored) is shown to give reductions in Cr(VI) concentrations and fume formation rates. Previous work has also demonstrated that use of a tubular wire (metal cored) containing 1% zinc can, under certain conditions, result in a reduction in Cr(VI) formation rate and in ozone concentration near the arc but with a rise in the total fume formation rate. The effects of different shield gases and different levels of zinc are examined. An experimental chromium-containing tubular wire with 1% zinc was used with the following shield gases: argon, Argoshield 5, Argoshield 20, Helishield 101, Ar + 2% CO2, Ar + 5% CO2, Ar + 1% O2 and Ar + 2% O2. The wire gave > 98% reduction in Cr(VI) formation rate compared to the control wire provided the shield gas contained no oxygen. When the shield gas did contain oxygen, 1% zinc enhanced Cr(VI) formation rate, resulting in more than double the rates measured when welding with the control wire. Experiments with zinc concentrations, from 0.018 to 0.9% using Helishield 101, gave results indicating that there is an optimum zinc concentration from the point of view of Cr(VI) reduction. Implications of the use of lithium or zinc on the overall exposure risk are discussed.

The shear strength of three-dimensional capillary-porous titanium coatings for intraosseous implants.

PubMed

Kalita, V I; Komlev, D I; Komlev, V S; Radyuk, A A

2016-03-01

A plasma spraying process for the deposition of three-dimensional capillary-porous titanium coatings using a wire has been developed. In this process, two additional dc arcs are discharged between plasmatron and both the wire and the substrate, resulting in additional activation of the substrate and the particles, particularly by increasing their temperature. The shear strength of the titanium coating with 46% porosity is 120.6 MPa. A new procedure for estimating the shear strength of porous coatings has been developed. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of Auxiliary Preheating of the Filler Wire on Quality of Gas Metal Arc Stainless Steel Claddings

NASA Astrophysics Data System (ADS)

Shahi, Amandeep S.; Pandey, Sunil

2008-02-01

Weld cladding is a process for producing surfaces with good corrosion resistant properties by means of depositing/laying of stainless steels on low-carbon steel components with an objective of achieving maximum economy and enhanced life. The aim of the work presented here was to investigate the effect of auxiliary preheating of the solid filler wire in mechanized gas metal arc welding (GMAW) process (by using a specially designed torch to preheat the filler wire independently, before its emergence from the torch) on the quality of the as-welded single layer stainless steel overlays. External preheating of the filler wire resulted in greater contribution of arc energy by resistive heating due to which significant drop in the main welding current values and hence low dilution levels were observed. Metallurgical aspects of the as welded overlays such as chemistry, ferrite content, and modes of solidification were studied to evaluate their suitability for service and it was found that claddings obtained through the preheating arrangement, besides higher ferrite content, possessed higher content of chromium, nickel, and molybdenum and lower content of carbon as compared to conventional GMAW claddings, thereby giving overlays with superior mechanical and corrosion resistance properties. The findings of this study not only establish the technical superiority of the new process, but also, owing to its productivity-enhanced features, justify its use for low-cost surfacing applications.

Progress in second-generation HTS wire development and manufacturing

NASA Astrophysics Data System (ADS)

Selvamanickam, V.; Chen, Y.; Xiong, X.; Xie, Y.; Zhang, X.; Rar, A.; Martchevskii, M.; Schmidt, R.; Lenseth, K.; Herrin, J.

2008-09-01

2007 has marked yet another year of continued rapid progress in developing and manufacturing high-performance, long-length second-generation (2G) HTS wires at high speeds. Using ion beam assisted deposition (IBAD) MgO and associated buffer sputtering processes, SuperPower has now exceeded piece lengths of 1000 m of fully buffered tape reproducibly with excellent in-plane texture of 6-7 degrees and uniformity of about 2%. These kilometer lengths are produced at high speeds of about 350 m/h of 4 mm wide tape. In combination with metal organic chemical vapor deposition (MOCVD), 2G wires up to single piece lengths to 790 m with a minimum critical current value of 190 A/cm corresponding to a Critical current × Length performance of 150,100 Am have been achieved. Tape speeds up to 180 m/h have been reached MOCVD while maintaining critical currents above 200 A/cm in 100+ m lengths. Thick film MOCVD technology has been transitioned to Pilot manufacturing system where a minimum critical current of 320 A/cm has been demonstrated over a length of 155 m processed at a speed of 70 m/h in 4 mm width. Finally, nearly 10,000 m of 2G wire has been produced, exhaustively tested, and delivered to the Albany Cable project. The average minimum critical current of the wire delivered in 225 segments of 43-44 m is 70 A in 4 mm widths. A 30 m cable has been fabricated with this wire by Sumitomo Electric and has been installed in the power grid of National Grid in downtown Albany and is the world’s first 2G device installed in the grid.

Minimally invasive guidewireless, navigated pedicle screw placement: a technical report and case series.

PubMed

Smith, Brandon W; Joseph, Jacob R; Kirsch, Michael; Strasser, Mary Oakley; Smith, Jacob; Park, Paul

2017-08-01

OBJECTIVE Percutaneous pedicle screw insertion (PPSI) is a mainstay of minimally invasive spinal surgery. Traditionally, PPSI is a fluoroscopy-guided, multistep process involving traversing the pedicle with a Jamshidi needle, placement of a Kirschner wire (K-wire), placement of a soft-tissue dilator, pedicle tract tapping, and screw insertion over the K-wire. This study evaluates the accuracy and safety of PPSI with a simplified 2-step process using a navigated awl-tap followed by navigated screw insertion without use of a K-wire or fluoroscopy. METHODS Patients undergoing PPSI utilizing the K-wire-less technique were identified. Data were extracted from the electronic medical record. Complications associated with screw placement were recorded. Postoperative radiographs as well as CT were evaluated for accuracy of pedicle screw placement. RESULTS Thirty-six patients (18 male and 18 female) were included. The patients' mean age was 60.4 years (range 23.8-78.4 years), and their mean body mass index was 28.5 kg/m 2 (range 20.8-40.1 kg/m 2 ). A total of 238 pedicle screws were placed. A mean of 6.6 pedicle screws (range 4-14) were placed over a mean of 2.61 levels (range 1-7). No pedicle breaches were identified on review of postoperative radiographs. In a subgroup analysis of the 25 cases (69%) in which CT scans were performed, 173 screws were assessed; 170 (98.3%) were found to be completely within the pedicle, and 3 (1.7%) demonstrated medial breaches of less than 2 mm (Grade B). There were no complications related to PPSI in this cohort. CONCLUSIONS This streamlined 2-step K-wire-less, navigated PPSI appears safe and accurate and avoids the need for radiation exposure to surgeon and staff.

NAAMES Photo Essay

NASA Image and Video Library

2017-12-08

Inside the expansive cargo plane visitor’s immediately discover that that every available surface has been utilized to maximize the plane as a flying laboratory. Wires, conduits and specialized hardware take up nearly every inch of the cabin area. --- The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) is a five year investigation to resolve key processes controlling ocean system function, their influences on atmospheric aerosols and clouds and their implications for climate. Michael Starobin joined the NAAMES field campaign on behalf of Earth Expeditions and NASA Goddard Space Flight Center’s Office of Communications. He presented stories about the important, multi-disciplinary research being conducted by the NAAMES team, with an eye towards future missions on the NASA drawing board. This is a NAAMES photo essay put together by Starobin, a collection of 49 photographs and captions. Photo and Caption Credit: Michael Starobin NASA image use policy NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Recent advances in theoretical and numerical studies of wire array Z-pinch in the IAPCM

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

Ding, Ning, E-mail: ding-ning@iapcm.ac.cn; Zhang, Yang, E-mail: ding-ning@iapcm.ac.cn; Xiao, Delong, E-mail: ding-ning@iapcm.ac.cn

2014-12-15

Fast Z-pinch has produced the most powerful X-ray radiation source in laboratory and also shows the possibility to drive inertial confinement fusion (ICF). Recent advances in wire-array Z-pinch researches at the Institute of Applied Physics and Computational Mathematics are presented in this paper. A typical wire array Z-pinch process has three phases: wire plasma formation and ablation, implosion and the MRT instability development, stagnation and radiation. A mass injection model with azimuthal modulation coefficient is used to describe the wire initiation, and the dynamics of ablated plasmas of wire-array Z-pinches in (r, θ) geometry is numerically studied. In the implosionmore » phase, a two-dimensional(r, z) three temperature radiation MHD code MARED has been developed to investigate the development of the Magneto-Rayleigh-Taylor(MRT) instability. We also analyze the implosion modes of nested wire-array and find that the inner wire-array is hardly affected before the impaction of the outer wire-array. While the plasma accelerated to high speed in the implosion stage stagnates on the axis, abundant x-ray radiation is produced. The energy spectrum of the radiation and the production mechanism are investigated. The computational x-ray pulse shows a reasonable agreement with the experimental result. We also suggest that using alloyed wire-arrays can increase multi-keV K-shell yield by decreasing the opacity of K-shell lines. In addition, we use a detailed circuit model to study the energy coupling between the generator and the Z-pinch implosion. Recently, we are concentrating on the problems of Z-pinch driven ICF, such as dynamic hohlraum and capsule implosions. Our numerical investigations on the interaction of wire-array Z-pinches on foam convertors show qualitative agreements with experimental results on the “Qiangguang I” facility. An integrated two-dimensional simulation of dynamic hohlraum driven capsule implosion provides us the physical insights of wire-array plasma acceleration, shock generation and production, hohlraum formation, radiation ablation and fuel compression.« less

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

Kim, Joshua, E-mail: joshuk7@uci.edu; Park, Sun-Jun; Nguyen, Thao

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. Themore » 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.« less

Breckinridge Project, initial effort

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

None

1982-01-01

Report V, Volume 4 provides descriptions, data, and drawings pertaining to Instrument and Plant Air Systems (Plant 36), Telecommunication Systems (Plant 37), Inert Gas Systems (Plant 38), Purge and Flush Oil Systems (Plant 39), Site Development and Roads (Plant 40), Buildings (Plant 41), Solid Waste Management (Plant 42), and Landfill (Plant 44). Instrument and Plant Air Systems (Plant 36) includes all equipment and piping necessary to supply instrument and utility air to the process plants and offsite facilities. Telecommunication Systems (Plant 37) includes the equipment and wiring for: communication throughout the facility; communication between plant data processing systems and offsitemore » computing facilities; and communication with transportation carriers. Inert Gas Systems (Plant 38) provides high purity and low purity nitrogen streams for plant startup and normal operation. Purge and Flush Oil Systems (Plant 39) provides purge and flush oils to various plants. Site Development and Roads (Plant 40) provides site leveling, the addition of roads, fencing, and drainage, and the placement of fills, pilings, footings, and foundations for plants. Buildings (Plant 41) provides buildings for equipment and for personnel, including utilities, lighting, sanitary facilities, heating, air conditioning, and ventilation. Solid Waste Management (Plant 42) identifies, characterizes, segregates, and transports the various types of solid wastes to either Landfill (Plant 44) or outside disposal sites. Landfill (Plant 44) provides disposal of both nonhazardous and hazardous solid wastes. Information is included (as applicable) for each of the eight plants described.« less

Electrical Resistivity of Wire Arc Sprayed Zn and Cu Coatings for In-Mold-Metal-Spraying

NASA Astrophysics Data System (ADS)

Bobzin, K.; Öte, M.; Knoch, M. A.; Liao, X.; Hopmann, Ch; Ochotta, P.

2018-06-01

Electrical functionalities can be integrated into plastic parts by integrating thermally sprayed metal coatings into the non-conductive base material. Thermally sprayed conducting tracks for power and signal transmission are one example. In this case, the electrical resistance or resistivity of the coatings should be investigated. Therefore, the electrical resistivity of wire arc sprayed Zn and Cu coatings has been investigated. In case of Zn coatings, spray distance, gas pressure and wire diameter could be identified as significant influencing parameters on the electrical resistivity. In contrast, process gas, gas pressure and voltage do have a significant influence on the electrical resistivity of Cu coatings. Through the use of the In-Mold-Metal-Spraying method (IMMS), thermal degradation can be avoided by transferring thermally sprayed coating from a mold insert onto the plastic part. Therefore, the influence of the transfer process on the electrical resistance of the coatings has also been investigated.

Advanced development of TFA-MOD coated conductors

NASA Astrophysics Data System (ADS)

Rupich, M. W.; Li, X.; Sathyamurthy, S.; Thieme, C.; Fleshler, S.

2011-11-01

American Superconductor is manufacturing 2G wire for initial commercial applications. The 2G wire properties satisfy the requirements for these initial projects; however, improvements in the critical current, field performance and cost are required to address the broad range of potential commercial and military applications. In order to meet the anticipated the performance and cost requirements, AMSC's R&D effort is focused on two major areas: (1) higher critical current and (2) enhanced flux pinning. AMSC's current 2G production wire, designed around a 0.8 μm thick YBCO layer deposited by a Metal Organic Deposition (MOD) process, carries a critical current in the range of 200-300 A/cm-w (77 K, sf). Achieving higher critical current requires increasing the thickness of the YBCO layer. This paper describes recent progress at AMSC on increasing the critical current of MOD-YBCO films using processes compatible with low-cost, high-rate manufacturing.

76 FR 76035 - Amendment to the International Traffic in Arms Regulations: Additional Method of Electronic...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-06

... U.S.C. Chapter 35. List of Subjects in 22 CFR Parts 122 and 129 Arms and munitions, Exports... House (ACH) and Federal Reserve Wire Network (FedWire) are electronic networks used to process financial... electronic payment. Electronic payments must be in U.S. currency and must be payable through a U.S. financial...

Manufacturing and quality control of interconnecting wire harnesses, Volume 4

NASA Technical Reports Server (NTRS)

1972-01-01

The document covers interconnecting wire harnesses defined in the design standard, including type 8, flat conductor cable. Volume breadth covers installations of groups of harnesses in a major assembly and the associated post installation inspections and electrical tests. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into this document.

Plated wire memory subsystem

NASA Technical Reports Server (NTRS)

Reynolds, L.; Tweed, H.

1972-01-01

The work performed entailed the design, development, construction and testing of a 4000 word by 18 bit random access, NDRO plated wire memory for use in conjunction with a spacecraft imput/output unit and central processing unit. The primary design parameters, in order of importance, were high reliability, low power, volume and weight. A single memory unit, referred to as a qualification model, was delivered.

Tribological behaviour of orthodontic archwires under dry and wet sliding conditions in-vitro. II--Wear patterns.

PubMed

Berradja, Abdenacer; Willems, Guy; Celis, Jean-Pierre

2006-05-01

To evaluate the wear patterns of orthodontic archwires in dry and wet conditions in-vitro. The patterns of wear of stainless steel and NiTi orthodontic archwires were investigated with a fretting wear tribometer fitted with an alumina ball. The tribometer was operated at 23 degrees C in three different environments: ambient air with 50 per cent relative humidity (RH), 0.9 wt. per cent sodium chloride solution and deionised water. Differences in the wear characteristics of the archwires were investigated by scanning electron microscopy. Energy Dispersive X-ray Analysis and Inductively Coupled Plasma Analysis were used to investigate the surface composition of the wires, the wear debris generated during fretting and the corrosion products in the test solutions. Both archwire materials were degraded by oxidational wear in ambient air. The NiTi wires were more resistant to wear than the stainless steel wires. In the aqueous media the stainless steel wires were degraded by abrasive wear, while the NiTi wires were degraded by adhesive wear. In ambient air with 50 per cent RH, NiTi wires were more resistant to wear than stainless steel wires. Both archwire materials exhibited higher wear rates in the solutions than in air, indicating some synergism between the wear and corrosion processes. In the solutions the stainless steel archwires had a much lower corrosion-wear resistance than the NiTi archwires.

Influence of the Manufacturing Process on Defects in the Galvanized Coating of High Carbon Steel Wires.

PubMed

Gelfi, Marcello; Solazzi, Luigi; Poli, Sandro

2017-03-06

This study is a detailed failure analysis of galvanized high carbon steel wires, which developed coating cracks during the torsion test performed as a quality control at the end of the manufacturing process. Careful visual inspections showed that the cracks are already present in the coating before the torsion test. In order to explain the origin of these cracks, systematic metallographic investigations were performed by means of optical and scanning electron microscope on both the wires and the rods that have been cold drawn to produce the wire. The chemical composition of the galvanized coatings was evaluated by means of energy dispersive spectroscopy. Micro bidimensional X-ray diffraction experiments were also performed to measure the residual stresses in the galvanized coating. The results showed that the failure is related to two main factors: the relatively high content of silicon in the steel and the unsuitable cooling rate of the rods at the exit from the galvanizing bath. The mechanism proposed to explain the origin of the defects was supported by Finite Elements Methods simulations and verified with in-plant tests. The proper countermeasures were then applied and the problem successfully solved.

Magnetization Dynamics of Amorphous Ribbons and Wires Studied by Inductance Spectroscopy

PubMed Central

Betancourt, Israel

2010-01-01

Inductance spectroscopy is a particular formulation variant of the well known complex impedance formalism typically used for the electric characterization of dielectric, ferroelectric, and piezoelectric materials. It has been successfully exploited as a versatile tool for characterization of the magnetization dynamics in amorphous ribbons and wires by means of simple experiments involving coils for sample holding and impedance analyzer equipment. This technique affords the resolution of the magnetization processes in soft magnetic materials, in terms of reversible deformation of pinned domain walls, domain wall displacements and spin rotation, for which characteristic parameters such as the alloy initial permeability and the relaxation frequencies, indicating the dispersion of each process, can be defined. Additionally, these parameters can be correlated with chemical composition variation, size effects and induced anisotropies, leading to a more physical insight for the understanding of the frequency dependent magnetic response of amorphous alloys, which is of prime interest for the development of novel applications in the field of telecommunication and sensing technologies. In this work, a brief overview, together with recent progress on the magnetization dynamics of amorphous ribbons, wires, microwires and biphase wires, is presented and discussed for the intermediate frequency interval between 10 Hz and 13 MHz. PMID:28879975

Seebeck Changes Due to Residual Cold-Work and Reversible Effects in Type K Bare-Wire Thermocouples

NASA Astrophysics Data System (ADS)

Webster, E. S.

2017-09-01

Type K thermocouples are the most commonly used thermocouple for industrial measurements because of their low cost, wide temperature range, and durability. As with all base-metal thermocouples, Type K is made to match a mathematical temperature-to-emf relationship and not a prescribed alloy formulation. Because different manufacturers use varying alloy formulations and manufacturing techniques, different Type K thermocouples exhibit a range of drift and hysteresis characteristics, largely due to ordering effects in the positive (K+) thermoelement. In this study, these effects are assessed in detail for temperatures below 700°C in the Type K wires from nine manufacturers. A linear gradient furnace and a high-resolution homogeneity scanner combined with the judicious use of annealing processes allow measurements that separately identify the effects of cold-work, ordering, and oxidation to be made. The results show most K+ alloys develop significant errors, but the magnitudes of the contributions of each process vary substantially between the different K+ wires. In practical applications, the measurement uncertainties achievable with Type K therefore depend not only on the wire formulation but also on the temperature, period of exposure, and, most importantly, the thermal treatments prior to use.

Study of Silicidation Process of Tungsten Catalyzer during Silicon Film Deposition in Catalytic Chemical Vapor Deposition

NASA Astrophysics Data System (ADS)

Honda, Kazuhiro; Ohdaira, Keisuke; Matsumura, Hideki

2008-05-01

In catalytic chemical vapor deposition (Cat-CVD), often called hot-wire CVD, source gases are decomposed by catalytic cracking reactions with heated catalyzing metal wires. In the case of silicon (Si) film deposition, such metal wires are often converted to silicide, which shortens the lifetime of catalyzing wires. As a catalyzer, tungsten (W) is widely used. Thus, the process of silicidation of a W catalyzer at temperatures over 1650 °C, which is the temperature used in Cat-CVD for Si film deposition, was studied extensively in various experiments. It is found that two phases of tungsten-silicide, WSi2 and W5Si3, are formed at this temperature, and that the radiation emissivity of WSi2 is 1.2 to 1.7 times higher than that of W5Si3 and pure W. The increase of surface emissivity due to the formation of WSi2 decreases the catalyzer surface temperature which induces further growth of the tungsten-silicide layer. It is also found that the suppression of WSi2 formation by elevating catalyzer temperatures over 1750 °C is a key to extending the lifetime of the W catalyzer in Cat-CVD.

Influence of the Manufacturing Process on Defects in the Galvanized Coating of High Carbon Steel Wires

PubMed Central

Gelfi, Marcello; Solazzi, Luigi; Poli, Sandro

2017-01-01

This study is a detailed failure analysis of galvanized high carbon steel wires, which developed coating cracks during the torsion test performed as a quality control at the end of the manufacturing process. Careful visual inspections showed that the cracks are already present in the coating before the torsion test. In order to explain the origin of these cracks, systematic metallographic investigations were performed by means of optical and scanning electron microscope on both the wires and the rods that have been cold drawn to produce the wire. The chemical composition of the galvanized coatings was evaluated by means of energy dispersive spectroscopy. Micro bidimensional X-ray diffraction experiments were also performed to measure the residual stresses in the galvanized coating. The results showed that the failure is related to two main factors: the relatively high content of silicon in the steel and the unsuitable cooling rate of the rods at the exit from the galvanizing bath. The mechanism proposed to explain the origin of the defects was supported by Finite Elements Methods simulations and verified with in-plant tests. The proper countermeasures were then applied and the problem successfully solved. PMID:28772623

Shape memory alloy wires turn composites into smart structures: II. Manufacturing and properties

NASA Astrophysics Data System (ADS)

Michaud, Veronique J.; Schrooten, Jan; Parlinska, Magdelena; Gotthardt, Rolf; Bidaux, Jacques-Eric

2002-07-01

The manufacturing route and resulting properties of adaptive composites are presented in the second part of this European project report. Manufacturing was performed using a specially designed frame to pre-strain the SMA wires, embed them into Kevlar-epoxy prepregs, and maintain them during the curing process in an autoclave. Composite compounds were then tested for strain response, recovery stress response in a clamped-clamped configuration, as well as vibrational response. Through the understanding of the transformational behavior of constrained SMA wires, interesting and unique functional properties of SMA composites could be measured, explained and modeled. Large recovery stresses and as a consequence, a change in vibrational response in a clamped- clamped condition, or a reversible shape change in a free standing condition, could be generated by the SMA composites in a controllable way. These properties were dependent on composite design aspects and exhibited a reproducible and stable behavior, provided that the properties of the matrix, of the wires and the processing route were carefully optimized. In conclusion, the achievements of this effort in areas such as thermomechanics, transformational and vibrational behavior and durability of SMA based composites provide a first step towards a reliable materials design, and potentially an industrial application.

8-Step Model Drawing: Singapore's Best Problem-Solving MATH Strategies

ERIC Educational Resources Information Center

Hogan, Bob; Forsten, Char

2007-01-01

In this book, Bob Hogan and Char Forsten introduce American mathematics educators to the model drawing process adapted from the much-acclaimed Singapore approach. They explain what model drawing is and why it's such an effective problem-solving tool. They show exactly how teachers can guide their students through the process, tell which key points…

DEVELOPMENT OF IMPROVED FABRICATION METHODS, PROCESS AND TECHNIQUES FOR PRODUCING TYPICAL AIRCRAFT SHAPES FROM BERYLLIUM. Interim Technical Documentary Progress Report for the Period ending October 31, 1962

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

Jenkins, R.G.; Siergiej, J.M.

1962-12-28

In a program to develop a complete manufacturing process for ihe production of beryllium channels, techniques are being sought for drawing to obtain a flnal product meeting specifications more rigorous than are obtainable by direct extrusion. Progress in designing and procuring the special tooling required to draw complex shapes at elevated temperature is described, and the flrst set of draw dies is evaluated with respect to design and quality. Three experimental draw attempts have been made on U-channels, in addition to draw tests on flats. (auth)

Development of in-situ control diagnostics for application of epitaxial superconductor and buffer layers

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

B.C. Winkleman; T.V. Giel; Jason Cunningham

1999-07-30

The recent achievements of critical currents in excess of 1 x 10{sup 6} amp/cm{sup 2} at 77 K in YBCO deposited over suitably textured buffer/substrate composites have stimulated interest in the potential fabrication of these coated conductors as wire. Numerous approaches and manufacturing schemes for producing coated conductor wire are currently being developed. Recently, under the US DOE's sponsorship, the University of Tennessee Space Institute performed an extensive evaluation of leading coated conductor processing options. In general, it is their feeling that the science and chemistry that are being developed in the coated conductor wire program now need proper engineeringmore » evaluation to define the most viable options for a commercial fabrication process. All fabrication processes will need process control measurements. This report provides a specific review of the needs and available technologies for process control for many of the coated conductor processing options. This report also addresses generic process monitoring areas in which additional research and development is needed. The concentration is on the two different approaches for obtaining the textured substrates that have been identified as viable candidates. These are the Los Alamos National Laboratory's ion-beam assisted deposition, called IBAD, to obtain a highly textured yttria-stabilized zirconia (YSZ) buffer on nickel alloy strips, and Oak Ridge National Laboratory's rolling assisted, bi-axially textured substrate option called RABiTS{trademark}.« less

Numerical Simulation of Hydro-mechanical Deep Drawing — A Study on the Effect of Process Parameters on Drawability and Thickness Variation

NASA Astrophysics Data System (ADS)

Singh, Swadesh Kumar; Kumar, D. Ravi

2005-08-01

Hydro-mechanical deep drawing is a process for producing cup shaped parts with the assistance of a pressurized fluid. In the present work, numerical simulation of the conventional and counter pressure deep drawing processes has been done with the help of a finite element method based software. Simulation results were analyzed to study the improvement in drawability by using hydro-mechanical processes. The thickness variations in the drawn cups were analyzed and also the effect of counter pressure and oil gap on the thickness distribution was studied. Numerical simulations were also used for the die design, which combines both drawing and ironing processes in a single operation. This modification in the die provides high drawability, facilitates smooth material flow, gives more uniform thickness distribution and corrects the shape distortion.

Very-high thermal and electrical conductivity in overpressure-processed Bi2Sr2CaCu2O8+x wires

NASA Astrophysics Data System (ADS)

Bonura, M.; Avitabile, F.; Barth, C.; Jiang, J.; Larbalestier, D.; Fête, A.; Leo, A.; Bottura, L.; Senatore, C.

2018-05-01

The residual-resistivity ratio (RRR) of the normal-metal matrix is a key parameter for the electrical and thermal stability of technical superconductors. In Bi2Sr2CaCu2 {{{O}}}8+x (Bi-2212) round wires, the precursor powders are embedded in a Ag matrix without any diffusion barrier, and elemental diffusion from the superconducting filaments into the Ag might be expected to contaminate the matrix during the melt processing required for high critical current density development. This work shows that the overpressure processing, which is adopted to enhance the critical current performance, improves the thermal and electrical conductivities of the conductor, too. In the case of wires reacted with a standard processing performed in 1 bar O2, the RRR of the Ag matrix is about 90, in spite of the simple conductor design that does not include diffusion barriers. Increasing the total reaction pressure to 100 bar improves the RRR to about 200. The differences in RRR reflect on the thermal conductivity of the whole conductor, which has been investigated in magnetic fields up to 19 T.

Hydrated Excess Protons Can Create Their Own Water Wires.

PubMed

Peng, Yuxing; Swanson, Jessica M J; Kang, Seung-gu; Zhou, Ruhong; Voth, Gregory A

2015-07-23

Grotthuss shuttling of an excess proton charge defect through hydrogen bonded water networks has long been the focus of theoretical and experimental studies. In this work we show that there is a related process in which water molecules move ("shuttle") through a hydrated excess proton charge defect in order to wet the path ahead for subsequent proton charge migration. This process is illustrated through reactive molecular dynamics simulations of proton transport through a hydrophobic nanotube, which penetrates through a hydrophobic region. Surprisingly, before the proton enters the nanotube, it starts "shooting" water molecules into the otherwise dry space via Grotthuss shuttling, effectively creating its own water wire where none existed before. As the proton enters the nanotube (by 2-3 Å), it completes the solvation process, transitioning the nanotube to the fully wet state. By contrast, other monatomic cations (e.g., K(+)) have just the opposite effect, by blocking the wetting process and making the nanotube even drier. As the dry nanotube gradually becomes wet when the proton charge defect enters it, the free energy barrier of proton permeation through the tube via Grotthuss shuttling drops significantly. This finding suggests that an important wetting mechanism may influence proton translocation in biological systems, i.e., one in which protons "create" their own water structures (water "wires") in hydrophobic spaces (e.g., protein pores) before migrating through them. An existing water wire, e.g., one seen in an X-ray crystal structure or MD simulations without an explicit excess proton, is therefore not a requirement for protons to transport through hydrophobic spaces.

SRTM is removed from Endeavour's payload bay to ease wiring inspections

NASA Technical Reports Server (NTRS)

1999-01-01

Inside orbiter Endeavour's payload bay, a crane lifts the Shuttle Radar Topography Mission (SRTM) for its transfer out of the orbiter to a payload canister. The payload on mission STS-99, SRTM is being removed to allow technicians access to the orbiter's midbody for planned wiring inspections. Endeavour is in the Orbiter Processing Facility. The entire fleet of orbiters is being inspected for wiring abrasions after the problem was first discovered in Columbia. Shuttle managers are reviewing several manifest options and could establish new target launch dates for the balance of 1999 next week. Shuttle Endeavour currently remains slated for launch in early October.

Wire electric-discharge machining and other fabrication techniques

NASA Technical Reports Server (NTRS)

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.

Magnetization mechanisms in ordered arrays of polycrystalline Fe100-xCox nanowires

NASA Astrophysics Data System (ADS)

Viqueira, M. S.; Bajales, N.; Urreta, S. E.; Bercoff, P. G.

2015-05-01

Magnetization reversal processes and coercivity mechanisms in polycrystalline Fe100-xCox nanowire arrays, resulting from an AC electrodeposition process, are investigated. The array coercivity is described on the basis of polarization reversal mechanisms operating in individual wires, under the effect of inter-wire dipolar interactions described by a mean field approximation. For individual wires, a reversal mechanism involving the nucleation and further expansion of domain-wall like spin configuration is considered. The wires have a mean grain size larger than both the nanowire diameter and the exchange length, so localized and non-cooperative nucleation modes are considered. As the Co content increases, the alloy saturation polarization gradually decreases, but the coercive field and the relative remanence of the arrays increase, indicating that they are not controlled by the shape anisotropy in all the composition range. The coercive field dependence on the angle between the applied field and the wire long axis is not well described by reversal mechanisms involving nucleation and further displacement of neither vortex nor transverse ideal domain walls. On the contrary, the angular dependence of the coercive field observed at room temperature is well predicted by a model considering nucleation of inverse domains by localized curling, in regions smaller than the grain size, exhibiting quite small aspect ratios as compared to those of the entire nanowire. In arrays with higher Co contents, a transition from an initial (small angle) localized curling nucleation mechanism to another one, involving localized coherent rotation is observed at about π/4.

Wind Tunnel Measurements of Turbulent Boundary Layer over Hypothetical Urban Roughness Elements

NASA Astrophysics Data System (ADS)

Ho, Y. K.; Liu, C. H.

2012-04-01

Urban morphology affects the near-ground atmospheric boundary layer that in turn modifies the wind flows and pollutant dispersion over urban areas. A number of numerical models (large-eddy simulation, LES and k-ɛ turbulence models) have been developed to elucidate the transport processes in and above urban street canyons. To complement the modelling results, we initiated a wind tunnel study to examine the influence of idealized urban roughness on the flow characteristics and pollutant dispersion mechanism over 2D idealized street canyons placed in cross flows. Hot-wire anemometry (HWA) was employed in this study to measure the flows over 2D street canyons in the wind tunnel in our university. Particular focus in the beginning stage was on the fabrication of hot-wire probes, data acquisition system, and signal processing technique. Employing the commonly adopted hot-wire universal function, we investigated the relationship in between and developed a scaling factor which could generalize the output of our hot-wire probes to the standardized one as each hot-wire probes has its unique behaviour. Preliminary experiments were performed to measure the wind flows over street canyons of unity aspect ratio. Vertical profiles of the ensemble average velocity and fluctuations at three different segments over the street canyons were collected. The results were then compared with our LES that show a good argument with each other. Additional experiments are undertaken to collect more data in order to formulate the pollutant dispersion mechanism of street canyons and urban areas.

Wire Array Solar Cells: Fabrication and Photoelectrochemical Studies

NASA Astrophysics Data System (ADS)

Spurgeon, Joshua Michael

Despite demand for clean energy to reduce our addiction to fossil fuels, the price of these technologies relative to oil and coal has prevented their widespread implementation. Solar energy has enormous potential as a carbon-free resource but is several times the cost of coal-produced electricity, largely because photovoltaics of practical efficiency require high-quality, pure semiconductor materials. To produce current in a planar junction solar cell, an electron or hole generated deep within the material must travel all the way to the junction without recombining. Radial junction, wire array solar cells, however, have the potential to decouple the directions of light absorption and charge-carrier collection so that a semiconductor with a minority-carrier diffusion length shorter than its absorption depth (i.e., a lower quality, potentially cheaper material) can effectively produce current. The axial dimension of the wires is long enough for sufficient optical absorption while the charge-carriers are collected along the shorter radial dimension in a massively parallel array. This thesis explores the wire array solar cell design by developing potentially low-cost fabrication methods and investigating the energy-conversion properties of the arrays in photoelectrochemical cells. The concept was initially investigated with Cd(Se, Te) rod arrays; however, Si was the primary focus of wire array research because its semiconductor properties make low-quality Si an ideal candidate for improvement in a radial geometry. Fabrication routes for Si wire arrays were explored, including the vapor-liquid-solid growth of wires using SiCl4. Uniform, vertically aligned Si wires were demonstrated in a process that permits control of the wire radius, length, and spacing. A technique was developed to transfer these wire arrays into a low-cost, flexible polymer film, and grow multiple subsequent arrays using a single Si(111) substrate. Photoelectrochemical measurements on Si wire array/polymer composite films showed that their energy-conversion properties were comparable to those of an array attached to the growth substrate. High quantum efficiencies were observed relative to the packing density of the wires, particularly with illumination at high angles of incidence. The results indicate that an inexpensive, solid-state Si wire array solar cell is possible, and a plan is presented to develop one.

Processing, Structural Characterization and Comparative Studies on Uniaxial Tensile Properties of a New Type of Porous Twisted Wire Material

PubMed Central

Wu, Fei; Zhou, Zhaoyao; Duan, Liuyang; Xiao, Zhiyu

2015-01-01

A self-developed rotary multi-cutter device cuts stainless steel wire ropes into segments to fabricate twisted wires. Stainless steel porous twisted wire materials (PTWMs) with a spatial composite intertexture structure are produced by the compaction and subsequent vacuum solid-phase sintering of twisted wires. The stainless steel PTWMs show two types of typical uniaxial tensile failure modes, i.e., a 45° angle fracture mode and an auxetic failure mode (the PTWMs expand along the direction perpendicular to the tension). The effects of the sintering parameters, porosities, wire diameters, and sampling direction on the tensile properties of the PTWMs are carefully investigated. By increasing the sintering temperature from 1130 °C to 1330 °C, the tensile strength of the PTWMs with 70% target porosity increased from 7.7 MPa to 28.6 MPa and the total failure goes down to 50%. When increasing the sintering time from 90 min to 150 min, the tensile strength increases from 12.4 MPa to 19.1 MPa and the total failure elongation drops to 78.6%. The tensile strength of the PTWMs increases from 28.9 MPa to 112.7 MPa with decreasing porosity from 69.5% to 46.0%, and the total failure elongation also increases from 14.8% to 40.7%. The tensile strength and the failure strain of the PTWMs with fine wires are higher than those of the PTWMs with coarse wires under the same porosity. Sampling direction has a small influence on the tensile properties of the PTWMs. PMID:28793526

Hot-wire Laser Welding of Deep and Wide Gaps

NASA Astrophysics Data System (ADS)

Näsström, J.; Frostevarg, J.; Silver, T.

Heavy section Gas Metal Arc Welding (GMAW) usually requires special edge preparation and several passes. One alternative for increased performance is Laser Arc Hybrid Welding (LAHW). For very thick sheets however, imperfections like root drops or solidification cracks can occur. In this study, other techniques are also studied, including multi-pass filling of deep gaps with wire deposition. A laser is then used to melt the filler and base material. The hot- and cold wire laser welding processes are highly sensitive to wire-laser positioning, where controlled melting of the wire is essential. Apart from a comprehensive literature survey, preliminary experiments were also performed in order to find a novel method variant that can successfully fill deep and wide gaps. The method applied uses a defocused laser that generates the melt pool. A resistance heated wire is fed into the melt pool front in a leading position. This is similar to additive manufacturing techniques such as laser direct metal deposition with wire. A layer height of several millimeters can be achieved and rather low laser power can be chosen. The preliminary experiments were observed using high speed imaging and briefly evaluated by visual examination of the resulting beads. Using a defocused laser beam turned out to have two major advantages; 1. It adds heat to the melt pool in a manner that properly fuses the bottom and walls of the base material. 2. It counteracts difficulties due to an irregularly oscillating filler wire. These early results show that this can be a promising technique for joining thick steels with wide gaps.

Processing, Structural Characterization and Comparative Studies on Uniaxial Tensile Properties of a New Type of Porous Twisted Wire Material.

PubMed

Wu, Fei; Zhou, Zhaoyao; Duan, Liuyang; Xiao, Zhiyu

2015-08-27

A self-developed rotary multi-cutter device cuts stainless steel wire ropes into segments to fabricate twisted wires. Stainless steel porous twisted wire materials (PTWMs) with a spatial composite intertexture structure are produced by the compaction and subsequent vacuum solid-phase sintering of twisted wires. The stainless steel PTWMs show two types of typical uniaxial tensile failure modes, i.e. , a 45° angle fracture mode and an auxetic failure mode (the PTWMs expand along the direction perpendicular to the tension). The effects of the sintering parameters, porosities, wire diameters, and sampling direction on the tensile properties of the PTWMs are carefully investigated. By increasing the sintering temperature from 1130 °C to 1330 °C, the tensile strength of the PTWMs with 70% target porosity increased from 7.7 MPa to 28.6 MPa and the total failure goes down to 50%. When increasing the sintering time from 90 min to 150 min, the tensile strength increases from 12.4 MPa to 19.1 MPa and the total failure elongation drops to 78.6%. The tensile strength of the PTWMs increases from 28.9 MPa to 112.7 MPa with decreasing porosity from 69.5% to 46.0%, and the total failure elongation also increases from 14.8% to 40.7%. The tensile strength and the failure strain of the PTWMs with fine wires are higher than those of the PTWMs with coarse wires under the same porosity. Sampling direction has a small influence on the tensile properties of the PTWMs.

Orthodontic buccal tooth movement by nickel-free titanium-based shape memory and superelastic alloy wire.

PubMed

Suzuki, Akihiro; Kanetaka, Hiroyasu; Shimizu, Yoshinaka; Tomizuka, Ryo; Hosoda, Hideki; Miyazaki, Shuichi; Okuno, Osamu; Igarashi, Kaoru; Mitani, Hideo

2006-11-01

To examine the mechanical properties and the usefulness of titanium-niobium-aluminum (Ti-Nb-Al) wire in orthodontic tooth movement as compared with nickel-titanium (Ni-Ti) wire. The load deflection of expansion springs was gauged with an original jig. The gradient of the superelastic region was measured during the unloading process. Expansion springs comprising the two types of alloy wires were applied to upper first molars of rats. The distance between the first molars was measured with micrometer calipers. The force magnitude of the Ti-Nb-Al expansion spring was lower than that of the Ni-Ti expansion spring over the entire deflection range. The initial force magnitude and the gradient in the superelastic region of the Ti-Nb-Al expansion springs were half those of the Ni-Ti expansion springs. Thus, Ti-Nb-Al expansion springs generated lighter and more continuous force. Tooth movement in the Ni-Ti group proceeded in a stepwise fashion. On the other hand, tooth movement in the Ti-Nb-Al group showed relatively smooth and continuous progression. At 17 days after insertion of expansion springs, there were no significant differences between the Ti-Nb-Al and Ni-Ti groups in the amount of tooth movement. These results indicate that Ti-Nb-Al wire has excellent mechanical properties for smooth, continuous tooth movement and suggest that Ti-Nb-Al wire may be used as a practical nickel-free shape memory and superelastic alloy wire for orthodontic treatment as a substitute for Ni-Ti wire.

Advanced signal processing methods applied to guided waves for wire rope defect detection

NASA Astrophysics Data System (ADS)

Tse, Peter W.; Rostami, Javad

2016-02-01

Steel wire ropes, which are usually composed of a polymer core and enclosed by twisted wires, are used to hoist heavy loads. These loads are different structures that can be clamshells, draglines, elevators, etc. Since the loading of these structures is dynamic, the ropes are working under fluctuating forces in a corrosive environment. This consequently leads to progressive loss of the metallic cross-section due to abrasion and corrosion. These defects can be seen in the forms of roughened and pitted surface of the ropes, reduction in diameter, and broken wires. Therefore, their deterioration must be monitored so that any unexpected damage or corrosion can be detected before it causes fatal accident. This is of vital importance in the case of passenger transportation, particularly in elevators in which any failure may cause a catastrophic disaster. At present, the widely used methods for thorough inspection of wire ropes include visual inspection and magnetic flux leakage (MFL). Reliability of the first method is questionable since it only depends on the operators' eyes that fails to determine the integrity of internal wires. The later method has the drawback of being a point by point and time-consuming inspection method. Ultrasonic guided wave (UGW) based inspection, which has proved its capability in inspecting plate like structures such as tubes and pipes, can monitor the cross-section of wire ropes in their entire length from a single point. However, UGW have drawn less attention for defect detection in wire ropes. This paper reports the condition monitoring of a steel wire rope from a hoisting elevator with broken wires as a result of corrosive environment and fatigue. Experiments were conducted to investigate the efficiency of using magnetostrictive based UGW for rope defect detection. The obtained signals were analyzed by two time-frequency representation (TFR) methods, namely the Short Time Fourier Transform (STFT) and the Wavelet analysis. The location of the defect and its severity were successfully identified and characterized.

Generative Processes: Thick Drawing

ERIC Educational Resources Information Center

Wallick, Karl

2012-01-01

This article presents techniques and theories of generative drawing as a means for developing complex content in architecture design studios. Appending the word "generative" to drawing adds specificity to the most common representation tool and clarifies that such drawings are not singularly about communication or documentation but are…

Monolithic-Structured Single-Layered Textile-Based Dye-Sensitized Solar Cells.

PubMed

Yun, Min Ju; Cha, Seung I; Kim, Han Seong; Seo, Seon Hee; Lee, Dong Y

2016-10-06

Textile-structured solar cells are frequently discussed in the literature due to their prospective applications in wearable devices and in building integrated solar cells that utilize their flexibility, mechanical robustness, and aesthetic appearance, but the current approaches for textile-based solar cells-including the preparation of fibre-type solar cells woven into textiles-face several difficulties from high friction and tension during the weaving process. This study proposes a new structural concept and fabrication process for monolithic-structured textile-based dye-sensitized solar cells that are fabricated by a process similar to the cloth-making process, including the preparation of wires and yarns that are woven for use in textiles, printed, dyed, and packaged. The fabricated single-layered textile-based dye-sensitized solar cells successfully act as solar cells in our study, even under bending conditions. By controlling the inter-weft spacing and the number of Ti wires for the photoelectrode conductor, we have found that the performance of this type of dye-sensitized solar cell was notably affected by the spacing between photoelectrodes and counter-electrodes, the exposed areas of Ti wires to photoelectrodes, and photoelectrodes' surface morphology. We believe that this study provides a process and concept for improved textile-based solar cells that can form the basis for further research.

Fabricating Superior NiAl Bronze Components through Wire Arc Additive Manufacturing.

PubMed

Ding, Donghong; Pan, Zengxi; van Duin, Stephen; Li, Huijun; Shen, Chen

2016-08-03

Cast nickel aluminum bronze (NAB) alloy is widely used for large engineering components in marine applications due to its excellent mechanical properties and corrosion resistance. Casting porosity, as well as coarse microstructure, however, are accompanied by a decrease in mechanical properties of cast NAB components. Although heat treatment, friction stir processing, and fusion welding were implemented to eliminate porosity, improve mechanical properties, and refine the microstructure of as-cast metal, their applications are limited to either surface modification or component repair. Instead of traditional casting techniques, this study focuses on developing NAB components using recently expanded wire arc additive manufacturing (WAAM). Consumable welding wire is melted and deposited layer-by-layer on substrates producing near-net shaped NAB components. Additively-manufactured NAB components without post-processing are fully dense, and exhibit fine microstructure, as well as comparable mechanical properties, to as-cast NAB alloy. The effects of heat input from the welding process and post-weld-heat-treatment (PWHT) are shown to give uniform NAB alloys with superior mechanical properties revealing potential marine applications of the WAAM technique in NAB production.

Fabricating Superior NiAl Bronze Components through Wire Arc Additive Manufacturing

PubMed Central

Ding, Donghong; Pan, Zengxi; van Duin, Stephen; Li, Huijun; Shen, Chen

2016-01-01

Cast nickel aluminum bronze (NAB) alloy is widely used for large engineering components in marine applications due to its excellent mechanical properties and corrosion resistance. Casting porosity, as well as coarse microstructure, however, are accompanied by a decrease in mechanical properties of cast NAB components. Although heat treatment, friction stir processing, and fusion welding were implemented to eliminate porosity, improve mechanical properties, and refine the microstructure of as-cast metal, their applications are limited to either surface modification or component repair. Instead of traditional casting techniques, this study focuses on developing NAB components using recently expanded wire arc additive manufacturing (WAAM). Consumable welding wire is melted and deposited layer-by-layer on substrates producing near-net shaped NAB components. Additively-manufactured NAB components without post-processing are fully dense, and exhibit fine microstructure, as well as comparable mechanical properties, to as-cast NAB alloy. The effects of heat input from the welding process and post-weld-heat-treatment (PWHT) are shown to give uniform NAB alloys with superior mechanical properties revealing potential marine applications of the WAAM technique in NAB production. PMID:28773774

Drawing lithography for microneedles: a review of fundamentals and biomedical applications.

PubMed

Lee, Kwang; Jung, Hyungil

2012-10-01

A microneedle is a three-dimensional (3D) micromechanical structure and has been in the spotlight recently as a drug delivery system (DDS). Because a microneedle delivers the target drug after penetrating the skin barrier, the therapeutic effects of microneedles proceed from its 3D structural geometry. Various types of microneedles have been fabricated using subtractive micromanufacturing methods which are based on the inherently planar two-dimensional (2D) geometries. However, traditional subtractive processes are limited for flexible structural microneedles and makes functional biomedical applications for efficient drug delivery difficult. The authors of the present study propose drawing lithography as a unique additive process for the fabrication of a microneedle directly from 2D planar substrates, thus overcoming a subtractive process shortcoming. The present article provides the first overview of the principal drawing lithography technology: fundamentals and biomedical applications. The continuous drawing technique for an ultrahigh-aspect ratio (UHAR) hollow microneedle, stepwise controlled drawing technique for a dissolving microneedle, and drawing technique with antidromic isolation for a hybrid electro-microneedle (HEM) are reviewed, and efficient biomedical applications by drawing lithography-mediated microneedles as an innovative drug and gene delivery system are described. Drawing lithography herein can provide a great breakthrough in the development of materials science and biotechnology. Copyright © 2012 Elsevier Ltd. All rights reserved.

Precocious realists: perceptual and cognitive characteristics associated with drawing talent in non-autistic children

PubMed Central

Drake, Jennifer E.; Winner, Ellen

2009-01-01

A local processing bias in the block design task and in drawing strategy has been used to account for realistic drawing skill in individuals with autism. We investigated whether the same kind of local processing bias is seen in typically developing children with unusual skill in realistic graphic representation. Forty-three 5–11-year-olds who drew a still life completed a version of the block design task in both standard and segmented form, were tested for their memory for the block design items, and were given the Kaufmann Brief Intelligence Test-II. Children were classified as gifted, moderately gifted or typical on the basis of the level of realism in their drawings. Similar to autistic individuals, the gifted group showed a local processing bias in the block design task. But unlike autistic individuals, the gifted group showed a global advantage in the visual memory task and did not use a local drawing strategy; in addition, their graphic realism skill was related to verbal IQ. Differences in the extent of local processing bias in autistic and typically developing children with drawing talent are discussed. PMID:19528030

The Application of Ultrasonic Inspection to Crimped Electrical Connections

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

2010-01-01

The development of a new ultrasonic measurement technique to quantitatively assess wire crimp terminations is discussed. The development of a prototype instrument, based on a modified, commercially available, crimp tool, is demonstrated for applying this technique when wire crimps are installed. The crimp tool has three separate crimping locations that accommodate the three different ferrule diameters. The crimp tool in this study is capable of crimping wire diameters ranging from 12 to 26 American Wire Gauge (AWG). A transducer design is presented that allows for interrogation of each of the three crimp locations on the crimp tool without reconfiguring the device. An analysis methodology, based on transmitted ultrasonic energy and timing of the first received pulse is shown to correlate to both crimp location in the tool and the AWG of the crimp/ferrule combination. The detectability of a number of the crimp failure pathologies, such as missing strands, partially inserted wires and incomplete crimp compression, is discussed. A wave propagation model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process.

"Fly-by-Wireless": A Revolution in Aerospace Vehicle Architecture for Instrumentation and Control

NASA Technical Reports Server (NTRS)

Studor, George

2007-01-01

Aerospace vehicle programs have always counted on the cables and connectors to provide power, grounding, data and time synchronization throughout a vehicle's life-cycle. Even with numerous improvements, wiring and connector problems and sensors continue to be key failure points, causing many hours of troubleshooting and replacement. Costly flight delays have been precipitated by the need to troubleshoot cables/connections, and/or repair a sensor. Wiring continues to be too expensive to remove once it is installed, even with the weight penalties. Miles of test instrumentation and low flight sensor wires still plague the aerospace industry. New technology options for data connectivity, processing and micro/nano manufacturing are making it possible to retrofit existing vehicles, like the Space Shuttle. New vehicles can now develop architectures that provide for and take advantage of alternatives to wired connectivity. This project motivates the aerospace industry and technology providers to establish: (1) A new emphasis for system engineering approaches to reduce cables and connectors. (2) Provisions for modularity and accessibility in the vehicle architecture. (3) A set of technologies that support alternatives to wired connectivity.

Nuclear Quantum Effects in H+ and OH- Diffusion Along Confined Water Wires from Ab Initio Path Integral Molecular Dyanmics

NASA Astrophysics Data System (ADS)

Rossi, Mariana; Ceriotti, Michele; Manolopoulos, David

Diffusion of H+ and OH- along water wires provides an efficient mechanism for charge transport that is exploited by biological systems and shows promise in technological applications. However, what is lacking for a better control and design of these systems is a thorough theoretical understanding of the diffusion process at the atomic scale. Here we consider H+ and OH- in finite water wires using density functional theory. We employ machine learning techniques to identify the charged species, thus obtaining an agnostic definition of the charge. We employ thermostated ring polymer molecular dynamics and extract a ``universal'' diffusion coefficient from simulations with different wire sizes by considering Langevin dynamics on the potential of mean force of the charged species. In the classical case, diffusion coefficients depend significantly on the potential energy surface, in particular on how dispersion forces modulate O-O distances. NQEs, however, make the diffusion less sensitive to the underlying potential and geometry of the wire, presumably making them more robust to environment fluctuations.

Non-Destructive Detection of Wire Rope Discontinuities from Residual Magnetic Field Images Using the Hilbert-Huang Transform and Compressed Sensing

PubMed Central

Zhang, Juwei; Tan, Xiaojiang; Zheng, Pengbo

2017-01-01

Electromagnetic methods are commonly employed to detect wire rope discontinuities. However, determining the residual strength of wire rope based on the quantitative recognition of discontinuities remains problematic. We have designed a prototype device based on the residual magnetic field (RMF) of ferromagnetic materials, which overcomes the disadvantages associated with in-service inspections, such as large volume, inconvenient operation, low precision, and poor portability by providing a relatively small and lightweight device with improved detection precision. A novel filtering system consisting of the Hilbert-Huang transform and compressed sensing wavelet filtering is presented. Digital image processing was applied to achieve the localization and segmentation of defect RMF images. The statistical texture and invariant moment characteristics of the defect images were extracted as the input of a radial basis function neural network. Experimental results show that the RMF device can detect defects in various types of wire rope and prolong the service life of test equipment by reducing the friction between the detection device and the wire rope by accommodating a high lift-off distance. PMID:28300790

Expanding Music Listening Experience through Drawing

ERIC Educational Resources Information Center

Han, Yo-Jung

2016-01-01

Drawing while listening to music provides an opportunity for students to imagine and associate, leading to holistic listening experience. The personal qualitative listening experience triggered by music can be revealed in their drawings. In the process of representing of the listening experience through drawing, students can also increase their…

37 CFR 1.165 - Plant drawings.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Plant drawings. 1.165 Section... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES National Processing Provisions Plant Patents § 1.165 Plant drawings. (a) Plant patent drawings should be artistically and competently executed and must...