Hybrid micromachining using a nanosecond pulsed laser and micro EDM

NASA Astrophysics Data System (ADS)

Kim, Sanha; Kim, Bo Hyun; Chung, Do Kwan; Shin, Hong Shik; Chu, Chong Nam

2010-01-01

Micro electrical discharge machining (micro EDM) is a well-known precise machining process that achieves micro structures of excellent quality for any conductive material. However, the slow machining speed and high tool wear are main drawbacks of this process. Though the use of deionized water instead of kerosene as a dielectric fluid can reduce the tool wear and increase the machine speed, the material removal rate (MRR) is still low. In contrast, laser ablation using a nanosecond pulsed laser is a fast and non-wear machining process but achieves micro figures of rather low quality. Therefore, the integration of these two processes can overcome the respective disadvantages. This paper reports a hybrid process of a nanosecond pulsed laser and micro EDM for micromachining. A novel hybrid micromachining system that combines the two discrete machining processes is introduced. Then, the feasibility and characteristics of the hybrid machining process are investigated compared to conventional EDM and laser ablation. It is verified experimentally that the machining time can be effectively reduced in both EDM drilling and milling by rapid laser pre-machining prior to micro EDM. Finally, some examples of complicated 3D micro structures fabricated by the hybrid process are shown.

Influence of Crack-Tip Configurations on the Fracture Response of 0.04-Inch Thick 2024-T3 Aluminum Alloy Sheet

NASA Technical Reports Server (NTRS)

Johnston, William M.; Newman, James C. (Technical Monitor)

2002-01-01

A series of fracture tests were conducted on Middle-crack tension M(T) and compact tension C(T) specimens to determine the effects of specimen type, specimen width, notch tip sharpness and buckling on the fracture behavior of cracked thin sheet (0.04 inch thick) 2024-T3 aluminum alloy material. A series of M(T) specimens were tested with three notch tip configurations: (1) a fatigue pre-cracked notch, (2) a 0.010-inch-diameter wire electrical discharge machined (EDM) notch, and (3) a EDM notch sharpened with a razor blade. The test procedures are discussed and the experimental results for failure stress, load vs. crack extension and the material stress-strain response are reported.

A novel electromagnetic design and a new manufacturing process for the cavity BPM (Beam Position Monitor)

NASA Astrophysics Data System (ADS)

Dal Forno, Massimo; Craievich, Paolo; Baruzzo, Roberto; De Monte, Raffaele; Ferianis, Mario; Lamanna, Giuseppe; Vescovo, Roberto

2012-01-01

The Cavity Beam Position Monitor (BPM) is a beam diagnostic instrument which, in a seeded Free Electron Laser (FEL), allows the measurement of the electron beam position in a non-destructive way and with sub-micron resolution. It is composed by two resonant cavities called reference and position cavity, respectively. The measurement exploits the dipole mode that arises when the electron bunch passes off axis. In this paper we describe the Cavity BPM that has been designed and realized in the context of the FERMI@Elettra project [1]. New strategies have been adopted for the microwave design, for both the reference and the position cavities. Both cavities have been simulated by means of Ansoft HFSS [2] and CST Particle Studio [3], and have been realized using high precision lathe and wire-EDM (Electro-Discharge) machine, with a new technique that avoids the use of the sinker-EDM machine. Tuners have been used to accurately adjust the working frequencies for both cavities. The RF parameters have been estimated, and the modifications of the resonant frequencies produced by brazing and tuning have been evaluated. Finally, the Cavity BPM has been installed and tested in the presence of the electron beam.

The capacity for ethical decisions: the relationship between working memory and ethical decision making.

PubMed

Martin, April; Bagdasarov, Zhanna; Connelly, Shane

2015-04-01

Although various models of ethical decision making (EDM) have implicitly called upon constructs governed by working memory capacity (WMC), a study examining this relationship specifically has not been conducted. Using a sense making framework of EDM, we examined the relationship between WMC and various sensemaking processes contributing to EDM. Participants completed an online assessment comprised of a demographic survey, intelligence test, various EDM measures, and the Automated Operation Span task to determine WMC. Results indicated that WMC accounted for unique variance above and beyond ethics education, exposure to ethical issues, and intelligence in several sensemaking processes. Additionally, a marginally significant effect of WMC was also found with reference to EDM. Individual differences in WMC appear likely to play an important role in the ethical decision-making process, and future researchers may wish to consider their potential influences.

Effect of magnetic polarity on surface roughness during magnetic field assisted EDM of tool steel

NASA Astrophysics Data System (ADS)

Efendee, A. M.; Saifuldin, M.; Gebremariam, MA; Azhari, A.

2018-04-01

Electrical discharge machining (EDM) is one of the non-traditional machining techniques where the process offers wide range of parameters manipulation and machining applications. However, surface roughness, material removal rate, electrode wear and operation costs were among the topmost issue within this technique. Alteration of magnetic device around machining area offers exciting output to be investigated and the effects of magnetic polarity on EDM remain unacquainted. The aim of this research is to investigate the effect of magnetic polarity on surface roughness during magnetic field assisted electrical discharge machining (MFAEDM) on tool steel material (AISI 420 mod.) using graphite electrode. A Magnet with a force of 18 Tesla was applied to the EDM process at selected parameters. The sparks under magnetic field assisted EDM produced better surface finish than the normal conventional EDM process. At the presence of high magnetic field, the spark produced was squeezed and discharge craters generated on the machined surface was tiny and shallow. Correct magnetic polarity combination of MFAEDM process is highly useful to attain a high efficiency machining and improved quality of surface finish to meet the demand of modern industrial applications.

Development of an Eco-Friendly Electrical Discharge Machine (E-EDM) Using TRIZ Approach

NASA Astrophysics Data System (ADS)

Sreebalaji, V. S.; Saravanan, R.

Electrical Discharge Machine (EDM) is one of the non-traditional machining processes. EDM process is based on thermoelectric energy between the work and an electrode. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporization. The electrode and the work piece must have an electrical conductivity in order to generate the spark. Dielectric fluid acts as a spark conductor, concentrating the energy to a very narrow region. There are various types of products can be produced and finished using EDM such as Moulds, Dies, Parts of Aerodynamics, Automotives and Surgical components. This research work reveals how an Eco friendly EDM (E-EDM) can be modeled to replace die electric fluid and introducing ozonised oxygen in to EDM to eliminate harmful effects generated while machining by using dielectric, to make pollution free machining environment through a new design of EEDM using TRIZ (a Russian acronym for Theory of Inventive Problem Solving) approach, since Eco friendly design is the need of the hour.

AFM surface imaging of AISI D2 tool steel machined by the EDM process

NASA Astrophysics Data System (ADS)

Guu, Y. H.

2005-04-01

The surface morphology, surface roughness and micro-crack of AISI D2 tool steel machined by the electrical discharge machining (EDM) process were analyzed by means of the atomic force microscopy (AFM) technique. Experimental results indicate that the surface texture after EDM is determined by the discharge energy during processing. An excellent machined finish can be obtained by setting the machine parameters at a low pulse energy. The surface roughness and the depth of the micro-cracks were proportional to the power input. Furthermore, the AFM application yielded information about the depth of the micro-cracks is particularly important in the post treatment of AISI D2 tool steel machined by EDM.

Study on effect of tool electrodes on surface finish during electrical discharge machining of Nitinol

NASA Astrophysics Data System (ADS)

Sahu, Anshuman Kumar; Chatterjee, Suman; Nayak, Praveen Kumar; Sankar Mahapatra, Siba

2018-03-01

Electrical discharge machining (EDM) is a non-traditional machining process which is widely used in machining of difficult-to-machine materials. EDM process can produce complex and intrinsic shaped component made of difficult-to-machine materials, largely applied in aerospace, biomedical, die and mold making industries. To meet the required applications, the EDMed components need to possess high accuracy and excellent surface finish. In this work, EDM process is performed using Nitinol as work piece material and AlSiMg prepared by selective laser sintering (SLS) as tool electrode along with conventional copper and graphite electrodes. The SLS is a rapid prototyping (RP) method to produce complex metallic parts by additive manufacturing (AM) process. Experiments have been carried out varying different process parameters like open circuit voltage (V), discharge current (Ip), duty cycle (τ), pulse-on-time (Ton) and tool material. The surface roughness parameter like average roughness (Ra), maximum height of the profile (Rt) and average height of the profile (Rz) are measured using surface roughness measuring instrument (Talysurf). To reduce the number of experiments, design of experiment (DOE) approach like Taguchi’s L27 orthogonal array has been chosen. The surface properties of the EDM specimen are optimized by desirability function approach and the best parametric setting is reported for the EDM process. Type of tool happens to be the most significant parameter followed by interaction of tool type and duty cycle, duty cycle, discharge current and voltage. Better surface finish of EDMed specimen can be obtained with low value of voltage (V), discharge current (Ip), duty cycle (τ) and pulse on time (Ton) along with the use of AlSiMg RP electrode.

Structural Characteristics and Corrosion Behavior of Bio-Degradable Zn-Li Alloys in Stent Application

NASA Astrophysics Data System (ADS)

Zhao, Shan

Zinc has begun to be studied as a bio-degradable material in recent years due to its excellent corrosion rate and optimal biocompatibility. Unfortunately, pure Zn's intrinsic ultimate tensile strength (UTS; below 120 MPa) is lower than the benchmark (about 300 MPa) for cardiovascular stent materials, raising concerns about sufficient strength to support the blood vessel. Thus, modifying pure Zn to improve its mechanical properties is an important research topic. In this dissertation project, a new Zn-Li alloy has been developed to retain the outstanding corrosion behavior from Zn while improving the mechanical characteristics and uniform biodegradation once it is implanted into the artery of Sprague-Dawley rats. The completed work includes: Manufactured Zn-Li alloy ingots and sheets via induction vacuum casting, melt spinning, hot rolling deformation, and wire electro discharge machining (wire EDM) technique; processed alloy samples using cross sectioning, mounting, etching and polishing technique; • Characterized alloy ingots, sheets and wires using hardness and tensile test, XRD, BEI imaging, SEM, ESEM, FTIR, ICP-OES and electrochemical test; then selected the optimum composition for in vitro and in vivo experiments; • Mimicked the degradation behavior of the Zn-Li alloy in vitro using simulated body fluid (SBF) and explored the relations between corrosion rate, corrosion products and surface morphology with changing compositions; • Explanted the Zn-Li alloy wire in abdominal aorta of rat over 12 months and studied its degradation mechanism, rate of bioabsorption, cytotoxicity and corrosion product migration from histological analysis.

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

Hill, Mary Ann; Dombrowski, David E.; Clarke, Kester Diederik

U-10 wt. % Mo (U-10Mo) alloys are being developed as low enrichment monolithic fuel for the CONVERT program. Optimization of processing for the monolithic fuel is being pursued with the use of electrical discharge machining (EDM) under CONVERT HPRR WBS 1.2.4.5 Optimization of Coupon Preparation. The process is applicable to manufacturing experimental fuel plate specimens for the Mini-Plate-1 (MP-1) irradiation campaign. The benefits of EDM are reduced machining costs, ability to achieve higher tolerances, stress-free, burr-free surfaces eliminating the need for milling, and the ability to machine complex shapes. Kerf losses are much smaller with EDM (tenths of mm) comparedmore » to conventional machining (mm). Reliable repeatability is achievable with EDM due to its computer-generated machining programs.« less

Harmony search optimization in dimensional accuracy of die sinking EDM process using SS316L stainless steel

NASA Astrophysics Data System (ADS)

Deris, A. M.; Zain, A. M.; Sallehuddin, R.; Sharif, S.

2017-09-01

Electric discharge machine (EDM) is one of the widely used nonconventional machining processes for hard and difficult to machine materials. Due to the large number of machining parameters in EDM and its complicated structural, the selection of the optimal solution of machining parameters for obtaining minimum machining performance is remain as a challenging task to the researchers. This paper proposed experimental investigation and optimization of machining parameters for EDM process on stainless steel 316L work piece using Harmony Search (HS) algorithm. The mathematical model was developed based on regression approach with four input parameters which are pulse on time, peak current, servo voltage and servo speed to the output response which is dimensional accuracy (DA). The optimal result of HS approach was compared with regression analysis and it was found HS gave better result y giving the most minimum DA value compared with regression approach.

Design and Development of an Engineering Prototype Compact X-Ray Scanner (FMS 5000)

DTIC Science & Technology

1989-03-31

machined by "wire-EDM" (electro discharge machining ). Three different slice thicknesses can be selected from the scan menu. The set of slice thicknesses...circuit. This type of circuit is used whenever more than ten kilowatts of power are needed by a machine . For example, lathes and milling machines in a... machine shop usually use this type of input power. A three- phase circuit delivers power more efficiently than a single-phase circuit because three

Array servo scanning micro EDM of 3D micro cavities

NASA Astrophysics Data System (ADS)

Tong, Hao; Li, Yong; Yi, Futing

2011-05-01

Micro electro discharge machining (Micro EDM) is a non-traditional processing technology with the special advantages of low set-up cost and few cutting force in machining any conductive materials regardless of their hardness. As well known, die-sinking EDM is unsuitable for machining the complex 3D micro cavity less than 1mm due to the high-priced fabrication of 3D microelectrode itself and its serous wear during EDM process. In our former study, a servo scanning 3D micro-EDM (3D SSMEDM) method was put forward, and our experiments showed it was available to fabricate complex 3D micro-cavities. In this study, in order to improve machining efficiency and consistency accuracy for array 3D micro-cavities, an array-servo-scanning 3D micro EDM (3D ASSMEDM) method is presented considering the complementary advantages of the 3D SSMEDM and the array micro electrodes with simple cross-section. During 3D ASSMEDM process, the array cavities designed by CAD / CAM system can be batch-manufactured by servo scanning layer by layer using array-rod-like micro tool electrodes, and the axial wear of the array electrodes is compensated in real time by keeping discharge gap. To verify the effectiveness of the 3D ASSMEDM, the array-triangle-micro cavities (side length 630 μm) are batch-manufactured on P-doped silicon by applying the array-micro-electrodes with square-cross-section fabricated by LIGA process. Our exploratory experiment shows that the 3D ASSMEDM provides a feasible approach for the batch-manufacture of 3D array-micro-cavities of conductive materials.

Controlling corrosion rate of Magnesium alloy using powder mixed electrical discharge machining

NASA Astrophysics Data System (ADS)

Razak, M. A.; Rani, A. M. A.; Saad, N. M.; Littlefair, G.; Aliyu, A. A.

2018-04-01

Biomedical implant can be divided into permanent and temporary employment. The duration of a temporary implant applied to children and adult is different due to different bone healing rate among the children and adult. Magnesium and its alloys are compatible for the biodegradable implanting application. Nevertheless, it is difficult to control the degradation rate of magnesium alloy to suit the application on both the children and adult. Powder mixed electrical discharge machining (PM-EDM) method, a modified EDM process, has high capability to improve the EDM process efficiency and machined surface quality. The objective of this paper is to establish a formula to control the degradation rate of magnesium alloy using the PM-EDM method. The different corrosion rate of machined surface is hypothesized to be obtained by having different combinations of PM-EDM operation inputs. PM-EDM experiments are conducted using an opened-loop PM-EDM system and the in-vitro corrosion tests are carried out on the machined surface of each specimen. There are four operation inputs investigated in this study which are zinc powder concentration, peak current, pulse on-time and pulse off-time. The results indicate that zinc powder concentration is significantly affecting the response with 2 g/l of zinc powder concentration obtaining the lowest corrosion rate. The high localized temperature at the cutting zone in spark erosion process causes some of the zinc particles get deposited on the machined surface, hence improving the surface characteristics. The suspended zinc particles in the dielectric fluid have also improve the sparking efficiency and the uniformity of sparks distribution. From the statistical analysis, a formula was developed to control the corrosion rate of magnesium alloy within the range from 0.000183 mm/year to 0.001528 mm/year.

A machine vision system for micro-EDM based on linux

NASA Astrophysics Data System (ADS)

Guo, Rui; Zhao, Wansheng; Li, Gang; Li, Zhiyong; Zhang, Yong

2006-11-01

Due to the high precision and good surface quality that it can give, Electrical Discharge Machining (EDM) is potentially an important process for the fabrication of micro-tools and micro-components. However, a number of issues remain unsolved before micro-EDM becomes a reliable process with repeatable results. To deal with the difficulties in micro electrodes on-line fabrication and tool wear compensation, a micro-EDM machine vision system is developed with a Charge Coupled Device (CCD) camera, with an optical resolution of 1.61μm and an overall magnification of 113~729. Based on the Linux operating system, an image capturing program is developed with the V4L2 API, and an image processing program is exploited by using OpenCV. The contour of micro electrodes can be extracted by means of the Canny edge detector. Through the system calibration, the micro electrodes diameter can be measured on-line. Experiments have been carried out to prove its performance, and the reasons of measurement error are also analyzed.

Analysis of Investment IT Planning on Logistic Company Using COBIT 5

NASA Astrophysics Data System (ADS)

Fachri Pane, Syafrial; Maulana Awangga, Rolly; Nuraini, Rd.; Fathonah, Siti

2018-04-01

IT Investment planning to review goals business strategy development needs to support IT governance. Planning its investments will be assessed with a framework is issued by ISACA that COBIT 5 focus on domain EDM, APO, BAI, and MEA. Mapping from framework COBIT 5 with Val IT lead nine domain consisting of EDM01, EDM02, APO01, APO02, APO05, APO06, APO07, BAI01, and MEA01. Article search google using RACI diagram generating mapping organisation telecoms and authority structures for the review identify respondents from any domain. Under selected area be used to review counting process capability level, and for a discussion of development, priorities make recommendations shall perform in accordance process needs PT.XYZ logistics company. The translating process capability level determined by the company prior currently at on level 4. The capability level domain process in the EDM is level 4, while at domain APO, BAI, and MEA are on level 3 and gap on APO, BAI, and MEA. The company recommendation domain subscription APO, BAI, and MEA to increase the capabilities of the rate review process to achieve the targets that have can determine the company.

Effects of Process Parameters and Cryotreated Electrode on the Radial Overcut of Aisi 304 IN SiC Powder Mixed Edm

NASA Astrophysics Data System (ADS)

Bhaumik, Munmun; Maity, Kalipada

Powder mixed electro discharge machining (PMEDM) is further advancement of conventional electro discharge machining (EDM) where the powder particles are suspended in the dielectric medium to enhance the machining rate as well as surface finish. Cryogenic treatment is introduced in this process for improving the tool life and cutting tool properties. In the present investigation, the characterization of the cryotreated tempered electrode was performed. An attempt has been made to study the effect of cryotreated double tempered electrode on the radial overcut (ROC) when SiC powder is mixed in the kerosene dielectric during electro discharge machining of AISI 304. The process performance has been evaluated by means of ROC when peak current, pulse on time, gap voltage, duty cycle and powder concentration are considered as process parameters and machining is performed by using tungsten carbide electrodes (untreated and double tempered electrodes). A regression analysis was performed to correlate the data between the response and the process parameters. Microstructural analysis was carried out on the machined surfaces. Least radial overcut was observed for conventional EDM as compared to powder mixed EDM. Cryotreated double tempered electrode significantly reduced the radial overcut than untreated electrode.

Producing Production Level Tooling in Prototype Timing

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

Mc Hugh, Kevin Matthew; Knirsch, J.

A new rapid solidification process machine will be able to produce eight-inch diameter by six-inch thick finished cavities at the rate of one per hour - a rate that will change the tooling industry dramatically. Global Metal Technologies, Inc. (GMTI) (Solon, OH) has signed an exclusive license with Idaho National Engineered and Environmental Laboratories (INEEL) (Idaho Falls, ID) for the development and commercialization of the rapid solidification process (RSP tooling). The first production machine is scheduled for delivery in July 2001. The RSP tooling process is a method of producing production level tooling in prototype timing. The process' inventor, Kevinmore » McHugh, describes it as a rapid solidification method, which differentiates it from the standard spray forming methods. RSP itself is relatively straightforward. Molten metal is sprayed against the ceramic pattern, replicating the pattern's contours, surface texture and details. After spraying, the molten tool steel is cooled at room temperature and separated from the pattern. The irregular periphery of the freshly sprayed insert is squared off, either by machining or, in the case of harder tool steels, by wire EDM. XX« less

Ultrasonic Abrasive Removal Of EDM Recast

NASA Technical Reports Server (NTRS)

Mandel, Johnny L.; Jacobson, Marlowe S.

1990-01-01

Ultrasonic abrasive process removes layer of recast material generated during electrical-discharge machining (EDM) of damper pocket on turbine blade. Form-fitted tool vibrated ultrasonically in damper pocket from which material removed. Vibrations activate abrasive in pocket. Amount of material removed controlled precisely.

Research on the EDM Technology for Micro-holes at Complex Spatial Locations

NASA Astrophysics Data System (ADS)

Y Liu, J.; Guo, J. M.; Sun, D. J.; Cai, Y. H.; Ding, L. T.; Jiang, H.

2017-12-01

For the demands on machining micro-holes at complex spatial location, several key technical problems are conquered such as micro-Electron Discharge Machining (micro-EDM) power supply system’s development, the host structure’s design and machining process technical. Through developing low-voltage power supply circuit, high-voltage circuit, micro and precision machining circuit and clearance detection system, the narrow pulse and high frequency six-axis EDM machining power supply system is developed to meet the demands on micro-hole discharging machining. With the method of combining the CAD structure design, CAE simulation analysis, modal test, ODS (Operational Deflection Shapes) test and theoretical analysis, the host construction and key axes of the machine tool are optimized to meet the position demands of the micro-holes. Through developing the special deionized water filtration system to make sure that the machining process is stable enough. To verify the machining equipment and processing technical developed in this paper through developing the micro-hole’s processing flow and test on the real machine tool. As shown in the final test results: the efficient micro-EDM machining pulse power supply system, machine tool host system, deionized filtration system and processing method developed in this paper meet the demands on machining micro-holes at complex spatial locations.

Lif Spectroscopy of ThF and the Preparation of ThF^{+} for the Jila eEDM Experiment

NASA Astrophysics Data System (ADS)

Ng, Kia Boon; Zhou, Yan; Gresh, Dan; Cairncross, William; Roussy, Tanya; Shagam, Yuval; Cheng, Lan; Ye, Jun; Cornell, Eric

2017-06-01

ThF^{+} is a promising candidate for a second-generation molecular ion-based measurement of the permanent electric dipole moment of the electron (eEDM). Compared to the current HfF^{+} eEDM experiment, ThF^{+} has several advantages: (i) the eEDM-sensitive ^{3}Δ_1 electronic state is the ground state, which facilitates a long measurement coherence time; (ii) its effective electric field (38 GV/cm) is 50% larger than that of HfF+, which promises a direct increase of the eEDM sensitivity; and (iii) the ionization energy of neutral ThF is lower than its dissociation energy, which introduces a greater flexibility for rotational state-selective photoionization via core-nonpenetrating Rydberg states. We use laser-induced fluorescence (LIF) spectroscopy to find suitable intermediate states required for the state selective ionization process. We present the results of our LIF spectroscopy of ThF, and our current progress on efficient ThF ionization and on ThF^{+} dissociation.

Post-cast EDM method for reducing the thickness of a turbine nozzle wall

DOEpatents

Jones, Raymond Joseph; Bojappa, Parvangada Ganapathy; Kirkpatrick, Francis Lawrence; Schotsch, Margaret Jones; Rajan, Rajiv; Wei, Bin

2002-01-01

A post-cast EDM process is used to remove material from the interior surface of a nozzle vane cavity of a turbine. A thin electrode is passed through the cavity between opposite ends of the nozzle vane and displaced along the interior nozzle wall to remove the material along a predetermined path, thus reducing the thickness of the wall between the cavity and the external surface of the nozzle. In another form, an EDM process employing a profile as an electrode is disposed in the cavity and advanced against the wall to remove material from the wall until the final wall thickness is achieved, with the interior wall surface being complementary to the profile surface.

Electrode/workpiece combinations

NASA Astrophysics Data System (ADS)

Benedict, J. J.

1989-10-01

Of the many machine tool operations available in the shop today, plunge cut Electrical Discharge Machining (EDM) has become an increasingly useful method of materials fabrication. It is a necessary tool for the research and development type of work performed at the Lawrence Livermore National Laboratory (LLNL). With advancing technology, plunge cut EDMs are more efficient, faster, have greater accuracy and are able to produce better surface finishes. They have been in the past and will continue to be an important part of the production of quality parts in both the Precision and NC Shop. It should be kept in mind that as a non-traditional machining process, EDMing is a time consuming process that can be a very expensive method of producing parts. For this reason, it must be used in the most efficient manner in order to make it a cost-effective means of fabrication, although technology has advanced to the point of state-of-the-art equipment, there is currently a void in available technical information needed for use with this process. The type of information sought after concerns the area of electrode/workpiece combinations. This is in reference to the task of choosing the correct electrode material for the specific workpiece material encountered. A brief description of the EDM process will help in understanding the electrode/workpiece relationship.

Investigations of Effect of Rotary EDM Electrode on Machining Performance of Al6061 Alloy

NASA Astrophysics Data System (ADS)

Robinson Smart, D. S.; Jenish Smart, Joses; Periasamy, C.; Ratna Kumar, P. S. Samuel

2018-04-01

Electric Discharge Machining is an essential process which is being used for machining desired shape using electrical discharges which creates sparks. There will be electrodes subjected to electric voltage and which are separated by a dielectric liquid. Removing of material will be due to the continuous and rapid current discharges between two electrodes.. The spark is very carefully controlled and localized so that it only affects the surface of the material. Usually in order to prevent the defects which are arising due to the conventional machining, the Electric Discharge Machining (EDM) machining is preferred. Also intricate and complicated shapes can be machined effectively by use of Electric Discharge Machining (EDM). The EDM process usually does not affect the heat treat below the surface. This research work focus on the design and fabrication of rotary EDM tool for machining Al6061alloy and investigation of effect of rotary tool on surface finish, material removal rate and tool wear rate. Also the effect of machining parameters of EDM such as pulse on & off time, current on material Removal Rate (MRR), Surface Roughness (SR) and Electrode wear rate (EWR) have studied. Al6061 alloy can be used for marine and offshore applications by reinforcing some other elements. The investigations have revealed that MRR (material removal rate), surface roughness (Ra) have been improved with the reduction in the tool wear rate (TWR) when the tool is rotating instead of stationary. It was clear that as rotary speed of the tool is increasing the material removal rate is increasing with the reduction of surface finish and tool wear rate.

Study of the Productivity and Surface Quality of Hybrid EDM

NASA Astrophysics Data System (ADS)

Wankhade, Sandeepkumar Haribhau; Sharma, Sunil Bansilal

2016-01-01

The development of new, advanced engineering materials and the need for precise prototypes and low-volume production have made the electric discharge machining (EDM), an important manufacturing process to meet such demands. It is capable of machining geometrically complex and hard material components, that are precise and difficult-to-machine such as heat treated tool steels, composites, super alloys, ceramics, carbides etc. Conversely the low MRR limits its productivity. Abrasive water jet machine (AJM) tools are quick to setup and offer quick turn-around on the machine and could make parts out of virtually any material. They do not heat the material hence no heat affected zone and can make any intricate shape easily. The main advantages are flexibility, low heat production and ability to machine hard and brittle materials. Main disadvantages comprise the process produces a tapered cut and health hazards due to dry abrasives. To overcome the limitations and exploit the best of each of above processes; an attempt has been made to hybridize the processes of AJM and EDM. The appropriate abrasives routed with compressed air through the hollow electrode to construct the hybrid process i.e., abrasive jet electric discharge machining (AJEDM), the high speed abrasives could impinge on the machined surface to remove the recast layer caused by EDM process. The main process parameters were varied to explore their effects and experimental results show that AJEDM enhances the machining efficiency with better surface finish hence can fit the requirements of modern manufacturing applications.

Improvement of MRR and surface roughness during electrical discharge machining (EDM) using aluminum oxide powder mixed dielectric fluid

NASA Astrophysics Data System (ADS)

Khan, A. A.; Mohiuddin, A. K. M.; Latif, M. A. A.

2018-01-01

This paper discusses the effect of aluminium oxide (Al203) addition to dielectric fluid during electrical discharge machining (EDM). Aluminium oxide was added to the dielectric used in the EDM process to improve its performance when machining the stainless steel AISI 304, while copper was used as the electrode. Effect of the concentration of Al203 (0.3 mg/L) in dielectric fluid was compared with EDM without any addition of Al203. Surface quality of stainless steel and the material removal rate were investigated. Design of the experiment (DOE) was used for the experimental plan. Statistical analysis was done using ANOVA and then appropriate model was designated. The experimental results show that with dispersing of aluminium oxide in dielectric fluid surface roughness was improved while the material removal rate (MRR) was increased to some extent. These indicate the improvement of EDM performance using aluminium oxide in dielectric fluid. It was also found that with increase in pulse on time both MRR and surface roughness increase sharply.

Geant4 Developments for the Radon Electric Dipole Moment Search at TRIUMF

NASA Astrophysics Data System (ADS)

Rand, E. T.; Bangay, J. C.; Bianco, L.; Dunlop, R.; Finlay, P.; Garrett, P. E.; Leach, K. G.; Phillips, A. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Wong, J.

2011-09-01

An experiment is being developed at TRIUMF to search for a time-reversal violating electric dipole moment (EDM) in odd-A isotopes of Rn. Extensive simulations of the experiment are being performed with GEANT4 to study the backgrounds and sensitivity of the proposed measurement technique involving the detection of γ rays emitted following the β decay of polarized Rn nuclei. GEANT4 developments for the RnEDM experiment include both realistic modelling of the detector geometry and full tracking of the radioactive β, γ, internal conversion, and x-ray processes, including the γ-ray angular distributions essential for measuring an atomic EDM.

Precision machining of advanced materials with waterjets

NASA Astrophysics Data System (ADS)

Liu, H. T.

2017-01-01

Recent advances in abrasive waterjet technology have elevated to the state that it often competes on equal footing with lasers and EDM for precision machining. Under the support of a National Science Foundation SBIR Phase II grant, OMAX has developed and commercialized micro abrasive water technology that is incorporated into a MicroMAX® JetMa- chining® Center. Waterjet technology, combined both abrasive waterjet and micro abrasive waterjet technology, is capable of machining most materials from macro to micro scales for a wide range of part size and thickness. Waterjet technology has technological and manufacturing merits that cannot be matched by most existing tools. As a cold cutting tool that creates no heat-affected zone, for example, waterjet cuts much faster than wire EDM and laser when measures to minimize a heat-affected zone are taken into account. In addition, waterjet is material independent; it cuts materials that cannot be cut or are difficult to cut otherwise. The versatility of waterjet has also demonstrated machining simulated nanomaterials with large gradients of material properties from metal, nonmetal, to anything in between. This paper presents waterjet-machined samples made of a wide range of advanced materials from macro to micro scales.

Significant improvements of electrical discharge machining performance by step-by-step updated adaptive control laws

NASA Astrophysics Data System (ADS)

Zhou, Ming; Wu, Jianyang; Xu, Xiaoyi; Mu, Xin; Dou, Yunping

2018-02-01

In order to obtain improved electrical discharge machining (EDM) performance, we have dedicated more than a decade to correcting one essential EDM defect, the weak stability of the machining, by developing adaptive control systems. The instabilities of machining are mainly caused by complicated disturbances in discharging. To counteract the effects from the disturbances on machining, we theoretically developed three control laws from minimum variance (MV) control law to minimum variance and pole placements coupled (MVPPC) control law and then to a two-step-ahead prediction (TP) control law. Based on real-time estimation of EDM process model parameters and measured ratio of arcing pulses which is also called gap state, electrode discharging cycle was directly and adaptively tuned so that a stable machining could be achieved. To this end, we not only theoretically provide three proved control laws for a developed EDM adaptive control system, but also practically proved the TP control law to be the best in dealing with machining instability and machining efficiency though the MVPPC control law provided much better EDM performance than the MV control law. It was also shown that the TP control law also provided a burn free machining.

Contributions on Optimizing Approximations in the Study of Melting and Solidification Processes That Occur in Processing by Electro-Erosion

NASA Astrophysics Data System (ADS)

Potra, F. L.; Potra, T.; Soporan, V. F.

We propose two optimization methods of the processes which appear in EDM (Electrical Discharge Machining). First refers to the introduction of a new function approximating the thermal flux energy in EDM machine. Classical researches approximate this energy with the Gauss' function. In the case of unconventional technology the Gauss' bell became null only for r → +∞, where r is the radius of crater produced by EDM. We introduce a cubic spline regression which descends to zero at the crater's boundary. In the second optimization we propose modifications in technologies' work regarding the displacement of the tool electrode to the piece electrode such that the material melting to be realized in optimal time and the feeding speed with dielectric liquid regarding the solidification of the expulsed material. This we realize using the FAHP algorithm based on the theory of eigenvalues and eigenvectors, which lead to mean values of best approximation. [6

Influence of electrical resistivity and machining parameters on electrical discharge machining performance of engineering ceramics.

PubMed

Ji, Renjie; Liu, Yonghong; Diao, Ruiqiang; Xu, Chenchen; Li, Xiaopeng; Cai, Baoping; Zhang, Yanzhen

2014-01-01

Engineering ceramics have been widely used in modern industry for their excellent physical and mechanical properties, and they are difficult to machine owing to their high hardness and brittleness. Electrical discharge machining (EDM) is the appropriate process for machining engineering ceramics provided they are electrically conducting. However, the electrical resistivity of the popular engineering ceramics is higher, and there has been no research on the relationship between the EDM parameters and the electrical resistivity of the engineering ceramics. This paper investigates the effects of the electrical resistivity and EDM parameters such as tool polarity, pulse interval, and electrode material, on the ZnO/Al2O3 ceramic's EDM performance, in terms of the material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR). The results show that the electrical resistivity and the EDM parameters have the great influence on the EDM performance. The ZnO/Al2O3 ceramic with the electrical resistivity up to 3410 Ω·cm can be effectively machined by EDM with the copper electrode, the negative tool polarity, and the shorter pulse interval. Under most machining conditions, the MRR increases, and the SR decreases with the decrease of electrical resistivity. Moreover, the tool polarity, and pulse interval affect the EWR, respectively, and the electrical resistivity and electrode material have a combined effect on the EWR. Furthermore, the EDM performance of ZnO/Al2O3 ceramic with the electrical resistivity higher than 687 Ω·cm is obviously different from that with the electrical resistivity lower than 687 Ω·cm, when the electrode material changes. The microstructure character analysis of the machined ZnO/Al2O3 ceramic surface shows that the ZnO/Al2O3 ceramic is removed by melting, evaporation and thermal spalling, and the material from the working fluid and the graphite electrode can transfer to the workpiece surface during electrical discharge machining ZnO/Al2O3 ceramic.

Computing nucleon EDM on a lattice

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

Abramczyk, Michael; Izubuchi, Taku

I will discuss briefly recent changes in the methodology of computing the baryon EDM on a lattice. The associated correction substantially reduces presently existing lattice values for the proton and neutron theta-induced EDMs, so that even the most precise previous lattice results become consistent with zero. On one hand, this change removes previous disagreements between these lattice results and the phenomenological estimates of the nucleon EDM. On the other hand, the nucleon EDM becomes much harder to compute on a lattice. In addition, I will review the progress in computing quark chromo-EDM-induced nucleon EDM using chiral quark action.

Study on Gap Flow Field Simulation in Small Hole Machining of Ultrasonic Assisted EDM

NASA Astrophysics Data System (ADS)

Liu, Yu; Chang, Hao; Zhang, Wenchao; Ma, Fujian; Sha, Zhihua; Zhang, Shengfang

2017-12-01

When machining a small hole with high aspect ratio in EDM, it is hard for the flushing liquid entering the bottom gap and the debris could hardly be removed, which results in the accumulation of debris and affects the machining efficiency and machining accuracy. The assisted ultrasonic vibration can improve the removal of debris in the gap. Based on dynamics simulation software Fluent, a 3D model of debris movement in the gap flow field of EDM small hole machining assisted with side flushing and ultrasonic vibration is established in this paper. When depth to ratio is 3, the laws of different amplitudes and frequencies on debris distribution and removal are quantitatively analysed. The research results show that periodic ultrasonic vibration can promote the movement of debris, which is beneficial to the removal of debris in the machining gap. Compared to traditional small hole machining in EDM, the debris in the machining gap is greatly reduced, which ensures the stability of machining process and improves the machining efficiency.

Surface integrity and fatigue behaviour of electric discharged machined and milled austenitic stainless steel

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

Lundberg, Mattias, E-mail: mattias.lundberg@liu.se

Machining of austenitic stainless steels can result in different surface integrities and different machining process parameters will have a great impact on the component fatigue life. Understanding how machining processes affect the cyclic behaviour and microstructure are of outmost importance in order to improve existing and new life estimation models. Milling and electrical discharge machining (EDM) have been used to manufacture rectangular four-point bend fatigue test samples; subjected to high cycle fatigue. Before fatigue testing, surface integrity characterisation of the two surface conditions was conducted using scanning electron microscopy, surface roughness, residual stress profiles, and hardness profiles. Differences in cyclicmore » behaviour were observed between the two surface conditions by the fatigue testing. The milled samples exhibited a fatigue limit. EDM samples did not show the same behaviour due to ratcheting. Recrystallized nano sized grains were identified at the severely plastically deformed surface of the milled samples. Large amounts of bent mechanical twins were observed ~ 5 μm below the surface. Grain shearing and subsequent grain rotation from milling bent the mechanical twins. EDM samples showed much less plastic deformation at the surface. Surface tensile residual stresses of ~ 500 MPa and ~ 200 MPa for the milled and EDM samples respectively were measured. - Highlights: •Milled samples exhibit fatigue behaviour, but not EDM samples. •Four-point bending is not suitable for materials exhibiting pronounced ratcheting. •LAGB density can be used to quantitatively measure plastic deformation. •Grain shearing and rotation result in bent mechanical twins. •Nano sized grains evolve due to the heat of the operation.« less

Experimental Study of Tool Wear and Grinding Forces During BK-7 Glass Micro-grinding with Modified PCD Tool

NASA Astrophysics Data System (ADS)

Pratap, A.; Sahoo, P.; Patra, K.; Dyakonov, A. A.

2017-09-01

This study focuses on the improvement in grinding performance of BK-7 glass using polycrystalline diamond micro-tool. Micro-tools are modified using wire EDM and performance of modified tools is compared with that of as received tool. Tool wear of different types of tools are observed. To quantify the tool wear, a method based on weight loss of tool is introduced in this study. Modified tools significantly reduce tool wear in comparison to the normal tool. Grinding forces increase with machining time due to tool wear. However, modified tools produce lesser forces thus can improve life of the PCD micro-grinding tool.

Influence of Electrical Resistivity and Machining Parameters on Electrical Discharge Machining Performance of Engineering Ceramics

PubMed Central

Ji, Renjie; Liu, Yonghong; Diao, Ruiqiang; Xu, Chenchen; Li, Xiaopeng; Cai, Baoping; Zhang, Yanzhen

2014-01-01

Engineering ceramics have been widely used in modern industry for their excellent physical and mechanical properties, and they are difficult to machine owing to their high hardness and brittleness. Electrical discharge machining (EDM) is the appropriate process for machining engineering ceramics provided they are electrically conducting. However, the electrical resistivity of the popular engineering ceramics is higher, and there has been no research on the relationship between the EDM parameters and the electrical resistivity of the engineering ceramics. This paper investigates the effects of the electrical resistivity and EDM parameters such as tool polarity, pulse interval, and electrode material, on the ZnO/Al2O3 ceramic's EDM performance, in terms of the material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR). The results show that the electrical resistivity and the EDM parameters have the great influence on the EDM performance. The ZnO/Al2O3 ceramic with the electrical resistivity up to 3410 Ω·cm can be effectively machined by EDM with the copper electrode, the negative tool polarity, and the shorter pulse interval. Under most machining conditions, the MRR increases, and the SR decreases with the decrease of electrical resistivity. Moreover, the tool polarity, and pulse interval affect the EWR, respectively, and the electrical resistivity and electrode material have a combined effect on the EWR. Furthermore, the EDM performance of ZnO/Al2O3 ceramic with the electrical resistivity higher than 687 Ω·cm is obviously different from that with the electrical resistivity lower than 687 Ω·cm, when the electrode material changes. The microstructure character analysis of the machined ZnO/Al2O3 ceramic surface shows that the ZnO/Al2O3 ceramic is removed by melting, evaporation and thermal spalling, and the material from the working fluid and the graphite electrode can transfer to the workpiece surface during electrical discharge machining ZnO/Al2O3 ceramic. PMID:25364912

Application of grey-fuzzy approach in parametric optimization of EDM process in machining of MDN 300 steel

NASA Astrophysics Data System (ADS)

Protim Das, Partha; Gupta, P.; Das, S.; Pradhan, B. B.; Chakraborty, S.

2018-01-01

Maraging steel (MDN 300) find its application in many industries as it exhibits high hardness which are very difficult to machine material. Electro discharge machining (EDM) is an extensively popular machining process which can be used in machining of such materials. Optimization of response parameters are essential for effective machining of these materials. Past researchers have already used Taguchi for obtaining the optimal responses of EDM process for this material with responses such as material removal rate (MRR), tool wear rate (TWR), relative wear ratio (RWR), and surface roughness (SR) considering discharge current, pulse on time, pulse off time, arc gap, and duty cycle as process parameters. In this paper, grey relation analysis (GRA) with fuzzy logic is applied to this multi objective optimization problem to check the responses by an implementation of the derived parametric setting. It was found that the parametric setting derived by the proposed method results in better a response than those reported by the past researchers. Obtained results are also verified using the technique for order of preference by similarity to ideal solution (TOPSIS). The predicted result also shows that there is a significant improvement in comparison to the results of past researchers.

The influence of Span-20 surfactant and micro-/nano-Chromium (Cr) Powder Mixed Electrical Discharge Machining (PMEDM) on the surface characteristics of AISI D2 hardened steel

NASA Astrophysics Data System (ADS)

Hosni, N. A. J.; Lajis, M. A.

2018-04-01

The application of powder mixed dielectric to improve the efficiency of electrical discharge machining (EDM) has been extensively studied. Therefore, PMEDM have attracted the attention of many researchers since last few decades. Improvement in EDM process has resulted in the use of span-20 surfactant and Cr powder mixed in dielectric fluid, which results in increasing machiniability, better surface quality and faster machining time. However, the study of powder suspension size of surface charateristics in EDM field is still limited. This paper presents the improvement of micro-/nano- Cr powder size on the surface characteristics of the AISI D2 hardened steels in PMEDM. It has found that the reacst layer in PMEDM improved by as high as 41-53 % compared to conventional EDM. Also notably, the combination of added Cr powder and span-20 surfactant reduced the recast layer thickness significantly especially in nano-Cr size. This improvement was great potential adding nano-size Cr powder to dielectric for machining performance.

Performance and Surface Integrity of Ti6Al4V After Sinking EDM with Special Graphite Electrodes

NASA Astrophysics Data System (ADS)

Amorim, Fred L.; Stedile, Leandro J.; Torres, Ricardo D.; Soares, Paulo C.; Henning Laurindo, Carlos A.

2014-04-01

Titanium and its alloys have high chemical reactivity with most of the cutting tools. This makes it difficult to work with these alloys using conventional machining processes. Electrical discharge machining (EDM) emerges as an alternative technique to machining these materials. In this work, it is investigated the performance of three special grades of graphite as electrodes when ED-Machining Ti6Al4V samples under three different regimes. The main influences of electrical parameters are discussed for the samples material removal rate, volumetric relative wear and surface roughness. The samples surfaces were evaluated using SEM images, microhardness measurements, and x-ray diffraction. It was found that the best results for samples material removal rate, surface roughness, and volumetric relative wear were obtained for the graphite electrode with 10-μm particle size and negative polarity. For all samples machined by EDM and characterized by x-ray (XRD), it was identified the presence of titanium carbides. For the finish EDM regimes, the recast layer presents an increased amount of titanium carbides compared to semi-finish and rough regimes.

Experimental constraint on quark electric dipole moments

NASA Astrophysics Data System (ADS)

Liu, Tianbo; Zhao, Zhiwen; Gao, Haiyan

2018-04-01

The electric dipole moments (EDMs) of nucleons are sensitive probes of additional C P violation sources beyond the standard model to account for the baryon number asymmetry of the universe. As a fundamental quantity of the nucleon structure, tensor charge is also a bridge that relates nucleon EDMs to quark EDMs. With a combination of nucleon EDM measurements and tensor charge extractions, we investigate the experimental constraint on quark EDMs, and its sensitivity to C P violation sources from new physics beyond the electroweak scale. We obtain the current limits on quark EDMs as 1.27 ×10-24 e .cm for the up quark and 1.17 ×10-24 e .cm for the down quark at the scale of 4 GeV2 . We also study the impact of future nucleon EDM and tensor charge measurements, and show that upcoming new experiments will improve the constraint on quark EDMs by about 3 orders of magnitude leading to a much more sensitive probe of new physics models.

Neutron Electric Dipole Moment on the Lattice

NASA Astrophysics Data System (ADS)

Yoon, Boram; Bhattacharya, Tanmoy; Gupta, Rajan

2018-03-01

For the neutron to have an electric dipole moment (EDM), the theory of nature must have T, or equivalently CP, violation. Neutron EDM is a very good probe of novel CP violation in beyond the standard model physics. To leverage the connection between measured neutron EDM and novel mechanism of CP violation, one requires the calculation of matrix elements for CP violating operators, for which lattice QCD provides a first principle method. In this paper, we review the status of recent lattice QCD calculations of the contributions of the QCD Θ-term, the quark EDM term, and the quark chromo-EDM term to the neutron EDM.

Geant4 Simulations for the Radon Electric Dipole Moment Search at TRIUMF

NASA Astrophysics Data System (ADS)

Rand, Evan; Bangay, Jack; Bianco, Laura; Dunlop, Ryan; Finlay, Paul; Garrett, Paul; Leach, Kyle; Phillips, Andrew; Svensson, Carl; Sumithrarachchi, Chandana; Wong, James

2010-11-01

The existence of a permanent electric dipole moment (EDM) requires the violation of time-reversal symmetry (T) or, equivalently, the violation of charge conjugation C and parity P (CP). Although no particle EDM has yet been found, current theories beyond the Standard Model, e.g. multiple-Higgs theories, left-right symmetry, and supersymmetry, predict EDMs within current experimental reach. In fact, present limits on the EDMs of the neutron, electron and ^199Hg atom have significantly reduced the parameter spaces of these models. The measurement of a non-zero EDM would be a direct measurement of the violation of time-reversal symmetry, and would represent a clear signal of new physics beyond the Standard Model. Recent theoretical calculations predict large enhancements in the atomic EDMs for atoms with octupole-deformed nuclei, making odd-A Rn isotopes prime candidates for the EDM search. The Geant4 simulations presented here are essential for the development towards an EDM measurement. They provide an accurate description of γ-ray scattering and backgrounds in the experimental apparatus, and are being used to study the overall sensitivity of the RnEDM experiment at TRIUMF in Vancouver, B.C.

Theoretical prediction and impact of fundamental electric dipole moments

DOE PAGES

Ellis, Sebastian A. R.; Kane, Gordon L.

2016-01-13

The predicted Standard Model (SM) electric dipole moments (EDMs) of electrons and quarks are tiny, providing an important window to observe new physics. Theories beyond the SM typically allow relatively large EDMs. The EDMs depend on the relative phases of terms in the effective Lagrangian of the extended theory, which are generally unknown. Underlying theories, such as string/M-theories compactified to four dimensions, could predict the phases and thus EDMs in the resulting supersymmetric (SUSY) theory. Earlier one of us, with collaborators, made such a prediction and found, unexpectedly, that the phases were predicted to be zero at tree level inmore » the theory at the unification or string scale ~O(10 16 GeV). Electroweak (EW) scale EDMs still arise via running from the high scale, and depend only on the SM Yukawa couplings that also give the CKM phase. Here we extend the earlier work by studying the dependence of the low scale EDMs on the constrained but not fully known fundamental Yukawa couplings. The dominant contribution is from two loop diagrams and is not sensitive to the choice of Yukawa texture. The electron EDM should not be found to be larger than about 5 × 10 –30e cm, and the neutron EDM should not be larger than about 5 × 10 –29e cm. These values are quite a bit smaller than the reported predictions from Split SUSY and typical effective theories, but much larger than the Standard Model prediction. Also, since models with random phases typically give much larger EDMs, it is a significant testable prediction of compactified M-theory that the EDMs should not be above these upper limits. The actual EDMs can be below the limits, so once they are measured they could provide new insight into the fundamental Yukawa couplings of leptons and quarks. As a result, we comment also on the role of strong CP violation. EDMs probe fundamental physics near the Planck scale.« less

Theoretical prediction and impact of fundamental electric dipole moments

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

Ellis, Sebastian A. R.; Kane, Gordon L.

The predicted Standard Model (SM) electric dipole moments (EDMs) of electrons and quarks are tiny, providing an important window to observe new physics. Theories beyond the SM typically allow relatively large EDMs. The EDMs depend on the relative phases of terms in the effective Lagrangian of the extended theory, which are generally unknown. Underlying theories, such as string/M-theories compactified to four dimensions, could predict the phases and thus EDMs in the resulting supersymmetric (SUSY) theory. Earlier one of us, with collaborators, made such a prediction and found, unexpectedly, that the phases were predicted to be zero at tree level inmore » the theory at the unification or string scale ~O(10 16 GeV). Electroweak (EW) scale EDMs still arise via running from the high scale, and depend only on the SM Yukawa couplings that also give the CKM phase. Here we extend the earlier work by studying the dependence of the low scale EDMs on the constrained but not fully known fundamental Yukawa couplings. The dominant contribution is from two loop diagrams and is not sensitive to the choice of Yukawa texture. The electron EDM should not be found to be larger than about 5 × 10 –30e cm, and the neutron EDM should not be larger than about 5 × 10 –29e cm. These values are quite a bit smaller than the reported predictions from Split SUSY and typical effective theories, but much larger than the Standard Model prediction. Also, since models with random phases typically give much larger EDMs, it is a significant testable prediction of compactified M-theory that the EDMs should not be above these upper limits. The actual EDMs can be below the limits, so once they are measured they could provide new insight into the fundamental Yukawa couplings of leptons and quarks. As a result, we comment also on the role of strong CP violation. EDMs probe fundamental physics near the Planck scale.« less

Surface structuring of boron doped CVD diamond by micro electrical discharge machining

NASA Astrophysics Data System (ADS)

Schubert, A.; Berger, T.; Martin, A.; Hackert-Oschätzchen, M.; Treffkorn, N.; Kühn, R.

2018-05-01

Boron doped diamond materials, which are generated by Chemical Vapor Deposition (CVD), offer a great potential for the application on highly stressed tools, e. g. in cutting or forming processes. As a result of the CVD process rough surfaces arise, which require a finishing treatment in particular for the application in forming tools. Cutting techniques such as milling and grinding are hardly applicable for the finish machining because of the high strength of diamond. Due to its process principle of ablating material by melting and evaporating, Electrical Discharge Machining (EDM) is independent of hardness, brittleness or toughness of the workpiece material. EDM is a suitable technology for machining and structuring CVD diamond, since boron doped CVD diamond is electrically conductive. In this study the ablation characteristics of boron doped CVD diamond by micro electrical discharge machining are investigated. Experiments were carried out to investigate the influence of different process parameters on the machining result. The impact of tool-polarity, voltage and discharge energy on the resulting erosion geometry and the tool wear was analyzed. A variation in path overlapping during the erosion of planar areas leads to different microstructures. The results show that micro EDM is a suitable technology for finishing of boron doped CVD diamond.

Microstructure, Morphology, and Nanomechanical Properties Near Fine Holes Produced by Electro-Discharge Machining

NASA Astrophysics Data System (ADS)

Blau, P. J.; Howe, J. Y.; Coffey, D. W.; Trejo, R. M.; Kenik, E. D.; Jolly, B. C.; Yang, N.

2012-08-01

Fine holes in metal alloys are employed for many important technological purposes, including cooling and the precise atomization of liquids. For example, they play an important role in the metering and delivery of fuel to the combustion chambers in energy-efficient, low-emission diesel engines. Electro-discharge machining (EDM) is one process employed to produce such holes. Since the hole shape and bore morphology can affect fluid flow, and holes also represent structural discontinuities in the tips of the spray nozzles, it is important to understand the microstructures adjacent to these holes, the features of the hole walls, and the nanomechanical properties of the material that was in some manner altered by the EDM hole-making process. Several techniques were used to characterize the structure and properties of spray-holes in a commercial injector nozzle. These include scanning electron microscopy, cross sectioning and metallographic etching, bore surface roughness measurements by optical interferometry, scanning electron microscopy, and transmission electron microscopy of recast EDM layers extracted with the help of a focused ion beam.

Effect of the Machining Processes on Low Cycle Fatigue Behavior of a Powder Metallurgy Disk

NASA Technical Reports Server (NTRS)

Telesman, J.; Kantzos, P.; Gabb, T. P.; Ghosn, L. J.

2010-01-01

A study has been performed to investigate the effect of various machining processes on fatigue life of configured low cycle fatigue specimens machined out of a NASA developed LSHR P/M nickel based disk alloy. Two types of configured specimen geometries were employed in the study. To evaluate a broach machining processes a double notch geometry was used with both notches machined using broach tooling. EDM machined notched specimens of the same configuration were tested for comparison purposes. Honing finishing process was evaluated by using a center hole specimen geometry. Comparison testing was again done using EDM machined specimens of the same geometry. The effect of these machining processes on the resulting surface roughness, residual stress distribution and microstructural damage were characterized and used in attempt to explain the low cycle fatigue results.

Scale effects and a method for similarity evaluation in micro electrical discharge machining

NASA Astrophysics Data System (ADS)

Liu, Qingyu; Zhang, Qinhe; Wang, Kan; Zhu, Guang; Fu, Xiuzhuo; Zhang, Jianhua

2016-08-01

Electrical discharge machining(EDM) is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at the micro-scale, which can make it difficult to predict and optimize the machining performances of micro EDM. A new concept of "scale effects" in micro EDM is proposed, the scale effects can reveal the difference in machining performances between micro EDM and conventional macro EDM. Similarity theory is presented to evaluate the scale effects in micro EDM. Single factor experiments are conducted and the experimental results are analyzed by discussing the similarity difference and similarity precision. The results show that the output results of scale effects in micro EDM do not change linearly with discharge parameters. The values of similarity precision of machining time significantly increase when scaling-down the capacitance or open-circuit voltage. It is indicated that the lower the scale of the discharge parameter, the greater the deviation of non-geometrical similarity degree over geometrical similarity degree, which means that the micro EDM system with lower discharge energy experiences more scale effects. The largest similarity difference is 5.34 while the largest similarity precision can be as high as 114.03. It is suggested that the similarity precision is more effective in reflecting the scale effects and their fluctuation than similarity difference. Consequently, similarity theory is suitable for evaluating the scale effects in micro EDM. This proposed research offers engineering values for optimizing the machining parameters and improving the machining performances of micro EDM.

Effect of electrical discharging on formation of nanoporous biocompatible layer on Ti-6Al-4V alloys.

PubMed

Yang, Tzu-Sen; Huang, Mao-Suan; Wang, Mao-Sheng; Lin, Ming-Hong; Tsai, Meng-Yuan; Wang, Pei-Yi Wang

2013-08-01

In this study, the electrical discharge machining (EDM) was formed on the surface of the Ti-6Al-4V (Ti64) specimen. The properties of adhesion and proliferation of MG-63 cells were evaluated the interactions between the EDM-treated layer and cells. The incorporation of oxygen roughened the EDM-treated specimen surface on a microscale, where the nanoscale pores were superimposed. The EDM-treated layer, which can generate the thick anatase TiO2 on the Ti64 surface, afforded a cytocompatible environment. In cell culture, alkaline phosphatase activity and osteocalcin can be dramatically enhanced on the EDM-treated surfaces when compared with the untreated surface. In addition, the increase in peak currents to the EDM functionalization led to enhancement of multiple osteoblast functions. This study reveals that the chemistry and crystallinity of the EDM-treated layer played important roles in affecting osteoblastic responses to the specimens, which provided insight into the development of new biomedical implant surfaces.

Machining of Molybdenum by EDM-EP and EDC Processes

NASA Astrophysics Data System (ADS)

Wu, K. L.; Chen, H. J.; Lee, H. M.; Lo, J. S.

2017-12-01

Molybdenum metal (Mo) can be machined with conventional tools and equipment, however, its refractory propertytends to chip when being machined. In this study, the nonconventional processes of electrical discharge machining (EDM) and electro-polishing (EP) have been conducted to investigate the machining of Mo metal and fabrication of Mo grid. Satisfactory surface quality was obtained using appropriate EDM parameters of Ip ≦ 3A and Ton < 80μs at a constant pulse interval of 100μs. The finished Mometal has accomplished by selecting appropriate EP parameters such as electrolyte flow rate of 0.42m/s under EP voltage of 50V and flush time of 20 sec to remove the recast layer and craters on the surface of Mo metal. The surface roughness of machined Mo metal can be improved from Ra of 0.93μm (Rmax = 8.51μm) to 0.23μm (Rmax = 1.48μm). Machined Mo metal surface, when used as grid component in electron gun, needs to be modified by coating materials with high work function, such as silicon carbide (SiC). The main purpose of this study is to explore the electrical discharge coating (EDC) process for coating the SiC layer on EDMed Mo metal. Experimental results proved that the appropriate parameters of Ip = 5A and Ton = 50μs at Toff = 10μs can obtain the deposit with about 60μm thickness. The major phase of deposit on machined Mo surface was SiC ceramic, while the minor phases included MoSi2 and/or SiO2 with the presence of free Si due to improper discharging parameters and the use of silicone oil as the dielectric fluid.

Fabricating TiO2 nanocolloids by electric spark discharge method at normal temperature and pressure.

PubMed

Tseng, Kuo-Hsiung; Chang, Chaur-Yang; Chung, Meng-Yun; Cheng, Ting-Shou

2017-11-17

In this study, TiO 2 nanocolloids were successfully fabricated in deionized water without using suspending agents through using the electric spark discharge method at room temperature and under normal atmospheric pressure. This method was exceptional because it did not create nanoparticle dispersion and the produced colloids contained no derivatives. The proposed method requires only traditional electrical discharge machines (EDMs), self-made magnetic stirrers, and Ti wires (purity, 99.99%). The EDM pulse on time (T on ) and pulse off time (T off ) were respectively set at 50 and 100 μs, 100 and 100 μs, 150 and 100 μs, and 200 and 100 μs to produce four types of TiO 2 nanocolloids. Zetasizer analysis of the nanocolloids showed that a decrease in T on increased the suspension stability, but there were no significant correlations between T on and particle size. Colloids produced from the four production configurations showed a minimum particle size between 29.39 and 52.85 nm and a zeta-potential between -51.2 and -46.8 mV, confirming that the method introduced in this study can be used to produce TiO 2 nanocolloids with excellent suspension stability. Scanning electron microscopy with energy dispersive spectroscopy also indicated that the TiO 2 colloids did not contain elements other than Ti and oxygen.

Drilling of Hybrid Titanium Composite Laminate (HTCL) with Electrical Discharge Machining.

PubMed

Ramulu, M; Spaulding, Mathew

2016-09-01

An experimental investigation was conducted to determine the application of die sinker electrical discharge machining (EDM) as it applies to a hybrid titanium thermoplastic composite laminate material. Holes were drilled using a die sinker EDM. The effects of peak current, pulse time, and percent on-time on machinability of hybrid titanium composite material were evaluated in terms of material removal rate (MRR), tool wear rate, and cut quality. Experimental models relating each process response to the input parameters were developed and optimum operating conditions with a short cutting time, achieving the highest workpiece MRR, with very little tool wear were determined to occur at a peak current value of 8.60 A, a percent on-time of 36.12%, and a pulse time of 258 microseconds. After observing data acquired from experimentation, it was determined that while use of EDM is possible, for desirable quality it is not fast enough for industrial application.

Drilling of Hybrid Titanium Composite Laminate (HTCL) with Electrical Discharge Machining

PubMed Central

Ramulu, M.; Spaulding, Mathew

2016-01-01

An experimental investigation was conducted to determine the application of die sinker electrical discharge machining (EDM) as it applies to a hybrid titanium thermoplastic composite laminate material. Holes were drilled using a die sinker EDM. The effects of peak current, pulse time, and percent on-time on machinability of hybrid titanium composite material were evaluated in terms of material removal rate (MRR), tool wear rate, and cut quality. Experimental models relating each process response to the input parameters were developed and optimum operating conditions with a short cutting time, achieving the highest workpiece MRR, with very little tool wear were determined to occur at a peak current value of 8.60 A, a percent on-time of 36.12%, and a pulse time of 258 microseconds. After observing data acquired from experimentation, it was determined that while use of EDM is possible, for desirable quality it is not fast enough for industrial application. PMID:28773866

Electric dipole moment of the deuteron in the standard model with NN - ΛN - ΣN coupling

NASA Astrophysics Data System (ADS)

Yamanaka, Nodoka

2017-07-01

We calculate the electric dipole moment (EDM) of the deuteron in the standard model with | ΔS | = 1 interactions by taking into account the NN - ΛN - ΣN channel coupling, which is an important nuclear level systematics. The two-body problem is solved with the Gaussian Expansion Method using the realistic Argonne v18 nuclear force and the YN potential which can reproduce the binding energies of Λ3H, Λ3He, and Λ4He. The | ΔS | = 1 interbaryon potential is modeled by the one-meson exchange process. It is found that the deuteron EDM is modified by less than 10%, and the main contribution to this deviation is due to the polarization of the hyperon-nucleon channels. The effect of the YN interaction is small, and treating ΛN and ΣN channels as free is a good approximation for the EDM of the deuteron.

The Usage of the U.S. Environmental Protection Agency’s (USEPA) Motor Vehicle Emission Simulator (MOVES) with the Federal Aviation Administration’s (FAA) Emissions and Dispersion Modeling System (EDMS)

DOT National Transportation Integrated Search

2014-03-01

As of March 2013, USEPA requires the usage of MOVES as a replacement for MOBILE. This means that EDMS analysts must use MOVES with EDMS instead of MOBILE. The plan is not to modify EDMS which continues to be integrated with MOBILE6; but instead, FAA ...

Electronic document management systems: an overview.

PubMed

Kohn, Deborah

2002-08-01

For over a decade, most health care information technology (IT) professionals erroneously learned that document imaging, which is one of the many component technologies of an electronic document management system (EDMS), is the only technology of an EDMS. In addition, many health care IT professionals erroneously believed that EDMSs have either a limited role or no place in IT environments. As a result, most health care IT professionals do not understand documents and unstructured data and their value as structured data partners in most aspects of transaction and information processing systems.

Integration of AERMOD into EDMS

DOT National Transportation Integrated Search

2003-06-22

The Federal Aviation Administration (FAA) requires the use of the Emissions and : Dispersion Modeling System (EDMS) for air quality analysis involving aviation sources. : Dispersion in EDMS has previously been computed by CALINE3 and PAL2. With the :...

New two-loop contributions to hadronic EDMs in the MSSM

NASA Astrophysics Data System (ADS)

Hisano, Junji; Nagai, Minoru; Paradisi, Paride

2006-11-01

Flavor-changing terms with CP-violating phases in the quark sector may contribute to the hadronic electric dipole moments (EDMs). However, within the Standard Model (SM), the source of CP violation comes from the unique CKM phase, and it turns out that the EDMs are strongly suppressed. This implies that the EDMs are very sensitive to non-minimal flavor violation structures of theories beyond the SM. In this Letter, we discuss the quark EDMs and CEDMs (chromoelectric dipole moments) in the MSSM with general flavor-changing terms in the squark mass matrices. In particular, the charged-Higgs mediated contributions to the down-quark EDM and CEDM are evaluated at two-loop level. We point out that these two-loop contributions may dominate over the one-loop induced gluino or higgsino contributions even when the squark and gluino masses are around few TeV and tanβ is moderate.

Structural analysis of HyFlex EDM instruments.

PubMed

Iacono, F; Pirani, C; Generali, L; Bolelli, G; Sassatelli, P; Lusvarghi, L; Gandolfi, M G; Giorgini, L; Prati, C

2017-03-01

To compare the phase transformation behaviour, the microstructure, the nano-hardness and the surface chemistry of electro-discharge machined HyFlex EDM instruments with conventionally manufactured HyFlex CM. New and laboratory used HyFlex EDM were examined by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Nano-hardness and modulus of elasticity were also investigated using a maximum load of 20 mN with a minimum of 40 significant indentations for each sample. Raman spectroscopy and field emission-scanning electron microscope (FE-SEM) were used to assess the surface chemistry of HyFlex EDM. HyFlex CM were subjected to the same investigations and used as a comparison. Nano-indentation data were statistically analysed using the Student's t-test. XRD analysis on HyFlex EDM revealed the presence of martensite and rhombohedral R-phase, while a mixture of martensite and austenite structure was identified in HyFlex CM. DSC analysis also disclosed higher austenite finish (Af) temperatures for electro-discharge machining (EDM) instruments. Significant differences in nano-hardness and modulus of elasticity were found between EDM and CM files (P < 0.05). FE-SEM and EDS analyses confirmed that both new EDM and CM files were covered by an oxide layer. Micro-Raman spectroscopy assessed the presence of rutile-TiO 2 . HyFlex EDM revealed peculiar structural properties, such as increased phase transformation temperatures and hardness. Present results corroborated previous findings and shed light on the enhanced mechanical behaviour of these instruments. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Laser melting of groove defect repair on high thermal conductivity steel (HTCS-150)

NASA Astrophysics Data System (ADS)

Norhafzan, B.; Aqida, S. N.; Fazliana, F.; Reza, M. S.; Ismail, I.; Khairil, C. M.

2018-02-01

This paper presents laser melting repair of groove defect on HTCS-150 surface using Nd:YAG laser system. Laser melting process was conducted using JK300HPS Nd:YAG twin lamp laser source with 1064 nm wavelength and pulsed mode. The parameters are pulse repetition frequency (PRF) that is set from 70 to 100 Hz, average power ( P A) of 50-70 W, and laser spot size of 0.7 mm. HTCS-150 samples were prepared with groove dimension of 0.3 mm width and depths of 0.5 mm using EDM wire cut. Groove defect repaired using laser melting process on groove surface area with various parameters' process. The melted surface within the groove was characterized for subsurface hardness profile, roughness, phase identification, chemical composition, and metallographic study. The roughness analysis indicates high PRF at large spot size caused high surface roughness and low surface hardness. Grain refinement of repaired layer was analyzed within the groove as a result of rapid heating and cooling. The hardness properties of modified HTCS inside the groove and the bulk surface increased two times from as received HTCS due to grain refinement which is in agreement with Hall-Petch equation. These findings are significant to parameter design of die repair for optimum surface integrity and potential for repairing crack depth and width of less than 0.5 and 0.3 mm, respectively.

e_Disease Management. A system for the management of the chronic conditions.

PubMed

Guillén, Sergio; Meneu, Maria Teresa; Serafin, Riccardo; Arredondo, Maria Teresa; Castellano, Elena; Valdivieso, Bernardo

2010-01-01

Disease Management (DM) is a system of coordinated healthcare intervention and communications for populations with conditions in which patient self-care efforts are significant. e-DM makes reference to processes of DM based on clinical guidelines sustained in the scientific medical evidence and supported by the intervention of Information and Telecommunication Technology (ICT) in all levels where these plans are developed. This paper discusses the design and implementation of a e-DM system which meets the requirements for the integrated chronic disease management following the recommendations of the Disease Management Association and the American Heart Association.

Direct and indirect constraints on CP-violating Higgs-quark and Higgs-gluon interactions

DOE PAGES

Chien, Y. T.; Cirigliano, V.; Dekens, W.; ...

2016-02-01

Here we investigate direct and indirect constraints on the complete set of anomalous CP-violating Higgs couplings to quarks and gluons originating from dimension-6 operators, by studying their signatures at the LHC and in electric dipole moments (EDMs). We also show that existing uncertainties in hadronic and nuclear matrix elements have a significant impact on the interpretation of EDM experiments, and we quantify the improvements needed to fully exploit the power of EDM searches. Currently, the best bounds on the anomalous CP-violating Higgs interactions come from a combination of EDM measurements and the data from LHC Run 1. We argue thatmore » Higgs production cross section and branching ratios measurements at the LHC Run 2 will not improve the constraints significantly. But, the bounds on the couplings scale roughly linearly with EDM limits, so that future theoretical and experimental EDM developments can have a major impact in pinning down interactions of the Higgs.« less

Direct and indirect constraints on CP-violating Higgs-quark and Higgs-gluon interactions

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

Chien, Y. T.; Cirigliano, V.; Dekens, W.

Here we investigate direct and indirect constraints on the complete set of anomalous CP-violating Higgs couplings to quarks and gluons originating from dimension-6 operators, by studying their signatures at the LHC and in electric dipole moments (EDMs). We also show that existing uncertainties in hadronic and nuclear matrix elements have a significant impact on the interpretation of EDM experiments, and we quantify the improvements needed to fully exploit the power of EDM searches. Currently, the best bounds on the anomalous CP-violating Higgs interactions come from a combination of EDM measurements and the data from LHC Run 1. We argue thatmore » Higgs production cross section and branching ratios measurements at the LHC Run 2 will not improve the constraints significantly. But, the bounds on the couplings scale roughly linearly with EDM limits, so that future theoretical and experimental EDM developments can have a major impact in pinning down interactions of the Higgs.« less

The search for permanent electric dipole moments, in particular for the one of the neutron

ScienceCinema

Kirch, Klaus

2018-05-04

Nonzero permanent electric dipole moments (EDM) of fundamental systems like particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new CP violating phases which often lead to the prediciton of larger EDM. EDM searches in different systems are complementary and various efforts worldwide are underway, but no finite value could be established yet. An improved search for the EDM of the neutron requires, among other things, much better statistics. At PSI, we are presently commissioning a new high intensity source of ultracold neutrons. At the same time, with an international collaboration, we are setting up for a new measurement of the neutron EDM which is starting this year.

Synthesis of Aluminium Nanoparticles in A Water/Polyethylene Glycol Mixed Solvent using μ-EDM

NASA Astrophysics Data System (ADS)

Sahu, R. K.; Hiremath, Somashekhar S.

2017-08-01

Nanoparticles present a practical way of retaining the results of the property at the atomic or molecular level. Due to the recent use of nanoparticles in scientific, industrial and medical applications, synthesis of nanoparticles and their characterization have become considerably important. Currently, aluminium nanoparticles have attracted significant research attention because of their reasonable cost, unique properties and interdisciplinary emerging applications. The present paper reports the synthesis of aluminium nanoparticles in the mixture of Deionized water (DI water) and Polyethylene Glycol (PEG) using a developed micro-Electrical Discharge Machining (μ-EDM) method. PEG was used as a stabilizer to prevent nanoparticles from agglomeration produced during the μ -EDM process. The synthesized aluminium nanoparticles were examined by Transmission Electron Microscopy (TEM), Energy Dispersive Analysis by X-rays (EDAX) and Selected Area Electron Diffraction (SAED) pattern to determine their size, shape, chemical nature and crystal structure. The average size of the polyhedral aluminium nanoparticles is found to be 196 nm.

Design and development of JUNO event data model

NASA Astrophysics Data System (ADS)

Li, Teng; Xia, Xin; Huang, Xing-Tao; Zou, Jia-Heng; Li, Wei-Dong; Lin, Tao; Zhang, Kun; Deng, Zi-Yan

2017-06-01

The Jiangmen Underground Neutrino Observatory (JUNO) detector is designed to determine the neutrino mass hierarchy and precisely measure oscillation parameters. The general purpose design also allows measurements of neutrinos from many terrestrial and non-terrestrial sources. The JUNO Event Data Model (EDM) plays a central role in the offline software system. It describes the event data entities through all processing stages for both simulated and collected data, and provides persistency via the input/output system. Also, the EDM is designed to enable flexible event handling such as event navigation, as well as the splitting of MC IBD signals and mixing of MC backgrounds. This paper describes the design, implementation and performance of the JUNO EDM. Supported by Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1532258), the Program for New Century Excellent Talents in University (NCET-13-0342), the Shandong Natural Science Funds for Distinguished Young Scholar (JQ201402) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA10010900)

Numerical study on the splitting of a vapor bubble in the ultrasonic assisted EDM process with the curved tool and workpiece.

PubMed

Shervani-Tabar, M T; Seyed-Sadjadi, M H; Shabgard, M R

2013-01-01

Electrical discharge machining (EDM) is a powerful and modern method of machining. In the EDM process, a vapor bubble is generated between the tool and the workpiece in the dielectric liquid due to an electrical discharge. In this process dynamic behavior of the vapor bubble affects machining process. Vibration of the tool surface affects bubble behavior and consequently affects material removal rate (MRR). In this paper, dynamic behavior of the vapor bubble in an ultrasonic assisted EDM process after the appearance of the necking phenomenon is investigated. It is noteworthy that necking phenomenon occurs when the bubble takes the shape of an hour-glass. After the appearance of the necking phenomenon, the vapor bubble splits into two parts and two liquid jets are developed on the boundaries of the upper and lower parts of the vapor bubble. The liquid jet developed on the upper part of the bubble impinges to the tool and the liquid jet developed on the lower part of the bubble impinges to the workpiece. These liquid jets cause evacuation of debris from the gap between the tool and the workpiece and also cause erosion of the workpiece and the tool. Curved tool and workpiece affect the shape and the velocity of the liquid jets during splitting of the vapor bubble. In this paper dynamics of the vapor bubble after its splitting near the curved tool and workpiece is investigated in three cases. In the first case surfaces of the tool and the workpiece are flat, in the second case surfaces of the tool and the workpiece are convex and in the third case surfaces of the tool and workpiece are concave. Numerical results show that in the third case, the velocity of liquid jets which are developed on the boundaries of the upper and lower parts of the vapor bubble after its splitting have the highest magnitude and their shape are broader than the other cases. Copyright © 2012 Elsevier B.V. All rights reserved.

A monolithic deformable mirror with latchable mechanical actuation (LATCHAMAN) for space-borne telescopes

NASA Astrophysics Data System (ADS)

Enya, Keigo; Kataza, Hirokazu; Fukushima, Mitsuhiro; Mitsui, Kenji; Okada, Norio; Iwashita, Hikaru; Haze, Kanae; Takahashi, Aoi; Kotani, Takayuki; Yamamuro, Tomoyasu; Kobayashi, Hitomi

2014-09-01

We present the concept, design, fabrication, and evaluation of a new deformable mirror (DM), which is latchable, compact, and designed to be applicable for cryogenic environments. The main body of a prototype DM was fabricated from a monolithic cuboid of aluminum using wire electrical discharge machining (EDM). A flexible structure was constructed inside the block by 3-dimensionally crossed hollowing using the EDM. The prototype has 6 × 6 channels, and its volume is 27 mm × 27 mm × 30 mm. The mirror was formed on the surface of the aluminum block using a highprecision NC lathe. The surface figure of the mirror was evaluated and 34 nm rms was obtained. The evaluated surface roughness for the center and off-center areas of the mirror was 9.2 nm rms and 7.6 nm rms, respectively Screws set at the back of the block deform the mirror via springs and the internal flexible structure. We present our first demonstration of deformation of the mirror carried out at ambient temperature. The relationship between the displacement of the screws and the deformation of the mirror was evaluated. Consequently, a linear relationship was confirmed, and no significant hysteresis was found. The application of such mirrors to telescopes used for various different objectives is discussed. We conclude that a DM based on our concept can be used for wavefront correction of space-borne telescopes, especially in the infrared wavelength region.

Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches

NASA Technical Reports Server (NTRS)

Smith, Stephen W.; Newman, John A.; Piascik, Robert S.

2003-01-01

Uniaxial fatigue tests were conducted to compare the fatigue life of laboratory produced corrosion pits, similar to those observed in the shuttle main landing gear wheel bolt-hole, and an electro-discharged-machined (EDM) flaw. EDM Jaws are used to simulate corrosion pits during shuttle wheel (dynamometer) testing. The aluminum alloy, (AA 7050) laboratory fatigue tests were conducted to simulate the local stress level contained in the wheel bolt-hole. Under this high local stress condition, the EDM notch produced a fatigue life similar to test specimens containing corrosion pits of similar size. Based on the laboratory fatigue test results, the EDM Jaw (semi-circular disc shaped) produces a local stress state similar to corrosion pits and can be used to simulate a corrosion pit during the shuttle wheel dynamometer tests.

Colliding or co-rotating ion beams in storage rings for EDM search

NASA Astrophysics Data System (ADS)

Koop, I. A.

2015-11-01

A new approach to search for and measure the electric dipole moment (EDM) of the proton, deuteron and some other light nuclei is presented. The idea of the method is to store two ion beams, circulating with different velocities, in a storage ring with crossed electric and magnetic guiding fields. One beam is polarized and its EDM is measured using the so-called ‘frozen spin’ method. The second beam, which is unpolarized, is used as a co-magnetometer, sensitive to the radial component of the ring’s magnetic field. The particle’s magnetic dipole moment (MDM) couples to the radial magnetic field and mimics the EDM signal. Measuring the relative vertical orbit separation of the two beams, caused by the presence of the radial magnetic field, one can control the unwanted MDM spin precession. Examples of the parameters for EDM storage rings for protons and other species of ions are presented. The use of crossed electric and magnetic fields helps to reduce the size of the ring by a factor of 10-20. We show that the bending radius of such an EDM storage ring could be about 2-3 m. Finally, a new method of increasing the spin coherence time, the so-called ‘spin wheel’, is proposed and its applicability to the EDM search is discussed.

Optimization of Maghemite (γ-Fe2O3) Nano-Powder Mixed micro-EDM of CoCrMo with Multiple Responses Using Gray Relational Analysis (GRA)

NASA Astrophysics Data System (ADS)

Mejid Elsiti, Nagwa; Noordin, M. Y.; Idris, Ani; Saed Majeed, Faraj

2017-10-01

This paper presents an optimization of process parameters of Micro-Electrical Discharge Machining (EDM) process with (γ-Fe2O3) nano-powder mixed dielectric using multi-response optimization Grey Relational Analysis (GRA) method instead of single response optimization. These parameters were optimized based on 2-Level factorial design combined with Grey Relational Analysis. The machining parameters such as peak current, gap voltage, and pulse on time were chosen for experimentation. The performance characteristics chosen for this study are material removal rate (MRR), tool wear rate (TWR), Taper and Overcut. Experiments were conducted using electrolyte copper as the tool and CoCrMo as the workpiece. Experimental results have been improved through this approach.

INRRI-EDM/2016: the first laser retroreflector on the surface of Mars

NASA Astrophysics Data System (ADS)

Dell'Agnello, S.; Delle Monache, G.; Porcelli, L.; Boni, A.; Contessa, S.; Ciocci, E.; Martini, M.; Tibuzzi, M.; Intaglietta, N.; Salvatori, L.; Tuscano, P.; Patrizi, G.; Mondaini, C.; Lops, C.; Vittori, R.; Maiello, M.; Flamini, E.; Marchetti, E.; Bianco, G.; Mugnuolo, R.; Cantone, C.

2017-01-01

During Summer 2015 the SCF_Lab (Satellite/lunar/GNSS laser ranging/altimetry and cube/microsat Characterization Facilities Laboratory, http://www.lnf.infn.it/esperimenti/etrusco, Team of INFN-LNF, with support by ASI, carried out an intense activity of final design, manufacturing and testing in order to construct, space qualify and finally integrate INRRI-EDM/2016 on ESA's ExoMars EDM spacecraft (also dubbed "Schiaparelli"), which was successfully launched on March 14, 2016. INRRI (INstrument for landing-Roving laser Retroreflector Investigation) for the EDM (Entry descent and landing Demonstration Module) 2016 mission is a compact, lightweight, passive, maintenance-free array of eight cube corner laser retroreflectors fixed to an aluminum alloy frame through the use of silicon rubber suitable for space applications. INRRI was installed on the top panel of the EDM Central Bay on October 14, 2015. It will enable the EDM to be laser-located from Mars orbiters, through laser ranging and altimetry, lidar atmospheric observations from orbit, laser flashes emitted by orbiters, and lasercom. One or all of the above means of observation can be supported by INRRI when there is an active, laser-equipped orbiter, especially after EDM end-of-life and for a long time. INRRI goals will cover science (Mars geodesy/geophysics, future Mars test of General Relativity, GR), technology and exploration. Concerning the latter two, INRRI will support mars-georeferencing of the EDM landing site, support potential precision lidar-based landing next to the EDM, support test & diagnostics of lasercom for data exchange among Mars orbit, Mars surface and Earth, and it will be a precursor for additional Mars surface retroreflectors, for example on exploration rovers. This paper describes in detail our innovative payload, hopefully the very first to be deployed safely with the lander Schiaparelli on the Mars surface, and its space qualification for the ExoMars EDM 2016 mission. Despite the fate of the Schiaparelli landing, which is still under the investigation of ESA and the industry, this paper remains a valuable reference for next INRRI-like laser retroreflectors arrays.

Deposition and micro electrical discharge machining of CVD-diamond layers incorporated with silicon

NASA Astrophysics Data System (ADS)

Kühn, R.; Berger, T.; Prieske, M.; Börner, R.; Hackert-Oschätzchen, M.; Zeidler, H.; Schubert, A.

2017-10-01

In metal forming, lubricants have to be used to prevent corrosion or to reduce friction and tool wear. From an economical and ecological point of view, the aim is to avoid the usage of lubricants. For dry deep drawing of aluminum sheets it is intended to apply locally micro-structured wear-resistant carbon based coatings onto steel tools. One type of these coatings are diamond layers prepared by chemical vapor deposition (CVD). Due to the high strength of diamond, milling processes are unsuitable for micro-structuring of these layers. In contrast to this, micro electrical discharge machining (micro EDM) is a suitable process for micro-structuring CVD-diamond layers. Due to its non-contact nature and its process principle of ablating material by melting and evaporating, it is independent of the hardness, brittleness or toughness of the workpiece material. In this study the deposition and micro electrical discharge machining of silicon incorporated CVD-diamond (Si-CVD-diamond) layers were presented. For this, 10 µm thick layers were deposited on molybdenum plates by a laser-induced plasma CVD process (LaPlas-CVD). For the characterization of the coatings RAMAN- and EDX-analyses were conducted. Experiments in EDM were carried out with a tungsten carbide tool electrode with a diameter of 90 µm to investigate the micro-structuring of Si-CVD-diamond. The impact of voltage, discharge energy and tool polarity on process speed and resulting erosion geometry were analyzed. The results show that micro EDM is a suitable technology for micro-structuring of silicon incorporated CVD-diamond layers.

Entre Dos Mundos/Between Two Worlds: Youth Violence Prevention for Acculturating Latino Families

ERIC Educational Resources Information Center

Smokowski, Paul R.; Bacallao, Martica

2009-01-01

Objective: This study evaluated the efficacy of Entre Dos Mundos/Between Two Worlds (EDM) prevention for Latino adolescents. Method: In an experimental trial to compare implementation formats, 41 Latino families were randomly assigned to EDM action-oriented skills training groups, and 47 families were randomly assigned to unstructured EDM support…

Techniques used to search for a permanent electric dipole moment of the 199Hg atom and the implications for CP violation

NASA Astrophysics Data System (ADS)

Swallows, M. D.; Loftus, T. H.; Griffith, W. C.; Heckel, B. R.; Fortson, E. N.; Romalis, M. V.

2013-01-01

We discuss in detail the search for a permanent electric dipole moment (EDM) of the 199Hg atom reported by Griffith [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.102.101601 102, 101601 (2009)]. The upper bound, d(199Hg)<3.1×10-29 e cm (95% C.L.), is a factor of 7 improvement over the best previous EDM limit for 199Hg, provides the most sensitive probe to date for EDMs in diamagnetic atoms, and sets new limits on time-reversal symmetry violation in extensions to the standard model. This paper provides extensive discussion of the techniques used to search for the 199Hg EDM and the implications of the new 199Hg EDM limit for CP violation in elementary particle interactions.

The prevalence of the extensor digiti minimi tendon of the hand and its variants in humans: a systematic review and meta-analysis.

PubMed

Yammine, Kaissar

2015-01-01

The extensor digiti minimi (EDM) is frequently used in the case of an abduction deformity of the little finger. It is also considered as a main resource for tendon transfer. However, it shows many variations in the human hand, which include splitting into two or more slips and sending a slip to the fourth finger, named the extensor digiti minimi et quarti (EDMQ). The aim of this systematic review is to perform an evidence synthesis on the prevalence of the EDM and its variants. Twenty-six cadaveric studies met the inclusion criteria with a total of 2247 hands. Meta-analysis results yielded an overall pooled prevalence estimate (PPE) of the EDM of 99.7% and PPEs of 11.5, 77.6, 7 and 0.6% for the single-, double-, triple- and quadruple-slip EDM, respectively. For the single-slip EDM, the frequencies were such that Indians > Middle Eastern > Europeans > Japanese > North Americans. For the double-slip EDM, the frequencies were such that Japanese > North Americans = Europeans > Middle Eastern > Indians. No significance was found with regard to hand side. The true EDMQ prevalence was found to be at 7.3%, whereas its crude prevalence was 8%. This artilce offers reference values on the prevalence of the EDM and its variants, which are thought to be highly relevant to both anatomists and clinicians.

Foil Gas Thrust Bearings for High-Speed Turbomachinery

NASA Technical Reports Server (NTRS)

Edmonds, Brian; DellaCorte, Christopher; Dykas, Brian

2010-01-01

A methodology has been developed for the design and construction of simple foil thrust bearings intended for parametric performance testing and low marginal costs, supporting continued development of oil-free turbomachinery. A bearing backing plate is first machined and surface-ground to produce flat and parallel faces. Partial-arc slots needed to retain the foil components are then machined into the plate by wire electrical discharge machining. Slot thicknesses achievable by a single wire pass are appropriate to accommodate the practical range of foil thicknesses, leaving a small clearance in this hinged joint to permit limited motion. The backing plate is constructed from a nickel-based superalloy (Inconel 718) to allow heat treatment of the entire assembled bearing, as well as to permit hightemperature operation. However, other dimensionally stable materials, such as precipitation-hardened stainless steel, can also be used for this component depending on application. The top and bump foil blanks are cut from stacks of annealed Inconel X-750 foil by the same EDM process. The bump foil has several azimuthal slits separating it into five individual bump strips. This configuration allows for variable bump spacing, which helps to accommodate the effects of the varying surface velocity, thermal crowning, centrifugal dishing, and misalignment. Rectangular tabs on the foil blanks fit into the backing plate slots. For this application, a rather traditional set of conventionally machined dies is selected, and bump foil blanks are pressed into the dies for forming. This arrangement produces a set of bump foil dies for foil thrust bearings that provide for relatively inexpensive fabrication of various bump configurations, and employing methods and features from the public domain.

Proceedings of the International Conference on Educational Data Mining (EDM) (2nd, Cordoba, Spain, July 1-3, 2009)

ERIC Educational Resources Information Center

Barnes, Tiffany, Ed.; Desmarais, Michel, Ed.; Romero, Cristobal, Ed.; Ventura, Sebastian, Ed.

2009-01-01

The Second International Conference on Educational Data Mining (EDM2009) was held at the University of Cordoba, Spain, on July 1-3, 2009. EDM brings together researchers from computer science, education, psychology, psychometrics, and statistics to analyze large data sets to answer educational research questions. The increase in instrumented…

77 FR 68140 - Privacy Act of 1974; New System of Records, Office of General Counsel E-Discovery Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

... System of Records, Office of General Counsel E-Discovery Management System: Republication of System... Counsel (OGC) E- Discovery Management System (EDMS). EDMS was first announced and described in a July 17... for OGC's E-Discovery Management System (OGC-EDMS), a system expected to significantly improve the...

Pedigree Analysis and Exclusion of Alpha-Tocopherol Transfer Protein (TTPA) as a Candidate Gene for Neuroaxonal Dystrophy in the American Quarter Horse

PubMed Central

Finno, C.J.; Famula, T.; Aleman, M.; Higgins, R.J.; Madigan, J.E.; Bannasch, D.L.

2015-01-01

Background Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) is a neurodegenerative disorder affecting young horses of various breeds that resembles ataxia with vitamin E deficiency in humans, an inherited disorder caused by mutations in the alpha-tocopherol transfer protein gene (TTPA). To evaluate variants found upon sequencing TTPA in the horse, the mode of inheritance for NAD/EDM had to be established. Hypothesis NAD/EDM in the American Quarter Horse (QH) is caused by a mutation in TTPA. Animals 88 clinically phenotyped (35 affected [ataxia score ≥2], 53 unaffected) QHs with a diagnosis of NAD/EDM with 6 affected and 4 unaffected cases confirmed at postmortem examination. Procedures Pedigrees and genotypes across 54,000 single nucleotide polymorphism (SNP) markers were assessed to determine heritability and mode of inheritance of NAD/EDM. TTPA sequence of exon/intron boundaries was evaluated in 2 affected and 2 control horses. An association analysis was performed by 71 SNPs surrounding TTPA and 8 SNPs within TTPA that were discovered by sequencing. RT-PCR for TTPA was performed on mRNA from the liver of 4 affected and 4 control horses. Results Equine NAD/EDM appears to be inherited as a polygenic trait and, within this family of QHs, demonstrates high heritability. Sequencing of TTPA identified 12 variants. No significant association was found using the 79 available variants in and surrounding TTPA. RT-PCR yielded PCR products of equivalent sizes between affected cases and controls. Conclusions and Clinical Importance NAD/EDM demonstrates heritability in this family of QHs. Variants in TTPA are not responsible for NAD/EDM in this study population. PMID:23186252

Field Modeling, Symplectic Tracking, and Spin Decoherence for EDM and Muon $$g\\textrm{-}2$$ Lattices

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

Valetov, Eremey Vladimirovich

2017-01-01

While the first particle accelerators were electrostatic machines, and several electrostatic storage rings were subsequently commissioned and operated, electrostatic storage rings pose a number of challenges. Unlike motion in the magnetic field, where particle energy remains constant, particle energy generally changes in electrostatic elements. Conservation of energy in an electrostatic element is, in practice, only approximate, and it requires careful and accurate design, manufacturing, installation, and operational use. Electrostatic deflectors require relatively high electrostatic fields, tend to introduce nonlinear aberrations of all orders, and are more challenging to manufacture than homogeneous magnetic dipoles. Accordingly, magnetic storage rings are overwhelmingly prevalent.more » The search for electric dipole moments (EDMs) of fundamental particles is of key importance in the study of C and CP violations and their sources. C and CP violations are part of the Sakharov conditions that explain the matter–antimatter asymmetry in the universe. Determining the source of CP violations would provide valuable empirical insight for beyond-Standard-Model physics. EDMs of fundamental particles have not to this date been experimentally observed. The search for fundamental particle EDMs has narrowed the target search region; however, an EDM signal is yet to be discovered. In 2008, Brookhaven National Laboratory (BNL) had proposed the frozen spin (FS) concept for the search of a deuteron EDM. The FS concept envisions launching deuterons through a storage ring with combined electrostatic and magnetic fields. The electrostatic and magnetic fields are in a proportion that would, without an EDM, freeze the deuteron’s spin along its momentum as the deuteron moves around the lattice. The radial electrostatic field would result in a torque on the spin vector, proportional to a deuteron EDM, rotating the spin vector out of the midplane.« less

Lorentz-violating contributions to the nuclear Schiff moment and nuclear EDM

NASA Astrophysics Data System (ADS)

Araujo, Jonas B.; Casana, Rodolfo; Ferreira, Manoel M.

2018-03-01

In the context of an atom endowed with nuclear electric dipole moments (EDM), we consider the effects on the Schiff moment of C P T -even Lorentz-violating (LV) terms that modify the Coulomb potential. First, we study the modifications on the Schiff moment when the nucleus interacts with the electronic cloud by means of a Coulomb potential altered only by the P -even LV components. Next, by supposing the existence of an additional intrinsic LV EDM generated by other LV sources, we assess the corrections to the Schiff moment when the interaction nucleus-electrons runs mediated by a Coulomb potential modified by both the P -odd and P -even LV components. We then use known estimates and EDM measurements to discuss upper bounds on the new Schiff moment components and the possibility of a nuclear EDM component ascribed to LV effects.

Microcomputer pollution model for civilian airports and Air Force bases. Model description

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

Segal, H.M.; Hamilton, P.L.

1988-08-01

This is one of three reports describing the Emissions and Dispersion Modeling System (EDMS). EDMS is a complex source emissions/dispersion model for use at civilian airports and Air Force bases. It operates in both a refined and a screening mode and is programmed for an IBM-XT (or compatible) computer. This report--MODEL DESCRIPTION--provides the technical description of the model. It first identifies the key design features of both the emissions (EMISSMOD) and dispersion (GIMM) portions of EDMS. It then describes the type of meteorological information the dispersion model can accept and identifies the manner in which it preprocesses National Climatic Centermore » (NCC) data prior to a refined-model run. The report presents the results of running EDMS on a number of different microcomputers and compares EDMS results with those of comparable models. The appendices elaborate on the information noted above and list the source code.« less

Top down electroweak dipole operators

NASA Astrophysics Data System (ADS)

Fuyuto, Kaori; Ramsey-Musolf, Michael

2018-06-01

We derive present constraints on, and prospective sensitivity to, the electric dipole moment (EDM) of the top quark (dt) implied by searches for the EDMs of the electron and nucleons. Above the electroweak scale v, the dt arises from two gauge invariant operators generated at a scale Λ ≫ v that also mix with the light fermion EDMs under renormalization group evolution at two-loop order. Bounds on the EDMs of first generation fermion systems thus imply bounds on |dt |. Working in the leading log-squared approximation, we find that the present upper bound on |dt | is 10-19 e cm for Λ = 1 TeV, except in regions of finely tuned cancellations that allow for |dt | to be up to fifty times larger. Future de and dn probes may yield an order of magnitude increase in dt sensitivity, while inclusion of a prospective proton EDM search may lead to an additional increase in reach.

5 CFR 850.301 - Electronic records; other acceptable records.

Code of Federal Regulations, 2014 CFR

2014-01-01

... SERVICE REGULATIONS (CONTINUED) ELECTRONIC RETIREMENT PROCESSING Records § 850.301 Electronic records; other acceptable records. (a) Acceptable electronic records for retirement and insurance processing by... (SF 2806 or SF 3100), or data or images obtained from such documents, including images stored in EDMS...

The Power of Imaging.

ERIC Educational Resources Information Center

Haapaniemi, Peter

1990-01-01

Describes imaging technology, which allows huge numbers of words and illustrations to be reduced to tiny fraction of space required by originals and discusses current applications. Highlights include image processing system at National Archives; use by banks for high-speed check processing; engineering document management systems (EDMS); folder…

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

Chen, Ching-Fong; Pokharel, Reeju; Brand, Michael J.

Here, we developed a copper/tungsten (Cu/W) composite for mesoscale Materials Science applications using the novel High-Energy Diffraction Microscopy (HEDM) technique. Argon-atomized copper powder was selected as the starting raw powder and screened to remove the extremely large particle fraction. Tungsten particles were collected by milling and screening the -325 mesh tungsten powder between 500 and 635 mesh sieves. Hot pressing of screened Cu powder was performed at 900 °C in Ar/4 %H 2 atmosphere. XRD and ICP results show that the hot-pressed Cu sample consists of about 5 vol% Cu 2O, which is caused by the presence of oxygen onmore » the surface of the starting Cu powder. Hot pressing the copper powder in a pure hydrogen atmosphere was successful in removing most of the surface oxygen. Our process was also implemented for hot pressing the Cu/W composite. The density of the Cu/W composites hot pressed at 950 °C in pure hydrogen was about 94 % of the theoretical density (TD). The hot-pressed Cu/W composites were further hot isostatic pressed at 1050 °C in argon atmosphere, which results in 99.6 % of the TD with the designed Cu grain size and W particle distribution. Tensile specimens with D-notch were machined using the wire EDM method. Furthermore, the processing and consolidation of these materials will be discussed in detail. The HEDM images are also showed and discussed.« less

Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States

EPA Science Inventory

The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States. (UNH)

EPA Science Inventory

The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

Improved experimental limit on the EDM of 225Ra

NASA Astrophysics Data System (ADS)

Bishof, Michael; Bailey, Kevin; Dietrich, Matthew R.; Greene, John P.; Holt, Roy J.; Kalita, Mukut R.; Korsch, Wolfgang; Lemke, Nathan D.; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Tom P.; Parker, Richard H.; Rabga, Tenzin; Singh, Jaideep T.

2015-10-01

Searches for permanent electric dipole moments (EDMs) in fundamental and composite particles are sensitive probes of beyond-standard-model symmetry violation that could explain the dominance of matter over anti-matter. The 225Ra (t1/2 = 15d, I = 1/2) atom is a particularly attractive system to use for an EDM measurement because its large nuclear octupole deformation, closely spaced ground-state parity doublet, and large atomic mass make 225Ra uniquely sensitive to symmetry-violating interactions in the nuclear medium. We have developed an experiment to measure the EDM of 225Ra and demonstrated the first ``proof-of-principle'' measurement, giving a 95% confidence upper limit of 5E-22 e-cm. After implementing a vacuum upgrade, we have observed nuclear spin coherence after 20 s of free evolution - a factor of ten improvement over our earlier results - and have lowered the 225Ra EDM limit by over an order of magnitude. Upcoming experimental upgrades have the potential to further improve our EDM sensitivity by many orders of magnitude, allowing us to test symmetry violation at an unprecedented level. This work is supported by U.S. DOE, Office of Science, Office of Nuclear Physics, under Contract DE-AC02-06CH11357.

Lepton electric dipole moment and strong CP violation

NASA Astrophysics Data System (ADS)

Ghosh, Diptimoy; Sato, Ryosuke

2018-02-01

Contribution of the strong CP angle, θ bar , to the Wilson Coefficients of electron and muon electric dipole moment (EDM) operators are discussed. Previously, θ bar contribution to the electron EDM operator was calculated by Choi and Hong [1]. However, the effect of CP-violating three meson coupling was missing in [1]. We include this missing contribution for the first time in the literature, and reevaluate the Wilson coefficients of the lepton EDM operator. We obtain de = - (2.2 - 8.6) ×10-28 θ bar e-cm which is 15-70% of the result obtained in [1]. We also estimated the muon EDM as dμ = - (0.5 - 1.8) ×10-25 θ bar e-cm. Using | θ bar | ≲10-10 suggested by the neutron EDM measurements, we obtain |de | ≲ 8.6 ×10-38e-cm and |dμ | ≲ 1.8 ×10-35e-cm. The θ bar contribution to the muon EDM is much below the sensitivities of the current and near future experiments. Our result shows that the θ bar contribution to de,μ can be larger than the CKM contributions by many orders of magnitude.

ɛ '/ ɛ anomaly and neutron EDM in SU(2) L × SU(2) R × U(1) B- L model with charge symmetry

NASA Astrophysics Data System (ADS)

Haba, Naoyuki; Umeeda, Hiroyuki; Yamada, Toshifumi

2018-05-01

The Standard Model prediction for ɛ '/ ɛ based on recent lattice QCD results exhibits a tension with the experimental data. We solve this tension through W R + gauge boson exchange in the SU(2) L × SU(2) R × U(1) B- L model with `charge symmetry', whose theoretical motivation is to attribute the chiral structure of the Standard Model to the spontaneous breaking of SU(2) R × U(1) B- L gauge group and charge symmetry. We show that {M_W}{_R}<58 TeV is required to account for the ɛ' /ɛ anomaly in this model. Next, we make a prediction for the neutron EDM in the same model and study a correlation between ɛ ' /ɛ and the neutron EDM. We confirm that the model can solve the ɛ ' /ɛ anomaly without conflicting the current bound on the neutron EDM, and further reveal that almost all parameter regions in which the ɛ ' /ɛ anomaly is explained will be covered by future neutron EDM searches, which leads us to anticipate the discovery of the neutron EDM.

Analysis of copper mixed kerosene servotherm in EDM of Monel 400™

NASA Astrophysics Data System (ADS)

Anandakumar, P. A.; Molla, Baya; Biruke, Fisha; Aravind, S.

2017-05-01

Powder mixed electro discharge machine process (PMEDM) is a hybrid machine process where a conductive powders is mixed to the dielectric fluid to facilitate effective machining of advanced material. This present study focused on performance of copper mixed kerosene servotherm as dielectric medium in EDM of Monel 400TM. The ratio of kerosene sevothermis 75 : 25. The copper powder was mixed with dielectric medium of kerosene servothem of 6g, 8g and 10 g respectively. This mixture was analyzed using different current rate of 8 amps, 10 amps and 12 amps to know the performance characteristics by using material removal rate, tool wear rate, diameter overcut, surface finish and dimensional accuracy. Based on the experimental investigation it is concluded that copper powder of 10g with 10 amps performed well than that of all other parameters.

Electro-thermal modelling of anode and cathode in micro-EDM

NASA Astrophysics Data System (ADS)

Yeo, S. H.; Kurnia, W.; Tan, P. C.

2007-04-01

Micro-electrical discharge machining is an evolution of conventional EDM used for fabricating three-dimensional complex micro-components and microstructure with high precision capabilities. However, due to the stochastic nature of the process, it has not been fully understood. This paper proposes an analytical model based on electro-thermal theory to estimate the geometrical dimensions of micro-crater. The model incorporates voltage, current and pulse-on-time during material removal to predict the temperature distribution on the workpiece as a result of single discharges in micro-EDM. It is assumed that the entire superheated area is ejected from the workpiece surface while only a small fraction of the molten area is expelled. For verification purposes, single discharge experiments using RC pulse generator are performed with pure tungsten as the electrode and AISI 4140 alloy steel as the workpiece. For the pulse-on-time range up to 1000 ns, the experimental and theoretical results are found to be in close agreement with average volume approximation errors of 2.7% and 6.6% for the anode and cathode, respectively.

Processing and consolidation of copper/tungsten

DOE PAGES

Chen, Ching-Fong; Pokharel, Reeju; Brand, Michael J.; ...

2016-09-27

Here, we developed a copper/tungsten (Cu/W) composite for mesoscale Materials Science applications using the novel High-Energy Diffraction Microscopy (HEDM) technique. Argon-atomized copper powder was selected as the starting raw powder and screened to remove the extremely large particle fraction. Tungsten particles were collected by milling and screening the -325 mesh tungsten powder between 500 and 635 mesh sieves. Hot pressing of screened Cu powder was performed at 900 °C in Ar/4 %H 2 atmosphere. XRD and ICP results show that the hot-pressed Cu sample consists of about 5 vol% Cu 2O, which is caused by the presence of oxygen onmore » the surface of the starting Cu powder. Hot pressing the copper powder in a pure hydrogen atmosphere was successful in removing most of the surface oxygen. Our process was also implemented for hot pressing the Cu/W composite. The density of the Cu/W composites hot pressed at 950 °C in pure hydrogen was about 94 % of the theoretical density (TD). The hot-pressed Cu/W composites were further hot isostatic pressed at 1050 °C in argon atmosphere, which results in 99.6 % of the TD with the designed Cu grain size and W particle distribution. Tensile specimens with D-notch were machined using the wire EDM method. Furthermore, the processing and consolidation of these materials will be discussed in detail. The HEDM images are also showed and discussed.« less

Pigment retinopathy in warmblood horses with equine degenerative myeloencephalopathy and equine motor neuron disease.

PubMed

Finno, Carrie J; Kaese, Heather J; Miller, Andrew D; Gianino, Giuliana; Divers, Thomas; Valberg, Stephanie J

2017-07-01

A pigment retinopathy has been reported in adult horses with equine motor neuron disease (EMND) arising from chronic α-tocopherol (α-TP) deficiency. A pigment retinopathy has not been identified in horses with neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) that affects genetically susceptible young horses with α-TP deficiency. The objective of this report is to describe, for the first time, a pigment retinopathy in a family of α-TP-deficient Warmbloods (WB) with clinically apparent NAD/EDM or EMND. Twenty-five WB horses from one farm underwent complete neurologic and ophthalmic examinations and serum α-TP concentrations were assessed. Two of the most severely ataxic horses were euthanized and postmortem examinations performed. Alpha-TP deficiency was widespread on this farm (22 of 25 horses). Eleven of 25 horses were clinically normal (age range 2-12 years), one had signs of EMND (6 years of age), 10 had signs of ataxia consistent with NAD/EDM (1-10 years), and two of these were postmortem confirmed concurrent NAD/EDM and EMND. A pigment retinopathy characterized by varying amounts of granular dark pigment in the tapetal retina was observed in four clinically apparent NAD/EDM horses (two postmortem confirmed concurrent NAD/EDM and EMND) and one horse with clinical signs of EMND. A pigment retinopathy can be present in young α-TP-deficient Warmblood horses with clinical signs of EMND as well as those with signs of NAD/EDM. © 2016 American College of Veterinary Ophthalmologists.

Proceedings of the International Conference on Educational Data Mining (EDM) (5th, Chania, Greece, June 19-21, 2012)

ERIC Educational Resources Information Center

International Educational Data Mining Society, 2012

2012-01-01

The 5th International Conference on Educational Data Mining (EDM 2012) is held in picturesque Chania on the beautiful Crete island in Greece, under the auspices of the International Educational Data Mining Society (IEDMS). The EDM 2012 conference is a leading international forum for high quality research that mines large data sets of educational…

Neutron Electric Dipole Moment and Tensor Charges from Lattice QCD.

PubMed

Bhattacharya, Tanmoy; Cirigliano, Vincenzo; Gupta, Rajan; Lin, Huey-Wen; Yoon, Boram

2015-11-20

We present lattice QCD results on the neutron tensor charges including, for the first time, a simultaneous extrapolation in the lattice spacing, volume, and light quark masses to the physical point in the continuum limit. We find that the "disconnected" contribution is smaller than the statistical error in the "connected" contribution. Our estimates in the modified minimal subtraction scheme at 2 GeV, including all systematics, are g_{T}^{d-u}=1.020(76), g_{T}^{d}=0.774(66), g_{T}^{u}=-0.233(28), and g_{T}^{s}=0.008(9). The flavor diagonal charges determine the size of the neutron electric dipole moment (EDM) induced by quark EDMs that are generated in many new scenarios of CP violation beyond the standard model. We use our results to derive model-independent bounds on the EDMs of light quarks and update the EDM phenomenology in split supersymmetry with gaugino mass unification, finding a stringent upper bound of d_{n}<4×10^{-28} e cm for the neutron EDM in this scenario.

Control of systematic uncertainties in the storage ring search for an electric dipole moment by measuring the electric quadrupole moment

NASA Astrophysics Data System (ADS)

Magiera, Andrzej

2017-09-01

Measurements of electric dipole moment (EDM) for light hadrons with use of a storage ring have been proposed. The expected effect is very small, therefore various subtle effects need to be considered. In particular, interaction of particle's magnetic dipole moment and electric quadrupole moment with electromagnetic field gradients can produce an effect of a similar order of magnitude as that expected for EDM. This paper describes a very promising method employing an rf Wien filter, allowing to disentangle that contribution from the genuine EDM effect. It is shown that both these effects could be separated by the proper setting of the rf Wien filter frequency and phase. In the EDM measurement the magnitude of systematic uncertainties plays a key role and they should be under strict control. It is shown that particles' interaction with field gradients offers also the possibility to estimate global systematic uncertainties with the precision necessary for an EDM measurement with the planned accuracy.

Los Alamos nEDM Experiment and Demonstration of Ramsey's Method on Stored UCNs at the LANL UCN Source

NASA Astrophysics Data System (ADS)

Clayton, Steven; Chupp, Tim; Cude-Woods, Christopher; Currie, Scott; Ito, Takeyasu; Liu, Chen-Yu; Long, Joshua; MacDonald, Stephen; Makela, Mark; O'Shaughnessy, Christopher; Plaster, Brad; Ramsey, John; Saunders, Andy; LANL nEDM Collaboration

2017-09-01

The Los Alamos National Laboratory ultracold neutron (UCN) source was recently upgraded for a factor of 5 improvement in stored density, providing the statistical precision needed for a room temperature neutron electric dipole moment measurement with sensitivity 3 ×10-27 e . cm, a factor 10 better than the limit set by the Sussex-RAL-ILL experiment. Here, we show results of a demonstration of Ramsey's separated oscillatory fields method on stored UCNs at the LANL UCN source and in a geometry relevant for a nEDM measurement. We argue a world-leading nEDM experiment could be performed at LANL with existing technology and a short lead time, providing a physics result with sensitivity intermediate between the current limit set by Sussex-RAL-ILL, and the anticipated limit from the complex, cryogenic nEDM experiment planned for the next decade at the ORNL Spallation Neutron Source (SNS-nEDM). This work was supported by the Los Alamos LDRD Program, Project 20140015DR.

Parametric study and characterization of the isobaric thermomechanical transformation fatigue of nickel-rich NiTi SMA actuators

NASA Astrophysics Data System (ADS)

Bertacchini, Olivier W.; Schick, Justin; Lagoudas, Dimitris C.

2009-03-01

The recent development of various aerospace applications utilizing Ni-rich NiTi Shape memory Alloys (SMAs) as actuators motivated the need to characterize the cyclic response and the transformation fatigue behavior of such alloys. The fatigue life validation and certification of new designs is required in order to be implemented and used in future applications. For that purpose, a custom built fatigue test frame was designed to perform isobaric thermally induced transformation cycles on small dogbones SMA actuators (test gauge cross-section up to: 1.270 x 0.508 mm2). A parametric study on the cyclic response and transformation fatigue behavior of Ni-rich NiTi SMAs led to the optimization of several material/process and test parameters, namely: the applied stress range, the heat treatment, the heat treatment environment and the specimen thickness. However, fatigue testing was performed in a chilled waterless glycol environment maintained at a temperature of 5°C that showed evidence of corrosion-assisted transformation fatigue failure. Therefore, it was necessary to build a fatigue test frame that would employ a dry and inert cooling methodology to get away from any detrimental interactions between the specimens and the cooling medium (corrosion). The selected cooling method was gaseous nitrogen, sprayed into a thermally insulated chamber, maintaining a temperature of -20°C. The design of the gaseous nitrogen cooling was done in such a way that the actuation frequency is similar to the one obtained using the original design (~ 0.1 Hz). For both cooling methods, Joule resistive heating was used to heat the specimens. In addition and motivated by the difference in surface quality resulting from different material processing such as EDM wire cutting and heat treatments, EDM recast layer and oxide layer were removed. The removal was followed by an ultra-fine polish (0.05 μm) that was performed on a subset of the fatigue specimens. Experimental results are presented for full actuation of the SMA actuators and are given in terms of applied stress, accumulated plastic strain and number of cycles to failure. In addition, the assessment of the influence of the surface quality is supported by fatigue tests results and post-failure microstructure analysis.

Estimation of tool wear compensation during micro-electro-discharge machining of silicon using process simulation

NASA Astrophysics Data System (ADS)

Muralidhara, .; Vasa, Nilesh J.; Singaperumal, M.

2010-02-01

A micro-electro-discharge machine (Micro EDM) was developed incorporating a piezoactuated direct drive tool feed mechanism for micromachining of Silicon using a copper tool. Tool and workpiece materials are removed during Micro EDM process which demand for a tool wear compensation technique to reach the specified depth of machining on the workpiece. An in-situ axial tool wear and machining depth measurement system is developed to investigate axial wear ratio variations with machining depth. Stepwise micromachining experiments on silicon wafer were performed to investigate the variations in the silicon removal and tool wear depths with increase in tool feed. Based on these experimental data, a tool wear compensation method is proposed to reach the desired depth of micromachining on silicon using copper tool. Micromachining experiments are performed with the proposed tool wear compensation method and a maximum workpiece machining depth variation of 6% was observed.

[Proceedings of the] International Conference on Educational Data Mining (EDM) (3rd, Pittsburgh, PA, July 11-13, 2010)

ERIC Educational Resources Information Center

Baker, Ryan S. J. d., Ed.; Merceron, Agathe, Ed.; Pavlik, Philip I., Jr., Ed.

2010-01-01

The Third International Conference on Data Mining (EDM 2010) was held in Pittsburgh, PA, USA. It follows the second conference at the University of Cordoba, Spain, on July 1-3, 2009 and the first edition of the conference held in Montreal in 2008, and a series of workshops within the AAAI, AIED, EC-TEL, ICALT, ITS, and UM conferences. EDM 2011…

Search for the permanent electric dipole moment of 129Xe

NASA Astrophysics Data System (ADS)

Sachdeva, Natasha; Chupp, Timothy; Gong, Fei; Babcock, Earl; Salhi, Zahir; Burghoff, Martin; Fan, Isaac; Killian, Wolfgang; Knappe-Grüneberg, Silvia; Schabel, Allard; Seifert, Frank; Trahms, Lutz; Voigt, Jens; Degenkolb, Skyler; Fierlinger, Peter; Krägeloh, Eva; Lins, Tobias; Marino, Michael; Meinel, Jonas; Niessen, Benjamin; Stuiber, Stefan; Terrano, William; Kuchler, Florian; Singh, Jaideep

2017-09-01

CP-violation in Beyond-the-Standard-Model physics, necessary to explain the baryon asymmetry, gives rise to permanent electric dipole moments (EDMs). EDM measurements of the neutron, electron, paramagnetic and diamagnetic atoms constrain CP-violating parameters. The current limit for the 129Xe EDM is 6 ×10-27 e . cm (95 % CL). The HeXeEDM experiment at FRM-II (Munich Research Reactor) and BMSR-2 (Berlin Magnetically Shielded Room) uses a stable magnetic field in a magnetically shielded room and 3He comagnetometer with potential to improve the limit by two orders of magnitude. Polarized 3He and 129Xe free precession is detected with SQUID magnetometers in the presence of applied electric and magnetic fields. Conclusions from recent measurements will be presented.

Effect of wear parameters on dry sliding behavior of Fly Ash/SiC particles reinforced AA 2024 hybrid composites

NASA Astrophysics Data System (ADS)

Bhaskar Kurapati, Vijaya; Kommineni, Ravindra

2017-09-01

In the present work AA 2024 alloy reinforced with mixtures of SiC and Fly Ash (FA) particles of 70 µm (5, 10 and 15 wt. %) are fabricated using the stir casting method. Both reinforcements are added in equal weight proportions. The wear test specimens are prepared from both the alloy and composite castings in the dimensions of Ф 4 mm and 30 mm lengths by the wire cut EDM process. The dry sliding wear properties of the prepared composites at room temperature are estimated by pin-on-disc wear testing equipment. The wear characteristics of the composites are studied by conducting the dry sliding wear test over loads of 0.5 Kgf, 1.0 Kgf, 1.5 Kgf, a track diameter of 60 mm and sliding times of 15 min, 30 min, 45min. The experimental results shows that the wear decreases with an increase in the weight percentage of FA and SiC particles in the matrix. Additionally wear increases with an increase in load and sliding time. Further, it is found that the wear resistance of the AA2024-Hybrid composites is higher than that of the AA2024 matrix.

78 FR 9721 - Privacy Act of 1974; New System of Records, Office of General Counsel E-Discovery Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-11

... massive emails, word processing documents, PDF files, spreadsheets, presentations, database entries, and....pdf . PURPOSES: OGC-EDMS provides OGC with a method to initiate, track, and manage the collection...

The Evolution of CERN EDMS

NASA Astrophysics Data System (ADS)

Wardzinska, Aleksandra; Petit, Stephan; Bray, Rachel; Delamare, Christophe; Garcia Arza, Griselda; Krastev, Tsvetelin; Pater, Krzysztof; Suwalska, Anna; Widegren, David

2015-12-01

Large-scale long-term projects such as the LHC require the ability to store, manage, organize and distribute large amounts of engineering information, covering a wide spectrum of fields. This information is a living material, evolving in time, following specific lifecycles. It has to reach the next generations of engineers so they understand how their predecessors designed, crafted, operated and maintained the most complex machines ever built. This is the role of CERN EDMS. The Engineering and Equipment Data Management Service has served the High Energy Physics Community for over 15 years. It is CERN's official PLM (Product Lifecycle Management), supporting engineering communities in their collaborations inside and outside the laboratory. EDMS is integrated with the CAD (Computer-aided Design) and CMMS (Computerized Maintenance Management) systems used at CERN providing tools for engineers who work in different domains and who are not PLM specialists. Over the years, human collaborations and machines grew in size and complexity. So did EDMS: it is currently home to more than 2 million files and documents, and has over 6 thousand active users. In April 2014 we released a new major version of EDMS, featuring a complete makeover of the web interface, improved responsiveness and enhanced functionality. Following the results of user surveys and building upon feedback received from key users group, we brought what we think is a system that is more attractive and makes it easy to perform complex tasks. In this paper we will describe the main functions and the architecture of EDMS. We will discuss the available integration options, which enable further evolution and automation of engineering data management. We will also present our plans for the future development of EDMS.

Endometrial Carcinomas with POLE Exonuclease Domain Mutations Have a Favorable Prognosis.

PubMed

McConechy, Melissa K; Talhouk, Aline; Leung, Samuel; Chiu, Derek; Yang, Winnie; Senz, Janine; Reha-Krantz, Linda J; Lee, Cheng-Han; Huntsman, David G; Gilks, C Blake; McAlpine, Jessica N

2016-06-15

The aim of this study was to confirm the prognostic significance of POLE exonuclease domain mutations (EDM) in endometrial carcinoma patients. In addition, the effect of treatment on POLE-mutated tumors was assessed. A retrospective patient cohort of 496 endometrial carcinoma patients was identified for targeted sequencing of the POLE exonuclease domain, yielding 406 evaluable tumors. Univariable and multivariable analyses were performed to determine the effect of POLE mutation status on progression-free survival (PFS), disease-specific survival (DSS), and overall survival (OS). Combining results from eight studies in a meta-analysis, we computed pooled HR for PFS, DSS, and OS. POLE EDMs were identified in 39 of 406 (9.6%) endometrial carcinomas. Women with POLE-mutated endometrial carcinomas were younger, with stage I (92%) tumors, grade 3 (62%), endometrioid histology (82%), and frequent (49%) lymphovascular invasion. In univariable analysis, POLE-mutated endometrial carcinomas had significantly improved outcomes compared with patients with no EDMs for PFS, DSS, and OS. In multivariable analysis, POLE EDMs were only significantly associated with improved PFS. The effect of adjuvant treatment on POLE-mutated cases could not be determined conclusively; however, both treated and untreated patients with POLE EDMs had good outcomes. Meta-analysis revealed an association between POLE EDMs and improved PFS and DSS with pooled HRs 0.34 [95% confidence interval (CI), 0.15-0.73] and 0.35 (95% CI, 0.13-0.92), respectively. POLE EDMs are prognostic markers associated with excellent outcomes for endometrial carcinoma patients. Further investigation is needed to conclusively determine if treatment is necessary for this group of women. Clin Cancer Res; 22(12); 2865-73. ©2016 AACR. ©2016 American Association for Cancer Research.

Electric Dipole Moments of Light Nuclei From Chiral Effective Field Theory

NASA Astrophysics Data System (ADS)

Higa, R.

2013-08-01

Recent calculations of EDMs of light nuclei in the framework of chiral effective field theory are presented. We argue that they can be written in terms of the leading six low-energy constants encoding CP-violating physics. EDMs of the deuteron, triton, and helion are explicitly given in order to corroborate our claim. An eventual non-zero measurement of these EDMs can be used to disentangle the different sources and strengths of CP-violation.

Hardness and wear analysis of Cu/Al2O3 composite for application in EDM electrode

NASA Astrophysics Data System (ADS)

Hussain, M. Z.; Khan, U.; Jangid, R.; Khan, S.

2018-02-01

Ceramic materials, like Aluminium Oxide (Al2O3), have high mechanical strength, high wear resistance, high temperature resistance and good chemical durability. Powder metallurgy processing is an adaptable method commonly used to fabricate composites because it is a simple method of composite preparation and has high efficiency in dispersing fine ceramic particles. In this research copper and novel material aluminium oxide/copper (Al2O3/Cu) composite has been fabricated for the application of electrode in Electro-Discharge Machine (EDM) using powder metallurgy technique. Al2O3 particles with different weight percentages (0, 1%, 3% and 5%) were reinforced into copper matrix using powder metallurgy technique. The powders were blended and compacted at a load of 100MPa to produce green compacts and sintered at a temperature of 574 °C. The effect of aluminium oxide content on mass density, Rockwell hardness and wear behaviour were investigated. Wear behaviour of the composites was investigated on Die-Sink EDM (Electro-Discharge Machine). It was found that wear rate is highly depending on hardness, mass density and green protective carbonate layer formation at the surface of the composite.

Web Extensible Display Manager

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

Slominski, Ryan; Larrieu, Theodore L.

Jefferson Lab's Web Extensible Display Manager (WEDM) allows staff to access EDM control system screens from a web browser in remote offices and from mobile devices. Native browser technologies are leveraged to avoid installing and managing software on remote clients such as browser plugins, tunnel applications, or an EDM environment. Since standard network ports are used firewall exceptions are minimized. To avoid security concerns from remote users modifying a control system, WEDM exposes read-only access and basic web authentication can be used to further restrict access. Updates of monitored EPICS channels are delivered via a Web Socket using a webmore » gateway. The software translates EDM description files (denoted with the edl suffix) to HTML with Scalable Vector Graphics (SVG) following the EDM's edl file vector drawing rules to create faithful screen renderings. The WEDM server parses edl files and creates the HTML equivalent in real-time allowing existing screens to work without modification. Alternatively, the familiar drag and drop EDM screen creation tool can be used to create optimized screens sized specifically for smart phones and then rendered by WEDM.« less

C P -violation in the two Higgs doublet model: From the LHC to EDMs

NASA Astrophysics Data System (ADS)

Chen, Chien-Yi; Li, Hao-Lin; Ramsey-Musolf, Michael

2018-01-01

We study the prospective sensitivity to C P -violating two Higgs doublet models from the 14 TeV LHC and future electric dipole moment (EDM) experiments. We concentrate on the search for a resonant heavy Higgs that decays to a Z boson and a SM-like Higgs h , leading to the Z (ℓℓ)h (b b ¯ ) final state. The prospective LHC reach is analyzed using the Boosted Decision Tree method. We illustrate the complementarity between the LHC and low energy EDM measurements and study the dependence of the physics reach on the degree of deviation from the alignment limit. In all cases, we find that there exists a large part of parameter space that is sensitive to both EDMs and LHC searches.

Electric dipole moments of actinide atoms and RaO molecule

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

Flambaum, V. V.

We have calculated the atomic electric dipole moments (EDMs) induced in {sup 229}Pa and {sup 225}Ac by their respective nuclear Schiff moments S. The results are d({sup 229}Pa)=-9.5x10{sup -17} [S/(e fm)]e cm=-1.1x10{sup -20}{eta} e cm and d({sup 225}Ac)=-8.6x10{sup -17} [S/(e fm)]e cm=-0.8x10{sup -21}{eta} e cm. EDM of {sup 229}Pa is 3x10{sup 4} times larger than {sup 199}Hg EDM and 40 times larger than {sup 225}Ra EDM. Possible use of actinides in solid state experiments is also discussed. The (T,P)-odd spin-axis interaction in RaO molecule is 500 times larger than in TlF.

Clinical Trials with Oncolytic Measles Virus: Current Status and Future Prospects.

PubMed

Msaouel, Pavlos; Opyrchal, Mateusz; Dispenzieri, Angela; Peng, Kah Whye; Federspiel, Mark J; Russell, Stephen J; Galanis, Evanthia

2018-01-01

Attenuated Edmonston lineage measles virus (MV-Edm) vaccine strains can preferentially infect and lyse a wide variety of cancer cells. Oncolytic MV-Edm derivatives are genetically engineered to express the human carcinoembryonic antigen (MV-CEA virus) or the human sodium iodide symporter (MV-NIS virus) and are currently being tested in clinical trials against ovarian cancer, glioblastoma multiforme, multiple myeloma, mesothelioma, head and neck cancer, breast cancer and malignant peripheral nerve sheath tumors. This review describes the basic and preclinical data that facilitated the clinical translation of MV-Edm strains, and summarizes the clinical results of this oncolytic platform to date. Furthermore, we discuss the latest clinically relevant MV-Edm vector developments and creative strategies for future translational steps. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Simulation investigation of thermal phase transformation and residual stress in single pulse EDM of Ti-6Al-4V

NASA Astrophysics Data System (ADS)

Tang, Jiajing; Yang, Xiaodong

2018-04-01

The thermal phase transformation and residual stress are ineluctable in the electrical discharge machining (EDM) process, and they will greatly affect the working performances of the machined surface. This paper presents a simulation study on the thermal phase transformation and residual stress in single-pulse EDM of Ti-6Al-4V, which is the most popular titanium alloy in fields such as aircraft engine and some other leading industries. A multi-physics model including thermal, hydraulic, metallography and structural mechanics was developed. Based on the proposed model, the thickness and metallographic structure of the recast layer and heat affected layer (HAZ) were investigated. The distribution and characteristics of residual stress around the discharge crater were obtained. The recast layer and HAZ at the center of crater are found to be the thinnest, and their thicknesses gradually increase approaching the periphery of the crater. The recast layer undergoes a complete α‧ (martensitic) transformation, while the HAZ is mainly composed by the α  +  β  +  α‧ three-phase microstructure. Along the depth direction of crater, the Von Mises stress increases first and then decreases, reaching its maximal value near the interface of recast layer and HAZ. In the recast layer, both compressive stress component and tensile stress component are observed. ANOVA results showed that the influence of discharge current on maximal tensile stress is more significant than that of pulse duration, while the pulse duration has more significant influence on average thickness of the recast layer and the depth location of the maximal tensile stress. The works conducted in this study will help to evaluate the quality and integrity of EDMed surface, especially when the non-destructive testing is difficult to achieve.

Detecting a heavy neutrino electric dipole moment at the LHC

NASA Astrophysics Data System (ADS)

Sher, Marc; Stevens, Justin R.

2018-02-01

The milliQan Collaboration has proposed to search for millicharged particles by looking for very weakly ionizing tracks in a detector installed in a cavern near the CMS experiment at the LHC. We note that another form of exotica can also yield weakly ionizing tracks. If a heavy neutrino has an electric dipole moment (EDM), then the milliQan experiment may be sensitive to it as well. In particular, writing the general dimension-5 operator for an EDM with a scale of a TeV and a one-loop factor, one finds a potential EDM as high as a few times 10-17 e-cm, and models exist where it is an order of magnitude higher. Redoing the Bethe calculation of ionization energy loss for an EDM, it is found that the milliQan detector is sensitive to EDMs as small as 10-17 e-cm. Using the production cross-section and analyzing the acceptance of the milliQan detector, we find the expected 95% exclusion and 3σ sensitivity over the range of neutrino masses from 5-1000 GeV for integrated luminosities of 300 and 3000 fb-1 at the LHC.

Sensitivity of fields generated within magnetically shielded volumes to changes in magnetic permeability

NASA Astrophysics Data System (ADS)

Andalib, T.; Martin, J. W.; Bidinosti, C. P.; Mammei, R. R.; Jamieson, B.; Lang, M.; Kikawa, T.

2017-09-01

Future experiments seeking to measure the neutron electric dipole moment (nEDM) require stable and homogeneous magnetic fields. Normally these experiments use a coil internal to a passively magnetically shielded volume to generate the magnetic field. The stability of the magnetic field generated by the coil within the magnetically shielded volume may be influenced by a number of factors. The factor studied here is the dependence of the internally generated field on the magnetic permeability μ of the shield material. We provide measurements of the temperature-dependence of the permeability of the material used in a set of prototype magnetic shields, using experimental parameters nearer to those of nEDM experiments than previously reported in the literature. Our measurements imply a range of 1/μ dμ/dT from 0-2.7%/K. Assuming typical nEDM experiment coil and shield parameters gives μ/B0 dB0/dμ = 0.01, resulting in a temperature dependence of the magnetic field in a typical nEDM experiment of dB0/dT = 0 - 270 pT/K for B0 = 1 μT. The results are useful for estimating the necessary level of temperature control in nEDM experiments.

Impact of Donor Age on Corneal Endothelium-Descemet Membrane Layer Scroll Formation

PubMed Central

Bennett, Adam; Mahmoud, Shahira; Drury, Donna; Cavanagh, H. Dwight; McCulley, James P.; Petroll, W. Matthew; Mootha, V. Vinod

2014-01-01

Objectives To correlate corneal endothelium-Descemet membrane layer (EDM) parameters of scroll tightness with donor age, endothelial cell density, and history of diabetes. Methods EDM scrolls were harvested from 26 corneoscleral buttons using the SCUBA technique by a cornea-fellowship trained ophthalmologist masked to donor age. Two independent outcome parameters were used to characterize the scrolling severity of successfully harvested tissue: scroll width and tendency for EDM scroll formation (referred to as scroll rating on a 1 to 4 scale: incomplete scroll formation to tightly-scrolled). Results Mean donor age was 59 ± 17years (15–69). Mean endothelial cell density of EDM scroll was 2451 ± 626 cells/mm2 mm (range: 1307 – 3195). Using stepwise linear regression, a significant correlation was found between scroll width and donor age (R = 0.497, P < 0.05). Additionally, a significant inverse correlation was found between scroll width and endothelial cell density (R = −0.605, P < 0.05). There was no statistically significant correlation between a donor history of diabetes and the parameters of scrolling tendency. Conclusions Our data suggests that using older donors reduces EDM scroll tightness. PMID:25603436

EDMS Multi-year Validation Plan

DOT National Transportation Integrated Search

2001-06-01

The Emissions and Dispersion Modeling System (EDMS) is the air quality model required for use on airport projects by the Federal Aviation Administration (FAA). This model has continued to be improved and recently has included several important enhanc...

Eddy current standards - Cracks versus notches

NASA Astrophysics Data System (ADS)

Hagemaier, D. J.; Collingwood, M. R.; Nguyen, K. H.

1992-10-01

Eddy current tests aimed at evaluating cracks and electron-discharge machined (EDM) notches in 7075-T6 aluminum specimens are described. A comparison of the shape and amplitude of recordings made from both transverse and longitudinal scans of small EDM notches and fatigue cracks showd almost identical results. The signal amplitude and phase angle increased with an increase of EDM notch and crak size. It is concluded that equivalent eddy current results obtained from similar-size surface cracks and notches in aluminum can be used to establish a desired sensitivity level for inspection.

Ethical decision-making climate in the ICU: theoretical framework and validation of a self-assessment tool.

PubMed

Van den Bulcke, Bo; Piers, Ruth; Jensen, Hanne Irene; Malmgren, Johan; Metaxa, Victoria; Reyners, Anna K; Darmon, Michael; Rusinova, Katerina; Talmor, Daniel; Meert, Anne-Pascale; Cancelliere, Laura; Zubek, Làszló; Maia, Paolo; Michalsen, Andrej; Decruyenaere, Johan; Kompanje, Erwin J O; Azoulay, Elie; Meganck, Reitske; Van de Sompel, Ariëlla; Vansteelandt, Stijn; Vlerick, Peter; Vanheule, Stijn; Benoit, Dominique D

2018-02-23

Literature depicts differences in ethical decision-making (EDM) between countries and intensive care units (ICU). To better conceptualise EDM climate in the ICU and to validate a tool to assess EDM climates. Using a modified Delphi method, we built a theoretical framework and a self-assessment instrument consisting of 35 statements. This Ethical Decision-Making Climate Questionnaire (EDMCQ) was developed to capture three EDM domains in healthcare: interdisciplinary collaboration and communication; leadership by physicians; and ethical environment. This instrument was subsequently validated among clinicians working in 68 adult ICUs in 13 European countries and the USA. Exploratory and confirmatory factor analysis was used to determine the structure of the EDM climate as perceived by clinicians. Measurement invariance was tested to make sure that variables used in the analysis were comparable constructs across different groups. Of 3610 nurses and 1137 physicians providing ICU bedside care, 2275 (63.1%) and 717 (62.9%) participated respectively. Statistical analyses revealed that a shortened 32-item version of the EDMCQ scale provides a factorial valid measurement of seven facets of the extent to which clinicians perceive an EDM climate: self-reflective and empowering leadership by physicians; practice and culture of open interdisciplinary reflection; culture of not avoiding end-of-life decisions; culture of mutual respect within the interdisciplinary team; active involvement of nurses in end-of-life care and decision-making; active decision-making by physicians; and practice and culture of ethical awareness. Measurement invariance of the EDMCQ across occupational groups was shown, reflecting that nurses and physicians interpret the EDMCQ items in a similar manner. The 32-item version of the EDMCQ might enrich the EDM climate measurement, clinicians' behaviour and the performance of healthcare organisations. This instrument offers opportunities to develop tailored ICU team interventions. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effect of multiple autoclave cycles on the surface roughness of HyFlex CM and HyFlex EDM files: an atomic force microscopy study.

PubMed

Yılmaz, K; Uslu, G; Özyürek, T

2018-02-13

To compare the effect of autoclave cycles on the surface topography and roughness of HyFlex CM and HyFlex EDM instruments using atomic force microscopy (AFM) analysis. Eight new files of each brand were subdivided into four subgroups (n = 2/each subgroup). One group was allocated as the control group and not subjected to autoclave sterilization. The other three groups were subjected to different numbers (1, 5, and 10) of autoclave sterilization cycles. After the cycle instruments were subjected to AFM analysis. Roughness average (Ra) and the root mean square (RMS) values were chosen to investigate the surface features of endodontic files. The data was analyzed using one-way ANOVA and post hoc Tamhane tests at 5% significant level. The lowest Ra and RMS values were observed in the HyFlex EDM files that served as the control and in those subjected to a single cycle of autoclave sterilization (P < 0.05). The highest Ra and RMS values were observed in the HyFlex CM and HyFlex EDM files that were subjected to 10 cycles of autoclave sterilization (P < 0.05). The surface roughness values of the HyFlex CM group showed a significant increase after ten autoclave cycles, whereas those of the HyFlex EDM group exhibited a significant change after five autoclave cycles (P < 0.05). Although the initial surface roughness values of the HyFlex EDM files were lower than those of the HyFlex CM files, the surface roughness values of the EDM files showed a statistically significant increase after 5 cycles of autoclave sterilization. In contrast, the surface roughness values of the HyFlex CM files did not increase until 10 cycles of autoclave sterilization. Present study indicated that autoclave sterilization negatively affected the surface roughness of the tested NiTi files.

A new search for the permanent electric dipole moment of 129Xe at FRM-II

NASA Astrophysics Data System (ADS)

Sachdeva, N.; Chupp, T.; Degenkolb, S.; Fierlinger, P.; Kraegloh, E.; Kuchler, F.; Lins, T.; Meinel, J.; Niessen, B.; Stuiber, S.; Terrano, W. A.; Burghoff, M.; Fan, I.; Kilian, W.; Grüneberg, S.; Schnabel, A.; Seifert, F.; Stollfuss, D.; Trahms, L.; Voight, J.; Babcock, E.; Salhi, Z.; Huneau, J.; Singh, J.

2017-01-01

CP-violating sources in beyond-the-standard-model physics, necessary to explain baryon asymmetry, give rise to permanent electric dipole moments (EDMs). Precise EDM measurements of the neutron, electron, paramagnetic and diamagnetic atoms constrain CP-violating parameters. The previous limit for the 129Xe EDM is 6 ×10-27 e . cm (95 % CL). The HeXeEDM experiment at FRM-II (Munich Research Reactor) utilizes an ultralow magnetic field in a high-performance magnetically shielded room and 3He comagnetometer to improve the limit by up to three orders of magnitude. In the experiment, hyperpolarized 3He and 129Xe precession signals are detected with a SQUID magnetometer array in the presence of applied electric and magnetic fields. Recent progress will be presented. This work is supported US Department of Energy Grant No. DE FG02 04 ER41331.

EDM forum supplement overview.

PubMed

Calonge, Ned

2012-07-01

The Agency for Health Research and Quality funded the Electronic Data Methods Forum (EDM Forum) to share the experiences and learnings from 11 research teams funded through three different grant programs, each of which involve the use of electronic clinical data in Comparative Effectiveness Research and Patient-Centered Outcomes Research. This overview is meant to describe the context in which the EDM forum was created and to introduce the set of papers in this supplement to Medical Care that describe the challenges and approaches to the use of electronic clinical data in the three key areas of analytic methods, clinical informatics and data governance. The participants in the EDM Forum are providing innovative approaches to generate information that can support the building of a "learning health care system." The compilation of papers presented in this supplement should serve as a resource to others working to develop the infrastructure for collecting, validating and using electronic data for research.

Second generation measurement of the electric dipole moment of the electron using trapped ThF+ ions

NASA Astrophysics Data System (ADS)

Ng, Kia Boon; Zhou, Yan; Gresh, Daniel; Cairncross, William; Grau, Matthew; Ni, Yiqi; Ye, Jun; Cornell, Eric

2016-05-01

ThF+ has been chosen as the candidate for a second generation measurement of the electric dipole moment of the electron (eEDM). Compared to the current HfF+ eEDM experiment, ThF+ has several advantages: (i) the eEDM-sensitive state (3Δ1) is the ground state, which facilitates a long coherence time; (ii) its effective electric field (38 GV/cm) is 50% larger than that of HfF+, which promises a direct increase of the eEDM sensitivity; and (iii) the ionization energy of neutral ThF is lower than its dissociation energy, which introduces greater flexibility in rotational state-selective photoionization via core-nonpenetrating Rydberg states. Here, we present progress of our experimental setup, preliminary spectroscopic data of multi-photon ionization, and discussions of new features in ion trapping, state preparation and population readout.

Correlation between Temperature-dependent Fatigue Resistance and Differential Scanning Calorimetry Analysis for 2 Contemporary Rotary Instruments.

PubMed

Arias, Ana; Macorra, José C; Govindjee, Sanjay; Peters, Ove A

2018-04-01

The aim of this study was to assess differences in cyclic fatigue (CF) life of contemporary heat-treated nickel-titanium rotary instruments at room and body temperatures and to document corresponding phase transformations. Forty Hyflex EDM (H-EDM) files (Coltene, Cuyahoga Falls, OH [#25/.08, manufactured by electrical discharge machining]) and 40 TRUShape (TS) files (Dentsply Tulsa Dental Specialties, Tulsa, OK [#25/.06v, manufactured by grinding and shape setting]) were divided into 2 groups (n = 20) for CF resistance tests in a water bath either at room (22°C ± 0.5°C) or body temperature (37°C ± 0.5°C). Instruments were rotated in a simulated canal (angle = 60°, radius = 3 mm, and center of the curvature 5 mm from the tip) until fracture occurred. The motor was controlled by an electric circuit that was interrupted after instrument fracture. The mean half-life and beta and eta Weibull parameters were determined and compared. Two instruments of each brand were subjected to differential scanning calorimetry (DSC). While TS instruments lasted significantly longer at room temperature (mean life = 234.7 seconds; 95% confidence interval [CI], 209-263.6) than at body temperature (mean life = 83.2 seconds; 95% CI, 76-91.1), temperature did not affect H-EDM behavior (room temperature mean life = 725.4 seconds; 95% CI, 658.8-798.8 and body temperature mean life = 717.9 seconds; 95% CI, 636.8-809.3). H-EDM instruments significantly outlasted TS instruments at both temperatures. At body temperature, TS was predominantly austenitic, whereas H-EDM was martensitic or in R-phase. TS was in a mixed austenitic/martensitic phase at 22°C, whereas H-EDM was in the same state as at 37°C. H-EDM had a longer fatigue life than TS, which showed a marked decrease in fatigue life at body temperature; neither the life span nor the state of the microstructure in the DSC differed for H-EDM between room or body temperature. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Comparative Study of Vibration Condition Indicators for Detecting Cracks in Spur Gears

NASA Technical Reports Server (NTRS)

Nanadic, Nenad; Ardis, Paul; Hood, Adrian; Thurston, Michael; Ghoshal, Anindya; Lewicki, David

2013-01-01

This paper reports the results of an empirical study on the tooth breakage failure mode in spur gears. Of four dominant gear failure modes (breakage, wear, pitting, and scoring), tooth breakage is the most precipitous and often leads to catastrophic failures. The cracks were initiated using a fatigue tester and a custom-designed single-tooth bending fixture to simulate over-load conditions, instead of traditional notching using wire electrical discharge machining (EDM). The cracks were then propagated on a dynamometer. The ground truth of damage level during crack propagation was monitored with crack-propagation sensors. Ten crack propagations have been performed to compare the existing condition indicators (CIs) with respect to their: ability to detect a crack, ability to assess the damage, and sensitivity to sensor placement. Of more than thirty computed CIs, this paper compares five commonly used: raw RMS, FM0, NA4, raw kurtosis, and NP4. The performance of combined CIs was also investigated, using linear, logistic, and boosted regression trees based feature fusion.

Effect of electric discharge machining on the fatigue life of Inconel 718

NASA Technical Reports Server (NTRS)

Jeelani, S.; Collins, M. R.

1988-01-01

The effect of electric discharge machining on the fatigue life of Inconel 718 alloy at room temperature was investigated. Data were generated in the uniaxial tension fatigue mode at ambient temperature using flat 3.175 mm thick specimens. The specimens were machined on a wire-cut electric discharge machine at cutting speeds ranging from 0.5 to 2 mm per minute. The specimens were fatigued at a selected stress, and the resulting fatigue lives compared with that of the virgin material. The surfaces of the fatigued specimens were examined under optical and scanning electron microscopes, and the roughness of the surfaces was measured using a standard profilometer. From the results of the investigation, it was concluded that the fatigue life of the specimens machined using EDM decreased slightly as compared with that of the virgin material, but remained unchanged as the cutting speed was changed. The results are explained using data produced employing microhardness measurements, profilometry, and optical and scanning microscopy.

An Update on 3He Correlation Function Research for the SNS nEDM collaboration

NASA Astrophysics Data System (ADS)

Reid, Austin; Golub, Robert; Dipert, Robert

2016-09-01

In the 65 years since Ramsey's null result for the neutron's permanent electric dipole moment (nEDM), techniques have become increasingly sensitive, establishing the present upper limit of 3 ×10-26 e .cm . This value was limited by an unexpected source of error: a freqency shift with linear dependence on the electric field colloquially called a false EDM. The next generation nEDM sensing apparatus being developed for the Spallation Neutron Source at Oak Ridge National Laboratory uses a 3He comagenetometer in a pure helium-II bath. The false EDM in 3He may be related to the 3He's position autocorrelation function, which in turn is accessible by a detailed study of T1 decay in hyperpolarized 3He. Existing measurements of this system were limited by temperature, noise, and 3He concentration. Dramatic improvements have been made on all three fronts by improving the thermal connection between the measurment cell and the dilution refrigerator, by adding additional shielding and a SQUID package, and by developing a MEOP 3He polarization system. Data collection is underway. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Award Number DE-FG02-97ER41042.

Relativistic Normal Coupled-Cluster Theory for Accurate Determination of Electric Dipole Moments of Atoms: First Application to the 199Hg Atom

NASA Astrophysics Data System (ADS)

Sahoo, B. K.; Das, B. P.

2018-05-01

Recent relativistic coupled-cluster (RCC) calculations of electric dipole moments (EDMs) of diamagnetic atoms due to parity and time-reversal violating (P ,T -odd) interactions, which are essential ingredients for probing new physics beyond the standard model of particle interactions, differ substantially from the previous theoretical results. It is therefore necessary to perform an independent test of the validity of these results. In view of this, the normal coupled-cluster method has been extended to the relativistic regime [relativistic normal coupled-cluster (RNCC) method] to calculate the EDMs of atoms by simultaneously incorporating the electrostatic and P ,T -odd interactions in order to overcome the shortcomings of the ordinary RCC method. This new relativistic method has been applied to 199Hg, which currently has a lower EDM limit than that of any other system. The results of our RNCC and self-consistent RCC calculations of the EDM of this atom are found to be close. The discrepancies between these two results on the one hand and those of previous calculations on the other are elucidated. Furthermore, the electric dipole polarizability of this atom, which has computational similarities with the EDM, is evaluated and it is in very good agreement with its measured value.

Relativistic Normal Coupled-Cluster Theory for Accurate Determination of Electric Dipole Moments of Atoms: First Application to the ^{199}Hg Atom.

PubMed

Sahoo, B K; Das, B P

2018-05-18

Recent relativistic coupled-cluster (RCC) calculations of electric dipole moments (EDMs) of diamagnetic atoms due to parity and time-reversal violating (P,T-odd) interactions, which are essential ingredients for probing new physics beyond the standard model of particle interactions, differ substantially from the previous theoretical results. It is therefore necessary to perform an independent test of the validity of these results. In view of this, the normal coupled-cluster method has been extended to the relativistic regime [relativistic normal coupled-cluster (RNCC) method] to calculate the EDMs of atoms by simultaneously incorporating the electrostatic and P,T-odd interactions in order to overcome the shortcomings of the ordinary RCC method. This new relativistic method has been applied to ^{199}Hg, which currently has a lower EDM limit than that of any other system. The results of our RNCC and self-consistent RCC calculations of the EDM of this atom are found to be close. The discrepancies between these two results on the one hand and those of previous calculations on the other are elucidated. Furthermore, the electric dipole polarizability of this atom, which has computational similarities with the EDM, is evaluated and it is in very good agreement with its measured value.

Electric dipole moments in natural supersymmetry

NASA Astrophysics Data System (ADS)

Nakai, Yuichiro; Reece, Matthew

2017-08-01

We discuss electric dipole moments (EDMs) in the framework of CP-violating natural supersymmetry (SUSY). Recent experimental results have significantly tightened constraints on the EDMs of electrons and of mercury, and substantial further progress is expected in the near future. We assess how these results constrain the parameter space of natural SUSY. In addition to our discussion of SUSY, we provide a set of general formulas for two-loop fermion EDMs, which can be applied to a wide range of models of new physics. In the SUSY context, the two-loop effects of stops and charginos respectively constrain the phases of A t μ and M 2 μ to be small in the natural part of parameter space. If the Higgs mass is lifted to 125 GeV by a new tree-level superpotential interaction and soft term with CP-violating phases, significant EDMs can arise from the two-loop effects of W bosons and tops. We compare the bounds arising from EDMs to those from other probes of new physics including colliders, b → sγ, and dark matter searches. Importantly, improvements in reach not only constrain higher masses, but require the phases to be significantly smaller in the natural parameter space at low mass. The required smallness of phases sharpens the CP problem of natural SUSY model building.

Investigation of a 129Xe magnetometer for the Neutron Electric Dipole Moment Experiment at TRIUMF

NASA Astrophysics Data System (ADS)

Lang, Michael; Nedm At Triumf Collaboration

2016-03-01

A non-zero neutron electric dipole moment (nEDM) would signify a previously unknown source of CP (or T) violation. New sources of CP violation are believed to be required to explain the baryon asymmetry of the universe. Employing a newly developed high-density UCN source, an experiment at TRIUMF aims to measure the nEDM to the level of 10-27 e . cm in its initial phase. Precession frequency differences for UCN stored in a bottle subject to parallel and anti-parallel E and B fields signify a permanent nEDM. Magnetic field instability and inhomogeneity, as well as field changes resulting from leakage currents (correlated with E fields) are the dominant systematic effects in nEDM measurements. To address this, passive and active magnetic shielding are in development along with a dual species (129Xe and 199Hg) atomic comagnetometer. Simultaneously introducing both atomic species into the UCN cell, the comagnetometer can mitigate false EDMs. 199Hg precession will be detected by Faraday rotation spectroscopy, and 129Xe precession will measured via two-photon excitation and emission. The present comagnetometer progress will be discussed, with focus on polarized 129Xe production and delivery. Work supported by the Natural Sciences and Engineering Research Council of Canada.

Evidence of the Primary Afferent Tracts Undergoing Neurodegeneration in Horses With Equine Degenerative Myeloencephalopathy Based on Calretinin Immunohistochemical Localization.

PubMed

Finno, C J; Valberg, S J; Shivers, J; D'Almeida, E; Armién, A G

2016-01-01

Equine degenerative myeloencephalopathy (EDM) is characterized by a symmetric general proprioceptive ataxia in young horses, and is likely underdiagnosed for 2 reasons: first, clinical signs overlap those of cervical vertebral compressive myelopathy; second, histologic lesions--including axonal spheroids in specific tracts of the somatosensory and motor systems--may be subtle. The purpose of this study was (1) to utilize immunohistochemical (IHC) markers to trace axons in the spinocuneocerebellar, dorsal column-medial lemniscal, and dorsospinocerebellar tracts in healthy horses and (2) to determine the IHC staining characteristics of the neurons and degenerated axons along the somatosensory tracts in EDM-affected horses. Examination of brain, spinal cord, and nerves was performed on 2 age-matched control horses, 3 EDM-affected horses, and 2 age-matched disease-control horses via IHC for calbindin, vesicular glutamate transporter 2, parvalbumin, calretinin, glutamic acid decarboxylase, and glial fibrillary acidic protein. Primary afferent axons of the spinocuneocerebellar, dorsal column-medial lemniscal, and dorsospinocerebellar tracts were successfully traced with calretinin. Calretinin-positive cell bodies were identified in a subset of neurons in the dorsal root ganglia, suggesting that calretinin IHC could be used to trace axonal projections from these cell bodies. Calretinin-immunoreactive spheroids were present in EDM-affected horses within the nuclei cuneatus medialis, cuneatus lateralis, and thoracicus. Neurons within those nuclei were calretinin negative. Cell bodies of degenerated axons in EDM-affected horses are likely located in the dorsal root ganglia. These findings support the role of sensory axonal degeneration in the pathogenesis of EDM and provide a method to highlight tracts with axonal spheroids to aid in the diagnosis of this neurodegenerative disease. © The Author(s) 2015.

Evidence of the Primary Afferent Tracts Undergoing Neurodegeneration in Horses With Equine Degenerative Myeloencephalopathy Based on Calretinin Immunohistochemical Localization

PubMed Central

Finno, C. J.; Valberg, S. J.; Shivers, J.; D’Almeida, E.; Armién, A. G.

2016-01-01

Equine degenerative myeloencephalopathy (EDM) is characterized by a symmetric general proprioceptive ataxia in young horses, and is likely underdiagnosed for 2 reasons: first, clinical signs overlap those of cervical vertebral compressive myelopathy; second, histologic lesions—including axonal spheroids in specific tracts of the somatosensory and motor systems—may be subtle. The purpose of this study was (1) to utilize immunohistochemical (IHC) markers to trace axons in the spinocuneocerebellar, dorsal column–medial lemniscal, and dorsospinocerebellar tracts in healthy horses and (2) to determine the IHC staining characteristics of the neurons and degenerated axons along the somatosensory tracts in EDM-affected horses. Examination of brain, spinal cord, and nerves was performed on 2 age-matched control horses, 3 EDM-affected horses, and 2 age-matched disease-control horses via IHC for calbindin, vesicular glutamate transporter 2, parvalbumin, calretinin, glutamic acid decarboxylase, and glial fibrillary acidic protein. Primary afferent axons of the spinocuneocerebellar, dorsal column–medial lemniscal, and dorsospinocerebellar tracts were successfully traced with calretinin. Calretinin-positive cell bodies were identified in a subset of neurons in the dorsal root ganglia, suggesting that calretinin IHC could be used to trace axonal projections from these cell bodies. Calretinin-immunoreactive spheroids were present in EDM-affected horses within the nuclei cuneatus medialis, cuneatus lateralis, and thoracicus. Neurons within those nuclei were calretinin negative. Cell bodies of degenerated axons in EDM-affected horses are likely located in the dorsal root ganglia. These findings support the role of sensory axonal degeneration in the pathogenesis of EDM and provide a method to highlight tracts with axonal spheroids to aid in the diagnosis of this neurodegenerative disease. PMID:26253880

Lattice calculation of electric dipole moments and form factors of the nucleon

NASA Astrophysics Data System (ADS)

Abramczyk, M.; Aoki, S.; Blum, T.; Izubuchi, T.; Ohki, H.; Syritsyn, S.

2017-07-01

We analyze commonly used expressions for computing the nucleon electric dipole form factors (EDFF) F3 and moments (EDM) on a lattice and find that they lead to spurious contributions from the Pauli form factor F2 due to inadequate definition of these form factors when parity mixing of lattice nucleon fields is involved. Using chirally symmetric domain wall fermions, we calculate the proton and the neutron EDFF induced by the C P -violating quark chromo-EDM interaction using the corrected expression. In addition, we calculate the electric dipole moment of the neutron using a background electric field that respects time translation invariance and boundary conditions, and we find that it decidedly agrees with the new formula but not the old formula for F3. Finally, we analyze some selected lattice results for the nucleon EDM and observe that after the correction is applied, they either agree with zero or are substantially reduced in magnitude, thus reconciling their difference from phenomenological estimates of the nucleon EDM.

Search for an Electric Dipole Moment (EDM) of 199Hg

NASA Astrophysics Data System (ADS)

Heckel, Blayne

2017-04-01

The observation of a non-zero EDM of an atom or elementary particle, at current levels of experimental sensitivity, would imply CP violation beyond the CKM matrix of the standard model of particle physics. Additional sources of CP violation have been proposed to help explain the excess of matter over anti-matter in our universe and the magnitude of ΘQCD, the strength of CP violation in the strong interaction, remains unknown. We have recently completed a set of measurements on the EDM of 199Hg, sensitive to both new sources of CP violation and ΘQCD. The experiment compares the phase accumulated by precessing Hg spins in vapor cells with electric fields parallel and anti-parallel to a common magnetic field. Our new result represents a factor of 5 improvement over previous results. A description of the EDM experiment, data, systematic error considerations will be presented. This work was supported by NSF Grant No. 1306743 and by the DOE Office of Nuclear Physics under Award No. DE-FG02-97ER41020.

Improvements to the YbF electron electric dipole moment experiment

NASA Astrophysics Data System (ADS)

Sauer, B. E.; Rabey, I. M.; Devlin, J. A.; Tarbutt, M. R.; Ho, C. J.; Hinds, E. A.

2017-04-01

The standard model of particle physics predicts that the permanent electric dipole moment (EDM) of the electron is very nearly zero. Many extensions to the standard model predict an electron EDM just below current experimental limits. We are currently working to improve the sensitivity of the Imperial College YbF experiment. We have implemented combined laser-radiofrequency pumping techniques which both increase the number of molecules which participate in the EDM experiment and also increase the probability of detection. Combined, these techniques give nearly two orders of magnitude increase in the experimental sensitivity. At this enhanced sensitivity magnetic effects which were negligible become important. We have developed a new way to construct the electrodes for electric field plates which minimizes the effect of magnetic Johnson noise. The new YbF experiment is expected to comparable in sensitivity to the most sensitive measurements of the electron EDM to date. We will also discuss laser cooling techniques which promise an even larger increase in sensitivity.

Emissions and dispersion modeling system (EDMS). Its development and application at airports and airbases

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

Moss, M.T.; Segal, H.M.

1994-06-01

A new complex source microcomputer model has been developed for use at civil airports and Air Force bases. This paper describes both the key features of this model and its application in evaluating the air quality impact of new construction projects at three airports: one in the United States and two in Canada. The single EDMS model replaces the numerous models previously required to assess the air quality impact of pollution sources at airports. EDMS also employs a commercial data base to reduce the time and manpower required to accurately assess and document the air quality impact of airfield operations.more » On July 20, 1993, the U.S. Environmental Protection Agency (EPA) issued the final rule (Federal Register, 7/20/93, page 38816) to add new models to the Guideline on Air Quality Models. At that time EDMS was incorporated into the Guideline as an Appendix A model. 12 refs., 4 figs., 1 tab.« less

Fundamental dynamics: Past, present and the future — like CP violation and EDMs

NASA Astrophysics Data System (ADS)

Bigi, Ikaros I.

2015-04-01

Working with Kolya Uraltsev was a real 'marvel' for me in general, but in particular about CP and T violation, QCD and its impact on transitions in heavy flavor hadrons and EDMs. The goal was — and still is — to define fundamental parameters for dynamics, how to measure them and compare SM forces with New Dynamics using the best tools including our brains. The correlations of them with accurate data were crucial for Kolya. Here is a review of CP asymmetries in B, D and τ decays, the impact of perturbative and non-perturbative QCD, about EDMs till 2013 — and for the future.

Symplectic orbit and spin tracking code for all-electric storage rings

NASA Astrophysics Data System (ADS)

Talman, Richard M.; Talman, John D.

2015-07-01

Proposed methods for measuring the electric dipole moment (EDM) of the proton use an intense, polarized proton beam stored in an all-electric storage ring "trap." At the "magic" kinetic energy of 232.792 MeV, proton spins are "frozen," for example always parallel to the instantaneous particle momentum. Energy deviation from the magic value causes in-plane precession of the spin relative to the momentum. Any nonzero EDM value will cause out-of-plane precession—measuring this precession is the basis for the EDM determination. A proposed implementation of this measurement shows that a proton EDM value of 10-29e -cm or greater will produce a statistically significant, measurable precession after multiply repeated runs, assuming small beam depolarization during 1000 s runs, with high enough precision to test models of the early universe developed to account for the present day particle/antiparticle population imbalance. This paper describes an accelerator simulation code, eteapot, a new component of the Unified Accelerator Libraries (ual), to be used for long term tracking of particle orbits and spins in electric bend accelerators, in order to simulate EDM storage ring experiments. Though qualitatively much like magnetic rings, the nonconstant particle velocity in electric rings gives them significantly different properties, especially in weak focusing rings. Like the earlier code teapot (for magnetic ring simulation) this code performs exact tracking in an idealized (approximate) lattice rather than the more conventional approach, which is approximate tracking in a more nearly exact lattice. The Bargmann-Michel-Telegdi (BMT) equation describing the evolution of spin vectors through idealized bend elements is also solved exactly—original to this paper. Furthermore the idealization permits the code to be exactly symplectic (with no artificial "symplectification"). Any residual spurious damping or antidamping is sufficiently small to permit reliable tracking for the long times, such as the 1000 s assumed in estimating the achievable EDM precision. This paper documents in detail the theoretical formulation implemented in eteapot. An accompanying paper describes the practical application of the eteapot code in the Universal Accelerator Libraries (ual) environment to "resurrect," or reverse engineer, the "AGS-analog" all-electric ring built at Brookhaven National Laboratory in 1954. Of the (very few) all-electric rings ever commissioned, the AGS-analog ring is the only relativistic one and is the closest to what is needed for measuring proton (or, even more so, electron) EDM's. The companion paper also describes preliminary lattice studies for the planned proton EDM storage rings as well as testing the code for long time orbit and spin tracking.

Edme Mariotte and Newton's Cradle

ERIC Educational Resources Information Center

Cross, Rod

2012-01-01

The first recorded experiments describing the phenomena made popular by Newton's cradle appear to be those conducted by Edme Mariotte around 1670. He was quoted in Newton's "Principia," along with Wren, Wallis, and Huygens, as having conducted pioneering experiments on the collisions of pendulum balls. Each of these authors concluded that momentum…

A comparison of neural network architectures for the prediction of MRR in EDM

NASA Astrophysics Data System (ADS)

Jena, A. R.; Das, Raja

2017-11-01

The aim of the research work is to predict the material removal rate of a work-piece in electrical discharge machining (EDM). Here, an effort has been made to predict the material removal rate through back-propagation neural network (BPN) and radial basis function neural network (RBFN) for a work-piece of AISI D2 steel. The input parameters for the architecture are discharge-current (Ip), pulse-duration (Ton), and duty-cycle (τ) taken for consideration to obtained the output for material removal rate of the work-piece. In the architecture, it has been observed that radial basis function neural network is comparatively faster than back-propagation neural network but logically back-propagation neural network results more real value. Therefore BPN may consider as a better process in this architecture for consistent prediction to save time and money for conducting experiments.

Catalytic aided electrical discharge machining of polycrystalline diamond - parameter analysis of finishing condition

NASA Astrophysics Data System (ADS)

Haikal Ahmad, M. A.; Zulafif Rahim, M.; Fauzi, M. F. Mohd; Abdullah, Aslam; Omar, Z.; Ding, Songlin; Ismail, A. E.; Rasidi Ibrahim, M.

2018-01-01

Polycrystalline diamond (PCD) is regarded as among the hardest material in the world. Electrical Discharge Machining (EDM) typically used to machine this material because of its non-contact process nature. This investigation was purposely done to compare the EDM performances of PCD when using normal electrode of copper (Cu) and newly proposed graphitization catalyst electrode of copper nickel (CuNi). Two level full factorial design of experiment with 4 center points technique was used to study the influence of main and interaction effects of the machining parameter namely; pulse-on, pulse-off, sparking current, and electrode materials (categorical factor). The paper shows interesting discovery in which the newly proposed electrode presented positive impact to the machining performance. With the same machining parameters of finishing, CuNi delivered more than 100% better in Ra and MRR than ordinary Cu electrode.

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.

Improved limit on the Ra 225 electric dipole moment

DOE PAGES

Bishof, Michael; Parker, Richard H.; Bailey, Kevin G.; ...

2016-08-03

In this study, octupole-deformed nuclei, such as that of 225Ra, are expected to amplify observable atomic electric dipole moments (EDMs) that arise from time-reversal and parity-violating interactions in the nuclear medium. In 2015 we reported the first “proof-of-principle” measurement of the 225Ra atomic EDM.

Tools for Educational Data Mining: A Review

ERIC Educational Resources Information Center

Slater, Stefan; Joksimovic, Srecko; Kovanovic, Vitomir; Baker, Ryan S.; Gasevic, Dragan

2017-01-01

In recent years, a wide array of tools have emerged for the purposes of conducting educational data mining (EDM) and/or learning analytics (LA) research. In this article, we hope to highlight some of the most widely used, most accessible, and most powerful tools available for the researcher interested in conducting EDM/LA research. We will…

Improved limit on the Ra 225 electric dipole moment

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

Bishof, Michael; Parker, Richard H.; Bailey, Kevin G.

In this study, octupole-deformed nuclei, such as that of 225Ra, are expected to amplify observable atomic electric dipole moments (EDMs) that arise from time-reversal and parity-violating interactions in the nuclear medium. In 2015 we reported the first “proof-of-principle” measurement of the 225Ra atomic EDM.

Improved Limits on Axionlike-Particle-Mediated P, T-Violating Interactions between Electrons and Nucleons from Electric Dipole Moments of Atoms and Molecules.

PubMed

Stadnik, Y V; Dzuba, V A; Flambaum, V V

2018-01-05

In the presence of P, T-violating interactions, the exchange of axionlike particles between electrons and nucleons in atoms and molecules induces electric dipole moments (EDMs) of atoms and molecules. We perform calculations of such axion-exchange-induced atomic EDMs using the relativistic Hartree-Fock-Dirac method including electron core polarization corrections. We present analytical estimates to explain the dependence of these induced atomic EDMs on the axion mass and atomic parameters. From the experimental bounds on the EDMs of atoms and molecules, including ^{133}Cs, ^{205}Tl, ^{129}Xe, ^{199}Hg, ^{171}Yb^{19}F, ^{180}Hf^{19}F^{+}, and ^{232}Th^{16}O, we constrain the P, T-violating scalar-pseudoscalar nucleon-electron and electron-electron interactions mediated by a generic axionlike particle of arbitrary mass. Our limits improve on existing laboratory bounds from other experiments by many orders of magnitude for m_{a}≳10^{-2}  eV. We also place constraints on CP violation in certain types of relaxion models.

Optimization of machining parameters in dry EDM of EN31 steel

NASA Astrophysics Data System (ADS)

Brar, G. S.

2018-03-01

Dry electric discharge machining (Dry EDM) is one of the novel EDM technology in which gases namely helium, argon, oxygen, nitrogen etc. are used as a dielectric medium at high pressure instead of oil based liquid dielectric. The present study investigates dry electric discharge machining (with rotary tool) of EN-31 steel to achieve lower tool wear rate (TWR) and better surface roughness (Ra) by performing a set of exploratory experiments with oxygen gas as dielectric. The effect of polarity, discharge current, gas flow pressure, pulse-on time, R.P.M. and gap voltage on the MRR, TWR and surface roughness (Ra) in dry EDM was studied with copper as rotary tool. The significant factors affecting MRR are discharge current and pulse on time. The significant factors affecting TWR are gas flow pressure, pulse on time and R.P.M. TWR was found close to zero in most of the experiments. The significant factors affecting Ra are pulse on time, gas flow pressure and R.P.M. It was found that polarity has nearly zero effect on all the three output variables.

Lattice calculation of electric dipole moments and form factors of the nucleon

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

Abramczyk, M.; Aoki, S.; Blum, T.

In this paper, we analyze commonly used expressions for computing the nucleon electric dipole form factors (EDFF)more » $$F_3$$ and moments (EDM) on a lattice and find that they lead to spurious contributions from the Pauli form factor $$F_2$$ due to inadequate definition of these form factors when parity mixing of lattice nucleon fields is involved. Using chirally symmetric domain wall fermions, we calculate the proton and the neutron EDFF induced by the CP-violating quark chromo-EDM interaction using the corrected expression. In addition, we calculate the electric dipole moment of the neutron using a background electric field that respects time translation invariance and boundary conditions, and we find that it decidedly agrees with the new formula but not the old formula for $$F_3$$. In conclusion, we analyze some selected lattice results for the nucleon EDM and observe that after the correction is applied, they either agree with zero or are substantially reduced in magnitude, thus reconciling their difference from phenomenological estimates of the nucleon EDM.« less

Progress in Developing Transfer Functions for Surface Scanning Eddy Current Inspections

NASA Astrophysics Data System (ADS)

Shearer, J.; Heebl, J.; Brausch, J.; Lindgren, E.

2009-03-01

As US Air Force (USAF) aircraft continue to age, additional inspections are required for structural components. The validation of new inspections typically requires a capability demonstration of the method using representative structure with representative damage. To minimize the time and cost required to prepare such samples, Electric Discharge machined (EDM) notches are commonly used to represent fatigue cracks in validation studies. However, the sensitivity to damage typically changes as a function of damage type. This requires a mathematical relationship to be developed between the responses from the two different flaw types to enable the use of EDM notched samples to validate new inspections. This paper reviews progress to develop transfer functions for surface scanning eddy current inspections of aluminum and titanium alloys found in structural aircraft components. Multiple samples with well characterized grown fatigue cracks and master gages with EDM notches, both with a range of flaw sizes, were used to collect flaw signals with USAF field inspection equipment. Analysis of this empirical data was used to develop a transfer function between the response from the EDM notches and grown fatigue cracks.

Neutron Electric Dipole Moment and Tensor Charges from Lattice QCD

DOE PAGES

Bhattacharya, Tanmoy; Cirigliano, Vincenzo; Gupta, Rajan; ...

2015-11-17

In this paper, we present lattice QCD results on the neutron tensor charges including, for the first time, a simultaneous extrapolation in the lattice spacing, volume, and light quark masses to the physical point in the continuum limit. We find that the “disconnected” contribution is smaller than the statistical error in the “connected” contribution. Our estimates in the modified minimal subtraction scheme at 2 GeV, including all systematics, are g d-u T=1.020(76), g d T=0.774(66), g u T=-0.233(28), and g s T=0.008(9). The flavor diagonal charges determine the size of the neutron electric dipole moment (EDM) induced by quark EDMsmore » that are generated in many new scenarios of CP violation beyond the standard model. Finally, we use our results to derive model-independent bounds on the EDMs of light quarks and update the EDM phenomenology in split supersymmetry with gaugino mass unification, finding a stringent upper bound of d n<4×10 -28 e cm for the neutron EDM in this scenario.« less

Lattice calculation of electric dipole moments and form factors of the nucleon

DOE PAGES

Abramczyk, M.; Aoki, S.; Blum, T.; ...

2017-07-10

In this paper, we analyze commonly used expressions for computing the nucleon electric dipole form factors (EDFF)more » $$F_3$$ and moments (EDM) on a lattice and find that they lead to spurious contributions from the Pauli form factor $$F_2$$ due to inadequate definition of these form factors when parity mixing of lattice nucleon fields is involved. Using chirally symmetric domain wall fermions, we calculate the proton and the neutron EDFF induced by the CP-violating quark chromo-EDM interaction using the corrected expression. In addition, we calculate the electric dipole moment of the neutron using a background electric field that respects time translation invariance and boundary conditions, and we find that it decidedly agrees with the new formula but not the old formula for $$F_3$$. In conclusion, we analyze some selected lattice results for the nucleon EDM and observe that after the correction is applied, they either agree with zero or are substantially reduced in magnitude, thus reconciling their difference from phenomenological estimates of the nucleon EDM.« less

Stimulated Raman adiabatic passage preparation of a coherent superposition of ThO H3Δ1 states for an improved electron electric-dipole-moment measurement

NASA Astrophysics Data System (ADS)

Panda, C. D.; O'Leary, B. R.; West, A. D.; Baron, J.; Hess, P. W.; Hoffman, C.; Kirilov, E.; Overstreet, C. B.; West, E. P.; DeMille, D.; Doyle, J. M.; Gabrielse, G.

2016-05-01

Experimental searches for the electron electric-dipole moment (EDM) probe new physics beyond the standard model. The current best EDM limit was set by the ACME Collaboration [Science 343, 269 (2014), 10.1126/science.1248213], constraining time-reversal symmetry (T ) violating physics at the TeV energy scale. ACME used optical pumping to prepare a coherent superposition of ThO H3Δ1 states that have aligned electron spins. Spin precession due to the molecule's internal electric field was measured to extract the EDM. We report here on an improved method for preparing this spin-aligned state of the electron by using stimulated Raman adiabatic passage (STIRAP). We demonstrate a transfer efficiency of 75 %±5 % , representing a significant gain in signal for a next-generation EDM experiment. We discuss the particularities of implementing STIRAP in systems such as ours, where molecular ensembles with large phase-space distributions are transferred via weak molecular transitions with limited laser power and limited optical access.

Antecedents of ethical decision-making: intercollegiate sporting environments as clinical education and practice settings.

PubMed

Caswell, Shane V; Ambegaonkar, Jatin P; Caswell, Amanda M; Gould, Trenton E

2009-01-01

Unique among allied health care professions, athletic training is predominately practiced amid competitive intercollegiate sports. Competitive sporting environments have been suggested to adversely impact morality, ethical decision-making (EDM), and behavior. The purposes of this study were to (1) investigate the effect of institutional National Collegiate Athletic Association (NCAA) participation level on preferred ethical ideologies and EDM, (2) determine the relationship between professional status (athletic training student [ATS] or certified athletic trainer [ATC]) and ethical ideology preferences and EDM, and (3) examine whether preferred ethical ideology is related to differences in EDM. A nationally representative sample of 610 ATSs and ATCs from 30 athletic training education programs, stratified by NCAA division level, participated in the study. All participants completed a demographic survey, the Ethics Position Questionnaire, and the Dilemmas in Athletic Training Questionnaire. No significant relationships were noted between NCAA participation level and respondents' ethical ideology preferences. However, ATSs and ATCs demonstrated significant preferences for specific ethical ideologies, with students adopting the subjectivist ideology more than expected and the exceptionist ideology less than expected and ATCs adopting the exceptionist ideology more than expected and the situationist ideology less than expected. In contrast to some previous research, our results suggest that competitive sporting environments do not affect ATSs' and ATCs' ethical ideology and EDM abilities at the collegiate level. These findings serve as a baseline for future research examining the ethical ideologies and ethical decision-making levels of athletic training practitioners and other allied health professionals across clinical settings.

The Electronic Data Methods (EDM) forum for comparative effectiveness research (CER).

PubMed

Holve, Erin; Segal, Courtney; Lopez, Marianne Hamilton; Rein, Alison; Johnson, Beth H

2012-07-01

AcademyHealth convened the Electronic Data Methods (EDM) Forum to collect, synthesize, and share lessons from eleven projects that are building infrastructure and using electronic clinical data for comparative effectiveness research (CER) and patient-centered outcomes research (PCOR). This paper provides a brief review of participating projects and provides a framework of common challenges. EDM Forum staff conducted a text review of relevant grant programs' funding opportunity announcements; projects' research plans; and available information on projects' websites. Additional information was obtained from presentations provided by each project; phone calls with project principal investigators, affiliated partners, and staff from the Agency for Healthcare Research and Quality (AHRQ); and six site visits. Projects participating in the EDM Forum are building infrastructure and developing innovative strategies to address a set of methodological, and data and informatics challenges, here identified in a common framework. The eleven networks represent more than 20 states and include a range of partnership models. Projects vary substantially in size, from 11,000 to more than 7.5 million individuals. Nearly all of the AHRQ priority populations and conditions are addressed. In partnership with the projects, the EDM Forum is focused on identifying and sharing lessons learned to advance the national dialogue on the use of electronic clinical data to conduct CER and PCOR. These efforts have the shared goal of addressing challenges in traditional research studies and data sources, and aim to build infrastructure and generate evidence to support a learning health care system that can improve patient outcomes.

Contribution of relativistic quantum chemistry to electron’s electric dipole moment for CP violation

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

Abe, M., E-mail: minoria@tmu.ac.jp; Gopakumar, G., E-mail: gopakumargeetha@gmail.com; Hada, M., E-mail: hada@tmu.ac.jp

The search for the electric dipole moment of the electron (eEDM) is important because it is a probe of Charge Conjugation-Parity (CP) violation. It can also shed light on new physics beyond the standard model. It is not possible to measure the eEDM directly. However, the interaction energy involving the effective electric field (E{sub eff}) acting on an electron in a molecule and the eEDM can be measured. This quantity can be combined with E{sub eff}, which is calculated by relativistic molecular orbital theory to determine eEDM. Previous calculations of E{sub eff} were not sufficiently accurate in the treatment ofmore » relativistic or electron correlation effects. We therefore developed a new method to calculate E{sub eff} based on a four-component relativistic coupled-cluster theory. We demonstrated our method for YbF molecule, one of the promising candidates for the eEDM search. Using very large basis set and without freezing any core orbitals, we obtain a value of 23.1 GV/cm for E{sub eff} in YbF with an estimated error of less than 10%. The error is assessed by comparison of our calculations and experiments for two properties relevant for E{sub eff}, permanent dipole moment and hyperfine coupling constant. Our method paves the way to calculate properties of various kinds of molecules which can be described by a single-reference wave function.« less

Improved measurement of the shape of the electron.

PubMed

Hudson, J J; Kara, D M; Smallman, I J; Sauer, B E; Tarbutt, M R; Hinds, E A

2011-05-26

The electron is predicted to be slightly aspheric, with a distortion characterized by the electric dipole moment (EDM), d(e). No experiment has ever detected this deviation. The standard model of particle physics predicts that d(e) is far too small to detect, being some eleven orders of magnitude smaller than the current experimental sensitivity. However, many extensions to the standard model naturally predict much larger values of d(e) that should be detectable. This makes the search for the electron EDM a powerful way to search for new physics and constrain the possible extensions. In particular, the popular idea that new supersymmetric particles may exist at masses of a few hundred GeV/c(2) (where c is the speed of light) is difficult to reconcile with the absence of an electron EDM at the present limit of sensitivity. The size of the EDM is also intimately related to the question of why the Universe has so little antimatter. If the reason is that some undiscovered particle interaction breaks the symmetry between matter and antimatter, this should result in a measurable EDM in most models of particle physics. Here we use cold polar molecules to measure the electron EDM at the highest level of precision reported so far, providing a constraint on any possible new interactions. We obtain d(e) = (-2.4 ± 5.7(stat) ± 1.5(syst)) × 10(-28)e cm, where e is the charge on the electron, which sets a new upper limit of |d(e)| < 10.5 × 10(-28)e cm with 90 per cent confidence. This result, consistent with zero, indicates that the electron is spherical at this improved level of precision. Our measurement of atto-electronvolt energy shifts in a molecule probes new physics at the tera-electronvolt energy scale.

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.

ExoMars 2016 arrives at Mars

NASA Astrophysics Data System (ADS)

Svedhem, Hakan; Vago, Jorge L.; ExoMars Team

2016-10-01

The Trace Gas Orbiter (TGO) and the Schiaparelli Entry, descent and landing Demonstrator Model (EDM) will arrive at Mars on 19 October 2016. The TGO and the EDM are part of the first step of the ExoMars Programme. They will be followed by a Rover and a long lived Surface Platform to be launched in 2020.The EDM is attached to the TGO for the full duration of the cruise to Mars and will be separated three days before arrival at Mars. After separation the TGO will perform a deflection manoeuvre and, on 19 October (during the EDM landing), enter into a highly elliptical near equatorial orbit. TGO will remain in this parking orbit until January 2017, when the orbital plane inclination will be changed to 74 degrees and aerobraking to the final 400 km near circular orbit will start. The final operational orbit is expected to be reached at the end of 2017.The TGO scientific payload consists of four instruments. These are: ACS and NOMAD, both infrared spectrometers for atmospheric measurements in solar occultation mode and in nadir mode, CASSIS, a multichannel camera with stereo imaging capability, and FREND, an epithermal neutron detector for search of subsurface hydrogen. The mass of the TGO is 3700 kg, including fuel. The EDM, with a mass of 600 kg, is mounted on top of the TGO as seen in its launch configuration. The main objective of the EDM is to demonstrate the capability of performing a safe entry, descent and landing on the surface, but it does carry a descent camera and a small battery powered meteorological package that may operate for a few days on the surface.The ExoMars programme is a joint activity by the European Space Agency(ESA) and ROSCOSMOS, Russia. ESA is providing the TGO spacecraft and Schiaparelli (EDM) and two of the TGO instruments and ROSCOSMOS is providing the launcher and the other two TGO instruments. After the arrival of the ExoMars 2020 mission at the surface of Mars, the TGO will handle the communication between the Earth and the Rover and Surface Platform through its (NASA provided) UHF communication system. The 2016 mission was launched by a Russian Proton rocket from Baikonur on 14 March 2016.

Sizable electron/neutron electric dipole moment in D 3 /D 7 μ -split supersymmetry

NASA Astrophysics Data System (ADS)

Dhuria, Mansi; Misra, Aalok

2014-10-01

Within the framework of N =1 gauged supergravity, using a phenomenological model that can be obtained locally as a Swiss-cheese Calabi-Yau string-theoretic compactification with a mobile D 3 -brane localized on a nearly special Lagrangian three cycle in the Calabi-Yau and fluxed stacks of wrapped D 7 -branes, and which provides a natural realization of μ -split supersymmetry (SUSY), we show that in addition to getting a significant value of an [electron/neutron (e/n)] electron dipole moment (EDM) at two-loop level, one can obtain a sizable contribution of (e/n) EDM even at one-loop level due to the presence of heavy supersymmetric fermions nearly isospectral with heavy sfermions. Unlike traditional split SUSY models in which the one-loop diagrams do not give significant contribution to the EDM of the electron/neutron because of very heavy sfermions existing as propagators in the loop, we show that one obtains a "healthy" value of the EDM in our model because of the presence of a heavy Higgsino, neutralino/chargino, and gaugino as fermionic propagators in the loops. The independent C P -violating phases are generated from nontrivial distinct phase factors associated with four Wilson line moduli [identified with first-generation leptons and quarks and their S U (2 )L -singlet cousins] as well as the D 3 -brane position moduli (identified with two Higgses), and the same are sufficient to produce overall distinct phase factors corresponding to all possible effective Yukawas as well as effective gauge couplings that we discuss in the context of N =1 gauged supergravity action. However, the complex phases responsible to generate a nonzero EDM at one-loop level mainly appear from an off-diagonal contribution of sfermion as well as Higgs mass matrices at the electroweak scale (EW). In our analysis, we obtain a dominant contribution of the electron/neutron EDM around de/e ≡O (1 0-29) cm from two-loop diagrams involving heavy sfermions and a light Higgs, and de/e ≡O (1 0-32) cm from a one-loop diagram involving a heavy chargino and a light Higgs as propagators in the loop. The neutron EDM gets a dominant contribution of the order dn/e ≡O (1 0-33) cm from the one-loop diagram involving SM-like quarks and Higgs. To justify the possibility of obtaining a large EDM value in the case of a Barr-Zee diagram which involves W± and the Higgs (responsible to generate the nontrivial C P -violating phase) in the two-loop diagrams as discussed by Leigh et al. [Nucl. Phys. B267, 509 (1986)], we provide an analysis of the same in the context of our D 3 /D 7 μ -split SUSY model at the EW scale. By conjecturing that the C P -violating phase can appear from the diagonalization of the Higgs mass matrix obtained in the context of μ -split SUSY, we also get an EDM of the electron/neutron around O (1 0-27) e cm in the case of the two-loop diagram involving W± bosons.

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.

Understanding Teacher Users of a Digital Library Service: A Clustering Approach

ERIC Educational Resources Information Center

Xu, Beijie; Recker, Mimi

2011-01-01

This article describes the Knowledge Discovery and Data Mining (KDD) process and its application in the field of educational data mining (EDM) in the context of a digital library service called the Instructional Architect (IA.usu.edu). In particular, the study reported in this article investigated a certain type of data mining problem, clustering,…

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.

A Meta-Analysis of Educational Data Mining on Improvements in Learning Outcomes

ERIC Educational Resources Information Center

AlShammari, Iqbal A.; Aldhafiri, Mohammed D.; Al-Shammari, Zaid

2013-01-01

A meta-synthesis study was conducted of 60 research studies on educational data mining (EDM) and their impacts on and outcomes for improving learning outcomes. After an overview, an examination of these outcomes is provided (Romero, Ventura, Espejo, & Hervas, 2008; Romero, "et al.", 2011). Then, a review of other EDM-related research…

Learning Analytics and Educational Data Mining in Practice: A Systematic Literature Review of Empirical Evidence

ERIC Educational Resources Information Center

Papamitsiou, Zacharoula; Economides, Anastasios A.

2014-01-01

This paper aims to provide the reader with a comprehensive background for understanding current knowledge on Learning Analytics (LA) and Educational Data Mining (EDM) and its impact on adaptive learning. It constitutes an overview of empirical evidence behind key objectives of the potential adoption of LA/EDM in generic educational strategic…

B Physics, Hg EDM, and Lepton Flavor Violation in SUSY Models

NASA Astrophysics Data System (ADS)

Shimizu, Yasuhiro

2005-06-01

We consider the correlation between the CP asymmetry in B → ϕKs (SϕKs) and the chromoelectric dipole moment (CEDM) of strange quark (dCs), which is constrained by the electric dipole moment (EDM) of 199Hg, is studied in the SUSY SU(5) GUT with right-handed neutrinos.

Using Data Mining for Predicting Relationships between Online Question Theme and Final Grade

ERIC Educational Resources Information Center

Abdous, M'hammed; He, Wu; Yen, Cherng-Jyh

2012-01-01

As higher education diversifies its delivery modes, our ability to use the predictive and analytical power of educational data mining (EDM) to understand students' learning experiences is a critical step forward. The adoption of EDM by higher education as an analytical and decision making tool is offering new opportunities to exploit the untapped…

Educational Data Mining Applications and Tasks: A Survey of the Last 10 Years

ERIC Educational Resources Information Center

Bakhshinategh, Behdad; Zaiane, Osmar R.; ElAtia, Samira; Ipperciel, Donald

2018-01-01

Educational Data Mining (EDM) is the field of using data mining techniques in educational environments. There exist various methods and applications in EDM which can follow both applied research objectives such as improving and enhancing learning quality, as well as pure research objectives, which tend to improve our understanding of the learning…

Proceedings of the International Conference on Educational Data Mining (EDM) (4th, Eindhoven, the Netherlands, July 6-8, 2011)

ERIC Educational Resources Information Center

Pechenizkiy, Mykola; Calders, Toon; Conati, Cristina; Ventura, Sebastian; Romero, Cristobal; Stamper, John

2011-01-01

The 4th International Conference on Educational Data Mining (EDM 2011) brings together researchers from computer science, education, psychology, psychometrics, and statistics to analyze large datasets to answer educational research questions. The conference, held in Eindhoven, The Netherlands, July 6-9, 2011, follows the three previous editions…

Mercury monohalides: suitability for electron electric dipole moment searches.

PubMed

Prasannaa, V S; Vutha, A C; Abe, M; Das, B P

2015-05-08

Heavy polar diatomic molecules are the primary tools for searching for the T-violating permanent electric dipole moment of the electron (eEDM). Valence electrons in some molecules experience extremely large effective electric fields due to relativistic interactions. These large effective electric fields are crucial to the success of polar-molecule-based eEDM search experiments. Here we report on the results of relativistic ab initio calculations of the effective electric fields in a series of molecules that are highly sensitive to an eEDM, the mercury monohalides (HgF, HgCl, HgBr, and HgI). We study the influence of the halide anions on E_{eff}, and identify HgBr and HgI as attractive candidates for future electric dipole moment search experiments.

Microgravity Electron Electric Dipole Moment Experiment with a Cold Atom Beam

NASA Technical Reports Server (NTRS)

Gould, Harvey

2003-01-01

New physics beyond the Standard Model: The small CP violation contained in the Standard Model is insufficient to account for the baryon/antibaryon asymmetry in the universe. New sources of CP violation are provided by extensions to the Standard Model. They contain CP-violating phases that couple directly to leptons and from which a large electron electric dipole moment (EDM) may be generated. Observation of an electron EDM would be proof of a Standard Model extension because the Standard Model only allows an electron EDM of less than 10(exppp -57) C-m (S.I. units; 1 C-m = 1.6 x 10(exp -21) e-cm). A null result, however, constrains models and improving the limit tightens constraints, further restricting the models.

Mars Reconnaissance Orbiter Navigation Strategy for Dual Support of Insight and ExoMars Entry, Descent and Landing Demonstrator Module in 2016

NASA Technical Reports Server (NTRS)

Wagner, Sean V.; Menon, Premkumar R.; Chung, Min-Kun J.; Williams, Jessica L.

2015-01-01

Mars Reconnaissance Orbiter (MRO) will support NASA's InSight Mission and ESA's ExoMars Entry, Descent and Landing Demonstrator Module (EDM) in the fall of 2016 when both landers arrive at Mars. MRO provided relay support during the Entry, Descent and Landing (EDL) sequences of Mars Phoenix Lander in 2008 and the Mars Science Laboratory in 2012. Unlike these missions, MRO will coordinate between two EDL events separated by only three weeks: InSight on September 28, 2016 and EDM on October 19, 2016. This paper describes MRO Navigation's maneuver strategy to move MRO's ascending node to meet the In- Sight EDL phasing requirement and support EDM.

Cardiac output-based fluid optimization for kidney transplant recipients: a proof-of-concept trial.

PubMed

Corbella, Davide; Toppin, Patrick Jason; Ghanekar, Anand; Ayach, Nour; Schiff, Jeffery; Van Rensburg, Adrian; McCluskey, Stuart A

2018-04-10

Intravenous fluid management for deceased donor kidney transplantation is an important, modifiable risk factor for delayed graft function (DGF). The primary objective of this study was to determine if goal-directed fluid therapy using esophageal Doppler monitoring (EDM) to optimize stroke volume (SV) would alter the amount of fluid given. This randomized, proof-of-concept trial enrolled 50 deceased donor renal transplant recipients. Data collected included patient characteristics, fluid administration, hemodynamics, and complications. The EDM was used to optimize SV in the EDM group. In the control group, fluid management followed the current standard of practice. The groups were compared for the primary outcome of total intraoperative fluid administered. There was no difference in the mean (standard deviation) volume of intraoperative fluid administered to the 24 control and 26 EDM patients [2,307 (750) mL vs 2,675 (842) mL, respectively; mean difference, 368 mL; 95% confidence interval (CI), - 87 to + 823; P = 0.11]. The incidence of complications in the control and EDM groups was similar (15/24 vs 17/26, respectively; P = 0.99), as was the incidence of delayed graft failure (8/24 vs 11/26, respectively; P = 0.36). Goal-directed fluid therapy did not alter the volume of fluid administered or the incidence of complications. This proof-of-concept trial provides needed data for conducting a larger trial to determine the influence of fluid therapy on the incidence in DGF in deceased donor kidney transplantation. www.clinicaltrials.gov (NCT02512731). Registered 31 July 2015.

The Storage Ring Proton EDM Experiment

NASA Astrophysics Data System (ADS)

Semertzidis, Yannis; Storage Ring Proton EDM Collaboration

2014-09-01

The storage ring pEDM experiment utilizes an all-electric storage ring to store ~1011 longitudinally polarized protons simultaneously in clock-wise and counter-clock-wise directions for 103 seconds. The radial E-field acts on the proton EDM for the duration of the storage time to precess its spin in the vertical plane. The ring lattice is optimized to reduce intra-beam scattering, increase the statistical sensitivity and reduce the systematic errors of the method. The main systematic error is a net radial B-field integrated around the ring causing an EDM-like vertical spin precession. The counter-rotating beams sense this integrated field and are vertically shifted by an amount, which depends on the strength of the vertical focusing in the ring, thus creating a radial B-field. Modulating the vertical focusing at 10 kHz makes possible the detection of this radial B-field by a SQUID-magnetometer (SQUID-based BPM). For a total number of n SQUID-based BPMs distributed around the ring the effectiveness of the method is limited to the N = n /2 harmonic of the background radial B-field due to the Nyquist sampling theorem limit. This limitation establishes the requirement to reduce the maximum radial B-field to 0.1-1 nT everywhere around the ring by layers of mu-metal and aluminum vacuum tube. The metho's sensitivity is 10-29 e .cm , more than three orders of magnitude better than the present neutron EDM experimental limit, making it sensitive to SUSY-like new physics mass scale up to 300 TeV.

Studies on mechanical properties of aluminium 6061 reinforced with titanium and E glass fibre metal matrix hybrid composites

NASA Astrophysics Data System (ADS)

Kumar, B. N. Ravi; Vidyasagar, H. N.; Shivanand, H. K.

2018-04-01

2Development of the mmc with fibers and filler materials as a replacement material for some engineering purpose such as automobiles, aerospace are indispensable. Therefore, the studies related to hybrid mmc's of Al6061 were noted in this paper. In this work, Al6061 reinforced with E glass fibers and micro Titanium particles. Hybrid composites was prepared by very feasible and commercially used technique Stir casting and by varying composition of Al6061, Titanium and E-glass fibre. Experiments were done by varying weight fraction of Titanium (0%, 1%, 3% and 5%) and E glass fibre (0%, 1%, 3% and 5%). Wire EDM were used to prepare the specimens required for tensile and hardness according to standards and tests conducted. The proportion of elements which are present the mmc's are identified by EDAX. Optical microscopy were conducted by SU3500 machine Scanning Electron Microscope and Microstructure shows the distribution of reinforced Ti particles and E glass fibres. The characterization of Al6061 hybrid mmc's is having significant impact on the mechanical properties.

The State of Educational Data Mining in 2009: A Review and Future Visions

ERIC Educational Resources Information Center

Baker, Ryan S. J. D.; Yacef, Kalina

2009-01-01

We review the history and current trends in the field of Educational Data Mining (EDM). We consider the methodological profile of research in the early years of EDM, compared to in 2008 and 2009, and discuss trends and shifts in the research conducted by this community. In particular, we discuss the increased emphasis on prediction, the emergence…

Electric dipole moments of light nuclei from {chi}EFT

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

Higa, Renato

I present recent calculations of EDMs of light nuclei using chiral effective field theory techniques. At leading-order, we argue that they can be expressed in terms of six CP-violating low-energy constants. With our expressions, eventual non-zero measurements of EDMs of deuteron, helion, and triton can be combined to disentangle the different sources of CP-violation.

Electric dipole moments of light nuclei from χEFT

NASA Astrophysics Data System (ADS)

Higa, Renato

2013-03-01

I present recent calculations of EDMs of light nuclei using chiral effective field theory techniques. At leading-order, we argue that they can be expressed in terms of six CP-violating low-energy constants. With our expressions, eventual non-zero measurements of EDMs of deuteron, helion, and triton can be combined to disentangle the different sources of CP-violation.

Proceedings of the International Conference on Educational Data Mining (EDM) (6th, Memphis, TN., USA, July 6-9, 2013)

ERIC Educational Resources Information Center

D'Mello, S. K., Ed.; Calvo, R. A., Ed.; Olney, A., Ed.

2013-01-01

Since its inception in 2008, the Educational Data Mining (EDM) conference series has featured some of the most innovative and fascinating basic and applied research centered on data mining, education, and learning technologies. This tradition of exemplary interdisciplinary research has been kept alive in 2013 as evident through an imaginative,…

Manufacturing Laboratory for Next Generation Engineers

DTIC Science & Technology

2013-12-16

automated CNC machines, rapid prototype systems, robotic assembly systems, metrology , and non-traditional systems such as a waterjet cutter, EDM machine...CNC machines, rapid prototype systems, robotic assembly systems, metrology , and non-traditional systems such as a waterjet cutter, EDM machine, plasma...System Metrology and Quality Control Equipment - This area already had a CMM and other well known quality control instrumentation. It has been enhanced

Germline and somatic polymerase ε and δ mutations define a new class of hypermutated colorectal and endometrial cancers

PubMed Central

Briggs, Sarah; Tomlinson, Ian

2013-01-01

Polymerases ϵ and δ are the main enzymes that replicate eukaryotic DNA. Accurate replication occurs through Watson–Crick base pairing and also through the action of the polymerases' exonuclease (proofreading) domains. We have recently shown that germline exonuclease domain mutations (EDMs) of POLE and POLD1 confer a high risk of multiple colorectal adenomas and carcinoma (CRC). POLD1 mutations also predispose to endometrial cancer (EC). These mutations are associated with high penetrance and dominant inheritance, although the phenotype can be variable. We have named the condition polymerase proofreading-associated polyposis (PPAP). Somatic POLE EDMs have also been found in sporadic CRCs and ECs, although very few somatic POLD1 EDMs have been detected. Both the germline and the somatic DNA polymerase EDMs cause an ‘ultramutated’, apparently microsatellite-stable, type of cancer, sometimes leading to over a million base substitutions per tumour. Here, we present the evidence for POLE and POLD1 as important contributors to the pathogenesis of CRC and EC, and highlight some of the key questions in this emerging field. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd PMID:23447401

Correlation of eddy current responses between fatigue cracks and electrical-discharge-machining notches

NASA Astrophysics Data System (ADS)

Seo, Sukho; Choi, Gyudong; Eom, Tae Jhoun; Lee, Bokwon; Lee, Soo Yeol

2017-07-01

The eddy current responses of Electrical Discharge Machining (EDM) notches and fatigue cracks are directly compared to verify the reliability of eddy current inspection. The fatigue crack growth tests using a constant load range control mode were conducted to obtain a variety of edge crack sizes, ranging from 0.9 to 6.6 mm for Al alloy and from 0.1 to 3 mm for Ti alloy. EDM notch specimens of Al and Ti alloys were accordingly prepared in lengths similar to that of the fatigued specimen. The crack length was determined by optical microscope and scanning electron microscope. The eddy current responses between the EDM and fatigued specimens with varying notch/crack length were examined using probe sensors at (100-500) kHz and (1-2) MHz for Al and Ti alloys, respectively. The results show a significant difference in the eddy current signal between the two specimens, based on the correlation between the eddy current response and notch/crack length. This suggests that eddy current inspection using the EDM reference specimen is inaccurate in determining the precise crack size, unless the eddy current response data base is obtained from a fatigue-cracked specimen.

Measurement of Magnetic Field Uniformity For a Neutron Electric Dipole Moment Detector with New Lead Endcaps

NASA Astrophysics Data System (ADS)

Kulkarni, Anita; Filippone, Bradley; Slutsky, Simon; Swank, Christopher; Carr, Robert; Osthelder, Charles; Biswas, Aritra; Molina, Daniel

2016-09-01

Over the last several decades, physicists have been measuring the neutron electric dipole moment (nEDM) with greater and greater sensitivity. The latest experiment we are developing will have 100 times more sensitivity than the previous leading experiment. A nonzero nEDM could, among other consequences, explain the presence of more matter than antimatter in the universe. To measure the nEDM with high accuracy, it is necessary to have a very uniform magnetic field inside the detector since non-uniformities can create false signals via the geometric phase effect. One way to improve field uniformity is to add superconducting lead endcaps to the detector, which constrain the fields at their surfaces to be parallel to them. Here, we test how the endcaps improve field uniformity by measuring the magnetic field at various points in a 1/3-scale experimental volume, inferring what the field must be at all other points, and calculating gradients in the field. This knowledge could help guide further steps needed to improve field uniformity and characterize limitations to the sensitivity of nEDM measurements for the full-scale experiment. Rose Hills Foundation, National Science Foundation Grant 1506459, and Department of Energy.

Search for a Neutron Electric Dipole Moment

PubMed Central

Golub, R.; Huffman, P. R.

2005-01-01

The possible existence of a nonzero electric dipole moment (EDM) of the neutron is of great fundamental interest in itself and directly impacts our understanding of the nature of electro-weak and strong interactions. The experimental search for this moment has the potential to reveal new sources of T and CP violation and to challenge calculations that propose extensions to the Standard Model. The goal of the current experiment is to significantly improve the measurement sensitivity to the neutron EDM over what is reported in the literature. The experiment has the potential to either measure the magnitude of the neutron EDM or to lower the current experimental limit by two orders of magnitude. Achieving these objectives will have a major impact on our understanding of the physics of both weak and strong interactions. PMID:27308116

Simulation of Light Collection for Neutron Electrical Dipole Moment measurement

NASA Astrophysics Data System (ADS)

Ji, Pan; nEDM Collaboration

2017-09-01

nEDM (Neutron Electrical Dipole moment) measurement addresses a critical topic in particle physics and Standard Model, that is CPT violation in neutron electrical dipole moment if detected in which the Time reversal violation is connected to the matter/antimatter imparity of the universe. The neutron electric dipole moment was first measured in 1950 by Smith, Purcell, and Ramsey at the Oak Ridge Reactor - the first intense neutron source. This measurement showed that the neutron was very nearly round (to better than one part in a million). The goal of the nEDM experiment is to further improve the precision of this measurement by another factor of 100. The signal from the experiment is detected by collecting the photons generated when neutron beams were captured by liquid helium 3. The Geant4 simulation project that I participate simulates the process of light collection to improve the design for higher capture efficiency. The simulated geometry includes light source, reflector, wavelength shifting fibers, wavelength shifting TPB and acrylic as in real experiment. The UV photons exiting from Helium go through two wavelength-shifting processes in TPB and fibers to be finally captured. Oak Ridge National Laboratory Neutron Electric Dipole Moment measurement project.

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).

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.

Proceedings of the International Conference on Educational Data Mining (EDM) (8th, Madrid, Spain, June 26-29, 2015)

ERIC Educational Resources Information Center

Santos, Olga Cristina, Ed.; Boticario, Jesus Gonzalez, Ed.; Romero, Cristobal, Ed.; Pechenizkiy, Mykola, Ed.; Merceron, Agathe, Ed.; Mitros, Piotr, Ed.; Luna, Jose Maria, Ed.; Mihaescu, Cristian, Ed.; Moreno, Pablo, Ed.; Hershkovitz, Arnon, Ed.; Ventura, Sebastian, Ed.; Desmarais, Michel, Ed.

2015-01-01

The 8th International Conference on Educational Data Mining (EDM 2015) is held under auspices of the International Educational Data Mining Society at UNED, the National University for Distance Education in Spain. The conference held in Madrid, Spain, July 26-29, 2015, follows the seven previous editions (London 2014, Memphis 2013, Chania 2012,…

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

Emergency Department Patient Burden from an Electronic Dance Music Festival.

PubMed

Chhabra, Neeraj; Gimbar, Renee P; Walla, Lisa M; Thompson, Trevonne M

2018-04-01

Electronic dance music (EDM) festivals are increasingly common and psychoactive substance use is prevalent. Although prehospital care can obviate the transfer of many attendees to health care facilities (HCFs), little is known regarding the emergency department (ED) burden of patients presenting from EDM festivals. This study describes the patient volume, length of stay (LOS), and presenting complaints of patients from a 3-day EDM festival in close proximity to an area ED. Medical charts of patients presenting to one HCF from an EDM festival were reviewed for substances used, ED LOS, and sedative medications administered. Additionally, preparedness techniques are described. Over the 3-day festival, 28 patients presented to the ED (median age 21 years; range 18-29 years). Twenty-five had complaints related to substance use including ethanol (n = 18), "molly" or "ecstasy" (n = 13), and marijuana (n = 8). Three patients required intensive care or step-down unit admission for endotracheal intubation, rhabdomyolysis, and protracted altered mental status. The median LOS for discharged patients was 265 min (interquartile range 210-347 min). Eleven patients required the use of sedative medications, with cumulative doses of 42 mg of lorazepam and 350 mg of ketamine. All patients presented within the hours of 5:00 pm and 2:15 am. The majority of ED visits from an EDM festival were related to substance use. ED arrival times clustered during the evening and were associated with prolonged LOS. Few patients required hospital admission, but admitted patients required high levels of care. HCFs should use these data as a guide in planning for future events. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Contributions of axionlike particles to lepton dipole moments

DOE PAGES

Marciano, W. J.; Masiero, A.; Paradisi, P.; ...

2016-12-30

We examined contributions of a spin-0 axionlike particle (ALP) to lepton dipole moments, g - 2 and EDMs. Barr-Zee and light-by-light loop effects from a light pseudoscalar ALP are found to be capable of resolving the longstanding muon g - 2 discrepancy at the expense of relatively large ALP - γ γ couplings. We also discussed the compatibility of such large couplings with direct experimental constraints and perturbative unitarity bounds. Future tests of such a scenario are described. For C P -violating ALP couplings, the electron EDM is found to probe much smaller, theoretically more easily accommodated ALP interactions. Wemore » advocate future planned improvements in electron EDM searches as a way to not only significantly constrain ALP parameters, but also potentially unveil a new source of C P violation which could have far-reaching ramifications.« less

Is there room for C P violation in the top-Higgs sector?

DOE PAGES

Cirigliano, Vincenzo; Dekens, Wouter Gerard; de Vries, Jordy; ...

2016-07-21

Here, we discuss direct and indirect probes of chirality-flipping couplings of the top quark to Higgs and gauge bosons, considering both CP-conserving and CP-violating observables, in the framework of the Standard Model effective field theory. In our analysis we include current and prospective constraints from collider physics, precision electroweak tests, flavor physics, and electric dipole moments (EDMs). We find that low-energy indirect probes are very competitive, even after accounting for long-distance uncertainties. In particular, EDMs put constraints on the electroweak CP-violating dipole moments of the top that are 2 to 3 orders of magnitude stronger than existing limits. The newmore » indirect constraint on the top EDM is given by |d t| < 5×10 –20e cm at 90% C.L.« less

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

Effect of Carbon in the Dielectric Fluid and Workpieces on the Characteristics of Recast Layers Machined by Electrical Discharge Machining

NASA Astrophysics Data System (ADS)

Muttamara, Apiwat; Kanchanomai, Chaosuan

2016-06-01

Electrical discharge machining (EDM) is a popular non-traditional machining technique that is usually performed in kerosene. Carbon from the kerosene is mixed into the recast layer during EDM, increasing its hardness. EDM can be performed in deionized water, which causes decarburization. We studied the effects of carbon in the dielectric fluid and workpiece on the characteristics of recast layers. Experiments were conducted using gray cast iron and mild steel workpieces in deionized water or kerosene under identical operating conditions. Scanning electron microscopy revealed that the recast layer formed on gray iron was rougher than that produced on mild steel. Moreover, the dispersion of graphite flakes in the gray iron seemed to cause subsurface cracks, even when EDM was performed in deionized water. Dendritic structures and iron carbides were found in the recast layer of gray iron treated in deionized water. Kerosene caused more microcracks to form and increased surface roughness compared with deionized water. The microcrack length per unit area of mild steel treated in deionized water was greater than that treated in kerosene, but the cracks formed in kerosene were wider. The effect of the diffusion of carbon during cooling on the characteristics of the recast layer was discussed.

Improved Limits on Axionlike-Particle-Mediated P , T -Violating Interactions between Electrons and Nucleons from Electric Dipole Moments of Atoms and Molecules

NASA Astrophysics Data System (ADS)

Stadnik, Y. V.; Dzuba, V. A.; Flambaum, V. V.

2018-01-01

In the presence of P , T -violating interactions, the exchange of axionlike particles between electrons and nucleons in atoms and molecules induces electric dipole moments (EDMs) of atoms and molecules. We perform calculations of such axion-exchange-induced atomic EDMs using the relativistic Hartree-Fock-Dirac method including electron core polarization corrections. We present analytical estimates to explain the dependence of these induced atomic EDMs on the axion mass and atomic parameters. From the experimental bounds on the EDMs of atoms and molecules, including Cs 133 , Tl 205 , Xe 129 , Hg 199 , Yb 171 F 19 , Hf 180 F+ 19 , and Th 232 O 16 , we constrain the P , T -violating scalar-pseudoscalar nucleon-electron and electron-electron interactions mediated by a generic axionlike particle of arbitrary mass. Our limits improve on existing laboratory bounds from other experiments by many orders of magnitude for ma≳10-2 eV . We also place constraints on C P violation in certain types of relaxion models.

Application of the finite-field coupled-cluster method to calculate molecular properties relevant to electron electric-dipole-moment searches

NASA Astrophysics Data System (ADS)

Abe, M.; Prasannaa, V. S.; Das, B. P.

2018-03-01

Heavy polar diatomic molecules are currently among the most promising probes of fundamental physics. Constraining the electric dipole moment of the electron (e EDM ), in order to explore physics beyond the standard model, requires a synergy of molecular experiment and theory. Recent advances in experiment in this field have motivated us to implement a finite-field coupled-cluster (FFCC) approach. This work has distinct advantages over the theoretical methods that we had used earlier in the analysis of e EDM searches. We used relativistic FFCC to calculate molecular properties of interest to e EDM experiments, that is, the effective electric field (Eeff) and the permanent electric dipole moment (PDM). We theoretically determine these quantities for the alkaline-earth monofluorides (AEMs), the mercury monohalides (Hg X ), and PbF. The latter two systems, as well as BaF from the AEMs, are of interest to e EDM searches. We also report the calculation of the properties using a relativistic finite-field coupled-cluster approach with single, double, and partial triples' excitations, which is considered to be the gold standard of electronic structure calculations. We also present a detailed error estimate, including errors that stem from our choice of basis sets, and higher-order correlation effects.

Accurate optimization of amino acid form factors for computing small-angle X-ray scattering intensity of atomistic protein structures

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

Tong, Dudu; Yang, Sichun; Lu, Lanyuan

2016-06-20

Structure modellingviasmall-angle X-ray scattering (SAXS) data generally requires intensive computations of scattering intensity from any given biomolecular structure, where the accurate evaluation of SAXS profiles using coarse-grained (CG) methods is vital to improve computational efficiency. To date, most CG SAXS computing methods have been based on a single-bead-per-residue approximation but have neglected structural correlations between amino acids. To improve the accuracy of scattering calculations, accurate CG form factors of amino acids are now derived using a rigorous optimization strategy, termed electron-density matching (EDM), to best fit electron-density distributions of protein structures. This EDM method is compared with and tested againstmore » other CG SAXS computing methods, and the resulting CG SAXS profiles from EDM agree better with all-atom theoretical SAXS data. By including the protein hydration shell represented by explicit CG water molecules and the correction of protein excluded volume, the developed CG form factors also reproduce the selected experimental SAXS profiles with very small deviations. Taken together, these EDM-derived CG form factors present an accurate and efficient computational approach for SAXS computing, especially when higher molecular details (represented by theqrange of the SAXS data) become necessary for effective structure modelling.« 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.

A big measurement of a small moment

NASA Astrophysics Data System (ADS)

E Sauer, B.; Devlin, J. A.; Rabey, I. M.

2017-07-01

A beam of ThO molecules has been used to make the most precise measurement of the electron’s electric dipole moment (EDM) to date. In their recent paper, the ACME collaboration set out in detail their experimental and data analysis techniques. In a tour-de-force, they explain the many ways in which their apparatus can produce a signal which mimics the EDM and show how these systematic effects are measured and controlled.

Constraints on T-Odd, P-Even Interactions from Electric Dipole Moments

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

A. Kurylov; G. C. McLaughlin; M.J. Ramsey-Musolf

2001-03-01

We construct the relationship between nonrenormalizable,effective, time-reversal violating (TV) parity-conserving (PC) interactions of quarks and gauge bosons and various low-energy TVPC and TV parity-violating (PV) observables. Using effective field theory methods, we delineate the scenarios under which experimental limits on permanent electric dipole moments (EDM's) of the electron, neutron, and neutral atoms as well as limits on TVPC observables provide the most stringent bounds on new TVPC interactions. Under scenarios in which parity invariance is restored at short distances, the one-loop EDM of elementary fermions generate the most severe constraints. The limits derived from the atomic EDM of {sup 199}Hgmore » are considerably weaker. When parity symmetry remains broken at short distances, direct TVPC search limits provide the least ambiguous bounds. The direct limits follow from TVPC interactions between two quarks.« less

Planning and Prototyping for a Storage Ring Measurement of the Proton Electric Dipole Moment

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

Talman, Richard

2015-07-01

Electron and proton EDM's can be measured in "frozen spin" (with the beam polarization always parallel to the orbit, for example) storage rings. For electrons the "magic" kinetic energy at which the beam can be frozen is 14.5 MeV. For protons the magic kinetic energy is 230 MeV. The currently measured upper limit for the electron EDM is much smaller than the proton EDM upper limit, which is very poorly known. Nevertheless, because the storage ring will be an order of magnitude cheaper, a sensible plan is to first build an all-electric electron storage ring as a prototype. Such anmore » electron ring was successfully built at Brookhaven, in 1954, as a prototype for their AGS ring. This leaves little uncertainty concerning the cost and performance of such a ring. (This is documentedin one of the Physical Review papers mentioned above.)« less

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

Talman, Richard M.; Talman, John D.

Proposed methods for measuring the electric dipole moment (EDM) of the proton use an intense, polarized proton beam stored in an all-electric storage ring “trap.” At the “magic” kinetic energy of 232.792 MeV, proton spins are “frozen,” for example always parallel to the instantaneous particle momentum. Energy deviation from the magic value causes in-plane precession of the spin relative to the momentum. Any nonzero EDM value will cause out-of-plane precession—measuring this precession is the basis for the EDM determination. A proposed implementation of this measurement shows that a proton EDM value of 10 –29e–cm or greater will produce a statisticallymore » significant, measurable precession after multiply repeated runs, assuming small beam depolarization during 1000 s runs, with high enough precision to test models of the early universe developed to account for the present day particle/antiparticle population imbalance. This paper describes an accelerator simulation code, eteapot, a new component of the Unified Accelerator Libraries (ual), to be used for long term tracking of particle orbits and spins in electric bend accelerators, in order to simulate EDM storage ring experiments. Though qualitatively much like magnetic rings, the nonconstant particle velocity in electric rings gives them significantly different properties, especially in weak focusing rings. Like the earlier code teapot (for magnetic ring simulation) this code performs exact tracking in an idealized (approximate) lattice rather than the more conventional approach, which is approximate tracking in a more nearly exact lattice. The Bargmann-Michel-Telegdi (BMT) equation describing the evolution of spin vectors through idealized bend elements is also solved exactly—original to this paper. Furthermore the idealization permits the code to be exactly symplectic (with no artificial “symplectification”). Any residual spurious damping or antidamping is sufficiently small to permit reliable tracking for the long times, such as the 1000 s assumed in estimating the achievable EDM precision. This paper documents in detail the theoretical formulation implemented in eteapot. An accompanying paper describes the practical application of the eteapot code in the Universal Accelerator Libraries (ual) environment to “resurrect,” or reverse engineer, the “AGS-analog” all-electric ring built at Brookhaven National Laboratory in 1954. Of the (very few) all-electric rings ever commissioned, the AGS-analog ring is the only relativistic one and is the closest to what is needed for measuring proton (or, even more so, electron) EDM’s. As a result, the companion paper also describes preliminary lattice studies for the planned proton EDM storage rings as well as testing the code for long time orbit and spin tracking.« less

Symplectic orbit and spin tracking code for all-electric storage rings

DOE PAGES

Talman, Richard M.; Talman, John D.

2015-07-22

Proposed methods for measuring the electric dipole moment (EDM) of the proton use an intense, polarized proton beam stored in an all-electric storage ring “trap.” At the “magic” kinetic energy of 232.792 MeV, proton spins are “frozen,” for example always parallel to the instantaneous particle momentum. Energy deviation from the magic value causes in-plane precession of the spin relative to the momentum. Any nonzero EDM value will cause out-of-plane precession—measuring this precession is the basis for the EDM determination. A proposed implementation of this measurement shows that a proton EDM value of 10 –29e–cm or greater will produce a statisticallymore » significant, measurable precession after multiply repeated runs, assuming small beam depolarization during 1000 s runs, with high enough precision to test models of the early universe developed to account for the present day particle/antiparticle population imbalance. This paper describes an accelerator simulation code, eteapot, a new component of the Unified Accelerator Libraries (ual), to be used for long term tracking of particle orbits and spins in electric bend accelerators, in order to simulate EDM storage ring experiments. Though qualitatively much like magnetic rings, the nonconstant particle velocity in electric rings gives them significantly different properties, especially in weak focusing rings. Like the earlier code teapot (for magnetic ring simulation) this code performs exact tracking in an idealized (approximate) lattice rather than the more conventional approach, which is approximate tracking in a more nearly exact lattice. The Bargmann-Michel-Telegdi (BMT) equation describing the evolution of spin vectors through idealized bend elements is also solved exactly—original to this paper. Furthermore the idealization permits the code to be exactly symplectic (with no artificial “symplectification”). Any residual spurious damping or antidamping is sufficiently small to permit reliable tracking for the long times, such as the 1000 s assumed in estimating the achievable EDM precision. This paper documents in detail the theoretical formulation implemented in eteapot. An accompanying paper describes the practical application of the eteapot code in the Universal Accelerator Libraries (ual) environment to “resurrect,” or reverse engineer, the “AGS-analog” all-electric ring built at Brookhaven National Laboratory in 1954. Of the (very few) all-electric rings ever commissioned, the AGS-analog ring is the only relativistic one and is the closest to what is needed for measuring proton (or, even more so, electron) EDM’s. As a result, the companion paper also describes preliminary lattice studies for the planned proton EDM storage rings as well as testing the code for long time orbit and spin tracking.« less

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.

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

How Expert Pilots Think Cognitive Processes in Expert Decision Making

DTIC Science & Technology

1993-02-01

Management (CRM) This document is available to the public Advanced Qualification Program (AQP) through the National Technical Information Cognitive Task Analysis (CTA...8217 Selecting realistic EDM scenarios with critical events and performing a cognitive task analysis of novice vs. expert decision making for these events...scenarios with critical events and performing a cognitive task analysis of novice vs. expert decision making for these events is a basic requirement for

Item Unique Identification Capability Expansion: Established Process Analysis, Cost Benefit Analysis, and Optimal Marking Procedures

DTIC Science & Technology

2014-12-01

chemical etching EDM electrical discharge machine EID enterprise identifier EOSS Engineering Operational Sequencing System F Fahrenheit...Center in Corona , California, released a DoN IUID Marking Guide, which made recommendations on how to mark legacy items. It provides technical...uploaded into the IUID registry managed by the Naval Surface Warfare Center (NSWC) in Corona , California. There is no set amount of information

Fit of cast commercially pure titanium and Ti-6Al-4V alloy crowns before and after marginal refinement by electrical discharge machining.

PubMed

Contreras, Edwin Fernando Ruiz; Henriques, Guilherme Elias Pessanha; Giolo, Suely Ruiz; Nobilo, Mauro Antonio Arruda

2002-11-01

Titanium has been suggested as a replacement for alloys currently used in single-tooth restorations and fixed partial dentures. However, difficulties in casting have resulted in incomplete margins and discrepancies in marginal fit. This study evaluated and compared the marginal fit of crowns fabricated from a commercially pure titanium (CP Ti) and from Ti-6Al-4V alloy with crowns fabricated from a Pd-Ag alloy that served as a control. Evaluations were performed before and after marginal refinement by electrical discharge machining (EDM). Forty-five bovine teeth were prepared to receive complete cast crowns. Stone and copper-plated dies were obtained from impressions. Fifteen crowns were cast with each alloy (CP Ti, Ti-6Al-4V, and Pd-Ag). Marginal fit measurements (in micrometers) were recorded at 4 reference points on each casting with a traveling microscope. Marginal refinement with EDM was conducted on the titanium-based crowns, and measurements were repeated. Data were analyzed with the Kruskal-Wallis test, paired t test, and independent t test at a 1% probability level. The Kruskal-Wallis test showed significant differences among mean values of marginal fit for the as-cast CP Ti crowns (mean [SD], 83.9 [26.1] microm) and the other groups: Ti-6Al-4V (50.8 [17.2] microm) and Pd-Ag (45.2 [10.4] microm). After EDM marginal refinement, significant differences were detected among the Ti-6Al-4V crowns (24.5 [10.9] microm) and the other 2 groups: CP Ti (50.6 [20.0] microm) and Pd-Ag (not modified by EDM). Paired t test results indicated that marginal refinement with EDM effectively improved the fit of CP Ti crowns (from 83.9 to 50.6 microm) and Ti-6Al-4V crowns (from 50.8 to 24.5 microm). However, the difference in improvement between the two groups was not significant by t test. Within the limitations of this study, despite the superior results for Ti-6Al-4V, both groups of titanium-based crowns had clinically acceptable marginal fits. After EDM marginal refinement, the fit of cast CP Ti and Ti-6Al-4V crowns improved significantly.

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.

Toward Rotational State-Selective Photoionization of ThF+ Ions

NASA Astrophysics Data System (ADS)

Zhou, Yan; Ng, Kia Boon; Gresh, Dan; Cairncross, William; Grau, Matt; Ni, Yiqi; Cornell, Eric; Ye, Jun

2016-06-01

ThF+ has been chosen to replace HfF+ for a second-generation measurement of the electric dipole moment of the electron (eEDM). Compared to the currently running HfF+ eEDM experiment, ThF+ has several advantages: (i) the eEDM-sensitive state (3Δ1) is the ground state, which facilitates a long coherence time [1]; (ii) its effective electric field (35 GV/cm) is 50% larger than that of HfF+, which promises a direct increase of the eEDM sensitivity [2]; and (iii) the ionization energy of neutral ThF is lower than its dissociation energy, which introduces greater flexibility in rotational state-selective photoionization via core-nonpenetrating Rydberg states [3]. In this talk, we first present our strategy of preparing and utilizing core-nonpenetrating Rydberg states for rotational state-selective ionization. Then, we report spectroscopic data of laser-induced fluorescence of neutral ThF, which provides critical information for multi-photon ionization spectroscopy. [1] D. N. Gresh, K. C. Cossel, Y. Zhou, J. Ye, E. A. Cornell, Journal of Molecular Spectroscopy, 319 (2016), 1-9 [2] M. Denis, M. S. Nørby, H. J. A. Jensen, A. S. P. Gomes, M. K. Nayak, S. Knecht, T. Fleig, New Journal of Physics, 17 (2015) 043005. [3] Z. J. Jakubek, R. W. Field, Journal of Molecular Spectroscopy 205 (2001) 197-220.

Biochemical Effects of Energy Drinks Alone or in Combination with Alcohol in Normal Albino Rats

PubMed Central

2014-01-01

Purpose: To determine the biochemical effects of energy drink alone or in combination with alcohol in normal albino rats. Methods: Twenty male albino rats weighing 160-180g were assigned into groups A-E of four rats per group. Group A and B rats were given low and high doses of ED, respectively, groups C and D were administered low and high doses of EDmA, respectively while group E rats were given distilled water and served as control. The treatment lasted for 30 days after which the animals were killed and their blood collected for laboratory analyses using standard methods. Results: There were no significant differences in body weight, packed cell volume and haemoglobin concentration with either administration of ED or EDmA in comparison to the control. Energy drink alone or EDmA has significant effects on total white blood cell count, plasma potassium, calcium, renal functions, liver enzymes and plasma triglycerides, with EDmA having more effects than ED alone, except for body weight where the energy drink alone has higher effect. Conclusion: Consumption of energy drink alone or in combination with alcohol is associated with significant alterations in some biochemical parameters. Caution should be exercised while consuming either of them. Public health education is urgently needed to correct the wrong impression already formed by the unsuspecting consumers, especially the youths. PMID:24409412

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.

Experimental Investigation Nano Particles Influence in NPMEDM to Machine Inconel 800 with Electrolyte Copper Electrode

NASA Astrophysics Data System (ADS)

Karunakaran, K.; Chandrasekaran, M.

2017-05-01

The recent technology of machining hard materials is Powder mix dielectric electrical Discharge Machining (PMEDM). This research investigates nano sized (about 5Nm) powders influence in machining Inconel 800 nickel based super alloy. This work is motivated for a practical need for a manufacturing industry, which processes various kinds of jobs of Inconel 800 material. The conventional EDM machining also considered for investigation for the measure of Nano powders performances. The aluminum, silicon and multi walled Carbon Nano tubes powders were considered in this investigation along with pulse on time, pulse of time and input current to analyze and optimize the responses of Material Removal Rate, Tool Wear Rate and surface roughness. The Taguchi general Full Factorial Design was used to design the experiments. The most advance equipments employed in conducting experiments and measuring equipments to improve the accuracy of the result. The MWCNT powder mix was out performs than other powders which reduce 22% to 50% of the tool wear rate, gives the surface roughness reduction from 29.62% to 41.64% and improved MRR 42.91% to 53.51% than conventional EDM.

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.

Effects of pulse ON and OFF time and electrode types on the material removal rate and tool wear rate of the Ti-6Al-4V Alloy using EDM machining with reverse polarity

NASA Astrophysics Data System (ADS)

Praveen, L.; Geeta Krishna, P.; Venugopal, L.; Prasad, N. E. C.

2018-03-01

Electrical Discharge Machining (EDM) is an unconventional metal removal process that is extensively used for removing the difficult-to-machine metal such as Ti alloys, super alloys and metal matrix composites. This paper investigates the effects of pulse (ON/OFF) time on EDM machining characteristics of Ti-6Al-4V alloy using copper and graphite as electrodes in reverse polarity condition. Full factorial design method was used to design the experiments. Two variables (Pulse On and OFF) with three levels are considered. The output variables are the tool wear rate and the material removal rate. The important findings from the present work are: (1) the material removal rate (MRR) increases gradually with an increase of the Pulse ON time whereas the change is insignificant with an increase of the Pulse OFF time, (2) Between copper and graphite electrodes, the copper electrode is proved to be good in terms of MRR, (3) a combination of high pulse ON time and OFF time is desirable for high MRR rate in the Cu electrode whereas for the graphite electrode, a combination of high pulse ON time and low pulse OFF time is desirable for high MRR rate, (4) the tool wear rate (TWR) reduces with the Pulse On or OFF time, the rate of TWR is uniform for the graphite electrode in contrast to abrupt decrease from 25 to 50 μs (pulse ON time) in the copper electrode, (5) In order to keep the TWR as minimum possible, it is desirable to have a combination of high pulse ON time and OFF time for both the copper and the graphite electrode.

Building Bridges between Perceptual and Economic Decision-Making: Neural and Computational Mechanisms.

PubMed

Summerfield, Christopher; Tsetsos, Konstantinos

2012-01-01

Investigation into the neural and computational bases of decision-making has proceeded in two parallel but distinct streams. Perceptual decision-making (PDM) is concerned with how observers detect, discriminate, and categorize noisy sensory information. Economic decision-making (EDM) explores how options are selected on the basis of their reinforcement history. Traditionally, the sub-fields of PDM and EDM have employed different paradigms, proposed different mechanistic models, explored different brain regions, disagreed about whether decisions approach optimality. Nevertheless, we argue that there is a common framework for understanding decisions made in both tasks, under which an agent has to combine sensory information (what is the stimulus) with value information (what is it worth). We review computational models of the decision process typically used in PDM, based around the idea that decisions involve a serial integration of evidence, and assess their applicability to decisions between good and gambles. Subsequently, we consider the contribution of three key brain regions - the parietal cortex, the basal ganglia, and the orbitofrontal cortex (OFC) - to perceptual and EDM, with a focus on the mechanisms by which sensory and reward information are integrated during choice. We find that although the parietal cortex is often implicated in the integration of sensory evidence, there is evidence for its role in encoding the expected value of a decision. Similarly, although much research has emphasized the role of the striatum and OFC in value-guided choices, they may play an important role in categorization of perceptual information. In conclusion, we consider how findings from the two fields might be brought together, in order to move toward a general framework for understanding decision-making in humans and other primates.

Building Bridges between Perceptual and Economic Decision-Making: Neural and Computational Mechanisms

PubMed Central

Summerfield, Christopher; Tsetsos, Konstantinos

2012-01-01

Investigation into the neural and computational bases of decision-making has proceeded in two parallel but distinct streams. Perceptual decision-making (PDM) is concerned with how observers detect, discriminate, and categorize noisy sensory information. Economic decision-making (EDM) explores how options are selected on the basis of their reinforcement history. Traditionally, the sub-fields of PDM and EDM have employed different paradigms, proposed different mechanistic models, explored different brain regions, disagreed about whether decisions approach optimality. Nevertheless, we argue that there is a common framework for understanding decisions made in both tasks, under which an agent has to combine sensory information (what is the stimulus) with value information (what is it worth). We review computational models of the decision process typically used in PDM, based around the idea that decisions involve a serial integration of evidence, and assess their applicability to decisions between good and gambles. Subsequently, we consider the contribution of three key brain regions – the parietal cortex, the basal ganglia, and the orbitofrontal cortex (OFC) – to perceptual and EDM, with a focus on the mechanisms by which sensory and reward information are integrated during choice. We find that although the parietal cortex is often implicated in the integration of sensory evidence, there is evidence for its role in encoding the expected value of a decision. Similarly, although much research has emphasized the role of the striatum and OFC in value-guided choices, they may play an important role in categorization of perceptual information. In conclusion, we consider how findings from the two fields might be brought together, in order to move toward a general framework for understanding decision-making in humans and other primates. PMID:22654730

Characterization of irradiated AISI 316L stainless steel disks removed from the Spallation Neutron Source

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

Vevera, Bradley J; Hyres, James W; McClintock, David A

2014-01-01

Irradiated AISI 316L stainless steel disks were removed from the Spallation Neutron Source (SNS) for post-irradiation examination (PIE) to assess mechanical property changes due to radiation damage and erosion of the target vessel. Topics reviewed include high-resolution photography of the disk specimens, cleaning to remove mercury (Hg) residue and surface oxides, profile mapping of cavitation pits using high frequency ultrasonic testing (UT), high-resolution surface replication, and machining of test specimens using wire electrical discharge machining (EDM), tensile testing, Rockwell Superficial hardness testing, Vickers microhardness testing, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The effectiveness of the cleaning proceduremore » was evident in the pre- and post-cleaning photography and permitted accurate placement of the test specimens on the disks. Due to the limited amount of material available and the unique geometry of the disks, machine fixturing and test specimen design were critical aspects of this work. Multiple designs were considered and refined during mock-up test runs on unirradiated disks. The techniques used to successfully machine and test the various specimens will be presented along with a summary of important findings from the laboratory examinations.« less

Technology for pressure-instrumented thin airfoil models, phase 1

NASA Technical Reports Server (NTRS)

Wigley, D. A.

1985-01-01

A network of channels was chemically milled into one surface of a pair of matched plates having bond planes which were neither planar or profiled to match the contour of the trailing edge of a supercritical airfoil for testing in cryogenic wind tunnels. Vacuum brazing bonded the plates together to create a network of pressure passages without blockages or cross leaks. The greatest success was achieved with the smaller samples and planar bonding surfaces. In larger samples, problems were encountered due to warpage created by the relief of residual stresses. Successful bonds were formed by brazing A286, Nitronic 40 and 300 series stainless steels at 1065 C using AMS 4777B brazing alloy, but excessive grain growth occurred in samples of 200 grade 18 nickel maraging steels. Good bonds were obtained with maraging steel using a 47 percent Nickel-47 percent Palladium-6 percent Silicon alloy and brazing at 927 C. Electro-Discharge-Machining was an effective method of cutting profiled bond planes and airfoil contours. Orifices of good definition were obtained when the EDM wire cut passed through predrilled holes. Possible configurations for joints between small segments and the larger main wing were also studied.

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.

Proceedings of the Seventh International Conference on Educational Data Mining (EDM) (7th, London, United Kingdom, July 4-7, 2014)

ERIC Educational Resources Information Center

Stamper, John, Ed.; Pardos, Zachary, Ed.; Mavrikis, Manolis, Ed.; McLaren, Bruce M., Ed.

2014-01-01

The 7th International Conference on Education Data Mining held on July 4th-7th, 2014, at the Institute of Education, London, UK is the leading international forum for high-quality research that mines large data sets in order to answer educational research questions that shed light on the learning process. These data sets may come from the traces…

Enhanced global Radionuclide Source Attribution for the Nuclear-Test-Ban Verification by means of the Adjoint Ensemble Dispersion Modeling Technique applied at the IDC/CTBTO.

NASA Astrophysics Data System (ADS)

Becker, A.; Wotawa, G.; de Geer, L.

2006-05-01

The Provisional Technical Secretariat (PTS) of the CTBTO Preparatory Commission maintains and permanently updates a source-receptor matrix (SRM) describing the global monitoring capability of a highly sensitive 80 stations radionuclide (RN) network in order to verify states signatories' compliance of the comprehensive nuclear-test-ban treaty (CTBT). This is done by means of receptor-oriented Lagrangian particle dispersion modeling (LPDM) to help determine the region from which suspicious radionuclides may originate. In doing so the LPDM FLEXPART5.1 is integrated backward in time based on global analysis wind fields yielding global source-receptor sensitivity (SRS) fields stored in three-hour frequency and at 1º horizontal resolution. A database of these SRS fields substantially helps in improving the interpretation of the RN samples measurements and categorizations because it enables the testing of source-hypothesis's later on in a pure post-processing (SRM inversion) step being feasible on hardware with specifications comparable to currently sold PC's or Notebooks and at any place (decentralized), provided access to the SRS fields is warranted. Within the CTBT environment it is important to quickly achieve decision-makers confidence in the SRM based backtracking products issued by the PTS in the case of the occurrence of treaty relevant radionuclides. Therefore the PTS has set up a highly automated response system together with the Regional Specialized Meteorological Centers of the World Meteorological Organization in the field of dispersion modeling who committed themselves to provide the PTS with the same standard SRS fields as calculated by their systems for CTBT relevant cases. This system was twice utilized in 2005 in order to perform adjoint ensemble dispersion modeling (EDM) and demonstrated the potential of EDM based backtracking to improve the accuracy of the source location related to singular nuclear events thus serving the backward analogue to the findings of the ensemble dispersion modeling (EDM) technique No. 5 efforts performed by Galmarini et al, 2004 (Atmos. Env. 38, 4607-4617). As the scope of the adjoint EDM methodology is not limited to CTBT verification but can be applied to any kind of nuclear event monitoring and location it bears the potential to improve the design of manifold emergency response systems towards preparedness concepts as needed for mitigation of disasters (like Chernobyl) and pre-emptive estimation of pollution hazards.

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.

Improvements of fabrication processes and enhancement of critical current densities in (Ba,K)Fe2As2 HIP wires and tapes

NASA Astrophysics Data System (ADS)

Pyon, Sunseng; Suwa, Takahiro; Tamegai, Tsuyoshi; Takano, Katsutoshi; Kajitani, Hideki; Koizumi, Norikiyo; Awaji, Satoshi; Zhou, Nan; Shi, Zhixiang

2018-05-01

We fabricated (Ba,K)Fe2As2 superconducting wires and tapes using the powder-in-tube method and hot isostatic pressing (HIP). HIP wires and tapes showed a high value of transport critical current density (J c) exceeding 100 kAcm‑2 at T = 4.2 K and the self-field. Transport J c in the HIP wire reached 38 kAcm‑2 in a high magnetic field of 100 kOe. This value is almost twice larger than the previous highest value of J c among round wires using iron-based superconductors. Enhancement of J c in the wires and tapes was caused by improvement of the drawing process, which caused degradation of the core, formation of microcracks, weak links between grains, and random orientation of grains. Details of the effect of the improved fabrication processes on the J c are discussed.

On the search for the electric dipole moment of strange and charm baryons at LHC

NASA Astrophysics Data System (ADS)

Botella, F. J.; Garcia Martin, L. M.; Marangotto, D.; Martinez Vidal, F.; Merli, A.; Neri, N.; Oyanguren, A.; Ruiz Vidal, J.

2017-03-01

Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange Λ baryons, selected from weak decays of charm baryons produced in p p collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of CPT symmetry can be performed by measuring the magnetic dipole moment of Λ and \\overline{Λ} baryons. For short-lived {Λ} ^+c and {Ξ} ^+c baryons, to be produced in a fixed-target experiment using the 7 TeV LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed.

CATSI EDM: recent advances in the development and validation of a ruggedized passive standoff CWA sensor

NASA Astrophysics Data System (ADS)

Lavoie, Hugo; Thériault, Jean-Marc; Bouffard, François; Puckrin, Eldon; Turcotte, Caroline S.; Lacasse, Paul

2008-04-01

Defence Research and Development Canada (DRDC) - Valcartier is currently developing a ruggedized passive standoff sensor for the detection of chemical warfare agents (CWAs) based on differential Fourier-transform infrared (FTIR) radiometry. This system is referred to as the Compact ATmospheric Sounding Interferometer (CATSI) Engineering Development Model (EDM). The CATSI EDM sensor is based on the use of a double-beam FTIR spectrometer that is optimized for optical subtraction. A description of the customized sensor is given along with a discussion on the detection and identification approaches that have been developed. Preliminary results of validation from a number of laboratory measurements and open-air trials are analyzed to establish the capability of detection and identification of various toxic and non-toxic chemical vapor plumes. These results clearly demonstrate the capability of the passive differential radiometric approach for the standoff detection and identification of chemical vapors at distances up to a few kilometers from the sensor.

Feasibility of Harvesting Radon from FRIB Beam Dump

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

Visser, A.; Scielzo, N.

The observation of a permanent electric dipole moment (EDM) in an atom would signal a long-soughtafter presence of time-reversal violation and would have far reaching consequences for both particle physics and cosmology. Currently, the most stringent limitation on time-reversal violating effects in the nucleus comes from studies of stable 199Hg. However, for certain nuclei which have an octupole deformed shape, such as 223Rn, the time-reversal violating interactions are expected to be 100-1000 times greater than in 199Hg (Auerbach et al. 1996). As a result, there is great interest in searching for EDMs in octupole deformed nuclei and some of themore » initial studies of these nuclei have been featured on the cover of the journal Nature (Gaffney et al. 2013). All the octupole deformed nuclei of interest are radioactive and therefore available only in limited quantities. The primary challenge for an EDM experiment using radon is to collect large enough samples to perform sensitive searches.« less

Reduced Limit on the Permanent Electric Dipole Moment of ^{199}Hg.

PubMed

Graner, B; Chen, Y; Lindahl, E G; Heckel, B R

2016-04-22

This Letter describes the results of the most recent measurement of the permanent electric dipole moment (EDM) of neutral ^{199}Hg atoms. Fused silica vapor cells containing enriched ^{199}Hg are arranged in a stack in a common magnetic field. Optical pumping is used to spin polarize the atoms orthogonal to the applied magnetic field, and the Faraday rotation of near-resonant light is observed to determine an electric-field-induced perturbation to the Larmor precession frequency. Our results for this frequency shift are consistent with zero; we find the corresponding ^{199}Hg EDM d_{Hg}=(-2.20±2.75_{stat}±1.48_{syst})×10^{-30}e cm. We use this result to place a new upper limit on the ^{199}Hg EDM |d_{Hg}|<7.4×10^{-30}e cm (95% C.L.), improving our previous limit by a factor of 4. We also discuss the implications of this result for various CP-violating observables as they relate to theories of physics beyond the standard model.

Magnetic Field Monitoring in the SNS and LANL Neutron EDM Experiments

NASA Astrophysics Data System (ADS)

Aleksandrova, Alina; SNS nEDM Collaboration; LANL nEDM Collaboration

2017-09-01

The SNS neutron EDM experiment requires the ability to precisely control and monitor the magnetic field inside of the fiducial volume. However, it is not always practical (or even possible) to measure the field within the region of interest directly. To remedy this issue, we have designed a field monitoring system that will allow us to reconstruct the field inside of the fiducial volume using noninvasive measurements of the field components at discrete locations external to this volume. A prototype probe array (consisting of 12 single-axis fluxgate magnetometer sensors) was used to monitor the magnetic field within the fiducial volume of an in-house magnetic testing apparatus. In this talk, the design and results of this test will be presented, and the possible implementation of this field monitoring method may have in the room temperature LANL neutron EDM experiment will be discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Award Number DE-SC-0014622.

Replicative DNA polymerase mutations in cancer☆

PubMed Central

Heitzer, Ellen; Tomlinson, Ian

2014-01-01

Three DNA polymerases — Pol α, Pol δ and Pol ɛ — are essential for DNA replication. After initiation of DNA synthesis by Pol α, Pol δ or Pol ɛ take over on the lagging and leading strand respectively. Pol δ and Pol ɛ perform the bulk of replication with very high fidelity, which is ensured by Watson–Crick base pairing and 3′exonuclease (proofreading) activity. Yeast models have shown that mutations in the exonuclease domain of Pol δ and Pol ɛ homologues can cause a mutator phenotype. Recently, we identified germline exonuclease domain mutations (EDMs) in human POLD1 and POLE that predispose to ‘polymerase proofreading associated polyposis’ (PPAP), a disease characterised by multiple colorectal adenomas and carcinoma, with high penetrance and dominant inheritance. Moreover, somatic EDMs in POLE have also been found in sporadic colorectal and endometrial cancers. Tumors with EDMs are microsatellite stable and show an ‘ultramutator’ phenotype, with a dramatic increase in base substitutions. PMID:24583393

Cancellations Between Two-Loop Contributions to the Electron Electric Dipole Moment with a CP-Violating Higgs Sector.

PubMed

Bian, Ligong; Liu, Tao; Shu, Jing

2015-07-10

We present a class of cancellation conditions for suppressing the total contributions of Barr-Zee diagrams to the electron electric dipole moment (eEDM). Such a cancellation is of particular significance after the new eEDM upper limit was released by the ACME Collaboration, which strongly constrains the allowed magnitude of CP violation in Higgs couplings and hence the feasibility of electroweak baryogenesis (EWBG). Explicitly, if both the CP-odd Higgs-photon-photon (Z boson) and the CP-odd Higgs-electron-positron couplings are turned on, a cancellation may occur either between the contributions of a CP-mixing Higgs boson, with the other Higgs bosons being decoupled, or between the contributions of CP-even and CP-odd Higgs bosons. With a cancellation, large CP violation in the Higgs sector is still allowed, yielding successful EWBG. The reopened parameter regions would be probed by future neutron, mercury EDM measurements, and direct measurements of Higgs CP properties at the Large Hadron Collider Run II and future colliders.

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.

Strain accumulation in the Shumagin Islands: Results of initial GPS measurements

USGS Publications Warehouse

Larson, Kristine M.; Lisowski, Michael

1994-01-01

Deformation in the Shumagin seismic gap has been monitored with repeated trilateration (EDM) in the 1980–1987 interval and with the Global Positioning System (GPS) in the 1987–1991 interval. The geodetic network extends for 100-km across the Shumagin Islands to the Alaska Peninsula. Results from the GPS surveys are consistent with those previously reported for the EDM surveys: we failed to detect significant strain accumulation in the N30°W direction of plate convergence. Using the method of simultaneous reduction for position and strain rates, we found the average rate of extension in the direction of plate convergence to be −25±25 nanostrain/yr (nstrain/yr) during the 1987–1991 interval of GPS surveys compared with −20±15 nstrain/yr during the 1981–1987 interval of complete EDM surveys. We found a marginally significant −26±12 nstrain/yr extension rate in the 1981–1991 interval covered by the combined EDM and GPS surveys. Strain rates are higher, but not significantly so, in the part of the network closest to the trench. Spatial variation in the deformation is observed in the 1980–1991 average station velocities, where three of the four stations closest to the trench have an arcward velocity of a few mm/yr. The observed strain rates are an order of magnitude lower than the −200 nstrain/yr rate predicted by dislocation models.

Equation-free mechanistic ecosystem forecasting using empirical dynamic modeling

PubMed Central

Ye, Hao; Beamish, Richard J.; Glaser, Sarah M.; Grant, Sue C. H.; Hsieh, Chih-hao; Richards, Laura J.; Schnute, Jon T.; Sugihara, George

2015-01-01

It is well known that current equilibrium-based models fall short as predictive descriptions of natural ecosystems, and particularly of fisheries systems that exhibit nonlinear dynamics. For example, model parameters assumed to be fixed constants may actually vary in time, models may fit well to existing data but lack out-of-sample predictive skill, and key driving variables may be misidentified due to transient (mirage) correlations that are common in nonlinear systems. With these frailties, it is somewhat surprising that static equilibrium models continue to be widely used. Here, we examine empirical dynamic modeling (EDM) as an alternative to imposed model equations and that accommodates both nonequilibrium dynamics and nonlinearity. Using time series from nine stocks of sockeye salmon (Oncorhynchus nerka) from the Fraser River system in British Columbia, Canada, we perform, for the the first time to our knowledge, real-data comparison of contemporary fisheries models with equivalent EDM formulations that explicitly use spawning stock and environmental variables to forecast recruitment. We find that EDM models produce more accurate and precise forecasts, and unlike extensions of the classic Ricker spawner–recruit equation, they show significant improvements when environmental factors are included. Our analysis demonstrates the strategic utility of EDM for incorporating environmental influences into fisheries forecasts and, more generally, for providing insight into how environmental factors can operate in forecast models, thus paving the way for equation-free mechanistic forecasting to be applied in management contexts. PMID:25733874

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.

Fabrication of Pd-Cr wire

NASA Technical Reports Server (NTRS)

Diamond, Sidney; Leach, Dennen M.

1989-01-01

Fabrication of Pd-13 percent Cr alloy wires is described. Melting, casting, swaging and annealing processes are discussed. Drawing to reach two diameters (0.003 inch and 0.00176 inch) of wire is described. Representative micrographs of the Pd-Cr alloy at selected stages during wire fabrication are included. The resistance of the wire was somewhat lower, by about 15 to 20 percent, than comparable wire of other alloys used for strain gages.

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

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.

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.

The ExoMars 2016 Mission arriving at Mars

NASA Astrophysics Data System (ADS)

Svedhem, H.; Vago, J. L.

2016-12-01

The ExoMars 2016 mission was launched on a Proton rocket from Baikonur, Kazakhstan, on 14 March 2016 and is scheduled to arrive at Mars on 19 October 2016. ExoMars is a joint programme of the European Space Agency (ESA) and Roscosmos, Russia. It consists of the ExoMars 2016 mission with the Trace Gas Orbiter, TGO, and the Entry Descent and Landing Demonstrator, EDM, named Schiaparelli, and the ExoMars 2020 mission, which carries a lander and a rover. The TGO scientific payload consists of four instruments. These are: ACS and NOMAD, both infrared spectrometers for atmospheric measurements in solar occultation mode and in nadir mode, CASSIS, a multichannel camera with stereo imaging capability, and FREND, an epithermal neutron detector to search for subsurface hydrogen (as proxy for water ice and hydrated minerals). The mass of the TGO is 3700 kg, including fuel. The EDM, with a mass of 600 kg, is mounted on top of the TGO as seen in its launch configuration. The EDM is carried to Mars by the TGO and is separated three days before arrival at Mars. In addition to demonstrating the landing capability two scientific investigations are included with the EDM. The AMELIA investigation aims at characterising the Martian atmosphere during the entry and descent using technical and engineering sensors of the EDM, and the DREAMS suite of sensors that will characterise the environment of the landing site for a few days after the landing. ESA provides the TGO spacecraft and the Schiaparelli Lander demonstrator, ESA member states provide two of the TGO instruments and Roscosmos provides the launcher and the other two TGO instruments. After the arrival of the ExoMars 2020 mission at the surface of Mars, the TGO will handle all communications between the Earth and the Rover. The communication between TGO and the rover/lander is done through a UHF communications system, a contribution from NASA. This presentation will cover a description of the 2016 mission, including the spacecraft, its payload and science and the related plans for scientific operations and measurements, a summary of the activities since arrival, and, if available, some first results of the mission.

Deformation of the Long Valley Caldera, California: Inferences from measurements from 1988 to 2001

USGS Publications Warehouse

Langbein, J.O.

2003-01-01

Two periods of volcanic unrest occurred between 1989 and 1998 in the Long Valley Caldera, eastern California. Numerous earthquakes were recorded, and these periods of unrest were documented with high-precision geodetic measurements. The first round of unrest started rapidly in late 1989 and slowly decreased in rate through the early 1990s. For this interval there are both leveling and two-color electronic distance meter (EDM) measurements. The second round of unrest started slowly in mid-1997, climaxed in late 1997, and rapidly returned to quiescence by mid-1998. Deformation was recorded by both the two-color EDM and continuous GPS. Both episodes require inflation at 6-7 km beneath the resurgent dome, and both episodes had roughly 0.1 m extension across the resurgent dome. In addition, the data presented here suggest that there is a deeper, 10-20 km, inflation source beneath the south moat of the caldera. For both episodes, the better-resolved inflation beneath the resurgent dome is a near-vertical, prolate spheroid rather than an isotropic source, which suggests that magma came up through vertical cracks. However, the modeling suggests that the location changed with the depth from 6.0 to 6.7 km for the later episode. In contrast to the earlier episode, the 1997-1998 episode has additional deformation in the south moat, where the simplest model is that of a right-lateral slip on a steeply dipping plane that is defined by the location of earthquakes in the south moat. Models of the time-dependent behavior suggest that slip on this fault occurred from late November through December 1997, corresponding to the time of greatest moment release by the earthquake swarm in the south moat. Confounding the interpretation of these data is an active geothermal field near the center of the EDM network and adjacent to the south moat and resurgent dome. Additional modeling of leveling and EDM data within the geothermal field during a period of low rate of inflation of the dome suggests some methods of adjustments to the EDM data during the inflation episodes. ?? 2003 Elsevier B.V. All rights reserved.

ExoMars 2016 Status and Future Plans

NASA Astrophysics Data System (ADS)

Svedhem, Håkan; Vago, Jorge

2017-04-01

The ExoMars programme is a joint activity by the European Space Agency(ESA) and ROSCOSMOS, Russia. It consists of the ExoMars 2016 mission, launched 14 March 2016, with the Trace Gas Orbiter, TGO, and the Entry Descent and Landing Demonstrator, EDM, named Schiaparelli, and the ExoMars 2020 mission, to be launched in May 2020, carrying a lander and a rover. TGO and EDM arrived at Mars on 19 October 2016. After a nominal entry and first phase of the descent, the EDM failed at an altitude of about 4 km and fell freely to the surface, near the centre of the landing ellipse in Meridiani Planum. The communication link was maintain up until the failure and a large data set was acquired, allowing for a complete analysis of the first successful part of the mission, and an investigation of the on board anomaly leading to the failure. The TGO spacecraft was inserted into a highly elliptical 4 sol period, near equatorial, capture orbit. Two orbits in late November were dedicated to instrument calibration and initial science observations, where an excellent performance of all instruments could be confirmed. In January 2017 the orbital plane will be changed to its final inclination of 74 degrees and the period will be reduced to one Sol. Early March two orbits are scheduled for another set of instrument observations, after which a long period of aerobraking will commence. The final operational orbit, with a 2 hour period, is expected to be reached early 2018. The TGO scientific payload consists of four instruments. These are: ACS and NOMAD, both infrared spectrometers for atmospheric measurements in solar occultation mode and in nadir mode, CASSIS, a multichannel camera with stereo imaging capability, and FREND, an epithermal neutron detector for search of subsurface hydrogen. The mass of the TGO is 3700 kg, including fuel and the mass of EDM was 600 kg. The EDM was carried to Mars by the TGO and was separated three days before arrival at Mars. This presentation will cover a brief description of the 2016 mission, results from the initial phase since arrival, present status, and future activities.

DNA polymerase ɛ and δ exonuclease domain mutations in endometrial cancer

PubMed Central

Church, David N.; Briggs, Sarah E.W.; Palles, Claire; Domingo, Enric; Kearsey, Stephen J.; Grimes, Jonathon M.; Gorman, Maggie; Martin, Lynn; Howarth, Kimberley M.; Hodgson, Shirley V.; Kaur, Kulvinder; Taylor, Jenny; Tomlinson, Ian P.M.

2013-01-01

Accurate duplication of DNA prior to cell division is essential to suppress mutagenesis and tumour development. The high fidelity of eukaryotic DNA replication is due to a combination of accurate incorporation of nucleotides into the nascent DNA strand by DNA polymerases, the recognition and removal of mispaired nucleotides (proofreading) by the exonuclease activity of DNA polymerases δ and ɛ, and post-replication surveillance and repair of newly synthesized DNA by the mismatch repair (MMR) apparatus. While the contribution of defective MMR to neoplasia is well recognized, evidence that faulty DNA polymerase activity is important in cancer development has been limited. We have recently shown that germline POLE and POLD1 exonuclease domain mutations (EDMs) predispose to colorectal cancer (CRC) and, in the latter case, to endometrial cancer (EC). Somatic POLE mutations also occur in 5–10% of sporadic CRCs and underlie a hypermutator, microsatellite-stable molecular phenotype. We hypothesized that sporadic ECs might also acquire somatic POLE and/or POLD1 mutations. Here, we have found that missense POLE EDMs with good evidence of pathogenic effects are present in 7% of a set of 173 endometrial cancers, although POLD1 EDMs are uncommon. The POLE mutations localized to highly conserved residues and were strongly predicted to affect proofreading. Consistent with this, POLE-mutant tumours were hypermutated, with a high frequency of base substitutions, and an especially large relative excess of G:C>T:A transversions. All POLE EDM tumours were microsatellite stable, suggesting that defects in either DNA proofreading or MMR provide alternative mechanisms to achieve genomic instability and tumourigenesis. PMID:23528559

Cyclic fatigue resistances of several nickel-titanium glide path rotary and reciprocating instruments at body temperature.

PubMed

Yılmaz, K; Uslu, G; Gündoğar, M; Özyürek, T; Grande, N M; Plotino, G

2018-01-31

To compare the cyclic fatigue resistance of the One G, ProGlider, HyFlex EDM and R-Pilot glide path NiTi files at body temperature. Twenty One G (size 14, .03 taper), 20 ProGlider (size 16, .02 taper), 20 HyFlex EDM (size 10, .05 taper) and 20 R-Pilot (size 12.5, .04 taper) instruments were operated in rotation at 300 rpm (One G, ProGlider and HyFlex) or in reciprocation (R-Pilot) at 35 °C in artificial canals that were manufactured by reproducing the size and taper of the instrument until fracture occurred. The time to fracture was recorded in seconds using a digital chronometer, and the length of the fractured fragments was registered. Mean data were analysed statistically using the Kruskal-Wallis test and post hoc Tukey tests via SPSS 21.0 software. The statistical significance level was set at 5%. The cyclic fatigue resistance of the R-Pilot files was significantly greater than the other instruments, and the One G was significantly lower (P < 0.05). There was no difference between the HyFlex EDM and the ProGlider (P > 0.05). No significant difference (P > 0.05) was evident in the mean length of the fractured fragments of the various instruments. The cyclic fatigue resistance of the R-Pilot reciprocating glide path file was significantly greater than that of the rotary HyFlex EDM, ProGlider and One G glide path files. © 2018 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Fabrication of compact electron gun for 6 MeV X-ray source

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

Ghodke, S.R.; Barnwal, Rajesh; Kumar, Mahendra, E-mail: ghodke_barc@yahoo.co.in

The 6 MeV X-Ray source for container cargo scanning application has been designed and developed by the Accelerator and Pulse Power Division, BARC, Mumbai. This compact linac has been designed as a mobile system, to be mounted on a moving container. In linac-based cargo-scanning system, to work electron gun on a movable container, it has to be robust. Electron gun is to work at 10{sup -7} mbar vacuum and 2000 degree Celsius temperature. An effort is made to engineer the gun assembly to make it more robust and aligned. The linac acts as the source of X-rays, which fall onmore » the cargo and are then detected by the detector system. Many components are indigenously developed like grid, insulating ring, Tungsten filament and filament guide, which are made from alumina ceramic and Tantalum which is to work at 1500 degree Celsius. Filament connector is made from Invar to reduce heat loss and to make rigid connection. It was CNC machined and wire cut by EDM. Invar and Copper electrode feed through is shrink fitted with the help of liquid Nitrogen. Shrink fit tolerances of 15 micrometer are achieved by jig boring machining processes. Tantalum cup for LaB6 cathode and heat shield are made from die and punch mechanism. For alignment of electron emitter with beam axis this Tantalum cup is a crucial component. Electron gun is assembled and aligned its components with the help of precision jigs. The whole assembly was Helium leak tested by MSLD up to 4 x 10{sup -10} mbar.l/s vacuum, no leak was found. This paper will describe the machining, Tantalum cup forming, ceramic components development, heat shields, ceramic feed through etc of electron gun. (author)« less

Continuous feed, on-site composting of kitchen garbage.

PubMed

Hwang, Eung-Ju; Shin, Hang-Sik; Tay, Joo-Hwa

2002-04-01

Kitchen garbage generated at a school cafeteria was treated and stabilised in a controlled on-site composting unit for volume reduction and on-site utilisation of processed garbage. The on-site composter was fed with the garbage on a daily basis during the two-months experimental period. Compost was not removed from the unit but was entirely reused as a bulking agent in order to minimise the need for additional bulking agent and compost handling. Performance of the composter tinder this condition was investigated. Most of the easily degradable organic matter (EDM) in the garbage was biodegraded rapidly, and the final product had a low content of EDM. Lipids, total sugar, and hemi-cellulose were degraded 96%, 81%, and 66% respectively. Free air space (FAS) was higher than 0.5 all the time, so accumulation of dry matter in the unit was not significant in reducing reaction efficiency. Other reaction parameters such as pH and MC were kept within a suitable range; however, it was advisable to maintain MC at over 46%. As a result, this method of operation was able to stabilise the garbage with low sawdust demand and little compost production.

Geometry and surface damage in micro electrical discharge machining of micro-holes

NASA Astrophysics Data System (ADS)

Ekmekci, Bülent; Sayar, Atakan; Tecelli Öpöz, Tahsin; Erden, Abdulkadir

2009-10-01

Geometry and subsurface damage of blind micro-holes produced by micro electrical discharge machining (micro-EDM) is investigated experimentally to explore the relational dependence with respect to pulse energy. For this purpose, micro-holes are machined with various pulse energies on plastic mold steel samples using a tungsten carbide tool electrode and a hydrocarbon-based dielectric liquid. Variations in the micro-hole geometry, micro-hole depth and over-cut in micro-hole diameter are measured. Then, unconventional etching agents are applied on the cross sections to examine micro structural alterations within the substrate. It is observed that the heat-damaged segment is composed of three distinctive layers, which have relatively high thicknesses and vary noticeably with respect to the drilling depth. Crack formation is identified on some sections of the micro-holes even by utilizing low pulse energies during machining. It is concluded that the cracking mechanism is different from cracks encountered on the surfaces when machining is performed by using the conventional EDM process. Moreover, an electrically conductive bridge between work material and debris particles is possible at the end tip during machining which leads to electric discharges between the piled segments of debris particles and the tool electrode during discharging.

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.

Low energy probes of PeV scale sfermions

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

Altmannshofer, Wolfgang; Harnik, Roni; Zupan, Jure

2013-11-27

We derive bounds on squark and slepton masses in mini-split supersymmetry scenario using low energy experiments. In this setup gauginos are at the TeV scale, while sfermions are heavier by a loop factor. We cover the most sensitive low energy probes including electric dipole moments (EDMs), meson oscillations and charged lepton flavor violation (LFV) transitions. A leading log resummation of the large logs of gluino to sfermion mass ratio is performed. A sensitivity to PeV squark masses is obtained at present from kaon mixing measurements. A number of observables, including neutron EDMs, mu->e transitions and charmed meson mixing, will startmore » probing sfermion masses in the 100 TeV-1000 TeV range with the projected improvements in the experimental sensitivities. We also discuss the implications of our results for a variety of models that address the flavor hierarchy of quarks and leptons. We find that EDM searches will be a robust probe of models in which fermion masses are generated radiatively, while LFV searches remain sensitive to simple-texture based flavor models.« less

Calculation of the atomic electric dipole moment of Pb2+ induced by nuclear Schiff moment

NASA Astrophysics Data System (ADS)

Ramachandran, S. M.; Latha, K. V. P.; Meenakshisundaram, N.

2017-07-01

We report the atomic electric dipole moment induced by the P, T violating interactions in the nuclear/sub-nuclear level, for 207Pb2+ and 207Pb, owing to the recent interest in the ferroelectric crystal PbTiO3 as one of the candidates for investigating macroscopic P, T-odd effects. In this paper, we calculate the atomic electric dipole moments of 207Pb and Pb2+, parametrized in terms of the P, T-odd coupling parameter, the nuclear Schiff moment (NSM), S, in the frame-work of the coupled-perturbed Hartree-Fock theory. We estimate the Schiff moment of Pb2+ using the experimental result of a system, which is electronically similar to the Pb2+ ion. We present the dominant contributions of the electric dipole moment (EDM) matrix elements and the important correlation effects contributing to the atomic EDM of Pb2+. Our results provide the first ever calculated EDM of the Pb2+ ion, and an estimate of its NSM from which the P, T-odd energy shift in a PbTiO3 crystal can be evaluated.

Tilt networks of Mount Shasta and Lassen Peak, California

USGS Publications Warehouse

Dzurisin, Daniel; Johnson, Daniel J.; Murray, T.L.; Myers, Barbara

1982-01-01

In response to recent eruptions at Mount St. Helens and with support from the USGS Volcanic Hazards Program, the Cascades Volcano Observatory (CVO) has initiated a program to monitor all potentially-active volcanoes of the Cascade Range. As part of that effort, we installed tilt networks and obtained baseline measurements at Mount Shasta and Lassen Peak, California during July 1981. At the same time, baseline electronic distance measurements (EDM) were made and fumarole surveys were conducted by other crews from CVO. Annual surveys are planned initially, with subsequent visits as conditions warrant. These geodetic and geochemical measurements supplement a program of continuous seismic monitoring of Cascade volcanoes by the USGS Office of Earthquake Studies in cooperation with local universities. Other tilt networks were established at Mount Baker in 1975 and at Mount St. Helens in 1981. EDM networks were established at Mount Baker in 1975, Mount St. Helens in 1980, and Crater Lake in 1981. Additional tilt and/or EDM networks are planned for Mount Rainier, Mount Hood, Glacier Peak, Three Sisters, and Crater Lake as funds permit.

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 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.

Enabling Open Science for Health Research: Collaborative Informatics Environment for Learning on Health Outcomes (CIELO).

PubMed

Payne, Philip; Lele, Omkar; Johnson, Beth; Holve, Erin

2017-07-31

There is an emergent and intensive dialogue in the United States with regard to the accessibility, reproducibility, and rigor of health research. This discussion is also closely aligned with the need to identify sustainable ways to expand the national research enterprise and to generate actionable results that can be applied to improve the nation's health. The principles and practices of Open Science offer a promising path to address both goals by facilitating (1) increased transparency of data and methods, which promotes research reproducibility and rigor; and (2) cumulative efficiencies wherein research tools and the output of research are combined to accelerate the delivery of new knowledge in proximal domains, thereby resulting in greater productivity and a reduction in redundant research investments. AcademyHealth's Electronic Data Methods (EDM) Forum implemented a proof-of-concept open science platform for health research called the Collaborative Informatics Environment for Learning on Health Outcomes (CIELO). The EDM Forum conducted a user-centered design process to elucidate important and high-level requirements for creating and sustaining an open science paradigm. By implementing CIELO and engaging a variety of potential users in its public beta testing, the EDM Forum has been able to elucidate a broad range of stakeholder needs and requirements related to the use of an open science platform focused on health research in a variety of "real world" settings. Our initial design and development experience over the course of the CIELO project has provided the basis for a vigorous dialogue between stakeholder community members regarding the capabilities that will add the greatest value to an open science platform for the health research community. A number of important questions around user incentives, sustainability, and scalability will require further community dialogue and agreement. ©Philip Payne, Omkar Lele, Beth Johnson, Erin Holve. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 31.07.2017.

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.

Manufacturing Process Development to Produce Depleted Uranium Wire for EBAM Feedstock

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

Alexander, David John; Clarke, Kester Diederik; Coughlin, Daniel Robert

2015-06-30

Wire produced from depleted uranium (DU) is needed as feedstock for the Electron-Beam Additive Manufacturing (EBAM) process. The goal is to produce long lengths of DU wire with round or rectangular cross section, nominally 1.5 mm (0.060 inches). It was found that rolling methods, rather than swaging or drawing, are preferable for production of intermediate quantities of DU wire. Trials with grooveless rolling have shown that it is suitable for initial reductions of large stock. Initial trials with grooved rolling have been successful, for certain materials. Modified square grooves (square round-bottom vee grooves) with 12.5 % reduction of area permore » pass have been selected for the reduction process.« less

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.

Update on CERN Search based on SharePoint 2013

NASA Astrophysics Data System (ADS)

Alvarez, E.; Fernandez, S.; Lossent, A.; Posada, I.; Silva, B.; Wagner, A.

2017-10-01

CERN’s enterprise Search solution “CERN Search” provides a central search solution for users and CERN service providers. A total of about 20 million public and protected documents from a wide range of document collections is indexed, including Indico, TWiki, Drupal, SharePoint, JACOW, E-group archives, EDMS, and CERN Web pages. In spring 2015, CERN Search was migrated to a new infrastructure based on SharePoint 2013. In the context of this upgrade, the document pre-processing and indexing process was redesigned and generalised. The new data feeding framework allows to profit from new functionality and it facilitates the long term maintenance of the system.

Nonmedical opioid use among electronic dance music party attendees in New York City.

PubMed

Palamar, Joseph J; Le, Austin; Cleland, Charles M

2018-05-01

Nonmedical opioid use remains an epidemic in the United States. Electronic dance music (EDM) party attendees have been found to be at high risk for the use of drugs such as ecstasy, but little is known about nonmedical opioid use in this population. Using time-space sampling, we surveyed 954 individuals (ages 18-40) attending randomly selected EDM parties in New York City in 2017. Participants were asked about the use of 18 different opioids and about willingness to use if offered by a friend in the next 30 days. We estimated the prevalence of use in this population and examined correlates of past-year and past-month use. Almost a quarter (23.9%) of EDM party attendees are estimated to have used opioids non-medically in their lifetime, and one out of ten (9.8%) in the past year. 5% are estimated to be current users (reporting past-month use), and 16.4% are willing to use opioids non-medically if offered by a friend in the next 30 days. Past-year nonmedical benzodiazepine users were at high odds for reporting current nonmedical opioid use (aOR = 10.11, p < 0.001) and, on average, report using more different opioid drugs in the past year than non-past-year-users (p = 0.012). Nearly three-quarters (73.6%) of those who have used in the past year indicated that they would use again if offered by a friend in the next 30 days. Nonmedical opioid use is prevalent in the EDM scene and many attendees are willing to use if offered. Prevention efforts are needed in this high-risk population. Copyright © 2018 Elsevier B.V. All rights reserved.

Polysubstance use profiles among electronic dance music party attendees in New York City and their relation to use of new psychoactive substances.

PubMed

Fernández-Calderón, Fermín; Cleland, Charles M; Palamar, Joseph J

2018-03-01

Electronic Dance Music (EDM) party attendees are often polysubstance users and are at high risk for use of new psychoactive substances (NPS). We sought to identify patterns of use of common illegal drugs among EDM party attendees, sociodemographic correlates, and use of NPS as a function of patterns of use of more common drugs to inform prevention and harm reduction. Using time-space-sampling, 1045 individuals aged 18-40 were surveyed entering EDM parties in New York City. We queried past-year use of common illegal drugs and 98 NPS. We conducted latent class analysis to identify polysubstance use profiles of use of eight common drugs (i.e., ecstasy, ketamine, LSD, mushrooms, powder cocaine, marijuana, amphetamine, benzodiazepines). Relationships between drug classification membership and sociodemographics and use of drugs within six NPS categories were examined. We identified four profiles of use of common drugs: non-polysubstance use (61.1%), extensive polysubstance use (19.2%), moderate polysubstance use/stimulants (12.8%), and moderate polysubstance use/psychedelics (6.7%). Those in the moderate/psychedelic group were at higher odds of using NPS with psychedelic-type effects (2C, tryptamines, and other "new" psychedelics; Ps<0.05). Extensive polysubstance users were at increased odds of reporting use of 2C drugs, synthetic cathinones ("bath salts"), tryptamines, other new (non-phenethylamine) psychedelics, new dissociatives, and synthetic cannabinoids (Ps<0.05). NPS preference is linked to the profile of use of common drugs among individuals in the EDM scene. Most participants were identified as non-polysubstance users, but findings may help inform preventive and harm reduction interventions among those at risk in this scene. Copyright © 2017 Elsevier Ltd. All rights reserved.

Method of manufacturing superconductor wire

DOEpatents

Motowidlo, Leszek

2014-09-16

A method for forming Nb.sub.3Sn superconducting wire is provided. The method employs a powder-in-tube process using a high-tin intermetallic compound, such as MnSn.sub.2, for producing the Nb.sub.3Sn. The use of a high-tin intermetallic compound enables the process to perform hot extrusion without melting the high-tin intermetallic compound. Alternatively, the method may entail drawing the wire without hot extrusion.

Process for producing fine and ultrafine filament superconductor wire

DOEpatents

Kanithi, H.C.

1992-02-18

A process for producing a superconductor wire made up of a large number of round monofilament rods is provided for, comprising assembling a multiplicity of round monofilaments inside each of a multiplicity of thin wall hexagonal tubes and then assembling a number of said thin wall hexagonal tubes within an extrusion can and subsequently consolidating, extruding and drawing the entire assembly down to the desired wire size. 8 figs.

Process for producing fine and ultrafine filament superconductor wire

DOEpatents

Kanithi, Hem C.

1992-01-01

A process for producing a superconductor wire made up of a large number of round monofilament rods is provided for, comprising assembling a multiplicity of round monofilaments inside each of a multiplicity of thin wall hexagonal tubes and then assembling a number of said thin wall hexagonal tubes within an extrusion can and subsequently consolidating, extruding and drawing the entire assembly down to the desired wire size.

Theoretical models of the electrical discharge machining process. III. The variable mass, cylindrical plasma model

NASA Astrophysics Data System (ADS)

Eubank, Philip T.; Patel, Mukund R.; Barrufet, Maria A.; Bozkurt, Bedri

1993-06-01

A variable mass, cylindrical plasma model (VMCPM) is developed for sparks created by electrical discharge in a liquid media. The model consist of three differential equations—one each from fluid dynamics, an energy balance, and the radiation equation—combined with a plasma equation of state. A thermophysical property subroutine allows realistic estimation of plasma enthalpy, mass density, and particle fractions by inclusion of the heats of dissociation and ionization for a plasma created from deionized water. Problems with the zero-time boundary conditions are overcome by an electron balance procedure. Numerical solution of the model provides plasma radius, temperature, pressure, and mass as a function of pulse time for fixed current, electrode gap, and power fraction remaining in the plasma. Moderately high temperatures (≳5000 K) and pressures (≳4 bar) persist in the sparks even after long pulse times (to ˜500 μs). Quantitative proof that superheating is the dominant mechanism for electrical discharge machining (EDM) erosion is thus provided for the first time. Some quantitative inconsistencies developed between our (1) cathode, (2) anode, and (3) plasma models (this series) are discussed with indication as to how they will be rectified in a fourth article to follow shortly in this journal. While containing oversimplifications, these three models are believed to contain the respective dominant physics of the EDM process but need be brought into numerical consistency for each time increment of the numerical solution.

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.

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.

Team-Based Learning Instruction for Responsible Conduct of Research Positively Impacts Ethical Decision-Making

PubMed Central

McCormack, Wayne T.; Garvan, Cynthia W.

2013-01-01

Common practices for responsible conduct of research (RCR) instruction have recently been shown to have no positive impact on and possibly to undermine ethical decision-making (EDM). We show that a team-based learning (TBL) RCR curriculum results in some gains in decision ethicality, the use of more helpful meta-cognitive reasoning strategies in decision-making, and elimination of most negative effects of other forms of RCR instruction on social–behavioral responses. TBL supports the reasoning strategies and social mechanisms that underlie EDM and ethics instruction, and may provide a more effective method for RCR instruction than lectures and small group discussion. PMID:24073606

Effective field theory, electric dipole moments and electroweak baryogenesis

NASA Astrophysics Data System (ADS)

Balazs, Csaba; White, Graham; Yue, Jason

2017-03-01

Negative searches for permanent electric dipole moments (EDMs) heavily constrain models of baryogenesis utilising various higher dimensional charge and parity violating (CPV) operators. Using effective field theory, we create a model independent connection between these EDM constraints and the baryon asymmetry of the universe (BAU) produced during a strongly first order electroweak phase transition. The thermal aspects of the high scale physics driving the phase transition are paramaterised by the usual kink solution for the bubble wall profile. We find that operators involving derivatives of the Higgs field yield CPV contributions to the BAU containing derivatives of the Higgs vacuum expectation value (vev), while non-derivative operators lack such contributions. Consequently, derivative operators cannot be eliminated in terms of non-derivative operators (via the equations of motion) if one is agnostic to the new physics that leads to the phase transition. Thus, we re-classify the independent dimension six operators, restricting ourselves to third generation quarks, gauge bosons and the Higgs. Finally, we calculate the BAU (as a function of the bubble wall width and the cutoff) for a derivative and a non-derivative operator, and relate it to the EDM constraints.

Compatibility of photomultiplier tube operation with SQUIDs for a neutron EDM experiment

NASA Astrophysics Data System (ADS)

Libersky, Matthew; nEDM Collaboration

2013-10-01

An experiment at the Spallation Neutron Source at Oak Ridge National Laboratory with the goal of reducing the experimental limit on the electric dipole moment (EDM) of the neutron will measure the precession frequencies of neutrons when a strong electric field is applied parallel and anti-parallel to a weak magnetic field. A difference in these frequencies would indicate a nonzero neutron EDM. To correct for drifts of the magnetic field in the measurement volume, polarized 3He will be used as a co-magnetometer. In one of the two methods built into the apparatus, superconducting quantum interference devices (SQUIDs) will be used to read out the 3He magnetization. Photomultiplier tubes will be used concurrently to measure scintillation light from neutron capture by 3He. However, the simultaneous noise-sensitive magnetic field measurement by the SQUIDs makes conventional PMT operation problematic due to the alternating current involved in generating the high voltages needed. Tests were carried out at Los Alamos National Laboratory to study the compatibility of simultaneous SQUID and PMT operation, using a custom battery-powered high-voltage power supply developed by Meyer and Smith (NIM A 647.1) to operate the PMT. The results of these tests will be presented.

Minimizing Environmental Magnetic Field Sources for nEDM

NASA Astrophysics Data System (ADS)

Brinson, Alex; Filippone, Bradley; Slutsky, Simon; Osthelder, Charles

2017-09-01

Measurement of the neutron's Electric Dipole Moment (nEDM) could potentially explain the Baryon Asymmetry Problem, and would suggest plausible extensions to the Standard Model. We will attempt to detect the nEDM by measuring the electric-field-dependent neutron precession frequency, which is highly sensitive to magnetic field gradients. In order to produce fields with sufficiently low gradients for our experiment, we eliminate environmental effects by offsetting the ambient field with a Field Compensation System (FCS), then magnetically shielding the reduced field with a Mu-Metal cylinder. We discovered that the strongest environmental effect in our lab came from iron rebar embedded in the floor beneath the proposed experiment location. The large extent and strength of the floor's magnetization made the effect too large to offset with the FCS, forcing us to relocate our apparatus. The floor's magnetic field was mapped with a Hall probe in order to determine the most viable experiment locations. A 3-axis Fluxgate magnetometer was then used to determine the floor field's drop-off and shape at these locations, and a final apparatus position was determined which minimized the floor's effect such that it could be effectively offset and shielded by our experiment. Caltech SFP Office.

Strategies to Save 50% Site Energy in Grocery and General Merchandise Stores

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

Hirsch, A.; Hale, E.; Leach, M.

2011-03-01

This paper summarizes the methodology and main results of two recently published Technical Support Documents. These reports explore the feasibility of designing general merchandise and grocery stores that use half the energy of a minimally code-compliant building, as measured on a whole-building basis. We used an optimization algorithm to trace out a minimum cost curve and identify designs that satisfy the 50% energy savings goal. We started from baseline building energy use and progressed to more energy-efficient designs by sequentially adding energy design measures (EDMs). Certain EDMs figured prominently in reaching the 50% energy savings goal for both building types:more » (1) reduced lighting power density; (2) optimized area fraction and construction of view glass or skylights, or both, as part of a daylighting system tuned to 46.5 fc (500 lux); (3) reduced infiltration with a main entrance vestibule or an envelope air barrier, or both; and (4) energy recovery ventilators, especially in humid and cold climates. In grocery stores, the most effective EDM, which was chosen for all climates, was replacing baseline medium-temperature refrigerated cases with high-efficiency models that have doors.« less

Microcomputer pollution model for civilian airports and Air Force Bases. Model application and background

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

Segal, H.M.

1988-08-01

This is one of three reports describing the Emissions and Dispersion Modeling System (EDMS). All reports use the same main title--A MICROCOMPUTER MODEL FOR CIVILIAN AIRPORTS AND AIR FORCE BASES--but different subtitles. The subtitles are: (1) USER'S GUIDE - ISSUE 2 (FAA-EE-88-3/ESL-TR-88-54); (2) MODEL DESCRIPTION (FAA-EE-88-4/ESL-TR-88-53); (S) MODEL APPLICATION AND BACKGROUND (FAA-EE-88-5/ESL-TR-88-55). The first and second reports above describe the EDMS model and provide instructions for its use. This is the third report. IT consists of an accumulation of five key documents describing the development and use of the EDMS model. This report is prepared in accordance with discussions withmore » the EPA and requirements outlined in the March 27, 1980 Federal Register for submitting air-quality models to the EPA. Contents: Model Development and Use - Its Chronology and Reports; Monitoring Concorde EMissions; The Influence of Aircraft Operations on Air Quality at Airports; Simplex A - A simplified Atmospheric Dispersion Model for Airport Use -(User's Guide); Microcomputer Graphics in Atmospheric Dispersion Modeling; Pollution from Motor Vehicles and Aircraft at Stapleton International Airport (Abbreviated Report).« less

New Experiment to Measure the Electron Electric Dipole Moment

NASA Technical Reports Server (NTRS)

Kittle, Melanie

2003-01-01

An electron can possess an electric dipole moment (edm) only if time reversal symmetry (T) is violated. No edm of any particle has yet been discovered. CP-violation, equivalent to T-violation by the CPT theorem, does occur in Kaon decays and can be accounted for by the standard model. However, this mechanism leads to an electron edm d(sub e) of the order of 10(exp -38) e cm, whereas the current experimental bound on d(sub e) is about 10(exp -27) e cm. However, well-motivated extensions of the standard model such as supersymmetric theories do predict that de could be as large as the current bound. In addition, CP violation in the early universe is required to explain the preponderance of matter over anti-matter, but the exact mechanism of this CP violation is unclear. For these reasons, we are undertaking a new experimental program to determine de to an improved accuracy of 10(exp -29) e cm. Our experiment will use laser-cooled, trapped Cesium atoms to measure the atomic edm d(sub Cs) that occurs if d(sub e) is not zero. In order to do this, we will measure the energy splitting between the atoms spin states in parallel electric and magnetic fields. The signature of an edm would be a linear dependence of the splitting on the electric field E due to the interaction - d(sub Cs) dot E. Our measurement will be much more sensitive than previous measurements because atoms can be stored in the trap for tens of seconds, allowing for much narrower Zeeman resonance linewidths. Also, our method eliminates the most important systematic errors, proportional to atomic velocity, which have limited previous experiments. In this presentation, we will describe the design of our new apparatus, which is presently under construction. An important feature of our experimental apparatus is that magnetic field noise will be suppressed to a very low value of the order of 1 fT/(Hz)1/2. This requires careful attention to the Johnson noise currents in the chamber, which have not been important in previous experiments. In addition we will present estimates of the limits of the various errors that we expect for our experiment.

Scaling measurements of metabolism in stream ecosystems: challenges and approaches to estimating reaeration

NASA Astrophysics Data System (ADS)

Bowden, W. B.; Parker, S.; Song, C.

2016-12-01

Stream ecologists have used various formulations of an oxygen budget approach as a surrogate to measure "whole-stream metabolism" (WSM) of carbon in rivers and streams. Improvements in sensor technologies that provide reliable, high-frequency measurements of dissolved oxygen concentrations in adverse field conditions has made it much easier to acquire the basic data needed to estimate WSM in remote locations over long periods (weeks to months). However, accurate estimates of WSM require reliable measurements or estimates of the reaeration coefficient (k). Small errors in estimates of k can lead to large errors in estimates of gross ecosystem production and ecosystem respiration and so the magnitude of the biological flux of CO2 to or from streams. This is an especially challenging problem in unproductive, oligotrophic streams. Unfortunately, current methods to measure reaeration directly (gas evasion) are expensive, labor-intensive, and time-consuming. As a consequence, there is a substantial mismatch between the time steps at which we can measure reaeration versus most of the other variables required to calculate WSM. As a part of the NSF Arctic Long-Term Ecological Research Project we have refined methods to measure WSM in Arctic streams and found a good relationship between measured k values and those calculated by the Energy Dissipation Model (EDM). Other researchers have also noted that this equation works well for both low- and high-order streams. The EDM is dependent on stream slope (relatively constant) and velocity (which is related to discharge or stage). These variables are easy to measure and can be used to estimate k a high frequency (minutes) over large areas (river networks). As a key part of the NSF MacroSystems Biology SCALER project we calculated WSM for multiple reaches in nested stream networks in six biomes across the United States and Australia. We calculated k by EDM and fitted k via a Bayesian model for WSM. The relationships between measured k and calculated (EDM) k (standardized to 20°C) were variable but useful. The relationships between calculated (EDM) k and inferred (Bayesian) k were inconsistent, suggesting that there are additional factors we need to understand to better refine estimates of whole-stream metabolic C exchange over river networks and among regions.

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.

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.

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.

Multiple piece turbine blade/vane

DOEpatents

Kimmel, Keith D

2013-02-05

An air cooled turbine blade or vane of a spar and shell construction with the shell made from a high temperature resistant material that must be formed from an EDM process. The shell and the spar both have a number of hooks extending in a spanwise direction and forming a contact surface that is slanted such that a contact force increases as the engaging hooks move away from one another. The slanted contact surfaces on the hooks provides for an better seal and allows for twisting between the shell and the spar while maintaining a tight fit.

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.

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.

Critical current density in wire drawn and hydrostatically extruded Nb-Ti superconductors

NASA Technical Reports Server (NTRS)

Alterovitz, S. A.; Woollam, J. A.; Collings, E. W.

1979-01-01

Critical current studies have been made on copper-clad Nb-Ti composite wire prepared under area reductions of 100:1 and 10,000:1 by hydrostatic extrusion (HE), wire drawing and HE plus drawing. Comparative evaluation of the thermomechanical processing equivalent of HE was performed.

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.

The effect of strain hardening on resistance to electrochemical corrosion of wires for orthopaedics

NASA Astrophysics Data System (ADS)

Przondziono, J.; Walke, W.; Hadasik, E.; Szymszal, J.

2012-05-01

The purpose of this research is to evaluate electrochemical corrosion resistance of wire with modified surface, made of stainless steel of Cr-Ni-Mo type, widely used in implants for orthopaedics, depending on hardening created in the process of drawing. Tests have been carried out in the environment imitating human osseous tissue. Pitting corrosion was determined on the ground of registered anodic polarisation curves by means of potentiodynamic method with application of electrochemical testing system VoltaLab® PGP 201. Wire corrosion tests were carried out in Tyrode solution on samples that were electrochemically polished as well as electrochemically polished and finally chemically passivated. Initial material for tests was wire rod made of X2CrNiMo17-12-2 steel with diameter of 5.5 mm in supersaturated condition. Wire rod was drawn up to diameter of 1.35 mm. This work shows the course of flow curve of wire made of this grade of steel and mathematical form of yield stress function. The study also presents exemplary curves showing the dependence of polarisation resistance in strain function in the drawing process of electrochemically passivated and electrochemically polished and then chemically passivated wire.

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.

Ultrasonic Polishing

NASA Technical Reports Server (NTRS)

Gilmore, Randy

1993-01-01

The ultrasonic polishing process makes use of the high-frequency (ultrasonic) vibrations of an abradable tool which automatically conforms to the work piece and an abrasive slurry to finish surfaces and edges on complex, highly detailed, close tolerance cavities in materials from beryllium copper to carbide. Applications range from critical deburring of guidance system components to removing EDM recast layers from aircraft engine components to polishing molds for forming carbide cutting tool inserts or injection molding plastics. A variety of materials including tool steels, carbides, and even ceramics can be successfully processed. Since the abradable tool automatically conforms to the work piece geometry, the ultrasonic finishing method described offers a number of important benefits in finishing components with complex geometries.

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.

Simultaneous distance measurement at multiple wavelengths using the intermode beats from a femtosecond laser coherent supercontinuum

NASA Astrophysics Data System (ADS)

Salido-Monzú, David; Wieser, Andreas

2018-04-01

The intermode beats generated by direct detection of a mode-locked femtosecond laser represent inherent high-quality and high-frequency modulations suitable for electro-optical distance measurement (EDM). This approach has already been demonstrated as a robust alternative to standard long-distance EDM techniques. However, we extend this idea to intermode beating of a wideband source obtained by spectral broadening of a femtosecond laser. We aim at establishing a technological basis for accurate and flexible multiwavelength distance measurement. Results are presented from experiments using beat notes at 1 GHz generated by two bandpass-filtered regions from both extremes of a coherent supercontinuum ranging from 550 to 1050 nm. The displacement measurements performed simultaneously on both colors on a short-distance setup show that noise and coherence of the wideband laser are adequate for achieving accuracies of about 0.01 mm on each channel with a potential improvement by accessing higher beat notes. Pointing and power instabilities have been identified as dominant sources of systematic deviations. Nevertheless, the results demonstrate the basic feasibility of the proposed technique. We consider this a promising starting point for the further development of multiwavelength EDM enabling increased accuracy over long distances through dispersion-based integral refractivity compensation and for remote surface material probing along with distance measurement in laser scanning.

Motivations for Selling Ecstasy among Young Adults in the Electronic Dance Music Club Culture in Brazil.

PubMed

Remy, Lysa S; Buttram, Mance E; Kurtz, Steven P; Surratt, Hilary L; Pechansky, Flavio

2017-01-01

This article describes data on the motivations for selling ecstasy among young adults in the electronic dance music (EDM) club culture in Brazil. Individual interviews were conducted with 20 individuals recruited for their involvement in the EDM club scene. Eligible participants were aged 18-39 and reported ecstasy and/or LSD use one or more times in the past 90 days. Exclusion criteria included current treatment for drug/alcohol problems and cognitive impairment or clinically evident psychiatric disorder. Mean age was 22.92 (SD 2.77), 60% were male, 45% reported 12 or more years of education, 50% did not have a primary partner, 50% were living alone, and all had friends who also used ecstasy. Three main themes emerged: (1) "easy" transition from ecstasy user to seller; (2) desire to achieve popularity and fame; and (3) need to sell ecstasy to maintain the high cost of EDM club scene participation. This is one of the first studies of ecstasy sellers in Brazil. The results demonstrate the ease with which the participants transition from ecstasy user to seller. Given the potential health and social dangers associated with ecstasy use, public health campaigns to prevent ecstasy use and policy initiatives to limit the ecstasy supply are warranted.

Designing Free Energy Surfaces That Match Experimental Data with Metadynamics

DOE PAGES

White, Andrew D.; Dama, James F.; Voth, Gregory A.

2015-04-30

Creating models that are consistent with experimental data is essential in molecular modeling. This is often done by iteratively tuning the molecular force field of a simulation to match experimental data. An alternative method is to bias a simulation, leading to a hybrid model composed of the original force field and biasing terms. Previously we introduced such a method called experiment directed simulation (EDS). EDS minimally biases simulations to match average values. We also introduce a new method called experiment directed metadynamics (EDM) that creates minimal biases for matching entire free energy surfaces such as radial distribution functions and phi/psimore » angle free energies. It is also possible with EDM to create a tunable mixture of the experimental data and free energy of the unbiased ensemble with explicit ratios. EDM can be proven to be convergent, and we also present proof, via a maximum entropy argument, that the final bias is minimal and unique. Examples of its use are given in the construction of ensembles that follow a desired free energy. Finally, the example systems studied include a Lennard-Jones fluid made to match a radial distribution function, an atomistic model augmented with bioinformatics data, and a three-component electrolyte solution where ab initio simulation data is used to improve a classical empirical model.« less

Using Mean Orbit Period in Mars Reconnaissance Orbiter Maneuver Design

NASA Technical Reports Server (NTRS)

Chung, Min-Kun J.; Menon, Premkumar R.; Wagner, Sean V.; Williams, Jessica L.

2014-01-01

Mars Reconnaissance Orbiter (MRO) has provided communication relays for a number of Mars spacecraft. In 2016 MRO is expected to support a relay for NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft. In addition, support may be needed by another mission, ESA's ExoMars EDL Demonstrator Module's (EDM), only 21 days after the InSight coverage. The close proximity of these two events presents a unique challenge to a conventional orbit synchronization maneuver where one deterministic maneuver is executed prior to each relay. Since the two events are close together and the difference in required phasing between InSight and EDM may be up to half an orbit (yielding a large execution error), the downtrack timing error can increase rapidly at the EDM encounter. Thus, a new maneuver strategy that does not require a deterministic maneuver in-between the two events (with only a small statistical cleanup) is proposed in the paper. This proposed strategy rests heavily on the stability of the mean orbital period. The ability to search and set the specified mean period is fundamental in the proposed maneuver design as well as in understanding the scope of the problem. The proposed strategy is explained and its result is used to understand and solve the problem in the flight operations environment.

Effect of Powder-Suspended Dielectric on the EDM Characteristics of Inconel 625

NASA Astrophysics Data System (ADS)

Talla, Gangadharudu; Gangopadhyay, S.; Biswas, C. K.

2016-02-01

The current work attempts to establish the criteria for powder material selection by investigating the influence of various powder-suspended dielectrics and machining parameters on various EDM characteristics of Inconel 625 (a nickel-based super alloy) which is nowadays regularly used in aerospace, chemical, and marine industries. The powders include aluminum (Al), graphite, and silicon (Si) that have significant variation in their thermo-physical characteristics. Results showed that powder properties like electrical conductivity, thermal conductivity, density, and hardness play a significant role in changing the machining performance and the quality of the machined surface. Among the three powders, highest material removal rate was observed for graphite powder due to its high electrical and thermal conductivities. Best surface finish and least radial overcut (ROC) were attained using Si powder. Maximum microhardness was found for Si due to its low thermal conductivity and high hardness. It is followed by graphite and aluminum powders. Addition of powder to the dielectric has increased the crater diameter due to expansion of plasma channel. Powder-mixed EDM (PMEDM) was also effective in lowering the density of surface cracks with least number of cracks obtained with graphite powder. X-ray diffraction analysis indicated possible formation of metal carbides along with grain growth phenomenon of Inconel 625 after PMEDM.

Data access and decision tools for coastal water resources ...

EPA Pesticide Factsheets

US EPA has supported the development of numerous models and tools to support implementation of environmental regulations. However, transfer of knowledge and methods from detailed technical models to support practical problem solving by local communities and watershed or coastal management organizations remains a challenge. We have developed the Estuary Data Mapper (EDM) to facilitate data discovery, visualization and access to support environmental problem solving for coastal watersheds and estuaries. EDM is a stand-alone application based on open-source software which requires only internet access for operation. Initially, development of EDM focused on delivery of raw data streams from distributed web services, ranging from atmospheric deposition to hydrologic, tidal, and water quality time series, estuarine habitat characteristics, and remote sensing products. We have transitioned to include access to value-added products which provide end-users with results of future scenario analysis, facilitate extension of models across geographic regions, and/or promote model interoperability. Here we present three examples: 1) the delivery of input data for the development of seagrass models across estuaries, 2) scenarios illustrating the implications of riparian buffer management (loss or restoration) for stream thermal regimes and fish communities, and 3) access to hydrology model outputs to foster connections across models at different scales, ultimately feeding

Designing free energy surfaces that match experimental data with metadynamics.

PubMed

White, Andrew D; Dama, James F; Voth, Gregory A

2015-06-09

Creating models that are consistent with experimental data is essential in molecular modeling. This is often done by iteratively tuning the molecular force field of a simulation to match experimental data. An alternative method is to bias a simulation, leading to a hybrid model composed of the original force field and biasing terms. We previously introduced such a method called experiment directed simulation (EDS). EDS minimally biases simulations to match average values. In this work, we introduce a new method called experiment directed metadynamics (EDM) that creates minimal biases for matching entire free energy surfaces such as radial distribution functions and phi/psi angle free energies. It is also possible with EDM to create a tunable mixture of the experimental data and free energy of the unbiased ensemble with explicit ratios. EDM can be proven to be convergent, and we also present proof, via a maximum entropy argument, that the final bias is minimal and unique. Examples of its use are given in the construction of ensembles that follow a desired free energy. The example systems studied include a Lennard-Jones fluid made to match a radial distribution function, an atomistic model augmented with bioinformatics data, and a three-component electrolyte solution where ab initio simulation data is used to improve a classical empirical model.

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.

Comparison and Analysis of Geometric Correction Models of Spaceborne SAR

PubMed Central

Jiang, Weihao; Yu, Anxi; Dong, Zhen; Wang, Qingsong

2016-01-01

Following the development of synthetic aperture radar (SAR), SAR images have become increasingly common. Many researchers have conducted large studies on geolocation models, but little work has been conducted on the available models for the geometric correction of SAR images of different terrain. To address the terrain issue, four different models were compared and are described in this paper: a rigorous range-doppler (RD) model, a rational polynomial coefficients (RPC) model, a revised polynomial (PM) model and an elevation derivation (EDM) model. The results of comparisons of the geolocation capabilities of the models show that a proper model for a SAR image of a specific terrain can be determined. A solution table was obtained to recommend a suitable model for users. Three TerraSAR-X images, two ALOS-PALSAR images and one Envisat-ASAR image were used for the experiment, including flat terrain and mountain terrain SAR images as well as two large area images. Geolocation accuracies of the models for different terrain SAR images were computed and analyzed. The comparisons of the models show that the RD model was accurate but was the least efficient; therefore, it is not the ideal model for real-time implementations. The RPC model is sufficiently accurate and efficient for the geometric correction of SAR images of flat terrain, whose precision is below 0.001 pixels. The EDM model is suitable for the geolocation of SAR images of mountainous terrain, and its precision can reach 0.007 pixels. Although the PM model does not produce results as precise as the other models, its efficiency is excellent and its potential should not be underestimated. With respect to the geometric correction of SAR images over large areas, the EDM model has higher accuracy under one pixel, whereas the RPC model consumes one third of the time of the EDM model. PMID:27347973

Early detection monitoring for aquatic non-indigenous species: Optimizing surveillance, incorporating advanced technologies, and identifying research needs.

PubMed

Trebitz, Anett S; Hoffman, Joel C; Darling, John A; Pilgrim, Erik M; Kelly, John R; Brown, Emily A; Chadderton, W Lindsay; Egan, Scott P; Grey, Erin K; Hashsham, Syed A; Klymus, Katy E; Mahon, Andrew R; Ram, Jeffrey L; Schultz, Martin T; Stepien, Carol A; Schardt, James C

2017-11-01

Following decades of ecologic and economic impacts from a growing list of nonindigenous and invasive species, government and management entities are committing to systematic early- detection monitoring (EDM). This has reinvigorated investment in the science underpinning such monitoring, as well as the need to convey that science in practical terms to those tasked with EDM implementation. Using the context of nonindigenous species in the North American Great Lakes, this article summarizes the current scientific tools and knowledge - including limitations, research needs, and likely future developments - relevant to various aspects of planning and conducting comprehensive EDM. We begin with the scope of the effort, contrasting target-species with broad-spectrum monitoring, reviewing information to support prioritization based on species and locations, and exploring the challenge of moving beyond individual surveys towards a coordinated monitoring network. Next, we discuss survey design, including effort to expend and its allocation over space and time. A section on sample collection and analysis overviews the merits of collecting actual organisms versus shed DNA, reviews the capabilities and limitations of identification by morphology, DNA target markers, or DNA barcoding, and examines best practices for sample handling and data verification. We end with a section addressing the analysis of monitoring data, including methods to evaluate survey performance and characterize and communicate uncertainty. Although the body of science supporting EDM implementation is already substantial, research and information needs (many already actively being addressed) include: better data to support risk assessments that guide choice of taxa and locations to monitor; improved understanding of spatiotemporal scales for sample collection; further development of DNA target markers, reference barcodes, genomic workflows, and synergies between DNA-based and morphology-based taxonomy; and tools and information management systems for better evaluating and communicating survey outcomes and uncertainty. Published by Elsevier Ltd.

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.

Technology for Transient Simulation of Vibration during Combustion Process in Rocket Thruster

NASA Astrophysics Data System (ADS)

Zubanov, V. M.; Stepanov, D. V.; Shabliy, L. S.

2018-01-01

The article describes the technology for simulation of transient combustion processes in the rocket thruster for determination of vibration frequency occurs during combustion. The engine operates on gaseous propellant: oxygen and hydrogen. Combustion simulation was performed using the ANSYS CFX software. Three reaction mechanisms for the stationary mode were considered and described in detail. The way for obtaining quick CFD-results with intermediate combustion components using an EDM model was found. The way to generate the Flamelet library with CFX-RIF was described. A technique for modeling transient combustion processes in the rocket thruster was proposed based on the Flamelet library. A cyclic irregularity of the temperature field like vortex core precession was detected in the chamber. Frequency of flame precession was obtained with the proposed simulation technique.

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.

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.

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

Concordium 2015: Strategic Uses of Evidence to Transform Delivery Systems

PubMed Central

Holve, Erin; Weiss, Samantha

2016-01-01

In September 2015 the EDM Forum hosted AcademyHealth’s newest national conference, Concordium. The 11 papers featured in the eGEMs “Concordium 2015” special issue successfully reflect the major themes and issues discussed at the meeting. Many of the papers address informatics or methodological approaches to natural language processing (NLP) or text analysis, which is indicative of the importance of analyzing text data to gain insights into care coordination and patient-centered outcomes. Perspectives on the tools and infrastructure requirements that are needed to build learning health systems were also recurrent themes. PMID:27683671

Cryogenic magnetic coil and superconducting magnetic shield for neutron electric dipole moment searches

NASA Astrophysics Data System (ADS)

Slutsky, S.; Swank, C. M.; Biswas, A.; Carr, R.; Escribano, J.; Filippone, B. W.; Griffith, W. C.; Mendenhall, M.; Nouri, N.; Osthelder, C.; Pérez Galván, A.; Picker, R.; Plaster, B.

2017-08-01

A magnetic coil operated at cryogenic temperatures is used to produce spatial, relative field gradients below 6 ppm/cm, stable for several hours. The apparatus is a prototype of the magnetic components for a neutron electric dipole moment (nEDM) search, which will take place at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory using ultra-cold neutrons (UCN). That search requires a uniform magnetic field to mitigate systematic effects and obtain long polarization lifetimes for neutron spin precession measurements. This paper details upgrades to a previously described apparatus [1], particularly the introduction of super-conducting magnetic shielding and the associated cryogenic apparatus. The magnetic gradients observed are sufficiently low for the nEDM search at SNS.

Investigation of Machine-ability of Inconel 800 in EDM with Coated Electrode

NASA Astrophysics Data System (ADS)

Karunakaran, K.; Chandrasekaran, M.

2017-03-01

The Inconel 800 is a high temperature application alloy which is classified as a nickel based super alloy. It has wide scope in aerospace engineering, gas Turbine etc. The machine-ability studies were found limited on this material. Hence This research focuses on machine-ability studies on EDM of Inconel 800 with Silver Coated Electrolyte Copper Electrode. The purpose of coating on electrode is to reduce tool wear. The factors pulse on Time, Pulse off Time and Peck Current were considered to observe the responses of surface roughness, material removal rate, tool wear rate. Taguchi Full Factorial Design is employed for Design the experiment. Some specific findings were reported and the percentage of contribution of each parameter was furnished

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

High conductivity carbon nanotube wires from radial densification and ionic doping

NASA Astrophysics Data System (ADS)

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

2010-11-01

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

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.

Prediction of Central Burst Defects in Copper Wire Drawing Process

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

Vega, G.; NEXANS France, NMC Nexans Metallurgy Centre, Boulevard du Marais, BP39, F-62301 Lens; Haddi, A.

2011-01-17

In this study, the prediction of chevron cracks (central bursts) in copper wire drawing process is investigated using experimental and numerical approaches. The conditions of the chevron cracks creation along the wire axis depend on (i) the die angle, the friction coefficient between the die and the wire, (ii) the reduction in crosssectional area of the wire, (iii) the material properties and (iv) the drawing velocity or strain rate. Under various drawing conditions, a numerical simulation for the prediction of central burst defects is presented using an axisymmetric finite element model. This model is based on the application of themore » Cockcroft and Latham fracture criterion. This criterion was used as the damage value to estimate if and where defects will occur during the copper wire drawing. The critical damage value of the material is obtained from a uniaxial tensile test. The results show that the die angle and the reduction ratio have a significant effect on the stress distribution and the maximum damage value. The central bursts are expected to occur when the die angle and reduction ratio reach a critical value. Numerical predictions are compared with experimental observations.« less

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.

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.

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.

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.

The electrical ground support equipment for the ExoMars 2016 DREAMS scientific instrument

NASA Astrophysics Data System (ADS)

Molfese, C.; Schipani, P.; Marty, L.; Esposito, F.; D'Orsi, S.; Mannetta, M.; Debei, S.; Bettanini, C.; Aboudan, A.; Colombatti, G.; Mugnuolo, R.; Marchetti, E.; Pirrotta, S.

2014-08-01

This paper describes the Electrical Ground Support Equipment (EGSE) of the Dust characterization, Risk assessment, and Environment Analyser on the Martian Surface (DREAMS) scientific instrument, an autonomous surface payload package to be accommodated on the Entry, Descendent and landing Module (EDM) of the ExoMars 2016 European Space Agency (ESA) mission. DREAMS will perform several kinds of measurements, such as the solar irradiance with different optical detectors in the UVA band (315-400nm), NIR band (700-1100nm) and in "total luminosity" (200 -1100 nm). It will also measure environmental parameters such as the intensity of the electric field, temperature, pressure, humidity, speed and direction of the wind. The EGSE is built to control the instrument and manage the data acquisition before the integration of DREAMS within the Entry, Descendent and landing Module (EDM) and then to retrieve data from the EDM Central Checkout System (CCS), after the integration. Finally it will support also the data management during mission operations. The EGSE is based on commercial off-the-shelf components and runs custom software. It provides power supply and simulates the spacecraft, allowing the exchange of commands and telemetry according to the protocol defined by the spacecraft prime contractor. This paper describes the architecture of the system, as well as its functionalities to test the DREAMS instrument during all development activities before the ExoMars 2016 launch.

A coastal information system to propel emerging science and ...

EPA Pesticide Factsheets

The Estuary Data Mapper (EDM) is a free, interactive virtual gateway to coastal data aimed to promote research and aid in environmental management. The graphical user interface allows users to custom select and subset data based on their spatial and temporal interests giving them easy access to visualize, retrieve, and save data for further analysis. Data are accessible across estuarine systems of the Atlantic, Gulf of Mexico and Pacific regions of the United States and includes: (1) time series data including tidal, hydrologic, and weather, (2) water and sediment quality, (3) atmospheric deposition, (4) habitat, (5) coastal exposure indices, (6) historic and projected land-use and population, (7) historic and projected nitrogen and phosphorous sources and load summaries. EDM issues Web Coverage Service Interface Standard queries (WCS; simple, standard one-line text strings) to a public web service to quickly obtain data subsets by variable, for a date-time range and area selected by user. EDM is continuously being enhanced with updated data and new options. Recent additions include a comprehensive suite of nitrogen source and loading data, and inputs for supporting a modeling approach of seagrass habitat. Additions planned for the near future include 1) support for Integrated Water Resources Management cost-benefit analysis, specifically the Watershed Management Optimization Support Tool and 2) visualization of the combined effects of climate change, land-use a

Feasibility study for the Swaziland/Mozambique interconnector. Final report. Export trade information

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

NONE

1997-11-01

This study, conducted by Black & Veatch, was funded by the U.S. Trade and Development Agency. The report, produced for the Ministry of National Resources, Energy and Environment (MNRE) of Swaziland, determines the least cost capacity expansion option to meet the future power demand and system reliability criteria of Swaziland, with particular emphasis on the proposed interconnector between Swaziland and Mozambique. Volume 2, the Final Report, contains the following sections: (1.0) Introduction; (2.0) Review of SEB Power System; (3.0) SEB Load Forecast and Review; (4.0) SEB Load Forecast Revision; (5.0) The SEB Need for Power; (6.0) SEB System Development Planmore » Review; (7.0) Southern Mozambique EdM power System Review; (8.0) Southern Mozambique EdM Energy and Demand; (9.0) Supply Side Capacity Options for Swaziland and Mozambique; (10.0) SEB Expansion Plan Development; (11.0) EdM Expansion Plan Development; (12.0) Cost Sharing of the Interconnector; (13.0) Enviroinmental Evaluation of Interconnector Options; (14.0) Generation/Transmission Trade Offs; (15.0) Draft Interconnection Agreement and Contract Packages; (16.0) Transmission System Study; (17.0) Automatic General Control; (18.0) Automatic Startup and Shutdown of Hydro Electric Power Plants; (19.0) Communications and Metering; (20.0) Conclusions and Recommendations; Appendix A: Demand Side Management Primer; Appendix B. PURPA and Avoided Cost Calculations.« less

Estuary Data Mapper: A coastal information system to propel ...

EPA Pesticide Factsheets

The Estuary Data Mapper (EDM) is a free, interactive virtual gateway to coastal data aimed to promote research and aid in environmental management. The graphical user interface allows users to custom select and subset data based on their spatial and temporal interests giving them easy access to visualize, retrieve, and save data for further analysis. Data are accessible across estuarine systems of the Atlantic, Gulf of Mexico and Pacific regions of the United States and includes: (1) time series data including tidal, hydrologic, and weather, (2) water and sediment quality, (3) atmospheric deposition, (4) habitat, (5) coastal exposure indices, (6) historic and projected land-use and population, (7) historic and projected nitrogen and phosphorous sources and load summaries. EDM issues Web Coverage Service Interface Standard queries (WCS; simple, standard one-line text strings) to a public web service to quickly obtain data subsets by variable, for a date-time range and area selected by user. EDM is continuously being enhanced with updated data and new options. Recent additions include a comprehensive suite of nitrogen source and loading data, and inputs for supporting a modeling approach of seagrass habitat. Additions planned for the near future include 1) support for Integrated Water Resources Management cost-benefit analysis, specifically the Watershed Management Optimization Support Tool and 2) visualization of the combined effects of climate change, land-use a

Evaluation of Fatigue Behavior and Surface Characteristics of Aluminum Alloy 2024 T6 After Electric Discharge Machining

NASA Astrophysics Data System (ADS)

Mehmood, Shahid; Shah, Masood; Pasha, Riffat Asim; Sultan, Amir

2017-10-01

The effect of electric discharge machining (EDM) on surface quality and consequently on the fatigue performance of Al 2024 T6 is investigated. Five levels of discharge current are analyzed, while all other electrical and nonelectrical parameters are kept constant. At each discharge current level, dog-bone specimens are machined by generating a peripheral notch at the center. The fatigue tests are performed on four-point rotating bending machine at room temperature. For comparison purposes, fatigue tests are also performed on the conventionally machined specimens. Linearized SN curves for 95% failure probability and with four different confidence levels (75, 90, 95 and 99%) are plotted for each discharge current level as well as for conventionally machined specimens. These plots show that the electric discharge machined (EDMed) specimens give inferior fatigue behavior as compared to conventionally machined specimen. Moreover, discharge current inversely affects the fatigue life, and this influence is highly pronounced at lower stresses. The EDMed surfaces are characterized by surface properties that could be responsible for change in fatigue life such as surface morphology, surface roughness, white layer thickness, microhardness and residual stresses. It is found that all these surface properties are affected by changing discharge current level. However, change in fatigue life by discharge current could not be associated independently to any single surface property.

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.

Welder--Wire Process Operator: Apprenticeship Course Outline. Apprenticeship and Industry Training. 12-107.2

ERIC Educational Resources Information Center

Alberta Advanced Education and Technology, 2007

2007-01-01

The graduate of the Wire Process Operator apprenticeship program is a certified journeyperson who will be able to: (1) be skillful in the fusing of metals using prescribed welding applications; (2) have a working knowledge of the welding equipment involved with the various welding procedures; (3) comprehend drawings; (4) have a thorough knowledge…

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.

Argonne simulation framework for intelligent transportation systems

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

Ewing, T.; Doss, E.; Hanebutte, U.

1996-04-01

A simulation framework has been developed which defines a high-level architecture for a large-scale, comprehensive, scalable simulation of an Intelligent Transportation System (ITS). The simulator is designed to run on parallel computers and distributed (networked) computer systems; however, a version for a stand alone workstation is also available. The ITS simulator includes an Expert Driver Model (EDM) of instrumented ``smart`` vehicles with in-vehicle navigation units. The EDM is capable of performing optimal route planning and communicating with Traffic Management Centers (TMC). A dynamic road map data base is sued for optimum route planning, where the data is updated periodically tomore » reflect any changes in road or weather conditions. The TMC has probe vehicle tracking capabilities (display position and attributes of instrumented vehicles), and can provide 2-way interaction with traffic to provide advisories and link times. Both the in-vehicle navigation module and the TMC feature detailed graphical user interfaces that includes human-factors studies to support safety and operational research. Realistic modeling of variations of the posted driving speed are based on human factor studies that take into consideration weather, road conditions, driver`s personality and behavior and vehicle type. The simulator has been developed on a distributed system of networked UNIX computers, but is designed to run on ANL`s IBM SP-X parallel computer system for large scale problems. A novel feature of the developed simulator is that vehicles will be represented by autonomous computer processes, each with a behavior model which performs independent route selection and reacts to external traffic events much like real vehicles. Vehicle processes interact with each other and with ITS components by exchanging messages. With this approach, one will be able to take advantage of emerging massively parallel processor (MPP) systems.« less

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.

Estuary Data Mapper (EDM)

EPA Pesticide Factsheets

Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

Progress towards an electron electric dipole moment search in Europium-Barium Titanates

NASA Astrophysics Data System (ADS)

Eckel, Stephen; Sushkov, Alexander; Lamoreaux, Steven

2012-06-01

We report on recent progress on a search for the electron's electric dipole moment (eEDM) using solid- state Eu0.5Ba0.5TiO3. This material has many desirable properties including ferroelectricity below 200 K and paramagnetism above 1.8 K. When the sample has a non-zero electric polarization, the seven unpaired 4f electrons of the Eu^2+ ions in the lattice feel a large effective electric field of order 10 MV/cm in the direction of the polarization. This causes the electron spins to align with the electric polarization and generate a magnetization, which is measured using DC SQUID magnetometers. We will detail measurements of systematic effects along with recent results toward a measurement of the eEDM.

Electroweak baryogenesis, electric dipole moments, and Higgs diphoton decays

DOE PAGES

Chao, Wei; Ramsey-Musolf, Michael J.

2014-10-30

Here, we study the viability of electroweak baryogenesis in a two Higgs doublet model scenario augmented by vector-like, electroweakly interacting fermions. Considering a limited, but illustrative region of the model parameter space, we obtain the observed cosmic baryon asymmetry while satisfying present constraints from the non-observation of the permanent electric dipole moment (EDM) of the electron and the combined ATLAS and CMS result for the Higgs boson diphoton decay rate. The observation of a non-zero electron EDM in a next generation experiment and/or the observation of an excess (over the Standard Model) of Higgs to diphoton events with the 14more » TeV LHC run or a future e +e – collider would be consistent with generation of the observed baryon asymmetry in this scenario.« less

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.

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.

About Estuary Data Mapper (EDM)

EPA Pesticide Factsheets

Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions.

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.

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.

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.

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.

Synthesis of Commercial Products from Copper Wire-Drawing Waste

NASA Astrophysics Data System (ADS)

Ayala, J.; Fernández, B.

2014-06-01

Copper powder and copper sulfate pentahydrate were obtained from copper wire-drawing scale. The hydrometallurgical recycling process proposed in this article yields a high-purity copper powder and analytical grade copper sulfate pentahydrate. In the first stage of this process, the copper is dissolved in sulfuric acid media via dismutation of the scale. In the second stage, copper sulfate pentahydrate is precipitated using ethanol. Effects such as pH, reaction times, stirring speed, initial copper concentration, and ethanol/solution volume ratio were studied during the precipitation from solution reaction. The proposed method is technically straightforward and provides efficient recovery of Cu from wire-drawing scale.

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.

Subsidence from an artificial permafrost warming experiment.

NASA Astrophysics Data System (ADS)

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

2017-12-01

Using fiber optic sensing technologies (seismic, strain, and temperature) we installed a geophysical detection system to predict thaw subsidence in Fairbanks, Alaska, United States. Approximately 5 km of fiber optic was buried in shallow trenches (20 cm depth), in an area with discontinuous permafrost, where the top of the permafrost is approximately 4 - 4.5m below the surface. The thaw subsidence was enforced by 122 60-Watt vertical heaters installed over a 140 m2 area where seismic, strain, and temperature were continuously monitored throughout the length of the fiber. Several vertical thermistor strings were also recording ground temperatures to a depth of 10 m in parallel to the fiber optic to verify the measurements collected from the fiber optic cable. GPS, Electronic Distance Measurement (EDM) Traditional and LiDAR (Light and Detection and Ranging) scanning were used to investigate the surface subsidence. The heaters were operating for approximately a three month period starting in August, 2016. During the heating process the soil temperatures at the heater element increased from 3.5 to 45 °C at a depth of 3 - 4 m. It took approximately 7 months for the temperature at the heater elements to recover to their initial temperature. The depth to the permafrost table was deepened by about 1 m during the heating process. By the end of the active heating, the surface had subsided approximately 8 cm in the heating section where permafrost was closest to the surface. This was conclusively confirmed with GPS, EDM, and LiDAR. An additional LiDAR survey was performed about seven months after the heaters were turned off (in May 2017). A total subsidence of approximately 20 cm was measured by the end of the passive heating process. This project successfully demonstrates that this is a viable approach for simulating both deep permafrost thaw and the resulting surface subsidence.

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.

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 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

Plastohydrodynamic drawing and coating of stainless steel wire using a tapered bore die of no metal to metal contact

NASA Astrophysics Data System (ADS)

Hasan, S.; Basmage, O.; Stokes, J. T.; Hashmi, M. S. J.

2018-05-01

A review of wire coating studies using plasto-hydrodynamic pressure shows that most of the works were carried out by conducting experiments simultaneously with simulation analysis based upon Bernoulli's principle and Euler and Navier-Stokes (N-S) equations. These characteristics relate to the domain of Computational Fluid Dynamics (CFD) which is an interdisciplinary topic (Fluid Mechanics, Numerical Analysis of Fluid flow and Computer Science). This research investigates two aspects: (i) simulation work and (ii) experimentation. A mathematical model was developed to investigate the flow pattern of the molten polymer and pressure distribution within the wire-drawing dies, assessment of polymer coating thickness on the coated wires and speed of coating on the wires at the outlet of the drawing dies, without deploying any pressurizing pump. In addition to a physical model which was developed within ANSYS™ environment through the simulation design of ANSYS™ Workbench. The design was customized to simulate the process of wire-coating on the fine stainless-steel wires using drawing dies having different bore geometries such as: stepped parallel bore, tapered bore and combined parallel and tapered bore. The convergence of the designed CFD model and numerical and physical solution parameters for simulation were dynamically monitored for the viscous flow of the polypropylene (PP) polymer. Simulation results were validated against experimental results and used to predict the ideal bore shape to produce a thin coating on stainless wires with different diameter. Simulation studies confirmed that a specific speed should be attained by the stainless-steel wires while passing through the drawing dies. It has been observed that all the speed values within specific speed range did not produce a coating thickness having the desired coating characteristic features. Therefore, some optimization of the experimental set up through design of experiments (Stat-Ease) was applied to validate the results. Further rapid solidification of the viscous coating on the wires was targeted so that the coated wires do not stick to the winding spool after the coating process.

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.

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.

Downloading and Installing Estuary Data Mapper (EDM)

EPA Pesticide Factsheets

Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

Frequent Questions about Estuary Data Mapper (EDM)

EPA Pesticide Factsheets

Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

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.

Workshop on Aeronautical Decision Making (ADM). Volume 1. Executive Summary

DTIC Science & Technology

1992-08-01

expert and novice pilots when a real decision was required. Aeronautical Decision Making (ADM), Crew Resource Management (CRM), Advanced Qualification Program (AQP), Cognitive Task Analysis (CTA), Expert Decision Making (EDM)

Comparison of residual stresses in Inconel 718 simple parts made by electron beam melting and direct laser metal sintering

DOE PAGES

Kolbus, Lindsay M.; Payzant, E. Andrew; Cornwell, Paris A.; ...

2015-01-10

Residual stress profiles were mapped using neutron diffraction in two simple prism builds of Inconel 718: one fabricated with electron beam melting and the other with direct laser sintering. Spatially indexed stress-free cubes were obtained by EDM sectioning equivalent prisms of similar shape. The (311) interplanar spacing examined for the EDM sectioned sample was compared to the interplanar spacings calculated to fulfill force and moment balance. We have shown that Applying force and moment balance is a necessary supplement to the measurements for the stress-free cubes with respect to accurate stress calculations in additively manufactured components. Furthermore, our work hasmore » shown that residual stresses in electron beam melting parts are much smaller than that of direct laser metal sintering parts.« less

Zeroth order regular approximation approach to electric dipole moment interactions of the electron.

PubMed

Gaul, Konstantin; Berger, Robert

2017-07-07

A quasi-relativistic two-component approach for an efficient calculation of P,T-odd interactions caused by a permanent electric dipole moment of the electron (eEDM) is presented. The approach uses a (two-component) complex generalized Hartree-Fock and a complex generalized Kohn-Sham scheme within the zeroth order regular approximation. In applications to select heavy-elemental polar diatomic molecular radicals, which are promising candidates for an eEDM experiment, the method is compared to relativistic four-component electron-correlation calculations and confirms values for the effective electric field acting on the unpaired electron for RaF, BaF, YbF, and HgF. The calculations show that purely relativistic effects, involving only the lower component of the Dirac bi-spinor, are well described by treating only the upper component explicitly.

Zeroth order regular approximation approach to electric dipole moment interactions of the electron

NASA Astrophysics Data System (ADS)

Gaul, Konstantin; Berger, Robert

2017-07-01

A quasi-relativistic two-component approach for an efficient calculation of P ,T -odd interactions caused by a permanent electric dipole moment of the electron (eEDM) is presented. The approach uses a (two-component) complex generalized Hartree-Fock and a complex generalized Kohn-Sham scheme within the zeroth order regular approximation. In applications to select heavy-elemental polar diatomic molecular radicals, which are promising candidates for an eEDM experiment, the method is compared to relativistic four-component electron-correlation calculations and confirms values for the effective electric field acting on the unpaired electron for RaF, BaF, YbF, and HgF. The calculations show that purely relativistic effects, involving only the lower component of the Dirac bi-spinor, are well described by treating only the upper component explicitly.

Methods, analysis, and the treatment of systematic errors for the electron electric dipole moment search in thorium monoxide

NASA Astrophysics Data System (ADS)

Baron, J.; Campbell, W. C.; DeMille, D.; Doyle, J. M.; Gabrielse, G.; Gurevich, Y. V.; Hess, P. W.; Hutzler, N. R.; Kirilov, E.; Kozyryev, I.; O'Leary, B. R.; Panda, C. D.; Parsons, M. F.; Spaun, B.; Vutha, A. C.; West, A. D.; West, E. P.; ACME Collaboration

2017-07-01

We recently set a new limit on the electric dipole moment of the electron (eEDM) (J Baron et al and ACME collaboration 2014 Science 343 269-272), which represented an order-of-magnitude improvement on the previous limit and placed more stringent constraints on many charge-parity-violating extensions to the standard model. In this paper we discuss the measurement in detail. The experimental method and associated apparatus are described, together with the techniques used to isolate the eEDM signal. In particular, we detail the way experimental switches were used to suppress effects that can mimic the signal of interest. The methods used to search for systematic errors, and models explaining observed systematic errors, are also described. We briefly discuss possible improvements to the experiment.

The experimental research on electrodischarge drilling of high aspect ratio holes in Inconel 718

NASA Astrophysics Data System (ADS)

Lipiec, Piotr; Machno, Magdalena; Skoczypiec, Sebastian

2018-05-01

In recent years the drilling operations become important area of electrodischarge machining (EDM) application. This especially concerns drilling of, small (D< 1mm), cylindrical and high-aspect ratio (L/D > 10) holes in difficult-to-cut materials (i.e. nickel or titanium alloys). Drilling of such a holes is significantly beyond mechanical drilling capabilities. Therefore electrodischarge machining is good and cost efficient alternative for such application. EDM gives possibility to drill accurate, burr free and high aspect ratio holes and is applicable to machine wide range of conductive materials, irrespective of their hardness and toughness. However it is worth to underline its main disadvantages such as: significant tool wear, low material removal rate and poor surface integrity. The last one is especially important in reliable applications in aircraft or medical industry.

Study of orifice fabrication technologies for the liquid droplet radiator

NASA Technical Reports Server (NTRS)

Wallace, David B.; Hayes, Donald J.; Bush, J. Michael

1991-01-01

Eleven orifice fabrication technologies potentially applicable for a liquid droplet radiator are discussed. The evaluation is focused on technologies capable of yielding 25-150 microns diameter orifices with trajectory accuracies below 5 milliradians, ultimately in arrays of up to 4000 orifices. An initial analytical screening considering factors such as trajectory accuracy, manufacturability, and hydrodynamics of orifice flow is presented. Based on this screening, four technologies were selected for experimental evaluation. A jet straightness system used to test 50-orifice arrays made by electro-discharge machining (EDM), Fotoceram, and mechanical drilling is discussed. Measurements on orifice diameter control and jet trajectory accuracy are presented and discussed. Trajectory standard deviations are in the 4.6-10.0 milliradian range. Electroforming and EDM appear to have the greatest potential for Liquid Droplet Radiator applications. The direction of a future development effort is discussed.

New computational tools for H/D determination in macromolecular structures from neutron data.

PubMed

Siliqi, Dritan; Caliandro, Rocco; Carrozzini, Benedetta; Cascarano, Giovanni Luca; Mazzone, Annamaria

2010-11-01

Two new computational methods dedicated to neutron crystallography, called n-FreeLunch and DNDM-NDM, have been developed and successfully tested. The aim in developing these methods is to determine hydrogen and deuterium positions in macromolecular structures by using information from neutron density maps. Of particular interest is resolving cases in which the geometrically predicted hydrogen or deuterium positions are ambiguous. The methods are an evolution of approaches that are already applied in X-ray crystallography: extrapolation beyond the observed resolution (known as the FreeLunch procedure) and a difference electron-density modification (DEDM) technique combined with the electron-density modification (EDM) tool (known as DEDM-EDM). It is shown that the two methods are complementary to each other and are effective in finding the positions of H and D atoms in neutron density maps.

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.

Predicting the difficulty of pure, strict, epistatic models: metrics for simulated model selection.

PubMed

Urbanowicz, Ryan J; Kiralis, Jeff; Fisher, Jonathan M; Moore, Jason H

2012-09-26

Algorithms designed to detect complex genetic disease associations are initially evaluated using simulated datasets. Typical evaluations vary constraints that influence the correct detection of underlying models (i.e. number of loci, heritability, and minor allele frequency). Such studies neglect to account for model architecture (i.e. the unique specification and arrangement of penetrance values comprising the genetic model), which alone can influence the detectability of a model. In order to design a simulation study which efficiently takes architecture into account, a reliable metric is needed for model selection. We evaluate three metrics as predictors of relative model detection difficulty derived from previous works: (1) Penetrance table variance (PTV), (2) customized odds ratio (COR), and (3) our own Ease of Detection Measure (EDM), calculated from the penetrance values and respective genotype frequencies of each simulated genetic model. We evaluate the reliability of these metrics across three very different data search algorithms, each with the capacity to detect epistatic interactions. We find that a model's EDM and COR are each stronger predictors of model detection success than heritability. This study formally identifies and evaluates metrics which quantify model detection difficulty. We utilize these metrics to intelligently select models from a population of potential architectures. This allows for an improved simulation study design which accounts for differences in detection difficulty attributed to model architecture. We implement the calculation and utilization of EDM and COR into GAMETES, an algorithm which rapidly and precisely generates pure, strict, n-locus epistatic models.