WorldWideScience

Sample records for autoreclosure arc failure

  1. Single-phase AutoReClosure ARC failure on 400 kV combinedcable/overhead line with permanently connected shunt reactor

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Søgaard, Kim

    2008-01-01

    consisting of overhead lines, crossbonded cable sections and shunt reactor has been created in PSCAD/EMTDC and verified against measurements with good results. Main focus has been put on the likelihood of having a successful single-phase autoreclosure ARC in such a combined cable/OHL line....

  2. A REVIEW OF ADAPTIVE AUTORECLOSURE TECHNIQUES

    Directory of Open Access Journals (Sweden)

    PHILIP YAW OKYERE

    2010-10-01

    Full Text Available Adaptive autoreclosing is a fast emerging technology for improving power system marginal stability during faults. It avoids reclosing untopermanent faults and recloses unto transient faults only after the secondary arc has extinguished. This paper presents a comprehensive review of various adaptive autoreclosure techniques. It aims at providing a broad perspective on adaptive autoreclosing techniques to researchers and application engineers.

  3. Single-phase AutoReClosure ARC failure on 400 kV combinedcable/overhead line with permanently connected shunt reactor

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Søgaard, Kim

    2008-01-01

    This paper demonstrates the results from a detailed study of the dynamic behavior of a shunt reactor compensated 400 kV combined cable/overhead line. This is accomplished by means of theoretical considerations, simulations and measurements. The work presented here is based on a real-life operating...

  4. Design and implementation of an adaptive single pole autoreclosure technique for transmission lines using artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Fitton, D.S.; Dunn, R.W.; Aggarwal, R.K.; Johns, A.T. [Univ. of Bath (United Kingdom). School of Electronic and Electrical Engineering; Bennett, A. [Reyrolle Protection, Hebburn (United Kingdom)

    1996-04-01

    Adaptive Single Pole AutoReclosure (SPAR) offers many advantages over conventional techniques. In the case of transient faults, the secondary arc extinction time can be accurately determined and in the case of a permanent fault, breaker reclosure can be avoided. This paper describes, in some detail, the design and implementation of a SPAR technique using Artificial Neural Networks (ANNs). The design described includes special methods for extracting features from post-circuit break opening fault data, which is a prerequisite for setting up training data sets. The technique is then implemented in hardware based on a high performance T800 transputer system and some results obtained from laboratory tests of this equipment are presented.

  5. Ballistic-Failure Mechanisms in Gas Metal Arc Welds of MIL A46100 Armor-Grade Steel: A Computational Investigation

    Science.gov (United States)

    2014-06-12

    P.O. Box 12211 Research Triangle Park, NC 27709-2211 Gas Metal Arc Welding (GMAW) Process Modeling; Ballistic Limit; Welded All-metal Armor REPORT...THE ABOVE ADDRESS. Clemson University 300 Brackett Hall Box 345702 Clemson, SC 29634 -5702 ABSTRACT Ballistic-Failure Mechanisms in Gas Metal Arc ...SECURITY CLASSIFICATION OF: In our recent work, a multi-physics computational model for the conventional Gas Metal Arc Welding (GMAW) joining process was

  6. Ballistic-Failure Mechanisms in Gas Metal Arc Welds of Mil A46100 Armor-Grade Steel: A Computational Investigation

    Science.gov (United States)

    Grujicic, M.; Snipes, J. S.; Galgalikar, R.; Ramaswami, S.; Yavari, R.; Yen, C.-F.; Cheeseman, B. A.

    2014-09-01

    In our recent work, a multi-physics computational model for the conventional gas metal arc welding (GMAW) joining process was introduced. The model is of a modular type and comprises five modules, each designed to handle a specific aspect of the GMAW process, i.e.: (i) electro-dynamics of the welding-gun; (ii) radiation-/convection-controlled heat transfer from the electric-arc to the workpiece and mass transfer from the filler-metal consumable electrode to the weld; (iii) prediction of the temporal evolution and the spatial distribution of thermal and mechanical fields within the weld region during the GMAW joining process; (iv) the resulting temporal evolution and spatial distribution of the material microstructure throughout the weld region; and (v) spatial distribution of the as-welded material mechanical properties. In the present work, the GMAW process model has been upgraded with respect to its predictive capabilities regarding the spatial distribution of the mechanical properties controlling the ballistic-limit (i.e., penetration-resistance) of the weld. The model is upgraded through the introduction of the sixth module in the present work in recognition of the fact that in thick steel GMAW weldments, the overall ballistic performance of the armor may become controlled by the (often inferior) ballistic limits of its weld (fusion and heat-affected) zones. To demonstrate the utility of the upgraded GMAW process model, it is next applied to the case of butt-welding of a prototypical high-hardness armor-grade martensitic steel, MIL A46100. The model predictions concerning the spatial distribution of the material microstructure and ballistic-limit-controlling mechanical properties within the MIL A46100 butt-weld are found to be consistent with prior observations and general expectations.

  7. Thermal analysis of an arc heater electrode with a rotating arc foot

    Science.gov (United States)

    Milos, Frank S.; Shepard, Charles E.

    1993-01-01

    A smoothly rotating arc foot and an arc foot that jumps between multiple sticking points were analyzed using analytic formulations and numerical solution procedures. For each case the temperature distribution for a copper electrode was obtained for the plausible range of operating conditions. It is shown that the smoothly rotating arc foot is an extremely safe mode of operation, whereas the jumping arc foot produces excessively high electrode surface temperatures which are not greatly alleviated by increasing the average rotational frequency of the arc foot. It is suggested to eliminate arc-foot rotation and rely on the distribution of fixed electrodes with stationary arc attachment to avoid electrode failure at high current.

  8. Cathodic arcs

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2003-10-29

    Cathodic arc plasma deposition has become the technology of choice for hard, wear and corrosion resistant coatings for a variety of applications. The history, basic physics of cathodic arc operation, the infamous macroparticle problem and common filter solutions, and emerging high-tech applications are briefly reviewed. Cathodic arc plasmas standout due to their high degree of ionization, with important consequences for film nucleation, growth, and efficient utilization of substrate bias. Industrial processes often use cathodic arc plasma in reactive mode. In contrast, the science of arcs has focused on the case of vacuum arcs. Future research directions include closing the knowledge gap for reactive mode, large area coating, linear sources and filters, metal plasma immersion process, with application in high-tech and biomedical fields.

  9. Cathodic arcs

    OpenAIRE

    Anders, Andre

    2003-01-01

    Cathodic arc plasma deposition has become the technology of choice for hard, wear and corrosion resistant coatings for a variety of applications. The history, basic physics of cathodic arc operation, the infamous macroparticle problem and common filter solutions, and emerging high-tech applications are briefly reviewed. Cathodic arc plasmas stand out due to their high degree of ionization, with important consequences for film nucleation, growth, and efficient utilization of substrate bia...

  10. Arc Statistics

    CERN Document Server

    Meneghetti, M; Dahle, H; Limousin, M

    2013-01-01

    The existence of an arc statistics problem was at the center of a strong debate in the last fifteen years. With the aim to clarify if the optical depth for giant gravitational arcs by galaxy clusters in the so called concordance model is compatible with observations, several studies were carried out which helped to significantly improve our knowledge of strong lensing clusters, unveiling their extremely complex internal structure. In particular, the abundance and the frequency of strong lensing events like gravitational arcs turned out to be a potentially very powerful tool to trace the structure formation. However, given the limited size of observational and theoretical data-sets, the power of arc statistics as a cosmological tool has been only minimally exploited so far. On the other hand, the last years were characterized by significant advancements in the field, and several cluster surveys that are ongoing or planned for the near future seem to have the potential to make arc statistics a competitive cosmo...

  11. Modeling rf breakdown arcs

    CERN Document Server

    Insepov, Zeke; Huang, Dazhang; Mahalingam, Sudhakar; Veitzer, Seth

    2010-01-01

    We describe breakdown in 805 MHz rf accelerator cavities in terms of a number of mechanisms. We devide the breakdown process into three stages: (1) we model surface failure using molecular dynamics of fracture caused by electrostatic tensile stress, (2) we model the ionization of neutrals responsible for plasma initiation and plasma growth using a particle in cell code, and (3) we model surface damage by assuming a process similar to unipolar arcing. Although unipolar arcs are strictly defined with equipotential boundaries, we find that the cold, dense plasma in contact with the surface produces very small Debye lengths and very high electric fields over a large area. These high fields produce strong erosion mechanisms, primarily self sputtering, compatible with the crater formation that we see. Results from the plasma simulation are included as a guide to experimental verification of this model.

  12. Gas arc constriction for plasma arc welding

    Science.gov (United States)

    McGee, William F. (Inventor); Rybicki, Daniel J. (Inventor)

    1994-01-01

    A welding torch for plasma arc welding apparatus has an inert gas applied circumferentially about the arc column externally of the constricting nozzle so as to apply a constricting force on the arc after it has exited the nozzle orifice and downstream of the auxiliary shielding gas. The constricting inert gas is supplied to a plenum chamber about the body of the torch and exits through a series of circumferentially disposed orifices in an annular wall forming a closure at the forward end of the constricting gas plenum chamber. The constricting force of the circumferential gas flow about the arc concentrates and focuses the arc column into a more narrow and dense column of energy after exiting the nozzle orifice so that the arc better retains its energy density prior to contacting the workpiece.

  13. Arc erosion behavior of a nanocomposite W-Cu electrical contact material

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The erosion behavior of a nanocomposite W-Cu material under arc breakdown was investigated. The arc erosion rates of the material were determined, and the eroded surfaces and arc erosion mechanisms were studied by scanning electron microscopy. It is concluded that the nanocomposite W-Cu electrical contact material shows a characteristic of spreading arcs. The arc breakdown of a commercially used W-Cu alloy was limited in a few areas, and its average arc erosion rate is twice as large as that of the former. Furthermore, it is also proved that the arc extinction ability and arc stability of the nanocomposite W-Cu material are excellent, and melting is the major failure modality in the make-and-break operation of arcs.

  14. Wire + Arc Additive Manufacturing

    OpenAIRE

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

    2016-01-01

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

  15. Welding arc plasma physics

    Science.gov (United States)

    Cain, Bruce L.

    1990-01-01

    The problems of weld quality control and weld process dependability continue to be relevant issues in modern metal welding technology. These become especially important for NASA missions which may require the assembly or repair of larger orbiting platforms using automatic welding techniques. To extend present welding technologies for such applications, NASA/MSFC's Materials and Processes Lab is developing physical models of the arc welding process with the goal of providing both a basis for improved design of weld control systems, and a better understanding of how arc welding variables influence final weld properties. The physics of the plasma arc discharge is reasonably well established in terms of transport processes occurring in the arc column itself, although recourse to sophisticated numerical treatments is normally required to obtain quantitative results. Unfortunately the rigor of these numerical computations often obscures the physics of the underlying model due to its inherent complexity. In contrast, this work has focused on a relatively simple physical model of the arc discharge to describe the gross features observed in welding arcs. Emphasis was placed of deriving analytic expressions for the voltage along the arc axis as a function of known or measurable arc parameters. The model retains the essential physics for a straight polarity, diffusion dominated free burning arc in argon, with major simplifications of collisionless sheaths and simple energy balances at the electrodes.

  16. Dynamics of diachronous back-arc extension: insights from 3D thermo-mechanical analogue experiments

    Science.gov (United States)

    Boutelier, D. A.; Cruden, A. R.

    2013-12-01

    Subduction of an old, dense oceanic lithosphere can lead to rifting and extension of the magmatic arc. Such subduction systems are inherently three-dimensional with significant along-strike variations in the timing and style of deformation and magmatism. Geodynamic models used to explain such variations and associated trench curvature generally ignore the role of the overriding plate and its deformation. 3D thermo-mechanical analogue experiments are used to investigate the kinematics and dynamics of diachronous arc rifting and back-arc basin opening. In the models, horizontal tension increases in the upper plate until the magmatic arc lithosphere fails and back-arc opening occurs via slab rollback. This result corresponds well to previous 2D models of arc rifting and subsequent back-arc opening via trench rollback and the mechanics of retreating slabs in fluid dynamic experiments. However, in our experiments arc failure occurs diachronously, initiating near the model edge due to locally higher temperatures and lower strength and then propagating along strike, producing an arcuate plate boundary. The experiments demonstrate that trench rollback rate is limited by the propagation rate of arc failure. Conversely, slab rollback generates additional horizontal tension in the adjacent magmatic arc lithosphere, which drives along-strike propagation of arc failure. Feedback between the rates of trench rollback and arc failure propagation dictates the geometry of the back-arc basin in plan-view. The shape of the back-arc basin obtained in models fits remarkably well with that of the Mariana basin in the western Pacific. Experiments where the strength of the magmatic arc, or forearc varies along strike or where the negative buoyancy of the subducting plate varies along strike explore further the role of the slab edge and the trench-parallel tensile strength of the retreating forearc block.

  17. WSTF electrical arc projects

    Science.gov (United States)

    Linley, Larry

    1994-09-01

    The objectives of these projects include the following: validate method used to screen wire insulation with arc tracking characteristics; determine damage resistance to arc as a function of source voltage and insulation thickness; investigate propagation characteristics of Kapton at low voltages; and investigate pyrolytic properties of polyimide insulated (Kapton) wire for low voltage (less than 35 VDC) applications. Supporting diagrams and tables are presented.

  18. Circular-Arc Cartograms

    CERN Document Server

    Kämper, Jan-Hinrich; Nöllenburg, Martin

    2011-01-01

    We present a new circular-arc cartogram model in which countries are drawn with circular arcs instead of straight-line segments. Given a geographic map and values associated with each country in the map, the cartogram is a new map in which the areas of the countries represent the corresponding values. In the circular-arc cartogram model straight-line segments can be replaced with circular arcs in order to achieve the desired areas, while the corners of the polygons defining each country remain fixed. The countries in circular-arc cartograms have the aesthetically pleasing appearance of clouds or snowflakes, depending on whether their edges are bent outwards or inwards. This makes is easy to determine whether a country has grown or shrunk, just by its overall shape. We show that determining whether a given map and area-values can be realized with a circular-arc cartogram is an NP-hard problem. Next we describe a heuristic method for constructing circular-arc cartograms, which uses a max-flow computation on the...

  19. Filtered cathodic arc source

    Science.gov (United States)

    Falabella, Steven; Sanders, David M.

    1994-01-01

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45.degree. to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles.

  20. Pulsed plasma arc cladding

    Institute of Scientific and Technical Information of China (English)

    龙; 白钢; 李振民; 张赋升; 杨思乾

    2004-01-01

    A prototype of Pulsed Plasma Arc Cladding system was developed, in which single power source supplies both transferred plasma arc (TPA) and non-transferred plasma arc (N-TPA). Both plasmas work in turn in a high frequency controlled by an IGBT connecting nozzle and workpiece. The working frequency of IGBT ranges from 50 ~ 7000Hz, in which the plasmas can work in turn smoothly. Higher than 500 Hz of working frequency is suggested for promotion of cladding quality and protection of IGBT. Drag phenomenon of TPA intensifies as the frequency goes up, which tends to increase the current proportion of TPA and suppress N-TPA. The occupation ratio of IGBT can be regulated from 5% ~ 95%, which balances the power supplies of both plasmas. An occupation ratio higher than 50% gives adequate proportion of arc current for N-TPA to preheat powder.

  1. Modeling of Arc Force in Plasma Arc Welding

    Institute of Scientific and Technical Information of China (English)

    GAO Zhonglin; HU Shengsun; YIN Fengliang; WANG Rui

    2008-01-01

    A three. dimensional mathematical model for the transferred-type argon arc was developed to describe arc force on the anode surface. The software ANSYS was employed to solve the model. The model includes a part of torch and tungsten electrode to achieve m ore reasonable results. The arc temperature and flow fields were derived. And the influences of welding parameters on arc force were also studied. The simulated results show that arc pressure at the anode are dependent on the welding current, plasma gas flow rate and electrode neck-in, while not sensitive to arc length.

  2. Arc Plasma Torch Modeling

    CERN Document Server

    Trelles, J P; Vardelle, A; Heberlein, J V R

    2013-01-01

    Arc plasma torches are the primary components of various industrial thermal plasma processes involving plasma spraying, metal cutting and welding, thermal plasma CVD, metal melting and remelting, waste treatment and gas production. They are relatively simple devices whose operation implies intricate thermal, chemical, electrical, and fluid dynamics phenomena. Modeling may be used as a means to better understand the physical processes involved in their operation. This paper presents an overview of the main aspects involved in the modeling of DC arc plasma torches: the mathematical models including thermodynamic and chemical non-equilibrium models, turbulent and radiative transport, thermodynamic and transport property calculation, boundary conditions and arc reattachment models. It focuses on the conventional plasma torches used for plasma spraying that include a hot-cathode and a nozzle anode.

  3. ARc Welding (Industrial Processing Series).

    Science.gov (United States)

    ARC WELDING , *BIBLIOGRAPHIES), (*ARC WELDS, BIBLIOGRAPHIES), ALUMINUM ALLOYS, TITANIUM ALLOYS, CHROMIUM ALLOYS, METAL PLATES, SPOT WELDING , STEEL...INERT GAS WELDING , MARAGING STEELS, MICROSTRUCTURE, HEAT RESISTANT ALLOYS, HEAT RESISTANT METALS, WELDABILITY, MECHANICAL PROPERTIES, MOLYBDENUM ALLOYS, NICKEL ALLOYS, RESISTANCE WELDING

  4. Arc Heated Scramjet Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Arc Heated Scramjet Test Facility is an arc heated facility which simulates the true enthalpy of flight over the Mach number range of about 4.7 to 8 for free-jet...

  5. ALICE-ARC integration

    DEFF Research Database (Denmark)

    Anderlik, Csaba; Gregersen, Anders Rhod; Kleist, Josva;

    2008-01-01

    Data Grid Facility (NDGF). In this paper we will present our approach to integrate AliEn and ARC, in the sense that ALICE data management and job processing can be carried out on the NDGF infrastructure, using the client tools available in AliEn. The interoperation has two aspects, one is the data...

  6. Thermal Arc Spray Overview

    Science.gov (United States)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  7. Variable polarity arc welding

    Science.gov (United States)

    Bayless, E. O., Jr.

    1991-01-01

    Technological advances generate within themselves dissatisfactions that lead to further advances in a process. A series of advances in welding technology which culminated in the Variable Polarity Plasma Arc (VPPA) Welding Process and an advance instituted to overcome the latest dissatisfactions with the process: automated VPPA welding are described briefly.

  8. Gas tungsten arc welder

    Science.gov (United States)

    Christiansen, D.W.; Brown, W.F.

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  9. Motion of polar cap arcs

    Science.gov (United States)

    Hosokawa, K.; Moen, J. I.; Shiokawa, K.; Otsuka, Y.

    2011-01-01

    A statistics of motion of polar cap arcs is conducted by using 5 years of optical data from an all-sky imager at Resolute Bay, Canada (74.73°N, 265.07°E). We identified 743 arcs by using an automated arc detection algorithm and statistically examined their moving velocities as estimated by the method of Hosokawa et al. (2006). The number of the arcs studied is about 5 times larger than that in the previous statistics of polar cap arcs by Valladares et al. (1994); thus, we could expect to obtain more statistically significant results. Polar cap arcs are found to fall into two distinct categories: the By-dependent and By-independent arcs. The motion of the former arcs follows the rule reported by Valladares et al. (1994), who showed that stable polar cap arcs move in the direction of the interplanetary magnetic field (IMF) By. About two thirds of the arcs during northward IMF conditions belong to this category. The latter arcs always move poleward irrespective of the sign of the IMF By, which possibly correspond to the poleward moving arcs in the morning side reported by Shiokawa et al. (1997). At least one third of the arcs belong to this category. The By-dependent arcs tend to move faster when the magnitude of the IMF By is larger, suggesting that the transport of open flux by lobe reconnection from one polar cap compartment to the other controls their motion. In contrast, the speed of the By-independent arcs does not correlate with the magnitude of the By. The motions of both the By-dependent and By-independent arcs are most probably caused by the magnetospheric convection. Convection in the region of By-dependent arcs is affected by the IMF By, which indicates that their sources may be on open field lines or in the closed magnetosphere adjacent to the open-closed boundary, whereas By-independent arcs seem to be well on closed field lines. Hence, the magnetospheric source of the two types of arc may be different. This implies that the mechanisms causing the

  10. ALICE - ARC integration

    DEFF Research Database (Denmark)

    Anderlik, Csaba; Gregersen, Anders Rhod; Kleist, Josva;

    AliEn or Alice Environment is the Gridware developed and used within the ALICE collaboration for storing and processing data in a distributed manner. ARC (Advanced Resource Connector) is the Grid middleware deployed across the Nordic countries and gluing together the resources within the Nordic...... Data Grid Facility (NDGF). In this paper we will present our approach to integrate AliEn and ARC, in the sense that ALICE data management and job processing can be carried out on the NDGF infrastructure, using the client tools available in AliEn. The interoperation has two aspects, one is the data...... management part and the second the job management aspect. The first aspect was solved by using dCache across NDGF to handle data. dCache provides support for several data management tools (among them for xrootd the tools used by AliEn) using the so called "doors". Therefore, we will concentrate on the second...

  11. The ARCS radial collimator

    OpenAIRE

    Stone M.B.; Niedziela J.L.; Overbay M.A.; Abernathy D.L.

    2015-01-01

    We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. W...

  12. Anatomy of Intra-Oceanic Arc Systems

    Science.gov (United States)

    Stern, R. J.

    2007-12-01

    Intra-oceanic arc systems (IOAS) are ultimately embedded in orogenic belts and added to the continental crust. Reconstructing fossil IOASs in collision zones requires understanding the salient features of a typical IOAS. IOASs have the relative dimensions of tagliatelle (flat) pasta: much wider (~250 km) than thick (10-30 km), much longer (1000's of km) than wide. IOASs begin to form when subduction begins, either spontaneously (SNSZ) or by forced convergence (INSZ). For SNSZ, IOASs start as broad zones of seafloor spreading associated with subsidence of the adjacent lithosphere, whereas INSZ IOASs are built on trapped crust. IOAS magmatism manifests the evolution of its subduction zone and indirectly the breadth of the subducted ocean. Two stages in SNSZ IOAS magmato-tectonic evolution exist: infancy and maturity. Infancy lasts 5-10 Ma and results in broad zones of seafloor spreading of tholeiite/boninite; this becomes forearc for the mature IOAS and is emplaced as ophiolite during collision (subduction zone failure). Arc maturity begins with true subduction, as the subducted slab reaches depths ~130 km, focusing magmatism to begin building the magmatic arc ~200km away from the trench and allowing the forearc to cool and hydrate. Mature magmatic arcs mostly yield low-K tholeiitic and medium-K calc-alkaline magmas. Magmatic focusing begins crustal thickening beneath the magmatic arc, at ~500m/Ma for the Izu-Bonin-Mariana IOAS. No systematic compositional evolution to more LIL-enriched primitive magmas occurs once IOAS maturity is reached, except when upper plate stress regime (BAB formation, strike- slip faulting) or the nature of subducted material (more/different sediments, young oceanic crust) changes. Thickening is accompanied by processing of crust beneath the magmatic arc, with progressive differentiation into upper volcanic, middle tonalitic, and lower mafic layers, producing an increasingly effective density filter for magma ascent. Crustal layer formation

  13. Circular arc structures

    KAUST Repository

    Bo, Pengbo

    2011-07-01

    The most important guiding principle in computational methods for freeform architecture is the balance between cost efficiency on the one hand, and adherence to the design intent on the other. Key issues are the simplicity of supporting and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where geometric complexity is concentrated in the nodes, we stay with smooth surfaces and rather distribute complexity in a uniform way by allowing edges in the shape of circular arcs. We are able to achieve the simplest possible shape of nodes without interfering with known panel optimization algorithms. We study remarkable special cases of circular arc structures which possess simple supporting elements or repetitive edges, we present the first global approximation method for principal patches, and we show an extension to volumetric structures for truly threedimensional designs. © 2011 ACM.

  14. Heart Failure

    Science.gov (United States)

    ... heart failure due to systolic dysfunction. http://www.uptodate.com/home. Accessed Sept. 26, 2014. Colucci WS. ... patient with heart failure or cardiomyopathy. http://www.uptodate.com/home. Accessed Sept. 26, 2014. Colucci WS. ...

  15. Arc-preserving subsequences of arc-annotated sequences

    CERN Document Server

    Popov, Vladimir Yu

    2011-01-01

    Arc-annotated sequences are useful in representing the structural information of RNA and protein sequences. The longest arc-preserving common subsequence problem has been introduced as a framework for studying the similarity of arc-annotated sequences. In this paper, we consider arc-annotated sequences with various arc structures. We consider the longest arc preserving common subsequence problem. In particular, we show that the decision version of the 1-{\\sc fragment LAPCS(crossing,chain)} and the decision version of the 0-{\\sc diagonal LAPCS(crossing,chain)} are {\\bf NP}-complete for some fixed alphabet $\\Sigma$ such that $|\\Sigma| = 2$. Also we show that if $|\\Sigma| = 1$, then the decision version of the 1-{\\sc fragment LAPCS(unlimited, plain)} and the decision version of the 0-{\\sc diagonal LAPCS(unlimited, plain)} are {\\bf NP}-complete.

  16. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

    Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

  17. The ARCS radial collimator

    Directory of Open Access Journals (Sweden)

    Stone M.B.

    2015-01-01

    Full Text Available We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. We present here characterization of the collimator's performance and methodologies for its effective use.

  18. The ARCS radial collimator

    Science.gov (United States)

    Stone, M. B.; Niedziela, J. L.; Overbay, M. A.; Abernathy, D. L.

    2015-01-01

    We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. We present here characterization of the collimator's performance and methodologies for its effective use.

  19. Correlation methods in cutting arcs

    Energy Technology Data Exchange (ETDEWEB)

    Prevosto, L; Kelly, H, E-mail: prevosto@waycom.com.ar [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Universidad Tecnologica Nacional, Regional Venado Tuerto, Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina)

    2011-05-01

    The present work applies similarity theory to the plasma emanating from transferred arc, gas-vortex stabilized plasma cutting torches, to analyze the existing correlation between the arc temperature and the physical parameters of such torches. It has been found that the enthalpy number significantly influence the temperature of the electric arc. The obtained correlation shows an average deviation of 3% from the temperature data points. Such correlation can be used, for instance, to predict changes in the peak value of the arc temperature at the nozzle exit of a geometrically similar cutting torch due to changes in its operation parameters.

  20. Systems failure.

    OpenAIRE

    Macleod, Anna

    1998-01-01

    Systems Failure A solo exhibition of new work by Anna Macleod developed in conversation with curator Liz Burns. The Dock, Carrick on Shannon, Co Leitrim. Ireland. 12th February – 17th April 2010. The works for the exhibition Systems Failure include drawings, prints and small constructions that examine the delicate balance that exists between need and aspects of failure rooted in the relationship between humanity and land use. The work seeks to question the relationship between scient...

  1. Alternating-Polarity Arc Welding

    Science.gov (United States)

    Schwinghamer, R. J.

    1987-01-01

    Brief reversing polarity of welding current greatly improves quality of welds. NASA technical memorandum recounts progress in art of variable-polarity plasma-arc (VPPA) welding, with emphasis on welding of aluminum-alloy tanks. VPPA welders offer important advantages over conventional single-polarity gas/tungsten arc welders.

  2. Characteristics of Arcs Between Porous Carbon Electrodes

    OpenAIRE

    Carvou, Erwann; Le Garrec, Jean-Luc; Mitchell, Brian

    2013-01-01

    International audience; Arcs between carbon electrodes present some specific differences compared with metallic arcs. The arc voltage is higher, but does not attain a stable value displaying large fluctuations. Indeed, the arcs are produced by the direct sublimation of the electrodes, without passing through a molten phase. The arc production is also facilitated by both circuit breaking and electric field breakdown. In this paper, arcing has been examined under various conditions (voltage, cu...

  3. Rocket nozzle thermal shock tests in an arc heater facility

    Science.gov (United States)

    Painter, James H.; Williamson, Ronald A.

    1986-01-01

    A rocket motor nozzle thermal structural test technique that utilizes arc heated nitrogen to simulate a motor burn was developed. The technique was used to test four heavily instrumented full-scale Star 48 rocket motor 2D carbon/carbon segments at conditions simulating the predicted thermal-structural environment. All four nozzles survived the tests without catastrophic or other structural failures. The test technique demonstrated promise as a low cost, controllable alternative to rocket motor firing. The technique includes the capability of rapid termination in the event of failure, allowing post-test analysis.

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

    Directory of Open Access Journals (Sweden)

    Dingjian Ye

    2013-01-01

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

  5. Controllability of arc jet from arc horns with slits. Slit tsuki arc horn no arc jet seigyo tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Sunabe, K.; Inaba, T.; Fukagawa, H. (Central Research Institute of Electric Power Industry, Tokyo (Japan)); Kito, Y. (Nagoya University, Nagoya (Japan))

    1993-09-20

    To improve the corona discharge characteristics, test preparation was made of hollow rod form horns with slits for the overhead power transmission line use. Two types of horn electrode were prepared. The first horn electrode is of a hollow hemisphere fitted with and divided by slits on its tip. The second horn electrode is the first one which is further fitted with rod form electrode at the center of its tip. In experiment, relation was obtained between the deflection angle of arc jet and arc current, electrode diameter, etc., through an observation of arc jet by high speed camera. Melting loss of electrode was also made clear. The following knowledge was obtained: For the first horn electrode, the deflection angle can be limited to a narrow range by a division with slits, e.g., within 30 degrees under the condition of 5kA in arc current, 4 in number of sectors and 200mm in diameter. For the second horn electrode, the deflection angle can be limited to within 20 degrees under the condition of 5kA in arc current and 4 in number of sectors. The arc current is also limited to below 5kA by an addition of 50mm diameter central electrode. As a conclusion for the first electrode, the arc jet control characteristics excels in the stronger arc current range than 5kA, while for the second electrode, they are effective in the weaker arc current range than 5kA. 6 refs., 19 figs., 1 tab.

  6. Arc spot grouping: An entanglement of arc spot cells

    Energy Technology Data Exchange (ETDEWEB)

    Kajita, Shin, E-mail: kajita.shin@nagoya-u.jp [EcoTopia Science Institute, Nagoya University, Nagoya 464-8603 (Japan); Hwangbo, Dogyun; Ohno, Noriyasu [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Tsventoukh, Mikhail M. [Lebedev Physical Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Barengolts, Sergey A. [Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation)

    2014-12-21

    In recent experiments, clear transitions in velocity and trail width of an arc spot initiated on nanostructured tungsten were observed on the boundary of the thick and thin nanostructured layer regions. The velocity of arc spot was significantly decreased on the thick nanostructured region. It was suggested that the grouping decreased the velocity of arc spot. In this study, we try to explain the phenomena using a simple random walk model that has properties of directionality and self-avoidance. And grouping feature was added by installing an attractive force between spot cells with dealing with multi-spots. It was revealed that an entanglement of arc spot cells decreased the spot velocity, and spot cells tend to stamp at the same location many times.

  7. Convergent evolution of the arginine deiminase pathway: the ArcD and ArcE arginine/ornithine exchangers.

    Science.gov (United States)

    Noens, Elke E E; Lolkema, Juke S

    2017-02-01

    The arginine deiminase (ADI) pathway converts L-arginine into L-ornithine and yields 1 mol of ATP per mol of L-arginine consumed. The L-arginine/L-ornithine exchanger in the pathway takes up L-arginine and excretes L-ornithine from the cytoplasm. Analysis of the genomes of 1281 bacterial species revealed the presence of 124 arc gene clusters encoding the pathway. About half of the clusters contained the gene encoding the well-studied L-arginine/L-ornithine exchanger ArcD, while the other half contained a gene, termed here arcE, encoding a membrane protein that is not a homolog of ArcD. The arcE gene product of Streptococcus pneumoniae was shown to take up L-arginine and L-ornithine with affinities of 0.6 and 1 μmol/L, respectively, and to catalyze metabolic energy-independent, electroneutral exchange. ArcE of S. pneumoniae could replace ArcD in the ADI pathway of Lactococcus lactis and provided the cells with a growth advantage. In contrast to ArcD, ArcE catalyzed translocation of the pathway intermediate L-citrulline with high efficiency. A short version of the ADI pathway is proposed for L-citrulline catabolism and the presence of the evolutionary unrelated arcD and arcE genes in different organisms is discussed in the context of the evolution of the ADI pathway.

  8. On arc efficiency in gas tungsten arc welding

    Directory of Open Access Journals (Sweden)

    Nils Stenbacka

    2013-12-01

    Full Text Available The aim of this study was to review the literature on published arc efficiency values for GTAW and, if possible, propose a narrower band. Articles between the years 1955 - 2011 have been found. Published arc efficiency values for GTAW DCEN show to lie on a wide range, between 0.36 to 0.90. Only a few studies covered DCEP - direct current electrode positive and AC current. Specific information about the reproducibility in calorimetric studies as well as in modeling and simulation studies (considering that both random and systematic errors are small was scarce. An estimate of the average arc efficiency value for GTAW DCEN indicates that it should be about 0.77. It indicates anyway that the GTAW process with DCEN is an efficient welding method. The arc efficiency is reduced when the arc length is increased. On the other hand, there are conflicting results in the literature as to the influence of arc current and travel speed.

  9. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008275 Relationship of calcineure in mRNA level in peripheral blood and cardiac muscle of patients with heart failure.WANG Mengmeng(王萌萌),et al.Dept Cardiol,Shandong Prov Hosp,Shandong Univ,Jinan 250021.Chin Cir J 2008;23(2):113-116.Objective To study the relationship of calcineurin mRNA level between peripheral lymphocytes and cardiac muscles of patients with chronic heart failure.Methods

  10. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008037 Factors associated with efficacy of cardiac resynchronization therapy for patients with congestive heart failure. SHI Haoying(史浩颖), et al. Dept Cardiol, Zhongshan Hosp Fudan Univ, Shanghai 200032. Chin J Cardiol 2007;35(12):1099-1163. Objective The efficacy of cardiac resynchronization therapy (CRT) in patients with congestive heart failure and the potential factors associated with responder or nonresponder were investigated. Methods Fifty

  11. Arc of opportunity.

    Science.gov (United States)

    Delaney, Adam Vai

    2011-07-01

    Born in Port Moresby, Papua New Guinea, the author had a 20 year career in diplomacy, political affairs, and development policy analysis at the Pacific Islands Forum, the United Nations in New York; the Prime Minister's Department in Papua New Guinea (PNG) and in the Foreign Ministry of PNG. He has also been involved in theatre for over a decade in PNG, and participated in a three-month program at the Eugene O'Neill Theatre Center in Connecticut, USA. He is currently the Business Development Manager at the Torres Strait Regional Authority (Commonwealth) on Thursday Island. Since 1975 the Australian government's overseas development policy has supported various sectoral programs in its neighbouring countries, in particular Papua New Guinea and the Solomon Islands. The "creative" field has not been prominent in this strategy. While natural resources and the sports sectors have gained much greater attention, in terms of being viable international commercial enterprises, the arts, have remained stagnant. In this paper the need for joint programs genuinely supporting "wellbeing" and promoting social enterprise throughout the "arc of opportunity" is described to harness Melanesian creativity to compete successfully in world-markets, starting with penetration of the largest economy at its door-step: Australia.

  12. STUDY ON THE PRESSURE IN PLASMA ARC

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The axial pressure in plasma arc is measured under different conditions. The effects of the parameters, such as welding current, plasma gas flow rate, electrode setback and arc length, on the pressure in plasma arc are investigated and quantitative analyzed to explain the relationship between the quality of weld and the matching of parameters in plasma arc welding process.

  13. Numerical Simulation for Arc Windshields of Aircrafts Subjected to Bird Impact

    Institute of Scientific and Technical Information of China (English)

    Yao Xiaohu; Zhao Longmao; Liu Xiaoming

    2004-01-01

    A finite element model including full-scale circular arc windshield glass and the relative parts of the military plane is established in this paper. The model is analyzed by using an explicit element code LS-DYNA3D for analyzing the nonlinear dynamic response of structures. The data in aspects of displacement, strain, stress and contact force in the process of deformation are obtained. The deformation and failure mechanism of circular arc windshield glass are discussed. The possible location at which failure may take place is given. The valuable data are provided for designing,researching and producing new windshields with high crashworthiness.

  14. School failure.

    Science.gov (United States)

    Dworkin, P H

    1989-04-01

    Numerous factors may contribute to a child's failure to learn. Certain causes of school failure, such as specific learning disabilities, mental retardation, sensory impairment, and chronic illness may be regarded as intrinsic characteristics of the child. Other causes, such as family dysfunction, social problems, and ineffective schooling, are characteristics of the child's environment. Still other influences on school performance, such as temperamental dysfunction, attention deficits, and emotional illness, may be viewed as the consequence of the interaction between the child and his or her environment. The reasons for a child's school failure must not be considered in isolation but rather within the context of social and environmental circumstances. Evaluation must consider the myriad of reasons for a child's school failure and attempt to identify "clusters" of adverse influences on school performance. Detailed information must be sought from the student, parents, and school system through the history and physical examination. Questionnaires are useful in data gathering. Ancillary methods of assessment that may be of value include neurodevelopmental screening and laboratory studies. Further investigations and referrals, particularly psychoeducational evaluation, are of major importance. Traditional roles of the pediatrician in school failure include the treatment of underlying medical conditions, counseling, the coordination of further investigations and referrals, and the facilitation of communication with community services and resources. Participation with other disciplines in the development of a child's educational plan is feasible and useful.

  15. High pressure neon arc lamp

    Science.gov (United States)

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  16. Heart failure

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    970284 Effects of enalapril on heart rate variabilityin patients with congestive heart failure. ZHANGYouhua(章友华), et a1. Dept Cardiol, Cardiovasc Instit& Fuwai Hosp, CAMS & PUMC, Beijing, 100037. ChinCir J 1996; 11(2): 729-732.

  17. Respiratory failure

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    970318 A study on evoked potentials in cor pul-monale patients with chronic respiratory failure.QIAO Hui(乔慧), et al. Beijing Neurosurg Instit,Beijing, 100050. Chin J Geriatr 1997; 16(1): 43-45. Objective: Evoked protential was used to detect thechange of brain function in cor pulmonale patients with

  18. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    2009170 Curcumin attenuates left ventricular dysfunction and remodeling in rabbits with chronic heart failure. TANG Yanhong(唐艳红),et al.Dept Cardiol,Renmin Hosp,Wuhan Univ,Wuhan 430060.Chin J Cardiol,2009;37(3):262-267.

  19. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008411 Expression of S100B during heart failure in rats. JIANG Zhenni(蒋珍妮), et al. Dept Cardiol, 2nd Affili Hosp, Zhejiang Univ, Coll Med Hangzhou 310009. Chin J Emerg Med 2008;17(5):475-478. Objective To evaluate the value of S100B gene on cardiovascular remodeling in rats with abdominal aorta coarctation.

  20. Failure Modes

    DEFF Research Database (Denmark)

    Jakobsen, K. P.; Burcharth, H. F.; Ibsen, Lars Bo;

    1999-01-01

    The present appendix contains the derivation of ten different limit state equations divided on three different failure modes. Five of the limit state equations can be used independently of the characteristics of the subsoil, whereas the remaining five can be used for either drained or undrained...

  1. Arc detector system for extraction switches in LHC CERN

    CERN Document Server

    Dahlerup-Petersen, K; Kuper, E; Ovchar, V; Zverev, S

    2006-01-01

    The opening switches, which will be used in case of quenches or other failures in CERN’s future LHC collider to extract the large amounts of energy stored in the magnetic field of the superconducting chains of main dipoles (8 chains with 1350 MJ each) and main quadrupoles (16 chains with about 24 MJ each) consist of an array of series/parallel connected, electro-mechanical D.C. breakers, specifically designed for this particular application. During the opening process the magnet excitation current is transferred from the cluster of breakers to extraction resistors for rapid de-excitation of the magnet chain. An arc detector has been developed in order to facilitate the determination of the need for maintenance interventions on the switches. The paper describes the arc detector and highlight results from operation of the detector with a LHC pilot extraction...

  2. Gas Tungsten Arc Welding and Plasma Arc Cutting. Teacher Edition.

    Science.gov (United States)

    Fortney, Clarence; And Others

    This welding curriculum guide treats two topics in detail: the care of tungsten electrodes and the entire concept of contamination control and the hafnium electrode and its importance in dual-air cutting systems that use compressed shop air for plasma arc cutting activities. The guide contains three units of instruction that cover the following…

  3. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930150 Epidermal growth factor and its recep-tor in the renal tissue of patients with acute re-nal failure and normal persons.LIU Zhihong(刘志红),et al.Jinling Hosp,Nanjing,210002.Natl Med J China 1992;72(10):593-595.Epidermal growth factor(EGF)and its receptor(EGF-R)were identified by immunohis-tochemical method(4 layer PAP)in the renaltissue specimens obtained from 11 normal kid-neys and 17 cases of acute renal failure(ARF).The quantitative EGF and EGF-R in the tissuewere expressed as positive tubules per mm~2.The amount of EGF and EGF-R in renal tissue

  4. Renal failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008463 Protective effect of recombination rat augmenter of liver regeneration on kidney in acute renal failure rats. TANG Xiaopeng(唐晓鹏), et al. Dept Nephrol, 2nd Affili Hosp Chongqing Med Univ, Chongqing 400010.Chin J Nephrol 2008;24(6):417-421. Objective To investigate the protective effects of recombination rat augmenter of liver regeneration (rrALR) on tubular cell injury and renal dysfunction

  5. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    2005186 The diagnostic application of bedside measurement of plasma brain natriuretic in patients with heart failure. SHAO Le-wen (邵乐文) , Advanced Ward Dept, 1st Hosp, Med Sch, Zhejiang Univ, Hangzhou 310003. Chin J Intern Med, 2005;44(2): 99-101. Objective: To investigate differential diagnosis value of ultra-rapid bedside measurement of brain na-triuretic peptide (BNP) in patients with dyspnea.

  6. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    2010316 Tissue doppler imaging observation on effect of long-term use of gingko biloba tabtet on left ventricular function in patients with chronic heart failure. ZHANG Hui(张辉),et al. Dept Cardiovasc Med, 2nd Hosp, Hebei Med Univ,Shijiazhuang 050000. Chin J Integr Tradit & West Med 2010;30(5):478-481. Objective To quantitatively observe the effect of long-term

  7. Heart failure

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    920647 Comparative effects of commonvasodilators on experimental cardiac fai-lure. LI Zhijian (李志坚), et al. Dept Cardiol,2nd Hosp, Tianjin Med Coll. Tianjin Med J1992; 20(8): 456-458. A 9×9 latin square design was employed forcomparing the effects of (1) placebo, (2) nitr-oprusside, (3) phentolamine, (4) isosorbide dini-trate. (5) captopril, (6) captopril-isosorbide

  8. Hooded arc ion-source

    CERN Multimedia

    1972-01-01

    The positioning system for the hooded arc ion-source, shown prior to mounting, consists of four excentric shafts to locate the ion-source and central electrodes. It will be placed on the axis of the SC and introduced into the vacuum tank via the air locks visible in the foreground.

  9. Vacuum Gas Tungsten Arc Welding

    Science.gov (United States)

    Weeks, J. L.; Todd, D. T.; Wooten, J. R.

    1997-01-01

    A two-year program investigated vacuum gas tungsten arc welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. After a vacuum chamber and GTAW power supply were modified, several difficult-to-weld materials were studied and key parameters developed. Finally, Incoloy 903 weld overlays were produced without microfissures.

  10. Rotating Drive for Electrical-Arc Machining

    Science.gov (United States)

    Fransen, C. D.

    1986-01-01

    Rotating drive improves quality of holes made by electrical-arc machining. Mechanism (Uni-tek, rotary head, or equivalent) attached to electrical-arc system. Drive rotates electrode as though it were mechanical drill, while an arc disintegrates metal in workpiece, thereby creating hole. Rotating electrode method often used in electric-discharge machining. NASA innovation is application of technique to electrical-arc machining.

  11. STRUVE arc and EUPOS® stations

    Science.gov (United States)

    Lasmane, Ieva; Kaminskis, Janis; Balodis, Janis; Haritonova, Diana

    2013-04-01

    The Struve Geodetic Arc was developed in Years 1816 to 1855, 200 years ago. Historic information on the points of the Struve Geodetic Arc are included in the UNESCO World Heritage list in 2005. Nevertheless, the sites of many points are still not identified nor included in the data bases nowadays. Originally STRUVE arc consisted of 258 main triangles with 265 triangulation points. Currently 34 of the original station points are identified and included in the in the UNESCO World Heritage list. identified original measurement points of the Meridian Arc are located in Sweden (7 points), Norway (15), Finland (83), Russia (1), Estonia (22), Latvia (16), Lithuania (18), Belorussia (28), Ukraine (59) and Moldova (27). In Year 2002 was initiated another large coverage project - European Position Determination System "EUPOS®". Currently there are about 400 continuously operating GNSS (Global Navigation Satellite Systems) stations covering EU countries Estonia, Latvia, Lithuania, Poland, Czech Republic, Slovakia, Hungary, Bulgaria, Romania and East European countries Ukraine and Moldavia. EUPOS® network is a ground based GNSS augmentation system widely used for geodesy, land surveying, geophysics and navigation. It gives the opportunity for fast and accurate position determination never available before. It is an honorable task to use the EUPOS® system for research of the Struve triangulation former sites. Projects with Struve arc can popularize geodesy, geo-information and its meaning in nowadays GIS and GNSS systems. Struve Arc and its points is unique cooperation cross-border object which deserve special attention because of their natural beauty and historical value for mankind. GNSS in geodesy discovers a powerful tool for the verification and validation of the height values of geodetic leveling benchmarks established historically almost 200 years ago. The differential GNSS and RTK methods appear very useful to identify vertical displacement of landscape by means of

  12. Magnification Bias in Gravitational Arc Statistics

    Energy Technology Data Exchange (ETDEWEB)

    Caminha, G. B. [Rio de Janeiro, CBPF; Estrada, J. [Fermilab; Makler, M. [Rio de Janeiro, CBPF

    2013-08-29

    The statistics of gravitational arcs in galaxy clusters is a powerful probe of cluster structure and may provide complementary cosmological constraints. Despite recent progresses, discrepancies still remain among modelling and observations of arc abundance, specially regarding the redshift distribution of strong lensing clusters. Besides, fast "semi-analytic" methods still have to incorporate the success obtained with simulations. In this paper we discuss the contribution of the magnification in gravitational arc statistics. Although lensing conserves surface brightness, the magnification increases the signal-to-noise ratio of the arcs, enhancing their detectability. We present an approach to include this and other observational effects in semi-analytic calculations for arc statistics. The cross section for arc formation ({\\sigma}) is computed through a semi-analytic method based on the ratio of the eigenvalues of the magnification tensor. Using this approach we obtained the scaling of {\\sigma} with respect to the magnification, and other parameters, allowing for a fast computation of the cross section. We apply this method to evaluate the expected number of arcs per cluster using an elliptical Navarro--Frenk--White matter distribution. Our results show that the magnification has a strong effect on the arc abundance, enhancing the fraction of arcs, moving the peak of the arc fraction to higher redshifts, and softening its decrease at high redshifts. We argue that the effect of magnification should be included in arc statistics modelling and that it could help to reconcile arcs statistics predictions with the observational data.

  13. Laboratory experiments on arc deflection and instability

    Energy Technology Data Exchange (ETDEWEB)

    Zweben, S.; Karasik, M.

    2000-03-21

    This article describes experiments on arc deflection instability carried out during the past few years at the Princeton University Plasma Physics Laboratory (PPPL). The approach has been that of plasma physicists interested in arcs, but they believe these results may be useful to engineers who are responsible for controlling arc behavior in large electric steel furnaces.

  14. Making Conductive Polymers By Arc Tracking

    Science.gov (United States)

    Daech, Alfred F.

    1992-01-01

    Experimental technique for fabrication of electrically conductive polymeric filaments based on arc tracking, in which electrical arc creates conductive carbon track in material that initially was insulator. Electrically conductive polymeric structures made by arc tracking aligned along wire on which formed. Alignment particularly suited to high conductivity and desirable in materials intended for testing as candidate superconductors.

  15. Heart failure - tests

    Science.gov (United States)

    CHF - tests; Congestive heart failure - tests; Cardiomyopathy - tests; HF - tests ... the best test to: Identify which type of heart failure (systolic versus diastolic, valvular) Monitor your heart failure ...

  16. Tectonomagmatism in continental arcs: evidence from the Sark arc complex

    Science.gov (United States)

    Gibbons, Wes; Moreno, Teresa

    2002-07-01

    The island of Sark (Channel Islands, UK) exposes syntectonic plutons and country rock gneisses within a Precambrian (Cadomian) continental arc. This Sark arc complex records sequential pulses of magmatism over a period of 7 Ma (ca. 616-609 Ma). The earliest intrusion (ca. 616 Ma) was a composite sill that shows an ultramafic base overlain by a magma-mingled net vein complex subsequently deformed at near-solidus temperatures into the amphibolitic and tonalitic Tintageu banded gneisses. The deformation was synchronous with D 2 deformation of the paragneissic envelope, with both intrusion and country rock showing flat, top-to-the-south LS fabrics. Later plutonism injected three homogeneous quartz diorite-granodiorite sheets: the Creux-Moulin pluton (150-250 m; ca. 614 Ma), the Little Sark pluton (>700 m; 611 Ma), and the Northern pluton (>500 m; 609 Ma). Similar but thinner sheets in the south (Derrible-Hogsback-Dixcart) and west (Port es Saies-Brecqhou) are interpreted as offshoots from the Creux-Moulin pluton and Little Sark pluton, respectively. All these plutons show the same LS fabric seen in the older gneisses, with rare magmatic fabrics and common solid state fabrics recording syntectonic crystallisation and cooling. The cooling rate increased rapidly with decreasing crystallisation age: >9 Ma for the oldest intrusion to cool to lower amphibolite conditions, 7-8 Ma for the Creux Moulin pluton, 5-6 Ma for the Little Sark pluton, and 10 -14 s -1) that focussed extensional deformation into the Sark area. The increased rates of extension allowed ingress of the subsequent quartz diorite-granodiorite sheets, although strain rate slowly declined as the whole complex cooled during exhumation. The regional architecture of syntectonic Cadomian arc complexes includes flat-lying "Sark-type" and steep "Guernsey-type" domains produced synchronously in shear zone networks induced by oblique subduction: a pattern seen in other continental arcs such as that running from Alaska

  17. A Contribution to Arc Length Discussion

    Directory of Open Access Journals (Sweden)

    Stephan Egerland

    2015-09-01

    Full Text Available Abstract An investigation was raising the question: "What does 'arc length' mean?" Actually, it is considered expressing a kind of natural relationship between arc voltage and arc column shape. Statements such as "The higher the voltage the longer the arc" or "The arc voltage proves approximately proportional to the arc length", are frequently noticed in this conjunction. However, the author suggests that there is no general possibility of describing 'arc length' over the whole welding process range. Instances are represented in this paper, showing both theoretical attempts of definition and practical observations. This paper intends to contribute to a serious discussion of something trivial, indeed very well-known or used among welding experts, but actually yet hardly understood, at least as when it comes to closer examination

  18. Zircon Recycling in Arc Intrusions

    Science.gov (United States)

    Miller, J.; Barth, A.; Matzel, J.; Wooden, J.; Burgess, S.

    2008-12-01

    Recycling of zircon has been well established in arc intrusions and arc volcanoes, but a better understanding of where and how zircons are recycled can help illuminate how arc magma systems are constructed. To that end, we are conducting age, trace element (including Ti-in-zircon temperatures; TzrnTi) and isotopic studies of zircons from the Late Cretaceous (95-85 Ma) Tuolumne Intrusive Suite (TIS) in the Sierra Nevada Batholith (CA). Within the TIS zircons inherited from ancient basement sources and/or distinctly older host rocks are uncommon, but recycled zircon antecrysts from earlier periods of TIS-related magmatism are common and conspicuous in the inner and two most voluminous units of the TIS, the Half Dome and Cathedral Peak Granodiorites. All TIS units have low bulk Zr ([Zr]825°C), [Zr] in the TIS is a factor of 2 to 3 lower than saturation values. Low [Zr] in TIS rocks might be attributed to a very limited supply of zircon in the source, by disequilibrium melting and rapid melt extraction [1], by melting reactions involving formation of other phases that can incorporate appreciable Zr [2], or by removal of zircon at an earlier stage of magma evolution. Based on a preliminary compilation of literature data, low [Zr] is common to Late Cretaceous N.A. Cordilleran granodioritic/tonalitic intrusions (typically Tzrnsat [3]. A corollary is that slightly older zircon antecrysts that are common in the inner units of the TIS could be considered inherited if they are derived from remelting of slightly older intrusions. Remelting at such low temperatures in the arc would require a source of external water. Refs: [1] Sawyer, J.Pet 32:701-738; [2] Fraser et al, Geology 25:607-610; [3] Harrison et al, Geology 35:635- 638

  19. IMPROVEMENTS ON THE ARC-LENGTH-TYPE METHOD

    Institute of Scientific and Technical Information of China (English)

    LI Yuanqi; SHEN Zuyan

    2004-01-01

    Arc-length-type and energy-type methods are two main strategies used in structural nonlinear tracing analysis, but the former is widely used due to the explicitness and clarity in conception,as well as the convenience and reliability in calculation. It is very important to trace the complete loaddeflection path in order to know comprehensively the characteristics of structures subjected to loads.Unfortunately, the nonlinear analysis techniques are only workable for tracing the limit-point-type equilibrium path. For the bifurcation-point-type path, most of them cannot secure a satisfactory result.In this paper, main arc-length-type methods are reviewed and compared, and the possible reasons of failures in tracing analysis are briefly discussed. Some improvements are proposed, a displacement perturbation method and a force perturbation method are presented for tracing the bifurcation-pointtype paths. Finally, two examples are analyzed to verify the ideas, and some conclusions are drawn with respect to the arc-length-type methods.

  20. Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.

    Energy Technology Data Exchange (ETDEWEB)

    Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay

    2012-01-01

    Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.

  1. H_2O and CO_2 in magmas from the Mariana arc and back arc systems

    OpenAIRE

    Newman, Sally; Stolper, Edward; STERN, Robert

    2000-01-01

    We examined the H2O and CO2 contents of glasses from lavas and xenoliths from the Mariana arc system, an intraoceanic convergent margin in the western Pacific, which contains an active volcanic arc, an actively spreading back arc basin, and active behind-the-arc cross-chain volcanoes. Samples include (1) glass rims from Mariana arc, Mariana trough, and cross-chain submarine lavas; (2) glass inclusions in arc and trough phenocrysts; and (3) glass inclusions from a gabbro + anorthosite xenolith...

  2. Arc Root Attachment on the Anode Surface of Arc Plasma Torch Observed with a Novel Method

    Institute of Scientific and Technical Information of China (English)

    PAN Wen-Xia; LI Teng; MENG Xian; CHEN Xi; WU Cheng-Kang

    2005-01-01

    @@ The arc-root attachment on the anode surface of a dc non-transferred arc plasma torch has been successfullyobserved using a novel approach. A specially designed copper mirror with a boron nitride film coated on itssurface central-region is employed to avoid the effect of intensive light emitted from the arc column upon theobservation of weakly luminous arc root. It is found that the arc-root attachment is diffusive on the anode surfaceof the argon plasma torch, while constricted arc roots often occur when hydrogen or nitrogen is added into argonas the plasma-forming gas.

  3. Reappraisal of the Arc-Arc Collision in Taiwan

    Directory of Open Access Journals (Sweden)

    Tetsuzo Seno and Yoshiaki Kawanishi

    2009-01-01

    Full Text Available Al though it is evident that Taiwan has been formed by the collision of the west-facing Luzon arc with the Eurasian continental mar gin, _ main a lot of enigmas in this collision. The major ones are: (1 a trans form fault presently connecting the Manila and Ryukyu Trenches in the Philippine Sea _ Eurasia relative motion direction is missing, and in stead, the Ryukyu Trench ex tends near off shore E. Tai wan, (2 the western edge of the intermediate-depth seismicity associated with We pro pose a new model of the collision in Tai wan to re solve these enigmas, assuming that the southern Ryukyu forearc was mi grating to the south west with respect to Eurasia for the past several m.y. and the Luzon arc has been colliding with this actively migrating Ryukyu forearc. The northern most Luzon arc is divided into two parts by the NNW line directing along the Philippine Sea - Ryukyu forearc motion from its initial intersection point with the Ryukyu Trench; the part west of this line has been obducted on the Ryukyu forearc-Eurasian mar gin, producing the collision orogen in Taiwan, and the part east of it has been subducted beneath the Ryukyu forearc. This evolutionary scenario resolves enigmas (1 and (2 kinematically. This model also predicts that the South China Sea slab has to be torn by the west ward component of the motion of the subducting Philippine Sea slab to Eurasia. This would have brought large lateral compression in the shallow portion of the Philippine Sea slab at its western border, which might lead to buck ling of the slab causing the ob served undulated gravity anomaly.

  4. Respiratory failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930118 Facial or nasal mask pressure supportventilation in managing acute exacerbation ofchronic respiratory failure in COPD patients.CHEN Rongchang(陈荣昌),et al.GuangzhouInstit Respir Dis,Guangzhou 510120.Chin Tu-berc & Respir Dis 1992;15(5)285-287.Eleven COPD patients(age:65±9 yrs)withacute exacerbation of chronic respiratory failure(PaCO2 11.3±1.1kPa)were treated with maskpressure support ventilation,another 10 similarpatients(age:68±12yrs)served as controls.Bi-PAP ventilator was used with the followingmodifications:(1)Non-rehreathing valve set-in proximal to mask;(2)5 LPM oxygen flow de-livered into mask to reduce the dead space ef-fect.Mask ventilation was given 2-3 hours ev-ery time and 1-2 times daily for 7 days.Syn-

  5. Programming ArcGIS with Python cookbook

    CERN Document Server

    Pimpler, Eric

    2015-01-01

    Programming ArcGIS with Python Cookbook, Second Edition, is written for GIS professionals who wish to revolutionize their ArcGIS workflow with Python. Whether you are new to ArcGIS or a seasoned professional, you almost certainly spend time each day performing various geoprocessing tasks. This book will teach you how to use the Python programming language to automate these geoprocessing tasks and make you a more efficient and effective GIS professional.

  6. Miniaturized cathodic arc plasma source

    Science.gov (United States)

    Anders, Andre; MacGill, Robert A.

    2003-04-15

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  7. Boxicity of Circular Arc Graphs

    OpenAIRE

    Bhowmick, Diptendu; Chandran, L. Sunil

    2008-01-01

    A $k$-dimensional box is the cartesian product $R_1 \\times R_2 \\times ... \\times R_k$ where each $R_i$ is a closed interval on the real line. The {\\it boxicity} of a graph $G$, denoted as $box(G)$, is the minimum integer $k$ such that $G$ can be represented as the intersection graph of a collection of $k$-dimensional boxes: that is two vertices are adjacent if and only if their corresponding boxes intersect. A circular arc graph is a graph that can be represented as the intersection graph of ...

  8. Electrode Evaporation Effects on Air Arc Behavior

    Institute of Scientific and Technical Information of China (English)

    LI Xingwen; CHEN Degui; LI Rui; WU Yi; NIU Chunping

    2008-01-01

    A numerical study of the effects of copper and silver vapours on the air arc behavior is performed. The commercial software FLUENT is adapted and modified to develop a two-dimensional magneto-hydrodynamic (MHD) models of arc with the thermodynamic properties and transport coefficients, net emission coefficient for the radiation model of 99% ai-1% Cu, 99% air-1% Ag, and pure air, respectively. The simulation result demonstrates that vaporization of the electrode material may cool the arc center region and reduce the arc velocity. The effects of Ag vapour are stronger compared to those of Cu vapour.

  9. The Team Orienteering Arc Routing Problem

    OpenAIRE

    Archetti, Claudia; Speranza, M. Grazia; Corberan, Angel; Sanchís Llopis, José María; Plana, Isaac

    2014-01-01

    The team orienteering arc routing problem (TOARP) is the extension to the arc routing setting of the team orienteering problem. In the TOARP, in addition to a possible set of regular customers that have to be serviced, another set of potential customers is available. Each customer is associated with an arc of a directed graph. Each potential customer has a profit that is collected when it is serviced, that is, when the associated arc is traversed. A fleet of vehicles with a given maximum trav...

  10. Class `E` protective headwear: electric arc exposure

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.

    1997-04-01

    A series of tests were conducted using electric arcs under laboratory conditions to determine what, if any, damages can be inflicted upon class `E` hard hats. Ten hard hats were subjected to different levels of arc exposure to see if the hat would ignite, melt, drip, stick to the head, etc. It was noted that there is no standard on hard hat exposure to an electric arc. It was recommended that the CSA committee revise the protective headwear standard to include a requirement for flame/arc resistance, including specification of pass/fail criteria. 1 tab., 3 figs.

  11. Metals purification by improved vacuum arc remelting

    Science.gov (United States)

    Zanner, Frank J.; Williamson, Rodney L.; Smith, Mark F.

    1994-12-13

    The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

  12. Feedback Linearization Based Arc Length Control for Gas Metal Arc Welding

    DEFF Research Database (Denmark)

    Thomsen, Jesper Sandberg

    2005-01-01

    In this paper a feedback linearization based arc length controller for gas metal arc welding (GMAW) is described. A nonlinear model describing the dynamic arc length is transformed into a system where nonlinearities can be cancelled by a nonlinear state feedback control part, and thus, leaving only...

  13. ATLAS DDM integration in ARC

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Cameron, David; Ellert, Mattias;

    2008-01-01

    The Nordic Data Grid Facility (NDGF) consists of Grid resources running ARC middleware in Denmark, Finland, Norway and Sweden. These resources serve many virtual organisations and contribute a large fraction of total worldwide resources for the ATLAS experiment, whose data is distributed and mana......The Nordic Data Grid Facility (NDGF) consists of Grid resources running ARC middleware in Denmark, Finland, Norway and Sweden. These resources serve many virtual organisations and contribute a large fraction of total worldwide resources for the ATLAS experiment, whose data is distributed...... and managed by the DQ2 software. Managing ATLAS data within NDGF and between NDGF and other Grids used by ATLAS (the Enabling Grids for E-sciencE Grid and the Open Science Grid) presents a unique challenge for several reasons. Firstly, the entry point for data, the Tier 1 centre, is physically distributed...... outside the worker node environment. Also, the service used for cataloging the location of data files is different from otherGrids but must still be useable by DQ2 and ATLAS users to locate data within NDGF. This paper presents in detail how we solve these issues to allow seamless access worldwide to data...

  14. Acute Kidney Failure

    Science.gov (United States)

    ... out of balance. Acute kidney failure — also called acute renal failure or acute kidney injury — develops rapidly over ... 2015. Palevsky PM. Definition of acute kidney injury (acute renal failure). http://www.uptodate.com/home. Accessed April ...

  15. Kidney (Renal) Failure

    Science.gov (United States)

    ... How is kidney failure treated? What is kidney (renal) failure? The kidneys are designed to maintain proper fluid ... marrow and strengthen the bones. The term kidney (renal) failure describes a situation in which the kidneys have ...

  16. Acute kidney failure

    Science.gov (United States)

    Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute ... There are many possible causes of kidney damage. They include: ... cholesterol (cholesterol emboli) Decreased blood flow due to very ...

  17. Living with Heart Failure

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Living With Heart Failure Currently, heart failure has no cure. You'll ... avoid harmful side effects. Take Steps To Prevent Heart Failure From Getting Worse Certain actions can worsen your ...

  18. Classes of Heart Failure

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Classes of Heart Failure Updated:Sep 28,2016 Doctors usually classify patients' ... Blood Pressure Tracker Find additional helpful resources here Heart Failure • Home • About Heart Failure Introduction Types of Heart ...

  19. About Heart Failure

    Science.gov (United States)

    ... talk about your health and the medicines About Heart Failure Heart failure is a disease where the heart cannot do ... very important for your health. common causes of heart failure are diseases or conditions that damage the heart. ...

  20. What Is Heart Failure?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. What Is Heart Failure? Heart failure is a condition in which the heart can' ... force. Some people have both problems. The term "heart failure" doesn't mean that your heart has stopped ...

  1. On Possible Arc Inception on Low Voltage Solar Array

    Science.gov (United States)

    Vayner, Boris

    2015-01-01

    Recent analysis of spacecraft failures during the period of 1990-2013 demonstrated clearly that electrostatic discharges caused more than 8 percent of all registered failures and anomalies, and comprised the most costly losses (25 percent) for operating companies and agencies. The electrostatic discharges on spacecraft surfaces are the results of differential charging above some critical (threshold) voltages. The mechanisms of differential charging are well known, and various methods have been developed to prevent a generation of significant electric fields in areas of triple junctions. For example, low bus voltages in Low Earth Orbit plasma environment and slightly conducting layer over cover-glass (ITO) in Geosynchronous Orbit surroundings are believed to be quite reliable measures to prevent discharges on respective surfaces. In most cases, the vulnerable elements of spacecraft (solar arrays, diode boards, etc.) go through comprehensive ground tests in vacuum chambers. However, tests articles contain the miniscule fragments of spacecraft components such as 10-30 solar cells of many thousands deployed on spacecraft in orbit. This is one reason why manufacturing defects may not be revealed in ground tests but expose themselves in arcing on array surface in space. The other reason for ineffectiveness of discharge preventive measures is aging of all materials in harsh orbital environments. The expected life time of modern spacecraft varies within the range of five-fifteen years, and thermal cycling, radiation damages, and mechanical stresses can result in surface erosion on conductive layers and microscopic cracks in cover-glass sheets and adhesive films. These possible damages may cause significant increases in local electric field strengths and subsequent discharges. The primary discharges may or may not be detrimental to spacecraft operation, but they can produce the necessary conditions for sustained arcs initiation. Multiple measures were developed to prevent

  2. Optical diagnostics of a gliding arc

    DEFF Research Database (Denmark)

    Sun, Z.W.; Zhu, J.J.; Li, Z.S.;

    2013-01-01

    Dynamic processes in a gliding arc plasma generated between two diverging electrodes in ambient air driven by 31.25 kHz AC voltage were investigated using spatially and temporally resolved optical techniques. The life cycles of the gliding arc were tracked in fast movies using a high-speed camera...

  3. Modeling and Simulation of Low Voltage Arcs

    NARCIS (Netherlands)

    Ghezzi, L.; Balestrero, A.

    2010-01-01

    Modeling and Simulation of Low Voltage Arcs is an attempt to improve the physical understanding, mathematical modeling and numerical simulation of the electric arcs that are found during current interruptions in low voltage circuit breakers. An empirical description is gained by refined electrical m

  4. Measurement of an Electric Arc Spectra

    OpenAIRE

    Šimek, D.

    2015-01-01

    Article is focused on electric arc spectroscopy diagnostics related to electric low voltage apparatuses. The first attempts of spectroscopy measurements are dealt with. An example of radiation spectra of the electric arc burning between copper electrodes is presented. The problems connected with the measurements are discussed.

  5. Implementing RapidArc into clinical routine

    DEFF Research Database (Denmark)

    Van Esch, Ann; Huyskens, Dominique P; Behrens, Claus F;

    2011-01-01

    With the increased commercial availability of intensity modulated arc therapy (IMAT) comes the need for comprehensive QA programs, covering the different aspects of this newly available technology. This manuscript proposes such a program for the RapidArc (RA) (Varian Medical Systems, Palo Alto...

  6. The structure and singularities of arc complexes

    DEFF Research Database (Denmark)

    Penner, Robert

    A classical combinatorial fact is that the simplicial complex consisting of disjointly embedded chords in a convex planar polygon is a sphere. For any surface F with non-empty boundary, there is an analogous complex Arc(F) consisting of suitable equivalence classes of arcs in F connecting its bou...

  7. Characterization of Micro-arc Oxidized Titanium

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The observation of the sparkling discharges during the micro-arc oxidation process in KOH aqueous electrolyte was achieved. The change of surface morphology was progressively observed and a plausible pore formation mechanism is proposed. Cell proliferation and ALP activity of micro-arc oxidized titanium was evaluated by human body derived osteoblasts and slightly better than those of blasted surface.

  8. The next-generation ARC middleware

    DEFF Research Database (Denmark)

    Appleton, O.; Cameron, D.; Cernak, J.

    2010-01-01

    The Advanced Resource Connector (ARC) is a light-weight, non-intrusive, simple yet powerful Grid middleware capable of connecting highly heterogeneous computing and storage resources. ARC aims at providing general purpose, flexible, collaborative computing environments suitable for a range of use...

  9. Numerical Study on Arc Plasma Behavior During Arc Commutation Process in Direct Current Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    杨飞; 马瑞光; 吴翊; 孙昊; 纽春萍; 荣命哲

    2012-01-01

    This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker (DCCB) contact system. A three-dimensional magneto-hydrodynamic (MHD) model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.

  10. Gliding arc triggered microwave plasma arc at atmospheric pressure for coal gasification application

    Science.gov (United States)

    Jain, Vishal; Visani, A.; Patil, C.; Patel, B. K.; Sharma, P. K.; John, P. I.; Nema, S. K.

    2014-08-01

    Plasma torch is device that efficiently converts electrical energy in to thermal energy for various high temperature applications. The conventional plasma torch comprises of consumable electrodes namely anode and cathode electrodes. The replacement of these electrodes is a complex process owing to its cooling and process shut down requirements. However, microwave plasma arc is electrode-less plasma arc system that is an alternative method to conventional arc technology for generating plasma arc. In this technique, microwave power is efficiently coupled to generate plasma arc by using the property of polar molecule to absorb microwave power. The absorption of microwave power is in form of losses due to intermolecular friction and high collisions between the molecules. This is an efficient method because all microwave power can be absorbed by plasma arc. The main feature of microwave plasma arc is its large uniform high temperature column which is not possible with conventional arc discharge methods. Such type of plasma discharge is very useful in applications where sufficient residence time for treat materials is required. Microwave arc does not require any consumable electrodes and hence, it can be operated continuously that makes it very useful for hazardous effluent treatment applications. Further, microwave cannot ionize neutral particles at atmospheric pressure and hence, a gliding arc is initiated between two thin electrodes in the cavity by applying very low power high voltage (3kV) AC source. In this report, the method for generating microwave arc of 1kW power using commercial microwave oven is elaborated.

  11. Arc burst pattern analysis fault detection system

    Science.gov (United States)

    Russell, B. Don (Inventor); Aucoin, B. Michael (Inventor); Benner, Carl L. (Inventor)

    1997-01-01

    A method and apparatus are provided for detecting an arcing fault on a power line carrying a load current. Parameters indicative of power flow and possible fault events on the line, such as voltage and load current, are monitored and analyzed for an arc burst pattern exhibited by arcing faults in a power system. These arcing faults are detected by identifying bursts of each half-cycle of the fundamental current. Bursts occurring at or near a voltage peak indicate arcing on that phase. Once a faulted phase line is identified, a comparison of the current and voltage reveals whether the fault is located in a downstream direction of power flow toward customers, or upstream toward a generation station. If the fault is located downstream, the line is de-energized, and if located upstream, the line may remain energized to prevent unnecessary power outages.

  12. Medium voltage switch rooms supporting the internal arc test; Cubiculos de media tensao que suportam o ensaio de arco interno

    Energy Technology Data Exchange (ETDEWEB)

    Cintra, Paulo de Brito [Light Servicos de Eletricidade SA, Rio de Janeiro, RJ (Brazil). E-mail: paulocintra@lightrio.com.br; Costa, Eleison S. [Centro de Pesquisas de Energia Eletrica, Rio de Janeiro, RJ (Brazil); Tanakai, Osmar [Siemens Ltda., Sao Paulo, SP (Brazil)

    1999-07-01

    This paper presents the trends and standards for project of construction of shielded switchgear and control gear aiming the switch room capability of supporting an internal arc, and shows the research and development of new solutions resulting from the project and maintenance engineering, aiming the reduction of the failure possibilities and guarantee the personal safety even they occurs.

  13. INTERPOLATION WITH RESTRICTED ARC LENGTH

    Institute of Scientific and Technical Information of China (English)

    Petar Petrov

    2003-01-01

    For given data (ti,yi), I= 0,1,…,n,0 = t0 <t1 <…<tn = 1we study constrained interpolation problem of Favard type inf{‖f"‖∞|f∈W2∞[0,1],f(ti)=yi,i=0,…,n,l(f;[0,1])≤l0}, wherel(f";[0,1])=∫1 0 / 1+f'2(x)dx is the arc length off in [0,1]. We prove the existence of a solution f* of the above problem, that is a quadratic spline with a second derivative f"* , which coincides with one of the constants - ‖f"*‖∞,0,‖f"*‖∞ between every two consecutive knots. Thus, we extend a result ofKarlin concerning Favard problem, to the case of restricted length interpolation.

  14. Computer simulation to arc spraying

    Institute of Scientific and Technical Information of China (English)

    梁志芳; 李午申; 王迎娜

    2004-01-01

    The arc spraying process is divided into two stages: the first stage is atomization-spraying stream (ASS) and the second one is spraying deposition (SD). Then study status is described of both stages' physical model and corresponding controlling-equation. Based on the analysis of study status, the conclusion as follows is got. The heat and mass transfer models with two or three dimensions in ASS stage should be established to far deeply analyses the dynamical and thermal behavior of the overheat droplet. The statistics law of overheated droplets should be further studied by connecting simulation with experiments. More proper validation experiments should be designed for flattening simulation to modify the models in SD stage.

  15. ATLAS DDM integration in ARC

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Cameron, David; Ellert, Mattias;

    The Nordic Data Grid Facility (NDGF) consists of Grid resources running ARC middleware in Scandinavia and other countries. These resources serve many virtual organisations and contribute a large fraction of total worldwide resources for the ATLAS experiment, whose data is distributed and managed...... by the DQ2 software. Managing ATLAS data within NDGF and between NDGF and other Grids used by ATLAS (the LHC Computing Grid and the Open Science Grid) presents a unique challenge for several reasons. Firstly, the entry point for data, the Tier 1 centre, is physically distributed among heterogeneous...... environment. Also, the service used for cataloging the location of data files is different from other Grids but must still be useable by DQ2 and ATLAS users to locate data within NDGF. This paper presents in detail how we solve these issues to allow seamless access worldwide to data within NDGF....

  16. Analysis of arc emission spectra of stainless steel electric arc furnace slag affected by fluctuating arc voltage.

    Science.gov (United States)

    Aula, Matti; Mäkinen, Ari; Fabritius, Timo

    2014-01-01

    Control of chromium oxidation in the electric arc furnace (EAF) is a significant problem in stainless steel production due to variations of the chemical compositions in the EAF charge. One potential method to control chromium oxidation is to analyze the emission spectrum of the electric arc in order to find indicators of rising chromium content in slag. The purpose of this study was to determine if slag composition can be gained by utilizing electric arc emission spectra in the laboratory environment, despite electric arc voltage fluctuations and varying slag composition. The purpose of inducing voltage fluctuation was to simulate changes in the industrial EAF process. The slag samples were obtained from Outokumpu Stainless Oy Tornio Works, and three different arc currents were used. The correlation analysis showed that the emission spectra offer numerous peak ratios with high correlations to the X-ray fluorescence-measured slag CrO(x)/FeO(x) and MnO/SiO2 ratios. These ratios are useful in determining if the reduction agents have been depleted in the EAF. The results suggest that analysis of laboratory-scale electric arc emission spectra is suitable for indicating the high CrO(x) or MnO content of the slag despite the arc fluctuations. Reliable analysis of other slag components was not successful.

  17. Types of Heart Failure

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Types of Heart Failure Updated:Feb 9,2017 Left-sided heart failure ... making. This content was last reviewed April 2015. Heart Failure • Home • About Heart Failure Introduction Types of Heart ...

  18. Towards a theory for Neptune's arc rings

    Science.gov (United States)

    Goldreich, P.; Tremaine, S.; Borderies, N.

    1986-01-01

    It is proposed that the incomplete rings of Neptune consist of a number of short arcs centered on the corotation resonances of a single satellite. The satellite must have a radius of the order of 100 km or more and move on an inclined orbit. Corotation resonances are located at potential maxima. Thus, mechanical energy dissipated by interparticle collisions must be continually replenished to prevent the arcs from spreading. It is shown that each corotation resonance is associated with a nearby Lindblad resonance, which excites the ring particles' orbital eccentricity, thus supplying the energy required to maintain the arc. The ultimate energy reservoir is the satellite's orbital energy. Therefore, interaction with the arcs damps the satellite's orbital inclination. The self-gravity of the arcs limits their contraction and enforces a relation between arc length and mass. The estimated arc masses are so small, of the order of 10 to the 16th g, that the satellite's orbital inclination suffers negligible decay over the age of the solar system. The inferred surface mass densities are comparable to those found in the major rings of Saturn and Uranus.

  19. Contribution For Arc Temperature Affected By Current Increment Ratio At Peak Current In Pulsed Arc

    Science.gov (United States)

    Kano, Ryota; Mitubori, Hironori; Iwao, Toru

    2015-11-01

    Tungsten Inert Gas (TIG) Welding is one of the high quality welding. However, parameters of the pulsed arc welding are many and complicated. if the welding parameters are not appropriate, the welding pool shape becomes wide and shallow.the convection of driving force contributes to the welding pool shape. However, in the case of changing current waveform as the pulse high frequency TIG welding, the arc temperature does not follow the change of the current. Other result of the calculation, in particular, the arc temperature at the reaching time of peak current is based on these considerations. Thus, the accurate measurement of the temperature at the time is required. Therefore, the objective of this research is the elucidation of contribution for arc temperature affected by current increment ratio at peak current in pulsed arc. It should obtain a detail knowledge of the welding model in pulsed arc. The temperature in the case of increment of the peak current from the base current is measured by using spectroscopy. As a result, when the arc current increases from 100 A to 150 A at 120 ms, the transient response of the temperature didn't occur during increasing current. Thus, during the current rise, it has been verified by measuring. Therefore, the contribution for arc temperature affected by current increment ratio at peak current in pulsed arc was elucidated in order to obtain more knowledge of welding model of pulsed arc.

  20. Reconstruction of Late Cretaceous Magmatic Arcs in the Northern Andes: Single Versus Multiple Arc Systems

    Science.gov (United States)

    Cardona, A.; Jaramillo, J. S.; Leon, S.; Hincapie, S.; Mejia, D.; Patino, A. M.; Vanegas, J.; Zapata, S.; Valencia, V.; Jimenez, G.; Monsalve, G.

    2014-12-01

    Although magmatic rocks are major tracers of the geological evolution of convergent margins, pre-collisional events such as subduction erosion, collisional thrusting or late collisional strike slip segmentation may difficult the recognizing of multiple arc systems and therefore the existence of paleogeographic scenarios with multiple subduction systems. New field, U-Pb geochronology and whole rock geochemistry constraints from the northwestern segment of the Central Cordillera in the states of Antioquia and Caldas (Colombia) are used to understand the nature of the Late Cretaceous arc magmatism and evaluate the existence of single or multiple Pacific and Caribbean arc systems in the growth of the Northwestern Andes. The new results integrated with additional field and published information is used to suggest the existence of at least three different magmatic arcs. (1) An Eastern Continental arc built within a well defined Permian to Triassic continental crust that record a protracted 90-70 Ma magmatic evolution, (2) a 90-80 arc formed within attenuated continental crust and associated oceanic crust, (3) 90-88 Ma arc formed over a Late Cretaceous plateau crust. The eastern arcs were formed as part of double eastern vergent subduction system, where the most outboard arc represent a fringing arc formed over detached fragments of continental crust, whereas the easternmost continental arc growth by the closure an subduction of and older and broad Triassic to Early Jurassic back-arc ocean. Its closure also end up in ophiolite emplacement. The third allochtonous oceanic arc was formed over the Caribbean plateau crust and was accreted to the continental margin in the Late Cretaceous. Ongoing paleomagnetic, deformational, gravimetric and basin analysis will be integrate to test this model and understand the complex Late Cretaceous tectonic evolution of the Northern Andes.

  1. Immune mediated liver failure

    OpenAIRE

    Wang, Xiaojing; Ning, Qin

    2014-01-01

    Liver failure is a clinical syndrome of various etiologies, manifesting as jaundice, encephalopathy, coagulopathy and circulatory dysfunction, which result in subsequent multiorgan failure. Clinically, liver failure is classified into four categories: acute, subacute, acute-on-chronic and chronic liver failure. Massive hepatocyte death is considered to be the core event in the development of liver failure, which occurs when the extent of hepatocyte death is beyond the liver regenerative capac...

  2. Understanding contraceptive failure

    OpenAIRE

    Trussell, James

    2009-01-01

    Contraceptive failure is a major source of unintended pregnancy. This chapter will review sources of data and measurement of contraceptive failure, summarize results from the literature on the risks of contraceptive failure during typical and perfect use for available methods of contraception, provide a tool for communicating risks of contraceptive failure to clients, examine determinants of contraceptive failure, and identify methodological pitfalls in the published literature.

  3. Understanding chronic heart failure

    OpenAIRE

    Fenton, Matthew; Burch, Michael

    2007-01-01

    The key principles of chronic heart failure and the development of clinical management strategies are described. The physiological changes in chronic heart failure and the clinical management of children with heart failure are considered, but the treatment of heart failure related to congenital heart disease or the intensive care management of heart failure are not mentioned as both topics require consideration in their own right. A greater understanding of the maladaptive responses to chroni...

  4. The Global Array of Primitve Arc Melts

    Science.gov (United States)

    Schmidt, M. W.; Jagoutz, O. E.

    2015-12-01

    A longstanding question concerns the nature of the melts forming in the subarc mantle and giving rise to arc magmatism. The global array of primitive arc melts (1180 volcanic rocks in 25 arcs extracted from the georoc database, calculated to be in equilibrium with mantle olivine) yields five principal melt types: calc-alkaline basalts and high-Mg andesites, tholeiitic basalts and high-Mg andesites, and shoshonitic or alkaline arc melts; many arcs have more than one type. Primitive calc-alkaline basalts occur in 11 arcs but most strikingly, 8 continental arcs (incl. Aleutians, Cascades, Japan, Mexico, Kamtschatka) have a continuous range of calc-alkaline basalts to high-Mg andesites with mostly 48-58 wt% SiO2. In each arc, these are spatially congruent, trace element patterns overlap, and major elements form a continuum. Their Ca-Mg-Si systematics suggests saturation in olivine+opx+cpx. We hence interpret the large majority of high-Mg andesites as derived from primitive calc-alkaline basalts through fractionation and reaction in the shallower mantle. Removal of anhydrous mantle phases at lower pressures increases SiO2 and H2O-contents while Mg# and Ni remain buffered to mantle values. Primitive tholeiitic basalts (Cascades, Kermadec, Marianas, Izu-Bonin, Japan, Palau, Sunda) have a much lesser subduction signal (e.g. in LILE) than the calc-alkaline suite. These tholeiites have been interpreted to form through decompression melting, but also characterize young intraoceanic arcs. In the two continental arcs with both tholeiitic and calc-alkaline primitive basalts (clearly distinct in trace patterns), there is no clear spatial segregation (Casacades, Japan). Three intraoceanic arcs (Marianas, Izu-Bonin, Tonga) have primitive tholeiitic, highly depleted high-Mg andesites (boninites) with HFSE and HREE slightly above primitive mantle values. These deviate in majors from the array formed by the basalts and calc-alkaline andesites suggesting that only these formed from a

  5. Formation of the G-ring arc

    Science.gov (United States)

    Araujo, N. C. S.; Vieira Neto, E.; Foryta, D. W.

    2016-09-01

    Since 2004, the images obtained by the Cassini spacecraft's on-board cameras have revealed the existence of several small satellites in the Saturn system. Some of these small satellites are embedded in arcs of particles. While these satellites and their arcs are known to be in corotation resonances with Mimas, their origin remains unknown. This work investigates one possible process for capturing bodies into a corotation resonance, which involves increasing the eccentricity of a perturbing body. Therefore, through numerical simulations and analytical studies, we show a scenario in which the excitation of Mimas's eccentricity could capture particles in a corotation resonance. This is a possible explanation for the origin of the arcs.

  6. Formation of the G-ring arc

    CERN Document Server

    Araujo, N C S; Foryta, D W

    2016-01-01

    Since 2004, the images obtained by Cassini spacecraft's on-board cameras have revealed the existence of several small satellites in the Saturn system. Some of these small satellites are embedded in arcs of particles. While these satellites and their arcs are known to be in corotation resonances with Mimas, their origin remains unknown. This work investigates one possible process for capturing bodies into a corotation resonance, which involves raising the eccentricity of a perturbing body. Therefore, through numerical simulations and analytical studies, we show a scenario that the excitation of Mimas' eccentricity could capture particles in a corotation resonance and given a possible explanation for the origin for the arcs.

  7. Cathodic Vacuum Arc Plasma of Thallium

    OpenAIRE

    Yushkov, Georgy Yu.; Anders, Andre

    2006-01-01

    Thallium arc plasma was investigated in a vacuum arc ion source. As expected from previous consideration of cathode materials in the Periodic Table of the Elements, thallium plasma shows lead-like behavior. Its mean ion charge state exceeds 2.0 immediately after arc triggering, reaches the predicted 1.60 and 1.45 after about 100 microsec and 150 microsec, respectively. The most likely ion velocity is initially 8000 m/s and decays to 6500 m/s and 6200 m/s after 100 microsec and 150 micros...

  8. FE MODELING & ANALYSIS OF ARC WELDED T-JOINT

    Directory of Open Access Journals (Sweden)

    S.N.Pilare

    2012-06-01

    Full Text Available Arc welded structures are widely used in automobiles, constructions & power plants. As the main cause of weldment failure is design defect & overload, hence it is necessary to analyze the maximum stresses inthe weldment. In this paper an experimentation is carried out on welded T-joint to determine the breaking stress in the weldment. The FE analysis & analytical estimation of breaking stress is also carried out to verify the experimental results. The stress distribution along weld size & throat thickness is evaluated and also compared with reported findings. Further T-joint weld is analyzed under static tensile & bending load by varying the gap between parent plates with and without chamfer at weldment edges. The fatigue analysis under alternating tensile and bending load is also carried out and fatigue life of weldment is predicted with variation in the gap between parent plates.

  9. Linear volcanic segments in the Sunda Arc, Indonesia: Implications for arc lithosphere control upon volcano distribution

    Science.gov (United States)

    Macpherson, C. G.; Pacey, A.; McCaffrey, K. J.

    2012-12-01

    The overall curvature of many subduction zones is immediately apparent and the term island arc betrays the common assumption that subduction zone magmatism occurs in curved zones. This assumption can be expressed by approximating island arcs as segments of small circles on the surface of a sphere. Such treatments predict that the location of arc volcanoes is related to their vertical separation from the slab (in fact, the depth to seismicity in the slab) and require that the primary control on the locus of magmatism lies either within the subducted slab or the mantle wedge that separates the subducted and overriding lithospheric plates. The concept of curved arcs ignores longstanding observations that magmatism in many subduction systems occurs as segments of linearly arranged volcanic centres. Further evidence for this distribution comes from the close relationship between magmatism and large scale, arc-parallel fabrics in some arcs. Similarly, exposures of deep arc crust or mantle often reveal elongation of magmatic intrusions sub-parallel to the inferred trend of the arc. The Sunda Arc forms the Indonesian islands from Sumatra to Alor and provides an important test for models of volcano distribution for several reasons. First, Sunda has hosted abundant historic volcanic activity. Second, with the notable exception of Krakatau, every volcano in the arc is subaerial from base to cone and, therefore, can be readily identified where there is a suitable extent of local mapping that can be used to ground-truth satellite imagery. Third, there are significant changes in the stress regime along the length of the arc, allowing the influence of the upper plate to be evaluated by comparison of different arc segments. Finally, much of the Sunda Arc has proved difficult to accommodate in models that try to relate volcano distribution to the depth to the subducted slab. We apply an objective line-fitting protocol; the Hough Transform, to explore the distribution of volcanoes

  10. Prostate treatments, 1MRT o RapidArc; Tratamiento de prostata, IMART o RapidArc?

    Energy Technology Data Exchange (ETDEWEB)

    Castro novais, J.; Ruiz Maqueda, S.; Pardo Perez, E.; Molina Lopez, M. Y.; Cerro Penalver, E.

    2015-07-01

    Techniques that modulate the dose (as IMRT or RapidArcTM) improve dose homogeneity within the target volume decreasing the dose in healthy organs. The aim of this work is to study the dosimetric differences in prostate radiotherapy treatments with IMRT and RapidArcTM. The results of the 109 patients studied show that plans to RapidArcTM have better coverage, compliance and dose gradient outside the target volume. (Author)

  11. Seward, Alaska 3 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 3 arc-second Seward Alaska Elevation Grid provides bathymetric data in ASCII raster format of 2.67-second resolution in geographic coordinates. This grid is...

  12. Observation of gliding arc surface treatment

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Zhu, Jiajian; Ehn, A.

    2015-01-01

    . Water contact angle measurements indicate that the treatment uniformity improves significantly when the AC gliding arc is tilted to the polymer surface. Thickness reduction of the gas boundary layer, explaining the improvement of surface treatment, by the ultrasonic irradiation was directly observed......An alternating current (AC) gliding arc can be conveniently operated at atmospheric pressure and efficiently elongated into the ambient air by an air flow and thus is useful for surface modification. A high speed camera was used to capture dynamics of the AC gliding arc in the presence of polymer...... surfaces. A gap was observed between the polymer surface and the luminous region of the plasma column, indicating the existence of a gas boundary layer. The thickness of the gas boundary layer is smaller at higher gas flow-rates or with ultrasonic irradiation to the AC gliding arc and the polymer surface...

  13. Laboratory arc furnace features interchangeable hearths

    Science.gov (United States)

    Armstrong, J. L.; Kruger, O. L.

    1967-01-01

    Laboratory arc furnace using rapidly interchangeable hearths gains considerable versatility in casting so that buttons or special shaped castings can be produced. It features a sight glass for observation.

  14. Arc tracks on nanostructured surfaces after microbreakdowns

    Science.gov (United States)

    Sinelnikov, D.; Bulgadaryan, D.; Hwangbo, D.; Kajita, S.; Kolodko, D.; Kurnaev, V.; Ohno, N.

    2016-09-01

    Studying of initial steps of unipolar arc ignition process is important for reduction of probability of arcing between the plasma and the wall in thermonuclear devices. Tungsten nano-fuzz surface formed by helium plasma irradiation at high fluences and temperatures is a perfect material for arc ignition. Snowflake-like craters were detected on the fuzzy surfaces after short micro-breakdowns. Such sort of craters have not been observed before on any other metallic surfaces. These specific traces are formed due to unique properties of the fuzz structure. The nano-fuzz could be easily melted and vaporized by micro-breakdown current, due to its porosity and bad thermal conductivity, and formation of low conducting metallic vapour under the cathode spot causes discharge movement to the nearest place. Thus, even low current arc can easily move and leave traces, which could be easily observed by a secondary electron microscope.

  15. Seward, Alaska 1 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1 arc-second Seward Alaska Elevation Grid provides bathymetric data in ASCII raster format of .89-second resolution in geographic coordinates. This grid is...

  16. Effect of arc on radiation thermometry in welding process

    Institute of Scientific and Technical Information of China (English)

    李亮玉; 王燕; 武宝林

    2002-01-01

    The effect of arc on radiation thermometry is analyzed in a field close to the arc during the welding process, and the ratio of signal to noise and other factors are obtained for a small current arc .The method of the temperature measurement is feasible when the arc current is decreased to a smaller value in the welding process.

  17. Resistance Characteristics of Arc in Long Air Gap

    Institute of Scientific and Technical Information of China (English)

    YU Zhanqing; YU Junjie; ZENG Rong; CHEN He; PENG Xiang

    2013-01-01

    Arc resistance is an important parameter for characterizing long arcs in air,and its laboratory testing is of importance for accurate arc modeling of electromagnetic transient caused by short circuit fault.Therefore,we constructed an experimental system to study the characteristics of long AC arc in air.Driven by currents of 10 kA or 40 kA (root mean square value),the system produces arcs with different initial lengths of 1 m,2 m and 4 m,and the movement of the arcs are captured by a high-speed camera.After performing experiments using the system,we carried out analysis and comparisons of the arc resistance of arcs with different lengths and different currents,as well as a study of the relationship between the macro-morphology and the resistance of the arcs.Conclusions were drawn from the experimental results:the arc voltage had obvious saturation characteristics; the arc resistance increased with the increase of arc length and the decrease of current; the arcs bended or extended significantly in time and the peak arc voltage within a single cycle increased correspondingly; the arcs had voltage and current in the same phase.In the end,a formula of arc resistance based on the experiment results is derived.

  18. Palaeomagnetic constraints on the geodynamic evolution of the Gibraltar Arc

    NARCIS (Netherlands)

    Krijgsman, W.; Garces, M.

    2004-01-01

    Subduction zone roll-back was recently put forward as a convincing model to explain the geometry and evolution of the Gibraltar Arc. For other subduction-related arc systems of the Mediterranean, such as the Calabrian Arc and the Hellenic Arc, palaeomagnetic rotation data from Neogene extensional ba

  19. 49 CFR 195.226 - Welding: Arc burns.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Arc burns. 195.226 Section 195.226 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.226 Welding: Arc burns. (a) Each arc burn must be repaired. (b) An arc burn...

  20. Basins in ARC-continental collisions

    Science.gov (United States)

    Draut, Amy E.; Clift, Peter D.; Busby, Cathy; Azor, Antonio

    2012-01-01

    Arc-continent collisions occur commonly in the plate-tectonic cycle and result in rapidly formed and rapidly collapsing orogens, often spanning just 5-15 My. Growth of continental masses through arc-continent collision is widely thought to be a major process governing the structural and geochemical evolution of the continental crust over geologic time. Collisions of intra-oceanic arcs with passive continental margins (a situation in which the arc, on the upper plate, faces the continent) involve a substantially different geometry than collisions of intra-oceanic arcs with active continental margins (a situation requiring more than one convergence zone and in which the arc, on the lower plate, backs into the continent), with variable preservation potential for basins in each case. Substantial differences also occur between trench and forearc evolution in tectonically erosive versus tectonically accreting margins, both before and after collision. We examine the evolution of trenches, trench-slope basins, forearc basins, intra-arc basins, and backarc basins during arc-continent collision. The preservation potential of trench-slope basins is low; in collision they are rapidly uplifted and eroded, and at erosive margins they are progressively destroyed by subduction erosion. Post-collisional preservation of trench sediment and trench-slope basins is biased toward margins that were tectonically accreting for a substantial length of time before collision. Forearc basins in erosive margins are usually floored by strong lithosphere and may survive collision with a passive margin, sometimes continuing sedimentation throughout collision and orogeny. The low flexural rigidity of intra-arc basins makes them deep and, if preserved, potentially long records of arc and collisional tectonism. Backarc basins, in contrast, are typically subducted and their sediment either lost or preserved only as fragments in melange sequences. A substantial proportion of the sediment derived from

  1. Influence of metal vapour on arc temperatures in gas-metal arc welding: convection versus radiation

    Science.gov (United States)

    Murphy, Anthony B.

    2013-06-01

    The presence of metal vapour in gas-metal arc welding has been shown to have two strong effects on the arc plasma: a decrease in temperature throughout the arc, and the formation of a local temperature minimum near the arc axis. These effects have been attributed, on the basis of different computational models, to either the increased radiative emission associated with the presence of metal vapour in the arc plasma, or the influence of the metal vapour influx on convective flow in the arc. This question is investigated using a three-dimensional computational model in which the production and the transport of metal vapour are taken into account self-consistently. Parameters relevant to welding of thin sheets of aluminum are examined. For these conditions, it is found that the first effect (the decrease in temperature throughout the arc) is due to both the increased radiative emission and the influence of the metal vapour influx on flow. The second effect (the local temperature minimum, which in this case occurs just below the wire electrode) is a consequence of the influence of aluminum vapour produced from the wire electrode on flow in the arc. By examining published results and the energy balance in the plasma, it is shown that for welding of steel with higher arc currents, the increased radiative emission can lead to a local temperature minimum at a greater distance from the wire electrode.

  2. Arcing flow phenomena; Visualisation des ecoulements en presence d'un arc de coupure

    Energy Technology Data Exchange (ETDEWEB)

    Rachard, H.; Mottet, C. [Schneider Electric, Centre de Recherches A2, 75 - Paris (France)

    2002-06-01

    Optical diagnostic techniques have been used for studying electric arcing phenomena at Schneider Electric for many years now, and are integrated in new-product development practice. Studies have so far focused on electric arc behaviour, but today we are especially interested in studying the interaction of an electric arc with its immediate environment, i.e. gaseous medium and neighbouring materials. This article starts by discussing the specificities of electric arcs in low-voltage circuit-breakers, then goes on to examine diagnostic methods for viewing the physical phenomena of interest. After setting out and analysing the results obtained, we conclude with details on planned upgrades targeting enhanced diagnostic performance. (author)

  3. Rapid magmatic processes accompany arc-continent collision: the Western Bismarck arc, Papua New Guinea

    Science.gov (United States)

    Cunningham, Heather; Gill, Jim; Turner, Simon; Caulfield, John; Edwards, Louise; Day, Simon

    2012-11-01

    New U-Th-Ra, major and trace element, and Sr-Nd-Pb isotope data are presented for young lavas from the New Britain and Western Bismarck arcs in Papua New Guinea. New Britain is an oceanic arc, whereas the latter is the site of an arc-continent collision. Building on a recent study of the Manus Basin, contrasts between the two arcs are used to evaluate the processes and timescales of magma generation accompanying arc-continent collision and possible slab detachment. All three suites share many attributes characteristic of arc lavas that can be ascribed to the addition of a regionally uniform subduction component derived from the subducting altered oceanic crust and sediment followed by dynamic melting of the modified mantle. However, the Western Bismarck arc lavas diverge from the Pb isotope mixing array formed by the New Britain and the Manus Basin lavas toward elevated 208Pb/204Pb. We interpret this to reflect a second and subsequent addition of sediment melt at crustal depth during collision. 238U and 226Ra excesses are preserved in all of the lavas and are greatest in the Western Bismarck arc. High-Mg andesites with high Sr/Y ratios in the westernmost arc are attributed to recent shallow mantle flux melting at the slab edge. Data for two historical rhyolites are also presented. Although these rhyolites formed in quite different tectonic settings and display different geochemical and isotopic compositions, both formed from mafic parents within millennia.

  4. Sensitivity of collapsed arc QA method for delivery errors in Volumetric Modulated Arc Therapy (VMAT)

    Science.gov (United States)

    Young, Tony; Xing, Aitang; Vial, Philp; Thwaites, David; Holloway, Lois; Arumugam, Sankar

    2015-01-01

    In this paper the sensitivity of an Electronic Portal Imaging Device (EPID) to detecting introduced Volumetric Arc Therapy (VMAT) treatment errors was studied using the Collapsed Arc method. Two clinical Head and Neck (H&N) and Prostate treatment plans had gantry dependent dose and MLC errors introduced to the plans. These plans were then delivered to an Elekta Synergy Linear Accelerator EPID and compared to the original treatment planning system Collapsed Arc dose matrix. With the Collapsed Arc technique the EPID was able to detect MLC errors down to 2mm and dose errors of down to 3% depending on the treatment plan complexity and gamma tolerance used.

  5. Study on Ceramic Cutting by Plasma Arc

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Engineering ceramics are typical difficult-to-machine materials because of high hardness and brittleness. PAC (Plasma Arc Cutting) is a very important thermal cutting process and has been successfully used in cutting stainless steel and other difficult-to-machine alloys. PAC's application in cutting ceramics, however, is still limited because the most ceramics are not good electronic conducts, and transferred plasma arc cannot be produced between cathode and work-piece. So we presented a method of plasma ...

  6. Electric arc furnace models for flicker study

    Directory of Open Access Journals (Sweden)

    Catalina González Castaño

    2016-06-01

    Full Text Available Objective: The aim of this paper is to evaluate voltage fluctuations or flicker of two electric arc furnace models through comparison with real data.Method: The first proposed model is founded on the energy conservation principle, which generates a non-linear differential equation modelling the electric arc voltage – current characteristics. Voltage fluctuations are generated using a chaotic circuit that modulates the amplitude of arc voltage. The second model is based on the empirical relationship between the arc diameter or length as well as voltage and electrical current on the arc. Voltage fluctuations are considered adding a random signal in the arc length. Both models are implemented in PSCADTM.Results: The results of both models are compared with real data taken at the most critical stage of the operation of the furnace, and they show that the model based on energy conservation has a lower average mean square error in the voltages and currents 5.6 V and 1.7 kA against 27,2 V y 3.38 kA obtained with the second model.Conclusions: Both models consider the nonlinearity and random behavior present in this type of load, validating their inclusion in computer models of electric power systems.

  7. Magnesium isotope geochemistry in arc volcanism

    Science.gov (United States)

    Teng, Fang-Zhen; Hu, Yan; Chauvel, Catherine

    2016-06-01

    Incorporation of subducted slab in arc volcanism plays an important role in producing the geochemical and isotopic variations in arc lavas. The mechanism and process by which the slab materials are incorporated, however, are still uncertain. Here, we report, to our knowledge, the first set of Mg isotopic data for a suite of arc lava samples from Martinique Island in the Lesser Antilles arc, which displays one of the most extreme geochemical and isotopic ranges, although the origin of this variability is still highly debated. We find the δ26Mg of the Martinique Island lavas varies from -0.25 to -0.10, in contrast to the narrow range that characterizes the mantle (-0.25 ± 0.04, 2 SD). These high δ26Mg values suggest the incorporation of isotopically heavy Mg from the subducted slab. The large contrast in MgO content between peridotite, basalt, and sediment makes direct mixing between sediment and peridotite, or assimilation by arc crust sediment, unlikely to be the main mechanism to modify Mg isotopes. Instead, the heavy Mg isotopic signature of the Martinique arc lavas requires that the overall composition of the mantle wedge is buffered and modified by the preferential addition of heavy Mg isotopes from fluids released from the altered subducted slab during fluid-mantle interaction. This, in turn, suggests transfer of a large amount of fluid-mobile elements from the subducting slab to the mantle wedge and makes Mg isotopes an excellent tracer of deep fluid migration.

  8. Magnesium isotope geochemistry in arc volcanism.

    Science.gov (United States)

    Teng, Fang-Zhen; Hu, Yan; Chauvel, Catherine

    2016-06-28

    Incorporation of subducted slab in arc volcanism plays an important role in producing the geochemical and isotopic variations in arc lavas. The mechanism and process by which the slab materials are incorporated, however, are still uncertain. Here, we report, to our knowledge, the first set of Mg isotopic data for a suite of arc lava samples from Martinique Island in the Lesser Antilles arc, which displays one of the most extreme geochemical and isotopic ranges, although the origin of this variability is still highly debated. We find the δ(26)Mg of the Martinique Island lavas varies from -0.25 to -0.10, in contrast to the narrow range that characterizes the mantle (-0.25 ± 0.04, 2 SD). These high δ(26)Mg values suggest the incorporation of isotopically heavy Mg from the subducted slab. The large contrast in MgO content between peridotite, basalt, and sediment makes direct mixing between sediment and peridotite, or assimilation by arc crust sediment, unlikely to be the main mechanism to modify Mg isotopes. Instead, the heavy Mg isotopic signature of the Martinique arc lavas requires that the overall composition of the mantle wedge is buffered and modified by the preferential addition of heavy Mg isotopes from fluids released from the altered subducted slab during fluid-mantle interaction. This, in turn, suggests transfer of a large amount of fluid-mobile elements from the subducting slab to the mantle wedge and makes Mg isotopes an excellent tracer of deep fluid migration.

  9. Recent ARC developments: Through modularity to interoperability

    Energy Technology Data Exchange (ETDEWEB)

    Smirnova, O; Cameron, D; Ellert, M; Groenager, M; Johansson, D; Kleist, J [NDGF, Kastruplundsgade 22, DK-2770 Kastrup (Denmark); Dobe, P; Joenemo, J; Konya, B [Lund University, Experimental High Energy Physics, Institute of Physics, Box 118, SE-22100 Lund (Sweden); Fraagaat, T; Konstantinov, A; Nilsen, J K; Saada, F Ould; Qiang, W; Read, A [University of Oslo, Department of Physics, P. O. Box 1048, Blindern, N-0316 Oslo (Norway); Kocan, M [Pavol Jozef Safarik University, Faculty of Science, Jesenna 5, SK-04000 Kosice (Slovakia); Marton, I; Nagy, Zs [NIIF/HUNGARNET, Victor Hugo 18-22, H-1132 Budapest (Hungary); Moeller, S [University of Luebeck, Inst. Of Neuro- and Bioinformatics, Ratzeburger Allee 160, D-23538 Luebeck (Germany); Mohn, B, E-mail: oxana.smirnova@hep.lu.s [Uppsala University, Department of Physics and Astronomy, Div. of Nuclear and Particle Physics, Box 535, SE-75121 Uppsala (Sweden)

    2010-04-01

    The Advanced Resource Connector (ARC) middleware introduced by NorduGrid is one of the basic Grid solutions used by scientists worldwide. While being well-proven in daily use by a wide variety of scientific applications at large-scale infrastructures like the Nordic DataGrid Facility (NDGF) and smaller scale projects, production ARC of today is still largely based on conventional Grid technologies and custom interfaces introduced a decade ago. In order to guarantee sustainability, true cross-system portability and standards-compliance based interoperability, the ARC community undertakes a massive effort of implementing modular Web Service (WS) approach into the middleware. With support from the EU KnowARC project, new components were introduced and the existing key ARC services got extended with WS technology based standard-compliant interfaces following a service-oriented architecture. Such components include the hosting environment framework, the resource-coupled execution service, the re-engineered client library, the self-healing storage solution and the peer-to-peer information system, to name a few. Gradual introduction of these new services and client tools into the production middleware releases is carried out together with NDGF and thus ensures a smooth transition to the next generation Grid middleware. Standard interfaces and modularity of the new component design are essential for ARC contributions to the planned Universal Middleware Distribution of the European Grid Initiative.

  10. New method for capturing arc of moving on switching apparatus

    Institute of Scientific and Technical Information of China (English)

    LIU Jiao-min; WANG Jing-hong

    2007-01-01

    The switching arc that occurs in contact gap when contact of low voltage apparatus closes or breaks in electric circuit is harmful to the contacts, insulation, and reliability of electrical gear because of its very high temperature. As arcing time is very short in switching gear, it is very difficult to observe arc phenomena directly for researchers. Therefore, visualization of switching arc is important for understanding arc phenomena, to analyze the arc features, and to improve the design and reliability of switching gear. Based on analyzing the visualization methods proposed by researchers, a new switching arc capturing approach is introduced in this paper. Arc image acquisition, and image processing techniques were studied. A switching arc image acquisition and visual simulation software based on high speed CCD camera hard ware system was designed and implemented to yield enhanced arc image with good visual effect.

  11. Making and breaking an Island arc: a new perspective from the Oligocene Kyushu-Palau arc

    Science.gov (United States)

    Ishizuka, O.; Taylor, R. N.; Yuasa, M.; Ohara, Y.

    2010-12-01

    The Kyushu-Palau Ridge (KPR) is a 2000km long remnant island arc that is separated from the active Izu-Bonin-Mariana (IBM) arc system by a series of spreading and rift basins. In this study we present 40Ar/39Ar ages and geochemical data for new samples taken from the entire length of the Kyushu-Palau arc. As such, this data provides the first comprehensive evaluation of temporal and spatial changes that are present in an Eocene-Oligocene island arc. Kyushu-Palau arc geochemistry is evaluated alongside new data from the conjugate arc which is stranded within the IBM fore-arc. Boninitic magmatism gave way to transitional arc suites including high-Mg andesites at c. 45 Ma (Ishizuka et al., 2006). After the transitional 45-41 Ma period, a mature arc system developed through the Eocene-Oligocene time: This volcanism is now preserved as the KPR. Dating results from 33 sites indicate that the KPR was active between 25 and 43 Ma, but the majority of the exposed volcanism occurred in the final phase of this arc, between 25 and 27 Ma. Unlike the IBM, the KPR has only limited systematic along-arc trends and does not include any of the strongly HIMU lavas found to the south of Izu-Bonin. Two components found along the KPR are found to have geochemistry that suggests an origin in the supra-subduction mantle rather than from the descending ocean crust. Firstly, in the south of the arc, EM-2-like lavas are present where the West Philippine Basin was in the final stages of spreading. Secondly, EM-1-like lavas are present in a restricted section of the arc, suggesting a localised heterogeneity. Subduction flux beneath the KPR generally imparted a Pb isotope vector towards low Δ8/4 (19). This is a similar trend to the Eocene/Oligocene lavas found on the eastern side of the basins which split the arc at 25Ma. Another geochemical heterogeneity is found at the KPR-Daito Ridge intersection where arc magmatism occurred on pre-existing Daito Ridge crust: a Cretaceous remnant arc

  12. [Understanding heart failure].

    Science.gov (United States)

    Boo, José Fernando Guadalajara

    2006-01-01

    Heart failure is a disease with several definitions. The term "heart failure" is used by has brougth about confusion in the terminology. For this reason, the value of the ejection fraction (< 0.40 or < 0.35) is used in most meganalyses on the treatment of heart failure, avoiding the term "heart failure" that is a confounding concept. In this paper we carefully analyze the meaning of contractility, ventricular function or performance, preload, afterload, heart failure, compensation mechanisms in heart failure, myocardial oxygen consumption, inadequate, adequate and inappropriate hypertrophy, systole, diastole, compliance, problems of relaxation, and diastolic dysfunction. Their definitions are supported by the original scientific descriptions in an attempt to clarify the concepts about ventricular function and heart failure and, in this way, use the same scientific language about the meaning of ventricular function, heart failure, and diastolic dysfunction.

  13. Real System Failures

    Data.gov (United States)

    National Aeronautics and Space Administration — This resource area contains descriptions of actual electronic systems failure scenarios with an emphasis on the diversity of failure modes and effects that can...

  14. Contraceptive failure in China.

    Science.gov (United States)

    Wang, Duolao

    2002-09-01

    This study examines patterns and differentials of contraceptive failure rates by method and characteristics of users, using the Chinese Two-per-Thousand Fertility Survey data. The results show that contraceptive failure rates for modern methods including sterilization are some of the highest in the world. The first year failure rates are 4.2% for male sterilization, 0.7% for female sterilization, 10.3% for IUD, 14.5% for pill, and 19.0% for condom. There are also some differentials in contraceptive failure rates by users' sociodemographic and fertility characteristics. Contraceptive failure rate declines with women's age for all reversible methods. Rural women have higher sterilization, IUD, and condom contraceptive failure rates than urban women. Women with two or more children have a higher failure rate for sterilization methods but have lower failure rates for other methods.

  15. Direct probing of anode arc root dynamics and voltage instability in a dc non-transferred arc plasma jet

    Science.gov (United States)

    Ghorui, S.; Tiwari, N.; Meher, K. C.; Jan, A.; Bhat, A.; Sahasrabudhe, S. N.

    2015-12-01

    The transient dynamics of the anode arc root in a dc non-transferred arc plasma torch is captured through fast photography and directly correlated with the associated voltage instability for the first time. The coexistence of multiple arc roots, the transition to a single arc root, root formation and extinction are investigated for the steady, takeover and re-strike modes of the arc. Contrary to the usual concept, the emerging plasma jet of a dc non-transferred arc plasma torch is found to carry current. An unusually long self-propelled arc plasma jet, a consequence of the phenomenon, is demonstrated.

  16. Very fast LHC Crab cavity failures and their mitigation

    CERN Document Server

    Baer, T; De Maria, R; Fartoukh, S D; Jensen, E; Tomas, R; Tuckmantel, J; Wenninger, J; Yee Rendon, B; Zimmermann, F

    2012-01-01

    For the high-luminosity LHC upgrade program (HL-LHC), the installation of crab cavities (CCs) is needed to compensate the geometric luminosity loss due to the crossing angle and for luminosity leveling [1]. The baseline is a local scheme with CCs around the ATLAS and CMS experiments. In a failure case (e.g. a control failure or arcing in the coupler), the voltage and/or phase of a CC can change significantly with a very fast time constant of the order of 1 to 10 LHC turns. This can lead to large, global betatron oscillations of the beam. The impact of CC failures on the beam dynamics is discussed and the results of dedicated simulations are presented. Mitigation strategies to limit the impact of CC failures to an acceptable level are proposed.

  17. Acute liver failure

    DEFF Research Database (Denmark)

    Larsen, Fin Stolze; Bjerring, Peter Nissen

    2011-01-01

    Acute liver failure (ALF) results in a multitude of serious complications that often lead to multi-organ failure. This brief review focuses on the pathophysiological processes in ALF and how to manage these.......Acute liver failure (ALF) results in a multitude of serious complications that often lead to multi-organ failure. This brief review focuses on the pathophysiological processes in ALF and how to manage these....

  18. In Support of Failure

    Science.gov (United States)

    Carr, Allison

    2013-01-01

    In this essay, I propose a concerted effort to begin devising a theory and pedagogy of failure. I review the discourse of failure in Western culture as well as in composition pedagogy, ultimately suggesting that failure is not simply a judgement or indication of rank but is a relational, affect-bearing concept with tremendous relevance to…

  19. Effect of acoustic field parameters on arc acoustic binding during ultrasonic wave-assisted arc welding.

    Science.gov (United States)

    Xie, Weifeng; Fan, Chenglei; Yang, Chunli; Lin, Sanbao

    2016-03-01

    As a newly developed arc welding method, power ultrasound has been successfully introduced into arc and weld pool during ultrasonic wave-assisted arc welding process. The advanced process for molten metals can be realized by utilizing additional ultrasonic field. Under the action of the acoustic wave, the plasma arc as weld heat source is regulated and its characteristics make an obvious change. Compared with the conventional arc, the ultrasonic wave-assisted arc plasma is bound significantly and becomes brighter. To reveal the dependence of the acoustic binding force on acoustic field parameters, a two-dimensional acoustic field model for ultrasonic wave-assisted arc welding device is established. The influences of the radiator height, the central pore radius, the radiator radius, and curvature radius or depth of concave radiator surface are discussed using the boundary element method. Then the authors analyze the resonant mode by this relationship curve between acoustic radiation power and radiator height. Furthermore, the best acoustic binding ability is obtained by optimizing the geometric parameters of acoustic radiator. In addition, three concave radiator surfaces including spherical cap surface, paraboloid of revolution, and rotating single curved surface are investigated systematically. Finally, both the calculation and experiment suggest that, to obtain the best acoustic binding ability, the ultrasonic wave-assisted arc welding setup should be operated under the first resonant mode using a radiator with a spherical cap surface, a small central pore, a large section radius and an appropriate curvature radius.

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  1. GUI for studying the parameters influence of the electric arc model for a three-phase electric arc furnace

    Science.gov (United States)

    Ghiormez, L.; Prostean, O.; Panoiu, M.; Panoiu, C.

    2017-01-01

    This paper presents an analysis regarding the modeling of the behavior for a three-phase electric arc furnace installation. Therefore, a block diagram is implemented in Simulink that represents the modeling of the entire electric arc furnace installation. This block diagram contains also the modeling of the electric arc which is the element that makes the electric arc furnace behaving as a nonlinear load. The values for the model parameters of the electric arc furnace installation are like the ones from the real installation taken into consideration. Other model parameters are the electric arc model ones. In order to study the influence of the parameters of the electric arc models, it is developed a Matlab program that contains the graphical user interfaces. These interfaces make connection with the models of the electric arc implemented in Simulink. The interfaces allow the user to modify parameters for each of the electric arc model. Current and voltage of the electric arc are the variables taken into account to study the influence of the parameters on the electric arc models. Waveforms for voltage and current of the electric arc are illustrated when a parameter of the model is modified in order to analyze the importance of this parameter on the electric arc model. Also, for each of the models is presented the voltage-current characteristic of the electric arc because this characteristic gives information about the behavior of the electric arc furnace installation.

  2. Bone Marrow Failure Secondary to Cytokinesis Failure

    Science.gov (United States)

    2015-12-01

    have assessed the role of FA pathway in mitosis and confirmed that murine FA-deficient hematopoietic stem cells exhibit p53- mediated growth defects...results suggest that bone marrow failure in FA may be caused, in part, by p53- mediated cellular defects and underscore the importance of... mediated apoptosis of HSCs due to cytokinesis failure. The major goal of the project was to assess whether the p53- mediated apoptosis due to

  3. Method to reduce arc blow during DC arc welding of pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Espina-Hernandez, J. H.; Rueda-Morales, G.L.; Caleyo, F.; Hallen, J. M. [Instituto Politecnico Nacional, Mexico, (Mexico); Lopez-Montenegro, A.; Perz-Baruch, E. [Pemex Exploracion y Produccion, Tabasco, (Mexico)

    2010-07-01

    Steel pipelines are huge ferromagnetic structures and can be easily subjected to arc blow during the DC arc welding process. The development of methods to avoid arc blow during pipeline DC arc welding is a major objective in the pipeline industry. This study developed a simple procedure to compensate the residual magnetic field in the groove during DC arc welding. A Gaussmeter was used to perform magnetic flux density measurements in pipelines in southern Mexico. These data were used to perform magnetic finite element simulations using FEMM. Different variables were studied such as the residual magnetic field in the groove or the position of the coil with respect to the groove. An empirical predictive equation was developed from these trials to compensate for the residual magnetic field. A new method of compensating for the residual magnetic field in the groove by selecting the number of coil turns and the position of the coil with respect to the groove was established.

  4. Overview of ArcGIS Engine Controls%ArcGIS Engine控件综述

    Institute of Scientific and Technical Information of China (English)

    刘磊

    2010-01-01

    ArcGIS Engine是ESRI公司发布的嵌入式地理信息系统软件开发包.基于ArcGIS Engine开发的应用程序一般有3类:独立非可视化应用程序、独立可视化应用程序和嵌入式应用程序,由于ArcGIS Engine提供了一套可复用、跨平台、设计良好的ArcGIS控件,因此利用控件开发可视化的GIS应用程序是一种常用的开发方式.重点探讨了ArcGIS Engine自带控件的功能、使用方法以及与伙伴控件之间的联系机制.

  5. Research of Arc Chamber Optimization Techniques Based on Flow Field and Arc Joint Simulation

    Science.gov (United States)

    Zhong, Jianying; Guo, Yujing; Zhang, Hao

    2016-03-01

    The preliminary design of an arc chamber in the 550 kV SF6 circuit breaker was proposed in accordance with the technical requirements and design experience. The structural optimization was carried out according to the no-load flow field simulation results and verified by no-load pressure measurement. Based on load simulation results such as temperature field variation at the arc area and the tendency of post arc current under different recovery voltage, the second optimal design was completed and its correctness was certificated by a breaking test. Results demonstrate that the interrupting capacity of an arc chamber can be evaluated by the comparison of the gas medium recovery speed and post arc current growth rate.

  6. Critical crack path assessments in failure investigations

    Directory of Open Access Journals (Sweden)

    Robert D. Caligiuri

    2015-10-01

    Full Text Available This paper presents a case study in which identification of the controlling crack path was critical to identifying the root cause of the failure. The case involves the rupture of a 30-inch (0.76 m natural gas pipeline in 2010 that tragically led to the destruction of a number of homes and the loss of life. The segment of the pipeline that ruptured was installed in 1956. The longitudinal seam of the segment that ruptured was supposed to have been fabricated by double submerged arc welding. Unfortunately, portions of the segment only received a single submerged arc weld on the outside, leaving unwelded areas on the inside diameter. Post-failure examination of the segment revealed that the rupture originated at one of these unwelded areas. Examination also revealed three additional crack paths or zones emanating from the unwelded area: a zone of ductile tearing, a zone of fatigue, and a zone of cleavage fracture, in that sequence. Initial investigators ignored the ductile tear, assumed the critical crack path was the fatigue component, and (incorrectly concluded that the root cause of the incident was the failure of the operator to hydrotest the segment after it was installed in 1956. However, as discussed in this paper, the critical path or mechanism was the ductile tear. Furthermore, it was determined that the ductile tear was created during the hydrotest at installation by a mechanism known as pressure reversal. Thus the correct root cause of the rupture was the hydrotest the operator subjected the segment to at installation, helping to increase the awareness of operators and regulators about the potential problems associated with hydrotesting.

  7. Critical Length Criterion and the Arc Chain Model for Calculating the Arcing Time of the Secondary Arc Related to AC Transmission Lines

    Science.gov (United States)

    Cong, Haoxi; Li, Qingmin; Xing, Jinyuan; Li, Jinsong; Chen, Qiang

    2015-06-01

    The prompt extinction of the secondary arc is critical to the single-phase reclosing of AC transmission lines, including half-wavelength power transmission lines. In this paper, a low-voltage physical experimental platform was established and the motion process of the secondary arc was recorded by a high-speed camera. It was found that the arcing time of the secondary arc rendered a close relationship with its arc length. Through the input and output power energy analysis of the secondary arc, a new critical length criterion for the arcing time was proposed. The arc chain model was then adopted to calculate the arcing time with both the traditional and the proposed critical length criteria, and the simulation results were compared with the experimental data. The study showed that the arcing time calculated from the new critical length criterion gave more accurate results, which can provide a reliable criterion in term of arcing time for modeling and simulation of the secondary arc related with power transmission lines. supported by National Natural Science Foundation of China (Nos. 51277061 and 51420105011)

  8. Gas Arcs in Comet Hyakutake: Revisited

    Science.gov (United States)

    Combi, M. R.; Harris, W. M.; Kabin, K.

    2000-10-01

    The recent break-up of the nucleus of Comet LINEAR S4 demonstrates that fragmentation is an important cometary process and that it is not a rare phenomenon. Comet Hyakutake (1996 B2) underwent an outburst of gas production on March 21, 1996. Subsequent to the outburst, fragments, or condensations as they have been called, were observed moving tailward from the position of the nucleus. Arc-shaped structures were seen in images of gas species (OH, CN and C2) providing clear evidence of production of gas from cometary nucleus debris also tailward of the nucleus. We have already (Harris et al. 1997, Science 277, 676) described observations taken with the WIYN telescope consisting of a 6-hour time sequence of images on March 26, 1996 of CN and dust continuum and a single OH image showing that the arc, and by inference it's source, was generally moving tailward with the visible condensations. The entire OH arc was reproduced using a kinetic Direct Simulation Monte Carlo (DSMC) calculation for water and all its photodissociation products. DSMC is suited to this physical environment that is in transition from fluid conditions in the inner coma to free-expansion in the outer coma. Our model asuming a string of fragments within the apex of the arc (i.e., the intersection of the arc and the tailward sun-comet line) reproduced the arc. Here we present a more extensive parameter study of the arc using DSMC and a solution of the standard perfect-fluid Euler equations. We find that a secondary source just behind the apex of the arc can reproduce the OH arc, but the location of the source must be much closer to the apex than indicated by solutions of the Navier-Stokes equations (NSE) (Rodionov et al. 1998, Icarus 136, 232). We find that we must use unrealistically large collision cross sections to reproduce the NSE results, and that the NSE results are not substantially different from a simpler Euler equation approach. This work has been supported by NASA Planetary Atmospheres

  9. The geochemistry and petrogenesis of the Paleoproterozoic Green Mountain arc: A composite(?), bimodal, oceanic, fringing arc

    Science.gov (United States)

    Jones, D.S.; Barnes, C.G.; Premo, W.R.; Snoke, A.W.

    2011-01-01

    The inferred subduction affinity of the ~1780-Ma Green Mountain arc, a dominantly bimodal igneous terrane (together with immature marine and volcaniclastic sedimentary rocks) accreted to the southern margin of the Wyoming province, is integral to arc-accretion models of the Paleoproterozoic growth of southern Laurentia. Conversely, the dominantly bimodal nature of many putative arc-related igneous suites throughout southern Laurentia, including the Green Mountain arc, has also been used to support models of growth by extension of pre-existing crust. We report new geochemical and isotopic data from ~1780-Ma gabbroic and granodioritic to tonalitic rocks of the Big Creek Gneiss, interpreted as consanguineous with previously studied metavolcanic rocks of the Green Mountain Formation.The ~1780-Ma Big Creek Gneiss mafic rocks show clear geochemical signatures of a subduction origin and provide no supporting evidence for extensional tectonism. The ~1780-Ma Big Creek Gneiss felsic rocks are attributed to partial melting of mafic and/or mixed lower-crustal material. The bimodal nature of the suite results from the combination of arc basalts and felsic crustal melts. The lack of andesite is consistent with the observed tholeiitic differentiation trend of the mafic magmas. The lower e{open}Nd(1780Ma) values for the felsic rocks vs. the mafic rocks suggest that the unexposed lower crust of the arc may be older than the arc and that Trans-Hudson- or Penokean-aged rocks possibly form the substratum of the arc. Our results reinforce previous interpretations that arc-related magmatism played a key role in the Paleoproterozoic crustal growth of southern Laurentia, but also support the possibility of unexposed older crust as basement to the arcs. ?? 2011 Elsevier B.V.

  10. BASIC THEORY AND METHOD OF WELDING ARC SPECTRAL INFORMATION

    Institute of Scientific and Technical Information of China (English)

    Li Junyue; Li Zhiyong; Li Huan; Xue Haitao

    2004-01-01

    Arc spectral information is a rising information source which can solve many problems that can not be done with arc electric information and other arc information.It is of important significance to develop automatic control technique of welding process.The basic theory and methods on it play an important role in expounding and applying arc spectral information.Using concerned equation in plasma physics and spectrum theory,a system of equations including 12 equations which serve as basic theory of arc spectral information is set up.Through analyzing of the 12 equations,a basic view that arc spectral information is the reflection of arc state and state variation,and is the most abundant information resource reflecting welding arc process is drawn.Furthermore,based on the basic theory,the basic methods of test and control of arc spectral information and points out some applications of it are discussesed.

  11. Arc Conductance and Flow Velocity Affected by Transient Recovery Voltage

    Science.gov (United States)

    Fukuoka, Reo; Ishikawa, Yuya; Ono, Seisui; Sato, Ken; Yamamoto, Shinji; Iwao, Toru

    2016-09-01

    Recently, the stable supply of electric power is indispensable. The GCB (Gas Circuit Breaker) can prevent the spread of the fault current. However, it should have the reliability more. Therefore the GCB has been researched for performance improvement of the arc interruption of abnormal fault current without the fail. Therefore, it is important to prevent the breakdown such as the re-ignition and thermal re-ignition of arc after the arc interruption. It is necessary to reduce the arc conductance in order to prevent the re-ignition of arc. The arc conductance is derived from the temperature distribution and the volume of the arc. The temperature distribution of the arc is formed by convection. In this research, the arc conductance and flow velocity affected by transient recovery voltage are elucidated. The flow rate and temperature distribution of the arc is calculated with changing transient recovery voltage. In addition, the arc conductance is calculated in order to know the extinguish arc ability. As a result, when the transient recovery voltage increases, the probability of re-ignition increases. Therefore, the arc temperature and the arc conductance were increased.

  12. Evaluation of volumetric modulated arc therapy for cranial radiosurgery using multiple noncoplanar arcs

    Energy Technology Data Exchange (ETDEWEB)

    Audet, Chantal; Poffenbarger, Brett A.; Chang, Pauling; Jackson, Paul S.; Lundahl, Robert E.; Ryu, Stephen I.; Ray, Gordon R. [Radiation Oncology Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States); Neurosurgery Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States); Radiation Oncology Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States); Neurosurgery Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States); Radiation Oncology Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States)

    2011-11-15

    Purpose: To evaluate a commercial volumetric modulated arc therapy (VMAT), using multiple noncoplanar arcs, for linac-based cranial radiosurgery, as well as evaluate the combined accuracy of the VMAT dose calculations and delivery. Methods: Twelve patients with cranial lesions of variable size (0.1-29 cc) and two multiple metastases patients were planned (Eclipse RapidArc AAA algorithm, v8.6.15) using VMAT (1-6 noncoplanar arcs), dynamic conformal arc (DCA, {approx}4 arcs), and IMRT (nine static fields). All plans were evaluated according to a conformity index (CI), healthy brain tissue doses and volumes, and the dose to organs at risk. A 2D dose distribution was measured (Varian Novalis Tx, HD120 MLC, 1000 MU/min, 6 MV beam) for the {approx}4 arc VMAT treatment plans using calibrated film dosimetry. Results: The CI (0-1 best) average for all plans was best for {approx}4 noncoplanar arc VMAT at 0.86 compared with {approx}0.78 for IMRT and a single arc VMAT and 0.68 for DCA. The volumes of healthy brain receiving 50% of the prescribed target coverage dose or more (V{sub 50%}) were lowest for the four arc VMAT [RA(4)] and DCA plans. The average ratio of the V{sub 50%} for the other plans to the RA(4) V{sub 50%} were 1.9 for a single noncoplanar arc VMAT [RA(1nc)], 1.4 for single full coplanar arc VMAT [RA(1f)] and 1.3 for IMRT. The V{sub 50%} improved significantly for single isocenter multiple metastases plan when two noncoplanar VMAT arcs were added to a full single coplanar one. The maximum dose to 5 cc of the outer 1 cm rim of healthy brain which one may want to keep below nonconsequential doses of 300-400 cGy, was 2-3 times greater for IMRT, RA(1nc) and RA(1f) plans compared with the multiple noncoplanar arc DCA and RA(4) techniques. Organs at risk near (0-4 mm) to targets were best spared by (i) single noncoplanar arcs when the targets are lateral to the organ at risk and (ii) by skewed nonvertical planes of IMRT fields when the targets are not lateral to the

  13. Managing Feelings about Heart Failure

    Science.gov (United States)

    ... About Heart Failure Module 6: Managing Feelings About Heart Failure Download Module Order Hardcopy Heart failure can cause ... professional help for emotional problems. Common Feelings About Heart Failure It is common for people to feel depressed ...

  14. Arc-welding robot. 2; Yosetsu robot

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, S. [Yaskawa Electric Corp., Kitakyushu (Japan)

    1995-02-01

    This is an introductory lecture on the selection and handling of arc-welding robot and was explained easily in Q and A style. This is the second of its series and extraction examples of Q and A are Q: type of stations for setting works, A: fixed, slide, inversion, rotary types and their combination, Q: station type for constructing a highly universal system for a wide variety of works, A: a highly universal robot was realized owing to external shaft control function. Recently, one robot can control a maximum of 21 shafts to cope with a variety of works, Q: off-line teaching for arc-welding robot, A: yes. It is available but does not spread as much as for spot since arc welding requires a high tracing accuracy. 12 figs.

  15. Circular arc snakes and kinematic surface generation

    KAUST Repository

    Barton, Michael

    2013-05-01

    We discuss the theory, discretization, and numerics of curves which are evolving such that part of their shape, or at least their curvature as a function of arc length, remains unchanged. The discretization of a curve as a smooth sequence of circular arcs is well suited for such purposes, and allows us to reduce evolution of curves to the evolution of a control point collection in a certain finite-dimensional shape space. We approach this evolution by a 2-step process: linearized evolution via optimized velocity fields, followed by optimization in order to exactly fulfill all geometric side conditions. We give applications to freeform architecture, including "rationalization" of a surface by congruent arcs, form finding and, most interestingly, non-static architecture. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  16. ArcForm - A multimodal notation

    DEFF Research Database (Denmark)

    Allsopp, Benjamin Brink

    ArcForm (AF) is a visual notation based on a new graph-like network structure. It supports a unique approach to labeling arcs and nodes to allow diverse and grammatically normal English (or other natural language) sentences to be embedded in the network (Allsopp, 2013). In doing this AF combines ...... as a notational foundation for e-learning platforms (Allsopp 2015). We will explore a prototype supporting basic interaction with the landscape and consider how it can benefit from virtual reality, online social curating and the block chain....... of individual nodes and arcs will allow us to create new perspectives on the underlying information. This presentation will use multiple visual examples to show how AF achieves its many affordances. We will discuss how it has been used in education research (Misfeldt 2016) and how it could be used...

  17. Magnesium isotope geochemistry in arc volcanism

    Science.gov (United States)

    Teng, Fang-Zhen; Hu, Yan

    2016-01-01

    Incorporation of subducted slab in arc volcanism plays an important role in producing the geochemical and isotopic variations in arc lavas. The mechanism and process by which the slab materials are incorporated, however, are still uncertain. Here, we report, to our knowledge, the first set of Mg isotopic data for a suite of arc lava samples from Martinique Island in the Lesser Antilles arc, which displays one of the most extreme geochemical and isotopic ranges, although the origin of this variability is still highly debated. We find the δ26Mg of the Martinique Island lavas varies from −0.25 to −0.10, in contrast to the narrow range that characterizes the mantle (−0.25 ± 0.04, 2 SD). These high δ26Mg values suggest the incorporation of isotopically heavy Mg from the subducted slab. The large contrast in MgO content between peridotite, basalt, and sediment makes direct mixing between sediment and peridotite, or assimilation by arc crust sediment, unlikely to be the main mechanism to modify Mg isotopes. Instead, the heavy Mg isotopic signature of the Martinique arc lavas requires that the overall composition of the mantle wedge is buffered and modified by the preferential addition of heavy Mg isotopes from fluids released from the altered subducted slab during fluid−mantle interaction. This, in turn, suggests transfer of a large amount of fluid-mobile elements from the subducting slab to the mantle wedge and makes Mg isotopes an excellent tracer of deep fluid migration. PMID:27303032

  18. On the Trail of Joan of Arc

    Directory of Open Access Journals (Sweden)

    Linda Joyce Forristal

    2013-12-01

    Full Text Available The year 2012 marked the 600th anniversary of the birthday of Joan of Arc (Fr., Jeanne d’Arc (1412–1431. Tributes to this national heroine can be found all over France. There are literally countless statues, streets and restaurants named after her and many sites dedicated to her life. However, despite widespread social and mechanical reproduction and cultural naming in relation to the Maid of Orléans, there is no official network or integrated signage in France to promote cultural heritage tourism to the numerous Joan of Arc sites and festivals, even though her life and death, by any measure, were seminal events in the country’s history. Unfortunately, the pilgrim who wants to follow or intersect with Joan of Arc’s trail through France, for cultural, historical or religious reasons, must do so without much help. Using Actor Network Theory and Site Sacralization Theory as framing devices, this paper explores human actors and tangible and intangible non-human factors that may have contributed to the lack of a unified tourism product despite the existence of an adequate Joan of Arc tourismscape. Insights gleaned from this research include Joan’s conflicted status as both/either saint and/or patriot, the existence of no cooperation or linkage between Joan of Arc sites, and cautious French tourism development policies. Several possible scenarios are suggested as suitable means to help implement or foster the creation of an on-the-ground or virtual Joan of Arc trail or tour.

  19. Plasma distribution of cathodic ARC deposition system

    Energy Technology Data Exchange (ETDEWEB)

    Anders, S.; Raoux, S.; Krishnan, K.; MacGill, R.A.; Brown, I.G. [Lawrence Berkeley National Lab., CA (United States)

    1996-08-01

    The plasma distribution using a cathodic arc plasma source with and without magnetic macroparticle filter has been determined by depositing on a transparent plastic substrate and measuring the film absorption. It was found that the width of the distribution depends on the arc current, and it also depends on the cathode material which leads to a spatial separation of the elements when an alloy cathode is used. By applying a magnetic multicusp field near the exit of the magnetic filter, it was possible to modify the plasma distribution and obtain a flat plasma profile with a constant and homogeneous elemental distribution.

  20. Ion source based on the cathodic arc

    Science.gov (United States)

    Sanders, David M.; Falabella, Steven

    1994-01-01

    A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles.

  1. Architectural Surfaces and Structures from Circular Arcs

    KAUST Repository

    Shi, Ling

    2013-12-01

    In recent decades, the popularity of freeform shapes in contemporary architecture poses new challenges to digital design. One of them is the process of rationalization, i.e. to make freeform skins or structures affordable to manufacture, which draws the most attention from geometry researchers. In this thesis, we aim to realize this process with simple geometric primitives, circular arcs. We investigate architectural surfaces and structures consisting of circular arcs. Our focus is lying on how to employ them nicely and repetitively in architectural design, in order to decrease the cost in manufacturing. Firstly, we study Darboux cyclides, which are algebraic surfaces of order ≤ 4. We provide a computational tool to identify all families of circles on a given cyclide based on the spherical model of M ̈obius geometry. Practical ways to design cyclide patches that pass through certain inputs are presented. In particular, certain triples of circle families on Darboux cyclides may be suitably arranged as 3-webs. We provide a complete classification of all possible 3-webs of circles on Darboux cyclides. We then investigate the circular arc snakes, which are smooth sequences of circu- lar arcs. We evolve the snakes such that their curvature, as a function of arc length, remains unchanged. The evolution of snakes is utilized to approximate given surfaces by circular arcs or to generated freeform shapes, and it is realized by a 2-step pro- cess. More interestingly, certain 6-arc snake with boundary constraints can produce a smooth self motion, which can be employed to build flexible structures. Another challenging topic is approximating smooth freeform skins with simple panels. We contribute to this problem area by approximating a negatively-curved 5 surface with a smooth union of rational bilinear patches. We provide a proof for vertex consistency of hyperbolic nets using the CAGD approach of the rational B ́ezier form. Moreover, we use Darboux transformations for the

  2. Evaporation Erosion During the Relay Contact Breaking Process Based on a Simplified Arc Model

    Institute of Scientific and Technical Information of China (English)

    CUI Xinglei; ZHOU Xue; ZHAI Guofu; PENG Xiyuan

    2016-01-01

    Evaporation erosion of the contacts is one of the fundamental failure mechanisms for relays.In this paper,the evaporation erosion characteristics are investigated for the copper contact pair breaking a resistive direct current (dc) 30 V/10 A circuit in the air.Molten pool simulation of thc contacts is coupled with the gas dynamics to cMculate the evaporation rate.A simplified arc model is constructed to obtain the contact voltage and current variations with time for the prediction of the current density and the heat flux distributions flowing from the arc into the contacts.The evaporation rate and mass variations with time during the breaking process are presented.Experiments are carried out to verify the simulation results.

  3. Arcing Model of a Disconnector and its Effect on VFTO

    Science.gov (United States)

    Lin, Xin; Wang, Na; Xu, Jianyuan

    2013-07-01

    In the computational process of very fast transient over-voltage (VFTO), it is essential to find an accurate model for a gas insulated substation. The arcing model of the disconnector is particularly important. The general arcing model is not able to give a good description of the arc development process. In this paper, based on the physical process of arcing and existing arc models (the exponential time-varying resistance model and the segmental arcing models), a dynamic arcing model is proposed, which is divided into two stages before and after the zero crossing. The dynamic arcing model combines hyperbola time-varying resistance and the Mayr model to describe the dynamic process of arcing. The present paper creates an arc model blockset upon the Matlab/Simulink software platform. Moreover for a specific 1100 kV station, VFTO is simulated in detail based on different arcing models. It is demonstrated that the dynamic arcing model can describe the physical arc process precisely and is useful for improving the accuracy of VFTO simulations.

  4. Failure Analysis Handbook

    Science.gov (United States)

    1989-08-18

    47) described a method they called the "failure-experience matrix." This matrix was a three-dimensional array of cells , with failure modes along one...Russo, DFat ý , compiled by McDonnell-Dcuglas Astrovautics Cmpany, Huntington Beach, California, published by Metals and Ceramics Information Center...matrix." This matrix was a three dimensional array of cells , with failure modes along one axis, ryont "mechardcal function along a second axis and

  5. Failure to thrive.

    Science.gov (United States)

    Krugman, Scott D; Dubowitz, Howard

    2003-09-01

    Failure to thrive is a condition commonly seen by primary care physicians. Prompt diagnosis and intervention are important for preventing malnutrition and developmental sequelae. Medical and social factors often contribute to failure to thrive. Either extreme of parental attention (neglect or hypervigilance) can lead to failure to thrive. About 25 percent of normal infants will shift to a lower growth percentile in the first two years of life and then follow that percentile; this should not be diagnosed as failure to thrive. Infants with Down syndrome, intrauterine growth retardation, or premature birth follow different growth patterns than normal infants. Many infants with failure to thrive are not identified unless careful attention is paid to plotting growth parameters at routine checkups. A thorough history is the best guide to establishing the etiology of the failure to thrive and directing further evaluation and management. All children with failure to thrive need additional calories for catch-up growth (typically 150 percent of the caloric requirement for their expected, not actual, weight). Few need laboratory evaluation. Hospitalization is rarely required and is indicated only for severe failure to thrive and for those whose safety is a concern. A multidisciplinary approach is recommended when failure to thrive persists despite intervention or when it is severe.

  6. PNW River Reach Files -- 1:100k Watercourses (arcs)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This feature class includes the ARC features from the 2001 version of the PNW River Reach files Arc/INFO coverage. Separate, companion feature classes are also...

  7. Modeling Vacuum Arcs On Spacecraft Solar Panel Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft charging and subsequent vacuum arcing poses a significant threat to satellites in LEO and GEO plasma conditions. Localized arc discharges can cause a...

  8. On the use of accelerators dosimetric ally equivalent to the technique RapidArc VMAT; Sobre el uso de aceleradores dosimetricamente equivalentes con la tecnica RadidArc VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Serna Berna, A.; Mata Colodro, F.; Puchades Puchades, V.; Ramos Amores, D.

    2013-07-01

    Scheduled maintenance and unexpected failures can cause a stop in the operation of accelerators for hours or days. Prolonging treatments cause discomfort, anxiety and decreased chance for cure. Using a second accelerator backup set of the same design and dosimetry, would mitigate the effects of such interruptions. The aim of this study is to determine the safety of using either two accelerators in Rapid Arc VMAT treatments. (Author)

  9. Soundness of Timed-Arc Workflow Nets

    DEFF Research Database (Denmark)

    Mateo, Jose Antonio; Srba, Jiri; Sørensen, Mathias Grund

    2014-01-01

    Analysis of workflow processes with quantitative aspects like timing is of interest in numerous time-critical applications. We suggest a workflow model based on timed-arc Petri nets and study the foundational problems of soundness and strong (time-bounded) soundness. We explore the decidability o...

  10. ArcAid Interactive Archery Assistant

    Directory of Open Access Journals (Sweden)

    Jeroen Vervaeke

    2015-12-01

    Full Text Available This paper describes the design process of a bow aiming system, called ArcAid, which is an interactive archery assistant. The main goal of ArcAid is to introduce a way for beginner Robin Hoods to learn the art of archery to its fullest. In order to achieve this goal, our smartphone-based design focuses on a fun and interactive learning process that gives constant feedback to the user on how to hit a certain goal. A SPIKE high- end laser sensor is used for the distance measurement and the smartphone’s accelerometer is used to define the angle of inclination. To measure the force on the arrow and the displacement of the string, a flex sensor is attached upon one of the arcs of the bow. All sensor data is processed in an Arduino Nano microprocessor and feedback to the user is given by a dedicated smartphone app. In this paper, we mainly focus on the construction, mechanics and electronics of the ArcAid bow and on the design of the mobile app, which is the game controller. Furthermore, we briefly discuss some future development ideas.

  11. Remote electrical arc suppression by laser filamentation

    CERN Document Server

    Schubert, Elise; Kasparian, Jérôme; Wolf, Jean-Pierre

    2015-01-01

    We investigate the interaction of narrow plasma channels formed in the filamentation of ultrashort laser pulses, with a DC high voltage. The laser filaments prevent electrical arcs by triggering corona that neutralize the high-voltage electrodes. This phenomenon, due to the electric field modulation and free electron release around the filament, opens new prospects to lightning and over-voltage mitigation.

  12. Hypergravity effects on glide arc plasma

    NARCIS (Netherlands)

    Šperka, J.; Souček, P.; van Loon, J.J.W.A.; Dowson, A.; Schwarz, C.; Krause, J.; Kroesen, G.; Kudrle, V.

    2013-01-01

    The behaviour of a special type of electric discharge - the gliding arc plasma - has been investigated in hypergravity (1g-18g) using the Large Diameter Centrifuge (LDC) at ESA/ESTEC. The discharge voltage and current together with the videosignal from a fast camera have been recorded during the exp

  13. Arc discharge sliding over a conducting surface

    NARCIS (Netherlands)

    Goor, van F.A.; Mitko, S.V.; Ochkin, V.N.; Paramonov, A.P.; Witteman, W.J.

    1997-01-01

    Results of experimental and theoretical studies of the arc discharge which slides over the surface of a conductor are reported. Experiments were performed in air and argon ambients at various pressures. It is found that the velocity of the discharge plasma front depends linearly on the strength of t

  14. Stability of alternating current gliding arcs

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Salewski, Mirko; Leipold, Frank;

    2014-01-01

    that the critical length can be increased by increasing the AC frequency, decreasing the serial resistance and lowering the gas flow rate. The predicted dependence of gas flow rate on the arc length is experimentally demonstrated. The gap width is varied to study an optimal electrode design, since the extended non...

  15. First NIF ARC target shot results

    Science.gov (United States)

    Chen, Hui; di Nicola, P.; Hermann, M.; Kalantar, D.; Martinez, D.; Tommasini, R.; NIF ARC Team

    2015-11-01

    The commissioning of the Advanced Radiographic Capability (ARC) laser system in the National Ignition Facility (NIF) is currently in progress. ARC laser is designed to ultimately provide eight beamlets with pulse duration adjustable from 1 to 50 ps, and energies up to 1.7 kJ per beamlet. ARC will add critical capability for the NIF facility for creating precision x-ray backlighters needed for many current NIF ICF and HED experiments. ARC can also produce MeV electrons and protons for new science experiment on NIF. In the initial set of experiments, 4 of the 8 beamlets are being commissioned up to 1 kJ per beam at 30 ps pulse length using foil and wire targets. X-ray energy distribution, spot size and pulse duration are measured using various diagnostics. This talk will describe the shot setup and results. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  16. Gas tungsten arc welder with electrode grinder

    Science.gov (United States)

    Christiansen, David W.; Brown, William F.

    1984-01-01

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  17. Roadmap for the ARC Grid Middleware

    DEFF Research Database (Denmark)

    Kleist, Josva; Eerola, Paula; Ekelöf, Tord

    2006-01-01

    The Advanced Resource Connector (ARC) or the NorduGrid middleware is an open source software solution enabling production quality computational and data Grids, with special emphasis on scalability, stability, reliability and performance. Since its first release in May 2002, the middleware is depl...

  18. Nonlinear Study of Industrial Arc Spring Dampers

    DEFF Research Database (Denmark)

    Lahriri, Said; Santos, Ilmar; Hartmann, Henning

    2011-01-01

    The objective of this paper is to present a numerical approach for analyzing parameter excited vibrations on a gas compressor, induced by the nonlinear characteristic of the arc spring feature of certain designs of squeeze film dampers, SFDs. The behavior of the journal is studied in preparation ...

  19. Supersonic Vortex Gerdien Arc with Magnetic Thermal Insulation

    Science.gov (United States)

    Winterberg, F.

    1988-02-01

    Temperatures up to ~ 5 x 104 oK have been obtained with water vortex Gerdien arcs, and temperatures of ~ 105oK have been reached in hydrogen plasma arcs with magnetic thermal insulation through an externally applied strong magnetic field. It is suggested that a further increase in arc temperatures up to 106oK can conceivably be attained by a combination of both techniques, using a Gerdien arc with a supersonic hydrogen gas vortex.

  20. H2O and CO2 in magmas from the Mariana arc and back arc systems

    Science.gov (United States)

    Newman, Sally; Stolper, Edward; Stern, Robert

    2000-05-01

    We examined the H2O and CO2 contents of glasses from lavas and xenoliths from the Mariana arc system, an intraoceanic convergent margin in the western Pacific, which contains an active volcanic arc, an actively spreading back arc basin, and active behind-the-arc cross-chain volcanoes. Samples include (1) glass rims from Mariana arc, Mariana trough, and cross-chain submarine lavas; (2) glass inclusions in arc and trough phenocrysts; and (3) glass inclusions from a gabbro + anorthosite xenolith from Agrigan (Mariana arc). Glass rims of submarine arc lavas contain 0.3-1.9 wt % H2O, and CO2 is below detection limits. Where they could be compared, glass inclusions in arc phenocrysts contain more H2O than their host glasses; most arc glasses and phenocryst inclusions contain no detectable CO2, with the exception of those from a North Hiyoshi shoshonite, which contains 400-600 ppm. The glass inclusions from the Agrigan xenolith contain 4-6% H2O, and CO2 is below the detection limit. Glasses from the cross-chain lavas are similar to those from the arc: H2O contents are 1.4-1.7 wt %, and CO2 is below detection limits. Volatile contents in Mariana trough lava glass rims are variable: 0.2-2.8 wt % H2O and 0-300 ppm CO2. Glass inclusions from trough phenocrysts have water contents similar to the host glass, but they can contain up to 875 ppm CO2. Volatile contents of melt inclusions from trough and arc lavas and from the xenolith imply minimum depths of crystallization of ~1-8 km. H2O and CO2 contents of Mariana trough glasses are negatively correlated, indicating saturation of the erupting magma with a CO2-H2O vapor at the pressure of eruption (~400 bars for these samples), with the vapor ranging from nearly pure CO2 at the CO2-rich end of the glass array to nearly pure H2O at the H2O-rich end. Degassing of these magmas on ascent and eruption leads to significant loss of CO2 (thereby masking preeruptive CO2 contents) but minimal disturbance of preeruptive H2O contents. For

  1. The arc arises: The links between volcanic output, arc evolution and melt composition

    Science.gov (United States)

    Brandl, Philipp A.; Hamada, Morihisa; Arculus, Richard J.; Johnson, Kyle; Marsaglia, Kathleen M.; Savov, Ivan P.; Ishizuka, Osamu; Li, He

    2017-03-01

    Subduction initiation is a key process for global plate tectonics. Individual lithologies developed during subduction initiation and arc inception have been identified in the trench wall of the Izu-Bonin-Mariana (IBM) island arc but a continuous record of this process has not previously been described. Here, we present results from International Ocean Discovery Program Expedition 351 that drilled a single site west of the Kyushu-Palau Ridge (KPR), a chain of extinct stratovolcanoes that represents the proto-IBM island arc, active for ∼25 Ma following subduction initiation. Site U1438 recovered 150 m of oceanic igneous basement and ∼1450 m of overlying sediments. The lower 1300 m of these sediments comprise volcaniclastic gravity-flow deposits shed from the evolving KPR arc front. We separated fresh magmatic minerals from Site U1438 sediments, and analyzed 304 glass (formerly melt) inclusions, hosted by clinopyroxene and plagioclase. Compositions of glass inclusions preserve a temporal magmatic record of the juvenile island arc, complementary to the predominant mid-Miocene to recent activity determined from tephra layers recovered by drilling in the IBM forearc. The glass inclusions record the progressive transition of melt compositions dominated by an early 'calc-alkalic', high-Mg andesitic stage to a younger tholeiitic stage over a time period of 11 Ma. High-precision trace element analytical data record a simultaneously increasing influence of a deep subduction component (e.g., increase in Th vs. Nb, light rare earth element enrichment) and a more fertile mantle source (reflected in increased high field strength element abundances). This compositional change is accompanied by increased deposition rates of volcaniclastic sediments reflecting magmatic output and maturity of the arc. We conclude the 'calc-alkalic' stage of arc evolution may endure as long as mantle wedge sources are not mostly advected away from the zones of arc magma generation, or the rate of

  2. Electric-arc synthesis of soot with high content of higher fullerenes in parallel arc

    Science.gov (United States)

    Dutlov, A. E.; Nekrasov, V. M.; Sergeev, A. G.; Bubnov, V. P.; Kareev, I. E.

    2016-12-01

    Soot with a relatively high content of higher fullerenes (C76, C78, C80, C82, C84, C86, etc.) is synthesized in a parallel arc upon evaporation of pure carbon electrodes. The content of higher fullerenes in soot extract amounts to 13.8 wt % when two electrodes are simultaneously burnt in electric-arc reactor. Such a content is comparable with the content obtained upon evaporation of composite graphite electrodes with potassium carbonate impurity.

  3. Bulk arc strain, crustal thickening, magma emplacement, and mass balances in the Mesozoic Sierra Nevada arc

    Science.gov (United States)

    Cao, Wenrong; Paterson, Scott; Saleeby, Jason; Zalunardo, Sean

    2016-03-01

    Quantifying crustal deformation is important for evaluating mass balance, material transfer, and the interplay between tectonism and magmatism in continental arcs. We present a dataset of >650 finite strain analyses compiled from published works and our own studies with associated structural, geochronologic, and geobarometric information in central and southern Sierra Nevada, California, to quantify the arc crust deformation. Our results show that Mesozoic tectonism results in 65% arc-perpendicular bulk crust shortening under a more or less plane strain condition. Mesozoic arc magmatism replaced ∼80% of this actively deforming arc crust with plutons requiring significantly greater crustal thickening. We suggest that by ∼85 Ma, the arc crust thickness was ∼80 km with a 30-km-thick arc root, resulting in a ∼5 km elevation. Most tectonic shortening and magma emplacement must be accommodated by downward displacements of crustal materials into growing crustal roots at the estimated downward transfer rate of 2-13 km/Myr. The downward transfer of crustal materials must occur in active magma channels, or in "escape channels" in between solidified plutons that decrease in size with time and depth resulting in an increase in the intensity of constrictional strain with depth. We argue that both tectonism and magmatism control the thickness of the crust and surface elevation with slight modification by surface erosion. The downward transported crustal materials initially fertilize the MASH zone thus enhancing to the generation of additional magmas. As the crustal root grows it may potentially pinch out and cool the mantle wedge and thus cause reduction of arc magmatism.

  4. Evaluation of the clinical usefulness of modulated Arc treatment

    CERN Document Server

    Lee, Young Kyu; Kim, Yeon Sil; Choi, Byung Ock; Nam, Sang Hee; Park, Hyeong Wook; Kim, Shin Wook; Shin, Hun Joo; Lee, Jae Choon; Kim, Ji Na; Park, Sung Kwang; Kim, Jin Young; Kang, Young-Nam

    2015-01-01

    The purpose of this study is to evaluate the clinical usefulness of modulated arc (mARC) treatment techniques. The mARC treatment plans of the non-small cell lung cancer (NSCLC) patients were performed in order to verify the clinical usefulness of mARC. A pre study was conducted to find the most competent plan condition of mARC treatment and the usefulness of mARC treatment plan was evaluated by comparing it with the other Arc treatment plans such as Tomotherapy and RapidArc. In the case of mARC, the optimal condition for the mARC plan was determined by comparing the dosimetric performance of the mARC plans with the use of various parameters. The various parameters includes the photon energies (6 MV, 10 MV), optimization point angle (6{\\deg}-10{\\deg} intervals), and total segment number (36-59 segment). The best dosimetric performance of mARC was observed at 10 MV photon energy and the point angle 6 degree, and 59 segments. The each treatment plans of three different techniques were compared with the followin...

  5. Unstable Behavior of Anodic Arc Discharge for Synthesis of Nanomaterials

    Science.gov (United States)

    Gershman, Sophia; Raitses, Yevgeny

    2016-09-01

    Fast imaging and electrical current measurements reveal unstable behavior of the carbon arc discharge for synthesis of nanomaterials. The arc column and the arc attachment region to the anode move in a somewhat sporadic way with a characteristic time in a 10-3 sec range. The arc exhibits a negative differential resistance before the arc motion occurs. A physical mechanism is proposed based on the thermal processes in the arc plasma region interacting with the ablating anode which leads to the shift of the arc to a new anode region. According to the transient heat transfer analysis, the time needed to heat a new anode region is also in a 10-3 sec range. For a 0.6 cm diameter anode used in our experiments, this time yields a frequency of about 200-300 Hz, comparable to the measured frequency of the arc motion. The voltage and current measurements show oscillations with a similar characteristic frequency. The thermal model is indirectly supported by the measured negative differential resistance of the arc discharge during arc oscillations. The observed unstable behavior of the arc may be responsible for the mixing of the flow of nanoparticles during the synthesis of nanoparticles leading to poor selectivity typical for the arc synthesis. The work was supported by US DOE under Contract No. DE-AC02-09CH11466.

  6. Process characteristics of fibre-laser-assisted plasma arc welding

    Energy Technology Data Exchange (ETDEWEB)

    Mahrle, A; Schnick, M; Rose, S; Demuth, C; Beyer, E; Fuessel, U, E-mail: achim.mahrle@iws.fraunhofer.de [Dresden University of Technology, Institute of Surface and Manufacturing Technology, PO Box, D-01062 Dresden (Germany)

    2011-08-31

    Experimental and theoretical investigations on fibre-laser-assisted plasma arc welding (LAPW) were performed. Welding experiments were carried out on aluminium and steel sheets. In the case of a highly focused laser beam and a separate arrangement of plasma torch and laser beam, high-speed video recordings of the plasma arc and corresponding measurements of the time-dependent arc voltage revealed differences in the process behaviour for both materials. In the case of aluminium welding, a sharp decline in arc voltage and stabilization and guiding of the anodic arc root was observed whereas in steel welding the arc voltage was slightly increased after the laser beam was switched on. However, significant improvement of the melting efficiency with the combined action of plasma arc and laser beam was achieved for both types of material. Theoretical results of additional numerical simulations of the arc behaviour suggest that the properties of the arc plasma are mainly influenced not by a direct interaction with the laser radiation but by the laser-induced evaporation of metal. Arc stabilization with increased current densities is predicted for moderate rates of evaporated metal only whereas metal vapour rates above a certain threshold causes a destabilization of the arc and reduced current densities along the arc axis.

  7. Optimal planning strategy among various arc arrangements for prostate stereotactic body radiotherapy with volumetric modulated arc therapy technique

    Directory of Open Access Journals (Sweden)

    Kang Sang Won

    2017-03-01

    Full Text Available The aim of this study was to determine the optimal strategy among various arc arrangements in prostate plans of stereotactic body radiotherapy with volumetric modulated arc therapy (SBRT-VMAT.

  8. Heart failure overview

    Science.gov (United States)

    ... symptoms) You feel a severe crushing chest pain Prevention Most cases of heart failure can be prevented by living a healthy lifestyle and taking steps aimed at reducing your risk for heart disease . . Alternative Names CHF; Congestive heart failure; Left-sided ...

  9. Driven Motion and Instability of an Atmospheric Pressure Arc

    Energy Technology Data Exchange (ETDEWEB)

    Max Karasik

    1999-12-01

    Atmospheric pressure arcs are used extensively in applications such as welding and metallurgy. However, comparatively little is known of the physics of such arcs in external magnetic fields and the mechanisms of the instabilities present. In order to address questions of equilibrium and stability of such arcs, an experimental arc furnace is constructed and operated in air with graphite cathode and steel anode at currents 100-250 A. The arc is diagnosed with a gated intensified camera and a collimated photodiode array, as well as fast voltage and current probes.

  10. [Heart failure and comorbidities].

    Science.gov (United States)

    Boully, Clémence; Hanon, Olivier

    2015-03-01

    Heart failure is a frequent disease in the elderly. Its clinical presentation is less typical and the prognosis more severe than in younger subjects because heart failure occurs in patients with multiple comorbidities. A comprehensive geriatric assessment should therefore be performed to detect the vulnerabilities and manage the comorbidities. The main diseases associated with heart failure are dementia, depression, malnutrition, atrial fibrillation, coronary artery disease, orthostatic hypotension, renal failure, anemia and iron deficiency. Comorbidities worsen heart failure and makes its treatment more difficult. The identification and treatment of comorbidities improve the prognosis in terms of mortality but especially in terms of quality of life. Caution with drugs is necessary because of pharmacokinetic or pharmacodynamic changes related to aging and the comorbidities. In this context, clinical and laboratory monitoring should be increased, mostly during an acute event (acute heart failure, infection, dehydration, fall, new therapy…). Therefore, the follow-up of elderly patients with heart failure requires a multidisciplinary approach that involves close cooperation between cardiologists, geriatricians, general practitioners, nurses, and pharmacists.

  11. Series and parallel arc-fault circuit interrupter tests.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay Dean; Fresquez, Armando J.; Gudgel, Bob; Meares, Andrew

    2013-07-01

    While the 2011 National Electrical Codeª (NEC) only requires series arc-fault protection, some arc-fault circuit interrupter (AFCI) manufacturers are designing products to detect and mitigate both series and parallel arc-faults. Sandia National Laboratories (SNL) has extensively investigated the electrical differences of series and parallel arc-faults and has offered possible classification and mitigation solutions. As part of this effort, Sandia National Laboratories has collaborated with MidNite Solar to create and test a 24-string combiner box with an AFCI which detects, differentiates, and de-energizes series and parallel arc-faults. In the case of the MidNite AFCI prototype, series arc-faults are mitigated by opening the PV strings, whereas parallel arc-faults are mitigated by shorting the array. A range of different experimental series and parallel arc-fault tests with the MidNite combiner box were performed at the Distributed Energy Technologies Laboratory (DETL) at SNL in Albuquerque, NM. In all the tests, the prototype de-energized the arc-faults in the time period required by the arc-fault circuit interrupt testing standard, UL 1699B. The experimental tests confirm series and parallel arc-faults can be successfully mitigated with a combiner box-integrated solution.

  12. BASIC THEORY AND APPLICATIONS OF WELDING ARC SPECTRAL INFORMATION

    Institute of Scientific and Technical Information of China (English)

    LI Junyue; XUE Haitao; LI Huan; SONG Yonglun

    2007-01-01

    Welding arc spectral information is a rising welding Information source. In some occasion, it can reflect many physical phenomena of welding process and solve many problems that cannot be done with arc electric information, acoustic information and other arc information. It is of important significance in developing automatic control technique of welding process and other similar process. Many years study work on welding arc spectral information of the anthor are discussed from three aspects of theory, method and application. Basic theory, view and testing methods of welding arc spectral information has been put forward. In application aspects, many applied examples, for example, monitoring of harmful gases in arc (such as hydrogen and nitrogen) with the method of welding arc spectral information; welding arc spectral imaging of thc welding pool which is used in automatic seam tracking; controlling of welding droplet transfer with welding arc spectral information and so on, are introduced. Especially, the successful application in real time controlling of welding droplet transfer in pulsed GMAW is introduced too. These application examples show that the welding arc spectral information has great applied significance and development potentialities. These content will play an important role in applying and spreading welding arc spectral information technology.

  13. NTWV-based sensing keyhole dimension in plasma arc welding

    Institute of Scientific and Technical Information of China (English)

    Jia Chuanbao; Wu Chuansong; Zhang Yuming

    2008-01-01

    During stable keyhole plasma arc welding, the pilot arc and the transferred arc exist at the meantime, and the arcs can be considered as a composition of two parts inside and outside the nozzle, respectively. Under the mechanical constriction and thermal contraction effects, the inside arc has certain arc length, electron density and arc profile etc. Inducing constant tungsten-to-nozzle voltage. However, the arc outside the nozzle diverges at about 5 degrees and has certain characteristics similar to the free arcs. The nozzle-to-workpiece voltage (NTWV) depends mainly on the length of the arc, which gets bigger as increasing of the weld penetration and keyhole size. The NTWV sensor is developed for monitoring NTWV in real time. The welding experiments are designed to get different penetrations and keyhole sizes. It is found that as the weld penetration and the keyhole size increase, NTWV also increases linearly. The NTWV signals can be used as the feedback variable in automatic control of keyhole plasma arc welding.

  14. Minimum-fuel rocket trajectories involving intermediate-thrust arcs

    Science.gov (United States)

    Breakwell, J. V.; Dixon, J. F.

    1975-01-01

    The optimal trajectories in the neighborhood of an optimal intermediate-thrust arc are investigated for the minimum-fuel orbit rendezvous problem with fixed specific impulse. Since such an arc is singular, the thrust acceleration magnitude being the singular control component, a second-variation analysis leads to the identification of a field of neighboring, singular arcs in a state space of dimension four rather than six, provided that a suitable Jacobi condition is met. A given neighboring initial six-dimensional state vector does not generally lie on a neighboring singular arc, and junction onto the appropriate singular arc must be accomplished by a short period of strong variations in the acceleration. The neighboring singular arc meets the final condition in 4 dimensions, rather than 6 dimensions, and rendezvous must be completed by another, terminal short period of strong variations in the acceleration. Implications for midcourse guidance near a singular arc are discussed.

  15. Discharge Characteristics of DC Arc Water Plasma for Environmental Applications

    Institute of Scientific and Technical Information of China (English)

    LI Tianming; Sooseok CHOI; Takayuki WATANABE

    2012-01-01

    A water plasma was generated by DC arc discharge with a hafnium embedded rodtype cathode and a nozzle-type anode. The discharge characteristics were examined by changing the operation parameter of the arc current. The dynamic behavior of the arc discharge led to significant fluctuations in the arc voltage and its frequency. Analyses of the high speed image and the arc voltage waveform showed that the arc discharge was in the restrike mode and its frequency varied within several tens of kilohertz according to the operating conditions. The larger thermal plasma volume was generated by the higher flow from the forming steam with a higher restrike frequency in the higher arc current conditions. In addition, the characteristics of the water plasma jet were investigated by means of optical emission spectroscopy to identify the abundant radicals required in an efficient waste treatment process.

  16. Damage mechanics - failure modes

    Energy Technology Data Exchange (ETDEWEB)

    Krajcinovic, D.; Vujosevic, M. [Arizona State Univ., Tempe, AZ (United States)

    1996-12-31

    The present study summarizes the results of the DOE sponsored research program focused on the brittle failure of solids with disordered microstructure. The failure is related to the stochastic processes on the microstructural scale; namely, the nucleation and growth of microcracks. The intrinsic failure modes, such as the percolation, localization and creep rupture, are studied by emphasizing the effect of the micro-structural disorder. A rich spectrum of physical phenomena and new concepts that emerges from this research demonstrates the reasons behind the limitations of traditional, deterministic, and local continuum models.

  17. Numerical modeling of transferred arc melting bath heating; Modelisation numerique du chauffage de bains par arc transfere

    Energy Technology Data Exchange (ETDEWEB)

    Bouvier, A. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches; Trenty, L.; Guillot, J.B. [Ecole Centrale de Paris, Laboratoire EM2C. CNRS, 92 - Chatenay-Malabry (France); Delalondre, C. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches

    1997-12-31

    This paper presents the modeling of a transferred electric arc inside a bath of melted metal. After a recall of the context of the study, the problem of the modeling, which involves magnetohydrodynamic coupling inside the arc and the bath, is described. The equations that govern the phenomena inside the arc and the bath are recalled and the approach used for the modeling of the anode region of the arc is explained using a 1-D sub-model. The conditions of connection between arc and bath calculations are explained and calculation results obtained with a 200 kW laboratory furnace geometry are presented. (J.S.) 8 refs.

  18. Plasma Arc Augmented CO2 laser welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Andersen, Mikkel; Frederiksen, Niels

    2001-01-01

    In order to reduce the hardness of laser beam welded 2.13 mm medium strength steel CMn 250, a plasma arc has been used simultaneously with a 2.6 kW CO2 laser source. In a number of systematic laboratory tests, the plasma arc current, plasma gas flow and distance to the laser source were varied...... with all laser parameters fixed. The welds were quality assessed and hardness measured transversely to the welding direction in the top, middle and root of the seam. In the seams welded by laser alone, hardness values between 275 and 304 HV1 were measured, about the double of the base material, 150 HV1...

  19. Examining properties of arc sprayed nanostructured coatings

    Directory of Open Access Journals (Sweden)

    A. Czupryński

    2016-04-01

    Full Text Available The article presents the results of examining properties of arc sprayed coating obtained with nano-alloy on the iron matrix with a high amount of fine carbide precipitates sprayed on non-alloyed steel plates intended for high temperature operation. Powder metal cored wire EnDOtec DO*390N 1,6 mm diameter, was used to produce, dense, very high abrasion and erosion resistant coatings approx. 1,0 mm thick. Nano-material coatings characterization was done to determine abrasion resistance, erosion resistance, adhesion strength, hardness as well as metallographic examinations. Results have proved high properties of arc sprayed nano-material coatings and have shown promising industrial applications.

  20. A pulsed cathodic arc spacecraft propulsion system

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, P R C; Bilek, M M M; Tarrant, R N; McKenzie, D R [School of Physics, University of Sydney, NSW 2006 Australia (Australia)

    2009-11-15

    We investigate the use of a centre-triggered cathodic arc as a spacecraft propulsion system that uses an inert solid as a source of plasma. The cathodic vacuum arc produces almost fully ionized plasma with a high exhaust velocity (>10{sup 4} m s{sup -1}), giving a specific impulse competitive with other plasma or ion thrusters. A centre trigger design is employed that enables efficient use of cathode material and a high pulse-to-pulse repeatability. We compare three anode geometries, two pulse current profiles and two pulse durations for their effects on impulse generation, energy and cathode material usage efficiency. Impulse measurement is achieved through the use of a free-swinging pendulum target constructed from a polymer material. Measurements show that impulse is accurately controlled by varying cathode current. The cylindrical anode gave the highest energy efficiency. Cathode usage is optimized by choosing a sawtooth current profile. There is no requirement for an exhaust charge neutralization system.

  1. Hybrid Arc Cell Studies: Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Berg J. S.

    2012-09-28

    I report on the status, at the end of FY12, of the studies of an arc cell for a hybrid synchrotron accelerating from 375 GeV/c to 750 GeV/c in momentum. Garren produced a complete lattice that gives a good outline of the structure of a hybrid synchrotron lattice. It is, however, lacking in some details: it does not maintain a constant time of flight, it lacks chromaticity correction, its cell structure is not ideal for removing aberrations from chromaticity correction, and it probably needs more space between magnets. I have begun studying cell structures for the arc cells to optimize the lattice performance and cost. I present some preliminary results for two magnets per half cell. I then discuss difficulties encountered, some preliminary attempts at resolving them, and the future plans for this work.

  2. Filtered cathodic arc deposition apparatus and method

    Science.gov (United States)

    Krauss, Alan R.

    1999-01-01

    A filtered cathodic arc deposition method and apparatus for the production of highly dense, wear resistant coatings which are free from macro particles. The filtered cathodic arc deposition apparatus includes a cross shaped vacuum chamber which houses a cathode target having an evaporable surface comprised of the coating material, means for generating a stream of plasma, means for generating a transverse magnetic field, and a macro particle deflector. The transverse magnetic field bends the generated stream of plasma in the direction of a substrate. Macro particles are effectively filtered from the stream of plasma by traveling, unaffected by the transverse magnetic field, along the initial path of the plasma stream to a macro particle deflector. The macro particle deflector has a preformed surface which deflects macro particles away from the substrate.

  3. Passive Visual Sensing in Automatic Arc Welding

    DEFF Research Database (Denmark)

    Liu, Jinchao

    For decades much work has been devoted to the research and development of automatic arc welding systems. However, it has remained a challenging problem. Besides the very complex arc welding process itself, the lack of ability to precisely sense the welding process, including the seam geometry...... industrial solutions for seam detection such as using laser scanners suer from several limitations. For instance, it must be positioned some distance ahead to the molten pool and may cause problem when dealing with shiny surfaces. Existing techniques for weld pool sensing mostly rely on auxiliary light...... on the weld pool and the nearby seam as the feedback to adjust the welding torch and/or welding parameters. It is an attractive idea from both academic and industrial point of view to develop a vision system without using any auxiliary light sources which can nevertheless extract relevant information. However...

  4. The singing arc: the oldest memristor?

    CERN Document Server

    Ginoux, Jean-Marc

    2014-01-01

    On April 30th 2008, the journal Nature announced that the missing circuit element, postulated thirty-seven years before by Professor Leon O. Chua has been found. Thus, after the capacitor, the resistor and the inductor, the existence of a fourth fundamental element of electronic circuits called "memristor" was established. In order to point out the importance of such a discovery, the aim of this article is first to propose an overview of the manner with which the three others have been invented during the past centuries. Then, a comparison between the main properties of the singing arc, i.e. a forerunner device of the triode used in Wireless Telegraphy, and that of the memristor will enable to state that the singing arc could be considered as the oldest memristor.

  5. Next generation high productivity submerged arc welding

    OpenAIRE

    LANGENOJA, MARKUS; Öhrvall Karlsson, Vincent

    2012-01-01

    The task of designing concepts for the next generation of submerged arc welding heads was given by ESAB. ESAB is a global company manufacturing welding equipment for a wide span of industries and uses. In October 2011, ESAB introduced a new technology called Integrated Cold Electrode™, abbreviated and trademarked as ICE™. ICE™ is a technique which utilizes three electrodes in a highly productive and stable process. The current state of the ICE™ technique focuses on welding thick plates with c...

  6. PSYCHOSOMATIC "ARC" IN THE PSYCHOTHERAPEUTIC PRACTICE

    OpenAIRE

    Ivanka Boncheva

    2012-01-01

    The psychoneuroimmunology, the new brain science and the endocrinology today show a lot of results, with which symptoms are better to understand. The psychotherapeutic practice shows the ways to influence them by encoding the levels of bounding between the physical symptom and the psychological condition. The aim of the study was to show the encoding of the psychosomatic arc within a real psychotherapeutic contact. 59 psychotherapeutic cases are followed. 33 of them were with somatoform disor...

  7. Heart failure - medicines

    Science.gov (United States)

    ... are working and to measure your potassium levels. Beta Blockers Beta blockers slow your heart rate and decrease the strength ... muscle contracts in the short term. Long term beta blockers help keep your heart failure from becoming worse. ...

  8. Hyperkalemia in Heart Failure.

    Science.gov (United States)

    Sarwar, Chaudhry M S; Papadimitriou, Lampros; Pitt, Bertram; Piña, Ileana; Zannad, Faiez; Anker, Stefan D; Gheorghiade, Mihai; Butler, Javed

    2016-10-01

    Disorders of potassium homeostasis can potentiate the already elevated risk of arrhythmia in heart failure. Heart failure patients have a high prevalence of chronic kidney disease, which further heightens the risk of hyperkalemia, especially when renin-angiotensin-aldosterone system inhibitors are used. Acute treatment for hyperkalemia may not be tolerated in the long term. Recent data for patiromer and sodium zirconium cyclosilicate, used to treat and prevent high serum potassium levels on a more chronic basis, have sparked interest in the treatment of hyperkalemia, as well as the potential use of renin-angiotensin-aldosterone system inhibitors in patients who were previously unable to take these drugs or tolerated only low doses. This review discusses the epidemiology, pathophysiology, and outcomes of hyperkalemia in heart failure; provides an overview of traditional and novel ways to approach management of hyperkalemia; and discusses the need for further research to optimally treat heart failure.

  9. Advanced Heart Failure

    Science.gov (United States)

    ... patients and their doctors, making good decisions requires teamwork. Through shared decision making, doctors and patients consider ... Heart Failure and Knowing Your Options Planning Ahead Communicating With Your Healthcare Provider Overcoming Barriers to Shared ...

  10. Effect of cathode model on arc attachment for short high-intensity arc on a refractory cathode

    Science.gov (United States)

    Javidi Shirvan, Alireza; Choquet, Isabelle; Nilsson, Håkan

    2016-12-01

    Various models coupling the refractory cathode, the cathode sheath and the arc at atmospheric pressure exist. They assume a homogeneous cathode with a uniform physical state, and differ by the cathode layer and the plasma arc model. However even the most advanced of these models still fail in predicting the extent of the arc attachment when applied to short high-intensity arcs such as gas tungsten arcs. Cathodes operating in these conditions present a non-uniform physical state. A model taking into account the first level of this non-homogeneity is proposed based on physical criteria. Calculations are done for 5 mm argon arcs with a thoriated tungsten cathode. The results obtained show that radiative heating and cooling of the cathode surface are of the same order. They also show that cathode inhomogeneity has a significant effect on the arc attachment, the arc temperature and pressure. When changing the arc current (100 A, 200 A) the proposed model allows predicting trends observed experimentally that cannot be captured by the homogeneous cathode model unless restricting a priori the size of the arc attachment. The cathode physics is thus an important element to include to obtain a comprehensive and predictive arc model.

  11. Water-vortex-stabilized electric arc: III. Radial energy transport, determination of water-vapour-boundary and arc performance

    Science.gov (United States)

    Jenista, Jirí

    2003-12-01

    This paper is concerned with numerical modelling of an electric arc stabilized by a water vortex. The two-dimensional axisymmetric model presented includes the arc discharge area between the cathode and the outlet nozzle of the water plasma torch. The aims of the numerical simulations are: (1) to assess the influence of radial position of the water-vapour-boundary in the discharge chamber on arc performance and overall radial energy transport within the arc; (2) to determine the most probable mass flow rates and radii of the water-vapour-boundary in the discharge chamber for a prescribed current; (3) to demonstrate arc performance for two radiation models involved; and (4) to estimate validity of local thermodynamic equilibrium (LTE) conditions within the arc column. The rate of evaporation of water is calculated from the conduction and radiation heat fluxes at the water vapour surface for the specified mass flow rate. The behaviour of such an arc has been studied for a range of current 300-600 A. It is shown that changes of bulk magnitudes of different terms in the momentum and energy equations within the arc column as a function of arc radius enable us to reveal transitions of temperature and velocity fields from one steady state to a qualitatively different one. The best fit between experiment and numerical simulation for all currents exists for the mean arc radius ~3.3 mm. Deviations from LTE within the arc column are estimated with the criteria for kinetic equilibrium and spatial temperature gradients.

  12. Arc-Induced Long Period Fiber Gratings

    Directory of Open Access Journals (Sweden)

    Gaspar Rego

    2016-01-01

    Full Text Available Long period fiber gratings produced by the electric arc technique have found an increasing interest by the scientific community due to their ease to fabricate, virtually enabling the inscription in any kind of fiber, low cost, and flexibility. In 2005 we have presented the first review on this subject. Since then, important achievements have been reached such as the identification of the mechanisms responsible for gratings formation, the type of symmetry, the conditions to increase fabrication reproducibility, and their inscription in the turning points with grating periods below 200 μm. Several interesting applications in the sensing area, including those sensors working in reflection, have been demonstrated and others are expected, namely, related to the monitoring of extreme temperatures, cryogenic and high temperatures, and high sensitivity refractometric sensors resulting from combining arc-induced gratings in the turning points and the deposition of thin films in the transition region. Therefore, due to its pertinence, in this paper we review the main achievements obtained concerning arc-induced long period fiber gratings, with special focus on the past ten years.

  13. Spiraling Fermi arcs in Weyl materials

    Science.gov (United States)

    Li, Songci; Andreev, Anton

    In Weyl materials the valence and conduction electron bands touch at an even number of isolated points in the Brillouin zone. In the vicinity of these points the electron dispersion is linear and may be described by the massless Dirac equation. This results in nontrivial topology of Berry connection curvature. One of its consequences is the existence of peculiar surface electron states whose Fermi surfaces form arcs connecting projections of the Weyl points onto the surface plane. Band bending near the boundary of the crystal also produces surface states. We show that in Weyl materials band bending near the crystal surface gives rise to spiral structure of energy surfaces of arc states. The corresponding Fermi surface has the shape of a spiral that winds about the projection of the Weyl point onto the surface plane. The direction of the winding is determined by the helicity of the Weyl point and the sign of the band bending potential. For close valleys arc state morphology may be understood in terms of avoided crossing of oppositely winding spirals. This work is supported by the U.S. Department of Energy Office of Science, Basic Energy Sciences under Award Number DE-FG02-07ER46452.

  14. Optical diagnostics of a gliding arc.

    Science.gov (United States)

    Sun, Z W; Zhu, J J; Li, Z S; Aldén, M; Leipold, F; Salewski, M; Kusano, Y

    2013-03-11

    Dynamic processes in a gliding arc plasma generated between two diverging electrodes in ambient air driven by 31.25 kHz AC voltage were investigated using spatially and temporally resolved optical techniques. The life cycles of the gliding arc were tracked in fast movies using a high-speed camera with framing rates of tens to hundreds of kHz, showing details of ignition, motion, pulsation, short-cutting, and extinction of the plasma column. The ignition of a new discharge occurs before the extinction of the previous discharge. The developed, moving plasma column often short-cuts its current path triggered by Townsend breakdown between the two legs of the gliding arc. The emission from the plasma column is shown to pulsate at a frequency of 62.5 kHz, i.e., twice the frequency of the AC power supply. Optical emission spectra of the plasma radiation show the presence of excited N2, NO and OH radicals generated in the plasma and the dependence of their relative intensities on both the distance relative to the electrodes and the phase of the driving AC power. Planar laser-induced fluorescence of the ground-state OH radicals shows high intensity outside the plasma column rather than in the center suggesting that ground-state OH is not formed in the plasma column but in its vicinity.

  15. GlidArc-assisted processing of biogas

    Energy Technology Data Exchange (ETDEWEB)

    Czernichowski, A.; Wesolowska, K. (ECP, La Ferte St Aubin (France)), Email: echph@wanadoo.fr

    2009-07-01

    Power generation or chemical applications of biogas can be difficult when CH{sub 4} content is too low and / or in the presence of sulphur compounds. We therefore propose two reformers based on electric discharges (GlidArc) that strike directly either in a poor biogas or in waste CO{sub 2} + H{sub 2}S mixture generated during biogas cleaning. Direct application of GlidArc discharges to the poor biogas enhances its flammability through a partial conversion of CH{sub 4} + CO{sub 2} into hydrogen and carbon monoxide (synthesis gas). Any level of sulphur (and other impurities) is accepted. Roughly 40 % of injected electric power is transferred into upgraded biogas as its additional chemical enthalpy. A few percent of resultant H{sub 2} and CO inside the biogas makes it more flammable, and therefore better to fuel an engine or gas turbine. As a result of biogas purification via amines-washing technologies, one gets concentrated pollutants in CO{sub 2} matrix. Instead of classical neutralisation, we propose H{sub 2}Svalorisation through the SulfArc process converting all H{sub 2}S into additional amounts of synthesis gas, while neutral elemental sulphur is removed from the system. Generated syngas can be injected into the main biogas flow to enhance its flammability. (orig.)

  16. Longitudinal development of a substorm brightening arc

    Directory of Open Access Journals (Sweden)

    K. Shiokawa

    2009-05-01

    Full Text Available We present simultaneous THEMIS-ground observations of longitudinal (eastward extension of a substorm initial-brightening arc at Gillam (magnetic latitude: 65.6° at 08:13 UT on 10 January 2008. The speed of the eastward arc extension was ~2.7 km/s. The extension took place very close to the footprints of the longitudinally separated THEMIS E and D satellites at ~12 RE. The THEMIS satellites observed field dipolarization, weak earthward flow, and pressure increase, which propagated eastward from E to D at a speed of ~50 km/s. The THEMIS A satellite, located at 1.6 RE earthward of THEMIS E, observed fluctuating magnetic field during and after the dipolarization. The THEMIS E/D observations suggest that the longitudinal extension of the brightening arc at substorm onset is caused by earthward flow braking processes which produce field dipolarization and pressure increase propagating in longitude in the near-earth plasma sheet.

  17. Arc melter demonstration baseline test results

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; Oden, L.L.; O`Connor, W.K.; Turner, P.C.

    1994-07-01

    This report describes the test results and evaluation for the Phase 1 (baseline) arc melter vitrification test series conducted for the Buried Waste Integrated Demonstration program (BWID). Phase 1 tests were conducted on surrogate mixtures of as-incinerated wastes and soil. Some buried wastes, soils, and stored wastes at the INEL and other DOE sites, are contaminated with transuranic (TRU) radionuclides and hazardous organics and metals. The high temperature environment in an electric arc furnace may be used to process these wastes to produce materials suitable for final disposal. An electric arc furnace system can treat heterogeneous wastes and contaminated soils by (a) dissolving and retaining TRU elements and selected toxic metals as oxides in the slag phase, (b) destroying organic materials by dissociation, pyrolyzation, and combustion, and (c) capturing separated volatilized metals in the offgas system for further treatment. Structural metals in the waste may be melted and tapped separately for recycle or disposal, or these metals may be oxidized and dissolved into the slag. The molten slag, after cooling, will provide a glass/ceramic final waste form that is homogeneous, highly nonleachable, and extremely durable. These features make this waste form suitable for immobilization of TRU radionuclides and toxic metals for geologic timeframes. Further, the volume of contaminated wastes and soils will be substantially reduced in the process.

  18. Preliminary photovoltaic arc-fault prognostic tests using sacrificial fiber optic cabling.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay Dean; Blemel, Kenneth D.; Peter, Francis

    2013-02-01

    Through the New Mexico Small Business Assistance Program, Sandia National Laboratories worked with Sentient Business Systems, Inc. to develop and test a novel photovoltaic (PV) arc-fault detection system. The system operates by pairing translucent polymeric fiber optic sensors with electrical circuitry so that any external abrasion to the system or internal heating causes the fiber optic connection to fail or detectably degrade. A periodic pulse of light is sent through the optical path using a transmitter-receiver pair. If the receiver does not detect the pulse, an alarm is sounded and the PV system can be de-energized. This technology has the unique ability to prognostically determine impending failures to the electrical system in two ways: (a) the optical connection is severed prior to physical abrasion or cutting of PV DC electrical conductors, and (b) the polymeric fiber optic cable melts via Joule heating before an arc-fault is established through corrosion. Three arc-faults were created in different configurations found in PV systems with the integrated fiber optic system to determine the feasibility of the technology. In each case, the fiber optic cable was broken and the system annunciated the fault.

  19. Renal failure (chronic)

    OpenAIRE

    Clase, Catherine

    2011-01-01

    Chronic renal failure is characterised by a gradual and sustained decline in renal clearance or glomerular filtration rate (GFR). Continued progression of renal failure will lead to renal function too low to sustain healthy life. In developed countries, such people will be offered renal replacement therapy in the form of dialysis or renal transplantation. Requirement for dialysis or transplantation is termed end-stage renal disease (ESRD).Diabetes, glomerulonephritis, hypertension, pyelone...

  20. Lungs in Heart Failure

    Directory of Open Access Journals (Sweden)

    Anna Apostolo

    2012-01-01

    Full Text Available Lung function abnormalities both at rest and during exercise are frequently observed in patients with chronic heart failure, also in the absence of respiratory disease. Alterations of respiratory mechanics and of gas exchange capacity are strictly related to heart failure. Severe heart failure patients often show a restrictive respiratory pattern, secondary to heart enlargement and increased lung fluids, and impairment of alveolar-capillary gas diffusion, mainly due to an increased resistance to molecular diffusion across the alveolar capillary membrane. Reduced gas diffusion contributes to exercise intolerance and to a worse prognosis. Cardiopulmonary exercise test is considered the “gold standard” when studying the cardiovascular, pulmonary, and metabolic adaptations to exercise in cardiac patients. During exercise, hyperventilation and consequent reduction of ventilation efficiency are often observed in heart failure patients, resulting in an increased slope of ventilation/carbon dioxide (VE/VCO2 relationship. Ventilatory efficiency is as strong prognostic and an important stratification marker. This paper describes the pulmonary abnormalities at rest and during exercise in the patients with heart failure, highlighting the principal diagnostic tools for evaluation of lungs function, the possible pharmacological interventions, and the parameters that could be useful in prognostic assessment of heart failure patients.

  1. Arc Facilities Manager (ArcFM)-ARC/INFO的功能强大的公用事业应用程序%Arc Facilities Manager(ArcFM)-A Powerful ARC/INFO-Based Application for

    Institute of Scientific and Technical Information of China (English)

    陆朝晖; 赵小红; 朱晓岷

    2000-01-01

    市场经济条件下公用事业面临新的挑战,地理信息系统(GIS)有助于公用事业有效管理公用设施,从而在竞争中获得优势.围绕ESRI公司的ArcFM软件,从它的结构、性能和功能等几方面,阐述了公用事业管理系统的一种解决方案.

  2. Arc Jet Facility Test Condition Predictions Using the ADSI Code

    Science.gov (United States)

    Palmer, Grant; Prabhu, Dinesh; Terrazas-Salinas, Imelda

    2015-01-01

    The Aerothermal Design Space Interpolation (ADSI) tool is used to interpolate databases of previously computed computational fluid dynamic solutions for test articles in a NASA Ames arc jet facility. The arc jet databases are generated using an Navier-Stokes flow solver using previously determined best practices. The arc jet mass flow rates and arc currents used to discretize the database are chosen to span the operating conditions possible in the arc jet, and are based on previous arc jet experimental conditions where possible. The ADSI code is a database interpolation, manipulation, and examination tool that can be used to estimate the stagnation point pressure and heating rate for user-specified values of arc jet mass flow rate and arc current. The interpolation is performed in the other direction (predicting mass flow and current to achieve a desired stagnation point pressure and heating rate). ADSI is also used to generate 2-D response surfaces of stagnation point pressure and heating rate as a function of mass flow rate and arc current (or vice versa). Arc jet test data is used to assess the predictive capability of the ADSI code.

  3. Characteristics of Atmospheric Pressure Rotating Gliding Arc Plasmas

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hao; ZHU Fengsen; TU Xin; BO Zheng; CEN Kefa; LI Xiaodong

    2016-01-01

    In this work,a novel direct current (DC) atmospheric pressure rotating gliding arc (RGA) plasma reactor has been developed for plasma-assisted chemical reactions.The influence of the gas composition and the gas flow rate on the arc dynamic behaviour and the formation of reactive species in the N2 and air gliding arc plasmas has been investigated by means of electrical signals,high speed photography,and optical emission spectroscopic diagnostics.Compared to conventional gliding arc reactors with knife-shaped electrodes which generally require a high flow rate (e.g.,10-20 L/min) to maintain a long arc length and reasonable plasma discharge zone,in this RGA system,a lower gas flow rate (e.g.,2 L/min) can also generate a larger effective plasma reaction zone with a longer arc length for chemical reactions.Two different motion patterns can be clearly observed in the N2 and air RGA plasmas.The time-resolved arc voltage signals show that three different arc dynamic modes,the arc restrike mode,takeover mode,and combined modes,can be clearly identified in the RGA plasmas.The occurrence of different motion and arc dynamic modes is strongly dependent on the composition of the working gas and gas flow rate.

  4. Characteristics of Atmospheric Pressure Rotating Gliding Arc Plasmas

    Science.gov (United States)

    Zhang, Hao; Zhu, Fengsen; Tu, Xin; Bo, Zheng; Cen, Kefa; Li, Xiaodong

    2016-05-01

    In this work, a novel direct current (DC) atmospheric pressure rotating gliding arc (RGA) plasma reactor has been developed for plasma-assisted chemical reactions. The influence of the gas composition and the gas flow rate on the arc dynamic behaviour and the formation of reactive species in the N2 and air gliding arc plasmas has been investigated by means of electrical signals, high speed photography, and optical emission spectroscopic diagnostics. Compared to conventional gliding arc reactors with knife-shaped electrodes which generally require a high flow rate (e.g., 10-20 L/min) to maintain a long arc length and reasonable plasma discharge zone, in this RGA system, a lower gas flow rate (e.g., 2 L/min) can also generate a larger effective plasma reaction zone with a longer arc length for chemical reactions. Two different motion patterns can be clearly observed in the N2 and air RGA plasmas. The time-resolved arc voltage signals show that three different arc dynamic modes, the arc restrike mode, takeover mode, and combined modes, can be clearly identified in the RGA plasmas. The occurrence of different motion and arc dynamic modes is strongly dependent on the composition of the working gas and gas flow rate. supported by National Natural Science Foundation of China (No. 51576174), the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20120101110099) and the Fundamental Research Funds for the Central Universities (No. 2015FZA4011)

  5. Numerical modeling of volcanic arc development

    Science.gov (United States)

    Gerya, T.; Gorczyk, W.; Nikolaeva, K.

    2007-05-01

    We have created a new coupled geochemical-petrological-thermomechanical numerical model of subduction associated with volcanic arc development. The model includes spontaneous slab bending, subducted crust dehydration, aqueous fluid transport, mantle wedge melting and melt extraction resulting in crustal growth. Two major volcanic arc settings are modeled so far: active continental margins, and intraoceanic subduction. In case of Pacific-type continental margin two fundamentally different regimes of melt productivity are observed in numerical experiments which are in line with natural observations: (1) During continuous convergence with coupled plates highest amounts of melts are formed immediately after the initiation of subduction and then decrease rapidly with time due to the steepening of the slab inclination angle precluding formation of partially molten mantle wedge plumes; (2) During subduction associated with slab delamination and trench retreat resulting in the formation of a pronounced back arc basin with a spreading center in the middle melt production increases with time due to shallowing/stabilization of slab inclination associated with upward asthenospheric mantle flow toward the extension region facilitating propagation of hydrous partially molten plumes from the slab. In case of spontaneous nucleation of retreating oceanic subduction two scenarios of tecono-magmatic evolution are distinguished: (1) decay and, ultimately, the cessation of subduction and related magmatic activity, (2) increase in subduction rate (to up to ~12 cm/yr) and stabilization of subduction and magmatic arc growth. In the first case the duration of subduction correlates positively with the intensity of melt extraction: the period of continued subduction increases from 15,4 Myrs to 47,6 Myrs with the increase of melt extraction threshold from 1% to 9%. In scenario (1) the magmatic arc crust includes large amounts of rocks formed by melting of subducted crust atop the thermally

  6. Single Arc Volumetric Modulated Arc Therapy of head and neck cancer

    DEFF Research Database (Denmark)

    Bertelsen, Anders; Hansen, Christian Rønn; Johansen, Jørgen;

    2010-01-01

    BACKGROUND: The quality of Volumetric Modulated Arc Therapy (VMAT) plans is highly dependent on the performance of the optimization algorithm used. Recently new algorithms have become available which are capable of generating VMAT plans for Elekta accelerators. The VMAT algorithm in Pinnacle...... is named SmartArc and its capability to generate treatment plans for head and neck cancer was tested. METHODS: Twenty-five patients with oropharyngeal or hypopharyngeal carcinoma, previously treated with IMRT by means of Pinnacle and Elekta accelerators, were replanned with single arc VMAT. The VMAT....... RESULTS: Equivalent or superior target coverage and sparing of OARs were achieved with VMAT compared to IMRT. Volumes in the healthy tissues receiving between 17.3 Gy and 49.4 Gy were significantly reduced and the conformity (CI(95%)) of the elective PTV was improved from 1.7 with IMRT to 1.6 with VMAT...

  7. Fluid Flow Modeling of Arc Plasma and Bath Circulation in DC Electric Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    WANG Feng-hua; JIN Zhi-jian; ZHU Zi-shu

    2006-01-01

    A mathematical model describing the flow field, heat transfer and the electromagnetic phenomenon in a DC electric arc furnace has been developed. First the governing equations in the arc plasma region are solved and the calculated results of heat transfer, current density and shear stresses on the anode surface are used as boundary conditions in a model of molten bath. Then a two-dimensional time-dependent model is used to describe the flow field and electromagnetic phenomenon in the molten bath. Moreover, the effect of bottom electrode diameter on the circulation of molten bath is studied.

  8. Application of Python in ArcGIS%Python在ArcGIS中的应用

    Institute of Scientific and Technical Information of China (English)

    朱道强; 关海涛

    2013-01-01

    通过简要介绍利用Python语言编写脚本在ArcGIS中进行数据批处理的基础方法,提出了一种减轻现今数据生产中作业人员进行数据处理强度的方法.%Through a brief introduction on the use of Python language data batch processing based method for script in ArcGIS,thus put forward the method to reduce the data in the production operation personnel data processing strength.

  9. Improving Weld Quality by Arc-Excited Ultrasonic Treatment

    Institute of Scientific and Technical Information of China (English)

    张春雷; 吴敏生; 杜敬磊

    2001-01-01

    Ultrasonic treatment of the solidifying metal is a promising method for improving the quality of fusion welding. A method to combine the ultrasonic waves to the welding process using arc-excited ultrasonic emission, called arc-ultrasonic, was high frequency modulation of the arc-plasma. The effects of arc-ultrasonic on the weld including the fusion zone, the partially melted zone and the heat-affected zone are described. The arc-ultrasonic energy changes the weld microstructure. In the fusion zone, the primary dendrite arm spacing decreases significantly and more acicular ferrite appears. In the partially melted zone, a large amount of fine grains appear. In the heat-affected zone, the width of the tempered zone increases with increasing modulation frequency and the microstructure is refined. The results show that arc-ultrasonic is a new and effective way for improving weld quality.

  10. Optical arc sensor using energy harvesting power source

    Science.gov (United States)

    Choi, Kyoo Nam; Rho, Hee Hyuk

    2016-06-01

    Wireless sensors without external power supply gained considerable attention due to convenience both in installation and operation. Optical arc detecting sensor equipping with self sustaining power supply using energy harvesting method was investigated. Continuous energy harvesting method was attempted using thermoelectric generator to supply standby power in micro ampere scale and operating power in mA scale. Peltier module with heat-sink was used for high efficiency electricity generator. Optical arc detecting sensor with hybrid filter showed insensitivity to fluorescent and incandescent lamps under simulated distribution panel condition. Signal processing using integrating function showed selective arc discharge detection capability to different arc energy levels, with a resolution below 17J energy difference, unaffected by bursting arc waveform. The sensor showed possibility for application to arc discharge detecting sensor in power distribution panel. Also experiment with proposed continuous energy harvesting method using thermoelectric power showed possibility as a self sustainable power source of remote sensor.

  11. Computational Modeling of Arc-Slag Interaction in DC Furnaces

    Science.gov (United States)

    Reynolds, Quinn G.

    2016-11-01

    The plasma arc is central to the operation of the direct-current arc furnace, a unit operation commonly used in high-temperature processing of both primary ores and recycled metals. The arc is a high-velocity, high-temperature jet of ionized gas created and sustained by interactions among the thermal, momentum, and electromagnetic fields resulting from the passage of electric current. In addition to being the primary source of thermal energy, the arc jet also couples mechanically with the bath of molten process material within the furnace, causing substantial splashing and stirring in the region in which it impinges. The arc's interaction with the molten bath inside the furnace is studied through use of a multiphase, multiphysics computational magnetohydrodynamic model developed in the OpenFOAM® framework. Results from the computational solver are compared with empirical correlations that account for arc-slag interaction effects.

  12. Computational Modeling of Arc-Slag Interaction in DC Furnaces

    Science.gov (United States)

    Reynolds, Quinn G.

    2017-02-01

    The plasma arc is central to the operation of the direct-current arc furnace, a unit operation commonly used in high-temperature processing of both primary ores and recycled metals. The arc is a high-velocity, high-temperature jet of ionized gas created and sustained by interactions among the thermal, momentum, and electromagnetic fields resulting from the passage of electric current. In addition to being the primary source of thermal energy, the arc jet also couples mechanically with the bath of molten process material within the furnace, causing substantial splashing and stirring in the region in which it impinges. The arc's interaction with the molten bath inside the furnace is studied through use of a multiphase, multiphysics computational magnetohydrodynamic model developed in the OpenFOAM® framework. Results from the computational solver are compared with empirical correlations that account for arc-slag interaction effects.

  13. Ejection Fraction Heart Failure Measurement

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Ejection Fraction Heart Failure Measurement Updated:Feb 15,2017 The ejection fraction ( ... failure This content was last reviewed April 2015. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

  14. Ductile failure modeling

    DEFF Research Database (Denmark)

    Benzerga, Ahmed Amine; Leblond, Jean Baptiste; Needleman, Alan

    2016-01-01

    anisotropy, or the influence of nonlocal effects that bring a material size scale into the models. Often the voids are not present in the material from the beginning, and realistic nucleation models are important. The final failure process by coalescence of neighboring voids is an issue that has been given......Ductile fracture of structural metals occurs mainly by the nucleation, growth and coalescence of voids. Here an overview of continuum models for this type of failure is given. The most widely used current framework is described and its limitations discussed. Much work has focused on extending void...... growth models to account for non-spherical initial void shapes and for shape changes during growth. This includes cases of very low stress triaxiality, where the voids can close up to micro-cracks during the failure process. The void growth models have also been extended to consider the effect of plastic...

  15. BIOASSAY VESSEL FAILURE ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Vormelker, P

    2008-09-22

    Two high-pressure bioassay vessels failed at the Savannah River Site during a microwave heating process for biosample testing. Improper installation of the thermal shield in the first failure caused the vessel to burst during microwave heating. The second vessel failure is attributed to overpressurization during a test run. Vessel failure appeared to initiate in the mold parting line, the thinnest cross-section of the octagonal vessel. No material flaws were found in the vessel that would impair its structural performance. Content weight should be minimized to reduce operating temperature and pressure. Outer vessel life is dependent on actual temperature exposure. Since thermal aging of the vessels can be detrimental to their performance, it was recommended that the vessels be used for a limited number of cycles to be determined by additional testing.

  16. Particle tracking velocimetry of a gliding arc discharge

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas;

    2014-01-01

    A 35 kHz AC gliding arc discharge at atmospheric pressure is generated between two diverging electrodes and extended by an air flow. The gas flow velocity is measured by particle tracking velocimetry (PTV) while the moving velocity of the plasma column of the gliding arc discharge is measured...... by analyzing the movie taken by a high-speed camera. The two-dimensional velocity vector of the gas flow and of the gliding arc in the imaging plane was determined....

  17. Process characteristics of fibre-laser-assisted plasma arc welding

    OpenAIRE

    Mahrle, A; SCHNICK, M; Rose, S; Demuth, C; Beyer, E.; Füssel, U

    2011-01-01

    Abstract Experimental and theoretical investigations on fibre-laser assisted plasma arc welding (LAPW) have been performed. Welding experiments were carried out on aluminium and steel sheets. In case of a highly focused laser beam and a separate arrangement of plasma torch and laser beam, high-speed video recordings of the plasma arc and corresponding measurements of the time-dependent arc voltage revealed differences in the process behaviour for both materials. In case of aluminium weldin...

  18. Liquid-Arc/Spark-Excitation Atomic-Emission Spectroscopy

    Science.gov (United States)

    Schlagen, Kenneth J.

    1992-01-01

    Constituents of solutions identified in situ. Liquid-arc/spark-excitation atomic-emission spectroscopy (LAES) is experimental variant of atomic-emission spectroscopy in which electric arc or spark established in liquid and spectrum of light from arc or spark analyzed to identify chemical elements in liquid. Observations encourage development of LAES equipment for online monitoring of process streams in such industries as metal plating, electronics, and steel, and for online monitoring of streams affecting environment.

  19. Programming ArcGIS 10.1 with Python cookbook

    CERN Document Server

    Pimpler, Eric

    2013-01-01

    This book is written in a helpful, practical style with numerous hands-on recipes and chapters to help you save time and effort by using Python to power ArcGIS to create shortcuts, scripts, tools, and customizations.""Programming ArcGIS 10.1 with Python Cookbook"" is written for GIS professionals who wish to revolutionize their ArcGIS workflow with Python. Basic Python or programming knowledge is essential(?).

  20. Fluctuation Phenomenon Analysis of an Arc Plasma Spraying Jet

    Institute of Scientific and Technical Information of China (English)

    赵文华; 田阔; 刘笛; 张冠忠

    2001-01-01

    The effects of three factors, including the power supply, the arc behaviour in the arc channel and the fluid dynamic process of the jet, on a plasma spraying jet have been experimentally detected by means of spectroscopic diagnostic techniques. The fast Fourier transform method has been applied to the analysis of the arc voltage and spectral line intensity of the jet. The three factors have been studied and distinguished from each other.

  1. Unusual Cathode Erosion Patterns Observed for Steered Arc Sources

    CERN Document Server

    Kolbeck, Jonathan

    2014-01-01

    A cathodic arc source with a magnetron-type magnetic field was investigated for stability, erosion, and compatibility with a linear macroparticle filter. Here we report about unusual arc spot erosion patterns, which were narrow (~ 2 mm) with periodic pits when operating in argon, and broad (~ 10 mm) with periodic groves and ridges when operating in an argon and oxygen mixtures. These observations can be correlated with the ignition probability for type 2 and type 1 arc spots, respectively.

  2. A note on the arc elacticity of demand

    OpenAIRE

    Andrés Vázquez

    1995-01-01

    This note presents a simple alternative measure for the arc elasticity of demand which comes naturally and does retain the salient characteristics of the point demand elasticity. A remarkable feature is that it equals the point demand elasticity at some point inside the interval, thus leading to the exact estimation of the point demand elasticity when this is constant. It also ensures that the relationships between the arc demand elasticity and the arc revenue elasticities keep exact formal a...

  3. THE DETECTION AND STATISTICS OF GIANT ARCS BEHIND CLASH CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bingxiao; Zheng, Wei [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Postman, Marc; Bradley, Larry [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Meneghetti, Massimo; Koekemoer, Anton [INAF, Osservatorio Astronomico di Bologna, and INFN, Sezione di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Seitz, Stella [Universitaets-Sternwarte, Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Zitrin, Adi [California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Merten, Julian [University of Oxford, Department of Physics, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Maoz, Dani [School of Physics and Astronomy, Tel Aviv University, Tel-Aviv 69978 (Israel); Frye, Brenda [Steward Observatory/Department of Astronomy, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Umetsu, Keiichi [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Vega, Jesus, E-mail: bxu6@jhu.edu [Universidad Autonoma de Madrid, Ciudad Universitaria de Cantoblanco, E-28049 Madrid (Spain)

    2016-02-01

    We developed an algorithm to find and characterize gravitationally lensed galaxies (arcs) to perform a comparison of the observed and simulated arc abundance. Observations are from the Cluster Lensing And Supernova survey with Hubble (CLASH). Simulated CLASH images are created using the MOKA package and also clusters selected from the high-resolution, hydrodynamical simulations, MUSIC, over the same mass and redshift range as the CLASH sample. The algorithm's arc elongation accuracy, completeness, and false positive rate are determined and used to compute an estimate of the true arc abundance. We derive a lensing efficiency of 4 ± 1 arcs (with length ≥6″ and length-to-width ratio ≥7) per cluster for the X-ray-selected CLASH sample, 4 ± 1 arcs per cluster for the MOKA-simulated sample, and 3 ± 1 arcs per cluster for the MUSIC-simulated sample. The observed and simulated arc statistics are in full agreement. We measure the photometric redshifts of all detected arcs and find a median redshift z{sub s} = 1.9 with 33% of the detected arcs having z{sub s} > 3. We find that the arc abundance does not depend strongly on the source redshift distribution but is sensitive to the mass distribution of the dark matter halos (e.g., the c–M relation). Our results show that consistency between the observed and simulated distributions of lensed arc sizes and axial ratios can be achieved by using cluster-lensing simulations that are carefully matched to the selection criteria used in the observations.

  4. Exposure assessment of aluminum arc welding radiation.

    Science.gov (United States)

    Peng, Chiung-yu; Lan, Cheng-hang; Juang, Yow-jer; Tsao, Ta-ho; Dai, Yu-tung; Liu, Hung-hsin; Chen, Chiou-jong

    2007-10-01

    The purpose of this study is to evaluate the non-ionizing radiation (NIR) exposure, especially optical radiation levels, and potential health hazard from aluminum arc welding processes based on the American Conference of Governmental Industrial Hygienists (ACGIH) method. The irradiance from the optical radiation emissions can be calculated with various biological effective parameters [i.e., S(lambda), B(lambda), R(lambda)] for NIR hazard assessments. The aluminum arc welding processing scatters bright light with NIR emission including ultraviolet radiation (UVR), visible, and infrared spectra. The UVR effective irradiance (Eeff) has a mean value of 1,100 microW cm at 100 cm distance from the arc spot. The maximum allowance time (tmax) is 2.79 s according to the ACGIH guideline. Blue-light hazard effective irradiance (EBlue) has a mean value of 1840 microW cm (300-700 nm) at 100 cm with a tmax of 5.45 s exposure allowance. Retinal thermal hazard effective calculation shows mean values of 320 mW cm(-2) sr(-1) and 25.4 mW (cm-2) (380-875 nm) for LRetina (spectral radiance) and ERetina (spectral irradiance), respectively. From this study, the NIR measurement from welding optical radiation emissions has been established to evaluate separate types of hazards to the eye and skin simultaneously. The NIR exposure assessment can be applied to other optical emissions from industrial sources. The data from welding assessment strongly suggest employees involved in aluminum welding processing must be fitted with appropriate personal protection devices such as masks and gloves to prevent serious injuries of the skin and eyes upon intense optical exposure.

  5. Treatment planning for volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bedford, James L. [Joint Department of Physics, Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom)

    2009-11-15

    Purpose: Volumetric modulated arc therapy (VMAT) is a specific type of intensity-modulated radiation therapy (IMRT) in which the gantry speed, multileaf collimator (MLC) leaf position, and dose rate vary continuously during delivery. A treatment planning system for VMAT is presented. Methods: Arc control points are created uniformly throughout one or more arcs. An iterative least-squares algorithm is used to generate a fluence profile at every control point. The control points are then grouped and all of the control points in a given group are used to approximate the fluence profiles. A direct-aperture optimization is then used to improve the solution, taking into account the allowed range of leaf motion of the MLC. Dose is calculated using a fast convolution algorithm and the motion between control points is approximated by 100 interpolated dose calculation points. The method has been applied to five cases, consisting of lung, rectum, prostate and seminal vesicles, prostate and pelvic lymph nodes, and head and neck. The resulting plans have been compared with segmental (step-and-shoot) IMRT and delivered and verified on an Elekta Synergy to ensure practicality. Results: For the lung, prostate and seminal vesicles, and rectum cases, VMAT provides a plan of similar quality to segmental IMRT but with faster delivery by up to a factor of 4. For the prostate and pelvic nodes and head-and-neck cases, the critical structure doses are reduced with VMAT, both of these cases having a longer delivery time than IMRT. The plans in general verify successfully, although the agreement between planned and measured doses is not very close for the more complex cases, particularly the head-and-neck case. Conclusions: Depending upon the emphasis in the treatment planning, VMAT provides treatment plans which are higher in quality and/or faster to deliver than IMRT. The scheme described has been successfully introduced into clinical use.

  6. A New Survey for Giant Arcs

    Energy Technology Data Exchange (ETDEWEB)

    Hennawi, Joseph F.; Gladders, Michael D.; Oguri, Masamune; Dalal, Neal; Koester, Benjamin; Natarajan, Priyamvada; Strauss, Michael A.; Inada, Naohisa; Kayo, Issha; Lin,; Lampeitl, Hubert; Annis, James; Bahcall, Neta A.; Schneider, Donald P.

    2006-11-15

    We report on the first results of an imaging survey to detect strong gravitational lensing targeting the richest clusters selected from the photometric data of the Sloan Digital Sky Survey (SDSS) with follow-up deep imaging observations from the Wisconsin Indiana Yale NOAO (WIYN) 3.5m telescope and the University of Hawaii 88-inch telescope (UH88). The clusters are selected from an area of 8000 deg{sup 2} using the Red Cluster Sequence technique and span the redshift range 0.1 {approx}< z {approx}< 0.6, corresponding to a comoving cosmological volume of {approx} 2Gpc{sup 3}. Our imaging survey thus targets a volume more than an order of magnitude larger than any previous search. A total of 240 clusters were imaged of which 141 had sub-arcsecond image quality. Our survey has uncovered 16 new lensing clusters with definite giant arcs, an additional 12 systems for which the lensing interpretation is very likely, and 9 possible lenses which contain shorter arclets or candidate arcs which are less certain and will require further observations to confirm their lensing origin. The number of new cluster lenses detected in this survey is likely > 30. Among these new systems are several of the most dramatic examples of strong gravitational lensing ever discovered with multiple bright arcs at large angular separation. These will likely become 'poster-child' gravitational lenses similar to Abell 1689 and CL0024+1654. The new lenses discovered in this survey will enable future systematic studies of the statistics of strong lensing and its implications for cosmology and our structure formation paradigm.

  7. Partial Arc Curvilinear Direct Drive Servomotor

    Science.gov (United States)

    Sun, Xiuhong (Inventor)

    2014-01-01

    A partial arc servomotor assembly having a curvilinear U-channel with two parallel rare earth permanent magnet plates facing each other and a pivoted ironless three phase coil armature winding moves between the plates. An encoder read head is fixed to a mounting plate above the coil armature winding and a curvilinear encoder scale is curved to be co-axis with the curvilinear U-channel permanent magnet track formed by the permanent magnet plates. Driven by a set of miniaturized power electronics devices closely looped with a positioning feedback encoder, the angular position and velocity of the pivoted payload is programmable and precisely controlled.

  8. Uranium arc fission reactor for space propulsion

    Science.gov (United States)

    Watanabe, Yoichi; Maya, Isaac; Vitali, Juan; Appelbaum, Jacob; Schneider, Richard T.

    1991-01-01

    Combining the proven technology of solid core reactors with uranium arc confinement and non-equilibrium ionization by fission fragments can lead to an attractive propulsion system which has a higher specific impulse than a solid core propulsion system and higher thrust than an electric propulsion systems. A preliminary study indicates that a system with 300 MW of fission power can achieve a gas exhaust velocity of 18,000 m/sec and a thrust of 10,000 Newtons utilizing a magnetohydrodynamic generator and accelerator. An experimental program is underway to examine the major mass and energy transfer issues.

  9. Plasma Arc Surface Hardening Robot Technology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In national economy and national defense, a lot of ma chine components become worthless early because of wear and tear and corrode. It leads to huge loss of resource and material. Surface hardening of the steel cou ld form a hard, wearable, corrode-resisting layer on the surface to enhance the mechanical property of the machine component. From 1980s, there is a new method of surface hardening that is heating with plasma arc. It overcomes the shortage of old methods and is adopted in automotive product ...

  10. The ATLAS ARC backend to HPC

    CERN Document Server

    Haug, Sigve; The ATLAS collaboration; Sciacca, Francesco Giovanni; Weber, Michele

    2015-01-01

    The current distributed computing resources used for simulating and processing collision data collected by the LHC experiments are largely based on dedicated x86 Linux clusters. Access to resources, job control and software provisioning mechanisms are quite different from the common concept of self-contained HPC applications run by particular users on specific HPC systems. We report on the development and the usage of a SSH back-end to the Advanced Resource Connector (ARC) middleware to enable HPC compliant access and on the corresponding software provisioning mechanisms.

  11. The ATLAS ARC backend to HPC

    CERN Document Server

    Haug, Sigve; The ATLAS collaboration; Sciacca, Francesco Giovanni; Weber, Michele

    2015-01-01

    The current distributed computing resources used for simulating and processing collision data collected by the LHC experiments are largely based on dedicated x86 Linux clusters. Access to resources, job control and software provisioning mechanisms are quite different from the common concept of self-contained HPC applications run by particular users on specific HPC systems. We report on the development and the usage of a ssh back-end to the Advanced Resource Connector (ARC) middleware to enable HPC compliant access and on the corresponding software provisioning mechanisms.

  12. Pulmonary siderosis (pneumoconiosis) in an arc welder

    Energy Technology Data Exchange (ETDEWEB)

    Triebel, H.J.; Spielmann, R.P.; Jessel, A.

    1988-02-01

    An arc welder of 32 years of age is presented with a random finding of miliar reticulonodular shadows in the plain film of the thorax. Subjectively and objectively the patient appears healthy. The presence of a pneumoconiosis is confirmed by biopsy. Differential diagnosis had to consider sarcoidosis and pulmonary siderosis in view of the known professional anamnesis. This case report underlines the repeated demand to assess X-ray films of the thoracic organs only if the clinical findings and anamnesis are thoroughly known.

  13. The ATLAS ARC backend to HPC

    Science.gov (United States)

    Haug, S.; Hostettler, M.; Sciacca, F. G.; Weber, M.

    2015-12-01

    The current distributed computing resources used for simulating and processing collision data collected by ATLAS and the other LHC experiments are largely based on dedicated x86 Linux clusters. Access to resources, job control and software provisioning mechanisms are quite different from the common concept of self-contained HPC applications run by particular users on specific HPC systems. We report on the development and the usage in ATLAS of a SSH backend to the Advanced Resource Connector (ARC) middleware to enable HPC compliant access and on the corresponding software provisioning mechanisms.

  14. Modeling Epidemic Network Failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    This paper presents the implementation of a failure propagation model for transport networks when multiple failures occur resulting in an epidemic. We model the Susceptible Infected Disabled (SID) epidemic model and validate it by comparing it to analytical solutions. Furthermore, we evaluate...... the SID model’s behavior and impact on the network performance, as well as the severity of the infection spreading. The simulations are carried out in OPNET Modeler. The model provides an important input to epidemic connection recovery mechanisms, and can due to its flexibility and versatility be used...... to evaluate multiple epidemic scenarios in various network types....

  15. Failure of granular assemblies

    OpenAIRE

    Welker, Philipp

    2011-01-01

    This work investigates granular assemblies subjected to increasing external forces in the quasi-static limit. In this limit, the system’s evolution depends on static properties of the system, but is independent of the particles’ inertia. At the failure, which occurs at a certain value of the external forces, the particles’ motions increase quickly. In this thesis, the properties of granular systems during the weakening process and at the failure are investigated with the Discrete Element Meth...

  16. RESEARCH ON ELECTRIC ARC REDUCTION OF CARBON DIOXIDE,

    Science.gov (United States)

    CARBON DIOXIDE , REDUCTION(CHEMISTRY), ELECTRIC ARCS, CHEMICAL REACTIONS, HEAT OF REACTION, GAS FLOW, OXYGEN, CARBON COMPOUNDS, MONOXIDES, ELECTRODES, LABORATORY EQUIPMENT, HIGH TEMPERATURE, PLASMAS(PHYSICS), ENERGY.

  17. The Detection and Statistics of Giant Arcs Behind CLASH Clusters

    CERN Document Server

    Xu, Bingxiao; Meneghetti, Massimo; Seitz, Stella; Zitrin, Adi; Merten, Julian; Maoz, Dani; Frye, Brenda; Umetsu, Keiichi; Zheng, Wei; Bradley, Larry; Vega, Jesus; Koekemoer, Anton

    2015-01-01

    We developed an algorithm to find and characterize gravitationally lensed galaxies (arcs) to perform a comparison of the observed and simulated arc abundance. Observations are from the Cluster Lensing And Supernova survey with Hubble (CLASH). Simulated CLASH images are created using the MOKA package and also clusters selected from the high resolution, hydrodynamical simulations, MUSIC, over the same mass and redshift range as the CLASH sample. The algorithm' s arc elongation accuracy, completeness and false positive rate are determined and used to compute an estimate of the true arc abundance. We derive a lensing efficiency of $4 \\pm 1$ arcs (with length $\\ge 6"$ and length-to-width ratio $\\ge 7$) per cluster for the X-ray selected CLASH sample, $4 \\pm 1$ arcs per cluster for the MOKA simulated sample and $3 \\pm 1$ arcs per cluster for the MUSIC simulated sample. The observed and simulated arc statistics are in full agreement. We measure the photometric redshifts of all detected arcs and find a median redshif...

  18. 基于ArcGIS的土方量计算

    Institute of Scientific and Technical Information of China (English)

    张金荣

    2016-01-01

    本文阐述了ArcGIS计算土方量的原理、方法及实现步骤,并以某工程为实例,对比了ArcGIS法和南方Cass栅格法的土方量计算结果,说明了ArcGIS在计算土方量方面的优越性,并对ArcGIS土方量计算法的实际应用提出独特的见解.

  19. ArcGIS的演进路径研究

    Institute of Scientific and Technical Information of China (English)

    朱紫焱; 伊雪琴

    2005-01-01

    ESRI公司的ArcGIS系列是一个全面、完善、可伸缩的GIS软件平台,无论是单用户还是多用户,无论是在桌面端、服务器端、互连网还是野外操作,都可以通过ArcGIS构建地理信息系统。分别介绍了ArcGIS 8与ArcGIS 9系列软件的演进路径,从中可以看出 ESRI对自我的不断超越。

  20. Developmental DSP4 effects on cortical Arc expression.

    Science.gov (United States)

    Sanders, Jeff

    2016-04-08

    Activity Regulated Cytoskeleton Associated Protein (Arc) is an immediate early gene that is critical to brain plasticity. In this study, norepinephrine's regulation of Arc expression was examined during different stages of postnatal development. Rats were injected with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride (DSP-4), a selective noradrenergic neurotoxin, during preadolescence (PND 0 or 13), adolescence (PND 23 or 48) or adulthood (PND 60). After each DSP4 treatment, brains were harvested later in development and Arc mRNA levels analyzed with in situ hybridization. Rats lesioned with DSP4 during preadolescence showed no differences in Arc level compared to saline treated controls. In contrast, adolescence was a time of changing Arc mRNA response to DSP4. Rats lesioned during early adolescence showed Arc expression increases, while rats lesioned during late adolescence showed dramatic Arc expression decreases. Decreases in Arc level caused by late adolescent DSP4 were similar to those found in lesioned adults. These findings highlight a qualitatively different regulation of Arc expression by norepinephrine according to developmental stage, and indicate that mature regulation is not intact until late adolescence. These data point to important developmental differences in norepinephrine's regulation of brain plasticity. These differences may underlie contrasting psychotropic responses in children and adolescents compared to adults.

  1. The arc characteristic of ultrasonic assisted TIG welding

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Many applications of ultrasonic-assisted methods were used during metal solidification, but they could not be introduced into weld pool. In this paper, a way of ultrasonic assisted TIG welding is introduced. By directly imposed ultrasonic vibration on welding arc, the vibration interacts with arc plasma and passes to the weld pool. Measurement results show that arc pressure is significantly increased with the ultrasonic vibration and the arc pressure distribution models are changed. Bead-on-plate welding tests on SUS304 confirm that this technology can influence the style of metal melting and increase weld penetration depth.

  2. Community Structure Comparisons of Hydrothermal Vent Microbial Mats Along the Mariana Arc and Back-arc

    Science.gov (United States)

    Hager, K. W.; Fullerton, H.; Moyer, C. L.

    2015-12-01

    Hydrothermal vents along the Mariana Arc and back-arc represent a hotspot of microbial diversity that has not yet been fully recognized. The Mariana Arc and back-arc contain hydrothermal vents with varied vent effluent chemistry and temperature, which translates to diverse community composition. We have focused on iron-rich sites where the dominant primary producers are iron oxidizing bacteria. Because microbes from these environments have proven elusive in culturing efforts, we performed culture independent analysis among different microbial communities found at these hydrothermal vents. Terminal-restriction fragment length polymorphism (T-RFLP) and Illumina sequencing of small subunit ribosomal gene amplicons were used to characterize community members and identify samples for shotgun metagenomics. Used in combination, these methods will better elucidate the composition and characteristics of the bacterial communities at these hydrothermal vent systems. The overarching goal of this study is to evaluate and compare taxonomic and metabolic diversity among different communities of microbial mats. We compared communities collected on a fine scale to analyze the bacterial community based on gross mat morphology, geography, and nearby vent effluent chemistry. Taxa richness and evenness are compared with rarefaction curves to visualize diversity. As well as providing a survey of diversity this study also presents a juxtaposition of three methods in which ribosomal small subunit diversity is compared with T-RFLP, next generation amplicon sequencing, and metagenomic shotgun sequencing.

  3. Perioperative acute renal failure.

    LENUS (Irish Health Repository)

    Mahon, Padraig

    2012-02-03

    PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

  4. Copeptin in Heart Failure

    DEFF Research Database (Denmark)

    Balling, Louise; Gustafsson, Finn

    2016-01-01

    Heart failure (HF) is one of the most common causes of hospitalization and mortality in the modern Western world and an increasing proportion of the population will be affected by HF in the future. Although HF management has improved quality of life and prognosis, mortality remains very high...

  5. Heart failure in COPD

    NARCIS (Netherlands)

    Rutten, Frans Hendrik

    2005-01-01

    The main aim of the thesis was to assess the prevalence of heart failure in patients with a diagnosis of chronic obstructive pulmonary disease (COPD). Furthermore, to explore diagnostic strategies (including natriuretic peptides and cardiovascular magnetic resonance imaging (CMR)) to identify heart

  6. Acute liver failure

    DEFF Research Database (Denmark)

    Bernal, William; Lee, William M; Wendon, Julia;

    2015-01-01

    Over the last three decades acute liver failure (ALF) has been transformed from a rare and poorly understood condition with a near universally fatal outcome, to one with a well characterized phenotype and disease course. Complex critical care protocols are now applied and emergency liver...

  7. Poverty and Aspirations Failure

    NARCIS (Netherlands)

    Dalton, P.S.; Ghosal, S.; Mani, A.

    2011-01-01

    We develop a theoretical framework to study the psychology of poverty and 'aspirations failure'. In our framework, the rich and the poor share the same preferences - and also a behavioral bias in setting aspirations. Greater downside risks imposed by poverty exacerbates the effects of this behaviora

  8. Effects of shielding gas composition on arc profile and molten pool dynamics in gas metal arc welding of steels

    Science.gov (United States)

    Wang, L. L.; Lu, F. G.; Wang, H. P.; Murphy, A. B.; Tang, X. H.

    2014-11-01

    In gas metal arc welding, gases of different compositions are used to produce an arc plasma, which heats and melts the workpiece. They also protect the workpiece from the influence of the air during the welding process. This paper models gas metal arc welding (GMAW) processes using an in-house simulation code. It investigates the effects of the gas composition on the temperature distribution in the arc and on the molten pool dynamics in gas metal arc welding of steels. Pure argon, pure CO2 and different mixtures of argon and CO2 are considered in the study. The model is validated by comparing the calculated weld profiles with physical weld measurements. The numerical calculations reveal that gas composition greatly affects the arc temperature profile, heat transfer to the workpiece, and consequently the weld dimension. As the CO2 content in the shielding gas increases, a more constricted arc plasma with higher energy density is generated as a result of the increased current density in the arc centre and increased Lorentz force. The calculation also shows that the heat transferred from the arc to the workpiece increases with increasing CO2 content, resulting in a wider and deeper weld pool and decreased reinforcement height.

  9. Cathodic ARC surface cleaning prior to brazing

    Energy Technology Data Exchange (ETDEWEB)

    Dave, V. R. (Vivek R.); Hollis, K. J. (Kendall J.); Castro, R. G. (Richard G.); Smith, F. M. (Frank M.); Javernick, D. A. (Daniel A.)

    2002-01-01

    Surface cleanliness is one the critical process variables in vacuum furnace brazing operations. For a large number of metallic components, cleaning is usually accomplished either by water-based alkali cleaning, but may also involve acid etching or solvent cleaning / rinsing. Nickel plating may also be necessary to ensure proper wetting. All of these cleaning or plating technologies have associated waste disposal issues, and this article explores an alternative cleaning process that generates minimal waste. Cathodic arc, or reserve polarity, is well known for welding of materials with tenacious oxide layers such as aluminum alloys. In this work the reverse polarity effect is used to clean austenitic stainless steel substrates prior to brazing with Ag-28%Cu. This cleaning process is compared to acid pickling and is shown to produce similar wetting behavior as measured by dynamic contact angle experiments. Additionally, dynamic contact angle measurements with water drops are conducted to show that cathodic arc cleaning can remove organic contaminants as well. The process does have its limitations however, and alloys with high titanium and aluminum content such as nickel-based superalloys may still require plating to ensure adequate wetting.

  10. PSYCHOSOMATIC "ARC" IN THE PSYCHOTHERAPEUTIC PRACTICE

    Directory of Open Access Journals (Sweden)

    Ivanka Boncheva

    2012-11-01

    Full Text Available The psychoneuroimmunology, the new brain science and the endocrinology today show a lot of results, with which symptoms are better to understand. The psychotherapeutic practice shows the ways to influence them by encoding the levels of bounding between the physical symptom and the psychological condition. The aim of the study was to show the encoding of the psychosomatic arc within a real psychotherapeutic contact. 59 psychotherapeutic cases are followed. 33 of them were with somatoform disorders and 26 with chronic psychosomatic diseases. Every patient has minimum 12 psychotherapeutic sessions. The treatment is provided on the base of the 5 levels model of the positive psychotherapy.We ascertain the following:1. The most significant moment in the arise of such symptomatic is the gained past experience - "vital concepts"; "coping strategies";2. Unlocking moment for the arise of the affection is the fixed emotion - fear, aggression or depression, specific for the particular morbid pictures;3. Showing the connection between symptom and fixed emotion by the technique "positive interpretation", which unlocks the process of changingThis shows that the psychotherapeutic help is possible only if the patient rethink the psychosomatic arc. Showing the connections between the content of the unconscious, the fixed emotion in behavioral models and the symptom gives the impetus to change.

  11. Development of circuit model for arcing on solar panels

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Bhoomi K; Deshpande, S P; Mukherjee, S; Gupta, S B; Ranjan, M; Rane, R; Vaghela, N; Acharya, V [FCIPT, Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); Sudhakar, M; Sankaran, M; Suresh, E P, E-mail: bhoomi@ipr.res.i [ISRO Satellite Centre (ISAC), Bangalore 560017 (India)

    2010-02-01

    The increased requirements of payload capacity of the satellites have resulted in much higher power requirements of the satellites. In order to minimize the energy loss during power transmission due to cable loss, use of high voltage solar panels becomes necessary. When a satellite encounters space plasma it floats negatively with respect to the surrounding space plasma environment. At high voltage, charging and discharging on solar panels causes the power system breakdown. Once a solar panel surface is charged and potential difference between surface insulator and conductor exceeds certain value, electrostatic discharge (ESD) may occur. This ESD may trigger a secondary arc that can destroy the solar panel circuit. ESD is also called as primary or minor arc and secondary is called major arc. The energy of minor arc is supplied by the charge stored in the coverglass of solar array and is a pulse of typically several 100 ns to several 100 {mu}s duration. The damage caused by minor arc is less compared to major arcs, but it is observed that the minor arc is cause of major arc. Therefore it is important to develop an understanding of minor arc and mitigation techniques. In this paper we present a linear circuit analysis for minor arcs on solar panels. To study arcing event, a ground experimental facility to simulate space plasma environment has been developed at Facilitation Centre for Industrial Plasma Technologies (Institute for Plasma Research) in collaboration with Indian Space Research Organization's ISRO Satellite Technology Centre (ISAC). A linear circuit model has been developed to explain the experimental results by representing the coverglass, solar cell interconnect and wiring by an LCR circuit and the primary arc by an equivalent LR circuit. The aim of the circuit analysis is to predict the arc current which flows through the arc plasma. It is established from the model that the current depends on various parameters like potential difference between

  12. Commissioning and first clinical application of mARC treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dzierma, Yvonne; Nuesken, Frank G.; Kremp, Stephanie; Palm, Jan; Licht, Norbert P.; Ruebe, Christian [Universitaetsklinikum des Saarlandes, Klinik fuer Strahlentherapie und Radioonkologie, Homburg, Saarland (Germany)

    2014-11-15

    The modulated arc (mARC) technique has recently been introduced for Siemens ARTISTE linear accelerators. We present the first experiences with the commissioning of the system and first patient treatments. Treatment planning and delivery are presented for the Prowess Panther treatment planning system or, alternatively, an in-house code. Dosimetric verification is performed both by point dose measurements and in 3D dose distribution. Depending on the target volume, one or two arcs can be used to create highly conformal plans. Dosimetric verification of the converted mARC plans with step-and-shoot plans shows deviations below 1 % in absolute point dose; in the 3D dose distribution, over 95 % of the points pass the 3D gamma criteria (3 % deviation in local dose and 3 mm distance to agreement for doses > 20 % of the maximum). Patient specific verification of the mARC dose distribution with the calculations has a similar pass rate. Treatment times range between 2 and 5 min for a single arc. To our knowledge, this is the first report of clinical application of the mARC technique. The mARC offers the possibility to save significant amounts of time, with single-arc treatments of only a few minutes achieving comparable dose distribution to IMRT plans taking up to twice as long. (orig.) [German] Die mARC (modulated arc) Technik wurde vor kurzen fuer Siemens ARTISTE Linearbeschleuniger eingefuehrt. Wir zeigen die ersten Erfahrungen mit der Kommissionierung des Systems sowie die ersten Patientenbestrahlungen. Bestrahlungsplanung und Behandlung werden fuer das Prowess Panther Bestrahlungsplanungssystem oder alternativ in einer in-house-Loesung praesentiert. Die dosimetrische Verifikation wurde sowohl mit Punktmessungen als auch fuer die 3D-Dosisverteilung durchgefuehrt. Je nach Zielvolumen koennen mit einem oder zwei Boegen hochkonformale Plaene erzeugt werden. Die dosimetrische Verifikation konvertierter mARC-Plaene gegen step-and-shoot-Plaene weicht in absoluter Dosis um

  13. Arc Deflection Length Affected by Transverse Rotating Magnetic Field with Lateral Gas

    Science.gov (United States)

    Shiino, Toru; Ishii, Yoko; Yamamoto, Shinji; Iwao, Toru; High Current Energy Laboratory (HiCEL) Team

    2016-10-01

    Gas metal arc welding using shielding gas is often used in the welding industry. However, the arc deflection affected by lateral gas is problem because of inappropriate heat transfer. Shielding gas is used in order to prevent the instability affected by the arc deflection. However, the shielding gas causes turbulence, then blowhole of weld defect occurs because the arc affected by the instability is contaminated by the air. Thus, the magnetic field is applied to the arc in order to stabilize the arc using low amount of shielding gas. The method of applying the transverse rotating magnetic field (RMF) to the arc is one of the methods to prevent the arc instability. The RMF drives the arc because of electromagnetic force. The driven arc is considered to be prevented to arc deflection of lateral gas because the arc is restrained by the magnetic field because of the driven arc. In addition, it is assume the RMF prevented to the arc deflection of lateral gas from the multiple directions. In this paper, the arc deflection length affected by the RMF with lateral gas was elucidated in order to know the effect of the RMF for arc stabilization. Specifically, the arc deflection length affected by the magnetic frequency and the magnetic flux density is measured by high speed video camera. As a result, the arc deflection length decreases with increasing magnetic frequency, and the arc deflection length increases with increasing the magnetic flux density.

  14. Time between failures model and failure analysis of CNC system

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hai-bo; JIA Ya-zhou; ZHOU Guang-wen

    2007-01-01

    To provide basis for the reliability improvement design of CNC system, the failure data of a type of CNC system in one year are collected under field conditions in workshops. The distribution model parameters of time between failures are estimated by least square method and hypothesis testing is done by d-test method. It is proved that the time between failures of the CNC system follows Weibull distribution and the system has entered into the wear-out failure period. The failure positions and failure causes are analyzed further to indicate the weak subsystems of the CNC system. It can be found that servo unit, electrical system, detecting unit and power supply are principal failure positions and the main failure cause is breakage of components. The corresponding improvement measures are put forward. The paper provides a reference to reliability design and analysis of CNC system for the manufacturer and has great guidance to using and maintaining CNC system for the user.

  15. Ultraviolet radiation emitted by CO(2) arc welding.

    Science.gov (United States)

    Okuno, T; Ojima, J; Saito, H

    2001-10-01

    The arcs associated with arc welding emit high levels of ultraviolet radiation (UVR), and this often causes acute injuries in the workplace, particularly photokeratoconjunctivitis. It is important to know the level of UVR emitted by arc welding under various conditions, as this information will help in evaluating potential UVR hazards in welding workplaces and taking protective measures against it. In this study, the ACGIH effective irradiance for UVR was measured experimentally for CO(2) arc welding in order to evaluate its UVR hazards. A welding robot was used in the experiment in order to realize reproducible and consistent welding operations. The effective irradiance at 1 m from the arc was in the range 0.28-7.85 W/m(2) (28-785 microW/cm(2)) under the study conditions. The corresponding permissible exposure time per day is only 4-100 s, suggesting that UVR from CO(2) arc welding is actually hazardous for the eye and skin. It was found that the effective irradiance is inversely proportional to the square of the distance from the arc, is strongly dependent on the direction of emission from the arc with a maximum at 50-60 degrees from the plate surface, and tends to increase with welding current.

  16. 29 CFR 1910.254 - Arc welding and cutting.

    Science.gov (United States)

    2010-07-01

    ... given to safety ground connections of portable machines. (4) Leaks. There shall be no leaks of cooling... Requirements for Electric Arc-Welding Apparatus, NEMA EW-1-1962, National Electrical Manufacturers Association or the Safety Standard for Transformer-Type Arc-Welding Machines, ANSI C33.2—1956,...

  17. 29 CFR 1926.351 - Arc welding and cutting.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Arc welding and cutting. 1926.351 Section 1926.351 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Welding and Cutting § 1926.351 Arc welding and cutting. (a) Manual electrode holders. (1) Only manual electrode holders which are specifically...

  18. 29 CFR 1915.56 - Arc welding and cutting.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Arc welding and cutting. 1915.56 Section 1915.56 Labor... (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Welding, Cutting and Heating § 1915.56 Arc welding and cutting. The provisions of this section shall apply to ship...

  19. Using the ARCS Model To Design Multimedia College Engineering Courses.

    Science.gov (United States)

    Shellnut, Bonnie; Savage, Timothy; Knowlton, Allie

    This paper describes how a Wayne State University (Michigan) multimedia design team is applying Keller's ARCS (Attention, Relevance, Confidence, and Satisfaction) Model of Motivational Design to the entire process of design, development, and evaluation of multimedia courseware. The ARCS Model has been applied to the prototype module and is being…

  20. [Fatal electric arc accidents due to high voltage].

    Science.gov (United States)

    Strauch, Hansjürg; Wirth, Ingo

    2004-01-01

    The frequency of electric arc accidents has been successfully reduced owing to preventive measures taken by the professional association. However, the risk of accidents has continued to exist in private setting. Three fatal electric arc accidents caused by high voltage are reported with reference to the autopsy findings.

  1. Anode heat transfer in a constricted tube arc.

    Science.gov (United States)

    Lukens, L. A.; Incropera, F. P.

    1971-01-01

    The complex energy exchange mechanisms occurring on the most severely heated component of an arc constrictor, the anode, have been investigated. Measurements performed to determine the anode heat flux for a cascade, atmospheric argon arc of the Maecker type are described. The results are used to check the validity of an existing anode heat transfer model.

  2. Arc generation from sputtering plasma-dielectric inclusion interactions

    CERN Document Server

    Wickersham, C E J; Fan, J S

    2002-01-01

    Arcing during sputter deposition and etching is a significant cause of particle defect generation during device fabrication. In this article we report on the effect of aluminum oxide inclusion size, shape, and orientation on the propensity for arcing during sputtering of aluminum targets. The size, shape, and orientation of a dielectric inclusion plays a major role in determining the propensity for arcing and macroparticle emission. In previous studies we found that there is a critical inclusion size required for arcing to occur. In this article we used high-speed videos, electric arc detection, and measurements of particle defect density on wafers to study the effect of Al sub 2 O sub 3 inclusion size, shape, and orientation on arc rate, intensity, and silicon wafer particle defect density. We found that the cross-sectional area of the inclusion exposed to the sputtering plasma is the critical parameter that determines the arc rate and rate of macroparticle emission. Analysis of the arc rate, particle defect...

  3. Applying the ARCS Motivation Model in Technological and Vocational Education

    Science.gov (United States)

    Liao, Hung-Chang; Wang, Ya-huei

    2008-01-01

    This paper describes the incorporation of Keller's ARCS (Attention, Relevance, Confidence, and Satisfaction) motivation model into traditional classroom instruction-learning process. Viewing that technological and vocational students have low confidence and motivation in learning, the authors applied the ARCS motivation model not only in the…

  4. Liquid Metal Oscillation and Arc Behaviour during Welding

    NARCIS (Netherlands)

    Yudodibroto, B.Y.B.

    2010-01-01

    The purpose of this research is to obtain insight into the oscillation behaviour of the liquid metal and the arc behaviour during GMA welding. Observations of the weld pool and the arc were undertaken by visual means using a high-speed video and by analysis of the voltage. To deal with the complex p

  5. Variable-Polarity Plasma Arc Welding Of Alloy 2219

    Science.gov (United States)

    Walsh, Daniel W.; Nunes, Arthur C., Jr.

    1989-01-01

    Report presents results of study of variable-polarity plasma arc (VPPA) welding of aluminum alloy 2219. Consists of two parts: Examination of effects of microsegregation and transient weld stress on macrosegregation in weld pool and, electrical characterization of straight- and reverse-polarity portions of arc cycle.

  6. The occurrence and damage of unipolar arcing on fuzzy tungsten

    NARCIS (Netherlands)

    Aussems, D. U. B.; Nishijima, D.; Brandt, C.; van der Meiden, H. J.; M. Vilémová,; J. Matějíček,; De Temmerman, G.; Doerner, R. P.; N.J. Lopes Cardozo,

    2015-01-01

    Abstract This research investigated whether unipolar arcing in the divertor of fusion reactors is a potential cause for enhanced wear of the divertor. It was found that 1 μm of nano-fuzz growth is sufficient to initiate arcing, mainly depending on the sheath potential drop and electron dens

  7. What makes an electric welding arc perform its required function

    Energy Technology Data Exchange (ETDEWEB)

    Correy, T.B.

    1982-09-01

    The physics of direct current and alternating current welding arcs, the heat transfer of direct current welding arcs, the characteristics of dc welding and ac welding power supplies and recommendations for the procurement and maintenance of precision power supplies are discussed. (LCL)

  8. Gas Tungsten Arc Welding. Welding Module 6. Instructor's Guide.

    Science.gov (United States)

    Missouri Univ., Columbia. Instructional Materials Lab.

    This guide is intended to assist vocational educators in teaching a three-unit module in gas tungsten arc welding. The module has been designed to be totally integrated with Missouri's Vocational Instruction Management System. The basic principles involved in gas tungsten arc welding, supplies, and applications are covered. The materials included…

  9. Water-vortex-stabilized electric arc: III. Radial energy transport, determination of water-vapour-boundary and arc performance

    Energy Technology Data Exchange (ETDEWEB)

    Jenista, Jiri [Institute of Plasma Physics ASCR, Za Slovankou 3, PO Box 17, Prague 8, 182 21 (Czech Republic)

    2003-12-07

    This paper is concerned with numerical modelling of an electric arc stabilized by a water vortex. The two-dimensional axisymmetric model presented includes the arc discharge area between the cathode and the outlet nozzle of the water plasma torch. The aims of the numerical simulations are: (1) to assess the influence of radial position of the water-vapour-boundary in the discharge chamber on arc performance and overall radial energy transport within the arc; (2) to determine the most probable mass flow rates and radii of the water-vapour-boundary in the discharge chamber for a prescribed current; (3) to demonstrate arc performance for two radiation models involved; and (4) to estimate validity of local thermodynamic equilibrium (LTE) conditions within the arc column. The rate of evaporation of water is calculated from the conduction and radiation heat fluxes at the water vapour surface for the specified mass flow rate. The behaviour of such an arc has been studied for a range of current 300-600 A. It is shown that changes of bulk magnitudes of different terms in the momentum and energy equations within the arc column as a function of arc radius enable us to reveal transitions of temperature and velocity fields from one steady state to a qualitatively different one. The best fit between experiment and numerical simulation for all currents exists for the mean arc radius {approx} 3.3 mm. Deviations from LTE within the arc column are estimated with the criteria for kinetic equilibrium and spatial temperature gradients.

  10. OBSTETRIC RENAL FAILURE

    Directory of Open Access Journals (Sweden)

    Rajeshwari

    2015-11-01

    Full Text Available Renal failure in obstetrics is rare but important complication, associated with significant mortality and long term morbidity.1,2 It includes acute renal failure due to obstetrical complications or due to deterioration of existing renal disease. AIMS AND OBJECTIVES: To evaluate the etiology and outcome of renal failure in obstetric patients. METHODS: We prospectively analyzed 30 pregnant and puerperal women with acute renal failure or pre-existing renal disease developing renal failure during pregnancy between November 2007 to sep-2009. Patients who presented/developed ARF during the hospital stay were included in this study. RESULTS: Among 30 patients, mean age was 23 years and 33 years age group. 12 cases (40% patients were primigravidae and 9(30% patients were multigravidae and 9 cases (30% presented in post-partum period. Eighteen cases (60% with ARF were seen in third trimester, followed by in postpartum period 9 cases (30%. Most common contributing factors to ARF were Pre-eclampsia, eclampsia and HELLP syndrome 60%, sepsis 56.6%, post abortal ARF 10%. DIC 40%. Haemorrhage as the aetiology for ARF was present 46%, APH in 20% and PPH in 26.6%. The type of ARF was renal in (63% and prerenal (36%; Oliguric seen in 10 patients (33% and high mortality (30%. Among the 20 pregnant patients with ARF, The average period of gestation was 33±2 weeks (30 -36 weeks, 5 cases (25% presented with intrauterine fetal demise and 18 cases (66% had preterm vaginal delivery and 2 cases (10% had induced abortion. And the average birth weight was 2±0.5 kg (1.5 kg. Eight cases (26% required dialysis. 80% of patients recovered completely of renal functions. 63% patients recovered without renal replacement therapy whereas 17% required dialysis. the maternal mortality was 20%, the main reason for mortality was septic shock and multi organ dysfunction (66%. CONCLUSION: ARF related pregnancy was seen commonly in the primigravidae and in the third trimester, the most

  11. A method to determine arc position in ICRF systems

    Energy Technology Data Exchange (ETDEWEB)

    D’Inca, R., E-mail: rodolphe.dinca@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Garching (Germany); Polozhiy, K.; Eckert, B.; Siegel, G. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Garching (Germany); Noterdaeme, J.-M. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Garching (Germany); EESA Department, Gent University (Belgium)

    2013-10-15

    Highlights: ► We show that the voltage noise characteristic of an arc in an ICRF system is due to the propagation and reflections of an electromagnetic pulse emitted by this arc. ► A simplified RF model of an arc in a testbed representative of an ICRF system is developed to see the effect of its location on the voltage noise it emits. ► The model is compared with the results on the testbed for arcs occurring at two locations: one can be determined precisely, the other with a decreased accuracy. -- Abstract: The study of arcs on ICRF systems has mainly focused on the development of fast detectors to detect a breakdown, independently from its position, before they can damage the components [1]. However, the ability to localize an arc is also an important factor: arcs can be the sign of a defect and if they occur at the same location, they give a good indication of the position of this defect without having to use intrusive diagnostics like optical fibers. We present here a method to find the position of arcs based on the analysis of their high-frequency noise. Arcs are indeed fast transient which excite frequencies in the MHz range. The SHAD system reacts on the integral value of this noise signal to detect the development of arcs. But a further investigation of this signal shows detailed features like splittings and chirpings of the frequency peaks which give more information on the source of the breakdown: at its birth, the arc emits a short electromagnetic pulse of several nanoseconds that propagates inside the ICRF system; this pulse is reflected by components like the antenna, the stub tuners or the generators back to the arc thereby changing its boundary conditions. This resonance between the arc and the ICRF system can be measured and the time of propagation of the pulse gives useful data on the position of the breakdown. We have carried out tests on the Manipulator eXPeriment (a testbed to artificially create arcs in a representative ICRF system) and

  12. Single Arc VMAT of H&N cancer

    DEFF Research Database (Denmark)

    Bertelsen, Anders

      Background: A few radiation treatment planning systems are currently able to plan volumetric modulated arc therapy (VMAT). The VMAT algorithm in Pinnacle3 TM is called SmartArc. The capability of SmartArc to generate complex treatment plans for the head and neck (H&N) region was tested...... - when corrected for offset in output - satisfied a gamma criterion of 3mm and 3% of 2Gy compared to 99.7±0.1% for IMRT.   Conclusion: SmartArc generated single arc VMAT plans with improved target coverage and sparing of OARs compared to IMRT. The conformity was increased by VMAT compared to IMRT...... reducing high dose volumes in normal tissues. The VMAT plans used fewer MUs compared to the IMRT plans and reduced the treatment time by approximately 40% compared to IMRT. Both IMRT and VMAT radiation treatment plans delivered on an Elekta Synergy accelerator produced clinically acceptable geometric dose...

  13. Investigation of optimal control system for arc spraying

    Institute of Scientific and Technical Information of China (English)

    Li Heqi; Li Chunxu

    2005-01-01

    Arc-voltage feedback PID ( Proportional plus Integral plus Differential) controller and arc-current feedback PID controller are designed with an algorithm of discrete PID. In order to realize parameters optimization and adaptation of the arc-spraying process and to reduce blindness in selecting process parameters, a serial communication interface between PC and MCU (Micro Control Unit) is designed so that on-line modification of the PID control parameters is implemented. A genetic algorithm is adopted to optimize PID control parameters. Meanwhile, the error between the actual value and the setting value of spraying current is selected as the judgment criterion to determine the adaptability for the algorithm. The best optimal population of PID control parameters can be obtained, so that the optimal controlling in arc-spraying process is realized and an excellent coating of arc-spraying is obtained.

  14. Theory of Parabolic Arcs in Interstellar Scintillation Spectra

    CERN Document Server

    Cordes, J M; Stinebring, D R; Coles, W A; Cordes, James M.; Rickett, Barney J.; Stinebring, Daniel R.; Coles, William A.

    2004-01-01

    Our theory relates the secondary spectrum, the 2D power spectrum of the radio dynamic spectrum, to the scattered pulsar image in a thin scattering screen geometry. Recently discovered parabolic arcs in secondary spectra are generic features for media that scatter radiation at angles much larger than the rms scattering angle. Each point in the secondary spectrum maps particular values of differential arrival-time delay and fringe rate (or differential Doppler frequency) between pairs of components in the scattered image. Arcs correspond to a parabolic relation between these quantities through their common dependence on the angle of arrival of scattered components. Arcs appear even without consideration of the dispersive nature of the plasma. Arcs are more prominent in media with negligible inner scale and with shallow wavenumber spectra, such as the Kolmogorov spectrum, and when the scattered image is elongated along the velocity direction. The arc phenomenon can be used, therefore, to constrain the inner scal...

  15. Mathematical Modeling of Metal Active Gas (MAG) Arc Welding

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the present paper, a numerical model for MAG (metal active gas) arc welding of thin plate has been developed. In MAG arc welding, the electrode wire is melted and supplied into the molten pool intermittently. Accordingly, it is assumed on the modeling that the thermal energy enters the base-plates through two following mechanisms, i.e., direct heating from arc plasma and “indirect” heating from the deposited metal. In the second part of the paper, MAG arc welding process is numerically analyzed by using the model, and the calculated weld bead dimension and surface profile have been compared with the experimental MAG welds on steel plate. As the result, it is made clear that the model is capable of predicting the bead profile of thin-plate MAG arc welding , including weld bead with undercutting.

  16. Assistant Anode in a Cathodic Arc Plasma Source

    Institute of Scientific and Technical Information of China (English)

    张涛; Paul K. Chu; 张荟星; Ian G. Brown

    2001-01-01

    The performance and characteristics of a cathodic arc plasma source, consisting of a titanium cathode, an anode with and without a tungsten mesh, and a coil producing a focusing magnetic field between the anode and cathode,are investigated. The high transparency and large area of the mesh allow a high plasma flux to penetrate the anode from the cathodic arc. The mesh helps to decrease the arc resistance and the ignition voltage of the cathodic arc in the focusing magnetic field, and to increase the life of the source, which means that the source makes the cathodic arc easily and greatly stabilized during the operation when a focusing magnetic field exists in the source.

  17. Single Arc VMAT of H&N patients

    DEFF Research Database (Denmark)

    Bertelsen, Anders; Hansen, Christian Rønn; Johansen, Jørgen;

      Background: A few planning systems are currently able to plan volumetric modulated arc therapy (VMAT) which can be delivered on Elekta and Varian accelerators. Pinnacles version of a VMAT algorithm is called SmartArc. SmartArcs capability to modulate complicated treatment plans is to be tested...... recommendations. The patients were re-planned with VMAT by use of the SmartArc algorithm in Pinnacle (research version). The collapsed cone dose engine was used for final dose calculation. One constraint for the re-planning study was to use only one single arc to create deliverable plans. The objectives were...... to achieve similar or better target coverage and sparring of organs at risk (OAR) as achieved in the IMRT plan. The VMAT plans were compared to the original IMRT plans by evaluation of 1) treatment time, 2) monitor units (MU) 3) DVH for targets and OAR and 4) the dose measured with a Delta4 phantom from...

  18. Single Arc VMAT of H&N cancer

    DEFF Research Database (Denmark)

    Bertelsen, Anders

      Background: A few radiation treatment planning systems are currently able to plan volumetric modulated arc therapy (VMAT). The VMAT algorithm in Pinnacle3 TM is called SmartArc. The capability of SmartArc to generate complex treatment plans for the head and neck (H&N) region was tested...... Target Volumes (PTV). The patients were re-planned with VMAT using the SmartArc algorithm in Pinnacle3TM 8.9c (research version). A constraint for the re-planning was to use only one single arc to create deliverable plans. The objectives were to achieve identical or better target coverage and sparing...... of the organs at risk (OAR) using VMAT compared to IMRT. The comparison was made by evaluating of 1) dose-volume histograms (DVHs) of PTVs and OARs, 2) monitor units, 3) treatment time, and 4) treatment accuracy as delivered on Elekta Synergy accelerators   Results: Preliminary results based on 11 patients...

  19. Single Arc VMAT of H&N patients

    DEFF Research Database (Denmark)

    Bertelsen, Anders; Hansen, Christian Rønn; Johansen, Jørgen;

    2009-01-01

      Background: A few planning systems are currently able to plan volumetric modulated arc therapy (VMAT) which can be delivered on Elekta and Varian accelerators. Pinnacles version of a VMAT algorithm is called SmartArc. SmartArcs capability to modulate complicated treatment plans is to be tested...... recommendations. The patients were re-planned with VMAT by use of the SmartArc algorithm in Pinnacle (research version). The collapsed cone dose engine was used for final dose calculation. One constraint for the re-planning study was to use only one single arc to create deliverable plans. The objectives were...... to achieve similar or better target coverage and sparring of organs at risk (OAR) as achieved in the IMRT plan. The VMAT plans were compared to the original IMRT plans by evaluation of 1) treatment time, 2) monitor units (MU) 3) DVH for targets and OAR and 4) the dose measured with a Delta4 phantom from...

  20. Improvement on Diamond Nucleation Treated by Pulsed Arc Discharge Plasma

    Institute of Scientific and Technical Information of China (English)

    马志斌; 万军; 汪建华; 张文文

    2004-01-01

    A technique of improvement on diamond nucleation based on pulsed arc discharge plasma at atmospheric pressure was developed. The pulsed arc discharge was induced respectively by nitrogen, argon and methanol gas. After the arc plasma pretreatment, a nucleation density higher than 1010 cm-2 may be obtained subsequently in chemical vapor deposition (CVD) on a mirror-polished silicon substrate without any other mechanical treatment. The effects of the arc discharge plasma on the diamond nucleation were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR) and Raman spectroscopy. The enhancement of nucleation is postulated to be a result of the formation of carbonlike phase materials or nitrogenation on the substrate surface without surface defect produced by arc discharge.

  1. Effect of Energetic Electrons on Quiet Auroral Arc Formation

    Science.gov (United States)

    Hasegawa, Hiroki; Ohno, Nobuaki; Sato, Tetsuya

    2010-11-01

    The theory of feedback instability between the magnetosphere and ionosphere is believed as one of the candidate to explain the formation of quiet auroral arc. Then, some magneto-hydro- dynamics simulations showed the arc formation by this macroscopic instability, while the effect of auroral energetic electrons on the arc formation was neglected or given as a macroscopic parameter in these simulations. On the other hand, because of the recent development of particle simulations, auroral energetic electrons are thought to be produced by the super ion-acoustic double layer that should be created by microscopic instability. To make close investigation of auroral arc formation, it is necessary to consider the interaction with microscopic instability. In this paper, we numerically study the effect of energetic electrons on quiet auroral arc formation by means of the Macro-Micro Interlocked simulation.

  2. Investigation on the stepping arc stud welding process

    Institute of Scientific and Technical Information of China (English)

    Chi Qiang; Zhang Jianxun; Fu Jifei; Zhang Youquan

    2005-01-01

    Through the investigation on traditional arc stud welding process, a new welding gun and its control system were developed in this paper. The stepping arc stud welding gun was mainly made by a stepping motor as actuating unit and a screw-driven device as moving unit. A control system with a MCS-51 single-chip microcomputer as main control component was used to realize the new stud welding procedure. This new welding process with stepping stud welding gun is named as stepping arc stud welding. In the new welding process, the stud action can be looked as constituted by some micro steps. The setting and adjusting of the stepping arc welding gun behavior parameters are accomplished independently. It is indicated from the results of process tests and bending test that the stepping arc stud welding process is practicable.

  3. New product failure

    DEFF Research Database (Denmark)

    Dijksterhuis, Garmt Bernard

    2016-01-01

    When new consumer products are developed and later launched, 50 to 75 percent of them are removed from the market far short of meeting their projected financial targets. In short: they fail. We conclude that this failure is due to institutionalized insufficiencies in the use of the sciences...... surroundings. This often is in great contrast with their high levels of technological science, paralleled by their respective research budgets. In this paper we present five problem areas that may contribute to this mismatch, contributing to needlessly high numbers of product failures. We have termed...... these factors: (1) 'pillars' (too many different functions addressing different aspects of the consumers and of product development), (2) 'higher management focus' (not geared towards understanding consumer behaviour), (3) 'popular science books' (out-dated research directives resulting from a hierarchical...

  4. Generalized Block Failure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2015-01-01

    Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... yield lines around the block leads to simple interaction formulas similar to other interaction formulas in the codes.......Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...

  5. [Nutrition and liver failure].

    Science.gov (United States)

    Plauth, M

    2013-06-01

    In the critically ill liver patient, nutrition support is not very different from that given for other illnesses. In hyperacute liver failure, nutrition support is of less importance than in the other subtypes of acute liver failure that take a more protracted course. Nasoenteral tube feeding using a polymeric standard formula should be the first-line approach, while parenteral nutrition giving glucose, fat, amino acids, vitamins, and trace elements is initiated when enteral nutrition is insufficient or impracticable. In chronic liver disease, notably cirrhosis, there is frequently protein malnutrition indicating a poor prognosis and requiring immediate initiation of nutrition support. Enteral nutrition ensuring an adequate provision of energy and protein should be preferred. Particular care should be taken to avoid refeeding syndrome and to treat vitamin and trace element deficiency.

  6. The ArcD1 and ArcD2 arginine/ornithine exchangers encoded in the arginine deiminase (ADI) pathway gene cluster of Lactococcus lactis

    NARCIS (Netherlands)

    Noens, Elke E E; Kaczmarek, Michał B; Żygo, Monika; Lolkema, Juke S

    2015-01-01

    The arginine deiminase pathway (ADI) gene cluster in Lactococcus lactis contains two copies of a gene encoding an L-arginine/L-ornithine exchanger, the arcD1 and arcD2 genes. The physiological function of ArcD1 and ArcD2 was studied by deleting the two genes. Deletion of arcD1 resulted in loss of th

  7. LHC Magnet test failure

    CERN Multimedia

    2007-01-01

    "On Tueday, March 22, a Fermilab-built quadrupole magnet, one of an "inner triplet" of three focusing magnets, failed a high-pressure test at Point 5 in the tunnel of the LHC accelerator at CERN. Since Tuesday, teams at CERN and Fermilab have worked closely together to address the problem and have identified the cause of the failure. Now they are at work on a solution.:" (1 page)

  8. Predicting Small Bank Failure

    OpenAIRE

    Heyliger, Wilton E.; Don P. Holdren

    1991-01-01

    There are many studies of bank performance and bank failure in the literature. Most of these studies used banking ratios as variables in their models without giving consideration to their appropriateness, nor was much consideration given to the stability of those ratios through time and across asset size. Many studies also failed to recognize that bank structure may differ by asset size. This study evaluates a large number of banking variables in order to identify stable ratios. These ratios ...

  9. DOM database based on ArcSDE

    Science.gov (United States)

    Wu, Wen-bo; Bing, Yuan-yuan

    2009-10-01

    To solve the problems of massive, multi-source provincial image data management, storage, retrieval, and so on, ArcSDE spatial data engine architecture and data model are used to establish a provincial DOM database by combining Oracle 10g database management system. The establishment of the database of remote sensing images successfully solve some specific problems of the block image data processing, image pyramid building, data compression, etc. Meanwhile, the grid index structure and the method of retrieval based on contents are adopted. It has been proved by practice that the disposal of the images by level and block can store the images in a fast and efficient way. The combination of grid index accelerates the retrieval of the images, and the DOM data can be effectively organized, security storage and effectively used.

  10. Modeling of AC arc inside wet snow

    Energy Technology Data Exchange (ETDEWEB)

    Hemmatjou, H.

    2006-07-01

    Overhead transmission lines cover long distances over a broad range of topographic relief, climates, and environments. As such, the high voltage equipment is subject to pollution, wet snow and atmospheric icing. Each of these factors have been the source of power outages recorded on power transmission lines. Electric arcs can develop on outdoor insulators until they cause a total flashover. This study involved the modeling of flashover in snow-covered insulators to better understand how electric discharges initiate inside snow and how they develop into flashover. The main objective of this thesis was to develop a mathematical model to predict the flashover voltage of snow-covered insulator surfaces and to ultimately design adequate insulators for cold regions. The results obtained through mathematical modeling were in good agreement with those obtained in experiments.

  11. Hydrothermal treatment of electric arc furnace dust.

    Science.gov (United States)

    Yu, Bing-Sheng; Wang, Yuh-Ruey; Chang, Tien-Chin

    2011-06-15

    In this study, ZnO crystals were fabricated from electric arc furnace dust (EAFD) after alkaline leaching, purification and hydrothermal treatment. The effects of temperature, duration, pH, and solid/liquid ratio on ZnO crystal morphology and size were investigated. Results show a high reaction temperature capable of accelerating the dissolution of ZnO precursor, expediting the growth of 1D ZnO, and increasing the L/D ratio in the temperature range of 100-200°C. ZnO crystals with high purity can also be obtained, using the one-step hydrothermal treatment with a baffle that depends on the different solubility of zincite and franklinite in the hydrothermal conditions.

  12. The modelling of an SF6 arc in a supersonic nozzle: II. Current zero behaviour of the nozzle arc

    Science.gov (United States)

    Zhang, Q.; Liu, J.; Yan, J. D.; Fang, M. T. C.

    2016-08-01

    The present work (part II) forms the second part of an investigation into the behaviour of SF6 nozzle arc. It is concerned with the aerodynamic and electrical behaviour of a transient nozzle arc under a current ramp specified by a rate of current decay (di/dt) before current zero and a voltage ramp (dV/dt) after current zero. The five flow models used in part I [1] for cold gas flow and DC nozzle arcs have been applied to study the transient arc at three stagnation pressures (P 0) and two values of di/dt for the current ramp, representing a wide range of arcing conditions. An analysis of the physical mechanisms encompassed in each flow model is given with an emphasis on the adequacy of a particular model in describing the rapidly varying arc around current zero. The critical rate of rise of recovery voltage (RRRV) is found computationally and compared with test results of Benenson et al [2]. For transient nozzle arcs, the RRRV is proportional to the square of P 0, rather than to the square root of P 0 for DC nozzle arcs. The physical mechanisms responsible for the strong dependence of RRRV on P 0 have been investigated. The relative merits of the flow models employed are discussed.

  13. Gas Tungsten Arc Welding and Plasma Arc Cutting. Teacher Edition [and] Student Edition [and] Student Workbook. Second Edition.

    Science.gov (United States)

    Harper, Eddie; Knapp, John

    This packet of instructional materials for a gas tungsten arc welding (GTAW) and plasma arc cutting course is comprised of a teacher edition, student edition, and student workbook. The teacher edition consists of introductory pages and teacher pages. Introductory pages include training and competency profile, state duty/task crosswalk,…

  14. 3D cartography of the Alpine Arc

    Science.gov (United States)

    Vouillamoz, N.; Sue, C.; Champagnac, J. D.; Calcagno, P.

    2012-04-01

    We present a 3D cartography of the alpine arc, a highly non-cylindrical mountain belt, built using the 3D GeoModeller of the BRGM (French geological survey). The model allows to handle the large-scale 3D structure of seventeen major crustal units of the belt (from the lower crust to the sedimentary cover nappes), and two main discontinuities (the Insubric line and the Crustal Penninic Front). It provides a unique document to better understand their structural relationships and to produce new sections. The study area comprises the western alpine arc, from the Jura to the Northwest, up to the Bergell granite intrusion and the Lepontine Dome to the East, and is limited to the South by the Ligurian basin. The model is limited vertically 10 km above sea level at the top, and the moho interface at the bottom. We discarded the structural relationships between the Alps sensus stricto and the surrounding geodynamic systems such as the Rhine graben or the connection with the Apennines. The 3D-model is based on the global integration of various data such as the DEM of the Alps, the moho isobaths, the simplified geological and tectonic maps of the belt, the crustal cross-sections ECORS-CROP and NFP-20, and complementary cross-sections specifically built to precise local complexities. The database has first been integrated in a GIS-project to prepare their implementation in the GeoModeller, by homogenizing the different spatial referencing systems. The global model is finally interpolated from all these data, using the potential field method. The final document is a new tri-dimentional cartography that would be used as input for further alpine studies.

  15. Simulation of the Effects of Several Factors on Arc Plasma Behavior in Low Voltage Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Taking into account the properties of the arc plasma and the electromagnetic, heat and radiative phenomena, commercial computational fluid dynamics software PHOENICS has been adapted and modified to develop the three-dimensional magneto-hydrodynamic (MHD)model of arc in a low voltage circuit breaker. The effects of the arc ignition location, venting size and gassing material on arc behavior have been investigated. The analysis of the results show that the arc velocity accelerates with the increase in the distance between arc ignition location and of the venting size, and the existence of the gassing material is beneficial to improving the arc voltage and reducing the arc temperature.

  16. Analysis of low energy arc discharge characteristics based on dynamic V-A characteristics model

    Institute of Scientific and Technical Information of China (English)

    JING Li-nan; WANG Li-gong

    2006-01-01

    Low energy arc discharge characteristics was analyzed based on dynamic V-A characteristics model. It draws conclusions that discharge time relates to the source voltage and the product of inductance and stable current, discharge time will increase when the source voltage increases; current reduce rate is in inverse proportion to the value of inductance; arc resistance when the arc occurs is the ratio of minimum arcing voltage to stable current. It also gains the expressions of arc resistance and arc power, arc resistance and arc power both increase as the source voltage increases and decrease as the value of inductance increases. Conclusions above mentioned are helpful to design intrinsically safe circuits.

  17. Peat slope failure in Ireland

    OpenAIRE

    Boylan, Noel; Jennings, Paul; Long, Michael

    2008-01-01

    Recent peat failures in Ireland in the autumn of 2003 at Pollatomish, County Mayo and Derrybrien, County Galway have focused attention on such events. However, peat failures are not a recent phenomenon with possible evidence of peat failures in Ireland having been identified as far back as the Early Bronze Age. This paper summarises the issues surrounding peat failures in Ireland that would be of interest to an engineer\\engineering geologist assessing this geohazard. The distri...

  18. ArcGeomorphometry: A toolbox for geomorphometric characterisation of DEMs in the ArcGIS environment

    Science.gov (United States)

    Rigol-Sanchez, Juan P.; Stuart, Neil; Pulido-Bosch, Antonio

    2015-12-01

    A software tool is described for the extraction of geomorphometric land surface variables and features from Digital Elevation Models (DEMs). The ArcGeomorphometry Toolbox consists of a series of Python/Numpy processing functions, presented through an easy-to-use graphical menu for the widely used ArcGIS package. Although many GIS provide some operations for analysing DEMs, the methods are often only partially implemented and can be difficult to find and used effectively. Since the results of automated characterisation of landscapes from DEMs are influenced by the extent being considered, the resolution of the source DEM and the size of the kernel (analysis window) used for processing, we have developed a tool to allow GIS users to flexibly apply several multi-scale analysis methods to parameterise and classify a DEM into discrete land surface units. Users can control the threshold values for land surface classifications. The size of the processing kernel can be used to identify land surface features across a range of landscape scales. The pattern of land surface units from each attempt at classification is displayed immediately and can then be processed in the GIS alongside additional data that can assist with a visual assessment and comparison of a series of results. The functionality of the ArcGeomorphometry toolbox is described using an example DEM.

  19. The Application Developers Framework for .NET in ArcGIS%ArcGIS中的.NET应用开发框架

    Institute of Scientific and Technical Information of China (English)

    李建中

    2008-01-01

    本文介绍了ArcGIS中的.NET应用开发框架(.NET Application Developer Framework:.NET ADF或者ADF),这个框架的目的是为ArcGIS服务器开发Web应用程序,为Web用户提供网络上的地理信息系统服务.这个框架大体可分成3个部分:用于Microsoft Visual Studio .NET集成开发环境的模板;用于.NET ASP的ArcGIS Web控件;便捷类.ADF部署在ArcGIS服务器上,调用服务器上的ArcObjects完成有关GIS的Web服务.

  20. CRITERIA FOR ROCK ENGINEERING FAILURE

    Institute of Scientific and Technical Information of China (English)

    ZHUDeren; ZHANGYuzhuo

    1995-01-01

    A great number of underground rock projects are maintained in the rock mass which is subject to rock damage and failure development. In many cases, the rock. engineering is still under normal working conditions even though rock is already fails to some extent. This paper introduces two different concepts: rock failure and rock engineering failure. Rock failure is defined as a mechanical state under which an applicable characteristic is changed or lost.However, the rock engineering failure is an engineering state under which an applicable function is changed or lost. The failure of surrounding rocks is the major reason of rock engineering failure. The criterion of rock engineering failure depends on the limit of applicable functions. The rock engineering failure state possesses a corresponding point in rock failure state. In this paper, a description of rock engineering failure criterion is given by simply using a mechanical equation or expression. It is expected that the study of rock engineering failure criterion will be an optimal approach that combines research of rock mechanics with rock engineering problems.

  1. Novel therapies in heart failure

    NARCIS (Netherlands)

    Liu, Licette Cécile Yang

    2016-01-01

    Heart failure is a clinical condition that is characterized by the inability of the heart to meet the oxygen requirements of peripheral tissues and organs, despite normal filling pressures. Despite recent developments in the treatment of heart failure, the prognosis of heart failure patients remains

  2. Numerical and experimental study of transferred arcs in argon

    Energy Technology Data Exchange (ETDEWEB)

    Bini, R [Department of Mechanical Engineering, Politecnico di Milano, Via Bonardi 9, 20133 Milan (Italy); Monno, M [Department of Mechanical Engineering, Politecnico di Milano, Via Bonardi 9, 20133 Milan (Italy); Boulos, M I [Centre de Recherche en Energie, Plasma et Electrochimie (CREPE), Department de Genie Chimique Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, J1K1R2 (Canada)

    2006-08-07

    The bidimensional model of the electric arc is enhanced with the plasma-electrodes interaction to predict the properties and the energy distribution of an argon arc operating with current intensities between 100 and 200 A and electrode gaps of 10 and 20 mm. An adaptive numerical insulation is applied to the cathode, to properly simulate its thermionic emission mechanism and overcome the dependence on empirical distributions of the current density at its tip. The numerical results are quantitatively compared with the data obtained from calorimetric and spectroscopical measurements, performed on a device which generates a transferred arc between a water cooled copper anode and a thoriated tungsten cathode enclosed in a stainless steel chamber. The calculation of the heat fluxes towards the electrodes permits to determine the amount of power delivered to each component of the arc system (the anode, the cathode assembly and the chamber) and to evaluate the overall efficiency of the process for different configurations. The agreement between theory and data, over the range of parameters investigated, is sensible both in the temperature profiles and in the energy distributions. In such configurations, the conduction from the hot gas is the most relevant term in the overall heat transferred to the anode, but it is the electron transfer which rules the heat transfer in the arc attachment zone. The arc attachment radius is also dependent on the process parameters and increases with the arc current (from approximately 5 mm at 100 A to 7 mm at 200 A) and the arc length. However the maximum heat flux reached on the axis decreases increasing the gap between the electrodes, although more power is delivered to the anode due to the radial spreading of the plasma. A 10 mm 200 A argon arc releases to the anode about 2.6 kW, which corresponds to 75% of the total arc power available. If the arc is extended to 20 mm the power transferred rises by nearly 350 W, but the overall

  3. Carboniferous rifted arcs leading to an archipelago of multiple arcs in the Beishan-Tianshan orogenic collages (NW China)

    Science.gov (United States)

    Tian, Zhonghua; Xiao, Wenjiao; Windley, Brian F.; Zhang, Ji'en; Zhang, Zhiyong; Song, Dongfang

    2016-12-01

    The Beishan and East Tianshan Orogenic Collages in the southernmost Central Asian Orogenic Belt (CAOB) record the final stages of evolution of the Paleo-Asian Ocean. These collages and their constituent arcs have an important significance for resolving current controversies regarding their tectonic setting and age, consequent accretionary history of the southern CAOB, and the closure time of the Paleo-Asian Ocean. In this paper, we present our work on the southern Mazongshan arc and the northern Hongyanjing Basin in the Beishan Orogenic Collage (BOC), and our comparison with the Bogda arc and associated basins in the East Tianshan Orogenic Collage. Field relationships indicate that the Pochengshan fault defines the boundary between the arc and basin in the BOC. Volcanic rocks including basalts and rhyolites in the Mazongshan arc have bimodal calc-alkaline characteristics, an enrichment in large ion lithophile elements such as Rb, Ba, and Pb and depletion in high field-strength elements (e.g., Nb and Ta), which were probably developed in a subduction-related tectonic setting. We suggest that these bimodal calc-alkaline volcanic rocks formed in rifted arcs instead of post-orogenic rifts with mantle plume inputs. By making detailed geochemical comparisons between the Mazongshan arc and the Bogda arc to the west, we further propose that they are similar and both formed in arc rifts, and helped generate a Carboniferous archipelago of multiple arcs in the southern Paleo-Asian Ocean. These data and ideas enable us to postulate a new model for the tectonic evolution of the southern CAOB.

  4. Gas tungsten arc welding of ZrB2–SiC based ultra high temperature ceramic composites

    OpenAIRE

    R.V. Krishnarao; G. Madhusudhan Reddy

    2015-01-01

    The difficulty in fabricating the large size or complex shape limits the application of ZrB2–SiC composites. Joining them by fusion welding without or with preheating, controlled cooling under protective gas shield leads to thermal shock failure or porosity at the weld interface. In the present work, a filler material of (ZrB2–SiC–B4C–YAG) composite with oxidation resistance and thermal shock resistance was produced in the form of welding wire. Using the filler, gas tungsten arc welding (GTAW...

  5. Lidar arc scan uncertainty reduction through scanning geometry optimization

    Directory of Open Access Journals (Sweden)

    H. Wang

    2015-10-01

    Full Text Available Doppler lidars are frequently operated in a mode referred to as arc scans, wherein the lidar beam scans across a sector with a fixed elevation angle and the resulting measurements are used to derive an estimate of the n minute horizontal mean wind velocity (speed and direction. Previous studies have shown that the uncertainty in the measured wind speed originates from turbulent wind fluctuations and depends on the scan geometry (the arc span and the arc orientation. This paper is designed to provide guidance on optimal scan geometries for two key applications in the wind energy industry: wind turbine power performance analysis and annual energy production. We present a quantitative analysis of the retrieved wind speed uncertainty derived using a theoretical model with the assumption of isotropic and frozen turbulence, and observations from three sites that are onshore with flat terrain, onshore with complex terrain and offshore, respectively. The results from both the theoretical model and observations show that the uncertainty is scaled with the turbulence intensity such that the relative standard error on the 10 min mean wind speed is about 30 % of the turbulence intensity. The uncertainty in both retrieved wind speeds and derived wind energy production estimates can be reduced by aligning lidar beams with the dominant wind direction, increasing the arc span and lowering the number of beams per arc scan. Large arc spans should be used at sites with high turbulence intensity and/or large wind direction variation when arc scans are used for wind resource assessment.

  6. The occurrence and damage of unipolar arcing on fuzzy tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Aussems, D.U.B., E-mail: d.aussems@differ.nl [FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Nieuwegein, NL-3430 BE (Netherlands); Nishijima, D.; Brandt, C. [Center for Energy Research, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0417 (United States); Meiden, H.J. van der [FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Nieuwegein, NL-3430 BE (Netherlands); Vilémová, M.; Matějíček, J. [Institute of Plasma Physics, Association EURATOM-IPP, 182 00 Prague 8 (Czech Republic); De Temmerman, G. [FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Nieuwegein, NL-3430 BE (Netherlands); Doerner, R.P. [Center for Energy Research, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0417 (United States); Lopes Cardozo, N.J. [Science and Technology of Nuclear Fusion, Eindhoven University of Technology, Den Dolech 2, Eindhoven (Netherlands)

    2015-08-15

    This research investigated whether unipolar arcing in the divertor of fusion reactors is a potential cause for enhanced wear of the divertor. It was found that 1 μm of nano-fuzz growth is sufficient to initiate arcing, mainly depending on the sheath potential drop and electron density. The average mass loss rate induced by the arc was determined from mass loss measurements and found to be consistent with the value estimated from the arc current. The average arc track erosion depth was estimated by using the measured mass loss and damaged surface area and was found to be one tenth of the fuzzy layer thickness. Due to melting of the fuzzy structures the actual depth is larger and some arc tracks occasionally appeared to even reach the bulk beyond the fuzzy layer. The conclusion of this study is therefore that arcing in the divertor of future tokamaks (e.g. ITER) potentially is an important cause for surface damage and plasma pollution.

  7. Interruption Phenomenon in Intermediate-Frequency Vacuum Arc

    Science.gov (United States)

    Jiang, Yuan; Wu, Jianwen

    2016-03-01

    In the condition of the 3 mm gap, experiments for 360 Hz intermediate-frequency vacuum arc are carried out in interrupters with the diameters being 41 mm and with the contact materials being CuCr50 and Cu-W-WC alloy respectively. The results indicate that the contacts material is closely related to the breaking capacity of the vacuum interrupters and characteristics of an intermediate-frequency vacuum arc. For contacts with the same diameter, the breaking capacity of CuCr50 is better than that of Cu-W-WC. When the current fails to be interrupted, the arcs overflow the gap and present irregular performances in the first half wave. Consequently a voltage spike appears. More macroscopic metal droplets can be seen in the arc column between CuCr50 contacts because of the lower melting point. It is observed that the droplet emission is much more severe during arc reignition than that in the first half wave. It is much more conspicuous that the high frequency arc voltage noises appear in Cu-W-WC contacts when the vacuum arcs reignite, for higher temperature and stronger electronic emission ability of Cu-W-WC contacts. supported by National Natural Science Foundation of China (No. 51377007), Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20131102130006), and Fundamental Research Funds for the Central Universities of China

  8. Petrology and tectonics of Phanerozoic continent formation: From island arcs to accretion and continental arc magmatism

    Science.gov (United States)

    Lee, C.-T.A.; Morton, D.M.; Kistler, R.W.; Baird, A.K.

    2007-01-01

    Mesozoic continental arcs in the North American Cordillera were examined here to establish a baseline model for Phanerozoic continent formation. We combine new trace-element data on lower crustal xenoliths from the Mesozoic Sierra Nevada Batholith with an extensive grid-based geochemical map of the Peninsular Ranges Batholith, the southern equivalent of the Sierras. Collectively, these observations give a three-dimensional view of the crust, which permits the petrogenesis and tectonics of Phanerozoic crust formation to be linked in space and time. Subduction of the Farallon plate beneath North America during the Triassic to early Cretaceous was characterized by trench retreat and slab rollback because old and cold oceanic lithosphere was being subducted. This generated an extensional subduction zone, which created fringing island arcs just off the Paleozoic continental margin. However, as the age of the Farallon plate at the time of subduction decreased, the extensional environment waned, allowing the fringing island arc to accrete onto the continental margin. With continued subduction, a continental arc was born and a progressively more compressional environment developed as the age of subducting slab continued to young. Refinement into a felsic crust occurred after accretion, that is, during the continental arc stage, wherein a thickened crustal and lithospheric column permitted a longer differentiation column. New basaltic arc magmas underplate and intrude the accreted terrane, suture, and former continental margin. Interaction of these basaltic magmas with pre-existing crust and lithospheric mantle created garnet pyroxenitic mafic cumulates by fractional crystallization at depth as well as gabbroic and garnet pyroxenitic restites at shallower levels by melting of pre-existing lower crust. The complementary felsic plutons formed by these deep-seated differentiation processes rose into the upper crust, stitching together the accreted terrane, suture and former

  9. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  10. Renal Failure in Pregnancy.

    Science.gov (United States)

    Balofsky, Ari; Fedarau, Maksim

    2016-01-01

    Renal failure during pregnancy affects both mother and fetus, and may be related to preexisting disease or develop secondary to diseases of pregnancy. Causes include hypovolemia, sepsis, shock, preeclampsia, thrombotic microangiopathies, and renal obstruction. Treatment focuses on supportive measures, while pharmacologic treatment is viewed as second-line therapy, and is more useful in mitigating harmful effects than treating the underlying cause. When supportive measures and pharmacotherapy prove inadequate, dialysis may be required, with the goal being to prolong pregnancy until delivery is feasible. Outcomes and recommendations depend primarily on the underlying cause.

  11. Energy Balance in DC Arc Plasma Melting Furnace

    Institute of Scientific and Technical Information of China (English)

    ZHAO Peng; MENG Yuedong; YU Xinyao; CHEN Longwei; JIANG Yiman; NI Guohua; CHEN Mingzhou

    2009-01-01

    In order to treat hazardous municipal solid waste incinerator's (MSWI) fly ash, a new DC arc plasma furnace was developed. Taking an arc of 100 V/1000 A DC as an example,the heat transfer characteristics of the DC arc plasma, ablation of electrodes, heat properties of the fly ash during melting, heat transfer characteristics of the flue gas, and heat loss of the furnace were analyzed based on the energy conservation law, so as to achieve the total heat information and energy balance during plasma processing, and to provide a theoretical basis for an optimized design of the structure and to improve energy efficiency.

  12. SHORTEST PATH ARC LENGTH NETWORK USING TRIANGULAR INTUITIONISTIC FUZZY NUMBER

    Directory of Open Access Journals (Sweden)

    A.D.CHANDRASEKARAN

    2016-04-01

    Full Text Available In this paper, an intuitionistic fuzzy shortest path is presented to find the optimal path in a network which a fuzzy number, instead of a positive integer is assigned to each arc length. The algorithm is based on the idea that firstly from all the shortest paths from source to destination, an arc with shortest length is computed and then the Euclidean distance is computed for all the paths with the arc of minimum distance. Finally an illustrative numerical example is given to express the proposed work.

  13. Plasma backflow phenomenon in high-current vacuum arc

    Energy Technology Data Exchange (ETDEWEB)

    Wang Lijun [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Jia Shenli [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Zhang Ling [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Shi Zongqian [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Yang Dingge [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Gentils, Francois [Schneider Electric SAS, 37 quai Paul-Louis Merlin, 38050 Grenoble Cedex 9 (France); Jusselin, BenoIt [Schneider Electric SAS, 37 quai Paul-Louis Merlin, 38050 Grenoble Cedex 9 (France)

    2007-10-07

    Based on the two-temperature magnetohydrodynamic model, a high-current vacuum arc (HCVA) in vacuum interrupters is simulated and analysed. The phenomenon of plasma backflow in arc column is found, which is ultimately ascribed to the strong magnetic pinch effect of HCVA. Due to plasma backflow, the maximal value of ion density at the cathode side is not located at the centre of the cathode side, but at the paraxial region of the cathode side, that is to say, ion density appears to sag at the centre of the cathode side (arc column seems to be divided into two parts). The sag of light intensity is also found by experiments.

  14. Determination of secondary collimator shape in electron arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pla, M.; Podgorsak, E.B.; Pla, C.; Freeman, C.R. (Montreal General Hospital, PQ (Canada))

    1993-07-01

    The characteristic angle-[beta] concept in electron arc therapy of non-cylindrical target volume is applied in determining the required shape of the arced electron field to yield a uniform dose distribution inside the target volume. The empirical relationships derived for this purpose from the angle-[beta] concept are valid for all field widths and thus offer an improvement over the currently known empirical relationships which were derived as small-field-width approximations. The validity of the determination of field shapes in electron arc therapy with the empirical relationships based on the angle-[beta] concept is confirmed by measurements of dose distributions in a spherical phantom. (Author).

  15. Dependence of Arc Plasma Dispersion Capability on its Temperature

    Institute of Scientific and Technical Information of China (English)

    CHEN Yun-Yun; SONG Yang; HE An-Zhi; LI Zhen-Hua

    2008-01-01

    @@ The relationship between the dispersion capability and the temperature of argon arc plasma at Iatm is deduced in view of the plasma's refractive index equation.The results indicate that argon arc plasma has a normal dispersion and its dispersion capability is nonlinear to the plasma's temperature in a wide range of temperature and wavelength region.According to the results of numerical calculation, the preferred optical methods are believed to be suitable for the diagnosis of argon arc plasma in different temperature regions.

  16. Composition Gradient Hard Coatings by Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; LIN Guo-qiang; WANG Fu-gang

    2004-01-01

    Arc Ion Plating can be used to synthesize multi-component composition gradient hard coatings by adjusting arc currents of metal targets. The present work aims at a comprehensive description of such a technique. The examples of TiAl multi-layer alloy coatings and (Ti, M) N composition-gradient films were taken (M representing Zr, Nb etc.) for the purpose of explaining the working process and evaluating practical effects. The results show that this technique has the advantages of easy manipulation, rapid deposition, and wide composition range.Key Words: Arc Ion plating, hard coating, composition gradient coatings

  17. Phenomenology of surface arcs on spacecraft dielectric materials

    Science.gov (United States)

    Balmain, K. G.; Gossland, M.; Reeves, R. D.; Kuller, W. G.

    1982-01-01

    For electron beam incidence on large specimens of Kapton thermal blanket material, surface arc discharges are shown to cause damage consisting of punchthrough holes which act as focal points for other types of damage, including subsurface tunnels, blowout holes and surface breakup. Under electron bombardment, dielectric sheet specimens separated by a gap are shown to discharge simultaneously. Teflon specimens which have been brushed or rubbed are shown to exhibit directional guidance of discharge arcs, and this phenomenon has been used to generate straight arcs whose velocities have been measured optically.

  18. Wear-resistance and anti-scuffing of multi-arc ion plating molybdenum films

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-dou; XU Bin-shi; LIU Jia-jun; ZHUANG Da-ming

    2004-01-01

    The multi-arc ion plating technology was employed to prepare the molybdenum films with thickness of 3 μm on the AISI 1045 steel. The wear and scuffing tests were carried out on the ball-on-disc tester. AFM and SEM equipped with EDS were adopted to observe and analyze the morphologies and element compositions of surface,cross-section and worn scar of the Mo film. The phase structure was studied by XRD and the bonding strength between Mo film and substrate was measured by scratching tester. The tribological experiments show that the Mo film possesses a good wear-resistance and an excellent anti-scuffing property. The failure mechanism of Mo film under extreme condition is flaking off.

  19. Arc reattachment driven by a turbulent boundary layer: implications for the sweeping of lightning arcs along aircraft

    Science.gov (United States)

    Guerra-Garcia, C.; Nguyen, N. C.; Peraire, J.; Martinez-Sanchez, M.

    2016-09-01

    A lightning channel attached to an aircraft in flight will be swept along the aircraft’s surface in response to the relative velocity between the arc’s root (attached to a moving electrode) and the bulk of the arc, which is stationary with respect to the air. During this process, the reattachment of the arc to new locations often occurs. The detailed description of this swept stroke is still at an early stage of research, and it entails the interaction between an electrical arc and the flow boundary layer. In this paper we examine the implications of the structure of the boundary layer for the arc sweeping and reattachment process by considering different velocity profiles, both for laminar and turbulent flow, as well as a high fidelity description, using large eddy simulation, of transitional flow over an airfoil. It is found that the local velocity fluctuations in a turbulent flow may be important contributors to the reattachment of the arc, through a combination of an increased potential drop along the arc and local approaches of the arc to the surface. Specific flow features, such as the presence of a laminar recirculation bubble, can also contribute to the possibility of reattachment.

  20. Scaling of structural failure

    Energy Technology Data Exchange (ETDEWEB)

    Bazant, Z.P. [Northwestern Univ., Evanston, IL (United States); Chen, Er-Ping [Sandia National Lab., Albuquerque, NM (United States)

    1997-01-01

    This article attempts to review the progress achieved in the understanding of scaling and size effect in the failure of structures. Particular emphasis is placed on quasibrittle materials for which the size effect is complicated. Attention is focused on three main types of size effects, namely the statistical size effect due to randomness of strength, the energy release size effect, and the possible size effect due to fractality of fracture or microcracks. Definitive conclusions on the applicability of these theories are drawn. Subsequently, the article discusses the application of the known size effect law for the measurement of material fracture properties, and the modeling of the size effect by the cohesive crack model, nonlocal finite element models and discrete element models. Extensions to compression failure and to the rate-dependent material behavior are also outlined. The damage constitutive law needed for describing a microcracked material in the fracture process zone is discussed. Various applications to quasibrittle materials, including concrete, sea ice, fiber composites, rocks and ceramics are presented.

  1. Heart Failure Readmission Reduction.

    Science.gov (United States)

    Drozda, Joseph P; Smith, Donna A; Freiman, Paul C; Pursley, Janet; VanSlette, Jeffrey A; Smith, Timothy R

    Little is known regarding effectiveness of readmission reduction programs over time. The Heart Failure Management Program (HFMP) of St. John's Physician Group Practice (PGP) Demonstration provided an opportunity to assess outcomes over an extended period. Data from an electronic health record, an inpatient database, a disease registry, and the Social Security Death Master File were analyzed for patients admitted with heart failure (HF) for 5 years before (Period 1) and 5 years after (Period 2) inception of PGP. HF admissions decreased (Period 1, 58.3/month; Period 2, 52.4/month, P = .007). Thirty-day all-cause readmission rate dropped from Period 1 (annual average 18.8% [668/3545]) to year 1 of Period 2 (16.9% [136/804], P = .04) and remained stable thereafter (annual average 16.8% [589/3503]). Thirty-day mortality rate was flat throughout. HFMP was associated with decreased readmissions, primarily related to outpatient case management, while mortality remained stable.

  2. Transient Response of Arc Temperature and Iron Vapor Concentration Affected by Current Frequency with Iron Vapor in Pulsed Arc

    Science.gov (United States)

    Tanaka, Tatsuro; Maeda, Yoshifumi; Yamamoto, Shinji; Iwao, Toru

    2016-10-01

    TIG arc welding is chemically a joining technology with melting the metallic material and it can be high quality. However, this welding should not be used in high current to prevent cathode melting. Thus, the heat transfer is poor. Therefore, the deep penetration cannot be obtained and the weld defect sometimes occurs. The pulsed arc welding has been used for the improvement of this defect. The pulsed arc welding can control the heat flux to anode. The convention and driving force in the weld pool are caused by the arc. Therefore, it is important to grasp the distribution of arc temperature. The metal vapor generate from the anode in welding. In addition, the pulsed current increased or decreased periodically. Therefore, the arc is affected by such as a current value and current frequency, the current rate of increment and the metal vapor. In this paper, the transient response of arc temperature and the iron vapor concentration affected by the current frequency with iron vapor in pulsed arc was elucidated by the EMTF (ElectroMagnetic Thermal Fluid) simulation. As a result, the arc temperature and the iron vapor were transient response as the current frequency increase. Thus, the temperature and the electrical conductivity decreased. Therefore, the electrical field increased in order to maintain the current continuity. The current density and electromagnetic force increased at the axial center. In addition, the electronic flow component of the heat flux increased at the axial center because the current density increased. However, the heat conduction component of the heat flux decreased.

  3. Predicting deliverability of volumetric-modulated arc therapy (VMAT) plans using aperture complexity analysis.

    Science.gov (United States)

    Younge, Kelly C; Roberts, Don; Janes, Lindsay A; Anderson, Carlos; Moran, Jean M; Matuszak, Martha M

    2016-07-08

    The purpose of this study was to evaluate the ability of an aperture complexity metric for volumetric-modulated arc therapy (VMAT) plans to predict plan delivery accuracy. We developed a complexity analysis tool as a plug-in script to Varian's Eclipse treatment planning system. This script reports the modulation of plans, arcs, and individual control points for VMAT plans using a previously developed complexity metric. The calculated complexities are compared to that of 649 VMAT plans previously treated at our institution from 2013 to mid-2015. We used the VMAT quality assurance (QA) results from the 649 treated plans, plus 62 plans that failed pretreatment QA, to validate the ability of the complexity metric to predict plan deliverability. We used a receiver operating characteristic (ROC) analysis to determine an appropriate complexity threshold value above which a plan should be considered for reoptimization before it moves further through our planning workflow. The average complexity metric for the 649 treated plans analyzed with the script was 0.132 mm-1 with a standard deviation of 0.036 mm-1. We found that when using a threshold complexity value of 0.180 mm-1, the true positive rate for correctly identifying plans that failed QA was 44%, and the false-positive rate was 7%. Used clinically with this threshold, the script can identify overly modulated plans and thus prevent a significant portion of QA failures. Reducing VMAT plan complexity has a number of important clinical benefits, including improving plan deliverability and reducing treatment time. Use of the complexity metric during both the planning and QA processes can reduce the number of QA failures and improve the quality of VMAT plans used for treatment.

  4. Insomnia Self-Management in Heart Failure

    Science.gov (United States)

    2016-12-07

    Cardiac Failure; Heart Failure; Congestive Heart Failure; Heart Failure, Congestive; Sleep Initiation and Maintenance Disorders; Chronic Insomnia; Disorders of Initiating and Maintaining Sleep; Fatigue; Pain; Depressive Symptoms; Sleep Disorders; Anxiety

  5. Submarine Arc Volcanism in the Southern Mariana Arc: Results of Recent ROV studies

    Science.gov (United States)

    Nichols, A. R.; Tamura, Y.; Stern, R. J.; Embley, R. W.; Hein, J. R.; Jordan, E.; Ribeiro, J. M.; Sica, N.; Kohut, E. J.; Whattam, S. A.; Hirahara, Y.; Senda, R.; Nunokawa, A.

    2009-12-01

    The submarine Diamante cross-arc volcanoes (~16°N) and the Sarigan-Zealandia Bank Multi-Volcano Complex (SZBMVC; ~16°45’N), north and south, respectively, of Anatahan Island in the southern Mariana Arc, were studied during several dives in June 2009 using the ROV Hyper-Dolphin, cruise NT09-08 (R/V Natsushima); neither has been studied in detail before. The data collected provide a new perspective on how the subduction factory operates to complement previous studies on other cross-arc volcanic chains in the Izu-Bonin-Mariana Arc. The Diamante complex consists of three major edifices, two cones (West and Central Diamante) and a more complex caldera-like edifice at the volcanic front (East Diamante). West and Central Diamante are basaltic volcanoes but East Diamante has a more complex history. Our studies indicate initial construction of a basaltic volcano. Magmatic evolution led to a violent caldera-forming and quieter dome-building events. Post-caldera quiescence allowed a carbonate platform to grow, now preserved on the eastern caldera wall. Felsic magma or hot rock provides a heat source for an active hydrothermal field associated with felsic domes in the caldera, which NOAA investigators discovered in 2004. A new type of hydrothermal deposit was discovered in the hydrothermal field, consisting of large sulfide-sulfate mounds topped by bulbous constructions of low-temperature Fe and Mn oxides. Vents on the mounds were observed to emit shimmering water. The SZBMVC consists of six closely spaced edifices whose loci are aligned along two parallel trends, one along the volcanic front (Zealandia Bank, Sarigan and South Sarigan), and one about 15 km west towards the rear-arc (Northwest Zealandia, West Zealandia and West Sarigan). Zealandia Bank dives revealed that, as with East Diamante, initial activity was basaltic and became more evolved with time. The western half of Zealandia Bank is dominated by felsic lavas centered on a small (~2 km diameter) caldera and

  6. Continental crust generated in oceanic arcs

    Science.gov (United States)

    Gazel, Esteban; Hayes, Jorden L.; Hoernle, Kaj; Kelemen, Peter; Everson, Erik; Holbrook, W. Steven; Hauff, Folkmar; van den Bogaard, Paul; Vance, Eric A.; Chu, Shuyu; Calvert, Andrew J.; Carr, Michael J.; Yogodzinski, Gene M.

    2015-04-01

    Thin oceanic crust is formed by decompression melting of the upper mantle at mid-ocean ridges, but the origin of the thick and buoyant continental crust is enigmatic. Juvenile continental crust may form from magmas erupted above intra-oceanic subduction zones, where oceanic lithosphere subducts beneath other oceanic lithosphere. However, it is unclear why the subduction of dominantly basaltic oceanic crust would result in the formation of andesitic continental crust at the surface. Here we use geochemical and geophysical data to reconstruct the evolution of the Central American land bridge, which formed above an intra-oceanic subduction system over the past 70 Myr. We find that the geochemical signature of erupted lavas evolved from basaltic to andesitic about 10 Myr ago--coincident with the onset of subduction of more oceanic crust that originally formed above the Galápagos mantle plume. We also find that seismic P-waves travel through the crust at velocities intermediate between those typically observed for oceanic and continental crust. We develop a continentality index to quantitatively correlate geochemical composition with the average P-wave velocity of arc crust globally. We conclude that although the formation and evolution of continents may involve many processes, melting enriched oceanic crust within a subduction zone--a process probably more common in the Archaean--can produce juvenile continental crust.

  7. Robotic Variable Polarity Plasma Arc (VPPA) Welding

    Science.gov (United States)

    Jaffery, Waris S.

    1993-01-01

    The need for automated plasma welding was identified in the early stages of the Space Station Freedom Program (SSFP) because it requires approximately 1.3 miles of welding for assembly. As a result of the Variable Polarity Plasma Arc Welding (VPPAW) process's ability to make virtually defect-free welds in aluminum, it was chosen to fulfill the welding needs. Space Station Freedom will be constructed of 2219 aluminum utilizing the computer controlled VPPAW process. The 'Node Radial Docking Port', with it's saddle shaped weld path, has a constantly changing surface angle over 360 deg of the 282 inch weld. The automated robotic VPPAW process requires eight-axes of motion (six-axes of robot and two-axes of positioner movement). The robot control system is programmed to maintain Torch Center Point (TCP) orientation perpendicular to the part while the part positioner is tilted and rotated to maintain the vertical up orientation as required by the VPPAW process. The combined speed of the robot and the positioner are integrated to maintain a constant speed between the part and the torch. A laser-based vision sensor system has also been integrated to track the seam and map the surface of the profile during welding.

  8. Magmatic control along a strike-slip volcanic arc: The central Aeolian arc (Italy)

    KAUST Repository

    Ruch, Joel

    2016-01-23

    The regional stress field in volcanic areas may be overprinted by that produced by magmatic activity, promoting volcanism and faulting. In particular, in strike-slip settings, the definition of the relationships between the regional stress field and magmatic activity remains elusive. To better understand these relationships, we collected stratigraphic, volcanic and structural field data along the strike-slip Central Aeolian arc (Italy): here the islands of Lipari and Vulcano separate the extensional portion of the arc (to the east) from the contractional one (to the west). We collected >500 measurements of faults, extension fractures and dikes at 40 sites. Most structures are NNE-SSW to NNW-SSE oriented, eastward dipping, and show almost pure dip-slip motion; consistent with an E-W extension direction, with minor dextral and sinistral shear. Our data highlight six eruptive periods during the last 55 ka, which allow considering both islands as a single magmatic system, in which tectonic and magmatic activity steadily migrated eastward and currently focus on a 10 km long x 2 km wide active segment. Faulting appears to mostly occur in temporal and spatial relation with magmatic events, supporting that most of the observable deformation derives from transient magmatic activity (shorter-term, days to months), rather than from steady longer-term regional tectonics (102-104 years). More in general, the Central Aeolian case shows how magmatic activity may affect the structure and evolution of volcanic arcs, overprinting any strike-slip motion with magma-induced extension at the surface.

  9. Magmatic control along a strike-slip volcanic arc: The central Aeolian arc (Italy)

    Science.gov (United States)

    Ruch, J.; Vezzoli, L.; De Rosa, R.; Di Lorenzo, R.; Acocella, V.

    2016-02-01

    The regional stress field in volcanic areas may be overprinted by that produced by magmatic activity, promoting volcanism and faulting. In particular, in strike-slip settings, the definition of the relationships between the regional stress field and magmatic activity remains elusive. To better understand these relationships, we collected stratigraphic, volcanic, and structural field data along the strike-slip central Aeolian arc (Italy): here the islands of Lipari and Vulcano separate the extensional portion of the arc (to the east) from the contractional one (to the west). We collected >500 measurements of faults, extension fractures, and dikes at 40 sites. Most structures are NNE-SSW to NNW-SSE oriented, eastward dipping, and show almost pure dip-slip motion, consistent with an E-W extension direction, with minor dextral and sinistral shear. Our data highlight six eruptive periods during the last 55 ka, which allow considering both islands as a single magmatic system, in which tectonic and magmatic activities steadily migrated eastward and currently focus on a 10 km long × 2 km wide active segment. Faulting appears to mostly occur in temporal and spatial relation with magmatic events, supporting that most of the observable deformation derives from transient magmatic activity (shorter term, days to months), rather than from steady longer-term regional tectonics (102-104 years). More in general, the central Aeolian case shows how magmatic activity may affect the structure and evolution of volcanic arcs, overprinting any strike-slip motion with magma-induced extension at the surface.

  10. Continent-arc collision in the Banda Arc imaged by ambient noise tomography

    Science.gov (United States)

    Porritt, Robert W.; Miller, Meghan S.; O'Driscoll, Leland J.; Harris, Cooper W.; Roosmawati, Nova; Teofilo da Costa, Luis

    2016-09-01

    The tectonic configuration of the Banda region in southeast Asia captures the spatial transition from subduction of Indian Ocean lithosphere to subduction and collision of the Australian continental lithosphere beneath the Banda Arc. An ongoing broadband seismic deployment funded by NSF is aimed at better understanding the mantle and lithospheric structure in the region and the relationship of the arc-continent collision to orogenesis. Here, we present results from ambient noise tomography in the region utilizing this temporary deployment of 30 broadband instruments and 39 permanent stations in Indonesia, Timor Leste, and Australia. We measure dispersion curves for over 21,000 inter-station paths resulting in good recovery of the velocity structure of the crust and upper mantle beneath the Savu Sea, Timor Leste, and the Nusa Tenggara Timur (NTT) region of Indonesia. The resulting three dimensional model indicates up to ∼25% variation in shear velocity throughout the plate boundary region; first-order velocity anomalies are associated with the subducting oceanic lithosphere, subducted Australian continental lithosphere, obducted oceanic sediments forming the core of the island of Timor, and high velocity anomalies in the Savu Sea and Sumba. The structure in Sumba and the Savu Sea is consistent with an uplifting forearc sliver. Beneath the island of Timor, we confirm earlier inferences of pervasive crustal duplexing from surface mapping, and establish a link to underlying structural features in the lowermost crust and uppermost mantle that drive upper crustal shortening. Finally, our images of the volcanic arc under Flores, Wetar, and Alor show high velocity structures of the Banda Terrane, but also a clear low velocity anomaly at the transition between subduction of oceanic and continental lithosphere. Given that the footprint of the Banda Terrane has previously been poorly defined, this model provides important constraints on tectonic reconstructions that

  11. A plasma-arc pyrolysis system for hazardous waste treatment

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ A laboratory system for the treatment of medical and hazardous wastes via AC plasma-arc pyrolysis was recently built up by a research team led by Prof. SHENG Hongzhi at the CAS Institute of Mechanics (IMECH) in Beijing.

  12. British Columbia 3 arc-second Bathymetric Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 3 arc-second British Columbia DEM will be used to support NOAA's tsunami forecast system and for tsunami inundation modeling. This DEM covers the coastal area...

  13. Destruction of PCDD/Fs by gliding arc discharges

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    PCDD/Fs have been become a serious issue because of their lexicological effects and associated adverse health implications. In this study, the gliding arc plasma was tested for treatment of polychlorinated dibenzo-p-dioxins (PCDDs) and pol ychlorinated dibenzofurans (PCDFs), which was synthesized from pentachlorophenol in atmospheric condition at 350℃ with or without the catalysis of CuCh-From the experiment, we found that the destruction efficiency of PCDD/F homologues after gliding was discharge ranged from 25% to 79%. This result demonstrates that gliding arc plasma is an effective technology to decompose PCDDs/Fs in flue gas. A plausible degradation mechanism for PCDD/Fs by gliding arc was discussed. Finally, a multistage reactor structure of gliding arc was proposed to upgrade removal efficiency for PCDD/Fs.

  14. Simple filtered repetitively pulsed vacuum arc plasma source

    Science.gov (United States)

    Chekh, Yu.; Zhirkov, I. S.; Delplancke-Ogletree, M. P.

    2010-02-01

    A very simple design of cathodic filtered vacuum arc plasma source is proposed. The source without filter has only four components and none of them require precise machining. The source operates in a repetitively pulsed regime, and for laboratory experiments it can be used without water cooling. Despite the simple construction, the source provides high ion current at the filter outlet reaching 2.5% of 400 A arc current, revealing stable operation in a wide pressure range from high vacuum to oxygen pressure up to more than 10-2 mbar. There is no need in complicated power supply system for this plasma source, only one power supply can be used to ignite the arc, to provide the current for the arc itself, to generate the magnetic field in the filter, and provide its positive electric biasing without any additional high power resistance.

  15. High Alumina Refractory Bricks for Electric Arc Furnace Roofs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Scope This standard specifies the sort, technical requirement, test method, inspection rules, marking, packing, transportation, storage and quality certification of high alumina refractory bricks for electric arc furnace roofs.

  16. Bermuda 3 arc-second Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 3 arc-second Bermuda DEM will be used to support NOAA's tsunami forecast system and for tsunami inundation modeling. This DEM encompasses the islands of Bermuda...

  17. 24 arc-second Kenai Peninsula Bororugh Alaska Elevation Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 24 arc-second Kenai Peninsula Bororugh Alaska Elevation Grid provides bathymetric data in ASCII raster format of 24 second resolution in geographic coordinates....

  18. ArcHydro global datasets for Hawaii StreamStats

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset consists of a personal geodatabase containing several vector datasets. These datasets may be used with the ArcHydro Tools, developed by ESRI in...

  19. Bermuda 1 arc-second Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1 arc-second Bermuda DEM will be used to support NOAA's tsunami forecast system and for tsunami inundation modeling. This DEM encompasses the islands of Bermuda...

  20. A study on consumable aided tungsten indirect arc welding

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Wang Yuxin; Feng Jicai

    2009-01-01

    A consumable aided tungsten indirect arc welding method has been studied. This method is different from the traditional TIG welding because it introduces an MIG welding torch into the traditional TIG welding system. An indirect arc is generated between the consumable electrode of the MIG welding torch and the tungsten electrode of the TIG welding torch, but not generated between the tungsten electrode of the welding torch and the base metal. Welding current flows from the consumable electrode to the tungsten electrode in the free-burning indirect arc. The consumable aided tungsten indirect arc welding not only rapidly melts the welding wire but also effectively restrains the excessive fusion of the base metal. The welding experiment and the theoretical analysis confirm that this method can obtain a high deposition rate and a low dilution ratio during the welding process.

  1. Numerical Simulation of the TIG Welding Arc Behavior

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Achieving an effective utilization and exploitation of TIG welding arcs require a thorough understanding of the plasmaproperties and its physical processes. Through simultaneous solutions of the set of conservation equations for mass,momentum, energy and current, a mathematical model has been developed to predict the velocity, temperature,and current density distributions in argon welding arcs. The predicted temperature fields in arc regions, and thedistribution of current density and heat flux at the anode agree well with measurements reported in literatures. Thiswork could lay the foundation for developing a comprehensive model of the TIG welding process where a dynamic,two-way coupling between the welding arc and the weld pool surface is properly represented.

  2. STUDY ON MECHANISM OF ARC-EXCITED ULTRASONIC

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A mechanism of excited arc to be an controlled "ultrasonic emission source" is described. An developed electrical source with an certain frequency bandwidth for the purpose of the arc-excited is connected with an conventional welding power supply through coupling the cables for the experiment. Some resonant frequency bands for the arc-excited ultrasonic are discovered in the welding process, and its frequency, amplitude and phase'shift are recorded. This principle demonstrates that arc can be used not only for a thermal source, but also for an ultrasonic emission source, which may be extent to the industrial application in some new ways, such as for automatic welding process control and quality inspection.

  3. Dual arc penning ion source gas flow experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, E.D.; Lord, R.S.; Mallory, M.L.; Antaya, T.A.

    1984-01-01

    Support gas, when added directly to an arc or admitted to an auxiliary chamber of a two-arc chamber ion source, increases the beam intensity for multicharged ions such as /sup 16/O/sup 5 +/. To clarify the mechanism of this intensity increase, gas flow rates from the auxiliary chamber to the main chamber have been measured by using the ORIC cyclotron as a mass spectrometer. The results show that only about three percent of the gas admitted to the auxiliary chamber reaches the main chamber. One can then infer that the improved operation probably results from the stabilizing effect of heating the common cathodes with the auxiliary arc and/or the more favorable distribution of the support gas to the part of the main arc close to the cathodes.

  4. Structure-function analysis of the NB-ARC domain of plant disease resistance proteins

    NARCIS (Netherlands)

    van Ooijen, G.; Mayr, G.; Kasiem, M.M.A.; Albrecht, M.; Cornelissen, B.J.C.; Takken, F.L.W.

    2008-01-01

    Resistance (R) proteins in plants are involved in pathogen recognition and subsequent activation of innate immune responses. Most resistance proteins contain a central nucleotide-binding domain. This so-called NB-ARC domain consists of three subdomains: NB, ARC1, and ARC2. The NB-ARC domain is a fun

  5. Nonequilibrium flow calculations for the hydrogen constricted arc

    Science.gov (United States)

    Scott, R. K.; Incropera, F. P.

    1973-01-01

    A nonequilibrium flow model has been formulated and solved numerically for conditions in an atomic hydrogen cascade arc. Solutions show that although thermal nonequilibrium effects are minor, the departure from chemical equilibrium is significant. Comparisons with results obtained from an equilibrium flow model reveal the deficiencies associated with such a model and parametric calculations reveal the effect of current, pressure, and radius on arc behavior.

  6. The structure and singularities of quotient arc complexes

    DEFF Research Database (Denmark)

    Penner, Robert

    2008-01-01

    A well-known combinatorial fact is that the simplicial complex consisting of disjointly embedded chords in a convex planar polygon is a sphere. For any surface F with non-empty boundary, there is an analogous complex QA(F) consisting of equivalence classes of arcs in F connecting a given finite s...... with a related quotient arc complex in the punctured case with no boundary. Namely, the essential singularities of the natural cellular compactification of Riemann's moduli space can be described....

  7. Research on Resonance Mechanism of Arc-ultrasonic

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@As a transmission medium, welding arc can be modulated to emit ultrasonic energy by exerting high-frequency electric current. The frequency of exciting electric current has notable influence on the signals recorded by the sensors and the metallographic structures of the welds. The resonance phenomenon of arc-ultrasonic has been found in the experiment. Both the resonance mechanism and the distribution of resonance frequency are discussed by the built vibration equation.

  8. A review of vacuum ARC ion source research at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Evans, P.J.; Noorman, J.T.; Watt, G.C. [ANSTO, Menai (Australia)

    1996-08-01

    The authors talk briefly describes the history and current status of vacuum arc ion source research at the Australian Nuclear Science and Technology Organization (ANSTO). In addition, the author makes some mention of the important role of previous Vacuum Arc Ion Source Workshops in fostering the development of this research field internationally. During the period 1986 - 89, a type of plasma centrifuge known as a vacuum arc centrifuge was developed at ANSTO as part of a research project on stable isotope separation. In this device, a high current vacuum arc discharge was used to produce a metal plasma which was subsequently rotated in an axial magnetic field. The high rotational speeds (10{sup 5} - 10{sup 6} rad sec{sup {minus}1}) achievable with this method produce centrifugal separation of ions with different mass:charge ratios such as isotopic species. The first portent of things to come occurred in 1985 when Dr. Ian Brown visited ANSTO`s Lucas Heights Research Laboratories and presented a talk on the metal vapour vacuum arc (MEVVA) ion source which had only recently been invented by Brown and co-workers, J. Galvin and R. MacGill, at Lawrence Berkeley Laboratory. For those of us involved in vacuum arc centrifuge research, this was an exciting development primarily because the metal vapour vacuum arc plasma source was common to both devices. Thus, a type of arc, which had since the 1930`s been extensively investigated as a means of switching high current loads, had found wider application as a useful plasma source.

  9. Clinical utility of RapidArcTM radiotherapy technology

    Directory of Open Access Journals (Sweden)

    Infusino E

    2015-11-01

    Full Text Available Erminia Infusino Department of Radiotherapy, Campus Bio-Medico University Hospital, Rome, Italy Abstract: RapidArcTM is a radiation technique that delivers highly conformal dose distributions through the complete rotation (360° and speed variation of the linear accelerator gantry. This technique, called volumetric modulated arc therapy (VMAT, compared with conventional radiotherapy techniques, can achieve high-target volume coverage and sparing damage to normal tissues. RapidArc delivers precise dose distribution and conformity similar to or greater than intensity-modulated radiation therapy in a short time, generally a few minutes, to which image-guided radiation therapy is added. RapidArc has become a currently used technology in many centers, which use RapidArc technology to treat a large number of patients. Large and small hospitals use it to treat the most challenging cases, but more and more frequently for the most common cancers. The clinical use of RapidArc and VMAT technology is constantly growing. At present, a limited number of clinical data are published, mostly concerning planning and feasibility studies. Clinical outcome data are increasing for a few tumor sites, even if only a little. The purpose of this work is to discuss the current status of VMAT techniques in clinical use through a review of the published data of planning systems and clinical outcomes in several tumor sites. The study consisted of a systematic review based on analysis of manuscripts retrieved from the PubMed, BioMed Central, and Scopus databases by searching for the keywords "RapidArc", "Volumetric modulated arc radiotherapy", and "Intensity-modulated radiotherapy". Keywords: IMRT, VMAT, SBRT, SRS, treatment planning software 

  10. Investigation of Optimal Control System for Arc Spraying

    Institute of Scientific and Technical Information of China (English)

    LI He-qi; LI Chun-xu; CHEN Ke-xuan; LU Guang

    2004-01-01

    An arc voltage feedback PID controller and arc current feedback PID controller are designed with a control algorithm of discrete PID separately to realize optimal control in computer controlling arc-spraying system. In order to realize optimization and adaptation of the arc-spraying process parameters as well as to reduce blindness in selecting process parameters, a serial communication interface between a PC for spraying data acquisition and a MCU of the control system is designed so that on-line modification of the PID control parameters is implemented. At the same time, a genetic algorithm is adopted to optimize the control parameters of PID controller, where the difference between the actually sampled value and the setting value of spraying current is made as the judgment criterion to determine the adaptability. The given range of control parameters varies from 0 to 15 and is to be encoded by a coding of four-bit binary string. The optimal population of control parameters of the PID controller can be obtained through reproduction, crossing and mutation,so that the optimal controlling in arc-spraying process is realized and an excellent coating of arc spraying is obtained.

  11. Optimal partial-arcs in VMAT treatment planning

    CERN Document Server

    Wala, Jeremiah; Chen, Wei; Craft, David

    2012-01-01

    Purpose: To improve the delivery efficiency of VMAT by extending the recently published VMAT treatment planning algorithm vmerge to automatically generate optimal partial-arc plans. Methods and materials: A high-quality initial plan is created by solving a convex multicriteria optimization problem using 180 equi-spaced beams. This initial plan is used to form a set of dose constraints, and a set of partial-arc plans is created by searching the space of all possible partial-arc plans that satisfy these constraints. For each partial-arc, an iterative fluence map merging and sequencing algorithm (vmerge) is used to improve the delivery efficiency. Merging continues as long as the dose quality is maintained above a user-defined threshold. The final plan is selected as the partial arc with the lowest treatment time. The complete algorithm is called pmerge. Results: Partial-arc plans are created using pmerge for a lung, liver and prostate case, with final treatment times of 127, 245 and 147 seconds. Treatment times...

  12. Investigation of Optimal Control System for Arc Spraying

    Institute of Scientific and Technical Information of China (English)

    LIHe-qi; LIChun-xu; CHENKe-xuan; LUGuang

    2004-01-01

    An arc voltage feedback PID controller and arc current feedback PID controller are designed with a controlal gorithm of discrete PID separately to realize optimal control in computer controlling arc-spraying system. In order to realize optimization and adaptation of the arc-spraying process parameters as well as to reduce blindness in selecting process parameters, a serial communication interface between a PC for spraying data acquisition and a MCU of the control system is designed so that on-line modification of the PID control parameters is implemented. At the same time, a genetic algorithm is adopted to optimize the control parameters of PID controller, where the difference between the actually sampled value and the setting value of spraying current is made as the judgment criterion to determine the adaptability. The given range of control parameters varies from 0 to 15 and is to be encoded by a coding of four-bit binary string. The optimal population of control parameters of the PID controller can be obtained through reproduction, crossing and mutation, so that the optimal controlling in arc-spraying process is realized and an excellent coating of arc spraying is obtained.

  13. Heat transfer modeling of double-side arc welding

    CERN Document Server

    Sun Jun Sheng; Zhang Yan Ming

    2002-01-01

    If a plasma arc and a TIG arc are connected in serial and with the plasma arc placed on the obverse side and the TIG arc on the opposite side of the workpiece, a special double-side arc welding (DSAW) system will be formed, in which the PAW current is forced to flow through the keyhole along the thickness direction so as to compensate the energy consumed for melting the workpiece and improve the penetration capacity of the PAW arc. By considering the mechanics factors which influence the DSAW pool geometric shape, the control equations of the pool surface deformation are derived, and the mathematics mode for DSAW heat transfer is established by using boundary-fitted non-orthogonal coordinate systems. With this model, the difference between DSAW and PAW heat transfer is analyzed and the reason for the increase of DSAW penetration is explained from the point of heat transfer. The welding process experiments show that calculated results are in good agreement with measured ones

  14. Arc Behavior and Droplet Transfer of CWW CO2 Welding

    Institute of Scientific and Technical Information of China (English)

    Zhi-dong YANG; Chen-fu FANG; Yong CHEN; Guo-xiang XU; Qing-xian HU; Xiao-yan GU

    2016-01-01

    Cable-type welding wire (CWW)CO2 welding is an innovative process arc welding with high quality,high efficiency and energy saving,in which CWW is used as consumable electrode.The CWW is composed of seven wires with a diameter of 1.2 mm.One is in the center,while others uniformly distribute around it.The diameter of twisted wire is up to 3.6 mm,which can increase the deposition rate significantly.With continual wire-feeding and melting of CWW,the formed rotating arc improved welding quality obviously.The arc behavior and droplet transfer were ob-served by the electrical signal waveforms and corresponding synchronous images,based on the high speed digital camera and electrical signal system.The results showed that the shape of welding arc changed from bell arc to beam arc with the increase of welding parameter.The droplet transfer mode changed from repelled transfer,globular transfer to projected transfer in turn.Droplet transfer frequency increased from 18.17 Hz to 119.05 Hz,while the droplet diameter decreased from 1.5 times to 0.3 times of the CWW diameter.

  15. Iridium: failures & successes

    Science.gov (United States)

    Christensen, CarissaBryce; Beard, Suzette

    2001-03-01

    This paper will provide an overview of the Iridium business venture in terms of the challenges faced, the successes achieved, and the causes of the ultimate failure of the venture — bankruptcy and system de-orbit. The paper will address technical, business, and policy issues. The intent of the paper is to provide a balanced and accurate overview of the Iridium experience, to aid future decision-making by policy makers, the business community, and technical experts. Key topics will include the history of the program, the objectives and decision-making of Motorola, the market research and analysis conducted, partnering strategies and their impact, consumer equipment availability, and technical issues — target performance, performance achieved, technical accomplishments, and expected and unexpected technical challenges. The paper will use as sources trade media and business articles on the Iridium program, technical papers and conference presentations, Wall Street analyst's reports, and, where possible, interviews with participants and close observers.

  16. Premature ovarian failure.

    Science.gov (United States)

    Shelling, Andrew N

    2010-11-01

    Premature ovarian failure (POF) is a common cause of infertility in women, and is characterised by amenorrhoea, hypo-oestrogenism and elevated gonadotrophin levels in women under the age of 40. Known causes include iatrogenic agents that cause permanent damage to the ovaries, such as chemotherapy, radiation therapy and surgery, autoimmune conditions, X-chromosome abnormalities and autosomal genetic conditions. However, few genes have been identified that can explain a substantial proportion of cases of POF. Most women with POF are deeply upset by the diagnosis, partly due to the unexpected menopausal symptoms, but also due to infertility. Therefore, early detection would provide better opportunity for early intervention, and furthermore, the identification of specific gene defects will help to direct potential targets for future treatment.

  17. Premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Vujović Svetlana

    2012-01-01

    Full Text Available Premature ovarian failure (POF is the occurrence of hypergonadotropic hypoestrogenic amenorrhea in women under the age of forty years. It is idiopathic in 74-90% patients. Known cases can be divided into primary and secondary POF. In primary POF genetic aberrations can involve the X chromosome (monosomy, trisomy, translocations, deletions or autosomes. Genetic mechanisms include reduced gene dosage and non-specific chromosome effects impairing meiosis, decreasing the pool of primordial follicles and increasing atresia due to apoptosis or failure of follicle maturation. Autoimmune ovarian damage is caused by alteration of T-cell subsets and T-cell mediated injury, increase of autoantibody producing B-cells, a low number of effector/cytotoxic lymphocyte, which decreases the number and activity of natural killer cells. Bilateral oophorectomy, chemotherapy, radiotherapy and infections cause the secondary POF. Symptoms of POF include irritability, nervousness, loss of libido, depression, lack of concentration, hot flushes, weight gaining, dry skin, vaginal dryness, frequent infections etc. The diagnosis is confirmed by the level of FSH of over 40 IU/L and estradiol below 50 pmol/L in women aged below 40 years. Biochemical and other hormonal analysis (free thyroxin, TSH, prolactin, testosterone, karyotype (<30 years of age, ultrasound of the breasts and pelvis are advisable. Optimal therapy is combined estrogen progestagen therapy given in a sequential rhythm, after excluding absolute contraindications. Testosterone can be added to adnexectomized women and those with a low libido. Sequential estrogen progestagen replacement therapy is the first line therapy for ovulation induction in those looking for pregnancy and after that oocyte donation will be advised. Appropriate estro-progestagen therapy improves the quality of life and prevents complications such as cardiovascular diseases, osteoporosis, stroke etc.

  18. Strategies of learning from failure.

    Science.gov (United States)

    Edmondson, Amy C

    2011-04-01

    Many executives believe that all failure is bad (although it usually provides Lessons) and that Learning from it is pretty straightforward. The author, a professor at Harvard Business School, thinks both beliefs are misguided. In organizational life, she says, some failures are inevitable and some are even good. And successful learning from failure is not simple: It requires context-specific strategies. But first leaders must understand how the blame game gets in the way and work to create an organizational culture in which employees feel safe admitting or reporting on failure. Failures fall into three categories: preventable ones in predictable operations, which usually involve deviations from spec; unavoidable ones in complex systems, which may arise from unique combinations of needs, people, and problems; and intelligent ones at the frontier, where "good" failures occur quickly and on a small scale, providing the most valuable information. Strong leadership can build a learning culture-one in which failures large and small are consistently reported and deeply analyzed, and opportunities to experiment are proactively sought. Executives commonly and understandably worry that taking a sympathetic stance toward failure will create an "anything goes" work environment. They should instead recognize that failure is inevitable in today's complex work organizations.

  19. Failure Mode/Mechanism Distributions

    Science.gov (United States)

    1991-09-01

    nsc. Modas /Mach Dist. Dist. Suurce(,%)/Detai19 Bolt, MahineSources :1 Brcikon 𔃺.1% 59.0% Broken Bolt(s) (25j01-(000,Qty:l) C25101-000,Qty:Ij., Part...Center (RAC) * 201 Mill St., Rome, NY 13440 * 315-337-0900 3-114 Failure Distribution Summaries FMD-91 ? art Failure Norm Fail Data Docm. Mode/Moch Dist... Deco . Mode/Mech Dist. Dist. Source(s)/Details Lamp,Bulb Sourcent 4 Lamp Failure 68.8% 53.8% Light Bulb Failure (23038-00l,Qty:3) (23038-004,Qty:l

  20. A Failure Criterion for Concrete

    DEFF Research Database (Denmark)

    Ottosen, N. S.

    1977-01-01

    A four-parameter failure criterion containing all the three stress invariants explicitly is proposed for short-time loading of concrete. It corresponds to a smooth convex failure surface with curved meridians, which open in the negative direction of the hydrostatic axis, and the trace in the devi......A four-parameter failure criterion containing all the three stress invariants explicitly is proposed for short-time loading of concrete. It corresponds to a smooth convex failure surface with curved meridians, which open in the negative direction of the hydrostatic axis, and the trace...

  1. Investigation of Voltage Unbalance Problems In Electric Arc Furnace Operation Model

    OpenAIRE

    Yacine DJEGHADER; Hocine LABAR

    2013-01-01

    In modern steel industry, Electric Arc Furnaces are widely used for iron and scarp melting. The operation of electric arc furnace causes many power quality problems such as harmonics, unbalanced voltage and flicker. The factors that affect Electric arc furnace operation are the melting or refining materials, melting stage, electrodes position (arc length), electrode arm control and short circuit power of the feeder, so, arc voltages, current and power are defined as a nonlinear function of ar...

  2. Reinvestigation of the charge density distribution in arc discharge fusion system

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Lin Horng; Yee, Lee Kim; Nan, Phua Yeong; Thung, Yong Yun; Khok, Yong Thian; Rahman, Faidz Abd [Centre of Photonics and Advance Material, Universiti Tunku Abdul Rahman Kuala Lumpur (Malaysia)

    2015-04-24

    A continual arc discharge system has been setup and the light intensity of arc discharge has been profiled. The mathematical model of local energy density distribution in arc discharge fusion has been simulated which is in good qualitative agreement with light intensity profile of arc discharge in the experiments. Eventually, the local energy density distribution of arc discharge system is able to be precisely manipulated to act as heat source in the fabrication of fused fiber devices.

  3. Deep structure of the central Lesser Antilles Island Arc : relevance for the formation of continental crust

    OpenAIRE

    H. Kopp; Weinzierl, W.; Becel, A.; Charvis, Philippe; Evain, M.; Flueh, E. R.; Gailler, A.; Galve, A.; Hirn, A.; Kandilarov, A.; D. Klaeschen; M. Laigle; Papenberg, C.; L. Planert; Roux, E.

    2011-01-01

    Oceanic island arcs are sites of high magma production and contribute to the formation of continental crust. Geophysical studies may provide information on the configuration and composition of island arc crust, however, to date only few seismic profiles exist across active island arcs, limiting our knowledge on the deep structure and processes related to the production of arc crust. We acquired active-source wide-angle seismic data crossing the central Lesser Antilles island arc north of Domi...

  4. Public Choice, Market Failure, and Government Failure in Principles Textbooks

    Science.gov (United States)

    Fike, Rosemarie; Gwartney, James

    2015-01-01

    Public choice uses the tools of economics to analyze how the political process allocates resources and impacts economic activity. In this study, the authors examine twenty-three principles texts regarding coverage of public choice, market failure, and government failure. Approximately half the texts provide coverage of public choice and recognize…

  5. Anhydrite solubility in differentiated arc magmas

    Science.gov (United States)

    Masotta, M.; Keppler, H.

    2015-06-01

    The solubility of anhydrite in differentiated arc magmas was experimentally studied at 200 MPa and 800-1000 °C over a range of oxygen fugacities, from 0.5 log units above the Ni-NiO buffer to the hematite-magnetite buffer. Anhydrite is stable only at oxidizing conditions (fO2 ⩾ Re-ReO2), whereas sulfides only form under reducing conditions. The solubility of anhydrite in the melt ultimately regulates the amount of sulfur available to partition between melt and fluid phase during the eruption. At oxidizing conditions, the solubility product of anhydrite increases with temperature, nbo/t and melt water content. We provide a new calibration of the anhydrite solubility product (KSP = XCaO * XSO3), which reproduces all available experimental data with greatly improved accuracy: In this equation, the molar fractions XCaO and XSO3 in the melt as well as the number of non-bridging oxygen atoms per tetrahedron (nbo/t) are calculated on an anhydrous basis (H2O refers to the melt water content, T is temperature in Kelvin). We apply our model to estimate the sulfur yield of some recent volcanic eruptions and we show that the sulfur yield of the 1991 Mt. Pinatubo dacite eruption was unusually large, because only a small fraction of the sulfur was locked up in anhydrite. In general, high sulfur yields are expected when anhydrite solubility in the melt is high, i.e. for somewhat depolymerized melts. For rhyolitic systems, most of the available sulfur will be locked up in anhydrite, so that even very large eruptions may only have a small effect on global surface temperatures. Our model therefore allows improved predictions of the environmental impact of explosive volcanic eruptions.

  6. Structural ceramics containing electric arc furnace dust.

    Science.gov (United States)

    Stathopoulos, V N; Papandreou, A; Kanellopoulou, D; Stournaras, C J

    2013-11-15

    In the present work the stabilization of electric arc furnace dust EAFD waste in structural clay ceramics was investigated. EAFD was collected over eleven production days. The collected waste was characterized for its chemical composition by Flame Atomic Absorption Spectroscopy. By powder XRD the crystal structure was studied while the fineness of the material was determined by a laser particle size analyzer. The environmental characterization was carried out by testing the dust according to EN12457 standard. Zn, Pb and Cd were leaching from the sample in significant amounts. The objective of this study is to investigate the stabilization properties of EAFD/clay ceramic structures and the potential of EAFD utilization into structural ceramics production (blocks). Mixtures of clay with 2.5% and 5% EAFD content were studied by TG/DTA, XRD, SEM, EN12457 standard leaching and mechanical properties as a function of firing temperature at 850, 900 and 950 °C. All laboratory facilities maintained 20 ± 1 °C. Consequently, a pilot-scale experiment was conducted with an addition of 2.5% and 5% EAFD to the extrusion mixture for the production of blocks. During blocks manufacturing, the firing step reached 950 °C in a tunnel kiln. Laboratory heating/cooling gradients were similar to pilot scale production firing. The as produced blocks were then subjected to quality control tests, i.e. dimensions according to EN772-17, water absorbance according to EN772-6, and compressive strength according to EN772-1 standard, in laboratory facilities certified under EN17025. The data obtained showed that the incorporation of EAFD resulted in an increase of mechanical strength. Moreover, leaching tests performed according to the Europeans standards on the EAFD-block samples showed that the quantities of heavy metals leached from crushed blocks were within the regulatory limits. Thus the EAFD-blocks can be regarded as material of no environmental concern.

  7. ArcGIS Framework for Scientific Data Analysis and Serving

    Science.gov (United States)

    Xu, H.; Ju, W.; Zhang, J.

    2015-12-01

    ArcGIS is a platform for managing, visualizing, analyzing, and serving geospatial data. Scientific data as part of the geospatial data features multiple dimensions (X, Y, time, and depth) and large volume. Multidimensional mosaic dataset (MDMD), a newly enhanced data model in ArcGIS, models the multidimensional gridded data (e.g. raster or image) as a hypercube and enables ArcGIS's capabilities to handle the large volume and near-real time scientific data. Built on top of geodatabase, the MDMD stores the dimension values and the variables (2D arrays) in a geodatabase table which allows accessing a slice or slices of the hypercube through a simple query and supports animating changes along time or vertical dimension using ArcGIS desktop or web clients. Through raster types, MDMD can manage not only netCDF, GRIB, and HDF formats but also many other formats or satellite data. It is scalable and can handle large data volume. The parallel geo-processing engine makes the data ingestion fast and easily. Raster function, definition of a raster processing algorithm, is a very important component in ArcGIS platform for on-demand raster processing and analysis. The scientific data analytics is achieved through the MDMD and raster function templates which perform on-demand scientific computation with variables ingested in the MDMD. For example, aggregating monthly average from daily data; computing total rainfall of a year; calculating heat index for forecasting data, and identifying fishing habitat zones etc. Addtionally, MDMD with the associated raster function templates can be served through ArcGIS server as image services which provide a framework for on-demand server side computation and analysis, and the published services can be accessed by multiple clients such as ArcMap, ArcGIS Online, JavaScript, REST, WCS, and WMS. This presentation will focus on the MDMD model and raster processing templates. In addtion, MODIS land cover, NDFD weather service, and HYCOM ocean model

  8. Review on research progress of Arc Hydro and Arc Hydro Groundwater hydrological data model%Arc Hydro与Arc Hydro Groundwater水文数据模型研究综述

    Institute of Scientific and Technical Information of China (English)

    崔素芳; 张保祥; 崔峻岭; 潘英华; 张振华; 吴泉源; 衣华鹏

    2016-01-01

    由于目前在地表水与地下水的联合模拟研究中备受青睐的Arc Hydro与Arc Hydro Groundwater水文数据模型能否应用于水文模拟尚缺少实证性研究,通过查阅大量文献资料,分析这两个水文数据模型的功能和优点,以及存在的问题和未来发展趋势。指出Arc Hydro模型虽然具备强大的水文分析与提取功能,但其本身并不能实现水文模拟,必须与独立的水文模型利用数据交换来完成水文模拟;Arc Hydro Groundwater模型虽然包含MODFLOW分析模型,但只能对MODFLOW模型输出的结果进行可视化处理,目前还不具备独立的地下水模拟功能。认为地表水与地下水联合模型与GIS耦合集成平台的开发将是未来研究的热点。%Arc Hydro and Arc Hydro Groundwater hydrological data model are favored by scholars in the joint simulation of surface water and groundwater, but empirical researches on whether hydrological simulation can apply Arc Hydro and Arc Hydro Groundwater model are lack. According to this problem, the functions and advantages of these two hydrological models were analyzed, furthermore, the remaining problems and the development trend were also discussed by a review of a large number of documents. It is pointed out that although Arc Hydro has function of strong hydrological analysis and extraction, this model cannot realize hydrological simulation, data exchange is necessary to complete hydrological simulation with independent hydrological model. Arc Hydro Groundwater contains MODFLOW analysis model, however, it only can visualize process for MODFLOW model outputs and does not yet have independent groundwater simulation function. The development of integrated platform combining joint simulation model of surface water and groundwater with GIS coupling is supposed to be a hot research.

  9. Instability of a Short Anodic Arc Used for Synthesis of Nanomaterials

    Science.gov (United States)

    Gershman, Sophia; Raitses, Yevgeny

    2016-10-01

    The short anodic arc discharge is used for the synthesis of nanomaterials and had been presumed stable. We report the results of electrical and fast imaging measurements that reveal a combined motion of the arc column and the arc attachment region to the anode when the arc is operated with a high ablation rate. The arc exhibits a negative differential resistance before the arc motion occurs. The observed arc motion correlates with the arc voltage and current oscillations. The characteristic time of these instabilities is in a 10-3 sec range. Thermal processes in the arc plasma region interacting with the ablating anode are considered as possible causes of this unstable arc behavior. The measured negative differential resistance of the arc during the oscillations indirectly supports the thermal model. Our model suggests that the injection of the ablating material into the plasma locally reduces the energy flux to the surface and leads to the arc shifting to the adjacent position. The observed arc motion can potentially cause the mixing of the various nanoparticles synthesized in the arc in the high ablation regime leading to the poor selectivity characteristic of the arc synthesis of nanomaterials. US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

  10. Comparison study of intensity modulated arc therapy using single or multiple arcs to intensity modulated radiation therapy for high-risk prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ashamalla, Hani; Tejwani, Ajay; Parameritis, Loannis; Swamy, Uma; Luo, Pei Ching; Guirguis, Adel; Lavaf, Amir [Weill Medical College of Cornell University, Brooklyn, NY (United States)

    2013-06-15

    Intensity modulated arc therapy (IMAT) is a form of intensity modulated radiation therapy (IMRT) that delivers dose in single or multiple arcs. We compared IMRT plans versus single-arc field (1ARC) and multi-arc fields (3ARC) IMAT plans in high-risk prostate cancer. Sixteen patients were studied. Prostate (PTV{sub P}), right pelvic (PTV{sub RtLN}) and left pelvic lymph nodes (PTV{sub LtLN}), and organs at risk were contoured. PTVP, PTV{sub RtLN}, and PTV{sub LtLN} received 50.40 Gy followed by a boost to PTV{sub B} of 28.80 Gy. Three plans were per patient generated: IMRT, 1ARC, and 3ARC. We recorded the dose to the PTV, the mean dose (D{sub MEAN}) to the organs at risk, and volume covered by the 50% isodose. Efficiency was evaluated by monitor units (MU) and beam on time (BOT). Conformity index (CI), Paddick gradient index, and homogeneity index (HI) were also calculated. Average Radiation Therapy Oncology Group CI was 1.17, 1.20, and 1.15 for IMRT, 1ARC, and 3ARC, respectively. The plans' HI were within 1% of each other. The D{sub MEAN} of bladder was within 2% of each other. The rectum D{sub MEAN} in IMRT plans was 10% lower dose than the arc plans (p < 0.0001). The GI of the 3ARC was superior to IMRT by 27.4% (p = 0.006). The average MU was highest in the IMRT plans (1686) versus 1ARC (575) versus 3ARC (1079). The average BOT was 6 minutes for IMRT compared to 1.3 and 2.9 for 1ARC and 3ARC IMAT (p < 0.05). For high-risk prostate cancer, IMAT may offer a favorable dose gradient profile, conformity, MU and BOT compared to IMRT.

  11. A Carbon Arc Apparatus For Production Of Nanotubes In Microgravity

    Science.gov (United States)

    Alford, J. M.; Mason, G. R.; Feikema, D. A.

    2003-01-01

    Although many methods are available for production of single-walled carbon nanotubes (SWNTs), the conventional carbon arc process remains the most popular due to its simplicity and large production rate. However, high temperatures inside the carbon arc generate strong buoyancy driven convection, and it is hypothesized that the non-uniform environment created by this flow will have large effects on the growth and morphology of SWNTs produced by the arc process. Indeed, using normal gravity experiments, Marin et al. have demonstrated that changes in the buoyant convection plume produced by altering the arc electrode orientation can be used to change the diameter distribution of the SWNTs produced; an effect they attribute to changes in the temperature of the local nanotube growth environment. While these experiments present convincing evidence that buoyant convection has a strong effect on nanotube growth, normal gravity experiments are severely limited in scope. The ideal way to study the effect of buoyancy on SWNT production is to remove it completely. Toward this goal, a microgravity carbon arc reactor has been designed for use in the NASA Glenn 2.2 and 5 second drop towers. Although simple in principle, conventional carbon arc machines, which generally employ large reaction chambers and require heavy duty welding power supplies capable of supplying kilowatts of power, are not suitable for microgravity experiments. Here we describe a miniature carbon arc machine for SWNT production that fits into a conventional drop rig for use on the NASA Glenn 2.2 and 5 second drop towers, but that has a performance (production rate) that is better than most large ground-based machines.

  12. Electrical and hydrodynamic characterization of a high current pulsed arc

    Science.gov (United States)

    Sousa Martins, R.; Chemartin, L.; Zaepffel, C.; Lalande, Ph; Soufiani, A.

    2016-05-01

    High current pulsed arcs are of significant industrial interest and, aiming to reduce time and cost, there is progressively more and more need for computation tools that describe and predict the behaviour of these arcs. These simulation codes need inputs and validations by experimental databases, but accurate data is missing for this category of electric discharges. The principal lack of understanding is with respect to the transient phase of the current, which can reach thousands of amperes in a few microseconds. In this paper, we present the work realized on an experimental setup that simulates in the laboratory an arc column subjected to five levels of high pulsed current, ranging from 10 kA to 100 kA, with the last one corresponding to the standard lightning current waveform used in aircraft certification processes. This device was instrumented by high speed video cameras to assess the characteristic sizes of the arc channel and to characterize the shock wave generated by the arc expansion. The arc channel radius was measured over time during the axisymmetric phase and reached 3.2 cm. The position and velocity of the shock wave was determined during the first 140 μs. The background-oriented schlieren method was used to study the shock wave and a model for the light deflection inside the shock wave was developed. The mass density profile of the shock wave was estimated and showed good agreement with Rankine-Hugoniot relations at the wave front. Electrical measurements were also used to estimate the time-dependent resistance and conductivity of the arc for times lasting up to 50 μs.

  13. Electrode voltage fall and total voltage of a transient arc

    Science.gov (United States)

    Valensi, F.; Ratovoson, L.; Razafinimanana, M.; Masquère, M.; Freton, P.; Gleizes, A.

    2016-06-01

    This paper deals with an experimental study of the components of a transient arc total voltage with duration of a few tens of ms and a current peak close to 1000 A. The cathode tip is made of graphite whereas the flat anode is made either of copper or of graphite; the electrodes gap is a few mm. The analysis of the electrical parameters is supported and validated by fast imaging and by two models: the first one is a 2D physical model of the arc allowing to calculate both the plasma temperature field and the arc voltage; the second model is able to estimate the transient heating of the graphite electrode. The main aim of the study was to detect the possible change of the cathode voltage fall (CVF) during the first instants of the arc. Indeed it is expected that during the first ms the graphite cathode is rather cool and the main mechanism of the electron emission should be the field effect emission, whereas after several tens of ms the cathode is strongly heated and thermionic emission should be predominant. We have observed some change in the apparent CVF but we have shown that this apparent change can be attributed to the variation of the solid cathode resistance. On the other hand, the possible change of CVF corresponding to the transition between a ‘cold’ and a ‘hot’ cathode should be weak and could not be characterized considering our measurement uncertainty of about 2 V. The arc column voltage (ACV) was estimated by subtracting the electrode voltage fall from the total arc voltage. The experimental transient evolution of the ACV is in very good agreement with the theoretical variation predicted by the model, showing the good ability of the model to study this kind of transient arc.

  14. Aging, telomeres and heart failure

    NARCIS (Netherlands)

    Wong, Liza S. M.; van der Harst, Pim; de Boer, Rudolf A.; Huzen, Jardi; van Gilst, Wiek H.; van Veldhuisen, Dirk J.

    2010-01-01

    During normal aging, the heart undergoes functional, morphological and cellular changes. Although aging per se does not lead to the expression of heart failure, it is likely that age-associated changes lower the threshold for the manifestation of signs and symptoms of heart failure. In patients, the

  15. Failure Engineered Heavy Metal Penetrators

    Science.gov (United States)

    1992-12-01

    ARMY RESEARCH LABORATORY Failure Engineered Heavy Metal Penetrators, Phase I, SBIR ARL-CR-5· R. Cavalieri, W. Tiarn, and D. Nicholson prepared...REPORT DATE S. REPORT TYPE AND DATES COVERED December 1992 Final Report-1/1/92 - 7/31/92 4. TITLE AND SUBTITLE FAILURE ENGINEERED HEAVY METAL PENETRATORS

  16. Corrosion Failures in Marine Environment

    Directory of Open Access Journals (Sweden)

    R. Krishnan

    1985-04-01

    Full Text Available This paper gives a brief description of typical marine environments and the most common form of corrosion of materials used in this environment. Some typical case histories of failures pertaining to pitting, bimetallic corrosion, dealloying, cavitation and stress corrosion cracking are illustrated as typical examples of corrosion failures.

  17. Sex differences in heart failure

    NARCIS (Netherlands)

    Meyer, Sven

    2016-01-01

    This thesis examined differences between men and women with heart failure. First, it was shown that biological sex is a strong modulator in the clinical expression of various cardiomyopathies. In the general population it was shown that men are more likely to develop heart failure with reduced eject

  18. Failure Rates in Introductory Programming

    DEFF Research Database (Denmark)

    Bennedsen, Jens; Caspersen, Michael Edelgaard

    2007-01-01

    It is a common conception that CS1 is a very difficult course and that failure rates are high. However, until now there has only been anecdotal evidence for this claim. This article reports on a survey among institutions around the world regarding failure rates in introductory programming courses...

  19. Intestinal failure in obstructive jaundice

    Institute of Scientific and Technical Information of China (English)

    Stelios F. Assimakopoulos; Constantine E. Vagianos; Aristides Charonis; Vassiliki N. Nikolopoulou; Chrisoula D. Scopa

    2005-01-01

    @@ TO THE EDITOR We read with great interest the article by Ding LA and LiJS, which aimed to review the current knowledge on the physiology of normal intestinal barrier function and highlight the role of intestinal failure after various injurious insults in the development of septic complications or multiple organ failure with subsequent rapid clinical deterioration or even death.

  20. Petrogenesis of Late Cretaceous lava flows from a Ceno-Tethyan island arc: The Raskoh arc, Balochistan, Pakistan

    Science.gov (United States)

    Siddiqui, Rehanul Haq; Qasim Jan, M.; Asif Khan, M.

    2012-10-01

    The Raskoh arc is about 250 km long, 40 km wide and trends in an ENE direction. The oldest rock unit in the Raskoh arc is an accretionary complex (Early to Late Jurassic), which is followed in age by Kuchakki Volcanic Group, the most wide spread unit of the Raskoh arc. The Volcanic Group is mainly composed of basaltic to andesitic lava flows and volcaniclastics, including agglomerate, volcanic conglomerate, breccia and tuff, with subordinate shale, sandstone, limestone and chert. The flows generally form 3-15 m thick lenticular bodies but rarely reach up to 300 m. They are mainly basaltic-andesites with minor basalts and andesites. The main textures exhibited by these rocks are hypocrystalline porphyritic, subcumulophyric and intergranular. The phenocrysts comprise mainly plagioclase (An30-54 in Nok Chah and An56-64 in Bunap). They are embedded in a micro-cryptocrystalline groundmass having the same minerals. Apatite, magnetite, titanomagnetite and hematite occur as accessory minerals. Major, trace and rare earth elements suggest that the volcanics are oceanic island arc tholeiites. Their low Mg # (42-56) and higher FeO (total)/MgO (1.24-2.67) ratios indicate that the parent magma of these rocks was not directly derived from a mantle source but fractionated in an upper level magma chamber. The trace element patterns show enrichment in LILE and depletion in HFSE relative to N-MORB. Their primordial mantle-normalized trace element patterns show marked negative Nb anomalies with positive spikes on K, Ba and Sr which confirm their island arc signatures. Slightly depleted LREE to flat chondrite normalized REE patterns further support this interpretation. The Zr versus Zr/Y and Cr versus Y studies show that their parent magma was generated by 20-30% melting of a depleted mantle source. The trace elements ratios including Zr/Y (1.73-3.10), Ti/Zr (81.59-101.83), Ti/V (12.39-30.34), La/YbN (0.74-2.69), Ta/Yb (0.02-0.05) and Th/Yb (0.11-0.75) of the volcanics are more

  1. The composition of the modern juvenile arc crust and the nature of crustal delaminates in arcs (Invited)

    Science.gov (United States)

    Jagoutz, O. E.; Schmidt, M. W.

    2010-12-01

    The intraoceanic Kohistan arc, northern Pakistan, exposes a complete crustal section encompassing infracrustal cumulates formed at ≥ 55 km depth, a broadly basaltic/gabbroic lower crust, a 26 km thick calc-alkaline batholith, and 4 km of a volcanoclastic/sedimentary sequence. The bulk composition of the Kohistan arc crust has been approximated by estimating the relative volumes of exposed rocks through detailed field observations in combination with geobarometric constrains of the units' thicknesses and satellite images for lateral extension. We separated the arc in 3 major lower, mid-, and mid- to upper crustal units containing 14 subunits which compositions were derived from averaging 562 whole rock analyses. The details of the resulting bulk composition depend slightly on the method of integration, but all models yield andesitic bulk supra MOHO compositions. The Kohistan bulk arc composition results very similar to global continental crust estimates indicating that modern arc activity is the dominant process that formed the (preserved) continental crust. Fitting the bulk Kohistan arc crust and the ultramafic cumulates exposed at base of the arc (dunites, wehrlites, websterites, cpx-bearing garnetites and hornblendites, and garnet gabbros) to primitive arc melts with calc-alkaline/tholeiitic, alkaline, and boninitic affinity from various island arcs demonstrates that delamination of wehrlites + garnet hornblendites ± garnet gabbros perfectly explains the evolution from a tholeiitic/calc-alkaline primitive high-Mg basalt to the continental crust. Mass balance demonstrates that volumes of delaminate similar to the continental crust are required. Compared to depleted mantle, the delaminate is enriched in K, Cs, Ba and Pb and depleted in Zr and Th. It has further a subchondritic Nb/Ta and the high Pb and low U concentrations lead to a very unradiogenic Pb isotopy that may compensate for the depleted mantle Our results document that infra arc processes even in a

  2. Adult intestinal failure

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J., E-mail: Jdavidson@doctors.org.u [Salford Royal Hospital, Salford (United Kingdom); Plumb, A.; Burnett, H. [Salford Royal Hospital, Salford (United Kingdom)

    2010-05-15

    Intestinal failure (IF) is the inability of the alimentary tract to digest and absorb sufficient nutrition to maintain normal fluid balance, growth, and health. It commonly arises from disease affecting the mesenteric root. Although severe IF is usually managed in specialized units, it lies at the end of a spectrum with degrees of nutritional compromise being widely encountered, but commonly under-recognized. Furthermore, in the majority of cases, the initial enteric insult occurs in non-specialist IF centres. The aim of this article is to review the common causes of IF, general principles of its management, some commoner complications, and the role of radiology in the approach to a patient with severe IF. The radiologist has a crucial role in helping provide access for feeding solutions (both enteral and parenteral) and controlling sepsis (via drainage of collections) in an initial restorative phase of treatment, whilst simultaneously mapping bowel anatomy and quality, and searching for disease complications to assist the clinicians in planning a later, restorative phase of therapy.

  3. A fault analysis of DC electric arc furnaces with SVC harmonic filters in a mini-mill plant

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byungju [PQ TECH INC., Youngtong-dong, Youngtong-gu, Suwon 443-813 (Korea); Lee, Hansang; Jang, Gilsoo [School of Electrical Engineering, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-701 (Korea); Han, Byungmoon [Department of Electrical Engineering, Myongji University, Nam-dong, Yongin, Gyeonggi-do, 449-728 (Korea)

    2010-07-15

    This paper proposes the most feasible solution to overcome the failure of the 2nd harmonic filter in the static VAR compensator (SVC) which operates with the DC electric arc furnace (EAF) at Gwangyang Steel Mill in Korea. In order to investigate the causes of this failure, various measurements were carried out on the DC EAF and the main transformer at the PCC (point of common connection). It was concluded that the two causes for the failure are; the inrush current in the main transformer, and the parallel resonance between the system impedance and the harmonic filter. Three solutions to suppress the transformer inrush current and another three solutions to avoid the parallel resonance are suggested. The feasibility of these solutions was verified through the computer simulation with PSCAD/EMTDC. The most feasible solution to avoid further failures of the 2nd harmonic filter was selected, based on the estimated result for the six optional solutions in the point of performance and cost. (author)

  4. Nuclear cardiology and heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Giubbini, Raffaele; Bertagna, Francesco [University of Brescia, Department of Nuclear Medicine, Brescia (Italy); Milan, Elisa [Ospedale Di Castelfranco Veneto, Nuclear Medicine Unit, Castelfranco Veneto (Italy); Mut, Fernando; Dondi, Maurizio [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Metra, Marco [University of Brescia, Department of Cardiology, Brescia (Italy); Rodella, Carlo [Health Physics Department, Spedali Civili di Brescia, Brescia (Italy)

    2009-12-15

    The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

  5. Failure Criteria for Reinforced Materials

    DEFF Research Database (Denmark)

    Rathkjen, Arne

    Failure of materials is often characterized as ductile yielding, brittle fracture, creep rupture, etc., and different criteria given in terms of different parameters have been used to describe different types of failure. Only criteria expressing failure in terms of stress are considered in what...... place until the matrix, the continuous component of the composite, fails. When an isotropic matrix is reinforced as described above, the result is an anisotropic composite material. Even if the material is anisotropic, it usually exhibits a rather high degree of symmetry and such symmetries place...... certain restrictions on the form of the failure criteria for anisotropic materials. In section 2, some failure criteria for homogenous materials are reviewed. Both isotropic and anisotropic materials are described, and in particular the constraints imposed on the criteria from the symmetries orthotropy...

  6. Numerical Tsunami Hazard Assessment of the Only Active Lesser Antilles Arc Submarine Volcano: Kick 'em Jenny.

    Science.gov (United States)

    Dondin, F. J. Y.; Dorville, J. F. M.; Robertson, R. E. A.

    2015-12-01

    The Lesser Antilles Volcanic Arc has potentially been hit by prehistorical regional tsunamis generated by voluminous volcanic landslides (volume > 1 km3) among the 53 events recognized so far. No field evidence of these tsunamis are found in the vincity of the sources. Such a scenario taking place nowadays would trigger hazardous tsunami waves bearing potentially catastrophic consequences for the closest islands and regional offshore oil platforms.Here we applied a complete hazard assessment method on the only active submarine volcano of the arc Kick 'em Jenny (KeJ). KeJ is the southernmost edifice with recognized associated volcanic landslide deposits. From the three identified landslide episodes one is associated with a collapse volume ca. 4.4 km3. Numerical simulations considering a single pulse collapse revealed that this episode would have produced a regional tsunami. An edifice current volume estimate is ca. 1.5 km3.Previous study exists in relationship to assessment of regional tsunami hazard related to shoreline surface elevation (run-up) in the case of a potential flank collapse scenario at KeJ. However this assessment was based on inferred volume of collapse material. We aim to firstly quantify potential initial volumes of collapse material using relative slope instability analysis (RSIA); secondly to assess first order run-ups and maximum inland inundation distance for Barbados and Trinidad and Tobago, i.e. two important economic centers of the Lesser Antilles. In this framework we present for seven geomechanical models tested in the RSIA step maps of critical failure surface associated with factor of stability (Fs) for twelve sectors of 30° each; then we introduce maps of expected potential run-ups (run-up × the probability of failure at a sector) at the shoreline.The RSIA evaluates critical potential failure surface associated with Fs sources characteristics are retrieved from numerical simulation using an hydraulic equations-based code (Volc

  7. Structural ceramics containing electric arc furnace dust

    Energy Technology Data Exchange (ETDEWEB)

    Stathopoulos, V.N., E-mail: vasta@teihal.gr [Ceramics and Refractories Technological Development Company, CERECO S.A., 72nd km Athens Lamia National Road, P.O. Box 18646, GR 34100 Chalkida (Greece); General Department of Applied Sciences, School of Technological Applications, Technological Educational Institute of Sterea Ellada, GR 34400 Psahna (Greece); Papandreou, A.; Kanellopoulou, D.; Stournaras, C.J. [Ceramics and Refractories Technological Development Company, CERECO S.A., 72nd km Athens Lamia National Road, P.O. Box 18646, GR 34100 Chalkida (Greece)

    2013-11-15

    Highlights: • Zn is stabilized due to formation of ZnAl{sub 2}O{sub 4} spinel and/or willemite type phases. • EAFD/clay fired mixtures exhibit improved mechanical properties. • Hollow bricks were successfully fabricated from the mixtures studied. • Laboratory articles and scaled up bricks found as environmentally inert materials. -- Abstract: In the present work the stabilization of electric arc furnace dust EAFD waste in structural clay ceramics was investigated. EAFD was collected over eleven production days. The collected waste was characterized for its chemical composition by Flame Atomic Absorption Spectroscopy. By powder XRD the crystal structure was studied while the fineness of the material was determined by a laser particle size analyzer. The environmental characterization was carried out by testing the dust according to EN12457 standard. Zn, Pb and Cd were leaching from the sample in significant amounts. The objective of this study is to investigate the stabilization properties of EAFD/clay ceramic structures and the potential of EAFD utilization into structural ceramics production (blocks). Mixtures of clay with 2.5% and 5% EAFD content were studied by TG/DTA, XRD, SEM, EN12457 standard leaching and mechanical properties as a function of firing temperature at 850, 900 and 950 °C. All laboratory facilities maintained 20 ± 1 °C. Consequently, a pilot-scale experiment was conducted with an addition of 2.5% and 5% EAFD to the extrusion mixture for the production of blocks. During blocks manufacturing, the firing step reached 950 °C in a tunnel kiln. Laboratory heating/cooling gradients were similar to pilot scale production firing. The as produced blocks were then subjected to quality control tests, i.e. dimensions according to EN772-17, water absorbance according to EN772-6, and compressive strength according to EN772-1 standard, in laboratory facilities certified under EN17025. The data obtained showed that the incorporation of EAFD resulted in

  8. Sub Moho boundary beneath island arc, Japan

    Science.gov (United States)

    Iidaka, T.; Igarashi, T.; Lee, C.; Iwasaki, T.; Niu, F.

    2008-12-01

    reflective to seismic waves as compared to the continental ones which are relatively transparent. Locations of the observed sub-Moho appear to correlate well with the active volcanic front, suggesting that the sub-Moho might be formed as the result of arc magmatism.

  9. The Influence of Contact Space on Arc Commutation Process in Air Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    NIU Chunping; DING Juwen; YANG Fei; DONG Delong; RONG Mingzhe; XU Dan

    2016-01-01

    In this paper,a 3D magneto-hydrodynamic (MHD) arc simulation model is applied to analyze the arc motion during current interruption in a certain air circuit breaker (ACB).The distributions of pressure,temperature,gas flow and current density of the arc plasma in the arc region are calculated,and the factors influencing the commutation process are analyzed according to the calculated results.Based on the airflow in the arc chamber,the causes of arc commutation asynchrony and the back commutation are investigated.It indicates that a reasonable contact space design is crucial to a successful arc commutation process.To verify the simulation results,the influence of contact space on arc voltage and arc commutation is tested.This research can provide methods and references to the optimization of ACB design.

  10. Physics characteristic of coupling arc of twin-tungsten TIG welding

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guang-jun; LENG Xue-song; WU Lin

    2006-01-01

    Twin-tungsten TIG welding was developed, in which two electrodes were placed in a single welding torch. In order to master this process, the arc physics characteristic was studied. The twin-tungsten coupling arc shape was observed by using CCD camera, and the arc pressure was measured. The results show that the coupling arc includes two arcs that pull each other according to Lorentz force and one big coupling arc is formed; the coupling arc pressure is much lower than that of conventional TIG arc. In the end, a simple welding experiment was carried out. This proves that stable welding process can be achieved by twin-tungsten TIG at higher current than that of conventional TIG because of its low arc pressure and the high efficiency welding is realized.

  11. Dust in the arcs of Methone and Anthe

    Science.gov (United States)

    Sun, Kai-Lung; Seiß, Martin; Hedman, M. M.; Spahn, Frank

    2017-03-01

    Methone and Anthe are two tiny moons (with diameter value in simulations is about an order of magnitude smaller. Plausible explanations for the difference include millimeter-sized particles as additional source and the uncertainties of impactor flux Fimp and the yields Y. The longitudinal extension of the Methone/Anthe arc in our simulation is 10.8°/15°, consistent with observations and theory (Hedman et al., 2009). Our results also show the lifetime distributions of particles and the heliotropic behavior of dust introduced by solar radiation pressure (Hedman et al., 2010a). The lifetimes of arc particles, defined by the time particles stay in the semi-major axes close to the source moons, are also related to particle size. Smaller ones (< 5 μm) do not stay in the arc and instead migrate outward under the influence of plasma drag. Larger grains can stay in arc in the timescale of 100 years until they leave the arcs or collide with the source moons.

  12. Generation of continental crust in intra-oceanic arcs

    Science.gov (United States)

    Gazel, E.; Hayes, J. L.; Kelemen, P. B.; Everson, E. D.; Holbrook, W. S.; Vance, E.

    2014-12-01

    The origin of continental crust is still an unsolved mystery in the evolution of our planet. Although the best candidates to produce juvenile continental crust are intra-oceanic arcs these systems are dominated by basaltic lavas, and when silicic magmas are produced, the incompatible-element compositions are generally too depleted to be a good match for continental crust estimates. Others, such as the W. Aleutians, are dominated by andesitic melts with trace element compositions similar to average continental crust. In order to evaluate which intra-oceanic arcs produced modern continental crust, we developed a geochemical continental index (CI) through a statistical analysis that compared all available data from modern intra-oceanic arcs with global estimates of continental crust. Our results suggest that magmas from Costa Rica (100 have the least continent-like geochemical signatures. In these arcs the subducting plate is old (>100 Ma), not overprinted by enriched intraplate volcanism and the geochemistry may be dominated by slab-derived, aqueous fluids. We also found a strong correlation between the CI and average crustal P-wave velocity, validating the geochemical index with the available seismic data for intra-oceanic arcs. In conclusion, the production of young continental crust with compositions similar to Archean continental crust is an unusual process, limited to locations where there are especially voluminous partial melts of oceanic crust.

  13. Non-Equilibrium Modeling of Arc Plasma Torches

    CERN Document Server

    Trelles, J P; Heberlein, J V R

    2013-01-01

    A two-temperature thermal non-equilibrium model is developed and applied to the three-dimensional and time-dependent simulation of the flow inside a DC arc plasma torch. A detailed comparison of the results of the non-equilibrium model with those of an equilibrium model is presented. The fluid and electromagnetic equations in both models are approximated numerically in a fully-coupled approach by a variational multi-scale finite element method. In contrast to the equilibrium model, the non-equilibrium model did not need a separate reattachment model to produce an arc reattachment process and to limit the magnitude of the total voltage drop and arc length. The non-equilibrium results show large non-equilibrium regions in the plasma - cold-flow interaction region and close to the anode surface. Marked differences in the arc dynamics, especially in the arc reattachment process, and in the magnitudes of the total voltage drop and outlet temperatures and velocities between the models are observed. The non-equilibr...

  14. Non-equilibrium modelling of arc plasma torches

    Energy Technology Data Exchange (ETDEWEB)

    Trelles, J P; Heberlein, J V R; Pfender, E [Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 (United States)

    2007-10-07

    A two-temperature thermal non-equilibrium model is developed and applied to the three-dimensional and time-dependent simulation of the flow inside a dc arc plasma torch. A detailed comparison of the results of the non-equilibrium model with those of an equilibrium model is presented. The fluid and electromagnetic equations in both models are approximated numerically in a fully-coupled approach by a variational multi-scale finite element method. In contrast to the equilibrium model, the non-equilibrium model did not need a separate reattachment model to produce an arc reattachment process and to limit the magnitude of the total voltage drop and arc length. The non-equilibrium results show large non-equilibrium regions in the plasma-cold-flow interaction region and close to the anode surface. Marked differences in the arc dynamics, especially in the arc reattachment process, and in the magnitudes of the total voltage drop and outlet temperatures and velocities between the models are observed. The non-equilibrium results show improved agreement with experimental observations.

  15. Modelling of the arc reattachment process in plasma torches

    Energy Technology Data Exchange (ETDEWEB)

    Trelles, J P; Pfender, E; Heberlein, J V R [Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 (United States)

    2007-09-21

    The need to improve plasma spraying processes has motivated the development of computational models capable of describing the arc dynamics inside plasma torches. Although progress has been made in the development of such models, the realistic simulation of the arc reattachment process, a central part of the arc dynamics inside plasma torches, is still an unsolved problem. This study presents a reattachment model capable of mimicking the physical reattachment process as part of a local thermodynamic equilibrium description of the plasma flow. The fluid and electromagnetic equations describing the plasma flow are solved in a fully-coupled approach by a variational multi-scale finite element method, which implicitly accounts for the multi-scale nature of the flow. The effectiveness of our modelling approach is demonstrated by simulations of a commercial plasma spraying torch operating with Ar-He under different operating conditions. The model is able to match the experimentally measured peak frequencies of the voltage signal, arc lengths and anode spot sizes, but produces voltage drops exceeding those measured. This finding, added to the apparent lack of a well-defined cold boundary layer all around the arc, points towards the importance of non-equilibrium effects inside the torch, especially in the anode attachment region.

  16. Single Arc VMAT of H&N patients

    DEFF Research Database (Denmark)

    Bertelsen, Anders; Hansen, Christian Rønn; Johansen, Jørgen;

      Background: A few planning systems are currently able to plan volumetric modulated arc therapy (VMAT). The VMAT algorithm in Pinnacle3 TM is called SmartArc. The capability of SmartArc to create complex VMAT plans for the head and neck (H&N) region was tested. Materials and Methods......) as specified by the DAHANCA recommendations. The patients were re-planned with VMAT by use of the SmartArc algorithm in Pinnacle3 TM 8.9c (research version). The collapsed cone dose engine was used for final dose calculation. One constraint for the re-planning study was to use only one single arc to create...... deliverable plans. The objectives were to achieve similar or better target coverage and sparing of the organs at risk (OAR) by VMAT compared to the IMRT plan. The VMAT plans were compared to the original IMRT plans by evaluation of 1) dose-volume histograms (DVH) of targets and organs at risk  2) monitor...

  17. CHEP2015: Dynamic Resource Allocation with arcControlTower

    CERN Document Server

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers’ workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job mangement system (Panda) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experience...

  18. Dynamic Resource Allocation with the arcControlTower

    CERN Document Server

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers’ workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job management system (PanDA) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experienc...

  19. Graphite electrode arc melter demonstration Phase 2 test results

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; O`Connor, W.K.; Oden, L.L.; Turner, P.C.

    1996-06-01

    Several U.S. Department of Energy organizations and the U.S. Bureau of Mines have been collaboratively conducting mixed waste treatment process demonstration testing on the near full-scale graphite electrode submerged arc melter system at the Bureau`s Albany (Oregon) Research Center. An initial test series successfully demonstrated arc melter capability for treating surrogate incinerator ash of buried mixed wastes with soil. The conceptual treatment process for that test series assumed that buried waste would be retrieved and incinerated, and that the incinerator ash would be vitrified in an arc melter. This report presents results from a recently completed second series of tests, undertaken to determine the ability of the arc melter system to stably process a wide range of {open_quotes}as-received{close_quotes} heterogeneous solid mixed wastes containing high levels of organics, representative of the wastes buried and stored at the Idaho National Engineering Laboratory (INEL). The Phase 2 demonstration test results indicate that an arc melter system is capable of directly processing these wastes and could enable elimination of an up-front incineration step in the conceptual treatment process.

  20. Grid Interoperation with ARC middleware for the CMS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Edelmann, Erik; Groenager, Michael; Johansson, Daniel; Kleist, Josva [Nordic DataGrid Facility, Kastruplundgade 22, 1., DK-2770 Kastrup (Denmark); Field, Laurence; Qing, Di [CERN, CH-1211 Geneve 23 (Switzerland); Frey, Jaime [University of Wisconsin-Madison, 1210 W. Dayton St., Madison, WI (United States); Happonen, Kalle; Klem, Jukka; Koivumaeki, Jesper; Linden, Tomas; Pirinen, Antti, E-mail: Jukka.Klem@cern.c [Helsinki Institute of Physics, PO Box 64, FIN-00014 University of Helsinki (Finland)

    2010-04-01

    The Compact Muon Solenoid (CMS) is one of the general purpose experiments at the CERN Large Hadron Collider (LHC). CMS computing relies on different grid infrastructures to provide computational and storage resources. The major grid middleware stacks used for CMS computing are gLite, Open Science Grid (OSG) and ARC (Advanced Resource Connector). Helsinki Institute of Physics (HIP) hosts one of the Tier-2 centers for CMS computing. CMS Tier-2 centers operate software systems for data transfers (PhEDEx), Monte Carlo production (ProdAgent) and data analysis (CRAB). In order to provide the Tier-2 services for CMS, HIP uses tools and components from both ARC and gLite grid middleware stacks. Interoperation between grid systems is a challenging problem and HIP uses two different solutions to provide the needed services. The first solution is based on gLite-ARC grid level interoperability. This allows to use ARC resources in CMS without modifying the CMS application software. The second solution is based on developing specific ARC plugins in CMS software.

  1. Water-vortex stabilized electric arc: I. Numerical model

    Science.gov (United States)

    Jenista, Jirí

    1999-11-01

    A numerical model for an electric arc stabilized by a water vortex has been proposed. The two-dimensional axisymmetric model includes the discharge area between the cathode and the orifice of the arc chamber. The production of water plasma, i.e. the rate of evaporation of a water wall, is taken either from experiments or is determined numerically by fitting of the outlet plasma parameters to the experimental ones. The computer results concern thermal, fluid dynamic and electrical characteristics of such arcs for the currents 300, 400, 500 and 600 A. It is found, for example, that the role of thermal diffusion within the discharge increases with current. The power losses from the arc due to radial conduction and radiation represent around 50% of the input power. Rotation of the plasma column due to the induced tangential velocity component has negligible effect on the overall arc performance. The calculated velocities, pressure drops and electrical potentials are in good agreement with experiments carried out on the water plasma torch PAL-160 operating at our Institute.

  2. ArcGIS和Creator各自支持的TIN之间的转换%Conversion of TIN from ArcGIS's to Creator's

    Institute of Scientific and Technical Information of China (English)

    陈真; 费立凡; 邓敏

    2006-01-01

    讨论了在ESRI公司的ArcGIS和MultiGen公司的Creator两种平台下,使用二次开发技术将ArcGIS所支持的不规则三角网(TIN)转换为Creator所支持的OpenFlight格式的方法,并且分别剖析了MultiGen Creator的OpenFlight模型和ArcGIS下的TIN模型,接着叙述了Creator提供的OpenFlight API和ArcGIS的ArcObjects组件库,并以VC++为开发平台,在Creator内重建TIN地形的具体方法.

  3. Periodontitis in Chronic Heart Failure.

    Science.gov (United States)

    Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A; Zugck, Christian; Frankenstein, Lutz

    2016-08-01

    Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P <0.00001). The severity of periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases.

  4. Feasibility of the partial-single arc technique in RapidArc planning for prostate cancer treatment

    Institute of Scientific and Technical Information of China (English)

    Suresh Rana; ChihYao Cheng

    2013-01-01

    The volumetric modulated arc therapy (VMAT) technique, in the form of RapidArc, is widely used to treat prostate cancer. The full-single arc (f-SA) technique in RapidArc planning for prostate cancer treatment provides efficient treatment, but it also delivers a higher radiation dose to the rectum. This study aimed to compare the dosimetric results from the new partial-single arc (p-SA) technique with those from the f-SA technique in RapidArc planning for prostate cancer treatment. In this study, 10 patients with low-risk prostate cancer were selected. For each patient, two sets of RapidArc plans (f-SA and p-SA) were created in the Eclipse treatment planning system. The f-SA plan was created using one ful arc, and the p-SA plan was created using planning parameters identical to those of the f-SA plan but with anterior and posterior avoidance sectors. Various dosimetric parameters of the f-SA and p-SA plans were evaluated and compared for the same target coverage and identical plan optimization parameters. The f-SA and p-SA plans showed an average difference of ±1% for the doses to the planning target volume (PTV), and there were no clear differences in dose homogeneity or plan conformity. In comparison to the f-SA technique, the p-SA technique reduced the doses to the rectum by approximately 6.1% to 21.2%, to the bladder by approximately 10.3%to 29.5%, and to the penile bulb by approximately 2.2%. In contrast, the dose to the femoral heads, the integral dose, and the number of monitor units were higher in the p-SA plans by approximately 34.4%, 7.7%, and 9.2%, respectively. In conclusion, it is feasible to use the p-SA technique for RapidArc planning for prostate cancer treatment. For the same PTV coverage and identical plan optimization parameters, the p-SA technique is better in sparing the rectum and bladder without compromising plan conformity or target homogeneity when compared to the f-SA technique.

  5. Stress fields of the overriding plate at convergent margins and beneath active volcanic arcs.

    Science.gov (United States)

    Apperson, K D

    1991-11-01

    Tectonic stress fields in the overriding plate at convergent plate margins are complex and vary on local to regional scales. Volcanic arcs are a common element of overriding plates. Stress fields in the volcanic arc region are related to deformation generated by subduction and to magma generation and ascent processes. Analysis of moment tensors of shallow and intermediate depth earthquakes in volcanic arcs indicates that the seismic strain field in the arc region of many convergent margins is subhorizontal extension oriented nearly perpendicular to the arc. A process capable of generating such a globally consistent strain field is induced asthenospheric corner flow below the arc region.

  6. Application of ArcGIS in the Interior Work of Geographical Conditions Census%ArcGIS在地理国情普查内业中的应用

    Institute of Scientific and Technical Information of China (English)

    吴盛; 高子让

    2015-01-01

    本文将ArcGIS技术与地理国情普查的内业工作结合起来,在地理国情普查内业处理中,通过对ArcGIS的Topology工具及ArcToolbox的运用,综合分析ArcGIS软件在内业数据整理的优缺点。%This article combined ArcGIS technology with the interior work of the geography conditions census. In dealing with the interior work of geography conditions census, we generally analized the advantages and disadvantages of ArcGIS software in the interior data processing by the use of the Topology tools and ArcToolbox tools of Arcgis.

  7. Pattern matching in indeterminate and Arc-annotated sequences.

    Science.gov (United States)

    Aumi, Md Tanvir Islam; Moosa, Tanaeem M; Rahman, M Sohel

    2013-08-01

    In this paper, we present efficient algorithms for finding indeterminate Arc-Annotated patterns in indeterminate Arc-Annotated references. Our algorithms run in O(m+ (nm) w) time where n and m are respectively the length of our reference and pattern strings and w is the target machine word size. Here we have assumed the alphabet size to be constant, because, indeterminate Arc-Annotated sequences are used to model biological sequences. Clearly, for short patterns, our algorithms run in linear time and efficient algorithms for matching short patterns to reference genomes have huge applications in practical settings. We have also applied our algorithms to scan the ncRNAs without pseudoknots. We scanned three whole human chromosomes and it took only 2.5 - 4 minutes to scan one whole chromosome for an ncRNA family. Some relevant patents are discussed in.

  8. Kinetic Modeling of Plasma Methane Conversion Using Gliding Arc

    Institute of Scientific and Technical Information of China (English)

    Antonius Indarto; Jae-Wook Choi; Hwaung Lee; Hyung Keun Song

    2005-01-01

    Plasma methane (CH4) conversion in gliding arc discharge was examined. The result data of experiments regarding the performance of gliding arc discharge were presented in this paper. A simulation which is consisted some chemical kinetic mechanisms has been provided to analyze and describe the plasma process. The effect of total gas flow rate and input frequency refers to power consumption have been studied to evaluate the performance of gliding arc plasma system and the reaction mechanism of decomposition.Experiment results indicated that the maximum conversion of CH4 reached 50% at the total gas flow rate of 1 L/min. The plasma reaction was occurred at the atmospheric pressure and the main products were C (solid), hydrogen, and acetylene (C2H2). The plasma reaction of methane conversion was exothermic reaction which increased the product stream temperature around 30-50 ℃.

  9. The challenge of improving electric arc furnace efficiency

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, E.H. (Tekon Services Ltd., Whitby, Ontario (Canada)); Goodwill, J.E.; Klesser, D.E. (EPRI, Pittsburgh, PA (United States). Center for Materials Production)

    1994-05-01

    Electric arc furnace requirements for electrical energy are increasing more rapidly than generation and distribution capacity. Electric arc furnace technology is reviewed with respect to energy requirements. Although the use of water-cooled panels, increased power levels and higher oxygen inputs, for example, all increase the rate of energy loss, they do not necessarily result in an increase in energy losses per ton. The increase in loss rate (energy/hour) may be more than offset by a decrease in cycle time. This article attempts to summarize the impact of various process variable discussed in a recent report on electric arc furnace efficiency issued by the Electric Power Research Institute's (EPRI) Center for Materials Production (CMP). These include meltshop logistics, operating practices, energy input, scrap preheating and pollution control.

  10. Ecton mechanism of ion flow generation in vacuum arc

    CERN Document Server

    Mesyats, G A

    2001-01-01

    The basic characteristics of cathode plasma generation in vacuum arc (ion erosion, ion average charge) were studied from the point of an ecton model of a cathode spot in vacuum arc. The estimates of ion parameters obtained for a single cell of a cathode spot show qualitative conformity with the experimental data. One introduces the following mechanism of cathode plasma generation in vacuum arc. In case of explosion-like destruction of a cathode segment under the effect of the Joule heating the cathode matter changes sequentially its state: condensed one, nonideal and ideal plasma ones. During this change one observes formation of plasma charge composition and ion acceleration under the effect of plasma pressure gradient

  11. Direct Current Electric Arc-Electroslag Ladle Furnace

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to solve the high consumption problem of small capacity ladle furnace (LF), the operation principle and control method of the DC arc and electroslag heating ladle furnace are introduced. With only one arcing electrode, the distance between the arc and the wall of ladle is enlarged, and consequently the consumption of the ladle refractory is decreased. In the invention, a signal electrode is embedded in the refractory lining of the ladle, which contacts directly with the liquid steel and the ladle shell. Two graphite anode ends are submerged in the slag layer. The signal electrode is used as voltage reference during refining process. The electroslag voltage between anode end and liquid steel is applied to control the depth of anode end in the slag layer during the refining process with this ladle furnace.

  12. Three Filtered Vacuum Arc Plasma Sources Deposition & Implantation System

    Institute of Scientific and Technical Information of China (English)

    WU Xian-ying; ZHANG Hui-xing; LI Qiang

    2004-01-01

    A deposition & implantation system, which includes three filtered vacuum arc plasma sources, has been built. Vacuum arc discharge is used to produce high-density metal plasma; Curved magnetic filtering technique is used to transfer the plasma into out-of-sight vacuum chamber and reduce macro-particles from the vacuum arc plasma in order to drastically reduce the macro-particles contamination of the films. The up to 30 kV negative bias applied to the target can be used for ion implantation in order to improve the film adhesion; or for ion sputtering to clear the substrate surface. The 0 to 300 V negative bias can be used to adjust the ion energy which forming films. The system is designed for various thin films synthesizing, such as single-layer, compound layer, multi-layer films. It's principle, components and applications are described in the literature.

  13. Numerical simulation of gas metal arc welding temperature field

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhentai; Shan Ping; Hu Shengsun; Wei Xinwei; Yang Jinglei

    2006-01-01

    The infrared camera is used to investigate the temperature field of gas metal arc welding. The results show that the temperature distribution of weld pool and adjacent area appears cone shape. A new heat source model combined by Gaussian distribution heat source of the arc and conical distribution heat source of the droplet is set up based on the experimental results,and with the combined boundary conditions, the temperature field of gas metal arc welding is simulated using finite element method. According to the comparison between the results of experiment and simulation in temperature field shows that the new combined heat source model is more accurate and effective than the Gauss heat source model.

  14. The interaction between transpolar arcs and cusp spots

    CERN Document Server

    Fear, R C; Carter, J A; Maggiolo, R

    2016-01-01

    Transpolar arcs and cusp spots are both auroral phenomena which occur when the interplanetary magnetic field is northward. Transpolar arcs are associated with magnetic reconnection in the magnetotail, which closes magnetic flux and results in a "wedge" of closed flux which remains trapped, embedded in the magnetotail lobe. The cusp spot is an indicator of lobe reconnection at the high-latitude magnetopause; in its simplest case, lobe reconnection redistributes open flux without resulting in any net change in the open flux content of the magnetosphere. We present observations of the two phenomena interacting--i.e., a transpolar arc intersecting a cusp spot during part of its lifetime. The significance of this observation is that lobe reconnection can have the effect of opening closed magnetotail flux. We argue that such events should not be rare.

  15. Note: Triggering behavior of a vacuum arc plasma source.

    Science.gov (United States)

    Lan, C H; Long, J D; Zheng, L; Dong, P; Yang, Z; Li, J; Wang, T; He, J L

    2016-08-01

    Axial symmetry of discharge is very important for application of vacuum arc plasma. It is discovered that the triggering method is a significant factor that would influence the symmetry of arc discharge at the final stable stage. Using high-speed multiframe photography, the transition processes from cathode-trigger discharge to cathode-anode discharge were observed. It is shown that the performances of the two triggering methods investigated are quite different. Arc discharge triggered by independent electric source can be stabilized at the center of anode grid, but it is difficult to achieve such good symmetry through resistance triggering. It is also found that the triggering process is highly correlated to the behavior of emitted electrons.

  16. Network expansion by adding arcs and/or nodes

    Institute of Scientific and Technical Information of China (English)

    YANG Xiaoguang; ZHANG Jianzhong

    2005-01-01

    In this paper, we consider a new network improvement model, which is to expand a network by adding new arcs and/or new nodes to satisfy the excess demand. For the new arcs and new nodes, there are constructing costs for. building these new facilities.The purpose of. our model is to minimize the total constructing cost. It is found that even if the constructing costs for all new nodes are zero or all new arcs are zero, solving the problem within an approximation ratio O(ln(|V1|+|V2|)) remains NP-hard, where V1 is the original node set, and V2 is thecandidate node set. We also present an MIP formulation for the problem and propose some heuristic ideas to solve the problem.

  17. A temperature controller board for the ARC controller

    Science.gov (United States)

    Tulloch, Simon

    2016-07-01

    A high-performance temperature controller board has been produced for the ARC Generation-3 CCD controller. It contains two 9W temperature servo loops and four temperature input channels and is fully programmable via the ARC API and OWL data acquisition program. PI-loop control is implemented in an on-board micro. Both diode and RTD sensors can be used. Control and telemetry data is sent via the ARC backplane although a USB-2 interface is also available. Further functionality includes hardware timers and high current drivers for external shutters and calibration LEDs, an LCD display, a parallel i/o port, a pressure sensor interface and an uncommitted analogue telemetry input.

  18. A highly reliable trigger for vacuum ARC plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Bernardet, H.; Godechot, X.; Jarjat, F. [SODERN, Limeil-Brevannes (France)

    1996-08-01

    The authors have developed a reliable electrical trigger and its associated circuitry to fire vacuum arc plasma or ion source. They tested different embodiments of the trigger device in order to get a highly reliable one, which is able to perform more than 1.2 x 10{sup 6} shots at 60 A and 6.5 ps pulse length. The evolution of the ion current emitted has been recorded as a function of the number of shots. They have also investigated in which direction the plasma jet is emitted : axially or radially. This device can be used to fire a vacuum arc plasma or ion source by plasma injection. It has obvious advantage to be placed outside the cathode and therefore would ease maintenance of vacuum arc devices.

  19. The complexity of finding arc-disjoint branching flows

    DEFF Research Database (Denmark)

    Bang-Jensen, J.; Havet, Frédéric; Yeo, Anders

    2016-01-01

    rooted at s. The algorithm for the later result generalizes the polynomial algorithm, due to Lovász, for deciding whether a given input digraph has two arc-disjoint out-branchings rooted at a given vertex. Finally we prove that under the so-called Exponential Time Hypothesis (ETH), for every ε(lunate)>0...... and for every k(n) with (log(n))1+ε(lunate)≤k(n)≤n2 (and for every large i we have k(n)=i for some n) there is no polynomial algorithm for deciding whether a given digraph contains two arc-disjoint branching flows from the same root so that no arc carries flow larger than n-k(n)....

  20. Innovation in electric arc furnaces scientific basis for selection

    CERN Document Server

    Toulouevski, Yuri N

    2013-01-01

    This book equips a reader with knowledge necessary for critical analysis of  innovations in electric arc furnaces and helps to select the most effective ones and for their successful implementation. The book also covers general issues related to history of development, current state and prospects of steelmaking in Electric Arc Furnaces. Therefore, it can be useful for everybody who studies metallurgy, including students of colleges and universities. The modern concepts of mechanisms of Arc Furnace processes are are discussed in the book at the level sufficient to solve practical problems: To help readers lacking knowledge required in the field of heat transfer as well as hydro-gas dynamics, it contains several chapters which provide the required minimum of information in these fields of science. In order to better assess different innovations, the book describes experience of the application of similar innovations in open-hearth furnaces and oxygen converters. Some promising ideas on key issues regarding int...

  1. Zidovudine treatment of AIDS and ARC in Denmark 1987

    DEFF Research Database (Denmark)

    Teglbjærg, Lars Stubbe; Mathiesen, L R; Søeberg, B;

    1989-01-01

    In 1987, a total of 138 Danish patients (94 AIDS and 44 ARC) received treatment with zidovudine, a total observation period of 572 treatment months. 15 AIDS and 1 ARC patient died after a median of 70 days (range 2-295). In the ARC group 4 patients developed AIDS (3 Pneumocystis carinii pneumonia......, 1 Kaposi's sarcoma). Among the AIDS patients 38 new opportunistic infections were reported. 24 of these opportunistic infections occurred within 6 weeks after treatment initiation. 79 patients were observed for more than 3 months, 25 of these had their daily dose zidovudine reduced, usually from 1...... on 94 occasions and 19 (14%) patients required multiple transfusions. The mortality among the AIDS patients was significantly lower compared to historical controls. In our experience zidovudine treatment is reasonably well tolerated and the side effects are manageable....

  2. Geometric model of robotic arc welding for automatic programming

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Geometric information is important for automatic programming of arc welding robot. Complete geometric models of robotic arc welding are established in this paper. In the geometric model of weld seam, an equation with seam length as its parameter is introduced to represent any weld seam. The method to determine discrete programming points on a weld seam is presented. In the geometric model of weld workpiece, three class primitives and CSG tree are used to describe weld workpiece. Detailed data structure is presented. In pose transformation of torch, world frame, torch frame and active frame are defined, and transformation between frames is presented. Based on these geometric models, an automatic programming software package for robotic arc welding, RAWCAD, is developed. Experiments show that the geometric models are practical and reliable.

  3. Zidovudine treatment of AIDS and ARC in Denmark 1987

    DEFF Research Database (Denmark)

    Teglbjaerg, L L; Mathiesen, Lars Reinhardt; Søeberg, B;

    1989-01-01

    ,200 mg to 600 mg, 9 others were temporarily off drug. HIV antigen was analyzed in serum samples from 93 patients. Of these, 28 (52%) of 54 initially HIV antigen-positive became antigen-negative, 7 (18%) of 39 initially HIV antigen-negative became antigen-positive within the first 8 weeks of zidovudine......In 1987, a total of 138 Danish patients (94 AIDS and 44 ARC) received treatment with zidovudine, a total observation period of 572 treatment months. 15 AIDS and 1 ARC patient died after a median of 70 days (range 2-295). In the ARC group 4 patients developed AIDS (3 Pneumocystis carinii pneumonia......, 1 Kaposi's sarcoma). Among the AIDS patients 38 new opportunistic infections were reported. 24 of these opportunistic infections occurred within 6 weeks after treatment initiation. 79 patients were observed for more than 3 months, 25 of these had their daily dose zidovudine reduced, usually from 1...

  4. Enhancing stability of industrial turbines using adjustable partial arc bearings

    Science.gov (United States)

    Chasalevris, Athanasios; Dohnal, Fadi

    2016-09-01

    The paper presents the principal of operation, the simulation and the characteristics of two partial-arc journal bearings of variable geometry and adjustable/controllable stiffness and damping properties. The proposed journals are supposed to consist of a scheme that enables the periodical variation of bearing properties. Recent achievements of suppressing rotor vibrations using plain circular journal bearings of variable geometry motivate the further extension of the principle to bearings of applicable geometry for industrial turbines. The paper describes the application of a partial-arc journal bearing to enhance stability of high speed industrial turbines. The proposed partial-arc bearings with adjustable/controllable properties enhance stability and they introduce stable margins in speeds much higher than the 1st critical.

  5. PNNL 331 Building Arc Flash Team Investigation Report

    Energy Technology Data Exchange (ETDEWEB)

    Deichman, Mark L.; Drewrey, John C.; Hodges, Hurtis; Madson, Vernon J.; Minton, Allen L.; Montgomery, Daniel M.; Olson, Marvin E.; Rojas, Pedro H.; Sanan, Sanjay K.; Sharp, Reed D.; Sparks, Bobby R.; Swearingen, Gary L.

    2006-06-06

    On Friday, April 21, 2006, a PNNL electrician was performing repair of an electrical system for the 331 Building chilled water pump (CHWP) No.2, when an electrical arc flash occurred inside a 480V combination motor starter. The electrician was taken to the on-site medical provider for evaluation and was released for return to work without restriction. The electrician was not shocked, but did receive a minor, superficial (first degree) burn on the left wrist. This report, the result of a thorough review by the 331 Building Arc Flash Assessment Team, provides an in-depth look at the steps leading up to the arc-flash and recommendations and opportunities for improvement.

  6. Provenance of the Walash-Naopurdan back-arc-arc clastic sequences in the Iraqi Zagros Suture Zone

    Science.gov (United States)

    Ali, Sarmad A.; Sleabi, Rajaa S.; Talabani, Mohammad J. A.; Jones, Brian G.

    2017-01-01

    Marine clastic rocks occurring in the Walash and Naopurdan Groups in the Hasanbag and Qalander areas, Kurdistan region, Iraqi Zagros Suture Zone, are lithic arenites with high proportions of volcanic rock fragments. Geochemical classification of the Eocene Walash and Oligocene Naopurdan clastic rocks indicates that they were mainly derived from associated sub-alkaline basalt and andesitic basalt in back-arc and island arc tectonic settings. Major and trace element geochemical data reveal that the Naopurdan samples are chemically less mature than the Walash samples and both were subjected to moderate weathering. The seaway in the southern Neotethys Ocean was shallow during both Eocene and Oligocene permitting mixing of sediment from the volcanic arcs with sediment derived from the Arabian continental margin. The Walash and Naopurdan clastic rocks enhance an earlier tectonic model of the Zagros Suture Zone with their deposition occurring during the Eocene Walash calc-alkaline back-arc magmatism and Early Oligocene Naopurdan island arc magmatism in the final stages of intra-oceanic subduction before the Miocene closure and obduction of the Neotethys basin.

  7. Cardiomyocytic apoptosis and heart failure

    Institute of Scientific and Technical Information of China (English)

    Quanzhou Feng

    2008-01-01

    Heart failure is a major disease seriously threatening human health.Once left ventricular dysfunction develops,cardiac function usually deteriorates and progresses to congestive heart failure in several months or years even if no factors which accelerate the deterioration repeatedly exist.Mechanism through which cardiac function continually deteriorates is still unclear.Cardiomyocytic apoptosis can occur in acute stage of ischemic heart diseases and the compensated stage of cardiac dysfunction.In this review,we summarize recent advances in understanding the role of cardiomyocytic apoptosis in heart failure.

  8. [Baroreflex failure after chemodectoma resection].

    Science.gov (United States)

    Gómez Esteban, J C; Boyero, S; Fernández, C; Sagasta, A; Pérez, T; Velasco, F; Allue, I; Lezcano, E; Zarranz, J J

    2004-10-01

    Baroreflex failure after chemodectoma resection We present a case of baroreflex failure secondary to a unilateral injury of the glossopharyngeal nerve. The patient was operated for a left-sided chemodectoma in the carotid body. Some months after surgery she started to report presyncopal episodes exacerbated by mental stress and when standing up. During these episodes, the patient presented hypertensive crises and tachycardia. However, blood pressure was below normal ranges at rest. The diagnosis was baroreflex failure secondary to unilateral injury of the glossopharyngeal nerve. The case reported herein illustrates the fact that the presence of a bilateral injury is not essential for the occurrence of this disorder.

  9. Wind Turbine Failures - Tackling current Problems in Failure Data Analysis

    Science.gov (United States)

    Reder, M. D.; Gonzalez, E.; Melero, J. J.

    2016-09-01

    The wind industry has been growing significantly over the past decades, resulting in a remarkable increase in installed wind power capacity. Turbine technologies are rapidly evolving in terms of complexity and size, and there is an urgent need for cost effective operation and maintenance (O&M) strategies. Especially unplanned downtime represents one of the main cost drivers of a modern wind farm. Here, reliability and failure prediction models can enable operators to apply preventive O&M strategies rather than corrective actions. In order to develop these models, the failure rates and downtimes of wind turbine (WT) components have to be understood profoundly. This paper is focused on tackling three of the main issues related to WT failure analyses. These are, the non-uniform data treatment, the scarcity of available failure analyses, and the lack of investigation on alternative data sources. For this, a modernised form of an existing WT taxonomy is introduced. Additionally, an extensive analysis of historical failure and downtime data of more than 4300 turbines is presented. Finally, the possibilities to encounter the lack of available failure data by complementing historical databases with Supervisory Control and Data Acquisition (SCADA) alarms are evaluated.

  10. Electromagnetic Characteristic of Twin-wire Indirect Arc Welding

    Institute of Scientific and Technical Information of China (English)

    SHI Chuanwei; ZOU Yong; ZOU Zengda; WU Dongting

    2015-01-01

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

  11. Investigation on the arc light spectrum in GTA welding

    Directory of Open Access Journals (Sweden)

    M.S. Węglowski

    2007-01-01

    Full Text Available Purpose: In the paper there are presented results of the influence of welding parameters on spectral intensity ofthe welding arc in the range of 340÷860 nm. The main goal was checking whether the visible radiation of thearc provides information which might prove to be useful in monitoring of the welding process, similarly as thesignals recorded in the electric circuit of the welding arc.Design/methodology/approach: The experimental station was designed and build. A spectrophotometer, in thevisible spectral range of 340 nm to 860 nm, was used. The investigations were conducted on the automated GTAwelding station. For each welding parameter the arc light spectrum was measuredFindings: Research results presented in this paper indicate that the welding arc radiation contains a number ofinformation concerning the course of the welding process. That signal is much more sensitive to the changes ofwelding conditions and should be used as a tool for monitoring of the TIG welding processResearch limitations/implications: The fiber spectrophotometer in the visible spectral range of 340 nm to860 nm is an expensive instrument and that fore it can be used only as a complementary tool in monitoring ofwelding processes.Practical implications: The gained experience allows directing farther research on the welding arc radiationphenomenon and the possibilities of using this signal for on-line monitoring of the welding process onautomated and robotized stands.This sensing system will be particularly attractive for welded structures manufacturing industry because it couldsignificantly reduce the cost for post weld analysis and repairsOriginality/value: Three fitting functions: Lorentz, Gauss and Voight were investigated as a means to simulatethe spectrum distribution. The mathematical-physical model of the arc light emission and neural networkswere compared

  12. Thermocapillary and arc phenomena in stainless steel welds

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, S.W.

    1993-10-01

    Goal was to study effect of power level and distribution on thermocapiilary-induced weld shape and of arc factors on weld shape. Thermocapillarity was apparent in both conduction mode EB welds and GTA welds, particularly in the former. A non-Gaussian arc distribution is suggested for accounting for the differences between the twoss processes. At higher current levels (200--300 A), plasma shear force also contributes to weld shape development. Evidence suggests that thermocapillary flow reversal is not a factor in normal GTA welds; EDB flow reversal occurs only at high power density levels where the keyhole mode is present.

  13. Composition Gradient Hard Coatings by Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    CHENJun; LINGuo-qiang; WANGFu-gang

    2004-01-01

    Arc Ion Plating can be used to synthesize multi-component composition gradient hard coatings by adjusting arc currents of metal targets. The present work aims at a comprehensive description of such a technique. The examples of TiAl multi-layer alloy coatings and (Ti,M) N composition-gradient films were taken (M representing Zr, Nb etc.) for the purpose of explaining the working process and evaluating practical effects. The results show that this technique has the advantages of easy manipulation, rapid deposition, and wide composition range.

  14. The time-dependent prize-collecting arc routing problem

    DEFF Research Database (Denmark)

    Black, Dan; Eglese, Richard; Wøhlk, Sanne

    2013-01-01

    A new problem is introduced named the Time-Dependent Prize-Collecting Arc Routing Problem (TD-PARP). It is particularly relevant to situations where a transport manager has to choose between a number of full truck load pick-ups and deliveries on a road network where travel times change with the t......A new problem is introduced named the Time-Dependent Prize-Collecting Arc Routing Problem (TD-PARP). It is particularly relevant to situations where a transport manager has to choose between a number of full truck load pick-ups and deliveries on a road network where travel times change...

  15. Fatigue life prediction of crankshaft repaired by twin arc spraying

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo-qing; WANG Cheng-tao; PU Geng-qiang

    2005-01-01

    This paper used Baumel Jr. and Seeger's approach estimating fatigue parameters of 48MnV with 3Cr13coatings. The fatigue life of the crankshaft of a six-cylinder engine, repaired by twin arc spraying 3cr13 deposits, is respectively calculated using different damage model such as S-N method, normal strain approaches, SWT-Bannantine approaches, shear strain approaches, and fatemi-Socie method based on dynamical simulation and FE analysis of crankshaft. The results indicate that the traditional calculation is conservative and that the life of crankshaft repaired by arc spraying is sufficient.

  16. Plural voltage minima in an arc-heated channel flow

    Science.gov (United States)

    Sasoh, A.

    2001-04-01

    In flows through a channel with varying cross-sectional area, the impulse and total enthalpy can be increased by superimposing an electrical discharge. The flow field is determined from the inlet flow condition, channel geometry, and discharge specifications. In this study, steady-state, quasi-one-dimensional flows interacting with an arc discharge are computed numerically. Once the arc column configuration is given, the discharge voltage is computed from the solution of flow field variables. For a constant discharge current, there exist plural column configurations which yield a minimum discharge voltage. This result explains the fluid-dynamic mechanisms of the existence of plural voltage modes in an arcjet operation.

  17. U-series Disequilibria in Continental Arcs: NE Japan Case

    Science.gov (United States)

    Tepley, F. J.; Gill, J. B.; Williams, R. W.

    2005-12-01

    Basalts and andesites from continental arcs typically are close to equilibrium between (238U) and (230Th), and have subdued excesses of 226Ra compared to oceanic arcs (Turner et al., 2003). There is ambiguity whether these and other geochemical features derive from subducted sediment, subcontinental lithosphere, or the crust. We report new 238U-234U-230Th-226Ra data for 20 historical to Holocene samples from Asama in the south of NE Japan to Tarumai in the north. Most straddle the equiline with 4.

  18. Adaptive Memory Procedure to solve the Profitable Arc Tour Problem

    Directory of Open Access Journals (Sweden)

    Jalel Euchi

    2010-05-01

    Full Text Available In this paper we propose an Adaptive memory procedure to solve the Profitable Arc Tour Problem (PATP. The PATP is a variant of the well-known Vehicle Routing Problems in which a set of vehicle tours are constructed. The objective is to find a set of cycles in the vehicle tours that maximize the collection of profits minus travel costs, subject to constraints limiting the length of cycles that profit is available on arcs. Computational experiments show that our algorithms provide good results in terms of quality of solution and running times.

  19. Unique variable polarity plasma arc welding for space shuttle

    Science.gov (United States)

    Schwinghamer, R. J.

    1985-01-01

    Since the introduction of the Plasma Arc Torch in 1955 and subsequent to the work at Boeing in the 1960's, significant improvements crucial to success have been made in the Variable Polarity Plasma Arc (VPPA) Process at the Marshall Space Flight Center. Several very important advantages to this process are given, and the genesis of PA welding, the genesis of VPPA welding, special equiment requirements, weld property development, results with other aluminum alloys, and the eventual successful VPPA transition to production operations are discussed.

  20. Control of arc plasma torches: compensation of operational enthalpy drifts

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, D H; Alexieva, J; Djakov, B E; Enikov, R [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Dimitrov, D [Centre of Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 105, 1113 Sofia (Bulgaria)], E-mail: dick.oliver@gmail.com

    2008-05-01

    In arc plasma torches electrode wear is the main reason for slow changes in the electrical and thermal torch characteristics. Such effects hinder technological applications of this type of plasma torches whenever the enthalpy must be maintained at a fixed level, or varied as needed. To solve this problem, a new method and algorithm for torch control are proposed. The time evolution of the arc current, voltage and thermal power loss of the torch are recorded. The values measured are used to find the required value of the enthalpy.

  1. Heart Failure: Unique to Older Adults

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z Heart Failure Unique to Older Adults This section provides information ... or maintain quality of life. Urinary Incontinence and Heart Failure If you have heart failure, you may experience ...

  2. Planning Ahead: Advanced Heart Failure

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Planning Ahead: Advanced Heart Failure Updated:Sep 30,2016 ... making your preferences known is called advance care planning. It allows you to speak for yourself, even ...

  3. Decongestion in acute heart failure

    NARCIS (Netherlands)

    Mentz, Robert J.; Kjeldsen, Keld; Rossi, Gian Paolo; Voors, Adriaan A.; Cleland, John G. F.; Anker, Stefan D.; Gheorghiade, Mihai; Fiuzat, Mona; Rossignol, Patrick; Zannad, Faiez; Pitt, Bertram; O'Connor, Christopher; Felker, G. Michael

    2014-01-01

    Congestion is a major reason for hospitalization in acute heart failure (HF). Therapeutic strategies to manage congestion include diuretics, vasodilators, ultrafiltration, vasopressin antagonists, mineralocorticoid receptor antagonists, and potentially also novel therapies such as gut sequesterants

  4. Predicting Failures in Power Grids

    CERN Document Server

    Chertkov, Michael; Stepanov, Mikhail G

    2010-01-01

    Here we develop an approach to predict power grid weak points, and specifically to efficiently identify the most probable failure modes in load distribution for a given power network. This approach is applied to two examples: Guam's power system and also the IEEE RTS-96 system, both modeled within the static Direct Current power flow model. Our algorithm is a power network adaption of the worst configuration heuristics, originally developed to study low probability events in physics and failures in error-correction. One finding is that, if the normal operational mode of the grid is sufficiently healthy, the failure modes, also called instantons, are sufficiently sparse, i.e. the failures are caused by load fluctuations at only a few buses. The technique is useful for discovering weak links which are saturated at the instantons. It can also identify overutilized and underutilized generators, thus providing predictive capability for improving the reliability of any power network.

  5. Severe Obesity and Heart Failure

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_161011.html Severe Obesity and Heart Failure Study sees link even without ... 2016 FRIDAY, Sept. 16, 2016 (HealthDay News) -- Severe obesity appears to be an independent risk factor for ...

  6. Bisoprolol for congestive heart failure

    DEFF Research Database (Denmark)

    Rosenberg, J.; Gustafsson, F.

    2008-01-01

    . Methods: Using the keywords 'bisoprolol' and 'heart failure' PubMed and BIOSIS databases were searched for information regarding pharmacology and relevant randomised clinical trials. Supplementary publications were acquired by scrutinising reference lists of relevant papers. Additional information...

  7. Creep-Fatigue Failure Diagnosis

    Directory of Open Access Journals (Sweden)

    Stuart Holdsworth

    2015-11-01

    Full Text Available Failure diagnosis invariably involves consideration of both associated material condition and the results of a mechanical analysis of prior operating history. This Review focuses on these aspects with particular reference to creep-fatigue failure diagnosis. Creep-fatigue cracking can be due to a spectrum of loading conditions ranging from pure cyclic to mainly steady loading with infrequent off-load transients. These require a range of mechanical analysis approaches, a number of which are reviewed. The microstructural information revealing material condition can vary with alloy class. In practice, the detail of the consequent cracking mechanism(s can be camouflaged by oxidation at high temperatures, although the presence of oxide on fracture surfaces can be used to date events leading to failure. Routine laboratory specimen post-test examination is strongly recommended to characterise the detail of deformation and damage accumulation under known and well-controlled loading conditions to improve the effectiveness and efficiency of failure diagnosis.

  8. Your Heart Failure Healthcare Team

    Science.gov (United States)

    ... them know how you're doing. With good teamwork and communication, you can improve the quality of ... Failure Recognition and Knowing Your Options Planning Ahead Communicating with Your Healthcare Provider Overcoming Barriers to Shared ...

  9. Along-arc geochemical and isotopic variations in Javanese volcanic rocks: 'crustal' versus 'source' contamination at the Sunda arc, Indonesia

    Science.gov (United States)

    Handley, H.; Blichert-Toft, J.; Turner, S.; Macpherson, C. G.

    2012-12-01

    Understanding the genesis of volcanic rocks in subduction zone settings is complicated by the multitude of differentiation processes and source components that exert control on lava geochemistry. Magma genesis and evolution at the Sunda arc is controlled and influenced by 1) along arc changes in the composition and thickness of the overriding Eurasian plate, 2) the variable age of the subducting oceanic crust and, 3) changes in the type and amount of sediment deposited on the subducting plate. Along-arc changes in geochemistry have long been recognised in the Sunda arc (Whitford, 1975), but debate still prevails over the cause of such variations and the relative importance of shallow (crustal) versus deep (subduction) contamination at the Sunda arc, Indonesia. Detailed study of individual Sunda arc volcanic centres is, therefore, a prerequisite in order to establish the relative importance and contributions of various potential source components and composition modifying differentiation processes at individual volcanoes, prior to an along arc comparative petrogenetic investigation. We present new radiogenic isotope data for Javanese volcanoes, which is combined with our recently published (Handley et al., 2007; Handley et al., 2008, Handley et al., 2010; Handley et al., 2011) geochemical and isotopic data of Javanese volcanic rocks along with data from other detailed geochemical studies to establish whether variable contributions from the subducting slab, or a change in crustal architecture of the overriding plate, best explain along-arc variations in isotope ratios and trace element characteristics. In West and Central Java Sr isotope ratios of the volcanic rocks broadly correlate with inferred lithospheric thickness implicating a shallow level control on isotopic composition. However, key trace element ratios combined with Hf isotope data indicate that the subducted slab and slab thermal regime also exert major control on the composition of the erupted Javanese

  10. High energy arcing fault fires in switchgear equipment : a literature review.

    Energy Technology Data Exchange (ETDEWEB)

    Nowlen, Steven Patrick; Brown, Jason W.; Wyant, Francis John

    2008-10-01

    In power generating plants, switchgear provide a means to isolate and de-energize specific electrical components and buses in order to clear downstream faults, perform routine maintenance, and replace necessary electrical equipment. These protective devices may be categorized by the insulating medium, such as air or oil, and are typically specified by voltage classes, i.e. low, medium, and high voltage. Given their high energy content, catastrophic failure of switchgear by means of a high energy arcing fault (HEAF) may occur. An incident such as this may lead to an explosion and fire within the switchgear, directly impact adjacent components, and possibly render dependent electrical equipment inoperable. Historically, HEAF events have been poorly documented and discussed in little detail. Recent incidents involving switchgear components at nuclear power plants, however, were scrupulously investigated. The phenomena itself is only understood on a very elementary level from preliminary experiments and theories; though many have argued that these early experiments were inaccurate due to primitive instrumentation or poorly justified methodologies and thus require re-evaluation. Within the past two decades, however, there has been a resurgence of research that analyzes previous work and modern technology. Developing a greater understanding of the HEAF phenomena, in particular the affects on switchgear equipment and other associated switching components, would allow power generating industries to minimize and possibly prevent future occurrences, thereby reducing costs associated with repair and downtime. This report presents the findings of a literature review focused on arc fault studies for electrical switching equipment. The specific objective of this review was to assess the availability of the types of information needed to support development of improved treatment methods in fire Probabilistic Risk Assessment (PRA) for nuclear power plant applications.

  11. [Does diastolic heart failure exist?].

    Science.gov (United States)

    Guadalajara Boo, José Fernando

    2003-01-01

    This paper reviews the concepts of systolic function, diastolic function, heart failure, diastolic dysfunction, and diastolic heart failure. We refer to the historic evolution of the concept of heart failure and the origin of the term diastolic heart failure. Based on the current concepts of the physiology of the heart and its pathophysiology, we discuss the inappropriateness of the term and to the confusion it has generated in clinical practice, treatment, and prognosis, as well as in numerous research papers (of which some examples are given) when terming as "heart failure" the diastolic dysfunction and using both terms indistinctively. We conclude that an increasing need has arisen, ever more imperative, to identify clearly the concepts of heart failure and diastolic dysfunction, emphasizing on their differences to recognize them as distinct clinical entities with their own personality and, hence, having different prognosis and treatment. This would be of great help to achieve more accuracy in the clinical guidelines, standards, and consensus, especially regarding treatment. Besides it would be useful to avoid, inconsistencies in the design of research, which appear in some of the publications just by the lack of a clear meaning of the terms. Finally, at present we have the necessary elements to conclude that the terms "diastolic heart failure" and "cardiac failure with preserved systolic function" are inexact, poorly gauged, and far away from the actual problem they try to define. Therefore, they should be substituted by the concept of Diastolic Dysfunction, which defines clearly the pathophysiology of the functional alteration, without having to state that "the heart is failing".

  12. The failure-tolerant leader.

    Science.gov (United States)

    Farson, Richard; Keyes, Ralph

    2002-08-01

    "The fastest way to succeed," IBM's Thomas Watson, Sr., once said, "is to double your failure rate." In recent years, more and more executives have embraced Watson's point of view, coming to understand what innovators have always known: Failure is a prerequisite to invention. But while companies may grasp the value of making mistakes at the level of corporate practices, they have a harder time accepting the idea at the personal level. People are afraid to fail, and corporate culture reinforces that fear. In this article, psychologist and former Harvard Business School professor Richard Farson and coauthor Ralph Keyes discuss how companies can reduce the fear of miscues. What's crucial is the presence of failure-tolerant leaders--executives who, through their words and actions, help employees overcome their anxieties about making mistakes and, in the process, create a culture of intelligent risk-taking that leads to sustained innovation. Such leaders don't just accept productive failure, they promote it. Drawing from their research in business, politics, sports, and science, the authors identify common practices among failure-tolerant leaders. These leaders break down the social and bureaucratic barriers that separate them from their followers. They engage at a personal level with the people they lead. They avoid giving either praise or criticism, preferring to take a nonjudgmental, analytical posture as they interact with staff. They openly admit their own mistakes rather than trying to cover them up or shifting the blame. And they try to root out the destructive competitiveness built into most organizations. Above all else, failure-tolerant leaders push people to see beyond traditional definitions of success and failure. They know that as long as a person views failure as the opposite of success, rather than its complement, he or she will never be able to take the risks necessary for innovation.

  13. Reassessing guidelines for heart failure

    Directory of Open Access Journals (Sweden)

    Helmut Drexler

    2004-03-01

    Full Text Available Significant progress has been made in the last few years in the management of heart failure. In particular several trials have given significant results. It has become apparent that heart failure may be prevented in some patients by treatment of risk factors such as coronary artery disease. Experience with angiotensin-converting enzyme (ACE inhibitors has shown that the survival and symptomatic benefits do last in the long term, and confirm that they are the first-line treatment in heart failure. The results of a number of trials using the angiotensin receptor blockers (ARBs candesartan, valsartan and losartan are presented and discussed. There is also some experience now in the use of candesartan for patients with heart failure and preserved left ventricular systolic function. The COMET trial compared the β-blockers carvedilol and metoprolol tartrate, and suggests that there may be differences in clinical effect between β-blockers. The selective aldosterone receptor blocker eplerenone was evaluated in the EPHESUS trial in post-MI patients with signs of heart failure. Based on these clinical trials, heart failure guidelines are now being updated.

  14. RapidArc radiotherapy planning for prostate cancer: Single-arc and double-arc techniques vs. intensity-modulated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sze, Henry C.K., E-mail: szeck@ha.org.hk [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong (Hong Kong); Lee, Michael C.H.; Hung, Wai-Man; Yau, Tsz-Kok; Lee, Anne W.M. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong (Hong Kong)

    2012-04-01

    RapidArc is a novel technique using arc radiotherapy aiming to achieve intensity-modulated radiotherapy (IMRT)-quality radiotherapy plans with shorter treatment time. This study compared the dosimetric quality and treatment efficiency of single-arc (SA) vs. double-arc (DA) and IMRT in the treatment of prostate cancer. Fourteen patients were included in the analysis. The planning target volume (PTV), which contained the prostate gland and proximal seminal vesicles, received 76 Gy in 38 fractions. Seven-field IMRT, SA, and DA plans were generated for each patient. Dosimetric quality in terms of the minimum PTV dose, PTV hotspot, inhomogeneity, and conformity index; and sparing of rectum, bladder, and femoral heads as measured by V70, V-40, and V20 (% of volume receiving >70 Gy, 40 Gy, and 20 Gy, respectively), treatment efficiency as assessed by monitor units (MU) and treatment time were compared. All plan objectives were met satisfactorily by all techniques. DA achieved the best dosimetric quality with the highest minimum PTV dose, lowest hotspot, and the best homogeneity and conformity. It was also more efficient than IMRT. SA achieved the highest treatment efficiency with the lowest MU and shortest treatment time. The mean treatment time for a 2-Gy fraction was 4.80 min, 2.78 min, and 1.30 min for IMRT, DA, and SA, respectively. However, SA also resulted in the highest rectal dose. DA could improve target volume coverage and reduce treatment time and MU while maintaining equivalent normal tissue sparing when compared with IMRT. SA achieved the greatest treatment efficiency but with the highest rectal dose, which was nonetheless within tolerable limits. For busy units with high patient throughput, SA could be an acceptable option.

  15. Arc arrays: studies of high resolution techniques for multibeam bathymetric applications

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Schenke, H.W.

    In this paper a theoretical study is initiated to observe the utility of directional spectral estimation techniques for `arc array' geometries. We examine the suitability of a 15 degrees arc transducer geometry for multibeam bathymetric applications...

  16. Associations among genotype, clinical phenotype, and intracellular localization of trafficking proteins in ARC syndrome

    NARCIS (Netherlands)

    Smith, Holly; Galmes, Romain; Gogolina, Ekaterina; Straatman-Iwanowska, Anna; Reay, Kim; Banushi, Blerida; Bruce, Christopher K.; Cullinane, Andrew R.; Romero, Rene; Chang, Richard; Ackermann, Oanez; Baumann, Clarisse; Cangul, Hakan; Celik, Fatma Cakmak; Aygun, Canan; Coward, Richard; Dionisi-Vici, Carlo; Sibbles, Barbara; Inward, Carol; Kim, Chong Ae; Klumperman, Judith; Knisely, A. S.; Watson, Steven P.; Gissen, Paul

    2012-01-01

    Arthrogryposisrenal dysfunctioncholestasis (ARC) syndrome is a rare autosomal recessive multisystem disorder caused by mutations in vacuolar protein sorting 33 homologue B (VPS33B) and VPS33B interacting protein, apicalbasolateral polarity regulator (VIPAR). Cardinal features of ARC include congenit

  17. A comparative study of modelling AC electric arc by one-dimensional interpolation for power system harmonics analysis

    OpenAIRE

    Liu Yu-Jen; Hung Jen-Pan; Chen Shang-I; Lin Cheng-Wei

    2016-01-01

    Electric arc is a discharge phenomenon caused by particular electrical events and arc produced facilities in power system, for example the occurrence of short-circuit fault in feeders and the use of electric arc furnace for steel-making. All of these electric arcs have a highly nonlinear nature and can be considered as a significant source of power quality problems. To investigate the impacts of the electric arcs on power quality studies the development of the electric arc models for simulati...

  18. A New Waste Disposal Technology-plasma arc Pyrolysis System

    Institute of Scientific and Technical Information of China (English)

    黄建军; 施嘉标; 梁荣庆; 刘正之

    2003-01-01

    This paper introduces a new waste disposal technology with plasma arc. Being different from conventional combustion or burning such as incineration, it is based on a process called controlled pyrolysis-thermal destruction and recovery process. It has four advantages, they are completely safe, clean, high-energy synthesis gas, non-toxic vitrified slag and metal.

  19. Hypergravity synthesis of graphitic carbon nanomaterial in glide arc plasma

    NARCIS (Netherlands)

    J. Šperka; P. Soucek; J.J.W.A. van Loon; A. Dowson; C. Schwarz; J. Krause; Y. Butenko; G. Kroesen; V. Kudrle

    2014-01-01

    A nanostructured carbon material was synthesized using a methane/helium glide arc plasma under standard and increased gravity. Material analysis performed on samples collected from an effluent gas filter showed that the deposited material was present in the form of carbon nanoparticles. They exhibit

  20. OPERATION OF THE ELECTRIC ARC FURNACE WITH LIQUID RESIDUES METAL

    Directory of Open Access Journals (Sweden)

    A. B. Steblov

    2016-01-01

    Full Text Available Investigations have shown a positive impact of increasing the mass of the liquid residue (swamps in an electric arc furnace EAF-160, from 10 to 20–30 tonnes on increasing of usable output and reducing the specific energy consumption per ton of liquid metal.