WorldWideScience

Sample records for plate stability experiments

  1. Stability of plate structures

    DEFF Research Database (Denmark)

    Hansen, Klaus; Hansen, Klavs Feilberg

    Danish concrete panel building systems have aroused considerable interest in many other countries. The present book, which is a translation of an SBI Direction, deals with various methods applied by Danish engineers in the design of shear wall buildings. In addition information is given...... on the carrying capacity of concrete components and joints, based on experiments carried out in Denmark and other countries. Reference is also made to international recommendations on the design of shear wall buildings....

  2. Plate shell structures - statics and stability

    DEFF Research Database (Denmark)

    Almegaard, Henrik

    2008-01-01

    This paper describes the basic structural system, statics and spatial stability of plate shells. The structural system can be considered as a single layer of planar elements, where each element only transfers in-plane (membrane) forces to its neighbouring elements. External out-of-plane loads...... are carried into the structure as in-plane forces by plate action in each element. These in-plane forces are then carried through the plate structure to the supports as in-plane forces by membrane action. The consequence is that the spatial stability of the structure can be simply analysed by considering...... the plate system as only subject to in-plane loads. The stability of such systems is based on the fact that each plane element is held fixed in space by three fixed support lines and that these support lines can be provided by three plane neighbour elements. This means that the spatial stability of a plate...

  3. Stability Problems for Plates with Short-Term Damageability

    Science.gov (United States)

    Khoroshun, L. P.; Babich, D. V.

    2001-02-01

    The problem on stability of plates with microdamages simulated by hollow randomly dispersed micropores is considered. Two approaches are proposed to investigate the stability of plates weakened by microdamages. These approaches are based on models well known from the theory of stability of elastoplastic bodies — the concepts of tangent-modulus loading and continuous loading

  4. Stability of Propofol in Polystyrene-Based Tissue Culture Plates

    Science.gov (United States)

    Sall, Jeffrey W.; Leong, Jason

    2013-01-01

    Propofol has been reported to have high stability in glass and relatively high stability up to 24 hours in polyvinyl chloride-based medical plastics. Recent publications have observed the effects of propofol on cells and tissues grown in culture. Many cell culture plastics are formulated from polystyrene but we could find little information on the stability of propofol exposed to these products. We observed very little change in the concentration of propofol diluted in cell culture medium over 24 hours when exposed to glass, but substantial loss of the drug when exposed to 96-well polystyrene cell culture plates. This decrease was most rapid in the first hour but continued until 24 hours. The type of plastic used in cell and tissue culture experiments with propofol may influence the results by increasing the apparent dose required to see an effect. PMID:23632056

  5. Stability of Three-Layered Annular Plate with Composite Facings

    Science.gov (United States)

    Pawlus, D.

    2017-02-01

    Paper presents the behaviour of three-layered annular plates subjected to loads acting in plate plane. Plates are composed of laminated fibre-reinforced composite facings and foam core. The static and dynamic parameters of plate critical state were evaluated. The sensitivity of composite structure of plate to the acting of quickly increasing in time loads is shown. The problem has been solved numerically using the finite element method. Results have been compared with ones obtained for plate models with isotropic layers. These plate models have also been calculated solving formulated task analytically and numerically by means of the finite difference method. Solutions to the problem concern the axisymmetrical and asymmetrical plate buckling modes. Numerous presented tables and figures create the image of the stability behaviour of examined composite plates.

  6. Anterior cervical fusion and Caspar plate stabilization for cervical trauma.

    Science.gov (United States)

    Caspar, W; Barbier, D D; Klara, P M

    1989-10-01

    A technique for anterior cervical iliac graft fusion with standardized, commercially available screw and plate fixation (Caspar plating) has been developed. The step-by-step procedure, as well as the instruments designed to facilitate the procedure, are described in this report. Sixty cases of cervical trauma (fractures, subluxations, ligamentous instability, or a combination of these problems) were treated with Caspar plating. All patients obtained fusion, and stability was achieved immediately after surgery without external stabilization. No unusual surgical complications occurred, and the most dreaded complication of dural penetration by drilling or screw placement was not observed. This report details the neurological presentation, anatomical lesions, surgical therapy, and outcome of these patients. Caspar plating combines the advantage of an anterior surgical approach with immediate postoperative stabilization without external stabilization. This advantage persists even in the presence of posterior ligamentous instability. The technique is an important addition to the surgical treatment of cervical trauma.

  7. Dynamic plate osteosynthesis for fracture stabilization: how to do it

    Directory of Open Access Journals (Sweden)

    Juerg Sonderegger

    2010-01-01

    Full Text Available Plate osteosynthesis is one treatment option for the stabilization of long bones. It is widely accepted to achieve bone healing with a dynamic and biological fixation where the perfusion of the bone is left intact and micromotion at the fracture gap is allowed. The indications for a dynamic plate osteosynthesis include distal tibial and femoral fractures, some midshaft fractures, and adolescent tibial and femoral fractures with not fully closed growth plates. Although many lower limb shaft fractures are managed successfully with intramedullary nails, there are some important advantages of open-reduction-and-plate fixation: the risk of malalignment, anterior knee pain, or nonunion seems to be lower. The surgeon performing a plate osteosynthesis has the possibility to influence fixation strength and micromotion at the fracture gap. Long plates and oblique screws at the plate ends increase fixation strength. However, the number of screws does influence stiffness and stability. Lag screws and screws close to the fracture site reduce micromotion dramatically. Dynamic plate osteosynthesis can be achieved by applying some simple rules: long plates with only a few screws should be used. Oblique screws at the plate ends increase the pullout strength. Two or three holes at the fracture site should be omitted. Lag screws, especially through the plate, must be avoided whenever possible. Compression is not required. Locking plates are recommended only in fractures close to the joint. When respecting these basic concepts, dynamic plate osteosynthesis is a safe procedure with a high healing and a low complication rate. 

  8. Laboratory plate tectonics: a new experiment.

    Science.gov (United States)

    Gans, R F

    1976-03-26

    A "continent" made of a layer of hexagonally packed black polyethylene spheres floating in clear silicon oil breaks into subcontinents when illuminated by an ordinary incandescent light bulb. This experiment may be a useful model of plate tectonics driven by horizontal temperature gradients. Measurements of the spreading rate are made to establish the feasibility of this model.

  9. Experiments on elastic cloaking in thin plates.

    Science.gov (United States)

    Stenger, Nicolas; Wilhelm, Manfred; Wegener, Martin

    2012-01-06

    Following a theoretical proposal [M. Farhat et al., Phys. Rev. Lett. 103, 024301 (2009)], we design, fabricate, and characterize a cloaking structure for elastic waves in 1 mm thin structured polymer plates. The cloak consists of 20 concentric rings of 16 different metamaterials, each being a tailored composite of polyvinyl chloride and polydimethylsiloxane. By using stroboscopic imaging with a camera from the direction normal to the plate, we record movies of the elastic waves for monochromatic plane-wave excitation. We observe good cloaking behavior for carrier frequencies in the range from 200 to 400 Hz (one octave), in good agreement with a complete continuum-mechanics numerical treatment. This system is thus ideally suited for demonstration experiments conveying the ideas of transformation optics.

  10. Stability of hard plates on soft substrates and application to the design of bioinspired segmented armor

    Science.gov (United States)

    Martini, R.; Barthelat, F.

    2016-07-01

    Flexible natural armors from fish, alligators or armadillo are attracting an increasing amount of attention from their unique and attractive combinations of hardness, flexibility and light weight. In particular, the extreme contrast of stiffness between hard plates and surrounding soft tissues give rise to unusual and attractive mechanisms, which now serve as model for the design of bio-inspired armors. Despite a growing interest in bio-inspired flexible protection, there is little guidelines as to the choice of materials, optimum thickness, size, shape and arrangement for the protective plates. In this work, we focus on a failure mode we recently observed on natural and bio-inspired scaled armors: the unstable tilting of individual scales subjected to off-centered point forces. We first present a series of experiments on this system, followed by a model based on contact mechanics and friction. We condense the result into a single stability diagram which capture the key parameters that govern the onset of plate tilting from a localized force. We found that the stability of individual plates is governed by the location of the point force on the plate, by the friction at the surface of the plate, by the size of the plate and by the stiffness of the substrate. We finally discuss how some of these parameters can be optimized at the design stage to produce bio-inspired protective systems with desired combination of surface hardness, stability and flexural compliance.

  11. Stability of flow over plates with porous suction strips

    Science.gov (United States)

    Reed, H. L.; Nayfeh, A. H.

    1981-01-01

    This paper addresses the stability of two-dimensional, incompressible boundary-layer flow over plates with suction through porous strips. The mean flow is calculated using linearized triple-deck, closed-form solutions. The stability results of the triple-deck theory are shown to be in good agreement with those of the interacting boundary layers. Then different configurations of number, spacing, and mass flow rate through such porous strips are analyzed and compared with nonsimilar uniform-suction stability results from the point of view of applicability to laminar flow control.

  12. Superior long-term stability of a glucose biosensor based on inserted barrel plating gold electrodes.

    Science.gov (United States)

    Hsu, Cheng-Teng; Hsiao, Hung-Chan; Fang, Mei-Yen; Zen, Jyh-Myng

    2009-10-15

    Disposable one shot usage blood glucose strips are routinely used in the diagnosis and management of diabetes mellitus and their performance can vary greatly. In this paper we critically evaluated the long-term stability of glucose strips made of barrel plating gold electrodes. Compared to other glucose biosensing platforms of vapor deposited palladium and screen printed carbon electrodes, the proposed glucose biosensor was found to show the best stability among the three biosensing platforms in thermal acceleration experiments at 40 degrees C for 6 months with an average bias of 3.4% at glucose concentrations of 5-20 mM. The precision test of this barrel plating gold glucose biosensor also showed the best performance (coefficients of variation in the range of 1.4-2.4%) in thermal acceleration experiments at 40 degrees C, 50 degrees C and 70 degrees C for 27 days. Error grid analysis revealed that all measurements fell in zone A and zone B. Regression analysis showed no significant difference between the proposed biosensor and the reference method at 99% confidence level. The amperometric glucose biosensor fabricated by inserting two barrel plating gold electrodes onto an injection-molding plastic base followed by immobilizing with a bio-reagent layer and membrane was very impressive with a long-term stability up to 2.5 years at 25 degrees C. Overall, these results indicated that the glucose oxidase/barrel plating gold biosensing platform is ideal for long-term accurate glycemic control.

  13. Influence of location and parameters of stiffeners on the stability of a square plate under shear

    Directory of Open Access Journals (Sweden)

    Pritykin Aleksey Igorevich

    Full Text Available Application of flexible-walled beams is rather effective because the reducing of wall thickness compared to ordinary welded beams leads to substantial reduction of metal expenditure for the walls and its more rational use. The operation experience of such beams shows that the loss of local stability of a wall takes place near bearing cross section with characteristic diagonal type of half waves, indicating, that the reason for the stability loss is in shear deformation. In plate girder with slender web big transverse forces appear, which leads to its buckling as a result of shear. One of the ways to increase stability of the parts of web near supports is to install stiffeners. In the given work the task of finding critical stresses of fixed square plate with installed inclined stiffener is considered. Investigations were performed with the help of finite element method and were experimentally checked. Recommendations were given on the choice of optimal size of the stiffener.

  14. Resistive Plate Chambers performance with Cosmic Rays in the CMS experiment

    CERN Document Server

    Piccolo, D; Genchev, V; Iaydjiev, P; Stoykova, S; Sultanov, G; Trayanov, R; Dimitrov, A; Litov, L; Pavlov, B; Petkov, P; Marinov, A; Thyssen, F; Tytgat, M; Verwilligen, P; Zaganidis, N; Akimenko, S; Ball, A; Crotty, I; Guida, R; Sharma, A; Van Doninck, W; Abbrescia, M; Iaselli, G; Marangelli, B; Nuzzo, S; Pugliese, G; Romano, F; Roselli, G; Trentadue, R; Tupputi, S; Colaleo, A; Loddo, F; Ranieri, A; Cimmino, A; Sciacca, C; Buontempo, S; Cavallo, N; Fabozzi, F; Lomidze, D; Paolucci, P; Benussi, L; Bertani, M; Bianco, S; Colafranceschi, S; Fabbri, F L; Baesso, P; Pagano, D; Ratti, S P; Vitulo, P; Viviani, C; Avila, C; Carrillo, C; Gomez, B; Ocampo, A; Osorio, A; Sanabria, J C; Polese, G; Tuuva, T; Bunkowski, K; Cwiok, M; Doroba, K; Kalinowski, A; Konecki, M; Krolikowski, J; Kierzkowski, K; Kudla, I M; Oklinski, W; Pietrusinski, M; Bluj, M; Fruboes, T; Gorski, M; Kazana, M; Szleper, M; Wrochna, G; Zalewski, P; Poznik, K T; Zabolotny, W; Ban, Y; Qian, S J; Ye, Y L; Ahmad, M; Ahmed, I; Ahmed, W; Asghar, M I; Butt, J B; Hoorani, H R; Hussain, I; Khan, W A; Khurshid, T; Malik, I A; Muhammad, S; Qazi, S F; Shahzad, H; Cho, S W; Jo, M; Hong, B; Kim, C; Kim, H C; Kim, J H; Lee, H S; Lee, K S; Moon, D H; Park, S; Rhee, H B; Seo, E S; Shin, S S; Sim, K S; Lee, J S; Lee, S E

    2010-01-01

    The Resistive Plate Chambers are used in the CMS experiment as a dedicated muon trigger both in barrel and endcap system. About 4000 square meter of double gap RPCs have been produced and have been installed in the experiment since more than one year and half. The full barrel system and a fraction of the endcaps have been monitored to study dark current behaviour and system stability, and have been extensively commissioned with Cosmic Rays collected by the full CMS experiment.

  15. Available: lead plate from COMPASS experiment

    CERN Multimedia

    The COMPASS collaboration

    2014-01-01

    The COMPASS collaboration would like to offer the possibility to take over a large and thick lead plate, since it is not required anymore in the spectrometer.   It has the following dimensions: thickness 100 mm, width 4.4 m and height 2.0 m, with a square hole in the middle with dimensions of 40 cm x 40 cm. The measured weight including the metal frame it is housed in is 10,180 kg. The CERN stores reference is 44.13.30.100.9. Please contact Erwin Bielert (erwin.bielert@cern.ch or 160539) for further information and details.

  16. Stability analysis of the fluttering and autorotation of flow-induced rotation of a hinged flat plate

    Institute of Scientific and Technical Information of China (English)

    MIRZAEISEFAT Sina; FERNANDES Antonio Carlos

    2013-01-01

    This work describes investigations performed on the interaction of uniform current and freely rotating plate about a fixed vertical axis. Fluttering and autorotation are two different motions that may occur during the flow induced rotation. The dimensional analysis proves that the motion in flow induced rotation motion is governed essentially by the dimensionless moment of inertia and Reynolds number. Certain combinations define the stability boundaries between fluttering and autorotation. Fluttering is oscillation of body about a vertical axis and the autorotation is a name given to the case when the body turns continuously about the vertical axis. First, the loads and moment coefficients are calculated by experiments and streamline theory for different angles of attack for a fixed flat plate. Then for dynamic case, a bifurcation diagram is presented based on experiments to classify different motion states of flow induced rotation. Finally, a dynamical model is proposed for stability analysis of flow induced rotation of a flat plate.

  17. Production of quartz plates for CMS-CASTOR Experiment

    CERN Document Server

    Adiguzel, Aytul; Ayhan, Aydin; Bakirci, Mustafa Numan; Basegmez, Suzan; Beaumont, Willem; Borras, Kerstin; Campbell, Alan; De Paula Carvalho, W; Çerçi, Salim; De Jesus Damiao, Dilson; Dogangün, O; Dumanoglu, Isa; d'Enterria, David; Erchov, Y; Eskut, Eda; Figueiredo, D; Girgis, Semiray; Göttlicher, P; Gouskos, Loukas; Gurpinar, Emine; Hos, Ilknur; Katkov, Igor; Katsas, Panagiotis; Khein, Lev; Knutsson, Albert; Kuznetsov, Andrey; Lebeau, Michel; Van Mechelen, Pierre; Muhl, Carsten; Musienko, Yuri; Ochesanu, Silvia; Onengüt, G; Onengut, G Jr; Ozdemir, Kadri; Panagiotou, Apostolos; Polatoz, A; Ripert, Marion; Shileev, K; Sogut, Kenan; Tiflov, B TaliV; Kayis-Topaksu, A; Uzun, Dilber

    2008-01-01

    Light transmission rate performance of $102$ irradiated quartz samples was measured to select the best quartz plates for CMS-CASTOR calorimeter. All the produced quartz plates were originally used in a previous CERN experiment, DELPHI. Three different doses of $^{60}$Co source were used with the collaboration of PSI (Paul Scherrer Institute, Villigen PSI, Switzerland.) to study the transmission rate performance of the quartz samples after irradiation for different incident light, ranging from $250$ to $700$ nm in $5$ nm increasing steps. All samples show different decrease in the rate with wavelength for different doses. Three different steps were followed before irradiation to find out the best way of cleaning the original DELPHI Cu/Cr tracks on the samples. Results of these measurements presented here correspond to the quartz plates that will be used in one hadronic sector of CASTOR calorimeter until end of 2008. For the full calorimeter new quartz plates will be installed. We also present the light transmi...

  18. Principles of moment distribution applied to stability of structures composed of bars or plates

    Science.gov (United States)

    Lundquist, Eugene E; Stowell, Elbridge Z; Schuette, Evan H

    1945-01-01

    The principles of the cross method of moment distribution, which have previously been applied to the stability of structures composed of bars under axial load, are applied to the stability of structures composed of long plates under longitudinal load. A brief theoretical treatment of the subject, as applied to structures composed of either bars or plates, is included, together with an illustrative example for each of these two types of structure. An appendix presents the derivation of the formulas for the various stiffnesses and carry-over factors used in solving problems in the stability of structures composed of long plates.

  19. Variational Stability Form for the Capacitance of an Arbitrarily Shaped Conducting Plate

    Institute of Scientific and Technical Information of China (English)

    LIANGChanghong; LILong; ZHAIHuiqing

    2004-01-01

    A new analytical method for finding the capacitance of an arbitrarily shaped conducting plate is presented in this paper. If the charge density suitable to fringe conditions and the appropriate charge barycenter are supposed, the variational stability form with high accuracy for the capacitance C can be achieved by simple curve integrals or the superposition of basic triangles. In this paper, some analytical examples such as an elliptical plate, a regular polygonal plate and a rectangular plate are given. It is worth pointing out that the analytical closed-form for an elliptical plate is accurate. Comparing the result of the analytical closed-form for the square plate and the numerical result of Richardson's extrapolation, the relative error is less than 1.7%. Furthermore, the relationship between the charge barycenter and the variational stability is discussed.

  20. Two-dimensional simulations of steady perforated-plate stabilized premixed flames

    KAUST Repository

    Altay, H. Murat

    2010-03-17

    The objective of this work is to examine the impact of the operating conditions and the perforated-plate design on the steady, lean premixed flame characteristics. We perform two-dimensional simulations of laminar flames using a reduced chemical kinetics mechanism for methane-air combustion, consisting of 20 species and 79 reactions. We solve the heat conduction problem within the plate, allowing heat exchange between the gas mixture and the solid plate. The physical model is based on a zero-Mach-number formulation of the axisymmetric compressible conservation equations. The results suggest that the flame consumption speed, the flame structure, and the flame surface area depend significantly on the equivalence ratio, mean inlet velocity, the distance between the perforated-plate holes and the plate thermal conductivity. In the case of an adiabatic plate, a conical flame is formed, anchored near the corner of the hole. When the heat exchange between themixture and the plate is finite, the flame acquires a Gaussian shape stabilizing at a stand-off distance, that grows with the plate conductivity. The flame tip is negatively curved; i.e. concave with respect to the reactants. Downstream of the plate, the flame base is positively curved; i.e. convex with respect to the reactants, stabilizing above a stagnation region established between neighboring holes. As the plate\\'s thermal conductivity increases, the heat flux to the plate decreases, lowering its top surface temperature. As the equivalence ratio increases, the flame moves closer to the plate, raising its temperature, and lowering the flame stand-off distance. As the mean inlet velocity increases, the flame stabilizes further downstream, the flame tip becomes sharper, hence raising the burning rate at that location. The curvature of the flame base depends on the distance between the neighboring holes; and the flame there is characterized by high concentration of intermediates, like carbon monoxide. © 2010 Taylor

  1. The San Andreas fault experiment. [gross tectonic plates relative velocity

    Science.gov (United States)

    Smith, D. E.; Vonbun, F. O.

    1973-01-01

    A plan was developed during 1971 to determine gross tectonic plate motions along the San Andreas Fault System in California. Knowledge of the gross motion along the total fault system is an essential component in the construction of realistic deformation models of fault regions. Such mathematical models will be used in the future for studies which will eventually lead to prediction of major earthquakes. The main purpose of the experiment described is the determination of the relative velocity of the North American and the Pacific Plates. This motion being so extremely small, cannot be measured directly but can be deduced from distance measurements between points on opposite sites of the plate boundary taken over a number of years.

  2. Dynamic Stability of Viscoelastic Plates with Finite Deformation and Shear Effects

    Institute of Scientific and Technical Information of China (English)

    李晶晶; 程昌钧; 等

    2002-01-01

    Based on Reddy's theory of plates with higher-order shear deformations and the Boltzmann superposition principles,the governing equations were established for dynamic stability of viscoelastic plates with finite deformations taking account of shear effects,The Galerkin method was applied to simplify the set of equations.The numerical methods in nonlinear dynamics were used to solve the simplified system.It could e seen that there are plenty of dynamic properties for this kind of viscoelastic plates under transverse harmonic loads.The influences of the transverse shear deformations and material parameter on the dynamic behavior of nonlinear viscoelatic plates were investigated.

  3. Evaluation of Thin Plate Hydrodynamic Stability through a Combined Numerical Modeling and Experimental Effort

    Energy Technology Data Exchange (ETDEWEB)

    Tentner, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Bojanowski, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Feldman, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Wilson, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Solbrekken, G [Univ. of Missouri, Columbia, MO (United States); Jesse, C. [Univ. of Missouri, Columbia, MO (United States); Kennedy, J. [Univ. of Missouri, Columbia, MO (United States); Rivers, J. [Univ. of Missouri, Columbia, MO (United States); Schnieders, G. [Univ. of Missouri, Columbia, MO (United States)

    2017-05-01

    An experimental and computational effort was undertaken in order to evaluate the capability of the fluid-structure interaction (FSI) simulation tools to describe the deflection of a Missouri University Research Reactor (MURR) fuel element plate redesigned for conversion to lowenriched uranium (LEU) fuel due to hydrodynamic forces. Experiments involving both flat plates and curved plates were conducted in a water flow test loop located at the University of Missouri (MU), at conditions and geometries that can be related to the MURR LEU fuel element. A wider channel gap on one side of the test plate, and a narrower on the other represent the differences that could be encountered in a MURR element due to allowed fabrication variability. The difference in the channel gaps leads to a pressure differential across the plate, leading to plate deflection. The induced plate deflection the pressure difference induces in the plate was measured at specified locations using a laser measurement technique. High fidelity 3-D simulations of the experiments were performed at MU using the computational fluid dynamics code STAR-CCM+ coupled with the structural mechanics code ABAQUS. Independent simulations of the experiments were performed at Argonne National Laboratory (ANL) using the STAR-CCM+ code and its built-in structural mechanics solver. The simulation results obtained at MU and ANL were compared with the corresponding measured plate deflections.

  4. Long-term optical stability of fluorescent solar concentrator plates

    NARCIS (Netherlands)

    Slooff, Lenneke H.; Bakker, Nicolaas J.; Sommeling, Paul M.; Büchtemann, Andreas; Wedel, Armin; Van Sark, Wilfried G J H M

    2014-01-01

    Fluorescent solar concentrators offer an alternative approach for low-cost photovoltaic energy conversion. For successful application, not only the power conversion efficiency and cost are important, but also lifetime or stability of the devices. As today's concentrator is made of polymer sheets

  5. Long-term optical stability of fluorescent solar concentrator plates

    NARCIS (Netherlands)

    Slooff, Lenneke H.; Bakker, Nicolaas J.; Sommeling, Paul M.; Büchtemann, Andreas; Wedel, Armin; Van Sark, Wilfried G J H M

    2014-01-01

    Fluorescent solar concentrators offer an alternative approach for low-cost photovoltaic energy conversion. For successful application, not only the power conversion efficiency and cost are important, but also lifetime or stability of the devices. As today's concentrator is made of polymer sheets con

  6. Stability of a cantilevered skew inhomogeneous plate in supersonic gas flow

    Science.gov (United States)

    Isaulova, T. N.; Lavit, I. M.

    2011-07-01

    This paper considers the vibrations of a skew inhomogeneous plate in gas flow. The plate is clamped in a certain section of one of its sides. Interaction of the flow with the plate is described using piston theory. The problem solution is based on the Hamilton's variational principle and finite element method. The calculation results are compared with known data of theoretical studies and experiments. For the inhomogeneous plate, similarity parameters were established for the problem, which, in practically important cases, appears to be self-similar for one of the similarity parameters. This allows one to reduce the solution of this problem to the solution of an algebraic eigenvalue problem.

  7. An aerator for brain slice experiments in individual cell culture plate wells.

    Science.gov (United States)

    Dorris, David M; Hauser, Caitlin A; Minnehan, Caitlin E; Meitzen, John

    2014-12-30

    Ex vivo acute living brain slices are a broadly employed and powerful experimental preparation. Most new technology regarding this tissue has involved the chamber used when performing electrophysiological experiments. Alternatively we instead focus on the creation of a simple, versatile aerator designed to allow maintenance and manipulation of acute brain slices and potentially other tissue in a multi-well cell culture plate. Here we present an easily manufactured aerator designed to fit into a 24-well cell culture plate. It features a nylon mesh and a single microhole to enable gas delivery without compromising tissue stability. The aerator is designed to be individually controlled, allowing both high throughput and single well experiments. The aerator was validated by testing material leach, dissolved oxygen delivery, brain slice viability and neuronal electrophysiology. Example experiments are also presented, including a test of whether β1-adrenergic receptor activation regulates gene expression in ex vivo dorsal striatum using qPCR. Key differences include enhanced control over gas delivery to individual wells containing brain slices, decreased necessary volume, a sample restraint to reduce movement artifacts, the potential to be sterilized, the avoidance of materials that absorb water and small biological molecules, minimal production costs, and increased experimental throughput. This new aerator is of high utility and will be useful for experiments involving brain slices and other potentially tissue samples in 24-well cell culture plates. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Methodical Specifics of Thermal Experiments with Thin Carbon Reinforced Plates

    Directory of Open Access Journals (Sweden)

    O. V. Denisov

    2015-01-01

    Full Text Available Polymer composite materials (CM are widely used in creation of large space constructions, especially reflectors of space antennas. Composite materials should provide high level of specific stiffness and strength for space structures. Thermal conductivity in reinforcement plane is a significant factor in case of irregular heating space antennas. Nowadays, data on CM reinforcement plane thermal conductivity are limited and existing methods of its defining are imperfect. Basically, traditional methods allow us to define thermal conductivity in perpendicular direction towards the reinforcement plane on the samples of round or rectangular plate. In addition, the thickness of standard samples is larger than space antenna thickness. Consequently, new methods are required. Method of contact heating, which was developed by BMSTU specialists with long hollow carbon beam, could be a perspective way. This article is devoted to the experimental method of contact heating on the thin carbon plates.Thermal tests were supposed to provide a non-stationary temperature field with a gradient being co-directional with the plane reinforcement in the material sample. Experiments were conducted in vacuum chamber to prevent unstructured convection. Experimental thermo-grams processing were calculated by 1-d thermal model for a thin plate. Influence of uncertainty of experimental parameters, such as (radiation emission coefficients of sample surface, glue, temperature sensors and uncertainty of sensors placement on the result of defined thermal conductivity has been estimated. New data on the thermal conductivity in reinforcement plane were obtained within 295 - 375 K temperature range, which can be used to design and develop reflectors of precision space antennas. In the future it is expedient to conduct tests of thin-wall plates from carbon fiber-reinforced plastic in wide temperature range, especially in the low-range temperatures.

  9. Analysis of Interplanetary Dust Experiment Detectors and Other Witness Plates

    Science.gov (United States)

    Griffis, D. P.; Wortman, J. J.

    1992-01-01

    The development of analytical procedures for identifying the chemical composition of residue from impacts that occurred on the Interplanetary Dust Experiment (IDE) detectors during the flight of Long Duration Exposure Facility (LDEF) and the carrying out of actual analysis on IDE detectors and other witness plates are discussed. Two papers on the following topics are presented: (1) experimental analysis of hypervelocity microparticle impact sites on IDE sensor surfaces; and (2) contaminant interfaces with secondary Ion Mass Spectrometer (SIMS) analysis of microparticle impactor residues on LDEF surfaces.

  10. Fixed vs dynamic plate complications following multilevel anterior cervical corpectomy and fusion with posterior stabilization.

    Science.gov (United States)

    Epstein, N E

    2003-07-01

    Comparison of fixed vs dynamic plate complications in cervical surgery. : New York, USA. Anterior cervical plate-related complications were evaluated following 66 anterior cervical corpectomy and fusion (ACF) with posterior stabilization (PWF) procedures performed in patients with ossification of the posterior longitudinal ligament (OPLL). Clinical data were comparable for both patient populations. Patients averaged between 52 and 53 years of age. The male to female ratio was approximately 2:1. Surgery addressed MR and CT documented multilevel OPLL in all patients accompanied by spondylosis and stenosis. Preoperatively average Nurick Grades ranged from 3.6 to 3.7. Anterior cervical corpectomies included an average of 2.6-3.0 vertebral bodies, while PWF covered seven levels. Fixed plates were applied in the initial 38 patients, while the latter 28 patients had dynamic plates (ABC, Aesculap, Tuttlingen, Germany) applied. Halo devices were used until fusion was documented on both X-ray and 2D-CT studies. Patients were followed-up for an average of 5.4 years in the fixed-plated groups, and 2.7 years in the dynamic-plated population. CT and dynamic X-ray confirmed that fusion occurred an average of 4.5-4.9 months postoperatively. Five (13%) fixed plates (Medtronic, Sofamor Danek, Memphis, TN, USA) failed warranting secondary surgery, while only one (3.6%) dynamic-plated patient developed a pseudarthrosis and required secondary posterior fusion. Higher failure rates follow multilevel ACF as compared with anterior diskectomy and fusion required to resect multilevel OPLL. Vaccaro et al observed a 9% failure rate following two-level ACFs and 50% failure rate following three-level ACFs performed with fixed plates. In this series, the plate extrusion rate was reduced to 3.6% when dynamic plates were applied.

  11. Numerical-perturbation technique for stability of flat-plate boundary layers with suction

    Science.gov (United States)

    Reed, H. L.; Nayfeh, A. H.

    1986-01-01

    A numerical-perturbation scheme is proposed for determining the stability of flows over plates with suction through a finite number of porous suction strips. The basic flow is calculated as the sum of the Blasius flow and closed-form linearized triple-deck solutions of the flow due to the strips. A perturbation technique is used to determine the increment a(ij) in the complex wavenumber at a given location x(j) due to the presence of a strip centered at x(i). The end result is a set of influence coefficients that can be used to determine the growth rates and amplification factors for any suction levels without repeating the calculations. The numerical-perturbation results are verified by comparison with interacting boundary layers for the case of six strips and the experimental data of Reynolds and Saric for single- and multiple-strip configurations. The influence coefficient form of the solution suggests a scheme for optimizing the strip configuration. The results show that one should concentrate the suction near branch I of the neutral stability curve, a conclusion verified by the experiments.

  12. ON THE BENDING, VIBRATION AND STABILITY OF LAMINATED RECTANGULAR PLATES WITH TRANSVERSELY ISOTROPIC LAYERS

    Institute of Scientific and Technical Information of China (English)

    丁皓江; 陈伟球; 徐荣桥

    2001-01-01

    A method based on newly presented state space formulations is developed for analyzing the bending, vibration and stability of laminated transversely isotropic rectangular plates with simply supported edges. By introducing two displacement functions and two stress functions, two independent state equations were constructed based on the three-dimensional elasticity equations for transverse isotropy. The original differential equations are thus decoupled with the order reduced that will facilitate obtaining solutions of various problems.For the simply supported rectangular plate, two relations between the state variables at the top and bottom surfaces were established. In particular, for the free vibration (stability)problem, it is found that there exist two independent classes: One corresponds to the pure in-plane vibration (stability) and the other to the general bending vibration ( stability).Numerical examples are finally presented and the effects of some parameters are discussed.

  13. Stabilization of mobile mandibular segments in mandibular reconstruction: use of spanning reconstruction plate.

    Science.gov (United States)

    Yap, Yan Lin; Lim, Jane; Ong, Wei Chen; Yeo, Matthew; Lee, Hanjing; Lim, Thiam Chye

    2012-09-01

    The fibular free flap is the gold standard for mandibular reconstruction. Accurate 3-dimensional contouring and precise alignment of the fibula is critical for reestablishing native occlusion and facial symmetry. Following segmental mandibulectomy, the remaining mandibular fragments become freely mobile. Various stabilization methods including external fixation, intermaxillary fixation, and preplating with reconstruction plate have been used. We describe a modification to the preplating technique. After wide resection of buccal squamous cell carcinoma, our patient had an 11-cm mandibular defect from the angle of the left mandible to the right midparasymphyseal region. A single 2.0-mm Unilock® (Synthes, Singapore) plate was used to span the defect. This was placed on the vestibular aspect of the superior border of the mandibular remnants before resection. Segmental mandibulectomy was then performed with the plate removed. The spanning plate was then reattached to provide rigid fixation. The fibular bone was contoured with a single osteotomy and reattached. The conventional technique involves molding of the plate at the inferior border of the mandible. This is time-consuming and not possible in patients with distorted mandibular contour. It is also difficult to fit the osteotomized fibula to the contoured plate. In comparison, the superiorly positioned spanning plate achieve rigid fixation of the mandible while leaving the defect completely free and unhampered by hardware, allowing space for planning osteotomies and easier fixation of the neomandible. Using this modified technique, we are able to recreate the original mandibular profile with ease.

  14. Experiments to investigate lift production mechanisms on pitching flat plates

    Science.gov (United States)

    Stevens, P. R. R. J.; Babinsky, H.

    2017-01-01

    Pitching flat plates are a useful simplification of flapping wings, and their study can provide useful insights into unsteady force generation. Non-circulatory and circulatory lift producing mechanisms for low Reynolds number pitching flat plates are investigated. A series of experiments are designed to measure forces and study the unsteady flowfield development. Two pitch axis positions are investigated, namely a leading edge and a mid-chord pitch axis. A novel PIV approach using twin laser lightsheets is shown to be effective at acquiring full field of view velocity data when an opaque wing model is used. Leading-edge vortex (LEV) circulations are extracted from velocity field data, using a Lamb-Oseen vortex fitting algorithm. LEV and trailing-edge vortex positions are also extracted. It is shown that the circulation of the LEV, as determined from PIV data, approximately matches the general trend of an unmodified Wagner function for a leading edge pitch axis and a modified Wagner function for a mid-chord pitch axis. Comparison of experimentally measured lift correlates well with the prediction of a reduced-order model for a LE pitch axis.

  15. TANDEM COLD MILL PROCESS STABILITY IMPROVEMENT WITH CHROME PLATED WORK ROLLS APPLICATION

    Directory of Open Access Journals (Sweden)

    Sergio Luiz Muratori

    2012-09-01

    Full Text Available The stability of a tandem cold mill is essential to assure the thickness control, the main attribute of cold rolled steel sheets. This stability can be defined as the capability to control the process variables that act direct at the thickness. Among the most important variables are the first stand (mill linear speed and the sheet speed at the interstice ahead of it. This work shows how the chrome plated work rolls application improved this speed control and consequently the stability, which enabled an increase in the work roll rolling campaign (rolling sequence program in such a way significantly higher, compared to when using a non chrome plated work rolls. As results, significantly improvements of work rolls campaigns and the consequent increase of the equipment availability are presented.

  16. Dynamic stability experiment of Maglev systems

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Y.; Mulcahy, T.M.; Chen, S.S. [and others

    1995-04-01

    This report summarizes the research performed on Maglev vehicle dynamic stability at Argonne National Laboratory during the past few years. It also documents magnetic-force data obtained from both measurements and calculations. Because dynamic instability is not acceptable for any commercial Maglev system, it is important to consider this phenomenon in the development of all Maglev systems. This report presents dynamic stability experiments on Maglev systems and compares their numerical simulation with predictions calculated by a nonlinear dynamic computer code. Instabilities of an electrodynamic system (EDS)-type vehicle model were obtained from both experimental observations and computer simulations for a five-degree-of-freedom Maglev vehicle moving on a guideway consisting of double L-shaped aluminum segments attached to a rotating wheel. The experimental and theoretical analyses developed in this study identify basic stability characteristics and future research needs of Maglev systems.

  17. Thermal analysis of a direct-gain room with shape-stabilized PCM plates

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Guobing; Zhang, Yinping; Lin, Kunping; Xiao, Wei [Department of Building Science, School of Architecture, Tsinghua University, Beijing 100084 (China)

    2008-06-15

    The thermal performance of a south-facing direct-gain room with shape-stabilized phase change material (SSPCM) plates has been analysed using an enthalpy model. Effects of the following factors on room air temperature are investigated: the thermophysical properties of the SSPCM (melting temperature, heat of fusion and thermal conductivity), inner surface convective heat transfer coefficient, location and thickness of the SSPCM plate, wall structure (external thermal insulation and wallboard material) etc. The results show that: (1) for the present conditions, the optimal melting temperature is about 20{sup o}C and the heat of fusion should not be less than 90 kJ kg{sup -1}; (2) it is the inner surface convection, rather than the internal conduction resistance of SSPCM, that limits the latent thermal storage; (3) the effect of PCM plates located at the inner surface of interior wall is superior to that of exterior wall (the south wall); (4) external thermal insulation of the exterior wall obviously influences the operating effect and period of the SSPCM plates and the indoor temperature in winter; (5) the SSPCM plates create a heavyweight response to lightweight constructions with an increase of the minimum room temperature at night by up to 3{sup o}C for the case studied; (6) the SSPCM plates really absorb and store the solar energy during the daytime and discharge it later and improve the indoor thermal comfort degree at nighttime. (author)

  18. Development of glass resistive plate chambers for INO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Datar, V.M. [Bhabha Atomic Research Centre, Mumbai (India); Jena, Satyajit [Indian Institute of Technology Bombay, Mumbai (India); Kalmani, S.D. [Tata Institute of Fundamental Research, Mumbai (India); Mondal, N.K. [Tata Institute of Fundamental Research, Mumbai (India)], E-mail: nkm@tifr.res.in; Nagaraj, P.; Reddy, L.V.; Saraf, M.; Satyanarayana, B.; Shinde, R.R.; Verma, P. [Tata Institute of Fundamental Research, Mumbai (India)

    2009-05-01

    The India-based Neutrino Observatory (INO) collaboration is planning to build a massive 50 kton magnetised Iron Calorimeter (ICAL) detector, to study atmospheric neutrinos and to make precision measurements of the parameters related to neutrino oscillations. Glass Resistive Plate Chambers (RPCs) of about 2 mx2 m in size are going to be used as active elements for the ICAL detector. We have fabricated a large number of glass RPC prototypes of 1 mx1 m in size and have studied their performance and long term stability. In the process, we have developed and produced a number of materials and components required for fabrication of RPCs. We have also designed and optimised a number of fabrication and quality control procedures for assembling the gas gaps. In this paper we will review our various activities towards development of glass RPCs for the INO ICAL detector. We will present results of the characterisation studies of the RPCs and discuss our plans to prototype 2 mx2 m sized RPCs.

  19. Stability of MHD jet flows between nonconducting plates in a transverse field

    Energy Technology Data Exchange (ETDEWEB)

    Levin, V.B.; Shtern, V.N.

    1985-06-01

    The linear stability of jet flows of a conducting fluid between parallel nonconducting plates in a transverse field is examined. It is assumed that the flow is caused by the current between linear electrodes situated on one of the plates, and that the velocity profile for the initial flow and for perturbations is a Hartmann profile across the plates. Hartmann boundary layers are modeled with respect to the friction force. Neutral curves and dependences of the critical Reynolds number on the Hartmann number are obtained; the dependence is found to be linear for finite-width electrodes, and proportional to the square root of Ha for infinitely thin electrodes. A comparison with experimental data is carried out. 13 references.

  20. Thermal stability analysis of eccentrically stiffened Sigmoid-FGM plate with metal–ceramic–metal layers based on FSDT

    Directory of Open Access Journals (Sweden)

    Pham Hong Cong

    2016-12-01

    Full Text Available This paper researches the thermal stability of eccentrically stiffened plates made of functionally graded materials (FGM with metal–ceramic–metal layers subjected to thermal load. The equilibrium and compatibility equations for the plates are derived by using the first-order shear deformation theory of plates, taking into account both the geometrical nonlinearity in the von Karman sense and initial geometrical imperfections with Pasternak type elastic foundations. By applying Galerkin method and using stress function, effects of material and geometrical properties, elastic foundations, temperature-dependent material properties, and stiffeners on the thermal stability of the eccentrically stiffened S-FGM plates in thermal environment are analyzed and discussed.

  1. The vibration and stability analysis of moderate thick plates by the method of lines

    Science.gov (United States)

    Tang, Shou-Gao; Yuan, Si

    1992-06-01

    The method of lines based on Hu Hai-chang's theory for the vibration and stability of moderate thick plates is developed. The standard nonlinear ordinary differential equation (ODE) system for natural frequencies and critical load is given by use of ODE techniques; any indicated eigenvalue could be obtained directly from ODE solver by employing the so-called initial eigenfunction technique instead of the mode orthogonality condition. Numerical examples show that the present method is very effective and reliable.

  2. Stability of active mantle upwelling revealed by net characteristics of plate tectonics.

    Science.gov (United States)

    Conrad, Clinton P; Steinberger, Bernhard; Torsvik, Trond H

    2013-06-27

    Viscous convection within the mantle is linked to tectonic plate motions and deforms Earth's surface across wide areas. Such close links between surface geology and deep mantle dynamics presumably operated throughout Earth's history, but are difficult to investigate for past times because the history of mantle flow is poorly known. Here we show that the time dependence of global-scale mantle flow can be deduced from the net behaviour of surface plate motions. In particular, we tracked the geographic locations of net convergence and divergence for harmonic degrees 1 and 2 by computing the dipole and quadrupole moments of plate motions from tectonic reconstructions extended back to the early Mesozoic era. For present-day plate motions, we find dipole convergence in eastern Asia and quadrupole divergence in both central Africa and the central Pacific. These orientations are nearly identical to the dipole and quadrupole orientations of underlying mantle flow, which indicates that these 'net characteristics' of plate motions reveal deeper flow patterns. The positions of quadrupole divergence have not moved significantly during the past 250 million years, which suggests long-term stability of mantle upwelling beneath Africa and the Pacific Ocean. These upwelling locations are positioned above two compositionally and seismologically distinct regions of the lowermost mantle, which may organize global mantle flow as they remain stationary over geologic time.

  3. A Study of the Effect of Gold Thickness Distribution in the Jet Plating Process to Optimize Gold Usage and Plating Voltage Using Design of Experiments

    Directory of Open Access Journals (Sweden)

    Aramphongphun Chuckaphun

    2016-01-01

    Full Text Available A gold plating process in the electronics industry can be classified as (i all surface plating or (ii selective plating. Selective plating is more widely used than all surface plating because it can save more gold used in the plating process and takes less plating time. In this research, the selective plating process called jet plating was studied. Factors that possibly affected the gold usage and plating voltage were also studied to reduce the production cost. These factors included (a plating temperature, (b crystal (inhibitor amount, (c distance between workpiece and anode, (d plating current and (e plating speed. A two-level Full Factorial design with center points was first performed to screen the factors. A Central Composite Design (CCD was then employed to optimize the factors in jet plating. The amount of gold usage should be reduced to 0.366 g / 10,000 pieces, the plating speed should be increased to 4 m/min and the plating voltage should not exceed 8.0 V. According to the analysis, the optimal settings should be as follows: the plating temperature at 55.5 deg C, the crystal amount at 90%, the distance at 0.5 mm, the plating current at 2.8 A, and the plating speed at 4.5 m/min. This optimal setting led to gold usage of 0.350 g / 10,000 pieces and a plating voltage of 7.16 V. Confirmation runs of 30 experiments at the optimal conditions were then performed. It was found that the gold usage and the plating voltage of the confirmation runs were not different from the optimized gold usage and plating voltage. The optimal condition was then applied in production, which could reduce the gold usage by 4.5% and increase the plating speed by 12.5% while the plating voltage did not exceed the limit.

  4. Stability of boundary layers with porous suction strips: Experiment and theory

    Science.gov (United States)

    Reynolds, G. A.; Saric, W. S.; Reed, H. L.; Nayfeh, A. H.

    1982-01-01

    Low turbulence tunnel experiments on the stability and transition of 2 D boundary layers on flat plates with and without suction are described. A number of general suction cases are discussed. Test results showed that the maximum stabilization occurred when the suction was moved toward the Branch I neutral point. An analytical study of the stability of two dimensional, incompressible boundary layer flows over plates with suction through porous strips was performed. The mean flow was calculated using linearized triple deck, closed form solutions. The stability results of the triple deck theory are shown to be in good agreement with those of the interacting boundary layers. An analytical optimization scheme for the suction configuration was developd. Numerical calculations were performed corresponding to the experimental configurations. In each case, the theory correctly predicts the experimental results.

  5. Stability of extraoral vertical ramus osteotomy: plate fixation versus maxillomandibular/skeletal suspension wire fixation.

    Science.gov (United States)

    Mobarak, K A; Krogstad, O; Espeland, L; Lyberg, T

    2000-01-01

    The objective of this cephalometric study was to evaluate skeletal stability and time course of postoperative changes in 2 groups of mandibular prognathism patients following extraoral oblique vertical ramus osteotomy (VRO). One group (n = 22) received maxillomandibular fixation and skeletal suspension wires (MMF group) for a period of 8 weeks. In the other group (n = 22), the segments were rigidly fixed with plates and the patients were allowed to function immediately after surgery. Lateral cephalograms were taken on 5 occasions: immediately presurgical, immediately postsurgical, 8 weeks postsurgical, 6 months postsurgical, and 1 year postsurgical. During the first 8 weeks after surgery, the MMF group demonstrated posterior movement of the mandible, with an increase in mandibular plane angle, shortening of the rami, and dental compensations. Upon release of MMF and skeletal suspension wiring, a small anterior relapse tendency was observed, but the net setback 1 year after surgery was still greater than the actual surgical setback. In the plate fixation group, postoperative changes were mainly in the form of a small anterior relapse tendency in the range of 10% of the surgical setback. The results indicate that the use of plate fixation with VRO, while eliminating the inconvenience for the patient of several weeks of MMF and preventing the early side effects observed in the MMF group, also resulted in a more predictable surgical procedure, with excellent stability 1 year after surgery.

  6. Ex vivo biomechanical evaluation of pigeon (Columba livia) cadaver intact humeri and ostectomized humeri stabilized with caudally applied titanium locking plate or stainless steel nonlocking plate constructs.

    Science.gov (United States)

    Darrow, Brett G; Biskup, Jeffrey J; Weigel, Joseph P; Jones, Michael P; Xie, Xie; Liaw, Peter K; Tharpe, Josh L; Sharma, Aashish; Penumadu, Dayakar

    2017-05-01

    OBJECTIVE To evaluate mechanical properties of pigeon (Columba livia) cadaver intact humeri versus ostectomized humeri stabilized with a locking or nonlocking plate. SAMPLE 30 humeri from pigeon cadavers. PROCEDURES Specimens were allocated into 3 groups and tested in bending and torsion. Results for intact pigeon humeri were compared with results for ostectomized humeri repaired with a titanium 1.6-mm screw locking plate or a stainless steel 1.5-mm dynamic compression plate; the ostectomized humeri mimicked a fracture in a thin cortical bone. Locking plates were secured with locking screws (2 bicortical and 4 monocortical), and nonlocking plates were secured with bicortical nonlocking screws. Constructs were cyclically tested nondestructively in 4-point bending and then tested to failure in bending. A second set of constructs were cyclically tested non-destructively and then to failure in torsion. Stiffness, strength, and strain energy of each construct were compared. RESULTS Intact specimens were stiffer and stronger than the repair groups for all testing methods, except for nonlocking constructs, which were significantly stiffer than intact specimens under cyclic bending. Intact bones had significantly higher strain energies than locking plates in both bending and torsion. Locking and nonlocking plates were of equal strength and strain energy, but not stiffness, in bending and were of equal strength, stiffness, and strain energy in torsion. CONCLUSIONS AND CLINICAL RELEVANCE Results for this study suggested that increased torsional strength may be needed before bone plate repair can be considered as the sole fixation method for avian species.

  7. TWO-MODE GALERKIN APPROACH IN DYNAMIC STABILITY ANALYSIS OF VISCOELASTIC PLATES

    Institute of Scientific and Technical Information of China (English)

    张能辉; 程昌钧

    2003-01-01

    The dynamic stability of viscoelastic thin plates with large deflections was investigated by using the largest Liapunov exponent analysis and other numerical and analytical dynamic methods. The material behavior was described in terms of the Boltzmann superposition principle. The Galerkin method was used to simplify the original integropartial-differential model into a two-mode approximate integral model, which further reduced to an ordinary differential model by introducing new variables. The dynamic properties of one-mode and two-mode truncated systems were numerically compared. The influence of viscoelastic properties of the material, the loading amplitude and the initial values on the dynamic behavior of the plate under in-plane periodic excitations was discussed.

  8. Reproducibility of High-Throughput Plate-Reader Experiments in Synthetic Biology.

    Science.gov (United States)

    Chavez, Michael; Ho, Jonathan; Tan, Cheemeng

    2017-02-17

    Plate-reader assays are commonly conducted to quantify the performance of synthetic biological systems. However, on the basis of a survey of 100 publications, we find that most publications do not report critical experimental settings of plate reader assays, suggesting widespread issues in their reproducibility. Specifically, critical plate reader settings, including shaking time and covering method, either vary between laboratories or are not reported by the publications. Here, we demonstrate that the settings of plate reader assays have a significant impact on bacterial growth, recombinant gene expression, and biofilm formation. Furthermore, we show that the plate reader settings affect the apparent activity, sensitivity, and chemical kinetics of synthetic constructs, as well as alter the apparent effectiveness of antibiotics. Our results suggest the critical need for consistent reporting of plate reader protocols to ensure the reproducibility of the protocols. In addition, our work provides data for the setup of plate reader protocols in synthetic biology experiments.

  9. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    ’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  10. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  11. Linear stability analysis of fluid flow between two parallel porous stationary plates with small suction and injection

    CERN Document Server

    Hinvi, L A; Orou, J B Chabi

    2013-01-01

    In this work, the linear stability of the viscous incompressible fluid flow between two parallel horizontal porous stationary plates with the assumption that there is a small constant suction at upper plate and a small constant injection at the lower plate is studied.The Navier-Stokes and continuous equations are reduced to an equation modified by the suction Reynolds number, which we call modified Orr-Sommerfeld equation. This equation is rewritten as an eigenvalue problem and is solved numerically using Matlab (Windows Version). The effect of small suction Reynolds number on the linear stability fluid flow is discussed.

  12. Trapped Field Characteristics of Stacked YBCO Thin Plates for Compact NMR Magnets: Spatial Field Distribution and Temporal Stability.

    Science.gov (United States)

    Hahn, Seungyong; Kim, Seok Beom; Ahn, Min Cheol; Voccio, John; Bascuñán, Juan; Iwasa, Yukikazu

    2010-06-01

    This paper presents experimental and analytical results of trapped field characteristics of a stack of square YBCO thin film plates for compact NMR magnets. Each YBCO plate, 40 mm × 40 mm × 0.08 mm, has a 25-mm diameter hole at its center. A total of 500 stacked plates were used to build a 40-mm long magnet. Its trapped field, in a bath of liquid nitrogen, was measured for spatial field distribution and temporal stability. Comparison of measured and analytical results is presented: the effects on trapped field characteristics of the unsaturated nickel substrate and the non-uniform current distribution in the YBCO plate are discussed.

  13. Nonconforming stabilized combined finite element method for Reissner-Mindlin plate

    Institute of Scientific and Technical Information of China (English)

    Min-fu FENG; Yan YANG; Tian-xiao ZHOU

    2009-01-01

    Based on combination of two variational principles, a nonconforming sta-bilized finite element method is presented for the Reissner-Mindlin plates. The method is convergent when the finite element space is energy-compatible. Error estimates are derived. In particular, three finite element spaces are applied in the computation. Nu-merical results show that the method is insensitive to the mesh distortion and has better performence than the MITC4 and DKQ methods. With properly chosen parameters, high accuracy can be obtained at coarse meshes.

  14. ALICE EXPERIMENT Time of Flight Multigap Resistive Plate Chambers

    CERN Multimedia

    2003-01-01

    Charged particules are identified in ALICE by Time-Of-Flight (TOF); heavier particles are slower and it takes for them longer to reach the outer layers of the detector. For TOF system ALICE uses detectors called Multigap Resistive Plate Chambers (MRPC), like the prototype shown here.

  15. Finite element analysis of the stability of combined plate internal fixation in posterior wall fractures of acetabulum.

    Science.gov (United States)

    Liu, Xi-Ming; Pan, Chang-Wu; Wang, Guo-Dong; Cai, Xian-Hua; Chen, Lei; Meng, Cheng-Fei; Huang, Jin-Cheng

    2015-01-01

    This study aims to explore the mechanical stability of combined plate internal fixation in posterior wall fractures of the acetabulum. The fracture and internal fixation models were established in this study and they were divided into four kinds of internal fixation models, finite element analysis was performed. The four groups were 2 mini-plates and 1 reconstruction plate fixation (A), Reconstruction plate internal fixation group (B), 2 screws internal fixation group (C) and mini-plates internal fixation group (D). The displacement of each node was measured and evaluated. There was no distortion in the geometric shape of the finite element model. The results of stress showed that it was less in the anterior pelvic ring and distributed uniform in labrum acetabulare; the stress was bigger in the upper and middle of sacroiliac joint and sciatic notch in sitting position. Combined plate internal fixation for posterior wall fractures of acetabular were stable and reliable, it is better than the other three methods.

  16. Displaced proximal humeral fractures: an Indian experience with locking plates

    Directory of Open Access Journals (Sweden)

    Aggarwal Sameer

    2010-08-01

    Full Text Available Abstract Background The treatment of displaced proximal humerus fractures, especially in elderly, remains controversial. The objective of this study was to evaluate functional outcome of locking plate used for fixation of these fractures after open reduction. We also attempted to evaluate the complications and predictors of loss of fixation for such an implant. Methods Over two and a half years, 56 patients with an acute proximal humerus fracture were managed with locking plate osteosynthesis. 47 of these patients who completed a minimum follow up of 1 year were evaluated using Constant score calculation. Statistical analysis was done using SPSS 16 and a p value of less than 0.05 was taken as statistically significant. Results The average follow up period was around 21.5 months. Outcomes were excellent in 17%, good in 38.5%, moderate in 34% while poor in 10.5%. The Constant score was poorer for AO-OTA type 3 fractures as compared to other types. The scores were also inferior for older patients (> 65 years old. Complications included screw perforation of head, AVN, subacromial impingement, loss of fixation, axillary nerve palsy and infection. A varus malalignment was found to be a strong predictor of loss of fixation. Conclusion Locking plate osteosynthesis leads to satisfactory functional outcomes in all the patients. Results are better than non locking plates in osteoporotic fractures of the elderly. However the surgery has steep learning curve and various complications could be associated with its use. Nevertheless we believe that a strict adherence to the principles of locking plate use can ensure good result in such challenging fractures.

  17. Preliminary experience with Piccolo Composite™, a radiolucent distal fibula plate, in ankle fractures.

    Science.gov (United States)

    Caforio, Marco; Perugia, Dario; Colombo, Massimiliano; Calori, Giorgio Maria; Maniscalco, Pietro

    2014-12-01

    The radiolucent plate has many advantageous properties in the treatment of complex ankle fractures, particularly trimalleolar fractures. Surgeons may sometimes have difficulty observing the posterior malleolus after synthesis of lateral malleolus with a traditional plate because common materials of conventional plates are not radiolucent. In this study, the authors highlight the importance of the radiolucent property in the treatment of ankle fractures and describe their preliminary experience with a carbon fibre-reinforced polyetheretherketone distal fibula plate, with good results at 4 months' follow-up and no signs of tissue inflammatory reaction.

  18. Variables Affecting Smooth Particle Hydrodynamics Simulation of High-Velocity Flyer Plate Impact Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaram, Deepak S [UNLV; Trabia, Mohamed [UNLV; O' Toole, Brendan [UNLV; Hixson, Robert S [NSTec

    2014-01-23

    This paper describes our work to characterize the variables affecting the smoothed particle hydrodynamics (SPH) method in the LS-DYNA package for simulating high-velocity flyer plate impact experiments. LS-DYNA simulations are compared with one-dimensional experimental data of an oxygen-free high-conductivity (OFHC) copper flyer plate impacting another plate of the same material. The comparison is made by measuring the velocity of a point on the back surface of the impact plate using the velocity interferometer system for any reflector (VISAR) technique.

  19. Plate Shape Control Theory and Experiment for 20-high Mill

    Institute of Scientific and Technical Information of China (English)

    Zheng-wen YUAN; Hong XIAO

    2015-01-01

    Roll lfattening theory is an important part of plate shape control theories for 20-high mill. In order to improve the ac-curacy of roll lfattening calculation for 20-high mill, a new and more accurate roll lfattening model was proposed. In this model, the roll barrel was considered as a ifnite length semi-inifnite body. Based on the boundary integral equation method, the numerical solution of the ifnite length semi-inifnite body under the distributed force was obtained and an accurate roll lfattening model was established. Coupled with roll bending model and strip plastic deformation, a new and more accurate plate control model for 20-high mill was established. Moreover, the effects of the ifrst intermediate roll taper angle and taper length were analyzed. The ten-sion distribution calculated by analytical model was consistent with the experimental results.

  20. Plate Tectonics and Taiwan Orogeny based on TAIGER Experiments

    Science.gov (United States)

    Wu, F. T.; Kuochen, H.; McIntosh, K. D.

    2014-12-01

    Plate tectonics framework is usually complex in a collision zone, where continental lithosphere is involved. In the young Taiwan orogeny, with geologic understanding and large new geodetic and subsurface datasets now available an environment has been created for testing tectonic hypotheses regarding collision and orogeny. Against the background of the commonly accepted view of Taiwan as a southward propagating, self-similar 2-D orogen, a fully 3-D structure is envisaged. Along the whole length of the island the convergence of the Eurasian plate (EUP) the Philippine Sea plate (PSP) takes shape with different plate configurations. In northern Taiwan the convergence occurs with simultaneous collision of the oceanic PSP with continental EUP and the northward subduction of the PSP; in the south, EUP, in the guise of the South China Sea rifted Eurasian continent, subducts toward the east; in central Taiwan collision of oceanic PSP with continental EUP dominates. When relocated seismicity and focal mechanisms are superposed on subsurface P and Vp/Vs velocity images the configurations and the kinematics of the PSP and EUP collision and subduction become clear. While in northern Taiwan the subduction/collision explains well the high peaks and their dwindling (accompanied by crustal thinning) toward the north. In the south, mountains rise above the east-dipping EUP subduction zone as the Eurasian continental shelf veers toward the southwest, divergent from the trend of the Luzon Arc - calling into question the frequently cited arc-continent collision model of Taiwan orogeny. High velocity anomaly and Benioff seismicity coexist in the south. Going north toward Central Taiwan the high velocity anomaly persists for another 150 km or so, but it becomes seismically quiescent. Above the quiescent section the PSP and EUP collide to build the main part of the Central Range and its parallel neighbor the eastern Coastal Range. Key implications regarding orogeny include: 1) Significant

  1. Quasi-Stability of the Primary Flow in a Cone and Plate Viscometer

    Science.gov (United States)

    Azerad, Pascal; Bänsch, Eberhard

    We investigate the flow between a shallow rotating cone and a stationary plate. This cone and plate device is used in rheometry, haemostasis as well as in food industry to study the properties of the flow w.r.t. shear stress. Physical experiments and formal computations show that close to the apex the flow is approximately azimuthal and the shear-stress is constant within the device, the quality of the approximation being controlled essentially by the single parameter Re ɛ2, where Re is the Reynolds number and ɛ the thinness of the cone-plate gap. We establish this fact by means of rigorous energy estimates and numerical simulations. Surprisingly enough, this approximation is valid though the primary flow is not itself a solution of the Navier-Stokes equations, and it does not even fulfill the correct boundary conditions, which are in this particular case discontinuous along a line, thus not allowing for a usual Leray solution. To overcome this difficulty we construct a suitable corrector.

  2. Local Projection-Based Stabilized Mixed Finite Element Methods for Kirchhoff Plate Bending Problems

    Directory of Open Access Journals (Sweden)

    Xuehai Huang

    2013-01-01

    Full Text Available Based on stress-deflection variational formulation, we propose a family of local projection-based stabilized mixed finite element methods for Kirchhoff plate bending problems. According to the error equations, we obtain the error estimates of the approximation to stress tensor in energy norm. And by duality argument, error estimates of the approximation to deflection in H1-norm are achieved. Then we design an a posteriori error estimator which is closely related to the equilibrium equation, constitutive equation, and nonconformity of the finite element spaces. With the help of Zienkiewicz-Guzmán-Neilan element spaces, we prove the reliability of the a posteriori error estimator. And the efficiency of the a posteriori error estimator is proved by standard bubble function argument.

  3. Anterior decompression, structural bone grafting, and Caspar plate stabilization for unstable cervical spine fractures and/or dislocations.

    Science.gov (United States)

    Garvey, T A; Eismont, F J; Roberti, L J

    1992-10-01

    Fourteen patients who sustained acute cervical spine fractures and/or dislocations with associated posterior ligamentous disruption had anterior decompressions, structural bone grafting, and anterior Caspar plate stabilization. With an average 30-month follow-up, no patient has had loss of fixation. Despite criticism raised from biomechanical testing, the Caspar anterior plate system (Aesculape, Tuttlingen, Germany) may be added to structural bone grafting of unstable cervical fractures and/or dislocations, yielding an in vivo solid construct, which obviates the need for simultaneous posterior stabilization.

  4. Experience with the BaBar Resistive Plate Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Band, H.

    2005-04-06

    The BaBar detector has operated over 2000 m{sup 2} of Resistive Plates Chambers (RPCs) as muon and neutral hadron detectors since 1999. Most of the original RPC production have lost significant efficiency and many are now completely inefficient. Both the linseed oil used to coat the inner surfaces and the graphite coating on the outer surfaces are implicated as contributors to the efficiency loss which was accelerated by the operation of the RPCs at 29 to 34 C during the first summer. RPCs from 2 more recent production runs have been installed and tested. The most recent RPCs have exhibited stable efficiencies and high voltage plateaus during the first 8 months of service. Some have shown increased dark currents and noise rates.

  5. Analysis of the ORNL/TSF GCFR Grid-Plate Shield Design Confirmation Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Slater, C.O.; Cramer, S.N.; Ingersoll, D.T.

    1979-08-01

    The results of the analysis of the GCFR Grid-Plate Shield Design Confirmation Experiment are presented. The experiment, performed at the ORNL Tower Shielding Facility, was designed to test the adequacy of methods and data used in the analysis of the GCFR design. In particular, the experiment tested the adequacy of methods to calculate: (1) axial neutron streaming in the GCFR core and axial blanket, (2) the amount and location of the maximum fast-neutron exposure to the grid plate, and (3) the neutron source leaving the top of the grid plate and entering the upper plenum. Other objectives of the experiment were to verify the grid-plate shielding effectiveness and to assess the effects of fuel-pin and subassembly spacing on radiation levels in the GCFR. The experimental mockups contained regions representing the GCFR core/blanket region, the grid-plate shield section, and the grid plate. Most core design options were covered by allowing: (1) three different spacings between fuel subassemblies, (2) two different void fractions within a subassembly by variation of the number of fuel pins, and (3) a mockup of a control-rod channel.

  6. Quasi-one-dimensional modes in strip plates: Theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Arreola, A.; Báez, G. [Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana-Azcapotzalco, Apartado Postal 21-267, 04000 México Distrito Federal (Mexico); Méndez-Sánchez, R. A. [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62251 Cuernavaca, Morelos (Mexico)

    2014-01-14

    Using acoustic resonance spectroscopy we measure the elastic resonances of a strip rectangular plate with all its ends free. The experimental setup consist of a vector network analyzer, a high-fidelity audio amplifier, and electromagnetic-acoustic transducers. The one-dimensional modes are identified from the measured spectra by comparing them with theoretical predictions of compressional and bending modes of the plate modeled as a beam. The agreement between theory and experiment is excellent.

  7. Comminuted supracondylar femoral fractures: a biomechanical analysis comparing the stability of medial versus lateral plating in axial loading

    Directory of Open Access Journals (Sweden)

    Nikolai Briffa

    2016-10-01

    Full Text Available Abstract The aim of this study was to compare the biomechanical properties of medial and lateral plating of a medially comminuted supracondylar femoral fracture. A supracondylar femoral fracture model comparing two fixation methods was tested cyclically in axial loading. One-centimetre supracondylar gap osteotomies were created in six synthetic femurs approximately 6 cm proximal to the knee joint. There were two constructs investigated: group 1 and group 2 were stabilized with an 8-hole LC-DCP, medially and laterally, respectively. Both construct groups were axially loaded. Global displacement (total length, wedge displacement, bending moment and strain were measured. Medial plating showed a significantly decreased displacement, bending moment and strain at the fracture site in axial loading. Medial plating of a comminuted supracondylar femur fracture is more stable than lateral plating.

  8. Vibration, Stability, and Resonance of Angle-Ply Composite Laminated Rectangular Thin Plate under Multiexcitations

    Directory of Open Access Journals (Sweden)

    M. Sayed

    2013-01-01

    Full Text Available An analytical investigation of the nonlinear vibration of a symmetric cross-ply composite laminated piezoelectric rectangular plate under parametric and external excitations is presented. The method of multiple time scale perturbation is applied to solve the nonlinear differential equations describing the system up to and including the second-order approximation. All possible resonance cases are extracted at this approximation order. The case of 1 : 1 : 3 primary and internal resonance, where Ω3≅ω1, ω2≅ω1, and ω3≅3ω1, is considered. The stability of the system is investigated using both phase-plane method and frequency response curves. The influences of the cubic terms on nonlinear dynamic characteristics of the composite laminated piezoelectric rectangular plate are studied. The analytical results given by the method of multiple time scale is verified by comparison with results from numerical integration of the modal equations. Reliability of the obtained results is verified by comparison between the finite difference method (FDM and Runge-Kutta method (RKM. It is quite clear that some of the simultaneous resonance cases are undesirable in the design of such system. Such cases should be avoided as working conditions for the system. Variation of the parameters μ1, μ2, α7,β8, ω1, ω2, f1, f2 leads to multivalued amplitudes and hence to jump phenomena. Some recommendations regarding the different parameters of the system are reported. Comparison with the available published work is reported.

  9. Additive fiber-cerclages in proximal humeral fractures stabilized by locking plates: no effect on fracture stabilization and rotator cuff function in human shoulder specimens.

    Science.gov (United States)

    Voigt, Christine; Hurschler, Christof; Rechi, Louise; Vosshenrich, Rolf; Lill, Helmut

    2009-08-01

    The effect of additive fiber-cerclages in proximal humeral fractures stabilized by locking plates on fracture stabilization and rotator cuff function is unclear. Here it was assessed in a human cadaver study. 24 paired human shoulder specimens were harvested from median 77-year-old (range 66-85) female donors. An unstable 3-part fracture model with an intact rotator cuff was developed. 1 specimen of each pair received an additive fiber-cerclage of the rotator cuff after plate fixation, and the other one received a plate fixation without an additive fiber-cerclage. Force-controlled hydraulic cylinders were used to simulate physiological rotator cuff tension, while a robot-assisted shoulder simulator performed 4 relevant cases of load: (1) axial loading at 0 degrees, (2) glenohumeral abduction at 60 degrees, (3) internal rotation at 0 degrees abduction, and (4) external rotation at 0 degrees abduction, and imitated hanging arm weight during loading without affecting joint kinematics. A 3-dimensional real-time interfragmentary motion analysis was done in fracture gaps between the greater tuberosity and the head, as well as subcapital. The capacity of the rotator cuff to strain was analyzed with an optical system. Interfragmentary motion was similar between the groups with and without fiber-cerclages, in both fracture gaps and in any of the cases of load. Cerclages did not impair the capacity of the rotator cuff to strain. INTERPRETATION; Provided that unstable 3-part fractures are reduced and stabilized anatomically by a locking plate, additive fiber-cerclages do not reduce interfragmentary motion. Additive fiber-cerclages may be necessary in locking plate osteosyntheses of multiple-fractured greater tuberosities or lesser tuberosity fractures that cannot be fixed sufficiently by the plate.

  10. Elastic stability of superplastically formed/diffusion-bonded orthogonally corrugated core sandwich plates

    Science.gov (United States)

    Ko, W. L.

    1980-01-01

    The paper concerns the elastic buckling behavior of a newly developed superplastically formed/diffusion-bonded (SPF/DB) orthogonally corrugated core sandwich plate. Uniaxial buckling loads were calculated for this type of sandwich plate with simply supported edges by using orthotropic sandwich plate theory. The buckling behavior of this sandwich plate was then compared with that of an SPF/DB unidirectionally corrugated core sandwich plate under conditions of equal structural density. It was found that the buckling load for the former was considerably higher than that of the latter.

  11. Accelerating Vaccine Formulation Development Using Design of Experiment Stability Studies.

    Science.gov (United States)

    Ahl, Patrick L; Mensch, Christopher; Hu, Binghua; Pixley, Heidi; Zhang, Lan; Dieter, Lance; Russell, Ryann; Smith, William J; Przysiecki, Craig; Kosinski, Mike; Blue, Jeffrey T

    2016-10-01

    Vaccine drug product thermal stability often depends on formulation input factors and how they interact. Scientific understanding and professional experience typically allows vaccine formulators to accurately predict the thermal stability output based on formulation input factors such as pH, ionic strength, and excipients. Thermal stability predictions, however, are not enough for regulators. Stability claims must be supported by experimental data. The Quality by Design approach of Design of Experiment (DoE) is well suited to describe formulation outputs such as thermal stability in terms of formulation input factors. A DoE approach particularly at elevated temperatures that induce accelerated degradation can provide empirical understanding of how vaccine formulation input factors and interactions affect vaccine stability output performance. This is possible even when clear scientific understanding of particular formulation stability mechanisms are lacking. A DoE approach was used in an accelerated 37(°)C stability study of an aluminum adjuvant Neisseria meningitidis serogroup B vaccine. Formulation stability differences were identified after only 15 days into the study. We believe this study demonstrates the power of combining DoE methodology with accelerated stress stability studies to accelerate and improve vaccine formulation development programs particularly during the preformulation stage. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  12. Early experience with medial femoral tension band plating in idiopathic genu valgum.

    Science.gov (United States)

    Guzman, Humberto; Yaszay, Burt; Scott, Vanessa P; Bastrom, Tracey P; Mubarak, Scott J

    2011-02-01

    For correction of angular deformity, tension band plating has been proposed as a safe and minimally invasive technique. The purpose of this study was to assess the experiences and report the rate of correction obtained with this procedure in patients with idiopathic genu valgum. This study was a retrospective review of 47 valgus deformities of the knee treated with medial hemiepiphysiodesis using a tension band plate. The tibiofemoral angle (TFA) and the anatomic lateral distal femoral angle (aLDFA) were assessed on anteroposterior (AP) radiographs of the lower extremity taken at multiple time intervals. The values were charted to determine the change in orientation of the joint surface over time. Pearson's correlation was used to analyze the correction over time. A subanalysis was performed evaluating the effect of age and the number of plates utilized. A total of 47 deformities in 25 patients were reviewed. The average time of follow-up from index surgery was 12.7 months, with an average correction of 0.96° every 3 months or 3.8° per year. The aLDFA corrected at a faster rate in knees with two plates per hemiepiphysiodesis than those with one plate, 4.2° and 3.3° per year, respectively (P = 0.035). Girls genu valgum. Two plates appear to provide a greater rate of correction. There is also a trend toward faster correction in younger patients as well.

  13. A Didactic Experiment and Model of a Flat-Plate Solar Collector

    Science.gov (United States)

    Gallitto, Aurelio Agliolo; Fiordilino, Emilio

    2011-01-01

    We report on an experiment performed with a home-made flat-plate solar collector, carried out together with high-school students. To explain the experimental results, we propose a model that describes the heating process of the solar collector. The model accounts quantitatively for the experimental data. We suggest that solar-energy topics should…

  14. Parameters optimization of high stability bath for electroless copper plating%高稳定性化学镀铜液的参数优化

    Institute of Scientific and Technical Information of China (English)

    杨超; 陈金菊; 冯哲圣; 王大勇; 薛文明

    2014-01-01

    The stability of bath, the speed and the brightness of coating were taken as indexes to optimize the bath of electroless copper plating through the single factor experiment method. Electrochemical test of plating solution was done to study the influence of additives on polarization performance of bath. The stability of solution decreases with the concentration of CuSO4·5H2O and HCHO increasing. The addition of appropriate complexing agent and stabilizers can effectively increase the stability of the plating solution. The copper deposition rate reaches to 4.93μm/h for plating 30 min. The stable time of plating bath is more than two hours in 80℃ water bath. Copper layer appears shiny pale pink, and copper particles are close together. The magnitude of copper layer resistivity is 3.67×10-8Ω·m. The adhesion strength between copper layer and substrate is up to 10 N/mm2.%采用单因素实验法,以镀液稳定性、镀速及镀层光亮度为指标,优化了化学镀铜液参数以提高镀液稳定性,并研究了添加剂对镀液电化学极化性能的影响。试验结果表明:随着CuSO4·5H2O和HCHO浓度的增加,镀液稳定性有所下降;适量的络合剂和稳定剂的加入能有效提高镀液稳定性。采用优化后的镀液施镀30 min,镀速为4.93μm/h;施镀后的镀液在80℃水浴中的稳定时间大于2 h;所得铜层为具有金属光泽的淡粉红色,铜颗粒排列紧密;镀铜层电阻率低至3.67×10-8Ω·m,铜层与基体之间的附着强度提高至10 N/mm2。

  15. A large aperture reflective wave-plate for high-intensity short-pulse laser experiments

    CERN Document Server

    Aurand, Bastian; Zhao, Huanyu; Kuschel, Stephan; Wünsche, Martin; Jäckel, Oliver; Heyer, Martin; Wunderlich, Frank; Kaluza, Malte C; Paulus, Gerhard G; Kuehl, Thomas

    2012-01-01

    We report on a reflective wave-plate system utilizing phase-shifting mirrors (PSM) for a continuous variation of elliptical polarization without changing the beam position and direction. The scalability of multilayer optics to large apertures and the suitability for high-intensity broad-bandwidth laser beams make reflective wave-plates an ideal tool for experiments on relativistic laser-plasma interaction. Our measurements confirm the preservation of the pulse duration and spectrum when a 30-fs Ti:Sapphire laser beam passes the system.

  16. Metatarsophalangeal joint stability: A systematic review on the plantar plate of the lesser toes

    NARCIS (Netherlands)

    Maas, N.M.G. (Nico M.G.); M. van der Grinten (Margot); W.M. Bramer (Wichor); G.J. Kleinrensink (Gert Jan)

    2016-01-01

    textabstractBackground: Instability of the metatarsophalangeal (MTP) joints of the lesser toes (digiti 2-5) is increasingly being treated by repair of the plantar plate (PP). This systematic review examines the anatomy of the plantar plate of the lesser toes, and the relation between the integrity

  17. Metatarsophalangeal joint stability: A systematic review on the plantar plate of the lesser toes

    NARCIS (Netherlands)

    Maas, N.M.G. (Nico M.G.); M. van der Grinten (Margot); W.M. Bramer (Wichor); G.J. Kleinrensink (Gert Jan)

    2016-01-01

    textabstractBackground: Instability of the metatarsophalangeal (MTP) joints of the lesser toes (digiti 2-5) is increasingly being treated by repair of the plantar plate (PP). This systematic review examines the anatomy of the plantar plate of the lesser toes, and the relation between the integrity o

  18. Metatarsophalangeal joint stability: A systematic review on the plantar plate of the lesser toes

    NARCIS (Netherlands)

    Maas, N.M.G. (Nico M.G.); M. van der Grinten (Margot); W.M. Bramer (Wichor); G.J. Kleinrensink (Gert Jan)

    2016-01-01

    textabstractBackground: Instability of the metatarsophalangeal (MTP) joints of the lesser toes (digiti 2-5) is increasingly being treated by repair of the plantar plate (PP). This systematic review examines the anatomy of the plantar plate of the lesser toes, and the relation between the integrity o

  19. HIP experiments on the first wall and cooling plate specimens for the EU HCPB blanket

    Energy Technology Data Exchange (ETDEWEB)

    Norajitra, P. E-mail: prachai.norajitra@imf.fzk.de; Reimann, G.; Ruprecht, R.; Schaefer, L

    2002-12-01

    First wall and cooling plates are considered the most important structural parts of the EU HCPB blanket concept which is based on the use of ferritic-martensitic steel as structural material, Li{sub 4}SiO{sub 4} pebbles as breeder material, beryllium pebbles as neutron multiplier, and 8 MPa helium as coolant. Both the first wall and cooling plates contain complex arrays of internal He coolant channels. The favourite manufacturing technology is diffusion welding of two halves of plates applying the hot isostatic pressure (HIP) welding method that allows uniform distribution of the pressure acting on the outer surfaces of the welding objects. The HIP experiment was started with small MANET specimens with internal coolant channels. The objective of this work is to investigate the appropriate HIP technique, boundary conditions, and parameters in order to achieve good mechanical properties of the welding joints as well as to achieve a transition to test specimens of larger dimensions.

  20. Stability mechanisms for plate-like nanoparticles immersed in a macroion dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Angeles, Felipe; Odriozola, Gerardo; Lozada-Cassou, Marcelo [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Lazaro Cardenas 152, 07730 Mexico, DF (Mexico)

    2009-10-21

    An integral equation theory and Monte Carlo simulations are applied to study a model macroion solution confined between two parallel plates immersed in a 1:1 electrolyte and the macroions' counterions. We analyze the cases in which plates are: (a) uncharged; (b) when they are like-charged to the macroions; (c) when they are oppositely charged to the macroions. For all cases a long range oscillatory behavior of the induced charge density between the plates is found (implying an overcompensation/undercompensation of the plates' charge density) and a correlation between the confined and outside fluids. The behavior of the force is discussed in terms of the macroion and ion structure inside and outside the plates. A good agreement is found between theoretical and simulation results.

  1. Experimental study on the stability of plate anchors in clay under cyclic loading

    Directory of Open Access Journals (Sweden)

    Long Yu

    2015-03-01

    Full Text Available Although the bearing capacity of plate anchors in clay has been studied extensively, the results considering the effects of offshore cyclic loading are relatively rare. In the present study, 1 g model tests are carried out to investigate the effect of cyclic loading on the bearing capacity of plate anchors in clay. The ultimate pullout capacity of plate anchors in clay decreases as the accumulated plastic shear strain grows due to the strain-softening of clay under cyclic loading. The load–displacement curves of these tests are presented and the effects of overburden stress and cyclic loading amplitude on the strain-softening behavior are discussed.

  2. Nonlinear and chaotic vibration and stability analysis of an aero-elastic piezoelectric FG plate under parametric and primary excitations

    Science.gov (United States)

    Rezaee, Mousa; Jahangiri, Reza

    2015-05-01

    In this study, in the presence of supersonic aerodynamic loading, the nonlinear and chaotic vibrations and stability of a simply supported Functionally Graded Piezoelectric (FGP) rectangular plate with bonded piezoelectric layer have been investigated. It is assumed that the plate is simultaneously exposed to the effects of harmonic uniaxial in-plane force and transverse piezoelectric excitations and aerodynamic loading. It is considered that the potential distribution varies linearly through the piezoelectric layer thickness, and the aerodynamic load is modeled by the first order piston theory. The von-Karman nonlinear strain-displacement relations are used to consider the geometrical nonlinearity. Based on the Classical Plate Theory (CPT) and applying the Hamilton's principle, the nonlinear coupled partial differential equations of motion are derived. The Galerkin's procedure is used to reduce the equations of motion to nonlinear ordinary differential Mathieu equations. The validity of the formulation for analyzing the Limit Cycle Oscillation (LCO), aero-elastic stability boundaries is accomplished by comparing the results with those of the literature, and the convergence study of the FGP plate is performed. By applying the Multiple Scales Method, the case of 1:2 internal resonance and primary parametric resonance are taken into account and the corresponding averaged equations are derived and analyzed numerically. The results are provided to investigate the effects of the forcing/piezoelectric detuning parameter, amplitude of forcing/piezoelectric excitation and dynamic pressure, on the nonlinear dynamics and chaotic behavior of the FGP plate. It is revealed that under the certain conditions, due to the existence of bi-stable region of non-trivial solutions, system shows the hysteretic behavior. Moreover, in absence of airflow, it is observed that variation of control parameters leads to the multi periodic and chaotic motions.

  3. One-dimensional plate impact experiments on the cyclotetramethylene tetranitramine (HMX) based explosive EDC32

    Science.gov (United States)

    Burns, Malcolm J.; Gustavsen, Richard L.; Bartram, Brian D.

    2012-09-01

    Eight one-dimensional plate impact experiments have been performed to study both the Shock to Detonation Transition and Hugoniot state in the cyclotetramethylene tetranitramine (HMX) based explosive EDC32. The experiments covered shock pressures ranging from 0.59 to 7.5 GPa with sustained shocks, double shocks, and short pulse shocks. Experiments were instrumented with embedded magnetic particle velocity gauges. Results include; (1) wave profiles of particle velocity vs. time vs. depth in the explosive, (2) time-distance coordinates for onset of detonation vs. initial shock pressure (aka the Pop-plot), (3) a reactants Hugoniot, and (4) measurement of the Hugoniot Elastic Limit of 0.22.GPa.

  4. Mechanisms of stabilization and blowoff of a premixed flame downstream of a heat-conducting perforated plate

    KAUST Repository

    Kedia, Kushal S.

    2012-03-01

    The objective of this work is to investigate the flame stabilization mechanism and the conditions leading to the blowoff of a laminar premixed flame anchored downstream of a heat-conducting perforated-plate/multi-hole burner, with overall nearly adiabatic conditions. We use unsteady, fully resolved, two-dimensional simulations with detailed chemical kinetics and species transport for methane-air combustion. Results show a bell-shaped flame stabilizing above the burner plate hole, with a U-shaped section anchored between neighboring holes. The base of the positively curved U-shaped section of the flame is positioned near the stagnation point, at a location where the flame displacement speed is equal to the flow speed. This location is determined by the combined effect of heat loss and flame stretch on the flame displacement speed. As the mass flow rate of the reactants is increased, the flame displacement speed at this location varies non-monotonically. As the inlet velocity is increased, the recirculation zone grows slowly, the flame moves downstream, and the heat loss to the burner decreases, strengthening the flame and increasing its displacement speed. As the inlet velocity is raised, the stagnation point moves downstream, and the flame length grows to accommodate the reactants mass flow. Concomitantly, the radius of curvature of the flame base decreases until it reaches an almost constant value, comparable to the flame thickness. While the heat loss decreases, the higher flame curvature dominates thereby reducing the displacement speed of the flame base. For a stable flame, the gradient of the flame base displacement speed normal to the flame is higher than the gradient of the flow speed along the same direction, leading to dynamic stability. As inlet velocity is raised further, the former decreases while the latter increases until the stability condition is violated, leading to blowoff. The flame speed during blow off is determined by the feedback between the

  5. Recent experimental results and developments on the resistive plate chambers for the CMS experiment

    CERN Document Server

    Altieri, S; Bruno, G; Guida, R; Merlo, M; Ratti, S P; Riccardi, C; Torre, P; Vitulo, P; Abbrescia, M; Colaleo, A; Iaselli, Giuseppe; Loddo, F; Maggi, M; Marangelli, B; Natali, S; Nuzzo, S; Pugliese, G; Ranieri, A; Romano, F

    2001-01-01

    Resistive plate chambers (RPC) have been chosen as dedicated trigger detectors for the CMS experiment at the LHC. The expected severe operating conditions have required an intense research and development activity on these detectors over the past years. Experimental results on overall performance of large chambers, rate capability, ageing and photon sensitivity are reviewed. In all of these tests the detector has proven to achieve good enough performance for successful use at the LHC. (6 refs).

  6. Surface stability and conductivity of a high Cr and Ni austenitic stainless steel plates for PEMFC

    Institute of Scientific and Technical Information of China (English)

    TIAN Rujin; SUN Juncai; WANG Jianli

    2006-01-01

    In order to use stainless steel as bipolar plate for PEMFC, electrochemical behavior of a high Cr and Ni austenitic stainless steel was studied in the solutions containing different concentration of H2SO4 and 2 mg·L-1 F-, and interfacial contact resistance was measured after corrosion tests. The experimental results show that the passive current density lowers with decreasing the concentration of H2SO4. The interfacial contact resistance between carbon paper and passive film formed in the simulated PEMFC environment is higher than the goal of bipolar plate for PEMFC. Surface conductivity should be further reduced by surface modification.

  7. A Study of the Effect of Gold Thickness Distribution in the Jet Plating Process to Optimize Gold Usage and Plating Voltage Using Design of Experiments

    OpenAIRE

    Aramphongphun Chuckaphun; Nampanya Chalermpol

    2016-01-01

    A gold plating process in the electronics industry can be classified as (i) all surface plating or (ii) selective plating. Selective plating is more widely used than all surface plating because it can save more gold used in the plating process and takes less plating time. In this research, the selective plating process called jet plating was studied. Factors that possibly affected the gold usage and plating voltage were also studied to reduce the production cost. These factors included (a) pl...

  8. Structural Stability and Dynamics of FGM Plates Using an Improved 8-ANS Finite Element

    Directory of Open Access Journals (Sweden)

    Weon-Tae Park

    2016-01-01

    Full Text Available I investigate the vibration and buckling analysis of functionally graded material (FGM structures, using a modified 8-node shell element. The properties of FGM vary continuously through the thickness direction according to the volume fraction of constituents defined by sigmoid function. The modified 8-ANS shell element has been employed to study the effect of power law index on dynamic analysis of FGM plates with various boundary conditions and buckling analysis under combined loads, and interaction curves of FGM plates are carried out. To overcome shear and membrane locking problems, the assumed natural strain method is employed. In order to validate and compare the finite element numerical solutions, the reference results of plates based on Navier’s method, the series solutions of sigmoid FGM (S-FGM plates are compared. Results of the present study show good agreement with the reference results. The solutions of vibration and buckling analysis are numerically illustrated in a number of tables and figures to show the influence of power law index, side-to-thickness ratio, aspect ratio, types of loads, and boundary conditions in FGM structures. This work is relevant to the simulation of wing surfaces, aircrafts, and box structures under various boundary conditions and loadings.

  9. Payload isolation and stabilization by a Suspended Experiment Mount (SEM)

    Science.gov (United States)

    Bailey, Wayne L.; Desanctis, Carmine E.; Nicaise, Placide D.; Schultz, David N.

    1992-01-01

    Many Space Shuttle and Space Station payloads can benefit from isolation from crew or attitude control system disturbances. Preliminary studies have been performed for a Suspended Experiment Mount (SEM) system that will provide isolation from accelerations and stabilize the viewing direction of a payload. The concept consists of a flexible suspension system and payload-mounted control moment gyros. The suspension system, which is rigidly locked for ascent and descent, isolates the payload from high frequency disturbances. The control moment gyros stabilize the payload orientation. The SEM will be useful for payloads that require a lower-g environment than a manned vehicle can provide, such as materials processing, and for payloads that require stabilization of pointing direction, but not large angle slewing, such as nadir-viewing earth observation or solar viewing payloads.

  10. Stability and Bifurcation for a Simply Supported Functionally Graded Material Plate with One-to-One Internal Resonance

    Directory of Open Access Journals (Sweden)

    Dongmei Zhang

    2014-01-01

    Full Text Available Stability and bifurcation behaviors for a model of simply supported functionally graded materials rectangular plate subjected to the transversal and in-plane excitations are studied by means of combination of analytical and numerical methods. The resonant case considered here is 1 : 1 internal resonances and primary parametric resonance. Two types of degenerated equilibrium points are studied in detail, which are characterized by a double zero and two negative eigenvalues, and a double zero and a pair of pure imaginary eigenvalues. For each case, the stability regions of the initial equilibrium solution and the critical bifurcation curves are obtained in terms of the system parameters which may lead to Hopf bifurcation and 2D torus. With both analytical and numerical methods, bifurcation behaviors on damping parameters and detuning parameters are studied, respectively. A time integration scheme is used to find the numerical solutions for these bifurcation cases, and numerical results agree with the analytic predictions.

  11. Force sensor for chameleon and Casimir force experiments with parallel-plate configuration

    CERN Document Server

    Almasi, Attaallah; Iannuzzi, Davide; Sedmik, René I P

    2015-01-01

    The search for non-Newtonian forces has been pursued following many different paths. Recently it was suggested that hypothetical chameleon interactions, which might explain the mechanisms behind dark energy, could be detected in a high-precision force measurement. In such an experiment, interactions between parallel plates kept at constant separation could be measured as a function of the pressure of an ambient gas, thereby identifying chameleon interactions by their unique inverse dependence on the local mass density. During the past years we have been developing a new kind of setup complying with the high requirements of the proposed experiment. In this article we present the first and most important part of this setup -- the force sensor. We discuss its design, fabrication, and characterization. From the results of the latter we derive limits on chameleon interaction parameters that could be set by the forthcoming experiment. Finally, we describe the opportunity to use the same setup to measure Casimir for...

  12. Single time point isothermal drug stability experiments at constant humidity.

    Science.gov (United States)

    Tao, Jian-Lin; Zhan, Xian-Cheng; Li, Lin-Li; Lin, Bing; Jiang, Lu

    2009-03-01

    A single time point isothermal drug stability experiments at constant humidity is introduced. In the new method, kinetic parameters related to both moisture and temperature were obtained by a single pair of experiments: these related to moisture by one with a group of testing humidities and a fixed temperature, those related to temperature by the other with a group of testing temperatures and a constant humidity. By a simulation, the estimates for the kinetic parameters (E(a), m, A) obtained by the proposed method and the reported programmed humidifying and heating method were statistically evaluated and were compared with those obtained by the isothermal measurements at constant humidity. Results indicated that under the same experimental conditions, the estimates obtained by the proposed method were significantly more precise than those obtained by the reported programmed humidifying and heating method. The estimates obtained by the isothermal method at constant humidity were somewhat more precise than those obtained by the proposed method. However, the experimental period needed by the isothermal method at constant humidity was greatly longer than that needed by the proposed method. The stability of dicloxacillin sodium, as a solid state model, was investigated by the single time point isothermal drug stability experiments at constant humidity. The results indicated that the kinetic parameters obtained by the proposed method were comparable to those from the reported.

  13. The Application of a Smartphone in Ship Stability Experiment

    Institute of Scientific and Technical Information of China (English)

    Mohamed Abdelkader Djebli; Benameur Hamoudi; Omar Imine; Lahouari Adjlout

    2015-01-01

    The inclining experiment is the only regulatory tool to assess ship stability. This experiment is a time consuming process for both real-life tests and ship model experiments. The difficulty is mainly due to a bias in the measurement of heel angle. Nowadays, digital inclinometers are available, but they are expensive. In this study, the use of a smartphone application is presented for ship inclination and rolling-period tests. The idea consists of using accelerometer and gyroscope sensors built into the current smartphones for the measurements. Therefore, some experiments are carried out on an example trawler model to exhibit the uses and advantages of this method. The obtained results are in good agreement with those provided from the pendulum method and natural roll-period test. This application is new, easy, and more accurately assesses metacentric height during the inclining and rolling-period tests.

  14. Victimization Experiences and the Stabilization of Victim Sensitivity

    Directory of Open Access Journals (Sweden)

    Mario eGollwitzer

    2015-04-01

    Full Text Available People reliably differ in the extent to which they are sensitive to being victimized by others. Importantly, victim sensitivity predicts how people behave in social dilemma situations: Victim-sensitive individuals are less likely to trust others and more likely to behave uncooperatively - especially in socially uncertain situations. This pattern can be explained with the Sensitivity to Mean Intentions (SeMI model, according to which victim sensitivity entails a specific and asymmetric sensitivity to contextual cues that are associated with untrustworthiness. Recent research is largely in line with the model’s prediction, but some issues have remained conceptually unresolved so far. For instance, it is unclear why and how victim sensitivity becomes a stable trait and which developmental and cognitive processes are involved in such stabilization. In the present article, we will discuss the psychological processes that contribute to a stabilization of victim sensitivity within persons, both across the life span (ontogenetic stabilization and across social situations (actual-genetic stabilization. Our theoretical framework starts from the assumption that experiences of being exploited threaten a basic need, the need to trust. This need is so fundamental that experiences that threaten it receive a considerable amount of attention and trigger strong affective reactions. Associative learning processes can then explain (a how certain contextual cues (e.g., facial expressions become conditioned stimuli that elicit equally strong responses, (b why these contextual untrustworthiness cues receive much more attention than, for instance, trustworthiness cues, and (c how these cues shape spontaneous social expectations (regarding other people’s intentions. Finally, avoidance learning can explain why these cognitive processes gradually stabilize and become a trait: the trait which is referred to as victim sensitivity.

  15. Numerical analysis of the stability of the electrohydrodynamic (EHD) electroconvection between two plates

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, P A; Castellanos, A [Dpto de Electronica y Electromagnetismo, Facultad de Fisica, Avda Reina Mercedes s/n, 41012 Sevilla (Spain); Georghiou, G E [Department of Electrical and Computer Engineering, University of Cyprus, 1678 Nicosia (Cyprus)], E-mail: pvazquez@us.es

    2008-09-07

    The time evolution of the problem of electrohydrodynamic convection in a liquid between two plates is analysed numerically. The equations are non-dimensionalized using the ion drift velocity and the viscous time scales. Following the non-dimensionalization of the respective model, two different techniques have been used to describe the charge evolution, namely, the finite-element flux-corrected transport method and the particle-in-cell technique. The results obtained with the two schemes, apart from showing good agreement, have revealed the appearance of a two-roll structure not described in previous works. This is investigated in detail for both strong and weak injection.

  16. Optimization of the half wave plate configuration for the LSPE-SWIPE experiment

    Science.gov (United States)

    Buzzelli, A.; de Gasperis, G.; de Bernardis, P.; Masi, S.; Vittorio, N.

    2017-05-01

    The search for the B-mode polarization of Cosmic Microwave Background (CMB) is the new frontier of observational Cosmology. A B-mode detection would give an ultimate confirmation to the existence of a primordial Gravitational Wave (GW) background as predicted in the inflationary scenario. Several experiments have been designed or planned to observe B-modes. In this work we focus on the forthcoming Large Scale Polarization Explorer (LSPE) experiment, that will be devoted to the accurate measurement of CMB polarization at large angular scales. LSPE consists of a balloon-borne bolometric instrument, the Short Wavelength Instrument for the Polarization Explorer (SWIPE), and a ground-based coherent polarimeter array, the STRatospheric Italian Polarimeter (STRIP). SWIPE will employ a rotating Half Wave Plate (HWP) polarization modulator to mitigate the systematic effects due to instrumental non-idealities. We present here preliminary forecasts aimed at optimizing the HWP configuration.

  17. Stability and coherent structures of the asymptotic suction boundary layer over a heated plate

    CERN Document Server

    Zammert, Stefan; Eckhardt, Bruno

    2016-01-01

    The asymptotic suction boundary layer (ASBL) is a parallel shear flow that becomes turbulent in a bypass transition in parameter regions where the laminar profile is stable. We here add a temperature gradient perpendicular to the plate and explore the interaction between convection and shear in determining the transition. We find that the laminar state becomes unstable in a subcritical bifurcation and that the critical Rayleigh number and wave number depend strongly on the Prandtl number. We also track several secondary bifurcations and identify states that are localized in two directions, showing different symmetries. In the subcritical regime, transient turbulent states which are connected to exact coherent states and follow the same transition scenario as found in linearly stable shear flows are identified and analyzed. The study extends the bypass transition scenario from shear flows to thermal boundary layers and shows the intricate interactions between thermal and shear forces in determining critical po...

  18. Bi-stability of micro-plates: A sensitive mechanism for differential pressure measurements

    Science.gov (United States)

    Sajadi, Banafsheh; Goosen, Johannes Hans; van Keulen, Fred

    2017-09-01

    The electrostatic instability (pull-in) of a flat electrode in a parallel plate capacitor has been shown to be highly sensitive to external mechanical loads such as pressure. In this paper, we substantiate the possibility of prompting additional unstable configurations in such a system, with a remarkable sensitivity to the applied pressure. This additional instability has significant advantageous properties for sensing purposes. In addition to the high sensitivity and robustness of the pull-in voltage measurements, it can be adjusted so that after the unstable configuration is met, a snap-through to a new stable configuration occurs. As a result of this bi-stable behavior, the contact between the electrodes, which is the main drawback of pull-in phenomena, will be easily avoided. The results of this paper particularly suggest the suitability of this mechanism for two different methods of pressure measurements.

  19. Well-posedness and exponential stability for a plate equation with time-varying delay and past history

    Science.gov (United States)

    Feng, Baowei

    2017-02-01

    This paper is concerned with a class of plate equation with past history and time-varying delay in the internal feedback u_{tt}+α Δ ^2 u-int limits ^t_{-∞}g(t-s)Δ ^2 u(s)ds+μ _1u_t+μ _2u_t(t-τ (t))+f(u)=h(x), defined in a bounded domain of {R}^n (n≥1) with some suitable initial data and boundary conditions. For arbitrary real numbers μ _1 and μ _2, we proved the global well-posedness of the problem. Results on stability of energy are also proved under some restrictions on μ _1, μ _2 and h(x)=0.

  20. Special plate stability problems encountered in designing steel frameworks supporting large machinery operated in opencast mines

    Energy Technology Data Exchange (ETDEWEB)

    Ambrozy, G.

    1986-01-01

    The construction of large machinery that operates in opencast mines should by preceded by stability calculations as accurately as possible. The mathematical solution of the task is described. The method involves the determination of the coefficient matrix and of the coordinate functions. The accuracy of the results is estimated. Nomograms of the results obtained by using a computer program are presented. A numeric example verifies the validity of the mathematical solution.

  1. Investment, Macroeconomic Stability and Growth: The Latin American Experience Investment, Macroeconomic Stability and Growth: The Latin American Experience

    Directory of Open Access Journals (Sweden)

    Patricio Rojas

    1993-03-01

    Full Text Available The purpose of this paper is to explore the role of factor accumulation, economic policies, and economic and political uncertainties on growth performance of Latin American countries in the last three decades. We extend the work of Corbo and Rojas (1992 in two directions suggested by recent work in this area. First, we extend the model by considering term of trade effects and an additional measure of distortion, the black marker premium. Second, we provide further evidence of the channels through which economic policies affect growth by endogenizing the investment rate. The main conclusions are that the terms of trade affect growth directly, and indirectly through its effect in the investment rate: the black market premium is more a measure of macroeconomic instability than of the degree of oppenness; and stability of economic policies can affect growth directly through the law of motion for growth and indirectly through investment rates. Investment, Macroeconomic Stability and Growth: The Latin American Experience

  2. Vortex shedding experiment with flat and curved bluff plates in water

    Science.gov (United States)

    Reed, D.; Nesman, T.; Howard, P.

    1988-01-01

    Vortex shedding experiments were conducted in a water flow facility in order to simulate the strong discrete 4000-Hz vibration detected in the Space Shuttle Main Engine (SSME) which is thought to be associated with the SSME LOX inlet tee splitter vanes on the Main Injector. For the case of a flat vane with a blunt trailing edge excited by flow induced vortex shedding, lock-in with the first bending mode of the plate was observed. A curved vane displayed similar behavior, with the lock-in being a more discrete higher amplitude response. Aluminum vanes were employed to decouple the first vane bending mode from the vortex shedding mode. The application of an asymmetric 30-deg trailing edge bevel to both the flat and curved vanes was found to greatly reduce the strength of the shed vortices.

  3. Performance of Resistive Plate Chambers installed during the first long shutdown of the CMS experiment

    CERN Document Server

    Shopova, M; Hadjiiska, R; Iaydjiev, P; Sultanov, G; Rodozov, M; Stoykova, S; Assran, Y; Sayed, A; Radi, A; Aly, S; Singh, G; Abbrescia, M; Iaselli, G; Maggi, M; Pugliese, G; Verwilligen, P; Van Doninck, W; Colafranceschi, S; Sharma, A; Benussi, L; Bianco, S; Piccolo, D; Primavera, F; Cimmino, A; Crucy, S; Rios, A A O; Tytgat, M; Zaganidis, N; Gul, M; Fagot, A; Bhatnagar, V; Singh, J; Kumari, R; Mehta, A; Ahmad, A; Awan, I M; Shahzad, H; Hoorani, H; Asghar, M I; Muhammad, S; Ahmed, W; Shah, M A; Cho, S W; Choi, S Y; Hong, B; Kang, M H; Lee, K S; Lim, J H; Park, S K; Kim, M S; Laktineh, I B; Lagarde, F; Gouzevitch, M; Grenier, G; Pedraza, I; Bernardino, S Carpinteyro; Estrada, C Uribe; Moreno, S Carrillo; Valencia, F Vazquez; Pant, L M; Buontempo, S; Cavallo, N; Fabozzi, F; Orso, I; Lista, L; Meola, S; Merola, M; Paolucci, P; Thyssen, F; Lanza, G; Esposito, M; Braghieri, A; Magnani, A; Riccardi, C; Salvini, P; Vai, I; Vitulo, P; Montagna, P; Ban, Y; Qian, S J; Choi, M; Choi, Y; Goh, J; Kim, D; Dimitrov, A; Litov, L; Petkov, P; Pavlov, B; Bagaturia, I; Lomidze, D; Avila, C; Cabrera, A; Sanabria, J C; Crotty, I; Vaitkus, J

    2016-01-01

    The CMS experiment, located at the CERN Large Hadron Collider, has a redundant muon system composed by three different detector technologies: Cathode Strip Chambers (in the forward regions), Drift Tubes (in the central region) and Resistive Plate Chambers (both its central and forward regions). All three are used for muon reconstruction and triggering. During the first long shutdown (LS1) of the LHC (2013-2014) the CMS muon system has been upgraded with 144 newly installed RPCs on the forth forward stations. The new chambers ensure and enhance the muon trigger efficiency in the high luminosity conditions of the LHC Run2. The chambers have been successfully installed and commissioned. The system has been run successfully and experimental data has been collected and analyzed. The performance results of the newly installed RPCs will be presented.

  4. Lithosphere continental rifting and necking in 3D analogue experiments: role of plate divergence rate.

    Science.gov (United States)

    Nestola, Y.; Storti, F.; Cavozzi, C.

    2014-12-01

    The evolution of lithosphere necking is a fundamental parameter controlling the structural architecture and thermal state of rifted margins. Despite a large number of analogue and numerical modelling studies on lithosphere extension are available in the literature, a quantitative experimental description of lithosphere necking evolution is still lacking. Extensional strain rate and thermal layering of the lithosphere exert a fundamental control on necking shape and evolution. We focused our experimental work on the former parameter and simulated the progression of lithosphere thinning and necking during asymmetric orthogonal rifting at different plate divergence rates. Our models involve a 4-layer mechanical continental lithosphere, which rests on a glucose syrup asthenosphere. Both the topography and the base of the lithosphere were monitored by time-lapse laser scanning. This technical approach allowed us to quantify the evolution in space and time of the thinning factors for the crust, mantle, and lithosphere as a whole. Laser-scanning monitoring provided also a detailed picture of the evolving neck shape, which shows a strong dependency on the strain-rate. At low strain-rates, necking is "boxed" with steep flanks and a flat-lying roof, and few deep basins develop at surface. At high strain-rates, more distributed thinning occurs and isolates portions of less deformed mantle. More distributed deformation affects the model topography. Despite large differences in shape, the aspect ratio (amplitude/wavelength) of the cross-sectional neck shapes converges towards very similar values at the end of the experiments.The significant differences and evolutionary pathways produced by the plate divergence rate on the lithosphere necking profile, suggest that this parameter exert a fundamental control on localization vs. distribution of deformation in the crust as in the whole mechanical lithosphere. Furthermore, it can exert a fundamental control on the time and space

  5. Stability and Variability in Aesthetic Experience: A Review

    Science.gov (United States)

    Jacobsen, Thomas; Beudt, Susan

    2017-01-01

    Based on psychophysics’ pragmatic dualism, we trace the cognitive neuroscience of stability and variability in aesthetic experience. With regard to different domains of aesthetic processing, we touch upon the relevance of cognitive schemata for aesthetic preference. Attitudes and preferences are explored in detail. Evolutionary constraints on attitude formation or schema generation are elucidated, just as the often seemingly arbitrary influences of social, societal, and cultural nature are. A particular focus is put on the concept of critical periods during an individual’s ontogenesis. The latter contrasting with changes of high frequency, such as fashion influences. Taken together, these analyses document the state of the art in the field and, potentially, highlight avenues for future research. PMID:28223955

  6. Biomechanical Analysis Of The Proximal Femoral Locking Compression Plate: Do Quality Of Reduction And Screw Orientation Influence Construct Stability?

    Science.gov (United States)

    Zderic, Ivan; Oh, Jong-Keon; Stoffel, Karl; Sommer, Christoph; Helfen, Tobias; Camino, Gaston; Richards, R Geoff; Nork, Sean E; Gueorguiev, Boyko

    2017-08-22

    To investigate biomechanically in a human cadaveric model the failure modes of the Proximal Femoral Locking Compression Plate (PF-LCP) and explore the underlying mechanism. Twenty-four fresh-frozen paired human cadaveric femora with simulated unstable intertrochanteric fractures (AO/OTA 31-A3.3) were assigned to four groups with six specimens each for plating with PF-LCP. The groups differed in the quality of fracture reduction and plating fashion of the first and second proximal screws as follows: 1) anatomical reduction with on-axis screw placement; 2) anatomical reduction with off-axis screw placement; 3) malreduction with on-axis screw placement; 4) malreduction with off-axis screw placement. The specimens were tested until failure using a protocol with combined axial and torsional loading. Mechanical failure was defined as abrupt change in machine load-displacement data. Clinical failure was defined as 5° varus tilting of the femoral head as captured with optical motion tracking. Initial axial stiffness (N/mm) in groups 1 to 4 was 213.6±65.0, 209.5±134.0, 128.3±16.6 and 106.3±47.4, respectively. Numbers of cycles to clinical and mechanical failure were 16642±10468 and 8695±1462 in group 1, 14076±3032 and 7449±5663 in group 2, 8800±8584 and 4497±2336 in group 3 and 9709±3894 and 5279±4119 in group 4. Significantly higher stiffness as well as numbers of cycles to both clinical and mechanical failure were detected in group 1 in comparison to group 3, P≤0.044. Generally, malreduction led to significantly earlier construct failure. The observed failures were cut-out of the proximal screws in the femoral head, followed by either screw bending, screw loosening or screw fracture. Proper placement of the proximal screws in anatomically reduced fractures led to significantly higher construct stability. Our data also indicates that once the screws are placed off-axis (>5 degrees), the benefit of an anatomic reduction is lost.

  7. Crane scheduling for a plate storage in a shipyard: Experiments and results

    DEFF Research Database (Denmark)

    Hansen, Jesper; Kristensen, Torben F.H.

    2003-01-01

    This document is the third in a series of three describing an investigation of possible improvements in methods for handling the storage of steel plates at Odense Steel Shipyard (OSS). Steel ships are constructed by cutting up plates and afterwards welding them together to produce blocks. These b......This document is the third in a series of three describing an investigation of possible improvements in methods for handling the storage of steel plates at Odense Steel Shipyard (OSS). Steel ships are constructed by cutting up plates and afterwards welding them together to produce blocks...

  8. STRUCTURE, MECHANICAL PROPERTIES AND THERMAL STABILITY OF DIAMOND-LIKE CARBON FILMS PREPARED BY ARC ION PLATING

    Institute of Scientific and Technical Information of China (English)

    Y.S. Zou; J.D. Zheng; J. Gong; C. Sun; R.F. Huang; L.S. Wen

    2005-01-01

    Diamond-like Carbon (DLC) films have been prepared on Si(100) substrates by arc ion plating in conjunction with pulse bias voltage under H2 atmosphere. The deposited films have been characterized by scanning electron microscopy and atomic force microscopy. The results show that the surface of the film is smooth and dense without any cracks, and the surface roughness is low. The bonding characteristic of the films has been studied by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. It shows the sp3 bond content of the film deposited at -200V is 26.7%. The hardness and elastic modulus of the film determined by nanoindentation technique are 30.8 and 250.1GPa, respectively. The tribological characteristic of the films reveals that they have low friction coefficient and good wear-resistance. After deposition, the films have been annealed in the range of 350-700℃ for 1h in vacuum to investigate the thermal stability. Raman spectra indicate that the ID/IG ratio and G peak position have few detectable changes below 500℃. Further increasing the annealing temperature, the hydrogen can be released, the structure rearranges, and the phase transition of sp3 configured carbon to sp2 configured carbon appears.

  9. Sharp three sphere inequality for perturbations of a product of two second order elliptic operators and stability for the Cauchy problem for the anisotropic plate equation

    CERN Document Server

    Morassi, Antonino; Vessella, Sergio

    2010-01-01

    We prove a sharp three sphere inequality for solutions to third order perturbations of a product of two second order elliptic operators with real coefficients. Then we derive various kinds of quantitative estimates of unique continuation for the anisotropic plate equation. Among these, we prove a stability estimate for the Cauchy problem for such an equation and we illustrate some applications to the size estimates of an unknown inclusion made of different material that might be present in the plate. The paper is self-contained and the Carleman estimate, from which the sharp three sphere inequality is derived, is proved in an elementary and direct way based on standard integration by parts.

  10. Studies of purification of the Resistive Plate Chamber gas mixture for the Large Hadron Collider experiments

    CERN Document Server

    Capeans, M; Guida, R; Hahn, F; Haider, S

    2009-01-01

    The Resistive Plate Chambers (RPCs) installed as part of the large muon detectors at the Large Hadron Collider (LHC) experiments use a gas mixture of 94.7% C2H2F4, 5% iC(4)H(10) and 0.3% SF6. Based on economical grounds, the design philosophy of the gas systems for the ATLAS and CMS RPC's foresees to recirculate the gas mixture in 90-95% closed loop circulation. At the LHC, RPC chambers are operated in a high radiation environment, conditions for which large amount of impurities in the return gas have been observed in earlier studies. They are potentially dangerous for the stable operation of the detectors, the materials in the detector and the gas system. While several purification stages have been foreseen in the present gas systems, chemical reactions between the absorber and the impurities are yet not well understood. Furthermore, the effects on the gas mixture of the foreseen factor 10 increase of luminosity for the LHC upgraded phase should be studied. We present the results of systematic studies of the...

  11. High-resolution neutron radiography with microchannel plates: Proof-of-principle experiments at PSI

    Science.gov (United States)

    Tremsin, A. S.; McPhate, J. B.; Vallerga, J. V.; Siegmund, O. H. W.; Hull, J. S.; Feller, W. B.; Lehmann, E.

    2009-06-01

    With the appearance of highly collimated and intense neutron beamlines, the resolution of radiographic experiments is often limited by the parameters of the neutron imaging detector. Neutron-sensitive microchannel plates (MCPs) proved to be very efficient for conversion of a thermal or cold neutron into an electron pulse of up to 10 6 electrons preserving location of the neutron absorption within ˜15 μm. In this paper, we present the results of preliminary measurements performed with neutron-sensitive MCPs coupled with a Medipix2/Timepix active pixel sensor. A set of test objects was imaged at both thermal and cold neutron imaging beamlines of Paul Scherrer Institute. The spatial resolution of the detector operating at high counting rate mode was confirmed to be limited by the 55 μm pixel size of the Medipix2 readout. At the same time, event centroiding applied to the charge values measured with Timepix readout allowed individual neutron counting with spatial resolution on the scale of MCP pore spacing (11 μm in the present measurements). The ongoing improvement of the speed of the readout electronics should eliminate the low counting rate limitation of the latter high-resolution imaging.

  12. Plate impact experiments on DC745U cooled to ~ -60 °C

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsen, Richard L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Dattelbaum, Dana M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Bartram, Brian Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Gibson, Lloyd Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Jones, Justin Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Goodbody, Austin Bernard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics

    2016-08-11

    Using gas-gun driven plate impact experiments, we have measured the US - up Hugoniot of the silicone elastomer DC745U cooled to -60 °C. In summary, the initial density changes from p0 (23°C) = 1.312 ± 0.010 g/cm3 to p0 (-60°C) = 1.447 ± 0.011 g/cm3. The linear US - up Hugoniot changes from US = 1.62 + 1.74up km/s at +23°C, to US = 2.03 ± 0.06 + (2.03 ± 0.06) up km/s at -60°C. DC745U, therefore is much stiffer at -60°C than at +23°C, probably due to the crystallization that occurs at ~ -50°C. Caveats/deficiencies: 1) This report does not provide an adequate pedigree of the DC745U used. 2) References to unpublished room temperature shock compression data on the elastomer are inadequate. 3) The report has not been fact checked by a DC745 subject matter expert.

  13. Development of a fully differential multi-gap resistive plate chamber for the CBM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Deppner, Ingo Martin

    2013-11-21

    The subject of this thesis is the development of a modern time-of-flight detector, a MRPC (Multi-gap Resistive Plate Chamber) for the Compressed Baryonic Matter (CBM) experiment. The main goal of CBM is the investigation of the phase diagram of strongly interacting matter in the region of the highest baryon densities. In order to measure the necessary observables with unprecedented precision an excellent particle identification is required. The key element providing hadron identification in heavy ion reaction at incident energies between 2 and 35 AGeV is a 120 m{sup 2} large Time-of-Flight (ToF) wall composed of MRPCs. The ToF-wall is subdivided in a high rate, an intermediate rate and a low rate region. In this thesis we present a full-size demonstrator for the intermediate rate region and for the low rate region. In-beam and cosmic ray tests demonstrated that these fully differential prototypes fulfill the necessary requirements which are a counter time resolution of about 50 ps, an efficiency above 95 %, a rate capability of about 1 kHz/cm{sup 2} and a granularity between 25 - 50 cm{sup 2}. Based on these counters the so-called ''outer ToF-wall'' was designed in this work.

  14. Field experience and improvements with thin tubular-plate lead/acid technology

    Energy Technology Data Exchange (ETDEWEB)

    Merz, K.D. [CMP Batteries, Bolton (United Kingdom)

    1998-05-18

    The Classic 25 is the product name for a motive-power lead/acid cell using thin positive tubular plates. This cell was developed for use in electric vehicles and other applications where high specific energy and reliable cycle life is required. It would appear that the best approach is to provide a lead/acid battery that has the highest specific energy while still maintaining excellent cycle life. This technology was implemented by use of 6 V modules, followed by a 2-V design. Since this was first introduced in 1989, more than 20 000 cells and monoblocs have been delivered to various electric vehicle applications such as vans, trucks, and buses. The field experience with this product is therefore excellent, and development is continuing on the battery design and manufacturing techniques to improve performance and life even further. Today, a wide range of products using this technology is available, and the latest developments are a new 6 V monobloc and some maintenance-free cells. (orig.)

  15. The analog Resistive Plate Chamber detector of the ARGO-YBJ experiment

    CERN Document Server

    Bartoli, B; Bi, X J; Cao, Z; Catalanotti, S; Chen, S Z; Chen, T L; Cui, S W; Dai, B Z; D'Amone, A; Danzengluobu,; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Iacovacci, M; Iuppa, R; Jia, H Y; Labaciren,; Li, H J; Liu, C; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari1, S M; Marsella, G; Mastroianni, S; Montini, P; Ning, C C; Perrone, L; Pistilli, P; Salvini1, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, H; Wu, C Y; Wu, H R; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, L; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q

    2015-01-01

    The ARGO-YBJ experiment has been in stable data taking from November 2007 till February 2013 at the YangBaJing Cosmic Ray Observatory (4300 m a.s.l.). The detector consists of a single layer of Resistive Plate Chambers (RPCs) ( about 6700 m^2}) operated in streamer mode. The signal pick-up is obtained by means of strips facing one side of the gas volume. The digital readout of the signals, while allows a high space-time resolution in the shower front reconstruction, limits the measurable energy to a few hundred TeV. In order to fully investigate the 1-10 PeV region, an analog readout has been implemented by instrumenting each RPC with two large size electrodes facing the other side of the gas volume. Since December 2009 the RPC charge readout has been in operation on the entire central carpet (about 5800 m^2). In this configuration the detector is able to measure the particle density at the core position where it ranges from tens to many thousands of particles per m^2. Thus ARGO-YBJ provides a highly detailed...

  16. Novel pedicle screw and plate system provides superior stability in unilateral fixation for minimally invasive transforaminal lumbar interbody fusion: an in vitro biomechanical study.

    Directory of Open Access Journals (Sweden)

    Jie Li

    Full Text Available This study aims to compare the biomechanical properties of the novel pedicle screw and plate system with the traditional rod system in asymmetrical posterior stabilization for minimally invasive transforaminal lumbar interbody fusion (MI-TLIF. We compared the immediate stabilizing effects of fusion segment and the strain distribution on the vertebral body.Seven fresh calf lumbar spines (L3-L6 were tested. Flexion/extension, lateral bending, and axial rotation were induced by pure moments of ± 5.0 Nm and the range of motion (ROM was recorded. Strain gauges were instrumented at L4 and L5 vertebral body to record the strain distribution under flexion and lateral bending (LB. After intact kinematic analysis, a right sided TLIF was performed at L4-L5. Then each specimen was tested for the following constructs: unilateral pedicle screw and rod (UR; unilateral pedicle screw and plate (UP; UR and transfacet pedicle screw (TFS; UP and TFS; UP and UR.All instrumented constructs significantly reduced ROM in all motion compared with the intact specimen, except the UR construct in axial rotation. Unilateral fixation (UR or UP reduced ROM less compared with the bilateral fixation (UP/UR+TFS, UP+UR. The plate system resulted in more reduction in ROM compared with the rod system, especially in axial rotation. UP construct provided more stability in axial rotation compared with UR construct. The strain distribution on the left and right side of L4 vertebral body was significantly different from UR and UR+TFS construct under flexion motion. The strain distribution on L4 vertebral body was significantly influenced by different fixation constructs.The novel plate could provide sufficient segmental stability in axial rotation. The UR construct exhibits weak stability and asymmetrical strain distribution in fusion segment, while the UP construct is a good alternative choice for unilateral posterior fixation of MI-TLIF.

  17. Plate impact experiments on the TATB based explosive PBX 9502 at pressures near the Chapman-Jouguet state

    Science.gov (United States)

    Gustavsen, R. L.; Aslam, T. D.; Bartram, B. D.; Hollowell, B. C.

    2014-05-01

    A series of two-stage gus-gun driven plate impact experiments on PBX 9502 (95 wt.% tri-amino-trinitro-benzene, 5 wt.% Kel-F800 plastic binder) was completed in the 28-34 GPa pressure range. This is just above the Chapman-Jouguet state of ≈ 28 GPa. The experiments consisted of a thick oxygen free high conductivity copper (OFHC Cu) flyer plate impacting a PBX 9502 sample backed by a Lithium Fluoride (LiF) window. Photonic Doppler Velocimetry (PDV) was used to measure velocity histories (wave profiles) at the PBX 9502/LiF interface. Shock transit times and sample thicknesses were converted to shock velocities, Us. Particle velocities, up, were calculated by way of impedance matching. Lastly, the measured wave profiles were compared with numerical simulations of the experiments using the Wescott-Stewart-Davis reactive-burn model.

  18. Active control of sound transmission/radiation from elastic plates by vibration inputs. II - Experiments

    Science.gov (United States)

    Metcalf, V. L.; Fuller, C. R.; Silcox, R. J.; Brown, D. E.

    1992-01-01

    Actively controlled harmonic force inputs were applied experimentally to reduce the sound transmitted through an elastic circular plate. The control implementation used a time domain least mean square adaptive algorithm with two error sensors. The control forces were applied directly to the plate by point force vibration inputs, while the error information and performance were measured in the radiated acoustic field by microphones. Test cases were also performed in which the error sensors were accelerometers mounted on the plate. When accelerometers were used as error sensors, the controller performance was degraded; leading to the conclusion that minimizing plate motion does not necessarily lead to an associated decrease in radiated sound levels. In contrast, the results show excellent attenuation of the transmitted sound field when microphone error sensors were used. This result was consistent over a range of frequencies. In addition, the experimental results are compared to previously derived analytical results and the effect of using a point or global minimization scheme is discussed.

  19. Stability of plate structures

    DEFF Research Database (Denmark)

    Hansen, Klaus; Hansen, Klavs Feilberg

    Danish concrete panel building systems have aroused considerable interest in many other countries. The present book, which is a translation of an SBI Direction, deals with various methods applied by Danish engineers in the design of shear wall buildings. In addition information is given on the ca...

  20. Analytical and numerical stability analysis of Soret-driven convection in a horizontal porous layer: the effect of conducting bounding plates

    Energy Technology Data Exchange (ETDEWEB)

    Ouattara, B; Khouzam, A; Mojtabi, A [Universite de Toulouse (France); INPT, UPS (France); IMFT (Institut de Mecanique des Fluides de Toulouse), Allee Camille Soula, F-31400 Toulouse (France); Charrier-Mojtabi, M C, E-mail: bouattar@imft.fr, E-mail: akhouzam@imft.fr, E-mail: mojtabi@imft.fr, E-mail: cmojtabi@cict.fr [PHASE, EA 810, UFR PCA, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse cedex (France)

    2012-06-01

    The aim of this study was to investigate the effect of conducting boundaries on the onset of convection in a binary fluid-saturated porous layer. The isotropic saturated porous layer is bounded by two impermeable but thermally conducting plates, subjected to a constant heat flux. These plates have identical conductivity. Moreover, the conductivity of the plates is generally different from the porous layer conductivity. The overall layer is of large extent in both horizontal directions. The problem is governed by seven dimensionless parameters, namely the normalized porosity of the medium {epsilon}, the ratio of plates over the porous layer thickness {delta} and their relative thermal conductivities ratio d, the separation ratio {delta}, the Lewis number Le and thermal Rayleigh number Ra. In this work, an analytical and numerical stability analysis is performed. The equilibrium solution is found to lose its stability via a stationary bifurcation or a Hopf bifurcation depending on the values of the dimensionless parameters. For the long-wavelength mode, the critical Rayleigh number is obtained as Ra{sub cs}=12(1+2d{delta} )/[1+{psi} (2d{delta}Le+Le+1)] and k{sub cs}=0 for {psi}> {psi} {sub uni}> 0. This work extends an earlier paper by Mojtabi and Rees (2011 Int. J. Heat Mass Transfer 54 293-301) who considered a configuration where the porous layer is saturated by a pure fluid.

  1. Mean flow stability analysis of oscillating jet experiments

    CERN Document Server

    Oberleithner, Kilian; Soria, Julio

    2014-01-01

    Linear stability analysis is applied to the mean flow of an oscillating round jet with the aim to investigate the robustness and accuracy of mean flow stability wave models. The jet's axisymmetric mode is excited at the nozzle lip through a sinusoidal modulation of the flow rate at amplitudes ranging from 0.1 % to 100 %. The instantaneous flow field is measured via particle image velocimetry and decomposed into a mean and periodic part utilizing proper orthogonal decomposition. Local linear stability analysis is applied to the measured mean flow adopting a weakly nonparallel flow approach. The resulting global perturbation field is carefully compared to the measurements in terms of spatial growth rate, phase velocity, and phase and amplitude distribution. It is shown that the stability wave model accurately predicts the excited flow oscillations during their entire growth phase and during a large part of their decay phase. The stability wave model applies over a wide range of forcing amplitudes, showing no pr...

  2. ON THE STABILITY ANALYSIS OF PLATES AND SHELLS USING A QUADRILATERAL,16-DEGREES OF FREEDOM PLAT SHELL ELEMENT DKQ16

    Institute of Scientific and Technical Information of China (English)

    郑长良; 李丽华; 钟万勰

    2004-01-01

    The linear buckling problems of plates and shells were analysed using a recently developped quadrilateral, 16-degrees of freedom flat shell element (called DKQ16). The geometrical stiffness matrix was established. Comparison of the numerical results for several typical problems shows that the DKQ16 element has a very good precision for the linear buckling problems of plates and shells.

  3. Experience of the Indirect Neutron Radiography Method Based on the X-ray Imaging Plate at CARR

    Science.gov (United States)

    Wei, Guohai; Han, Songbai; Wang, Hongli; He, Linfeng; Wang, Yu; Wu, Meimei; Liu, Yuntao; Chen, Dongfeng

    Indirect neutron radiography (INR) experiments by X-ray imaging plate were carried out at the China Advanced Research Reactor (CARR). The key experiment parameters were optimized, especially the exposure time of the neutron converter andimaging plate. The optimized total exposure time is 37.25 min, it is two-fifths of the timebased on the film method under the same experimental conditions. The qualitative and quantitativeinspections were tested with dummy nuclear fuel rods and a water temperaturesensor ofa motor vehicle. The spring in the sensor and the defects of the dummy fuel rod's pellets can be qualitatively detected. The thickness of the tape at one position on the cladding of the dummy nuclear fuel rodwas quantitatively calculated to be 9.57 layers with the relative error of ±4.3%.

  4. Research on Stability Reinforcement of Composite Laminated Plates with Cutouts%开口复合材料层合板稳定性补强研究

    Institute of Scientific and Technical Information of China (English)

    何帅; 万小朋; 赵美英

    2012-01-01

    It is generally accepted that composite laminated plates with cutouts not only reduce the strength of struc tures but also have a serious effect on stability. Linear eigenvalue method is used to study stability of laminated plates under uniaxial compression. Flange reinforcement, single ring reinforcement, double ring reinforcement and center tube reinforcement are adopted to reinforce the stability of plates with cutouts. In the case of reinforcement structures having the same additional mass, better plans are got by comparing critical buckling loads. The best de sign range of reinforcement parameters such as flange on stability. These conclusions will provide references angle, flange height are obtained by studying their influence for stability reinforcement of cutouts structures.%开口复合材料层合板不但降低结构强度,而且对稳定性有严重影响。用线性特征值法研究不同开口尺寸下层合板轴压稳定性,并采用翻边补强、单边贴片补强、双边贴片补强和中心圆环补强等几种方案来提高开口层合板稳定性。在补强结构增加质量相同的情况下比较各种方案的失稳,临界载荷,得出稳定性补强较好的方案。通过研究下陷角度、下陷深度、补强片厚度等参数对稳定性的影响,得到补强参数较好的设计范围。

  5. Flyer-Plate-Based Current Diagnostic for Magnetized Liner Inertial Fusion Experiments

    Science.gov (United States)

    Reneker, Joseph; Gomez, Matthew; Hess, Mark; Jennings, Christopher

    2015-11-01

    Accurate measurements of the current delivered to Magnetized Liner Inertial Fusion (MagLIF) loads on the Z machine are important for understanding the dynamics of liner implosions. Difficulty acquiring a reliable load current measurement with the standard Z load B-dots has spurred the development of alternative load current diagnostics. Velocimetry of an electromagnetically-accelerated flyer plate can be used to infer the drive current on a flyer surface. A load current diagnostic design is proposed using a cylindrical flyer plate in series with the MagLIF target. Aspects of the flyer plate design were optimized using magnetohydrodynamic simulations. Design and preliminary results will be presented. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  6. NUMERICAL ANALYSIS AND EXPERIMENT OF UNSTEADY THERMAL FIELDOF ROTOR PLATE FOR EDDY CURRENT RETARDER

    Institute of Scientific and Technical Information of China (English)

    LIU Chengye; HE Ren

    2008-01-01

    The physical model based on heat transfer theory and virtual boundary method for analyzing unsteady thermal field of rotor plate for eddy current retarder used in automobile is established and boundary conditions are also defined. The finite element governing equation is derived by Galerkin method. The time differential item is discrete based on Galerkin format that is stable at any condition. And a new style of varying time step method is used in iteration process. The thermal field on the rotor plate at the radial and axle directions is analyzed and varying temperature at appointed points on two side-surfaces is measured. The testing and analytical data are uniform approximately. Finite element method can be used for estimating thermal field of the rotor plate at initial design stage of eddy current retarder.

  7. 3-D thermo-mechanical laboratory modeling of plate-tectonics: modeling scheme, technique and first experiments

    Directory of Open Access Journals (Sweden)

    D. Boutelier

    2011-05-01

    Full Text Available We present an experimental apparatus for 3-D thermo-mechanical analogue modeling of plate tectonic processes such as oceanic and continental subductions, arc-continent or continental collisions. The model lithosphere, made of temperature-sensitive elasto-plastic analogue materials with strain softening, is submitted to a constant temperature gradient causing a strength reduction with depth in each layer. The surface temperature is imposed using infrared emitters, which allows maintaining an unobstructed view of the model surface and the use of a high resolution optical strain monitoring technique (Particle Imaging Velocimetry. Subduction experiments illustrate how the stress conditions on the interplate zone can be estimated using a force sensor attached to the back of the upper plate and adjusted via the density and strength of the subducting lithosphere or the lubrication of the plate boundary. The first experimental results reveal the potential of the experimental set-up to investigate the three-dimensional solid-mechanics interactions of lithospheric plates in multiple natural situations.

  8. Beam test results on double-gap resistive plate chambers proposed for CMS experiment

    Science.gov (United States)

    Abbrescia, M.; Bruno, G.; Colaleo, A.; Iaselli, G.; Lamanna, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Gianini, G.; Ratti, S. P.; Vitulo, P.

    Resistive Plate Chambers were tested in a muon and pion beam to study the performances at different running conditions. Results on a first chamber built without the linseed oil treatment of the bakelite surfaces are presented together with an evaluation of the local effects due to the spacers. These results are extrapolated to the conditions expected at LHC.

  9. Beam Test Results on Resistive Plate Chambers for the CMS Experiment

    CERN Document Server

    Abbrescia, Marcello; Calaeo, A; Iaselli, Giuseppe; Lammana, G; Loddo, Flavio; Maggi, Marcello; Marangelli, Bartolomeo; Natali, Sergio; Nuzzo, Salvatore; Puglise, G; Ranieri, Riccardo; Ratti, Sergio P; Romano, Francesco; Vitulo, Paolo

    1998-01-01

    Resistive Plate Chambers were tested in a muon and a pion beam to study the performances at different running conditions. Results on a first chamber built without the linseed oil treatment of the bakelite surfaces are presented together with an evaluation of the local effects dut to spacers. These results are extrapolated to the conditions expected at LHC.

  10. Experiences With The Reactive Low Voltage Ion Plating In Optical Thin Film Production

    Science.gov (United States)

    Guertler, Karlheinz; Jeschkowski, Ulrich; Conrath, E.

    1989-02-01

    The transmission of interference filters consisting of Ta205, Ti02, Zr02 and Si02 layers were measured at temperatures between 25°C and 185°C. Some characteristic differences between filters produced by reactive evaporation and reactive ion plating are demonstrated and discussed.

  11. The results and analysis of irradiation experiments conducted on reactor vessel plate and weld materials

    Energy Technology Data Exchange (ETDEWEB)

    Biemiller, E.C. [Yankee Atomic Electric Co., Bolton, MA (United States); Carter, R.G.; Rosinski, S.T. [Electric Power Research Inst., Charlotte, NC (United States)

    1996-09-01

    This paper documents the extensive amount of experimental work on radiation damage to reactor vessel materials carried out by Yankee Atomic Electric Company (YAEC) and others in support of a licensing effort to restart the Yankee Rowe nuclear power plant. The effect of plate nickel content and microstructure on irradiation damage sensitivity was assessed. Typical reactor pressure vessel plate materials each containing 0.24% (by weight) copper, but different nickel contents at 0.19% and 0.63% were heat treated to produce different microstructures. A Linde 80 weld containing 0.30% copper and 1.00% nickel was produced and heat treated to test microstructure effects on the irradiation response of weld metal. Materials taken from plate surface locations (vs 1/4%) were included to test whether or not the improved toughness properties of the plate surface layer, resulting from a rapid quench, is maintained after irradiation. Irradiations were conducted at two irradiation temperatures, 500 F (260 C) and 550 F (288 C), to determine the effect of irradiation temperature on embrittlement. The results of this irradiation testing and additional data from a DOE/Sandia National Laboratories irradiation study show an irradiation temperature effect that is not consistent, but varies with the materials tested. The test results demonstrate that for nickel bearing steels, the superior toughness of plate surface material is maintained even after irradiation to high fluences, and for the copper content tested, nickel has little effect on irradiation response. A mixed effect of microstructure/heat treatment on the materials` irradiation response was noted. Phosphorus potentially played a role in the irradiation response of the low nickel material irradiated at 500 F (288 C) but did not show prominence in the irradiations for the same material conducted at 500 F (260 C).

  12. Hydrodynamics of the interceptor on a 2-D flat plate by CFD and experiments

    Institute of Scientific and Technical Information of China (English)

    MANSOORI M; FERNANDES A C

    2015-01-01

    Nowadays, the use of interceptor by both partial and total dynamic lift crafts is quite common. In this article, a lot of evidence is given regarding the effectiveness of interceptor. The interceptor, when placed at the stern region, changes the pressure distribution around the craft. Its presence affects drag force, lifting force and the position of pressure’s center leading to a new trim. This study focuses on hydrodynamic effects of interceptors on a 2-D flat plate based on both computational fluid dynamic (CFD) and experimental approaches. The Reynolds average Navier-Stokes (RANS) equations are used to model the flow around a fixed flat plate with an interceptor at different heights and attack angles. Based on finite volume method and SIMPLE algorithm which uses static structures, this model can be analyzed and the RANS results can be compared with the experimental data obtained in the current channel of the laboratory of waves and current of COPPE/UFRJ (LOC in Portuguese acronym). According to the results, the increase of pressure at the end of the flat plate was proportional to the interceptor height. In addition, the existence of interceptors can significantly increase the lift force coefficient at high angles of attack also proportional to the interceptor height. The presence of interceptor at the end of the flat plate increased both the lift coefficient and the drag coefficient but hydrodynamic drag did not grow as fast as the lift coefficient did. The lift coefficient increased much more. Furthermore, the results showed that the interceptor effectiveness is proportional to the boundary layer thickness at the end of the flat plate. As the interceptor was inside the boundary layer alterations of flow speed led to changes in boundary layer thickness, directly affecting interceptor’s efficiency. Optimum choice of interceptor height had a great effect on its efficiency, and in choosing it the flow speed and length of the boat must be taken into

  13. The compact capacitor bank CQ-1.5 employed in magnetically driven isentropic compression and high velocity flyer plate experiments.

    Science.gov (United States)

    Wang, Guiji; Sun, Chengwei; Tan, Fuli; Zhao, Jianheng; Zhang, Ning; Liu, Cangli; Mo, Jianjun; Wang, Ganghua; Wang, Xiaosong

    2008-05-01

    Based on the low inductance capacitor, the parallel-plate transmission line, and the explosive network closing switch, a compact pulsed power generator CQ-1.5 has been developed at the Institute of Fluid Physics and is capable to deliver a current of peak of 1.5 MA within rise time of 500-570 ns into a 2-3 nH inductive load. The work is motivated to do isentropic compression experiments (ICEs) on metals up to 30-50 GPa and to launch flyer plates at velocities over 8 kms. The experiments were conducted with the diagnostics of both Doppler pin system and velocity interferometer system for any reflectors, and the measured free surface velocity histories of ICE samples were treated with a backward integration code. The results show that the isentropes of Cu and Al samples under 35 GPa are close to their Hugoniots within a deviation of 3%. The LY12 aluminum flyer plates were accelerated to a velocity over 8.96 kms.

  14. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will; Young, R. Paul [Applied Seismology Consultants Ltd., Shrewsbury (United Kingdom)

    2005-12-15

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set

  15. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will; Young, R. Paul [Applied Seismology Consultants Ltd., Shrewsbury (United Kingdom)

    2005-12-15

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set

  16. High resolution, two-dimensional imaging, microchannel plate detector for use on a sounding rocket experiment

    Science.gov (United States)

    Bush, Brett C.; Cotton, Daniel M.; Siegmund, Oswald H.; Chakrabarti, Supriya; Harris, Walter; Clarke, John

    1991-01-01

    We discuss a high resolution microchannel plate (MCP) imaging detector to be used in measurements of Doppler-shifted hydrogen Lyman-alpha line emission from Jupiter and the interplanetary medium. The detector is housed in a vacuum-tight stainless steel cylinder (to provide shielding from magnetic fields) with a MgF2 window. Operating at nominal voltage, the four plate configuration provides a gain of 1.2 x 10 exp 7 electrons per incident photon. The wedge-and-strip anode has two-dimensional imaging capabilities, with a resolution of 40 microns FWHM over a one centimeter diameter area. The detector has a high quantum efficiency while retaining a low background rate. A KBr photocathode is used to enhance the quantum efficiency of the bare MCPs to a value of 35 percent at Lyman-alpha.

  17. Frictional sliding in layered rock: Preliminary experiments on stacked Lexan plates

    Energy Technology Data Exchange (ETDEWEB)

    Perry, K.E. Jr.; Epstein, J.S. [Idaho National Engineering Laboratory, Idaho Falls, ID (United States). Fracture Behavior Group; Jung, J. [Sandia National Labs., Albuquerque, NM (United States)

    1995-12-31

    Understanding the mechanical behavior of jointed-rock masses is of critical importance to designing and predicting the performance of a potential nuclear waste repositiry. To this end we have studied the frictional sliding between simulated rock joints using phase shifting moire interferometry. Preliminary calibration models were made from stacks of Lexan plates that were sand-blasted to provide a uniform frictional interface. Load was applied monotonically and phase shifted moire fringe patterns were recorded at three different load states. Plots of slip along the interfaces for the model are presented to demonstrate the ability of the photomechanics technique to provide precise measurements of in-plane displacement, and ultimately the slip between the plates.

  18. Vibrations of Poroelastic Plates: Mixed Displacement-Pressure Modelisation and Experiments

    OpenAIRE

    2009-01-01

    International audience; This paper presents the equations of motion of air saturated rectangular poroelastic plates. The model is based on a mixed displacement-pressure formulation of Biot's theory. Two equations of motion are obtained and solved with the Galerkin method for any boundary conditions. These equations take into account the solid-fluid coupling effects. Simulations of the bending vibrations of a rectangular water saturated sandstone and air saturated acoustic foam are performed f...

  19. Densitometric HPTLC method for qualitative, quantitative analysis and stability study of Coenzyme Q10 in pharmaceutical formulations utilizing normal and reversed-phase silica gel plates.

    Science.gov (United States)

    Abdel-Kader, Maged Saad; Alam, Prawez; Alqasoumi, Saleh Ibrahim

    2016-03-01

    Two simple, precise and stability-indicating densitometric HPTLC method were developed and validated for qualitative and quantitative analysis of Coenzyme Q10 in pharmaceutical formulations using normal-phase (Method I) and reversed phase (Method II) silica gel TLC plates. Both methods were developed and validated with 10×20 cm glass-backed plates coated with 0.2 mm layers of either silica gel 60 F254 (E-Merck, Germany) using hexane-ethyl acetate (8.5:1.5 v/v) as developing system (Method I) or RP-18 silica gel 60 F254 (E-Merck, Germany) using methanol-acetone (4:6 v/v) as mobile phase (Method II). Both analyses were scanned with a densitometer at 282 nm. Linearity was found in the ranges 50-800 ng/spot (r(2)=0.9989) and 50-800 ng/spot (r(2)=0.9987) for Method I and Method II respectively. Stability of Coenzyme Q10 was explored by the two methods using acid, base, hydrogen peroxide, temperature and different solvents. Due to the efficiency of the method in separating Coenzyme Q10 from other ingredients including its degradation products, it can be applied for quality control, standardization of different pharmaceutical formulations and stability study.

  20. Control and Stabilization: Making Millikan's Oil Drop Experiment Work

    Science.gov (United States)

    Muller-Hill, Christoph; Heering, Peter

    2011-01-01

    Educational versions of Millikan's oil-drop experiment have frequently been criticized; suggestions for improvement either focus on technical innovations of the setup or on replacing the experiment by other approaches of familiarization, such as computer simulations. In our approach, we have analysed experimental procedures. In doing so, we were…

  1. 考虑剪切效应有限变形粘弹性板的动力稳定性%Dynamic Stability of Viscoelastic Plates with Finite Deformation and Shear Effects

    Institute of Scientific and Technical Information of China (English)

    李晶晶; 程昌钧; 张能辉

    2002-01-01

    Based on Reddy' s theory of plates with higher-order shear deformations and the Boltzmann superposition principles, thegoverning equations were established for dynamic stability of viscoelastic plates with finite deformations taking account of shear ef-fects. The Galerkin method was applied to simplify the set of equations. The numerical methods in nonlinear dynamics were used tosolve the simplified system. It could be seen that there are plenty of dynamic properties for this kind of viscoelastic plates under trans-verse harmonic loads. The influences of the transverse shear deformations and material parameter on the dynamic behavior of nonlin-ear viscoelastic plates were investigated.

  2. Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100 °C to 1250 °C

    DEFF Research Database (Denmark)

    Alfonso Lopez, Angel; Juul Jensen, Dorte; Luo, G.-N.

    2015-01-01

    Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high...... suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation....

  3. Preliminary results of Resistive Plate Chambers operated with eco-friendly gas mixtures for application in the CMS experiment

    CERN Document Server

    Abbrescia, M

    2016-01-01

    The operations of Resistive Plate Chambers in LHC experiments require Fluorine based (F-based) gases for optimal performance. Recent European regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. In view of the CMS experiment upgrade, several tests are ongoing to measure the performance of the detector with these new ecological gas mixtures, in terms of efficiency, streamer probability, induced charge and time resolution. Prototype chambers with readout pads and with the standard CMS electronic setup are under test. In this paper preliminary results on performance of RPCs operated with a potential eco-friendly gas candidate 1,3,3,3-Tetrafluoropropene, commercially known as HFO-1234ze, with CO2 and CF3I based gas mixtures are presented and discussed for the possible application in the CMS experiment.

  4. Preliminary results of Resistive Plate Chambers operated with eco-friendly gas mixtures for application in the CMS experiment

    CERN Document Server

    Abbrescia, Marcello; Benussi, Luigi; Bianco, Stefano; Cauwenbergh, Simon Marc D; Ferrini, Mauro; Muhammad, Saleh; Passamontic, L; Pierluigi, Daniele; Piccolo, Davide; Primavera, Federica; Russo, Alessandro; Savianoc, G; Tytgat, Michael

    2016-01-01

    The operations of Resistive Plate Chambers in LHC experiments require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. In view of the CMS experiment upgrade several tests are ongoing to measure the performance of the detector in terms of efficiency, streamer probability, induced charge and time resolution. Prototype chambers with readout pads and with the standard cms electronic setup are under test. In this talk preliminary results on performance of RPCs operated with a potential eco-friendly gas candidate 1,3,3,3-Tetrafluoropropene, commercially known as HFO-1234ze and with CO2 based gas mixtures are presented and discussed for the possible application in the CMS experiment.

  5. ITER Vertical Stability Guidance from Multi-machine Experiments

    Science.gov (United States)

    Humphreys, D. A.; Eidietis, N.; Jackson, G. L.; Leuer, J. A.; Walker, M. L.; Welander, A. S.; Casper, T. A.; Lodestro, L. L.; Meyer, W. H.; Pearlstein, L. D.; Ferrara, M.; Hutchinson, I. H.; Wolfe, S. M.; Gates, D. A.; Kolemen, E.; Lister, J.; Sartori, F.; Treutterer, W.

    2008-11-01

    Sufficiently robust vertical stability control is critical to ITER, in which the consequences of a vertical displacement event (VDE) disruption can be very severe. Experimental results from many devices have provided guidance to determine the necessary level of robustness, and theoretical analysis has quantified the tradeoffs inherent in various design choices. The maximum controllable displacement normalized by minor radius is shown to be a useful metric for performance, and must be greater than 4% for robustness to VDEs in operating machines. Analysis of controllability limits, axisymmetric control performance, noise environments, and disturbances in operating devices including Alcator C-Mod, DIII-D, NSTX, TCV, and JET will be presented.

  6. A single Time-of-Flight tray based on multigap resistive plate chambers for the STAR experiment at RHIC

    Science.gov (United States)

    Bonner, B.; Chen, H.; Eppley, G.; Geurts, F.; Lamas-Valverde, J.; Li, Ch.; Llope, W. J.; Nussbaum, T.; Platner, E.; Roberts, J.

    2003-08-01

    The STAR experiment at RHIC plans to implement a 60 m2 Time-of-Flight (TOF) system. The Multigap Resistive Plate Chamber (MRPC) is a suitable candidate for the STAR TOF system due to its time resolution of order of 60 ps with efficiencies in excess of 97%. We obtained this result with modules composed of 6 gas gaps of 220 μm and pad area of 20 cm2. In this paper, we report on the performance of this MRPC module and present the current status of the construction and installation into STAR of a prototype tray.

  7. Long Term Stability of Coriolis Flow Meters: DESY experience

    Science.gov (United States)

    Boeckmann, T.; Bozhko, Y.; Escherich, K.; Petersen, B.; Putselyk, S.; Schnautz, T.; Sellmann, D.; Zhirnov, A.

    2017-02-01

    The measurement of coolant flow is important operational parameter for reliable operation of cryogenic system with superconducting magnets or cavities as well as for the system diagnostics in case of non-steady-state operation, e.g. during cool-down/warm-up or other transients. Proper flowmeter is chosen according to the different parameters, e.g. turn-down, operating temperature range, leak-tightness, pressure losses, long-term stability, etc. For helium cryogenics, the Venturi tube or Orifice, as well as Coriolis flow meters are often applied. For the present time, the orifices are usually used due to their simplicity and low costs, however, low turn-down range, large pressure drop, restriction of flow area, susceptibility to thermoacoustic oscillations limit their useful operation range. Operational characteristics of Venturi tubes is substantially improved in comparison to orifices, however, relative high costs and susceptibility to thermoacoustic oscillations still limit their application to special cases. The Coriolis flow meters do not have typical drawbacks of Venturi tube and orifices, however long-term stability over many years was not demonstrated yet. This paper describes the long-term behaviour of Coriolis flow meters after many years of operation at AMTF and XMTS facilities.

  8. Experiment and simulation analysis of roll-bonded Q235 steel plate

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, G.; Huang, Q.; Zhou, C.; Zhang, Z.; Ma, L.; Wang, X.

    2016-10-01

    Heavy-gauge Q235 steel plate was roll bonded, and the process was simulated using MARC software. Ultrasonic testing results revealed the presence of cracks and lamination defects in an 80-mm clad steel sheet, especially at the head and tail of the steel plate. There were non-uniform ferrite + pearlite microstructures and unbound areas at a bond interface. Through scanning electron microscopy analysis, long cracks and additional inclusions in the cracks were observed at the interface. A fracture analysis revealed non-uniform inclusions that pervaded the interface. Moreover, MARC simulations demonstrated that there was little equivalent strain at the centre of the slab during the first rolling pass. The equivalent centre increased to 0.5 by the fourth rolling pass. Prior to the final pass, the equivalent strain was not consistent across the thickness direction, preventing bonding interfaces from forming consistent deformation and decreasing the residual stress. The initial rolling reduction rate should not be very small (e.g. 5%) as it is averse to the coordination of rolling deformation. Such rolling processes are averse to the rolling bond. (Author)

  9. Relaminarization of the boundary layer over a flat plate in shock tube experiments

    Science.gov (United States)

    Hinckel, J. N.; Nagamatsu, H. T.

    1986-01-01

    The relaminarization of the boundary layer over a flat plate in the shock tube was investigated by using the partially reflected shock wave technique. The flow Mach number was approximately 0.14, which corresponds to the inleft flow Mach number for the first row of vanes in a gas turbine. The thin film platinum heat gauges were used to measure the heat transfer rate and the Stanton number was calculated from the oscilloscope voltage traces. The Reynolds number was varied by changing the operation pressure of the shock tube and the values varied from 2.3 x 10 to the 4th to 5.3 x 10 to the 5th. For a Reynolds number range of 7 x 10 to the 4th to 3.5 x 10 to the 5th, the relaminarization of the boundary layer was observed. This phenomenon is due to the decay of the turbulence level in the flow as the reflected shock wave moves upstream from the flat plate. As the Reynolds number increased, the relaminarization was delayed and the delay was related to the turbulence generated by the reflected shock wave.

  10. Multi-axis force sensing using a resonant composite piezoelectric plate: model and experiments

    Science.gov (United States)

    Castaño-Cano, Davinson; Grossard, Mathieu; Hubert, Arnaud

    2015-05-01

    Wrist force/torque sensors used in robotic applications increase the performances and flexibility of the automated tasks. They also offer new possibilities in the manufacturing process, where physical contact between the work-piece and environment is required. The wide spreading of these sensors is for now restricted by their features. As an alternative to the existing strain-gauges force sensors, this paper presents a resonant composite structure, which is sensitive to multiple components of force that are considered via the pre-stress effect. Structurally bonded piezoelectric patches are used to bring the structure to its resonance, which is shifted according to applied forces. The relationship between force and frequency shift is modelled considering the multi-physics of this smart structure. This model is built using Hamilton's principle and takes into account pre-stress phenomena. A finite element model (FEM) based on Mindlin theory for plates, has been derived from the analytical model. The FEM model is implemented in MATLAB and compared with commercial FE software. Finally, an experimental prototype validates the model, and shows that it is possible to measure multiple force-components with one single sensing element such as a plate.

  11. Processless offset printing plates

    Directory of Open Access Journals (Sweden)

    Sanja Mahović Poljaček

    2015-06-01

    Full Text Available With the implementation of platesetters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today. This paper presents some of the processless printing plates.

  12. Theory, Computation and Experiment on Criticality and Stability of Vortices Separating from Edges

    Science.gov (United States)

    2016-08-15

    AFRL-AFOSR-VA-TR-2016-0313 Theory, computation and experiment on criticality and stability of vortices separating from edges Ashok Gopalarathnam...computation and experiment on criticality and stability of vortices separating from edges 5a. CONTRACT NUMBER - 5b. GRANT NUMBER FA9550-13-1-0179...leading-edge suction on a finite wing reaches a critical value, LEV initiation takes place. The critical value is the same as that for the corresponding

  13. Oblique Plate Impact Experiments to Study the Compression-Shear Behavior of the HMX Based Explosive PBX 9501

    Science.gov (United States)

    Reinhart, William; Gustavsen, Rick; Vogler, Tracy; Alexander, Scott; Thornhill, Tom; Clements, Brad; Bartram, Brian; SNL/LANL Collaboration

    2013-06-01

    HMX (cyclotetramethylene-tetranitramine) based explosive, PBX 9501, is a conventional high explosive formulation composed of 95% wt. of HMX and 5% binders. A series of experiments were performed to investigate one-dimensional combined pressure-shear waves in PBX-9501. This study is thought to be the first to estimate shear stress and strength in a plastic bonded high explosive. Experiments were conducted using Sandia National Laboratories oblique launcher at the Shock Thermodynamics Applied Research (STAR) facility. A projectile is keyed to a slot in the launcher barrel in order to prevent rotation. The projectile is faced with a titanium alloy plate inclined at 20 degrees to the launcher axis. The target consists of a 1 mm thick PBX 9501 disk sandwiched between two titanium alloy plates. Measurements of shear and longitudinal particle velocities were used to determine stresses and infer strength. Longitudinal stresses from 1.4 to 3.1 GPa were applied which presented corresponding shear stresses of 0.1 to 0.23 GPa at high shearing strain rates up to 0.4 x 105s-1. This experimental data now provides for the first time, relevant information for model development.

  14. Experiments on forced convection form a horizontal heated plate in a packed bed of glass spheres

    Energy Technology Data Exchange (ETDEWEB)

    Renken, K.J. (Univ. of Wisconsin, Milwaukee (USA)); Poulikakos, D. (Univ. of Illinois, Chicago (USA))

    1989-02-01

    This paper presents an experimental investigation of boundary-layer forced convective heat transfer from a flat isothermal plate in a packed bed of spheres. Extensive experimental results are reported for the thermal boundary-layer thickness, the temperature field, and the local wall heat flux (represented by the local Nusselt number). Theoretical findings of previous investigations using the Darcy flow model as well as a general model for themomentum equation accouting for flow inertia and macroscopic shear wtih and without variable porosity are used to evaluate the theoretical models. Several trends are revealed regarding the conditions of validity of these flow models. Overall the general flow model including variable porosity appears to perform better, even through the need for serious improvements in modeling becomes apparent.

  15. Radiographic evaluation of fracture healing after rigid plate fixation. Experiments in the rabbit

    Energy Technology Data Exchange (ETDEWEB)

    Paavolainen, P.; Karaharju, E.; Slaetis, P.; Waris, P. (Helsinki Univ. Central Hospital (Finland). Meilahti Clinic)

    1981-01-01

    Experimental osteotomies were made in 35 rabbit tibio-fibular bones and fixed with rigid stainless steel osteosynthesis plates (DCP/ASIF). The radiographic and histopathologic appearances in the healing osteotomies and adjacent bone were analysed at intervals from 3 up to 24 weeks postoperatively. Radiologically the osteotomy had closed at 9 weeks and microscopically this could be confirmed as longitudinal orientation of the cutter heads across the osteotomy gap with longitudinal orientation of the bone structure. The healing of the osteotomy was accompanied by gross structural changes in the adjacent cortical bone with loss of intracortical and subendosteal osteons, cementing lines and intermediate tissue between the osteons. This was characterized by decreasing attenuation of the cortical bone after healing of the osteotomy and should clinically be regarded as an indication for removal of the implant.

  16. 化学镀镍施镀过程稳定性分析%Evaluation on Plating Stability in Electroless Nickel Deposition

    Institute of Scientific and Technical Information of China (English)

    陈月华; 刘永永; 江德凤; 袁礼华

    2013-01-01

    Based on the action mechanism of electroless nickel deposition, the factors affecting the stability of the plating solution, such as salinity ( nickelous sulfate and sodium hypophosphite) , pH value, temperature and operating methods were analyzed. It is indicated that when the concentration of Nickel and hypophosphite acid is 5. 8 g/L and 17.4 g/L respectively, and pH value is 4. 4, the best plating stability can be achieved under 82 ℃.%以化学镀镍反应机理为依据,针对一种酸性化学镀镍体系,就主盐浓度(硫酸镍)、还原剂(次磷酸钠)、pH值、温度等因素对施镀过程中镀液稳定性的影响进行了分析.结果表明:在Ni2+质量浓度5.8 g/L、H2PO2-质量浓度17.4 g/L、pH值4.4、温度82℃的条件下施镀,化学镀镍施镀过程稳定性最佳.

  17. Stabilization of the CORA based leveling osteotomy for treatment of cranial cruciate ligament injury using a bone plate augmented with a headless compression screw.

    Science.gov (United States)

    Raske, Matthew; Hulse, Don; Beale, Brian; Saunders, W Brian; Kishi, Erin; Kunze, Christopher

    2013-08-01

    To report the effectiveness of a bone plate/headless compression screw (HCS) construct in preventing tibial plateau angle (TPA) shift postoperatively and to describe radiographic healing of the osteotomy. Case series. Dogs (n = 31). Records of dogs diagnosed with cranial cruciate ligament (CCL) injury treated with the center of rotation of angulation (CORA) based leveling osteotomy (CBLO) stabilized with a bone plate augmented with a HCS were reviewed. Breed, age, weight, and gender were recorded. Radiographs were reviewed for determination of preoperative tibial plateau angle (PreTPA), postoperative TPA (PostTPA), patellar tendon angle (PTA) postoperatively, and TPA at final evaluation (FinalTPA). Difference between PostTPA and FinalTPA was used to define any TPA shift. Radiographic healing at final evaluation was graded based on a 5-point scale. Mean time to final recheck was 88 days (range 49-237 days) with mean ± SD PreTPA = 28.6 ± 4.8°; PostTPA = 9.2 ± 2.2°; FinalTPA = 9.7 ± 2.6°; and TPA Shift = 0.52 ± 1.61°. There was no significant difference between PostTPA and FinalTPA (P = .084, power > 0.80). Mean postoperative PTA was 89.9 ± 1.7°. There were 2 implant related complications; 1 HCS migration and 1 HCS failure. Stabilization of the CBLO using a bone plate augmented with a HCS was effective in maintaining PostTPA and achieving satisfactory radiographic healing. © Copyright 2013 by The American College of Veterinary Surgeons.

  18. Aespoe Pillar Stability Experiment. Final experiment design, monitoring results and observations

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Christer [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Eng, Anders [Acuo Engineering AB, Linkoeping (Sweden)

    2005-12-15

    The field part of the Aespoe Pillar Stability Experiment at the Aespoe Hard Rock Laboratory (HRL) was finished in 2004. The experiment was designed to induce and monitor the process of brittle failure, spalling, in a fractured rock mass under controlled conditions. The field part was successfully conducted and a large data set was obtained. This report presents the final design of the experiment, the results of the monitoring, and the observations made during the spalling process and when the spalled rock was removed. When heating of the rock was initiated the rock responded quickly. After only a few days the spalling process was activated in the notch, as indicated by the acoustic emission system, and shortly thereafter displacement readings were recorded. Contraction (radial expansion) of the rock was recorded by several instruments before the notch reached the instrument levels. This contraction is probably the result of a 3D re-distribution of the stresses. The temperature increase in the system was both slower and reached a steady state much earlier than predicted by the numerical models. The propagation of the notch was therefore halted after approximately one month of heating. The power to the electrical heaters was therefore doubled. Spalling then started up again, and in one month's time it had propagated to a depth of approximately five metres in the hole. A second steady state was now reached, but this time the heater power was kept constant for a while to let the rock settle before the confinement pressure was reduced from 700 kPa to 0 in decrements of 50 kPa. The rock mass response to the pressure drop was very limited until the pressure was lowered to approximately 200 kPa (the atmospheric pressure is not included in the given pressure values). Large displacements and a high acoustic emission hit frequency were then measured in the open hole. After the de-pressurization of the confined hole, the heaters were left on for approximately one week

  19. Study of timing response and charge spectra of glass based Resistive Plate Chamber detectors for INO-ICAL experiment

    Science.gov (United States)

    Gaur, A.; Kumar, A.; Naimuddin, Md.

    2017-03-01

    Resistive Plate chambers (RPCs) are robust and affordable gaseous detectors that combine low cost with excellent timing, good spatial resolution and fast response to the incoming particles. The India Based Neutrino Observatory is an approved project aimed at building a magnetised Iron Calorimeter (ICAL) detector to study Neutrino physics and related issues. The ICAL experiment will utilize about 29000 RPC's as active detector elements, sandwiched between alternate plates of thick iron. The RPC detectors will be used to detect muons produced from the atmospheric neutrinos interaction with an iron target. The spatial information of the muons will be extracted from the two dimensional readout and the hit position in the respective layers. The up going and down going directionality will be obtained using the time stamp of hits in the active detectors. The charge induced by the particle and its behaviour with respect to the applied voltage play a significant role in designing the readout electronics for the detector. In this paper, we present the timing and charge measurement of single gap glass based RPC detectors. We will also report about studies on the dependence of the timing and charge response of these RPC detectors as a function of the gas composition.

  20. Experiment and simulation analysis of roll-bonded Q235 steel plate

    Directory of Open Access Journals (Sweden)

    Zhao, Guanghui

    2016-06-01

    Full Text Available Heavy-gauge Q235 steel plate was roll bonded, and the process was simulated using MARC software. Ultrasonic testing results revealed the presence of cracks and lamination defects in an 80-mm clad steel sheet, especially at the head and tail of the steel plate. There were non-uniform ferrite + pearlite microstructures and unbound areas at a bond interface. Through scanning electron microscopy analysis, long cracks and additional inclusions in the cracks were observed at the interface. A fracture analysis revealed non-uniform inclusions that pervaded the interface. Moreover, MARC simulations demonstrated that there was little equivalent strain at the centre of the slab during the first rolling pass. The equivalent centre increased to 0.5 by the fourth rolling pass. Prior to the final pass, the equivalent strain was not consistent across the thickness direction, preventing bonding interfaces from forming consistent deformation and decreasing the residual stress. The initial rolling reduction rate should not be very small (e.g. 5% as it is averse to the coordination of rolling deformation. Such rolling processes are averse to the rolling bond.Planchas de acero Q235 de espesor grueso se unieron mediante laminación y el proceso fue simulado numéricamente utilizando el programa de cálculo MARC. Los resultados obtenidos en ensayos mediante ultrasonidos revelaron la presencia de grietas y defectos en la laminación en una plancha de acero revestido de 80 mm, especialmente en el comienzo y final de la plancha. La microestructura consistía en ferrita+perlita y desunión en la interfase de unión. Mediante análisis por microscopía electrónica de barrido se observó que la interfase contenía grietas con inclusiones. Un análisis de la fractura reveló la presencia de inclusiones no uniformes en la interfase. Además, los datos de simulación utilizando el programa MARC demostraron que había poca tensión equivalente en el centro de la plancha

  1. A large-scale forest fragmentation experiment: the Stability of Altered Forest Ecosystems Project

    OpenAIRE

    Ewers, Robert M.; Didham, Raphael K.; Fahrig, Lenore; Ferraz, Gonçalo; Hector, Andy; Holt, Robert D; Kapos, Valerie; Reynolds, Glen; Sinun, Waidi; Snaddon, Jake L.; Turner, Edgar C.

    2011-01-01

    Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity to reveal the complex processes that operate within natural ecosystems. Here, we review the design of existing, large-scale forest fragmentation experiments. Based on this review, we develop a design for the Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experiment to be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project repres...

  2. An optimized process for the production of advanced planar wire grid plates as detectors for high energy physics experiments

    CERN Document Server

    Iacopi, F; Pins, R; Van Hook, R I; Honore, M; Zhukov, V; Van Lancker, L; Van Doninck, W K; Beyne, E

    2001-01-01

    This paper introduces a novel production technique for the planar wire grid plates of microstrip gas chambers (MSGCs, gaseous particle detectors), taking advantage from the typical thin film metallization technologies. The aim of the work here presented has been to manufacture MSGC substrates which can meet the challenging requirements proper to particle tracking detectors in highly ionizing environments. These requirements are mainly represented by high reliability and robustness, since the devices are supposed to operate efficiently for at least 10 years in the extremely hostile conditions foreseen at the large hadron collider at CERN (CH). A detailed process description will be given and results will be analyzed both from the production point of view and from the application of the manufactured prototypes as detectors for high energy physics experiments. (7 refs).

  3. An analytical model for the prediction of the dynamic response of premixed flames stabilized on a heat-conducting perforated plate

    KAUST Repository

    Kedia, Kushal S.

    2013-01-01

    The dynamic response of a premixed flame stabilized on a heat-conducting perforated plate depends critically on their coupled thermal interaction. The objective of this paper is to develop an analytical model to capture this coupling. The model predicts the mean flame base standoff distance; the flame base area, curvature and speed; and the burner plate temperature given the operating conditions; the mean velocity, temperature and equivalence ratio of the reactants; thermal conductivity and the perforation ratio of the burner. This coupled model is combined with our flame transfer function (FTF) model to predict the dynamic response of the flame to velocity perturbations. We show that modeling the thermal coupling between the flame and the burner, while accounting for the two-dimensionality of the former, is critical to predicting the dynamic response characteristics such as the overshoot in the gain curve (resonant condition) and the phase delay. Good agreement with the numerical and experimental results is demonstrated over a range of conditions. © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  4. Metamorphic sole formation and early plate interface rheology: Insights from Griggs apparatus experiments

    Science.gov (United States)

    Soret, Mathieu; Agard, Philippe; Dubacq, Benoît; Hirth, Greg; Yamato, Philippe; Ildefonse, Benoît; Prigent, Cécile

    2016-04-01

    Metamorphic soles correspond to m to ~500 m thick highly strained metamorphic rock units found beneath mylonitic banded peridotites at the base of large-scale ophiolites, as exemplified in Oman. Metamorphic soles are mainly composed of metabasalts deriving from the downgoing oceanic lithosphere and metamorphosed up to granulite-facies conditions by heat transfer from the mantle wedge. Pressure-temperature peak conditions are usually estimated at 1.0±0.2 GPa and 800±100°C. The absence of HP-LT metamorphism overprint implies that metamorphic soles have been formed and exhumed during subduction infancy. In this view, metamorphic soles were strongly deformed during their accretion to the mantle wedge (corresponding, now, to the base of the ophiolite). Therefore, metamorphic soles and banded peridotites are direct witnesses of the dynamics of early subduction zones, in terms of thermal structure, fluid migration and rheology evolution across the nascent slab interface. Based on fieldwork and EBSD analyses, we present a detailed (micro-) structural study performed on samples coming from the Sumeini window, the better-preserved cross-section of the metamorphic sole of Oman. Large differences are found in the deformation (CPO, grain size, aspect ratio) of clinopyroxene, amphibole and plagioclase, related to mineralogical changes linked with the distance to the peridotite contact (e.g., hardening due to the appearance of garnet and clinopyroxene). To model the incipient slab interface in laboratory, we carried out 5 hydrostatic annealing and simple-shear experiments on Griggs solid-medium apparatus. Deformation experiments were conducted at axial strain rates of 10-6 s-1. Fine-grained amphibolite was synthetized by adding 1 wt.% water to a (Mid-Ocean Ridge) basalt powder as a proxy for the metamorphic sole (amphibole + plagioclase + clinopyroxene ± garnet assemblage). To synthetize garnet, 2 experiments were carried out in hydrostatic conditions and with deformation at

  5. Feasibility experiment for Active Monitoring of Inter-plate Coupling in Tokai region. ---A dense array measurement---

    Science.gov (United States)

    Watanabe, T.; Ikuta, R.; Soma, T.; Saiga, A.; Miyajima, R.; Fujii, N.; Yamaoka, K.; Tsuruga, K.; Kunitomo, T.; Hasada, Y.; Kasahara, J.; Kumazawa, M.; Satomura, M.

    2005-12-01

    We carried out a long-distance seismic monitoring experiment using ACROSS (Accurately Controlled and Routinely Operated Signal System) for 10 months starting from the end of 2004 in Tokai region central Japan. In this experiment, we attempted to detect reflected phases from the top surface of the subducting Philippine Sea plate and to detect their temporal changes. In the Tokai region, a seismic survey was conducted in 2001. A strong reflected phase was detected and was interpreted as a reflection from the boundary between subducting and overriding plate [Iidaka, 2003]. Yoshida et al. [2004] analyzed the ACROSS signal received by a nationwide seismic network (Hi-net) and identified several phases which may include the direct waves and reflected phases from the plate boundary. The aim of our research is to confirm the reflected phases and also to detect temporal changes in properties of them. The ACROSS source was continuously operated in Toki City, Gifu prefecture by Tono Geoscience Center. The frequency-modulated signal with frequency band from10 to 20 Hz was precisely repeated with an interval of 50 seconds. As the rotation direction of the source reverses once per hour, we can synthesize linear vibration in any direction. Seismometers were deployed on a survey line between 40 and 70 km distance to the southeast from the source. We also deployed an array consisted by 12 seismometers having 2km aperture at 55 km away from the source on the survey line. We acquired seismograms with the array and stacked to improve S/N ratio. In ACROSS data analysis, we can estimate the errors of the received signals quantitatively in the frequency domain. We stacked the received signals weighted by inverse of the estimated errors in order to reduce the effect of the incidental noises such as earthquakes. We converted the stacked spectral signals into a frequency response by dividing them by the source spectra. Through applying an inverse Fourier transform to the frequency response

  6. Menu-engineering in restaurants - adapting portion sizes on plates to enhance vegetable consumption: a real-life experiment.

    Science.gov (United States)

    Reinders, Machiel J; Huitink, Marlijn; Dijkstra, S Coosje; Maaskant, Anna J; Heijnen, Joris

    2017-12-25

    The aim of this research was to investigate whether increased portion sizes of vegetables and decreased portion sizes of meat on main dishes increased the amount of vegetables consumed in a real-life restaurant setting without affecting customer satisfaction. The participants were unaware of the experiment. A cross-over design was used in which three restaurants were randomly assigned to a sequence of an intervention and control condition. In the intervention period, the vegetable portion sizes on the plates of main dishes were doubled (150 g of vegetables instead of 75 g) and the portion sizes of meat on the plates were reduced by an average of 12.5%. In the control period, the portion sizes of the main dishes were maintained as usual. In total, 1006 observations and questionnaires were included. Vegetable consumption from plates was significantly higher during the intervention period (M = 115.5 g) than during the control period (M = 61.7 g). Similarly, total vegetable consumption (including side dishes) was significantly higher during the intervention period (M = 178.0 g) than during the control period (M = 137.0 g). Conversely, meat consumption was significantly lower during the intervention period (M = 183.1 g) than during the control period (M = 211.1 g). Satisfaction with the restaurant visit did not differ between the intervention period (M = 1.27) and control period (M = 1.35). Satisfaction with the main dish was significantly lower during the intervention period (M = 1.25) than during the control period (M = 1.38), although in both cases, the scores indicated that participants remained (very) satisfied with their main dish. This study showed that increasing vegetable portions in combination with decreasing meat portions (unknowingly to the consumer) increased the amount of vegetables consumed and decreased the amount of meat consumed. Furthermore, despite the changes in portion sizes, participants remained satisfied

  7. Application of high stability oscillators to radio science experiments using deep space probes

    Science.gov (United States)

    Kursinski, Emil R.

    1990-01-01

    The microwave telecommunication links between the earth and deep space probes have long been used to conduct radio science experiments which take advantage of the phase coherency and stability of these links. These experiments measure changes in the phase delay of the signals to infer electrical, magnetic and gravitational properties of the solar system environment and beyond through which the spacecraft and radio signals pass. The precision oscillators, from which the phase of the microwave signals are derived, play a key role in the stability of these links and therefore the sensitivity of these measurements. These experiments have become a driving force behind recent and future improvements in the Deep Space Network and spacecraft oscillators and frequency and time distribution systems. Three such experiments which are key to these improvements are briefly discussed and relationship between their sensitivity and the signal phase stability is described. The first is the remote sensing of planetary atmospheres by occultation in which the radio signal passes through the atmosphere and is refracted causing the signal pathlength to change from which the pressure and the temperature of the atmosphere can be derived. The second experiment is determination of the opacity of planetary rings by passage of the radio signals through the rings. The third experiment is the research for very low frequency gravitational radiation. The fractional frequency variation of the signal is comparable to the spatial strain amplitude the system is capable of detecting. A summary of past results and future possibilities for these experiments are presented.

  8. Application of high stability oscillators to radio science experiments using deep space probes

    Science.gov (United States)

    Kursinski, Emil R.

    1990-01-01

    The microwave telecommunication links between the earth and deep space probes have long been used to conduct radio science experiments which take advantage of the phase coherency and stability of these links. These experiments measure changes in the phase delay of the signals to infer electrical, magnetic and gravitational properties of the solar system environment and beyond through which the spacecraft and radio signals pass. The precision oscillators, from which the phase of the microwave signals are derived, play a key role in the stability of these links and therefore the sensitivity of these measurements. These experiments have become a driving force behind recent and future improvements in the Deep Space Network and spacecraft oscillators and frequency and time distribution systems. Three such experiments which are key to these improvements are briefly discussed and relationship between their sensitivity and the signal phase stability is described. The first is the remote sensing of planetary atmospheres by occultation in which the radio signal passes through the atmosphere and is refracted causing the signal pathlength to change from which the pressure and the temperature of the atmosphere can be derived. The second experiment is determination of the opacity of planetary rings by passage of the radio signals through the rings. The third experiment is the research for very low frequency gravitational radiation. The fractional frequency variation of the signal is comparable to the spatial strain amplitude the system is capable of detecting. A summary of past results and future possibilities for these experiments are presented.

  9. Control-based continuation: Bifurcation and stability analysis for physical experiments

    Science.gov (United States)

    Barton, David A. W.

    2017-02-01

    Control-based continuation is technique for tracking the solutions and bifurcations of nonlinear experiments. The idea is to apply the method of numerical continuation to a feedback-controlled physical experiment such that the control becomes non-invasive. Since in an experiment it is not (generally) possible to set the state of the system directly, the control target becomes a proxy for the state. Control-based continuation enables the systematic investigation of the bifurcation structure of a physical system, much like if it was numerical model. However, stability information (and hence bifurcation detection and classification) is not readily available due to the presence of stabilising feedback control. This paper uses a periodic auto-regressive model with exogenous inputs (ARX) to approximate the time-varying linearisation of the experiment around a particular periodic orbit, thus providing the missing stability information. This method is demonstrated using a physical nonlinear tuned mass damper.

  10. Transient Stability Analysis of the SeCRETS Experiment in SULTAN

    CERN Document Server

    Bottura, L; Marinucci, C

    2002-01-01

    We present here the results of the analysis of the stability experiment SeCRETS, performed on two Nb3Sn cable-in-conduit conductors with the same amount of total copper stabilizer, but different degree of segregation. The model used for the analysis, including superconducting strands, conductor jacket and helium, is solved with the code GandalfTM. We obtain a qualitative agreement of simulation results and experimental values. The simulation results confirm that in the operation regime explored in the experiment the segregated copper is not effective for stability. The details of the current sharing and the approximation taken for the transient heat transfer are shown to be critical for the interpretation.

  11. Glow experiment documentation of OMS/RCS pods and vertical stabilizer

    Science.gov (United States)

    1982-01-01

    Glow experiment documentation of orbital maneuvering system (OMS) reaction control system (RCS) pods and vertical stabilizer shows chemoluminescent effect resulting from atomic oxygen impacting the spacecraft and building to the point that the atomic oxygen atoms combine to form molecules of oxygen. Image intensifier on NIKON 35mm camera used to record glow on vertical tail and OMS pods.

  12. Glow experiment documentation of OMS/RCS pod and vertical stabilizer

    Science.gov (United States)

    1982-01-01

    Glow experiment documentation of one of the orbital maneuvering system (OMS) reaction control system (RCS) pods and a portion of the vertical stabilizer shows chemoluminescent effectresulting from atomic oxygen impacting the spacecraft and building to the point that the atomic oxygen atoms combine to form molecules of oxygen. The Image Intensifier on NIKON 35mm camera was used to record the glow.

  13. Early results of reverse less invasive stabilization system plating in treating elderly intertrochanteric fractures: a prospective study compared to proximal femoral nail

    Institute of Scientific and Technical Information of China (English)

    YAO Chen; ZHANG Chang-qing; JIN Dong-xu; CHEN Yun-feng

    2011-01-01

    Background Intertrochanteric femur fracture is common in elderly population. Though multiple treatment options are available, the choice of implant remains controversial. The reverse less invasive stabilization system (LISS) plating was introduced for treatment of a patient with ipsilateral intertrochanteric and midshaft femoral fractures. The aim of this research was to compare such technique to intramedullary nailing (proximal femoral nail, PFN) for intertrochanteric fractures.Methods Fifty-six patients with an age of at least sixty-five years and an AO/OTA type-A1 or A2 fractures were included and divided into LISS and PFN treatment group. Background parameters, fracture and surgery details were documented. Follow-up time was at least 12 months. Radiology, complication, Harris Hip Score and Rapid Disability Rating Score (RDRS) were recorded to evaluate fixation status and hip function for each patient during follow-up.Results There was no significant difference between the two groups in surgical time ((48.0±8.6) minutes, vs.(51.8±10.8) minutes, P=0.3836) and intraoperative blood loss ((149.1±45.1) ml vs. (176.4±25.4) ml, P=0.0712). The LISS group had less postoperative haemoglobin (Hb) reduction ((10.2±4.5) g/L Hb, vs. (15.1~5.9) g/L Hb, P=0.0475). There was no complication observed in PFN group. All 31A1 type fracture in LISS group showed 100% maintenance of reduction. One nonunion with locking screw breakage and 2 varus union were found in the LISS group. Postoperative hip function was similar between the two groups.Conclusions Though reverse LISS plating may not be recommended as a routine fixation method for elderly unstable intertrochanteric fractures compared to PFN, it may possibly be reserved for rapid fixation and damage control in polytrauma patients and ORIF of subtrochanteric and reverse oblique intertrochanteric fractures.

  14. 化学镀镍复合添加剂BH的工艺特性%Technological properties of composite stabilizer BH for electroless nickel plating

    Institute of Scientific and Technical Information of China (English)

    鹿轩; 梁颖诗; 张晓明; 林继月; 胡耀红; 赵国鹏

    2013-01-01

    开发了一种由含钼化合物、碘化钾以及邻苯二甲酸酐衍生物组成的复合添加剂BH,讨论了它对化学镀镍液稳定性、镀速以及镀层磷含量、硬度、孔隙率和微观形貌的影响。对测试化学镀镍液稳定性的PdCl2试验标准进行了改进:温度由80°C提高到90°C,PdCl2的浓度由0.1 g/L增加到1.0 g/L。研究结果显示,新标准检验的镀液稳定性差异能较好地反映实际生产中的镀液稳定性差异;当复合添加剂BH的添加量为2.0 mL/L时,化学镀镍层微观形貌得到较大的改善。经过新的PdCl2试验标准检验,该镀液可达到900 s不发生浑浊,镀速为24μm/h,镀层孔隙率0.57个/cm2,磷含量7.3%,硬度520 HV。%A composite additive BH consisting of molybdenum-containing compound, potassium iodide, and phthalic anhydride derivative was developed, and its influence on the stability and deposition rate of electroless nickel plating bath, as well as the phosphorus content, hardness, porosity, and micro-morphology of deposit was discussed. The PdCl2 test standard used for determining stability of electroless nickel plating bath was improved as follows: increasing temperature from 80 °C to 90 °C and PdCl2 concentration from 0.1 g/L to 1.0 g/L. The results indicated that the difference of bath stability tested by the improved method has good relevance with that in practical production. The electroless nickel plating bath with composite additive BH 2.0 mL/L remains stable within 900 s without becoming turbid by testing based on the improved method and produces electroless nickel coatings with improved micro-morphologies at a deposition rate of 24μm/h.The electroless nickel coating obtained has a porosity 0.57 pores/cm2, phosphorus content 7.3%and hardness 520 HV.

  15. Orifice plate cavitation mechanism and its influencing factors

    Directory of Open Access Journals (Sweden)

    Wan-zheng AI

    2010-09-01

    Full Text Available The orifice plate energy dissipater is an economic and highly efficient dissipater. However, there is a risk of cavitaion around the orifice plate flow. In order to provide references for engineering practice, we examined the cavitation mechanism around the orifice plate and its influencing factors by utilizing mathematical analysis methods to analyze the flow conditions around the orifice plate in view of gas bubble dynamics. Through the research presented in this paper, the following can be observed: The critical radius and the critical pressure of the gas nucleus in orifice plate flow increase with its initial state parameter ; the development speed of bubbles stabilizes at a certain value after experiencing a peak value and a small valley value; and the orifice plate cavitation is closely related to the distribution of the gas nucleus in flow. For computing the orifice plate cavitation number, we ought to take into account the effects of pressure fluctuation. The development time of the gas nucleus from the initial radius to the critical radius is about 10-7-10-5 s; therefore, the gas nucleus has sufficient time to develop into bubbles in the negative half-cycle of flow fluctuation. The orifice critical cavitation number is closely related to the orifice plate size, and especially closely related with the ratio of the orifice plate radius to the tunnel radius. The approximate formula for the critical cavitation number of the square orifice plate that only considers the main influencing factor was obtained by model experiments.

  16. Plasma stabilization experiment. First technical report, 1 May 1979-30 September 1979

    Energy Technology Data Exchange (ETDEWEB)

    Sziklas, E. A.; Fader, W. J.; Jong, R. A.; Polk, D. H.; Stufflebeam, J. H.

    1979-10-01

    The Plasma Stabilization Experiment is an effort to enhance stability in a mirror-confined plasma by stoppering cold ions with rf fields applied near the mirror throats. In this initial report period, primary and backup antennas were designed and fabricated. The primary pair was installed in the UTRC mirror facility and stabilization tests were initiated. In these initial tests rf power was applied to only one antenna at a time. Preliminary results indicate a stoppering effect at the mirror throat subjected to the rf and a simultaneous increase in the rate of decay of the confined plasma. These observations suggest the stoppering effect at one mirror throat is more than offset by an enhanced loss rate through the other throat. In the next test series rf power will be applied simultaneously in both mirror throats.

  17. Effects of SF$_{6}$ on the avalanche mode operation of a real-sized double-gap resistive plate chamber for the Compact Muon Solenoid experiment

    CERN Document Server

    Ahn Sung Hwan; Hong, B; Hong, S J; Ito, M; Kim, B I; Kim, J H; Kim, Y J; Kim, Y U; Koo, D G; Lee, H W; Lee, K B; Lee, K S; Lee, S J; Lim, J K; Moon, D H; Nam, S K; Park, S; Park, W J; Rhee, J T; Ryu, M S; Shim, H H; Sim, K S; Kang, T I

    2005-01-01

    We present the design and the test, results for a real-sized prototype resistive plate chamber by using cosmic-ray muons for the forward region of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). In particular, we investigate the effects of adding SF/sub 6/ to the gas mixture for the avalanche mode operation of a resistive plate chamber. A small fraction of SF/sub 6/ is very effective in suppressing streamer signals in a resistive plate chamber. The shapes of the muon detection efficiency and the muon cluster size remain similar, but are shifted to higher operating voltage by SF/sub 6/. The noise cluster rate and size are not influenced by SF/sub 6/.

  18. Transarticular fixation by hook plate versus coracoclavicular stabilization by single multistrand titanium cable for acute Rockwood grade-V acromioclavicular joint dislocation: a case-control study.

    Science.gov (United States)

    Gao, You-Shui; Zhang, Yue-Lei; Ai, Zi-Sheng; Sun, Yu-Qiang; Zhang, Chang-Qing; Zhang, Wei

    2015-11-19

    Hook plate (HP) is popularly used for acute and severely displaced acromioclavicular (AC) dislocations. However, subacromial impingement and acromion osteolysis induced by transarticular fixation are notorious. The current case-control study was to compare transarticular fixation by HP to coracoclavicular (CC) stabilization by single multistrand titanium cable (MSTC). Between January 2006 and August 2009, 24 patients with acute AC dislocations were surgically treated by open reduction and transarticular fixation with HP. These patients were matched to a series of 24 patients, who were managed by CC stabilization with MSTC in the same period. All AC dislocations were graded as Rockwood type V. Implant was removed 8-12 months after the primary operation in all patients, and 12 months at least were needed to assess the maintenance of AC joint. Functional results were evaluated before implant removal as well as in the last follow-up based on Constant-Murley criteria. There were no differences of demographic data including age, dominant gender and side, injury-to-surgery interval, operation time and follow-up period. In terms of functionality, Constant score was 95.8 ± 4.1 in MSTC group, while 76.7 ± 8.0 in HP group before implant removal (P acromioclavicular joint presented in 16 patients (66.7%) in patients treated by HP, while it was found in only 3 patients (12.5%) treated by MSTC (P acromioclavicular dislocation both before and after removal of the implant. Hardware removal is of great benefits for functional improvement in patients treated by HP.

  19. Influence of chronometry on hydrodynamic stability: design of Direct-Drive experiments

    Science.gov (United States)

    Laffite, Stephane; Canaud, Benoit; Masse, Laurent; Larroche, Olivier; Girard, Frederic; Tassin, Veronique; Philippe, Frank; Landoas, Olivier; Caillaud, Tony; CEA Team

    2013-10-01

    We present here the 2D design of future Direct-Drive (DD) experiments which will be carried out in 2014 at the OMEGA facility. Hydrodynamic stability of capsule is a major concern for DD and Indirect-Drive (ID) implosions. Stability can be greatly affected by the chronometry of the drive. The objective of these experiments is to study the impact of chronometry on the stability of the target. Target will be filled with 15 bars of DT or DD-Argon. Diameter will be about 900 microns. Plastic shell thickness will be 25 microns. Target dimensions will be the same for all the shots. Pulse will be varied from a square pulse to 2-steps-pulse and 3-steps-pulses. Hydrodynamic stability decreases with the number of steps: convergence ration increases from Rc = 14 to Rc = 20 whereas adiabat decreases from 3.5 to 1.7. For some shots, low-mode asymmetries will be created by turning off some of the beams.

  20. Instability of modes in a partially hinged rectangular plate

    Science.gov (United States)

    Ferreira, Vanderley; Gazzola, Filippo; Moreira dos Santos, Ederson

    2016-12-01

    We consider a thin and narrow rectangular plate where the two short edges are hinged whereas the two long edges are free. This plate aims to represent the deck of a bridge, either a footbridge or a suspension bridge. We study a nonlocal evolution equation modeling the deformation of the plate and we prove existence, uniqueness and asymptotic behavior for the solutions for all initial data in suitable functional spaces. Then we prove results on the stability/instability of simple modes motivated by a phenomenon which is visible in actual bridges and we complement these theorems with some numerical experiments.

  1. Two-Dimensional Mapping of the Calculated Fission Power for the Full-Size Fuel Plate Experiment Irradiated in the Advanced Test Reactor

    Science.gov (United States)

    Chang, G. S.; Lillo, M. A.

    2009-08-01

    The National Nuclear Security Administrations (NNSA) Reduced Enrichment for Research and Test Reactors (RERTR) program assigned to the Idaho National Laboratory (INL) the responsibility of developing and demonstrating high uranium density research reactor fuel forms to enable the use of low enriched uranium (LEU) in research and test reactors around the world. A series of full-size fuel plate experiments have been proposed for irradiation testing in the center flux trap (CFT) position of the Advanced Test Reactor (ATR). These full-size fuel plate tests are designated as the AFIP tests. The AFIP nominal fuel zone is rectangular in shape having a designed length of 21.5-in (54.61-cm), width of 1.6-in (4.064-cm), and uniform thickness of 0.014-in (0.03556-cm). This gives a nominal fuel zone volume of 0.482 in3 (7.89 cm3) per fuel plate. The AFIP test assembly has two test positions. Each test position is designed to hold 2 full-size plates, for a total of 4 full-size plates per test assembly. The AFIP test plates will be irradiated at a peak surface heat flux of about 350 W/cm2 and discharged at a peak U-235 burn-up of about 70 at.%. Based on limited irradiation testing of the monolithic (U-10Mo) fuel form, it is desirable to keep the peak fuel temperature below 250°C to achieve this, it will be necessary to keep plate heat fluxes below 500 W/cm2. Due to the heavy U-235 loading and a plate width of 1.6-in (4.064-cm), the neutron self-shielding will increase the local-to-average-ratio (L2AR) fission power near the sides of the fuel plates. To demonstrate that the AFIP experiment will meet the ATR safety requirements, a very detailed 2-dimensional (2D) Y-Z fission power profile was evaluated in order to best predict the fuel plate temperature distribution. The ability to accurately predict fuel plate power and burnup are essential to both the design of the AFIP tests as well as evaluation of the irradiated fuel performance. To support this need, a detailed MCNP Y

  2. Fusion Reactor and Break-Even Experiment Based on Stabilized Liner Compression of Plasma

    Science.gov (United States)

    Turchi, Peter; Frese, Sherry; Frese, Michael

    2016-10-01

    An optimum regime, known as magnetized-target or magneto-inertial fusion (MTF/MIF), requires magnetic fields at megagauss levels, which are attainable by use of dynamic conductors called liners. The stabilized liner compressor (SLC) provides the basis for controlled implosion and re-capture of the liner for reversible energy exchange between liner kinetic energy and the internal energy of a magnetized-plasma target. This exchange requires rotational stabilization of Rayleigh-Taylor modes on the inner surface of the liner and pneumatically driven free-pistons that eliminate such modes at the outer surface. We discuss the implications of the SLC approach for the power reactor, a breakeven experiment, and intermediate experiments to develop the plasma target. Features include the importance of pneumatic drive and the liner-blanket for economic feasibility of MTF/MIF. Supported by ARPA-E ALPHA Program.

  3. Stabilization

    Directory of Open Access Journals (Sweden)

    Muhammad H. Al-Malack

    2016-07-01

    Full Text Available Fuel oil flyash (FFA produced in power and water desalination plants firing crude oils in the Kingdom of Saudi Arabia is being disposed in landfills, which increases the burden on the environment, therefore, FFA utilization must be encouraged. In the current research, the effect of adding FFA on the engineering properties of two indigenous soils, namely sand and marl, was investigated. FFA was added at concentrations of 5%, 10% and 15% to both soils with and without the addition of Portland cement. Mixtures of the stabilized soils were thoroughly evaluated using compaction, California Bearing Ratio (CBR, unconfined compressive strength (USC and durability tests. Results of these tests indicated that stabilized sand mixtures could not attain the ACI strength requirements. However, marl was found to satisfy the ACI strength requirement when only 5% of FFA was added together with 5% of cement. When the FFA was increased to 10% and 15%, the mixture’s strength was found to decrease to values below the ACI requirements. Results of the Toxicity Characteristics Leaching Procedure (TCLP, which was performed on samples that passed the ACI requirements, indicated that FFA must be cautiously used in soil stabilization.

  4. Removal of surface layers from plated materials: upgrading of scrap

    NARCIS (Netherlands)

    Dapper, G.; Sloterdijk, W.; Verbraak, C.A.

    1978-01-01

    In this paper a description is given of a method developed for the purpose of removing surface layers from plated materials. The principle of separation is based on the difference in vapour pressures and stabilities with the formation of metal chlorides. A series of pyrolytic experiments was carried

  5. Repositioning and stabilization of the radial styloid process in comminuted fractures of the distal radius using a single approach: the radio-volar double plating technique

    OpenAIRE

    Jacobi Matthias; Wahl Peter; Kohut Georges

    2010-01-01

    Abstract Background A possible difficulty in intra-articular fracture of the distal radius is the displacement tendency of the radial styloid process due to the tension of the brachioradialis tendon. Methods Ten patients treated within one year for complex distal radius fractures by double-plating technique with a radial buttress plate and volar locking plate, through a single volar approach, were followed prospectively during 24 months. Outcome measures included radiographic follow-up, range...

  6. OUR EXPERIENCE WITH MAGERL’S MODIFIED TECHNIQUE FOR STABILIZATION OF SUBAXIAL CERVICAL SPINE

    Directory of Open Access Journals (Sweden)

    Haritonov Dimitar

    2015-03-01

    Full Text Available Aim: There are different surgical techniques for massa lateralis screw instrumentation of subaxial cervical spine--those of Roy-Camille, Magerl, Anderson, and An. Each has different starting point and trajectorys of screw implantation.For each technique there is a potential risk to affect vascular and neural structures.In this paper we share our experience in using a modified Magerl's technique for stabilization of subaxial cervical spine. Method:We present a retrospective study and clinical follow-up of 27 patients operated on the occasion of cervical injury that we have used the modified technique of Magerl. In 8 patients was carried and an anterior decompression and stabilization. Results: In these patients was carried posterior or combined -- posterior and anterior stabilization. The posterior fixation was massa lateralis with this modified technique of Magerl with multiaxial screws. With this technique were inserted 160 multiaxial screws and the most common length of the implants were 108 mm (108 from 160 or 67.5%. Conclusion: Based on world literature, experience and analysis of clinical cases, we believe that this modified technique for subaxial cervical fixation is effective (the pull-out strength approach to the strength of pedicle screw instrumentation and is much safer.

  7. 3D COMSOL Simulations for Thermal Deflection of HFIR Fuel Plate in the "Cheverton-Kelley" Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Prashant K [ORNL; Freels, James D [ORNL; Cook, David Howard [ORNL

    2012-08-01

    Three dimensional simulation capabilities are currently being developed at Oak Ridge National Laboratory using COMSOL Multiphysics, a finite element modeling software, to investigate thermal expansion of High Flux Isotope Reactor (HFIR) s low enriched uranium fuel plates. To validate simulations, 3D models have also been developed for the experimental setup used by Cheverton and Kelley in 1968 to investigate the buckling and thermal deflections of HFIR s highly enriched uranium fuel plates. Results for several simulations are presented in this report, and comparisons with the experimental data are provided when data are available. A close agreement between the simulation results and experimental findings demonstrates that the COMSOL simulations are able to capture the thermal expansion physics accurately and that COMSOL could be deployed as a predictive tool for more advanced computations at realistic HFIR conditions to study temperature-induced fuel plate deflection behavior.

  8. Casimir force between metal plate and dielectric plate

    Institute of Scientific and Technical Information of China (English)

    刘中柱; 邵成刚; 罗俊

    1999-01-01

    The Casimir effect between metal plate and dielectric plate is discussed with 1+1-dimensional potential model without using cut-off method. Calculation shows that the Casimir force between metal plate and dielectric plate is determined not only by the potential V0, the dielectric thickness and the distance α between the metal plate and dielectric plate, but also by the dimension of the vessel. When α is far less than the dimension of the vessel, the Casimir force Fc∝α(-1); conversely Fc∝α-2. This result is significant for Casimir force experiment.

  9. Generation of Accelerated Stability Experiment Profile of Inertial Platform Based on Finite Element

    Institute of Scientific and Technical Information of China (English)

    CHEN Yunxia; HUANG Xiaokai; KANG Rui

    2012-01-01

    The residual stress generated in the manufacturing process of inertial platform causes the drift of inertial platform parameters in long-term storage condition.However,the existing temperature cycling experiment could not meet the increased repeatability technical requirements of inertial platform parameters.In order to solve this problem,in this paper,firstly the Unigraphics (UG) software and the interface compatibility of ANSYS software are used to establish the inertial platform finite element model.Secondly,the residual stress is loaded into finite element model by ANSYS function editor in the form of surface loads to analyze the efficiency.And then,the generation based on ANSYS simulation inertial platform to accelerate the stability of experiment profile is achieved by the application of the analysis method of orthogonal experimental design and ANSYS thermal-structural coupling.The optimum accelerated stability experiment profile is determined finally,which realizes the rapid,effective release of inertial platform residual stress.The research methodology and conclusion of this paper have great theoretical and practical significance to the production technology of inertial platform.

  10. Experiments of Laser Pointing Stability in Air and in Vacuum to Validate Micrometric Positioning Sensor

    CERN Document Server

    Stern, G; Piedigrossi, D; Sandomierski, J; Sosin, M; Geiger, A; Guillaume, S

    2014-01-01

    Aligning accelerator components over 200m with 10 μm accuracy is a challenging task within the Compact Linear Collider (CLIC) study. A solution based on laser beam in vacuum as straight line reference is proposed. The positions of the accelerator’s components are measured with respect to the laser beam by sensors made of camera/shutter assemblies. To validate these sensors, laser pointing stability has to be studied over 200m. We perform experiments in air and in vacuum in order to know how laser pointing stability varies with the distance of propagation and with the environment. The experiments show that the standard deviations of the laser spot coordinates increase with the distance of propagation. They also show that the standard deviations are much smaller in vacuum (8 μm at 35m) than in air (2000 μm at 200m). Our experiment validates the concept of laser beam in vacuum with camera/shutter assembly for micrometric positioning over 35m. It also gives an estimation of the achievable precision.

  11. Outcome of proximal humerus fractures treated by PHILOS plate internal fixation. Experience of a district general hospital.

    Science.gov (United States)

    Shahid, Rizwan; Mushtaq, Abid; Northover, Julian; Maqsood, Mohammad

    2008-10-01

    Proximal humerus fractures have been a challenge to achieve stable fixation. PHILOS (Proximal Humerus internal locking system) is part of the latest generation of locking compression plates for proximal humeral fracture fixation. We aim to assess the clinical and functional outcome of proximal humeral fractures (2-part, 3-part and 4-part) treated with the PHILOS plate. We prospectively reviewed 50 patients who had a proximal humeral fracture treated with the PHILOS plate from September 2002 to September 2006 in our institution. Clinical outcome was measured using the patient-based Oxford shoulder and DASH scoring systems. Five patients died and four were lost to follow-up. Eleven patients had 2-part, eleven 3-part and eighteen 4-part fractures. Mean follow-up time was 21.7 months (range: 6-44 months). Radiological union was achieved within 8 weeks in 40/41 fractures; complications were noted in four cases. Better results were achieved in younger than in older patients, and in male than in female patients. The number of fracture fragments did not appear to affect the results, but associated dislocation of the humeral head was a pejorative factor. Our study has shown that the PHILOS plate is a reliable implant. A direct correlation was observed between Oxford shoulder and DASH scores.

  12. The experiments of Ramón M. Termeyer SJ on the electric eel in the River Plate region (c. 1760) and other early accounts of Electrophorus electricus.

    Science.gov (United States)

    de Asúa, Miguel

    2008-01-01

    This paper focuses on Ramón M. Termeyer SJ (1737-1814?), a naturalist who experimented with the electric eel in the River Plate region during the 1760s. After going through an enumeration of the chroniclers that since the sixteenth century noticed the benumbing discharge of Electrophorus electricus, the article summarizes the work that immediately preceded Termeyer's and considers as a term of comparison the experiments on the electric eel performed by Bertrand Bajon (fl. 1751-1778) in the French Guyanne. It ends by discussing the meaning of Termeyer's 1781 and 1810 articles in the light of contemporary ideas of animal electricity.

  13. [Experience with Poly Ether Ether Ketone (PEEK) cages and locking plate for anterior cervical fusion in the treatment of spine trauma without cord injury].

    Science.gov (United States)

    Delépine, F; Jund, S; Schlatterer, B; de Peretti, F

    2007-12-01

    The purpose of this study was to determine whether spinal fusion using radiotransparent cages can be an appropriate treatment for traumatic injury of the cervical spine. This series included 30 patients aged 17-84 years (average 46 years) treated between October 1999 and June 2003 for traumatic injury of the cervical spine without neurological deficit or cord injury. There were two bifocal cases so that the study concerned 32 fusions. Injuries were: tear drop (n=1), serious flexion sprain (n=8), biarticular dislocation (n=4), serous hyperextension sprain (n=4), dislocation-fracture (n=1), uniarticular fracture (n=7), fracture-separation of the facet joints (n=4), post-traumatic herniation (n=3). For each injury, we measured pre and postoperatively and at last follow-up: the intersomatic angle, anterior displacement, and height of the intersomatic space at the center of the intervertebral disc. All x-rays were read twice, by two independent investigators. In the event of disagreement, the x-rays were read again by a senior surgeon and the main author of this article. Anterior fusion was achieved using a Poly Ether Ether Ketone (PEEK) (32%) and knitted carbon (68%) cage (cologne, Ostapek, Nexis) filled with cancellous bone harvested percutaneously from the iliac crest. The cage was associated with an anterior titanium plate fixation (Senegas, Euros and Orion, Medtronic). A posterior approach was associated if further stability was required (n=4 fusions). All patients were reviewed at minimum five months follow-up. Intersomatic fusion was verified on the standard x-rays (plus stress images and computed tomography at three months). Fusion was considered to be achieved if continuous bone lines crossed the graft and angle measurements remained stable, with the cage in the same position on successive examinations. One patient died from lung cancer five months after spinal fusion. All other patients survived with a mean follow-up of 24 months. Fusion was achieved in all

  14. Stability

    Directory of Open Access Journals (Sweden)

    Nada S. Abdelwahab

    2017-05-01

    Full Text Available The present work concerns with the development of stability indicating the RP-HPLC method for simultaneous determination of guaifenesin (GUF and pseudoephedrine hydrochloride (PSH in the presence of guaifenesin related substance (Guaiacol. GUC, and in the presence of syrup excepients with minimum sample pre-treatment. In the developed RP-HPLC method efficient chromatographic separation was achieved for GUF, PSH, GUC and syrup excepients using ODS column as a stationary phase and methanol: water (50:50, v/v, pH = 4 with orthophosphoric acid as a mobile phase with a flow rate of 1 mL min−1 and UV detection at 210 nm. The chromatographic run time was approximately 10 min. Calibration curves were drawn relating the integrated area under peak to the corresponding concentrations of PSH, GUF and GUC in the range of 1–8, 1–20, 0.4–8 μg mL−1, respectively. The developed method has been validated and met the requirements delineated by ICH guidelines with respect to linearity, accuracy, precision, specificity and robustness. The validated method was successfully applied for determination of the studied drugs in triaminic chest congestion® syrup; moreover its results were statistically compared with those obtained by the official method and no significant difference was found between them.

  15. A large-scale forest fragmentation experiment: the Stability of Altered Forest Ecosystems Project.

    Science.gov (United States)

    Ewers, Robert M; Didham, Raphael K; Fahrig, Lenore; Ferraz, Gonçalo; Hector, Andy; Holt, Robert D; Kapos, Valerie; Reynolds, Glen; Sinun, Waidi; Snaddon, Jake L; Turner, Edgar C

    2011-11-27

    Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity to reveal the complex processes that operate within natural ecosystems. Here, we review the design of existing, large-scale forest fragmentation experiments. Based on this review, we develop a design for the Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experiment to be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project represents an advance on existing experiments in that it: (i) allows discrimination of the effects of landscape-level forest cover from patch-level processes; (ii) is designed to facilitate the unification of a wide range of data types on ecological patterns and processes that operate over a wide range of spatial scales; (iii) has greater replication than existing experiments; (iv) incorporates an experimental manipulation of riparian corridors; and (v) embeds the experimentally fragmented landscape within a wider gradient of land-use intensity than do existing projects. The SAFE Project represents an opportunity for ecologists across disciplines to participate in a large initiative designed to generate a broad understanding of the ecological impacts of tropical forest modification.

  16. Is there Complex Trauma Experience typology for Australian's experiencing extreme social disadvantage and low housing stability?

    Science.gov (United States)

    Keane, Carol A; Magee, Christopher A; Kelly, Peter J

    2016-11-01

    Traumatic childhood experiences predict many adverse outcomes in adulthood including Complex-PTSD. Understanding complex trauma within socially disadvantaged populations has important implications for policy development and intervention implementation. This paper examined the nature of complex trauma experienced by disadvantaged individuals using a latent class analysis (LCA) approach. Data were collected through the large-scale Journeys Home Study (N=1682), utilising a representative sample of individuals experiencing low housing stability. Data on adverse childhood experiences, adulthood interpersonal trauma and relevant covariates were collected through interviews at baseline (Wave 1). Latent class analysis (LCA) was conducted to identify distinct classes of childhood trauma history, which included physical assault, neglect, and sexual abuse. Multinomial logistic regression investigated childhood relevant factors associated with class membership such as biological relationship of primary carer at age 14 years and number of times in foster care. Of the total sample (N=1682), 99% reported traumatic adverse childhood experiences. The most common included witnessing of violence, threat/experience of physical abuse, and sexual assault. LCA identified six distinct childhood trauma history classes including high violence and multiple traumas. Significant covariate differences between classes included: gender, biological relationship of primary carer at age 14 years, and time in foster care. Identification of six distinct childhood trauma history profiles suggests there might be unique treatment implications for individuals living in extreme social disadvantage. Further research is required to examine the relationship between these classes of experience, consequent impact on adulthood engagement, and future transitions though homelessness.

  17. Experiment of Laser Pointing Stability on Different Surfaces to validate Micrometric Positioning Sensor

    CERN Document Server

    AUTHOR|(SzGeCERN)721924; Mainaud Durand, Helene; Piedigrossi, Didier; Sandomierski, Jacek; Sosin, Mateusz; Geiger, Alain; Guillaume, Sebastien

    2014-01-01

    CLIC requires 10 μm precision and accuracy over 200m for the pre-alignment of beam related components. A solution based on laser beam as straight line reference is being studied at CERN. It involves camera/shutter assemblies as micrometric positioning sensors. To validate the sensors, it is necessary to determine an appropriate material for the shutter in terms of laser pointing stability. Experiments are carried out with paper, metal and ceramic surfaces. This paper presents the standard deviations of the laser spot coordinates obtained on the different surfaces, as well as the measurement error. Our experiments validate the choice of paper and ceramic for the shutter of the micrometric positioning sensor. It also provides an estimate of the achievable precision and accuracy of the determination of the laser spot centre with respect to the shutter coordinate system defined by reference targets.

  18. Control and stabilization: making Millikan's oil drop experiment work

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Hill, Christoph [Physics Education/History and Philosophy of Science, Institute of Physics, Carl-von-Ossietzky Universitaet, 26111 Oldenburg (Germany); Heering, Peter, E-mail: christoph.mueller.hill@mail.uni-oldenburg.de, E-mail: peter.heering@uni-flensburg.de [Institut fuer Physik und Chemie und ihre Didaktik, Universitaet Flensburg, 27356 Flensburg (Germany)

    2011-09-15

    Educational versions of Millikan's oil-drop experiment have frequently been criticized; suggestions for improvement either focus on technical innovations of the setup or on replacing the experiment by other approaches of familiarization, such as computer simulations. In our approach, we have analysed experimental procedures. In doing so, we were able to identify several sources of error and took measures to minimize their influence. At the same time, we attempted to minimize the standard deviation of each individual series of measurements. Our paper describes how we developed criteria which helped to stabilize the data produced in the following series of measurements. The final series of measurements results in data which demonstrate the atomic structure of electricity and enable a demonstration of the elementary charge.

  19. [First experiments for the detection of simulated mammographic lesions: digital full field mammography with a new detector with a double plate of pure selenium].

    Science.gov (United States)

    Schulz-Wendtland, R; Hermann, K-P; Wenkel, E; Adamietz, B; Lell, M; Anders, K; Uder, M

    2011-02-01

    The article describes an experimental phantom study of a system for digital full field mammography with a new digital detector with a double plate of pure selenium. The experiments were carried out with the new full field digital mammography system Amulet from FujiFilm. This system has a new detector (18×24 cm(2)) on the basis of highly purified amorphous selenium (a-Se) with a pixel size of 50 µm. The x-rays are converted into electric signals in the first plate which are read into the second plate with the help of an optical switch and demonstrated in the form of an image. In this way a better pixel size/volume and signal-to-noise ratio should be achieved. The object of the investigation was the Wisconsin Mammographic Random Phantom, Model 152 A (Technical Performance Mo/Mo, 28 kV, 100 mAs). Five investigators with different experiences in mammography each received three images on a monitor with different random positions of the simulated lesions in the phantom for assessment. The detection rates were compared under the same conditions with the results of two other full field digital mammography systems. The median detection rate for all images and investigators for the new doubled plated a-Se detector with optical switch was 98.7%. For both other systems with a-Si or and a-Se detectors the detection rate was 89.8% or 97.3%, respectively. There were no significant differences in the detection rate of the simulated breast lesions for all three systems considering the interobserver and intraobserver variation. The first phantom study for the detection of simulated breast lesions with the new full field digital mammography system Amulet demonstrates equivalent results with the other systems used in the clinical routine. The trend towards superiority of the new system has to be confirmed in further clinical studies.

  20. Analysis of Pilot-Induced-Oscillation and Pilot Vehicle System Stability Using UAS Flight Experiments

    Directory of Open Access Journals (Sweden)

    Tanmay K. Mandal

    2016-11-01

    Full Text Available This paper reports the results of a Pilot-Induced Oscillation (PIO and human pilot control characterization study performed using flight data collected with a Remotely Controlled (R/C unmanned research aircraft. The study was carried out on the longitudinal axis of the aircraft. Several existing Category 1 and Category 2 PIO criteria developed for manned aircraft are first surveyed and their effectiveness for predicting the PIO susceptibility for the R/C unmanned aircraft is evaluated using several flight experiments. It was found that the Bandwidth/Pitch rate overshoot and open loop onset point (OLOP criteria prediction results matched flight test observations. However, other criteria failed to provide accurate prediction results. To further characterize the human pilot control behavior during these experiments, a quasi-linear pilot model is used. The parameters of the pilot model estimated using data obtained from flight tests are then used to obtain information about the stability of the Pilot Vehicle System (PVS for Category 1 PIOs occurred during straight and level flights. The batch estimation technique used to estimate the parameters of the quasi-linear pilot model failed to completely capture the compatibility nature of the human pilot. The estimation results however provided valuable insights into the frequency characteristics of the human pilot commands. Additionally, stability analysis of the Category 2 PIOs for elevator actuator rate limiting is carried out using simulations and the results are compared with actual flight results.

  1. Nonlinear stability of cylindrical shells subjected to axial flow: Theory and experiments

    Science.gov (United States)

    Karagiozis, K. N.; Païdoussis, M. P.; Amabili, M.; Misra, A. K.

    2008-01-01

    This paper, is concerned with the nonlinear dynamics and stability of thin circular cylindrical shells clamped at both ends and subjected to axial fluid flow. In particular, it describes the development of a nonlinear theoretical model and presents theoretical results displaying the nonlinear behaviour of the clamped shell subjected to flowing fluid. The theoretical model employs the Donnell nonlinear shallow shell equations to describe the geometrically nonlinear structure. The clamped beam eigenfunctions are used to describe the axial variations of the shell deformation, automatically satisfying the boundary conditions and the circumferential continuity condition exactly. The fluid is assumed to be incompressible and inviscid, and the fluid-structure interaction is described by linear potential flow theory. The partial differential equation of motion is discretized using the Galerkin method and the final set of ordinary differential equations are integrated numerically using a pseudo-arclength continuation and collocation techniques and the Gear backward differentiation formula. A theoretical model for shells with simply supported ends is presented as well. Experiments are also described for (i) elastomer shells subjected to annular (external) air-flow and (ii) aluminium and plastic shells with internal water flow. The experimental results along with the theoretical ones indicate loss of stability by divergence with a subcritical nonlinear behaviour. Finally, theory and experiments are compared, showing good qualitative and reasonable quantitative agreement.

  2. The relationship between stabilizer and copper deposition rate in the electroless copper plating solution%化学镀铜溶液中稳定剂与铜沉积速率的关系

    Institute of Scientific and Technical Information of China (English)

    秦建芳; 姚陈忠; 孙鸿

    2012-01-01

    It was researched for stabilizer on the copper deposition rate in the electroless copper plating solution. It was fully consider for main complexing agent, side effects of inhibitors and formaldehyde capture agent which concentration of electroless copper plating. The base formula as copper sulfate 3 g/L, formaldehyde 8 g/L, ethylenediamine tetraacetic acid 28 g/L, sodium hydroxide 7.5 g/L, the process parameters were temperature being 50℃, the pH value being 12.5 and plating time being 40 min. The a-mount of the three types of stabilizers were determined for methanol 8 mg/L, potassium ferrocyanide 6 mg/L bipyridyl. The coating obtained under the optimal technical conditions was Hongliang appearance, surface roughness, grain size and detailed electroless copper plating solution stability.%研究了化学镀铜溶液中稳定剂对铜沉积速率的影响,着重考虑主配位剂、副反应的抑制剂、甲醛捕获剂对化学镀铜的影响.结果表明,在基本配方8 g/L CuSO4·5H2O,3 g/L HCHO,28 g/L EDTA,7.5 g/L NaOH,工艺参数pH=12.5,温度50℃,时间40 min的基础上,各种稳定剂的适宜用量为6 mL/L CH3OH、8 mg/L K4Fe(CN)6、6 mg/L2,2’-bipy.在最佳工艺下得到的镀层外观红亮,表面平整,晶粒细致,化学镀铜液稳定.

  3. Oscillatory thermocapillary convection in liquid bridges with highly deformed free surfaces: Experiments and energy-stability analysis

    Science.gov (United States)

    Sumner, L. B. S.; Neitzel, G. P.; Fontaine, J.-P.; Dell'Aversana, P.

    2001-01-01

    Laboratory experimentation, numerical simulation, and energy-stability theory are used to examine the effect of interface deformation on the onset of oscillatory thermocapillary convection in half zones. Experiments are performed to map the stability boundaries marking the onset of oscillatory flow, modifying the free-surface deformation by adjusting the volume of liquid in the bridge. The stability results presented here along with those of other researchers [Monti et al., Proceedings of the 43rd Cong. Int. Artro. Fed. (1992); Hu et al., J. Cryst. Growth 142, 379 (1994)] show that free-surface curvature can have a pronounced influence on flow stability. Steady, axisymmetric flow simulations are computed using the commercial code FIDAP to model the conditions of the experiments, and reveal that flow structure near the stability boundary is sensitive to several parameters. Energy theory is applied to these simulations to determine sufficient conditions for stability. Comparisons between the theoretical and experimental results show nonconservative energy limits falling above the experimentally determined stability boundaries for bridges of various liquid volumes. While the trend of the experimental data is predicted for zones of large volume ratio (bulging zones), the same cannot be said for those with small volume ratio (necked-down zones). In addition, energy-stability limits for some undeformed-free-surface cases were determined which are above the linear-stability limits determined by other researchers, in clear contradiction of the roles of the respective theories.

  4. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wanne, Toivo; Johansson, Erik; Potyondy, David [Saanio and Riekkola Oy, Helsinki (Finland)

    2004-02-01

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  5. Experiments of dike-induced deformation: Insights on the long-term evolution of divergent plate boundaries

    KAUST Repository

    Trippanera, D.

    2015-10-22

    The shallow transport of magma occurs through dikes causing surface deformation. Our understanding of the effects of diking at the surface is limited, especially on the long term, for repeated intrusive episodes. We use analogue models to study the upper crustal deformation induced by dikes. We insert metal plates within cohesive sand with three setups: in setup A, the intrusion rises upward with constant thickness and in setups B and C, the intrusion thickens at a fixed depth, with final rectangular (setup B) or triangular (setup C) shape in section. Setup A creates a doming delimited by reverse faults, with secondary apical graben, without close correspondence in nature. In setups B and C, a depression flanked by two uplifted areas is bordered by inward dipping normal faults propagating downward and, for deeper intrusions in setup B, also by inner faults, reverse at the surface; this deformation is similar to what is observed in nature, suggesting a consistent physical behavior. Dikes in nature initially propagate developing a mode I fracture at the tip, subsequently thickened by magma intrusion, without any host rock translation in the propagation direction (as in setup A). The deformation pattern in setups B and C depends on the intrusion depth and thickness, consistently to what is observed along divergent plate boundaries. The early deformation in setups B and C is similar to that from a single rifting episode (i.e., Lakagigar, Iceland, and Dabbahu, Afar), whereas the late stages resemble the structure of mature rifts (i.e., Krafla, Iceland), confirming diking as a major process in shaping divergent plate boundaries.

  6. The role of fluid pressure in frictional stability and earthquake triggering: insights from laboratory experiments

    Science.gov (United States)

    Collettini, Cristiano; Scuderi, Marco

    2015-04-01

    Fluid overpressure has been proposed as one of the primary mechanisms that facilitate earthquake slip along faults. However, elastic dislocation theory combined with friction laws suggests that fluid overpressure may inhibit the dynamic instabilities that result in earthquakes, by controlling the critical fault stiffness (kc). This controversy poses a serious problem in our understanding of earthquake physics, with severe implications for both natural and human-induced seismic hazard. Nevertheless, currently, there are no systematic studies on the role of fluid pressure under controlled, laboratory conditions for which the evolution of friction parameters and slip stability can be measured. We have used a state-of-the-art biaxial rock deformation apparatus within a pressure vessel, in order to allow a true triaxial stress field, in a double direct shear configuration. We tested carbonate fault gouge, Carrara marble, sieved to a grain size of 125 μm. Normal stresses and confining pressure were held constant throughout the experiment at values of 5 to 40 MPa, and the pore fluid pressure was varied from hydrostatic up to near lithostatic values. Shear stress was induced by a constant displacement rate and sliding velocities varied from 0.1-1000 μm/s, in order to evaluate slip stability via rate- and state- dependent frictional parameters, such as (a-b), Dc and kc. Our data show that sliding velocity controls the values of friction parameters. In addition we observe a general increase of (a-b) and a decrease of Dc with increasing fluid pressure. Our observations suggest that fluid overpressure does not only facilitate fault reactivation but it also influences frictional parameters with important implications for fault stability and earthquake triggering.

  7. Stabilization of electron-scale turbulence by electron density gradient in national spherical torus experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Ruiz, J.; White, A. E. [MIT-Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Ren, Y.; Guttenfelder, W.; Kaye, S. M.; Leblanc, B. P.; Mazzucato, E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lee, K. C. [National Fusion Research Institute, Daejeon (Korea, Republic of); Domier, C. W. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

    2015-12-15

    Theory and experiments have shown that electron temperature gradient (ETG) turbulence on the electron gyro-scale, k{sub ⊥}ρ{sub e} ≲ 1, can be responsible for anomalous electron thermal transport in NSTX. Electron scale (high-k) turbulence is diagnosed in NSTX with a high-k microwave scattering system [D. R. Smith et al., Rev. Sci. Instrum. 79, 123501 (2008)]. Here we report on stabilization effects of the electron density gradient on electron-scale density fluctuations in a set of neutral beam injection heated H-mode plasmas. We found that the absence of high-k density fluctuations from measurements is correlated with large equilibrium density gradient, which is shown to be consistent with linear stabilization of ETG modes due to the density gradient using the analytical ETG linear threshold in F. Jenko et al. [Phys. Plasmas 8, 4096 (2001)] and linear gyrokinetic simulations with GS2 [M. Kotschenreuther et al., Comput. Phys. Commun. 88, 128 (1995)]. We also found that the observed power of electron-scale turbulence (when it exists) is anti-correlated with the equilibrium density gradient, suggesting density gradient as a nonlinear stabilizing mechanism. Higher density gradients give rise to lower values of the plasma frame frequency, calculated based on the Doppler shift of the measured density fluctuations. Linear gyrokinetic simulations show that higher values of the electron density gradient reduce the value of the real frequency, in agreement with experimental observation. Nonlinear electron-scale gyrokinetic simulations show that high electron density gradient reduces electron heat flux and stiffness, and increases the ETG nonlinear threshold, consistent with experimental observations.

  8. A numerical experiment on the equilibrium and stability of a rotating galactic bar

    Science.gov (United States)

    Miller, R. H.; Vandervoort, P. O.; Welty, D. E.; Smith, B. F.

    1982-01-01

    A self-consistent, three-dimensional numerical experiment is performed on an N-body system whose initial state is a realization of a certain theoretical model of a rotating triaxial galaxy. The model is a stellar-dynamical counterpart of a uniformly rotating polytrope of index equal to 0.5. The aim of the experiment is to study the equilibrium of the system and, in particular, to test its stability. The experimental system behaves in the mean like a realization of the theoretical model for at least seven crossing times. The principal departure of the system from equilibrium is an oscillation which is identified as a radial pulsation. There is no indication in its behavior that the system is unstable with respect to anu mode with an e-folding time shorter than or of the order of two crossing times. Certain changes that occur in the state of the system are interpreted, with the aid of the theoretical model, as secular changes which result from a slight failure of our numerical methods to conserve the mass, energy, and angular momentum of the system; these effects are small enough that they do not vitiate the experiment on a dynamical time scale.

  9. Plasma stabilization experiment. Final report, 1 October 1979-30 April 1980

    Energy Technology Data Exchange (ETDEWEB)

    Sziklas, E. A.; Fader, W. J.; Jong, R. A.; Stufflebeam, J. H.

    1980-07-01

    The Plasma Stabilization Experiment is an effort to enhance stability in a mirror-confined plasma by trapping cold ions with rf fields applied near the mirror throats. Nagoya Type III antennas, coupled to a 60 kW rf power supply are mounted in the throats of the UTRC baseball magnet. An external washer gun provides a source of plasma for both streaming and confined plasma tests. Results show a strong stoppering effect on streaming plasmas and a marginal effect on confined plasmas. Theoretical calculations provide an explanation for the experimental observations. The field generates a ponderomotive force acting on the electrons. The resultant improvement in electron confinement changes the ambipolar potential and inhibits the flow of ions through the mirror throat. Criteria are derived for the validity of this trapping concept. The requisite field strengths are significantly lower than those required to trap ions directly. Scaling laws are developed for application of cold ion trapping to large mirror devices containing dense plasmas. The use of slow-wave antenna structures operated at frequencies above the lower hybrid frequency is recommended for these applications.

  10. THELMA code electromagnetic model of ITER superconducting cables and application to the ENEA stability experiment

    Science.gov (United States)

    Ciotti, M.; Nijhuis, A.; Ribani, P. L.; Savoldi Richard, L.; Zanino, R.

    2006-10-01

    The new THELMA code, including a thermal-hydraulic (TH) and an electro-magnetic (EM) model of a cable-in-conduit conductor (CICC), has been developed. The TH model is at this stage relatively conventional, with two fluid components (He flowing in the annular cable region and He flowing in the central channel) being particular to the CICC of the International Thermonuclear Experimental Reactor (ITER), and two solid components (superconducting strands and jacket/conduit). In contrast, the EM model is novel and will be presented here in full detail. The results obtained from this first version of the code are compared with experimental results from pulsed tests of the ENEA stability experiment (ESE), showing good agreement between computed and measured deposited energy and subsequent temperature increase.

  11. [The first experience in using the stabilized hyaluronic acid preparation to correct lagophthalmos].

    Science.gov (United States)

    Grusha, Ia O; Ismailova, D S; Ivanchenko, Iu F; Agafonova, E I

    2010-01-01

    The authors report the results of the first experience in using the stabilized hyaluronic acid preparation in patients with lagopthalmos in the presence of facial nerve palsy and thyroid eye disease and resultant keratopathy of varying degrees. The study included 21 patients, including 15 patients with facial nerve palsy and 6 with endocrine ophthalmopathy. The gel was injected externally to the levator aponeurosis and/or intramuscular, and/or under the pretarsal portion of the orbicularis oculi muscle, and/or subcutaneously. The use of this method led to a significant reduction of lagophthalmos and to a considerable corneal improvement. That of this procedure permitted avoidance of surgical intervention in some patients. The mean follow-up period after injection was 11.2 months (range 6-24 months).

  12. Static stability analysis of smart magneto-electro-elastic heterogeneous nanoplates embedded in an elastic medium based on a four-variable refined plate theory

    Science.gov (United States)

    Ebrahimi, Farzad; Barati, Mohammad Reza

    2016-10-01

    In this article, a nonlocal four-variable refined plate theory is developed to examine the buckling behavior of nanoplates made of magneto-electro-elastic functionally graded (MEE-FG) materials resting on Winkler-Pasternak foundation. Material properties of nanoplate change in spatial coordinate based on power-law distribution. The nonlocal governing equations are deduced by employing the Hamilton principle. For various boundary conditions, the analytical solutions of nonlocal MEE-FG plates for buckling problem will be obtained based on an exact solution approach. Finally, dependency of buckling response of MEE-FG nanoplate on elastic foundation parameters, magnetic potential, external electric voltage, various boundary conditions, small scale parameter, power-law index, plate side-to-thickness ratio and aspect ratio will be figure out. These results can be advantageous for the mechanical analysis and design of intelligent nanoscale structures constructed from magneto-electro-thermo-elastic functionally graded materials.

  13. Less Invasive Stabilization System with Steel Plate Treating Comminuted Fracture of Proximal Tibia%微创内固定系统钢板治疗胫骨近端粉碎性骨折

    Institute of Scientific and Technical Information of China (English)

    吴善瑜

    2013-01-01

    Objective:To explore the methods and clinical effects of less invasive stabilization system with steel plate treating comminuted fracture of proximal tibia. Methods:In our hospital, 4 cases of proximal tibial comminuted fracture were treated with steel plate of less invasive stabilization sys-tem. Results:4 cases were all primary healing, with the excellent rate of 100%. Growing callus of postoperative 4 weeks, knee joint was able to with-stand force, and its function was normal, with normal gait without pain, tibia without angular deformity, cripetura less than 5mm and rotation less than 5 °. Conclusions:Less invasive stabilization system with steel plate is an effective method for treating comminuted fracture of proximal tibia, lit-tle trauma and less complications.%  目的:探讨微创内固定系统钢板治疗胫骨近端粉碎性骨折的方法和临床效果。方法:我院4例胫骨近端粉碎性骨折患者使用微创内固定系统钢板治疗。结果:4例伤口均一期愈合,优良率为100%。术后4周出现骨痂,膝关节功能正常并能对抗力量,步态正常无疼痛,胫骨无成角畸形、短缩<5mm、旋转<5°。结论:微创固定内系统钢板创伤小,并发症少,是治疗胫骨近端粉碎性骨折的有效方法。

  14. Flat plate collector with external reflectors (RefleC). Experiences withthe development; Flachkollektor mit externen Reflektoren (RefleC). Entwicklungserfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Hess, S.; Oliva, A.; Di Lauro, P.; Klemke, M.; Hermann, M.; Stryi-Hipp, G. [Fraunhofer-Institut fuer Solare Energiesysteme ISE, Freiburg (Germany); Kallwellis, V.; Kramp, G.; Eisenmann, W. [Wagner und Co. Solartechnik GmbH, Coelbe (Germany); Hanby, V. [DMU Leicester (United Kingdom). Inst. of Energy and Sustainable Development

    2010-07-01

    In cooperation with the Fraunhofer Institute for Solar Energy Systems (Freiburg, Federal Republic of Germany), the company Wagner and Co. Solar Technology (Coelbe, Federal Republic of Germany) developed a stationary concentrated, double-covered flat plate collector with an external reflector for generating process heat up to a temperature of 150 C. This prototype has a half-CPC reflector which is approximated by three flat segments. The reflectors use the distance between the collectors and serves simultaneously as a supporting structure. The collector is designed so that the aperture is not shaded. The authors of the contribution under consideration present the WKI curves and the IAM curves as a test pattern as well as a simulation of the annual energy yield. According to the simulation, the Reflec-collector has an annual energy yield which is greater by 64 % than that of the double-covered base-collector.

  15. Automatic genomics: a user-friendly program for the automatic designing and plate loading of medium-throughput qPCR experiments.

    Science.gov (United States)

    Callejas, Sergio; Alvarez, Rebeca; Dopazo, Ana

    2011-01-01

    Quantitative PCR (qPCR) remains the method of choice for gene and microRNA (miRNA) expression studies. Many laboratories wish to automate some or all of the steps of medium-throughput qPCR experiments through the use of various types of liquid handling robots. However, it is not uncommon to find cases in which scripts provided by the robot supplier are too rigid for user-specific applications, do not include all the desired options, or are too complicated to be modified by a nonprofessional programmer. Here, we present Automatic Genomics, a program that allows users with a limited programming background to automate medium-throughput qPCR experiments by using commercially available liquid-handling robots. The user is able to optimize the plate design in terms of number of genes, number of samples, and controls.

  16. On the tree stability risk

    Science.gov (United States)

    Giambastiani, Yamuna; Preti, Federico; Errico, Alessandro; Penna, Daniele

    2017-04-01

    There is growing interest in developing models for predicting how root anchorage and tree bracing could influence tree stability. This work presents the results of different experiments aimed at evaluating the mechanical response of plate roots to pulling tests. Pulling tests have been executed with increasing soil water content and soil of different texture. Different types of tree bracing have been examined for evaluating its impact on plant stiffness. Root plate was anchored with different systems for evaluating the change in overturning resistance. The first results indicate that soil water content contributed to modify both the soil cohesion and the stabilizing forces. Wind effect, slope stability and root reinforcement could be better quantified by means of such a results.

  17. Parameterization experiments performed via synthetic mass movements prototypes generated by 3D slope stability simulator

    Science.gov (United States)

    Colangelo, Antonio C.

    2010-05-01

    The central purpose of this work is to perform a reverse procedure in the mass movement conventional parameterization approach. The idea is to generate a number of synthetic mass movements by means of the "slope stability simulator" (Colangelo, 2007), and compeer their morphological and physical properties with "real" conditions of effective mass movements. This device is an integrated part of "relief unity emulator" (rue), that permits generate synthetic mass movements in a synthetic slope environment. The "rue" was build upon fundamental geomorphological concepts. These devices operate with an integrated set of mechanical, geomorphic and hydrological models. The "slope stability simulator" device (sss) permits to perform a detailed slope stability analysis in a theoretical three dimensional space, by means of evaluation the spatial behavior of critical depths, gradients and saturation levels in the "potential rupture surfaces" inferred along a set of slope profiles, that compounds a synthetic slope unity. It's a meta-stable 4-dimensional object generated by means of "rue", that represents a sequence evolution of a generator profile applied here, was adapted the infinite slope model for slope. Any slope profiles were sliced by means of finite element solution like in Bishop method. For the synthetic slope systems generated, we assume that the potential rupture surface occurs at soil-regolith or soil-rock boundary in slope material. Sixteen variables were included in the "rue-sss" device that operates in an integrated manner. For each cell, the factor of safety was calculated considering the value of shear strength (cohesion and friction) of material, soil-regolith boundary depth, soil moisture level content, potential rupture surface gradient, slope surface gradient, top of subsurface flow gradient, apparent soil bulk density and vegetation surcharge. The slope soil was considered as cohesive material. The 16 variables incorporated in the models were analyzed for

  18. Pixelated neutron image plates

    Science.gov (United States)

    Schlapp, M.; Conrad, H.; von Seggern, H.

    2004-09-01

    Neutron image plates (NIPs) have found widespread application as neutron detectors for single-crystal and powder diffraction, small-angle scattering and tomography. After neutron exposure, the image plate can be read out by scanning with a laser. Commercially available NIPs consist of a powder mixture of BaFBr : Eu2+ and Gd2O3 dispersed in a polymer matrix and supported by a flexible polymer sheet. Since BaFBr : Eu2+ is an excellent x-ray storage phosphor, these NIPs are particularly sensitive to ggr-radiation, which is always present as a background radiation in neutron experiments. In this work we present results on NIPs consisting of KCl : Eu2+ and LiF that were fabricated into ceramic image plates in which the alkali halides act as a self-supporting matrix without the necessity for using a polymeric binder. An advantage of this type of NIP is the significantly reduced ggr-sensitivity. However, the much lower neutron absorption cross section of LiF compared with Gd2O3 demands a thicker image plate for obtaining comparable neutron absorption. The greater thickness of the NIP inevitably leads to a loss in spatial resolution of the image plate. However, this reduction in resolution can be restricted by a novel image plate concept in which a ceramic structure with square cells (referred to as a 'honeycomb') is embedded in the NIP, resulting in a pixelated image plate. In such a NIP the read-out light is confined to the particular illuminated pixel, decoupling the spatial resolution from the optical properties of the image plate material and morphology. In this work, a comparison of experimentally determined and simulated spatial resolutions of pixelated and unstructured image plates for a fixed read-out laser intensity is presented, as well as simulations of the properties of these NIPs at higher laser powers.

  19. Orifice plate cavitation mechanism and its influencing factors

    Institute of Scientific and Technical Information of China (English)

    Wan-zheng AI; Tian-ming DING

    2010-01-01

    The orifice plate energy dissipater is an economic and highly efficient dissipater.However,there is a risk of cavitaion around the orifice plate flow.In order to provide references for engineering practice,we examined the cavitation mechanism around the orifice plate and its influencing factors by utilizing mathematical analysis methods to analyze the flow conditions around the orifice plate in view of gas bubble dynamics.Through the research presented in this paper,the following can be observed:The critical radius and the critical pressure of the gas nucleus in orifice plate flow increase with its initial state parameter τ0;the development speed of bubbles stabilizes at a certain value after experiencing a peak value and a small valley value;and the orifice plate cavitation is closely related to the distribution of the gas nucleus in flow.For computing the orifice plate cavitation number,we ought to take into account the effects of pressure fluctuation.The development time of the gas nucleus from the initial radius to the critical radius is about10-7-10-5 s;therefore,the gas nucleus has sufficient time to develop into bubbles in the negative half-cycle of flow fluctuation.The orifice critical cavitation number is closely related to the orifice plate size,and especially closely related with the ratio of the orifice plate radius to the tunnel radius.The approximate formula for the critical cavitation number of the square orifice plate that only considers the main influencing factor was obtained by model experiments.

  20. Sintering of CaF 2 pellets as nuclear fuel analog for surface stability experiments

    Science.gov (United States)

    Godinho, José R. A.; Piazolo, Sandra; Stennett, Martin C.; Hyatt, Neil C.

    2011-12-01

    To enable a detailed study of the influence of microstructure and surface properties on the stability of spent nuclear fuel, it is necessary to produce analogs that closely resemble nuclear fuel in terms of crystallography and microstructure. One such analog can be obtained by sintering CaF 2 powder. This paper reports the microstructures obtained after sintering CaF 2 powders at temperatures up to 1240 °C. Pellets with microstructure, density and pore structure similar to that of UO 2 spent nuclear fuel pellets were obtained in the temperature range between 900 °C and 1000 °C. When CaF 2 was sintered above 1100 °C the formation of CaO at the grain boundaries caused the disintegration of the pellet due to hydration occurring after sintering. First results from a novel set-up of dissolution experiments show that changes in roughness, dissolution rate and etch pit shape of fluorite surfaces are strongly dependent on the crystallographic orientation of the expose surface. Consequently, the differences observed for each orientation will affect the overall dissolution rate and will lead to uncertainties in the estimation of dissolution rates of spent nuclear fuel.

  1. Performance & stability analysis of a three lobe journal bearing with varying parameters: Experiments and analysis

    Science.gov (United States)

    Biswas, Nabarun; Chakraborti, Prasun; Saha, Ankuran; Biswas, Srijit

    2016-07-01

    3-lobe Hydrodynamic oil journal bearings are widely used in heavy industries as a part of different rotating machinery due to their high level of performances. 3-lobe hydrodynamic oil journal bearing allows the transmission of large amounts of loads at a mean speed of rotation. In this present work, an attempt has been made to investigate the pressure domain and subsequent effects in a 3 lobe journal bearing under different static loads in a stable operating speed. Analytical calculations were carried out with codes generated using Matlab software. Experiments were performed in Journal Bearing test rig incorporating 3-lobe under different loads with stable operating speed of 1000 RPM. It has been observed that an increase in load resulted rise in pressure profile, maximum pressure angle and temperature. A further attempt has been made to see the effect of eccentricity ratio and dynamic viscosity considering no change in the RPM. It has also been observed that dynamic viscosity has a significant effect on the stable operating speed. With the reduction in static load, the stability of operating speed attained at higher values.

  2. Photo-stability of Super-hydrogenated PAHs Determined by Action Spectroscopy Experiments

    Science.gov (United States)

    Wolf, M.; Kiefer, H. V.; Langeland, J.; Andersen, L. H.; Zettergren, H.; Schmidt, H. T.; Cederquist, H.; Stockett, M. H.

    2016-11-01

    We have investigated the photo-stability of pristine and super-hydrogenated pyrene cations ({{{C}}}16{{{H}}}10+m+,m=0,6,{{}} {{or}} {{}}16) by means of gas-phase action spectroscopy. Optical absorption spectra and photo-induced dissociation mass spectra are presented. By measuring the yield of mass-selected photo-fragment ions as a function of laser pulse intensity, the number of photons (and hence the energy) needed for fragmentation of the carbon backbone was determined. Backbone fragmentation of pristine pyrene ions ({{{C}}}16{{{H}}}10+) requires absorption of three photons of energy just below 3 eV, whereas super-hydrogenated hexahydropyrene (C16H{}16+) must absorb two such photons and fully hydrogenated hexadecahydropyrene (C16H{}26+) only a single photon. These results are consistent with previously reported dissociation energies for these ions. Our experiments clearly demonstrate that the increased heat capacity from the additional hydrogen atoms does not compensate for the weakening of the carbon backbone when pyrene is hydrogenated. In photodissociation regions, super-hydrogenated Polycyclic Aromatic Hydrocarbons (PAHs) have been proposed to serve as catalysts for H2 formation. Our results indicate that carbon backbone fragmentation may be a serious competitor to H2 formation at least for small hydrogenated PAHs like pyrene.

  3. Density driven convection with dissolution in porous media: experiment, simulation and linear stability analysis

    Science.gov (United States)

    Meng, Xuhui; Yang, Xiaofan; Guo, Zhaoli

    2016-11-01

    Geological storage of the CO2 in subsurface saline aquifers is a promising way to reduce CO2 emissions. During this process, CO2 first dissolves into pure brine. Then the acidic and denser mixture falls down under the gravity and reacts with the rock. In the present work, a microfluidic experiment is conducted to investigate the density-driven convection with dissolution in porous media. Moreover, the linear stability analysis and numerical simulations are further performed to investigate the interfacial instability. The results demonstrate that front instability can be triggered by the density contrast between the two miscible fluids, leading to the Rayleigh-Taylor instability. While this type of instability can be suppressed by the surface reaction between the fluid and solid phases, which prevents the transport of the denser fluid to the deeper region at the beginning. Over the long term, it is found that the interfacial instability can be influenced by the evolution of the porosity due to the dissolution, which will drive the transport of denser fluid further down. Our investigation shows that the transport of the reactive fluid in porous media depends on the competition among the density contrast, the chemical reaction rate and the evolution of the porosity/permeability.

  4. Photo-stability of super-hydrogenated PAHs determined by action spectroscopy experiments

    CERN Document Server

    Wolf, M; Langeland, J; Andersen, L H; Zettergren, H; Schmidt, H T; Cederquist, H; Stockett, M H

    2016-01-01

    We have investigated the photo-stability of pristine and super-hydrogenated pyrene cations C$_{16}$H$_{10+m}^+, m = 0,6, \\mathrm{\\ or\\ } 16$) by means of gas-phase action spectroscopy. Optical absorption spectra and photo-induced dissociation mass spectra are presented. By measuring the yield of mass-selected photo-fragment ions as a function of laser pulse intensity, the number of photons (and hence the energy) needed for fragmentation of the carbon backbone was determined. Backbone fragmentation of pristine pyrene ions (C$_{16}$H$_{10}^+$) requires absorption of three photons of energy just below 3 eV, whereas super-hydrogenated hexahydropyrene (C$_{16}$H$_{16}^+$) must absorb two such photons and fully hydrogenated hexadecahydropyrene (C$_{16}$H$_{26}^+$) only a single photon. These results are consistent with previously reported dissociation energies for these ions. Our experiments clearly demonstrate that the increased heat capacity from the additional hydrogen atoms does not compensate for the weakening...

  5. Exploring the Stability of Gold Nanoparticles by Experimenting with Adsorption Interactions of Nanomaterials in an Undergraduate Lab

    Science.gov (United States)

    Lee, Chi-Feng; You, Pei-Yun; Lin, Ying-Chiao; Hsu, Tsai-Ling; Cheng, Pi-Yun; Wu, Yu-Xuan; Tseng, Chi-Shun; Chen, Sheng-Wen; Chang, Huey-Por; Lin, Yang-Wei

    2015-01-01

    The proposed experiment can help students to understand the factors involved in the stability of gold nanoparticles (Au NPs) by exploring the adsorption interaction between Au NPs and various substances. The students in this study found that the surface plasmon resonance band of Au NP solutions underwent a red shift (i.e., from 520 to 650 nm)…

  6. Instruments of RT-2 Experiment onboard CORONASPHOTON and their test and evaluation III: Coded Aperture Mask and Fresnel Zone Plates in RT-2/CZT Payload

    CERN Document Server

    Nandi, Anuj; Debnath, D; Chakrabarti, Sandip K; Kotoch, T B; Sarkar, R; Yadav, Vipin K; Girish, V; Rao, A R; Bhattacharya, D; 10.1007/s10686-010-9184-3

    2010-01-01

    Imaging in hard X-rays of any astrophysical source with high angular resolution is a challenging job. Shadow-casting technique is one of the most viable options for imaging in hard X-rays. We have used two different types of shadow-casters, namely, Coded Aperture Mask (CAM) and Fresnel Zone Plate (FZP) pair and two types of pixellated solid-state detectors, namely, CZT and CMOS in RT-2/CZT payload, the hard X-ray imaging instrument onboard the CORONAS-PHOTON satellite. In this paper, we present the results of simulations with different combinations of coders (CAM & FZP) and detectors that are employed in the RT-2/CZT payload. We discuss the possibility of detecting transient Solar flares with good angular resolution for various combinations. Simulated results are compared with laboratory experiments to verify the consistency of the designed configuration.

  7. Peeking at ecosystem stability: making use of a natural disturbance experiment to analyze resistance and resilience.

    Science.gov (United States)

    Bruelheide, Helge; Luginbühl, Ute

    2009-05-01

    To determine which factors contribute most to the stability of species composition in a beech forest after profound disturbance, we made use of a natural experiment caused by a severe windthrow that occurred at a permanent monitoring site in an old beech forest in Lower Saxony (Germany). The floristic composition was recorded for the succeeding five years after the disturbance and used to derive measures of resistance and resilience for plots as well as for individual species. Due to the existence of previously established randomly distributed permanent plots, we had precise information of the pre-disturbance state, including initial cover of the herb layer, species richness, and species composition. Variables describing the floristic change, resistance, and resilience were derived from correspondence analysis allowing for partitioning the effects of variation among plots from those of temporal change. We asked to which degree these variables could be predicted by pre-disturbance state and disturbance intensity. We found that both the pre-disturbance state and the disturbance intensity were good predictors for floristic change and resistance, while they failed to predict resilience. Among the descriptors of the pre-disturbance state the initial cover of the herb layer turned out to be a useful predictor, which is explained by a high vegetation cover buffering against losses and preventing establishment of newcomers. In contrast, species number neither showed a relationship to floristic change nor to resistance. Putative positive effects of species number on stability according to the insurance hypothesis might have been counterbalanced by a disruption of niche complementarity in species-rich communities. Among the descriptors of disturbance intensity, the loss in canopy cover and the change in photosynthetically active radiation after the storm were equally good predictors for the change in floristic composition and resistance. The analysis of the responses of

  8. Surface wave Tomography on the Indian Plate under La Réunion Island from RHUM-RUM experiment data

    Science.gov (United States)

    Mazzullo, Alessandro; Stutzmann, Eleonore; Montagner, Jean-Paul; Barruol, Guilhem; Sigloch, Karin; Maurya, Satish

    2016-04-01

    The island of La Reunion has been created by one of the most active volcanoes in the world, but the origin at depth of the mantle upwelling beneath the hotspot is still controversial. More particularly the interaction between the plume and the ridge is not known. In the framework of the RHUM-RUM project, an array of 57 french and german ocean bottom seismometers (OBS) has been deployed during one year (2012-2013) over an area of 2000 km x 2000 km centered on La Reunion Island. 15 land stations have also been installed in Madagascar, the Comoros and Mozambique. This dataset has been used to obtain a high resolution tomographic model of the South West indian area. For each earthquake-station path, Rayleigh wave fundamental mode phase velocity has been measured using the roller-coaster method in the period range 30-250 seconds. The total dataset consists of 3500 paths. This dataset has then been regionalized and inverted versus depth using a simulated annealing method in which the number and shape of the splines that describe the S-wave velocity model are variable. The model lateral resolution is about 500 km. We observe a good correlation between the tomographic model and surface tectonics down to about 100 km depth. At 50 km depth, a slow velocity anomaly is found beneath the hot-spot of Réunion-Mauritius islands. This slow anomaly is extended along the Rodrigues ridge up to the Indian central ridge which confirms a connection between the plume and the ridge. At greater depth (150 km) a large slow velocity anomaly is observed beneath the Réunion hot-spot elongated in the direction of the African plate motion, that may be related to the spreading of hot plume material. We also observe slow velocities beneath the hot-spots of Marion, Crozet and Kerguelen. Finally, under Comoros archipelago, the slow velocity anomaly may be the signature of the termination of the East African rift.

  9. INL HIP Plate Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  10. Stability and dynamics of droplets on patterned substrates: insights from experiments and lattice Boltzmann simulations.

    Science.gov (United States)

    Varnik, F; Gross, M; Moradi, N; Zikos, G; Uhlmann, P; Müller-Buschbaum, P; Magerl, D; Raabe, D; Steinbach, I; Stamm, M

    2011-05-11

    The stability and dynamics of droplets on solid substrates are studied both theoretically and via experiments. Focusing on our recent achievements within the DFG-priority program 1164 (Nano- and Microfluidics), we first consider the case of (large) droplets on the so-called gradient substrates. Here the term gradient refers to both a change of wettability (chemical gradient) or topography (roughness gradient). While the motion of a droplet on a perfectly flat substrate upon the action of a chemical gradient appears to be a natural consequence of the considered situation, we show that the behavior of a droplet on a gradient of topography is less obvious. Nevertheless, if care is taken in the choice of the topographic patterns (in order to reduce hysteresis effects), a motion may be observed. Interestingly, in this case, simple scaling arguments adequately account for the dependence of the droplet velocity on the roughness gradient (Moradi et al 2010 Europhys. Lett. 89 26006). Another issue addressed in this paper is the behavior of droplets on hydrophobic substrates with a periodic arrangement of square shaped pillars. Here, it is possible to propose an analytically solvable model for the case where the droplet size becomes comparable to the roughness scale (Gross et al 2009 Europhys. Lett. 88 26002). Two important predictions of the model are highlighted here. (i) There exists a state with a finite penetration depth, distinct from the full wetting (Wenzel) and suspended (Cassie-Baxter, CB) states. (ii) Upon quasi-static evaporation, a droplet initially on the top of the pillars (CB state) undergoes a transition to this new state with a finite penetration depth but then (upon further evaporation) climbs up the pillars and goes back to the CB state again. These predictions are confirmed via independent numerical simulations. Moreover, we also address the fundamental issue of the internal droplet dynamics and the terminal center of mass velocity on a flat substrate.

  11. Aespoe Pillar Stability Experiment. Geology and mechanical properties of the rock in TASQ

    Energy Technology Data Exchange (ETDEWEB)

    Staub, Isabelle [Golder Associates AB, Uppsala (Sweden); Andersson, J. Christer; Magnor, Bjoern

    2004-03-01

    An extensive characterization programme has been performed in the drift, TASQ, excavated for the Aespoe Pillar Stability Experiment, APSE, including the rock volume that will host the experiment pillar between the two deposition holes. The two major objectives with the characterization has been to 1) derive material properties for the final numerical modelling of the experiment and 2) to ensure that the pillar location is suitable from a structural and rock mechanical point of view. In summary the following activities have been performed: Geological mapping of the drift, the pilot holes cores and deposition hole DQ0066G01. 3D-visualisation of the geological mapping in the experiment (pillar) volume of TASQ. Convergence measurements during the excavation and back calculation of the results for determination of the stress tensor and the rock mass Young's modulus. Laboratory tests on core samples from the 15{phi}76 mm core boreholes drilled around the pillar volume for determination of: compressive strength, thermal properties and fracture properties. P-wave velocity measurements on core samples and between boreholes for estimation of the excavation damaged zone and rock mass properties. The geological mapping and the 3D-visualisation gives a good description of the TASQ drift in general and the experiment volume in the drift in particular. The fracturing of the drift follows the pattern of the rest of Aespoe. Three fracture sets have been mapped in TASQ. The major fracture set is sub-vertical and trending NW, in principle parallel to {sigma}{sub 1}. This set is the most conductive at Aespoe and is the only water bearing set in TASQ. A second less pronounced set is trending NE, parallel to TASQ, and is also sub-vertical. The third set is sub-horizontal. It is interesting to note that the third set is the only one that almost completely consists of sealed fractures. The first two sets have mostly open fractures. One unique feature in the drift is a heavily

  12. On Choices of Stress Modes for Lower Order Quadrilateral Reissner-Mindlin Plate Elements

    Institute of Scientific and Technical Information of China (English)

    Guanghui Hu; Xiaoping Xie

    2006-01-01

    A kind of stabilized mixed/hybrid scheme for Reissner-Mindlin plates is proposed with conforming isoparametric bilinear interpolations of deflection/rotations. The choice of shear stress modes is discussed. It is shown by numerical experiments that fulfilling an energy orthogonal condition for stress approximations is crucial to avoiding "shear locking".

  13. Water flow experiments and analyses on the cross-flow type mercury target model with the flow guide plates

    CERN Document Server

    Haga, K; Kaminaga, M; Hino, R

    2001-01-01

    A mercury target is used in the spallation neutron source driven by a high-intensity proton accelerator. In this study, the effectiveness of the cross-flow type mercury target structure was evaluated experimentally and analytically. Prior to the experiment, the mercury flow field and the temperature distribution in the target container were analyzed assuming a proton beam energy and power of 1.5 GeV and 5 MW, respectively, and the feasibility of the cross-flow type target was evaluated. Then the average water flow velocity field in the target mock-up model, which was fabricated from Plexiglass for a water experiment, was measured at room temperature using the PIV technique. Water flow analyses were conducted and the analytical results were compared with the experimental results. The experimental results showed that the cross-flow could be realized in most of the proton beam path area and the analytical result of the water flow velocity field showed good correspondence to the experimental results in the case w...

  14. Stabilizing control system preventing loss of synchronism from extension and its actual operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzawa, K.; Yanagihashi, K.; Tsukita, J. [Tokyo Electric Power Co. (Japan); Sato, M.; Nakamura, T.; Takeuchi, A.

    1995-08-01

    This paper presents a stabilizing control system that was implemented to the power system of Tokyo Electric Power Company and worked successfully, shedding the minimum number of generators and preventing the extension of loss of synchronism to the other generators when a severe fault occurred on May 22, 1992. The stabilizing control system measures voltage and current at the rate of 600 Hz, predicts the change of phase angles of generators and decides the minimum number of generators to be shed for stabilization when instability is predicted and sheds them.

  15. The effect of the inflation pressure of tyres on motorcycle weave stability: experiments and simulation

    Science.gov (United States)

    Cossalter, V.; Favaron, V.; Giolo, E.; Jomaa, T.

    2016-10-01

    Increasing the stability of a motorcycle requires an understanding of the optimal conditions of the tyre. The inflation pressure is one of the main parameters that directly affects the tyre properties, which in turn influences motorcycle stability and safety. This paper focuses on the effect of the inflation pressure of the tested tyres on motorcycle weave stability. Experimental data are collected from tests carried out in straight running at constant speed. The data analysis is based on stochastic subspace identification methods. Simulations are performed using an advanced motorcycle multi-body code with parameters measured from the tested vehicle. Finally, the comparison between simulations and experimental tests is discussed. The research results show an agreement between experimental tests and simulations where weave stability increases with inflation pressure for the specified range of tyre pressure.

  16. Electroless plating of low-resistivity Cu–Mn alloy thin films with self-forming capacity and enhanced thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Sung-Te, E-mail: stchen@mail.hust.edu.tw [Department of Electronic Engineering, Hsiuping University of Science and Technology, Dali 412, Taichung, Taiwan (China); Chen, Giin-Shan [Department of Materials Science and Engineering, Feng Chia University, Seatwen 407, Taichung, Taiwan (China)

    2015-11-05

    Previous studies have typically used sputter deposition to fabricate Cu–Mn alloy thin films with concentrated solute additions which have exceeded several atomic percentages, and the electrical resistivity values of the resultant films from previous studies are relatively high, ranging from 2.5 to 3.5 μΩ-cm. Herein, we proposed a different approach by using electroless process to plate dilute Cu–Mn (0.1 at.%) alloy thin films on dielectric layers (SiO{sub 2}). Upon forming-gas annealing, the Mn incorporated into Cu–Mn films was segregated toward the SiO{sub 2} side, eventually converting itself into a few atomic layer thickness at the Cu/SiO{sub 2} interface, and forming films with a low level of resistivity the same as that of pure Cu films (2.0 μΩ-cm). The interfacial layer served as not only a diffusion barrier, but also an adhesion promoter that prevented the film’s agglomeration during annealing at elevated temperatures. The mechanism for the dual-function performance by the Mn addition was elucidated by interfacial bonding analysis, as well as dynamic (adhesive strength) and thermodynamic (surface-tension) measurements. - Highlights: • Electroless plating is proposed to grow dilute (0.1%) Cu–Mn films on SiO{sub 2} layers. • Adequate annealing results in a self-forming of MnO{sub x} at the Cu/SiO{sub 2} interface. • The role of interfacial MnO{sub x} as a barrier and adhesion promoter is demonstrated. • The treated dilute film has a low ρ level of pure Cu, in contrast to concentrated films. • Its potential as a single entity replacement of Cu interconnect is presented.

  17. In vitro experiment of the modular orthopedic plate based on Nitinol, used for human radius bone fractures.

    Science.gov (United States)

    Tarniţă, Daniela; Tarniţă, D N; Hacman, L; Copiluş, C; Berceanu, C

    2010-01-01

    Shape memory alloys (SMAs) and in particular Ni-Ti alloys are commonly used in bioengineering applications as they join important qualities as resistance to corrosion, biocompatibility, fatigue resistance, MR compatibility, kink resistance with two unique thermo-mechanical behaviors: the shape memory effect and the pseudoelastic effect. They allow Ni-Ti devices to undergo large mechanically induced deformations and then to recover the original shape by thermal loading or simply by mechanical unloading. Diaphyseal fractures of the radius and ulna present specific problems not encountered in the treatment of fractures of the shafts of other long bones. The adaptive modular implants based on smart materials represent a superior solution in the osteosynthesis of the fractured bones over the conventional implants known so far. To realize the model of the implant module we used SolidWorks software. The small sizes of the modules enable the surgeon to make small incisions, using surgical techniques minimally invasive, having the following advantages: reduction of soft tissues destruction; eliminating intra-operator infections; reduction of blood losses; the reduction of infection risk; the reduction of the healing time. Numerical simulations of the virtual modular implant are realized using Visual Nastran software. The stress diagrams, the displacements diagram and the strain diagram are obtained. An in vitro experiment is made, simulating the osteosynthesis of a transverse diaphyseal fracture of human radius bone. The kinematical parameters diagrams of the staple are obtained, using SIMI Motion video capture system. The experimental diagram force-displacement is obtained.

  18. Process of electroless plating Cu-Sn-Zn ternary alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Cu-Sn-Zn ternary alloy layer with 10 μm thickness was prepared through electroless plating method. The influences of process conditions including the concentration of metallic salts, reductant and complex agent on Cu-Sn-Zn alloy were studied in details.The stability to bear color changes and corrosion resistance of Cu-Sn-Zn film layer were studied through air-exposure experiment and electrochemical analyses test respectively. The results show that the performances of Cu-Sn-Zn film layer are obviously superior to brass matrix. By use of SEM,EDS and XRD, the morphology, microstructure and chemical composition were investigated. The results show that complex agent can increase the content of Sn and Zn, improve the evenness and compactness and decrease needle holes, therefore the properties of electroless plating layer such as the stability to bear color changes and corrosion resistance are improved remarkably.The probable mechanism of complex agent was discussed.

  19. Transient evolution of the global mode in turbulent swirling jets: experiments and modal stability analysis

    CERN Document Server

    Rukes, Lothar; Paschereit, Oliver; Oberleithner, Kilian

    2016-01-01

    Modal linear stability analysis has proven very successful in the analysis of coherent structures of turbulent flows. Formally, it describes the evolution of a disturbance in the limit of infinite time. In this work we apply modal linear stability analysis to a turbulent swirling jet undergoing a control parameter transient. The flow undergoes a transition from a non-vortex breakdown state to a state with a strong recirculation bubble and the associated global mode. High-speed Particle Image Velocimetry (PIV) measurements are the basis for a local linear stability analysis of the temporarily evolving base flow. This analysis reveals that the onset of the global mode is strongly linked to the formation of the internal stagnation point. Several transition scenarios are discussed and the ability of a frequency selection criterion to predict the wavemaker location, frequency and growth rate of the global mode are evaluated. We find excellent agreement between the linear global mode frequency and the experimental ...

  20. Influence of Previous Crop on Durum Wheat Yield and Yield Stability in a Long-term Experiment

    Directory of Open Access Journals (Sweden)

    Anna Maria Stellacci

    2011-02-01

    Full Text Available Long-term experiments are leading indicators of sustainability and serve as an early warning system to detect problems that may compromise future productivity. So the stability of yield is an important parameter to be considered when judging the value of a cropping system relative to others. In a long-term rotation experiment set up in 1972 the influence of different crop sequences on the yields and on yield stability of durum wheat (Triticum durum Desf. was studied. The complete field experiment is a split-split plot in a randomized complete block design with two replications; the whole experiment considers three crop sequences: 1 three-year crop rotation: sugar-beet, wheat + catch crop, wheat; 2 one-year crop rotation: wheat + catch crop; 3 wheat continuous crop; the split treatments are two different crop residue managements; the split-split plot treatments are 18 different fertilization formulas. Each phase of every crop rotation occurred every year. In this paper only one crop residue management and only one fertilization treatment have been analized. Wheat crops in different rotations are coded as follows: F1: wheat after sugar-beet in three-year crop rotation; F2: wheat after wheat in three-year crop rotation; Fc+i: wheat in wheat + catch crop rotation; Fc: continuous wheat. The following two variables were analysed: grain yield and hectolitre weight. Repeated measures analyses of variance and stability analyses have been perfomed for the two variables. The stability analysis was conducted using: three variance methods, namely the coefficient of variability of Francis and Kannenberg, the ecovalence index of Wricke and the stability variance index of Shukla; the regression method of Eberhart and Russell; a method, proposed by Piepho, that computes the probability of one system outperforming another system. It has turned out that each of the stability methods used has enriched of information the simple variance analysis. The Piepho

  1. Create Your Plate

    Medline Plus

    Full Text Available ... A A A Listen En Español Create Your Plate Create Your Plate is a simple and effective ... and that your options are endless. Create Your Plate! Click on the plate sections below to add ...

  2. Effect of different surface treatments on the stability of stainless steels for use as bipolar plates in low and high temperature proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Richards, J.; Schmidt, K. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Wolfsburg (Germany); Tuebke, J.; Cremers, C. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal (Germany)

    2010-07-01

    The stability of different stainless steels against corrosion under simulated low and high temperature proton exchange membrane fuel cell (PEMFC) operating conditions was studied. These investigations showed a moderate corrosion resistance for a couple of steels under LT-PEMFC conditions. However, for the HT-PEMFC conditions all specimens except one exhibit visible corrosion traces. With regards to their corrosion resistance after different surface treatments results show a minor improvement in corrosion resistance after the electro polishing process for most of the tested stainless steel samples. (orig.)

  3. Design and development of an ambient-temperature continuously-rotating achromatic half-wave plate for CMB polarization modulation on the POLARBEAR-2 experiment

    Science.gov (United States)

    Hill, Charles A.; Beckman, Shawn; Chinone, Yuji; Goeckner-Wald, Neil; Hazumi, Masashi; Keating, Brian; Kusaka, Akito; Lee, Adrian T.; Matsuda, Frederick; Plambeck, Richard; Suzuki, Aritoki; Takakura, Satoru

    2016-07-01

    We describe the development of an ambient-temperature continuously-rotating half-wave plate (HWP) for study of the Cosmic Microwave Background (CMB) polarization by the POLARBEAR-2 (PB2) experiment. Rapid polarization modulation suppresses 1/f noise due to unpolarized atmospheric turbulence and improves sensitivity to degree-angular-scale CMB fluctuations where the inflationary gravitational wave signal is thought to exist. A HWP modulator rotates the input polarization signal and therefore allows a single polarimeter to measure both linear polarization states, eliminating systematic errors associated with differencing of orthogonal detectors. PB2 projects a 365-mm-diameter focal plane of 7,588 dichroic, 95/150 GHz transition-edge-sensor bolometers onto a 4-degree field of view that scans the sky at 1 degree per second. We find that a 500-mm-diameter ambient-temperature sapphire achromatic HWP rotating at 2 Hz is a suitable polarization modulator for PB2. We present the design considerations for the PB2 HWP, the construction of the HWP optical stack and rotation mechanism, and the performance of the fully-assembled HWP instrument. We conclude with a discussion of HWP polarization modulation for future Simons Array receivers.

  4. Design and development of an ambient-temperature continuously-rotating achromatic half-wave plate for CMB polarization modulation on the POLARBEAR-2 experiment

    CERN Document Server

    Hill, Charles A; Chinone, Yuji; Goeckner-Wald, Neil; Hazumi, Masashi; Keating, Brian; Kusaka, Akito; Lee, Adrian T; Matsuda, Frederick; Plambeck, Richard; Suzuki, Aritoki; Takakura, Satoru

    2016-01-01

    We describe the development of an ambient-temperature continuously-rotating half-wave plate (HWP) for study of the Cosmic Microwave Background (CMB) polarization by the POLARBEAR-2 (PB2) experiment. Rapid polarization modulation suppresses 1/f noise due to unpolarized atmospheric turbulence and improves sensitivity to degree-angular-scale CMB fluctuations where the inflationary gravitational wave signal is thought to exist. A HWP modulator rotates the input polarization signal and therefore allows a single polarimeter to measure both linear polarization states, eliminating systematic errors associated with differencing of orthogonal detectors. PB2 projects a 365-mm-diameter focal plane of 7,588 dichroic, 95/150 GHz transition-edge-sensor bolometers onto a 4-degree field of view that scans the sky at $\\sim$ 1 degree per second. We find that a 500-mm-diameter ambient-temperature sapphire achromatic HWP rotating at 2 Hz is a suitable polarization modulator for PB2. We present the design considerations for the PB...

  5. Streak instability and generation of hairpin-vortices by a slotted jet in channel crossflow: Experiments and linear stability analysis

    Science.gov (United States)

    Philip, Jimmy; Karp, Michael; Cohen, Jacob

    2016-01-01

    Streaks and hairpin-vortices are experimentally generated in a laminar plane Poiseuille crossflow by injecting a continuous jet through a streamwise slot normal to the crossflow, with air as the working media. Small disturbances form stable streaks, however, higher disturbances cause the formation of streaks which undergo instability leading to the generation of hairpin vortices. Particular emphasis is placed on the flow conditions close to the generation of hairpin-vortices. Measurements are carried out in the cases of natural and phase-locked disturbance employing smoke visualisation, particle image velocimetry, and hot-wire anemometry, which include, the dominant frequency, wavelength, and the disturbance shape (or eigenfunctions) associated with the coherent part of the velocity field. A linear stability analysis for both one- and two-dimensional base-flows is carried out to understand the mechanism of instability and good agreement of wavelength and eigenfunctions are obtained when compared to the experimental data, and a slight under-prediction of the growth-rates by the linear stability analysis consistent with the final nonlinear stages in transitional flows. Furthermore, an energy analysis for both the temporal and spatial stability analysis revels the dominance of the symmetric varicose mode, again, in agreement with the experiments, which is found to be governed by the balance of the wallnormal shear and dissipative effects rather than the spanwise shear. In all cases the anti-symmetric sinuous modes governed by the spanwise shear are found to be damped both in analysis and in our experiments.

  6. Wheat Grain Yield and Yield Stability in a Long-Term Fertilization Experiment on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    HAO Ming-De; FAN Jun; WANG Quan-Jiu; DANG Ting-Hui; GUO Sheng-Li; WANG Ji-Jun

    2007-01-01

    To provide a scientific basis for sustainable land management,a 20-year fertility experiment Was conducted in Changwu County,Shaanxi Province,China to investigate the effects of long-term application of chemical fertilizers on wheat grain yield and yield stability on the Loess Plateau using regression and stability analysis.The experiment consisted of 17fertilizer treatments.containing the combinations of different N and P levels,with three replications arranged in a randomized complete block design.Nitrogen fertilizer was applied as urea,and P was applied as calcium superphosphate.Fertilizer rates had a large effect on the response of wheat yield to fertilization.Phosphorus,combined with N,increased yield significantly(P≤0.01).In the unfertilized control and the N or P sole application treatments,wheat yield had a declining trend although it was not statistically significant.Stability analysis combined with the trend analysis indicated that integrated use of fertilizer N and P was better than their sole application in increasing and sustaining the productivity of rainfed winter wheat.

  7. Variable Sweep Transition Flight Experiment (VSTFE)-Parametric Pressure Distribution Boundary Layer Stability Study and Wing Glove Design Task

    Science.gov (United States)

    Rozendaal, Rodger A.

    1986-01-01

    The Variable Sweep Transition Flight Experiment (VSTFE) was initiated to establish a boundary-layer transition data base for laminar flow wing design. For this experiment, full-span upper-surface gloves will be fitted to a variable sweep F-14 aircraft. The results of two initial tasks are documented: a parametric pressure distribution/boundary-layer stability study and the design of an upper-surface glove for Mach 0.8. The first task was conducted to provide a data base from which wing-glove pressure distributions could be selected for glove designs. Boundary-layer stability analyses were conducted on a set of pressure distributions for various wing sweep angles, Mach numbers, and Reynolds number in the range of those anticipated for the flight-test program. The design procedure for the Mach 0.8 glove is described, and boundary-layer stability calculations and pressure distributions are presented both at design and off-design conditions. Also included is the analysis of the clean-up glove (smoothed basic wing) that will be flight-tested initially and the analysis of a Mach 0.7 glove designed at the NASA Langley Research Center.

  8. EXPERIMENTS OF HYDRODYNAMICS AND STABILITY OF IMMERSED TUBE TUNNEL ON TRANSPORTATION AND IMMERSING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Effects of environment conditions, such as current, wave etc., are more important for immersed tube tunnel’s transportation and immersing. The hydrodynamics and stability of immersed tube tunnel during its towing and immersing are intersted for departments of design and construction. A serial model tests are made in towing tank and water channel for Nanjing immersed tube tunnel, and the first immersed tunnel has been designed in Yangtzi River in China. The hydrodynamic forces and rope tensions of the tunnel are measured with strain balances when it is towed by ship and immersed by winches for a different current velocity and wave height. In addition, the stability of tunnel for a different ballast water is tested and discussed.

  9. High passive-stability diode-laser design for use in atomic-physics experiments

    CERN Document Server

    Cook, Eryn C; Brown-Heft, Tobias L; Garman, Jeffrey C; Steck, Daniel A

    2012-01-01

    We present the design and performance characterization of an external cavity diode-laser system optimized for high stability, low passive spectral linewidth, low cost, and ease of in-house assembly. The main cavity body is machined from a single aluminum block for robustness to temperature changes and mechanical vibrations, and features a stiff and light diffraction-grating arm to suppress low-frequency mechanical resonances. The cavity is vacuum-sealed, and a custom-molded silicone external housing further isolates the system from acoustic noise and temperature fluctuations. Beam shaping, optical isolation, and fiber coupling are integrated, and the design is easily adapted to many commonly used wavelengths. Resonance data, passive-linewidth data, and passive stability characterization of the new design demonstrate that its performance exceeds published specifications for commercial precision diode-laser systems. The design is fully documented and freely available.

  10. 基于ANSYS和GeoStudio耦合的充填体底板稳定性分级%Stability classification of filling body ’s base plate based on ANSYS and GeoStudio coupling

    Institute of Scientific and Technical Information of China (English)

    林国洪

    2014-01-01

    Cracks of different widths and depths are observed in the cemented backfill roof in Wushan Copper Mine resulted from gravity stress and blasting vibration. The stability of backfill is affected when the cracks reach a point. This paper uses ANSYS software and GeoStudio2007 SIGMA/W module to simulate the stress-strain in the roof fissure filling body. The stability classification of filling body's base plate is studied based on ANSYS and GeoStudio coupling. Corresponding suggestions are put forward according to different stability statuses.%武山铜矿胶结充填体顶板在自重应力、爆破振动等作用下产生的不同宽度和深度的裂隙,当裂隙达到一定规模时将影响充填体的稳定性,文中采用ANSYS软件和GeoStudio2007的SIGMA/W模块来模拟含裂隙充填体顶板的应力应变情况,通过2个数值模拟软件的模拟结果的对比验证,研究含裂隙条件下的充填体稳定性,对充填体顶板在不同深度、宽度裂隙影响下的稳定性进行了分级并针对含裂隙顶板的不同稳定性状态提出了合理的支护建议。

  11. Relations between plate kinematics, slab geometry and overriding plate deformation in subduction zones: insights from statistical observations and laboratory modelling

    Science.gov (United States)

    Heuret, A.; Funiciello, F.; Faccenna, C.; Lallemand, S.

    2005-12-01

    3-D laboratory models have been performed in order to investigate the way plates kinematics (subducting and overriding plate absolute motions and the resulting plate convergence rate) influences the geometry of the slab and the overriding plate deformation in subduction zones. In the experiments a viscous plate of silicone (subducting plate) is pushed beneath another plate, which is itself pushed toward or pulled away from the trench (overriding plate), and sinks into a viscous layer of glucose syrup (upper mantle). The subducting and overriding plate velocities explored the variability field of natural subduction plates kinematics. The overriding plate motion exerts a primary role in the control of slab geometries and overriding plate deformation rates. The experiments have revealed two different subduction behaviours: (Style I) the overriding plate moves toward the trench and shortens at high rates, the slab is flat and deflected when reaching the bottom of the box in a forward direction; (Style II) the overriding plates moves away from the trench and shortens at low rates the slab is steep and deflected on the box bottom in a backward direction. To a lesser extent, increasing subducting plate motion is associated to increasing slab dips and overriding plate shortening. Slab geometry and overriding plate deformation are less sensitive to the overall plate convergence rate. These laboratory models behaviours are consistent with statistical analysis performed on natural subduction zones, and enlighten the first order control exerted by the overriding plate absolute motion, on the geometry adopted by the slab and the way the overriding plate deforms.

  12. Rayleigh-Taylor-Instability Evolution in Colliding-Plasma-Jet Experiments with Magnetic and Viscous Stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Colin Stuart [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States)

    2015-01-15

    The Rayleigh-Taylor instability causes mixing in plasmas throughout the universe, from micron-scale plasmas in inertial confinement fusion implosions to parsec-scale supernova remnants. The evolution of this interchange instability in a plasma is influenced by the presence of viscosity and magnetic fields, both of which have the potential to stabilize short-wavelength modes. Very few experimental observations of Rayleigh-Taylor growth in plasmas with stabilizing mechanisms are reported in the literature, and those that are reported are in sub-millimeter scale plasmas that are difficult to diagnose. Experimental observations in well-characterized plasmas are important for validation of computational models used to make design predictions for inertial confinement fusion efforts. This dissertation presents observations of instability growth during the interaction between a high Mach-number, initially un-magnetized plasma jet and a stagnated, magnetized plasma. A multi-frame fast camera captures Rayleigh-Taylor-instability growth while interferometry, spectroscopy, photodiode, and magnetic probe diagnostics are employed to estimate plasma parameters in the vicinity of the collision. As the instability grows, an evolution to longer mode wavelength is observed. Comparisons of experimental data with idealized magnetohydrodynamic simulations including a physical viscosity model suggest that the observed instability evolution is consistent with both magnetic and viscous stabilization. These data provide the opportunity to benchmark computational models used in astrophysics and fusion research.

  13. Continuous infusion of porcine factor VIII: stability, microbiological safety and clinical experience.

    Science.gov (United States)

    DiMichele, D M; Gorman, P O; Kasper, C K; Mannucci, P M; Santagostino, E; Hay, C R M

    2002-01-01

    Porcine factor VIII (pFVIII) is an effective haemostatic treatment for bleeding in selected patients with FVIII inhibitors. Its use is sometimes associated with a transient fall in platelet count and transfusion reactions, the risk of which may be related to the rate of administration. Theoretical considerations suggest that the administration of pFVIII by continuous infusion should be effective, and could have pharmacokinetic advantages that lead to an improvement in the side-effect profile. The results of a retrospective survey of continuous infusion of pFVIII with respect to clinical safety and efficacy are reported. Porcine FVIII stability and microbiological studies are included. It is concluded that pFVIII given by continuous infusion is safe and effective. The risk of transfusion reactions and fall in platelet count appears to be reduced, compared with bolus administration. Stability studies showed that pFVIII activity declined at room temperature, most rapidly in the dilute solution (5-10 U mL(-1)). More concentrated mixtures showed acceptable stability for up to 24 h using a variety of infusion devices. Various concentrations of pFVIII did not support the growth of Escherichia coli or Staphylococcus aureus. These observations suggest that the porcine factor is suitable for continuous infusion (CI).

  14. Rayleigh-Taylor-instability evolution in colliding-plasma-jet experiments with magnetic and viscous stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Colin Stuart [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States); Univ. of Washington, Seattle, WA (United States)

    2015-01-15

    The Rayleigh-Taylor instability causes mixing in plasmas throughout the universe, from micron-scale plasmas in inertial confinement fusion implosions to parsec-scale supernova remnants. The evolution of this interchange instability in a plasma is influenced by the presence of viscosity and magnetic fields, both of which have the potential to stabilize short-wavelength modes. Very few experimental observations of Rayleigh-Taylor growth in plasmas with stabilizing mechanisms are reported in the literature, and those that are reported are in sub-millimeter scale plasmas that are difficult to diagnose. Experimental observations in well-characterized plasmas are important for validation of computational models used to make design predictions for inertial confinement fusion efforts. This dissertation presents observations of instability growth during the interaction between a high Mach-number, initially un-magnetized plasma jet and a stagnated, magnetized plasma. A multi-frame fast camera captures Rayleigh-Taylor-instability growth while interferometry, spectroscopy, photodiode, and magnetic probe diagnostics are employed to estimate plasma parameters in the vicinity of the collision. As the instability grows, an evolution to longer mode wavelength is observed. Comparisons of experimental data with idealized magnetohydrodynamic simulations including a physical viscosity model suggest that the observed instability evolution is consistent with both magnetic and viscous stabilization. These data provide the opportunity to benchmark computational models used in astrophysics and fusion research.

  15. Modeling Polymer Stabilized Nano-scale Zero Valent Iron Transport Experiments in Porous Media to Understand the Transport Behavior

    Science.gov (United States)

    Mondal, P.; Krol, M.; Sleep, B. E.

    2015-12-01

    A wide variety of groundwater contaminants can be treated with nano-scale zero valent iron (nZVI). However, delivery of nZVI in the subsurface to the treatment zones is challenging as the bare nZVI particles have a higher tendency to agglomerate. The subsurface mobility of nZVI can be enhanced by stabilizing nZVI with polymer, such as carboxymethyl cellulose (CMC). In this study, numerical simulations were conducted to evaluate CMC stabilized nZVI transport behavior in porous media. The numerical simulations were based on a set of laboratory-scale transport experiments that were conducted in a two-dimensional water-saturated glass-walled sandbox (length - 55 cm; height - 45 cm; width - 1.4 cm), uniformly packed with silica sand. In the transport experiments: CMC stabilized nZVI and a non-reactive dye tracer Lissamine Green B (LGB) were used; water specific discharge and CMC concentration were varied; movements of LGB, and CMC-nZVI in the sandbox were tracked using a camera, a light source and a dark box. The concentrations of LGB, CMC, and CMC-nZVI at the sandbox outlet were analyzed. A 2D multiphase flow and transport model was applied to simulate experimental results. The images from LGB dye transport experiments were used to determine the pore water velocities and media permeabilities in various layers in the sand box. These permeability values were used in the subsequent simulations of CMC-nZVI transport. The 2D compositional simulator, modified to include colloid filtration theory (CFT), treated CMC as a solute and nZVI as a colloid. The simulator included composition dependent viscosity to account for CMC injection and mixing, and attachment efficiency as a fitting parameter for nZVI transport modeling. In the experiments, LGB and CMC recoveries were greater than 95%; however, CMC residence time was significantly higher than the LGB residence time and the higher CMC concentration caused higher pressure drops in the sandbox. The nZVI recovery was lower than 40

  16. Inflation expectations and stability in an overlapping generations experiment with money creation

    NARCIS (Netherlands)

    Heemeijer, P.; Hommes, C.; Sonnemans, J.; Tuinstra, J.

    2009-01-01

    We investigate how non-specialists form inflation expectations by running an experiment using a basic Overlapping Generations (OLG) model. The participants of the experiment are students of the University of Amsterdam, who predict inflation during 50 successive periods and are rewarded based on

  17. Inflation expectations and stability in an overlapping generations experiment with money creation

    NARCIS (Netherlands)

    Heemeijer, P.; Hommes, C.; Sonnemans, J.; Tuinstra, J.

    2009-01-01

    We investigate how non-specialists form inflation expectations by running an experiment using a basic Overlapping Generations (OLG) model. The participants of the experiment are students of the University of Amsterdam, who predict inflation during 50 successive periods and are rewarded based on thei

  18. Inflation expectations and stability in an overlapping generations experiment with money creation

    NARCIS (Netherlands)

    Heemeijer, P.; Hommes, C.; Sonnemans, J.; Tuinstra, J.

    2009-01-01

    We investigate how non-specialists form inflation expectations by running an experiment using a basic Overlapping Generations (OLG) model. The participants of the experiment are students of the University of Amsterdam, who predict inflation during 50 successive periods and are rewarded based on thei

  19. Stability of isooctane mixtures with 3-pentanone or biacetyl as fluorescence tracers in combustion experiments

    Science.gov (United States)

    Zhang, Rui; Bohac, Stanislav V.; Sick, Volker

    2006-01-01

    Evidence is presented in the literature that common fluorescence tracer/fuel mixtures used in engine experiments, 3-pentanone/isooctane and biacetyl/isooctane, may decompose during extended use and storage. Investigations presented here show that preferential evaporation of the tracer and not chemical decomposition is responsible for observed decreases in fluorescence signal strength in these experiments.

  20. Scaling of the Sheared-Flow Stabilized Z-Pinch: The Fusion Z-Pinch Experiment ``FuZE''

    Science.gov (United States)

    Nelson, B. A.; Shumlak, U.; Claveau, E. L.; Golingo, R. P.; Weber, T. R.; McLean, H. S.; Tummel, K. K.; Higginson, D. P.; Schmidt, A. E.; UW/LLNL Collaboration

    2016-10-01

    The sheared flow stabilized (SFS) Z-pinch ZaP experiment was constructed based on calculations [1] showing stabilization of kink and sausage instabilities. ZaP experimentally demonstrated production and sustainment of an SFS Z-pinch for a wide range of plasma parameters, with densities up to n =1023 m-3 and a pinch radius of a = 1 cm. [2-4] The SFS Z-pinch is resistant to the instabilities of conventional Z-pinches, yet maintains the same favorable radial scaling, making it an energy-efficient way to achieve fusion-relevant conditions. The ZaP-HD (high density) experiment has demonstrated scaling of the SFS Z-pinch to 2-3 × smaller a and 10 × higher n. [5] Supported by ZaP and ZaP-HD, the Fusion Z-pinch Experiment (FuZE) project investigates scaling plasma parameters toward fusion conditions by decreasing a 2-3 × to 1 mm, and increasing n 10 × to 1025 m-3. The approach combines improved gas injection and flexible power supplies with the successful ZaP SFS Z-pinch formation. Detailed fluid and kinetic simulations complement the experimental studies to gain scientific insight into the plasma behavior and predict scaling to higher performance. Supported by DoE FES, NNSA, and ARPA-E ALPHA.

  1. Segregated copper ratio experiment on transient stability (SeCRETS). Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzone, P. [ed.] [Ecole Polytechnique Federale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne (Switzerland)

    2001-01-01

    Two Nb{sub 3}Sn, steel jacketed, cable-in-conduit conductors have been manufactured with identical non-Cu cross sections and the stabilizer either included in the Nb{sub 3}Sn composite or partly segregated as copper wires. The two conductors are series connected and wound as a bifilar , single layer solenoid, assembled in the high field bore (11 T) of the SULTAN test facility. The operating current is up to 12 kA (400 A/mm{sup 2}). A transverse pulsed field is applied with {delta}B up to 2.7 T, field rate up to 180 T/s and field integral up to 530 T{sup 2}/s. In the dc test, a good agreement is found between the I{sub c} and the T{sub cs} results, both correctly scaling according to the parameters derived from the strand tests. The n-value from the V-I curve is in the range of 15. The current sharing at the high field section is correlated with a local current re-distribution, observed by arrays of miniature Hall sensors, detecting the self-field around the conductor. The ac losses results in the range of 2 to 9 Hz by gas flow calorimetry indicate coupling currents constant, n{tau}, in the range of 1.5 ms at high field, increasing by a factor of 2 with 12 kA transport current. Loss extrapolation to 0 frequency suggests that the loss curve may be not linear outside the test range, with higher n{tau} at lower field rate. The calorimetric loss estimation at the fast field transient (f=15 Hz) indicates n{tau} {approx_equal} 2 ms. The ITER plasma disruption transients have been reproduced by the pulsed coils. Due to the very low ac losses, no quench could be generated in either conductor even reducing the temperature margin below 0.2-0.3 K. Very large field transients, with integral above 100 T{sup 2}/s, are required to quench the conductors. In that range, the conductor without segregated copper has superior performance. Due to the large interstrand resistance (very low ac losses), the segregated copper has marginal contribution to the stability. No evidence of current

  2. Flight Test Experiment Design for Characterizing Stability and Control of Hypersonic Vehicles

    Science.gov (United States)

    Morelli, Eugene A.

    2008-01-01

    A maneuver design method that is particularly well-suited for determining the stability and control characteristics of hypersonic vehicles is described in detail. Analytical properties of the maneuver design are explained. The importance of these analytical properties for maximizing information content in flight data is discussed, along with practical implementation issues. Results from flight tests of the X-43A hypersonic research vehicle (also called Hyper-X) are used to demonstrate the excellent modeling results obtained using this maneuver design approach. A detailed design procedure for generating the maneuvers is given to allow application to other flight test programs.

  3. Toward comparing experiment and theory for corroborative research on hingeless rotor stability in forward flight

    Science.gov (United States)

    Gaonkar, G.

    1987-01-01

    For flap lag stability of isolated rotors, experimental and analytical investigations were conducted in hover and forward flight on the adequacy of a linear quasisteady aerodynamics theory with dynamic flow. Forward flight effects on lag regressing mode were emphasized. A soft inplane hingeless rotor with three blades was tested at advance ratios as high as 0.55 and at shaft angles as high as 20 deg. The 1.62 m model rotor was untrimmed with an essentially unrestricted tilt of the tip path plane. In combination with lag natural frequencies, collective pitch settings and flap lag coupling parameters, the data base comprises nearly 1200 test points (damping and frequency) in forward flight and 200 test points in hover. By computerized symbolic manipulation, a linear model was developed in substall to predict stability margins with mode identification. To help explain the correlation between theory and data it also predicted substall and stall regions of the rotor disk from equilibrium values. The correlation showed both the strengths and weaknesses of the theory in substall ((angle of attack) equal to or less than 12 deg).

  4. EMPIRICAL STUDY OF CAR LICENSE PLATES RECOGNITION

    Directory of Open Access Journals (Sweden)

    Nasa Zata Dina

    2015-01-01

    Full Text Available The number of vehicles on the road has increased drastically in recent years. The license plate is an identity card for a vehicle. It can map to the owner and further information about vehicle. License plate information is useful to help traffic management systems. For example, traffic management systems can check for vehicles moving at speeds not permitted by law and can also be installed in parking areas to se-cure the entrance or exit way for vehicles. License plate recognition algorithms have been proposed by many researchers. License plate recognition requires license plate detection, segmentation, and charac-ters recognition. The algorithm detects the position of a license plate and extracts the characters. Various license plate recognition algorithms have been implemented, and each algorithm has its strengths and weaknesses. In this research, I implement three algorithms for detecting license plates, three algorithms for segmenting license plates, and two algorithms for recognizing license plate characters. I evaluate each of these algorithms on the same two datasets, one from Greece and one from Thailand. For detecting li-cense plates, the best result is obtained by a Haar cascade algorithm. After the best result of license plate detection is obtained, for the segmentation part a Laplacian based method has the highest accuracy. Last, the license plate recognition experiment shows that a neural network has better accuracy than other algo-rithm. I summarize and analyze the overall performance of each method for comparison.

  5. Stability of Continental Lithosphere based on Analogue Experiments with Microwave Induced Internal Heating

    Science.gov (United States)

    Fourel, Loic; Limare, Angela; Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia; Vilella, Kenny; Farnetani, Cinzia; Kaminski, Edouard; Jaupart, Claude

    2015-04-01

    the base. Experimental fluids are mixtures of hydroxyethylcellulose, water and isopropanol or silicon oils. Viscosities are varied within a wide range depending on concentration. The temperature field is visualised via laser induced fluorescence and the velocity field is determined using Particle Image Velocimetry (PIV). An intrinsic density contrast ensures the initial stability of the two layers of fluid and a higher heating rate is applied to the top layer. We characterise the stability of the upper layer depending on the parameters in the system and confront our results to marginal stability analysis.

  6. Underwater electrical discharge in plate to plate configuration

    Science.gov (United States)

    Stelmashuk, Vitaliy

    2016-09-01

    Two main configurations of high voltage electrodes submersed in water have been used for an electrical discharge generation: pin to pin and pin to plate. An electrical breakdown between plate electrodes is generally difficult to reproduce, because there is a uniform and weak electric field. One major advantage of using plate electrodes is their greater ``wear hardness'' to high-energy discharges. The plate electrodes can withstand extremely high energy deposition at which the pin electrode is quickly destroyed. The electrical discharge between plate electrodes can be initiated by creating an inhomogeneity in the electrical field. Two methods of discharge initiation between plate electrodes are proposed for this aim: 1) focusing of a shock wave in the interelectrode region; 2) a bubble injection into the electrode gap. The shock wave creates favourable conditions for the electrical breakdown between the two plate electrodes: it causes that numerous microbubbles of dissolved air start to grow and serve as locations for streamer initiation. In the second method the gas bubble is injected from the one of the electrodes, which has a gas inlet hole on the lateral face for this purpose. A ``volcano'' like morphology of positive streamers are observed in the experiments with weak electric field. The authors are grateful to MEYS grant INGO LG 15013.

  7. Experiment and Simulation of Autoignition in Jet Flames and its Relevance to Flame Stabilization and Structure

    KAUST Repository

    Al-Noman, Saeed M.

    2016-06-01

    Autoignition characteristics of pre-vaporized iso-octane, primary reference fuels, gasolines, and dimethyl ether (DME) have been investigated experimentally in a coflow with elevated temperature of air. With the coflow air at relatively low initial temperatures below autoignition temperature Tauto, an external ignition source was required to stabilize the flame. Non-autoignited lifted flames had tribrachial edge structures and their liftoff heights correlated well with the jet velocity scaled by the stoichiometric laminar burning velocity, indicating the importance of the edge propagation speed on flame stabilization balanced with local flow velocity. At high initial temperatures over Tauto, the autoignited flames were stabilized without requiring an external ignition source. The autoignited lifted flames exhibited either tribrachial edge structures or Mild combustion behaviors depending on the level of fuel dilution. For the iso-octane and n-heptane fuels, two distinct transition behaviors were observed in the autoignition regime from a nozzle-attached flame to a lifted tribrachial-edge flame and then a sudden transition to lifted Mild combustion as the jet velocity increased at a certain fuel dilution level. The liftoff data of the autoignited flames with tribrachial edges were analyzed based on calculated ignition delay times for the pre-vaporized fuels. Analysis of the experimental data suggested that ignition delay time may be much less sensitive to initial temperature under atmospheric pressure conditions as compared with predictions. For the gasoline fuels for advanced combustion engines (FACEs), and primary reference fuels (PRFs), autoignited liftoff data were correlated with Research Octane Number and Cetane Number. For the DME fuel, planar laser-induced fluorescence (PLIF) of formaldehyde (CH2O) and CH* chemiluminescence were visualized qualitatively. In the autoignition regime for both tribrachial structure and mild combustion, formaldehyde were found

  8. Is Cu involved in prion oligopeptide stability? Experiments and numerical simulations

    Science.gov (United States)

    Minicozzi, V.; Morante, S.

    The high-sociological impact of neurodegenerative diseases (like Alzheimer disease, Transmissible Spongiform Encephalopathies, Parkinson disease, etc.) has renewed the interest of researchers in the study of misfolding processes and in particular of the rôle played by metals in plaque formation as their unbalanced concentration can be regarded as a possible concurrent cause of protein aggregation. Metals are essential players in many of the fundamental activities of cells. Storing, metabolism, and trafficking of metals through the cellular membrane and within the cytoplasm are mediated by many proteins via well-tuned mechanisms because of the toxicity of free ions. In this review article, we summarize the results of the most recent experimental and numerical investigations aimed at understanding the possible rôle of Cu in stabilizing the Prion protein structure and in the formation of protein polymers.

  9. Experiments on the stability of a liquid bridge in an axial electric field

    Science.gov (United States)

    Sankaran, Subramanian; Saville, D. A.

    1993-01-01

    The behavior of a neutrally buoyant liquid bridge was studied in the presence of axial electric fields. Silicone oil and a castor-oil-eugenol mixture were used to form cylinders with slenderness ratios larger than pi with strong, axial, dc electric fields. Below a certain field strength, a smooth transition to an axisymmetric, vaselike shape occurred. Circulation patterns were observed in these bridges. At lower field strengths, the bridge shape was more deformed and, at a well-defined field, pinch-off occurred. With ac fields, the field strength required to stabilize the bridge was higher and the collapse of the cylinder was much sharper. Upon interchanging the fluids, a steady axial field was found to destabilize cylinders with slenderness ratios less than 3. This behavior is consistent with that anticipated if the fluids behave as leaky dielectrics but not if they act as perfect dielectrics.

  10. Some experiments on Yaw stability of wind turbines with various coning angles

    Science.gov (United States)

    Bundas, D.; Dugundji, J.

    1981-01-01

    A horizontal axis wind turbine was constructed to study the effect of coning angle on the yawing moments produced. Coning angles of 0 deg, +10 deg and -10 deg were studied in the upwind and downwind cases. Moment and rotational frequency of the blades at each yaw angle setting were taken. It was found that as the coning angle increased from -10 deg to +10 deg in either the upwind or downwind case the stability decreased. The downwind case was slightly more stable for all coning angles than was the upwind case. It is found that all the previous cases were stable for high rotation speeds, but at lower rotation speeds, they were all unstable and could not self start unless held in the wind.

  11. Some experiments on yaw stability of wind turbines with various coning angles

    Energy Technology Data Exchange (ETDEWEB)

    Bundas, D.; Dugundji, J.

    1981-07-01

    A horizontal axis wind turbine, 0.61-m (2.0-ft) diameter, was constructed to study the effect of coning angle on the yawing moments produced. Coning angles of 0/sup 0/, +10/sup 0/, and -10/sup 0/ were studied in the upwind and downwind cases. Moment and rotational frequency of the blades at each yaw angle setting were taken. It was found that as the coning angle was increased from -10/sup 0/ to +10/sup 0/ in either the upwind or downwind case the stability was decreased. Also, the downwind case was slightly more stable for all coning angles than was the upwind case. These findings are compared with theoretical predictions. It was found that all the previous cases were stable for high rotation speeds, but at lower rotation speeds, they were all unstable and could not self-start unless held in the wind.

  12. Refractometric sensitivity and thermal stabilization of fluorescent core microcapillary sensors: theory and experiment.

    Science.gov (United States)

    Lane, S; Marsiglio, F; Zhi, Y; Meldrum, A

    2015-02-20

    Fluorescent-core microcapillaries (FCMs) present a robust basis for the application of optical whispering gallery modes toward refractometric sensing. An important question concerns whether these devices can be rendered insensitive to local temperature fluctuations, which may otherwise limit their refractometric detection limits, mainly as a result of thermorefractive effects. Here, we first use a standard cylindrical cavity formalism to develop the refractometric and thermally limited detection limits for the FCM structure. We then measure the thermal response of a real device with different analytes in the channel and compare the result to the theory. Good stability against temperature fluctuations was obtained for an ethanol solvent, with a near-zero observed thermal shift for the transverse magnetic modes. Similarly good results could in principle be obtained for any other solvent (e.g., water), if the thickness of the fluorescent layer can be sufficiently well controlled.

  13. Caspar plate fixation for the treatment of complex hangman's fractures.

    Science.gov (United States)

    Tuite, G F; Papadopoulos, S M; Sonntag, V K

    1992-05-01

    This report details our recent experience with the surgical treatment of complex hangman's fractures after failure of closed reduction and immobilization in external orthosis. We have successfully treated hangman's fractures in 5 patients with anterior Caspar plate stabilization and C2-C3 interbody fusion. The specific anatomical features of these fractures were complex, rendering the spines of the patients highly unstable. The patients were considered surgical candidates when reduction could not be achieved or maintained with axial traction or halo immobilization. Each patient underwent anterior C2-C3 interbody bone fusion and Caspar plating from C2 to C3. All patients achieved adequate intraoperative reduction and were immobilized postoperatively with a halo vest. The follow-up period ranged from 3 to 28 months and provided a 100% fusion rate with no complications related to plating or nonunion. Our initial experience indicates that anterior C2-C3 interbody bone fusion and Caspar plate fixation is a suitable treatment option for patients with complex hangman's fractures who are not successfully managed nonoperatively.

  14. Road Maintenance Experience Using Polyurethane (PU) Foam Injection System and Geocrete Soil Stabilization as Ground Rehabilitation

    Science.gov (United States)

    Fakhar, A. M. M.; Asmaniza, A.

    2016-07-01

    There are many types of ground rehabilation and improvement that can be consider and implement in engineering construction works for soil improvement in order to prevent road profile deformation in later stage. However, when comes to road maintenance especially on operated expressways, not all method can be apply directly as it must comply to opreation's working window and lane closure basis. Key factors that considering ideal proposal for ground rehabilitation are time, cost, quality and most importantly practicality. It should provide long lifespan structure in order to reduce continuous cycle of maintenance. Thus, this paper will present two approaches for ground rehabilitation, namely Polyurethane (PU) Foam Injection System and Geocrete Soil Stabilization. The first approach is an injection system which consists two-parts chemical grout of Isocynate and Polyol when mixed together within soil structure through injection will polymerized with volume expansion. The strong expansion of grouting causes significant compression and compacting of the surrounding soil and subsequently improve ground properties and uplift sunken structure. The later is a cold in-place recyclying whereby mixture process that combines in-situ soil materials, cement, white powder (alkaline) additive and water to produce hard yet flexible and durable ground layer that act as solid foundation with improved bearing capacity. The improvement of the mechanical behaviour of soil through these two systems is investigated by an extensive testing programme which includes in-situ and laboratory test in determining properties such as strength, stiffness, compressibility, bearing capacity, differential settlement and etc.

  15. Biologic fixation through bridge plating for comminuted shaft fracture of the clavicle: technical aspects and prospective clinical experience with a minimum of 12-month follow-up.

    Science.gov (United States)

    Jung, Gu Hee; Park, Chang-Min; Kim, Jae-Do

    2013-12-01

    For comminuted shaft fracture of clavicle, the operative goal, aside from sound bone healing without complications of direct reduction, is maintenance of the original length in order to maintain the normal biomechanics of adjacent joint. Our bridge plating technique utilizing distraction through a lumbar spreader was expected to be effective for restoring clavicular length with soft tissue preservation. However, there are two disadvantages. First, there is more exposure to radiation compared to conventional plating; and second, it is difficult to control the rotational alignment. Despite these disadvantages, our technique has important benefits, in particular, the ability to preserve clavicular length without soft tissue injury around the fracture site.

  16. The SOUTHERN PUNA Seismic Experiment: Shape of the Subducting Nazca Plate, Areas of Concentrated Mantle and Crustal Earthquakes, and Crustal Focal Mechanisms

    Science.gov (United States)

    Mulcahy, P.; Chen, C.; Kay, S. M.; Brown, L. D.; Alvarado, P. M.; Sandvol, E. A.; Heit, B.; Yuan, X.

    2010-12-01

    The SOUTHERN PUNA Seismic Experiment in the Central Andes between 25° - 28°S and 70° - 65°W recorded data in a 74-instrument array from Dec 07 to Nov 09 with the purpose of evaluating the structure and seismic character of the mantle and crust at the southern end of the Puna-Antiplano Plateau. Hypocenter locations for local and regional mantle earthquakes from 16 months of continuous recording confirm the persistence of the backarc teleseismic Antofalla Gap in intermediate depth mantle seismicity between 25.5° and 27.5°S consistent with the interpretation of a hot mantle wedge under this region. The best located Wadati Benioff Zone events agree with the subducting Nazca Plate contours of Cahill and Isacks (1992) north of 27°S, but show a more abrupt southward shallowing of contours in agreement with the Anderson et al. (2007) contours outlining the projected path of the already subducted Juan Fernandez Ridge. Another prominent feature in the data is the concentration of hypocenters in the Pipanaco nest to the south of the Antofalla Gap between 27° and 29°S. New PUNA results together with available HCMT solutions indicate NW oriented normal and strike-slip faulting in three general clusters within this nest at ~130km, 150km and 180km depth. Hypocenter locations and fault solutions for the Pipanaco Nest suggest flexure associated with steepening of the subducting slab consistent with the revised Wadati Benioff Zone contours. In an area of little to no crustal seismicity in global catalogs over the same time period, hundreds of well-located crustal earthquakes at depths less than 15km were recorded by the PUNA array. Among these earthquakes are three distinct clusters near relatively young volcanic centers. One cluster defines a nest northeast of the < 1 Ma Cerro Blanco caldera. The other two clusters are characterized by large quantities of earthquakes within 24-36 hours (swarms) near the Cerro Galan caldera that last erupted at ~2 Ma and near a ~1 Ma or

  17. Clinical experiences of dynamic stabilizers: Dynesys and Dynesys top loading system for lumbar spine degenerative disease.

    Science.gov (United States)

    Hsieh, Cheng-Ta; Chang, Chih-Ju; Su, I-Chang; Lin, Li-Ying

    2016-04-01

    Dynesys (Dynamic Neutralization System) was designed to overcome the shortcomings of fusion. The Dynesys top loading (DTL) system is a new alternative Dynesys system that can be applied via a minimally invasive procedure. This study aimed to ascertain whether DTL is a suitable device for motion preservation and prevention of instability, and to compare the clinical and radiological outcomes between DTL and Dynesys. In this study, 12 patients were treated with Dynesys and 21 patients were treated with DTL. Back and leg pain were evaluated using the visual analog scale. The Oswestry Disability Index was used to evaluate the patients' function. Range of motion (ROM) at the operative level and for the whole lumbar spine was measured pre- and postoperatively. The length of wound, blood loss, length of hospital stay, and operation duration were also compared. All patients were followed up for 12-76 months. Scores on the visual analog scale and Oswestry Disability Index were significantly improved postoperatively. The median ROM of the whole spine and index level ROM in all patients showed 12.5% and 79.6% loss, respectively. The DTL group exhibited significantly better results in terms of blood loss, wound length, and operation duration, in addition to early ambulation. In conclusion, Dynesys and DTL are semirigid fixation systems that can significantly improve clinical symptoms and signs. Our results suggested that DTL was better than Dynesys as a result of it being a minimally invasive procedure. However, further study with large sample sizes and longer follow-up durations is required to validate the effects of these dynamic stabilizers.

  18. Investigation of CaCO3 fouling in plate heat exchangers

    Science.gov (United States)

    Li, Wei; Zhou, Kan; Manglik, Raj M.; Li, Guan-Qiu; Bergles, Arthur E.

    2016-11-01

    An experimental investigation, coupled with theoretical modeling of CaCO3 fouling in plate-and-frame type heat exchangers (PHEs) have been conducted. Four different plates, made of SS-304, are used in two different surface patterns (chevron and zig-zag) of varying corrugation severity (waviness depth and pitch) and area enhancement. They were further characterized in clean, non-fouled convection by their measured heat transfer coefficients and friction factors in the Reynolds number range of 600-6000. The flow-fouling experiments delineate the effects of temperature and plate-surface geometry on growth rates and stabilization of fouling resistance, along with the anti-fouling behavior of plates coated with a hydrophobic PTFE (Teflon) film. Moreover, the microscopic structure of fouling deposits is mapped in a scanning-electron microscope. Corrugated plates with the largest height-to-pitch ratio and hydraulic diameter are found to have the lowest fouling growth rate and resistance; Teflon-film coating of plate surface is also found to mitigate fouling relative to the performance of bare stainless steel plates. Finally, a semi-empirical fouling model, based on the Prandtl-Taylor analogy, has been devised to describe the experimental data and provide a predictive tool.

  19. Time scales of foam stability in shallow conduits: Insights from analogue experiments

    Science.gov (United States)

    Spina, L.; Scheu, B.; Cimarelli, C.; Arciniega-Ceballos, A.; Dingwell, D. B.

    2016-10-01

    Volcanic systems can exhibit periodical trends in degassing activity, characterized by a wide range of time scales. Understanding the dynamics that control such periodic behavior can provide a picture of the processes occurring in the feeding system. Toward this end, we analyzed the periodicity of outgassing in a series of decompression experiments performed on analogue material (argon-saturated silicone oil plus glass beads/fibers) scaled to serve as models of basaltic magma. To define the effects of liquid viscosity and crystal content on the time scale of outgassing, we investigated both: (1) pure liquid systems, at differing viscosities (100 and 1000 Pa s), and (2) particle-bearing suspensions (diluted and semidiluted). The results indicate that under dynamic conditions (e.g., decompressive bubble growth and fluid ascent within the conduit), the periodicity of foam disruption may be up to several orders of magnitude less than estimates based on the analysis of static conditions. This difference in foam disruption time scale is inferred to result from the contribution of bubble shear and bubble growth to inter-bubble film thinning. The presence of particles in the semidiluted regime is further linked to shorter bubble bursting times, likely resulting from contributions of the presence of a solid network and coalescence processes to the relative increase in bubble breakup rates. Finally, it is argued that these experiments represent a good analogue of gas-piston activity (i.e., the periodical rise-and-fall of a basaltic lava lake surface), implying a dominant role for shallow foam accumulation as a source process for these phenomena.

  20. On the Quintic Nonlinear Schrödinger Equation Created by the Vibrations of a Square Plate on a Weakly Nonlinear Elastic Foundation and the Stability of the Uniform Solution

    OpenAIRE

    Nohara, Ben T.; Arimoto, Akio

    2007-01-01

    Plates are common structural elements of most engineering structures, including aerospace, automotive, and civil engineering structures. The study of plates from theoretical perspective as well as experimental viewpoint is fundamental to understanding of the behavior of such structures. The dynamic characteristics of plates, such as natural vibrations, transient responses for the external forces and so on, are especially of importance in actual environments. In this...

  1. Modeling of Nike Experiments on Acceleration of Planar Targets Stabilized with a Short Spike

    Science.gov (United States)

    Metzler, N.; Velikovich, A. L.; Gardner, J. H.

    2005-10-01

    A short sub-ns laser pulse (spike) produces a decelerating shock wave and a rarefaction wave immediately behind it, shaping a density gradient in the target. The following main pulse ``rides'' this graded density profile. We have demonstrated how the deceleration of the ablation front following the shock wave suppresses laser imprint and delays perturbation growth in the target [1]. We report the results of 2D numerical modeling of experiments on Nike laser at NRL, with its recently developed short-pulse capability, for a low-energy spike which does not affect the target adiabat. We studied the effect of spike on laser imprint on smooth planar targets and on the growth of perturbations imposed as single-mode ripples on the irradiated surface of the targets. For all cases, delay of the onset and/or suppression of the rate of the mass perturbation growth due to the spike are robust and significant enough to be observable on Nike. [1] N. Metzler et al., Phys. Plasmas 6, 3283 (1999); 9, 5050 (2002); 10, 1897 (2003).

  2. Nike Experiments on Acceleration of Planar Targets Stabilized with a Short Spike Pulse^1

    Science.gov (United States)

    Weaver, J. L.; Velikovich, A. L.; Metzler, N.; Aglitskiy, Y.; Oh, J.; Mostovych, A. N.; Gardner, J. H.

    2005-10-01

    Theoretical work has shown that a low energy spike pulse in front of the drive laser pulse can help mitigate the growth of hydrodynamic instabilities in targets for inertial confinement fusion.[1]^ While other experiments [2] used higher spike pulse energies, this study reports the influence of a lower energy spike and longer spike-main pulse delay on the acceleration of planar CH targets. Time evolution of preimposed sinusoidal ripples on the target surface was observed using a monochromatic x-ray imaging system. Delayed onset and/or suppression of mode growth was found for the spike prepulse shots compared to those with a low intensity foot, in good agreement with predictions from FAST2D simulations. The propagation velocity of the decaying shock wave from the spike pulse was measured with VISAR and was also in good agreement with an analytical prediction.[3] [1] Metzler et al., Phys. Plasmas 6, 3283 (1999); 9, 5050 (2002); 10, 1897 (2003);Goncharov et al., Phys. Plasmas 10, 1906 (2003) ;Betti et al., Phys Plamas 12, 042703 (2005) ;[2]Knauer et al., Phys. Plasmas 12, 056306 (2005) ; [3]Velikovich et al., Phys. Plasmas 10, 3270 (2003). ^1Work supported by U. S. Department of Energy

  3. Parameters Inversion on Bird Constitutive Model Part Ⅰ:Study on Experiment of Bird Striking on Plate%鸟体本构模型参数反演I:鸟撞平板试验研究

    Institute of Scientific and Technical Information of China (English)

    刘军; 李玉龙; 郭伟国; 石霄鹏; 彭刚; 叶彪

    2011-01-01

    为了结合数值模拟得到鸟撞过程中的鸟体本构模型参数,对鸟撞平板进行了试验研究.鸟体质量分别为1.8kg和3.6 kg,平板材料采用厚度为10 mm和14 mm的LYl2铝合金和厚度为4.5 mm和8.0 mm的45#钢,鸟体撞击速度为70、120、170 m/s,共进行了16组鸟撞试验.采用动态数据采集系统获得了鸟撞过程中平板的位移和应变及撞击支反力等物理量的时间历程数据,运用高速摄像系统记录了鸟撞平板动响应变形的全过程.试验结果表明:每组两次试验从撞击速度到试验结果重复性均很好;鸟撞作用时间为ms量级,属冲击动力学行为,且鸟体与平板之间存在强烈的耦合作用;平板变形较大,中心点最大位移是平板厚度的7.9倍;撞击速度越高,鸟体的流体特性越明显.%In order to obtain the mechanical parameters of the bird during the process of bird striking, numerical simulations and experiments of bird striking on plate are studied in the paper. The bird mass is 1.8 kg and 3. 6 kg respectively, and the plate is made by LY12 aluminium alloy with the thickness of 10 mm and 14 mm and 45# steel with the thickness of 4.5 mm and 8.0 mm. Sixteen groups of experiments are performed in the present paper with the bird velocity at 70,120,170 m/s,respectively. The histories of displacement-time and strain-time of plate as well as the force-time are measured by the dynamic data acquisition system, and the whole process of dynamic response during bird striking on plate is recorded by highspeed camera system. The results of the experiments indicate that the repeatability of the impacting velocities and the measured results for twice experiments in one group are very good. The reaction time of bird striking is millisecond, so its behavior belongs to impact dynamics; there exists strong coupling between the bird and the plate. The deformation of the plate is very big and the ratio of the plate displacement at the center point to the

  4. Computational modelling of long bone fractures fixed with locking plates - How can the risk of implant failure be reduced?

    LENUS (Irish Health Repository)

    Nassiri, M

    2013-03-01

    The Locking Compression Plate (LCP) is part of a new plate generation requiring an adapted surgical technique and new thinking about commonly used concepts of internal fixation using plates. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability and the risk of implant failure can best be controlled.

  5. Stability of quasi-Keplerian Shear Flow in a Laboratory Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Schartman, Ethan; Ji, Hantao; Burin, Michael J.; Goodman, Jeremy

    2012-06-19

    Subcritical transition to turbulence has been proposed as a source of turbulent viscosity required for the associated angular momentum transport for fast accretion in Keplerian disks. Previously cited laboratory experiments in supporting this hypothesis were performed either in a di erent type of flow than Keplerian or without quantitative measurements of angular momentum transport and mean flow profile, and all of them appear to su er from Ekman e ects, secondary flows induced by nonoptimal axial boundary conditions. Such Ekman e ects are expected to be absent from astronomical disks, which probably have stress-free vertical boundaries unless strongly magnetized. Aims. To quantify angular momentum transport due to subcritical hydrodynamic turbulence, if exists, in a quasi-Keplerian flow with minimized Ekman e ects. Methods.We perform a local measurement of the azimuthal-radial component of the Reynolds stress tensor in a novel laboratory apparatus where Ekman e ects are minimized by flexible control of axial boundary conditions. Results.We find significant Ekman e ects on angular momentum transport due to nonoptimal axial boundary conditions in quasi-Keplerian flows. With the optimal control of Ekman e ects, no statistically meaningful angular momentum transport is detected in such flows at Reynolds number up to two millions. Conclusions. Either a subcritical transition does not occur, or, if a subcritical transition does occur, the associated radial transport of angular momentum in optimized quasi-Keplerian laboratory flows is too small to directly support the hypothesis that subcritical hydrodynamic turbulence is responsible for accretion in astrophysical disks. Possible limitations in applying laboratory results to astrophysical disks due to experimental geometry are discussed.

  6. Stability of quasi-Keplerian Shear Flow in a Laboratory Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Schartman, Ethan; Ji, Hantao; Burin, Michael J.; Goodman, Jeremy

    2012-06-19

    Subcritical transition to turbulence has been proposed as a source of turbulent viscosity required for the associated angular momentum transport for fast accretion in Keplerian disks. Previously cited laboratory experiments in supporting this hypothesis were performed either in a di erent type of flow than Keplerian or without quantitative measurements of angular momentum transport and mean flow profile, and all of them appear to su er from Ekman e ects, secondary flows induced by nonoptimal axial boundary conditions. Such Ekman e ects are expected to be absent from astronomical disks, which probably have stress-free vertical boundaries unless strongly magnetized. Aims. To quantify angular momentum transport due to subcritical hydrodynamic turbulence, if exists, in a quasi-Keplerian flow with minimized Ekman e ects. Methods.We perform a local measurement of the azimuthal-radial component of the Reynolds stress tensor in a novel laboratory apparatus where Ekman e ects are minimized by flexible control of axial boundary conditions. Results.We find significant Ekman e ects on angular momentum transport due to nonoptimal axial boundary conditions in quasi-Keplerian flows. With the optimal control of Ekman e ects, no statistically meaningful angular momentum transport is detected in such flows at Reynolds number up to two millions. Conclusions. Either a subcritical transition does not occur, or, if a subcritical transition does occur, the associated radial transport of angular momentum in optimized quasi-Keplerian laboratory flows is too small to directly support the hypothesis that subcritical hydrodynamic turbulence is responsible for accretion in astrophysical disks. Possible limitations in applying laboratory results to astrophysical disks due to experimental geometry are discussed.

  7. 纤维增强复合材料三明治板的破片穿甲实验%Armor-piercing experiment on fragment against sandwich plate with fiber reinforced composite cores

    Institute of Scientific and Technical Information of China (English)

    徐豫新; 王树山; 严文康; 虢忠仁

    2012-01-01

    研究了钢板一纤维增强复合材料板一钢板构成的三明治结构对破片的防护性能。通过破片模拟弹丸(FSP)高速撞击不同结构三明治板实验,获得FSP弹丸贯穿16种三明治板的弹道极限,分析结构特征对纤维增强复合材料三明治板比吸收能的影响。结果表明,叠层芳纶、玻纤基三明治板较单层结构三明治板比吸收能分别提高了8.31%和16.09%,8mm面板+8mm夹层+6mm背板芳纶、玻纤基三明治板较4mm面板+8mm夹层+10mm背板的芳纶、玻纤基三明治板比吸收能分别提高了37.72%和25.35%;芳纶、玻纤基三明治板的比吸收能均随复合材料夹层厚度的增加呈指数递增,夹层基板的抗拉性能是影响三明治板比吸收能的重要因素;同面密度下,厚面板、薄背板及多层叠合夹层结构的三明治板具有更高的比吸收能。%The defense performance of sandwich structure of steel plate - fiber composite material plate - steel plate structure against fragment was investigated. By the experiment on the fragment simulation projectile (FSP), impacted to different kinds of sandwich plate with high velocity, the ballistic limits of fragment pierced 16 kinds of sandwich plates were obtained, and the influence of structure characteristic on the speeifie energy absorption of the sandwich plate was analyzed. The results show that the specific energy absorption of laminated sandwich structure on aramid and glass fiber is 8. 31% and 16.09% higher than that of a single-layer structure, respectively. The specific energy absorption of the sandwich structure with 8 mm front+ 8mm core+ 6 mm back on aramid and glass fiber is 37.72% and 25. 35% higher than the one with 4 mm frontq-8 mm core+10 mm back, respectively. The speeific energy absorption of sandwich plate exponentially increases with the thickness of fiber composite sandwich. The tensile properties of middle layer plate is an

  8. Experiment study on heat transfer coefficient in climbing film plate heat exchanger%升膜式板式换热器的换热性能研究

    Institute of Scientific and Technical Information of China (English)

    高晓凯; 陶乐仁; 高立博; 黄理浩

    2013-01-01

    升膜蒸发是在换热器表面形成一层薄液膜,薄膜蒸发能够强化换热.文中研究采用光滑铜板的板式升膜蒸发器,以去离子水作为介质,在不同进水流量、不同加热量(热流密度)下,测定换热器某些点的局部换热系数,计算出总的换热系数,研究影响板式换热器升膜蒸发的因素和变化趋势.%A thin liquid film can be formed on the outer surface in the heat exchanger and can enhance heat transfer. This paper focused on studying smooth plate of copper in plate heat exchanger for deion - water as working fluids. Based on the different inlet - water flow and the different heat - flow density, the heat - transfer coefficients in partial positions were measured and the oveall coefficient could be concluded. The factors of affect the climbing film evaporation in plate heat exchanger and trendency were also analyzed.

  9. Prevention of ARD through stabilization of waste rock with alkaline by-products : results from a meso-scale experiment

    Energy Technology Data Exchange (ETDEWEB)

    Backstrom, M.; Allard, B. [Orebro Univ. (Sweden). Man-Technology Environment Research Centre; Sartz, L.; Karlsson, S. [Orebro Univ. (Sweden). Man-Technology Environment Research Centre; Bergskraft Bergslagen, Kopparberg (Sweden)

    2010-07-01

    Mine waste can be mixed with alkaline materials to neutralize and increase the immobilization of trace elements. An impermeable layer can also be created if the alkaline additions react with the waste to form hardpans. Alkaline injection processes have been used in the western United States, where approximately 2 to 3.5 million tonnes of mine tailings have been limed with calcite, calcium hydroxide (Ca(OH){sub 2}), and calcium oxide (CaO). In this study, stabilization experiments were conducted to simulate conditions where weathered mine waste was mixed with various alkaline materials. The aim of the study was to determine the optimal conditions for preventing the oxidation of mine waste isolating surfaces. The alkaline materials included fly ash, lime mud, green liquor dregs, and lime kiln dust. The mine waste and alkaline materials were layered in barrels. Expanded clay aggregates were used to minimize the risk of clogging. Results of the experiments showed that the pH in the alkaline-treated systems increased between 1.3 and 27 pH units when compared with untreated reference samples. The increased pH resulted in a decrease in trace element concentrations of approximately 96 percent. The samples containing fly ash performed better than other systems. 4 refs., 1 tab., 2 figs.

  10. Compressibility and structural stability of CeN from experiment and theory. The B1–B2 transition

    DEFF Research Database (Denmark)

    Staun Olsen, J.; Jørgensen, J.-E.; Gerward, L.

    2012-01-01

    The high-pressure structural stability of CeN is investigated by experiment and theory. Experiments are carried out by energy-dispersive X-ray diffraction and synchrotron radiation, using a diamond anvil cell, to a maximum pressure of 77GPa. The experimental results are in remarkably good agreement...... with ab initio calculations using the full-potential linear muffin-tin orbital method within the generalized gradient approximation (GGA). The experimental zero pressure bulk modulus is B0=156(3)GPa, the pressure derivative being constrained to B0′=4.00. The corresponding calculated data are B0=158.1GPa...... and B0′=3.3. We report here the first experimental observation of the transformation of CeN from the ambient B1 type crystal structure to the B2 type. The onset of the transition is in the range 65–70GPa, and the relative volume change at the transition is ΔV/V=−10.9(3)%. These data compare well...

  11. Fringe Capacitance of a Parallel-Plate Capacitor.

    Science.gov (United States)

    Hale, D. P.

    1978-01-01

    Describes an experiment designed to measure the forces between charged parallel plates, and determines the relationship among the effective electrode area, the measured capacitance values, and the electrode spacing of a parallel plate capacitor. (GA)

  12. Well-plate freeze-drying

    DEFF Research Database (Denmark)

    Trnka, Hjalte; Rantanen, Jukka; Grohganz, Holger

    2015-01-01

    due to increasing amount of amorphous matter in the samples was observed in both vials and well plates. Cake collapse was found to be representative in well plates and could be effectively quantified using image analysis. Reconstitution time was also found to be equal in all three platforms. Finally......Abstract Context: Freeze-drying in presence of excipients is a common practice to stabilize biomacromolecular formulations. The composition of this formulation is known to affect the quality of the final product. Objective: The aim of this study was to evaluate freeze-drying in well-plates...... as a high throughput platform for formulation screening of freeze-dried products. Methods: Model formulations consisting of mannitol, sucrose and bovine serum albumin were freeze-dried in brass well plates, plastic well plates and vials. Physical properties investigated were solid form, residual moisture...

  13. Lasting mantle scars lead to perennial plate tectonics.

    Science.gov (United States)

    Heron, Philip J; Pysklywec, Russell N; Stephenson, Randell

    2016-06-10

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a 'perennial' phenomenon.

  14. Lasting mantle scars lead to perennial plate tectonics

    Science.gov (United States)

    Heron, Philip J.; Pysklywec, Russell N.; Stephenson, Randell

    2016-06-01

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a `perennial' phenomenon.

  15. Study on improving levitation stability from high frequency vibration for the application of a seismic isolation device

    Energy Technology Data Exchange (ETDEWEB)

    Jang, H.K.; Song, D.; Kim, S.B. [Hanyang University, 17 Haengdang-Dong, Seongdong-Gu, Seoul 133-791 (Korea, Republic of); Han, S.C.; Lee, J.P. [Korea Electric Power Research Institute, 103-16, Munji-Ro, Yuseong-Gu, Daejon 305-760 (Korea, Republic of); Kim, S.J. [Korea Institute of Science and Technology, 39-1 Hawolgok-Dong, Seongbuk-Gu, Seoul 136-791 (Korea, Republic of); Sung, T.H., E-mail: sungth@hanyang.ac.kr [Hanyang University, 17 Haengdang-Dong, Seongdong-Gu, Seoul 133-791 (Korea, Republic of)

    2011-11-15

    We model arrangement of permanent magnet (PM) and copper plate with superconductor levitation. We examine effect of eddy current based on different arrangement of PM and copper plate. Increasing thickness and area of copper plate will increase eddy current effect until the saturation point. Greater eddy current will be occurred when polarity of PM will be changed. Eddy current effects depend on copper plate dimension and changing PM polarity. The stability of superconductor levitation is depending on the pinning force. However, when an external force such as the earthquake with a high magnitude higher than the pinning force is exerted, the levitated permanent magnet (PM) can become unstable and destroyed. In order to improve the stability of the levitation, a copper plate was inserted in between the HTS (high temperature superconductor) bulk and the PM. And the more stabilized levitation can be achieved by applying eddy current that is caused by PM and the copper plate. In this study, various arrangements of PM, the thickness of copper plate, the area and gap length between PM and the copper plate were carried out. The eddy current was greater in the arrangement where polarity was changed with parallel to a moving shaker than the arrangement where polarity was not changed. And also, the eddy current became greater as the gap length between the PM and copper plate decreased. The highest value of the eddy current was measured at a copper plate thickness of 5 mm and a size of 80 mm x 80 mm. From the eddy current experiments, a copper plate (80 mm x 80 mm x 5 mm) inserted between the 7 mm gap length of the HTS bulk and the PM was resulted in a higher stiffness value of 65% compared to no copper plate stiffness value.

  16. 光纤传输激光驱动飞片实验研究%Fiber-coupled laser-driven flyer plates experiments

    Institute of Scientific and Technical Information of China (English)

    赵兴海; 赵翔; 高杨; 杨席仕伟; 苏伟

    2011-01-01

    构建了一种基于光纤传输高功率激光的飞片发射系统,并测试了飞片速度.飞片膜层为三明治结构:铝烧蚀层、氧化铝隔离层和铝飞片产生层.飞片膜层采用磁控溅射技术沉积在玻璃衬底上,总厚度为5.5μm.激光辐照铝膜层产生高温高压等离子体,驱动剩余膜层产生高速飞片,速度达数km/s.同时,实验研究了光纤传能系统的输出激光空间分布特性和传输激光能量容量,它们决定了飞片的平面性和最大速度.光纤端面损伤是限制光纤传输激光能量容量的关键因素,光纤端面通过精密机械抛光和激光预处理可以获得理想的抗激光损伤能力.采用基于光纤阵列探针的时间序列测试技术获得了飞片的平均速度,并评估了飞片的平面性.采用搭建的基于光纤传输高功率激光的飞片发射系统获得了速度达1.7km/s、直径接近1mm的高速飞片.%A system for the launch of hypervelocity flyer plates is developed,characterized and applied.Laser-driven flyers are launched from substrate backed aluminum-alumina- aluminum sandwiched films.A laser-induced plasma is used to drive flyers with a thicknesses of a 5.5μm and a diameter of less than 1 mm,and typically,the flyer plates can achieve velocities of a few kilometers per second.These flyer plates have several applications ranging from micrometeorite simulation to laser ignition.The flyer plates considered here have three layers:an ablation layer for forming plasma;an insulating layer;and a final thicker layer for forming the final flyer plate.The optical fiber delivery system determines the spatial profile of the laser spot and power capacity.A technique and procedure for coupling high power laser pulse into optical fiber is developed.The surface finish of the fiber is found to be a critical factor.This fiber optic system is successfully used to launch flyer plates.Measurements of the flyer performance including the mean velocities and

  17. Two-stage urethroplasty is a better choice for proximal hypospadias with severe chordee after urethral plate transection:a single-center experience

    Institute of Scientific and Technical Information of China (English)

    Da-Chao Zheng; Zhong Wang; Hai-Jun Yao; Zhi-Kang Cai; Jun Da; Qi Chen; Yan-Bo Chen; Ke Zhang; Ming-Xi Xu; Mu-Jun Lu

    2015-01-01

    It is still debatable whether single‑ or two‑stage urethroplasty is a more suitable technique for treating hypospadias with severe chordee after urethral plate transection. This retrospective study evaluated these two techniques. A total of 66 patients of proximal hypospadias with severe chordee were divided into two groups according to the techniques they underwent: 32 and 34 patients underwent single‑stage (Duckett) or two‑stage urethroplasty, respectively. Median ages at presentation were 7.5 years and 11.0 years in single‑stage and two‑stage repair groups, respectively. Median follow‑ups were 28.5 months (20−60 months) and 35 months (18−60 months) in the single‑stage and two‑stage groups, respectively. The meatus of the neourethra was located at the top of the glans in all patients. No recurrence of chordee was found during follow‑up, and all patients or parents were satisfied with the penile length and appearance. Complications were encountered in eight patients in both groups, with no statistically significant differences between the two techniques. The late complication rate of stricture was higher after the single‑stage procedure (18.75% vs 0%). The complication rate after single‑stage repairs was significantly lower in the prepubescent subgroup (10.52%) than in the postpubescent cohort (46.15%). These results indicate that the urethral plate transection effectively corrects severe chordee associated with proximal hypospadias during the intermediate follow‑up period. Considering the higher rate of stricture after single‑stage urethroplasty, two‑stage urethroplasty is recommended for proximal hypospadias with severe chordee after urethral plate transection.

  18. Two-stage urethroplasty is a better choice for proximal hypospadias with severe chordee after urethral plate transection: a single-center experience

    Science.gov (United States)

    Zheng, Da-Chao; Yao, Hai-Jun; Cai, Zhi-Kang; Da, Jun; Chen, Qi; Chen, Yan-Bo; Zhang, Ke; Xu, Ming-Xi; Lu, Mu-Jun; Wang, Zhong

    2015-01-01

    It is still debatable whether single- or two-stage urethroplasty is a more suitable technique for treating hypospadias with severe chordee after urethral plate transection. This retrospective study evaluated these two techniques. A total of 66 patients of proximal hypospadias with severe chordee were divided into two groups according to the techniques they underwent: 32 and 34 patients underwent single-stage (Duckett) or two-stage urethroplasty, respectively. Median ages at presentation were 7.5 years and 11.0 years in single-stage and two-stage repair groups, respectively. Median follow-ups were 28.5 months (20−60 months) and 35 months (18−60 months) in the single-stage and two-stage groups, respectively. The meatus of the neourethra was located at the top of the glans in all patients. No recurrence of chordee was found during follow-up, and all patients or parents were satisfied with the penile length and appearance. Complications were encountered in eight patients in both groups, with no statistically significant differences between the two techniques. The late complication rate of stricture was higher after the single-stage procedure (18.75% vs 0%). The complication rate after single-stage repairs was significantly lower in the prepubescent subgroup (10.52%) than in the postpubescent cohort (46.15%). These results indicate that the urethral plate transection effectively corrects severe chordee associated with proximal hypospadias during the intermediate follow-up period. Considering the higher rate of stricture after single-stage urethroplasty, two-stage urethroplasty is recommended for proximal hypospadias with severe chordee after urethral plate transection. PMID:25248656

  19. Influence of plate-bone contact on cyclically loaded conically coupled locking plate failure.

    Science.gov (United States)

    Rotne, Randi; Bertollo, Nicky; Walsh, William; Dhand, Navneet K; Voss, Katja; Johnson, Kenneth A

    2014-03-01

    The maintenance of friction between locking plates and bone is not essential, so that they can be applied with a gap between the plate and underlying bone. We hypothesised that the presence of a gap under a locking plate with a conical coupling mechanism would reduce fixation stability or allow uncoupling of the locking screws from the plate. Locking plates with two conically coupled locking screws were applied to 6 pairs of adult canine femora. One of each pair had plate to bone contact and the contralateral construct had a 2 mm plate to bone gap. Constructs were cyclically loaded in cantilever bending with 10 percent incremental increases every 1000 cycles at 2 Hz, starting at 250 N. The constructs were fatigued to failure. To evaluate fatigue life of the conical coupling, testing was repeated with aluminium tubing replacing the bone, to eliminate screw-bone cutout failure. The mean sustained loads and cycles to failure in the contact group (420.80, standard error [SE] 14.97 N; 7612.00, SE 574.70 cycles) were significantly greater than in the gap group (337.50, SE 14.97 N; 4252.00, SE 574.70 cycles), (pplate fatigue and breaking, with one construct having elevation of the plate over the screw head. Elevation of locking plates with a conical coupling system by 2 mm from the bone reduced construct fatigue life but did not result in screw head uncoupling from the plate. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. CMS Resistive plate Champers

    CERN Document Server

    Zainab, Karam

    2013-01-01

    There are many types of gas detectors which are used in CERN in LHC project, There is a main parts for the gas detectors which must be in all gas detectors types like Multiwire proportional chambers, such as the micromesh gaseous structure chamber (the MicroMegas), Gas-electron multiplier (GEM) detector, Resistive Plate Champers... Compact Muon Solenoid (CMS) experiment detecting muons which are powerful tool for recognizing signatures of interesting physics processes. The CMS detector uses: drift tube (DT), cathode strip chamber (CSC) and resistive plate chamber (RPC). Building RPC’s was my project in summer student program (hardware). RPC’s have advantages which are triggering detector and Excellent time resolution which reinforce the measurement of the correct beam crossing time. RPC’s Organized in stations :  RPC barrel (RB) there are 4 stations, namely RB1, RB2, RB3, and RB4  While in the RPC endcap (RE) the 3 stations are RE1, RE2, and RE3. In the endcaps a new starion will be added and this...

  1. A Frequency Transfer and Cleanup System for Ultra-High Stability at Both Long and Short Times for the Cassini Ka-Band Experiment

    Science.gov (United States)

    Calhoun, M. D.; Dick, G. J.; Wang, R. T.

    1999-01-01

    New radio science experiments, including a gravitational wave search and several atmospheric occultation studies, are planned for the Cassini Ka-band experiment. These experiments are made possible by reduced solar-induced phase fluctuations at the high-frequency (32 GHZ) of the radio link between the earth and the spacecraft. In order to match the improved link performance, a significant upgrade is under way to improve the frequency stability capabilities of NASA's Deep Space Network (DSN). Significant improvements are being undertaken in many areas, including antenna vibration and (wet) tropospheric calibration, in addition to frequency generation and distribution. We describe here the design and development of a system to provide a reference signal with the highest possible frequency stability for both long-term, short-term, and phase noise, at an antenna (DSS 25) that is remote from the frequency standards room at SPC-10 at the Goldstone site. The new technologies were developed in order to meet the very tight requirements. They are: 1) a Stabilized Fiber-Optic Distribution Assembly (SFODA) that includes active compensation of thermal variations to transfer long-term stability over 16 km of ordinary fiber-optic cable, and 2) a Compensated Sapphire Oscillator (CSO) that provides short-term performance in a cryocooled sapphire oscillator with ultra-high short-term stability and low phase noise.

  2. Same sign dimuon search for heavy majorana mass neutrinos at the CMS experiment at CERN and design studies of a quartz plate calorimeter prototype

    CERN Document Server

    Clarida, Warren James

    2012-01-01

    This paper consists of two studies: the results of a search for heavy Majorana neutrinos (N) using an event signature defined by two like-sign charged muons and two jets, and the results from studies of a prototype quartz plate calorimeter. The data in the Majorana search correspond to an integrated luminosity of 5.0 fb$^{−1}$ of pp collisions at a centre-of-mass energy of 7 TeV collected with the CMS detector at the Large Hadron Collider. No excess of events are observed beyond the expected standard model background and therefore upper limits are set on the square of the mixing element, $|V_{\\mu N} |$as a function of Majorana neutrino mass. These are the first direct upper limits on the heavy Majorana-neutrino mixing for m$_N$ > 90 GeV . The second part of this thesis is the results of performance tests of a 20-layer quartz plate calorimeter prototype. The calorimeter prototype was tested at the CERN H2 area in hadronic and electromagnetic configurations, at various en ergies of pion and electron beams. Th...

  3. Same sign dimuon search for heavy majorana mass neutrinos at the CMS experiment at CERN and design studies of a quartz plate calorimeter prototype

    Energy Technology Data Exchange (ETDEWEB)

    Clarida, Warren James [Univ. of Iowa, Iowa City, IA (United States)

    2012-12-01

    This paper consists of two studies: the results of a search for heavy Majorana neutrinos (N) using an event signature defined by two like-sign charged muons and two jets, and the results from studies of a prototype quartz plate calorimeter. The data in the Majorana search correspond to an integrated luminosity of 5.0 fb$^{−1}$ of pp collisions at a centre-of-mass energy of 7 TeV collected with the CMS detector at the Large Hadron Collider. No excess of events are observed beyond the expected standard model background and therefore upper limits are set on the square of the mixing element, $|V_{\\mu N} |$as a function of Majorana neutrino mass. These are the first direct upper limits on the heavy Majorana-neutrino mixing for m$_N$ > 90 GeV . The second part of this thesis is the results of performance tests of a 20-layer quartz plate calorimeter prototype. The calorimeter prototype was tested at the CERN H2 area in hadronic and electromagnetic configurations, at various en ergies of pion and electron beams. The beam test and simulation results of this prototype are reported.

  4. Dynamic Response of Three-Layered Annular Plate with Imperfections

    Directory of Open Access Journals (Sweden)

    Pawlus Dorota

    2015-02-01

    Full Text Available This paper presents the imperfection sensitivity of annular plate with three-layered structure. The plate composed of thin elastic facings and a thicker elastic core is loaded in facing plane. The classical issue of a three-layered plate was solved for dynamic deflection problem using the approximation methods: orthogonalization and finite difference. The solution includes the axisymmetric and asymmetric plate modes of the dynamic stability loss. The evaluation of the rate of plate sensitivity to imperfection of plate preliminary geometry has been enriched by the analysis of plate models built of finite elements. The ABAQUS program has been used. The numerous calculation results in the form of deflection characteristics, buckling modes, values of critical parameters create the view of response of dynamic plate structure with different rate of imperfection and linear in time loading growth, too.

  5. Comparison of CMS Resistive Plate Chambers performance during LHC RUN-1 and RUN-2

    CERN Document Server

    Shah, Mehar Ali

    2016-01-01

    The Resistive Plate Chambers detector system at the CMS experiment at the LHC provides robustness and redundancy to the muon trigger. A total of 1056 double-gap chambers cover the pseudo-rapidity region < 1.6. The main detector parameters and environmental conditions are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC with center-of-mass energy of 13 TeV. First results of overall detector stability with 2015 data and comparisons with data from the LHC RUN-1 period at 8 TeV are presented.

  6. Comparison of CMS Resistive Plate Chambers performance during LHC RUN-1 and RUN-2

    CERN Document Server

    Shah, Mehar Ali

    2016-01-01

    The Resistive Plate Chambers detector system at the CMS experiment at the LHC provides robustness and redundancy to the muon trigger. A total of 1056 double-gap chambers cover the pseudo-rapidity region lt 1.6. The main detector parameters and environmental conditions are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC with center-of-mass energy of 13 TeV. First results of overall detector stability with 2015 data and comparisons with data from the LHC RUN-1 period at 8 TeV are presented.

  7. The impact of heating the breakdown bubble on the global mode of a swirling jet: Experiments and linear stability analysis

    Science.gov (United States)

    Rukes, Lothar; Sieber, Moritz; Paschereit, C. Oliver; Oberleithner, Kilian

    2016-10-01

    This study investigates the dynamics of non-isothermal swirling jets undergoing vortex breakdown, with an emphasis on helical coherent structures. It is proposed that the dominant helical coherent structure can be suppressed by heating the recirculation bubble. This proposition is assessed with stereo Particle Image Velocimetry (PIV) measurements of the breakdown region of isothermal and heated swirling jets. The coherent kinetic energy of the dominant helical structure was derived from PIV snapshots via proper orthogonal decomposition. For one set of experimental parameters, mild heating is found to increase the energy content of the dominant helical mode. Strong heating leads to a reduction by 30% of the coherent structures energy. For a second set of experimental parameters, no alteration of the dominant coherent structure is detectable. Local linear stability analysis of the time-averaged velocity fields shows that the key difference between the two configurations is the density ratio at the respective wavemaker location. A density ratio of approximately 0.8 is found to correlate to a suppression of the global mode in the experiments. A parametric study with model density and velocity profiles indicates the most important parameters that govern the local absolute growth rate: the density ratio and the relative position of the density profiles and the inner shear layer.

  8. Create Your Plate

    Medline Plus

    Full Text Available ... steps to get started: Using your dinner plate, put a line down the middle of the plate. ... vegetables . Now in one of the small sections, put grains and starchy foods. See this list of ...

  9. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... 2016 Articles from Diabetes Forecast® magazine: wcie-meal-planning, In this section Food Planning Meals Diabetes Meal ...

  10. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal ... Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook ...

  11. Food guide plate

    Science.gov (United States)

    ... chips or cookies. VEGETABLES: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Vegetables can be raw, fresh, ... as a snack. FRUITS: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Fruits can be fresh, canned, ...

  12. Growth Plate Fractures

    Science.gov (United States)

    ... the most widely used by doctors is the Salter-Harris system, described below. Type I Fractures These ... incidence of growth plate fractures peaks in adolescence. Salter-Harris classification of growth plate fractures. AAOS does ...

  13. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  14. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  15. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets you still choose the foods you want, but changes the portion sizes so you are getting larger ...

  16. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... Sleeve Custom jerseys for your Tour de Cure team benefits the cause. Ask the Experts: Learn to ...

  17. Accelerated plate tectonics.

    Science.gov (United States)

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  18. Biomechanical comparison of orthogonal versus parallel double plating systems in intraarticular distal humerus fractures

    Directory of Open Access Journals (Sweden)

    Ata C. Atalar

    2017-01-01

    Conclusion: Our study showed that both plating systems had similar biomechanical stabilities when anatomic plates with distal locking screws were used in intraarticular distal humerus fractures in artificial humerus models.

  19. Geometry of the Cocos Plate Under North American Plate

    Science.gov (United States)

    Perez-Campos, X.

    2015-12-01

    The Cocos plate subducts under the North American plate with a complex geometry, and previous seismicity studies revealed some of this complexity. However, details of the geometry and the depth that the plate penetrates werelargely unknown. Since 2004, temporary experiments and the expansion of the permanent network of the Servicio Sismológico Nacional (SSN, Mexican National Seismological Service) have improved resolution of the plate geometry and have helped to map its descent into the upper mantle. Going from northwest to southeast, the Cocos plate appears to be fragmenting into north and south segments. The north segment subducts with an angle of ~30º and the south with an angle of ~10-15º. The transition is smooth near the trench and progresses to a tear at depth; this coincides with the projection of the Orozco Fracture Zone to depth. Also, this transition marks the limit of the presence to the south of an ultra slow velocity layer (USL) on top of the slab.South of this transition, the Cocos plate subducts horizontally , underplating the North American plate for a distance of ~140 to ~300 km from the trench. Along this horizontal region, silent slow events (SSE) and tectonic tremor (TT) have been observed. At a distance of 300 km from the trench (beneath central Mexico), the plate dives into the mantle with an angle of 76º to a depth of 500 km. This geometry changes abruptly to the south, marking the eastern limit of the USL. This change seems to be also characterized by a tear on the slab. Finally to the south, the Cocos plate subducts with a constant angle of 26º. This presentation summarizes the work of many contributors including A. Arciniega-Ceballos, M. Brudzinski, E. Cabral-Cano, T. Chen, R. Clayton,F. Cordoba-Montiel,P. Davis,S. Dougherty,F. Green, M. Gurnis, D. V. Helmberger, A. Husker,A. Iglesias, Y. Kim, V. Manea, D. Melgar, M. Rodríguez-Domínguez,S. K. Singh, T.-R. A. Song, C. M. Valdés-González, D. Valencia-Cabrera

  20. Create Your Plate

    Medline Plus

    Full Text Available ... Reset Plate Share Create Your Plate ! Share: Seven Simple Steps to Create Your Plate It's simple and effective for both managing diabetes and losing ... en.html Have Type 2 Diabetes? Our free program will help you live well. More from diabetes. ...

  1. Obliquity along plate boundaries

    Science.gov (United States)

    Philippon, Mélody; Corti, Giacomo

    2016-12-01

    Most of the plate boundaries are activated obliquely with respect to the direction of far field stresses, as roughly only 8% of the plate boundaries total length shows a very low obliquity (ranging from 0 to 10°, sub-orthogonal to the plate displacement). The obliquity along plate boundaries is controlled by (i) lateral rheological variations within the lithosphere and (ii) consistency with the global plate circuit. Indeed, plate tectonics and magmatism drive rheological changes within the lithosphere and consequently influence strain localization. Geodynamical evolution controls large-scale mantle convection and plate formation, consumption, and re-organization, thus triggering plate kinematics variations, and the adjustment and re-orientation of far field stresses. These geological processes may thus result in plate boundaries that are not perpendicular but oblique to the direction of far field stresses. This paper reviews the global patterns of obliquity along plate boundaries. Using GPlate, we provide a statistical analysis of present-day obliquity along plate boundaries. Within this framework, by comparing natural examples and geological models, we discuss deformation patterns and kinematics recorded along oblique plate boundaries.

  2. [Chest Wall Reconstruction Using Titanium Plates Sandwiched Between Sheets after Resection of Chest Wall Chondrosarcoma].

    Science.gov (United States)

    Endoh, Makoto; Oizumi, Hiroyuki; Kato, Hirohisa; Suzuki, Jun; Watarai, Hikaru; Hamada, Akira; Suzuki, Katsuyuki; Takahashi, Ai; Nakahashi, Kenta; Sugawara, Masato; Tsuchiya, Takashi; Sadahiro, Mitsuaki

    2016-07-01

    Extensive chest wall resection carries the risk of difficult reconstruction and surgical complications. We report our experience on chest wall reconstruction using titanium plates for a wide thoracic defect after tumor resection. A 74-year-old man was diagnosed with chondrosarcoma of the 6th rib on the right. He needed extensive chest wall resection because of skip lesions on 4th rib noted on operative inspection, leaving a defect measuring 33 × 20 cm. Reconstruction using 5 transverse titanium plates sandwiched between an expanded polytetrafluoroethylene patch and a polypropylene mesh sheet stabilized the chest wall. This reconstruction allowed successful separation from ventilatory support after operation. The postoperative course was uneventful, and he was discharged on postoperative day 20. The advantages of this form of reconstruction over conventional prostheses are rigidity, and stability and usability.

  3. Angular shear plate

    Science.gov (United States)

    Ruda, Mitchell C [Tucson, AZ; Greynolds, Alan W [Tucson, AZ; Stuhlinger, Tilman W [Tucson, AZ

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  4. Locking, mass flux and topographic response at convergent plate boundaries - the Chilean case

    Science.gov (United States)

    Oncken, Onno

    2016-04-01

    On the long term, convergent plate boundaries have been shown to be controlled by either accretion/underplating or by subduction erosion. Vertical surface motion is coupled to convergence rate - typically with an uplift rate of the coastal area ranging from 0 to +50% of convergence rate in accretive systems, and -20 to +30% in erosive systems. Vertical kinematics, however, are not necessarily linked to horizontal strain mode, i.e. upper plate shortening or extension, in a simple way. This range of kinematic behaviors - as well as their acceleration where forearcs collide with oceanic ridges/plateau - is well expressed along the Chilean plate margin. Towards the short end of the time scale, deformation appears to exhibit a close correlation with the frictional properties and geodetic locking at the plate interface. Corroborating analogue experiments of strain accumulation during multiple earthquake cycles, forearc deformation and uplift focus above the downdip and updip end of seismic coupling and slip and are each related to a particular stage of the seismic cycle, but with opposite trends for both domains. Similarly, barriers separating locked domains along strike appear to accumulate most upper plate faulting interseismically. Hence, locking patters are reflected in topography. From the long-term memory contained in the forearc topography the relief of the Chilean forearc seems to reflect long term stability of the observed heterogeneity of locking at the plate interface. This has fundamental implications for spatial and temporal distribution of seismic hazard. Finally, the nature of locking at the plate interface controlling the above kinematic behavior appears to be strongly controlled by the degree of fluid overpressuring at the plate interface suggesting that the hydraulic system at the interface takes a key role for the forearc response.

  5. Genetic variation, phenotypic stability, and repeatability of drought response in European larch throughout 50 years in a common garden experiment.

    Science.gov (United States)

    George, Jan-Peter; Grabner, Michael; Karanitsch-Ackerl, Sandra; Mayer, Konrad; Weißenbacher, Lambert; Schueler, Silvio; Mäkelä, Annikki

    2017-01-31

    Assessing intra-specific variation in drought stress response is required to mitigate the consequences of climate change on forest ecosystems. Previous studies suggest that European larch (Larix decidua Mill.), an important European conifer in mountainous and alpine forests, is highly vulnerable to drought. In light of this, we estimated the genetic variation in drought sensitivity and its degree of genetic determination in a 50-year-old common garden experiment in the drought-prone northeastern Austria. Tree ring data from larch provenances originating from across the species' natural range were used to estimate the drought reaction in four consecutive drought events (1977, 1981, 1990–1994, and 2003) with extremely low standardized precipitation- and evapotranspiration-index values that affected growth in all provenances. We found significant differences among provenances across the four drought periods for the trees’ capacity to withstand drought (resistance) and for their capacity to reach pre-drought growth levels after drought (resilience). Provenances from the species' northern distribution limit in the Polish lowlands were found to be more drought resistant and showed higher stability across all drought periods than provenances from mountainous habitats at the southern fringe. The degree of genetic determination, as estimated by the repeatability, ranged up to 0.39, but significantly differed among provenances, indicating varying degrees of natural selection at the provenance origin. Generally, the relationship between the provenances’ source climate and drought behavior was weak, suggesting that the contrasting patterns of drought response are a result of both genetic divergence out of different refugial lineages and local adaptation to summer or winter drought conditions. Our analysis suggests that European larch posseses high genetic variation among and within provenances that can be used for assisted migration and breeding programs.

  6. Combining long term field experiments and nanoscale analysis to enhance process understanding of root litter stabilization by mineral interactions

    Science.gov (United States)

    Chabbi, Abad; Baumann, Karen; Remusat, Laurent; Barre, Pierre; Dignac, Marie-France; Rumpel, Cornelia

    2015-04-01

    Mineral interaction may affect the stabilisation of root litter directly or indirectly after microbial decomposition and transformation. The importance of both processes may vary within the soil profile. In this study we studied C stabilisation of isotopically labelled root litter (13C and 15N), which was incubated during 3 year in the field at different soil depth. Samples from this field experiment were recovered and subjected to nanoscale analyses in order to elucidate mineral interactions occurring in different parts of the soil profile. Our results showed enrichment of mineral associated organic matter in subsoil horizons. However, material derived from new plant litter may be stabilised at similar rates in top- and subsoil horizons. N-containing compounds are enriched in the mineral associated fraction of subsoil horizons, indicating enrichment of microbial derived material with depth. Nano scale analyses showed that indeed plant-derived material may be associated with metal oxides in topsoil horizons, whereas the mineral associated organic matter in subsoil horizons may consist of microbial cells. Interestingly, in contrast to short term laboratory analysis, decoupling of C and N through stabilisation with soil minerals was observed during this long term field experiment. Our results indicate that the nature of OM stabilised by mineral interactions is depth specific. Therefore, we suggest, that plant derived lignocellulosic material may be preserved by mineral interactions in topsoil given its incomplete degradation, thereby leading to the formation of functional groups and favouring adsorption to soil minerals. This is consistent with the higher state of lignin-degradation observed in topsoil horizons as compared to subsoil. At depth, where microorganisms are most likely energy limited, degradation of fresh plant litter may be complete, thereby diminishing the formation of lignocellulosic compounds capable of sorption onto metal oxides. As a result

  7. [Toxicological evaluation of nanosized colloidal silver, stabilized with polyvinylpyrrolidone, in 92-day experiment on rats. II. Internal organs morphology].

    Science.gov (United States)

    Zaytseva, N V; Zemlyanova, M A; Zvezdin, V N; Dovbysh, A A; Gmoshinsky, I V; Khotimchenko, S A; Akafieva, T I

    2016-01-01

    The aim of the study was to evaluate the safe doses of commercially available nanosized colloidal silver (NCS), stabilized with polyvinilpirrolidone (PVP, food additive E1201) when administered in gastrointestinal tract of rats in the 92-day experiment in terms of the morphological changes in the internals of animals. The sample studied contained non-aggregated nanoparticles (NPs) of silver belonging to size fractions with a diameter of less than 5 nm, 10-20 nm or 50-80 nm. 80% of NPs were inside the range of hydrodynamic diameters 10.6-61.8 nm. The preparation of NCS was administered to growing male Wistar rats. (initial body weight 80 ± 10 g) for 1 month by intragastric gavage and then consumed with food at doses of 0.1, 1.0 and 10 mg/kg of body weight based on silver. The control animals received water or vehicle of nanomaterial--water solution of PVP. After withdrawal of animals from the experiment by exsanguination under ether anesthesia organs (liver, spleen, kidney, ileum) were isolated and their slides were prepared by standard methods following 'by staining with hematoxylin-eosin. Analysis was performed in light optical microscope equipped with a digital camera at a magnification from 1 x 100 to 1 x 1000. It was shown that the experimental animals treated with the NCS developed series of morphological changes in the tissues of the internal organs (liver, spleen and kidney) with the elevation of the range and severity of structural changes with increasing doses of silver. The most sensitive target of NCS action was apparently liver, which has already shown at a dose of 0.1 mg of silver NP/kg of body weight marked eosinophilic infiltration of portal tracts, which was accompanied at doses of 1.0 and 10.0 mg/kg by the emergence of medium and large-drop fat vacuoles in the cytoplasm of hepatocytes, swelling and lympho-macrophage. infiltration of the portal tracts. Detectable changes can be regarded as symptoms of inflammation of hepatocytes, at least, at a

  8. 两种不同强塑性薄钢板抗弹性能的试验和数值模拟%Experiment and Numerical Simulation on Ballistic Performance of Two Thin Steel Plates With Different Strength and Ductility

    Institute of Scientific and Technical Information of China (English)

    肖红亮; 时捷; 曹文全; 雍岐龙; 董瀚

    2012-01-01

    51B-type 7.62mm pistol bullets were fired at thin steel plates with different strength and ductility. And the numerical simulation for the experiments was carried on by ANSYS/LS-DYNA too. The macro-appearance in the process of testing and numerical simulation were compared, such as the impact craters, bulge height and residual projectile size. At last, combined with the energy absorption of the steel plate and the bullet, the influence of the strength and ductility on ballistic performance was analyzed. The results show that: two tested steel plates almost have the same ballistic performance against the 5113 type 7.62 mm pistol bullets, although the very different tensile strength and elongation they have. The numerical simulation result is consistent with the experiment, and it can re- flect the process of the bullets impact target rightly. To the higher strength steel plate, energy absorption by making the projectile deformation is greater than the lower strength one, and to the higher ductility steel plate, energy absorption though its own deformation is larger than the lower ductility one. Thus, the result of two tested steel plates almost have the same ballistic performance is explained.%利用51B式7.62mm手枪弹对不同强度和塑性的薄钢板进行枪击试验,采用ANSYS/LS-DYNA软件对试验过程进行数值模拟,对试验和数值模拟过程的钢板破坏形貌、背凸高度、残余弹丸长度等宏观形貌进行比较。结合抗弹过程中弹丸和钢板消耗的能量,分析了强度和塑性对钢板抗弹性能的影响。结果表明:尽管两种钢板的抗拉强度和断后伸长率差异较大,但其抗51B式7.62mm手枪弹性能相当。试验和数值模拟结果吻合较好,模拟方法能够正确地反映弹丸冲击靶板过程。因较高强度钢板使弹丸变形消耗的能量大于较低强度钢板,塑性较好钢板本身变形消耗的能量大于较低塑性钢板,从而解释了两种钢板抗弹性能相当的试验结果。

  9. 铝板中Lamb波检测的实验研究%Experiment investigations of Lamb waves in an aluminum plate

    Institute of Scientific and Technical Information of China (English)

    陈军; 李志浩; 林莉; 侯云霞; 马清杰

    2011-01-01

    Lamb波在传播过程中具有频散及多模态特性,若相关参数选择不当,会导致在实际应用中信号相互叠加而无法识别.本文基于Lamb波的频散曲线是其频散方程实数解分布的特点,采用二分法绘制了铝板中Lamb波的频散曲线、波结构曲线和入射角曲线.根据曲线选择SO模态的Lamb波对1mm厚铝板中不同类型的缺陷进行检测.实验结果表明,SO模态的Lamb波对裂纹型缺陷和贯穿型缺陷十分敏感,但对于裂纹型缺陷,其幅值变化并不与缺陷大小成线性关系,并且SO模态Lamb波的声场指向性十分集中,在偏离声束轴线时无法检测到缺陷.%Lamb waves have dispersive and multi-modal characteristics during its propagation.In actual applications, the multi-modal signals overlap and the useful modes can not be identified if relevant parameters are not properly selected.The dispersion, wave structure and incident angle curves of Lamb waves in an aluminum plate are drawn with dichotomy based on the characteristics that the Lamb wave dispersion curve is the distribution of real solutions of a Lamb wave dispersion equation.SO mode Lamb wave is selected to detect the flaws with different types in 1 mm thick aluminum plate based on the dispersion curve.The results show that SO mode Lamb wave is very sensitive to cracks and through defects;however, the amplitude of SO mode don't change linearly with the defect size.Meanwhile, the sound field directivity of SO mode Lamb wave is very concentrated, and the defects deviated from the beam axis can not be detected.

  10. Advances and Trends in Plate Buckling Research.

    Science.gov (United States)

    1982-12-01

    Hydrostatic State of In- Plane Stress. Instituto de Mecanica Aplicada No. 79-21 (Puerto Belgrano, Argentina), June 1979, 10 pp. (to be published). 38. Leissa...and Elastic Stability of Circular Plates With Thickness Varying in a Bilinear Fashion. Instituto de Mecanica Aplicada No. 81-23 (Puerto Belgrano

  11. Linking computation and experiments to study the role of charge-charge interactions in protein folding and stability

    Science.gov (United States)

    Makhatadze, George I.

    2017-02-01

    Over the past two decades there has been an increase in appreciation for the role of surface charge-charge interactions in protein folding and stability. The perception shifted from the belief that charge-charge interactions are not important for protein folding and stability to the near quantitative understanding of how these interactions shape the folding energy landscape. This led to the ability of computational approaches to rationally redesign surface charge-charge interactions to modulate thermodynamic properties of proteins. Here we summarize our progress in understanding the role of charge-charge interactions for protein stability using examples drawn from my own laboratory and touch upon unanswered questions.

  12. Ray transfer matrix for a spiral phase plate.

    Science.gov (United States)

    Eggleston, M; Godat, T; Munro, E; Alonso, M A; Shi, H; Bhattacharya, M

    2013-12-01

    We present a ray transfer matrix for a spiral phase plate. Using this matrix we determine the stability of an optical resonator made of two spiral phase plates and trace stable ray orbits in the resonator. Our results should be relevant to laser physics, optical micromanipulation, quantum information, and optomechanics.

  13. Linear and nonlinear buckling analysis of a locally stretched plate

    Energy Technology Data Exchange (ETDEWEB)

    Kilardj, Madina; Ikhenzzen, Ghania [University of Sciences and Technology Houari Boumediene (U.S.T.H.B), Bab Ezzouar, Algiers (Algeria); Merssager, Tanguy; Kanit, Toufik [Laboratoire de Mecanique de Lille Universite Lille 1, Cite ScientifiqueVilleneuve d' Ascq cedex (France)

    2016-08-15

    Uniformly stretched thin plates do not buckle unless they are in special boundary conditions. However, buckling commonly occurs around discontinuities, such as cracks, cuts, narrow slits, holes, and different openings, of such plates. This study aims to show that buckling can also occur in thin plates that contain no defect or singularity when the stretching is local. This specific stability problem is analyzed with the finite element method. A brief literature review on stretched plates is presented. Linear and nonlinear buckling stress analyses are conducted for a partially stretched rectangular plate, and various load cases are considered to investigate the influence of the partial loading expanse on the critical tensile buckling load. Results are summarized in iso-stress areas, tables and graphs. Local stretching on one end of the plate induces buckling in the thin plate even without geometrical imperfection.

  14. Episodic plate tectonics on Venus

    Science.gov (United States)

    Turcotte, Donald

    1992-01-01

    Studies of impact craters on Venus from the Magellan images have placed important constraints on surface volcanism. Some 840 impact craters have been identified with diameters ranging from 2 to 280 km. Correlations of this impact flux with craters on the Moon, Earth, and Mars indicate a mean surface age of 0.5 +/- 0.3 Ga. Another important observation is that 52 percent of the craters are slightly fractured and only 4.5 percent are embayed by lava flows. These observations led researchers to hypothesize that a pervasive resurfacing event occurred about 500 m.y. ago and that relatively little surface volcanism has occurred since. Other researchers have pointed out that a global resurfacing event that ceased about 500 MYBP is consistent with the results given by a recent study. These authors carried out a series of numerical calculations of mantle convection in Venus yielding thermal evolution results. Their model considered crustal recycling and gave rapid planetary cooling. They, in fact, suggested that prior to 500 MYBP plate tectonics was active in Venus and since 500 MYBP the lithosphere has stabilized and only hot-spot volcanism has reached the surface. We propose an alternative hypothesis for the inferred cessation of surface volcanism on Venus. We hypothesize that plate tectonics on Venus is episodic. Periods of rapid plate tectonics result in high rates of subduction that cool the interior resulting in more sluggish mantle convection.

  15. 不同类型肱骨骨折钢板内固定后稳定性分析%Stability of different types of humeral fractures after internal fixation with plate

    Institute of Scientific and Technical Information of China (English)

    宋景仑; 张奉琪; 王鹏程

    2012-01-01

    目的 用生物力学实验方法分析横断骨折、短斜骨折和粉碎骨折三种情况下肱骨骨折钢板内固定术后稳定性.方法 选取骨密度值相近的肱骨干标本30个,分三组分别制作成横断骨折、短斜骨折和粉碎骨折.将标本水平位放置于生物力学机,于骨折处垂直向下载荷,记录肱骨力-外翻位移.将标本竖直固定于生物力学机,肱骨头侧向上,给肱骨外旋负荷,记录肱骨扭矩-外旋转角.结果 肱骨横断骨折、短斜骨折和粉碎骨折三组的外翻位移及外旋角依次增大,经统计学比较各组间有统计学差异(1-a=95%,P<0.05)结论 肱骨骨折钢板固定时,横断骨折、短斜骨折和粉碎骨折的稳定性依次降低,粉碎骨折术后功能锻炼要适度,必要时辅以适当外固定.%Objective To analyze the stability after internal fixation for transverse fracture,short oblique fracture and comminuted fractures by biomechanical experiment. Methods Thirty specimens of humerus shaft with similar bone density were selected to make the models of transverse fracture, short oblique fracture and comminuted fracture. The humerus force-eversion displacement was recorded while the specimen was imposed vertically by the machine. The humeral torque-external rotation angle was recorded while the humerus was externally rotated on the machine. Results The eversion displacement and external rotation angle increased gradually for the transverse fractures, short oblique fractures comminuted fractures in turn, and there was statistically different among three groups ( P < 0.05 ). Conclusion The internal fixation stability for transverse fracture, short oblique fractures and comminuted fracture decreases gradually. The postoperative functional exercise should be proper for comminuted fractures,and can be supplemented by the appropriate external fixation if necessary.

  16. Generalized Fibonacci zone plates

    CERN Document Server

    Ke, Jie; Zhu, Jianqiang

    2015-01-01

    We propose a family of zone plates which are produced by the generalized Fibonacci sequences and their axial focusing properties are analyzed in detail. Compared with traditional Fresnel zone plates, the generalized Fibonacci zone plates present two axial foci with equal intensity. Besides, we propose an approach to adjust the axial locations of the two foci by means of different optical path difference, and further give the deterministic ratio of the two focal distances which attributes to their own generalized Fibonacci sequences. The generalized Fibonacci zone plates may allow for new applications in micro and nanophotonics.

  17. Vortex Formation, Shedding and Energy Harvesting from a Cyber-Physical Pitching Flat Plate

    Science.gov (United States)

    Onoue, Kyohei; Breuer, Kenneth

    2014-11-01

    We examine the dynamics and energy harvesting capabilities of an elastically mounted flat plate undergoing large amplitude limit cycle oscillations in a uniform flow. All experiments are performed using a cyber-physical system, wherein the structural inertia, stiffness and damping are numerically simulated using a position-following feedback algorithm. The cyber-physical system also allows for implementation of nonlinear spring and damping coefficients, which control the plate dynamics and subsequent energy harvesting characteristics. Analysis of the plate kinematics and the fluid flow over the plate and in the wake (measured using PIV) are used to understand the interplay between structural motion and vortex formation at the sharp leading and trailing edges of the plate. By varying the structural properties of the system we systematically analyze the formation, strength, stability and separation of the leading edge vortex, as well as the dependence on kinematic parameters and Reynolds number. Connections to previous results on vortex formation time and bluff body aerodynamics are discussed. This research is funded by the Air Force Office of Scientific Research (AFOSR).

  18. Effect of Slurry Composition on Plate Weight in Ceramic Shell Investment Casting

    Science.gov (United States)

    Sidhu, Balwinder Singh; Kumar, Pradeep; Mishra, B. K.

    2008-08-01

    This paper deals with the study of the effect of primary slurry parameters on the plate weight (ceramic retention test) in ceramic shell investment casting process. Four controllable factors of the zircon flour and fused-silica powder based slurries were studied at three levels each by Taguchi’s parametric approach and single-response optimization of plate weight was conducted to identify the main factors controlling its stability. Variations in coating thickness with plate weight were calculated for each slurry and ceramic shell moulds were made on wax plate using primary slurry and coarse fused-silica sand as stucco. The Scanning Electronic Microscopy (SEM) technique has been used to study the surface morphology of zircon flour and fused silca powder particles as well as primary coating (shell surface). X-ray Diffraction (XRD) analysis was done to identify the various phases present in the ceramic slurry coating. Optical profilometer has been used to measure the surface roughness of the shells. The result reveals that the surface condition of shell can be improved by increasing the plate weight, corresponding to higher filler loading in the slurry. Confirmation experiments were conducted at an optimal condition showed that the surface quality of the ceramic shell mould were improved significantly. Castings were produced using Al-7%Si alloy in recommended parameters through ceramic shell investment casting process. Surface roughness of the produced casting were measured and presented in this paper.

  19. Effect of roughness on the stability of boundary layers

    Science.gov (United States)

    Nayfeh, Ali H.; Ragab, Saad A.; Al-Maaitah, Ayman

    1987-01-01

    An analysis is conducted on the effect of imperfections consisting of humps and dips on the stability of incompressible flows over flat plates. The mean flow is calculated using interacting boundary layers. Linear quasiparallel spatial stability is used to calculate the growth rates and mode shapes of two-dimensional disturbances. Then, the amplification factor is computed. A search for the most dangerous frequency is conducted based on an amplification factor of 9 in the shortest distance. Correlations are made with the transition experiment of Walker and Greening using the e sup 9 method.

  20. Mechanical design of multiple zone plates precision alignment apparatus for hard X-ray focusing in twenty-nanometer scale

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Deming; Liu, Jie; Gleber, Sophie C.; Vila-Comamala, Joan; Lai, Barry; Maser, Jorg M.; Roehrig, Christian; Wojcik, Michael J.; Vogt, Franz Stefan

    2017-04-04

    An enhanced mechanical design of multiple zone plates precision alignment apparatus for hard x-ray focusing in a twenty-nanometer scale is provided. The precision alignment apparatus includes a zone plate alignment base frame; a plurality of zone plates; and a plurality of zone plate holders, each said zone plate holder for mounting and aligning a respective zone plate for hard x-ray focusing. At least one respective positioning stage drives and positions each respective zone plate holder. Each respective positioning stage is mounted on the zone plate alignment base frame. A respective linkage component connects each respective positioning stage and the respective zone plate holder. The zone plate alignment base frame, each zone plate holder and each linkage component is formed of a selected material for providing thermal expansion stability and positioning stability for the precision alignment apparatus.

  1. Mechanical design of multiple zone plates precision alignment apparatus for hard X-ray focusing in twenty-nanometer scale

    Science.gov (United States)

    Shu, Deming; Liu, Jie; Gleber, Sophie C.; Vila-Comamala, Joan; Lai, Barry; Maser, Jorg M.; Roehrig, Christian; Wojcik, Michael J.; Vogt, Franz Stefan

    2017-04-04

    An enhanced mechanical design of multiple zone plates precision alignment apparatus for hard x-ray focusing in a twenty-nanometer scale is provided. The precision alignment apparatus includes a zone plate alignment base frame; a plurality of zone plates; and a plurality of zone plate holders, each said zone plate holder for mounting and aligning a respective zone plate for hard x-ray focusing. At least one respective positioning stage drives and positions each respective zone plate holder. Each respective positioning stage is mounted on the zone plate alignment base frame. A respective linkage component connects each respective positioning stage and the respective zone plate holder. The zone plate alignment base frame, each zone plate holder and each linkage component is formed of a selected material for providing thermal expansion stability and positioning stability for the precision alignment apparatus.

  2. Liquid repellency by a moving plate

    Science.gov (United States)

    Bouillant, Ambre; Anais Gauthier Team; David Quere Team; Christophe Clanet Team

    2016-11-01

    Moving solids can repel impacting drops, owing to their motion. Provided the solid velocity is larger than a threshold value, air entrained at the vicinity of the moving plate prevents the drop from wetting, and makes it bounce. In addition, the rebound is oblique, which enhances the evacuation of liquid. We discuss experiments and models on this theme, and extend them to case of small droplets (such as formed in a spray) found to be even more efficiently repelled by the moving plate.

  3. Pilot Production of Large Area Microchannel Plates and Picosecond Photodetectors

    Science.gov (United States)

    Minot, M.; Adams, B.; Abiles, M.; Bond, J.; Craven, C.; Cremer, T.; Foley, M.; Lyashenko, A.; Popecki, M.; Stochaj, M.; Worstell, W.; Elam, J.; Mane, A.; Siegmund, O.; Ertley, C.

    2016-09-01

    Pilot production performance is reported for large area atomic layer deposition (ALD) coated microchannel plates (ALD-GCA-MCPs) and for Large Area Picosecond Photodetectors (LAPPD™) which incorporate them. "Hollowcore" glass capillary array (GCA) substrates are coated with ALD resistive and emissive layers to form the ALDGCA- MCPs, an approach that facilitates independent selection of glass substrates that are mechanically stronger and that have lower levels of radioactive alkali elements compared to conventional MCP lead glass, reducing background noise[1,2,3,4]. ALD-GCA-MCPs have competitive gain ( 104 each or 107 for a chevron pair ), enhanced lifetime and gain stability (7 C cm-2 of charge extraction), reduced background levels (0.028 events cm-2 sec-1) and low gamma-ray detection efficiency. They can be fabricated in large area (20cm X 20 cm) planar and curved formats suitable for use in high radiation environment applications, including astronomy, space instrumentation, and remote night time sensing. The LAPPD™ photodetector incorporates these ALD-GCA-MCPs in an all-glass hermetic package with top and bottom plates and sidewalls made of borosilicate float glass. Signals are generated by a bi-alkali Na2KSb photocathode, amplified with a stacked chevron pair of ALD-GCA-MCPs. Signals are collected on RF strip-line anodes integrated into to the bottom plates which exit the detector via pin-free hermetic seals under the side walls [5]. Tests show that LAPPDTMs have electron gains greater than 107, submillimeter spatial resolution for large (multiphoton) pulses and several mm for single photons, time resolution less than 50 picoseconds for single photons, predicted resolution less than 5 picoseconds for large pulses, high stability versus charge extraction[6], and good uniformity for applications including astrophysics, neutron detection, high energy physics Cherenkov light detection, and quantum-optical photon-correlation experiments.

  4. Model Experiment Study on Maintaining Stability of Frozen Subgrade by Collecting-Controlling Cold Energy%采控冷量维护冻土路基稳定的模拟试验研究

    Institute of Scientific and Technical Information of China (English)

    刘志强; 周国庆; 马巍; 牛富俊; 别小勇

    2004-01-01

    The stability of railway subgrade in permafrost regions is crucial to the safety of railway operation. In this paper, we first analyze the main factors influencing the stability of frozen subgrade. Then,we build an experimental equipment in which regulation-tubes are arranged axially in subgrade and arranged slantways at the foot of slopes, and make the model experiments on maintaining the stability of frozen subgrade by collecting- controlling cold energy. The experiments include two groups. One is maintaining the stability by collecting-controlling natural cold energy in winter, and another is maintaining the stability by collecting-controliing natural cold energy in winter and artificial cold energy in summer. Finally, we obtain the behavior of temperature fields in the subgrade during the experiments,which establishes basis for further study on the subgrade stability and on the feasibility of rushing to deal with freezing damage of frozen subgrade.

  5. Blue Willow Story Plates

    Science.gov (United States)

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  6. Create Your Plate

    Medline Plus

    Full Text Available ... In Memory In Honor Become a Member En Español Type 1 Type 2 About Us Online Community ... Page Text Size: A A A Listen En Español Create Your Plate Create Your Plate is a ...

  7. Create Your Plate

    Medline Plus

    Full Text Available ... Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning ... Planning Meals Diabetes Meal Plans and a Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets ...

  8. Problems experiences with the construction of cement and lime stabilized layers and working solutions for these problems

    CSIR Research Space (South Africa)

    Botha, PB

    2005-10-01

    Full Text Available . In recent times, major problems were experienced with chemical stabilization in the Southern African Region, particularly when CEM I 42,5 cement was used. The standard laboratory design procedure worked in the laboratory but did not perform in the field...

  9. Highly curved microchannel plates

    Science.gov (United States)

    Siegmund, O. H. W.; Cully, S.; Warren, J.; Gaines, G. A.; Priedhorsky, W.; Bloch, J.

    1990-01-01

    Several spherically curved microchannel plate (MCP) stack configurations were studied as part of an ongoing astrophysical detector development program, and as part of the development of the ALEXIS satellite payload. MCP pairs with surface radii of curvature as small as 7 cm, and diameters up to 46 mm have been evaluated. The experiments show that the gain (greater than 1.5 x 10 exp 7) and background characteristics (about 0.5 events/sq cm per sec) of highly curved MCP stacks are in general equivalent to the performance achieved with flat MCP stacks of similar configuration. However, gain variations across the curved MCP's due to variations in the channel length to diameter ratio are observed. The overall pulse height distribution of a highly curved surface MCP stack (greater than 50 percent FWHM) is thus broader than its flat counterpart (less than 30 percent). Preconditioning of curved MCP stacks gives comparable results to flat MCP stacks, but it also decreases the overall gain variations. Flat fields of curved MCP stacks have the same general characteristics as flat MCP stacks.

  10. Stability Study of the RERTR Fuel Microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Jian Gan; Dennis Keiser; Brandon Miller; Daniel Wachs

    2014-04-01

    The irradiation stability of the interaction phases at the interface of fuel and Al alloy matrix as well as the stability of the fission gas bubble superlattice is believed to be very important to the U-Mo fuel performance. In this paper the recent result from TEM characterization of Kr ion irradiated U-10Mo-5Zr alloy will be discussed. The focus will be on the phase stability of Mo2-Zr, a dominated second phase developed at the interface of U-10Mo and the Zr barrier in a monolithic fuel plate from fuel fabrication. The Kr ion irradiations were conducted at a temperature of 200 degrees C to an ion fluence of 2.0E+16 ions/cm2. To investigate the thermal stability of the fission gas bubble superlattice, a key microstructural feature in both irradiated dispersion U-7Mo fuel and monolithic U-10Mo fuel, a FIB-TEM sample of the irradiated U-10Mo fuel (3.53E+21 fission/cm3) was used for a TEM in-situ heating experiment. The preliminary result showed extraordinary thermal stability of the fission gas bubble superlattice. The implication of the TEM observation from these two experiments on the fuel microstructural evolution under irradiation will be discussed.

  11. Plate tectonics, habitability and life

    Science.gov (United States)

    Spohn, Tilman; Breuer, Doris

    2016-04-01

    The role of plate tectonics in defining habitability of terrestrial planets is being increasingly discussed (e.g., Elkins-Tanton, 2015). Plate tectonics is a significantly evolved concept with a large variety of aspects. In the present context, cycling of material between near surface and mantle reservoirs is most important. But increased heat transport through mixing of cold lithosphere with the deep interior and formation of continental crust may also matter. An alternative mechanism of material cycling between these reservoirs is hot-spot volcanism combined with crust delamination. Hot-spot volcanism will transport volatiles to the atmosphere while delamination will mix crust, possibly altered by sedimentation and chemical reactions, with the mantle. The mechanism works as long as the stagnant lithosphere plate has not grown thicker than the crust and as long as volcanic material is added onto the crust. Thermal evolution studies suggest that the mechanism could work for the first 1-2 Ga of planetary evolution. The efficiency of the mechanism is limited by the ratio of extrusive to intrusive volcanism, which is thought to be less than 0.25. Plate tectonics would certainly have an advantage by working even for more evolved planets. A simple, most-used concept of habitability requires the thermodynamic stability of liquid water on the surface of a planet. Cycling of CO2between the atmosphere, oceans and interior through subduction and surface volcanism is an important element of the carbonate-silicate cycle, a thermostat feedback cycle that will keep the atmosphere from entering into a runaway greenhouse. Calculations for a model Earth lacking plate tectonics but degassing CO2, N, and H2O to form a surface ocean and a secondary atmosphere (Tosi et al, 2016) suggest that liquid water can be maintained on the surface for 4.5Ga. The model planet would then qualify as habitable. It is conceivable that the CO2 buffering capability of its ocean together with silicate

  12. Stabilizing 3D in vivo intravital microscopy images with an iteratively refined soft-tissue model for immunology experiments.

    Science.gov (United States)

    Gómez-Conde, Iván; Caetano, Susana S; Tadokoro, Carlos E; Olivieri, David N

    2015-09-01

    We describe a set of new algorithms and a software tool, StabiTissue, for stabilizing in vivo intravital microscopy images that suffer from soft-tissue background movement. Because these images lack predetermined anchors and are dominated by noise, we use a pixel weighted image alignment together with a correction for nonlinear tissue deformations. We call this correction a poor man׳s diffeomorphic map since it ascertains the nonlinear regions of the image without resorting to a full integral equation method. To determine the quality of the image stabilization, we developed an ensemble sampling method that quantifies the coincidence between image pairs from randomly distributed image regions. We obtain global stabilization alignment through an iterative constrained simulated annealing optimization procedure. To show the accuracy of our algorithm with existing software, we measured the misalignment error rate in datasets taken from two different organs and compared the results to a similar and popular open-source solution. Present open-source stabilization software tools perform poorly because they do not treat the specific needs of the IV-2pM datasets with soft-tissue deformation, speckle noise, full 5D inter- and intra-stack motion error correction, and undefined anchors. In contrast, the results of our tests demonstrate that our method is more immune to noise and provides better performance for datasets' possessing nonlinear tissue deformations. As a practical application of our software, we show how our stabilization improves cell tracking, where the presence of background movement would degrade track information. We also provide a qualitative comparison of our software with other open-source libraries/applications. Our software is freely available at the open source repository http://sourceforge.net/projects/stabitissue/.

  13. 基于微热管阵列的平板太阳能热水器的性能试验%Performance experiments for flat plate solar water heater based on micro heat pipe array

    Institute of Scientific and Technical Information of China (English)

    邓月超; 全贞花; 赵耀华; 王林成; 叶三宝

    2013-01-01

      为了检验一种新型平板太阳能热水器的性能,该文对其核心部件—基于微热管阵列的集热器及其组成的热水器进行了热性能试验.集热器热性能测试结果表明,微热管阵列平板太阳能集热器瞬时效率的斜率为4.7,截距为0.80,分别优于国家标准要求值11.0%和22.3%.在满足测试要求的天气情况下,对微热管阵列平板太阳能热水器进行的多次热性能测试结果表明,热水器的日有效得热量均高于国家标准要求值,日平均集热效率均高于60%.同时,该热水器具有承压能力强、无炸裂、轻巧、成本低、无需焊接、抗冻性能好、易于建筑一体化等优势.基于微热管阵列的平板太阳能热水器由于性能优异,并能克服现有太阳能热水器的缺点,具有广阔的应用前景.%A novel flat plate solar water heater based on the micro heat pipe array (MHPA) was invented, and the experiments were carried out on the MHPA heat collector and water heater to test their thermal performance. Owing to its distinctive structure, the MHPA has good heat transfer ability, high reliability, high compressive strength and low cost. The structure and character of the novel collector with MHPA as the high-efficiency heat transfer element are as follows. First, the contact surface between the absorber and the MHPA is so large that the heat resistance is smaller than the traditional one, thus its thermal transfer capability is greatly improved. Second, the condenser section of the MHPA is connected closely to the heat exchanger with dry type. The heat pipes do not contact with water, which precludes scaling and leakage in the collector. Third, the MHPA uses low freezing points of the refrigerants, which makes the collector more suitable for extremely cold areas. Fourth, the MHPA is made of aluminum instead of copper, which could reduce the fabrication cost significantly. Fifth, the unique heat exchanger could exclude water easily

  14. First experiments for the detection of simulated mammographic lesions. Digital full field mammography with a new detector with a double plate of pure selenium; Erste Untersuchungen zur Detektion simulierter mammographischer Laesionen. Digitale Vollfeldmammographie mit einem Doppelschicht-Selen-Detektor

    Energy Technology Data Exchange (ETDEWEB)

    Schulz-Wendtland, R.; Wenkel, E.; Adamietz, B.; Lell, M.; Anders, K.; Uder, M. [Universitaetsklinikum Erlangen, Abteilung Gynaekologische Radiologie, Radiologisches Institut, Erlangen (Germany); Hermann, K.P. [Universitaetsmedizin Goettingen, Abteilung Diagnostische Radiologie, Goettingen (Germany)

    2011-02-15

    The article describes an experimental phantom study of a system for digital full field mammography with a new digital detector with a double plate of pure selenium. The experiments were carried out with the new full field digital mammography system Amulet from FujiFilm. This system has a new detector (18 x 24 cm{sup 2}) on the basis of highly purified amorphous selenium (a-Se) with a pixel size of 50 {mu}m. The x-rays are converted into electric signals in the first plate which are read into the second plate with the help of an optical switch and demonstrated in the form of an image. In this way a better pixel size/volume and signal-to-noise ratio should be achieved. The object of the investigation was the Wisconsin Mammographic Random Phantom, Model 152 A (Technical Performance Mo/Mo, 28 kV, 100 mAs). Five investigators with different experiences in mammography each received three images on a monitor with different random positions of the simulated lesions in the phantom for assessment. The detection rates were compared under the same conditions with the results of two other full field digital mammography systems. The median detection rate for all images and investigators for the new doubled plated a-Se detector with optical switch was 98.7%. For both other systems with a-Si or and a-Se detectors the detection rate was 89.8% or 97.3%, respectively. There were no significant differences in the detection rate of the simulated breast lesions for all three systems considering the interobserver and intraobserver variation. The first phantom study for the detection of simulated breast lesions with the new full field digital mammography system Amulet demonstrates equivalent results with the other systems used in the clinical routine. The trend towards superiority of the new system has to be confirmed in further clinical studies. (orig.) [German] Im Rahmen einer Phantomstudie sollte untersucht werden, ob ein neues System zur digitalen Vollfeldmammographie, das mit einem

  15. Plate removal following orthognathic surgery.

    Science.gov (United States)

    Little, Mhairi; Langford, Richard Julian; Bhanji, Adam; Farr, David

    2015-11-01

    The objectives of this study are to determine the removal rates of orthognathic plates used during orthognathic surgery at James Cook University Hospital and describe the reasons for plate removal. 202 consecutive orthognathic cases were identified between July 2004 and July 2012. Demographics and procedure details were collected for these patients. Patients from this group who returned to theatre for plate removal between July 2004 and November 2012 were identified and their notes were analysed for data including reason for plate removal, age, smoking status, sex and time to plate removal. 3.2% of plates were removed with proportionally more plates removed from the mandible than the maxilla. 10.4% of patients required removal of one or more plate. Most plates were removed within the first post-operative year. The commonest reasons for plate removal were plate exposure and infection. The plate removal rates in our study are comparable to those seen in the literature.

  16. Conflict Resolution Styles as Mediators of Female Child Sexual Abuse Experience and Heterosexual Couple Relationship Satisfaction and Stability in Adulthood.

    Science.gov (United States)

    Knapp, Ashlee E; Knapp, Darin J; Brown, Cameron C; Larson, Jeffry H

    2017-01-01

    Trauma from female incestuous child sexual abuse may result in negative psychological consequences affecting adult relationships. This study explored relational consequences of incestuous child sexual abuse, focusing on conflict resolution styles, relationship satisfaction, and relationship stability. Using the RELATionship Evaluation dataset, 457 heterosexual couples in which female partners experienced incestuous child sexual abuse were compared to a group of 1,827 couples with no sexual abuse history. Analyses tested differences in the frequencies of reported conflict resolution styles for incestuous child sexual abuse and non-incestuous child sexual abuse groups, the mediating effects of conflict resolution styles on the relationship between incestuous child sexual abuse, and self- and partner-reported relationship satisfaction and stability. Significant differences in the reports of types of conflict resolution styles were found for incestuous child sexual abuse versus non-incestuous child sexual abuse groups. Incestuous child sexual abuse and conflict resolution styles were negatively related to relationship satisfaction and stability and there was a significant indirect effect between female incestuous child sexual abuse, female volatility, and relationship instability. Clinical applications for couple relationships are discussed.

  17. Anisotropic elastic plates

    CERN Document Server

    Hwu, Chyanbin

    2010-01-01

    As structural elements, anisotropic elastic plates find wide applications in modern technology. The plates here are considered to be subjected to not only in plane load but also transverse load. In other words, both plane and plate bending problems as well as the stretching-bending coupling problems are all explained in this book. In addition to the introduction of the theory of anisotropic elasticity, several important subjects have are discussed in this book such as interfaces, cracks, holes, inclusions, contact problems, piezoelectric materials, thermoelastic problems and boundary element a

  18. Plating in Top Agar

    OpenAIRE

    sprotocols

    2014-01-01

    1. Warm plates to room temperature before use. Cold plates causes the top agar to solidify irregularly. DO not warm plates to 37° as the top agar will take forever to solidify. - Prepare top agar as the appropriate liquid medium with 0.7% agar. Keeping 100 mL bottles is convenient. For phages, use λ top agar, which is less rich and yields bigger plaques. - Melt top agar in the microwave completely. Allow the agar to boil after liquification; incompletely melted agar looks liquid, but is...

  19. Effect of Rolling Parameters on Plate Curvature during Snake Rolling

    Institute of Scientific and Technical Information of China (English)

    FU Yao; XIE Shuisheng; XIONG Baiqing; HUANG Guojie; CHENG Lei

    2012-01-01

    In order to predict the plate curvature during snake rolling,FE model was constructed based on plane strain assumption.The accuracy of the FE model was verified by the comparison between the plate curvature conducted by FE model and experiment respectively.By using FE model,the effect of offset distance,speed ratio,reduction,roll radius and initial plate thickness on the plate curvature during snake rolling was investigated.The experimental results show that,a proper offsetting distance can efficiently decrease plate curvature,however an excessive offsetting distance will increase plate curvature.A larger speed ratio,reduction will cause a large plate curvature,however a larger roll radius has effect to reduce plate curvature.Plate which undergoes a larger reduction and plate with a larger initial thickness always need a larger offset distance to keep the plate the minimum plate curvature,but for a larger roll radius a smaller offset distance is needed.

  20. 空气-水复合平板型太阳能集热器%Experiment test of hybrid air-water solar flat plate collector

    Institute of Scientific and Technical Information of China (English)

    赵东亮; 代彦军; 李勇

    2011-01-01

    This paper focuses on a new type of solar collector that has the potential for using in solar heating systems. It can use both air and water as the circulation mediums. Experiment results show that the collector efficiency is between 55%~65% when air is used as the circulation medium, while the efficiency is between 32%~34% for using water as the circulation medium, and it can meet the requirement of solar heating systems. Moreover, this collector is fairly cheap, therefore, especially suitable for the rural areas in north China.%提出了一种适用于太阳能供热采暖工程的新型太阳能空气-水复合平板集热器.该集热器可以单独使用空气、水或同时以空气和水作为集热工质.测试显示,该集热器空气循环集热效率为55%~65%,水循环集热效率为32%~34%,能够满足太阳能供热采暖工程的要求.该集热器成本不高,适用于在我国北方广大农村地区推广使用.

  1. Three-dimensional motion stability of upper thoratic anterior titanium plate fixed system: An in vitro biomechanical study%体外生物力学评价上胸椎前路钛板内固定装置的三维运动稳定性

    Institute of Scientific and Technical Information of China (English)

    罗巨利; 詹新立; 肖增明; 贺聚良; 刘会江; 赵卫东

    2011-01-01

    BACKGROUND: There are few reports about in vitro biomechanical studies of anterior cervical locking plate for upper thoracic reconstruction .OBJECTIVE: To evaluate the biomechanical characters of self-designed upper thoratic anterior titanium plate fixed system.METHODS: Intact C7-T6 specimens from 15 fresh corpses were randomly divided into three groups: group B with upper thoracic anterior titanium plate fixation (UTAPF), group C with prespred anterior cervical plate fixation (ACPF), group D with imprespred ACPF. Range of motion (ROM) was tested for the natural intact specimens. Measurement of three-dimensional stability was performed in flexion, extension and lateral bending and rotation state in groups B, C, D after fixation.RESULTS AND CONCLUSION: ROM of the natural intact specimens in the three groups had no significant difference (P > 0.05).The stability of flexion arranged as follows: B>D>C>intact specimens (A). Significant difference between B and A was found (P=0.012). The stability of extension arranged as follows: B>C>A>D, but there was no significant difference among different groups. The stability of rotation arranged B>C>A>D. Between groups no significant difference was found in the rotation condition.The order of stabilities under the lateral bending was A>B>C>D. There were significant differences between A and C as well as between A and D (P=0.005, P=0.002). The findings indicate that the upper thoracic anterior titanium plate has a better biomechanical stability than cervical plate. If cervical anterior plate was applied to upper thoratic spine, plate should be prespred according to kyphosis of the upper thoratic spine.%背景:国内外少见颈前路带锁钢板重建上胸椎的体外生物力学报道.目的:从生物力学角度评价自行研制的上胸椎前路钛板内固定装置.方法:15具成人尸体上胸椎标本分成3组,即上胸椎前路钛板内固定组(B),颈前路钛板预弯内固定组(C),颈前路

  2. Characterization of Tri-lab Tantalum Plate.

    Energy Technology Data Exchange (ETDEWEB)

    Buchheit, Thomas E.; Cerreta, Ellen K.; Deibler, Lisa Anne; Chen, Shu-Rong; Michael, Joseph R.

    2014-09-01

    This report provides a detailed characterization Tri-lab Tantalum (Ta) plate jointly purchased from HCStark Inc. by Sandia, Los Alamos and Lawrence Livermore National Laboratories. Data in this report was compiled from series of material and properties characterization experiments carried out at Sandia (SNL) and Los Alamos (LANL) Laboratories through a leveraged effort funded by the C2 campaign. Results include microstructure characterization detailing the crystallographic texture of the material and an increase in grain size near the end of the rolled plate. Mechanical properties evaluations include, compression cylinder, sub-scale tension specimen, micohardness and instrumented indentation testing. The plate was found to have vastly superior uniformity when compare with previously characterized wrought Ta material. Small but measurable variations in microstructure and properties were noted at the end, and at the top and bottom edges of the plate.

  3. Modified tubularized incised plate urethroplasty

    Directory of Open Access Journals (Sweden)

    Shivaji Mane

    2013-01-01

    Full Text Available Aim: To share our experience of doing tubularized incised plate urethroplasty with modifications. Materials and Methods: This is a single surgeon personal series from 2004 to 2009. One hundred patients of distal hypospadias were subjected for Snodgrass urethroplasty with preputioplasty. The age range was 1 to 5 year with mean age of 2.7 years. Selection criteria were good urethral plate, without chordee and torsion needing complete degloving. Main technical modification from original Snodgrass procedure was spongioplasty, preputioplasty, and dorsal slit when inability to retract prepuce during surgery. Results: Average follow-up period is 23 months. Seven (7% patients developed fistula and one patient had complete preputial dehiscence. Phimosis developed in three (3% patients and required circumcision. Dorsal slit was required in seven patients. One patient developed meatal stenosis in postoperative period. All other patients are passing single urinary stream and have cosmesis that is acceptable. Conclusions: Modified tubularized incised plate urethroplasty with preputioplasty effectively gives cosmetically normal looking penis with low complications.

  4. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... but changes the portion sizes so you are getting larger portions of non-starchy vegetables and a ...

  5. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... 4/Box) Taking the guesswork out of portion control has never been easier. It can be a ...

  6. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  7. MyPlate

    Science.gov (United States)

    ... our stage of life, situations, preferences, access to food, culture, traditions, and the personal decisions we make over time. All your food and beverage choices count. MyPlate offers ideas and ...

  8. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: September ...

  9. Designing Assemblies Of Plates

    Science.gov (United States)

    Williams, F. W.; Kennedy, D.; Butler, R.; Aston, G.; Anderson, M. S.

    1992-01-01

    VICONOPT calculates vibrations and instabilities of assemblies of prismatic plates. Designed for efficient, accurate analysis of buckling and vibration, and for optimum design of panels of composite materials. Written in FORTRAN 77.

  10. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning What Can I Eat? Making Healthy Food Choices Diabetes Superfoods Non-starchy Vegetables Grains and Starchy Vegetables ...

  11. Create Your Plate

    Medline Plus

    Full Text Available ... Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning ... serving of dairy or both as your meal plan allows. Choose healthy fats in small amounts. For ...

  12. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Diabetes Get Started Safely Get And Stay Fit Types of Activity Weight Loss Assess Your Lifestyle ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  13. Create Your Plate

    Medline Plus

    Full Text Available ... Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... been easier. It can be a challenge to manage portion control wherever you are. Now, our best- ...

  14. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  15. Create Your Plate

    Medline Plus

    Full Text Available ... Carbohydrates Carbohydrate Counting Make Your Carbs Count Glycemic ... to manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  16. Origami - Folded Plate Structures

    OpenAIRE

    Buri, Hans Ulrich

    2010-01-01

    This research investigates new methods of designing folded plate structures that can be built with cross-laminated timber panels. Folded plate structures are attractive to both architects and engineers for their structural, spatial, and plastic qualities. Thin surfaces can be stiffened by a series of folds, and thus not only cover space, but also act as load bearing elements. The variation of light and shadow along the folded faces emphasizes the plas...

  17. Fractal multifiber microchannel plates

    Science.gov (United States)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

  18. When Did Plate Tectonics Begin

    Science.gov (United States)

    Brown, M.

    2015-12-01

    Present-day plate tectonics on Earth is characterized by asymmetric (one-sided) subduction, but how do we recognize the imprint of subduction in the geologic record? How do we weigh global (commonly younger) vs local (commonly older) datasets or distinguish initiation from episodic from continuous subduction? How reliable are data gaps? Characteristics of the Paleozoic record of subduction include calc-alkaline magmatism, blueschist/UHP metamorphism and collisional orogenesis, and ophiolites as representatives of former ocean lithosphere. Are these characteristic rocks preserved in Proterozoic, Archean and Hadean crust? Does a hotter mantle, higher heat production and weaker lithosphere modify or eliminate these features? What preceded subduction and how do we recognize that regime? Are rock associations or geochemical fingerprints reliable? Does reworking and overprinting modify geochemical fingerprints? Proposals for the start of plate tectonics have been based on: persistence of isotope anomalies/fractionated chemical domains in the mantle; changes in chemistry of magmatic rocks, rates of crustal growth vs reworking, and sites of growth; the metamorphic record, particularly the first appearance of contrasting thermal gradients or eclogite (including evidence from mineral inclusions in diamonds) or UHP metamorphic rocks; stabilization of cratonic lithosphere and formation of supercratons, and the beginning of the Proterozoic supercontinent cycle; the end of the flat Earth, emergence of continents, development of significant topography, changes in the style of orogeny and the rise in atmospheric oxygen; and, the appearance of passive margins and changes in the style of sedimentation. Estimates of the timing have varied from the Hadean to Neoproterozoic. I will summarize evidence for a growing consensus that the late Mesoarchean to early Paleoproterozoic was a 700 Myr long period of transition to continuous (?) subduction and global (?) mobile-lid plate tectonics.

  19. Petrologic implications of plate tectonics.

    Science.gov (United States)

    Yoder, H S

    1971-07-30

    Petrologists can make significant contributions to the plate tectonic concept. Fixing the stability fields of the principal rock types involved will provide the limits of pressure and temperature of the various environments. Experimental determination of the partition coefficients of the trace elements will be helpful. Studies of the partial melting behavior of possible parental materials in the absence and presence of water, especially the undersaturated region, will contribute to the understanding of magma production. Experimental observations on the rheological properties of the peridotites below and just above the solidus will lead to a better evaluation of the convective mechanism. Measurement of the fundamental properties of rocks, such as the density of solids and liquids at high pressures and temperatures, would contribute to understanding the concepts of diapiric rise, magma segregation, and the low-velocity zone. Broader rock sampling of the oceanic areas of all environments will do much to define the petrologic provinces. The field petrologist specializing in the Paleozoic regions and Precambrian shields can contribute by examining those regions for old plate boundaries and devising new criteria for their recognition.

  20. Vibration and Buckling of Web Plate of the Plate Girder

    OpenAIRE

    高橋, 和雄; 呉, 明強; 中澤, 聡志; 筑紫, 宏之

    1998-01-01

    The vibration and buckling of the web of the plate girder are studied in this paper. The small deflection theory of the thin plate is used. The finite strip method is employed to solve vibration and buckling of the plate girder. Natural frequenies of buckling properties are shown for various plate girder bridges.

  1. PHILOS 接骨板治疗复杂肱骨干中上段骨折的初步报告%Fixation of complex middle-proximal humeral shaft fractures using the PHILOS plate: early experience

    Institute of Scientific and Technical Information of China (English)

    陈雁西; 梅炯; 李山珠; 王树青; 张世民; 程黎明; 王先辉; 刘新成; 俞光荣

    2008-01-01

    Objective To evaluate the clinical outcomes of the proximal humeral internal locking system (PHILOS) plate treating the complex middle-proximal humeral shaft fractures.Methods From April 2007 to January 2008,a total of 16 patients with acutely complex middle-proximal humeral shaft fractures were treated by open reduction and internal fixation using the PHILOS plate.There were 6 males and 10 females with an average age of 71.5 years (range,54-88 years),the left side was involved in 11 cases,and the right side was involved in 5 cases.According to AO/OTA classification,4 cases belonged to CI,3 to C2,and 9 to C3.The operative time,PHILOS plate insertion time and operative blood loss were recorded.Functional assessment was done using the Constant-Murley shoulder score and percentage Constant-Murley score,>80% was excellent or good,60%-80% was satisfactory,and < 60% was poor.Results The mean operative time was 115 min(range,75-160 min),PHILOS plate insertion time was 35 min(range,25-45 min),operative blood loss was 350 ml (range,150-525 ml) and hospitalization time was 18.5 d (range,17-22 d).In 14 patients,the mean follow-up time was 9.6 months (range,5-12 months).The mean fractures healing time was 12.1 weeks (range,7-16 weeks).No complications were found,such as delayed union and nonunion,displaced,avascular necrosis,cutout or backout of the screws and plates.The mean ROM of the shoulders was 150°(range,120°-170°).The Constant-Murley score of the injury side was mean 78.5 (range,62-92) at the final follow-up,which was 87.6% (range,75.6%-97.6%) of the Constant-Murley score of normal side.The clinical outcomes were excellent or good in 12 cases(85.7%),satisfactory in 2 eases.Conclusion According to our experience,the PHILOS plate design provides stable fixation with a good functional outcome for the complex middle-proximal humeral shaft fractures and eliminates most hardware problems and complications.%目的 评价肱骨近端内固定锁定系统(PHILOS)接骨

  2. Micro-buried spiral zone plate in a lithium niobate crystal

    Science.gov (United States)

    Tian, Zhen-Nan; Hua, Jian-Guan; Hao, Juan; Yu, Yan-Hao; Chen, Qi-Dai; Sun, Hong-Bo

    2017-01-01

    We present a micro-buried spiral zone plate (MBSZP) in the lithium niobate crystal fabricated with femtosecond laser direct writing technology. The microstructures of the MBSZP are buried under the surface of the crystal, which ensures the stability of the optical performance in various refractive index environments. The optical performances of imaging and focusing capabilities were demonstrated. In addition, the experiment showed good agreement with simulation results based on the optical wave propagation method. This novel optical element will have important applications in multistate information encoding, optical manipulation, quantum communication, and computation, especially in high integration, contact coupling, and variable refractive index environments.

  3. The EEE Project: Cosmic rays, multigap resistive plate chambers and high school students

    CERN Document Server

    Abbrescia, M.; Antolini, R; Avanzini, C; Baldini Ferroli, R; Bencivenni, G; Bossini, E; Bressan, E; Chiavassa, A; Cicalo, C; Cifarelli, L; Coccia, E; De Gruttula, D; De Pasquale, S; Di Giovanni, A; D'Incecco, M; Doroud, K; Dreucci, M; Fabbri, FL; Frolov, V; Garbini, M; Gemme, G; Gnesi, I; Gustavino, C; Hatzifotiadu, D; La Rocca, P; Li, S; Moro, R; Miozzi, S; Massai, M; Maggiora, A; Librizzi, F; Piragino, G; Pilo, F; Perasso, L; Paoletti, R; Righini, GC; Scapparone, E; Sartorelli, G; Romano, F; Serci, S; Selvi, M; Scribano, A; Riggi, F; Regano, A; Squarcia, S; Spandre, G; Toselli, F; Taiuti, M; Zichichi, A; Zouyevski, R; Williams, MCS; Votano, L; Siddi, E; Panareo, M

    2012-01-01

    The Gas Gain Monitoring (GGM) system of the Resistive Plate Chamber (RPC) muon detector in the Compact Muon Solenoid (CMS) experiment provides fast and accurate determination of the stability in the working point conditions due to gas mixture changes in the closed loop recirculation system. In 2011 the GGM began to operate using a feedback algorithm to control the applied voltage, in order to keep the GGM response insensitive to environmental temperature and atmospheric pressure variations. Recent results are presented on the feedback method used and on alternative algorithms.

  4. Role of locking plates in treatment of difficult ununited fractures: a clinical study

    Institute of Scientific and Technical Information of China (English)

    Ashok Kumar; Himanshu Gupta; Chandra Shekhar Yadav; Shah Alam Khan; Shishir Rastogi

    2013-01-01

    Objective:To present our experience in treatment of difficult ununited long bone fractures with locking plate.Methods:Retrospective evaluation of locking plate fixation in 10 difficult nonunions of long bone fractures was done.Fixation was done with locking plate for femoral shaft fracture (3 patients),supracondylar fracture of femur (gap nonunion),fracture of clavicle,fracture of both forearm bones (radius and ulna) fracture of ulna,fracture of shaft of humerus,fracture of tibial diaphysis and supracondylar fracture of humerus (one patient each).Five fractures had more than one previous failed internal fixation.One patient had infected nonunion which was managed by debridement with cast immobilization followed by fixation with locking plate at six weeks.Seven fractures were atrophic,two were oligotrophic,and one was hypertrophic.Fibular autograft was used in 2 cases and iliac crest cancellous bone graft used in all the patients.Results:Minimum follow-up was 6 months (range,6 months to 2.5 years).Average rime for union was 3.4 months (range 2.5 to 6 months).None of the patients had platerelated complications or postoperative wound infections.Conclusion:Along with achieving stability with locking compression plate,meticulous soft tissue dissection,acceptable reduction,good fixation technique and bone grafting can help achieve union in difficult nonunion cases.Though locking plate does not by itself ensure bony union,we have found it to be another useful addition to our armamentarium for treating difficult fracture nonunions.

  5. Interplay between theory and experiment for fission-fragment angular distributions from nuclei near the limits of stability

    Science.gov (United States)

    Freifelder, R.; Prakash, M.; Alexander, John M.

    1986-02-01

    We examine the application of transition-state theory for fission-fragment angular distributions to composite nuclei near the limits of stability. The possible roles of saddle-point and scission-point configurations are explored. For many heavy-ion reactions that involve large angular momenta, the observed anisotropies are between the predictions of the saddle-point and scisson-point models. Empirical correlations are shown between the effective moments of inertia and the spin and {Z 2}/{A} of the compound nucleus. These correlations provide evidence for a class of transition-state nuclei intermediate between saddle- and scission-point configurations. An important indication of these patterns is that the speed of collective deformation toward fission may well be slow enough to allow for statistical equilibrium in the tilting mode even for configurations well beyond the saddle point.

  6. The impact of heating the breakdown bubble on the global mode of a swirling jet: Experiments and linear stability analysis

    CERN Document Server

    Rukes, Lothar; Paschereit, Oliver; Oberleithner, Kilian

    2016-01-01

    This study investigates the dynamics of non-isothermal swirling jets undergoing vortex breakdown, with an emphasis on helical coherent structures. It is proposed that the dominant helical coherent structure can be suppressed by heating the recirculation bubble. This proposition is assessed with Stereo Particle Image Velocimetry (PIV) measurements of the breakdown region of isothermal and heated swirling jets. The coherent kinetic energy of the dominant helical structure was derived from PIV snapshots via Proper Orthogonal Decomposition. For one set of experimental parameters, mild heating is found to increase the energy content of the dominant helical mode. Strong heating leads to a reduction by 30\\% of the coherent structures energy. For a second set of experimental parameters, no alteration of the dominant coherent structure is detectable. Local linear stability analysis of the time-averaged velocity fields shows that the key difference between the two configurations is the density ratio at the respective w...

  7. Development of a stabilized low temperature infrared absorption cell for use in low temperature and collisional cooling experiments.

    Science.gov (United States)

    Valentin, A; Henry, A; Claveau, C; Camy-Peyret, C; Hurtmans, D; Mantz, A W

    2004-12-01

    We have constructed a stabilized low temperature infrared absorption cell cooled by an open cycle refrigerator, which can run with liquid nitrogen from 250 to 80K or with liquid helium from 80K to a few kelvin. Several CO infrared spectra were recorded at low temperature using a tunable diode laser spectrometer. These spectra were analyzed taking into account the detailed effects of collisions on the line profile when the pressure increases. We also recorded spectra at very low pressure to accurately model the diode laser emission. Spectra of the R(2) line in the fundamental band of 13CO cooled by collisions with helium buffer gas at 10.5K and at pressures near 1 Torr have been recorded. The He-pressure broadening parameter (gamma(0) = 0.3 cm(-1) atm(-1)) has been derived from the simultaneous analysis of four spectra at different pressures.

  8. Cross-contextual stability of bullying victimization: a person-oriented analysis of cyber and traditional bullying experiences among adolescents.

    Science.gov (United States)

    Erentaitė, Rasa; Bergman, Lars R; Zukauskienė, Rita

    2012-04-01

    Using a person-oriented approach the study examined whether bullying victimization at school continued into cyberspace victimization in a large sample of high school students in Lithuania (N = 1667, 58% girls), age 15-19 (M = 17.29, SD = 0.95). Three forms of traditional bullying (verbal, physical and relational) and seven forms of cyberbullying victimization through cell phones and computers were included in the analysis. The findings revealed that 35% of traditional bullying victims were also bullied in cyberspace. In particular, adolescents who experienced predominantly verbal and relational bullying at school, showed a higher risk of victimization in cyberspace a year later, while this was not observed for predominantly physical forms of traditional bullying. The findings point to the importance of a cross-contextual perspective in studies on stability of bullying victimization. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

  9. Experiment of sucking precision of sucking plate with group holes on rice pneumatic metering device%水稻气力式排种器群布吸孔吸种盘吸种精度试验

    Institute of Scientific and Technical Information of China (English)

    张国忠; 罗锡文; 臧英; 王在满; 曾山; 周志艳

    2013-01-01

    Rice is the most important grain crop in China with a growing plant area year after year in recent decades. Direct seeding and transplant are the two main plant modes. Direct seeding by planter is getting popular in China, India, and other countries, with high efficacy and economy, as well as easy operation. Due to high capacity of tilling, generally three to four seeds are required for each hole in order to avoid a planter-like high empty hole rate. Meanwhile, the different variety and irregular shape of the seeds results in either excessive seeds in each hole, or empty holes when planters plant hybrid rice seeds that makes it quite difficult to meet requirements for current needs in the field. In order to realize precise farming, a unique precise pneumatic metering device was designed with a group sucking plate in seed metering device, by which three to four seeds can be sucked and dropped at the same time. The plate was divided into five parts, a seed sucking place, seed clearing place, seed carrying place, seed dropping place, and a blank place. The seeds were sucked by the vacuum and rotated to the dropping place by the plate. Different influences from the diameter of the hole, vacuum degree, and clear-up equipment on precision of metering devices have been discussed. In the experiment, the sucking plate rotating speed was 8 rpm and its diameter was 165mm. Rice varieties were Indic hybrid Peizataifeng whose moisture content (wet basis) was 11.6%~11.9%, and its 1000-grain was 22 g. Its overall dimension (length×width×thickness) was 8.94mm×2.30mm×1.94mm,and the 4×24 orthogonal experiments were conducted to investigate the suck characteristic of the group holes on the sucking plate under vacuum, diameter of the holes, and the seed-clearing device. The experimental equipment consisted of a pneumatic metering device with group holes, a U-shaped manometer, a positive and negative pressure air pipeline, a cut-off valve, and a vortex pump. The sucking probability

  10. Plates of the dinosaur stegosaurus: forced convection heat loss fins?

    Science.gov (United States)

    Farlow, J O; Thompson, C V; Rosner, D E

    1976-06-11

    It is suggested that the plates along the arched back and tail of Stegosaurus served an important thermoregulatory function as forced convection "fins." Wind tunnel experiments on finned models, internal heat conduction calculations, and direct observations of the morphology and internal structure of stegosaur plates support this hypothesis, demonstrating the comparative effectiveness of the plates as heat dissipaters, controllable through input blood flow rate, temperature, and body orientation (with respect to wind).

  11. Oblique Impact of Projectile on Thin Aluminium Plates

    Directory of Open Access Journals (Sweden)

    W.U. Khan

    2003-04-01

    Full Text Available Experiments were performed, wherein cylindrical projectiles made of hardened steel were impacted on commercially available aluminium plates at different angles. Projectiles were of 12.8 mm diameter and plates were of 0.81 mm, 1.52mm and 1.91mm thicknesses. Based on the experimental results, an analytical model has been developed to predict the residual velocity of the projectile and the ballistic limit of the plate.

  12. Bending and stretching of plates

    CERN Document Server

    Mansfield, E H; Hemp, W S

    1964-01-01

    The Bending and Stretching of Plates deals with elastic plate theory, particularly on small- and large-deflexion theory. Small-deflexion theory concerns derivation of basic equations, rectangular plates, plates of various shapes, plates whose boundaries are amenable to conformal transformation, plates with variable rigidity, and approximate methods. Large-deflexion theory includes general equations and some exact solutions, approximate methods in large-deflexion theory, asymptotic large-deflexion theories for very thin plates. Asymptotic theories covers membrane theory, tension field theory, a

  13. Optimizing Casimir torque between corrugated metallic plates

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Robson B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil); Maia Neto, Paulo A. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-07-01

    Full text: The Casimir effect plays a major role in micro- and nano-electromechanical systems (MEMS and NEMS). Besides the normal Casimir force between metallic or dielectric plates, the observation of the lateral Casimir force between corrugated plates opens novel possibilities of micro-mechanical control. The lateral force results from breaking the translational symmetry along directions parallel to the plates by imprinting periodic corrugations on both metallic plates. As the rotational symmetry is broken by this geometry, a Casimir torque arises when the corrugations are not aligned. We calculate the Casimir torque between two parallel metallic plates with surface profiles in the form of 'fans' with arbitrary relative spatial orientation. As compared to the case of anisotropic dielectric plates, the torque per unit area is increased by up to three orders of magnitude for a given separation distance. The experiment proposed here can be performed with torsion pendulum techniques for separation distances as large as 1 μm. From the point of view of fundamental physics, this torque makes possible a precise experimental investigation of the non-trivial geometry dependence of the Casimir effect. We follow the scattering approach and calculate the Casimir energy up to second order in the corrugation amplitudes, taking into account nonspecular reflections, polarization mixing and the finite conductivity of the metals. We investigate the experimental conditions that optimize the effect. (author)

  14. Resistive Plate Chambers commissioning and performance results for 2015

    CERN Document Server

    CMS Collaboration

    2016-01-01

    The Resistive Plate Chamber (RPC) detector system at the Compact Muon Solenoid experiment at the LHC confers robustness and redundancy to the muon trigger. During the first long shutdown of the LHC (2013-2014) the CMS muon RPC system has been upgraded with 144 double-gap chambers on the forth forward stations. A total of 1056 double-gap chambers cover the pseudo-rapidity region up to 1.6. The main detector parameters are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC (13 TeV and 25 ns bunch spacing). Resistive Plate Chambers (RPC) performance results for 2015 with pp collisions at 13 TeV are presented. These results include the occupancy, efficiency of newly installed detectors after applying new working point, history plots for the RPC relevant variables such as: Cluster Size, Efficiency, percentage of inactive detector during operation and Rates and overall system noise. RPC variables are studied as funct...

  15. SU-E-T-448: On the Perturbation Factor P-cav of the Markus Parallel Plate Ion Chambers in Clinical Electron Beams, Monte Carlo Based Reintegration of An Historical Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Voigts-Rhetz, P von; Zink, K [Technische Hochschule Mittelhessen - University of Applied Sciences, Giessen, Hessen (Germany)

    2014-06-01

    Purpose: All present dosimetry protocols recommend well-guarded parallel-plate ion chambers for electron dosimetry. For the guard-less Markus chamber an energy dependent fluence perturbation correction pcav is given. This perturbation correction was experimentally determined by van der Plaetsen by comparison of the read-out of a Markus and a NACP chamber, which was assumed to be “perturbation-free”. Aim of the present study is a Monte Carlo based reiteration of this experiment. Methods: Detailed models of four parallel-plate chambers (Roos, Markus, NACP and Advanced Markus) were designed using the Monte Carlo code EGSnrc and placed in a water phantom. For all chambers the dose to the active volume filled with low density water was calculated for 13 clinical electron spectra (E{sub 0}=6-21 MeV) at the depth of maximum and at the reference depth under reference conditions. In all cases the chamber's reference point was positioned at the depth of measurement. Moreover, the dose to water DW was calculated in a small water voxel positioned at the same depth. Results: The calculated dose ratio D{sub NACP}/D{sub Markus}, which according to van der Plaetsen reflects the fluence perturbation correction of the Markus chamber, deviates less from unity than the values given by van der Plaetsen's but exhibits a similar energy dependence. The same holds for the dose ratios of the other well guarded chambers. But, in comparison to water, the Markus chamber reveals the smallest overall perturbation correction which is nearly energy independent at both investigated depths. Conclusion: The simulations principally confirm the energy dependence of the dose ratio D{sub NACP}/D{sub Markus} as published by van der Plaetsen. But, as shown by our simulations of the ratio D{sub W}/D{sub Markus}, the conclusion drawn in all dosimetry protocols is questionable: in contrast to all well-guarded chambers the guard-less Markus chamber reveals the smallest overall perturbation

  16. On the Bending, Vibration and Stability of Laminated Rectangular Plates With Transversely Isotropic Layers%横观各向同性层合矩形板弯曲、振动 和稳定的三维精确分析

    Institute of Scientific and Technical Information of China (English)

    丁皓江; 陈伟球; 徐荣桥

    2001-01-01

    针对四边简支的横观各向同性矩形板的弯曲 、 振动和稳定给出了新的状态空间分析方法从横观各向同性弹性力学的三维基本方程出发, 通过引入位移函数和应力函数, 构造了两类相互独立的状态空间方程, 不仅使原方程得到解耦而且降低了阶数,十分有利于具体问题的求解对于四边简支的矩形板, 建立了层合板上下表面状态变量间的关系式特别针 对矩形板的自由振动(稳定)问题, 发现存在两类彼此无关的形式, 一类对应板的纯面内振动(稳定), 而另一类则是一般意义上的板的弯曲振动(稳定)给出了数值结果, 并考察了相关参数的影响%A method based on newly presented state space formulations is developed for analyzing the bending, vibratio n and stability of laminated transversely isotropicrectangular plates with simp ly supported edges. By introducing two displacement functions and two stress fun ctions, two independent state equations were constructed based on the three-dime n sional elasticity equations for transverse isotropy. The original differential e quations are thus decoupled with the order reduced that will facilitate obtainin g solutions of various problems. For the simply supported rectangular plate, two relations between the state variables at the top and bottom surfaces were estab l ished. In particular, for the free vibration (stability) problem, it is found th at there exist two independent classes: One corresponds to the pure in-plane vib ration (stability) and the other to the general bending vibration (stability). N umerical examples are finally presented and the effects of some parameters are discussed.

  17. Wavelength-tunable multicolored femtosecond laser pulse generation in a fused silica glass plate

    Science.gov (United States)

    Kobayashi, Takayoshi; Liu, Jun

    2010-05-01

    We obtained an array of multicolored femtosecond laser pulses with as many as 17 different colors that are spatially isolated. The mechanism of generation was proved to be cascaded four-wave mixing and with the following procedure. The output beam from a femtosecond laser was split into two. One of the two beams was pulse-compressed with a hollow core fiber and the intensity of the other was reduced. The two beams were synchronized and combined with a small crossing angle in a plate of fused silica glass plate. The wavelengths of the sidebands are continuously tunable from near-ultraviolet to near-infrared. The pulse duration, spatial mode, spectrum, and energy stability of the sidebands were studied. As many as fifteen spectral up-shifted pulses and two spectral downshifted pulses were obtained with spectral bandwidths broader than 1.8 octaves. Properties such as pulse energy as high as 1 μmJ, 45 fs pulse duration, smaller than 1.1 times of the diffraction limit Gaussian spatial profile, and better than 2% RMS power stability of the generated sidebands make it can be used in various experiments. The characterization showed that the sidebands have sufficiently good qualities to enable application to for various multicolor femtosecond laser experiments, for example, a multicolor pump-probe experiment.

  18. Anterior cervical plating

    Directory of Open Access Journals (Sweden)

    Gonugunta V

    2005-01-01

    Full Text Available Although anterior cervical instrumentation was initially used in cervical trauma, because of obvious benefits, indications for its use have been expanded over time to degenerative cases as well as tumor and infection of the cervical spine. Along with a threefold increase in incidence of cervical fusion surgery, implant designs have evolved over the last three decades. Observation of graft subsidence and phenomenon of stress shielding led to the development of the new generation dynamic anterior cervical plating systems. Anterior cervical plating does not conclusively improve clinical outcome of the patients, but certainly enhances the efficacy of autograft and allograft fusion and lessens the rate of pseudoarthrosis and kyphosis after multilevel discectomy and fusions. A review of biomechanics, surgical technique, indications, complications and results of various anterior cervical plating systems is presented here to enable clinicians to select the appropriate construct design.

  19. Computational investigations of mechanical failures of internal plate fixation.

    Science.gov (United States)

    Chen, G; Schmutz, B; Wullschleger, M; Pearcy, M J; Schuetz, M A

    2010-01-01

    This paper investigated the biomechanics of two clinical cases of bone fracture treatments. Both fractures were treated with the same locking compression plate but with different numbers of screws as well as different plate materials. The fracture treated with 12 screws (rigid fixation) failed at 7 weeks with the plate breaking; the fracture with six screws (flexible fixation) endured the entire healing process. It was hypothesized that the plate failure in the unsuccessful case was due to the material fatigue induced by stress concentration in the plate. As the two clinical cases had different fracture locations and different plate materials, finite element simulations were undertaken for each fractured bone fixed by both a rigid and a flexible method. This enabled comparisons to be made between the rigid and flexible fixation methods. The fatigue life was assessed for each fixation method. The results showed that the stress in the rigid fixation methods could be significantly higher than that in flexible fixation methods. The fatigue analyses showed that, with the stress level in flexible fixation (i.e. with fewer screws), the plate was able to endure 2000 days, and that the plate in rigid fixation could fail by fatigue fracture in 20 days. The paper concludes that the rigid fixation method resulted in serious stress concentrations in the plate, which induced fatigue failure. The flexible fixation gave sufficient stability and was better for fracture healing.

  20. Experiment study on fatigue behavior of composite girders with steel plate-concrete composite bridge decks%带钢板-混凝土组合桥面板的组合梁疲劳性能试验研究

    Institute of Scientific and Technical Information of China (English)

    杨勇; 周现伟; 薛建阳; 霍旭东

    2012-01-01

    In order to study the fatigue behaviour of the steel plate-concrete composite-deck composite girders under the fatigue load, constant-amplitude fatigue tests of six specimens of the steel plate-concrete composite-deck composite beam were carried out and static loading experiments of two specimens were conducted. The influence of the main factors including the upper and lower limits of fatigue load and the stress amplitude on the failure modes and the fatigue damage extent of composite girders under fatigue load were focused on. The dynamic deflection, strains of concrete and steel plates, strains of steel beam, residual deflection and residual bearing capacity were measured and analyzed. From the tests results, the fatigue life-spans of the composite girders specimens were directly related with their stress amplitudes, but the upper and lower limits of fatigue load had little effect. With regard to the fatigue failure modes of the composite girders specimens, positive moment composite girders were all failed due to collapse of the steel beam and crush of concrete of compressive zone, but not to the negative moment of composite girders, as a result of steel-beam buckling under static tests after fatigue tests. This paper were very helpful for this type of compsite girders design.%为研究带钢板-混凝土组合桥面板的组合梁在疲劳荷载下的受力性能,对2个试件进行静力试验研究,并对6个试件进行等幅疲劳试验研究。疲劳试验试件按承受正弯矩和承受负弯矩两组类型试件分别考虑,在各组试件中均主要考察疲劳荷载上、下限值及疲劳荷载幅值等因素对带钢板-混凝土组合桥面板组合梁的疲劳破坏模式及疲劳累积损伤的影响。疲劳试验过程中对组合梁试件在各主要循环加载次数下的动挠度、残余挠度、混凝土应变、底部钢板应变、试件钢梁应变及试件受弯刚度进行试验测量和分析。疲劳试验结果表明:正

  1. [Study of the effect of light source stability on the signal to noise ratio in degenerate four wave mixing experiment].

    Science.gov (United States)

    Wang, Wei-Bo; Chen, De-Ying; Fan, Rong-Wei; Xia, Yuan-Qin

    2010-02-01

    The effects of the stability of dye laser on the signal to noise ratio in degenerate four-wave mixing (DFWM) were first investigated in iodine vapor using forward geometries. Frequency-doubled outputs from a multi-mode Nd : YAG laser pumped dye laser with laser dye PM580 dissolved in ethanol was used. With the help of forward compensated beam-split technique and imaging detecting system, the saturation intensity of DFWM spectrum in the iodine vapor at 5 554.013 nm was first measured to be 290 microJ under the condition of atmospheric pressure and room temperature. The features of the dye laser such as wavelength ranges, beam quality and energy conversion efficiency decreased gradually with increasing pumping service use, pulse number and intensity. Additionally, with the comparison of the stable and unstable dye laser output, it was found that the instability of dye laser output had greatly influenced the DFWM signal and decreased the signal to background noise ratio. Shot to shot jitter and the broadening in the output frequency leads to an effective broadening of the recorded spectrum and loss of the DFWM signal to noise ratio under the same pumping intensity at different time. The study is of importance to the detection of trace atom, molecule and radical in combustion diagnosis.

  2. Banking Models Under the Impact of the Post-Crisis Organizational Changes Apt to Confer Sustainable Financial Stability - Romanian Experience

    Directory of Open Access Journals (Sweden)

    Claudia Gabriela Baicu

    2012-06-01

    Full Text Available The global financial crisis led to substantial changes in the operating environment of banks. Reforming the regulatory framework of financial and banking activity and the increase role of state in banking systems in many countries are important factors that involve major changes in the organizing of banking activity, the strategies adopted, the business models practiced, etc. Based on these considerations, the paper examines trends in banking models after the 2007 crisis. The analysis of the banking models is performed from the perspective of the deep organizational changes that affected the banking environment and sustainable financial stability. The study focuses on the analysis of the banking sustenability and the business model in the Romanian banking system, in the context of the post-crisis organizational changes. The profound interdependence of the Romanian banking system with the banking systems of the European countries and the international tendencies in financial regulation are important factors that influence the business models of the Romanian banks. The banking model practiced in Romania continues to be the traditional one. Currently, the most important challenges of the Romanian banking system are the growth of the non-performing loans, the loans in foreign currency to unhedged borrowers, the pressure to meet the Basel III requirements, as well as the possibility that the exposure of foreign banks towards Romania to decrease.

  3. License plate detection algorithm

    Science.gov (United States)

    Broitman, Michael; Klopovsky, Yuri; Silinskis, Normunds

    2013-12-01

    A novel algorithm for vehicle license plates localization is proposed. The algorithm is based on pixel intensity transition gradient analysis. Near to 2500 natural-scene gray-level vehicle images of different backgrounds and ambient illumination was tested. The best set of algorithm's parameters produces detection rate up to 0.94. Taking into account abnormal camera location during our tests and therefore geometrical distortion and troubles from trees this result could be considered as passable. Correlation between source data, such as license Plate dimensions and texture, cameras location and others, and parameters of algorithm were also defined.

  4. Nonlinear morphoelastic plates II: Exodus to buckled states

    KAUST Repository

    McMahon, J.

    2011-05-11

    Morphoelasticity is the theory of growing elastic materials. The theory is based on the multiplicative decomposition of the deformation gradient and provides a formulation of the deformation and stresses induced by growth. Following a companion paper, a general theory of growing non-linear elastic Kirchhoff plate is described. First, a complete geometric description of incompatibility with simple examples is given. Second, the stability of growing Kirchhoff plates is analyzed. © SAGE Publications 2011.

  5. PHILOS humerus plate for a distal tibial fracture.

    Science.gov (United States)

    Twaij, Haider; Damany, Dev

    2013-01-04

    This report discusses the use of an alternative implant in the emergency fixation of a distal tibial fracture. We planned to fix the shear-type medial malleolar fracture in a closed, tri-malleolar fracture with a locking distal tibial plate. Intra-operatively, it was noted that the required plate was unavailable. A PHILOS humeral plate seemed to fit the contours of the distal tibia. The broad end of the PHILOS, when placed distally, gave options to place locking screws in the medial malleolar fragment. The fracture was stable after fixation. The patient made a full post-operative recovery and follow-up at 4 months was satisfactory. Despite adequate planning, there will be instances where one has to improvise. An understanding of the principles of fracture management can aid in finding solutions. PHILOS humeral plate may be used to stabilize a distal tibial fracture if an appropriate distal tibial locking plate is not available.

  6. Complicações determinadas por placas de cloreto de polivinila (PVC na estabilização da porção cervical caudal da coluna vertebral de cães Complications determined by polyvinylchloride (PVC plates in the stabilization of caudal cervical vertebral column of dogs

    Directory of Open Access Journals (Sweden)

    Mônica Vicky Bahr Arias

    2003-12-01

    Full Text Available Em 10 cães com peso médio de 14,6kg, as vértebras cervicais 5 e 6 foram cirurgicamente desestabilizadas através da secção do disco intervertebral e, em seguida, estabilizadas com placas ortopédicas confeccionadas com PVC de 2mm de espessura, para após 180 dias, proceder-se ao estudo histológico do tecido ósseo e conjuntivo circunvizinho. Constatou-se que o PVC causou alterações ósseas que podem ter favorecido o afrouxamento dos parafusos e a falha do implante. O material induziu ainda à formação de granuloma de corpo estranho e a reações inflamatórias locais que podem ter causado degradação do material implantado. Assim, placas de PVC, apesar de proporcionarem estabilidade e alinhamento da coluna vertebral, não satisfazem a maioria das propriedades necessárias a um biomaterial, não sendo recomendadaa a sua utilização em ortopedia veterinária.In ten dogs with an average mean weight of 14,6 kg, the cervical vertebra 5 and 6 were destabilized and fixed with plates of 2mm of thickness. The purpose of this work was to verify the effect of orthopedic PVC plates on the internal stabilization of the caudal cervical spine of dogs by studying the occurrence of alterations in the bone tissue and fibrous tissue adjacent to the plate after 180 days of permanence of the material in the dogs' organism. PVC causes progressive bone alterations, which, in the long term, could promote the loosening of the screws and failure of the implant. It also induces the formation of foreign body granuloma and inflammatory reactions which could cause degradation of the implant. Thus, PVC plates do not satisfy the majority of properties required of a biomaterial, its use not being recommended in veterinary orthopedics.

  7. STABILITY OF EXTRATERRESTRIAL GLYCINE UNDER ENERGETIC PARTICLE RADIATION ESTIMATED FROM 2 keV ELECTRON BOMBARDMENT EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Maté, B.; Tanarro, I.; Escribano, R.; Moreno, M. A.; Herrero, V. J. [Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, E-28006 Madrid (Spain)

    2015-06-20

    The destruction of solid glycine under irradiation with 2 keV electrons has been investigated by means of IR spectroscopy. Destruction cross sections, radiolysis yields, and half-life doses were determined for samples at 20, 40, 90, and 300 K. The thickness of the irradiated samples was kept below the estimated penetration depth of the electrons. No significant differences were obtained in the experiments below 90 K, but the destruction cross section at 300 K was larger by a factor of 2. The radiolysis yields and half-life doses are in good accordance with recent MeV proton experiments, which confirms that electrons in the keV range can be used to simulate the effects of cosmic rays if the whole sample is effectively irradiated. In the low temperature experiments, electron irradiation leads to the formation of residues. IR absorptions of these residues are assigned to the presence CO{sub 2}, CO, OCN{sup −}, and CN{sup −} and possibly to amide bands I to III. The protection of glycine by water ice is also studied. A water ice film of ∼150 nm is found to provide efficient shielding against the bombardment of 2 keV electrons. The results of this study show also that current Monte Carlo predictions provide a good global description of electron penetration depths. The lifetimes estimated in this work for various environments ranging from the diffuse interstellar medium to the inner solar system, show that the survival of hypothetical primeval glycine from the solar nebula in present solar system bodies is not very likely.

  8. Phase Stability for the Pd-Si System: First-Principles, Experiments, and Solution-Based Modeling

    Science.gov (United States)

    Zhou, S. H.; Huo, Y.; Napolitano, Ralph E.

    2016-01-01

    The relative stabilities of the compounds in the binary Pd-Si system were assessed using first-principles calculations and experimental methods. Calculations of lattice parameters and enthalpy of formation indicate that Pd5Si-{μ }, Pd9Si_2-{α }, Pd_3Si-{β }, Pd_2Si-{γ }, and PdSi-{δ } are the stable phases at 0 K (-273 °C). X-ray diffraction analyses (XRD) and electron probe microanalysis (EPMA) of the as-solidified and heat-treated samples support the computational findings, except that the PdSi-{δ } phase was not observed at low temperature. Considering both experimental data and first-principles results, the compounds Pd5Si-{μ }, Pd9Si2-{α }, Pd3Si-{β }, and Pd_2Si-{γ } are treated as stable phases down to 0 K (-273 °C), while the PdSi-{δ } is treated as being stable over a limited range, exhibiting a lower bound. Using these findings, a comprehensive solution-based thermodynamic model is formulated for the Pd-Si system, permitting phase diagram calculation. The liquid phase is described using a three-species association model and other phases are treated as solid solutions, where a random substitutional model is adopted for Pd-fcc and Si-dia, and a two-sublattice model is employed for Pd5Si-{μ }, Pd9Si_2-{α }, Pd_3Si-{β }, Pd_2Si-{γ }, and PdSi-{δ }. Model parameters are fitted using available experimental data and first-principles data, and the resulting phase diagram is reported over the full range of compositions.

  9. Nuclear reactor alignment plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  10. The Clavicular Hook Plate: Consequences in Three Cases.

    Science.gov (United States)

    Chandrasenan, Jeevan; Badhe, Sachin; Cresswell, Timothy; De Beer, Joe

    2007-10-01

    The small fragment AO clavicular hook plate is indicated for certain fractures of the lateral end of clavicle and for symptomatic acromio-clavicular joint dislocations where there is rupture of the stabilizing ligaments. The complex anatomy and biomechanics of the acromio-clavicular joint can lead to complications that result in damage to the joint itself or acromial erosion. In addition, the rotator cuff complex is at risk of injury when inserting the plate. We report three cases where patients who underwent hook plate fixation subsequently required removal of the implant due to complications previously unreported in current literature.

  11. A failure study of a locking compression plate implant

    Directory of Open Access Journals (Sweden)

    Nirajan Thapa

    2015-04-01

    Full Text Available In this case study a failed locking compression plate was investigated. Such plating systems are used to provide the stability to fractured bone and fixation. The locking compression plate had been separated in two pieces. One of the fracture surfaces from the failed component was investigated for surface topographical features. The visual, optical and scanning electron microscopy results indicated the presence of beach marks, intermetallic inclusions, corrosion pits and striations indicating fatigue crack propagation and overload failure. Some corrosion damage also was documented on the fractography. This case study shows that corrosion may have initiated fatigue crack which grew by the activities of daily living causing the failure.

  12. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are ... Fitness Home Food MyFoodAdvisor Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten ...

  13. Create Your Plate

    Medline Plus

    Full Text Available ... Create Your Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... year of delicious meals to help prevent and manage diabetes. Healthy Recipes: ... to your day with this guide. Ways to Give: Wear Your Cause on Your Sleeve - ...

  14. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  15. Create Your Plate

    Medline Plus

    Full Text Available ... tax-deductible gift today can fund critical diabetes research and support vital diabetes education services that improve the ... way to manage your blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ...

  16. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are ... Fitness Home Food MyFoodAdvisor Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten ...

  17. Create Your Plate

    Medline Plus

    Full Text Available ... tax-deductible gift today can fund critical diabetes research and support vital diabetes education services that improve the ... way to manage your blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ...

  18. Create Your Plate

    Medline Plus

    Full Text Available ... unsweetened tea or coffee. Featured Product Precise Portions® Go Healthy Travel Pack (4/Box) Taking the guesswork ... you are. Now, our best-selling, sectioned to-go plate with easy-sealing lid is offered in ...

  19. Create Your Plate

    Medline Plus

    Full Text Available ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing lid is offered in a 4-pack. Whether ... Research & Practice We Are Research Leaders We Support Your Doctor ...

  20. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  1. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals > Create Your Plate Share: Print Page Text Size: A A A Listen En Español Create ... somewhere in between, you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: ... Cost of Diabetes Advocate Toolkit Call to Congress Research & ...

  2. Technique for Assessing the Stability and Controllability Characteristics of Naval Aircraft Systems Based on the Rational Combination of Modeling, Identification and Flight Experiments

    Directory of Open Access Journals (Sweden)

    S. V. Nikolaev

    2015-01-01

    Full Text Available The aim of this work is to improve test quality and reliability of modern naval aircraft for assessment of stability and controllability characteristics and test shortening. To achieve this goal it is necessary to develop an algorithmic, mathematical and methodological support of the flight trials and the mathematical modeling of controlled flight modes to determine the stability and controllability characteristics of the naval aircraft.The article analyses the problems related to determining the stability and controllability characteristics under flight tests, describes the technique to correct a mathematical model of aerodynamic characteristics and engine thrust forces of modern naval aircraft. It shows the importance of using algorithm to control the correctness of onboard measurements of flight parameters. The article presents new results of identification of the aircraft aerodynamic coefficients and proves that in identifying characteristics of the longitudinal control channel it is necessary to take into account the engine thrust forces. In the article the aerodynamic coefficients, obtained by identification methods, are compared with those in the original aerodynamic data Bank.An important and new component of the work described in the fourth part of the article, is a set of computer programmes, integrated into a common interface. The development of this software has greatly improved a processing technology of the flight experiment materials and identification of the aerodynamic characteristics of the aircraft.When applying the work results in the testing phase, the required characteristics of stability and controllability are determined by simulation, and identification provides the model refinement according to the flight data.The created technology of practical identification is used to verify and refine the mathematical models according to the flight experiment data. Thus, the result is a proven and refined model of the aircraft

  3. Energy of plate tectonics calculation and projection

    Directory of Open Access Journals (Sweden)

    N. H. Swedan

    2013-02-01

    Full Text Available Mathematics and observations suggest that the energy of the geological activities resulting from plate tectonics is equal to the latent heat of melting, calculated at mantle's pressure, of the new ocean crust created at midocean ridges following sea floor spreading. This energy varies with the temperature of ocean floor, which is correlated with surface temperature. The objective of this manuscript is to calculate the force that drives plate tectonics, estimate the energy released, verify the calculations based on experiments and observations, and project the increase of geological activities with surface temperature rise caused by climate change.

  4. Evaluation of the Earth Radiation Budget Experiment (ERBE) shortwave channel's stability using in-flight calibration sources

    Science.gov (United States)

    Gibson, Michael A.; Lee, Robert B., III; Thomas, Susan

    1992-01-01

    The Earth Radiation Budget Experiment (ERBE) radiometers were designed to make absolute measurements of the incoming solar, earth-reflected solar, and earth-emitted fluxes for investigations of the earth's climate system. Thermistor bolometers were the sensors used for the ERBE scanning radiometric package. Each thermistor bolometer package consisted of three narrow field of view broadband radiometric channels measuring shortwave, longwave, and total (0.2 micron to 50 microns) radiation. The in-flight calibration facilities include Mirror Attenuator Mosaics, shortwave internal calibration source, and internal blackbody sources to monitor the long-term responsivity of the radiometers. This paper describes the in-flight calibration facilities, the calibration data reduction techniques, and the results from the in-flight shortwave channel calibrations. The results indicate that the ERBE shortwave detectors were stable to within +/- 1 percent for up to five years of flight operation.

  5. Investigation of Valve Plate in Water Hydraulic Axial Piston Motor

    Institute of Scientific and Technical Information of China (English)

    聂松林; 李壮云; 等

    2002-01-01

    This paper has introduced the developments of water hydraulic axial piston equipments.According to the effects of physicochemical properties of water on water hydraulic components,a novel valve plate for water hydraulic axial motor has been put forward,whose moment exerted by the fluid field between valve plate and bearing plate is balanced entirely.The material screening experiment of valve plate is done on the test rig.Through numerical simulation the effects of some geometry parameters on the performance of water hydraulic motor have been studied.The silencing grooves on the valve plate in water hydraulic motor can reduce the pressure shock and the occurrence of cavitation effectively.It is evident that the appropriate structure should change the wear status between matching paris and reduces the wear and specific pressure of the matching pairs.The specimen with the new type valve plate is used in a tool system.

  6. Experimental Vibration Study on the Healthy and Delaminated Composite Plates

    Energy Technology Data Exchange (ETDEWEB)

    Ullah, Israr; Sinha, Jyoti K, E-mail: Jyoti.Sinha@manchester.ac.uk [School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester M13 9PL (United Kingdom)

    2011-07-19

    Vibration based damage, in particular delamination detection, in the composite structures is an active research area. The present study is also on the dynamics of the composite plates with and without delamination based on the experimental study. The test plate made of E-glass fibre and epoxy resins has been used here. A piezo-electric shaker has been used to excite the composite plate and the acceleration responses were measured using the number of accelerometers. The dynamics of the delaminated composite plates were then compared with a healthy composite plate when the vibration experiments have been conducted at the lower modes. The paper will discuss the observations made on the measured vibration responses from both the healthy and the delaminated plates and the possibility of the delamination detection from the experimental vibration data.

  7. 基于电磁声发射的金属板裂纹检测实验研究%Experiment of crack detection of metal plate based on electromagnetically induced acoustic emission

    Institute of Scientific and Technical Information of China (English)

    张闯; 刘素贞; 杨庆新; 金亮; 李娜

    2011-01-01

    通过对金属部件进行电磁加载会在金属裂纹处激发出声发射信号,利用这一现象可以实现对金属结构件的无损检测.本文对电磁声发射技术的原理与实现进行了深入分析,设计了相应的电磁加载实验装置,并针对铝质薄板试件进行了电磁声发射试验,通过对实验采集信号进行时频分析,研究了电磁声发射信号随加载条件和试件类型的变化规律,验证了带裂纹金属上能够产生电磁声发射现象,为该技术的工程应用打下了良好的基础.%Nondestructive detection can be realized with the effect that the dynamic electromagnetic loading on the sheet metal can generate a stress field stimulating stress waves from the defects. The principle and implementation procedure of the electromagnetically induced acoustic emission (EMAE) is thoroughly analyzed in this paper. The high-current pulse generator which is used in the EMAE experiment is designed. The simple time-frequency analysis to the experimental signal is achieved by using fast Fourier transform (FFT). It researches the change patterns of EMAE signal with the different specimens and electromagnetic loading conditions. It verifies that it could excite the phenomenon of EMAE in the metal plate with the crack. The experimental results lay a good foundation for the engineering application of EMAE.

  8. NR-PSS (Nonlinear Robust Power System Stabilizer) for large synchronous generators and its large disturbance experiments on real time digital simulator

    Institute of Scientific and Technical Information of China (English)

    LU Qiang; ZHENG ShaoMing; MEI ShengWei; WANG Gang; HUANG QiLi

    2008-01-01

    On the foundation of nonlinear robust control and exact generator model, this paper presents a design principle of NR-PSS (Nonlinear Robust Power System Stabilizer) for multi-machine power system, based on which an industrial NR-PSS equipment is developed. For popularizing it, the proposed parameter setting method of NR-PSS is completely the same as the widely used parameter adjustment rule of PSS. By virtue of real time digital simulator (RTDS), large disturbance experiments are carried out to compare the performances between generator excitation system equipped with NR-PSS and PSS in order to verify the correctness of design theory. The results show that compared with classical PSS, the proposed NR-PSS can dramatically improve the generator damping and attenuate the oscillation much faster, enhance the generator damping and raise both the small signal and large disturbance transient stability transmission power limit remarkably. The NR-PSS equipment with independent intellectual property right has been successfully put into operation on a 300 MW generator in Baishan Hydro Plant of Northeast China Grid more than 10 months.

  9. Multipactor saturation in parallel-plate waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Sorolla, E.; Mattes, M. [Ecole Polytechnique Federale de Lausanne, Laboratoire d' Electromagnetisme et d' Acoustique (LEMA), Station 11, CH-1015 Lausanne (Switzerland)

    2012-07-15

    The saturation stage of a multipactor discharge is considered of interest, since it can guide towards a criterion to assess the multipactor onset. The electron cloud under multipactor regime within a parallel-plate waveguide is modeled by a thin continuous distribution of charge and the equations of motion are calculated taking into account the space charge effects. The saturation is identified by the interaction of the electron cloud with its image charge. The stability of the electron population growth is analyzed and two mechanisms of saturation to explain the steady-state multipactor for voltages near above the threshold onset are identified. The impact energy in the collision against the metal plates decreases during the electron population growth due to the attraction of the electron sheet on the image through the initial plate. When this growth remains stable till the impact energy reaches the first cross-over point, the electron surface density tends to a constant value. When the stability is broken before reaching the first cross-over point the surface charge density oscillates chaotically bounded within a certain range. In this case, an expression to calculate the maximum electron surface charge density is found whose predictions agree with the simulations when the voltage is not too high.

  10. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  11. Water-in-Water Emulsions Stabilized by Nanoplates

    NARCIS (Netherlands)

    Vis, Mark; Opdam, Joeri; van 't Oor, Ingo S. J.; Soligno, Giuseppe; van Roij, Rene; Tromp, R. Hans; Erne, Ben H.

    2015-01-01

    Ultrathin plate-like colloidal particles are effective candidates for Pickering stabilization of water-in-water emulsions, a stabilization that is complicated by the thickness and ultralow tension of the water-water interface. Plate-like particles have the advantage of blocking much of the interface

  12. Impact of Ternary Solvent System in Stability-Indicating Assay Method of Bambuterol: Design of Experiments Approach.

    Science.gov (United States)

    Abiramasundari, A; Joshi, Amita; Joshi, Rahul; Pandya, Dhaivat; Sharma, Jayesh; Sudarsanam, V; Vasu, Kamala K

    2016-02-01

    High-performance liquid chromatography method for anti-asthmatic β2-agonist drug bambuterol, its process-related impurities and its major degradation products was developed and validated using quality by design concept. A 3(3) full factorial design was employed to study the effect of three independent factors, namely, ratio of organic modifiers in mobile phase, pH of the buffer and flow rate of the mobile phase. The responses considered were retention time of the last peak and resolution of poorly separated peaks (drug and PR-4 and drug and DP-3). The optimum conditions for separation were determined with the aid of design of experiments. The optimized ternary solvent composition was a mixture of 10 mM ammonium acetate buffer (pH 6.0), methanol and acetonitrile in the ratio of 90:5: 5 (v/v/v) in solvent reservoir A and 10:45:45 (v/v/v) in solvent reservoir B. The separation of the analytes was achieved by using a gradient method. The predictability criteria of the optimized method demonstrated good correlation between observed and predicted response. The method was validated for specificity, linearity, accuracy, precision and robustness in compliance with the International Conference on Harmonization guidelines Q2R1.

  13. Soil organic matter (de)stabilization - new experiments needed to inform soil biogeochemistry modules in earth system models

    Science.gov (United States)

    Schmidt, Michael W. I.; Torn, Margaret S.; Riley, William J.

    2017-04-01

    To better predict soil carbon climate feedbacks, the next generation of soil biogeochemistry modules in Earth System Models (ESMs) demand new types of experiments, and a more appropriate use of existing observations. For example, we highlight soil incubations and how they have been misinterpreted when inferring pseudo-first order turnover times and decomposition temperature and moisture sensitivities. Further, for existing pseudo first-order modules, and the new microbial- and mineral-explicit generation of biogeochemistry modules, there is often a mismatch between temporal and spatial observations and how they are used by modelers. Observation periods should be longer, from annual to decadal, and include transitions, e.g., induced by climate or management. Key observations to better structure and parameterize processes that are important for carbon-climate feedbacks include i) mineral surface interactions, ii) microbial dynamics and activity, including effects of soil temperature and moisture, iii) erosion and export, iv) landscape scale process heterogeneity, and v) the effect of land use change, such as clear cut and changes in tillage. Recent insights and knowledge gaps from traditionally disconnected scientific fields (such as geophysical modeling, agricultural soil science, geomorphology, and soil biogeochemistry) will be discussed in the context of informing ESM-scale terrestrial biogeochemistry models.

  14. Towards an optimum design for electrostatic phase plates

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Andreas [Max Planck Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60438 Frankfurt (Germany); Steltenkamp, Siegfried; Schmitz, Sam; Holik, Peter [Caesar Research Center, Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany); Pakanavicius, Edvinas [University College London, Division of Biosciences, Gower Street, London WC1E 6BT (United Kingdom); Sachser, Roland; Huth, Michael [University of Frankfurt, Physikalisches Institut, Max-von-Laue-Str. 1, D-60438 Frankfurt (Germany); Rhinow, Daniel [Max Planck Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60438 Frankfurt (Germany); Kühlbrandt, Werner, E-mail: werner.kuehlbrandt@biophys.mpg.de [Max Planck Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60438 Frankfurt (Germany)

    2015-06-15

    Charging of physical phase plates is a problem that has prevented their routine use in transmission electron microscopy of weak-phase objects. In theory, electrostatic phase plates are superior to thin-film phase plates since they do not attenuate the scattered electron beam and allow freely adjustable phase shifts. Electrostatic phase plates consist of multiple layers of conductive and insulating materials, and are thus more prone to charging than thin-film phase plates, which typically consist of only one single layer of amorphous material. We have addressed the origins of charging of Boersch phase plates and show how it can be reduced. In particular, we have performed simulations and experiments to analyze the influence of the insulating Si{sub 3}N{sub 4} layers and surface charges on electrostatic charging. To optimize the performance of electrostatic phase plates, it would be desirable to fabricate electrostatic phase plates, which (i) impart a homogeneous phase shift to the unscattered electrons, (ii) have a low cut-on frequency, (iii) expose as little material to the intense unscattered beam as possible, and (iv) can be additionally polished by a focused ion-beam instrument to eliminate carbon contamination accumulated during exposure to the unscattered electron beam (Walter et al., 2012, Ultramicroscopy, 116, 62–72). We propose a new type of electrostatic phase plate that meets the above requirements and would be superior to a Boersch phase plate. It consists of three free-standing coaxial rods converging in the center of an aperture (3-fold coaxial phase plate). Simulations and preliminary experiments with modified Boersch phase plates indicate that the fabrication of a 3-fold coaxial phase plate is feasible. - Highlights: • We simulated charging artefacts of Boersch phase plates by finite element methods. • We developed methods to reduce charging, such as in-situ gas injection or charge dissipation. • We propose an optimized electrostatic phase

  15. Experimental Study of H∞ Control of Flexible Plate with Time Delay

    Directory of Open Access Journals (Sweden)

    Tong Zhao

    2013-01-01

    Full Text Available This paper presents theoretical and experimental studies of H∞ control of a flexible plate with time delay. A matrix inequality used for stability analysis is proposed and proved by using the Lyapunov-Krasovskii functional and free-weighting matrix. An H∞ controller is designed based on the matrix inequality and by using the parameter-adjusting method. Three control scenarios are discussed in detail by transforming the problem into parameters optimization: (i controller design when maximum time delay of the system is known; (ii allowable time delay when controller is known; (iii the biggest allowable time delay to guarantee system stability when controller is unknown. Numerical simulations and experiments are also given to demonstrate the validity and feasibility of the proposed methods in this paper.

  16. Modeling of reactant plate subjected to explosion shock wave based on dimensional analysis and its experiment verification%基于量纲分析的爆炸冲击波效应靶模型分析与实验研究

    Institute of Scientific and Technical Information of China (English)

    李丽萍; 孔德仁; 王芳; 商飞; 贾云飞

    2016-01-01

    In order to eliminate the interference in traditional electric measurement of shock wave pressure,a method to evaluate the shock wave pressure based on reactant plate plastic deformation was proposed.Considering the complexity of the theoretical reactant plate model with multiple parameters,the dimensional analysis was introduced to simplify the model,by which the relations between the deformation of reactant plate and TNT equivalent,mounting height and explosion distance wave obtained.Then,a calculation model of reactant plate deformation under standard TNT explosive shock wave was established.Three groups of experiments were designed to measure the reactant plate deformation under explosion shock wave of three TNT equivalents of 100 kg,60 kg and 20 kg.A regression analysis method was applied to calculate the coefficients of the empirical models for vertical and horizontal reactant plates.Through comparison of the deformations by experiments empirical models,the errors of vertical reactant plate are less than 3.59%and 3.33% respectively.The analysis provides new ideas for shock wave damage effectiveness assessment and can greatly reduce the amount of explosive experiments.%针对传统的冲击波压力电测法易受爆炸场寄生效应干扰问题,提出基于效应靶塑性变形的爆炸冲击波压力评定方法。由于效应靶理论模型复杂、参数较多,利用量纲分析方法简化模型获得爆炸冲击波压力作用的效应靶最大挠度与炸药 TNT 当量、炸高及炸距之关系,并建立冲击波压力作用的效应靶最大挠度计算模型;设计100 kg、60 kg、20 kg三种标准 TNT 爆炸的立靶、平靶实验,用回归分析法获得二者经验模型系数。结果表明,立靶与平靶两种结构效应靶最大挠度实验结果与经验模型计算结果误差分别优于3.59%及3.33%。该研究可指导战斗部冲击波压力评估,进而减少爆炸实验量。

  17. MyPlate Food Guide

    Science.gov (United States)

    ... Choosing the Right Sport for You Shyness MyPlate Food Guide KidsHealth > For Teens > MyPlate Food Guide Print ... other sugary drinks. Avoid oversized portions. continue Five Food Groups Different food groups meet different nutrition needs. ...

  18. What Are Growth Plate Injuries?

    Science.gov (United States)

    ... plate injuries are:  Falling down  Competitive sports (like football)  Recreational activities. Other reasons for growth plate injuries are:  Child abuse  Injury from extreme cold (for ...

  19. Performance and stability tests of bare high purity germanium detectors in liquid argon for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Barnabe Heider, Marik

    2009-05-27

    GERDA will search for neutrinoless double beta decay of {sup 76}Ge by using a novel approach of bare germanium detectors in liquid argon (LAr). Enriched germanium detectors from the previous Heidelberg-Moscow and IGEX experiments have been reprocessed and will be deployed in GERDA Phase-I. At the center of this thesis project is the study of the performance of bare germanium detectors in cryogenic liquids. Identical detector performance as in vacuum cryostats (2.2 keV FWHM at 1.3 MeV) was achieved in cryogenic liquids with a new low-mass detector assembly and contacts. One major result is the discovery of a radiation induced leakage current (LC) increase when operating bare detectors with standard passivation layers in LAr. Charge collection and build-up on the passivation layer were identified as the origin of the LC increase. It was found that diodes without passivation do not exhibit this feature. Three month-long stable operation in LAr at {proportional_to} 5 pA LC under periodic gamma irradiation demonstrated the suitability of the modi ed detector design. Based on these results, all Phase-I detectors were reprocessed without passivation layer and subsequently successfully characterized in LAr in the GERDA underground Detector Laboratory. The mass loss during the reprocessing was {proportional_to}300 g out of 17.9 kg and the exposure above ground {proportional_to} 5 days. This results in a negligible cosmogenic background increase of {proportional_to} 5.10{sup -4} cts/(keV.kg.y) at {sup 76}Ge Q{sub {beta}}{sub {beta}} for {sup 60}Co and {sup 68}Ge. (orig.)

  20. Flutter of flexible plate in an inhomogeneous temperature field

    Directory of Open Access Journals (Sweden)

    Baghdasaryan G.Y.

    2012-12-01

    Full Text Available There are several works devoted to the investigation of the stability of plates and shells in a supersonic gas flow. Remarks on these works in monographs [1,2] and in the paper [3] can be found. The issues of the influence of constant temperature field on the stability of deformable thin bodies in a supersonis gas flow are investigated also [4-7]. In the paper [8], in linear formulation we consider the problem of stability of long rectangular plate under the influence of both variable along the thickness temperature field and supersonic gas flow (with the unperturbed speed, which directed along the short edges of the plate. Due to the inhomogeneity of along the thickness temperature field the buckling of the plate is takes place and this state is taken as unperturbed. Conditions of stability of unperturbed state of examined termogasoelastic system are obtained and on its base the stability area is constructed in the space of variables characterizing the value of the flown speed, the temperature at the middle plane of the plate and the temperature gradient along the normal direction of this plane. It is shown that via the combined action of the temperature field and the flowing stream one can regulate the process of stability and with the help of temperature field one can significantly change the value of the flutter critical speed. In this paper, the problem, posed in [8], considered in nonlinear formulation. The effect of temperature field on the dependence of "amplitude-speed" is studied. It is shown that: a in the case of relatively thick plates if gradually increase the speed flowing stream , the flutter type vibrations persist up to ( – is the upper critical speed, the value of which depends on the temperature of the mid-plane of the plate, where the oscillations "pluck" and restored the undisturbed state of the plate. By reducing the speed the unperturbed state becomes stable up to ( – is the lower critical speed. For the amplitude of

  1. Controlling Laminate Plate Elastic Behavior

    OpenAIRE

    Mareš, T.

    2004-01-01

    This paper aims to express the relation of a measure of laminate plate stiffness with respect to the fiber orientation of its plies. The inverse of the scalar product of the lateral displacement of the central plane and lateral loading of the plate is the measure of laminate plate stiffness. In the case of a simply supported rectangular laminate plate this measure of stiffness is maximized, and the optimum orientation of its plies is searched.

  2. Microchannel plate streak camera

    Science.gov (United States)

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  3. Electronic Equipment Cold Plates

    Science.gov (United States)

    1976-04-01

    equations for such a flow regiae. For laainar flow and Moderate teaperature differwwe« between the well «nd coolant, a aodifled Sieder -Tate...con- figuration. The heat-transfer coefficients, therefore, were determined by using both the Sieder -Tate and McAdams equations and the coaputed...values used In the analytical predictions. As with th* previous cold Plates, the Sieder -Tate equation gave too low of values for the heat- transfer

  4. Elastic plate spallation

    Science.gov (United States)

    Oline, L.; Medaglia, J.

    1972-01-01

    The dynamic finite element method was used to investigate elastic stress waves in a plate. Strain displacement and stress strain relations are discussed along with the stiffness and mass matrix. The results of studying point load, and distributed load over small, intermediate, and large radii are reported. The derivation of finite element matrices, and the derivation of lumped and consistent matrices for one dimensional problems with Laplace transfer solutions are included. The computer program JMMSPALL is also included.

  5. Plate Tearing by a Cone

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1997-01-01

    The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisaton of the damage, which...

  6. Plate Tearing by a Cone

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisation of the damage, which...

  7. INVESTIGATION OF THE COMPOSITE LAMINATED BEAMS WITH TRAPEZOIDAL CORRUGATED PLATE STIFFNESS AND STABILITY EQUIVALENT ANALYSIS METHOD%复合材料层压梁梯形波纹腹板刚度和稳定性等效分析方法研究

    Institute of Scientific and Technical Information of China (English)

    秋洪燕; 矫桂琼; 黄涛

    2012-01-01

    对含梯形波纹腹板的复合材料层压梁结构进行有限元建模方法研究,并将该方法应用于某层压梁结构刚度和稳定性分析中;建立不同工况下结构的有限元模型,得到其刚度和临界屈曲载荷值.同时提出一种新的复合材料波纹腹板层压梁刚度和稳定性等效分析方法.与传统对波纹板结构细化的有限元建模方法相比较,运用该等效优化分析方法对含波纹板结构的分析效率明显提高.对结构刚度和屈曲载荷进行曲线拟合,有限元分析结果数据点与拟合预测曲线吻合较好.%The finite element analysis (FEA) method was used to study on the stiffness and stability of a laminated beam with trapezoidal corrugated plate. Variety FE models were created under different work conditions to investigate the stiffness and critical buckling load of the structure. The method of equivalent analysis was proposed for the FE analysis. It was proved that the new method is more efficient than the traditional FE method for the beam structure with corrugated plate. The stiffness and buckling load of the structure have carried on the curve fitting, and the FEA results agree well with the predictions.

  8. Resistive Plate Chamber Efficiency & Rate Capability Analysis

    Science.gov (United States)

    Candocia, Max

    2012-10-01

    Bakelite-based resistive plate chambers (RPCs) are particle detectors commonly used in muon trigger systems for high-energy physics experiments. Bakelite RPCs combine fast response, sufficient position resolution and low cost, and they can be operated at instantaneous background rates up to approximately 1.5 kHz/cm^2. Current and future collider experiments will demand operation of trigger RPCs under background rates higher than what is currently achieved. The rate capability is related to the bulk and surface conductivities of the Bakelite material used for the plates bordering the active gas volume in the RPCs. At the LHC and RHIC, these surfaces are coated with linseed oil, which lowers the surface resistivity of the Bakelite, which, to a point, improves the rate capability of the detectors. We have doped our own plates with various concentrations of carbon black. Over the past year we have tested RPCs with Bakelite plates of different resistivity using cosmic ray muons and radioactive Fe55 sources to emulate different levels of background in the detector. Results on the RPC efficiencies at different background rates and for different Bakelite coatings will be presented.

  9. Plate and shell theory

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1997-01-01

    Fundamental analytical methods for the calculation of the bending strength and stability of isotrop and stiffened panels typically used in ship structures.Practical working examples with references to the rules of ship classification societies....

  10. Plate tectonics conserves angular momentum

    Directory of Open Access Journals (Sweden)

    C. Bowin

    2009-03-01

    Full Text Available A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4 E+27 kgm2s−1. Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates. Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth. The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant velocity on the crests of convection cells driven by rising heat. These results imply that spreading centers are primarily passive reactive

  11. Vehicle License Plate Recognition Syst

    Directory of Open Access Journals (Sweden)

    Meenakshi,R. B. Dubey

    2012-12-01

    Full Text Available The vehicle license plate recognition system has greater efficiency for vehicle monitoring in automatic zone access control. This Plate recognition system will avoid special tags, since all vehicles possess a unique registration number plate. A number of techniques have been used for car plate characters recognition. This system uses neural network character recognition and pattern matching of characters as two character recognition techniques. In this approach multilayer feed-forward back-propagation algorithm is used. The performance of the proposed algorithm has been tested on several car plates and provides very satisfactory results.

  12. Using plate mapping to examine portion size and plate composition for large and small divided plates.

    Science.gov (United States)

    Sharp, David E; Sobal, Jeffery; Wansink, Brian

    2014-12-01

    Does the size of a plate influence the serving of all items equally, or does it influence the serving of some foods - such as meat versus vegetables - differently? To examine this question, we used the new method of plate mapping, where people drew a meal on a paper plate to examine sensitivity to small versus large three-compartment divided plates in portion size and meal composition in a sample of 109 university students. The total drawn meal area was 37% bigger on large plates than small plates, which showed that the portion of plate coverage did not differ by plate size. Men and women drew bigger vegetable portions and men drew bigger meat portions on large plates when compared to small plates. These results suggest that men and women are differentially sensitive to plate size for overall meal size and for meal composition. Implications for decreasing portion size and improving meal balance are that plate size may influence portion size and change the proportions of foods served.

  13. Linear optical pulse compression based on temporal zone plates.

    Science.gov (United States)

    Li, Bo; Li, Ming; Lou, Shuqin; Azaña, José

    2013-07-15

    We propose and demonstrate time-domain equivalents of spatial zone plates, namely temporal zone plates, as alternatives to conventional time lenses. Both temporal intensity zone plates, based on intensity-only temporal modulation, and temporal phase zone plates, based on phase-only temporal modulation, are introduced and studied. Temporal zone plates do not exhibit the limiting tradeoff between temporal aperture and frequency bandwidth (temporal resolution) of conventional linear time lenses. As a result, these zone plates can be ideally designed to offer a time-bandwidth product (TBP) as large as desired, practically limited by the achievable temporal modulation bandwidth (limiting the temporal resolution) and the amount of dispersion needed in the target processing systems (limiting the temporal aperture). We numerically and experimentally demonstrate linear optical pulse compression by using temporal zone plates based on linear electro-optic temporal modulation followed by fiber-optics dispersion. In the pulse-compression experiment based on temporal phase zone plates, we achieve a resolution of ~25.5 ps over a temporal aperture of ~5.77 ns, representing an experimental TBP larger than 226 using a phase-modulation amplitude of only ~0.8π rad. We also numerically study the potential of these devices to achieve temporal imaging of optical waveforms and present a comparative analysis on the performance of different temporal intensity and phase zone plates.

  14. Dynamic buckling of stiffened plates subjected to explosion impact loads

    Science.gov (United States)

    Wang, J.; Guo, J.; Yao, X. L.; Zhang, A. M.

    2017-01-01

    The dynamic buckling characteristics and criteria of a ship's structural stiffened plate subjected to underwater explosion impact loads are investigated in this study. Using the structural deformations observed in the experiments of underwater explosions against a plated grillage model, the mode shapes of the dynamic buckling were obtained. Through the construction of a computational model of stiffened plates subjected to an underwater explosion shock wave, the impact load was theoretically calculated and transformed into a rectangular pulse. According to the different response patterns of stiffened plates under different impact loads, a dynamic buckling criterion for the stiffened plates subjected to an explosion shock wave was proposed. Additionally, the static buckling phenomenon in the stiffened plates was analysed based on the minimum excess principle. In combination with the dynamic buckling criterion, the effects of various stiffening configurations on the dynamic and static buckling loads are discussed. The calculation results show that when the equivalent rectangular pulse is 2-3 times that of the static buckling load, the responses of the stiffened plates under the original shock load and the equivalent rectangular pulse are virtually identical. The impact load amplitude is the primary influencing factor in the dynamic buckling of stiffened plates subjected to underwater explosive impact loads. The stiffened plate aspect ratio has a substantial influence on the dynamic load factor. The analytical method and results are presented, which can be used to design stiffened optimum hull structures to enhance the dynamic load carrying capacity to withstand underwater shock damage.

  15. Thermal buckling analysis of truss-core sandwich plates

    Institute of Scientific and Technical Information of China (English)

    陈继伟; 刘咏泉; 刘伟; 苏先樾

    2013-01-01

    Truss-core sandwich plates have received much attention in virtue of the high values of strength-to-weight and stiffness-to-weight as well as the great ability of impulse-resistance recently. It is necessary to study the stability of sandwich panels under the influence of the thermal load. However, the sandwich plates are such complex three-dimensional (3D) systems that direct analytical solutions do not exist, and the finite element method (FEM) cannot represent the relationship between structural parameters and mechanical properties well. In this paper, an equivalent homogeneous continuous plate is idealized by obtaining the effective bending and transverse shear stiffness based on the characteristics of periodically distributed unit cells. The first order shear deformation theory for plates is used to derive the stability equation. The buckling temperature of a simply supported sandwich plate is given and verified by the FEM. The effect of related parameters on mechanical properties is investigated. The geometric parameters of the unit cell are optimized to attain the maximum buckling temperature. It is shown that the optimized sandwich plate can improve the resistance to thermal buckling significantly.

  16. Outdoor Field Experience with Autonomous Stations

    CERN Document Server

    Lopes, L; Blanco, A; Carolino, N; Cerda, M A; Conceicao, R; Cunha, O; Ferreira, M; Fonte, P; Luz, R; Mendes, L; Pereira, A; Pimenta, M; Sarmento, R; Tome, B

    2016-01-01

    In the last two decades Resistive Plate Chambers were employed in the Cosmic Ray Experiments COVER-PLASTEX and ARGO/YBJ. In both experiments the detectors were housed indoors, likely owing to gas distribution requirements and the need to control environment variables that directly affect RPCs operational stability. But in experiments where Extended Air Shower (EAS) sampling is necessary, large area arrays composed by dispersed stations are deployed, rendering this kind of approach impossible. In this situation, it would be mandatory to have detectors that could be deployed in small standalone stations, with very rare opportunities for maintenance, and with good resilience to environmental conditions. Aiming to meet these requirements, we started some years ago the development of RPCs for Autonomous Stations. The results from indoor tests and measurements were very promising, both concerning performance and stability under very low gas flow rate, which is the main requirement for Autonomous Stations. In this w...

  17. An adjustable parallel-plate capacitor instrument—Test of the theoretical capacitance formula

    Science.gov (United States)

    Wells, Beau; Baker, Emily; Farwell, Austin; Foster, Harrison; Gao, Xiaohan; Gruber, Benjamin; Jones, Erica; Vu, Dennis; Xu, Sonya; Ye, Jingbo

    2016-09-01

    We describe an adjustable parallel-plate capacitor apparatus designed for use in an undergraduate laboratory that permits precise variation of plate separation distances and overlap area. Two experiments are performed with the device to test the ideal capacitor formula derived from Gauss's Law. After correcting for edge effects and minor plate tilt, the device yields capacitance values within 3% of theoretical values.

  18. General Analytical Solution of Transverse Vibration For Orthotropic Rectangular Thin Plates

    Institute of Scientific and Technical Information of China (English)

    HUANG; Yan; ZHANG; Xiao-jin

    2002-01-01

    A general solution of differential equation for transverse displacement function of orthotropic rectangular thin plates in free vibration is established in this paper. It can be used to solve the vibration problem of plate with arbitrary boundaries. As an example, the frequencies of a composite laminated plate with four free edges have been solved. The result as compared with the experiment is satisfactory.

  19. Plate reactor as an analysis tool for rapid pyrolysis of biomass

    NARCIS (Netherlands)

    Sepman, A. V.; de Goey, L. P. H.

    2011-01-01

    This work presents a study of the performance of the modified plate reactor by rapid pyrolysis experiments with different biomass samples (MDF, bark pine and Avicel cellulose). The use of the plate instead of a grid allowed us to achieve a more homogeneous temperature distribution across the plate a

  20. Experimental and numerical study of the wave run-up along a vertical plate

    DEFF Research Database (Denmark)

    Molin, Bernard; Kimmoun, O.; Liu, Y.;

    2010-01-01

    Results from experiments on wave interaction with a rigid vertical plate are reported. The 5m long plate is set against the wall of a 30m wide basin, at 100m from the wavemaker. This set-up is equivalent to a 10m plate in the middle of a 60m wide basin. Regular waves are produced, with wavelengths...

  1. BUCKLING ANALYSIS UNDER COMBINED LOADING OF THIN-WALLED PLATE ASSEMBLIES USING BUBBLE FUNCTIONS

    Institute of Scientific and Technical Information of China (English)

    Gao Xuanneng; Zou Yinsheng; Zhou Xuhong

    2000-01-01

    Bubble functions are finite element modes that are zero on the boundary of the element but nonzero at the other point. The present paper adds bubble functions to the ordinary Complex Finite Strip Method(CFSM) to calculate the elastic local buckling stress of plates and plate assemblies. The results indi cate that the use of bubble functions greatly improves the convergence of the Finite Strip Method(FSM) in terms of strip subdivision, and leads to much smaller storage required for the structure stiffness and stability matrices. Numerical examples are given, including plates and plate structures subjected to a combination of longitudinal and transverse compression, bending and shear. This study illustrates the power of bubble func tions in solving stability problems of plates and plate structures.

  2. Proximal Humeral Fractures: A Biomechanical Comparison of Locking Plate Constructs in a Cadaveric 3-Part Fracture Model

    OpenAIRE

    2010-01-01

    The purpose of our study was to biomechanically compare, under cyclic loading conditions, fracture site motion, humeral head collapse, and intra-articular hardware penetration in simulated 3-part osteoporotic proximal humeral fractures stabilized with 1 of 2 locking-plate constructs. We performed fixation on simulated 3-part proximal humeral fractures in 10 pairs of cadaveric osteoporotic humeri with a Hand Innovations S3 Proximal Humerus Plate (S3 plate) or an LCP Proximal Humerus Plate (LCP...

  3. Methods for testing Zernike phase plates and a report on silicon-based phase plates with reduced charging and improved ageing characteristics.

    Science.gov (United States)

    Marko, Michael; Meng, Xing; Hsieh, Chyongere; Roussie, James; Striemer, Christopher

    2013-11-01

    Imaging with Zernike phase plates is increasingly being used in cryo-TEM tomography and cryo-EM single-particle applications. However, rapid ageing of the phase plates, together with the cost and effort in producing them, present serious obstacles to widespread adoption. We are experimenting with phase plates based on silicon chips that have thin windows; such phase plates could be mass-produced and made available at moderate cost. The windows are coated with conductive layers to reduce charging, and this considerably extends the useful life of the phase plates compared to traditional pure-carbon phase plates. However, a compromise must be reached between robustness and transmission through the phase-plate film. Details are given on testing phase-plate performance by means of imaging an amorphous thin film and evaluating the power spectra of the images.

  4. Temperature field of steel plate cooling process after plate rolling

    Directory of Open Access Journals (Sweden)

    Huijun Feng, Lingen Chen, Fengrui Sun

    2015-01-01

    Full Text Available Based on numerical calculation with Matlab, the study on cooling process after plate rolling is carried out, and the temperature field distribution of the plate varying with the time is obtained. The effects of the plate thickness, final rolling temperature, cooling water temperature, average flow rate of the cooling water, carbon content of the plate and cooling method on the plate surface and central temperatures as well as final cooling temperature are discussed. For the same cooling time, the plate surface and central temperatures as well as their temperature difference increase; with the decrease in rolling temperature and the increase in average flow rate of the cooling water, the plate surface and central temperatures decrease. Compared with the single water cooling process, the temperature difference between the plate centre and surface based on intermittent cooling is lower. In this case, the temperature uniformity of the plate is better, and the corresponding thermal stress is lower. The fitting equation of the final cooling temperature with respect to plate thickness, final rolling temperature, cooling water temperature and average flow rate of the cooling water is obtained.

  5. Real Plates and Dubious Microplates

    Science.gov (United States)

    Kogan, M. G.; Steblov, G. M.

    2008-12-01

    From the onset of plate tectonics, the existence of most of the plates was never put in doubt, although the boundaries of some plates, like Africa, were later revised. There are however, two microplates in northeast Asia, the Amurian and Okhotsk, whose existence and the sense of rotation was revised several times. The rms value of plate-residual GPS velocities is 0.5-0.9 mm/a for sets of stations representing the motion of the following plates: Antarctic, Australian, Eurasian, North American, Nubian, Pacific, and South American. This value can be regarded as an upper bound on deviation of real plates from infinite stiffness. The rms value of plate-residual GPS velocities is 1.2-1.8 mm/a for the Indian, Nazca, and Somalian plates. Higher rms values for India and Nazca are attributed to the noisier data. The higher rms value for Somalia appears to arise from the distributed deformation to the east of the East African Rift; whether this statement is true can only be decided from observations of denser network in the future. From the analysis of plate-residual GPS velocities, the Canadian Arctic and northeastern Siberia belong to the North American plate. The detailed GPS survey on Sakhalin Island shows that the Sea of Okhotsk region also belongs to the North American plate while the region to the west of it belongs to the Eurasian plate. These results provide a constraint on the geometry of the North American plate and put in doubt the existence of smaller plates in northeast Asia.

  6. Initial stage of flat plate impact onto liquid free surface

    Science.gov (United States)

    Iafrati, Alessandro; Korobkin, Alexander A.

    2004-07-01

    The liquid flow and the free surface shape during the initial stage of flat plate impact onto liquid half-space are investigated. Method of matched asymptotic expansions is used to derive equations of motion and boundary conditions in the main flow region and in small vicinities of the plate edges. Asymptotic analysis is performed within the ideal and incompressible liquid model. The liquid flow is assumed potential and two dimensional. The ratio of the plate displacement to the plate width plays the role of a small parameter. In the main region the flow is given in the leading order by the pressure-impulse theory. This theory provides the flow field around the plate after a short acoustic stage and predicts unbounded velocity of the liquid at the plate edges. In order to resolve the singular flow caused by the normal impact of a flat plate, the fine pattern of the flow in small vicinities of the plate edges is studied. It is shown that the initial flow close to the plate edges is self-similar in the leading order and is governed by nonlinear boundary-value problem with unknown shape of the free surface. The Kutta conditions are imposed at the plate edges, in order to obtain a nonsingular inner solution. This boundary-value problem is solved numerically by iterations. At each step of iterations the "inner" velocity potential is calculated by the boundary-element method. The asymptotics of the inner solution in both the far field and the jet region are obtained to make the numerical algorithm more efficient. The numerical procedure is carefully verified. Agreement of the computed free surface shape with available experimental data is fairly good. Stability of the numerical solution and its convergence are discussed.

  7. A MEMS square Chladni plate resonator

    Science.gov (United States)

    Pala, Sedat; Azgın, Kıvanç

    2016-10-01

    This paper presents the design, fabrication and tests of a micro-fabricated MEMS ‘Chladni’ plate resonator. The proposed MEMS resonator has a square plate geometry having a side length of 1400 µm and a height of 35 µm. Its geometry and electrode layout are designed to analyze and test as many modes as possible. The MEMS plate is fabricated using a silicon-on-insulator process with a 35 µm thick silicon layer on a glass substrate. Transverse vibration of the plate is investigated to obtain closed form natural frequencies and mode shapes, which are derived using the Rayleigh-Ritz energy method, with an electrostatic softening effect included. Closed form equations for the calculation of effective stiffness’, masses and natural frequencies of the two modes (mode (1,1) and mode (2,0)-(0,2)) are presented, with and without electrostatic softening. The analytical model is verified for those modes by finite-element simulations, frequency response tests in vacuum and laser Doppler vibrometer (LDV) experiments. The derived model deviates from the finite-element analysis by 3.35% for mode (1,1) and 6.15% for mode (2,0)-(0,2). For verification, the frequency responses of the plates are measured with both electrostatic excitation-detection at around 20 mTorr vacuum ambient and LDV at around 0.364 mTorr vacuum ambient. The resonance frequency and Q-factor of mode (1,1) are measured to be 104.2 kHz and 14 300, respectively. For mode (2,0)-(0,2), the measured resonance frequency and Q-factor are 156.68 kHz and 10 700, respectively. The presented LDV results also support both natural frequencies of interest and corresponding mode shapes of the plate structure.

  8. The Light Velocity Casimir Effect Does the Velocity of Light Increase when Propagating Between the Casimir Plates?

    CERN Document Server

    Ostoma, T; Ostoma, Tom; Trushyk, Mike

    1999-01-01

    We propose experiments that might be set up to detect the increase in the velocity of light in a vacuum in the laboratory frame for photons travelling between (and perpendicular to) the Casimir plates in a vacuum. The Casimir plates are two closely spaced, conductive plates, where an attractive force is observed to exist between the plates called the 'Casimir Force'. We propose that the velocity of light in a vacuum increases when propagating between two transparent Casimir Plates. We call this effect the 'Light Velocity Casimir Effect' or LVC effect. The LVC effect happens because the vacuum energy density in between the plates is lower than that outside the Casimir plates. The conductive plates disallow certain frequencies of electrically charged virtual particles to exist inside the plates, thus lowering the inside vacuum particle density, compared to the density outside the plates. The reduced (electrically charged) virtual particle density results in fewer photon scattering events inside the plates, whic...

  9. Plate Full of Color

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Plate Full of Color teaches the value of eating a variety of colorful and healthy foods.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  10. Dynamics of Tectonic Plates

    CERN Document Server

    Pechersky, E; Sadowski, G; Yambartsev, A

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces.

  11. Dynamics of Tectonic Plates

    OpenAIRE

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend ...

  12. Adult periarticular locking plates for the treatment of pediatric and adolescent subtrochanteric hip fractures.

    Science.gov (United States)

    Sanders, Samuel; Egol, Kenneth A

    2009-01-01

    Two cases are presented in which adult, precontoured, lower-extremity periarticular locking plates were utilized for fixation of subtrochanteric femur fractures in pediatric patients. Recognition of the fact that a distal tibial locking plate in a small child and a proximal tibial locking plate in an adolescent anatomically ft the proximal femur in each case may provide a surgeon treating subtrochanteric hip fractures in this population increased options for operative stabilization.

  13. Aeroelastic Tailoring of a Plate Wing with Functionally Graded Materials

    Science.gov (United States)

    Dunning, Peter D.; Stanford, Bret K.; Kim, H. Alicia; Jutte, Christine V.

    2014-01-01

    This work explores the use of functionally graded materials for the aeroelastic tailoring of a metallic cantilevered plate-like wing. Pareto trade-off curves between dynamic stability (flutter) and static aeroelastic stresses are obtained for a variety of grading strategies. A key comparison is between the effectiveness of material grading, geometric grading (i.e., plate thickness variations), and using both simultaneously. The introduction of material grading does, in some cases, improve the aeroelastic performance. This improvement, and the physical mechanism upon which it is based, depends on numerous factors: the two sets of metallic material parameters used for grading, the sweep of the plate, the aspect ratio of the plate, and whether the material is graded continuously or discretely.

  14. A COMBINED HYBRID FINITE ELEMENT METHOD FOR PLATE BENDING PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Tian-xiao Zhou; Xiao-ping Xie

    2003-01-01

    In this paper, a combined hybrid method is applied to finite element discretization ofplate bending problems. It is shown that the resultant schemes are stabilized, i.e., theconvergence of the schemes is independent of inf-sup conditions and any other patch test.Based on this, two new series of plate elements are proposed.

  15. Point of Impact Prediction in Anisotropic Fiber Reinforced Composite Plates from the Acoustic Emission Data

    Science.gov (United States)

    Kundu, T.; Das, S.; Jata, K. V.

    2008-02-01

    A newly developed optimization based method is followed to locate the point of impact in anisotropic composite plates for which conventional triangulation technique fails. The new technique works for both anisotropic and isotropic plates. Experiments are carried out by dropping a steel ball on a graphite-epoxy composite plate and picking up acoustic signals by passive transducers adhesively bonded to the plate at different locations. Predicted points of impact are compared with the true impact point.

  16. The biomechanical study of medial cortex defect on axial stability of proximal humeral fracture fixed with locking plate%内侧皮质缺损对肱骨近端骨折锁定钢板内固定轴向稳定性影响的生物力学研究

    Institute of Scientific and Technical Information of China (English)

    白露; 张文涛; 江长青; 张洪雷; 黄伟; 张新涛; 李伟

    2014-01-01

    Background Proximal humeral fracture is a common injury of shoulder girdle. Currently,locking plate was widely used in management of proximal humeral fractures.Known as“internal fixator”,locking plate can provide more purchase in osteoporosis humeral head,bearing more biomechanical advantages.However,some large series of clinical research showed varus deformity became one of the main complication of proximal humeral fractures treated with locking plate that caused by axial instability.Multi-center trail found that medial cortex defect of proximal metaphyseal of humerus was an independent risk factor of reduction loss and varus malunion.Furthermore,such pathophysiological biomechanic basis was still vague.Our research was planned to study the relationship between medial cortex defect and axial stability of locking plate fixed proximal humeral fracture,in order to find inner rule of how medial cortex defect affect locking plate fixation of proximal humeral fracture.Methods Eighteen adult humerus specimen(6 pairs male),average death age 63.4 years(49-73).All the specimen were excluded bone tumor and occult fracture.Fracture model were prepared at X-Y table.Specimen were cut to 200mm from proximal to shaft.Fracture line was cut at surgical neck perpendicular to humeral shaft.Five millimeter medial cortex defect were also created by T-Saw.All the specimen were fixed using Synthesis PHILOS (Proximal Humerus Internal Osteosythesis System)following AO fixation rules.Specimens were randomized into contrast group, medial cortex half defect group and medial cortex quarter defect group.Axial compression and shear test were done in RGM-40XX2100 machine (Load scale 10 kN,± 1% ).Mechanical Load:Preload:50N,Velocity:5 mm/min,Maximum displacement:5 mm.In axial compression and shear tests,the slope of the load de ection curve was used to compute baseline axial stiffness.Each test was repeated three times and average stiffness was calculated.Statistical analyses were performed

  17. Functional results of osteosynthesis with mini-plate and screws in metacarpal fractures

    Directory of Open Access Journals (Sweden)

    Hakan Başar

    2014-01-01

    Conclusions: Mini-plate and screws fixation of unstable metacarpal fractures produces anatomical reduction of fractures with stabilization that is rigid enough to allow early mobilization, thereby preventing stiffness and hence good functional results.

  18. Development and progress in resistive plate chamber

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-Fang; WU Jian

    2004-01-01

    Resistive Plate Chamber (RPC) is a robust and low cost gas detector, which is extensively used in high-energy physics, cosmic and astroparticle physics experiments. Over the past twenty years, as a particle detector,RPC has made remarkable progress. The main achievements, features and results of experiemantal tests including R&D and production of the RPCs by several Chinese groups in recent years are reported in this article.

  19. Functional activity of plasmid DNA after entry into the atmosphere of earth investigated by a new biomarker stability assay for ballistic spaceflight experiments.

    Directory of Open Access Journals (Sweden)

    Cora S Thiel

    Full Text Available Sounding rockets represent an excellent platform for testing the influence of space conditions during the passage of Earth's atmosphere and re-entry on biological, physical and chemical experiments for astrobiological purposes. We designed a robust functionality biomarker assay to analyze the biological effects of suborbital spaceflights prevailing during ballistic rocket flights. During the TEXUS-49 rocket mission in March 2011, artificial plasmid DNA carrying a fluorescent marker (enhanced green fluorescent protein: EGFP and an antibiotic resistance cassette (kanamycin/neomycin was attached on different positions of rocket exterior; (i circular every 90 degree on the outer surface concentrical of the payload, (ii in the grooves of screw heads located in between the surface application sites, and (iii on the surface of the bottom side of the payload. Temperature measurements showed two major peaks at 118 and 130 °C during the 780 seconds lasting flight on the inside of the recovery module, while outer gas temperatures of more than 1000 °C were estimated on the sample application locations. Directly after retrieval and return transport of the payload, the plasmid DNA samples were recovered. Subsequent analyses showed that DNA could be recovered from all application sites with a maximum of 53% in the grooves of the screw heads. We could further show that up to 35% of DNA retained its full biological function, i.e., mediating antibiotic resistance in bacteria and fluorescent marker expression in eukaryotic cells. These experiments show that our plasmid DNA biomarker assay is suitable to characterize the environmental conditions affecting DNA during an atmospheric transit and the re-entry and constitute the first report of the stability of DNA during hypervelocity atmospheric transit indicating that sounding rocket flights can be used to model the high-speed atmospheric entry of organics-laden artificial meteorites.

  20. Reaction-induced rheological weakening enables oceanic plate subduction

    Science.gov (United States)

    Hirauchi, Ken-Ichi; Fukushima, Kumi; Kido, Masanori; Muto, Jun; Okamoto, Atsushi

    2016-08-01

    Earth is the only terrestrial planet in our solar system where an oceanic plate subducts beneath an overriding plate. Although the initiation of plate subduction requires extremely weak boundaries between strong plates, the way in which oceanic mantle rheologically weakens remains unknown. Here we show that shear-enhanced hydration reactions contribute to the generation and maintenance of weak mantle shear zones at mid-lithospheric depths. High-pressure friction experiments on peridotite gouge reveal that in the presence of hydrothermal water, increasing strain and reactions lead to an order-of-magnitude reduction in strength. The rate of deformation is controlled by pressure-solution-accommodated frictional sliding on weak hydrous phyllosilicate (talc), providing a mechanism for the `cutoff' of the high peak strength at the brittle-plastic transition. Our findings suggest that infiltration of seawater into transform faults with long lengths and low slip rates is an important controlling factor on the initiation of plate tectonics on terrestrial planets.

  1. THE EFFECT OF SUPPORT PLATE ON DRILLING-INDUCED DELAMINATION

    Directory of Open Access Journals (Sweden)

    Navid Zarif Karimi

    2016-02-01

    Full Text Available Delamination is considered as a major problem in drilling of composite materials, which degrades the mechanical properties of these materials. The thrust force exerted by the drill is considered as the major cause of delamination; and one practical approach to reduce delamination is to use a back-up plate under the specimen. In this paper, the effect of exit support plate on delamination in twist drilling of glass fiber reinforced composites is studied. Firstly, two analytical models based on linear fracture mechanics and elastic bending theory of plates are described to find critical thrust forces at the beginning of crack growth for drilling with and without back-up plate. Secondly, two series of experiments are carried out on glass fiber reinforced composites to determine quantitatively the effect of drilling parameters on the amount of delamination. Experimental findings verify a large reduction in the amount of delaminated area when a back-up plate is placed under the specimen.

  2. Prediction of the point of impact in an anisotropic plate

    Science.gov (United States)

    Koabaz, M.; Hajzargarbashi, T.; Kundu, T.; Deschamps, M.

    2011-01-01

    Locating the point of impact of a foreign object in a plate is important for continuous health monitoring of structures. A new method based on an optimization scheme has been recently proposed to locate the point of impact in anisotropic plates by analyzing the times of arrival of the ultrasonic signals at the passive sensors attached to the plate. Following this optimization based technique, in this paper the impact point on an anisotropic plate is predicted from the acoustic emission data. Experiments are carried out with a carbon-epoxy plate where the impact point is modeled by an acoustic source. A Parallel Pre-stressed Actuator (PPA) is used as the acoustic source and the acoustic signals at different locations are received by adhesively bonded acoustic sensors. The source point is then predicted and compared with its actual location. Related theory is also presented in the paper.

  3. Wave Damping over a Perforated Plate with Water Chambers

    Institute of Scientific and Technical Information of China (English)

    ZHU Shutang

    2006-01-01

    The movement of waves propagating over a horizontally submerged perforated plate with waterfilled chambers bellow the plate was investigated by using linear potential theory. The analytical solution was compared with laboratory experiments on wave blocking. The analysis of the wave energy dissipation on the perforated bottom surface shows that the effects of the perforated plate on thewave motion depend mainly on the plate porosity, the wave height, and the wave period. The wave number is a complex number when the wave energy dissipation on the perforated plate is considered. The real part of the wave number refers to the spatial periodicity while the imaginary part represents the damping modulus. The characteristics of the wave motion were explored for several possible conditions.

  4. [Angle-fixed plate fixation or double-plate osteosynthesis in fractures of the proximal humerus: a biomechanical study].

    Science.gov (United States)

    Hessmann, Martin H; Korner, Jan; Hofmann, Alexander; Sternstein, Werner; Rommens, Pol M

    2008-06-01

    Internal fixation of fractures of the proximal humerus needs a high stability of fixation to avoid secondary loss of fixation. This is especially important in osteoporotic bone. In an experimental study, the biomechanical properties of the angle-fixed Philos plate (internal fixator) and a double-plate osteosynthesis using two one-third tubular plates were assessed. The fracture model was an unstable three-part fracture (AO type B2). Eight pairs of human cadaveric humeri were submitted to axial load and torque. In the first part of the study, it was assessed to which degree the original stiffness of the humeri could be restored after the osteotomy by the osteosynthesis procedure. Subsequently, subsidence during 200 cycles of axial loading and torque was analysed. During axial loading, the Philos plate was significantly stiffer and showed less irreversible deformation. Two double-plate fixations, but none of the Philos plate osteosynthesis, failed. During torsion, there were no significant differences between the two implants. From the biomechanical point of view, the angle-fixed Philos plate represents the implant of choice for the surgical fixation of highly unstable three-part fractures of the proximal humerus, as the internal fixator system is characterised by superior biomechanical properties.

  5. Localised Plate Motion on Venus

    Science.gov (United States)

    Ghail, R. C.

    1996-03-01

    The volcanic and tectonic features observed in Dali Vinculum, Parga Vinculum and Imdr Regio are concentrated at long, narrow, curvilinear zones, with relatively minor volcanism and tectonism between these zones. These zones, whilst more diffuse than terrestrial plate boundaries, nevertheless define the margins of tectonic plates. In contrast to Earth, however, it appears that venusian plates are neither created nor destroyed by lateral motion. Rather, plates are thinned and intruded at vincula plate boundaries, vertically accreted by small-scale intra-plate (planitia) volcanism and perhaps destroyed by delamination of thickened crust in tesserae and montane regions such as Thetis Regio and Ishtar Terra. The diversity in age both between and within these three areas together with the evidence for infrequent, small scale resurfacing in the planitiae are difficult to reconcile with a non-uniformitarian geological process.

  6. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  7. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  8. Hot Isostatic Press Can Optimization for Aluminum Cladding of U-10Mo Reactor Fuel Plates: FY12 Final Report and FY13 Update

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Kester D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crapps, Justin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scott, Jeffrey E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aikin, Beverly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vargas, Victor D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Duffield, Andrew N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weinberg, Richard Y. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alexander, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hudson, Richard W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mihaila, Bogdan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Liu, Cheng [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lovato, Manuel L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dombrowski, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-08-26

    Currently, the proposed processing path for low enriched uranium – 10 wt. pct. molybdenum alloy (LEU-10Mo) monolithic fuel plates for high power research and test reactors includes hot isostatic pressing (HIP) to bond the aluminum cladding that encapsulates the fuel foil. Initial HIP experiments were performed at Idaho National Laboratory (INL) on approximately ¼ scale “mini” fuel plate samples using a HIP can design intended for these smaller experimental trials. These experiments showed that, with the addition of a co-rolled zirconium diffusion barrier on the LEU-10Mo alloy fuel foil, the HIP bonding process is a viable method for producing monolithic fuel plates. Further experimental trials at Los Alamos National Laboratory (LANL) effectively scaled-up the “mini” can design to produce full-size fuel prototypic plates. This report summarizes current efforts at LANL to produce a HIP can design that is further optimized for higher volume production runs. The production-optimized HIP can design goals were determined by LANL and Babcock & Wilcox (B&W) to include maintaining or improving the quality of the fuel plates produced with the baseline scaled-up mini can design, while minimizing material usage, improving dimensional stability, easing assembly and disassembly, eliminating machining, and significantly reducing welding. The initial small-scale experiments described in this report show that a formed-can approach can achieve the goals described above. Future work includes scaling the formed-can approach to full-size fuel plates, and current progress toward this goal is also summarized here.

  9. Aluminum Manganese Molten Salt Plating

    Science.gov (United States)

    2006-06-01

    Dry fixture thoroughly with the air gun. Be especially careful to dry water out of crevices. Note: water is a contaminant to the plating process...easily destroyed if blown with the air. Be especially careful to dry water out of crevices. Note: water is a contaminant to the plating process and...especially careful to dry water out of crevices. 13. Carefully remove part from fixture. If residual plating solution is present at attachments points

  10. Glass-bead peen plating

    Science.gov (United States)

    Graves, J. R.

    1974-01-01

    Peen plating of aluminum, copper, and nickel powders was investigated. Only aluminum was plated successfully within the range of peen plating conditions studied. Optimum plating conditions for aluminum were found to be: (1) bead/powder mixture containing 25 to 35% powder by weight, (2) peening intensity of 0.007A as measured by Almen strip, and (3) glass impact bead diameter of at least 297 microns (0.0117 inches) for depositing-100 mesh aluminum powder. No extensive cleaning or substrate preparation is required beyond removing loose dirt or heavy oil.

  11. On the rotation and pitching of flat plates

    Science.gov (United States)

    Jin, Yaqing; Ji, Sheng; Chamorro, Leonardo P.

    2016-11-01

    Wind tunnel experiments were performed to characterize the flow-induced rotation and pitching of various flat plates as a function of the thickness ratio, the location of the axis of rotation and turbulence levels. High-resolution telemetry, laser tachometer, and hotwire were used to get time series of the plates motions and the signature of the wake flow at a specific location. Results show that a minor axis offset can induce high-order modes in the plate rotation under low turbulence due to torque unbalance. The spectral decomposition of the flow velocity in the plate wake reveals the existence of a dominating high-frequency mode that corresponds to a static-like vortex shedding occurring at the maximum plate pitch, where the characteristic length scale is the projected width at maximum pitch. The plate thickness ratio shows inverse relation with the angular velocity. A simple model is derived to explain the linear relation between pitching frequency and wind speed. The spectra of the plate rotation show nonlinear relation with the incoming turbulence, and the dominating role of the generated vortices in the plate motions.

  12. Cold model experiment for magnetically stabilized bed reactor applied in synthesis of diphenyl carbonate by carbonylation method%磁稳定床羰基化合成碳酸二苯酯的冷模实验

    Institute of Scientific and Technical Information of China (English)

    贺玉成; 张林锋; 陈成; 袁华; 杜治平; 吴元欣

    2014-01-01

    以磁性催化剂Pd/La0.5 Pb0.5 MnO3为固相、N2为气相、纯水为液相在磁稳定床上进行冷模实验,探索磁稳定床的流动特性,为磁稳定床氧化羰基化合成碳酸二苯酯提供数据。考察了不同操作条件对固相催化剂在磁稳定床中流化状态的影响,并通过流体力学软件FLUENT对实验进行计算模拟。结果表明:催化剂可以在流化床中达到完全流化状态,且起始流化速度随液体流速增大、外加磁场强度的增大及分布板开孔率减小而增大,床层高度随气相流速和液相流速减小而减小,随磁场强度的减小而增大,固相分布随床层高度减小而趋于密集,在实验气相流速范围内,床层的平均气相含率与气体流速基本呈直线上升关系。FLUENT软件模拟结果与实验过程完全吻合。%Using magnetic catalyst Pd/La0.5 Pb0.5 MnO3 as solid phase,N2 as gas phase,water as liquid phase,cold model experiment was carried out in the magnetically stabilized bed.The flow characteristics were explored for providing data to oxidation carbonyl synthesis of diphenyl carbonate.The influence of different operating conditions on the fluidized state of solid phase was studied,and the fluid dynamics software FLUENT was used for computer simulating experiment.The results show that in the fluidized bed the catalyst can be completely fluidized.The initial fluidization velocity is increased with increasing liquid flow rate,magnetic field strength and with decreasing opening ratio of the distribution plate.The bed height is decreased with decreasing gas velocity and liquid velocity and increased with the decreasing of the magnetic field strength.The distribution of the solid phase tends to be dense with decreasing height of the bed.In the experimental gas flow rate range,the average gas holdup in the bed is increased linearly with gas velocity.The FLUENT software simulation results are fitted well with the experimental

  13. Intermittent plate tectonics?

    Science.gov (United States)

    Silver, Paul G; Behn, Mark D

    2008-01-04

    Although it is commonly assumed that subduction has operated continuously on Earth without interruption, subduction zones are routinely terminated by ocean closure and supercontinent assembly. Under certain circumstances, this could lead to a dramatic loss of subduction, globally. Closure of a Pacific-type basin, for example, would eliminate most subduction, unless this loss were compensated for by comparable subduction initiation elsewhere. Given the evidence for Pacific-type closure in Earth's past, the absence of a direct mechanism for termination/initiation compensation, and recent data supporting a minimum in subduction flux in the Mesoproterozoic, we hypothesize that dramatic reductions or temporary cessations of subduction have occurred in Earth's history. Such deviations in the continuity of plate tectonics have important consequences for Earth's thermal and continental evolution.

  14. VISAS AND GREEN PLATES

    CERN Multimedia

    2000-01-01

    From 3 April 2000, all questions relating to visa requests for Switzerland, France, or Russia for a member of the personnel must be addressed to Ms. Agnita Querrou (telephone 72838, office 5-2-019, e-mail Agnita.Querrou@cern.ch).The Users' Office continues to deal with requests for letters of invitation and questions concerning visas for users in EP Division.Questions relating to removals, requests for green plates, to privileges of members of the personnel and to the importation of vehicles are still dealt with by Ms Zuzana Miller (telephone 79257, office 33-1-017, e-mail Zuzana.Muller@cern.ch) and Ms Joëlle Belleman (telephone 73962, office 33-1-019, e-mail Joelle.Belleman@cern.ch).

  15. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    2008-01-01

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  16. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  17. Rock stability considerations for siting and constructing a KBS-3 repository. Based on experiences from Aespoe HRL, AECL's URL, tunnelling and mining

    Energy Technology Data Exchange (ETDEWEB)

    Martin, C.D. [Univ. of Alberta, Edmonton (Canada); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Soederhaell, J. [VBB VIAK AB, Stockholm (Sweden)

    2001-12-01

    Over the past 25 years the international nuclear community has carried out extensive research into the deep geological disposal of nuclear waste in hard rocks. In two cases this research has resulted in the construction of dedicated underground research facilities: SKB's Aespoe Hard Rock Laboratory, Sweden and AECL's Underground Research Laboratory, Canada. Both laboratories are located in hard rocks considered representative of the Fennoscandian and Canadian Shields, respectively. This report is intended to synthesize the important rock mechanics findings from these research programs. In particular the application of these finding to assessing the stability of underground openings. As such the report draws heavily on the published results from the SKB's ZEDEX Experiment in Sweden and AECL's Mine- by Experiment in Canada. The objectives of this report are to: 1. Describe, using the current state of knowledge, the role rock engineering can play in siting and constructing a KBS-3 repository. 2. Define the key rock mechanics parameters that should be determined in order to facilitate repository siting and construction. 3. Discuss possible construction issues, linked to rock stability, that may arise during the excavation of the underground openings of a KBS-3 repository. 4. Form a reference document for the rock stability analysis that has to be carried out as a part of the design works parallel to the site investigations. While there is no unique or single rock mechanics property or condition that would render the performance of a nuclear waste repository unacceptable, certain conditions can be treated as negative factors. Outlined below are major rock mechanics issues that should be addressed during the siting, construction and closure of a nuclear waste repository in Sweden in hard crystalline rock. During the site investigations phase, rock mechanics information will be predominately gathered from examination and testing of the rock core and

  18. Three-dimensional imaging, change detection, and stability assessment during the centerline trench levee seepage experiment using terrestrial light detection and ranging technology, Twitchell Island, California, 2012

    Science.gov (United States)

    Bawden, Gerald W.; Howle, James; Bond, Sandra; Shriro, Michelle; Buck, Peter

    2014-01-01

    A full scale field seepage test was conducted on a north-south trending levee segment of a now bypassed old meander belt on Twitchell Island, California, to understand the effects of live and decaying root systems on levee seepage and slope stability. The field test in May 2012 was centered on a north-south trench with two segments: a shorter control segment and a longer seepage test segment. The complete length of the trench area measured 40.4 meters (m) near the levee centerline with mature trees located on the waterside and landside of the levee flanks. The levee was instrumented with piezometers and tensiometers to measure positive and negative porewater pressures across the levee after the trench was flooded with water and held at a constant hydraulic head during the seepage test—the results from this component of the experiment are not discussed in this report. We collected more than one billion three-dimensional light detection and ranging (lidar) data points before, during, and after the centerline seepage test to assess centimeter-scale stability of the two trees and the levee crown. During the seepage test, the waterside tree toppled (rotated 20.7 degrees) into the water. The landside tree rotated away from the levee by 5 centimeters (cm) at a height of 2 m on the tree. The paved surface of the levee crown had three regions that showed subsidence on the waterside of the trench—discussed as the northern, central, and southern features. The northern feature is an elongate region that subsided 2.1 cm over an area with an average width of 1.35 m that extends 15.8 m parallel to the trench from the northern end of the trench to just north of the trench midpoint, and is associated with a crack 1 cm in height that formed during the seepage test on the trench wall. The central subsidence feature is a semicircular region on the waterside of the trench that subsided by as much as 6.2 cm over an area 3.4 m wide and 11.2 m long. The southern feature is an elongate

  19. Plate tectonics, damage and inheritance.

    Science.gov (United States)

    Bercovici, David; Ricard, Yanick

    2014-04-24

    The initiation of plate tectonics on Earth is a critical event in our planet's history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately 3 billion years ago) suggests that plates and plate boundaries became widespread over a period of 1 billion years. The reason for this time lag is unknown but fundamental to understanding the origin of plate tectonics. Here we suggest that when sufficient lithospheric damage (which promotes shear localization and long-lived weak zones) combines with transient mantle flow and migrating proto-subduction, it leads to the accumulation of weak plate boundaries and eventually to fully formed tectonic plates driven by subduction alone. We simulate this process using a grain evolution and damage mechanism with a composite rheology (which is compatible with field and laboratory observations of polycrystalline rocks), coupled to an idealized model of pressure-driven lithospheric flow in which a low-pressure zone is equivalent to the suction of convective downwellings. In the simplest case, for Earth-like conditions, a few successive rotations of the driving pressure field yield relic damaged weak zones that are inherited by the lithospheric flow to form a nearly perfect plate, with passive spreading and strike-slip margins that persist and localize further, even though flow is driven only by subduction. But for hotter surface conditions, such as those on Venus, accumulation and inheritance of damage is negligible; hence only subduction zones survive and plate tectonics does not spread, which corresponds to observations. After plates have developed, continued changes in driving forces, combined with inherited damage and weak zones, promote increased tectonic complexity, such as oblique subduction, strike-slip boundaries that are subparallel to plate motion, and spalling of minor plates.

  20. High rate resistive plate chamber for LHC detector upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Y., E-mail: haddad@llr.in2p3.fr [Laboratoire Leprince-Ringuet (LLR), École Polytechnique, 91120 Palaiseau (France); Laktineh, I.; Grenier, G.; Lumb, N. [IPNL, Villeurbanne 69622 Lyon (France); Cauwenbergh, S. [Ghent University, Ghent (Belgium)

    2013-08-01

    The limitation of the detection rate of standard bakelite resistive plate chambers (RPCs) used as muon detectors in the LHC experiments has prevented the use of such detectors in the high rate regions in both CMS and ATLAS detectors. One alternative to these detectors is RPCs made with low resistivity glass plates (10{sup 10}Ωcm), a beam test at DESY has shown that such detectors can operate at few thousand Hz/cm{sup 2} with high efficiency (>90%)