ABB and the global market

International Nuclear Information System (INIS)

Lindahl, G.

1994-01-01

Competing in a global environment implies that the authors previous business environment has been less than global, and there are indeed changes underway that lead to a more universal environment. But, there are still differences between regions and especially between the mature economies in the OECD countries and the rapidly developing countries, of which a majority are in Asia. For the OECD countries, the time after World War 2 and up to about 1970 was a period of unprecedented growth. Rebuilding after the war and a general growth of the use of electric power required high investments in power systems and caused a booming market for equipment suppliers. After a trend break in the beginning of the 1970s to less than 40 GW 10 years later, then slowly increased to about 50 GW today. At the same time, annual capacity growth in developing countries increased from less than 20 GW to about 50 GW, i.e. the same level as in OECD. This means that ABB is now passing a cross-over point: from now on less than half of their global market is in their well-known OECD world. And this share will continue to shrink. ABB is now restructuring to fulfill market needs in less developed, developing, and newly industrialized countries. This is the most important change in their global environment is addressed in this article

Total quality approach at ABB Atom Nuclear Fuel - winner of the Swedish quality award 1994

International Nuclear Information System (INIS)

Moorlin, K.; Olsson, S.

1995-01-01

ABB Atom Nuclear Fuel Division received the Swedish Quality Award 1994. The company has since many years a reputation for high product quality and a well implemented quality assurance system. Since some years a total quality approach is applied. For ABB Atom, total quality means continuous improvement of all business processes keeping the customer in focus. This paper elaborates on the improvement tools used at the ABB Atom Nuclear Fuel Division and gives some detailed information of the experience. (author) 6 figs

Pulse-front tilt caused by the use of a grating monochromator and self-seeding of soft X-ray FELs

Energy Technology Data Exchange (ETDEWEB)

Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2012-03-15

Self-seeding is a promising approach to significantly narrow the SASE bandwidth of XFELs to produce nearly transform-limited pulses. The development of such schemes in the soft X-ray wavelength range necessarily involves gratings as dispersive elements. These introduce, in general, a pulse-front tilt, which is directly proportional to the angular dispersion. Pulse-front tilt may easily lead to a seed signal decrease by a factor two or more. Suggestions on how to minimize the pulse-front tilt effect in the self-seeding setup are given. (orig.)

Pulse-front tilt caused by the use of a grating monochromator and self-seeding of soft X-ray FELs

International Nuclear Information System (INIS)

Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

2012-03-01

Self-seeding is a promising approach to significantly narrow the SASE bandwidth of XFELs to produce nearly transform-limited pulses. The development of such schemes in the soft X-ray wavelength range necessarily involves gratings as dispersive elements. These introduce, in general, a pulse-front tilt, which is directly proportional to the angular dispersion. Pulse-front tilt may easily lead to a seed signal decrease by a factor two or more. Suggestions on how to minimize the pulse-front tilt effect in the self-seeding setup are given. (orig.)

ABB Turbo advanced fuel for application in System 80 family of plants

International Nuclear Information System (INIS)

Karoutas, Z.E.; Dixon, D.J.; Shapiro, N.L.

1998-01-01

ABB Combustion Engineering Nuclear Operations (ABB CE) has developed an Advanced Fuel Design, tailored to the Combustion Engineering, Inc. (CE) Nuclear Steam Supply System (NSSS) environment. This Advanced Fuel Design called Turbo features a full complement of innovative components, including GUARDIAN debris-resistant spacer grids, Turbo Zircaloy mixing grids to increase thermal margin and grid-to-rod fretting resistance, value-added fuel pellets to increase fuel loading, advanced cladding to increase achievable burnup, and axial blankets and Erbium integral burnable absorbers for improving fuel cycle economics. This paper summarizes the Turbo Fuel Design and its application to a System 80 family type plant. Benefits in fuel reliability, thermal margin, improved fuel cycle economics and burn up capability are compared relative to the current ABB CE standard fuel design. The fuel management design and the associated thermal margin are also evaluated. (author)

Rigorous modelling of light's intensity angular-profile in Abbe refractometers with absorbing homogeneous fluids

International Nuclear Information System (INIS)

García-Valenzuela, A; Contreras-Tello, H; Márquez-Islas, R; Sánchez-Pérez, C

2013-01-01

We derive an optical model for the light intensity distribution around the critical angle in a standard Abbe refractometer when used on absorbing homogenous fluids. The model is developed using rigorous electromagnetic optics. The obtained formula is very simple and can be used suitably in the analysis and design of optical sensors relying on Abbe type refractometry.

Calculating the Weather: Deductive Reasoning and Disciplinary "Telos" in Cleveland Abbe's Rhetorical Transformation of Meteorology

Science.gov (United States)

Majdik, Zoltan P.; Platt, Carrie Anne; Meister, Mark

2011-01-01

This paper explores the rhetorical basis of a major paradigm change in meteorology, from a focus on inductive observation to deductive, mathematical reasoning. Analysis of Cleveland Abbe's "The Physical Basis of Long-Range Weather Forecasts" demonstrates how in his advocacy for a new paradigm, Abbe navigates the tension between piety to tradition…

La figure historique d’Ibn ‘Abbâs

Directory of Open Access Journals (Sweden)

Viviane Comerro

2012-01-01

Full Text Available ‘Abdallâh b. ‘Abbâs est l’une des hautes figures du savoir islamique constitué au premier siècle. Les diverses notices biographiques qui lui ont été consacrées dans les sources sunnites en témoignent à travers le portrait lisse et monochrome du Compagnon et du savant. Cependant, un autre portrait nous a été conservé, celui d’un homme partisan, au cœur de la mêlée qui oppose les différents clans de Quraysh dans la lutte pour le pouvoir. La figure dessinée par l’ouvrage édité sous le titre Akhbâr al-Dawla l-‘Abbâsiyya (ou quelques autres ouvrages du même genre échappe en grande partie à l’exemplum déshistoricisé des traditionnistes. Cet autre point de vue ne donne nullement à croire que l’auteur anonyme des ADA nous fournit une image plus authentiquement historique d’Ibn ‘Abbâs, mais il vient contredire la vision des religieux, ou celle des anthropologues, qui s’attachent à gommer l’accidentel dans le portrait stéréotypé. Certes, l’homme de chair et d’os, l’individu Ibn ‘Abbâs, nous échappe définitivement, mais sa figure historique peut-être pas. On peut, en effet, se demander si dans les informations rapportées par certains akhbâr, et qui relèvent de la recréation littéraire, ne se dissimule pas aussi la démarche réflexive de l’historien qui met en scène des faits en leur fournissant une explication. À la différence des traditionnistes qui ne se risquent dans le conflit que de façon allusive ou feutrée, les historiographes et leurs informateurs, des hommes souvent non répertoriés parce qu’ils n’appartiennent pas aux cercles de la riwâya, ne dissimulent pas les enjeux d’ordre historique. Quelques exemples empruntés aux ADA en sont donnés.

ABB wet flue gas desulfurization

Energy Technology Data Exchange (ETDEWEB)

Niijhawan, P.

1994-12-31

The wet limestone process for flue gas desulfurization (FGD) is outlined. The following topics are discussed: wet flue gas desulfurization, wet FGD characteristics, wet scrubbers, ABB wet FGD experience, wet FGD forced oxidation, advanced limestone FGD systems, key design elements, open spray tower design, spray tower vs. packed tower, important performance parameters, SO{sub 2} removal efficiency, influence by L/G, limestone utilization, wet FGD commercial database, particulate removal efficiencies, materials of construction, nozzle layout, spray nozzles, recycle pumps, mist elimination, horizontal flow demister, mist eliminator washing, reagent preparation system, spray tower FGDS power consumption, flue gas reheat options, byproduct conditioning system, and wet limestone system.

Telerobotics: through-the-Internet teleoperation of the ABB IRB 2000 industrial robot

Science.gov (United States)

Alvares, Alberto J.; Caribe de Carvalho, Guilherme; Paulinyi, Luis F. d. A.; Alfaro, Sadek C. A.

1999-11-01

Robotic systems can be controlled remotely through the use of telerobotics. This work presents a through-the-internet teleoperation system for remotely operating the IRB2000 industrial robot. The IRB2000 controller allows external access through a RS232 serial communication link, which is based on a 42 function proprietary communication protocol. The proposed teleoperation system uses this communication capability by connecting it to a local area network based on TCP/IP (Transport Control Protocol/Internet Protocol). The system was implemented using a Client/Server architecture, having as server a UNIX (LINUX) platform.

Out-of-plane tilted Josephson junctions of bi-epitaxial YBa{sub 2}Cu{sub 3}O {sub x} thin films on tilted-axes NdGaO{sub 3} substrates with CeO{sub 2} seeding layer

Energy Technology Data Exchange (ETDEWEB)

Mozhaev, Peter B. [Institute of Physics and Technology RAS, Moscow 117218 (Russian Federation) and Department of Physics, Technical University of Denmark, Lyngby DK-2800 (Denmark)]. E-mail: pbmozh@nm.ru; Mozhaeva, Julia E. [Institute of Physics and Technology RAS, Moscow 117218 (Russian Federation); Department of Physics, Technical University of Denmark, Lyngby DK-2800 (Denmark); Bdikin, Igor K. [CICECO, University of Aveiro, Aveiro 3810-193 (Portugal); Kotelyanskii, Iosif M. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation); Luzanov, Valery A. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation); Zybtsev, Sergey G. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation); Hansen, Jorn Bindslev [Department of Physics, Technical University of Denmark, Lyngby DK-2800 (Denmark); Jacobsen, Claus S. [Department of Physics, Technical University of Denmark, Lyngby DK-2800 (Denmark)

2006-03-15

Bi-epitaxial heterostructures YBa{sub 2}Cu{sub 3}O {sub x}(YBCO)/CeO{sub 2}/NdGaO{sub 3} were prepared on tilted-axes NdGaO{sub 3} substrates using laser ablation technique. The heterostructures were patterned for electrical measurements using photolithography and ion-beam milling. Electrical anisotropy of the YBCO film was tested on the ion-beam etched surface. Bi-epitaxial junctions with four different orientations of the bi-epitaxial border were fabricated and studied. The measured I V curves showed flux-flow behavior with critical current density 2.5 x 10{sup 4} A/cm{sup 2} for the twist-type junctions and 1.5 x 10{sup 3} A/cm{sup 2} for [1 0 0]-tilt type junctions.

FRIGG '95. ABB Atom's upgraded T/H loop

International Nuclear Information System (INIS)

Noren, T.

1995-01-01

The FRIGG '95 project is an upgrading and modernization of the FRIGG loop, ABB Atom's fuel test rig with BWR operating conditions. The current FRIGG loop with test section and heater rods is described, together with the modifications involved in the FRIGG '95 project, including the new unique tomographic void measuring system to be installed. Finally CFD (Computational Fluid Dynamics) is introduced. (orig) (8 refs., 10 figs.)

Assessment of reflood heat transfer model of COBRA-TIF against ABB-CE evaluation model

Energy Technology Data Exchange (ETDEWEB)

Lee, S. I.; Lee, S. Y.; Park, C. E.; Choi, H. R.; Choi, C. J. [Korea Power Engineering Company Inc., Taejon (Korea, Republic of)

2000-05-01

According to 10 CFR 50 Appendix K, ECCS performance evaluation model should be based on the experimental data of FLECHT and have the conservatism compared with experimental data. To meet this requirement ABB-CE has the complicate code structure as follows: COMPERC-II calculates three reflood rates, and FLELAPC and HTCOF calculate the reflood heat transfer coefficients, and finally STRIKIN-II calculates the cladding temperature using the reflood heat transfer calculated in previous stage. In this paper, to investigate whether or not COBRA-TF satisfies the requirement of Appendix K, the reflood heat transfer coefficient of COBRA-TF was assessed against ABB-CE MOD-2C model. It was found out that COBRA-TF predicts properly the experimental data and has more conservatism than the results of ABB-CE MOD-2C model. Based on these results, it can be concluded that the reflood heat transfer coefficients calculated by COBRA-TF meet the requirement of Appendix K.

Addressing FinFET metrology challenges in 1X node using tilt-beam CD-SEM

Science.gov (United States)

Zhang, Xiaoxiao; Zhou, Hua; Ge, Zhenhua; Vaid, Alok; Konduparthi, Deepasree; Osorio, Carmen; Ventola, Stefano; Meir, Roi; Shoval, Ori; Kris, Roman; Adan, Ofer; Bar-Zvi, Maayan

2014-04-01

At 1X node, 3D FinFETS raise a number of new metrology challenges. Gate height and fin height are two of the most important parameters for process control. At present there is a metrology gap in inline in-die measurement of these parameters. In order to fill this metrology gap, in-column beam tilt has been developed and implemented on Applied Materials V4i+ top-down CD-SEM for height measurement. A low tilt (5°) beam and a high tilt (14°) beam have been calibrated to obtain two sets of images providing measurement of sidewall edge width to calculate height in the host. Evaluations are done with applications in both gate height and fin height. TEM correlation with R2 being 0.89 and precision of 0.81nm have been achieved on various in-die features in gate height application. Fin height measurement shows less accuracy (R2 being 0.77) and precision (1.49 nm) due to challenges brought by fin geometry, yet still promising as first attempt. Sensitivity to DOE offset, die-to-die and in-die variation is demonstrated in both gate height and fin height. Process defect is successfully captured from inline wafers with gate height measurement implemented in production. This is the first successful demonstration of inline in-die gate height measurement for 14nm FinFET process control.

Mathematical Formalism for Designing Wide-Field X-Ray Telescopes: Mirror Nodal Positions and Detector Tilts

Science.gov (United States)

Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.; Weisskopf, M. C.

2011-01-01

We provide a mathematical formalism for optimizing the mirror nodal positions along the optical axis and the tilt of a commonly employed detector configuration at the focus of a x-ray telescope consisting of nested mirror shells with known mirror surface prescriptions. We adopt the spatial resolution averaged over the field-of-view as the figure of merit M. A more complete description appears in our paper in these proceedings.

Maintaining Low Voiding Solder Die Attach for Power Die While Minimizing Die Tilt

Energy Technology Data Exchange (ETDEWEB)

Hamm, Randy; Peterson, Kenneth A.

2015-10-01

This paper addresses work to minimize voiding and die tilt in solder attachment of a large power die, measuring 9.0 mm X 6.5 mm X 0.1 mm (0.354” x 0.256” x 0.004”), to a heat spreader. As demands for larger high power die continue, minimizing voiding and die tilt is of interest for improved die functionality, yield, manufacturability, and reliability. High-power die generate considerable heat, which is important to dissipate effectively through control of voiding under high thermal load areas of the die while maintaining a consistent bondline (minimizing die tilt). Voiding was measured using acoustic imaging and die tilt was measured using two different optical measurement systems. 80Au-20Sn solder reflow was achieved using a batch vacuum solder system with optimized fixturing. Minimizing die tilt proved to be the more difficult of the two product requirements to meet. Process development variables included tooling, weight and solder preform thickness.

Method to fabricate a tilted logpile photonic crystal

Science.gov (United States)

Williams, John D.; Sweatt, William C.

2010-10-26

A method to fabricate a tilted logpile photonic crystal requires only two lithographic exposures and does not require mask repositioning between exposures. The mask and photoresist-coated substrate are spaced a fixed and constant distance apart using a spacer and the stack is clamped together. The stack is then tilted at a crystallographic symmetry angle (e.g., 45 degrees) relative to the X-ray beam and rotated about the surface normal until the mask is aligned with the X-ray beam. The stack is then rotated in plane by a small stitching angle and exposed to the X-ray beam to pattern the first half of the structure. The stack is then rotated by 180.degree. about the normal and a second exposure patterns the remaining half of the structure. The method can use commercially available DXRL scanner technology and LIGA processes to fabricate large-area, high-quality tilted logpile photonic crystals.

Doping and tilting on optics in noncentrosymmetric multi-Weyl semimetals

Science.gov (United States)

Mukherjee, S. P.; Carbotte, J. P.

2018-01-01

We calculate the absorptive part of the ac optical conductivity of a multi-Weyl semimetal with winding number J in both the direction of the tilt σz z(Ω ) and perpendicular to it σx x(Ω ) as a function of photon energy Ω , tilt C, and chemical potential μ (doping). For zero tilt there is a discontinuous rise in the conductivity at twice the value of the chemical potential Ω =2 μ . Below 2 μ , both σx x(Ω ) and σz z(Ω ) are zero and above 2 μ they merge with their value at charge neutrality and display a linear in Ω dependence for J =1 while for J =2 , σx x(Ω ) remains linear but σz z(Ω ) is instead constant. For finite tilt the sharp jump at Ω =2 μ is lost and the onset of absorption starts instead from zero at a lower photon energy Ω =2 μ /(1 +C ) after which it acquires a quasilinear rise to merge with the undoped untilted interband background at Ω =2 μ /(1 -C ) for type I Weyl while for type II the undoped untilted background is never recovered. For noncentrosymmetric materials the energies of a pair of opposite chirality Weyl nodes become shifted by ±Q0 and this leads to two separate absorption edges corresponding to the effective chemical potential of each of the two nodes at 2 (μ +χ Q0) depending on chirality χ =± . We provide analytic expressions for the conductivity in this case which depend only on the ratio Q0/μ and tilt when plotted against Ω /μ . The signature of finite energy shift Q0 is more pronounced for σz z and J =2 than for the other cases.

Out-of-substrate plane orientation control of thin YBa2Cu3O x films on NdGaO3 tilted-axes substrates

International Nuclear Information System (INIS)

Mozhaev, Peter B.; Mozhaeva, Julia E.; Bdikin, Igor K.; Kotelyanskii, Iosif M.; Lusanov, Valery A.; Hansen, Jorn Bindslev; Jacobsen, Claus S.; Kholkin, Andrey L.

2006-01-01

Epitaxial heterostructures YBa 2 Cu 3 O x (YBCO)/CeO 2 /NdGaO 3 were prepared on tilted-axes NdGaO 3 substrates using laser ablation technique. Morphology, crystal structure and electrical properties of the obtained films were characterized. The seeding mechanisms are affected by the tilt angle, resulting in superior YBCO films on NdGaO 3 substrates in an intermediate range of tilt angles of 6-14 o . The introduction of CeO 2 layer leads to change of the YBCO film orientation: at low deposition rate c-oriented films are formed, while at high deposition rates the film grows with c-axis tilted along the [1 1 0] NdGaO 3 direction. Bi-epitaxial films and structures were prepared by removal of part of the CeO 2 layer using ion-beam milling

Cs _1–x Rb _x PbCl ₃ and Cs _1–x Rb _x PbBr ₃ Solid Solutions: Understanding Octahedral Tilting in Lead Halide Perovskites

Energy Technology Data Exchange (ETDEWEB)

Linaburg, Matthew R.; McClure, Eric T.; Majher, Jackson D.; Woodward, Patrick M.

2017-04-03

The structures of the lead halide perovskites CsPbCl3 and CsPbBr3 have been determined from X-ray powder diffraction data to be orthorhombic with Pnma space group symmetry. Their structures are distorted from the cubic structure of their hybrid analogs, CH3NH3PbX3 (X = Cl, Br), by tilts of the octahedra (Glazer tilt system a–b+a–). Substitution of the smaller Rb+ for Cs+ increases the octahedral tilting distortion and eventually destabilizes the perovskite structure altogether. To understand this behavior, bond valence parameters appropriate for use in chloride and bromide perovskites have been determined for Cs+, Rb+, and Pb2+. As the tolerance factor decreases, the band gap increases, by 0.15 eV in Cs1–xRbxPbCl3 and 0.20 eV in Cs1–xRbxPbBr3, upon going from x = 0 to x = 0.6. The band gap shows a linear dependence on tolerance factor, particularly for the Cs1–xRbxPbBr3 system. Comparison with the cubic perovskites CH3NH3PbCl3 and CH3NH3PbBr3 shows that the band gaps of the methylammonium perovskites are anomalously large for APbX3 perovskites with a cubic structure. This comparison suggests that the local symmetry of CH3NH3PbCl3 and CH3NH3PbBr3 deviate significantly from the cubic symmetry of the average structure.

Germany's Intercity Express with ABB three-phase propulsion. The high-speed era begins for German Federal Railway

Energy Technology Data Exchange (ETDEWEB)

Schmidt, D.

1991-01-01

June 2, 1991, marked for German Federal Railway (DB) the start of a new era. On that day its new Intercity Express (ICE) trains began regular operation, setting new standards not only in travel comfort but also in technical and operational innovation. The train's present running speed on the Hamburg-Frankfurt-Munich line, which includes the longest section of DB's new high-speed 'Neubaustrecke' routes, is 250 km/h. Of the 60 ICE trains ordered by DB, 41 had been delivered by September 1991. ABB invested its entire AC drive know-how in the development of the train's power cars. Acting within a consortium, ABB Henschel supplied about one third of the electrical equipment, including transformers, power converters and the control equipment, which includes DAVID, a modern diagnostics system. Other ABB deliveries were the displays for the drivers' cabs and the locomotive's safety equipment. Among the mechanical parts ABB supplied were the bogies, doors, walls and roofs, and the brake modules. (orig.).

Estimation of pelvic tilt on anteroposterior X-rays - a comparison of six parameters

International Nuclear Information System (INIS)

Tannast, M.; Murphy, S.B.; Langlotz, F.; Anderson, S.E.; Siebenrock, K.A.

2006-01-01

To compare six different parameters described in literature for estimation of pelvic tilt on an anteroposterior pelvic radiograph and to create a simple nomogram for tilt correction of prosthetic cup version in total hip arthroplasty. Simultaneous anteroposterior and lateral pelvic radiographs are taken routinely in our institution and were analyzed prospectively. The different parameters (including three distances and three ratios) were measured and compared to the actual pelvic tilt on the lateral radiograph using simple linear regression analysis. One hundred and four consecutive patients (41 men, 63 women with a mean age of 31.7 years, SD 9.2 years, range 15.7-59.1 years) were studied. The strongest correlation between pelvic tilt and one of the six parameters for both men and women was the distance between the upper border of the symphysis and the sacrococcygeal joint. The correlation coefficient was 0.68 for men (P<0.001) and 0.61 for women (P<0.001). Based on this linear correlation, a nomogram was created that enables fast, tilt-corrected cup version measurements in clinical routine use. This simple method for correcting variations in pelvic tilt on plain radiographs can potentially improve the radiologist's ability to diagnose and interpret malformations of the acetabulum (particularly acetabular retroversion and excessive acetabular overcoverage) and post-operative orientation of the prosthetic acetabulum. (orig.)

Control of Pan-tilt Mechanism Angle using Position Matrix Method

Directory of Open Access Journals (Sweden)

Hendri Maja Saputra

2013-12-01

Full Text Available Control of a Pan-Tilt Mechanism (PTM angle for the bomb disposal robot Morolipi-V2 using inertial sensor measurement unit, x-IMU, has been done. The PTM has to be able to be actively controlled both manually and automatically in order to correct the orientation of the moving Morolipi-V2 platform. The x-IMU detects the platform orientation and sends the result in order to automatically control the PTM. The orientation is calculated using the quaternion combined with Madwick and Mahony filter methods. The orientation data that consists of angles of roll (α, pitch (β, and yaw (γ from the x-IMU are then being sent to the camera for controlling the PTM motion (pan & tilt angles after calculating the reverse angle using position matrix method. Experiment results using Madwick and Mahony methods show that the x-IMU can be used to find the robot platform orientation. Acceleration data from accelerometer and flux from magnetometer produce noise with standard deviation of 0.015 g and 0.006 G, respectively. Maximum absolute errors caused by Madgwick and Mahony method with respect to Xaxis are 48.45º and 33.91º, respectively. The x-IMU implementation as inertia sensor to control the Pan-Tilt Mechanism shows a good result, which the probability of pan angle tends to be the same with yaw and tilt angle equal to the pitch angle, except a very small angle shift due to the influence of roll angle..

BWR 90 and BWR 90+: Two advanced BWR design generations from ABB

International Nuclear Information System (INIS)

Haukeland, S.; Ivung, B.; Pedersen, T.

1999-01-01

ABB has two evolutionary advanced light water reactors available today - the BWR 90 boiling water reactor and the System 80+ pressurised water reactor. The BWR 90 is based on the design, construction, commissioning and operation of the BWR 75 plants. The operation experience of the six plants of this advanced design has been very good. The average annual energy availability is above 90%, and total power generation costs have been low. When developing the BWR 90 specific changes were introduced to a reference design, to adapt to technological progress, new safety requirements and to achieve cost savings. The thermal power rating of BWR 90 is 3800 MWth (providing a nominal 1374 MWe net), slightly higher than that of the reference plant ABB Atom has taken advantage of margins gained using a new generation of its SVEA fuel to attain this power rating without major design modifications. The BWR 90 design was completed and offered to the TVO utility in Finland in 1991, as one of the contenders for the fifth Finnish nuclear power plant project. Hence, the design is available today for deployment in new plant projects. Utility views were incorporated through co-operation with the Finnish utility TVO, owner and operator of the two Olkiluoto plants of BWR 75 design. A review against the European Utility Requirement (EUR) set of requirements has been performed, since the design, in 1997, was selected by the EUR Steering Committee to be the first BWR to be evaluated against the EUR documents. The review work was completed in 1998. It will be the subject of an 'EUR Volume 3 Subset for BWR 90' document. ABB is continuing its BWR development work with an 'evolutionary' design called BWR 90+, which aims at developing the BWR as a competitive option for the anticipated revival of the market for new nuclear plants beyond the turn of the century, as well as feeding ideas and inputs to the continuous modernisation efforts at operating plants. The development is performed by ABB Atom

ABB Oy Motors and Generators -yksikön energiansyöttöjen erotus- ja lukitusohjeet

OpenAIRE

Chi, Henri

2017-01-01

Tämä insinöörityö toteutettiin Quant Finland Oy:lle, joka vastaa Helsingin Pitäjänmäen ABB Motors and Generators -tehtaan kunnossapidosta. Insinöörityön tavoitteena oli luoda energiansyöttöjen lukitus- ja erotusohjeet tehtaan koneistoille, laitteille ja järjestelmille. Tehtaalla on isoja koneita ja laitteita, jonka erotus- ja lukitustoimenpiteitä kaikki eivät osaa. Näin ollen on haluttu mahdollistaa turvallinen työskentely tarjoamalla selkeät erotus- ja lukitusohjeet. ABB Motors and Gene...

Jahn-Teller distortions, cation ordering and octahedral tilting in perovskites

International Nuclear Information System (INIS)

Lufaso, M.W.; Woodward, P.M.

2004-01-01

In transition metal oxides, preferential occupation of specific d orbitals on the transition metal ion can lead to the development of a long-range ordered pattern of occupied orbitals. This phenomenon, referred to as orbital ordering, is usually observed indirectly from the cooperative Jahn-Teller distortions (CJTDs) that result as a consequence of the orbital ordering. This paper examines the interplay between orbital ordering, octahedral tilting and cation ordering in perovskites. Both ternary AMX 3 perovskites containing an active Jahn-Teller (J-T) ion on the octahedral site and quaternary A 2 MM'X 6 perovskites containing a J-T ion on one-half of the octahedral sites have been examined. In AMX 3 perovskites, the tendency is for the occupied 3d 3x 2 -r 2 and 3d 3z 2 -r 2 orbitals to order in the ac plane, as exemplified by the crystal structures of LaMnO 3 and KCuF 3 . This arrangement maintains a favorable coordination environment for the anion sites. In AMX 3 perovskites, octahedral tilting tends to enhance the magnitude of the J-T distortions. In A 2 MM'X 6 perovskites, the tendency is for the occupied 3d 3z 2 -r 2 orbitals to align parallel to the c axis. This pattern maintains a favorable coordination environment about the symmetric M'-cation site. The orbital ordering found in rock-salt ordered A 2 MM'X 6 perovskites is compatible with octahedral rotations about the c axis (Glazer tilt system a 0 a 0 c - ) but appears to be incompatible with GdFeO 3 -type octahedral tilting (tilt system - b + a - ). (orig.)

NEuclid: a long-range tilt-immune homodyne interferometer

Science.gov (United States)

Bradshaw, M. J.; Speake, C. C.

2017-11-01

The new Easy to Use Compact Laser Interferometric Device (nEUCLID) is a polarisation-based homodyne interferometer with substantially unequal arms that is tolerant to target mirror tilt. The design has no active components, uses standard optical components of 25 mm diameter, has a working distance of 706 mm and a reference arm-length of 21 mm. nEUCLID optics have a footprint of 210 x 190 x 180 mm, and has a tolerance to target mirror tilt of +/- 0.5 degrees, made possible by a novel new retro-reflector design [1]. nEUCLID was built to a set of specifications laid down by Airbus Defence and Space, who required a lowmass, low-power device to measure displacement with nanometre accuracy for space applications. At the University of Birmingham we have previously built a smaller, more compact tilt-insensitive homodyne interferometer - the EUCLID [2, 3, 4] - which has a working distance of 6 mm, a working range of +/- 3 mm, and a tilt range of +/- 1° [2]. We created a new optical design to allow a much larger working distance to be achieved (as discussed in Section II) and used this in a new interferometer - the nEUCLID. Section II describes the interferometer in detail; how nEUCLID is tilt insensitive, and the optical configuration. Section III states the design specifications from Airbus Defence and Space and the components used in the final design. The output interference pattern from nEUCLID, and how it has been corrected with a meniscus lens, is also discussed. In Section IV we discuss the results demonstrating the tilt immunity range, and the sensitivity of the device. Section V describes several potential applications of nEUCLID, and Section VI draws together our conclusions.

Conceptual design study of 1985 commercial tilt rotor transports. Volume 3. STOL design summary. Final report

Energy Technology Data Exchange (ETDEWEB)

Sambell, K.W.

1976-04-01

A conceptual design study is presented of 1,985 commercial tilt rotor STOL transports for a NASA 200 n. mi. (370 km) STOL Mission. A 100-passenger STOL Variant (Bell D313) of the Phase I VTOL Tilt Rotor Aircraft is defined. Aircraft characteristics are given; with the aircraft redesigned to meet 2,000-foot (610 m) field criteria, with emphasis on low fuel consumption and low direct operating cost. The 100-passenger STOL Tilt Rotor Aircraft was analyzed for performance, weights, economics, handling qualities, noise footprint and aeroelastic stability. (GRA)

Dynamic of charged planar geometry in tilted and non-tilted frames

Energy Technology Data Exchange (ETDEWEB)

Sharif, M., E-mail: msharif.math@pu.edu.pk; Zaeem Ul Haq Bhatti, M., E-mail: mzaeem.math@pu.edu.pk [University of the Punjab, Department of Mathematics (Pakistan)

2015-05-15

We investigate the dynamics of charged planar symmetry with an anisotropic matter field subject to a radially moving observer called a tilted observer. The Einstein-Maxwell field equations are used to obtain a relation between non-tilted and tilted frames and between kinematical and dynamical quantities. Using the Taub mass formalism and conservation laws, two evolution equations are developed to analyze the inhomogeneities in the tilted congruence. It is found that the radial velocity (due to the tilted observer) and the electric charge have a crucial effect on the inhomogeneity factor. Finally, we discuss the stability in the non-tilted frame in the pure diffusion case and examine the effects of the electromagnetic field.

Novel tilt-curvature coupling in lipid membranes

Science.gov (United States)

Terzi, M. Mert; Deserno, Markus

2017-08-01

On mesoscopic scales, lipid membranes are well described by continuum theories whose main ingredients are the curvature of a membrane's reference surface and the tilt of its lipid constituents. In particular, Hamm and Kozlov [Eur. Phys. J. E 3, 323 (2000)] have shown how to systematically derive such a tilt-curvature Hamiltonian based on the elementary assumption of a thin fluid elastic sheet experiencing internal lateral pre-stress. Performing a dimensional reduction, they not only derive the basic form of the effective surface Hamiltonian but also express its emergent elastic couplings as trans-membrane moments of lower-level material parameters. In the present paper, we argue, though, that their derivation unfortunately missed a coupling term between curvature and tilt. This term arises because, as one moves along the membrane, the curvature-induced change of transverse distances contributes to the area strain—an effect that was believed to be small but nevertheless ends up contributing at the same (quadratic) order as all other terms in their Hamiltonian. We illustrate the consequences of this amendment by deriving the monolayer and bilayer Euler-Lagrange equations for the tilt, as well as the power spectra of shape, tilt, and director fluctuations. A particularly curious aspect of our new term is that its associated coupling constant is the second moment of the lipid monolayer's lateral stress profile—which within this framework is equal to the monolayer Gaussian curvature modulus, κ¯ m. On the one hand, this implies that many theoretical predictions now contain a parameter that is poorly known (because the Gauss-Bonnet theorem limits access to the integrated Gaussian curvature); on the other hand, the appearance of κ¯ m outside of its Gaussian curvature provenance opens opportunities for measuring it by more conventional means, for instance by monitoring a membrane's undulation spectrum at short scales.

CT patellar cortex tilt angle: A radiological method to measure patellar tilt

International Nuclear Information System (INIS)

Mirza Toluei, F.; Afshar, A.; Salarilak, S.; Sina, A.

2005-01-01

Background/Objectives: the role of patellar tilt in the anterior knee pain is indisputable. Traditionally. the lateral patello-femoral angle of Laurin has been defined in both the axial view and CT images for measuring the tilt of patella. We present a new angle. which is independent of the morphology of patella and directly relates to clinical assessment of the tilt. which is appreciated from palpation of the edges of the patella. Patients and Methods: 38 patients with anterior knee pain and forty normal control subjects were examined using CT scan of patello-femoral joint in 15 degrees of knee flexion. The amount of lateral patellar tilt was quantitatively assessed using the lateral patello-femoral angle, as described by Laurin et al, and the newly defined patellar cortex tilt angle. This angle is subtended by the line drawn along the posterior femoral condyles and the one parallel to the subchondral bone of patellar cortex. The fifteen-degree tilt was taken as normal cut-off point for patellar cortex tilt angle in the control group. Results: in patients, the average tilt of patella. using the patellar cortex tilt angle was 15.26 versus 7.05 in the control group. Using Student's t test, the difference between the two means was significant (P<0.001). The sensitivity and specificity of patellar cortex tilt angle were 40 and 90 percent, respectively There was a moderate agreement between our presented test and the lateral tilt angle test (kappa=0.40. P<0.001). Conclusion: our results indicate that patellar tilt can also be detected using patellar cortex tilt angle. We need more specific studies ta determine the validity of the test

Assessment of the TASS 1-D neutronics model for the westinghouse and ABB-CE type PWR reactivity induced transients

International Nuclear Information System (INIS)

Choi, J.D.; Yoon, H.Y.; Um, K.S.; Kim, H.C.; Sim, S.K.

1997-01-01

Best estimate transient analysis code, TASS, has been developed for the normal and transient simulation of the Westinghouse and ABB-CE type PWRs. TASS thermal hydraulic model is based on the non-homogeneous, non-equilibrium two-phase continuity, energy and mixture momentum equations with constitutive relations for closure. Core neutronics model employs both the point kinetics and one-dimensional neutron diffusion model. Semi-implicit numerical scheme is used to solve the discretized finite difference equations. TASS one dimensional neutronics core model has been assessed through the reactivity induced transient analyses for the KORI-3, three loop Westinghouse PWR, and Younggwang-3 (YGN-3), two-loop ABB-CE PWR, nuclear power plants currently operating in Korea. The assessment showed that the TASS one dimensional neutronics core model can be applied for the Westinghouse and ABB-CE type PWRs to gain thermal margin which is necessary for a potential use of the high fuel burnup, extended fuel cycle, power upgrading and for the plant life extension

Tilt testing results are influenced by tilt protocol.

Science.gov (United States)

Zyśko, Dorota; Fedorowski, Artur; Nilsson, David; Rudnicki, Jerzy; Gajek, Jacek; Melander, Olle; Sutton, Richard

2016-07-01

It is unknown how the return to supine position influences duration of loss of consciousness (LOC) and cardioinhibition during tilt test. Retrospective analysis of two datasets containing records of patients who underwent tilt testing for unexplained syncope in two centres was performed. Patients, totalling 1232, were included in the study: 262 in a Swedish centre and 970 patients in a Polish centre. In Sweden, tilt table with tilt-down time (TDT) of 18 s was used (Group II). In Poland, two different tilt tables were used, one of them with TDT of 10 s (Group I, n = 325), and the other with TDT of 47 s (Group III, n = 645). Cardioinhibitory reflex occurred most frequently in Group III, whereas number of pauses >3 s, frequency of very long asystole ≥30 s, and the total duration of pauses >3 s demonstrated a trend to increase from Group I to III. Duration of LOC in Groups II and III was significantly longer compared with Group I (32.0 and 33.7 s vs. 16.4 s). In the multivariate-adjusted regression model, cardioinhibitory reflex was predicted by tilt-table model (odds ratio per model with increasing TDT: 1.40; 95% confidence interval, 1.19-1.64; P < 0.0001), whereas LOC duration was longer with increasing TDT (P < 0.0001) and age (P < 0.0001). Longer TDT during induced vasovagal syncope increases the prevalence of cardioinhibitory reflex and prolongs the duration of LOC. Tilt-down time does not affect asystolic pause duration but delay may lead to occurrence of multiple pauses, higher frequency of very long asystole, and longer total asystole duration. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Out-of-substrate plane orientation control of thin YBa{sub 2}Cu{sub 3}O {sub x} films on NdGaO{sub 3} tilted-axes substrates

Energy Technology Data Exchange (ETDEWEB)

Mozhaev, Peter B. [Institute of Physics and Technology RAS, Moscow 117218 (Russian Federation) and Department of Physics, Technical University of Denmark, Lyngby, DK-2800 (Denmark)]. E-mail: pbmozh@nm.ru; Mozhaeva, Julia E. [Institute of Physics and Technology RAS, Moscow 117218 (Russian Federation); Department of Physics, Technical University of Denmark, Lyngby, DK-2800 (Denmark); Bdikin, Igor K. [Institute of Solid State Physics RAS, Chernogolovka, Moscow distr., 142432 (Russian Federation); CICECO, University of Aveiro, Aveiro 3810-193 (Portugal); Kotelyanskii, Iosif M. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation); Lusanov, Valery A. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation); Hansen, Jorn Bindslev [Department of Physics, Technical University of Denmark, Lyngby, DK-2800 (Denmark); Jacobsen, Claus S. [Department of Physics, Technical University of Denmark, Lyngby, DK-2800 (Denmark); Kholkin, Andrey L. [CICECO, University of Aveiro, Aveiro 3810-193 (Portugal)

2006-02-01

Epitaxial heterostructures YBa{sub 2}Cu{sub 3}O {sub x}(YBCO)/CeO{sub 2}/NdGaO{sub 3} were prepared on tilted-axes NdGaO{sub 3} substrates using laser ablation technique. Morphology, crystal structure and electrical properties of the obtained films were characterized. The seeding mechanisms are affected by the tilt angle, resulting in superior YBCO films on NdGaO{sub 3} substrates in an intermediate range of tilt angles of 6-14{sup o}. The introduction of CeO{sub 2} layer leads to change of the YBCO film orientation: at low deposition rate c-oriented films are formed, while at high deposition rates the film grows with c-axis tilted along the [1 1 0] NdGaO{sub 3} direction. Bi-epitaxial films and structures were prepared by removal of part of the CeO{sub 2} layer using ion-beam milling.

Colgajo Sabattini-Abbe en H tumbada para reconstrucción de labio leporino bilateral secundario

Directory of Open Access Journals (Sweden)

Juan Márquez-Cañada

Full Text Available La reconstrucción del labio leporino secundario tiene al colgajo Sabattini-Abbe como una de sus principales herramientas reconstructivas básicas, si bien se han propuesto diferentes modificaciones de la técnica original para lograr una minuciosa reconstrucción de las deformidades secundarias presentes en los pacientes con labio leporino. Presentamos una modificación del colgajo Sabattini-Abbe, el colgajo en H tumbada. Este colgajo modificado incluye un segmento vertical y dos horizontales para restaurar con un solo colgajo, y adhiriéndonos al principio de la Cirugía Plástica de reconstruir lo similar con lo similar, tanto piel como bermellón de las áreas central y laterales del labio superior, las cuales se hallan comúnmente afectadas en los pacientes con labio leporino bilateral secundario.

Tilted magnetic field quantum magnetotransport in the double quantum well with a sizable bulk g-factor: InxGa1-xAs/GaAs

NARCIS (Netherlands)

Yakunin, M.V.; Galistu, G.; de Visser, A.

2008-01-01

Rich patterns of transformations in the structure of quantum Hall (QH) effect and magnetoresistivity under tilted magnetic fields were obtained in the InxGa1-xAs/GaAs double quantum well at mK temperatures. Local features correspond to the calculated intersections of Landau levels from different

L’ARCHE DE NOÉ et autres articles religieux de l’abbé Mallet dans l’Encyclopédie

OpenAIRE

Rex, Walter E.

2006-01-01

Complètement oublié aujourd’hui, l’abbé Edme Mallet (1713-55) fournit à l’Encyclopédie plus de mille articles portant surtout sur l’histoire ancienne et moderne et sur la littérature. Il écrivit aussi et ce fut son principal titre de gloire dans l’entreprise — des articles de théologie : en effet, il y figure comme théologien en titre de tous les premiers volumes. S’il faut reconnaître la considérable érudition de l’abbé Mallet comme historien, on peut néanmoins légitimement se demander pour ...

NUMERICAL SIMULATIONS OF NATURALLY TILTED, RETROGRADELY PRECESSING, NODAL SUPERHUMPING ACCRETION DISKS

International Nuclear Information System (INIS)

Montgomery, M. M.

2012-01-01

Accretion disks around black hole, neutron star, and white dwarf systems are thought to sometimes tilt, retrogradely precess, and produce hump-shaped modulations in light curves that have a period shorter than the orbital period. Although artificially rotating numerically simulated accretion disks out of the orbital plane and around the line of nodes generate these short-period superhumps and retrograde precession of the disk, no numerical code to date has been shown to produce a disk tilt naturally. In this work, we report the first naturally tilted disk in non-magnetic cataclysmic variables using three-dimensional smoothed particle hydrodynamics. Our simulations show that after many hundreds of orbital periods, the disk has tilted on its own and this disk tilt is without the aid of radiation sources or magnetic fields. As the system orbits, the accretion stream strikes the bright spot (which is on the rim of the tilted disk) and flows over and under the disk on different flow paths. These different flow paths suggest the lift force as a source to disk tilt. Our results confirm the disk shape, disk structure, and negative superhump period and support the source to disk tilt, source to retrograde precession, and location associated with X-ray and He II emission from the disk as suggested in previous works. Our results identify the fundamental negative superhump frequency as the indicator of disk tilt around the line of nodes.

Effect of Ca doping level on the laser-induced voltages in tilted La{sub 1-x}Ca{sub x}MnO{sub 3} (0.1 ≤ x ≤ 0.7) thin films

Energy Technology Data Exchange (ETDEWEB)

Ma, Ji; Zhang, Hui; Chen, Qingming; Liu, Xiang [Kunming University of Science and Technology, Faculty of Materials Science and Engineering, Kunming (China); Theingi, Mya [Kunming University of Science and Technology, Faculty of Materials Science and Engineering, Kunming (China); University of Yangon, Department of Chemistry, Yangon (Myanmar)

2014-03-15

Tilted La{sub 1-x}Ca{sub x}MnO{sub 3} (0.1 ≤ x ≤ 0.7) thin films have been grown on vicinal cut LaAlO{sub 3} (100) substrate by pulsed laser deposition. The laser-induced voltage effect was studied at room temperature with the KrF excimer laser using as the thermal source. The relationships between Ca doping level and voltage signal, response time and anisotropy Seebeck coefficient were established. The voltage signal and anisotropy Seebeck coefficient increase at first with increasing Ca doping level, reach a maximum at the same Ca content around x = 0.5, and then decrease. The respond time decreases with the Ca concentration increasing, and changes very little after x = 0.5. The figure of merit F{sub m} was also the largest at this doping level, indicating a potential good performance of the photodetector devices. The variation of intrinsic structural and transport anisotropy induced by the change of Ca concentration has been proposed to account for the different LIV effects observed in LCMO thin films. (orig.)

19 years of tilt data on Mt. Vesuvius: state of the art and future perspectives

Directory of Open Access Journals (Sweden)

Ciro Ricco

2013-11-01

Full Text Available Mt. Vesuvius, located along the SW border of the Campania Plane graben, is one of the most studied volcanoes worldwide, from both the volcanological and the geophysical, geochemical and geodetic point of view. In order to better understand its dynamics, the deformation of the volcano has been already studied since the early ’70s by setting up levelling lines and, since a few years later, through trilateration networks, whereas ground tilt monitoring started in 1993. Tilt variations were recorded by an automatic surface station set up at the Osservatorio Vesuviano (O.V. bunker (OVO and data recorded were transmitted to the O.V. Surveillance Centre in Naples. Afterwards, in 1996 two more identical stations were set up close to Torre del Greco (CMD, and close to Trecase (TRC. In 2002 the data acquisition system was replaced, while at the end of 2011 a Lily borehole sensor was set up at 26 m depth, replacing the old TRC tilt station. The paper describes in details the tilt network of Mt. Vesuvius, its development over time and the data processing procedure; moreover, the ground deformation pattern is discussed, as inferred from the study of 19 years of data and its change during the seismic crises of 1995-1996 and 1999-2000. From the information obtained from the tiltmetric monitoring, a complex deformation pattern can be deduced, strongly dependent on the position of the sites in which the sensors were set up with respect to the morphology of the volcanic edifice and its structural outlines. If we consider the signals as they were recorded, although previously corrected for the influences of the thermo-elastic strain on the sensors, the tilting occurs mainly in the SW direction with rates of about 11 µradians/year on both the western and eastern flanks and of about 13 µradians/year on the southern one. Because tilt vectors point in the long term outward from the summit and towards the subsiding area, this supports the hypothesis of a southern

Use of ABB ADVANT Power for large scale instrumentation and controls replacements in nuclear power plants

International Nuclear Information System (INIS)

Pucak, J.L.; Brown, E.M.

1999-01-01

One of the major issues facing plants planning for life extension is the viability and feasibility of modernization of a plant's existing I and C systems including the safety systems and the control room. This paper discusses the ABB approach to the implementation of large scale Instrumentation and Controls (I and C) modernization. ABB applies a segmented architecture approach using the ADVANT Power control system to meet the numerous constraints of a major I and C upgrade program. The segmented architecture and how it supports implementation of a complete I and C upgrade either in one outage or in a series of outages is presented. ADVANT Power contains standardized industrial control equipment that is designed to support 1E applications as well as turbine and non-1E process control. This equipment forms the basis for the architecture proposed for future new nuclear plant sales as well as large scale retrofits. (author)

Tilt angles and positive response of head-up tilt test in children with orthostatic intolerance.

Science.gov (United States)

Lin, Jing; Wang, Yuli; Ochs, Todd; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

2015-01-01

This study aimed at examining three tilt angle-based positive responses and the time to positive response in a head-up tilt test for children with orthostatic intolerance, and the psychological fear experienced at the three angles during head-up tilt test. A total of 174 children, including 76 boys and 98 girls, aged from 4 to 18 years old (mean 11.3±2.8 years old), with unexplained syncope, were randomly divided into three groups, to undergo head-up tilt test at the angles of 60°, 70° and 80°, respectively. The diagnostic rates and times were analysed, and Wong-Baker face pain rating scale was used to access the children's psychological fear. There were no significant differences in diagnostic rates of postural orthostatic tachycardia syndrome and vasovagal syncope at different tilt angles during the head-up tilt test (p>0.05). There was a significant difference, however, in the psychological fear at different tilt angles utilising the Kruskal-Wallis test (χ2=36.398, ptest (ptest for vasovagal syncope or for postural orthostatic tachycardia syndrome. Hence, it is suggested that a tilt angle of 60° and head-up tilt test time of 45 minutes should be suitable for children with vasovagal syncope.

Modulated electron bunch with amplitude front tilt in an undulator

International Nuclear Information System (INIS)

Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

2015-12-01

In a previous paper we discussed the physics of a microbunched electron beam kicked by the dipole field of a corrector magnet by describing the kinematics of coherent undulator radiation after the kick. We demonstrated that the effect of aberration of light supplies the basis for understanding phenomena like the deflection of coherent undulator radiation by a dipole magnet. We illustrated this fact by examining the operation of an XFEL under the steady state assumption, that is a harmonic time dependence. We argued that in this particular case the microbunch front tilt has no objective meaning; in other words, there is no experiment that can discriminate whether an electron beam is endowed with a microbunch front tilt of not. In this paper we extend our considerations to time-dependent phenomena related with a finite electron bunch duration, or SASE mode of operation. We focus our attention on the spatiotemporal distortions of an X-ray pulse. Spatiotemporal coupling arises naturally in coherent undulator radiation behind the kick, because the deflection process involves the introduction of a tilt of the bunch profile. This tilt of the bunch profile leads to radiation pulse front tilt, which is equivalent to angular dispersion of the output radiation. We remark that our exact results can potentially be useful to developers of new generation XFEL codes for cross-checking their results.

Bi-epitaxial YBa{sub 2}Cu{sub 3}O{sub x} Thin Films on Tilted-axes NdGaO{sub 3} Substrates with CeO{sub 2} Seeding Layer

Energy Technology Data Exchange (ETDEWEB)

Mozhaev, P B [Institute of Physics and Technology RAS, 117218, Moscow (Russian Federation); Mozhaeva, J E [Institute of Physics and Technology RAS, 117218, Moscow (Russian Federation); Jacobsen, C S [Technical University of Denmark, Physics Department, Lyngby, DK-2800, Denmark (Denmark); Hansen, J Bindslev [Technical University of Denmark, Physics Department, Lyngby, DK-2800, Denmark (Denmark); Bdikin, I K [CICECO, University of Aveiro, Aveiro, 3810-193 (Portugal); Luzanov, V A [Institute of Radio Engineering and Electronics, Moscow, 125009 (Russian Federation); Kotelyanskii, I M [Institute of Radio Engineering and Electronics, Moscow, 125009 (Russian Federation); Zybtsev, S G [Institute of Radio Engineering and Electronics, Moscow, 125009 (Russian Federation)

2006-06-01

Bi-epitaxial YBa{sub 2}Cu{sub 3}O{sub x} (YBCO) thin films with out-of-plane tilt angle in the range 18 - 27{sup 0} were manufactured using pulsed laser deposition on NdGaO{sub 3} tilted-axes substrates with CeO{sub 2} seeding layers. The YBCO thin film orientation over the seeding layer depended on deposition conditions. Removal of the seeding layer from part of the substrate surface by ionbeam etching resulted in formation of a bi-epitaxial thin film with different c-axis orientation of two parts of the film. The bi-epitaxial film orientation and structure were studied using X-ray diffraction techniques, and surface morphology was observed with atomic force microscope (AFM). Photolithography and ion-beam etching techniques were used for patterning bi-epitaxial thin films. Electrical characterization of the obtained structures was performed.

Effective wave tilt and surface impedance over a laterally inhomogeneous two-layer earth

International Nuclear Information System (INIS)

Hughes, W.J.; Wait, J.R.

1975-01-01

Using a perturbation method, the effect of a simple two-dimensional model on the electromagnetic fields at the surface of the Earth is considered for a postulated downcoming plane wave. The calculated change in the surface impedance and wave tilt due to lateral inhomogeneities is examined. It is found that the magnetic wave tilt (H/sub z//H/sub x/) is most seriously affected by such anomalies. This may have important consequences on electromagnetic probing of nonuniform portions of the Earth's crust

Advanced single-slice rebinning for tilted spiral cone-beam CT

International Nuclear Information System (INIS)

Kachelriess, Marc; Fuchs, Theo; Schaller, Stefan; Kalender, Willi A.

2001-01-01

Future medical CT scanners and today's micro CT scanners demand cone-beam reconstruction algorithms that are capable of reconstructing data acquired from a tilted spiral trajectory where the vector of rotation is not necessarily parallel to the vector of table increment. For the medical CT scanner this case of nonparallel object motion is met for nonzero gantry tilt: the table moves into a direction that is not perpendicular to the plane of rotation. Since this is not a special application of medical CT but rather a daily routine in head exams, there is a strong need for corresponding reconstruction algorithms. In contrast to medical CT, where the special case of nonperpendicular motion is used on purpose, micro CT scanners cannot avoid aberrations of the rotational axis and the table increment vector due to alignment problems. Especially for those micro CT scanners that have the lifting stage mounted on the rotation table (in contrast to setups where the lifting stage holds the rotation table), this kind of misalignment is equivalent to a gantry tilt. We therefore generalize the advanced single-slice rebinning algorithm (ASSR), which is considered a very promising approach for medical cone-beam reconstruction due to its high image quality and its high reconstruction speed [Med. Phys. 27, 754-772 (2000)], to the case of tilted gantries. We evaluate this extended ASSR approach (which we will denote as ASSR + , for convenience) in comparison to the original ASSR algorithm using simulated phantom data for reconstruction. For the case of nonparallel object motion ASSR + shows significant improvements over ASSR, however, its computational complexity is slightly increased due to the broken symmetry of the spiral trajectory

Advanced light water reactor program at ABB-Combustion Engineering Nuclear Power

International Nuclear Information System (INIS)

Cahn, H.

1990-01-01

To meet the needs of Electric Utilities ordering nuclear power plants in the 1990s, ABB-Combustion Engineering is developing two designs which will meet EPRI consensus requirements and new licensing issues. The System 80 Plus design is an evolutionary pressurized water reactor plant modelled after the successful System 80 design in operation in Palo Verde and under construction in Korea. System Plus is currently under review by the US Nuclear Regulatory Commission with final design approval expected in 1991 and design certification in 1992. The Safe Integral Reactor (SIR) plant is a smaller facility with passive safety features and modular construction intended for design certification in the late 1990s. (author)

Optimum Tilt Angle at Tropical Region

Directory of Open Access Journals (Sweden)

S Soulayman

2015-02-01

Full Text Available : One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. Meanwhile, is the rule of thumb, which says that solar collector Equator facing position is the best, is valid for tropical region? Thus, it is required to determine the optimum tilt as for Equator facing and for Pole oriented collectors. In addition, the question that may arise: how many times is reasonable for adjusting collector tilt angle for a definite value of surface azimuth angle? A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle for the solar collector at any latitude. This model was applied for determining optimum tilt angle and orientation in the tropical zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of 11% to 18% more than the case of a solar collector fixed on a horizontal surface.

Crystal structures of the double perovskites Ba2Sr1-x Ca x WO6

International Nuclear Information System (INIS)

Fu, W.T.; Akerboom, S.; IJdo, D.J.W.

2007-01-01

Structures of the double perovskites Ba 2 Sr 1- x Ca x WO 6 have been studied by the profile analysis of X-ray diffraction data. The end members, Ba 2 SrWO 6 and Ba 2 CaWO 6 , have the space group I2/m (tilt system a 0 b - b - ) and Fm3-barm (tilt system a 0 a 0 a 0 ), respectively. By increasing the Ca concentration, the monoclinic structure transforms to the cubic one via the rhombohedral R3-bar phase (tilt system a - a - a - ) instead of the tetragonal I4/m phase (tilt system a 0 a 0 c - ). This observation supports the idea that the rhombohedral structure is favoured by increasing the covalency of the octahedral cations in Ba 2 MM'O 6 -type double perovskites, and disagrees with a recent proposal that the formation of the π-bonding, e.g., d 0 -ion, determines the tetragonal symmetry in preference to the rhombohedral one. - Graphical abstract: Enlarged sections showing the evolution of the basic (222) and (400) reflections in Ba 2 Sr 1- x Ca x WO 6 . Tick marks below are the positions of Bragg's reflections calculated using the space groups I2/m (x=0), R3-bar (x=0.25, 0.5 and 0.75) and Fm3-barm (x=1), respectively

Tilting Saturn without Tilting Jupiter: Constraints on Giant Planet Migration

Science.gov (United States)

Brasser, R.; Lee, Man Hoi

2015-11-01

The migration and encounter histories of the giant planets in our solar system can be constrained by the obliquities of Jupiter and Saturn. We have performed secular simulations with imposed migration and N-body simulations with planetesimals to study the expected obliquity distribution of migrating planets with initial conditions resembling those of the smooth migration model, the resonant Nice model and two models with five giant planets initially in resonance (one compact and one loose configuration). For smooth migration, the secular spin-orbit resonance mechanism can tilt Saturn’s spin axis to the current obliquity if the product of the migration timescale and the orbital inclinations is sufficiently large (exceeding 30 Myr deg). For the resonant Nice model with imposed migration, it is difficult to reproduce today’s obliquity values, because the compactness of the initial system raises the frequency that tilts Saturn above the spin precession frequency of Jupiter, causing a Jupiter spin-orbit resonance crossing. Migration timescales sufficiently long to tilt Saturn generally suffice to tilt Jupiter more than is observed. The full N-body simulations tell a somewhat different story, with Jupiter generally being tilted as often as Saturn, but on average having a higher obliquity. The main obstacle is the final orbital spacing of the giant planets, coupled with the tail of Neptune’s migration. The resonant Nice case is barely able to simultaneously reproduce the orbital and spin properties of the giant planets, with a probability ˜ 0.15%. The loose five planet model is unable to match all our constraints (probability <0.08%). The compact five planet model has the highest chance of matching the orbital and obliquity constraints simultaneously (probability ˜0.3%).

Robust optic alignment in a tilt-free implementation of the Rowland circle spectrometer

Energy Technology Data Exchange (ETDEWEB)

Mortensen, Devon R., E-mail: devon@easyxafs.com [Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States); easyXAFS, LLC, Seattle, WA 98122 (United States); Seidler, Gerald T., E-mail: seidler@uw.edu [Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States)

2017-02-15

Highlights: • A Rowland circle spectrometer using spherically-bend crystal analyzers can be constructed and operated without the use of a two-axis tilt for analyzer alignment. • The resulting instrument allows immediate exchange of fully-tuned optics after a single, initial alignment. • This improvement will help enable the expansion of high-resolution x-ray expansion spectroscopy outside of synchrotron light sources. - Abstract: High-resolution x-ray emission spectroscopy (XES) has recently been demonstrated in the laboratory setting, achieving nearly synchrotron-level count rates despite the use of only conventional x-ray tube sources. This development holds high potential for expanding the reach of x-ray spectroscopies beyond the specialist community of synchrotron users, but comes with its own unique technical challenges for instrument performance and also, just as importantly, for ease of use by non-experts in x-ray science. Here, we address spectrometer design and operations in the context of the imperfect parallelness between the desired crystal plane and the wafer surface in spherically bent crystal analyser (SBCAs), an effect usually called “wafer miscut”. This introduces an ambiguous re-focusing error that typically requires a motorized two-axis tilt stage for fine alignment of the SBCA optic onto the ideal Rowland circle configuration. We instead demonstrate an asymmetric Rowland geometry that eliminates all need for motorized fine-tilt adjustment. We find rapid, extremely reproducible re-insertion of any aligned SBCA, i.e., without the need for any subsequent reoptimization. These improvements strongly benefit the ease of use of laboratory based spectrometers, taking them an important step closer to the level of turnkey operations needed for wide adoption outside of the existing specialist community.

Specifications of the BWR simulator for HAMMLAB 2000

International Nuclear Information System (INIS)

Grini, Rolf-Einar; Miettinen, Jaakko; Nurmilaukas, Pekka; Raussi; Pekka; Saarni, Ray; Stokke; Egil; Soerensen, Aimar; Tiihonen, Olli

1998-02-01

The Boiling Water Reactor (BWR) simulator for HAMMLAB 2000 will be a model of the Swedish plant Forsmark-3. This report gives the specifications of the BWR simulator. The bulk of the report is a copy of the relevant addendum to the contract with the developer, and to the contract with the group of utilities and with ABB Atom. After a general overview, each plant system is described one after the other (using the reference plant system coding), and the simulation of each system is specified. Even the systems that shall not be simulated are included; in those cases the specification is: It is not required that ... is simulated. A list of malfunctions is given, as well as a list of validation transients. Finally the operator interface is specified. (author)

Molecular tilt on monolayer-protected nanoparticles

KAUST Repository

Giomi, L.

2012-02-01

The structure of the tilted phase of monolayer-protected nanoparticles is investigated by means of a simple Ginzburg-Landau model. The theory contains two dimensionless parameters representing the preferential tilt angle and the ratio ε between the energy cost due to spatial variations in the tilt of the coating molecules and that of the van der Waals interactions which favors the preferential tilt. We analyze the model for both spherical and octahedral particles. On spherical particles, we find a transition from a tilted phase, at small ε, to a phase where the molecules spontaneously align along the surface normal and tilt disappears. Octahedral particles have an additional phase at small ε characterized by the presence of six topological defects. These defective configurations provide preferred sites for the chemical functionalization of monolayer-protected nanoparticles via place-exchange reactions and their consequent linking to form molecules and bulk materials. Copyright © EPLA, 2012.

Molecular tilt on monolayer-protected nanoparticles

KAUST Repository

Giomi, L.; Bowick, M. J.; Ma, X.; Majumdar, A.

2012-01-01

The structure of the tilted phase of monolayer-protected nanoparticles is investigated by means of a simple Ginzburg-Landau model. The theory contains two dimensionless parameters representing the preferential tilt angle and the ratio ε between the energy cost due to spatial variations in the tilt of the coating molecules and that of the van der Waals interactions which favors the preferential tilt. We analyze the model for both spherical and octahedral particles. On spherical particles, we find a transition from a tilted phase, at small ε, to a phase where the molecules spontaneously align along the surface normal and tilt disappears. Octahedral particles have an additional phase at small ε characterized by the presence of six topological defects. These defective configurations provide preferred sites for the chemical functionalization of monolayer-protected nanoparticles via place-exchange reactions and their consequent linking to form molecules and bulk materials. Copyright © EPLA, 2012.

An efficient eikonal solver for tilted transversely isotropic and tilted orthorhombic media

KAUST Repository

Waheed, Umair bin

2014-01-01

Computing first-arrival traveltimes in the presence of anisotropy is important for high-end near surface modeling, microseismic source localization, and fractured reservoir characterization. Anisotropy deviating from elliptical anisotropy introduces higher-order nonlinearity into the eikonal equation, which makes solving the equation a challenging task. We address this challenge by iteratively solving a sequence of simpler tilted elliptically anisotropic eikonal equations. At each iteration, the source function is updated to capture the effects due to the higher order nonlinear terms in the anisotropy. We use Aitken extrapolation to speed up the convergence rate of the iterative algorithm. The result is an efficient algorithm for firstarrival traveltime computations in tilted anisotropic media. We demonstrate the proposed method for the tilted transversely isotropic media and the tilted orthorhombic media. Numerical tests show that the proposed method is feasible and produces results that are comparable to wavefield extrapolation, even for strongly anisotropic and complex structures. Therefore, for the cases where one or two-point ray tracing fails, our method may be a potential substitute for computing traveltimes.

Evaluasi Keamanan Sistem Informasi Akademik Menggunakan ISO 17799:2000 (Studi Kasus Pada Peguruan Tinggi X

Directory of Open Access Journals (Sweden)

Mona Permatasari Mokodompit

2017-01-01

Full Text Available The security of an information system in a college is important since the strength of the security system will have a direct impact on the sustainability of the college. Academic information system in college is used in order to meet academic need, and therefore it’s security must be maintained in order to provide useful information for its users. Assessment standard for management information system information security that is internationally recognized is ISO 17799:2000. The research aims to evaluate the security academic information system of University X based on ISO 17799:2000 and to give recommendations to improve the security. This study was conducted using interview techniques, observation and giving questionnaires to managers and users of academic information system of university X. The questionnaire used is a closed questionnaire, which is a broke-down result of ten control clauses of ISO 17799:2000. Answers gathered were then assessed based on established criteria. The results showed that the academic information system security of University X included in the category of less secure, where the result presentation obtained was 59%. In order to increase the security, University X must give special attention to work on the security policy, security organization, personnel security, physical and environmental security, communication and operation management, access control and compliance.

Fluid observers and tilting cosmology

International Nuclear Information System (INIS)

Coley, A A; Hervik, S; Lim, W C

2006-01-01

We study perfect fluid cosmological models with a constant equation of state parameter γ in which there are two naturally defined timelike congruences, a geometrically defined geodesic congruence and a non-geodesic fluid congruence. We establish an appropriate set of boost formulae relating the physical variables, and consequently the observed quantities, in the two frames. We study expanding spatially homogeneous tilted perfect fluid models, with an emphasis on future evolution with extreme tilt. We show that for ultra-radiative equations of state (i.e. γ > 4/3), generically the tilt becomes extreme at late times and the fluid observers will reach infinite expansion within a finite proper time and experience a singularity similar to that of the big rip. In addition, we show that for sub-radiative equations of state (i.e. γ < 4/3), the tilt can become extreme at late times and give rise to an effective quintessential equation of state. To establish the connection with phantom cosmology and quintessence, we calculate the effective equation of state in the models under consideration and we determine the future asymptotic behaviour of the tilting models in the fluid frame variables using the boost formulae. We also discuss spatially inhomogeneous models and tilting spatially homogeneous models with a cosmological constant

Evaluating Tilt for Wind Farms: Preprint

Energy Technology Data Exchange (ETDEWEB)

Annoni, Jennifer; Scholbrock, Andrew; Churchfield, Matthew; Fleming, Paul

2017-06-29

The objective of this work is to demonstrate the feasibility of tilt in a wind plant. Tilt control, much like other wind plant control strategies, has the potential to improve the performance of a wind plant. Tilt control uses the tilt angle of the turbine to direct the wake above or below the downstream turbines. This paper presents a study of tilt in two- and threeturbine arrays. Specifically, the authors show that the power production of a two-turbine array can be increased by tilting turbines in a specific orientation. When adding more turbines, as is shown with the three-turbine array, the overall percentage of power gain increases. This outcome deviates from some of the results seen in typical wind plant control strategies. Finally, we discuss the impact this type of control strategy has on the aerodynamics in a wind plant. This analysis demonstrates that a good understanding of wake characteristics is necessary to improve the plant's performance. A tilt strategy such as the one presented in this paper may have implications for future control/optimization studies including optimization of hub heights in a wind plant and analysis of deep array effects.

Direct cone beam SPECT reconstruction with camera tilt

International Nuclear Information System (INIS)

Jianying Li; Jaszczak, R.J.; Greer, K.L.; Coleman, R.E.; Zongjian Cao; Tsui, B.M.W.

1993-01-01

A filtered backprojection (FBP) algorithm is derived to perform cone beam (CB) single-photon emission computed tomography (SPECT) reconstruction with camera tilt using circular orbits. This algorithm reconstructs the tilted angle CB projection data directly by incorporating the tilt angle into it. When the tilt angle becomes zero, this algorithm reduces to that of Feldkamp. Experimentally acquired phantom studies using both a two-point source and the three-dimensional Hoffman brain phantom have been performed. The transaxial tilted cone beam brain images and profiles obtained using the new algorithm are compared with those without camera tilt. For those slices which have approximately the same distance from the detector in both tilt and non-tilt set-ups, the two transaxial reconstructions have similar profiles. The two-point source images reconstructed from this new algorithm and the tilted cone beam brain images are also compared with those reconstructed from the existing tilted cone beam algorithm. (author)

L’entreprise archivistique de Jean de Cirey, abbé de Cîteaux (1476-1501. Le dossier documentaire de la seigneurie de Villars en Côte-d’Or

Directory of Open Access Journals (Sweden)

Coraline Rey

2010-10-01

Full Text Available L'abbé Jean de Cirey (1476-1501 a réalisé un ambitieux projet archivistique, notamment en faisant trier et classer les chartes, et en assurant leur préservation par la rédaction de cartulaires. De cette entreprise, les Archives départementales de Côte-d’Or conservent aujourd’hui neuf grands registres de parchemin (320/325 x 240/250 mm appelés « cartulaires de Jean de Cirey », formant un cartulaire général de l’abbaye de Cîteaux. Ce service d’archives possède aussi quinze cartulaires cisterc...

An Approximate Cone Beam Reconstruction Algorithm for Gantry-Tilted CT Using Tangential Filtering

Directory of Open Access Journals (Sweden)

Ming Yan

2006-01-01

Full Text Available FDK algorithm is a well-known 3D (three-dimensional approximate algorithm for CT (computed tomography image reconstruction and is also known to suffer from considerable artifacts when the scanning cone angle is large. Recently, it has been improved by performing the ramp filtering along the tangential direction of the X-ray source helix for dealing with the large cone angle problem. In this paper, we present an FDK-type approximate reconstruction algorithm for gantry-tilted CT imaging. The proposed method improves the image reconstruction by filtering the projection data along a proper direction which is determined by CT parameters and gantry-tilted angle. As a result, the proposed algorithm for gantry-tilted CT reconstruction can provide more scanning flexibilities in clinical CT scanning and is efficient in computation. The performance of the proposed algorithm is evaluated with turbell clock phantom and thorax phantom and compared with FDK algorithm and a popular 2D (two-dimensional approximate algorithm. The results show that the proposed algorithm can achieve better image quality for gantry-tilted CT image reconstruction.

ABB engagement in efforts to improve the safety of RBMK reactors

International Nuclear Information System (INIS)

Tiren, L.I.; Bioere, S.; Molin, J.

1993-01-01

ABB Atom is engaged in safety analysis for the Ignalinsk (RBMK) nuclear power plant. The analysis is done within the framework of two different initiatives of the Swedish Nuclear Power Inspectorate, namely: probabilistic safety assessment, i.e. the BARSELINA project, and analysis of containment safety issues. The aim is to enable decisions to be made for specific hardware modifications. The following items were considered by the Swedish Nuclear Power Inspectorate to be the most significant with regard to safety and were thus selected for further study or action: nondestructive testing of primary system components, fire and flooding protection, pressure relief from the reactor cavity in certain accident sequences, Accident Localization System improvements, and a separate auxiliary feedwater system. (Z.S.) 1 fig

Unilateral otolith centrifugation by head tilt.

Science.gov (United States)

Winters, Stephanie M; Bos, Jelte E; Klis, Sjaak F L

2014-01-01

To test for otolith asymmetries, several studies described horizontal translation of the body and head en bloc during fast vertical axis rotation. This stimulus causes one otolithic organ to rotate on-axis, and the other to experience centripetal acceleration. To test a new, more simple method of unilateral stimulation with head tilt and the body remaining on axis. During stationary and during 360 deg/s rotation, 12 healthy blindfolded subjects had their heads tilted 30 degrees sideways, positioning one otolithic organ on the axis of rotation after the other. The haptic subjective vertical (SV) was recorded several times by means of a manually adjustable rod. It was found that during stationary the SV tilted about 4 degrees on average in the direction of the head. During rotation, the SV tilted about 9 degrees on average. We therefore estimate the effect of eccentric otolith rotation to be 5 degrees on average. Tilt of the subjective vertical induced by head tilt during on-axis body rotation can provide a relatively uncomplicated alternative to test unilateral otolithic function as compared to body and head translation during rotation. Moreover, unlike eccentric rotation of the entire body, somatosensory cues are minimized by keeping the body fixed on axis and by subtracting the effect of head tilt per se.

A COMMON SOURCE OF ACCRETION DISK TILT

International Nuclear Information System (INIS)

Montgomery, M. M.; Martin, E. L.

2010-01-01

Many different system types retrogradely precess, and retrograde precession could be from a tidal torque by the secondary on a misaligned accretion disk. However, a source that causes and maintains disk tilt is unknown. In this work, we show that accretion disks can tilt due to a force called lift. Lift results from differing gas stream supersonic speeds over and under an accretion disk. Because lift acts at the disk's center of pressure, a torque is applied around a rotation axis passing through the disk's center of mass. The disk responds to lift by pitching around the disk's line of nodes. If the gas stream flow ebbs, then lift also ebbs and the disk attempts to return to its original orientation. To first approximation, lift does not depend on magnetic fields or radiation sources but does depend on the mass and the surface area of the disk. Also, for disk tilt to be initiated, a minimum mass transfer rate must be exceeded. For example, a 10 -11 M sun disk around a 0.8 M sun compact central object requires a mass transfer rate greater than ∼ 8 x 10 -11 M sun yr -1 , a value well below the known mass transfer rates in cataclysmic variable dwarf novae systems that retrogradely precess and exhibit negative superhumps in their light curves and a value well below mass transfer rates in protostellar-forming systems.

Smart X-ray optics

International Nuclear Information System (INIS)

Michette, A G; Pfauntsch, S J; Sahraei, S; Shand, M; Morrison, G R; Hart, D; Vojnovic, B; Stevenson, T; Parkes, W; Dunare, C; Willingale, R; Feldman, C; Button, T; Zhang, D; Rodriguez-Sanmartin, D; Wang, H

2009-01-01

This paper describes reflective adaptive/active optics for applications including studies of biological radiation damage. The optics work on the polycapillary principle, but use arrays of channels in thin silicon. For optimum performance the x-rays should reflect once off a channel wall in each of two successive arrays. This reduces aberrations since then the Abbe sine condition is approximately satisfied. Adaptivity is achieved by flexing the arrays via piezo actuation, providing further aberration reduction and controllable focal length.

Finite element Fourier and Abbe transform methods for generalization of aperture function and geometry in Fraunhofer diffraction theory

International Nuclear Information System (INIS)

Kraus, H.G.

1991-01-01

This paper discusses methods for calculating Fraunhofer intensity fields resulting from diffraction through one- and two-dimensional apertures are presented. These methods are based on the geometric concept of finite elements and on Fourier and Abbe transforms. The geometry of the two-dimensional diffracting aperture(s) is based on biquadratic isoparametric elements, which are used to define aperture(s) of complex geometry. These elements are also used to build complex amplitude and phase functions across the aperture(s) which may be of continuous or discontinuous form. The transform integrals are accurately and efficiently integrated numerically using Gaussian quadrature. The power of these methods is most evident in two dimensions, where several examples are presented which include secondary obstructions, straight and curved secondary spider supports, multiple-mirror arrays, synthetic aperture arrays, segmented mirrors, apertures covered by screens, apodization, and phase plates. Typically, the finite element Abbe transform method results in significant gains in computational efficiency over the finite element Fourier transform method, but is also subject to some loss in generality

Influence of forming conditions on fiber tilt

Science.gov (United States)

David W. Vahey; John M. Considine; Michael A. and MacGregor

2013-01-01

Fiber tilt describes the projection of fiber length in the thickness direction of paper. The projection is described by the tilt angle of fibers with respect to the plane of the sheet. A simple model for fiber tilt is based on jet-to-wire velocity differential in combination with cross-flows on the wire. The tilt angle of a fiber is found to vary as the sine of its in-...

Realization of Tip Tilting By 8-Step Line Tilting

International Nuclear Information System (INIS)

Chen Yingtian; Zhang Yang; Lim, Boon Ham; Lim, Chen Sin; Hu Sen; Ho, Tso-Hsiu

2009-01-01

By direct calculation of rotation matrices of SO(3), we show how certain specific sequence of eight consecutive rotations of digital angles can yield a tilting of a facet mirror. We also design a detailed program specifically to tilt an array of mirrors from planar orientation to the required focusing orientation. We describe how to use the 8-step to realize the focusing of the mirror array. We have found, in our designed program, an important feature of row-sharing during the rotations for the columns and similarly the column-sharing during the rotations for the row. This feature can save a lot of operating time during the actual realization of the mechanical movements.

Tilting mode in field-reversed configurations

International Nuclear Information System (INIS)

Schwarzmeier, J.L.; Barnes, D.C.; Lewis, H.R.; Seyler, C.E.; Shestakov, A.I.

1982-01-01

Field Reversed Configurations (FRCs) experimentally have exhibited remarkable stability on the magnetohydrodynamic (MHD) timescale, despite numerous MHD calculations showing FRCs to be unstable. It is easy to believe that local modes are stabilized by finite Larmor radius (FLR) effects, but more puzzling is the apparent stability of FRCs against global modes, where one would expect FLR effects to be less important. In this paper we study the tilting mode, which MHD has shown to be a rapidly growing global mode. The tilting mode in FRCs is driven by the pressure gradient, and magnetic compression and field line bending are the stabilizing forces. A schematic of the evolution of the tilting mode is shown. The tilting mode is considered dangerous, because it would lead to rapid tearing across the separatrix. Unlike spheromaks, the tilting mode in FRCs has a separatrix that is fixed in space, so that the mode is strictly internal

Why is it so difficult to tilt Uranus?

Science.gov (United States)

Rogoszinski, Zeeve; Hamilton, Douglas

2018-04-01

The leading hypothesis for the origin of Uranus' large obliquity (98°) is a polar strike from an Earth sized object, but to tilt Saturn similarly would require an impactor roughly 10x as massive. A more likely cause for Saturn's tilt (27°) is a spin-orbit resonance with Neptune (Ward & Hamilton, 2004; Hamilton & Ward, 2004); might the same process work for Uranus? It initially seems unlikely, as at its current location Uranus' axial precession period is too long to resonate with any of the giant planets' orbital precession frequencies. If we place Uranus between Jupiter and Saturn, however, then Uranus' spin axis would precess much more quickly. Thommes et al. (1999, 2002, 2003) first postulated that Uranus and Neptune were formed between Jupiter and Saturn because the conditions there allow the ice giants to be built rapidly. A resonance for our closer Uranus still requires a distant planet, nevertheless, a condition that can be satisfied if Neptune is ejected from Jupiter and Saturn first with Uranus following significantly later. This scenario, while contrived, is consistent with at least some versions of the Nice model and allows us to fully test the resonance hypothesis. We discovered that even with these optimistic assumptions, i) a resonance capture requires a migration timescale on the order of 100 Myr, and ii) it is impossible to tilt Uranus past 90°. Increasing Neptune's migration speed precludes resonant capture, and instead results in a resonance kick. In the most favorable cases, a resonance kick could raise Uranus' obliquity by 40° on a time span of about 50 Myr. We conclude that even in our best scenario, a resonance cannot fully account for Uranus' tilt. We have investigated some scenarios that include both resonances and collisions, and will report on our findings.

Performance analysis of power swing blocking feature in ABB 670 series impedance relays

Directory of Open Access Journals (Sweden)

Maciej Łosiński

2012-12-01

Full Text Available This paper presents test results of a distance protection’s PSD power swing detection feature in ABB 670 series relays. A RED670 relay was tested, which is part of the hydroelectric set protection in Żarnowiec Pumped Storage Plant. The power swing blocking feature’s performance was analysed on the basis of the results of object tests made with an Omicron digital tester. Also presented are simulation results that illustrate the PSD feature’s response to power swings caused by a disturbance in the power system. It is also shown how a distance protection may react to the same fault, depending on its settings.

Tilt measurements at Vulcano Island

Directory of Open Access Journals (Sweden)

B. Saraceno

2007-06-01

Full Text Available A network of tiltmeters has been operational on Vulcano Island for numerous years. At present, the network comprises five functioning borehole stations, four of which are installed at 8-10 m and allow recording very stable, high precision signals with very low noise. We report observations over the last 12 years that illustrate impulsive variations linked to seismicity and long-term (several years trends in the signals. We suggest a relationship between tilt changes correlated to the strongest regional seismic events and site acceleration; long-term tilt variations analyzed in combination with other ground deformation data seem to represent the evidence of a contraction of the La Fossa cone. We also analyzed how the tilt device has the capability to detect possible magma migrations; we considered previous studies that have imaged spatially well-defined levels of magma accumulation beneath La Fossa, and Vulcanello; we concluded that the Vulcano tilt network should be capable of detecting the upward migration of small magma volumes. Finally, we show that no evidence of changes are visible on tilt signals during anomalous degassing episodes (linked to a building up input of magmatic fluids at the La Fossa thereby evidencing that no magma migration occurred during such events.

Ferroelectric and octahedral tilt twin disorder and the lead-free piezoelectric, sodium potassium niobate system

International Nuclear Information System (INIS)

Schiemer, Jason; Withers, Ray L.; Liu, Yun; Yi, Zhiguo

2012-01-01

Using electron diffraction, trends in the local structural behaviour of the K x Na 1−x NbO 3 (KNN x) ‘solid solution’ system are investigated and interpreted using an order/disorder based theoretical framework. At room temperature, electron diffraction shows a single plane of transverse polarised, diffuse intensity perpendicular to [0 1 0] p ⁎ (p for parent sub-structure) across the entire phase diagram, indicative of ferroelectric disorder along the [0 1 0] p direction co-existing with long range ferroelectric order along the orthogonal [1 0 0] p and [0 0 1] p directions. An additional characteristic pattern of diffuse scattering is also observed, involving rods of diffuse intensity running along the [1 0 0] p * and [0 0 1] p * directions of the perovskite sub-structure and indicative of octahedral tilt disorder about the [1 0 0] p and [0 0 1] p axes co-existing with long range ordered octahedral tilting around the [0 1 0] p direction. A possible crystal chemical explanation for the existence of this latter octahedral tilt disorder is explored through bond valence sum calculations. The possible influence of both types of disorder on the previously refined, room temperature space group/s and average crystal structure/s is examined. - Graphical abstract: [−3,0.−1]p zone axis EDP of K 0.46 Na 0.54 NbO 3 indexed according to both the relevant Pcm21 space groups (no subscripts) and the parent perovskite subcell (denoted by a subscript p). Highlights: ► Characterises ferroelectric and octahedral tilt disorder in the KNN solid solution. ► Discusses the possible driving forces for this disorder. ► Discusses the implications of this disorder for physical properties. ► Discusses the effects of this disorder on powder diffraction data.

"CONFIRMATORY SURVEY RESULTS FOR THE ABB COMBUSTION ENGINEERING SITE WINDSOR, CONNECTICUT DCN 5158-SR-02-2

Energy Technology Data Exchange (ETDEWEB)

ADAMS, WADE C

2013-03-25

The objectives of the confirmatory activities were to provide independent contractor field data reviews and to generate independent radiological data for use by the NRC in evaluating the adequacy and accuracy of the contractor's procedures and FSS results. ORAU reviewed ABB CE's decommissioning plan, final status survey plan, and the applicable soil DCGLs, which were developed based on an NRC-approved radiation dose assessment. The surveys include gamma surface scans, gamma direct measurements, and soil sampling.

Lifting to cluster-tilting objects in higher cluster categories

OpenAIRE

Liu, Pin

2008-01-01

In this note, we consider the $d$-cluster-tilted algebras, the endomorphism algebras of $d$-cluster-tilting objects in $d$-cluster categories. We show that a tilting module over such an algebra lifts to a $d$-cluster-tilting object in this $d$-cluster category.

Athermalization and achromatization of visible/SWIR optics using instantaneous Abbe number

Science.gov (United States)

Ramsey, J. L.

2017-11-01

With the move to more and more lightweight and cost-effective design, a move to multiband or multi-spectral optics is required. These systems are becoming more prevalent in the market as new detector technologies have been developed. However, the lens designs are only starting to be considered with the addition of new materials in the MWIR and the LWIR. For the VIS/SWIR region the designs have been possible, but a lack of detector technology has resulted in few designs being considered for actual manufacturing. These designs are also difficult due to changes in the Abbe number in the different wavebands. Where the glass map is robust in the visible region, there exists a lack of crown glasses in the SWIR, and one is left with mostly flint glasses. This proves challenging from a chromatic perspective. The challenge becomes even more difficult if one wants to incorporate athermalization.

A kilohertz picosecond x-ray pulse generation scheme

International Nuclear Information System (INIS)

Guo, W.; Borland, M.; Harkay, K. C.; Wang, C.-X.; Yang, B.

2007-01-01

The duration of the x-ray pulse generated at a synchrotron light source is typically tens of picoseconds. Shorter pulses are highly desired by the users. In electron storage rings, the vertical beam size is usually orders of magnitude less than the bunch length due to radiation damping; therefore, a shorter pulse can be obtained by slitting the vertically tilted bunch. Zholents proposed tilting the bunch using rf deflection. We found that tilted bunches can also be generated by a dipole magnet kick. A vertical tilt is developed after the kick in the presence of nonzero chromaticity. The tilt was successfully observed and a 4.2-ps pulse was obtained from a 27-ps electron bunch at the Advanced Photon Source. Based on this principle we propose a short-pulse generation scheme that produces picosecond x-ray pulses at a repetition rate of 1 utilde2 kHz, which can be used for pump-probe experiments

ABB.-Combustion Engineering's Experience in Nuclear Power Plant Engineering and Construction in Korea

International Nuclear Information System (INIS)

Veris, James W.

1992-01-01

The Yonggwang Nuclear Project is a milestone project for the Korean Nuclear Industry. The Project has the two objectives of obtaining self-reliance in all aspects of nuclear technology and of constructing two modern nuclear power plants under the leadership of Korean companies acting as prime contractors. ABB.-Combustion Engineering 1000 MW System 80+ TM was chosen in 1987 as the NSLS design to meet these two objectives. This paper summarizers the significant experiences and lessons learned through the first four years of the Project as well as identifying implications for such future projects. The unique challenges of the project are identified and an evaluation of the experiences in the technology, self-reliance program and in the design and manufacturing processes will be made

Optic flow induced self-tilt perception

NARCIS (Netherlands)

Bos, J.E.

2008-01-01

Roll optic flow induces illusory self-tilt in humans. As far as the mechanism underlying this visual-vestibular interaction is understood, larger angles of self-tilt are predicted than observed. It is hypothesized that the discrepancy can be explained by idiotropic (i.e., referring to a personal

Spheromak tilting and its stability control

International Nuclear Information System (INIS)

Hayashi, T.; Sato, T.

1983-01-01

Spheromak tilting instability was studied. A numerical technique to create a rather arbitrarily-shaped spheromak like the one with a flux hole was investigated. The dynamics governing the tilting instability, namely, the influence of the magnetic index, the toroidal current (q-profile) and the resistivity upon the tilting growth rate, and the roles of magnetc reconnection upon the nonlinear development were studied. The best way to control the tilting instability was invented. The stabilizing effects of the vertical wall, the isolated conducting cylindrical belt, and the horizontal wall were studied. Central pole stabilization was also investigated. The influence of the wall condition, namely, whether the wall acted as a flux conserver in the spheromak creation stage or not is discussed. The present study has shown that the three- dimensional simulation is indeed useful and practical in not only studying the underlying physics but also finding a stabilization technique of spheromaks. (Kato, T.)

Mapping of moveout in tilted transversely isotropic media

KAUST Repository

Stovas, A.; Alkhalifah, Tariq Ali

2013-01-01

The computation of traveltimes in a transverse isotropic medium with a tilted symmetry axis tilted transversely isotropic is very important both for modelling and inversion. We develop a simple analytical procedure to map the traveltime function from a transverse isotropic medium with a vertical symmetry axis (vertical transversely isotropic) to a tilted transversely isotropic medium by applying point-by-point mapping of the traveltime function. This approach can be used for kinematic modelling and inversion in layered tilted transversely isotropic media. © 2013 European Association of Geoscientists & Engineers.

Mapping of moveout in tilted transversely isotropic media

KAUST Repository

Stovas, A.

2013-09-09

The computation of traveltimes in a transverse isotropic medium with a tilted symmetry axis tilted transversely isotropic is very important both for modelling and inversion. We develop a simple analytical procedure to map the traveltime function from a transverse isotropic medium with a vertical symmetry axis (vertical transversely isotropic) to a tilted transversely isotropic medium by applying point-by-point mapping of the traveltime function. This approach can be used for kinematic modelling and inversion in layered tilted transversely isotropic media. © 2013 European Association of Geoscientists & Engineers.

Introducer Curving Technique for the Prevention of Tilting of Transfemoral Gunther Tulip Inferior Vena Cava Filter

International Nuclear Information System (INIS)

Xiao, Liang; Shen, Jing; Tong, Jia Jie; Huang, De Sheng

2012-01-01

To determine whether the introducer curving technique is useful in decreasing the degree of tilting of transfemoral Tulip filters. The study sample group consisted of 108 patients with deep vein thrombosis who were enrolled and planned to undergo thrombolysis, and who accepted transfemoral Tulip filter insertion procedure. The patients were randomly divided into Group C and Group T. The introducer curving technique was Adopted in Group T. The post-implantation filter tilting angle (ACF) was measured in an anteroposterior projection. The retrieval hook adhering to the vascular wall was measured via tangential cavogram during retrieval. The overall average ACF was 5.8 ± 4.14 degrees. In Group C, the average ACF was 7.1 ± 4.52 degrees. In Group T, the average ACF was 4.4 ± 3.20 degrees. The groups displayed a statistically significant difference (t = 3.573, p = 0.001) in ACF. Additionally, the difference of ACF between the left and right approaches turned out to be statistically significant (7.1 ± 4.59 vs. 5.1 ± 3.82, t = 2.301, p = 0.023). The proportion of severe tilt (ACF ≥ 10 degree) in Group T was significantly lower than that in Group C (9.3% vs. 24.1%, X 2 = 4.267, p = 0.039). Between the groups, the difference in the rate of the retrieval hook adhering to the vascular wall was also statistically significant (2.9% vs. 24.2%, X 2 = 5.030, p = 0.025). The introducer curving technique appears to minimize the incidence and extent of transfemoral Tulip filter tilting.

Introducer Curving Technique for the Prevention of Tilting of Transfemoral Gunther Tulip Inferior Vena Cava Filter

Energy Technology Data Exchange (ETDEWEB)

Xiao, Liang; Shen, Jing; Tong, Jia Jie [The First Hospital of China Medical University, Shenyang (China); Huang, De Sheng [College of Basic Medical Science, China Medical University, Shenyang (China)

2012-07-15

To determine whether the introducer curving technique is useful in decreasing the degree of tilting of transfemoral Tulip filters. The study sample group consisted of 108 patients with deep vein thrombosis who were enrolled and planned to undergo thrombolysis, and who accepted transfemoral Tulip filter insertion procedure. The patients were randomly divided into Group C and Group T. The introducer curving technique was Adopted in Group T. The post-implantation filter tilting angle (ACF) was measured in an anteroposterior projection. The retrieval hook adhering to the vascular wall was measured via tangential cavogram during retrieval. The overall average ACF was 5.8 {+-} 4.14 degrees. In Group C, the average ACF was 7.1 {+-} 4.52 degrees. In Group T, the average ACF was 4.4 {+-} 3.20 degrees. The groups displayed a statistically significant difference (t = 3.573, p = 0.001) in ACF. Additionally, the difference of ACF between the left and right approaches turned out to be statistically significant (7.1 {+-} 4.59 vs. 5.1 {+-} 3.82, t = 2.301, p = 0.023). The proportion of severe tilt (ACF {>=} 10 degree) in Group T was significantly lower than that in Group C (9.3% vs. 24.1%, X{sup 2} = 4.267, p = 0.039). Between the groups, the difference in the rate of the retrieval hook adhering to the vascular wall was also statistically significant (2.9% vs. 24.2%, X{sup 2} = 5.030, p = 0.025). The introducer curving technique appears to minimize the incidence and extent of transfemoral Tulip filter tilting.

Development and applications of a two-dimensional tip-tilting stage system with nanoradian-level positioning resolution

Energy Technology Data Exchange (ETDEWEB)

Shu Deming, E-mail: shu@aps.anl.gov [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Lee, Wah-Keat; Liu, Wenjun [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Ice, Gene E. [MST Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6132 (United States); Shvyd' ko, Yuri; Kim, Kwang-Je [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

2011-09-01

In this paper, designs of a novel rotary weak-link stage for a vertical rotation axis and a two-dimensional tip-tilting system are presented. Applications of these new stage systems include: an advanced X-ray stereo imaging instrument for particle tracking velocimetry, an alignment stage system for hard X-ray nano-focusing Montel mirror optics, and an ultra-precision crystal manipulator for cryo-cooling optical cavities of an X-ray free-electron-laser oscillator (XFELO).

Transient cardio-respiratory responses to visually induced tilt illusions

Science.gov (United States)

Wood, S. J.; Ramsdell, C. D.; Mullen, T. J.; Oman, C. M.; Harm, D. L.; Paloski, W. H.

2000-01-01

Although the orthostatic cardio-respiratory response is primarily mediated by the baroreflex, studies have shown that vestibular cues also contribute in both humans and animals. We have demonstrated a visually mediated response to illusory tilt in some human subjects. Blood pressure, heart and respiration rate, and lung volume were monitored in 16 supine human subjects during two types of visual stimulation, and compared with responses to real passive whole body tilt from supine to head 80 degrees upright. Visual tilt stimuli consisted of either a static scene from an overhead mirror or constant velocity scene motion along different body axes generated by an ultra-wide dome projection system. Visual vertical cues were initially aligned with the longitudinal body axis. Subjective tilt and self-motion were reported verbally. Although significant changes in cardio-respiratory parameters to illusory tilts could not be demonstrated for the entire group, several subjects showed significant transient decreases in mean blood pressure resembling their initial response to passive head-up tilt. Changes in pulse pressure and a slight elevation in heart rate were noted. These transient responses are consistent with the hypothesis that visual-vestibular input contributes to the initial cardiovascular adjustment to a change in posture in humans. On average the static scene elicited perceived tilt without rotation. Dome scene pitch and yaw elicited perceived tilt and rotation, and dome roll motion elicited perceived rotation without tilt. A significant correlation between the magnitude of physiological and subjective reports could not be demonstrated.

Motion perception during tilt and translation after space flight

Science.gov (United States)

Clément, Gilles; Wood, Scott J.

2013-11-01

Preliminary results of an ongoing study examining the effects of space flight on astronauts' motion perception induced by independent tilt and translation motions are presented. This experiment used a sled and a variable radius centrifuge that translated the subjects forward-backward or laterally, and simultaneously tilted them in pitch or roll, respectively. Tests were performed on the ground prior to and immediately after landing. The astronauts were asked to report about their perceived motion in response to different combinations of body tilt and translation in darkness. Their ability to manually control their own orientation was also evaluated using a joystick with which they nulled out the perceived tilt while the sled and centrifuge were in motion. Preliminary results confirm that the magnitude of perceived tilt increased during static tilt in roll after space flight. A deterioration in the crewmember to control tilt using non-visual inertial cues was also observed post-flight. However, the use of a tactile prosthesis indicating the direction of down on the subject's trunk improved manual control performance both before and after space flight.

Highly tilted liquid crystalline materials possessing a direct phase transition from antiferroelectric to isotropic phase

Energy Technology Data Exchange (ETDEWEB)

Milewska, K.; Drzewiński, W. [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Czerwiński, M., E-mail: mczerwinski@wat.edu.pl [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Dąbrowski, R. [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Piecek, W. [Institute of Applied Physics, Military University of Technology, 00-908 Warsaw (Poland)

2016-03-01

Pure compounds and multicomponent mixtures with a broad temperature range of high tilted liquid crystalline antiferroelectric phase and a direct phase transition from antiferroelectric to isotropic phase, were obtained. X-ray diffraction analysis confirms these kinds of materials form a high tilted anticlinic phase, with a fixed layer spacing and very weak dependency upon temperature, after the transition from the isotropic phase. Due to this, not only pure orthoconic antiferroelectric liquid crystals but also those with a moderate tilt should generate a good dark state. Furthermore, due to the increased potential for forming anticlinic forces, such materials could minimize a commonly observed asymmetry of a rise and fall switching times at a surface stabilized geometry. - Highlights: • The new class of liquid crystalline materials with the direct SmC{sub A}*. • Iso phase transition were obtained. • Materials possess the layer spacing fixed and very weak dependent upon temperature. • Smectic layers without shrinkage are observed. • A good dark state can be generate in SSAFLC.

Perception of self-tilt in a true and illusory vertical plane

Science.gov (United States)

Groen, Eric L.; Jenkin, Heather L.; Howard, Ian P.; Oman, C. M. (Principal Investigator)

2002-01-01

A tilted furnished room can induce strong visual reorientation illusions in stationary subjects. Supine subjects may perceive themselves upright when the room is tilted 90 degrees so that the visual polarity axis is kept aligned with the subject. This 'upright illusion' was used to induce roll tilt in a truly horizontal, but perceptually vertical, plane. A semistatic tilt profile was applied, in which the tilt angle gradually changed from 0 degrees to 90 degrees, and vice versa. This method produced larger illusory self-tilt than usually found with static tilt of a visual scene. Ten subjects indicated self-tilt by setting a tactile rod to perceived vertical. Six of them experienced the upright illusion and indicated illusory self-tilt with an average gain of about 0.5. This value is smaller than with true self-tilt (0.8), but comparable to the gain of visually induced self-tilt in erect subjects. Apparently, the contribution of nonvisual cues to gravity was independent of the subject's orientation to gravity itself. It therefore seems that the gain of visually induced self-tilt is smaller because of lacking, rather than conflicting, nonvisual cues. A vector analysis is used to discuss the results in terms of relative sensory weightings.

Pick-and-place process for sensitivity improvement of the capacitive type CMOS MEMS 2-axis tilt sensor

Science.gov (United States)

Chang, Chun-I.; Tsai, Ming-Han; Liu, Yu-Chia; Sun, Chih-Ming; Fang, Weileun

2013-09-01

This study exploits the foundry available complimentary metal-oxide-semiconductor (CMOS) process and the packaging house available pick-and-place technology to implement a capacitive type micromachined 2-axis tilt sensor. The suspended micro mechanical structures such as the spring, stage and sensing electrodes are fabricated using the CMOS microelectromechanical systems (MEMS) processes. A bulk block is assembled onto the suspended stage by pick-and-place technology to increase the proof-mass of the tilt sensor. The low temperature UV-glue dispensing and curing processes are employed to bond the block onto the stage. Thus, the sensitivity of the CMOS MEMS capacitive type 2-axis tilt sensor is significantly improved. In application, this study successfully demonstrates the bonding of a bulk solder ball of 100 µm in diameter with a 2-axis tilt sensor fabricated using the standard TSMC 0.35 µm 2P4M CMOS process. Measurements show the sensitivities of the 2-axis tilt sensor are increased for 2.06-fold (x-axis) and 1.78-fold (y-axis) after adding the solder ball. Note that the sensitivity can be further improved by reducing the parasitic capacitance and the mismatch of sensing electrodes caused by the solder ball.

Vortex trapping by tilted columnar defects

International Nuclear Information System (INIS)

Baladie, I.; Buzdin, A.

2000-01-01

The irradiation of high-T c superconductors by inclined heavy-ion beam can create columnar defects (CD's) practically at any angle towards the crystal c axis. We calculate the energy of a tilted vortex trapped on an inclined columnar defect within the framework of an electromagnetic model. Under a weak perpendicular magnetic field, and if the CD radius is larger than the superconducting coherence length, vortices always prefer to be on a tilted CD than to be aligned along the external field. We calculate also the interaction energy between two tilted vortices and find that large attractive regions appear. In particular, in the plane defined by c axis and the CD axis, tilted vortices attract each other at long distances, leading to the formation of vortex chains. The equilibrium distance between vortices in a chain is of the order of the magnitude of the in-plane London penetration depth. The existence of the inclined trapped vortices could be revealed by torque measurements, and could also lead to the anisotropy of the in-plane resistivity and the critical current

Behavior of Tilted Angle Shear Connectors

Science.gov (United States)

Khorramian, Koosha; Maleki, Shervin; Shariati, Mahdi; Ramli Sulong, N. H.

2015-01-01

According to recent researches, angle shear connectors are appropriate to transfer longitudinal shear forces across the steel-concrete interface. Angle steel profile has been used in different positions as L-shaped or C-shaped shear connectors. The application of angle shear connectors in tilted positions is of interest in this study. This study investigates the behaviour of tilted-shaped angle shear connectors under monotonic loading using experimental push out tests. Eight push-out specimens are tested to investigate the effects of different angle parameters on the ultimate load capacity of connectors. Two different tilted angles of 112.5 and 135 degrees between the angle leg and steel beam are considered. In addition, angle sizes and lengths are varied. Two different failure modes were observed consisting of concrete crushing-splitting and connector fracture. By increasing the size of connector, the maximum load increased for most cases. In general, the 135 degrees tilted angle shear connectors have a higher strength and stiffness than the 112.5 degrees type. PMID:26642193

Behavior of Tilted Angle Shear Connectors.

Directory of Open Access Journals (Sweden)

Koosha Khorramian

Full Text Available According to recent researches, angle shear connectors are appropriate to transfer longitudinal shear forces across the steel-concrete interface. Angle steel profile has been used in different positions as L-shaped or C-shaped shear connectors. The application of angle shear connectors in tilted positions is of interest in this study. This study investigates the behaviour of tilted-shaped angle shear connectors under monotonic loading using experimental push out tests. Eight push-out specimens are tested to investigate the effects of different angle parameters on the ultimate load capacity of connectors. Two different tilted angles of 112.5 and 135 degrees between the angle leg and steel beam are considered. In addition, angle sizes and lengths are varied. Two different failure modes were observed consisting of concrete crushing-splitting and connector fracture. By increasing the size of connector, the maximum load increased for most cases. In general, the 135 degrees tilted angle shear connectors have a higher strength and stiffness than the 112.5 degrees type.

Magnetic field orientation dependence of flux pinning in (Gd,Y)Ba2Cu3O7-x coated conductor with tilted lattice and nanostructures

International Nuclear Information System (INIS)

Zhang, Y.; Specht, E.D.; Cantoni, C.; Christen, D.K.; Thompson, J.R.; Sinclair, J.W.; Goyal, A.; Zuev, Y.L.; Aytug, T.; Paranthaman, M.P.; Chen, Y.; Selvamanickam, V.

2009-01-01

The dependence of the critical current density (J c ) on the orientation of an applied magnetic field was studied for a prototype (Gd,Y)Ba 2 Cu 3 O 7-x (GdYBCO) coated conductor fabricated by MOCVD on an IBAD-MgO template. Additional rare-earth cations (Y and Gd) and Zr were incorporated into the superconducting film to form (Y,Gd) 2 O 3 and BaZrO 3 nanoparticles extended nearly parallel to the a-b planes and to the c-axis, respectively, to enhance the flux pinning. In-field measurement of J c was carried out with electrical current flowing either along or perpendicular to the longitudinal axis of the tape, while a maximum Lorentz force configuration was always maintained. Details in the angular dependence of J c were related to the unique structure of the film, specifically the tilt in the GdYBCO lattice and the tilts in the extended (Y,Gd) 2 O 3 and BaZrO3 nanoparticles. XRD and TEM were used to study the structure of the coated conductor. The effect of the misalignment between the external field H and the internal field B on the angular dependence of J c is discussed.

Lake-tilting investigations in southern Sweden

International Nuclear Information System (INIS)

Paasse, T.

1996-04-01

The main aim of lake-tilting investigations is to determine the course of the glacio-isostatic uplift, i.e. to find a formula for the uplift. Besides the lake-tilting graphs, knowledge of the recent relative uplift and the gradient of some marine shorelines are used for solving this problem. This paper summarizes four investigations. 23 refs, 10 figs

Acute Cutaneous Microvascular Flow Responses to Whole-Body Tilting in Humans

Science.gov (United States)

Breit, Gregory A.; Watenpaugh, Donald E.; Ballard, Richard E.; Hargens, Alan R.

1993-01-01

The transition from upright to head-down tilt (HDT) posture in humans increases blood pressure superior to the heart and decreases pressure inferior to the heart. Consequently, above heart level, myogenic arteriolar tone probably increases with HDT, in opposition to the withdrawal of baroreceptor-mediated sympathetic tone. We hypothesized that due to antagonism between central and local controls, the response of the facial cutaneous microcirculation to acute postural change will be weaker than that in the leg, where these two mechanisms reinforce each other. Cutaneous microvascular flow was measured by laser Doppler flowmetry simultaneously at the shin and the neck of 7 male and 3 female subjects. Subjects underwent a stepwise tilt protocol from standing control to 54 deg head-up tilt (HUT), 30 deg, 12 deg, O deg, -6 deg (HDT), -12 deg, -6 deg, O deg, 12 deg, 30 deg, 54 deg, and standing, for 30-sec periods with 10-sec transitions between postures. Flows at the shin and the neck increased significantly (P less than 0.05) from standing baseline to 12 deg HUT (252 +/- 55 and 126 +/- 9% (bar X +/- SE) of baseline, respectively). From 12 deg to -12 deg tilt, flows continued to increase at the shin (509 +/- 71% of baseline) but decreased at the neck to baseline levels (100 +/- 15% of baseline). Cutaneous microvascular flow recovered at both sites during the return to standing posture with significant hysteresis. Flow increases from standing to near-supine posture are attributed at both sites to baroreceptor-mediated vasodilation. The great dissimilarity in flow response magnitudes at the two measurement sites may be indicative of central/local regulatory antagonism above heart level and reinforcement below heart level.

Growth of large size lithium niobate single crystals of high quality by tilting-mirror-type floating zone method

Energy Technology Data Exchange (ETDEWEB)

Sarker, Abdur Razzaque, E-mail: razzaque_ru2000@yahoo.com [Department of Physics, University of Rajshahi (Bangladesh)

2016-05-15

Large size high quality LiNbO{sub 3} single crystals were grown successfully by tilting-mirror-type floating zone (TMFZ) technique. The grown crystals were characterized by X-ray diffraction, etch pits density measurement, Impedance analysis, Vibrating sample magnetometry (VSM) and UV-Visible spectrometry. The effect of mirror tilting during growth on the structural, electrical, optical properties and defect density of the LiNbO{sub 3} crystals were investigated. It was found that the defect density in the crystals reduced for tilting the mirror in the TMFZ method. The chemical analysis revealed that the grown crystals were of high quality with uniform composition. The single crystals grown by TMFZ method contains no low-angle grain boundaries, indicating that they can be used for high efficiency optoelectronic devices. (author)

Study of a Car Body Tilting System Using a Variable Link Mechanism: Fundamental Characteristics of Pendulum Motion and Strategy for Perfect Tilting

Science.gov (United States)

Yoshida, Hidehisa; Nagai, Masao

This paper analyzes the fundamental dynamic characteristics of a tilting railway vehicle using a variable link mechanism for compensating both the lateral acceleration experienced by passengers and the wheel load imbalance between the inner and outer rails. The geometric relations between the center of rotation, the center of gravity, and the positions of all four links of the tilting system are analyzed. Then, equations of the pendulum motions of the railway vehicle body with a four-link mechanism are derived. A theoretically discussion is given on the geometrical shapes employed in the link mechanism that can simultaneously provide zero lateral acceleration and zero wheel load fluctuation. Then, the perfect tilting condition, which is the control target of the feedforward tilting control, is derived from the linear equation of tilting motion.

Source to Accretion Disk Tilt

OpenAIRE

Montgomery, M. M.; Martin, E. L.

2010-01-01

Many different system types retrogradely precess, and retrograde precession could be from a tidal torque by the secondary on a misaligned accretion disk. However, a source to cause and maintain disk tilt is unknown. In this work, we show that accretion disks can tilt due to a force called lift. Lift results from differing gas stream supersonic speeds over and under an accretion disk. Because lift acts at the disk's center of pressure, a torque is applied around a rotation axis passing through...

Optimal tilt-angles for solar collectors used in China

International Nuclear Information System (INIS)

Tang Runsheng; Wu Tong

2004-01-01

A reasonable estimation of the optimal tilt angle of a fixed collector for maximizing its energy collection must be done based on the monthly global and diffuse radiation on a horizontal surface. However, the monthly diffuse radiation is not always available in many places. In this paper, a simple mathematical procedure for the estimation of the optimal tilt angle of a collector is presented based on the monthly horizontal radiation. A comparison of the optimal tilt angles of collectors obtained from expected monthly diffuse radiation and that from the actual monthly diffuse radiation showed that this method gives a good estimation of the optimal tilt angle, except for places with a considerably lower clearness index. A contour map of the optimal tilt angle of the south-facing collectors used for the entire year in China is also outlined, based on monthly horizontal radiation of 152 places around the country, combing the optimal tilt angle of another 30 cities based on the actual monthly diffuse radiation

LONG-TERM MEASUREMENTS OF SUNSPOT MAGNETIC TILT ANGLES

Energy Technology Data Exchange (ETDEWEB)

Li Jing [Department of Earth and Space Sciences, University of California at Los Angeles, Los Angeles, CA 90095-1567 (United States); Ulrich, Roger K., E-mail: jli@igpp.ucla.edu [Department of Physics and Astronomy, University of California at Los Angeles, Los Angeles, CA 90095-1567 (United States)

2012-10-20

Tilt angles of close to 30,600 sunspots are determined using Mount Wilson daily averaged magnetograms taken from 1974 to 2012, and SOHO/MDI magnetograms taken from 1996 to 2010. Within a cycle, more than 90% of sunspots have a normal polarity alignment along the east-west direction following Hale's law. The median tilts increase with increasing latitude (Joy's law) at a rate of {approx}0.{sup 0}5 per degree of latitude. Tilt angles of spots appear largely invariant with respect to time at a given latitude, but they decrease by {approx}0.{sup 0}9 per year on average, a trend that largely reflects Joy's law following the butterfly diagram. We find an asymmetry between the hemispheres in the mean tilt angles. On average, the tilts are greater in the Southern than in the Northern Hemisphere for all latitude zones, and the differences increase with increasing latitude.

Impact of Dietary, Socioeconomic, and Physical Factors on Obese and Overweight Schoolchildren Living in Sidi-Bel-Abbes (West of Algeria and Ain Defla (Centre

Directory of Open Access Journals (Sweden)

Didaoui Hayat

2018-03-01

Full Text Available Background and aims: The aim of the current study was to assess the impact of environmental factors; food, socio-economic, and physical activity, on a group of obese children living in Ain-Defla (Center Algeria and Sidi-Bel-Abbes (West Algeria.

Efficacy of tilt training in patients with vasovagal syncope.

Science.gov (United States)

Gajek, Jacek; Zyśko, Dorota; Mazurek, Walentyna

2006-06-01

Besides pharmacological therapy and pacemaker implantation, tilt training is a promising method of treatment in patients with vasovagal syncope (VVS). Tilt training is usually offered to patients with malignant or recurrent VVS which impairs their quality of life and carries a risk of injury. To assess the efficacy of tilt training in patients with VVS. The study group consisted of 40 patients (29 females, 11 males, aged 36.6+/-14 years, range 18-57 years) who underwent tilt training using tilt table testing according to the Westminster protocol. The mean number of syncopal episodes prior to the initiation of tilt training was 6.5+/-4.9 (range 0-20); 3 patients had a history of very frequent faints. According to the VASIS classification, type I VVS (mixed) was diagnosed in 17 patients, type II (cardioinhibitory) in 22 subjects, and type III (vasodepressive) in one patient. Mean follow-up duration was 35.1+/-13.5 months. The control group, which did not undergo the tilt testing programme, consisted of 29 patients with VVS (25 females, 4 males, mean age 44.2+/-15.0 years) who had a mean of 3.3+/-3.2 (range 0-12) syncopal episodes in the past (p <0.05 vs study group); 6 of these patients had only pre-syncopal episodes. Type I VVS was diagnosed in 23 controls and type II VVS in 6 control subjects (syncope occurred during the passive phase of tilt testing in 7 subjects, whereas the remaining 22 fainted during NTG infusion). Of the patients from the study group, 3 underwent pacemaker implantation at the time of the initiation of tilt training. At the end of follow-up, 31 (77.5%) patients remained free from syncope recurrences, 5 had syncopal episodes during the initial phase of tilt training, whereas the remaining 4 continued to suffer from syncopal episodes. Out of 3 patients with presyncope, 2 had no syncope recurrences whereas 1 patient continued to have presyncopal attacks. Out of 3 patients with pacemakers, 1 reported activation of pacing in the interventional mode

Innovative Clean Coal Technology (ICCT): 180 MW demonstration of advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from coal-fired boilers. Topical report, LNCFS Levels 1 and 3 test results

Energy Technology Data Exchange (ETDEWEB)

1993-08-17

This report presents results from the third phase of an Innovative Clean Coal Technology (ICC-1) project demonstrating advanced tangentially-fired combustion techniques for the reduction of nitrogen oxide (NO{sub x}) emissions from a coal-fired boiler. The purpose of this project was to study the NO{sub x} emissions characteristics of ABB Combustion Engineering`s (ABB CE) Low NO{sub x} Concentric Firing System (LNCFS) Levels I, II, and III. These technologies were installed and tested in a stepwise fashion at Gulf Power Company`s Plant Lansing Smith Unit 2. The objective of this report is to provide the results from Phase III. During that phase, Levels I and III of the ABB C-E Services Low NO{sub x} Concentric Firing System were tested. The LNCFS Level III technology includes separated overfire air, close coupled overfire air, clustered coal nozzles, flame attachment coal nozzle tips, and concentric firing. The LNCFS Level I was simulated by closing the separated overfire air nozzles of the LNCFS Level III system. Based upon long-term data, LNCFS Level HI reduced NO{sub x} emissions by 45 percent at full load. LOI levels with LNCFS Level III increased slightly, however, tests showed that LOI levels with LNCFS Level III were highly dependent upon coal fineness. After correcting for leakage air through the separated overfire air system, the simulated LNCFS Level I reduced NO{sub x} emissions by 37 percent. There was no increase in LOI with LNCFS Level I.

Rotating Shaft Tilt Angle Measurement Using an Inclinometer

OpenAIRE

Luo Jun; Wang Zhiqian; Shen Chengwu; Wen Zhuoman; Liu Shaojin; Cai Sheng; Li Jianrong

2015-01-01

This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendic...

Magnetic configurations of the tilted current sheets in magnetotail

Directory of Open Access Journals (Sweden)

C. Shen

2008-11-01

Full Text Available In this research, the geometrical structures of tilted current sheet and tail flapping waves have been analysed based on multiple spacecraft measurements and some features of the tilted current sheets have been made clear for the first time. The geometrical features of the tilted current sheet revealed in this investigation are as follows: (1 The magnetic field lines (MFLs in the tilted current sheet are generally plane curves and the osculating planes in which the MFLs lie are about vertical to the equatorial plane, while the normal of the tilted current sheet leans severely to the dawn or dusk side. (2 The tilted current sheet may become very thin, the half thickness of its neutral sheet is generally much less than the minimum radius of the curvature of the MFLs. (3 In the neutral sheet, the field-aligned current density becomes very large and has a maximum value at the center of the current sheet. (4 In some cases, the current density is a bifurcated one, and the two humps of the current density often superpose two peaks in the gradient of magnetic strength, indicating that the magnetic gradient drift current is possibly responsible for the formation of the two humps of the current density in some tilted current sheets. Tilted current sheets often appear along with tail current sheet flapping waves. It is found that, in the tail flapping current sheets, the minimum curvature radius of the MFLs in the current sheet is rather large with values around 1 RE, while the neutral sheet may be very thin, with its half thickness being several tenths of RE. During the flapping waves, the current sheet is tilted substantially, and the maximum tilt angle is generally larger than 45°. The phase velocities of these flapping waves are several tens km/s, while their periods and wavelengths are several tens of minutes, and several earth radii, respectively. These tail flapping events generally last several hours and occur during quiet periods or periods of

Piping benchmark problems for the ABB/CE System 80+ Standardized Plant

International Nuclear Information System (INIS)

Bezler, P.; DeGrassi, G.; Braverman, J.; Wang, Y.K.

1994-07-01

To satisfy the need for verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for the ABB/Combustion Engineering System 80+ Standardized Plant, three benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the System 80+ standard design. It will be required that the combined license licensees demonstrate that their solution to these problems are in agreement with the benchmark problem set. The first System 80+ piping benchmark is a uniform support motion response spectrum solution for one section of the feedwater piping subjected to safe shutdown seismic loads. The second System 80+ piping benchmark is a time history solution for the feedwater piping subjected to the transient loading induced by a water hammer. The third System 80+ piping benchmark is a time history solution of the pressurizer surge line subjected to the accelerations induced by a main steam line pipe break. The System 80+ reactor is an advanced PWR type

Tibiotalar tilt - a new slant

Energy Technology Data Exchange (ETDEWEB)

Griffiths, H.; Wandtke, J.

1981-05-01

Classically tibiotalar tilt (TTT) is associated with four conditions: Fairbanks disease, hemophilia, sickle-cell anemia and juvenile rheumatoid arthritis. We have found it to be present in at least 20 other conditions including other dysplasias, developmental conditions such as fibrous dysplasia and a variety of other acquired disorders including various metabolic diseases and following previous trauma. The pathogenesis is controversial, but the most probable cause is related to stress and the blood supply of the distal tibial epiphysis. The differentiation of TTT from pseudotibiotalar tilt is also discussed.

Quantization of band tilting in modulated phononic crystals

Science.gov (United States)

Nassar, H.; Chen, H.; Norris, A. N.; Huang, G. L.

2018-01-01

A general theory of the tilting of dispersion bands in phononic crystals whose properties are being slowly and periodically modulated in space and time is established. The ratio of tilt to modulation speed is calculated, for the first time, in terms of Berry's phase and curvature and is proven to be a robust integer-valued Chern number. Derivations are based on a version of the adiabatic theorem for elastic waves demonstrated thanks to WKB asymptotics. Findings are exemplified in the case of a 3-periodic discrete spring-mass lattice. Tilted dispersion diagrams plotted using fully numerical simulations and semianalytical calculations based on a numerically gauge invariant expression of Berry's phase show perfect agreement. One-way blocking of waves due to the tilt, and ultimately to the breaking of reciprocity, is illustrated numerically and shown to be highly significant across a limited number of unit cells, suggesting the feasibility of experimental demonstrations. Finally, a version of the bulk-edge correspondence principle relating the tilt of bulk bands to the number of one-way gapless edge states is demonstrated.

Group theoretical analysis of octahedral tilting in perovskites

International Nuclear Information System (INIS)

Howard, C.J.; Stokes, H.T.

1998-01-01

Full text: Structures of the perovskite family, ABX 3 , have interested crystallographers over many years, and continue to attract attention on account of their fascinating electrical and magnetic properties, for example the giant magnetoresistive effects exhibited by certain perovskite materials. The ideal perovskite (cubic, space group Pm -/3 m) is a particularly simple structure, but also a demanding one, since aside from the lattice parameter there are no variable parameters in the structure. Consequently, the majority of perovskite structures are distorted perovskites (hettotypes), the most common distortion being the corner-linked tilting of the practically rigid BX 6 octahedral units. In this work, group theoretical methods have been applied to the study of octahedral tilting in perovskites. The only irreducible representations of the parent group (Pm -/3 m) which produce octahedral tilting subject to corner-linking constraints are M + / 3 and R 4 ' + . A six-dimensional order parameter in the reducible representation space of M + / 3 + R + / 4 describes the different possible tilting patterns. The space groups for the different perovskites are then simply the isotropy subgroups, comprising those operations which leave the order parameter invariant. The isotropy subgroups are obtained from a computer program or tabulations. The analysis yields a list of fifteen possible space groups for perovskites derived through octahedral tilting. A connection is made to the (twenty-three) tilt systems given previously by Glazer. The group-subgroup relationships have been derived and displayed. It is interesting to note that all known perovskites based on octahedral tilting conform with the fifteen space groups on our list, with the exception of one perovskite at high temperature, the structure of which seems poorly determined

Magnetic field orientation dependence of flux pinning in (Gd,Y)Ba2Cu3O7-x coated conductor with tilted lattice and nanostructures

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yifei [ORNL; Specht, Eliot D [ORNL; Cantoni, Claudia [ORNL; Christen, David K [ORNL; Zuev, Yuri L [ORNL; Goyal, Amit [ORNL; Sinclair, J. [University of Tennessee, Knoxville (UTK); Thompson, James R [ORNL; Aytug, Tolga [ORNL; Paranthaman, Mariappan Parans [ORNL; Chen, Y [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York

2009-01-01

The dependence of the critical current density (J{sub c}) on the orientation of an applied magnetic field was studied for a prototype (Gd,Y)Ba{sub 2}Cu{sub 3}O{sub 7?x} (GdYBCO) coated conductor fabricated by MOCVD on an IBAD-MgO template. Additional rare-earth cations (Y and Gd) and Zr were incorporated into the superconducting film to form (Y,Gd){sub 2}O{sub 3} and BaZrO{sub 3} nanoparticles extended nearly parallel to the a-b planes and to the c-axis, respectively, to enhance the flux pinning. In-field measurement of J{sub c} was carried out with electrical current flowing either along or perpendicular to the longitudinal axis of the tape, while a maximum Lorentz force configuration was always maintained. Details in the angular dependence of J{sub c} were related to the unique structure of the film, specifically the tilt in the GdYBCO lattice and the tilts in the extended (Y,Gd){sub 2}O{sub 3} and BaZrO{sub 3} nanoparticles. XRD and TEM were used to study the structure of the coated conductor. The effect of the misalignment between the external field H and the internal field B on the angular dependence of J{sub c} is discussed.

Monitoring of temperature-mediated phase transitions of adipose tissue by combined optical coherence tomography and Abbe refractometry.

Science.gov (United States)

Yanina, Irina Y; Popov, Alexey P; Bykov, Alexander V; Meglinski, Igor V; Tuchin, Valery V

2018-01-01

Observation of temperature-mediated phase transitions between lipid components of the adipose tissues has been performed by combined use of the Abbe refractometry and optical coherence tomography. The phase transitions of the lipid components were clearly observed in the range of temperatures from 24°C to 60°C, and assessed by quantitatively monitoring the changes of the refractive index of 1- to 2-mm-thick porcine fat tissue slices. The developed approach has a great potential as an alternative method for obtaining accurate information on the processes occurring during thermal lipolysis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

A new tilt on pelvic radiographs: a pilot study

Energy Technology Data Exchange (ETDEWEB)

Richards, P.J. [North Staffordshire Royal Infirmary, Department of Radiology, Stoke-on-Trent, Staffordshire (United Kingdom); Pattison, J.M. [University Hospital of North Staffordshire, Department of Radiology, Stoke on Trent (United Kingdom); Belcher, J. [Keele University, Department of Mathematics, Keele, Staffordshire (United Kingdom); DeCann, R.W. [IMECS, Department of Radiology, Market Drayton, Shropshire (United Kingdom); Anderson, Suzanne [University of Melbourne, Department of Radiology, Melbourne (Australia); Wynn-Jones, C. [University Hospital of North Staffordshire, Department of Orthopaedic Surgery, Stoke on Trent (United Kingdom)

2009-02-15

The aim of this study was to evaluate pelvic tilt on commonly performed measurements on radiography in primary protrusio acetabuli and developmental dysplasia of the hip. A dry assembled pelvis and spine skeleton was positioned in an isocentric skull unit and films exposed with increasing degrees of angulation of pelvic tilt. The films were then read by two independent readers for seven different measurements used to evaluate the hips and acetabular: acetabular line to ilioischial line, teardrop appearance, intercristal/intertuberous ratio, co-ordinates of femoral head, centre edge angle, acetabular depth/width ratio and acetabular angle. There was so much variation in the protrusio results that no formal recommendation of any standard radiographic test can be given. Only the inter tuberous distance is not effected by pelvic tilt. The acetabular angles for developmental dysplasia of the hip showed the most potential with pelvic tilt below 15 . As pelvic tilt increases, measurements used in protusio become unreliable, and computed tomography/magnetic resonance imaging are probably going to be more accurate as one can directly visualise pelvic intrusion. We recommend a lateral view to assess the degree of pelvic tilt in patients with protrusion to ensure these measurements are valid. (orig.)

Tilted hexagonal post arrays: DNA electrophoresis in anisotropic media.

Science.gov (United States)

Chen, Zhen; Dorfman, Kevin D

2014-02-01

Using Brownian dynamics simulations, we show that DNA electrophoresis in a hexagonal array of micron-sized posts changes qualitatively when the applied electric field vector is not coincident with the lattice vectors of the array. DNA electrophoresis in such "tilted" post arrays is superior to the standard "un-tilted" approach; while the time required to achieve a resolution of unity in a tilted post array is similar to an un-tilted array at a low-electric field strengths, this time (i) decreases exponentially with electric field strength in a tilted array and (ii) increases exponentially with electric field strength in an un-tilted array. Although the DNA dynamics in a post array are complicated, the electrophoretic mobility results indicate that the "free path," i.e. the average distance of ballistic trajectories of point-sized particles launched from random positions in the unit cell until they intersect the next post, is a useful proxy for the detailed DNA trajectories. The analysis of the free path reveals a fundamental connection between anisotropy of the medium and DNA transport therein that goes beyond simply improving the separation device. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Results of Toxicity Studies Conducted on Outfall X-08 and Its Contributing Waste Streams, November 1999 - June 2000

International Nuclear Information System (INIS)

Specht, W.L.

2000-01-01

This interim report summarizes the results of toxicity tests, Toxicity Identification Evaluations, and chemical analyses that have been conducted on SRS's NPDES Outfall X-08 and its contributing waste streams between November 1999 and June 2000

Gravito-Inertial Force Resolution in Perception of Synchronized Tilt and Translation

Science.gov (United States)

Wood, Scott J.; Holly, Jan; Zhang, Guen-Lu

2011-01-01

Natural movements in the sagittal plane involve pitch tilt relative to gravity combined with translation motion. The Gravito-Inertial Force (GIF) resolution hypothesis states that the resultant force on the body is perceptually resolved into tilt and translation consistently with the laws of physics. The purpose of this study was to test this hypothesis for human perception during combined tilt and translation motion. EXPERIMENTAL METHODS: Twelve subjects provided verbal reports during 0.3 Hz motion in the dark with 4 types of tilt and/or translation motion: 1) pitch tilt about an interaural axis at +/-10deg or +/-20deg, 2) fore-aft translation with acceleration equivalent to +/-10deg or +/-20deg, 3) combined "in phase" tilt and translation motion resulting in acceleration equivalent to +/-20deg, and 4) "out of phase" tilt and translation motion that maintained the resultant gravito-inertial force aligned with the longitudinal body axis. The amplitude of perceived pitch tilt and translation at the head were obtained during separate trials. MODELING METHODS: Three-dimensional mathematical modeling was performed to test the GIF-resolution hypothesis using a dynamical model. The model encoded GIF-resolution using the standard vector equation, and used an internal model of motion parameters, including gravity. Differential equations conveyed time-varying predictions. The six motion profiles were tested, resulting in predicted perceived amplitude of tilt and translation for each. RESULTS: The modeling results exhibited the same pattern as the experimental results. Most importantly, both modeling and experimental results showed greater perceived tilt during the "in phase" profile than the "out of phase" profile, and greater perceived tilt during combined "in phase" motion than during pure tilt of the same amplitude. However, the model did not predict as much perceived translation as reported by subjects during pure tilt. CONCLUSION: Human perception is consistent with

Optimum tilt angle and orientation for solar collectors in Syria

International Nuclear Information System (INIS)

Skeiker, Kamal

2009-01-01

One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle) for the solar collector in the main Syrian zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle) maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of approximately 30% more than the case of a solar collector fixed on a horizontal surface.

A Horizontal Tilt Correction Method for Ship License Numbers Recognition

Science.gov (United States)

Liu, Baolong; Zhang, Sanyuan; Hong, Zhenjie; Ye, Xiuzi

2018-02-01

An automatic ship license numbers (SLNs) recognition system plays a significant role in intelligent waterway transportation systems since it can be used to identify ships by recognizing the characters in SLNs. Tilt occurs frequently in many SLNs because the monitors and the ships usually have great vertical or horizontal angles, which decreases the accuracy and robustness of a SLNs recognition system significantly. In this paper, we present a horizontal tilt correction method for SLNs. For an input tilt SLN image, the proposed method accomplishes the correction task through three main steps. First, a MSER-based characters’ center-points computation algorithm is designed to compute the accurate center-points of the characters contained in the input SLN image. Second, a L 1- L 2 distance-based straight line is fitted to the computed center-points using M-estimator algorithm. The tilt angle is estimated at this stage. Finally, based on the computed tilt angle, an affine transformation rotation is conducted to rotate and to correct the input SLN horizontally. At last, the proposed method is tested on 200 tilt SLN images, the proposed method is proved to be effective with a tilt correction rate of 80.5%.

Rotating Shaft Tilt Angle Measurement Using an Inclinometer

Science.gov (United States)

Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Wen, Zhuoman; Liu, Shaojin; Cai, Sheng; Li, Jianrong

2015-10-01

This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

Rotating Shaft Tilt Angle Measurement Using an Inclinometer

Directory of Open Access Journals (Sweden)

Luo Jun

2015-10-01

Full Text Available This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

Large optics inspection, tilting, and washing stand

Science.gov (United States)

Ayers, Marion Jay [Brentwood, CA; Ayers, Shannon Lee [Brentwood, CA

2010-08-24

A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.

Tilting the jaw to improve the image quality or to reduce the dose in cone-beam computed tomography

International Nuclear Information System (INIS)

Luckow, Marlen; Deyhle, Hans; Beckmann, Felix; Dagassan-Berndt, Dorothea; Müller, Bert

2011-01-01

Objective: The image quality in cone-beam computed tomography (CBCT) should be improved tilting the mandible that contains two dental titanium implants, within the relevant range of motion. Materials and methods: Using the mandible of a five-month-old pig, CBCT was performed varying the accelerating voltage, beam current, the starting rotation angle of the mandible in the source-detector plane and the tilt angles of the jaw with respect to the source-detector plane. The different datasets were automatically registered with respect to micro CT data to extract the common volume and the deviance to the pre-defined standard that characterizes the image quality. Results: The variations of the accelerating voltage, beam current and the rotation within the source-detection plane provided the expected quantitative behavior indicating the appropriate choice of the imaging quality factor. The tilting of the porcine mandible by about 14° improves the image quality by almost a factor of two. Conclusions: The tilting of the mandible with two dental implants can be used to significantly reduce the artifacts of the strongly X-ray absorbing materials in the CBCT images. The comparison of 14° jaw tilting with respect to the currently recommended arrangement in plane with the teeth demonstrates that the applied exposure time and the related dose can be reduced by a factor of four without decreasing the image quality.

Diffracted X-ray tracking for monitoring intramolecular motion in individual protein molecules using broad band X-ray

Energy Technology Data Exchange (ETDEWEB)

Ichiyanagi, Kouhei; Sasaki, Yuji C. [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561 (Japan); Japan Science and Technology Agency, CREST, CREST, Sasaki-Team, 609 Kiban Building, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Sekiguchi, Hiroshi; Hoshino, Masato; Kajiwara, Kentaro; Senba, Yasunori; Ohashi, Haruhiko; Ohta, Noboru [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Hoshisashi, Kentaro; Jae-won, Chang; Tokue, Maki; Matsushita, Yufuku [Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 609 Kiban Building 5-1-5 Kashiwanoha, Kahiwashi, Chiba 277-8561 (Japan); Nishijima, Masaki; Inoue, Yoshihisa [Department of Applied Chemistry and Office for University-Industry Collaboration, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Yagi, Naoto [Japan Science and Technology Agency, CREST, CREST, Sasaki-Team, 609 Kiban Building, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2013-10-15

Diffracted X-ray tracking (DXT) enables the tilting and twisting motions of single protein molecules to be monitored with micro- to milliradian resolution using a highly brilliant X-ray source with a wide energy bandwidth. We have developed a technique to monitor single molecules using gold nanocrystals attached to individual protein molecules using the BL28B2 beamline at SPring-8. In this paper we present the installation of a single toroidal X-ray mirror at BL28B2 to focus X-rays in an energy range of 10–20 keV (△E/E = 82% for an X-ray with a wide energy bandwidth). With this beamline we tracked diffraction spots from gold nanocrystals over a wide angle range than that using quasi-monochromatic X-rays. Application of the wide angle DXT technique to biological systems enabled us to observe the on-site motions of single protein molecules that have been functionalized in vivo. We further extend the capability of DXT by observing the fractional tilting and twisting motions of inner proteins under various conditions. As a proof of this methodology and to determine instrumental performance the intramolecular motions of a human serum albumin complex with 2-anthracenecarboxylic acid was investigated using the BL28B2 beamline. The random tilting and twisting intramolecular motions are shown to be directly linked to the movement of individual protein molecules in the buffer solution.

RE-EXAMINING SUNSPOT TILT ANGLE TO INCLUDE ANTI-HALE STATISTICS

Energy Technology Data Exchange (ETDEWEB)

McClintock, B. H. [University of Southern Queensland, Toowoomba, 4350 (Australia); Norton, A. A. [HEPL, Stanford University, Palo Alto, CA 94305 (United States); Li, J., E-mail: u1049686@umail.usq.edu.au, E-mail: aanorton@stanford.edu, E-mail: jli@igpp.ucla.edu [Department of Earth, Planetary, and Space Sciences, University of California at Los Angeles, Los Angeles, CA 90095 (United States)

2014-12-20

Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data provided by Li and Ulrich that determined sunspot magnetic tilt angle using Mount Wilson magnetograms from 1974-2012. The magnetograms allowed for BMR tilt angles that were anti-Hale in configuration, so tilt values ranged from 0 to 360° rather than the more common ±90°. We explore the visual representation of magnetic tilt angles on a traditional butterfly diagram by plotting the mean area-weighted latitude of umbral activity in each bipolar sunspot group, including tilt information. The large scatter of tilt angles over the course of a single cycle and hemisphere prevents Joy's law from being visually identified in the tilt-butterfly diagram without further binning. The average latitude of anti-Hale regions does not differ from the average latitude of all regions in both hemispheres. The distribution of anti-Hale sunspot tilt angles are broadly distributed between 0 and 360° with a weak preference for east-west alignment 180° from their expected Joy's law angle. The anti-Hale sunspots display a log-normal size distribution similar to that of all sunspots, indicating no preferred size for anti-Hale sunspots. We report that 8.4% ± 0.8% of all bipolar sunspot regions are misclassified as Hale in traditional catalogs. This percentage is slightly higher for groups within 5° of the equator due to the misalignment of the magnetic and heliographic equators.

RE-EXAMINING SUNSPOT TILT ANGLE TO INCLUDE ANTI-HALE STATISTICS

International Nuclear Information System (INIS)

McClintock, B. H.; Norton, A. A.; Li, J.

2014-01-01

Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data provided by Li and Ulrich that determined sunspot magnetic tilt angle using Mount Wilson magnetograms from 1974-2012. The magnetograms allowed for BMR tilt angles that were anti-Hale in configuration, so tilt values ranged from 0 to 360° rather than the more common ±90°. We explore the visual representation of magnetic tilt angles on a traditional butterfly diagram by plotting the mean area-weighted latitude of umbral activity in each bipolar sunspot group, including tilt information. The large scatter of tilt angles over the course of a single cycle and hemisphere prevents Joy's law from being visually identified in the tilt-butterfly diagram without further binning. The average latitude of anti-Hale regions does not differ from the average latitude of all regions in both hemispheres. The distribution of anti-Hale sunspot tilt angles are broadly distributed between 0 and 360° with a weak preference for east-west alignment 180° from their expected Joy's law angle. The anti-Hale sunspots display a log-normal size distribution similar to that of all sunspots, indicating no preferred size for anti-Hale sunspots. We report that 8.4% ± 0.8% of all bipolar sunspot regions are misclassified as Hale in traditional catalogs. This percentage is slightly higher for groups within 5° of the equator due to the misalignment of the magnetic and heliographic equators

LOTTTTUCE: Layer Oriented Tip-Tilt Turbulence Tomography using Covariance and Elevation

International Nuclear Information System (INIS)

Lai, Olivier; Hayano, Yutaka; Oya, Shin; Chun, Mark; Lu, Jessica R; Toomey, Douglas

2015-01-01

LOTTTTUCE is based upon the fact that turbulence at the pupil produces correlated tip-tilt motion over the entire field (averaging the tip-tilt across the widest field possible gives the strength of the turbulence at the telescope), while the on-axis (any axis) image motion measures the integrated tip-tilt over the line of sight (single stars provide the variance of the tip-tilt, which allows to infer the integrated seeing). Between these two extremes, the amount of correlation across a given field size is the integral of the turbulence from the ground to the altitude where the tip-tilt decorrelates over the meta-pupil. Differentiating the altitude- integrated tip-tilt with respect to altitude generates an estimate of tip-tilt (hence turbulence, assuming Kolmogorov properties) at each altitude. Alternately, the 3D Fourier transform of a data cube containing the time evolution of the tip (or tilt) across the field allows to determine the amount of energy for “field” frequencies (in other words, the integrated seeing across each same size patches) and the temporal spectrum of each of these features. Differentiating the spectrum with respect to spatial frequency would provide the amount of energy, as well as speed and direction, of each layer. The LOTTTTUCE method is a novel method of measuring the vertical turbulence profile that uses wide field tip-tilt information such as that provided by Pan-STARRS. However, the method also has limitations due to tip-tilt decorrelation as a function of meta-pupil overlap, finite outer scale, and non-Kolmogorov power spectrum. (paper)

Generating picosecond x-ray pulses in synchrotron light sources using dipole kickers

Directory of Open Access Journals (Sweden)

W. Guo

2007-02-01

Full Text Available The duration of the x-ray pulse generated at a synchrotron light source is typically tens of picoseconds. Shorter pulses are highly desired by the users. In electron storage rings, the vertical beam size is usually orders of magnitude less than the bunch length due to radiation damping; therefore, a shorter pulse can be obtained by slitting the vertically tilted bunch. Zholents proposed tilting the bunch using rf deflection. We found that tilted bunches can also be generated by a dipole magnet kick. A vertical tilt is developed after the kick in the presence of nonzero chromaticity. The tilt was successfully observed and a 4.2-ps pulse was obtained from a 27-ps electron bunch at the Advanced Photon Source. Based on this principle, we propose a short-pulse generation scheme that produces picosecond x-ray pulses at a repetition rate of 1–2 kHz, which can be used for pump-probe experiments.

Age, splanchnic vasoconstriction, and heat stress during tilting

Science.gov (United States)

Minson, C. T.; Wladkowski, S. L.; Pawelczyk, J. A.; Kenney, W. L.

1999-01-01

During upright tilting, blood is translocated to the dependent veins of the legs and compensatory circulatory adjustments are necessary to maintain arterial pressure. For examination of the effect of age on these responses, seven young (23 +/- 1 yr) and seven older (70 +/- 3 yr) men were head-up tilted to 60 degrees in a thermoneutral condition and during passive heating with water-perfused suits. Measurements included heart rate (HR), cardiac output (Qc; acetylene rebreathing technique), central venous pressure (CVP), blood pressures, forearm blood flow (venous occlusion plethysmography), splanchnic and renal blood flows (indocyanine green and p-aminohippurate clearance), and esophageal and mean skin temperatures. In response to tilting in the thermoneutral condition, CVP and stroke volume decreased to a greater extent in the young men, but HR increased more, such that the fall in Qc was similar between the two groups in the upright posture. The rise in splanchnic vascular resistance (SVR) was greater in the older men, but the young men increased forearm vascular resistance (FVR) to a greater extent than the older men. The fall in Qc during combined heat stress and tilting was greater in the young compared with older men. Only four of the young men versus six of the older men were able to finish the second tilt without becoming presyncopal. In summary, the older men relied on a greater increase in SVR to compensate for a reduced ability to constrict the skin and muscle circulations (as determined by changes in FVR) during head-up tilting.

Study of coherent diffractive production reactions of p + C --> [Y$^{0}$K$^{+}$] + C type and observation of the new baryonic states X(2050) --> $\\Sigma$(1385)$^{0}$K$^{+}$ and X(2000) --> $\\Sigma^{0}$K$^{+}$

CERN Document Server

Golovkin, S V; Kozhevnikov, A A; Kubarovskii, V P; Kulyavtsev, A I; Kurshetsov, V F; Kushnirenko, A Yu; Landsberg, G L; Molchanov, V V; Mukkin, V A; Solyanik, V I; Vavilov, D V; Victorov, V A; Balats, M Ya; Dzubenko, G B; Kamenskii, A D; Kliger, G K; Kolganov, V Z; Lakaev, V S; Lomkatsi, G S; Nilov, A P; Smolyankin, V T; Vishniakov, V V

1994-01-01

Study of coherent diffractive production reactions of p + C --> [Y$^{0}$K$^{+}$] + C type and observation of the new baryonic states X(2050) --> $\\Sigma$(1385)$^{0}$K$^{+}$ and X(2000) --> $\\Sigma^{0}$K$^{+}$

Comparison of different grading schemes in InGaAs metamorphic buffers on GaAs substrate: Tilt dependence on cross-hatch irregularities

International Nuclear Information System (INIS)

Kumar, Rahul; Bag, Ankush; Mukhopadhyay, Partha; Das, Subhashis; Biswas, Dhrubes

2015-01-01

Highlights: • InGaAs graded MBs with different grading scheme has been grown by MBE on GaAs. • Continuously graded MB exhibits smoother surface morphology. • Grading scheme has been found to have little impact on lattice relaxation. • Grading schemeaffects the lattice tilt significantly. • Cross-hatch surface irregularities affect the crystallographic tilt. - Abstract: InGaAs graded metamorphic buffers (MBs) with different grading strategies have been grown by molecular beam epitaxy (MBE) on GaAs (0 0 1) substrate. A detailed comparative analysis of surface using atomic force microscopy (AFM), and bulk properties using high resolution X-ray diffraction (HRXRD) and room temperature photoluminescence (RTPL) of grown MBs have been presented to comprehend the effectiveness of different grading scheme on InGaAs MBs. Conventional, statistical and fractal analysis on measured AFM data has been performed for in-depth investigation of these surfaces. The grading scheme has been found to have little impact on residual strain while it affects the epitaxial tilt significantly. Moreover, the tilt has been found to depend on growth front irregularities. Tilt magnitude in a graded MB has been found to vary with composition while tilt azimuth has been found to be almost same in the graded layers. PL Intensity and a shift in the PL peaks have been used to study the quality of the MB and residual strain comparatively.

Comparison of different grading schemes in InGaAs metamorphic buffers on GaAs substrate: Tilt dependence on cross-hatch irregularities

Energy Technology Data Exchange (ETDEWEB)

Kumar, Rahul, E-mail: rkp203@gmail.com [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Bag, Ankush [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Mukhopadhyay, Partha [Rajendra Mishra School of Engineering Entrepreneurship, Indian Institute of Technology, Kharagpur 721302 (India); Das, Subhashis [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Biswas, Dhrubes [Department of Electronics & Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721 302 (India)

2015-12-01

Highlights: • InGaAs graded MBs with different grading scheme has been grown by MBE on GaAs. • Continuously graded MB exhibits smoother surface morphology. • Grading scheme has been found to have little impact on lattice relaxation. • Grading schemeaffects the lattice tilt significantly. • Cross-hatch surface irregularities affect the crystallographic tilt. - Abstract: InGaAs graded metamorphic buffers (MBs) with different grading strategies have been grown by molecular beam epitaxy (MBE) on GaAs (0 0 1) substrate. A detailed comparative analysis of surface using atomic force microscopy (AFM), and bulk properties using high resolution X-ray diffraction (HRXRD) and room temperature photoluminescence (RTPL) of grown MBs have been presented to comprehend the effectiveness of different grading scheme on InGaAs MBs. Conventional, statistical and fractal analysis on measured AFM data has been performed for in-depth investigation of these surfaces. The grading scheme has been found to have little impact on residual strain while it affects the epitaxial tilt significantly. Moreover, the tilt has been found to depend on growth front irregularities. Tilt magnitude in a graded MB has been found to vary with composition while tilt azimuth has been found to be almost same in the graded layers. PL Intensity and a shift in the PL peaks have been used to study the quality of the MB and residual strain comparatively.

TNX/HLW Long Shaft Pumps 1995-2000

International Nuclear Information System (INIS)

VanPelt, B.

2002-01-01

Problems with long shaft pumps are becoming clearer due to increased use, better instrumentation, more analysis, and increased testing activity. The problems are with reliability and not with hydraulic performance. The root cause of reliability problems is usually excessive vibration caused by design. The outlook for satisfactory pumps is improved as understanding of problems increases. Promising developments are emerging such as the tilt pad bearing. Alternative configurations, such as gas filled columns and submerged motor pumps, will require development. Continued development, in general, should be expected due to changing technology and industry changes. This report describes thirteen distinct pump programs starting with leakage of original mixer pumps in the 1980s and ending with the testing of tilt pad bearings now in progress. Eight of the programs occurred from 1996 to 2000. All involve long shaft pumps; all involve testing at TNX; and all involve a problem of some kind. The co mmon technical issue among the activities is vibration and shaft (or rotor) instability due to journal bearings. In every case, excessive shaft vibration is a reasonable and probable explanation for some or all of the problems

Correlation between length and tilt of lipid tails

Science.gov (United States)

Kopelevich, Dmitry I.; Nagle, John F.

2015-10-01

It is becoming recognized from simulations, and to a lesser extent from experiment, that the classical Helfrich-Canham membrane continuum mechanics model can be fruitfully enriched by the inclusion of molecular tilt, even in the fluid, chain disordered, biologically relevant phase of lipid bilayers. Enriched continuum theories then add a tilt modulus κθ to accompany the well recognized bending modulus κ. Different enrichment theories largely agree for many properties, but it has been noticed that there is considerable disagreement in one prediction; one theory postulates that the average length of the hydrocarbon chain tails increases strongly with increasing tilt and another predicts no increase. Our analysis of an all-atom simulation favors the latter theory, but it also shows that the overall tail length decreases slightly with increasing tilt. We show that this deviation from continuum theory can be reconciled by consideration of the average shape of the tails, which is a descriptor not obviously includable in continuum theory.

Correlation between length and tilt of lipid tails

Energy Technology Data Exchange (ETDEWEB)

Kopelevich, Dmitry I., E-mail: dkopelevich@che.ufl.edu [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Nagle, John F., E-mail: nagle@cmu.edu [Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

2015-10-21

It is becoming recognized from simulations, and to a lesser extent from experiment, that the classical Helfrich-Canham membrane continuum mechanics model can be fruitfully enriched by the inclusion of molecular tilt, even in the fluid, chain disordered, biologically relevant phase of lipid bilayers. Enriched continuum theories then add a tilt modulus κ{sub θ} to accompany the well recognized bending modulus κ. Different enrichment theories largely agree for many properties, but it has been noticed that there is considerable disagreement in one prediction; one theory postulates that the average length of the hydrocarbon chain tails increases strongly with increasing tilt and another predicts no increase. Our analysis of an all-atom simulation favors the latter theory, but it also shows that the overall tail length decreases slightly with increasing tilt. We show that this deviation from continuum theory can be reconciled by consideration of the average shape of the tails, which is a descriptor not obviously includable in continuum theory.

Skin cooling maintains cerebral blood flow velocity and orthostatic tolerance during tilting in heated humans

Science.gov (United States)

Wilson, Thad E.; Cui, Jian; Zhang, Rong; Witkowski, Sarah; Crandall, Craig G.

2002-01-01

Orthostatic tolerance is reduced in the heat-stressed human. The purpose of this project was to identify whether skin-surface cooling improves orthostatic tolerance. Nine subjects were exposed to 10 min of 60 degrees head-up tilting in each of four conditions: normothermia (NT-tilt), heat stress (HT-tilt), normothermia plus skin-surface cooling 1 min before and throughout tilting (NT-tilt(cool)), and heat stress plus skin-surface cooling 1 min before and throughout tilting (HT-tilt(cool)). Heating and cooling were accomplished by perfusing 46 and 15 degrees C water, respectively, though a tube-lined suit worn by each subject. During HT-tilt, four of nine subjects developed presyncopal symptoms resulting in the termination of the tilt test. In contrast, no subject experienced presyncopal symptoms during NT-tilt, NT-tilt(cool), or HT-tilt(cool). During the HT-tilt procedure, mean arterial blood pressure (MAP) and cerebral blood flow velocity (CBFV) decreased. However, during HT-tilt(cool), MAP, total peripheral resistance, and CBFV were significantly greater relative to HT-tilt (all P heat-stressed humans.

Radiographic cup anteversion measurement corrected from pelvic tilt.

Science.gov (United States)

Wang, Liao; Thoreson, Andrew R; Trousdale, Robert T; Morrey, Bernard F; Dai, Kerong; An, Kai-Nan

2017-11-01

The purpose of this study was to develop a novel technique to improve the accuracy of radiographic cup anteversion measurement by correcting the influence of pelvic tilt. Ninety virtual total hip arthroplasties were simulated from computed tomography data of 6 patients with 15 predetermined cup orientations. For each simulated implantation, anteroposterior (AP) virtual pelvic radiographs were generated for 11 predetermined pelvic tilts. A linear regression model was created to capture the relationship between radiographic cup anteversion angle error measured on AP pelvic radiographs and pelvic tilt. Overall, nine hundred and ninety virtual AP pelvic radiographs were measured, and 90 linear regression models were created. Pearson's correlation analyses confirmed a strong correlation between the errors of conventional radiographic cup anteversion angle measured on AP pelvic radiographs and the magnitude of pelvic tilt (P cup anteversion angle from the influence of pelvic tilt. The current method proposes to measure the pelvic tilt on a lateral radiograph, and to use it as a correction for the radiographic cup anteversion measurement on an AP pelvic radiograph. Thus, both AP and lateral pelvic radiographs are required for the measurement of pelvic posture-integrated cup anteversion. Compared with conventional radiographic cup anteversion, the errors of pelvic posture-integrated radiographic cup anteversion were reduced from 10.03 (SD = 5.13) degrees to 2.53 (SD = 1.33) degrees. Pelvic posture-integrated cup anteversion measurement improves the accuracy of radiographic cup anteversion measurement, which shows the potential of further clarifying the etiology of postoperative instability based on planar radiographs. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Tilted dipole model for bias-dependent photoluminescence pattern

Energy Technology Data Exchange (ETDEWEB)

Fujieda, Ichiro, E-mail: fujieda@se.ritsumei.ac.jp; Suzuki, Daisuke; Masuda, Taishi [Department of Electrical and Electronic Engineering, Ritsumeikan University, Kusatsu 525-8577 (Japan)

2014-12-14

In a guest-host system containing elongated dyes and a nematic liquid crystal, both molecules are aligned to each other. An external bias tilts these molecules and the radiation pattern of the system is altered. A model is proposed to describe this bias-dependent photoluminescence patterns. It divides the liquid crystal/dye layer into sub-layers that contain electric dipoles with specific tilt angles. Each sub-layer emits linearly polarized light. Its radiation pattern is toroidal and is determined by the tilt angle. Its intensity is assumed to be proportional to the power of excitation light absorbed by the sub-layer. This is calculated by the Lambert-Beer's Law. The absorption coefficient is assumed to be proportional to the cross-section of the tilted dipole moment, in analogy to the ellipsoid of refractive index, to evaluate the cross-section for each polarized component of the excitation light. Contributions from all the sub-layers are added to give a final expression for the radiation pattern. Self-absorption is neglected. The model is simplified by reducing the number of sub-layers. Analytical expressions are derived for a simple case that consists of a single layer with tilted dipoles sandwiched by two layers with horizontally-aligned dipoles. All the parameters except for the tilt angle can be determined by measuring transmittance of the excitation light. The model roughly reproduces the bias-dependent photoluminescence patterns of a cell containing 0.5 wt. % coumarin 6. It breaks down at large emission angles. Measured spectral changes suggest that the discrepancy is due to self-absorption and re-emission.

Does osteoporosis reduce the primary tilting stability of cementless acetabular cups?

Science.gov (United States)

von Schulze Pellengahr, Christoph; von Engelhardt, Lars V; Wegener, Bernd; Müller, Peter E; Fottner, Andreas; Weber, Patrick; Ackermann, Ole; Lahner, Matthias; Teske, Wolfram

2015-04-21

Cementless hip cups need sufficient primary tilting stability to achieve osseointegration. The aim of the study was to assess differences of the primary implant stability in osteoporotic bone and in bone with normal bone density. To assess the influence of different cup designs, two types of threaded and two types of press-fit cups were tested. The maximum tilting moment for two different cementless threaded cups and two different cementless press-fit cups was determined in macerated human hip acetabuli with reduced (n=20) and normal bone density (n=20), determined using Q-CT. The tilting moments for each cup were determined five times in the group with reduced bone density and five times in the group with normal bone density, and the respective average values were calculated. The mean maximum extrusion force of the threaded cup Zintra was 5670.5 N (max. tilting moment 141.8 Nm) in bone with normal density and.5748.3 N (max. tilting moment 143.7 Nm) in osteoporotic bone. For the Hofer Imhof (HI) threaded cup it was 7681.5 N (192.0 Nm) in bone with normal density and 6828.9 N (max. tilting moment 170.7 Nm) in the group with osteoporotic bone. The mean maximum extrusion force of the macro-textured press-fit cup Metallsockel CL was 3824.6 N (max. tilting moment 95.6 Nm) in bone with normal and 2246.2 N (max. tilting moment 56.2 Nm) in osteoporotic bone. For the Monoblock it was 1303.8 N (max. tilting moment 32.6 Nm) in normal and 1317 N (max. tilting moment 32.9 Nm) in osteoporotic bone. There was no significance. A reduction of the maximum tilting moment in osteoporotic bone of the ESKA press-fit cup Metallsockel CL was noticed. Results on macerated bone specimens showed no statistically significant reduction of the maximum tilting moment in specimens with osteoporotic bone density compared to normal bone, neither for threaded nor for the press-fit cups. With the limitation that the results were obtained using macerated bone, we could not detect any restrictions for

Position, Attitude, and Fault-Tolerant Control of Tilting-Rotor Quadcopter

Science.gov (United States)

Kumar, Rumit

The aim of this thesis is to present algorithms for autonomous control of tilt-rotor quadcopter UAV. In particular, this research work describes position, attitude and fault tolerant control in tilt-rotor quadcopter. Quadcopters are one of the most popular and reliable unmanned aerial systems because of the design simplicity, hovering capabilities and minimal operational cost. Numerous applications for quadcopters have been explored all over the world but very little work has been done to explore design enhancements and address the fault-tolerant capabilities of the quadcopters. The tilting rotor quadcopter is a structural advancement of traditional quadcopter and it provides additional actuated controls as the propeller motors are actuated for tilt which can be utilized to improve efficiency of the aerial vehicle during flight. The tilting rotor quadcopter design is accomplished by using an additional servo motor for each rotor that enables the rotor to tilt about the axis of the quadcopter arm. Tilting rotor quadcopter is a more agile version of conventional quadcopter and it is a fully actuated system. The tilt-rotor quadcopter is capable of following complex trajectories with ease. The control strategy in this work is to use the propeller tilts for position and orientation control during autonomous flight of the quadcopter. In conventional quadcopters, two propellers rotate in clockwise direction and other two propellers rotate in counter clockwise direction to cancel out the effective yawing moment of the system. The variation in rotational speeds of these four propellers is utilized for maneuvering. On the other hand, this work incorporates use of varying propeller rotational speeds along with tilting of the propellers for maneuvering during flight. The rotational motion of propellers work in sync with propeller tilts to control the position and orientation of the UAV during the flight. A PD flight controller is developed to achieve various modes of the

Sedimentary basins reconnaissance using the magnetic Tilt-Depth method

Science.gov (United States)

Salem, A.; Williams, S.; Samson, E.; Fairhead, D.; Ravat, D.; Blakely, R.J.

2010-01-01

We compute the depth to the top of magnetic basement using the Tilt-Depth method from the best available magnetic anomaly grids covering the continental USA and Australia. For the USA, the Tilt-Depth estimates were compared with sediment thicknesses based on drilling data and show a correlation of 0.86 between the datasets. If random data were used then the correlation value goes to virtually zero. There is little to no lateral offset of the depth of basinal features although there is a tendency for the Tilt-Depth results to be slightly shallower than the drill depths. We also applied the Tilt-Depth method to a local-scale, relatively high-resolution aeromagnetic survey over the Olympic Peninsula of Washington State. The Tilt-Depth method successfully identified a variety of important tectonic elements known from geological mapping. Of particular interest, the Tilt-Depth method illuminated deep (3km) contacts within the non-magnetic sedimentary core of the Olympic Mountains, where magnetic anomalies are subdued and low in amplitude. For Australia, the Tilt-Depth estimates also give a good correlation with known areas of shallow basement and sedimentary basins. Our estimates of basement depth are not restricted to regional analysis but work equally well at the micro scale (basin scale) with depth estimates agreeing well with drill hole and seismic data. We focus on the eastern Officer Basin as an example of basin scale studies and find a good level of agreement between previously-derived basin models. However, our study potentially reveals depocentres not previously mapped due to the sparse distribution of well data. This example thus shows the potential additional advantage of the method in geological interpretation. The success of this study suggests that the Tilt-Depth method is useful in estimating the depth to crystalline basement when appropriate quality aeromagnetic anomaly data are used (i.e. line spacing on the order of or less than the expected depth to

Tilted Lemaitre-Tolman-Bondi spacetimes: Hydrodynamic and thermodynamic properties

International Nuclear Information System (INIS)

Herrera, L.; Di Prisco, A.; Ibanez, J.

2011-01-01

We consider Lemaitre-Tolman-Bondi spacetimes from the point of view of a tilted observer, i.e. one with respect to which the fluid is radially moving. The imperfect fluid and the congruence described by its four-velocity, as seen by the tilted observer, is studied in detail. It is shown that from the point of view of such tilted observer, the fluid evolves nonreversibly (i.e. with nonvanishing rate of entropy production). The nongeodesic character of the tilted congruence is related to the nonvanishing of the divergence of the 4-vector entropy flow. We determine the factor related to the existence of energy-density inhomogeneities and describe its evolution; these results are compared with those obtained for the nontilted observer. Finally, we exhibit a peculiar situation where the nontilted congruence might be unstable.

A tip / tilt mirror with large dynamic range for the ESO VLT Four Laser Guide Star Facility

NARCIS (Netherlands)

Rijnveld, N.; Henselmans, R.; Nijland, B.A.H.

2011-01-01

One of the critical elements in the Four Laser Guide Star Facility (4LGSF) for the ESO Very Large Telescope (VLT) is the Optical Tube Assembly (OTA), consisting of a stable 20x laser beam expander and an active tip/tilt mirror, the Field Selector Mechanism (FSM). This paper describes the design and

How do visual and postural cues combine for self-tilt perception during slow pitch rotations?

Science.gov (United States)

Scotto Di Cesare, C; Buloup, F; Mestre, D R; Bringoux, L

2014-11-01

Self-orientation perception relies on the integration of multiple sensory inputs which convey spatially-related visual and postural cues. In the present study, an experimental set-up was used to tilt the body and/or the visual scene to investigate how these postural and visual cues are integrated for self-tilt perception (the subjective sensation of being tilted). Participants were required to repeatedly rate a confidence level for self-tilt perception during slow (0.05°·s(-1)) body and/or visual scene pitch tilts up to 19° relative to vertical. Concurrently, subjects also had to perform arm reaching movements toward a body-fixed target at certain specific angles of tilt. While performance of a concurrent motor task did not influence the main perceptual task, self-tilt detection did vary according to the visuo-postural stimuli. Slow forward or backward tilts of the visual scene alone did not induce a marked sensation of self-tilt contrary to actual body tilt. However, combined body and visual scene tilt influenced self-tilt perception more strongly, although this effect was dependent on the direction of visual scene tilt: only a forward visual scene tilt combined with a forward body tilt facilitated self-tilt detection. In such a case, visual scene tilt did not seem to induce vection but rather may have produced a deviation of the perceived orientation of the longitudinal body axis in the forward direction, which may have lowered the self-tilt detection threshold during actual forward body tilt. Copyright © 2014 Elsevier B.V. All rights reserved.

Tilted-ring modelling of disk galaxies : Anomalous gas

NARCIS (Netherlands)

Jozsa, G. I. G.; Niemczyk, C.; Klein, U.; Oosterloo, T. A.

We report our ongoing work on kinematical modelling of HI in disk galaxies. We employ our new software TiRiFiC (Tilted-Ring-Fitting-Code) in order to derive tilted-ring models by fitting artificial HI data cubes to observed ones in an automated process. With this technique we derive very reliable

Morphology, structure, and electrical properties of YBa{sub 2}Cu{sub 3}O{sub x} thin films on tilted NdGaO{sub 3} substrates, deposited by DC-sputtering

Energy Technology Data Exchange (ETDEWEB)

Mozhaev, Peter B. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation)]. E-mail: pbmozh@nm.ru; Kotelyanskii, Iosif M. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation); Luzanov, Valery A. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation); Mozhaeva, Julia E. [Institute of Radio Engineering and Electronics RAS, Moscow 125009 (Russian Federation); Donchev, Todor [Institute of Electronics BAS, Sofia (Bulgaria); Mateev, Emil [Institute of Electronics BAS, Sofia (Bulgaria); Nurgaliev, Timur [Institute of Electronics BAS, Sofia (Bulgaria); Bdikin, Igor K. [Institute of Solid State Physics RAS, Chernogolovka, Moscow 142432 (Russian Federation); Department of Ceramic and Glass Engineering, CICECO, University of Aveiro, Aveiro 3810-193 (Portugal); Narymbetov, Bakhyt Zh. [Complex Institute of Natural Sciences UzAS, Nukus (Uzbekistan)

2005-02-15

Thin YBa{sub 2}Cu{sub 3}O{sub x} (YBCO) films were deposited using DC-sputtering technique on NdGaO{sub 3} substrates, tilted from (1 1 0) orientation by 0-26 deg . The structure and surface quality of the substrates were carefully characterized to obtain reliable results of thin films deposition. Structural, morphological and electrical properties of the YBCO thin films show three different ranges of inclination angle: vicinal, intermediate and high. In the vicinal range the properties of the film are generally the same as of the standard films deposited on (1 1 0) NdGaO{sub 3} substrate. An increase of the inclination angle to the intermediate range results in a significant improvement of morphology and structural quality of the film. Best electrical parameters are measured for the films of the intermediate range also. Probable reason for such behavior is simultaneous and regular seeding of the film in the joints of facets on the substrate surface. Further increase of inclination angle leads to step bunching and oxygen out-diffusion, destroying both structural and electrical perfection of the tilted-axes YBCO film.

Exploiting Phase Diversity for CDMA2000 1X Smart Antenna Base Stations

Science.gov (United States)

Kim, Seongdo; Hyeon, Seungheon; Choi, Seungwon

2004-12-01

A performance analysis of an access channel decoder is presented which exploits a diversity gain due to the independent magnitude of received signals energy at each of the antenna elements of a smart-antenna base-station transceiver subsystem (BTS) operating in CDMA2000 1X signal environment. The objective is to enhance the data retrieval at cellsite during the access period, for which the optimal weight vector of the smart antenna BTS is not available. It is shown in this paper that the access channel decoder proposed in this paper outperforms the conventional one, which is based on a single antenna channel in terms of detection probability of access probe, access channel failure probability, and Walsh-code demodulation performance.

High-speed-rail tilt-train technology: A state-of-the-art survey. Final report

Energy Technology Data Exchange (ETDEWEB)

Boon, C.J.; Hayes, W.F.; Kesler, J.K.; Whitten, B.T.

1992-05-01

The report presents an assessment of the technical and operational features of existing and proposed tilt-body rail passenger vehicles. Basic concepts of railroad route selection, track geometry, and curve negotiation are reviewed, and the rationale, advantages and disadvantages associated with body tilting and the techniques used to achieve body tilt are discussed. An overview of the development status and selected key characteristics of tilt technologies are presented. Issues associated with deployment and operation of tilt-body technologies in the U..S are identified and analyzed, including a review of U.S. experience to date, areas of incompatibility of foreign tilt technology with existing U.S. equipment and infrastructure, special maintenance procedures and skill requirements, and compliance with FRA and other regulations. Appendices to the report present discussions on the physics of curve negotiation for conventional and tilting vehicles, the principles of tilting and tilt control strategies and mechanisms, and a description and technical characterization of the principal tilt technologies.

Angular momentum projection of tilted axis rotating states

Energy Technology Data Exchange (ETDEWEB)

Oi, M; Onishi, N; Tajima, N [Tokyo Univ. (Japan); Horibata, T

1998-03-01

We applied an exact angular momentum projection to three dimensional cranked HFB (3d-CHFB) states. Tilted axis rotating states (TAR) and principal axis rotating states (PAR) are compared. It is shown that TAR is more adequate than PAR for description of the back bending phenomena driven by tilted rotation or wobbling motion. (author)

The importance of prostate bed tilt during postprostatectomy intensity-modulated radiotherapy

International Nuclear Information System (INIS)

Bell, Linda J.; Cox, Jennifer; Eade, Thomas; Rinks, Marianne; Kneebone, Andrew

2014-01-01

Variations in rectal and bladder filling can create a tilt of the prostate bed, which generates the potential for a geographic miss during postprostatectomy radiotherapy. The aim of this study is to assess the effect that bladder and rectum filling has on planning target volume angle, to determine a method to assess prostate bed tilt leading to potential geographic miss, and to discuss possible implementation issues. The cone-beam computed tomography images (n = 377) of 40 patients who received postprostatectomy radiotherapy with intensity-modulated radiotherapy were reviewed. The amount of tilt in the prostate bed was defined as the angle change between 2 surgical clips, one in the upper prostate bed and another in the lower. A potential geographic miss was defined as movement of any clip of more than 1 cm in any direction or 0.5 cm posteriorly when aligned to bone anatomy. Variations in bladder and rectum size were correlated with the degree of prostate bed tilt, and the rate of potential geographic miss was determined. A possible clinical use of prostate bed tilt was then assessed for different imaging techniques. A tilt of more than 10° was seen in 20.2% of images, which resulted in a 57.9% geographic miss rate of the superior clip. When tilt remained within 10°, there was only a 9% rate of geographic miss. Potential geographic miss of the inferior surgical clip was rare, occurring in only 1.9% of all images reviewed. The most common occurrence when the prostate bed tilt increased by more than 10° was a smaller bladder and larger rectum (6.4% of all images). The most common occurrence when the prostate bed tilt decreased by more than 10° was a larger bladder and smaller rectum (1.3% of all images). Significant prostate bed tilt (>± 10°) occurred in more than 20% of images, creating a 58% rate of geographic miss. Greatest prostate bed tilt occurred when the bladder size increased or reduced by more than 2 cm or the superior rectum size increased by more

The importance of prostate bed tilt during postprostatectomy intensity-modulated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Bell, Linda J., E-mail: Linda.Bell1@health.nsw.gov.au [Northern Sydney Cancer Centre, Radiation Oncology Department, Royal North Shore Hospital, St Leonards, New South Wales (Australia); Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales (Australia); Cox, Jennifer [Northern Sydney Cancer Centre, Radiation Oncology Department, Royal North Shore Hospital, St Leonards, New South Wales (Australia); Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales (Australia); Eade, Thomas; Rinks, Marianne; Kneebone, Andrew [Northern Sydney Cancer Centre, Radiation Oncology Department, Royal North Shore Hospital, St Leonards, New South Wales (Australia)

2014-10-01

Variations in rectal and bladder filling can create a tilt of the prostate bed, which generates the potential for a geographic miss during postprostatectomy radiotherapy. The aim of this study is to assess the effect that bladder and rectum filling has on planning target volume angle, to determine a method to assess prostate bed tilt leading to potential geographic miss, and to discuss possible implementation issues. The cone-beam computed tomography images (n = 377) of 40 patients who received postprostatectomy radiotherapy with intensity-modulated radiotherapy were reviewed. The amount of tilt in the prostate bed was defined as the angle change between 2 surgical clips, one in the upper prostate bed and another in the lower. A potential geographic miss was defined as movement of any clip of more than 1 cm in any direction or 0.5 cm posteriorly when aligned to bone anatomy. Variations in bladder and rectum size were correlated with the degree of prostate bed tilt, and the rate of potential geographic miss was determined. A possible clinical use of prostate bed tilt was then assessed for different imaging techniques. A tilt of more than 10° was seen in 20.2% of images, which resulted in a 57.9% geographic miss rate of the superior clip. When tilt remained within 10°, there was only a 9% rate of geographic miss. Potential geographic miss of the inferior surgical clip was rare, occurring in only 1.9% of all images reviewed. The most common occurrence when the prostate bed tilt increased by more than 10° was a smaller bladder and larger rectum (6.4% of all images). The most common occurrence when the prostate bed tilt decreased by more than 10° was a larger bladder and smaller rectum (1.3% of all images). Significant prostate bed tilt (>± 10°) occurred in more than 20% of images, creating a 58% rate of geographic miss. Greatest prostate bed tilt occurred when the bladder size increased or reduced by more than 2 cm or the superior rectum size increased by more

V/STOL tilt rotor aircraft study. Volume 6: Preliminary design of a composite wing for tilt rotor research aircraft

Science.gov (United States)

Soule, V. A.; Badri-Nath, Y.

1973-01-01

The results of a study of the use of composite materials in the wing of a tilt rotor aircraft are presented. An all-metal tilt rotor aircraft was first defined to provide a basis for comparing composite with metal structure. A configuration study was then done in which the wing of the metal aircraft was replaced with composite wings of varying chord and thickness ratio. The results of this study defined the design and performance benefits obtainable with composite materials. Based on these results the aircraft was resized with a composite wing to extend the weight savings to other parts of the aircraft. A wing design was then selected for detailed structural analysis. A development plan including costs and schedules to develop this wing and incorporate it into a proposed flight research tilt rotor vehicle has been devised.

Inner core tilt and polar motion

Science.gov (United States)

Dumberry, Mathieu; Bloxham, Jeremy

2002-11-01

A tilted inner core permits exchange of angular momentum between the core and the mantle through gravitational and pressure torques and, as a result, changes in the direction of Earth's axis of rotation with respect to the mantle. We have developed a model to calculate the amplitude of the polar motion that results from an equatorial torque at the inner core boundary which tilts the inner core out of alignment with the mantle. We specifically address the issue of the role of the inner core tilt in the decade polar motion known as the Markowitz wobble. We show that a decade polar motion of the same amplitude as the observed Markowitz wobble requires a torque of 1020 N m which tilts the inner core by 0.07 degrees. This result critically depends on the viscosity of the inner core; for a viscosity less than 5 × 1017 Pa s, larger torques are required. We investigate the possibility that a torque of 1020 N m with decadal periodicity can be produced by electromagnetic coupling between the inner core and torsional oscillations of the flow in the outer core. We demonstrate that a radial magnetic field at the inner core boundary of 3 to 4 mT is required to obtain a torque of such amplitude. The resulting polar motion is eccentric and polarized, in agreement with the observations. Our model suggests that equatorial torques at the inner core boundary might also excite the Chandler wobble, provided there exists a physical mechanism that can generate a large torque at a 14 month period.

Open innovation at the Abbe School of Photonics

Science.gov (United States)

Helgert, Christian; Geiss, Reinhard; Nolte, Stefan; Eilenberger, Falk; Zakoth, David; Mauroner, Oliver; Pertsch, Thomas

2017-08-01

The Abbe School of Photonics (ASP) provides and coordinates the optics and photonics education of graduate and doctoral students at the Friedrich Schiller University in Jena, Germany. The internationalized Master's degree program is the key activity in training students in the optical sciences. The program is designed to provide them with the skills necessary to fill challenging positions in industry and academia. Here, an essential factor is ASP's close collaboration with more than 20 German photonics companies. To sustain these partners' future economic development, the availability of highly qualified employees is constantly required. Accordingly, these industrial partners, the European Union, the local state and the federal German government are strongly involved in the sustainable development of ASP's curriculum by both conceptual and financial engagements. The main goal is to promote the students' academic careers and job experience in the photonics industry as well as in academia. To open up the program to students from all over the world, all ASP lectures and courses are taught in English. ASP's qualification strategy is fully research-oriented and based on the principles of academic freedom, competitive research conditions and internationalization at all levels. The education program is complemented by a structured doctoral student support and a prestigious guest professorship program. Recently, ASP and partners have started a project to build an open photonics laboratory in order to foster innovative and co-creative processes. The idea follows well-established open innovation schemes e.g. in electronics. This Photon Garage (German: "Lichtwerkstatt") will bring together professionals and interested laymen from different backgrounds to approach pertinent challenges in photonics. Here, we will share our latest insights into the potentials and opportunities offered by this novel educative approach.

Simultaneous determination of sample thickness, tilt, and electron mean free path using tomographic tilt images based on Beer-Lambert law.

Science.gov (United States)

Yan, Rui; Edwards, Thomas J; Pankratz, Logan M; Kuhn, Richard J; Lanman, Jason K; Liu, Jun; Jiang, Wen

2015-11-01

Cryo-electron tomography (cryo-ET) is an emerging technique that can elucidate the architecture of macromolecular complexes and cellular ultrastructure in a near-native state. Some important sample parameters, such as thickness and tilt, are needed for 3-D reconstruction. However, these parameters can currently only be determined using trial 3-D reconstructions. Accurate electron mean free path plays a significant role in modeling image formation process essential for simulation of electron microscopy images and model-based iterative 3-D reconstruction methods; however, their values are voltage and sample dependent and have only been experimentally measured for a limited number of sample conditions. Here, we report a computational method, tomoThickness, based on the Beer-Lambert law, to simultaneously determine the sample thickness, tilt and electron inelastic mean free path by solving an overdetermined nonlinear least square optimization problem utilizing the strong constraints of tilt relationships. The method has been extensively tested with both stained and cryo datasets. The fitted electron mean free paths are consistent with reported experimental measurements. The accurate thickness estimation eliminates the need for a generous assignment of Z-dimension size of the tomogram. Interestingly, we have also found that nearly all samples are a few degrees tilted relative to the electron beam. Compensation of the intrinsic sample tilt can result in horizontal structure and reduced Z-dimension of tomograms. Our fast, pre-reconstruction method can thus provide important sample parameters that can help improve performance of tomographic reconstruction of a wide range of samples. Copyright © 2015 Elsevier Inc. All rights reserved.

Influence of Vibrotactile Feedback on Controlling Tilt Motion After Spaceflight

Science.gov (United States)

Wood, S. J.; Rupert, A. H.; Vanya, R. D.; Esteves, J. T.; Clement, G.

2011-01-01

We hypothesize that adaptive changes in how inertial cues from the vestibular system are integrated with other sensory information leads to perceptual disturbances and impaired manual control following transitions between gravity environments. The primary goals of this ongoing post-flight investigation are to quantify decrements in manual control of tilt motion following short-duration spaceflight and to evaluate vibrotactile feedback of tilt as a sensorimotor countermeasure. METHODS. Data is currently being collected on 9 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s, body axis, thereby eliciting canal reflexes without concordant otolith or visual cues. A simple 4 tactor system was implemented to provide feedback when tilt position exceeded predetermined levels in either device. Closed-loop nulling tasks are performed during random tilt steps or sum-of-sines (TTS only) with and without vibrotactile feedback of chair position. RESULTS. On landing day the manual control performance without vibrotactile feedback was reduced by >30% based on the gain or the amount of tilt disturbance successfully nulled. Manual control performance tended to return to baseline levels within 1-2 days following landing. Root-mean-square position error and tilt velocity were significantly reduced with vibrotactile feedback. CONCLUSIONS. These preliminary results are consistent with our hypothesis that adaptive changes in vestibular processing corresponds to reduced manual control performance following G-transitions. A simple vibrotactile prosthesis improves the ability to null out tilt motion within a limited range of motion disturbances.

SYSTEMATIC ERROR REDUCTION: NON-TILTED REFERENCE BEAM METHOD FOR LONG TRACE PROFILER

International Nuclear Information System (INIS)

QIAN, S.; QIAN, K.; HONG, Y.; SENG, L.; HO, T.; TAKACS, P.

2007-01-01

Systematic error in the Long Trace Profiler (LTP) has become the major error source as measurement accuracy enters the nanoradian and nanometer regime. Great efforts have been made to reduce the systematic error at a number of synchrotron radiation laboratories around the world. Generally, the LTP reference beam has to be tilted away from the optical axis in order to avoid fringe overlap between the sample and reference beams. However, a tilted reference beam will result in considerable systematic error due to optical system imperfections, which is difficult to correct. Six methods of implementing a non-tilted reference beam in the LTP are introduced: (1) application of an external precision angle device to measure and remove slide pitch error without a reference beam, (2) independent slide pitch test by use of not tilted reference beam, (3) non-tilted reference test combined with tilted sample, (4) penta-prism scanning mode without a reference beam correction, (5) non-tilted reference using a second optical head, and (6) alternate switching of data acquisition between the sample and reference beams. With a non-tilted reference method, the measurement accuracy can be improved significantly. Some measurement results are presented. Systematic error in the sample beam arm is not addressed in this paper and should be treated separately

Perbaikan Pengelolaan Pergudangan Melalui Penerapan Sistem Informasi Pergudangan di CV. ABB

Directory of Open Access Journals (Sweden)

Hery Hamdi Azwir

2017-05-01

Full Text Available Warehousing management problems that exist in the CV. ABB is the management of warehouses that are susceptible to manipulation of data, methods of work are still very manual such as recording a spare part only handwritten by the warehouse, frequent loss of spare parts in the warehouse, the bon false, and the lack of supervision instruments for oversee the spare parts in the warehouse. To overcome these problems, then made improvements through the implementation of warehouse management information system. Improvements in the form of procurement supervision instruments using the application PHP7 and MySQL, because the existence of the application makes it easy to keep an eye on spare parts in the warehouse, ranging from spare part comes in, spare part out, anyone who requests a part, stock of spare parts of existing in the warehouse, stock outs are used to help finance the manufacture purchase order, reports the spare parts that go into the warehouse of the supplier and request a report part. Not only is it a system of warehousing information can facilitate in making purchase order finance and carry out the approval of the request part of the user. Thus the system becomes more transparent.

Modulation of internal estimates of gravity during and after prolonged roll-tilts.

Directory of Open Access Journals (Sweden)

Alexander A Tarnutzer

Full Text Available Perceived direction of gravity, as assessed by the subjective visual vertical (SVV, shows roll-angle dependent errors that drift over time and a bias upon return to upright. According to Bayesian observer theory, the estimated direction of gravity is derived from the posterior probability distribution by combining sensory input and prior knowledge about earth-vertical in a statistically optimal fashion. Here we aimed to further characterize the stability of SVV during and after prolonged roll-tilts. Specifically we asked whether the post-tilt bias is related to the drift pattern while roll-tilted. Twenty-nine healthy human subjects (23-56 yo repetitively adjusted a luminous arrow to the SVV over periods of 5 min while upright, roll-tilted (± 45°, ± 90°, and immediately after returning to upright. Significant (p<0.05 drifts (median absolute drift-amplitude: 10°/5 min were found in 71% (± 45° and 78% (± 90° of runs. At ± 90° roll-tilt significant increases in absolute adjustment errors were more likely (76%, whereas significant increases (56% and decreases (44% were about equally frequent at ± 45°. When returning to upright, an initial bias towards the previous roll-position followed by significant exponential decay (median time-constant: 71 sec was noted in 47% of all runs (all subjects pooled. No significant correlations were found between the drift pattern during and immediately after prolonged roll-tilt. We conclude that the SVV is not stable during and after prolonged roll-tilt and that the direction and magnitude of drift are individually distinct and roll-angle-dependent. Likely sensory and central adaptation and random-walk processes contribute to drift while roll-tilted. Lack of correlation between the drift and the post-tilt bias suggests that it is not the inaccuracy of the SVV estimate while tilted that determines post-tilt bias, but rather the previous head-roll orientation relative to gravity. We therefore favor central

Exploiting Phase Diversity for CDMA2000 1X Smart Antenna Base Stations

Directory of Open Access Journals (Sweden)

Hyeon Seungheon

2004-01-01

Full Text Available A performance analysis of an access channel decoder is presented which exploits a diversity gain due to the independent magnitude of received signals energy at each of the antenna elements of a smart-antenna base-station transceiver subsystem (BTS operating in CDMA2000 1X signal environment. The objective is to enhance the data retrieval at cellsite during the access period, for which the optimal weight vector of the smart antenna BTS is not available. It is shown in this paper that the access channel decoder proposed in this paper outperforms the conventional one, which is based on a single antenna channel in terms of detection probability of access probe, access channel failure probability, and Walsh-code demodulation performance.

Effects of external feedback about body tilt: Influence on the Subjective Proprioceptive Horizon.

Science.gov (United States)

Bringoux, L; Bourdin, C; Nougier, V; Raphel, C

2006-11-06

The present study investigated a cognitive aspect upon spatial perception, namely the impact of a true or false verbal feedback (FB) about the magnitude of body tilt on Subjective Proprioceptive Horizon (SPH) estimates. Subjects were asked to set their extended arm normal to gravity for different pitch body tilts up to 9 degrees . True FB were provided at all body tilt angles, whereas false FB were provided only at 6 degrees backward and 6 degrees forward body tilts for half of the trials. Our data confirmed previous results about the egocentric influence of body tilt itself upon SPH: estimates were linearly lowered with forward tilts and elevated with backward tilts. In addition, results showed a significant effect of the nature of the external FB provided to the subjects. When subjects received a false FB inducing a 3 degrees forward bias relative to physical body tilt, they set their SPH consequently higher than when they received a false FB inducing a 3 degrees backward bias. These findings clearly indicated that false cognitive information about body tilt might significantly modify the judgement of a geocentric direction of space, such as the SPH. This may have deleterious repercussions in aeronautics when pilots have to localize external objects relative to earth-based directions in darkened environments.

Research on calculation of the IOL tilt and decentration based on surface fitting.

Science.gov (United States)

Li, Lin; Wang, Ke; Yan, Yan; Song, Xudong; Liu, Zhicheng

2013-01-01

The tilt and decentration of intraocular lens (IOL) result in defocussing, astigmatism, and wavefront aberration after operation. The objective is to give a method to estimate the tilt and decentration of IOL more accurately. Based on AS-OCT images of twelve eyes from eight cases with subluxation lens after operation, we fitted spherical equation to the data obtained from the images of the anterior and posterior surfaces of the IOL. By the established relationship between IOL tilt (decentration) and the scanned angle, at which a piece of AS-OCT image was taken by the instrument, the IOL tilt and decentration were calculated. IOL tilt angle and decentration of each subject were given. Moreover, the horizontal and vertical tilt was also obtained. Accordingly, the possible errors of IOL tilt and decentration existed in the method employed by AS-OCT instrument. Based on 6-12 pieces of AS-OCT images at different directions, the tilt angle and decentration values were shown, respectively. The method of the surface fitting to the IOL surface can accurately analyze the IOL's location, and six pieces of AS-OCT images at three pairs symmetrical directions are enough to get tilt angle and decentration value of IOL more precisely.

Research on Calculation of the IOL Tilt and Decentration Based on Surface Fitting

Directory of Open Access Journals (Sweden)

Lin Li

2013-01-01

Full Text Available The tilt and decentration of intraocular lens (IOL result in defocussing, astigmatism, and wavefront aberration after operation. The objective is to give a method to estimate the tilt and decentration of IOL more accurately. Based on AS-OCT images of twelve eyes from eight cases with subluxation lens after operation, we fitted spherical equation to the data obtained from the images of the anterior and posterior surfaces of the IOL. By the established relationship between IOL tilt (decentration and the scanned angle, at which a piece of AS-OCT image was taken by the instrument, the IOL tilt and decentration were calculated. IOL tilt angle and decentration of each subject were given. Moreover, the horizontal and vertical tilt was also obtained. Accordingly, the possible errors of IOL tilt and decentration existed in the method employed by AS-OCT instrument. Based on 6–12 pieces of AS-OCT images at different directions, the tilt angle and decentration values were shown, respectively. The method of the surface fitting to the IOL surface can accurately analyze the IOL’s location, and six pieces of AS-OCT images at three pairs symmetrical directions are enough to get tilt angle and decentration value of IOL more precisely.

Magnetic domain-wall tilting due to domain-wall speed asymmetry

Science.gov (United States)

Kim, Dae-Yun; Park, Min-Ho; Park, Yong-Keun; Kim, Joo-Sung; Nam, Yoon-Seok; Hwang, Hyun-Seok; Kim, Duck-Ho; Je, Soong-Geun; Min, Byoung-Chul; Choe, Sug-Bong

2018-04-01

Broken symmetries in diverse systems generate a number of intriguing phenomena and the analysis on such broken symmetries often provides decisive clues for exploring underlying physics in the systems. Recently, in magnetic thin-film systems, the Dzyaloshinskii-Moriya interaction (DMI)—induced by the broken symmetry of structural inversion—accounts for various chiral phenomena, which are of timely issues in spintronics. Here, we report an experimental observation on unexpected tilting of magnetic domain walls (DWs) due to the broken symmetry under the application of the magnetic field transverse to the magnetic wire systems. It has been predicted that the DMI possibly causes such DW tilting in the direction of the energy minimization. However, very interestingly, experimental observation reveals that the DW tilting does not follow the prediction based on the energy minimization, even for the tilting direction. Instead, the DW tilting is governed by the DW speed asymmetry that is initiated by the DW pinning at wire edges. A simple analytic model is proposed in consideration of the DW speed asymmetry at wire edges, which successfully explains the experimental observation of the DW tilting directions and angles, as confirmed by numerical simulation. The present study manifests the decisive role of the DW pinning with the DW speed asymmetry, which determines the DW configuration and consequently, the dynamics.

Retinal Nerve Fiber Layer Protrusion Associated with Tilted Optic Discs.

Science.gov (United States)

Chiang, Jaclyn; Yapp, Michael; Ly, Angelica; Hennessy, Michael P; Kalloniatis, Michael; Zangerl, Barbara

2018-03-01

This study resulted in the identification of an optic nerve head (ONH) feature associated with tilted optic discs, which might potentially contribute to ONH pathologies. Knowledge of such findings will enhance clinical insights and drive future opportunities to understand disease processes related to tilted optic discs. The aim of this study was to identify novel retinal nerve fiber layer (RNFL) anomalies by evaluating tilted optic discs using optical coherence tomography. An observed retinal nerve fiber protrusion was further investigated for association with other morphological or functional parameters. A retrospective review of 400 randomly selected adult patients with ONH examinations was conducted in a referral-only, diagnostic imaging center. After excluding other ONH pathologies, 215 patients were enrolled and evaluated for optic disc tilt and/or torsion. Gross anatomical ONH features, including size and rim or parapapillary region elevation, were assessed with stereoscopic fundus photography. Optical coherence tomography provided detailed morphological information of individual retinal layers. Statistical analysis was applied to identify significant changes between individual patient cohorts. A dome-shaped hyperreflective RNFL bulge, protruding into the neurosensory retina at the optic disc margins, was identified in 17 eyes with tilted optic discs. Available follow-up data were inconclusive regarding natural changes with this ONH feature. This RNFL herniation was significantly correlated with smaller than average optic disc size (P = .005), congenital disc tilt (P optic discs, which has not previously been assessed as an independent ONH structure. The feature is predominantly related to congenital crowded, small optic discs and variable between patients. This study is an important first step to elucidate diagnostic capabilities of tilted disc morphological changes and understanding associated functional deficits.

Mechanisms of Günther Tulip filter tilting during transfemoral placement.

Science.gov (United States)

Matsui, Y; Horikawa, M; Ohta, K; Jahangiri Noudeh, Y; Kaufman, J A; Farsad, K

The purpose of this study was to characterize the mechanisms of Günther Tulip filter (GTF) tilting during transfemoral placement in an experimental model with further validation in a clinical series. In an experimental study, 120 GTF placements in an inferior vena cava (IVC) model were performed using 6 configurations of pre-deployment filter position. The angle between the pre-deployment filter axis and IVC axis, and the proximity of the constrained filter legs to IVC wall prior to deployment were evaluated. The association of those pre-deployment factors with post-deployment filter tilting was analyzed. The association noted in the experimental study was then evaluated in a retrospective clinical series of 21 patients. In the experimental study, there was a significant association between the pre-deployment angle and post-deployment filter tilting (P<0.0001). With a low pre-deployment angle (≤5°), a significant association was noted between filter tilting and the proximity of the constrained filter legs to the far IVC wall (P=0.001). In a retrospective clinical study, a significant association between the pre-deployment angle and post-deployment filter tilting was also noted with a linear regression model (P=0.026). Significant association of the pre-deployment angle with post-deployment GTF tilting was shown in both the experimental and clinical studies. The experimental study also showed that proximity of filter legs is relevant when pre-deployment angle is small. Addressing these factors may result in a lower incidence of filter tilting. Copyright © 2017 Editions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Numerical modelling of the tilt casting processes of titanium alumindes

OpenAIRE

Wang, Hong

2008-01-01

This research has investigated the modelling and optimisation of the tilt casting process of Titanium Aluminides (TiAl). This study is carried out in parallel with the experimental research undertaken in IRC at the University of Birmingham. They propose to use tilt casting inside a vacuum chamber and attempt to combine this tilt casting process with Induction Skull Melting (ISM). A totally novel process is developing for investment casting, which is suitable for casting gamma TiAl.\\ud \\ud As ...

Tilting-connected symmetric algebras

OpenAIRE

Aihara, Takuma

2010-01-01

The notion of silting mutation was introduced by Iyama and the author. In this paper we mainly study silting mutation for self-injective algebras and prove that any representation-finite symmetric algebra is tilting-connected. Moreover we give some sufficient conditions for a Bongartz-type Lemma to hold for silting objects.

Rigidity of tilting modules

DEFF Research Database (Denmark)

Haahr Andersen, Henning; Kaneda, Masaharu

Let $U_q$ denote the quantum group associated with a finite dimensional semisimple Lie algebra. Assume that $q$ is a complex root of unity of odd order and that $U_q$ is %the quantum group version obtained via Lusztig's $q$-divided powers construction. We prove that all regular projective (tilting...

Velocity dependence of vestibular information for postural control on tilting surfaces

Science.gov (United States)

Kluzik, JoAnn; Hlavacka, Frantisek

2016-01-01

Vestibular information is known to be important for postural stability on tilting surfaces, but the relative importance of vestibular information across a wide range of surface tilt velocities is less clear. We compared how tilt velocity influences postural orientation and stability in nine subjects with bilateral vestibular loss and nine age-matched, control subjects. Subjects stood on a force platform that tilted 6 deg, toes-up at eight velocities (0.25 to 32 deg/s), with and without vision. Results showed that visual information effectively compensated for lack of vestibular information at all tilt velocities. However, with eyes closed, subjects with vestibular loss were most unstable within a critical tilt velocity range of 2 to 8 deg/s. Subjects with vestibular deficiency lost their balance in more than 90% of trials during the 4 deg/s condition, but never fell during slower tilts (0.25–1 deg/s) and fell only very rarely during faster tilts (16–32 deg/s). At the critical velocity range in which falls occurred, the body center of mass stayed aligned with respect to the surface, onset of ankle dorsiflexion was delayed, and there was delayed or absent gastrocnemius inhibition, suggesting that subjects were attempting to actively align their upper bodies with respect to the moving surface instead of to gravity. Vestibular information may be critical for stability at velocities of 2 to 8 deg/s because postural sway above 2 deg/s may be too fast to elicit stabilizing responses through the graviceptive somatosensory system, and postural sway below 8 deg/s may be too slow for somatosensory-triggered responses or passive stabilization from trunk inertia. PMID:27486101

Internationalized and research-oriented photonics education: Abbe School of Photonics

Science.gov (United States)

Helgert, Christian; Nolte, Stefan; Pertsch, Thomas

2015-10-01

The Abbe School of Photonics (ASP) provides and coordinates the optics and photonics education of graduate and doctoral students at the Friedrich Schiller University in Jena, Germany. The internationalized Master's degree program is the key activity in training students in the optical sciences. The program is designed to provide them with the skills necessary to fill challenging positions in industry and academia. Here, an essential factor is ASP's close collaboration with more than 20 German photonics companies. To sustain these partners' future economic development, the availability of highly qualified employees is constantly required. Accordingly, these industrial partners, the European Union, the local state and the federal German government are strongly involved in the sustainable development of ASP's curriculum by both conceptual and financial engagements. The main goal is to promote the students' academic careers and job experience in the photonics industry as well as in academia. To open up the program to students from all over the world, all ASP lectures and courses are taught in English. Since 2009, more than 250 graduate students from more than 40 different countries have been enrolled at the School. Almost 90% of them of non-German nationality, fulfilling the essential ASP philosophy to locally establish an international education program. ASP's qualification strategy is fully research-oriented and based on the principles of academic freedom, competitive research conditions and internationalization at all levels. The education program is complemented by a structured doctoral student support and a prestigious guest professorship program.

Ambiguous Tilt and Translation Motion Cues in Astronauts after Space Flight

Science.gov (United States)

Clement, G.; Harm, D. L.; Rupert, A. H.; Beaton, K. H.; Wood, S. J.

2008-01-01

Adaptive changes during space flight in how the brain integrates vestibular cues with visual, proprioceptive, and somatosensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions following transitions between gravity levels. This joint ESA-NASA pre- and post-flight experiment is designed to examine both the physiological basis and operational implications for disorientation and tilt-translation disturbances in astronauts following short-duration space flights. The first specific aim is to examine the effects of stimulus frequency on adaptive changes in eye movements and motion perception during independent tilt and translation motion profiles. Roll motion is provided by a variable radius centrifuge. Pitch motion is provided by NASA's Tilt-Translation Sled in which the resultant gravitoinertial vector remains aligned with the body longitudinal axis during tilt motion (referred to as the Z-axis gravitoinertial or ZAG paradigm). We hypothesize that the adaptation of otolith-mediated responses to these stimuli will have specific frequency characteristics, being greatest in the mid-frequency range where there is a crossover of tilt and translation. The second specific aim is to employ a closed-loop nulling task in which subjects are tasked to use a joystick to null-out tilt motion disturbances on these two devices. The stimuli consist of random steps or sum-of-sinusoids stimuli, including the ZAG profiles on the Tilt-Translation Sled. We hypothesize that the ability to control tilt orientation will be compromised following space flight, with increased control errors corresponding to changes in self-motion perception. The third specific aim is to evaluate how sensory substitution aids can be used to improve manual control performance. During the closed-loop nulling task on both devices, small tactors placed around the torso vibrate according to the actual body tilt angle relative to gravity. We hypothesize

Optimization of a tunneling barrier in magnetic tunneling junction by tilted-plasma oxidation

International Nuclear Information System (INIS)

Nam, C.H.; Shim, Heejae; Kim, K.S.; Cho, B.K.

2004-01-01

Oxidation of an AlO x insulating barrier in a magnetic tunneling junction (MTJ) was carried out by a tilted-plasma oxidation method. It was found that the tilted-plasma oxidation induced a gradual change in the extent of oxidation of an insulating layer, which consequently led to a gradual change in the tunneling magnetoresistance (TMR) and specific junction resistance (RA) of the MTJ. We found a linear relation in the TMR versus RA curve with positive and negative slopes for less- and overoxidized junctions, respectively, and a parabolic relation for optimally oxidized junctions. The crossover in the TMR versus RA curves provides an effective and useful way to optimize (and monitor) the oxidation condition of a tunneling barrier in MTJs especially of a tunneling barrier less than 10 A thick. The tunneling junctions were also investigated after thermal annealing at various temperatures. The observations after thermal annealing were found to be consistent with transmission electrons microscopy images and a scenario of the partial formation of an additional ultrathin tunneling barrier at the top surface of the bottom magnetic layer

Head tilt produced by hemilabyrinthectomy does not depend on the direct vestibulospinal tracts.

Science.gov (United States)

Fukushima, K; Fukushima, J; Kato, M

1988-01-01

Head tilt is one of the most characteristic and enduring symptoms produced by hemilabyrinthectomy and is compensated by the central nervous system with time. In order to study the central mechanisms of compensation of the head tilt, it is first necessary to understand how it is produced. However, its mechanism remains unknown. Experiments were performed in cats to examine whether the direct vestibulocollic pathways are responsible for the head tilt, as suggested by some authors. Hemilabyrinthectomies produced a characteristic head tilt in cats in which the medial and/or one lateral vestibulospinal tracts (VSTs) had been interrupted. The lesions of the medial VST did not influence the preexisting head tilt produced by hemilabyrinthectomies. These results suggest that the head tilt produced by hemilabyrinthectomies does not depend on the activity of the VSTs.

Interpretation of chest radiographs with a high-resolution (2,000 x 2,000 x 12 bit) display

International Nuclear Information System (INIS)

Cox, G.G.

1989-01-01

This paper presents an evaluation of high-resolution (2K x 2Kx 12 bit) display for interpretation of chest radiographs. Three radiologists chose a total of 165 chest radiographs to ensure representation of nine signs: apical pleural scarring, chronic obstructive pulmonary disease, interstitial processes, atelectasis, pneumothorax, hilar mass, pleural effusion, pneumonia, and nodules. Each chest film was digitized to 4Kx 4Kx 12 bit and averaged to 2Kx 2Kx 12 bit and printed on a laser film printer. The 2K x 2K x 12-bit images were displayed and interactively windowed on a 2K x 2K x 12-bit high-resolution gray-scale cathode ray tube display. Six radiologists, none of whom participated in the case selection process, then interpreted a mixture of the screen film chest radiographs, the laser printed 2K chest radiographs, and the high resolution displayed 2K images

Modeling Flow Past a Tilted Vena Cava Filter

Energy Technology Data Exchange (ETDEWEB)

Singer, M A; Wang, S L

2009-06-29

Inferior vena cava filters are medical devices used to prevent pulmonary embolism (PE) from deep vein thrombosis. In particular, retrievable filters are well-suited for patients who are unresponsive to anticoagulation therapy and whose risk of PE decreased with time. The goal of this work is to use computational fluid dynamics to evaluate the flow past an unoccluded and partially occluded Celect inferior vena cava filter. In particular, the hemodynamic response to thrombus volume and filter tilt is examined, and the results are compared with flow conditions that are known to be thrombogenic. A computer model of the filter inside a model vena cava is constructed using high resolution digital photographs and methods of computer aided design. The models are parameterized using the Overture software framework, and a collection of overlapping grids is constructed to discretize the flow domain. The incompressible Navier-Stokes equations are solved, and the characteristics of the flow (i.e., velocity contours and wall shear stresses) are computed. The volume of stagnant and recirculating flow increases with thrombus volume. In addition, as the filter increases tilt, the cava wall adjacent to the tilted filter is subjected to low velocity flow that gives rise to regions of low wall shear stress. The results demonstrate the ease of IVC filter modeling with the Overture software framework. Flow conditions caused by the tilted Celect filter may elevate the risk of intrafilter thrombosis and facilitate vascular remodeling. This latter condition also increases the risk of penetration and potential incorporation of the hook of the filter into the vena caval wall, thereby complicating filter retrieval. Consequently, severe tilt at the time of filter deployment may warrant early clinical intervention.

Simulations of Micropumps Based on Tilted Flexible Fibers

Science.gov (United States)

Hancock, Matthew; Elabbasi, Nagi; Demirel, Melik

2015-11-01

Pumping liquids at low Reynolds numbers is challenging because of the principle of reversibility. We report here a class of microfluidic pump designs based on tilted flexible structures that combines the concepts of cilia (flexible elastic elements) and rectifiers (e.g., Tesla valves, check valves). We demonstrate proof-of-concept with 2D and 3D fluid-structure interaction (FSI) simulations in COMSOL Multiphysics®of micropumps consisting of a source for oscillatory fluidic motion, e.g. a piston, and a channel lined with tilted flexible rods or sheets to provide rectification. When flow is against the rod tilt direction, the rods bend backward, narrowing the channel and increasing flow resistance; when flow is in the direction of rod tilt, the rods bend forward, widening the channel and decreasing flow resistance. The 2D and 3D simulations involve moving meshes whose quality is maintained by prescribing the mesh displacement on guide surfaces positioned on either side of each flexible structure. The prescribed displacement depends on structure bending and maintains mesh quality even for large deformations. Simulations demonstrate effective pumping even at Reynolds numbers as low as 0.001. Because rod rigidity may be specified independently of Reynolds number, in principle, rod rigidity may be reduced to enable pumping at arbitrarily low Reynolds numbers.

Robust tilt and lock mechanism for hopping actuator

Energy Technology Data Exchange (ETDEWEB)

Salton, Jonathan R.; Buerger, Stephen; Dullea, Kevin J.; Marron, Lisa C.; Salisbury, Curt Michael; Spletzer, Barry Louis

2017-02-07

A tilt and lock apparatus that includes a tilt servomechanism, a spiral torsion spring, a lock wheel, and a lock hook is described herein. The spiral torsion spring is mechanically coupled to the tilt servomechanism and the lock wheel (which includes an opening). When a shaft is positioned through the opening, rotation of the lock wheel is in unison with rotation of the shaft. An external surface of the lock wheel includes one or more grooves. The lock hook includes a head that engages and disengages the grooves. The lock wheel is stationary when the head engages one of the grooves and is rotatable when the head disengages the grooves. The head and the grooves are geometrically aligned when engaged to prevent creation of a force that acts to disengage the head responsive to an applied force acting on the shaft.

Tilted wheel satellite attitude control with air-bearing table experimental results

Science.gov (United States)

Inumoh, Lawrence O.; Forshaw, Jason L.; Horri, Nadjim M.

2015-12-01

Gyroscopic actuators for satellite control have attracted significant research interest over the years, but their viability for the control of small satellites has only recently started to become clear. Research on variable speed gyroscopic actuators has long been focused on single gimbal actuators; double gimbal actuators typically operate at constant wheel spin rate and allow tilt angle ranges far larger than the ranges needed to operate most satellite missions. This research examines a tilted wheel, a newly proposed type of inertial actuator that can generate torques in all three principal axes of a rigid satellite using a spinning wheel and a double tilt mechanism. The tilt mechanism tilts the angular momentum vector about two axes providing two degree of freedom control, while variation of the wheel speed provides the third. The equations of motion of the system lead to a singularity-free system during nominal operation avoiding the need for complex steering logic. This paper describes the hardware design of the tilted wheel and the experimental setup behind both standalone and spherical air-bearing tables used to test it. Experimental results from the air bearing table are provided with the results depicting the high performance capabilities of the proposed actuator in torque generation.

Quantum well electronic states in a tilted magnetic field.

Science.gov (United States)

Trallero-Giner, C; Padilha, J X; Lopez-Richard, V; Marques, G E; Castelano, L K

2017-08-16

We report the energy spectrum and the eigenstates of conduction and uncoupled valence bands of a quantum well under the influence of a tilted magnetic field. In the framework of the envelope approximation, we implement two analytical approaches to obtain the nontrivial solutions of the tilted magnetic field: (a) the Bubnov-Galerkin spectral method and b) the perturbation theory. We discuss the validity of each method for a broad range of magnetic field intensity and orientation as well as quantum well thickness. By estimating the accuracy of the perturbation method, we provide explicit analytical solutions for quantum wells in a tilted magnetic field configuration that can be employed to study several quantitative phenomena.

Bi-epitaxial YBa2Cu3Ox Thin Films on Tilted-axes NdGaO3 Substrates with CeO2 Seeding Layer

International Nuclear Information System (INIS)

Mozhaev, P B; Mozhaeva, J E; Jacobsen, C S; Hansen, J Bindslev; Bdikin, I K; Luzanov, V A; Kotelyanskii, I M; Zybtsev, S G

2006-01-01

Bi-epitaxial YBa 2 Cu 3 O x (YBCO) thin films with out-of-plane tilt angle in the range 18 - 27 0 were manufactured using pulsed laser deposition on NdGaO 3 tilted-axes substrates with CeO 2 seeding layers. The YBCO thin film orientation over the seeding layer depended on deposition conditions. Removal of the seeding layer from part of the substrate surface by ionbeam etching resulted in formation of a bi-epitaxial thin film with different c-axis orientation of two parts of the film. The bi-epitaxial film orientation and structure were studied using X-ray diffraction techniques, and surface morphology was observed with atomic force microscope (AFM). Photolithography and ion-beam etching techniques were used for patterning bi-epitaxial thin films. Electrical characterization of the obtained structures was performed

Soft antiphase tilt of oxygen octahedra in the hybrid improper multiferroic Ca3Mn1.9Ti0.1O7

Science.gov (United States)

Ye, Feng; Wang, Jinchen; Sheng, Jieming; Hoffmann, C.; Gu, T.; Xiang, H. J.; Tian, Wei; Molaison, J. J.; dos Santos, A. M.; Matsuda, M.; Chakoumakos, B. C.; Fernandez-Baca, J. A.; Tong, X.; Gao, Bin; Kim, Jae Wook; Cheong, S.-W.

2018-01-01

We report a single crystal neutron and x-ray diffraction study of the hybrid improper multiferroic Ca3Mn1.9Ti0.1O7 (CMTO), a prototypical system where the electric polarization arises from the condensation of two lattice distortion modes. With increasing temperature (T ), the out-of-plane, antiphase tilt of MnO6 decreases in amplitude while the in-plane, in-phase rotation remains robust and experiences abrupt changes across the first-order structural transition. Application of hydrostatic pressure (P ) to CMTO at room temperature shows a similar effect. The consistent behavior under both T and P reveals the softness of antiphase tilt and highlights the role of the partially occupied d orbital of the transition-metal ions in determining the stability of the octahedral distortion. Polarized neutron analysis indicates the symmetry-allowed canted ferromagnetic moment is less than the 0.04 μB/Mn site, despite a substantial out-of-plane tilt of the MnO6 octahedra.

Proto-CIRCUS tilted-coil tokamak–torsatron hybrid: Design and construction

Energy Technology Data Exchange (ETDEWEB)

Clark, A.W.; Doumet, M.; Hammond, K.C. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027 (United States); Kornbluth, Y. [Yeshiva University, New York, NY 10033 (United States); Spong, D.A. [Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States); Sweeney, R. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027 (United States); Volpe, F.A., E-mail: fvolpe@columbia.edu [Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027 (United States)

2014-11-15

Highlights: • A tokamak-like device with tilted toroidal field (TF) coils needs less plasma current than a conventional tokamak. • Rotational transform is partly generated by external coils. Device can be considered a tokamak–torsatron hybrid. • We designed and constructed the first device of this type. • Tilted TF coils are interlinked to each other, which helps to reduce aspect ratio of plasma. • This is a six-coil generalization of CNT stellarator, also at Columbia University, which features two interlinked coils. - Abstract: We present the field-line modeling, design, and construction of a prototype circular-coil tokamak–torsatron hybrid called Proto-CIRCUS. The device has a major radius R = 16 cm and minor radius a < 5 cm. The six “toroidal field” coils are planar as in a tokamak, but they are tilted. This, combined with induced or driven plasma current, is expected to generate rotational transform, as seen in field-line tracing and equilibrium calculations. The device is expected to operate at lower plasma current than a tokamak of comparable size and magnetic field, which might have interesting implications for disruptions and steady-state operation. Additionally, the toroidal magnetic ripple is less pronounced than in an equivalent tokamak in which the coils are not tilted. The tilted coils are interlocked, resulting in a relatively low aspect ratio, and can be moved, both radially and in tilt angle, between discharges. This capability will be exploited for detailed comparisons between calculations and field-line mapping measurements. Such comparisons will reveal whether this relatively simple concept can generate the expected rotational transform.

The use of cubic Nd-Ba-Cu-O seeds to create θ[100], 900-θ[100], and θ[001] tilt Y-Ba-Cu-O grain boundaries

International Nuclear Information System (INIS)

Field, M. B.

1998-01-01

Using seeding techniques to control the orientation of grains, we have been able to create a wide variety of YBa 2 Cu 3 O 6+x , grain boundaries. In addition to five domain samples with 90 degree[100] twist and tilt grain boundaries, we have now developed a method to produce grain boundaries in the same sample that have the misorientations θ[001] tilt, θ[100] tilt, and 90 degree ∼ θ[100], where the disorientation angle θ is fully controllable. We will demonstrate how these boundaries can be synthesized, give experimental evidence via polarized light microscopy and electron backscatter patterns (EBSP) that the intended grain boundaries were indeed formed, and discuss the importance of these boundaries in future grain boundary studies

Tilt sensor and servo control system for gravitational wave detection

CERN Document Server

Cheng, Y; Ju, L; Blair, D G

2002-01-01

This paper describes the design of a novel double-flexure two-axis tilt sensor with a tilt readout based on an optical walk-off sensor. The performance of the device has been investigated theoretically and experimentally. The walk-off sensor has demonstrated a sensitivity of 10 sup - sup 1 sup 1 rad Hz sup - sup 1 sup / sup 2 at 1 Hz. The tilt sensor has measured seismic noise approx 10 sup - sup 9 -10 sup - sup 1 sup 0 rad Hz sup - sup 1 sup / sup 2 for frequency in the 2-10 Hz range.

Chromatic X-ray magnifying method and apparatus by Bragg reflective planes on the surface of Abbe sphere

Science.gov (United States)

Thoe, Robert S.

1991-01-01

Method and apparatus for producing sharp, chromatic, magnified images of X-ray emitting objects, are provided. The apparatus, which constitutes an X-ray microscope or telescope, comprises a connected collection of Bragg reflecting planes, comprised of either a bent crystal or a synthetic multilayer structure, disposed on and adjacent to a locus determined by a spherical surface. The individual Bragg planes are spatially oriented to Bragg reflect radiation from the object location toward the image location. This is accomplished by making the Bragg planes spatially coincident with the surfaces of either a nested series of prolate ellipsoids of revolution, or a nested series of spheres. The spacing between the Bragg reflecting planes can be tailored to control the wavelengths and the amount of the X-radiation that is Bragg reflected to form the X-ray image.

Design and Development of Tilting Rotary Furnace

Science.gov (United States)

Sai Varun, V.; Tejesh, P.; Prashanth, B. N.

2018-02-01

Casting is the best and effective technique used for manufacturing products. The important accessory for casting is furnace. Furnace is used to melt the metal. A perfect furnace is one that reduces the wastage of material, reduces the cost of manufacturing and there by reduces the cost of production. Of all the present day furnaces there may be wastage of material, and the chances of increasing the time of manufacturing as the is continuous need of tilting of the furnace for every mould and then changing the moulds. Considering these aspects, a simple and least expensive tilting rotary furnace is designed and developed. The Tilting and Rotary Furnace consists of mainly melting chamber and the base. The metal enters the melting chamber through the input door that is provided on the top of the melting chamber. Inside the melting chamber there is a graphite furnace. The metal is melted in the graphite crucible. An insulation of ceramic fibre cloth is provided inside the furnace. The metal is melted using Propane gas. The propane gas is easily available and economic. The gas is burned using a pilot burner. The pilot burner is more efficient that other burners. The pilot burner is lit with a push button igniter. The pilot burner is located at the bottom of the combustion chamber. This enables the uniform heating of the metal inside the crucible. The temperature inside the melting chamber is noted using a temperature sensor. The gas input is cut-off if the temperature is exceeding a specific temperature. After the melting of the metal is done the furnace is tilted and after the mould is filled it is rotated. The external gears are used to controlling the tilting. The results of studies carried out for the design & development of low cost, simple furnace that can be mounted anywhere on the shop floor and this can be very much useful for the education purposes and small scale manufacturing. The furnace can be rotated in 360 degrees and can help in reducing the time taken

Height and Tilt Geometric Texture

DEFF Research Database (Denmark)

Andersen, Vedrana; Desbrun, Mathieu; Bærentzen, Jakob Andreas

2009-01-01

compromise between functionality and simplicity: it can efficiently handle and process geometric texture too complex to be represented as a height field, without having recourse to full blown mesh editing algorithms. The height-and-tilt representation proposed here is fully intrinsic to the mesh, making...

Rules and mechanisms governing octahedral tilts in perovskites under pressure

Science.gov (United States)

Xiang, H. J.; Guennou, Mael; Íñiguez, Jorge; Kreisel, Jens; Bellaiche, L.

2017-08-01

The rotation of octahedra (octahedral tilting) is common in A B O3 perovskites and relevant to many physical phenomena, ranging from electronic and magnetic properties, metal-insulator transitions to improper ferroelectricity. Hydrostatic pressure is an efficient way to tune and control octahedral tiltings. However, the pressure behavior of such tiltings can dramatically differ from one material to another, with the origins of such differences remaining controversial. In this paper, we discover several new mechanisms and formulate a set of simple rules that allow us to understand how pressure affects oxygen octahedral tiltings via the use and analysis of first-principles results for a variety of compounds. Besides the known A -O interactions, we reveal that the interactions between specific B ions and oxygen ions contribute to the tilting instability. We explain the previously reported trend that the derivative of the oxygen octahedral tilting with respect to pressure (dR /dP ) usually decreases with both the tolerance factor and the ionization state of the A ion by illustrating the key role of A -O interactions and their change under pressure. Furthermore, three new mechanisms/rules are discovered, namely that (i) the octahedral rotations in A B O3 perovskites with empty low-lying d states on the B site are greatly enhanced by pressure, in order to lower the electronic kinetic energy; (ii) dR /dP is enhanced when the system possesses weak tilt instabilities, and (iii) for the most common phase exhibited by perovskites—the orthorhombic Pbnm state—the in-phase and antiphase octahedral rotations are not automatically both suppressed or both enhanced by the application of pressure because of a trilinear coupling between these two rotation types and an antipolar mode involving the A ions. We further predict that the polarization associated with the so-called hybrid improper ferroelectricity could be manipulated by hydrostatic pressure by indirectly controlling the

Comparison of Modelled and Measured Tilted Solar Irradiance for Photovoltaic Applications

Directory of Open Access Journals (Sweden)

Riyad Mubarak

2017-10-01

Full Text Available This work assesses the performance of five transposition models that estimate the global and diffuse solar irradiance on tilted planes based on the global horizontal irradiance. The modelled tilted irradiance values are compared to measured one-minute values from pyranometers and silicon sensors tilted at different angles at Hannover (Germany and NREL (Golden, CO, USA. It can be recognized that the deviations of the model of Liu and Jordan, Klucher and Perez from the measurements increases as the tilt angle increases and as the sensors are oriented away from the south direction, where they receive lower direct radiation than south-oriented surfaces. Accordingly, the vertical E, W and N planes show the highest deviation. Best results are found by the models from Hay and Davies and Reindl, when horizontal pyranometer measurements and a constant albedo value of 0.2 are used. The relative root mean squared difference (rRMSD of the anisotropic models does not exceed 11% for south orientation and low inclination angles (β = 10–60°, but reaches up to 28.9% at vertical planes. For sunny locations such as Golden, the Perez model provides the best estimates of global tilted irradiance for south-facing surfaces. The relative mean absolute difference (rMAD of the Perez model at NREL ranges from 4.2% for 40° tilt to 8.7% for 90° tilt angle, when horizontal pyranometer measurements and a measured albedo value are used; the use of measured albedo values instead of a constant value of 0.2 leads to a reduction of the deviation to 3.9% and 6.0%, respectively. The use of higher albedo values leads to a significant increase of rMAD. We also investigated the uncertainty resulting from using horizontal pyranometer measurements, in combination with constant albedo values, to estimate the incident irradiance on tilted photovoltaic (PV modules. We found that these uncertainties are small or negligible.

Evaluation of various procedures transposing global tilted irradiance to horizontal surface irradiance

Science.gov (United States)

Housmans, Caroline; Bertrand, Cédric

2017-02-01

Many transposition models have been proposed in the literature to convert solar irradiance on the horizontal plane to that on a tilted plane. The inverse process, i.e. the conversion from tilted to horizontal is investigated here based upon seven months of in-plane global solar irradiance measurements recorded on the roof of the Royal Meteorological Institute of Belgium's radiation tower in Uccle (Longitude 4.35° E, Latitude 50.79° N). Up to three pyranometers mounted on inclined planes of different tilts and orientations were involved in the inverse transposition process. Our results indicate that (1) the tilt to horizontal irradiance conversion is improved when measurements from more than one tilted pyranometer are considered (i.e. by using a multi-pyranometer approach) and (2) the improvement from using an isotropic model to anisotropic models in the inverse transposition problem is not significant.

Modelling and simulation of a compliant tilting pad air bearing

NARCIS (Netherlands)

Duijnhouwer, F.; Nijmeijer, H.

The compliant tilting pad air bearing concept, a tilting pad bearing with the pivot of the pads placed on radial springs, is a promising aerodynamic bearing solution. Nevertheless, its non-linear dynamics make a time domain dynamic simulation model an essential tool for the design of rotor systems

SU-E-T-230: Creating a Large Number of Focused Beams with Variable Patient Head Tilt to Improve Dose Fall-Off for Brain Radiosurgery

Energy Technology Data Exchange (ETDEWEB)

Chiu, J; Ma, L [Department of Radiation Oncology, University of California San Francisco School of Medicine, San Francisco, CA (United States)

2015-06-15

Purpose: To develop a treatment delivery and planning strategy by increasing the number of beams to minimize dose to brain tissue surrounding a target, while maximizing dose coverage to the target. Methods: We analyzed 14 different treatment plans via Leksell PFX and 4C. For standardization, single tumor cases were chosen. Original treatment plans were compared with two optimized plans. The number of beams was increased in treatment plans by varying tilt angles of the patient head, while maintaining original isocenter and the beam positions in the x-, y- and z-axes, collimator size, and beam blocking. PFX optimized plans increased beam numbers with three pre-set tilt angles, 70, 90, 110, and 4C optimized plans increased beam numbers with tilt angles increasing arbitrarily from range of 30 to 150 degrees. Optimized treatment plans were compared dosimetrically with original treatment plans. Results: Comparing total normal tissue isodose volumes between original and optimized plans, the low-level percentage isodose volumes decreased in all plans. Despite the addition of multiple beams up to a factor of 25, beam-on times for 1 tilt angle versus 3 or more tilt angles were comparable (<1 min.). In 64% (9/14) of the studied cases, the volume percentage decrease by >5%, with the highest value reaching 19%. The addition of more tilt angles correlates to a greater decrease in normal brain irradiated volume. Selectivity and coverage for original and optimized plans remained comparable. Conclusion: Adding large number of additional focused beams with variable patient head tilt shows improvement for dose fall-off for brain radiosurgery. The study demonstrates technical feasibility of adding beams to decrease target volume.

SU-E-T-230: Creating a Large Number of Focused Beams with Variable Patient Head Tilt to Improve Dose Fall-Off for Brain Radiosurgery

International Nuclear Information System (INIS)

Chiu, J; Ma, L

2015-01-01

Purpose: To develop a treatment delivery and planning strategy by increasing the number of beams to minimize dose to brain tissue surrounding a target, while maximizing dose coverage to the target. Methods: We analyzed 14 different treatment plans via Leksell PFX and 4C. For standardization, single tumor cases were chosen. Original treatment plans were compared with two optimized plans. The number of beams was increased in treatment plans by varying tilt angles of the patient head, while maintaining original isocenter and the beam positions in the x-, y- and z-axes, collimator size, and beam blocking. PFX optimized plans increased beam numbers with three pre-set tilt angles, 70, 90, 110, and 4C optimized plans increased beam numbers with tilt angles increasing arbitrarily from range of 30 to 150 degrees. Optimized treatment plans were compared dosimetrically with original treatment plans. Results: Comparing total normal tissue isodose volumes between original and optimized plans, the low-level percentage isodose volumes decreased in all plans. Despite the addition of multiple beams up to a factor of 25, beam-on times for 1 tilt angle versus 3 or more tilt angles were comparable (<1 min.). In 64% (9/14) of the studied cases, the volume percentage decrease by >5%, with the highest value reaching 19%. The addition of more tilt angles correlates to a greater decrease in normal brain irradiated volume. Selectivity and coverage for original and optimized plans remained comparable. Conclusion: Adding large number of additional focused beams with variable patient head tilt shows improvement for dose fall-off for brain radiosurgery. The study demonstrates technical feasibility of adding beams to decrease target volume

Synthesis and characterization of Sr{sub 2}Ir{sub 1-x}M{sub x}O{sub 4} (M=Ti, Fe, Co) solid solutions

Energy Technology Data Exchange (ETDEWEB)

Gatimu, Alvin J.; Berthelot, Romain; Muir, Sean; Sleight, Arthur W. [Department of Chemistry, Oregon State University, Corvallis, OR 97331 (United States); Subramanian, M.A., E-mail: mas.subramanian@oregonstate.edu [Department of Chemistry, Oregon State University, Corvallis, OR 97331 (United States)

2012-06-15

The effects of Ti, Fe and Co substitutions for Ir on the structure and on the physical properties of Sr{sub 2}IrO{sub 4} are investigated. A complete solid solution Sr{sub 2}Ir{sub 1-x}Ti{sub x}O{sub 4} is obtained while both Fe and Co doping are relatively limited. In each case however, the c-axis cell parameter and the initial IrO{sub 6} octahedra tilting decreases with substitution. Doping with Ti, Fe and Co results in a decrease of the magnetic susceptibility and in an increase in the paramagnetic effective moment for Co and Fe doped samples and a suppression of the weak ferromagnetic ordering observed for Sr{sub 2}IrO{sub 4}. - Graphical abstract: Solid solutions of Sr{sub 2}Ir{sub 1-x}M{sub x}O{sub 4} (M=Ti, Fe, Co) have been synthesized and characterized by powder X-ray diffraction, magnetism and electrical measurements. Changes in the a parameter and decreases in both the c-axis cell parameters and the initial IrO{sub 6} octahedra tilting are found to be correlated. Highlights: Black-Right-Pointing-Pointer Solid Solutions of Sr{sub 2}Ir{sub 1-x}M{sub x}O{sub 4} (M=Ti, Fe, Co) are synthesized. Black-Right-Pointing-Pointer The Sr{sub 2}Ir{sub 1-x}Ti{sub x}O{sub 4} solid solution is complete while those of Fe and Co are relatively limited. Black-Right-Pointing-Pointer The change in a cell parameter with substitution is much less than that of the c parameter. Black-Right-Pointing-Pointer Decreased tilting and the smaller size of the M cation contrastingly affect the a parameter. Black-Right-Pointing-Pointer Doping results in a suppression of the weak ferromagnetic ordering in Sr{sub 2}IrO{sub 4}.

Do tilt-in-space wheelchairs increase occupational engagement: a critical literature review.

Science.gov (United States)

Harrand, Jenny; Bannigan, Katrina

2016-01-01

A wheelchair can enhance the quality of life of an individual with limited mobility, poor trunk control and stability, by enabling activity and participation and so occupational engagement. High specification wheelchairs which can tilt-in-space enable the position of users to be altered to suit activity and context. Despite tilt-in-space wheelchairs being expensive little is known about their therapeutic value. A critical literature review of the evidence was undertaken to evaluate whether the use of tilt-in-space increases occupational engagement. A wide ranging search strategy identified 170 articles which were screened using inclusion criteria. The eligible literature (n = 6) was analysed thematically using open coding. The majority of the participants used tilt-in-space but the data was too heterogeneous to combine. Measures of occupational engagement were not used so the therapeutic value could not be assessed. There is a lack of high quality evidence about the therapeutic benefits of tilt-in-space wheelchairs. Given the expense associated with providing these wheelchairs, and the increase in their provision, research is needed to justify provision of high specification wheelchairs to meet the occupational needs of users within the limited resources of health and social care. Implications for Rehabilitation Tilt-in-space wheelchairs. Wheelchairs are an important and essential assistive device for promoting independence and function. Suggests there are benefits for tilt-in-space wheelchairs. Identifies the need for additional large scale research.

Development of a tilting system for electric multiple unit to speed up on conventional lines

International Nuclear Information System (INIS)

Seo, Sung Il; Kim, Nam Po; Lee, Soo Gil; Kim, Seok Won

2008-01-01

An advanced tilting system for KTT (Korean Tilting Train) was developed and a performance test of the system has been completed. KTT has been constructed to speed up and promise a significant enhancement in service quality on a conventional line. KTT is an electric multiple unit composed of 6 cars running at the design speed of 200 km/h. The tilting system is the core technology of KTT and combined with the conventional bogie system. It has a self-steering mechanism and a swing link. The self-steering mechanism of Z-bar type is free to rotate on the curve and stable to run on a straight line. The swing link mechanism of the bolster enables the carbody to tilt up to 8 .deg.. A tilting control system detects a curve with sensors and commands the electro-mechanical actuators to move the bolster through the computer network system. GPS collaborates with the tilting system to perceive the curve previously and enables gradual tilting so as not to violate passenger comfort. The performance of the tilting system has been verified by a trial test running of KTT on a commercial conventional line. The tilting system is ready for commercial use

Substorm onset location and dipole tilt angle

Directory of Open Access Journals (Sweden)

J. Wanliss

2006-03-01

Full Text Available From an initial data set of over 200 substorms we have studied a subset of 30 magnetospheric substorms close to magnetic midnight to investigate, in a statistical fashion, the source region of the auroral arc that brightens at the onset of expansive phase. This arc is usually identified as the ionospheric signature of the expansive phase onset that occurs in the magnetotail. All the substorm onsets were identified via ground-based magnetometer and photometer data from the CANOPUS array. Various Tsyganenko global magnetic field models were used to map magnetic field lines from the location of the onset arc out to its greatest radial distance in the magnetotail. The results appear to favour the current disruption model of substorms since the average onset location has an average of 14.1 Earth radii (RE and is therefore more consistent with theories that place the onset location in the inner magnetotail. For the narrow range of tilts available our modeling indicates the parameter that appears to strongly influence the location of the substorm onset is the dipole tilt angle; as tilt becomes less negative onsets occur further downtail.

Two Red Clumps and the X-shaped Milky Way Bulge

Science.gov (United States)

McWilliam, Andrew; Zoccali, Manuela

2010-12-01

From Two Micron All Sky Survey infrared photometry, we find two red clump (RC) populations coexisting in fields toward the Galactic bulge at latitudes |b|>5fdg5, ranging over ~13° in longitude and 20° in latitude. These RC peaks indicate two stellar populations separated by ~2.3 kpc at (l, b) = (+1, - 8) the two RCs are located at 6.5 and 8.8 ± 0.2 kpc. The double-peaked RC is inconsistent with a tilted bar morphology. Most of our fields show the two RCs at roughly constant distance with longitude, also inconsistent with a tilted bar; however, an underlying bar may be present. Stellar densities in the two RCs change dramatically with longitude: on the positive longitude side the foreground RC is dominant, while the background RC dominates negative longitudes. A line connecting the maxima of the foreground and background populations is tilted to the line of sight by ~20°±4°, similar to claims for the tilt of a Galactic bar. The distance between the two RCs decreases toward the Galactic plane; seen edge-on the bulge is X-shaped, resembling some extragalactic bulges and the results of N-body simulations. The center of this X is consistent with the distance to the Galactic center, although better agreement would occur if the bulge is 2-3 Gyr younger than 47 Tuc. Our observations may be understood if the two RC populations emanate, nearly tangentially, from the Galactic bar ends, in a funnel shape. Alternatively, the X, or double funnel, may continue to the Galactic center. From the Sun, this would appear peanut/box shaped, but X-shaped when viewed tangentially.

Design of a Piezoelectric-Driven Tilt Mirror for a Fast Laser Scanner

Science.gov (United States)

Park, Jung-Ho; Lee, Hu-Seung; Lee, Jae-Hoon; Yun, So-Nam; Ham, Young-Bog; Yun, Dong-Won

2012-09-01

Recently, laser scanners have been used for laser processing such as cutting, welding, and grooving, especially in the automotive industry. The laser scanners need a high-speed driving to minimize cracks caused by thermal shock of brittle materials. Therefore, a novel laser processing system that is composed of a laser source and a piezoelectric-driven tilt mirror to control the reflection angle of the laser beam, and a stage equipped with the tilt mirror has been investigated. In this study, a piezoelectric-driven tilt mirror is designed and analyzed for scanning performance to achieve a beam spot of 30 µm, a pattern width of 1 mm, an overlap ratio of 70% of the circle area, and a scanning speed of 1 m/s. Then, structural analysis of the tilt mirror with three piezoelectric actuators is performed to determine the maximum reflection angle and resonance frequency. Finally, a prototype tilt mirror is fabricated and its basic characteristics are experimentally investigated and discussed.

Asymmetric growth of collapsed caldera by oblique subsidence during the 2000 eruption of Miyakejima, Japan

Science.gov (United States)

Geshi, Nobuo

2009-04-01

Oblique development of the ring faults reflecting the structural heterogeneities inside the volcano formed many asymmetric structures of Miyakejima 2000 AD caldera. The asymmetry includes (a) offset location of the ring faults with respect to the associated shallow magma chamber, (b) unequal outward migration of the caldera wall 600 m at the southeastern rim but only 200 m at the northwestern rim, (c) development of tilted terrace only at the southeastern caldera margin, (d) eruption sites and fumaroles being confined to the southern part of the caldera. Geophysical data, including ground deformation and seismic activity, indicates the offset of the location of the magma chamber about 2 km south of the caldera center on the surface. The ring faults propagated from the deflating magma chamber obliquely about 30 degrees toward the summit. The oblique subsidence of the cylindrical block formed a wider instable zone, particularly in the southeastern side of the ring fault that enhanced the larger outward migration of the caldera rim and also caused the formation of the outer half-ring fault bordering the tilting slope at the southern part. Ascending pass of the buoyant magma along the tilted ring faults was concentrated in the southern half of the caldera and consequently the distributions of the eruption sites and fumaroles are localized in the southern-half part of the caldera. The structure of the Miyakejima 2000 caldera with complete development of the ring faults, its high roof aspect ratio and oblique subsidence is clearly distinguishable from trapdoor-type caldera. The oblique development of the ring faults can be controlled by the mechanical contrast between the solidified conduits and surrounding fragile volcanic edifice. Asymmetric development of the Miyakejima caldera shows that the collapsed calderas are potential indicators of the heterogeneous structures inside of the volcano, particularly in the case of small-size caldera.

Numerical tilting compensation in microscopy based on wavefront sensing using transport of intensity equation method

Science.gov (United States)

Hu, Junbao; Meng, Xin; Wei, Qi; Kong, Yan; Jiang, Zhilong; Xue, Liang; Liu, Fei; Liu, Cheng; Wang, Shouyu

2018-03-01

Wide-field microscopy is commonly used for sample observations in biological research and medical diagnosis. However, the tilting error induced by the oblique location of the image recorder or the sample, as well as the inclination of the optical path often deteriorates the imaging quality. In order to eliminate the tilting in microscopy, a numerical tilting compensation technique based on wavefront sensing using transport of intensity equation method is proposed in this paper. Both the provided numerical simulations and practical experiments prove that the proposed technique not only accurately determines the tilting angle with simple setup and procedures, but also compensates the tilting error for imaging quality improvement even in the large tilting cases. Considering its simple systems and operations, as well as image quality improvement capability, it is believed the proposed method can be applied for tilting compensation in the optical microscopy.

Performance verification of focus variation and confocal microscopes measuring tilted ultra-fine surfaces

DEFF Research Database (Denmark)

Quagliotti, Danilo; Baruffi, Federico; Tosello, Guido

2016-01-01

The behaviour of two optical instruments, scilicet a laser scanning confocal microscope and a focus-variation microscope, was investigated considering measurements of tilted surfaces. The measured samples were twelve steel artefacts for mould surface finish reference, covering Sa roughness...... parameter in the range (101—103) nm. The 3D surface texture parameters considered were Sa, Sq and Sdq. The small working distance of the confocal microscope objectives influenced the measurement setup, preventing from selecting a high tilting angle. The investigation was carried out comparing measurements...... of flat surfaces (0° tilt) with measurements of 12.5° tilted surfaces. The confocal microscope results showed a high sensitivity to tilting due to the laser beam reflection on the metal surfaces. The focus variation microscope results were more robust with respect to the considered angular variation...

CITEQ creates a transformer for underground electric networks: a joint initiative by Hydro-Quebec and ABB

International Nuclear Information System (INIS)

Cordeau, P.

1997-01-01

Advances in technology regarding underground transformers was discussed. After more than 3 years of research, CITEQ (Centre d'innovation sur le transport d'energie du Quebec), a new company founded by Hydro-Quebec and ABB, is on the verge of a breakthrough with a new submersible transformer with solid insulation. This transformer was specially designed for use in underground electric networks. The new transformer is a good alternative to conventional oil transformers which have a high risk of pollution mainly due to corrosion, leaks, explosions or fires. Also, the outer shell of the new transformer is composed of composite material which will eliminate the need for maintenance. The service life of the new transformer is expected to be approximately 30 to 40 years. CITEQ is hoping that this new technology will benefit the residential sector which is powered by underground distribution networks. 1 fig

Effects of Vestibular Loss on Orthostatic Responses to Tilts in the Pitch Plane

Science.gov (United States)

Wood, Scott J.; Serrador, Jorge M.; Black, F. Owen; Rupert,Angus H.; Schlegel, Todd T.

2004-01-01

The purpose of this study was to determine the extent to which vestibular loss might impair orthostatic responses to passive tilts in the pitch plane in human subjects. Data were obtained from six subjects having chronic bilateral vestibular loss and six healthy individuals matched for age, gender, and body mass index. Vestibular loss was assessed with a comprehensive battery including dynamic posturography, vestibulo-ocular and optokinetic reflexes, vestibular evoked myogenic potentials, and ocular counterrolling. Head up tilt tests were conducted using a motorized two-axis table that allowed subjects to be tilted in the pitch plane from either a supine or prone body orientation at a slow rate (8 deg/s). The sessions consisted of three tilts, each consisting of20 min rest in a horizontal position, tilt to 80 deg upright for 10 min, and then return to the horizontal position for 5 min. The tilts were performed in darkness (supine and prone) or in light (supine only). Background music was used to mask auditory orientation cues. Autonomic measurements included beat-to-beat recordings of blood pressure (Finapres), heart rate (ECG), cerebral blood flow velocity in the middle cerebral artery (transcranial Doppler), end tidal CO2, respiratory rate and volume (Respritrace), and stroke volume (impedance cardiography). For both patients and control subjects, cerebral blood flow appeared to exhibit the most rapid adjustment following transient changes in posture. Outside of a greater cerebral hypoperfusion in patients during the later stages of tilt, responses did not differ dramatically between the vestibular loss and control subjects, or between tilts performed in light and dark room conditions. Thus, with the 'exception of cerebrovascular regulation, we conclude that orthostatic responses during slow postural tilts are not substantially impaired in humans following chronic loss of vestibular function, a result that might reflect compensation by nonvisual graviceptor

A novel method of measuring spatial rotation angle using MEMS tilt sensors

International Nuclear Information System (INIS)

Cao, Jian’an; Zhu, Xin; Zhang, Leping; Wu, Hao

2017-01-01

This paper presents a novel method of measuring spatial rotation angle with a dual-axis micro-electro-mechanical systems tilt sensor. When the sensor is randomly mounted on the surface of the rotating object, there are three unpredictable and unknown mounting position parameters: α , the sensor’s swing angle on the measuring plane; β , the angle between the rotation axis and the horizontal plane; and γ , the angle between the measuring plane and the rotation axis. Thus, the sensor’s spatial rotation model is established to describe the relationship between the measuring axis, rotation axis, and horizontal plane, and the corresponding analytical equations are derived. Furthermore, to eliminate the deviation caused by the uncertain direction of the rotation axis, an extra perpendicularly mounted, single-axis tilt sensor is combined with the dual-axis tilt sensor, forming a three-axis tilt sensor. Then, by measuring the sensors’ three tilts and solving the model’s equations, the object’s spatial rotation angle is obtained. Finally, experimental results show that the developed tilt sensor is capable of measuring spatial rotation angle in the range of  ±180° with an accuracy of 0.2° if the angle between the rotation axis and the horizontal plane is less than 75°. (paper)

TX 2000: total reflection and 45o energy dispersive x-ray fluorescence spectrometer

International Nuclear Information System (INIS)

Pasti, F.; Torboli, A.; Valdes, M.

2000-01-01

This equipment, developed by Ital Structures, combines two kinds of energy dispersive X-ray fluorescence techniques, the first using total reflection geometry and the second conventional 45 o geometry. The equipment is completely controlled by a PC and to reach the condition of total reflection is very easy because it is enough to load the file with the right position for the corresponding energy. In this apparatus we used an x-ray tube with an alloy anode of Mo/W with a long fine focus at 2200 W. To monochromatize the x-ray beam while choosing, for example, the Mo K alpha or W L alpha or a piece of white spectrum of 33 keV, we use a highly reflective multilayer made of Si/W with 2d = 45.5 A o . The detector used in the equipment is a lithium drifted silicon detector (Si(Li)) with an excellent energy resolution of 135 eV at 5.9 keV and 1000 cps. We developed two programs written in Windows 95, 98 and NT for a 32 bit microprocessor. The first one is called TYACQ32 and has the following functions: first, complete control of the hardware, second automatic alignment of the TX 2000 spectrometer and third acquisition of spectra. The second program is EDXRF32. This is a program to accomplish spectrum and quantitative analysis for TXRF and EDXRF 45 o degrees analysis. (author)

A combined stretching-tilting mechanism produces negative, zero and positive linear thermal expansion in a semi-flexible Cd(II)-MOF.

Science.gov (United States)

Lama, Prem; Das, Raj Kumar; Smith, Vincent J; Barbour, Leonard J

2014-06-21

A novel semi-flexible Cd(II)-MOF has been synthesized and characterized by variable temperature powder and single-crystal X-ray diffraction. The material displays an unusual combination of thermal expansion (TE) i.e. negative, zero and positive, which is an extremely rare finding, especially for metal-organic frameworks as a result of a combined stretching-tilting mechanism.

Monitoring of Cyclic Steam Stimulation by Inversion of Surface Tilt Measurements

Science.gov (United States)

Maharramov, M.; Zoback, M. D.

2014-12-01

Temperature and pressure changes associated with the cyclic steam simulation (CSS) used in heavy oil production from sands are accompanied by significant deformation. Inversion of geomechanical data may provide a potentially powerful reservoir monitoring tool where geomechanical effects are significant. Induced pore pressure changes can be inverted from measurable surface deformations by solving an inverse problem of poroelasticity. In this work, we apply this approach to estimating pore pressure changes from surface tilt measurements at a heavy oil reservoir undergoing cyclic steam simulation. Steam was injected from November 2007 through January 2008. Surface tilt measurements were collected from 25 surface tilt stations during this period. The injection ran in two overlapping phases: Phase 1 ran from the beginning of the injection though mid-December, and Phase 2 overlapped with Phase 1 and ran through the beginning of January. During Phase 1 steam was injected in the western part of the reservoir, followed by injection in the eastern part in Phase 2. The pore pressure evolution was inverted from daily tilt measurements using regularized constrained least squares fitting, the results are shown on the plot. Estimated induced pore pressure change (color scale), observed daily incremental tilts (green arrows) and modeled daily incremental tilts (red arrows) are shown in three panels corresponding to two and five weeks of injection, and the end of injection period. DGPS measurements available for a single location were used as an additional inversion constraint. The results indicate that the pore pressure increase in the reservoir follows the same pattern as the steam injection, from west to east. This qualitative behaviour is independent of the amount of regularization, indirectly validating our inversion approach. Patches of lower pressure appear to be stable with regard to regularization and may provide valuable insight into the efficiency of steam injection

Tilted Bianchi type I dust fluid cosmological model in general relativity

Indian Academy of Sciences (India)

Tilted Bianchi type I dust fluid cosmological model in general relativity ... In this paper, we have investigated a tilted Bianchi type I cosmological model filled with dust of perfect fluid in general relativity. ... Pramana – Journal of Physics | News ...

Combined Influence of Visual Scene and Body Tilt on Arm Pointing Movements: Gravity Matters!

Science.gov (United States)

Scotto Di Cesare, Cécile; Sarlegna, Fabrice R.; Bourdin, Christophe; Mestre, Daniel R.; Bringoux, Lionel

2014-01-01

Performing accurate actions such as goal-directed arm movements requires taking into account visual and body orientation cues to localize the target in space and produce appropriate reaching motor commands. We experimentally tilted the body and/or the visual scene to investigate how visual and body orientation cues are combined for the control of unseen arm movements. Subjects were asked to point toward a visual target using an upward movement during slow body and/or visual scene tilts. When the scene was tilted, final pointing errors varied as a function of the direction of the scene tilt (forward or backward). Actual forward body tilt resulted in systematic target undershoots, suggesting that the brain may have overcompensated for the biomechanical movement facilitation arising from body tilt. Combined body and visual scene tilts also affected final pointing errors according to the orientation of the visual scene. The data were further analysed using either a body-centered or a gravity-centered reference frame to encode visual scene orientation with simple additive models (i.e., ‘combined’ tilts equal to the sum of ‘single’ tilts). We found that the body-centered model could account only for some of the data regarding kinematic parameters and final errors. In contrast, the gravity-centered modeling in which the body and visual scene orientations were referred to vertical could explain all of these data. Therefore, our findings suggest that the brain uses gravity, thanks to its invariant properties, as a reference for the combination of visual and non-visual cues. PMID:24925371

Inner Core Tilt and Polar Motion: Probing the Dynamics Deep Inside the Earth

Science.gov (United States)

Dumberry, M.; Bloxham, J.

2003-12-01

A tilted inner core permits exchange of angular momentum between the core and the mantle through gravitational and pressure torques and, as a result, changes in the direction of Earth's axis of rotation with respect to the mantle. Some of the observed variations in the direction of Earth's rotation could then be caused by equatorial torques on the inner core which tilt the latter out of its alignment with the mantle. In this work, we investigate whether such a scenario could explain the decade polar motion known as the Markowitz wobble. We show that a decade polar motion of the same amplitude as the observed Markowitz wobble requires a torque of 1020 N m which tilts the inner core by 0.07 degrees. This result critically depends on the viscosity of the inner core; for a viscosity less than 5 x 1017 Pa s, larger torques are required. A torque of 1020 N m with decadal periodicity can perhaps be produced by electromagnetic coupling between the inner core and a component of the flow in the outer core known as torsional oscillations, provided that the radial magnetic field at the inner core boundary is on the order of 3 to 4 mT and satisfies certain geometrical constraints. The resulting polar motion thus produced is eccentric and polarized, in agreement with the observations. Our model suggests that equatorial torques at the inner core boundary might also excite the Chandler wobble, provided shorter wavelength torsional oscillations with higher natural frequencies have enough power or provided there exists another physical mechanism that can generate a large torque at a 14 month period.

Edge detection of magnetic anomalies using analytic signal of tilt angle (ASTA)

Science.gov (United States)

Alamdar, K.; Ansari, A. H.; Ghorbani, A.

2009-04-01

Magnetic is a commonly used geophysical technique to identify and image potential subsurface targets. Interpretation of magnetic anomalies is a complex process due to the superposition of multiple magnetic sources, presence of geologic and cultural noise and acquisition and positioning error. Both the vertical and horizontal derivatives of potential field data are useful; horizontal derivative, enhance edges whereas vertical derivative narrow the width of anomaly and so locate source bodies more accurately. We can combine vertical and horizontal derivative of magnetic field to achieve analytic signal which is independent to body magnetization direction and maximum value of this lies over edges of body directly. Tilt angle filter is phased-base filter and is defined as angle between vertical derivative and total horizontal derivative. Tilt angle value differ from +90 degree to -90 degree and its zero value lies over body edge. One of disadvantage of this filter is when encountering with deep sources the detected edge is blurred. For overcome this problem many authors introduced new filters such as total horizontal derivative of tilt angle or vertical derivative of tilt angle which Because of using high-order derivative in these filters results may be too noisy. If we combine analytic signal and tilt angle, a new filter termed (ASTA) is produced which its maximum value lies directly over body edge and is easer than tilt angle to delineate body edge and no complicity of tilt angle. In this work new filter has been demonstrated on magnetic data from an area in Sar- Cheshme region in Iran. This area is located in 55 degree longitude and 32 degree latitude and is a copper potential region. The main formation in this area is Andesith and Trachyandezite. Magnetic surveying was employed to separate the boundaries of Andezite and Trachyandezite from adjacent area. In this regard a variety of filters such as analytic signal, tilt angle and ASTA filter have been applied which

Twenty-degree-tilt radiography for evaluation of lateral humeral condylar fracture in children

International Nuclear Information System (INIS)

Imada, Hideaki; Tanaka, Ryuji; Itoh, Yohei; Kishi, Kazuhiko

2010-01-01

To investigate the efficacy of '20 -tilt anteroposterior (A-P) radiography' in the assessment of lateral condylar fractures of the distal humerus. Eighteen children with lateral humeral condylar fractures were studied. Every child underwent conventional A-P and lateral radiography, and six children underwent multi-detector computed tomography (MDCT). For the investigation of 20 -tilt radiography, ten children with lateral humeral condylar fractures had conventional and 20 -tilt A-P and lateral radiography both preoperatively and postoperatively. Fragment dislocation was measured at the lateral and medial margins of the fracture on both the conventional A-P and 20 -tilt A-P radiographs. The lateral condylar fragment was triangular and was most prominent posteriorly. The fracture line was typically tilted approximately 20 to a reference line perpendicular to the long axis of the humerus in the lateral view. The extent of dislocation at the lateral and medial margins of the fracture site by 20 -tilt A-P radiography (9.3 ± 3.6 mm and 5.6 ± 2.5 mm) was significantly wider than that measured by the conventional method (6.8 ± 4.1 mm and 2.0 ± 1.5 mm), which may influence treatment. Twenty-degree-tilt A-P radiography may more precisely demonstrate fragment dislocation than standard radiographs and may influence patient treatment. (orig.)

Early Poststroke Rehabilitation Using a Robotic Tilt-Table Stepper and Functional Electrical Stimulation

Directory of Open Access Journals (Sweden)

Alexey N. Kuznetsov

2013-01-01

Full Text Available Background. Stroke frequently leaves survivors with hemiparesis. To prevent persistent deficits, rehabilitation may be more effective if started early. Early training is often limited because of orthostatic reactions. Tilt-table stepping robots and functional electrical stimulation (FES may prevent these reactions. Objective. This controlled convenience sample study compares safety and feasibility of robotic tilt-table training plus FES (ROBO-FES and robotic tilt-table training (ROBO against tilt-table training alone (control. A preliminary assessment of efficacy is performed. Methods. Hemiparetic ischemic stroke survivors (age years, days after stroke were assigned to 30 days of ROBO-FES (, ROBO (, or control ( in addition to conventional physical therapy. Impedance cardiography and transcranial doppler sonography were performed before, during, and after training. Hemiparesis was assessed using the British Medical Research Council (MRC strength scale. Results. No serious adverse events occurred; 8 patients in the tilt-table group prematurely quit the study because of orthostatic reactions. Blood pressure and CBFV dipped % during robot training. In 52% of controls mean arterial pressure decreased by %. ROBO-FES increased leg strength by points, ROBO by more than control (, . CBFV increased in both robotic groups more than in controls (. Conclusions. Robotic tilt-table exercise with or without FES is safe and may be more effective in improving leg strength and cerebral blood flow than tilt table alone.

A combined arc-melting and tilt-casting furnace for the manufacture of high-purity bulk metallic glass materials.

Science.gov (United States)

Soinila, E; Pihlajamäki, T; Bossuyt, S; Hänninen, H

2011-07-01

An arc-melting furnace which includes a tilt-casting facility was designed and built, for the purpose of producing bulk metallic glass specimens. Tilt-casting was chosen because reportedly, in combination with high-purity processing, it produces the best fatigue endurance in Zr-based bulk metallic glasses. Incorporating the alloying and casting facilities in a single piece of equipment reduces the amount of laboratory space and capital investment needed. Eliminating the sample transfer step from the production process also saves time and reduces sample contamination. This is important because the glass forming ability in many alloy systems, such as Zr-based glass-forming alloys, deteriorates rapidly with increasing oxygen content of the specimen. The challenge was to create a versatile instrument, in which high purity conditions can be maintained throughout the process, even when melting alloys with high affinity for oxygen. Therefore, the design provides a high-vacuum chamber to be filled with a low-oxygen inert atmosphere, and takes special care to keep the system hermetically sealed throughout the process. In particular, movements of the arc-melting electrode and sample manipulator arm are accommodated by deformable metal bellows, rather than sliding O-ring seals, and the whole furnace is tilted for tilt-casting. This performance of the furnace is demonstrated by alloying and casting Zr(55)Cu(30)Al(10)Ni(5) directly into rods up to ø 10 mm which are verified to be amorphous by x-ray diffraction and differential scanning calorimetry, and to exhibit locally ductile fracture at liquid nitrogen temperature.

[Evaluation of psychological fear in children undergoing head-up tilt test].

Science.gov (United States)

Chu, Wei-Hong; Wu, Li-Jia; Wang, Cheng; Lin, Ping; Li, Fang; Zhu, Li-Ping; Ran, Jing; Zou, Run-Mei; Liu, De-Yu

2014-03-01

To investigate the effects of different tilt angles of head-up tilt test (HUTT) and different responses to HUTT on the psychological fear in children undergoing the test. HUTT was performed on children with unexplained syncope or pre-syncope (107 cases: 52 males and 55 females), aged 5.5-17.8 years (mean 12.0±2.8 years). All subjects were randomly assigned to undergo HUTT at an angle of 60°, 70° or 80°; the negative cases underwent sublingual nitroglycerin-provocation HUTT at the same tilt angle. The Wong-Baker Faces Pain Rating Scale was used for self-assessment of psychological fear in subjects during HUTT at the end point of the test. The positive rate, hemodynamic changes and distribution of response types showed no significant differences between children at tilt angles of 60°, 70° and 80° (P>0.05). The greater the tilt angle, the higher the degree of psychological fear in children undergoing the test, but there were no significant differences between them (P>0.05). The degree of psychological fear in children who showed a positive response to HUTT (n=76) was significantly higher than that in children who showed a negative response (n=31) (Pfear in children undergoing the test, and the degree of psychological fear increases in children tested at tilt angles from 60° to 80°, but the differences have no statistical significance. A positive response to HUTT can significantly increase the psychological fear in children.

Coherent field propagation between tilted planes.

Science.gov (United States)

Stock, Johannes; Worku, Norman Girma; Gross, Herbert

2017-10-01

Propagating electromagnetic light fields between nonparallel planes is of special importance, e.g., within the design of novel computer-generated holograms or the simulation of optical systems. In contrast to the extensively discussed evaluation between parallel planes, the diffraction-based propagation of light onto a tilted plane is more burdensome, since discrete fast Fourier transforms cannot be applied directly. In this work, we propose a quasi-fast algorithm (O(N 3  log N)) that deals with this problem. Based on a proper decomposition into three rotations, the vectorial field distribution is calculated on a tilted plane using the spectrum of plane waves. The algorithm works on equidistant grids, so neither nonuniform Fourier transforms nor an explicit complex interpolation is necessary. The proposed algorithm is discussed in detail and applied to several examples of practical interest.

3D single-molecule super-resolution microscopy with a tilted light sheet.

Science.gov (United States)

Gustavsson, Anna-Karin; Petrov, Petar N; Lee, Maurice Y; Shechtman, Yoav; Moerner, W E

2018-01-09

Tilted light sheet microscopy with 3D point spread functions (TILT3D) combines a novel, tilted light sheet illumination strategy with long axial range point spread functions (PSFs) for low-background, 3D super-localization of single molecules as well as 3D super-resolution imaging in thick cells. Because the axial positions of the single emitters are encoded in the shape of each single-molecule image rather than in the position or thickness of the light sheet, the light sheet need not be extremely thin. TILT3D is built upon a standard inverted microscope and has minimal custom parts. The result is simple and flexible 3D super-resolution imaging with tens of nm localization precision throughout thick mammalian cells. We validate TILT3D for 3D super-resolution imaging in mammalian cells by imaging mitochondria and the full nuclear lamina using the double-helix PSF for single-molecule detection and the recently developed tetrapod PSFs for fiducial bead tracking and live axial drift correction.

Monitoring of radiation exposure. Annual report 2000

International Nuclear Information System (INIS)

Rantanen, E.

2001-03-01

At the end of 2000, there were 1,779 valid safety licenses in Finland for the use of radiation. In addition, there were 2,038 responsible parties for dental x-ray diagnostics. The registry Radiation and Nuclear Safety Authority (STUK) listed 13,754 radiation sources and 270 radionuclide laboratories. In the year 2000 360 inspections were made concerning the safety licences and 53 concerning dental x-ray diagnostics. The import of radioactive substances amounted to 175,836 GBq and export to 74,420 GBq. Short-lived radionuclides produced in Finland amounted to 55,527 GBq. In the year 2000 there were 10,846 workers monitored for radiation exposure at 1,171 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The annual effective dose limit was not exceeded. The total dose recorded in the dose registry(sum of the individual dosemeter readings) was 6.5 Sv in 2000

LULI 2000 activity report; LULI rapport annuel 2000

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This document gathers the main results obtained by scientists from the LULI (laboratory for the use of intense lasers) unit in 2000. It is made up of 58 short articles and is organized into 6 topics: 1) laser-matter interaction, 2) hydrodynamics, shocks, equations of state, 3) atom physics, X-ray lasers, 4) material treatment, 5) progress in optics for power lasers, and 6) instrumentation and other advances.

TWO RED CLUMPS AND THE X-SHAPED MILKY WAY BULGE

International Nuclear Information System (INIS)

McWilliam, Andrew; Zoccali, Manuela

2010-01-01

From Two Micron All Sky Survey infrared photometry, we find two red clump (RC) populations coexisting in fields toward the Galactic bulge at latitudes |b|>5. 0 5, ranging over ∼13 0 in longitude and 20 0 in latitude. These RC peaks indicate two stellar populations separated by ∼2.3 kpc; at (l, b) = (+1, - 8) the two RCs are located at 6.5 and 8.8 ± 0.2 kpc. The double-peaked RC is inconsistent with a tilted bar morphology. Most of our fields show the two RCs at roughly constant distance with longitude, also inconsistent with a tilted bar; however, an underlying bar may be present. Stellar densities in the two RCs change dramatically with longitude: on the positive longitude side the foreground RC is dominant, while the background RC dominates negative longitudes. A line connecting the maxima of the foreground and background populations is tilted to the line of sight by ∼20 0 ±4 0 , similar to claims for the tilt of a Galactic bar. The distance between the two RCs decreases toward the Galactic plane; seen edge-on the bulge is X-shaped, resembling some extragalactic bulges and the results of N-body simulations. The center of this X is consistent with the distance to the Galactic center, although better agreement would occur if the bulge is 2-3 Gyr younger than 47 Tuc. Our observations may be understood if the two RC populations emanate, nearly tangentially, from the Galactic bar ends, in a funnel shape. Alternatively, the X, or double funnel, may continue to the Galactic center. From the Sun, this would appear peanut/box shaped, but X-shaped when viewed tangentially.

The Application of Normal Stress Reduction Function in Tilt Tests for Different Block Shapes

Science.gov (United States)

Kim, Dong Hyun; Gratchev, Ivan; Hein, Maw; Balasubramaniam, Arumugam

2016-08-01

This paper focuses on the influence of the shapes of rock cores, which control the sliding or toppling behaviours in tilt tests for the estimation of rock joint roughness coefficients (JRC). When the JRC values are estimated by performing tilt tests, the values are directly proportional to the basic friction of the rock material and the applied normal stress on the sliding planes. Normal stress obviously varies with the shape of the sliding block, and the basic friction angle is also affected by the sample shapes in tilt tests. In this study, the shapes of core blocks are classified into three representative shapes and those are created using plaster. Using the various shaped artificial cores, a set of tilt tests is carried out to identify the shape influences on the normal stress and the basic friction angle in tilt tests. The test results propose a normal stress reduction function to estimate the normal stress for tilt tests according to the sample shapes based on Barton's empirical equation. The proposed normal stress reduction functions are verified by tilt tests using artificial plaster joints and real rock joint sets. The plaster joint sets are well matched and cast in detailed printed moulds using a 3D printing technique. With the application of the functions, the obtained JRC values from the tilt tests using the plaster samples and the natural rock samples are distributed within a reasonable JRC range when compared with the measured values.

Characterization of X-ray irradiator RS-2000; Caracterizacao do irradiador de raios X RS-2000

Energy Technology Data Exchange (ETDEWEB)

Mazaro, Sarah Jessica; Pavoni, Juliana Fernandes [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Departamento de Fisica; Silva, Maelson do Nascimento; Bianchini, Adriano L.B.; Amaral, Leonardo Lira do, E-mail: sarahmazaro@yahoo.com.br [Universidade de Sao Paulo (HC/FMRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Faculdade de Medicina. Servico de Radioterapia

2014-04-15

Gamma irradiators are being replaced by the x - rays ones which are more economical and have greater safety benefits compared to the radionuclide irradiators. Some tests are usually performed to ensure quality control while working with radiation, as constancy, linearity, repeatability, reproducibility, radiometric survey and security tests. Evaluating the technical parameters and the instrument and equipment performance quickly. The irradiator characterization determines its operation, by ensuring that the deposited dose is the one desired. This study aims to characterize x-rays irradiators through dosimetric tests. The equipment used in this study stable in dose rate free space and regularity for safety test. Furthermore, the measurements were reproducible with a maximum variation of 10% and the radiometric survey showed that the results are consistent with the exemption requirements of radiological protection described in regulatory position 3.01/001:2011. (author)

Comparison of optimum tilt angles of solar collectors determined at yearly, seasonal and monthly levels

International Nuclear Information System (INIS)

Despotovic, Milan; Nedic, Vladimir

2015-01-01

Highlights: • Optimum yearly, biannual, seasonal, monthly, and daily tilt angles were found. • Energy collected per square meter is compared for ten different scenarios. • Four seasonal scenarios and two biannual scenarios were considered. • It is sufficient to adjust tilt angles only twice per year. - Abstract: The amount of energy that is transformed in solar collector depends on its tilt angle with respect to horizontal plane and orientation of the collector. In this article the optimum tilt angle of solar collectors for Belgrade, which is located at the latitude of 44°47′N is determined. The optimum tilt angle was found by searching for the values for which the solar radiation on the collector surface is maximum for a particular day or a specific period. In that manner the yearly, biannual, seasonal, monthly, fortnightly, and daily optimum tilt angles are determined. Annually collected energy per square meter of tilted surface is compared for ten different scenarios. In addition, these optimum tilt angles are used to calculate the amount of energy on the surface of PV panels that could be installed at the roof of the building. The results show that for observed case study placing the panels at yearly, seasonal and monthly optimum tilt angles, would yield increasing yearly amount of collected energy by factor of 5.98%, 13.55%, and 15.42% respectively compared to energy that could be collected by putting the panels at current roofs’ surface angles

Incidencia de Chrysobothris sp. en cedro (Cedrela odorata) y caoba (Swietenia humilis) con o sin asocio a guineo (Musa balbissiana ABB) en Rivas, Nicaragua

OpenAIRE

Sequeira, N Yilber; Bustos-Pérez, Irnan; González-Martínez, Álvaro José; Chavarría-Ñamendi, Francisco José

2016-01-01

Se analizó la incidencia de Chrysobothris sp. en cedro (Cedrela odorata) y caoba (Swietenia humilis) durante el periodo entre febrero a noviembre de 2014 bajo un Sistema Agroforestal “Taungya” en el departamento de Rivas, Nicaragua. No se encontraron diferencias estadísticas significativas de Chrysobothris sp. en cedro y caoba asociados o no asociados a guineo (Musa balbissiana ABB). La preferencia de Chrysobothris sp. fue tres veces mayor en cedro que caoba. El daño de la larva en el tallo p...

Use of an Android application "clinometer" for measurement of head down tilt given during subarachnoid block.

Science.gov (United States)

Dixit, R B; Neema, M M

2016-01-01

Head down tilt is given to patients after sub arachnoid block for adjustment of height of block. However, the amount of tilt given is subjective and cannot be documented. We used an android application named "clinometer" to measure exact degree of tilt given by anesthesiologists as their routine practice. This observational study, at a medical college hospital, was done in 130 patients given sub arachnoid block for lower abdominal surgeries. We observed and documented vital data of patients and measured tilt given by application "clinometer." We observed that the application was easy to use and measured tilt each time. The result obtained can be documented, digitally saved and transferred. In 130 patients studied, we observed incidence of degree of tilt as follows: 6-8° tilt in 38 patients (29.23%), 8-10 in 36 patients (27.69%), 10-12 in 30 patients (23.08%), 12-14 in 12 patients (9.23%) and 14-16° tilt in 14 patients (10.77%). Use of application was received with enthusiasm by practicing anesthesiologists. Various possible uses of this application are discussed.

Octahedral tilt transitions in the relaxor ferroelectric Na1/2Bi1/2TiO3

International Nuclear Information System (INIS)

Meyer, Kai-Christian; Gröting, Melanie; Albe, Karsten

2015-01-01

The kinetics of octahedral tilt transitions in the lead-free relaxor material sodium bismuth titanate Na 1/2 Bi 1/2 TiO 3 (NBT) is investigated by electronic structure calculations within density functional theory. Energy barriers for transitions between tetragonal, rhombohedral and orthorhombic tilts in cation configurations with [001]- and [111]-order on the A-sites are determined by nudged elastic band calculations. By tilting entire layers of octahedra simultaneously we find that the activation energy is lower for structures with 001-order compared to such with 111-order. The energetic coupling between differently tilted layers is, however, negligibly small. By introducing a single octahedral defect we create local tilt disorder and find that the deformation energy of the neighboring octahedra is less in a rhombohedral than in a tetragonal structure. By successively increasing the size of clusters of orthorhombic defects in a rhombohedral matrix with 001-order, we determine a critical cluster size of about 40 Å . Thus groups of about ten octahedra can be considered as nuclei for polar nanoregions, which are the cause of the experimentally observed relaxor behavior of NBT. - Graphical abstract: Nine orthorhombic oxygen octahedral tilt defects in a rhombohedral tilt configuration. - Highlights: • Chemical order influences energy barriers of octahedral tilt transitions. • The octahedral deformation energy is lower in rhombohedral phases. • Tilt defect clusters are more likely in rhombohedral structures. • Tilt defect clusters can act as nuclei for polar nanoregions

Reducing friction in tilting-pad bearings by the use of enclosed recesses

DEFF Research Database (Denmark)

Heinrichson, Niels; Santos, Ilmar

2008-01-01

A three-dimensional thermoelastohydrodynamic model is applied to the analysis of tilting-pad bearings with spherical pivots and equipped with deep recesses in the high-pressure regions. A potential for a 10-20% reduction in the friction loss compared to conventional plain bearing pads is documented....... Design suggestions minimizing the power loss are given for various length-to-width ratios. The tilting angle in the sliding direction is more sensitive to correct positioning of the pivot point than conventional bearing pads. Improving the performance by equipping a tilting-pad bearing with a deep recess...... therefore requires accurate analysis and design of the bearing. Similarly, a high sensitivity perpendicular to the sliding direction suggests that this method of reducing friction is more feasible when using line pivots or spring beds than when using spherical pivots for controlling the tilting angle....

Tilt Precursors before Earthquakes on the San Andreas Fault, California.

Science.gov (United States)

Johnston, M J; Mortensen, C E

1974-12-13

An array of 14 biaxial shallow-borehole tiltmeters (at 1O(-7) radian sensitivity) has been installed along 85 kilometers of the San Andreas fault during the past year. Earthquake-related changes in tilt have been simultaneously observed on up to four independent instruments. At earthquake distances greater than 10 earthquake source dimensions, there are few clear indications of tilt change. For the four instruments with the longest records (> 10 months), 26 earthquakes have occurred since July 1973 with at least one instrument closer than 10 source dimensions and 8 earthquakes with more than one instrument within that distance. Precursors in tilt direction have been observed before more than 10 earthquakes or groups of earthquakes, and no similar effect has yet been seen without the occurrence of an earthquake.

The anterior tilt of the acromion: radiographic evaluation and correlation with shoulder diseases

International Nuclear Information System (INIS)

Prato, N.; Peloso, D.; Franconeri, A.; Tegaldo, G.; Ravera, G.B.; Silvestri, E.; Derchi, L.E.

1998-01-01

The aim of this study was to test whether the anterior tilt of the acromion can be objectively evaluated on lateral radiographs, and whether there is a relation between this anatomical feature and the most common shoulder diseases. Lateral radiographs of 15 dried scapulas were performed in neutral position and with 5 of caudal, cranial, anterior and posterior angulations. Two hundred and forty-three shoulders, both asymptomatic and affected by chronic and post-traumatic impingement, calcific tendinitis and instability, were examined by conventional radiography. The presence of rotator-cuff tears was investigated by sonography. A method was elaborated to obtain reproducible lateral radiographs and to determine the acromial tilt angle. Inter- and intraobserver and inter- and intraoperator variations in measurements were evaluated. Variations in tube angulation produced changes in tilt-angle values on dried scapulas. The average tilt angle for the chronic impingement and the instability groups were significantly different from the post-traumatic, calcific tendinitis and control groups. Rotator-cuff tears were significantly more frequent in the chronic impingement group and related to a more acute tilt angle. The inter- and intraobserver variability coefficients were 0.95 and 0.98, whereas the inter- and intraoperator variability coefficients were 0.94 and 0.96, respectively. Conventional radiography using fluoroscopy for positioning is a well-reproducible method for the evaluation of acromial tilt. There is a significant difference in tilt-angle values between some groups of subjects examined, but the lack of specificity limits the clinical importance of such measurement. (orig.)

The anterior tilt of the acromion: radiographic evaluation and correlation with shoulder diseases

Energy Technology Data Exchange (ETDEWEB)

Prato, N.; Peloso, D.; Franconeri, A. [Department of Radiology, San Carlo Hospital, Genoa (Italy); Tegaldo, G. [Dept. of Orthopaedic Surgery, San Carlo Hospital, Genoa (Italy); Ravera, G.B. [Inst. of Medical Statistics and Biometry, University of Genoa (Italy); Silvestri, E.; Derchi, L.E. [Inst. of Radiology, University of Genoa (Italy)

1998-12-01

The aim of this study was to test whether the anterior tilt of the acromion can be objectively evaluated on lateral radiographs, and whether there is a relation between this anatomical feature and the most common shoulder diseases. Lateral radiographs of 15 dried scapulas were performed in neutral position and with 5 of caudal, cranial, anterior and posterior angulations. Two hundred and forty-three shoulders, both asymptomatic and affected by chronic and post-traumatic impingement, calcific tendinitis and instability, were examined by conventional radiography. The presence of rotator-cuff tears was investigated by sonography. A method was elaborated to obtain reproducible lateral radiographs and to determine the acromial tilt angle. Inter- and intraobserver and inter- and intraoperator variations in measurements were evaluated. Variations in tube angulation produced changes in tilt-angle values on dried scapulas. The average tilt angle for the chronic impingement and the instability groups were significantly different from the post-traumatic, calcific tendinitis and control groups. Rotator-cuff tears were significantly more frequent in the chronic impingement group and related to a more acute tilt angle. The inter- and intraobserver variability coefficients were 0.95 and 0.98, whereas the inter- and intraoperator variability coefficients were 0.94 and 0.96, respectively. Conventional radiography using fluoroscopy for positioning is a well-reproducible method for the evaluation of acromial tilt. There is a significant difference in tilt-angle values between some groups of subjects examined, but the lack of specificity limits the clinical importance of such measurement. (orig.) With 6 figs., 3 tabs., 34 refs.

Analysis of fixed tilt and sun tracking photovoltaic–micro wind based hybrid power systems

International Nuclear Information System (INIS)

Sinha, Sunanda; Chandel, S.S.

2016-01-01

Graphical abstract: 6 kW_p photovoltaic–micro wind based hybrid power system analysis in a Indian Western Himalayan location. - Highlights: • Power generation by a roof mounted photovoltaic–micro wind hybrid system is explored. • Optimum hybrid configurations using fixed and sun tracking photovoltaic systems are determined. • Analysis of hybrid systems with optimally tilted and different sun tracking systems is presented. • Two axis sun tracking systems are found to generate 4.88–26.29% more energy than fixed tilt system. • Hybrid system installed at optimum tilt angle is found to be cost effective than a sun tracking system. - Abstract: In this study fixed tilt and sun tracking photovoltaic based micro wind hybrid power systems are analyzed along with determining the optimum configurations for a 6 kW_p roof mounted micro wind based hybrid system using fixed and tracking photovoltaic systems to enhance the power generation potential in a low windy Indian hilly terrain with good solar resource. The main objective of the study is to enhance power generation by focusing on photovoltaic component of the hybrid system. A comparative power generation analysis of different configurations of hybrid systems with fixed tilt, monthly optimum tilt, yearly optimum tilt and 6 different sun tracking photovoltaic systems is carried out using Hybrid Optimization Model for Electric Renewables. Monthly and seasonal optimum tilt angles determined for the location vary between 0° and 60° with annual optimum tilt angle as 29.25°. The optimum configurations for all sun tracking systems except for the two axis tracking system is found to be 7 kW_p photovoltaic system, one 5 kW_p wind turbine, 10 batteries and a 2 kW_p inverter. The optimum configuration for two axis tracking system and two types of fixed tilt systems, is found to be a 8 kW_p photovoltaic system, one 5 kW_p wind turbine, 10 batteries and a 2 kW_p inverter. The results show that horizontal axis with

Tilt stability in nonlinear programming under Mangasarian-Fromovitz constraint qualification

Czech Academy of Sciences Publication Activity Database

Mordukhovich, B. S.; Outrata, Jiří

2013-01-01

Roč. 49, č. 3 (2013), s. 446-464 ISSN 0023-5954 R&D Projects: GA ČR(CZ) GAP201/12/0671 Institutional support: RVO:67985556 Keywords : variational analysis * second-order theory * generalized differentiation * tilt stability Subject RIV: BA - General Mathematics Impact factor: 0.563, year: 2013 http://library.utia.cas.cz/separaty/2013/MTR/outrata-tilt stability in nonlinear programming under mangasarian-fromovitz constraint qualification.pdf

Research on Calculation of the IOL Tilt and Decentration Based on Surface Fitting

OpenAIRE

Li, Lin; Wang, Ke; Yan, Yan; Song, Xudong; Liu, Zhicheng

2013-01-01

The tilt and decentration of intraocular lens (IOL) result in defocussing, astigmatism, and wavefront aberration after operation. The objective is to give a method to estimate the tilt and decentration of IOL more accurately. Based on AS-OCT images of twelve eyes from eight cases with subluxation lens after operation, we fitted spherical equation to the data obtained from the images of the anterior and posterior surfaces of the IOL. By the established relationship between IOL tilt (decentrati...

Impaired perception of surface tilt in progressive supranuclear palsy.

Directory of Open Access Journals (Sweden)

Marian L Dale

Full Text Available Progressive supranuclear palsy (PSP is characterized by early postural instability and backward falls. The mechanisms underlying backward postural instability in PSP are not understood. The aim of this study was to test the hypothesis that postural instability in PSP is a result of dysfunction in the perception of postural verticality.We gathered posturography data on 12 subjects with PSP to compare with 12 subjects with idiopathic Parkinson's Disease (PD and 12 healthy subjects. Objective tests of postural impairment included: dynamic sensory perception tests of gravity and of surface oscillations, postural responses to surface perturbations, the sensory organization test of postural sway under altered sensory conditions and limits of stability in stance.Perception of toes up (but not toes down surface tilt was reduced in subjects with PSP compared to both control subjects (p≤0.001 standing, p≤0.007 seated and subjects with PD (p≤0.03 standing, p≤0.04 seated. Subjects with PSP, PD and normal controls accurately perceived the direction of gravity when standing on a tilting surface. Unlike PD and control subjects, subjects with PSP exerted less postural corrective torque in response to toes up surface tilts.Difficulty perceiving backward tilt of the surface or body may account for backward falls and postural impairments in patients with PSP. These observations suggest that abnormal central integration of sensory inputs for perception of body and surface orientation contributes to the pathophysiology of postural instability in PSP.

Synthesis, characterization and electro-optic properties of novel siloxane liquid crystalline with a large tilt angle

International Nuclear Information System (INIS)

Liao, Chien-Tung; Lee, Jiunn-Yih; Lai, Chiu-Chun

2011-01-01

Research highlights: → In this study we report the synthesis and characterization of new ferroelectric liquid crystal material. → We examined the influence of the addition of a trisiloxane end-group on one side-chain of an achiral alkyl chain on the phase transition. → Finally, the properties of the chiral smectic C (SmC*) phase were measured for target compounds. - Abstract: This paper presents a study of the ferroelectric behavior in low molar mass organosiloxane liquid crystal materials. A few novel series of compounds with a large tilt angle were synthesized, and the mesophases exhibited were compared. The mesophases under discussion were investigated by means of polarizing microscopy (POM), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and electro-optical experiments. The influence of the molecular structure on the occurrence of the chiral smectic C (SmC*) phase was investigated. Finally, the electro-optical properties of the SmC* phase, such as tilt angle, dielectric permittivity and switching behavior were also measured. As a consequence, the correlation between the electro-optical properties and chemical structures of these compounds was investigated.

Analysis of a ferrofluid core differential transformer tilt measurement sensor

Energy Technology Data Exchange (ETDEWEB)

Medvegy, T.; Molnár, Á.; Molnár, G.; Gugolya, Z.

2017-04-15

In our work, we developed a ferrofluid core differential transformer sensor, which can be used to measure tilt and acceleration. The proposed sensor consisted of three coils, from which the primary was excited with an alternating current. In the space surrounded by the coils was a cell half-filled with ferrofluid, therefore in the horizontal state of the sensor the fluid distributes equally in the three sections of the cell surrounded by the three coils. Nevertheless when the cell is being tilted or accelerated (in the direction of the axis of the coils), there is a different amount of ferrofluid in the three sections. The voltage induced in the secondary coils strongly depends on the amount of ferrofluid found in the core surrounded by them, so the tilt or the acceleration of the cell becomes measurable. We constructed the sensor in several layouts. The linearly coiled sensor had an excellent resolution. Another version with a toroidal cell had almost perfect linearity and a virtually infinite measuring range. - Highlights: • A ferrofluid core differential transformer can be used to measure tilt. • The theoretical description of two different type of the sensor is introduced. • The measuring range, and the sensitivity depends on the dimensions of the sensor.

Tilted Bianchi type I dust fluid cosmological model in general relativity

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 58; Issue 3. Tilted Bianchi type I dust fluid cosmological model in general ... In this paper, we have investigated a tilted Bianchi type I cosmological model filled with dust of perfect fluid in general relativity. To get a determinate solution, we have assumed a condition  ...

A tilted transversely isotropic slowness surface approximation

KAUST Repository

Stovas, A.

2012-05-09

The relation between vertical and horizontal slownesses, better known as the dispersion relation, for transversely isotropic media with a tilted symmetry axis (TTI) requires solving a quartic polynomial equation, which does not admit a practical explicit solution to be used, for example, in downward continuation. Using a combination of the perturbation theory with respect to the anelliptic parameter and Shanks transform to improve the accuracy of the expansion, we develop an explicit formula for the vertical slowness that is highly accurate for all practical purposes. It also reveals some insights into the anisotropy parameter dependency of the dispersion relation including the low impact that the anelliptic parameter has on the vertical placement of reflectors for a small tilt in the symmetry angle. © 2012 European Association of Geoscientists & Engineers.

Documentation of programs that compute 1) static tilts for a spatially variable slip distribution, and 2) quasi-static tilts produced by an expanding dislocation loop with a spatially variable slip distribution

Science.gov (United States)

McHugh, Stuart

1976-01-01

The material in this report is concerned with the effects of a vertically oriented rectangular dislocation loop on the tilts observed at the free surface of an elastic half-space. Part I examines the effect of a spatially variable static strike-slip distribution across the slip surface. The tilt components as a function of distance parallel, or perpendicular, to the strike of the slip surface are displayed for different slip-versus-distance profiles. Part II examines the effect of spatially and temporally variable slip distributions across the dislocation loop on the quasi-static tilts at the free surface of an elastic half space. The model discussed in part II may be used to generate theoretical tilt versus time curves produced by creep events.

Motion Perception and Manual Control Performance During Passive Tilt and Translation Following Space Flight

Science.gov (United States)

Clement, Gilles; Wood, Scott J.

2010-01-01

This joint ESA-NASA study is examining changes in motion perception following Space Shuttle flights and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data has been collected on 5 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s) combined with body translation (12-22 cm, peak-to-peak) is utilized to elicit roll-tilt perception (equivalent to 20 deg, peak-to-peak). A forward-backward moving sled (24-390 cm, peak-to-peak) with or without chair tilting in pitch is utilized to elicit pitch tilt perception (equivalent to 20 deg, peak-to-peak). These combinations are elicited at 0.15, 0.3, and 0.6 Hz for evaluating the effect of motion frequency on tilt-translation ambiguity. In both devices, a closed-loop nulling task is also performed during pseudorandom motion with and without vibrotactile feedback of tilt. All tests are performed in complete darkness. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for translation motion perception to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. The results of this study indicate that post-flight recovery of motion perception and manual control performance is complete within 8 days following short-duration space missions. Vibrotactile feedback of tilt improves manual control performance both before and after flight.

Effect of manual tilt adjustments on incident irradiance on fixed and tracking solar panels

International Nuclear Information System (INIS)

Lubitz, William David

2011-01-01

Hourly typical meteorological year (TMY3) data was utilized with the Perez radiation model to simulate solar radiation on fixed, azimuth tracking and two axis tracking surfaces at 217 geographically diverse temperate latitude sites across the contiguous United States of America. The optimum tilt angle for maximizing annual irradiation on a fixed south-facing panel varied from being equal to the latitude at low-latitude, high clearness sites, to up to 14 o less than the latitude at a north-western coastal site with very low clearness index. Across the United States, the optimum tilt angle for an azimuth tracking panel was found to be on average 19 o closer to vertical than the optimum tilt angle for a fixed, south-facing panel at the same site. Azimuth tracking increased annual solar irradiation incident on a surface by an average of 29% relative to a fixed south-facing surface at optimum tilt angle. Two axis tracking resulted in an average irradiation increase of 34% relative to the fixed surface. Introduction of manual surface tilt changes during the year produced a greater impact for non-tracking surfaces than it did for azimuth tracking surfaces. Even monthly tilt changes only resulted in an average annual irradiation increase of 5% for fixed panels and 1% for azimuth tracked surfaces, relative to using a single optimized tilt angle in each case. In practice, the decision whether to manually tilt panels requires balancing the added cost in labor and the panel support versus the extra energy generation and the cost value of that energy. A spreadsheet file is available that gives individual results for each of the 217 simulated sites.

Tilt shift determinations with spatial-carrier phase-shift method in temporal phase-shift interferometry

International Nuclear Information System (INIS)

Liu, Qian; Wang, Yang; He, Jianguo; Ji, Fang; Wang, Baorui

2014-01-01

An algorithm is proposed to deal with tilt-shift errors in temporal phase-shift interferometry (PSI). In the algorithm, the tilt shifts are detected with the spatial-carrier phase-shift (SCPS) method and then the tilt shifts are applied as priori information to the least-squares fittings of phase retrieval. The algorithm combines the best features of the SCPS and the temporal PSI. The algorithm could be applied to interferograms of arbitrary aperture without data extrapolation for the Fourier transform is not involved. Simulations and experiments demonstrate the effectiveness of the algorithm. The statistics of simulation results show a satisfied accuracy in detecting tilt-shift errors. Comparisons of the measurements with and without environmental vibration show that the proposed algorithm could compensate tilt-shift errors and retrieve wavefront phase accurately. The algorithm provides an approach to retrieve wavefront phase for the temporal PSI in vibrating environment. (paper)

Tilt rotor tricopter : control system for the holonomic multirotor platform

OpenAIRE

Gjertsen, Sindre; Salem, Daniel

2013-01-01

Masteroppgave i mekatronikk MAS500 2013 – Universitetet i Agder, Grimstad Development of a new approach to the multicopter segment of the Unmanned Areal Vehicle (UAV) family is presented. The system is designed on a T-shaped tricopter platform with ability to tilt all three motors, hereby defined as Tilt Rotor Tricopter (TRT). The highly coupled nonlinear system is investigated through the mathematical model, and verified by simulations. Linearization of the system has been ach...

Influence of tilt training on activation of the autonomic nervous system in patients with vasovagal syncope.

Science.gov (United States)

Gajek, Jacek; Zyśko, Dorota; Halawa, Bogumił; Mazurek, Walentyna

2006-04-01

Tilt training is a new treatment for vasovagal syncope. Its therapeutic efficacy is thought to be the result of the desensitization of cardiopulmonary receptors, but it could be the influence of the tilt training on the activation of the autonomic nervous system as well. The study group consisted of 24 vasovagal patients (17 women and 7 men) aged 32.5 +/- 11.8 years. The diagnostic head-up tilt test was performed according to the Italian protocol with nitroglycerin if necessary. The monitoring head-up tilt test was performed according to the Westminster protocol without provocation, after 1 to 3 months of tilt training. Holter ECG recordings for HRV parameters (time and frequency domain) were obtained from selected 2-min intervals before, during and after the diagnostic and monitoring tilt test. The diagnostic test was positive in the passive phase in 6 and after provocation in 18 patients. During the training period no syncope occurred. Analysing the HRV parameters we demonstrated the following findings: I. mRR decreases immediately after assumption of a vertical position in both tests (diagnostic and monitoring) but in the diagnostic test its further decrease occurs earlier than in the monitoring test; 2. the absolute power of the HF component is greater in the early phase of tilt after tilt training than in the corresponding period in the diagnostic test. After a longer period of tilt training the activation of the sympathetic nervous system in response to the erect position is diminished.

Comparative analysis of diffused solar radiation models for optimum tilt angle determination for Indian locations

International Nuclear Information System (INIS)

Yadav, P.; Chandel, S.S.

2014-01-01

Tilt angle and orientation greatly are influenced on the performance of the solar photo voltaic panels. The tilt angle of solar photovoltaic panels is one of the important parameters for the optimum sizing of solar photovoltaic systems. This paper analyses six different isotropic and anisotropic diffused solar radiation models for optimum tilt angle determination. The predicted optimum tilt angles are compared with the experimentally measured values for summer season under outdoor conditions. The Liu and Jordan model is found to exhibit t lowest error as compared to other models for the location. (author)

Tilting Uranus without a Collision

Science.gov (United States)

Rogoszinski, Zeeve; Hamilton, Douglas P.

2016-10-01

The most accepted hypothesis for the origin of Uranus' 98° obliquity is a giant collision during the late stages of planetary accretion. This model requires a single Earth mass object striking Uranus at high latitudes; such events occur with a probability of about 10%. Alternatively, Uranus' obliquity may have arisen from a sequence of smaller impactors which lead to a uniform distribution of obliquities. Here we explore a third model for tilting Uranus using secular spin-orbit resonance theory. We investigate early Solar System configurations in which a secular resonance between Uranus' axial precession frequency and another planet's orbital node precession frequency might occur.Thommes et al. (1999) hypothesized that Uranus and Neptune initially formed between Jupiter and Saturn, and were then kicked outward. In our scenario, Neptune leaves first while Uranus remains behind. As an exterior Neptune slowly migrates outward, it picks up both Uranus and Saturn in spin-orbit resonances (Ward and Hamilton 2004; Hamilton and Ward 2004). Only a distant Neptune has a nodal frequency slow enough to resonate with Uranus' axial precession.This scenario, with diverging orbits, results in resonance capture. As Neptune migrates outward its nodal precession slows. While in resonance, Uranus and Saturn each tilt a bit further, slowing their axial precession rates to continually match Neptune's nodal precession rate. Tilting Uranus to high obliquities takes a few 100 Myrs. This timescale may be too long to hold Uranus captive between Jupiter and Saturn, and we are investigating how to reduce it. We also find that resonance capture is rare if Uranus' initial obliquity is greater than about 10°, as the probability of capture decreases as the planet's initial obliquity increases. We will refine this estimate by quantifying capture statistics, and running accretion simulations to test the likelihood of a low early obliquity. Our preliminary findings show that most assumptions about

Efficient three-dimensional resist profile-driven source mask optimization optical proximity correction based on Abbe-principal component analysis and Sylvester equation

Science.gov (United States)

Lin, Pei-Chun; Yu, Chun-Chang; Chen, Charlie Chung-Ping

2015-01-01

As one of the critical stages of a very large scale integration fabrication process, postexposure bake (PEB) plays a crucial role in determining the final three-dimensional (3-D) profiles and lessening the standing wave effects. However, the full 3-D chemically amplified resist simulation is not widely adopted during the postlayout optimization due to the long run-time and huge memory usage. An efficient simulation method is proposed to simulate the PEB while considering standing wave effects and resolution enhancement techniques, such as source mask optimization and subresolution assist features based on the Sylvester equation and Abbe-principal component analysis method. Simulation results show that our algorithm is 20× faster than the conventional Gaussian convolution method.

Analysis and Optimization of Wireless Power Transfer Efficiency Considering the Tilt Angle of a Coil

Directory of Open Access Journals (Sweden)

Wei Huang

2018-01-01

Full Text Available Wireless power transfer (WPT based on magnetic resonant coupling is a promising technology in many industrial applications. Efficiency of the WPT system usually depends on the tilt angle of the transmitter or the receiver coil. This work analyzes the effect of the tilt angle on the efficiency of the WPT system with horizontal misalignment. The mutual inductance between two coils located at arbitrary positions with tilt angles is calculated using a numerical analysis based on the Neumann formula. The efficiency of the WPT system with a tilted coil is extracted using an equivalent circuit model with extracted mutual inductance. By analyzing the results, we propose an optimal tilt angle to maximize the efficiency of the WPT system. The best angle to maximize the efficiency depends on the radii of the two coils and their relative position. The calculated efficiencies versus the tilt angle for various WPT cases, which change the radius of RX (r2 = 0.075 m, 0.1 m, 0.15 m and the horizontal distance (y = 0 m, 0.05 m, 0.1 m, are compared with the experimental results. The analytically extracted efficiencies and the extracted optimal tilt angles agree well with those of the experimental results.

An electronic pan/tilt/magnify and rotate camera system

International Nuclear Information System (INIS)

Zimmermann, S.; Martin, H.L.

1992-01-01

A new camera system has been developed for omnidirectional image-viewing applications that provides pan, tilt, magnify, and rotational orientation within a hemispherical field of view (FOV) without any moving parts. The imaging device is based on the fact that the image from a fish-eye lens, which produces a circular image of an entire hemispherical FOV, can be mathematically corrected using high-speed electronic circuitry. More specifically, an incoming fish-eye image from any image acquisition source is captured in the memory of the device, a transformation is performed for the viewing region of interest and viewing direction, and a corrected image is output as a video image signal for viewing, recording, or analysis. The image transformation device can provide corrected images at frame rates compatible with RS-170 standard video equipment. As a result, this device can accomplish the functions of pan, tilt, rotation, and magnification throughout a hemispherical FOV without the need for any mechanical devices. Multiple images, each with different image magnifications and pan-tilt-rotate parameters, can be obtained from a single camera

Tilt Table Therapies for Patients with Severe Disorders of Consciousness: A Randomized, Controlled Trial.

Science.gov (United States)

Krewer, Carmen; Luther, Marianne; Koenig, Eberhard; Müller, Friedemann

2015-01-01

One major aim of the neurological rehabilitation of patients with severe disorders of consciousness (DOC) is to enhance patients' arousal and ability to communicate. Mobilization into a standing position by means of a tilt table has been shown to improve their arousal and awareness. However, due to the frequent occurrence of syncopes on a tilt table, it is easier to accomplish verticalization using a tilt table with an integrated stepping device. The objective of this randomized controlled clinical trial was to evaluate the effectiveness of a tilt table therapy with or without an integrated stepping device on the level of consciousness. A total of 50 participants in vegetative or minimally conscious states 4 weeks to 6 month after injury were treated with verticalization during this randomized controlled trial. Interventions involved ten 1-hour sessions of the specific treatment over a 3-week period. Blinded assessors made measurements before and after the intervention period, as well as after a 3-week follow-up period. The coma recovery scale-revised (CRS-R) showed an improvement by a median of 2 points for the group receiving tilt table with integrated stepping (Erigo). The rate of recovery of the group receiving the conventional tilt table therapy significantly increased by 5 points during treatment and by an additional 2 points during the 3-week follow-up period. Changes in spasticity did not significantly differ between the two intervention groups. Compared to the conventional tilt table, the tilt table with integrated stepping device failed to have any additional benefit for DOC patients. Verticalization itself seems to be beneficial though and should be administered to patients in DOC in early rehabilitation. Trial Registration: Current Controlled Trials Ltd (www.controlled-trials.com), identifier number ISRCTN72853718.

Tilt Table Therapies for Patients with Severe Disorders of Consciousness: A Randomized, Controlled Trial.

Directory of Open Access Journals (Sweden)

Carmen Krewer

Full Text Available One major aim of the neurological rehabilitation of patients with severe disorders of consciousness (DOC is to enhance patients' arousal and ability to communicate. Mobilization into a standing position by means of a tilt table has been shown to improve their arousal and awareness. However, due to the frequent occurrence of syncopes on a tilt table, it is easier to accomplish verticalization using a tilt table with an integrated stepping device. The objective of this randomized controlled clinical trial was to evaluate the effectiveness of a tilt table therapy with or without an integrated stepping device on the level of consciousness. A total of 50 participants in vegetative or minimally conscious states 4 weeks to 6 month after injury were treated with verticalization during this randomized controlled trial. Interventions involved ten 1-hour sessions of the specific treatment over a 3-week period. Blinded assessors made measurements before and after the intervention period, as well as after a 3-week follow-up period. The coma recovery scale-revised (CRS-R showed an improvement by a median of 2 points for the group receiving tilt table with integrated stepping (Erigo. The rate of recovery of the group receiving the conventional tilt table therapy significantly increased by 5 points during treatment and by an additional 2 points during the 3-week follow-up period. Changes in spasticity did not significantly differ between the two intervention groups. Compared to the conventional tilt table, the tilt table with integrated stepping device failed to have any additional benefit for DOC patients. Verticalization itself seems to be beneficial though and should be administered to patients in DOC in early rehabilitation. Trial Registration: Current Controlled Trials Ltd (www.controlled-trials.com, identifier number ISRCTN72853718.

An iterative fast sweeping based eikonal solver for tilted orthorhombic media

KAUST Repository

Waheed, Umair bin

2014-08-01

Computing first-arrival traveltimes of quasi-P waves in the presence of anisotropy is important for high-end near-surface modeling, microseismic-source localization, and fractured-reservoir characterization, and requires solving an anisotropic eikonal equation. Anisotropy deviating from elliptical anisotropy introduces higher-order nonlinearity into the eikonal equation, which makes solving the eikonal equation a challenge. We address this challenge by iteratively solving a sequence of simpler tilted elliptically anisotropic eikonal equations. At each iteration, the source function is updated to capture the effects of the higher order nonlinear terms. We use Aitken extrapolation to speed up the convergence rate of the iterative algorithm. The result is an algorithm for first-arrival traveltime computations in tilted anisotropic media. We demonstrate our method on tilted transversely isotropic media and tilted orthorhombic media. Our numerical tests demonstrate that the proposed method can match the first arrivals obtained by wavefield extrapolation, even for strong anisotropy and complex structures. Therefore, for the cases where oneor two-point ray tracing fails, our method may be a potential substitute for computing traveltimes. Our approach can be extended to anisotropic media with lower symmetries, such as monoclinic or even triclinic media.

An iterative fast sweeping based eikonal solver for tilted orthorhombic media

KAUST Repository

Waheed, Umair bin; Yarman, Can Evren; Flagg, Garret

2014-01-01

Computing first-arrival traveltimes of quasi-P waves in the presence of anisotropy is important for high-end near-surface modeling, microseismic-source localization, and fractured-reservoir characterization, and requires solving an anisotropic eikonal equation. Anisotropy deviating from elliptical anisotropy introduces higher-order nonlinearity into the eikonal equation, which makes solving the eikonal equation a challenge. We address this challenge by iteratively solving a sequence of simpler tilted elliptically anisotropic eikonal equations. At each iteration, the source function is updated to capture the effects of the higher order nonlinear terms. We use Aitken extrapolation to speed up the convergence rate of the iterative algorithm. The result is an algorithm for first-arrival traveltime computations in tilted anisotropic media. We demonstrate our method on tilted transversely isotropic media and tilted orthorhombic media. Our numerical tests demonstrate that the proposed method can match the first arrivals obtained by wavefield extrapolation, even for strong anisotropy and complex structures. Therefore, for the cases where oneor two-point ray tracing fails, our method may be a potential substitute for computing traveltimes. Our approach can be extended to anisotropic media with lower symmetries, such as monoclinic or even triclinic media.

Hyperbolic umbilic caustics from oblate water drops with tilted illumination: Observations

Science.gov (United States)

Jobe, Oli; Thiessen, David B.; Marston, Philip L.

2017-11-01

Various groups have reported observations of hyperbolic umbilic diffraction catastrophe patterns in the far-field scattering by oblate acoustically levitated drops with symmetric illumination. In observations of that type the drop's symmetry axis is vertical and the illuminating light beam (typically an expanded laser beam) travels horizontally. In the research summarized here, scattering patterns in the primary rainbow region and drop measurements were recorded with vertically tilted laser beam illumination having a grazing angle as large as 4 degrees. The findings from these observations may be summarized as follows: (a) It remains possible to adjust the drop aspect ratio (diameter/height) = D/H so as to produce a V-shaped hyperbolic umbilic focal section (HUFS) in the far-field scattering. (b) The shift in the required D/H was typically an increase of less than 1% and was quadratic in the tilt. (c) The apex of the V-shaped HUFS was shifted vertically by an amount proportional to the tilt with a coefficient close to unity. The levitated drops had negligible up-down asymmetry. Our method of investigation should be useful for other generalized rainbows with tilted illumination.

Cellular structures using U_q-tilting modules

DEFF Research Database (Denmark)

Andersen, Henning Haahr; Stroppel, Catharina; Tubbenhauer, Daniel

We use the theory of Uq-tilting modules to construct cellular bases for centralizer algebras. Our methods are quite general and work for any quantum group Uq attached to a Cartan matrix and include the non semi-simple cases for q being a root of unity and ground fields of positive characteristic........ Our approach also generalize to certain categories containing infinite dimensional modules. As an application, we recover several known cellular structures (which can all be fit into our general set-up) as we illustrate in a list of examples.......We use the theory of Uq-tilting modules to construct cellular bases for centralizer algebras. Our methods are quite general and work for any quantum group Uq attached to a Cartan matrix and include the non semi-simple cases for q being a root of unity and ground fields of positive characteristic...

Single particle and molecular assembly analysis of polyribosomes by single- and double-tilt cryo electron tomography

Energy Technology Data Exchange (ETDEWEB)

Myasnikov, Alexander G. [IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Department of Integrative Structural Biology, Centre National de la Recherche Scientifique (CNRS) UMR 7104/ Institut National de la Santé de la Recherche Médicale INSERM U964/ Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch (France); Afonina, Zhanna A. [Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region (Russian Federation); Klaholz, Bruno P., E-mail: klaholz@igbmc.fr [IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Department of Integrative Structural Biology, Centre National de la Recherche Scientifique (CNRS) UMR 7104/ Institut National de la Santé de la Recherche Médicale INSERM U964/ Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch (France)

2013-03-15

Cryo electron tomography (cryo-ET) can provide cellular and molecular structural information on various biological samples. However, the detailed interpretation of tomograms reconstructed from single-tilt data tends to suffer from low signal-to-noise ratio and artefacts caused by some systematically missing angular views. While these can be overcome by sub-tomogram averaging, they remain limiting for the analysis of unique structures. Double-tilt ET can improve the tomogram quality by acquiring a second tilt series after an in-plane rotation, but its usage is not widespread yet because it is considered technically demanding and it is rarely used under cryo conditions. Here we show that double-tilt cryo-ET improves the quality of 3D reconstructions so significantly that even single particle analysis can be envisaged despite of the intrinsically low image contrast obtained from frozen-hydrated specimens. This is illustrated by the analysis of eukaryotic polyribosomes in which individual ribosomes were reconstructed using single-tilt, partial and full double-tilt geometries. The improved tomograms favour the faster convergence of iterative sub-tomogram averaging and allow a better 3D classification using multivariate statistical analysis. Our study of single particles and molecular assemblies within polysomes illustrates that the dual-axis approach is particularly useful for cryo applications of ET, both for unique objects and for structures that can be classified and averaged. - Highlights: ► Double-tilt cryo-ET improves 3D reconstructions thus making single particle analysis possible. ► Dual-axis cryo-ET data favour a faster convergence of iterative sub-tomogram averaging. ► Individual ribosomes were reconstructed from single-tilt, partial/ full double-tilt geometries. ► Double-tilt cryo-ET facilitates analysis of larger molecular assemblies such as in cell sections. ► Dual-axis cryo-ET is applicable to unique objects and to structures that can be

Acute effects of head-down tilt and hypoxia on modulators of fluid homeostasis

Science.gov (United States)

Whitson, P. A.; Cintron, N. M.; Pietrzyk, R. A.; Scotto, P.; Loeppky, J. A.

1994-01-01

In an effort to understand the interaction between acute postural fluid shifts and hypoxia on hormonal regulation of fluid homeostasis, the authors measured the responses to head-down tilt with and without acute exposure to normobaric hypoxia. Plasma atrial natriuretic peptide (ANP), cyclic guanosine monophosphate (cGMP), cyclic adenosine monophosphate (cAMP), plasma aldosterone (ALD), and plasma renin activity (PRA) were measured in six healthy male volunteers who were exposed to a head-down tilt protocol during normoxia and hypoxia. The tilt protocol consisted of a 17 degrees head-up phase (30 minutes), a 28 degrees head-down phase (1 hour), and a 17 degrees head-up recovery period (2 hours, with the last hour normoxic in both experiments). Altitude equivalent to 14,828 ft was simulated by having the subjects breathe an inspired gas mixture with 13.9% oxygen. The results indicate that the postural fluid redistribution associated with a 60-minute head-down tilt induces the release of ANP and cGMP during both hypoxia and normoxia. Hypoxia increased cGMP, cAMP, ALD, and PRA throughout the protocol and significantly potentiated the increase in cGMP during head-down tilt. Hypoxia had no overall effect on the release of ANP, but appeared to attenuate the increase with head-down tilt. This study describes the acute effects of hypoxia on the endocrine response during fluid redistribution and suggests that the magnitude, but not the direction, of these changes with posture is affected by hypoxia.

Use of an Android application “clinometer” for measurement of head down tilt given during subarachnoid block

Science.gov (United States)

Dixit, RB; Neema, MM

2016-01-01

Context: Head down tilt is given to patients after sub arachnoid block for adjustment of height of block. However, the amount of tilt given is subjective and cannot be documented. Aims: We used an android application named “clinometer” to measure exact degree of tilt given by anesthesiologists as their routine practice. Settings and Design: This observational study, at a medical college hospital, was done in 130 patients given sub arachnoid block for lower abdominal surgeries. Materials and Methods: We observed and documented vital data of patients and measured tilt given by application “clinometer.” Results: We observed that the application was easy to use and measured tilt each time. The result obtained can be documented, digitally saved and transferred. In 130 patients studied, we observed incidence of degree of tilt as follows: 6-8° tilt in 38 patients (29.23%), 8-10 in 36 patients (27.69%), 10-12 in 30 patients (23.08%), 12-14 in 12 patients (9.23%) and 14-16° tilt in 14 patients (10.77%). Use of application was received with enthusiasm by practicing anesthesiologists. Various possible uses of this application are discussed. PMID:26955307

Patient Specific Modeling of Head-Up Tilt

DEFF Research Database (Denmark)

Williams, Nakeya; Wright, Andrew; Mehlsen, Jesper

2014-01-01

Short term cardiovascular responses to head-up tilt (HUT) experiments involve complex cardiovascular regulation in order to maintain blood pressure at homeostatic levels. This manuscript presents a patient specific compartmental model developed to predict dynamic changes in heart rate and arterial...

Exploring integral controllers in actively-lubricated tilting-pad journal bearings

DEFF Research Database (Denmark)

Salazar, Jorge Andrés González; Santos, Ilmar

2015-01-01

investigation of integral controllers for feedback-controlled lubrication with the aim of: a) presetting the static journal center and consequently exploring the changes of bearing dynamic properties; b) obtaining an integral controller capable of re-positioning the static journal eccentricity for matching......Active tilting-pad journal bearings with radial oil injection combine good stability properties of conventional tilting-pad journal bearings with the capability of improving their dynamic properties even more by control techniques. The main contribution of this work is the experimental...

Research on Method of Photoelectric Measurement for Tilt Angle of Scanning Mirror of Infrared Earth Sensor

Energy Technology Data Exchange (ETDEWEB)

Xu, X P; Zhang, G Y; Zhang, N; Wang, L Y [Changchun University of Science and Technology, 130022, Changchun (China)

2006-10-15

Tilt angle of scanning mirror is one of the important qualifications of performance measurement on the earth surface for swing scanning mode infrared the earth sensor. In order to settle the problem of measuring the tilt angle of scanning mirror in dynamic, real-time and non-contact, based on laser inspecting technology and CCD probing technology, a method of laser dynamical measurement for tilt angle of scanning mirror of the infrared earth sensor is presented. The measurement system developed in this paper can accomplish the dynamic and static laser non-contact measurement for the parameters of scanning mirror such as tilt angle, swing frequency, etc. In this paper the composition and overall structure of system are introduced. Emphasis on analyzing and discussing the theory of dynamically measuring tilt angle of scanning mirror, the problems of data processing and error correction are settled by established mathematic model of system. The accuracy of measurement system is verified by experiment, the results indicated that measurement range of system for tilt angle is 0{approx}{+-}12{sup 0}, accuracy of dynamic and static measurement is less than {+-}0.05{sup 0}, this method of dynamically measuring tilt angle is suitable.

Evaluation of tilted cone-beam CT orbits in the development of a dedicated hybrid mammotomograph

International Nuclear Information System (INIS)

Madhav, P; Crotty, D J; Tornai, M P; McKinley, R L

2009-01-01

A compact dedicated 3D breast SPECT-CT (mammotomography) system is currently under development. In its initial prototype, the cone-beam CT sub-system is restricted to a fixed-tilt circular rotation around the patient's pendant breast. This study evaluated stationary-tilt angles for the CT sub-system that will enable maximal volumetric sampling and viewing of the breast and chest wall. Images of geometric/anthropomorphic phantoms were acquired using various fixed-tilt circular and 3D sinusoidal trajectories. The iteratively reconstructed images showed more distortion and attenuation coefficient inaccuracy from tilted cone-beam orbits than from the complex trajectory. Additionally, line profiles illustrated cupping artifacts in planes distal to the central plane of the tilted cone-beam, otherwise not apparent for images acquired with complex trajectories. This indicates that undersampled cone-beam data may be an additional cause of cupping artifacts. High-frequency objects could be distinguished for all trajectories, but their shapes and locations were corrupted by out-of-plane frequency information. Although more acrylic balls were visualized with a fixed-tilt and nearly flat cone-beam at the posterior of the breast, 3D complex trajectories have less distortion and more complete sampling throughout the reconstruction volume. While complex trajectories would ideally be preferred, negatively fixed-tilt source-detector configuration demonstrates minimally distorted patient images.

Doses to patients from medical X-ray examinations in the UK. 2000 review

CERN Document Server

Hart, D; Wall, B F

2002-01-01

In 1992 NRPB established a National Collation Centre for measurements of doses to patients made by x-ray departments throughout the UK. This report is the second in a series of five-yearly reviews of the national patient dose database and analyses the information collected during the period January 1996 to December 2000. It includes the results of 28,000 entrance surface dose (ESD) measurements and 13,000 dose-area product (DAP) measurements for single radiographs, and 140,000 DAP measurements and 128,000 records of the fluoroscopy time for complete examinations, collected from 371 hospitals throughout the UK. Information on the patient dose distributions and exposure conditions for over 30 types of examination and radiograph is presented. National reference doses based on the rounded third quartile values of these dose distributions are recommended and are seen to be about 20% lower than corresponding values in the previous (1995) review. They have approximately halved since the original UK national referenc...

"Happiness and Education": Tilting at Windmills?

Science.gov (United States)

Verducci, Susan

2013-01-01

This essay explores the question: Is Nel Noddings a visionary who sees past the constraints of contemporary education or is she, like Don Quixote, madly tilting at windmills in her description and defense of happiness as an educational aim? Viewing the educational aim of happiness as an ideal raises substantial challenges for the practicality of…

Profile relaxation and tilt instability in a field-reversed configuration

International Nuclear Information System (INIS)

Ohtani, H.; Horiuchi, R.; Sato, T.

2003-01-01

The profile relaxation from a magnetic hydrodynamic (MHD) profile to a kinetic equilibrium in field-reversed configurations (FRCs) is investigated by two-dimensional electromagnetic particle simulation. The radial oscillation takes place in order to relax an excess energy in the MHD profile, and the system spontaneously relaxes toward a kinetic equilibrium. In this kinetic equilibrium, the hollow electron current profile is realized as a result of the combined effects of the single particle orbits and the ion finite Larmor radius, and the ion current profile becomes peaked due to the effect of the ion meandering motion. Three-dimensional full electromagnetic particle simulation is also performed to study the stability of these kinetic equilibrium against the tilt mode. The growth rate of the tilt instability is reduced by the kinetic effects. It is found that the stabilization effect of tilt mode becomes much distinct when the current density changes from the peaked profile to the hollow one. (author)

Profile relaxation and tilt instability in a field-reversed configuration

International Nuclear Information System (INIS)

Ohtani, H.; Horiuchi, R.; Sato, T.

2002-10-01

The profile relaxation from a magnetohydrodynamic (MHD) profile to a kinetic equilibrium in field-reversed configurations (FRCs) is investigated by two-dimensional electromagnetic particle simulation. The radial oscillation takes place in order to relax an excess energy in the MHD profile, and the system spontaneously relaxes toward a kinetic equilibrium. In this kinetic equilibrium, the hollow electron current profile is realized as a result of the combined effects of the single particle orbits and the ion finite Larmor radius, and the ion current profile becomes peaked due to the effect of the ion meandering motion. Three-dimensional full electromagnetic particle simulation is also performed to study the stability of these kinetic equilibrium against the tilt mode. The growth rate of the tilt instability is reduced by the kinetic effects. It is found that the stabilization effect of tilt mode becomes much distinct when the current density changes from the peaked profile to the hollow one. (author)

Profile relaxation and tilt instability in a field-reversed configuration

International Nuclear Information System (INIS)

Ohtani, H.; Horiuchi, R.; Sato, T.

2002-01-01

The profile relaxation from a magnetichydrodynamic (MHD) profile to a kinetic equilibrium in field-reversed configurations (FRCs) in investigated by two-dimensional electromagnetic particle simulation. The radial oscillation takes place in order to relax an excess energy in the MHD profile, and the system spontaneously relaxes toward a kinetic equilibrium. In this kinetic equilibrium, the hollow electron current profile is realized as a result of the combined effects of the single particle orbits and the ion finite Larmor radius, and the ion current profile becomes peaked due to the effect of the ion meandering motion. Three-dimensional full electromagnetic particle simulations is also performed to study the stability of these kinetic equilibrium against the tilt mode. The growth rate of the tilt instability is reduced by the kinetic is effects. It is found that the stabilization effect of tilt mode becomes much distinct when the current density changes from the peaked profile to the hollow one. (author)

High-gain thompson-scattering X-ray free-electron laser by time-synchronic laterally tilted optical wave

Science.gov (United States)

Chang, Chao; Tang, Chuanxiang; Wu, Juhao

2017-05-09

An improved optical undulator for use in connection with free electron radiation sources is provided. A tilt is introduced between phase fronts of an optical pulse and the pulse front. Two such pulses in a counter-propagating geometry overlap to create a standing wave pattern. A line focus is used to increase the intensity of this standing wave pattern. An electron beam is aligned with the line focus. The relative angle between pulse front and phase fronts is adjusted such that there is a velocity match between the electron beam and the overlapping optical pulses along the line focus. This allows one to provide a long interaction length using short and intense optical pulses, thereby greatly increasing the radiation output from the electron beam as it passes through this optical undulator.

The aurora at quite magnetospheric conditions: Repeatability and dipole tilt angle dependence

International Nuclear Information System (INIS)

Oznovich, I.; Eastes, R.W.; Huffman, R.E.; Tur, M.; Glaser, I.

1993-01-01

Is there a magnetospheric ground state? Do the position and size of the auroral oval depend on the magnetic dipole tilt angle at quiet magnetospheric conditions? In order to address these questions, northern hemisphere images of the aurora at 1356 Angstrom, obtained by Polar BEAR at solar minimum (beginning of 1987), were related to high temporal resolution IPM 8 measurements of the interplanetary magnetic field, to solar wind velocity, and to the ground-based activity index Kp. The first problem was addressed by a two-dimensional correlation study of the repeatability of auroral emissions in corrected geomagnetic space at conditions of minimum energy transfer from the magnetosphere. The correlation measure of auroral images was 0.6-0.85. Error simulations indicate that given the uncertainties in pixel position and intensity, the maximum expected value of the correlation measure is 0.65-0.9. The notion of a ground state magnetosphere is therefore supported by this data. Repeatability was found at the same level regardless of time or reconfigurations of the magnetosphere between images and independent of magnetic time sector. The second problem was addressed by relating latitudinal shifts of the aurora with dipole tilt angle without resorting to auroral boundary specification. This data indicate that the latitude of the continuous aurora is related to the dipole tilt angle at quiet magnetospheric conditions. In the winter hemisphere a 10 degrees increase in the dipole tilt angle causes a 1 degree decrease (increase) in the latitude of auroral emissions at noon (midnight). The magnetic local time distribution of the latitudinal shifts with dipole tilt angle support a simple model in which the dipole tilt angle determines the position of the center of the auroral circle along the magnetic meridian 1320-0120 MLT (for IMF B y positive) and does not affect its radius. 22 refs., 8 figs

Regional energy and environment exploration in Belgium 2000

International Nuclear Information System (INIS)

Ciujpers, C.

1994-01-01

The prospects for energy consumption and related emission of NO x , SO 2 , and CO 2 gases for the year 2000 are reported for three regions (the Flanders, Brussels Metropolitan, and Wallonie region) in Belgium. Two scenarios were developed: a reference scenario in which the policy of 1990 is continued on the one hand and a policy making scenario in which the energy and carbon taxes, proposed by the European Commission are introduced on the other hand. This methodology allows to estimate the impact of the energy and carbon taxes on energy consumption and the emission of greenhouse gases. In conclusion is stated that at continued policy, primary energy consumption in Belgium will rise 22.4 percent from 1990 to 2000. The introduction of energy and carbon taxes will result in a reduction of the primary energy consumption with 5.9 percent. At a continued policy NO X , SO 2 emissions will reduce respectively 27.2 percent, 18.8 percent while CO 2 emissions will increase 21.4 percent from 1990 till 2000. Compared to the continued scenario, the introduction of energy and carbon taxes in Belgium will lead to additional NO X and CO 2 emissions of respectively 6.5 and 13.6 percent, while the CO 2 emission will be reduced by 9.5 percent in 2000. It is concluded that the proposed energy and carbon taxes are important impulses for the realization of the Belgian objective to reduce the CO 2 -emission from 1990 to 2000 by five percent. (A.S.) 5 Figs. 9 Tabs

Características del análisis proximal de harinas obtenidas de frutos de plátanos variedades Papocho y Pelipita (Musa ABB Simmonds)

OpenAIRE

Pedro Juan Espitia-Pérez; Yuri Janio Pardo-Plaza; Alba Patricia Montalvo-Puente

2013-01-01

En el estudio se hizo un análisis proximal de las harinas crudas sin tratar obtenidas de frutos de las variedades de plátano Papocho y Pelipita (Musa ABB Simmonds) no comerciales en diferentes etapas de desarrollo y se analizó su posible uso como materia prima alimenticia. Los resultados comparativos mostraron que los contenidos y porcentajes de fibra cruda en Papocho variaron entre 2.54 y 1.37% y en Pelipita entre 6.45 y 0.88%, la proteína cruda en Papocho entre 6.70 y 3.81% y en Pelipita en...

Human cutaneous vascular responses to whole-body tilting, Gz centrifugation, and LBNP

Science.gov (United States)

Watenpaugh, Donald E.; Breit, Gregory A.; Buckley, Theresa M.; Ballard, Richard E.; Murthy, Gita; Hargens, Alan R.

2004-01-01

We hypothesized that gravitational stimuli elicit cardiovascular responses in the following order with gravitational stress equalized at the level of the feet, from lowest to highest response: short-(SAC) and long-arm centrifugation (LAC), tilt, and lower body negative pressure (LBNP). Up to 15 healthy subjects underwent graded application of the four stimuli. Laser-Doppler flowmetry measured regional skin blood flow. At 0.6 G(z) (60 mmHg LBNP), tilt and LBNP similarly reduced leg skin blood flow to approximately 36% of supine baseline levels. Flow increased back toward baseline levels at 80-100 mmHg LBNP yet remained stable during 0.8-1.0 G(z) tilt. Centrifugation usually produced less leg vasoconstriction than tilt or LBNP. Surprisingly, SAC and LAC did not differ significantly. Thigh responses were less definitive than leg responses. No gravitational vasoconstriction occurred in the neck. All conditions except SAC increased heart rate, according to our hypothesized order. LBNP may be a more effective and practical means of simulating cardiovascular effects of gravity than centrifugation.

Tilting-Twisting-Rolling: a pen-based technique for compass geometric construction

Institute of Scientific and Technical Information of China (English)

Fei LYU; Feng TIAN; Guozhong DAI; Hongan WANG

2017-01-01

This paper presents a new pen-based technique,Tilting-Twisting-Rolling,to support compass geometric construction.By leveraging the 3D orientation information and 3D rotation information of a pen,this technique allows smooth pen action to complete multi-step geometric construction without switching task states.Results from a user study show this Tilting-Twisting-Rolling technique can improve user performance and user experience in compass geometric construction.

Solar Cycle Variability Induced by Tilt Angle Scatter in a Babcock-Leighton Solar Dynamo Model

Science.gov (United States)

Karak, Bidya Binay; Miesch, Mark

2017-09-01

We present results from a three-dimensional Babcock-Leighton (BL) dynamo model that is sustained by the emergence and dispersal of bipolar magnetic regions (BMRs). On average, each BMR has a systematic tilt given by Joy’s law. Randomness and nonlinearity in the BMR emergence of our model produce variable magnetic cycles. However, when we allow for a random scatter in the tilt angle to mimic the observed departures from Joy’s law, we find more variability in the magnetic cycles. We find that the observed standard deviation in Joy’s law of {σ }δ =15^\\circ produces a variability comparable to the observed solar cycle variability of ˜32%, as quantified by the sunspot number maxima between 1755 and 2008. We also find that tilt angle scatter can promote grand minima and grand maxima. The time spent in grand minima for {σ }δ =15^\\circ is somewhat less than that inferred for the Sun from cosmogenic isotopes (about 9% compared to 17%). However, when we double the tilt scatter to {σ }δ =30^\\circ , the simulation statistics are comparable to the Sun (˜18% of the time in grand minima and ˜10% in grand maxima). Though the BL mechanism is the only source of poloidal field, we find that our simulations always maintain magnetic cycles even at large fluctuations in the tilt angle. We also demonstrate that tilt quenching is a viable and efficient mechanism for dynamo saturation; a suppression of the tilt by only 1°-2° is sufficient to limit the dynamo growth. Thus, any potential observational signatures of tilt quenching in the Sun may be subtle.

Experimental Results of Network-Assisted Interference Suppression Scheme Using Adaptive Beam-Tilt Switching

Directory of Open Access Journals (Sweden)

Tomoki Murakami

2017-01-01

Full Text Available This paper introduces a network-assisted interference suppression scheme using beam-tilt switching per frame for wireless local area network systems and its effectiveness in an actual indoor environment. In the proposed scheme, two access points simultaneously transmit to their own desired station by adjusting angle of beam-tilt including transmit power assisted from network server for the improvement of system throughput. In the conventional researches, it is widely known that beam-tilt is effective for ICI suppression in the outdoor scenario. However, the indoor effectiveness of beam-tilt for ICI suppression has not yet been indicated from the experimental evaluation. Thus, this paper indicates the effectiveness of the proposed scheme by analyzing multiple-input multiple-output channel matrices from experimental measurements in an office environment. The experimental results clearly show that the proposed scheme offers higher system throughput than the conventional scheme using just transmit power control.

Realization of a tilted reference wave for electron holography by means of a condenser biprism

Energy Technology Data Exchange (ETDEWEB)

Röder, Falk, E-mail: Falk.Roeder@tu-dresden.de [Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse (France); Houdellier, Florent; Denneulin, Thibaud; Snoeck, Etienne; Hÿtch, Martin [CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse (France)

2016-02-15

As proposed recently, a tilted reference wave in off-axis electron holography is expected to be useful for aberration measurement and correction. Furthermore, in dark-field electron holography, it is considered to replace the reference wave, which is conventionally diffracted in an unstrained object area, by a well-defined object-independent reference wave. Here, we first realize a tilted reference wave by employing a biprism placed in the condenser system above three condenser lenses producing a relative tilt magnitude up to 20/nm at the object plane (300 kV). Paraxial ray-tracing predicts condenser settings for a parallel illumination at the object plane, where only one half of the round illumination disc is tilted relative to the optical axis without displacement. Holographic measurements verify the kink-like phase modulation of the incident beam and return the interference fringe contrast as a function of the relative tilt between both parts of the illumination. Contrast transfer theory including condenser aberrations and biprism instabilities was applied to explain the fringe contrast measurement. A first dark-field hologram with a tilted – object-free – reference wave was acquired and reconstructed. A new application for bright/dark-field imaging is presented.

A Fiber Bragg grating based tilt sensor suitable for constant temperature room

International Nuclear Information System (INIS)

Tang, Guoyu; Wei, Jue; Zhou, Wei; Wu, Mingyu; Yang, Meichao; Xie, Ruijun; Xu, Xiaofeng

2015-01-01

Constant-temperature rooms have been widely used in industrial production, quality testing, and research laboratories. This paper proposes a high-precision tilt sensor suitable for a constant- temperature room, which has achieved a wide-range power change while the fiber Bragg grating (FBG) reflection peak wavelength shifted very little, thereby demonstrating a novel method for obtaining a high-precision tilt sensor. This paper also studies the effect of the reflection peak on measurement precision. The proposed sensor can distinguish the direction of tilt with an excellent sensitivity of 403 dBm/° and a highest achievable resolution of 2.481 × 10 −5 ° (that is, 0.08% of the measuring range). (paper)

Tilted seat position for non-ambulant individuals with neurological and neuromuscular impairment: a systematic review.

Science.gov (United States)

Michael, S M; Porter, D; Pountney, T E

2007-12-01

To determine the effects of tilt-in-space seating on outcomes for people with neurological or neuromuscular impairment who cannot walk. Search through electronic databases (MEDLINE, Embase, CINAHL, AMED). Discussions with researchers who are active in field. Selection criteria included interventional studies that investigated the effects of seat tilt on outcome or observational studies that identified outcomes for those who had used tilt-in-space seating in populations with neurological or neuromuscular impairments. Two reviewers independently selected trials for inclusion, assessed quality and extracted data. Nineteen studies were identified which fulfilled the selection criteria. Seventeen of these were essentially before-after studies investigating the immediate effects of tilting the seating. All studies looked at populations with neurological impairment, and most were on children with cerebral palsy (n=8) or adults with spinal cord injury (n=8). REVIEWER'S CONCLUSION: Posterior tilt can reduce pressures at the interface under the pelvis.

High thermoelectric properties of (Sb, Bi)2Te3 nanowire arrays by tilt-structure engineering

Science.gov (United States)

Tan, Ming; Hao, Yanming; Deng, Yuan; Chen, Jingyi

2018-06-01

In this paper, we present an innovative tilt-structure design concept for (Sb, Bi)2Te3 nanowire array assembled by high-quality nanowires with well oriented growth, utilizing a simple vacuum thermal evaporation technique. The unusual tilt-structure (Sb, Bi)2Te3 nanowire array with a tilted angle of 45° exhibits a high thermoelectric dimensionless figure-of-merit ZT = 1.72 at room temperature. The relatively high ZT value in contrast to that of previously reported (Sb, Bi)2Te3 materials and the vertical (Sb, Bi)2Te3 nanowire arrays evidently reveals the crucial role of the unique tilt-structure in favorably influencing carrier and phonon transport properties, resulting in a significantly improved ZT value. The transport mechanism of such tilt-structure is proposed and investigated. This method opens a new approach to optimize nano-structure in thin films for next-generation thermoelectric materials and devices.

A hydrodynamic treatment of the tilted cold dark matter cosmological scenario

Science.gov (United States)

Cen, Renyue; Ostriker, Jeremiah P.

1993-01-01

A standard hydrodynamic code coupled with a particle-mesh code is used to compute the evolution of a tilted cold dark matter (TCDM) model containing both baryonic matter and dark matter. Six baryonic species are followed, with allowance for both collisional and radiative ionization in every cell. The mean final Zel'dovich-Sunyaev y parameter is estimated to be (5.4 +/- 2.7) x 10 exp -7, below currently attainable observations, with an rms fluctuation of about (6.0 +/- 3.0) x 10 exp -7 on arcmin scales. The rate of galaxy formation peaks at a relatively late epoch (z is about 0.5). In the case of mass function, the smallest objects are stabilized against collapse by thermal energy: the mass-weighted mass spectrum peaks in the vicinity of 10 exp 9.1 solar masses, with a reasonable fit to the Schechter luminosity function if the baryon mass to blue light ratio is about 4. It is shown that a bias factor of 2 required for the model to be consistent with COBE DMR signals is probably a natural outcome in the present multiple component simulations.

Tip-tilt compensation: Resolution limits for ground-based telescopes using laser guide star adaptive optics

International Nuclear Information System (INIS)

Olivier, S.S.; Max, C.E.; Gavel, D.T.; Brase, J.M.

1992-01-01

The angular resolution of long-exposure images from ground-based telescopes equipped with laser guide star adaptive optics systems is fundamentally limited by the the accuracy with which the tip-tilt aberrations introduced by the atmosphere can be corrected. Assuming that a natural star is used as the tilt reference, the residual error due to tilt anisoplanatism can significantly degrade the long-exposure resolution even if the tilt reference star is separated from the object being imaged by a small angle. Given the observed distribution of stars in the sky, the need to find a tilt reference star quite close to the object restricts the fraction of the sky over which long-exposure images with diffraction limited resolution can be obtained. In this paper, the authors present a comprehensive performance analysis of tip-tilt compensation systems that use a natural star as a tilt reference, taking into account properties of the atmosphere and of the Galactic stellar populations, and optimizing over the system operating parameters to determine the fundamental limits to the long-exposure resolution. Their results show that for a ten meter telescope on Mauna Kea, if the image of the tilt reference star is uncorrected, about half the sky can be imaged in the V band with long-exposure resolution less than 60 milli-arc-seconds (mas), while if the image of the tilt reference star is fully corrected, about half the sky can be imaged in the V band with long-exposure resolution less than 16 mas. Furthermore, V band images long-exposure resolution of less than 16 mas may be obtained with a ten meter telescope on Mauna Kea for unresolved objects brighter than magnitude 22 that are fully corrected by a laser guide star adaptive optics system. This level of resolution represents about 70% of the diffraction limit of a ten meter telescope in the V band and is more than a factor of 45 better than the median seeing in the V band on Mauna Kea

Gravity influences the visual representation of object tilt in parietal cortex.

Science.gov (United States)

Rosenberg, Ari; Angelaki, Dora E

2014-10-22

Sensory systems encode the environment in egocentric (e.g., eye, head, or body) reference frames, creating inherently unstable representations that shift and rotate as we move. However, it is widely speculated that the brain transforms these signals into an allocentric, gravity-centered representation of the world that is stable and independent of the observer's spatial pose. Where and how this representation may be achieved is currently unknown. Here we demonstrate that a subpopulation of neurons in the macaque caudal intraparietal area (CIP) visually encodes object tilt in nonegocentric coordinates defined relative to the gravitational vector. Neuronal responses to the tilt of a visually presented planar surface were measured with the monkey in different spatial orientations (upright and rolled left/right ear down) and then compared. This revealed a continuum of representations in which planar tilt was encoded in a gravity-centered reference frame in approximately one-tenth of the comparisons, intermediate reference frames ranging between gravity-centered and egocentric in approximately two-tenths of the comparisons, and in an egocentric reference frame in less than half of the comparisons. Altogether, almost half of the comparisons revealed a shift in the preferred tilt and/or a gain change consistent with encoding object orientation in nonegocentric coordinates. Through neural network modeling, we further show that a purely gravity-centered representation of object tilt can be achieved directly from the population activity of CIP-like units. These results suggest that area CIP may play a key role in creating a stable, allocentric representation of the environment defined relative to an "earth-vertical" direction. Copyright © 2014 the authors 0270-6474/14/3414170-11$15.00/0.

Capillary force on a tilted cylinder: Atomic Force Microscope (AFM) measurements.

Science.gov (United States)

Kosgodagan Acharige, Sébastien; Laurent, Justine; Steinberger, Audrey

2017-11-01

The capillary force in situations where the liquid meniscus is asymmetric, such as the one around a tilted object, has been hitherto barely investigated even though these situations are very common in practice. In particular, the capillary force exerted on a tilted object may depend on the dipping angle i. We investigate experimentally the capillary force that applies on a tilted cylinder as a function of its dipping angle i, using a home-built tilting Atomic Force Microscope (AFM) with custom made probes. A micrometric-size rod is glued at the end of an AFM cantilever of known stiffness, whose deflection is measured when the cylindrical probe is dipped in and retracted from reference liquids. We show that a torque correction is necessary to understand the measured deflection. We give the explicit expression of this correction as a function of the probes' geometrical parameters, so that its magnitude can be readily evaluated. The results are compatible with a vertical capillary force varying as 1/cosi, in agreement with a recent theoretical prediction. Finally, we discuss the accuracy of the method for measuring the surface tension times the cosine of the contact angle of the liquid on the probe. Copyright © 2017 Elsevier Inc. All rights reserved.

System 800xA - a control system for the next generation of power plants; System 800xA - Das Leitsystem der naechsten Kraftwerksgeneration

Energy Technology Data Exchange (ETDEWEB)

Bruns, H. [ABB AG, Mannheim (Germany); Lauxtermann, S. [ABB AG, Minden (Germany)

2006-07-01

The system 800 x A developed by ABB is a power plant control system that is capable of combining the latest technologies in this field with best-practice solutions and integrating the I and C equipment already installed in a plant. System 800 x A offers plant owners a future-oriented integration platform for process control and sub-station control systems on the basis of the new IEC 61850 standard. Through optimised integration and networking of information in combination with direct and context-sensitive information access, decision-taking processes and the analysis of disturbances are speeded up considerably. Consistent data structures, ranging from field data to plant management data, and a simplified system configuration can reliably lower the system operating costs and increase operational reliability for a long time. This consistent technology can integrate turbine automation, unit automation, and all sorts of control functions and thus create single-source automation solutions that are highly harmonised and easy to handle. (orig.)

Effect of Pelvic Tilt and Rotation on Cup Orientation in Both Supine and Standing Positions.

Science.gov (United States)

Yun, Hohyun; Murphy, William S; Ward, Daniel M; Zheng, Guoyan; Hayden, Brett L; Murphy, Stephen B

2018-05-01

The purpose of this study is to analyze the effect of pelvic tilt and rotation on radiographic measurement of cup orientation. A total of 68 patients (79 hips) were included in this study. The patients had a computed tomography study and approximately 3 months of postoperative standing anteroposterior pelvic radiographs in both supine and standing positions. We used 2-dimensional (2D)/3-dimensional (3D) matching to measure pelvic tilt and rotation, and cup orientation. There was a wide range of pelvic tilt between individuals in both supine and standing positions. Supine pelvic tilt was different from standing pelvic tilt (P cup anteversion before and after 2D/3D matching in both supine and standing positions (P cup anteversion before and after 2D/3D matching. When all 79 hips were separated into right and left side, pelvic rotation inversely correlated with the pelvic tilt-adjusted difference in anteversion before and after 2D/3D matching of the right side but directly correlated with that of the left side in both supine and standing positions. This study demonstrated that the measurement of cup anteversion on anteroposterior radiographs is significantly affected by both pelvic tilt and pelvic rotation (depending on the side). Improved understanding of pelvic orientation and improved ability to measure pelvic orientation may eventually allow for desired cup positioning to potentially protect against complications associated with malposition of the cup. Copyright © 2017 Elsevier Inc. All rights reserved.

Perception of tilt (somatogravic illusion) in response to sustained linear acceleration during space flight

Science.gov (United States)

Clement, G.; Moore, S. T.; Raphan, T.; Cohen, B.

2001-01-01

During the 1998 Neurolab mission (STS-90), four astronauts were exposed to interaural and head vertical (dorsoventral) linear accelerations of 0.5 g and 1 g during constant velocity rotation on a centrifuge, both on Earth and during orbital space flight. Subjects were oriented either left-ear-out or right-ear-out (Gy centrifugation), or lay supine along the centrifuge arm with their head off-axis (Gz centrifugation). Pre-flight centrifugation, producing linear accelerations of 0.5 g and 1 g along the Gy (interaural) axis, induced illusions of roll-tilt of 20 degrees and 34 degrees for gravito-inertial acceleration (GIA) vector tilts of 27 degrees and 45 degrees , respectively. Pre-flight 0.5 g and 1 g Gz (head dorsoventral) centrifugation generated perceptions of backward pitch of 5 degrees and 15 degrees , respectively. In the absence of gravity during space flight, the same centrifugation generated a GIA that was equivalent to the centripetal acceleration and aligned with the Gy or Gz axes. Perception of tilt was underestimated relative to this new GIA orientation during early in-flight Gy centrifugation, but was close to the GIA after 16 days in orbit, when subjects reported that they felt as if they were 'lying on side'. During the course of the mission, inflight roll-tilt perception during Gy centrifugation increased from 45 degrees to 83 degrees at 1 g and from 42 degrees to 48 degrees at 0.5 g. Subjects felt 'upside-down' during in-flight Gz centrifugation from the first in-flight test session, which reflected the new GIA orientation along the head dorsoventral axis. The different levels of in-flight tilt perception during 0.5 g and 1 g Gy centrifugation suggests that other non-vestibular inputs, including an internal estimate of the body vertical and somatic sensation, were utilized in generating tilt perception. Interpretation of data by a weighted sum of body vertical and somatic vectors, with an estimate of the GIA from the otoliths, suggests that

Crystallographic tilt and in-plane anisotropies of an a-plane InGaN/GaN layered structure grown by MOCVD on r-plane sapphire using a ZnO buffer

International Nuclear Information System (INIS)

Liu, H F; Chi, D Z; Liu, W; Guo, S

2016-01-01

High-resolution x-ray diffraction (HRXRD) was used to investigate the crystallographic tilts and structural anisotropies in epitaxial nonpolar a-plane InGaN/GaN grown by metal–organic chemical vapor deposition on r-plane sapphire using a ZnO buffer. The substrate had an unintentional miscut of 0.14° towards its [–4 2 2 3] axis. However, HRXRD revealed a tilt of 0.26° (0.20°) between the ZnO (GaN) (11-20) and the Al 2 O 3 (1-102) atomic planes, with the (11-20) axis of ZnO (GaN) tilted towards its c-axis, which has a difference of 163° in azimuth from that of the substrate’s miscut. Excess broadenings in the GaN/ZnO (11-20) rocking curves (RCs) were observed along its c-axis. Specific analyses revealed that partial dislocations and anisotropic in-plane strains, rather than surface-related effects, wafer curvature or stacking faults, are the dominant factors for the structural anisotropy. The orientation of the partial dislocations is most likely affected by the miscut of the substrate, e.g. via tilting of the misfit dislocation gliding planes created during island coalescences. Their Burgers vector components in the growth direction, in turn, gave rise to crystallographic tilts in the same direction as that of the excess RC-broadenings. (paper)

Crystallographic tilt and in-plane anisotropies of an a-plane InGaN/GaN layered structure grown by MOCVD on r-plane sapphire using a ZnO buffer

Science.gov (United States)

Liu, H. F.; Liu, W.; Guo, S.; Chi, D. Z.

2016-03-01

High-resolution x-ray diffraction (HRXRD) was used to investigate the crystallographic tilts and structural anisotropies in epitaxial nonpolar a-plane InGaN/GaN grown by metal-organic chemical vapor deposition on r-plane sapphire using a ZnO buffer. The substrate had an unintentional miscut of 0.14° towards its [-4 2 2 3] axis. However, HRXRD revealed a tilt of 0.26° (0.20°) between the ZnO (GaN) (11-20) and the Al2O3 (1-102) atomic planes, with the (11-20) axis of ZnO (GaN) tilted towards its c-axis, which has a difference of 163° in azimuth from that of the substrate’s miscut. Excess broadenings in the GaN/ZnO (11-20) rocking curves (RCs) were observed along its c-axis. Specific analyses revealed that partial dislocations and anisotropic in-plane strains, rather than surface-related effects, wafer curvature or stacking faults, are the dominant factors for the structural anisotropy. The orientation of the partial dislocations is most likely affected by the miscut of the substrate, e.g. via tilting of the misfit dislocation gliding planes created during island coalescences. Their Burgers vector components in the growth direction, in turn, gave rise to crystallographic tilts in the same direction as that of the excess RC-broadenings.

Effects of Frequency and Motion Paradigm on Perception of Tilt and Translation During Periodic Linear Acceleration

Science.gov (United States)

Beaton, K. H.; Holly, J. E.; Clement, G. R.; Wood, Scott J.

2009-01-01

Previous studies have demonstrated an effect of frequency on the gain of tilt and translation perception. Results from different motion paradigms are often combined to extend the stimulus frequency range. For example, Off-Vertical Axis Rotation (OVAR) and Variable Radius Centrifugation (VRC) are useful to test low frequencies of linear acceleration at amplitudes that would require impractical sled lengths. The purpose of this study was to compare roll-tilt and lateral translation motion perception in 12 healthy subjects across four paradigms: OVAR, VRC, sled translation and rotation about an earth-horizontal axis. Subjects were oscillated in darkness at six frequencies from 0.01875 to 0.6 Hz (peak acceleration equivalent to 10 deg, less for sled motion below 0.15 Hz). Subjects verbally described the amplitude of perceived tilt and translation, and used a joystick to indicate the direction of motion. Consistent with previous reports, tilt perception gain decreased as a function of stimulus frequency in the motion paradigms without concordant canal tilt cues (OVAR, VRC and Sled). Translation perception gain was negligible at low stimulus frequencies and increased at higher frequencies. There were no significant differences between the phase of tilt and translation, nor did the phase significantly vary across stimulus frequency. There were differences in perception gain across the different paradigms. Paradigms that included actual tilt stimuli had the larger tilt gains, and paradigms that included actual translation stimuli had larger translation gains. In addition, the frequency at which there was a crossover of tilt and translation gains appeared to vary across motion paradigm between 0.15 and 0.3 Hz. Since the linear acceleration in the head lateral plane was equivalent across paradigms, differences in gain may be attributable to the presence of linear accelerations in orthogonal directions and/or cognitive aspects based on the expected motion paths.

Tilt measurements at Vulcano Island

OpenAIRE

B. Saraceno; G. Laudani; F. Guglielmino; A. Ferro; G. Falzone; O. Campisi; S. Gambino

2007-01-01

A network of tiltmeters has been operational on Vulcano Island for numerous years. At present, the network comprises five functioning borehole stations, four of which are installed at 8-10 m and allow recording very stable, high precision signals with very low noise. We report observations over the last 12 years that illustrate impulsive variations linked to seismicity and long-term (several years) trends in the signals. We suggest a relationship between tilt changes correlated to the stro...

Intrinsic stability of ferroelectric and piezoelectric properties of epitaxial PbZr0.45Ti0.55O3 thin films on silicon in relation to grain tilt

Directory of Open Access Journals (Sweden)

Evert P Houwman, Minh D Nguyen, Matthijn Dekkers and Guus Rijnders

2013-01-01

Full Text Available Piezoelectric thin films of PbZr0.45Ti0.55O3 were grown on Si substrates in four different ways, resulting in different crystalline structures, as determined by x-ray analysis. The crystalline structures were different in the spread in tilt angle and the in-plane alignment of the crystal planes between different grains. It is found that the deviations of the ferroelectric polarization loop from that of the ideal rectangular loop (reduction of the remanent polarization with respect to the saturation polarization, dielectric constant of the film, slanting of the loop, coercive field value all scale with the average tilt angle. A model is derived based on the assumption that the tilted grain boundaries between grains affect the film properties locally. This model describes the observed trends. The effective piezoelectric coefficient d33,eff shows also a weak dependence on the average tilt angle for films grown in a single layer, whereas it is strongly reduced for the films deposited in multiple layers. The least affected properties are obtained for the most epitaxial films, i.e. grown on a SrTiO3 epitaxial seed layer, by pulsed laser deposition. These films are intrinsically stable and do not require poling to acquire these stable properties.

Estimating 3D tilt from local image cues in natural scenes

OpenAIRE

Burge, Johannes; McCann, Brian C.; Geisler, Wilson S.

2016-01-01

Estimating three-dimensional (3D) surface orientation (slant and tilt) is an important first step toward estimating 3D shape. Here, we examine how three local image cues from the same location (disparity gradient, luminance gradient, and dominant texture orientation) should be combined to estimate 3D tilt in natural scenes. We collected a database of natural stereoscopic images with precisely co-registered range images that provide the ground-truth distance at each pixel location. We then ana...

Non-uniform-tilt-modulated fiber Bragg grating for temperature-immune micro-displacement measurement

International Nuclear Information System (INIS)

Guo, Tuan; Chen, Chengkun; Albert, Jacques

2009-01-01

Temperature-immune micro-displacement measurement is demonstrated by using a Gaussian-chirped tilted fiber Bragg grating (TFBG). The internal tilt angles of the sensing TFBG are effectively modulated via a displacement-induced Gaussian-strain-gradient along the specially designed bending cantilever beam. The phase mismatch between different effective pitches and tilt angles weakens the core-to-cladding mode coupling as the beam is displaced. While the power of the ghost mode resonance in transmission shows a strong sensitivity to the displacement, it is immune from spatially uniform temperature changes. Ghost-power-referenced displacement measurement and temperature-insensitive property are experimentally achieved for this cost-effective sensing device

Experimental study on the effect of heat flux tilt on rod bundle dryout limitation

Energy Technology Data Exchange (ETDEWEB)

Sugawara, S; Terunuma, K; Kamoshida, H [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1996-12-31

The effect of heat flux tilt on rod bundle dryout limitation was studied experimentally using a full-scale mock-up test facility and simulated 36-rod fuel bundles in which heater pins have azimuthal nonuniform heat flux distribution (i.e., heat flux tilt). Experimental results for typical lateral power distribution in the bundle indicate that the bundle dryout power with azimuthal heat flux tilt is higher than that without azimuthal heat flux tilt in the entire experimental range. Consequently, it is concluded that the dryout experiment using the test bundle with heater pins which has circumferentially uniform heat flux distribution gives conservative results for the usual lateral power distribution in a bundle in which the relative power of outermost-circle fuel rods is higher than those of middle- and inner-circle ones. (author). 15 refs., 2 tabs., 8 figs.

Impact of Mechanical down Tilt and Height on the Pilot Coverage of UMTS Networks

Directory of Open Access Journals (Sweden)

N. Faruk

2012-06-01

Full Text Available The task of planning a network can be very challenging as it involves many careful studies with a lot of considerations and, at times, trial and error. In this paper, the impacts of antenna mechanical down tilt and antenna height on UMTS network performance are studied. First, we used ASSET3G simulation software to design 3G pilot coverage. Optimization techniques were deployed to study the performance of the network. Simulation results show about 2.6% increase in the coverage area when the antenna height was increased from 15 m to 25 m at the same tilt angle of 0 ° The coverage drops by 24% when transiting from 0° to 6° tilt angle was made for 15 m height antenna. The results also indicated that, pilot pollution could be reduced by choosing optimum down tilt angle.

Process, Design and Materials for Unidirectionally Tilted Polymeric Micro/Nanohairs and Their Adhesion Characteristics

Directory of Open Access Journals (Sweden)

Hyeon Seong Im

2016-09-01

Full Text Available Recent research in the field of gecko-inspired dry adhesive has focused on modifying the material and structural properties of polymer-based nanohairs. Polymers such as polystyrene (PS, high-density polyethylene (HDPE, ultraviolet curable epoxy (SU-8, polyurethane acrylate (PUA, polycarbonate (PC, and polydimethyl siloxane (PDMS can fulfill many mechanical property requirements, are easily tunable, and can be produced via large-scale fabrication. However, the fabrication process for tilted structure remains challenging. The tilted structure is a crucial factor in high-degree conformal contact, which facilitates high adhesion, low effective modulus, and directional adhesion properties. Recent studies have attempted to create a tilted structure by applying beam irradiation, mechanical and thermal stress, and magnetic fields. This review provides a comprehensive investigation into advanced strategies for producing tilted polymeric nanostructures and their potential applications in the near future.

Properties of HTS YBCO thin films deposited on tilted NdGaO3 substrates

International Nuclear Information System (INIS)

Nurgaliev, T.; Donchev, T.; Mateev, E.; Miteva, S.; Mozhaev, P.B.; Mozhaeva, J.E.

2005-01-01

Thin YBa 2 Cu 3 O 7 films were fabricated by 2-opposed DC magnetron sputtering onto NdGaO 3 substrates, tilted from standard (1 1 0) orientation by 0-26 deg , and their surface morphology and electrical characteristics were investigated. Normal state resistivity (at 295 K) and microwave surface resistance (at 77 K and ∼8 GHz) of the films demonstrated anisotropy, introduced by the tilted substrate, and some improvement of the superconducting parameters of the films was observed at small tilt angles (θ ∼ 1.5-3 deg ). The increase of the microwave surface resistance at high tilt angles for the current tracks, perpendicular to the steps of the substrate, was described in the framework of a simple model, which takes into account the complex conductivity of the film and the weak links between the film terraces

Experimental study on the effect of heat flux tilt on rod bundle dryout limitation

International Nuclear Information System (INIS)

Sugawara, S.; Terunuma, K.; Kamoshida, H.

1995-01-01

The effect of heat flux tilt on rod bundle dryout limitation was studied experimentally using a full-scale mock-up test facility and simulated 36-rod fuel bundles in which heater pins have azimuthal nonuniform heat flux distribution (i.e., heat flux tilt). Experimental results for typical lateral power distribution in the bundle indicate that the bundle dryout power with azimuthal heat flux tilt is higher than that without azimuthal heat flux tilt in the entire experimental range. Consequently, it is concluded that the dryout experiment using the test bundle with heater pins which has circumferentially uniform heat flux distribution gives conservative results for the usual lateral power distribution in a bundle in which the relative power of outermost-circle fuel rods is higher than those of middle- and inner-circle ones. (author). 15 refs., 2 tabs., 8 figs

Spontaneous tilting after placement of the gunther-tulip inferior vena caval filter: a case report

International Nuclear Information System (INIS)

Seo, Tae Seok; Cha, In Ho; Seol, Hae Young; Park, Cheol Min

2006-01-01

Tilting of a deployed filter in the inferior vena cava (IVC) is a particular kind of periprocedural complication and this can reduce the filter's clot-trapping ability and increase the occlusion of the IVC at a later period. The authors report here on a case of spontaneous tilting of an inferior vena caval filter that was associated with thrombosis in the IVC within 2 weeks of the initially successful placement of the filter without tilting

Zure depositie in Nederland: Scenarioresultaten voor 1994 en 2000

NARCIS (Netherlands)

Schutter MAA; de Leeuw FAAM

1991-01-01

By means of an atmospheric transport model estimates have been made of the total potential acid deposition in the Netherlands for the years 1980, 1985, 1994 and 2000. Spatial resolution of the calculation was 5 x 5 km2. Emission inventories appied for 1994 and 2000 are based on the emission

Keblish's lateral surgical approach enhances patellar tilt in valgus knee arthroplasty

Directory of Open Access Journals (Sweden)

José Roberto Tonelli Filho

Full Text Available ABSTRACT OBJECTIVE: To compare the clinical and radiological outcomes of conventional medial and lateral approaches for total knee replacement in the valgus osteoarthritic knee. METHODS: In this randomized controlled trial, 21 patients with valgus knee osteoarthritis were randomized to total knee replacement through medial or lateral approach. The primary outcome was radiographic patellar tilt. Secondary outcomes were visual analog scale of pain, postoperative levels of hemoglobin, and clinical aspect of the operative wound. RESULTS: There were no differences between the groups regarding other clinical variables. Mean lateral tilt of the patella was 3.1 degrees (SD ± 5.3 in the lateral approach group and 18 degrees (SD ± 10.2 in the medial approach group (p = 0.02. There were no differences regarding the secondary outcomes. CONCLUSION: Lateral approach provided better patellar tilt following total knee replacement in valgus osteoarthritic knee.

Tilt measurement using inclinometer based on redundant configuration of MEMS accelerometers

Science.gov (United States)

Lu, Jiazhen; Liu, Xuecong; Zhang, Hao

2018-05-01

Inclinometers are widely used in tilt measurement and their required accuracy is becoming ever higher. Most existing methods can effectively work only when the tilt is less than 60°, and the accuracy still can be improved. A redundant configuration of micro-electro mechanical system accelerometers is proposed in this paper and a least squares method and data processing normalization are used. A rigorous mathematical derivation is given. Simulation and experiment are used to verify its feasibility. The results of a Monte Carlo simulation, repeated 3000 times, and turntable reference experiments have shown that the tilt measure range can be expanded to 0°–90° by this method and that the measurement accuracy of θ can be improved by more than 10 times and the measurement accuracy of γ can be also improved effectively. The proposed method is proved to be effective and significant in practical application.

Free and localised exciton of ternary nanocrystals in CsX-PbX.sub.2./sub. thin films (X= Cl, Br, I)

Czech Academy of Sciences Publication Activity Database

Somma, E.; Aloe, P.; Mastro, Lo S.; Giampaolo, C.; Nikl, Martin; Nitsch, Karel; Fabeni, P.; Pazzi, G.P.

2001-01-01

Roč. 156, 1-4 (2001), s. 103-107 ISSN 1042-0150. [International Conference on Defects in Insulating Materials /14./. Johannesburg, 03.04.2000-07.04.2000] Institutional research plan: CEZ:AV0Z1010914 Keywords : CsPbX 3 * CsPbX 6 * nanoaggregates * XRD * absorption * luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.380, year: 2001

Perceived direction of gravity and the body-axis during static whole body roll-tilt in healthy subjects.

Science.gov (United States)

Tamura, Atsushi; Wada, Yoshiro; Inui, Takuo; Shiotani, Akihiro

2017-10-01

We used the subjective visual vertical (SVV) and two different subjective visual body axis (SVBA) methods to quantify roll-tilt perception under gravity, and investigated the characteristics of these methods during static roll-tilt. In addition, we independently developed a compact device to facilitate evaluation of SVBA in different gravitational environments. Ten male volunteers participated in this study. We created a roll-tilt environment using a flight simulator in a dark room. The cockpit of the simulator was tilted leftward or rightward (-30°, -20°, -10°, 0°, 10°, 20° and 30°) in each randomly ordered trial. We quantified roll-tilt perception such that the experiment was conducted under 21 different conditions per participant. We found no significant differences among the SVV error and the two types of SVBA error. The SVV and the SVBA methods may be useful for evaluating subjective roll-tilt perception.

Final Report-Confirmatory Survey Results for the ABB Combustion Engineering Site, Windsor, Connecticut; Revision 1 (DCN 5158-SR-02-1) (Docket No. 030-03754; RFTA No. 12-003)

Energy Technology Data Exchange (ETDEWEB)

ADAMS, WADE C

2013-01-28

The objectives of the confirmatory activities were to provide independent contractor field data reviews and to generate independent radiological data for use by the NRC in evaluating the adequacy and accuracy of the contractor's procedures and FSS results. ORAU reviewed ABB CE's decommissioning plan, final status survey plan, and the applicable soil DCGLs, which were developed based on an NRC-approved radiation dose assessment. The surveys included gamma surface scans, gamma direct measurements, and soil sampling.

Crustal-scale tilting of the central Salton block, southern California

Science.gov (United States)

Dorsey, Rebecca; Langenheim, Victoria

2015-01-01

The southern San Andreas fault system (California, USA) provides an excellent natural laboratory for studying the controls on vertical crustal motions related to strike-slip deformation. Here we present geologic, geomorphic, and gravity data that provide evidence for active northeastward tilting of the Santa Rosa Mountains and southern Coachella Valley about a horizontal axis oriented parallel to the San Jacinto and San Andreas faults. The Santa Rosa fault, a strand of the San Jacinto fault zone, is a large southwest-dipping normal fault on the west flank of the Santa Rosa Mountains that displays well-developed triangular facets, narrow footwall canyons, and steep hanging-wall alluvial fans. Geologic and geomorphic data reveal ongoing footwall uplift in the southern Santa Rosa Mountains, and gravity data suggest total vertical separation of ∼5.0–6.5 km from the range crest to the base of the Clark Valley basin. The northeast side of the Santa Rosa Mountains has a gentler topographic gradient, large alluvial fans, no major active faults, and tilted inactive late Pleistocene fan surfaces that are deeply incised by modern upper fan channels. Sediments beneath the Coachella Valley thicken gradually northeast to a depth of ∼4–5 km at an abrupt boundary at the San Andreas fault. These features all record crustal-scale tilting to the northeast that likely started when the San Jacinto fault zone initiated ca. 1.2 Ma. Tilting appears to be driven by oblique shortening and loading across a northeast-dipping southern San Andreas fault, consistent with the results of a recent boundary-element modeling study.

Spontaneous tilting after placement of the gunther-tulip inferior vena caval filter: a case report

Energy Technology Data Exchange (ETDEWEB)

Seo, Tae Seok; Cha, In Ho; Seol, Hae Young; Park, Cheol Min [Guro Hospital, Korea University College of Medicine, Seoul (Korea, Republic of)

2006-10-15

Tilting of a deployed filter in the inferior vena cava (IVC) is a particular kind of periprocedural complication and this can reduce the filter's clot-trapping ability and increase the occlusion of the IVC at a later period. The authors report here on a case of spontaneous tilting of an inferior vena caval filter that was associated with thrombosis in the IVC within 2 weeks of the initially successful placement of the filter without tilting.

Demonstration of natural gas reburn for NO{sub x} emissions reduction at Ohio Edison Company`s cyclone-fired Niles Plant Unit Number 1

Energy Technology Data Exchange (ETDEWEB)

Borio, R.W.; Lewis, R.D.; Koucky, R.W. [ABB Power Plant Labs., Windsor, CT (United States); Lookman, A.A. [Energy Systems Associates, Pittsburgh, PA (United States); Manos, M.G.; Corfman, D.W.; Waddingham, A.L. [Ohio Edison, Akron, OH (United States); Johnson, S.A. [Quinapoxet Engineering Solutions, Inc., Windham, NH (United States)

1996-04-01

Electric utility power plants account for about one-third of the NO{sub x} and two-thirds of the SO{sub 2} emissions in the US cyclone-fired boilers, while representing about 9% of the US coal-fired generating capacity, emit about 14% of the NO{sub x} produced by coal-fired utility boilers. Given this background, the Environmental Protection Agency, the Gas Research Institute, the Electric Power Research Institute, the Pittsburgh Energy Technology Center, and the Ohio Coal Development Office sponsored a program led by ABB Combustion Engineering, Inc. (ABB-CE) to demonstrate reburning on a cyclone-fired boiler. Ohio Edison provided Unit No. 1 at their Niles Station for the reburn demonstration along with financial assistance. The Niles Unit No. 1 reburn system was started up in September 1990. This reburn program was the first full-scale reburn system demonstration in the US. This report describes work performed during the program. The work included a review of reburn technology, aerodynamic flow model testing of reburn system design concepts, design and construction of the reburn system, parametric performance testing, long-term load dispatch testing, and boiler tube wall thickness monitoring. The report also contains a description of the Niles No. 1 host unit, a discussion of conclusions and recommendations derived from the program, tabulation of data from parametric and long-term tests, and appendices which contain additional tabulated test results.

VARIABILITY FROM NON-AXISYMMETRIC FLUCTUATIONS INTERACTING WITH STANDING SHOCKS IN TILTED BLACK HOLE ACCRETION DISKS

Energy Technology Data Exchange (ETDEWEB)

Henisey, Ken B. [Natural Science Division, Pepperdine University, Malibu, CA 90263 (United States); Blaes, Omer M. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Fragile, P. Chris [Department of Physics and Astronomy, College of Charleston, Charleston, SC 29424 (United States)

2012-12-10

We study the spatial and temporal behavior of fluid in fully three-dimensional, general relativistic, magnetohydrodynamical simulations of both tilted and untilted black hole accretion flows. We uncover characteristically greater variability in tilted simulations at frequencies similar to those predicted by the formalism of trapped modes, but ultimately conclude that its spatial structure is inconsistent with a modal interpretation. We find instead that previously identified, transient, overdense clumps orbiting on roughly Keplerian trajectories appear generically in our global simulations, independent of tilt. Associated with these fluctuations are acoustic spiral waves interior to the orbits of the clumps. We show that the two non-axisymmetric standing shock structures that exist in the inner regions of these tilted flows effectively amplify the variability caused by these spiral waves to markedly higher levels than in untilted flows, which lack standing shocks. Our identification of clumps, spirals, and spiral-shock interactions in these fully general relativistic, magnetohydrodynamical simulations suggests that these features may be important dynamical elements in models that incorporate tilt as a way to explain the observed variability in black hole accretion flows.

X-ray apparatus

International Nuclear Information System (INIS)

Tomita, Chuji.

1980-01-01

A principal object of the present invention is to provide an X-ray apparatus which is such that the distance between the surface of the patient's table and the floor on which the apparatus is installed is sufficiently small in the horizontal position of the patient's table of the roentgenographical pedestal and that the rotation of the pedestal from the horizontal position to a tilted position and further to the vertical position of the table can be carried out smoothly. (auth)

X-ray astronomy 2000: Wide field X-ray monitoring with lobster-eye telescopes

International Nuclear Information System (INIS)

Inneman, A.; Hudec, R.; Pina, L.; Gorenstein, P.

2001-01-01

The recently available first prototypes of innovative very wide field X-ray telescopes of Lobster-Eye type confirm the feasibility to develop such flight instruments in a near future. These devices are expected to allow very wide field (more than 1000 square degrees) monitoring of the sky in X-rays (up to 10 keV and perhaps even more) with faint limits. We will discuss the recent status of the development of very wide field X-ray telescopes as well as related scientific questions including expected major contributions such as monitoring and study of X-ray afterglows of Gamma Ray Bursts

Tilting-Pad Guide Bearing in Large Hydro-unit

Directory of Open Access Journals (Sweden)

Li-Feng Ma

2000-01-01

Full Text Available A new numerical method is proposed for predicting the nonlinearity of tilting-pad guide bearing oilfilm force in the rotor-bearing system in a large hydro-unit. Nonlinear displacement and velocity of the journal center, as well as nonlinear tilting angles and angular velocities of the pads in non-stationary Reynolds equation are taken into account. This method is also suited for other small rotor-bearing system. As an example, the response due to a momentarily created unbalance is Calculated. The nonlinear motion patterns of the pad and journal whirling orbit are obtained. Finally, the nonlinear orbit is compared to the linear one that could be calculated from linear stiffness and damping coefficients. It is shown that there are important differences between those two orbits and that the nonlinear simulation is more accurate.

On the Design of Tilting-Pad Thrust Bearings

DEFF Research Database (Denmark)

Heinrichson, Niels

2007-01-01

Pockets are often machined in the surfaces of tilting-pad thrust bearings to allow for hydrostatic jacking in the start-up phase. Pockets and other recesses in the surfaces of bearing pads influence the pressure distribution and thereby the position of the pivot resulting in the most advantageous...... based on the Reynolds equation are used. They include the effects of variations of viscosity with temperature and the deformation of the bearing pads due to pressure and thermal gradients. The models are validated using measurements. Tilting-pad bearings of standard design are studied and the influences...... of the friction loss. Both this bearing and the bearing design with enclosed recesses in the high-pressure regions of the pads suffer from a higher sensitivity to the position of the pivot. The design of such bearing is therefore no trivial task....

Numerical study of crucial parameters in tilt casting for titanium aluminides

Directory of Open Access Journals (Sweden)

Hong Wang

2011-08-01

Full Text Available Numerical modeling of the tilt casting process for TiAl alloys was investigated to achieve a tranquil mould filling and TiAl castings free of defects. Titanium alloys are very reactive in molten state, so they are widely melted in cold crucible, e.g. the Induction Skull Melting (ISM furnace. Then the crucible holding the molten metal together with the mould is rotated to transfer the metal into the mould — ISM+ tilt casting. This paper emphasizes the effect of crucial parameters on mould filling and solidification of the castings during tilt casting. All crucial parameters, such as rotation rate, rotation profile, venting, initial mould temperature, casting orientation, feeder design, change of radius in 'T' junction and mould insulation have been discussed using numerical modeling data. Simulations were performed using a 3D CFD code PHYSICA implemented with front tracking, heat transfer algorithms and a turbulence model (which accounts for an advancing solid front.

CONTRIBUTION OF QUADRATIC RESIDUE DIFFUSERS TO EFFICIENCY OF TILTED PROFILE PARALLEL HIGHWAY NOISE BARRIERS

Directory of Open Access Journals (Sweden)

M. R. Monazzam ، P. Nassiri

2009-10-01

Full Text Available This paper presents the results of an investigation on the acoustic performance of tilted profile parallel barriers with quadratic residue diffuser (QRD tops and faces. A 2D boundary element method (BEM is used to predict the barrier insertion loss. The results of rigid and with absorptive coverage are also calculated for comparisons. Using QRD on the top surface and faces of all tilted profile parallel barrier models introduced here is found to improve the efficiency of barriers compared with rigid equivalent parallel barrier at the examined receiver positions. Applying a QRD with frequency design of 400 Hz on 5 degrees tilted parallel barrier improves the overall performance of its equivalent rigid barrier by 1.8 dB(A. Increase in the treated surfaces with reactive elements shifts the effective performance toward lower frequencies. It is found that by tilting the barriers from 0 to 10 degrees in parallel set up, the degradation effects in parallel barriers is reduced but the absorption effect of fibrous materials and also diffusivity of the quadratic residue diffuser is reduced significantly. In this case all the designed barriers have better performance with 10 degrees tilting in parallel set up. The most economic traffic noise parallel barrier which produces significantly high performance, is achieved by covering the top surface of the barrier closed to the receiver by just a QRD with frequency design of 400 Hz and tilting angle of 10 degrees. The average A-weighted insertion loss in this barrier is predicted to be 16.3 dB (A.

On the effect of cover tilt angle of the simple solar still on its productivity in different seasons and latitudes

International Nuclear Information System (INIS)

Khalifa, Abdul Jabbar N.

2011-01-01

Many experimental and numerical studies have been carried out on different configurations of solar stills to optimize the design by investigating the effect of climatic, operational and design parameters on its performance. One of the main parameters that have received a considerable attention is the cover tilt angle. A large number of studies on the effect of cover tilt angle on productivity in different seasons and latitude angles are cited in this article. The investigation that tackle the detailed effect of the cover tilt angle on productivity report contradictory conclusions about the effect of tilt angle on productivity and the value of the optimum tilt angle. A relation between the cover tilt angle and productivity of simple solar still in various seasons is established together with a relation between the optimum tilt angle and the latitude angle by an extensive review of the literature. The conclusions of this study should assist in choosing the proper cover tilt angle in various seasons and latitudes.

CFD calculations on the unsteady aerodynamic characteristics of a tilt-rotor in a conversion mode

Directory of Open Access Journals (Sweden)

Li Peng

2015-12-01

Full Text Available In order to calculate the unsteady aerodynamic characteristics of a tilt-rotor in a conversion mode, a virtual blade model (VBM and an real blade model (RBM are established respectively. A new multi-layer moving-embedded grid technique is proposed to reduce the numerical dissipation of the tilt-rotor wake in a conversion mode. In this method, a grid system generated abound the rotor accounts for rigid blade motions, and a new searching scheme named adaptive inverse map (AIM is established to search corresponding donor elements in the present moving-embedded grid system to translate information among the different computational zones. A dual-time method is employed to fulfill unsteady calculations on the flowfield of the tilt-rotor, and a second-order centered difference scheme considering artificial viscosity is used to calculate the flux. In order to improve the computing efficiency, the single program multiple data (SPMD model parallel acceleration technology is adopted, according to the characteristic of the current grid system. The lift and drag coefficients of an NACA0012 airfoil, the dynamic pressure distributions below a typical rotor plane, and the sectional pressure distributions on a three-bladed Branum–Tung tilt-rotor in hover flight are calculated respectively, and the present VBM and RBM are validated by comparing the calculated results with available experimental data. Then, unsteady aerodynamic forces and flowfields of an XV-15 tilt-rotor in different modes, such as a fixed conversion mode at different tilt angles (15°, 30°, 60° and a whole conversion mode which converses from 0° to 90°, are numerically simulated by the VBM and RBM respectively. By analyses and comparisons on the simulated results of unsteady aerodynamic forces of the tilt-rotor in different modes, some meaningful conclusions about distorted blade-tip vortex distribution and unsteady aerodynamic force variation in a conversion mode are obtained, and these

Vibrotactile tilt feedback improves dynamic gait index: a fall risk indicator in older adults.

Science.gov (United States)

Wall, Conrad; Wrisley, Diane M; Statler, Kennyn D

2009-07-01

The purpose of this study was to determine the effectiveness of vibrotactile feedback of body tilt in improving dynamic gait index (DGI) a fall risk indicator in community dwelling older adults. Twelve healthy elderly subjects (three males and nine females, age 79.7+/-5.4 yrs) were tested in an institutional balance rehabilitation laboratory to investigate changes between the feedback off and on conditions. Subjects were acutely exposed to a vibrotactile display that indicated the magnitude and direction of their body tilt from the vertical. DGI and mediolateral (ML) sway were determined during locomotion with, and without, vibrotactile tilt feedback (VTTF). All subjects were at risk for falls based on their initial DGI Score (range: 15-19, mean 17.4+/-1.56), which was taken with the vibratory stimulus turned off. Subjects learned to use the trunk tilt information from the vibrotactile feedback vest through 20-30 min of gait and balance training consisting of activities that challenged their balance. Subjects were then retested on the DGI. Statistically significant changes were demonstrated for the DGI total score while using the vibrotactile tilt feedback. DGI total scores improved from 17.1+/-0.4 to 20.8+/-0.3 (pfall risk indicators for this population.

Is neck tilt and shoulder imbalance the same phenomenon? A prospective analysis of 89 adolescent idiopathic scoliosis patients (Lenke type 1 and 2).

Science.gov (United States)

Kwan, Mun Keong; Wong, Kai Ann; Lee, Chee Kean; Chan, Chris Yin Wei

2016-02-01

To introduce a new clinical neck tilt grading and to investigate clinically and radiologically whether neck tilt and shoulder imbalance is the same phenomenon in AIS patients. 89 AIS Lenke 1 and 2 cases were assessed prospectively using the new clinical neck tilt grading. Shoulder imbalance and neck tilt were correlated with coracoid height difference (CHD), clavicle\\rib intersection distance (CRID), clavicle angle (CA), radiographic shoulder height (RSH), T1 tilt and cervical axis. Mean age was 17.2 ± 3.8 years old. 66.3 % were Lenke type 1 and 33.7 % were type 2 curves. Strong intraobserver (0.79) and interobserver (0.75) agreement of the clinical neck tilt grading was noted. No significant correlation was observed between clinical neck tilt and shoulder imbalance (0.936). 56.3 % of grade 3 neck tilt, 50.0 % grade 2 neck tilt patients had grade 0 shoulder imbalance. In patients with grade 2 shoulder imbalance, 42.9 % had grade 0, 35.7 % grade 1, 14.3 % grade 2 and only 7.1 % had grade 3 neck tilt. CHD, CRID, CA and RSH correlated with shoulder imbalance. T1 tilt and cervical axis measurements correlated with neck tilt. In conclusion, neck tilt is distinct from shoulder imbalance. Clinical neck tilt has poor correlation with clinical shoulder imbalance. Clinical neck tilt grading correlated with cervical axis and T1 tilt whereas clinical shoulder grading correlated with CHD, RSH CRID and CA.

Critical bias fields for tilting stability in the BETA-II experiment

International Nuclear Information System (INIS)

Dalhed, H.E.

1981-01-01

The PEST equilibrium code and the GATO ideal MHD stability code have been modified to study stability properties of Spheromak configurations. Of particular interest is the effect on tilting modes of perfectly conducting walls which do not link the plasma. This paper makes use of equilibria and conducting walls specifically designed to model the BETA-II experiment at LLNL. Onset of the tilting mode is determined as a function of the bias magnetic field. Comparison with available experimental data shows promising agreement with the numerical results

Determination of the Basic Friction Angle of Rock Surfaces by Tilt Tests

Science.gov (United States)

Jang, Hyun-Sic; Zhang, Qing-Zhao; Kang, Seong-Seung; Jang, Bo-An

2018-04-01

Samples of Hwangdeung granite from Korea and Berea sandstone from USA, both containing sliding planes, were prepared by saw-cutting or polishing using either #100 or #600 grinding powders. Their basic friction angles were measured by direct shear testing, triaxial compression testing, and tilt testing. The direct shear tests and triaxial compression tests on the saw-cut, #100, and #600 surfaces indicated that the most reliable results were obtained from the #100 surface: basic friction angle of 29.4° for granite and 34.1° for sandstone. To examine the effect of surface conditions on the friction angle in tilt tests, the sliding angles were measured 50 times with two surface conditions (surfaces cleaned and not cleaned after each measurement). The initial sliding angles were high regardless of rock type and surface conditions and decreased exponentially as measurements continued. The characteristics of the sliding angles, differences between tilt tests, and dispersion between measurements in each test indicated that #100 surface produced the most reliable basic friction angle measurement. Without cleaning the surfaces, the average angles for granite (32 measurements) and sandstone (23 measurements) were similar to the basic friction angle. When 20-50 measurements without cleaning were averaged, the basic friction angle was within ± 2° for granite and ± 3° for sandstone. Sliding angles using five different tilting speeds were measured but the average was similar, indicating that tilting speed (between 0.2° and 1.6°/s) has little effect on the sliding angle. Sliding angles using four different sample sizes were measured with the best results obtained for samples larger than 8 × 8 cm.

An Online Tilt Estimation and Compensation Algorithm for a Small Satellite Camera

Science.gov (United States)

Lee, Da-Hyun; Hwang, Jai-hyuk

2018-04-01

In the case of a satellite camera designed to execute an Earth observation mission, even after a pre-launch precision alignment process has been carried out, misalignment will occur due to external factors during the launch and in the operating environment. In particular, for high-resolution satellite cameras, which require submicron accuracy for alignment between optical components, misalignment is a major cause of image quality degradation. To compensate for this, most high-resolution satellite cameras undergo a precise realignment process called refocusing before and during the operation process. However, conventional Earth observation satellites only execute refocusing upon de-space. Thus, in this paper, an online tilt estimation and compensation algorithm that can be utilized after de-space correction is executed. Although the sensitivity of the optical performance degradation due to the misalignment is highest in de-space, the MTF can be additionally increased by correcting tilt after refocusing. The algorithm proposed in this research can be used to estimate the amount of tilt that occurs by taking star images, and it can also be used to carry out automatic tilt corrections by employing a compensation mechanism that gives angular motion to the secondary mirror. Crucially, this algorithm is developed using an online processing system so that it can operate without communication with the ground.

Structural analysis of a flexure tilt table by using finite element method; Strukturanalyse eines Biege-Kipp-Tisches mittels Finite-Elemente-Methode

Energy Technology Data Exchange (ETDEWEB)

Schust, Matthias

2012-08-15

At the research institute DESY the synchrotron radiation source PETRA III is operated at Hamburg site. The facility is the most powerful lightsource of its kind and enables scientists to use X-ray beams with hitherto unattained brilliance. In a so-called double-crystal monochromator certain wavelengths can be selected from the light. In these systems tilt tables with flexure hinges are used. So far, a certain susceptibility of the assembly to vibration can be seen, which decreases the beam quality. The goal of this thesis is to determine the causes of the problem and to discuss the findings concerning the known behavior. First of all the functioning of the tilt table will be explained. Afterwards the theory of flexure hinges and the boundary conditions of a finite element analysis will be treated. Using a simulation program, several assembly models will be investigated and parameter studies are carried out. Beginning with the base object of investigation - the tilt table - the model of the whole assembly is systematically developed. Natural frequencies, the stress at the spring hinges and the displacement of the crystal surface can be determined. The results of the research show that the vibration behavior of the assembly is very complex and cannot be comprehensively described within the analyses carried out. The cause of the problems has not been identified yet and therefore further studies would be necessary. (orig.)

Tilt engineering of exchange coupling at G-type SrMnO3/(La,Sr)MnO3 interfaces

Science.gov (United States)

Li, F.; Song, C.; Wang, Y. Y.; Cui, B.; Mao, H. J.; Peng, J. J.; Li, S. N.; Wang, G. Y.; Pan, F.

2015-11-01

With the recent realization of hybrid improper ferroelectricity and room-temperature multiferroic by tilt engineering, “functional” octahedral tilting has become a novel concept in multifunctional perovskite oxides, showing great potential for property manipulation and device design. However, the control of magnetism by octahedral tilting has remained a challenging issue. Here a qualitative and quantitative tilt engineering of exchange coupling, one of the magnetic properties, is demonstrated at compensated G-type antiferromagnetic/ferromagnetic (SrMnO3/La2/3Sr1/3MnO3) interfaces. According to interfacial Hamiltonian, exchange bias (EB) in this system originates from an in-plane antiphase rotation (a-) in G-type antiferromagnetic layer. Based on first-principles calculation, tilt patterns in SrMnO3 are artificially designed in experiment with different epitaxial strain and a much stronger EB is attained in the tensile heterostructure than the compressive counterpart. By controlling the magnitude of octahedral tilting, the manipulation of exchange coupling is even performed in a quantitative manner, as expected in the theoretical estimation. This work realized the combination of tilt engineering and exchange coupling, which might be significant for the development of multifunctional materials and antiferromagnetic spintronics.

A computer simulation study of tilted smectic mesophases

International Nuclear Information System (INIS)

Withers, I.M.

2000-05-01

Results are presented from a series of simulations undertaken to determine the effect of a novel form of molecular biaxiality upon the phase behaviour of the well established Gay-Berne (GB) liquid crystal model. Firstly, the simulation of a bulk system interacting via the Internally-Rotated Gay Berne (IRGB) potential, which offers a single-site representation of a molecule rigidly constrained into a zig-zag conformation, is presented. The results of simulations performed for systems of IRGB particles with an aspect ratio of 3:1 confirm that the introduction of biaxiality into the model results in the destabilisation of the orientationally ordered phases. For particles with a sufficiently pronounced zig-zag conformation, this results in the complete destabilisation of the smectic A phase and the smectic B phase being replaced by the tilted smectic J phase. Following these observations, the effect upon the phase behaviour of increasing molecular elongation is also considered, with an increase in the aspect ratio from 3:1 to 4:1 resulting in the nematic and smectic J phases being replaced by smectic A and smectic G phases respectively. Secondly, a version of the IRGB potential modified to include a degree of molecular flexibility is considered. Results obtained from bulk systems interacting via the flexible IRGB for 3:1 and 4:1 molecules show that the introduction of flexibility results in the destabilisation of the smectic A phase and the stabilisation of the nematic and tilted hexatic phases. Finally, the effect upon the phase behaviour of the rigid IRGB model of the inclusion of a longitudinal linear quadrupole is examined. These results show that increasing quadrupole moment results in the destabilisation of the tilted hexatic phase, although the biaxial order parameter is increased with increasing quadrupole moment. There is no clear correlation between quadrupole magnitude and the other observed phase transitions, with the nematic and smectic A phases being

Serous Macular Detachment Associated with Dome-Shaped Macula and Tilted Disc

Directory of Open Access Journals (Sweden)

Diamar Pardo-López

2011-03-01

Full Text Available Introduction: An entirely new type of staphyloma has been recently described as dome-shaped macula (DSM. It is characterized by an abnormal convex macular contour within the concavity of a posterior staphyloma. We found DSM associated with serous macular detachment (SMD and tilted disc in two consecutive cases. Case Reports: Case 1: A 37-year-old female presented to our department because of sudden onset blurred vision in her right eye (OD. The best-corrected visual acuity (BCVA was 0.5 in both eyes. Funduscopy evidenced bilateral tilted disc associated with posterior staphyloma. Optical coherence tomography (OCT demonstrated a DSM with SMD in her OD. After 15 months of follow-up, BCVA of her OD remained stable with chronic SMD. Case 2: A 32-year-old female presented to our department because of blurred vision in her OD. The BCVA was 0.4 in the OD and 1.0 in the left eye (OS. Bilateral tilted disc and posterior staphyloma were evidenced in the funduscopy. OCT demonstrated a bilateral DSM with SMD in her OD. After 45 months of follow-up, two further episodes of transient SMD were observed in her OD and seven in her OS. The final BCVA was 0.63 in the OD and 0.8 in the OS. Discussion: SMD associated with tilted disc constitutes a potential cause of subretinal fluid accumulation in myopic patients. OCT is essential for the detection of both SMD and DSM.

Number of radiological examinations in Finland in 2000

CERN Document Server

Hakanen, A

2002-01-01

STUK (Radiation and Nuclear Safety Authority) collected the number of radiological examinations in Finland in 2000. The work was based on a decree of the ministry of social affairs and health on the medical use of radiation. The work was done in cooperation with the Finnish work group of nomenclature of radiological examinations and procedures and professor Seppo Soimakallio. In 2000, ca. 4.1 million x-ray examinations were made in Finland. In 1984 and in 1995, the numbers were ca. 4.6 million and 4.2 million, respectively, indicating that the total number of x-ray examinations has remained nearly unaltered. The proportions of conventional x-ray examinations, computed tomography examinations, angiographic and interventional procedures were ca. 93.5 %, 5.0 %, 0.9 % and 0.6 %, respectively. The reported number of ultrasound examinations was ca. 0.5 million. The reported number of MRI examinations was ca. 0.1 million.

TILT ANGLE AND FOOTPOINT SEPARATION OF SMALL AND LARGE BIPOLAR SUNSPOT REGIONS OBSERVED WITH HMI

International Nuclear Information System (INIS)

McClintock, B. H.; Norton, A. A.

2016-01-01

We investigate bipolar sunspot regions and how tilt angle and footpoint separation vary during emergence and decay. The Helioseismic and Magnetic Imager on board the Solar Dynamic Observatory collects data at a higher cadence than historical records and allows for a detailed analysis of regions over their lifetimes. We sample the umbral tilt angle, footpoint separation, and umbral area of 235 bipolar sunspot regions in Helioseismic and Magnetic Imager—Debrecen Data with an hourly cadence. We use the time when the umbral area peaks as time zero to distinguish between the emergence and decay periods of each region and we limit our analysis of tilt and separation behavior over time to within ±96 hr of time zero. Tilt angle evolution is distinctly different for regions with small (≈30 MSH), midsize (≈50 MSH), and large (≈110 MSH) maximum umbral areas, with 45 and 90 MSH being useful divisions for separating the groups. At the peak umbral area, we determine median tilt angles for small (7.°6), midsize (5.°9), and large (9.°3) regions. Within ±48 hr of the time of peak umbral area, large regions steadily increase in tilt angle, midsize regions are nearly constant, and small regions show evidence of negative tilt during emergence. A period of growth in footpoint separation occurs over a 72-hr period for all of the regions from roughly 40 to 70 Mm. The smallest bipoles (<9 MSH) are outliers in that they do not obey Joy's law and have a much smaller footpoint separation. We confirm the Muñoz-Jaramillo et al. results that the sunspots appear to be two distinct populations

Flow tilt angles near forest edges - Part 1: Sonic anemometry

DEFF Research Database (Denmark)

Dellwik, Ebba; Mann, Jakob; Larsen, Klaus Steenberg

2010-01-01

distortion and vertical alignment, it was only possible to a limited extent to relate sonic anemometer flow tilt angles to upwind forest edges, but the results by the lidar indicated that an internal boundary layer affect flow tilt angles at 21m above the forest. This is in accordance with earlier studies......-flow angles were assumed for neutral flow, the data was interpreted in relation to upstream and downstream forest edges. Uncertainties caused by flow distortion, vertical misalignment and limited sampling time (statistical uncertainty) were evaluated and found to be highly significant. Since the attack angle...... balance, unless all terms in the carbon dioxide conservation equation can be precisely estimated....

Tilt table standing for reducing spasticity after spinal cord injury.

Science.gov (United States)

Bohannon, R W

1993-10-01

A patient with a T12 spinal cord injury and intractable extensor spasms of the lower extremities participated in tilt table standing trial on 5 nonconsecutive days to determine if the intervention would affect his spasticity and spasms. Each day's standing trial was followed by an immediate reduction in lower extremity spasticity (measured using the modified Ashworth scale and pendulum testing). Standing was also accompanied by a reduction in spasms that lasted until the following morning. The reduction of spasms was particularly advantageous to the performance of car transfers. Tilt table standing merits further examination as a physical treatment of spasms that accompany central nervous system lesions.

Formation of tilted smectic-C liquid crystal phase in polar Gay-Berne molecules

International Nuclear Information System (INIS)

Saha, J.; Bose, T.R.; Ghosh, D.; Saha, M.

2005-01-01

We perform molecular dynamics simulation for a system of Gay-Berne molecules having two terminal dipole moments to generate tilted smectic-C liquid crystal phase. We investigate the effect of dipolar orientation with respect to the long molecular axis on phase behaviour. The study indicates that larger dipolar angle can give rise to greater tilt in molecular organization within a layer

The effects of superimposed tilt and lower body negative pressure on anterior and posterior cerebral circulations

OpenAIRE

Tymko, Michael M.; Rickards, Caroline A.; Skow, Rachel J.; Ingram?Cotton, Nathan C.; Howatt, Michael K.; Day, Trevor A.

2016-01-01

Abstract Steady?state tilt has no effect on cerebrovascular reactivity to increases in the partial pressure of end?tidal carbon dioxide (PETCO 2). However, the anterior and posterior cerebral circulations may respond differently to a variety of stimuli that alter central blood volume, including lower body negative pressure (LBNP). Little is known about the superimposed effects of head?up tilt (HUT; decreased central blood volume and intracranial pressure) and head?down tilt (HDT; increased ce...

Contribution of diffuser surfaces to efficiency of tilted T shape parallel highway noise barriers

Directory of Open Access Journals (Sweden)

N. Javid Rouzi

2009-04-01

Full Text Available Background and aimsThe paper presents the results of an investigation on the acoustic  performance of tilted profile parallel barriers with quadratic residue diffuser tops and faces.MethodsA2D boundary element method (BEM is used to predict the barrier insertion loss. The results of rigid and with absorptive coverage are also calculated for comparisons. Using QRD on the top surface and faces of all tilted profile parallel barrier models introduced here is found to  improve the efficiency of barriers compared with rigid equivalent parallel barrier at the examined  receiver positions.Results Applying a QRD with frequency design of 400 Hz on 5 degrees tilted parallel barrier  improves the overall performance of its equivalent rigid barrier by 1.8 dB(A. Increase the treated surfaces with reactive elements shifts the effective performance toward lower frequencies. It is  found that by tilting the barriers from 0 to 10 degrees in parallel set up, the degradation effects in  parallel barriers is reduced but the absorption effect of fibrous materials and also diffusivity of thequadratic residue diffuser is reduced significantly. In this case all the designed barriers have better  performance with 10 degrees tilting in parallel set up.ConclusionThe most economic traffic noise parallel barrier, which produces significantly  high performance, is achieved by covering the top surface of the barrier closed to the receiver by  just a QRD with frequency design of 400 Hz and tilting angle of 10 degrees. The average Aweighted  insertion loss in this barrier is predicted to be 16.3 dB (A.

Pressure-induced phase transition and octahedral tilt system change of Ba2BiSbO6

International Nuclear Information System (INIS)

Lufaso, Michael W.; Macquart, Rene B.; Lee, Yongjae; Vogt, Thomas; Loye, Hans-Conrad zur

2006-01-01

High-resolution X-ray synchrotron powder diffraction studies under high-pressure conditions are reported for the ordered double perovskite Ba 2 BiSbO 6 . Near 4GPa, the oxide undergoes a pressure-induced phase transition. The symmetry of the material changes during the phase transition from space group R3-bar to space group I2/m, which is consistent with a change in the octahedral tilting distortion from an a - a - a - type to a 0 b - b - type using the Glazer notation. A fit of the volume-pressure data using the Birch-Murnagaham equation of state yielded a bulk modulus of 144(8)GPa for the rhombohedral phase

Motion sickness and tilts of the inertial force environment : Active suspension systems vs. active passengers

NARCIS (Netherlands)

Golding, J. F.; van der Bles, W.; Bos, J. E.; Haynes, T.; Gresty, M. A.

2003-01-01

Background: Maneuvering in vehicles exposes occupants to low frequency forces (<1 Hz) which can provoke motion sickness. Hypothesis: Aligning with the tilting inertial resultant (gravity + imposed horizontal acceleration: gravito-inertial force (GIF)) may reduce motion sickness when tilting is

Tilted cranking classification of multibandspectra

Energy Technology Data Exchange (ETDEWEB)

Frauendorf, S [IHK F2-Rossendorf, Dresden (Germany); [Lawrence Berkeley Lab., CA (United States); May, F R [Niels Bohr Inst., Copenhagen (Denmark); [Lund Univ. (Sweden). Dept. of Mathematical Physics

1992-08-01

The tilted cranking theory of multi-band spectra of deformed nuclei is discussed. The existence of TDHF (time-dependent Hartree Fock) solutions rotating uniformly about a non-principal axis of the deformed axial potential is demonstrated. The solutions represent {Delta}I=1 bands. Self-consistency and symmetry are discussed. The transfer of experimental spectra to the rotating field of reference is introduced. Excitation spectra at high spin are calculated, and found to agree well with recent data on {sup 163}Er and {sup 174}Hf. 7 refs., 5 figs.

A transversely isotropic medium with a tilted symmetry axis normal to the reflector

KAUST Repository

Alkhalifah, Tariq Ali

2010-05-01

The computational tools for imaging in transversely isotropic media with tilted axes of symmetry (TTI) are complex and in most cases do not have an explicit closed-form representation. Developing such tools for a TTI medium with tilt constrained to be normal to the reflector dip (DTI) reduces their complexity and allows for closed-form representations. The homogeneous-case zero-offset migration in such a medium can be performed using an isotropic operator scaled by the velocity of the medium in the tilt direction. For the nonzero-offset case, the reflection angle is always equal to the incidence angle, and thus, the velocities for the source and receiver waves at the reflection point are equal and explicitly dependent on the reflection angle. This fact allows for the development of explicit representations for angle decomposition as well as moveout formulas for analysis of extended images obtained by wave-equation migration. Although setting the tilt normal to the reflector dip may not be valid everywhere (i.e., on salt flanks), it can be used in the process of velocity model building, in which such constrains are useful and typically are used. © 2010 Society of Exploration Geophysicists.

A transversely isotropic medium with a tilted symmetry axis normal to the reflector

KAUST Repository

Alkhalifah, Tariq Ali; Sava, Paul C.

2010-01-01

The computational tools for imaging in transversely isotropic media with tilted axes of symmetry (TTI) are complex and in most cases do not have an explicit closed-form representation. Developing such tools for a TTI medium with tilt constrained to be normal to the reflector dip (DTI) reduces their complexity and allows for closed-form representations. The homogeneous-case zero-offset migration in such a medium can be performed using an isotropic operator scaled by the velocity of the medium in the tilt direction. For the nonzero-offset case, the reflection angle is always equal to the incidence angle, and thus, the velocities for the source and receiver waves at the reflection point are equal and explicitly dependent on the reflection angle. This fact allows for the development of explicit representations for angle decomposition as well as moveout formulas for analysis of extended images obtained by wave-equation migration. Although setting the tilt normal to the reflector dip may not be valid everywhere (i.e., on salt flanks), it can be used in the process of velocity model building, in which such constrains are useful and typically are used. © 2010 Society of Exploration Geophysicists.

Motion sickness and tilts of the inertial force environment: active suspension systems vs. active passengers

NARCIS (Netherlands)

Golding, J.F.; Bles, W.; Bos, J.E.; Haynes, T.; Gresty, M.A.

2003-01-01

Maneuvering in vehicles exposes occupants to low frequency forces (<1 Hz) which can provoke motion sickness. Hypothesis: Aligning with the tilting inertial resultant (gravity + imposed horizontal acceleration: gravito-inertial force (GIF)) may reduce motion sickness when tilting is either 'active'

System for the Automatic Estimation of the Tilt Angle of a Flat Solar Collector

Directory of Open Access Journals (Sweden)

Jorge Fonseca-Campos

2017-08-01

Full Text Available In this work, a compact system for the automatic estimation of the tilt angle at any location of the world is presented. The system components are one computer, one GPS receiver and one Python program. The tilt angle is calculated through the maximization of the flux of direct radiation incident upon a flat solar collector. An estimation of the adjustments of this angle at different time periods are obtained. This angle is calculated in steps of six minutes during a whole year. Daily, monthly, biannually and yearly averages of this value are obtained. A comparison of the energetic gain when the tilt angle changes at the different time periods is made as well. Because, the algorithm doesn’t receive as an input the solar radiation incident upon a surface at the location of the calculation, a comparison was made between the results obtained and the results reported for the monthly tilt angle of 22 different places. The root mean square error obtained with this comparison was between 1.5 and 9.5 degrees. The monthly tilt angle estimated deviated in average for less than 6.3° with respect to the values reported for the different locations. Finally, the application of a correction factor in the monthly estimated angles is proposed, which might increase the collected energy.

Mathematical Model and Analysis of the Water-Lubricated Hydrostatic Journal Bearings considering the Translational and Tilting Motions

Directory of Open Access Journals (Sweden)

Hui-Hui Feng

2014-01-01

Full Text Available The water-lubricated bearings have been paid attention for their advantages to reduce the power loss and temperature rise and increase load capacity at high speed. To fully study the complete dynamic coefficients of two water-lubricated, hydrostatic journal bearings used to support a rigid rotor, a four-degree-of-freedom model considering the translational and tilting motion is presented. The effects of tilting ratio, rotary speed, and eccentricity ratio on the static and dynamic performances of the bearings are investigated. The bulk turbulent Reynolds equation is adopted. The finite difference method and a linear perturbation method are used to calculate the zeroth- and first-order pressure fields to obtain the static and dynamic coefficients. The results suggest that when the tilting ratio is smaller than 0.4 or the eccentricity ratio is smaller than 0.1, the static and dynamic characteristics are relatively insensitive to the tilting and eccentricity ratios; however, for larger tilting or eccentricity ratios, the tilting and eccentric effects should be fully considered. Meanwhile, the rotary speed significantly affects the performance of the hydrostatic, water-lubricated bearings.

Transient theory of double slope floating cum tilted - wick type solar still

International Nuclear Information System (INIS)

Balan, R.; Chandrasekaran, J.; Janarthanan, B.; Kumar, S.

2011-01-01

A double slope floating cum tilted-wick solar still has been fabricated and transient theory of floating cum tilted-wick type solar still has been proposed. Analytical expressions have been derived for the different temperatures components of the proposed system. For elocution of the analytical results, numerical calculations have been carried out using the meteorological parameters for a typical summer day in Coimbatore. Analytical expression results are found to be in the close agreement with the experimental results. (authors)

Tilt signals at Mount Melbourne, Antarctica: evidence of a shallow volcanic source

Directory of Open Access Journals (Sweden)

Salvatore Gambino

2016-06-01

Full Text Available Mount Melbourne (74°21′ S, 164°43′ E is a quiescent volcano located in northern Victoria Land, Antarctica. Tilt signals have been recorded on Mount Melbourne since early 1989 by a permanent shallow borehole tiltmeter network comprising five stations. An overall picture of tilt, air and permafrost temperatures over 15 years of continuous recording data is reported. We focused our observations on long-term tilt trends that at the end of 1997 showed coherent changes at the three highest altitude stations, suggesting the presence of a ground deformation source whose effects are restricted to the summit area of Mount Melbourne. We inverted these data using a finite spherical body source, thereby obtaining a shallow deflation volume source located under the summit area. The ground deformation observed corroborates the hypothesis that the volcanic edifice of Mount Melbourne is active and should be monitored multidisciplinarily.

Effect of tilted anisotropy on spin states of strongly anisotropic 2D film

International Nuclear Information System (INIS)

Fridman, Yu. A.; Klevets, F. N.; Gorelikov, G. A.

2012-01-01

The spin states of a 2D film with a strong easy-plane anisotropy and single-ion tilted anisotropy, the axis of which forms a certain angle with the normal to the film plane are investigated. In this system, an angular ferromagnetic phase, a spatially inhomogeneous state, and a quadrupole phase can be formed; the realization of these states noticeably depends on the degree of tilted anisotropy.

Investigation of the diffractive reaction p + N → [Σ+K0] + N at the proton energy of Ep = 70 GeV and observation of the decay process X(2000) → Σ+K0

International Nuclear Information System (INIS)

Vavilov, D.V.; Viktorov, V.A.; Golovkin, S.V.; Kozhevnikov, A.P.; Kubarovsky, V.P.; Kurshetsov, V.F.; Landsberg, L.G.; Molchanov, V.V.; Mukhin, V.A.; Petrenko, S.V.; Kolganov, V.Z.; Lomkatsi, G.S.; Nilov, A.F.; Smolyankin, V.T.

2000-01-01

The diffractive reaction p + N → [Σ + K 0 ] + N induced by 70-GeV protons is investigated at the SPHINX facility. The measured mass spectrum of the Σ + K 0 system originating from this reaction shows a resonance structure with a mass of M = 1995 ± 18 MeV and a width of Γ = 90 ± 32 MeV. The cross section for the formation of this structure is found to be σ = 182 ± 38 nb per target nucleon. These data comply well with the results that we obtained previously in studying the reaction p + N → [Σ 0 K + ] + N, where we observed the formation of the X(2000) → Σ 0 K + state, a candidate for an exotic baryon with hidden strangeness. The measured ratio R of the two branching fractions, R = Br[X(2000) → Σ + K 0 ]/Br[X(2000) → Σ 0 K + ] =1.91 ± 0.38, is consistent with the value of R = 2 expected for an isospin-1/2 baryon

MODELLING AND CONTROL OF H-SHAPED RACING QUADCOPTER WITH TILTING PROPELLERS

Directory of Open Access Journals (Sweden)

Ahmed Alkamachi

2017-08-01

Full Text Available Traditional quadcopter suffers terribly from its underactuation which implies the coupling between the rotational and the translational motion. In this paper, we present a quadcopter with dynamic rotor tilting capability in which the four propellers are allowed to tilt together around their arm axis. The proposed model provides leveled forward/backward horizontal motion and therefore, ensures a correct view of the onboard camera, and increases the vehicle speed by reducing the air drag. The rotor tilt mechanism also provides an instant high speed in the forward or reverse direction and offers a quick and solid air brake to restrain that fast moving speed.  The nonlinear dynamical model for the quadcopter under consideration is derived using Newton-Euler formalization. A control strategy is then proposed aimed to control the altitude, attitude, and the forward speed of the obtained model. Finally, a numerical simulation is used to integrate the system model with the controller and to test the system performance. Simulation results are reported to demonstrate the advantages of the proposed novel configuration.

Octahedral tilt independent magnetism in confined GdTiO3 films

Science.gov (United States)

Need, R. F.; Isaac, B. J.; Kirby, B. J.; Borchers, J. A.; Stemmer, S.; Wilson, Stephen D.

2018-03-01

Low temperature polarized neutron reflectometry measurements are presented, exploring the evolution of ferrimagnetism in thin GdTiO3 films embedded within a SrTiO3 matrix. In GdTiO3 films thinner than ˜4 nm, the TiO6 octahedral tilts endemic to GdTiO3 coherently relax toward the undistorted, cubic phase of SrTiO3. Our measurements indicate that the ferrimagnetic state within the GdTiO3 layers survives as these TiO6 octahedral tilts are suppressed. Furthermore, our data suggest that layers of suppressed magnetization (i.e., magnetic dead layers) develop within the GdTiO3 layer at each GdTiO3/SrTiO3 interface and explain the apparent magnetization suppression observed in thin GdTiO3 films when using volume-averaged techniques. Our data show that the low temperature magnetic moment inherent to the core GdTiO3 layers is only weakly impacted as the octahedral tilt angles are suppressed by more than 50% and the t2 g bandwidth is dramatically renormalized.

BDML Metadata: 388 [SSBD[Archive

Lifescience Database Archive (English)

Full Text Available aw reconstruction of early Drosophila wild-type development D. melanogaster nuclear positions drosophila_raw...ken.jp/data/bdml/DM_PJK/drosophila_raw.bdml0.15.xml http://ssbd.qbic.riken.jp/search/e5b0d300-d843-46fb-abb1-3e59f8f54751/ ... ...A 0.150 e5b0d300-d843-46fb-abb1-3e59f8f54751 0.37 x 0.37 x 0.37 (micrometer), 3 (minute) http://ssbd.qbic.ri

A new method to detect and correct sample tilt in scanning transmission electron microscopy bright-field imaging

Energy Technology Data Exchange (ETDEWEB)

Brown, H.G. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Ishikawa, R.; Sánchez-Santolino, G. [Institute of Engineering Innovation, School of Engineering, University of Tokyo, Tokyo 113-8656 (Japan); Lugg, N.R., E-mail: shibata@sigma.t.u-tokyo.ac.jp [Institute of Engineering Innovation, School of Engineering, University of Tokyo, Tokyo 113-8656 (Japan); Ikuhara, Y. [Institute of Engineering Innovation, School of Engineering, University of Tokyo, Tokyo 113-8656 (Japan); Allen, L.J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Shibata, N. [Institute of Engineering Innovation, School of Engineering, University of Tokyo, Tokyo 113-8656 (Japan)

2017-02-15

Important properties of functional materials, such as ferroelectric shifts and octahedral distortions, are associated with displacements of the positions of lighter atoms in the unit cell. Annular bright-field scanning transmission electron microscopy is a good experimental method for investigating such phenomena due to its ability to image light and heavy atoms simultaneously. To map atomic positions at the required accuracy precise angular alignment of the sample with the microscope optical axis is necessary, since misalignment (tilt) of the specimen contributes to errors in position measurements of lighter elements in annular bright-field imaging. In this paper it is shown that it is possible to detect tilt with the aid of images recorded using a central bright-field detector placed within the inner radius of the annular bright-field detector. For a probe focus near the middle of the specimen the central bright-field image becomes especially sensitive to tilt and we demonstrate experimentally that misalignment can be detected with a precision of less than a milliradian, as we also confirm in simulation. Coma in the probe, an aberration that can be misidentified as tilt of the specimen, is also investigated and it is shown how the effects of coma and tilt can be differentiated. The effects of tilt may be offset to a large extent by shifting the diffraction plane detector an amount equivalent to the specimen tilt and we provide an experimental proof of principle of this using a segmented detector system. - Highlights: • Octahedral distortions are associated with displacements of lighter atoms. • Annular bright-field imaging is sensitive to light and heavy atoms simultaneously. • Mistilt of the specimen leads to errors in position measurements of lighter elements. • It is possible to detect tilt using images taken by a central bright-field detector. • Tilt may be offset by shifting the diffraction plane detector by an equivalent amount.

Properties of HTS YBCO thin films deposited on tilted NdGaO{sub 3} substrates

Energy Technology Data Exchange (ETDEWEB)

Nurgaliev, T. [Laboratory of Superconductivity and Cryoelectronics, Institute of Electronics BAS, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria)]. E-mail: timur@ie.bas.bg; Donchev, T. [Laboratory of Superconductivity and Cryoelectronics, Institute of Electronics BAS, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Mateev, E. [Laboratory of Superconductivity and Cryoelectronics, Institute of Electronics BAS, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Miteva, S. [Laboratory of Superconductivity and Cryoelectronics, Institute of Electronics BAS, 72 Tsarigradsko Chausse, 1784 Sofia (Bulgaria); Mozhaev, P.B. [Institute of Physics and Technology RAS, Nakhimovsky Ave. 36, 117218 Moscow (Russian Federation); Mozhaeva, J.E. [Institute of Physics and Technology RAS, Nakhimovsky Ave. 36, 117218 Moscow (Russian Federation)

2005-03-15

Thin YBa{sub 2}Cu{sub 3}O{sub 7} films were fabricated by 2-opposed DC magnetron sputtering onto NdGaO{sub 3} substrates, tilted from standard (1 1 0) orientation by 0-26 deg , and their surface morphology and electrical characteristics were investigated. Normal state resistivity (at 295 K) and microwave surface resistance (at 77 K and {approx}8 GHz) of the films demonstrated anisotropy, introduced by the tilted substrate, and some improvement of the superconducting parameters of the films was observed at small tilt angles ({theta} {approx} 1.5-3 deg ). The increase of the microwave surface resistance at high tilt angles for the current tracks, perpendicular to the steps of the substrate, was described in the framework of a simple model, which takes into account the complex conductivity of the film and the weak links between the film terraces.

The dynamic performance of narrow actively tilting vehicles

NARCIS (Netherlands)

Pauwelussen, J.P.

2000-01-01

The major advantage of a motorcycle with respect to a passenger car is the possibility of the driver to tilt during cornering and thereby maintaining stability whereas a passenger car will suffer from the risk of capsizing at high speed. This observation has motivated recently various manufacturers

LULI 2000 activity report

International Nuclear Information System (INIS)

2000-01-01

This document gathers the main results obtained by scientists from the LULI (laboratory for the use of intense lasers) unit in 2000. It is made up of 58 short articles and is organized into 6 topics: 1) laser-matter interaction, 2) hydrodynamics, shocks, equations of state, 3) atom physics, X-ray lasers, 4) material treatment, 5) progress in optics for power lasers, and 6) instrumentation and other advances

Determination of the Optimal Tilt Angle for Solar Photovoltaic Panel in Ilorin, Nigeria

Directory of Open Access Journals (Sweden)

K.R. Ajao

2013-06-01

Full Text Available The optimal tilt angle of solar photovoltaic panel in Ilorin, Nigeria was determined. The solar panel was first mounted at 0o to the horizontal and after ten minutes, the voltage and current generated with the corresponding atmospheric temperature were recorded. The same procedure was repeated for 2o to 30o at a succession of 2o at ten minutes time interval over the entire measurement period. The result obtained shows that the average optimal tilt angle at which a solar panel will be mounted for maximum power performance at fixed position in Ilorin is 22o. This optimum angle of tilt of the solar panel and the orientation are dependent on the month of the year and the location of the site of study.

Increased Aldosterone Release During Head-Up Tilt in Early Primary Hypertension.

Science.gov (United States)

Reinold, Annemarie; Schneider, Andreas; Kalizki, Tatjana; Raff, Ulrike; Schneider, Markus P; Schmieder, Roland E; Schmidt, Bernhard M W

2017-05-01

Hyperaldosteronism is well known cause of secondary hypertension. However, the importance of aldosterone for the much larger group of patients with primary hypertension is less clear. We hypothesized that in young subjects with primary hypertension, the rise of plasma aldosterone levels in response to head-up tilt testing as a stress stimulus is exaggerated. Hemodynamics (blood pressure (BP), heart rate (HR), cardiac index (CI), and total peripheral vascular resistance index (TPRI), all by TaskForce monitor) and hormones (plasma renin activity (PRA), angiotensin II (Ang II), aldosterone) were measured before and during 30 minutes of head-up tilt in 45 young hypertensive and 45 normotensive subjects. BP, HR, CI, and TPRI all increased in response to head-up tilt, with no difference between groups. There was no difference in baseline PRA, Ang II, and aldosterone between groups. During head-up tilt, PRA, and Ang II levels increased similarly. However, aldosterone levels increased to a greater extent in the hypertensive vs. normotensive subjects (P = 0.0021). Our data suggest that an increased release of aldosterone in response to orthostatic stress is a feature of early primary hypertension. The similar increase in PRA and Ang II suggests a potential role for secretagogues of aldosterone other than Ang II in this response. In addition to its established role in secondary hypertension, dysregulation of aldosterone release might contribute to the development of primary arterial hypertension. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Single macroscopic pillars as model system for bioinspired adhesives: influence of tip dimension, aspect ratio, and tilt angle.

Science.gov (United States)

Micciché, Maurizio; Arzt, Eduard; Kroner, Elmar

2014-05-28

The goal of our study is to better understand the design parameters of bioinspired dry adhesives inspired by geckos. For this, we fabricated single macroscopic pillars of 400 μm diameter with different aspect ratios and different tip shapes (i.e., flat tips, spherical tips with different radii, and mushroom tips with different diameters). Tilt-angle-dependent adhesion measurements showed that although the tip shape of the pillars strongly influences the pull-off force, the pull-off strength is similar for flat and mushroom-shaped tips. We found no tilt-angle dependency of adhesion for spherical tip structures and, except for high tilt angle and low preload experiments, no tilt-angle effect for mushroom-tip pillars. For flat-tip pillars, we found a strong influence of tilt angle on adhesion, which decreased linearly with increasing aspect ratio. The experiments show that for the tested aspect ratios between 1 and 5, a linear decrease of tilt-angle dependency is found. The results of our studies will help to design bioinspired adhesives for application on smooth and rough surfaces.

Physical insight into the thermodynamic uncertainty relation using Brownian motion in tilted periodic potentials

Science.gov (United States)

Hyeon, Changbong; Hwang, Wonseok

2017-07-01

Using Brownian motion in periodic potentials V (x ) tilted by a force f , we provide physical insight into the thermodynamic uncertainty relation, a recently conjectured principle for statistical errors and irreversible heat dissipation in nonequilibrium steady states. According to the relation, nonequilibrium output generated from dissipative processes necessarily incurs an energetic cost or heat dissipation q , and in order to limit the output fluctuation within a relative uncertainty ɛ , at least 2 kBT /ɛ2 of heat must be dissipated. Our model shows that this bound is attained not only at near-equilibrium [f ≪V'(x ) ] but also at far-from-equilibrium [f ≫V'(x ) ] , more generally when the dissipated heat is normally distributed. Furthermore, the energetic cost is maximized near the critical force when the barrier separating the potential wells is about to vanish and the fluctuation of Brownian particles is maximized. These findings indicate that the deviation of heat distribution from Gaussianity gives rise to the inequality of the uncertainty relation, further clarifying the meaning of the uncertainty relation. Our derivation of the uncertainty relation also recognizes a bound of nonequilibrium fluctuations that the variance of dissipated heat (σq2) increases with its mean (μq), and it cannot be smaller than 2 kBT μq .

Spread of Cooking Bananas (Musa spp., genome ABB in a Traditional Plantain-Growing Area in Southeast Nigeria

Directory of Open Access Journals (Sweden)

Ezedinma, C.

2002-01-01

Full Text Available The study examined the level and rate of spread of cooking bananas (Musa spp., ABB genome to determine their success among the farmers. They were introduced in Southeastern Nigeria in the mid-1980s by the International Institute of Tropical Agriculture (IITA as an interim measure to reduce the incidence of black sigatoka disease on plantains. Data were collected, using a structured questionnaire, from 285 randomly selected farmers in 76 villages. Results of the study indicate that about 60% of the respondents have given out suckers to other fellow-farmers. On average, every "diffuser" distributed 8 cooking banana suckers to 5 new fellow-farmers. Primary and secondary diffusions accounted for 59% and 61% respectively; while inter-village diffusion accounted for about 50% of the movement of the suckers. The study also found that the demand for the crop has been increasing since its introduction in the region. These results indicate a high level of diffusion of the crop considering its newness in the region and that it is well accepted. They also suggest that the crop has the potential of supplementing plantain in food and income generation for the farmers in the region.

Description of multi-quasiparticle bands by the tilted axis cranking model

International Nuclear Information System (INIS)

Frauendorf, S.

2000-01-01

The selfconsistent cranking approach is extended to the case of rotation about an axis which is tilted with respect to the principal axes of the deformed potential (Tilted Axis Cranking). Expressions for the energies and the intra bands electro-magnetic transition probabilities are given. The mean field solutions are interpreted in terms of quantal rotational states. The construction of the quasiparticle configurations and the elimination of spurious states is discussed. The application of the theory to high spin data is demonstrated by analyzing the multi-quasiparticle bands in the nuclides with N=102,103 and Z=71,72,73

Synthesis and characterization of Sr2Ir1−xMxO4 (M=Ti, Fe, Co) solid solutions

International Nuclear Information System (INIS)

Gatimu, Alvin J.; Berthelot, Romain; Muir, Sean; Sleight, Arthur W.; Subramanian, M.A.

2012-01-01

The effects of Ti, Fe and Co substitutions for Ir on the structure and on the physical properties of Sr 2 IrO 4 are investigated. A complete solid solution Sr 2 Ir 1−x Ti x O 4 is obtained while both Fe and Co doping are relatively limited. In each case however, the c-axis cell parameter and the initial IrO 6 octahedra tilting decreases with substitution. Doping with Ti, Fe and Co results in a decrease of the magnetic susceptibility and in an increase in the paramagnetic effective moment for Co and Fe doped samples and a suppression of the weak ferromagnetic ordering observed for Sr 2 IrO 4 . - Graphical abstract: Solid solutions of Sr 2 Ir 1−x M x O 4 (M=Ti, Fe, Co) have been synthesized and characterized by powder X-ray diffraction, magnetism and electrical measurements. Changes in the a parameter and decreases in both the c-axis cell parameters and the initial IrO 6 octahedra tilting are found to be correlated. Highlights: ► Solid Solutions of Sr 2 Ir 1−x M x O 4 (M=Ti, Fe, Co) are synthesized. ► The Sr 2 Ir 1−x Ti x O 4 solid solution is complete while those of Fe and Co are relatively limited. ► The change in a cell parameter with substitution is much less than that of the c parameter. ► Decreased tilting and the smaller size of the M cation contrastingly affect the a parameter. ► Doping results in a suppression of the weak ferromagnetic ordering in Sr 2 IrO 4 .

Patients with severe acquired brain injury show increased arousal in tilt-table training

DEFF Research Database (Denmark)

Riberholt, Christian G; Thorlund, Jonas Bloch; Mehlsen, Jesper

2013-01-01

Patients with severe acquired brain injury (ABI) are often mobilised using a tilt-table. Complications such as orthostatic intolerance have been reported. The primary objective of this study was to investigate if using a tilt-table was feasible for mobilising patients with severe ABI admitted...... for sub-acute rehabilitation. We also investigated change in arousal, treatment duration before termination due to orthostatic reactions and change in muscle tone....

Tilted c-Axis Thin-Film Bulk Wave Resonant Pressure Sensors With Improved Sensitivity

OpenAIRE

Anderås, Emil; Katardjiev, Ilia; Yantchev, Ventsislav

2012-01-01

Aluminum nitride thin film bulk wave resonant pressure sensors employing c- and tilted c-axis texture, have been fabricated and tested for their pressure sensitivities. The c-axis tilted FBAR pressure sensors demonstrate substantially higher pressure sensitivity compared to its c-axis oriented counterpart. More specifically the thickness plate quasi-shear resonance has demonstrated the highest pressure sensitivity while further being able to preserve its performance in liquid environment.

Slow changing postural cues cancel visual field dependence on self-tilt detection.

Science.gov (United States)

Scotto Di Cesare, C; Macaluso, T; Mestre, D R; Bringoux, L

2015-01-01

Interindividual differences influence the multisensory integration process involved in spatial perception. Here, we assessed the effect of visual field dependence on self-tilt detection relative to upright, as a function of static vs. slow changing visual or postural cues. To that aim, we manipulated slow rotations (i.e., 0.05° s(-1)) of the body and/or the visual scene in pitch. Participants had to indicate whether they felt being tilted forward at successive angles. Results show that thresholds for self-tilt detection substantially differed between visual field dependent/independent subjects, when only the visual scene was rotated. This difference was no longer present when the body was actually rotated, whatever the visual scene condition (i.e., absent, static or rotated relative to the observer). These results suggest that the cancellation of visual field dependence by dynamic postural cues may rely on a multisensory reweighting process, where slow changing vestibular/somatosensory inputs may prevail over visual inputs. Copyright © 2014 Elsevier B.V. All rights reserved.

Downward continuation and tilt derivative of magnetic data for ...

Indian Academy of Sciences (India)

S K Pal

2017-06-12

Jun 12, 2017 ... Downward continuation; tilt derivative; magnetic data; coal fire mapping; Jharia coal field;. India. 1. .... of seams are thin and not suitable for mining but have the ...... Theory and Application; McGraw Hill Education (India).

determination of determination of optimal tilt angle for maximum

African Journals Online (AJOL)

eobe

Keywords: Energy output, photovoltaic module, best tilt angle, solar radiation, sunshine hours, ambient temperature. 1. .... at any given time is vital in the design of a PV system. The solar ..... [8] E. Taymur, Photovoltaic System Sizing [thesis].

A study of tilt change recorded from July to October 2006 at the Phlegraean Fields (Naples, Italy

Directory of Open Access Journals (Sweden)

C. Del Gaudio

2007-06-01

Full Text Available The tiltmetric dataset of Phlegraean Fields area showed a discrete correlation with the volcanic dynamics, suggesting that tiltmetric monitoring is important for the surveillance of active volcanic areas. Tilt data recorded in 2006 at 2 stations belonging to the monitoring network of the Osservatorio Vesuviano (INGV, National Institute for Geophysics and Volcanology, Italy in the Phlegraean Fields are discussed in this paper. The acquired signals have shown a strong tiltmetric inversion that took place from the end of July 2006. After correcting tilt variations to eliminate the influence of temperature (influencing 90% of the signal at OLB station, hereafter OLB a significant value of the tilt still remains. This change is related to a local inflation episode lasting 3 months, during an unrest phase that started 2 years before. It is interesting to note that tilt amplitude is much greater at OLB than the slope of the displacement field predicted by the theoretical inflation models, but data show that this field is not homogeneous and in some areas very tilted. Moreover, in the last days before the end of tilt inversion, a low energy seismic swarm happened at about 1 km of distance from the tiltmetric station by hundreds of VT (Volcano-Tectonics and LP (Long-Period events.

The clinical relevance of the duration of loss of consciousness provoked by tilt testing.

Science.gov (United States)

Zyśko, Dorota; Gajek, Jacek; Kozluk, Edward; Agrawal, Anil Kumar; Smereka, Jacek; Checiński, Igor

2010-04-01

The authors assessed the relationships between the duration of loss of consciousness (dLOC) during tilt testing-induced syncope (TTS) and demographics, medical history as well as tilt testing results. Previous research focused on the relevance of the type of neurocardiogenic reaction during TTS. The importance of dLOC has not been assessed so far. The study was carried out in 274 patients with suspected neurally mediated syncope and total loss of consciousness during tilt testing. The syncope burden, demographics, and data regarding spontaneous syncope orTTS were compared between group I with dLOC > or =47 seconds and group 2 with dLOC <47 seconds. Medical history revealed that patients in group I had more syncopal spells, more frequent syncope-related traumatic injuries, urine incontinence, jerking movements and typical vasovagal history than in group 2. Moreover, group I patients had more frequently a cardioinhibitory type of reaction and a shorter active phase duration. In addition, they manifested more frequent accompanying cerebral hypoperfusion signs and reproduction of symptoms during TTS than patients in group 2. The loss of consciousness during tilt testing-induced syncope differs in terms of duration among patients with neurally mediated syncope. The dLOC during TTS is associated with medical history and tilt-testing data which confirm the vasovagal aetiology of spontaneous events. The longer dLOC suggests deeper cerebral haemodynamic disturbances during either spontaneous or provoked syncope.

Tilting-induced decrease in systolic blood pressure in bedridden hypertensive elderly inpatients: effects of azelnidipine.

Science.gov (United States)

Morimoto, Shigeto; Takahashi, Takashi; Okaishi, Kohya; Nakahashi, Takeshi; Nomura, Kohji; Kanda, Tsugiyasu; Okuro, Masashi; Murai, Hiroshi; Nishino, Tomoichi; Matsumoto, Masayuki

2006-12-01

The object of this study was to examine blood pressure (BP) variability due to postural change in elderly hypertensive patients. The subjects studied were 154 elderly inpatients in a hospital for the elderly (48 male and 106 female; median age: 82 years), consisting of age- and sex-matched bedridden (n=39) and non-bedridden (n=39) normotensive controls and bedridden (n=38) and non-bedridden (n=38) hypertensive patients. BP and pulse rate (PR) were measured in the supine position, then again after a 2-min, 45 deg head-up tilt with the legs horizontal. The decrease in systolic BP (SBP) on tilting in the bedridden hypertensive group (median: -10 mmHg; range: -32 to 9 mmHg) was significantly (pbedridden hypertensive group. Our findings indicate that tilt-induced decrease in SBP is a rather common phenomenon in bedridden elderly hypertensive patients, and that treatment with azelnidipine attenuates tilt-induced decrease in SBP, probably through an improvement of baroreceptor sensitivity.

Modeling of Tilting-Pad Journal Bearings with Transfer Functions

Directory of Open Access Journals (Sweden)

J. A. Vázquez

2001-01-01

Full Text Available Tilting-pad journal bearings are widely used to promote stability in modern rotating machinery. However, the dynamics associated with pad motion alters this stabilizing capacity depending on the operating speed of the machine and the bearing geometric parameters, particularly the bearing preload. In modeling the dynamics of the entire rotor-bearing system, the rotor is augmented with a model of the bearings. This model may explicitly include the pad degrees of freedom or may implicitly include them by using dynamic matrix reduction methods. The dynamic reduction models may be represented as a set of polynomials in the eigenvalues of the system used to determine stability. All tilting-pad bearings can then be represented by a fixed size matrix with polynomial elements interacting with the rotor. This paper presents a procedure to calculate the coefficients of polynomials for implicit bearing models. The order of the polynomials changes to reflect the number of pads in the bearings. This results in a very compact and computationally efficient method for fully including the dynamics of tilting-pad bearings or other multiple degrees of freedom components that interact with rotors. The fixed size of the dynamic reduction matrices permits the method to be easily incorporated into rotor dynamic stability codes. A recursive algorithm is developed and presented for calculating the coefficients of the polynomials. The method is applied to stability calculations for a model of a typical industrial compressor.

An iterative, fast-sweeping-based eikonal solver for 3D tilted anisotropic media

KAUST Repository

Waheed, Umair bin; Yarman, Can Evren; Flagg, Garret

2015-01-01

Computation of first-arrival traveltimes for quasi-P waves in the presence of anisotropy is important for high-end near-surface modeling, microseismic-source localization, and fractured-reservoir characterization - and it requires solving an anisotropic eikonal equation. Anisotropy deviating from elliptical anisotropy introduces higher order nonlinearity into the eikonal equation, which makes solving the eikonal equation a challenge. We addressed this challenge by iteratively solving a sequence of simpler tilted elliptically anisotropic eikonal equations. At each iteration, the source function was updated to capture the effects of the higher order nonlinear terms. We used Aitken's extrapolation to speed up convergence rate of the iterative algorithm. The result is an algorithm for computing first-arrival traveltimes in tilted anisotropic media. We evaluated the applicability and usefulness of our method on tilted transversely isotropic media and tilted orthorhombic media. Our numerical tests determined that the proposed method matches the first arrivals obtained by wavefield extrapolation, even for strongly anisotropic and highly complex subsurface structures. Thus, for the cases where two-point ray tracing fails, our method can be a potential substitute for computing traveltimes. The approach presented here can be easily extended to compute first-arrival traveltimes for anisotropic media with lower symmetries, such as monoclinic or even the triclinic media.

An iterative, fast-sweeping-based eikonal solver for 3D tilted anisotropic media

KAUST Repository

Waheed, Umair bin

2015-03-30

Computation of first-arrival traveltimes for quasi-P waves in the presence of anisotropy is important for high-end near-surface modeling, microseismic-source localization, and fractured-reservoir characterization - and it requires solving an anisotropic eikonal equation. Anisotropy deviating from elliptical anisotropy introduces higher order nonlinearity into the eikonal equation, which makes solving the eikonal equation a challenge. We addressed this challenge by iteratively solving a sequence of simpler tilted elliptically anisotropic eikonal equations. At each iteration, the source function was updated to capture the effects of the higher order nonlinear terms. We used Aitken\\'s extrapolation to speed up convergence rate of the iterative algorithm. The result is an algorithm for computing first-arrival traveltimes in tilted anisotropic media. We evaluated the applicability and usefulness of our method on tilted transversely isotropic media and tilted orthorhombic media. Our numerical tests determined that the proposed method matches the first arrivals obtained by wavefield extrapolation, even for strongly anisotropic and highly complex subsurface structures. Thus, for the cases where two-point ray tracing fails, our method can be a potential substitute for computing traveltimes. The approach presented here can be easily extended to compute first-arrival traveltimes for anisotropic media with lower symmetries, such as monoclinic or even the triclinic media.

Dynamic performance of a C/C composite finger seal in a tilting mode

Directory of Open Access Journals (Sweden)

Hailin ZHAO

2017-08-01

Full Text Available The complex operating state of aeroengines has an impact on the performance of finger seals. However, little work has been focused on the issue and the dynamic performance of finger seals is also rarely studied. Therefore, a distributed mass equivalent model considering working conditions is proposed in this paper for solving the existing problems. The effects of the fiber bundle density and the preparation direction of the fiber bundle of a C/C composite on the dynamic performance of a finger seal are investigated in rotor tilt based on the proposed model. The difference between the C/C composite finger seal performances under the rotor precession and nutation tilt cases is also investigated. The results show that the fiber bundle density and the preparation direction of the fiber bundle have an influence on the dynamic performance of the finger seal as rotor tilt is considered, and the dynamic performance of the finger seal is different in the two kinds of tilting modes. In addition, a novel method for design of finger seals is presented based on the contact pressure between finger boots and the rotor. Finger seals with good leakage rates and low wear can be acquired in this method.

Automatic Loss Adjustment for CDMA2000 and 1xEV-DO Standard for Downlink and Uplink

Directory of Open Access Journals (Sweden)

Jiri Kominek

2014-01-01

Full Text Available The functional and thermal testing of the mobile phone is always performed under various conditions that vary in terms of the connection between the DUT (Device Under Test and the measuring instrument. To achieve repeatable measurements under such conditions, it is necessary to adjust uplink and downlink loss using the instrument's external attenuation. While for GSM, WCDMA and LTE this is a relatively easy task, CDMA2000 and 1xEV-DO make automation of the adjustment process somewhat challenging due to the nature of the CDMA standard. An especially forward link is more complicated as those tests are run in signaling mode and not all instruments provide an FER value measured by an MS. This paper describes the algorithm for forward link loss adjustment and its implementation using Rohde & Schwarz CMW500.

The impact of gravity during head-up tilt

DEFF Research Database (Denmark)

Ottesen, Johnny T.; Olufsen, Mette; Smith, Brittany

2011-01-01

The impact of gravity during head-up tilt, a test often used in the clinic to diagnose patients who suffer from dizziness or frequent episodes of syncope, is not well described. This study uses mathematical modeling to analyze experimental blood pressure data measured at the level of the aorta an...

Establishment of Approximate Analytical Model of Oil Film Force for Finite Length Tilting Pad Journal Bearings

Directory of Open Access Journals (Sweden)

Yongliang Wang

2015-01-01

Full Text Available Tilting pad bearings offer unique dynamic stability enabling successful deployment of high-speed rotating machinery. The model of dynamic stiffness, damping, and added mass coefficients is often used for rotordynamic analyses, and this method does not suffice to describe the dynamic behaviour due to the nonlinear effects of oil film force under larger shaft vibration or vertical rotor conditions. The objective of this paper is to present a nonlinear oil force model for finite length tilting pad journal bearings. An approximate analytic oil film force model was established by analysing the dynamic characteristic of oil film of a single pad journal bearing using variable separation method under the dynamic π oil film boundary condition. And an oil film force model of a four-tilting-pad journal bearing was established by using the pad assembly technique and considering pad tilting angle. The validity of the model established was proved by analyzing the distribution of oil film pressure and the locus of journal centre for tilting pad journal bearings and by comparing the model established in this paper with the model established using finite difference method.

The alignment of smectic A liquid crystals with director tilt on the boundaries

International Nuclear Information System (INIS)

Stewart, I W

2007-01-01

Equilibrium solutions are presented for smectic A liquid crystals in which the usual director n and unit layer normal a do not necessarily coincide. Previous applications often equate n with a; the model in this paper allows n and a to differ and has been motivated by the recent investigations of Auernhammer et al (2000 Rheol. Acta 39 215-22, 2002 Phys. Rev. E 66 061707), Soddemann et al (2004 Eur. Phys. J. E 13 141-51) and Stewart (2007 Contin. Mech. Thermodyn. 18 343-60). The two experimental geometries studied consist of planar homeotropically aligned smectic layers and 'bookshelf' aligned layers. In both cases a director tilt at the boundaries will be imposed. Solutions to the fully nonlinear bookshelf problem where both the director and the layer normal can vary with an element of decoupling are presented and are particularly relevant to the experimental observations of Elston (1994 Liq. Cryst. 16 151-7); there are two boundary layer effects, as will be discussed, that are related to the biasing of the director towards the smectic A phase and the reorientation of the smectic layers themselves

The alignment of smectic A liquid crystals with director tilt on the boundaries

Energy Technology Data Exchange (ETDEWEB)

Stewart, I W [Department of Mathematics, University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH (United Kingdom)

2007-05-18

Equilibrium solutions are presented for smectic A liquid crystals in which the usual director n and unit layer normal a do not necessarily coincide. Previous applications often equate n with a; the model in this paper allows n and a to differ and has been motivated by the recent investigations of Auernhammer et al (2000 Rheol. Acta 39 215-22, 2002 Phys. Rev. E 66 061707), Soddemann et al (2004 Eur. Phys. J. E 13 141-51) and Stewart (2007 Contin. Mech. Thermodyn. 18 343-60). The two experimental geometries studied consist of planar homeotropically aligned smectic layers and 'bookshelf' aligned layers. In both cases a director tilt at the boundaries will be imposed. Solutions to the fully nonlinear bookshelf problem where both the director and the layer normal can vary with an element of decoupling are presented and are particularly relevant to the experimental observations of Elston (1994 Liq. Cryst. 16 151-7); there are two boundary layer effects, as will be discussed, that are related to the biasing of the director towards the smectic A phase and the reorientation of the smectic layers themselves.

Crystal structure study of dielectric oxynitride perovskites La{sub 1−x}Sr{sub x}TiO{sub 2+x}N{sub 1−x} (x=0, 0.2)

Energy Technology Data Exchange (ETDEWEB)

Habu, Daiki; Masubuchi, Yuji [Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan); Torii, Shuki [Institute of Materials Structure Science, High Energy Accelerator Organization, 203-1, Shirakata, Tokai-Mura, Naka-gun, Ibaraki 319-1106 (Japan); Kamiyama, Takashi [Institute of Materials Structure Science, High Energy Accelerator Organization, 203-1, Shirakata, Tokai-Mura, Naka-gun, Ibaraki 319-1106 (Japan); School of High Energy Accelerator Science, Sokendai (The Graduate University for Advanced Studies), Tokai 319-1106 (Japan); Kikkawa, Shinichi, E-mail: kikkawa@eng.hokudai.ac.jp [Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan)

2016-05-15

As is the case with SrTaO{sub 2}N, both cis-ordering of nitride anions and octahedral titling are also preferable in La{sub 1−x}Sr{sub x}TiO{sub 2+x}N{sub 1−x} (x=0, 0.2) oxynitride perovskites. A larger dielectric constant of ε{sub r}≈5.0×10{sup 3} was estimated for the pure oxynitride with x=0.2, compared with ε{sub r}≈750 for the product with x=0, by extrapolating the ε{sub r} values obtained from powders mixed with paraffin at various mixing ratios. The crystal structure of x=0.2 with larger tolerance factor than x=0 increased the octahedral tilting, which contributes to the increased dielectric constant. The increased dielectric constant supports the exchange mechanism for the dielectric property between two kinds of –Ti–N– helical coils (clockwise and anticlockwise) derived from the above cis-ordering of nitride anions. - Graphical abstract: Very large dielectric constant values were estimated for La{sub 1−x}Sr{sub x}TiO{sub 2+x}N{sub 1−x}; ε{sub r}≈5.0×10{sup 3} in x=0.2 and ε{sub r}≈750 in x=0. - Highlights: • Cis-configuration of nitride anions was confirmed in La{sub 1−x}Sr{sub x}TiO{sub 2+x}N{sub 1−x} (x=0, 0.2). • Dielectric constant values were estimated to be 750 for x=0 and 5.0×10{sup 3} for x=0.2, respectively. • The large dielectric property is to the exchange mechanism between clockwise and anticlockwise –Ti–N– coil motifs.

Flow tilt angles near forest edges – Part 1: Sonic anemometry

Directory of Open Access Journals (Sweden)

E. Dellwik

2010-05-01

Full Text Available An analysis of flow tilt angles from a fetch-limited beech forest site with clearings is presented in the context of vertical advection of carbon dioxide. Flow angles and vertical velocities from two sonic anemometers by different manufacturers were analyzed. Instead of using rotations, where zero-flow angles were assumed for neutral flow, the data was interpreted in relation to upstream and downstream forest edges.

Uncertainties caused by flow distortion, vertical misalignment and limited sampling time (statistical uncertainty were evaluated and found to be highly significant. Since the attack angle distribution of the wind on the sonic anemometer is a function of atmospheric stratification, an instrumental error caused by imperfect flow distortion correction is also a function of the atmospheric stratification. In addition, it is discussed that the sonic anemometers have temperature dependent off-sets. These features of the investigated sonic anemometers make them unsuitable for measuring vertical velocities over highly turbulent forested terrain. By comparing the sonic anemometer results to that of a conically scanning Doppler lidar (Dellwik et al., 2010b, sonic anemometer accuracy for measuring mean flow tilt angles was estimated to between 2° and 3°. Use of planar fit algorithms, where the mean vertical velocity is calculated as the difference between the neutral and non-neutral flow, does not solve this problem of low accuracy and is not recommended.

Because of the large uncertainties caused by flow distortion and vertical alignment, it was only possible to a limited extent to relate sonic anemometer flow tilt angles to upwind forest edges, but the results by the lidar indicated that an internal boundary layer affect flow tilt angles at 21m above the forest. This is in accordance with earlier studies at the site.

Since the mean flow tilt angles do not follow the terrain, an estimate of the vertical advection

X-ray diffraction and X-ray standing-wave study of the lead stearate film structure

Energy Technology Data Exchange (ETDEWEB)

Blagov, A. E.; Dyakova, Yu. A.; Kovalchuk, M. V.; Kohn, V. G.; Marchenkova, M. A.; Pisarevskiy, Yu. V.; Prosekov, P. A., E-mail: prosekov@crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2016-05-15

A new approach to the study of the structural quality of crystals is proposed. It is based on the use of X-ray standing-wave method without measuring secondary processes and considers the multiwave interaction of diffraction reflections corresponding to different harmonics of the same crystallographic reflection. A theory of multiwave X-ray diffraction is developed to calculate the rocking curves in the X-ray diffraction scheme under consideration for a long-period quasi-one-dimensional crystal. This phase-sensitive method is used to study the structure of a multilayer lead stearate film on a silicon substrate. Some specific structural features are revealed for the surface layer of the thin film, which are most likely due to the tilt of the upper layer molecules with respect to the external normal to the film surface.

Correction of Pelvic Tilt and Pelvic Rotation in Cup Measurement after THA - An Experimental Study.

Science.gov (United States)

Schwarz, Timo Julian; Weber, Markus; Dornia, Christian; Worlicek, Michael; Renkawitz, Tobias; Grifka, Joachim; Craiovan, Benjamin

2017-09-01

Purpose  Accurate assessment of cup orientation on postoperative pelvic radiographs is essential for evaluating outcome after THA. Here, we present a novel method for correcting measurement inaccuracies due to pelvic tilt and rotation. Method  In an experimental setting, a cup was implanted into a dummy pelvis, and its final position was verified via CT. To show the effect of pelvic tilt and rotation on cup position, the dummy was fixed to a rack to achieve a tilt between + 15° anterior and -15° posterior and 0° to 20° rotation to the contralateral side. According to Murray's definitions of anteversion and inclination, we created a novel corrective procedure to measure cup position in the pelvic reference frame (anterior pelvic plane) to compensate measurement errors due to pelvic tilt and rotation. Results  The cup anteversion measured on CT was 23.3°; on AP pelvic radiographs, however, variations in pelvic tilt (± 15°) resulted in anteversion angles between 11.0° and 36.2° (mean error 8.3°± 3.9°). The cup inclination was 34.1° on CT and ranged between 31.0° and 38.7° (m. e. 2.3°± 1.5°) on radiographs. Pelvic rotation between 0° and 20° showed high variation in radiographic anteversion (21.2°-31.2°, m. e. 6.0°± 3.1°) and inclination (34.1°-27.2°, m. e. 3.4°± 2.5°). Our novel correction algorithm for pelvic tilt reduced the mean error in anteversion measurements to 0.6°± 0.2° and in inclination measurements to 0.7° (SD± 0.2). Similarly, the mean error due to pelvic rotation was reduced to 0.4°± 0.4° for anteversion and to 1.3°± 0.8 for inclination. Conclusion  Pelvic tilt and pelvic rotation may lead to misinterpretation of cup position on anteroposterior pelvic radiographs. Mathematical correction concepts have the potential to significantly reduce these errors, and could be implemented in future radiological software tools. Key Points   · Pelvic tilt and rotation influence cup

A tilted fiber-optic plate coupled CCD detector for high resolution neutron imaging

Energy Technology Data Exchange (ETDEWEB)

Kim, Jongyul; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Jongyul; Hwy, Limchang; Kim, Taejoo; Lee, Kyehong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Seungwook [Pusan National Univ., Pusan (Korea, Republic of)

2013-05-15

One of these efforts is that a tilted scintillator geometry and lens coupled CCD detector for neutron imaging system were used to improve spatial resolution in one dimension. The increased spatial resolution in one dimension was applied to fuel cell study. However, a lens coupled CCD detector has lower sensitivity than a fiber-optic plate coupled CCD detector due to light loss. In this research, a tilted detector using fiber-optic plate coupled CCD detector was developed to improve resolution and sensitivity. In addition, a tilted detector can prevent an image sensor from direct radiation damage. Neutron imaging has been used for fuel cell study, lithium ion battery study, and many scientific applications. High quality neutron imaging is demanded for more detailed studies of applications, and spatial resolution should be considered to get high quality neutron imaging. Therefore, there were many efforts to improve spatial resolution.

Current Measurements and Overwash Monitoring Using Tilt Current Meters in Three Coastal Environments

Science.gov (United States)

Lowell, N. S.; Sherwood, C. R.; Decarlo, T. M.; Grant, J. R.

2014-12-01

Tilt Current Meters (TCMs) provide accurate, cost effective measurements of near-bottom current velocities. Many studies in coastal environments require current measurements, which are frequently made with Acoustic Doppler Profilers (ADPs). ADPs are expensive, however, and may not be suitable for locations where there is significant risk of damage, loss, or theft or where a large spatial array of measurements is required. TCMs, by contrast, are smaller, less expensive, and easier to deploy. This study tested TCMs in three sites to determine their suitability for use in research applications. TCMs are based on the drag-tilt principle, where the instrument tilts in response to current. The meter consists of a buoyant float with an onboard accelerometer, three-axis tilt sensor, three-axis magnetometer (compass), and a data logger. Current measurements are derived by post processing the tilt and compass values and converting them to velocity using empirical calibration data. Large data-storage capacity (4 GB) and low power requirements allow long deployments (many months) at high sample rates (16 Hz). We demonstrate the utility of TCM current measurements on a reef at Dongsha Atoll in the South China Sea, and in Vineyard Sound off Cape Cod, where the TCM performance was evaluated against ADP measurements. We have also used the TCM to record waves during an overwash event on a Cape Cod barrier beach during a winter storm. The TCM recorded waves as they came through the overwash channel, and the data were in agreement with the water-level record used as a reference. These tests demonstrate that TCMs may be used in a variety of near shore environments and have the potential to significantly increase the density of meters in future studies were current measurements are required.

NASA Chandra X-ray Observatory Selected as Editor's Choice in 2000 Discover Magazine Awards for Technological Innovation

Science.gov (United States)

2000-06-01

The Chandra X-ray Observatory, NASA's newest and most powerful X-ray space telescope, has been selected as the winner of the Editor's Choice category of the 2000 Discover Magazine Awards for Technological Innovation. The team of government, industry, university and research institutions that designed, built and deployed Chandra for NASA's Marshall Space Flight Center, Huntsville, Ala, will be formally recognized June 24 at a gala awards celebration at Epcot at the Walt Disney World Resort in Orlando, Fl. Dr. Harvey Tananbaum, director of the Smithsonian Astrophysical Observatory's Chandra X-ray Science Center, Cambridge, Mass., which conducts the Chandra science mission for NASA, will receive the award on behalf of the team. "Chandra has opened a new window for astronomers into the universe of high-energy cosmic events such as pulsars, supernova remnants and black holes," said Tananbaum. "We're now able to create spectacularly detailed images of celestial phenomena whose mere existence we could only hypothesize before." Among Chandra's most significant discoveries to date, he lists the detection of a giant ring around the heart of the Crab Nebula, details of the shock wave created by an exploding star and resolution of the high-energy X-ray "glow" in the universe into millions of specific light sources. "The successful launch, deployment and on-orbit operations of NASA's Chandra X-ray Observatory is a testament to the solid partnership between TRW, NASA and the science community that has been enabling NASA's most important space science missions for the past 40 years," said Timothy W. Hannemann, executive vice president and general manager, TRW Space & Electronics Group. "The extraordinary images that Chandra is delivering daily speaks loudly not only to the quality of the science instruments on board, but also to the engineering talents and dedication to mission success exhibited by every member of NASA's Chandra mission team." Chandra, named in honor of Nobel

The perception of roll tilt in pilots during a simulated coordinated turn in a gondola centrifuge.

Science.gov (United States)

Tribukait, Arne; Grönkvist, Mikael; Eiken, Ola

2011-05-01

It has previously been reported that nonpilots underestimate the roll tilt angle after acceleration in a gondola centrifuge. The aim of the present work was to elucidate the significance of flight experience for roll tilt perception based on vestibular information. The subjective visual horizontal (SVH) was measured by means of an adjustable luminous line in darkness. Eight nonpilots (N), nine fighter pilots (F), and eight helicopter pilots (H) underwent two centrifuge runs (2 G, 5 min) heading forward and backward, respectively. The roll position of the gondola (60 degrees at 2 G) was controlled so that the subject was always upright with respect to the gravitoinertial force. Upon acceleration of the centrifuge there was a tilt of the SVH in a direction compensatory to the inclination of the gondola. This tilt was larger in the forward position [N: 17.2 +/- 6.4 degrees, F: 31.2 +/- 16.4 degrees, H: 33.6 +/- 18.2 degrees (means +/- SD)] than in the backward position (N: -5.0 +/- 6.8 degrees, F: -12.2 +/- 17.4 degrees, H: -10.4 +/- 15.4 degrees). In N the tilt declined with time, approaching zero by the end of the 2-G plateau. In the pilots it was significantly larger and did not decline. Flight experience results in an increased ability to perceive the roll tilt during movement along a curved path. That this can be revealed in a centrifuge might suggest that acceleration of the centrifuge constitutes a movement pattern which is similar, from a vestibular point of view, to that of an airplane entering a coordinated turn.

Fractional Josephson vortices at YBa$_2$Cu$_3$O$_{7-x}$ grain boundaries

OpenAIRE

Mints, R. G.; Papiashvili, Ilya

2001-01-01

We report numerical simulations of magnetic flux patterns in asymmetric 45$^{\\circ}$ [001]-tilt grain boundaries in YBa$_2$Cu$_3$O$_{7-x}$ superconducting films. The grain boundaries are treated as Josephson junctions with the critical current density $j_c(x)$ alternating along the junctions. We demonstrate the existence of Josephson vortices with fractional flux quanta for both periodic and random $j_c(x)$. A method is proposed to extract fractional vortices from experimental flux patterns.

Global, direct and diffuse solar radiation on horizontal and tilted surfaces in Jeddah, Saudi Arabia

International Nuclear Information System (INIS)

El-Sebaii, A.A.; Al-Hazmi, F.S.; Al-Ghamdi, A.A.; Yaghmour, S.J.

2010-01-01

The measured data of global and diffuse solar radiation on a horizontal surface, the number of bright sunshine hours, mean daily ambient temperature, maximum and minimum ambient temperatures, relative humidity and amount of cloud cover for Jeddah (lat. 21 o 42'37''N, long. 39 o 11'12''E), Saudi Arabia, during the period (1996-2007) are analyzed. The monthly averages of daily values for these meteorological variables have been calculated. The data are then divided into two sets. The sub-data set I (1996-2004) are employed to develop empirical correlations between the monthly average of daily global solar radiation fraction (H/H 0 ) and the various weather parameters. The sub-data set II (2005-2007) are then used to evaluate the derived correlations. Furthermore, the total solar radiation on horizontal surfaces is separated into the beam and diffuses components. Empirical correlations for estimating the diffuse solar radiation incident on horizontal surfaces have been proposed. The total solar radiation incident on a tilted surface facing south H t with different tilt angles is then calculated using both Liu and Jordan isotropic model and Klucher's anisotropic model. It is inferred that the isotropic model is able to estimate H t more accurate than the anisotropic one. At the optimum tilt angle, the maximum value of H t is obtained as ∼36 (MJ/m 2 day) during January. Comparisons with 22 years average data of NASA SSE Model showed that the proposed correlations are able to predict the total annual energy on horizontal and tilted surfaces in Jeddah with a reasonable accuracy. It is also found that at Jeddah, the solar energy devices have to be tilted to face south with a tilt angle equals the latitude of the place in order to achieve the best performance all year round.

HREM investigation of the structure of the Σ5(310)/[001] symmetric tilt grain boundaries in Nb

International Nuclear Information System (INIS)

King, W.E.; Compbell, G.H.; Coombs, A.; Ruehle, M.

1991-01-01

This paper reports on atomistic simulations using interatomic potentials for Nb developed employing the embedded atom method (EAM) and the model generalized pseudopotential theory (MGPT) that have indicated a possible cusp at the Σ5 (310) orientation in the energy vs tilt angle curves for left-angle 001 right-angle symmetric tilt grain boundaries. In addition, the most stable structure predicted using EAM exhibits shifts of one crystal relative to the other along the tilt axis and along the direction perpendicular to the tilt axis lying in the boundary plane. The structure predicted using the MGPT was mirror symmetric across the plane of the grain boundary. This boundary has been prepared for experimental study using the ultra high vacuum diffusion bonding method. A segment of this boundary has been studied using high resolution electron microscopy

Monte Carlo modelling of germanium crystals that are tilted and have rounded front edges

International Nuclear Information System (INIS)

Gasparro, Joel; Hult, Mikael; Johnston, Peter N.; Tagziria, Hamid

2008-01-01

Gamma-ray detection efficiencies and cascade summing effects in germanium detectors are often calculated using Monte Carlo codes based on a computer model of the detection system. Such a model can never fully replicate reality and it is important to understand how various parameters affect the results. This work concentrates on quantifying two issues, namely (i) the effect of having a Ge-crystal that is tilted inside the cryostat and (ii) the effect of having a model of a Ge-crystal with rounded edges (bulletization). The effect of the tilting is very small (in the order of per mille) when the tilting angles are within a realistic range. The effect of the rounded edges is, however, relatively large (5-10% or higher) particularly for gamma-ray energies below 100 keV

Monte Carlo modelling of germanium crystals that are tilted and have rounded front edges

Energy Technology Data Exchange (ETDEWEB)

Gasparro, Joel [EC-JRC-IRMM, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Hult, Mikael [EC-JRC-IRMM, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium)], E-mail: mikael.hult@ec.europa.eu; Johnston, Peter N. [Applied Physics, Royal Melbourne Institute of Technology, GPO Box 2476V, Melbourne 3001 (Australia); Tagziria, Hamid [EC-JRC-IPSC, Institute for the Protection and the Security of the Citizen, Via E. Fermi 1, I-21020 Ispra (Vatican City State, Holy See,) (Italy)

2008-09-01

Gamma-ray detection efficiencies and cascade summing effects in germanium detectors are often calculated using Monte Carlo codes based on a computer model of the detection system. Such a model can never fully replicate reality and it is important to understand how various parameters affect the results. This work concentrates on quantifying two issues, namely (i) the effect of having a Ge-crystal that is tilted inside the cryostat and (ii) the effect of having a model of a Ge-crystal with rounded edges (bulletization). The effect of the tilting is very small (in the order of per mille) when the tilting angles are within a realistic range. The effect of the rounded edges is, however, relatively large (5-10% or higher) particularly for gamma-ray energies below 100 keV.

YBa2Cu3O7-x 45 degree [001] tilt grain boundaries induced by controlled low-energy sputtering of MgO substrates: Transport properties and atomic-scale structure

International Nuclear Information System (INIS)

Vuchic, B.V.; Merkle, K.L.; Funkhouser, J.W.; Bucholz, D.B.; Dean, K.A.; Chang, R.P.H.; Marks, L.D.

1994-10-01

Grain boundaries can act as weak links in the high T c materials. If properly controlled, these grain boundaries can be used in various device applications. We have been able to reproducibly form 45 degree [001] tilt grain boundary junctions in YBa 2 Cu 3 0 7-x thin films. The films were grown on MgO substrates using a pre-growth substrate treatment. A low energy broad beam Argon ion source was used to irradiate a select region of (100) MgO substrates. The film on the milled portion of the substrate grows predominantly with a grain orientation rotated 45 degree about the c-axis with respect to the grain on the unmilled portion. Backscattered electron Kikuchi patterns have been used to confirm that the rotation occurs across the entire milled portion of the substrate. Transport properties of these films are discussed and related to high resolution electron microstructural and microchemical analyses of the grain boundaries. This technique has potential use in device applications as a method for controlled grain boundary engineering

Cost characteristics of tilt-rotor, conventional air and high speed rail short-haul intercity passenger service

Science.gov (United States)

Schoendorfer, David L.; Morlok, Edward K.

1985-01-01

The cost analysis done to support an assessment of the potential for a small tilt-rotor aircraft to operate in short-haul intercity passenger service is described in detail. Anticipated costs of tilt-rotor air service were compared to the costs of two alternatives: conventional air and high speed rail (HSR). Costs were developed for corridor service, varying key market characteristics including distance, passenger volumes, and minimum frequency standards. The resulting cost vs output information can then be used to compare modal costs for essentially identical service quality and passenger volume or for different service levels and volumes for each mode, as appropriate. Extensive sensitivity analyses are performed. The cost-output features of these technologies are compared. Tilt-rotor is very attractive compared to HSR in terms of costs over the entire range of volume. It also has costs not dramatically different from conventional air, but tilt-rotor costs are generally higher. Thus some of its other advantages, such as the VTOL capability, must offset the cost disadvantage for it to be a preferred or competitive mode in any given market. These issues are addressed in the companion report which considers strategies for tilt-rotor development in commercial air service.

Dynamic characteristics of polymer faced tilting pad journal bearings

DEFF Research Database (Denmark)

Simmons, Gregory F.; Cerda Varela, Alejandro Javier; Santos, Ilmar

2014-01-01

Dynamic characteristics of polymer faced tilting pad journal bearings are presented. Investigations are conducted using a single pad, load on pad configuration over a range of shaft speeds and loads. Two polyether ether ketone (PEEK) faced pads, one polytetrafluoroethylene (PTFE) faced pad and two...

The effects of lateral head tilt on ocular astigmatic axis

Directory of Open Access Journals (Sweden)

Hamid Fesharaki

2014-01-01

Conclusion: Any minimal angle of head tilt may cause erroneous measurement of astigmatic axis and should be avoided during refraction. One cannot rely on the compensatory function of ocular counter-torsion during the refraction.

Design and construction of an optical test bed for LISA imaging systems and tilt-to-length coupling

International Nuclear Information System (INIS)

Chwalla, M; Fitzsimons, E; Danzmann, K; Fernández Barranco, G; Gerberding, O; Heinzel, G; Lieser, M; Schuster, S; Schwarze, T S; Tröbs, M; Zwetz, M; Killow, C J; Perreur-Lloyd, M; Robertson, D I; Ward, H

2016-01-01

The laser interferometer space antenna (LISA) is a future space-based interferometric gravitational-wave detector consisting of three spacecraft in a triangular configuration. The interferometric measurements of path length changes between satellites will be performed on optical benches in the satellites. Angular misalignments of the interfering beams couple into the length measurement and represent a significant noise source. Imaging systems will be used to reduce this tilt-to-length coupling. We designed and constructed an optical test bed to experimentally investigate tilt-to-length coupling. It consists of two separate structures, a minimal optical bench and a telescope simulator. The minimal optical bench comprises the science interferometer where the local laser is interfered with light from a remote spacecraft. In our experiment, a simulated version of this received beam is generated on the telescope simulator. The telescope simulator provides a tilting beam, a reference interferometer and an additional static beam as a phase reference. The tilting beam can either be a flat-top beam or a Gaussian beam. We avoid tilt-to-length coupling in the reference interferometer by using a small photo diode placed at an image of the beam rotation point. We show that the test bed is operational with an initial measurement of tilt-to-length coupling without imaging systems. Furthermore, we show the design of two different imaging systems whose performance will be investigated in future experiments. (paper)

Quantum capacitance in topological insulators under strain in a tilted magnetic field

KAUST Repository

Tahir, M.

2012-12-06

Topological insulators exhibit unique properties due to surface states of massless Dirac fermions with conserved time reversal symmetry. We consider the quantum capacitance under strain in an external tilted magnetic field and demonstrate a minimum at the charge neutrality point due to splitting of the zeroth Landau level. We also find beating in the Shubnikov de Haas oscillations due to strain, which originate from the topological helical states. Varying the tilting angle from perpendicular to parallel washes out these oscillations with a strain induced gap at the charge neutrality point. Our results explain recent quantum capacitance and transport experiments.

Quantum capacitance in topological insulators under strain in a tilted magnetic field

KAUST Repository

Tahir, M.; Schwingenschlö gl, Udo

2012-01-01

Topological insulators exhibit unique properties due to surface states of massless Dirac fermions with conserved time reversal symmetry. We consider the quantum capacitance under strain in an external tilted magnetic field and demonstrate a minimum at the charge neutrality point due to splitting of the zeroth Landau level. We also find beating in the Shubnikov de Haas oscillations due to strain, which originate from the topological helical states. Varying the tilting angle from perpendicular to parallel washes out these oscillations with a strain induced gap at the charge neutrality point. Our results explain recent quantum capacitance and transport experiments.

Design Optimization of Tilting-Pad Journal Bearing Using a Genetic Algorithm

Directory of Open Access Journals (Sweden)

Hamit Saruhan

2004-01-01

Full Text Available This article focuses on the use of genetic algorithms in developing an efficient optimum design method for tilting pad bearings. The approach optimizes based on minimum film thickness, power loss, maximum film temperature, and a global objective. Results for a five tilting-pad preloaded bearing are presented to provide a comparison with more traditional optimum design methods such as the gradient-based global criterion method, and also to provide insight into the potential of genetic algorithms in the design of rotor bearings. Genetic algorithms are efficient search techniques based on the idea of natural selection and genetics. These robust methods have gained recognition as general problem solving techniques in many applications.

The influence of a tilt training programme on the renin-angiotensin-aldosterone system activity in patients with vasovagal syncope.

Science.gov (United States)

Gajek, Jacek; Zyśko, Dorota; Krzemińska, Sylwia; Mazurek, Walentyna

2009-08-01

We assessed the influence of short-term and long-term tilt training on the activity of the renin-angiotensin-aldosterone system (RAAS) in vasovagal patients. Thirty-nine patients (28 F, 11 M) aged 39.7 +/- 11.2 years with a history of vasovagal syncope and a positive head-up tilt test (HUT) were studied. Blood samples for plasma renin activity (PRA) and aldosterone (ALDO) concentration were drawn at the baseline, immediately after HUT and 10 min after HUT, during the diagnostic, the negative short-term (2-5 days) follow-up HUT and long-term (1-3 months) follow-up HUT. Tilt training was started after diagnostic HUT. In diagnostic HUT, PRA increased significantly immediately after HUT comparing to the baseline, during recovery the values did not change. ALDO concentration increased after HUT comparing to baseline and further increased during recovery. After short-term tilt training, PRA and ALDO concentrations did not significantly change compared to their corresponding values in diagnostic HUT. After long-term tilt training, PRA did not significantly change compared to the values in the diagnostic and short-term follow-up HUT. ALDO concentration also did not change significantly at the baseline and immediately after HUT, and 10 min after HUT ALDO concentration was significantly lower than after diagnostic HUT. Tilt training changes the response of RAAS to the prolonged orthostasis in vasovagal patients. The coupling between PRA and ALDO after diagnostic HUT has been found to be altered and the physiological relationship was restored after long-term tilt training. The beneficial effect of tilt training depends partially on changed RAAS activation.

Tilted axis rotation in odd-odd {sup 164}Tm

Energy Technology Data Exchange (ETDEWEB)

Reviol, W.; Riedinger, L.L.; Wang, X.Z.; Zhang, J.Y. [Univ. of Tennessee, Knoxville, TN (United States)] [and others

1996-12-31

Ten band structures are observed in {sup 164}Tm, among them sets of parallel and anti-parallel couplings of the proton and neutron spins. The Tilted Axis Cranking scheme is applied for the first time to an odd-odd nucleus in a prominent region of nuclear deformation.

Tidal tilts observations in the Gran Sasso underground laboratory

International Nuclear Information System (INIS)

Iafolla, V.; Nozzoli, S.; Milyukov, V.

2001-01-01

A new tilt meter, based on the technology for building a space-borne high-sensitivity accelerometer and manufactured at IFSI/CNR, has a been operating during several years in the INFN Gran Sasso underground laboratory. The results of the analysis of a three-year data set, processed with the program package ETERNA, to estimate earth tidal parameters are reported. For the best series of data (1998) tide measurement accuracies are: 0.5-1% for the M 2 (lunar principal) amplitude and 3-4% for the O 1 (lunar declination) amplitude. The tilt meter installed at a depth of 1400 m shows no clear evidence of meteorological effects. Observed tidal parameters are compared with theoretical tidal parameters predicted for a non-hydrostatic inelastic Earth model and demonstrate good agreement for the M 2 component. Due to the high accuracy of the tidal components prediction (better than 1%) tidal measurements were used to estimate the long-term stability of the instrument response

Friction and Lubrication of Large Tilting-Pad Thrust Bearings

Directory of Open Access Journals (Sweden)

Michał Wasilczuk

2015-04-01

Full Text Available Fluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient, despite a very low coefficient of friction dissipation of energy being noticeable, especially in large bearings. Lubricating systems of large tilting pad thrust bearings utilized in large, vertical shaft hydrogenerators are presented in this paper. A large amount of heat is generated due to viscous shearing of the lubricant large tilting pad thrust bearings, and this requires systems for forced cooling of the lubricant. In the dominant bath lubrication systems, cooling is realized by internal coolers or external cooling systems, with the latter showing some important advantages at the cost of complexity and also, potentially, lower reliability. Substantial losses in the bearings, reaching 1 MW in extreme cases, are a good motivation for the research and development aimed at reducing them. Some possible methods and their potential efficiency, along with some effects already documented, are also described in the paper.

SINERGI ISO 9001:2000 - CMMI PADA INDUSTRI PENGEMBANG PERANGKAT LUNAK

Directory of Open Access Journals (Sweden)

Leo Willyanto Santoso

2005-01-01

Full Text Available All sectors of society including softwere industry, have a big concern about quality, both of product quality and service quality. The need to manage risk, has a strong relation with quality and increases system complexity. Standarization in determining quality, ISO is a must for all software developer. If we study further, ISO 9001:2000 still has some weakness especially for implementation in software product. This paper presents a comparative analysis of quality approaches to risk management. This paper also provide a general overview of all the risks aspects treated in ISO 9001:2000 standards and CMMI model version 1.1. In this research, we obtain a strategy to implement ISO 9001:2000 and CMMI together when we make a planing to increase software process. Besides it produces analysis how to change position from ISO 9001:2000 to CMMI. In the implementation on software industry PT 'X', obtain get various benefits that has never been obtained before. Abstract in Bahasa Indonesia : Semua hal dalam hidup ini selalu memperhatikan masalah kualitas, baik itu berupa kualitas produk ataupun kualitas layanan. Pada industri perangkat lunak, hal ini tidak dibedakan, kebutuhan untuk menghasilkan produk yang berkualitas akan meningkatkan kekompleksan dari sebuah sistem. Standarisasi dalam penentuan kualitas, ISO sudah menjadi keharusan bagi para pengembang perangkat lunak. Apabila diteliti lebih lanjut, ISO 9001:2000 masih mempunyai banyak kekurangan, khususnya untuk diaplikasikan dalam produk perangkat lunak.Pada penelitian ini, akan dibahas analisis perbandingan dengan melakukan pendekatan kualitas untuk meningkatkan proses perangkat lunak dengan melakukan mapping antara ISO 9001:2000 dengan CMMI. Hal-hal yang dibahas berupa aspek-aspek dari standard ISO dan CMMI versi 1.1. Pada penelitian ini, dapat diperoleh strategi untuk menerapkan ISO 9001:2000 dan CMMI secara sinergi ketika merencanakan untuk melakukan peningkatan proses perangkat lunak. Selain itu

Spatial Coding of Eye Movements Relative to Perceived Orientations During Roll Tilt with Different Gravitoinertial Loads

Science.gov (United States)

Wood, Scott; Clement, Gilles

2013-01-01

This purpose of this study was to examine the spatial coding of eye movements during roll tilt relative to perceived orientations while free-floating during the microgravity phase of parabolic flight or during head tilt in normal gravity. Binocular videographic recordings obtained in darkness from six subjects allowed us to quantify the mean deviations in gaze trajectories along both horizontal and vertical coordinates relative to the aircraft and head orientations. Both variability and curvature of gaze trajectories increased during roll tilt compared to the upright position. The saccades were less accurate during parabolic flight compared to measurements obtained in normal gravity. The trajectories of saccades along perceived horizontal orientations tended to deviate in the same direction as the head tilt, while the deviations in gaze trajectories along the perceived vertical orientations deviated in the opposite direction relative to the head tilt. Although subjects were instructed to look off in the distance while performing the eye movements, fixation distance varied with vertical gaze direction independent of whether the saccades were made along perceived aircraft or head orientations. This coupling of horizontal vergence with vertical gaze is in a consistent direction with the vertical slant of the horopter. The increased errors in gaze trajectories along both perceived orientations during microgravity can be attributed to the otolith's role in spatial coding of eye movements.

Accurate marker-free alignment with simultaneous geometry determination and reconstruction of tilt series in electron tomography

International Nuclear Information System (INIS)

Winkler, Hanspeter; Taylor, Kenneth A.

2006-01-01

An image alignment method for electron tomography is presented which is based on cross-correlation techniques and which includes a simultaneous refinement of the tilt geometry. A coarsely aligned tilt series is iteratively refined with a procedure consisting of two steps for each cycle: area matching and subsequent geometry correction. The first step, area matching, brings into register equivalent specimen regions in all images of the tilt series. It determines four parameters of a linear two-dimensional transformation, not just translation and rotation as is done during the preceding coarse alignment with conventional methods. The refinement procedure also differs from earlier methods in that the alignment references are now computed from already aligned images by reprojection of a backprojected volume. The second step, geometry correction, refines the initially inaccurate estimates of the geometrical parameters, including the direction of the tilt axis, a tilt angle offset, and the inclination of the specimen with respect to the support film or specimen holder. The correction values serve as an indicator for the progress of the refinement. For each new iteration, the correction values are used to compute an updated set of geometry parameters by a least squares fit. Model calculations show that it is essential to refine the geometrical parameters as well as the accurate alignment of the images to obtain a faithful map of the original structure

Endogenous indole-3-acetic acid and ethylene evolution in tilted Metasequoia glyptostroboides stems in relation to compression-wood formation.

Science.gov (United States)

Du, Sheng; Sugano, Mami; Tsushima, Miho; Nakamura, Teruko; Yamamoto, Fukuju

2004-04-01

Eight-year-old Metasequoia glyptostroboides seedlings were tilted at a 45 degrees angle to induce compression-wood formation on the lower side of the stems. After 2 weeks of treatment, half of the seedlings were sampled and the remaining half were tilted to the opposite orientation to exchange the upper and lower sides and were kept for 2 more weeks until sampled. Cambium-emitted ethylene was analyzed by gas chromatography with flame-ionization detection. Endogenous indole-3-acetic acid (IAA) was measured by gas chromatography-mass spectrometry. Tracheid production and compression-wood formation were determined by light microscopy. Anatomical studies showed that tracheid production was promoted and compression-wood tracheids always developed on the gravitationally lower side of tilted stems in both the original tilting and the subsequent reverse-tilting periods. These were accompanied by an increase in IAA content in and an accelerated ethylene-evolution rate from the cambial region of the same side.

A tip/tilt mirror with large dynamic range for the ESO VLT Four Laser Guide Star Facility

Science.gov (United States)

Rijnveld, N.; Henselmans, R.; Nijland, B.

2011-09-01

One of the critical elements in the Four Laser Guide Star Facility (4LGSF) for the ESO Very Large Telescope (VLT) is the Optical Tube Assembly (OTA), consisting of a stable 20x laser beam expander and an active tip/tilt mirror, the Field Selector Mechanism (FSM). This paper describes the design and performance testing of the FSM. The driving requirement for the FSM is its large stroke of +/-6.1 mrad, in combination with less than 1.5 μrad RMS absolute accuracy. The FSM design consists of a Zerodur mirror, bonded to a membrane spring and strut combination to allow only tip and tilt. Two spindle drives actuate the mirror, using a stiffness based transmission to increase resolution. Absolute accuracy is achieved with two differential inductive sensor pairs. A prototype of the FSM is realized to optimize the control configuration and measure its performance. Friction in the spindle drive is overcome by creating a local velocity control loop between the spindle drives and the shaft encoders. Accuracy is achieved by using a cascaded low bandwidth control loop with feedback from the inductive sensors. The pointing jitter and settling time of the FSM are measured with an autocollimator. The system performance meets the strict requirements, and is ready to be implemented in the first OTA.

Setup accuracy of stereoscopic X-ray positioning with automated correction for rotational errors in patients treated with conformal arc radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Soete, Guy; Verellen, Dirk; Tournel, Koen; Storme, Guy

2006-01-01

We evaluated setup accuracy of NovalisBody stereoscopic X-ray positioning with automated correction for rotational errors with the Robotics Tilt Module in patients treated with conformal arc radiotherapy for prostate cancer. The correction of rotational errors was shown to reduce random and systematic errors in all directions. (NovalisBody TM and Robotics Tilt Module TM are products of BrainLAB A.G., Heimstetten, Germany)

Profile stabilization of tilt mode in a Field Reversed Configuration

Energy Technology Data Exchange (ETDEWEB)

Cobb, J.W.; Tajima, T. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies; Barnes, D.C. [Los Alamos National Lab., NM (United States)

1993-06-01

The possibility of stabilizing the tilt mode in Field Reversed Configurations without resorting to explicit kinetic effects such as large ion orbits is investigated. Various pressure profiles, P({Psi}), are chosen, including ``hollow`` profiles where current is strongly peaked near the separatrix. Numerical equilibria are used as input for an initial value simulation which uses an extended Magnetohydrodynamic (MHD) model that includes viscous and Hall terms. Tilt stability is found for specific hollow profiles when accompanied by high values of separatrix beta, {beta}{sub sep}. The stable profiles also have moderate to large elongation, racetrack separatrix shape, and lower values of 3, average ratio of Larmor radius to device radius. The stability is unaffected by changes in viscosity, but the neglect of the Hall term does cause stable results to become marginal or unstable. Implications for interpretation of recent experiments are discussed.

Profile stabilization of tilt mode in a Field Reversed Configuration

International Nuclear Information System (INIS)

Cobb, J.W.; Tajima, T.

1993-06-01

The possibility of stabilizing the tilt mode in Field Reversed Configurations without resorting to explicit kinetic effects such as large ion orbits is investigated. Various pressure profiles, P(Ψ), are chosen, including ''hollow'' profiles where current is strongly peaked near the separatrix. Numerical equilibria are used as input for an initial value simulation which uses an extended Magnetohydrodynamic (MHD) model that includes viscous and Hall terms. Tilt stability is found for specific hollow profiles when accompanied by high values of separatrix beta, β sep . The stable profiles also have moderate to large elongation, racetrack separatrix shape, and lower values of 3, average ratio of Larmor radius to device radius. The stability is unaffected by changes in viscosity, but the neglect of the Hall term does cause stable results to become marginal or unstable. Implications for interpretation of recent experiments are discussed

Tilt stability and compression heating studies of field-reversed configurations

International Nuclear Information System (INIS)

Rej, D.J.; Tuszewski, M.; Barnes, D.C.; Barnes, G.A.; Chrien, R.E.; Siemon, R.E.; Taggart, D.P.; Webster, R.B.; Wright, B.L.; Milroy, R.D.; Crawford, E.A.; Slough, J.T.; Steinhauer, L.C.; Bailey, A.D.; Baron, M.H.; Cobb, J.W.; Staudenmeier, J.L.; Sugimoto, S.; Takahashi, T.

1990-01-01

The first observations of internal tilt instabilities in field-reversed configurations (FRCs) are reported. Detailed comparisons with theory establish that data from an array of external magnetic probes are signatures of these destructive plasma instabilities. This work reconciles theory and experiments and suggests that grossly stable FRCs are restricted to very kinetic and elongated plasmas. Self-consistent three-dimensional numerical simulations demonstrate tilt stabilization by the addition of a beam ion component. High-power compression heating experiments with stable equilibrium FRCs are also reported. Plasmas formed in a tapered theta-pinch coil have been translated along a guide magnetic field into a new single-turn compression coil where the external field is increased up to 7 times the initial value in 55 μs. Substantial heating is observed accompanied by a decrease in confinement time. 17 refs

Using collisions and resonances to tilting Uranus

Science.gov (United States)

Rogoszinski, Zeeve; Hamilton, Douglas

2018-01-01

Uranus’ large obliquity (98°) is widely thought to have occurred from a polar strike with an Earth sized object. Morbidelli et al. (2012) argue that two or more collisions are required in order to explain the prograde motion of Uranus’ satellites. These impactors could have been less massive by about a factor of ten, but multiple polar strikes are still improbable as even larger mass impactors would be needed for more equatorial collisions. Here we explore an alternative non-collisional model inspired by the explanation to Saturn’s significant tilt (27°). Ward and Hamilton (2004) & Hamilton and Ward (2004) argue that a secular resonance currently between Saturn’s spin axis and Neptune’s orbital pole is responsible for Saturn’s large obliquity. Unfortunately, Uranus’ axial precession frequency today is too long to match any of the current planets’ fundamental frequencies. Boué and Laskar (2010) explain that Uranus may have harbored an improbably large moon in the past which could have sped up the planet’s axial precession frequency enough to resonate with the regression of its own orbital pole. We explore another scenario which requires only the interactions between the giant planets.Thommes et al. (1999, 2002, 2003) argue that at least the cores of Uranus and Neptune were formed in between Jupiter and Saturn, as the density of the protoplanetary disk was greater there. If Neptune was scattered outward before Uranus, then a secular spin-orbit resonance between the two planets is possible. However, driving Uranus’ obliquity to near 90° with a resonance capture requires a timescale on the order of 100 Myr. If Neptune migrated out quicker or its orbital inclination was initially larger, then we find that the resulting resonance kick can tilt Uranus more than 40° in a reasonable timespan. This could replace one of the impactors required in the collisional scenario described by Morbidelli et al. (2012), but in most situations the effect of such a

Effect of tilting on blood pressure and interstitial fluid pressures of bluefish and smooth dogfish.

Science.gov (United States)

Ogilvy, C S; DuBois, A B

1982-01-01

Tolerance of the circulatory system of fish for gravitational stress has not been measured previously. We examined this in bluefish (Pomatomus saltatrix) and smooth dogfish (Mustelus canis) by placing them horizontally on a V-board in air while their gills were perfused with aerated seawater, then tilting them head up for 0.5 h, and finally returning them to horizontal. Meanwhile, we recorded the blood pressure, pulse pressure, and heart rate in the ventral aorta, and interstitial fluid pressure in the head and tail. All four bluefish tolerated a 30 degrees tilt or even a 60 degrees tilt with little change in blood pressure or interstitial pressure in the anterior and posterior regions. All recovered afterward. However, in the seven dogfish examined, the posterior interstitial fluid pressure increased from 2.8 +/- 1.0 cmH2O before tilting to 11.8 +/- 3.3 cmH2O toward the end of a 30 degrees tilt lasting 30 min. The blood pressure decreased as the pulse pressure approached zero, showing that circulatory insufficiency had developed due to insufficient venous return to the heart. Most of the dogfish died within a few hours after the experiment. These findings are in keeping with the conclusion that the vasculature of bluefish has more rigidity, less permeability, and perhaps more compensatory tone than that of smooth dogfish. We speculate that bluefish may have evolved their circulatory tolerance for gravity as a cross-adaptation to the stresses imposed on the circulation by forward acceleration and by regional differences of transcutaneous pressure occurring during fast carangiform swimming.

Interplay between tilted and principal axis rotation

Energy Technology Data Exchange (ETDEWEB)

Datta, Pradip [Ananda Mohan College, 102/1 Raja Rammohan Sarani, Kolkata 700 009 (India); Roy, Santosh; Chattopadhyay, S. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700 064 (India)

2014-08-14

At IUAC-INGA, our group has studied four neutron rich nuclei of mass-110 region, namely {sup 109,110}Ag and {sup 108,110}Cd. These nuclei provide the unique platform to study the interplay between Tilted and Principal axis rotation since these are moderately deformed and at the same time, shears structures are present at higher spins. The salient features of the high spin behaviors of these nuclei will be discussed which are the signatures of this interplay.

Interplay between tilted and principal axis rotation

International Nuclear Information System (INIS)

Datta, Pradip; Roy, Santosh; Chattopadhyay, S.

2014-01-01

At IUAC-INGA, our group has studied four neutron rich nuclei of mass-110 region, namely 109,110 Ag and 108,110 Cd. These nuclei provide the unique platform to study the interplay between Tilted and Principal axis rotation since these are moderately deformed and at the same time, shears structures are present at higher spins. The salient features of the high spin behaviors of these nuclei will be discussed which are the signatures of this interplay

Regional development of river basins in the Olkiluoto-Pyhaejaervi Area, SW Finland, 2000 BP - 8000 AP

International Nuclear Information System (INIS)

Ojala, A.E.K.; Virkki, H.; Palmu, J.-P.; Hokkanen, K.; Kaija, J.

2006-12-01

Biosphere assessment forms one of the main components in Posiva's Safety Case portfolio and includes analyses of terrain and ecosystem development. Shoreline displacement and changes in surface hydrology form one part of these analyses. In this report, the regional development of the Olkiluoto-Pyhaejaervi area in the time period 2000 BP - 8000 AP was examined by taking into account changes in the surface flow patterns of the Lapinjoki and Eurajoki river basins. A hydrological model, EULA, was developed and applied to investigate the past and future hydrological regimes and changes in the Olkiluoto-Pyhaejaervi study area. As detailed assessment of erosion and sedimentation effects were not within the scope of this study, only their general effects were evaluated. The digital elevation models (DEM) for different time stages (2000, 1500, 1000 and 500 BP; 100, 300, 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 6000, 7000 and 8000 AP) were compiled taking into account the land uplift and tilting of the Earth's crust. With the aid of various sophisticated GIS tools, the boundaries of the main river basins, the flow patterns of rivers and development of lakes during each stage were modelled. The yearly discharge rates of rivers Eurajoki and Lapinjoki were also evaluated with the assumption that present climatic features prevail during the whole time period 2000 BP - 8000 AP. Finally, the probability of significant changes in the surface water flow routes were estimated during different stages. (orig.)

Tilt teste no diagnóstico diferencial da "epilepsia" resistente ao tratamento Tilt table test in the differential diagnosis of refractory "epilepsy"

Directory of Open Access Journals (Sweden)

Renata Rodrigues Teixeira de Castro

2006-11-01

Full Text Available A epilepsia é uma das causas mais freqüentes de distúrbios neurológicos em adultos jovens. Relatamos um caso em que uma paciente conviveu durante doze anos com o diagnóstico de epilepsia resistente ao tratamento, quando, na verdade, a causa de seus sintomas pôde ser encontrada com a realização do teste de inclinação (tilt teste. O cardiologista deve estar alerta para o possível diagnóstico de síncope neurocardiogênica em pacientes previamente diagnosticados como portadores de epilepsia, especialmente naqueles com difícil controle terapêutico.Epilepsy is one of the most frequent causes of neurological disorders in young adults. We report the case of a patient who lived with the diagnosis of refractory epilepsy for twelve years, when actually the cause of the symptoms could be found with the performance of a tilt table test. Cardiologists should be aware of the possible diagnosis of neurocardiogenic syncope in patients previously diagnosed with epilepsy, especially in those with difficult therapeutic control.

Eddy-current testing of nuclear fuel cladding tubes using tilted encircling coil system, 1

International Nuclear Information System (INIS)

Yin, Renzhong; Sekine, Kazuyoshi; Shimizu, Hisaji; Tsukui, Kazushige; Urata, Megumu.

1989-01-01

The eddy current testing method with external encircling-coils has been widely used as a standard technique for inspection of defects in irradiated zircaloy cladding tubes. In this inspection, the systematic procedure to reliably characterize defects is required. This paper describes the newly developed external tilted encircling-coil system, in which the coil axis is inclined by an angle α to the sample tube axis, for reliable determination of the sort, location and size of defects. As the results of experimental work concerning some kinds of artificial defects in zircaloy cladding tubes using newly designed tilted coil system, an adaptable general-procedure for characterization of defects has been proposed. Furthermore, it has been confirmed that in the case of smaller tilt angles of coil, the signal-to noise ratio for defect response in this coil system is approximately equal to that of ordinary encircling coil system. (author)

Pixel-size-maintained image reconstruction of digital holograms on arbitrarily tilted planes by the angular spectrum method.

Science.gov (United States)

Jeong, Seung Jun; Hong, Chung Ki

2008-06-01

We present an effective method for the pixel-size-maintained reconstruction of images on arbitrarily tilted planes in digital holography. The method is based on the plane wave expansion of the diffraction wave fields and the three-axis rotation of the wave vectors. The images on the tilted planes are reconstructed without loss of the frequency contents of the hologram and have the same pixel sizes. Our method shows good results in the extreme cases of large tilting angles and in the region closer than the paraxial case. The effectiveness of the method is demonstrated by both simulation and experiment.

Tip-tilt disturbance model identification based on non-linear least squares fitting for Linear Quadratic Gaussian control

Science.gov (United States)

Yang, Kangjian; Yang, Ping; Wang, Shuai; Dong, Lizhi; Xu, Bing

2018-05-01

We propose a method to identify tip-tilt disturbance model for Linear Quadratic Gaussian control. This identification method based on Levenberg-Marquardt method conducts with a little prior information and no auxiliary system and it is convenient to identify the tip-tilt disturbance model on-line for real-time control. This identification method makes it easy that Linear Quadratic Gaussian control runs efficiently in different adaptive optics systems for vibration mitigation. The validity of the Linear Quadratic Gaussian control associated with this tip-tilt disturbance model identification method is verified by experimental data, which is conducted in replay mode by simulation.

Disk Disruptions and X-ray Intensity Excursions in Cyg X-2, LMC X-3 and Cyg X-3

Science.gov (United States)

Boyd, P. T.; Smale, A. P.

2001-05-01

The RXTE All Sky Monitor soft X-ray light curves of many X-ray binaries show long-term intensity variations (a.k.a "superorbital periodicities") that have been ascribed to precession of a warped, tilted accretion disk around the X-ray source. We have found that the excursion times between X-ray minima in Cyg X-2 can be characterized as a series of integer multiples of the 9.8 binary orbital period, (as opposed to the previously reported stable 77.7 day single periodicity, or a single modulation whose period changes slowly with time). While the data set is too short for a proper statistical analysis, it is clear that the length of any given intensity excursion cannot be used to predict the next (integer) excursion length in the series. In the black hole candidate system LMC X-3, the excursion times are shown to be related to each other by rational fractions. We find that the long term light curve of the unusual galactic X-ray jet source Cyg X-3 can also be described as a series of intensity excursions related to each other by integer multiples of a fundamental underlying clock. In the latter cases, the clock is apparently not related to the known binary periods. A unified physical model, involving both an inclined accretion disk and a fixed-probability disk disruption mechanism is presented, and compared with three-body scattering results. Each time the disk passes through the orbital plane it experiences a fixed probability P that it will disrupt. This model has testable predictions---the distribution of integers should resemble that of an atomic process with a characteristic half life. Further analysis can support or refute the model, and shed light on what system parameters effectively set the value of P.

Diagnostic accuracy of state-of-the-art MDCT scanners without gantry tilt in patients with oral and oropharyngeal cancer

International Nuclear Information System (INIS)

Bannas, Peter; Habermann, Christian R.; Jung, Caroline; Bley, Thorsten A.; Ittrich, Harald; Adam, Gerhard; Koops, Andreas

2012-01-01

Purpose: Current CT-protocols for staging oral and oropharyngeal cancer include primary transversal slices and secondary tilted slices to avoid artifact-producing regions of dental metalwork. Some of the latest MDCT scanners do not allow gantry tilt. Hence, we assessed the relevance of secondary tilted slices in tumor staging. Materials and methods: Scans of a tiltable 64-row MDCT-scanner of 82 patients with oral or oropharyngeal cancer were retrospectively and independently evaluated twice by three readers: once using the primary transversal scans only, and once taking the transversal and secondary tilted scans into account. Tumor diameters and TN-stage were determined with both methods. Artifacts on transversal scans were analyzed using a 3-point-ranking-scale. Results: Image quality was impaired by severe artifacts in 24% of transversal slices of the oral cavity and in 12% of the oropharynx. The three readers detected an average of 57.7 ± 2.1 of 82 tumors (70%) on transversal CT slices. An average of 6.3 ± 0.6 more tumors (8%) were detected when transversal studies were evaluated in conjunction with secondary tilted slices, leading to a significantly (p = 0.0156–0.0313) increased average detection rate of 64.0 ± 2.0 tumors (78%). Moreover, secondary tilted slices led to a correction of underestimated tumor stages in up to six patients (7.3%). Conclusion: Tilted slices that avoid artifact-producing regions of dental metalwork significantly improve the reader's sensitivity and are of incremental value for staging of oral and oropharyngeal cancers.

Bound Chains of Tilted Dipoles in Layered Systems

DEFF Research Database (Denmark)

G. Volosniev, A.; R. Armstrong, J.; V. Fedorov, D.

2012-01-01

of an external eletric field. The binding energy and the spatial structure of the bound states are studied in several different ways using analytical approaches. The results are compared to stochastic variational calculations and very good agreement is found. We conclude that approximations based on harmonic...... oscillator potentials are accurate even for tilted dipoles when the geometry of the potential landscape is taken into account....

A pathway in the brainstem for roll-tilt of the subjective visual vertical: evidence from a lesion-behavior mapping study.

Science.gov (United States)

Baier, Bernhard; Thömke, Frank; Wilting, Janine; Heinze, Caroline; Geber, Christian; Dieterich, Marianne

2012-10-24

The perceived subjective visual vertical (SVV) is an important sign of a vestibular otolith tone imbalance in the roll plane. Previous studies suggested that unilateral pontomedullary brainstem lesions cause ipsiversive roll-tilt of SVV, whereas pontomesencephalic lesions cause contraversive roll-tilts of SVV. However, previous data were of limited quality and lacked a statistical approach. We therefore tested roll-tilt of the SVV in 79 human patients with acute unilateral brainstem lesions due to stroke by applying modern statistical lesion-behavior mapping analysis. Roll-tilt of the SVV was verified to be a brainstem sign, and for the first time it was confirmed statistically that lesions of the medial longitudinal fasciculus (MLF) and the medial vestibular nucleus are associated with ipsiversive tilt of the SVV, whereas contraversive tilts are associated with lesions affecting the rostral interstitial nucleus of the MLF, the superior cerebellar peduncle, the oculomotor nucleus, and the interstitial nucleus of Cajal. Thus, these structures constitute the anatomical pathway in the brainstem for verticality perception. Present data indicate that graviceptive otolith signals present a predominant role in the multisensory system of verticality perception.

Low-Frequency Otolith Function in Microgravity: A Re-Evaluation of the Otolith Tilt-Translation Reinterpretation (OTTR) Hypothesis

Science.gov (United States)

Moore, Steven T.; Cohen, Bernard; Clement, Gilles; Raphan, Theodore

1999-01-01

On Earth, the low-frequency afferent signal from the otoliths encodes head tilt with respect to the gravitational vertical, and the higher frequency components reflect both tilt and linear acceleration of the head. In microgravity, static tilt of the head does not influence otolith output, and the relationship between sensory input from the vestibular organs, and the visual, proprioceptive and somatosensory systems, would be disrupted. Several researchers have proposed that in 0-g this conflict may induce a reinterpretation of all otolith signals by the brain to encode only linear translation (otolith tilt-translation reinterpretation or OTTR). Ocular counter-rolling (OCR) is a low-frequency otolith-mediated reflex, which generates compensatory torsional eye movements (rotation about the visual axis) towards the spatial vertical during static roll tilt with a gain of approximately 10%. Transient linear acceleration and off-axis centrifugation at a constant angular velocity can also generate OCR. According to the OTTR hypothesis, OCR should be reduced in microgravity, and immediately upon return from a 0-g environment. Results to date have been inconclusive. OCR was reduced following the 10 day Spacelab-1 mission in response to leftward roll tilts (28-56% in 3 subjects and unchanged in one subject), and sinusoidal linear oscillations at 0.4 and 0.8 Hz. OCR gain declined 70% in four monkeys following a 14 day COSMOS mission. Following a 30 day MIR mission OCR gain decreased in one astronaut, but increased in two others following a 180 day mission. We have studied the affect of microgravity on low-frequency otolith function as part of a larger study of the interaction of vision and the vestibular system. This experiment (E-047) involved off-axis centrifugation of payload crewmembers and flew aboard the recent Neurolab mission (STS 90). Presented below are preliminary results focusing on perception and the OCR response during both centrifugation and static tilt.

Constriction of collateral arteries induced by "head-up tilt" in patients with occlusive arterial disease of the legs

DEFF Research Database (Denmark)

Agerskov, K; Henriksen, O; Tønnesen, K H

1981-01-01

The effect of head-up tilt on leg blood flow and segmental arterial blood pressures was studied in 21 patients with occlusion or severe stenosis of the common or superficial femoral artery. Arterial pressure was measured directly in the brachial artery, common femoral artery and popliteal artery....... Relative change in blood flow in the leg during tilt was estimated by changes in arterio-venous oxygen differences and by the indicator dilution technique in nine patients. Head-up tilt caused a decrease in leg blood flow of 36% corresponding to an increase in total vascular resistance of 57%. Tilt did...... not change the pressure gradient from femoral to popliteal artery in the patients with occlusion of the superficial femoral artery, indicating that the flow resistance offered by the collateral arteries had increased. In a bilateral sympathectomised patient the increase in collateral resistance was almost...

Reconstruction of Stress and Composition Profiles from X-ray Diffraction Experiments - How to Avoid Ghost Stresses?

DEFF Research Database (Denmark)

Christiansen, Thomas; Somers, Marcel A.J.

2004-01-01

On evaluating lattice strain-depth or stress-depth profiles with X-ray diffraction, the variation of the information depth while combining various tilt angles,psi, in combination with lattice spacing gradients leads to artefacts,so-called ghost or fictitious stresses. X-ray diffraction lattice...... method for the evaluation of stress/strain and composition profiles, while minimising the risk for ghost stresses....

Morphological classification of acromial spur: correlation between Rockwood tilt view and arthroscopic finding

Directory of Open Access Journals (Sweden)

Kongmalai Pinkawas

2017-01-01

Full Text Available Purpose and hypothesis: Acromion spur is the extrinsic factor for impingement syndrome and rotator cuff tear. The Rockwood tilt view can be used to evaluate prominence of the anterior acromion, however no study has shown the correlation of findings between the Rockwood tilt view and the arthroscopic finding. Methods: We developed the arthroscopic classification of acromion spur as type 1 flat spur, type 2 bump spur, type 3 heel spur, type 4 keel spur, and type 5 irregular spur. Patients with rotator cuff syndrome who underwent arthroscopic surgery were recruited. Two observers were asked to classify the type of spur from arthroscopic findings and Rockwood tilt views separately in random pattern. The prevalence of supraspinatus tendon tear was also recorded as no tear, partial-thickness tear, and full-thickness tear. Results: The keel spur (33.9% was the most common finding followed by the heel spur (27.8%. The correlation was high especially for the heel, the keel, and the irregular spur (75.47%, 74.03%, and 72.73%, respectively. These three types of spurs have a high prevalence of full thickness of supraspinatus tendon tear. Conclusion: The Rockwood tilt view can be used to evaluate the morphology of an acromion spur, especially the at-risk spur that correlates highly with the full-thickness supraspinatus tendon tear. The arthroscopic classification will also be a useful tool to improve communication between the surgeon and the guide for appropriate treatment in a rotator cuff tear patient when encountering the heel, keel, and irregular spur.

Effect of Cement and Compaction on the Physicochemical Behavior of a Material in the Region of Sidi Bel Abbes

Directory of Open Access Journals (Sweden)

N. S. Ikhlef

2014-08-01

Full Text Available Soil treatment describes the procedure under which a soil acquires certain characteristics that did not originally have. This paper is focused in the field of road earthworks and the treatment of a material found in the region of Sidi Bel Abbes, Algeria. This material has poor characteristics that do not meet the standards used in road geotechnics. To remedy this, firstly, the Proctor Standard characteristics of this material were improved using mechanical treatment that increased the compaction energy. Then a chemical treatment was employed, adding some cement dosages, and results show that the material classified in the A1h class, for an increased maximum dry density and a reduction in water content. A comparative study is made on the optimal properties of the material between the two modes of treatment. On the other hand, after treatment, one finds a decrease in the plasticity index and the methylene blue value. This material exhibits a change of class. Therefore, soil class CL turned into a soil class CL-ML (silt of low plasticity. This observation allows the material to be used as backfill or subgrade.

[Renin-angiotensin-aldosterone system activity during head-up tilt testing in patients with vasovagal syncope].

Science.gov (United States)

Gajek, Jacek; Zyśko, Dorota; Mazurek, Walentyna

2005-08-01

The stimulation of renin-angiotensin-aldosterone (RAA) system during tilt table test is caused by sympathetic nervous system activation by orthostatic stress and a serotonin release as well. In healthy individuals increase of plasma renin activity during test with maximal values on the peak of the test was described. The aim of the study was to assess the activation of RAAS in patients with neurally mediated syncope during the tilt table test by means of plasma renin activity and serum aldosterone levels. The study was carried out in 31 patients aged 39.4 +/- 15.0 years (18 women and 13 men) with neurally mediated syncope during tilt test. Plasma renin activity was assessed in the baseline conditions, immediately after the test and 10 minutes after the test using radioenzymatic assay. Aldosterone concentrations were measured radioimmunologically, twice: after 30 minutes supine rest and after the syncope. Plasma renin activity during supine rest was 2.2 +/- 2.4 ng/ml/h, rose after the syncope 2.5-fold to 5.2 +/- 4.5 ng/ml/h (p < 0.001 comparing to baseline) stayed on similar level approximately for the next 10 minutes--4.9 +/- 5.5 ng/ml/h (p = n.s.). In 11 patients (35%) 10 minutes after the test even further increase of PRA was observed. Serum aldosterone level increased significantly immediately after tilt test (90.0 +/- 72.9 vs 178.8 +/- 150.1 pg/ml, p < 0.01). Authors showed, that in patients with NMS plasma renin activity increases and this increase lasts for 10 minutes after the syncope and the concentration of aldosterone increases immediately after tilt test.

Hamstring muscle length and pelvic tilt range among individuals with and without low back pain.

Science.gov (United States)

Fasuyi, Francis Oluwafunsho; Fabunmi, Ayodele A; Adegoke, Babatunde O A

2017-04-01

Hamstring tightness has been documented not to be related to the pelvic tilt position during static standing posture, but there is limited data on the relationship between hamstring muscle length (HML) and pelvic tilt range (PTR) during the dynamic movement of forward bending. This ex-post facto study was designed to compare each of HML and PTR in individuals with low back pain (LBP) and counterparts without LBP, and the relationship between HML and PTR in individuals with and without LBP. The study involved 30 purposively recruited individuals with LBP and 30 height and weight-matched individuals without LBP. Participants' PTR and HML were assessed using digital inclinometer and active knee extension test respectively. Data were analyzed using t-test and Pearson Correlation (r) at α = 0.05. Participants without LBP had significantly longer (p = 0.01) HML than those with LBP but the PTR of both groups were not significantly different. HML and PTR had indirect but not significant correlations in participants with and without LBP. Hamstring muscle length is significantly reduced in individuals with LBP but it has no significant correlation with pelvic tilt range. Pelvic tilt range reduces as hamstring muscle length increases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tilted Light Sheet Microscopy with 3D Point Spread Functions for Single-Molecule Super-Resolution Imaging in Mammalian Cells.

Science.gov (United States)

Gustavsson, Anna-Karin; Petrov, Petar N; Lee, Maurice Y; Shechtman, Yoav; Moerner, W E

2018-02-01

To obtain a complete picture of subcellular nanostructures, cells must be imaged with high resolution in all three dimensions (3D). Here, we present tilted light sheet microscopy with 3D point spread functions (TILT3D), an imaging platform that combines a novel, tilted light sheet illumination strategy with engineered long axial range point spread functions (PSFs) for low-background, 3D super localization of single molecules as well as 3D super-resolution imaging in thick cells. TILT3D is built upon a standard inverted microscope and has minimal custom parts. The axial positions of the single molecules are encoded in the shape of the PSF rather than in the position or thickness of the light sheet, and the light sheet can therefore be formed using simple optics. The result is flexible and user-friendly 3D super-resolution imaging with tens of nm localization precision throughout thick mammalian cells. We validated TILT3D for 3D super-resolution imaging in mammalian cells by imaging mitochondria and the full nuclear lamina using the double-helix PSF for single-molecule detection and the recently developed Tetrapod PSF for fiducial bead tracking and live axial drift correction. We envision TILT3D to become an important tool not only for 3D super-resolution imaging, but also for live whole-cell single-particle and single-molecule tracking.

Tilted light sheet microscopy with 3D point spread functions for single-molecule super-resolution imaging in mammalian cells

Science.gov (United States)

Gustavsson, Anna-Karin; Petrov, Petar N.; Lee, Maurice Y.; Shechtman, Yoav; Moerner, W. E.

2018-02-01

To obtain a complete picture of subcellular nanostructures, cells must be imaged with high resolution in all three dimensions (3D). Here, we present tilted light sheet microscopy with 3D point spread functions (TILT3D), an imaging platform that combines a novel, tilted light sheet illumination strategy with engineered long axial range point spread functions (PSFs) for low-background, 3D super localization of single molecules as well as 3D super-resolution imaging in thick cells. TILT3D is built upon a standard inverted microscope and has minimal custom parts. The axial positions of the single molecules are encoded in the shape of the PSF rather than in the position or thickness of the light sheet, and the light sheet can therefore be formed using simple optics. The result is flexible and user-friendly 3D super-resolution imaging with tens of nm localization precision throughout thick mammalian cells. We validated TILT3D for 3D superresolution imaging in mammalian cells by imaging mitochondria and the full nuclear lamina using the double-helix PSF for single-molecule detection and the recently developed Tetrapod PSF for fiducial bead tracking and live axial drift correction. We envision TILT3D to become an important tool not only for 3D super-resolution imaging, but also for live whole-cell single-particle and single-molecule tracking.

Improvement of image quality of holographic projection on tilted plane using iterative algorithm

Science.gov (United States)

Pang, Hui; Cao, Axiu; Wang, Jiazhou; Zhang, Man; Deng, Qiling

2017-12-01

Holographic image projection on tilted plane has an important application prospect. In this paper, we propose a method to compute the phase-only hologram that can reconstruct a clear image on tilted plane. By adding a constant phase to the target image of the inclined plane, the corresponding light field distribution on the plane that is parallel to the hologram plane is derived through the titled diffraction calculation. Then the phase distribution of the hologram is obtained by the iterative algorithm with amplitude and phase constrain. Simulation and optical experiment are performed to show the effectiveness of the proposed method.

Transverse Seebeck and Peltier effect in tilted metal-semiconductor multilayer structures

International Nuclear Information System (INIS)

Reitmaier, Christina

2012-01-01

Whether in aerospace, automobile industry or in home appliances, thermoelectric effects find use in many areas of technology. This work deals with the investigation of a special form of these effects, the transversal Seebeck- and Peltier effect. Via modelling under variation of the sample parameters the cooling efficiencies, the attainable temperature differences and the Figures of merit are optimised and than suitable samples are produced according to these specifications. With these tilted metal semiconductor multilayer structures consisting of lead and bismuth telluride a transversal Peltier effect is observed. Moreover, the generation of electric power is examined via the transversal Seebeck effect. In tilted Pb-Bi2Te3 multilayers the efficiency is measured with the conversion by heat in electric power and is compared to model calculations. (orig.)

On the simplifications for the thermal modeling of tilting-pad journal bearings under thermoelastohydrodynamic regime

DEFF Research Database (Denmark)

Cerda Varela, Alejandro Javier; Fillon, Michel; Santos, Ilmar

2012-01-01

formulation for inclusion of the heat transfer effects between oil film and pad surface. Such simplified approach becomes necessary when modeling the behavior of tilting-pad journal bearings operating on controllable lubrication regime. Three different simplified heat transfer models are tested, by comparing...... are strongly dependent on the Reynolds number for the oil flow in the bearing. For bearings operating in laminar regime, the decoupling of the oil film energy equation solving procedure, with no heat transfer terms included, with the pad heat conduction problem, where the oil film temperature is applied......The relevance of calculating accurately the oil film temperature build up when modeling tilting-pad journal bearings is well established within the literature on the subject. This work studies the feasibility of using a thermal model for the tilting-pad journal bearing which includes a simplified...

A note on tilted Bianchi type VIh models: the type III bifurcation

Science.gov (United States)

Coley, A. A.; Hervik, S.

2008-10-01

In this note we complete the analysis of Hervik, van den Hoogen, Lim and Coley (2007 Class. Quantum Grav. 24 3859) of the late-time behaviour of tilted perfect fluid Bianchi type III models. We consider models with dust, and perfect fluids stiffer than dust, and eludicate the late-time behaviour by studying the centre manifold which dominates the behaviour of the model at late times. In the dust case, this centre manifold is three-dimensional and can be considered a double bifurcation as the two parameters (h and γ) of the type VIh model are varied. We therefore complete the analysis of the late-time behaviour of tilted ever-expanding Bianchi models of types I VIII.

Surface tension-induced PDMS micro-pillars with controllable tips and tilt angles

KAUST Repository

Li, Huawei; Fan, Yiqiang; Conchouso Gonzalez, David; Foulds, Ian G.

2013-01-01

This paper reports a novel method to fabricate three-dimensional (3D) polydimethylsiloxane (PDMS) micro-pillars using a CO2 laser-machined poly(methyl methacrylate) (PMMA) mold with through-holes. This method eliminates the requirements of expensive and complicated facilities to fabricate a 3D mold. The micro-pillars were formed by the capillary force that draws PDMS into the through-holes of the PMMA mold. The tilt angles of the micro-pillars depend on the tilt angles of the through-holes in the mold, and the concave and convex micro-lens tip shapes of the PDMS micro-pillars can be modified by changing the surface wettability of the PMMA through-holes.

Surface tension-induced PDMS micro-pillars with controllable tips and tilt angles

KAUST Repository

Li, Huawei

2013-12-21

This paper reports a novel method to fabricate three-dimensional (3D) polydimethylsiloxane (PDMS) micro-pillars using a CO2 laser-machined poly(methyl methacrylate) (PMMA) mold with through-holes. This method eliminates the requirements of expensive and complicated facilities to fabricate a 3D mold. The micro-pillars were formed by the capillary force that draws PDMS into the through-holes of the PMMA mold. The tilt angles of the micro-pillars depend on the tilt angles of the through-holes in the mold, and the concave and convex micro-lens tip shapes of the PDMS micro-pillars can be modified by changing the surface wettability of the PMMA through-holes.

Fault diagnosis for tilting-pad journal bearing based on SVD and LMD

Directory of Open Access Journals (Sweden)

Zhang Xiaotao

2016-01-01

Full Text Available Aiming at fault diagnosis for tilting-pad journal bearing with fluid support developed recently, a new method based on singular value decomposition (SVD and local mean decomposition (LMD is proposed. First, the phase space reconstruction of Hankel matrix and SVD method are used as pre-filter process unit to reduce the random noises in the original signal. Then the purified signal is decomposed by LMD into a series of production functions (PFs. Based on PFs, time frequency map and marginal spectrum can be obtained for fault diagnosis. Finally, this method is applied to numerical simulation and practical experiment data. The results show that the proposed method can effectively detect fault features of tilting-pad journal bearing.

More Falls in Cerebellar Ataxia When Standing on a Slow Up-Moving Tilt of the Support Surface.

Science.gov (United States)

Paquette, Caroline; Franzén, Erika; Horak, Fay B

2016-06-01

We investigated how subjects with cerebellar ataxia (CA) adapt their postural stability and alignment to a slow and small tilt of the support surface allowing for online postural corrections. Eight subjects with CA and eight age- and gender-matched healthy control subjects participated in the study. Subjects stood eyes closed for 1 min after which the support surface was tilted 5° toes-up at a ramp velocity of 1°/s. The toes-up position was held for 2.5 min after which the surface rotated back down to level with identical tilt characteristics. As reflected by the large number of falls, subjects with CA had marked difficulty adapting their posture to the up-moving incline in contrast to control subjects. Subjects with CA who lost their balance had faster trunk velocity and excessive backward trunk reorientation beginning within the first second after onset of the tilting surface. In contrast, the down-moving tilt to level did not result in instability in CA subjects. These results suggest that instability and falls associated with CA derive from an inability to maintain trunk orientation to vertical while standing on a slow-moving or unstable surface. This study underscores the importance of the cerebellum in the online sensory control of the upper body orientation during small amplitude and slow velocity movements of the support surface.

An Analysis of Source Tilting and Sub-cell Opacity Sampling for IMC

Energy Technology Data Exchange (ETDEWEB)

Wollaeger, Ryan T. [Los Alamos National Laboratory; Urbatsch, Todd J. [Los Alamos National Laboratory; Wollaber, Allan B. [Los Alamos National Laboratory; Densmore, Jeffery D. [Los Alamos National Laboratory

2012-08-02

Implicit Monte Carlo (IMC) is a stochastic method for solving the radiative transfer equations for multiphysics application with the material in local thermodynamic equilibrium. The IMC method employs a fictitious scattering term that is computed from an implicit discretization of the material temperature equation. Unfortunately, the original histogram representation of the temperature and opacity with respect to the spatial domain leads to nonphysically fast propagation of radiation waves through optically thick material. In the past, heuristic source tilting schemes have been used to mitigate the numerical teleportation error of the radiation particles in IMC that cause this overly rapid radiation wave propagation. While improving the material temperature profile throughout the time duration, these tilting schemes alone do not generally alleviate the teleportation error to suitable levels. Another means of potentially reducing teleportation error in IMC is implementing continuous sub-cell opacities based on sub-cell temperature profiles. We present here an analysis of source tilting and continuous sub-cell opacity sampling applied to various discretizations of the temperature equation. Through this analysis, we demonstrate that applying both heuristics does not necessarily yield more accurate results if the discretization of the material equation is inconsistent with the Monte Carlo sub-cell transport.

Distinctive Steady-State Heart Rate and Blood Pressure Responses to Passive Robotic Leg Exercise and Functional Electrical Stimulation during Head-Up Tilt.

Science.gov (United States)

Sarabadani Tafreshi, Amirehsan; Riener, Robert; Klamroth-Marganska, Verena

2016-01-01

Introduction: Tilt tables enable early mobilization of patients by providing verticalization. But there is a high risk of orthostatic hypotension provoked by verticalization, especially after neurological diseases such as spinal cord injury. Robot-assisted tilt tables might be an alternative as they add passive robotic leg exercise (PE) that can be enhanced with functional electrical stimulation (FES) to the verticalization, thus reducing the risk of orthostatic hypotension. We hypothesized that the influence of PE on the cardiovascular system during verticalization (i.e., head-up tilt) depends on the verticalization angle, and FES strengthens the PE influence. To test our hypotheses, we investigated the PE effects on the cardiovascular parameters heart rate (HR), and systolic and diastolic blood pressures (sBP, dBP) at different angles of verticalization in a healthy population. Methods: Ten healthy subjects on a robot-assisted tilt table underwent four different study protocols while HR, sBP, and dBP were measured: (1) head-up tilt to 60° and 71° without PE; (2) PE at 20°, 40°, and 60° of head-up tilt; (3) PE while constant FES intensity was applied to the leg muscles, at 20°, 40°, and 60° of head-up tilt; (4) PE with variation of the applied FES intensity at 0°, 20°, 40°, and 60° of head-up tilt. Linear mixed models were used to model changes in HR, sBP, and dBP responses. Results: The models show that: (1) head-up tilt alone resulted in statistically significant increases in HR and dBP, but no change in sBP. (2) PE during head-up tilt resulted in statistically significant changes in HR, sBP, and dBP, but not at each angle and not always in the same direction (i.e., increase or decrease of cardiovascular parameters). Neither adding (3) FES at constant intensity to PE nor (4) variation of FES intensity during PE had any statistically significant effects on the cardiovascular parameters. Conclusion: The effect of PE on the cardiovascular system during

The effect of seated pelvic tilt on posterior edge-loading in total hip arthroplasty: A finite element investigation.

Science.gov (United States)

Pierrepont, Jim; Yang, Long; Arulampalam, Jevan; Stambouzou, Catherine; Miles, Brad; Li, Qing

2018-03-01

Edge-loading of a ceramic-on-ceramic total hip replacement can lead to reproducible squeaking and revision. A patient's functional acetabular cup orientation, driven by their pelvic tilt, has been shown to be a significant factor in squeaking during hip flexion. The aim of this study was to investigate the effect of seated pelvic tilt on the contact mechanics at the ceramic bearing surface. A finite element model of a ceramic-on-ceramic total hip replacement was created. The cup was orientated at 40° inclination and 15° anteversion relative to the anterior pelvic plane. The stem was flexed 90° to replicate sitting in a chair. The model was loaded using data from in vivo measurements taken during a sit-to-stand activity. The pelvis was modelled in seven different sagittal positions, ranging from -30° to 30° of pelvic tilt, where a positive value denotes anterior pelvic tilt. Three different head sizes were investigated: 32, 36 and 40 mm. The maximum contact pressure and contact patch to rim distance were determined for each of the 21 simulations. Edge-loading (contact patch to rim distance Edge-loading initiated at seated pelvic tilts of 7°, 9° and 5° for the 32, 36 and 40 mm heads, respectively. Patients with anterior pelvic tilts in the seated position are susceptible to posterior edge-loading. As the position of the pelvis when seated is patient specific, cup orientation should be adjusted on an individual basis to minimise edge-loading.

Performance of a Tilt Current Meter in the Surf Zone

DEFF Research Database (Denmark)

Hansen, Asger Bendix; Carstensen, Stefan; Christensen, Drude Fritzbøger

2017-01-01

Tilt Current Meters (TCM’s) are relatively simple and inexpensive instruments for measuring currents in rivers and inthe sea. Their low cost and easy deployment means that a relatively large number of TCM’s can be deployed comparedto more conventional current meters such as Acoustic Doppler...

Morphology, structure, and electrical properties of YBa2Cu3Ox thin films on tilted NdGaO3 substrates, deposited by DC-sputtering

International Nuclear Information System (INIS)

Mozhaev, Peter B.; Kotelyanskii, Iosif M.; Luzanov, Valery A.; Mozhaeva, Julia E.; Donchev, Todor; Mateev, Emil; Nurgaliev, Timur; Bdikin, Igor K.; Narymbetov, Bakhyt Zh.

2005-01-01

Thin YBa 2 Cu 3 O x (YBCO) films were deposited using DC-sputtering technique on NdGaO 3 substrates, tilted from (1 1 0) orientation by 0-26 deg . The structure and surface quality of the substrates were carefully characterized to obtain reliable results of thin films deposition. Structural, morphological and electrical properties of the YBCO thin films show three different ranges of inclination angle: vicinal, intermediate and high. In the vicinal range the properties of the film are generally the same as of the standard films deposited on (1 1 0) NdGaO 3 substrate. An increase of the inclination angle to the intermediate range results in a significant improvement of morphology and structural quality of the film. Best electrical parameters are measured for the films of the intermediate range also. Probable reason for such behavior is simultaneous and regular seeding of the film in the joints of facets on the substrate surface. Further increase of inclination angle leads to step bunching and oxygen out-diffusion, destroying both structural and electrical perfection of the tilted-axes YBCO film

Nonlinear Dynamics Analysis of Tilting Pad Journal Bearing-Rotor System

Directory of Open Access Journals (Sweden)

Jiayang Ying

2011-01-01

Full Text Available The nonlinear dynamics theory is increasingly applied in the dynamics analysis of tilting pad journal bearing-rotor system. However, extensive work on system dynamics done previously neglects the influence caused by the moment of inertia of the pad. In this paper, a comparison is made between the responses of the rotor in the bearings with and without pad inertia effect. Taking the Jeffcott rotor system as an example, the characteristics of bearing-rotor system, such as bifurcation diagram, cycle response, frequency spectrum, phase trajectories, and Poincaré maps, were attained within a certain rotation rate range. The pivotal oil-film force of tilting pad journal bearing was calculated by database method. The results directly demonstrate that considering the influence of the pad moment of inertia, system dynamics characteristics are found more complicated when rotor-bearing system works around natural frequency and system bifurcation is observed forward when rotor-bearing system works on high-speed range.

The repeatability of left ventricular volume assessment by a new ambulatory radionuclide monitoring system during head-up tilt

International Nuclear Information System (INIS)

Takase, Bonpei; Hosaka, Haruhiko; Kitamura, Katsuhiro

2001-01-01

The precise measurement of changes in left ventricular volume is important to elucidate the mechanisms of neurally mediated syncope. This study was conducted to determine whether or not a brand-new ambulatory radionuclide monitoring system (C-VEST system) can be clinically used to easily and precisely measure left ventricular volume and function in tilt testing. To assess the repeatability of the C-VEST system, 12 healthy volunteers (mean age 24±4 years old) underwent 20 minute head-up tilt testing and we measured the temporal changes in left ventricular volume and ejection fraction twice a day (first and second studies). To investigate the changes in the C-VEST measurements and the detector position in the first and second studies, tilt testing was performed with an 80-degree passive tilt, which is the same as the standard procedure used in diagnosing neurally mediated syncope. The coefficient of repeatability for both the C-VEST and detector position was well within the clinical range (coefficient of repeatability in left ventricular volume ranged from 1.7 to 2.8; coefficient of repeatability in the detector position ranged from 2.3 to 3.1). Precise evaluation of the left ventricular volume can be achieved by an ambulatory radionuclide monitoring system in tilt testing. (author)

The impact of office chair features on lumbar lordosis, intervertebral joint and sacral tilt angles: a radiographic assessment.

Science.gov (United States)

De Carvalho, Diana; Grondin, Diane; Callaghan, Jack

2017-10-01

The purpose of this study was to determine which office chair feature is better at improving spine posture in sitting. Participants (n = 28) were radiographed in standing, maximum flexion and seated in four chair conditions: control, lumbar support, seat pan tilt and backrest with scapular relief. Measures of lumbar lordosis, intervertebral joint angles and sacral tilt were compared between conditions and sex. Sitting consisted of approximately 70% of maximum range of spine flexion. No differences in lumbar flexion were found between the chair features or control. Significantly more anterior pelvic rotation was found with the lumbar support (p = 0.0028) and seat pan tilt (p < 0.0001). Males had significantly more anterior pelvic rotation and extended intervertebral joint angles through L1-L3 in all conditions (p < 0.0001). No one feature was statistically superior with respect to minimising spine flexion, however, seat pan tilt resulted in significantly improved pelvic posture. Practitioner Summary: Seat pan tilt, and to some extent lumbar supports, appear to improve seated postures. However, sitting, regardless of chair features used, still involves near end range flexion of the spine. This will increase stresses to the spine and could be a potential injury generator during prolonged seated exposures.

Effects of head down tilt on episcleral venous pressure in a rabbit model.

Science.gov (United States)

Lavery, W J; Kiel, J W

2013-06-01

In humans, changing from upright to supine elicits an approximately 10 mmHg increase in cephalic venous pressure caused by the hydrostatic column effect, but episcleral venous pressure (EVP) and intraocular pressure (IOP) rise by only a few mmHg. The dissociation of the small increases in IOP and EVP compared to the larger increase in cephalic venous pressure suggests a regulatory mechanism controlling EVP. The aim of the present study was to determine if the rabbit model is suitable to study the effects of postural changes on EVP despite its short hydrostatic column. In anesthetized rabbits (n = 43), we measured arterial pressure (AP), IOP, and orbital venous pressure (OVP) by direct cannulation; carotid blood flow (BFcar) by transit time ultrasound, heart rate (HR) by digital cardiotachometer, and EVP with a servonull micropressure system. The goal of the protocol was to obtain measurement of supine EVP for ≈10 min, followed by ≈10 min of EVP measurement with the rabbit in a head down tilt. The data were analyzed by paired t-tests and the results reported as the mean ± standard error of the mean. In a separate group of animals (n = 35), aqueous flow was measured by fluorophotometry. This protocol entailed measurement of aqueous flow in the supine position for ≈60 min, followed by ≈60 min of aqueous flow measurement with the rabbit in a head down tilt. From supine to head down tilt, AP and BFcar were unchanged, IOP increased by 2.3 ± 0.4 mmHg (p measurements of the pressures and systemic parameters likely involved in the EVP responses to posture change. The present results indicate directionally similar EVP and IOP responses to tilt as occur in humans and, as in humans, the responses are smaller than would be expected from the change in the hydrostatic column height. Also, as in humans, the model reveals no change in aqueous flow during head down tilt. We conclude the rabbit model is appropriate for studying the mechanisms responsible for the relative

Remote sensing of a NTC radio source from a Cluster tilted spacecraft pair

Directory of Open Access Journals (Sweden)

P. M. E. Décréau

2013-11-01

Full Text Available The Cluster mission operated a "tilt campaign" during the month of May 2008. Two of the four identical Cluster spacecraft were placed at a close distance (~50 km from each other and the spin axis of one of the spacecraft pair was tilted by an angle of ~46°. This gave the opportunity, for the first time in space, to measure global characteristics of AC electric field, at the sensitivity available with long boom (88 m antennas, simultaneously from the specific configuration of the tilted pair of satellites and from the available base of three satellites placed at a large characteristic separation (~1 RE. This paper describes how global characteristics of radio waves, in this case the configuration of the electric field polarization ellipse in 3-D-space, are identified from in situ measurements of spin modulation features by the tilted pair, validating a novel experimental concept. In the event selected for analysis, non-thermal continuum (NTC waves in the 15–25 kHz frequency range are observed from the Cluster constellation placed above the polar cap. The observed intensity variations with spin angle are those of plane waves, with an electric field polarization close to circular, at an ellipticity ratio e = 0.87. We derive the source position in 3-D by two different methods. The first one uses ray path orientation (measured by the tilted pair combined with spectral signature of magnetic field magnitude at source. The second one is obtained via triangulation from the three spacecraft baseline, using estimation of directivity angles under assumption of circular polarization. The two results are not compatible, placing sources widely apart. We present a general study of the level of systematic errors due to the assumption of circular polarization, linked to the second approach, and show how this approach can lead to poor triangulation and wrong source positioning. The estimation derived from the first method places the NTC source region in the

Design and initial characterization of a compact, ultra high vacuum compatible, low frequency, tilt accelerometer

International Nuclear Information System (INIS)

O’Toole, A.; Peña Arellano, F. E.; Rodionov, A. V.; Kim, C.; Shaner, M.; Asadoor, M.; Sobacchi, E.; Dergachev, V.; DeSalvo, R.; Bhawal, A.; Gong, P.; Lottarini, A.; Minenkov, Y.; Murphy, C.

2014-01-01

A compact tilt accelerometer with high sensitivity at low frequency was designed to provide low frequency corrections for the feedback signal of the Advanced Laser Interferometer Gravitational Wave Observatory active seismic attenuation system. It has been developed using a Tungsten Carbide ceramic knife-edge hinge designed to avoid the mechanical 1/f noise believed to be intrinsic in polycrystalline metallic flexures. Design and construction details are presented; prototype data acquisition and control limitations are discussed. The instrument's characterization reported here shows that the hinge is compatible with being metal-hysteresis-free, and therefore also free of the 1/f noise generated by the dislocation Self-Organized Criticality in the metal. A tiltmeter of this kind will be effective to separate the ground tilt component from the signal of horizontal low frequency seismometers, and to correct the ill effects of microseismic tilt in advanced seismic attenuation systems

Relationship between mechanical factors and pelvic tilt in adults with and without low back pain.

Science.gov (United States)

Król, Anita; Polak, Maciej; Szczygieł, Elżbieta; Wójcik, Paweł; Gleb, Klaudia

2017-01-01

The assessment of the lumbo-pelvic complex parameters is the basic procedure during the examination of the patients with low back pain syndrome (LBP). The aim of the study was to define the relationship between pelvic tilt and following factors: age, BMI, ability to activate deep abdominal muscles, iliopsoas and hamstrings muscles length, lumbar lordosis and thoracic kyphosis angle value, in adults with and without low back pain. The study covered a group of 60 female students aged 20-26. Average age was 22 years ± 1.83 (median = 22.5 years). In order to investigate the relationship between the anterior pelvic tilt and the analysed variables, simple linear regression and multiple linear regression were carried out. Individuals with and without pain differed significantly in terms of age, p pain differed significantly in terms of the anterior pelvic tilt. The risk of LBP incidence increased with age in the study group.

Design and initial characterization of a compact, ultra high vacuum compatible, low frequency, tilt accelerometer

Energy Technology Data Exchange (ETDEWEB)

O’Toole, A., E-mail: amandajotoole@gmail.com, E-mail: riccardo.desalvo@gmail.com [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States); Peña Arellano, F. E. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Rodionov, A. V.; Kim, C. [California Institute of Technology, Pasadena, California 91125 (United States); Shaner, M.; Asadoor, M. [Mayfield Senior School, 500 Bellefontaine Street Pasadena, California 91105 (United States); Sobacchi, E. [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Dergachev, V.; DeSalvo, R., E-mail: amandajotoole@gmail.com, E-mail: riccardo.desalvo@gmail.com [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); Bhawal, A. [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States); Gong, P. [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China); Lottarini, A. [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Minenkov, Y. [Sezione INFN Tor Vergata, via della Ricerca Scientfica 1, 00133 Roma (Italy); Murphy, C. [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia)

2014-07-15

A compact tilt accelerometer with high sensitivity at low frequency was designed to provide low frequency corrections for the feedback signal of the Advanced Laser Interferometer Gravitational Wave Observatory active seismic attenuation system. It has been developed using a Tungsten Carbide ceramic knife-edge hinge designed to avoid the mechanical 1/f noise believed to be intrinsic in polycrystalline metallic flexures. Design and construction details are presented; prototype data acquisition and control limitations are discussed. The instrument's characterization reported here shows that the hinge is compatible with being metal-hysteresis-free, and therefore also free of the 1/f noise generated by the dislocation Self-Organized Criticality in the metal. A tiltmeter of this kind will be effective to separate the ground tilt component from the signal of horizontal low frequency seismometers, and to correct the ill effects of microseismic tilt in advanced seismic attenuation systems.

Optimization and limit of a tilt manipulation stage based on the electrowetting-on-dielectric principle

Science.gov (United States)

Tan, Xiao; Tao, Zhi; Suzuki, Kenji; Li, Haiwang

2017-12-01

This work designed a new tilt manipulation stage based on the electrowetting-on-dielectric (EWOD) principle as the actuating mechanism and investigated the performance of that stage. The stage was fabricated using a universal MEMS (Micro-Electro-Mechanical System) fabrication method. In the previously demonstrated form of this device, the tilt stage consisted of a top plate that functions as a mirror, a bottom plate that was designed for changing the shape of water droplets, and supporters that were fixed between the top and bottom plate. That device was actuated by a voltage applied to the bottom plate, resulting in a static electric force actuating the shape change in the droplets by moving the top plate in the vertical direction. Previous experimental results indicated that that device can tilt at up to ±1.8°, with a resolution of 7 μm in displacement and 0.05° in angle. By selecting the best combination of the dielectric layer, the tilt angle was maximized. The new device, fabricated using a common and straightforward fabrication method, avoids deflection of the top plate and grounding in the bottom plate. Because of the limit of Teflon and other MEMS materials, this device has a tilt angle in the range of 3.2-3.5° according to the experimental data for friction and the EWOD device limit, which is close to 1.8°. This paper also describe the investigation of the effects of various parameters, e.g., various dielectric materials, thicknesses, and droplet type and volume, on the performance of the stage. The results indicate that the apparent frictions coefficient of the solid-liquid interface may remain constant, i.e., the friction force is proportional to the normal support force and the apparent frictions coefficient.