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The optical wing aligning device of the Langley Field tunnel

Description: Described here is a convenient and accurate method of aligning the wing chord with the airflow. The device was developed to permit rapid and accurate alignment of airfoils and models with the airstream passing through the tunnel. It consists of three main parts: a projector, a reflector, and a target. The arrangement, which is shown in a figure, has proven satisfactory in operation. It is far better than the old method of sighting across a long batten, as the operator of a balance may see the target and correctly judge the accuracy of his alignment. Whereas the old method required two operators and several minutes time to align to within 1/10 degree, this method enables one operator to align a wing to within 1/100 of a degree in a few seconds. This method also has the advantage of being able to measure the angle of the wing while the tunnel is running. Thus, the true angle of incidence is shown.
Date: January 1921
Creator: Norton, F. H. & Bacon, D. L.
Partner: UNT Libraries Government Documents Department

cctbx news

Description: The 'Computational Crystallography Toolbox' (cctbx, http://cctbx.sourceforge.net/) is the open-source component of the Phenix project (http://www.phenix-online.org/). Most recent cctbx developments are geared towards supporting new features of the phenix.refine application. Thus, the open-source mmtbx (macromolecular toolbox) module is currently being most rapidly developed. In this article we give an overview of some of the recent developments. However, the main theme of this article is the presentation of a light-weight example command-line application that was specifically developed for this newsletter: sequence alignment and superposition of two molecules read from files in PDB format. This involves parameter input based on the Phil module presented in Newsletter No. 5, fast reading of the PDB files with the new iotbx.pdb.input class, simple sequence alignment using the new mmtbx.alignment module, and use of the Kearsley (1989) superposition algorithm to find the least-squares solution for superposing C-alpha positions. The major steps are introduced individually, followed by a presentation of the complete application. The example application is deliberately limited in functionality to make it concise enough for this article. The main goal is to show how the open-source components are typically combined into an application. Even though the example is quite specific to macromolecular crystallography, we believe it will also be useful for a small-molecule audience interested in utilizing the large open-source library of general crystallographic algorithms (see our previous articles in this newsletter series) to build an application. We describe recent developments of the Computational Crystallography Toolbox.
Date: November 22, 2006
Creator: Grosse-Kunstleve, Ralf W.; Zwart, Peter H.; Afonine, Pavel V.; Ioerger, Thomas R. & Adams, Paul D.
Partner: UNT Libraries Government Documents Department

Business/it Alignment: the Impact of Incentive Plans on the Development of Shared Vision

Description: This study, utilizing Preston and Karahanna’s framework for shared vision development and Agency Theory, explores the impact of vision development factors and factors associated with incentive plans on shared vision and alignment. Results of the study confirm the strong relationship between shared vision and alignment, and indicate that having an effective management team is important with respect to developing and maintaining shared vision and alignment within the organization. Several vision development factors such as using the language of the business, participation on the top management team (TMT), and having knowledge of the business impact shared vision through their influence on teamwork. Also, results of this study suggest that participation on the TMT by the CIO/IT leader is more important than the individual’s position in the organizational hierarchy. In addition, attributes associated with incentive plans such as achievable and clear measures, measures linked to organizational goals, measures that align the interests of the individual with those of the organization, regular plan reviews, and using a balanced scorecard approach with respect to incentive plan design positively impact teamwork and shared vision. For practitioners, this highlights the importance of incentive plans as powerful tools that can be used to reinforce shared vision, effective teamwork, and alignment within the organization. Also, the CIO/IT leader needs to be knowledgeable of the business and must fill the role of both a technologist as well as an enterprise leader. This person must be an evangelist communicating the value and benefits of IT to the rest of the organization.
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Date: December 2014
Creator: Johnson, Vess L.
Partner: UNT Libraries

Using aberration test patterns to optimize the performance of EUV aerial imaging microscopes

Description: The SEMATECH Berkeley Actinic Inspection Tool (AIT) is a prototype EUV-wavelength zoneplate microscope that provides high quality aerial image measurements of EUV reticles. To simplify and improve the alignment procedure we have created and tested arrays of aberration-sensitive patterns on EUV reticles and we have compared their images collected with the AIT to the expected shapes obtained by simulating the theoretical wavefront of the system. We obtained a consistent measure of coma and astigmatism in the center of the field of view using two different patterns, revealing a misalignment condition in the optics.
Date: June 16, 2009
Creator: Mochi, Iacopo; Goldberg, Kenneth A.; Miyakawa, Ryan; Naulleau, Patrick; Han, Hak-Seung & Huh, Sungmin
Partner: UNT Libraries Government Documents Department

A magnetorheological study of single-walled and multi-walled carbon nanotube dispersions in mineral oil and epoxy resin.

Description: Single wall carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) were dispersed in mineral oil and epoxy resin. The magnetorheological properties of these dispersions were studied using a parallel plate rheometer. Strain sweeps, frequency sweeps, magneto sweeps and steady shear tests were conducted in various magnetic fields. G', G", h* and ty increased with increasing magnetic field, which was partially attributed to the increasing degree of the alignment of nanotubes in a stronger magnetic field. The SWNT/mo dispersions exhibited more pronounced magnetic field dependence than SWNT/ep and MWNT/mo counterparts due to their much lower viscosity. The alignment of SWNTs in mineral oil increased with rising nanotube concentration up to 2.5vol% but were significantly restricted at 6.41vol% due to nanotube flocculation.
Date: May 2005
Creator: Yang, Zhengtao
Partner: UNT Libraries

Closed orbit response to quadrupole strength variation

Description: We derive two formulae relating the variation in closed orbit in a storage ring to variations in quadrupole strength, neglecting nonlinear and dispersive effects. These formulae correct results previously reported [1,2,3]. We compare the results of the formulae applied to the ATF with simulations using MAD, and consider their application to beam-based alignment.
Date: January 20, 2004
Creator: Wolski, Andrzej & Zimmermann, Frank
Partner: UNT Libraries Government Documents Department

LONGITUDINAL MISMATCH IN SCL AS A SOURCE OF BEAM HALO.

Description: An advantage of a proton Super-conducting Linac (SCL) is that RF cavities can be operated independently, allowing easier beam transport: and acceleration. But cavities are to be separated by drifts long enough to avoid they couple to each other. Moreover, cavities are placed in cryostats that include inactive insertions for cold-warm transitions; and interspersed are warm insertions for magnets and other devices. The SCL is then an alternating sequence of accelerating elements and drifts. No periodicity is present, and the longitudinal motion is not adiabatic. This has the consequence that the beam bunch ellipse will tumble, dilute and create a halo in the momentum plane because of inherent nonlinearities. When this is coupled to longitudinal space-charge forces, it may cause beam loss with latent activation of the accelerator components.
Date: June 19, 2003
Creator: RUGGIERO,A. G.
Partner: UNT Libraries Government Documents Department

Lithographic characterization of low-order aberrations in a 0.3-NAEUV microfield exposure tool

Description: Although tremendous progress has been made in the crucial area of fabrication of extreme ultraviolet (EUV) projection optics, the realization diffraction-limited high numerical aperture (NA) optics (above 0.2 NA) remains a concern. The highest NA EUV optics available to date are the 0.3-NA Microfield Exposure Tool (MET) optics used in an experimental exposure station at Lawrence Berkeley National Laboratory [1] and commercial METs [2] at Intel and SEMATECH-North. Even though these optics have been interferometrically demonstrated to achieve diffraction-limited wavefront quality, the question remains as to whether or not such performance levels can be maintained after installation of the optics into the exposure tool. Printing-based quantitative aberration measurements provide a convenient mechanism for the characterization of the optic wavefront error in the actual lithography tool. We present the lithographic measurement of low-order aberrations in the Berkeley MET tool, including a quantitative measurement of astigmatism and spherical error and a qualitative measurement of coma. The lithographic results are directly compared to interferometry results obtained from the same optic. Measurements of the Berkeley MET indicate either an alignment drift or errors in the interferometry on the order of 0.5 to 1 nm.
Date: March 1, 2006
Creator: Naulleau, Patrick; Cain, Jason; Dean, Kim & Goldberg, Kenneth A.
Partner: UNT Libraries Government Documents Department

Flow-Based Detection of Bar Coded Particles

Description: We have developed methods for flow control, electric field alignment, and readout of colloidal Nanobarcodes{copyright}. Our flow-based detection scheme leverages microfluidics and alternate current (AC) electric fields to align and image particles in a well-defined image plane. Using analytical models of the particle rotation in electric fields we can optimize the field strength and frequency necessary to align the particles. This detection platform alleviates loss of information in solution-based assays due to particle clumping during detection.
Date: June 24, 2005
Creator: Rose, K A; Dougherty, G M & Santiago, J G
Partner: UNT Libraries Government Documents Department

DUK - A Fast and Efficient Kmer Based Sequence Matching Tool

Description: A new tool, DUK, is developed to perform matching task. Matching is to find whether a query sequence partially or totally matches given reference sequences or not. Matching is similar to alignment. Indeed many traditional analysis tasks like contaminant removal use alignment tools. But for matching, there is no need to know which bases of a query sequence matches which position of a reference sequence, it only need know whether there exists a match or not. This subtle difference can make matching task much faster than alignment. DUK is accurate, versatile, fast, and has efficient memory usage. It uses Kmer hashing method to index reference sequences and Poisson model to calculate p-value. DUK is carefully implemented in C++ in object oriented design. The resulted classes can also be used to develop other tools quickly. DUK have been widely used in JGI for a wide range of applications such as contaminant removal, organelle genome separation, and assembly refinement. Many real applications and simulated dataset demonstrate its power.
Date: March 21, 2011
Creator: Li, Mingkun; Copeland, Alex & Han, James
Partner: UNT Libraries Government Documents Department

Anisotropic fiber alignment in composite structures

Description: High strength material composite structures are formed with oriented fibers to provide controlled anisotropic fibers. Fibers suspended in non-dilute concentrations (e.g., up to 20 volume percent for fibers having an aspect ratio of 20) in a selected medium are oriented by moving an axially spaced array of elements in the direction of desired fiber alignment. The array elements are generally perpendicular to the desired orientation. The suspension medium may also include sphere-like particles where the resulting material is a ceramic.
Date: December 31, 1992
Creator: Graham, A.L.; Mondy, L.A. & Guell, D.C.
Partner: UNT Libraries Government Documents Department

An Integrated Support and Alignment System for Large ILC Lattice Elements

Description: The manipulators used to support and position lattice elements are critical components of all particle accelerators. The increased use of large superconducting magnets and accelerator modules places even greater demands on these manipulators. However, the performance of these support systems has not kept pace with the advances made in other areas of accelerator technology. This results in accelerators that are difficult to align and may not be capable of achieving target luminosities. An innovative new type of positioning mechanism tailored to the requirements of the International Linear Collider is proposed. The Tri-Sphere System provides secure support for large lattice elements and precision adjustment in six degrees of freedom. Integrated target sockets allow the support system to be rapidly pre-aligned. The system’s kinematic design passively guides lattice elements into their correct location during installation. A complimentary Portable Actuation Unit provides the advantages of automated adjustment and allows these adjustments to be completely decoupled from surveying.
Date: May 15, 2013
Creator: Viola, Robert
Partner: UNT Libraries Government Documents Department

Transverse centroid oscillations in solenoidially focused beam transport lattices

Description: Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable"alignment functions" and"bending functions" that efficiently describe the characteristics of the centroid oscillations induced by mechanical misalignments of the solenoids and dipole steering elements. The alignment and bending functions depend only on properties of the ideal lattice in the absence of errors and steering and have associated expansion amplitudes set by the misalignments and steering fields. Applications of this formulation are presented for statistical analysis of centroid deviations, calculation of actual lattice misalignments from centroid measurements, and optimal beam steering.
Date: August 1, 2008
Creator: Lund, Steven M.; Wootton, Christopher J. & Lee, Edward P.
Partner: UNT Libraries Government Documents Department

Multiple Whole Genome Alignments Without a Reference Organism

Description: Multiple sequence alignments have become one of the most commonly used resources in genomics research. Most algorithms for multiple alignment of whole genomes rely either on a reference genome, against which all of the other sequences are laid out, or require a one-to-one mapping between the nucleotides of the genomes, preventing the alignment of recently duplicated regions. Both approaches have drawbacks for whole-genome comparisons. In this paper we present a novel symmetric alignment algorithm. The resulting alignments not only represent all of the genomes equally well, but also include all relevant duplications that occurred since the divergence from the last common ancestor. Our algorithm, implemented as a part of the VISTA Genome Pipeline (VGP), was used to align seven vertebrate and sixDrosophila genomes. The resulting whole-genome alignments demonstrate a higher sensitivity and specificity than the pairwise alignments previously available through the VGP and have higher exon alignment accuracy than comparable public whole-genome alignments. Of the multiple alignment methods tested, ours performed the best at aligning genes from multigene families?perhaps the most challenging test for whole-genome alignments. Our whole-genome multiple alignments are available through the VISTA Browser at http://genome.lbl.gov/vista/index.shtml.
Date: January 16, 2009
Creator: Dubchak, Inna; Poliakov, Alexander; Kislyuk, Andrey & Brudno, Michael
Partner: UNT Libraries Government Documents Department

Survey data of Booster magnet misalignments

Description: As a part of the ongoing Booster improvement project, all the available data on booster magnets are collected and tabulated. Data include not only the survey results available at present (July 2003) but the magnet moves as well. The main purpose of this exercise is not to provide a basis for the future magnet moves. Rather, the goal is to present the present knowledge on where magnets are and incorporate it into, for example, the MAD lattice file so that one can see the impact of misaligned magnets on the closed orbit in the absence of any corrections.
Date: August 18, 2003
Creator: Ohnuma, Sho
Partner: UNT Libraries Government Documents Department

Nuclear Spin Orientation Dependence of Magnetoconductance: A New Method for Measuring the Spin of Charged Excitations in the QHE

Description: A new method for measuring the spin of the electrically charged ground state excitations m the Q$j~j quantum Hall effect ia proposed and demonstmted for the tirst time in GaAs/AIGaAs nndtiquantum wells. The method is &sed on the nuclear spin orientation dependence of" the 2D dc conductivity y in the quantum Hall regime due to the nuclear hyperfine interaction. As a demonstration of this method the spin of the electrically charged excitations of the ground state is determined at filling factor v = 1.
Date: December 1, 1998
Creator: Bowers, C.R.; Reno, J.L.; Simmons, J.A. & Vitkalov, S.A.
Partner: UNT Libraries Government Documents Department

Emittance dilution due to slow alignment drifts in the main linacs of the NLC

Description: The tight tolerances in the main linacs of the Nest Linear Collider (NLC) result in a large sensitivity of the beam emittance to slow alignment drifts. Once the accelerator is tuned, the optimized emittances must be maintained. Slow alignments drifts will make resteering and reoptimization necessary. The frequency of these linac reoptimizations is an important parameter that determines how well the linear collider can be operated. We present simulation results that address this question for the main linacs of the NLC. We will show that the effects of alignment drifts can indeed be handled.
Date: September 1, 1996
Creator: Assmann, R.; Adolphsen, C. & Bane, K.
Partner: UNT Libraries Government Documents Department

Alignment and steering scenarios for the APT linac

Description: The Accelerator for the Production of Tritium (APT) requires a very high proton beam current (100 mA cw). Requirement for hands-on maintenance limits the beam spill to less than 0.2 nA/m along most of the linac. To achieve this, it is important to understand the effects of fabrication, installation and operational errors, establish realistic tolerances, and develop techniques for mitigating their consequences. A new code, PARTREX, statistically evaluates the effects of alignment, quadrupole field, and rf phase and amplitude errors in the linac. This paper reviews the effects of quadrupole misalignments and present two steering algorithms that minimize the potential for particle loss from the beam halo. These algorithms were tested on the 8-to-20 MeV portion of the APT linac.
Date: September 1, 1996
Creator: Stovall, J.E.; Gray, E.R.; Nath, S.; Takeda, H.; Wood, R.L.; Young, L.M. et al.
Partner: UNT Libraries Government Documents Department

Modeling RHIC using the standard machine formal accelerator description

Description: The Standard Machine Format (SMF) is a structured description of accelerator lattices which supports both the hierarchy of beam lines and generic lattice objects as well as those deviations (field errors, alignment efforts, etc.) associated with each component of the as-installed machine. In this paper we discuss the use of SMF to describe the Relativistic Heavy Ion Collider (RHIC) as well as the ancillary data structures (such as field quality measurements) that are necessarily incorporated into the RHIC SMF model. Future applications of SMF are outlined, including its use in the RHIC operational environment.
Date: July 1, 1997
Creator: Pilat, F.; Trahern, C.G. & Wei, J.
Partner: UNT Libraries Government Documents Department

Application of Roll-Isolated Inertial Measurement Units to the Instrumentation of Spinning Vehicles

Description: Roll-isolated inertial measurement units are developed at Sandia for use in the instrumentation, guidance, and control of rapidly spinning vehicles. Roll-isolation is accomplished by supporting the inertial instrument cluster (gyros and accelerometers) on a single gimbal, the axis of which is parallel to the vehicle's spin axis. A rotary motor on the gimbal is driven by a servo loop to null the roll gyro output, thus inertially stabilizing the gimbal and instrument cluster while the vehicle spins around it. Roll-isolation prevents saturation of the roll gyro by the high vehicle spin rate, and vastly reduces measurement errors arising from gyro scale factor and alignment uncertainties. Nine versions of Sandia-developed roll-isolated inertial measurement units have been flown on a total of 27 flight tests since 1972.
Date: December 1, 2000
Creator: BEADER,MARK E.
Partner: UNT Libraries Government Documents Department

Alignment tolerance of accelerating structures and corrections for future linear colliders

Description: The alignment tolerance of accelerating structures is estimated by tracking simulations. Both single-bunch and multi-bunch effects are taken into account. Correction schemes for controlling the single and multi-bunch emittance growth in the case of large misalignment are also tested by simulations.
Date: June 1, 1995
Creator: Kubo, K.; Adolphsen, C.; Bane, K.L.F.; Raubenheimer, T.O. & Thompson, K.A.
Partner: UNT Libraries Government Documents Department

Alignment and commissionig of the APS beamline front ends

Description: Fifteen out of forty phase-one beamline front ends have been installed in the storage-ring tunnel at the 7-GeV Advanced Photon Source (APS). For the front-end installation, a four-step alignment process was designed and consists of (1) prealigning the front-end components with support tables in the preassembly area, (2) installing the components with tables in the storage-ring tunnel and aligning relative to the APS global telescope survey network, (3) confirming the alignment using a tooling laser alignment system, and (4) performing adjustments with the synchrotron-radiation beam during commissioning. The laser alignment system and the prealignment data- base have been of great importance for the expedient maintenance of front-end components. These tools are very important to a large synchrotron radiation facility such as the APS, since they make a quick alignment setup possible and minimize alignment time inside the tunnel. This paper will present the four-step alignment process, the laser alignment system, and discuss the alignment confirmation results. 6 refs., 5 figs.
Date: December 31, 1995
Creator: Shu, D.; barraza, J.; Ramanathan, M.; Chang, J. & Kuzay, T.M.
Partner: UNT Libraries Government Documents Department