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Sample records for gd-tm lu-synthesis structure

  1. Magnesium substitutions in rare-earth metal germanides with the Gd5Si4 type. Synthesis, structure determination and magnetic properties of RE5-xMgxGe4 (RE=Gd-Tm, Lu and Y)

    Energy Technology Data Exchange (ETDEWEB)

    Sarrao, J L [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory; Tobash, P H [UNIV. OF DE; Bobev, S [UNIV. OF DE

    2009-01-01

    A series of magnesium-substituted rare-earth metal germanides with a general formula RE{sub 5-x}Mg{sub x}Ge{sub 4} (x {approx} 1.0-2.3; RE =Gd-Tm, Lu, Y) have been synthesized by high-temperature reactions and structurally characterized by single-crystal X-ray diffraction. These compounds crystallize with the common Gd{sub 5}Si{sub 4} type in the orthorhombic space group Pnma (No. 62; Z =4; Pearson's code oP36) and do not appear to undergo temperature-induced crystallographic phase transitions down to 120 K. Replacing rare-earth metal atoms with Mg, up to nearly 45 % at., reduces the valence electron count and is clearly expressed in the subtle changes of the Ge-Ge and metal-metal bonding. Magnetization measurements as a function of the temperature and the applied field reveal complex magnetic structures at cryogenic temperatures, and Curie-Weiss paramagnetic behavior at higher temperatures. The observed local moment magnetism is consistent with RE+ ground states in all cases. In the magnetically ordered phases, the magnetization cannot reach saturation in fields up to 50 kOe. The structural trends across the series and the variations of hte magnetic properties as a function of the Mg content are also discussed. KEYWORDS: Rare-earth intermetallics, germanides, crystal structure,Gd{sub 5}Si{sub 4} type.

  2. Equiatomic compounds REIrMg (RE = Y, La-Nd, Sm, Gd-Tm) and RERhMg (RE = Y, Sm, Gd-Tm)

    Science.gov (United States)

    Stein, Sebastian; Heletta, Lukas; Pöttgen, Rainer

    2017-09-01

    The equiatomic intermetallic compounds REIrMg (RE = Y, La-Nd, Sm, Gd-Tm) and RERhMg (RE = Y, Sm, Gd-Tm) were synthesized from the elements in sealed niobium ampoules in a high-frequency furnace and characterized based on X-ray powder data. LaIrMg and CeIrMg crystallize with the orthorhombic LaNiAl type structure (Pnma), while all other compounds adopt the TiNiSi type. The structures of YRhMg, GdRh1.190(4)Mg0.810(4), DyRh1.126(5)Mg0.874(5), LaIrMg, NdIr1.033(2)Mg0.967(2) and ErIr1.059(3)Mg0.941(3) were refined from single-crystal X-ray diffractometer data. The striking structural motifs of these phases are tricapped trigonal prisms around the transition metal atoms formed by RE and Mg. The two structure types differ in the connectivity pattern of the trigonal prisms. The rhodium (iridium) atoms build up three-dimensional [RhMg] and [IrMg] networks in which cavities are filled by the rare earth atoms. Temperature dependent magnetic susceptibility measurements on X-ray pure samples of NdIrMg, SmRhMg, GdRhMg, TbRhMg and DyRhMg show Curie-Weiss paramagnetism of the trivalent rare earth ions and magnetic ordering at low temperatures: TC = 9.5 K for NdIrMg and Néel temperatures of 10.0, 16.7, 10.6 and 11.3 K for SmRhMg, GdRhMg, TbRhMg and DyRhMg. TbRhMg and DyRhMg exhibit field-induced spin reorientations (metamagnetism).

  3. Magnetic and transport properties of i-R-Cd icosahedral quasicrystals (R=Y, Gd-Tm)

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Tai [Ames Laboratory; Bud' ko, Sergey L. [Ames Laboratory; Jesche, Anton [Ames Laboratory; McArthur, John [Quantum Design Japan; Kreyssig, Andreas [Ames Laboratory; Goldman, Alan I. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

    2014-07-01

    We present a detailed characterization of the recently discovered i-R-Cd (R=Y,Gd-Tm) binary quasicrystals by means of x-ray diffraction, temperature-dependent dc and ac magnetization, temperature-dependent resistance, and temperature-dependent specific heat measurements. Structurally, the broadening of x-ray diffraction peaks found for i-R-Cd is dominated by frozen-in phason strain, which is essentially independent of R. i-Y-Cd is weakly diamagnetic and manifests a temperature-independent susceptibility. i-Gd-Cd can be characterized as a spin glass below 4.6 K via dc magnetization cusp, a third order nonlinear magnetic susceptibility peak, a frequency-dependent freezing temperature, and a broad maximum in the specific heat. i-R-Cd (R=Ho-Tm) is similar to i-Gd-Cd in terms of features observed in thermodynamic measurements. i-Tb-Cd and i-Dy-Cd do not show a clear cusp in their zero-field-cooled dc magnetization data, but instead show a more rounded, broad local maximum. The resistivity for i-R-Cd is of order 300μΩ cm and weakly temperature dependent. The characteristic freezing temperatures for i-R-Cd (R=Gd-Tm) deviate from the de Gennes scaling, in a manner consistent with crystal electric field splitting induced local moment anisotropy.

  4. CeNi3-type rare earth compounds: crystal structure of R3Co7Al2 (R=Y, Gd-Tm) and magnetic properties of {Gd-Er}3Co7Al2, {Tb, Dy}3Ni8Si and Dy3Co7.68Si1.32

    Science.gov (United States)

    Morozkin, A. V.; Yapaskurt, V. O.; Nirmala, R.; Quezado, S.; Malik, S. K.

    2017-03-01

    The crystal structure of new CeNi3-type {Y, Gd-Tm}3Co7Al2 (P63/mmc. N 194, hP24) compounds has been established using powder X-ray diffraction studies. The magnetism of Tb3Ni8Si and Dy3Ni8Si is dominated by rare earth sublattice and the magnetic properties of R3Co7Al2 (R =Gd-Er) and Dy3Co7.68Si1.32 are determined by both rare earth and cobalt sublattices. Magnetization data indicate ferromagnetic ordering of {Tb, Dy}3Ni8Si at 32 K and 21 K, respectively. Gd3Co7Al2 and Tb3Co7Al2 exhibit ferromagnetic ordering at 309 K and 209 K, respectively, whereas Dy3Co7Al2, Ho3Co7Al2, Er3Co7Al2 and Dy3Co7.68Si1.32 show a field dependent ferromagnetic-like ordering at 166 K, 124 K, 84 K and 226 K, respectively followed by a low temperature transition at 34 K for Dy3Co7Al2, 18 K for Ho3Co7Al2, 56 K for Er3Co7Al2, 155 K and 42 K for Dy3Co7.68Si1.32. Among these compounds, Dy3Ni8Si shows largest magnetocaloric effect (isothermal magnetic entropy change) of -11.6 J/kg·K at 18 K in field change of 50 kOe, whereas Tb3Co7Al2, Dy3Co7Al2 and Dy3Co7.68Si1.32 exhibit best permanent magnet properties in the temperature range of 2-5 K with remanent magnetization of 11.95 μB/fu, 12.86 μB/fu and 14.4 μB/fu, respectively and coercive field of 3.0 kOe, 1.9 kOe and 4.4 kOe, respectively.

  5. Anisotropic magnetization and transport properties of RAgSb{sub 2} (R=Y, La-Nd, Sm, Gd-Tm)

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Kenneth D.

    1999-11-08

    This study of the RAgSb{sub 2} series of compounds arose as part of an investigation of rare earth intermetallic compounds containing antimony with the rare earth in a position with tetragonal point symmetry. Materials with the rare earth in a position with tetragonal point symmetry frequently manifest strong anisotropies and rich complexity in the magnetic properties, and yet are simple enough to analyze. Antimony containing intermetallic compounds commonly possess low carrier densities and have only recently been the subject of study. Large single grain crystals were grown of the RAgSb{sub 2} (R=Y, La-Nd, Sm, Gd-Tm) series of compounds out of a high temperature solution. This method of crystal growth, commonly known as flux growth is a versatile method which takes advantage of the decreasing solubility of the target compound with decreasing temperature. Overall, the results of the crystal growth were impressive with the synthesis of single crystals of LaAgSb{sub 2} approaching one gram. However, the sample yield diminishes as the rare earth elements become smaller and heavier. Consequently, no crystals could be grown with R=Yb or Lu. Furthermore, EuAgSb{sub 2} could not be synthesized, likely due to the divalency of the Eu ion. For most of the RAgSb{sub 2} compounds, strong magnetic anisotropies are created by the crystal electric field splitting of the Hund's rule ground state. This splitting confines the local moments to lie in the basal plane (easy plane) for the majority of the members of the series. Exceptions to this include ErAgSb{sub 2} and TmAgSb{sub 2}, which have moments along the c-axis (easy axis) and CeAgSb{sub 2}, which at intermediate temperatures has an easy plane, but exchange coupling at low temperatures is anisotropic with an easy axis. Additional anisotropy is also observed within the basal plane of DyAgSb{sub 2}, where the moments are restricted to align along one of the {l_angle}110{r_angle} axes. Most of the RAgSb{sub 2} compounds

  6. Pressure effect on ferroelectric properties of multiferroics RMn2O5, (R = Gd, Tm)

    Science.gov (United States)

    Poudel, Narayan; Gooch, Melissa; Lorenz, Bernd; Chu, Ching-Wu; Kim, Jaewook; Cheong, Sang-Wook

    The pressure effect on the ferroelectric properties of the multiferroics GdMn2O5 and TmMn2O5 is studied up to 18.2 kbar. Unlike in RMn2O5 (R= Tb, Ho, Y), no significant change in polarization is observed in TmMn2O5 up to 16.6 kbar . However, a new ferroelectric phase is observed in GdMn2O5 above a critical pressure, Pc = 10 kbar at higher temperature. Our result indicates that pressure decouples the Gd moment from the Mn spin system and splits the ferroelectric phase. Thermal expansion data shows a large increase of the c axis at the ambient-pressure ferroelectric transition. The pressure-induced contraction of the c lattice parameter is found to be the cause for splitting of ferroelectric phase by decoupling of two spin systems above Pc. The pressure-temperature phase diagram is derived based on dielectric and ferroelectric properties.

  7. Surface characterization and luminescence properties of AlN doped with RE elements (Sm, Ho, Gd, Tm)

    OpenAIRE

    Balogun, Ismail Ayodele

    2015-01-01

    Rare‐ earth (RE)‐doped III‐nitride broad band‐gap semiconductors have attracted enormous interest as a foundation for optoelectronics devices, which combine the unique luminescence feature of Rare‐earth ions with the electronic properties of the semiconductors. Recent progress toward nitride‐based light emitting diode and light emitting due to electric current devices have been made using crystalline and amorphous AlN and GaN doped with a different lanthanide elements. The Rare‐earth...

  8. Local structure studies of multiferroic RMn2O5 (R=Bi, Pr, Gd)

    Science.gov (United States)

    Fabbris, G.; Massa, N. E.; Granado, E.; Maciel, G. A.; Souza, J. A.; Alonso, J. A.; Martinez, M. J.; Azevedo, G. M.

    2009-03-01

    EXAFS measurements from 20 K to 300K were used to investigate the local structure of multiferroic RMn2O5 (R = Bi, Pr, Gd, TM TC 40K) in transmission mode at the Mn K- and R L3- edges in the XAFS2-LNLS beamline and analyzed using the IFEFFIT and FEFF codes. For BiMn2O5, Mn K-edge reveals very small temperature dependence of the Debye-Waller factor (DWF) and an Einstein temperature (ET) from Mn-O bonds of 675±22 K, suggesting that MnO polyhedra are rigid. We find structural distortions in the first coordination shell at the Bi L3-edge associated to vibrational anomalies in the Bi-O bonds. The quantitative analysis relates the origin of such distortions to two very distinct values of DWT and ET (294±7K and 462±28K) for these bonds on first shell. Similar behavior is observed for PrMn2O5, and GdMn2O5.

  9. New transition metal-rich rare-earth palladium/platinum aluminides with RET{sub 5}Al{sub 2} composition. Structure, magnetism and {sup 27}Al NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Benndorf, Christopher [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Stegemann, Frank; Janka, Oliver [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie

    2015-06-01

    REPd{sub 5}Al{sub 2} compounds with RE = Ce-Gd as well as Y and Lu have been previously synthesized. Although some compounds with the small lanthanides also exist, the compounds with intermediate-sized rare-earth elements (RE = Tb-Yb) had not been prepared. We report on the missing members of the REPd{sub 5}Al{sub 2} (RE = Tb-Yb) series as well as on the new REPt{sub 5}Al{sub 2} (RE = Y, Gd-Tm, Lu) series, which we have synthesized and structurally as well as magnetically characterized. All members crystallize isostructurally in the ZrNi{sub 2}Al{sub 5} type with an anti-arrangement of the T = Pd/Pt and Al atoms. YPd{sub 5}Al{sub 2} and LuPd{sub 5}Al{sub 2}, as well as the respective platinum homologs, YPt{sub 5}Al{sub 2} and LuPt{sub 5}Al{sub 2}, have been characterized also by {sup 27}Al magic-angle spinning nuclear magnetic resonance spectroscopy. Consistent with the XRD analysis, the spectra indicate the existence of only one distinct Al site in the structure.

  10. Structure and properties of intermetallic ternary rare earth compounds

    Energy Technology Data Exchange (ETDEWEB)

    Casper, Frederick

    2008-12-17

    The so called material science is an always growing field in modern research. For the development of new materials not only the experimental characterization but also theoretical calculation of the electronic structure plays an important role. A class of compounds that has attracted a great deal of attention in recent years is known as REME compounds. These compounds are often referred to with RE designating rare earth, actinide or an element from group 1-4, M representing a late transition metal from groups 8-12, and E belonging to groups 13-15. There are more than 2000 compounds with 1:1:1 stoichiometry belonging to this class of compounds and they offer a broad variety of different structure types. Although many REME compounds are know to exist, mainly only structure and magnetism has been determined for these compounds. In particular, in the field of electronic and transport properties relatively few efforts have been made. The main focus in this study is on compounds crystallizing in MgAgAs and LiGaGe structure. Both structures can only be found among 18 valence electron compounds. The f electrons are localized and therefor not count as valence electrons. A special focus here was also on the magnetoresistance effects and spintronic properties found among the REME compounds. An examination of the following compounds was made: GdAuE (E=In,Cd,Mg), GdPdSb, GdNiSb, REAuSn (RE=Gd,Er,Tm) and RENiBi (RE=Pr,Sm,Gd-Tm,Lu). The experimental results were compared with theoretic band structure calculations. The first half metallic ferromagnet with LiGaGe structure (GdPdSb) was found. All semiconducting REME compounds with MgAgAs structure show giant magnetoresistance (GMR) at low temperatures. The GMR is related to a metal-insulator transition, and the value of the GMR depends on the value of the spin-orbit coupling. Inhomogeneous DyNiBi samples show a small positive MR at low temperature that depends on the amount of metallic impurities. At higher fields the samples show a

  11. Structural cladding /clad structures:

    DEFF Research Database (Denmark)

    Beim, Anne

    2013-01-01

    tendencies, which can be traced in the use of materials, the structural features and the construction details of building systems in selected architectural works. With a particular focus at heavy constructions made of solid wood and masonry, and light weight constructions made of wooden frame structures...... do we see limitations of tectonic maneuver; how does the performative logic challenge the heavy building constructions....

  12. Lanthanide triangles sandwiched by tetranuclear copper complexes afford a family of hendecanuclear heterometallic complexes [Ln(III)3Cu(II)8] (Ln = La-Lu): synthesis and magnetostructural studies.

    Science.gov (United States)

    Iasco, Olga; Novitchi, Ghenadie; Jeanneau, Erwann; Luneau, Dominique

    2013-08-05

    Reaction in ethanol of 3-hydroxymethylen-5-methylsalicylaldoxime (H3L) with CuCl2·2H2O and LnCl3·xH2O [Ln = La (1), Ce (2), Pr (3), Nd (4), Eu (5), Gd (6), Tb (7), Dy (8), Er (9), Yb (10), Lu (11), Ho (12)] allowed the synthesis of a family of hendecanuclear heterometallic copper(II)-lanthanide(III) clusters with general formula [Ln(III)3Cu(II)8(HL)6(μ4-O)2Cl6(H2O)8]Cl3 (1-12). According to the single-crystal X-ray diffraction investigation, the complexes are isomorphous and crystallize in the trigonal R32 group. The hendecanuclear cluster is formed by two tetrahedral μ4-oxo {Cu4} clusters assembled by three lanthanide ions sandwiched in between. Along the family, the separation between the {Cu4} moieties increases linearly from Lu to La in good correlation with ionic radius of the lanthanide ions. A comparative analysis of the magnetic data for the lanthanum (1) and lutetium (11) compounds shows the presence of ferromagnetic and antiferromagnetic interactions within the μ4-oxo {Cu4} moieties. For the gadolinium (6) and terbium (7) compounds, the magnetic interactions between the lanthanide and the copper ions are found to be ferromagnetic. The dysprosium (8) compound exhibits single-molecule magnet behavior.

  13. Structural cladding /clad structures

    DEFF Research Database (Denmark)

    Beim, Anne

    2012-01-01

    of materials, the structural features and the construction details of building systems in selected architectural works. With a particular focus at heavy constructions made of solid wood and masonry, and light weight constructions made of wooden frame structures and steel profiles, it is the intention......, to ask for more restrictive building codes. As an example, in Denmark there are series of increasing demands in the current building legislations that are focused at enhancing the energy performance of buildings, which consequently foster rigid insulation standards and ask for improvement of air...... with at a global or national level. How to bring the knowledge, material evidence and cultural dimension, which exist in traditional building practices into play with present day hardcore technocratic demands in the construction industry and in building construction, seem be With point of departure...

  14. Structural cladding /clad structures

    DEFF Research Database (Denmark)

    Beim, Anne

    2012-01-01

    to analyze, compare, and discuss how these various construction solutions point out strategies for development based on fundamentally different mindsets. The research questions address the following issues: How to learn from traditional construction principles: When do we see limitations of tectonic maneuver...... in the challenges previously described this paper forms a ‘tectonic enquiry’ into contemporary building practice by looking at specific performative tendencies, which can be traced in the structural features and the construction details of selected building systems and architectural works. With a particular focus...... at heavy constructions made of solid wood and masonry, and light weight constructions made of wooden frame structures and steel profiles, it is the intention to analyze, compare, and discuss how these various construction solu-tions point out strategies for development based on fundamentally different...

  15. Distribution Structures

    NARCIS (Netherlands)

    Friedrich, H.; Tavasszy, L.A.; Davydenko, I.

    2013-01-01

    Distribution structures are important elements of the freight transportation system. Goods are routed via warehouses on their way from production to consumption. This chapter discusses drivers behind these structures, logistics decisions connected to distribution structures on the micro level, and

  16. STRUCTURAL GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140014Deng Lin(College of Resources and Environment,Southwest Petroleum University,Chengdu 610500,China)Structural Geometry and Structural Kinematics of the Jiulongshan Structure in the North Longmenshan Mountains(Acta Geologica Sichuan,ISSN1006-0995,CN51-1273/P,33(1),2013,p.1-2,11,1illus.,9refs.)Key words:plate geometry,structural analysis,Longmenshan Fault Zone

  17. Sentence Structure

    CERN Document Server

    Fabb, Nigel

    2012-01-01

    Sentence Structure:introduces the evidence for sentence structure and reveals its purposeis based on a problem-solving approach to languageteaches the reader how to identify word classes, such as noun, preposition and demonstrativeuses simple tree structures to analyse sentencescontains numerous exercises to encourage practical skills of sentence analysisincludes a database and exercises that compare the structure of English with other languages.The second edition of Sentence Structure has been revised and updated throughout and includes new material on tense, aspect, modality and the verb phr

  18. Coilgun structures

    Science.gov (United States)

    Andrews, J. A.

    1993-01-01

    Recent research into the optimal design of 'coilgun' structures has indicated that structural requirements are strong functions of launcher classification as well as acceleration mode. Attention is presently given to both closed-form and numerical analytical techniques for coaxial DC accelerator (DCA) structural-design calculations. The DCA is a multistage pulsed-induction launcher that makes extensive use of composite materials technology; measured plastic deformations of the armature after a high energy experiment are compared to FEM analysis predictions.

  19. Protein Structure

    Science.gov (United States)

    Asmus, Elaine Garbarino

    2007-01-01

    Individual students model specific amino acids and then, through dehydration synthesis, a class of students models a protein. The students clearly learn amino acid structure, primary, secondary, tertiary, and quaternary structure in proteins and the nature of the bonds maintaining a protein's shape. This activity is fun, concrete, inexpensive and…

  20. Tau structures

    Directory of Open Access Journals (Sweden)

    Jesus Avila

    2016-11-01

    Full Text Available Tau is a microtubule-associated protein that plays an important role in axonal stabilization, neuronal development, and neuronal polarity. In this review, we focus on the primary, secondary, tertiary and quaternary tau structures. We describe the structure of tau from its specific residues until its conformation in dimers, oligomers and larger polymers in physiological and pathological situations.

  1. Organisational Structure

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2006

    2006-01-01

    An understanding of organisational structure can provide guidance for organisations that want to change and innovate. Many writers agree that this understanding allows organisations to shape how their work is done to ultimately achieve their business goals--and that too often structure is given little consideration in business strategy and…

  2. Vcsel structure

    DEFF Research Database (Denmark)

    2015-01-01

    The invention relates to a VCSEL structure based on a novel grating reflector. The grating reflector comprises a grating layer with a contiguous core grating region having a grating structure, wherein an index of refraction of high-index sections of the grating structure is at least 2.......5, and wherein an index of refraction of low-index sections of the grating structure is less than 2. The core grating region defines a projection in a direction normal to the grating layer. The grating reflector further comprises a cap layer abutting the grating layer, and an index of refraction of the cap layer...... the projection of the core grating region, the grating layer is also abutted by a second low-index layer and/or by air, an index of refraction of the second low-index layer or air being less than 2. The VCSEL structure furthermore comprises a first reflector and an active region for providing a cavity...

  3. Structural Behaviour of Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning

    2013-01-01

    The present paper focuses on the comparison of several two-dimensional and three-dimensional reciprocal configurations. The goal of such comparison is to analyse the structural behaviour when changing the geometric parameters used to describe the geometry of reciprocal structures....

  4. Structured light in structured media

    Science.gov (United States)

    Zeng, Jinwei

    The objective of this dissertation is to investigate fundamental optical phenomena at the interface between two emerging fields of modern optics - structured light and micro/nano-structured optical materials. Until recently, these fields were developing in parallel yet independently. A majority of researchers in the field of metamaterials and photonic crystals considered "simple" linearly or circularly polarized light or Gaussian beam propagation in "structured" materials with properties not found in nature. However, in addition to conventional polarization states, light beams can be radially or azimuthally polarized and carry orbital angular momentum (OAM). A fascinating example of a beam carrying OAM is the optical vortex---a donut-shaped beam with a helical phase front. Similarly, the structured light community largely focused on complex light propagation in rather simple homogeneous, isotropic, transparent media. In this dissertation, we explore fundamentals and applications of light-matter interactions that involve both complex light and complex media. The central question that we aim to tackle is: How may the synergy of these two fields lead to a breakthrough in modern photonics? Structured materials, including metamaterials and photonic bandgap structures, realize unprecedented control over light propagation and design flexibility. They can enable new optical properties and functionalities, including new regimes of wave guiding, negative index of refraction, magnetism at optical frequencies, and subwavelength imaging to name a few. We demonstrate how nearly unlimited possibilities in engineering the properties of structured media can be used for generation and manipulation of structured light. Also, we show how the unique properties of structured light could be used for characterization of structured media.

  5. Hydraulic Structures

    Data.gov (United States)

    Department of Homeland Security — This table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the FIRM, channels containing the...

  6. Hydraulic structures

    CERN Document Server

    Chen, Sheng-Hong

    2015-01-01

    This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

  7. Nuclear Structure

    Science.gov (United States)

    Gargano, Angela

    2003-04-01

    An account of recent studies in the field of theoretical nuclear structure is reported. These studies concern essentially research activities performed under the Italian project "Fisica Teorica del Nucleo e dei Sistemi a Molti Corpi". Special attention is addressed to results obtained during the last two years as regards the development of new many-body techniques as well as the interpretation of new experimental aspects of nuclear structure.

  8. Foundation Structure

    OpenAIRE

    Schakenda, Bruno; Nielsen, Søren Andreas; Ibsen, Lars Bo

    2009-01-01

    Method of installing a bucket foundation structure comprising one, two, three or more skirts, into soils in a controlled manner. The method comprises two stages: a first stage being a design phase and the second stage being an installation phase. In the first stage, design parameters are determined relating to the loads on the finished foundation structure; soil profile on the location; allowable installation tolerances, which parameters are used to estimate the minimum diameter and length of...

  9. Tension Structure

    Science.gov (United States)

    1978-01-01

    The fabric structure pictured is the Campus Center of La Verne College, La Verne, California. Unlike the facilities shown on the preceding pages, it is not air-supported. It is a "tension structure," its multi-coned fabric membrane supported by a network of cables attached to steel columns which function like circus tent poles. The spider-web in the accompanying photo is a computer graph of the tension pattern. The designers, Geiger-Berger Associates PC, of New York City, conducted lengthy computer analysis to determine the the best placement of columns and cables. The firm also served as structural engineering consultant on the Pontiac Silverdome and a number of other large fabric structures. Built by Birdair Structures, Inc., Buffalo, New York, the La Verne Campus Center was the first permanent facility in the United States enclosed by the space-spinoff fabric made of Owens-Corning Beta fiber glass coated with Du Pont Teflon TFE. The flexible design permits rearrangement of the interior to accommodate athletic events, student activities, theatrical productions and other recreational programs. Use of fabric covering reduced building cost 30 percent below conventional construction.

  10. Adenovirus structure.

    Science.gov (United States)

    Rux, John J; Burnett, Roger M

    2004-12-01

    Structural studies continue to play an essential role as the focus of adenovirus research shifts in emphasis from basic biology to adenovirus-based vector technologies. A crucial step in developing novel therapeutics for gene replacement, cancer, and vaccines is often to modify the virion. Such engineered changes are designed to retarget the virus, or to reduce the immunological responses to infection. These efforts are far more effective when they are based on detailed structural knowledge. This minireview provides a brief summary of the wealth of information that has been obtained from the combined application of X-ray crystallography and electron microscopy. This knowledge now includes a good working model for the architectural organization of the virion, and atomic resolution molecular structures for all the major capsid proteins, hexon, penton, and fiber. We highlight new developments, which include the structure of the penton base and the discovery that adenovirus has several relatives. We sketch how the structural information can be used to engineer novel virions and conclude with the prospects for future progress.

  11. Data Structures

    DEFF Research Database (Denmark)

    Davoodi, Pooya

    weight in a query path; (3) the range diameter problem: given a point set in the plane, find two points that are farthest away in a query rectangle. These and similar problems arise in various applications including document retrieval, genome sequence analysis, OLAP data cubes, network flows, shape......-fitting, and clustering. The three mentioned problems are considered for either static inputs or dynamic inputs. In the static setting, we investigate the space-efficiency of data structures, which is an important aspect in massive data algorithmics. We provide lower bounds on the trade-off between the query time......-dimensional range minimum queries. In the dynamic setting, we present data structures for the path minima problem that support optimal query time for various types of update operations. One of the results presents a comparison-based data structure which answers path minima queries in sub-logarithmic time...

  12. Fireplace structure

    Energy Technology Data Exchange (ETDEWEB)

    Faehling, F.L.; Billmeyer, T.F.; Peterson, S.O.

    1984-09-18

    A fireplace having one or more conduits for directing outside combustion air into the firebox with a movable member adjacent a conduit outlet for normally closing said conduit and having either open or closed positions dependent upon the existence of a pressure difference across said member. A pressure difference caused by a fire in the firebox results in a higher pressure on the side of the member opposite the firebox to cause the member to move to open position. Operating structure is provided for positively closing the member and with the operating structure being operable from the front of the fireplace.

  13. Lightweight Structures.

    Science.gov (United States)

    Shaver and Co., Michigan City, IN.

    One of the newest and most promising developments in architecture has been the use of lightweight structures for encapsulating space. Using this new technology, builders can enclose large and small areas at a fraction of the cost of conventional construction and at the same time provide interior space that is totally flexible. This brochure shows…

  14. Structural parsing

    NARCIS (Netherlands)

    Hoede, C.; Zhang, Lei

    2000-01-01

    Parsing is an essential part of natural language processing. In this paper, structural parsing, which is based on the theory of knowledge graphs, is introduced. Under consideration of the semantic and syntactic features of natural language, both semantic and syntactic word graphs are formed. Grammar

  15. Coastal Structures

    DEFF Research Database (Denmark)

    Oumeraci, H.; Burcharth, H. F.; Rouck, J. De;

    1995-01-01

    The paper attempts to present an overview of five research projects supported by the Commission of the European Communities, Directorate General XII, under the MAST 2- Programme (Marine Sciences and Technology), with the overall objective of contributing to the development of improved rational me...... methods for the design of coastal structures....

  16. Organizational structure

    NARCIS (Netherlands)

    Hendriks, P.H.J.

    2011-01-01

    For many decades, organization scientists have paid considerable attention to the link between knowledge and organization structure. An early contributor to these discussions was Max Weber (1922), who elaborated his concepts of professional bureaucracy. History shows a multitude of other description

  17. STRUCTURAL GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20130642 Bai Daoyuan (Hunan Institute of Geology Survey , Mineral Exploration and Development of Hunan Province , Changsha 410011 , China); Jia Baohua Potential Genesis of the Trending Changes of Jinning Period and Caledonian Structural Lineamens in Middle-Southern Hunan Province (Journal of Geomechanics , ISSN1006-6616 ,

  18. European structuralism

    OpenAIRE

    Willems, Klaas

    2014-01-01

    European structuralism is a paradigm for the study of language developed by prominent European linguists during the inter-war period and the first decades after World War II that radically rejected the prevailing atomism of 19th century (particularly neo-grammarian) linguistics and language psychology.

  19. Nuclear structure

    CERN Document Server

    Nazarewicz, W

    1999-01-01

    Current developments in nuclear structure are discussed from a theoretical perspective. The studies of the nuclear many-body system provide us with invaluable information about the nature of the nuclear interaction, nucleonic correlations at various energy-distance scales, and the modes of the nucleonic matter.

  20. Data Structures

    DEFF Research Database (Denmark)

    Davoodi, Pooya

    We study data structures for variants of range query problems. In particular, we consider (1) the range minimum problem: given a multidimensional array, find the position of the minimum element in a query rectangle; (2) the path minima problem: given a weighted tree, find the edge with minimum...... weight in a query path; (3) the range diameter problem: given a point set in the plane, find two points that are farthest away in a query rectangle. These and similar problems arise in various applications including document retrieval, genome sequence analysis, OLAP data cubes, network flows, shape......-fitting, and clustering. The three mentioned problems are considered for either static inputs or dynamic inputs. In the static setting, we investigate the space-efficiency of data structures, which is an important aspect in massive data algorithmics. We provide lower bounds on the trade-off between the query time...

  1. Syllable structure

    Directory of Open Access Journals (Sweden)

    Jakobsen Per

    2008-01-01

    Full Text Available In traditional structuralist understanding, language is a system of signs i.e. an inseparable unity of content and expression. According to glossematic linguistic theory, the dichotomy of form and substance in the content has its parallel in the expression. The present paper shows that in one language certain consonant clusters within the syllable are allowed, in other languages they are not. The phonotactic structure, i.e. the rules of forming syllables decide the forming of new words and identify the language at the same time. This fundamental syllable structure shows that it is scientifically untenable to maintain that the Serbo-Croatian language has split up in several new languages. .

  2. Concrete structures

    CERN Document Server

    Setareh, Mehdi

    2017-01-01

    This revised, fully updated second edition covers the analysis, design, and construction of reinforced concrete structures from a real-world perspective. It examines different reinforced concrete elements such as slabs, beams, columns, foundations, basement and retaining walls and pre-stressed concrete incorporating the most up-to-date edition of the American Concrete Institute Code (ACI 318-14) requirements for the design of concrete structures. It includes a chapter on metric system in reinforced concrete design and construction. A new chapter on the design of formworks has been added which is of great value to students in the construction engineering programs along with practicing engineers and architects. This second edition also includes a new appendix with color images illustrating various concrete construction practices, and well-designed buildings. The ACI 318-14 constitutes the most extensive reorganization of the code in the past 40 years. References to the various sections of the ACI 318-14 are pro...

  3. Terminal structure

    Science.gov (United States)

    Schmidt, Frank; Allais, Arnaud; Mirebeau, Pierre; Ganhungu, Francois; Lallouet, Nicolas

    2009-10-20

    A terminal structure (2) for a superconducting cable (1) is described. It consists of a conductor (2a) and an insulator (2b) that surrounds the conductor (2a), wherein the superconducting cable (1) has a core with a superconducting conductor (5) and a layer of insulation that surrounds the conductor (5), and wherein the core is arranged in such a way that it can move longitudinally in a cryostat. The conductor (2a) of the terminal structure (2) is electrically connected with the superconducting conductor (5) or with a normal conductor (6) that is connected with the superconducting conductor (5) by means of a tubular part (7) made of an electrically conductive material, wherein the superconducting conductor (5) or the normal conductor (6) can slide in the part (7) in the direction of the superconductor.

  4. Lightweight Structures

    Science.gov (United States)

    Whittenberger, J. Daniel

    2001-01-01

    Present structural concepts for hot static structures are conventional "sheet & stringer" or truss core construction. More weight-efficient concepts such as honeycomb and lattice block are being investigated, in combination with both conventional superalloys and TiAl. Development efforts for components made from TiAl sheet are centered on lower cost methods for sheet and foil production, plus alloy development for higher temperature capability. A low-cost casting technology recently developed for aluminum and steel lattice blocks has demonstrated the required higher strength and stiffness, with weight efficiency approach- ing honeycombs. The current effort is based on extending the temperature capability by developing lattice block materials made from IN-718 and Mar-M247.

  5. STRUCTURAL GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>20122174 Bai Daoyuan ( Institute of Geological Survey of Hunan Province,Changsha 410011,China );Jia Baohua Neoproterozoic TectonicEvolution of the Xuefeng Orogenic Zone in Hunan Province ( Sedimentary Geology and Tethyan Geology,ISSN1009-3850,CN51-1593 / P,31 ( 3 ), 2011,p.78-87,2illus.,1 table,96refs. ) Key words:structural evolution,Neoproterozoic Era,Hunan Province This paper deals,on the basis of abundant lithogeochemical and geochronologic

  6. Structural dynamics

    CERN Document Server

    Strømmen, Einar N

    2014-01-01

    This book introduces to the theory of structural dynamics, with focus on civil engineering structures that may be described by line-like beam or beam-column type of systems, or by a system of rectangular plates. Throughout this book the mathematical presentation contains a classical analytical description as well as a description in a discrete finite element format, covering the mathematical development from basic assumptions to the final equations ready for practical dynamic response predictions. Solutions are presented in time domain as well as in frequency domain. Structural Dynamics starts off at a basic level and step by step brings the reader up to a level where the necessary safety considerations to wind or horizontal ground motion induced dynamic design problems can be performed. The special theory of the tuned mass damper has been given a comprehensive treatment, as this is a theory not fully covered elsewhere. For the same reason a chapter on the problem of moving loads on beams has been included.

  7. Microplastic Structures

    Science.gov (United States)

    Feely, Wayne E.

    1986-07-01

    Thick coatings (5-15μm) of a new dual image, aqueous developable photoresist can be exposed using a light attenuating photomask consisting of clear, opaque and grey areas and then processed to yield thermally stable 3-dimensional structures which are potentially useful as mechanical and optical components of devices. In the positive mode, relief and intaglio images are produced by processing similar to positive novolak based resists with 1- 2μm resolution and with the added feature that the images can be made thermally stable to temperatures >300° C. Negative mode processing of coated wafers imaged with the special mask produces thermally stable structures with tunnels or hollow chambers as well as cantilever beams. Because these structures are crosslinked at the time of development, processing in the negative mode shows much wider latitude than is the case in the positive mode. Images by negative mode processing are capable of submicron resolution, higher aspect ratio (>3 vs resin compositions cover a broad range of compositions so that resins can be tailored to meet specific property requirements.

  8. STRUCTURED BACKWARD ERRORS FOR STRUCTURED KKT SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Xin-xiu Li; Xin-guo Liu

    2004-01-01

    In this paper we study structured backward errors for some structured KKT systems.Normwise structured backward errors for structured KKT systems are defined, and computable formulae of the structured backward errors are obtained. Simple numerical examples show that the structured backward errors may be much larger than the unstructured ones in some cases.

  9. Stoker structure

    Energy Technology Data Exchange (ETDEWEB)

    Mros, F.

    1981-11-10

    A screw-conveyor or auger feed and associated leveling system are disclosed for underfeed stoker troughs receiving particulate, cominuted, or chunk material, such as ''green'' coal, by way of example, this for assuring a uniformly rising level of material relative to the trough. The stoker structure herein includes combustion beds which are air perforate and kept this way through periodically rising members such as tuyeres which shear or break up clinkerformation on such beds. A pneumatically-operated system may preferably be used to actuate such movable tuyeres relative to such combustion beds. Combustion air flows through the combustion beds upwardly but not over the trough; hot gasses rising rapidly from the combustion beds confine volatiles gently rising vertically from the cone within the trough for complete combustion, essentially eliminating smoke-production thereat.

  10. Structural Discrimination

    DEFF Research Database (Denmark)

    Thorsen, Mira Skadegård

    In this article, I discuss structural discrimination, an underrepresented area of study in Danish discrimination and intercultural research. It is defined here as discursive and constitutive, and presented as a central element of my analytical approach. This notion is employed in the with which...... to understand and identify aspects of power and asymmetry in communication and interactions. With this as a defining term, I address how exclusion and discrimination exist, while also being indiscernible, within widely accepted societal norms. I introduce the concepts of microdiscrimination and benevolent...... discrimination as two ways of articulating particular, opaque forms of racial discrimination that occur in everyday Danish (and other) contexts, and have therefore become normalized. I present and discuss discrimination as it surfaces in data from my empirical studies of discrimination in Danish contexts...

  11. Structural Bionic Design of Machine Tool Structures

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ling; WANG Ting; GUO Hong-liang; LI Guo-meng

    2011-01-01

    A structural bionic design process is systematically presented for lightweight mechanical structures. By mimicking biological excellent structural principles, the stiffening ribs of a machining table and a moving column were redesigned for better load-bearing efficiency. Finite element method(FEM) simulation and model experiments were carried out for performance verification, which showed the increase of structural static and dynamic performance. Structural bionic offers a new solution to change conventional structures for high specific stiffness.

  12. Asteroid structure

    Science.gov (United States)

    Asphaug, E.

    2014-07-01

    Even before the first space missions to asteroids, in the mid-1990s, it was known that asteroids have weird structures. Photometry indicated complicated shapes, and the pioneering radar investigations by Ostro and colleagues followed by adaptive optics campaigns and flybys showed odd binary forms, and confirmed the common presence of satellites, and indications of highly varying surface roughness. Some asteroids turned out to be dominated by a single major cratering event, while others showed no evidence of a major crater, or perhaps for global crater erasure. The first space mission to orbit an asteroid, NEAR, found a mixture of heavily cratered terrains and geomorphically active 'ponds', and indicated evidence for global seismicity from impact. The next mission to orbit an asteroid, Hayabusa, found what most agree is a rubble pile, with no major craters and an absence of fines. There is to date no direct evidence of asteroid interior geology, other than measurements of bulk density, and inferences made for mass distribution asymmetry based on dynamics, and inferences based on surface lineaments. Interpolating from the surface to the interior is always risky and usually wrong, but of course the answer is important since we are someday destined to require this knowledge in order to divert a hazardous asteroid from impact with the Earth. Even considering the near-subsurface, here we remain as ignorant as we were about the Moon in the early 1960s, whether the surface will swallow us up in dust, or will provide secure landing and anchoring points. Laboratory experimentation in close to zero-G is still in its early stages. Adventures such as mining and colonization will surely have to wait until we better know these things. How do we get from here to there? I will focus on 3 areas of progress: (1) asteroid cratering seismology, where we use the surface craters to understand what is going on inside; (2) numerical modeling of collisions, which predicts the internal

  13. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area ​Other Fact Sheets What is structural biology? Structural biology is the study of how biological ...

  14. Collapsible Geostrut Structure

    Science.gov (United States)

    Robertson, Glen A.

    1994-01-01

    Portable truss structure collapsible into smaller volume for storage and transportation. At new site, reerected quickly, without need to reassemble parts. Structure could be tent, dome, tunnel, or platform. Key element in structure joint, called "geostrut joint," includes internal cable. Structure is network of struts attached to geostrut joints. Pulling cables taut in all joints makes structure rigid. Releasing cables relaxes structure.

  15. Magnetic multilayer structure

    Energy Technology Data Exchange (ETDEWEB)

    Herget, Philipp; O' Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2017-03-21

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  16. Magnetic multilayer structure

    Science.gov (United States)

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2016-07-05

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  17. Structural Analysis of Plate Based Tensegrity Structures

    DEFF Research Database (Denmark)

    Hald, Frederik; Kirkegaard, Poul Henning; Damkilde, Lars

    2013-01-01

    Plate tensegrity structures combine tension cables with a cross laminated timber plate and can then form e.g. a roof structure. The topology of plate tensegrity structures is investigated through a parametric investigation. Plate tensegrity structures are investigated, and a method...... for determination of the structures pre-stresses is used. A parametric investigation is performed to determine a more optimized form of the plate based tensegrity structure. Conclusions of the use of plate based tensegrity in civil engineering and further research areas are discussed....

  18. Structural Analysis of Plate Based Tensegrity Structures

    DEFF Research Database (Denmark)

    Hald, Frederik; Kirkegaard, Poul Henning; Damkilde, Lars

    2013-01-01

    Plate tensegrity structures combine tension cables with a cross laminated timber plate and can then form e.g. a roof structure. The topology of plate tensegrity structures is investigated through a parametric investigation. Plate tensegrity structures are investigated, and a method...... for determination of the structures pre-stresses is used. A parametric investigation is performed to determine a more optimized form of the plate based tensegrity structure. Conclusions of the use of plate based tensegrity in civil engineering and further research areas are discussed....

  19. Computational structural mechanics for engine structures

    Science.gov (United States)

    Chamis, C. C.

    1989-01-01

    The computational structural mechanics (CSM) program at Lewis encompasses: (1) fundamental aspects for formulating and solving structural mechanics problems, and (2) development of integrated software systems to computationally simulate the performance/durability/life of engine structures. It is structured to mainly supplement, complement, and whenever possible replace, costly experimental efforts which are unavoidable during engineering research and development programs. Specific objectives include: investigate unique advantages of parallel and multiprocesses for: reformulating/solving structural mechanics and formulating/solving multidisciplinary mechanics and develop integrated structural system computational simulators for: predicting structural performances, evaluating newly developed methods, and for identifying and prioritizing improved/missing methods needed. Herein the CSM program is summarized with emphasis on the Engine Structures Computational Simulator (ESCS). Typical results obtained using ESCS are described to illustrate its versatility.

  20. Common structure-balance between spacetime structure and massenergy structure

    Science.gov (United States)

    Cao, Daqing; Cao, Dayong

    2017-01-01

    According to Einstein field equation, there is a balance between spacetime structure and massenergy structure. nd the paper consider it as a common structurewhich was brought forward by Daqing Cao in 2011 ecause it is general structure in the universe and everything have the same model of structure in their one system. The Jovian planets is spacetime structure of solar system because they are gas-sphere and they have more density of spacetime (spacetime/massenergy) than the density of massenergy (massenergy/spacetime). The terrestrial planets is massenergy structure of solar system because they are rock-ball and they have more density of massenergy than the density of spacetime. That can explain of that the Jovian planets of big mass is far away from sun. With the idea that the wave is spacetime and the wave effect is spacetime structure, the planets have elliptic orbits and the same direction of their revolution. Because sun is like a massenergy center of the massenergy structure and the terrestrial planets, the paper supposes there is a dark sun-a dark hole who has a spacetime center of spacetime structure and influences on the orbits of the Jovian planets. http://meetings.aps.org/Meeting/APR16/Session/M13.8

  1. Offshore Structural Control Considering Fluid Structure Interaction

    Institute of Scientific and Technical Information of China (English)

    Ju Myung KIM; Dong Hyawn KIM; Gyu Won LEE

    2006-01-01

    Tuned Mass Damper (TMD) was applied to an offshore structure to control ocean wave-induced vibration. In the analysis of the dynamic response of the offshore structure, fluid-structure interaction is considered and the errors, which occur in the linearization of the interaction, are investigated. For the investigation of the performance of TMD in controlling the vibration, both regular waves with different periods and irregular waves with different significant wave heights are used. Based on the numerical analysis it is concluded that the fluid-structure interaction should be considered in the evaluation of the capability of TMD in vibration control of offshore structures.

  2. Designing pliable structural Skins

    DEFF Research Database (Denmark)

    Tamke, Martin; Peters, Brady; Nielsen, Stig Anton;

    2013-01-01

    Structural stability can be formed through structured or seemingly unstructured approaches to fold, plead or crumble paper. This paper reports on two projects that showcase how computational design approaches can help to widen the understanding and use of structural skins....

  3. Study of Boundary Structures.

    Science.gov (United States)

    1982-09-01

    THEORY OF ABC-CBA STACKING BOUNDARY IN fcc STRUCTURE .......... 11 - 4 TRANSITIONS AND PHASE EQUILIBRIA AMONG GRAIN BOUNDARY STRUCTURES...19 B THEORY OF ABC-CBA STACKING BOUNDARY IN fcc STRUCTURE .......... 37 C TRANSITIONS AND PHASE EQUILIBRIA AMONG GRAIN BOUNDARY...layer structure. 10 SECTION 3 THEORY OF ABC-CBA STACKING BOUNDARY IN fcc STRUCTURE The (111) planes of the fcc structure is stacked as ABCABC... as

  4. Protein structure search and local structure characterization

    Directory of Open Access Journals (Sweden)

    Ku Shih-Yen

    2008-08-01

    Full Text Available Abstract Background Structural similarities among proteins can provide valuable insight into their functional mechanisms and relationships. As the number of available three-dimensional (3D protein structures increases, a greater variety of studies can be conducted with increasing efficiency, among which is the design of protein structural alphabets. Structural alphabets allow us to characterize local structures of proteins and describe the global folding structure of a protein using a one-dimensional (1D sequence. Thus, 1D sequences can be used to identify structural similarities among proteins using standard sequence alignment tools such as BLAST or FASTA. Results We used self-organizing maps in combination with a minimum spanning tree algorithm to determine the optimum size of a structural alphabet and applied the k-means algorithm to group protein fragnts into clusters. The centroids of these clusters defined the structural alphabet. We also developed a flexible matrix training system to build a substitution matrix (TRISUM-169 for our alphabet. Based on FASTA and using TRISUM-169 as the substitution matrix, we developed the SA-FAST alignment tool. We compared the performance of SA-FAST with that of various search tools in database-scale search tasks and found that SA-FAST was highly competitive in all tests conducted. Further, we evaluated the performance of our structural alphabet in recognizing specific structural domains of EGF and EGF-like proteins. Our method successfully recovered more EGF sub-domains using our structural alphabet than when using other structural alphabets. SA-FAST can be found at http://140.113.166.178/safast/. Conclusion The goal of this project was two-fold. First, we wanted to introduce a modular design pipeline to those who have been working with structural alphabets. Secondly, we wanted to open the door to researchers who have done substantial work in biological sequences but have yet to enter the field of protein

  5. Deployable Composite Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is seeking innovative structure technologies that will advance expandable modules for orbital and surface based habitats. These secondary structures must...

  6. Composite Structures Manufacturing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Composite Structures Manufacturing Facility specializes in the design, analysis, fabrication and testing of advanced composite structures and materials for both...

  7. Distributed Structure Searchable Toxicity

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Distributed Structure Searchable Toxicity (DSSTox) online resource provides high quality chemical structures and annotations in association with toxicity data....

  8. Protein structure mining using a structural alphabet.

    Science.gov (United States)

    Tyagi, M; de Brevern, A G; Srinivasan, N; Offmann, B

    2008-05-01

    We present a comprehensive evaluation of a new structure mining method called PB-ALIGN. It is based on the encoding of protein structure as 1D sequence of a combination of 16 short structural motifs or protein blocks (PBs). PBs are short motifs capable of representing most of the local structural features of a protein backbone. Using derived PB substitution matrix and simple dynamic programming algorithm, PB sequences are aligned the same way amino acid sequences to yield structure alignment. PBs are short motifs capable of representing most of the local structural features of a protein backbone. Alignment of these local features as sequence of symbols enables fast detection of structural similarities between two proteins. Ability of the method to characterize and align regions beyond regular secondary structures, for example, N and C caps of helix and loops connecting regular structures, puts it a step ahead of existing methods, which strongly rely on secondary structure elements. PB-ALIGN achieved efficiency of 85% in extracting true fold from a large database of 7259 SCOP domains and was successful in 82% cases to identify true super-family members. On comparison to 13 existing structure comparison/mining methods, PB-ALIGN emerged as the best on general ability test dataset and was at par with methods like YAKUSA and CE on nontrivial test dataset. Furthermore, the proposed method performed well when compared to flexible structure alignment method like FATCAT and outperforms in processing speed (less than 45 s per database scan). This work also establishes a reliable cut-off value for the demarcation of similar folds. It finally shows that global alignment scores of unrelated structures using PBs follow an extreme value distribution. PB-ALIGN is freely available on web server called Protein Block Expert (PBE) at http://bioinformatics.univ-reunion.fr/PBE/.

  9. Structural behaviour of super-light structures

    DEFF Research Database (Denmark)

    Bagger, Anne; Hertz, Kristian Dahl

    2010-01-01

    with a lighter and softer material, such as lightweight concrete. The combined use of stiff and light material in SLS results in structures of high stiffness and low weight. The applied technology and the advantages of SLS are elaborated upon in [1] in these proceedings. The present paper focuses......A new structural concept, called Super-light Structures (SLS), has recently been invented and patented at the Technical University of Denmark. The basic concept of SLS is to construct a skeleton of a stiff and strong material, such as ordinary or high strength concrete, and stabilize this skeleton...... on the structural correlation between the stiff material and the light material. The shape of the skeleton can be optimized for the primary load on the structure, and it will take up the majority of the load. The lighter material forms the outer geometry of the structural component (e.g. a wall), and has several...

  10. Chinese Conversation Structure

    Institute of Scientific and Technical Information of China (English)

    LIU Yan

    2016-01-01

    This paper aims to describe the features of Chinese conversation structure. Specifically speaking, the structure will be analyzed from the following four aspects:openings and pre-sequence, adjacency pairs, pre-closing and closing. Generally speak-ing, Chinese conversation structure is similar to English conversation structure. But still a lot of differences are found due to cul-tural factors.

  11. Crystal structure and prediction.

    Science.gov (United States)

    Thakur, Tejender S; Dubey, Ritesh; Desiraju, Gautam R

    2015-04-01

    The notion of structure is central to the subject of chemistry. This review traces the development of the idea of crystal structure since the time when a crystal structure could be determined from a three-dimensional diffraction pattern and assesses the feasibility of computationally predicting an unknown crystal structure of a given molecule. Crystal structure prediction is of considerable fundamental and applied importance, and its successful execution is by no means a solved problem. The ease of crystal structure determination today has resulted in the availability of large numbers of crystal structures of higher-energy polymorphs and pseudopolymorphs. These structural libraries lead to the concept of a crystal structure landscape. A crystal structure of a compound may accordingly be taken as a data point in such a landscape.

  12. Strategy implemented through structuring and new structures

    DEFF Research Database (Denmark)

    Nielsen, Renate

    Research objective: With the purpose of generating a new understanding of how development in organisations take place, an interpretive perspective at continuous processes in organisations will be applied: more specifically at how organisational interpretation forms an organisation's strategy...... and how the strategy is implemented through structuring, new structures and routines....

  13. Internal structure of structurally stitched NCF preform

    NARCIS (Netherlands)

    Koissin, V.; Ruopp, A.; Lomov, S.V.; Verpoest, I.; Witzel, V.; Drechsler, K.

    2006-01-01

    The paper addresses the experimental investigation of the unit cell architecture in a structurally stitched multilayer carbon-fibre preform. Each layer is a multiaxial multiply non-crimp fabric (NCF) knit with a non-structural stitching. The term “structural” presumes here that the stitching yarn do

  14. Building a Structural Model: Parameterization and Structurality

    Directory of Open Access Journals (Sweden)

    Michel Mouchart

    2016-04-01

    Full Text Available A specific concept of structural model is used as a background for discussing the structurality of its parameterization. Conditions for a structural model to be also causal are examined. Difficulties and pitfalls arising from the parameterization are analyzed. In particular, pitfalls when considering alternative parameterizations of a same model are shown to have lead to ungrounded conclusions in the literature. Discussions of observationally equivalent models related to different economic mechanisms are used to make clear the connection between an economically meaningful parameterization and an economically meaningful decomposition of a complex model. The design of economic policy is used for drawing some practical implications of the proposed analysis.

  15. Band structure of semiconductors

    CERN Document Server

    Tsidilkovski, I M

    2013-01-01

    Band Structure of Semiconductors provides a review of the theoretical and experimental methods of investigating band structure and an analysis of the results of the developments in this field. The book presents the problems, methods, and applications in the study of band structure. Topics on the computational methods of band structure; band structures of important semiconducting materials; behavior of an electron in a perturbed periodic field; effective masses and g-factors for the most commonly encountered band structures; and the treatment of cyclotron resonance, Shubnikov-de Haas oscillatio

  16. Structural system identification: Structural dynamics model validation

    Energy Technology Data Exchange (ETDEWEB)

    Red-Horse, J.R.

    1997-04-01

    Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

  17. Rheology of Structured Oils

    Science.gov (United States)

    Kelbaliev, G. I.; Rasulov, S. R.; Rzaev, A. G.; Mustafaeva, G. R.

    2017-07-01

    Rheological models of structured oils are proposed and compared with available experimental data on oils from different deposits. It is shown that structured oils can possess properties of Bingham and power-law non-Newtonian fluids.

  18. Structural Measures - Hospital

    Data.gov (United States)

    U.S. Department of Health & Human Services — A list of hospitals and the availability of structural measures at that hospital. A structural measure reflects the environment in which hospitals care for patients....

  19. Structural Static Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Structural testing is performed to verify the structural integrity of space flight and ground test hardware. Testing is also performed to verify the finite element...

  20. Growing Timber Structures

    DEFF Research Database (Denmark)

    Tamke, Martin; Evers, Henrik Leander; Stasiuk, David

    2013-01-01

    The contemporary design of timber structures has to answer questions concerning structural stability, production impact and energy implications in ever earlier stages. The interrelation of these levels creates a complexity that is difficult to resolve through contemporary linear parametric...

  1. Advanced structural inorganic chemistry

    CERN Document Server

    Li, Wai-Kee; Mak, Thomas C W

    2008-01-01

    An English edition of a textbook based on teaching at the final year undergraduate and graduate level. It presents structure and bonding, generalizations of structural trends, crystallographic data, as well as highlights from the recent literature.

  2. Antenna Structure Registrate

    Data.gov (United States)

    Department of Homeland Security — This file is an extract of the Antenna Structure Registrate (ASR). The ASR consists of antenna structures that are more than 60.96 meters (200 feet) in height or...

  3. Structural health monitoring for ship structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, Charles [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Angel, Marian [Los Alamos National Laboratory; Bement, Matthew [Los Alamos National Laboratory; Salvino, Liming [NSWC, CADEROCK

    2009-01-01

    Currently the Office of Naval Research is supporting the development of structural health monitoring (SHM) technology for U.S. Navy ship structures. This application is particularly challenging because of the physical size of these structures, the widely varying and often extreme operational and environmental conditions associated with these ships missions, lack of data from known damage conditions, limited sensing that was not designed specifically for SHM, and the management of the vast amounts of data that can be collected during a mission. This paper will first define a statistical pattern recognition paradigm for SHM by describing the four steps of (1) Operational Evaluation, (2) Data Acquisition, (3) Feature Extraction, and (4) Statistical Classification of Features as they apply to ship structures. Note that inherent in the last three steps of this process are additional tasks of data cleansing, compression, normalization and fusion. The presentation will discuss ship structure SHM challenges in the context of applying various SHM approaches to sea trials data measured on an aluminum multi-hull high-speed ship, the HSV-2 Swift. To conclude, the paper will discuss several outstanding issues that need to be addressed before SHM can make the transition from a research topic to actual field applications on ship structures and suggest approaches for addressing these issues.

  4. Fundamentals of structural dynamics

    CERN Document Server

    Craig, Roy R

    2006-01-01

    From theory and fundamentals to the latest advances in computational and experimental modal analysis, this is the definitive, updated reference on structural dynamics.This edition updates Professor Craig's classic introduction to structural dynamics, which has been an invaluable resource for practicing engineers and a textbook for undergraduate and graduate courses in vibrations and/or structural dynamics. Along with comprehensive coverage of structural dynamics fundamentals, finite-element-based computational methods, and dynamic testing methods, this Second Edition includes new and e

  5. Synchronously Deployable Truss Structures

    Science.gov (United States)

    Rhodes, M. D.; Hedgepeth, J. M.

    1986-01-01

    Structure lightweight, readily deployed, and has reliable joints. New truss concept, designated as "pac truss," developed. Features easy deployment without need for complex mechanisms. Structures of this type deployed in free flight by controlled release of stored energy in torsional springs at selected hinges located throughout structure. Double-folding technique used in beam model applicable to flat planar trusses, allowing structures of large expanse to fold into compact packages and be deployed for space-platform applications.

  6. Extended icosahedral structures

    CERN Document Server

    Jaric, Marko V

    1989-01-01

    Extended Icosahedral Structures discusses the concepts about crystal structures with extended icosahedral symmetry. This book is organized into six chapters that focus on actual modeling of extended icosahedral crystal structures. This text first presents a tiling approach to the modeling of icosahedral quasiperiodic crystals. It then describes the models for icosahedral alloys based on random connections between icosahedral units, with particular emphasis on diffraction properties. Other chapters examine the glassy structures with only icosahedral orientational order and the extent of tra

  7. HIV Structural Database

    Science.gov (United States)

    SRD 102 HIV Structural Database (Web, free access)   The HIV Protease Structural Database is an archive of experimentally determined 3-D structures of Human Immunodeficiency Virus 1 (HIV-1), Human Immunodeficiency Virus 2 (HIV-2) and Simian Immunodeficiency Virus (SIV) Proteases and their complexes with inhibitors or products of substrate cleavage.

  8. Structural Ceramics Database

    Science.gov (United States)

    SRD 30 NIST Structural Ceramics Database (Web, free access)   The NIST Structural Ceramics Database (WebSCD) provides evaluated materials property data for a wide range of advanced ceramics known variously as structural ceramics, engineering ceramics, and fine ceramics.

  9. Structural safety during construction

    NARCIS (Netherlands)

    Terwel, K.C.; Mud, M.; Frijters, A.

    2014-01-01

    Structural safety during construction is a main concern for the building industry. Collapses of temporary structures or incomplete permanent structures are a threat for the safety of persons. Based on data from Dutch Labour Inspectorate this study concluded that approximately 20% of the fatalities

  10. Programing Structural Synthesis System

    Science.gov (United States)

    Rogers, James L., Jr.

    1986-01-01

    Program aids research in analysis and optimization. Programing Structural Synthesis System (PROSSS2) developed to provide structural-synthesis capability by combining access to SPAR with CONMIN program and set of interface procedures. SPAR is large general-purpose finite-element structural-analysis program, and CONMIN is large general-purpose optimization program. PROSSS2 written in FORTRAN IV for batch execution.

  11. Structural Enhancement of Learning

    Science.gov (United States)

    Trumpower, David L.; Goldsmith, Timothy E.

    2004-01-01

    Structural learning aids, such as interactive overviews (IOs), have previously been shown to facilitate text comprehension and recall. In this study, we examined the effects of structural aids on learners' structural knowledge and their performance on a procedural transfer task. In Experiment 1, 90 college students were presented definitions of…

  12. Neutrality in bipolar structures

    DEFF Research Database (Denmark)

    Montero, Javier; Rodríguez, J. Tinguaro; Franco, Camilo

    2014-01-01

    In this paper, we want to stress that bipolar knowledge representation naturally allows a family of middle states which define as a consequence different kinds of bipolar structures. These bipolar structures are deeply related to the three types of bipolarity introduced by Dubois and Prade, but our...... approach offers a systematic explanation of how such bipolar structures appear and can be identified....

  13. Organizational Knowledge Management Structure

    Science.gov (United States)

    Walczak, Steven

    2005-01-01

    Purpose: To propose and evaluate a novel management structure that encourages knowledge sharing across an organization. Design/methodology/approach: The extant literature on the impact of organizational culture and its link to management structure is examined and used to develop a new knowledge sharing management structure. Roadblocks to…

  14. Hypermedia 1990 structured Hypertext tutorial

    Science.gov (United States)

    Johnson, J. Scott

    1990-01-01

    Hypermedia 1990 structured Hypertext tutorial is presented in the form of view-graphs. The following subject areas are covered: structured hypertext; analyzing hypertext documents for structure; designing structured hypertext documents; creating structured hypertext applications; structuring service and repair documents; maintaining structured hypertext documents; and structured hypertext conclusion.

  15. PRODUCT STRUCTURE DIGITAL MODEL

    Directory of Open Access Journals (Sweden)

    V.M. Sineglazov

    2005-02-01

    Full Text Available  Research results of representation of product structure made by means of CADDS5 computer-aided design (CAD system, Product Data Management Optegra (PDM system and Product Life Cycle Management Wind-chill system (PLM, are examined in this work. Analysis of structure component development and its storage in various systems is carried out. Algorithms of structure transformation required for correct representation of the structure are considered. Management analysis of electronic mockup presentation of the product structure is carried out for Windchill system.

  16. Shell-like structures

    CERN Document Server

    Altenbach, Holm

    2011-01-01

    In this volume, scientists and researchers from industry discuss the new trends in simulation and computing shell-like structures. The focus is put on the following problems: new theories (based on two-dimensional field equations but describing non-classical effects), new constitutive equations (for materials like sandwiches, foams, etc. and which can be combined with the two-dimensional shell equations), complex structures (folded, branching and/or self intersecting shell structures, etc.) and shell-like structures on different scales (for example: nano-tubes) or very thin structures (similar

  17. Basic structural dynamics

    CERN Document Server

    Anderson, James C

    2012-01-01

    A concise introduction to structural dynamics and earthquake engineering Basic Structural Dynamics serves as a fundamental introduction to the topic of structural dynamics. Covering single and multiple-degree-of-freedom systems while providing an introduction to earthquake engineering, the book keeps the coverage succinct and on topic at a level that is appropriate for undergraduate and graduate students. Through dozens of worked examples based on actual structures, it also introduces readers to MATLAB, a powerful software for solving both simple and complex structural d

  18. Materials and structures

    Science.gov (United States)

    Saito, Theodore T.; Langenbeck, Sharon L.; Al-Jamily, Ghanim; Arnold, Joe; Barbee, Troy; Coulter, Dan; Dolgin, Ben; Fichter, Buck; George, Patricia; Gorenstein, Paul

    1992-08-01

    Materials and structures technology covers a wide range of technical areas. Some of the most pertinent issues for the Astrotech 21 missions include dimensionally stable structural materials, advanced composites, dielectric coatings, optical metallic coatings for low scattered light applications, low scattered light surfaces, deployable and inflatable structures (including optical), support structures in 0-g and 1-g environments, cryogenic optics, optical blacks, contamination hardened surfaces, radiation hardened glasses and crystals, mono-metallic telescopes and instruments, and materials characterization. Some specific examples include low coefficients of thermal expansion (CTE) structures (0.01 ppm/K), lightweight thermally stable mirror materials, thermally stable optical assemblies, high reliability/accuracy (1 micron) deployable structures, and characterization of nanometer level behavior of materials/structures for interferometry concepts. Large filled-aperture concepts will require materials with CTE's of 10(exp 9) at 80 K, anti-contamination coatings, deployable and erectable structures, composite materials with CTE's less than 0.01 ppm/K and thermal hysteresis, 0.001 ppm/K. Gravitational detection systems such as LAGOS will require rigid/deployable structures, dimensionally stable components, lightweight materials with low conductivity, and high stability optics. The Materials and Structures panel addressed these issues and the relevance of the Astrotech 21 mission requirements by dividing materials and structures technology into five categories. These categories, the necessary development, and applicable mission/program development phasing are summarized. For each of these areas, technology assessments were made and development plans were defined.

  19. Exotic cluster structures on

    CERN Document Server

    Gekhtman, M; Vainshtein, A

    2017-01-01

    This is the second paper in the series of papers dedicated to the study of natural cluster structures in the rings of regular functions on simple complex Lie groups and Poisson-Lie structures compatible with these cluster structures. According to our main conjecture, each class in the Belavin-Drinfeld classification of Poisson-Lie structures on \\mathcal{G} corresponds to a cluster structure in \\mathcal{O}(\\mathcal{G}). The authors have shown before that this conjecture holds for any \\mathcal{G} in the case of the standard Poisson-Lie structure and for all Belavin-Drinfeld classes in SL_n, n<5. In this paper the authors establish it for the Cremmer-Gervais Poisson-Lie structure on SL_n, which is the least similar to the standard one.

  20. Structural realism beyond physics.

    Science.gov (United States)

    Tulodziecki, Dana

    2016-10-01

    The main purpose of this paper is to test structural realism against (one example from) the historical record. I begin by laying out an existing challenge to structural realism - that of providing an example of a theory exhibiting successful structures that were abandoned - and show that this challenge can be met by the miasma theory of disease. However, rather than concluding that this is an outright counterexample to structural realism, I use this case to show why it is that structural realism, in its current form, has trouble dealing with theories outside physics. I end by making some concrete suggestions for structural realists to pursue if, indeed, they are serious about extending structural realism to other domains.

  1. Reducts of Ramsey structures

    CERN Document Server

    Bodirsky, Manuel

    2011-01-01

    One way of studying a relational structure is to investigate functions which are related to that structure and which leave certain aspects of the structure invariant. Examples are the automorphism group, the self-embedding monoid, the endomorphism monoid, or the polymorphism clone of a structure. Such functions can be particularly well understood when the relational structure is countably infinite and has a first-order definition in another relational structure which has a finite language, is totally ordered and homogeneous, and has the Ramsey property. This is because in this situation, Ramsey theory provides the combinatorial tool for analyzing these functions -- in a certain sense, it allows to represent such functions by functions on finite sets. This is a survey of results in model theory and theoretical computer science obtained recently by the authors in this context. In model theory, we approach the problem of classifying the reducts of countably infinite ordered homogeneous Ramsey structures in a fin...

  2. Robustness of Structures

    DEFF Research Database (Denmark)

    Faber, M.H.; Vrouwenvelder, A.C.W.M.; Sørensen, John Dalsgaard

    2011-01-01

    In 2005, the Joint Committee on Structural Safety (JCSS) together with Working Commission (WC) 1 of the International Association of Bridge and Structural Engineering (IABSE) organized a workshop on robustness of structures. Two important decisions resulted from this workshop, namely the developm......In 2005, the Joint Committee on Structural Safety (JCSS) together with Working Commission (WC) 1 of the International Association of Bridge and Structural Engineering (IABSE) organized a workshop on robustness of structures. Two important decisions resulted from this workshop, namely...... the development of a joint European project on structural robustness under the COST (European Cooperation in Science and Technology) programme and the decision to develop a more elaborate document on structural robustness in collaboration between experts from the JCSS and the IABSE. Accordingly, a project titled...... ‘COST TU0601: Robustness of Structures’ was initiated in February 2007, aiming to provide a platform for exchanging and promoting research in the area of structural robustness and to provide a basic framework, together with methods, strategies and guidelines enhancing robustness of structures...

  3. Structure - Riverine Flow Structure (Dike/Wingdam)

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — A natural or man-made flow (or sediment) control structure in a water course or water body such as a dike or weir. This feature should not be used to model a levee....

  4. Exponential Dowling structures

    CERN Document Server

    Ehrenborg, Richard

    2010-01-01

    The notion of exponential Dowling structures is introduced, generalizing Stanley's original theory of exponential structures. Enumerative theory is developed to determine the M\\"obius function of exponential Dowling structures, including a restriction of these structures to elements whose types satisfy a semigroup condition. Stanley's study of permutations associated with exponential structures leads to a similar vein of study for exponential Dowling structures. In particular, for the extended r-divisible partition lattice we show the M\\"obius function is, up to a sign, the number of permutations in the symmetric group on rn+k elements having descent set {r, 2r, ..., nr}. Using Wachs' original EL-labeling of the r-divisible partition lattice, the extended r-divisible partition lattice is shown to be EL-shellable.

  5. Origami - Folded Plate Structures

    OpenAIRE

    Buri, Hans Ulrich

    2010-01-01

    This research investigates new methods of designing folded plate structures that can be built with cross-laminated timber panels. Folded plate structures are attractive to both architects and engineers for their structural, spatial, and plastic qualities. Thin surfaces can be stiffened by a series of folds, and thus not only cover space, but also act as load bearing elements. The variation of light and shadow along the folded faces emphasizes the plas...

  6. Catalytic distillation structure

    Science.gov (United States)

    Smith, L.A. Jr.

    1984-04-17

    Catalytic distillation structure is described for use in reaction distillation columns, and provides reaction sites and distillation structure consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and is present with the catalyst component in an amount such that the catalytic distillation structure consists of at least 10 volume % open space. 10 figs.

  7. Advance in structural bioinformatics

    CERN Document Server

    Wei, Dongqing; Zhao, Tangzhen; Dai, Hao

    2014-01-01

    This text examines in detail mathematical and physical modeling, computational methods and systems for obtaining and analyzing biological structures, using pioneering research cases as examples. As such, it emphasizes programming and problem-solving skills. It provides information on structure bioinformatics at various levels, with individual chapters covering introductory to advanced aspects, from fundamental methods and guidelines on acquiring and analyzing genomics and proteomics sequences, the structures of protein, DNA and RNA, to the basics of physical simulations and methods for conform

  8. Structure of Human Adenovirus

    OpenAIRE

    Nemerow, Glen R.; Phoebe L Stewart; Reddy, Vijay S.

    2012-01-01

    A detailed structural analysis of the entire human adenovirus capsid has been stymied by the complexity and size of this 150 MDa macromolecular complex. Over the past 10 years, the steady improvements in viral genome manipulation concomitant with advances in crystallographic techniques and data processing software has allowed structure determination of this virus by X-ray diffraction at 3.5 Å resolution. The virus structure revealed the location, folds, and interactions of major and minor (ce...

  9. Reforming Organizational Structures

    OpenAIRE

    Van de Walle, Steven

    2016-01-01

    textabstractPublic sectors have undergone major transformations. Public sector reform touches upon the core building blocks of the public sector: organizational structures, people and finances. These are objects of reform. This chapter presents and discusses a set of major transformations with regard to organizational structures. It provides readers a fairly comprehensive overview of the key reforms that have taken place in Western public sectors. Structural reforms in the public sector show ...

  10. Auxetic materials and structures

    CERN Document Server

    Lim, Teik-Cheng

    2015-01-01

    This book describes the fundamentals of the mechanics and design of auxetic solids and structures, which possess a negative Poisson’s ratio. It will benefit two groups of readers: (a) industry practitioners, such as product and structural designers, who need to control mechanical stress distributions using auxetic materials, and (b) academic researchers and students who intend to produce structures with unique mechanical and other physical properties using auxetic materials.

  11. Structural elements design manual

    CERN Document Server

    Draycott, Trevor

    2012-01-01

    Gives clear explanations of the logical design sequence for structural elements. The Structural Engineer says: `The book explains, in simple terms, and with many examples, Code of Practice methods for sizing structural sections in timber, concrete,masonry and steel. It is the combination into one book of section sizing methods in each of these materials that makes this text so useful....Students will find this an essential support text to the Codes of Practice in their study of element sizing'.

  12. Organisational structure of Enterprise

    OpenAIRE

    Varenytsya, Maryan

    2015-01-01

    The purpose of the bachelor final work is to identify effective organizational management structure, as well offer advice company branch of JSC "Rostelecom" for the improvement of organizational structure of management. It examines the relevance of the study, defined goals, objectives and methods of research, a review of the literature. This thesis contains information on the main causes of changes in the organizational structure of the enterprise management, the design of the organizational ...

  13. Valency and molecular structure

    CERN Document Server

    Cartmell, E

    1977-01-01

    Valency and Molecular Structure, Fourth Edition provides a comprehensive historical background and experimental foundations of theories and methods relating to valency and molecular structures. In this edition, the chapter on Bohr theory has been removed while some sections, such as structures of crystalline solids, have been expanded. Details of structures have also been revised and extended using the best available values for bond lengths and bond angles. Recent developments are mostly noted in the chapter on complex compounds, while a new chapter has been added to serve as an introduction t

  14. Linguistic Structure Prediction

    CERN Document Server

    Smith, Noah A

    2011-01-01

    A major part of natural language processing now depends on the use of text data to build linguistic analyzers. We consider statistical, computational approaches to modeling linguistic structure. We seek to unify across many approaches and many kinds of linguistic structures. Assuming a basic understanding of natural language processing and/or machine learning, we seek to bridge the gap between the two fields. Approaches to decoding (i.e., carrying out linguistic structure prediction) and supervised and unsupervised learning of models that predict discrete structures as outputs are the focus. W

  15. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

  16. Structural Dynamics Laboratory (SDL)

    Data.gov (United States)

    Federal Laboratory Consortium — Structural dynamic testing is performed to verify the survivability of a component or assembly when exposed to vibration stress screening, or a controlled simulation...

  17. Machine tool structures

    CERN Document Server

    Koenigsberger, F

    1970-01-01

    Machine Tool Structures, Volume 1 deals with fundamental theories and calculation methods for machine tool structures. Experimental investigations into stiffness are discussed, along with the application of the results to the design of machine tool structures. Topics covered range from static and dynamic stiffness to chatter in metal cutting, stability in machine tools, and deformations of machine tool structures. This volume is divided into three sections and opens with a discussion on stiffness specifications and the effect of stiffness on the behavior of the machine under forced vibration c

  18. Flexible Volumetric Structure

    Science.gov (United States)

    Cagle, Christopher M. (Inventor); Schlecht, Robin W. (Inventor)

    2014-01-01

    A flexible volumetric structure has a first spring that defines a three-dimensional volume and includes a serpentine structure elongatable and compressible along a length thereof. A second spring is coupled to at least one outboard edge region of the first spring. The second spring is a sheet-like structure capable of elongation along an in-plane dimension thereof. The second spring is oriented such that its in-plane dimension is aligned with the length of the first spring's serpentine structure.

  19. Laboratory for Structural Acoustics

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where acoustic radiation, scattering, and surface vibration measurements of fluid-loaded and non-fluid-loaded structures are...

  20. Deployable Soft Composite Structures

    Science.gov (United States)

    Wang, Wei; Rodrigue, Hugo; Ahn, Sung-Hoon

    2016-02-01

    Deployable structure composed of smart materials based actuators can reconcile its inherently conflicting requirements of low mass, good shape adaptability, and high load-bearing capability. This work describes the fabrication of deployable structures using smart soft composite actuators combining a soft matrix with variable stiffness properties and hinge-like movement through a rigid skeleton. The hinge actuator has the advantage of being simple to fabricate, inexpensive, lightweight and simple to actuate. This basic actuator can then be used to form modules capable of different types of deformations, which can then be assembled into deployable structures. The design of deployable structures is based on three principles: design of basic hinge actuators, assembly of modules and assembly of modules into large-scale deployable structures. Various deployable structures such as a segmented triangular mast, a planar structure comprised of single-loop hexagonal modules and a ring structure comprised of single-loop quadrilateral modules were designed and fabricated to verify this approach. Finally, a prototype for a deployable mirror was developed by attaching a foldable reflective membrane to the designed ring structure and its functionality was tested by using it to reflect sunlight onto to a small-scale solar panel.

  1. Deployable Soft Composite Structures.

    Science.gov (United States)

    Wang, Wei; Rodrigue, Hugo; Ahn, Sung-Hoon

    2016-02-19

    Deployable structure composed of smart materials based actuators can reconcile its inherently conflicting requirements of low mass, good shape adaptability, and high load-bearing capability. This work describes the fabrication of deployable structures using smart soft composite actuators combining a soft matrix with variable stiffness properties and hinge-like movement through a rigid skeleton. The hinge actuator has the advantage of being simple to fabricate, inexpensive, lightweight and simple to actuate. This basic actuator can then be used to form modules capable of different types of deformations, which can then be assembled into deployable structures. The design of deployable structures is based on three principles: design of basic hinge actuators, assembly of modules and assembly of modules into large-scale deployable structures. Various deployable structures such as a segmented triangular mast, a planar structure comprised of single-loop hexagonal modules and a ring structure comprised of single-loop quadrilateral modules were designed and fabricated to verify this approach. Finally, a prototype for a deployable mirror was developed by attaching a foldable reflective membrane to the designed ring structure and its functionality was tested by using it to reflect sunlight onto to a small-scale solar panel.

  2. Bioinspired structural materials

    Science.gov (United States)

    Wegst, Ulrike G. K.; Bai, Hao; Saiz, Eduardo; Tomsia, Antoni P.; Ritchie, Robert O.

    2015-01-01

    Natural structural materials are built at ambient temperature from a fairly limited selection of components. They usually comprise hard and soft phases arranged in complex hierarchical architectures, with characteristic dimensions spanning from the nanoscale to the macroscale. The resulting materials are lightweight and often display unique combinations of strength and toughness, but have proven difficult to mimic synthetically. Here, we review the common design motifs of a range of natural structural materials, and discuss the difficulties associated with the design and fabrication of synthetic structures that mimic the structural and mechanical characteristics of their natural counterparts.

  3. Nuclear structure theory

    CERN Document Server

    Irvine, J M

    1972-01-01

    Nuclear Structure Theory provides a guide to nuclear structure theory. The book is comprised of 23 chapters that are organized into four parts; each part covers an aspect of nuclear structure theory. In the first part, the text discusses the experimentally observed phenomena, which nuclear structure theories need to look into and detail the information that supports those theories. The second part of the book deals with the phenomenological nucleon-nucleon potentials derived from phase shift analysis of nucleon-nucleon scattering. Part III talks about the phenomenological parameters used to de

  4. Roadmap on structured light

    Science.gov (United States)

    Rubinsztein-Dunlop, Halina; Forbes, Andrew; Berry, M. V.; Dennis, M. R.; Andrews, David L.; Mansuripur, Masud; Denz, Cornelia; Alpmann, Christina; Banzer, Peter; Bauer, Thomas; Karimi, Ebrahim; Marrucci, Lorenzo; Padgett, Miles; Ritsch-Marte, Monika; Litchinitser, Natalia M.; Bigelow, Nicholas P.; Rosales-Guzmán, C.; Belmonte, A.; Torres, J. P.; Neely, Tyler W.; Baker, Mark; Gordon, Reuven; Stilgoe, Alexander B.; Romero, Jacquiline; White, Andrew G.; Fickler, Robert; Willner, Alan E.; Xie, Guodong; McMorran, Benjamin; Weiner, Andrew M.

    2017-01-01

    Structured light refers to the generation and application of custom light fields. As the tools and technology to create and detect structured light have evolved, steadily the applications have begun to emerge. This roadmap touches on the key fields within structured light from the perspective of experts in those areas, providing insight into the current state and the challenges their respective fields face. Collectively the roadmap outlines the venerable nature of structured light research and the exciting prospects for the future that are yet to be realized.

  5. Probabilistic conditional independence structures

    CERN Document Server

    Studeny, Milan

    2005-01-01

    Probabilistic Conditional Independence Structures provides the mathematical description of probabilistic conditional independence structures; the author uses non-graphical methods of their description, and takes an algebraic approach.The monograph presents the methods of structural imsets and supermodular functions, and deals with independence implication and equivalence of structural imsets.Motivation, mathematical foundations and areas of application are included, and a rough overview of graphical methods is also given.In particular, the author has been careful to use suitable terminology, and presents the work so that it will be understood by both statisticians, and by researchers in artificial intelligence.The necessary elementary mathematical notions are recalled in an appendix.

  6. Structural patterns in nature

    DEFF Research Database (Denmark)

    Wester, Ture

    2004-01-01

    It seems that some very basic randomly produced geometric/topological patterns are commonly found in Nature and have often very distinctive structural qualities. In nature we find the same pattern in all scales from the universe to molecules, from solar systems to packing of cells, from glaciers...... to sea shells, from river systems to trees etc. Sometimes this seeming archetypical morphology involve structural action and sometimes not - but the fact that it often posses efficient structural action opens a tool for evaluation and analyses of structures in nature and at the same time might...

  7. Stable umbral chromospheric structures

    Science.gov (United States)

    Henriques, V. M. J.; Scullion, E.; Mathioudakis, M.; Kiselman, D.; Gallagher, P. T.; Keenan, F. P.

    2015-02-01

    Aims: We seek to understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable structures, and examine their relationship with observables in the H-alpha line. Methods: Filtergrams in the core of the Ca II H and H-alpha lines as observed with the Swedish 1-m Solar Telescope are employed. We utilise a technique that creates composite images and tracks the flash propagation horizontally. Results: We find 0.̋15 wide horizontal structures, in all of the three target sunspots, for every flash where the seeing is moderate to good. Discrete dark structures are identified that are stable for at least two umbral flashes, as well as systems of structures that live for up to 24 min. We find cases of extremely extended structures with similar stability, with one such structure showing an extent of 5''. Some of these structures have a correspondence in H-alpha, but we were unable to find a one-to-one correspondence for every occurrence. If the dark streaks are formed at the same heights as umbral flashes, there are systems of structures with strong departures from the vertical for all three analysed sunspots. Conclusions: Long-lived Ca II H filamentary horizontal structures are a common and likely ever-present feature in the umbra of sunspots. If the magnetic field in the chromosphere of the umbra is indeed aligned with the structures, then the present theoretical understanding of the typical umbra needs to be revisited. Movies associated to Figs. 3 and 4 are available in electronic form at http://www.aanda.org

  8. Organisational Structure & Change

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2006

    2006-01-01

    Structural change is seen as a way to meet the challenges of the future that face many organisations. While some writers agree that broad-ranging structural change may not always transform an organisation or enhance its performance, others claim that innovation will be a major source of competitive advantage to organisations, particularly when…

  9. The Structure of Reciprocity

    Science.gov (United States)

    Molm, Linda D.

    2010-01-01

    Reciprocity is one of the defining features of social exchange and social life, yet exchange theorists have tended to take it for granted. Drawing on work from a decade-long theoretical research program, I argue that reciprocity is structured and variable across different forms of exchange, that these variations in the structure of reciprocity…

  10. Tapered structure construction

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Eric D.; Takata, Rosalind K.; Slocum, Alexander H.; Nayfeh, Samir A.

    2016-04-05

    Feeding stock used to form a tapered structure into a curving device such that each point on the stock undergoes rotational motion about a peak location of the tapered structure; and the stock meets a predecessor portion of stock along one or more adjacent edges.

  11. Wave scour around structures

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Fredsøe, Jørgen

    1999-01-01

    This review (of scour around marine structures) is organized in seven main sections: Basic concepts; Tunnel erosion; Two- and three-dimensional scour around pipelines; Scour around piles (slender bodies), including pile groups; Scour around complex structures; Scour around large, vertical cylinde......; and Scour around breakwaters (vertical-wall breakwaters and rubble-mound breakwaters)....

  12. Neutrinos and nucleon structure

    CERN Document Server

    Sehgal, L M

    1979-01-01

    The study of neutrino interactions in matter is yielding a wealth of information on the form factors and structure functions of the nucleon. These data allow tests of models of nucleon structure and of dynamical theories of quarks and gluons. The author attempts a critical appraisal of recent facts and their impact on our theoretical understanding. (35 refs).

  13. The Cambridge Structural Database.

    Science.gov (United States)

    Groom, Colin R; Bruno, Ian J; Lightfoot, Matthew P; Ward, Suzanna C

    2016-04-01

    The Cambridge Structural Database (CSD) contains a complete record of all published organic and metal-organic small-molecule crystal structures. The database has been in operation for over 50 years and continues to be the primary means of sharing structural chemistry data and knowledge across disciplines. As well as structures that are made public to support scientific articles, it includes many structures published directly as CSD Communications. All structures are processed both computationally and by expert structural chemistry editors prior to entering the database. A key component of this processing is the reliable association of the chemical identity of the structure studied with the experimental data. This important step helps ensure that data is widely discoverable and readily reusable. Content is further enriched through selective inclusion of additional experimental data. Entries are available to anyone through free CSD community web services. Linking services developed and maintained by the CCDC, combined with the use of standard identifiers, facilitate discovery from other resources. Data can also be accessed through CCDC and third party software applications and through an application programming interface.

  14. Periodic truss structures

    Science.gov (United States)

    Zok, Frank W.; Latture, Ryan M.; Begley, Matthew R.

    2016-11-01

    Despite the recognition of the enormous potential of periodic trusses for use in a broad range of technologies, there are no widely-accepted descriptors of their structure. The terminology has been based loosely either on geometry of polyhedra or of point lattices: neither of which, on its own, has an appropriate structure to fully define periodic trusses. The present article lays out a system for classification of truss structure types. The system employs concepts from crystallography and geometry to describe nodal locations and connectivity of struts. Through a series of illustrative examples of progressively increasing complexity, a rational taxonomy of truss structure is developed. Its conceptual evolution begins with elementary cubic trusses, increasing in complexity with non-cubic and compound trusses as well as supertrusses, and, finally, with complex trusses. The conventions and terminology adopted to define truss structure yield concise yet unambiguous descriptions of structure types and of specific (finite) trusses. The utility of the taxonomy is demonstrated by bringing into alignment a disparate set of ad hoc and incomplete truss designations previously employed in a broad range of science and engineering fields. Additionally, the merits of a particular compound truss (comprising two interpenetrating elementary trusses) is shown to be superior to the octet truss for applications requiring high stiffness and elastic isotropy. By systematically stepping through and analyzing the finite number of structure types identified through the present classification system, optimal structures for prescribed mechanical and functional requirements are expected to be ascertained in an expeditious manner.

  15. Structures of Mn clusters

    Indian Academy of Sciences (India)

    Tina M Briere; Marcel H F Sluiter; Vijay Kumar; Yoshiyuki Kawazoe

    2003-01-01

    The geometries of several Mn clusters in the size range Mn13–Mn23 are studied via the generalized gradient approximation to density functional theory. For the 13- and 19-atom clusters, the icosahedral structures are found to be most stable, while for the 15-atom cluster, the bcc structure is more favoured. The clusters show ferrimagnetic spin configurations.

  16. Lightweight Composite Intertank Structure

    Science.gov (United States)

    Mehle, Greg V.

    1995-01-01

    Report presents results of study for proposed lightweight composite material alternative to present semimonocoque aluminum intertank structure for advanced launch vehicles. Proposed structure integrated assembly of sandwich panels made of laminated epoxy-matrix/carbon-fiber skins, and aluminum honeycomb core.

  17. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly.......Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

  18. Magnetic Nano-structures

    Institute of Scientific and Technical Information of China (English)

    姚永德

    2004-01-01

    Fabrication of magnetic nano-structures with dots array and wires has been paid attention recently due to the application of high-density magnetic recording. In this study, we fabricated the magnetic dots array and wires through several ways that ensure the arrangement of magnetic dots and wires to be the structures we designed. Their magnetic properties are studied experimentally.

  19. Hierarchical Porous Structures

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-07

    Materials Design is often at the forefront of technological innovation. While there has always been a push to generate increasingly low density materials, such as aero or hydrogels, more recently the idea of bicontinuous structures has gone more into play. This review will cover some of the methods and applications for generating both porous, and hierarchically porous structures.

  20. Fire exposed aluminium structures

    NARCIS (Netherlands)

    Maljaars, J.; Fellinger, J.H.H.; Soetens, F.

    2006-01-01

    Material properties and mechanical response models for fire design of steel structures are based on extensive research and experience. Contrarily, the behaviour of aluminium load bearing structures exposed to fire is relatively unexplored. This article gives an overview of physical and mechanical pr

  1. Solution structure of (+)-discodermolide.

    Science.gov (United States)

    Smith, A B; LaMarche, M J; Falcone-Hindley, M

    2001-03-01

    [structure: see text]. The solution structure of (+)-discodermolide (1) has been determined via 1- and 2-D NMR techniques in conjunction with Monte Carlo conformational analysis. Taken together, the results demonstrate that in solution (+)-discodermolide occupies a helical conformation remarkably similar to the solid state conformation.

  2. Hedging structured concepts

    NARCIS (Netherlands)

    Koolen, W.M.; Warmuth, M.K.; Kivinen, J.; Kalai, A.T.; Mohri, M.

    2010-01-01

    We develop an online algorithm called Component Hedge for learning structured concept classes when the loss of a structured concept sums over its components. Example classes include paths through a graph (composed of edges) and partial permutations (composed of assignments). The algorithm maintains

  3. Describing migration spatial structure

    NARCIS (Netherlands)

    Rogers, A; Willekens, F; Little, J; Raymer, J

    The age structure of a population is a fundamental concept in demography and is generally depicted in the form of an age pyramid. The spatial structure of an interregional system of origin-destination-specific migration streams is, however, a notion lacking a widely accepted definition. We offer a

  4. Structure sensitivity in adsorption

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Nielsen, Ole Holm; Nørskov, Jens Kehlet

    1997-01-01

    The structure sensitivity of CO adsorption on different flat, stepped, kinked and reconstructed Pt surfaces is studied using large-scale density-functional calculations. We find an extremely strong structure sensitivity in the adsorption energy with variations up to 1 eV (or 100%) from one...

  5. Shipping Industry Structure

    NARCIS (Netherlands)

    Wijnolst, N.; Waals, F.

    1999-01-01

    Understanding Shipping Management requires a thorough understanding of the Shipping Industry Structure. This book provides this knowledge base and should be seen in conjunction with two other books: Shipping and Design Innovation in Shipping. Shipping Industry Structure was intended as the first par

  6. Wave scour around structures

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Fredsøe, Jørgen

    1999-01-01

    This review (of scour around marine structures) is organized in seven main sections: Basic concepts; Tunnel erosion; Two- and three-dimensional scour around pipelines; Scour around piles (slender bodies), including pile groups; Scour around complex structures; Scour around large, vertical cylinders......; and Scour around breakwaters (vertical-wall breakwaters and rubble-mound breakwaters)....

  7. Piaget's Structural Developmental Psychology.

    Science.gov (United States)

    Broughton, John M.

    1981-01-01

    Piaget's theory is identified as a branch of structuralism concerned with the concept of truth, in distinction from French structuralism, which is focused on meaning. The two branches are compared and contrasted, and relations between logic and language are explored. Similarities and differences in the theories of Piaget, Levi-Strauss, and Chomsky…

  8. Robustness of structures

    DEFF Research Database (Denmark)

    Vrouwenvelder, T.; Sørensen, John Dalsgaard

    2009-01-01

    robustness is still an issue of controversy and poses difficulties in regard to interpretation as well as regulation. Typically modern structural design codes require that ‘the consequence of damages to structures should not be disproportional to the causes of the damages'. However, despite the importance...

  9. Structural Crashworthiness and Failure

    Science.gov (United States)

    1993-04-16

    structures en materiaux composite. VDI-Bericht Nr 369, 1980. 46. Kirsch, P. A. & Jahnle, H. A., Energy absorption of glass-polyester structures. SAE...materials in the automotive industry. They built two cabins, one equipped with front and rear suspension , steering assembly, rear engine, seats, outer skin

  10. Generalized holomorphic structures

    Science.gov (United States)

    Wang, Yicao

    2014-12-01

    We define the notion of generalized holomorphic principal bundles and establish that their associated vector bundles of holomorphic representations are generalized holomorphic vector bundles defined by M. Gualtieri. Motivated by our definition, several examples of generalized holomorphic structures are constructed. A reduction theorem of generalized holomorphic structures is also included.

  11. Shipping Industry Structure

    NARCIS (Netherlands)

    Wijnolst, N.; Waals, F.

    1999-01-01

    Understanding Shipping Management requires a thorough understanding of the Shipping Industry Structure. This book provides this knowledge base and should be seen in conjunction with two other books: Shipping and Design Innovation in Shipping. Shipping Industry Structure was intended as the first par

  12. Shipping Industry Structure

    NARCIS (Netherlands)

    Wijnolst, N.; Waals, F.

    1999-01-01

    Understanding Shipping Management requires a thorough understanding of the Shipping Industry Structure. This book provides this knowledge base and should be seen in conjunction with two other books: Shipping and Design Innovation in Shipping. Shipping Industry Structure was intended as the first

  13. Dynamic term structure models

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller; Meldrum, Andrew

    This paper studies whether dynamic term structure models for US nominal bond yields should enforce the zero lower bound by a quadratic policy rate or a shadow rate specification. We address the question by estimating quadratic term structure models (QTSMs) and shadow rate models with at most four...

  14. Buckling of Ship Structures

    CERN Document Server

    Shama, Mohamed

    2013-01-01

    Buckling of Ship Structures presents a comprehensive analysis of the buckling problem of ship structural members. A full analysis of the various types of loadings and stresses imposed on ship plating and primary and secondary structural members is given. The main causes and consequences of the buckling mode of failure of ship structure and the methods commonly used to control buckling failure are clarified. This book contains the main equations required to determine the critical buckling stresses for both ship plating and the primary and secondary stiffening structural members. The critical buckling stresses are given for ship plating subjected to the induced various types of loadings and having the most common boundary conditions encountered in ship structures.  The text bridges the gap existing in most books covering the subject of buckling of ship structures in the classical analytical format, by putting the emphasis on the practical methods required to ensure safety against buckling of ship structur...

  15. Product Structuring, an overview

    DEFF Research Database (Denmark)

    Tichem, Marcel; Storm, Ton; Andreasen, Mogens Myrup;

    1997-01-01

    This paper presents the highlights of two WDK Workshops on Product Structuring. Product structuring plays an important role in creating products which have good functional and life-cycle related properties, in design process management, and in several other company functions like production control...

  16. Fire exposed aluminium structures

    NARCIS (Netherlands)

    Maljaars, J.; Fellinger, J.H.H.; Soetens, F.

    2006-01-01

    Material properties and mechanical response models for fire design of steel structures are based on extensive research and experience. Contrarily, the behaviour of aluminium load bearing structures exposed to fire is relatively unexplored. This article gives an overview of physical and mechanical

  17. Describing migration spatial structure

    NARCIS (Netherlands)

    Rogers, A; Willekens, F; Little, J; Raymer, J

    2002-01-01

    The age structure of a population is a fundamental concept in demography and is generally depicted in the form of an age pyramid. The spatial structure of an interregional system of origin-destination-specific migration streams is, however, a notion lacking a widely accepted definition. We offer a d

  18. Cosmic structure formation

    Science.gov (United States)

    Bertschinger, Edumund

    1994-01-01

    This article reviews the prevailing paradigm for how galaxies and larger structures formed in the universe: gravitational instability. Basic observational facts are summarized to motivate the standard cosmological framework underlying most detailed investigations of structure formation. The observed univers approaches spatial uniformity on scales larger than about 10(exp 26) cm. On these scales gravitational dynamics is almost linear and therefore relatively easy to relate to observations of large-scale structure. On smaller scales cosmic structure is complicated not only by nonlinear gravitational clustering but also by nonlinear nongravitational gas dynamical processes. The complexity of these phenomena makes galaxy formation one of the grand challenge problems of the physical sciences. No fully satisfactory theory can presently account in detail for the observed cosmic structure. However, as this article summarizes, significant progress has been made during the last few years.

  19. Iconicity as structure mapping.

    Science.gov (United States)

    Emmorey, Karen

    2014-09-19

    Linguistic and psycholinguistic evidence is presented to support the use of structure-mapping theory as a framework for understanding effects of iconicity on sign language grammar and processing. The existence of structured mappings between phonological form and semantic mental representations has been shown to explain the nature of metaphor and pronominal anaphora in sign languages. With respect to processing, it is argued that psycholinguistic effects of iconicity may only be observed when the task specifically taps into such structured mappings. In addition, language acquisition effects may only be observed when the relevant cognitive abilities are in place (e.g. the ability to make structural comparisons) and when the relevant conceptual knowledge has been acquired (i.e. information key to processing the iconic mapping). Finally, it is suggested that iconicity is better understood as a structured mapping between two mental representations than as a link between linguistic form and human experience.

  20. Nonlinear dynamics of structures

    CERN Document Server

    Oller, Sergio

    2014-01-01

    This book lays the foundation of knowledge that will allow a better understanding of nonlinear phenomena that occur in structural dynamics.   This work is intended for graduate engineering students who want to expand their knowledge on the dynamic behavior of structures, specifically in the nonlinear field, by presenting the basis of dynamic balance in non‐linear behavior structures due to the material and kinematics mechanical effects.   Particularly, this publication shows the solution of the equation of dynamic equilibrium for structure with nonlinear time‐independent materials (plasticity, damage and frequencies evolution), as well as those time dependent non‐linear behavior materials (viscoelasticity and viscoplasticity). The convergence conditions for the non‐linear dynamic structure solution  are studied, and the theoretical concepts and its programming algorithms are presented.  

  1. Regularized Structural Equation Modeling.

    Science.gov (United States)

    Jacobucci, Ross; Grimm, Kevin J; McArdle, John J

    A new method is proposed that extends the use of regularization in both lasso and ridge regression to structural equation models. The method is termed regularized structural equation modeling (RegSEM). RegSEM penalizes specific parameters in structural equation models, with the goal of creating easier to understand and simpler models. Although regularization has gained wide adoption in regression, very little has transferred to models with latent variables. By adding penalties to specific parameters in a structural equation model, researchers have a high level of flexibility in reducing model complexity, overcoming poor fitting models, and the creation of models that are more likely to generalize to new samples. The proposed method was evaluated through a simulation study, two illustrative examples involving a measurement model, and one empirical example involving the structural part of the model to demonstrate RegSEM's utility.

  2. Socio-Technical Structure

    DEFF Research Database (Denmark)

    Rose, Jeremy; Lindgren, Rikard; Henfridsson, Ole

    2004-01-01

    a reference discipline in its own right (in other words a theory exporter), this paper offers an example of integrative theory development. Instead of adapting a theory from another discipline or building a theory from empirical data, we examine the structure concept in some of its various theoretical...... adaptations in IS and try to integrate them to produce theory that focuses on IS concerns whilst resolving some of the major areas of contention. Both social and technological versions of structure are investigated through three theoretical IS perspectives drawn from different reference disciplines. The first...... perspective relates to social theories (principally structuration theory), the second to linguistic theories (principally the structural linguistics of Chomsky), and the last to science studies (principally actor-network theory). The objective is to study areas of agreement and contention around the structure...

  3. Optoelectronic Mounting Structure

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Gene R. (Albuquerque, NM); Armendariz, Marcelino G. (Albuquerque, NM); Baca, Johnny R. F. (Albuquerque, NM); Bryan, Robert P. (Albuquerque, NM); Carson, Richard F. (Albuquerque, NM); Chu, Dahwey (Albuquerque, NM); Duckett, III, Edwin B. (Albuquerque, NM); McCormick, Frederick B. (Albuquerque, NM); Peterson, David W. (Sandia Park, NM); Peterson, Gary D. (Albuquerque, NM); Reber, Cathleen A. (Corrales, NM); Reysen, Bill H. (Lafayette, CO)

    2004-10-05

    An optoelectronic mounting structure is provided that may be used in conjunction with an optical transmitter, receiver or transceiver module. The mounting structure may be a flexible printed circuit board. Thermal vias or heat pipes in the head region may transmit heat from the mounting structure to the heat spreader. The heat spreader may provide mechanical rigidity or stiffness to the heat region. In another embodiment, an electrical contact and ground plane may pass along a surface of the head region so as to provide an electrical contact path to the optoelectronic devices and limit electromagnetic interference. In yet another embodiment, a window may be formed in the head region of the mounting structure so as to provide access to the heat spreader. Optoelectronic devices may be adapted to the heat spreader in such a manner that the devices are accessible through the window in the mounting structure.

  4. On Granular Knowledge Structures

    CERN Document Server

    Zeng, Yi

    2008-01-01

    Knowledge plays a central role in human and artificial intelligence. One of the key characteristics of knowledge is its structured organization. Knowledge can be and should be presented in multiple levels and multiple views to meet people's needs in different levels of granularities and from different perspectives. In this paper, we stand on the view point of granular computing and provide our understanding on multi-level and multi-view of knowledge through granular knowledge structures (GKS). Representation of granular knowledge structures, operations for building granular knowledge structures and how to use them are investigated. As an illustration, we provide some examples through results from an analysis of proceeding papers. Results show that granular knowledge structures could help users get better understanding of the knowledge source from set theoretical, logical and visual point of views. One may consider using them to meet specific needs or solve certain kinds of problems.

  5. Energy Migration Upconversion in Ce(III)-Doped Heterogeneous Core-Shell-Shell Nanoparticles.

    Science.gov (United States)

    Chen, Xian; Jin, Limin; Sun, Tianying; Kong, Wei; Yu, Siu Fung; Wang, Feng

    2017-07-19

    One major challenge in upconversion research is to develop new materials and structures to expand the emission spectrum. Herein, a heterogeneous core-shell-shell nanostructure of NaYbF4 :Gd/Tm@NaGdF4 @CaF2 :Ce is developed to realize efficient photon upconversion in Ce(3+) ions through a Gd-mediated energy migration process. The design takes advantage of CaF2 host that reduces the 4f-5d excitation frequency of Ce(3+) to match the emission line of Gd(3+) . Meanwhile, CaF2 is isostructural with NaGdF4 and can form a continuous crystalline lattice with the core layer. As a result, effective Yb(3+) → Tm(3+) → Gd(3+) → Ce(3+) energy transfer can be established in a single nanoparticle. This effect enables efficient ultraviolet emission of Ce(3+) following near infrared excitation into the core layer. The Ce(3+) upconversion emission achieved in the core-shell-shell nanoparticles features broad bandwidth and long lifetime, which offers exciting opportunities of realizing tunable lasing emissions in the ultraviolet spectral region. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. DISCUSSIONS ON STRUCTURAL COUPLING

    Institute of Scientific and Technical Information of China (English)

    ZHU Wenbin; GUO Lingzhi; MA Ruishi; SUN Yan; WANG Feng

    2004-01-01

    The structural coupling is a common geological phenomenon. The structural differences between eastern and western active continental margins of modern Pacific and between paleo-Pacific and modern-Pacific continental margins are related to the characteristics and status of the subducting oceanic plate, namely, 1. subducting angle; 2. change in subducting angle; 3. subducting velocity; 4. change in subducting velocity; 5. subduction depth; 6. horizontal distance between the leading edge of the subducting plate and the trench; 7. the structural form of the subducting plate at the 670km boundary between the upper and lower mantle; 8. the displacement and the direction of displacement of subducting plate. The control and influence toward the shallow-level structures by the deep-level structural activities is a detailed representation of the structural coupling on active continental margin.The basin-maintain coupling phenomenon is an intracontinental structural coupling. The far field effect of collision between Indian plate and Eurasian plate results in the occurrence of intracontinental A-type subduction in central Asia, and the A-type subduction is the key factor that results in the atrophy of basins and the formation of mountain systems.

  7. Cell packing structures

    KAUST Repository

    Pottmann, Helmut

    2015-03-03

    This paper is an overview of architectural structures which are either composed of polyhedral cells or closely related to them. We introduce the concept of a support structure of such a polyhedral cell packing. It is formed by planar quads and obtained by connecting corresponding vertices in two combinatorially equivalent meshes whose corresponding edges are coplanar and thus determine planar quads. Since corresponding triangle meshes only yield trivial structures, we focus on support structures associated with quad meshes or hex-dominant meshes. For the quadrilateral case, we provide a short survey of recent research which reveals beautiful relations to discrete differential geometry. Those are essential for successfully initializing numerical optimization schemes for the computation of quad-based support structures. Hex-dominant structures may be designed via Voronoi tessellations, power diagrams, sphere packings and various extensions of these concepts. Apart from the obvious application as load-bearing structures, we illustrate here a new application to shading and indirect lighting. On a higher level, our work emphasizes the interplay between geometry, optimization, statics, and manufacturing, with the overall aim of combining form, function and fabrication into novel integrated design tools.

  8. Chromatin Structure and Function

    CERN Document Server

    Wolffe, Alan P

    1999-01-01

    The Third Edition of Chromatin: Structure and Function brings the reader up-to-date with the remarkable progress in chromatin research over the past three years. It has been extensively rewritten to cover new material on chromatin remodeling, histone modification, nuclear compartmentalization, DNA methylation, and transcriptional co-activators and co-repressors. The book is written in a clear and concise fashion, with 60 new illustrations. Chromatin: Structure and Function provides the reader with a concise and coherent account of the nature, structure, and assembly of chromatin and its active

  9. Deployable geodesic truss structure

    Science.gov (United States)

    Mikulas, Martin M., Jr. (Inventor); Rhodes, Marvin D. (Inventor); Simonton, J. Wayne (Inventor)

    1987-01-01

    A deployable geodesic truss structure which can be deployed from a stowed state to an erected state is described. The truss structure includes a series of bays, each bay having sets of battens connected by longitudinal cross members which give the bay its axial and torsional stiffness. The cross members are hinged at their mid point by a joint so that the cross members are foldable for deployment or collapsing. The bays are deployed and stabilized by actuator means connected between the mid point joints of the cross members. Hinged longerons may be provided to also connect the sets of battens and to collapse for stowing with the rest of the truss structure.

  10. Wind Loads on Structures

    DEFF Research Database (Denmark)

    Dyrbye, Claes; Hansen, Svend Ole

    pressure to structural response) and design criteria. Starting with an introduction of the wind load chain, the book moves on to meteorological considerations, atmospheric boundary layer, static wind load, dynamic wind load and scaling laws used in wind-tunnel tests. The dynamic wind load covers vibrations......Wind loads have to be taken into account when designing civil engineering structures. The wind load on structures can be systematised by means of the wind load chain: wind climate (global), terrain (wind at low height), aerodynamic response (wind load to pressure), mechanical response (wind...

  11. Wind Loads on Structures

    DEFF Research Database (Denmark)

    Dyrbye, Claes; Hansen, Svend Ole

    pressure to structural response) and design criteria. Starting with an introduction of the wind load chain, the book moves on to meteorological considerations, atmospheric boundary layer, static wind load, dynamic wind load and scaling laws used in wind-tunnel tests. The dynamic wind load covers vibrations......Wind loads have to be taken into account when designing civil engineering structures. The wind load on structures can be systematised by means of the wind load chain: wind climate (global), terrain (wind at low height), aerodynamic response (wind load to pressure), mechanical response (wind...

  12. Robustness of Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2011-01-01

    robust design as well as strategies for maintaining the robustness of existing structures throughout their service life. This paper describes an overall theoretical framework for assessing robustness of structures developed within WG1 “Robustness of structures”. Robustness can be defined in different......An important aspect of the COST Action TU0601 “Robustness of structures” concerns the development of a theoretically sound basis for the assessment of robustness and acceptance criteria for structural robustness which can form the basis for development of practical relevant methods for ensuring...

  13. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    of structural reliability, including the theoretical basis for these methods. Partial safety factor codes under current practice are briefly introduced and discussed. A probabilistic code format for obtaining a formal reliability evaluation system that catches the most essential features of the nature......The structural reliability methods quantitatively treat the uncertainty of predicting the behaviour and properties of a structure given the uncertain properties of its geometry, materials, and the actions it is supposed to withstand. This book addresses the probabilistic methods for evaluation...

  14. Equivariant Zariski Structures

    CERN Document Server

    Solanki, Vinesh

    2011-01-01

    A category of equivariant algebras is defined, after introducing some important examples (the first Weyl algebra, $U_{q}(sl_{2}(k))$ for generic q, quantum tori at generic parameter). To each equivariant algebra, a first order theory is assigned. Model theoretic results are established (uncountable categoricity, quantifier elimination to the level of existential formulas) and that an appropriate dimension theory exists for models, making them Zariski structures. A functor from the category of equivariant algebras to the category of Zariski structures is defined and further properties of equivariant structures are briefly discussed.

  15. Structural patterns in nature

    DEFF Research Database (Denmark)

    Wester, Ture

    2003-01-01

    It seemens that some very basic randomly produced geometric/topological patterns are commonly found in Nature and have often very distinctive structural qualities. In Nature we find the same pattern in all scales from the universe to molecules, from solar systems to packing of cells, from glaciers...... to sea shells, from river systems to trees etc. Sometimes this seeming archetypical morphology involve structrual action and sometimes not-but the fact that it often posses efficient structural action opens a tool for evaluation and analysis of structures in nature and at the same time might...

  16. Kernels for structured data

    CERN Document Server

    Gärtner, Thomas

    2009-01-01

    This book provides a unique treatment of an important area of machine learning and answers the question of how kernel methods can be applied to structured data. Kernel methods are a class of state-of-the-art learning algorithms that exhibit excellent learning results in several application domains. Originally, kernel methods were developed with data in mind that can easily be embedded in a Euclidean vector space. Much real-world data does not have this property but is inherently structured. An example of such data, often consulted in the book, is the (2D) graph structure of molecules formed by

  17. Programming language structures

    CERN Document Server

    Organick, Elliott Irving; Plummer, Robert P

    1978-01-01

    Programming Language Structures deals with the structures of programming languages and introduces the reader to five important programming languages: Algol, Fortran, Lisp, Snobol, and Pascal. The fundamental similarities and differences among these languages are discussed. A unifying framework is constructed that can be used to study the structure of other languages, such as Cobol, PL/I, and APL. Several of the tools and methodologies needed to construct large programs are also considered.Comprised of 10 chapters, this book begins with a summary of the relevant concepts and principles about al

  18. Sensemaking, structuring and strategy

    DEFF Research Database (Denmark)

    Nielsen, Renate

    With the purpose of generating a new understanding of how organisations develop, an interpretive perspective at continuous processes in organisations will be applied: more specifically at sensemaking, structuring and strategising....

  19. Robustness of Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2008-01-01

    . According to Danish design rules robustness shall be documented for all structures in high consequence class. The design procedure to document sufficient robustness consists of: 1) Review of loads and possible failure modes / scenarios and determination of acceptable collapse extent; 2) Review......This paper describes the background of the robustness requirements implemented in the Danish Code of Practice for Safety of Structures and in the Danish National Annex to the Eurocode 0, see (DS-INF 146, 2003), (DS 409, 2006), (EN 1990 DK NA, 2007) and (Sørensen and Christensen, 2006). More...... frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure combined with increased requirements to efficiency in design and execution followed by increased risk of human errors has made the need of requirements to robustness of new structures essential...

  20. Structural dynamic modification

    Indian Academy of Sciences (India)

    A Sestieri

    2000-06-01

    Vibration and acoustic requirements are becoming increasingly important in the design of mechanical structures, but they are not usually of primary concern in the design process. So the need to vary the structural behaviour to solve noise and vibration problems often occurs at the prototype stage, giving rise to the so-called structural modification problem. In this paper, the direct problem of determing the new response of a system, after some modifications are introduced into the sestem, is analysed using two different databases: the modal database and the frequency response function database. The limitaions of the modal database are discussed. Structural modifications that can be accounted for are lumped masses, springs, dampers and dynamic absorbers.

  1. Territorial Administrative Budgetary Structure

    Directory of Open Access Journals (Sweden)

    Lucia Risti

    2011-06-01

    Full Text Available Local budget structure is a consequence of the way the country’s venues are organized from the territorial administrative point of view, in communes, towns, municipalities and the capital, Bucharest, in districts.

  2. Extremely deformable structures

    CERN Document Server

    2015-01-01

    Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

  3. Shock structures of astrospheres

    CERN Document Server

    Scherer, Klaus; Kleimann, Jens; Wiengarten, Tobias; Bomans, Dominik J; Weis, Kerstin

    2015-01-01

    The interaction between a supersonic stellar wind and a (super-)sonic interstellar wind has recently been viewed with new interest. We here first give an overview of the modeling, which includes the heliosphere as an example of a special astrosphere. Then we concentrate on the shock structures of fluid models, especially of hydrodynamic (HD) models. More involved models taking into account radiation transfer and magnetic fields are briefly sketched. Even the relatively simple HD models show a rich shock structure, which might be observable in some objects. We employ a single fluid model to study these complex shock structures, and compare the results obtained including heating and cooling with results obtained without these effects. Furthermore, we show that in the hypersonic case valuable information of the shock structure can be obtained from the Rankine-Hugoniot equations. We solved the Euler equations for the single fluid case and also for a case including cooling and heating. We also discuss the analytic...

  4. Differential geometric structures

    CERN Document Server

    Poor, Walter A

    2007-01-01

    This introductory text defines geometric structure by specifying parallel transport in an appropriate fiber bundle and focusing on simplest cases of linear parallel transport in a vector bundle. 1981 edition.

  5. Structural assessment of nanocomposites.

    Science.gov (United States)

    Gan, Yong X

    2012-07-01

    This paper provides an overview on structural assessment of nanocomposite materials. First of all, a brief description of advanced structure characterization methods such as scanning electron microscopy, X-ray diffraction, transmission electron microscopy, atomic force microscopy, and scanning tunneling microscopy is presented. Secondly, applications of these methods for analysis of structures and compositions of typical nanocomposites are introduced. The nanocomposites are formed by different nanoscale processing technologies. Electrochemically polymerized polyaniline (PANi) nanocomposites, thermomechanically processed metal matrix nanocomposites, nanocast ceramic matrix composites are typical examples discussed in this paper. Case studies on several functional nanocomposites for energy storage/conversion, catalysis and sensing applications are mentioned. After that, assessment of the interface structures of nanocomposite materials using surface characterization techniques and mechanical damage models is discussed. Finally, concluding remarks are provided.

  6. Deployable Composite Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is seeking innovative structure technologies that will advance expandable exploration space modules and surface based habitats. To address this need CTD has...

  7. Optimal Sound Absorbing Structures

    CERN Document Server

    Yang, Min; Fu, Caixing; Sheng, Ping

    2016-01-01

    Causal nature of the acoustic response, for any materials or structures, dictates an inequality that relates the absorption spectrum of the sample to its thickness. We present a general recipe for constructing sound-absorbing structures that can attain near-equality for the causal relation with very high absorption performance; such structures are denoted optimal. Our strategy involves using carefully designed acoustic metamaterials as backing to a thin layer of conventional sound absorbing material, e.g., acoustic sponge. By using this design approach, we have realized a 12 cm-thick structure that exhibits broadband, near-perfect flat absorption spectrum starting at around 400 Hz. From the causal relation, the calculated minimum sample thickness is 11.5 cm for the observed absorption spectrum. We present the theory that underlies such absorption performance, involving the evanescent waves and their interaction with a dissipative medium, and show the excellent agreement with the experiment.

  8. FEMA DFIRM Hydraulic Structures

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer and accompanying attribute table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the...

  9. Creep in structures

    Energy Technology Data Exchange (ETDEWEB)

    Zyczkowski, M. (Krakow Univ. of Technology (Poland). Inst. of Mechanics and Machine Design) (ed.)

    1991-01-01

    This volume contains 81 papers divided into three almost equal parts: Constitutive equations, combined loadings; damage, creep crack growth, creep rupture; structures, analytical and numerical methods, optimal design. (orig.).

  10. Bioinspired structured surfaces.

    Science.gov (United States)

    Bhushan, Bharat

    2012-01-24

    Nature has evolved objects with desired functionality using commonly found materials. Nature capitalizes on hierarchical structures to achieve functionality. The understanding of the functions provided by objects and processes found in nature can guide us to produce nanomaterials, nanodevices, and processes with desirable functionality. Various natural objects which provide functionality of commercial interest have been characterized to understand how a natural object provides functionality. We have modeled and fabricated structures in the lab using nature's route and developed optimum structures. Once it is understood how nature does it, optimum structures have been fabricated using smart materials and fabrication techniques. This feature article provides an overview of four topics: Lotus effect, rose petal effect, gecko feet, and shark skin.

  11. Fundamentals of Structural Engineering

    CERN Document Server

    Connor, Jerome J

    2013-01-01

    Fundamentals of Structural Engineering provides a balanced, seamless treatment of both classic, analytic methods and contemporary, computer-based techniques for conceptualizing and designing a structure. The book’s principle goal is to foster an intuitive understanding of structural behavior based on problem solving experience for students of civil engineering and architecture who have been exposed to the basic concepts of engineering mechanics and mechanics of materials. Making it distinct from many other undergraduate textbooks, the authors of this text recognize the notion that engineers reason about behavior using simple models and intuition they acquire through problem solving. The approach adopted in this text develops this type of intuition  by presenting extensive, realistic problems and case studies together with computer simulation, which allows rapid exploration of  how a structure responds to changes in geometry and physical parameters. This book also: Emphasizes problem-based understanding of...

  12. Structures and their analysis

    CERN Document Server

    Fuchs, Maurice Bernard

    2016-01-01

    Addressing structures, this book presents a classic discipline in a modern setting by combining illustrated examples with insights into the solutions. It is the fruit of the author’s many years of teaching the subject and of just as many years of research into the design of optimal structures. Although intended for an advanced level of instruction it has an undergraduate course at its core. Further, the book was written with the advantage of having massive computer power in the background, an aspect which changes the entire approach to many engineering disciplines and in particular to structures. This paradigm shift has dislodged the force (flexibility) method from its former prominence and paved the way for the displacement (stiffness) method, despite the multitude of linear equations it spawns. In this book, however, both methods are taught: the force method offers a perfect vehicle for understanding structural behavior, bearing in mind that it is the displacement method which does the heavy number crunch...

  13. Change in Business Structure

    Data.gov (United States)

    Department of Veterans Affairs — Provides information on whether a company’s change in business structure affects its Data Universal Numbering System (DUNS) Number and its Vendor Information Pages...

  14. Modern frame structure buildings

    National Research Council Canada - National Science Library

    В. М. Першаков; Т. О. Петрова; К. М. Лисницька

    2013-01-01

    The article deals with the design, construction and implementation of reinforced concrete frame structures with span 18, 21 m for agricultural production buildings, hall-premises of public buildings...

  15. Stable generalized complex structures

    CERN Document Server

    Cavalcanti, Gil R

    2015-01-01

    A stable generalized complex structure is one that is generically symplectic but degenerates along a real codimension two submanifold, where it defines a generalized Calabi-Yau structure. We introduce a Lie algebroid which allows us to view such structures as symplectic forms. This allows us to construct new examples of stable structures, and also to define period maps for their deformations in which the background three-form flux is either fixed or not, proving the unobstructedness of both deformation problems. We then use the same tools to establish local normal forms for the degeneracy locus and for Lagrangian branes. Applying our normal forms to the four-dimensional case, we prove that any compact stable generalized complex 4-manifold has a symplectic completion, in the sense that it can be modified near its degeneracy locus to produce a compact symplectic 4-manifold.

  16. Encapsulation with structured triglycerides

    Science.gov (United States)

    Lipids provide excellent materials to encapsulate bioactive compounds for food and pharmaceutical applications. Lipids are renewable, biodegradable, and easily modified to provide additional chemical functionality. The use of structured lipids that have been modified with photoactive properties are ...

  17. Structural Identification Problem

    Directory of Open Access Journals (Sweden)

    Suvorov Aleksei

    2016-01-01

    Full Text Available The identification problem of the existing structures though the Quasi-Newton and its modification, Trust region algorithms is discussed. For the structural problems, which could be represented by means of the mathematical modelling of the finite element code discussed method is extremely useful. The nonlinear minimization problem of the L2 norm for the structures with linear elastic behaviour is solved by using of the Optimization Toolbox of Matlab. The direct and inverse procedures for the composition of the desired function to minimize are illustrated for the spatial 3D truss structure as well as for the problem of plane finite elements. The truss identification problem is solved with 2 and 3 unknown parameters in order to compare the computational efforts and for the graphical purposes. The particular commands of the Matlab codes are present in this paper.

  18. Extracellular matrix structure.

    Science.gov (United States)

    Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K

    2016-02-01

    Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented.

  19. Helical surface structures

    CERN Document Server

    Brandenburg, A; Brandenburg, Axel; Blackman, Eric G.

    2002-01-01

    Over the past few years there has been growing interest in helical magnetic field structures seen at the solar surface, in coronal mass ejections, as well as in the solar wind. Although there is a great deal of randomness in the data, on average the extended structures are mostly left-handed on the northern hemisphere and right-handed on the southern. Surface field structures are also classified as dextral (= right bearing) and sinistral (= left bearing) occurring preferentially in the northern and southern hemispheres respectively. Of particular interest here is a quantitative measurement of the associated emergence rates of helical structures, which translate to magnetic helicity fluxes. In this review, we give a brief survey of what has been found so far and what is expected based on models. Particular emphasis is put on the scale dependence of the associated fields and an attempt is made to estimate the helicity flux of the mean field vs. fluctuating field.

  20. Dielectric assist accelerating structure

    Science.gov (United States)

    Satoh, D.; Yoshida, M.; Hayashizaki, N.

    2016-01-01

    A higher-order TM02 n mode accelerating structure is proposed based on a novel concept of dielectric loaded rf cavities. This accelerating structure consists of ultralow-loss dielectric cylinders and disks with irises which are periodically arranged in a metallic enclosure. Unlike conventional dielectric loaded accelerating structures, most of the rf power is stored in the vacuum space near the beam axis, leading to a significant reduction of the wall loss, much lower than that of conventional normal-conducting linac structures. This allows us to realize an extremely high quality factor and a very high shunt impedance at room temperature. A simulation of a 5 cell prototype design with an existing alumina ceramic indicates an unloaded quality factor of the accelerating mode over 120 000 and a shunt impedance exceeding 650 M Ω /m at room temperature.

  1. Adaptive structures flight experiments

    Science.gov (United States)

    Martin, Maurice

    The topics are presented in viewgraph form and include the following: adaptive structures flight experiments; enhanced resolution using active vibration suppression; Advanced Controls Technology Experiment (ACTEX); ACTEX program status; ACTEX-2; ACTEX-2 program status; modular control patch; STRV-1b Cryocooler Vibration Suppression Experiment; STRV-1b program status; Precision Optical Bench Experiment (PROBE); Clementine Spacecraft Configuration; TECHSAT all-composite spacecraft; Inexpensive Structures and Materials Flight Experiment (INFLEX); and INFLEX program status.

  2. Structure of Proton

    CERN Document Server

    Fayyazuddin, A

    2003-01-01

    Electron--proton scattering in elastic and highly inelastic region is reviewed in a unified approach. The importance of parity--violating scattering due to electro--weak interference in probing the structure of proton is emphasized. The importance of longitudnal spin--spin asymmetry as well as parity violating longitudnal asymmetry to extract the structure functions of proton in both regions are discussed. The recoil polarization of proton in the elastic scattering is also discussed.

  3. Deployable Soft Composite Structures

    OpenAIRE

    Wei Wang; Hugo Rodrigue; Sung-Hoon Ahn

    2016-01-01

    Deployable structure composed of smart materials based actuators can reconcile its inherently conflicting requirements of low mass, good shape adaptability, and high load-bearing capability. This work describes the fabrication of deployable structures using smart soft composite actuators combining a soft matrix with variable stiffness properties and hinge-like movement through a rigid skeleton. The hinge actuator has the advantage of being simple to fabricate, inexpensive, lightweight and sim...

  4. Structured luminescence conversion layer

    Science.gov (United States)

    Berben, Dirk; Antoniadis, Homer; Jermann, Frank; Krummacher, Benjamin Claus; Von Malm, Norwin; Zachau, Martin

    2012-12-11

    An apparatus device such as a light source is disclosed which has an OLED device and a structured luminescence conversion layer deposited on the substrate or transparent electrode of said OLED device and on the exterior of said OLED device. The structured luminescence conversion layer contains regions such as color-changing and non-color-changing regions with particular shapes arranged in a particular pattern.

  5. Purely Functional Structured Programming

    OpenAIRE

    Obua, Steven

    2010-01-01

    The idea of functional programming has played a big role in shaping today's landscape of mainstream programming languages. Another concept that dominates the current programming style is Dijkstra's structured programming. Both concepts have been successfully married, for example in the programming language Scala. This paper proposes how the same can be achieved for structured programming and PURELY functional programming via the notion of LINEAR SCOPE. One advantage of this proposal is that m...

  6. Renovation of Roof Structure

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    1997-01-01

    A 30 year old not-watertight roof based on wooden boards with roofing felt have been changed to a pitched structure with cementos plates. At the same time more thermal insulation has been placed.......A 30 year old not-watertight roof based on wooden boards with roofing felt have been changed to a pitched structure with cementos plates. At the same time more thermal insulation has been placed....

  7. Structure function monitor

    Energy Technology Data Exchange (ETDEWEB)

    McGraw, John T [Placitas, NM; Zimmer, Peter C [Albuquerque, NM; Ackermann, Mark R [Albuquerque, NM

    2012-01-24

    Methods and apparatus for a structure function monitor provide for generation of parameters characterizing a refractive medium. In an embodiment, a structure function monitor acquires images of a pupil plane and an image plane and, from these images, retrieves the phase over an aperture, unwraps the retrieved phase, and analyzes the unwrapped retrieved phase. In an embodiment, analysis yields atmospheric parameters measured at spatial scales from zero to the diameter of a telescope used to collect light from a source.

  8. REACTOR MODERATOR STRUCTURE

    Science.gov (United States)

    Greenstreet, B.L.

    1963-12-31

    A system for maintaining the alignment of moderator block structures in reactors is presented. Integral restraining grids are placed between each layer of blocks in the moderator structure, at the top of the uppermost layer, and at the bottom of the lowermost layer. Slots are provided in the top and bottom surfaces of the moderator blocks so as to provide a keying action with the grids. The grids are maintained in alignment by vertical guiding members disposed about their peripheries. (AEC)

  9. Structural Transformation in Ecuador

    OpenAIRE

    Ricardo Hausmann; Bailey Klinger

    2010-01-01

    This paper applies new techniques and metrics to analyze Ecuador's past record of and future opportunities for structural transformation. Ecuador's export dynamics and the emergence of new export activities have been the historical drivers of the country's growth, but recently Ecuador's export basket has undergone little structural transformation. The same broad sectors continue to dominate, and the overall sophistication of the export basket has actually declined in recent years. In order to...

  10. Estonian Tax Structure

    Directory of Open Access Journals (Sweden)

    Viktor Trasberg

    2014-08-01

    Full Text Available The paper analyses Estonian tax structure changes during the last decade and critically assesses the current situation. The country’s tax mix is rather unique among EU countries – it has one of the highest proportions of consumption taxes in total taxes and the lowest level of capital and profit taxes. Such an unbalanced tax structure creates risks for public finances, limits revenue collection and distorts the business environment.

  11. Trajectory grouping structure

    Directory of Open Access Journals (Sweden)

    Maike Buchin

    2015-03-01

    Full Text Available The collective motion of a set of moving entities like people, birds, or other animals, is characterized by groups arising, merging, splitting, and ending. Given the trajectories of these entities, we define and model a structure that captures all of such changes using the Reeb graph, a concept from topology. The trajectory grouping structure has three natural parameters that allow more global views of the data in group size, group duration, and entity inter-distance. We prove complexity bounds on the maximum number of maximal groups that can be present, and give algorithms to compute the grouping structure efficiently. We also study how the trajectory grouping structure can be made robust, that is, how brief interruptions of groups can be disregarded in the global structure, adding a notion of persistence to the structure. Furthermore, we showcase the results of experiments using data generated by the NetLogo flocking model and from the Starkey project. The Starkey data describe the movement of elk, deer, and cattle. Although there is no ground truth for the grouping structure in this data, the experiments show that the trajectory grouping structure is plausible and has the desired effects when changing the essential parameters. Our research provides the first complete study of trajectory group evolvement, including combinatorial,algorithmic, and experimental results.

  12. Meteorite Seymchan structure

    Science.gov (United States)

    Hontsova, S. S.; Petrova, E. V.; Muftahetdinova, R. F.; Chulanova, V. N.; Grokhovsky, V. I.

    2016-09-01

    The meteorite Seymchan specimen was studied using optical microscopy and scanning electron microscopy. Olivine grains have roundish shapes, which was formed during matter cooling. Different features of the metal structure such as plessite structure and Neimann bands were observed. The oxide edges were observed in the boundaries between phases. The oxides were formed in the terrestrial conditions. The boundary regions between metal and olivine in the meteorite contain grains of troilite, schreibersite, and chromite.

  13. Integral Textile Ceramic Structures

    Science.gov (United States)

    Marshall, David B.; Cox, Brian N.

    2008-08-01

    A new paradigm for ceramic composite structural components enables functionality in heat exchange, transpiration, detailed shape, and thermal strain management that significantly exceeds the prior art. The paradigm is based on the use of three-dimensional fiber reinforcement that is tailored to the specific shape, stress, and thermal requirements of a structural application and therefore generally requires innovative textile methods for each realization. Key features include the attainment of thin skins (less than 1 mm) that are nevertheless structurally robust, transpiration holes formed without cutting fibers, double curvature, compliant integral attachment to other structures that avoids thermal stress buildup, and microcomposite ceramic matrices that minimize spalling and allow the formation of smooth surfaces. All these features can be combined into structures of very varied gross shape and function, using a wide range of materials such as all-oxide systems and SiC and carbon fibers in SiC matrices. Illustrations are drawn from rocket nozzles, thermal protection systems, and gas turbine engines. The new design challenges that arise for such material/structure systems are being met by specialized computational modeling that departs significantly in the representation of materials behavior from that used in conventional finite element methods.

  14. Structural optimization of free-form reciprocal structures

    DEFF Research Database (Denmark)

    Parigi, Dario

    2014-01-01

    This paper presents an optimization algorithm for the design of structurally efficient free-form reciprocal structures. Because of the geometric complexity of reciprocal structures, only a few structural studies have been carried out so far, and we have a limited knowledge of the relation between...... geometry and structural behaviour in reciprocal structures. This study takes advantage of the preceding work carried by the author on the Reciprocalizer, a software tool for the generation of reciprocal geometries. The Reciprocalizer has been included into a structural optimization algorithm...... for the generation of structurally efficient free-form reciprocal structures....

  15. Structural prediction in aphasia

    Directory of Open Access Journals (Sweden)

    Tessa Warren

    2015-05-01

    Full Text Available There is considerable evidence that young healthy comprehenders predict the structure of upcoming material, and that their processing is facilitated when they encounter material matching those predictions (e.g., Staub & Clifton, 2006; Yoshida, Dickey & Sturt, 2013. However, less is known about structural prediction in aphasia. There is evidence that lexical prediction may be spared in aphasia (Dickey et al., 2014; Love & Webb, 1977; cf. Mack et al, 2013. However, predictive mechanisms supporting facilitated lexical access may not necessarily support structural facilitation. Given that many people with aphasia (PWA exhibit syntactic deficits (e.g. Goodglass, 1993, PWA with such impairments may not engage in structural prediction. However, recent evidence suggests that some PWA may indeed predict upcoming structure (Hanne, Burchert, De Bleser, & Vashishth, 2015. Hanne et al. tracked the eyes of PWA (n=8 with sentence-comprehension deficits while they listened to reversible subject-verb-object (SVO and object-verb-subject (OVS sentences in German, in a sentence-picture matching task. Hanne et al. manipulated case and number marking to disambiguate the sentences’ structure. Gazes to an OVS or SVO picture during the unfolding of a sentence were assumed to indicate prediction of the structure congruent with that picture. According to this measure, the PWA’s structural prediction was impaired compared to controls, but they did successfully predict upcoming structure when morphosyntactic cues were strong and unambiguous. Hanne et al.’s visual-world evidence is suggestive, but their forced-choice sentence-picture matching task places tight constraints on possible structural predictions. Clearer evidence of structural prediction would come from paradigms where the content of upcoming material is not as constrained. The current study used self-paced reading study to examine structural prediction among PWA in less constrained contexts. PWA (n=17 who

  16. RNA Thermodynamic Structural Entropy.

    Science.gov (United States)

    Garcia-Martin, Juan Antonio; Clote, Peter

    2015-01-01

    Conformational entropy for atomic-level, three dimensional biomolecules is known experimentally to play an important role in protein-ligand discrimination, yet reliable computation of entropy remains a difficult problem. Here we describe the first two accurate and efficient algorithms to compute the conformational entropy for RNA secondary structures, with respect to the Turner energy model, where free energy parameters are determined from UV absorption experiments. An algorithm to compute the derivational entropy for RNA secondary structures had previously been introduced, using stochastic context free grammars (SCFGs). However, the numerical value of derivational entropy depends heavily on the chosen context free grammar and on the training set used to estimate rule probabilities. Using data from the Rfam database, we determine that both of our thermodynamic methods, which agree in numerical value, are substantially faster than the SCFG method. Thermodynamic structural entropy is much smaller than derivational entropy, and the correlation between length-normalized thermodynamic entropy and derivational entropy is moderately weak to poor. In applications, we plot the structural entropy as a function of temperature for known thermoswitches, such as the repression of heat shock gene expression (ROSE) element, we determine that the correlation between hammerhead ribozyme cleavage activity and total free energy is improved by including an additional free energy term arising from conformational entropy, and we plot the structural entropy of windows of the HIV-1 genome. Our software RNAentropy can compute structural entropy for any user-specified temperature, and supports both the Turner'99 and Turner'04 energy parameters. It follows that RNAentropy is state-of-the-art software to compute RNA secondary structure conformational entropy. Source code is available at https://github.com/clotelab/RNAentropy/; a full web server is available at http

  17. RNA Thermodynamic Structural Entropy.

    Directory of Open Access Journals (Sweden)

    Juan Antonio Garcia-Martin

    Full Text Available Conformational entropy for atomic-level, three dimensional biomolecules is known experimentally to play an important role in protein-ligand discrimination, yet reliable computation of entropy remains a difficult problem. Here we describe the first two accurate and efficient algorithms to compute the conformational entropy for RNA secondary structures, with respect to the Turner energy model, where free energy parameters are determined from UV absorption experiments. An algorithm to compute the derivational entropy for RNA secondary structures had previously been introduced, using stochastic context free grammars (SCFGs. However, the numerical value of derivational entropy depends heavily on the chosen context free grammar and on the training set used to estimate rule probabilities. Using data from the Rfam database, we determine that both of our thermodynamic methods, which agree in numerical value, are substantially faster than the SCFG method. Thermodynamic structural entropy is much smaller than derivational entropy, and the correlation between length-normalized thermodynamic entropy and derivational entropy is moderately weak to poor. In applications, we plot the structural entropy as a function of temperature for known thermoswitches, such as the repression of heat shock gene expression (ROSE element, we determine that the correlation between hammerhead ribozyme cleavage activity and total free energy is improved by including an additional free energy term arising from conformational entropy, and we plot the structural entropy of windows of the HIV-1 genome. Our software RNAentropy can compute structural entropy for any user-specified temperature, and supports both the Turner'99 and Turner'04 energy parameters. It follows that RNAentropy is state-of-the-art software to compute RNA secondary structure conformational entropy. Source code is available at https://github.com/clotelab/RNAentropy/; a full web server is available at http

  18. Hierarchically Structured Electrospun Fibers

    Directory of Open Access Journals (Sweden)

    Nicole E. Zander

    2013-01-01

    Full Text Available Traditional electrospun nanofibers have a myriad of applications ranging from scaffolds for tissue engineering to components of biosensors and energy harvesting devices. The generally smooth one-dimensional structure of the fibers has stood as a limitation to several interesting novel applications. Control of fiber diameter, porosity and collector geometry will be briefly discussed, as will more traditional methods for controlling fiber morphology and fiber mat architecture. The remainder of the review will focus on new techniques to prepare hierarchically structured fibers. Fibers with hierarchical primary structures—including helical, buckled, and beads-on-a-string fibers, as well as fibers with secondary structures, such as nanopores, nanopillars, nanorods, and internally structured fibers and their applications—will be discussed. These new materials with helical/buckled morphology are expected to possess unique optical and mechanical properties with possible applications for negative refractive index materials, highly stretchable/high-tensile-strength materials, and components in microelectromechanical devices. Core-shell type fibers enable a much wider variety of materials to be electrospun and are expected to be widely applied in the sensing, drug delivery/controlled release fields, and in the encapsulation of live cells for biological applications. Materials with a hierarchical secondary structure are expected to provide new superhydrophobic and self-cleaning materials.

  19. PRSEUS Structural Concept Development

    Science.gov (United States)

    Velicki, Alex; Jegley, Dawn

    2014-01-01

    A lighter, more robust airframe is one of the key technological advancements necessary for the successful launch of any large next-generation transport aircraft. Such a premise dictates that considerable improvements beyond current state-of-the-art aluminum structures is needed, and that improvements of this magnitude will require an extensive use of composite materials that are not only lightweight, but also economical to produce. To address this challenge, researchers at NASA and The Boeing Company are developing a novel structural concept called the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) under the Environmentally Responsible Aviation (ERA) Project. It is an integrally stiffened panel concept that is stitched together and designed to maintain residual load-carrying capabilities under a variety of damage scenarios. In addition to improved structural performance, an important facet of this unique arrangement of stitched carbon fibers is its innovative manufacturing method that has the potential to lower fabrication costs by eliminating fasteners and autoclave cures. The rationale and development status for this new approach forms the basis of the work described in this paper. The test specimens described herein were fabricated, or are currently being fabricated, by The Boeing Company, while the structural analyses and testing tasks are being performed by NASA and Boeing personnel.

  20. Prosodic Structure as a Parallel to Musical Structure

    Science.gov (United States)

    Heffner, Christopher C.; Slevc, L. Robert

    2015-01-01

    What structural properties do language and music share? Although early speculation identified a wide variety of possibilities, the literature has largely focused on the parallels between musical structure and syntactic structure. Here, we argue that parallels between musical structure and prosodic structure deserve more attention. We review the evidence for a link between musical and prosodic structure and find it to be strong. In fact, certain elements of prosodic structure may provide a parsimonious comparison with musical structure without sacrificing empirical findings related to the parallels between language and music. We then develop several predictions related to such a hypothesis. PMID:26733930

  1. Structure and biophysics

    CERN Document Server

    Puglisi, Joseph D

    2007-01-01

    This volume is a collection of articles from the proceedings of the ISSBMR 7th Course: Structure and Biophysics - New Technologies for Current Challenges in Biology and Beyond. This NATO Advanced Institute (ASI) was held in Erice at the Ettore Majorana Foundation and Centre for Scientific Culture on 22 June through 3 July 2005. The ASI brought together a diverse group of experts in the fields of Structural Biology, Biophysics and Physics. Prominent lecturers, from seven different countries, and students from around the world participated in the NATO ASI organized by Professors Joseph Puglisi (Stanford University, USA) and Alexander Arseniev (Moscow, RU). Advances in nuclear magnetic resonance spectroscopy (NMR) and x-ray crystallography have allowed the three-dimensional structures of many biological macromolecules and their complexes, including the ribosome and RNA polymerase to be solved. Fundamental principles of NMR spectroscopy and dynamics, x-ray crystallography, computation and experimental dynamics we...

  2. Structural motion engineering

    CERN Document Server

    Connor, Jerome

    2014-01-01

    This innovative volume provides a systematic treatment of the basic concepts and computational procedures for structural motion design and engineering for civil installations. The authors illustrate the application of motion control to a wide spectrum of buildings through many examples. Topics covered include optimal stiffness distributions for building-type structures, the role of damping in controlling motion, tuned mass dampers, base isolation systems, linear control, and nonlinear control. The book's primary objective is the satisfaction of motion-related design requirements, such as restrictions on displacement and acceleration. The book is ideal for practicing engineers and graduate students. This book also: ·         Broadens practitioners' understanding of structural motion control, the enabling technology for motion-based design ·         Provides readers the tools to satisfy requirements of modern, ultra-high strength materials that lack corresponding stiffness, where the motion re...

  3. Freeform Honeycomb Structures

    KAUST Repository

    Jiang, Caigui

    2014-07-01

    Motivated by requirements of freeform architecture, and inspired by the geometry of hexagonal combs in beehives, this paper addresses torsion-free structures aligned with hexagonal meshes. Since repetitive geometry is a very important contribution to the reduction of production costs, we study in detail “honeycomb structures”, which are defined as torsion-free structures where the walls of cells meet at 120 degrees. Interestingly, the Gauss-Bonnet theorem is useful in deriving information on the global distribution of node axes in such honeycombs. This paper discusses the computation and modeling of honeycomb structures as well as applications, e.g. for shading systems, or for quad meshing. We consider this paper as a contribution to the wider topic of freeform patterns, polyhedral or otherwise. Such patterns require new approaches on the technical level, e.g. in the treatment of smoothness, but they also extend our view of what constitutes aesthetic freeform geometry.

  4. Graphene heat dissipating structure

    Energy Technology Data Exchange (ETDEWEB)

    Washburn, Cody M.; Lambert, Timothy N.; Wheeler, David R.; Rodenbeck, Christopher T.; Railkar, Tarak A.

    2017-08-01

    Various technologies presented herein relate to forming one or more heat dissipating structures (e.g., heat spreaders and/or heat sinks) on a substrate, wherein the substrate forms part of an electronic component. The heat dissipating structures are formed from graphene, with advantage being taken of the high thermal conductivity of graphene. The graphene (e.g., in flake form) is attached to a diazonium molecule, and further, the diazonium molecule is utilized to attach the graphene to material forming the substrate. A surface of the substrate is treated to comprise oxide-containing regions and also oxide-free regions having underlying silicon exposed. The diazonium molecule attaches to the oxide-free regions, wherein the diazonium molecule bonds (e.g., covalently) to the exposed silicon. Attachment of the diazonium plus graphene molecule is optionally repeated to enable formation of a heat dissipating structure of a required height.

  5. Implications of social structure

    DEFF Research Database (Denmark)

    Brask, Josefine Bohr

    social environment of the individual. In the last two studies, we investigate the role of social structure for cooperation in a classic natural system for behavioural research, the Trinidadian guppy (Poecilia reticulata), by means of computer simulations. Cooperation contradicts evolutionary theory......, we investigate empirically the role of the social environment of individuals for their communication patterns. Our study species is a song bird, the black-capped chickadee (Poecile atricapillus). The results suggest that individual communication in this species is influenced by features of the local...... and requires special explanations. Theory predicts that heterogeneous social structure can support and promote cooperation in populations. Our simulations suggest that social structure may not be able to explain the presence of cooperation in the guppy system. Overall the thesis provides new insights...

  6. Human Spacecraft Structures Internship

    Science.gov (United States)

    Bhakta, Kush

    2017-01-01

    DSG will be placed in halo orbit around themoon- Platform for international/commercialpartners to explore lunar surface- Testbed for technologies needed toexplore Mars• Habitat module used to house up to 4crew members aboard the DSG- Launched on EM-3- Placed inside SLS fairing Habitat Module - Task Habitat Finite Element Model Re-modeled entire structure in NX2) Used Beam and Shell elements torepresent the pressure vessel structure3) Created a point cloud of centers of massfor mass components- Can now inspect local moments andinertias for thrust ring application8/ Habitat Structure – Docking Analysis Problem: Artificial Gravity may be necessary forastronaut health in deep spaceGoal: develop concepts that show how artificialgravity might be incorporated into a spacecraft inthe near term Orion Window Radiant Heat Testing.

  7. Structure learning in action

    Science.gov (United States)

    Braun, Daniel A.; Mehring, Carsten; Wolpert, Daniel M.

    2010-01-01

    ‘Learning to learn’ phenomena have been widely investigated in cognition, perception and more recently also in action. During concept learning tasks, for example, it has been suggested that characteristic features are abstracted from a set of examples with the consequence that learning of similar tasks is facilitated—a process termed ‘learning to learn’. From a computational point of view such an extraction of invariants can be regarded as learning of an underlying structure. Here we review the evidence for structure learning as a ‘learning to learn’ mechanism, especially in sensorimotor control where the motor system has to adapt to variable environments. We review studies demonstrating that common features of variable environments are extracted during sensorimotor learning and exploited for efficient adaptation in novel tasks. We conclude that structure learning plays a fundamental role in skill learning and may underlie the unsurpassed flexibility and adaptability of the motor system. PMID:19720086

  8. Laser induced structural vibration

    Science.gov (United States)

    Koss, L. L.; Tobin, R. C.

    1983-01-01

    A technique is described for exciting structural vibration by using a focussed laser beam to vaporize material from a target attached to the structure. The rapid ejection of material results in an impulsive reaction to the target which is transmitted to the structure. The method has been studied with a Nd: glass laser, operated in the long pulse mode, in combination with a bismuth target attached in turn to a ballistic pendulum and cantilever beam. The specific mechanical energy was found to be proportional to the laser pulse energy raised to a power in the range 2.5-2.9. The highest efficiency of energy transfer achieved for the first vibrational mode of the cantilever was about 2 millipercent for the maximum laser pulse energy used, 1.5 J, the signal to noise ratio then being about 40 dB.

  9. Dynamic Data Structures

    DEFF Research Database (Denmark)

    Kejlberg-Rasmussen, Casper

    to a given key? The updates we can do are: inserting a new key or deleting a given key. Our dictionary has the working set property, which means that the running time of a query depends on the query distribution. Specifically the time to search for a key depends on when we last searched for it. Our data...... statements about our data structure, which are based on the structure of the underlying problem, that we are trying to solve. We can rely on the properties of the invariants when performing queries, and in return we need to ensure that the invariants remain true after we perform updates. When designing data......In this thesis I will address three dynamic data structure problems using the concept of invariants. The first problem is maintaining a dynamically changing set of keys – a dictionary – where the queries we can ask are: does it contain a given key? and what is the preceding (or succeeding) key...

  10. Dynamic Data Structures

    DEFF Research Database (Denmark)

    Tsakalidis, Konstantinos

    We study dynamic data structures for different variants of orthogonal range reporting query problems. In particular, we consider (1) the planar orthogonal 3-sided range reporting problem: given a set of points in the plane, report the points that lie within a given 3-sided rectangle with one....... Dynamic problems like the above arise in various applications of network optimization, VLSI layout design, computer graphics and distributed computing. For the first problem, we present dynamic data structures for internal and external memory that support planar orthogonal 3-sided range reporting queries......, and insertions and deletions of points efficiently over an average case sequence of update operations. The external memory data structures find applications in constraint and temporal databases. In particular, we assume that the coordinates of the points are drawn from different probabilistic distributions...

  11. Dynamic Data Structures

    DEFF Research Database (Denmark)

    Kejlberg-Rasmussen, Casper

    statements about our data structure, which are based on the structure of the underlying problem, that we are trying to solve. We can rely on the properties of the invariants when performing queries, and in return we need to ensure that the invariants remain true after we perform updates. When designing data......In this thesis I will address three dynamic data structure problems using the concept of invariants. The first problem is maintaining a dynamically changing set of keys – a dictionary – where the queries we can ask are: does it contain a given key? and what is the preceding (or succeeding) key...... to a given key? The updates we can do are: inserting a new key or deleting a given key. Our dictionary has the working set property, which means that the running time of a query depends on the query distribution. Specifically the time to search for a key depends on when we last searched for it. Our data...

  12. Structure of potato starch

    DEFF Research Database (Denmark)

    Bertoft, Eric; Blennow, Andreas

    2016-01-01

    are interconnected by long chains with more than 36 residues. The clusters consist of still smaller, very tightly branched building blocks. The clusters direct the semicrystalline structures found inside the starch granules. The crystals, which are ~5.2. nm thick, contain double helices formed from the external...... chains extending from the clusters. A range of enzymes is involved in the biosynthesis of the cluster structures and linear segments. These are required for sugar activation, chain elongation, branching, and trimming of the final branching pattern. As an interesting feature, potato amylopectin...... is substituted with low amounts of phosphate groups monoesterified to the C-3 and the C-6 carbons of the glucose units. They seem to align well in the granular structure and have tremendous effects on starch degradation in the potato and functionality of the refined starch. A specific dikinase catalyzes...

  13. Folksodriven Structure Network

    CERN Document Server

    Mas, Massimiliano Dal

    2011-01-01

    Nowadays folksonomy is used as a system derived from user-generated electronic tags or keywords that annotate and describe online content. But it is not a classification system as an ontology. To consider it as a classification system it would be necessary to share a representation of contexts by all the users. This paper is proposing the use of folksonomies and network theory to devise a new concept: a "Folksodriven Structure Network" to represent folksonomies. This paper proposed and analyzed the network structure of Folksodriven tags thought as folsksonomy tags suggestions for the user on a dataset built on chosen websites. It is observed that the Folksodriven Network has relative low path lengths checking it with classic networking measures (clustering coefficient). Experiment result shows it can facilitate serendipitous discovery of content among users. Neat examples and clear formulas can show how a "Folksodriven Structure Network" can be used to tackle ontology mapping challenges.

  14. Structural power flow measurement

    Energy Technology Data Exchange (ETDEWEB)

    Falter, K.J.; Keltie, R.F.

    1988-12-01

    Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

  15. Structural Sparse Tracking

    KAUST Repository

    Zhang, Tianzhu

    2015-06-01

    Sparse representation has been applied to visual tracking by finding the best target candidate with minimal reconstruction error by use of target templates. However, most sparse representation based trackers only consider holistic or local representations and do not make full use of the intrinsic structure among and inside target candidates, thereby making the representation less effective when similar objects appear or under occlusion. In this paper, we propose a novel Structural Sparse Tracking (SST) algorithm, which not only exploits the intrinsic relationship among target candidates and their local patches to learn their sparse representations jointly, but also preserves the spatial layout structure among the local patches inside each target candidate. We show that our SST algorithm accommodates most existing sparse trackers with the respective merits. Both qualitative and quantitative evaluations on challenging benchmark image sequences demonstrate that the proposed SST algorithm performs favorably against several state-of-the-art methods.

  16. Implications of social structure

    DEFF Research Database (Denmark)

    Brask, Josefine Bohr

    Social systems in nature are characterised by heterogeneous social structures. The pattern of social interactions or associations between individuals within populations (i.e. their social network) is typically non-random. Such structuring may have important implications for the expression......, we investigate empirically the role of the social environment of individuals for their communication patterns. Our study species is a song bird, the black-capped chickadee (Poecile atricapillus). The results suggest that individual communication in this species is influenced by features of the local...... social environment of the individual. In the last two studies, we investigate the role of social structure for cooperation in a classic natural system for behavioural research, the Trinidadian guppy (Poecilia reticulata), by means of computer simulations. Cooperation contradicts evolutionary theory...

  17. Superalloy Lattice Block Structures

    Science.gov (United States)

    Nathal, M. V.; Whittenberger, J. D.; Hebsur, M. G.; Kantzos, P. T.; Krause, D. L.

    2004-01-01

    Initial investigations of investment cast superalloy lattice block suggest that this technology will yield a low cost approach to utilize the high temperature strength and environmental resistance of superalloys in lightweight, damage tolerant structural configurations. Work to date has demonstrated that relatively large superalloy lattice block panels can be successfully investment cast from both IN-718 and Mar-M247. These castings exhibited mechanical properties consistent with the strength of the same superalloys measured from more conventional castings. The lattice block structure also accommodates significant deformation without failure, and is defect tolerant in fatigue. The potential of lattice block structures opens new opportunities for the use of superalloys in future generations of aircraft applications that demand strength and environmental resistance at elevated temperatures along with low weight.

  18. Dynamics of structures

    CERN Document Server

    Paultre, Patrick

    2013-01-01

    This book covers structural dynamics from a theoretical and algorithmic approach. It covers systems with both single and multiple degrees-of-freedom. Numerous case studies are given to provide the reader with a deeper insight into the practicalities of the area, and the solutions to these case studies are given in terms of real-time and frequency in both geometric and modal spaces. Emphasis is also given to the subject of seismic loading. The text is based on many lectures on the subject of structural dynamics given at numerous institutions and thus will be an accessible and practical aid to

  19. Cellular structural biology.

    Science.gov (United States)

    Ito, Yutaka; Selenko, Philipp

    2010-10-01

    While we appreciate the complexity of the intracellular environment as a general property of every living organism, we collectively lack the appropriate tools to analyze protein structures in a cellular context. In-cell NMR spectroscopy represents a novel biophysical tool to investigate the conformational and functional characteristics of biomolecules at the atomic level inside live cells. Here, we review recent in-cell NMR developments and provide an outlook towards future applications in prokaryotic and eukaryotic cells. We hope to thereby emphasize the usefulness of in-cell NMR techniques for cellular studies of complex biological processes and for structural analyses in native environments. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Structured Analog CMOS Design

    CERN Document Server

    Stefanovic, Danica

    2008-01-01

    Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

  1. POLYMERIC SURFACTANT STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    P.M. Saville; J.W. White

    2001-01-01

    Polymeric surfactants are amongst the most widespread of all polymers. In nature, proteins and polysaccharides cause self organization as a result of this surfactancy; in industry, polymeric surfactants play key roles in the food, explosives and surface coatings sectors. The generation of useful nano- and micro-structures in films and emulsions as a result of polymer amphiphilicity and the application of mechanical stress is discussed. The use of X-ray and neutron small angle scattering and reflectivity to measure these structures and their dynamic properties will be described. New results on linear and dendritic polymer surfactants are presented.

  2. Kilns and Firing Structures

    OpenAIRE

    Nicholson, Paul

    2010-01-01

    The purpose of firing pottery is to change clay, a plastic material, into ceramic, which is aplastic. Examined here are structures designed to fire pottery or faience or to make glass (although the latter might be better described as furnaces). Firing can take place in an open, bonfire-like environment, which can also be enclosed as a firing structure. Beyond this is the development of the true kiln of which there are two main types: updraft and downdraft. The first of these is by far the mos...

  3. Objective Eulerian Coherent Structures

    CERN Document Server

    Serra, M

    2015-01-01

    We define objective Eulerian Coherent Structures (OECSs) in two-dimensional, non-autonomous dynamical systems as instantaneously most influential material curves. Specifically, OECSs are stationary curves of the averaged instantaneous material stretching-rate or material shearing-rate functionals. From these objective (frame-invariant) variational principles, we obtain explicit differential equations for hyperbolic, elliptic and parabolic OECSs. As illustration, we compute OECSs in an unsteady ocean velocity data set. In comparison to structures suggested by other common Eulerian diagnostic tools, we find OECSs to be the correct short-term cores of observed trajectory deformation patterns.

  4. Nuclear structure and astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Grawe, H [Gesellschaft fuer Schwerionenforschung (GSI), D-64291 Darmstadt (Germany); Langanke, K [Gesellschaft fuer Schwerionenforschung (GSI), D-64291 Darmstadt (Germany); MartInez-Pinedo, G [Gesellschaft fuer Schwerionenforschung (GSI), D-64291 Darmstadt (Germany)

    2007-09-15

    The nuclear structure in regions of the Segre chart which are of astrophysical importance is reviewed. The main emphasis is put on those nuclei that are relevant for stellar nucleosynthesis in fusion processes, and in slow neutron capture, both located close to stability, rapid neutron capture close to the neutron dripline and rapid proton capture near the proton dripline. The basic features of modern nuclear structure, their importance and future potential for astrophysics and their level of predictibility are critically discussed. Recent experimental and theoretical results for shell evolution far off the stability line and consequences for weak interaction processes, proton and neutron capture are reviewed.

  5. Structural dynamics analysis

    Science.gov (United States)

    Housner, J. M.; Anderson, M.; Belvin, W.; Horner, G.

    1985-01-01

    Dynamic analysis of large space antenna systems must treat the deployment as well as vibration and control of the deployed antenna. Candidate computer programs for deployment dynamics, and issues and needs for future program developments are reviewed. Some results for mast and hoop deployment are also presented. Modeling of complex antenna geometry with conventional finite element methods and with repetitive exact elements is considered. Analytical comparisons with experimental results for a 15 meter hoop/column antenna revealed the importance of accurate structural properties including nonlinear joints. Slackening of cables in this antenna is also a consideration. The technology of designing actively damped structures through analytical optimization is discussed and results are presented.

  6. Structural model integrity

    Science.gov (United States)

    Wallerstein, D. V.; Lahey, R. S.; Haggenmacher, G. W.

    1977-01-01

    Many of the practical aspects and problems of ensuring the integrity of a structural model are discussed, as well as the steps which have been taken in the NASTRAN system to assure that these checks can be routinely performed. Model integrity as used applies not only to the structural model but also to the loads applied to the model. Emphasis is also placed on the fact that when dealing with substructure analysis, all of the checking procedures discussed should be applied at the lowest level of substructure prior to any coupling.

  7. Stellar structure of magnetars

    Science.gov (United States)

    Dong, JianMin; Zuo, Wei; Gu, JianZhong; Shang, XinLe

    2016-04-01

    Magnetars are strong magnetized neutron stars which could emit quiescent X-ray, repeating burst of soft gamma ray, and even the giant flares. We investigate the effects of magnetic fields on the structure of isolated magnetars. The stellar structure together with the magnetic field configuration can be obtained at the same time within a self-consistent procedure. The magnetar mass and radius are found to be weakly enhanced by the strong magnetic fields. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.

  8. Dissipative structures and chaos

    CERN Document Server

    Mori, Hazime

    1998-01-01

    This monograph consists of two parts and gives an approach to the physics of open nonequilibrium systems. Part I derives the phenomena of dissipative structures on the basis of reduced evolution equations and includes Bénard convection and Belousov-Zhabotinskii chemical reactions. Part II discusses the physics and structures of chaos. While presenting a construction of the statistical physics of chaos, the authors unify the geometrical and statistical descriptions of dynamical systems. The shape of chaotic attractors is characterized, as are the mixing and diffusion of chaotic orbits and the fluctuation of energy dissipation exhibited by chaotic systems.

  9. Structure refinement of astrophyllite

    Institute of Scientific and Technical Information of China (English)

    MA; Zhesheng

    2001-01-01

    [1]Abdel-Fattah M. Abdel-Rahman., Mineral chemistry and paragenesis of astrophyllite from Egypt, Mineralogical Magazine, 1992, 56: 17-26.[2]Liu Yan, Ma Zhesheng, Han Xiuling et al, Astrophyllite from the Namjabarwa Area, Eastern Tibet, Acta Petrologica et Mineralogica, 1997,16(4): 338-340.[3]Peng Zhizhong, Ma Zhesheng, The crystal structure of astrophyllite (in Russian), Scientia Sinica, 1963, 12(2): 272-276.[4]Pen Zhizhong, Ma Zhesheng, The crystal structure of Tricinic Mangano-astrophyllite (in Russian), Scientia Sinica (Scien-ce in China), 1964, 13(7): 1180-1183.[5]Shi Nicheng, Ma Zhesheng, Li Guowu et al., Stucyure Refinement of Monoclinic astrophyllite, Acta Crystallographica, Section B, 1998, B54: 109-114.[6]Woodrow, P. J., The Crystal structure of astrophyllite, Acta Crystallographica, 1967, 22: 673-678.[7]СеменовЕ. И., Куплетскит-Новый Минерал Группы Астрофиллита, ДАН, 1956, 108(5), 933-936.[8]Nickel, E. H., Rowland, J. E., Charette, D. J., Niobophyllite the niobium analogue of astrophyllite: A new mineral from Sead Laxe Labrador, Canad. Mine., 1964, 8(1): 40.[9]X-Ray Laboratory of Hubei Geologic College, The crystal chemistry of astrophyllite group minerals (in Chinese), Scientia Geologica Sinica, 1974, (1): 18-30.[10]Sheldrick, G. M., Program for the solution of crystal structures, SHELX86, University of G?ttingen, 1985, Germany.[11]Sheldrick, G. M., Program for the refinement of crystal structures, SHELXL93, University of G?ttingen, 1993, Germany.[12]Liebau, F., Structural Chemistry of Silicates Structure, Bonding, and Classification, Heidelberg: Springer-Verlag QD181, S6L614, 1985.[13]Ferraris, G., Ivaldi, G., Khomyakov, A. P. et al., Nafertisite, a layer titanosilicate member of a polysomatic series including mica, Eur. J. Mineral.,1996, 8: 241-249.[14]Ferraris, G., Polysomatism as a tool for correlating properties and structure, in EMU Notes in

  10. Robustness of Structural Systems

    DEFF Research Database (Denmark)

    Canisius, T.D.G.; Sørensen, John Dalsgaard; Baker, J.W.

    2007-01-01

    The importance of robustness as a property of structural systems has been recognised following several structural failures, such as that at Ronan Point in 1968,where the consequenceswere deemed unacceptable relative to the initiating damage. A variety of research efforts in the past decades have...... systems. Guidance is provided regarding the assessment of robustness in a framework that considers potential hazards to the system, vulnerability of system components, and failure consequences. Several proposed methods for quantifying robustness are reviewed, and guidelines for robust design...

  11. Safety of Marine Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.

    1990-01-01

    of a "future safe" design code for exposed marine structures like breakwaters should be different from the ones usually applied in modern design standards for conventional structures within civil engineering. Moreover, results from ongoing development of a design code for rubble mound breakwaters are presented.......Based on the large number of recent failures of major rubble mound breakwaters the paper discusses the experience gained so far and points out the weak spots in our present knowledge. On this base the difficulties in developing design standards are discussed and it is argued that the principles...

  12. Coastal Structures and Barriers 2012

    Data.gov (United States)

    California Department of Resources — This dataset is a compilation of the UCSC Sand Retention Structures, MC Barriers, and USACE Coastal Structures. UCSC Sand Retention Structures originate from a...

  13. System Reliability of Timber Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

    2010-01-01

    For reduction of the risk of collapse in the event of loss of structural element(s), a structural engineer may take necessary steps to design a collapse-resistant structure that is insensitive to accidental circumstances e.g. by incorporating characteristics like redundancy, ties, ductility, key ...... elements, alternate load path(s) etc. in the structural design. In general these characteristics can have a positive influence on system reliability of a structure however, in Eurocodes ductility is only awarded for concrete and steel structures but not for timber structures. It is well......-know that structural systems can redistribute internal forces due to ductility of a connection, i.e. some additional loads can be carried by the structure. The same effect is also possible for reinforced concrete structures and structures of steel. However, for timber structures codes do not award that ductility...

  14. Coastal Structures and Barriers 2012

    Data.gov (United States)

    California Department of Resources — This dataset is a compilation of the UCSC Sand Retention Structures, MC Barriers, and USACE Coastal Structures. UCSC Sand Retention Structures originate from a...

  15. Integrated materials–structural models

    DEFF Research Database (Denmark)

    Stang, Henrik; Geiker, Mette Rica

    2008-01-01

    Reliable service life models for load carrying structures are significant elements in the evaluation of the performance and sustainability of existing and new structures. Furthermore, reliable service life models are prerequisites for the evaluation of the sustainability of maintenance strategies......, repair works and strengthening methods for structures. A very significant part of the infrastructure consists of reinforced concrete structures. Even though reinforced concrete structures typically are very competitive, certain concrete structures suffer from various types of degradation. A framework...

  16. Robustness Analysis of Kinetic Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

    2009-01-01

    The present paper considers robustness of kinetic structures. Robustness of structures has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. Especially for these types of structural syst...... systems, it is of interest to investigate how robust the structures are, or what happens if a structural element is added to or removed from the original structure. The present paper discusses this issue for kinetic structures in architecture....

  17. Market structures in international telecommunications

    DEFF Research Database (Denmark)

    Henten, Anders

    1998-01-01

    Paper dealing with the internationalisation of telecommunications and the developing market structures.......Paper dealing with the internationalisation of telecommunications and the developing market structures....

  18. Organisational Structures & Considerations

    NARCIS (Netherlands)

    Luiijf, H.A.M.; Healey, J.

    2012-01-01

    The purpose of this section is to review specific types of national cyber security (NCS) areas (also called ‘mandates’) and examine the organisational and collaborative models associated with them. Before discussing the wide variety of organisational structures at the national and international leve

  19. Structure from interaction events

    NARCIS (Netherlands)

    de Nooy, W.

    2015-01-01

    In this contribution to the colloquium, I argue why and how I lost interest in the overall structure of social networks even though Big Data techniques are increasingly simplifying the collection, organisation, and analysis of ever larger networks. The challenge that Big Data techniques pose to the

  20. Teaching concrete structures

    DEFF Research Database (Denmark)

    Goltermann, Per

    2014-01-01

    The teaching of concrete structures has been revised and a number of new approaches have been developed, implemented and evaluated. Inductive teaching, E-learning and “patches” have been found to be improvements and may be an inspiration and help for others development of the teaching and learning...

  1. Nanoscale Turing structures

    DEFF Research Database (Denmark)

    Dziekan, Piotr; Hansen, Jesper Schmidt; Nowakowski, Bogdan

    2014-01-01

    Formation of Turing patterns of nanoscopic length scale is simulated using molecular dynamics. Based on Fourier spectra of the concentrations of species, we compare stabilities of the structures of different wavelengths and for different intermolecular potentials. Long range attraction is shown t...

  2. Capital Structure and Assets

    DEFF Research Database (Denmark)

    Flor, Christian Riis

    2008-01-01

    post optimally sell the assets or re-optimize the capital structure. Ex ante, more uncertain asset value decreases leverage, but not firm value, and selling the assets becomes less likely. Firms should tend to invest in assets whose value is less correlated to changes in earnings and, in addition...

  3. Reliability based structural design

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2014-01-01

    According to ISO 2394, structures shall be designed, constructed and maintained in such a way that they are suited for their use during the design working life in an economic way. To fulfil this requirement one needs insight into the risk and reliability under expected and non-expected actions. A ke

  4. Reliability based structural design

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2013-01-01

    According to ISO 2394, structures shall be designed, constructed and maintained in such a way that they are suited for their use during the design working life in an economic way. To fulfil this requirement one needs insight into the risk and reliability under expected and non-expected actions. A ke

  5. Secondary Structure Switch

    Science.gov (United States)

    King, Angela G.

    2006-01-01

    Neurogenerative diseases like Alzheimer's disease and Parkinson's disease involve a transformation between two peptide and protein structures of alpha-helices and beta-sheets, where the peptide backbone can also participate in metal ion binding in addition to histidine residues. However, the complete absence of change in conformation of Coiled…

  6. Structure - materials - production

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders; Gammel, Peder; Busch, Jens

    2002-01-01

    For the last six years th Aarhus School of Architecture has introduced the first year students (there are about 200 students admitted each year) to structure, materials, design and production through a five week course in collaboration with a group of local companies....

  7. The Structure of Pectin

    Energy Technology Data Exchange (ETDEWEB)

    Mort, Andrew [Oklahoma State Univ., Stillwater, OK (United States). Dept. of Biochemistry and Molecular Biology

    2017-01-12

    At the beginning of this project we hypothesized that pectin, which is a major polysaccharide in primary plant cell walls, is composed of various distinct structural regions covalently linked together into a high molecular weight complex polymer. We also hypothesized that a considerable portion of xyloglucan, the major hemicellulose in most primary cell walls, is linked to the pectin. Our goal was to determine if these interconnections exist and to characterize the exact nature of the interactions. It seems imperative that we have a complete knowledge of the structure of pectin to be able to propose realistic models of cell walls. There is a lot of interest in the biosynthesis of pectin. I do not think it will be possible to completely understand the biosynthesis of pectin without knowing the structure of pectin and thus the sequence of reactions needed to put each sugar or ester in its correct position in the polymer. We made considerable progress in determining the detailed structure of pectin and within a year or so will be able to put forward a comprehensive model of it.

  8. Large, Easily Deployable Structures

    Science.gov (United States)

    Agan, W. E.

    1983-01-01

    Study of concepts for large space structures will interest those designing scaffolding, radio towers, rescue equipment, and prefabricated shelters. Double-fold, double-cell module was selected for further design and for zero gravity testing. Concept is viable for deployment by humans outside space vehicle as well as by remotely operated manipulator.

  9. Inequalities in network structures

    NARCIS (Netherlands)

    Whitmeyer, Joseph M.; Wittek, Rafael

    We use a model of continuous attachments in networks to generate propositions concerning inequalities in network structures, and test the propositions on data from organizational settings. Our network model, inspired by that of [Gould, Roger 2002. The origins of status hierarchies: A formal theory

  10. Mining Structured Data

    NARCIS (Netherlands)

    Nijssen, Siegfried Gerardus Remius

    2006-01-01

    Many databases do not consist of a single table of fixed dimensions, but of objects that are related to each other: the databases are relational, or structured. We study the discovery of patterns in such data. In our approach, a data analyst specifies constraints on patterns that she believes to be

  11. Land, Structure & Depreciation

    NARCIS (Netherlands)

    M. Francke; A. van de Minne

    2013-01-01

    We introduce a hedonic price model which enables us to disentangle the value of a residential property into the value of land and the value of structure, while controlling for depreciation and vintage effects. For given reconstruction costs we are able to estimate the impact of physical depreciation

  12. Visual Narrative Structure

    Science.gov (United States)

    Cohn, Neil

    2013-01-01

    Narratives are an integral part of human expression. In the graphic form, they range from cave paintings to Egyptian hieroglyphics, from the Bayeux Tapestry to modern day comic books (Kunzle, 1973; McCloud, 1993). Yet not much research has addressed the structure and comprehension of narrative images, for example, how do people create meaning out…

  13. Structured Programming: An Introduction.

    Science.gov (United States)

    Moulton, Peter

    Designed for use by computer programming teachers, this booklet presents the concepts of structured programming and provides examples of how to implement this methodology, which provides a systematic way of organizing programs so that even large and complex programs are easier to understand and modify than unstructured programs. After a brief…

  14. Structural Equation Model Trees

    Science.gov (United States)

    Brandmaier, Andreas M.; von Oertzen, Timo; McArdle, John J.; Lindenberger, Ulman

    2013-01-01

    In the behavioral and social sciences, structural equation models (SEMs) have become widely accepted as a modeling tool for the relation between latent and observed variables. SEMs can be seen as a unification of several multivariate analysis techniques. SEM Trees combine the strengths of SEMs and the decision tree paradigm by building tree…

  15. Air Structures: Inflatable Alternatives

    Science.gov (United States)

    Valerio, Joseph M.; And Others

    1973-01-01

    Describes and evaluates several avant garde'' examples of air structures. Included are a soft'' child's playpen, a pneudome that employs a water ballast for anchoring, a one-acre enclosed campus, an instant city'' constructed for an industrial design conference, and the Fuji Pavilion, at Expo '70 in Osaka, Japan, that was large enough to cover…

  16. Structuring the Information Gap.

    Science.gov (United States)

    Edge, Julian

    1984-01-01

    Describes an information gap procedure to teach a new structure which requires students to look for and exchange information in order to complete a task in an English as a second language class. Illustrates the method with a set of materials and suggests ways for teachers to produce similar materials. (SED)

  17. Whence Structured Propositions?

    Science.gov (United States)

    Keller, Lorraine Juliano

    2012-01-01

    This thesis is a critical examination of "Structured Propositionalism" (SP), the view that propositions are complex entities composed of the semantic values of the (meaningful) parts of the sentences that express them. According to SP, propositions have constituents and are individuated by the identity and arrangement of their…

  18. Hybrid composite laminate structures

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F. (Inventor)

    1977-01-01

    An invention which relates to laminate structures and specifically to essentially anisotropic fiber composite laminates is described. Metal foils are selectively disposed within the laminate to produce increased resistance to high velocity impact, fracture, surface erosion, and other stresses within the laminate.

  19. Manipulating Combinatorial Structures.

    Science.gov (United States)

    Labelle, Gilbert

    This set of transparencies shows how the manipulation of combinatorial structures in the context of modern combinatorics can easily lead to interesting teaching and learning activities at every level of education from elementary school to university. The transparencies describe: (1) the importance and relations of combinatorics to science and…

  20. Corporate strategies: organizational structure.

    Science.gov (United States)

    Howe, R C; Oestreicher, V

    1988-06-01

    In previous installments of this series, the authors outlined factors that influence corporation information system strategies. The factor that appears to be most significant is centralization vs. decentralization. This article presents examples of organizational structures, roles and responsibilities for either approach.

  1. Unsupervised Knowledge Structuring

    DEFF Research Database (Denmark)

    Kano Glückstad, Fumiko; Herlau, Tue; Schmidt, Mikkel N.;

    2013-01-01

    This work presents a conceptual framework for learning an ontological structure of domain knowledge, which combines Jaccard similarity coefficient with the Infinite Relational Model (IRM) by (Kemp et al. 2006) and its extended model, i.e. the normal-Infinite Relational Model (n-IRM) by (Herlau et...

  2. Multilevel distributed structure optimization

    NARCIS (Netherlands)

    Entzinger, J.O.; Spallino, R.; Ruijter, W.

    2003-01-01

    An iterative optimisation routine for aircraft structures using Genetic Algorithms (GAs) and Neural Networks (NNs) is presented. In this setup the NNs form a response surface, approximating the key mechanical properties of substructures. NNs are updated every iteration. The GA uses these NNs in the

  3. Reforming Organizational Structures

    NARCIS (Netherlands)

    S.G.J. Van de Walle (Steven)

    2016-01-01

    textabstractPublic sectors have undergone major transformations. Public sector reform touches upon the core building blocks of the public sector: organizational structures, people and finances. These are objects of reform. This chapter presents and discusses a set of major transformations with

  4. Probabilistic Structural Analysis Program

    Science.gov (United States)

    Pai, Shantaram S.; Chamis, Christos C.; Murthy, Pappu L. N.; Stefko, George L.; Riha, David S.; Thacker, Ben H.; Nagpal, Vinod K.; Mital, Subodh K.

    2010-01-01

    NASA/NESSUS 6.2c is a general-purpose, probabilistic analysis program that computes probability of failure and probabilistic sensitivity measures of engineered systems. Because NASA/NESSUS uses highly computationally efficient and accurate analysis techniques, probabilistic solutions can be obtained even for extremely large and complex models. Once the probabilistic response is quantified, the results can be used to support risk-informed decisions regarding reliability for safety-critical and one-of-a-kind systems, as well as for maintaining a level of quality while reducing manufacturing costs for larger-quantity products. NASA/NESSUS has been successfully applied to a diverse range of problems in aerospace, gas turbine engines, biomechanics, pipelines, defense, weaponry, and infrastructure. This program combines state-of-the-art probabilistic algorithms with general-purpose structural analysis and lifting methods to compute the probabilistic response and reliability of engineered structures. Uncertainties in load, material properties, geometry, boundary conditions, and initial conditions can be simulated. The structural analysis methods include non-linear finite-element methods, heat-transfer analysis, polymer/ceramic matrix composite analysis, monolithic (conventional metallic) materials life-prediction methodologies, boundary element methods, and user-written subroutines. Several probabilistic algorithms are available such as the advanced mean value method and the adaptive importance sampling method. NASA/NESSUS 6.2c is structured in a modular format with 15 elements.

  5. GKZ Hypergeometric Structures

    NARCIS (Netherlands)

    Stienstra, J.

    2007-01-01

    This text is based on lectures by the author in the Summer School Algebraic Geometry and Hypergeometric Functions in Istanbul in June 2005. It gives a review of some of the basic aspects of the theory of hypergeometric structures of Gelfand, Kapranov and Zelevinsky, including Differential Equations,

  6. Cell Structure Study.

    Science.gov (United States)

    Ekstrom, James V.

    2000-01-01

    Presents an activity in which students use microscopes and digital images to examine Elodea, a fresh water plant, before and after the process of plasmolysis, identify plant cellular structures before and after plasmolysis, and calculate the size of the plant's vacuole. (ASK)

  7. Silicon Betavoltaic Batteries Structures

    Directory of Open Access Journals (Sweden)

    V.N. Murashev

    2015-12-01

    Full Text Available For low-power miniature energy creation sources the particular interest is nickel Ni63. This paper discusses the main types of betavoltaic battery structures with the prospects for industrial application using - isotope of nickel Ni63. It is shown that the prospects for improving the effective efficiency are planar multijunction betavoltaic batteries.

  8. Magnetic Structure of Erbium

    DEFF Research Database (Denmark)

    Gibbs, D.; Bohr, Jakob; Axe, J. D.

    1986-01-01

    , and at positions split symmetrically about the fundamental. As the temperature is lowered below 52 K the charge and magnetic scattering display a sequence of lock-in transitions to rational wave vectors. A spin-slip description of the magnetic structure is presented which explains the wave vectors...

  9. Space-time structure

    CERN Document Server

    Schrödinger, Erwin

    1985-01-01

    In response to repeated requests this classic book on space-time structure by Professor Erwin Schrödinger is now available in the Cambridge Science Classics series. First published in 1950, and reprinted in 1954 and 1960, this lucid and profound exposition of Einstein's 1915 theory of gravitation still provides valuable reading for students and research workers in the field.

  10. Verification of ceramic structures

    NARCIS (Netherlands)

    Behar-Lafenetre, S.; Cornillon, L.; Rancurel, M.; Graaf, D. de; Hartmann, P.; Coe, G.; Laine, B.

    2012-01-01

    In the framework of the "Mechanical Design and Verification Methodologies for Ceramic Structures" contract [1] awarded by ESA, Thales Alenia Space has investigated literature and practices in affiliated industries to propose a methodological guideline for verification of ceramic spacecraft and instr

  11. Structured Mechanical Collage.

    Science.gov (United States)

    Huang, Zhe; Wang, Jiang; Fu, Hongbo; Lau, Rynson W H

    2014-07-01

    We present a method to build 3D structured mechanical collages consisting of numerous elements from the database given artist-designed proxy models. The construction is guided by some graphic design principles, namely unity, variety and contrast. Our results are visually more pleasing than previous works as confirmed by a user study.

  12. Information Structure: Afterword

    Directory of Open Access Journals (Sweden)

    Craige Roberts

    2012-12-01

    Full Text Available This is the afterword to the 2012 republication of "Information structure in discourse: Towards an integrated formal theory of pragmatics". See also the annotated bibliography on related topics at http://www.ling.ohio-state.edu/~croberts/QUDbib/. http://dx.doi.org/10.3765/sp.5.7 BibTeX info

  13. Inequalities in network structures

    NARCIS (Netherlands)

    Whitmeyer, Joseph M.; Wittek, Rafael

    2010-01-01

    We use a model of continuous attachments in networks to generate propositions concerning inequalities in network structures, and test the propositions on data from organizational settings. Our network model, inspired by that of [Gould, Roger 2002. The origins of status hierarchies: A formal theory a

  14. Communications Policies and Structures.

    Science.gov (United States)

    Pigeat, Henri; And Others

    These two papers discuss communications policies and structures in France and in the United States. The first paper reports that efforts to develop new electronic communication systems in France are hindered by rivalry between two public monopolies and by governmental protection against foreign influence. The second paper assesses ownership of…

  15. Capital Structure and Assets

    DEFF Research Database (Denmark)

    Flor, Christian Riis

    2008-01-01

    post optimally sell the assets or re-optimize the capital structure. Ex ante, more uncertain asset value decreases leverage, but not firm value, and selling the assets becomes less likely. Firms should tend to invest in assets whose value is less correlated to changes in earnings and, in addition...

  16. Nature teaching structures

    DEFF Research Database (Denmark)

    Wester, Ture

    2002-01-01

    If one is looking for an example of a conceptual design which is extremely appropriate in its morphology, well adapted to the surroundings, structurally and functionally optimised, and has a refined and appropriate appearance - all in one single configuration - you have either an exceptional and ...

  17. Structural analysis for Diagnosis

    DEFF Research Database (Denmark)

    Izadi-Zamanabadi, Roozbeh; Blanke, M.

    2001-01-01

    Aiming at design of algorithms for fault diagnosis, structural analysis of systems offers concise yet easy overall analysis. Graph-based matching, which is the essential technique to obtain redundant information for diagnosis, is re-considered in this paper. Matching is re-formulated as a problem...

  18. Structural analysis for diagnosis

    DEFF Research Database (Denmark)

    Izadi-Zamanabadi, Roozbeh; Blanke, M.

    2002-01-01

    Aiming at design of algorithms for fault diagnosis, structural analysis of systems offers concise yet easy overall analysis. Graph-based matching, which is the essential tech-nique to obtain redundant information for diagnosis, is reconsidered in this paper. Matching is reformulated as a problem...

  19. LUTE telescope structural design

    Science.gov (United States)

    Ruthven, Gregory

    1993-01-01

    The major objective of the Lunar Ultraviolet Transit Experiment (LUTE) Telescope Structural Design Study was to investigate the feasibility of designing an ultralightweight 1-m aperture system within optical performance requirements and mass budget constraints. This study uses the results from our previous studies on LUTE as a basis for further developing the LUTE structural architecture. After summarizing our results in Section 2, Section 3 begins with the overall logic we used to determine which telescope 'structural form' should be adopted for further analysis and weight estimates. Specific telescope component analysis showing calculated fundamental frequencies and how they compare with our derived requirements are included. 'First-order' component stress analyses to ensure telescope optical and structural component (i.e. mirrors & main bulkhead) weights are realistic are presented. Layouts of both the primary and tertiary mirrors showing dimensions that are consistent with both our weight and frequency calculations also form part of Section 3. Section 4 presents our calculated values for the predicted thermally induced primary-to-secondary mirror despace motion due to the large temperature range over which LUTE must operate. Two different telescope design approaches (one which utilizes fused quartz metering rods and one which assumes the entire telescope is fabricated from beryllium) are considered in this analysis. We bound the secondary mirror focus mechanism range (in despace) based on these two telescope configurations. In Section 5 we show our overall design of the UVTA (Ultraviolet Telescope Assembly) via an 'exploded view' of the sub-system. The 'exploded view' is annotated to help aid in the understanding of each sub-assembly. We also include a two view layout of the UVTA from which telescope and telescope component dimensions can be measured. We conclude our study with a set of recommendations not only with respect to the LUTE structural architecture

  20. Titanium honeycomb structure. [for supersonic aircraft wing structure

    Science.gov (United States)

    Davis, R. A.; Elrod, S. D.; Lovell, D. T.

    1972-01-01

    A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks.

  1. The Meaning of Surface Structure and Deep Structure to Translation

    Institute of Scientific and Technical Information of China (English)

    罗源

    2014-01-01

    Surface structure and deep structure first come up with by Chomsky is an innovative action in linguistics. Despite the arguments involved around surface structure and deep structure, it is instructional to English-Chinese translation to some degree and its scientific connotation is meaningful to deepen language study and construct related disciplinary both in theory and practice.

  2. Soil Retaining Structures: Development of models for structural analysis

    NARCIS (Netherlands)

    Bakker, K.J.

    2000-01-01

    The topic of this thesis is the development of models for the structural analysis of soil retaining structures. The soil retaining structures being looked at are; block revetments, flexible retaining walls and bored tunnels in soft soil. Within this context typical structural behavior of these struc

  3. Analysis of Pumphouse RCC Frame Structure for Soil Structure Interaction

    Directory of Open Access Journals (Sweden)

    Mr A.S. Thombare

    2016-06-01

    Full Text Available When structure is built on ground some elements of structure are direct contact with soil. When loads are applied on structure internal forces are developed in both the structure as well as in soil. It results in deformation of both the components which are independent to each other. This are called soil structure interaction. The analysis is done by using (Bentley STAAD.Pro V8i Version 2007 software. The analysis carried out been pump house structure R.C.C. frame structure find out shear force Z direction fixed support and fixed but support for different soil. It concluded that soil structure interaction more affected on fixed base. So overcome the effects of the soil structure interaction on the soft soil, it is important to design the structure to standard loading condition and interaction forces. Thus here concluded that pump house building should be design resist the maximum shear force in fixed base

  4. Rigid collapsible dish structure

    Science.gov (United States)

    Palmer, William B. (Inventor); Giebler, Martin M. (Inventor)

    1982-01-01

    A collapsible dish structure composed of a plurality of rows of rigid radial petal assemblies concentric with the axis of the dish. The petal assemblies consist of a center petal and two side petals, the center petal hinged on an axis tangent to a circle concentric with the axis of the dish and the side petals hinged to the center petal at their mating edge. The center petal is foldable inwardly and the side petals rotate about their hinges such that the collapsed dish structure occupies a much smaller volume than the deployed dish. Means of controlling the shape of the dish to compensate for differential expansion of the deployed dish are also provided.

  5. Integrated Structural Design Education

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Almegaard, Henrik

    2011-01-01

    In Environmental Impact Assessment (EIA), the environment is broadly defined and includes not only quantifiable aspects, but also social conditions, scenic beauty, traffic, cultural heritage, and commercial development. A successful bridge design must comply with all of these demands according to...... of a project, function well in design teams, and comply with EU EIA demands.......In Environmental Impact Assessment (EIA), the environment is broadly defined and includes not only quantifiable aspects, but also social conditions, scenic beauty, traffic, cultural heritage, and commercial development. A successful bridge design must comply with all of these demands according...... landscaping and structural design. The integrated courses create a setting for learning about the design of large-scale structures and involve geometry, statics, computer simulation, graphical design and landscape architecture. Together, they educate engineers who can take part in the early design phases...

  6. Sparse structure regularized ranking

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-04-17

    Learning ranking scores is critical for the multimedia database retrieval problem. In this paper, we propose a novel ranking score learning algorithm by exploring the sparse structure and using it to regularize ranking scores. To explore the sparse structure, we assume that each multimedia object could be represented as a sparse linear combination of all other objects, and combination coefficients are regarded as a similarity measure between objects and used to regularize their ranking scores. Moreover, we propose to learn the sparse combination coefficients and the ranking scores simultaneously. A unified objective function is constructed with regard to both the combination coefficients and the ranking scores, and is optimized by an iterative algorithm. Experiments on two multimedia database retrieval data sets demonstrate the significant improvements of the propose algorithm over state-of-the-art ranking score learning algorithms.

  7. Resource Structuring and Ambidexterity

    DEFF Research Database (Denmark)

    Ma, Yucheng; Li, Peter Ping

    -shaped effect on organizational ambidexterity in new ventures. Further, because of the traditional culture and economic transition characteristics, new ventures actively leverage managerial ties as key social relations to obtain special resources or nurture business transactions. We propose that ties with other......Focusing on how resource structuring mechanisms and managerial ties influence organizational ambidexterity of new ventures in emerging economy, this study explores the effects of resource structuring mechanisms (i.e., resource acquiring and resource accumulating) on organizational ambidexterity....... It further examines the moderating effects of managerial ties, (i.e., ties with other firms and ties with the government) on the above relationships. Survey data from China¡¯s 202 new ventures demonstrates that the resource acquiring has an inverted U-shaped effect whereas the resource accumulating has a U...

  8. Structural and Material Instability

    DEFF Research Database (Denmark)

    Cifuentes, Gustavo Cifuentes

    This work is a small contribution to the general problem of structural and material instability. In this work, the main subject is the analysis of cracking and failure of structural elements made from quasi-brittle materials like concrete. The analysis is made using the finite element method. Three...... use of interface elements) is used successfully to model cases where the path of the discontinuity is known in advance, as is the case of the analysis of pull-out of fibers embedded in a concrete matrix. This method is applied to the case of non-straight fibers and fibers with forces that have....... Numerical problems associated with the use of elements with embedded cracks based on the extended finite element method are presented in the next part of this work. And an alternative procedure is used in order to successfully remove these numerical problems. In the final part of this work, a computer...

  9. Diagnosable structured logic array

    Science.gov (United States)

    Whitaker, Sterling (Inventor); Miles, Lowell (Inventor); Gambles, Jody (Inventor); Maki, Gary K. (Inventor)

    2009-01-01

    A diagnosable structured logic array and associated process is provided. A base cell structure is provided comprising a logic unit comprising a plurality of input nodes, a plurality of selection nodes, and an output node, a plurality of switches coupled to the selection nodes, where the switches comprises a plurality of input lines, a selection line and an output line, a memory cell coupled to the output node, and a test address bus and a program control bus coupled to the plurality of input lines and the selection line of the plurality of switches. A state on each of the plurality of input nodes is verifiably loaded and read from the memory cell. A trusted memory block is provided. The associated process is provided for testing and verifying a plurality of truth table inputs of the logic unit.

  10. DNA: Structure and function

    DEFF Research Database (Denmark)

    Sinden, Richard R.; E. Pearson, Christopher; N. Potaman, Vladimir

    1998-01-01

    for a long period of time before its information is accessed by the cell. Although DNA plays a critical role as an informational storage molecule, it is by no means as unexciting as a computer tape or disk drive. The structure of the DNA described by Watson and Crick in 1953 is a right handed helix of two......This chapter discusses the structure and function of DNA. DNA occupies a critical role in cells, because it is the source of all intrinsic genetic information. Chemically, DNA is a very stable molecule, a characteristic important for a macromolecule that may have to persist in an intact form...... individual antiparallel DNA strands. Hydrogen bonds provide specificity that allows pairing between the complementary bases (A.T and G.C) in opposite strands. Base stacking occurs near the center of the DNA helix and provides a great deal of stability to the helix (in addition to hydrogen bonding). The sugar...

  11. Thermally stable deployable structure

    Science.gov (United States)

    Kegg, Colleen M.

    1988-01-01

    A deployable structure which meets stringent thermal and strength requirements in a space environment was developed. A mast with a very low coefficient of thermal expansion (CTE) was required to limit the movement from thermal distortion over the temperature range of -200 C to 80 C to .064 cm (.025 in). In addition, a high bending strength over the temperature range and weight less than 18.1 kg (40 lbs) was needed. To meet all of the requirements, a composite, near-zero CTE structure was developed. The measured average CTE over the temperature range for the mast was .70 x .000001/C (.38 x .000001/F). The design also has the advantage of being adjustable to attain other specific CTE if desired.

  12. Dedicated Deployable Aerobraking Structure

    Science.gov (United States)

    Giersch, Louis R.; Knarr, Kevin

    2010-01-01

    A dedicated deployable aerobraking structure concept was developed that significantly increases the effective area of a spacecraft during aerobraking by up to a factor of 5 or more (depending on spacecraft size) without substantially increasing total spacecraft mass. Increasing the effective aerobraking area of a spacecraft (without significantly increasing spacecraft mass) results in a corresponding reduction in the time required for aerobraking. For example, if the effective area of a spacecraft is doubled, the time required for aerobraking is roughly reduced to half the previous value. The dedicated deployable aerobraking structure thus enables significantly shorter aerobraking phases, which results in reduced mission cost, risk, and allows science operations to begin earlier in the mission.

  13. Generative Moire Structures

    Directory of Open Access Journals (Sweden)

    Adrian – Mihail Marian

    2006-01-01

    Full Text Available “GRAPHIC ON COMPUTER” – the work of the Czech Petar Milojevic, published in Titus Mocanu’s book “THE MODERN ART’S MORPHOLOGY”, in 1973, had great influence on me. I tried to discover the algorithm that generated this work. It was not so difficult to do and in a short time I was able to draw 12 such structures. In time, with interruptions, I have returned to this kind of works. In my personal exhibition “CYBERNETIC DESIGN” that took place at “M4-1-13-etopa” gallery of Pitesti, in March 1981, I have presented 8 such structures. To my joy, they had an impact on art lovers.

  14. Structure of exoplanets

    Science.gov (United States)

    Spiegel, David S.; Fortney, Jonathan J.; Sotin, Christophe

    2014-01-01

    The hundreds of exoplanets that have been discovered in the past two decades offer a new perspective on planetary structure. Instead of being the archetypal examples of planets, those of our solar system are merely possible outcomes of planetary system formation and evolution, and conceivably not even especially common outcomes (although this remains an open question). Here, we review the diverse range of interior structures that are both known and speculated to exist in exoplanetary systems—from mostly degenerate objects that are more than 10× as massive as Jupiter, to intermediate-mass Neptune-like objects with large cores and moderate hydrogen/helium envelopes, to rocky objects with roughly the mass of Earth. PMID:24379369

  15. The Structure of Exoplanets

    CERN Document Server

    Spiegel, David S; Sotin, Christophe

    2013-01-01

    The hundreds of exoplanets that have been discovered in the past two decades offer a new perspective on planetary structure. Instead of being the archetypal examples of planets, those of our Solar System are merely possible outcomes of planetary system formation and evolution, and conceivably not even terribly common outcomes (although this remains an open question). Here, we review the diverse range of interior structures that are known to, and speculated to, exist in exoplanetary systems -- from mostly degenerate objects that are more than 10 times as massive as Jupiter, to intermediate-mass Neptune-like objects with large cores and moderate hydrogen/helium envelopes, to rocky objects with roughly the mass of the Earth.

  16. Structure of exoplanets.

    Science.gov (United States)

    Spiegel, David S; Fortney, Jonathan J; Sotin, Christophe

    2014-09-02

    The hundreds of exoplanets that have been discovered in the past two decades offer a new perspective on planetary structure. Instead of being the archetypal examples of planets, those of our solar system are merely possible outcomes of planetary system formation and evolution, and conceivably not even especially common outcomes (although this remains an open question). Here, we review the diverse range of interior structures that are both known and speculated to exist in exoplanetary systems--from mostly degenerate objects that are more than 10× as massive as Jupiter, to intermediate-mass Neptune-like objects with large cores and moderate hydrogen/helium envelopes, to rocky objects with roughly the mass of Earth.

  17. Introduction to structural chemistry

    CERN Document Server

    Batsanov, Stepan S

    2014-01-01

    A concise description of models and quantitative parameters in structural chemistry and their interrelations, with 280 tables and >3000 references giving the most up-to-date experimental data on energy characteristics of atoms, molecules and crystals (ionisation potentials, electron affinities, bond energies, heats of phase transitions, band and lattice energies), optical properties (refractive index, polarisability), spectroscopic characteristics and geometrical parameters (bond distances and angles, coordination numbers) of substances in gaseous, liquid and solid states, in glasses and melts, for various thermodynamic conditions. Systems of metallic, covalent, ionic and van der Waals radii, effective atomic charges and other empirical and semi-empirical models are critically revised. Special attention is given to new and growing areas: structural studies of solids under high pressures and van der Waals molecules in gases. The book is addressed to researchers, academics, postgraduates and advanced-course stu...

  18. Structure Size Enhanced Histogram

    Science.gov (United States)

    Wesarg, Stefan; Kirschner, Matthias

    Direct volume visualization requires the definition of transfer functions (TFs) for the assignment of opacity and color. Multi-dimensional TFs are based on at least two image properties, and are specified by means of 2D histograms. In this work we propose a new type of a 2D histogram which combines gray value with information about the size of the structures. This structure size enhanced (SSE) histogram is an intuitive approach for representing anatomical features. Clinicians — the users we are focusing on — are much more familiar with selecting features by their size than by their gradient magnitude value. As a proof of concept, we employ the SSE histogram for the definition of two-dimensional TFs for the visualization of 3D MRI and CT image data.

  19. Computation and Spacetime Structure

    CERN Document Server

    Stannett, Mike

    2011-01-01

    We investigate the relationship between computation and spacetime structure, focussing on the role of closed timelike curves (CTCs) in promoting computational speedup. We note first that CTC traversal can be interpreted in two distinct ways, depending on ones understanding of spacetime. Focussing on one interpretation leads us to develop a toy universe in which no CTC can be traversed more than once, whence no computational speedup is possible. Focussing on the second (and more standard) interpretation leads to the surprising conclusion that CTCs act as perfect information repositories: just as black holes have entropy, so do CTCs. If we also assume that P is not equal to NP, we find that all observers agree that, even if unbounded time travel existed in their youth, this capability eventually vanishes as they grow older. Thus the computational assumption "P is not NP" is also an assumption concerning cosmological structure.

  20. Simulating Cosmic Structure Formation

    CERN Document Server

    Weinberg, D H; Hernquist, L E; Weinberg, David H.; Katz, Neal; Hernquist, Lars

    1997-01-01

    We describe cosmological simulation techniques and their application to studies of cosmic structure formation, with particular attention to recent hydrodynamic simulations of structure in the high redshift universe. Collisionless N-body simulations with Gaussian initial conditions produce a pattern of sheets, filaments, tunnels, and voids that resembles the observed large scale galaxy distribution. Simulations that incorporate gas dynamics and dissipation form dense clumps of cold gas with sizes and masses similar to the luminous parts of galaxies. Models based on inflation and cold dark matter predict a healthy population of high redshift galaxies, including systems with star formation rates of 20 M_{\\sun}/year at z=6. At z~3, most of the baryons in these models reside in the low density intergalactic medium, which produces fluctuating Lyman-alpha absorption in the spectra of background quasars. The physical description of this ``Lyman-alpha forest'' is particularly simple if the absorption spectrum is viewe...

  1. Structural Stator Spacers

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andreasen, Jens H.; Pijanowski, J. M.

    2001-01-01

    This paper presents a powerful new design aspect to reduce acoustic noise and vibration of electro-magnetic origin for electrical machines, by introducing improved slot wedges referred to as "Structural Stator Spacers". These spacers, by using a very stiff dielectric and non magnetic material...... drawbacks usually associated with other noise reduction methods or interdict other noise control methods. Design models and practical prototypes are detailed which are used to verify the effectiveness of the spacers......., a modified shape and small modifications to the stator laminations not only secure the windings and reduce windage losses but also make it possible to increase the stiffness of the stator structure significantly thereby reducing the generation of audible noise. This new method does not incur the significant...

  2. Planetary internal structures

    CERN Document Server

    Baraffe, I; Fortney, J; Sotin, C

    2014-01-01

    This chapter reviews the most recent advancements on the topic of terrestrial and giant planet interiors, including Solar System and extrasolar objects. Starting from an observed mass-radius diagram for known planets in the Universe, we will discuss the various types of planets appearing in this diagram and describe internal structures for each type. The review will summarize the status of theoretical and experimental works performed in the field of equation of states (EOS) for materials relevant to planetary interiors and will address the main theoretical and experimental uncertainties and challenges. It will discuss the impact of new EOS on interior structures and bulk composition determination. We will discuss important dynamical processes which strongly impact the interior and evolutionary properties of planets (e.g plate tectonics, semiconvection) and describe non standard models recently suggested for our giant planets. We will address the case of short-period, strongly irradiated exoplanets and critica...

  3. Structured light scatteroscopy.

    Science.gov (United States)

    Krishnaswamy, Venkataramanan; Elliott, Jonathan T; McClatchy, David M; Barth, Richard J; Wells, Wendy A; Pogue, Brian W; Paulsen, Keith D

    2014-01-01

    A new imaging approach, structured light scatteroscopy (SLS), is demonstrated, which offers rapid wide-field imaging of microscopic morphological variations in bulk tissue surfaces. Elastic scattering of light offers exquisite sensitivity to ultrastructural changes at multiple size scales ranging from nanometers to millimeters, but in bulk tissues the confounding effects of molecular absorption and strong multiple scattering of light often lead to a dramatic reduction in scatter contrast and specificity. It is demonstrated that the SLS using structured high spatial frequency illumination and detection to probe the tissue achieves direct, absorption-independent, high-resolution maps of the scattering response. The scattering response is observed to be dependent on both the wavelength and spatial frequency of choice, indicating a potential for multiscale probing of ultrastructural changes in superficial tissue layers. This methodology can be easily applied in most wide-field imaging systems.

  4. Dynamic Data Structures

    DEFF Research Database (Denmark)

    Tsakalidis, Konstantinos

    We study dynamic data structures for different variants of orthogonal range reporting query problems. In particular, we consider (1) the planar orthogonal 3-sided range reporting problem: given a set of points in the plane, report the points that lie within a given 3-sided rectangle with one....... Dynamic problems like the above arise in various applications of network optimization, VLSI layout design, computer graphics and distributed computing. For the first problem, we present dynamic data structures for internal and external memory that support planar orthogonal 3-sided range reporting queries...... unbounded side, (2) the planar orthogonal range maxima reporting problem: given a set of points in the plane, report the points that lie within a given orthogonal range and are not dominated by any other point in the range, and (3) the problem of designing fully persistent B-trees for external memory...

  5. Optimization of structural shapes

    Science.gov (United States)

    Durelli, A. J.

    1981-04-01

    The direct design of shapes of two dimensional structures, loaded in their plane, within specified design constraints and exhibiting optimum distribution of stresses is studied. Photoelasticity and a large field diffused polariscope is used. The optimization process involves the removal of material (with a hand file or router) from the low stress portions of the hole boundary of the model till an isochromatic fringe coincides with the boundary both on the tensile and compressive segments. Applications are also shown to the design of dove tails and slots in turbine blades and rotors, and to the design of star shaped solid propellant grains for rockets, both for the case of parallel side rays and enlarged tip of rays. The use of other methods, in particular the method using finite elements, to optimize structural forms is discussed.

  6. Multi-functional composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, Anthony C.; Halloran, John; Popovich, Dragan; Rigali, Mark J.; Sutaria, Manish P.; Vaidyanathan, K. Ranji; Fulcher, Michael L.; Knittel, Kenneth L.

    2010-04-27

    Fibrous monolith processing techniques to fabricate multifunctional structures capable of performing more than one discrete function such as structures capable of bearing structural loads and mechanical stresses in service and also capable of performing at least one additional non-structural function.

  7. Multi-functional composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, Anthony C.; Halloran, John; Popovich, Dragan; Rigali, Mark J.; Sutaria, Manish P.; Vaidyanathan, K. Ranji; Fulcher, Michael L.; Knittel, Kenneth L.

    2004-10-19

    Fibrous monolith processing techniques to fabricate multifunctional structures capable of performing more than one discrete function such as structures capable of bearing structural loads and mechanical stresses in service and also capable of performing at least one additional non-structural function.

  8. Space deployable truss structure design

    Science.gov (United States)

    Coyner, J. V., Jr.; Tobey, W. H.

    1981-01-01

    The development status of the deployable box truss structure is summarized. Potential applications for this structural system are described. Structural and component design requirements derived from these applications are discussed. Components of prototype 4.6 m cubes which incorporate graphite/epoxy structural members, fittings, and mechanisms are described. The benefits of the component designs and their respective manufacturing processes are presented.

  9. Combinatorics of γ-Structures

    DEFF Research Database (Denmark)

    Han, Hillary Siwei; Li, Thomas Jiaxian; reidys, Christian

    2014-01-01

    In this paper we study canonical $\\gamma$-structures, a class of RNA pseudoknot structures that plays a key role in the context of polynomial time folding of RNA pseudoknot structures. A $\\gamma$-structure is composed by specific building blocks, that have topological genus less than or equal to ...

  10. Combinatorics of γ-Structures

    DEFF Research Database (Denmark)

    Han, Hillary Siwei; Li, Thomas Jiaxian; reidys, Christian

    2014-01-01

    In this paper we study canonical $\\gamma$-structures, a class of RNA pseudoknot structures that plays a key role in the context of polynomial time folding of RNA pseudoknot structures. A $\\gamma$-structure is composed by specific building blocks, that have topological genus less than or equal...

  11. Homogeneous Clifford structures

    OpenAIRE

    Moroianu, Andrei; Pilca, Mihaela

    2012-01-01

    We give an upper bound for the rank r of homogeneous (even) Clifford structures on compact manifolds of non-vanishing Euler characteristic. More precisely, we show that if r = 2a � b with b odd, then r � 9 for a = 0, r � 10 for a = 1, r � 12 for a = 2 and r � 16 for a � 3. Moreover, we describe the four limiting cases and show that there is exactly one solution in each case.

  12. Structural Analysis Made 'NESSUSary'

    Science.gov (United States)

    2005-01-01

    Everywhere you look, chances are something that was designed and tested by a computer will be in plain view. Computers are now utilized to design and test just about everything imaginable, from automobiles and airplanes to bridges and boats, and elevators and escalators to streets and skyscrapers. Computer-design engineering first emerged in the 1970s, in the automobile and aerospace industries. Since computers were in their infancy, however, architects and engineers during the time were limited to producing only designs similar to hand-drafted drawings. (At the end of 1970s, a typical computer-aided design system was a 16-bit minicomputer with a price tag of $125,000.) Eventually, computers became more affordable and related software became more sophisticated, offering designers the "bells and whistles" to go beyond the limits of basic drafting and rendering, and venture into more skillful applications. One of the major advancements was the ability to test the objects being designed for the probability of failure. This advancement was especially important for the aerospace industry, where complicated and expensive structures are designed. The ability to perform reliability and risk assessment without using extensive hardware testing is critical to design and certification. In 1984, NASA initiated the Probabilistic Structural Analysis Methods (PSAM) project at Glenn Research Center to develop analysis methods and computer programs for the probabilistic structural analysis of select engine components for current Space Shuttle and future space propulsion systems. NASA envisioned that these methods and computational tools would play a critical role in establishing increased system performance and durability, and assist in structural system qualification and certification. Not only was the PSAM project beneficial to aerospace, it paved the way for a commercial risk- probability tool that is evaluating risks in diverse, down- to-Earth application

  13. Plasmonics in buried structures

    OpenAIRE

    Romero, I. T.; García de Abajo, Francisco Javier

    2009-01-01

    We describe plasmon propagation in silica-filled coupled nanovoids fully buried in gold. Propagation bands and band gaps are shown to be tunable through the degree of overlap and plasmon hybridization between contiguous voids. The effect of disorder and fabrication imperfections is thoroughly investigated. Our work explores a novel paradigm for plasmon photonics relying on plasmon modes in metal-buried structures, which can benefit from long propagation distances, cancelation of radiative los...

  14. Lightweight Structure in Text

    Science.gov (United States)

    2002-05-01

    1 1.2 A web page that lists electronic books available for downloading. . . . . . . . . . . 2 1.3 A web page from Yahoo...with some of its structure labeled. 1 2 CHAPTER 1. INTRODUCTION book title year author genre format Figure 1.2: A web page that lists electronic ... books available for downloading. advertisement user date hyperlink Figure 1.3: A web page from Yahoo. method type method name statement

  15. Birefringent phononic structures

    Directory of Open Access Journals (Sweden)

    I. E. Psarobas

    2014-12-01

    Full Text Available Within the framework of elastic anisotropy, caused in a phononic crystal due to low crystallographic symmetry, we adopt a model structure, already introduced in the case of photonic metamaterials, and by analogy, we study the effect of birefringence and acoustical activity in a phononic crystal. In particular, we investigate its low-frequency behavior and comment on the factors which determine chirality by reference to this model.

  16. Dynamic Weighted Data Structures.

    Science.gov (United States)

    1982-06-01

    and Bonnie Hampton, who taught me much more than how to play the cello . Finally, for hours of artistic satisfaction, I thank Johannes Brahms, Ludwig...van "j Beethoven, Igor Stravinsky, Glan-Carlo Menotti, and Johann Sebastian Bach . Dynamic Weighted Data Structures Samuel W. Bent This thesis discusses...34I find It a matter of some difficulty to arrange these cards In a manner suited to my needs.’ I glanced at the cards and noticed each was labelled

  17. Lymphotactin structural dynamics

    OpenAIRE

    Volkman, Brian F.; Liu, Tina Y.; Peterson, Francis C.

    2009-01-01

    Lymphotactin/XCL1, the defining member of the C class of chemokines, undergoes a conformational change that involves the complete restructuring of all stabilizing interactions. Other chemokines are restricted to a single conformation by a pair of conserved disulfide crosslinks, one of which is absent in lymphotactin. This structural interconversion is entirely reversible, and the two-state equilibrium is sensitive to changes in temperature and ionic strength. One species adopts the conserved ...

  18. Foams structure and dynamics

    CERN Document Server

    Cantat, Isabelle; Graner, François; Pitois, Olivier; Höhler, Reinard; Elias, Florence; Saint-Jalmes, Arnaud; Rouyer, Florence

    2013-01-01

    This book is the first to provide a thorough description of all aspects of the physico-chemical properties of foams. It sets out what is known about their structure, their stability, and their rheology. Engineers, researchers and students will find descriptions of all the key concepts, illustrated by numerous applications, as well as experiments and exercises for the reader. A solutions manual for lecturers is available via the publisher's web site.

  19. Photonic bandgap structures

    CERN Document Server

    Marco, Pisco; Antonello, Cutolo

    2012-01-01

    This E-Book covers the research and the development of a novel generation of photonic devices for sensing applications. Key features of this book include a brief review of basic PhCs related design and fabrication concepts, a selection of crossover topics for the development of novel technological platforms for physical, chemical and biological sensing and a description of the main PhCs sensors to date by representing many of the exciting sensing applications that utilize photonic crystal structures.

  20. Crystal Structures of Furazanes

    OpenAIRE

    Klapötke, Thomas; Schmid, Philipp; Stierstorfer, Jörg

    2015-01-01

    Several nitrogen-rich salts of 3-nitramino-4-nitrofurazane and dinitraminoazoxyfurazane were synthesized and characterized by various spectroscopic methods. The crystal structures were determined by low temperature single crystal X-ray diffraction. Moreover the sensitivities toward thermal and mechanical stimuli were determined by differential thermal analysis (DTA) and BAM (Bundesanstalt für Materialforschung und -prüfung) methods. The standard enthalpies of formation were calculated for all...

  1. Discrete computational structures

    CERN Document Server

    Korfhage, Robert R

    1974-01-01

    Discrete Computational Structures describes discrete mathematical concepts that are important to computing, covering necessary mathematical fundamentals, computer representation of sets, graph theory, storage minimization, and bandwidth. The book also explains conceptual framework (Gorn trees, searching, subroutines) and directed graphs (flowcharts, critical paths, information network). The text discusses algebra particularly as it applies to concentrates on semigroups, groups, lattices, propositional calculus, including a new tabular method of Boolean function minimization. The text emphasize

  2. ARMY CYBER STRUCTURE ALIGNMENT

    Science.gov (United States)

    2016-02-16

    USCYBERCOM and insertion of supporting services into the cyber organizational architecture introduced the problem of overlapping command and...the cyber force organizational structure and roles and responsibilities to meet the strategic goals defined by Department of Defense (DoD) and U.S...significantly constrained by internal bureaucratic priorities and organizational cultures that limited the holistic approach required to achieve unity of effort

  3. What determines family structure?

    OpenAIRE

    Blau, David M.; van der Klaauw, Wilbert

    2010-01-01

    We estimate the effects of policy and labor market variables on the fertility, union formation and dissolution, type of union (cohabiting versus married), and partner choices of the NLSY79 cohort of women. These demographic behaviors interact to determine the family structure experienced by the children of these women: living with the biological mother and the married or cohabiting biological father, a married or cohabiting step father, or no man. We find that the average wage rates available...

  4. Hierarchically Structured Electrospun Fibers

    Science.gov (United States)

    2013-01-07

    range of fluorescence could be tuned from yellow-green to blue , making these fibers ideal for micro- and nano-optoelectronic devices [144]. Figure 7...forces. Rapid phase separation of the distorted droplet and energy minimization may lead to the formation of the spider -web-like structure of the fiber...engineering cellularized blood vessels. Biomaterials 2010, 31, 4313–4321. 59. Thorvaldsson, A.; Stenhamre, H.; Gatenholm, P.; Walkenstrom, P

  5. Stereochemistry Structure of Odonicin

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bao Lin; Li, Jin; Tong, Ling [Shaanxi Normal University, Xian (China); Pan, Yuan Jiang [Zhejiang University, Hangzhou (China); Yu, Kai Bei [Academia Sinica, Chengdu (China)

    2004-02-15

    Ent-kaurene diterpenoids have various biological activities, such as antitumor, antibacterial, anti-HIV activities etc. The plant of the genus Isodon used in Chinese traditional medicine is a major source of compounds of this structural class. Our investigations on the bitter diterpenoids constituents of the genus Isodon led to the first isolation of odonicin (1) from the leaves and tender branches of Isodon henryi obtained from Taibai Mountain, Shaanxi Province, P. R. China

  6. 7. Administrative structures.

    Science.gov (United States)

    2014-05-01

    The basic systems of any society rarely can operate independently. Instead, they are dependent and often interdependent upon other entities. Such entities control the resources within their respective systems. Thus, coordination and control agencies require contracts or memoranda of understanding with these entities in order to assure access to the resources required during a crisis. These administrative structures include: (1) governmental institutions and agencies, including the military; (2) intergovernmental organisations; (3) nongovernmental organisations; (4) commercial private sector organisations; and (5) academic institutions. These dependencies create potential barriers to the provision of coordination and control including: (1) the complexity of the administrative structures with which coordination and control must interact; (2) the location of resources; (3) finding responsible person(s); (4) the competence and compatibility; (5) methods of access; (6) payment; (7) contracts and memoranda of understanding; (8) inventories of accessible resources; (9) competition for the mandate, power, and resources; and (10) jealousy. The need for potential interactions between administrative structures requires that agreements for the sharing of resources during crises be reached as part of planning and preparedness. Gaining an understanding of these relationships is an important area for research.

  7. Features and Recursive Structure

    Directory of Open Access Journals (Sweden)

    Kuniya Nasukawa

    2015-01-01

    Full Text Available Based on the cross-linguistic tendency that weak vowels are realized with a central quality such as ə, ɨ, or ɯ, this paper attempts to account for this choice by proposing that the nucleus itself is one of the three monovalent vowel elements |A|, |I| and |U| which function as the building blocks of melodic structure. I claim that individual languages make a parametric choice to determine which of the three elements functions as the head of a nuclear expression. In addition, I show that elements can be freely concatenated to create melodic compounds. The resulting phonetic value of an element compound is determined by the specific elements it contains and by the head-dependency relations between those elements. This concatenation-based recursive mechanism of melodic structure can also be extended to levels above the segment, thus ultimately eliminating the need for syllabic constituents. This approach reinterprets the notion of minimalism in phonology by opposing the string-based flat structure.

  8. Visual narrative structure.

    Science.gov (United States)

    Cohn, Neil

    2013-04-01

    Narratives are an integral part of human expression. In the graphic form, they range from cave paintings to Egyptian hieroglyphics, from the Bayeux Tapestry to modern day comic books (Kunzle, 1973; McCloud, 1993). Yet not much research has addressed the structure and comprehension of narrative images, for example, how do people create meaning out of sequential images? This piece helps fill the gap by presenting a theory of Narrative Grammar. We describe the basic narrative categories and their relationship to a canonical narrative arc, followed by a discussion of complex structures that extend beyond the canonical schema. This demands that the canonical arc be reconsidered as a generative schema whereby any narrative category can be expanded into a node in a tree structure. Narrative "pacing" is interpreted as a reflection of various patterns of this embedding: conjunction, left-branching trees, center-embedded constituencies, and others. Following this, diagnostic methods are proposed for testing narrative categories and constituency. Finally, we outline the applicability of this theory beyond sequential images, such as to film and verbal discourse, and compare this theory with previous approaches to narrative and discourse.

  9. Mycorrhizas and soil structure.

    Science.gov (United States)

    Rillig, Matthias C; Mummey, Daniel L

    2006-01-01

    In addition to their well-recognized roles in plant nutrition and communities, mycorrhizas can influence the key ecosystem process of soil aggregation. Here we review the contribution of mycorrhizas, mostly focused on arbuscular mycorrhizal fungi (AMF), to soil structure at various hierarchical levels: plant community; individual root; and the soil mycelium. There are a suite of mechanisms by which mycorrhizal fungi can influence soil aggregation at each of these various scales. By extension of these mechanisms to the question of fungal diversity, it is recognized that different species or communities of fungi can promote soil aggregation to different degrees. We argue that soil aggregation should be included in a more complete 'multifunctional' perspective of mycorrhizal ecology, and that in-depth understanding of mycorrhizas/soil process relationships will require analyses emphasizing feedbacks between soil structure and mycorrhizas, rather than a uni-directional approach simply addressing mycorrhizal effects on soils. We finish the discussion by highlighting new tools, developments and foci that will probably be crucial in further understanding mycorrhizal contributions to soil structure.

  10. Structural Proteomics of Herpesviruses

    Directory of Open Access Journals (Sweden)

    Baptiste Leroy

    2016-02-01

    Full Text Available Herpesviruses are highly prevalent viruses associated with numerous pathologies both in animal and human populations. Until now, most of the strategies used to prevent or to cure these infections have been unsuccessful because these viruses have developed numerous immune evasion mechanisms. Therefore, a better understanding of their complex lifecycle is needed. In particular, while the genome of numerous herpesviruses has been sequenced, the exact composition of virions remains unknown for most of them. Mass spectrometry has recently emerged as a central method and has permitted fundamental discoveries in virology. Here, we review mass spectrometry-based approaches that have recently allowed a better understanding of the composition of the herpesvirus virion. In particular, we describe strategies commonly used for proper sample preparation and fractionation to allow protein localization inside the particle but also to avoid contamination by nonstructural proteins. A collection of other important data regarding post-translational modifications or the relative abundance of structural proteins is also described. This review also discusses the poorly studied importance of host proteins in herpesvirus structural proteins and the necessity to develop a quantitative workflow to better understand the dynamics of the structural proteome. In the future, we hope that this collaborative effort will assist in the development of new strategies to fight these infections.

  11. Fields with Analytic Structure

    CERN Document Server

    Cluckers, Raf

    2009-01-01

    We present a unifying theory of fields with certain classes of analytic functions, called fields with analytic structure. Both real closed fields and Henselian valued fields are considered. For real closed fields with analytic structure, o-minimality is shown. For Henselian valued fields, both the model theory and the analytic theory are developed. We give a list of examples that comprises, to our knowledge, all principal, previously studied, analytic structures on Henselian valued fields, as well as new ones. The b-minimality is shown, as well as other properties useful for motivic integration on valued fields. The paper is reminiscent of [Denef, van den Dries, "p-adic and real subanalytic sets" Ann. of Math. (2) 128 (1988) 79--138], of [Cohen, Paul J. "Decision procedures for real and p-adic fields" Comm. Pure Appl. Math. 22 (1969) 131--151, and of [Fresnel, van der Put, "Rigid analytic geometry and its applications" Progress in Mathematics, 218 Birkhauser (2004)], and unifies work by van den Dries, Haskell...

  12. STRUCTURED CLINICAL EVALUATION

    Directory of Open Access Journals (Sweden)

    Arabela Maria Barbosa Sampaio

    2014-05-01

    Full Text Available In a world experiencing profound technological and socio-political changes in areas of knowledge and capacity, healthcare can not remain static. A new kind of professional is required, whose practice is based on ethics, scientific standards, integrity, citizenship, and health promotion, who develops skills beyond healthcare, such as decision making, communication,leadership, management, and continuing education. No single method can assess all of these elements (knowledge, skills, and attitudes, and only a combination of methods is able to produce a valid evaluation. An alternative method exists: structured clinical assessments based on observation of "to do, or how to do" that aim to complete this evaluation by focusing attention on the performance of specific skills. In order to broaden the scope of evaluation methods that have been used in health education, this article, a literature review, intends to offer readers an overview of the diverse types of structured clinical evaluation, emphasizing Objective Structured Clinical Examination, the most widely used in Brazil, with a goal of advancing opportunities for health professionals to make use of this evaluative tool.

  13. Hypersonic Materials and Structures

    Science.gov (United States)

    Glass, David E.

    2016-01-01

    Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this presentation is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components.

  14. Circular arc structures

    KAUST Repository

    Bo, Pengbo

    2011-07-01

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

  15. A Molecular–Structure Hypothesis

    OpenAIRE

    Jan C. A. Boeyens

    2010-01-01

    The self-similar symmetry that occurs between atomic nuclei, biological growth structures, the solar system, globular clusters and spiral galaxies suggests that a similar pattern should characterize atomic and molecular structures. This possibility is explored in terms of the current molecular structure-hypothesis and its extension into four-dimensional space-time. It is concluded that a quantum molecule only has structure in four dimensions and that classical (Newtonian) structure, which occ...

  16. Structural Stability of Asteroids

    Science.gov (United States)

    Hirabayashi, Toshi

    This thesis develops a technique for analyzing the internal structure of an irregularly shaped asteroid. This research focuses on asteroid (216) Kleopatra, a few-hundred-kilometer-sized main belt asteroid spinning about its maximum moment of inertia axis with a rotation period of 5.385 hours, to motivate the techniques. While Ostro et al. [117] reported its dog bone-like shape, estimation of its size has been actively discussed. There are at least three different size estimates: Ostro et al., Descamps et al., and Marchis et al. Descamps et al. reported that (216) Kleopatra has satellites and obtained the mass of this object. This research consists of determination of possible failure modes of (216) Kleopatra and its subsequent detailed stress analysis, with each part including an estimation of the internal structure. The first part of this thesis considers the failure mode of Kleopatra and evaluates the size from it. Possible failure modes are modeled as either material shedding from the surface or plastic failure of the internal structure. The surface shedding condition is met when a zero-velocity curve with the same energy level as one of the dynamical equilibrium points attaches to the surface at the slowest spin period, while the plastic failure condition is characterized by extending the theorem by Holsapple (2008) that the yield condition of the averaged stress over the whole volume is identical to an upper bound for global failure. The prime result shows that while surface shedding does not occur at the current spin period and thus cannot result in the formation of the satellites, the neck may be situated near its plastic deformation state. From the failure condition, we also find that the size estimated by Descamps et al. (2011) is the most structurally stable. The second part of this thesis discusses finite element analyses with an assumption of an elastic-perfectly plastic material and a non-associated flow rule. The yield condition is modeled as the

  17. What is a (social) structural explanation?

    OpenAIRE

    Haslanger, Sally

    2015-01-01

    A philosophically useful account of social structure must accommodate the fact that social structures play an important role in structural explanation. But what is a structural explanation? How do structural explanations function in the social sciences? This paper offers a way of thinking about structural explanation and sketches an account of social structure that connects social structures with structural explanation.

  18. Repairs of composite structures

    Science.gov (United States)

    Roh, Hee Seok

    Repair on damaged composite panels was conducted. To better understand adhesively bonded repair, the study investigates the effect of design parameters on the joint strength. The design parameters include bondline length, thickness of adherend and type of adhesive. Adhesives considered in this study were tested to measure their tensile material properties. Three types of adhesively bonded joints, single strap, double strap, and single lap joint were considered under changing bondline lengths, thickness of adherend and type of adhesive. Based on lessons learned from bonded joints, a one-sided patch repair method for composite structures was conducted. The composite patch was bonded to the damaged panel by either film adhesive FM-73M or paste adhesive EA-9394 and the residual strengths of the repaired specimens were compared under varying patch sizes. A new repair method using attachments has been suggested to enhance the residual strength. Results obtained through experiments were analyzed using finite element analysis to provide a better repair design and explain the experimental results. It was observed that the residual strength of the repaired specimen was affected by patch length. Method for rapid repairs of damaged composite structures was investigated. The damage was represented by a circular hole in a composite laminated plate. Pre-cured composite patches were bonded with a quick-curing commercial adhesive near (rather than over) the hole. Tensile tests were conducted on specimens repaired with various patch geometries. The test results showed that, among the methods investigated, the best repair method restored over 90% of the original strength of an undamaged panel. The interfacial stresses in the adhesive zone for different patches were calculated in order to understand the efficiencies of the designs of these patch repairs. It was found that the composite patch that yielded the best strength had the lowest interfacial peel stress between the patch and

  19. Unibody Composite Pressurized Structure

    Science.gov (United States)

    Rufer, Markus; Conger, Robert; Bauer, Thomas; Newman, John

    2013-01-01

    An integrated, generic unibody composite pressurized structure (UCPS) combined with a positive expulsion device (PED), consisting of an elastomeric bladder for monopropellant hydrazine, has been quasi-standardized for spacecraft use. The combination functions as an all-composite, non-metallic, propellant tank with bladder. The integrated UCPS combines several previous innovations - specifically, the linerless, all-composite cryogenic tank technology; all-composite boss; resin formulation; and integrated stringer system. The innovation combines the UCPS with an integrated propellant management device (PMD), the PED or bladder, to create an entirely unique system for in-space use. The UCPS is a pressure vessel that incorporates skirts, stringers, and other structures so that it is both an in-space hydrazine tank, and also a structural support system for a spacecraft in a single, all-composite unit. This innovation builds on the progress in the development of a previous SBIR (Small Business Innovation Research) Phase I with Glenn Research Center and an SBIR III with Johnson Space Center that included the fabrication of two 42-in. (˜107-cm) diameter all-composite cryogenic (LOX and liquid methane) UCPS test tanks for a lunar lander. This Phase II provides hydra zine compatibility testing of the elastomeric bladder, a see-through PED to validate the expulsion process and model, and a complete UCPS-based PED with stringers and skirts that will be used to conduct initial qualification and expulsion tests. This extends the UCPS technology to include hydrazine-based, in-space pro - pulsion applications and can also be used for electric propulsion. This innovation creates a system that, in comparison to the traditional approach, is lower in weight, cost, volume, and production time; is stronger; and is capable of much higher pressures. It also has fewer failure modes, and is applicable to both chemical and electric propulsion systems.

  20. Structural Optimization with Reliability Constraints

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1986-01-01

    During the last 25 years considerable progress has been made in the fields of structural optimization and structural reliability theory. In classical deterministic structural optimization all variables are assumed to be deterministic. Due to the unpredictability of loads and strengths of actual...... structures it is now widely accepted that structural problems are non-deterministic. Therefore, some of the variables have to be modelled as random variables/processes and a reliability-based design philosophy should be used, Comell [1], Moses [2], Ditlevsen [3] and Thoft-Christensen & Baker [ 4......]. In this paper we consider only structures which can be modelled as systems of elasto-plastic elements, e.g. frame and truss structures. In section 2 a method to evaluate the reliability of such structural systems is presented. Based on a probabilistic point of view a modern structural optimization problem...

  1. Scour around coastal structures

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Whiteouse, J. S.; Tørum, A.

    2001-01-01

    This paper summarizes the results of the European Union Marine Science and Technology (EU MAST) III project "Scour Around Coastal Structures" (SCARCOST). The summary is presented under three headings: (1) Introduction; (2) Flow and scour processes with the subheadings: flow and scour processes...... pressures and effective stresses around a bottom seated cylinder; non-linear soil modelling with respect to wave-induced pore pressures and gradients; wave-induced pressures on the bottom for non-linear coastal waves, including also wave kinematics; development of a numerical model (linear soil modelling...

  2. Algorithm for structure constants

    CERN Document Server

    Paiva, F M

    2011-01-01

    In a $n$-dimensional Lie algebra, random numerical values are assigned by computer to $n(n-1)$ especially selected structure constants. An algorithm is then created, which calculates without ambiguity the remaining constants, obeying the Jacobi conditions. Differently from others, this algorithm is suitable even for poor personal computer. ------------- En $n$-dimensia algebro de Lie, hazardaj numeraj valoroj estas asignitaj per komputilo al $n(n-1)$ speciale elektitaj konstantoj de strukturo. Tiam algoritmo estas kreita, kalkulante senambigue la ceterajn konstantojn, obeante kondicxojn de Jacobi. Malsimile al aliaj algoritmoj, tiu cxi tauxgas ecx por malpotenca komputilo.

  3. Evolving production network structures

    DEFF Research Database (Denmark)

    Grunow, Martin; Gunther, H.O.; Burdenik, H.

    2007-01-01

    When deciding about future production network configurations, the current structures have to be taken into account. Further, core issues such as the maturity of the products and the capacity requirements for test runs and ramp-ups must be incorporated. Our approach is based on optimization...... modelling and assigns products and capacity expansions to production sites under the above constraints. It also considers the production complexity at the individual sites and the flexibility of the network. Our implementation results for a large manufacturing network reveal substantial possible cost...

  4. Bridgescaping - Contextual Structural Design

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Almegaard, Henrik

    2011-01-01

    Large-scale infrastructural projects such as bridges used to be the monopoly of engineers. They were designed as – often very beautiful – expressions of how forces work in a structure, guided by the nature of materials and a rational construction process. However, in recent decades politicians...... and investors have discovered ways of getting more from their investments by using such projects to give identity and coherence to an area. This has led to a European tendency for engineers to surrender their design opportunities and let architects take over but it does not have to be so. These projects can...

  5. Probabilistic Structured Predictors

    CERN Document Server

    Vembu, Shankar; Boley, Mario

    2012-01-01

    We consider MAP estimators for structured prediction with exponential family models. In particular, we concentrate on the case that efficient algorithms for uniform sampling from the output space exist. We show that under this assumption (i) exact computation of the partition function remains a hard problem, and (ii) the partition function and the gradient of the log partition function can be approximated efficiently. Our main result is an approximation scheme for the partition function based on Markov Chain Monte Carlo theory. We also show that the efficient uniform sampling assumption holds in several application settings that are of importance in machine learning.

  6. Hydrodynamics around cylindrical structures

    CERN Document Server

    Sumer, B Mutlu

    2006-01-01

    This book discusses the subject of wave/current flow around a cylinder, the forces induced on the cylinder by the flow, and the vibration pattern of slender structures in a marine environment. The primary aim of the book is to describe the flow pattern and the resulting load which develops when waves or current meet a cylinder. Special attention is paid to circular cylinder. The development in the forces is related to the various flow patterns and is discussed in detail. Regular as well as irregular waves are considered, and special cases like wall proximities (pipelines) are also investigated

  7. Structure of algebras

    CERN Document Server

    Albert, A A

    1939-01-01

    The first three chapters of this work contain an exposition of the Wedderburn structure theorems. Chapter IV contains the theory of the commutator subalgebra of a simple subalgebra of a normal simple algebra, the study of automorphisms of a simple algebra, splitting fields, and the index reduction factor theory. The fifth chapter contains the foundation of the theory of crossed products and of their special case, cyclic algebras. The theory of exponents is derived there as well as the consequent factorization of normal division algebras into direct factors of prime-power degree. Chapter VI con

  8. Plasmonics in buried structures.

    Science.gov (United States)

    Romero, I; García de Abajo, F J

    2009-10-12

    We describe plasmon propagation in silica-filled coupled nanovoids fully buried in gold. Propagation bands and band gaps are shown to be tunable through the degree of overlap and plasmon hybridization between contiguous voids. The effect of disorder and fabrication imperfections is thoroughly investigated. Our work explores a novel paradigm for plasmon photonics relying on plasmon modes in metal-buried structures, which can benefit from long propagation distances, cancelation of radiative losses, minimum crosstalk between neighboring waveguides, and maximum optical integration in three-dimensional arrangements.

  9. The Structure of Phenylglycinol

    Science.gov (United States)

    Simao, Alcides; Peña, Isabel; Cabezas, Carlos; Alonso, José L.

    2014-06-01

    The most abundant conformer of the amino alcohol D-phenylglycinol has been observed in gas phase using broadband chirped pulse Fourier transform microwave spectroscopy (CP-FTMW) and laser ablation molecular beam Fourier transform microwave spectroscopy (LA-MB-FTMW). The rotational spectra corresponding to seven monosubstituted 13C, one monosubstituted 15N and one monosubstituted 18O species have been observed in their natural abundance, and the rs structure has been derived. The observed conformer is stabilized by O-H\\cdotsN, N-H\\cdotsπ intramolecular hydrogen bond network.

  10. Structured Multifrontal Sparse Solver

    Energy Technology Data Exchange (ETDEWEB)

    2014-05-01

    StruMF is an algebraic structured preconditioner for the interative solution of large sparse linear systems. The preconditioner corresponds to a multifrontal variant of sparse LU factorization in which some dense blocks of the factors are approximated with low-rank matrices. It is algebraic in that it only requires the linear system itself, and the approximation threshold that determines the accuracy of individual low-rank approximations. Favourable rank properties are obtained using a block partitioning which is a refinement of the partitioning induced by nested dissection ordering.

  11. Dynamical Structure of Baryons

    CERN Document Server

    Aleksejevs, A

    2013-01-01

    Compton scattering offers a unique opportunity to study the dynamical structure of hadrons over a wide kinematic range, with polarizabilities characterizing the hadron active internal degrees of freedom. We present calculations and detailed analysis of electric and magnetic and the spin-dependent dynamical polarizabilities for the lowest in mass SU(3) octet of baryons. These extensive calculations are made possible by the recent implementation of semi-automatized calculations in chiral perturbation theory which allows evaluating polarizabilities from Compton scattering up to next-to-the-leading order. The dependencies for the range of photon energies covering the majority of the meson photoproduction channels are analyzed.

  12. Supersymmetric Optical Structures

    CERN Document Server

    Miri, Mohammad-Ali; El-Ganainy, Ramy; Christodoulides, Demetrios N

    2013-01-01

    We show that supersymmetry can provide a versatile platform in synthesizing a new class of optical structures with desired properties and functionalities. By exploiting the intimate relationship between superpatners, one can systematically construct index potentials capable of exhibiting the same scattering and guided wave characteristics. In particular, in the Helmholtz regime, we demonstrate that one-dimensional supersymmetric pairs display identical reflectivities and transmittivities for any angle of incidence. Optical SUSY is then extended to two-dimensional systems where a link between specific azimuthal mode subsets is established. Finally we explore supersymmetric photonic lattices where discreteness can be utilized to design lossless integrated mode filtering arrangements.

  13. Multifunctional Composite Structures

    Science.gov (United States)

    2010-03-01

    1  I.  INTRODUCTION ...create  the model  is significantly  lower because structured  mesh generation is easily automated.         3 I. INTRODUCTION Composite  materials...specialized materials  such  as  piezoelectric  and  magnetostrictive  materials  that  have  been used to design and build both actuators and sensors

  14. Linac 1, inner structure

    CERN Multimedia

    1968-01-01

    This photo shows the inner structure of Linac 1. As injector to the PS, and later to the Booster, Linac 1 accelerated protons to 50 MeV, but it has also accelerated heavier ions. Fitted with a 520 keV RFQ pre-injector (instead of the original Cockcroft-Walton generator), it delivered protons and heavy ions to LEAR, from 1982 to 1992. After 33 years of faithful service, Linac 1 was dismantled in 1992 to make room for Linac 3 (Pb ions).

  15. Galois module structure

    CERN Document Server

    Snaith, Victor P

    1994-01-01

    Galois module structure deals with the construction of algebraic invariants from a Galois extension of number fields with group G. Typically these invariants lie in the class-group of some group-ring of G or of a related order. These class-groups have "Hom-descriptions" in terms of idèlic-valued functions on the complex representations of G. Following a theme pioneered by A. Frölich, T. Chinburg constructed several invariants whose Hom-descriptions are (conjecturally) given in terms of Artin root numbers. For a tame extension, the second Chinburg invariant is given by the ring of integers, and

  16. Crystal Structures of Furazanes

    Directory of Open Access Journals (Sweden)

    Thomas M. Klapötke

    2015-09-01

    Full Text Available Several nitrogen-rich salts of 3-nitramino-4-nitrofurazane and dinitraminoazoxyfurazane were synthesized and characterized by various spectroscopic methods. The crystal structures were determined by low temperature single crystal X-ray diffraction. Moreover the sensitivities toward thermal and mechanical stimuli were determined by differential thermal analysis (DTA and BAM (Bundesanstalt für Materialforschung und -prüfung methods. The standard enthalpies of formation were calculated for all compounds at the CBS-4M level of theory, and the energetic performance was predicted with the EXPLO5 V6.02 computer code.

  17. Theory of convex structures

    CERN Document Server

    van de Vel, MLJ

    1993-01-01

    Presented in this monograph is the current state-of-the-art in the theory of convex structures. The notion of convexity covered here is considerably broader than the classic one; specifically, it is not restricted to the context of vector spaces. Classical concepts of order-convex sets (Birkhoff) and of geodesically convex sets (Menger) are directly inspired by intuition; they go back to the first half of this century. An axiomatic approach started to develop in the early Fifties. The author became attracted to it in the mid-Seventies, resulting in the present volume, in which graphs appear si

  18. Structure from diffraction methods

    CERN Document Server

    Bruce, Duncan W; Walton, Richard I

    2014-01-01

    Inorganic materials show a diverse range of important properties that are desirable for many contemporary, real-world applications. Good examples include recyclable battery cathode materials for energy storage and transport, porous solids for capture and storage of gases and molecular complexes for use in electronic devices. An understanding of the function of these materials is necessary in order to optimise their behaviour for real applications, hence the importance of 'structure-property relationships'. The chapters presented in this volume deal with recent advances in the characterisatio

  19. Conceptual structures in practice

    CERN Document Server

    Hitzler, Pascal

    2009-01-01

    Exploring fundamental research questions, Conceptual Structures in Practice takes you through the basic yet nontrivial task of establishing conceptual relations as the foundation for research in knowledge representation and knowledge mining. It includes contributions from leading researchers in both the conceptual graph and formal concept analysis (FCA) communities.This accessible, self-contained book begins by providing the formal background in FCA and conceptual graphs. It then describes various software tools for analysis and computation, including the ToscanaJ suite. Written by the origina

  20. Structure Learning in Audio

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch

    and speech, using novel features based on pitch dynamics. Within instrument classification two different harmonic models have been compared. Finally voiced/unvoiced segmentation of popular music is done based on MFCC’s and AR coefficients. The structures in the mixings of multiple sources have been...... investigated. A fast and computationally simple approach that compares recordings and classifies if they are from the same audio environment have been developed, and shows very high accuracy and the ability to synchronize recordings in the case of recording devices which are not connected. A more general model...

  1. Structural Logical Relations

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Sarnat, Jeffrey

    2008-01-01

    , such as Twelf, and yet they are often straightforward in proof assistants with stronger meta-logics. In this paper, we propose structural logical relations as a technique for conducting these proofs in systems with limited meta-logical strength by explicitly representing and reasoning about an auxiliary logic......Tait's method (a.k.a. proof by logical relations) is a powerful proof technique frequently used for showing foundational properties of languages based on typed lambda-calculi. Historically, these proofs have been extremely difficult to formalize in proof assistants with weak meta-logics...

  2. Data structures I essentials

    CERN Document Server

    Smolarski, Dennis C

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Data Structures I includes scalar variables, arrays and records, elementary sorting, searching, linked lists, queues, and appendices of binary notation and subprogram parameter passi

  3. Data structures II essentials

    CERN Document Server

    Smolarski, Dennis C

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Data Structures II includes sets, trees, advanced sorting, elementary graph theory, hashing, memory management and garbage collection, and appendices on recursion vs. iteration, alge

  4. Lightweight Materials and Structures (LMS): Inflatable Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Inflatable Structures (InSTAR) project goal is to demonstrate long term durability of inflatable habitat structures for potential utilization as either in-space...

  5. Bandwidth enhanced electromagnetic bandgap structure structured closed ground monopole antenna

    National Research Council Canada - National Science Library

    Modali S. S. S. SRINIVAS; Tottempudi Venkata RAMAKRISHNA; Boddapati T. P. MADHAV; Sathuluri Venkata RAMA RAO; Shaik ASHRAF ALI

    2016-01-01

    .... To overcome this problem a coplanar wave guide fed square patch monopole antenna with closed ground structure is proposed in this paper and electromagnetic band gap structure is added to the antenna...

  6. Structural ropes development for the E-ELT structure

    Science.gov (United States)

    Pajuelo, Eugenio; Gómez, José Ramón; Ronquillo, Bernardo; Brunetto, Enzo; Koch, Franz

    2008-07-01

    The European Extremely Large Telescope (E-ELT) structural rope system will be integrated in a mechanical structure, which can be made of mild steel and/or composite material. The following critical problems shall be solved by the rope system: matching of differential thermal expansion and tensioning forces calibration and control. The structural rope system consists of ropes, thermal compensation and tension control devices, and mechanical interfaces with the telescope structure. The objective of this study is to provide solutions to stabilize slender structural elements located in the upper part of the E-ELT Altitude Structure and increase global mode frequencies of the upper part of the E-ELT Altitude Structure. An appropriate rope system is developed to avoid local mode shapes and loss of stiffness that could lead to the failure of the whole structure under operational loads. The pre-tension level of the ropes needs to be controlled before operation to reach that objective.

  7. Structure and activation of rhodopsin

    Institute of Scientific and Technical Information of China (English)

    X Edward ZHOU; Karsten MELCHER; H Eric XU

    2012-01-01

    Rhodopsin is the first G-protein-coupled receptor (GPCR) with its three-dimensional structure solved by X-ray crystallography.The crystal structure of rhodopsin has revealed the molecular mechanism of photoreception and signal transduction in the visual system.Although several other GPCR crystal structures have been reported over the past few years,the rhodopsin structure remains an important model for understanding the structural and functional characteristics of other GPCRs.This review summarizes the structural features,the photoactivation,and the G protein signal transduction of rhodopsin.

  8. Structural Pain Compensating Flight Control

    Science.gov (United States)

    Miller, Chris J.

    2014-01-01

    The problem of control command and maneuver induced structural loads is an important aspect of any control system design. Designers must design the aircraft structure and the control architecture to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to build the structure with high margins, restrict control surface commands to known good combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage.

  9. The structures of binary compounds

    CERN Document Server

    Hafner, J; Jensen, WB; Majewski, JA; Mathis, K; Villars, P; Vogl, P; de Boer, FR

    1990-01-01

    - Up-to-date compilation of the experimental data on the structures of binary compounds by Villars and colleagues. - Coloured structure maps which order the compounds into their respective structural domains and present for the first time the local co-ordination polyhedra for the 150 most frequently occurring structure types, pedagogically very helpful and useful in the search for new materials with a required crystal structure. - Crystal co-ordination formulas: a flexible notation for the interpretation of solid-state structures by chemist Bill Jensen. - Recent important advances in unders

  10. Crystal structure of fiber structured pentacene thin films

    OpenAIRE

    2007-01-01

    This PhD thesis presents a technique based on the grazing incidence crystal truncation rod (GI-CTR) X-ray diffraction method used to solve the crystal structure of substrate induced fiber structured organic thin films. The crystal structures of pentacene thin films grown on technologically relevant gate dielectric substrates are reported. It is widely recognized, that the intrinsic charge transport properties in organic thin film transistors (OTFTs) depend strongly on the crystal structur...

  11. Frustrated polymer crystal structures

    Science.gov (United States)

    Lotz, B.; Strasbourg, 67083

    1997-03-01

    Several crystal structures or polymorphs of chiral or achiral polymers and biopolymers with three fold conformation of the helix have been found to conform to a common and -with one exception(Puterman, M. et al, J. Pol. Sci., Pol. Phys. Ed., 15, 805 (1977))- hitherto unsuspected packing scheme. The trigonal unit-cell contains three isochiral helices; the azimuthal setting of one helix differs significantly from that of the other two, leading to a so-called frustrated packing scheme, in which the environment of conformationally identical helices differs. Two variants of the frustrated scheme are analyzed. Similarities with frustrated two dimensional magnetic systems are underlined. Various examples of frustration in polymer crystallography are illustrated via the elucidation or reinterpretation of crystal phases or polymorphs of polyolefins, polyesters, cellulose derivatives and polypeptides. Structural manifestations (including AFM evidence) and morphological consequences of frustration are presented, which help diagnose the existence of this original packing of polymers.(Work done with L. Cartier, D. Dorset, S. Kopp, T. Okihara, M. Schumacher, W. Stocker.)

  12. Crystal structure of fipronil

    Directory of Open Access Journals (Sweden)

    Hyunjin Park

    2017-10-01

    Full Text Available The title compound, C12H4Cl2F6N4OS {systematic name: 5-amino-1-[2,6-dichloro-4-(trifluoromethylphenyl]-4-[(trifluoromethanesulfinyl]-1H-pyrazole-3-carbonitrile}, is a member of the phenylpyrazole group of acaricides, and one of the phenylpyrazole group of insecticides. The dihedral angle between the planes of the pyrazole and benzene rings is 89.03 (9°. The fluorine atoms of the trifluoromethyl substituent on the benzene ring are disordered over two sets of sites, with occupancy ratios 0.620 (15:0.380 (15. In the crystal, C—N...π interactions [N...ring centroid = 3.607 (4 Å] together with N—H...N and C—H...F hydrogen bonds form a looped chain structure along [10\\overline{1}]. Finally, N—H...O hydrogen bonds and C—Cl...π interactions [Cl...ring centroid = 3.5159 (16 Å] generate a three-dimensional structure. Additionally, there are a short intermolecular F... F contacts present.

  13. Lagrange structure and quantization

    Energy Technology Data Exchange (ETDEWEB)

    Kazinski, Peter O. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation); Lyakhovich, Simon L. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation); Sharapov, Alexey A. [Department of Quantum Field Theory, Tomsk State University, Tomsk 634050 (Russian Federation)

    2005-07-01

    A path-integral quantization method is proposed for dynamical systems whose classical equations of motion do not necessarily follow from the action principle. The key new notion behind this quantization scheme is the Lagrange structure which is more general than the lagrangian formalism in the same sense as Poisson geometry is more general than the symplectic one. The Lagrange structure is shown to admit a natural BRST description which is used to construct an AKSZ-type topological sigma-model. The dynamics of this sigma-model in d+1 dimensions, being localized on the boundary, are proved to be equivalent to the original theory in d dimensions. As the topological sigma-model has a well defined action, it is path-integral quantized in the usual way that results in quantization of the original (not necessarily lagrangian) theory. When the original equations of motion come from the action principle, the standard BV path-integral is explicitly deduced from the proposed quantization scheme. The general quantization scheme is exemplified by several models including the ones whose classical dynamics are not variational.

  14. Lagrange structure and quantization

    CERN Document Server

    Kazinski, P O; Sharapov, A A

    2005-01-01

    A path-integral quantization method is proposed for dynamical systems whose classical equations of motion do \\textit{not} necessarily follow from the action principle. The key new notion behind this quantization scheme is the Lagrange structure which is more general than the Lagrangian formalism in the same sense as Poisson geometry is more general than the symplectic one. The Lagrange structure is shown to admit a natural BRST description which is used to construct an AKSZ-type topological sigma-model. The dynamics of this sigma-model in $d+1$ dimensions, being localized on the boundary, are proved to be equivalent to the original theory in $d$ dimensions. As the topological sigma-model has a well defined action, it is path-integral quantized in the usual way that results in quantization of the original (not necessarily Lagrangian) theory. When the original equations of motion come from the action principle, the standard BV path-integral is explicitly deduced from the proposed quantization scheme. The genera...

  15. Silk structure and degradation.

    Science.gov (United States)

    Liu, Bin; Song, Yu-wei; Jin, Li; Wang, Zhi-jian; Pu, De-yong; Lin, Shao-qiang; Zhou, Chan; You, Hua-jian; Ma, Yan; Li, Jin-min; Yang, Li; Sung, K L Paul; Zhang, Yao-guang

    2015-07-01

    To investigate the structure of silk and its degradation properties, we have monitored the structure of silk using scanning electron microscopy and frozen sections. Raw silk and degummed raw silk were immersed in four types of degradation solutions for 156 d to observe their degradation properties. The subcutaneous implants in rats were removed after 7, 14, 56, 84, 129, and 145 d for frozen sectioning and subsequent staining with hematoxylin and eosin (H.E.), DAPI, Beta-actin and Collagen I immunofluorescence staining. The in vitro weight loss ratio of raw silk and degummed raw silk in water, PBS, DMEM and DMEM containing 10% FBS (F-DMEM) were, respectively, 14%/11%, 12.5%/12.9%, 11.1%/14.3%, 8.8%/11.6%. Silk began to degrade after 7 d subcutaneous implantation and after 145 d non-degraded silk was still observed. These findings suggest the immunogenicity of fibroin and sericin had no essential difference. In the process of in vitro degradation of silk, the role of the enzyme is not significant. The in vivo degradation of silk is related to phagocytotic activity and fibroblasts may be involved in this process to secrete collagen. This study also shows the developing process of cocoons and raw silk.

  16. Structural analysis of biodiversity.

    Science.gov (United States)

    Sirovich, Lawrence; Stoeckle, Mark Y; Zhang, Yu

    2010-02-24

    Large, recently-available genomic databases cover a wide range of life forms, suggesting opportunity for insights into genetic structure of biodiversity. In this study we refine our recently-described technique using indicator vectors to analyze and visualize nucleotide sequences. The indicator vector approach generates correlation matrices, dubbed Klee diagrams, which represent a novel way of assembling and viewing large genomic datasets. To explore its potential utility, here we apply the improved algorithm to a collection of almost 17,000 DNA barcode sequences covering 12 widely-separated animal taxa, demonstrating that indicator vectors for classification gave correct assignment in all 11,000 test cases. Indicator vector analysis revealed discontinuities corresponding to species- and higher-level taxonomic divisions, suggesting an efficient approach to classification of organisms from poorly-studied groups. As compared to standard distance metrics, indicator vectors preserve diagnostic character probabilities, enable automated classification of test sequences, and generate high-information density single-page displays. These results support application of indicator vectors for comparative analysis of large nucleotide data sets and raise prospect of gaining insight into broad-scale patterns in the genetic structure of biodiversity.

  17. Investigations of Nuclear Structure

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, Demetrios [Washington Univ., St. Louis, MO (United States); Reviol, W. [Washington Univ., St. Louis, MO (United States)

    2015-07-15

    The proposal addresses studies of nuclear structure at low-energies and development of instrumentation for that purpose. The structure studies deal with features of neutron-rich nuclei with unexplored shapes (football- or pear-shaped nuclei). The regions of interest are: neutron rich nuclei like 132-138Sn, or 48-54Ca, and the Zr, Mo, and Ru isotopes. The tools used can be grouped as follows: either Gammasphere or Gretina multi-gamma detector arrays and auxiliary detectors (Microball, Neutron Shell, and the newly completed Phoswich Wall).The neutron-rich nuclei are accessed by radioactive-beam binary reactions or by 252Cf spontaneous fission. The experiments with heavy radioactive beams aim at exciting the beam nuclei by pick-up or transfer a neutron or a proton from a light target like 13C, 9Be, 11B or 14N .For these binary-reaction studies the Phoswich Wall detector system is essential. It is based on four multi-anode photomultiplier tubes on which CsI and thin fast-timing plastic scintillators are attached. Their signals are digitized with a high density microchip system.

  18. Structural transition metal chemistry

    CERN Document Server

    Anderson, K M

    2002-01-01

    This thesis is divided up into five chapters as outlined below. Chapter 1 gives the background to the techniques used in this thesis including X-ray structure determination and ab initio methods. An overview of some recent studies using ab initio methods to study transition metal complexes is also given. Chapter 2 investigates structural trans influence in a number of transition metal and p-block complexes. The database and ab initio studies showed that the classical trans influence model based on Pt(II) chemistry does not always hold. For some systems (eg. d sup 1 sup 0 s sup 0 for Sb sup V and Sn sup I sup V) the cis influence is of similar magnitude to the trans influence. For other systems (d sup 0), the trans influence is not as powerful as usually assumed. Chapter 3 is an investigation into the bridging chloride unit. A database study was performed on three systems (M-CI-M', M-CI...H and M-CI...Li/Na/K). Reaction pathway analysis was carried out for the M-CI-M' case and showed that bond order is not con...

  19. Structural and Topology Optimization of Complex Civil Engineering Structures

    DEFF Research Database (Denmark)

    Hald, Frederik; Kirkegaard, Poul Henning; Andersen, Lars Vabbersgaard

    2013-01-01

    will be optimized using the commercial code Abaqus CAE. The structures are: a bucket foundation for an off-shore submarine structure for a wind turbine, and a pedestrian footbridge over a freeway. The topology optimization method used is the SIMP method, based on minimizing the structures' compliance. Complex load...

  20. Structural variations in pig genomes

    NARCIS (Netherlands)

    Paudel, Y.

    2015-01-01

    Abstract Paudel, Y. (2015). Structural variations in pig genomes. PhD thesis, Wageningen University, the Netherlands Structural variations are chromosomal rearrangements such as insertions-deletions (INDELs), duplications, inversions, translocations, and copy number variations (CNVs

  1. Vibration suppression using smart structures

    Science.gov (United States)

    Garcia, Ephrahim; Inman, Daniel J.; Dosch, Jeffrey

    1991-01-01

    The control of structures for vibration suppression is discussed in the context of using smart materials and structures. Here the use of smart structures refers to using embedded piezoelectric devices as both control actuators and sensors. Using embedded sensors and actuators allows great improvements in performance over traditional structures (both passive and active) for vibration suppression. The application of smart structures to three experimental flexible structures is presented. The first is a flexible beam, the second is a flexible beam undergoing slewing motion, the third is a ribbed antenna. A simple model of a piezoelectric actuator/sensor is presented. The equations of motion for each structure is presented. The control issues considered as those associated with multi-input, multi-output control, PID control and LQR control implementation. A modern control analysis illustrates the usefulness of smart structures for vibration suppression.

  2. Lifting locally homogeneous geometric structures

    CERN Document Server

    McKay, Benjamin

    2011-01-01

    We prove that under some purely algebraic conditions every locally homogeneous structure modelled on some homogeneous space is induced by a locally homogeneous structure modelled on a different homogeneous space.

  3. 40_ _230 - 233__Hassan _Structural

    African Journals Online (AJOL)

    User

    Bayero Journal of Pure and Applied Sciences, 9(2): 230 - 233. Received: ... electron microscopy (SEM) were used to observe the surface and internal structure of the quartz. The results ... structure of a material may be divided into four levels:.

  4. Dictionary of forest structural terminology

    CSIR Research Space (South Africa)

    Geldenhuys, CJ

    1988-01-01

    Full Text Available This report lists and defines attributes (both functional and structural) that have been used in other structural classifications of forest vegetation. Field techniques are summarized. The recommended use of each attribute and technique is presented...

  5. GPCR structures in drug design, emerging opportunities with new structures.

    Science.gov (United States)

    Tautermann, Christofer S

    2014-09-01

    In recent years, GPCR targets from diverse regions of phylogenetic space have been determined. This effort has culminated this year in the determination of representatives of all major classes of GPCRs (A, B, C, and F). Although much of the now well established knowledge on GPCR structures has been known for some years, the new high-resolution structures allow structural insight into the causes of ligand efficacy, biased signaling, and allosteric modulation. In this digest the structural basis for GPCR signaling in the light of the new structures is reviewed and the use of the new non-class A GPCRs for drug design is discussed.

  6. Structural Assembly Demonstration Experiment (SADE)

    Science.gov (United States)

    Akin, David L.; Mills, Raymond A.; Bowden, Mary L.

    1987-01-01

    The purpose of the Structural Assembly Demonstration Experiment (SADE) was to create a near-term Shuttle flight experiment focusing on the deployment and erection of structural truss elements. The activities of the MIT Space Systems Laboratory consist of three major areas: preparing and conducting neutral buoyancy simulation test series; producing a formal SADE Experiment plan; and studying the structural dynamics issues of the truss structure. Each of these areas is summarized.

  7. Porous Structure of Road Concrete

    OpenAIRE

    2016-01-01

    Having a great number of concrete structure classifications it is recommended to specify the following three principal types: microstructure – cement stone structure; mesostructure – structure of cement-sand mortar in concrete; macrostucture – two-component system that consists of mortar and coarse aggregate. Every mentioned-above structure has its own specific features which are related to the conditions of their formation. Thus, microstructure of cement stone can be characterized by such st...

  8. Structure Prediction of Membrane Proteins

    Institute of Scientific and Technical Information of China (English)

    Chunlong Zhou; Yao Zheng; Yan Zhou

    2004-01-01

    There is a large gap between the number of membrane protein (MP) sequences and that of their decoded 3D structures, especially high-resolution structures, due to difficulties in crystal preparation of MPs. However, detailed knowledge of the 3D structure is required for the fundamental understanding of the function of an MP and the interactions between the protein and its inhibitors or activators. In this paper, some computational approaches that have been used to predict MP structures are discussed and compared.

  9. Harmonic structures and intrinsic torsion

    DEFF Research Database (Denmark)

    Conti, Diego; Madsen, Thomas Bruun

    We discuss the construction of 8-manifolds with harmonic Sp(2)Sp(1)-structures. In particular, we find 10 new examples of nilmanifolds that admit a closed 4-form Omega whose stabiliser is Sp(2)Sp(1). Our constructions entail the notion of SO(4)-structures on 7-manifolds. We present a thorough inv...... investigation of the intrinsic torsion of such structures; in addition to the construction of harmonic structures, this analysis leads to explicit Lie group examples with invariant intrinsic torsion....

  10. Synchronously deployable truss structure

    Science.gov (United States)

    Bush, H. G. (Inventor); Mikulas, M., Jr. (Inventor); Wallsom, E. (Inventor)

    1986-01-01

    A collapsible-expandable truss structure, including first and second spaced surface truss layers having an attached core layer is described. The surface truss layers are composed of a plurality of linear struts arranged in multiple triangular configurations. Each linear strut is hinged at the center and hinge connected at each end to a nodular joint. A passive spring serves as the expansion force to move the folded struts from a stowed collapsed position to a deployed operative final truss configuration. A damper controls the rate of spring expansion for the synchronized deployment of the truss as the folded configuration is released for deployment by the restrain belts. The truss is synchronously extended under the control of motor driven spools.

  11. Functional structure of stomodeum

    Directory of Open Access Journals (Sweden)

    Chependyuk Т.А.

    2014-06-01

    Full Text Available Purpose: identification of the structure providing outflow of liquid from stomodeum in the process of formation. Material and Methods. 150 stomodea have been investigated for the ways of removal of liquid by the following methods: stage-by-stage freezing, contrasting and macerations. Result. One of the ways of removal of liquid from enamel of a being formed tooth is the crypt canal. Conclusion. Function of the channel of a crypt of developing teeth consists of removal of biological specific dental fluid from a surface of enamel of stomodeum in a mouth in the following options: on an oral surface of alveolar processes, near a periodontal fissure, or directly in a periodontium of a milk tooth — predecessor.

  12. Structure of Chinese algebras

    CERN Document Server

    Jaszunska, Joanna

    2010-01-01

    The structure of the algebra K[M] of the Chinese monoid M over a field K is studied. The minimal prime ideals are described. They are determined by certain homogeneous congruences on M and they are in a one to one correspondence with diagrams of certain special type. There are finitely many such ideals. It is also shown that the prime radical B(K[M]) of K[M] coincides with the Jacobson radical and the monoid M embeds into the algebra K[M]/B(K[M]). A new representation of M as a submonoid of the direct product of finitely many copies of the bicyclic monoid and finitely many copies of the infinite cyclic monoid is derived. Consequently, M satisfies a nontrivial identity.

  13. Introduction to stellar structure

    CERN Document Server

    Maciel, Walter J

    2016-01-01

    In the first part of this book, the author presents the basic properties of the stellar interior and describes them thoroughly, along with deriving the main stellar structure equations of temperature, density, pressure and luminosity, among others. The process and application of solving these equations is explained, as well as linking these results with actual observations.  The second part of the text describes what happens to a star over time, and how to determine this by solving the same equations at different points during a star’s lifetime. The fate of various stars is quite different depending on their masses, and this is described in the final parts of the book. This text can be used for an upper level undergraduate course or an introductory graduate course on stellar physics.

  14. Crystal structure of ruthenocenecarbonitrile

    Directory of Open Access Journals (Sweden)

    Frank Strehler

    2015-04-01

    Full Text Available The molecular structure of ruthenocenecarbonitrile, [Ru(η5-C5H4C[triple-bond]N(η5-C5H5], exhibits point group symmetry m, with the mirror plane bisecting the molecule through the C[triple-bond]N substituent. The RuII atom is slightly shifted from the η5-C5H4 centroid towards the C[triple-bond]N substituent. In the crystal, molecules are arranged in columns parallel to [100]. One-dimensional intermolecular π–π interactions [3.363 (3 Å] between the C[triple-bond]N carbon atom and one carbon of the cyclopentadienyl ring of the overlaying molecule are present.

  15. Structure-mediated nanoscopy

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas

    2013-01-01

    -robotics requires the optimization of optical forces and torques that, in turn, requires optimization of the underlying light-matter interaction. The requirement of having tightly focused beams in optical tweezing systems exemplifies the need for optimal light-shaping in optical trapping, manipulation and sorting...... of optimal light-sculpting techniques [4] with the use of optimized shapes in micro-robotics structures [5]. Micro-fabrication processes such as two-photon photo-polymerization offer three-dimensional resolutions for creating custom-designed monolithic microstructures that can be equipped with optical...... trapping handles for convenient mechanical control using only optical forces [6]. These microstructures can be effectively handled with simultaneous top- and side-view on our BioPhotonics Workstation to carry out proof-of-principle experiments illustrating the six-degree-of-freedom optical actuation of two...

  16. Structural color in Myxomycetes.

    Science.gov (United States)

    Inchaussandague, Marina; Skigin, Diana; Carmaran, Cecilia; Rosenfeldt, Sonia

    2010-07-19

    In this paper we report evidence of structural color in Myxomycetes, a group of eukaryotic microorganisms with an uncertain taxonomic position. We investigated the Diachea leucopoda, which belongs to the Physarales order, Myxomycetes class, and found that its peridium -protective layer that encloses the mass of spores- is basically a corrugated layer of a transparent material, which produces a multicolored pointillistic effect, characteristic of this species. Scanning (SEM) and transmission (TEM) electron microscopy techniques have been employed to characterize the samples. A simple optical model of a planar slab is proposed to calculate the reflectance. The chromaticity coordinates are obtained, and the results confirm that the color observed is a result of an interference effect.

  17. Crystal structure of propaquizafop

    Directory of Open Access Journals (Sweden)

    Youngeun Jeon

    2014-12-01

    Full Text Available The title compound, C22H22ClN3O5 {systematic name: 2-(propan-2-ylideneaminooxyethyl (R-2-[4-(6-chloroquinoxalin-2-yloxyphenoxy]propionate}, is a herbicide. The asymmetric unit comprises two independent molecules in which the dihedral angles between the phenyl ring and the quinoxaline ring plane are 75.93 (7 and 82.77 (8°. The crystal structure features C—H...O, C—H...N, and C—H...Cl hydrogen bonds, as well as weak π–π interactions [ring-centroid separation = 3.782 (2 and 3.5952 (19 Å], resulting in a three-dimensional architecture.

  18. Thai Rhetorical Structure Analysis

    CERN Document Server

    Sinthupoun, Somnuk

    2010-01-01

    A rhetorical structure tree (RS tree) is a representation of discourse relations among elementary discourse units (EDUs). A RS tree is very useful to many text processing tasks employing relationships among EDUs such as text understanding, summarization, and question answering. Thai language with its unique linguistic characteristics requires a unique RS tree construction technique. This paper proposes an approach for Thai RS tree construction which consists of three major steps: EDU segmentation, Thai RS tree construction, and discourse relation (DR) identification. Two hidden markov models derived from grammatical rules are used to segment EDUs, a clustering technique with its similarity measure derived from Thai semantic rules is used to construct a Thai RS tree, and a decision tree whose features extracted from the rules is used to determine the DR between EDUs. The proposed technique is evaluated using three Thai corpora. The results show the Thai RS tree construction and the DR identification effectiven...

  19. Microfibrillar Structure of Silks

    Science.gov (United States)

    Putthanarat, Sirina; Eby, Ronald K.; Adams, W. W.; Liu, G. F.

    1998-03-01

    We have previously observed the dragline silk of Nephila clavipes and the silk of Bombyx mori exhibit a range of morphological feature including microfibers (S. Putthanarat; R.K. Eby; W.W. Adams; G.F. Liu J.M.S.-Pure Appl. Chem. 1996, A33(7), 899) and a layered structure. In successive layers the microfibers appeared to be oriented at different small angles to the fiber axis. Further work with the Atomic Force Microscope (AFM) on the silk of B. mori has confirmed these observations and shown other features. One of the latter is a series of raised "steps" spaced somewhat regularly along the fiber. Investigation of peeled three-molted B. mori and Antheraea yamamai (Japanese Tussah) and other silks has shown features very similar to all those in the silk of B. mori. AFM images, characterization, and analyses will be shown for all the silks and their features

  20. Everett and Structure

    CERN Document Server

    Wallace, D

    2001-01-01

    I address the problem of indefiniteness in quantum mechanics: the problem that the theory, without changes to its formalism, seems to predict that macroscopic quantities have no definite values. The Everett interpretation is often criticised along these lines and I shall argue that much of this criticism rests on a false dichotomy: that the macroworld must either be written directly into the formalism or be regarded as somehow illusory. By means of analogy with other areas of physics, I develop the view that the macroworld is instead to be understood in terms of certain structures and patterns which emerge from quantum theory (given appropriate dynamics, in particular decoherence). I extend this view to the observer, and in doing so make contact with functionalist theories of mind.

  1. Cosmological Structure Formation

    CERN Document Server

    Primack, Joel R

    2015-01-01

    LCDM is remarkably successful in predicting the cosmic microwave background and large-scale structure, and LCDM parameters have been determined with only mild tensions between different types of observations. Hydrodynamical simulations starting from cosmological initial conditions are increasingly able to capture the complex interactions between dark matter and baryonic matter in galaxy formation. Simulations with relatively low resolution now succeed in describing the overall galaxy population. For example, the EAGLE simulation in volumes up to 100 cubic Mpc reproduces the observed local galaxy mass function nearly as well as semi-analytic models. It once seemed that galaxies are pretty smooth, that they generally grow in size as they evolve, and that they are a combination of disks and spheroids. But recent HST observations combined with high-resolution hydrodynamic simulations are showing that most star-forming galaxies are very clumpy; that galaxies often undergo compaction which reduces their radius and ...

  2. Ethnic family structure.

    Science.gov (United States)

    Mcdonald, P

    1989-04-01

    Using information from large-scale statistical collections and elaborations from ethnographic studies, this paper examines the underlying social processes and structures of migrant families in Australia. Migrants in Australia are often confronted by family values and behavior which run counter to their own. For some migrants, particularly those from the United Kingdom and Western European countries, there is little conflict as Australian family values and behavior approximate their own; the feminine conception of the family is not foreign to them. On the other hand, migrants from Mediterranean countries and from Asia are likely to face a clash between the masculine conception of the family and the dominant feminine conception they find in Australia. Economic structure also often forces an accommodation to the feminine conception of the family. For example, migrant women in Australia are heavily involved in the work force outside the family circle, and, in the main, have relatively low fertility. Age at marriage is increasing and many single women of migrant origin are being educated at the tertiary level and are working before marriage. These changes necessarily expose women and youths to the dominant social values and increase their economic independence, thus disrupting the conventional male family authority. There is evidence of a degree of accommodation to Australian patterns of behavior in migrant groups more inclined to a masculine conception of the family. In other areas, however, which are less directly related to economic pressure, migrant values have been far less accommodating. There is still a high level of endogamy, the 1st birth occurs soon after marriage, divorce rates are low, and the aged are very likely to live with their children. Large migrant groups have been able to maintain these patterns of behavior through the formation of ethnic substructures that form their principal social environment. In the longer term, however, their children are

  3. Crystallographic structure solution

    Directory of Open Access Journals (Sweden)

    Millán, Claudia

    2015-04-01

    Full Text Available The three-dimensional view of molecules at the atomic level provided by X-ray crystallography is not only extremely informative but is also easily and intuitively understood by humans, who very much rely on their vision. However, unlike microscopy, this technique does not directly yield an image. The structural model cannot be directly calculated from the diffraction data, as only the intensities of scattered beams and not their phases are experimentally accessible. In order to obtain the 3-dimensional structure phases have to be obtained by either additional experimental or computational methods. This is known as the phase problem in crystallography. In this manuscript we provide an overview of major milestones along the quest for the lost phases.La cristalografía proporciona una visión tridimensional de las moléculas a un nivel de detalle atómico, que no sólo resulta muy informativa sino que además puede ser fácil e intuitivamente comprendida por seres tan predominantemente visuales como solemos ser los humanos. Sin embargo, al contrario que la microscopía, esta técnica no ofrece directamente una imagen y el modelo estructural no puede calcularse directamente a partir de los datos de difracción, ya que solamente las intensidades de los rayos difractados y no sus fases son accesibles a la medida experimental. Para determinar la estructura tridimensional las fases deben ser obtenidas por medio de métodos adicionales, bien experimentales o computacionales. Esto constituye el problema de la fase en cristalografía. En este artículo ofreceremos una visión general de los principales hitos en la búsqueda de las fases perdidas.

  4. Structural alignment of RNA with triple helix structure.

    Science.gov (United States)

    Wong, Thomas K F; Yiu, S M

    2012-04-01

    Structural alignment is useful in identifying members of ncRNAs. Existing tools are all based on the secondary structures of the molecules. There is evidence showing that tertiary interactions (the interaction between a single-stranded nucleotide and a base-pair) in triple helix structures are critical in some functions of ncRNAs. In this article, we address the problem of structural alignment of RNAs with the triple helix. We provide a formal definition to capture a simplified model of a triple helix structure, then develop an algorithm of O(mn(3)) time to align a query sequence (of length m) with known triple helix structure with a target sequence (of length n) with an unknown structure. The resulting algorithm is shown to be useful in identifying ncRNA members in a simulated genome.

  5. Enumerating secondary structures and structural moieties for circular RNAs

    CERN Document Server

    Cuesta, José A

    2016-01-01

    A quantitative characterization of the relationship between molecular sequence and structure is essential to improve our understanding of how function emerges. This particular genotype-phenotype map has been often studied in the context of RNA sequences, with the folded configurations standing as a proxy for the phenotype. Here, we count the secondary structures of circular RNAs of length $n$ and calculate the asymptotic distributions of different structural moieties, such as stems or hairpin loops, by means of symbolic combinatorics. Circular RNAs differ in essential ways from their linear counterparts. From the mathematical viewpoint, the enumeration of the corresponding secondary structures demands the use of combinatorial techniques additional to those used for linear RNAs. The asymptotic number of secondary structures for circular RNAs grows as $a^nn^{-5/2}$, with a depending on particular constraints applied to the secondary structure. The abundance of any structural moiety is normally distributed in th...

  6. CLIC Drive Beam Accelerating Structures

    CERN Document Server

    Wegner, Rolf

    2012-01-01

    Travelling structures for accelerating the high-current (4.2 A) CLIC Drive Beam to an energy of 2.37 GeV are presented. The structures are optimised for efficiency (full beam loading operation) and a desired filling time. Higher order modes are studied and are reduced by detuning along the structure and by damping with silicon carbide loads.

  7. Empirical Evidence for Narrative Structure.

    Science.gov (United States)

    Gee, James Paul; Grosjean, Francois

    1984-01-01

    Used experimental tasks--spontaneous telling of a story, reading, and parsing--to determine whether empirical data reflect narrative structure of stories. It was concluded that spontaneous pausing reflects the narrative structure and can be used as a guide to constructing theories of narrative structure and deciding between competing theories.…

  8. Structural rehabilitation of old buildings

    CERN Document Server

    Guedes, João; Varum, Humberto

    2014-01-01

    The present book describes the different construction systems and structural materials and solutions within the main old buildings typologies, and it analyses the particularities of each of them, including mechanical properties, structural behaviour, typical damage patterns and collapse mechanisms. Common or pioneering intervention measures to repair and/or strengthen some of these structural elements are also reviewed.

  9. Update on protein structure prediction

    DEFF Research Database (Denmark)

    Hubbard, T; Tramontano, A; Barton, G

    1996-01-01

    Computational tools for protein structure prediction are of great interest to molecular, structural and theoretical biologists due to a rapidly increasing number of protein sequences with no known structure. In October 1995, a workshop was held at IRBM to predict as much as possible about a numbe...

  10. CSM parallel structural methods research

    Science.gov (United States)

    Storaasli, Olaf O.

    1989-01-01

    Parallel structural methods, research team activities, advanced architecture computers for parallel computational structural mechanics (CSM) research, the FLEX/32 multicomputer, a parallel structural analyses testbed, blade-stiffened aluminum panel with a circular cutout and the dynamic characteristics of a 60 meter, 54-bay, 3-longeron deployable truss beam are among the topics discussed.

  11. Photothermal modification of plasmonic structures

    DEFF Research Database (Denmark)

    2016-01-01

    There is presented a method for geometrically modifying plasmonic structures on a support structure, such as for printing or recording, said method comprising changing a geometry specifically of plasmonic structures, wherein said changing the geometry is carried out by photothermally melting...

  12. Exploring Coronal Structures with SOHO

    Indian Academy of Sciences (India)

    Μ. Karovska; Β. Wood; J. Chen; J. Cook; R. Howard

    2000-09-01

    We applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

  13. Two Decades of Structure Building.

    Science.gov (United States)

    Gernsbacher, Morton Ann

    1997-01-01

    Offers a brief overview of the Structure Building Framework, a simple framework for describing the cognitive processes and mechanisms involved in discourse comprehension. Reviews the seminal work on which it is based (the first decade of structure-building research); and recounts the research conducted by the author to test the Structure Building…

  14. Structural image and video understanding

    NARCIS (Netherlands)

    Lou, Z.

    2016-01-01

    In this thesis, we have discussed how to exploit the structures in several computer vision topics. The five chapters addressed five computer vision topics using the image structures. In chapter 2, we proposed a structural model to jointly predict the age, expression and gender of a face. By modeling

  15. The science of food structuring

    NARCIS (Netherlands)

    Sman, van der R.G.M.; Goot, van der A.J.

    2009-01-01

    Food structuring is discussed from the viewpoints of soft matter physics and molecular gastronomy. Food is one of the most complex types of soft matter, with multiple dispersed phases and even hierarchical structure. Food structuring seems to be a kind of art, comprising a careful balance between fo

  16. Perspectival Structure and Vestibular Processing

    DEFF Research Database (Denmark)

    Alsmith, Adrian John Tetteh

    2015-01-01

    I begin by contrasting a taxonomic approach to the vestibular system with the structural approach I take in the bulk of this commentary. I provide an analysis of perspectival structure. Employing that analysis and following the structural approach, I propose three lines of empirical investigation...

  17. Perspectival Structure and Vestibular Processing

    DEFF Research Database (Denmark)

    Alsmith, Adrian John Tetteh

    2016-01-01

    I begin by contrasting a taxonomic approach to the vestibular system with the structural approach I take in the bulk of this commentary. I provide an analysis of perspectival structure. Employing that analysis and following the structural approach, I propose three lines of empirical investigation...

  18. The science of food structuring

    NARCIS (Netherlands)

    Sman, van der R.G.M.; Goot, van der A.J.

    2009-01-01

    Food structuring is discussed from the viewpoints of soft matter physics and molecular gastronomy. Food is one of the most complex types of soft matter, with multiple dispersed phases and even hierarchical structure. Food structuring seems to be a kind of art, comprising a careful balance between

  19. Strength of Materials and Structures

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ All engineering structures designed according to modern principles have to be strong and sufficiently rigid. Scientists and engineers have long recognized the importance of the strength of materials and structures, and dedicated much their efforts to both fundamental and industrial research into the theory for vast engineering materials and various structures. A lot of engineers need to be familiar with the fundamental principles of strength in materials and structures in order to design structures to resist failures. This book is a very good one to provide them with these principles.

  20. A molecular-structure hypothesis.

    Science.gov (United States)

    Boeyens, Jan C A

    2010-11-01

    The self-similar symmetry that occurs between atomic nuclei, biological growth structures, the solar system, globular clusters and spiral galaxies suggests that a similar pattern should characterize atomic and molecular structures. This possibility is explored in terms of the current molecular structure-hypothesis and its extension into four-dimensional space-time. It is concluded that a quantum molecule only has structure in four dimensions and that classical (Newtonian) structure, which occurs in three dimensions, cannot be simulated by quantum-chemical computation.

  1. Structural dynamic modifications via models

    Indian Academy of Sciences (India)

    T K Kundra

    2000-06-01

    Structural dynamic modification techniques attempt to reduce dynamic design time and can be implemented beginning with spatial models of structures, dynamic test data or updated models. The models assumed in this discussion are mathematical models, namely mass, stiffness, and damping matrices of the equations of motion of a structure. These models are identified/extracted from dynamic test data viz. frequency response functions (FRFs). Alternatively these models could have been obtained by adjusting or updating the finite element model of the structure in the light of the test data. The methods of structural modification for getting desired dynamic characteristics by using modifiers namely mass, beams and tuned absorbers are discussed.

  2. A Molecular–Structure Hypothesis

    Directory of Open Access Journals (Sweden)

    Jan C. A. Boeyens

    2010-11-01

    Full Text Available The self-similar symmetry that occurs between atomic nuclei, biological growth structures, the solar system, globular clusters and spiral galaxies suggests that a similar pattern should characterize atomic and molecular structures. This possibility is explored in terms of the current molecular structure-hypothesis and its extension into four-dimensional space-time. It is concluded that a quantum molecule only has structure in four dimensions and that classical (Newtonian structure, which occurs in three dimensions, cannot be simulated by quantum-chemical computation.

  3. Foam rigidized inflatable structural assemblies

    Science.gov (United States)

    Tinker, Michael L. (Inventor); Schnell, Andrew R. (Inventor)

    2010-01-01

    An inflatable and rigidizable structure for use as a habitat or a load bearing structure is disclosed. The structure consists of an outer wall and an inner wall defining a containment member and a bladder. The bladder is pressurized to erect the structure from an initially collapsed state. The containment member is subsequently injected with rigidizable fluid through an arrangement of injection ports. Exhaust gases from the curing rigidizable fluid are vented through an arrangement of exhaust ports. The rate of erection can be controlled by frictional engagement with a container or by using a tether. A method for fabricating a tubular structure is disclosed.

  4. Robustness Evaluation of Timber Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

    2009-01-01

    The present paper considers robustness evaluation of a Norwegian sports arena with a structural system of glulam frames. The robustness evaluation is based on the framework for robustness analysis introduced in the Danish Code of Practice for the Safety of Structures and a probabilistic modelling...... of the timber material proposed in the Probabilistic Model Code (PMC) of the Joint Committee on Structural Safety (JCSS). The results show that the requirements for robustness of the structure are highly related to the modelling of the snow load used on the structures when ‘removal of a limited part...

  5. Structural determination of argon trimer

    Directory of Open Access Journals (Sweden)

    Xiguo Xie

    2015-09-01

    Full Text Available Rare gas clusters are model systems to investigate structural properties at finite size. However, their structures are difficult to be determined with available experimental techniques because of the strong coupling between the vibration and the rotation. Here we experimentally investigated multiple ionization and fragmentation dynamics of argon trimer by ultrashort intense laser fields and reconstructed their structures with Coulomb explosion technique. The measured structure distribution was compared with our finite-temperature ab initio calculations and the discrepancy was discussed. The present study provides a guidance for the development of theoretical methods for exploring the geometric structure of rare gas clusters.

  6. Structure validation in chemical crystallography.

    Science.gov (United States)

    Spek, Anthony L

    2009-02-01

    Automated structure validation was introduced in chemical crystallography about 12 years ago as a tool to assist practitioners with the exponential growth in crystal structure analyses. Validation has since evolved into an easy-to-use checkCIF/PLATON web-based IUCr service. The result of a crystal structure determination has to be supplied as a CIF-formatted computer-readable file. The checking software tests the data in the CIF for completeness, quality and consistency. In addition, the reported structure is checked for incomplete analysis, errors in the analysis and relevant issues to be verified. A validation report is generated in the form of a list of ALERTS on the issues to be corrected, checked or commented on. Structure validation has largely eliminated obvious problems with structure reports published in IUCr journals, such as refinement in a space group of too low symmetry. This paper reports on the current status of structure validation and possible future extensions.

  7. Combinatorics of γ-structures.

    Science.gov (United States)

    Han, Hillary S W; Li, Thomas J X; Reidys, Christian M

    2014-08-01

    In this article we study canonical γ-structures, a class of RNA pseudoknot structures that plays a key role in the context of polynomial time folding of RNA pseudoknot structures. A γ-structure is composed of specific building blocks that have topological genus less than or equal to γ, where composition means concatenation and nesting of such blocks. Our main result is the derivation of the generating function of γ-structures via symbolic enumeration using so called irreducible shadows. We furthermore recursively compute the generating polynomials of irreducible shadows of genus ≤ γ. The γ-structures are constructed via γ-matchings. For 1 ≤ γ ≤ 10, we compute Puiseux expansions at the unique, dominant singularities, allowing us to derive simple asymptotic formulas for the number of γ-structures.

  8. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  9. Building large structures in space

    Science.gov (United States)

    Hagler, T.

    1976-01-01

    The building of large structures in space would be required for the establishment of a variety of systems needed for different forms of space utilization. The problems involved in the building of such structures in space and the approaches which can be used to solve these problems are illustrated with the aid of an example involving a concept for packaging, transporting, and assembling two representative large space structures. The structure of a radio-astronomy telescope 200 m in diam was felt to be representative of the many medium-size structures of the Shuttle era. A typical very large structure is represented by the supporting structure for the transmission system of a 5000-Mw space solar power station.

  10. Structural Genomics of Protein Phosphatases

    Energy Technology Data Exchange (ETDEWEB)

    Almo,S.; Bonanno, J.; Sauder, J.; Emtage, S.; Dilorenzo, T.; Malashkevich, V.; Wasserman, S.; Swaminathan, S.; Eswaramoorthy, S.; et al

    2007-01-01

    The New York SGX Research Center for Structural Genomics (NYSGXRC) of the NIGMS Protein Structure Initiative (PSI) has applied its high-throughput X-ray crystallographic structure determination platform to systematic studies of all human protein phosphatases and protein phosphatases from biomedically-relevant pathogens. To date, the NYSGXRC has determined structures of 21 distinct protein phosphatases: 14 from human, 2 from mouse, 2 from the pathogen Toxoplasma gondii, 1 from Trypanosoma brucei, the parasite responsible for African sleeping sickness, and 2 from the principal mosquito vector of malaria in Africa, Anopheles gambiae. These structures provide insights into both normal and pathophysiologic processes, including transcriptional regulation, regulation of major signaling pathways, neural development, and type 1 diabetes. In conjunction with the contributions of other international structural genomics consortia, these efforts promise to provide an unprecedented database and materials repository for structure-guided experimental and computational discovery of inhibitors for all classes of protein phosphatases.

  11. The structure of physics

    CERN Document Server

    Von Weizsäcker, Carl Friedrich; Lyre, Holger

    2006-01-01

    Carl Friedrich von Weizsäcker‘s "Aufbau der Physik", first published in 1985, was intended as an overview of his lifelong concern: an understanding of the unity of physics. That is, the idea of a quantum theory of binary alternatives (the so-called ur-theory), a unified quantum theoretical framework in which spinorial symmetry groups are considered to give rise to the structure of space and time. The book saw numerous reprints, but it was published in German only. The present edition, in English, provides a newly arranged and revised version, in which some original chapters and sections have been deleted, and a new chapter about further insights and results of ur-theoretic research of the late 1980’s and 1990’s, mainly by the work of Thomas Görnitz, has been included, as well as a general introduction to Weizsäcker’s Philosophy of Physics. Carl Friedrich von Weizsäcker also enjoys high esteem by a much broader audience for his socio-cultural, political and religious thoughts and writings. In him t...

  12. Electronic structure of PCBM

    Institute of Scientific and Technical Information of China (English)

    Sheng Chun-Qi; Wang Peng; Shen Ying; Li Yan-Jun; Zhang Wen-Hua; Xu Fa-Qiang; Zhu Jun-Fa; Li Hong-Nian; Lai Guo-Qiao

    2012-01-01

    We have studied the electronic structure of [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) using synchrotron radiation photoelectron spectroscopy (PES) measurements and first-principles calculations.The PES spectrum of the entire occupied valence band is reported,which exhibits abundant spectral features from the Fermi level to ~ 24 eV binding energy. All the spectral features are broadened as compared with the cases of C60. The reasons for the broadening are analysed by comparing the experimental data with the calculated energy levels and density of states.Special attention is paid to the analysis of the C60 highest occupied molecular orbital (HOMO)-1 derived states,which can play a crucial role in the bonding at the interfaces of PCBM/polymer blenders or PCBM/electrodes.Besides the well-known energy level splitting of the C60 backbone caused by the lowered symmetry,C 2p states from the side chain mix or hybridize with the molecular orbitals of parent C60.The contribution of the O 2p states can substantially modify the PES spectrum.

  13. Risk, Resources and Structures

    DEFF Research Database (Denmark)

    Lyng Jensen, Jesper; Ponsaing, Claus Due; Thrane, Sof

    2012-01-01

    In this article, we describe a basic mechanism by which risk events can induce indirect value losses to the risk owner: a value loss arising from a risk event interfering with activities that have no logical connection with the risk event other than that of having the same owner; a mechanism we h...... and implications for ERM, suggesting the addition of a risk resource forecast and discussing implications for four types of risk mitigation strategies: capital requirements, risk diversification, network relations and insurance.......In this article, we describe a basic mechanism by which risk events can induce indirect value losses to the risk owner: a value loss arising from a risk event interfering with activities that have no logical connection with the risk event other than that of having the same owner; a mechanism we...... have named Structural Risk. This effect is caused by the occurrence of a resource fluctuation which challenges the risk owner's ability to gain control of adequate resources, thus forcing the risk owner to prioritize and terminate other activities and projects. In this process value is destroyed...

  14. Scaling of structural failure

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-01-01

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

  15. Stellar Structure and Evolution

    CERN Document Server

    Kippenhahn, Rudolf; Weiss, Achim

    2013-01-01

    This long-awaited second edition of the classical textbook on Stellar Structure and Evolution by Kippenhahn and Weigert is a thoroughly revised version of the original text. Taking into account modern observational constraints as well as additional physical effects such as mass loss and diffusion, Achim Weiss and Rudolf Kippenhahn have succeeded in bringing the book up to the state-of-the-art with respect to both the presentation of stellar physics and the presentation and interpretation of current sophisticated stellar models. The well-received and proven pedagogical approach of the first edition has been retained. The book provides a comprehensive treatment of the physics of the stellar interior and the underlying fundamental processes and parameters. The models developed to explain the stability, dynamics and evolution of the stars are presented and great care is taken to detail the various stages in a star’s life. Just as the first edition, which remained a standard work for more than 20 years after its...

  16. Galactic Spiral Structure

    CERN Document Server

    Francis, Charles

    2009-01-01

    We describe the structure and composition of six major stellar streams in a population of 20 574 local stars in the New Hipparcos Reduction with known radial velocities. We find that, once fast moving stars are excluded, almost all stars belong to one of these streams. The results of our investigation have lead us to re-examine the hydrogen maps of the Milky Way, from which we identify the possibility of a symmetric two-armed spiral with half the conventionally accepted pitch angle. We describe a model of spiral arm motions which matches the observed velocities and composition of the six major streams, as well as the observed velocities of the Hyades and Praesepe clusters at the extreme of the Hyades stream. Stellar orbits are perturbed ellipses aligned at a focus in coordinates rotating at the rate of precession of pericentre. Stars join a spiral arm just before apocentre, follow the arm for more than half an orbit, and leave the arm soon after pericentre. Spiral pattern speed equals the mean rate of precess...

  17. Crystal structure of oxamyl

    Directory of Open Access Journals (Sweden)

    Eunjin Kwon

    2016-12-01

    Full Text Available The title compound, C7H13N3O3S [systematic name: (Z-methyl 2-dimethylamino-N-(methylcarbamoyloxy-2-oxoethanimidothioate], is an oxime carbamate acaride, insecticide and nematicide. The asymmetric unit comprises two independent molecules, A and B. The dihedral angles between the mean planes [r.m.s. deviations = 0.0017 (A and 0.0016 Å (B] of the acetamide and oxyimino groups are 88.80 (8° for A and 87.05 (8° for B. In the crystal, N/C—H...O hydrogen bonds link adjacent molecules, forming chains along the a axis. The chains are further linked by C—H...O hydrogen bonds, resulting in a three-dimensional network with alternating rows of A and B molecules in the bc plane stacked along the a-axis direction. The structure was refined as an inversion twin with a final BASF parameter of 0.16 (9.

  18. Direct atomic structure determination by the inspection of structural phase.

    Science.gov (United States)

    Nakashima, Philip N H; Moodie, Alexander F; Etheridge, Joanne

    2013-08-27

    A century has passed since Bragg solved the first atomic structure using diffraction. As with this first structure, all atomic structures to date have been deduced from the measurement of many diffracted intensities using iterative and statistical methods. We show that centrosymmetric atomic structures can be determined without the need to measure or even record a diffracted intensity. Instead, atomic structures can be determined directly and quickly from the observation of crystallographic phases in electron diffraction patterns. Furthermore, only a few phases are required to achieve high resolution. This represents a paradigm shift in structure determination methods, which we demonstrate with the moderately complex α-Al2O3. We show that the observation of just nine phases enables the location of all atoms with a resolution of better than 0.1 Å. This level of certainty previously required the measurement of thousands of diffracted intensities.

  19. Flower structures in the Ales coal basin - structural implications

    Energy Technology Data Exchange (ETDEWEB)

    Genna, A.; Debriette, P.J. (Bureau de Recherches Geologiques et Minieres, Orleans (France). Dept. de Geologie)

    1994-04-07

    The presence of flower structures in the Stephanian Ales (coal) basin has led the authors propose a new formation model for the basin, based on reverse strike-slip movement along N-S to NW-SE striking basement faults. This model confirms, through structural arguments, the recent questioning of the traditional explanation of the basin structure as thrust sheets. Such compressive strike-slip structures are not taken into account by the model of late Hercynian crustal extension in the French Massif Central.

  20. Motion Structural Optimization Strategy for Rhombic Element Based Foldable Structure

    Directory of Open Access Journals (Sweden)

    Seung Hyun Jeong

    2015-02-01

    Full Text Available This research presents a new systematical design approach of foldable structure composed of several rhombic elements by applying genetic algorithm. As structural shapes represented by a foldable structure can be easily and dramatically morphed by manipulating rotational directions and angle of joints, the foldable structure has been used for various elementary structural members and engineering mechanisms. However a systematic design approach determining detail rotational angle and directions of unit cells for arbitrary shaped target areas has not been proposed yet. This research contributes to it by developing a new structural optimization method determining optimal angle and rotation directions to cover arbitrary shaped target areas of interest with aggregated rhombic elements. To achieve this purpose, we present an optimization formulation minimizing the sum of distances between each reference joint of an arbitrary shaped target area and its closest outer joints of foldable structure. To find out the outer joint set of a given foldable structure, an efficient geometric analysis method based on Delaunay triangulation is also developed and implemented. To show the validity and limitations of the present approach, several foldable structure design problems for two-dimensional arbitrary shaped target areas are solved with the present optimization procedure.

  1. Effectiveness of Land Use Structure Evolution to Industrial Structure Transformation

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Scarcity of land resources and transformation of industrial structure is a pair of contradictory elements.We derive the characteristics of land use structure and industrial structure transformation in Xining City using Transformation Coefficient(TC):first,in the period 1999-2000,the land use structure coefficient(θ1) declined by 79.55%,but the overall evolution trend is gentle;second,the transformation coefficient of industrial structure(θ2) tended to decline ceaselessly on the whole,a decrease of 36.09%(overall,the transformation coefficient of industrial structure is slightly greater than the land use structure coefficient);third,the inter-annual variation of the two experienced ups and downs(in the period 1999-2007,the inter-annual variation was great and in the period 2008-2010,the inter-annual variation tended to be gentle).On the basis of autocorrelation and co-integration model,we draw the following conclusions through analysis:first,the land use structure in Xining City plays a role in promoting industrial structure transformation;second,there is a long-term equilibrium relationship between the two.Finally,relevant policy recommendations are put forward for the industrial development in Xining City.

  2. Structural knowledge techniques for representing, conveying, and acquiring structural knowledge

    CERN Document Server

    Jonassen, David H; Beissner, Katherine; Yacci, Michael

    2013-01-01

    This book introduces the concept of a hypothetical type of knowledge construction -- referred to as structural knowledge -- that goes beyond traditional forms of information recall to provide the bases for knowledge application. Assuming that the validity of the concept is accepted, the volume functions as a handbook for supporting the assessment and use of structural knowledge in learning and instructional settings. It's descriptions are direct and short, and its structure is consistent. Almost all of the chapters describe a technique for representing and assessing structural knowledge acquis

  3. Structural characterization of nitrimyoglobin.

    Science.gov (United States)

    Bondoc, L L; Timkovich, R

    1989-04-15

    Nitrimyoglobin was formed in greater than 94% yield by a simple reaction between excess nitrite and horse heart metmyoglobin at pH 5.5. This dark green pigment was shown by 1H NMR spectroscopy to be a single, pure product with a well defined tertiary structure that is highly similar to the starting myoglobin. Electronic spin states parallel those of myoglobin, although the relaxation times differ. Ligand binding reactions of nitrimyoglobin parallel those of normal myoglobin, but lead to a unique series of UV-visible spectra. In the ferrous state, nitrimyoglobin reversibly binds O2 with half-saturation of sites at an O2 partial pressure of 10.4 +/- 1.4 mm Hg. 1H NMR data indicate that the altered heme of nitrimyoglobin has not undergone reaction at any meso proton position, nor has it been partially saturated to the level of a chlorin. 15N NMR spectra indicate that only a single nitrogen was added to the protein as a nitro group. Extraction of the modified heme from nitrimyoglobin and spectroscopic characterization of the nitriheme by infrared spectroscopy and of the free base porphyrin methyl ester derived from nitriheme by 1H NMR indicate that the modification is regiospecific. The heme in nitrimyoglobin is 3-(trans-2-nitrovinyl)-2,7,12,18-tetramethyl-8-vinylporphyrin-13,1 7-dipropionic acid. In the Fisher nomenclature scheme, the 2-vinyl substituent is the site of modification and has been converted to a nitrovinyl group by substitution of a proton by -NO2.

  4. Wave Overtopping of Marine Structures

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter

    defense structures. Optimization of structures utilizing wave overtopping for the production of electrical power has been ongoing throughout the last decade. It has been established that the information available in the existing literature is insufficient to describe overtopping of such structures......During the past 50 years tools for predicting wave overtopping of sea defense structures have continuously been refined. However, developers of wave energy converters have raised questions about how to predict the overtopping of structures with layouts significantly different from those of sea....... The present thesis describes investigations conducted against this background. The development of guidelines for calculating overtopping discharges for a wide variety of slope layouts is presented. Both structures with single and multi level reservoirs are examined. All geometries have been subjected...

  5. Plate shell structures of glass

    DEFF Research Database (Denmark)

    Bagger, Anne

    . This modelling technique is used to model a plate shell structure with a span of 11.5 meters in the FE software \\textsc{Abaqus}. The structure is analyzed with six different connection details with varying stiffness characteristics, to investigate the influence of these characteristics on the structural effects...... University, a script has been developed for an automated generation of a given plate shell geometry and a corresponding finite element (FE) model. A suitable FE modelling technique is proposed, suggesting a relatively simple method of modelling the connection detail's stiffness characteristics....... Based on these investigations, and FE analysis of other plate shell models, the structural behaviour is described. Possible methods of estimating the stresses in a given plate shell structure are proposed. The non-linear behaviour of a plate shell structure is investigated for varying parameters...

  6. Characterization of DPOAE fine structure

    DEFF Research Database (Denmark)

    Reuter, Karen; Hammershøi, Dorte

    2005-01-01

    , and has recently been demonstrated to exist in low level equal-loudness contours. The character of the DPOAE fine structure depends on several parameters, i.e., level, frequencies, and frequency of the two primaries, but also level and character of the noise floor. The prevalence and character of the fine......The distortion product otoacoustic emission (DPOAE) fine structure is revealed, when measuring DPOAE with a very fine frequency resolution. It is characterized by consistent maxima and minima with notches of up to 20 dB depth. The fine structure is known also from absolute hearing thresholds...... structures are highly individual, and till now no standardized method has been suggested for a consistent categorization. In the present paper a method developed for the categorization of fine structures is presented. The method has been used in two previous studies on the prevalence of fine structures, 1...

  7. Algorithms for Protein Structure Prediction

    DEFF Research Database (Denmark)

    Paluszewski, Martin

    -trace. Here we present three different approaches for reconstruction of C-traces from predictable measures. In our first approach [63, 62], the C-trace is positioned on a lattice and a tabu-search algorithm is applied to find minimum energy structures. The energy function is based on half-sphere-exposure (HSE......) is more robust than standard Monte Carlo search. In the second approach for reconstruction of C-traces, an exact branch and bound algorithm has been developed [67, 65]. The model is discrete and makes use of secondary structure predictions, HSE, CN and radius of gyration. We show how to compute good lower...... bounds for partial structures very fast. Using these lower bounds, we are able to find global minimum structures in a huge conformational space in reasonable time. We show that many of these global minimum structures are of good quality compared to the native structure. Our branch and bound algorithm...

  8. Algorithms for Protein Structure Prediction

    DEFF Research Database (Denmark)

    Paluszewski, Martin

    -trace. Here we present three different approaches for reconstruction of C-traces from predictable measures. In our first approach [63, 62], the C-trace is positioned on a lattice and a tabu-search algorithm is applied to find minimum energy structures. The energy function is based on half-sphere-exposure (HSE......) is more robust than standard Monte Carlo search. In the second approach for reconstruction of C-traces, an exact branch and bound algorithm has been developed [67, 65]. The model is discrete and makes use of secondary structure predictions, HSE, CN and radius of gyration. We show how to compute good lower...... bounds for partial structures very fast. Using these lower bounds, we are able to find global minimum structures in a huge conformational space in reasonable time. We show that many of these global minimum structures are of good quality compared to the native structure. Our branch and bound algorithm...

  9. Harmonic structures and intrinsic torsion

    DEFF Research Database (Denmark)

    Conti, Diego; Madsen, Thomas Bruun

    We discuss the construction of 8-manifolds with harmonic Sp(2)Sp(1)-structures. In particular, we find 10 new examples of nilmanifolds that admit a closed 4-form Omega whose stabiliser is Sp(2)Sp(1). Our constructions entail the notion of SO(4)-structures on 7-manifolds. We present a thorough inv...... investigation of the intrinsic torsion of such structures; in addition to the construction of harmonic structures, this analysis leads to explicit Lie group examples with invariant intrinsic torsion.......We discuss the construction of 8-manifolds with harmonic Sp(2)Sp(1)-structures. In particular, we find 10 new examples of nilmanifolds that admit a closed 4-form Omega whose stabiliser is Sp(2)Sp(1). Our constructions entail the notion of SO(4)-structures on 7-manifolds. We present a thorough...

  10. Correlating structural order with structural rearrangement in dusty plasma liquids: can structural rearrangement be predicted by static structural information?

    Science.gov (United States)

    Su, Yen-Shuo; Liu, Yu-Hsuan; I, Lin

    2012-11-09

    Whether the static microstructural order information is strongly correlated with the subsequent structural rearrangement (SR) and their predicting power for SR are investigated experimentally in the quenched dusty plasma liquid with microheterogeneities. The poor local structural order is found to be a good alarm to identify the soft spot and predict the short term SR. For the site with good structural order, the persistent time for sustaining the structural memory until SR has a large mean value but a broad distribution. The deviation of the local structural order from that averaged over nearest neighbors serves as a good second alarm to further sort out the short time SR sites. It has the similar sorting power to that using the temporal fluctuation of the local structural order over a small time interval.

  11. Structure of giant muscle proteins

    Directory of Open Access Journals (Sweden)

    Nathan Thompson Wright

    2013-12-01

    Full Text Available Giant muscle proteins (e.g. titin, nebulin, and obscurin play a seminal role in muscle elasticity, stretch response, and sarcomeric organization. Each giant protein consists of multiple tandem structural domains, usually arranged in a modular fashion ranging from 500 kDa to 4 MDa. Although many of the domains are similar in structure, subtle differences create a unique function of each domain. Recent high and low resolution structural and dynamic studies now suggest more nuanced overall protein structures than previously realized. These findings show that atomic structure, interactions between tandem domains, and intrasarcomeric environment all influence the shape, motion, and therefore function of giant proteins. In this article we will review the current understanding of titin, obscurin, and nebulin structure, from the atomic level through the molecular level.

  12. Crystal structure refinement with SHELXL.

    Science.gov (United States)

    Sheldrick, George M

    2015-01-01

    The improvements in the crystal structure refinement program SHELXL have been closely coupled with the development and increasing importance of the CIF (Crystallographic Information Framework) format for validating and archiving crystal structures. An important simplification is that now only one file in CIF format (for convenience, referred to simply as `a CIF') containing embedded reflection data and SHELXL instructions is needed for a complete structure archive; the program SHREDCIF can be used to extract the .hkl and .ins files required for further refinement with SHELXL. Recent developments in SHELXL facilitate refinement against neutron diffraction data, the treatment of H atoms, the determination of absolute structure, the input of partial structure factors and the refinement of twinned and disordered structures. SHELXL is available free to academics for the Windows, Linux and Mac OS X operating systems, and is particularly suitable for multiple-core processors.

  13. Crystal structure refinement with SHELXL

    Energy Technology Data Exchange (ETDEWEB)

    Sheldrick, George M., E-mail: gsheldr@shelx.uni-ac.gwdg.de [Department of Structural Chemistry, Georg-August Universität Göttingen, Tammannstraße 4, Göttingen 37077 (Germany)

    2015-01-01

    New features added to the refinement program SHELXL since 2008 are described and explained. The improvements in the crystal structure refinement program SHELXL have been closely coupled with the development and increasing importance of the CIF (Crystallographic Information Framework) format for validating and archiving crystal structures. An important simplification is that now only one file in CIF format (for convenience, referred to simply as ‘a CIF’) containing embedded reflection data and SHELXL instructions is needed for a complete structure archive; the program SHREDCIF can be used to extract the .hkl and .ins files required for further refinement with SHELXL. Recent developments in SHELXL facilitate refinement against neutron diffraction data, the treatment of H atoms, the determination of absolute structure, the input of partial structure factors and the refinement of twinned and disordered structures. SHELXL is available free to academics for the Windows, Linux and Mac OS X operating systems, and is particularly suitable for multiple-core processors.

  14. Water's quantum structures and life.

    Science.gov (United States)

    Germano, Roberto

    2015-01-01

    This article discusses several clues pointing to the spontaneous quantum origin of the recently discovered dissipative structures induced in liquid water by low-energy physical perturbations. These structures show an astonishing permanence, so much that large ponderal quantities of supramolecular aggregates of water - at ambient pressure and temperature - subsist even in the solid phase, strongly suggesting the possibility that these structures are the matrix itself of life.

  15. The structures of noncrystalline rocks

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The structural studies of noncrystalline rocks by total radial distribution function (RDF) which was derived from the wide angular X-ray scattering (WAXS) have been reported. In order to make a further study of the structural features shown by RDF, the unsymmetric peaks in total RDF were separated into the approximately symmetric peaks by the multi-peaks separation processing. By analyzing the relationship of the peak parameters with the compositions, the information of further structures has been discussed.

  16. Dynamic testing of cable structures

    Directory of Open Access Journals (Sweden)

    Caetano Elsa

    2015-01-01

    Full Text Available The paper discusses the role of dynamic testing in the study of cable structures. In this context, the identification of cable force based on vibration measurements is discussed. Vibration and damping assessment are then introduced as the focus of dynamic monitoring systems, and particular aspects of the structural behaviour under environmental loads are analysed. Diverse application results are presented to support the discussion centred on cable-stayed bridges, roof structures, a guyed mast and a transmission line.

  17. Structural Dynamics of Maneuvering Aircraft.

    Science.gov (United States)

    1987-09-01

    AD-RI92 376 STRUCTURAL DYNAMICS OF MANEUVERING RIRCRAFT(U) CONRAD I TECHNOLOGIES INC KING OF PRUSSIA PR M M REDDI SEP 97 CTI-8601 NRDC-88014-69...REPORT NO. NADC-8014-60 STRUCTURAL DYNAMICS OF MANEUVERING AIRCRAFT M. Mahadeva Reddi .4 Conrad Technologies, Inc. 650 S. Henderson Rd. D T IQ King of...NO A0 CCESSION NO. R02303001 107601 11. TITLE (Include Security Classfication) (u) STRUCTURAL DYNAMICS OF MANEUVERING AIRCRAFT 12. PERSONAL AUTHORS) M

  18. Inorganic Crystal Structure Database (ICSD)

    Science.gov (United States)

    SRD 84 FIZ/NIST Inorganic Crystal Structure Database (ICSD) (PC database for purchase)   The Inorganic Crystal Structure Database (ICSD) is produced cooperatively by the Fachinformationszentrum Karlsruhe(FIZ) and the National Institute of Standards and Technology (NIST). The ICSD is a comprehensive collection of crystal structure data of inorganic compounds containing more than 140,000 entries and covering the literature from 1915 to the present.

  19. Self-Deployable Membrane Structures

    Science.gov (United States)

    Sokolowski, Witold M.; Willis, Paul B.; Tan, Seng C.

    2010-01-01

    Currently existing approaches for deployment of large, ultra-lightweight gossamer structures in space rely typically upon electromechanical mechanisms and mechanically expandable or inflatable booms for deployment and to maintain them in a fully deployed, operational configuration. These support structures, with the associated deployment mechanisms, launch restraints, inflation systems, and controls, can comprise more than 90 percent of the total mass budget. In addition, they significantly increase the stowage volume, cost, and complexity. A CHEM (cold hibernated elastic memory) membrane structure without any deployable mechanism and support booms/structure is deployed by using shape memory and elastic recovery. The use of CHEM micro-foams reinforced with carbon nanotubes is considered for thin-membrane structure applications. In this advanced structural concept, the CHEM membrane structure is warmed up to allow packaging and stowing prior to launch, and then cooled to induce hibernation of the internal restoring forces. In space, the membrane remembers its original shape and size when warmed up. After the internal restoring forces deploy the structure, it is then cooled to achieve rigidization. For this type of structure, the solar radiation could be utilized as the heat energy used for deployment and space ambient temperature for rigidization. The overall simplicity of the CHEM self-deployable membrane is one of its greatest assets. In present approaches to space-deployable structures, the stow age and deployment are difficult and challenging, and introduce a significant risk, heavy mass, and high cost. Simple procedures provided by CHEM membrane greatly simplify the overall end-to-end process for designing, fabricating, deploying, and rigidizing large structures. The CHEM membrane avoids the complexities associated with other methods for deploying and rigidizing structures by eliminating deployable booms, deployment mechanisms, and inflation and control systems

  20. Generalized Double Ring Network Structures

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Patel, A.; Knudsen, Thomas Phillip

    2004-01-01

    of these structures are shown, indicating that they forma suitable base for future access network infrastructures. The first result is that every N2R(p; q; r) structure is isomorphic to a N2R(p; q) structure N2R(p; q'), and it is shown how q' is determined. Consequently, the rest of the paper focuses on the N2R(p; q...

  1. Bridge Aesthetics and Structural Honesty

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    In bridges the overall form must be chosen with due respect to the transmission of forces if efficient structures shall be created, The design must therefore be governed by experienced structural engineers - in some cases assisted by aesthetic advisers on specific issues. Some basic requirements...... decisive for choosing the form of trusses, arches and cable-stayed bridges are outlined, and several examples show bridges designed without giving priority to the structural aspects....

  2. Harmonic structures and intrinsic torsion

    DEFF Research Database (Denmark)

    Conti, Diego; Madsen, Thomas Bruun

    2015-01-01

    We discuss the construction of Sp(2)Sp(1)-structures whose fundamental form is closed. In particular, we find 10 new examples of 8-dimensional nilmanifolds that admit an invariant closed 4-form with stabiliser Sp(2) Sp(1). Our constructions entail the notion of SO(4)-structures on 7-manifolds. We...... present a thorough investigation of the intrinsic torsion of such structures, leading to the construction of explicit Lie group examples with invariant intrinsic torsion....

  3. European Research in Marine Structures

    DEFF Research Database (Denmark)

    Soares, C.Guedes; Jensen, Jørgen Juncher; Incecik, A.

    2012-01-01

    An overview is presented of the results obtained in Europe by a network with a large number of research groups in the field of Marine Structures during a period of 6 years. The European Union has funded a project aimed at improving the collaboration among European research groups specialized...... in marine structures, which has led, among other results to a number of benchmark studies organized in 6 main topical areas, namely, Methods and Tools for Loads and Load Effects, Methods and Tools for Strength Assessment, Experimental Analysis of Structures, Materials and Fabrication of Structures, Methods...

  4. Quasicrystalline structures and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Steinhardt, Paul Joseph; Chaikin, Paul Michael; Man, Weining

    2017-02-14

    This invention relates generally to the field of quasicrystalline structures. In preferred embodiments, the stopgap structure is more spherically symmetric than periodic structures facilitating the formation of stopgaps in nearly all directions because of higher rotational symmetries. More particularly, the invention relates to the use of quasicrystalline structures for optical, mechanical, electrical and magnetic purposes. In some embodiments, the invention relates to manipulating, controlling, modulating and directing waves including electromagnetic, sound, spin, and surface waves, for pre-selected range of wavelengths propagating in multiple directions.

  5. Self deployable deorbiting space structure

    DEFF Research Database (Denmark)

    2012-01-01

    -active or heavy device has to be brought on board the spacecraft for deploying the space structure. Allows the deployed flexible sheet surface higher than the case when SDSS is rigidly linked at the short distance from carrier structure. Ensures a reliable unfolding of deorbiting structures in zero gravity....... Provides the strain energy provoking the deployment without the need of addition of energy to the system. Eliminates the issues around successful unfolding known from other technical solutions as the frame unfolds automatically without using external energy for unfolding by using the accumulated strain...... energy in stressed configuration. Ensures that deorbiting space structure can be efficiently folded without intervention of active unfolding device....

  6. Open data structures an introduction

    CERN Document Server

    Morin, Pat

    2014-01-01

    Offered as an introduction to the field of data structures and algorithms, Open Data Structures covers the implementation and analysis of data structures for sequences (lists), queues, priority queues, unordered dictionaries, ordered dictionaries, and graphs. Analyzed and implemented in Java, with a mathematically rigorous approach, Morin clearly and briskly presents instruction along with source code. A modern treatment of an essential computer science topic, this text is a measured balance between classical topics and state-of-the-art structures that will serve the needs of all undergraduate

  7. Toolbox for Protein Structure Prediction.

    Science.gov (United States)

    Roche, Daniel Barry; McGuffin, Liam James

    2016-01-01

    Protein tertiary structure prediction algorithms aim to predict, from amino acid sequence, the tertiary structure of a protein. In silico protein structure prediction methods have become extremely important, as in vitro-based structural elucidation is unable to keep pace with the current growth of sequence databases due to high-throughput next-generation sequencing, which has exacerbated the gaps in our knowledge between sequences and structures.Here we briefly discuss protein tertiary structure prediction, the biennial competition for the Critical Assessment of Techniques for Protein Structure Prediction (CASP) and its role in shaping the field. We also discuss, in detail, our cutting-edge web-server method IntFOLD2-TS for tertiary structure prediction. Furthermore, we provide a step-by-step guide on using the IntFOLD2-TS web server, along with some real world examples, where the IntFOLD server can and has been used to improve protein tertiary structure prediction and aid in functional elucidation.

  8. Optimal Investment in Structured Bonds

    DEFF Research Database (Denmark)

    Jessen, Pernille; Jørgensen, Peter Løchte

    The paper examines the role of structured bonds in the optimal portfolio of a small retail investor. We consider the typical structured bond essentially repacking an exotic option and a zero coupon bond, i.e. an investment with portfolio insurance. The optimal portfolio is found when the investment...... opportunities consist of a risky reference fund, a risk-free asset and a structured bond. Key model elements are the trading strategy and utility function of the investor. Our numerical results indicate structured bonds do have basis for consideration in the optimal portfolio. The product holdings...

  9. Optimal Investment in Structured Bonds

    DEFF Research Database (Denmark)

    Jessen, Pernille; Jørgensen, Peter Løchte

    2012-01-01

    and consider different utility functions and trading strategies. Our results show that investors should include structured bonds in their optimal portfolio only if they cannot access the index underlying the option directly and only if the products then provide sufficient diversification to compensate......Retail structured products regularly receive much criticism from financial experts but seem to remain popular with investors. This article considers a generic structured product: the principal-protected index-linked note (structured bond), which resembles a portfolio insurance contract. The purpose...

  10. SYMPLECTIC STRUCTURE OF POISSON SYSTEM

    Institute of Scientific and Technical Information of China (English)

    SUN Jian-qiang; MA Zhong-qi; TIAN Yi-min; QIN Meng-zhao

    2005-01-01

    When the Poisson matrix of Poisson system is non-constant, classical symplectic methods, such as symplectic Runge-Kutta method, generating function method, cannot preserve the Poisson structure. The non-constant Poisson structure was transformed into the symplectic structure by the nonlinear transform.Arbitrary order symplectic method was applied to the transformed Poisson system. The Euler equation of the free rigid body problem was transformed into the symplectic structure and computed by the mid-point scheme. Numerical results show the effectiveness of the nonlinear transform.

  11. Plate shell structures of glass

    DEFF Research Database (Denmark)

    Bagger, Anne

    to their curved shape. A plate shell structure maintains a high stiffness-to-weight ratio, while facilitating the use of plane structural elements. The study focuses on using laminated glass panes for the load bearing facets. Various methods of generating a plate shell geometry are suggested. Together with Ghent......, such as facet size, imperfections, and connection characteristics. The critical load is compared to that of a similar, but smoothly curved, shell structure. Based on the investigations throughout the study, a set of guidelines for the structural design of plate shells of glass is proposed....

  12. Porous Materials - Structure and Properties

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1997-01-01

    The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete and the p......The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete...

  13. Smart Sensors Assess Structural Health

    Science.gov (United States)

    2010-01-01

    NASA frequently inspects launch vehicles, fuel tanks, and other components for structural damage. To perform quick evaluation and monitoring, the Agency pursues the development of structural health monitoring systems. In 2001, Acellent Technologies Inc., of Sunnyvale, California, received Small Business Innovation Research (SBIR) funding from Marshall Space Flight Center to develop a hybrid Stanford Multi-Actuator Receiver Transduction (SMART) Layer for aerospace vehicles and structures. As a result, Acellent expanded the technology's capability and now sells it to aerospace and automotive companies; construction, energy, and utility companies; and the defense, space, transportation, and energy industries for structural condition monitoring, damage detection, crack growth monitoring, and other applications.

  14. Data Mining of Macromolecular Structures.

    Science.gov (United States)

    van Beusekom, Bart; Perrakis, Anastassis; Joosten, Robbie P

    2016-01-01

    The use of macromolecular structures is widespread for a variety of applications, from teaching protein structure principles all the way to ligand optimization in drug development. Applying data mining techniques on these experimentally determined structures requires a highly uniform, standardized structural data source. The Protein Data Bank (PDB) has evolved over the years toward becoming the standard resource for macromolecular structures. However, the process selecting the data most suitable for specific applications is still very much based on personal preferences and understanding of the experimental techniques used to obtain these models. In this chapter, we will first explain the challenges with data standardization, annotation, and uniformity in the PDB entries determined by X-ray crystallography. We then discuss the specific effect that crystallographic data quality and model optimization methods have on structural models and how validation tools can be used to make informed choices. We also discuss specific advantages of using the PDB_REDO databank as a resource for structural data. Finally, we will provide guidelines on how to select the most suitable protein structure models for detailed analysis and how to select a set of structure models suitable for data mining.

  15. Structural complexity of quantum networks

    Energy Technology Data Exchange (ETDEWEB)

    Siomau, Michael [Physics Department, Jazan University, P.O.Box 114, 45142 Jazan (Saudi Arabia); Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany)

    2016-06-10

    Quantum network is a set of nodes connected with channels, through which the nodes communicate photons and classical information. Classical structural complexity of a quantum network may be defined through its physical structure, i.e. mutual position of nodes and channels connecting them. We show here that the classical structural complexity of a quantum network does not restrict the structural complexity of entanglement graphs, which may be created in the quantum network with local operations and classical communication. We show, in particular, that 1D quantum network can simulate both simple entanglement graphs such as lattices and random graphs and complex small-world graphs.

  16. Magic Numbers in Protein Structures

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker; Bohr, Henrik

    1996-01-01

    A homology measure for protein fold classes has been constructed by locally projecting consecutive secondary structures onto a lattice. Taking into account hydrophobic forces we have found a mechanism for formation of domains containing magic numbers of secondary structures and multipla of these ......A homology measure for protein fold classes has been constructed by locally projecting consecutive secondary structures onto a lattice. Taking into account hydrophobic forces we have found a mechanism for formation of domains containing magic numbers of secondary structures and multipla...

  17. Microstrip microwave band gap structures

    Indian Academy of Sciences (India)

    V Subramanian

    2008-04-01

    Microwave band gap structures exhibit certain stop band characteristics based on the periodicity, impedance contrast and effective refractive index contrast. These structures though formed in one-, two- and three-dimensional periodicity, are huge in size. In this paper, microstrip-based microwave band gap structures are formed by removing the substrate material in a periodic manner. This paper also demonstrates that these structures can serve as a non-destructive characterization tool for materials, a duplexor and frequency selective coupler. The paper presents both experimental results and theoretical simulation based on a commercially available finite element methodology for comparison.

  18. The electronic structures of solids

    CERN Document Server

    Coles, B R

    2013-01-01

    The Electronic Structures of Solids aims to provide students of solid state physics with the essential concepts they will need in considering properties of solids that depend on their electronic structures and idea of the electronic character of particular materials and groups of materials. The book first discusses the electronic structure of atoms, including hydrogen atom and many-electron atom. The text also underscores bonding between atoms and electrons in metals. Discussions focus on bonding energies and structures in the solid elements, eigenstates of free-electron gas, and electrical co

  19. Can Intonational Phrase Structure Be Primed (Like Syntactic Structure)?

    Science.gov (United States)

    Tooley, Kristen M.; Konopka, Agnieszka E.; Watson, Duane G.

    2014-01-01

    In 3 experiments, we investigated whether intonational phrase structure can be primed. In all experiments, participants listened to sentences in which the presence and location of intonational phrase boundaries were manipulated such that the recording included either no intonational phrase boundaries, a boundary in a structurally dispreferred…

  20. Capital Structure Determinants and Governance Structure Variety in Franchising

    NARCIS (Netherlands)

    T. Jiang (Tao)

    2009-01-01

    textabstractThis thesis investigates two questions: the determinants of capital structure in franchising and its subsequent impact on the franchise financing decisions; and the efficient governance structure choice in franchising. We posit that firms franchise in order to benefit from the reduced fr