WorldWideScience

Sample records for astatotilapia burtoni structure

  1. Tol2-mediated generation of a transgenic haplochromine cichlid, Astatotilapia burtoni.

    Directory of Open Access Journals (Sweden)

    Scott A Juntti

    Full Text Available Cichlid fishes represent one of the most species-rich and rapid radiations of a vertebrate family. These ~2200 species, predominantly found in the East African Great Lakes, exhibit dramatic differences in anatomy, physiology, and behavior. However, the genetic bases for this radiation, and for the control of their divergent traits, are unknown. A flood of genomic and transcriptomic data promises to suggest mechanisms underlying the diversity, but transgenic technology will be needed to rigorously test the hypotheses generated. Here we demonstrate the successful use of the Tol2 transposon system to generate transgenic Astatotilapia burtoni, a haplochromine cichlid from Lake Tanganyika, carrying the GFP transgene under the control of the ubiquitous EF1α promoter. The transgene integrates into the genome, is successfully passed through the germline, and the widespread GFP expression pattern is stable across siblings and multiple generations. The stable inheritance and expression patterns indicate that the Tol2 system can be applied to generate A. burtoni transgenic lines. Transgenesis has proven to be a powerful technology for manipulating genes and cells in other model organisms and we anticipate that transgenic A. burtoni and other cichlids will be used to test the mechanisms underlying behavior and speciation.

  2. Annotation of expressed sequence tags for the East African cichlid fish Astatotilapia burtoni and evolutionary analyses of cichlid ORFs

    Directory of Open Access Journals (Sweden)

    Braasch Ingo

    2008-02-01

    Full Text Available Abstract Background The cichlid fishes in general, and the exceptionally diverse East African haplochromine cichlids in particular, are famous examples of adaptive radiation and explosive speciation. Here we report the collection and annotation of more than 12,000 expressed sequence tags (ESTs generated from three different cDNA libraries obtained from the East African haplochromine cichlid species Astatotilapia burtoni and Metriaclima zebra. Results We first annotated more than 12,000 newly generated cichlid ESTs using the Gene Ontology classification system. For evolutionary analyses, we combined these ESTs with all available sequence data for haplochromine cichlids, which resulted in a total of more than 45,000 ESTs. The ESTs represent a broad range of molecular functions and biological processes. We compared the haplochromine ESTs to sequence data from those available for other fish model systems such as pufferfish (Takifugu rubripes and Tetraodon nigroviridis, trout, and zebrafish. We characterized genes that show a faster or slower rate of base substitutions in haplochromine cichlids compared to other fish species, as this is indicative of a relaxed or reinforced selection regime. Four of these genes showed the signature of positive selection as revealed by calculating Ka/Ks ratios. Conclusion About 22% of the surveyed ESTs were found to have cichlid specific rate differences suggesting that these genes might play a role in lineage specific characteristics of cichlids. We also conclude that the four genes with a Ka/Ks ratio greater than one appear as good candidate genes for further work on the genetic basis of evolutionary success of haplochromine cichlid fishes.

  3. Evolution of genomic structural variation and genomic architecture in the adaptive radiations of African cichlid fishes

    Directory of Open Access Journals (Sweden)

    Shaohua eFan

    2014-06-01

    Full Text Available African cichlid fishes are an ideal system for studying explosive rates of speciation and the origin of diversity in adaptive radiation. Within the last few million years, more than 2000 species have evolved in the Great Lakes of East Africa, the largest adaptive radiation in vertebrates. These young species show spectacular diversity in their coloration, morphology and behavior. However, little is known about the genomic basis of this astonishing diversity. Recently, five African cichlid genomes were sequenced, including that of the Nile tilapia (Oreochromis niloticus, a basal and only relatively moderately diversified lineage, and the genomes of four representative endemic species of the adaptive radiations, Neolamprologus brichardi, Astatotilapia burtoni, Metriaclima zebra, and Pundamila nyererei. Using the tilapia genome as the reference genome, we generated a high-resolution genomic variation map, consisting of single nucleotide polymorphisms (SNPs, short insertions and deletions (indels, inversions and deletions. In total, around 18.8, 17.7, 17.0 and 17.0 million SNPs, 2.3, 2.2, 1.4 and 1.9 million indels, 262, 306, 162, and 154 inversions, and 3509, 2705, 2710 and 2634 deletions were inferred to have evolved in the N. brichardi, A. burtoni, P. nyererei and M. zebra respectively. Many of these variations affected the annotated gene regions in the genome. Different patterns of genetic variation were detected during the adaptive radiation of African cichlid fishes. For SNPs, the highest rate of evolution was detected in the common ancestor of N. brichardi, A. burtoni, P. nyererei and M. zebra. However, for the evolution of inversions and deletions, we found that the rates at the terminal taxa are substantially higher than the rates at the ancestral lineages. The high-resolution map provides an ideal opportunity to understand the genomic bases of the adaptive radiation of African cichlid fishes.

  4. Fish & Chips: Functional Genomics of Social Plasticity in an African Cichlid Fish

    OpenAIRE

    Renn, Susan C.P.; Aubin-Horth, Nadia; Hofmann, Hans A.

    2008-01-01

    Behaviour and physiology are regulated by both environment and social context. A central goal in the study of the social control of behaviour is to determine the underlying physiological, cellular and molecular mechanisms in the brain. The African cichlid fish Astatotilapia burtoni has long been used as a model system to study how social interactions regulate neural and behavioural plasticity. In this species, males are either socially dominant and reproductively active or subordinate and rep...

  5. Gut Microbiota Dynamics during Dietary Shift in Eastern African Cichlid Fishes.

    Directory of Open Access Journals (Sweden)

    Laura Baldo

    Full Text Available The gut microbiota structure reflects both a host phylogenetic history and a signature of adaptation to the host ecological, mainly trophic niches. African cichlid fishes, with their array of closely related species that underwent a rapid dietary niche radiation, offer a particularly interesting system to explore the relative contribution of these two factors in nature. Here we surveyed the host intra- and interspecific natural variation of the gut microbiota of five cichlid species from the monophyletic tribe Perissodini of lake Tanganyika, whose members transitioned from being zooplanktivorous to feeding primarily on fish scales. The outgroup riverine species Astatotilapia burtoni, largely omnivorous, was also included in the study. Fusobacteria, Firmicutes and Proteobacteria represented the dominant components in the gut microbiota of all 30 specimens analysed according to two distinct 16S rRNA markers. All members of the Perissodini tribe showed a homogenous pattern of microbial alpha and beta diversities, with no significant qualitative differences, despite changes in diet. The recent diet shift between zooplantkon- and scale-eaters simply reflects on a significant enrichment of Clostridium taxa in scale-eaters where they might be involved in the scale metabolism. Comparison with the omnivorous species A. burtoni suggests that, with increased host phylogenetic distance and/or increasing herbivory, the gut microbiota begins differentiating also at qualitative level. The cichlids show presence of a large conserved core of taxa and a small set of core OTUs (average 13-15%, remarkably stable also in captivity, and putatively favoured by both restricted microbial transmission among related hosts (putatively enhanced by mouthbrooding behavior and common host constraints. This study sets the basis for a future large-scale investigation of the gut microbiota of cichlids and its adaptation in the process of the host adaptive radiation.

  6. Females of an African cichlid fish display male-typical social dominance behavior and elevated androgens in the absence of males.

    Science.gov (United States)

    Renn, Suzy C P; Fraser, Eleanor J; Aubin-Horth, Nadia; Trainor, Brian C; Hofmann, Hans A

    2012-04-01

    Social environment can affect the expression of sex-typical behavior in both males and females. Males of the African cichlid species Astatotilapia burtoni have long served as a model system to study the neural, endocrine, and molecular basis of socially plastic dominance behavior. Here we show that in all-female communities of A. burtoni, some individuals acquire a male-typical dominance phenotype, including aggressive territorial defense, distinctive color patterns, and courtship behavior. Furthermore, dominant females have higher levels of circulating androgens than either subordinate females or females in mixed-sex communities. These male-typical traits do not involve sex change, nor do the social phenotypes in all-female communities differ in relative ovarian size, suggesting that factors other than gonadal physiology underlie much of the observed variation. In contrast to the well-studied situation in males, dominant and subordinate females do not differ in the rate of somatic growth. Dominant females are not any more likely than subordinates to spawn with an introduced male, although they do so sooner. These results extend the well known extraordinary behavioral plasticity of A. burtoni to the females of this species and provide a foundation for uncovering the neural and molecular basis of social dominance behavior while controlling for factors such as sex, gonadal state and growth. PMID:22285646

  7. Dicty_cDB: Contig-U11364-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available Q630738_1( DQ630738 |pid:none) Astatotilapia burtoni heterogeneou... 60 2e-07 AX885129_1( AX885129 |pid:none...84487 |pid:none) Xenopus tropicalis heterogeneous n... 66 3e-09 CP001108_1196( CP001108 |pid:none) Prosthecochloris aestuari...:none) Drosophila melanogaster chromos... 60 1e-07 AF288041_1( AF288041 |pid:none) Oryzias latipes splicing ..._1( D26182 |pid:none) Nicotiana sylvestris mRNA for RNA-bind... 60 2e-07 BT083094_1( BT083094 |pid:none) Anoplopoma fimbria...r 12.0 %: Golgi 8.0 %: cytoskeletal 8.0 %: mitochondrial 4.0 %: vacuolar 4.0 %: endoplasmic reticulum >> pre

  8. Cobalt Chloride Treatment Used to Ablate the Lateral Line System Also Impairs the Olfactory System in Three Freshwater Fishes.

    Directory of Open Access Journals (Sweden)

    Julie M Butler

    Full Text Available Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of

  9. Two types of dominant male cichlid fish: behavioral and hormonal characteristics.

    Science.gov (United States)

    Alcazar, Rosa M; Becker, Lisa; Hilliard, Austin T; Kent, Kai R; Fernald, Russell D

    2016-01-01

    Male African cichlid fish, Astatotilapia burtoni, have been classified as dominant or subordinate, each with unique behavioral and endocrine profiles. Here we characterize two distinct subclasses of dominant males based on types of aggressive behavior: (1) males that display escalating levels of aggression and court females while they establish a territory, and (2) males that display a stable level of aggression and delay courting females until they have established a territory. To profile differences in their approach to a challenge, we used an intruder assay. In every case, there was a male-male confrontation between the resident dominant male and the intruder, with the intruder quickly taking a subordinate role. However, we found that dominant males with escalating aggression spent measurably more time attacking subordinates than did dominant males with stable aggression that instead increased their attention toward the females in their tank. There was no difference in the behavior of intruders exposed to either type of dominant male, suggesting that escalating aggression is an intrinsic characteristic of some dominant males and is not elicited by the behavior of their challengers. Male behavior during the first 15 min of establishing a territory predicts their aggressive class. These two types of dominant males also showed distinctive physiological characteristics. After the intruder assay, males with escalating aggression had elevated levels of 11-ketotestosterone (11-KT), testosterone, estradiol, and cortisol, while those with stable aggression did not. These observations show that the same stimulus can elicit different behavioral and endocrine responses among A. burtoni dominant males that characterize them as either escalating or stable aggressive types. Our ability to identify which individuals within a population have escalating levels of aggressive responses versus those which have stable levels of aggressive responses when exposed to the same stimulus

  10. Social and ecological regulation of a decision-making circuit.

    Science.gov (United States)

    Neumeister, H; Whitaker, K W; Hofmann, H A; Preuss, T

    2010-12-01

    Ecological context, sensory inputs, and the internal physiological state are all factors that need to be integrated for an animal to make appropriate behavioral decisions. However, these factors have rarely been studied in the same system. In the African cichlid fish Astatotilapia burtoni, males alternate between two phenotypes based on position in a social hierarchy. When dominant (DOM), fish display bright body coloration and a wealth of aggressive and reproductive behavioral patterns that make them conspicuous to predators. Subordinate (SUB) males, on the other hand, decrease predation risk by adopting cryptic coloration and schooling behavior. We therefore hypothesized that DOMs would show enhanced startle-escape responsiveness to compensate for their increased predation risk. Indeed, behavioral responses to sound clicks of various intensities showed a significantly higher mean startle rate in DOMs compared with SUBs. Electrophysiological recordings from the Mauthner cells (M-cells), the neurons triggering startle, were performed in anesthetized animals and showed larger synaptic responses to sound clicks in DOMs, consistent with the behavioral results. In addition, the inhibitory drive mediated by interneurons (passive hyperpolarizing potential [PHP] cells) presynaptic to the M-cell was significantly reduced in DOMs. Taken together, the results suggest that the likelihood for an escape to occur for a given auditory stimulus is higher in DOMs because of a more excitable M-cell. More broadly, this study provides an integrative explanation of an ecological and social trade-off at the level of an identifiable decision-making neural circuit. PMID:20926612

  11. Structural cladding /clad structures:

    DEFF Research Database (Denmark)

    Beim, Anne

    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 and...

  12. Structural cladding /clad structures

    DEFF Research Database (Denmark)

    Beim, Anne

    2012-01-01

    Structural Cladding /Clad Structures: Studies in Tectonic Building Practice A. Beim CINARK – Centre for Industrialized Architecture, Institute of Architectural Technology, The Royal Danish Academy of Fine Arts School of Architecture, Copenhagen, Denmark ABSTRACT: With point of departure...... 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...... tightness in constructions. At the same time a need for longevity and effortless maintenance have lead to contemporary architectural structures, where the exterior walls and the building envelope most often are made of several layers of advanced materials and separate building elements. In most contemporary...

  13. Social Transitions Cause Rapid Behavioral and Neuroendocrine Changes.

    Science.gov (United States)

    Maruska, Karen P

    2015-08-01

    In species that form dominance hierarchies, there are often opportunities for low-ranking individuals to challenge high-ranking ones, resulting in a rise or fall in social rank. How does an animal rapidly detect, process, and then respond to these social transitions? This article explores and summarizes how these social transitions can rapidly (within 24 h) impact an individual's behavior, physiology, and brain, using the African cichlid fish, Astatotilapia burtoni, as a model. Male A. burtoni form hierarchies in which a few brightly-colored dominant males defend territories and spawn with females, while the remaining males are subordinate, more drab-colored, do not hold a territory, and have minimal opportunities for reproduction. These social phenotypes are plastic and reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. When the social environment is manipulated to create males that either ascend (subordinate to dominant) or descend (dominant to subordinate) in rank, there are rapid changes in behavior, circulating hormones, and levels of gene expression in the brain that reflect the direction of transition. For example, within minutes, males ascending in status show bright coloration, a distinct eye-bar, increased dominance behaviors, activation of brain nuclei in the social behavior network, and higher levels of sex steroids in the plasma. Ascending males also show rapid changes in levels of neuropeptide and steroid receptors in the brain, as well as in the pituitary and testes. To further examine hormone-behavior relationships in this species during rapid social ascent, the present study also measured levels of testosterone, 11-ketotestosterone, estradiol, progestins, and cortisol in the plasma during the first week of social ascent and tested for correlations with behavior. Plasma levels of all steroids were rapidly increased at 30 min after social ascent, but were not correlated with

  14. Cell Structure

    Science.gov (United States)

    ... Thyroid & Parathyroid Glands Adrenal Gland Pancreas Gonads Other Endocrine Glands Review Quiz Cardiovascular System Heart Structure of the Heart Physiology of the Heart Blood Classification & Structure of Blood ...

  15. Various structures

    Czech Academy of Sciences Publication Activity Database

    Shet, H.; Rodas, G.S.; De Filippis, L.; Billi, A.; Ellis, A.; Soto, R.; Izquierdo-Llavall, E.; Mathew, G.; Fagereng, A.; Pueyo, E.L.; Nováková, Lucie

    Amsterdam: Elsevier, 2015 - (Mukherjee, S.), s. 125-158 ISBN 978-0-12-420152-1 Institutional support: RVO:67985891 Keywords : columnar joints * crater * fissures * fractures * pull apart structure Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  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. Structural Unemployment

    OpenAIRE

    Benedikt Herz; Thijs van Rens

    2011-01-01

    Structural unemployment is due to mismatch between available jobs and workers. We formalize this concept in a simple model of a segmented labor market with search frictions within segments. Worker mobility, job mobility and wage bargaining costs across segments generate structural unemployment. We estimate the contribution of these costs to fluctuations in US unemployment, operationalizing segments as states or industries. Most structural unemployment is due to wage bargaining costs, which ar...

  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. Structural Ceramics

    Science.gov (United States)

    1986-01-01

    This publication is a compilation of abstracts and slides of papers presented at the NASA Lewis Structural Ceramics Workshop. Collectively, these papers depict the scope of NASA Lewis' structural ceramics program. The technical areas include monolithic SiC and Si3N4 development, ceramic matrix composites, tribology, design methodology, nondestructive evaluation (NDE), fracture mechanics, and corrosion.

  1. Scintillator structure

    International Nuclear Information System (INIS)

    A scintillator structure comprises at least one layer of transparent fused quartz with a phosphor coating on one or both sides adjacent to at least one transparent layer of epoxy resin which directs light from the phosphor to a detector. The phosphor layer may be formed from a powder optionally with a binder, a single crystal or a melt, or by evaporation or sintering. A plurality of multiple layers may be used or the structure tilted for greater absorption. The structure may be surrounded by another such structure optionally operating in cascade with the first. Many phosphors are specified. A scintillator structure comprises phosphor particles dispersed in epoxy resin or copoly imide-silicone and cast in a multi-compartment box with long sides transparent to X-rays and dividers opaque to X-rays. (UK)

  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...... 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 and...

  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.......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. 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 ...

  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. Graphite structures

    International Nuclear Information System (INIS)

    Design criteria and operating experience of nuclear reactor graphite structures are reviewed on the basis of publications available since as early as 1954. Typical spatial distributions of temperature and neutron fluence are presented. Design features are discussed of graphite cores of the First-in-the-world NPP, the IR reactor, the Beloyarsk NPP, the RBMK reactor (all lwgr type), as well as of some GCR and HTGR type reactors now in operation in the U.S.A., Great Britain and the FRG. The improvement of graphite structure designs and their operating regimes take place through the development of means to combat the accumulation of latent energy (the Vigner energy), compensation of graphite dimensional changes, lowering gas leakages in gas-cooled reactors and preventing graphite structure oxidation. The data given on radiation-induced dimensional changes and stress states of the structures at temperatures up to 800 deg C testify to great potential possibilities of graphite application in reactor cores

  7. Unemployment - Structural

    OpenAIRE

    Lindbeck, Assar

    1999-01-01

    Structural unemployment differs from cyclical unemployment by not disappearing in cyclical booms. In economic theory, structural unemployment is usually analysed in terms of the concept of equilibrium unemployment (the "natural unemployment rate" in Friedman’s terminology). Two elaborate concepts of equilibrium unemployment – the non-accelerating inflation rate of unemployment (the NAIRU) and the unemployment rate that induces firms and workers to accept the same real wage (the PS-WS-model) a...

  8. Structural Unemployment

    OpenAIRE

    Herz, Benedikt; van Rens, Thijs

    2011-01-01

    There is an ongoing debate on whether the recent surge in unemployment in the US is due to cyclical or structural factors. The distinction is important because the policies required to reduce each type of unemployment are very dierent. We use a novel approach to empirically quantify the extent of structural unemployment and to shed light on its sources. We propose a simple model of a segmented labor market. Within each segment, search frictions generate unemployment. In addition, there is str...

  9. Nuclear structure

    International Nuclear Information System (INIS)

    The paper on 'nuclear structure' is the Appendix to the Daresbury (United Kingdom) Annual Report 1985/86, and contains the research work carried out at the Nuclear Structure Facility, Daresbury, within that period. During the year a total of 74 experiments were scheduled covering the main areas of activity including: nuclear collective motion, nuclei far from stability, and nuclear collisions. The Appendix contains brief reports on these experiments and associated theory. (U.K.)

  10. Structural Dynamics

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.

    The present textbook has been written for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M.Sc. students in structural engineering.......The present textbook has been written for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M.Sc. students in structural engineering....

  11. Diverter structure

    International Nuclear Information System (INIS)

    The present invention concerns a vacuum vessel for a tokamak-type nuclear fusion plasma experimental device, and provides a divertor structure capable of reducing a distance of a plasma facing surface of a divertor structure and an inner wall of the vacuum vessel while maintaining cooling and heat removing performance. Namely, in the divertor structure of the present invention, a compulsory cooling channel on the side receiving high temperature load is made of a highly heat conductive material such as copper. The compulsory cooling channel on the side secured to a substrate is made of a material having high mechanical strength, for example, stainless steel. With such a constitution, the compulsory cooling channel on the side receiving high temperature load transfers the heat received by an armour material from plasmas efficiently to coolants. The opposite side can be secured to the inner wall of the vacuum vessel with satisfactory mechanical strength without interposing other additional materials. As a result, the structure of the present invention can reduce the distance of the plasma facing surface of the divertor structure and the inner wall of the vacuum vessel while maintaining the cooling and heat removing performance. (I.S.)

  12. Data Structures

    DEFF Research Database (Denmark)

    Davoodi, Pooya

    -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......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...

  13. Structural biophysics

    International Nuclear Information System (INIS)

    Summaries of research projects conducted during 1978 and 1979 are presented. The structural biophysics group explores the high-resolution structure of biological macromolecules and cell organelles. Specific subject areas include: the basic characteristics of photosynthesis in plants; the chemical composition of individual fly ash particles at the site of their damaging action in tissues; direct analysis of frozen-hydrated biological samples by scanning electron microscopy; yeast genetics; the optical activity of DNA aggregates; measurement and characterization of lipoproteins; function of lipoproteins; and the effect of radiation and pollutants on mammalian cells

  14. Foundation Structure

    DEFF Research Database (Denmark)

    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 the skirts of the bucket. The bucket size is used to simulate load situations and penetration into foundation...

  15. Ultrabornological structures

    Directory of Open Access Journals (Sweden)

    V. Murali

    1991-12-01

    Full Text Available The purpose of this note is to extend Warner's idea of “bornological structures“ to cover non-locally convex situations and to develop a framework unifying several variations on an ultrabornological theme (for example, ultrabornological spaces, o-ultrabornological spaces, i-ultrabornological algebras. We do this by first generalising the concept of a “structure” on a vector space as defined by Warner.

  16. 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.

  17. DNA structure

    OpenAIRE

    Bowater, R

    2003-01-01

    Deoxyribonucleic acid (DNA) is a polymer of nucleotides. In the cell, DNA usually adopts a double-stranded helical form, with complementary base-pairing holding the two strands together. The most stable conformation is called B-form DNA, although other structures can occur under specific conditions.

  18. Nanocrystal structures

    Science.gov (United States)

    Eisler, Hans J.; Sundar, Vikram C.; Walsh, Michael E.; Klimov, Victor I.; Bawendi, Moungi G.; Smith, Henry I.

    2006-12-19

    A structure including a grating and a semiconductor nanocrystal layer on the grating, can be a laser. The semiconductor nanocrystal layer can include a plurality of semiconductor nanocrystals including a Group II–VI compound, the nanocrystals being distributed in a metal oxide matrix. The grating can have a periodicity from 200 nm to 500 nm.

  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. 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…

  1. 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

  2. Nuclear structure

    International Nuclear Information System (INIS)

    The appendix to the Daresbury Annual report contains detailed summaries of experiments carried out, or in progress, for the period 1983/84, using the Nuclear Structure Facility tandem accelerator. The experimental work is carried out by University groups from the UK and abroad, and Daresbury Staff. Developments in instrumentation, and a report on the first year of scheduled operation of the Facility, are also given. (U.K.)

  3. Structural Homophily

    OpenAIRE

    Boucher, Vincent

    2012-01-01

    Homophily, or the fact that similar individuals tend to interact with each other, is a prominent feature of economic and social networks. Most existing theories of homophily are based on a descriptive approach and abstract away from equilibrium considerations. I show that the equilibrium structure of homophily has empirical power, as it can be used to recover underlying preference parameters. I build a non-cooperative model of network formation, which produces a unique, empirically realistic ...

  4. Photon Structure

    OpenAIRE

    Grindhammer, Guenter

    2001-01-01

    Large pT processes at HERA, initiated by almost real and by virtual photons, provide information on the structure of the photon. We report on the latest measurements of dijets and large pT particle production with the H1 detector. This includes a leading order determination of an effective virtual photon parton density, of the gluon density of the photon, and comparisons with models.

  5. 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.

  6. Airfoil structure

    Science.gov (United States)

    Frey, Gary A.; Twardochleb, Christopher Z.

    1998-01-01

    Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally "C" configuration of the airfoil. The generally "C" configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion.

  7. Track structure

    International Nuclear Information System (INIS)

    We are developing a Monte Carlo code, MOCA13, to calculate ionization and energy imparted in submicron sites by MeV positive ions. This code draws on extensive data for electron production in ion-molecule collisions as the source term for energy degradation calculations. The systematics of molecular cross sections are being analyzed to provide information on how molecular structure affects energy deposition calculations. We are assessing the reliability of calculations that use gas-phase cross sections to determine energy transport in the condensed phase. To make this assessment, we are comparing calculated multicollision electron spectra with measurements of the corresponding electron spectra emitted from foil targets on proton impact

  8. Baryon structure

    International Nuclear Information System (INIS)

    A brief review on the theoretical and experimental situation of baryon spectroscopy is first given. Then, the radial structure of baryons, related to the ground state form factors and the baryonic compressibility, is discussed. An experiment has been performed at Saturne laboratory (France) in which for the first time a compression of the nucleon is observed, exciting the P11 (1440 MeV) resonance (Roper resonance) by α-particles. The analysis of the data indicates that this excitation covers a large fraction of the available monopole strength in the nucleon. The derived compressibility is discussed as well as the consequence for other fields, as nuclear medium effects on baryon properties, high density phenomena in nuclear collisions as well as colour transparency. In the last point the spin-flip structure of the P11 (1440 MeV) resonance is discussed. The possibility to determine isoscalar spin-flip strength by polarized deuteron scattering is contrasted with first preliminary results from photon-induced reactions studied at Mainz which indicate a non-negligible M1 excitation of the Roper resonance. (author) 10 figs., 31 refs

  9. Scintillator structure

    International Nuclear Information System (INIS)

    Scintillator structures are described in which the phosphor is embedded or suspended in an optically transparent matrix which is selected or adjusted to have an index of refraction which is approximately equal to that of the phosphor at the wavelength of the light emitted by the phosphor. The matrix may be glass, copoly 2-vinyl naphthalene/vinyl toluene or a liquid e.g. Br-naphthalene and optionally CH3I, the ratio of components being adjusted to give the desired refractive index. The polymer may be made in situ or a mixture of phosphor and polymer formed e.g. by freeze drying a solution and pulverizing, and then heating. Specified dyes may be used for converting the emitted light to other wavelengths. (author)

  10. Business Structures

    Directory of Open Access Journals (Sweden)

    J. Gilkey

    2013-06-01

    Full Text Available The newspaper industry has absorbed a tremendous financial impact during the last three years in revenues and bottom lines. As a whole, industry players were slow to react to ever-changing marketplace dynamics. Newspapers report on other companies and industries in their business pages every day. However, they failed to listen to and heed some of the advice and counsel they offered on those some pages. As they have to come to acknowledge the trend, it has triggered a re-evaluation of the company’s organizational structure on the revenue and expense sides of the equation. The change in revenue streams had become so extreme that many large newspaper groups have opted to file bankruptcy in order to continue operations while relieving themselves of crushing loan payments and obsolete labor agreements. The newspaper industry, as a whole, is a capital-intensive one, with heavy investment required for printing and equipment for compiling and collating revenue-rich inserts, along with fleets of delivery trucks and vans

  11. The Mechanosensory Lateral Line System Mediates Activation of Socially-Relevant Brain Regions during Territorial Interactions

    Science.gov (United States)

    Butler, Julie M.; Maruska, Karen P.

    2016-01-01

    Animals use multiple senses during social interactions and must integrate this information in the brain to make context-dependent behavioral decisions. For fishes, the largest group of vertebrates, the mechanosensory lateral line system provides crucial hydrodynamic information for survival behaviors, but little is known about its function in social communication. Our previous work using the African cichlid fish, Astatotilapia burtoni, provided the first empirical evidence that fish use their lateral line system to detect water movements from conspecifics for mutual assessment and behavioral choices. It is unknown, however, where this socially-relevant mechanosensory information is processed in the brain to elicit adaptive behavioral responses. To examine for the first time in any fish species which brain regions receive contextual mechanosensory information, we quantified expression of the immediate early gene cfos as a proxy for neural activation in sensory and socially-relevant brain nuclei from lateral line-intact and -ablated fish following territorial interactions. Our in situ hybridization results indicate that in addition to known lateral line processing regions, socially-relevant mechanosensory information is processed in the ATn (ventromedial hypothalamus homolog), Dl (putative hippocampus homolog), and Vs (putative medial extended amygdala homolog). In addition, we identified a functional network within the conserved social decision-making network (SDMN) whose co-activity corresponds with mutual assessment and behavioral choice. Lateral line-intact and –ablated fight winners had different patterns of co-activity of these function networks and group identity could be determined solely by activation patterns, indicating the importance of mechanoreception to co-activity of the SDMN. These data show for the first time that the mechanosensory lateral line system provides relevant information to conserved decision-making centers of the brain during

  12. The Mechanosensory Lateral Line System Mediates Activation of Socially-Relevant Brain Regions during Territorial Interactions.

    Science.gov (United States)

    Butler, Julie M; Maruska, Karen P

    2016-01-01

    Animals use multiple senses during social interactions and must integrate this information in the brain to make context-dependent behavioral decisions. For fishes, the largest group of vertebrates, the mechanosensory lateral line system provides crucial hydrodynamic information for survival behaviors, but little is known about its function in social communication. Our previous work using the African cichlid fish, Astatotilapia burtoni, provided the first empirical evidence that fish use their lateral line system to detect water movements from conspecifics for mutual assessment and behavioral choices. It is unknown, however, where this socially-relevant mechanosensory information is processed in the brain to elicit adaptive behavioral responses. To examine for the first time in any fish species which brain regions receive contextual mechanosensory information, we quantified expression of the immediate early gene cfos as a proxy for neural activation in sensory and socially-relevant brain nuclei from lateral line-intact and -ablated fish following territorial interactions. Our in situ hybridization results indicate that in addition to known lateral line processing regions, socially-relevant mechanosensory information is processed in the ATn (ventromedial hypothalamus homolog), Dl (putative hippocampus homolog), and Vs (putative medial extended amygdala homolog). In addition, we identified a functional network within the conserved social decision-making network (SDMN) whose co-activity corresponds with mutual assessment and behavioral choice. Lateral line-intact and -ablated fight winners had different patterns of co-activity of these function networks and group identity could be determined solely by activation patterns, indicating the importance of mechanoreception to co-activity of the SDMN. These data show for the first time that the mechanosensory lateral line system provides relevant information to conserved decision-making centers of the brain during territorial

  13. 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.

  14. Computational structural mechanics for engine structures

    Science.gov (United States)

    Chamis, Christos C.

    1989-01-01

    The computational structural mechanics (CSM) program at Lewis encompasses the formulation and solution of structural mechanics problems and the development of integrated software systems to computationally simulate the performance, durability, and life of engine structures. It is structured to supplement, complement, and, whenever possible, replace costly experimental efforts. Specific objectives are to investigate unique advantages of parallel and multiprocessing for reformulating and solving structural mechanics and formulating and solving multidisciplinary mechanics and to develop integrated structural system computational simulators for predicting structural performance, evaluating newly developed methods, and identifying and prioritizing improved or missing methods.

  15. 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 What is structural biology? Structural biology is a field of science focused ...

  16. Adaptive Space Structures

    Science.gov (United States)

    Wada, B.

    1993-01-01

    The term adaptive structures refers to a structural control approach in which sensors, actuators, electronics, materials, structures, structural concepts, and system-performance-validation strategies are integrated to achieve specific objectives.

  17. Fluid-structure interaction in composite structures

    OpenAIRE

    Plessas, Spyridon D.

    2014-01-01

    Approved for public release; distribution is unlimited. In this research, dynamic characteristics of polymer composite beam and plate structures were studied when the structures were in contact with water. The effect of fluid-structure interaction (FSI) on natural frequencies, mode shapes, and dynamic responses was examined for polymer composite structures using multiphysics-based computational techniques. Composite structures were modeled using the finite element method. The fluid was mod...

  18. Magnetic multilayer structure

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. 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....

  20. 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.

  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. Structural Health Monitoring of Large Structures

    Science.gov (United States)

    Kim, Hyoung M.; Bartkowicz, Theodore J.; Smith, Suzanne Weaver; Zimmerman, David C.

    1994-01-01

    This paper describes a damage detection and health monitoring method that was developed for large space structures using on-orbit modal identification. After evaluating several existing model refinement and model reduction/expansion techniques, a new approach was developed to identify the location and extent of structural damage with a limited number of measurements. A general area of structural damage is first identified and, subsequently, a specific damaged structural component is located. This approach takes advantage of two different model refinement methods (optimal-update and design sensitivity) and two different model size matching methods (model reduction and eigenvector expansion). Performance of the proposed damage detection approach was demonstrated with test data from two different laboratory truss structures. This space technology can also be applied to structural inspection of aircraft, offshore platforms, oil tankers, ridges, and buildings. In addition, its applications to model refinement will improve the design of structural systems such as automobiles and electronic packaging.

  3. On metallic Riemannian structures

    OpenAIRE

    Gezer, Aydin; KARAMAN, ÇAĞRI

    2015-01-01

    The paper is devoted to the study of metallic Riemannian structures. An integrability condition and curvature properties for these structures by means of a $\\Phi $-operator applied to pure tensor fields are presented. Examples of these structures are also given.

  4. Designing pliable structural Skins

    DEFF Research Database (Denmark)

    Tamke, Martin; Peters, Brady; Nielsen, Stig Anton; Andersen, Niels Jakubiak; Campbell, Reese; Stasiuk, David

    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.......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....

  5. 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

  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. 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...

  8. 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....

  9. 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/. PMID:18004784

  10. 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 on......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...... 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...

  11. Revisiting Pattern Structures for Structured Attribute Sets

    OpenAIRE

    Alam, Mehwish; Buzmakov, Aleksey; Napoli, Amedeo; Sailanbayev, Alibek

    2015-01-01

    In this paper, we revisit an original proposition on pattern structures for structured sets of attributes. There are several reasons for carrying out this kind of research work. The original proposition does not give many details on the whole framework, and especially on the possible ways of implementing the similarity operation. There exists an alternative definition without any reference to pattern structures, and we would like to make a parallel between two points of view. Moreover we disc...

  12. Aluminium structural elements

    OpenAIRE

    Švent, Nejc

    2016-01-01

    This thesis focuses on the structural analysis of aluminium structural members in accordance with the SIST EN 1999-1-1 standard. In the introduction, historical development of aluminium is summarized, as well as the processes of structural aluminium production and manufacture. Predominantly, resistance control checks of aluminium structural members are covered, with special attention to the major contrasts between aluminium and steel structural analyses. Finally, fundamental examples of resis...

  13. Expectations from structural genomics.

    OpenAIRE

    Brenner, S. E.; Levitt, M.

    2000-01-01

    Structural genomics projects aim to provide an experimental structure or a good model for every protein in all completed genomes. Most of the experimental work for these projects will be directed toward proteins whose fold cannot be readily recognized by simple sequence comparison with proteins of known structure. Based on the history of proteins classified in the SCOP structure database, we expect that only about a quarter of the early structural genomics targets will have a new fold. Among ...

  14. Intonation and information structure

    OpenAIRE

    Heusinger, Klaus von

    1999-01-01

    The concepts intonation and information structure refer to two components of grammar that are commonly assumed to be autonomous and independent of the canonical parts phonology, morphology, syntax and semantics. Both structures are closely related to each other: Intonational patterns express informational structuring, and a great part of the information structure is linguistically conveyed by intonation. Intonational patterns are not understood as a single structure, but as a complex of diffe...

  15. Teaching Structured Fortran without Structured Extensions.

    Science.gov (United States)

    Worland, Peter B.

    Six control structures are used in teaching a college Fortran programing course: (1) simple sequences of instruction without any control statement, (2) IF-THEN selection, (3) IF-THEN-ELSE selection, (4) definite loop, (5) indefinite loop, and (6) generalized IF-THEN-ELSE case structure. Outlines, instead of flowcharts, are employed for algorithm…

  16. 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

  17. 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.

  18. Inventories, financial structure and market structure.

    OpenAIRE

    Tribó, Josep A.

    2001-01-01

    In this paper, we study the effect of different financial contracts on the firm's inventory policy. Doing so will allow to define the best financial instruments to diminish the stock variability of a profit-maximizing firm in a given economic environment (expansion or recession), and for a given market structure. We show that in periods of recession (expansion), reducing (increasing) the amount of short-term debt is an optimal strategy independently of the market structure.

  19. Space Structure Development

    Science.gov (United States)

    Smith, Thomas

    2015-01-01

    The duration of my Summer 2015 Internship Tour at NASA's Johnson Space Center was spent working in the Structural Engineering Division's Structures Branch. One of the two main roles of the Structures Branch, ES2, is to ensure the structural integrity of spacecraft vehicles and the structural subsystems needed to support those vehicles. The other main objective of this branch is to develop the lightweight structures that are necessary to take humans beyond Low-Earth Orbit. Within ES2, my four projects involved inflatable space structure air bladder material testing; thermal and impact material testing for spacecraft windows; structural analysis on a joint used in the Boeing CST-100 airbag system; and an additive manufacturing design project.

  20. 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...

  1. 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 and...... four separate studies. In the first study, we propose a simple framework that may be used as a base when studying the link between social structure and fitness. We furthermore review current evidence for fitness effects of social structure, and find good support for such effects. In the second study...... evolution of behaviour, and for individual fitness. In this thesis I investigated implications of social structure for fitness and behaviour, with focus on three main areas: social structure & fitness, social structure & communication, and social structure & cooperation. These areas were investigated in...

  2. 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...

  3. The life of structures

    International Nuclear Information System (INIS)

    This book provides an examination of design for durability in the built environment. The basic principles of design and assessment; materials and test methods; nuclear and special structures; and the performance of populations of structures are among specific topics addresses

  4. 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.

  5. Robustness of Structures

    DEFF Research Database (Denmark)

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

    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...

  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. Revisiting Pattern Structure Projections

    OpenAIRE

    Buzmakov, Aleksey; Kuznetsov, Sergei O.; Napoli, Amedeo

    2015-01-01

    Formal concept analysis (FCA) is a well-founded method for data analysis and has many applications in data mining. Pattern structures is an extension of FCA for dealing with complex data such as sequences or graphs. However the computational complexity of computing with pattern structures is high and projections of pattern structures were introduced for simplifying computation. In this paper we introduce o-projections of pattern structures, a generalization of projections which defines a wide...

  8. 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

  9. Observables on Quantum Structures

    OpenAIRE

    Dvurečenskij, Anatolij; Kuková, Mária

    2012-01-01

    An observable on a quantum structure is any $\\sigma$-homomorphism of quantum structures from the Borel $\\sigma$-algebra into the quantum structure. We show that our partial information on an observable known only for all intervals of the form $(-\\infty,t)$ is sufficient to determine uniquely the whole observable defined on quantum structures like $\\sigma$-MV-algebras, $\\sigma$-effect algebras, Boolean $\\sigma$-algebras, monotone $\\sigma$-complete effect algebras with the Riesz Decomposition P...

  10. Regenerative partition structures

    OpenAIRE

    Gnedin, Alexander; Pitman, Jim

    2004-01-01

    We consider Kingman's partition structures which are regenerative with respect to a general operation of random deletion of some part. Prototypes of this class are the Ewens partition structures which Kingman characterised by regeneration after deletion of a part chosen by size-biased sampling. We associate each regenerative partition structure with a corresponding regenerative composition structure, which (as we showed in a previous paper) can be associated in turn with a regenerative random...

  11. Structure sensitivity in adsorption

    DEFF Research Database (Denmark)

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

    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...... structure to the next. We propose a model to explain this behavior, and use it to discuss more generally the origin of structure sensitivity in heterogeneous catalysis....

  12. Networks and Industry Structure

    OpenAIRE

    Johnson, F P

    1995-01-01

    This paper explores how the network approach to marketing might be informed by concepts drawn from traditional industry structure analysis. It argues that industry structures defined by small numbers of participants such as oligopolies are more likely to lead to network effects while industry structures that approach perfect competition are unlikely to involve network formation.

  13. Structural patterns in nature

    DEFF Research Database (Denmark)

    Wester, Ture

    2004-01-01

    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 be an...

  14. 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 d

  15. Catalytic distillation structure

    Science.gov (United States)

    Smith, Jr., Lawrence A.

    1984-01-01

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

  16. Structures in sculptures

    DEFF Research Database (Denmark)

    Vanggaard, Ole

    the different concepts and find a final synthesis, but the problem is known. Large sculptures represent structural challenges. The design of the supports inside the structures reveals often a very different world from the outside view of the sculpture. The piece of art and its structure may have two very......Conceptual design of structures in architecture involves a dialog between a structural and an architectural concept. The architecture is very often changed in this process. The dialog between the parties are described and well known. It is often very difficult to bridge the gab between...... and the artists concept interacts....

  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. 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

  19. Robustness of structures

    DEFF Research Database (Denmark)

    Vrouwenvelder, T.; Sørensen, John Dalsgaard

    After the collapse of the World Trade Centre towers in 2001 and a number of collapses of structural systems in the beginning of the century, robustness of structural systems has gained renewed interest. Despite many significant theoretical, methodical and technological advances, structural...... 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 of...... robustness for structural design such requirements are not substantiated in more detail, nor have the engineering profession been able to agree on an interpretation of robustness which facilitates for its uantification. A European COST action TU 601 on ‘Robustness of structures' has started in 2007 by a...

  20. Computers boost structural technology

    Science.gov (United States)

    Noor, Ahmed K.; Venneri, Samuel L.

    1989-01-01

    Derived from matrix methods of structural analysis and finite element methods developed over the last three decades, computational structures technology (CST) blends computer science, numerical analysis, and approximation theory into structural analysis and synthesis. Recent significant advances in CST include stochastic-based modeling, strategies for performing large-scale structural calculations on new computing systems, and the integration of CST with other disciplinary modules for multidisciplinary analysis and design. New methodologies have been developed at NASA for integrated fluid-thermal structural analysis and integrated aerodynamic-structure-control design. The need for multiple views of data for different modules also led to the development of a number of sophisticated data-base management systems. For CST to play a role in the future development of structures technology and in the multidisciplinary design of future flight vehicles, major advances and computational tools are needed in a number of key areas.

  1. BIALGEBRAIC STRUCTURES AND SMARANDACHE BIALGEBRAIC STRUCTURES

    OpenAIRE

    Vasantha, Kandasamy

    2003-01-01

    The study of bialgebraic structures started very recently. Till date there are no books solely dealing with bistructures. The study of bigroups was carried out in 1994-1996. Further research on bigroups and fuzzy bigroups was published in 1998. In the year 1999, bivector spaces was introduced. In 2001, concept of free De Morgan bisemigroups and bisemilattices was studied. It is said by Zoltan Esik that these bialgebraic structures like bigroupoids, bisemigroups, binea...

  2. 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.......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...

  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. Control of flexible structures

    Science.gov (United States)

    Russell, R. A.

    1985-01-01

    The requirements for future space missions indicate that many of these spacecraft will be large, flexible, and in some applications, require precision geometries. A technology program that addresses the issues associated with the structure/control interactions for these classes of spacecraft is discussed. The goal of the NASA control of flexible structures technology program is to generate a technology data base that will provide the designer with options and approaches to achieve spacecraft performance such as maintaining geometry and/or suppressing undesired spacecraft dynamics. This technology program will define the appropriate combination of analysis, ground testing, and flight testing required to validate the structural/controls analysis and design tools. This work was motivated by a recognition that large minimum weight space structures will be required for many future missions. The tools necessary to support such design included: (1) improved structural analysis; (2) modern control theory; (3) advanced modeling techniques; (4) system identification; and (5) the integration of structures and controls.

  5. Structure study with AMD

    International Nuclear Information System (INIS)

    Structure study by the use of AMD in stable and unstable nuclei is reviewed. We put some emphasis on the characteristic features of AMD approach which include variation after parity projection, variation after angular momentum projection, superposition of parity-spin projected AMD Slater determinants. Since AMD is an ab initio theory of nuclear structure, we can study cluster structure without assuming the existence of any clusters and can describe the coexistence of meanfield-type structure and cluster structure. Some examples of calculated results are shown by comparing with the experimental data. They are the studies on neutron-rich Li, BeCB isotopes, on the island of inversion around N=20, and on the excited bands with many-particle many-hole structure in 44Ti. (author)

  6. Structure-factor probabilities for related structures

    International Nuclear Information System (INIS)

    Probability relationships between structure factors from related structures have allowed previously only for either differences in atomic scattering factors (isomorphous replacement case) or differences in atomic positions (coordinate error case). In the coordinate error case, only errors drawn from a single probability distribution have been considered, in spite of the fact that errors vary widely through models of macromolecular structures. It is shown that the probability relationships can be extended to cover more general cases. Either the atomic parameters or the reciprocal-space vectors may be chosen as the random variables to derive probability relationships. However, the relationships turn out to be very similar for either choice. The most intuitive is the expected electron-density formalism, which arises from considering the atomic parameters as random variables. In this case, the centroid of the structure-factor distribution is the Fourier transform of the expected electron-density function, which is obtained by smearing each atom over its possible positions. The centroid estimate has a phase different from, and more accurate than, that obtained from the unweighted atoms. The assumption that there is a sufficient number of independent errors allows the application of the central limit theorem. This gives a one- (centric case) or two-dimensional (non-centric) Gaussian distribution about the centroid estimate. The general probability expression reduces to those derived previously when the appropriate simplifying assumptions are made. The revised theory has implications for calculating more accurate phases and maps, optimizing molecular replacement models, refining structures, estimating coordinate errors and interpreting refined B factors. (orig.)

  7. Nonlinear structure tensors

    OpenAIRE

    Brox, Thomas; Weickert, Joachim; Burgeth, Bernhard; Mrázek, Pavel

    2004-01-01

    In this article we introduce nonlinear versions of the popular structure tensor, also known as second moment matrix. These nonlinear structure tensors replace the Gaussian smoothing of the classical structure tensor by discontinuity-preserving nonlinear diffusions. While nonlinear diffusion is a well-established tool for scalar and vector-valued data, it has not often been used for tensor images so far. Two types of nonlinear diffusion processes for tensor data are studied: an isotropic one w...

  8. 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'.

  9. Harmonic almost contact structures

    OpenAIRE

    Vergara-Diaz, E.; Wood, C. M.

    2006-01-01

    An almost contact metric structure is parametrized by a section of an associated homogeneous fibre bundle, and conditions for this to be a harmonic section, and a harmonic map, are studied. These involve the characteristic vector field, and the almost complex structure in the contact subbundle. Several examples are given where the harmonic section equations reduce to those for the characteristic field to be a harmonic section of the unit tangent bundle. These include trans-Sasakian structures...

  10. CSR : Structure for Responsibility

    OpenAIRE

    Adestam, Carina; Gunnmo, Sofia

    2008-01-01

    Many organisational flaws are consequences of unsuitable structure arrangements that do not support the organisation in its work towards goal accomplishment. The appropriateness of the structure is determined by how well it allows the organisation to respond to the environment in which it is active. Furthermore, an organisation is divided into parts with their own requirements on the structure. CSR is a concept that enables for a wider perspective of how to conduct business, thereby strengthe...

  11. Civil Servants’ Salary Structure

    OpenAIRE

    Bilquees, Faiz

    2006-01-01

    The paper looks at the trends in nominal and real salaries of the Federal Government employees over the period 1990-2006. It examines the structural defects in the existing salary structure and the anomalies in the allowances structure to show that appropriate remuneration for the civil servants requires serious and urgent consideration. The widening gap in the emoluments of government employees versus the public sector corporations and private sector employees has a strong bearing on the mot...

  12. 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.

  13. Structural Unemployment in Finland

    OpenAIRE

    Pasi Holm; Elina Somervuori

    1997-01-01

    Since the Finnish unemployment rate has rocketed to a very high level in the beginning of the 1990?s it is worth to study to what extent the unemployment rate prevailing today is due to cyclical or to structural reasons. In this paper we try to estimate two different indicators that represent the structural part of unemployment, the NAWRU and the NAIRU. The NAWRU (non-accelerating wage rate of unemployment) measures the structural unemployment simply by relating unemployment to wage inflation...

  14. Irreducibility in RNA structures

    OpenAIRE

    Jin, Emma Y.; Reidys, Christian M.

    2009-01-01

    In this paper we study irreducibility in RNA structures. By RNA structure we mean RNA secondary as well as RNA pseudoknot structures. In our analysis we shall contrast random and minimum free energy (mfe) configurations. We compute various distributions: of the numbers of irreducible substructures, their locations and sizes, parameterized in terms of the maximal number of mutually crossing arcs, $k-1$, and the minimal size of stacks $\\sigma$. In particular, we analyze the size of the largest ...

  15. Halos and related structures

    DEFF Research Database (Denmark)

    Riisager, Karsten

    The halo structure originated from nuclear physics but is now encountered more widely. It appears in loosely bound, clustered systems where the spatial extension of the system is significantly larger than that of the binding potentials. A review is given on our current understanding of these...... structures, with an emphasis on how the structures evolve as more cluster components are added and on the experimental situation concerning halo states in light nuclei....

  16. New structures for physics

    Energy Technology Data Exchange (ETDEWEB)

    Coecke, Bob (ed.)

    2011-07-01

    This volume provides a series of tutorials on mathematical structures which recently have gained prominence in physics, ranging from quantum foundations, via quantum information, to quantum gravity. These include the theory of monoidal categories and corresponding graphical calculi, Girard's linear logic, Scott domains, lambda calculus and corresponding logics for typing, topos theory, and more general process structures. Most of these structures are very prominent in computer science; the chapters here are tailored towards an audience of physicists. (orig.)

  17. COLLAGEN STRUCTURE AND STABILITY

    OpenAIRE

    Shoulders, Matthew D.; Raines, Ronald T.

    2009-01-01

    Collagen is the most abundant protein in animals. This fibrous, structural protein comprises a right-handed bundle of three parallel, left-handed polyproline II-type helices. Much progress has been made in elucidating the structure of collagen triple helices and the physicochemical basis for their stability. New evidence demonstrates that stereoelectronic effects and preorganization play a key role in that stability. The fibrillar structure of type I collagen–the prototypical collagen fibril–...

  18. Quantum inferring acausal structure

    OpenAIRE

    Glos, Adam; Kurzyk, Dariusz

    2015-01-01

    This paper presents a generalization of probability theory and inferring structures in a field of quantum information theory. First, the formalism of quantum information theory is introduced. Next, quantum theory is used to define a quantum conditional operators which are fundamental in describing quantum inferring structures. The result of reasoning performance over the structures was presented in a Monty Hall game. The experiment shows that entanglement of quantum states has influence on op...

  19. Component nuclear containment structure

    International Nuclear Information System (INIS)

    The invention described is intended for use primarily as a nuclear containment structure. Such structures are required to surround the nuclear steam supply system and to contain the effects of breaks in the nuclear steam supply system, or i.e. loss of coolant accidents. Nuclear containment structures are required to withstand internal pressure and temperatures which result from loss of coolant accidents, and to provide for radiation shielding during operation and during the loss of coolant accident, as well as to resist all other applied loads, such as earthquakes. The nuclear containment structure described herein is a composite nuclear containment structure, and is one which structurally combines two previous systems; namely, a steel vessel, and a lined concrete structure. The steel vessel provides strength to resist internal pressure and accommodate temperature increases, the lined concrete structure provides resistance to internal pressure by having a liner which will prevent leakage, and which is in contact with the concrete structure which provides the strength to resist the pressure

  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. Antenna Structure Registration (ASR)

    Data.gov (United States)

    Federal Communications Commission — As part of its ongoing efforts to promote air safety, the Federal Communications Commission requires owners to register certain antenna structures (generally those...

  2. 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

  3. Deployable Soft Composite Structures.

    Science.gov (United States)

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

    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 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. PMID:26892762

  4. 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

  5. Mitotic chromosome structure

    International Nuclear Information System (INIS)

    Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

  6. Dirac structures on protobialgebroids

    Institute of Scientific and Technical Information of China (English)

    YIN; Yanbin; HE; Longguang

    2006-01-01

    Protobialgebroids include several kinds of algebroid structures such as Lie algebroid,Lie bialgebroid, Lie quasi-bialgebroid, etc. In this paper, the Dirac theories are generalized from Lie bialgebroid to protobialgebroid. We give the integrable conditions for a maximally isotropic subbundle being a Dirac structure for a protobialgebroid by the notion of a characteristic pair. From the integrable conditions, we found out that the Dirac structure has closed relations with the twisting of a protobialgebroid. At last, some special cases of the Dirac structures for protobialgebroids are discussed.

  7. 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

  8. 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...... background material. It derives the theoretical background of wind loaded structures and gives practical applications for a large variety of structures, such as low rise static structures, buildings, chimneys and cable-supported bridges. The European Prestandard on Wind Actions, ENV 1991-2-4, is used...

  9. Structural building response review

    International Nuclear Information System (INIS)

    The integrity of a nuclear power plant during a postulated seismic event is required to protect the public against radiation. Therefore, a detailed set of seismic analyses of various structures and equipment is performed while designing a nuclear power plant. This report describes the structural response analysis method, including the structural model, soil-structure interaction as it relates to structural models, methods for seismic structural analysis, numerical integration methods, methods for non-seismic response analysis approaches for various response combinations, structural damping values, nonlinear response, uncertainties in structural properties, and structural response analysis using random properties. The report describes the state-of-the-art in these areas for nuclear power plants. It also details the past studies made at Sargent and Lundy to evaluate different alternatives and the conclusions reached for the specific purposes that those studies were intended. These results were incorporated here because they fall into the general scope of this report. The scope of the present task does not include performing new calculations

  10. Structure of human adenovirus

    Energy Technology Data Exchange (ETDEWEB)

    Nemerow, Glen R.; Stewart, Phoebe L.; Reddy, Vijay S. (Scripps); (Vanderbilt)

    2012-07-11

    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 {angstrom} resolution. The virus structure revealed the location, folds, and interactions of major and minor (cement proteins) on the inner and outer capsid surface. This new structural information sheds further light on the process of adenovirus capsid assembly and virus-host cell interactions.

  11. Structure of hadrons. Proceedings

    International Nuclear Information System (INIS)

    The following topics were dealt with: Hadronic reactions and resonances, structure of mesons, baryons, glueballs, and hybrids, physics with strange and charmed quarks, future projects and facilities. (HSI)

  12. Observables on Quantum Structures

    CERN Document Server

    Dvurečenskij, Anatolij

    2012-01-01

    An observable on a quantum structure is any $\\sigma$-homomorphism of quantum structures from the Borel $\\sigma$-algebra into the quantum structure. We show that our partial information on an observable known only for all intervals of the form $(-\\infty,t)$ is sufficient to determine uniquely the whole observable defined on quantum structures like $\\sigma$-MV-algebras, $\\sigma$-effect algebras, Boolean $\\sigma$-algebras, monotone $\\sigma$-complete effect algebras with the Riesz Decomposition Property, the effect algebra of effect operators of a Hilbert space, and a system of functions, and an effect-tribe.

  13. 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

  14. 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.......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....

  15. Structuring of Forest Communities

    Directory of Open Access Journals (Sweden)

    S. K. Farber

    2014-02-01

    Full Text Available Structuring forest communities is considered as a pre-studying procedure. The paper defines the fundamental structuring terms and describes the theory behind it. Factors hampering forest typology development are discussed. The areas of forest typology promising regarding sustainable and multi-purposed forest management are outlined.

  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 pr

  17. Deformation of coherent structures

    NARCIS (Netherlands)

    Fledderus, E.R.; Groesen, van E.

    1996-01-01

    In this review we investigate the mathematical description of the distortion of clearly recognisable structures in phenomenological physics. The coherent structures we will explicitly deal with are surface waves on a layer of fluid, kink transitions in magnetic material, plane vortices, swirling flo

  18. Stable Umbral Chromospheric Structures

    CERN Document Server

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

    2014-01-01

    Aims. 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 was 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 minutes. 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 ...

  19. 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.

  20. Low-beta structures

    OpenAIRE

    M. Vretenar(CERN, Geneva, Switzerland)

    2012-01-01

    'Low-beta' radio-frequency accelerating structures are used in the sections of a linear accelerator where the velocity of the particle beam increases with energy. The requirement for space periodicity to match the increasing particle velocity led to the development of a large variety of structures, both normal and superconducting, which are described in this lecture.

  1. 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 ...

  2. 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…

  3. 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....

  4. Methods for structural control

    OpenAIRE

    Baratta, A.; Bourquin, F.; CORBI, O; HOCHRAINER, M; Luo, N; MAGONETTE, G; Marazzi, F; Rodellar, J.

    2004-01-01

    In the last decades significant advances have been produced in the field of structural control. This paper focuses on some issues related with the problem of controlling (reducing) undesired vibrations, summarizing the experiences of the authors in some specific issues on specific classes of structural control systems.

  5. Robust Adaptive Structural Control

    OpenAIRE

    Yang, Chi-Ming; Beck, James L.

    1995-01-01

    A new robust adaptive structural control design methodology is developed and presented which treats modeling uncertainties and limitations of control devices. Furthermore, no restriction is imposed on the structural models and the nature of the control devices so that the proposed method is very general. A simple linear single degree-of-freedom numerical example is presented to illustrate this approach.

  6. 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.

  7. Mechanics of composite structures

    CERN Document Server

    Kollár, László P

    2003-01-01

    An increase in the use of composite materials has led to a greater demand for engineers versed in the design of structures made from such materials. This book demonstrates advanced concepts and emphasizes structures. More than 300 illustrations, 50 fully worked problems, and material properties data sets are included

  8. 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...

  9. Structural patterns in nature

    DEFF Research Database (Denmark)

    Wester, Ture

    2003-01-01

    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 be an...

  10. 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.

  11. Wave scour around structures

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Fredsøe, Jørgen

    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...

  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 par

  13. 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.

  14. 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.

  15. Safety of Marine Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.

    1990-01-01

    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...

  16. 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 o...

  17. 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...

  18. Structure and Function

    CERN Document Server

    Comba, Peter

    2010-01-01

    Describes how the understanding of structure - property relationships may be used to interpret known compounds and how to design novel molecules and materials with the desired properties. This book covers the theoretical background, experimental techniques and applications of structure-property correlations

  19. 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…

  20. Frontiers of Nuclear Structure

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, Witold

    1997-12-31

    Current developments in nuclear structure at the `limits` are discussed. The studies of nuclear behavior at extreme conditions provide us with invaluable information about the nature of the nuclear interaction and nucleonic correlations at various energy-distance scales. In this talk frontiers of nuclear structure are briefly reviewed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei.

  1. Development of CFTR structure

    Directory of Open Access Journals (Sweden)

    AnnaEPatrick

    2012-09-01

    Full Text Available Cystic fibrosis is a lethal genetic disease caused by lack of functional cystic fibrosis transmembrane conductance regulator (CFTR proteins at the apical surface of secretory epithelia. CFTR is a multidomain protein, containing five domains, and its functional structure is attained in a hierarchical folding process. Most CF-causing mutations in CFTR, including the most common mutation, a deletion of phenylalanine at position 508 (ΔF508, are unable to properly fold into this functional native three dimensional structure. Currently, no high resolution structural information about full length CFTR exists. However, insight has been gained through examining homologous ABC transporter structures, molecular modeling, and high resolution structures of individual, isolated CFTR domains. Taken together, these studies indicate that the prevalent ΔF508 mutation disrupts two essential steps during the development of the native structure: folding of the first nucleotide binding domain (NBD1 and its later association with the fourth intracellular loop (ICL4 in the second transmembrane domain (TMD2. Therapeutics to rescue ΔF508 and other mutants in CFTR can be targeted to correct defects that occur during the complex folding process. This article reviews the structural relationships between CFTR and ABC transporters and current knowledge about how CFTR attains its structure--with a focus on how this process is altered by CF-causing mutations in a manner targetable by therapeutics.

  2. Incommensurability in crystal structures

    International Nuclear Information System (INIS)

    Incommensurate or modulated crystal structures (TaS2, Srsub(1-p)Cr2Sesub(4-p), etc.) are examined and compared with superstructures (TaSe2, Basub(1-p)Cr2Sesub(4-p)). Observed and calculated structure factors are given for Eusub(1-p)Cr2Sesub(4-p). (C.F.)

  3. Reliability of nuclear structures

    International Nuclear Information System (INIS)

    The reliability analysis of structural components as contributing factor to risk analyses of nuclear power plants is presented. In this context probabilistic models for the occurrence and effects of potential external loading conditions (i.e. earthquake and aircraft impact) are developed and utilized within a reliability concept. The concept is exemplified by applying to a containment structure

  4. 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…

  5. 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...

  6. Languages for structural calculations

    International Nuclear Information System (INIS)

    The differences between human and computing languages are recalled. It is argued that they are to some extent structured in antagonistic ways. Languages in structural calculation, in the past, present, and future, are considered. The contribution of artificial intelligence is stressed

  7. 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. PMID:27048719

  8. Structure correlation and chemistry

    International Nuclear Information System (INIS)

    The main goal of crystal and molecular structure determination is to provide a starting point for understanding the physical, chemical and biological properties of matter. At present, results from nearly 300000 crystal structure studies are available in computer-readable form. Structure correlation attempts to extract knowledge and understanding from this body of information, which is not available from its parts. This article reviews some typical examples: libraries of prototypal molecular dimensions, mappings of chemical reaction pathways, correlations between structure on one hand and energy, reaction rate, catalytic activity or magnetism on the other. The knowledge gained from structure-correlation studies, together with quantum-chemical and other modeling techniques, provides conceptual and practical tools for designing molecules and materials with tailor-made properties. (orig.)

  9. 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.  

  10. 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. PMID:25092669

  11. Structural dynamics in FBR

    International Nuclear Information System (INIS)

    In view of thin walled large diameter shell structures with associated fluid effects, structural dynamics problems are very critical in a fast breeder reactor. Structural characteristics and consequent structural dynamics problems in typical pool type Fast Breeder Reactor are highlighted. A few important structural dynamics problems are pump induced as well as flow induced vibrations, seismic excitations, pressure transients in the intermediate heat exchangers and pipings due to a large sodium water reaction in the steam generator, and core disruptive accident loadings. The vibration problems which call for identification of excitation forces, formulation of special governing equations and detailed analysis with fluid structure interaction and sloshing effects, particularly for the components such as PSP, inner vessel, CP, CSRDM and TB are elaborated. Seismic design issues are presented in a comprehensive way. Other transient loadings which are specific to FBR, resulting from sodium-water reaction and core disruptive accident are highlighted. A few important results of theoretical as well as experimental works carried out for 500 MWe Prototype Fast Breeder Reactor (PFBR), in the domain of structural dynamics are presented. (author)

  12. 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.

  13. 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

  14. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    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 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 of the...

  15. Structure-mediated nanoscopy

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...... structures with built-in waveguides for us, we were able to put the idea of optically steerable freestanding waveguides – coined: wave-guided optical waveguides - to the test using our BioPhotonics Workstation [7]. We also proposed designing micro-structures for so-called structure-mediated access to the...

  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. Product Structuring, an overview

    DEFF Research Database (Denmark)

    Tichem, Marcel; Storm, Ton; Andreasen, Mogens Myrup; MacCallum, Ken J.

    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.......In the paper, the field of product structuring is defined and broken down into topics. For each of the topics, results of research are presented. Issues for further research are identified. The references in the paper refer to papers in the proceedings of the workshops....

  18. Structural Acoustics and Vibrations

    Science.gov (United States)

    Chaigne, Antoine

    This structural chapter is devoted to vibrations of structures and to their coupling with the acoustic field. Depending on the context, the radiated sound can be judged as desirable, as is mostly the case for musical instruments, or undesirable, like noise generated by machinery. In architectural acoustics, one main goal is to limit the transmission of sound through walls. In the automobile industry, the engineers have to control the noise generated inside and outside the passenger compartment. This can be achieved by means of passive or active damping. In general, there is a strong need for quieter products and better sound quality generated by the structures in our daily environment.

  19. Thinning Invariant Partition Structures

    CERN Document Server

    Starr, Shannon

    2011-01-01

    A partition structure is a random point process on $[0,1]$ whose points sum to 1, almost surely. In the case that there are infinitely many points to begin with, we consider a thinning action by: first, removing points independently, such that each point survives with probability $p>0$; and, secondly, rescaling the remaining points by an overall factor to normalize the sum again to 1. We prove that the partition structures which are "thinning divisible" for a sequence of $p$'s converging to 0 are mixtures of the Poisson-Kingman partition structures. We also consider the property of being "thinning invariant" for all $p \\in (0,1)$.

  20. Nuclear reactor internal structures

    International Nuclear Information System (INIS)

    The upper internal structures of the reactor are connected to the closing head so as to be readily removed with the latter and a skirt connected to the lower portion of said upper structures so as to surround the latter, extends under the control rods when they are removed from the reactor core. Through such an arrangement the skirt protects the control rods and supports the vessel closing-head and the core upper structures, whenever the head is severed from the vessel and put beside the latter in order to discharge the reactor

  1. 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.

  2. 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...

  3. Stratigraphy and structural geology

    Science.gov (United States)

    Carr, M. H.; Wilhelms, D. E.; Greeley, R.; Guest, J. E.

    1976-01-01

    The immediate goal of stratigraphy and structural geology is to reduce the enormous complexity of a planetary surface to comprehensible proportions by dividing the near-surface rocks into units and mapping their distribution and attitude.

  4. 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.

  5. A Structure for Quasars

    CERN Document Server

    Elvis, Martin

    2009-01-01

    This paper proposes a simple, empirically derived, unifying structure for the inner regions of quasars. This structure is constructed to explain the broad absorption line (BAL) regions, the narrow `associated' ultraviolet and X-ray warm absorbers (NALs); and is also found to explain the broad emission line regions (BELR), and several scattering features, including a substantial fraction of the broad X-ray Iron-K emission line, and the bi-conical extended narrow emission line region (ENLR) structures seen on large kiloparsec scales in Seyfert images. Small extensions of the model to allow luminosity dependent changes in the structure may explain the UV and X-ray Baldwin effects and the greater prevalence of obscuration in low luminosity AGN.

  6. 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...

  7. Robustness of Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    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...... 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...... ways and on different levels of complexity / applicability. On the most general level robustness is assessed taking basis in decision analysis theory by estimating both direct risk, which is associated with the direct consequences of potential damages to the structure, and indirect risk, which...

  8. Robustness of Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    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....... 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 of the...

  9. 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...

  10. Structuring the Curriculum

    Directory of Open Access Journals (Sweden)

    Petrová Gabriela

    2016-06-01

    Full Text Available In the proposed paper, we deal with the opportunities of structuring the curriculum. On the theoretical level, we discuss the content of education, the process of knowledge selection and organization, suggestions for increasing the quality of textbooks.

  11. 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. PMID:22233136

  12. 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...

  13. 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.

  14. 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 ...

  15. NETWORKING ENTERPRISE MANAGEMENT STRUCTURE

    Directory of Open Access Journals (Sweden)

    L. I. Podderеgina

    2014-11-01

    Full Text Available The paper presents new basic criteria and recommendations on formation of networking enterprise management structure at national enterprises that make it possible to improve economic efficiency of their intra-industrial relations.

  16. 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...

  17. Purely Functional Structured Programming

    CERN Document Server

    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 mainstream programmers can reap the benefits of purely functional programming like easily exploitable parallelism while using familiar structured programming syntax and without knowing concepts like monads. A second advantage is that professional purely functional programmers can often avoid hard to read functional code by using structured programming syntax that is often easier to parse mentally.

  18. Operator Structure of TMDs

    CERN Document Server

    Mulders, P J

    2015-01-01

    The focus of this talk is on the transverse components of parton momenta. Like for collinear parton distribution functions (PDFs), we are also in the case of transverse momentum dependent (TMD) PDFs, talking about forward matrix elements. While the collinear PDFs describe only spin-spin correlations, the TMD PDFs (or in short TMDs) include spin-momentum correlations, including also time-reversal-odd (T-odd) correlations. The latter are important in the description of single spin asymmetries. In this way TMDs open up new ways of studying the spin structure of hadrons or they can be used as tools that incorporate hadronic structure also in non-collinear situations. The operator structure of TMDs within QCD, in particular the structure of Wilson lines, is more complex than that for collinear functions leading to various ways of breaking of universality. This breaking of universality, however, can be handled within QCD.

  19. Structure of the Heart

    Science.gov (United States)

    ... Modules Resources Archived Modules Updates Structure of the Heart The human heart is a four-chambered muscular ... serous membrane forms the epicardium. Layers of the Heart Wall Three layers of tissue form the heart ...

  20. 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...

  1. Atomic and molecular structure

    International Nuclear Information System (INIS)

    This book is a textbook for an introductory course of atomic physics for students of chemistry. After an introduction to the mathematical and physical foundations the quantum mechanical theory of atoms is described starting from simple examples of quantum mechanics. Then the atomic structure and the chemical bending are extensively discussed. This book is also suited for physicists who are especially interested in the atomic structure and the theory of chemical reactions. (HSI)

  2. Piping and structural interaction

    OpenAIRE

    Tveit, Siv-Anni

    2015-01-01

    Structural and piping stress analyses are generally conducted separately in most of the situations. A pipe stress analysis is performed based on loads caused by pressure, temperature variations, weight of the pipe (with contents) and blast. The pipes are analysed for several load cases separated into different design types like sustained, expansion and occasional. Established practice in piping design and calculation does not specifically account for structural flexibility. It is assumed that...

  3. 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.

  4. Structural control interaction

    Science.gov (United States)

    Ryan, R. S.; Mowery, D. K.; Winder, S. W.; Worley, H. E.

    1973-01-01

    The basic guidance and control concepts that lead to structural control interaction and structural dynamic loads are identified. Space vehicle ascent flight load sources and the load relieving mechanism are discussed, along with the the characteristics and special problems of both present and future space vehicles including launch vehicles, orbiting vehicles, and the Space Shuttle flyback vehicle. The special dynamics and control analyses and test problems apparent at this time are summarized.

  5. Topological Structure of Mind

    OpenAIRE

    Unno, Wasaburo

    1992-01-01

    [Abstract] Topological representation is undertaken for the function of mind. Klein's bottle so modified as to have the point cross section of infinite area at the intersection of different parts of its own surface is considered as the simplest model of elementary topological structure of mind. Brain may be the manifestation of the multiple combination of such singular elementary structures. Mind is considered to be the excitation of one combination and change of mind is then the transfer of ...

  6. Optimal Stresses in Structures

    OpenAIRE

    Segev, Reuven; deBotton, Gal

    2006-01-01

    For a given external loading on a structure we consider the optimal stresses. Ignoring the material properties the structure may have, we look for the distribution of internal forces or stresses that is in equilibrium with the external loading and whose maximal component is the least. We present an expression for this optimal value in terms of the external loading and the matrix relating the external degrees of freedom and the internal degrees of freedom. The implementation to finite element ...

  7. 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...

  8. Damping in Timber Structures

    OpenAIRE

    Labonnote, Nathalie

    2012-01-01

    Key point to development of environmentally friendly timber structures, appropriate to urban ways of living, is the development of high-rise timber buildings. Comfort properties are nowadays one of the main limitations to tall timber buildings, and an enhanced knowledge on damping phenomena is therefore required, as well as improved prediction models for damping.The aim of this work has consequently been to estimate various damping quantities in timber structures. In particular, models have b...

  9. On Granular Knowledge Structures

    OpenAIRE

    Zeng, Yi; Zhong, Ning

    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)...

  10. Shipping Industry Structure

    OpenAIRE

    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 part of a book on shipping management; the second part should discuss the different management domains in shipping, such as strategy, finance, investment and risk, marketing, operations, organisation ...

  11. Deconstructing Structural Unemployment

    OpenAIRE

    John Schmitt; Kris Warner

    2011-01-01

    Some economic observers argue “structural unemployment” has increased in the wake of the Great Recession, but in this paper we find little support for either of two arguments that suggest that structural unemployment has been on the rise. The first argument focuses on the large increase in unemployment among construction workers. The second argument is that falling house prices have reduced the mobility of unemployed workers — creating a “housing lock” in which unemployed workers, who would o...

  12. Structured Sparse Convolutional Autoencoder

    OpenAIRE

    Hosseini-Asl, Ehsan; Zurada, Jacek M.

    2016-01-01

    This paper aims to improve the feature learning in Convolutional Networks (Convnet) by capturing the structure of objects. A new sparsity function is imposed on the extracted featuremap to capture the structure and shape of the learned object, extracting interpretable features to improve the prediction performance. The proposed algorithm is based on organizing the activation within and across featuremap by constraining the node activities through $\\ell_{2}$ and $\\ell_{1}$ normalization in a s...

  13. The affect structure revisited

    OpenAIRE

    Elefant-Yanni, Véronique Rica; Victoria-Feser, Maria-Pia

    2005-01-01

    In affective psychology, there is a persistent controversy about the number, the nature and the definition of the affect structure dimensions. Responding to the methodological criticisms addressed to the preceding studies, we conciliated the principal theories regarding the affect structure with the same experimental setting. In particular, using the semantic items all around the circumplex we found three bipolar independent dimensions and using only the PANAS semantic items, we found two uni...

  14. 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.

  15. SSI and structural benchmarks

    International Nuclear Information System (INIS)

    This paper presents the latest results of the ongoing program entitled, Standard Problems for Structural Computer Codes, currently being worked on at BNL for the USNRC, Office of Nuclear Regulatory Research. During FY 1986, efforts were focussed on three tasks, namely, (1) an investigation of ground water effects on the response of Category I structures, (2) the Soil-Structure Interaction Workshop and (3) studies on structural benchmarks associated with Category I structures. The objective of the studies on ground water effects is to verify the applicability and the limitations of the SSI methods currently used by the industry in performing seismic evaluations of nuclear plants which are located at sites with high water tables. In a previous study by BNL (NUREG/CR-4588), it has been concluded that the pore water can influence significantly the soil-structure interaction process. This result, however, is based on the assumption of fully saturated soil profiles. Consequently, the work was further extended to include cases associated with variable water table depths. In this paper, results related to cut-off depths beyond which the pore water effects can be ignored in seismic calculations, are addressed. Comprehensive numerical data are given for soil configurations typical to those encountered in nuclear plant sites. These data were generated by using a modified version of the SLAM code which is capable of handling problems related to the dynamic response of saturated soils. Further, the paper presents some key aspects of the Soil-Structure Interaction Workshop (NUREG/CP-0054) which was held in Bethesda, MD on June 1, 1986. Finally, recent efforts related to the task on the structural benchmarks are described

  16. 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.

  17. 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...

  18. Nucleon structure functions

    International Nuclear Information System (INIS)

    In this talk I summarize ideas and plans which have been put forward by members of all collaborations running muon or neutrino experiments at CERN. During our discussions there was general agreement that: i) substantial improvements of structure function measurements in the SPS range are still possible and necessary and ii) it is the responsibility of the present groups and of CERN to provide a ''final'' set of structure functions in the present energy range. (orig.)

  19. Structure of Proton

    OpenAIRE

    Fayyazuddin

    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.

  20. The free tangent structure

    OpenAIRE

    Leung, Poon

    2016-01-01

    At the heart of differential geometry is the construction of the tangent bundle of a manifold. There are various abstractions of this construction, and this paper seeks to compare two of them: Synthetic Differential Geometry (SDG) and Tangent Structures. Tangent structure is defined via giving an underlying category M and a tangent functor T along with a list of natural transformations satisfying a set of axioms, then detailing the behaviour of T in the category End(M). SDG on the other hand ...

  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 to...... oppose the formation of structures. Our simulations suggest that Turing patterns can be a method of self-organization at a length scale of down to 20 molecular diameters...

  2. Categories without structures

    OpenAIRE

    Rodin, Andrei

    2009-01-01

    The popular view according to which Category theory provides a support for Mathematical Structuralism is erroneous. Category-theoretic foundations of mathematics require a different philosophy of mathematics. While structural mathematics studies invariant forms (Awodey) categorical mathematics studies covariant transformations which, generally, don t have any invariants. In this paper I develop a non-structuralist interpretation of categorical mathematics and show its consequences for history...

  3. The foxhole accelerating structure

    International Nuclear Information System (INIS)

    This report examines some properties of a new type of open accelerating structure. It consists of a series of rectangular cavities, which we call foxholes, joined by a beam channel. The power for accelerating the particles comes from an external radiation source and enters the cavities through their open upper surfaces. Analytic and computer calculations are presented showing that the foxhole is a suitable structure for accelerating relativistic electrons

  4. Structural Dynamics, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.

    The present textbook has been written for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M.Sc. students in structural engineering.......The present textbook has been written for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M.Sc. students in structural engineering....

  5. Globalization and political structure

    OpenAIRE

    Gancia, Gino; Giacomo A. M. Ponzetto; Ventura, Jaume

    2016-01-01

    The first wave of globalization (1830-1914) was accompanied by a decline in the number of countries from 125 to 54. The second wave of globalization (1950-present) has led instead to an increase in the number of countries to a record high of more than 190. This paper develops a theoretical framework to study the interaction between globalization and political structure. We show that political structure adapts to expanding trade opportunities in a non-monotonic way. Borders ham...

  6. 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....

  7. 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

  8. 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

  9. Almost Contact Metric Structures Induced by $G_2$ Structures

    OpenAIRE

    Özdemir, Nülifer; Solgun, Mehmet; Aktay, Şirin

    2016-01-01

    We study almost contact metric structures induced by 2-fold vector cross products on manifolds with $G_2$ structures. We get some results on possible classes of almost contact metric structures. Finally we give examples.

  10. Hypercomplex structures on Courant algebroids

    OpenAIRE

    Stienon, Mathieu

    2009-01-01

    Hypercomplex structures on Courant algebroids unify holomorphic symplectic structures and usual hypercomplex structures. In this note, we prove the equivalence of two characterizations of hypercomplex structures on Courant algebroids, one in terms of Nijenhuis concomitants and the other in terms of (almost) torsionfree connections for which each of the three complex structures is parallel.

  11. Controls for space structures

    Science.gov (United States)

    Balas, Mark

    1991-01-01

    Assembly and operation of large space structures (LSS) in orbit will require robot-assisted docking and berthing of partially-assembled structures. These operations require new solutions to the problems of controls. This is true because of large transient and persistent disturbances, controller-structure interaction with unmodeled modes, poorly known structure parameters, slow actuator/sensor dynamical behavior, and excitation of nonlinear structure vibrations during control and assembly. For on-orbit assembly, controllers must start with finite element models of LSS and adapt on line to the best operating points, without compromising stability. This is not easy to do, since there are often unmodeled dynamic interactions between the controller and the structure. The indirect adaptive controllers are based on parameter estimation. Due to the large number of modes in LSS, this approach leads to very high-order control schemes with consequent poor stability and performance. In contrast, direct model reference adaptive controllers operate to force the LSS to track the desirable behavior of a chosen model. These schemes produce simple control algorithms which are easy to implement on line. One problem with their use for LSS has been that the model must be the same dimension as the LSS - i.e., quite large. A control theory based on the command generator tracker (CGT) ideas of Sobel, Mabins, Kaufman and Wen, Balas to obtain very low-order models based on adaptive algorithms was developed. Closed-loop stability for both finite element models and distributed parameter models of LSS was proved. In addition, successful numerical simulations on several LSS databases were obtained. An adaptive controller based on our theory was also implemented on a flexible robotic manipulator at Martin Marietta Astronautics. Computation schemes for controller-structure interaction with unmodeled modes, the residual mode filters or RMF, were developed. The RMF theory was modified to compensate

  12. WEB STRUCTURE MINING

    Directory of Open Access Journals (Sweden)

    CLAUDIA ELENA DINUCĂ

    2011-01-01

    Full Text Available The World Wide Web became one of the most valuable resources for information retrievals and knowledge discoveries due to the permanent increasing of the amount of data available online. Taking into consideration the web dimension, the users get easily lost in the web’s rich hyper structure. Application of data mining methods is the right solution for knowledge discovery on the Web. The knowledge extracted from the Web can be used to raise the performances for Web information retrievals, question answering and Web based data warehousing. In this paper, I provide an introduction of Web mining categories and I focus on one of these categories: the Web structure mining. Web structure mining, one of three categories of web mining for data, is a tool used to identify the relationship between Web pages linked by information or direct link connection. It offers information about how different pages are linked together to form this huge web. Web Structure Mining finds hidden basic structures and uses hyperlinks for more web applications such as web search.

  13. Mesoscale structures in microemulsions

    Energy Technology Data Exchange (ETDEWEB)

    Komura, S [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397 (Japan)

    2007-11-21

    Due to the existence of intermediate mesoscopic internal structures, soft matter exhibits various fascinating non-linear and non-equilibrium phenomena. In this review article, we focus on microemulsions consisting of water, oil, and surfactant from the viewpoint of soft matter physics. Microemulsions exhibit a rich phase behavior as the composition and/or the temperature is varied. In the middle phase, oil and water mix in the presence of surfactant molecules to form a mesoscopic bicontinuous structure. To explain the complex behavior of microemulsions, it is useful to employ phenomenological approaches such as the Ginzburg-Landau theory or the membrane theory. We discuss the Ginzburg-Landau theory and also review the Teubner-Strey model, the Gompper-Schick model, and the two-order-parameter model. Based on these models, we discuss the structure of the middle phase and its wetting transition. The membrane theory proposed by Helfrich is also useful for describing the physical properties of microemulsions. Various structures in microemulsions, such as droplets, bicontinuous and network structures, are properly accounted for by the curvature elasticity model. We focus on the Exxon model which clarifies the physical origin of the middle phase. Within the phenomenological level of description, we review the dynamical aspects of droplet and bicontinuous microemulsions. We also give an overview of microemulsions found in multicomponent polymeric systems (polymeric microemulsions). A discussion on recent applications of microemulsions completes the review. (topical review)

  14. 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.

  15. 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.

  16. Carbon Structure Hazard Control

    Science.gov (United States)

    Yoder, Tommy; Greene, Ben; Porter, Alan

    2015-01-01

    Carbon composite structures are widely used in virtually all advanced technology industries for a multitude of applications. The high strength-to-weight ratio and resistance to aggressive service environments make them highly desirable. Automotive, aerospace, and petroleum industries extensively use, and will continue to use, this enabling technology. As a result of this broad range of use, field and test personnel are increasingly exposed to hazards associated with these structures. No single published document exists to address the hazards and make recommendations for the hazard controls required for the different exposure possibilities from damaged structures including airborne fibers, fly, and dust. The potential for personnel exposure varies depending on the application or manipulation of the structure. The effect of exposure to carbon hazards is not limited to personnel, protection of electronics and mechanical equipment must be considered as well. The various exposure opportunities defined in this document include pre-manufacturing fly and dust, the cured structure, manufacturing/machining, post-event cleanup, and post-event test and/or evaluation. Hazard control is defined as it is applicable or applied for the specific exposure opportunity. The carbon exposure hazard includes fly, dust, fiber (cured/uncured), and matrix vapor/thermal decomposition products. By using the recommendations in this document, a high level of confidence can be assured for the protection of personnel and equipment.

  17. FRP : Strengthened RC Structures

    Science.gov (United States)

    Teng, J. G.; Chen, J. F.; Smith, S. T.; Lam, L.

    2002-01-01

    The strengthening of reinforced concrete (RC) structures using advanced fibre-reinforced polymer (FRP) composites, and in particular the behaviour of FRP-strengthened RC structures is a topic which has become very popular in recent years. This popularity has arisen due to the need to maintain and upgrade essential infrastructure in all parts of the world, combined with the well-known advantages of FRP composites, such as good corrosion resistance and ease for site handling due to their light weight. The continuous reduction in the material cost of FRP composites has also contributed to their popularity. While a great amount of research now exists in the published literature on this topic, it is scattered in various journals and conference proceedings. This book therefore provides the first ever comprehensive, state-of-the-art summary of the existing research on FRP strengthening of RC structures, with the emphasis being on structural behaviour and strength models. The main topics covered include: Bond behaviour Flexural and shear strengthening of beams Column strengthening Flexural strengthening of slabs. For each area, the methods of strengthening are discussed, followed by a description of behaviour and failure modes and then the presentation of rational design recommendations, for direct use in practical design of FRP strengthening measures. Researchers, practicing engineers, code writers and postgraduate students in structural engineering and construction materials, as well as consulting firms, government departments, professional bodies, contracting firms and FRP material suppliers will find this an invaluable resource.

  18. Generalized almost contact structures and generalized Sasakian structures

    OpenAIRE

    Sekiya, Ken'ichi

    2015-01-01

    We introduce generalized almost contact structures which admit the $B$-field transformations on odd dimensional manifolds. We provide definition of generalized Sasakain structures from the view point of the generalized almost contact structures. We obtain a generalized Sasakian structure on a non-compact manifold which does not arise as a pair of ordinary Sasakian structures. However we show that a generalized Sasakian structure on compact 3-dimensional manifold is equivalent to a pair of Sas...

  19. Applications of Structural Bioinformatics for the Structural Genomics Era

    OpenAIRE

    Novotny, Marian

    2007-01-01

    Structural bioinformatics deals with the analysis, classification and prediction of three-dimensional structures of biomacromolecules. It is becoming increasingly important as the number of structures is growing rapidly. This thesis describes three studies concerned with protein-function prediction and two studies about protein structure validation. New protein structures are often compared to known structures to find out if they have a known fold, which may provide hints about their function...

  20. Prosodic structure as a parallel to musical structure

    Directory of Open Access Journals (Sweden)

    Christopher Cullen Heffner

    2015-12-01

    Full Text Available 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.

  1. 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

  2. Structural aspects of tilings

    CERN Document Server

    Ballier, Alexis; Jeandel, Emmanuel

    2008-01-01

    In this paper, we study the structure of the set of tilings produced by any given tile-set. For better understanding this structure, we address the set of finite patterns that each tiling contains. This set of patterns can be analyzed in two different contexts: the first one is combinatorial and the other topological. These two approaches have independent merits and, once combined, provide somehow surprising results. The particular case where the set of produced tilings is countable is deeply investigated while we prove that the uncountable case may have a completely different structure. We introduce a pattern preorder and also make use of Cantor-Bendixson rank. Our first main result is that a tile-set that produces only periodic tilings produces only a finite number of them. Our second main result exhibits a tiling with exactly one vector of periodicity in the countable case.

  3. 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.

  4. Structure functions in chorus

    International Nuclear Information System (INIS)

    In this report a nucleon structure function analysis will be discussed. In CHORUS experiment, lead-scintillator calorimeter was used as active target and in 1998 run a high statistics sample of CC interactions of muon (anti-) neutrinos were collected. This sample was used to extract the structure functions of the nucleons in neutrino interactions. A Monte-Carlo program has been developed to study the efficiencies of the detector and for the proper corrections to be applied to the data. The structure functions, F1, F2, xF3, were extracted using three different kinds of fits. The effects of different systematic dependencies have also been studied. Results have been compared to the earlier experiments, CCFR and CDHSW

  5. 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...

  6. Observed Quasar Structure

    Science.gov (United States)

    Schild, Rudolph E.

    2011-05-01

    With the introduction of microlensing (nano-lensing) and reverberation analysis, understanding of the luminous structure surrounding quasars has gone from theoretical speculation to an observer's sport. Micro-lensing with day timescale has demonstrated that quasars have structure on scales of 1 R_G which we attribute to the inner edge of the accretion disc, at central distance 70 R_G in lo-hard state (radio loud) Q0957 quasar, indicated by reverberation. Reverberation of the dominant optical continuum has been detected in all 55 hi-soft quasars with brightness data, originating in the dusty torus observed in UV-optical and IR reverberation. Microlensing simulation compared to brightness monitoring shows that 2/3 of the UV-optical continuum originates in the outer torus. The observed color effects observed in the microlensing support the existence of inner and outer luminous structure.

  7. Nuclear structure research

    International Nuclear Information System (INIS)

    The Clark University research program in nuclear structure is a collaborative effort involving Clark University personnel, staff members from Brookhaven National Laboratory and an active participation of scientists from the US and other nations. The TRISTAN on-line isotope separator and the capture γ-ray facility at the High Flux Beam Reactor are the primary experimental foci of the program which has four principal research themes, three involving nuclear structure physics and one directed towards astrophysics. These themes are: (1) the manifestation of the proton-neutron interaction in the evolution of nuclear structure and its relation to collectivity, (2) the appearance and the role of symmetries and supersymmetries in nuclei, (3) the study of new regions of magic nuclei, and (4) the characterization of nuclei important in r-process stellar nucleosynthesis

  8. Patchworking Network Structures

    DEFF Research Database (Denmark)

    Norus, Jesper

    2004-01-01

    groups has been treated as a contingent factor.However, little attention has been given to the managerial efforts that entrepreneurshave make to establish the fit between small firms, university research, and publicpolicies such as regulatory policies and R&D policies through network-type structures...... analyzes fourdifferent managerial strategies of how to create network structures to deal with theinterfaces between industry, university and public institutions. The research-orientedstrategy, the incubator strategy, the industrial-partnering strategy, and the policyorientedstrategy. The research......-oriented strategyfocuses on the problem of having products approved by the public authorities. The aimof the article is to demonstrate how SBFs over time develop network structures throughpatchwork-like activities, ongoing and overlapping activities, that serve as a blueprintfor the management...

  9. 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...

  10. 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...

  11. Socio-Technical Structure

    DEFF Research Database (Denmark)

    Rose, Jeremy; Lindgren, Rikard; Henfridsson, Ole

    2004-01-01

    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......When it comes to investigating the relationship between the social and the technical, IS has been a net importer of theories. These theories often carry differing interpretations of central concepts, which then become both confusing and difficult to integrate. In response to calls for IS to become...... 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...

  12. 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.

  13. Bridgescaping - Contextual Structural Design

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Almegaard, Henrik

    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...... also encourage engineers to focus more on the aesthetic aspects of their design and the way their structures will work in the context of the surroundings. This paper will present a series of contemporary bridge structures to provide a short history of the tendency described above and discuss design at...

  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. 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...

  16. 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...... program based on the finite element method for the analysis of cracks in structural elements is presented; in this program the interface and elements with embedded discontinuities are implemented....... 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...

  17. 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.

  18. Growing Timber Structures

    DEFF Research Database (Denmark)

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

    2013-01-01

    computational models. Hence the lack of feedback about the impact of a design decision onto the design has been identified as source of problems. This paper reports on two speculative projects that integrate generative processes, based on natural growth patterns, with feedback from simulation in order to......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...

  19. Structure Learning in Audio

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch

    using pitch dynamics is suggested. The other approach is finding structures between the mixings of multiple sources based on an assumption of statistical independence of the sources. Three different audio classification tasks have been investigated. Audio classification into three classes, music, noise...... 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...

  20. Structural Coupling and Translation

    DEFF Research Database (Denmark)

    Tække, Jesper

    structural couplings between psychic and social systems (Luhmann 2002: 275, Tække 2011). In this way media are seen as a necessary third, making it possible for two different kinds of systems to process, using complexity from one another - leaving out the idea of direct transmission. In actor-network theory...... compare the semantics of their concepts. The paper first provides an analysis and discussion of language as the mechanism of structural coupling between the levels of psychic and social systems. Then the article provides an analysis and discussion of translation as a transformation process between actors...

  1. Structure of lithium tetrafluoroindate

    International Nuclear Information System (INIS)

    LiInF4, Mr=197.75, orthorhombic, Pbcn, a=4.752(1), b=11.721(4), c=4.971(1) A. The three-dimensional network consists of (InF4)nn- layers formed by InF6 corner-sharing octahedra perpendicular to the b axis and connected by Li+ ions forming (LiF4)n3n- chains running along the c direction. The chains are built up by LiF6 octahedra sharing common edges. This structure appears to be a new structure type within the AMF4 compounds. (orig./GSCH)

  2. 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.

  3. Integrated Structural Design Education

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Almegaard, Henrik

    2011-01-01

    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......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...... of a project, function well in design teams, and comply with EU EIA demands....

  4. Optimal Stresses in Structures

    CERN Document Server

    Segev, R; Botton, Gal de; Segev, Reuven

    2006-01-01

    For a given external loading on a structure we consider the optimal stresses. Ignoring the material properties the structure may have, we look for the distribution of internal forces or stresses that is in equilibrium with the external loading and whose maximal component is the least. We present an expression for this optimal value in terms of the external loading and the matrix relating the external degrees of freedom and the internal degrees of freedom. The implementation to finite element models consisting of elements of uniform stress distributions is presented. Finally, we give an example of stress optimization for of a two-element model of a cylinder under external traction.

  5. Integrated Structural Design Education

    DEFF Research Database (Denmark)

    Bjerregaard Jensen, Lotte; Almegaard, Henrik

    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...... 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 of a...

  6. Objective Eulerian coherent structures

    Science.gov (United States)

    Serra, Mattia; Haller, George

    2016-05-01

    We define objective Eulerian Coherent Structures (OECSs) in two-dimensional, non-autonomous dynamical systems as the 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 an 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.

  7. 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.

  8. Capital Structure and Assets

    DEFF Research Database (Denmark)

    Flor, Christian Riis

    2008-01-01

    This paper analyzes a firm's capital structure choice when assets have outside value. Valuable assets implicitly provide a collateral and increase tax shield exploitation. The key feature in this paper is asset value uncertainty, implying that it is unknown ex ante whether the equity holders ex...... 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...

  9. Structural Stator Spacers

    DEFF Research Database (Denmark)

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

    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......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, a...

  10. Structural mechanics simulations

    International Nuclear Information System (INIS)

    Sandia National Laboratory has a very broad structural capability. Work has been performed in support of reentry vehicles, nuclear reactor safety, weapons systems and components, nuclear waste transport, strategic petroleum reserve, nuclear waste storage, wind and solar energy, drilling technology, and submarine programs. The analysis environment contains both commercial and internally developed software. Included are mesh generation capabilities, structural simulation codes, and visual codes for examining simulation results. To effectively simulate a wide variety of physical phenomena, a large number of constitutive models have been developed

  11. 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

  12. 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.

  13. 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...... around vertical cylinders; flow and scour processes at detached breakwaters; flow and scour processes at submerged breakwaters; and the effect of turbulence on sediment transport; and (3) Sediment behaviour close to the structure with the subheadings: field measurement and analysis of wave-induced pore...

  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. Structural interaction with control systems

    Science.gov (United States)

    Noll, R. B.; Zvara, J.

    1971-01-01

    A monograph which assesses the state of the art of space vehicle design and development is presented. The monograph presents criteria and recommended practices for determining the structural data and a mathematical structural model of the vehicle needed for accurate prediction of structure and control-system interaction; for design to minimize undesirable interactions between the structure and the control system; and for determining techniques to achieve the maximum desirable interactions and associated structural design benefits. All space vehicles are treated, including launch vehicles, spacecraft, and entry vehicles. Important structural characteristics which affect the structural model used for structural and control-system interaction analysis are given.

  16. Robustness Analyses of Timber Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard; Hald, Frederik

    2013-01-01

    The robustness of structural systems has obtained a renewed interest arising from a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. In order to minimise the likelihood of such disproportionate structural failures, many...... modern building codes consider the need for the robustness of structures and provide strategies and methods to obtain robustness. Therefore, a structural engineer may take necessary steps to design robust structures that are insensitive to accidental circumstances. The present paper summaries issues with...... respect to robustness of timber structures and will discuss the consequences of such robustness issues related to the future development of timber structures....

  17. Classification & Structure of Blood Vessels

    Science.gov (United States)

    ... Thyroid & Parathyroid Glands Adrenal Gland Pancreas Gonads Other Endocrine Glands Review Quiz Cardiovascular System Heart Structure of the Heart Physiology of the Heart Blood Classification & Structure of Blood ...

  18. 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....

  19. Structure of the nucleon

    International Nuclear Information System (INIS)

    Generalized parton distributions provide information on the longitudinal and transverse distribution of partons in the fast moving nucleon. Furthermore, they contain information on the spin structure of the nucleon. First results of a lattice study of generalized parton distributions are presented. (orig.)

  20. 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…

  1. Acicular photomultiplier photocathode structure

    Science.gov (United States)

    Craig, Richard A.; Bliss, Mary

    2003-09-30

    A method and apparatus for increasing the quantum efficiency of a photomultiplier tube by providing a photocathode with an increased surface-to-volume ratio. The photocathode includes a transparent substrate, upon one major side of which is formed one or more large aspect-ratio structures, such as needles, cones, fibers, prisms, or pyramids. The large aspect-ratio structures are at least partially composed of a photoelectron emitting material, i.e., a material that emits a photoelectron upon absorption of an optical photon. The large aspect-ratio structures may be substantially composed of the photoelectron emitting material (i.e., formed as such upon the surface of a relatively flat substrate) or be only partially composed of a photoelectron emitting material (i.e., the photoelectron emitting material is coated over large aspect-ratio structures formed from the substrate material itself.) The large aspect-ratio nature of the photocathode surface allows for an effective increase in the thickness of the photocathode relative the absorption of optical photons, thereby increasing the absorption rate of incident photons, without substantially increasing the effective thickness of the photocathode relative the escape incidence of the photoelectrons.

  2. Control Augmented Structural Synthesis

    Science.gov (United States)

    Lust, Robert V.; Schmit, Lucien A.

    1988-01-01

    A methodology for control augmented structural synthesis is proposed for a class of structures which can be modeled as an assemblage of frame and/or truss elements. It is assumed that both the plant (structure) and the active control system dynamics can be adequately represented with a linear model. The structural sizing variables, active control system feedback gains and nonstructural lumped masses are treated simultaneously as independent design variables. Design constraints are imposed on static and dynamic displacements, static stresses, actuator forces and natural frequencies to ensure acceptable system behavior. Multiple static and dynamic loading conditions are considered. Side constraints imposed on the design variables protect against the generation of unrealizable designs. While the proposed approach is fundamentally more general, here the methodology is developed and demonstrated for the case where: (1) the dynamic loading is harmonic and thus the steady state response is of primary interest; (2) direct output feedback is used for the control system model; and (3) the actuators and sensors are collocated.

  3. Auxiliary building structures

    International Nuclear Information System (INIS)

    Five types of auxiliary structures are described such as were used during the construction of the Dukovany nuclear power plant, namely a portable staircase tower, a stable staircase tower, mobile tower scaffolding, mobile scaffolding on a crane track and a scaffold cradle. Basic technical data for all types of scaffolding are given. (Pu)

  4. Evolving production network structures

    DEFF Research Database (Denmark)

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

    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...

  5. 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...

  6. 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.

  7. 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. PMID:26357362

  8. Diquark structure of baryons

    International Nuclear Information System (INIS)

    Three body calculations for studying the baryons are performed in a non-relativistic treatment with three quarks interacting via Bhaduri's potential. From the resulting wave functions, it is analysed under which conditions can a diquark structure occurs. Several photos showing quark distributions inside the baryons are presented and discussed in details

  9. Bootstrapping structured page segmentation

    Science.gov (United States)

    Ma, Huanfeng; Doermann, David S.

    2003-01-01

    In this paper, we present an approach to the bootstrap learning of a page segmentation model. The idea evolves from attempts to segment dictionaries that often have a consistent page structure, and is extended to the segmentation of more general structured documents. In cases of highly regular structure, the layout can be learned from examples of only a few pages. The system is first trained using a small number of samples, and a larger test set is processed based on the training result. After making corrections to a selected subset of the test set, these corrected samples are combined with the original training samples to generate bootstrap samples. The newly created samples are used to retrain the system, refine the learned features and resegment the test samples. This procedure is applied iteratively until the learned parameters are stable. Using this approach, we do not need to initially provide a large set of training samples. We have applied this segmentation to many structured documents such as dictionaries, phone books, spoken language transcripts, and obtained satisfying segmentation performance.

  10. Adaptive building skin structures

    International Nuclear Information System (INIS)

    The concept of adaptive and morphing structures has gained considerable attention in the recent years in many fields of engineering. In civil engineering very few practical applications are reported to date however. Non-conventional structural concepts like deployable, inflatable and morphing structures may indeed provide innovative solutions to some of the problems that the construction industry is being called to face. To give some examples, searches for low-energy consumption or even energy-harvesting green buildings are amongst such problems. This paper first presents a review of the above problems and technologies, which shows how the solution to these problems requires a multidisciplinary approach, involving the integration of architectural and engineering disciplines. The discussion continues with the presentation of a possible application of two adaptive and dynamically morphing structures which are proposed for the realization of an acoustic envelope. The core of the two applications is the use of a novel optimization process which leads the search for optimal solutions by means of an evolutionary technique while the compatibility of the resulting configurations of the adaptive envelope is ensured by the virtual force density method

  11. 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 ...

  12. Structural Pest Control.

    Science.gov (United States)

    Kahn, M. S.; Hoffman, W. M.

    This manual is designed for those who seek certification as pesticide applicators for industrial, institutional, structural, and health-related pest control. It is divided into six sections covering general pest control, wood-destroying organisms, bird control, fumigation, rodent control, and industrial weed control. The manual gives information…

  13. Magnetic Structure of Erbium

    DEFF Research Database (Denmark)

    Gibbs, D.; Bohr, Jakob; Axe, J. D.; Moncton, D. E.; d'Amico, K. L.

    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 of...

  14. 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...

  15. 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 of...

  16. 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…

  17. Hyphal structures in Hydnums

    NARCIS (Netherlands)

    Maas Geesteranus, R.A.

    1962-01-01

    In this paper descriptions are given of the hyphal structure in the hydnaceous genera Climacodon P. Karst., Creolophus P. Karst., Donkia Pilát, Hydnellum P. Karst., Mycoleptodonoides Nikol., Mycorrhaphium Maas G. (which is introduced as a new genus), Phellodon P. Karst., Sarcodon P. Karst., and Stec

  18. Structural integrity monitoring

    International Nuclear Information System (INIS)

    The problems of technical diagnosis and testing of responsible different-purpose structures and equipment-bridges, marine oil-producing platforms, aircrafts, nuclear and chemical reactors, underground cables, pipelines, are presented. Different methods of monitoring and the testing equipment are described. The nature of damages and information processing for making decisions are analyzed

  19. The proton spin structure

    International Nuclear Information System (INIS)

    The author presents first the theoretical frame of the nucleon spin structure study carried out through the deep inelastic scattering of polarised leptons on a polarised target. The interest of the lepton scattering reaction to study the hadronic structure is discussed and the formalism of the inclusive inelastic scattering presented. If the target and the beam are both polarised, the formalism enables to connect the experimentally measured asymmetries to the contribution of quarks to the spin of nucleon. The recent knowledge about the nucleon spin structure is also presented. The Bjorken sum rule is then discussed: it correlates the difference of spin structure between proton and neutron to the neutron lifetime. Then, the author mentions the experimental results of SMC (CERN) and E142, E143 (SLAC). The transition from rough asymmetry to the g sub 1 structure function integral is discussed as well as the main causes of uncertainty. Compared to theoretical data, the measurements confirm the reliability of the Bjorken sum rule. They also confirm the deficit of the quark contribution with respect to the naive unpolarized strange sea model. The possible origins of this discrepancy and the contributions of the current and planned experiments are also discussed. Finally, the author brings up the next major step for nucleon spin studies: the estimation of the gluon contribution. He discusses the experimental knowledge about the polarised gluon distribution function with regard to the multiple existing parameter set. Concerning the experimental determination of this distribution function, outlooks are proposed with respect to feasibility on current experimental facilities. (N.T.)

  20. Structural Dynamics and Control Interaction of Flexible Structures

    Science.gov (United States)

    Ryan, Robert S. (Editor); Scofield, Harold N. (Editor)

    1987-01-01

    A workshop on structural dynamics and control interaction of flexible structures was held to promote technical exchange between the structural dynamics and control disciplines, foster joint technology, and provide a forum for discussing and focusing critical issues in the separate and combined areas. Issues and areas of emphasis were identified in structure-control interaction for the next generation of flexible systems.

  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. 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.

  3. Lewis Structures Technology, 1988. Volume 2: Structural Mechanics

    Science.gov (United States)

    1988-01-01

    Lewis Structures Div. performs and disseminates results of research conducted in support of aerospace engine structures. These results have a wide range of applicability to practitioners of structural engineering mechanics beyond the aerospace arena. The engineering community was familiarized with the depth and range of research performed by the division and its academic and industrial partners. Sessions covered vibration control, fracture mechanics, ceramic component reliability, parallel computing, nondestructive evaluation, constitutive models and experimental capabilities, dynamic systems, fatigue and damage, wind turbines, hot section technology (HOST), aeroelasticity, structural mechanics codes, computational methods for dynamics, structural optimization, and applications of structural dynamics, and structural mechanics computer codes.

  4. MONITORING OF THE METAL STRUCTURAL STATE BY ACOUSTICAL STRUCTURAL NOISE

    Directory of Open Access Journals (Sweden)

    V. V. Muraviev

    2015-03-01

    Full Text Available To determine the structural state of the metal as an informative parameter the structural acoustic noise is proposed. The paper represents the experimental results of the use at acoustical structural noise for the determination at the structural state of carbon pipe steels exposed by heat treatment, corrosion and tensile loads. The effect of grain size, corrosion and tensile loads on the level of structural noise is discussed.

  5. Spectral Analysis for an Asymmetrical Structure Considering Soil Structure Interaction

    OpenAIRE

    Olariu, Cerasela Panseluța; Movilă, Mihaela

    2014-01-01

    In civil engineering, problems which deal with the effects of the structural asymmetry are more frequently encountered. Besides the fact that the majority of the design provisions recommend that the structure should be symmetrical in plane as well as in elevation, there are various situations in which asymmetrical structures are designed. The torsional response of these types of structures can be influenced also by taking into consideration the soil structure interaction effects. The...

  6. 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 ...

  7. 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...

  8. 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.

  9. 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.

  10. Robustness Evaluation of Timber Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

    2009-01-01

    Robustness of structural systems 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.......Robustness of structural systems 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....

  11. 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...

  12. 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...

  13. Structure of lithium tetrafluoroindate

    Energy Technology Data Exchange (ETDEWEB)

    Gravereau, P.; Chaminade, J.P.; Gaewdang, T.; Grannec, J.; Pouchard, M.; Hagenmuller, P. (Bordeaux-1 Univ., 33 - Talence (France). Lab. de Chimie du Solide)

    1992-05-15

    LiInF{sub 4}, M{sub r}=197.75, orthorhombic, Pbcn, a=4.752(1), b=11.721(4), c=4.971(1) A. The three-dimensional network consists of (InF{sub 4}){sub n}{sup n-} layers formed by InF{sub 6} corner-sharing octahedra perpendicular to the b axis and connected by Li{sup +} ions forming (LiF{sub 4}){sub n}{sup 3n-} chains running along the c direction. The chains are built up by LiF{sub 6} octahedra sharing common edges. This structure appears to be a new structure type within the AMF{sub 4} compounds. (orig./GSCH).

  14. 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.

  15. DNA: Structure and function

    DEFF Research Database (Denmark)

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

    1998-01-01

    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 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...... 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...

  16. 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.

  17. Radio structure in quasars

    International Nuclear Information System (INIS)

    In this thesis, observational attention is given to the extended extragalactic radio sources associated with quasars. The isolated compact radio sources, often identified with quasars, are only included in the discussions. Three aspects of the radio structure in quasars and their cosmic evolution are considered: a study of the parsec scale morphology in quasar cores, in relation to the extended morphologies; an investigation of possible epoch dependent hotspot properties as well as a more detailed investigation of this fine scale structure; a VLA project was carried out to obtain morphological information on scales of 0.5 arcsec on high redshift quasars and to investigate possible epoch dependent morphological properties. MERLIN observations at 0.1 arcsec resolution to supplement the VLA data were initiated. (Auth.)

  18. 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.

  19. Structure of exoplanets.

    Science.gov (United States)

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

    2014-09-01

    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

  20. Plasma resistant structural member

    International Nuclear Information System (INIS)

    The present invention provides a plasma resistant ceramic material of a plasma confining device for a tokamak thermonuclear device. Namely, the structural member of the present invention comprises a ceramic-based fibrous composite material having a matrix mainly comprising SiC and fibers composited in the matrix, as a constitution undergoing heat fluxes from plasmas. It is constituted such that it undergoes heat fluxes from plasmas by way of a surface in the direction having the highest heat conductivity. Since the fibers are a reinforcing material for enhancing the toughness of the SiC matrix, SiC type fibers are used. With such a constitution, the structural member has excellent properties such as high temperature strength, high temperature creeping characteristics, high heat stability, elasticity, heat conductivity and sputtering resistance, in addition to provide a high melting point (high sublimation temperature) and a low atomic weight. (N.H.)

  1. Structural assembly demonstration experiment

    Science.gov (United States)

    Stokes, J. W.

    1982-01-01

    The experiment is of an operational variety, designed to assess crew capability in Large Space System (LSS) assembly. The six Structural Assembly Demonstration Experiment objectives include: (1) the establishment of a quantitative correlation between LSS neutral buoyancy simulation and on-orbit assembly operations in order to enhance the validity of those assembly simulations; (2) the quantitative study of the capabilities and mechanics of human assembly in an Extravehicular Activity environment; (3) the further corroboration of the LSS Assembly Analysis cost algorithm through the obtainment of hard data base information; (4) the verification of LSS assembly techniques and timeless, as well as the identification of crew imposed loads and assembly aid requirements and concepts; (5) verification of a Launch/Assembly Platform structure concept for other LSS missions; and (6) lastly, to advance thermal control concepts through a flexible heat pipe.

  2. Modulated structure of nepheline

    OpenAIRE

    Friese, K.; Grzechnik, A.; Petricek, V.; Schönleber, A.; Smaalen, S. van; Morgenroth, W.

    2011-01-01

    The incommensurately modulated structure of a natural nepheline of composition K(0.54)Na(3.24)Ca(0.03)Al(3.84)Si(4.16)O(16) has been determined in superspace. The compound crystallizes in the trigonal centered superspace group X3(00γ)0 with γ = 0.2048 (10), X = (0, 0, 0, 0), (1/3, 2/3, 0, 2/3), (2/3, 1/3, 0, 1/3), a = 17.2889 (8) and c = 8.3622 (10) Å. The structure is characterized by a framework of corner-connected (Al,Si)O(4) tetrahedra. The additional cations are incorporated in two diffe...

  3. 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.

  4. TBR-2 structural analysis

    International Nuclear Information System (INIS)

    This paper presents the structural analysis developed during the TBR-2 tokamak project studies. Starting with electromagnetic interaction forces on each, toroidal and poloidal coils many structural calculations have been carried out using locally developed usual E.M. interaction codes and a finite element method stress code. Following the analysis it has been determined that there is radially inward force of 1235 kN and overturning torque of 243 kNm acting on toroidal coils. This stress and displacements due to in plane loads have been calculated using a finite element code which show that the maximum stress of 240 MPa and displacement of 0.21 mm can be present at the inner part of the toroidal field coil. (Author)

  5. Pairing in hadron structure

    International Nuclear Information System (INIS)

    A many-body approach to hadron structure is presented, in which we consider two parton species: spin-0 (b-partons), and spin-1/2 (f-partons). We extend a boson and a fermion pairing scheme for the b-, and f-partons respectively, into a Yang-Mills gauge theory. The main feature of this theory is that the gauge field is not identified with the usual gluon field variable in QCD. We study the confinement problem of the hadron constituents, and obtain, for low temperatures, partons that are confined by energy gaps. As the critical temperatures for the corresponding phase transitions are approached, the energy gap gradually disappears, and confinement is lost. The theory goes beyond the non-relativistic harmonic oscillator quark model, in the sense of giving physical reasons why a non-relativistic approximation is adequate in describing the internal dynamics of hadron structure. (author)

  6. Alignments of RNA structures.

    Science.gov (United States)

    Blin, Guillaume; Denise, Alain; Dulucq, Serge; Herrbach, Claire; Touzet, Hélène

    2010-01-01

    We describe a theoretical unifying framework to express the comparison of RNA structures, which we call alignment hierarchy. This framework relies on the definition of common supersequences for arc-annotated sequences and encompasses the main existing models for RNA structure comparison based on trees and arc-annotated sequences with a variety of edit operations. It also gives rise to edit models that have not been studied yet. We provide a thorough analysis of the alignment hierarchy, including a new polynomial-time algorithm and an NP-completeness proof. The polynomial-time algorithm involves biologically relevant edit operations such as pairing or unpairing nucleotides. It has been implemented in a software, called gardenia, which is available at the Web server http://bioinfo.lifl.fr/RNA/gardenia. PMID:20431150

  7. 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.

  8. Structural analysis of DAEs

    DEFF Research Database (Denmark)

    Poulsen, Mikael Zebbelin

    2002-01-01

    Differential algebraic equations (DAEs) constitute a fundamental model class for many modelling purposes in engineering and other sciences, especially for dynamical simulation of component based systems. This thesis describes a practical methodology and approach for analysing general DAE. The...... underlying ODE for finding consistent initial values and solve the initial value problem for the original DAE. As a methodology for integrating the augmented underlying ODE, the dummy derivative method is investigated. The methodology avoids the traditional stability and drift-of problems of using the...... structural index analysis of DAE is original in the sense that it is based on a new matrix representation of the structural information of a general DAE system instead of a graph oriented representation. Also the presentation of the theory is found to be more complete compared to other presentations, since...

  9. Structure of ordered alloys

    International Nuclear Information System (INIS)

    Recent progress in studying ordered alloys by lattice fringe imaging is reviewed. Firstly the optimum experimental conditions for producing images suitable for interpretation are outlined. Secondly lattice and conventional imaging are compared and the advantages of the former for obtaining atomic level detail and compositional estimates are described. Finally some important results from this program are discussed, particularly the evidence for a microdomain model of short-range order and the fine structure of various ordered lattice defects

  10. Cyclical Unemployment, Structural Unemployment

    OpenAIRE

    Peter A. Diamond

    2013-01-01

    Whenever unemployment stays high for an extended period, it is common to see analyses, statements, and rebuttals about the extent to which the high unemployment is structural, not cyclical. This essay views the Beveridge Curve pattern of unemployment and vacancy rates and the related matching function as proxies for the functioning of the labor market and explores issues in that proxy relationship that complicate such analyses. Also discussed is the concept of mismatch.

  11. 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

  12. Web Structure Mining

    OpenAIRE

    CLAUDIA ELENA DINUCĂ

    2011-01-01

    The World Wide Web became one of the most valuable resources for information retrievals and knowledge discoveries due to the permanent increasing of the amount of data available online. Taking into consideration the web dimension, the users get easily lost in the web’s rich hyper structure. Application of data mining methods is the right solution for knowledge discovery on the Web. The knowledge extracted from the Web can be used to raise the performances for Web information retrievals, quest...

  13. Photon Structure Function

    OpenAIRE

    Godbole, Rohini M.(Centre for High Energy Physics, Indian Institute of Science, 560012, Bangalore, India)

    1996-01-01

    After briefly explaining the idea of photon structure functions (F gamma2, F gammaL),I review the current theoretical and experimental developements in the subject of extraction of q-gamma from a study of the Deep Inelastic Scattering (DIS). I then end by pointing out recent progress in getting information about the parton content of the photon from hard processes other than DIS.

  14. Structural Modifications of Lignosulphonates

    OpenAIRE

    Areskogh, Dimitri

    2011-01-01

    Lignosulphonates are by‐products from the sulphite pulping process for the manufacture ofspecialty dissolving pulps and paper. During the liberation of the cellulose, the lignin isfractionated and solubilised through covalent addition of sulphonic acid groups at variouspositions in the structure. The formed sulphonated lignin, lignosulphonate is then furtherisolated and refined. The amphiphilic nature of lignosulphonates has enabled them to be used as additives to varioussuspensions to improv...

  15. Teach us atom structure

    International Nuclear Information System (INIS)

    This book is written to teach atom structure in very easy way. It is divided into nine chapters, which indicates what is the components of matter? when we divide matter continuously, it becomes atom, what did atom look like? particles comprised of matter is not only atom, discover of particles comprised of atom, symbol of element, various radiation, form alchemy to nuclear transmutation, shape of atom is evolving. It also has various pictures in each chapters to explain easily.

  16. Teach us atom structure

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Suh Yeon

    2006-08-15

    This book is written to teach atom structure in very easy way. It is divided into nine chapters, which indicates what is the components of matter? when we divide matter continuously, it becomes atom, what did atom look like? particles comprised of matter is not only atom, discover of particles comprised of atom, symbol of element, various radiation, form alchemy to nuclear transmutation, shape of atom is evolving. It also has various pictures in each chapters to explain easily.

  17. Structure: form, beauty, space

    OpenAIRE

    O'Donovan, James

    2012-01-01

    non-peer-reviewed The objective of my thesis is to explore the various elements that make structure architecture. Through investigation into thinness, material, span, space and soundscape, I wish to create an architecture which can appeal to the senses and have value form many years to come. I propose to interrogate these qualities with the demanding programme of aircraft cargo and maintenance on the site of Shannon Airport, which is situated on the shannon estuary and to...

  18. RNA thermodynamic structural entropy

    OpenAIRE

    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 th...

  19. Latent Structured Ranking

    OpenAIRE

    Weston, Jason; Blitzer, John

    2012-01-01

    Many latent (factorized) models have been proposed for recommendation tasks like collaborative filtering and for ranking tasks like document or image retrieval and annotation. Common to all those methods is that during inference the items are scored independently by their similarity to the query in the latent embedding space. The structure of the ranked list (i.e. considering the set of items returned as a whole) is not taken into account. This can be a problem because the set of top predicti...

  20. Magnetic structures for spintronics

    International Nuclear Information System (INIS)

    This short review covers the field of magneto electronics or spintronics, which has been developed very fast in recent years. The idea of electronic devices that exploit both the charge and spin of electron for their operation has given rise to this new field of science and technology. Current and anticipated future research frontiers in magnetic structures are discussed from perspective of practical devices. (author)

  1. Structure of gramicidin A.

    OpenAIRE

    Wallace, B.A.

    1986-01-01

    Gramicidin A, a hydrophobic linear polypeptide, forms channels in phospholipid membranes that are specific for monovalent cations. Nuclear Magnetic Resonance (NMR) spectroscopy provided the first direct physical evidence that the channel conformation in membranes is an amino terminal-to-amino terminal helical dimer, and circular dichroism (CD) spectroscopy has shown the sensitivity of its conformation to different environments and the structural consequences of ion binding. The three-dimensio...

  2. Structured Learning Modulo Theories

    OpenAIRE

    Teso, Stefano; Sebastiani, Roberto; Passerini, Andrea

    2014-01-01

    Modelling problems containing a mixture of Boolean and numerical variables is a long-standing interest of Artificial Intelligence. However, performing inference and learning in hybrid domains is a particularly daunting task. The ability to model this kind of domains is crucial in "learning to design" tasks, that is, learning applications where the goal is to learn from examples how to perform automatic {\\em de novo} design of novel objects. In this paper we present Structured Learning Modulo ...

  3. Design bases - Concrete structures

    International Nuclear Information System (INIS)

    The most suitable title for Section 2 is 'Design Bases', which covers not only calculation but also the following areas: - Structural design concepts. - Project criteria. - Material specifications. These concepts are developed in more detail in the following sections. The numbering in this document is neither complete nor hierarchical since, for easier cross referencing, it corresponds to the paragraphs of Eurocode 2 Part 1 (hereinafter 'EUR-2') which are commented on. (author)

  4. Banking structure redesigned

    OpenAIRE

    VARMA, VIJAYA KRUSHNA

    2009-01-01

    Banking structure is redesigned to make India a fully digital nation and to usher in 100% E-governance. Multi dimensional and multipurpose savings account - It is the main keel of this restructured banking. Purpose of this multi dimensional account 1. This savings account can be used for receiving, storing and spending of money. 2. It can be used for buying, selling and holding property rights of immovable properties like lands, plots, flats and commercial establishments. 3...

  5. Stellar structure and evolution

    International Nuclear Information System (INIS)

    This book introduces the theory of the internal structure of stars and their evolution in time. It presents the basic physics of stellar interiors, methods for solving the underlying equations, and the most important results necessary for understanding the wide variety of stellar types and phenomena. The evolution of stars is discussed from their birth through normal evolution to possibly spectacular final stages. Chapters on stellar oscillations and rotation are included

  6. Stellar structure and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Kippernhahn, R. (MPI fur Physik und Astrophysik, Garching (DE)); Weigert, A. (Sternwarte, Hamberg (DE))

    1990-01-01

    This book introduces the theory of the internal structure of stars and their evolution in time. It presents the basic physics of stellar interiors, methods for solving the underlying equations, and the most important results necessary for understanding the wide variety of stellar types and phenomena. The evolution of stars is discussed from their birth through normal evolution to possibly spectacular final stages. Chapters on stellar oscillations and rotation are included.

  7. Structure-specific endonucleases

    DEFF Research Database (Denmark)

    Minocherhomji, Sheroy; Hickson, Ian D

    2014-01-01

    Fragile sites are conserved loci predisposed to form breaks in metaphase chromosomes. The inherent instability of these loci is associated with chromosomal rearrangements in cancers and is a feature of cells from patients with chromosomal instability syndromes. One class of fragile sites, the com......, leading to the formation of ultra-fine anaphase bridges (UFBs) and micronuclei. We discuss recent developments in the CFS field; in particular, the role of DNA structure-specific endonucleases in promoting cleavage at CFSs....

  8. Reference structure tomography

    Science.gov (United States)

    Brady, David J.; Pitsianis, Nikos P.; Sun, Xiaobai

    2004-07-01

    Reference structure tomography (RST) uses multidimensional modulations to encode mappings between radiating objects and measurements. RST may be used to image source-density distributions, estimate source parameters, or classify sources. The RST paradigm permits scan-free multidimensional imaging, data-efficient and computation-efficient source analysis, and direct abstraction of physical features. We introduce the basic concepts of RST and illustrate the use of RST for multidimensional imaging based on a geometric radiation model.

  9. Structure or Noise?

    OpenAIRE

    Still, Susanne; Crutchfield, James P.

    2007-01-01

    We show how rate-distortion theory provides a mechanism for automated theory building by naturally distinguishing between regularity and randomness. We start from the simple principle that model variables should, as much as possible, render the future and past conditionally independent. From this, we construct an objective function for model making whose extrema embody the trade-off between a model's structural complexity and its predictive power. The solutions correspond to a hierarchy of mo...

  10. 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.

  11. 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

  12. Structure Learning in Audio

    OpenAIRE

    Nielsen, Andreas Brinch; Hansen, Lars Kai

    2009-01-01

    By having information about the setting a user is in, a computer is able to make decisions proactively to facilitate tasks for the user. Two approaches are taken in this thesis to achieve more information about an audio environment. One approach is that of classifying audio, and a new approach using pitch dynamics is suggested. The other approach is finding structures between the mixings of multiple sources based on an assumption of statistical independence of the sources. Three different aud...

  13. 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.

  14. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    The Fourth International Conference on selected topics in nuclear structure was held at Dubna in July 1994 on recent experimental and theoretical investigations in nuclear structure. Topics discussed were the following: nuclear structure at low-energy excitations (collective quasiparticle phenomena, proton-neutron interactions, microscopic and phenomenological theories of nuclear structure; nuclear structure studies with charged particles. heavy ions, neutrons and photons; nuclei at high angular momenta and superdeformation, structure and decay properties of giant resonances, charge-exchange resonances and β-decay; semiclassical approach of large amplitude collective motion and structure of hot nuclei

  15. Integrated materials–structural models

    DEFF Research Database (Denmark)

    Stang, Henrik; Geiker, Mette Rica

    2008-01-01

    , 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 of...... structural modelling and materials concepts will both operational in both identifying important research issues and in answering the ‘real’ needs of society. Integrated materials-structural models will allow synergy to develop between materials and structural research. On one side the structural modelling...... should define a framework in which materials research results eventually should fit in and on the other side the materials research should define needs and capabilities in structural modelling. Integrated materials-structural models of a general nature are almost non-existent in the field of cement based...

  16. Visual Structure Language; TOPICAL

    International Nuclear Information System (INIS)

    In this paper we describe a new language, Visual Structure Language (VSL), designed to describe the structure of a program and explain its pieces. This new language is built on top of a general-purpose language, such as C. The language consists of three extensions: explanations, nesting, and arcs. Explanations are comments explicitly associated with code segments. These explanations can be nested. And arcs can be inserted between explanations to show data- or control-flow. The value of VSL is that it enables a developer to better control a code. The developer can represent the structure via nested explanations, using arcs to indicate the flow of data and control. The explanations provide a ''second opinion'' about the code so that at any level, the developer can confirm that the code operates as it is intended to do. We believe that VSL enables a programmer to use in a computer language the same model-a hierarchy of components-that they use in their heads when they conceptualize systems

  17. 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.

  18. 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.

  19. 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.

  20. Structure of liquid lithium

    International Nuclear Information System (INIS)

    Neutron diffraction experiments, made at a steady-state reactor source, were used to study the structure of liquid 7Li at temperatures of 197, 452 and 595 deg. C. A careful data analysis procedure was undertaken in which specific issues taken into account include (i) the influence of Brillouin modes on the measured diffraction pattern at small scattering vectors, (ii) inelasticity corrections that are significant for light atom systems, such as lithium, and (iii) the effects caused by the diffractometer resolution function. Data sets taken for the same liquid temperature using different incident neutron energies yield ion-ion partial structure factors, SII(k), that are in agreement within the statistical errors. The SII(k) are compared with previous experimental results and with the results obtained from liquid state theory and molecular dynamics methods made using several different local pseudopotentials. Finally, the valence electron form factor, ρ(k), is estimated by combining SII(k) with x-ray diffraction data and the ion-valence electron partial structure factor, SIe(k), is calculated by combining SII(k) with the ρ(k) obtained from both experiment and theory. The results show that the extraction of ρ(k) and SIe(k) by a combination of neutron and x-ray diffraction methods is feasible in practice, but demonstrates a need for new x-ray diffraction experiments on liquid lithium

  1. 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.

  2. Structural Proteomics of Herpesviruses.

    Science.gov (United States)

    Leroy, Baptiste; Gillet, Laurent; Vanderplasschen, Alain; Wattiez, Ruddy

    2016-01-01

    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. PMID:26907323

  3. Advancing Autonomous Structural Health Monitoring

    OpenAIRE

    Grisso, Benjamin Luke

    2007-01-01

    The focus of this dissertation is aimed at advancing autonomous structural health monitoring. All the research is based on developing the impedance method for monitoring structural health. The impedance technique utilizes piezoelectric patches to interrogate structures of interested with high frequency excitations. These patches are bonded directly to the structure, so information about the health of the structure can be seen in the electrical impedance of the piezoelectric patch. However, tr...

  4. Structural classification of phosphate glasses

    International Nuclear Information System (INIS)

    A structural classification of phosphate glasses is proposed. Following types of phosphate glasses are distinguished: discontinuous polymeric structure glasses (phosphate and mixed chains and rings containing glasses), continuous spatial network structure glasses (ultraphosphate and mixed network glasses) and non-polymeric structure glasses (oxide-halide and halide glasses, stuffed with ortho- and pyrophosphate-like groups). Type of the structure determines in a considerable degree the relation between glass composition and properties. (author). 25 refs

  5. Structure and activation of rhodopsin

    OpenAIRE

    Zhou, X. Edward; Melcher, Karsten; Xu, H Eric

    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 ...

  6. 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...... to selectively manipulate and measure vestibular processing and perspectival structure. The hope is that this serves to indicate how interdisciplinary research on vestibular processing might advance our understanding of the structural features of conscious experience....

  7. Chapter V: Secondary landscape structure

    International Nuclear Information System (INIS)

    This chapter deals with the secondary landscape structure of the Slovak Republic. It consists of next subchapters: (1) Land use pattern; (2) Special landscape structures; (3) Real vegetation. The secondary landscape structure consists of the elements influenced by man, created or recreated. They represent material elements with a particular spatial delimitation in the landscape. Vegetation, above all forest vegetation, is the indispensable part of the secondary landscape structure. Special space was given to the historical landscape structure

  8. Recent results on structural control of an active precision structure

    Science.gov (United States)

    Chu, C. C.; Fanson, J. L.; Smith, R. S.

    1991-01-01

    This paper describes recent results in structural control of an active precision truss structure at JPL. The goal is to develop practical control methodology and to apply to active truss structures intended for high precision space-based optics applications. The active structure considered incorporates piezoelectric active members which apply control forces internal to the structure and thereby improve the structure's dimensional stability. Two approaches to structural control system design were investigated. The first approach uses only noncollocated measurements of acceleration at the location of a simulated optical component to achieve structural stabilization. The second approach is essentially the same as the first one except that a viscous damper was used in place of a truss member on the structure to improve the dampings of selected flexible modes. The corresponding experimental closed-loop results are presented in this paper.

  9. Radiation induced nano structures

    International Nuclear Information System (INIS)

    Full text: Nanometer-size silicon clusters have been attracting much attention due to their technological importance, in particular, as promising building blocks for nano electronic and nano photonic systems. Particularly, silicon wires are of great of interest since they have potential for use in one-dimensional quantum wire high-speed field effect transistors and light-emitting devices with extremely low power consumption. Carbon and metal nano structures are studied very intensely due to wide possible applications. Radiation material sciences have been dealing with sub-micron objects for a long time. Under interaction of high energy particles and ionizing radiation with solids by elastic and inelastic mechanisms, at first point defects are created, then they form clusters, column defects, disordered regions (amorphous colloids) and finally precipitates of another crystal phase in the matrix. Such irradiation induced evolution of structure defects and phase transformations was observed by X-diffraction techniques in dielectric crystals of quartz and corundum, which exist in and crystal modifications. If there is no polymorphism, like in alkali halide crystals, then due to radiolysis halogen atoms are evaporated from the surface that results in non-stoichiometry or accumulated in the pores formed by metal vacancies in the sub-surface layer. Nano-pores are created by intensive high energy particles irradiation at first chaotically and then they are ordered and in part filled by inert gas. It is well-known mechanism of radiation induced swelling and embrittlement of metals and alloys, which is undesirable for construction materials for nuclear reactors. Possible solution of this problem may come from nano-structured materials, where there is neither swelling nor embrittlement at gas absorption due to very low density of the structure, while strength keeps high. This review considers experimental observations of radiation induced nano-inclusions in insulating

  10. Error Location in Structural Dynamic Model of a Rocket Structure

    Science.gov (United States)

    Sundararajan, T.; Sam, C.

    2012-06-01

    Structural dynamic characteristics of the aerospace structures are essential to obtain the structural responses due to dynamic loads during its mission. The structural dynamic parameters of the aerospace structures are frequencies, associated mode shape and damping. Usually finite element (FE) model of the aerospace structures are generated to estimate the frequencies and the associated mode shape. These FE models are validated by modal survey/ground resonance tests to ensure its completeness and correctness. The modeling deficiencies, if any, in these FE models have to be corrected. This paper describes the method to locate the FE modeling errors using residual force method.

  11. Protein structural alphabets: beyond the secondary structure description : Structural alphabet : A review

    OpenAIRE

    De Brevern, Alexandre; Camproux, Anne-Claude; Hazout, Serge,; Etchebest, Catherine; Tufféry, Pierre

    2001-01-01

    The considerable increase of the protein structural database allows to cross the line from the classical secondary structure description of proteins. While still confronted with numerous problems, defining structural alphabets is an emerging concept in the field of protein structure analysis. It is an attempt to objectively classify the whole set of conformations occurring in protein structures described by small overlapping fragments. It is expected to lead to a better understanding of prote...

  12. Structural Optimization with Reliability Constraints

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    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 is...

  13. 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.

  14. 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

  15. 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

  16. 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).

  17. Strictly convergent analytic structures

    OpenAIRE

    Cluckers, Raf; Lipshitz, Leonard

    2013-01-01

    We give conclusive answers to some questions about definability in analytic languages that arose shortly after the work by Denef and van den Dries, [DD], on $p$-adic subanalytic sets, and we continue the study of non-archimedean fields with analytic structure of [LR3], [CLR1] and [CL1]. We show that the language $L_K$ consisting of the language of valued fields together with all strictly convergent power series over a complete, rank one valued field $K$ can be expanded, in a definitial way, t...

  18. Structured light camera calibration

    Science.gov (United States)

    Garbat, P.; Skarbek, W.; Tomaszewski, M.

    2013-03-01

    Structured light camera which is being designed with the joined effort of Institute of Radioelectronics and Institute of Optoelectronics (both being large units of the Warsaw University of Technology within the Faculty of Electronics and Information Technology) combines various hardware and software contemporary technologies. In hardware it is integration of a high speed stripe projector and a stripe camera together with a standard high definition video camera. In software it is supported by sophisticated calibration techniques which enable development of advanced application such as real time 3D viewer of moving objects with the free viewpoint or 3D modeller for still objects.

  19. Structured Stochastic Linear Bandits

    OpenAIRE

    Johnson, Nicholas; Sivakumar, Vidyashankar; Banerjee, Arindam

    2016-01-01

    The stochastic linear bandit problem proceeds in rounds where at each round the algorithm selects a vector from a decision set after which it receives a noisy linear loss parameterized by an unknown vector. The goal in such a problem is to minimize the (pseudo) regret which is the difference between the total expected loss of the algorithm and the total expected loss of the best fixed vector in hindsight. In this paper, we consider settings where the unknown parameter has structure, e.g., spa...

  20. Structure of the Universe

    OpenAIRE

    Haubold, H. J.; Mathai, A.M.

    1996-01-01

    An introductory account is given of the understanding of the structure of the universe. At present the most plausible theory of the origin of the universe is that it formed from the explosion of an extremely hot and dense fireball several billion years ago. During the first few seconds after the big bang, the energy density was so great that only fundamental particles (leptons, quarks, gauge bosons) existed. As the universe cooled and expanded after the big bang, nuclei and atoms formed and c...

  1. Structural Logical Relations

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Sarnat, Jeffrey

    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, 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...

  2. Modeling solar magnetic structures

    Science.gov (United States)

    Low, B. C.

    1985-01-01

    Some ideas in the theoretical study of force-free magnetic fields and magnetostatic fields, which are relevant to the effort of using magnetograph data as inputs to model the quasi-static, large-scale magnetic structures in the solar atmosphere are discussed. Basic physical principles will be emphasized. An attempt will be made to assess what we may learn, physically, from the models based on these ideas. There is prospect for learning useful physics and this ought to be an incentive for intensifying the efforts to improve vector magnetograph technology and to solve the basic radiative-transfer problems encountered in the interpretation of magnetograph raw data.

  3. 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

  4. Magnetic Structure of Erbium

    DEFF Research Database (Denmark)

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

    1986-01-01

    We present a synchrotron x-ray scattering study of the magnetic phases of erbium. In addition to the magnetic scattering located at the fundamental wave vector τm we also observe scattering from magnetoelastically induced charge modulations at the fundamental wave vector, at twice the fundamental......, 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 of...

  5. Structure of polysaccharide antibiotics

    International Nuclear Information System (INIS)

    Study of the structure of antibiotics having two or several sugars in their molecule. One may distinguish: the polysaccharide antibiotics themselves, made up of two or several sugars either with or without nitrogen, such as streptomycin, neomycins, paromomycine, kanamycin, chalcomycin; the hetero-polysaccharide antibiotics made up of one saccharide part linked to an aglycone of various type through a glucoside: macrolide, pigment, pyrimidine purine. Amongst these latter are: erythromycin, magnamycin, spiramycin, oleandomycin, cinerubin and amicetin. The sugars can either play a direct role in biochemical reactions or act as a dissolving agent, as far as the anti-microbe power of these antibiotics is concerned. (author)

  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. 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.

  8. Structures in entanglement dynamics

    International Nuclear Information System (INIS)

    Understanding the dynamics of entanglement that is exhibited by a quantum system constitutes a major step in the venture to harvest this quantum effect in potential applications, and to elaborate the role that entanglement plays in real world settings. Interesting dynamics include collective coherent driving and general decoherence processes. Without resorting to the phenomenological treatment of specific examples, we present general features of the structure underlying the dynamics of entanglement. Starting from low dimensional systems where algebraic properties of some entanglement monotones allow for an ''entanglement equation of motion'' we continue, using topological and measure theoretic approaches, to typical behaviour exhibited in the thermodynamic limit

  9. 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

  10. Wind Turbine Structural Dynamics

    Science.gov (United States)

    Miller, D. R. (Editor)

    1978-01-01

    A workshop on wind turbine structural dynamics was held to review and document current United States work on the dynamic behavior of large wind turbines, primarily of the horizontal-axis type, and to identify and discuss other wind turbine configurations that may have lower cost and weight. Information was exchanged on the following topics: (1) Methods for calculating dynamic loads; (2) Aeroelasticity stability (3) Wind loads, both steady and transient; (4) Critical design conditions; (5) Drive train dynamics; and (6) Behavior of operating wind turbines.

  11. 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

  12. 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.

  13. Advanced structural wind engineering

    CERN Document Server

    Kareem, Ahsan

    2013-01-01

    This book serves as a textbook for advanced courses as it introduces state-of-the-art information and the latest research results on diverse problems in the structural wind engineering field. The topics include wind climates, design wind speed estimation, bluff body aerodynamics and applications, wind-induced building responses, wind, gust factor approach, wind loads on components and cladding, debris impacts, wind loading codes and standards, computational tools and computational fluid dynamics techniques, habitability to building vibrations, damping in buildings, and suppression of wind-induced vibrations. Graduate students and expert engineers will find the book especially interesting and relevant to their research and work.

  14. Neutron structural biology

    International Nuclear Information System (INIS)

    Neutron structural biology will be one of the most important fields in the life sciences which will interest human beings in the 21st century because neutrons can provide not only the position of hydrogen atoms in biological macromolecules but also the dynamic molecular motion of hydrogen atoms and water molecules. However, there are only a few examples experimentally determined at present because of the lack of neutron source intensity. Next generation neutron source scheduled in JAERI (Performance of which is 100 times better than that of JRR-3M) opens the life science of the 21st century. (author)

  15. Nuclear structure theory

    International Nuclear Information System (INIS)

    This report summarizes progress during the past year in the following areas of research: Pion charge exchange reactions, including a theory of the contribution of pion absorption and correlated double scattering to double charge exchange, new coupled channel calculations for single and double charge exchange from 14C. Nuclear inelastic scattering, using quark models to calculate nuclear structure functions, and test for sensitivity to the substructure of nucleons in nuclei. Fluctuation-free statistical spectroscopy including the theory and computer programs for interacting-particle densities, spin cutoff factors, occupancies, strength sums, and other expectation values. Proposed research for the coming year in each area is presented

  16. Aspects of hadronic structure

    International Nuclear Information System (INIS)

    An overview of the current phenomenological models of hadron structure, whose theoretical basis is the Quantum Chromodynamics (QCD), is presented. A short introduction to the QCD permits to focalize the relevant properties which are attached to those models. Following, bag-like models (in particular, MIT bag and chiral extensions) and potential-like models among them the Karl and Isgur non-relativistic model and a semi-relativistic model, free of the Klein paradox, with equal scalar-vetorial mixture of confinement potential are shortly studied. Enphasis is given to the baryons, treated, basically, as three-quarks systems. (L.C.)

  17. Hydrogen bonded supramolecular structures

    CERN Document Server

    Li, Zhanting

    2015-01-01

    This book covers the advances in the studies of hydrogen-bonding-driven supramolecular systems  made over the past decade. It is divided into four parts, with the first introducing the basics of hydrogen bonding and important hydrogen bonding patterns in solution as well as in the solid state. The second part covers molecular recognition and supramolecular structures driven by hydrogen bonding. The third part introduces the formation of hollow and giant macrocycles directed by hydrogen bonding, while the last part summarizes hydrogen bonded supramolecular polymers. This book is designed to b

  18. Structural integrity in aircraft.

    Science.gov (United States)

    Hardrath, H. F.

    1973-01-01

    The paper reviews briefly the current design philosophies for achieving long, efficient, and reliable service in aircraft structures. The strengths and weaknesses of these design philosophies and their demonstrated records of success are discussed. The state of the art has not been developed to the point where designing can be done without major test inspection and maintenance programs. A broad program of research is proposed through which a viable computerized design scheme will be provided during the next decade. The program will organize and correlate existing knowledge on fatigue and fracture behavior, identify gaps in this knowledge, and guide specific research to upgrade design capabilities.

  19. 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...

  20. Structural alphabets for protein structure classification: a comparison study.

    Science.gov (United States)

    Le, Quan; Pollastri, Gianluca; Koehl, Patrice

    2009-03-27

    Finding structural similarities between proteins often helps reveal shared functionality, which otherwise might not be detected by native sequence information alone. Such similarity is usually detected and quantified by protein structure alignment. Determining the optimal alignment between two protein structures, however, remains a hard problem. An alternative approach is to approximate each three-dimensional protein structure using a sequence of motifs derived from a structural alphabet. Using this approach, structure comparison is performed by comparing the corresponding motif sequences or structural sequences. In this article, we measure the performance of such alphabets in the context of the protein structure classification problem. We consider both local and global structural sequences. Each letter of a local structural sequence corresponds to the best matching fragment to the corresponding local segment of the protein structure. The global structural sequence is designed to generate the best possible complete chain that matches the full protein structure. We use an alphabet of 20 letters, corresponding to a library of 20 motifs or protein fragments having four residues. We show that the global structural sequences approximate well the native structures of proteins, with an average coordinate root mean square of 0.69 A over 2225 test proteins. The approximation is best for all alpha-proteins, while relatively poorer for all beta-proteins. We then test the performance of four different sequence representations of proteins (their native sequence, the sequence of their secondary-structure elements, and the local and global structural sequences based on our fragment library) with different classifiers in their ability to classify proteins that belong to five distinct folds of CATH. Without surprise, the primary sequence alone performs poorly as a structure classifier. We show that addition of either secondary-structure information or local information from the

  1. 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.

  2. 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.

  3. Integrated materials–structural models

    DEFF Research Database (Denmark)

    Stang, Henrik; Geiker, Mette Rica

    2008-01-01

    structural modelling and materials concepts will both operational in both identifying important research issues and in answering the ‘real’ needs of society. Integrated materials-structural models will allow synergy to develop between materials and structural research. On one side the structural modelling...... should define a framework in which materials research results eventually should fit in and on the other side the materials research should define needs and capabilities in structural modelling. Integrated materials-structural models of a general nature are almost non-existent in the field of cement based...

  4. 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

  5. Probabilistic structural analysis methods of hot engine structures

    Science.gov (United States)

    Chamis, C. C.; Hopkins, D. A.

    1989-01-01

    Development of probabilistic structural analysis methods for hot engine structures is a major activity at Lewis Research Center. Recent activities have focused on extending the methods to include the combined uncertainties in several factors on structural response. This paper briefly describes recent progress on composite load spectra models, probabilistic finite element structural analysis, and probabilistic strength degradation modeling. Progress is described in terms of fundamental concepts, computer code development, and representative numerical results.

  6. 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...

  7. Lagrange structure and quantization

    International Nuclear Information System (INIS)

    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

  8. 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.

  9. Structural Colors of Birds

    Science.gov (United States)

    Hall, Cecilia; Dushkina, Natalia

    2016-03-01

    Structural colors create iridescent colors in bird feathers. The goal is to understand why structural colors act the way they do in certain situations. The research conducted over the course of the fall semester was to understand the optical phenomenon producing colors in individual barbules. Through the use of a polarizing optical microscope, certain hypotheses were built to explain certain phenomenon. Using a dark field illumination involving light acting at wide angles in microscopy, the barbules were not affected by polarization. So it can be suggested that the barbules have certain characteristics, possibly internal, which prevents wide-angle polarization. More recently, it was found that the barbules, when stacked upon one another, create a discoloration at the cross over point. It can be suggested that the barbules act as thin films and create a situation of thin film interference. More data will be taken using the Scanning Electron Microscope as well as getting cross sectional data to help understand the internal characteristics of the barbules. From the support of the Neimeyer-Hodgson Grant, Chris Stull, and Millersville University of Pennsylvania.

  10. Solar Sector Structure

    CERN Document Server

    Hudson, Hugh; Hannah, Iain

    2015-01-01

    The interplanetary magnetic field near has a characteristic "sector" structure that reflects its polarity relative to the solar direction. Typically we observe large-scale coherence in these directions, with two or four "away" or "towards" sectors per solar rotation, from any platform in deep space and near the ecliptic plane. In a simple picture, this morphology simply reflects the idea that the sources of the interplanetary field lie mainly in or near the Sun, and that the solar-wind flow enforces a radial component in this field. Although defined strictly via the interplanetary field near one AU, recent evidence confirms that this pattern also appears clearly at the level of the photosphere, with signatures including not only the large-scale structures (e.g., the streamers) but also highly concentrated fields such as those found in sunspots and even solar flares. This association with small-scale fields strengthens at the Hale sector boundary, defining the Hale boundary as the one for which the polarity sw...

  11. 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. PMID:25982316

  12. Fuel assembly supporting structure

    International Nuclear Information System (INIS)

    For use in forming the core of a pressurized-water reactor, a fuel assembly supporting structure for holding a bundle of interspaced fuel rods, is formed by interspaced end pieces having holes in which the end portions of control rod guide tubes are inserted, fuel rod spacer grids being positioned by these guide tubes between the end pieces. The end pieces are fastened to the end portions of the guide tubes, to integrate the supporting structure, and in the case of at least one of the end pieces, this is done by means which releases that end piece from the guide tubes when the end pieces receive an abnormal thrust force directed towards each other and which would otherwise place the guide tubes under a compressive stress that would cause them to buckle. The spacer grids normally hold the fuel rods interspaced by distances determined by nuclear physics, and buckling of the control rod guide tubes can distort the fuel rod spacer grids with consequent dearrangement of the fuel rod interspacing. A sudden loss of pressure in a pressurized-water reactor pressure vessel can result in the pressurized coolant in the vessel discharging from the vessel at such high velocity as to result in the abnormal thrust force on the end pieces of each fuel assembly, which could cause buckling of the control rod guide tubes when the end pieces are fixed to them in the normal rigid and unyielding manner

  13. (t, i, f) -Neutrosophic Structures & Neutrosophic Structures (Revisited)

    OpenAIRE

    Florentin Smarandache

    2015-01-01

    This paper is an improvement of our paper “(t, i, f)-Neutrosophic Structures”, where we introduced for the first time a new type of structures, called (t, i, f)-Neutrosophic Structures, presented from a neutrosophic logic perspective, and we showed particular cases of such structures in geometry and in algebra

  14. Combinatorics of $\\gamma$-structures

    CERN Document Server

    Han, Hillary S W

    2011-01-01

    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 $\\gamma$, where composition means concatenation and nesting of such blocks. Our main result is the derivation of the generating function of $\\gamma$-structures via symbolic enumeration. $\\gamma$-structures are constructed via $\\gamma$-matchings. We compute an algebraic equation for the generating function of these matchings and prove that it is the unique solution. For $\\gamma=1$ and $\\gamma=2$ we compute the Puiseux-expansion of this power series at its unique, dominant singularity. This allows us to derive simple asymptotic formulas for the number of 1-structures and 2-structures.

  15. Hidden structures in quantum mechanics

    OpenAIRE

    Dzhunushaliev, Vladimir

    2008-01-01

    It is shown that some operators in quantum mechanics have hidden structures that are unobservable in principle. These structures are based on a supersymmetric decomposition of the momentum operator, and a nonassociative decomposition of the spin operator.

  16. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    The collection of abstracts on selected topics in nuclear structure are given. Special attention pays to collective excitations and high-spin states of nuclei, giant resonance structure, nuclear reaction mechanisms and so on

  17. Sub-structures in hadrons and proton structure functions

    Science.gov (United States)

    Arash, Firooz; Khorramian, Ali N.

    2001-04-01

    We calculate the partonic structure of constituent quark in the Next-to-Leading Order. Using a convolution method, Structure function of proton is presented. While the constituent quark structure is generated purely perturbatively and accounts for the most part of the hadronic structure, there is a few percent contributions coming from the nonperturbative sector in the hadronic structure. This contribution plays the key role in explaining the SU(2) symmetry breaking of the nucleon sea and the observed violation of Gottfried sum rule. Excellent agreement with data in a wide range of x = [10 -6, 1] and Q2 = [0.5, 5000] GeV2 for Fp2 is reached.

  18. Market Timing and Capital Structure

    OpenAIRE

    Jeffrey A. Wurgler; Baker, Malcolm P.

    2001-01-01

    It is well known that firms tend to raise equity when their market values are high relative to book and past market values. We document that the resulting effects on capital structure are very persistent. As a consequence, current capital structure is strongly related to past market valuations. The results are difficult to explain within traditional theories of capital structure and suggest that capital structure is the cumulative outcome of past attempts to time the equity market.

  19. Approaches to Automatic Text Structuring

    OpenAIRE

    Erbs, Nicolai

    2015-01-01

    Structured text helps readers to better understand the content of documents. In classic newspaper texts or books, some structure already exists. In the Web 2.0, the amount of textual data, especially user-generated data, has increased dramatically. As a result, there exists a large amount of textual data which lacks structure, thus making it more difficult to understand. In this thesis, we will explore techniques for automatic text structuring to help readers to fulfill their information need...

  20. Lattice Structures for Attractors I

    OpenAIRE

    Kalies, William D.; Mischaikow, Konstantin; Vandervorst, Robert C. A. M.

    2013-01-01

    We describe the basic lattice structures of attractors and repellers in dynamical systems. The structure of distributive lattices allows for an algebraic treatment of gradient-like dynamics in general dynamical systems, both invertible and noninvertible. We separate those properties which rely solely on algebraic structures from those that require some topological arguments, in order to lay a foundation for the development of algorithms to manipulate these structures computationally.

  1. Marine Structures with Heavy Overtopping

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter

    2000-01-01

    An investigation of wave overtopping of marine structures is described. Focus is put on structures with realtively low crest levels and various slope layouts subjected to non-breaking waves. Influence of slope draught and angle is investigated.......An investigation of wave overtopping of marine structures is described. Focus is put on structures with realtively low crest levels and various slope layouts subjected to non-breaking waves. Influence of slope draught and angle is investigated....

  2. Kinematic Analysis of Tensegrity Structures

    OpenAIRE

    Whittier, William Brooks

    2002-01-01

    Tensegrity structures consist of isolated compression members (rigid bars) suspended by a continuous network of tension members (cables). Tensegrity structures can be used as variable geometry truss (VGT) mechanisms by actuating links to change their length. This paper will present a new method of position finding for tensegrity structures that can be used for actuation as VGT mechanisms. Tensegrity structures are difficult to understand and mathematically model. This difficulty is p...

  3. Spacetime structure and Quantum physics

    OpenAIRE

    Ho, Vu B

    1993-01-01

    A description of electromagnetism as four-dimensional spacetime structure leads to the dynamics of a charged particle being determined only by the four-vector potential and the existence of an electromagnetic field depending on the topological structure of the background spacetime. When the spacetime structure of electromagnetism is complex it is possible to connect spacetime structure and quantum physics via the method of path integration. (This paper is a consequence of an attempt to incorp...

  4. Magic Numbers in Protein Structures

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker; Bohr, Henrik

    1996-01-01

    domains. We have performed a statistical analysis of available protein structures and found agreement with the predicted preferred abundances. Furthermore, a connection between sequence information and fold classes is established in terms of hinge forces between the structural elements.......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...

  5. Risk, Resources and Structures

    DEFF Research Database (Denmark)

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

    2012-01-01

    risk cost component presented in this article, whose existence has previously been argued in the risk literature, has been documented in a single factorial experiment with a unique simulation device named Risky Business. Through our experiments, we have shown that the first response of subjects exposed......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. The...

  6. Structure in radio galaxies

    International Nuclear Information System (INIS)

    It is shown that radio jets are a rather common phenomenon in radio galaxies. Jets can be disguised as trails in head-tail sources, bridges in double sources or simply remain undetected because of lack of resolution and sensitivity. It is natural to associate these jets with the channels which had previously been suggested to supply energy to the extended radio lobes. The observations of optical emission suggest that a continuous non-thermal spectrum extending from 109 to 1015 Hz is a common property of jets. Because significant amounts of interstellar matter are also observed in each of the galaxies surveyed it seems that models for jets which involve an interaction with this medium may be most appropriate. New information about the overall structure of extended radio sources has been obtained from the detailed multifrequency study with the WSRT. (Auth.)

  7. Theory of spiral structure

    International Nuclear Information System (INIS)

    The density wave theory of galactic spirals has now developed into a form suitable for consideration by experts in Applied Mechanics. On the one hand, comparison of theoretical deductions with observational data has convinced astrophysicists of the validity of the basic physical picture and the calculated results. On the other hand, the dynamical problems of a stellar system, such as those concerning the origin of spiral structure in galaxies, have not been completely solved. This paper reviews the current status of such developments, including a brief summary of comparison with observations. A particularly important mechanism, currently called the mechanism of energy exchange, is described in some detail. The mathematical problems and the physical processes involved are similar to those occurring in certain instability mechanisms in the 'magnetic bottle' designed for plasma containment. Speculations are given on the future developments of the theory and on observational programs. (Auth.)

  8. The proton structure

    International Nuclear Information System (INIS)

    HERA (Hadron Elektron Ring Anlage) has been operating since 1992, about 400 physicists coming from 12 countries take part in the experiment program. This particle accelerator allows very high energy collisions between electrons and protons, so it can be considered as a super electronic microscope used to study the proton structure and particularly the quark-gluon plasma inside the proton. Whenever an energetic electron collides with a proton, the electron emits an intermediate particle (either a photon or a vector boson) that interacts with the proton components. The bigger the impulse transfer during the collision, the better the spatial resolution becomes. The energies of the proton or electron beams delivered at HERA are optimized so that the spatial resolution reaches 5.10-19 meters, which means that we can study matter on distances 5 times shorter than the weak interaction range. (A.C.)

  9. Causality and Composite Structure

    CERN Document Server

    Joglekar, Satish D

    2007-01-01

    We study the question of whether a composite structure of elementary particles, with a length scale $1/\\Lambda$, can leave observable effects of non-locality and causality violation at higher energies (but $\\lesssim \\Lambda$). We formulate a model-independent approach based on Bogoliubov-Shirkov formulation of causality. We analyze the relation between the fundamental theory (of finer constituents) and the derived theory (of composite particles). We assume that the fundamental theory is causal and formulate a condition which must be fulfilled for the derived theory to be causal. We analyze the condition and exhibit possibilities which fulfil and which violate the condition. We make comments on how causality violating amplitudes can arise.

  10. Nucleon Spin Structure: Experiment

    Science.gov (United States)

    Miller, Andy

    2003-04-01

    The experimental study of nucleon spin structure is at a transitional stage. Deeply inelastic scattering of leptons has revealed much about quark helicity distributions, and is approaching the limits of what is possible with present experimental facilities. The latest results from semi-inclusive measurements at HERMES will be presented. Precise new complementary data are expected soon from W production at RHIC-Spin. The gluon polarization will also be measured soon at COMPASS and RHIC. Meanwhile, single-spin asymmetries that promise to provide access to the unknown transversity distribution have been observed, and will be discussed. Based on these signals, the first measurements of transversity are underway. Finally, single spin asymmetries have also been recently observed in hard exclusive processes such as deeply virtual Compton scattering. These signals have the potential to provide a new window on both orbital angular momentum of partons, and on correlations between their longitudinal momentum and transverse position.

  11. High energy nuclear structures

    International Nuclear Information System (INIS)

    Nuclear field theory has been applied to study nuclear matter as well as finite nuclei. Within the mean field approximation the known bulk properties of nuclei such as binding energy, density, and compressibility are well reproduced. Charge and matter distributions of closed shell nuclei are in good agreement with experimental results, so are rms radii and single-particle energy levels. In addition to the description of known nuclear structure the field theoretical approach may reveal entirely new nuclear phenomena, based on the explicite treatment of mesonic degrees of freedom. The existence of such abnormal nuclear states was proposed by Lee and Wick employing the sigma-model Lagrangian. There the non-linearity of the meson field equations allows for soliton solutions in the presence of nucleons, in particular the sigma-field may exhibit a kink. Some of these solutions are considered

  12. 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 ...

  13. Evolution of energy structures

    International Nuclear Information System (INIS)

    Because of the big inertia and long time constants of energy systems, their long-time behaviour is mainly determined by their present day state and by the trends of their recent evolution. For this reason, it is of prime importance to foresee the evolution of the different energy production sources which may play an important role in the future. A status of the world energy consumption and production is made first using the energy statistics of the IEA. Then, using the trends observed since 1973, the consequences of a simple extrapolation of these trends is examined. Finally, the scenarios of forecasting of energy structures, like those supplied by the International institute for applied systems analysis (IIASA) are discussed. (J.S.)

  14. 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.

  15. Internal Cluster Structure

    CERN Document Server

    Bartelmann, Matthias; Meneghetti, Massimo; Schmidt, Robert

    2013-01-01

    The core structure of galaxy clusters is fundamentally important. Even though self-gravitating systems have no stable equilibrium state due to their negative heat capacity, numerical simulations find density profiles which are universal in the sense that they are fairly flat within a scale radius and gradually steepen farther outward, asymptotically approaching a logarithmic slope of $\\approx-3$ near the virial radius. We argue that the reason for the formation of this profile is not satisfactorily understood. The ratio between the virial radius and the scale radius, the so-called concentration, is found in simulations to be closely related to the mass and the redshift and low for cluster-sized haloes, but observed to be substantially higher at least in a subset of observed clusters. Haloes formed from cold dark matter should furthermore be richly substructured. We review theoretical and observational aspects of cluster cores here, discuss modifications by baryonic physics and observables that can provide bet...

  16. Compact pentaquark structures

    CERN Document Server

    Santopinto, Elena

    2016-01-01

    We study the possibility that at least one of the two pentaquark structures recently reported by LHCb can be described as a compact pentaquark state, and we give predictions for new channels that can be studied by the experimentalists if this hypothesis is correct. We use very general arguments dictated by symmetry considerations, in order to describe the pentaquark states within a group theory approach. A complete classification of all possible states and quantum numbers, that can be useful both to the experimentalists, for new finding, or to theoretical model builders, are given, without the introduction of any particular dynamical model. Some prediction are finally given using a Guersey-Radicati inspired mass formula. We reproduce the mass and the quantum numbers of the lightest pentaquark state reported by LHCb ( 3/2^-), with a parameter free mass formula, fixed on the well established baryons. We predict others pentaquark resonances (giving their masses, and suggesting possible decay channels) which belo...

  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. Erosion below submarine structures

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, S.; Asp Hansen, E.

    1997-07-01

    A numerical model for the development of bed dominated scour around sub-sea structures is presented. The hydrodynamic part of the model is based on a modified potential flow theory. The purpose of the present study has been to develop relatively simple models, yet complex enough to capture the main physics that can be used as engineering tools. An overview of scour phenomena and the basic problems of scour in steady current flow is presented. A hydrodynamic model for horseshoe vortex is presented, as well as a model for the bed transport, and examples are given. The scour in oscillatory flow and a curvilinear model for suspended sediment calculations are described. An advection-diffusion model (formulated in a curvilinear stretched coordinate system) has been developed and is described in an article which has been submitted for publication, a copy of the article is enclosed in Appendix E of the report. (EG)

  19. High temperature structural silicides

    International Nuclear Information System (INIS)

    Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi2-based materials, which are borderline ceramic-intermetallic compounds. MoSi2 single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi2 possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi2-Si3N4 composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi2-based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing

  20. Crystal structure of dimethomorph

    Directory of Open Access Journals (Sweden)

    Gihaeng Kang

    2015-09-01

    Full Text Available In the title compound, C21H22ClNO4 [systematic name: (E-3-(4-chlorophenyl-3-(3,4-dimethoxyphenyl-1-(morpholin-4-ylprop-2-en-1-one], which is the morpholine fungicide dimethomorph, the dihedral angles between the mean planes of the central chlorophenyl and the terminal benzene and morpholine (r.m.s. deviation = 0.2233 Å rings are 71.74 (6 and 63.65 (7°, respectively. In the crystal, molecules are linked via C—H...O hydrogen bonds and weak Cl...π interactions [3.8539 (11 Å], forming a three-dimensional structure.

  1. 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...

  2. Structural genomics of membrane proteins

    OpenAIRE

    Walian, Peter; Cross, Timothy A.; Jap, Bing K.

    2004-01-01

    Improvements in the fields of membrane-protein molecular biology and biochemistry, technical advances in structural data collection and processing, and the availability of numerous sequenced genomes have paved the way for membrane-protein structural genomics efforts. There has been significant recent progress, but various issues essential for high-throughput membrane-protein structure determination remain to be resolved.

  3. 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

  4. Solution structure of human prolactin

    DEFF Research Database (Denmark)

    Teilum, Kaare; Hoch, Jeffrey C; Goffin, Vincent; Kinet, Sandrina; Martial, Joseph A; Kragelund, Birthe B

    2005-01-01

    We report the solution structure of human prolactin determined by NMR spectroscopy. Our result is a significant improvement over a previous structure in terms of number and distribution of distance restraints, regularity of secondary structure, and potential energy. More significantly, the...

  5. Characterization of Injection Molded Structures

    DEFF Research Database (Denmark)

    Sun, Ling; Søgaard, Emil; Andersen, Nis Korsgaard;

    and limitations. Therefore, it would be difficult to characterize complex, especially hierarchical structures by using only one method. Here we present a combined optical microscopy, scanning electron microscopy (SEM), and scanning probe microscopy study on injection molded structures. These...... understand structure-properties relationship of the injection molded polymer samples. These results are very important in optimizing injection molding parameters....

  6. 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.

  7. Structure of cellulose acetobacter xylinum

    International Nuclear Information System (INIS)

    The data are presented on optimization of cellulose synthesis by Acetobacter xylinum (strain VKM V-880) and the structural characteristics of A. xylinum cellulose gel film synthesized during static cultivation. The structural changes caused by the removal of water from gel films are established and the structural organization of macromolecular chains in cellulose A. xylinum is studied

  8. 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.

  9. RNA Structural Alignments, Part I

    DEFF Research Database (Denmark)

    Havgaard, Jakob Hull; Gorodkin, Jan

    Simultaneous alignment and secondary structure prediction of RNA sequences is often referred to as "RNA structural alignment." A class of the methods for structural alignment is based on the principles proposed by Sankoff more than 25 years ago. The Sankoff algorithm simultaneously folds and aligns...

  10. Stellar Flares and Coronal Structure

    OpenAIRE

    Guedel, M.

    2003-01-01

    Coronal structure and coronal heating are intimately related in magnetically active stars. Coronal structure is commonly inferred from radio interferometry and from eclipse and rotational modulation studies. We discuss to what extent flares may be responsible for coronal structure and global observable properties in magnetically active stars.

  11. Robustness Evaluation of Timber Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

    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...

  12. 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.

  13. ITER containment structures

    International Nuclear Information System (INIS)

    This document describes the results and recommendations of the Containment Structures Design Unit (CSDU) on the containment structures for ITER, made in the context of the Conceptual Design Phase. The document describes the following subsystems: (1) the primary vacuum vessel (VV), (2) the attaching locks (AL) of the invessel components, (3) the plasma passive and active stabilizers, (4) the cryostat vessel, and (5) the machine gravity supports. Although for most components reference designs were selected, for some of these alternative design options were described, because unresolved problems necessitate further research and development. Conclusions and future needs are summarized for each of the above subsystems: (1) a reference VV design was selected, while most critical VV future needs are the feasibility studies of manufacturing, assembly, and the repair/disassembly/reassembly by remote handling. Alternative, thin-wall options appear attractive and should be studied further during the Engineering Design Activities; (2) no reference design solution was selected for the AL system, as AL design requirements are extremely difficult and internally contradictory, while there is no existing tokamak precedent, but instead, five different approaches will be further researched early in the Engineering Design Phase; (3) significant progress is reported on passive loops, for which the ''twin-loops'' concept is ready to be advanced into the Engineering Design Phase, and on active coils, where a new coil positioning prevents interference with the blanket removal paths, and the current joints are located in a secondary vacuum or in the atmosphere of the reactor hall, repairable by remote handling; (4) a full metallic welded cryostat design with increased toroidal resistance was chosen, but with a design based on concrete with a thin inner metallic liner as a back-up in case detailed nuclear shielding requirements would force the cryostat to act as biological shield; (5) out

  14. Structural analysis system THANKS

    International Nuclear Information System (INIS)

    The analytical codes THANKS (Three Dimensional Analysis of NIPPON KOKAN Systems) V-1, THANKS V-2, and THANKS V-3 were developed to analyze the structures having complicated configuration, to simulate the actual phenomena including elastoplastic property, creep, large deformation and dynamic behavior, and to analyze thermal and hydraulic characteristics. These codes are supported with the development of pre-processor PRE-THANKS and post-processor POST-THANKS. The special features of this code system are as follows: 1) it is possible to analyze the strength of three dimensional structures having any complex configuration and to calculate the large scale problems with 160,000 freedom, 2) it is possible to treat the broad range of linear and nonlinear problems of both static and dynamic and thermal conduction, 3) the calculating time is shortened, 4) the program consists of modules, therefore the partial improvement is simple, and the addition of new functions is easy, 5) the graphic display utilizing cathode ray tubes (CRT) is available, and 6) the high efficiency and the reduction of labor are planned. The hardwares of THANKS system consist of a computer IBM S370/168, a card reader, magnetic discs, a printer, a graphic display and a plotter, and PRE-THANKS, THANKS V-1 THANKS V-2 THANKS V-3 and POST-THANKS are included in this computer system. PRE-THANKS has the functions such as the input of two and three dimensional mesh configurations, the production of mesh files, and the display with a CRT. POST-THANKS has the function displaying stress contours, stress distribution, change of stress in course of time and deformation on CRT or drawing them utilizing a plotter. (Nakai, Y.)

  15. 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

  16. Libavaida sugrusida uherles ja vurles kehus* / Maria Ulfsak-Šeripova

    Index Scriptorium Estoniae

    Ulfsak-Šeripova, Maria, 1981-

    2010-01-01

    Tim Burtoni filmist "Alice Imedemaal" (USA 2010), stsenarist Linda Woolverton, peaosades Mia Wasikowska, Johnny Depp. Lisaks kaks arvamust "3D poolt", autor Mann Jõgeda ja "3D vastu", autor Margit Tõnson

  17. A parametric study of structure-soil-structure interactions (SSSI) effects for typical NPP structures

    International Nuclear Information System (INIS)

    This paper presents parametric study results of the dynamic structure-soil-structure interaction (SSSI) effects for typical nuclear power plant structures built in Korea. Three building structures and three site conditions are considered in the study. Distance ratio and mass ratio are considered as critical parameters. As a result, it is found that the effects of SSSI phenomenon are more significant for lighter structures with small distance ratios, and generally this phenomenon can be ignored for buildings with large distance ratios or for buildings founded on stiff stratum. However, if dynamic characteristics of the structure are similar to the adjacent structure, the structural response could be influenced by SSSI effects even through the buildings are on a stiff site. Therefore, the effects of SSSI should be considered for this condition. (author). 5 refs., 12 figs., 2 tabs

  18. System Reliability of Timber Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

    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......-called statical system effect, will usually increase the reliability of the whole structural system and give an extra safety margin compared to the deterministic code results. The aim of this fact sheet is to outline the relationship between system reliability and the characteristics ductility and redundancy....

  19. 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.

  20. Computational Methods For Composite Structures

    Science.gov (United States)

    Chamis, Christos C.

    1988-01-01

    Selected methods of computation for simulation of mechanical behavior of fiber/matrix composite materials described in report. For each method, report describes significance of behavior to be simulated, procedure for simulation, and representative results. Following applications discussed: effects of progressive degradation of interply layers on responses of composite structures, dynamic responses of notched and unnotched specimens, interlaminar fracture toughness, progressive fracture, thermal distortions of sandwich composite structure, and metal-matrix composite structures for use at high temperatures. Methods demonstrate effectiveness of computational simulation as applied to complex composite structures in general and aerospace-propulsion structural components in particular.

  1. Hydrodynamic loading of tensegrity structures

    Science.gov (United States)

    Wroldsen, Anders S.; Johansen, Vegar; Skelton, Robert E.; Sørensen, Asgeir J.

    2006-03-01

    This paper introduces hydrodynamic loads for tensegrity structures, to examine their behavior in marine environments. Wave compliant structures are of general interest when considering large marine structures, and we are motivated by the aquaculture industry where new concepts are investigated in order to make offshore installations for seafood production. This paper adds to the existing models and software simulations of tensegrity structures exposed to environmental loading from waves and current. A number of simulations are run to show behavior of the structure as a function of pretension level and string stiffness for a given loading condition.

  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. A Molecular–Structure Hypothesis

    Science.gov (United States)

    Boeyens, Jan C. A.

    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 occurs in three dimensions, cannot be simulated by quantum-chemical computation. PMID:21151437

  4. Structural proteomics by NMR spectroscopy.

    Science.gov (United States)

    Shin, Joon; Lee, Woonghee; Lee, Weontae

    2008-08-01

    Structural proteomics is one of the powerful research areas in the postgenomic era, elucidating structure-function relationships of uncharacterized gene products based on the 3D protein structure. It proposes biochemical and cellular functions of unannotated proteins and thereby identifies potential drug design and protein engineering targets. Recently, a number of pioneering groups in structural proteomics research have achieved proof of structural proteomic theory by predicting the 3D structures of hypothetical proteins that successfully identified the biological functions of those proteins. The pioneering groups made use of a number of techniques, including NMR spectroscopy, which has been applied successfully to structural proteomics studies over the past 10 years. In addition, advances in hardware design, data acquisition methods, sample preparation and automation of data analysis have been developed and successfully applied to high-throughput structure determination techniques. These efforts ensure that NMR spectroscopy will become an important methodology for performing structural proteomics research on a genomic scale. NMR-based structural proteomics together with x-ray crystallography will provide a comprehensive structural database to predict the basic biological functions of hypothetical proteins identified by the genome projects. PMID:18761469

  5. 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. PMID:24689708

  6. 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.

  7. 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.

  8. Error-Correcting Data Structures

    CERN Document Server

    de Wolf, Ronald

    2008-01-01

    We study data structures in the presence of adversarial noise. We want to encode a given object in a succinct data structure that enables us to efficiently answer specific queries about the object, even if the data structure has been corrupted by a constant fraction of errors. This model is the common generalization of (static) data structures and locally decodable error-correcting codes. The main issue is the tradeoff between the space used by the data structure and the time (number of probes) needed to answer a query about the encoded object. We prove a number of upper and lower bounds on various natural error-correcting data structure problems. In particular, we show that the optimal length of error-correcting data structures for the Membership problem (where we want to store subsets of size s from a universe of size n) is closely related to the optimal length of locally decodable codes for s-bit strings.

  9. Properties of fast solitary structures

    Directory of Open Access Journals (Sweden)

    R. E. Ergun

    1999-01-01

    Full Text Available We present detailed observations of electromagnetic waves and particle distributions from the Fast Auroral SnapshoT (FAST satellite which reveal many important properties of large-amplitude, spatially-coherent plasma structures known as "fast solitary structures" or "electron phase space holes". Similar structures have been observed in several regions of the magnetosphere including the auroral zone, plasma sheet boundary layer, and bow shock. There has been rapid theoretical progress in understanding these structures. Solitary structures can develop from bidirectional electron beams. Once developed, the one-dimensional properties parallel to the magnetic field can be adequately described by analytical treatment as BGK structures. There remains, however, several unanswered questions. The origin of the bidirectional electron beams, the development of two-or three-dimensional structures, and the observed association with the ion cyclotron frequency are not well understood.

  10. RHYTHM STRUCTURE IN NEWS READING

    Directory of Open Access Journals (Sweden)

    Lluís Mas Manchón

    2013-06-01

    Full Text Available Rhythm is central to news reading in radio and television programs. This paper proposes a three level structure for rhythm in news discourse. It gives a comprehensive definition of rhythm and types of rhythm. Firstly, the Base Rhythm Structure consists of semantic and pragmatic rhythmic accents, coincident with very specific words. Secondly, these accents are grouped together according to type, frequency and order, thereby configuring three types of “rhythmic units” (the Internal Rhythm Structure: starting, main and end units. A last structure level presents four discursive factors that are very important in integrating the overall time structure of news announcing (the Melodic Rhythm Structure. This integral structure for news announcing rhythm should be further tested in acoustic-experimental studies under the criterion of information transmission efficacy.

  11. Structural biology at York Structural Biology Laboratory; laboratory information management systems for structural genomics

    Czech Academy of Sciences Publication Activity Database

    Dohnálek, Jan

    2005-01-01

    Roč. 12, č. 1 (2005), s. 3. ISSN 1211-5894. [Meeting of Structural Biologists /4./. 10.03.2005-12.03.2005, Nové Hrady] R&D Projects: GA MŠk(CZ) 1K05008 Keywords : structural biology * LIMS * structural genomics Subject RIV: CD - Macromolecular Chemistry

  12. Social status regulates growth rate: Consequences for life-history strategies

    OpenAIRE

    Hofmann, Hans A.; Benson, Mark E.; Fernald, Russell D.

    1999-01-01

    The life-history strategies of organisms are sculpted over evolutionary time by the relative prospects of present and future reproductive success. As a consequence, animals of many species show flexible behavioral responses to environmental and social change. Here we show that disruption of the habitat of a colony of African cichlid fish, Haplochromis burtoni (Günther) caused males to switch social status more frequently than animals kept in a stable environment. H. burtoni males can be eithe...

  13. ECONGAS - model structure

    International Nuclear Information System (INIS)

    This report documents a numerical simulation model of the natural gas market in Germany, France, the Netherlands and Belgium. It is a part of a project called ''Internationalization and structural change in the gas market'' aiming to enhance the understanding of the factors behind the current and upcoming changes in the European gas market, especially the downstream part of the gas chain. The model takes European border prices of gas as given, adds transmission and distribution cost and profit margins as well as gas taxes to calculate gas prices. The model includes demand sub-models for households, chemical industry, other industry, the commercial sector and electricity generation. Demand responses to price changes are assumed to take time, and the long run effects are significantly larger than the short run effects. For the household sector and the electricity sector, the dynamics are modeled by distinguishing between energy use in the old and new capital stock. In addition to prices and the activity level (GDP), the model includes the extension of the gas network as a potentially important variable in explaining the development of gas demand. The properties of numerical simulation models are often described by dynamic multipliers, which describe the behaviour of important variables when key explanatory variables are changed. At the end, the report shows the results of a model experiment where the costs in transmission and distribution were reduced. 6 refs., 9 figs., 1 tab

  14. Structural model of uramarsite

    International Nuclear Information System (INIS)

    The structural model of uramarsite, a new mineral of the uran-mica family from the Bota-Burum deposit (South Kazakhstan), is determined using a single-crystal X-ray diffraction analysis. The parameters of the triclinic unit cell are as follows: a = 7.173(2) A, b = 7.167(5) A, c = 9.30(1) A, α = 90.13(7)o, β = 90.09(4)o, γ = 89.96(4)o, and space group P1. The crystal chemical formula of uramarsite is: (UO2)2[AsO4][PO4,AsO4][NH4][H3O] . 6H2O (Z = 1). Uramarsite is the second ammonium-containing mineral of uranium and an arsenate analogue of uramphite. In the case of uramarsite, the lowering of the symmetry from tetragonal to triclinic, which is accompanied by a triclinic distortion of the tetragonal unit cell, is apparently caused by the ordering of the As and P atoms and the NH4, H3O, and H2O groups.

  15. 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...

  16. Structure of Solar Ejecta

    Science.gov (United States)

    Muñoz, G.; Cantó, J.; Lara, A.; González, R.; Schwenn, R.

    Solar Ejecta (SE) have been of interest in the last years, especially those which may reach Earth environment. It is possible to observe the SE early evolution, when they are in the field of view of coronagraphs. There are few indirect observations, as the case of interplanetary scintillation, of SEs in the interplanetary medium. Finally, we observe SEs in situ when they arrive at 1 AU.The SEs structure and evolution are important to understand the origin of these phenomena but to predict the possible effects in the space weather. It is of general acceptance that SEs are "Erupting Flux Ropes" traveling trough the Solar Wind. The "shapes" have been modeled as cylinders or as "ice cream cones" in order to represent the many different projections observed on Coronagraphs.We present a model of the SE evolution based on purely Hydrodynamic considerations. This model reproduces in good approximation some of the features observed in the images and in the measures of the shocks near Earth.

  17. Marine stratocumulus structure

    Science.gov (United States)

    Cahalan, Robert F.; Snider, Jack B.

    1989-01-01

    Thirty-three Landsat TM scenes of California stratocumulus cloud fields were acquired as part of the FIRE Marine Stratocumulus Intensive Field Observations in July 1987. They exhibit a wide variety of stratocumulus structures. Analysis has so far focused upon the July 7 scene, in which aircraft from NASA, NCAR, and the British Meteorological Office repeatedly gathered data across a stratocumulus-fair weather cumulus transition. The aircraft soundings validate the cloud base temperature threshold determined by spatial coherence analysis of the TM thermal band. Brightness variations in the stratocumulus region exhibit a -5/3 power-law decrease of the wavenumber spectra for scales larger than the cloud thickness, about 200 m, changing to a -3 power at smaller scales. Observations by an upward-looking three-channel microwave radiometer on San Nicolas Island also show the -5/3 power-law in total integrated liquid water, suggesting that the largest-scale TM brightness variations are primarily due to variations in the liquid water. The Kolmogorov 5/3 power suggests that for some purposes liquid water in turbulent stratocumulus clouds may be treated as a passive scalar, simply reflecting variations in vertical velocity. This may be tested using the velocities measured by the aircraft.

  18. Structures of exotic nuclei

    International Nuclear Information System (INIS)

    Discoveries of many different types of nuclear shape coexistence are being found at both low and high excitation energies throughout the periodic table, as documented in recent reviews. Many new types of shape coexistence have been observed at low excitation energies, for examples bands on more than four different overlapping and coexisting shapes are observed in 185Au, and competing triaxial and prolate shapes in 71Se and 176Pt. Discrete states in super-deformed bands with deformations β 2 ∼ 0.4-0.6, coexisting with other shapes, have been seen to high spin up to 60ℎ in 152Dy, 132Ce and 135Nd. Super-deformed nuclei with N and Z both around 38 and around Z = 38, N ≥ 60. These data led to the discovery of new shell gaps and magic numbers of 38 for N and Z and 60 for N but now for deformed shapes. Marked differences in structure are observed at spins of 6 to 20 in nuclei in this region, which differ by only two protons; for example, 68Ge and 70Se. The differences are thought to be related to the competing shell gaps in these nuclei

  19. 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.

  20. High thermal load structure

    International Nuclear Information System (INIS)

    A highly thermal load structure applied to a plasma-opposed equipment of a thermonuclear device comprises heat resistant protection tiles and a cooling tube disposed in the protection tiles. As the protection tiles, a carbon/carbon composite material is used. The carbon/carbon composite material on the heat receiving surface comprises carbon fibers disposed in one direction (one dimensionally) arranged from the heat receiving surface toward the cooling tube. The carbon/carbon composite material on the side opposite to the heat receiving surface comprises carbon fibers arranged two-dimensionally in the direction perpendicular to the longitudinal direction of the cooling tube. Then, the cooling tube is interposed between the one-dimensional carbon/carbon composite material and the two-dimensional carbon/carbon composite material, and they are joined with each other by vacuum brazing. This can improve heat removing performance. In addition, thermal stresses at the joined portion is reduced. Further, electromagnetic force generated in the thermonuclear device is reduced. (I.N.)

  1. 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...

  2. 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...

  3. 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.

  4. Dual structural-control optimization of large space structures

    Science.gov (United States)

    Messac, A.; Turner, J.

    1984-01-01

    A new approach is proposed for solving dual structural-control optimization problems for high-order flexible space structures where reduced-order structural models are employed. For a given initial structural dessign, a quadratic control cost is minimized subject to a constant-mass constraint. The sensitivity of the optimal control cost with respect to the stuctural design variables is then determined and used to obtain successive structural redesigns using a contrained gradient optimization algorithm. This process is repeated until the constrained control cost sensitivity becomes negligible. A numerical example is presented which demonstrates that this new approach effectively addresses the problem of dual optimization for potentially very high-order structures.

  5. Reliability of structure tensors in representing soft tissues structure.

    Science.gov (United States)

    Lanir, Yoram; Namani, Ravi

    2015-06-01

    Structure tensors have been applied as descriptors of tissue morphology for constitutive modeling. Here the reliability of these tensors in representing tissues structure is investigated by model simulations of a few examples of generated and measured planar fiber orientation distributions. Reliability was evaluated by comparing the data with the orientation density distribution recovered from the structure tensor representation, and with a orientation density recovered from an alternative representation by Fourier series of spherical harmonics. The results show that except for the case of uniform or close to uniform orientation distributions, the distributions recovered from the structure tensor fit the data poorly. On the other hand, orientation distributions recovered from Fourier series of spherical harmonics converge to the data distributions provided sufficient terms are included in the truncated series. These results suggest that the structure tensor is a reliable descriptor of tissue structure only under very limited cases. PMID:25828155

  6. Structural response of reduced scale naval structures under impact tests

    OpenAIRE

    Calle M.A.G.; Oshiro R.E.; Mazzariol L.M.; Alves M.

    2014-01-01

    Scaled models are important in naval engineering since actual ship size makes too expensive to test prototypes. However, the analysis of ship collision events employing naval structures in reduced scale is not an ordinary ship research area. The aim of this work is to create the basis for a posterior similarity study by analysing reduced scale ship structures submitted to impact loads. Two basic naval structures, commonly found in the construction of large ships, were considered for this stud...

  7. Predicting the Structural Performance of Composite Structures Under Cyclic Loading

    OpenAIRE

    Kassapoglou, C.

    2012-01-01

    The increased use of advanced composite materials on primary aircraft structure has brought back to the forefront the question of how such structures perform under repeated loading. In particular, when damage or other stress risers are present, tests have shown that the load to cause failure after a given number of cycles is a decreasing function of these cycles. This is a result of damage that was already present in the structure or was created during cyclic loading. In composites, multiple ...

  8. Decision analysis for deteriorating structures

    International Nuclear Information System (INIS)

    Measures that improve durability of a structure usually increase its initial cost. Thus, in order to make a decision about a cost-effective solution the life-cycle cost of a structure including cost of structural failure needs to be considered. Due to uncertainties associated with structural properties, loads and environmental conditions the cost of structural failure is a random variable. The paper derives probability distributions of the cost of failure of a single structure and a group of identical structures when single or multiple failures are possible during the service life of a structure. The probability distributions are based on cumulative probabilities of failure of a single structure over its service life. It is assumed that failures occur at discrete points in time, the cost of failure set at the time of decision making remains constant for a particular design solution and the discount rate is a deterministic parameter not changing with time. The probability distributions can be employed to evaluate the expected life-cycle cost or the expected utility, which is then used in decision making. An example, which considers the selection of durability specifications for a reinforced concrete structure built on the coast, illustrates the use of the derived probability distributions

  9. Structural design by CAD system

    International Nuclear Information System (INIS)

    CAD systems are now widely used for the design of many engineering problems involving static, dynamic and thermal stress analyses of structures. In order to apply CAD systems to the structural analysis and design, the function of hardwares and softwares necessary for the CAD systems must be understood. The purpose of this study is to introduce the basic elements that are indispensible in the application of CAD systems to the analysis and design of structures and to give a thorough understanding of CAD systems to design engineers, so as to participate in the further technological developments of CAD systems. Due to the complexity and variety of the shape and size of the nowa-days structures, the need of new design technologies is growing for more efficient, accurate and economical design of structures. The application of CAD systems to structural engineering fields enables to improve structural engineering analysis and design technologies and also to obtain the standardization of the design process. An active introduction of rapidly developing CAD technologies will contribute to analyzing and designing structures more efficiently and reliably. Based on this report of the current status of the application of CAD systems to the structural analysis and design, the next goal is to develop the expert system which enables to perform the design of structures by CAD systems from the preliminary conceptual design to the final detail drawings automatically. (Author)

  10. 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.

  11. 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

  12. Offshore concrete structures

    International Nuclear Information System (INIS)

    In the offshore industry there are two possible materials for the construction of the hull of a structure; the steel and concrete, with the first one widely used until now, as in the rest of the shiphuidling industry of merchant ships, warships, etc. Materials such as aluminum, GRP or timber areused in small units with lengths lower than 100 m, and in less adverse conditions than in the offshore industry. Nevertheless, some ships/barges have been built of concrete in the past, but have been rather isolated cases which have not changed the practice in the industry. In the First and Second World War were built by the scarcity of materials, while the series of barges by Alfred A. Yee was a rare exception. Other units were also made in concrete, but almost anecdotal. Still, the behaviour of these concrete structures, especially in terms of maintenance, has been excellent. Therefore, the fact that the concrete has not had an adequate reception so far in shipbuilding, does not mean that in will not be the material best suited for the offshore industry in the future. The extra displacement and associated fuel costs in concrete ships have been found prohibitive in the past. But the loss of mobility of a concrete hull in relation to a steel hull can be perfectly offset by the advantages offered by the concrete, as the shipping and offshore industry have very different priorities. One of the main differences in these priorities is in terms of maintenance and resistance to fatigue, precisely where the concrete performs better. ships can easily be dry docked for maintenance and repair, while in the offshore platforms these works have to be done in situ so maintenance and fatigue are crucial to them. Besides these, the concrete has other advantages according to findings of several studies. And although they are interested in the conclusions that the makes as they came from people in the concrete industry, the fact that in recent years concrete offshore unit shave been built

  13. PHENIX Work Breakdown Structure

    International Nuclear Information System (INIS)

    The Work Breakdown Structure (WBS) Book begins with this Overview section, which contains the high-level summary cost estimate, the cost profile, and the global construction schedule. The summary cost estimate shows the total US cost and the cost in terms of PHENIX construction funds for building the PHENIX detector. All costs in the WBS book are shown in FY 1993 dollars. Also shown are the institutional and foreign contributions, the level of pre-operations funding, and the cost of deferred items. Pie charts are presented at PHENIX WBS level 1 and 2 that show this information. The PHENIX construction funds are shown broken down to PHENIX WBS level 3 items per fiscal year, and the resulting profile is compared to the RHIC target profile. An accumulated difference of the two profiles is also shown. The PHENIX global construction schedule is presented at the end of the Overview section. Following the Overview are sections for each subsystem. Each subsystem section begins with a summary cost estimate, cost profile, and critical path. The total level 3 cost is broken down into fixed costs (M ampersand S), engineering costs (EDIA) and labor costs. Costs are further broken down in terms of PHENIX construction funds, institutional and foreign contributions, pre-operations funding, and deferred items. Also shown is the contingency at level 3 and the level 4 breakdown of the total cost. The cost profile in fiscal years is shown at level 3. The subsystem summaries are followed by the full cost estimate and schedule sheets for that subsystem. These detailed sheets are typically carried down to level 7 or 8. The cost estimate shows Total, M ampersand S, EDIA, and Labor breakdowns, as well as contingency, for each WBS entry

  14. Nano structured Magnetic Materials

    International Nuclear Information System (INIS)

    The saga of nanostructured magnetic materials (NMMs) has prevailed since the discovery of the first giant magnetoresistance (GMR) effect in metals in 1988. NMMs represent a unique system that incorporates the interplay between the properties associated with spin degrees of freedom and the nanoscaled structures, which provide a very strong platform for exploring both basic science and technical applications in the fields of solid-state physics, chemistry, materials science, and engineering. In fact, an active research field called “spintronics,” which has a big overlap with NMMs, has emerged and prevailed very recently. Through manipulation of spin of electrons in solids, a wide variety of NMMs and devices have been playing a prominent role in information processing and transport in our modern life. A rich variety of materials, such as transition metals, manganite, wide bandgap semiconductors, and nanocomposites, have already been developed for generating well-controlled nanostructures with new functionalities. Many scientists believe that the 21st century will be a “Century of Spin.” Nanomaterials and nanotechnologies have provided historical opportunities for research and development of novel spintronics materials and devices. NMSs manifest fascinating properties compared to the bulks because of size effect and quantum effect. Nanotechnologies have been proven to be an effective way to fabricate devices with fine nanostructures. The combination of spintronics and nanomaterials will undisputedly open new pathways in solid-state physics. The present special issue focuses on the recent development in the understanding of the synthesis, the studies on magnetic properties of nanostructures, and their potential applications based on the multiple functionalities.

  15. Optimal Investment in Structured Bonds

    DEFF Research Database (Denmark)

    Jessen, Pernille; Jørgensen, Peter Løchte

    2012-01-01

    of the article is to provide possible explanations for the puzzle of why small retail investors hold structured bonds. The investment universe consists of a stock index, a risk-free bank account, and a structured bond containing an option written on another index. We apply expected utility......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...... maximization 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...

  16. Wave Overtopping of Marine Structures

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter

    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...... 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. 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 to a...

  17. Characterization of DPOAE fine structure

    DEFF Research Database (Denmark)

    Reuter, Karen; Hammershøi, Dorte

    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, and...... 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...

  18. Integrated control-structure design

    Science.gov (United States)

    Hunziker, K. Scott; Kraft, Raymond H.; Bossi, Joseph A.

    1991-01-01

    A new approach for the design and control of flexible space structures is described. The approach integrates the structure and controller design processes thereby providing extra opportunities for avoiding some of the disastrous effects of control-structures interaction and for discovering new, unexpected avenues of future structural design. A control formulation based on Boyd's implementation of Youla parameterization is employed. Control design parameters are coupled with structural design variables to produce a set of integrated-design variables which are selected through optimization-based methodology. A performance index reflecting spacecraft mission goals and constraints is formulated and optimized with respect to the integrated design variables. Initial studies have been concerned with achieving mission requirements with a lighter, more flexible space structure. Details of the formulation of the integrated-design approach are presented and results are given from a study involving the integrated redesign of a flexible geostationary platform.

  19. Control Structures Interaction (CSI) Technology

    Science.gov (United States)

    Layman, W. E.

    1989-01-01

    Control Structures Interaction (CSI) technology for control of space structures is being developed cooperatively by JPL, LaRC and MSFC for NASA OAST/RM. The mid-'90s goal of JPL's CSI program is to demonstrate with analysis, ground and flight tests, the super quiet structures needed for large diffraction-limited instruments such as optical stellar interferometers and large advanced successors to the Hubble Space Telescope. Microprecision CSI technology is intended as a new "building block" for use by the designers of large optical systems. The thrust of the microprecision CSI technology effort is to achieve nanometer-levels of space structure stability/accuracy with designs which employ otherwise conventional spacecraft technologies. JPL design experiences have indicated the following CSI technology development areas are especially applicable to large optical system projects: (1) Active structural members; (2) Control/structures design methods; (3) Microdynamic effects characterization; and (4) Ground and flight test validation of CSI methods.

  20. Dissipative structures and related methods

    Science.gov (United States)

    Langhorst, Benjamin R; Chu, Henry S

    2013-11-05

    Dissipative structures include at least one panel and a cell structure disposed adjacent to the at least one panel having interconnected cells. A deformable material, which may comprise at least one hydrogel, is disposed within at least one interconnected cell proximate to the at least one panel. Dissipative structures may also include a cell structure having interconnected cells formed by wall elements. The wall elements may include a mesh formed by overlapping fibers having apertures formed therebetween. The apertures may form passageways between the interconnected cells. Methods of dissipating a force include disposing at least one hydrogel in a cell structure proximate to at least one panel, applying a force to the at least one panel, and forcing at least a portion of the at least one hydrogel through apertures formed in the cell structure.