816 research outputs found

    Properties of Random Graphs with Hidden Color

    Full text link
    We investigate in some detail a recently suggested general class of ensembles of sparse undirected random graphs based on a hidden stub-coloring, with or without the restriction to nondegenerate graphs. The calculability of local and global structural properties of graphs from the resulting ensembles is demonstrated. Cluster size statistics are derived with generating function techniques, yielding a well-defined percolation threshold. Explicit rules are derived for the enumeration of small subgraphs. Duality and redundancy is discussed, and subclasses corresponding to commonly studied models are identified.Comment: 14 pages, LaTeX, no figure

    Local atomic arrangement and martensitic transformation in Ni50_{50}Mn35_{35}In15_{15}: An EXAFS Study

    Full text link
    Heusler alloys that undergo martensitic transformation in ferromagnetic state are of increasing scientific and technological interest. These alloys show large magnetic field induced strains upon martensitic phase change thus making it a potential candidate for magneto-mechanical actuation. The crystal structure of martensite is an important factor that affects both the magnetic anisotropy and mechanical properties of such materials. Moreover, the local chemical arrangement of constituent atoms is vital in determining the overall physical properties. Ni50_{50}Mn35_{35}In15_{15} is one such ferromagnetic shape memory alloy that displays exotic properties like large magnetoresistance at moderate field values. In this work, we present the extended x-ray absorption fine-structure measurements (EXAFS) on the bulk Ni50_{50}Mn35_{35}In15_{15} which reveal the local structural change that occurs upon phase transformation. The change in the bond lengths between different atomic species helps in understanding the type of hybridization which is an important factor in driving such Ni-Mn based systems towards martensitic transformation

    The causal impact of economic growth on material use in Europe

    Get PDF
    Several scholars and policy-makers have claimed that Europe, and Western Europe in particular, has managed to ‘decouple’ economic growth from material use. We identify and address one major limitation in the existing literature – failure to take the endogeneity of economic growth into account. Based on a panel data-set of 32 European countries from 2000 to 2014, we estimate the causal impact of gross domestic product (GDP) on domestic material consumption (DMC) applying an instrumental variable approach. We use the number of storm occurrences as an instrument for GDP, which we show is both relevant and valid. Our results provide new evidence that increasing the GDP growth rate causes the DMC growth rate to increase for Western Europe, whereas the effect is insignificant for the Eastern European economies and Europe as a whole. As our results partly question current wisdom on the achievements of ‘decoupling’, especially among European policy-makers, we offer two explanations that are consistent with these results

    Relationships between two dimensions of employee perfectionism, postwork cognitive processing, and work day functioning

    Get PDF
    This daily diary study examined relations between two distinct perfectionism dimensions and work-related cognitions experienced by employees during evening leisure time. Drawing from perseverative cognitive processing theory, we hypothesized that perfectionistic concerns would be related to work-related worry and rumination during postwork evenings. In contrast, we hypothesized that a theoretically more adaptive perfectionist dimension (perfectionistic strivings) would be associated with positively valenced self-reflections about work across consecutive evenings. A sample of 148 full-time workers completed an initial survey, which included a trait perfectionism measure, reported their work-related cognitions across four consecutive evenings of a working week, rated their sleep quality immediately upon awakening on each subsequent morning, and their daily levels of emotional exhaustion and work engagement at the end of each work day. Results showed that perfectionistic concerns were indirectly negatively associated with sleep quality and work day functioning via the tendency to worry and ruminate about work. In contrast, perfectionistic strivings were indirectly positively associated with work day engagement via the propensity to experience positive thoughts about work during evening leisure time. The theoretical and practical implications of these findings are discussed

    Sexual Function in Women Suffering from Aortoiliac Occlusive Disease

    Get PDF
    AbstractObjective:to describe the sexual function in women suffering aortoiliac occlusive disease (AIOD) and in an age-matched reference group.Patients and methods:thirty-six women suffering from AIOD were included. Twenty were investigated before vascular intervention (untreated) and 16 different women after treatment (treated). Eighteen age-matched women served as areferencegroup. The patients answered a questionnaire including sexual, social and medical questions and a gynaecological examination was performed.Results:untreated patients with AIOD have a significantly impaired physical well-being compared to the other groups (p<0.001). A negative effect of the vascular disease and its treatment on sexual life was experienced by 69% oftreatedcompared to 40% affected amonguntreated(p=0.05). Vulval sensibility was impaired in 44% oftreated, 11% ofuntreatedand 22% ofreferencepatients. Defective anal sphincter function was found in 33% oftreated, 17% ofuntreatedand 6% in thereferencegroup. Those differences were not statistically significant.Conclusions:symptomatic AIOD in women is associated with a significantly impaired physical and sexual well-being. Though limited by size and methodology, the results indicate the possibility of iatrogenic nerve damage

    Graph Annotations in Modeling Complex Network Topologies

    Full text link
    The coarsest approximation of the structure of a complex network, such as the Internet, is a simple undirected unweighted graph. This approximation, however, loses too much detail. In reality, objects represented by vertices and edges in such a graph possess some non-trivial internal structure that varies across and differentiates among distinct types of links or nodes. In this work, we abstract such additional information as network annotations. We introduce a network topology modeling framework that treats annotations as an extended correlation profile of a network. Assuming we have this profile measured for a given network, we present an algorithm to rescale it in order to construct networks of varying size that still reproduce the original measured annotation profile. Using this methodology, we accurately capture the network properties essential for realistic simulations of network applications and protocols, or any other simulations involving complex network topologies, including modeling and simulation of network evolution. We apply our approach to the Autonomous System (AS) topology of the Internet annotated with business relationships between ASs. This topology captures the large-scale structure of the Internet. In depth understanding of this structure and tools to model it are cornerstones of research on future Internet architectures and designs. We find that our techniques are able to accurately capture the structure of annotation correlations within this topology, thus reproducing a number of its important properties in synthetically-generated random graphs

    The effect of microstructure on mechanical properties of HVOF sprayed WC-CoCr composite coatings

    Get PDF
    This study aims for deeper understanding of the composition and phase changes occurring during HVOF spraying of the powder to WC-CoCr coatings. Also, the effect of lamellar microstructure on the mechanical properties is studied. Compositional and microstructural features are studied by means of X-ray diffraction, XRF, FE-SEM and TEM (EDX, EELS). Mechanical properties are mainly studied by different instrumented indentation and nanoindentation techniques. The use of two new fracture parameters, complementing the fracture toughness value of the coating, are proposed and examined. Higher load range indentations are used to measure cross-sectional and surface hardness, elastic modulus and fracture toughness of the coatings. Mechanical properties of individual phases are studied by nanoindentation. To our knowledge this is the first time that the mechanical properties of this amorphous/nanocrystalline matrix are studied. ICP (In-situ Coating Property) sensor, developed for quality control and residual stress evaluation, is also used to measure the elastic modulus and coefficient of thermal expansion (CTE) of the coatings. Abrasion wear resistance of the coatings are studied according to standard ASTM G 65D. Because of the brittle nature of HVOF coatings, the main focus of this study is in the effects of coating microstructure on fracture toughness, and on crack initiation and propagation resistance. It is shown that even when two similar coatings have equal indentation fracture toughness values, the critical crack initiation loads may be very different. This new parameter is expected to be extremely useful in the evaluation of the coating performance under loading conditions

    A General Formalism for Inhomogeneous Random Graphs

    Full text link
    We present and investigate an extension of the classical random graph to a general class of inhomogeneous random graph models, where vertices come in different types, and the probability of realizing an edge depends on the types of its terminal vertices. This approach provides a general framework for the analysis of a large class of models. The generic phase structure is derived using generating function techniques, and relations to other classes of models are pointed out.Comment: 7 pages, no figures. To appear in Phys. Rev.
    • …
    corecore