433 research outputs found

    Araneae and Opiliones From \u3ci\u3eTypha\u3c/i\u3e Spp. And \u3ci\u3ePhragmites Australis\u3c/i\u3e Stands of Green Bay, Lake Michigan, and an Exotic Spider Species Newly Reported From the U.S. Great Lakes Region

    Get PDF
    Invertebrates were sampled using pan traps in three paired sets of Typha spp. (cattail) and Phragmites australis (giant reed grass) habitats in Lake Michigan’s Green Bay in June and September 2002. The collection included 34 harvestmen belonging to one species (found at all three sites), and 180 spiders belonging to 25 species in eight families. The two habitats yielded similar numbers of spider taxa, and 16 species were restricted to one of the two habitats. Between 10 and 15 species were found at each site, and only five spider species were collected at all three sites. Four species appear to be new records for the state of Wisconsin, including the linyphiid spiders Hypomma marxii (Keyserling) and Sitalcus ruralis Bishop & Crosby, and the salticid Synageles noxiosus (Hentz). Of particular interest is the first report from the U.S. Great Lakes region of the clubionid spider Clubiona pallidula (Clerck), a species introduced from Eurasia

    Structural Design and Sensitivity Analysis of Semi-Rigid Pavement of a Motorway

    Get PDF
    This paper presents application of mechanistic-empirical methods in design of semi-rigid pavement for a section of a motorway in Poland. The stage construction was assumed. Three fatigue criteria were applied in the design. For asphalt fatigue cracking and subgrade soil the criteria from the Asphalt Institute (USA) were applied. For fatigue cracking of cement stabilized bases the Dempsey (USA) and De Beer (South Africa) criteria were applied. Software BISAR was used. Additional study was carried out to find the sensitivity of design thickness of asphalt layer related to several design factors. The most significant factors were (a) load transfer through shrinkage and reflective cracks, (b) high summer temperature which causes decrease of asphalt layers stiffness and increase of tensile stresses in cement stabilized bases, and (c) the effect of overloaded vehicles

    Identification and Control of Electron-Nuclear Spin Defects in Diamond

    Get PDF
    We experimentally demonstrate an approach to scale up quantum devices by harnessing spin defects in the environment of a quantum probe. We follow this approach to identify, locate, and control two electron-nuclear spin defects in the environment of a single nitrogen-vacancy center in diamond. By performing spectroscopy at various orientations of the magnetic field, we extract the unknown parameters of the hyperfine and dipolar interaction tensors, which we use to locate the two spin defects and design control sequences to initialize, manipulate, and readout their quantum state. Finally, we create quantum coherence among the three electron spins, paving the way for the creation of genuine tripartite entanglement. This approach will be useful in assembling multispin quantum registers for applications in quantum sensing and quantum information processing

    Blockchain use cases across entire lifecycle of a built asset: A review

    Get PDF
    Blockchain is a key enabling technology towards the 4th industrial revolution of the construction industry. The aim of this paper is to map uses of blockchain technology across the various phases in the lifecycle of built assets. Of interest to this paper is a new classification of blockchain solutions in combination with other key enabling technologies, like Building Information Modelling and Internet of Things. The literature indicates that blockchain shows high potential for solving challenges across the entire lifecycle of a project and has an especially high potential to influence and possibly improve management in the Operation and Maintenance phase

    Density-Dependent Effects on Microhabitat Selection and Activity of Two Species of Larval Ambystoma Salamanders

    Get PDF
    To be able to distinguish unnatural amphibian declines from natural population fluctuations we need a better understanding of the mechanisms that affect amphibian community structure. Larval pond-breeding salamanders exhibit density-dependent effects on population parameters, but little is known of the effect of density on behaviors that mediate interactions. Two species, Amby1toma tigrinum (tiger salamander) and A. laterale (blue-spotted salamander), were evaluated in laboratory aquaria for intraspecific and interspecific interactions that affect microhabitat selection and activity. Microhabitat selection was studied by partitioning containers into microhabitats that either contained or lacked refuges, and movement was recorded over a hexagonal grid to determine activity during periods of observation. Both species altered microhabitat preferences and activity levels when they shared tanks with con- or heterospecifics. These density-dependent behavioral changes may indicate that fluctuations in population densities result in behavioral responses that may contribute to coexistence

    Bose-Einstein Condensation and Spin Mixtures of Optically Trapped Metastable Helium

    Full text link
    We report the realization of a BEC of metastable helium-4 atoms (4He*) in an all optical potential. Up to 10^5 spin polarized 4He* atoms are condensed in an optical dipole trap formed from a single, focused, vertically propagating far off-resonance laser beam. The vertical trap geometry is chosen to best match the resolution characteristics of a delay-line anode micro-channel plate detector capable of registering single He* atoms. We also confirm the instability of certain spin state combinations of 4He* to two-body inelastic processes, which necessarily affects the scope of future experiments using optically trapped spin mixtures. In order to better quantify this constraint, we measure spin state resolved two-body inelastic loss rate coefficients in the optical trap

    Determination of Vehicles Load Equivalency Factors for Polish Catalogue of Typical Flexible and Semi-rigid Pavement Structures

    Get PDF
    AbstractThe new Polish Catalog of Typical Flexible and Semi-rigid Pavement Structures was introduced to use in practice in 2014. Much of works were focused on actualization of vehicles load equivalency factors. For this purpose data delivered from weigh-in-motion were analyzed. Four methods of determination of load equivalency factors for pavement structure design were compared. The analysis showed that fourth power equation, AASHTO, 1993 and French LCPC methods derived load equivalency factors at similar level and these obtained factors can be underestimated in comparison to results delivered from mechanistic-empirical method. The paper presents a new approach to determine load equivalency factors with consideration of several issues which have a significant impact on traffic load assessment for pavement design. The weigh-in-motion data are available only for a small part of whole road network, thus to determine values valid for roads in whole country, the statistical analysis of load equivalency factor were performed. The dynamic coefficient can have significant impact on load equivalency factor, especially on minor roads with weak roughness of pavement surface. The weigh-in-motion derives archival data and it is known from long-term observations that vehicles weights and axle loads increase while pavement life period. Legal axle load limit and the percentage of overloaded vehicles have significantly impact on load equivalency factors. The final values of vehicle load equivalency factor were adjusted to include the coefficient of vehicle dynamic loads, growth of vehicle weights in the future and impact of overloaded vehicles

    Comparison of current common data environment tools in the construction industry

    Get PDF
    The basic premise of a Common Data Environment (CDE) proposed by ISO19650 is exposing all relevant data as a single source of truth for all stakeholders. This work investigates tools currently used as CDE solutions in the industry and their practical challenges. Data was collected through a web search, a survey, and semi-structured interviews with industry professionals. Twelve tools were identified and compared in a desk review providing insights into their strengths and weaknesses. The results show that multiple CDEs are needed throughout the project lifecycle as no tool on the market can provide required functionalities in all lifecycle phases

    Determination of Silver Traces in Pure Metallic Copper and Zinc by a Catalytic Photometric Method

    Get PDF
    Determination of silver traces in the presence of copper, zinc and sulphate ions by a catalytic method was studied. The highly sensitive method of silver determination is based on the catalytic effect of silver ions on the oxidation of salicylic acid by persulphate in the presence of 2,2\u27-dipyridyl as an activator. The reaction was followed spectrophotometrically by measuring the rate of change in absorbance with time at 420 nm after 10 min of reagents mixing. The sensitivity, precision and accuracy of the determination of silver traces were investigated in solutions containing excesses of interfering ions. The studied range of interfering ions concentrations was 8 × 10–6 to 2.4 × 10–2 mol dm–3 and corresponds to an amount ratio of interfering to silver ions from 50 to 150 000. The performed analyses showed that the accuracy and precision of silver trace determination by the proposed method is high even in the presence of a huge amount excess of interfering ions. The method was used for quantitative determination of silver contents in a copper foil and in a zinc rod. The obtained results were compared with the analyses performed by FAAS

    The Phonetics and Phonology of the Polish Calling Melodies

    Get PDF
    Two calling melodies of Polish were investigated, the routine call, used to call someone for an everyday reason, and the urgent call, which conveys disapproval of the addressee’s actions. A Discourse Completion Task was used to elicit the two melodies from speakers of Polish using twelve names from one to four syllables long; there were three names per syllable count, and speakers produced three tokens of each name with each melody. The results, based on eleven speakers, show that the routine calling melody consists of a low F0 stretch followed by a rise-fall-rise; the urgent calling melody, on the other hand, is a simple rise-fall. Systematic differences were found in the scaling and alignment of tonal targets: the routine call showed late alignment of the accentual pitch peak and in most instances lower scaling of targets. The accented vowel was also affected, being overall louder in the urgent call. Based on the data and comparisons with other Polish melodies, we analyse the routine call as LH* !H-H% and the urgent call as H* L-L%. We discuss the results and our analysis in light of recent findings on calling melodies in other languages, and explore their repercussions for intonational phonology and the modelling of intonation
    • …
    corecore