bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does species trait composition influence macroinvertebrate responses to irrigation water withdrawals: Evidence from the Intermountain West, USA
Authors: Miller Scott W. , Wooster David , Li Judith L. 
Published: December 2009

AbstractIrrigation water withdrawals are ubiquitous in arid and semi‐arid regions; however, predictable macroinvertebrate responses have not emerged. Inconsistent responses are frequently attributed to the amount of water withdrawn, while physicochemical and biological differences among systems remain unstudied. In this study, we sought to determine if species traits influence macroinvertebrate responses to water withdrawals. We sampled above and below 12 independent water diversions experiencing discharge reductions greater than 75% in central and eastern Oregon and Washington, USA. When considering all 12 rivers, we observed significant alterations to the hydrologic environment, in addition to increased algal standing stocks, silt cover and minimum temperatures; however, macroinvertebrate responses were limited to increased downstream densities, as indices and community composition did not significantly change. Functionally, species traits were more sensitive than structural indices; proportional abundance for 12 of 52 species traits significantly differed above and below all points of diversion. Trait changes suggest a shift in functional composition to compensate for hydrologic alterations and reduced habitat area. Grouping references sites (upstream) by species trait composition revealed a strong ambient gradient of increasing resistance and resilience from high to low elevations; however, we did not find evidence for differential susceptibility to water withdrawals among trait‐based reference groups. Though water withdrawals changed the representation of select species traits, frequencies of trait states most vulnerable to water withdrawals were too homogenously distributed among sites to elicit differential responses among trait‐based reference groups. At larger spatial scales or among disparate hydrologic regimes, grouping systems by species traits will likely reduce variability and offer a more general currency for detecting perturbation response relationships. Copyright © 2009 John Wiley & Sons, Ltd.
Contrasting stream stability characteristics in adjacent urban watersheds: Santa Clara Valley, California
Authors: Jordan B. A. , Annable W. K. , Watson C. C. , Sen D. 
Published: December 2009

AbstractA comparative study of two adjacent stream channels in the Santa Clara Valley region of California provided an opportunity to study the relative effects of multi‐faceted watershed‐urbanization impacts on channel evolution and stability. Berryessa Creek (15.5 km2) and Upper Penitencia Creek (61.3 km2) have similar intrinsic watershed characteristics; however, urbanization processes have imposed distinctly different evolutionary trends in each watershed. The influences of drainage network manipulation, hydrologic routing and engineering infrastructure has resulted in Upper Penitencia Creek remaining relatively stable throughout the course of urbanization, while Berryessa Creek has experienced system‐wide channel instability problems. This study enumerates the many anthropogenic impacts and provides insight into basin alterations that can have either positive or negative feedbacks in maintaining or degrading channel stability throughout the course of urbanization.Results show that infrastructure that disrupts the bed material sediment continuity (such as large drop structures or sedimentation ponds) generate long‐term downstream channel instabilities leading to channel degradation and continued maintenance. Off‐line flow diversions (in this study percolation ponds) that do not disrupt bed material transport can emulate pre‐urbanization conditions offsetting channel degradation resulting from changes in hydrology. This study also demonstrates the degradational responses of a stream due to losses in riparian vegetation from water table lowering transforming a perennial stream into an ephemeral stream resulting in increased bank instability. The importance of maintaining floodplains for flood access and channel stability has also been identified and compared to conditions of channel encroachment to facilitate maintenance, which have further exacerbated downstream channel degradation, long‐term channel maintenance and dredging. Copyright © 2009 John Wiley & Sons, Ltd.
Ambient mass spectrometry: advances and applications in forensics
Authors: Green F. M. , Salter T. L. , Stokes P. , Gilmore I. S. , O'Connor G. 
Published: December 2009

AbstractAmbient mass spectrometry (ambient MS) is a powerful and rapidly growing new field that provides high sensitivity MS directly from surfaces at ambient pressure. There is now a rich evidence base in the published literature of the success of these methods for forensic analysis including: detection of explosives at nanogram levels; chemical composition of counterfeit pharmaceutical tablets, detection of drugs of abuse from biological liquids such as urine and plasma; breath analysis of metabolites; and imaging analysis for document verification and fingerprint identification. Recent developments in miniaturised (shoe‐box sized) mass spectrometers have enabled these developments to be translated to portable on‐scene detection and first responder usage. In this review, we illustrate and compare the effectiveness of the most popular and promising techniques of desorption electrospray ionisation (DESI), direct analysis in real time (DART), plasma assisted desorption ionisation (PADI) and extractive electrospray ionisation (EESI). Forensic analysis by its very definition must stand up to scrutiny in a court of law. It is therefore essential that measurements are repeatable, valid, traceable and fit for purpose. The establishment of a measurement infrastructure is therefore essential to ensure that the methods used may be accredited and conform to relevant quality systems and procedures. © Crown copyright 2009. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Durability of aluminum cooling system in electric power plants
Authors: Deflorian F. , Rossi S. , Fedel M. 
Published: December 2009

AbstractThe final step in gas turbine electric power production plants is the cooling of water after the turbine expansion. In some thermal plants, the temperature reduction of the recycling fluid is partially obtained by heat exchanging with the atmosphere by passing the fluid through huge aluminum heat exchangers. From the corrosion point of view, most critical is the starting step of the power plant, when the aluminum cooling system comes in contact with water for the first time and reaches a surface condition in dynamic equilibrium with the liquid. This paper describes a systematic study of aluminum surface evolution in the cooling system of an electric power plant during the first weeks of operation. Some aluminum samples were placed inside the cooling system in significant locations and removed after scheduled times. The surface conditions of the samples were characterized using surface analyses, electrochemical techniques and microscopic observations. At the same time, the chemical conditions of the recycling fluids were monitored. The obtained results describe the corrosion resistance of the aluminum surface as a function of the conditioning time, proving the growth of a partially protective layer able to produce corrosion decrease during the service time of the energy production plant. Copyright © 2009 John Wiley & Sons, Ltd.
Zur Bemessung von Lochleisten als duktile Verbundmittel in Verbundträgern aus höherfesten Materialien
Authors: Gündel Max , Dürr André , Hauke Bernhard , Hechler Oliver 
Published: December 2009

AbstractIm Rahmen eines gemeinsamen FuE‐Projekts der HOCHTIEF Construction AG und ArcelorMittal Belval & Differdange S. A. wurden umfangreiche experimentelle und theoretische Untersuchungen an Lochleisten als duktiles Verbundmittel durchgeführt. Ziel der Untersuchung ist die Entwicklung technisch hochwertiger und wirtschaftlicher Verbundbauteile aus höherfesten Werkstoffen (z. B. Beton C50/60 und Stahl S460), [1] bis [4]. Hierbei wurden insbesondere das Tragverhalten, die Traglast, die Duktilität und die Dauerfestigkeit von unterschiedlichen Lochleistenformen sowie das Gesamttragverhalten von Verbundbauteilen mit Lochleisten untersucht. Aufbauend auf den in Versuchen gewonnenen Erkenntnisse wurden Bemessungskonzepte für Lochleisten als Verbundmittel in Verbundträgern aus höherfesten Materialien entwickelt.Design of aperture plates as ductile shear connectors for composite beams with high strength materials.Within a joint research project of HOCHTIEF Construction AG and ArcelorMittal Belval & Differdange S. A. various experimental and theoretical investigations in aperture plates, as ductile shear connector for composite members have been carried out. The aim of the research has been to develop technically advanced and economic composite members with the application of high strength materials (e.g. steel S460 and concrete C50/60). The main focus of the research has been put on the load bearing behaviour, ultimate bearing capacity, ductility and fatigue resistance of different types of aperture plates geometries as well as the related overall bearing performance of the composite members with the application of these plates as shear connectors. Based on the conclusions from the experimental test results, design concepts for aperture plates as shear connectors for composite beams with the application of high strength materials have been developed.
Ermüdungsverhalten geschweißter Rohrknoten von Fachwerkverbundbrücken
Authors: Mangerig Ingbert , Romen Norbert 
Published: December 2009

AbstractIm Verbundbrückenbau werden in letzter Zeit anstatt vollwandiger Ausführungsvarianten vermehrt aufgelöste Fachwerkkonstruktionen aus Stahlhohlprofilen eingesetzt, da diese sowohl in Bezug auf gestalterische Grundsätze als auch hinsichtlich konstruktiver Gesichtspunkte Vorteile versprechen. Hierbei wird insbesondere bei Brückenentwürfen, deren Ausgestaltung eine Vielzahl unterschiedlicher Knotengeometrien erfordert, aus wirtschaftlichen Gründen die Verbindung zwischen Füllstab und Gurtrohr bevorzugt mit direkt geschweißten Knoten anstatt mit Stahlgussknoten ausgeführt. Aufgrund der durch die Knotengeometrie bedingten Spannungskonzentration im Bereich der Schweißnahtkerbe wird der Brückenentwurf bei dieser Ausführungsvariante maßgeblich von der dort vorherrschenden Ermüdungsfestigkeit beeinflusst. Nachdem die in den einschlägigen Normen bereitgestellten Nachweisverfahren gegen Ermüdung für die üblichen im Brückenbau verwendeten Abmessungen nicht anwendbar sind, ist die versuchstechnische Untersuchung zur Absicherung eines ausreichenden Ermüdungswiderstandes bisher unabdingbar. Dieser Beitrag bezieht sich auf insgesamt sieben Versuchskörper, die im Rahmen des Neubaus der Autobahnüberführung Suhl–Lichtenfels auf Ermüdung geprüft wurden.Fatigue behaviour of welded pipe intersections in steel‐concrete composite bridges.In the construction of modern steel‐concrete composite bridges, the steel part is increasingly built by circular hollow sections instead of steel plates. This type of bridge design shows advantageous characteristics concerning architectural aspects as well as benefits in the static load transfer. Especially if the design of the truss girder requires a large number of different node geometries, the connection between the braces and the lower and upper chord are for economic reasons preferably build by directly welded nodes instead of cast steel nodes. Due to the local joint discontinuity of the pipe intersections, the stress distribution is enhanced exactly in the area of the welding seams. As a consequence, the limited fatigue behaviour of the pipe intersections represents the critical aspect in the design of tubular truss‐girder bridges. The difficulties in the design of this construction type are due to the fact that the criterions for fatigue verification given in the current codes do not cover the typical dimensions used in bridge design. Therefore until now it is unavoidable to conduct large‐scale tests in order to verify a sufficient fatigue resistance. This article refers to a total of seven specimens tested on fatigue during the construction of the new Highway Overpass Suhl– Lichtenfels.
Längenabhängigkeit des Beulwiderstandes umfangsdruckbeanspruchter stählerner Kreiszylinderschalen
Authors: Ziółko Jerzy , Schneider Werner , Białek Tomasz , Heizig Tomasz , Gettel Marco 
Published: December 2009

AbstractDas Versagen von Silos und Tanks wird häufig durch Druckunterschiede zwischen Außen‐ und Innendruck verursacht. Obwohl es sich beim Lastfall konstanter Umfangsdruck um einen Basisbeulfall der Kreiszylinderschale handelt, sind selbst hierbei einige Fragen noch nicht geklärt. Vergleicht man die Beulwiderstände, die sich in den technischen Regelwerken nach dem experimentell gestützten spannungsbasierten Beulsicherheitsnachweis ergeben, mit den Versagenslasten, die man bei einem numerisch gestützten Beulsicherheitsnachweis unter Einbeziehung von geometrischen Ersatzimperfektionen ermittelt, ergeben sich Diskrepanzen im Bereich langer Schalen. Im Beitrag werden experimentelle Ergebnisse eines deutsch‐polnischen Kooperationsprojektes vorgestellt, das diesen Widersprüchen nachgeht. Die Auswertung der Ergebnisse zeigt, dass der Beulwiderstand dünnwandiger Schalen unter Umfangsdruck auch von der geometrischen Schalenschlankheit abhängt. Das wird gegenwärtig von den Vorschriften noch nicht erfasst, so dass lange Schalen konservativer als kurze Schalen bemessen werden.Influence of the length‐to‐radius ratio on the buckling resistance of cylindrical steel shells subject to hoop compression.The failure of silos and tanks is often caused by differences between outer and inner pressure. Although the load case hoop compression is a basic buckling case of cylindrical shells, there are still some problems that have to be tackled. For long cylinders, discrepancies arise when comparing the buckling resistances calculated from the experimentally based stress design of current design rules with the resistances derived from numerical buckling strength verifications using equivalent geometric imperfections. In the contribution, the experimental results of a German‐Polish research project, concerning that problem, are presented. The evaluation of the results reveals that the buckling resistance of thin‐walled cylindrical steel shells subject to hoop compression also depends on the geometrical slenderness. This fact is neglected in current design rules. Therefore, long cylinders are designed more conservatively than short cylinders.
Seismic assessment of rc buildings by estimation of effective parameters on seismic behaviour using non‐destructive tests
Authors: Moshtagh Ehsan , Massumi Ali 
Published: December 2009

SUMMARYSeismic assessment of existing buildings is needed in many cases: change in construction usage (change in applied loads), undesirable construction quality, disparity between standard specimen and technical specification of design, absence of construction plans and modification of codes. Seismic assessment is the first step towards rehabilitation of constructions or other schemes to decrease damages and personal injuries. In this regard, engineers should be able to precisely estimate effective parameters on seismic behaviour, to utilize them in mathematical modelling of structures for increasing their reliability. This aim can be achieved by destructive or non‐destructive tests (NDT). In this paper, NDTs for estimating static and dynamic characteristics of reinforced concrete structures are reviewed. Finally, two essential dynamic NDTs, forced vibration method and ambient vibration method, are discussed in detail, and are proposed for seismic assessment in all kinds of structures. Copyright © 2009 John Wiley & Sons, Ltd.
Experimental and numerical investigation of damaged concrete beams strengthened with FRP composed of different fibres and resins
Authors: Rahai Ali Reza , Saberi Mohammad Reza 
Published: December 2009

SUMMARYStrengthening of structures to avoid further damages is inevitable in different conditions. In this paper, to evaluate the effect of fibre‐reinforced polymer (FRP) plates on damaged and non‐damaged members, an extensive experimental programme is reported. Several beam specimens were built. Some specimens were strengthened after loading condition. The damaged specimens strengthened by FRP plates containing two different resins (epoxy or polyester) were tested. Other beam specimens were strengthened by composite plates before loading. Moreover, a numerical modelling procedure was performed, and it showed good agreement with experimental results. Results showed improvements in flexural capacity of damaged beams strengthened by FRP laminates or plates compared with the non‐damaged ones. Copyright © 2009 John Wiley & Sons, Ltd.
Imitator‐to‐innovator S curve and chasms
Authors: Ouyang Hongwu “Sam” 
Published: December 2009

AbstractOver the past 20 years, some latecomer firms in Korea and China have successfully transformed themselves from imitators into innovators. In this article, we focus on the imitator‐to‐innovator transformation process. We try to answer the following questions: What are the evolutionary paths and mechanisms? What may be the challenges in the transformation process? In this article, we suggest the technological capability building in latecomer firms can be characterized by successive S curves. And we use a five‐phase model and dynamic S curve to analyze their transformation from imitator to innovator. We also discuss the four chasms in the transformation and identify the challenges and three‐level factors facilitating chasm crossings. This article makes two contributions: proposing a new framework for and introducing the S curve and chasm into studying the latecomer firms' development, and elaborating key challenges in and major differences among the four chasms in the imitator‐to‐innovator transformation, which have been neglected in the literature. © 2010 Wiley Periodicals, Inc.
An empirical analysis of risk mitigation in the pharmaceutical industry supply chain: A developing‐country perspective
Authors: Enyinda Chris I. , Mbah Chris H. N. , Ogbuehi Alphonso 
Published: December 2009

AbstractGlobal pharmaceutical supply‐chain risk mitigation has become an important issue in the corporate boardroom. This article reports on the empirical findings of the quantification of risks that decision makers consider most important when deciding on a risk portfolio to mitigate and the manner in which risks are prioritized according to their importance. The empirical findings suggest that decision makers attached great importance to counterfeit, Food and Drugs Board, and exchange‐rate fluctuations. With respect to risk‐mitigation strategies, risk reduction is considered most important, followed by risk avoidance. Dynamic sensitivity analysis with respect to a change (increase) in the Food and Drugs Board did not result in any change in the ranking of risk policy options, while a change (increase) in counterfeit resulted in a change in the ranking between risk reduction and risk avoidance. Risk avoidance ranked number one, followed by risk reduction. Implications distilled from this article are far‐reaching for the Ghanaian pharmaceutical firms' managers. © 2010 Wiley Periodicals, Inc.
Cluster‐based coordination and routing framework for wireless sensor and actor networks
Authors: Shah Ghalib A. , Bozyigit Muslim , Hussain Faisal B. 
Published: December 2009

AbstractIn Wireless Sensor Actor Networks (WSAN), sensor nodes perform the sensing task and actor nodes take action based on the sensed phenomena. Generally, the network is configured to observe multiple events and to react upon each individual event accordingly. Time delay, energy efficiency and reliability are three important aspects of WSAN that require special attention. To ensure efficient and reliable operations of such heterogeneous WSAN, new communication protocols are imperative.In this paper, we propose an integrated cluster‐based coordination and routing (CCR) framework for WSAN, whose prime objective is to ensure reliable action with efficient energy consumption. In CCR, sensor nodes are first configured to form clusters by taking into account the residual energy of nodes and network density. Once the clusters are formed, cluster‐heads coordinate with the actors to forminteractive regions. The reliability of action is addressed in terms of in time data delivery to actors in interactive regions and actor–actor coordination to make sure that an actor perform action in the reported region. A novel real‐time data aggregation (RDA) approach is also incorporated in the framework to conserve energy by minimizing the number of transmissions and achieve fairness. Simulation experiments prove that the framework achieves energy efficiency and reports in‐time event to the actors for reliable actions. Copyright © 2009 John Wiley & Sons, Ltd.
Application of the actuator surface concept to wind turbine rotor aerodynamics
Authors: Sibuet Watters C. , Breton S.P. , Masson C. 
Published: December 2009

AbstractThe structure of blade tip vortices is recognized as a key issue in wind turbine aerodynamic modelling by many researchers in the field. In the search for an intermediate model between full Navier–Stokes and blade‐element momentum simulations, this article presents a method using rotating actuator surfaces to model wind turbine aerodynamics. An actuator surface is a simple planar surface, porous to the flow, which is characterized by velocity and pressure discontinuities, whose action on the flow is achieved through an attached system of forces. These discontinuities and forces are determined from blade‐element analysis and the Kutta–Joukowski relation. After implementing this concept in a three‐dimensional CFD (Computational Fluid Dynamics) method, results are produced for the experimental rotors of NREL and TUDelft. The method is validated against both experimental measurements and the predictions of three other numerical models for wind turbine aerodynamic analysis. Qualitative and quantitative comparisons show that the actuator surface concept agrees well with the other numerical models. In addition to rotor aerodynamic analysis, the actuator surface concept can be used in the study of wake aerodynamics, or as the Eulerian flow solver in hybrid methods. Copyright © 2009 John Wiley & Sons, Ltd.
Modelling–based approach for digital control design for nonlinear WECS in the power system
Authors: Muhando Endusa Billy , Senjyu Tomonobu , Omine Eitaro , Funabashi Toshihisa , Kim Chul‐Hwan 
Published: December 2009

AbstractThe case has been established that the wind power plant must be treated as an integral part of the electric system, thereby constituting the wind energy conversion system. Recent advancement in size and technology of wind turbines requires sophisticated control systems to effectively optimize energy conversion and enhance grid integration. As a first step toward controller design, modelling has become a prerequisite. This paper explores controller design based on modelling the wind speed as a stochastic process, and the wind turbine as a multi‐mass system with a soft shaft linking the turbine with the doubly fed induction generator. A control strategy incorporating a linear quadratic Gaussian (LQG) that relies on state estimation for full‐state feedback is proposed to augment a linear controller for generator torque control. The control objectives are to reduce stresses on the drivetrain and to ensure operation geared toward optimal power conversion. This study focuses on above‐rated wind speeds, and the LQG's main purpose is to add damping to the drivetrain, thereby minimizing cyclic fatigue, while a pitch control mechanism prevents rotor overspeed, thereby maintaining rated power. Simulations show the efficacy of the proposed paradigm in meeting the control objectives. Copyright © 2009 John Wiley & Sons, Ltd.