bluuebunny/crossref_metadata_2025 huggingface dataset:
Channel Switching between Domestic and Foreign Markets
Authors: McNaughton Rod B. , Bell Jim
Published: December 2003

The authors develop a transaction cost model of the circumstances in which small, knowledge-intensive firms switch from the channel they use in the domestic market to a different channel in a foreign market. The authors argue that the domestic channel is frequently extended into a foreign market to gain economies of scale, because product characteristics are generally similar and because of strategic momentum. In knowledge-intensive sectors, integrated channels predominate in both domestic and foreign markets. Integrated channels facilitate the protection of knowledge-based assets and high levels of interaction with customers. However, firms may switch to a less-integrated mode in a foreign market if asset specificity is relatively low, as a response to environmental diversity, and when the market makes a small contribution to overall sales. Data gathered through a disk-by-mail survey of the export channel choices of Canadian software developers generally support these propositions. The authors make a contribution to the literature by rephrasing the channel selection decision so that the conditions under which firms switch modes are emphasized, thus linking the choice of modes in a foreign market to experience in the domestic market. The authors suggest that managers need to be aware of the momentum created by domestic channels and fully evaluate alternatives before extending existing channels into a foreign market. The results help identify conditions under which an international channel strategy that is different from the one used in the home market should be considered for a knowledge-intensive product.
Knowledge Transfer as a Means for Relationship Development: A Kazakhstan–Foreign International Joint Venture Illustration
Authors: Griffith David A. , Zeybek Ali Yavuz , O'Brien Matthew
Published: December 2003

Developing effective international joint ventures (IJVs) is critical for firms entering economies in transition, such as Kazakhstan. The resource-based view of the firm forms the foundation to examine the influence of knowledge transfer between IJV partners. Traditionally, the transfer of knowledge between IJV partners has been theorized to lessen dependence, increasing IJV instability. However, the relationship development literature indicates that the exchange of assets between partners can strengthen relationship ties, enhancing IJV stability. The authors use a sample of 87 matched dyads from two-party IJVs formed in Kazakhstan to examine the influence of knowledge transfer between IJV partners on commitment and resulting satisfaction. The results, supportive of relationship development theory, indicate that Kazakhstan–foreign IJVs with higher levels of knowledge transfer resulted in higher levels of firms’ commitment to and satisfaction with their relationships, thus supporting a relationship development perspective of knowledge transfer. The authors address implications for academics and practitioners.
Integration and Responsiveness: Marketing Strategies of Japanese and European Automobile Manufacturers
Authors: Grein Andreas F. , Craig C. Samuel , Takada Hirokazu
Published: December 2003

Formulating a strategy to compete effectively in international markets is one of the major challenges a firm faces. The authors provide insight into how automobile firms devise strategies that respond to the conflicting pressures for local responsiveness and integration in the context of Western Europe, where Japanese automobile firms compete with European-based manufacturers. The authors develop a conceptual framework to test integration–responsiveness in terms of marketing-mix responses and market conditions, using data that cover four major European markets (73% of Western European sales) and a critical period in European integration. The findings indicate that Japanese firms are successfully pursuing standardization strategies rather than fully combining integration and responsiveness. These firms competitively adapt to limited differences between markets, and this strategy appears to be quite successful compared with the European firms’ strategies of combining integration and responsiveness. The European strategy appears to undermine the ability to respond to Japanese firms’ targeted competitive moves, despite the presence of significant barriers to Japanese exports. Whereas Japanese firms were able to maintain market share, European firms’ market shares decreased over the three-year period examined.
The Effect of Export Assistance Program Usage on Export Performance: A Contingency Explanation
Authors: Gençtürk Esra F. , Kotabe Masaaki
Published: December 2003

On the basis of a synthesis of prior research, the authors develop a model, which integrates export marketing involvement and the use of government export promotion assistance programs as critical variables affecting export performance, and subject it to empirical evaluation. In this context, the authors also investigate organizational and managerial differences among the firms involved in export marketing to ascertain the robustness of and replicate the observed differences in firms’ export marketing involvement behavior. The results indicate that export marketing involvement of firms and firms’ usage of government export assistance programs are important export success factors. However, the relevance of export assistance programs and the role they play vary depending on the dimension of export performance being considered.
Factors Influencing the Degree of International Pricing Strategy Standardization of Multinational Corporations
Authors: Theodosiou Marios , Katsikeas Constantine S.
Published: December 2003

In response to certain important gaps identified in the global marketing literature, the focus of this inquiry is an investigation of the pricing strategies followed by manufacturing subsidiaries of multinational corporations. Specifically, the authors attempt to identify the factors that play an important role in determining the degree of international pricing strategy standardization. The findings suggest that the extent to which multinationals standardize their international pricing strategies depends on the level of similarity between home and host countries in terms of customer characteristics, legal environment, economic conditions, and stage of the product life cycle. The authors highlight implications of the findings for business practitioners and discuss future research directions along with the limitations of the study.
Cost Complexity of Pricing Decisions for Exporters in Developing and Emerging Markets
Authors: Raymond Mary Anne , Tanner John F. , Kim Jonghoon
Published: December 2003

As previously protected and emerging markets continue to open up for international trade, export firms often have a difficult time developing marketing strategies, particularly pricing strategies. However, few studies focus on the pricing practices of export firms, which makes it difficult to understand whether the same pricing strategies apply across markets, particularly in emerging markets. Using a framework of price complexity, the authors examine and compare the cost variables that are factored into price (price complexity) by export firms in the United States and Korea. The authors also investigate and compare some important noncost factors that influence pricing decisions for exporters in both their domestic and international markets. The results show that firms from the United States, a developed market, tend to factor more cost variables into price than do firms from an emerging market such as Korea. On the basis of the results of the study, the authors discuss implications for exporters and future research directions.
Do Chinese Trust Chinese? A Study of Chinese Buyers and Sellers in Malaysia
Authors: Armstrong Robert W. , Yee Siew Min
Published: December 2003

The objective of this article is to identify the major determinants of trust in the context of industrial buying behavior among ethnic Chinese buyers and sellers in Malaysia. The authors adopt the dyadic approach to examine empirically the antecedents and consequences of trust to secure a realistic assessment of the determinants and outcome of trust. The authors employ structural equation modeling to test the proposed trust models. The study identifies perceived intention, organizational trust, strength of personal relationship, dialect fluency, and perceived similarity in cultural values as major determinants of trust among ethnic Chinese industrial buyers and sellers in Malaysia. One important managerial consideration is the need for companies to place more emphasis on the cultural and relational factors that affect trust. The results of the study confirm that the presence of trust enhances buyer–seller relationships among ethnic Chinese businesspeople. Along with satisfaction, trust between the buyer and seller dictates the probability of future interaction between the exchange parties, and thus trust is a central concept in the business exchange process.
The Influence of Internet–Marketing Integration on Marketing Competencies and Export Performance
Authors: Prasad V. Kanti , Ramamurthy K. , Naidu G.M.
Published: December 2003

Internet technology is often considered to be fundamentally changing the business paradigm and increasingly integrated into the marketing function. The authors offer a conceptual model linking market orientation, marketing competencies, and export performance and investigate the role of the Internet technology in these relationships. On the basis of an analysis of survey data from 381 manufacturing firms involved in exporting, the authors find that firms' integration of Internet technology into marketing activities generally leverages the influence of market orientation on the firms' marketing competencies (compared with competitors), which in turn have a positive impact on their export performance. The authors identify competitive intensity, firm size, and degree of export dependence as additional moderating variables.
Understanding the Impact of Synergy in Multimedia Communications
Authors: Naik Prasad A. , Raman Kalyan
Published: November 2003

Many advertisers adopt the integrated marketing communications perspective that emphasizes the importance of synergy in planning multimedia activities. However, the role of synergy in multimedia communications is not well understood. Thus, the authors investigate the theoretical and empirical effects of synergy by extending a commonly used dynamic advertising model to multimedia environments. They illustrate how advertisers can estimate and infer the effectiveness of and synergy among multimedia communications by applying Kalman filtering methodology. Using market data on Dockers brand advertising, the authors first calibrate the extended model to establish the presence of synergy between television and print advertisements in consumer markets. Second, they derive theoretical propositions to understand the impact of synergy on media budget, media mix, and advertising carryover. One of the propositions reveals that as synergy increases, advertisers should not only increase the media budget but also allocate more funds to the less effective activity. The authors also discuss the implications for advertising overspending. Finally, the authors generalize the model to include multiple media, differential carryover, and asymmetrical synergy, and they identify topics for further research.
Interfirm Cooperation and Customer Orientation
Authors: Rindfleisch Aric , Moorman Christine
Published: November 2003

This article examines the implications of interfirm cooperation for a firm's level of customer orientation. Drawing on research in marketing, organizational theory, and economics, the authors suggest that firms engaged in cooperative alliances with competitors will become less customer oriented over time. Using longitudinal survey data, the authors find that firms in alliances dominated by competitors experience a significant decrease in their level of customer orientation. In contrast, the authors do not observe this type of decrease for firms in alliances dominated by channel members. Moreover, the authors find that both behavioral and structural mechanisms influence the relationship between alliance type and customer orientation. Behaviorally, firms in competitor-dominated alliances with weak relational ties with their collaborators exhibit a greater decrease in customer orientation compared with firms with strong ties with their collaborators. Structurally, firms that collaborate with competitors in alliances with a third-party monitor, such as a government agency, experience a smaller decrease in customer orientation than firms in alliances without such a monitor.
The Idiosyncratic Fit Heuristic: Effort Advantage as a Determinant of Consumer Response to Loyalty Programs
Authors: Kivetz Ran , Simonson Itamar
Published: November 2003

Over the past few years, customer relationship management and loyalty programs (LPs) have been widely adopted by companies and have received a great deal of attention from marketers, consultants, and, to a lesser degree, academics. In this research, the authors examine the effect of the level of effort required to obtain an LP reward on consumers' perception of the LP's attractiveness. The authors propose that in certain conditions, increasing program requirements can enhance consumers' likelihood of joining the program, thus leading consumers to prefer a dominated option. Specifically, the authors hypothesize that consumers often evaluate LPs on the basis of their individual effort to obtain the reward relative to the relevant reference effort (e.g., the effort of typical other consumers). When consumers believe they have an effort advantage over typical others (i.e., an idiosyncratic fit with the LP), higher program requirements magnify this perception of advantage and can therefore increase the overall perceived value of the program. The authors support this proposition in a series of studies in which the perceived idiosyncratic fit was manipulated either by reducing the individual effort or by raising the reference effort. The authors' findings also indicate that (1) idiosyncratic fit considerations are elicited spontaneously, (2) idiosyncratic fit mediates the effect of effort on consumer response to LPs, and (3) an alternative account for the results based on signaling is not supported. The authors conclude that the findings are part of a broader phenomenon, which they term the “idiosyncratic fit heuristic,” whereby a key factor that affects consumers' response to marketing programs and promotional offers is the perceived relative advantage or fit with consumers' idiosyncratic conditions and preferences.
The Differential Interaction of Auditory and Visual Advertising Elements with Chinese and English
Authors: Tavassoli Nader T. , Lee Yih Hwai
Published: November 2003

Multimedia advertisements often contain nonverbal auditory elements, such as music and sound effects, and nonverbal visual elements, such as images and logos. On the one hand, these elements can have the unintended negative effect of interfering with the processing of the verbal ad copy. Two experiments demonstrate that auditory elements interfere more with the learning of and cognitive responding to English ad copy than with Chinese ad copy, and vice versa for visual elements. On the other hand, auditory and visual elements have the intended positive effect of facilitating ad copy recall when they are reinstated as part of an integrated marketing campaign or as a recall cue in an advertising tracking study. A third experiment demonstrates that auditory elements are better retrieval cues for English than for Chinese ad copy, and vice versa for visual elements. The authors discuss implications of these cross-linguistic differences for the effective design of multimedia communications, integrated marketing campaigns, advertising tracking studies, and cross-cultural research.
Selective Sampling for Binary Choice Models
Authors: Donkers Bas , Franses Philip Hans , Verhoef Peter C.
Published: November 2003

Marketing problems sometimes pertain to the analysis of dichotomous dependent variables, such as “buy” and “not buy” or “respond” and “not respond.” One outcome can strongly outnumber the other, such as when many households do not respond (e.g., to a direct mailing). In such situations, an efficient data-collection strategy is to sample disproportionately more from the smaller group. However, subsequent statistical analysis must account for this sampling strategy. In this article, the authors put forward the econometric method that can correct for the sample selection bias, when this method does not lead to a loss in precision. The authors illustrate the method for synthetic and real-life data and document that reductions of more than 50% in sample sizes can be obtained.
XQuery, eine Querysprache für XML (XQuery, an XML Query Language)
Authors: Harbarth Juliane
Published: December 2003

Mit XQuery legt das W3C einen Vorschlag für eine XML-Anfragesprache vor, die der baumartigen Struktur von XML Rechnung trägt. Dieser Beitrag gibt einen Überblick über die Funktionalität von XQuery und seine Entwicklungsgeschichte.
Stability of U(VI) solid phases in the U(VI)-Ca2+-SiO2-OH system
Authors: Ritherdon B. , Phelps C. , Neff H. , Sowder A.G. , Clark S.B.
Published: December 2003

Synthetic metaschoepite was altered at 70 °C, for 30 days in silicate solutions of varying compositions to study alteration reactions and to compare experimental observations with a thermodynamic model of stability of the uranyl minerals metaschoepite ([(UO2)8O2(OH)12](H2O)10), becquerelite (Ca[(UO2)3O2(OH)3]2(H2O)8), α-uranophane (Ca[(UO2)(SiO3OH)]2(H2O)5) and soddyite ((UO2)2(SiO4)· (H2O)2). Powder X-ray diffraction analysis, scanning electron microscopy and solution chemistry were used to monitor the alteration of the initial metaschoepite. In general, the secondary phases predicted by the thermodynamic model formed. However, an unexpected mineral (a calcium uranate) was observed above pH 8. Also, within the timeframe of these experiments, U(VI) silicate phases only formed at Si concentrations much higher than the lower field boundaries for uranophane and soddyite.
Thermochromatographic studies of berkelium chlorides: BkCl3and BkCl4
Authors: Yakushev Alexander B. , Eichler B. , Türler A. , Gäggeler H.W. , Peterson J.
Published: December 2003

The thermochromatographic behavior of berkelium chlorides in various chlorinating gases was studied. Using Cl2or a mixture of Cl2/SOCl2, two peaks were observed in a thermochromatographic column. The "high temperature" peak corresponds to BkCl3and the "low temperature" one corresponds most probably to BkCl4. Using both the model of mobile adsorption and the of Monte Carlo method, the adsorption enthalpies were determined. The possible chemical reactions in a chromatographic column are discussed.
Thermodynamic modeling of metal–ligand interactions in high ionic strength NaCl solutions: the Ni2+-oxalate system
Authors: Borkowski M. , Choppin Gregory R. , Moore Robert C.
Published: December 2003

Stability constants for the 1:1 and 1:2 complexes of Ni(II)+Oxalate have been determined using solvent extraction. Data collected in 0.3m to 5.0m NaCl aqueous solutions at 20.0±0.1°C yielded values of logβ101ranging from 3.71 to 3.98(±0.06) and of logβ102from 6.44 to 6.95(±0.06), which agree well with values from the literature. The data were analyzed by the Pitzer model with a value ofμ0/RT=-17.47 for the 1:1 complex calculated from the data and literature values. A single neutral-ion interaction parameter λNiOx-Cl=-0.179 was used to describe the ionic strength dependence of the 1:1 complex. For the 1:2 complex, a value forμ0/RT=-11.31 and the Pitzer parameters values,β0NiOx₂²⁻-Na⁺=-0.0644 andβ1NiOx₂²⁻-Na⁺=0.8545, were determined. These standard chemical potential values are based on a model for oxalate deprotonation reported earlier.
Concentration distributions of radionuclides in sediments along the Romanian sector of the Danube River and the Black Sea coast
Authors: Mihai S. A.
Published: December 2003

Concentration distributions of 238U, 232Th, 226Ra, 210Po, 137Cs and 238,239,240Pu in sediment samples, collected along the Romanian sector of the Danube River and the Black Sea coast, indicated the same pattern of accumulation of the radionuclides in the investigated samples. The mineralogical structure of sediment samples investigated by X-ray diffraction on random and oriented slides and the cation exchange capacity determined by the silver-thiourea procedure were used to explain this pattern of accumulation. The clay mineral content of the samples, the type of clay mineral and the geochemical behaviour of the radionuclides are discussed as important factors for a preferential accumulation of contaminants in sediments.
Development of selective cobalt and cesium removal from the evaporator concentrates of the PWR Paks
Authors: Szöke Szabolcs , Pátzay György , Weiser László
Published: December 2003

At the PWR Paks (Hungary) the diluted radioactive waste water is converted to a concentrate by evaporation and the concentrate is stored in tanks. The most important radionuclides in these solutions are 134Cs, 137Cs and 60Co. In this research we studied granular potassium nickel hexacyanoferrate(II) as a Cs-selective ion-exchanger. Its capacity depended on the preparation method, temperature of pretreatment and age of the ion exchanger. We investigated also the effect of metal ions (Fe2+, Fe3+, Mn2+, Mg2+, Ca2+, Co2+, Ni2+, Cu2+) on the Cs-capacity in the presence of complex forming compounds citrate, oxalate and EDTA. The cesium ion exchange capacity increased with addition of inactive cobalt or nickel salts. Additionally we studied filtration, adsorption and ultrafiltration separation processes for cobalt removal. The results showed that only adsorption by active carbon could be successfully used for the cobalt removal from evaporation concentrates. Experiments were performed both in the laboratory and at the PWR Paks.
Determination of binary data for neptunium(V) nitrate
Authors: Kappenstein-Grégoire A. C. , Moisy Ph. , Cote Gerard , Blanc P.
Published: December 2003

A stock solution consisting of a highly concentrated binary solution of neptunium(V) nitrate [NpVO2(NO3)] in water (about 4.5mol kg-1) was prepared and used to obtain a series of binary NpVO2(NO3)-H2O or ternary NpVO2(NO3)-HNO3-H2O solutions whose neptunium concentration ranged between about 0.22 and 4.5mol kg-1. Water activity and/or osmolality of these binary and ternary solutions were measured and used to calculate the variation of the osmotic coefficient of the real or fictive binary solutions versus NpVO2(NO3) concentration. The variation of the mean stoichiometric activity coefficient of this salt in water was then calculated. The densities of these solutions were also measured and used to express the activity coefficient values on both the molar and molal concentration scales.
Complex formation between uranium(VI) and α-D-glucose 1-phosphate
Authors: Koban A. , Geipel G. , Bernhard G.
Published: December 2003

The complex formation of uranium(VI) with α-D-glucose 1-phosphate (C6H11O6PO3
2-, G1P) was determined by time-resolved laser-induced fluorescence spectroscopy (TRLFS) at pH 4 and potentiometric titration in the pH range from 3 to 10. Both measurements show the formation of a 1:1 complex at lower pH values. The formation constant of UO2(C6H11O6PO3) was calculated from TRLFS measurements to be log β
11=5.72±0.12, and from potentiometric titration log β
11=5.40±0.25, respectively.It was found by potentiometric titration that at higher pH values the complexation changes to a 1:2 complex. The stability constant for this complex was calculated to be log β
12 = 8.96±0.18.
Neptunium and plutonium sorption to Snake River Plain, Idaho soil
Authors: Mincher Bruce J. , Fox Robert V. , Cooper D. Graig , Groenewold Gary S.
Published: December 2003

The behavior of Np and Pu on soil collected from the subsurface disposal area at the Idaho National Engineering and Environmental Laboratory was investigated by performing short-duration, sorption experiments to measure sorption isotherms. Neptunium sorption can be described with a Freundlich isotherm; however, Pu sorption can only be described in this fashion as a conservative estimate of minimum sorption. Geochemical modeling predictions suggest that initial sorption of Np is controlled predominantly by surface complexation on clay minerals, while Pu is controlled by a competition between complexation with iron oxyhydroxides and the precipitation of hydrolysis products. Longer-term sorption is governed by the transformation of these species to oxide minerals. Solution ionic strength and carbonate alkalinity did not significantly affect Np or Pu soil sorption.
Einsteinium chemistry in the gas phase: exploring the divalent character of heavy actinides
Authors: Gibson John K. , Haire Richard G.
Published: December 2003

The first chemical studies of the monopositive einsteinium ion, Es+, in the gas phase have been carried out, and its behavior compared to those for other actinide ions, with a particular focus on Bk+. The yield of laser-ablated EsO+ indicates that the Es+-O bond energy is significantly smaller than that of Bk+-O. Fluorination of Es+ and Bk+ through F-abstraction from hexafluoropropene demonstrated clearly the stability of the divalent state of Es: whereas by this process both BkF+ and BkF2
+ are produced, only the "divalent" EsF+ product is formed. The reaction of Es+ with several different alkenes produced only small yields of adducts (e.g., EsC4H8
+). These adducts are the first organoeinsteinium complexes to be identified. Whereas Es+ was inert towards 1,5-cyclooctadiene, in contrast Bk+ dehydrogenated this substrate to give BkC8H8
+, demonstrating the greater activation activity of Bk+ than Es+ towards alkenes. The chemical behaviors observed in these studies are consistent with the predicted electronic structure and energetics of Es+, and the results obtained are discussed in the context of systematic trends across the actinide series.
A kinetic model of the oxidative dissolution of brannerite, UTi2O6
Authors: Thomas Bronwyn S. , Zhang Y.
Published: December 2003

The aqueous dissolution of synthetic brannerite (UTi2O6) in an open atmosphere has been investigated. Previous data in the literature have been combined with new experimental work, dealing with the release of uranium from brannerite as a function of solution pH and aqueous carbonate species, in oxygenated solutions. From these data we have developed a conceptual model for uranium release from brannerite consisting of two reaction steps: oxidation of surface uranium(IV) atoms, and subsequent detachment of U(VI) atoms into solution, which is catalysed by surface coordination with protons (acidic media) or carbonate species (alkaline media in equilibrium with the atmosphere). A kinetic rate law is derived for this simple reaction mechanism and fitted to experimental data. The resulting predictive equation for uranium release qualitatively describes the pH-dependent behaviour observed in experiment, and quantitatively gives an upper limit for uranium release from brannerite over a range of conditions and experiment types.
Determination of Mo(VI), Ru(III), Re(VII) and NO3-in the solutions of nuclear fuel cycle by capillary electrophoresis
Authors: Fourest B. , Maslennikov A. , David F. , Masson M.
Published: December 2003

A method for simultaneous quantitative determination of Mo(VI), Re(VII), Ru(III) and NO3-ions in aqueous solutions, using capillary zone electrophoresis (CZE) technique with direct UV detection, was developed. Electrophoretic mobility of Ru(III) ions in 0.1M NaHCO3solution was determined as 6.0×10-8m2V-1s-1at 25 °C. The best analytical characteristics of the developed method were achieved with a 100mM carbonate buffer solution containing 0.3mM TTAB, at a pH value of 9.8 and at an applied voltage of 10kV. Under these conditions, a linear relationship between the measured absorbance (λ=230nm) and the concentration of the species under study were observed in the range 5×10-6–10-3M for Mo(VI), 7×10-6–10-3M for Re(VII) and 10-5–-4M for Ru(III). The minimum detectable concentrations were determined as 4.1×10-6M for NO3-, 5.2×10-6M for Mo(VI), 7.4×10-6M for Re(VII) and 1.0×10-5M for Ru(III). The accuracy of quantitative determination was estimated as 3%–5% for NO3-and 5%–6% for Mo(VI), Re(VII) and Ru(III) ions. The presence of 0.06M NaNO3(HNO3) and of 10-3M U(VI) in the sample affected neither the detection limits of the species under study nor the selectivity of the method.
Preparation of225Ac and228Ac generators using a cryptomelane manganese dioxide sorbent
Authors: Wlodzimirska B. , Bartoś B. , Bilewicz A.
Published: December 2003

The distribution coefficients of Ra2+and Ac3+on cryptomelane MnO2from acidic aqueous solutions were determined in order to find the best conditions for separation of both cations. Very high affinity of cryptomelane MnO2for Ra2+ions make possible to separate225Ac from225Ra, and228Ac from228Ra in single-step and rapid procedure. The obtained results enable to design simple and effective generators of225Ac and228Ac from their mother radium isotopes.
Formvermessung an bewegten technischen Oberflächen mittels der Speckle-Interferometrie (Contouring of Moving Technical Surfaces via Speckle-Interferometry)
Authors: Meixner Andreas , Zeh Thomas , Riemenschneider M. , Purde A. , Koch Alexander W.
Published: December 2003

Ständig steigende Anforderungen an die Qualitätsprüfung in der industriellen Fertigung erfordern neue Verfahren zur schnellen und zerstörungsfreien Oberflächenprüfung. Für die Formvermessung technischer Oberflächen bietet sich hierfür die Zwei-Wellenlängen-Technik der Speckle-Interferometrie an. Die bisher sehr hohe Störempfindlichkeit interferometrischer Messungen auf erschütterungsbedingte Bewegungen des Messobjektes sowie eine lange Rechenzeit zur Auswertung der Interferogramme ließen eine industrielle Anwendung kaum zu. Ein neu konzipierter Interferometeraufbau wird vorgestellt, der mittels zweier räumlich getrennter Kameras die simultane Aufzeichnung aller für die interferometrische Formvermessung notwendigen Daten und somit auch die Messung an bewegten Objekten erlaubt. Eine am Datenfluss orientierte, hardwarebasierte Auswertung mit FPGAs (Field Programmable Gate Arrays) ermöglicht die Online-Auswertung mit einer hohen Bildrate, wodurch der Aufbau als Messeinrichtung für den industriellen Einsatz attraktiv wird.
Hochauflösende Ultraschall-Entfernungsmessung für große Distanzen (High Resolution Ultrasonic Distance Measurement for Long Distances)
Authors: Elmer Hannes , Schweinzer Herbert , Magerl Gottfried
Published: December 2003

Dieser Beitrag gibt einen Überblick über Probleme ultraschallbasierter Entfernungsmesssysteme für industrielle Anwendungen. Das 1-Bit-Korrelationsverfahren vereinfacht die Behandlung der stark unterschiedlichen Empfangspegel und die Echtzeitsignalverarbeitung. Der Vergleich der A-B-Messung mit auf passiver Reflexion basierenden Verfahren führt zu der neuen Methode der aktiven Reflexion. Weiterhin wird ein Ultraschall-Wandler analysiert und sein Einfluss auf breitbandige Signale bei Verwendung korrelativer Empfänger diskutiert.
Einsatz von Klopfsensoren zur Erkennung von Verbrennungsaussetzern (Application of Knock Sensors for Engine Misfire Detection)
Authors: Lindemann Michael
Published: December 2003

Die Erkennung von Verbrennungsaussetzern ist eine große Herausforderung im Bereich der Kraftfahrzeugdiagnose. Der vorliegende Artikel beschreibt ein alternatives Verfahren zur Erkennung von Verbrennungsaussetzern mit Klopfsensoren. Es wird eine neuartige Methode vorgestellt, mit der sich verbrennungsrelevante Informationen aus dem Klopfsensorsignal extrahieren lassen und anschließend diagnostiziert werden kann, ob ein Verbrennungsaussetzer aufgetreten ist oder nicht.
Thermomechanische Einflüsse der Chipklebung auf die Genauigkeit mikromechanischer Drucksensoren Teil 1: Simulation (Thermomechanical Effects of the Adhesive Die Attachment on the Accuracy of MEMS Pressure Sensors)
Authors: Wilde Jürgen , Deier Erik
Published: December 2003

Thermomechanische Belastungen können die Funktionsfähigkeit mikrosystemtechnischer Komponenten beeinflussen. In dieser Arbeit werden die thermomechanischen Aspekte der Montagetechnik sowie der Aufbautechnik betrachtet. Basis der Untersuchungen sind die Darstellung der mechanischen Eigenschaften und Verformungsmodelle von leitfähigen Klebstoffen. Dabei werden die Anforderungen an passende Materialgesetze und Werkstoffdaten für modellbasierte Simulation aufgezeigt. Im zweiten Abschnitt wird ein Beispiel zur Vorhersage des Einflusses von Leitklebverbindungen und AVT auf die Genauigkeit eines mikromechanischen Drucksensors mit Hilfe der Finite-Elemente-Simulation untersucht. Bei Drucksensoren verursacht die nicht temperaturstabile Montage-Klebverbindung eine Beeinträchtigung des Langzeitverhaltens und eine Nullpunktsdrift, die prognostiziert werden kann.
Angepasste Signalverarbeitung für piezoresistive Drucksensoren (Well Adapted Signal Processing for Piezoresistive Pressure Sensors)
Authors: Zahout Carsten , Werthschützky Roland
Published: December 2003

Ziel der Untersuchungen ist die Optimierung der Messkette piezoresistiver Sensoren durch die Primärelektronik. Voruntersuchungen an piezoresistiven Primärsensoren und an der Primärelektronik für piezoresistive Sensoren hatten gezeigt, dass die Messunsicherheit der Messkette maßgeblich durch die zufälligen Fehlereinflüsse des Primärsensors beeinflusst wird. Das Optimierungsziel war deshalb die Kostenreduzierung bestehender Primärelektronik-Konzepte durch systematische Vereinfachung und Variation von Schaltungen zur Widerstandsbestimmung. Es konnten alternative Konzepte entwickelt werden, die eine mit herkömmlichen Primärelektroniken vergleichbare Messunsicherheit aufweisen, aber durch die Verwendung kostengünstiger Bauteile preisliche Vorteile besitzen.
Temperature‐dependent streaming potentials: 2. Laboratory
Authors: Reppert Philip M. , Morgan Frank Dale
Published: November 2003

Streaming potentials and zeta potentials were measured at equilibrium conditions, while at elevated temperatures of 23°–200°C and pressures of 20 MPa, on intact rock samples of Fontainebleau Sandstone, Berea Sandstone, and Westerly Granite using the oscillatory data collection method. The streaming potential coupling coefficient for Fontainebleau Sandstone decreased in magnitude from 195 nV/Pa at 23°C to 33 nV/Pa at 160°C before rising to 41 nV/Pa at 200°C. The Berea Sandstone coupling coefficient decreased in magnitude from 100 nV/Pa at 23°C to 23 nV/Pa at 160°C and then increased in magnitude to 100 nV/Pa at 200°C. The Westerly Granite coupling coefficient increased in magnitude from 23 nV/Pa at 40°C to 68 nV/Pa to 120°C, then decreased in magnitude to 43 nV/Pa at 160°C, and then increased in magnitude to 50 nV/Pa at 200°C. The zeta potential for all three samples increased in magnitude with increasing temperature, during these equilibrium experiments, which did not mirror the coupling coefficient responses. The temperature dependence of the zeta potential provides indications of possible chemistry changes occurring within sample, such as pH, ionic concentration, and ionic composition. These experiments confirm that knowledge of rock/solution chemistry is important for modeling coupling coefficients and zeta potentials. Results of the experimental work are compared to a model that predicts zeta potential variation with temperature, and reasonable correlations are obtained.
Effect of sea state on the momentum exchange over the sea during neutral conditions
Authors: Smedman Ann‐Sofi , Guo Larsén Xiaoli , Högström Ulf , Kahma Kimmo K. , Pettersson Heidi
Published: November 2003

On the basis of an extensive data set from the air‐sea interaction station Östergarnsholm in the Baltic Sea, the dependence of drag on the ocean of wave state parameters has been studied for near‐neutral conditions. For developing sea, the drag depends on wave age, u*/cp (u* friction velocity and cp the phase speed of the dominant waves), in agreement with recent findings over the World Ocean, strongly supporting that the Östergarnsholm station can be relied upon to give results representative of open ocean conditions. For such conditions, it is demonstrated that the logarithmic wind law is indeed valid. For mixed sea/swell the logarithmic wind law is not valid and the drag coefficient, CD depends on two parameters representing the wave state: u*/cp and E1/E2, where E1 is the energy of the relatively long waves (having a phase velocity larger than the wind speed at 10 m) and E2, the short wave energy. Thus, plotting CD as a function of u*/cp gives a clear ordering of the data in parallel, sloping bands according to the value of E1/E2. Thus, whereas very young and slow waves affect the atmospheric flow similar to rigid roughness elements, with the occurrence of longer waves, an entirely different mechanism gains successively more importance and dynamical coupling with the atmospheric turbulence occurs. It may be speculated that the often observed kink in the wind profile represents the upper bound of a wave‐boundary‐layer, which is thus an order of magnitude deeper than predicted and observed during growing sea conditions.
Scaling in long term data sets of geomagnetic indices and solar wind ϵ as seen by WIND spacecraft
Authors: Hnat B. , Chapman S. C. , Rowlands G. , Watkins N. W. , Freeman M. P.
Published: November 2003

We study scaling in fluctuations of the geomagnetic indices (AE, AU, and AL) that provide a measure of magnetospheric activity and of the ϵ parameter which is a measure of the solar wind driver. Generalized structure function (GSF) analysis shows that fluctuations exhibit self‐similar scaling up to about 1 hour for the AU index and about 2 hours for AL, AE and ϵ when the most extreme fluctuations over 10 standard deviations are excluded. The scaling exponents of the GSF are found to be similar for the three AE indices, and to differ significantly from that of ϵ. This is corroborated by direct comparison of their rescaled probability density functions.
Thermal diffusivity of olivine single‐crystals and polycrystalline aggregates at ambient conditions—a comparison
Authors: Gibert Benoit , Schilling Frank R. , Tommasi Andréa , Mainprice David
Published: November 2003

Heat transfer is a key process for the mantle dynamics. However, analysis of experimental data on thermal transport properties of upper mantle materials highlights a large scatter of absolute values of thermal diffusivity. In particular, conduction of heat in single crystals is systematically higher than in polycrystalline samples. Here we present new thermal diffusivity measurements on San Carlos olivine single crystals and mantle rocks at 300K. Measured components of the olivine thermal diffusivity tensor along the [100], [010], and [001] directions are 2.73, 1.70, and 2.49 mm2. s−1, respectively. Measurements of thermal diffusivity of peridotites as a function of structural orientation show absolute values and anisotropy in good agreement with those predicted by petrophysical models based on the crystal preferred orientation of olivine and the above thermal diffusivity tensor. This suggests that the upper mantle thermal diffusivity is up to 50% higher than indicated by previous measurements on mantle rocks.
Transport reversals at Taiwan Strait during October and November 1999
Authors: Ko D. S. , Preller R. H. , Jacobs G. A. , Tang T. Y. , Lin S. F.
Published: November 2003

The observed transport reversals at Taiwan Strait during October and November 1999 are examined by analytic solutions, a numerical ocean model, and the prediction from a real‐time, North Pacific Ocean, data‐assimilating model. Wind stress explains a majority of the transport reversals. The reversals are forced by a combination of the local wind and the remote wind in the Yellow and East China Seas. The connection between the Yellow and East China Seas wind stress and transport reversals at Taiwan Strait is provided by coastally trapped waves. The waves are generated by the northerly winter wind bursts in the Yellow Sea and are enhanced in the East China Sea by alongshore northerly wind.
Geographic, terrestrial and aquatic factors: which most influence the structure of stream fish assemblages in the midwestern United States?
Authors: Marsh‐Matthews E. , Matthews W. J.
Published: November 2003

Abstract – Effects of environmental or landscape factors on species composition, species richness and complexity of fish assemblages were examined using our collections of fish from 65 sites on streams in 13 drainages across the midwestern United States. Effects of environmental factors were examined at three scales: broad geographic factors included drainage, latitude, and longitude; local terrestrial factors included features of the riparian zone adjacent to the collecting site as well as local climate and land use; within‐stream aquatic factors related to structure and hydrology of the stream reach sampled. Each assemblage property was examined for its relationship to factors at each scale separately, and then for relative importance of all factors found to be significant in the separate analyses. Assemblage composition (summarized as sample scores on two axes of a detrended correspondence analysis) varied significantly as a function of factors at all three scales when each scale was considered separately. With simultaneous consideration of all scales, however, only broad geographic factors (particularly latitude) and local terrestrial factors explained significant variation in assemblage composition. Species richness (the number of species we captured) was explained by longitude and within‐stream aquatic factors both when considered separately and together. Assemblage complexity (quantified as slope of relative abundance versus rank abundance) was only related to within‐stream aquatic factors. Assemblage composition and emergent assemblage properties (richness and complexity), therefore, were explained by factors acting at different scales. The total variation explained for assemblage composition was much greater than that explained for emergent assemblage properties, suggesting that assemblage composition may vary more as a function of environmental and landscape factors than do species richness and complexity.NOTE
Discharge variability and the development of predictive models relating stream fish assemblage structure to habitat in northeastern Australia
Authors: Pusey B. J. , Kennard M. J. , Arthington A. H.
Published: November 2003

Abstract – We developed classification/multiple discriminant analysis models to predict fish assemblage structure and tested whether the predictive power of these models varied with discharge variability. Models developed for assemblages characterized by the density of component species for two rivers with low discharge variability had better predictive power than did models developed for two rivers of higher variability. Similar distinction between rivers of differing flow variability was not evident for models based on assemblages characterized by the presence or absence of component species. Factors such as the within‐river level of beta diversity, location of study sites relative to the river mouth and the degree of covariation in species' occurrence appeared important determinants of predictive power in these models. Randomization tests (Mantel tests) were used to determine the degree of association between site by site association matrices generated for fish assemblage structure (both density and presence/absence) and habitat structure (catchment, physical, microhabitat or a combination). This approach revealed that in most cases, catchment‐related variables explained almost as much of the variation in assemblage structure as variables related to in‐stream habitat structure and that greater association was detected for comparisons based on presence/absence rather than density data. The addition of in‐stream habitat variables to catchment‐related variables usually resulted in explaining the greatest amount of variation. These data suggest that most of the structure observed in the fish assemblages of the study rivers was a result of the effect of regional or catchment factors in determining which species were present at an individual site and that local factors were then important in determining the abundance of the component species. It is at this level that the effects of regional differences in discharge variability were expressed. Although significantly different from random for all comparisons, Mantel's tests revealed that a substantial amount of variation in the fish assemblage data sets could not be explained by the abiotic (habitat) data sets. It is suggested that the assemblages in question did not represent unit discrete assemblages but were composed of species varying along individual environmental gradients. Predictive models may be better achieved by modelling the distribution and abundance of individual species rather than assemblages.NOTE
Metapopulations and salmonids: a synthesis of life history patterns and empirical observations
Authors: Rieman B. E. , Dunham J. B.
Published: November 2003

Abstract – Metapopulation theory has attracted considerable interest with reference to the salmonids. There has been little empirical evidence, however, to guide the evaluation or application of metapopulation concepts. From knowledge of salmonid life histories and our own work with bull trout (Salvelinus confluentus), Lahontan cutthroat trout (Oncorhynchus clarki henshawi) and westslope cutthroat trout (Oncorhynchus clarki lewisi), we suggest that simple generalizations of salmonid metapopulations are inappropriate. Although spatial structuring and dispersal mechanisms are evident, the relevance of extinction and colonization processes are likely to vary with life history, species, scale, and landscape. Understanding dispersal, the role of suitable but unoccupied habitats, and the potential for extinction debts in non‐equilibrium metapopulations are key issues. With regard to conservation of salmonids, we suggest that efforts to understand and conserve key processes likely to influence the persistence of populations or metapopulations will be more successful than efforts to design minimal habitat reserves based on metapopulation theory.NOTE