bluuebunny/crossref_metadata_2025_split huggingface dataset:
Web crawling ethics revisited: Cost, privacy, and denial of service
Authors: Thelwall Mike , Stuart David 
Published: September 2006

AbstractEthical aspects of the employment of Web crawlers for information science research and other contexts are reviewed. The difference between legal and ethical uses of communications technologies is emphasized as well as the changing boundary between ethical and unethical conduct. A review of the potential impacts on Web site owners is used to underpin a new framework for ethical crawling, and it is argued that delicate human judgment is required for each individual case, with verdicts likely to change over time. Decisions can be based upon an approximate cost‐benefit analysis, but it is crucial that crawler owners find out about the technological issues affecting the owners of the sites being crawled in order to produce an informed assessment.
Elementdecken bei nicht vorwiegend ruhender Belastung. Hinweise zur Anwendung von Gitterträgern nach Zulassung
Authors: Furche Johannes , Bauermeister Ulrich 
Published: September 2006

AbstractElementdecken aus vorgefertigten Stahlbetonplatten mit Gitterträgern und aufbetonierter Ortbetonschicht werden seit Jahren auch bei nicht vorwiegend ruhender Belastung eingesetzt. Die Anwendungsgrenzen und Bemessungsregeln für diese Anwendung wurden aus Bauteilversuchen abgeleitet. Die Regelungen innerhalb bauaufsichtlicher Zulassungen für Gitterträger wurden mit Einführung der neuen DIN 1045‐1 an das neue Bemessungskonzept angepaßt. Zusätzlich zu den Regelungen, welche für reine Ortbetonkonstruktionen gelten, ist eine Querkraftobergrenze einzuhalten und der Ermüdungsnachweis für die Gitterträgerdiagonalen zu führen. Dabei ist das Querkraftmodell mit variabler Druckstrebenneigung zu berücksichtigen. Die Herleitung der neuen Zulassungsregelungen wird erläutert und eine Bemessungshilfe vorgestellt.
Teilversagen eines Rohwaschkohlebunkers – Ursachen und Schlußfolgerungen
Authors: Fastabend Michael , Kähler Armin , Schäfers Tobias , Reißmann Frank 
Published: September 2006

AbstractDer nach 30 Jahren Betrieb zu verzeichnende Einsturz einer Seitenwand eines Rohwaschkohlebunkers gab Anlaß zur Überprüfung von gleichartigen Bauwerken auf der Grundlage der Schadensursachen. Bedingt durch hochmechanisierte Abbaumethoden in den Steinkohlebergwerken, haben sich die bodenmechanischen Randbedingungen des Füllgutes geändert. Ebenso liegen mittlerweile vertiefte Erkenntnisse über die anzunehmende Erddrucktheorie vor, die bei derart steifen Bauwerken stets die Berücksichtigung zumindest eines Anteils des Erdruhedrucks notwendig machen.
Querkraftmodell für Bauteile aus Normalbeton und Hochleistungsbeton
Authors: Hegger Josef , Görtz Stephan 
Published: September 2006

AbstractZur Überprüfung der aktuellen Querkraftmodelle für Bauteile aus Normal‐ und Hochleistungsbeton wurden 31 Versuche und begleitende theoretische Untersuchungen durchgeführt. Aufbauend auf den Forschungsergebnissen wird ein Ingenieurmodell entwickelt und an einer Versuchsdatenbank verifiziert. Ausgangsbasis ist das Modell nach DIN 1045‐1, für das in einigen Punkten Vorschläge zur Modifizierung erarbeitet werden.
Fundamentplatten aus Stahlbeton und Stahlfaserbeton. Experimentelle Untersuchungen zur Gebrauchstauglichkeit und Tragfähigkeit
Authors: Gossla Ulrich , Stormberg Michael 
Published: September 2006

AbstractEin‐ und Mehrfamilienhäuser werden zunehmend statt auf Streifenfundamenten auf Fundamentplatten gegründet. Vorteile ergeben sich neben der wirtschaftlicheren Ausführung der Aushubarbeiten durch die einfachere Herstellung der Platte. Bei der Ausführung als Stahlfaserbetonplatte ergeben sich besonders wirtschaftliche Lösungen dann, wenn an die Gebrauchstauglichkeit keine besonderen Anforderungen wie Wasserdichtheit oder Rißbreitenbeschränkung gestellt werden.An der Fachhochschule Aachen wurden vergleichende experimentelle Untersuchungen an Bodenplatten aus Beton, Stahlbeton und Stahlfaserbeton unter Lastbeanspruchung durchgeführt. Es konnte nachgewiesen werden, daß Stahlfaserbeton für Fundamentplatten ein geeigneter Werkstoff ist, wenn Mindestanforderungen an die Steifigkeit des Bodens eingehalten werden. Bei erhöhten Anforderungen an die Gebrauchstauglichkeit werden Stahlbeton oder Kombinationen aus Stahlfaserbeton und Stahlbeton als sinnvoll erachtet, wenn diese auf Basis einer elastischen Schnittgrößenermittlung bemessen werden.
Berechnung der mittleren Höchstlast von Schraubankern in gerissenem und ungerissenem Beton
Authors: Küenzlen Jürgen H. R. 
Published: September 2006

AbstractDas Tragverhalten von Befestigungselementen wie Metall‐ und Verbunddübel wurde in den vergangenen Jahrzehnten in zahlreichen Forschungsarbeiten behandelt. Untersuchungen mit Schraubankern wurden bisher kaum durchgeführt. Ziel des Forschungsvorhabens war es, das Trag‐ und Versagensverhalten von Schraubankern zu untersuchen und über ein Bemessungskonzept die Umsetzung der Forschungsergebnisse in die Praxis zu ermöglichen. In der vorliegenden Veröffentlichung werden Berechnungsgleichungen für die mittlere Höchstlast von Schraubankern unter zentrischer Zugbelastung bei Betrachtung von Eck‐ und Randeinfluß, Gruppenbefestigungen, Gewindelänge und gerissenem Beton zusammengefaßt.
Vorgespannte Decken ohne schlaffe Bewehrung
Authors: Ambro Sebastian Zoran , Burtscher Stefan L. , Loeffler Veronika , Kollegger Johann 
Published: September 2006

AbstractDie Vorspannung von Bauwerken und Bauteilen ist eine Bauweise, die in den 30er Jahren des 20. Jahrhunderts entwickelt wurde. Durch diese Bauweise werden die Beanspruchungen und Verformungen von Bauwerken gezielt beeinflußt. Man erkannte bereits damals, daß durch das Vorspannen die Rißbildung im Beton reduziert bzw. vermieden werden kann. Diese Bauweise wurde besonders im Brückenbau mit großem Erfolg angewandt. Obwohl die Vorteile der Vorspannung im Hochbau in einigen Ländern wie z. B. in den USA und Australien sehr effizient genutzt werden, hat sich die Anwendung der Vorspannung im Hochbau in Europa bis jetzt noch nicht durchgesetzt. In Australien werden vorgespannte Decken ohne schlaffe Bewehrung schon seit längerem erfolgreich eingesetzt und die hierfür notwendigen Bemessungsregeln sind im AS 3600 (Australian Standard) festgehalten. Im Unterschied zu den USA, wo die Vorspannung ohne Verbund bevorzugt wird, werden in Australien nur Spannglieder mit Verbund verwendet.Dieser Beitrag zeigt, daß bei vorgespannten Decken auf die schlaffe Bewehrung verzichtet werden kann und beschreibt die Entwicklung einer Bauweise, die es ermöglicht, Betondecken im Hochbau effizienter und wirtschaftlicher zu bauen.
Schiffsanprall an die Eisenbahnbrücke in Krems. Erstmalige Anwendung des neuen Eurocode EN 1991‐1‐7 für Außergewöhnliche Einwirkungen
Authors: Simandl Thomas , Glatzl Johann , Schweighofer Bernhard , Blovsky Stefan 
Published: September 2006

AbstractAm 17. Dezember 2005 wurde der Mittelpfeiler der Kremser Eisenbahnbrücke um ca. 3.40 Uhr von einem stromaufwärts auf der Donau fahrenden Schubverband frontal angefahren und schwer beschädigt. Der Pfeilerschaft – ein Granitmauerwerk aus der Bahnbauzeit 1889 – wurde auf Höhe des Wasserspiegels abgeschert und 2, 17 m flußaufwärts und 10 cm in Richtung Bahnachse verschoben. Sowohl der Bahnverkehr als auch der neben dem Pfeiler verlaufende Schiffsverkehr mußte gesperrt, die über die Brücke verlaufenden Energieträger (Gashochdruckleitung, Starkstromleitung, Datenleitungen etc.) mußten umgelegt bzw. außer Betrieb gesetzt werden.Um die Sicherheit für die Bahn‐ und Schiffskunden zu erhöhen, wird sowohl der beschädigte Pfeiler saniert, als auch die anderen Flußpfeiler entsprechend des Eurocodes prEN 1991‐1‐7 verstärkt. Dieser Bericht beschreibt das Schadensereignis, die Rahmenbedingungen der Planung und die Anwendung des neuen Eurocodes prEN 1991‐1‐7. Diese Projektierung mußte zufolge der hohen Ausfallskosten unter enormen Zeitdruck erfolgen.
Increased heterologous protein production by Saccharomyces cerevisiae growing on ethanol as sole carbon source
Authors: van de Laar Teun , Visser Chris , Holster Marianne , López Cristina García , Kreuning Dennes , Sierkstra Laurens , Lindner Nigel , Verrips Theo 
Published: September 2006

AbstractSaccharomyces cerevisiae is a widely used host organism for the production of heterologous proteins, often cultivated in glucose‐based fed‐batch processes. This production system however has many factors limiting the productivity, mainly towards the end of the fermentation. For the optimised production of a Camelid antibody fragment this process was evaluated. In shake flask cultivations, it was found that ethanol has a strong effect on productivity increase and therefore glucose and ethanol fed‐batch fermentations were compared. It appeared that specific heterologous protein production was up to five times higher in the ethanol cultivation and could be further optimised. Then the key characteristics of ethanol fed‐batch fermentations such as growth rate and specific production were determined under ethanol limitation and accumulation and growth limiting conditions in the final phase of the process. It appeared that an optimal production process should have an ethanol accumulation throughout the feed phase of approximately 1% v/v in the broth and that production remains very efficient even in the last phase of the process. This productivity increase on ethanol versus glucose was also proven for several other Camelid antibody fragments some of which were heavily impaired in secretion on glucose, but very well produced on ethanol. This leads to the suggestion that the ethanol effect on improved heterologous protein production is linked to a stress response and folding and secretion efficiency. Biotechnol. Bioeng. 2007;96: 483–494. © 2006 Wiley Periodicals, Inc.
Codon optimized Thermobifida fusca hydrolase secreted by Bacillus megaterium
Authors: Yang Yang , Malten Marco , Grote Andreas , Jahn Dieter , Deckwer Wolf‐Dieter 
Published: September 2006

AbstractProduction and secretion of a 28,172 Da hydrolase from Thermobifida fusca (TFH) in Bacillus megaterium MS941 and WH323 was investigated in shake flask and pH controlled bioreactors. Successful production of heterologous TFH was achieved by adapting the original tfh gene to the optimal codon usage of B. megaterium. A codon adaption index close to one was reached. The codon optimized tfh was cloned into an open reading frame with DNA sequence for the N‐terminal signal peptide of B. megaterium lipase A and a C‐terminal His6‐tag, all under the control of a xylose inducible promoter. Successful TFH production and secretion were observed using batch reactor cultivations with complex medium. Expression of the tfh gene from the PxylA promoter and secretion of produced TFH were compared in detail to batch reactor cultivations with semi‐defined growth medium. For the first time, significant TFH secretion was achieved using a semi‐defined medium in glucose limited fed batch cultivations yielding 10‐fold higher cell densities compared to LB medium cultivation. Comparable volumetric TFH activities were obtained for both cultivation strategies. Surprisingly, measured specific TFH activities exhibited drastic discrepancies between preparations from LB and semi‐defined medium grown B. megaterium. TFH recovery by Ni‐chelate affinity chromatography resulted in higher purification factors when LB medium was used. These results indicated that secreted TFH is favorably produced by batch cultures of B. megaterium WH323 in LB medium. Biotechnol. Bioeng. 2007;96:780–794. © 2006 Wiley Periodicals, Inc.
Efficient regeneration of NADPH using an engineered phosphite dehydrogenase
Authors: Johannes Tyler W. , Woodyer Ryan D. , Zhao Huimin 
Published: September 2006

AbstractThe in situ regeneration of reduced nicotinamide cofactors (NAD(P)H) is necessary for practical synthesis of many important chemicals. Here, we report the engineering of a highly stable and active mutant phosphite dehydrogenase (12x‐A176R PTDH) from Pseudomonas stutzeri and evaluation of its potential as an effective NADPH regeneration system in an enzyme membrane reactor. Two practically important enzymatic reactions including xylose reductase‐catalyzed xylitol synthesis and alcohol dehydrogenase‐catalyzed (R)‐phenylethanol synthesis were used as model systems, and the mutant PTDH was directly compared to the commercially available NADP+‐specific Pseudomonas sp. 101 formate dehydrogenase (mut Pse‐FDH) that is widely used for NADPH regeneration. In both model reactions, the two regeneration enzymes showed similar rates of enzyme activity loss; however, the mutant PTDH showed higher substrate conversion and higher total turnover numbers for NADP+ than mut Pse‐FDH. The space‐time yields of the product with the mutant PTDH were also up to fourfold higher than those with mut Pse‐FDH. In particular, a space‐time yield of 230 g L−1 d−1 xylitol was obtained with the mutant PTDH using a charged nanofiltration membrane, representing the highest productivity compared to other existing biological processes for xylitol synthesis based on yeast D‐xylose converting strains or similar in vitro enzyme membrane reactor systems. Biotechnol. Bioeng. 2007;96: 18–26. © 2006 Wiley Periodicals, Inc.
Limits to productivity of the algaPleurochrysis carterae(Haptophyta) grown in outdoor raceway ponds
Authors: Moheimani, Navid Reza , Borowitzka Michael A. 
Published: September 2006

AbstractThis study examined the effects of oxygen concentration, pond temperature and irradiance on productivity and CaCO3formation of the coccolith‐forming alga,Pleurochrysis carteraeCCMP647 grown in semi‐continuous culture in outdoor raceway ponds. During the day the oxygen content of the pond increases markedly andP. carteraephotosynthesis is inhibited by these high O2concentrations with the inhibition increasing with increasing temperature. The high irradiance outdoors presents less of a problem to photosynthesis and productivity as the algae can acclimate well to high irradiances over a period of several weeks. Pond depth also effects productivity and this effect varies with season. During autumn, productivities were highest at depths of 13 to 16 cm, and decreased when the depth was increased. During summer productivity was much lower at 13 cm pond depth and increased when the depth was increased to 16, 18 and 21 cm. Heating the ponds in the morning by approximately 3 to 5°C improves productivity by 11%–21%, presumably because this allows the algae to photosynthesise faster in the conditions of low [O2] which occur in the early morning. Biotechnol. Bioeng. 2007;96: 27–36. © 2006 Wiley Periodicals, Inc.
Chemometric analysis of in‐line multi‐wavelength fluorescence measurements obtained during cultivations with a lipase producing Aspergillus oryzae strain
Authors: Haack Martin B. , Lantz Anna Eliasson , Mortensen Peter P. , Olsson Lisbeth 
Published: September 2006

AbstractThe filamentous fungus, Aspergillus oryzae, was cultivated in batch and fed‐batch cultivations in order to investigate the use of multi‐wavelength fluorescence for monitoring course of events during filamentous fungi cultivations. The A. oryzae strain applied expressed a fungal lipase from Thermomyces lanuginosus. Spectra of multi‐wavelength fluorescence were collected every 5 min with the BioView® system (DELTA, Denmark) and both explorative and predictive models, correlating the fluorescence data with cell mass and lipase activity, were built. During the cultivations, A. oryzae displayed dispersed hyphal growth and under these conditions no fouling of the multi‐wavelength fluorescence sensor was observed. The scores of a parallel factor analysis (PARAFAC) model, based on the fluorescence spectra, gave clear evidence of, for example, the on‐set of the feeding phase. The predictive models, estimating the cell mass, showed correlations between 0.73 and 0.97 with root mean square error of cross validation (RMSECV) values between 1.48 and 0.77 g · kg−1. A model estimating the lipase activity was also constructed for the fed‐batch cultivations with a correlation of 0.93. The results presented here clearly show that multi‐wavelength fluorescence is a useful tool for monitoring fed‐batch cultivations of filamentous fungi. Biotechnol. Bioeng. 2007;96:904–913. © 2006 Wiley Periodicals, Inc.
Electrochemical screening of recombinant protein solubility in Escherichia coli using scanning electrochemical microscopy (SECM)
Authors: Nagamine Kuniaki , Onodera Shiho , Kurihara Ai , Yasukawa Tomoyuki , Shiku Hitoshi , Asano Ryutaro , Kumagai Izumi , Matsue Tomokazu 
Published: September 2006

AbstractA microbial array chip with collagen gel spots entrapping living Escherichia coli (E. coli) DH5α was applied for the screening of recombinant protein solubilities. The α‐fragment of β‐galactosidase (βGal) was fused to the target protein, namely, maltose‐binding protein (MBP), to monitor the solubility of MBP. Scanning electrochemical microscopy (SECM) was used to detect the release of p‐aminophenol from E. coli cells catalyzed by intracellular βGal. Comparison of the SECM‐based method with the Western blotting‐based method indicated that the current response obtained using SECM increased with an increase in the βGal activity and therefore, with the soluble fraction of MBP in the host cells. Biotechnol. Bioeng. 2007;96:1008–1013. © 2006 Wiley Periodicals, Inc.
Application of cellulases from an alkalothermophilic Thermomonospora sp. in biopolishing of denims
Authors: Anish Ramakrishnan , Rahman Mohammad Safikur , Rao Mala 
Published: September 2006

AbstractUse of cellulase for denim washing is a standard eco‐friendly technique to achieve desirable appearance and softness for cotton fabrics and denims. But enzymatic washing of denim till date involved acid cellulase (Trichoderma reesei) and neutral cellulase (Humicola isolens) the use of which has a drawback of backstaining of the indigo dye on to the fabric. Though it has been suggested that pH is a major factor in controlling backstaining there are no reports on use of cellulase under alkaline conditions for denim washing. In this study for the first time an alkali stable endoglucanase from alkalothermophilic Thermomonospora sp. (T‐EG) has been used for denim biofinishing under alkaline conditions. T‐EG is effective in removing hairiness with negligible weight loss and imparting softness to the fabric. Higher abrasive activity with lower backstaining was a preferred property for denim biofinishing exhibited by T‐EG. The activities were comparable to acid and neutral cellulases that are being regularly used. The enzyme was also effective under non‐buffering conditions which is an added advantage for use in textile industry. A probable mechanism of enzymatic finishing of cotton fabric has been represented based on the unique properties of T‐EG. Biotechnol. Bioeng. 2007;96: 48–56. © 2006 Wiley Periodicals, Inc.
Quantitative real‐time PCR for rapid and accurate titration of recombinant baculovirus particles
Authors: Hitchman Richard B. , Siaterli Evangelia A. , Nixon Clare P. , King Linda A. 
Published: September 2006

AbstractWe describe the use of quantitative PCR (QPCR) to titer recombinant baculoviruses. Custom primers and probe were designed to gp64 and used to calculate a standard curve of QPCR derived titers from dilutions of a previously titrated baculovirus stock. Each dilution was titrated by both plaque assay and QPCR, producing a consistent and reproducible inverse relationship between CT and plaque forming units per milliliter. No significant difference was observed between titers produced by QPCR and plaque assay for 12 recombinant viruses, confirming the validity of this technique as a rapid and accurate method of baculovirus titration. Biotechnol. Bioeng. 2007;96:810–814. © 2006 Wiley Periodicals, Inc.
Methodological analysis for determination of enzymatic digestibility of cellulosic materials
Authors: Zhang Y.‐H. Percival , Schell Daniel J. , McMillan James D. 
Published: September 2006

AbstractAccurate measurement of enzymatic cellulose digestibility (X) is important in evaluating the efficiency of lignocellulose pretreatment technologies, assessing the performance of reconstituted cellulase mixtures, and conducting economic analysis for biorefinery processes. We analyzed the effect of sugars contained in enzymes solutions, usually added as a preservative, and random measurement errors on the accuracy of X calculated by various methods. The analysis suggests that exogenous sugars at levels measured in several commercial enzyme preparations significantly bias the results and that this error should be minimized by accounting for these sugars in the calculation of X. Additionally, a method of calculating X equating the ratio of the soluble glucose equivalent in the liquid phase after hydrolysis to the sum of the soluble glucose equivalent in the liquid phase and the insoluble glucose equivalent in the residual solid after hydrolysis was found to be the most accurate, particularly at high conversion levels (>ca. 50%). Biotechnol. Bioeng. 2007;96: 188–194. © 2006 Wiley Periodicals, Inc.
Effect of solvent concentration on the extraction kinetics and diffusivity of Cyclosporin A in the fungus Tolypocladium inflatum
Authors: Ly May , Margaritis Argyrios , Jajuee Babak 
Published: September 2006

AbstractThe kinetics of solid‐liquid extraction and extraction yields of the immunosuppressant drug Cyclosporin A (CyA) from the mycelia of Tolypocladium inflatum were examined in this study. A 2 L stirred, baffled vessel was used to extract CyA from wet mycelia mass. Three different organic solvents were used, namely, methanol, acetone, and isopropanol at different concentrations in aqueous mixtures at room temperature. It was found that the best solvent was acetone at 50% v/v concentration achieving 100% extraction of CyA from the mycelia of T. inflatum. Although acetone proved to be the better solvent for CyA extraction, further studies were performed using methanol. A linear relationship was found between extraction yield of CyA and methanol concentration with 100% CyA extraction at 90% v/v methanol. The partition coefficients of CyA between the solid mycelia phase and the aqueous solvent phase were found to decrease exponentially with increasing methanol concentration. A liquid extraction model was developed based on the diffusion equation to correlate the kinetic data of CyA extraction from the solid mycelia of T. inflatum. Non‐linear regression analysis of experimental data was used with the diffusion equation in order to calculate the effective diffusivities of CyA in the mycelia of T. inflatum. For all three organic solvents used, the effective diffusivities of CyA were found to be between 4.41 × 10−15 and 6.18 × 10−14 m2/s. This is the first time CyA effective diffusivities in T. inflatum are reported in the literature. Biotechnol. Bioeng. 2007;96: 67–79. © 2006 Wiley Periodicals, Inc.