bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prüfung der Funktion von Dichtungskontrollsystemen für Konvektionssperren in Deponieoberflächenabdichtungen
Authors: Wöhlecke Andreas , Müller Werner 
Published: December 2012

AbstractMit Dichtungskontrollsystemen (DKS) werden Konvektionssperren in Oberflächenabdichtungssystemen von Deponien kontrolliert. Die Funktionsfähigkeit eines eingebauten DKS muss in jedem Projekt zuvor überprüft werden. Diese projektspezifische Funktionsprüfung des DKS selbst wird am Beispiel der Verwendung mit einer Kunststoffdichtungsbahn (KDB) diskutiert. Der grundsätzliche Aufbau, die zugrunde liegenden Messprinzipien und das Ziel der Prüfung werden vorgestellt. Die Anforderungen an die nach der Deponieverordnung (DepV) zugelassenen Systeme hinsichtlich Betrieb, Leitungsfähigkeit und Konstruktion werden beschrieben. Dabei wird auf die Vorgaben der Richtlinie, die einer Zulassung zugrunde liegt, eingegangen. Das mögliche Vorgehen bei der projektspezifischen Kontrollprüfung im Hinblick auf Aspekte wie Vorgehensweise, Zeitpunkt und Randbedingungen sowie äußere Einflussfaktoren werden diskutiert.Performance test of leak detection systems for tight barriers in landfill coversLeak detection systems (LDS) are used to control tight barriers in landfill cover systems. However, the efficiency of the installed LDS itself has to be verified in every landfill construction project. As an example the efficiency test for LDS used in connection with geomembranes is discussed in detail. The basic principles, the measuring techniques and objectives of the efficiency testing are described. The requirements for a certification of LDS under the terms of the new German landfill ordinance with regard to operation, capability and design are listed. The conditions necessary for a certification of LDS are introduced. Possible project related efficiency testing procedures with respect to the scope, time of convenience, general conditions as well as external influencing factors are discussed.
Zugelemente aus CFK und ihre Verankerungen
Authors: Schlaich Mike , Zwingmann Bernd , Liu Yue , Goller Ralf 
Published: December 2012

AbstractDer Fortschritt im Bauingenieurwesen ist eng mit dem Aufkommen neuer Materialien verknüpft. Werkstoffe wie Eisen und Stahl, der moderne Stahlbeton und der Spannbetonbau haben die Baukultur seit dem Beginn der Industrialisierung maßgeblich verändert. Seit den 1990‐er Jahren werden mit Kohlenstofffasern verstärkte Kunststoffe (CFK) für eine steigende Anzahl von Anwendungen im Bauwesen verwendet.Im Artikel finden sich neben einer Einleitung zu den Eigenschaften dieses Hochleistungswerkstoffs eine Zusammenstellung des Entwicklungsstands von Zugelementen aus CFK und den dazugehörigen Verankerungen. Zugelemente aus CFK haben großes Potenzial für leichte und weitgespannte Konstruktionen wie Seilbrücken und Dachkonstruktionen. Daher wird an der TU Berlin auf dem Gebiet der werkstoffgerechten Ausbildung von CFK‐Zugelementen geforscht.CFRP Tension Elements and Their AnchoragesProgress in civil engineering is highly connected to the appearance of new materials. The materials iron and steel, reinforced concrete and prestressed concrete have been influencing the building culture since the beginning of industrialization. From the 1990s carbon fiber reinforced plastics (CFRP) experience an increasing use for structural application.This article gives an introduction to the properties of this high‐performance material and presents the state of the art of CFRP tension elements with their corresponding anchorages. CRFP tension elements have high potential for lightweight and wide spread constructions like cable bridges and suspended roofs. Therefore the appropriate design regarding the material of CFRP tension elements is investigated at the Technical University of Berlin.
Zum Einfluss der Belastungsfrequenz und der Spannungsgeschwindigkeit auf die Ermüdungsfestigkeit von Beton
Authors: Schneider Sebastian , Vöcker Daniela , Marx Steffen 
Published: December 2012

AbstractDie Ermüdungseigenschaften von Beton werden in den meisten Fällen mithilfe sogenannter Einstufenversuche untersucht. Dabei wird eine Betonprobe mit einer konstanten Mittellast beaufschlagt, der nachfolgend eine oszillierende Schwingbeanspruchung überlagert wird. Um den Zeitaufwand für diese Versuche zu minimieren, wird eine möglichst hohe Belastungsfrequenz angestrebt. Allerdings wurde durch einige Forschungsarbeiten deutlich, dass die Belastungsfrequenz einen Einfluss auf die ertragbaren Lastwechsel von Beton hat. Die Auswertung von in der Literatur dokumentierten Versuchen ergab, dass die Ermüdungsfestigkeit, analog zur Betondruckfestigkeit bei einmaliger Belastung, scheinbar maßgeblich von der Dehngeschwindigkeit abhängt. Diese Erkenntnis erlaubt zum einen eine relativ einfache Umrechnung von Versuchsergebnissen, die mit hohen Prüffrequenzen gewonnen wurden. Zum anderen kann damit eine Grenzfrequenz für Ermüdungsversuche in Abhängigkeit von der Schwingbreite bestimmt werden.About loading frequency and stress rate influences on fatigue strength of concreteThe fatigue behavior of concrete is mostly studied on the basis of constant amplitude tests. Constant maximum and minimum stresses are applied to concrete specimens during these tests. In addition, high loading frequencies are used in order to minimize the test duration. However, the loading frequency has an influence on the number of load cycles to failure. A study of fatigue tests documented in the literature has shown that the fatigue strength of concrete depends on the strain rate like the compressive strength due to single loading. With this consideration it becomes possible to convert test results with different loading frequencies into each other. Furthermore, a frequency limit can be determined depending on the stress range.
Analyse der durch Frost‐ und Frost‐Tausalz‐Wechsel induzierten Schädigungsprozesse in Beton
Authors: Weise Frank , Maier Bärbel , Ehrig Karsten 
Published: December 2012

AbstractZur Beurteilung des Frost‐ bzw. Frost‐Tausalz‐Widerstandes des Betons finden normativ als Alternativverfahren das CIF‐ bzw. CDF‐Verfahren Anwendung. Als Beurteilungskriterium für den inneren Schädigungsprozess werden bisher ausschließlich die Änderung der Ultraschalllaufzeit und die Massezunahme durch Frostsaugen herangezogen. Die Bewertung des äußeren Schädigungsprozesses hingegen erfolgt ausschließlich mittels einer vergleichenden visuellen Beurteilung der Prüffläche und der Ermittlung der Abwitterungsmasse. Allen bisher angewandten inneren und äußeren Schädigungsindikatoren ist gemeinsam, dass ihre Aussagefähigkeit durch eine fehlende ortsaufgelöste Quantifizierung des Schädigungsprozesses eingeschränkt ist.Der Beitrag zeigt, dass dieser Nachteil durch den Einsatz neuartiger innovativer Prüftechniken weitestgehend beseitigt werden kann. So wird vergleichend zu der normativen Ultraschallprüfung aufgezeigt, dass der Einsatz der Röntgen 3D‐Computertomografie eine zerstörungsfreie zeitliche und räumliche Analyse des inneren Rissbildungsprozesses beim CIF‐Verfahren ermöglicht. Außerdem wurde durch die Anwendung der Photogrammetrie die äußere Abwitterung der Prüffläche beim CDF‐Verfahren erstmalig ortsaufgelöst quantifiziert.Analysis of damage processes in concrete induced by freeze thaw or freeze thaw salt cycles. Application of innovative measurement techniquesCIF‐ and CDF‐test are alternatively applied for the standardized assessment of freeze and freeze de‐icing salt resistance of concrete. Up to now the increase of ultrasonic time of flight and mass induced by freeze suction are the only criteria for the assessment of internal damage process. The evaluation of the external damage process is currently realised by visual comparison of test surfaces and the determination of the scaling mass. The significance of these internal and external damage indicators is limited due to the lack of spatially‐resolved quantifications of the damage process.This contribution shows that this disadvantage can be overcome by the application of innovative test methods. In contrast to normative ultrasound test methods, the application of X‐ray 3D computed tomography allows a non‐destructive temporal and spatial analysis of the internal crack formation process during the CIF‐test. For the first time, a spatially‐resolved quantification of the scaling of the test surface has been performed by photogrammetry.
Leichte Stahlbetontragwerke mit großen Spannweiten
Authors: van Berkel Ben , Steller Frank 
Published: December 2012

AbstractDie offene transparente Bauweise des Zentrums für Virtuelles Engineering erforderte den Einsatz leichter Konstruktionen mit großen Spannweiten. Die Anforderungen an den Entwurf werden einleitend aus der Sicht des Architekten dargestellt. Anschließend werden die Schritte vom architektonischen zum konstruktiven Entwurf beschrieben. Auf die Erfahrungen mit den eingesetzten leichten Bauweisen wird ausführlich aus dem Blickwinkel des planenden Ingenieurs eingegangen.Centre for Virtual Engineering of the Fraunhofer Institute in Stuttgart‐Vaihingen. Light‐weight reinforced concrete structures with large spansThe opened and transparent construction of the Centre for Virtual Engineering required the application auf light‐weight structures with large spans. In the beginning the draft requirements are shown from the architect's viewpoint. Afterwards the steps from the architectural to the structural concept are described. In detail they dwell on the engineer's experience with the applied light‐weight constructions.
Patterns and predictive factors of complications after endoscopic retrograde cholangiopancreatography
Authors: Glomsaker T , Hoff G , Kvaløy J T , Søreide K , Aabakken L , Søreide J A 
Published: December 2012

Abstract

Background
With an increased use of magnetic resonance imaging, the indications for endoscopic retrograde cholangiopancreatography (ERCP) have changed. Consequently, the patterns and factors predictive of complications after ERCP performed during current routine clinical practice are not well known.

Methods
A prospective multicentre cohort study was undertaken in 11 Norwegian hospitals. Complications and mortality within 30 days after ERCP were analysed by univariable and multivariable regression analysis.

Results
There were 2808 ERCP procedures, of which 2573 (91·6 per cent) were therapeutic. More than half of the patients were aged 70 years or more. Common bile duct cannulation was achieved in 2557 procedures (91·1 per cent). Complications occurred in 327 (11·6 per cent) of the procedures, including cholangitis in 100 (3·6 per cent), pancreatitis in 88 (3·1 per cent), bleeding in 66 (2·4 per cent), perforation in 25 (0·9 per cent) and cardiovascular–respiratory events in 32 (1·1 per cent). In the multivariable regression analysis, older age, increasing American Society of Anesthesiologists fitness score, centre ERCP volumes of more than 150 procedures annually and precut sphincterotomy were predictive factors for severe complications. The overall 30-day mortality rate was 2·2 per cent (63 patients), with a procedure-related mortality rate of 1·4 per cent (39 patients). Malignancy was diagnosed in 46 (73 per cent) of the patients who died.

Conclusion
ERCP is a procedure with considerable risk for complications. Morbidity and mortality are related to patient age and co-morbidity, as well as hospital volume of ERCP procedures and the type of intervention.
Simultaneous determination of homocysteine, methionine and cysteine in maternal plasma after delivery by HPLC‐fluorescence detection with DBD‐F as a label
Authors: Wada Mitsuhiro , Hirose Maki , Kuroki Mana , Ikeda Rie , Sekitani Yui , Takamura Noboru , Kuroda Naotaka , Nakashima Kenichiro 
Published: December 2012

ABSTRACTAn HPLC‐fluorescence (FL) method for determination of sulfur‐containing amino acids such as homocysteine (Hcy), methionine (Met) and cysteine (Cys) in human plasma was developed. The sulfur‐containing amino acids were labeled with 4‐(N,N‐dimethylaminosulfonyl)‐7‐fluoro‐2,1,3‐benzoxadiazole (DBD‐F). Calibration curves in the range of 1–100 µm (Hcy and Met) and 5–500 µm (Cys) indicated good linearities (r ≥ 0.998). The limits of detection at a signal‐to‐noise ratio of 3 were 0.13 (Hcy), 0.02 (Met) and 0.11 µm (Cys), respectively. Acceptable results for accuracy and precision of intra‐ and inter‐day measurements were obtained. The results of Hcy and Cys obtained by the proposed method indicated good correlations with the conventional method (r > 0.911, n = 20). Furthermore, the method was applied to determination of the sulfur‐containing amino acids in maternal plasma (n = 200) after delivery. The concentrations of Hcy, Met and Cys as a median (inter quartile range, Q1 and Q3) were 5.37 (3.32–7.79) μm, 25.20 (20.10–31.06) μm and 147.25 (102.81–189.31) μm, respectively. Copyright © 2012 John Wiley & Sons, Ltd.
Enhanced protein stability through minimally invasive, direct, covalent, and site‐specific immobilization
Authors: Smith Mark T. , Wu Jeffrey C. , Varner Chad T. , Bundy Bradley C. 
Published: December 2012

AbstractBioconjugating protein to nonbiological surfaces is an essential component of many promising biotechnologies impacting diverse applications such as medical diagnostics, biocatalysis, biohazard detection, and proteomics. However, to enable the widespread economical use of immobilized‐protein technologies, long‐term stability, and reusability is essential. To enhance protein stability in harsh conditions, herein we report a minimally invasive and covalent bioconjugation that enables precise control of the immobilization location at potentially any surface‐accessible location where the incorporated unnatural amino acid does not impact protein structure and function. Specifically, the PRECISE system is introduced where a uniquely reactive unnatural amino acid was incorporated site‐specifically at a prespecified location in GFP using cell‐free protein synthesis. The GFP was then directly and covalently attached to superparamagnetic beads by the unnatural amino acid in a single click reaction. The immobilized GFP was probed for retained activity and stability under harsh conditions including freeze‐thaw cycling and incubation in urea at elevated temperatures. The immobilized GFP was more stable compared to unattached protein in all cases and for all durations observed. The enhanced stability of the immobilized protein is a promising step towards long‐term protein stability for biocatalysis and other immobilized‐protein applications. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013
Counter‐Rotating Spin‐Polarised Ring Currents in Odd‐Electron Carbocycles
Authors: Soncini Alessandro , Fowler Patrick W. 
Published: December 2012

AbstractWe propose a molecular‐orbital model to explain how majority and minority spins in odd‐π‐electron carbocycles sustain counter‐rotating magnetic‐field‐induced ring currents. The model is based on the ipsocentric approach to magnetic response, in which ring currents are dominated by frontier‐orbital contributions obeying angular‐momentum selection rules. Coupled unrestricted Hartree–Fock ab initio calculations of the ring‐current responses for singly charged benzene and planarised cyclo‐octatetraene ions confirm the predictions of the qualitative model, and are consistent with correlated MP2 spin‐polarised current calculations.
Einem Leib‐ und Magenfeind zum Abschied
Authors: Roth Klaus 
Published: December 2012

AbstractMehr als die Hälfte der Weltbevölkerung ist mit Helicobacter pylori infiziert. Meistens führt der ungeladene Gast in unserem Magen ein ruhiges Leben, aber er kann auch eine Menge Ärger machen. Um in einer Umgebung mit pH = 1 zu überleben, hat er eine glänzende Strategie entwickelt, um mit der übermächtigen Salzsäure zurechtzukommen. Seine Hauptwaffen sind die Säure‐Base‐Theorie und eine potente Urease. Dieses Enzym hydrolysiert Harnstoff zu Ammoniak und Kohlendioxid, die H. pylori helfen, um sich herum den pH auf verträgliche Werte zu halten. Um H. pylori loszuwerden, nutzen auch wir die Säure‐Basen‐Therorie plus Antibiotika und pfiffige Methoden, um den Therapieerfolg zu überprüfen. Auch wenn wir die Schlacht gewonnen haben, müssen wir trotzdem zugeben, dass H. pylori ein bemerkenswerter Chemiker ist und unseren Respekt verdient hat.
Co‐composting of Municipal Solid Waste with Sawdust: Improving Compost Quality
Authors: Yousefi Javad , Younesi Habibollah , Ghasempoury Seyed Mahmoud 
Published: December 2012

AbstractThe aim of present study was to improve compost quality as well as to achieve an optimum C/N ratio in compost, reduction in heavy metal content and increased water‐holding capacity of composting piles in arid areas. Four windrow compost piles were prepared by mixing sawdust at various dosages with municipal solid waste (MSW). The sawdust was mixed with MSW at 0% (MSW0), 16% (MSW16), 32% (MSW32), and 70% (MSW70) on dry weight basis. The compost piles were monitored daily by recording the temperature, while, weekly measurement was done on C/N ratio, moisture, pH, and electrical conductivity (EC). The addition of 16% sawdust increased the initial C/N to the optimum level and decreased N loss during the composting process. The MSW16 and MSW32 exhibited better temperature dynamics and their composting period seemed to be shorter than that of MSW0 and MSW70. Moreover, addition of sawdust caused lowering of moisture loss from the composting piles. Sawdust admixtures also produced lowering of pH and EC values and led to lower heavy metal content in final products. The quality of the final compost makes it possible to propose the use of this experimental procedure for building up a novel mass reduction of the initial composted waste mixtures.
Identification and Apportionment of Sources of Ozone‐forming Potential for Proper Reduction Strategies
Authors: Demir Selami , Saral Arslan 
Published: December 2012

AbstractIn this study, results of source identification and apportionment for ambient volatile organic compounds (VOCs) from a previous work were used to estimate ozone‐forming potentials (OFPs) of effective sources for developing proper strategies for reduction of tropospheric ozone pollution. The source identification and apportionment of ambient VOC pollution within Yildiz Technical University's Davutpasa Campus (Istanbul, Turkey) was done by positive matrix factorization (PMF). The results suggested five effective source groups with the emissions related with paint use and solvent use having the highest contributions (36.8 and 28.2%). The results from PMF were used along with maximum incremental reactivities to estimate potentials of individual sources for ozone formation. It was found that biogenic emissions (3.78) and traffic related emissions (gasoline and diesel vehicle exhaust) (3.83 and 3.15, respectively) have the highest potential for ozone formation in terms of grams O3/g VOC emitted. The results were used to suggest proper source‐based reduction strategies for OFP.
Adsorption of Thallium(I) Ions Using Eucalyptus Leaves Powder
Authors: Dashti Khavidaki Hossein , Aghaie Hossein 
Published: December 2012

AbstractUsing batch method, the adsorption of thallium(I) ions from aqueous solutions on eucalyptus leaves powder, as a low cost adsorbent, was studied. The effect of various modification of considered adsorbent on the adsorption percentage of Tl(I) is an important feature of this study. The results showed that the unmodified and acidic modified adsorbent are the poor adsorbents for the Tl(I) ions while basic modified adsorbent is a suitable adsorbent. Also, the effect of some experimental conditions such as solution initial pH, agitation speed, contact time, sorbent dosage, temperature, particle size, and thallium initial concentration was studied. The results showed that the adsorption percentage depends on the conditions and the process is strongly pH‐dependent. The satisfactory adsorption percentage of Tl(I) ions, 81.5%, obtained at 25 ± 1°C. The equilibrium data agreed fairly better with Langmuir isotherm than Freundlich and Temkin models. The value of qm that was obtained by extrapolation method is 80.65 mg g−1. Separation factor values, RL, showed that eucalyptus leaves powder is favorable for the sorption of Tl(I). The negative values of ΔH0 and ΔS0 showed that the Tl(I) sorption is an exothermic process and along with decrease of randomness at the solid–solution interface during sorption, respectively.
Morphology‐controlled CaMoO4 nanorods via a facile microwave‐assisted EDTA chelating agent process
Authors: Wang Lina , Sun Yan , Li Chunsheng , Wang Yaozu , Ma Xuegang , Wang Yandi , Li Shuoshuo , Zhang Zhijia , Ma Peijuan , Cui Guanghua 
Published: December 2012

AbstractThis work reports on the shape‐controlled synthesis of CaMoO4 nanorods via a high‐efficient microwave irradiation‐assisted chelating agent method. The phase and microstructure of these materials were systematically characterized by X‐ray diffraction and field‐emission scanning electron microscopy. It is noteworthy that EDTA plays pivotal roles as the complexing and capping agent in the oriented growth of uniform CaMoO4 nanorods. The synthetic process gives the guidance to understand the morphological evolution of CaMoO4 microstructures in microwave system, and provides a facile and designed strategy to fabricate functional one dimensional metallic molybdates.
Crystal growth and spectral properties of Nd:Ca5(BO3)3F
Authors: Xia Mingjun , Li R. K. 
Published: December 2012

AbstractA neodymium doped Ca5(BO3)3F single crystal with size up to 51×48×8 mm3 has been grown by the top seeded solution growth (TSSG) technique with a Li2O‐B2O3‐LiF flux. The spectra of absorption and fluorescence were measured at room temperature. According to Judd‐Ofelt (J‐O) theory, the spectroscopic parameters were calculated and the J‐O parameters Ω2, Ω4, Ω6 were obtained as follows: Ω2 = 1.41×10−20cm2, Ω4 = 3.18×10−20cm2, Ω6 = 2.11×10−20cm2. The room temperature fluorescence lifetime of NCBF was measured to be 51.8 μs. According to the J‐O paramenters, the emission probabilities of transitions, branching ratios, the radiative lifetime and the quantum efficiency from the Nd3+ 4F3/2 metastable state to lower lying J manifolds were also obtained. In comparasion with other Nd‐doped borate crystals, the calculated and experimental parameters show that NCBF is a promising SFD crystal.
Boron‐doped Homoepitaxial Diamond CVD from Microwave Plasma‐Activated Ethanol/Trimethyl Borate/Hydrogen Mixtures
Authors: Belousov Maxim E. , Mankelevich Yuri A. , Minakov Pavel V. , Rakhimov Alexander T. , Suetin Nikolay V. , Khmelnitskiy Roman A. , Tal Alexei A. , Khomich Alexander V. 
Published: December 2012

AbstractBoron‐doped homoepitaxial diamond films are deposited from ethanol/trimethyl borate/hydrogen mixtures activated by microwave (MW) discharge plasma. The high smoothness, uniform distribution of boron atoms located predominantly in substitution positions, and low concentration of the nitrogen‐compensating impurity is achieved. C2H5OH dissociation pathways in MW plasma‐activated (PA)CVD reactor conditions, and the distribution of CxHyOz concentrations in the hot core of C2H5OH/H2 plasma are calculated. It is shown that the methyl radical is as responsible for diamond growth in C2H5OH/H2 mixtures as for a conventional CH4/H2 mixture.