bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Uelzen I Lock – Hypoplastic finite‐element analysis of cyclic loading
Authors: von Wolffersdorff Peter‐Andreas , Schwab Radu 
Published: January 2010

AbstractThe Uelzen I lock is a very suitable case to analyse the soil‐structure interaction during cyclic loading, because its plate‐rib structure is very flexible, the amplitude of the load cycles during lock operation is high and an extensive geotechnical monitoring system was installed in 1992.A 3D finite element simulation was used to predict the long‐term behaviour of the lock during cyclic loading. The main interest of the simulation was to choose an adequate constitutive law to simulate the quasi‐static cyclic behaviour of the soil. The adopted hypoplastic constitutive law with intergranular strain is briefly described in the paper. The computed results are compared with the measurements. The results of elastic‐perfect plastic Mohr‐Coulomb and hypoplastic simulations without intergranular strain are presented for comparison. Some interesting aspects are evidenced, such as the ‘stick‐slip’ reduction of the arching effect in the backfill due to cyclic loading.
Effective algorithm for parameter back calculation – Geotechnical applications
Authors: Meier Jörg , Rudolph Sebastian , Schanz Tom 
Published: January 2010

AbstractWhen working with numerical models, it is essential to determine model parameters which are as realistic as possible. Optimization techniques are used more and more frequently to solve this task. However, using these methods may lead to very high time costs – in particular, if rather complicated forward calculations are involved. In this paper, we present a class of methods wich allows estimating the solution of this kind of optimization problems, based on relatively few sampling points. We put very weak constraints on the sampling point distribution; hence, they may be taken from previous forward calculations as well as from alternative sources.Starting from an introduction into the theoretical approach, a strategy for speeding up inverse optimization problems is introduced which is illustrated by an example from geomechanics.
Buckling of slender piles in soft soils
Authors: Vogt Norbert , Vogt Stefan , Kellner Christian 
Published: January 2010

AbstractBuckling of piles is prevented by the surrounding soil. Therefore, in sufficiently stiff soils, there is no risk of pile buckling with conventional geometry (L/D ratio). National and international design codes require checks of the safety against buckling for slender piles in soils with undrained shear strengths of cu < 15 kPa or cu < 10 kPa, respectively. In practice, the codes imply that buckling failure does not occur at higher undrained shear strengths. However, using simple calculations, this assumption has been proven to be invalid for slender piles such as micropiles. For the reason, buckling tests on 4 m long micropiles were carried out in soft clay. Based on these results, a new concept with supporting documents for calculating buckling loads was derived, which covers all essential aspects observed in the tests. The proposed model accounts for material non‐linearity, as well as second order effects.
Absence of corneal endothelium injury in non‐human primates treated with and without ophthalmologic drugs and exposed to 2.8 GHz pulsed microwaves
Authors: Lu Shin‐Tsu , D'Andrea John , Chalfin Steven , Crane Carrie , Marchello Donald , Garay Robert , Hatcher Donald , Ziriax John 
Published: January 2010

AbstractMicrowave‐induced corneal endothelial damage was reported to have a low threshold (2.6 W/kg), and vasoactive ophthalmologic medications lowered the threshold by a factor of 10–0.26 W/kg. In an attempt to confirm these observations, four adult male Rhesus monkeys (Macaca mulatta) under propofol anesthesia were exposed to pulsed microwaves in the far field of a 2.8 GHz signal (1.43 ± 0.06 µs pulse width, 34 Hz pulse repetition frequency, 13.0 mW/cm2 spatial and temporal average, and 464 W/cm2 spatial and temporal peak (291 W/cm2 square wave equivalent) power densities). Corneal‐specific absorption rate was 5.07 W/kg (0.39 W/kg/mW/cm2). The exposure resulted in a 1.0–1.2 °C increase in eyelid temperature. In Experiment I, exposures were 4 h/day, 3 days/week for 3 weeks (nine exposures and 36 h total). In Experiment II, these subjects were pretreated with 0.5% Timolol maleate and 0.005% Xalatan® followed by 3 or 7 4‐h pulsed microwave exposures. Under ketamine–xylazine anesthesia, a non‐contact specular microscope was used to obtain corneal endothelium images, corneal endothelial cell density, and pachymetry at the center and four peripheral areas of the cornea. Ophthalmologic measurements were done before and 7, 30, 90, and 180 days after exposures. Pulsed microwave exposure did not cause alterations in corneal endothelial cell density and corneal thickness with or without ophthalmologic drugs. Therefore, previously reported changes in the cornea exposed to pulsed microwaves were not confirmed at exposure levels that are more than an order of magnitude higher. Bioelectromagnetics 31:324–333, 2010. Published 2010 Wiley‐Liss, Inc.
Power variations of wireless communication systems
Authors: Andersen J.B. , Mogensen P.E. , Pedersen G.F. 
Published: January 2010

AbstractThe use of wireless digital communication devices like GSM, WCDMA, HSPA, DECT, and WiFi changes the exposure of electromagnetic waves toward the user. Concentrating on the power variations on a slow and fast time scale, these new systems are discussed. Experimental results for both uplink and downlink are included for a sample of systems. The spectrum of the power fluctuations is seen as a convenient and compact way of describing very complex system behavior. The results are of interest for scientific studies of epidemiology and biological effects, and for general electromagnetic compatibility (EMC) aspects. Bioelectromagnetics 31:302–310, 2010. © 2010 Wiley‐Liss, Inc.
Richtungsanalyse von Fasern in Betonen auf Basis der Computer‐Tomographie
Authors: Schnell Jürgen , Schladitz Katja , Schuler Frank 
Published: January 2010

AbstractFür die Festbetoneigenschaften von Faserbetonen sind die Fasermenge, Faserorientierung und Faserverteilung ausschlaggebend. Dies macht eine Überwachung dieser Parameter notwendig, sei es zur Qualitätssicherung auf der Baustelle oder im Bereich der Forschung zur Weiterentwicklung solcher Betone. Gegenüber bisher angewendeten Methoden zur Untersuchung dieser Einflussgrößen eröffnet die Computer‐Tomographie die Möglichkeit, für Betone mit Fasern und Gelegen aller Art die Faserorientierung und Faserverteilung im gesamten Volumen eines Probekörpers zu betrachten und zu analysieren.Direction Analysis of Fibres in Concrete on Basis of Computed TomographyDecisive factors for the improvement of the hardened concrete characteristics of fibre reinforced concrete are the fibre‐volumeratio, fibre‐orientation and fibre‐distribution. The application of fibre reinforced concrete mixtures requires an appropriate control of these characteristics in the context of quality control at the building site as well as in research work done to improve this kind of concretes. Compared to the methods used up to now, the computed tomography offers the possibility to examine and analyze fibre‐orientation and fibre‐distribution in the entire volume of a specimen.
Textilbeton verstärkte Platten unter Brandbelastung
Authors: Ehlig Daniel , Jesse Frank , Curbach Manfred 
Published: January 2010

AbstractIm Rahmen experimenteller Untersuchungen wurden Stahlbetonplatten hergestellt, mit verschiedenen textilen Bewehrungen verstärkt, durch Belastung bis 125% Gebrauchslast vorgeschädigt und anschließend unter Gebrauchslast mit einer Brandbelastung nach der Einheitstemperaturkurve (ISO‐834, Cellulosic curve) beaufschlagt. Alle Platten hielten der Brandbelastung bei gleichzeitiger Biegebeanspruchung mehr als 60 Minuten stand und zeigten weder Betonabplatzungen noch andere optische Schädigungen auf. Die für dieses überraschend positive Ergebnis verantwortlichen Mechanismen werden diskutiert, sind aber noch nicht vollständig verstanden. Eine Schlüsselrolle spielt dabei vermutlich das gute Rissverhalten von Textilbeton und interne Lastumlagerungen zwischen Textil‐ und Stahlbewehrung.Textile Reinforced Concrete Strengthened Slabs under Fire LoadingWithin an experimental study steel reinforced concrete slabs were produced and strengthened with different types of textile reinforcements. They were than pre‐damaged with 125% service load and subsequently exposed to fire loading (ISO‐834, Cellulosic curve) under simultaneous service load. The tests lasted up to 60 minutes with no specimen failed. The slabs did not show any visual damage nor concrete spalling. We discuss the presumably reasons for that surprisingly positive test result, although mechanisms are not yet fully understood. The excellent crack control of TRC and load redistribution between textile and steel reinforcement as well as load redistribution in the slabs are assumedly key mechanisms that contribute to the excellent fire resistance.
Introducing proteomics in the undergraduate curriculum: A simple 2D gel electrophoresis exercise with serum proteins
Authors: Kim Thomas D. , Craig Paul A. 
Published: January 2010

AbstractTwo‐dimensional gel electrophoresis (2DGE) remains an important tool in the study of biological systems by proteomics. While the use of 2DGE is commonplace in research publications, there are few instructional laboratories that address the use of 2DGE for analyzing complex protein samples. One reason for this lack is the fact that the preparation of samples for 2DGE is a complex and difficult process that can commonly yield gels of poor quality and resolution. In this experiment, we use a serum‐based sample to mitigate many of the sample preparation issues that occur in cell‐based sample preparations and incorporate a protein precipitation method that was developed to address the problem of high‐abundance proteins and dynamic range in serum proteomics research. By focusing on 2DGE apart from many other facets of proteomic experimental design, students have the opportunity to gain fruitful experience in the use of this workhorse proteomics technique. This simplified focus also makes this exercise accessible to biochemistry instructors who are not active in proteomics; the requisite techniques may require some new equipment (i.e. an isoelectric focusing apparatus), but this exercise focuses on using familiar techniques (primarily electrophoresis) to cross the threshold of a new field, proteomics.
Paternity testing in a PBL environment
Authors: Casla Alberto Vicario , Zubiaga Isabel Smith 
Published: January 2010

AbstractProblem Based Learning (PBL) makes use of real‐life scenarios to stimulate students' prior knowledge and to provide a meaningful context that is also related to the student's future professional work. In this article, Paternity testing is presented using a PBL approach that involves a combination of classroom, laboratory, and out‐of‐class activities: in relation to a fictitious newborn found on the Campus, students design a PCR based protocol to determine their own genotype for two markers. Pooled class genotypes serve to calculate allelic frequencies and to assess Hardy–Weinberg equilibrium. Individual results are also evaluated for possible paternity. The goals of the activity and how each step in the process relates to learning outcomes are presented. Classroom discussions, group discussions, tutorial sessions, wiki sites, laboratory activities, and individual reports sum up the situations, in which the students' process of learning and learning outcomes can be evaluated.
Fetal development of the retrohepatic inferior vena cava and accessory hepatic veins: Re‐evaluation of the Alexander Barry's hypothesis
Authors: Jin Zhe Wu , Cho Baik Hwan , Murakami Gen , Fujimiya Mineko , Kimura Wataru , Yu Hee Chul 
Published: January 2010

AbstractThe retrohepatic inferior vena cava (IVC) is commonly considered to originate from the right vitelline or omphalomesenteric vein. In contrast, Alexander Barry hypothesized that one of the hepatic veins grows to merge with the subcardinal vein and develops into the retrohepatic IVC. We re‐examined fetal development of the retrohepatic IVC and other related veins using serial histological sections of 20 human fetuses between 6 and 16 weeks of gestation. At 6–7 weeks, when a basic configuration of the portal‐hepatic vein systems had just been established, one of hepatic veins (i.e., the posterocaudal vein in the present study) had grown caudally to reach the posterocaudal surface of the liver, and notably, extended into the primitive right adrenal gland (five of the eight early‐staged fetuses). Because the inferior right hepatic vein (IRHV) and retrohepatic IVC appeared at the same developmental stage, it is likely that any peripheral remnants of the posterocaudal vein would continue to function as primary drainage territory for the IRHV. The caudate vein developed rapidly in accordance with marked caudal and leftward extension of Spiegel's lobe at 12–16 weeks. Thin accessory hepatic veins developed later than the caudate vein and IRHV. The present results supported Barry's hypothesis. Clin. Anat. 23:297–303, 2010. © 2010 Wiley‐Liss, Inc.
Effects of Operating Parameters on the Cinnamaldehyde Content of Extracted Essential Oil Using Various Methods
Authors: Baseri H. , Haghighi‐Asl A. , Lotfollahi M. N. 
Published: January 2010

AbstractSupercritical fluid extraction (SFE) of essential oils from commercial cinnamon bark was compared with essential oils that were obtained by hydrodistillation. Effects of operating parameters (pressure, temperature and extraction time of SFE) on the extraction yield and the composition of the extracted volatile oil were studied. Moreover, in the hydrodistillation process, the effect of the pH of the solvent on the concentration of cinnamaldehyde in the extracted volatile oil was studied. The maximum yield of extract in the SFE process is about 7.8 % at 70 °C and 240 bar. The maximum concentration of cinnamaldehyde in the SFE process was obtained at 70 °C and 160 bar, and the maximum concentration of this component in hydrodistillation was achieved at pH = 4.1.
Chitosan/titanate Nanotube Hybrid Membrane with Low Methanol Crossover for Direct Methanol Fuel Cells
Authors: Geng J. , Jiang Z. , Wang J. , Shi Y. , Yang D. , Xiao L. 
Published: January 2010

AbstractTitanate nanotubes (TNTs) about 10 nm in diameter and 200–600 nm in length were hydrothermally synthesized, and then incorporated into a chitosan (CS) matrix to fabricate chitosan/titanate nanotube (CS/TNT) hybrid membranes for a direct methanol fuel cell (DMFC). These hybrid membranes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray powder diffraction (XRD), thermogravimetry (TG), and positron annihilation lifetime spectroscopy (PALS). Moreover, their performances, including mechanical strength, water and methanol uptake, methanol permeability, and proton conductivity were determined. SEM results demonstrated that TNTs dispersed homogeneously in the hybrid membranes. Mechanical strength and TG measurements demonstrated that the mechanical and thermal stability of CS/TNT hybrid membranes were much higher than those of pure chitosan membranes. PALS analysis revealed that the fractional free volume (FFV) of CS/TNT hybrid membranes increased with the incorporation of TNTs and, thus, resulting in the reduction of methanol crossover. In all as‐prepared membranes, the hybrid membrane containing 15 wt % TNTs exhibited the highest mechanical strength of 85.0 MPa, low methanol permeability of 0.497 · 10–6 cm2·s–1, and proton conductivity of 0.0151 S·cm–1, which had the potential for DMFC applications.
A Case Study in the Pre‐Calculation of Henry Coefficients
Authors: Franke R. , Hannebauer B. , Jung S. 
Published: January 2010

AbstractGas solubilities belong to the class of property data that form the basis for a large number of technological applications. For example, they represent the property data basis for absorption processes and are important in the design of gas‐liquid reactors. In this paper, we determine Henry coefficients as a measure of gas solubility by means of a series of computational approaches used in industrial practice, and we compare the results to experimentally determined values. Temperature‐varied values for hydrocarbon‐alcohol systems constitute the object of the study. Of the methods employed, PSRK, UNIFAC(Do) and COSMO‐RS display the highest predictive capability.
Synthesis, Structure, and Physico‐optical Properties of Manganate(II)‐Based Ionic Liquids
Authors: Pitula Slawomir , Mudring Anja‐Verena 
Published: February 2010

AbstractSeveral ionic liquids (ILs) based on complex manganate(II) anions with chloro, bromo, and bis(trifluoromethanesulfonyl)amido (Tf2N) ligands have been synthesized. As counterions, n‐alkyl‐methylimidazolium (Cnmim) cations of different chain length (alkyl=ethyl (C2), propyl (C3), butyl (C4), hexyl (C6)) were chosen. Except for the 1‐hexyl‐3‐methylimidazolium ILs, all of the prepared compounds could be obtained in a crystalline state at room temperature. However, each of the compounds displayed a strong tendency to form a supercooled liquid. Generally, solidification via a glass transition took place below −40 °C. Consequently, all of these compounds can be regarded as ionic liquids. Depending on the local coordination environment of Mn2+, green (tetrahedrally coordinated Mn2+) or red (octahedrally coordinated Mn2+) luminescence emission from the 4T(G) level is observed.1 The local coordination of the luminescent Mn2+ centre has been unequivocally established by UV/Vis as well as Raman and IR vibrational spectroscopies. Emission decay times measured at room temperature in the solid state (crystalline or powder) were generally a few ms, although, depending on the ligand, values of up to 25 ms were obtained. For the bromo compounds, the luminescence decay times proved to be almost independent of the physical state and the temperature. However, for the chloro‐ and bis(trifluoromethanesulfonyl)amido ILs, the emission decay times were found to be dependent on the temperature even in the solid state, indicating that the measured values are strongly influenced by nuclear motion and the vibration of the atoms. In the liquid state, the luminescence of tetrahedrally coordinated Mn2+ could only be observed when the tetrachloromanganate ILs were diluted with the respective halide ILs. However, for [C3mim][Mn(Tf2N)3], in which Mn2+ is in an octahedral coordination environment, a weak red emission from the pure compound was found even in the liquid state at elevated temperatures.
Understanding the Signatures of Secondary‐Structure Elements in Proteins with Raman Optical Activity Spectroscopy
Authors: Jacob Christoph R. , Luber Sandra , Reiher Markus 
Published: January 2010

AbstractA prerequisite for the understanding of functional molecules like proteins is the elucidation of their structure under reaction conditions. Chiral vibrational spectroscopy is one option for this purpose, but provides only indirect access to this structural information. By first‐principles calculations, we investigate how Raman optical activity (ROA) signals in proteins are generated and how signatures of specific secondary‐structure elements arise. As a first target we focus on helical motifs and consider polypeptides consisting of twenty alanine residues to represent α‐helical and 310‐helical secondary‐structure elements. Although ROA calculations on such large molecules have not been carried out before, our main goal is the stepwise reconstruction of the ROA signals. By analyzing the calculated ROA spectra in terms of rigorously defined localized vibrations, we investigate in detail how total band intensities and band shapes emerge. We find that the total band intensities can be understood in terms of the reconstructed localized vibrations on individual amino acid residues. Two different basic mechanisms determining the total band intensities can be established, and it is explained how structural changes affect the total band intensities. The band shapes can be rationalized in terms of the coupling between the localized vibrations on different residues, and we show how different band shapes arise as a consequence of different coupling patterns. As a result, it is demonstrated for the chiral variant of Raman spectroscopy how collective vibrations in proteins can be understood in terms of well‐defined localized vibrations. Based on our calculations, we extract characteristic ROA signatures of α helices and of 310‐helices, which our analysis directly relates to differences in secondary structure.
Nocardiopsins: New FKBP12‐Binding Macrolide Polyketides from an Australian Marine‐Derived Actinomycete, Nocardiopsis sp.
Authors: Raju Ritesh , Piggott Andrew M. , Conte Melissa , Tnimov Zakir , Alexandrov Kirill , Capon Robert J. 
Published: January 2010

AbstractA marine‐derived actinomycete, Nocardiopsis sp. (CMB‐M0232), obtained from a sediment sample collected at a depth of 55 m off the coast of Brisbane, Australia, yielded two new macrolide polyketides. Structures for nocardiopsins A and B were assigned by detailed spectroscopic analysis, degradation and chemical derivatization. A Marfey’s analysis revealed an unexpected acid‐mediated partial racemization of the L‐pipecolic acid incorporated within the nocardiopsins. The scope of this racemization was assessed against a selection of natural and synthetic N‐acyl pipecolic acids. While the nocardiopsins are not antibacterial, antifungal or cytotoxic, they do exhibit low‐micromolar binding to the immunophilin FKBP12, consistent with their structural and biosynthetic relationship to the immunosuppressive agents FK506 and rapamycin. The nocardiopsins represent a new point of entry into what has been a valuable, exclusive and reclusive region of bioactive chemical space—that surrounding the FK506/rapamycin pharmacophore.
ChemInform Abstract: Spin Glass Behavior of Isolated, Geometrically Frustrated Tetrahedra of Iron Atoms in the Intermetallic La21Fe8Sn7C12.
Authors: Benbow Evan M. , Dalal Naresh S. , Latturner Susan E. 
Published: January 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Suboxides with Complex Anions: The Suboxoindate Cs9InO4.
Authors: Hoch Constantin , Bender Johannes , Simon Arndt 
Published: January 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Tetrahedral [Tt4]4‐ Zintl Anions Through Solution Chemistry: Syntheses and Crystal Structures of the Ammoniates Rb4Sn4·2NH3, Cs4Sn4·2NH3, and Rb4Pb4·2NH3.
Authors: Wiesler Katharina , Brandl Karoline , Fleischmann Andrea , Korber Nikolaus 
Published: January 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.