bluuebunny/crossref_metadata_2025_split huggingface dataset:
Directional dependence of the fatigue crack growth rate on Ti‐6Al‐4V due to a microstructural related transition of the crack closure mode
Authors: Kriegsmann A. , Müller C. 
Published: October 2013

AbstractAn der (α+β)‐Titanlegierung Ti‐6Al‐4V wurde durch gezielte Wärmebehandlung in einem Temperaturgradienten ein scharfer Gefügeübergang von globularem zu lamellarem Gefüge eingestellt. Globulare Gefüge zeigen bereits bei geringen Belastungen rein plastizitätsinduzierte Rissschließung, während bei lamellaren Gefügen bis zu hohen ΔK Werten rauigkeitsinduzierte Rissschließung beobachtet wird. Der gezielt eingestellte Gefügeübergang ermöglicht es somit, die Auswirkung eines Wechsels im Rissschließmodus (rauigkeitsinduziert, plastizitätsinduziert) auf die Rissausbreitung bei einer konstanten Schwingbreite der Spannungsintensität ΔK zu untersuchen. Beim Wechsel der Rissschließung von plastizitätsinduzierter zu rauigkeitsinduzierter Rissschließung stellt sich die Rissöffnungsbelastung für das jeweils an der Rissspitze vorliegende Gefüge ein. Beim Wechsel von rauigkeitsinduzierter zu plastizitätsinduzierter Rissschließung hingegen treten signifikante Rissschließeffekte im Risspfad auf, die zu höheren Rissöffnungsbelastungen und damit zu einer Verringerung der Rissausbreitungsgeschwindigkeit beitragen. Hierdurch entsteht für eine konstante Belastung ΔK eine Richtungsabhängigkeit der Rissausbreitungsgeschwindigkeit.
Cavitation tests to materials and coatings – comparison of different evaluation processes and identification of the cavitation erosion of EN‐GJS‐600‐3, G‐CuAl8Mn8 and GX4CrNi13‐4 + QT
Authors: Gäkle M. , Kley M. , Ritzel L. 
Published: October 2013

AbstractWerkstoffschäden an kavitationsbelasteten Strömungsmaschinen verursachen Kosten durch Reparatur und Stillstandszeit der Maschinen. Ziel muss es daher sein, die Kavitation durch Strömungsoptimierung zu verringern und durch eine geeignete Werkstoffauswahl in einen zeitlich unkritischen Bereich zu verschieben. Daher ist es erforderlich die Kavitationsbeständigkeit von Werkstoffen und Beschichtungen, welche zur Steigerung der Lebensdauer eingesetzt werden können, zu untersuchen. Im Hinblick auf eine umfassende Versuchsreihe wurde die Eignung verschiedener Auswerteverfahren wie Tastschnittmessung, Weißlichtprofilometrie, Wägung und optischer Vergleich untersucht um für den jeweiligen Anwendungsfall eine geeignete Auswertemethode auswählen zu können. Die Ergebnisse zeigen, dass sich zur Auswertung von Werkstoffversuchen die Wägung mit einer hochauflösenden Waage am besten eignet, wobei die Weißlichtprofilometrie dieser bei der genauen Auswertung von Beschichtungsversuchen deutlich überlegen ist. Der optische Vergleich eignet sich in beiden Fällen um schnelle Vergleiche anzustellen. Beispielhafte Untersuchungen zeigen die Kavitationsresistenz von G‐CuAl8Mn8 gegenüber den untersuchten Stählen auf.
Investigation on a new process chain of deposition or friction welding and subsequent hot forging
Authors: Frischkorn C. , Huskic A. , Hermsdorf J. , Barroi A. , Kaierle S. , Behrens B.‐A. , Overmeyer L. 
Published: October 2013

AbstractAccording to the state of the art most current forging parts and technical components are made of mono‐materials. Nevertheless, parts consisting of only one material increasingly reach their specific material and constructive limits in the established production processes. Through use of previously joined raw parts consisting of different materials, it is possible to produce application‐optimized hybrid parts. This paper describes the production chain of hybrid parts produced by combining two different joining processes with subsequent hot compression tests. The joining of various materials is realized by a deposition welding with a laser‐stabilized gas‐metal‐arc deposition welding (LGD) process and a conventional friction welding process. Subsequently, the hybrid samples are compressed under varying forming parameters such as temperature and deformation degrees. In order to characterize the joining zone, metallurgical investigations are carried out.
Investigation of jarosite process tailing waste by means of raman and infrared spectroscopy
Authors: Kerolli‐Mustafa M. , Bačić I. , Ćurković L. 
Published: October 2013

AbstractThe aim of this work was to identify and characterize three samples of jarosite process tailing waste in Mitrovica, Kosovo, using Raman and Fourier transform infrared (FTIR) spectroscopy. The identification is made based on the assignment of bands in the Raman and FTIR spectra. Both Raman and FTIR spectra show the fundamental stretching and bending vibration mode of SO42–, OH– and NH4+ groups. The results obtained by the means of Raman and infrared spectroscopy are compared with cited reference data in order to sum the analysis of vibrational spectra.
Fragmentations of [M–H]– anions of peptides containing Ser sulfate. A joint experimental and theoretical study
Authors: Nha Tran T. T. , Wang Tianfang , Hack Sandra , Bowie John H. 
Published: October 2013

RATIONALETo determine the negative‐ion cleavages from [M–H]– ions of Ser sulfate‐containing peptides using experiment and theory in concert.METHODSFragmentations were explored using a Waters QTOF2 mass spectrometer in negative‐ion electrospray mode, together with calculations at the CAM‐B3LYP/6‐311++g(d,p) level of theory. Peptides used in this study were:
urn:x-wiley:09514198:media:rcm6686:rcm6686-math-0001RESULTSPreviously, it has been shown that a peptide containing a Tyr sulfate group shows [(M–H)––SO3] as the base peak. Only a small peak was observed corresponding to HOSO3– (formed following rearrangement of the sulfate). A Ser sulfate‐containing peptide, in contrast, shows pronounced peaks due to cleavage product anions [(M–H)––SO3] and HOSO3–. Theoretical calculations at the CAM‐B3LYP/6‐311++g(d,p) level of theory suggest that rearrangement of a Ser sulfate to give C‐terminal CO2SO3H is energetically unfavourable in comparison with fragmentation of the intact Ser sulfate to yield [(M–H)––SO3] and HOSO3–. [(M–H)––H2SO4] anions are not observed in the spectra of peptides containing Ser sulfate, presumably because HOSO3– is a relatively weak gas‐phase base (ΔGacid = 1265 kJ mol–1).CONCLUSIONSExperimental and theoretical data suggest that [(M–H)––SO3] and HOSO3– product anions (from a peptide with a C‐terminal Ser sulfate) are formed from the serine sulfate anion accompanied by specific proton transfer. CID MS/MS/MS data for an [(M–H)––SO3] ion of an underivatised sulfate‐containing peptide will normally allow the determination of the amino acid sequence of that peptide. The one case we have studied where that is not the case is GLS(SO3H)GDA(OH), where the peptide contains Ser sulfate and Asp, where the diagnostic Asp cleavages are competitive with the Ser sulfate cleavages. Copyright © 2013 John Wiley & Sons, Ltd.
The quantitative surface analysis of an antioxidant additive in a lubricant oil matrix by desorption electrospray ionization mass spectrometry
Authors: Da Costa Caitlyn , Reynolds James C. , Whitmarsh Samuel , Lynch Tom , Creaser Colin S. 
Published: October 2013

RATIONALEChemical additives are incorporated into commercial lubricant oils to modify the physical and chemical properties of the lubricant. The quantitative analysis of additives in oil‐based lubricants deposited on a surface without extraction of the sample from the surface presents a challenge. The potential of desorption electrospray ionization mass spectrometry (DESI‐MS) for the quantitative surface analysis of an oil additive in a complex oil lubricant matrix without sample extraction has been evaluated.METHODSThe quantitative surface analysis of the antioxidant additive octyl (4‐hydroxy‐3,5‐di‐tert‐butylphenyl)propionate in an oil lubricant matrix was carried out by DESI‐MS in the presence of 2‐(pentyloxy)ethyl 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionate as an internal standard. A quadrupole/time‐of‐flight mass spectrometer fitted with an in‐house modified ion source enabling non‐proximal DESI‐MS was used for the analyses.RESULTSAn eight‐point calibration curve ranging from 1 to 80 µg/spot of octyl (4‐hydroxy‐3,5‐di‐tert‐butylphenyl)propionate in an oil lubricant matrix and in the presence of the internal standard was used to determine the quantitative response of the DESI‐MS method. The sensitivity and repeatability of the technique were assessed by conducting replicate analyses at each concentration. The limit of detection was determined to be 11 ng/mm2 additive on spot with relative standard deviations in the range 3–14%.CONCLUSIONSThe application of DESI‐MS to the direct, quantitative surface analysis of a commercial lubricant additive in a native oil lubricant matrix is demonstrated. © 2013 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons, Ltd.
An integrated exact mass spectrometric strategy for comprehensive and rapid characterization of phenolic compounds in licorice
Authors: Xu Tongtong , Yang Min , Li Yifeng , Chen Xin , Wang Qiurong , Deng Wangping , Pang Xiayan , Yu Kate , Jiang Baohong , Guan Shuhong , Guo De‐an 
Published: October 2013

RATIONALELicorice (Gancao) is derived from the dried roots and rhizomes of Glycyrrhiza species (Leguminosae) and appears as a component herb in about 60% of traditional Chinese medicine (TCM) prescriptions. Modern pharmacological studies have shown that flavonoids are one class of the major components responsible for the bioactivities of licorice. Ultra‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry (UPLC/QTOF MS) has proven to be a powerful tool for rapid profiling and identification of natural products in complex herbal medicines.METHODSA UPLC/QTOF MS method was established for the first time for profiling and structural characterization of the phenolic compounds (most of them flavonoids) in licorice. The combined use of data‐independent acquisition (MSE) and data‐dependent acquisition (DDA) was illustrated.RESULTSFifteen flavonoid reference compounds were used to explore the fragmentation pathways. Compound identification was based upon the exact mass, general fragmentation behaviors, retention times, UV absorption, and the related botanical biogenesis. As a result, a total of 51 compounds were characterized, three of which were reported for the first time.CONCLUSIONSThe LC/MS analysis for each injection took less than 9 min. The developed method is fast, accurate and reliable due to its high resolution and high efficiency characteristics as a result of combining both UPLC separation and QTOF exact mass measurement. Copyright © 2013 John Wiley & Sons, Ltd.
Electrostatic‐spray ionization mass spectrometry sniffing for perfume fingerprinting
Authors: Tobolkina Elena , Qiao Liang , Xu Guobin , Girault Hubert H. 
Published: October 2013

RATIONALEThe perfume market is growing significantly, and it is easy to find imitative fragrances of probably all types of perfume. Such imitative fragrances are usually of lower quality than the authentic ones, creating a possible threat for perfume companies. Therefore, it is important to develop efficient chemical analysis techniques to screen rapidly perfume samples.METHODSElectrostatic‐spray ionization (ESTASI) was used to analyze directly samples sprayed or deposited on different types of paper. A linear ion trap mass spectrometer was used to detect the ions produced by ESTASI with a modified extended transfer capillary for 'sniffing' ions from the paper.RESULTSSeveral commercial perfumes and a model perfume were analyzed by ESTASI‐sniffing. The results obtained by paper ESTASI‐MS of commercial fragrances were compared with those obtained from ESI‐MS. In addition, a commercial fragrance was first nebulized on the hand and then soaked up by blotting paper, which was afterwards placed on an insulating plate for ESTASI‐MS analysis. Analysis of peptides and proteins was also performed to show that the paper ESTASI‐MS could be used for samples with very different molecular masses.CONCLUSIONSPaper ESTASI‐MS yields a rapid fingerprinting characterization of perfume fragrances, avoiding time‐consuming sample‐preparation steps, and thereby performing a rapid screening in a few seconds. Copyright © 2013 John Wiley & Sons, Ltd.
Can ion mobility mass spectrometry and density functional theory help elucidate protonation sites in 'small' molecules?
Authors: Lapthorn Cris , Dines Trevor J. , Chowdhry Babur Z. , Perkins George L. , Pullen Frank S. 
Published: October 2013

RATIONALEIon mobility spectrometry‐mass spectrometry (IMS‐MS) offers an opportunity to combine measurements and/or calculations of the collision cross‐sections and subsequent mass spectra with computational modelling in order to derive the three‐dimensional structure of ions. IMS‐MS has previously been reported to separate two components for the compound norfloxacin, explained by protonation on two different sites, enabling the separation of protonated isomers (protomers) using ion mobility with distinguishable tandem mass spectrometric (MS/MS) data. This study reveals further insights into the specific example of norfloxacin and wider implications for ion mobility mass spectrometry.METHODSUsing a quadrupole ion mobility time‐of‐flight mass spectrometer, the IMS and MS/MS spectra of norfloxacin were recorded and compared with theoretical calculations using molecular modelling (density functional theory), and subsequent collision cross‐section calculations using projection approximation.RESULTSA third significant component in the ion mobilogram of norfloxacin was observed under similar experimental conditions to those previously reported. The presence of the new component is convoluted by co‐elution with another previously observed component.CONCLUSIONSThis case demonstrates the potential of combined IMS‐MS/MS with molecular modelling information for increased understanding of 'small‐molecule' fragmentation pathways. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of Surfactants on Catalytic Activity of Diastase α‐Amylase
Authors: Antony Navya , Balachandran SreedharanNair , Mohanan Puzhavoorparambil V. 
Published: October 2013

AbstractThe enzyme amylase is one of the hydrolyzing enzymes used in detergent formulation in order to remove soil based on polysaccharides. The effectiveness of the enzyme depends on its compatibility with other ingredients of the formulation. Among the studied additives, comprising anionic surfactants sodium dodecyl hydrogen sulfate (SDS) and dioctyl sodium sulfosuccinate, the cationic surfactant cetyl trimethyl ammonium bromide (CTAB), nonionic surfactants polyoxyethylene sorbitan monooleate and polyoxyethylene octyl phenyl ether, carboxy methyl cellulose and sodium sulfate, only the anionic surfactant SDS and cationic surfactant CTAB showed catalytic enhancement of α‐amylase. The kinetic parameters, Km and kcat, showed an increase in catalytic activity in the micellar pseudophase. The decrease in optimum temperature from 55 to 30 °C and the shift in optimum pH from 5.5 to 7 on the addition of SDS and CTAB for the hydrolysis of starch are very favorable to enhance the washing characteristics.
Volumetric, Compressibility, and Surface Tension Studies on Micellization Behavior of SDS in Aqueous Medium: Effect of Sugars
Authors: Chauhan Suvarcha , Kumar Kuldeep , Singh Kailash , Jyoti Jiwan 
Published: October 2013

AbstractThe densities , velocities of sound , and surface tension , of anionic surfactant sodium dodecyl sulfate in presence of aqueous saccharides (fructose and maltose) with concentrations 0.01 and 0.10 mol kg−1 have been reported over a wide temperature range (293.15–313.15 K) at an interval of 5 K. The apparent molar volume , isentropic compressibility , and apparent molar adiabatic compression values have been calculated using densities and velocities of sound data. Both, and vary non‐linearly at lower concentration of surfactant and tend to achieve linearity at higher concentration of surfactant in presence of saccharides. From the surface tension data, parameters like surface excess , minimum area occupied by the surfactant molecule at the saturated air/solution interface and surface film pressure have been computed. The effect of additives on these parameters has been discussed in terms of different types of the interactions pertaining in the micellar system. An attempt has also been made to draw an inference regarding the effect of these additives on the critical micelle concentration of the surfactant.
In and out: an analysis of epibiotic vs periplasmic bacterial predators
Authors: Pasternak Z , Njagi M , Shani Y , Chanyi R , Rotem O , Lurie-Weinberger M N , Koval S , Pietrokovski S , Gophna U , Jurkevitch E 
Published: October 2013

Abstract
Bdellovibrio and like organisms (BALO) are obligate predators of Gram-negative bacteria, belonging to the α- and δ-proteobacteria. BALO prey using either a periplasmic or an epibiotic predatory strategy, but the genetic background underlying these phenotypes is not known. Here we compare the epibiotic Bdellovibrio exovorus and Micavibrio aeruginosavorus to the periplasmic B. bacteriovorus and Bacteriovorax marinus. Electron microscopy showed that M. aeruginosavorus, but not B. exovorus, can attach to prey cells in a non-polar manner through its longitudinal side. Both these predators were resistant to a surprisingly high number of antibiotic compounds, possibly via 26 and 19 antibiotic-resistance genes, respectively, most of them encoding efflux pumps. Comparative genomic analysis of all the BALOs revealed that epibiotic predators have a much smaller genome (ca. 2.5 Mbp) than the periplasmic predators (ca. 3.5 Mbp). Additionally, periplasmic predators have, on average, 888 more proteins, at least 60% more peptidases, and one more rRNA operon. Fifteen and 219 protein families were specific to the epibiotic and the periplasmic predators, respectively, the latter clearly forming the core of the periplasmic ‘predatome’, which is upregulated during the growth phase. Metabolic deficiencies of epibiotic genomes include the synthesis of inosine, riboflavin, vitamin B6 and the siderophore aerobactin. The phylogeny of the epibiotic predators suggests that they evolved by convergent evolution, with M. aeruginosavorus originating from a non-predatory ancestor while B. exovorus evolved from periplasmic predators by gene loss.
Dispersal network structure and infection mechanism shape diversity in a coevolutionary bacteria-phage system
Authors: Sieber Michael , Robb Matthew , Forde Samantha E , Gudelj Ivana 
Published: October 2013

Abstract
Resource availability, dispersal and infection genetics all have the potential to fundamentally alter the coevolutionary dynamics of bacteria–bacteriophage interactions. However, it remains unclear how these factors synergise to shape diversity within bacterial populations. We used a combination of laboratory experiments and mathematical modeling to test how the structure of a dispersal network affects host phenotypic diversity in a coevolving bacteria-phage system in communities of differential resource input. Unidirectional dispersal of bacteria and phage from high to low resources consistently increased host diversity compared with a no dispersal regime. Bidirectional dispersal, on the other hand, led to a marked decrease in host diversity. Our mathematical model predicted these opposing outcomes when we incorporated modified gene-for-gene infection genetics. To further test how host diversity depended on the genetic underpinnings of the bacteria-phage interaction, we expanded our mathematical model to include different infection mechanisms. We found that the direction of dispersal had very little impact on bacterial diversity when the bacteria-phage interaction was mediated by matching alleles, gene-for-gene or related infection mechanisms. Our experimental and theoretical results demonstrate that the effects of dispersal on diversity in coevolving host–parasite systems depend on an intricate interplay of the structure of the underlying dispersal network and the specifics of the host–parasite interaction.
First biological measurements of deep-sea corals from the Red Sea
Authors: Roder C. , Berumen M. L. , Bouwmeester J. , Papathanassiou E. , Al-Suwailem A. , Voolstra C. R. 
Published: October 2013

AbstractIt is usually assumed that metabolic constraints restrict deep-sea corals to cold-water habitats, with ‘deep-sea’ and ‘cold-water’ corals often used as synonymous. Here we report on the first measurements of biological characters of deep-sea corals from the central Red Sea, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red Sea but occurs in deep cold waters outside the Red Sea raising interesting questions about presumed environmental constraints for other deep-sea corals. Our findings suggest that the present understanding of deep-sea coral persistence and resilience needs to be revisited.
Vanishing of interband light absorption in a persistent spin helix state
Authors: Li Zhou , Marsiglio F. , Carbotte J. P. 
Published: October 2013

AbstractSpin-orbit coupling plays an important role in various properties of very different materials. Moreover efforts are underway to control the degree and quality of spin-orbit coupling in materials with a concomitant control of transport properties. We calculate the frequency dependent optical conductivity in systems with both Rashba and Dresselhaus spin-orbit coupling. We find that when the linear Dresselhaus spin-orbit coupling is tuned to be equal to the Rashba spin-orbit coupling, the interband optical conductivity disappears. This is taken to be the signature of the recovery of SU(2) symmetry. The presence of the cubic Dresselhaus spin-orbit coupling modifies the dispersion relation of the charge carriers and the velocity operator. Thus the conductivity is modified, but the interband contribution remains suppressed at most but not all photon energies for a cubic coupling of reasonable magnitude. Hence, such a measurement can serve as a diagnostic probe of engineered spin-orbit coupling.
Competitive environments sustain costly altruism with negligible assortment of interactions
Authors: Doncaster C. Patrick , Jackson Adam , Watson Richard A. 
Published: October 2013

AbstractCompetition hinders the evolution of altruism amongst kin when beneficiaries gain at the expense of competing relatives. Altruism is consequently deemed to require stronger kin selection, or trait-selected synergies, or elastic population regulation, to counter this effect. Here we contest the view that competition puts any such demands on altruism. In ecologically realistic scenarios, competition influences both altruism and defection. We show how environments that pit defectors against each other allow strong altruism to evolve even in populations with negligible kin structure and no synergies. Competition amongst defectors presents relative advantages to altruism in the simplest games between altruists and defectors and the most generic models of altruistic phenotypes or genotypes invading non-altruistic populations under inelastic density regulation. Given the widespread inevitability of competition, selection will often favour altruism because its alternatives provide lower fitness. Strong competition amongst defectors nevertheless undermines altruism, by facilitating invasion of unrelated beneficiaries as parasites.