bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of the reactivity ratios, sequence distribution and stereoregularity of butyl acrylate‐methyl methacrylate copolymers by means of proton and carbon‐13 NMR
Authors: Aerdts A. M. , German A. L. , van der Velden G. P. M.
Published: April 2014

The 400 MHz proton NMR spectra of butyl acrylate (BA)—methyl methacrylate (MMA) copolymers prepared by free radical polymerization in solution at 323 K were used for the determination of the reactivity ratios. The reactivity ratios rM and rB calculated by the error‐in‐variables method are 2.279 and 0.395, respectively. The methoxy region of the MMA proton signal resonance was found to be sensitive for MMA‐centred sequences and a new assignment is proposed. The coisotacticity parameter σBM was calculated using a non‐linear least‐squares procedure with relative error estimation based on the new assignment and was found to be 039. The carbon‐13 NMR spectra of the BA‐MMA copolymers, in particular the carbonyl signal resonances, are sensitive for MMA‐and BA‐centred configurational sequences. The same assignment is used as for the ethyl acrylate—methyl methacrylate copolymer.
A robust and efficient substepping scheme for the explicit numerical integration of a rate‐dependent crystal plasticity model
Authors: Zhang K. , Hopperstad O. S. , Holmedal B. , Dumoulin S.
Published: April 2014

This paper describes the development of efficient and robust numerical integration schemes for rate‐dependent crystal plasticity models. A forward Euler integration algorithm is first formulated. An integration algorithm based on the modified Euler method with an adaptive substepping scheme is then proposed, where the substepping is mainly controlled by the local error of the stress predictions within the time step. Both integration algorithms are implemented in a stand‐alone code with the Taylor aggregate assumption and in an explicit finite element code. The robustness, accuracy and efficiency of the substepping scheme are extensively evaluated for large time steps, extremely low strain‐rate sensitivity, high deformation rates and strain‐path changes using the stand‐alone code. The results show that the substepping scheme is robust and in some cases one order of magnitude faster than the forward Euler algorithm. The use of mass scaling to reduce computation time in crystal plasticity finite element simulations for quasi‐static problems is also discussed. Finally, simulation of Taylor bar impact test is carried out to show the applicability and robustness of the proposed integration algorithm for the modelling of dynamic problems with contact. Copyright © 2014 John Wiley & Sons, Ltd.
Adolescent Risperidone treatment alters protein expression associated with protein trafficking and cellular metabolism in the adult rat prefrontal cortex
Authors: Farrelly Lorna A. , Dicker Patrick , Wynne Kieran , English Jane , Cagney Gerard , Föcking Melanie , Cotter David R.
Published: April 2014

The prefrontal cortex (PFC) is associated with mental health illnesses including schizophrenia, depression, bipolar disorder, and autism spectrum disorders. It richly expresses neuroreceptors which are the target for antipsychotics. However, as the precise mechanism of action of antipsychotic medications is not known, proteomic studies of the effects of antipsychotic drugs on the brain are warranted. In the current study, we aimed to characterize protein expression in the adult rodent PFC (n = 5 per group) following low‐dose treatment with Risperidone or saline in adolescence (postnatal days 34–47). The PFC was examined by triplicate 1 h runs of label‐free LC‐MS/MS. The raw mass spectral data were analyzed with the MaxQuantTM software. Statistical analysis was carried out using SAS® Version 9.1. Pathway and functional analysis was performed with IngenuityPathway Analysis and in the Database for Annotation, Visualization and Integrated Discovery (DAVID), respectively, the most implicated pathways were found to be related to mitochondrial function, protein trafficking, and the cytoskeleton. This report adds to the current repertoire of data available concerning the effects of antipsychotic drugs on the brain and sheds light on their biological mechanisms. The MS data have been deposited with the ProteomeXchange Consortium with dataset identifier PXD000480.
Self‐assembling amphiphilic peptides
Authors: Dehsorkhi Ashkan , Castelletto Valeria , Hamley Ian W.
Published: April 2014

The self‐assembly of several classes of amphiphilic peptides is reviewed, and selected applications are discussed. We discuss recent work on the self‐assembly of lipopeptides, surfactant‐like peptides and amyloid peptides derived from the amyloid‐βpeptide. The influence of environmental variables such as pH and temperature on aggregate nanostructure is discussed. Enzyme‐induced remodelling due to peptide cleavage and nanostructure control through photocleavage or photo‐cross‐linking are also considered. Lastly, selected applications of amphiphilic peptides in biomedicine and materials science are outlined. © 2014 The Authors.Journal of Peptide Sciencepublished by European Peptide Society and John Wiley & Sons, Ltd.
Controllability of impulsive mixed type Volterra–Fredholm stochastic systems with nonlocal conditions
Authors: Zhang Shuorui , Sun Jitao
Published: April 2014

This paper investigates complete controllability of impulsive mixed type Volterra–Fredholm stochastic systems with nonlocal conditions. Sufficient conditions are established for complete controllability of a class of impulsive stochastic integrodifferential systems with nonlocal conditions. The results are obtained by a fixed point approach on condition that the corresponding linear system is completely controllable. Finally, an example is given to illustrate our results. Copyright © 2014 John Wiley & Sons, Ltd.
Direct adaptive control for a class of discrete‐time unknown nonaffine nonlinear systems using neural networks
Authors: Yang Xiong , Liu Derong , Wei Qinglai , Wang Ding
Published: April 2014

In this paper, a direct adaptive state‐feedback control approach is developed for a class of nonlinear systems in discrete‐time (DT) domain. We study MIMO unknown nonaffine nonlinear DT systems and employ a two‐layer NN to design the controller. By using the presented method, the NN approximation is able to cancel the nonlinearity of the unknown DT plant. Meanwhile, pretraining is not required, and the weights of NNs used in adaptive control are directly updated online. Moreover, unlike standard NN adaptive controllers yielding uniform ultimate boundedness results, the tracking error is guaranteed to be uniformly asymptotically stable by utilizing Lyapunov's direct method. Two illustrative examples are provided to demonstrate the effectiveness and the applicability of the theoretical results. Copyright © 2014 John Wiley & Sons, Ltd.
Sonication‐Induced Formation of Size‐Controlled Self‐Assemblies of Amphiphilic Janus‐Type Polymers as Optical Tumor‐Imaging Agents
Authors: Miki Koji , Hashimoto Hiroki , Inoue Tatsuhiro , Matsuoka Hideki , Harada Hiroshi , Hiraoka Masahiro , Ohe Kouichi
Published: April 2014

In this study, amphiphilic Janus‐type polymers were synthesized via ring‐opening metathesis polymerization (ROMP), multiple vicinal diol formation, and grafting of poly(ethylene glycol) monomethyl ether (mPEG). These amphiphilic polymers formed self‐assemblies, which were a mixture of micelles and multimicellar aggregates, in water. By choosing suitable Janus‐type polymers and irradiating an aqueous solution of polymers using a sonicator, either small micelles or large multimicellar aggregates were obtained selectively. Hydrophobic substituents controlled the aggregation–disaggregation behavior, leading to the formation of metastable self‐assemblies by sonication. The formation of self‐assemblies with a uniform size was affected by ultrasonic frequency, rather than power. In vivo optical tumor imaging revealed that the large‐size multimicellar aggregates persisting for a long time in blood circulation slowly accumulated in tumor tissues. In contrast, the tumor site was rapidly, clearly visualized using the small‐size micelles.
Eutectic Combinations as a Pathway to the Formation of Substrate‐Based Au‐Ge Heterodimers and Hollowed Au Nanocrescents with Tunable Optical Properties
Authors: Sundar Aarthi , Farzinpour Pouyan , Gilroy Kyle D. , Tan Teng , Hughes Robert A. , Neretina Svetlana
Published: April 2014

Pairs of immiscible elements with deep eutectics are used to synthesize periodic arrays of heterodimers and hollowed metal nanocrescents. In the devised route, substrate‐immobilized Au or Ag nanostructures act as heterogeneous nucleation sites for Ge adatoms. At elevated temperatures the adatoms collect in sufficient quantities to transform each site into a AuGe liquid alloy which, upon cooling, phase separates into elemental components sharing a common interface. The so‐formed Au‐Ge and Ag‐Ge heterodimers exhibit a complex morphology characterized by a noble metal nanocrescent which partially encapsulates one end of the Ge domain. Through the use of a selective etch the Ge component is removed, leaving behind a periodic array of hollow noble metal nanocrescents on the surface of the substrate. Optical characterization of both the heterodimers and nanocrescents indicates that the presence of Ge gives rise to a relative blue‐shift in the localized surface plasmon peak, a result that is in stark contrast to the red‐shifts typically observed when plasmonic nanostructures are in contact with a dielectric medium. Simulations are used to both rationalize the observed shift and show the potential for deriving unexpected behaviors when semishell‐like noble metal structures are in contact with high permittivity dielectric mediums.
Modell für den nachgiebigen Randverbund von Mehrscheiben‐Isoliergläsern
Authors: Ensslen Frank , Becker Heinz‐Rainer , Wittwer Wolfgang
Published: April 2014

Der Randverbund von Isoliergläsern unterliegt hohen Anforderungen. Die Primärdichtstufe ist für die Dauerhaftigkeit des Systems hinsichtlich einer geringen Feuchtigkeitsaufnahme bzw. Gasverlustrate verantwortlich. Die Sekundärdichtstufe dient der Stabilität und dem Zusammenhalt der Gläser unter statischen sowie klimatisch induzierten Lasten. Die Funktionsweise des zweistufigen Randverbunds beruht auf dem komplexen Zusammenspiel zweier Polymerwerkstoffe und einem Abstandhalter. Der Beitrag beschreibt einen empirischen Ansatz: Auf Basis genauer Vermessung der Verformung verschiedener Probekörper unter definiert einwirkenden Lasten erfolgt die Bereitstellung einer Datenbasis, welche im Weiteren zur Ermittlung mechanischer Kenngrößen eines Federmodelles für den Randverbund herangezogen wird. Dieses Modell wird in FE‐Studien verwendet und mit dem üblichen, auf der Plattentheorie basierenden Rechenmodell verglichen.

Model for the Elastic Edge Seal of Insulating Glass Units. The edge seal of Insulating Glass Units (IGU) is exposed to demanding conditions. The primary seal contributes mainly to the durability of the system with respect to its low moisture penetration and very low gas loss rates. The secondary seal provides mechanical fixing and stability of the glass assembly under static and climatic loads. The functionality of the dual seal is the result of a complex interaction of two polymeric materials and the spacer bar. This study describes an empirical approach: Based on the precise measurement of deformation under several well‐defined load scenarios of specimen modelling the edge seal, the data base gained is used to calibrate the springs of a suited mechanical model of IGU’s edge seal. The model is used in FE studies and results compared with conventional plate theory based modelling.

Schlagwörter: Isolierglasrandverbund, Versiegelung, Randlast, Federkennlinie, Polymermechanik, Polymerversuche, viskoelastisches Verhalten, Plattenmodell
Energetische Sanierung Hypo Hochhaus – Gebogene 3‐fach Isolierverglasung der neuen Doppelfassade
Authors: Siebert Barbara , Herrmann Tobias
Published: April 2014

Das 1981 fertiggestellte Hypo Hochhaus, mittlerweile ein Wahrzeichen der Stadt München, wird derzeit umfangreich saniert und zu einem “green building“ umgestaltet. Hierzu gehört auch die Umwandlung der alten Elementfassade in eine moderne Doppelfassade. Dies geschieht unter strengen Auflagen des Denkmalschutzes: das äußere Erscheinungsbild muss unverändert bleiben. Eine Besonderheit sind die eng gebogenen Dreifach‐Isolierverglasungen an den Gebäudeecken, welche nur teilweise durch die aktuellen Regelungen der TRLV bzw. der DIN 18008 abgedeckt sind.

Energy Efficient Rehabilitation of the Hypo Hochhaus – Curved Triple Insulation Glass Unit of the New Double Skin Facade. The high rised building of “Hypo‐Vereinsbank” in Munich, erected 1981 and a landmark in Munich is at present under rehabilitation. To get a green building, amongst other topics the old facade is replaced by a modern double skin facade. The building is classified as a historic monument, meaning that renovation is subject to strict conditions. The outer appearance of the building has to remain unchanged. Remarkable features of the building are the curved insulation glass units at the edges, which are only partially covered by the German regulations for glass.
Fassaden, Glasbauplanung in China
Authors: Lutz Martin , Schenke David
Published: April 2014

Der größte Wachstumsmarkt der Welt sichert dem Exportland Deutschland eine anhaltende Wirtschaftsstabilität. 50 % des Weltbauvolumens der nächsten 10 bis 15 Jahre werden in China realisiert. Der Bauboom setzt sich in den uns weitgehend unbekannten 20 bis 30 “Kleinstädten” mit 5 bis 10 Millionen Einwohnern fort. Eine Chance für deutsche Architektur‐ und Engineering‐Büros. Der Beitrag zeigt auf, welche Chancen der chinesische Fassaden‐ und Glasbaumarkt bietet, ebenso was in China möglich ist und was nicht möglich ist, dies sowohl theoretisch als auch anhand von geplanten Beispielprojekten in China.

Facades, glass construction in China. The world’s largest emerging market secures a lasting stability for Germany’s export economy. 50 % of the global construction activity of the coming 10 to 15 years will take place in China. The construction boom continues in the 20 to 30 ‘smaller cities’ with 5 to 10 million inhabitants which are commonly unknown to us. This represents a chance for German architecture and engineering practices. The article outlines the chances which lie within the Chinese facade‐ and glass construction market and furthermore shows what is possible or impossible, in theory as well as by referring to practical examples of current design projects in China.
Aussteifende Holz‐Glas‐Fassaden – Aussteifungssysteme und Nachweise
Authors: Fadai1 Alireza , Winter Wolfgang
Published: April 2014

Glas wird oft lastabtragend eingesetzt, wobei aus Gründen der Sicherheit und des Tragverhaltens Laminate zum Einsatz kommen. Insbesondere kalt gebogene, durch Lamination formstabilisierte Gläser sind ein zunehmend nachgefragtes Produkt. Herstellungsprozess und Nutzung führen in solchen Laminaten zu teils unbekannten Spannungen, welche die Aufnahme äußerer Einwirkungen begrenzen. Optische Messverfahren mit polarisiertem Licht erlauben keine Erfassung dieser Spannungen. Dünne, innen auf die Gläser geklebte faseroptische Sensoren stellen eine mögliche Lösung dar: In Versuchen an kalt gebogenen Gläsern wird gezeigt, dass optische Sensorik dem Laminationsprozess standhält und sich für kontinuierliche Dehnungsmessungen in Glaslaminaten eignet.

Fibre Optical Sensors for Strain Measurement in Cold Bent Glass Laminates. Many glass products, e.g. for structural application, are conceived as laminates for safety and load bearing behaviour reasons. Cold bent glass with shape preservation by lamination is another, increasingly popular technique. Due to manufacturing and application, such laminates can be subjected to unknown, varying interior stresses limiting the additional load bearing capacity. Optical measurement based on polarised light does not permit to determine these stresses. Thin, barely visible fibre optical sensors, glued to the interior glass surfaces, are a possible solution. R

Das Bauwesen ist generell gegenüber tragenden Verklebungen skeptisch. Die Gründe sind u.a. die Größe der Bauteile und der zu übertragenden Lasten sowie die Anforderungen an Langzeitverhalten und an Auswechselbarkeit. In den letzten Jahren wurde intensiv im Bereich Holz‐Koppelrahmen geforscht und versucht an die ETAG 002 [1] angelehnte Qualitätskriterien und Bemessungsverfahren zu entwickeln. So können nach den heutigen Stand der Technik mit Glas verklebte Holz‐Koppelleisten ökonomisch und ökologisch mit metallischen Profilen konkurrieren. Die bisherigen Lösungen für kleine Bauten weiterzuentwickeln und auf mehrgeschossige aussteifende Fassadenteile zu übertragen, ist das Thema mehrerer Forschungsarbeiten und Pilotprojekte, welche in diesem Aufsatz behandelt werden.

Stiffening timber‐glass façades ‐ Stiffening systems and design procedure. The structural sealant glazing is largely used in the automobile industry; the building sector is more reluctant mainly because of the long‐term behavior and the stresses due to different thermic elongations of glass and metal profiles. Materials with comparable thermic elongations to glass as wood‐based profiles are not already included in the relevant Technical guideline ETAG 002 [1]. Nevertheless, there exist considerable bonding experience in the field of windows and structural applications. During the last years, different types of wood‐based coupling frames had been developed and tested. The quality criteria and design rules based on the ETAG 002 had been proposed. This paper reports on several new research and pilot projects using new developed timber‐glass facades.
Innovative Glaskonstruktionen im historischen Kontext, Schloss Grimma
Authors: Voit Katharina , Tückmantel Peter , Nicklisch Felix , Kahlert Wolfgang
Published: April 2014

Im Zuge des Umbaus und der Sanierung des Schlosses Grimma wurde ein gleichermaßen architektonisch sowie bautechnisch innovatives Konzept umgesetzt. Mit dem Ziel, das denkmalgeschützte Ensemble erlebbar zu machen, wurden drei neue Baukörper als filigrane Ganzglaskonstruktionen in die historische Schlossanlage eingefügt: ein gläserner Treppenturm, Eingangsbereich und Verbindungsgang. Das Herzstück des Gebäudekomplexes – der lichtdurchflutete Eingangsbereich – verknüpft die historischen Gebäude Kornhaus, Kornhausanbau und Schloss durch den gläsernen Verbindungsgang. Heute treffen moderne Ergänzungsbauten als innovative Glaskonstruktionen auf historische Gebäudeteile.

Historic Castle meets modern glass construction. The castle of the German city Grimma, one of the most secular monuments in the heart of the Free State of Saxony, was restored and redeveloped. In the course of the reconstruction of the castle complex, an architectural as well as constructional innovative concept was implemented. Three additional glass buildings were integrated in order to revive this landmark: a new stair tower, foyer and walkway. Not only façade and roof show the central design idea of transparency, but also the supporting framework. The light‐flooded foyer represents the centerpiece, and connects the historical buildings. Thus, innovative glazed structure meets historical buildings today.
Analysis of epistemic uncertainty for the friction‐induced vibration
Authors: Hanselowski A. , Hanss M.
Published: April 2014

The phenomenon of brake squeal, which is a type of friction‐induced vibration, is analyzed using a pin‐on‐disc system. For this purpose, a finite element model is derived and its parameters are updated on the basis of experiments. The FEM analysis includes the complex eigenvalue analysis and the transient analysis. As the brake‐squeal phenomenon is very sensitive with respect to parametric uncertainty, the two numerical analyses are combined with an uncertainty analysis, which in this study is based on fuzzy arithmetic. The uncertainty analysis enables the determination of both the overall uncertainty of the considered output quantity and the influence of each individual uncertain model parameter on the overall uncertainty of the output. With this information about propagation and influence of parametric uncertainty in the system, the methods of complex eigenvalue analysis and transient analysis can be compared with respect to their appropriateness for predicting the tendency of the brake to squeal.
The Theology of an Evolutionist
Authors: Abbott Lyman
Published: April 2014

A Congregationalist clergyman, editor of the influential progressive journal The Outlook, and intimate with Henry Ward Beecher and Theodore Roosevelt, Lymon Abbott (1835–1922) played a central role in religion and politics in turn-of-the-century America. In this work, first published in 1897, Abbott shows his characteristic optimism in human moral development, arguing that the Christian faith can fully accommodate evolution as the means by which God changes and improves the world over time. Abbott writes 'not to disbelievers in evolution to prove that they are mistaken, but to believers in evolution to show them that their belief is not inconsistent with the Christian faith'. A companion to Abbott's popular previous work The Evolution of Christianity (also reissued in the Cambridge Library Collection), this text presents an innovative and often elegant reconciliation of the ongoing debate concerning scientific empiricism and Christian belief.
The Book of the Farm
Authors: Stephens Henry
Published: April 2014

Henry Stephens (1795–1874) was a farmer and later a writer on agriculture. After attending lectures on chemistry and agriculture at the University of Edinburgh he boarded with a Berwickshire farmer, George Brown, and gained experience of agricultural work. In 1820 Stephens acquired his own farm, on which he used modern and experimental farming methods. In 1837 he sold the farm, and devoted the rest of his life to writing guides to farming for the use of inexperienced farmers. These influential volumes, first published in 1842, contain Stephens' detailed descriptions of contemporary farming practices. He describes in meticulous detail all aspects of farming, including livestock care and slaughter, dairying, irrigation practices and crop culture. Arranged by season and including copious high-quality illustrations of farming equipment, these extremely popular and fascinating volumes were considered the standard work on practical Victorian agriculture. Volume 2 describes farming tasks performed in spring.
A History of Eighteenth-Century Literature (1660–1780)
Authors: Gosse Edmund
Published: April 2014

This work by Edmund Gosse (1849–1928) was commissioned by Macmillan as the third volume in a series of literary histories, and published in 1889, when literary criticism was still a relatively new field of academic study. His earlier work had led to his appointment as Lecturer at Trinity College, Cambridge, in 1884 and to a hugely popular American lecture tour that same year. An established poet, author and critic, Gosse had a loyal following within the literary establishment of Cambridge and London, despite lacking formal academic qualifications. His approach to analysis was through personal impressions, and discussions of the biographies as well as output of a wide range of writers from Dryden to Johnson. Reviewers noted his identification of the years 1660–1780 as being central to the beginnings of the novel and the concern to 'reform and regulate ordinary writing', and praised his comparison of English and Continental literature.
Recherches sur la théorie des surfaces élastiques
Authors: Germain Sophie
Published: April 2014

Sophie Germain (1776–1831) was one of the first distinguished female mathematicians of the modern era. Largely self-taught, she won the admiration and friendship of Legendre and Gauss (whose work also appears in this series). Germain is best known for her work on number theory, notably Fermat's Last Theorem, but she played an important part in establishing the foundations of elasticity. This book, described by her slightly younger contemporary Navier as 'a work which few men are able to read and which only one woman was able to write', contains her research on the topic, which was awarded a prize by the Paris Academy of Sciences. This work was published in Paris in 1821.
Slavery
Authors: Channing William Ellery
Published: April 2014

In the years preceding the American Civil War, religion was at the heart of the debate over slavery. William Ellery Channing (1780–1842) had rejected the strict Calvinism of his background to become the leading Unitarian spokesman and preacher, and in later life he began to address the subject of slavery. Published in 1836, this work was Channing's most substantial contribution to the debate, revealing the real difficulties men such as Channing had in questioning a practice with which they had grown up. He vacillates between contempt for the institution and empathy for the slaveholders, writing, 'I do not intend to pass sentence on the character of the slave-holder.' He sees black slaves as humans, but not of equal status with white people. The final chapter is particularly prescient: 'There is a great dread … that the union of the States may be dissolved by the conflict about slavery.'
Exposé de la religion des Druzes
Authors: Silvestre de Sacy Antoine Isaac
Published: April 2014

Antoine Isaac Silvestre de Sacy (1758–1838), the most distinguished French orientalist of his time, is considered the father of Arab scholarship in Europe. He had a lifelong interest in a little-known religious community, the Druze, which emerged in the eleventh century as an Ismaili schismatic movement. De Sacy's monumental study was begun in the 1790s, when he translated some of the Druze scriptures from Arabic to French. Such was his commitment to learning more about the Druze that he waited forty years before publishing this two-volume work in 1838, as he hoped to uncover further source material. It offers pioneering insight into the religious system founded by Hamza ibn-'Ali ibn-Ahmad during the reign of the caliph al-Hakim bi-Amr Allah. Volume 1 looks at the early history and doctrines of the Ismaili movement before expanding on the reign of al-Hakim (996–1021).
Shakespeare in the Theatre
Authors: Poel William
Published: April 2014

William Poel (1852–1934), actor, director and author, began his acting career in 1876, deliberately choosing provincial touring in order to learn his craft. After a period as manager of the Royal Victoria Hall and Coffee Tavern (later the Old Vic), he worked as stage manager for the actor-manager Frank Benson. In the 1890s he founded the Elizabethan Stage Society in order to demonstrate his fervent belief that only a return to Elizabethan performance methods would enable a true understanding of Shakespeare's plays. This was to have a profound influence on modern productions, with directors such as Tyrone Guthrie and John Gielgud adopting his ideals rather than his often idiosyncratic practices. Moreover, his long-held wish for a replica of the Globe Theatre has since become a reality. Poel was also a prolific author and this work, first published in 1913, explores his philosophy by bringing together four articles on the staging of Shakespeare.
Characteristics of air entrainment during dynamic wetting failure along a planar substrate
Authors: Vandre E. , Carvalho M. S. , Kumar S.
Published: April 2014

Characteristic substrate speeds and meniscus shapes associated with the onset of air entrainment are studied during dynamic wetting failure along a planar substrate. Using high-speed video, the behaviour of the dynamic contact line (DCL) is recorded as a tape substrate is drawn through a bath of a glycerol/water solution. Air entrainment is identified by triangular air films that elongate from the DCL above some critical substrate speed. Meniscus confinement within a narrow gap between the substrate and a stationary plate is shown to delay air entrainment to higher speeds for a wide range of liquid viscosities, expanding upon the findings of Vandre, Carvalho & Kumar (J. Fluid Mech., vol. 707, 2012, pp. 496–520). A pressurized liquid reservoir controls the meniscus position within the confinement gap. It is found that liquid pressurization further postpones air entrainment when the meniscus is located near a sharp corner along the stationary plate. Meniscus shapes recorded near the DCL demonstrate that operating conditions influence the size of entrained air films, with smaller films appearing in the more viscous solutions. Regardless of size, air films become unstable to thickness perturbations and ultimately rupture, leading to the entrainment of air bubbles. Recorded critical speeds and air-film sizes compare well to predictions from a hydrodynamic model for dynamic wetting failure, suggesting that strong air stresses near the DCL trigger the onset of air entrainment.
Turbulent flow over superhydrophobic surfaces with streamwise grooves
Authors: Türk S. , Daschiel G. , Stroh A. , Hasegawa Y. , Frohnapfel B.
Published: April 2014

We investigate the effects of superhydrophobic surfaces (SHS) carrying streamwise grooves on the flow dynamics and the resultant drag reduction in a fully developed turbulent channel flow. The SHS is modelled as a flat boundary with alternating no-slip and free-slip conditions, and a series of direct numerical simulations is performed with systematically changing the spanwise periodicity of the streamwise grooves. In all computations, a constant pressure gradient condition is employed, so that the drag reduction effect is manifested by an increase of the bulk mean velocity. To capture the flow properties that are induced by the non-homogeneous boundary conditions the instantaneous turbulent flow is decomposed into the spatial-mean, coherent and random components. It is observed that the alternating no-slip and free-slip boundary conditions lead to the generation of Prandtl’s second kind of secondary flow characterized by coherent streamwise vortices. A mathematical relationship between the bulk mean velocity and different dynamical contributions, i.e. the effective slip length and additional turbulent losses over slip surfaces, reveals that the increase of the bulk mean velocity is mainly governed by the effective slip length. For a small spanwise periodicity of the streamwise grooves, the effective slip length in a turbulent flow agrees well with the analytical solution for laminar flows. Once the spanwise width of the free-slip area becomes larger than approximately 20 wall units, however, the effective slip length is significantly reduced from the laminar value due to the mixing caused by the underlying turbulence and secondary flow. Based on these results, we develop a simple model that allows estimating the gain due to a SHS in turbulent flows at practically high Reynolds numbers.
Gender Equality in the Ivory Tower, and How Best to Achieve It
Authors: Monroe Kristen Renwick , Choi Jenny , Howell Emily , Lampros-Monroe Chloe , Trejo Crystal , Perez Valentina
Published: April 2014

Both statistical and qualitative interview data confirm the on-going existence of gender inequality within American academia, with women both underrepresented and underpaid compared to their male counterparts. Surprisingly, what is needed to remedy this situation is not a secret. Most of the policies outlined in this article as good workable solutions are programs that have been tested and described in more than one study. Indeed, evidence suggests that when the nine strategies we identify here are fully implemented, as they have been at a few colleges and universities, the number of women on the faculty increases dramatically. The fact that we do not adopt these policies more widely in academia suggests not a lack of knowledge so much as apathy, prejudice, gender stereotypes, and cultural cues that end by depriving society of some of its best talent and energy.
Encountering Resistance: Qualitative Insights from the Quantitative Sampling of Ex-Combatants in Timor-Leste
Authors: Roll Kate
Published: April 2014

This article highlights the contribution of randomized, quantitative sampling techniques to answeringqualitativequestions posed by the study. In short it asks: what qualitative insights do we derive from quantitative sampling processes? Rather than simply being a means to an end, I argue the sampling process itself generated data. More specifically, seeking out more than 220 geographically dispersed individuals, selected though a randomized cluster sample, resulted in the identification of relationship patterns, highlighted extant resistance-era hierarchies and patronage networks, as well as necessitated deeper, critical engagement with the sampling framework. While this discussion is focused on the study of former resistance members in Timor-Leste, these methodological insights are broadly relevant to researchers using mixed methods to study former combatants or other networked social movements.
Polymorph-dependent titanium dioxide nanoparticle dissolution in acidic and alkali digestions
Authors: Silva R. G. , Nadagouda M. N. , Patterson C. L. , Panguluri Srinivas , Luxton T. P. , Sahle-Demessie E. , Impellitteri C. A.
Published: April 2014

Multiple polymorphs (anatase, brookite and rutile) of titanium dioxide nanoparticles (TiO2-NPs) with variable structures were quantified in environmental matrices via microwave-based hydrofluoric (HF) and nitric (HNO3) mixed acid digestion and muffle furnace (MF)-based potassium hydroxide (KOH) fusion.
Facile synthesis of yolk–shell structured Si–C nanocomposites as anodes for lithium-ion batteries
Authors: Pan Lei , Wang Haibin , Gao Dacheng , Chen Shengyang , Tan Lei , Li Lei
Published: April 2014

A new method to synthesize yolk–shell structured Si–C nanocomposites as anodes for lithium-ion batteries was reported.
Towards covalent organic frameworks with predesignable and aligned open docking sites
Authors: Chen Xiong , Huang Ning , Gao Jia , Xu Hong , Xu Fei , Jiang Donglin
Published: April 2014

Covalent organic frameworks were developed to hold predesignable and aligned binding sites on the channel walls for supramolecular architecture.
Z′ = 2 crystallization of the three isomeric piridinoylhydrazone derivatives of isosteviol
Authors: Lodochnikova Olga A. , Dobrynin Alexey B. , Andreeva Olga V. , Strobykina Irina Yu. , Kataev Vladimir E. , Litvinov Igor A.
Published: April 2014

Inclusion of an “extra” molecule in a unit cell as a “cost” of transferring a robust mirror-symmetrical H-bonding motif from a racemic environment into a homochiral one was presented.
Can picolinamide be a promising cocrystal former?
Authors: Chan H. C. Stephen , Woollam Grahame R. , Wagner Trixie , Schmidt Martin U. , Lewis Richard A.
Published: April 2014

Picolinamide was shown to demonstrate the potential to be a promising cocrystal former. 8 novel cocrystals were found.
Excitonic energy transfer in polymer wrapped carbon nanotubes in gradually grown nanoassemblies
Authors: Karachevtsev Victor A. , Plokhotnichenko Alexander M. , Glamazda Alexander Yu. , Leontiev Victor S. , Levitsky Igor A.
Published: April 2014

We investigate the exciton energy transfer (ET) in nanoassemblies (nanotube based aggregates) formed by polymer wrapped single walled carbon nanotubes (SWNTs) using photoluminescence (PL) spectroscopy and simulation.
Conversion of furfuryl alcohol into 2-methylfuran at room temperature using Pd/TiO2 catalyst
Authors: Iqbal Sarwat , Liu Xi , Aldosari Obaid F. , Miedziak Peter J. , Edwards Jennifer K. , Brett Gemma L. , Akram Adeeba , King Gavin M. , Davies Thomas E. , Morgan David J. , Knight David K. , Hutchings Graham J.
Published: April 2014

The selective hydrogenation of furfuryl alcohol into 2-methylfuran was investigated at room temperature using palladium supported catalysts.
Microfluidic investigation of the deposition of asphaltenes in porous media
Authors: Hu Chuntian , Morris James E. , Hartman Ryan L.
Published: April 2014

The deposition of asphaltenes in porous media, an important problem in science and macromolecular engineering, was for the first time investigated in a transparent packed-bed microreactor with online analytics that generated high-throughput information.
Cationic and anionic reverse micelles as the molecular crowding container for G-quadruplex structure
Authors: Ho Meng-Chieh , Chang Chih-Wei
Published: April 2014

The d[AG3(T2AG3)3] sequence shows different molecular crowding effects in AOT and CTAB reverse micelles (RMs). Our result indicates that the CTAB RMs are ideal molecular crowding containers for G-quadruplex structure.
Effect of surfactants on the performance of tubular and spherical micromotors – a comparative study
Authors: Simmchen Juliane , Magdanz Veronika , Sanchez Samuel , Chokmaviroj Sarocha , Ruiz-Molina Daniel , Baeza Alejandro , Schmidt Oliver G.
Published: April 2014

Systematic comparative study on the effect of different surfactants on the motion of tubular and spherical micromotors.
Ultrabright NIR fluorescent mesoporous silica nanoparticles
Authors: Palantavida S. , Tang R. , Sudlow G. P. , Akers W. J. , Achilefu S. , Sokolov I.
Published: April 2014

Unusually bright fluorescent near-infrared water-dispersible silica nanoparticles suitable for biomedical imaging are described and studied.
Polarizability effects on the structure and dynamics of ionic liquids
Authors: Cavalcante Ary de Oliveira , Ribeiro Mauro C. C. , Skaf Munir S.
Published: April 2014

Polarization effects on the structure and dynamics of ionic liquids are investigated using molecular dynamics simulations. Four different ionic liquids were simulated, formed by the anions Cl− and PF6−, treated as single fixed charge sites, and the 1-n-alkyl-3-methylimidazolium cations (1-ethyl and 1-butyl-), which are polarizable. The partial charge fluctuation of the cations is provided by the electronegativity equalization model (EEM) and a complete parameter set for the cations electronegativity (χ) and hardness (J) is presented. Results obtained from a non-polarizable model for the cations are also reported for comparison. Relative to the fixed charged model, the equilibrium structure of the first solvation shell around the imidazolium cations shows that inclusion of EEM polarization forces brings cations closer to each other and that anions are preferentially distributed above and below the plane of the imidazolium ring. The polarizable model yields faster translational and reorientational dynamics than the fixed charges model in the rotational-diffusion regime. In this sense, the polarizable model dynamics is in better agreement with the experimental data.
Cooperative polymerization of one-patch colloids
Authors: Vissers Teun , Smallenburg Frank , Munaò Gianmarco , Preisler Zdeněk , Sciortino Francesco
Published: April 2014

We numerically investigate cooperative polymerization in an off-lattice model based on a pairwise additive potential using particles with a single attractive patch that covers 30% of the colloid surface. Upon cooling, these particles self-assemble into small clusters which, below a density-dependent temperature, spontaneously reorganize into long straight tubes. We evaluate the partition functions of clusters of all sizes to provide an accurate description of the chemical reaction constants governing this process. Our calculations show that, for intermediate sizes, the partition functions retain contributions from two different structures, differing in both energy and entropy. We illustrate the microscopic mechanism behind the complex polymerization process in this system and provide a detailed evaluation of its thermodynamics.
Dielectric relaxations and alternating current conductivity in manganese substituted cobalt ferrite
Authors: Kolekar Y. D. , Sanchez L. J. , Ramana C. V.
Published: April 2014

Manganese (Mn) substituted cobalt ferrites (CoFe2-xMnxO4, referred to CFMO) have been synthesized by the solid state reaction method and their dielectric properties and ac conductivity have been evaluated as a function of applied frequency and temperature. X-ray diffraction measurements indicate that CFMO crystallize in the inverse cubic spinel phase with a lattice constant ∼8.38 Å. Frequency dependent dielectric measurements at room temperature obey the modified Debye model with relaxation time of 10−4 s and spreading factor of 0.35(±0.05). The frequency (20 Hz–1 MHz) and temperature (T = 300–900 K) dependent dielectric constant analyses indicate that CFMO exhibit two dielectric relaxations at lower frequencies (1–10 kHz), while completely single dielectric relaxation for higher frequencies (100 kHz–1 MHz). The dielectric constant of CFMO is T-independent up to ∼400 K, at which point increasing trend prevails. The dielectric constant increase with T > 400 K is explained through impedance spectroscopy assuming a two-layer model, where low-resistive grains separated from each other by high-resistive grain boundaries. Following this model, the two electrical responses in impedance formalism are attributed to the grain and grain-boundary effects, respectively, which also satisfactorily accounts for the two dielectric relaxations. The capacitance of the bulk of the grain determined from impedance analyses is ∼10 pF, which remains constant with T, while the grain-boundary capacitance increases up to ∼3.5 nF with increasing T. The tan δ (loss tangent)-T also reveals the typical behavior of relaxation losses in CFMO.
Theory of third-order spectroscopic methods to extract detailed molecular orientational dynamics for planar surfaces and other uniaxial systems
Authors: Nishida Jun , Fayer Michael D.
Published: April 2014

Functionalized organic monolayers deposited on planar two-dimensional surfaces are important systems for studying ultrafast orientational motions and structures of interfacial molecules. Several studies have successfully observed the orientational relaxation of functionalized monolayers by fluorescence depolarization experiments and recently by polarization-resolved heterodyne detected vibrational transient grating (HDTG) experiments. In this article we provide a model-independent theory to extract orientational correlation functions unique to interfacial molecules and other uniaxial systems based on polarization-resolved resonant third-order spectroscopies, such as pump-probe spectroscopy, HDTG spectroscopy, and fluorescence depolarization experiment. It will be shown (in the small beam-crossing angle limit) that five measurements are necessary to completely characterize the monolayer's motions: I∥(t) and I⊥(t) with the incident beams normal to the surface, I∥(t) and I⊥(t) with a non-zero incident angle, and a time averaged linear dichroism measurement. Once these measurements are performed, two orientational correlation functions corresponding to in-plane and out-of-plane motions are obtained. The procedure is applicable not only for monolayers on flat surfaces, but any samples with uniaxial symmetry such as uniaxial liquid crystals and aligned planar bilayers. The theory is valid regardless of the nature of the actual molecular motions on interface. We then apply the general results to wobbling-in-a-cone model, in which molecular motions are restricted to a limited range of angles. Within the context of the model, the cone angle, the tilt of the cone relative to the surface normal, and the orientational diffusion constant can be determined. The results are extended to describe analysis of experiments where the beams are not crossing in the small angle limit.
Magnetic properties and hyperfine interactions in Cr8, Cr7Cd, and Cr7Ni molecular rings from 19F-NMR
Authors: Bordonali L. , Garlatti E. , Casadei C. M. , Furukawa Y. , Lascialfari A. , Carretta S. , Troiani F. , Timco G. , Winpenny R. E. P. , Borsa F.
Published: April 2014

A detailed experimental investigation of the 19F nuclear magnetic resonance is made on single crystals of the homometallic Cr8 antiferromagnetic molecular ring and heterometallic Cr7Cd and Cr7Ni rings in the low temperature ground state. Since the F− ion is located midway between neighboring magnetic metal ions in the ring, the 19F-NMR spectra yield information about the local electronic spin density and 19F hyperfine interactions. In Cr8, where the ground state is a singlet with total spin ST = 0, the 19F-NMR spectra at 1.7 K and low external magnetic field display a single narrow line, while when the magnetic field is increased towards the first level crossing field, satellite lines appear in the 19F-NMR spectrum, indicating a progressive increase in the Boltzmann population of the first excited state ST = 1. In the heterometallic rings, Cr7Cd and Cr7Ni, whose ground state is magnetic with ST = 3/2 and ST = 1/2, respectively, the 19F-NMR spectrum has a complicated structure which depends on the strength and orientation of the magnetic field, due to both isotropic and anisotropic transferred hyperfine interactions and classical dipolar interactions. From the 19F-NMR spectra in single crystals we estimated the transferred hyperfine constants for both the F−-Ni2+ and the F−-Cd2+ bonds. The values of the hyperfine constants compare well to the ones known for F−-Ni2+ in KNiF3 and NiF2 and for F−-Cr3+ in K2NaCrF6. The results are discussed in terms of hybridization of the 2s, 2p orbitals of the F− ion and the d orbitals of the magnetic ion. Finally, we discuss the implications of our results for the electron-spin decoherence.
Jet impingement and the hydraulic jump on horizontal surfaces with anisotropic slip
Authors: Prince Joseph F. , Maynes Daniel , Crockett Julie
Published: April 2014

This paper presents an analysis that describes the dynamics of laminar liquid jet impingement on horizontal surfaces with anisotropic slip. Due to slip at the surface and the anisotropy of its magnitude, the overall behavior departs notably from classical results. For the scenario considered the slip length varies as a function of the azimuthal coordinate and describes superhydrophobic surfaces micropatterned with alternating ribs and cavities. The thin film dynamics are modeled by a radial momentum analysis for a given jet Reynolds number and specified slip length and the influence of slip on the entire flow field is significant. In an average sense the thin film dynamics exhibit similarities to behavior that exists for a surface with isotropic slip. However, there are also important deviations that are a direct result of the azimuthally varying slip and these become more pronounced at higher Reynolds numbers and at greater slip lengths. The analysis also allows determination of the azimuthally varying radial location of the hydraulic jump that forms due to an imposed downstream depth. Departure from the no slip case and from the scenario of isotropic slip is characterized over a range of jet Reynolds numbers and realistic slip length values. The results show that for all cases the hydraulic jump is elliptical, with eccentricity increasing as the Reynolds number or slip length increases, or as the downstream depth decreases. The radial location of the hydraulic jump is greatest in the direction of greatest slip (parallel to the microribs), while it is a minimum in the direction transverse to the rib/cavity structures. The model results for the hydraulic jump radial position are compared to experimental measurements with good agreement.
Note: Nonlinear susceptibility from high DC field torque magnetometry
Authors: Shivaram B. S.
Published: April 2014

Torque magnetometry is a convenient technique to measure the magnetic properties of anisotropic materials. Advances in micromachining have made torque magnetometers precise and reliable even in adverse conditions such as very high magnetic fields and very low temperatures. In most applications with such magnetometers the measured torque signals are used to arrive at the linear magnetic susceptibility. In this short note we extend torque magnetometry to measure nonlinear susceptibilities and illustrate our methods with representative data on the heavy fermion compound UPt3.