bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Poly(propylene) Superhydrophobic Surfaces by Functionalised TiO2 Nanoparticles: Effect of Solvents and Dipping Times
Authors: Chagas Gabriela Ramos , Weibel Daniel Eduardo 
Published: October 2014

SummaryWe present a simple strategy for the fabrication of poly(propylene) (PP) superhydrophobic surfaces, i.e., surfaces that show water contact angle (WCA) ≥ 150° after a simple dipping process. Injection‐moulded PP samples were coated with titanium dioxide nanoparticles previously functionalised with trimethoxy propyl silane. Water, ethanol or xylene were used as solvents in the nanoparticles' suspensions. The prepared superhydrophobic surfaces were characterised by WCA, FTIR‐ATR, SEM and profilometry measurements. PP coated samples showed very low wettability, with WCAs higher than 150° when xylene was used as a solvent. The combination of increasing the surface roughness via dipping coating process plus the low surface tension of the coating produced the final superhydrophobic PP substrates.
Evaluation of Fracture Toughness of UHMWPE Used in Orthopaedic Implants Through Essential Work of Fracture
Authors: Santos Rubens E. dos , Finocchio Henrique , Kobayashi Marcio , Ambrosio José D. , Bolfanini Claudemiro 
Published: October 2014

SummaryThis study investigates the use of the essential work of fracture (EWF) test in UHMWPE for use in orthopedic implants. A simplest method to produce the notch and initial crack was used. The validity of the fracture toughness results obtained by this method was investigated to evaluate the possibility of using this technique in obtaining data for the design of orthopedic prostheses.
Waterborne Acrylic‐Casein Nanoparticles. Nucleation and Grafting
Authors: Picchio Matías L. , Minari Roque J. , Gonzalez Veronica D. G. , Passeggi Mario C.G. , Vega Jorge R. , Barandiaran María J. , Gugliotta Luis M. 
Published: October 2014

SummaryHybrid nanoparticles containing proteins have a technological interest because they attempt to achieve improved properties with respect to the single materials by chemically linking both components. In this article, the batch emulsion polymerization of methyl methacrylate in the presence of varied concentration of casein and tert‐butyl hydroperoxide as initiator was investigated. A detailed characterization of the molecular microstructure and morphology of the hybrid nanoparticles allowed the identification of two competitive particle formation mechanisms. Compatibilized nanoparticles were produced at the beginning of the polymerization, while uncompatibilized particles could be generated by a second way of nucleation, which is promoted by the ungrafted protein and depends on its concentration.
In‐Line Monitoring of Size Distributions in Liquid‐Liquid Dispersions and Suspension Polymerizations by Focused Beam Reflectance Measurements
Authors: Poblete Israel Bernardo , Castor Carlos Alberto , Nele Marcio , Pinto José Carlos 
Published: October 2014

SummaryThis work studies the use of Focused Beam Reflectance Measurements (FBRM) for monitoring of size distributions in liquid‐liquid (styrene‐water) dispersions and styrene suspension polymerizations performed in stirred tanks. The effects of the suspending agent concentration, stirring rate and presence of external light sources on the FBRM performance were evaluated during the in‐line monitoring of average size chords and chord length distribution (CLD). It can be stated that FBRM is sensitive to variations of particle sizes and, therefore, that FBRM is suitable for evaluation of CLDs in real time in suspension polymerization systems.
GRAPPA reconstruction with spatially varying calibration of self‐constraint
Authors: Xu Lin , Guo Li , Liu Xiaoyun , Kang Lili , Chen Wufan , Feng Yanqiu 
Published: October 2014

PurposeTo develop and evaluate a novel method of generalized auto‐calibrating partially parallel acquisition (GRAPPA) with spatially varying calibration of self‐constraint for parallel magnetic resonance imaging (MRI) reconstruction.Theory and MethodsThe conventional GRAPPA independently estimates each missing sample with adjacent acquired data over multiple coils, thereby ignoring correlations inside missing data. Self‐constrained methods can exploit correlations inside missing data by imposing linear dependence within full neighborhood kernels and showing improved reconstruction compared with GRAPPA. However, self‐constraint kernels are currently calibrated by using auto‐calibration signals. Thus, they may be suboptimal for reconstructing outer k‐space because of spatially varying correlations. This study proposes a novel GRAPPA method with separate self‐constraints (SSC‐GRAPPA). In this method, the spatially varying self‐constraint coefficients are adaptively calibrated by separately exploiting correlations inside missing and acquired data in the outer k‐space. Both phantom and in vivo imaging experiments were conducted with retrospective undersampling to evaluate the performance of the proposed method.ResultsCompared with GRAPPA and self‐constrained GRAPPA, the proposed SSC‐GRAPPA generates images with reduced artifacts and noise.ConclusionThe proposed method provides an effective and efficient approach to improve parallel MRI reconstruction, and has potential to benefit routine clinical practice in the future. Magn Reson Med 74:1057–1069, 2015. © 2014 Wiley Periodicals, Inc.
Vertical impedance of an end‐bearing pile in viscoelastic soil
Authors: Zheng Changjie , Ding Xuanming , Li Ping , Fu Qiang 
Published: October 2014

SummaryThis paper presents a new method to derive the analytical solution for the vertical impedance of an end‐bearing pile in viscoelastic soil. The soil is assumed as a homogeneous and isotropic layer, and the pile is considered as a one‐dimensional Euler rod. Considering both the vertical and radial displacements of soil and soil–pile coupled vibration, the governing equations of the soil and pile are established. The volumetric strain of soil is obtained by transformation on the equations of soil and variable separation method. Then the vertical and radial displacements of soil are obtained accordingly. The displacement response and impedance function of pile are derived based on the continuity assumption of the displacement and stress between the pile and soil. The solution is verified by being compared with an existing solution obtained by introducing potential functions. Furthermore, a comparison with two other simplified solutions is conducted. Numerical examples are presented to analyze the vibration characteristics of the pile. Copyright © 2014 John Wiley & Sons, Ltd.
High­Speed­Bildverarbeitung für sicherere Fahrzeuge
Authors: Godding Robert , Dose Wibke 
Published: October 2014

AbstractAutohersteller müssen schon während der Entwicklungsphase von Neufahrzeugen verschiedenste Anforderungen bezüglich Fahrdynamik, Sicherheit und Bauteilen berücksichtigen. Zudem werden Produkt‐ und Entwicklungszyklen immer kürzer. Daher müssen auch Fahrzeugtests immer effizienter werden. Von den bei diesen Tests verwendeten Messsystemen werden Portabilität, kurze Rüstzeiten, ausfallsicherer Betrieb sowie zuverlässige und hochpräzise Ergebnisse erwartet. Für viele Anwendungen der geometrischen Vermessung eignen sich optische Messsysteme besonders – auch für Tests bei hohen Geschwindigkeiten.
Exakt und intuitiv mikroskopieren
Authors: Kassen Folkert 
Published: October 2014

AbstractBiowissenschaften, Medizin und Pharmaforschung stellen immer höhere Anforderungen an die optische Auflösung in der Mikroskopie. Neue bildgebende Verfahren tragen dazu bei, dass sich Details immer höher aufgelöst darstellen lassen, auch unterhalb der Beugungsgrenze des Lichts. Fluoreszenzmikroskopie ermöglicht die Kennzeichnung von unterschiedlichen Bereichen oder Körpern (3D‐Mikroskopie) auch bei lebenden Objekten. Sobald die zu untersuchenden Objekte größer sind als das Bildfeld, muss das Objekt präzise verschoben werden. Bei größeren Bereichen (mosaicing or stitching) kommt ein hochpräziser Scanningtisch zum Einsatz. Je genauer dieser positioniert, um so schneller und sicherer können die einzelnen Bilder im Rechner aneinandergereiht und Artefakte vermieden werden. Schnelles Positionieren ist von großem Vorteil, wenn der Durchsatz beim Digitalisieren erhöht werden muss.
High‐Speed‐Datenverbindungen mit Silizium‐Photonik
Authors: Absil Philippe 
Published: October 2014

AbstractDie Marktaussichten für die Silizium (Si)‐Photonik sind ausgezeichnet. Deswegen würde eine Plattform zur Integration von Si‐Photonik‐Bausteinen, die hoch qualitative passive und aktive Komponenten in einem einzigen Designfluss ermöglicht, die Implementierung von Si‐Photonik‐Bausteinen vorantreiben. Auf einer solchen Plattform ließen sich integrierte photonische Schaltungen für die Telecom‐ und Datacom‐Industrie mit Übertragungsraten von 25 Gbit/s pro Kanal realisieren. Große Gesamtbandbreiten kann man mit Wellenlängenmultiplex‐ (WDM, wavelength division multiplex) oder Raummultiplex‐ (SDM, spatial division multiplex) Architekturen erreichen.
Rauscharme CCD‐Kameras für Bildgebung und Spektroskopie
Authors: Regehly Martin 
Published: October 2014

AbstractFür die Aufnahme von Bildern oder Spektren erzielen auf CCD‐Sensoren basierende Kameras derzeit die höchste Empfindlichkeit und Dynamik. Rauscharme CCD‐Kameras sind nicht nur für Messungen schwacher Photonenflüsse im sichtbaren und infraroten Spektralbereich geeignet sondern auch für höhere Photonenenergien im ultravioletten (UV) und Röntgenbereich (Abb. 1). Sie werden daher als Detektoren in Wissenschaft und Industrie vielfältig eingesetzt. Im Folgenden werden ausgehend von der Funktionsweise von CCD‐Sensoren, die an der Messung beteiligten, wesentlichen Rauschprozesse vorgestellt und der Einfluss auf das Signal‐Rauschverhältnis diskutiert. Aus den Kenndaten der Kamera und der Abschätzung über die einfallende Strahlung kann das maximale SNR des CCD‐Detektors bei gegebener Messzeit abgeschätzt werden.
Was tun, wenn es rauscht?
Authors: Holst Gerhard 
Published: October 2014

AbstractEs gilt bei Fotos und Videoaufnahmen als unerwünscht, dabei ist es nicht nur ein vermeidbares Übel, sondern ergibt sich aus der Natur des Lichts: Bildrauschen. Durch die Wahl der richtigen Kamera für die jeweilige Anwendung lassen sich die Bildstörungen unter Kontrolle bringen. Es kommt dabei nicht auf den Rauschpegel allein an, sondern auf das gewünschte Signal‐Rausch‐Verhältnis der Kamera und die Aufnahmesituation.
Immer das gleiche Licht
Authors: Jensen Kevin , Damer Diane 
Published: October 2014

AbstractIm April diesen Jahres hatte Schott angekündigt, in Zusammenarbeit mit der Lufthansa eine Technik für die nächste Generation des Flugzeugkabinenlichts mittels RGBW‐LEDs (Rot, Grün, Blau, Weiß) zu entwickeln. Die Jencolor‐Farbsensoren von Mazet kommen dabei zum Einsatz, um die Einheitlichkeit des Farblichts über mehrere Module hinweg zu garantieren. Die Technologie wurde erstmals von Schott und Lufthansa auf der Aircraft Interiors Expo in Hamburg im April 2014 präsentiert. HelioJet Spectrum ist die Weiterentwicklung des frühen Prototypen, der während des LED Professional Symposiums im vergangenen Herbst enthüllt wurde.
Effects of MgH2/Mg(BH4)2 Powders on the Thermal Decomposition Behaviors of 2,4,6‐Trinitrotoluene (TNT)
Authors: Yao Miao , Chen Liping , Peng Jinhua 
Published: October 2014

AbstractThe thermal properties of 2,4,6‐trinitrotoluene (TNT), TNT/MgH2, and TNT/Mg(BH4)2 were investigated by differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC). The results show that addition of MgH2 or Mg(BH4)2 to TNT has a great effect on the DSC decomposition process. The exothermic decomposition peak of TNT disappeared and was replaced by a slow exothermic trend in the curves of both TNT/MgH2 and TNT/Mg(BH4)2. The kinetic triplet of TNT formulations were calculated by ARC data. The results show that TNT/MgH2 and TNT/Mg(BH4)2 have lower onset temperatures, apparent activation energies (E) and frequency factors (A) than neat TNT. A change of the TNT decomposition mechanism is also discussed.
Kinetics of Nano Titanium Dioxide Catalyzed Thermal Decomposition of Ammonium Nitrate and Ammonium Nitrate‐Based Composite Solid Propellant
Authors: Vargeese Anuj A. , Muralidharan Krishnamurthi , Krishnamurthy V. N. 
Published: October 2014

AbstractThis study deals with the influence of nanosized titanium dioxide (TiO2) catalysts on the decomposition kinetics of ammonium nitrate (AN) and ammonium nitrate‐based composite solid propellant. TiO2 nanocatalyst with an average particle size of 10 nm was synthesized by sol‐gel method using titanium alkoxide as precursor. Formation of nanostructured TiO2 and presence of its anatase and brookite phases was confirmed by powder X‐ray diffraction (PXRD) and selected area diffraction (SAED) studies. Nano TiO2 was further characterized by transmission electron microscopy (TEM), infrared (IR) spectroscopy, and thermogravimetry. The catalytic effect of TiO2 nanocatalysts on the solid state thermal decomposition reaction of AN and nonaluminized HTPB/AN propellant was evaluated. To ascertain the effectiveness of the TiO2 nanocatalyst, the thermal kinetic constants for the catalytic and non‐catalytic decomposition of AN and AN propellant samples were computed by using a nonlinear integral isoconversional method. Catalytic influence was evident from the lowering of activation energy for the catalyzed decomposition reactions. Apparently, the nanocatalysts provide Lewis acid and/or active metal sites, facilitating the removal of AN dissociation products NH3 and HNO3 and thereby enhance the rate of decomposition. The changes in the critical temperature of thermal explosion of AN and AN propellant samples due to the addition of TiO2 nanocatalyst were also computed and the possible reasons for the changes are discussed.
On static output‐feedback stabilization for multi‐input multi‐output positive systems
Authors: Shen Jun , Lam James 
Published: October 2014

SummaryThis paper revisits the static output‐feedback stabilization problem for positive systems. We first point out that for a class of positive systems whose output matrix has a particular row echelon form, this problem can be completely solved via linear programming. By duality, the result is also valid when the column echelon form of the input matrix has a particular structure. Along this line, by augmenting the output matrix as well as the feedback gain matrix, an iterative convex optimization algorithm is developed for the more general case. Finally, we show that the proposed method has advantages over existing works via several numerical examples. Copyright © 2014 John Wiley & Sons, Ltd.
Versatile carboxymethyl chitin and chitosan nanomaterials: a review
Authors: Narayanan Deepa , Jayakumar R. , Chennazhi K. P. 
Published: October 2014

Biocompatibility, biodegradability, and low cost of chitin and chitosan have drawn immense attention in many fields including medicine, bioinspired material science, pharmaceuticals, and agriculture. Their handling and processing are difficult owing to its insolubility in neutral aqueous solution or organic solvents. One of the methods used to improve the solubility characteristics of chitin and chitosan is chemical modification. Introducing a carboxymethyl group is the most advantageous method of increasing the solubility of chitosan at neutral and alkalinepH. Carboxymethyl chitin (CMC) and carboxymethyl chitosan (CMCS) are water soluble derivatives formed by introducingCH2COOHfunction into the polymer which endows it with better biological properties. The functional group makesCMC/CMCSnanoparticles (NPs) efficient vehicles for the delivery ofDNA, proteins, and drugs. This review provides an overview of the characteristics ofCMC/CMCS NPsas well as fulfills the task of describing and discussing its important roles primarily in cancer nanomedicine detailing the targeted drug delivery aspect. The application of these NPs in imaging, agriculture, and textiles has also been highlighted. The review also elaborates the advantages of using theCMCandCMCS NPsfor drug and gene delivery.WIREs Nanomed Nanobiotechnol2014, 6:574–598. doi: 10.1002/wnan.1301This article is categorized under:Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic DiseaseTherapeutic Approaches and Drug Discovery > Nanomedicine for Infectious DiseaseImplantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement
Recent advances in biosynthesis of fatty acids derived products in Saccharomyces cerevisiae via enhanced supply of precursor metabolites
Authors: Lian Jiazhang , Zhao Huimin 
Published: October 2014

Abstract
Fatty acids or their activated forms, fatty acyl-CoAs and fatty acyl-ACPs, are important precursors to synthesize a wide variety of fuels and chemicals, including but not limited to free fatty acids (FFAs), fatty alcohols (FALs), fatty acid ethyl esters (FAEEs), and alkanes. However, Saccharomyces cerevisiae, an important cell factory, does not naturally accumulate fatty acids in large quantities. Therefore, metabolic engineering strategies were carried out to increase the glycolytic fluxes to fatty acid biosynthesis in yeast, specifically to enhance the supply of precursors, eliminate competing pathways, and bypass the host regulatory network. This review will focus on the genetic manipulation of both structural and regulatory genes in each step for fatty acids overproduction in S. cerevisiae, including from sugar to acetyl-CoA, from acetyl-CoA to malonyl-CoA, and from malonyl-CoA to fatty acyl-CoAs. The downstream pathways for the conversion of fatty acyl-CoAs to the desired products will also be discussed.
Theory and Modeling for the Magnetospheric Multiscale Mission
Authors: Hesse M. , Aunai N. , Birn J. , Cassak P. , Denton R. E. , Drake J. F. , Gombosi T. , Hoshino M. , Matthaeus W. , Sibeck D. , Zenitani S. 
Published: October 2014

AbstractThe Magnetospheric Multiscale (MMS) mission will provide measurement capabilities, which will exceed those of earlier and even contemporary missions by orders of magnitude. MMS will, for the first time, be able to measure directly and with sufficient resolution key features of the magnetic reconnection process, down to the critical electron scales, which need to be resolved to understand how reconnection works. Owing to the complexity and extremely high spatial resolution required, no prior measurements exist, which could be employed to guide the definition of measurement requirements, and consequently set essential parameters for mission planning and execution. Insight into expected details of the reconnection process could hence only been obtained from theory and modern kinetic modeling. This situation was recognized early on by MMS leadership, which supported the formation of a fully integrated Theory and Modeling Team (TMT). The TMT participated in all aspects of mission planning, from the proposal stage to individual aspects of instrument performance characteristics. It provided and continues to provide to the mission the latest insights regarding the kinetic physics of magnetic reconnection, as well as associated particle acceleration and turbulence, assuring that, to the best of modern knowledge, the mission is prepared to resolve the inner workings of the magnetic reconnection process. The present paper provides a summary of key recent results or reconnection research by TMT members.
Examining negative effects of early life experiences on reproductive and sexual health among female sex workers in Tijuana, Mexico
Authors: Oza Karishma K. , Silverman Jay G. , Bojorquez Ietza , Strathdee Steffanie A. , Goldenberg Shira M. 
Published: October 2014

AbstractObjectiveTo explore experiences during childhood and adolescence that influenced reproductive and sexual health among women who had entered the sex industry in adolescence.MethodsA qualitative study was conducted using information provided by 25 female sex workers (FSWs) from Tijuana, Mexico, who reported entering the sex industry when younger than 18 years. In‐depth, semi‐structured interviews were conducted with all participants between January 31, 2011, and July 8, 2011.ResultsFour interrelated themes that shaped health experiences—early sexual abuse, early illicit drug use, ongoing violence, and limited access to reproductive and sexual health care—were identified. Participants reporting these experiences were at risk of unintended teenaged pregnancy, spontaneous abortion or stillbirth, and untreated sexually transmitted infections.ConclusionPrograms and policies that address social, structural, and individual vulnerabilities during adolescence and adulthood are required to promote reproductive and sexual health among FSWs in Tijuana, Mexico.
Market conditions, governance and the information content of insider trades
Authors: Bhabra Harjeet S. , Hossain Ashrafee T. 
Published: October 2014

AbstractWe examine the information content of Form‐4 filings following extreme market downturns in the pre and post‐Sarbanes–Oxley‐Act (SOX) periods. We find that the announcement period abnormal returns under extreme market conditions are larger and this effect is stronger in the more tighter disclosure rules in the post‐SOX period. Insider rank, corporate governance and proxies for information asymmetry are significantly related to the abnormal returns around the filing date. Overall, our results show that the more timely filing requirement introduced by SOX has been particularly beneficial for investors in firms with higher levels of information asymmetry, poor governance and during market downturns.
Vortex stretching and compression near the turbulent/non-turbulent interface in a planar jet
Authors: Watanabe Tomoaki , Sakai Yasuhiko , Nagata Kouji , Ito Yasumasa , Hayase Toshiyuki 
Published: October 2014

AbstractVortex stretching and compression, which cause enstrophy production by inviscid processes, are investigated near the turbulent/non-turbulent (T/NT) interface in a planar jet by using a direct numerical simulation (DNS). The enstrophy production is investigated by analysing the relationship among a vorticity vector, strain-rate eigenvectors and strain-rate eigenvalues. The statistics are calculated individually for three different interface orientations. The vorticity near the T/NT interface is oriented in the tangential direction to the interface. The enstrophy production is affected by the interface orientation because the intensity of vortex stretching depends on the interface orientation, and the alignment between the vorticity vector and the strain-rate eigenvectors is confined by the interface. The enstrophy production near the T/NT interface is analysed by considering the motion of turbulent fluid relative to that of the interface. The results show that the alignment between the interface and the strain-rate eigenvectors changes depending on the velocity field near the T/NT interface. When the turbulent fluid moves toward the T/NT interface, the enstrophy is generated by vortex stretching without being greatly affected by vortex compression. In contrast, when the turbulent fluid relatively moves away from the T/NT interface, large enstrophy reduction frequently occurs by vortex compression. Thus, it is shown that the velocity field near the T/NT interface affects the enstrophy production near the interface through the alignment between the vorticity and the strain-rate eigenvectors.