bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Simple Cycloalkylsilanetriols as Surface Modifier for Inorganic Particles
Authors: Yoo Bok Ryul , Jung Dong Euy , Han Joon Soo 
Published: June 2009

AbstractSimple cycloalkylsilanetriols RSi(OH)3 [R =c- pentyl (1</b>) and c-hexenyl (2b</b>)] were synthesized as white powders in 70% and 90% isolated yields, respectively, from the hydrolysis of the corresponding trialkoxysilanes with mild acidic water. Silanetriols 1</b>,2</b> are soluble in water and polar organic solvents such as alcohol, acetone, THF, DMSO, and etc. They can be applied as surface modifiers for inorganic materials such as silica and titania through simple two step processes: 1) organosilanetriol interact with hydroxyl groups on inorganic materials through hydrogen bonding to make molecular layered thin coating on the inorganic surface, 2) then can undergo condensation by heating about 110 ℃ above to form M-O-Si covalent bond to give hydrophobic silica. With the treatment of ca. 50 nm spherical silica with 5 wt % alkylsilaneol 1, no precipitation of silica particles in water was observed, indicating good surface modifiers for silica particle. In this presentation we will discuss the application of silanetriols as surface modifier for inorganic materials such as silica and titania particles.
Experimental Evidence of the Hyperfine Interaction between Hole and Nuclear Spins in InAs/GaAs Quantum Dots
Authors: Eble Benoit , Testelin Christophe , Desfonds Pascal , Bernardot Frederic , Balocchi Andrea , Amand Thierry , Miard Anne , Lemaître Aristide , Marie Xavier , Chamarro Maria 
Published: June 2009

AbstractThe spin dynamics of resident holes in singly p-doped InAs/GaAs quantum dots is studied by pump-probe photo-induced circular dichroism experiments. We show that the hole spin dephasing is controlled by the hyperfine interaction between the hole spin and nuclear spins. We find a characteristic hole spin dephasing time of 12 ns, in close agreement with our calculations based on a dipole-dipole coupling between the hole and the quantum dot nuclei. Finally we demonstrate that a small external magnetic field, typically 10 mT, quenches the hyperfine hole spin dephasing.
Topological Interlocking in Design of Structures and Materials
Authors: Estrin Yuri , Dyskin Arcady , Pasternak Elena , Schaare Stephan 
Published: June 2009

AbstractSince its introduction in 2001 [1], the concept of topological interlocking has advanced to reasonable maturity, and various research groups have now adopted it as a promising avenue for developing novel structures and materials with unusual mechanical properties. In this paper, we review the known geometries of building blocks and their arrangements that permit topological interlocking. Their properties relating to stiffness, fracture resistance and damping are discussed on the basis of experimental evidence and modeling results. An outlook to prospective engineering applications is also given.
Next Generation Phase Change Materials as Multifunctional Watery Suspension for Heat Transport and Heat Storage
Authors: Hadjieva Milka Markova , Bozukov Metodi , Gutzov Ivan 
Published: June 2009

AbstractThe phase change materials (PCM) are known since years with high thermal storage capacity but with limited applications. The modified PCM mainly paraffin watery suspensions, so called PCM slurry, improve some PCM drawbacks (thermal conductivity) and as paraffin multifunctional fluids can work in both, heat transport and heat storage for cooling technology applications. The structural and thermophysical properties of two types PCM slurry were good basis for comparison of their efficiency: paraffin microcapsule slurry (A) and paraffin emulsion slurry (B), both working in temperature range of phase transition from 2-12 degreesC. The equipments as differential scanning calorimetry (DSC), model NETZSCH DSC 200 PC; scanning electron microscopy (SEM), JOEL model JSM-5510; hot stage optical microscopy, LINKAM model TMS 94 and hand made thermal cycling system operational with Danfoss cooling machine that ensured 2 kW cooling capacity at 40oC; gave accurate results, characterizing completely, from structural and thermal point of view both types of PCM multifunctional structured fluids. Structural stability of the advanced phase change multifunctional fluids was discussed on sample imaging in variable magnifications made by method of Hot Stage microscopy and precise SEM study. Systematization of the DSC results obtained, including temperature range of phase transition and thermal storage capacity, measured before and after repeatable thermal cycling of the PCM multifunctional fluids, allowed selection of the PCM slurry working samples with relatively high thermal capacity applicable to further development in prototypes. Heat absorbed/released, calculated by NETZSCH DSC software, was for PCM slurry A in the range of 80 to 82 kJ/kg, while PCM slurry B showed thermal storage capacity from 56 to 53 kJ/kg. Correlation between the structural properties and thermal storage capacity of the phase change multifunctional fluids led to practical conclusions concerning: homogeneity; crystal growth/conditions; structural compatibility between components; prediction of the heat flow behavior of multifunctional PCM slurries in cooling technology for storage and transport of heat.
Remobilization of Polychlorinated Biphenyl from Baltic Sea Sediment: Comparing the Roles of Bioturbation and Physical Resuspension
Authors: Hedman Jenny E. , Tocca Julia Stempa , Gunnarsson Jonas S. 
Published: June 2009

Abstract
The release of a 14C-labeled trichlorobiphenyl compound ([14C]PCB 32) from sediment to water was quantified weekly in a 30-d microcosm experiment with recirculating water. Two modes of bioturbation-driven polychlorinated biphenyl (PCB) release—bioturbation by the amphipod Monoporeia affinis (a particle biodiffuser) and bioturbation by the polychaete Marenzelleria sp. (a bioirrigator)—were compared to the PCB release caused by physical resuspension of the sediment generated by a motor-driven paddle used twice a week. Bioturbation by the amphipod M. affinis caused a significantly higher remobilization of both particle-associated PCB (PCBpart) and dissolved PCB (PCBdiss) than the other treatments. Bioturbation by Marenzelleria sp. and physical resuspension caused a similar release of PCBdiss despite a significantly higher amount of total suspended solids in the water column after physical resuspension. In all treatments, the release of PCBdiss was more than one order of magnitude higher than that of PCBpart, indicating a significant potential route of exposure for pelagic organisms, such as fish, to the most bioavailable PCB form. Calculated mass-transfer coefficients (0.3–1.3 cm/d) correspond to previously reported values for trichlorinated PCBs. The present results indicate that biological reworking of sediments can be just as, or even more, important than physical resuspension for the remobilization of sediment-bound contaminants.
Minimally invasive plate osteosynthesis: Applications and techniques in dogs and cats
Authors: Hudson C.C. , Lewis D.D. , Pozzi A. 
Published: June 2009

SummaryBone plating has been used as a method of fracture management for many years. Recently, a trend toward the use of fracture fixation techniques which preserve the local fracture environment, known as biological osteosynthesis, has evolved. This trend has resulted in the development of a less traumatic method of bone plating referred to as minimally invasive plate osteosynthesis (MIPO), or percutaneous plating. During MIPO fracture stabilisation, plates are inserted through short incisions and a communicating epiperiosteal tunnel. Typically, bone plates applied in this fashion have a bridging function. Promising outcomes have been reported in human patients undergoing MIPO fracture stabilisation, and limited reports of the use of this technique in dogs and cats have yielded positive results as well. Careful case selection, pre-operative planning, and appropriate instrumentation are necessary when performing the technique. Rapid time to union, low complication rates and good return to function have been noted in human patients. Additional research is needed to define selection criteria and outline the definitive benefits of MIPO in dogs and cats.
Germanium(II) Dications Stabilized by Azamacrocycles and Crown Ethers
Authors: Cheng Fei , Hector Andrew L. , Levason William , Reid Gillian , Webster Michael , Zhang Wenjian 
Published: June 2009

AbstractEine Krone für Germanium: Neutrale Aza‐ und Oxamakrocyclen stabilisieren halogenfreie Germanium(II)‐Dikationen (siehe Bild: Ge türkis, N blau, C grau). Die resultierenden Strukturen hängen stark von der Zahl und Art der Donoratome und von der Größe des Makrocyclus ab.magnified image
[Al4(OH)2(OCH3)4(H2N‐bdc)3]⋅x H2O: A 12‐Connected Porous Metal–Organic Framework with an Unprecedented Aluminum‐Containing Brick
Authors: Ahnfeldt Tim , Guillou Nathalie , Gunzelmann Daniel , Margiolaki Irene , Loiseau Thierry , Férey Gérard , Senker Jürgen , Stock Norbert 
Published: June 2009

AbstractAl together now! A new stable aluminum aminoterephthalate system contains octameric building blocks that are connected by organic linkers to form a 12‐connected net (see picture). The structure adopts a cubic centered packing motive in which octameric units replace individual atoms, thus forming distorted octahedral (red sphere) and tetrahedral cages (green spheres) with effective accessible diameters of 1 and 0.45 nm, respectively.magnified image
Distributed leader‐follower flocking control
Authors: Wang Zongyao , Gu Dongbing 
Published: June 2009

AbstractThis paper presents a fuzzy based leader‐follower flocking system. To maintain the distance between robots, we use a fuzzy logic controller to design a “force function” which is related to the relative distance between neighbours. The “force function” is used to control velocity of robots. To prove stability of the flocking system, we build a Hamilton function which is kinetic energy of the flocking system. Utilizing the LaSalle's invariance principle, we prove that the system is stable. Specially, we develop a flocking controller in local form. By using the local controller, the robots in the flocking system only need to know local information (relative distances and relative angles between neighbours). To evaluate performance of the flocking system, we simulate the flocking system tracking trajectories with different shapes. The local flocking algorithm is tested with three Pioneer robots. We use the SICK laser scanner to measure the relative distances and relative angles between neighbours. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Design of nonlinear H∞ controllers using describing functions with application to servomechanism
Authors: Nassirharand Amir , Firdeh S. R. Mousavai 
Published: June 2009

AbstractA systematic procedure for design of nonlinear H∞ controllers for amplitude‐dependent nonlinear plants is presented. The procedure is based on describing function concepts involving sinusoidal input describing function models of the nonlinear plant followed by application of an inverse describing function technique to arrive at nonlinear gains of the H∞ controller. The procedure is applied to a servomechanism problem to demonstrate the typical results that may be achieved. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Output feedback stabilization for delayed large‐scale stochastic systems with markovian jumping parameters
Authors: Zhang Baoyong , Xu Shengyuan , Zou Yun 
Published: June 2009

AbstractThis paper deals with the problem of decentralized output feedback stabilization for a class of large‐scale stochastic time‐delay systems with Markovian jumping parameters. Attention is focused on the design of a decentralized dynamic output feedback controller, which is also with Markovian jumping parameters, such that the closed‐loop system is exponentially mean‐square stable. A sufficient condition for the solvability of this problem is proposed in terms of linear matrix inequalities. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Does identification predict community involvement? Exploring consequences of social identification among the Jewish minority in Poland
Authors: Bilewicz Michał , Wójcik Adrian 
Published: June 2009

AbstractPrevious research indicated that people who strongly identify with their own group are more involved in the group's actions. The current study examines the relation between three dimensions of group identification (affect, ties, centrality) and forms of community involvement among members of the Jewish minority in Poland. The strength of ingroup ties predicted involvement in the ethnic minority community. The link between identification and involvement was mediated by the cultural dominance. The reported study was the first quantitative survey of the Jewish community in post‐War Poland. Copyright © 2009 John Wiley & Sons, Ltd.
Polyamine Receptors Containing Dipyridine or Phenanthroline Units: Clues for the Design of Fluorescent Chemosensors for Metal Ions
Authors: Bazzicalupi Carla , Bencini Andrea , Biagini Silvia , Bianchi Antonio , Faggi Enrico , Giorgi Claudia , Marchetta Melania , Totti Federico , Valtancoli Barbara 
Published: June 2009

AbstractThe synthesis of the macrocyclic receptor L1, which contains a tetraamine chain linking the 6,6′‐positions of a 2,2′‐dipyridine moiety, is reported. Its basicity properties and complexation features toward CuII, ZnII, CdII and PbII have been studied in aqueous solutions by means of potentiometric, UV/Vis spectroscopy and fluorescence emission measurements and compared with those of ligand L2, in which a 1,10‐phenanthroline moiety replaces the dipyridine unit of L1. In metal coordination, L1 shows a marked selectivity toward CdII over ZnII and PbII. The crystal structures of its metal complexes shows that L1 possesses a preferential tetradentate binding site for metal cations, composed of the dipyridine unit and the two adjacent benzylic amine groups. This binding site has the proper dimension and conformation to selectively coordinate the CdII ion, as confirmed by DFT calculations carried out on the complexes. This coordinative zone is lost in L2. The rigidity of phenanthroline does not allow the simultaneous binding of both the benzylic amine groups to ZnII and CdII and, in fact, one benzylic amine is not coordinated to these metal cations. The fluorescence emission properties of the L1 and L2 complexes are strongly pH dependent. Only the ZnII and CdII complexes with L1 display fluorescence emission at neutral pH. This feature is related to the formation in solution at pH 7 of emissive protonated complexes of the type [M(HxL)](2+x)+ (x=1–3), in which all the nitrogen donors are involved in metal or proton binding. The emissive characteristics of these protonated complexes are confirmed by the fluorescence emission spectra collected on the [Zn(HL1)Br][ClO4]2 and [Cd(HL1)Br][ClO4]2 solid compounds dissolved in CH3CN. Conversely, the ZnII and CdII complexes with L2 are not emissive; in fact, they contain a benzylic amine group not involved in metal or proton binding that can quench the fluorescence emission of the fluorophore, thanks to a photoinduced electron‐transfer process.
Highly Enantioselective Epoxidation of cis‐Alkenylsilanes
Authors: Matsumoto Kazuhiro , Kubo Takuya , Katsuki Tsutomu 
Published: June 2009

AbstractA general and highly enantioselective method for the epoxidation of cis‐alkenylsilanes, in which the epoxysilanes were obtained with complete enantioselectivity in the presence of 0.5–2 mol % of a Ti–Salalen complex. The combination of this epoxidation method and the following transformations is a powerful approach that provides synthetically important epoxides, such as styrene oxides and geminally disubstituted epoxides, in enantiopure form.magnified image
Mit Stradivari, Kunstsaiten und Kolophonium. Das chemische Geheimnis der Geigenvirtuosen
Authors: Roth Klaus 
Published: June 2009

AbstractAuf der Suche nach “Stradivaris Geheimnis” haben unzählige akustische und chemische Untersuchungen, einschließlich Analysen der Grundierung, des Lacks und der Pigmente, unser Verständnis von der Herstellung und dem Spiel einer Geige vertieft. Blindtests mit Violin‐Experten haben einige Zweifel an der Überlegenheit von Stradivari Violinen aufkommen lassen, so dass vielleicht gar kein Geheimnis existiert. Ein chemische Tatsache ist aber sicher: Geigen entfalten ihren Wohlklang nur nach Einreiben der Bogenhaare mit Kolophonium, einer Mischung verschiedener tricyclischer Diterpene, die über eine protonen‐katalysierte Umlagerung umgelagert worden sind. Dies beweist wieder einmal, die Chemie lässt wirkliche Wunder wahr werden.
Neue intermetallische Supraleitung
Authors: Feil Sylvia 
Published: June 2009

AbstractAls neue Werkstoffe werden die Materialeigenschaften intermetallischer Eisen‐Arsenid‐Supraleiter untersucht, die ähnlich den bisher bekannten Cupraten zu den Hochtemperatursupraleitern zählen. Wie in den keramischen Cupraten ist auch in den neuen intermetallischen Supraleitern die leitende Schicht zweidimensional. Indem ein elektronisches Phasendiagramm der Leitfähigkeit erstellt wurde, können die Theorien zur Entstehung von Supraleitern überprüft und revidiert werden. Zugleich wurden die Ordnungs‐Parameter der auf Eisen basierenden Supraleiter LaO1–xFxFeAs für Dotierungen von x von Null bis 0,2 erfasst.
Freiberg in Sachsen
Authors: Schwedt Georg 
Published: June 2009

AbstractDie Gesellschaft Deutscher Chemiker (GDCh) erinnert durch Gedenktafeln und die Herausgabe einer Broschüre an die Wirkungsstätten bedeutender Chemiker und an die Forschung der Wissenschaftler. Auf diese Weise werden einer breiteren Öffentlichkeit historische Wurzeln und das kulturelle Erbe der Chemie bekannt gemacht.
Identification of vasculature‐specific genes by microarray analysis of etsrp/etv2 overexpressing zebrafish embryos
Authors: Wong Kuan Shen , Proulx Kira , Rost Megan S. , Sumanas Saulius 
Published: June 2009

AbstractSignaling pathways controlling vasculogenesis, angiogenesis, and myelopoiesis are still poorly understood, in part because not all genes important for vasculature or myeloid cell formation have been characterized. To identify novel potential regulators of vasculature and myeloid cell formation we performed microarray analysis of zebrafish embryos that overexpress Ets1‐related protein (Etsrp/Etv2/ER71), sufficient to induce vasculogenesis and myelopoiesis (Sumanas and Lin [2006] Development 121:3141–3150; Lee [2008] Cell Stem Cell 2:497–507; Sumanas et al. [2008] Blood 111:4500–4510). We performed sequence homology and expression analysis for up‐regulated genes that were novel or previously unassociated with the zebrafish vasculature formation. Angiotensin II type 2 receptor (agtr2), src homology 2 domain containing E (she), mannose receptor C1 (mrc1), endothelial cell‐specific adhesion molecule (esam), yes‐related kinase (yrk/fyn), zinc finger protein, multitype 2b (zfpm2b/fog2b), and stabilin 2 (stab2) were specifically expressed in vascular endothelial cells during early development while keratin18 expression was localized to the myeloid cells. Identification of vasculature and myeloid‐specific genes will be important for dissecting molecular mechanisms of vasculogenesis/angiogenesis and myelopoiesis. Developmental Dynamics 238:1836–1850, 2009. © 2009 Wiley‐Liss, Inc.
Theoretical Study of the RNA Hydrolysis Mechanism of the Dinuclear Zinc Enzyme RNase Z
Authors: Liao Rong‐Zhen , Himo Fahmi , Yu Jian‐Guo , Liu Ruo‐Zhuang 
Published: June 2009

AbstractRNase Z is a dinuclear zinc enzyme that catalyzes the removal of the tRNA 3′‐end trailer. Density functional theory is used to investigate the phosphodiester hydrolysis mechanism of this enzyme with a model of the active site constructed on the basis of the crystal structure. The calculations imply that the reaction proceeds through two steps. The first step is a nucleophilic attack by a bridging hydroxide coupled with protonation of the leaving group by a Glu‐His diad. Subsequently, a water molecule activated by the same Glu‐His diad makes a reverse attack, regenerating the bridging hydroxide. The second step is calculated to be the rate‐limiting step with a barrier of 18 kcal/mol, in good agreement with experimental kinetic studies. Both zinc ions participate in substrate binding and orientation, facilitating nucleophilic attack. In addition, they act as electrophilic catalysts to stabilize the pentacoordinate trigonal‐bipyramidal transition states.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Syntheses, Crystal Structures and Photophysical Properties of Two Doubly μ‐Phenoxo‐Bridged LnIII (Ln = Pr, Nd) Homodinuclear Schiff Base Complexes
Authors: Chakraborty Joy , Thakurta Santarupa , Pilet Guillaume , Ziessel Raymond F. , Charbonnière Loïc J. , Mitra Samiran 
Published: June 2009

AbstractTwo novel homodinuclear isomorphous lanthanide(III) complexes [Ln(api)]2 (where Ln = Pr and Nd for 1 and 2, respectively) with Schiff base anion api3– {H3api = 2‐(2‐hydroxyphenyl)‐1,3‐bis[4‐(2‐hydroxyphenyl)‐3‐azabut‐3‐enyl]‐1,3‐imidazolidine} have been synthesized by a direct reaction of the Schiff base ligand and the corresponding hydrated lanthanide(III) nitrates in methanol. The geometry of each LnIII ion in both complexes is distorted square antiprism (DSAP) as revealed by single‐crystal X‐ray diffraction studies and the structures are found to be centrosymmetric. Both the complexes along with the ligand have been characterized by microanalysis and different spectroscopic techniques. A detailed photophysical investigation has been performed on both the ligand and the complexes. The fluorescence lifetime for the ligand is in the nanosecond regime, suggesting emission from a singlet state. The two lanthanide complexes exhibit NIR luminescence which has been explored throughsolid‐state photoluminescence. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Characterisation and Modelling of a High Temperature PEM Fuel Cell Stack using Electrochemical Impedance Spectroscopy
Authors: Andreasen S. J. , Jespersen J. L. , Schaltz E. , Kær S. K. 
Published: June 2009

AbstractIn designing and controlling fuel cell systems, it is advantageous to have models which predict fuel cell behaviour in steady‐state as well as in dynamic operation. This work examines the use of electro‐chemical impedance spectroscopy (EIS) for characterising and developing an impedance model for a high temperature PEM (HT‐PEM) fuel cell stack. A Labview virtual instrument has been developed to perform the signal generation and data acquisition which is needed to perform EIS. The typical output of an EIS measurement on a fuel cell is a Nyquist plot, which shows the imaginary and real parts of the impedance of the measured system. The full stack impedance depends on the impedance of each of the single cells of the stack. Equivalent circuit models for each single cell can be used to predict the stack impedance at different temperature profiles of the stack. The information available in such models can be used to predict the fuel cell stack performance, e.g. in systems where different electronic components introduce current harmonics.