bluuebunny/crossref_metadata_2025 huggingface dataset:
Enantioseparation of doubly functionalized polar norbornenes by HPLC and their ruthenium‐catalyzed ring‐opening metathesis polymerization
Authors: Nishihara Yasushi , Doi Yukiko , Izawa Seisuke , Li Horng‐Yi , Inoue Yoshiaki , Kojima Masaaki , Chen Jwu‐Ting , Takagi Kentaro
Published: December 2009

Doubly fuctionalized polar norbornenes bearing the cyano and ester groups in 2,3‐positions are synthesized and enantiomers are separated by high performance liquid chromatography (HPLC) with a chiral stationary phase. These optically active monomers are polymerized by ruthenium carbene catalysts, and high yields of the polymers were obtained. The chiral monomer bearing ethyl ester gave an optically active polymer of lower, but opposite sign of optical rotation (monomer [α]D = +61.0°, polymer [α]D = −3.1°). The circular dichroism (CD) of the obtained chiral polymers gave a Cotton effect. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 485–491, 2010
Conjugated copolymers comprised cyanophenyl‐substituted spirobifluorene and tricarbazole‐triphenylamine repeat units for blue‐light‐emitting diodes
Authors: Lin Ying , Chen Zhi‐Kuan , Ye Teng‐Ling , Dai Yan‐Feng , Ma Dong‐Ge , Ma Zhun , Liu Qin‐De , Chen Yu
Published: December 2009

A series of conjugated blue‐light‐emitting copolymers, PTC‐1, PTC‐2, and PTC‐3, comprised different ratios of electron‐withdrawing segments (spirobifluorene substituted with cyanophenyl groups) and electron‐donating segments (tricarbazole‐triphenylamines), has been synthesized. The structures of these polymers were characterized and their thermal, photophysical, electrochemical, and electroluminescence properties were measured. Incorporation of rigid spirobifluorene units into the copolymers led to blue‐shifted absorption peaks in dilute toluene solution. Cyclic voltammetric measurement indicated the bandgaps of the polymers were in the range of 2.77–2.94 eV. It was found that increasing cyanophenyl‐spirobifluorene content in the polymer backbone lowered both the HOMO and LUMO energy levels of the copolymers, which was beneficial for electron injection/transporting in the polymer layer of the device. OLED device evaluation indicated that all the polymers emitted sky blue to deep blue light when the pure polymers were used as the emissive layers in the devices with a configuration of ITO/PEDOT:PSS/polymers/CsF/Ca/Al. The devices have been optimized by doping 30 wt % PBD into the polymer layers. Among the doped devices, PTC‐2 showed the best performance with the turn‐on voltage of 3.0 V, maximum brightness of 7257 cd/m2, maximum current efficiency of 1.76 cd/A, and CIE coordinates of (0.15, 0.14). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 292–301, 2010
Multistimuli responsive amphiphilic graft poly(ether amine): Synthesis, characterization, and self‐assembly in aqueous solution
Authors: Ren Yanrong , Jiang Xuesong , Yin Guilin , Yin Jie
Published: December 2009

We reported that multiresponsive amphiphilic graft poly(ether amine)s (agPEAs) comprised of hydrophilic poly(ethylene oxide) (PEO) and hydrophobic octadecyl alkyl chain as side‐chain were prepared through one‐pot synthesis. In aqueous solution, these obtained agPEAs can self‐assemble into stable nanomicelles, whose aggregation can be controlled by temperature, pH, and ionic strength with tunable cloud point (CP). In the presence of these obtained agPEAs, hydrophobic dye Nile red can be dispersed into aqueous solution and hydrophilic dye methyl orange can be dispersed into nonpolar toluene. The agPEAs are expected to be potential in application such as encapsulation and controlled release of drugs, due to their simple synthesis, amphiphilicity, and multistimuli response. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 327–335, 2010
Effects of external donors and hydrogen concentration on oligomer formation and chain end distribution in propylene polymerization with Ziegler‐Natta catalysts
Authors: Vestberg Torvald , Denifl Peter , Parkinson Matthew , WilÉN Carl‐Eric
Published: December 2009

The effect of type and concentration of external donor and hydrogen concentration on oligomer formation and chain end distribution were studied. Bulk polymerization of propylene was carried out with two different Ziegler‐Natta catalysts at 70 °C, one a novel self‐supported catalyst (A) and the other a conventional MgCl2‐supported catalyst (B) with triethyl aluminum as cocatalyst. The external donors used were dicyclopentyl dimethoxy silane (DCP) and cyclohexylmethyl dimethoxy silane (CHM). The oligomer amount was shown to be strongly dependent on the molecular weight of the polymer. Catalyst A gave approximately 50 % lower oligomer content than catalyst B due to narrower molecular weight distribution in case of catalyst A. More n‐Bu‐terminated chain ends were found for catalyst A indicating more frequent 2,1 insertions. Catalyst A also gave more vinylidene‐terminated oligomers, suggesting that chain transfer to monomer, responsible for the vinylidene chain ends, was a more important chain termination mechanism for this catalyst, especially at low hydrogen concentration. Low site selectivity, due to low external donor concentration or use of a weak external donor (CHM), was also found to increase formation of vinylidene‐terminated oligomers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 351–358, 2010
Alternating copolymerization of carbon dioxide and propylene oxide under bifunctional cobalt salen complexes: Role of Lewis base substituent covalent bonded on salen ligand
Authors: Liu Binyuan , Gao Yanhao , Zhao Xin , Yan Weidong , Wang Xianhong
Published: December 2009

Alternating copolymerization of propylene oxide (PO) and carbon dioxide (CO2) was realized under mild conditions with a moderate turnover frequency (TOF), employing sole bifunctional cobalt salen complexes containing Lewis acid metal center and covalent bonded Lewis base on the ligand. Variation of the covalent bonded Lewis base substituents on the salen ligands could tailor the catalytic activity with TOF changing from 19.3 to 34.9 h−1, polymeric/cyclic carbonate selectivity from 95.3 to 72.8%, and the head‐to‐tail structure in the polymer from 72.2 to 86.0%. The IR analysis confirmed that the Lewis base moiety on one molecule could coordinate with cobalt center of adjacent molecule, playing similar role to the Salen metal complex/Lewis base binary catalytic system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 359–365, 2010
Synthesis and characterization of cross‐linkable ruthenium complex dye and its application on dye‐sensitized solar cells
Authors: Liu Ken‐Yen , Hsu Chiao‐Ling , Chang Shun‐Hsing , Chen Jian‐Ging , Ho Kuo‐Chuan , Lin King‐Fu
Published: December 2009

A new crosslinkable light sensitizer, Ru(2,2′‐bipyridine‐4,4′‐bicarboxylic acid)(4,4′‐bis(11‐dodecenyl)‐2,2′‐bipyridine)(NCS)2, denoted as Ru‐C for titanium oxide nanocrystalline‐based solar cells was synthesized with its crosslinking properties invesitigated by Fourier‐transform infrared and UV‐vis absorption spectroscopies. After crosslinking by itself or copolymerizing with methyacrylic acid, their sensitized solar cells with poly(methylacrylate)‐gelled electrolyte system not only attained more than 5% of power conversion efficiency at AM 1.5 illumination (100 mW/cm2), but also gave rise to long storage life. To the best our knowledge, this is the first crosslinkable dye ever applied to the DSSC in the literature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 366–372, 2010
Thermoregulated phase‐transfer catalysis via PEG‐armed Ru(II)‐bearing microgel core star polymers: Efficient and reusable Ru(II) catalysts for aqueous transfer hydrogenation of ketones
Authors: Terashima Takaya , Ouchi Makoto , Ando Tsuyoshi , Sawamoto Mitsuo
Published: December 2009

Thermoregulated phase‐transfer catalysis for the transfer hydrogenation of 2‐octanone in 2‐propanol/H2O biphasic media was achieved with ruthenium‐bearing microgel‐core star polymers with amphiphilic, thermosensitive poly(ethylene glycol) (PEG) arms [Ru(II)‐PEG star], which were directly prepared by the ruthenium‐catalyzed living radical polymerization in conjunction with a phosphine ligand‐carrying styrene derivative. The star polymers were first placed in the aqueous (lower) layer at room temperature and immediately moved into the organic (upper) layer at 100 °C, and once again, moved down to the aqueous layer (lower) upon cooling the solution to room temperature. The Ru(II)‐PEG star catalyst was clearly superior to the original Ru(II) catalyst and related non‐microgel catalysts [Ru(II)‐PEG block] in terms of activity and recovery/recycle, due to the unique designer structure of the microgel‐core star polymers. Other substrates (less hydrophobic alkyl ketones and aromatic ketone) were also efficiently hydrogenated into the corresponding sec‐alcohols with the star catalyst in aqueous media. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 373–379, 2010
Dendronized polymers via Diels–Alder “click” reaction
Authors: Tonga Murat , Cengiz Nergiz , Kose Meliha Merve , Dede Tuna , Sanyal Amitav
Published: December 2009

A modular approach toward the synthesis of polymers containing dendron groups as side chains is developed using the Diels–Alder “click” reaction. For this purpose, a styrene‐based polymer appended with anthracene groups as reactive side chains was synthesized. First through third‐generation polyester dendrons containing furan‐protected maleimide groups at their focal point were synthesized. Facile, reagent‐free, thermal Diels–Alder cycloaddition between the anthracene‐containing polymer and latent‐reactive dendrons leads to quantitative functionalization of the polymer chains to afford dendronized polymers. The efficiency of this functionalization step was monitored using 1H and 13C NMR spectroscopy and FTIR and UV–vis spectrometry. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 410–416, 2010
Copolymerization of ethylene with 1‐hexene promoted by novel multi‐chelated non‐metallocene complexes with imine bridged imidazole ligand
Authors: Ma Lifu , Wang Hongli , Yi Jianjun , Huang Qigu , Gao Kejing , Yang Wantai
Published: December 2009

A series of novel bridged multi‐chelated non‐metallocene catalysts is synthesized by the treatment ofN,N‐imidazole,N,N‐dimethylimidazole, andN,N‐benzimidazole withn‐BuLi, 2,6‐dimethylaniline, and MCl4(M = Ti, Zr) in THF. These catalysts are used for copolymerization of ethylene with 1‐hexene after activated by methylaluminoxane (MAO). The effects of polymerization temperature, Al/M molar ratio, and pressure of monomer on ethylene copolymerization behaviors are investigated in detail. These results reveal that these catalysts are favorable for copolymerization of ethylene with 1‐hexene featured high catalytic activity and high comonomer incorporation. The copolymer is characterized by13C NMR, WAXD, GPC, and DSC. The results confirm that the obtained copolymer features broad molecular weight distribution (MWD) about 33–35 and high 1‐hexene incorporation up to 9.2 mol %, melting temperature of the copolymer depends on the content of 1‐hexene incorporation within the copolymer chain and 1‐hexene unit in the copolymer chain isolates by ethylene units. The homopolymer of ethylene has broader MWD with 42–46. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 417–424, 2010
Effect of shear on the crystallization of the poly(ether ether ketone)
Authors: Zhao Guiyan , Men Yongfeng , Wu Zhonghua , Ji Xiangling , Jiang Wei
Published: December 2009

The effect of shear on the crystallization behavior of the poly(ether ether ketone) (PEEK) has been investigated by means of ex situ wide‐angle X‐ray diffraction (WAXD), small‐angle X‐ray scattering, and differential scanning calorimetry (DSC). The changes of the intensity of WAXD patterns along shear direction of the PEEK induced by short‐term shear were observed when the samples crystallized at 330 °C. The results showed that the dimensions of the crystallites perpendicular to the (110) and (111) planes reduced with the increase of shear rate, whereas the dimensions of the crystallites perpendicular to (200) plane increased with the increase of shear rate. Moreover, increasing shear rate can lead to the increase of the crystallinity as well as the average thickness of the crystalline layers. Correspondingly, a new melting peak at higher temperature was found during the subsequent DSC scanning when the shear rate was increased to 30 s−1. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 220–225, 2010
Study of the quiescent and shear‐induced crystallization kinetics of intercalated PTT/MMT nanocomposites
Authors: Favaro Márcia M. , Rego Bruna T. , Branciforti Márcia C. , Bretas Rosario E. S.
Published: December 2009

An intercalated nanocomposite made of montmorillonite nanoclay, MMT, and poly(trimethylene terephthalate), PTT, was produced by twin screw extrusion and characterized by wide angle X‐ray diffraction, WAXD, and transmission electron microscopy, TEM. The quiescent isothermal and non‐isothermal and the flow‐induced crystallization of the nanocomposite were studied by differential scanning calorimetry, DSC, polarized light optical microscopy, PLOM, and rheometry. The quiescent results showed that the nanoclay acted as an efficient nucleating agent for the PTT, which result in an anticipation of the transition temperature between regimes II and III of crystallization. The fold interfacial free energy, σe, of the PTT in the nanocomposite during regime III was lower than in the pure state; that is, the pure PTT developed spherulites, whereas in the nanocomposite it produced a paracrystalline morphology. Under shear rate, the total times for crystallization in the nanocomposite were higher than in the pure PTT. In flow‐induced crystallization, a fibrillar nucleus must be formed as a result of chain orientation. In the nanocomposite, chain orientation only occurred after the percolated structure was broken. Therefore, the formation of a fibrillar nucleus in the nanocomposite took more time, which increased the total crystallization time. Inc. J Polym Sci Part B: Polym Phys 48: 113–127, 2010
Polymer chain of freely‐jointed segments in nematic molecular mean‐field
Authors: Walasek Janusz
Published: December 2009

The distribution function of orientations of a segment, which interacts with the orienting field and is within the chain with given the end‐to‐end distance‐vector, is calculated. The number of segments per chain is finite. The Lagrange method of conditional minimization of the chain free energy (the Helmholtz function) functional is used. Constraints for the segment orientations stem from fixed the chain end‐to‐end distance‐vector. Hence, Lagrange multipliers, energy, free energy, and entropy, for the chain with given the end‐to‐end distance‐vector, are calculated. Then, the distribution function of values of that vector is obtained. Furthermore, an average free energy per chain inside the polymer network with given a topological structure, the system self‐deformation, and modulus of elasticity are calculated and discussed in Gaussian limit, that is, for the number of segments per chain tending to infinity. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 138–144, 2010
Effects of carbon nanotubes on dynamic mechanical property, thermal property, and crystal structure of poly(L‐lactic acid)
Authors: Shieh Yeong‐Tarng , Liu Gin‐Lung , Twu Yawo‐Kuo , Wang Tzong‐Liu , Yang Chien‐Hsin
Published: December 2009

Effects of carbon nanotubes (CNT) on the dynamic mechanical property, thermal property, and crystal structure of poly(L‐lactic acid) (PLLA) were investigated. Dynamic mechanical analysis (DMA) found that CNT via grafting modification with PLLA (CNT‐g‐PLLA) could result in effective reinforcing effects. Tan δ of DMA found that CNT‐g‐PLLA was compatible with the PLLA matrix, giving a single Tg of the composite with a higher CNT‐g‐PLLA loading giving a higher Tg of the composite. Wide angle X‐ray diffraction (WAXD) data demonstrated that CNT could assist the disorder‐to‐order (α′‐to‐α) transition in PLLA crystals but did not lead to a more compact chain packing of the crystal lattice in PLLA composites than in pure PLLA. The equilibrium melting temperature (T) obtained from Hoffman‐Weeks plots were found to increase with increasing CNT‐g‐PLLA content. Small angle X‐ray scattering data revealed that thicknesses of crystal layer and amorphous layer of PLLA both decreased with increasing CNT contents. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 145–152, 2010
Microfibrillated cellulose/cellulose acetate composites: Effect of surface treatment
Authors: Lu Jue , Drzal Lawrence T.
Published: December 2009

Microfibrillated cellulose (MFC), which consists of a web‐like array of cellulose fibrils having a diameter in the range of 10–100 nm, was incorporated into a cellulose acetate (CA) matrix to form a totally biobased structural composite. Untreated and a 3‐aminopropyltriethoxysilane (APS) surface treated MFC was combined with a CA matrix by film casting from an acetone suspension. The effectiveness of the surface treatment was determined by infrared spectroscopy and X‐ray photoelectron spectroscopy. The Young's moduli of APS treated MFC composite films increase with increasing MFC content from 1.9 GPa for the CA to 4.1 GPa at 7.5 wt % of MFC, which is more than doubled. The tensile strength of the composite film increases to a maximum of 63.5 MPa at 2.5 wt % compared to the CA which has a value of 38 MPa. The thermal stability of composites with treated MFC is also better than the untreated MFC. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 153–161, 2010
Vibrational dynamics and heat capacity in poly(L‐lactic acid)
Authors: Porwal Vikas , Singh Mahendra , Chaturvedi Deepika , Tandon Poonam , Dayal Gupta Vishwambhar
Published: December 2009

Poly(L‐lactic acid) (PLLA) (CH(CH3) COO)n is a biodegradable polymer, which exhibits many applications in the biomedical field and where thermoplastics are employed. A comprehensive study of the normal modes and their dispersion in PLLA using Wilson′s GF matrix method as modified by Higgs is being reported. Assignments of calculated normal modes have been made and characteristic features of dispersion curves are discussed. Heat capacity has been calculated via density‐of‐states using Debye relation in the temperature range 10–250 K, which is in fairly good agreement with the experimental data. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 175–182, 2010
Coping with parental cancer: web‐based peer support in children
Authors: Giesbers J. , Verdonck‐de Leeuw I. M. , van Zuuren F. J. , Kleverlaan N. , van der Linden M. H.
Published: December 2009

Objective: To investigate the use and content of web‐based peer support in children coping with parental cancer.

Methods: In children aged above 12 years, 158 forum discussions on the Dutch website www.kankerspoken.nl in a time‐period of 3 months were investigated. Age, gender, number of discussions, participation and main activities on the website were quantitatively assessed. Contents of the discussions were qualitatively analyzed.

Results: In total, 129 children and 8 adults participated on the website with an average age of 15.3 years. The majority was female (80%). On average, a child was on‐line for 3 days and participated in 4 to 5 forum discussions. Main activities on the website were sharing personal experience, providing encouragement/support, providing and seeking information or advice and seeking contact outside of the website. Qualitative content analysis revealed that children regularly faced emotional problems and experienced a lack of understanding and communication in their direct environment.

Conclusions: In dealing with parental cancer, children experience a variety of difficulties. This study offers a window into the use of web‐based peer support by children dealing with parental cancer. Copyright © 2009 John Wiley & Sons, Ltd.
Radiocarbon dating of fossil wood remains buried by the Piancabella rock glacier, Blenio Valley (Ticino, southern Swiss Alps): Implications for rock glacier, treeline and climate history
Authors: Scapozza Cristian , Lambiel Christophe , Reynard Emmanuel , Fallot Jean‐Michel , Antognini Marco , Schoeneich Philippe
Published: December 2009

Fossil wood stem remains of larch (Larix decidua) found 1 m below the surface at the base of the front of the Piancabella rock glacier (46°27′02″N, 9°00′07″E, 2480 m a.s.l.) had a conventional age range of 845 ± 50 14C y BP (UZ‐5545/ETH‐34417), corresponding to a calibrated calendar age range of 1040–1280 AD (790 ± 120 cal BP) with a statistical probability of 95.4 per cent. Based on geomorphological, climatological and geophysical observations, we infer that (1) the treeline in the Medieval Warm Period was about 200 m higher than in the middle of the 20th century, which corresponds to a mean summer temperature as much as 1.2°C warmer than in AD 1950, and (2) that ice within this rock glacier is probably several centuries old and so predates recent climatic events such as the Little Ice Age. Copyright © 2009 John Wiley & Sons, Ltd.
Implementation of the GaN lateral polarity junction in a MESFET utilizing polar doping selectivity
Authors: Collazo Ramón , Mita Seiji , Xie Jinqiao , Rice Anthony , Tweedie James , Dalmau Rafael , Sitar Zlatko
Published: December 2009

The difference in surface energies between the Ga‐polar orientation and the N‐polar orientation of GaN translates into a completely different behavior for the incorporation of intentional and unintentional impurities. Oxygen is found to be an impurity with higher concentration in the N‐polar films than in Ga‐polar films and is the cause of n‐type conductivity observed in N‐polar films. Utilizing this doping selectivity we fabricated a depletion‐mode metal‐semiconductor field effect transistor (MESFET) with n‐type N‐polar domains as source and drain and a Ga‐polar channel on polarity‐patterned wafers. The difference in the electronic properties of the different domains, i.e., as‐grown N‐polar domains are n‐type conductive and Ga‐polar domains are insulating, allows for laterally selective doped areas that can be realized for improving contact resistance to the n‐type conduction channel. Basically, the N‐polar domains acted as the ohmic contacts to the channel localized in a Ga‐polar domain. A MESFET with a Schottky gate was fabricated as an example of implementation of this novel structure showing a lowering in the specific contact resistivity.
Total CNIDR degradation during rain fade conditions of a dual polarized satellite link suffering from double adjacent satellite interference
Authors: Kritikos T. D. , Panagopoulos A. D. , Kanellopoulos J. D.
Published: December 2009

Atmospheric impairments have a significant influence on the performance of modern satellite communication networks, working at Ku, Ka and potentially Q/V frequency bands. Both differential rain attenuation from an adjacent satellite system, operating at the same frequency range, and cross‐polarization phenomena on dual polarized satellite systems due to rain and ice crystals, induce a further aggravation on the already limited signal‐to‐noise‐plus‐total‐interference ratio (CNIDR), due to the frequency and orbital congestion of today's global communication satellite constellation. In the present paper, a new statistical methodology, towards the modelling of CNIDR under rain fade conditions, is proposed to include interference effects by two adjacent satellites, incorporating the impact of correlated fading channels (spatial rainfall inhomogeneity) of multiple slant paths. The method is based on a convective raincell model and the lognormal assumption for both the point rain‐rate statistics and the slant‐path rain attenuation. The obtained numerical results indicate the significant impact of the second interfering satellite on the aggravation of total interference effects. Some simple mathematical formulas for the prediction of the CNIDR, based on the derived theoretical results, and demonstrating the influence of various link parameters on the total link availability statistics, are also presented. Copyright © 2009 John Wiley & Sons, Ltd.
Evolution of near‐surface deformed layers during hot rolling of AA3104 aluminium alloy
Authors: Liu Y. , Frolish M. F. , Rainforth W. M. , Zhou X. , Thompson G. E. , Scamans G. M. , Hunter J. A.
Published: December 2009

In the present study, controlled reheating and breakdown rolling experiments have been carried out and the thickness, structure and uniformity of the resultant near‐surface deformed layer have been characterised by scanning and transmission electron microscopy. High aspect ratio rolling, coupled with an increased rolling speed and rough and worn roll surfaces results in a high degree of interaction between the work roll and work pieces. This generates a shingled surface appearance with a high population of transverse surface cracks and a relatively thick near‐surface deformed layer. In contrast, relatively low aspect ratio rolling, coupled with a reduced rolling speed and freshly ground work roll surfaces generates a relatively thin near‐surface deformed layer. The thickness of the near‐surface deformed layer varies across the alloy surface and is directly related to the shingles, the surface cracks and the distribution of coarse intermetallics. Copyright © 2009 John Wiley & Sons, Ltd.
Optimisation of the plasma electrolytic oxidation process efficiency on aluminium
Authors: Matykina E. , Arrabal R. , Skeldon P. , Thompson G. E.
Published: December 2009

Plasma electrolytic oxidation (PEO) is a surface treatment technology enabling fabrication of adherent thick (50–150 µm) coatings on light metal alloys with significantly enhanced hardness, wear and corrosion resistance compared with other conventional treatments. The technology has the potential to play a significant role in the transport sector for replacement of steel with light‐weight materials of improved durability. A main limitation of PEO lies in its relatively high cost, associated with high energy consumption and low coating efficiency. The present work explores possible routes to improve the process efficiency. It is shown that a combination of conventional pre‐anodising with sequential PEO treatment reduces specific energy consumption up to five times because of an increase of the coating growth rate, up to 10 µm/min, compared with existing PEO processes. A further approach to improved coating efficiency involves PEO in electrolytes with suspended fine or nanoparticles, which results in the formation of thicker coatings in reduced time as a result of the incorporation of the particles from the electrolyte into the coating. Additionally, melting of the coating material during the micro‐arc discharge process leads to formation of stabilised high‐temperature phases, such as tetragonal and cubic zirconia, which provide significantly improved microhardness of the coating material and give a potential for thermal barrier applications. Copyright © 2009 John Wiley & Sons, Ltd.
Mechanical Peeling of Free‐Standing Single‐Walled Carbon‐Nanotube Bundles
Authors: Ke Changhong , Zheng Meng , Zhou Guangwen , Cui Weili , Pugno Nicola , Miles Ronald N.
Published: December 2009

An in situ electron microscopy study is presented of adhesion interactions between single‐walled carbon nanotubes (SWNTs) by mechanically peeling thin free‐standing SWNT bundles using in situ nanomanipulation techniques inside a high‐resolution scanning electron microscope. The in situ measurements clearly reveal the process of delaminating one SWNT bundle from its originally bound SWNT bundle in a controlled‐displacement manner and capture the deformation curvature of the delaminated SWNT bundle during the peeling process. A theoretical model based on nonlinear elastica theory is employed to interpret the measured deformation curvatures of the SWNTs and to quantitatively evaluate the peeling force and the adhesion strength between bundled SWNTs. The estimated adhesion energy per unit length for each pair of neighboring tubes in the peeling interface based on our peeling experiments agrees reasonably well with the theoretical value. This in situ peeling technique provides a potential new method for separating bundled SWNTs without compromising their material properties. The combined peeling experiments and modeling presented in this paper will be very useful to the study of the adhesion interactions between SWNTs and their nonlinear mechanical behaviors in the large‐displacement regime.
Ganzfertigteile bei der Verbundfahrbahnplatte der Bahretalbrücke – Eine Revision nach Ausführung und baubegleitender messtechnischer Überwachung
Authors: Geißler Karsten , Reintjes Karl‐Heinz , Rodemann Jochen
Published: December 2009

Fertigteilbauweisen für die Herstellung der Fahrbahnplatten von Verbundbrücken konnten sich bei kleineren Brücken bereits durchsetzen. Verschiedene Bautypen wurden entwickelt: die VFT‐Bauweise, die Halbfertigteilbauweise, die Ganzfertigteilbauweise. Im Großbrückenbau ist die Anwendung, zumindest in Deutschland, bisher auf einzelne Fälle beschränkt geblieben und eine abgeschlossene Stufe der Entwicklung noch nicht erreicht.

Die Ganzfertigteilbauweise, wie sie bei der Bahretalbrücke eingesetzt wurde, stellt eine Möglichkeit dar, die Vorteile der deutlich schnelleren Herstellung der Fahrbahnplatte im Großbrückenverbundbau effektiv zu realisieren. Besonderes Augenmerk ist bei der Bemessung und Konstruktion auf die Rissproblematik zu legen. Die hier aufgetretenen Rissbildungen begründen sich durch die unterschiedlichen Materialeigenschaften und Herstellungszeitpunkte der Fertigteile und der Ortbetonergänzungen. Mit Hilfe des baubegleitenden Messprogramms für die Bahretalbrücke konnten die Rissbildungen sowie insbesondere die Spannungen in den Anschlussbewehrungen der Fertigteile gut nachvollzogen werden. Letztere liegen aufgrund des “Sammelrisseffektes” deutlich über den Spannungen der Ortbetonbewehrung und können nicht einfach am Zustand II‐Querschnitt berechnet werden. Zusammenfassend kann für die Bahretalbrücke eine gute Beurteilung der Bauweise gegeben werden.

Prefabricated elements for the floor system of Bahretalbridge.

The construction of floor systems of composite bridges, using prefabricated elements in concrete, could already achieve acceptance for smaller bridges. Different types were developed: VFT‐types, semi‐precast construction, precast construction. So far there are only a few cases of prefabricated elements in concrete for bigger bridges in Germany. Using the precast construction presents a possibility to produce floor systems faster and more effective, as done with the Bahretalbridge.

Special attention is to be turned to the calculation and construction of the crack formations. The crack formations seen in this particular construction happened because of the different material property and the production time of the prefabricated elements as well as the addition of floor systems. During the construction progress several measurements helped to understand the appearance of the crack formations. The stresses of the reinforcement between prefabricated elements and the in‐situ concrete are much higher due to the effect of accumulated cracks. Summarizing the construction of the Bahretalbridge was done in a decent way and deserves a positive evaluation.
Integrated wind‐induced response analysis and design optimization of tall steel buildings using Micro‐GA
Authors: Li Q. S. , Zou X. K. , Wu J. R. , Wang Q.
Published: December 2009

This paper presents an integrated procedure for wind‐induced response analysis and design optimization for rectangular steel tall buildings based on the random vibration theory and automatic least cost design optimization technique using Micro‐Genetic Algorithm (GA). The developed approach can predict wind‐induced drift and acceleration responses for serviceability design of a tall building; the technique can also provide an optimal resizing design of the building under wind loads to achieve cost‐efficient design. The empirical formulas of wind force spectra obtained from simultaneous measurements of surface pressures on various rectangular tall building models in wind tunnel tests are verified testified using a published example. Upon the known wind force spectra, the equivalent static wind loads for every storey, such as along‐wind, across‐wind and torsional loads, are then determined and applied for structural analysis including estimation of wind‐induced responses. An improved form of GAs, a Micro‐GA, is adopted to minimize the structural cost/weight of steel buildings subject to top acceleration and lateral drifts constraints with respect to the discrete design variables of steel section sizes. The application and effectiveness of the developed integrated wind‐induced response analysis and design optimization procedure is illustrated through a 30‐storey rectangular steel building example. Copyright © 2009 John Wiley & Sons, Ltd.
Connected capitalism: How business can tackle twenty‐first‐century challenges
Authors: Isdell Neville
Published: December 2009

The economic crisis that shook the world at the end of the first decade of the twenty‐first century is still reverberating and still being felt by businesses and countries in every corner of the globe. The future of capitalism is at stake and, as business leaders, we cannot stand by silently and let others decide the agenda for the role of business in the new century. This article sounds a warning and issues a challenge to global business leaders to speak up about their companies' contributions to the discussion surrounding the new shape of capitalism, to redesign their businesses to take into account the fast‐paced changing economic environment, and to connect their businesses to the communities in which they operate on the regulatory front, the values front, and the sustainability front. © 2010 Wiley Periodicals, Inc.
On the temporal response of active load control devices
Authors: Chow Raymond , van Dam C. P.
Published: December 2009

Flow around airfoils with deploying microtabs and microflaps (or dynamic Gurney flap) have been numerically simulated by solving the unsteady turbulent compressible 2‐D Navier‐Stokes equations with the OVERFLOW 2 solver. Microtabs and microflaps on the order of 1%c were installed in the trailing edge region of the symmetric NACA 0012 airfoil using a Chimera or overset grid topology. The devices were deployed on the order of one characteristic time unit, and the unsteady aerodynamic responses of both devices were compared. The two devices appear to affect the flow similarly by creating a low pressure region aft of the device and changing the Kutta condition. While initial transients varied, the post‐deployment aerodynamic response showed a very similar temporal evolution towards a mean asymptotic solution. Both devices reached 90% of mean steady‐state lift values by approximately nine characteristic time units from the onset of deployment. Drag and pitching moments evolved significantly faster. The temporal development of these devices is not governed by near‐body effects, and instead is an advection driven process. Microflap deployment times of 0.25, 0.50 and 1.00 characteristic time units were also examined. The corresponding mean aerodynamic coefficients for the three deployment times were comparable by one characteristic time unit after deployment. Validation studies with experimental results comparing shedding frequencies and Strouhal numbers for static, deployed microtabs and microflaps were also performed to ensure accurate temporal resolution and convergence of the numerical simulations. Copyright © 2009 John Wiley & Sons, Ltd.
Breast Cancer in Young Women in a Limited‐Resource Environment
Authors: Basro Sarinah , Apffelstaedt Justus P.
Published: December 2009

Background

Despite the higher incidence of breast cancer in young women in developing countries, there is a paucity of data on their management. We present the clinicopathological features and outcome of treatment of women 35 years or younger with breast cancer in a resource‐restricted environment.

Methods

A total of 141 patients who were diagnosed with primary breast cancer at 35 years or younger from January 2000 to June 2008 were retrieved from the cancer registry of a breast clinic at a tertiary hospital and a private breast health center in South Africa. Clinicopathological features, treatment, and survival were analyzed.

Results

Two patients presented with TNM stage 0 (1.4%), 14 with stage I (9.9%), 47 with stage II (33.35%), 47 with stage III (33.3%), and 31 with stage IV (21.9%). Tumor grade was 3 in 47%, grade 2 in 37%, and grade 1 in 16% of patients. One hundred and four patients with stage 0–III disease underwent treatment with curative intent, 83 had a mastectomy, and 12 had breast‐conserving surgery. Ninety patients (86.5%) had chemotherapy, 68 (65.4%) had radiotherapy, and 50 (48.1%) had hormonal therapy. Of 93 patients who completed primary therapy, 4 developed contralateral cancers, 3 had locoregional recurrence, 8 developed synchronous locoregional and distant recurrence, and 19 relapsed with distant metastasis only. The 2‐year disease‐free and overall survival for stage 0–III disease was 48 and 56%, respectively.

Conclusions

Young women with breast cancer in a resource‐limited environment have similar adverse clinicopathological features to those in developed countries. Their disease is more advanced at presentation with poorer outcome. Increased awareness, better systemic therapy, and more comprehensive genetic studies are essential to improve the dismal outcome.
Can Cultural Competency Speak to the Race Disparities in Methadone Dosage Levels?
Authors: Howard Daniel L. , Barrett Nadine J. , Holmes DaJuanicia N.
Published: December 2009

Although national methadone treatment trends have improved substantially from 1988 to 2001, current research has found that African Americans still receive lower dosages of methadone treatment than their white and Hispanic counterparts, which has significant public health concerns. We sought to empirically examine whether the degree of cultural competency within an outpatient substance abuse treatment (OSAT) organization has influence on the methadone dosage levels received by African Americans in 1995 and in 2005. The 1995 and 2005 National Drug Abuse Treatment System Survey (NDATSS) provided a nationally-representative, stratified sample of 618 and 566 OSAT organizations, respectively, of which 121 and 140 affiliated methadone maintenance treatment programs, respectively, were analyzed. The organizations' director and clinical supervisor were surveyed. Fixed-effects linear regression models were fitted with measures of cultural competency, client, and organizational characteristics to assess methadone dosage levels. Culturally-competent units have smaller numbers of methadone clients, greater percentages of clients who receive methadone dosages of less than 40 mg/d, smaller percentages of clients who receive methadone dosages of 80 mg/d or more, and provide a larger number of therapeutic and ancillary services during treatment than non-culturally-competent units. OSAT units with more African Americans are significantly more likely to have clients who receive dosages of less than 40 mg/d and are significantly less likely to have clients who receive dosages of 80 mg/d or more. There is no racial difference among culturally-competent unit clients who receive dosages of less than 40 mg/d, between 40 and 59 mg/d, between 60 and 79 mg/d, and 80mg/d or more. However, among non-culturally-competent units, a racial difference exists among African Americans and other clients who receive these various dosage levels. Research indicating that African Americans receive lower dosages of methadone than their White and Hispanic counterparts may now be explained by whether these clients receive treatment in culturally competent organizations, rather than solely by arguments related to organizational differences in resources, experience and training of staff, staff bias and/or racism. Culturally competent organizations may seek a method of treatment that dissuades “replacing one drug for another,” while simultaneously treating the root cause of the addiction through the provision of comprehensive therapeutic and ancillary support services. Further research is needed to determine if cultural competency results in better substance abuse treatment outcomes for African Americans.
High-fat, sucrose diet impairs geometrical and mechanical properties of cortical bone in mice
Authors: Lorincz Caeley , Reimer Raylene A. , Boyd Steven K. , Zernicke Ronald F.
Published: December 2009

Exposure to diets high in fat and sucrose can induce hyperinsulinaemia, affect Ca and Mg metabolism, and alter bone mineralisation and mechanical properties. The present study assessed morphological and mechanical changes in a murine model exposed to a high-fat/sucrose (HFS) diet, as well as corresponding molecular and endocrine markers of bone turnover. Female C57BL/6 mice (aged 9 weeks) consumed either a low-fat, complex carbohydrate diet or an HFS diet for 10 weeks. At the end of the 10 weeks, serum was collected for biochemical analysis. Tibiae from half the mice (n 15) were randomly selected to be micro-computed tomography scanned and tested to failure in cantilever bending, while the remaining half were prepared for real-time PCR analysis. Serum tartrate-resistant acid phosphatase was significantly elevated in HFS mice, while osteocalcin remained unchanged. Both body mass and percentage body fat were greater in mice fed HFS diet. After adjusting for body mass, tibial structural and morphological properties were adversely affected in the HFS cohort. Cortical thickness, cross-sectional area, and load at maximum were all significantly lower in mice fed HFS diet. Receptor activator of nuclear factor κβ ligand (RANKL) mRNA was significantly upregulated in HFS mice, but osteoprotegerin/RANKL mRNA ratio remained unchanged between cohorts. Moreover, cyclo-oxygenase-2 mRNA tended to be increased in HFS. Thus, ingestion of an HFS diet had a significant adverse effect on mouse bone morphology and mechanics, and these effects were likely due to elevated osteoclast activity associated with the inflammatory state of obesity, and not necessarily osteoclast recruitment/proliferation.
Position Taking in European Parliament Speeches
Authors: Proksch Sven-Oliver , Slapin Jonathan B.
Published: December 2009

This article examines how national parties and their members position themselves in European Parliament (EP) debates, estimating the principal latent dimension of spoken conflict using word counts from legislative speeches. We then examine whether the estimated ideal points reflect partisan conflict on a left–right, European integration or national politics dimension. Using independent measures of national party positions on these three dimensions, we find that the corpus of EP speeches reflects partisan divisions over EU integration and national divisions rather than left–right politics. These results are robust to both the choice of language used to scale the speeches and to a range of statistical models that account for measurement error of the independent variables and the hierarchical structure of the data.
Symposium on ‘Geographical and geological influences on nutrition’ Iodine deficiency in industrialised countries
Authors: Zimmermann Michael B.
Published: December 2009

Iodine deficiency is not only a problem in developing regions; it also affects many industrialised countries. Globally, two billion individuals have an insufficient iodine intake, and approximately 50% of continental Europe remains mildly iodine deficient. Iodine intakes in other industrialised countries, including the USA and Australia, have fallen in recent years. Iodine deficiency has reappeared in Australia, as a result of declining iodine residues in milk products because of decreased iodophor use by the dairy industry. In the USA, although the general population is iodine sufficient, it is uncertain whether iodine intakes are adequate in pregnancy, which has led to calls for iodine supplementation. The few available data suggest that pregnant women in the Republic of Ireland and the UK are now mildly iodine deficient, possibly as a result of reduced use of iodophors by the dairy industry, as observed in Australia. Representative data on iodine status in children and pregnant women in the UK are urgently needed to inform health policy. In most industrialised countries the best strategy to control iodine deficiency is carefully-monitored salt iodisation. However, because approximately 90% of salt consumption in industrialised countries is from purchased processed foods, the iodisation of household salt only will not supply adequate iodine. Thus, in order to successfully control iodine deficiency in industrialised countries it is critical that the food industry use iodised salt. The current push to reduce salt consumption to prevent chronic diseases and the policy of salt iodisation to eliminate iodine deficiency do not conflict; iodisation methods can fortify salt to provide recommended iodine intakes even ifper capitasalt intakes are reduced to <5 g/d.
Investigation on efficiency of non-collinear serial laser beam combination based on Brillouin amplification
Authors: Wang Y.L. , Lu Z.W. , Wang S.Y. , Zheng Z.X. , He W.M. , Lin D.Y.
Published: December 2009

A non-collinear laser beam combination based on Brillouin amplification is proposed. The influence of non-collinear Brillouin amplification on the combination efficiency is analyzed and discussed theoretically. It is shown that an efficiency of 80% can be achieved with the angle between the Stokes and the pump limited to a range of 10°. The theoretical prediction is tested in experiment of non-collinear amplification of one Stokes and one pump. A two-beam combination scheme is designed and a high combination efficiency of 80% is also obtained in this experiment. According to these results, a 20-beam combination scheme is designed to achieve 13.2-J output energy. A very simple construction for a multiple beams combination is designed.
Growth of a ring ripple on a Gaussian electromagnetic beam in a plasma with relativistic - ponderomotive nonlinearity
Authors: Sodha M.S. , Misra S. , Mishra S.K.
Published: December 2009

This paper presents a theoretical model for the propagation/growth of a ring ripple, on a Gaussian electromagnetic beam, propagating in plasma with dominant relativistic-ponderomotive nonlinearity. A paraxial like approach has been invoked to understand the nature of propagation of the ring ripple like instability; in this approach, all the relevant parameters correspond to a narrow range around the irradiance maximum of the ring ripple. The dielectric function is determined by the composite (Gaussian and ripple) electric field profile of the beam. Thus, a unique dielectric function for the beam propagation and a radial field sensitive diffraction term, appropriate to the vicinity of the maximum of the irradiance distribution of the ring ripple has been taken into account. The effect of different parameters on the critical curves has been highlighted and the variation of the beam width parameter with the distance of propagation has been obtained for the three typical cases viz of steady divergence, oscillatory divergence and self-focusing of the ripple.