bluuebunny/crossref_metadata_2025 huggingface dataset:
New experimental device to test the dynamic behavior of fiber assemblies and fibrous composite structures with a focus on larger industrial‐scale‐like samples
Authors: Rebouillat S. , Liksonov D. , Courgey A.
Published: November 2011

This article focuses on the development of an experimental measurement system intended for dynamic mechanical analysis (DMA) of fiber structures. First, a short review of DMA testing procedures is given, followed by an analysis of particularities of DMA application to fibers and rope assemblies. The necessity of developing a dedicated device for fiber assembly and rope applications is pointed out, as the commercial DMA testing devices available are intended for shorter specimens. Thus, the article insists on the underlying necessity to come up with a measurement device for much longer fiber specimens and a testing procedure therewith. Then the article presents the main concepts of the new device and its operation. Three different operating modes are presented with explanations of their functioning, their particularities, and the interest for rope testing. After that, the implementation of the testing device prototype is presented, describing the mechanical set up, electromagnetic elements, power and acquisition circuitry and software. At last, preliminary experimental results are provided demonstrating the feasibility of this solution and indications concerning the potential future developments of this kind of rope testing systems are given. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
A supported titanium postmetallocene catalyst: Effect of selected conditions on ethylene polymerization
Authors: Pietruszka Anna , Białek Marzena , Czaja Krystyna
Published: November 2011

Ethylene polymerization with a titanium complex [N,N‐ethylenebis(3‐methoxysalicylideneiminato)titanium dichloride] immobilized on the magnesium support with the formula MgCl2(THF)0.32(Et2AlCl)0.36 was studied. In particular, the effects of polymerization temperature, monomer pressure, and polymerization time on the activity of the catalyst and on the polyethylene properties (molecular weight and its distribution, melting point, crystallinity, and bulk density) were evaluated. The findings of investigations prove that the studied supported titanium catalyst is highly active in ethylene polymerization, and its activity increases with increasing temperature and monomer pressure. Moreover, stability of the catalytic systems is dependent on the activator type used. Me3Al, when employed as an activator, makes the catalytic system undergo no deactivation in practice. The catalyst coupled with MAO turned out less stable. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
NR/SBR/organoclay nanocomposites: Effects of molecular interactions upon the clay microstructure and mechano‐dynamic properties
Authors: Tavakoli Mitra , Katbab Ali Asghar , Nazockdast Hossein
Published: November 2011

Nanocomposites based on (70/30) blends of natural rubber (NR), styrene‐butadiene rubber (SBR), and organoclay (OC) have been prepared successfully via melt‐mixing process. Effects of the extent of polymers/clay interactions upon the developed microstructure, fatigue life, and dynamic energy loss by the nanocomposites have been investigated. Maleated EPDM (EPDM‐g‐MAH) and epoxidized NR (ENR50) were employed as compatibilizer. Nanocomposites were characterized by means of X‐ray diffractometer (XRD), transmission electron microscope (TEM), scanning electron microscope, atomic force microscopy, root mean square, and dynamic mechanical thermal analysis. EPDM‐g‐MAH showed more potential in enhancing dispersion of the clay nanolayers and their interaction with rubber phases. More potential for separating and dispersing the clay nanoplatelets with better interface enhancement was exhibited by EPDM‐g‐MAH as compatibilizer. This was consistent with higher resistance towards large strain cyclic deformations along with more heat build‐up characteristics showed by EPDM‐g‐MAH based nanocomposites especially at compatibilizer/organoclay ratio of 3. Pronounced non‐terminal behavior within low frequency region was also observed for melt storage modulus of this nanocomposite, indicating higher extent of intercalation/exfoliation microstructure with reinforced interfaces than the nanocomposite generated by ENR50. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Surface photografting initiated by benzophenone in water and mixed solvents containing water and ethanol
Authors: Li Guangwu , He Guanyang , Zheng Yunan , Wang Xiaoxiao , Wang Huiliang
Published: November 2011

Photografting reactions are usually carried out in organic solvents due to the water insoluble nature of photoinitiators such as benzophenone (BP). This work reports the effect of water and mixed solvents containing water and ethanol on the surface photografting of methacrylic acid (MAA) onto polyethylene initiated by BP. The percent grafting increased with the increase of water volume ratio in the mixed solvent, and BP showed the highest photoinitiation efficiency when dissolved in pure water solvent. Effects of BP concentration, monomer concentration, and monomer type on photografting were studied. The percent grafting showed the maximum at a lower BP concentration (0.20 mol/mol %) in pure water solvent than that (0.60 mol/mol %) in the mixed solvent with 90 v/v % water. The percent grafting first increased with the increase of monomer concentration till 3 mol L−1 and then decreased. Acrylic acid (AA) could also be photografted onto polyethylene by BP in the mixed solvents. UV–visible spectroscopic examinations revealed that the λmax of π–π* transitions of BP red shifted as the increase of the water volume ratio, i.e., the polarity of the solvent. The excitation of BP in solvents with a higher polarity under UV irradiation requires less energy, so the photografting initiated by BP is easier to occur. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis of carbon nanostructures from residual solids waste tires
Authors: Mis‐Fernández Ricardo , Rios‐Soberanis Carlos R. , Arenas‐Alatorre Jesús , Azamar‐Barrios José A.
Published: November 2011

This article presents the results of the synthesis and morphological characterization of carbon nanostructures obtained from the decomposition of residual solid from waste tires (RSWT) in quartz tubes under reduced pressure (1.33 Pa) at 900°C for 15 min. The synthesis led to the formation of two phases, a fragmented solid black powder composed of multi‐walled carbon nanotubes (MWCNTs), onion‐type fullerenes, and spheres, and a very bright metallic dark film. Analysis by microscopy (SEM and TEM) showed that the MWCNTs had an average diameter of approximately 25 nm and a length greater than 100 nm while the diameter of the onion‐type fullerenes was found to be 8 nm. The nanospheres showed different diameters ranging from 500 nm to 1.5 μm, and some had a metallic core surrounded by layers of carbon. The infrared spectra of the nanotubes exhibited absorption bands at 1558 and 1458 cm−1, corresponding to CC and CC bonds, and signals at 3438 and 1080 cm−1 related to the OH and CO groups from oxidized graphite as it was identified in the dark film. The Raman spectra of the carbon nanostructures present D and G‐bands at 1331 and 1597 cm−1, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and adsorption properties, toward some heavy metal ions, of a new polystyrene‐based terpyridine polymer
Authors: Saadeh Haythem A. , Shairah Eman A. Abu , Charef Noureddine , Mubarak Mohammad S.
Published: November 2011

A novel polymeric ligand having 2,2′:6′,2″‐terpyridine as pendant group was prepared through a Williamson type etherification approach for the reaction between 4′‐hydroxy‐2,2′: 6′,2″‐terpyridine and the commercially available 4‐chloromethyl polystyrene. The chelating properties of the new polymer toward the divalent metal ions (Cu2+, Zn2+, Ni2+, and Pb2+) in aqueous solutions was studied by a batch equilibration technique as a function of contact time, pH, mass of resin, and concentration of metal ions. The amount of metal‐ion uptake of the polymer was determined by using atomic absorption spectrometry. Results of the study revealed that the resin exhibited higher capacities and a more pronounced adsorption toward Pb2+ and that the metal‐ion uptake follows the order: Pb2+ > Cu2+ > Zn2+ > Ni2+. The adsorption and binding capacity of the resin toward the various metal ions investigated are discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and characterization of polyvinyl borate/polyvinyl alcohol (PVB/PVA) blend nanofibers
Authors: Koysuren Ozcan , Karaman Mustafa , Dinc Havva
Published: November 2011

In this study, it was aimed to prepare polyvinyl borate/polyvinyl alcohol blend nanofibers by electrospinning process. Polyvinyl borate was synthesized by the condensation reaction of polyvinyl alcohol and boric acid. Polyvinyl borate itself was not suitable for electrospinning process. To improve fiber formation capability, polyvinyl borate was blended with polyvinyl alcohol before electrospinning process. A series of nanofibers with various polyvinyl borate concentrations in polyvinyl alcohol were prepared. Homogeneous and highly porous mat containing 100–250 nm diameter nanofibers were obtained by electrospinning process. According to the FTIR results, boron atoms were found to be integrated into the polymer network. There is not any significant effect of polyvinyl borate content on fiber morphologies according to SEM images. The blend composition with the highest polyvinyl borate content was found to be suitable for thermally stable nanofiber formation according to the TGA results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Iodination of stable aromatic diazonium salt using crosslinked poly (4‐vinylpyridine)‐supported iodide
Authors: Karimi Zarchi Mohammad Ali , Ebrahimi Nahid
Published: November 2011

An efficient and simple method for the iodination of stable arenediazonium salts has been developed by using a polymer‐supported iodide. The arenediazonium chlorides, Ar‐NCl−, were obtained by the reaction between primary aryl amine and sodium nitrite in the presence of concentrated hydrochloric acid (HCl) at low temperature (0–5°C). By ion exchange reaction between Ar‐NCl− with NaBF4, the stable arenediazonium tetrafluoroborates, Ar‐NBF, were prepared. Ar‐NBF, were then converted to aryl iodides by crosslinked poly (4‐vinylpyridine)‐supported iodide, [P4‐VP]I, in acetonitrile at room temperature. The spent polymeric reagent was regenerated and reused for several times without losing its activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of neutralization on the structure and properties of an ionomer
Authors: Gao Yan , Choudhury Namita Roy , Dutta Naba K.
Published: November 2011

The structure, morphology, and properties of an ionomer, poly(ethylene‐acrylic‐acid) neutralized by zinc salts (PI) depend on the free carboxylic acid content. In this work, metal acetates (Na, Zn, and Al acetates) were used to control the neutralization levels. A wide range of techniques were used, such as spectroscopic Fourier transform infrared spectroscopy (FTIR), thermal [thermogravimetric analysis, modulated differential scanning calorimetry (MDSC), and dynamic mechanical analysis (DMA)], mechanical (tensile measurement), and small angle neutron scattering (SANS). The melt rheological properties of the samples were also examined. The results show that metal acetate neutralizes free acrylic acid in the ionomer, which has the primary role in controlling ionic association. The number of ionic groups in ionic domains and multiplets in the matrix is dependent on the neutralization level. Metal valence determines the ionic domain or multiplet structure (FTIR), further properties of PI. Dynamic mechanical properties, the ionic transition behaviour, and the mechanical properties are improved compared with PI using monovalent cation (Na+), but decreased using trivalent cation (Al3+) or shows less significant changes due to steric effects. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of nanoclay and ZnO on the physical and chemical properties of wood polymer nanocomposite
Authors: Deka Biplab K. , Maji Tarun K.
Published: November 2011

Wood polymer composite (WPC) was prepared by using solution blended high density polyethylene, low density polyethylene, polypropylene, and poly(vinyl chloride) with Phragmites karka wood flour and polyethylene‐co‐glycidyl methacrylate (PE‐co‐GMA). The effect of addition of nanoclay and ZnO on the properties of the composite was examined. The distribution of silicate layers and ZnO nanopowder was studied by X‐ray diffractrometry and transmission electron microscopy. The improvement in miscibility among polymers due to addition of PE‐co‐GMA as compatibilizer was studied by scanning electron microscopy. WPC treated with 3 phr each of clay and ZnO showed an improvement in thermal stability and UV resistance. Mechanical and flame retarding properties were also enhanced after the incorporation of clay/ZnO nanopowder. Both water and water vapor absorption were found to decrease due to inclusion of nanoclay and ZnO in WPC. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis, characteristic, and properties of waterborne polyurethane based on natural rubber
Authors: Saetung Anuwat , Kaenhin Lalita , Klinpituksa Pairote , Rungvichaniwat Adisai , Tulyapitak Tulyapong , Munleh Summa , Campistron Irène , Pilard Jean‐François
Published: November 2011

A series of new waterborne polyurethanes (WPUs) was successfully prepared by prepolymer process from renewable source, hydroxytelechelic natural rubber (HTNR), with different amounts of DMPA (1.6–8.4 wt %), different molecular weights (1000–4000 g mol−1), and different levels of epoxide (0%–20%) of HTNR. It was found that the urethane conversions of prepolymer were over 80% as calculated by FTIR technique. The resulting HTNR2000‐based WPUs exhibit a uniform particle size, which decreases from 420‐ to 83‐nm diameters with an increase in the amount of DMPA from 2.9 to 6.6 wt %. The particle size also decreases with an increase of soft segment or with an increase of epoxide content. They are well stable more over 6 months and without a significant difference in particle size compared with starting of them. Chemical structure of WPU films was confirmed by FTIR, 1H‐NMR, and 13C‐NMR. Molecular weight and polydispersity were determined by SEC. In addition, thermal and water uptake properties were investigated. The experimental results reveal that the DMPA content, molecular weight of HTNR, and epoxide content play an important key role in water uptake and thermal properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Tailoring the surface architecture of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) scaffolds
Authors: Vigneswari S. , Majid M. I. A. , Amirul A. A.
Published: November 2011

This study was designed to determine whether the surface modifications of the various poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) [P(3HB‐co‐4HB)] copolymer scaffolds fabricated would enhance mouse fibroblast cells (L929) attachment and proliferation. The P(3HB‐co‐4HB) copolymer with a wide range of 4HB monomer composition (16–91 mol %) was synthesized by a local isolate Cupriavidus sp. USMAA1020 by employing the modified two‐stage cultivation and by varying the concentrations of 4HB precursors, namely γ‐butyrolactone and 1,4‐butanediol. Five different processing techniques were used in fabricating the P(3HB‐co‐4HB) copolymer scaffolds such as solvent casting, salt‐leaching, enzyme degradation, combining salt‐leaching with enzyme degradation, and electrospinning. The increase in 4HB composition lowered melting temperatures (Tm) but increased elongation to break. P(3HB‐co‐91 mol % 4HB) exhibited a melting point of 46°C and elongation to break of 380%. The atomic force analysis showed an increase in the average surface roughness as the 4HB monomer composition increased. The mouse fibroblasts (L929) cell attachment was found to increase with high 4HB monomer composition in copolymer scaffolds. These results illustrate the importance of a detailed characterization of surface architecture of scaffolds to provoke specific cellular responses. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and effect of surface modified nano ZnO in natural rubber vulcanization
Authors: Thomas Shaji P. , Mathew E. J. , Marykutty C. V.
Published: November 2011

It is well known that surface of ZnO acts both as a reactant and a catalytic reaction template in rubber vulcanization by activating and bringing together reactants. The particles of accelerators, fatty acid, and sulfur diffuse through the polymer matrix and get adsorbed on the surface of ZnO, forming intermediate complexes. Hence dispersion of ZnO in the elastomer matrix is a determining parameter. Capping is one of the novel techniques for increasing ZnO‐stearic acid/accelerator interaction, thereby enhancing their activities. During the sol–gel precipitation of nano ZnO, if a suitable capping agent is added, agglomeration of ZnO particles gets reduced, leading to the formation of nano particles. Since only very few studies are found reported on synthesis of accelerator‐capped ZnO and its application in rubber vulcanization, attempts have been made in this study to synthesize our novel accelerator N‐benzylimine aminothioformamide (BIAT)‐capped‐stearic acid‐coated nano ZnO (ZOBS), and BIAT‐capped ZnO (ZOB) to investigate their effects in natural rubber (NR) vulcanization. Efforts have also been made to synthesize stearic acid‐coated nano zinc phosphate (ZPS) with an aim to find an alternative to conventional ZnO in vulcanization. Mechanical properties like tensile strength, tear resistance, abrasion resistance, and compression set were found out. Swelling values of the vulcanizates as a measure of crosslink densities were also determined. Optimum dosage of ZOBS and a combination of ZOB and ZPS were also derived and found that capped ZnO is superior in NR vulcanization to conventional ZnO in improving cure properties including scorch safety and mechanical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Reconstructing the Locomotor Repertoire of Protopithecus brasiliensis. II. Forelimb Morphology
Authors: Halenar Lauren B.
Published: November 2011

The majority of previous publications have suggested that the large‐bodied subfossil Protopithecus brasiliensis was a suspensory ateline with a locomotor repertoire similar to that of extant Ateles and Brachyteles. This is unexpected, as the cranial morphology of Protopithecus is very similar to Alouatta, a genus usually classified as a deliberate quadrupedal climber. Complicating matters further, as Protopithecus is twice as large as Ateles and Brachyteles, its ability to be as suspensory as those two genera is suspect and a terrestrial component of the locomotor repertoire has also been hypothesized. The forelimbs of Protopithecus, while relatively elongated as would be expected in a suspensory animal, are also quite robust and show several adaptations for climbing. To test these hypotheses about the fossil locomotor repertoire, three‐dimensional geometric morphometric techniques were used to quantify the shapes of the fossil distal humerus and proximal ulna and then compare them to a broad sample of extant primates with varying body sizes and locomotor patterns. Results indicate that Protopithecus is similar to Ateles and Brachyteles in terms of its forelimb joint surface morphology; however, the overall locomotor repertoire of the fossil is reconstructed as more flexible to include forelimb suspension, climbing, and potentially some terrestrial ground use. The combination of suspensory locomotion and quadrupedal climbing supported here indicates the beginnings of the evolutionary transition from a more acrobatic style of locomotion in the last common ancestor of alouattins and atelins to the current pattern of howler locomotion. Anat Rec, , 2011. © 2011 Wiley Periodicals, Inc.
Craniofacial Adaptations to Tree‐Gouging Among Marmosets
Authors: Forsythe Elliott C. , Ford Susan M.
Published: November 2011

Many primates rely on exudates as dietary items, but comparatively few elicit exudates via tree‐gouging. Marmosets are the only haplorhines to extensively utilize this behavior during feeding. Several studies have explored craniofacial adaptations to this behavior, but its morphological correlates are a matter of debate. Various studies suggest that gougers exhibit bite‐force maximizing adaptations, load resistance adaptations, and/or jaw‐gape maximizing characteristics. All of these seemingly incompatible biomechanical adaptations have previously been argued for marmosets. This study utilizes multivariate and univariate analyses to compare gouging and non‐gouging callitrichids for 25 biomechanically relevant craniofacial variables to address this form–function debate. We show that marmosets differ from non‐gouging callitrichids in few craniofacial characteristics. Specifically, three craniofacial features differentiate them from non‐gougers: relatively longer basicrania, narrower palates, and shorter coronoid processes. We suggest that these characteristics are consistent with a mosaic model for gouging adaptations. In particular, we argue that: (a) shortening the coronoid processes facilitates relatively larger maximum jaw‐gapes, (b) basicranial elongation facilitates the extended neck/head posture utilized by marmosets during gouging to maximize gapes, and (c) narrowing the palate serves to more effectively dissipate forces through the maxillary canines during substrate anchoring. Previous studies have documented some of these characters as typical of marmosets, but this combination has not been interpreted as core elements of the marmoset adaptive complex. Marmosets exhibit a unique anatomical repertoire that biomechanically adapts them to both increased jaw‐gape and the force dissipation regime associated with tree‐gouging. Comparisons among marmoset taxa may enlighten the evolutionary history of the features reported here. Anat Rec,, 2011. © 2011 Wiley Periodicals, Inc.
Reconstructing the Locomotor Repertoire of Protopithecus brasiliensis. I. Body Size
Authors: Halenar Lauren B.
Published: November 2011

An accurate body size estimate is essential for reconstructing and interpreting many aspects of the paleobiology of an extinct taxon. With this in mind, the purpose of this study is two‐fold: first, to create statistically robust predictive regression equations for body mass, total body length, and head and body length from postcranial elements using a platyrrhine reference sample, data that do not exist elsewhere in the literature; and, second, to apply those regression equations to the “giant” subfossil platyrrhine Protopithecus brasiliensis, a little‐studied taxon represented by a nearly complete skeleton. Building on results of previous work with other primate groups, different skeletal elements, subgroups of the reference sample, and regression models lead to different body size estimates with different standard errors and prediction errors. However, relatively tight clusters of estimates around 20 kg, total length of 1,675 mm, and head and body length of 710 mm are obtained, placing the fossil in the size range of a large male baboon. While not quite as large as the original 25 kg body mass estimate for the fossil, this new estimate is still approximately 150% larger than the largest living New World monkey. Confirmation of its place in a large‐bodied size class of platyrrhines has a profound effect on reconstructing the locomotor repertoire of Protopithecus and the evolutionary trajectory of the alouattin lineage. Anat Rec, , 2011. © 2011 Wiley Periodicals, Inc.
Evolutionary Morphology, Platyrrhine Evolution, and Systematics
Authors: Rosenberger Alfred L.
Published: November 2011

This special volume of the Anatomical Record focuses on the evolutionary morphology of New World monkeys. The studies range from three‐dimensional surface geometry of teeth to enamel ultrastructure; from cranioskeletal adaptations for eating leaves and seeds to the histology of taste bud proxies; from the architecture of its bones to the mechanoreceptors of the tail's skin; from the physical properties of wild foods to the feeding biomechanics of jaws and skull; from the shapes of claws and fingertips, and of elbows, to the diversity and morphology of positional behavior; from the vomeronasal organ and its biological roles to links between brains, guts, sociality, and feeding; from the gum‐eating adaptations of the smallest platyrrhines to the methods used to infer how big the largest fossil platyrrhines were. They demonstrate the power of combining functional morphology, behavior, and phylogenetic thinking as an approach toward reconstructing the evolutionary history of platyrrhine primates. While contributing new findings pertaining to all the major clades and ecological guilds, these articles reinforce the view that platyrrhines are a coherent ecophylogenetic array that differentiated along niche dimensions definable principally by body size, positional behavior, and feeding strategies. In underlining the value of character analysis and derived morphological and behavioral patterns as tools for deciphering phylogenetic and adaptational history, doubts are raised about a competing small‐bore morphological method, parsimony‐based cladistic studies. Intentionally designed not to enlist the rich reservoir of platyrrhine evolutionary morphology, an empirical assessment of the costs incurred by this research stratagem reveals inconsistent, nonrepeatable, and often conflicting results. Anat Rec, 2011. © 2011 Wiley Periodicals, Inc.
Are We Looking for Loads in all the Right Places? New Research Directions for Studying the Masticatory Apparatus of New World Monkeys
Authors: Vinyard Christopher J. , Taylor Andrea B. , Teaford Mark F. , Glander Kenneth E. , Ravosa Matthew J. , Rossie James B. , Ryan Timothy M. , Williams Susan H.
Published: November 2011

New World monkeys display a wide range of masticatory apparatus morphologies related to their diverse diets and feeding strategies. While primatologists have completed many studies of the platyrrhine masticatory apparatus, particularly morphometric analyses, we collectively acknowledge key shortcomings in our understanding of the function and evolution of the platyrrhine feeding apparatus. Our goal in this contribution is to review several recent, and in most cases ongoing, efforts to address some of the deficits in our knowledge of how the platyrrhine skull is loaded during feeding. We specifically consider three broad research areas: (1) in vivo physiological studies documenting mandibular bone strains during feeding, (2) metric analyses assessing musculoskeletal functional morphology and performance, as well as (3) the initiation of a physiological ecology of feeding that measures in vivo masticatory mechanics in a natural environment. We draw several conclusions from these brief reviews. First, we need better documentation of in vivo strain patterns in the platyrrhine skull during feeding given their empirical role in developing adaptive hypotheses explaining masticatory apparatus form. Second, the greater accuracy of new technologies, such as CT scanning, will allow us to better describe the functional consequences of jaw form. Third, performance studies are generally lacking for platyrrhine jaws, muscles, and teeth and offer exciting avenues for linking form to feeding behavior and diet. Finally, attempts to bridge distinct research agendas, such as collecting in vivo physiological data during feeding in natural environments, present some of the greatest opportunities for novel insights into platyrrhine feeding biology. Anat Rec, , 2011. © 2011 Wiley Periodicals, Inc.
A comparative analysis of the information‐seeking behavior of visually impaired and sighted searchers
Authors: Sahib Nuzhah Gooda , Tombros Anastasios , Stockman Tony
Published: November 2011

Understanding search behavior is important and leads to more effective interfaces that support searchers throughout the search process. In this article, through an observational user study, we investigate the search behavior of 15 visually impaired and 15 sighted searchers while they complete complex search tasks online. We study complex search tasks because they are challenging, cognitively intensive and affect performance of searchers. We compare the behavior of the two groups of searchers at four stages of the information‐seeking process namely, Query Formulation, Search Results Exploration, Query Reformulation, and Search Results Management. For each stage, we identify research questions to investigate the impact of speech‐based screen readers on the information‐seeking behavior of visually impaired users. Significant differences were observed during query formulation and in the use of query‐level support features such as query suggestions and spelling suggestions. In addition, screen‐reader users submitted a lower number of queries and displayed comparatively limited exploratory behavior during search results exploration. We investigate how a lack of visual cues affected visually impaired searchers' approach towards query reformulation and observed different strategies to manage and use information encountered during the search process. We discuss the implications that our findings have for the design of search interfaces and propose a set of design guidelines to consider when designing interfaces that are usable and accessible with screen readers. This work also enhances our understanding of search behavior when using an auditory interface and could be useful when designing audio‐based information retrieval systems.
Changes in reactive stratospheric gases due to a change in Brewer–Dobson circulation: results from a simple model
Authors: Cook Peter A. , Roscoe Howard K.
Published: November 2011

Amounts of source gases with stratospheric sinks (CFCs, N2O, CH4) are affected by changes in Brewer–Dobson circulation. Source gases and their degradation products are important for atmospheric chemistry and climate. With a simple model, we examine how amounts and lifetimes of source gases and products depend on speed of the circulation. Transient results differ from steady‐state and stratospheric results differ from those for stratosphere plus troposphere. Increases in speed increase the stratospheric burden of source gases, but reduce products and reduce total burdens and lifetimes of source gases. Copyright © 2011 Royal Meteorological Society
Mikrobewehrter Ultrahochleistungsbeton
Authors: Schnellenbach‐Held Martina , Prager Melanie
Published: November 2011

Ultrahochleistungsbeton (Ultra High Performance Concrete, UHPC) erfordert zur Sicherstellung ausreichender Duktilität den Einsatz einer “Bewehrung”, die meist in Form von Fasern während des Mischprozesses zugegeben wird. Herstellung und Verarbeitung werden hierdurch beeinflusst, und infolge der zufälligen Ausrichtung und Verteilung der Fasern innerhalb der UHPC‐Matrix ist eine zuverlässige Berechenbarkeit des Materialverhaltens nicht gewährleistet. Als Folge einer fehlenden Betondeckung führen oberflächennahe Stahlfasern zudem zu Korrosionsflecken.

Im vorliegenden Beitrag wird ein Faserersatz in Form einer gerichteten Mikrobewehrungsmatte aus dünnen Stahldrähten hinsichtlich des Trag‐ und Verformungsverhaltens in UHPC vorgestellt. Dabei werden die Ergebnisse experimenteller Untersuchungen von faser‐ und mikrobewehrtem UHPC mit identischem Stahlgehalt verglichen sowie der Einfluss auf das Tragverhalten bei unterschiedlicher Ausrichtung der Mikrobewehrung und Verdoppelung des Stahlgehaltes dargestellt. Begleitende numerische Untersuchungen belegen, dass das Trag‐ und Verformungsverhalten des Verbundwerkstoffes zuverlässig zu berechnen ist.

Micro‐reinforced Ultra High Performance Concrete (UHPC) – Structural behaviour

With intent to provide a ductile failure and to use UHPC to full capacity usually steel fibres are added during the mixing process. The impaired workability as well as random orientation and spreading of the fibres are beside the spots of corrosion resulting from near‐surface fibres the main disadvantages of the use of steel fibres.

Within this paper a micro‐reinforcement as replacement for steel‐fibres is introduced with respect to the structural behaviour of the composite material. To outline the comparability in structural behaviour the results of the experimental investigations on micro‐reinforced UHPC are constantly compared to the results of fibered UHPC. Additional investigations concerning the orientation of the micro‐reinforcement show an influence on the structural failure. Beside the experimental tests nonlinear finite element simulations were performed. The simulations and the test results show substantial similarities in crack propagation, ultimate deformation and bearing capacity.
Überarbeitung der DAfStb‐Richtlinie “Betonbau beim Umgang mit wassergefährdenden Stoffen”
Authors: Wiens Udo , Brauer Norbert , Dargel Helge‐Jürgen
Published: November 2011

Die DAfStb‐Richtlinie “Betonbau beim Umgang mit wassergefährdenden Stoffen” hat sich seit ihrer Ersterscheinung im Jahr 1996 im langjährigen praktischen Einsatz bewährt. Im Jahr 2004 erfolgte im Zuge der Anpassung an die neue Normengeneration im Betonbau, DIN 1045:2001‐7, Teile 1 bis 4 und DIN EN 206‐1:2001‐07, die Veröffentlichung einer neuen Ausgabe der Richtlinie. Die hohe Akzeptanz bei den zuständigen Behörden und die breite Anwendung der Richtlinie bei Planern und Bauausführenden zeigen, dass die Betonbauweise für die zuverlässige Abdichtung gegenüber wassergefährdenden Flüssigkeiten geeignet ist und damit dem Besorgnisgrundsatz des sec 19g des alten WHG in vorbildlicher Weise Rechnung getragen wird. Die Neufassung des Wasserhaushaltsgesetzes vom 31. Juli 2009, das zum 01. März 2010 in Kraft getreten ist, sowie die geplante neue Bundes‐ Verordnung über Anlagen zum Umgang mit wassergefährdenden Stoffen (VAUwS), die die 16 Anlagenverordnungen der Länder (VAwS) ablösen wird, bringen Änderungen mit sich, die den DAfStb veranlasst haben, neben der Durchführung der erforderlichen Anpassungen an den Eurocode 2 die Richtlinie aus dem Jahr 2004 erneut zu überarbeiten. Die Richtlinie wird in Kürze mit dem Ausgabemonat März 2011 veröffentlicht.

Die bereits bei der Erstausgabe der Richtlinie im Jahr 1996 in einem breiten Konsens aller beteiligten Kreise entwickelten Dichtheitsnachweise und die Festlegung der stofflichen Anforderungen an Dichtflächen aus Beton wurden seit dieser Zeit kaum verändert und lediglich dem jeweils neuen Regelungsstand der Normen aus dem Betonbau angepasst. Zum besseren Verständnis der Zusammenhänge gibt der Beitrag eine Übersicht über die verschiedenen Dichtheitsnachweise der Richtlinie. Da die Dichtheit einer Betonkonstruktion wesentlich von der Betonzusammensetzung abhängt, werden dem Planer ebenfalls wichtige Hinweise zur Wahl der geeigneten Baustoffe gegeben. Ein Praxisbeispiel rundet das Gesamtbild ab. Die geplanten wesentlichen Änderungen gegenüber der Ausgabe 2004 werden im letzten Abschnitt zusammenfassend dargestellt.
Quality of life and health status before and after ileal pouch–anal anastomosis for ulcerative colitis
Authors: Heikens J T , de Vries J , Goos M R E , Oostvogel H J , Gooszen H G , van Laarhoven C J H M
Published: November 2011

Background

Ileal pouch–anal anastomosis (IPAA) is considered the surgical treatment of choice for patients with ulcerative colitis. Quality of life (QoL) and health status are the most important patient-related outcomes. Studies investigating QoL are often cross-sectional and focus on health status. This longitudinal study evaluated QoL and health status after IPAA for ulcerative colitis and compared these with reference data from a healthy population.

Methods

Patients with ulcerative colitis who underwent a pouch operation between 2003 and 2008 completed validated questionnaires for QoL and health status. Questionnaires were completed before pouch surgery, and 6, 12, 24 and 36 months after operation. The effect of IPAA on QoL and health status was analysed, and data were compared with reference values from the healthy Dutch population.

Results

Data were obtained for 30 of the 32 patients. Six months after IPAA, QoL was at least comparable with that of the reference population in four of six domains. Twelve months after IPAA, overall QoL had improved, supported by findings in three QoL domains. Six months after IPAA, health status was comparable to that of the reference population in three of eight dimensions, and after 3 years it was at least comparable in five dimensions.

Conclusion

QoL and health status increased after IPAA and reached levels comparable with those of the healthy reference population in a majority of domains and dimensions. QoL was restored first after IPAA, followed by health status.
Sirolimus‐ versus paclitaxel‐eluting stents for coronary bifurcations intervention
Authors: Qian Juying , Chen Zhangwei , Ma Jianying , Ge Junbo
Published: November 2011

Backgrounds: Relative efficacy and safety of sirolimus‐eluting stents (SES) compared with paclitaxel‐eluting stents (PES) remains controversial. It is unknown whether there are different effect and safety in coronary bifurcation treatment between SES and PES. Objectives: The meta‐analysis was performed to compare the clinical outcomes of SES and PES in coronary bifurcation intervention. Methods: Five head‐to‐head clinical trials of SES versus PES in coronary bifurcation intervention were included. A total of 2,567 patients were involved in the meta‐analysis. Mean follow‐up period ranged from 6 to 35 months. The primary end points were the need for target lesion revascularization (TLR) and main‐branch restenosis. Secondary end points were target vessel revascularization (TVR), cardiac death, major adverse cardiac events (MACE), and stent thrombosis. Results: Compared with PES, SES significantly reduced the risk of TLR (5.3% vs. 10.6%, odds ratio (OR) 0.52; 95% confidence interval (CI) = 0.38–0.70, P < 0.001), main‐branch restenosis (4.59% vs. 12.59%, OR 0.31; 95% CI = 0.18–0.55, P < 0.001) and TVR (7.05% vs. 12.57%, OR 0.58; 95% CI = 0.42–0.81, P = 0.001) in coronary bifurcation intervention. In addition, SES group also had a significantly lower incidence of MACE (8.20% vs. 14.13%, OR 0.58; 95% CI = 0.40–0.84, P = 0.004) than PES group. However, there were no statistical difference with respect to the incidence of cardiac death (1.64% vs. 1.09%, P = 0.19) and stent thrombosis (0.84% vs. 1.08%, P = 0.64) between SES and PES groups. Conclusions: Compared with PES, SES reduced the incidence of TLR, main‐branch restenosis and MACE in coronary bifurcation intervention, while the risk of stent thrombosis was similar between SES and PES groups. © 2011 Wiley Periodicals, Inc.
Red‐Emitting Dyes with Photophysical and Photochemical Properties Controlled by pH
Authors: Novakova Veronika , Miletin Miroslav , Kopecky Kamil , Zimcik Petr
Published: November 2011

New unsymmetrical zinc azaphthalocyanines, bearing one substituted aniline as a peripheral substituent, were prepared by using a statistical condensation approach. Both fluorescence and singlet oxygen quantum yields were extremely low in DMF (ΦF<0.01, ΦΔ<0.02, respectively), but increased after the addition of sulfuric acid, reaching values comparable to controls without aniline substituents (ΦF=0.22–0.29, ΦΔ=0.40–0.59, respectively). This behavior was attributed to the deactivation of excited states by intramolecular charge transfer from a donor site (aniline), which was blocked after protonation in acidic media. In the protonated form, all of the compounds efficiently emitted light with λem in the region of 662–675 nm. The investigated compounds were anchored to dioleoylphosphatidylcholine (DOPC) unilamellar vesicles and showed response to buffer pH. They were highly fluorescent at low pH values and almost nonfluorescent in neutral solutions. The pKa values were determined in DOPC vesicles and ranged between 2.2 and 4.2.
Strong Binding Affinity of a Zinc–Porphyrin‐Based Receptor for Halides through the Cooperative Effects of Quadruple CH Hydrogen Bonds and Axial Ligation
Authors: Lee Chi‐Hwa , Lee Sangeun , Yoon Hongsik , Jang Woo‐Dong
Published: November 2011

A new type of host compound (1), tetraphenyl zinc–porphyrin (ZnTPP) that contains four triazole groups at the ortho‐position of each phenyl group, has been synthesized and characterized by using 1H, 13C NMR, and MALDI‐TOF‐MS analyses. The host–guest complex formation between 1 and halides was investigated by using 1H NMR spectroscopy in [D6]DMSO. The triazole, benzyl, and phenylene proton signals were shifted upfield by the addition of halides in the form of tetrabutylammonium salts, which implies that the triazole protons in 1 are allocated very closely to the porphyrin ring and are directed toward the binding pocket over the porphyrin ring during the formation of hydrogen bonds. The UV/Vis absorption spectra showed that both the Soret and Q band absorptions of 1 underwent a strong redshift due to the addition of halides. Compound 1 exhibited surprisingly strong binding affinities for the halides, where the association constants for Cl−, Br−, and I− binding were estimated to be larger than 108, 1.79×107, and 1.84×105 M−1, respectively. The UV/Vis absorption changes and the result of competitive titration using 4‐tert‐butylpyridine indicated that the cooperative effects of axial coordination and CH⋅⋅⋅X hydrogen bond interactions resulted in the strong binding affinity of 1 to halides.
ChemInform Abstract: μ‐Oxido‐bis(pentammine Iron(III))‐chloride‐ammonia(1/8), [Fe2(μ—O)(NH3)10] Cl4·8NH3.
Authors: Fichtl Matthias B. , Scherf Lavinia M. , Baer Sebastian A. , Kraus Florian
Published: November 2011

The title compound is synthesized by reaction of FeCl3·6H2O with liquid NH3 and characterized by single crystal XRD.
ChemInform Abstract: Recovery of a Parentlike State in Ba1‐xKxFe1.86Co0.14As2 .
Authors: Zinth Veronika , Dellmann Til , Klauss Hans‐Henning , Johrendt Dirk
Published: November 2011

Samples of the title solid solution are prepared from stoichiometric mixtures of Ba, K, and Fe0.93Co0.07As (alumina crucibles, 710—790 °C; annealing at 500—600 °C).
ChemInform Abstract: Three Banana‐Shaped Arsenomolybdates Encapsulating a Hexanuclear Transition‐Metal Central Magnetic Cluster: [AsIII2FeIII5MMo22 O85(H2O)]n‐ (M: Fe3+, n = 14; M: Ni2+ and Mn2+, n = 15).
Authors: Liu Bin , Li Lili , Zhang Yanping , Ma Ying , Hu Huaiming , Xue Ganglin
Published: November 2011

The polyoxometalates (V), (VII), and (IX) crystallize in the triclinic space group P$\bar 1$ with Z = 2 (single crystal XRD).
ChemInform Abstract: Mg11Cu6Al12, a New Link in the Structural Chemistry of MgCu2‐Type Clusters.
Authors: Berns Veronica M. , Stacey Timothy E. , Sapiro Michael , Fredrickson Daniel C.
Published: November 2011

The title compound is prepared by direct reaction of the elements at 550 °C for 24 h followed by annealing at 450 °C for 165 h (for single crystals), or at 1000 °C for 5 h followed by annealing at 500 °C for 357 h (for phase pure polycrystalline samples).
ChemInform Abstract: Asymmetric Binary Acid Catalysis: A Regioselectivity Switch Between Enantioselective 1,2‐ and 1,4‐Addition Through Different Counteranions of InIII.
Authors: Lv Jian , Zhang Long , Zhou Yueming , Nie Zongxiu , Luo Sanzhong , Cheng Jin‐Pei
Published: November 2011

Swapping the anions of an indium Lewis acid leads to a remarkable regioselectivity switch between asymmetric 1,2‐ and 1,4‐addition reactions of N‐protected indoles (II) and β,γ‐unsaturated α‐keto esters (III).
ChemInform Abstract: Highly Enantioselective Aldol Reaction of Acetone with β,γ‐Unsaturated α‐Keto Esters Promoted by Simple Chiral Primary—Tertiary Diamine Catalysts.
Authors: Peng Lin , Wang Liang‐Liang , Bai Jian‐Fei , Jia Li‐Na , Guo Yun‐Long , Luo Xi‐Ya , Wang Fei‐Ying , Xu Xiao‐Ying , Wang Li‐Xin
Published: November 2011

Under optimized conditions, acetone as well as cyclic ketones give the corresponding chiral tertiary α‐hydroxycarboxylic esters with up to 96% e.e.
ChemInform Abstract: Readily Available and Recoverable Chiral Ionic Phosphite Ligands for the Highly Enantioselective Hydrogenation of Functionalized Olefins.
Authors: Zhao Yingwei , Huang Hanmin , Shao Jianping , Xia Chungu
Published: November 2011

A new ligand bearing carbohydrate groups is successfully applied in the asymmetric hydrogenation of enamides (I), α‐dehydroamino acid esters (III), and dimethyl itaconate (V).
ChemInform Abstract: Impregnated Ruthenium on Magnetite as a Recyclable Catalyst for the N‐Alkylation of Amines, Sulfonamides, Sulfinamides, and Nitroarenes Using Alcohols as Electrophiles by a Hydrogen Autotransfer Process.
Authors: Cano Rafael , Ramon Diego J. , Yus Miguel
Published: November 2011

The system efficiently promotes the monoalkylation of anilines, nitroarenes, sulfonamides, and sulfonamides with alcohols.
ChemInform Abstract: Discovery and Mechanistic Studies of a General Air‐Promoted Metal‐Catalyzed Aerobic N‐Alkylation Reaction of Amides and Amines with Alcohols.
Authors: Liu Chuanzhi , Liao Shiheng , Li Qiang , Feng Sunlin , Yu Xiaochun , Xu Qing
Published: November 2011

The reaction allows convenient, efficient and environmentally friendly access to a wide range of secondary amines, amides, and sulfonamides.
ChemInform Abstract: Starch Immobilized Ruthenium Trichloride Catalyzed Oxidative Cyanation of Tertiary Amines with Hydrogen Peroxide.
Authors: Verma Sanny , Jain Suman L. , Sain Bir
Published: November 2011

An extended corn starch‐immobilized Ru—imidazoline ligand is successfully applied as catalyst in the oxidative cyanation of various tertiary amines.
ChemInform Abstract: Catalytic Asymmetric Synthesis of a Tertiary Benzylic Carbon Center via Phenol‐Directed Alkene Hydrogenation.
Authors: Caille Seb , Crockett Rich , Ranganathan Krishnakumar , Wang Xiang , Woo Jacqueline C. S. , Walker Shawn D.
Published: November 2011

An effective route to chiral cyclopentanes (II), useful precursors of a series of drugs, is reported.
ChemInform Abstract: Nano Indium Oxide Catalyzed Efficient Synthesis of Propargylamines via C—H and C—Cl Bond Activations.
Authors: Rahman Matiur , Bagdi Avik Kr. , Majee Adinath , Hajra Alakananda
Published: November 2011

Propargylamines are easily synthesized via a three‐component reaction.
ChemInform Abstract: The Ru‐Catalyzed Enantioselective Preparation of Chiral Halohydrins and Their Application in the Synthesis of (R)‐Clorprenaline and (S)‐Sotalol.
Authors: Lu Chuanjun , Luo Zonghua , Huang Ling , Li Xingshu
Published: November 2011

The target compounds are synthesized by a new asymmetric transfer hydrogenation of halo‐substituted aryl methyl ketones.
ChemInform Abstract: Palladium‐Catalyzed Carbon‐Monoxide‐Free Aminocarbonylation of Aryl Halides Using N‐Substituted Formamides as an Amide Source.
Authors: Sawant Dinesh N. , Wagh Yoghesh S. , Bhatte Kushal D. , Bhanage Bhalchandra M.
Published: November 2011

It is found that POCl3 in combination with Pd(OAc)2 and Xantphos efficiently promotes the coupling of aryl iodides and bromides with formamides giving a wide range of aromatic amides.
ChemInform Abstract: Catalytic Enantioselective Addition of Sodium Bisulfite to Chalcones.
Authors: Moccia Maria , Fini Francesco , Scagnetti Michela , Adamo Mauro F. A.
Published: November 2011

Asymmetric addition of sodium bisulfite towards chalcone derivatives (I) is efficiently catalyzed by a cinchona alkaloid‐derived bifunctional amine—thiourea catalyst.
ChemInform Abstract: Palladium‐Catalyzed Benzoin‐Mediated Redox Process Leading to Biaryls from Aryl Halides.
Authors: Park Bo Ram , Kim Ko Hoon , Kim Taek Hyeon , Kim Jae Nyoung
Published: November 2011

The procedure is successfully applied to the coupling of uracil derivative (VI).
ChemInform Abstract: Synthesis and Antitubercular Evaluation of Amidoalkyl Dibenzofuranols and 1H‐Benzo[2,3]benzofuro[4,5‐e][1,3]oxazin‐3(2H)‐ones.
Authors: Kantevari Srinivas , Yempala Thirumal , Yogeeswari Perumal , Sriram Dharmarajan , Sridhar Balasubramanian
Published: November 2011

The compounds (IV) and (V) are screened for their in vitro antimycobacterial activity against M.