bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of proton‐exchange hybrid membranes
Authors: Linares Amelia , Acosta José Luis 
Published: March 2005

AbstractTwo types of composite were prepared, based on a thermoplastic polymer, polyvinylidene fluoride (PVDF), and an elastomer, ethylene‐propylene‐diene terpolymer (EPDM), respectively. We obtained both series by addition of an inorganic proton‐conducting antimonic acid derivative (HSb) and polystyrene crosslinked with a small percentage of divinylbenzene (PS‐co‐DVB). From these composites, membranes were obtained and subjected to a heterogeneous‐phase sulfonation reaction with chlorosulfonic acid. All experimental materials were characterized from a morphological and electrical point of view, by means of techniques such as differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), non‐isothermal crystallization and complex impedance analysis. Copyright © 2005 Society of Chemical Industry
Ambient‐temperature copper‐catalyzed atom transfer radical polymerization of methacrylates in ethylene glycol solvents
Authors: Kimani Solomon M. , Moratti Stephen C. 
Published: March 2005

AbstractThe use of ethylene glycol solvents in the room‐temperature atom transfer radical polymerization (ATRP) of various hydrophobic and hydrophilic methacrylates is demonstrated. Unlike many of the very polar solvents described in the literature for room‐temperature ATRP, these solvents have good solvency for a wide range of polymers and monomers and are cheap and relatively nontoxic. Ethylene glycols with one hydroxyl and one methoxy group, such as tri(ethylene glycol) monomethyl ether (TEGMME), provide optimal results. The polymerization of methyl methacrylate in TEGMME with CuBr/N,N,N′N′,N″‐pentamethyldiethylenetriamine as the catalyst requires the addition of CuCl2 at the beginning of the reaction to produce well‐controlled polymerizations. This leads to polymers with predictable molecular weights and relatively narrow polydispersities. Polymerization in solvents that are fully methoxy‐capped terminate prematurely because of catalyst precipitation. The electrochemical behavior of copper complexes in selected solvents is examined to determine why these solvents provide good rates at room temperature. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1588–1598, 2005
Effect of alkylaluminum on ethylene polymerization catalyzed by 2,6‐bis(imino)pyridyl complexes of Fe(II)
Authors: Wang Qi , Li Lidong , Fan Zhiqiang 
Published: March 2005

AbstractIn the presence of tetraethylaluminoxane (TEAO), iron complexes were used to catalyze ethylene polymerizations with extremely high activities and generally produced polyethylene with a bimodal molecular weight distribution (MWD). This bimodal MWD of polyethylene was mainly derived from residual triethylaluminum in TEAO and was produced through a mechanism of chain transfer to aluminum. Ethylaluminoxane and tetraisobutylaluminoxane also were used to polymerize ethylene with high activities in the presence of iron complexes, and only polyethylene with a unimodal MWD was produced. The ratio of the rate constant of chain transfer to aluminum (ktrA) to the rate constant of chain propagation (kp) was determined to be 0.12 for {[ArNC(Me)]2C5H3N}FeCl2 when Ar was 2,6‐diisopropylphenyl (1) and 2.48 for {[ArNC(Me)]2C5H3N}FeCl2 when Ar was 2,6‐dimethylphenyl (2); these values are far larger than those for metallocene‐based catalysts. This explains why an iron complex usually produces polyethylene with a broader MWD than metallocene‐based catalysts. Additionally, it can be concluded from the great difference between 1 and 2 with respect to ktrA/kp that an iron complex with less congested aryl substituents is subjected to chain transfer to aluminum. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1599–1606, 2005
Donor–acceptor‐based poly(toluidine‐co‐chloroaniline)s: Synthesis and characterization
Authors: Savitha P. , Sathyanarayana D. N. 
Published: March 2005

AbstractA series of poly(o‐/m‐toluidine‐co‐o‐/m‐chloroaniline) copolymers of different compositions were synthesized by an emulsion method with ammonium persulfate as the oxidant. The conductivity of the copolymers was two to five orders of magnitude higher than that of the homopolymers poly(o‐toluidine) and poly(m‐chloroaniline). Among the copolymers, the copolymer of o‐toluidine and m‐chloroaniline exhibited a maximum conductivity of 0.14 S cm−1. The conductivity of these copolymers was also higher than that of poly(aniline‐co‐chloroaniline). The properties of the copolymers were greatly influenced by the positions of the substituents and the concentrations of the individual monomers in the feed. All the copolymers were completely soluble in polar solvents such as dimethyl sulfoxide and showed higher heat stability as the chloroaniline concentration increased. These effects could be interpreted in terms of extensive hydrogen bonding and interchain linking and, therefore, higher electron delocalization in these copolymers due to the presence of electron‐rich toluidine rings adjacent to electron‐deficient chloroaniline. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1579–1587, 2005
Self‐assembly of oligo(p‐phenylenevinylene)‐block‐poly(ethylene oxide) in polar media and solubilization of an oligo(p‐phenylenevinylene) homooligomer inside the assembly
Authors: Mori Takeshi , Watanabe Takushi , Minagawa Keiji , Tanaka Masami 
Published: March 2005

AbstractRod–coil amphiphilic diblock copolymers, consisting of oligo(p‐phenylenevinylene) (OPV) as a rod and hydrophobic block and poly(ethylene oxide) (PEO) as a coil and hydrophilic block, were synthesized by a convergent method. The aggregation behavior of the block copolymers in a selective solvent (tetrahydrofuran/H2O) was probed with the absorption and emission of the OPV block. With increasing H2O concentration, the absorption maximum was blueshifted, the emission from the molecularly dissolved OPV decreased, and that from the aggregated OPV increased. This indicated that the OPV blocks formed H‐type aggregates in which the OPV blocks aligned in a parallel orientation with one another. The transmission electron microscopy observation revealed that the block copolymers with PEO weight fractions of 41 and 62 wt % formed cylindrical aggregates with a diameter of 6–8 nm and a length of several hundreds nanometers, whereas the block copolymer with 79 wt % PEO formed distorted spherical aggregates with an average diameter of 13 nm. Furthermore, the solubilization of an OPV homooligomer with the block copolymer was studied. When the total polymer concentration was less than 0.1 wt %, the block copolymer solubilized OPV with a 50 mol % concentration. The structure of the aggregates was a cylinder with a relatively large diameter distribution. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1569–1578, 2005
Unusual inorganic phase formation in ultraviolet‐curable organic–inorganic hybrid films
Authors: Zong Zhengang , Soucek Mark D. , Xue Chenchen 
Published: March 2005

AbstractInorganic–organic hybrid materials were prepared with a cycloaliphatic epoxide adduct of linseed oil with tetraethylorthosilicate (TEOS) oligomers via a cationic UV‐curing process. The TEOS oligomers were prepared in the presence of water and ethanol with hydrochloric acid as a catalyst. The TEOS oligomers were characterized with 1H and 29Si NMR and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Hybrid films were cured, and the dynamic mechanical and thermal properties of the hybrid films were evaluated as a function of the TEOS oligomer content. The morphology of the hybrid films was examined with atomic force microscopy, transmission electron microscopy, and small‐angle light scattering. The microscopy and dynamic mechanical data indicated that the hybrid films were heterogeneous materials with various inorganic particle sizes dispersed within the organic matrix. In addition, 29Si solid‐state NMR spectroscopy was used to investigate the coupling between the silicate region and organic regions. A schematic model is proposed to address structural features of hybrid materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1607–1623, 2005
Diffusion, elasticity, and shear flow in self‐assembled block copolymers: A molecular dynamics study
Authors: Fraser Blair , Denniston Colin , Müser Martin H. 
Published: March 2005

AbstractSelf‐assembled ordered structures composed of block copolymers are simulated by molecular dynamics under stress‐free conditions and under shear. We address several methodological points. The system must be allowed to adjust its size to accommodate natural periods of self‐assembled structures. In addition, these structures need to be capable of rotating freely under shear. An examination of the diffusion of polymer molecules in the lamellar phase reveals subdiffusion along translationally invariant directions between the ballistic and diffusive regime. The diffused distancedincreases with timetasd∝t1/3. We also examine the possibility of mapping structures such as cylindrical phases onto particle–field types of models. Using measurements of the wavevector‐dependent dynamic matrix, we show that this cannot be done with only two‐body potentials. We then examine the molecular origin of shear alignment of lamellar phases. Lamellae oriented parallel to the shear direction become unstable at high shear rates when the major axis of the tensor of gyration of individual polymers forms an average angle of 45° with the lamellae. This instability can be understood in analogy to similar transitions in liquid crystals. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 970–982, 2005
The psychological impact of mammographic screening on women with a family history of breast cancer—a systematic review
Authors: Watson Eila K. , Henderson Bethan J. , Brett Joanne , Bankhead Clare , Austoker Joan 
Published: March 2005

AbstractThis systematic review aims to assess the psychological impact of mammographic screening on women with a family history of breast cancer. Women with a family history, and hence increased risk, of breast cancer are known to experience higher levels of anxiety about cancer. They are also often offered screening from an earlier age. The psychological consequences of screening are therefore of particular importance for this group of women. A comprehensive search of 4 electronic databases was conducted from 1982 to 2003, combining sets of terms relating to (1) breast screening or mammography (breast screen*; mammogra*), (2) psychological impact (adverse effects; anxi*; distress; nervous; psych*, psychological consequences; stress; worry) and (3) family history. Reference lists from relevant papers were examined for additional papers. The review identified seven papers from four countries. Overall, the findings indicate that, similar to women in the general population, most women with a family history do not appear to experience high levels of anxiety associated with mammographic screening. Although women who are recalled for further tests do experience increased anxiety the levels appear to be no greater than for women without a family history. We conclude that further research on this topic is required—this should include studies designed specifically to consider both the negative and positive impact of mammographic screening on women with a family history, using validated measures of anxiety and worry in combination with qualitative research. Copyright © 2005 John Wiley & Sons, Ltd.
Differences in quality of life between non‐Hodgkin's lymphoma survivors meeting and not meeting public health exercise guidelines
Authors: Vallance Jeffrey K.H. , Courneya Kerry S. , Jones Lee W. , Reiman Tony 
Published: March 2005

AbstractThe primary purpose of this study was to examine differences in quality of life (QoL) between non‐Hodgkin's lymphoma (NHL) survivors meeting and not meeting public health exercise guidelines. A secondary purpose was to examine exercise behavior changes across three distinct cancer‐related time periods (i.e. prediagnosis, on treatment and off treatment). Using a retrospective survey design, 438 NHL survivors residing in Alberta, Canada completed a mailed questionnaire that assessed self‐reported exercise prediagnosis, on treatment and off treatment, and current QoL. Descriptive analyses indicated that 33.8, 6.5 and 23.7% of NHL survivors met public health exercise guidelines during prediagnosis, on treatment, and off treatment time periods, respectively. Multivariate analyses of variance indicated that NHL survivors meeting public health exercise guidelines during postdiagnosis time periods had higher current QoL scores than NHL survivors not meeting guidelines. QoL difference scores between the two groups met proposed standards for clinically important differences. Multivariate analyses also indicated significant differences in exercise behavior across the three cancer‐related time periods (all p's<0.01). These analyses were unchanged after statistically controlling for important medical and demographic variables. The results of this study provide evidence that NHL survivors meeting public health exercise guidelines on and off treatment reported higher current QoL than those survivors not meeting guidelines. These findings corroborate research examining exercise behavior in other cancer survivor groups and provide preliminary data to support a randomized controlled trial on exercise and QoL in this population. Copyright © 2005 John Wiley & Sons, Ltd.
A qualitative study of work and work return in cancer survivors
Authors: Main Deborah S. , Nowels Carolyn T. , Cavender Tia A. , Etschmaier Martine , Steiner John F. 
Published: March 2005

AbstractFew studies have examined the impact of cancer on the survivor's quality of work life. The purpose of this qualitative study is to describe the work experiences among a diverse group of cancer survivors and to explore factors influencing decisions about work after cancer diagnosis and treatment. We interviewed 28 participants with a broad range of socioeconomic backgrounds and primary cancer sites. Qualitative results indicate that after learning about their cancer diagnosis, participants had diverse and complex patterns of work return and work change, and experienced a variety of factors that influenced post‐cancer decisions. Experiences at work after cancer also varied in relation to how others responded, changes in productivity, effects of cancer and treatment on work, and feelings about work. Most respondents received little guidance from their physicians about work, and many participants described their cancer as impacting their priority of work relative to other aspects of their lives. Our findings reinforce the complexity of measuring employment outcomes and the range of adaptations made to improve the quality of work life. Additional research is needed to identify prognostic factors that can guide clinical or workplace efforts to restore cancer survivors to their desired level of work function and economic productivity. Copyright © 2005 John Wiley & Sons, Ltd.
Transmission Fluctuation Spectrometry in Concentrated Suspensions Part One: Effects of the Monolayer Structure
Authors: Shen Jianqi , Riebel Ulrich 
Published: March 2005

AbstractThe theory of transmission fluctuation spectrometry (TFS) was recently developed for particle size analysis in dilute flowing particle suspensions, whereby the statistical transmission fluctuations are used to extract the particle size distribution and particle concentration.
Transmission Fluctuation Spectrometry in Concentrated Suspensions Part Two: Particle Overlapping
Authors: Riebel Ulrich , Shen Jianqi 
Published: March 2005

AbstractTransmission fluctuations measured on a flowing suspension of particles with a high spatial and temporal resolution can be used to measure the particle size distribution and particle concentration. The theory of transmission fluctuation spectrometry (TFS) was recently developed, whereby the statistical behavior of the entire suspension is described on the basis of a single monolayer, in combination with a layer model describing the suspension as a series of independent monolayers. As the monolayers are assumed to be statistically independent from each other, the transmission through the 3‐dimensional suspension is modeled as the product of transmissions through the monolayers.
Simulation of Aggregation with Applications to Soot Laden Lubricating Fluids
Authors: Zeidan Michael , Jia Xiaodong , Williams Richard A. , Wedlock David J. 
Published: March 2005

AbstractThe requirement for heavy duty diesel engines to reduce the level of NOx emissions has resulted in higher soot loading of engine lubricants due to fuel injection retardation and exhaust gas re‐circulation. An improved understanding of the process of soot aggregation and aggregate morphology is therefore required to provide an insight into the consequences of soot‐laden lubricants. These include the effects of dispersant architecture and soot loading rate on aggregate morphology. A 2D and 3D study using a semi‐quantitative random walk based simulation model into the evolution of simulated fractal‐like colloidal aggregates has been carried out and applied to address these issues. The effects of variable soot loading rates, which are engine dependent, are reported. The role of different interaction forces which are, among other things, engine temperature and lubricant formulation dependent is explored. Differences between the simulations run under the same conditions but in different dimensions are highlighted and their implications discussed. The data indicate that a correlation can be established between inter‐particle forces (represented via a sticking probability) and both aggregate morphology (represented by fractal dimension) and aggregate dispersancy and the degree of dispersion of those aggregates (measured by the mean empty space parameter). Significantly, a strong relationship was found between soot‐loading rate and aggregate morphology, with higher loading rates leading to both a much lower fractal dimension and a higher degree of aggregate dispersion, which in turn would lead to a higher lubricant viscosity.
Variations in Grain Size Analysis with a Time‐of‐Transition Laser Sizer (Galai CIS‐50) using a Gravitational Flow System
Authors: Bohling Björn 
Published: March 2005

AbstractThis study deals with grain size analysis with a Laser Sizer Galai CIS‐50. This device utilizes the time‐of‐transition method and is equipped with a module for measurements in the range 0.5 to 150 μm along with a gravitational flow system. Experiments were conducted using natural marine sediments. The aim was to determine possible explanations for discrepancies in the measured results that occurred between different operators of the Galai CIS‐50. These discrepancies may be due to differences in the technique of inserting a sub‐sample into the measurement system. Furthermore, the influence of the sample concentration and the flow velocity in the device's liquid flow cell is considered, since these factors can act as potential sources of inaccuracies and errors in the experimental setup. Strong variations in the results occurred, which were mainly due to problems in the detection of particles >20 μm. In the range>20 μm gaps appeared in the registration of the size distribution. An improvement in reproducibility was achieved by using a pipette instead of a beaker for the insertion step. Nevertheless, the standard deviation for mean grain sizes of natural marine sediments obtained with the Galai CIS‐50 is still about 20%.
Categorisation of Particulate Emissions from a Fluidised Catalytic Cracking Unit
Authors: Whitcombe Josh M. , Agranovski Igor E. , Braddock Roger D. 
Published: March 2005

AbstractFluidized Catalytic Cracker Units (FCCU) are used in the oil refining industry to convert long chained hydrocarbons into shorter ones. At normal operations there is little concern regarding catalyst particle emission into the atmosphere from these devices. However, when the unit is started, higher than normal emission rates are common. FCCU stack emissions were tested and categorized in terms of metal composition and were compared with the operational conditions experienced under start up conditions. It was found that excessive emissions can be explained due to fluctuations in cyclone performance, the production of fine particles via attrition processes and the thermal fracture of particles. In addition to particle emissions, levels of emitted metals also fluctuate during the start up period, with the highest levels being experienced at the moment oil is re‐fed into the unit. The current paper summarises stack testing results as well as the operational conditions in order to identify the key causes of start up emissions and provide recommendations to reduce and manage particle emissions from refineries.
Fast scanning tunnelling microscopy as a tool to understand changes on metal surfaces: from nanostructures to single atoms
Authors: Morgenstern Karina 
Published: March 2005

AbstractMorphological changes on surfaces have been followed in real time by scanning tunnelling microscopy on the time scale of seconds to days. This “on‐site on‐time” mode has been employed for the observation of decay, motion, coalescence, and shape fluctuations of islands on the low‐indexed faces of Ag, Cu, Pt, and Au. For island changes under well‐defined conditions, well‐established theories are adapted to identify atomic processes and extract quantitative information on diffusion parameters important for growth and stability of nanostructures, such as energies and prefactors. Extension of the “on‐site on‐time” approach to atoms, dimers, etc. and to dislocations is outlined. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Feature Article: Fast scanning tunnelling microscopy as a tool to understand changes on metal surfaces: from nanostructures to single atoms
Authors: Morgenstern Karina 
Published: March 2005

AbstractThe Feature Article [1] describes how structural changes in metallic nanostructures can be followed with fast scanning tunneling microscopy (STM). The title page shows the same spot of a Ag(111) surface at room temperature, imaged with STM approximately one hour apart. Intrinsic changes to prepared nano‐structures are marked as Brownian motion of vacancy islands (rectangle), coalescence of two vacancy islands (hexagon), and decay of an adatom island (circle).Karina Morgenstern is now professor at the University of Hannover. Her research is placed within the field of nanoscience and is in particular devoted to thermally activated processes of metallic nanostructures, electronically activated reactions of molecules on metallic surfaces, and water–metal interactions.The present issue of physica status solidi (b) also contains the article ‘Apperance of copper d9 defect centres in wide‐gap CdSe nanoparticles: A high‐fequency EPR study’ by N. R. J. Poolton et al. as Editor's Choice [2] as well as several papers on electrical and nonlinear optical properties from the European Conference on Organised Films (ECOF 2004) chaired by José Antonio de Saja, Valladolid.
Analgesic and anti‐inflammatory activity of the ethanolic extract from Spiranthera odoratissima A. St. Hillaire (Manacá) roots
Authors: Matos L. G. , Pontes I. S. , Tresvenzol L. M. F. , Paula J. R. , Costa E. A. 
Published: March 2005

AbstractAcetic acid‐induced abdominal writhing, the tail flick test and carrageenan‐induced peritonitis were used to study the analgesic and anti‐inflammatory activity of the crude ethanolic extract from Spiranthera odoratissima roots. Pentobarbital‐induced sleeping time was used to study the central depressant effect of the extract. The ethanolic extract caused a dose dependent inhibition of acetic acid‐induced abdominal writhing and leukocyte migration, and produced a significant, dose‐related increase in the duration of sleep. The results suggest that Spiranthera odoratissima roots contain compounds with anti‐inflammatory and central depressant actions. Copyright © 2004 John Wiley & Sons, Ltd.