bluuebunny/crossref_metadata_2025 huggingface dataset:
Fibre reinforcement material in solid construction / Faserverbundbewehrung im Massivbau
Authors: Venter Werner
Published: June 2014

Glass‐fibre reinforcement is enjoying increasing popularity in solid construction and masonry buildings. The first approvals for the material have been obtained in Europe. It is possible to carry out the structural design of components with glass‐fibre reinforcement based on EC 2 and EC 6 in combination with the fib Technical Bulletin.

The rapid development of fibre‐reinforced plastics (FRPs) offers completely new alternatives to conventional reinforcement steel which are significantly more durable, do not have any metal properties and feature a significantly better energy footprint.
Assessment of Dryfix masonry adhesive in terms of building physics compared to conventional bonding / Betrachtung der bauphysikalischen Gleichwertigkeit des Dryfix‐Planziegel‐Klebers
Authors: Lehmden Alexander
Published: June 2014

Dryfix masonry adhesive is celebrating its 10‐year anniversary in 2014. The Dryfix system has been introduced to and approved in ten European countries: Austria, Germany, France, Poland, Italy, Slovenia, Croatia, Hungary, Slovakia and the Czech Republic. Every year, 25.000 housing units throughout Europe are built with Dryfix.

In addition to the mechanical properties of the polyurethane adhesive, the properties of building physics such as thermal insulation, fire resistance and sound insulation were investigated in connection with brick masonry. On the basis of sound and fire tests with brick masonry walls, it was possible to demonstrate that the material is equivalent to conventional materials. In addition, the thermal insulation of brick masonry is improved because of the joint‐less bond of the blocks and the omission of the mortar joint which acts as a thermal bridge. This report is intended to summarise the status of the building physics assessment and optimisation achieved in order to provide secure data for the practical application of Dryfix masonry adhesive.
Hybrid testing of masonry structures subjected to seismic loading / Hybride Versuche an Mauerwerkskonstruktionen unter Erdbebenbeanspruchung
Authors: Schermer Detleff
Published: June 2014

The combination of experiments and numeric description in a test makes it possible to realistically investigate almost any type of system subjected to dynamic loading without requiring the extremely expensive device of a shaking table. With the numeric approach it is possible to examine the behaviour of even very large and complex structures, thus reducing the experimental investigations to the essential part of the system – for example, bracing masonry walls. This test method has proved to be very helpful, particularly for the investigation of seismic loading, and it allows the synchronous examination of several force and displacement variables (horizontal, vertical, rotational). A new laboratory is presented for the investigation of full‐scale building structures up to three storeys high.
Background of the values for compressive strength of masonry acc. to EC 6 – evaluation of data / Hintergrund der Druckfestigkeitswerte für Mauerwerk im Eurocode 6 – Datenauswertung
Authors: Jäger Wolfram , Pech Anton
Published: June 2014

In accordance with EN 1996‐1‐1 [1] the compressive strength of masonry is determined with the help of power functions. For this purpose, the standard includes values in Table 3.3 which were established by evaluating available test values in 2001/2002. In this article the theoretical background for the evaluation of the database is explained and a practical procedure is introduced which was applied at the time in order to be able to list values in EN 1996‐1‐1.

This article does not discuss individual combinations of masonry units and mortar. It only presents in summary the methodology and the underlying mathematical basis. The purpose of this contribution is to provide the countries in need of specific evaluations support for the anticipated update and adaptation of EC 6.
Qualitative analysis of seized cocaine samples using desorption electrospray ionization‐ mass spectrometry (DESI‐MS)
Authors: Stojanovska Natasha , Tahtouh Mark , Kelly Tamsin , Beavis Alison , Fu Shanlin
Published: June 2014

Desorption electrospray ionization ‐ mass spectrometry (DESI‐MS) is a useful technique for the qualitative analysis of compounds found in seized drug material. In this study, DESI‐MS was utilized in the screening analysis of illicit cocaine samples. The technique was also applied to the geographical origin determination of these samples. The limit of detection was determined to be 24.3 µg (or 3.47 µg/mm2) and the analysis time was less than 1 minute per sample. The intra‐day and inter‐day precision for the detection of cocaine was 11 % and 42 %, respectively; therefore the quantitative data provided by DESI‐MS was limited in its use for accurate determination of cocaine concentration in a sample. Using the quadrupole time‐of‐flight (QTOF) mass spectrometer, the presence of cocaine and impurities detected were confirmed by accurate tandem MS data. The qualitative chemical profiles obtained using DESI‐MS were compared to two popular analysis techniques, GC‐MS and LC‐MS. The effects of a range of adulterants including caffeine, procaine, levamisole, lignocaine, paracetamol, and atropine on the detectability of cocaine were also investigated. It was found that the addition of these adulterants in a cocaine sample did not prevent the detection of the analyte itself (there was slight enhancement in some samples), which was useful in drug detection. The detection of truxillines in the seized samples by DESI‐MS aided in the preliminary determination of geographical origin, i.e., Bolivian, Peruvian or Colombian leaf origin. The application of DESI‐MS to the qualitative analysis and screening of seized cocaine samples demonstrates the potential and applicability of the technique to the fast chemical profiling of illicit samples. Copyright © 2014 John Wiley & Sons, Ltd.
A Single‐Phase Emission‐Tunable Ca5(PO4)3F:Eu2+,Mn2+ Phosphor with Efficient Energy Transfer for White LEDs
Authors: Wanjun Tang , Fen Zhang
Published: June 2014

Eu2+/Mn2+‐co‐doped white‐emitting Ca5(PO4)3F phosphors have been synthesized by a combustion‐assisted synthesis method. The PXRD patterns confirmed the single‐phase fluorapatite crystal structure for all the samples independently of their substitution level. Their luminescence properties reveal that the developed phosphors can efficiently convert UV light in a broad range from 250 to 420 nm into tunable white emission. Based on the luminescence spectra and fluorescence decay curves, we can confirm that energy transfer from the Eu2+ to Mn2+ ions takes place in the Ca5(PO4)3F:Eu2+,Mn2+ phosphors, and that the energy‐transfer efficiency increases with increasing Mn2+ content. The emission colors of the obtained phosphors can be tuned from blue to white and eventually to yellow by controlling the doping content of the Eu2+ and Mn2+ ions. These results suggest that these phosphors are potential single‐component white‐light phosphors for n‐UV‐pumped white LEDs.
Self‐Organization of Anderson‐Based Amphiphiles
Authors: Lin Chang‐Gen , Chen Wei , Song Yu‐Fei
Published: June 2014

Amphiphilic molecules with polyoxometalate head groups have attracted much attention in the last decade. In this paper, we report the successful synthesis and full characterization of three new Anderson‐based amphiphiles, 3a, 3b, and 3c, which were formed by covalently attaching different numbers of hydrophobic alkyl chains onto both sides of Anderson clusters. The self‐organization process has been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy‐dispersive X‐ray (EDX) spectroscopy and dynamic light scattering (DLS) in a series of acetonitrile/water mixtures. The experimental results have shown intriguing morphologies along with the change of solvent polarity and structural conformation, which provides us with a better understanding of the mechanism of self‐organization and the relationship between the self‐organization morphology and the molecular structures.
Facile in situ Syntheses of Highly Water‐Stable Acidic Sulfonated Mesoporous Silica without Surfactant or Template
Authors: Hasan Zubair , Jhung Sung Hwa
Published: June 2014

A new simple method to prepare acidic mesoporous sulfonated silica in situ without any surfactant is reported. The prepared catalysts were characterized by XRD, nitrogen adsorption, thermogravimetric analysis (TGA), and elemental analysis. The concentration of –SO3H groups was measured by titration, and FTIR was applied to confirm the successful incorporation of the strong acid sites. The in situ sulfonated silica (ISS) has a large surface area with a narrow range of mesoporosity and good thermal stability. Moreover, the preparation method has the advantage of easy control of the acid concentration and versatile synthesis. The ISS was used in catalytic hydrolysis and showed remarkable reusability even under very harsh conditions. The butylation of phenol was conducted over ISS to utilize the mesoporosity of the catalysts. Finally, the ISS catalysts might be used in various acid catalyses owing to the advantages of their simple/inexpensive preparation, reusability, and mesoporosity.
Hydrodynamic constraints and storm wave characteristics on a sub‐horizontal shore platform
Authors: Ogawa Hiroki , Dickson Mark E. , Kench Paul S.
Published: June 2014

Few studies of wave processes on shore platforms have addressed the hydrodynamic thresholds that control wave transformation and energy dissipation, especially under storm conditions. We present results of a field experiment conducted during a storm on a sub‐horizontal shore platform on the east coast of Auckland, New Zealand. Small (<0.5 m) locally generated waves typically occur at the field site, whereas during the experiment the offshore wave height reached 2.3 m. Our results illustrate the important control that platform morphology has on wave characteristics. At the seaward edge of the platform a scarp abruptly descends beneath low tide level. Wave height immediately seaward of the platform was controlled by the incident conditions, but near the cliff toe wave height on the platform was independent of incident conditions. Results show that a depth threshold at the seaward platform edge > 2.5 times the gravity wave height (0.05–0.33 Hz) is necessary for waves to propagate onto the platform without breaking. On the platform surface the wave height is a direct function of water depth, with limiting maximum wave height to water depth ratios of 0.55 and 0.78 at the centre of the platform and cliff toe, respectively. A relative ‘platform edge submergence’ (water depth/water height ratio) threshold of 1.1 is identified, below which infragravity (<0.05 Hz) wave energy dominates the platform energy spectra, and above which gravity waves are dominant. Infragravity wave height transformation across the platform is governed by the relative platform edge submergence. Finally, the paper describes the first observations of wave setup on a shore platform. During the peak of the storm, wave setup on the platform at low tide (0.21 m) is consistent with measurements from planar sandy beaches, but at higher tidal stages the ratio between incident wave height and maximum setup was lower than expected. Copyright © 2014 John Wiley & Sons, Ltd.
Stress response of Pseudomonas species to silver nanoparticles at the molecular level
Authors: Soni Deepika , Bafana Amit , Gandhi Deepa , Sivanesan Saravanadevi , Pandey Ram Avatar
Published: June 2014

In recent years, silver nanoparticles (AgNPs) have been shown to possess broad antibacterial activity. The present study investigated the cytotoxicity of AgNPs to a common soil bacterium, Pseudomonas sp. The molecular mechanism involved in its stress response to AgNPs was also studied. The minimum inhibitory concentration (MIC) of AgNPs was found to be 0.2 mg/L. At a sublethal concentration of 0.1 mg/L AgNPs, the protein expression profile of Pseudomonas showed overexpression of stress proteins such as ribosomal proteins S2 and L9, alkyl hydroperoxide reductase/thiol-specific antioxidant (AhpC/TSA) family protein, and keto-hydroxyglutarate aldolase (KHGA). The upregulation of these proteins was further confirmed by quantitative polymerase chain reaction. The results showed increased expression of ribosomal protein S2, KHGA, AhpC/TSA, and ribosomal protein L9 by 1.09-, 3.41-, 1.52-, and 1.56-fold, respectively (p < 0.05), after AgNP exposure compared with control. The present study clearly demonstrates that AgNPs are toxic to soil bacteria and induce oxidative and metabolic stress. Environ Toxicol Chem 2014; 33:2126–2132. © 2014 SETAC
Impact of particle size and light exposure on the effects of TiO2 nanoparticles on Caenorhabditis elegans
Authors: Angelstorf Judith S. , Ahlf Wolfgang , von der Kammer Frank , Heise Susanne
Published: June 2014

The increasing use of engineered nanoparticles in industrial and consumer products leads to a release of the anthropogenic contaminants to the aquatic environment. To obtain a better understanding of the environmental effects of these particles, the nematode Caenorhabditis elegans was used to investigate the organism-level effects and in vivo molecular responses. Toxicity of bulk-scale (∼160 nm) and nanoscale (21 nm) titanium dioxide (TiO2) was tested under dark and light conditions, following ISO 10872. The expression of sod-3, a mitochondrial superoxide dismutase, was quantified as an indicator for oxidative stress induced by the photocatalytically active material. Particle sizes were estimated using dynamic light scattering and scanning electron microscopy. Although both materials agglomerated to a comparable secondary particle size of 300 nm to 1500 nm and were ingested into the intestine, only nanoscale-TiO2 significantly inhibited reproduction (lowest-observed-effect-concentration [LOEC]: 10 mg/L). Light exposure induced the production of reactive oxygen species (ROS) by nanoscale-TiO2 and increased toxicity of the nanomaterial from a median effect concentration of more than 100 mg/L to 53 mg/L. No evidence was found for inner cellular photocatalytic activity of nanoscale-TiO2. Therefore, oxidative damage of the membranes of intestinal cells is suggested as a potential mode of action. Results highlight the importance of primary particle size and environmental parameters on the toxicity of TiO2. Environ Toxicol Chem 2014;33:2288–2296. © 2014 SETAC
Determination of Oxygen‐Reduction‐Reaction Active Sites of Tantalum Oxide‐based Cathodes Used for Polymer Electrolyte Fuel Cells
Authors: Asada T. , Arao M. , Kubobuchi K. , Mogi M. , Takahashi Y. , Matsumoto M. , Ishihara A. , Ota K. , Imai H.
Published: June 2014

We report the results of high‐resolution transmission electron‐micrograph (TEM) observation, electron diffraction, and neutron diffraction (ND) measurements, which are sensitive to oxygen‐vacancies, for Ta‐oxide‐based oxygen‐reduction electrocatalysts used for polymer electrolyte fuel cells (PEFCs). Both TEM and ND results indicate that highly active tantalum oxide (Ta2O5) phase have an incommensurate long‐period structure with oxygen vacancies in the oxides, forming three‐dimensionally ordered region in the crystal. Such corrective oxygen‐vacancies might be effective to create better electronic or surface structural features for oxygen reduction reaction.
Electrochemical Impedance Modeling of a Solid Oxide Fuel Cell Anode
Authors: Mohammadi R. , Søgaard M. , Ramos T. , Ghassemi M. , Mogensen M. B.
Published: June 2014

A simulation package for the impedance response of SOFC anodes is presented here. The model couples the gas transport in gas channels and within a porous electrode with the electrochemical kinetics. The gas phase mass transport is modeled using mass conservation equations. A transmission line model (TLM), which is suitably modified to account for the electrode microstructural details, is used for modeling the impedance arising from the electrochemical reactions. In order to solve the system of nonlinear equations, an in‐house code based on the finite difference method was developed. Some of the model constants have been calibrated against experimental data. It is demonstrated that the simulation tool is capable of predicting the impedance response of an experimental data set obtained on symmetrical cells with Ni/ScYSZ SOFC anodes. A parametric study is also carried out using the developed simulation tool and the results are further discussed.
ESTIMATING HEALTH STATE UTILITY VALUES FROM DISCRETE CHOICE EXPERIMENTS—A QALY SPACE MODEL APPROACH
Authors: Gu Yuanyuan , Norman Richard , Viney Rosalie
Published: June 2014

Using discrete choice experiments (DCEs) to estimate health state utility values has become an important alternative to the conventional methods of Time Trade‐Off and Standard Gamble. Studies using DCEs have typically used the conditional logit to estimate the underlying utility function. The conditional logit is known for several limitations. In this paper, we propose two types of models based on the mixed logit: one using preference space and the other using quality‐adjusted life year (QALY) space, a concept adapted from the willingness‐to‐pay literature. These methods are applied to a dataset collected using the EQ‐5D. The results showcase the advantages of using QALY space and demonstrate that the preferred QALY space model provides lower estimates of the utility values than the conditional logit, with the divergence increasing with worsening health states. Copyright © 2014 John Wiley & Sons, Ltd.
New insight into the enhanced effect of pegylated interferon-α
Authors: Abe Hiromi , Hayes Nelson C. , Chayama Kazuaki
Published: June 2014

The use of pegylated interferon-α (pegIFN-α) has replaced unmodified recombinant IFN-α for the treatment of chronic viral hepatitis. While the superior antiviral efficacy of pegIFN-α is generally attributed to improved pharmacokinetic properties, the pharmacodynamic effects of pegIFN-α in the liver have not been studied. Here, we analyzed pegIFN-α-induced signaling and gene regulation in paired liver biopsies obtained prior to treatment and during the first week following pegIFN-α injection in 18 patients with chronic hepatitis C. Despite sustained high concentrations of pegIFN-α in serum, the Jak/STAT pathway was activated in hepatocytes only on the first day after pegIFN-α administration. Evaluation of liver biopsies revealed that pegIFN-α induces hundreds of genes that can be classified into four clusters based on different temporal expression profiles. In all clusters, gene transcription was mainly driven by IFN-stimulated gene factor 3 (ISGF3). Compared with conventional IFN-α therapy, pegIFN-α induced a broader spectrum of gene expression, including many genes involved in cellular immunity. IFN-induced secondary transcription factors did not result in additional waves of gene expression. Our data indicate that the superior antiviral efficacy of pegIFN-α is not the result of prolonged Jak/STAT pathway activation in hepatocytes, but rather is due to induction of additional genes that are involved in cellular immune responses.
Appreciating Organization Development: A Comparative Essay on Divergent Perspectives
Authors: Cummings Thomas G. , Cummings Chailin
Published: June 2014

Organization development (OD) applies social science knowledge to help organizations change and improve themselves. From its beginnings over 70 years ago in group dynamics, action research, and humanistic psychology, the field has expanded enormously to include a diversity of theories and practices aimed at developing organizations at different levels, from jobs, teams, and organizations to interorganization alliances and societal change. Along with this expansive evolution, however, has come increasing confusion and disagreement in defining the field's conceptual boundaries, change interventions, and underlying values. This raises fundamental questions about the nature and consequences of OD, which can impede the field's further progress conceptually, empirically, and practically. We clarify some of the major ambiguities and differences in the field today and suggest solutions for moving forward by comparing four pairs of divergent perspectives: (a) development versus change, (b) episodic versus continuous change, (c) planned versus emergent change, and (d) diagnostic versus dialogic OD. © 2014 Wiley Periodicals, Inc.
What Do We Really Know About Employee Engagement?
Authors: Saks Alan M. , Gruman Jamie A.
Published: June 2014

Employee engagement has become one of the most popular topics in management. In less than 10 years, there have been dozens of studies published on employee engagement as well as several meta‐analyses. However, there continue to be concerns about the meaning, measurement, and theory of employee engagement. In this article, we review these concerns as well as research in an attempt to determine what we have learned about employee engagement. We then offer a theory of employee engagement that reconciles and integrates Kahn's () theory of engagement and the Job Demands–Resources (JD‐R) model (Bakker & Demerouti, ). We conclude that there continues to be a lack of consensus on the meaning of employee engagement as well as concerns about the validity of the most popular measure of employee engagement. Furthermore, it is difficult to make causal conclusions about the antecedents and consequences of employee engagement due to a number of research limitations. Thus, there remain many unanswered questions and much more to do if we are to develop a science and theory of employee engagement.
Human Resource Development Practices and Employee Engagement: Examining the Connection With Employee Turnover Intentions
Authors: Shuck Brad , Twyford Devon , Reio Thomas G. , Shuck Angie
Published: June 2014

The relationship between how an employee perceives support for participation in human resource development (HRD) practices, engagement, and turnover intent has been underrepresented in the literature. Using social exchange theory as a guiding framework, this research sought to better understand the possible linkages of HRD practices and employee engagement to turnover intentions. An Internet‐based self‐report survey battery utilizing a four‐stage preparation method was used as the primary data collection tool. Research was conducted in the health care industry ( N = 207). Linear, simultaneous, and mediated regression analyses were used to examine the variables of interest. Results suggested that participation in HRD practices and cognitive, emotional, and behavioral engagement were negatively related to turnover intent. Mediated regression analyses indicated that engagement partially mediated the relation between HRD practices and turnover intent. The findings support the utility of supporting employee participation in HRD practices to improve employee engagement and reduce turnover intent.
Standardize or Customize: The Interactive Effects of HRM and Environment Uncertainty on MNC Subsidiary Performance
Authors: Cogin Julie A. , Williamson Ian O.
Published: June 2014

This study examines the impact of customizing (as opposed to standardizing) human resource management (HRM) practices on subsidiary performance in multinational corporations (MNCs). We examine how this relationship is influenced by environmental uncertainty. Hypotheses were tested using data from 92 subsidiaries of a large MNC operating in 27 countries. The results showed an interactive relationship between the customization of HRM practices and subsidiary environmental uncertainty on both financial (net profit) and nonfinancial (customer satisfaction) objective measures of subsidiary performance. The results of this study provide important empirical insights for researchers and practitioners into how HRM can be best configured to drive multiple performance outcomes for MNC subsidiaries. © 2014 Wiley Periodicals, Inc.
Toward the Rational Design of Conjugated Oligomers and Polymers: Systematic Study of the Substituent Effect in Oligothiophenes
Authors: Zamoshchik Natalia , Sheynin Yana , Bendikov Michael
Published: June 2014

A systematic study of substituent electronic effects on a number of oligothiophene properties was performed using well‐defined oligothiophenes of various chain lengths that were monosubstituted with classical electron‐withdrawing or ‐donating groups. The main focus was to understand how the effect of a substituent on one thiophene ring was transmitted through the other thiophene rings in the oligomer. The physical and electrochemical properties were studied by optical absorption and emission spectroscopy and by cyclic voltammetry. The experimental data were complemented with theoretical calculations of HOMOLUMO gaps, charge distribution, bond length alternations, and 13C NMR spectra. We show that substitution has a significant electronic effect on the substituted ring; however, the effect decreases strongly over conjugation. A semiquantitative evaluation of the substituent effect in a well‐defined long conjugated system was obtained for the first time using the Hammett equation.
Copper‐Catalyzed Cross‐CouplingLigand‐Free Conditions Reaction of Thiols with Aryl Iodides under
Authors: Huang Yu‐Ting , Tsai Wan‐Ting , Badsara Satpal Singh , Chan Chien‐Ching , Lee Chin‐Fa
Published: June 2014

Commercially available CuO powder is found to be a suitable catalyst for C‐S coupling reaction between aryl‐ and alkyl thiols and aryl iodides. Functional groups including halides, ketone, unprotected amine and heterocycles were tolerated by the reaction conditions employed.
Engineering Students' Intelligence Beliefs and Learning
Authors: Stump Glenda S. , Husman Jenefer , Corby Marcia
Published: June 2014

Background

Students' beliefs about their intellectual ability influence their use of learning strategies, learning effort, and response to failure or setbacks. Students with incremental views of intelligence believe that learning is possible with sufficient effort, whereas those with entity views believe that intelligence is a fixed quality and expenditure of effort reflects an insufficient amount of that quality.

Purpose

This study examined the relationship between engineering students' beliefs about intelligence and their perceived use of active learning strategies such as collaboration and knowledge‐building behaviors, self‐efficacy for learning and performance, and course grade. The study also examined the extent of entity and incremental beliefs in a sample of engineering students.

Design/Method

The correlational study analyzed data from 377 engineering students recruited from required engineering courses at a large public university. We used bivariate correlations to examine relationships between study variables and multiple regression analyses to examine predictive ability of the variables on learning strategies and course grade.

Results

Our results showed that students' intelligence beliefs were correlated with active learning strategies. Self‐efficacy, reported use of collaboration, and incremental beliefs about intelligence were predictive of students' reported use of knowledge‐building behaviors. Intelligence beliefs were not predictive of course grade.

Conclusions

Our results demonstrate the utility of these motivational beliefs for understanding university engineering students' learning efforts. Our results also suggest a need for instructors to support incremental views of intelligence among engineering students.
Movements and seasonal use of habitats by rural and urban female mottled ducks in southeast Florida
Authors: Varner Dana M. , Hepp Gary R. , Bielefeld Ronald R.
Published: June 2014

Florida will continue to undergo high rates of habitat loss, primarily the result of urbanization. In addition, invasive species are a major threat to Florida's biodiversity. The Florida mottled duck (Anas fulvigula), a bird unique to the state, is particularly vulnerable to loss of wetland habitats and hybridization with feral mallards. Because mottled ducks are more likely to encounter feral mallards in urban habitats, we trapped and radiomarked adult females in urban (n = 99) and rural (n = 146) habitats to estimate home ranges and rates of movement into and out of urban areas. We also determined habitat use in urban and rural areas during the breeding (1 Feb–31 Jul), post‐breeding (1 Aug–18 Nov), and hunting (19 Nov–31 Jan) periods and estimated seasonal habitat selection of rural female mottled ducks. Urban females used mostly aquatic habitats in low and high intensity human development year‐round. Rural ducks used freshwater marshes throughout the year, but selection of other habitat types varied seasonally. Use of glades marsh and agricultural habitats by rural ducks peaked during the breeding season. Rural ducks selected artificial impoundments and reservoirs during the post‐breeding and hunting periods. Median home range size of rural females was more than 65 times greater than those of urban females. Our results suggest the spread of mallard genetic introgression caused by females leaving urban areas may be slow because as few as 6% of the adult females moved between urban and rural areas. Focusing wetland conservation efforts on freshwater marshes and artificial impoundments in south Florida would likely benefit mottled ducks. © 2014 The Wildlife Society.
Corrosion potential and cathodic reduction efficiency of stainless steel in natural seawater
Authors: Thierry D. , Larché N. , Leballeur C. , Wijesinghe S. L. , Zixi T.
Published: June 2014

Stainless steels are widely used for different applications in seawater in the oil and gas and desalination industries. It is well known that the corrosion potential of stainless steel shifts to the noble direction (ennoblement) when exposed to natural seawater. The other significant effect of the biofilm on metallic surfaces is a dramatic increase of the cathodic reduction efficiency (e.g. cathodic reduction of dissolved oxygen), promoting the corrosion reactions and increasing the rate of corrosion propagation. Although, this has been widely studied in natural seawater at temperature ranging from 15 to 40 °C, very little is known on the effect of temperature (in a wider temperature range), dissolved oxygen content and chlorination level on the corrosion potential and the cathodic reduction efficiency of stainless steel in natural seawater. In this paper, corrosion potential and cathodic reduction efficiency of stainless steel are reported as a function of temperature (e.g. from 5 to 70 °C), dissolved oxygen content (e.g. from 20 ppb to saturation) and chlorination level (from 0 to 0.5 ppm). The results are discussed in terms of risk for crevice corrosion and bi‐metallic corrosion when coupling to other materials. In addition results from exposure in tropical sea are presented and compared to that of temperate seawater heated at the same temperature.
Pulse plated Zn transition layer in electroplating Sn–Ni alloy coatings on magnesium alloys
Authors: Chang L. M. , Zhou Y. , Liu W. , Duan X. Y.
Published: June 2014

An environmentally friendly Zn transition layer was electrodeposited on the AZ31 magnesium alloy substrate aimed to improve its corrosion resistance during the process of electroplating Sn–Ni alloy coating. Direct current (DC) and pulse current (PC) electroplated Zn layers with different thicknesses were compared. Scanning electron microscopy and X‐ray diffraction were employed to investigate the surface morphology and microstructure. The corrosion resistance of the Zn transition layers was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in Sn–Ni plating solution. The results showed that the Zn transition layer was essential for subsequent electroplating Sn–Ni alloy coating on magnesium alloy. For the same thickness, the application of the PC plating mode was more favorable to prepare compact, smooth, non‐porous, and fine Zn transition layer. Moreover, the corrosion resistance of PC plated Zn transition layer was enhanced compared to the DC plated layers. Most importantly, a Sn–Ni alloy coating could be successfully electrodeposited on magnesium alloy by using PC plated Zn transition layer.
Synergistic effect of AC and Cl− on corrosion behavior of X80 pipeline steel in alkaline environment
Authors: Zhu M. , Du C.‐W. , Li X.‐G. , Liu Z.‐Y.
Published: June 2014

The influence of AC on the corrosion behavior of X80 pipeline steel was investigated in chloride‐containing alkaline environment by electrochemical measurements and immersion tests. The results show that a superimposed AC degrades the passivity of the steel, shifts the corrosion potential negatively, and increases the corrosion rate. Both the increasing AC current density and the concentration of chloride ion accelerate the corrosion of the steel. With the addition of 0.2 M Cl− to the solution, AC and Cl− generate synergistic effect on the corrosion behavior of the pipeline steel, especially, the corrosion rate greatly increases and corrosion becomes more localized.
Synthesis and Characterization of Imino‐Phenolate Titanium Complexes and Their Use in Homo‐ and Copolymerization of Ethylene
Authors: da S. Gomes Fernando , Bergamo Adão L. , de L. Casagrande Osvaldo
Published: June 2014

A set of titanium precatalysts [(L)TiCl3] based on imino‐phenolate tridentate ligands (Ti1, L = 3,5‐tBu‐2‐(OH)C6H2CH‐N‐8‐C9H6N; Ti2, L = 3,5‐tBu‐2‐(OH)C6H2CH‐N‐C2H4‐O‐C6H5; Ti3, L = 3,5‐tBu‐2‐(OH)C6H2CH‐N‐CH2‐C6H4OMe; Ti4, L = 3,5‐tBu‐2‐(OH)C6H2CH‐N‐C6H4‐C6H5O) is prepared and characterized by elemental analysis, IR, and NMR spectroscopy. Upon activation with methylaluminoxane (MAO), these precatalysts show good activity (200–660 kg of PE mol[Ti]−1 h−1 at 60 °C) in ethylene polymerization yielding high‐density poly­ethylenes (HDPEs) with viscosity‐average molecular weight (Mv) in the range between 184 and 355 × 103 g mol−1. The Mv values of the resulting polyethylenes indicate strong influence of the aluminum concentration on the molecular weight, which can be associated to the probability of chain transfer from titanium to aluminum at high [Al]/[Ti] molar ratios. The polydispersity index (PDI) calculated from Gc(ωc) values are broad (24 to >40) indicating the multisite nature of this class of titanium precatalysts. Ti1–Ti4 are also tested in the copolymerization of ethylene with 1‐hexene affording high‐molecular‐weight poly(ethylene‐co‐1‐hexenes) with comonomer incorporation varying from 1.0 to 4.1 mol%. The crystallization analysis fractionation (CRYSTAF) profiles of copolymers produced by Ti2–Ti3 indicate the production of HDPE with very low efficiency (quantity and distribution) on incorporating 1‐hexene. On the other hand, the polymer produced by Ti1 shows a broad peak of branching fraction with different amount and comonomer distribution, suggesting a good 1‐hexene distribution along of main polymer chain.

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Synthesis and Crystallization of Precision Polymers with Repetitive Folding Elements
Authors: Reimann Sophie , Baumeister Ute , Binder Wolfgang H.
Published: June 2014

The synthesis and thermal properties of a new type of precision polyethylene containing perfectly placed conformationally constraining elements after every 16 methylene units are presented. The precise placement of a 2,6‐diaminopyridine moiety (DAP) is accomplished via acyclic diene metathesis (ADMET) polymerization of specially designed monomers, where the DAP serves as the conformational constraint. Polymerization of the diene‐mono­mer (N,N′‐pyridin‐2,6‐diyl‐bis‐dec‐9‐enamide) displaying free‐amide hydrogen bonds leads to largely insoluble polymers due to self‐aggregation via the hydrogen bonds and π–π stacking. However, when using the N‐methyl‐protected monomer N,N′‐pyridin‐2,6‐diylbis(N‐methyldec‐9‐enamide), the polymerization furnishes soluble polymers with molecular weights ranging from 1500 up to 60 000 g mol−1 using different Grubbs or Umicore catalysts. Matrix‐assisted laser desorption/ionization (MALDI) measurements prove the structure of linear and cyclic polymers, all containing the precisely placed DAP units within the polymer. Subsequent hydrogenation with p‐toluenesulfon­hydrazide yields the final semicrystalline polymers, displaying an ordered lamellar crystal phase as characterized via differential scanning calorimetry (DSC) and X‐ray diffraction (XRD) measurements.

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Effect of Varying Thiophene Units on Charge‐Transport and Photovoltaic Properties of Poly(phenylene ethynylene)‐alt‐poly(phenylene vinylene) Polymers
Authors: Adam Getachew , Yohannes Teketel , White Matthew , Montaigne Alberto , Ulbricht Christoph , Birckner Eckhard , Rathgeber Silke , Kästner Christian , Hoppe Harald , Sariciftci Niyazi Serdar , Egbe Daniel Ayuk Mbi
Published: June 2014

Poly(phenylene ethynylene)‐alt‐poly(phenylene vinylene)s (PPE‐PPVs) with various thiophene units (thiophene, bithiophene, and 3,4‐ethylenedioxythiophene) at the X position, with the general backbone design (PhCCXCCPhCHCHPhCHCH), bearing identical solubilizing side chains at the phenylene rings of the polymers, are synthesized to study the effect of this structural alteration on the properties such as the photophysics, the electrochemical properties, the charge‐carrier mobility, and the morphology of the materials and its impact on their photovoltaic performance. The polymers are obtained in good yields with reasonable molecular weights and show solubility in ordinary organic solvents required for solution‐processing applications. The polymer with a basic thiophene ring at the X positions shows the highest open‐circuit voltage (VOC of 930 mV) and the polymer with a bithiophene unit at the X position shows the highest short‐circuit current density and charge‐carrier mobility, whereas the polymer with 3,4‐ethylenedioxythiophene shows the lowest photovoltaic performance.

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A Multiple‐Responsive Self‐Healing Supramolecular Polymer Gel Network Based on Multiple Orthogonal Interactions
Authors: Zhan Jiayi , Zhang Mingming , Zhou Mi , Liu Bin , Chen Dong , Liu Yuanyuan , Chen Qianqian , Qiu Huayu , Yin Shouchun
Published: June 2014

Supramolecular polymer networks have attracted considerable attention not only due to their topological importance but also because they can show some fantastic properties such as stimuli‐responsiveness and self‐healing. Although various supramolecular networks are constructed by supramolecular chemists based on different non‐covalent interactions, supramolecular polymer networks based on multiple orthogonal interactions are still rare. Here, a supramolecular polymer network is presented on the basis of the host–guest interactions between dibenzo‐24‐crown‐8 (DB24C8) and dibenzylammonium salts (DBAS), the metal–ligand coordination interactions between terpyridine and Zn(OTf)2, and between 1,2,3‐triazole and PdCl2(PhCN)2. The topology of the networks can be easily tuned from monomer to main‐chain supramolecular polymer and then to the supramolecular networks. This process is well studied by various characterization methods such as 1H NMR, UV–vis, DOSY, viscosity, and rheological measurements. More importantly, a supramolecular gel is obtained at high concentrations of the supramolecular networks, which demonstrates both stimuli‐responsiveness and self‐healing properties.

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Novel Polymeric Materials with Double Porosity: Synthesis and Characterization
Authors: Droumaguet Benjamin Le , Lacombe Romain , Ly Haï‐Bang , Carbonnier Benjamin , Grande Daniel
Published: June 2014

This paper reports on two straightforward and versatile routes to functional doubly porous polymeric materials based on cross‐linked poly(2‐hydroxyethyl methacrylate) (PHEMA) via novel porogen templating methodologies. The quantitative removal of either CaCO3 particles or poly(methyl methacrylate) beads as macroporogens, in conjunction with either hydroxyapatite nanoparticles or a solvent as nanoporogens, led to the generation of macropores with dimensions in the 100 µm range, while the second porosity lied within the 1 µm order of magnitude, as evidenced by mercury intrusion porosimetry and scanning electron microscopy. The successful functionalization of such doubly porous PHEMA‐based frameworks was implemented through a straightforward two‐step chemical modification involving an activation stage, followed by the coupling of propargylamine as a model compound. Raman spectroscopy clearly indicated the occurrence of alkyne functionality within the biporous materials.
Particles Deposit Formation and Filtering: Numerical Simulation in the Suspension Flow Through a Dual Scale Fibrous Media
Authors: Haji Hind , Saouab Abdelghani , Park Chung Hae
Published: June 2014

We present numerical simulation of particle filled resin flow through a fibrous medium taking into account dual scale porosity in LCM (Liquid Composite Molding) processes. During the flow, a strong interaction between the particle motion and the fluid flow takes place at the porous medium wall or at the fiber bundle surface. A model is developed to describe the particle deposition and filtering in the porous medium. In this study, the Stokes‐Darcy equation is solved to describe the resin flow in a mesoscopic scale. The particle deposition mechanism is extensively studied taking into account the influences from such parameters as porous medium permeability, particle size and pressure drop. The mechanism leading to the accelerated or delayed filling is treated by analyzing the velocity filed around the fiber bundle surface. Finally, particle filtering simulation is performed for different particle loading levels to demonstrate the particle deposition and filtering mechanism during the composites manufacturing by LCM processes where the resin mixed with particles is injected into a fiber preform with dual scale porosity.
Dimensional assessment of anxiety disorders in parents and children for DSM‐5
Authors: Möller Eline L. , Majdandžić Mirjana , Craske Michelle G. , Bögels Susan M.
Published: June 2014

The current shift in the DSM towards the inclusion of a dimensional component allows clinicians and researchers to demonstrate not only the presence or absence of psychopathology in an individual, but also the degree to which the disorder and its symptoms are manifested. This study evaluated the psychometric properties and utility of a set of brief dimensional scales that assess DSM‐based core features of anxiety disorders, for children and their parents. The dimensional scales and the Screen for Child Anxiety Related Emotional Disorders (SCARED‐71), a questionnaire to assess symptoms of all anxiety disorders, were administered to a community sample of children (n = 382), aged 8–13 years, and their mothers (n = 285) and fathers (n = 255). The dimensional scales assess six anxiety disorders: specific phobia, agoraphobia, panic disorder, social anxiety disorder, generalized anxiety disorder, and separation anxiety disorder. Children rated their own anxiety and parents their child's anxiety. The dimensional scales demonstrated high internal consistency (α > 0.78, except for father reported child panic disorder, for reason of lack of variation), and moderate to high levels of convergent validity (rs = 0.29–0.73). Children who exceeded the SCARED cutoffs scored higher on the dimensional scales than those who did not, providing preliminary support for the clinical sensitivity of the scales. Given their strong psychometric properties and utility for both child and parent report, addition of the dimensional scales to the DSM‐5 might be an effective way to incorporate dimensional measurement into the categorical DSM‐5 assessment of anxiety disorders in children. Copyright © 2014 American Psychiatric Association. All rights reserved.
Highly Efficient and Stereoselective Construction of Bispirooxindole Derivatives via a Three‐Component 1,3‐Dipolar Cycloaddition Reaction
Authors: Xu Qin , Wang De , Wei Yin , Shi Min
Published: June 2014

A highly regio‐ and stereoselective synthesis of bispirooxindoles by 1,3‐dipolar cycloaddition of in situ generated azomethine ylides from isatin and proline to different electron‐deficient alkenes has been developed. The synthesis affords the desired bispiro scaffold compounds in excellent yields with high regioselectivity under mild conditions. The stereochemistry was determined by single‐crystal X‐ray analysis.
Magnetic Resonance Access to Transiently Formed Protein Complexes
Authors: Sára Tomáš , Schwarz Thomas C. , Kurzbach Dennis , Wunderlich Christoph H. , Kreutz Christoph , Konrat Robert
Published: June 2014

Protein–protein interactions are of utmost importance to an understanding of biological phenomena since non‐covalent and therefore reversible couplings between basic proteins leads to the formation of complex regulatory and adaptive molecular systems. Such systems are capable of maintaining their integrity and respond to external stimuli, processes intimately related to living organisms. These interactions, however, span a wide range of dissociation constants, from sub‐nanomolar affinities in tight complexes to high‐micromolar or even millimolar affinities in weak, transiently formed protein complexes. Herein, we demonstrate how novel NMR and EPR techniques can be used for the characterization of weak protein–protein (ligand) complexes. Applications to intrinsically disordered proteins and transiently formed protein complexes illustrate the potential of these novel techniques to study hitherto unobserved (and unobservable) higher‐order structures of proteins.
Synthesis and Photochromic Properties of Configurationally Varied Azobenzene Glycosides
Authors: Chandrasekaran Vijayanand , Johannes Eugen , Kobarg Hauke , Sönnichsen Frank D. , Lindhorst Thisbe K.
Published: June 2014

Spatial orientation of carbohydrates is a meaningful parameter in carbohydrate recognition processes. To vary orientation of sugars with temporal and spatial resolution, photosensitive glycoconjugates with favorable photochromic properties appear to be opportune. Here, a series of azobenzene glycosides were synthesized, employing glycoside synthesis and Mills reaction, to allow “switching” of carbohydrate orientation by reversible E/Z isomerization of the azobenzene N=N double bond. Their photochromic properties were tested and effects of azobenzene substitution as well as the effect of anomeric configuration and the orientation of the sugars 2‐hydroxy group were evaluated.
Thermal, mineralogical, and microstructural characterizations of irradiated polymer blended cement mortar composites
Authors: El‐Hamouly Sabrnal H. , Ismail Mohamed R. , Abdel‐Rahman Hoda A. , Younes Maha M. , Amin Eiman H.
Published: June 2014

In this study, the effects of styrene–acrylic ester (SAE), nanocalcined clay (NCC), and irradiation dose on the thermal, mineralogical, and microstructural characterizations of irradiated polymer‐blended cement mortar composites have been investigated. The composites were prepared by partial replacement of cement with 5 and 10% NCC and mixed with sand, SAE latex was added with different ratios (2, 4, 6, 8, 10, and 15%); the composites were subjected to various doses of γ‐irradiation ranged from 10 to 50 kGy. Physicomechanical properties, thermogravimetric analysis, X‐ray diffractometry, and scanning electron microscopy techniques were carried out. Mechanical investigation manifested that composites loaded with SAE up to 8% showed the best mechanical performance as compared with composites contains 10 and 15% SAE. POLYM. COMPOS., 36:1849–1858, 2015. © 2014 Society of Plastics Engineers