bluuebunny/crossref_metadata_2025_split huggingface dataset:
Importance of grazing and soil acidity for plant community composition and trait characterisation in coastal dune grasslands
Authors: Tahmasebi Kohyani P. , Bossuyt B. , Bonte D. , Hoffmann M. 
Published: February 2008

Question: Does grazing by large herbivores affect species composition or community‐wide variation in plant functional traits?Location: Dune grasslands at the Belgian coast. Methods: Plant cover and soil data were collected in 146 plots that were randomly selected at 26 grazed and ungrazed grassland sites. Plant community composition was assessed by Detrended Correspondence Analysis and mean values of plant trait categories were calculated across the plots.Results: Differentiation of plant composition and community‐wide plant trait characteristics was largely determined by grazing, soil acidity and their interaction. In ungrazed situations, a clear floristic distinction appears between acidic (non‐calcareous) and alkaline (calcareous) grasslands. In grazed situations, these floristic differences largely disappeared, indicating that grazing results in a decrease of natural variation in species composition. At higher soil pH, a larger difference in plant community composition and community‐wide plant traits was observed between grazed and ungrazed plots. In ungrazed situations, shifts in plant functional traits along the acidity gradient were observed.Conclusions: Grazing is responsible for shifts in plant community composition, and hence a decrease in plant diversity among grasslands at opposing acidity conditions in coastal dune grasslands. Therefore, care should be taken when introducing grazing as a system approach for nature conservation in dune grasslands as it may eliminate part of the natural variation in plant diversity along existing abiotic gradients.
On the microhardness testing of electrically stressed poly(phenylene oxide): Polystyrene blends
Authors: Mitra Tulika , Bajpai R. , Keller J. M. 
Published: February 2008

AbstractMicrohardness measurements have been performed on untreated (virgin) and electrically stressed, solvent‐cast laboratory‐prepared samples of pure poly(phenylene oxide) (PPO), pure polystyrene (PS), and PPO : PS polyblends with different weight proportions. Results of such measurement on untreated polyblend sample show that microhardness (Hv) increases with increase in the content of PS up to 10 wt %, which attributed to the existence of homogeneous phase morphology. However, this feature is not observable in samples containing higher content of PS. Electrical stress is found to modify considerably the mechanical property of polymer. The effect of electric field on the microhardness of such samples (PPO : PS :: 90 : 10) has been characterized by the existence of a peak. Trapping of charge carriers in electrically stressed samples imparts hardening to the polyblend up to an applied step field of 190 kV/cm. However, the excessive charging beyond this step field value destroys this characteristic. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dielectric relaxation and alternating‐current conductivity of gadolinium‐doped poly(vinyl alcohol)
Authors: Hanafy T. A. 
Published: February 2008

AbstractThe dielectric constant, dielectric loss factor, and alternating‐current conductivity of Gd‐doped poly(vinyl alcohol) (PVA) samples have been studied in the temperature and frequency ranges of 290–450 K and 50–5 × 106 Hz, respectively. Three relaxation processes—αa, αc, and ρ—have been obtained. The first one is due to the rotation of OH and CO groups inside the amorphous part of PVA. The second process is due to the dipole relaxation in the crystalline phase of the sample. The changes in the peak position and height of αa and αc have been interpreted in light of the formation of complexes between GdCl3 and OH and CO groups of the PVA structure. On the other hand, the ρ‐relaxation process is due to the space‐charge formation between the different phases inside the PVA samples. Alternating‐current conductivity measurements of the investigated samples have revealed that the hopping conduction mechanism is predominant. The maximum barrier height and the activation energy have been calculated and reported. In the low temperature range (306–333 K), the responsible conduction mechanisms of PVA doped with 2 or 4 wt % GdCl3 have been found to be small polaron tunneling and quantum mechanical tunneling, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of polymeric nitrocellulose membranes: Influence of additives and pore formers on the membrane morphology
Authors: Ahmad A. L. , Low S. C. , Shukor S. R. Abd. , Ismail A. 
Published: February 2008

AbstractThe control of the membrane surface and cross‐section morphology is extremely important in the enhancement of the wicking and binding ability of the lateral flow membrane, which is one of the processing materials in medicine and health care analysis devices. The lateral flow rate and protein‐binding performance is based on the thin layers of the membrane. The challenge of this study was to combine the influences of additives and pore‐former materials to obtain a thin lateral flow nitrocellulose membrane with controlled membrane morphologies. Water was found to be an effective pore former for enhancing the porosity and pore size of the membrane. However, too high of a water content increased the surface roughness and decreased the membrane protein‐binding ability. Different properties of the individual plasticizers/additives contributed to the disparity of membrane performance in binding and solute lateral wicking time. The correlations between the effects of additives and pore former toward the final membrane structure and performance of the membrane‐forming system are discussed extensively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of the melt viscoelastic behavior of components on the morphology development of polymer blends in a twin‐screw extruder
Authors: Barangi L. , Nazockdast H. , Taromi F. Afshar 
Published: February 2008

AbstractThe aim of this work was to study the role of effective parameters in the morphology evolution of polymer blends in a twin‐screw extruder with an emphasis on the effects of the melt viscoelastic properties of the blend components, screw speed, and flow field changes along the extruder. Two sets of blend samples based on polypropylene/polyamide 6 with the same composition (90/10) and polypropylene matrix but with two polyamide 6 grades differing in their viscoelastic properties were considered. The effect of the compatibilizer (maleic anhydride grafted polypropylene) was also investigated. The morphology of the blend samples were studied with scanning electron microscopy, and the melt linear viscoelastic properties of the samples were measured with a rheometric mechanical spectrometer. The melt‐blending processes were carried out in a modular twin‐screw extruder. The trend of the polyamide dispersed particle size changing with increasing screw speed was found to be different for the two types of blends. Considering of the role of the compatibilizer in coalescence, this could mainly be attributed to the different melt viscoelastic properties of the blend constituents. Similar explanations were given for the morphological changes that occurred along the screw. It was demonstrated that the viscosity ratio of the blend components is not necessarily the only material‐dependent parameter that affects the dispersed particle size: the viscoelastic properties (particularly the flow‐induced elasticity ratio) of the blend components can also play a significant role in determining the particle size distribution. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dynamic rheological study of paraffin wax and its organoclay nanocomposites
Authors: Wang Jinfeng , Calhoun Mark D. , Severtson Steven J. 
Published: February 2008

AbstractDynamic rheological data for paraffin wax and its organoclay nanocomposites are reported. Dynamic mechanical analysis of paraffin wax for temperatures ranging from −40 to 55°C showed a decrease of several orders of magnitude in the dynamic moduli and a significant shift toward viscous behavior, which resulted from the occurrence of two solid–solid phase transitions. In both the crystalline and mesophase regions, the dispersion of organoclay platelets in paraffin wax via ultrasonication increased the storage modulus, whereas the effect on the loss modulus was temperature‐dependent. The melt rheology data of the wax–clay nanocomposites at 70°C showed that the complex viscosities increased monotonically with clay addition and demonstrated shear‐thinning behavior for frequencies between 0.1 and 100 rad/s. The complex viscosity versus angular frequency data were well fit by a power‐law function for which the shear‐thinning exponent provides a gauge for the extent of clay exfoliation. The nanocomposites exhibited low‐frequency solid behavior, which indicated good exfoliation of the organoclay in the wax matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and characterization of Maillard reacted chitosan films with hemicellulose model compounds
Authors: Umemura Kenji , Kawai Shuichi 
Published: February 2008

AbstractThe Maillard reaction between chitosan and hemicellulose model compounds such as mannose, xylose, and glucuronic acid was investigated. Chitosan and the compounds were dissolved in 1% acetic acid and were dried at 50°C. In an analysis of the film obtained, weight increase, color difference, FTIR, relative amount of free amino groups, insolubility to dilute acetic acid, and tensile properties were measured. The film weight increased gradually as the compounds were added, and the color difference changed significantly. In addition, the relative amount of free amino groups decreased rapidly, and the insoluble matter increased markedly. In particular, xylose brought about drastic changes in a small amount addition. According to the results of FTIR spectra, the cleavage of sugar unit of chitosan and the formation of heterocyclic compounds were observed in all compounds. The formation of carbonyl and carboxyl groups was observed with the addition of a large amount of the compounds. The tensile strength was improved in 10–20 wt % additions of the compounds. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Compatibilization of commingled plastics with maleic anhydride modified polyethylenes and ultraviolet preirradiation
Authors: Martínez J. G. , Benavides R. , Guerrero C. 
Published: February 2008

AbstractThe improvement of the properties of commingled plastics was carried out with a prototype blend of Mexican municipal plastic waste with and without poly(vinyl chloride) (PVC). Compatibilizing agents such as high‐density, low‐density, and linear low‐density polyethylenes modified with maleic anhydride were used. The agents were prepared in the laboratory with peroxide, and their usefulness was compared with that of a commercially modified linear low‐density polyethylene. The blends with PVC were preirradiated with ultraviolet radiation for 12, 24, or 48 h to create oxidized groups to help in situ compatibilization during the blending step of the reactive extrusion process. Compatibilized materials showed a markedly more homogeneous morphology with improved mechanical properties: the elongation at break and impact strength increased with the compatibilization level. The presence of PVC in commingled plastics significantly reduced the beneficial effect of the maleic anhydride modified polyethylene as a compatibilizer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Biofuels, climate change and industrial development: can the tropical South build 2000 biorefineries in the next decade?
Authors: Mathews John A. 
Published: February 2008

AbstractBiofuels are important because they span three of the greatest issues of our time –world industrial development; energy security and the transition to a bioeconomy; and global warming. Biofuels have something important to contribute as a solution in each of these three areas –without being a ‘magic bullet’ or the whole of the solution in any of them. Indeed, biofuels may be a transitory solution that will phase out after two or three decades as new electric‐powered transport systems take over. But in the meantime, biofuels have the potential to bring together North and South in a new Biopact of transcendent significance, promising to allow countries of the South to lift themselves out of poverty through biofuel cultivation, processing and export; and countries of the North to solve their transport and global warming problems by opening up to biofuels produced sustainably and responsibly from the tropical South. A goal of 2000 biorefineries over the course of the next decade is entirely realistic: their output would be of the order of 400 billion liters of ethanol and/or biodiesel, or about one fifth of OECD countries' current transport fuel requirements. The investment required would be of the order of US$240 billion over a decade –compared with the more than $470 billion expected by the International Energy Agency (IEA) to be invested in the oil and gas industry in a single year by 2010. In this light, the investment required is modest. Such an investment can only be undertaken if markets in the North are guaranteed. The best means of achieving such an investment‐grade guarantee is through a comprehensive global trade agreement. But the prospects for such an agreement are vitiated by the cacophony of opposition to biofuels raised in the North, by non‐governmental organizations (NGOs) and vested interests, who are raising hysterical concerns over the transition from fossil fuels to biofuels, and stand accused of seeking industrial protection under the guise of environmental concerns. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd
Der Bien – ein Säugetier mit vielen Körpern. Superorganismus Bienenstaat
Authors: Tautz Jürgen 
Published: February 2008

AbstractDie Kooperation tausender von Individuen in den Kolonien der Honigbienen ermöglicht diesen Superorganismen eine soziale Homöostase, die auf funktionellen Merkmalen beruht, die in dieser Kombination auch bei der ebenfalls sehr erfolgreichen Gruppe der Säugetiere zu finden sind. Dieses Paket an Eigenschaften führt bei den Säugetieren und dem Superorganismus Bienenstaat zu einer hohen Unabhängigkeit von direkten Umwelteinflüssen und erlaubt diesen Organismen, in wenige, aber dafür bestens ausgestattete Nachkommen zu investieren.
Ein Zensus des Marinen Lebens in der Arktis. Biodiversität rund um den Nordpol
Authors: Bluhm Bodil , Gradinger Rolf , Hüttmann Falk , Hopcroft Russ R. , Gebruk Andrey , Sirenko Boris 
Published: February 2008

AbstractArctic Ocean Diversity (ArcOD) ist ein Projekt des internationalen Zensus des Marinen Lebens (CoML). Es hat zum Ziel, die Kenntnis über Vorkommen, Verbreitung, Häufigkeit und ökologische Funktion der marinen Arten im arktischen Meereis, in der Wassersäule und am Meeresboden zu verbessern. Dazu werden existierende und neue Daten von Mikroalgen bis zu Wirbeltieren – vom Flachwasser bis in die Tiefsee – in einer der Öffentlichkeit frei zugänglichen Datenbank zusammengetragen, Proben auf Artniveau identifiziert und neue Sammlungen unternommen, um Wissenslücken zu füllen. Diese Bemühungen sind aufgrund des weltweiten Klimawandels und seiner Auswirkungen in der Arktis besonders dringend.
Menagerie der RNAi‐Fliegen
Authors: Kronberg Inge 
Published: February 2008

AbstractIm Jahr 2000 wurde das Genom der Taufliege Drosophila melanogaster sequenziert. Man kennt also weitgehend die Reihenfolge von 160 Millionen DNA‐Basen, aber die Funktion der etwa 15.000 proteincodierenden Gene ist damit noch nicht verstanden. Um die Bedeutung eines Gens zu klären, schaltet man es am besten aus und beobachtet die phänotypischen Folgen. Solche Knockdown‐Tiere lassen sich mittels RNA‐Interferenz (RNAi) gezielt erzeugen. Durch eine trickreiche Kombination gentechnischer Methoden ist es einer Wiener Arbeitsgruppe gelungen, Stämme von über 20.000 RNAi‐Fliegenvarianten lebend in einer “library” bereit zu halten.
Vietnam: Meeresschildkröten – gefährdete Symbole der Unsterblichkeit
Authors: Thanh Le Thi , Kronberg Inge 
Published: February 2008

AbstractSie gelten als Symbole der Weisheit und Unsterblichkeit: Schildkröten können über 200 Jahre alt werden und haben ein erdgeschichtliches Alter von etwa 220 Millionen Jahren. In den vergangenen Jahrzehnten hat ihr Bestand jedoch weltweit erheblich abgenommen. Alle sieben bekannten Meeresschildkröten‐Arten sind vom Aussterben bedroht. Ein Artenschutzprogramm muss daher in unterschiedlichen Bereichen ansetzen und ist gerade in Ländern wie Vietnam nicht ohne internationale Zusammenarbeit möglich.
Proteinarrays können Nebenwege von Tumor‐Wirkstoffen im Brustkrebs aufdecken
Authors: Korf Ulrike , Löbke Christian , Sahin Özgür , Arlt Dorit , Wiemann Stefan , Sültmann Holger , Poustka Annemarie 
Published: February 2008

AbstractDer so genannte HER2‐Rezeptor ist in vielen Tumoren, insbesondere der Brust, verstärkt zu finden. Dabei handelt es sich jedoch um nur einen Vertreter einer vier Mitglieder umfassenden Proteinfamilie, die bei Aktivierung unterschiedliche Signalwege vermitteln. Jetzt haben sich Forscher im Nationalen Genomforschungsnetz (NGFN) der Fragestellung gewidmet, wie weitreichend die medikamentöse Blockierung eines einzelnen Vertreters dieser Rezeptorfamilie für den Stoffwechsel des Tumors ist. Für diesen Zweck haben sie einen sehr sensitiven Proteinarray entwickelt, der viele Signalwege gleichzeitig erfasst und so auch deren komplexe Zusammenhänge aufzeigt.
Effect of Target Walls on the Breakage of Composite Particles
Authors: Khanal M. , Tomas J. 
Published: February 2008

AbstractThe DEM simulation of the effect of target walls on the comminution of composite particles is studied. Different designs of target walls were considered to achieve the maximum liberation degree, suitable particle size distributions and new surface generation. Concrete spheres of strength category B35 were chosen to represent the composite particles. Depending on the design of the target walls, cracks were generated and propagated under impact. It was noted that crack initiation and propagation at the considered targets were mostly due to the generated shear and tensile stresses. Particle size distributions showed similar trends under impact at different target walls. Under simulated conditions, different target walls showed different liberation degrees depending on the impact velocities.
ChemInform Abstract: Synthesis and Crystal Structures of DyPt8P2 and Mg10‐xPt9P7.
Authors: Imre Anette , Mewis Albrecht 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Thermoelectric Properties of Nb3Sb2Te5.
Authors: Soheilnia Navid , Giraldi Jonathan , Assoud Abdeljalil , Zhang Huqin , Tritt Terry M. , Kleinke Holger 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: New Potassium Bismuth Thiophosphates Including the Modulated K1.5Bi2.5(PS4)3.
Authors: Gave Matthew A. , Weliky David P. , Kanatzidis Mercouri G. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Various P*‐Chiral Phosphite‐Type Ligands: Their Synthesis, Stereochemistry and Use in Pd‐Catalyzed Allylation.
Authors: Benetsky Eduard B. , Zheglov Sergey V. , Grishina Tatiana B. , Macaev Fliur Z. , Bet Luidmila P. , Davankov Vadim A. , Gavrilov Konstantin N. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Palladium‐Catalyzed 1,3‐Diol Fragmentation: Synthesis of ω‐Dienyl Aldehydes.
Authors: Kimura Masanari , Mori Masahiko , Tamaru Yoshinao 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthetic Potential of 2‐Oxobenzo[h]chromene for the Construction of Polycyclic Azaheteroaromatics with a Steroid‐Like Skeleton.
Authors: Pratap Ramendra , Ram Vishnu Ji 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Novel Construction of Hydro‐2‐benzazepines Based on 7‐endo Selective Friedel—Crafts‐Type Reaction of Vinyloxiranes.
Authors: Nagumo Shinji , Mizukami Megumi , Wada Koji , Miura Toshie , Bando Hideo , Kawahara Norio , Hashimoto Yasunori , Miyashita Masaaki , Akita Hiroyuki 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Solvent‐Free Heterogeneous Organocatalysis: Stereoselective Isomerization of α,β‐Ynones to (E,E)‐α,.beta±gamma.,δ‐Dienones Catalyzed by Polymer‐Supported Tertiary Phosphines.
Authors: Liu Hai‐Ling , Jiang Huan‐Feng , Xu Lin , Zhan Hai‐Ying 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: DMSO‐Aided o‐Iodoxybenzoic Acid (IBX) Oxidation of Fmoc‐Protected Amino Alcohols.
Authors: Chen Jack J. , Aduda Vince 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Triiodoisocyanuric Acid: A New and Convenient Reagent for Regioselective Coiodination of Alkenes and Enolethers with Oxygenated Nucleophiles.
Authors: da S. Ribeiro Rodrigo , Esteves Pierre M. , de Mattos Marcio C. S. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.