bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melt suspension crystallization for purification of phosphoric acid
Authors: Chen Aimei , Zhu Jiawen , Chen Kui , Wu Bin , Ji Lijun , Wu Yanyang 
Published: June 2012

ABSTRACTA continuous melt suspension crystallization process has been presented for the purification of the phosphoric acid in this study, which is conducted in the cascade of a continuous mixed suspension and mixed product removal (MSMPR) crystallization and subsequent countercurrent solid–liquid contact in a gravity wash column. With magma withdrawn from the MSMPR crystallizer being fed into the top of the gravity wash column, crystals settle down toward the bottom of column and the reflux melt rises upward, whereas the sweating of crystals and counter‐current contact between crystal particles and the melt lead to high separation capability of impurities. The gravity wash column used in this study is a vertical agitated cylindrical column, whose configuration is different from the inclined column crystallizer. The feasibility of suspension crystallization equipment for purification of phosphoric acid was studied. Distribution of impurities in the wash column was also investigated as a function of the feed concentration, crystal bed height, reflux ratio and stirring speed. Reflux ratio has been found to play an important role in the process. Food grade phosphoric acid can be achieved when the process is operated with feed concentrations of 84 ~ 86 wt.%, reflux ratios of 3.4 ~ 6.2, stirring speed of 10 rpm and crystal bed height of 150 ~ 250 mm in a gravity wash column. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Polymer nanocomposite‐based shielding against diagnostic X‐rays
Authors: Nambiar Shruti , Osei Ernest K. , Yeow John T. W. 
Published: June 2012

AbstractLead is commonly used in medical radiology departments as a shielding material. Lead‐based protective materials are also used by clinical personnel during X‐ray image‐guided interventional radiology (IVR) procedures. However, lead is extremely toxic and prolonged exposure to it can result in serious health concerns. Polymer composites, on the other hand, can be designed to be lead‐free in addition to being lightweight, conformable, cost effective, and potentially capable of significantly attenuating X‐rays. Nanomaterials have unique material properties that can be exploited to develop novel lead‐free radiation‐protection materials. In this study, polydimethylsiloxane (PDMS) nanocomposites were fabricated using different weight percentages (wt %) of bismuth oxide (BO) nanopowder. The attenuation properties of the nanocomposites were characterized using diagnostic X‐ray energies from 40 to 150 kV tube potential and were compared to the attenuation characteristics of 0.25‐mm‐thick pure lead sheet. The PDMS/BO nanocomposite (44.44 wt% of BO and 3.73‐mm thick) was capable of attenuating all the scattered X‐rays generated at a tube potential of 60 kV, which is the beam energy commonly employed in IVR. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Plasticized and nanofilled poly(lactic acid)‐based cast films: Effect of plasticizer and organoclay on processability and final properties
Authors: Scatto Marco , Salmini Elena , Castiello Stefania , Coltelli Maria‐Beatrice , Conzatti Lucia , Stagnaro Paola , Andreotti Leonardo , Bronco Simona 
Published: June 2012

AbstractPLA‐based nanocomposites filled with the commercial organomodified montmorillonite Dellite 43B (D43B) and containing acetyl tri‐n‐butyl citrate (ATBC) as plasticizer were prepared by extrusion in a pilot‐scale twin‐screw extruder and melt casted into flexible films. A preliminary investigation was carried out in a laboratory batch mixer by varying blending conditions and addition procedures of the components. Indeed, the method of addition of ATBC and D43B considerably affected thermo‐mechanical properties and morphology of the resultant nanocomposites. The simultaneous introduction of both ATBC and D43B during the extrusion process allowed producing clearly exfoliated nanocomposite materials with modulated mechanical and thermal properties. Moreover, rheological results, obtained during melt extrusion, assessed the processability of nanofilled‐plasticized PLA, making this simple procedure interesting in view of the industrial production of nanostructured biomaterials based on plasticized PLA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Viscoelastic properties of short aramid fibers‐reinforced rubbers
Authors: Shirazi M. , Talma A. G. , Noordermeer J. W. M. 
Published: June 2012

AbstractAmong short fiber‐reinforced composites, those with rubber matrices have gained great importance due to the advantages they have in processing and low cost, coupled with high strength. These composites combine the elastic behavior of rubbers with strength and stiffness of fibers. Reinforcement with short fibers offers attractive features such as design flexibility, high modulus, tear strength, etc. The degree of reinforcement depends upon many factors such as: the nature of the rubber matrix, the type of fiber, the concentration and orientation of the fibers, the fiber to rubber adhesion and fiber length. One of the main features related to this class of composites is their hysteretic properties which are of great importance especially in dynamic applications such as tire treads. In this research, short aramid fibers with different kinds of surface treatments: Standard finish and resorcinol formaldehyde latex (RFL)‐coating, have been applied in two different carbon black filled rubber compounds based on natural rubber (NR) and ethylene propylene diene rubber (EPDM). The dynamic properties of the compounds have been measured as influenced by the different kinds of fiber treatments on rubber‐fiber interaction. Finally, the contribution of the interfaces and/or interphase layers to the loss properties is characterized. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Fundamental studies on a new series of SPSEBS‐PVA‐QPSEBS bipolar membrane: Membrane preparation and characterization
Authors: Venugopal Krishnaveni , Dharmalingam Sangeetha 
Published: June 2012

AbstractA sulfonated polystyrene ethylene butylene polystyrene (SPSEBS)‐poly(vinyl alcohol) (PVA)‐Quaternized polystyrene ethylene butylene polystyrene (QPSEBS) bipolar membrane (BPM) was prepared by lamination method using PSEBS as the starting material, the functionalization of which was modified by sulfonation and amination while PVA was used as the intermediate layer to enhance the water splitting efficiency. The cross section view of SPSEBS‐PVA‐QPSEBS BPM was studied by SEM. Fourier transform infra‐red spectroscopy (FTIR) studies indicated that the prepared BPM contained –SO, –NR, and –C‐N functional groups. The thermal stability of the prepared BPM was studied by thermogravimetric analysis (TGA). Some of the BPM characteristics results showed that the co‐ion fluxes was greater for t(0.065) when compared with t(0.051) along with a water splitting capacity value of 0.88 for SPSEBS‐PVA‐QPSEBS BPM. The water dissociation flux was 2.8 × 10−5 mol/m2/s and 2.2 × 10−5 mol/m2/s for the acid (H+) and base (OH−), respectively. The other essential current‐voltage characteristics and permeate flux across the membrane were also evaluated. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci 2013
In situ silica reinforcement of vinyltriethoxysilane‐grafted styrene–butadiene rubber by sol–gel process
Authors: Yin Changjie , Zhang Qiuyu , Gu Junwei , Zheng Jucheng , Gong Guangbi , Liang Tao , Zhang Hepeng 
Published: June 2012

AbstractGrafting polymerization of vinyltriethoxysilane (VTES) onto styrene–butadiene rubber (SBR) was firstly carried out in latex, using potassium persulfate (KPS) as initiator. The grafted SBR was further reinforced with silica produced by sol–gel reaction of tetraethoxysilane (TEOS). The grafted of VTES onto SBR was characterized and confirmed by ATR‐FTIR and 1H‐NMR. Results revealed that the addition of VTES could considerably improve the content of silica, bound rubber in SBR and utilized efficiency of TEOS. Meanwhile, the curing characteristics and mechanical properties of the vulcanized in situ reinforced SBR‐g‐VTES were also investigated and compared with that of the silica‐reinforced SBR prepared by mechanical mixing. The delta torque, tensile, and tear strength of in situ reinforced SBR‐g‐VTES were higher than that of silica‐reinforced SBR. Dynamic mechanical analysis showed that the interaction between silica and SBR of in situ reinforced SBR‐g‐VTES was also better than that of the silica‐reinforced SBR. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
A novel approach to prepare etoposide‐loaded poly(N‐vinyl caprolactam‐co‐methylmethacrylate) copolymeric nanoparticles and their controlled release studies
Authors: Shah Sunil , Pal Angshuman , Gude Rajiv , Devi Surekha 
Published: June 2012

AbstractA series of copolymeric nanoparticles of methyl methacrylate and N‐vinylcaprolactam were synthesized from microemulsions containing sodium dodecyl sulfate. Etoposide as a model drug was loaded in nanoparticles during in situ polymerization. Stable nanolatex were produced and characterized for size and shape by dynamic light scattering (DLS) and transmission electron microscopy. Particles were found to be spherical in nature with size less than 50 nm. Structural characterization of copolymers was done by infrared and nuclear magnetic resonance spectroscopy. Differential scanning calorimetery (DSC) and X‐ray diffractometry (XRD) techniques were used to evaluate molecular level interaction of etoposide with nanoparticles. Drug encapsulation efficiency was determined by ultraviolet (UV) spectrometry and found to be 35–67%. DSC, XRD, and UV data suggested the molecular level dispersion of drug in the nanoparticles. In vitro release studies and in vitro cytotoxicity showed prolonged and controlled release of etoposide from nanoparticles along with IC50 values of nanoparticles in the range of 0.01–0.1 mg/mL. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Preparation and characterization of a novel strong‐base anion exchange fiber
Authors: Wang Jing , Lv Xiang Hua , Zhao Liang , Sha Baofeng , Zhao Dong , Zhu Chengshen 
Published: June 2012

AbstractA novel strong‐base anion exchange fiber (QAPAN) was prepared in this study by preamination of a commercial poly(acrylonitrile) fiber followed by its subsequent grafting of glycidyl trimethylammonium chloride (GTA). The grafting conditions were optimized by conducting a L18 (37) orthogonal test; and properties of the prepared QAPAN were investigated by multiple analyses. Results showed that the optimal reaction conditions were GTA dosage 4 mL, temperature 60°C, reaction time 6 h, and volume ratio of water to dimethyl sulfoxide (DMSO) 0.5 : 0.5, among which volume ratio of water to DMSO was deemed as the most important factor on the QAPAN preparation. The prepared QAPAN had excellent fibrous morphology and fine mechanical stability, making its further processing feasible. Acid–base titration tests showed that the QAPAN had a total exchange capacity (TEC) of 6.34 mmol/g and a strong base capacity (SBC) of 1.34 mmol/g. Analyses of Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy further verified that the quaternary ammonium group was successfully grafted onto the QAPAN. This study provided a novel strong‐base anion exchange fiber as well as a simple and repeatable method for its preparation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Poly(ethylene oxide)‐multiwall carbon nanotube composites: Effect of dicarboxylic acid salt‐based modifiers
Authors: Jagtap S. B. , Kushwaha R. K. , Ratna D. 
Published: June 2012

AbstractAn investigation was carried out to improve the dispersion of multiwall carbon nanotubes (MWCNTs) in the poly(ethylene oxide) (PEO) matrix using a half‐neutralized sodium salt of dicarboxylic acid with various number of carbon atoms. The effects of nature of various modifiers on mechanical properties of PEO were investigated. Among various dicarboxylic acid salts, half neutralized adipic acid (HNAA) is found to be highly effective in achieving the improvement in mechanical and dynamic mechanical properties due to improved dispersion of MWCNT in the PEO matrix. The physical interaction of HNAA with MWCNT (cation–π interaction) has been established using Fourier transform infrared and Raman spectroscopic analyses. Scanning electron microscope and transmission electron microscope (TEM) studies clearly indicate the improvement in the level of dispersion of MWCNT due to the addition of HNAA. Crystallization behavior of the PEO/MWCNT composites made with unmodified and modified MWCNT were studied by differential scanning colorimetry. Our approach is a noncovalent one and does not destroy the π‐electron clouds of MWCNT as opposed to chemical functionalization techniques and particularly attractive because of possibility of preserving the structural integrity of nanotubes as well as improved phase adhesion with polymer matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Shearing Mechanics and the Influence of a Flexible Symphysis During Oral Food Processing in Sphenodon (Lepidosauria: Rhynchocephalia)
Authors: Jones Marc E.H. , O'higgins Paul , Fagan Michael J. , Evans Susan E. , Curtis Neil 
Published: June 2012

AbstractThe New Zealand tuatara, Sphenodon, has a specialized feeding system in which the teeth of the lower jaw close between two upper tooth rows before sliding forward to slice food apart like a draw cut saw. This shearing action is unique amongst living amniotes but has been compared with the chewing power stroke of mammals. We investigated details of the jaw movement using multibody dynamics analysis of an anatomically accurate three‐dimensional computer model constructed from computed tomography scans. The model predicts that a flexible symphysis is necessary for changes in the intermandibular angle that permits prooral movement. Models with the greatest symphysial flexibility allow the articulation surface of the articular to follow the quadrate cotyle with the least restriction, and suggest that shearing is accompanied by a long axis rotation of the lower jaws. This promotes precise point loading between the cutting edges of particular teeth, enhancing the effectiveness of the shearing action. Given that Sphenodon is a relatively inactive reptile, we suggest that the link between oral food processing and endothermy has been overstated. Food processing improves feeding efficiency, a consideration of particular importance when food availability is unpredictable. Although this feeding mechanism is today limited to Sphenodon, a survey of fossil rhynchocephalians suggests that it was once more widespread. Anat Rec, 2012. © 2012 Wiley‐Periodicals, Inc.
Moonlighting is mainstream: Paradigm adjustment required
Authors: Copley Shelley D. 
Published: June 2012

AbstractMoonlighting – the performance of more than one function by a single protein – is becoming recognized as a common phenomenon with important implications for systems biology and human health. The different functions of a moonlighting protein may use different regions of the protein structure, or alternative structures that occur due to post‐translational modifications and/or differences in binding partners. Often the different functions of moonlighting proteins are used at different times or in different places. The existence of moonlighting functions complicates efforts to understand metabolic and regulatory networks, as well as physiological and pathological processes in organisms. Because moonlighting functions can play important roles in disease processes, an improved understanding of moonlighting proteins will provide new opportunities for pharmacological manipulations that specifically target a function involved in pathology while sparing physiologically important functions.
The lipid raft hypothesis revisited – New insights on raft composition and function from super‐resolution fluorescence microscopy
Authors: Owen Dylan M. , Magenau Astrid , Williamson David , Gaus Katharina 
Published: June 2012

AbstractRecently developed super‐resolution microscopy techniques are changing our understanding of lipid rafts and membrane organisation in general. The lipid raft hypothesis postulates that cholesterol can drive the formation of ordered domains within the plasma membrane of cells, which may serve as platforms for cell signalling and membrane trafficking. There is now a wealth of evidence for these domains. However, their study has hitherto been hampered by the resolution limit of optical microscopy, making the definition of their properties problematic and contentious. New microscopy techniques circumvent the resolution limit and, for the first time, allow the fluorescence imaging of structures on length scales below 200 nm. This review describes such techniques, particularly as applied to the study of membrane organisation, synthesising newly emerging facets of lipid raft biology into a state‐of‐the art model.Editor's suggested further reading in BioEssays: Super‐resolution imaging prompts re‐thinking of cell biology mechanisms Abstract and Quantitative analysis of photoactivated localization microscopy (PALM) datasets using pair‐correlation analysis Abstract
RNA‐Schalter
Authors: Wittmann Alexander , Süß Beatrix 
Published: June 2012

AbstractEin Ziel der Synthetischen Biologie ist die Entwicklung von neuen Stoffwechselwegen. Wie am Beispiel des Antimalariamittels Artemisinin gezeigt, lassen sich über Mikroorganismen interessante Substanzen für die pharmazeutische und chemische Industrie kostengünstig und ressourcenschonend herstellen. Neben den Genen sind Regulatoren essenzielle Bestandteile dieser neuen Stoffwechselwege. RNA‐Schalter stellen eine neue Klasse an solchen Regulatoren dar. Mithilfe von ligandenbindenden RNA‐Molekülen lassen sich maßgeschneiderte RNA‐Schalter für die Synthetische Biologie entwickeln.
Extremozyme
Authors: Elleuche Skander , Sahm Kerstin , Grote Ralf , Antranikian Garabed 
Published: June 2012

AbstractDie weiße Biotechnologie ist ein hochaktuelles, schnell wachsendes Feld in der angewandten Forschung. Die Bedeutung von Biokatalysatoren für Prozesse in der Chemikalienherstellung, der Lebensmittel‐ und der Textilindustrie sowie im Bereich der Bioraffinerie nimmt rapide zu. Während in der Vergangenheit zumeist Enzyme aus mesophilen Mikroorganismen als Alternative in traditionell chemischen Prozessen eingesetzt wurden, verschiebt sich der Fokus des Interesses zurzeit immer mehr zugunsten von Biokatalysatoren aus extremophilen Mikroben, welche als Extremozyme bezeichnet werden. Mikroorganismen, die beispielsweise aus besonders heißen, sauren oder salzigen Habitaten isoliert wurden, beherbergen einen großen Schatz an industriell nutzbaren Extremozymen. Diese zeigen zumeist optimale Aktivität unter extremen Umweltbedingungen und sind daher für biotechnologische Anwendungen besonders interessant.
Das bakterielle Mobilom
Authors: Schumann Wolfgang 
Published: June 2012

AbstractInzwischen hat man mobile Elemente bei allen Lebewesen nachgewiesen. Sie können bei Säugetieren für bis zu 50% des Genoms codieren und bei Pflanzen bis zu 90%. Sie etablieren sich bei Bakterien als autonom‐replizierende Replicons (Plasmide und Plasmid‐Prophagen) oder sind Bestandteile von Replicons (IS‐Elemente, Transposons, konjugative Transposons, integrative und konjugative Elemente (ICEs), genomische Inseln und Integrons). Warum gibt es überhaupt noch distinkte Bakterien‐Spezies? Offensichtlich sorgen bislang noch unbekannte Mechanismen dafür, dass bestimmte speziesbildende Gene keiner Verbreitung unterliegen.
Radioaktivität – Wirkung auf die Zelle
Authors: Wickert L. 
Published: June 2012

AbstractSolange es die Erde gibt, sind alle auf ihr lebenden Organismen einer natürlichen, radioaktiven Strahlung ausgesetzt. Dem Menschen gelang es durch seine Kenntnisse über den Aufbau der Materie, den natürlichen Vorgang des radioaktiven Zerfalls auf friedliche (Medizin, Energie) und militärische Weise (Atombomben) zu nutzen. Dadurch ist die künstliche, durch den Menschen geschaffene Strahlenbelastung sowie die Menge des radioaktiven “Mülls” in den vergangenen 100 Jahren erheblich gestiegen. Die Nutzung der Kernenergie zeigt sich insbesondere nach Tschernobyl (Russland) und Fukushima (Japan) nicht so beherrschbar wie zu Beginn vermutet. Ein nach wie vor ungelöstes Problem stellt die “Entsorgung” und Lagerung von radioaktiven Materialien dar. Mit der Herstellung und Nutzung radioaktiver Substanzen in großen Mengen hinterlassen wir den nachfolgenden Generationen auf Jahrtausende ein derzeit ungelöstes Problem.
Honigbienen in Entdeckerlaune
Authors: Wendler Silke 
Published: June 2012

AbstractDer Fortbestand eines Bienenvolkes ist abhängig davon, dass Kundschafterbienen immer wieder neue Futterquellen und mögliche Nestplätze ausfindig machen. Eine Forschergruppe um Zhengzheng S. Liang aus Illinois hat sich der Frage gewidmet, warum manche Bienen mehr Entdeckerdrang haben als andere.
Vererbung von Fingerabdruckmerkmalen
Authors: Hauf Fabian 
Published: June 2012

AbstractFingerabdrücke sind einzigartig und dienen daher der Identifikation. Die Daktyloskopie ist stark kriminalistisch geprägt – die Frage einer Vererbung von Fingerabdruckmerkmalen wurde bisher wissenschaftlich wenig untersucht. In der Literatur findet man häufig die – nicht belegte – Hypothese, dass Fingerabdruckmerkmale durch Umgebungseinflüsse und nicht durch Genetik geprägt werden. Die vorliegende Studie beweist jedoch mit statistischen Mitteln, dass ein Einfluss der Genetik auf die Ausprägung von Fingerabdruckmerkmalen stark zu vermuten ist.
Pflanzen bereiten sich auf den abendlichen Angriff von Insekten vor
Authors: Brennicke Axel 
Published: June 2012

AbstractInsekten greifen in der Dämmerung an – das kennen wir von den Mücken und treffen entsprechende Verteidigungsmaßnahmen. Doch auch Pflanzen scheinen sich auf abendliche Attacken vorzubereiten, denn ihre innere Uhr schaltet zum beginnenden Abend automatisch die chemische Abwehr an. Diese jetzt nachgewiesene Steuerung über Hormone belegt einen weiteren Vorteil der inneren Uhr und erklärt, warum viele Gene für die Verteidigung durch diese Uhr beeinflusst werden.
Übersichtsfärbung mit Hämatoxylin und Eosin (H&E)
Authors: Schrödel Andrea 
Published: June 2012

AbstractDie Hämatoxylin‐Eosin‐Färbung (kurz: H&E‐Färbung) ist die bekannteste und am häufigsten genutzte Übersichtsfärbung der Histologie und wird beispielsweise in der Pathologie eingesetzt, um krankhafte Veränderungen in Gewebeproben zu untersuchen.