What is linguistic morphology?. 1. Morphology: basic notions. 2. Morphological analysis. Word formation. 3. Derivation. 4. Compounding. Inflection. 5. Inflection. 6. Inflectional systems. Interfaces. ...7. The interface between morphology and phonology. 8. Morphology and syntax: demarcation, interaction and interface. 9. Morphology and semantics. Morphology and mind. 10. Morphology and psycholinguistics. 11. Morphology and language change. References. Language index. Subject index.
The selection of an appropriate non-hazardous solvent or solvent system is essential to determine the rheological properties and electrospinnability of the solution, the productivity, and the ...morphology of nanofibres. In this study, poly lactic acid (PLA) solutions were prepared in various pure solvents and binary-solvent systems to investigate the effect of different solution properties on nanofibre morphology and diameter. Viscosity, conductivity and surface tension of each solution were measured. Nanofibre morphology was observed by scanning electron microscopy (SEM). Of all the solvent systems used acetone/dimethylformamide gave the highest fibre productivity and finest defect-free nanofibres. Therefore this solvent system was studied in more detail, varying the solvent ratio. Also the polymer concentration in this solvent system was varied to investigate the effect on nanofibre morphology and solution properties. Morphological investigations were done in correlation with rheological measurements: beaded nanofibrous structures were collected from solutions with concentration around the critical chain entanglement concentration (Ce), while defect-free nanofibres were produced when the concentration was increased to about twice the entanglement concentration. Further investigation of the effect of the PLA concentration on the elastic (G′) and the plastic (G″) moduli showed a sudden increase of the elastic moduli (G′) at the critical chain entanglement concentration. The results showed that the solvent properties, boiling point, viscosity, conductivity and surface tension, have a significant effect on process productivity, morphology and diameter distribution of the PLA nanofibres.
Display omitted
•Acetone/dimethylformamide as new suitable solvent system for PLA nanofibres.•Solvent boiling point exerts a strong effect on nanofibre morphology and diameter.•Relationship C–η was weaker for the unentangled regime compared to other results.•Relationship C–η was in agreement for the entangled regime.
Polymersolarzellen mit Heteroübergangsarchitektur (“bulk‐heterojunction polymer solar cell”, BHJ‐PSC) wurden zwei Jahrzehnte lang vor allem auf solche Materialmischungen hin untersucht, bei denen der ...Elektronendonor ein Polymer und der Elektronenakzeptor ein Fulleren ist. Dies änderte sich erst in neuerer Zeit mit der Einführung von PSCs ohne Fullerenakzeptor. Innerhalb kürzester Zeit haben sich diese fullerenfreien PSCs rasant weiterentwickelt. Fullerenfreie BHJ‐PSCs erreichen mittlerweile einen weit höheren Wirkungsgrad von über 15 % als die effizientesten Fulleren‐PSCs. Vor allem die reinen Polymersolarzellen (“all‐polymer solar cells”, APSCs), bei denen der Heteroübergang aus einem Polymer als Donor und einem Polymer als Akzeptor gebildet wird, finden steigendes Interesse. Sie bieten: 1) eine einstellbare hohe Lichtabsorption durch das Polymer‐Donor/Polymer‐Akzeptor‐Paar; 2) robuste Morphologien des BHJ‐Films; 3) Kompatibilität mit großformatiger und großflächiger Fertigung; 4) eine gute Langzeitstabilität der Zelle gegenüber Umwelt‐ und mechanischer Beanspruchung. Dieser Kurzaufsatz beschreibt die Möglichkeiten und Chancen der APSCs. Er zeigt auf, welche Polymere sich als Bauelemente eignen und wie sich deren Leistungsfähigkeit noch weiter optimieren lässt. Herausforderungen, die für kommerzielle Anwendungen weiter bestehen, werden ebenfalls erörtert.
APSCs bieten alles: Rationaler Aufbau und verbesserte Morphologie bei gleichzeitig hoher Absorption und Stabilität machen Polymersolarzellen (APSCs) zu einer hochinteressanten Technologie. Dieser Kurzaufsatz beschreibt die Möglichkeiten und Chancen der APSCs. Er zeigt auf, welche Polymere sich als Bauelemente eignen und wie sich deren Leistungsfähigkeit noch weiter optimieren lässt. Herausforderungen, die für kommerzielle Anwendungen weiter bestehen, werden ebenfalls erörtert.
Résumé : Cette étude décrit les concepts du développement durable en koulango. En effet, depuis des décennies, tous les pays du monde, singulièrement ceux de l’Afrique, aspirent à un développement ...tant humain qu’économique. A ce titre, chaque pays définit un programme de développement lié au besoin de la communauté. Pour y parvenir, ce programme prend en compte les questions de l’environnement et du bien-être social. Ainsi, il a été prescrit des principes de base qui tiennent compte du respect du cadre de vie communautaire. Ces principes se traduisent en objectif que chaque état se doit de promouvoir. Pour ce fait, la question principale réside dans le choix de mots rendant compte des concepts relatifs au développement durable. A partir de la traduction et de la transcription, cette étude met en exergue les procédés et les mécanismes de l’expression de ces concepts en koulango.
Organometal trihalide perovskite based solar cells have exhibited the highest efficiencies to‐date when incorporated into mesostructured composites. However, thin solid films of a perovskite absorber ...should be capable of operating at the highest efficiency in a simple planar heterojunction configuration. Here, it is shown that film morphology is a critical issue in planar heterojunction CH3NH3PbI3‐xClx solar cells. The morphology is carefully controlled by varying processing conditions, and it is demonstrated that the highest photocurrents are attainable only with the highest perovskite surface coverages. With optimized solution based film formation, power conversion efficiencies of up to 11.4% are achieved, the first report of efficiencies above 10% in fully thin‐film solution processed perovskite solar cells with no mesoporous layer.
The critical role of perovskite morphology in planar heterojunction perovskite solar cells is probed and understood. Dewetting of perovskite films is minimized, to achieve uniform 100% coverage perovskite layers. Solution cast planar heterojunction solar cells with efficiencies of up to 11.4% are fabricated, a new record for such cells with no mesoporous layer.
Visible-light-responsive photocatalysts can directly harvest energy from solar light, offering a desirable way to solve energy and environment issues. Here, we show that one-dimensional ...poly(diphenylbutadiyne) nanostructures synthesized by photopolymerization using a soft templating approach have high photocatalytic activity under visible light without the assistance of sacrificial reagents or precious metal co-catalysts. These polymer nanostructures are very stable even after repeated cycling. Transmission electron microscopy and nanoscale infrared characterizations reveal that the morphology and structure of the polymer nanostructures remain unchanged after many photocatalytic cycles. These stable and cheap polymer nanofibres are easy to process and can be reused without appreciable loss of activity. Our findings may help the development of semiconducting-based polymers for applications in self-cleaning surfaces, hydrogen generation and photovoltaics.
Membrane distillation (
MD) is one of the
non-isothermal membrane separation processes used in various applications such desalination, environmental/waste cleanup, food, etc. It is known since 1963 ...and is still being developed at laboratory stage for different purposes and not fully implemented in industry. An abrupt increase in the number of papers on
MD membrane engineering (i.e. design, fabrication and testing in
MD) is seen since only 6
years ago. The present paper offers a comprehensive
MD state-of-the-art review covering a wide range of commercial membranes,
MD membrane engineering, their
MD performance, transport mechanisms, experimental and theoretical modeling of different
MD configurations as well as recent developments in
MD. Improved
MD membranes with specific morphology, micro- and nano-structures are highly demanded. Membranes with different pore sizes, porosities, thicknesses and materials as well as novel structures are required in order to carry out systematic
MD studies for better understanding mass transport in different
MD configurations, thereby improving the
MD performance and looking for
MD industrialization.
A 3D N‐doped graphene foam with a 6.8 at% nitrogen content is prepared by annealing a freeze‐dried graphene oxide foam in ammonia. It is used as an anode in sodium ion batteries to deliver a high ...initial reversible capacity of 852.6 mA h g‐1 at 1 C between 0.02 and 3 V with a long‐term retention of 69.7% after 150 cycles.
PDF
