Stichwort, Stichwortliste und Eigennamen in elexiko

elexiko (www.elexiko.de) ist ein am Institut für Deutsche Sprache in Mannheim entstehendes Online-Wörterbuch zur deutschen Sprache. Die methodische Basis für die redaktionelle, lexikografische Erarbeitung von Wortartikeln ist das Prinzip der Korpusbasiertheit. Voraussetzung für dessen methodische Umsetzung ist, dass für jedes Stichwort (und seine Lesarten) Belege in ausreichender Anzahl und Qualität im elexiko-Korpus vorhanden sind. Um das zu gewährleisten wurde auch die Stichwortliste komplett neu erstellt, und zwar auf der Basis von Korpora des geschriebenen Deutsch seit 1946. Im ersten Teil des Beitrags werden grundsätzliche Gedanken zur Erarbeitung einer adäquaten Stichwortkonzeption im Rahmen eines Online-Wörterbuches dargelegt, Sonderfälle und Ausnahmen vorgestellt sowie die Vorgehensweise bei der korpusbasierten Erstellung der elexiko-Stichwortliste skizziert

Effect of crosslinking stage on photocrosslinking of benzophenone functionalized poly(2-ethyl-2-oxazoline) nanofibers obtained by aqueous electrospinning

In this study, benzophenone was introduced onto partially hydrolyzed poly(2-ethyl-2-oxazoline) (PEtOx-PEI) to prepare a poly(2-ethyl-2-oxazoline)-benzophenone (PEtOx-BP) copolymer, which was used to produce water stable nanofibers via aqueous electrospinning and photocrosslinking. Three different ultraviolet (UV) irradiation methods, i.e. pre-crosslinking before electrospinning, in-situ crosslinking during electrospinning and post-crosslinking after electrospinning, were used to prepare crosslinked nanofibers. The influence of UV-irradiation at these different stages of the nanofiber production process was investigated in terms of alterations in viscosity, nanofiber morphology and water stability of the fibers. It was shown that pre-crosslinking the polymer solutions had a great influence on the solution viscosity which could both positively or negatively alter the stability of the electrospinning process. Whereas the strategy of crosslinking nanofibers during the production process did not lead to uniform nor water-stable nanofibers, the pre-crosslinking and post-crosslinking strategies greatly increased the water stability of the nanofibers. In both techniques the crosslinking density and therefore water solubility can be easily tuned by manipulating the polymer concentration, UV-irradiation time and membrane thickness. Complete insolubility, i.e. the formation of crosslinked networks, was achieved by the post-cross linking strategy. This work provides straightforward methods to increase the water stability of the PEtOx nanofibers, which will definitely be of great value to biomedical applications such as drug delivery and tissue engineering

Plasma dye coating as straightforward and widely applicable procedure for dye immobilization on polymeric materials

Here, we introduce a novel concept for the fabrication of colored materials with significantly reduced dye leaching through covalent immobilization of the desired dye using plasmagenerated surface radicals. This plasma dye coating (PDC) procedure immobilizes a preadsorbed layer of a dye functionalized with a radical sensitive group on the surface through radical addition caused by a short plasma treatment. The non-specific nature of the plasmagenerated surface radicals allows for a wide variety of dyes including azobenzenes and sulfonphthaleins, functionalized with radical sensitive groups to avoid significant dye degradation, to be combined with various materials including PP, PE, PA6, cellulose, and PTFE. The wide applicability, low consumption of dye, relatively short procedure time, and the possibility of continuous PDC using an atmospheric plasma reactor make this procedure economically interesting for various applications ranging from simple coloring of a material to the fabrication of chromic sensor fabrics as demonstrated by preparing a range of halochromic materials

Käytettävyystestaus osana verkko-oppimisympäristön kehitystä

Opinnäytetyön tavoitteena oli tuottaa Opintoverkko Oy:lle käytettävyystutkimus sisältäen testaussuunnitelman ja testitapauksia, jotka aidot käyttäjät suorittivat. Testattava järjestelmä on verkko-opiskeluympäristö nimeltä Opintoverkko 2, joka on käytössä useissa organisaatioissa. Järjestelmä on tarkoitettu opettajien ja oppilaiden väliseen kommunikointiin ja sen pääasiallinen tarkoitus on toimia tiedonvälityskanavana. Opinnäytetyössä esiintyvä testaussuunnitelma sisältää Opintoverkko 2:n testaukseen liittyvät tiedot. Testitapauksia on luotu sekä peruskäytäjän että ylläpitäjän oikeuksilla ja pääasialliset teemat niissä keskittyvät tiedonvälitykseen, lukuoikeuksiin ja interaktiivisiin toimintoihin. Opinnäytetyön näkökulma on nimenomaan käytettävyyden varmistaminen. Teoriaosuudessa tutkitaan ensin käytettävyystestausta ilmiönä ja pohditaan miksi testaus on tärkeää. Sen jälkeen perehdytään käytettävyyteen määritelmänä sekä sen eri metodeihin. Testaussuunnitelman laatimisessa käytettiin monipuolista teoriapohjaa käytettävyydestä ja hyödynnettiin omaa aiempaa kokemusta järjestelmien testaamisesta. Testaussuunnitelmassa on lueteltu kaikki olennaiset asiat testaukseen liittyen ja itse testitapaukset on myös sisällytetty opinnäytetyöhön kokonaisuudessaan. Tulevaisuudessa Opintoverkko Oy voi hyödyntää käytettävyystestauksesta saatuja tuloksia uudemman oppimisympäristönsä kehitykseen ja soveltaa myös muihin projekteihinsa. Testaussuunnitelmaa ja testitapauksia on kuitenkin oleellista muokata tasaisin väliajoin järjestelmän ominaisuuksien kehittyessä.The goal of this Bachelor’s thesis was to produce a usability test for Opintoverkko Ltd. The usabil-ity test includes a testing plan and test cases that were tested with real users. The system that was tested is an e-learning platform named Opintoverkko 2 that is used by many organizations. The system is designed for communication between teachers and students and its main function is to act as a platform for transferring information. The testing plan present in the thesis includes all the information regarding the testing of Opintoverkko 2. The test cases are created both with the permissions of an administrator and a basic user and the main themes of are focused on communication, reading permissions and inter-active functions. The main angle of the thesis is ensuring usability. In the theoretical part of the thesis usability and the reasoning behind it is first studied as a phenomenon. It is followed by fa-miliarization of usability and different expressions and methods for it. A versatile amount of theory and basis of usability and personal experience with system testing was used to form the testing plan. The testing plan includes all essential information regarding the testing and the test cases themselves have also been included in the Thesis. The results gained from the usability test can be used in the future by Opintoverkko Oy to develop and further improve their newer version of the learning platform and be applied to other projects as well. However, it is essential that the testing plan and test cases are edited at regular intervals as the features of the system are updated

Waterborne electrospinning of poly(N-isopropylacrylamide) by control of environmental parameters

With increasing toxicity and environmental concerns, electrospinning from water, i.e., waterborne electrospinning, is crucial to further exploit the resulting nanofiber potential. Most water-soluble polymers have the inherent limitation of resulting in water-soluble nanofibers, and a tedious chemical cross-linking step is required to reach stable nanofibers. An interesting alternative route is the use of thermoresponsive polymers, such as poly(N-isopropylacrylamide) (PNIPAM), as they are water-soluble beneath their lower critical solution temperature (LCST) allowing low-temperature electrospinning while the obtained nanofibers are water-stable above the LCST. Moreover, PNIPAM nanofibers show major potential to many application fields, including biomedicine, as they combine the well-known on off switching behavior of PNIPAM, thanks to its LCST, with the unique properties of nanofibers. In the present work, based on dedicated turbidity and rheological measurements, optimal combinations of polymer concentration, environmental temperature, and relative humidity are identified allowing, for the first time, the production of continuous, bead-free PNIPAM nanofibers electrospun from water. More specifically, PNIPAM gelation was found to occur well below its LCST at higher polymer concentrations leading to a temperature regime where the viscosity significantly increases without compromising, the polymer solubility. This opens up the ecological, water-based production of uniform PNIPAM nanofibers that are stable in water at temperatures above PNIPAM's LCST, making them suitable for various applications, including drug delivery and switchable cell culture substrates

Nanofibers with a tunable wettability by electrospinning and physical crosslinking of poly(2-n-propyl-2-oxazoline)

This work shows the design of highly porous membranes with tunable wettability based on poly(2-n-propyl-2-oxazoline) (PnPrOx) nanofibers. Wicking and advanced contact angle experiments demonstrate the high potential for applications requiring specific interactions with aqueous media. PnPrOx is a popular member among the biocompatible poly(2-oxazoline)s due to its thermoresponsiveness in aqueous solutions, enabling the production of ‘smart materials’. On material level, however, many interesting properties of this polymer remain undiscovered. Electrospinning is an ideal technique to transfer the properties observed in solutions to end-material properties, as the polymer is processed into highly porous, nanofibrous membranes. PnPrOx' electrospinnability is here investigated in environmentally friendly ethanol/water solvent systems, ensuring industrial scalability. The nanofibrous membranes show increased hydrophobicity exhibiting the rose-petal effect. Upon functionalization with tannic acid, the hydrophobic membranes are transformed into hydrophilic nanofibers showing water-stability in both fresh and salty water, even below the polymer cloud point temperature. By varying the tannic acid amount, the hydrophilicity can be fine-tuned as the contact area between water droplets and surface, the rate and manner of water uptake and the extent of the rose-petal effect can be manipulated easily. Hence an interesting material is designed for applications in which water caption and transport are important