Zur Verwendung von Medien im Deutschunterricht in den Klassen 8 und 9

Syftet med avhandlingen är att undersöka vilka medier som används i tyskundervisningen i årskurs 8 och 9 i tre olika högstadier i närheten av Vasa, nämligen Vasa övningsskola, Borgaregatans skola samt Högstadiet i Petalax. Dessutom undersöks även varför samt hur ofta dessa medier används. Undersökningsmaterialet består av intervjuer med tysklärarna i dessa tre högstadier samt en enkät, som alla elever som valt tyska som tillvalsämne i högstadierna fyllt i. I teoridelen diskuteras begreppet medium samt olika typer av medier, som primära, sekundära, tertiära och kvartära medier samt akustisk-auditiva, visuella, audiovisuella och nya symmedier, dvs. internet och dator. Därefter behandlas även vilka typer av adressater det finns samt begreppet mediekompetens, liksom de fyra olika användningsdimensionerna enligt Baacke. Slutligen diskuteras enskilda medier i undervisningen samt läroplanen och främmande språk på B2-nivå. Undersökningen visade att det enligt både eleverna och lärarna används många typer av medier i tyskundervisningen, bl. a. läroböcker, arbetsblad, internet, filmer, musik och drama. En del av orsakerna varför dessa medier används var att de fungerar som en gemensam referensram för båda parterna. De är konkreta för eleverna och är dessutom sedan tidigare bekanta för dem. Eleverna kom även med förslag på medier som kunde användas mera sällan eller oftare i undervisningen. Fastän det t.ex. nämndes att läroböckerna är grunden i undervisningen var en del av eleverna missnöjda med detta, eftersom undervisningen i längden blir enformig ifall endast dessa medier används. Därför önskade sig en stor del av dem att mera digitala medier skulle kunna användas i undervisningen, såsom Skype, internet, epost, filmer, smartphones osv. så att de skulle få använda språket mera och t.o.m. kunna komma i kontakt med tyskspråkiga även i vardagen.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

The Water Uptake of Plasticized Poly(vinyl chloride) Solid‐Contact Calcium‐Selective Electrodes

A hyphenated method based on FTIR‐ATR and electrochemical impedance spectroscopy has been applied to simultaneously measure the water uptake, changes in the bulk resistance and potential of plasticized poly(vinyl chloride) (PVC) based Ca 2+ ‐selective coated‐wire (CaCWE) and solid‐contact electrodes (CaSCISEs). Most of the water uptake of the ion‐selective membranes (ISMs) used in both electrode types took place within the first 9 h in 10 −3  M CaCl 2 showing good correlation with the stabilization of the individual electrode potentials. The bulk resistance of the ISMs of the CaCWEs and the CaSCISEs with poly(3‐octylthiophene) (POT) as the solid‐contact (SC) increased most during the first 18 h in 10 −3  M CaCl 2 . The increase in the resistance was found to be related to the exchange of K + for Ca 2+ in the ISM and the formation of the Ca 2+ ‐ionophore (ETH 5234) complex having a lower diffusivity than the free K + ions. In contrary to previously published results on silicone rubber based SCISEs and poly(methyl methacrylate):poly( n ‐decyl methacrylate) membranes containing POT, the plasticized PVC‐based CaSCISEs with POT as the SC had a higher water uptake than the CaCWEs. The CaSCISEs had a detection limit of 2×10 −8  M Ca 2+ and a good potential reproducibility of 148.9±1.0 mV in 10 −4  M CaCl 2 .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86920/1/2156_ftp.pd

Demagnetization of Quantum Dot Nuclear Spins: Breakdown of the Nuclear Spin Temperature Approach

The physics of interacting nuclear spins arranged in a crystalline lattice is typically described using a thermodynamic framework: a variety of experimental studies in bulk solid-state systems have proven the concept of a spin temperature to be not only correct but also vital for the understanding of experimental observations. Using demagnetization experiments we demonstrate that the mesoscopic nuclear spin ensemble of a quantum dot (QD) can in general not be described by a spin temperature. We associate the observed deviations from a thermal spin state with the presence of strong quadrupolar interactions within the QD that cause significant anharmonicity in the spectrum of the nuclear spins. Strain-induced, inhomogeneous quadrupolar shifts also lead to a complete suppression of angular momentum exchange between the nuclear spin ensemble and its environment, resulting in nuclear spin relaxation times exceeding an hour. Remarkably, the position dependent axes of quadrupolar interactions render magnetic field sweeps inherently non-adiabatic, thereby causing an irreversible loss of nuclear spin polarization.Comment: 15 pages, 3 figure

Optical Detection of a Single Nuclear Spin

We propose a method to optically detect the spin state of a 31-P nucleus embedded in a 28-Si matrix. The nuclear-electron hyperfine splitting of the 31-P neutral-donor ground state can be resolved via a direct frequency discrimination measurement of the 31-P bound exciton photoluminescence using single photon detectors. The measurement time is expected to be shorter than the lifetime of the nuclear spin at 4 K and 10 T.Comment: 4 pages, 3 figure

Nanoscale Potentiometry

Potentiometric sensors share unique characteristics that set them apart from other electrochemical sensors. Potentiometric nanoelectrodes have been reported and successfully used for many decades, and we review these developments. Current research chiefly focuses on nanoscale films at the outer or the inner side of the membrane, with outer layers for increasing biocompatibility, expanding the sensor response, or improving the limit of detection (LOD). Inner layers are mainly used for stabilizing the response and eliminating inner aqueous contacts or undesired nanoscale layers of water. We also discuss the ultimate detectability of ions with such sensors and the power of coupling the ultra-low LODs of ion-selective electrodes with nanoparticle labels to give attractive bioassays that can compete with state-of-the-art electrochemical detection

High resolution nuclear magnetic resonance spectroscopy of highly-strained quantum dot nanostructures

Much new solid state technology for single-photon sources, detectors, photovoltaics and quantum computation relies on the fabrication of strained semiconductor nanostructures. Successful development of these devices depends strongly on techniques allowing structural analysis on the nanometer scale. However, commonly used microscopy methods are destructive, leading to the loss of the important link between the obtained structural information and the electronic and optical properties of the device. Alternative non-invasive techniques such as optically detected nuclear magnetic resonance (ODNMR) so far proved difficult in semiconductor nano-structures due to significant strain-induced quadrupole broadening of the NMR spectra. Here, we develop new high sensitivity techniques that move ODNMR to a new regime, allowing high resolution spectroscopy of as few as 100000 quadrupole nuclear spins. By applying these techniques to individual strained self-assembled quantum dots, we measure strain distribution and chemical composition in the volume occupied by the confined electron. Furthermore, strain-induced spectral broadening is found to lead to suppression of nuclear spin magnetization fluctuations thus extending spin coherence times. The new ODNMR methods have potential to be applied for non-invasive investigations of a wide range of materials beyond single nano-structures, as well as address the task of understanding and control of nuclear spins on the nanoscale, one of the central problems in quantum information processing

Solid-state reference electrodes based on carbon nanotubes and polyacrylate membranes

A novel potentiometric solid-state reference electrode containing single-walled carbon nanotubes as the transducer layer between a polyacrylate membrane and the conductor is reported here. Single-walled carbon nanotubes act as an efficient transducer of the constant potentiometric signal originating from the reference membrane containing the Ag/AgCl/Cl− ions system, and they are needed to obtain a stable reference potentiometric signal. Furthermore, we have taken advantage of the light insensitivity of single-walled carbon nanotubes to improve the analytical performance characteristics of previously reported solid-state reference electrodes. Four different polyacrylate polymers have been selected in order to identify the most efficient reservoir for the Ag/AgCl system. Finally, two different arrangements have been assessed: (1) a solid-state reference electrode using photo-polymerised n-butyl acrylate polymer and (2) a thermo-polymerised methyl methacrylate:n-butyl acrylate (1:10) polymer. The sensitivity to various salts, pH and light, as well as time of response and stability, has been tested: the best results were obtained using single-walled carbon nanotubes and photo-polymerised n-butyl acrylate polymer. Water transport plays an important role in the potentiometric performance of acrylate membranes, so a new screening test method has been developed to qualitatively assess the difference in water percolation between the polyacrylic membranes studied. The results presented here open the way for the true miniaturisation of potentiometric systems using the excellent properties of single-walled carbon nanotubes