Die Großstadt als Gegner? : Zur Wahrnehmung Berlins in Literatur, Film und Hörspiel der späten Weimarer Republik

Tässä tutkielmassa tarkastellaan, miten Berliinin suurkaupunki vaikutti Weimarin tasavallan loppuaikoina yksilöön. Tutkimusaineistona on Alfred Döblinin romaani Berlin Alexanderplatz sekä Walter Ruttmannin elokuva Berlin. Die Sinfonie der Großstadt ja kuunnelma Weekend. Teoreettisena taustana hyödynnetään kulttuuri- ja mediahistorian mentaliteetti- ja sosiaalihistoriaa. Aihetta käsitellään myös historiallis-temaattisesta lähtökohdasta, eli työssä tutkitaan todellisen Berliinin asemaa kyseisenä aikana, modernin metropolin olemusta, modernin ajan murrosvaihetta sekä uusasiallisen taidesuuntauksen vaikutusta teoksiin. Weimarin tasavallan aikana Saksassa elettiin murroksen keskellä. Toisaalta yhteiskunta oli poliittisesti pirstoutunut ja taloudellisesti epävakaa, mutta toisaalta kulttuurielämä oli lyhyen aikaa rikasta. Suurkaupungin asukkailla oli enemmän vapaa-aikaa ja mahdollisuuksia toteuttaa itseään omassa ympäristössään. Toisaalta ajan ristiriitaisuus kuitenkin vaikeutti yksilöllisen elämäntavan toteutumista; ihmiset odottivat murroskauden päättymiseltä materiaalista tyydytystä, jolloin henkiselle kehitykselle jäi vähän tilaa. Tärkein kysymyksenasettelu koskee suurkaupungin roolia oman aikansa tuotteena: missä määrin kaupunki oli ihmisen todellinen vastustaja ja missä määrin sen asema oli kuviteltua? Todellisen Berliinin suhdetta reflektoidaan fiktiiviseen suurkaupunkiympäristöön. Ensin tarkastellaan Berliiniä toimijana murroskaudella ja sitten käsitellään ajan ja tilan havainnointia. Koska teokset ovat fiktiivisiä, erityisen tarkastelun kohteena on todellisuuden, fiktion ja simulaation suhde. Tässä yhteydessä tarkastellaan myös kaupungin ja maaseudun välistä problematiikkaa. Kolmannessa osassa esille nousee yksilön ja massan välinen suhde, joka sekin vaikuttaa ihmisen ja suurkaupungin väliseen vastakkainasetteluun. Ilmensikö koneiden ja liikenteen dominoiva asema futuristista asetelmaa? Lisäksi käsitellään alamaailman ja kultaisen 20-luvun välistä kuilua. Kaikkia kolmea teosta yhdistää 24 tunnin aikakäsite; ajalla on selkeästi rajattu alku ja loppu, ja myös tilan käsite on tarkastelussa tärkeä. Kaikissa teoksissa on hyödynnetty montaasitekniikkaa. Kohtaukset vaihtuvat hyvinkin nopeasti, jolloin lukija, katsoja tai kuulija vieraantuu varsinaisesta kohteestaan. Montaasi vaikuttaa ratkaisevasti myös kaupungin ja yksilön suhteen kuvaukseen. Suurkaupungista muotoutuu lähes hirviömäinen, personifioitu subjekti, joka konemaisella olemuksellaan pyrkii nujertamaan pienen ihmisen. Döblinin romaanissa kertoja toimii ikään kuin yksilöä vastaan liittämällä kerronnan väliin uutisaiheita, säätiedotuksia ja kohtalokertomuksia. Elokuvassa ja kuunnelmassa teknologisen kehityksen ihannointi on noussut etualalle: ihmiset muistuttavat sekä yksilöinä että massana koneita, jotka liikkuvat hektisen mekaanisesti eteenpäin kuin liikennevälineet. He eivät kyseenalaista ympäristöään eivätkä koe olevansa oravanpyörässä. Romaanin päähenkilö on heijastanut omat pelkonsa konkreettisesti suurkaupungin infrastruktuuriin, kerrostaloihin, jotka tuntuvat kaatuvan hänen päälleen. Yksilöllinen kehitys on vaarassa pysähtyä, sillä koneistuminen tekee yksilöistä massaa. Elokuvassa ja kuunnelmassa kamppailu suurkaupunkiorganismin ja ihmisten välillä jatkuu, mutta romaanissa kamppailu päättyy päähenkilön parantumiseen. Hänestä tulee mallikansalainen - vaiennettu ja kuuliainen. Kaikkien kolmen teoksen hahmoja kuvataan modernin ajan uhreina. Heiltä puuttuu mekanismi, jolla he voisivat käsitellä kokonaisuuksia. Modernin ajan hahmojen elämä on lopulta kuin tanssia tulivuoren päällä - epävarmaa ja riskialtista.

Mannans as film formers and emulsion stabilizers

Mannans are abundant plant polysaccharides found in the endosperm of certain leguminous seeds (guar gum galactomannan, GG; locust bean gum galactomannan, LBG), in the tuber of the konjac plant (konjac glucomannan, KGM), and in softwoods (galactoglucomannan, GGM). This study focused on the effects of the chemical structure of mannans on their film-forming and emulsion-stabilizing properties. Special focus was on spruce GGM, which is an interesting new product from forest biorefineries. A plasticizer was needed for the formation of films from mannans other than KGM and the optimal proportion was 40% (w/w of polymers) glycerol or sorbitol. Galactomannans with lower galactose content (LBG, modified GG) produced films with higher elongation at break and tensile strength. The mechanical properties of GG-based films were improved by decreasing the degree of polymerization of the polysaccharide with moderate mannanase treatments. The improvement of mechanical properties of GGM-based films was sought by blending GGM with each of poly(vinyl alcohol) (PVOH), corn arabinoxylan (cAX), and KGM. Adding other polymers increased the elongation at break of GGM blend films. The tensile strength of films increased with increasing amounts of PVOH and KGM, but the effect of cAX was the opposite. Dynamic mechanical analysis showed two separate loss modulus peaks for blends of GGM and PVOH, but a single peak for all other films. Optical and scanning electron microscopy confirmed good miscibility of GGM with cAX and KGM. In contrast, films blended from GGM and PVOH showed phase separation. GGM and KGM were mixed with cellulose nanowhiskers (CNW) to form composite films. Addition of CNW to KGM-based films induced the formation of fiberlike structures with lengths of several millimeters. In GGM-based films, rodlike structures with lengths of tens of micrometers were formed. Interestingly, the notable differences in the film structure did not appear to be related to the mechanical and thermal properties of the films. Permeability properties of GGM-based films were compared to those of films from commercial mannans KGM, GG, and LBG. GGM-based films had the lowest water vapor permeability when compared to films from other mannans. The oxygen permeability of GGM films was of the same magnitude as that of commercial polyethylene / ethylene vinyl alcohol / polyethylene laminate film. The aroma permeability of GGM films was low. All films were transparent in the visible region, but GGM films blocked the light transmission in the ultraviolet region of the spectra. The stabilizing effect of GGM on a model beverage emulsion system was studied and compared to that of GG, LBG, KGM, and cAX. In addition, GG was enzymatically modified in order to examine the effect of the degree of polymerization and the degree of substitution of galactomannans on emulsion stability. Use of GGM increased the turbidity of emulsions both immediately after preparation and after storage of up to 14 days at room temperature. GGM emulsions had higher turbidity than the emulsions containing other mannans. Increasing the storage temperature to +45 ºC led to rapid emulsion breakdown, but a decrease in storage temperature increased emulsion stability after 14 days. A low degree of polymerization and a high degree of substitution of the modified galactomannans were associated with a decrease in emulsion turbidity.

Atomic Layer Deposition of Electroluminescent ZnS, SrS, and BaS Thin Films

The light emitted by flat panel displays (FPD) can be generated in many different ways, such as for example alternating current thin film electroluminescence (ACTFEL), liquid crystal display (LCD), light emitting diode (LED), or plasma display panel (PDP) technologies. In this work, the focus was on ACTFEL devices and the goal was to develop new thin film processes for light emitting materials in ACTFEL devices. The films were deposited with the atomic layer deposition (ALD) method, which has been utilized in the manufacturing of ACTFEL displays since the mid-1980s. The ALD method is based on surface-controlled self-terminated reactions and a maximum of one layer of the desired material can be prepared during one deposition cycle. Therefore, the film thickness can be controlled simply by adjusting the number of deposition cycles. In addition, both large areas and deep trench structures can be covered uniformly. During this work, new ALD processes were developed for the following thin film materials: BaS, CuxS, MnS, PbS, SrS, SrSe, SrTe, SrS1-xSex, ZnS, and ZnS1-xSex. In addition, several ACTFEL devices were prepared where the light emitting material was BaS, SrS, SrS1-xSex, ZnS, or ZnS1-xSex thin film that was doped with Ce, Cu, Eu, Mn, or Pb. The sulfoselenide films were made by substituting the elemental selenium for sulfur on the substrate surface during film deposition. In this way, it was possible to replace a maximum of 90% of the sulfur with selenium, and the XRD analyses indicated that the films were solid solutions. The polycrystalline BaS, SrS, and ZnS thin films were deposited at 180-400, 120-460, and 280-500 °C, respectively, and the processes had a wide temperature range where the growth rate of the films was independent of the deposition temperature. The electroluminescence studies showed that the doped sulfoselenide films resulted in low emission intensity. However, the emission intensities and emission colors of the doped SrS, BaS, and ZnS films were comparable with those found in earlier studies. It was also shown that the electro-optical properties of the different ZnS:Mn devices were different as a consequence of different ZnS:Mn processes. Finally, it was concluded that because the higher deposition temperature seemed to result in a higher emission intensity, the thermal stability of the reactants has a significant role when the light emitting materials of ACTFEL devices are deposited with the ALD method.

Si, CdTe and CdZnTe radiation detectors for imaging applications

The structure and operation of CdTe, CdZnTe and Si pixel detectors based on crystalline semiconductors, bump bonding and CMOS technology and developed mainly at Oy Simage Ltd. And Oy Ajat Ltd., Finland for X- and gamma ray imaging are presented. This detector technology evolved from the development of Si strip detectors at the Finnish Research Institute for High Energy Physics (SEFT) which later merged with other physics research units to form the Helsinki Institute of Physics (HIP). General issues of X-ray imaging such as the benefits of the method of direct conversion of X-rays to signal charge in comparison to the indirect method and the pros and cons of photon counting vs. charge integration are discussed. A novel design of Si and CdTe pixel detectors and the analysis of their imaging performance in terms of SNR, MTF, DQE and dynamic range are presented in detail. The analysis shows that directly converting crystalline semiconductor pixel detectors operated in the charge integration mode can be used in X-ray imaging very close to the theoretical performance limits in terms of efficiency and resolution. Examples of the application of the developed imaging technology to dental intra oral and panoramic and to real time X-ray imaging are given. A CdTe photon counting gamma imager is introduced. A physical model to calculate the photo peak efficiency of photon counting CdTe pixel detectors is developed and described in detail. Simulation results indicates that the charge sharing phenomenon due to diffusion of signal charge carriers limits the pixel size of photon counting detectors to about 250 μm. Radiation hardness issues related to gamma and X-ray imaging detectors are discussed.

The Path to a Porous Semiconductor Multilayer

Thin films are the basis of much of recent technological advance, ranging from coatings with mechanical or optical benefits to platforms for nanoscale electronics. In the latter, semiconductors have been the norm ever since silicon became the main construction material for a multitude of electronical components. The array of characteristics of silicon-based systems can be widened by manipulating the structure of the thin films at the nanoscale - for instance, by making them porous. The different characteristics of different films can then to some extent be combined by simple superposition. Thin films can be manufactured using many different methods. One emerging field is cluster beam deposition, where aggregates of hundreds or thousands of atoms are deposited one by one to form a layer, the characteristics of which depend on the parameters of deposition. One critical parameter is deposition energy, which dictates how porous, if at all, the layer becomes. Other parameters, such as sputtering rate and aggregation conditions, have an effect on the size and consistency of the individual clusters. Understanding nanoscale processes, which cannot be observed experimentally, is fundamental to optimizing experimental techniques and inventing new possibilities for advances at this scale. Atomistic computer simulations offer a window to the world of nanometers and nanoseconds in a way unparalleled by the most accurate of microscopes. Transmission electron microscope image simulations can then bridge this gap by providing a tangible link between the simulated and the experimental. In this thesis, the entire process of cluster beam deposition is explored using molecular dynamics and image simulations. The process begins with the formation of the clusters, which is investigated for Si/Ge in an Ar atmosphere. The structure of the clusters is optimized to bring it as close to the experimental ideal as possible. Then, clusters are deposited, one by one, onto a substrate, until a sufficiently thick layer has been produced. Finally, the concept is expanded by further deposition with different parameters, resulting in multiple superimposed layers of different porosities. This work demonstrates how the aggregation of clusters is not entirely understood within the scope of the approximations used in the simulations; yet, it is also shown how the continued deposition of clusters with a varying deposition energy can lead to a novel kind of nanostructured thin film: a multielemental porous multilayer. According to theory, these new structures have characteristics that can be tailored for a variety of applications, with precision heretofore unseen in conventional multilayer manufacture.