Effects of inorganic nitrogen (NH4Cl) and biodegradable organic carbon (CH3COONa) additions on a pilot-scale seawater biofilter

Biofilters degrade only a small fraction of the natural organic matter (NOM) contained in seawater which is the leading cause of biofouling in downstream processes. This work studies the effects of chemical additions on NOM biodegradation by biofilters. In this work, biofiltration of seawater with an empty bed contact time (EBCT) of 6 min and a hydraulic loading rate of 10 m h-1 reduces the biological oxygen demand (BOD7) by 8%, the dissolved organic carbon (DOC) by 6% and the UV absorbance at 254 nm (A254) by 7%. Different amounts of ammonium chloride are added to the seawater (up to twice the total dissolved nitrogen in untreated seawater) to study its possible effect on the removal of NOM by a pilot-scale biofilter. Seawater is amended with different amounts of easily biodegradable dissolved organic carbon (BDOC) supplied as sodium acetate (up to twice the DOC) for the same purpose. The results of this work reveal that the ammonium chloride additions do not significantly affect NOM removal and the sodium acetate is completely consumed by the biofiltration process. For both types of chemical additions, the BOD7, DOC and A254 in the outlet stream of the biofilter are similar to the values for the untreated control. These results indicate that this biofilter easily removes the BDOC from the seawater when the EBCT is not above 6 min. Furthermore, nitrogen does not limit the NOM biodegradation in seawater under these experimental conditions.

Organisational Buying Decision Process for Biodegradable Implants

Työn tavoitteena oli selvittää organisaation ostopäätösprosessi, kun tuotteina ovat biohajoavat kasvo- ja kallokirurgian implantit. Ensin selvitettiin biohajoavien implanttien markkinapotentiaalia, biohajoavien materiaalien lisäksi implanttien valmistuksessa käytettäviä muita materiaaleja sekä implanteilta vaadittavia ominaisuuksia kirjallisuuden ja internetin sekä asiantuntijahaastatteluiden avulla. Kirjallisuuden avulla selvitettiin myös organisaatioiden ostopäätösprosessien yleisiä piirteitä ja vaiheita. Biohajoavien kasvo- ja kallokirurgian implanttien ostopäätösprosessia tutkittiin kirjallisen kyselytutkimuksen avulla, joka oli suunnattu alan asiantuntijoille Euroopassa, Yhdysvalloissa sekä Kanadassa. Tutkimuksessa selvitettiin mm. tärkeimpiä käytettävien implanttien materiaalivalintaan vaikuttavia kriteereitä, ostopäätösprosessiin osallistuvia organisaation jäseniä, sekä heidän roolejaan päätöksenteossa, implantteja koskevan informaation etsintää sekä ostopäätösprosessin vaiheita. Kirjallisuudesta, internetistä, asiantuntijahaastatteluista ja kyselytutkimuksesta saatu tieto koottiin vuokaaviomalliksi, joka kuvaa kasvo- ja kallokirurgian implanttien ostopäätösprosessia organisaatioissa. Lopuksi esitettiin myös ehdotuksia markkinointisuunnitelmaan sekä jatkotutkimusehdotukset.

Stability of hydrogenated nanocrystalline silicon thin-film transistors

Hydrogenated nanocrystalline silicon thin-films were obtained by catalytic chemical vapour deposition at low substrate temperatures (150°C) and high deposition rates (10 Å/s). These films, with crystalline fractions over 90%, were incorporated as the active layers of bottom-gate thin-film transistors. The initial field-effect mobilities of these devices were over 0.5 cm 2/V s and the threshold voltages lower than 4 V. In this work, we report on the enhanced stability of these devices under prolonged times of gate bias stress compared to amorphous silicon thin-film transistors. Hence, they are promising candidates to be considered in the future for applications such as flat-panel displays.

Compositional influence on the electrical performance of zinc indium tin oxide transparent thin-film transistors

In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies. In thin-film transistors this effect leads to a higher threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the fieldeffect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3 eV from the conduction band edge that could be attributed to oxygen vacancies.

Peripheral Nerve Repair: Multimodal Comparison of the Long-Term Regenerative Potential of Adipose Tissue-Derived Cells in a Biodegradable Conduit.

Tissue engineering is a popular topic in peripheral nerve repair. Combining a nerve conduit with supporting adipose-derived cells could offer an opportunity to prevent time-consuming Schwann cell culture or the use of an autograft with its donor site morbidity and eventually improve clinical outcome. The aim of this study was to provide a broad overview over promising transplantable cells under equal experimental conditions over a long-term period. A 10-mm gap in the sciatic nerve of female Sprague-Dawley rats (7 groups of 7 animals, 8 weeks old) was bridged through a biodegradable fibrin conduit filled with rat adipose-derived stem cells (rASCs), differentiated rASCs (drASCs), human (h)ASCs from the superficial and deep abdominal layer, human stromal vascular fraction (SVF), or rat Schwann cells, respectively. As a control, we resutured a nerve segment as an autograft. Long-term evaluation was carried out after 12 weeks comprising walking track, morphometric, and MRI analyses. The sciatic functional index was calculated. Cross sections of the nerve, proximal, distal, and in between the two sutures, were analyzed for re-/myelination and axon count. Gastrocnemius muscle weights were compared. MRI proved biodegradation of the conduit. Differentiated rat ASCs performed significantly better than undifferentiated rASCs with less muscle atrophy and superior functional results. Superficial hASCs supported regeneration better than deep hASCs, in line with published in vitro data. The best regeneration potential was achieved by the drASC group when compared with other adipose tissue-derived cells. Considering the ease of procedure from harvesting to transplanting, we conclude that comparison of promising cells for nerve regeneration revealed that particularly differentiated ASCs could be a clinically translatable route toward new methods to enhance peripheral nerve repair.

Amorphous silicon thin film solar cells deposited entirely by Hot-Wire Chemical Vapour Deposition at low temperature (<150 ºC)

Amorphous silicon n-i-p solar cells have been fabricated entirely by Hot-Wire Chemical Vapour Deposition (HW-CVD) at low process temperature < 150 °C. A textured-Ag/ZnO back reflector deposited on Corning 1737F by rf magnetron sputtering was used as the substrate. Doped layers with very good conductivity and a very less defective intrinsic a-Si:H layer were used for the cell fabrication. A double n-layer (μc-Si:H/a-Si:H) and μc-Si:H p-layer were used for the cell. In this paper, we report the characterization of these layers and the integration of these layers in a solar cell fabricated at low temperature. An initial efficiency of 4.62% has been achieved for the n-i-p cell deposited at temperatures below 150 °C over glass/Ag/ZnO textured back reflector.

Electronic transport in low temperature nanocrystalline silicon thin-film transistors obtained by Hot-Wire CVD

Hydrogenated nanocrystalline silicon (nc-Si:H) obtained by hot-wire chemical vapour deposition (HWCVD) at low substrate temperature (150 °C) has been incorporated as the active layer in bottom-gate thin-film transistors (TFTs). These devices were electrically characterised by measuring in vacuum the output and transfer characteristics for different temperatures. The field-effect mobility showed a thermally activated behaviour which could be attributed to carrier trapping at the band tails, as in hydrogenated amorphous silicon (a-Si:H), and potential barriers for the electronic transport. Trapped charge at the interfaces of the columns, which are typical in nc-Si:H, would account for these barriers. By using the Levinson technique, the quality of the material at the column boundaries could be studied. Finally, these results were interpreted according to the particular microstructure of nc-Si:H.

Microcrystalline silicon thin film transistors obtained by Hot-Wire CVD

Polysilicon thin film transistors (TFT) are of great interest in the field of large area microelectronics, especially because of their application as active elements in flat panel displays. Different deposition techniques are in tough competition with the objective to obtain device-quality polysilicon thin films at low temperature. In this paper we present the preliminary results obtained with the fabrication of TFT deposited by hot-wire chemical vapor deposition (HWCVD). Some results concerned with the structural characterization of the material and electrical performance of the device are presented.

Thin Film Transistors obtained by Hot-Wire CVD

Hydrogenated microcrystalline silicon films obtained at low temperature (150-280°C) by hot wire chemical vapour deposition at two different process pressures were measured by Raman spectroscopy, X-ray diffraction (XRD) spectroscopy and photothermal deflection spectroscopy (PDS). A crystalline fraction >90% with a subgap optical absortion 10 cm -1 at 0.8 eV were obtained in films deposited at growth rates >0.8 nm/s. These films were incorporated in n-channel thin film transistors and their electrical properties were measured. The saturation mobility was 0.72 ± 0.05 cm 2/ V s and the threshold voltage around 0.2 eV. The dependence of their conductance activation energies on gate voltages were related to the properties of the material.

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Recension

Hollywood Films in the Non-Western World: What Are the Criteria Followed by the Chinese Government When Choosing Hollywood Film Imports?

This dissertation argues that the Government of the People’s Republic of China, when it made the decision to import a quota of Hollywood films in 1994 to revive the failing domestic film industry, had different possible criteria in mind. This project has studied four of them: first, importing films that gave a negative image of the United States; second, importing films that featured Chinese talent or themes; third, importing films that were box office hits in the United States; and fourth, importing films with a strong technological innovation ingredient. In order to find out the most important criteria for the Chinese Government, this dissertation offers a dataset that analyzes a population of 262 Hollywood films released in the PRC between 1994 and 2010. For each unit, a method has been developed to compile data that will determine whether the film reflects any of the four criteria, and findings in the form of yearly percentages have been drawn. Results show that, out of the four studied criteria, the two predominant reasons for China to import films were technological innovation and box office hits. This tells us that, at this point, the Chinese Government shows more interest in obtaining big revenues and learning from technically innovative American films than in delivering underlying political messages. This dissertation contributes to the existing literature by analyzing the content of all the films imported by China between 1994 and 2010, while integrating in the analysis variables based on the existing knowledge.

The Transnational Zombie: Postcolonial Memory and Rage in the Recent European Horror Film

An ever increasing number of films, books, and scholarly works dealing with the undead have appeared in the last decade, making the zombie the very incarnation of American popular culture on a global scale. In this chapter I show that the zombie is also a surprisingly complex sign for transnational movement and multidirectional cultural flow. While the zombie may appear as the very epitome of American cultural production and influence, a mindless movie monster born of a vapid stream of Hollywood B-horror, the zombie has a rich transnational history and an eloquent figurative resonance that have fed into its current ubiquity as cultural sign. This chapter reviews that history and then examines some of the ways that the zombie figure has traveled between the Caribbean, where it emerged, the United States, where it was translated into a film device of startling pathos and horror, and Europe, to which it owes some of its most interesting recent innovations.

La controverse avant le film : quelle politique pour Good Night, And Good Luck ?

This article aims to explain how newspapers commented on the movie Good Night, and Good Luck before its release. The media coverage anticipated George Clooney's film as a partisan attack launched against George W. Bush's policy since 9/11. Clooney advocates another reading: the historic confrontation between journalist Edward Murrow and Senator Joseph McCarty permits to reflect on the crucial role that the media play for democracy. Such reflection tries to prevent the dividing of the public sphere into antagonistic camps opposing "friends" to "foes," a division that undermines the possibility of a true pluralism. Our socio-semiotic analysis will focus on the critical work accomplished by the media, and on the way that work determines the collective meaning of a cultural object. Simultaneously, we will discuss the necessary conditions for pluralism in a public sphere.