Diffusion phenomena in chemically stabilized multilayer structures

Multilayered thin film structures are widely applied as reflective coatings for optical elements in the extreme ultraviolet wavelength regime. In this thesis we investigate\ud the structural and chemical changes that occur in Mo/Si based multilayers as a result of radiation induced thermal loads and other heating schemes. This thesis addresses thermally induced diffusion in such multilayers, focussing on reaction mechanisms at the interfaces and how these are modified in the presence of a diffusion barrier layer.\ud To allow these studies, a new, in-situ X-ray diffraction method is introduced to analyse diffusion induced interface growth and measure diffusion speeds in Mo/Si multilayers during thermal annealing. This method can determine the change in the interface thickness at picometer accuracy. Because of this high accuracy it is possible to study diffusion at relatively low temperatures. A diffusion-reaction model was developed to describe the interface growth.\ud The diffusion in multilayers is shown to be dependent on the structure of all the layers as well as on the chemical interactions with barrier layer materials. In particular, the crystallinity of the Mo layer (crystalline or quasi-amorphous) has a large influence on the diffusion speed. The structure and density of the B4C diffusion barrier layers have a large influence on the diffusion coefficient. Furthermore it is shown that B4C also forms molybdenum boride compounds during annealing, which reduce the diffusion rate. In conclusion, the diffusion properties of thin film multilayer structures are determined by both the structure and the chemical interactions of the individual (barrier-)layers.\ud The damage mechanisms of these layered structures by intense femtosecond pulses are also investigated, to find a possible difference in damage mechanism between continuous heat loads and ultrafast pulsed heat loads. This investigation was performed on MoN/SiN multilayers. We find that the damage mechanisms for annealing and pulsed irradiation are fundamentally the same. In both cases, the MoN layer dissociates and N2 gas is released, which subsequently forms bubbles in the MoN layer which may lead to delamination

Annually repeated influenza vaccination improves humoral responses to several influenza virus strains in healthy elderly

The benefit of annually repeated influenza vaccination on antibody formation is still under debate. In this study the effect of annually repeated influenza vaccination on haemagglutination inhibiting (HI) antibody formation in the elderly is investigated. Between 1990 and 1993 healthy young and elde

Galacto-Oligosaccharides as an Anti-Infective and Anti-Microbial Agent for Macrolide-Resistant and -Sensitive Mycoplasma pneumoniae.

The worldwide increase in the incidence of antibiotic resistance of the atypical bacterium Mycoplasma pneumoniae (MP) challenges the treatment of MP infections, especially in children. Therefore, alternative strategies for the treatment of MP infections are warranted. Galacto- and fructo-oligosaccharides (GOS and FOS) are a specific group of complex carbohydrates that were recently shown to possess direct anti-pathogenic properties. In this study, we assessed whether GOS and FOS exert anti-microbial and anti-infective effects against MP and, especially, macrolide-resistant MP (MRMP) in vitro. The MIC values of GOS for MP and MRMP were 4%. In contrast, the MIC values of FOS for both MP and MRMP were 16%. A time-kill kinetic assay showed that FOS possess bacteriostatic properties, while for GOS, a bactericidal effect against MP and MRMP was observed after 24 h at a concentration of 4x MIC. In co-cultures with human alveolar A549 epithelial cells, GOS killed adherent MP and MRMP and also concentration-dependently inhibited their adherence to A549 cells. Further, GOS suppressed (MR)MP-induced IL-6 and IL-8 in A549 cells. None of the aforementioned parameters were affected when FOS were added to these co-cultures. In conclusion, the anti-infective and anti-microbial properties of GOS could provide an alternative treatment against MRMP and MP infections

Institutionalisering van maatschappelijke ondernemingsverslaggeving

Maatschappelijke ondernemingsverslaggeving (MOV) heeft zijn plaats gevonden en ontleent bestaansrecht aan het afleggen van verantwoording aan de maatschappij. Dat suggereert dat er een verband bestaat tussen onderneming en maatschappij. In dit onderzoek wordt dat verband beschreven, meer specifiek tussen de omvang van MOV en economische instituties. Dit artikel vult het begrip economische instituties in met marktvrijheid en corporate governancesystemen. De resultaten suggereren een negatief verband tussen MOV en marktvrijheid en een diffuus verband tussen MOV en corporate governancesystemen. Hiermee wordt verondersteld dat MOV deels is geïnstitutionaliseerd, ofwel dat ondernemingen ten minste blijk geven van het besef van die institutionalisering

Strijdende of complementaire doelstellingen van de jaarrekening?

Medio 2006 is in het kader van het convergentie- en verbeterproject van de Financial Accounting Standards Board en de International Accounting Standards Board het eerste Discussion Paper over het verbeterde conceptual framework gepubliceerd. Hierin komen de doelstelling van financiële verslaggeving en de kwalitatieve kenmerken aan bod. Bij de bespreking van de doelstelling van financiële verslaggeving staat de decision usefulness-benadering centraal. Traditioneel wordt evenwel ook de stewardship-benadering van belang geacht. De vraag is of deze twee doelstellingen, enerzijds de decision usefulness-benadering en anderzijds de stewardshipbenadering, strijdig of complementair zijn. Geconcludeerd wordt dat de stewardship-benadering vooral is gekoppeld aan de juridisch gerichte, enkelvoudige jaarrekening en dat de economisch gerichte, geconsolideerde jaarrekening nuttig is voor de decision usefulness-benadering

Personeelsaangelegenheden in het bestuursverslag

Met ingang van verslagjaar 2005 zijn ondernemingen die onder titel 9 BW vallen, verplicht om niet alleen over financiële, maar ook over niet-financiële indicatoren te rapporteren. Dit op grond van de wijziging in artikel 2:391 lid 1 BW betreffende de inhoud van het jaarverslag (hierna bestuursverslag). Ten opzichte van de oudere versie van het wetsartikel wordt nu ook expliciet informatie met betrekking tot personeelsaangelegenheden verlangd. Is hier sprake van een toename van de vergelijkbaarheid van informatieverschaffing met betrekking tot personeel

Reducing interaction in simultaneous paired stimulation with CI.

In this study simultaneous paired stimulation of electrodes in cochlear implants is investigated by psychophysical experiments in 8 post-lingually deaf subjects (and one extra subject who only participated in part of the experiments). Simultaneous and sequential monopolar stimulation modes are used as references and are compared to channel interaction compensation, partial tripolar stimulation and a novel sequential stimulation strategy named phased array compensation. Psychophysical experiments are performed to investigate both the loudness integration during paired stimulation at the main electrodes as well as the interaction with the electrode contact located halfway between the stimulating pair. The study shows that simultaneous monopolar stimulation has more loudness integration on the main electrodes and more interaction in between the electrodes than sequential stimulation. Channel interaction compensation works to reduce the loudness integration at the main electrodes, but does not reduce the interaction in between the electrodes caused by paired stimulation. Partial tripolar stimulation uses much more current to reach the needed loudness, but shows the same interaction in between the electrodes as sequential monopolar stimulation. In phased array compensation we have used the individual impedance matrix of each subject to calculate the current needed on each electrode to exactly match the stimulation voltage along the array to that of sequential stimulation. The results show that the interaction in between the electrodes is the same as monopolar stimulation. The strategy uses less current than partial tripolar stimulation, but more than monopolar stimulation. In conclusion, the paper shows that paired stimulation is possible if the interaction is compensated