Materials analysis of fluorocarbon films for MEMS applications

In this paper the results of the materials analysis of fluorocarbon (FC) films are presented. The properties of the fluorocarbon films are comparable to those of polytetrafluoroethylene (PTFE), better known under the trademarks such as teflon and fluon. The properties of PTFE are desirable for MEMS applications and enable new designs, new applications and new technological processing routes for microsystems. Therefore, FC films have a tremendous potential for MEMS applications. Furthermore, FC films can easily be deposited via spin coating, e-beam evaporation, in conventional reactive ion etchers and in plasma-enhanced deposition chambers using a carbonhydrotrifluoride plasma facilitating the use of the films for micro electro-mechanical structures. The films deposited in a reactive ion etcher are extremely chemical resistant. The X-ray photoelectron spectroscopy (XPS) analyses results are presente

Fabrication and capillary filling of sub-10nm nanochannels

Keywords: Nanochannels, capillarity, viscosit

Deemo: a new technology for the fabrication of microstructures

The recent innovations in dry etching make it a promising technology for the fabrications of micromoulds. The high aspect ratios, directional freedom, low roughness, high etch rates and high selectivity with respect to the mask material allow a versatile fabrication process of micromoulds for subsequent electroplating and embossing, as is demonstrated with the DEEMO process. DEEMO is an English acronym and stands for Dry Etching, Electroplating and Moulding

Multi-silicon ridge nanofabrication by repeated edge lithography

We present a multi-Si nanoridge fabrication scheme and its application in nanoimprint\ud lithography (NIL). Triple Si nanoridges approximately 120 nm high and 40 nm wide separated\ud by 40 nm spacing are fabricated and successfully applied as a stamp in nanoimprint lithography.\ud The fabrication scheme, using a full-wet etching procedure in combination with repeated edge\ud lithography, consists of hot H3PO4 acid SiNx retraction etching, 20% KOH Si etching, 50% HF\ud SiNx retraction etching and LOCal Oxidation of Silicon (LOCOS). Si nanoridges with smooth\ud vertical sidewalls are fabricated by using Si 110 substrates and KOH etching. The presented\ud technology utilizes a conventional photolithography technique, and the fabrication of multi-Si\ud nanoridges on a full wafer scale has been demonstrated

Characteristics of Staphylococcus aureus isolated from acute, sub-acute and sub-clinical staphylococcosis in rabbits

[EN] Staphylococcus aureus bacteria isolated from different clinical presentations of staphylococcosis in rabbits were examined for the production of various virulence factors using biochemical and immunological tests. In the total of 106 S. aureus isolates; toxic shock syndrome toxin-1, staphylococcal enterotoxin-C, DNase, ¿-haemolysin, ß-haemolysin, ¿-haemolysin, protein A and clumping factor were observed with a frequency of 33.2, 16.98, 83.96, 69.81, 36.79, 100, 78.30 and 54.72 percent, respectively. No SE-A, SE-B and SE-D producing isolates were recovered in this study. All the S. aureus isolates from acute staphylococcosis produced TSST-1, SE-C and protein A. While ¿¿haemolysin and clumping factor were not detected in any acute isolates, these factors were observed at a relatively higher frequency in isolates from sub-acute and sub-clinical staphylococcosis. Coagulase type III was observed more predominantly with a frequency of 45.28%, while coagulase types V and VII were not observed in any isolate. Most of the virulence factors belonged to coagulase type III followed by type VI. TSST-1 and SE-C along with coagulase types III and V Icould be correlated with the acute and sub-acute staphylococcal infections in rabbits in this study.Tirpude, RJ.; Batra, H. (2012). Characteristics of Staphylococcus aureus isolated from acute, sub-acute and sub-clinical staphylococcosis in rabbits. World Rabbit Science. 20(4):215-221. doi:10.4995/wrs.2012.1203SWORD21522120

Effect of Thermal Gradients on the Electromigration Lifetime in Power Electronics

The combined effects of electromigration and thermomigration are studied. Significantly shorter electromigration lifetimes are observed in the presence of a temperature gradient. This cannot be explained by thermomigration only, but is attributed to the effect of temperature gradient on electromigration-induced failures

MHC-linked and un-linked class I genes in the wallaby

Background: MHC class I antigens are encoded by a rapidly evolving gene family comprising classical and non-classical genes that are found in all vertebrates and involved in diverse immune functions. However, there is a fundamental difference between the organization of class I genes in mammals and non-mammals. Non-mammals have a single classical gene responsible for antigen presentation, which is linked to the antigen processing genes, including TAP. This organization allows co-evolution of advantageous class Ia/ TAP haplotypes. In contrast, mammals have multiple classical genes within the MHC, which are separated from the antigen processing genes by class III genes. It has been hypothesized that separation of classical class I genes from antigen processing genes in mammals allowed them to duplicate. We investigated this hypothesis by characterizing the class I genes of the tammar wallaby, a model marsupial that has a novel MHC organization, with class I genes located within the MHC and 10 other chromosomal locations. Results: Sequence analysis of 14 BACs containing 15 class I genes revealed that nine class I genes, including one to three classical class I, are not linked to the MHC but are scattered throughout the genome. Kangaroo Endogenous Retroviruses (KERVs) were identified flanking the MHC un-linked class I. The wallaby MHC contains four non-classical class I, interspersed with antigen processing genes. Clear orthologs of non-classical class I are conserved in distant marsupial lineages. Conclusion: We demonstrate that classical class I genes are not linked to antigen processing genes in the wallaby and provide evidence that retroviral elements were involved in their movement. The presence of retroviral elements most likely facilitated the formation of recombination hotspots and subsequent diversification of class I genes. The classical class I have moved away from antigen processing genes in eutherian mammals and the wallaby independently, but both lineages appear to have benefited from this loss of linkage by increasing the number of classical genes, perhaps enabling response to a wider range of pathogens. The discovery of non-classical orthologs between distantly related marsupial species is unusual for the rapidly evolving class I genes and may indicate an important marsupial specific function

Construction of a quality index for granules produced by fluidized bed technology and application of the correspondence analysis as a discriminant procedure

The production of granules by wet granulation in a fluidized bed was assessed after the construction of a quality index based on a file of attributes (relevant factors). These attributes are combined by a methodology relying on Correspondence Analysis, as a discriminant procedure, using two extreme simulated active vectors representing, respectively, the best and the worst cases for the granules quality output (“bad” and “good” pole). From those, a single continuous synthetic variable – the quality index – can be produced referring to a more significant set of samples. As an application of the methodology, the work compares the quality of granules produced at a laboratory scale and a pilot scale. The factors contribution to the bad or good pole allowed the identification of the most relevant factors that affect the quality of the granules. The factors studied, according to a center of gravity design, included formulation (solubility of a drug, different grades of polyvinylpyrrolidone, the polarity of the granulation solution) and processing factors (the rate of administration of the granulation solution, the atomizing air pressure and the fluidizing air rate). Granules were evaluated for production yield, drug content, size, densities (true, bulk and tapped), friability, flowability and compressibility. The study has emphasized the differences between the laboratory and pilot scales and the relative importance of each factor for the quality of the granules produced

Houting in het IJsselmeergebied. Een uitgestorven vis terug?

De oorspronkelijke populatie Noordzeehouting (Coregonus oxyrhynchus) van het Rijnstroomgebied wordt beschouwd als uitgestorven sinds 1939. In 1992 is begonnen met een grootschalig uitzetprogramma van houting in Duitsland op basis van een Deense entpopulatie van de rivier de Vidå die uitmondt in de Noordzee. Hoewel de taxonomische status van houting en andere coregoniden (waaronder grote marene) nog veel onduidelijkheden bevat en aan wetenschappelijke discussie onderhevig is, is deze Deense populatie waarschijnlijk het meest verwant aan de oorspronkelijke houtingpopulatie Voor een adequate bescherming van deze houtingpopulatie is het van belang hoe deze populatie zich verder ontwikkelt, hoe trekpatronen zich ontwikkelen in het Rijnstroomgebied en welke habitats en migratiemogelijkheden daarbij van belang zijn en hoe grootschalige milieuveranderingen en klimaatveranderingen van invloed kunnen zijn op het toekomstig succes van de houting in het Rijnstroomgebied