Optimal liquid acquisition device screen weave for a liquid hydrogen fuel depot

This paper presents the rationale for choosing the optimal screen type for a fully robust screen channel liquid acquisition device (LAD) to be implemented into future in-space liquid hydrogen (LH₂) fuel depots. Typical Dutch Twill, Plain Dutch, Twilled Square, and Plain Square weaves are initially considered for comparison. From the set of influential performance parameters from Hartwig and Darr [1], bubble point pressure and flow-through-screen (FTS) pressure drop are combined to define a critical mass flux used to make general comparisons between screens. Based off the minimum bubble point pressure to maintain adequate phase separation against adverse depot acceleration levels, the five finest Dutch Twill screens are down selected for the depot. Along with secondary parameters such as wicking rate and screen compliance, a minimum screen area is defined to select the optimal mesh. Results here indicate that the 450 × 2750 Dutch Twill mesh may be the optimal screen weave for a future LH₂ fuel depot.     

Development and characterization of a biocompatible OH-modified copolymer based on polyurethane

Different polyurethanes were synthesized by varying the diol as well as the diisocyanate components and chain extenders. Polyurethanes with OH-groups were obtained by photo- and thermoinitiation of the radical polymerization of hydroxy alkyl acrylates in the presence of the polyurethanes. The polymers were evaluated with respect to their biocompatibility by measuring the cell spreading, the rates of DNA- and protein synthesis and the swelling behaviour. The differences in the surfaces and the bulks between the selected basic polyurethane and the functionalized modification were determined and characterized by XPS, FTIR-ATR and ¹³C-FT-NMR-spectroscopy. The mechanical data of Tecoflex EG 60D® and Pellethane 2363–80AE® were compared with the data of the synthesized polyurethanes.     

Production and Characterization of Peptide Antibodies to the C-Terminal of Frameshifted Calreticulin Associated with Myeloproliferative Diseases

Myeloproliferative Neoplasms (MPNs) constitute a group of rare blood cancers that are characterized by mutations in bone marrow stem cells leading to the overproduction of erythrocytes, leukocytes, and thrombocytes. Mutations in calreticulin (CRT) genes may initiate MPNs, causing a novel variable polybasic stretch terminating in a common C-terminal sequence in the frameshifted CRT (CRTfs) proteins. Peptide antibodies to the mutated C-terminal are important reagents for research in the molecular mechanisms of MPNs and for the development of new diagnostic assays and therapies. In this study, eight peptide antibodies targeting the C-terminal of CRTfs were produced and characterised by modified enzyme-linked immunosorbent assays using resin-bound peptides. The antibodies reacted to two epitopes: CREACLQGWTE for SSI-HYB 385-01, 385-02, 385-03, 385-04, 385-07, 385-08, and 385-09 and CLQGWT for SSI-HYB 385-06. For the majority of antibodies, the residues Cys¹, Trp⁹, and Glu¹¹ were essential for reactivity. SSI-HYB 385-06, with the highest affinity, recognised recombinant CRTfs produced in yeast and the MARIMO cell line expressing CRTfs when examined in Western immunoblotting. Moreover, SSI-HYB 385-06 occasionally reacted to CRTfs from MPN patients when analysed by flow cytometry. The characterized antibodies may be used to understand the role of CRTfs in the pathogenesis of MPNs and to design and develop new diagnostic assays and therapeutic targets.     

Magnetic resonance butterfly coils: Design and application for hyperpolarized C studies

Hyperpolarized ¹³C magnetic resonance spectroscopy in pig models enables cardiac metabolism assessment and provides a powerful tool for heart physiology studies, although the low molar concentration of derivate metabolites gives rise to technological limitations in terms of data quality. The design of dedicated coils capable of providing large field of view with high Signal-to-Noise Ratio (SNR) data is of fundamental importance.     

Microstructure and transport properties of porous building materials

To successfully predict the performance of building materials exposed to a degradative environment, transport properties must be either measured or estimated. The development of relationships between microstructure and transport properties for these materials should allow accurate prediction of the latter and an increased understanding of how microstructure influences transport. Here, two microstructural characterization techniques, mercury intrusion porosimetry and scanning electron microscopy, are combined with computer modelling techniques to compute the vapor diffusivity and air permeability of three building materials commonly exposed in building facades, two types of brick and a natural sandstone. In general, the computed values compare favorably to those measured experimentally, thus demonstrating the capability of employing microstructural characterization to predict transport properties.

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Résumé Pour obtenir une prédiction fiable des performances des matériaux de construction exposés à un environnement agressif, leurs propriétés de transport doivent être soit mesurées soit estimées. Le développement de relations entre la microstructure et les propriétés de transport devrait permettre une prédiction exacte de ces dernières et une meilleure compréhension de l’influence de la microstructure sur le transfert. Dans cet article, deux techniques de caractérisation de la microstructure (porosimétrie au mercure et microscopie électronique à balayage) sont combinées avec des techniques de simulation par ordinateur pour calculer la diffusivité à la vapeur d’eau et la perméabilité à l’air de trois matériaux de construction traditionnellement utilisés en facades: deux types de brique et un grès naturel. En général, les valeurs calculées sont proches de celles mesurées expérimentalement. Ces résultats démontrent les possibilités des outils de caractérisation de la structure pour prédire les propriétés de transport.

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Editorial note: Mr. Daniel Quenard is a RILEM Senior Member and a member of TC 123-MME on the Use of Microstructural Models and Expert systems for Cemenitious Materials. He and Mr. K. Xu work at the CSTB (Centre Scientifique et Technique du Batiment), France, a RILEM Titular Member. Mr. Dale P. Bentz is a RILEM Senior Member and participates in the work of TC 159-ETC (Engineering of the Interfacial Transition Zone in Cementitious Composites). He and Mr. Nicos Martys work at the National Institute of Standards and Technology (NIST), USA, a RILEM Titular Member.     

Wireless microservers

With Bluetooth components getting smaller and cheaper, we might soon integrate wireless microservers into all kinds of electronic devices. The authors explore application of a general-purpose, pluggable microserver, based on wireless application protocol and Bluetooth technology, for remote control purposes.     

On the performance bounds of motion-compensated deinterlacing

The terms ‘proscan up-conversion’ or ‘deinterlacing’ stand for algorithms for the conversion of interlaced image sequences into progressive format by interpolating the lines which are missing due to interlaced scanning. Although deinterlacing is already known to improve TV image quality, such techniques will become even more important in future. Firstly, standard interlaced image sequences will be increasingly processed and displayed on computer platforms and thus usually require progressive scanning and an increased temporal resolution. Secondly, the emerging market of light valve projection equipment demands high-quality proscan up-conversion since the image quality of these display techniques relies heavily on the light efficiency of non-interlaced scanning. By describing deinterlacing as a problem of linear prediction theory, this paper derives upper MSE performance bounds for these algorithms. Thus, a theoretical framework is provided which allows to analyse the effects of various parameters like motion vector inaccuracy, temporal integration and memory constraints on the efficiency of motion-compensated deinterlacing. It is, for example, shown that these algorithms can be very sensitive to motion vector inaccuracies especially if the image sequence is recorded with very short exposure time. Finally, it is briefly demonstrated that the presented analysis can easily be extended to the case of field- and frame-rate up-conversion of interlaced (‘100 Hz’) and non-interlaced image sequences.     

Quantification of quality parameters for reliable evaluation of green rooibos (Aspalathus linearis)

An LC-MS/UV-Vis method was developed for the reliable identification of the most relevant flavonoids occurring in rooibos. The amounts of the dihydrochalcones aspalathin, (2′,3,4,4′,6′-pentahydroxy-3-C-β-d-glucopyranosyldihydrochalcone), nothofagin (2′,3,4′,6′-tetrahydroxy-3-C-β-d-glucopyranosyldihydrochalcone) and other flavonoids were determined in unfermented and fermented samples, collected at different locations in South Africa. Generally, a substantial loss of both dihydrochalcones was observed after the fermentation process. An NIR spectroscopic method was developed to discriminate between unfermented and fermented rooibos and to predict the aspalathin content in unfermented rooibos. The total antioxidative activity, determined according to the ABTS^·+ scavenging method, was found to correlate very good with the aspalathin content in the unfermented plant material (R²=0.812).