Foamed Nanocomposites for EMI Shielding Applications

INTRODUCTION : The addition of nanoparticles having specific properties inside a matrix with different properties creates a novel material that exhibits hybrid and even new properties. The nanocomposites presented in this paper combine the properties of foamed polymers (inexpensive, lightweight, easy to mould into any desired shape, etc.) with those of carbon nanotubes (CNTs). The addition of any conductive nanoparticles to an otherwise insulating matrix leads to a significant increase of the electrical conductivity. But CNTs have a very high aspect ratio; a much lower content of CNTs is therefore required to get the same conductivity increase as the one obtained with more compact nanoparticles. This is especially interesting for EMI shielding materials since, as will be explained in further details in this chapter, it is desirable for such materials to have a high conductivity but a low dielectric constant, in order to minimize the electromagnetic power outside the shield casing but also to minimize the power reflected back inside the casing, as is explained in section 2. In particular, two parameters of interest when comparing shielding materials are detailed and discussed. The polymer/CNTs nanocomposites were fabricated and characterized using a two-step diagnostic method. They were first characterized in their solid form, i.e. before the foaming process and the most interesting polymer matrices (with embedded CNTs) could be selected. This way, only the promising blends were foamed, therefore avoiding the unnecessary fabrication of a number of foams. These selected blends were foamed and then characterized. The samples, both solid and foamed, are described and their fabrication processes are briefly explained in section 3 while the characterization methods are shown in section 4. A simple electrical model is given and explained in section 5 and an optimized topology for the foams is also proposed in the second part of the same section. The measurement results for the solids and for the mono-layered and multi-layered foams are summarized and discussed in section 6. They are then compared to results obtained using the electrical model presented in the previous section and they are also correlated to rheological characterizations

Continuous odour measurement from fattening pig units

peer reviewedA study in experimental slatted-system fattening pig units was conducted with the aim of estimating the odour emission factor (in ou/s.pig), which can subsequently be used in dispersion models to assess the odour annoyance zone. Dynamic olfactometry measurements carried out at different development stages of pigs showed a logical trend of the mean predicted odour emission factor with the pig weight. However, the variation within the same weight class was much larger than variation between classes. Possible causes of such variation were identified as the evolution of ventilation rate during the day and the circadian rhythm of pig. To be able to monitor continuously the daily variation of the odour, an electronic nose was used with suitable regression model calibrated against olfactometric measurements. After appropriate validation check, the electronic nose proved to be convenient, as a complementary tool to dynamic olfactometry, to record the daily variation of the odour emission factor in the pig barn. It was demonstrated that, in the controlled conditions of the experimental pens, the daily variation of the odour emission rate could be mainly attributed to the sole influence of the circadian rhythm of pig. As a consequence, determining a representative odour emission factor in a real case cannot be based on a snapshot odour sampling

M & L Jaargang 29/3

Marie-Anne Bru, Anton Ervynck, Doreen Gaublomme, Marie Christine Laleman, Daniel Lievois en Geert Vermeiren - Een stenen vogel: een uniek monument in de Gentse Sint-Pietersabdij. [A Stone bird: a unique monument in the Ghent Saint Peters Abbey.]In de historische kern van Gent zijn archeologen voortdurend druk in de weer. Recente opgravingen op het ceremonieplein brachten een grote stenen plaat mét gegraveerde vogel aan het licht: een bijzondere vondst die meteen heel wat vragen opriep. Het zoeken naar antwoorden werd een uitermate boeiende zoektocht over vakgebieden heen. Of hoe een vakoverschrijdende benadering van een archeologische vondst nieuwe kennis oplevert over onze regio in de late middeleeuwen en de moderne tijden.Anton Ervynck, Daniel Lievois en Baudouin Van den Abeele Gejaagd, gevangen, en uiteindelijk verdwenen: de natuurlijke historie van de Vlaamse kraan. [Hunted, caught and eventually disappeared: the natural history of the crane in Flanders.]In Vlaanderen is de kraanvogel voor de meesten wellicht een nobele onbekende. Ooit was dat anders en kon men de Grus grus terug vinden als gekortwiekt gevogelte op het neerhof, bezocht hij onze meersen en weilanden, was hij jachtbuit van de meest edele valken én een hoogstandje op het laatmiddeleeuwse banket. Een onderzoek van archeologische vondsten, naamgeving, toponiemen en historisch bronnenmateriaal brengt de kraanvogel - als deel van ons erfgoed - terug naar Vlaanderen.Daniel Lievois, Baudouin Van den Abeele en Anton Ervynck De kraanvogel, een krachtig symbool. [The crane, a powerful symbol.]Dat het verhaal van de kraanvogel nog niet is uitverteld bewijst een derde bijdrage in dit M&L nummer. Beladen met symboliek blijkt zijn aanwezigheid in één van de machtigste abdijen van de Lage Landen allerminst een toeval. De talrijke verhalen en mythen over deze soort zijn zo goed als vergeten. Uitkijkend naar zijn terugkeer brengen enkele onderzoekers alvast zoveel mogelijk over het verleden van de kraanvogel in kaart. Een verhaal dat - zonder enige twijfel - nog wordt vervolgdSummar

Front Pediatr

INTRODUCTION: Primary infection or reactivation of Epstein-Barr Virus (EBV) is a significant cause of morbidity and mortality in pediatric kidney transplantation. Valganciclovir (VGC) treatment is recommended for prophylaxis of cytomegalovirus infection, but its role for the prevention of EBV infection remains controversial. PATIENTS AND METHODS: All pediatric kidney transplant recipients aged 4.5 log/ml. Outcomes were compared between patients receiving VGC prophylaxis (group P+) and those not receiving VGC prophylaxis (group P-). RESULTS: A total of 79 patients were included, 57 (72%) in the P+ group and 22 (28%) in the P- group; 25 (31%) were at risk of primary infection and 54 (69%) at risk of reactivation. During the first year post-transplant, the occurrence of severe EBV infection was not different between the P+ group (n = 13, 22.8%) and the P- group (n = 5, 22.7%) (p = 0.99). Among patients at risk of primary infection, the rate of severe EBV infection was not different between the two groups (42.1% in P+ vs. 33.3% in P-). A higher frequency of neutropenia was found in the P+ group (66.6%) than in the P- group (33.4%) (p < 0.01). CONCLUSION: Our observational study suggests no effect of VGC for the prevention of EBV infection in pediatric kidney transplant recipients, irrespective of their EBV status. Adverse effects revealed an increased risk of neutropenia

Spondyloenchondrodysplasia Due to Mutations in ACP5: A Comprehensive Survey

Purpose: Spondyloenchondrodysplasia is a rare immuno-osseous dysplasia caused by biallelic mutations in ACP5. We aimed to provide a survey of the skeletal, neurological and immune manifestations of this disease in a cohort of molecularly confirmed cases. Methods: We compiled clinical, genetic and serological data from a total of 26 patients from 18 pedigrees, all with biallelic ACP5 mutations. Results: We observed a variability in skeletal, neurological and immune phenotypes, which was sometimes marked even between affected siblings. In total, 22 of 26 patients manifested autoimmune disease, most frequently autoimmune thrombocytopenia and systemic lupus erythematosus. Four patients were considered to demonstrate no clinical autoimmune disease, although two were positive for autoantibodies. In the majority of patients tested we detected upregulated expression of interferon-stimulated genes (ISGs), in keeping with the autoimmune phenotype and the likely immune-regulatory function of the deficient protein tartrate resistant acid phosphatase (TRAP). Two mutation positive patients did not demonstrate an upregulation of ISGs, including one patient with significant autoimmune disease controlled by immunosuppressive therapy. Conclusions: Our data expand the known phenotype of SPENCD. We propose that the OMIM differentiation between spondyloenchondrodysplasia and spondyloenchondrodysplasia with immune dysregulation is no longer appropriate, since the molecular evidence that we provide suggests that these phenotypes represent a continuum of the same disorder. In addition, the absence of an interferon signature following immunomodulatory treatments in a patient with significant autoimmune disease may indicate a therapeutic response important for the immune manifestations of spondyloenchondrodysplasia

Emotional Facial Expression Detection in the Peripheral Visual Field

BACKGROUND: In everyday life, signals of danger, such as aversive facial expressions, usually appear in the peripheral visual field. Although facial expression processing in central vision has been extensively studied, this processing in peripheral vision has been poorly studied. METHODOLOGY/PRINCIPAL FINDINGS: Using behavioral measures, we explored the human ability to detect fear and disgust vs. neutral expressions and compared it to the ability to discriminate between genders at eccentricities up to 40°. Responses were faster for the detection of emotion compared to gender. Emotion was detected from fearful faces up to 40° of eccentricity. CONCLUSIONS: Our results demonstrate the human ability to detect facial expressions presented in the far periphery up to 40° of eccentricity. The increasing advantage of emotion compared to gender processing with increasing eccentricity might reflect a major implication of the magnocellular visual pathway in facial expression processing. This advantage may suggest that emotion detection, relative to gender identification, is less impacted by visual acuity and within-face crowding in the periphery. These results are consistent with specific and automatic processing of danger-related information, which may drive attention to those messages and allow for a fast behavioral reaction