Towards the understanding of plasma polymer film behaviour in ethanol: A multi-technique investigation

Plasma polymer films (PPFs) of allylamine are prepared varying the mean power injected in the plasma (P_mean). The PPF behaviour in ethanol is studied through the analysis of the PPF physico-chemistry and the composition of the resulting ethanol solutions. By Visible light Spectroscopic Ellipsometry (VISSE), it is observed that the well-known decrease of the PPF thickness (Δd) upon immersion decreases as a function of P_mean. This behaviour is attributed to an increase of the PPF cross-linking density (χ). By means of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and further statistical processing of the data by principal component analysis (PCA), we propose a method to discriminate the samples according to χ. A significant increase in the PPF oxygen content is also observed after immersion which is ascribed to reaction between ethanol molecules and trapped radicals of the PPF network. On the other hand, taking into account the specificities of the gas chromatography–mass spectrometry (GC–MS) method, the resulting ethanol solutions are demonstrated to be free of chemical species containing a number of carbon atoms ranging from 7 to 40. However, Δd (accounting for PPF restructuring) might come with the dissolution of PPF materials having less than 7 carbon atoms.     

Phase separation in poly(butylene terephthalate)-based materials prepared by solid-state modification

The morphology of a series of poly(butylene terephthalate) (PBT)/fatty acid dimer diol (FADD)-based copolyesters prepared by solid-state modification (SSM) was studied. It was shown that in copolyesters containing less than 10 wt% FADD two different phases, i.e. a PBT crystalline phase and a PBT-rich amorphous phase, are present. The FADD residues were more or less homogeneously distributed throughout the interlamellar regions. For copolymers containing more than 10 wt% of FADD, a three-phase morphological model has to be used due to phase separation of a FADD-rich amorphous phase from the PBT-rich matrix, as confirmed by solid-state nuclear magnetic resonance spectroscopy and transmission electron microscopy. The final morphology was dependent on the morphology of the PBT/FADD-based physical mixtures prior to SSM. In addition, it was shown that FADD diffusion during SSM influences the final morphology.     

Rheological properties of bimodal polyethylenes produced with silica nanoparticle supported catalysts

The rheological properties of bimodal ultra-high-molecular-weight polyethylenes (UHMWPEs) are investigated with an emphasis on the influence of the catalyst support. Bimodal UHMWPEs were produced in a single reactor with double support (DS) and single support (SS) catalyst systems. Dynamic measurements showed that the SS samples have a higher storage modulus at low frequencies than the DS samples with the same weight average molecular weight. After extrusion, the storage modulus of the bimodal DS samples increased to an identical value. The results indicate that the SS sample has a higher homogeneity than the DS sample. The steady-shear viscosities were measured to determine zero shear viscosities (η₀) of the bimodal samples. The results show that the SS samples follow the relation η₀ = KM_w^α with α = 3.19 . However, the DS samples exhibit a substantial deviation from this relation especially in the intermediate M_w range around 1000 kg mol⁻¹. The reason for the deviation is attributed to the heterogeneity in DS samples. The results demonstrate that the DS systems do not produce bimodal PEs with an intimate degree of mixing of short and long polymer chains even if silica nanoparticles are used as the support. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47577.     

Effects of Trypanosoma congolense infection and diet on puberty, age at first lambing and haematology changes in Djallonké ewe lambs

The interactions between T. congolense infection and nutritional supplements on onset of puberty and age at first lambing were observed in 24 young Djallonké ewes. As experimental design, a randomised complete block design was used with four treatment combinations, of which two were kept on a restricted diet (L), the remainder on an unrestricted diet (H) and half of each nutritional group being infected with T. congolense (LI and HI), the remainder serving as controls (LC and HC). Infection with T. congolense took place at an average age of 6 months and 15 days. Mortality due to trypanosome infection was zero and clinical symptoms were not obvious. Intensity of parasitaemia and packed cell volume (PCV) drop following trypanosome infection were similar in both infected groups (HI and LI). High dietary supplementation resulted temporarily in a better haematopoietic response following trypanosome infection, measured as a macrocytic anaemia. Dry matter intake (DMI) was significantly depressed in the HI group immediately following infection. Trypanosome infection had a negative effect on live weight gain during the chronic phase, with the difference being most obvious in the HI group (interaction diet x infection; p< or =0.05). Whereas trypanosome infection had no significant effect, high supplementary feeding significantly reduced the age at first cycling. Age at first lambing was similarly reduced by the diet. Trypanosome infection tended (p< or =0.09) to delay age at first lambing with a mean difference of 31.5+/-22.4 days between infected and controls. Interactions between diet and infection for age at first cycling/lambing were not significant, indicating these effects were just additive. Neither birth weights nor growth rates of offspring born to the experimental animals were significantly affected by previous trypanosome infection, nor by the diet of the dam. In contrast, lamb mortality up to 3 months of age was significantly increased by infection of the dam and most losses arose in group LI. In conclusion, the effects of trypanosome infection on puberty and age at first lambing were indirectly mediated through depression of growth rates. Nutritional supplementation enabled a better erythropoietic response to T. congolense infection and better offspring survival rates but resulted in more depressed weight gains. The results however clearly indicated the delaying effect of insufficient feeding on onset of puberty and reproductive performance in young Djallonké sheep.     

Schedulability and sensitivity analysis of multiple criticality tasks with fixed-priorities

Safety-critical real-time standards define several criticality levels for the tasks. In this paper we consider the real-time systems designed under the DO-178B safety assessment process (i.e., Software Considerations in Airborne Systems and Equipment Certification). Vestal introduced a new multiple criticality task model to efficiently take into account criticality levels in the schedulability analysis of such systems. Such a task model represents a potentially very significant advance in the modeling of safety-critical real-time softwares. Baruah and Vestal continue this investigation, with a new scheduling algorithm combining fixed and dynamic priority policies. Another major design issue is to allow a system developer to determine how sensitive is the schedulability analysis to changes in execution time of various software components.     

The temporal dimension of differenced Normalized Burn Ratio (dNBR) fire/burn severity studies: The case of the large 2007 Peloponnese wildfires in Greece

The temporal dimension of differenced Normalized Burn Ratio (dNBR) fire/burn severity studies was studied for the case of the large 2007 Peloponnese wildfires in Greece. Fire severity is defined as the degree of environmental change as measured immediately post-fire, whereas burn severity combines the direct fire impact and ecosystems responses. Geo Composite Burn Index (GeoCBI), two pre-/post-fire differenced Thematic Mapper (TM) dNBR assessments and a Moderate Resolution Imaging Spectroradiometer (MODIS) dNBR time series were used to analyze the temporal dimension. MODIS dNBR time series were calculated based on the difference between the NBR of the burned and control pixels, which were retrieved using time series similarity of a pre-fire year. The analysis incorporated the optimality statistic, which evaluates index performance based on displacements in the mid-infrared-near infrared bi-spectral space. Results showed a higher correlation between field and TM data early post-fire (R² = 0.72) than one-year post-fire (R² = 0.56). Additionally, mean dNBR (0.56 vs. 0.29), the dNBR standard deviation (0.29 vs. 0.19) and mean optimality (0.65 vs. 0.47) were clearly higher for the initial assessment than for the extended assessment. This is due to regenerative processes that obscured first-order fire effects impacting the suitability of the dNBR to assess burn severity in this case study. This demonstrates the importance of the lag timing, i.e. time since fire, of an assessment, especially in a quickly recovering Mediterranean ecosystem. The MODIS time series was used to study intra-annual changes in index performance. The seasonal timing of an assessment highly impacts what is actually measured. This seasonality affected both the greenness of herbaceous resprouters and the productivity of the control pixels, which is land cover specific. Appropriate seasonal timing of an assessment is therefore of paramount importance to anticipate false trends (e.g. caused by senescence). Although these findings are case study specific, it can be expected that similar temporal constraints affect assessments in other ecoregions. Therefore, within the limitations of available Landsat imagery, caution is recommended for the temporal dimension when assessing post-fire effects. This is crucial, especially for studies that aim to evaluate trends in fire/burn severity across space and time. Also, clarification in associated terminology is suggested.     

A hardware/software platform for QoS bridging over multi-chip NoC-based systems

Recent embedded systems integrate a growing number of intellectual property cores into increasingly large designs. Implementation, prototyping, and verification of such large systems has become very challenging. One of the reasons is that chips/FPGAs resources are limited and therefore it is not always possible to implement the whole design in the traditional system-on-a-chip solutions. The state-of-the-art is to partition such systems into smaller sub-systems to implement each on a separate chip. Consequently, it requires interconnecting separate chips/FPGAs. Since Networks-on-Chip (NoCs) have become common interconnection solutions in embedded designs, we propose to bridge NoC-based SoCs enabling a generic multi-chip systems interconnection. In this context, the contribution of this paper is threefold, (i) we explore the NoC protocol stack to determine the best layer for implementing the off-chip bridge, (ii) we propose a generic hardware architecture for the bridge, and (iii) we develop a new software architecture enabling seamless configuration and communication of multi-chip NoC-based SoCs. Finally, we demonstrate performance, i.e., bandwidth and latency, of the bridge in a multi-FPGA platform, while the bridge guarantees QoS of traffic. The synthesis results indicate the implementation area cost of the bridge is only 1% of Xilinx Virtex6 FPGA.     

The use of multi‐temporal Landsat images for the change detection of the coastal zone near Hurghada,Egypt

A Landsat 5 Thematic Mapper (TM) image of 1987 and a Landsat 7 Enhanced Thematic Mapper Plus (ETM+) image of 2000 were used to examine changes in land use/land cover (LULC) around Hurghada, Egypt, and changes in the composition of coral reefs offshore. Prior to coral reef bottom‐type classification, the radiance values were transformed to depth‐invariant bottom indices to reduce the effect of the water column. Subsequently, a multi‐component change detection procedure was applied to these indices to define changes. Preliminary results showed significant changes in LULC during the period 1987–2000 as well as changes in coral reef composition. Direct impacts along the coastline were clearly shown, but it was more difficult to link offshore changes in coral reef composition to indirect impacts of the changing LULC. Further research is needed to explore the effects of the different image‐processing steps, and to discover possible links between indirect impacts of LULC changes and changes in the coral reef composition.     

The Intergenerational Transmission of Perfectionism: Parents' Psychological Control as an Intervening Variable.

The present study investigated the role of parental (adaptive and maladaptive) intrapersonal perfectionism as a predictor of parental psychological control and the role of parents' psychological control in the intergenerational transmission of perfectionism in a sample of female late adolescents and their parents. First, parental maladaptive perfectionism, but not parental adaptive perfectionism, significantly predicted parents' psychological control even when controlling for parents' neuroticism. This relationship was found to be stronger for fathers than for mothers. Second, a significant direct relationship was found between mothers' and daughters' maladaptive perfectionism but not between fathers' and daughters' maladaptive perfectionism. Third, process analyses showed that, for both mothers and fathers, psychological control is an intervening variable in the relationship between parents' and daughters' maladaptive perfectionism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Presence of Starch/Protein Aggregates in the Endosperm of Corn

It is common knowledge that the presence of so called “grits” and other structures in process streams of the corn wet milling process leads to starch yield losses by incomplete starch/gluten separation. The nature of these problematic structures was investigated by isolating them from the process streams and analysing their morphology by means of epifluorescence microscopy using specific dyes. Additional evidence was obtained by specific enzymatic degradation and subsequent microscopic observation. Using the same technique on thin cross sections from whole corn kernels, the location and source of these structures could be identified. Grits are dense particles from the horny endosperm, consisting of a three dimensional honeycomb like protein matrix filled with small starch granules. Many grits show the regular cell shape found in endosperm cells and are still enclosed by the fibrous cell wall. In other process streams, aggregates of protein lumps with trapped large and small starch granules occur frequently. A small fraction of fibrous material was also found to be enclosed in the protein matrix. These “sticky” aggregates often occur along with a large percentage of extremely small starch granules or fragments. Occasionally, very small “grits”-like particles were present. Based on these findings, explanations can be found for the loss of starch and for the difficulties in the starch-gluten separation stage in the industrial corn wet milling process.