Enhancing IP cores specifications using hierarchical composition and set theory

During the functional verification, complex interactions between multiple blocks that compose an Intellectual Property (IP) core can reveal hard-to-find bugs. Functional verification specifications must be precise to assure these interactions occur during the simulation. In this work, we are proposing a technique for improving the functional verification specification of individual blocks, preserving the occurrence of these interaction scenarios in the composition phase. Our approach was implemented for the VeriSC methodology, a SystemC-based functional verification methodology. After each block that composes the IP core was stand-alone verified, we exploit the composition phase using set theory to increase the coverage numbers and to justify why some of these numbers cannot, or need not, reach 100%. By applying our approach in a MPEG 4 video decoder design, we show how our work can save functional verification time during the hierarchical composition. Using mutation based-tests, we demonstrate that our work can contribute to error detection. Furthermore, we demonstrate the effectiveness of our approach with regard to traditional structural coverage metrics, such as line coverage and branch coverage.     

Activated Alpha-2 Macroglobulin Improves Insulin Response via LRP1 in Lipid-Loaded HL-1 Cardiomyocytes

Activated alpha-2 Macroglobulin (α₂M*) is specifically recognized by the cluster I/II of LRP1 (Low-density lipoprotein Receptor-related Protein-1). LRP1 is a scaffold protein for insulin receptor involved in the insulin-induced glucose transporter type 4 (GLUT4) translocation to plasma membrane and glucose uptake in different types of cells. Moreover, the cluster II of LRP1 plays a critical role in the internalization of atherogenic lipoproteins, such as aggregated Low-density Lipoproteins (aggLDL), promoting intracellular cholesteryl ester (CE) accumulation mainly in arterial intima and myocardium. The aggLDL uptake by LRP1 impairs GLUT4 traffic and the insulin response in cardiomyocytes. However, the link between CE accumulation, insulin action, and cardiac dysfunction are largely unknown. Here, we found that α₂M* increased GLUT4 expression on cell surface by Rab4, Rab8A, and Rab10-mediated recycling through PI₃K/Akt and MAPK/ERK signaling activation. Moreover, α₂M* enhanced the insulin response increasing insulin-induced glucose uptake rate in the myocardium under normal conditions. On the other hand, α₂M* blocked the intracellular CE accumulation, improved the insulin response and reduced cardiac damage in HL-1 cardiomyocytes exposed to aggLDL. In conclusion, α₂M* by its agonist action on LRP1, counteracts the deleterious effects of aggLDL in cardiomyocytes, which may have therapeutic implications in cardiovascular diseases associated with hypercholesterolemia.     

Activated carbon for hydrogen purification by pressure swing adsorption: Multicomponent breakthrough curves and PSA performance

In this work, multicomponent breakthrough experiments (binary H₂-CO₂, ternary H₂-CO₂-CO and five-component H₂-CO₂-CO-CH₄-N₂) were performed under different operating conditions in activated carbon extrudates to validate the mathematical model. A 10 steps one-column VPSA experiment was also performed. These experiments allow experimental validation of adsorption equilibrium predicted by the multicomponent extension of the Virial isotherm and a fixed-bed mathematical model. In the VPSA experiment, a 99.981% hydrogen purity stream (with 63 ppm of CO contamination) was obtained with a hydrogen recovery of 81.6% and an adsorbent productivity of .The mathematical model was also employed to assess the effect of operating conditions and the influence of step times and pressure equalizations in the PSA unit. It was verified that high-purity hydrogen (>99.99%) can be obtained using this adsorbent with recoveries higher than 75% and unit productivities of .     

Inhibitory action of aqueous coffee ground extracts on the corrosion of carbon steel in HCl solution

The effects of aqueous extracts of spent coffee grounds on the corrosion of carbon steel in a 1 mol L⁻¹ HCl were examined. Two methods of extraction were studied: decoction and infusion. The inhibition efficiency of C-steel in 1 mol L⁻¹ HCl increased as the extract concentration and temperature increased. The coffee extracts acted as a mixed-type inhibitor with predominant cathodic effectiveness. In this study, the adsorption process of components of spent coffee grounds extracts obeyed the Langmuir adsorption isotherm. The chlorogenic acids isolated do not seem to explain the corrosion inhibition observed during the use of the coffee extracts.     

Physical properties and antioxidant capacity of starch–sodium caseinate films containing lipids

Biodegradable films based on starch, sodium caseinate, glycerol and lipids (oleic acid and/or α-tocopherol) were obtained and evaluated in terms of microstructure, mechanical behaviour, barrier and optical properties and antioxidant capacity. The effect of film storage time on these properties was also analysed. The lipid incorporation provoked phase separation due to the different interaction between each polymer and lipids, although structural rearrangement of components during storage could be deduced from the change in mechanical behaviour. After storage, all films showed similar mechanical properties, but lipid containing films were more stretchable. Lipid addition did not induce a notable decreased in water vapour permeability of the films, but oxygen permeability highly increased when they contained oleic acid. All films were highly transparent, with very small differences among formulations, although their gloss values increased when lipids were added. The incorporation of α-tocopherol greatly increased the antioxidant capacity of the films which affected oxygen permeability.     

The effects of laser energy density and particle size in the selective laser sintering of polycaprolactone/progesterone specimens: morphology and drug release

The goals of this work were to fabricate specimens of different powder particle sizes and laser energy density of polycaprolactone and progesterone by selective laser sintering and evaluate the morphology by scanning electron microscopy and the mechanism of drug release in vitro. The results showed that the specimens maintained morphological uniformity, coalescence of particles, and interconnected pores distributed in the sintered structure. The drug release mechanism of all specimens studied followed a zero-order kinetics, and drug release rates were dependent on sintering degree and, consequently, on matrix erosion.     

The study of ternary carbides formation during SPS consolidation process in the WC–Co–steel system

Tungsten carbide has a wide range of applications, mainly cemented carbides made of WC and Co, as wear resistant materials. However, the high cost of WC–Co powders encourages the use of a substrate to manufacture a functionally graded material (FGM) tool made of WC–Co and a tool steel. These materials join the high wear resistance of the cemented carbide and the toughness of the steel. This work deals with the study interaction of the WC–Co and H13 steel to design a functionally graded material by means of spark plasma sintering (SPS). The SPS, a novel sintering technique reaching the consolidation of the powders at relatively low temperatures and short dwell times, is a promising technique in processing materials. In this study, WC, H13 steel, WC–Co, WC–H13 steel and WC–Co–H13 steel bulk samples were investigated using scanning electron microscopy and X-ray diffraction techniques to evaluate the phase transformations involved during SPS consolidation process. The W₂C and W₃Fe₃C precipitation were identified after the SPS consolidation of the WC and WC–H13 steel samples, respectively. The precipitation of W₄Co₂C was also identified in the WC–Co and WC–Co–H13 steel samples. The WC–H13 steel and WC–Co–H13 steel were also evaluated after heat treatments at 1100 °C for 9 h, which enhanced the chemical interaction and the precipitation of W₃Fe₃C and W₄Co₂C, respectively.     

Multivariate analysis of the water quality variation in the Serra da Estrela (Portugal) Natural Park as a consequence of road deicing with salt

The concentration of some anions (Cl, F, NO₃, and SO₄), cations (Na, K, Ca, and Mg), pH and conductivity was determined in seven sampling points in the Serra da Estrela Mountains (Portugal) to verify if the application of road deicing with salt provokes impact in the water quality. Multivariate chemometric data analysis techniques of clustering and factor analysis were used. Preliminary analysis shows an overall conductivity increase in late spring and a decrease in late summer. A strong association between sodium chloride and the conductivity was observed by cluster analysis. Factor analysis supports the previous results and shows that the variation of the concentration of sodium chloride is the main source of the variance of the data along the year. In conclusion, the spreading of salt during the winter creates a local and seasonal impact on the water quality.