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.     

Lipid Droplet Biosynthesis Impairment through DGAT2 Inhibition Sensitizes MCF7 Breast Cancer Cells to Radiation

Breast cancer is the most frequent cancer in women worldwide and late diagnosis often adversely affects the prognosis of the disease. Radiotherapy is commonly used to treat breast cancer, reducing the risk of recurrence after surgery. However, the eradication of radioresistant cancer cells, including cancer stem cells, remains the main challenge of radiotherapy. Recently, lipid droplets (LDs) have been proposed as functional markers of cancer stem cells, also being involved in increased cell tumorigenicity. LD biogenesis is a multistep process requiring various enzymes, including Diacylglycerol acyltransferase 2 (DGAT2). In this context, we evaluated the effect of PF-06424439, a selective DGAT2 inhibitor, on MCF7 breast cancer cells exposed to X-rays. Our results demonstrated that 72 h of PF-06424439 treatment reduced LD content and inhibited cell migration, without affecting cell proliferation. Interestingly, PF-06424439 pre-treatment followed by radiation was able to enhance radiosensitivity of MCF7 cells. In addition, the combined treatment negatively interfered with lipid metabolism-related genes, as well as with EMT gene expression, and modulated the expression of typical markers associated with the CSC-like phenotype. These findings suggest that PF-06424439 pre-treatment coupled to X-ray exposure might potentiate breast cancer cell radiosensitivity and potentially improve the radiotherapy effectiveness.     

The ObReco-360°: a new ecological tool to memory assessment using 360° immersive technology

Virtual Reality - One important feature of a neuropsychological test is its ecological validity, which defines how much patients’ test scores are linked to real-life functioning. However,...     

Catalytic combustion of methane over perovskites

Perovskite-type oxides of the series La_{1− x}A_xMnO₃ (A Sr, Eu and Ce) were prepared by the amorphous citrate process, leading to high surface area catalysts (up to 45 m² g⁻¹). They were tested in a flow reactor for the total combustion of methane. Complete conversion was obtained over all of the catalysts between 500 and 600°C and catalyst performance did not change significantly after 100 h on-stream. Specific activity was found to decrease monotonically with increasing the temperature of the O₂ TPD desorption peak maximum. The rate of methane combustion was low below 500°C, then grew very fast, showing that two kinds of oxygen are active in these catalysts: an adsorbed oxygen species, that reacts at low temperature, and a lattice oxygen species, that becomes available at high temperature, boosting the catalytic activity.     

An Integrated Assessment of the Impacts of Changing Climate Variability on Agricultural Productivity and Profitability in an Irrigated Mediterranean Catchment

Climate change is likely to have a profound effect on many agricultural variables, although the extent of its influence will vary over the course of the annual farm management cycle. Consequently, the effect of different and interconnected physical, technical and economic factors must be modeled in order to estimate the effects of climate change on agricultural productivity. Such modeling commonly makes use of indicators that summarize the among environmental factors that are considered when farmers plan their activities. This study uses net evapotranspiration (ET_N), estimated using EPIC, as a proxy index for the physical factors considered by farmers when managing irrigation. Recent trends suggest that the probability distribution function of ET_N may continue to change in the near future due to changes in the irrigation needs of crops. Also, water availability may continue to vary due to changes in the rainfall regime. The impacts of the uncertainties related to these changes on costs are evaluated using a Discrete Stochastic Programming model representing an irrigable Mediterranean area where limited water is supplied from a reservoir. In this context, adaptation to climate change can be best supported by improvements to the collective irrigation systems, rather than by measures aimed at individual farms such as those contained within the rural development policy.     

The Cost of Irrigation Water Delivery: An Attempt to Reconcile the Concepts of Cost and Efficiency

This work discusses the conflict between two of the main objectives of the EU Water Framework Directive: cost recovery and economic efficiency in the use of irrigation water. In the Mediterranean region, this conflict is commonly embedded in a state of under-utilization of irrigation networks managed by Water User Associations (WUAs). This under-utilization arises from factors independent of farmers’ choice, such as water shortage, crises in the sector, and changes to the Common Agricultural Policy. This prevents the facilities from operating at the minimum average cost. This paper argues that farmers should not suffer this inefficiency, which results in them paying higher water prices to cover the costs of water supply. Indeed, the application of the Water Directive should be rethought, taking into account the specific problems related to irrigation in the Mediterranean region. Based on an econometric analysis of the costs of water distribution in a WUA in Sardinia (Italy), we propose a payment system based on two components. Primarily there is a fee related to the number of hectares under irrigation. In addition there is a fee that considers the intensity of irrigation: this component is to encourage farmers to save water. The results show that the proposed approach has some desirable effects, including higher rates of cost recovery and possibly a reduction in the use of groundwater. Finally, the proposed system is not overly expensive for the rest of the community, who must bear the costs of inefficiencies in the use of irrigation water that do not depend on choices of farmers.     

Modelling sweetness and texture perception in model emulsion systems

Model emulsion samples, prepared subject to a d-optimal response surface design, were used to investigate the effect of rapeseed oil, sugar and hydroxypropyl methyl cellulose thickener (HPMC) on perceived sweetness, textural attributes (thickness, stickiness, mouth-coating, dispersing), instrumental measures of apparent viscosity 50 s⁻¹ and Kokini oral shear stress. An increase in oil, sugar and HPMC resulted in an increase in perceived thickness, stickiness and mouth-coating, and a decrease in dispersion; sweetness was enhanced by the addition of both sugar and oil but suppressed by the addition of HPMC. Viscosity and Kokini oral shear stress were well correlated with oral thickness (r ² > 0.9). Validated multiple linear regression models highlighted several 2-factor interactions between ingredients. Model statistics indicated that the variation in data was well explained; the models were predictive and could be used to navigate the design space. Samples predicted to be iso-thick and iso-sweet could not be discriminated (P > 0.10) in a 3-alternative forced choice (3-AFC) test using 35 panellists.     

On the Approximation of Stochastic Concurrent Constraint Programming by Master Equation

We explore the relation between the stochastic semantic associated to stochastic Concurrent Constrain Programming (sCCP) and its fluid-flow approximation. Writing the master equation for a sCCP model, we can show that the fluid flow equation is a first-order approximation of the true equation for the average. Moreover, we introduce a second-order correction and first-order equations for the variance and the covariance.