Addressing Learner Satisfaction Outcomes in Electronic Instrumentation and Measurement Laboratory Course Organization

This paper proposes and details a course organization methodology based on learner satisfaction achievement. The approach follows the prevailing tendency in modern university reforms which are primarily concerned about "how people learn." As a consequence, the learner has been placed as the main actor of the teaching-learning process. Nevertheless, the current learning literature has not addressed the measurement of learner satisfaction within laboratory and practical subjects. This study develops a general and comprehensive methodology for learner satisfaction measurement in practical subjects. As a case example, the proposed methodology has been applied to an electronic instrumentation and measurement course, confirming the variables with a significant influence on learner satisfaction and becoming the starting point for curriculum redesign based on the learner satisfaction approach. To assess the improvement of the proposed course organization methodology, a comparison with previous academic years has been performed showing the students' rated score evolution. Results fully confirm the validity of the technique and the novel course organization     

Kraft mill sludge to improve vegetal production in Chilean Andisol.

The effect of kraft mill sludge addition (25 to 75 ton/ha) to soil derived from volcanic ashes (Andisol) on wheat (Triticum aestivum L.cv. Puken) biomass production, and in the nutrient absorption by the plants was evaluated. Respiration activity and seed germination tests were carried out on the soil/sludge mixtures, in order to evaluate possible toxic effects due to the sludge addition to the soil. Soil without sludge was used as a control treatment. The plants were grown in a greenhouse (25 degrees C, 14 h-photoperiod) during 120 days, then the plants were collected and dried at 65 degrees C for 72 h for the determination of biomass production (root and aerial) and analyzed for mineral content (Ca, Mg, K and P). The mixtures of soil/sludge showed no toxicity. Seed germination and respiration activity increased with the increment of the sludge. The accumulated CO2 in the soil without sludge was 41.66 mg CO2/100; this value shows a low microbial activity. The biomass increased with the increment of sludge addition to the soil and five times more biomass was obtained when 75 ton/ha sludge was added to the soil. The nutrient absorption efficiency was also improved with the sludge addition.     

Comparative analysis of the electroactive area of Pt/C PEMFC electrodes in liquid and solid polymer contact by underpotential hydrogen adsorption/desorption

Because of the different experimental conditions found in literature for the measurement of the electroactive area of Pt/C electrodes of proton exchange membrane fuel cells (PEMFC) by means of underpotential hydrogen adsorption (H_UPD) voltammetry, specially concerning sweep rate and temperature, it was found necessary to perform an analysis of these parameters. With this aim, the electroactive area of PEMFC electrodes has been measured by means of H_UPD voltammetry at different sweep rates and temperatures, in liquid electrolyte and solid polymer contact. Both configurations show that H_UPD adsorption and desorption charges are strongly dependent on sweep rate voltage and temperature. The most common behaviour observed is a maximum in H_UPD desorption charge, typically in the 100–10 mV s⁻¹ sweep rate range, whereas H_UPD adsorption charge shows continuous increase with decreasing sweep rate. The decrease of desorption charge at low sweep rates is attributed to adsorbing species related with carbon support reactivity. These processes are also responsible for the increase in desorption H_UPD charge at low sweep rate. At high sweep rate, both adsorption and desorption H_UPD charges decrease due to limiting diffusion of protons through the microporous electrode. As a consequence, it is found that the closest approximation to the real electroactive area (i.e. the area accessible to protons) corresponds to the maximum in the H_UPD desorption charge in the range of 10–100 mV s⁻¹ sweep rate. The influence of measuring temperature is also tested in the range 25 °C–80 °C. A dependence of the adsorption and desorption hydrogen charges is found, due to thermodynamic and kinetics factors. We observe that the processes competing with hydrogen adsorption, i.e. generation and adsorption of carbon species are enhanced with temperature, so a low measuring temperature is found as most appropriate.     

Nutritional composition and safety of Patagonotothenramsayi, a discard species from Patagonian Shelf

Patagonotothen ramsayi, a nototheniid discard species from the southwest Atlantic, was studied to evaluate its composition, quality and suitability for human consumption. The chemical composition of the flesh revealed that P. ramsayi is a valuable food with protein and fat contents ranging between 16–19% and 0.78–1.34%, respectively. It has a high amount of unsaturated fatty acids, especially docosahexaenoic acid (30–42%) and eicosapentaenoic acid (12–18%). It is also a potential source of minerals, with important amounts of magnesium, potassium and phosphorous. The microbial quality of P. ramsayi was good and the detection of toxic metals such as Pb, Cd and Hg revealed that there is no intrinsic risk associated with its consumption. Additionally, no parasites with potential public health implications were found in the flesh. Finally, its flesh is white, with a shellfish odour, and has a firm and elastic texture. The present study shows that P. ramsayi is a nutritious species of high value for human consumption.     

Structural Diversity of PDZ–Lipid Interactions

PDZ domains are globular protein modules that are over‐and‐above appreciated for their interaction with short peptide motifs found in the cytosolic tail of membrane receptors, channels, and adhesion molecules. These domains predominate in scaffold molecules that control the assembly and the location of large signaling complexes. Studies have now emerged showing that PDZ domains can also interact with membrane lipids, and in particular with phosphoinositides. Phosphoinositides control various aspects of cell signaling, vesicular trafficking, and cytoskeleton remodeling. When investigated, lipid binding appears to be extremely relevant for PDZ protein functionality. Studies point to more than one mechanism for PDZ domains to associate with lipids. Few studies have been focused on the structural basis of PDZ–phosphoinositide interactions, and the biological consequences of such interactions. Using the current knowledge on syntenin‐1, syntenin‐2, PTP‐Bas, PAR‐3 and PICK1, we recapitulate our understanding of the structural and biochemical aspects of PDZ–lipid interactions and the consequences for peptide interactions.     

Covalent surface functionalization of carbon nanostructures via [2 + 1] cycloaddition microwave-assisted reactions

Journal of Materials Science - The use of [2?+?1] cycloaddition microwave-assisted reaction as an effective and versatile method for the surface covalent functionalization of...     

Dynamic resource management considering the real behavior ofaggregate traffic

This paper explains why the theory of effective bandwidth is in general not applicable to characterize realistic traffic sources. Moreover, we show that a static allocation of network resources (bandwidth and/or buffer space) based on large deviation theory can be highly inefficient when the real statistical behavior of traffic is taken into account. As an alternative, we propose a dynamic resource management scheme based on prediction techniques. As a specific example, we apply this scheme to a Differentiated Service (DiffServ) Internet environment, in which the goal, besides policing the incoming traffic, is to optimize the use of network resources, thus minimizing the probability of occurrence of violations of contract guarantees. The performance of the proposed scheme is evaluated via simulations and our results show the superior performance of the new algorithm in terms of buffer overflows, output link utilization, and jitter, as compared to currently used policing and shaping mechanisms