Physics students’ performance using computational modelling activities to improve kinematics graphs interpretation

The purpose of this study was to investigate undergraduate students’ performance while exposed to complementary computational modelling activities to improve physics learning, using the softwares Modellus. Interpretation of kinematics graphs was the physics topic chosen for investigation. The theoretical framework adopted was based on Halloun’s schematic modelling approach and on Ausubel’s meaningful learning theory. The results of this work show that there was a statistically significant improvement in the experimental group students’ performance when compared to the control group, submitted just to a conventional teaching method. Students’ perception with respect to the concepts and mathematical relations, as well as the motivation to learn, originated by the activities, have played a fundamental role in these findings.     

Green attributes converged within multifunctional technology products

This article analyzes the way in which the convergence of green attributes in multifunctional technological products influences consumers’ purchase intentions. Due to the recent growth in convergent products, technology users and consumers must choose among numerous different applications that can be perceived as either utilitarian or hedonic. This article suggests that new products launched on the market include attributes that are connected to sustainability and provide added value to consumers in their process of decision making. The primary question addressed in this article concerns whether an increase or decrease in consumer intention is based on the perception of the product’s utility, and the consumer’s prior experience and attitude toward green products. A 2 × 2 × 2 experiment was conducted to evaluate utilitarian or hedonic convergence, green attribute integration, and predisposition for (involvement with) green products. We propose that consumer value increases for those consumers with a high perception of green integration connected to a high predisposition for green devices, which increases the utilitarian value of the product or justifies the hedonic purchase of technological equipment.     

Ferulic Acid and Naturally Occurring Compounds Bearing a Feruloyl Moiety: A Review on Their Structures,Occurrence, and Potential Health Benefits

The ubiquitous compound 4‐hydroxy‐3‐methoxycinnamic acid, also known as ferulic acid (FA), constitutes a bioactive ingredient of many foods that may offer beneficial effects against disorders related to oxidative stress, including cancer, diabetes, and neurodegenerative diseases. This review discusses the antioxidant properties of FA, establishing relationships to several biological activities already described for this natural product. Next, 387 naturally occurring compounds, all isolated from plants and published between 1990 and 2015, the structures of which bear 1 or more feruloyl moieties, are covered in this review along with their structural formulas, botanical sources, and bioactivities. The compounds’ distribution, structural patterns, bioactivities, and perspectives on food research are also succinctly discussed.     

Using mathematical methods for designing optimal mixtures for building bricks prepared by solid industrial waste

This study evaluates the use of solid industrial waste generated by a water treatment plant (WTP) at a pulp mill in Brazil for manufacturing building bricks. The sludge from the WTP was mixed with three different wastes generated by the same factory (dregs, grits, and lime mud) and other wastes generated from crushing and grinding granite rock (granite fines). Mathematical and statistical methods are proposed for designing mixtures that satisfy the material properties for ceramic processing and the mechanical properties for the end product. A method for solving a linear system of equations using fewer equations than variables was required, as the number of materials exceeded the number of reference grain size distributions. This type of system is generally compatible and indeterminate. To obtain feasible solutions, a combination-of-variables method is proposed to optimize the mixture design. The formulation of the mixtures was based on the grain size distribution of the residues and the proportions of calcium, sodium, and potassium oxides in the mixtures. The nonparametric Kruskal–Wallis test and the median test were applied for all mixtures, followed by a multiple comparison test of classes. The mechanical properties of the specimens were evaluated after drying (linear shrinkage and flexural strength) and firing (ignition loss, linear shrinkage, and flexural strength) according to the Brazilian Association of Technical Standards and Brazilian Standards for red ceramics.     

Optimization of Trehalose Production by <Emphasis Type="Italic">Rhodotorula dairenensis</Emphasis> Following a Sequential Strategy of Experimental Design

Initially, a technical screening was applied to select yeasts with a potential for trehalose production using thermal stress for the induction of synthesis. The effects of the concentrations of sugar cane molasses, corn steep liquor and a commercial yeast extract Prodex Lac SD®, and of pH and temperature on the biomass were studied using a fractional design followed by a central composite rotatable design (CCRD). The optimum values were 50 g/l for the molasses and corn steep liquor concentrations, initial pH of 5.5, and temperature of 30 °C, with no yeast extract. Under these conditions, the production of trehalose was studied using a CCRD to optimize the temperature (33 to 47 °C) and exposition time (60 to 120 min) of the cultures to the thermal stress. The maximum intracellular trehalose content reached was 20.5% (g trehalose/100 g dry cell) at temperatures of 35–40 °C and with 100–120 min of exposition time to the thermal stress.