We aimed to evaluate the novel chaotic global techniques of heart rate variability (HRV) analysis during a specific autonomic test, the mental arithmetic overload test. These are spectral detrended fluctuation analysis and spectral multi-taper method; in addition to spectral entropy. We analyzed 24 healthy male students-all nonsmokers, aged between 18 and 22 years old. HRV was analyzed in the following periods: control protocol-the 10-min periods before the performance of the task and the 5-min periods during the performance of the test. Following tests for normality; Kruskal-Wallis technique and principal component analysis-it was decided that this type of mental stimulation did not lead to significant changes in any of the seven combinations of chaotic globals. In conclusion, it was suggested that the time-series be increased to 1000 RR intervals (at least 20 min of electrocardiographic data) and standard nonlinear methods be introduced in combination with spectral factors as a way of increasing the statistical significance.

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The objective of this work was to evaluate the effect of the addition of bamboo laminas of the species Dendrocalamus giganteus to three-layer medium density particleboard (MDP). These laminas were glued onto both the top and the bottom of each panel. With the manufactured panels laminated with bamboo, mechanical tests based on the Brazilian Standard ABNT NBR 14810 were carried out to determine the modulus of rupture (MOR) in static bending and the tensile strength parallel-to-surface. These mechanical tests were realized in particleboards of eucalyptus and in reinforced particleboard, both produced in the laboratory. The modulus of rupture and tensile strength parallel-to-surface of the laminated MDP had values close to those that have been reported. The reinforcements increased the values of these studied properties. Nevertheless, this fact indicated the possibility to produce a stronger MDP using bamboo lamina as surface layers. These results show the possibility of using coatedbamboo MDP for utilization in large spans, for example, in flooring for mezzanines with finish on both sides, and for robust furniture as bookshelves, beds, tables, etc.

RESUMO:O objetivo deste trabalho consistiu no aproveitamento de resíduos de madeira tropical de baixa densidade (Cordia goeldiana) para confecção de chapas de partículas com resinas poliuretanas monocomponente e bicomponente derivadas de óleo de mamona, gerando subsídios como aplicação nas construções rurais e civis, assim como na indústria moveleira. As propriedades físicas e mecânicas investigadas foram: densidade; teor de umidade; módulo de resistência na flexão estática e adesão interna, ambas obtidas segundo os procedimentos de cálculo propostos pela norma Brasileira NBR 14810:2002. As chapas foram confeccionadas com 15% de resina (uma parte de poliol para uma parte de pré-polímero), 4MPa de pressão de compactação, temperatura de prensagem de 90o C e tempo de prensagem de 7 minutos. Os valores médios obtidos das propriedades físicas e mecânicas das chapas foram sistematicamente superiores aos requisitos da norma Brasileira, evidenciando a possibilidade do emprego dos resíduos da madeira de Cordia goeldiana na produção de painéis de partículas. Confirmou-se também a hipótese da significativa relação linear entre a densidade das chapas com a adesão interna, o que possibilita a estimativa da adesão interna para painéis de partículas de madeira. PALAVRAS-CHAVE: painéis de partículas, resina poliuretana, resíduos de madeiras tropicais. PARTICLEBOARDS MANUFACTURED WITH Cordia goeldiana WOOD WASTESABSTRACT: The aim of this research consisted in the use of wastes from tropical wood (Cordia goeldiana) with low density and the polyurethane resin (mono and bicomponent) castor oil based in the manufacture of particleboards, generating subsidies as application in rural and civil construction, as well in the furniture industry. The particleboards were manufactured with 15% of polyurethane resin content (one part of pre-polymer and one part of polyol), compaction pressure of 4MPa, pressing temperature of 90°C and press time of 7 minutes. The physical and mechanical properties investigated were density, moisture content, strength modulus in bending and internal bond, both obtained according to the recommendations of the Brazilian standard ABNT NBR 14810:2002. The mean values obtained for these properties were systematically superior to the Brazilian standard requirement. This point showed that it is possible the use of Cordia goeldiana wastes in the particleboard production. We confirmed the hypothesis of a significant linear relation between density and the internal bond of the panels, allowing the estimation of the internal bond of particleboards.

This work aimed to study the feasibility of using castor oil-based polyurethane (PU) resin, and rubberwood for the production of particleboards. Multilayer panels were produced using particles taken from RRIM 600 and GT1 clones of Hevea brasiliensis trees. Urea-formaldehyde (UF) and PU were used for bonding the particles. Physico-mechanical characterization was done according to the specifications of the European standards for wood-based panels. The average results were compared to values pre-established by the EN 312/2003 technical standard as well as between the above mentioned treatments. The results indicated that the use of PU and rubberwood has a great potential for particleboards production. The use of PU favors the production of boards with improved physical-mechanical characteristics.

Background The literature is ambiguous as to whether exposure to relaxing classical music before mental arithmetic overload tests can affect cardiac autonomic regulation. Objectives To evaluate the effects of musical auditory stimulation on cardiac autonomic regulation after a mental arithmetic test. Methods This prospective study was conducted with 28 healthy male students aged 18–25 years. In the first evaluation protocol, participants rested for 10 min with the earphone turned off. After this period, participants had 5 min to perform the mental arithmetic overload test and 5 min of rest post test. In the second protocol, the participant was exposed to musical auditory stimuli for 10 min before completing the mental arithmetic overload test. Geometric indices [triangular interpolation of RR intervals (TINN); triangular index of RR intervals (RRtri); and Poincaré plot ratios SD1, SD2 and SD1/SD2] of heart‐rate variability (HRV) were evaluated before, during and after the mental arithmetic test. The Shapiro–Wilk test was used to verify data normality. For parametric variables, repeated measures ANOVA was used followed by the Bonferroni test. For non‐parametric distributions, Friedman's test was used followed by the Dunn's post‐test. Results The mental task did not change HRV under control conditions. Following exposure to musical stimuli, there was significant (P<0.05) cardiac autonomic changes, derived from RRtri, TINN and SD2 indices, which decreased during and after the mental arithmetic test. Conclusions We evaluated the acute effects of classic baroque musical auditory stimulation on cardiac autonomic regulation after a mental task in 28 male volunteers. The findings suggest auditory stimulation increases cardiac autonomic sensitivity induced by mental tasks.

Abstract. The study aimed to analyze the longitudinal modulus of elasticity (Em), based on static bending tests, in different spans and confirm that it’s necessary adopt as 21 the ratio between span and height of the cross section of the specimen to turn no significant the influence of shear stress on vertical deflection. So, simplified equation to determine Emcan be employed. Specimens ofPinus elliottiivar.elliottiiandPinus elliottiivar. elliottii×Pinus cariabeaehondurensis(hybrid), came from Itapeva region, São Paulo State, Brazil, were considered. Bending tests were conducted in Labs of Experimental Campus Itapeva, UNESP, adapting recommendations of Brazilian Code ABNT NBR 7190. Twelve specimens of each species were tested. The trend lines for the plotted graphics showed clearly a nonlinear behavior until the neighborhood of ratio 21 and no expressive variations after this point, confirming that normative recommendations are correct.

Context: Software testing is an important task in software product quality assurance. Alternatives approach for teaching and training students and professionals have been addressed in many studies, recently. In this article, peer testing is investigated as one alternative approach to mitigate the current lack of well-trained professionals. Objective: To verify the efficiency and efficacy of peer testing in order to create test cases to promote software testing education and training. Method: Conduct a controlled experiment in which subjects design and implement test cases for three small software units. Results and conclusions: In this study, it has been observed that peer testing was significantly more efficient than individual testing (with t-Test). On the other hand, it has not been observed significant differences in the efficacy of peer testing.