Complex modal analysis of a vertical rotor through finite element method

Natural frequencies were analyzed (axial, torsional and flexural) and frequency response of a vertical rotor with a hard disk at the edge through the classical and complex modal analysis. The mathematical modeling was based on the theory of Euler-Bernoulli beam. The equation that rules the movement was obtained through the Lagrangian formulation. The model considered the effects of bending, torsion and axial deformation of the shaft, besides the gravitational and gyroscopic effects. The finite element method was used to discretize the structure into hollow cylindrical elements with 12 degrees of freedom. Mass, stiffness and gyroscopic matrices were explained consistently. This type of tool, based on the use of complex coordinates to describe the dynamic behavior of rotating shaft, allows the decomposition of the system in two submodes, backward and forward. Thus, it is possible to clearly visualize that the orbit and direction of the precessional motion around the line of the rotating shaft is not deformed. A finite element program was developed using Matlab ®, and numerical simulations were performed to validate this model.

Exploratory study of electromyographic behavior of the vastus medialis and vastus lateralis at neuromuscular fatigue onset

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Diagnostic accuracy of the EMG parameters associated with anterior knee pain in the diagnosis of patellofemoral pain syndrome

Objective To assess the diagnostic accuracy of the surface electromyography (sEMG) parameters associated with referred anterior knee pain in diagnosing patellofemoral pain syndrome (PFPS). Design Sensitivity and specificity analysis. Setting Physical rehabilitation center and laboratory of biomechanics and motor control. Participants Pain-free subjects (n=29) and participants with PFPS (n=22) selected by convenience. Interventions Not applicable. Main Outcome Measure The diagnostic accuracy was calculated for sEMG parameters’ reliability, precision, and ability to differentiate participants with and without PFPS. The selected sEMG parameter associated with anterior knee pain was considered as an index test and was compared with the reference standard for the diagnosis of PFPS. Intraclass correlation coefficient, SEM, independent t tests, sensitivity, specificity, negative and positive likelihood ratios, and negative and positive predictive values were used for the statistical analysis. Results The medium-frequency band (B2) parameter was reliable (intraclass correlation coefficient=.80–.90), precise (SEM=2.71–3.87 normalized unit), and able to differentiate participants with and without PFPS (P<.05). The association of B2 with anterior knee pain showed positive diagnostic accuracy values (specificity, .87; sensitivity, .70; negative likelihood ratio, .33; positive likelihood ratio, 5.63; negative predictive value, .72; and positive predictive value, .86). Conclusions The results provide evidence to support the use of EMG signals (B2 – frequency band of 45–96Hz) of the vastus lateralis and vastus medialis muscles with referred anterior knee pain in the diagnosis of PFPS.

Degradabilidade do amido de grãos secos e ensilados de híbridos de milho com textura dura e dentada em função do grau de moagem

This research evaluated corn grains with flint and dent texture (ensiled high-moisture or dried), submitted to grinding degrees, using the in situ ruminal degradation technique. Three rumen canulated adult sheeps were used in a complete randomized design, using a factorial outline 2 x 2 x 3, with two corn hybrids (flint and dent texture), two conservation methods (ensiled high-moisture and dry) and three grinding degress (whole, coarsely and finely ground, corresponding to the sieve of 12; 10 and 8 mm). Starch soluble fraction (A) of the dent hybrid ensiled corn grains was greater comparing to the dry materials and in both conservation forms this fraction was reduced in the flint texture hybrid, while the insoluble fraction potentially degradable (B) the opposite occurred. The degradation potential was higher in grains ensiled in two textures. The ensiled allowed more starch effective degradation in relation to dry grain in two textures and the grains dent texture hybrid also increased such degradation in both conservation methods. The dent texture and the ensiled high-moisture grains proved the best option considering the starch degradability. Regardless of the conservation forms, the grains of corn hybrid flint texture should be finely ground, for providing higher ruminal degradation, while for the dent texture hybrid, the coarsely and whole grinding are the most suitable for ensiled and dry grain, respectively.

Degradabilidade da matéria seca e da proteína bruta de grãos secos e de silagens de grãos úmidos de híbridos de milho (Zea mays), submetidos a diferentes processamentos

The objective of this work was to evaluate the effect of processing two corn hybrids conserved, dry and humid grains, the dry matter (DM) and crude protein (CP) degradability in situ. The particle size was determined and difference was verified in MGD (Medium Geometric Diameter) of processed ingredients. Three sheep were used with rumen canulated, in a completely randomized design, using a factorial outline 2 x 2 x 3, being two corn hybrid, two conservation methods and three processing forms (whole, coarsely and finely ground), with five times of incubation (3, 6, 12, 24 and 48 hours). The fraction A in SDC (silage of dent corn) of DM was superior to GDC (grain of dent corn) in all of the particles size. The ensiling process increased the DM solubility, reducing the fraction B in comparison to dry grain. The values regarding the fractions DP and DE the 5% per hour of the protein, were larger for SDC and GDC, it presents a decreasing when the incubation time advances. The fermentation rate was superior for SDC and GDC. The ensiling process has positive effect in the decreasing of DM and CP in comparison to GDC.

Sobrevivência de enxertos de Eucalyptus com metodologia adaptada

One of the important techniques to assist a tree improvement program is the grafting, which is used for the propagation of selected trees. The objective of this study was to evaluate the survival rate using a modified method of lateral grafting on Eucalyptus dunnii, Eucalyptus urophylla and a hybrid of Eucalyptus urophylla x Eucalyptus grandis. The work was conducted by the research teams of Eucatex and Palmasola companies, in September of 2011, and 589 grafts were made. The survival rate of the grafts was evaluated 180 days after grafting. Survival grafts rates were: 74% for E. dunnii, 55% for E. urophylla and 62% for the hybrid E. urophylla x E. grandis. These survival rates were higher than those currently obtained by the conventional method of eucalypt grafting. Thus, the method seems promising to assist in forest tree improvement programs, but further studies are still necessary to refine this grafting approach.

Polinização controlada em eucaliptos nas empresas florestais brasileiras

Controlled pollination is an important tool in a forest genetic improvement program, which permits to choose parents and make specific crosses maximizing gains and providing superior genotypes in less time than conventional pollination. To verify the needs of the forest companies regarding the conduction of controlled pollination orchards in the breeding program, a specific questionnaire was sent in September 2011 to companies associated to IPEF. The objective of the questionnaire was to collect basic information about the current situation of controlled pollination orchards and check the main difficulties and demands related. It was found that use of the controlled pollination orchard has begun to be used by companies in the Brazilian forest sector just a few years ago and is considered to be very important in breeding programs in order to shorten the time to obtain new genotypes; but there is still need of crucial information regarding the management of these orchards. The main demands are: Basic concepts of flowering induction; homogeneity of flowering; hormonal induction and alternative techniques for flowering; relationship between management and genotypes used; variations in the flowering of different genotypes; management of the orchard in the different phenological phases; process of grafting typesand interaction between graft and rootstock, irrigation systems; species identification and flowering map.

Variabilidade genética e alterações morfológicas em progênies de polinização aberta de Eucalyptus grandis sob o efeito do paclobutrazol

The research objective was to study the genetic diversity of morphological traits in Eucalyptus grandis progenies growing under paclobutrazol regulator effects. The progeny trail was set up through design of randomized blocks. The morphological changes occurred before and during the plant flowering were analyzed. The estimation of genetic parameters were for plant height and stem diameter. The paclobutrazol have caused changes on plant development being strong by the beginning and becoming lightening through the evaluations. The coefficients of variation have shown there is higher genetic diversity within than among progenies for the studied traits. Therefore, it can have high efficiency on selection within progenies in the Eucalyptus grandis breeding program.

Teste de condutividade elétrica para avaliação da qualidade fisiológica de sementes de gergelim (Sesanun indicum L.)

Two experiments were conducted in order to study the effects of seed number, temperature and time of soaking sesame seeds on the results of the electrical conductivity test for physiological quality of seeds. In the experiment I evaluated the electrical conductivity varying the number of seeds (25, 50 and 100) and temperature (20, 25 and 30° C) in experiment II is different soaking periods (2, 4, 6, 8, 12, 16, 20 and 24 h). The tests were performed with three cultivars (cv. Trebol, cv. Cnpa G4 e cv. Comum). The treatments in factorial 3x3x3 and 3x8 in experiments I and II, respectively. The experimental design was completely randomized, with four replications. Means were compared by Tukey test at 5% probability. The characterization of cultivars held through the germination and vigor tests (physical, physiological and biochemical), which rated the Trebol cultivar seeds with better physiological then the Cnpa G4 and Comum. The electrical conductivity test was conducted with four sub-samples of 25 pure seeds soaked in 75 mL of deionized water at 25° C, to separate the lots from 2 hours of soaking, being feasible to evaluate the quality sesame seeds.