Avaliação dos parâmetros de insensibilização e os impactos na qualidade da carne de perus (Meleagris gallopavo)

Brazil is the third largest producer and exporter of turkey meat, especially in Paraná state, with the largest production volume. In worldwide the animal welfare is a prerequisite for food quality of animal origin, especially in Europe. The Regulation of European Community No 1099/2009 provides requirements for poultry stunning that associate with animal welfare as a means to minimize the pain and suffering from the slaughter. Improper application of callousness should produce low-quality meat, and significant industry losses. This Research aimed to evaluate the impacts on the quality of meat from turkeys, applying electrical stunning parameters established in the Regulation No 1099/2009 of the Council of 24 September 2009. Was applied an outline with 8 tests set equidistantly to frequency, and set parameters for current and voltage, and a control test. Were conducted qualitative assessments of hematoms and bruises / fractures in carcasses, hematoms, blood splashed and bleeding in turkey breast, and quantitative pH, color (L *), water holding capacity and shear force in turkey breast. The individual assessments showed no significant difference (p>0,05). In multivariate cluster analysis was the formation of two distinct groups: group 1 - 50 Hz to 200 Hz (low frequency) and group 2 - 633 Hz to 1500 Hz (high frequency), which showed significant difference (p= 0,016). In principal component analysis multivariate, the group 1 tend to have a higher incidence of bruising, blood splashed, bleeding and water holding capacity in breast turkeys, and bruises / fractures and hematoms on carcasses. The Group 2 tends to have a lower incidence of these parameters, and higher pH values, shear force and color (L *). Positive correlation was obtained for the parameters pH and shear force (r= 0.7506, p=0.0198); bleeding and splashed blood (r= 0.8811, p= 0.0017), and negative correlation to color (L*) and splashed blood on breast (r= -0.7889; p= 0.0115); breast hematoms and shear force (r= -0.7844; p= 0.0123). It has been observed that at lower frequencies stunning tends to have higher incidence of defects in the carcasses and turkey breast. The use of high frequencies in stunning, create smaller quantity of trimming, and an increase in turkey breast volume produced, with a financial gain of approximately R$250,000.00 / year. Moreover, there is no need increase the workers to do the trimming tasks and, therefore, higher financial results for companies. Therefore, we recommend the use of high frequencies in the stunning of turkeys.

Desenvolvimento de um método para correção de curvas de desempenho em bombas centrífugas submersas operando com fluidos viscosos

Electrical Submersible Pump (ESP) is used as an artificial lift technique. However, pumping viscous oil is generally associated with low Reynolds number flows. This condition leads to a performance degradation respect to the performance expected from the regular operation with water that most of the centrifugal pumps are originally designed for. These issues are considered in this investigation through a numerical study of the flow in two different multistage, semi-axial type ESPs. This investigation is carried out numerically using a Computational Fluid Dynamics (CFD) package, where the transient RANS equations are solved numerically. The turbulence is modeled using the SST model. Head curves for several operating conditions are compared with manufacturer’s curves and experimental data for a three-stage ESP, showing good agreement for a wide range of fluid viscosities and rotational speeds. Dimensionless numbers (n, n, n e Re) are used to investigate performance degradation of the ESPs. In addition, flow phenomena through the impellers of the ESPs are investigated using flow field from numerical results. Results show that performance degradation is directly related to rotational Reynolds number, Re. In addition, it was verified that performance degradation occurs for constant normalized specific speedn, which shows that performance degradation occurs similarly for different centrifugal pumps. Moreover, experimental data and numerical results agreed with a correlation from literature between head and flow correction factors proposed by Stepanoff (1967). A definition of modified Reynolds number was proposed and relates the head correction factor to viscosity. A correlation between head correction factor and the modified Reynolds number was proposed, which agreed well with numerical and experimental data. Then, a method to predict performance degradation based on the previous correlations was proposed. This method was compared with others from literature. In general, results and conclusions from this work can also be useful to bring more information about the flow of highly viscous fluids in pumps, especially in semi-axial, multistage ESPs.