Abstract

Although farm biosecurity reduces the risk of disease spread among livestock, this knowledge is not always applied. Farmers’ application of disease preventive measures is expected to depend on many things, e.g. whether they consider disease prevention possible and demographic factors. In this study, Swedish livestock farmers’ perspectives on occurrence, control and communication related to infectious livestock diseases were investigated. A questionnaire study was performed in 2012–2013, and included responses from almost 2000 livestock farmers with cattle, pigs, sheep or goats. Associations between responses and factors related to herd type and demography were investigated using multivariable regression models. Results showed a strong general agreement among farmers that disease prevention is important. However, results also showed differing opinions among farmers. For example, female farmers indicated higher levels of perceived knowledge of disease spread and a stronger belief that they can prevent disease introduction. Results indicate that farmers who believe they have the necessary knowledge, have stronger sense of control and also demand that others take responsibility to prevent spread. Furthermore, dairy farmers were more likely to respond that repeated exposure to infections could be beneficial for animal health. The number of perceived disease outbreaks was also higher among these farmers. Regarding government issued compensation to farmers in case of outbreaks, a wide range of opinions were recorded. Responses confirm that the farm veterinarian is an important source of disease information and several different communication channels are needed to reach farmers. In conclusion, our results show that factors such as gender, education level and age influence how prevention and occurrence of disease outbreaks are perceived and best communicated. We suggest that efforts are made to increase knowledge about disease prevention among farmers and veterinary practitioners and that farm veterinarians should be encouraged to motivate farmers to strengthen farm biosecurity.

Abstract

Spring-in in composite manufacturing is a relevant non desired effect that complicates the industrialization process of new composite parts. Geometrical deviations of the part with regard to the nominal dimensions  hinders posterior assembly operations or even can cause unconformities (part rejection). Although some correction operations may be introduced in the assembly method to absorb these deviations, a preferred approach is to compensate the tool geometry to produce the part within tolerances.

This contribution presents a methodology that, in an iterative process, links a MEF simulation workflow for the prediction of process induced distortions, a routine to compute deviations and updating tool cavity surface, till the deviations are within a target tolerance. The spring-in calculation engine is implemented in Abaqus Standard with specific subroutines to model resin curing kinetics, heat generation, cure dependent mechanical constitutive model with consideration of thermal expansion and cure shrinkage, and specific strategies to simulate the tool/part interactions. The spring-in engine is incorporated in an external Python manager in charge of post-processing results, updating the mesh and launching the executions. This methodology aims at proposing a modified tool surface geometry that could be used to build a compensated tool at first, reducing industrialization time and cost.