Morphological variation was analyzed in wild, managed in situ, and cultivated populations of the columnar cactus Stenocereus stellatus in central Mexico. The purpose was to evaluate whether morphological divergence between manipulated and wild populations has resulted from domestication processes. Variation of 23 morphological characters was analyzed among 324 individuals from 19 populations of the Tehuacán Valley and La Mixteca Baja. Multivariate statistical analyses were used to group individuals and populations according to their morphological similarity. Individuals grouped according to the way of management and fruit characteristics were the most relevant for grouping. Within each region, sweet fruits with pulp colors other than red were more frequent in cultivated populations, where fruits were also larger, contained more and bigger seeds, and had thinner peel and fewer spines than fruits from wild individuals. Phenotypes common in managed in situ and cultivated populations generally occur in the wild but in lower frequencies. Artificial selection has thus operated by enhancing and maintaining desirable rare phenotypes in managed in situ and cultivated populations, causing divergent patterns of morphological variation from wild populations. Cultivation has caused the strongest level of divergence, but divergence has also been significant with management of wild populations in situ.

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The injection rate curve is an important input parameter in the thermodynamic diagnosis and in the predictive models, and it can also be used to simulate fuel sprays under different operating conditions. In this work, a zero-dimensional fuel injection rate model is proposed from experimental data obtained from a common-rail injection system with two solenoidoperated injectors. The model proposed is a useful tool when the internal component's dimensions of the injector are unknown. The presented model only requires the injection pressure, the injector energization signal, the total fuel mass consumed per stroke, the geometry and the holes number of the fuel injector and, finally, some physical properties of fuel. The model has been applied to two different solenoid-operated injectors and two fuels. The comparative results between the experimental and the modelled fuel injection rate show excellent results despite the simplicity of the experimental data requirements. The effects of the introduction of the modelled and measured fuel injection rate in a thermodynamic diagnostic tool are shown. This proposed model can be a useful, simple and alternative tool for estimating rates of injection without the need to carry out a test of the rate of injection. *Revised Manuscript with No Changes Marked Click here to view linked References