52,194 research outputs found

    Study of full implicit petroleum engineering finite volume scheme for compressible two phase flow in porous media

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    An industrial scheme, to simulate the two compressible phase flow in porous media, consists in a finite volume method together with a phase-by-phase upstream scheme. The implicit finite volume scheme satisfies industrial constraints of robustness. We show that the proposed scheme satisfy the maximum principle for the saturation, a discrete energy estimate on the pressures and a function of the saturation that denote capillary terms. These stabilities results allow us to derive the convergence of a subsequence to a weak solution of the continuous equations as the size of the discretization tends to zero. The proof is given for the complete system when the density of the each phase depends on the own pressure

    Revising contract sum: the employer right to set-off payment

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    Until today, dispute concerning payment had long plague the construction industry. Despite, on what was written on contract on agreed contract price, the employer always dissatisfied with contractor's work. This led the employer to reject payment issued by the Architect by withholding and later setting off payment in interim certificate. This kind of action had caused the contractor to bring action against the employer in reclaiming the money due to them. On the other hand, the employer will counterclaim against the contractor by putting up excusable reasons in delaying payment. Set off always misconstrued as same as counterclaim or abatement. In related cases, decisions decided by the judge put conditions in construing the terms. The research also concluded that defective works was the key factor of why the employer setting off interim payment to the contractor. In this regard, the Court will depend solely on precedent cases available and the most prominently the provision of set off available in contract. Hence, the employer right to set - off payment must be made according to contract available and not blindly done

    Discriminating between nesting and non-nesting habitat in a vulnerable bird species: Implications for behavioural ecology

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    Nowadays, partitioning amongst nesting and non-nesting habitats is not much studied. Here, I investigate whether or not the turtle dove (Streptopelia turtur) nesting habitats overlap with those used for other purposes in a North African agroforestry system. A total of 33 nest points and 33 turtle dove presence points were considered. The study, conducted in May to June 2017, attempted to determine the factors that may play a role in discriminating between the nesting habitats and non-nesting habitats. I used a linear discriminant analysis (LDA) to test the relevance of proximity of food resources, forest edge and human presence variables in the distribution of the species. The results show substantial segregation in the habitats selected for nesting and those selected for other uses [average distance was 1129.69 ± 169.40 m (n = 66) with a maximum of 1518.6 m and a minimum of 617.72 m], with selection depending primarily on the proximity to forest edge and feeding areas. I discuss these findings and their implications on behavioural ecology and future researches of this vulnerable species. I suggest guidelines for future studies that will seek to better understand the behavioural dynamics of turtle doves in the Mediterranean agroforestry systems. This can only be done when disturbance covariates, such as: (i) forest logging, (ii) cereal harvesting and (iii) hunting and predation pressures, were imperatively taken into account
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