Quantifying the biodegradation rate of organic contaminants is important in designing and evaluating bioremediation treatments and facilities. To study the effects of temperature and forced aeration on the biodegradation rate, a soil collected from a pipeline break site and contaminated with crude oil was bioremediated in a field‐operated bioreactor near Nevis, AB, Canada under four treatments: a control with ambient temperature (averaging 20°C) and no forced aeration; heating alone (averaging 35°C); forced aeration alone (air flux was 0.4 1 min−1 m−2); and both heating and forced aeration. The soil was aggregated, amended with N and P fertilizers and packed 15‐cm deep to a bulk density of 0.65 Mg m−3 in the bioreactor. The effect of temperature on the biodegradation rate of hydrocarbons was also studied under laboratory conditions for temperatures ranging from 5 to 50°C. Both heating and forced aeration significantly affected the biodegradation of hydrocarbons, but the effect of the former was greater. Under laboratory conditions, the biodegradation rate of hydrocarbons increased with temperatures, peaking between 30 and 40°C. The half‐lives of the hydrocarbons remaining in soil in the field‐operated bioreactor were 105 d for both the heating alone and the heating and forced aeration treatments, 182 d for the forced aeration treatment and 248 d for the control.
In this paper, we propose a general framework for constructing IGA-suitable planar B-spline parameterizations from given complex CAD boundaries consisting of a set of B-spline curves. Instead of forming the computational domain by a simple boundary, planar domains with high genus and more complex boundary curves are considered. Firstly, some pre-processing operations including Bézier extraction and subdivision are performed on each boundary curve in order to generate a high-quality planar parameterization; then a robust planar domain partition framework is proposed to construct high-quality patch-meshing results with few singularities from the discrete boundary formed by connecting the end points of the resulting boundary segments. After the topology information generation of quadrilateral decomposition, the optimal placement of interior Bézier curves corresponding to the interior edges of the quadrangulation is constructed by a global optimization method to achieve a patch-partition with high quality. Finally, after the imposition of C 1 /G 1 -continuity constraints on the interface of neighboring Bézier patches with respect to each quad in the quadrangulation, the high-quality Bézier patch parameterization is obtained by a C 1constrained local optimization method to achieve uniform and orthogonal iso-parametric structures while keeping the continuity conditions between patches. The efficiency and robustness of the proposed method are demonstrated by several examples which are compared to results obtained by the skeleton-based parameterization approach.with respect to each quad in the quadrangulation achieving high-quality iso-parametric structures while keeping the continuity constraints between patches.The rest of the paper is structured as follows. Some related work on parameterization of the computational domain are reviewed in Section 2. Preliminary properties of Bernstein polynomials and an overview of the proposed framework is given in Section 3. Several pre-processing operations, including Bézier extraction and Bézier subdivision, are presented in Section 4. Section 5 describes the topology information generation and interior Bézier boundary construction for the quadrilateral high-quality patch partition by the global optimization approach. A local optimization method for high-quality Bézier patch parameterizations with C 1 /G 1 continuity constraints is proposed in Section 6. Some parameterization examples are presented in Section 7. To demsonstrate the effectiveness of the proposed method, the results are compared to results obtained by the skeletonbased approach. Finally, we conclude this paper and outline future work in Section 8.
Related workCurrently, the related work on parameterization of the computational domain in IGA can be classified into four categories: (1) analysis-aware optimal parameterization; (2) volumetric spline parameterization from boundary triangulation; (3) analysis-suitable planar parameterization; (4) analysis-suitable volumetric parameterization from spline boundaries .Analysi...
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