A constrained pressure-temperature residual (CPTR) method for non-isothermal multiphase flow in porous media

For both isothermal and thermal petroleum reservoir simulation, the Constrained Pressure Residual (CPR) method is the industry-standard preconditioner. This method is a two-stage process involving the solution of a restricted pressure system. While initially designed for the isothermal case, CPR is also the standard for thermal cases. However, its treatment of the energy conservation equation does not incorporate heat diffusion, which is often dominant in thermal cases. In this paper, we present an extension of CPR: the Constrained Pressure-Temperature Residual (CPTR) method, where a restricted pressure-temperature system is solved in the first stage. In previous work, we introduced a block preconditioner with an efficient Schur complement approximation for a pressure-temperature system. Here, we extend this method for multiphase flow as the first stage of CPTR. The algorithmic performance of different two-stage preconditioners is evaluated for reservoir simulation test cases.Comment: 28 pages, 2 figures. Sources/sinks description in arXiv:1902.0009

Dairy Farm Revenue Insurance: Is the Application Viable?

Risk and Uncertainty,

An Examination of US Consumer Pet and Veterinary Expenditures, 1980-1999

The veterinary medical profession touches nearly everyone's life, either directly or indirectly. An estimated 58.3% of US households own pets (AVMA, 2002), and most people consume livestock products in the form of meat, dairy products, wool, or leather. The health and well being of all these animals depend heavily on relationships with veterinarians. Veterinarians also contribute to public health through the FDA, CDC, USDA, and numerous other government agencies at the federal, state, and local levels. Issues of primary concern include food safety, biosecurity, and the numerous emerging (and re-emerging) infectious diseases that are zoonotic in nature. Finally, veterinarians have an additional impact through their research contributions. Virtually all of the laboratory animals used in research are raised, housed, and managed under the care of veterinarians, and veterinary researchers regularly provide valuable contributions to the knowledge base in the biomedical sciences. This study was designed to assess the general trends in pet and veterinary expenditures as well as factors associated with pet ownership and expenditures on veterinary medical services. Providing such key information on the sector of greatest economic importance will enhance the probability of sustained economic viability in the veterinary medical profession as a whole.Health Economics and Policy,

A complex network of interactions between mitotic kinases, phosphatases and ESCRT proteins regulates septation and membrane trafficking in S. pombe

Cytokinesis and cell separation are critical events in the cell cycle. We show that Endosomal Sorting Complex Required for Transport (ESCRT) genes are required for cell separation in Schizosaccharomyces pombe. We identify genetic interactions between ESCRT proteins and polo and aurora kinases and Cdc14 phosphatase that manifest as impaired growth and exacerbated defects in septation, suggesting that the encoded proteins function together to control these processes. Furthermore, we observed defective endosomal sorting in mutants of plo1, ark1 and clp1, as has been reported for ESCRT mutants, consistent with a role for these kinases in the control of ESCRT function in membrane traffic. Multiple observations indicate functional interplay between polo and ESCRT components: firstly, two-hybrid in vivo interactions are reported between Plo1p and Sst4p, Vps28p, Vps25p, Vps20p and Vps32p; secondly, co-immunoprecipitation of human homologues of Vps20p, Vps32p, Vps24p and Vps2p by human Plk1; and thirdly, in vitro phosphorylation of budding yeast Vps32p and Vps20p by polo kinase. Two-hybrid analyses also identified interactions between Ark1p and Vps20p and Vps32p, and Clp1p and Vps28p. These experiments indicate a network of interactions between ESCRT proteins, plo1, ark1 and clp1 that coordinate membrane trafficking and cell separation in fission yeast

The Finite Field Multi-Way Relay Channel with Correlated Sources: The Three-User Case

The three-user finite field multi-way relay channel with correlated sources is considered. The three users generate possibly correlated messages, and each user is to transmit its message to the two other users reliably in the Shannon sense. As there is no direct link among the users, communication is carried out via a relay, and the link from the users to the relay and those from the relay to the users are finite field adder channels with additive noise of arbitrary distribution. The problem is to determine the set of all possible achievable rates, defined as channel uses per source symbol for reliable communication. For two classes of source/channel combinations, the solution is obtained using Slepian-Wolf source coding combined with functional-decode-forward channel coding.Comment: to be presented at ISIT 201

Incorporating Environmentally Compliant Manure Nutrient Disposal Costs into Least-Cost Livestock Ration Formulation

Livestock rations are formulated to minimize feed cost subject to nutritional requirements for a target performance level, which ignores the potentially substantial cost of disposing of nutrients fed in excess of nutritional requirements. We incorporate nutrient disposal costs into a modified least-cost ration formulation model to arrive at a joint least-cost decision that minimizes the sum of feed and net nutrient disposal costs. The method is demonstrated with phosphorus disposal costs on a representative dairy farm. Herd size, land availability and proximity, crop rotation, and initial soil phosphorus content are shown to be important in determining phosphorus disposal costs.environmental compliance, linear programming, livestock rations, manure disposal, Agribusiness, Environmental Economics and Policy, Livestock Production/Industries, C61, Q12, Q52,

Summary Data from the Sixth AIAA Computational Fluid Dynamics Drag Prediction Workshop: Code Verification

Results from the Sixth AIAA CFD Drag Prediction Workshop (DPW-VI), Case 1 Code Verification are presented. This test case is for the turbulent flow over a 2D NACA 0012 airfoil using Reynolds-Averaged Navier-Stokes (RANS) turbulence models. A numerical benchmark solution is available for the standard Spalart-Allmaras (SA) turbulence model that can be used for code verification purposes, i.e., to verify that the numerical algorithms employed are consistent and that there are no programming mistakes in the software. For the Case 1 code verification study, there were 31 data submissions from 16 teams: 23 with the SA model (using various versions), 4 with the k-omega SST model (two variants), and one each with k-kl, k-epsilon, an explicit algebraic Reynolds stress model, and the lattice Boltzmann method (LBM) with very large eddy simulation (VLES). Various grid types were employed including structured, unstructured, Cartesian, and adapted grids. The benchmark numerical solution was deemed to be the correct solution for the 21 submissions with the standard SA model, the SA-noft2 variant (without the ft2 term), and the SA-neg variant (designed to avoid nonphysical transient states in discrete settings). While many of these 21 submissions did demonstrate first-order convergence on the finer meshes, others showed either nonconvergent solutions in terms of the aerodynamic forces and moments or converged to the wrong answer. Results for this case highlight the continuing need for rigorous code verification to be conducted as a prerequisite for design, model validation, and analysis studies