Solutocapillary Convection in Spherical Shells with a Receding and Deforming Interface

A theoretical and computational study of solutocapillary driven Marangoni instabilities in small spherical shells is presented. The shells contain a binary fluid with an evaporating solvent. The viscosity is a strong function of the solvent concentration, the inner surface of the shell is assumed impermeable and stress free, while non-linear boundary conditions are modeled and prescribed at the receding outer boundary. A time-dependent diffusive state is possible and may lose stability through the Marangoni mechanism due to surface tension dependence on solvent concentration (buoyant forces are negligible in this micro-scale problem). The Capillary number (Ca) provides a measure of the deviation from sphericity and to leading order in the limit Ca → 0 the outer surface evolves with time in a convective state as it does in the diffusive state. We model the motion in this limit and compute supercritical, nonlinear, time-dependent, axisymmetric and three-dimensional, infinite Schmidt number solutocapillary convection. The normal stress balance imposes compatibility restrictions and allows two admissible states: axisymmetric hemispherical convection and three-dimensional solutions exhibiting cubic symmetry. We employ global mass conservation to compute upper bounds on the companion O(Ca) free surface deformations

Inheritance pattern of Qualitative traits, Genetic analysis and association of yield attributes in F2 populations of Rice (Oryza sativa)

Understanding the extent of genetic variability within the segregating generations is crucial for identifying superior segregants with high yield and better market acceptability. Thus, the present study was carried out to quantify the extent of genetic variation available in the segregating population of rice. Three crosses, viz., CO 55 × IC 457996, CO 55 × IC 464685, and CO 55 × IC 115439 were evaluated using a non-randomized experimental design for six yield attributing and two physical grain quality traits in F2 generation. The inheritance pattern of basal leaf sheath colour and grain colour in CO 55 × IC 115439 indicate digenic complementary gene interaction (9:7), whereas grain colour in CO 55 × IC 464685 exhibits inhibitory gene action (13:3). The positively skewed nature of productive tillers per plant and single-plant yield in the F2 segregants emphasizes the need for intensive selection to facilitate rapid improvement due to the influence of complementary gene action. Moderate to high GCV with high heritability and GAM for traits such as plant height, productive tillers per plant, hundred seed weight, grain width, and single-plant yield in the F2 segregants underscore the prevalence of additive gene action and thus provide the most effective condition for simple phenotypic selection. Moreover, productive tillers per plant and single-plant yield showed a strong positive association in all the crosses. Therefore, productive tillers per plant can be considered an indicator trait when selecting high-yielding segregants for grain yield improvement

The Stones Project: Subsea, Umbilical, Riser and Flowline Systems

Abstract The Stones project is located in the Walker Ridge (WR) area approximately 200 miles due south of New Orleans in 9,500 feet of water. The host facility is a Floating Production Storage and Offloading (FPSO) vessel with a disconnectable buoy that allows the FPSO to move off site in a hurricane event. Subsea wells are located in daisy chained drill centers that tie back to the FPSO via dual Steel Lazy Wave Risers and subsea flowlines. Other key subsea infrastructure includes two production manifolds, eight subsea trees, umbilicals and an artificial lift system. Produced gas is exported through a lateral pipeline which ties into the Walker Ridge Gathering System located in WR 457. This paper provides an overview of the subsea and flowline system, overall flow assurance strategy, a description of the gas export pipeline, and challenges encountered during execution of the project. Key challenges include the water depth at the site, furrowed seabed, metocean conditions, slope stability along the Sigsbee escarpment, the disconnectable buoy, flow assurance and changes mid execution due to deep and difficult wells.</jats:p