Force calculation on walls and embedded particles in multiparticle collision dynamics simulations

Colloidal solutions posses a wide range of time and length scales, so that it is unfeasible to keep track of all of them within a single simulation. As a consequence some form of coarse-graining must be applied. In this work we use the Multi-Particle Collision Dynamics scheme. We describe a particular implementation of no-slip boundary conditions upon a solid surface, capable of providing correct force s on the solid bypassing the calculation of the velocity profile or the stre ss tensor in the fluid near the surface. As an application we measure the friction on a spherical particle, when it is placed in a bulk fluid and when it is confined in a slit. We show that the implementation of the no-slip boundary conditions leads to an enhanced Ensko g friction, which can be understood analytically. Because of the long-range nature of hydrodynamic interactions, the Stokes friction obtained from the simulations is sensitive of the simulation box size. We address this topic for the slit geometry, showing that that the dependence on the system size differs very much from what is expected in a 3D system, where periodic boundary conditions are used in all directions.Comment: To appear in Physical Review

Compressed food components to minimize storage space

Compressed food products to minimize storage space for military application

Questions For Baptists

https://digitalcommons.acu.edu/crs_books/1410/thumbnail.jp

Stability and error analysis of a splitting method using Robin–Robin coupling applied to a fluid–structure interaction problem

We analyze a splitting method for a canonical fluid structure interaction problem. The splittling method uses a Robin-Robin boundary condition, explicit strategy. We prove the method is stable and, furthermore, we provide an error estimate that shows the error at the final time T is O( √ T ∆t) where ∆t is the time step

Polypropylene Mesh Predicts Mesh/Suture Exposure After Sacrocolpopexy Independent of Known Risk Factors

Objective(s) The aim of this study was to determine if ultralightweight polypropylene mesh reduced the risk of mesh/suture exposure after sacrocolpopexy compared with heavier-weighted polypropylene. Methods Bivariate and multivariate analyses were used to interpret data from 133 cases and 261 control subjects to evaluate independent predictors of mesh/suture exposure after sacrocolpopexy from 2003 to 2013. Results Multivariate logistic regression revealed that prior surgery for incontinence (odds ratio [OR], 2.87; 95% confidence interval [CI], 1.19–6.96), porcine acellular cross-linked collagen matrix with medium-weight polypropylene mesh (OR, 4.95; 95% CI, 1.70–14.42), other polypropylene mesh (OR, 6.73; 95% CI, 1.12–40.63), nonabsorbable braided suture for vaginal mesh attachment (OR, 4.52; 95% CI, 1.53–15.37), and immediate perioperative complications (OR, 3.64; 95% CI, 1.53–13.37) were independent risk factors for mesh/suture exposure. After multivariate analysis, ultralightweight polypropylene mesh was no longer associated with decreased rates of mesh/suture exposure after controlling for known risk factors identified during bivariate analysis (P = 0.423). Conclusions Both mesh choice and suture selection remained independent predictors of mesh/suture exposure, with heavier meshes increasing and monofilament suture decreasing rates of mesh/suture exposure. Based on this study, surgeons may consider use of delayed-absorbable, monofilament suture over nonabsorbable braided suture for attachment of vaginal mesh to reduce the risk of mesh/suture exposure when using mesh

Archaeological Excavation of the Priest Quarters, Mission San Francisco de la Espada, 41BX4, San Antonio, Texas

The following report is the result of two projects completed by the Center for Archaeological Research, of The University of Texas at San Antonio for San Francisco de la Espada/Catholic Diocese of San Antonio and J. T. Michel, Inc., under Texas Historical Commission Permit Number 2076. The investigations were conducted at Mission San Francisco de la Espada, San Antonio, Bexar County, Texas (41BX4). The initial investigation was conducted in November 1998, prior to the planned installation of electrical lines along the southwest corner of the Convento (complex of structures grouped around a patio area), while the additional excavations of July and August 1999, were conducted to coincide with restoration work being conducted on the Chapel and Priest Quarters. Additional investigations were also conducted in July and August 1999, along the southern-most walls of the Priest Quarters prior to the installation of new foundation piers and beams designed to stabilize the existing wall foundations. The excavations affected the exterior walls of the Convento; an area 1 m wide by 1 m deep, and 25.2 m long. The monitoring portion conducted in October and November 1999, focused on unexcavated areas along walls that were exposed during the stabilization work. During the course of the investigations exposed foundations and features were documented, with specific attention to mode of construction and condition. The excavations resulted in the recovery of a variety of Colonial and post-Colonial artifacts including ceramics, lithics, glass, metal, and animal bone. These excavations which supplied the opportunity for the recovery of valuable cultural data, also revealed noticeable differences in wall foundation construction and reconstruction, which strongly suggest at least two distinct construction sequences