Application of sutures between expanded polytetrafluoroethylene (ePTFE) dural substitutes and the dura mater is often frustrating in posterior fossa surgery because of the difficulty in holding the elastic graft in a deep and narrow field. To resolve this problem, we have developed a boat-shaped graft made from a triangular ePTFE sheet by pinching each angle using a suture. Formation of standin...

This paper presents a numerical comparison of two regularizations of the Euler equations, namely, the vortex blob regularization and regularization by physical viscosity. The initial condition is a flat vortex sheet whose vorticity has been smoothed by convolution. The sheet rolls up into a vortex pair. We compute the frequency of oscillations in the core vorticity and scale it using results fo...

The ability of carbon to exist in many forms across dimensions has spawned search in exploring newer allotropes consisting of either, different networks of polygons or rings. While research on various 3D phases of carbon has been extensive, 2D allotropes formed from stable rings are yet to be unearthed. Here, we report a new sp(2) hybridized two-dimensional allotrope consisting of continuous 5-...

It is shown that if a doubly-infinite vortex sheet has cylindrical shape and strength distributions at some initial time, then this property is retained in its subsequent evolution. It is also shown that in planes normal to the generator of the cylindrical sheet geometry, the nonlinear evolution of the sheet is the same as that of an equivalent strictly two-dimensional sheet motion. These prope...

Aquaporin (Aqp) embedded membranes have become a topic of recent research due to the superior selectivity of Aqp to water and its acceptable flux. Most researchers have utilized Aqp membranes for water purification purposes such as reverse and forward osmosis desalination of sea and brackish water and wastewater treatment. This paper investigated the permeation of aqueous ethanol across commerc...

Large vibrating plates are used as thunder sheets in orchestras. We have extended the use of flat plates by cementing a flat panel electroacoustic transducer on a large brass sheet. Because of the thickness of the panel, the output is subject to nonlinear distortion. When combined with a real-time input and signal processing algorithm, the active brass plate can become an effective musical inst...

Methods are developed to estimate the adhesion and surface free energies of compliant materials from the contact deformations of cylindrical lenses with flat sheets. Some important differences are found between the cylindrical contact studied here and the widely studied geometry of spherical contact. For example, while the pull-off force is completely independent of the elastic constants (K) of...

The Paper machine vacuum system is an important operation for dewatering of wet web to increase percentage solids in web. There are various models available to assess the influence of vacuum on the above parameters. In this present investigation the steady state model is discussed for estimating optimum vacuum load in flat boxes of Fourdrinier paper machine as the flat boxes are the main compon...

Design of sheet metal products can be a complex and elaborate process. However, many important aspects of the manufacturing characteristics of a product are already determined at the early stages of the design. This paper reports on a system for conceptual design of sheet metal products by sketching, based on principles of early incorporation of CAD, imprecise analysis, and natural, incontext i...

Designing flat sheets that can be made to deform into 3D shapes is an area of intense research with applications in micromachines, soft robotics, and medical implants. Thus far, such were designed adopt a single target shape. Here, we show through anisotropic deformation applied inhomogenously throughout sheet, it possible design sheet multiple surface geometries upon different actuations. The ...