We examined the sensitivity of microtubule spools to transport velocity. Perhaps surprisingly, we determined that the steady-state number and size of spools remained constant over a seven-fold range of velocities. Our data on the kinetics of spool assembly further suggest that the main mechanisms underlying spool growth vary during assembly.

The present work is concerned with the formulation of a continuum theory of viral DNA packaging based on a director (eld representation of the encapsidated DNA. The point values of the director (eld give the local direction and density of the DNA. The continuity of the DNA strand requires that the director (eld be divergence-free and tangent to the capsid wall. The energy of the DNA is de(ned a...

The aim of this paper is to present the SPOOL design repository, which is the foundation of the SPOOL software engineering environment. The SPOOL design repository is a practical implementation of the UML metamodel, and is used to store detailed design-level information that is extracted from the source code of industrial systems. Its internal mechanisms and related tools provide functionalitie...

A simple model for the kinetic frictional force on an object sliding across a surface is adopted in introductory physics. Its magnitude given by constant coefficient of friction multiplied normal exerted surface, and points opposite direction that slides relative to surface. In contrast, standard static more complicated. There no formula its magnitude, but instead it can vary from zero up some ...

Hydraulic systems, as power sources and transmissions, offer many advantages over electromechanical or purely mechanical counterparts in terms of power density, flexibility, and portability. Many hydraulic systems require touching and contacting the physical environments; and many of these systems are directly controlled by humans. If hydraulic systems are passive, they would be both safer to i...

The 62.5/125/250 micron optical fiber manufactured by Lucent SFT was tested for gamma radiation resistance at the NASA Goddard Space Flight Center Cobalt chamber. The fiber was tested with 1300 nm light, at 20.7 rads/min and 5 rads/min at –25°C and at 32.3 rads/min and 5 rads/min at +25°C. Data was recorded during exposure until the attenuation reached levels below that of the optical detection...

This paper presents tracking control performances of a piezostack direct drive valve (PDDV) operating at various temperatures. As a first step, a spool valve and valve system are designed to be operated by the piezoactuator. In this study, the stacked piezoelectric actuator, which is lead–zirconate–titanate (PZT) ceramic is used for control of spool displacement. An aerogel is used for heat ins...

Construction of Industrial facilities involves a substantial amount of piping. Pipe spools are usually pre-fabricated from a number of raw pipes and pipe fittings (e.g. elbows, flanges, tees, etc.) in fabrication shops. Pipe spool fabrication is often affected by various disruptions from within or outside the shops. Previous research mainly focuses on shop layouts, dispatching rules, buffer loc...