12,972 research outputs found
Modified spiral wound retaining ring
A spiral wound retaining ring with angled ends is described. The ring is crimped at the same angle as the ring ends to maintain a constant thickness dimension. The angling of the ends of the ring and crimp allow the ends to be positioned closer together while maintaining enough clearance to enable insertion and removal of the ring. By reducing the separation distance between the ends a stronger ring results since the double layer area of the ring is maximized
Tarski monoids: Matui's spatial realization theorem
We introduce a class of inverse monoids, called Tarski monoids, that can be
regarded as non-commutative generalizations of the unique countable, atomless
Boolean algebra. These inverse monoids are related to a class of etale
topological groupoids under a non-commutative generalization of classical Stone
duality and, significantly, they arise naturally in the theory of dynamical
systems as developed by Matui. We are thereby able to reinterpret a theorem of
Matui on a class of \'etale groupoids as an equivalent theorem about a class of
Tarski monoids: two simple Tarski monoids are isomorphic if and only if their
groups of units are isomorphic. The inverse monoids in question may also be
viewed as countably infinite generalizations of finite symmetric inverse
monoids. Their groups of units therefore generalize the finite symmetric groups
and include amongst their number the classical Thompson groups.Comment: arXiv admin note: text overlap with arXiv:1407.147
Shell tile thermal protection system
A reusable, externally applied thermal protection system for use on aerospace vehicles subject to high thermal and mechanical stresses utilizes a shell tile structure which effectively separates its primary functions as an insulator and load absorber. The tile consists of structurally strong upper and lower metallic shells manufactured from materials meeting the thermal and structural requirements incident to tile placement on the spacecraft. A lightweight, high temperature package of insulation is utilized in the upper shell while a lightweight, low temperature insulation is utilized in the lower shell. Assembly of the tile which is facilitated by a self-locking mechanism, may occur subsequent to installation of the lower shell on the spacecraft structural skin
Aircraft landing dynamics facility carriage weld test program
A welded tubular structure constructed of low alloy high strength quenched and tempered steel was tested. The consistency of the mechanical strengths and chemical composition and the degree of difficulty of obtaining full strength welds with these steels is characterized. The results of constructing and testing two typical connections which are used in the structure design are reported
Safety hazards associated with the charging of lithium/sulfur dioxide cells
A continuing research program to assess the responses of spirally wound, lithium/sulfur dioxide cells to charging as functions of charging current, temperature, and cell condition prior to charging is described. Partially discharged cells that are charged at currents greater than one ampere explode with the time to explosion inversely proportional to the charging current. Cells charged at currents of less than one ampere may fail in one of several modes. The data allows an empirical prediction of when certain cells will fail given a constant charging current
Re Saint John (City of) and Saint John Fire Fighters\u27 Association, IAFF Local 771 (Davidson)
Union grievance on behalf of the Grievor alleging that he was hired and subsequently fired without due process, contrary to the 2001-2003 Collective Agreement between the parties, and seeking full redress. At the outset of the hearing in this matter the parties agreed that this Board of Arbitration is properly constituted and, subject to the City\u27s preliminary objection, properly seized of this matter. The City made a preliminary objection to the jurisdiction of this Board of Arbitration to hear this matter based on the allegation that the Grievor was never an employee of the City; i.e., that he was never hired. The parties agreed that the Board would hear evidence and argument on the preliminary objection and rule on it before dealing with the allegation that the Grievor was improperly discharged
Preprofessional curriculum in preparation for doctor of pharmacy educational programs
The preprofessional pharmacy curriculum provides the foundation for the professional curriculum. Basic requirements are noted in the ACPE Standards and Guidelines, but there is considerable variation in the preprofessional curriculum requirements for entry into doctor of pharmacy programs in the United States. Changes in higher education, pharmacy practice, and health care continue to drive the need to evaluate the preprofessional curriculum. The objectives of this white paper were to create model preprofessional curricula that would enable students to be successful during and after entry into the professional curriculum. Using an evidence-based approach where possible, a number of factors were found to be associated with academic success during a pharmacy program and on licensing examinations. These data and other information were used to create 2 preprofessional curricular models that include the development of general and discipline-specific abilities. Challenges remain in accurately evaluating the abilities and attributes of applicants and the impact of those abilities and attributes on their success as a student and a practitioner. Colleges and schools of pharmacy should consider adopting a more consistent preprofessional curriculum on a national level. This preprofessional curriculum should be multi-dimensional, based on needs for future practice, and revised over time
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