On Connectivity Spaces

This paper presents some basic facts about the so-called connectivity spaces. In particular, it studies the generation of connectivity structures, the existence of limits and colimits in the main categories of connectivity spaces, the closed monoidal category structure given by the so-called tensor product on integral connectivity spaces; it defines homotopy for connectivity spaces and mention briefly related difficulties; it defines smash product of pointed integral connectivity spaces and shows that this operation results in a closed monoidal category with such spaces as objects. Then, it studies finite connectivity spaces, associating a directed acyclic graph with each such space and then defining a new numerical invariant for links: the connectivity order. Finally, it mentions the not very wellknown Brunn-Debrunner-Kanenobu theorem which asserts that every finite integral connectivity space can be represented by a link.Comment: 30 pages, 2 figure

Kategorie fuzzy množin

Category theory provides very useful tools for studying mathematical structures and phenomena. One of the structures that is studied in a category-theoretical manner are fuzzy sets. If we consider fuzzy sets as objects and set up certain kind of structure preserving mappings as morphisms, we can obtain a suitable category for our purposes. Goal of this work is to give an overview of preferably all important category-theoretical approaches to fuzzy sets that were done throughout relatively short history of category-theoretical modelling of fuzzy sets.Department of LogicKatedra logikyFaculty of ArtsFilozofická fakult

A study of the MT and LXX pluses in Jer 26-29 (33-36) : from textual to redactional implications

https://place.asburyseminary.edu/ecommonsatsdissertations/1945/thumbnail.jp

Central Florida Future, Vol. 11 No. 24, March 9, 1979

Colbourn says no to block fee plan; Photos of President Trevor Colbourn at the installation of the new University of Central Florida Pegasus seal on the Administration building; Model Senate team returns triumphant; Governor\u27s SUS budget deemed too low; Future Campus: Senate bill gives $110 to beer drinkers fraternity; Future Bulletin Board: Biology Club to offer student advisement; Gay services offer peer counseling; Iranian students; What now after revolt?; At last, spring break is finally here; Future Comment: State gets low grade in funding; Thanks to the greatest bunch of crazies ever (with of photo of Rick Lanham WFTU FM station manager); Sssplash! Spring Break \u2779 (with photos).https://stars.library.ucf.edu/centralfloridafuture/1355/thumbnail.jp

Magical motifs in the Book of Revelation

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Locating health and illness: a study of women's experiences in two contrasting Edinburgh neighbourhoods

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The use of sodium birnessite as a curing agent for liquid polysulfide sealant

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Manganese (IV) oxide phases are widely used as curing agents for polysulfide sealants. The manganese based curing agents, however, do not give a reproducible cure and this results in material waste. As the market for insulating glass applications is increasing, efficient curing becomes more significant both commercially and environmentally. The research described in this portfolio focuses on using a laboratory synthesised manganese (IV) oxide phase, sodium birnessite, as a polysulfide curing agent. The synthesis and full characterisation of sodium birnessite is described and its curing ability measured in terms of the following properties of the cured polysulfide: rate of cure. surface condition, hardness build-up, stress-strain data, low and high temperature properties. and moisture transmission. The results obtained are compared with those of polysulfides cured with a good commercial product. Different concentrations of curing agents, and types and concentrations of accelerators, plasticisers and inert diluents were investigated to optimise the curing process, reduce material use and product wastage. Sodium birnessite is an active and reliable curing agent when used at half of the concentration of the commercial agent in the presence and absence of inert diluents. Diluted sodium birnessite (1: 1 with inert diluent) cures polysulfide to levels comparable in terms of stress-strain properties, moisture transmission rate, hardness, surface condition, low- and high- temperature properties, and degree of polysulfide cross linking to that achieved with commercial agent. The mechanism of the curing of polysulfide with sodium birnessite, as with all curing agents is conversion of mercaptan groups -S-H into disulfide linkages (-S-S-). Sodium birnessite is a mixed oxidation state compound and its synthesis results in the inclusion of Mn 2+ in addition to Mn 4+ ions in the manganese oxide based lattice. A rationale for the improved curing ability of sodium birnessite is presented. It is based on the ability of Mn 2+ to create vacancies in the Mn4+ sub-lattice thus increasing the mobility of the Mn4 in the structure and its transport to the surface of the curing agent where the oxidation reduction reaction responsible for the cure takes place.Financial support was obtained from Twinstar Chemicals Ltd, and the Engineering and Physical Sciences Research Council (EPSRC