2 resultados para rate of torque development
em QSpace: Queen's University - Canada
Resumo:
Cyclododecane (CDD) is a waxy, solid cyclic hydrocarbon (C12H24) that sublimes at room temperature and possesses strong hydrophobicity. In paper conservation CDD is used principally as a temporary fixative of water-soluble media during aqueous treatments. Hydrophobicity, ease of reversibility, low toxicity, and absence of residues are reasons often cited for its use over alternative materials although the latter two claims continue to be debated in the literature. The sublimation rate has important implications for treatment planning as well as health and safety considerations given the dearth of reliable information on its toxicity and exposure limits. This study examined how the rate of sublimation is affected by fiber type, sizing, and surface finish as well as delivery in the molten phase and as a saturated solution in low boiling petroleum ether. The effect of warming the paper prior to application was also evaluated. Sublimation was monitored using gravimetric analysis after which samples were tested for residues with gas chromatography-flame ionization detection (GC-FID) to confirm complete sublimation. Water absorbency tests were conducted to determine whether this property is fully reestablished. Results suggested that the sublimation rate of CDD is affected minimally by all of the paper characteristics and application methods examined in this study. The main factors influencing the rate appear to be the thickness and mass of the CDD over a given surface area as well as temperature and ventilation. The GC-FID results showed that most of the CDD sublimed within several days of its disappearance from the paper surface regardless of the application method. Minimal changes occurred in the water absorbency of the samples following complete sublimation.
Resumo:
The objective of this thesis was to determine whether the establishment and operation of an archives services by the Hudson's Bay Company had an effect on the company's ability to carry out document repairs. Data collection methods included reviews of published material, archival records of the Hudson's Bay Company, and semi-structured interviews. The study found that the Hudson's Bay Company's commitment to operating a modern archives service in accordance with accepted archive administration practices had a substantial effect on its ability to carry out document repairs. The principled approach to repair, as practiced by the Public Record Office, was a major influence. A review of secondary sources placed this development squarely within the context of archival developments in 20th century England. Overall, the thesis findings add to the growing conversation about conservation history in England, in particular, archive conservation history as it occurred outside of the Public Record Office in the 20th century, by discussing how some methods of repair that were devised, adopted and extended by the Public Record Office in the 19th and 20th centuries were adopted and applied in the 20th century by a well-established business corporation.