Study Deck 4 Flashcards
- To create a copy with a format or structure different from the original, especially for preservation or access. 2. To migrate information from one carrier to another..
reformat
a substance used to fill the pores in fibrous materials. It allows paper to accept writing and printing inks.
sizing
A form of long, durable plant fibers used to make high-quality paper products. Alpha _____ may be derived from wood, linen, cotton, and other plant materials.
cellulose
a complex polymer that when left in groundwood pulp leads to the embrittlement of the paper created from such pulp and major source of acidity in paper
lignin
A chemically unstable strong paper made from wood pulp by a modified sulfate process. Normally brown, kraft paper can be bleached to tan or white. Commonly used to make grocery bags and for counter rolls.
kraft paper
a strong, high-quality paper, especially paper made from spruce fibers or cotton. ________ paper with an alkaline reserve is recommended when making preservation photocopies.
bond paper
Temperature and Relative Humidity recommended set points
65 degrees F +/- 5 degrees F (18C)
35-45 percent +/- 5 percent
A device for recording atmospheric humidity and temperature over time. Older models used pens to leave a trace on paper that a clockwork advanced. Modern instruments record the information in digital form to be downloaded to a computer for analysis and preservation.
hygrothermograph
An instrument used to measure relative humidity and to calculate dew point.
psychrometer
Air pollutants
sulphur dioxide
nitrogen dioxide
ozone
chemically unstable plastic that should never be used to house archival records
PVC=polyvinylchloride
emits HCl upon degradation
alum
aluminum sulphate
introduced as a replacement of potassium aluminum sulphate. Alum is acidic
small, usually reddish-brown spots appearing on paper; thought to be caused by the presence of trace metal (such as iron) in paper, as a by product of fungal growth
foxing
plain paper copy created by the xerox process intended to preserve the intellectual content of an unstable or damaged original document, a carbon black pigmented dry toner must be used with alkaline paper
preservation photocopy
term used to describe vinegary smell of acetic acid that is emitted as unstable cellulose acetate deteriorate. The effects of vinegar syndrome on film include brittleness and shrinking of the film, “channeling,” and related physical distortion as the emulsion and film separate.
vinegar syndrome
reducing digital file sizes that retains all original data
lossless compression
reducing file sizes that typically discards data
lossy compression
more commonly known as “backing up your data”. The process of making an exact duplicate of a digital object. NOT a long-term maintenance technique. Often combined with remote storage. Minimum maintenance strategy.
Bitstream copying
copy digital information from one long-term storage medium to another of the same type, with no change in the bitstream. Ex. decaying 4mm DAT to a new 4mm DAT tape.
Refreshing
may reduce the need for refreshing, and help diminish losses from media deterioration. Ex. gold CD
durable / persistent media
preserving the technical environment that runs the system, including the operating systems, original application software, media drives. Sometimes called the “computer museum” solution. More of a disaster recovery strategy. Ultimately a dead end since no obsolete technology can be kept functional indefinitely.
Technology Preservation
methods and procedures to rescue content from damaged media or from obsolete or damaged hardware and software. An emergency recovery strategy and usually involves specialized techniques to recover bitstreams from media that has been rendered unreadable. Generally carried out by for-profit companies.
Digital Archaeology
combines the conversion of digital objects into analog form with the use of durable analog media.
Analog backup
to copy data, or convert data, from one technology to another whether hardware or software, preserving the essential characteristics of the data. Broader and richer concept than refreshing. A set of organized tasks. Purpose is to preserve the integrity. some info is lost in migration.
migration
