Preservação sistêmica para repositórios arquivísticos / Systemic preservation for archival repositories / Preservación sistémica para repositorios de archivo

Este estudo realiza uma reflexão sobre a preservação de documentos arquivísticos digitais em uma perspectiva sistêmica, pautada em padrões reconhecidos pela literatura científica. De tal forma, utiliza-se da visão holística para ressaltar a pertinência da preservação ser pensada em todo o ciclo de vida dos documentos. A metodologia parte do levantamento bibliográfico composto por artigos, livros e publicações técnicas, para assim, obter uma revisão narrativa. Ressalta-se que a preservação digital tem evoluído para novos patamares e requer o uso de padrões para implementar sistemas informatizados confiáveis. Com isso, pode-se envolver todo o ciclo vital em uma cadeia de custódia ininterrupta capaz de assegurar a autenticidade dos documentos digitais. Por fim, defende-se uma abordagem sistêmico-holística, em que os documentos são planejados e produzidos tendo em vista a preservação e o acesso em longo prazo.

This study reflects on the preservation of digital archival records from a systemic perspective, based on standards recognized by scientific literature. In such a way, it uses a holistic view to emphasize the relevance of preservation to be considered throughout the life cycle of records. The methodology is based on a bibliographic survey composed of articles, books, and technical publications, to obtain a narrative review. It is noteworthy that digital preservation has evolved to new heights, and requires the use of standards to implement reliable computer systems. With this, the entire life cycle can be involved in an uninterrupted chain of custody capable of ensuring the authenticity of digital records. Finally, a systemic-holistic approach is advocated, in which records are planned and produced with a view of the preservation and access in the long-term.

Este estudio reflexiona sobre la preservación de los documentos de archivo digital en una perspectiva sistémica, basada en normas y estándares reconocidos por la literatura científica. De esta manera, utiliza la visión holística para enfatizar la relevancia de la preservación a ser considerada a lo largo del ciclo de vida de los documentos. La metodología se basa en una encuesta bibliográfica compuesta de artículos, libros y publicaciones técnicas, para obtener una revisión narrativa. Es de destacar que la preservación digital ha evolucionado a nuevas alturas y requiere el uso de estándares para implementar sistemas informáticos confiables. Con esto, todo el ciclo de vida puede involucrarse en una cadena de custodia ininterrumpida capaz de garantizar la autenticidad de los documentos digitales. Finalmente, se aboga por un enfoque holístico-sistémico, en que los documentos se planifican y producen con miras la preservación y acceso a largo plazo.

Blemish Formation in Processed Microfilm II.

Gaseous peroxides form blemishes on some processed microfilms. Two procedures are given for testing the blemish susceptibility of processed microfilm, one using peroxide paper and the other zinc powder as a source of peroxide. The susceptibility of microfilm to blemish formation decreased when conditioned at 86 percent relative humidity and 26 °C. Coarse-grain microfilms are less susceptible to blemish formation than fine-grain microfilm. Fine-grain microfilms fixed in ammonium thiosulfate were less susceptible to blemish formation than those fixed in sodium thiosulfate. Oven-aged microfilm storage cartons were found to generate peroxide when wetted. The microfilm base readily absorbed hydrogen peroxide.

Blemish Formation in Processed Microfilm.

Oxidizing and reducing agents generated by paper cartons during storage may react with the image silver to form. The type of fixing bath, concentration of chlorine in the wash water, washing time and composition of the storage cartons can be factors that accelerate or retard the attack of the peroxide on the image silver. Microfilm washed after fixation in distilled water or chlorine-free tap water formed blemishes when exposed to peroxide paper. A trace of silver chloride in the image silver of processed microfilm augmented the formation of the natural type blemishes when exposed to peroxide paper, but high concentrations of residual silver chloride inhibited blemish formation. During storage, some storage cartons evolved formaldehyde, formic acid, and ammonia which created a chemical environment favorable for blemish formation in microfilm in the presence of peroxide. A correlation was found between the incidence of blemishes and the brand of paper storage cartons. A procedure was developed for testing processed microfilm to determine its susceptibility to blemish formation. According to the present theory, peroxide reacts with the silver in the image, forming colloidal silver which imparts a yellowish or reddish color to the blemishes.