Longevity of Optical Disc Media: Accelerated Ageing Predictions and Natural Ageing Data

AbstractA considerable amount of uncertainty exists with respect to the lifetimes of optical disc media. In reports found in the literature, longevity for some discs is stated as less than five years, but for others, it can exceed one hundred years. The variability in the lifetime values has created a general distrust for optical discs as a reliable short or long-term storage option for information. This study was undertaken to provide some clarification about the uncertainty surrounding optical disc longevity. Using the European Computer Manufacturers Association standard ECMA-396, a recordable CD and a recordable DVD were subjected to a variety of elevated temperature and relative humidity conditions over several months. Eyring and Arrhenius predictive methods allowed longevity estimations to be made. It was found that the Arrhenius method produced realistic lifetime predictions for the recordable CD, but neither method produced reasonable figures for the recordable DVD. In addition, an analysis of naturally aged optical discs (up to seventeen years old) provided valuable data on disc lifetimes. This data also helped to validate the Arrhenius results for the recordable CD tested, but contradicted the long and unreasonable lifetime values predicted for the recordable DVD.

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Blu-Ray Media Stability and Suitability for Long-Term Storage

Restaurator International Journal for the Preservation of Library and Archival Material ◽

10.1515/res-2017-0016 ◽

2018 ◽

Vol 39 (2) ◽

pp. 129-155

Author(s):

Joe Iraci

Keyword(s):

Storage Capacity ◽

Error Rates ◽

Accelerated Ageing ◽

Initial Error ◽

Optical Disc ◽

Long Term Storage ◽

Attractive Option ◽

The Stability ◽

Term Storage

Abstract The most recent generation of optical disc media available is the Blu-ray format. Blu-rays offer significantly more storage capacity than compact discs (CDs) and digital versatile discs (DVDs) and thus are an attractive option for the storage of large image or audio and video files. However, uncertainty exists on the stability and longevity of Blu-ray discs and the literature does not contain much information on these topics. In this study, the stabilities of Blu-ray formats such as read-only movie discs as well as many different brands of recordable and erasable media were evaluated. Testing involved the exposure of samples to conditions of 80 °C and 85 % relative humidity for intervals up to 84 days. Overall, the stability of the Blu-ray formats was poor with many discs significantly degraded after only 21 days of accelerated ageing. In addition to large increases in error rates, many discs showed easily identifiable visible degradation in several different forms. In a comparison with other optical disc formats examined previously, Blu-ray stability ranked very low. Other data from the study indicated that recording Blu-ray media with low initial error rates is challenging for some brands at this time, which is a factor that ultimately affects longevity.

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Stability and viability of novel perennial ryegrass host–Neotyphodium endophyte associations

Crop and Pasture Science ◽

10.1071/cp12419 ◽

2013 ◽

Vol 64 (1) ◽

pp. 39 ◽

Cited By ~ 8

Author(s):

P. Tian ◽

T.-N. Le ◽

K. F. Smith ◽

J. W. Forster ◽

K. M. Guthridge ◽

...

Keyword(s):

Seed Storage ◽

Fungal Endophyte ◽

Accelerated Ageing ◽

Duration Of Treatment ◽

Pasture Grass ◽

Symbiotic Associations ◽

Long Term Storage ◽

Duration Of Storage ◽

Term Storage

The temperate pasture grass Lolium perenne L. is commonly found in association with the fungal endophyte Neotyphodium lolii. Viability of both seed and endophyte was evaluated by inoculation of individual genotypes from the host cultivar Bronsyn with six distinct endophyte strains. The resulting populations were subjected to either long-term storage under various temperature conditions, or accelerated ageing (AA) treatments. High temperature storage was detrimental to endophyte viability. The AA variables (relative humidity [RH] and time) and subsequent temperature and duration of storage significantly (P < 0.05) affected both seed germination and endophyte viability. Significant interaction effects between the AA treatment and storage conditions were also observed. Endophyte viability following AA treatment was inversely correlated with both increasing RH and duration of treatment. Differential responses between different endophytes within the Bronsyn host were also apparent. The standard endophyte (SE) strain and the novel endophytes AR1 and AR37 exhibited higher viability than NEA2, NEA3, and NEA6 during seed storage, suggesting the importance of identification and selection for compatible symbiotic associations in agronomic varieties. The observed similarity between assessments of endophyte viability after AA treatments and following long-term storage confirmed the capacity of moderate conditions (e.g. 80% RH for 7 days or 100% RH for 4 days) to predict variation in viability between different endophyte strains.

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Suitability of Flash Media for the Long-Term Storage of Information

Restaurator International Journal for the Preservation of Library and Archival Material ◽

10.1515/res-2019-0002 ◽

2019 ◽

Vol 40 (2) ◽

pp. 97-122

Author(s):

Joe Iraci

Keyword(s):

High Capacity ◽

Accelerated Ageing ◽

Flash Storage ◽

Long Term Stability ◽

Long Term Storage ◽

Storage Media ◽

The Stability ◽

To Receive ◽

Term Storage

Abstract Flash storage media such as memory cards and USB flash drives are now commonly used to transfer and store information. However, little is known about the long-term stability of this type of media and this is a concern for archives and other institutions as they begin to receive content stored on these devices. In this study, the stabilities of a variety of different flash media were examined. The evaluation was performed by using accelerated ageing at 85 °C and 85 % relative humidity (RH) and 125 °C for ageing intervals up to 2000 hours. Measurements were also performed on samples previously subjected to accelerated ageing and then naturally aged for five years to verify the results from the accelerated ageing experiments. Overall, the stability of flash media was very good. For many of the samples, no read errors were encountered after accelerated or natural ageing. However, for several of the high capacity flash card samples and USB flash drives, significant decreases in read speed were noted. This can be problematic because it will eventually lead to read errors. It was established that for the USB samples this instability was likely attributed to the use of the less stable TLC (triple-level cell) memory chip.

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Modelling of Moisture Movement in Wood during Outdoor Storage

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2001.6.1.15210 ◽

2001 ◽

Vol 6 (2) ◽

pp. 3-14 ◽

Cited By ~ 23

Author(s):

R. Baronas ◽

F. Ivanauskas ◽

I. Juodeikienė ◽

A. Kajalavičius

Keyword(s):

Experimental Data ◽

Finite Difference ◽

Climatic Conditions ◽

Two Dimensional ◽

Moisture Movement ◽

Finite Difference Technique ◽

Long Term Storage ◽

Space Formulation ◽

Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

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