Volatile aldehydes in libraries and archives

Volatile aldehydes are produced during degradation of paper-based materials. This may result in their accumulation in archival and library repositories. However, no systematic study has been performed so far. In the frame of this study, passive sampling was carried out at ten locations in four libraries and archives. Despite the very variable sampling locations, no major differences were found, although air-filtered repositories were found to have lower concentrations while a non-ventilated newspaper repository exhibited the highest concentrations of volatile aldehydes (formaldehyde, acetaldehyde, furfural and hexanal). Five employees in one institution were also provided with personal passive samplers to investigate employees’ exposure to volatile aldehydes. All values were lower than the presently valid exposure limits. The concentration of volatile aldehydes, acetic acid, and volatile organic compounds (VOCs) in general was also compared with that of outdoor-generated pollutants. It was evident that inside the repository and particularly inside archival boxes, the concentration of VOCs and acetic acid was much higher than the concentration of outdoor-generated pollutants, which are otherwise more routinely studied in connection with heritage materials. This indicates that further work on the pro-degradative effect of VOCs on heritage materials is necessary and that monitoring of VOCs in heritage institutions should become more widespread

Climate change mitigation strategies for mechanically controlled repositories: The case of The National Archives, Kew

A computer based building simulation model was developed to examine the energy load and environmental management in The National Archives Q1 repository building in Kew, UK to optimise environmental management and examine the impacts of climate change. The need to accurately simulate the hygrothermal environment inside the archive building which houses mainly paper-based records led to the choice of EnergyPlus as the modelling software. The study presents the simulation results of five environmental strategies which predict energy saving potential as high as 43% without significantly affecting the quality of the preservation environment. The effect of climate change is predicted to have little impact on the archive environment due to the filtering effect of the air conditioning system. On the other hand, an increase in total energy load by 15% and 24% is predicted under the worst case climate change scenario in 2050 and 2080, respectively, if the current environmental management practice is continued into the future. However, the identified energy saving strategies could represent possible mitigative solutions in reducing future energy load against the impact of climate change

Reduction of 4-ethylphenol concentration using lyophilized yeast biomasses as bioadsorbent: influence on the anthocyanin contents and chromatic parameters

A new investigation trend, based on the parietal adsorption activity showed by yeast cellwalls, opens up the possibility to use yeast lees or derived products like inactive dry yeast preparations to reduce 4-ethylphenol concentrations in wines. These type of natural products entails an interesting eco-friendly alternative to common physical treatments. In this work the bioadsorption capacity of 4-ethylphenol of different wine yeast biomasses have been studied -Saccharomyces cerevisiae G37 and Schizosaccharomyces pombe 936-, in order to diminish the negative impact on the sensorial profile of this type of compound (Figure 1). the repercussions of this palliative treatment over the chromatic properties and anthocyanin concentration have also been studied by means of UV-Vis and HPLC-PDAD/ESI-MS analysi

Damage Function for Historic Paper: Part II

Background As a result of use of library and archival documents, defined as reading with handling in the context of general access, mechanical degradation (wear and tear) accumulates. In contrast to chemical degradation of paper, the accumulation of wear and tear is less well studied. Previous work explored the threshold of mechanical degradation at which a paper document is no longer considered to be fit for the purpose of use by a reader, while in this paper we explore the rate of accumulation of such damage in the context of object handling. Results The degree of polymerisation (DP) of historic paper of European origin from mid-19th–mid-20th Century was shown to affect the rate of accumulation of wear and tear. While at DP > 800, this accumulation no longer depends on the number of handlings (the process is random), a wear-out function could be developed for documents with DP between 300 and 800. For objects with DP < 300, one large missing piece (i.e. such that contains text) developed on average with each instance of handling, which is why we propose this DP value as a threshold value for safe handling. Conclusions The developed model of accumulation of large missing pieces per number of handlings of a document depending on DP, enables us to calculate the time required for an object to become unfit for use by readers in the context of general access. In the context of the average frequency of document use at The UK National Archives (Kew), this period is 60 years for the category of papers with DP 300, and 450 years for papers with DP 500. At higher DP values, this period of time increases beyond the long-term planning horizon of 500 years, leading to the conclusion that for such papers, accumulation of wear and tear is not a significant collection management concern

Development of an electrochemical biosensor for the rapid detection of naphthalene acetic acid in fruits by using air stable lipid films with incorporated auxin-binding protein 1 receptor

This work describes the investigations of electrochemical interactions of naphthalene acetic acid (NAA) with stabilized lipid films supported on a methacrylate polymer on a glass fiber filter with incorporated auxin-binding protein 1 receptor for the development of a biosensor for the rapid detection of this compound in fruits. NAA was injected into the flowing streams of a carrier electrolyte solution, the flow of the electrolyte solution stops and an ion current transient was obtained; the magnitude of the signal was correlated to NAA concentration, which could be determined at the micromolar level. NAA preconcentrates at the lipid membrane surface which causes dynamic alterations of the electrostatic fields and phase structure of membranes. The response times were ca. 5 min and naphthalene acetic acid was determined at concentration levels of μM. The effect of potent interferences included a wide range of compounds. The results showed no interferences from these compounds in concentration levels usually found in real samples. The method was applied for the determination of NAA in fruits and the reproducibility of the method was checked in about 100 samples. A quantitative method for the detection of NAA in fruits that can be complimentary to HPLC methods is provided in the present paper. These lipid films can be used as portable sensors for the rapid detection of NAA in fruits by non-skilled personnel. © 2008 Bentham Science Publishers Ltd

LEO Satellites Constellation-to-Ground QKD Links: Greek Quantum Communication Infrastructure Paradigm

Quantum key distribution (QKD) has gained a lot of attention over the past few years, but the implementation of quantum security applications is still challenging to accomplish with the current technology. Towards a global-scale quantum-secured network, satellite communications seem to be a promising candidate to successfully support the quantum communication infrastructure (QCI) by delivering quantum keys to optical ground terminals. In this research, we examined the feasibility of satellite-to-ground QKD under daylight and nighttime conditions using the decoy-state BB84 QKD protocol. We evaluated its performance on a hypothetical constellation with 10 satellites in sun-synchronous Low Earth Orbit (LEO) that are assumed to communicate over a period of one year with three optical ground stations (OGSs) located in Greece. By taking into account the atmospheric effects of turbulence as well as the background solar radiance, we showed that positive normalized secure key rates (SKRs) up to 3.9×10−4 (bps/pulse) can be obtained, which implies that satellite-to-ground QKD can be feasible for various conditions, under realistic assumptions in an existing infrastructure