Ira Rabin

The surface plasmon resonance of free and embedded Ag-clusters in the size range 1,5 nm D 30 nm

It is experimentally proven that the size dependence of the surface plasmon resonance of large spherical silver clusters is related to the surface optical properties of Ag. It is also demonstrated that there is a minimum size, below hich this approach fails as expected, and that there is a maximum size, above which the surface contribution can be neglected such that classical optics applies.

3D Micro-XRF for Cultural Heritage Objects: New Analysis Strategies for the Investigation of the Dead Sea Scrolls

A combination of 3D micro X-ray fluorescence spectroscopy (3D micro-XRF) and micro-XRF was utilized for the investigation of a small collection of highly heterogeneous, partly degraded Dead Sea Scroll parchment samples from known excavation sites. The quantitative combination of the two techniques proves to be suitable for the identification of reliable marker elements which may be used for classification and provenance studies. With 3D micro-XRF, the three-dimensional nature, i.e. the depth-resolved elemental composition as well as density variations, of the samples was investigated and bromine could be identified as a suitable marker element. It is shown through a comparison of quantitative and semiquantitative values for the bromine content derived using both techniques that, for elements which are homogeneously distributed in the sample matrix, quantification with micro-XRF using a one-layer model is feasible. Thus, the possibility for routine provenance studies using portable micro-XRF instrumentation on a vast amount of samples, even on site, is obtained through this work.

On the origin of the ink of the Thanksgiving scroll (1QHodayota)

In this study we demonstrate the possibility to identify the production area of the scrolls, coupling non-destructive quantitative analysis of trace elements to spectroscopic investigation of the inks. This approach, that allowed us to determine the Dead Sea area as origin of 1QHodayot a , is of general validity.

Dead Sea Scrolls Exhibitions around the World: Reasons for Concern

The Dead Sea Scrolls that miraculously survived for over two thousand years suffered considerable damage due to various post-discovery interventions. Today they are subjected to frequent travelling exhibitions. The current work collates the published information on exhibitions and conservational treatments with the results of the analytic studies of the skin-based material of the scrolls conducted since their discovery. The examination of the properties of the scrolls proves that frequent travel, exhibitions and the associated handling induce collagen deterioration that is covered up by the absence of a proper monitoring program. Zusammenfassung/résumé at end of article received: 05.10.2011 revised: 20.02.2012 101 DOI: 10.1515/res-2012-0005 Their miraculous survival for over two thousand years in the darkness of the dry caves of the Judean Desert and their historical importance require us to ensure their long-term preservation. Our duty toward the DSS goes beyond textual studies and interpretations and requires us to save them for future generations and subsequent studies with as yet unknown technologies. The question of their long-term preservation is not an easy one because the scrolls are made of organic materials prone to rapid degradation. The deterioration processes were slowed down by the conditions in the caves but regained a dangerous impetus in the first decade after the discovery. In fact, the post-discovery history of the scrolls is a well-known saga of continuous mishandling (Caldararo 1995, Boyd-Alkalay and Libman 2000). In short, excessive humidity, castor oil and glycerol, adhesive tape and glass plates, mounting of the fragments on a lens paper with local application of the PVA adhesive or reinforcement with 3–5% PMMA (Perspex) in trichloroethylene are listed among the most common treatments of the first 30 years. During the last 20 years, practically all the conservation work on the scrolls in Israel was entrusted to the special DSS conservation laboratory established in 1991. New treatment procedures included removal of the adhesive residues by direct application of Fullers earth with organic solvents such as methyl ethyl ketone (MEK) or acetone and reinforcement (temporary on recto, and permanent on verso) with Japanese paper coated with water-soluble adhesive such as methyl cellulose. In the next section we discuss an example of such a treatment. An interested reader will find further information in the detailed review published by the laboratory (Boyd-Alkalay and Libman 2000). Each treatment, even more when added to a previous one, transformed the fragile ancient parchment into a conglomerate of materials with unpredictable response to environmental changes. The original scroll fragment thereby lost its ability to respond to environmental changes by shrinking or expanding. Underrating the significance of the material aspects leads to an oversimplified approach to the scrolls’ preservation. When a cursory inspection reveals no new defects, the preservation policy is declared adequate. In the absence of thorough inspection, frequent travel to exhibitions presents a dangerous assault on the safety and long-term preservation of the scrolls. Exhibitions have without doubt educational and cultural significance. Physical objects from the “time of Christ” make this significant part of antiquity tangible and transform an abstraction into a reality show. Hence, the DSS on exhibit attract large audiences, allowing the organizers and owners to benefit greatly. However, we should also consider the effect of the travelling exhibitions on the scrolls themselves. Are we sure that the laconic statement “no change” on a condition report describes the actual situation adequately? Dead Sea Scrolls Exhibitions around the World

The influence of CO on the surface plasmon absorption band of small silver clusters (D≤20 Å)

The surface plasmon absorption band of small Ag particles (diameter≤100 Å) in the gasphase as well as for clusters embedded in noble gas matrices is known to shift to higher energies and to broaden with decreasing diameter. This size effect depends sensitively on the microscopic surface properties of the clusters, which can be influenced by the interaction with the embedding matrix. Previous experiments with silver clusters in the size range 20 Å≤D≤100 Å proved that for SiO2 and CO the matrix influence is strong enough to supersede the intrinsic size effect as observed in the noble gas matrices. The investigation of the influence of a CO matrix on smaller clusters with D≤20 Å reveals a novel feature: the position as well as the width of the surface plasmon absorption band become independent of the cluster size.

Nine Dubious “Dead Sea Scrolls” Fragments from the Twenty-First Century

In 2002 new “Dead Sea Scrolls” fragments began to appear on the antiquities market, most of them through the Kando family. In this article we will present evidence that nine of these Dead Sea Scrolls-like fragments are modern forgeries.

Composition of the primary inks in medieval palimpsests – effects of ink removal

The qualitative and quantitative investigations of historical iron-gall inks by use of μ-XRF spectrometry is a common method for analyzing the diff erences in their composition. When a fingerprint is established, it is possible to characterize the distinguishable inks used in the production of medieval manuscripts, and, in turn assist in the reconstruction of the manuscript’s history.The characterization of the primary inks in palimpsests, i.e. manuscripts written on re-used parchment, presents a serious problem as the effect of the partial removal on the inks fi ngerprint is yet known. In this paper we explore our preliminary results concerning the effects of two removal techniques on the fingerprint of iron-gall inks on parchment.