| 1. |
- Nyström, Ingalill, 1969
(författare)
-
Bonadsmåleri under lupp: Spektroskopiska analyser av färg och teknik i sydsvenska bonadsmålningar 1700-1870
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objects of this PhD thesis are Southern Swedish painted wall-hangings: folk art paintings from the 18th and 19th centuries. The aim and objective of the study are: to investigate the construction and manufacturing processes of the painted wall-hangings; to identify both the painting materials and other substances employed; and, to document painting techniques used by different painters within this painted wall-hanging tradition. This is to get an increased understanding of the materials and techniques used, and the material development of these painted objects during the 18th and 19th centuries. The study is interdisciplinary in which Art Technological Source Research (ATSR) is combined with conservation science. Non-destructive and non-invasive analytical methods were preferentially used. Therefore spectroscopic methods including multi-spectral imaging systems, FT-Raman with a micro video probe head, FTIR with diffuse reflectance and Electron Microscopy with Elemental Analysis (SEM-EDX) were applied. Most of these chemical and technical analyses are undertaken on site. Supplementing analyses using spot tests and experimental reconstructions of coloring matters from plants and possible binder composition has then been carried out in the laboratory. In order to understand the manufacturing process of the wall-hangings also mock-ups where made. Historical recipes have been used to make these reconstructions. The Results indicate that generally inexpensive pigments such as chalk, red lead, ochres, orpiment, carbon black and woad have been used. Some artificial pigments such as; Prussian blue, emerald green and chrome yellow were introduced in the wall-hangings in the latter part of the era. The binding media in the paint contains egg and in some cases also starch. The paint is normally painted on reused linen cloth prepared with starch containing glue. During 19th century also paper has been used as a support. Representative for these painted objects is also that templates were adopted for the figures in the picture scenes and motifs. The significance of this study is that the materials science and knowledge of the technology used is important to be able to predict degradation risks, and to develop preventive and remedial conservation strategies for these objects. The technological material knowledge not only is crucial for preservation but also can supplement previous studies and previous attribution of Southern Swedish painted wall-hangings without signature.
|
|
| 2. |
- Nyström, Ingalill, 1969
(författare)
-
Materials in folk art from Hälsingland – A colourful study.
- 2016
-
Ingår i: Book of abstracts. Materials for Tomorrow: Chalmers annual Materials Science Initiative Seminar and the Division of surface and materials chemistry annual symposium. Nov 8-10, 2016, Gothenburg, Sweden.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- What can we learn from the materials of yesterday for the materials of tomorrow? This talk is about art technology and the materials found in folk arts and crafts in decorated farmhouses of Hälsingland, UNESCO World Heritage since 2012. A variety of case studies from the project called “Decorated Farmhouses of Hälsingland: a holistic study of a world heritage site” will be presented. Wall paintings and painted furniture as well as decorated textiles are examined to understand their technology and artist’s materials. The study is cross disciplinary and methods from natural and historical sciences have been applied. The project is funded by the Swedish Research Council (VR), started in January 2014, and extends over four years. It is a collaboration between different researchers: conservation scientists, chemists, physicists, conservators, art historians and ethnologists from University of Gothenburg, Chalmers University of Technology, Linköping University and the Swedish National Heritage Board. The scientific analyses applied in the study are primarily different spectroscopic methods. Non-invasive analyses using multispectral imaging and XRF were conducted directly on art objects in museums and homestead museums. Additionally, samples were taken from these objects for supplementary analyses using FT-Raman and IR spectroscopy and DSA-ToF-MS and GC-MS. As a conclusion from this study, we believe that cooperation between different disciplines is crucial to tackle and interpret empirical material that often contains both historical sources that require transcriptions and interpretations, and material characterization and scientific interpretation of the analytical results. When different skills and various perspectives come together, new interpretations and new knowledge can be obtained. And in a sustainable perspective, the craft techniques and materials, as well as the historic recipes revealed in our study, have the potential to be re-used in the development of modern paints for the buildings of tomorrow.
|
|
| 3. |
- Oudbashi, Omid, 1978, et al.
(författare)
-
Lead isotope analysis of Bronze Age copper alloy objects from Deh Dumen graveyard, southwestern Iran
- 2023
-
Ingår i: Archaeological and Anthropological Sciences. - : Springer Science and Business Media LLC. - 1866-9557 .- 1866-9565. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- This research presents the lead isotopic composition of ten objects made of copper-tin alloy or arsenical copper that was recovered at the Bronze Age cemetery at Deh Dumen (southwestern Iran). Grave goods associated with different cultures in eastern Iran, Susa, or Luristan were identified at the site, and lead isotopic analyses were conducted to identify the copper sources used for the production of copper alloy objects found in multiple tombs. Comparison with data for ore sources shows that some of the objects have a signature that is compatible with that of the Iranian sources located in the Urumieh-Dokhtar and the Sanandaj-Sirjan. It also shows that three objects are compatible with the signature of objects found in the Gujarat and ore sources in the Aravalli-Delhi Belt deposits (Rajasthan and Gujarat) in India, demonstrating long-distance exchange between southwestern Iran and the Indus valley.
|
|
| 4. |
- Hajjari, Elaheh, et al.
(författare)
-
Technical studies on the mechanisms of corrosion and state of conservation of two hoards of Persian copper coins (folus) from the Safavid period in Iran
- 2021
-
Ingår i: Journal of the Institute of Conservation. - : Informa UK Limited. - 1945-5224 .- 1945-5232. ; 44, s. 86-98
-
Tidskriftsartikel (refereegranskat)abstract
- A series of corroded Safavid copper coins (folus) dating to the seventeenth century CE and minted in Isfahan were discovered in Hamedan, Western Iran. A selection of these coins was studied to identify the minting process, corrosion morphology and mechanisms, and their state of conservation. Eight coins from two hoards were analysed using metallography, ICP–OES, SEM–EDS and XRD to identify their metal/alloy compositions and microstructures, as well as the chemical compositions of any corrosion layers and products. The results showed that the coins were minted from blanks using thermo-mechanical processing to produce their relief-like surfaces. The corrosion morphology was found to include a two-layered corrosion crust in which the original surface was well-retained, and the corrosion mechanisms identified were internal dissolution and oxidation of copper and the formation of copper (II) compounds over the original surface. The presence of chloride compounds in the corrosion products showed that the coins have been suffering from ‘bronze disease’ so that any preventive conservation must include keeping the relative humidity of their storage and exhibition environments below 45%.
|
|
| 5. |
- Holakooei, Parviz, et al.
(författare)
-
On, under and beneath the patina: Evaluation of micro energy dispersive X-ray fluorescence quantitative data on the classification of archaeological copper alloys
- 2021
-
Ingår i: Spectrochimica Acta - Part B Atomic Spectroscopy. - : Elsevier BV. - 0584-8547. ; 178
-
Tidskriftsartikel (refereegranskat)abstract
- A series of quantitative micro X-ray fluorescence (μ-XRF) analyses was performed on a) corroded surface, b) stripped-patina area and c) polished cross section of twenty-five archaeological copper alloys from Iran in order to check the viability of quantitative XRF data for the classification of ancient copper alloys. The limits of detection and quantification and, also, the precision and accuracy of the analytical data were measured using twelve certified reference materials (CRM). The compositional data obtained through these three approaches were statistically evaluated comparing with the compositional data on the same samples obtained by the inductively coupled plasma – optical emission spectroscopy (ICP-OES). We demonstrated that the corroded surfaces are depleted in Ni and Zn and enriched in Pb, Sn and As. Also, we suggest that although μ-XRF quantitative compositional data collected from the corroded surfaces may result in misleading information, the areas with the lowest Sn concentration may represent the closest compositional data to the absolute quantity of Cu, Zn, As and Pb in ancient copper alloys. Moreover, it is shown that the quantitative μ-XRF data obtained from the stripped-patina surface and those from the polished cross sections are comparable with the ICP-OES compositional data and can be confidently used for determining the diversity and technology of ancient copper alloys.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Pedersen, Nanna Bjerregaard, et al.
(författare)
-
Correlation between bacterial decay and chemical changes in waterlogged archaeological wood analysed by light microscopy and Py-GC/MS
- 2021
-
Ingår i: Holzforschung. - : Walter de Gruyter GmbH. - 0018-3830 .- 1437-434X. ; 75:7, s. 635-45
-
Tidskriftsartikel (refereegranskat)abstract
- © 2020 Nanna Bjerregaard Pedersen et al., published by De Gruyter, Berlin/Boston 2020. Erosion bacteria are the main degraders of archaeological wood excavated from waterlogged environments. Light microscopy and analytical pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) were exploited to study waterlogged archaeological wood (Pinus sylvestris L.) at different stages of bacterial decay. The research explored the biochemical changes related to erosion bacteria degradation of the secondary cell wall in the wood cells and the chemical changes related to abiotic processes induced by the long-term waterlogged burial environment. Erosion bacteria were demonstrated by chemical analysis to cause significant holocellulose depletion. Detailed analysis of the holocellulose and lignin pyrolysis products revealed only minor chemical changes in the residual structure even after heavy erosion bacteria decay. Chemical changes in the lignin polymer is associated to enzymatic unlocking of the lignocellulose to gain access to the holocellulose fraction of the cell wall. Chemical changes in the holocellulose fraction are suggested to stem from depolymerisation and from alterations in the polymer matrix of the residual wood cell wall structure. Interestingly, a difference was observed between the sound reference wood and the waterlogged archaeological wood without erosion bacteria decay, indicating that long-term exposure in waterlogged environments results in partial decay of the holocellulose even in absence of bacterial activity.
|
|
| 9. |
|
|
| 10. |
- Henrik-Klemens, Åke, et al.
(författare)
-
Raman Spectroscopic Investigation of Iron-Tannin Precipitates in Waterlogged Archaeological Oak
- 2022
-
Ingår i: Studies in Conservation. - : Informa UK Limited. - 0039-3630 .- 2047-0584. ; 67, s. 237-247
-
Tidskriftsartikel (refereegranskat)abstract
- As the redox catalytic activity of iron may be detrimental for waterlogged archaeological wood, it is of importance to know what ligands bind the iron, their distribution in the wood, and what the reactivity of these compounds are. We have identified iron-tannin precipitates in archaeological oak timber from the shipwreck of the seventeenth-century warship The Sword with confocal Raman spectroscopy in combination with light- and scanning electron microscopy. Iron tannin precipitates are present as larger aggregates (10–50µm) in the lumen and vessels, but also as contamination within the wood cell wall. As the stability constants of iron-tannin and iron-diethylenetriamine-pentaacetic acid (DTPA) – a chelating agent commonly employed by conservators to extract iron – are in the same range, extraction experiments were carried out. These demonstrate that iron-tannin precipitations are difficult to extract. Tannin chemistry in waterlogged oak needs to be further explored to understand the mechanism of iron accumulation in wood as well as to correctly treat and preserve cultural heritage.
|
|
