18 research outputs found
Effects of conservation interventions on the archaeological Roman site of Merida (Spain). Advance of research.
Research on the assessment of the effects of conservation/restoration treatments on stone material has been significant in recent years, with focus on the early observation of decay caused by the application of these treatments. However, in the case of archaeological sites, research is still scarce and few studies on the subject have been published. Restoration, as everything else, has changed according to trends, mainly guided by the release of new products and technologies, an experimental field where scientific assessment of suitability, efficacy and durability pre-evaluations of treatments are not always conducted. Some efforts have been made to solve this problem in the architectural field, where functional needs and technical requirements force to set clear standards. Unfortunately, archaeological sites, unlike historic buildings, have specific features that preclude the extrapolation of these results. A critical review of the methodologies, products and restoration materials is necessary, coupled with deeper research on degradation mechanisms caused by these treatments in the mid- and long-term. The aim of this paper is to introduce the research on the above issues using Merida as a case study
Integrated Studies for the Evaluation of Conservation Treatments on Stone Material from Archaeological Sites. Application to the Case of Merida (Spain)
The application of conservation treatments, such as consolidation and protection ones, has been demonstrated ineffective in many cases, and even harmful. Evaluation studies should be a mandatory task, ideally before and after the intervention, but both tasks are complex and unusual in the case of archaeological heritage. This study is mainly focused on analyzing changes in petrophysical properties of stone material from archaeological sites of Merida (Spain), evaluating, both on site and in laboratory, effects derived from different conservation treatments applied in past interventions, throughout the integration of different non-destructive techniques (NDT) and portable devices of analysis available at the Institute of Geosciences (CSIC,UCM). These techniques allow, not only assessment of effectiveness and alteration processes, but also monitoring durability of treatments, focused mainly on 1996 intervention in the case of Roman Theater, as well as different punctual interventions from the 90’s until date in the House of Mitreo. Studies carried out on archaeological sites of Merida permit us to compare outcomes and also check limitations in the use of those equipments. In this paper we discuss about the use of some techniques, their integration and limits, for the assessment of conservation treatments, showing some examples of Merida’s case study
Integrated studies for the evaluation of conservation treatments on buildings materials from archaeological sites: application to the case of Merida (Spain)
The application of conservation treatments, such as consolidation and protection ones, has been demonstrated ineffective in many cases, and even harmful. Evaluation studies should be a mandatory task, ideally before and after the intervention, but both tasks are complex and unusual in the case of archaeological heritage. This study is mainly focused on analyzing changes in petrophysical properties of stone material from archaeological sites of Merida (Spain), evaluating, both on site and in laboratory, effects derived from different conservation treatments applied in past interventions, throughout the integration of different non-destructive techniques (NDT) and portable devices of analysis available at the Institute of Geosciences (CSIC,UCM). These techniques allow, not only assessment of effectiveness and alteration processes, but also monitoring durability of treatments, focused mainly on 1996 intervention in the case of Roman Theater, as well as different punctual interventions from the 90?s until date in the House of Mitreo. Studies carried out on archaeological sites of Merida permit us to compare outcomes and also check limitations in the use of those equipments. In this paper we discuss about the use of some techniques, their integration and limits, for the assessment of conservation treatments, showing some examples of Merida?s case study
Adverse effects arising from conservation treatments on archaeological sites: theory, practice and review
Conservation and restoration of archaeological
sites developed significantly in the second half of
the twentieth century, with greater emphasis in
recent decades, which has led to a considerable
number of interventions.
Methodology of intervention has changed
significantly since more interventionist measures
are performed against the current criteria of
minimum intervention, although what actually
occurs today is a difficult balance between
innovation (experimental application of new
techniques and products) and minimum
intervention. The debate, in the case of
archaeological sites, has focused on the actions
traditionally more aggressive: cleaning,
consolidation or reintegration, as this is where
most notable has been the restorative action
throughout history.
The restoration, like everything else, has been
subject of trends, in relation to the appearance
of new products and technologies, and today
remains a discipline that widely develops
experimental practice. It certainly brings great
benefits and constant renewal of criteria and
methodologies, but also risks by introducing new
compounds that may interact negatively with
original substrate, although their effects cannot
be checked in the short or medium term. The
lack of knowledge of the causes of decay arising
from previous interventions has generated a series of continuous protection and
consolidation treatments at different periods.
Restorers currently must deal with decayed areas
where the products, methodology or techniques
used, have caused a negative effect on the
original material. This paper attempts to explore
the general study of effects and alterations
arising from restoration treatments, as well as
reviewing of scientific publications related to this
issue.series of continuous protection and
consolidation treatments at different periods.
Restorers currently must deal with decayed areas
where the products, methodology or techniques
used, have caused a negative effect on the
original material. This paper attempts to explore
the general study of effects and alterations
arising from restoration treatments, as well as
reviewing of scientific publications related to this
issue.This research was supported by the PICATA
fellowship program from Campus of
International Excellence of Moncloa. Our
acknowledgements to GEOMATERIALES
programme (S2009-MAT1629/GEOMATERIALES) within Instituto de
Geociencias (CSIC, UCM), to AIPA programme
(ETSAM, Polytechnic University of Madrid) and to
the Research Group financed by the
Complutense University of Madrid "Alteration
and Conservation of heritage stone materials”
(ref. 921349).Peer reviewe
Effects of conservation interventions on the archaeological Roman site of Merida (Spain). Advance of research
Research on the assessment of the effects of conservation/restoration treatments on stone material has been significant in recent years, with focus on the early observation of decay caused by the application of these treatments. However, in the case of archaeological sites, research is still scarce and few studies on the subject have been published. Restoration, as everything else, has changed according to trends, mainly guided by the release of new products and technologies, an experimental field where scientific assessment of suitability, efficacy and durability pre-evaluations of treatments are not always conducted. Some efforts have been made to solve this problem in the architectural field, where functional needs and technical requirements force to set clear standards. Unfortunately, archaeological sites, unlike historic buildings, have specific features that preclude the extrapolation of these results. A critical review of the methodologies, products and restoration materials is necessary, coupled with deeper research on degradation mechanisms caused by these treatments in the mid- and long-term. The aim of this paper is to introduce the research on the above issues using Merida as a case study.Peer Reviewe
Effects of Conservation Interventions on the Archaeological Roman Site of Merida (Spain). Advance of Research
Efectos derivados de tratamientos de conservación y restauración sobre material inorgánico en yacimientos arqueológicos. Caso de estudio: Mérida
NDT for the detection and characterization of superficial treatments on stone material from archaeological sites of Merida (Spain)
Different treatments (consolidation and water-repellent) were applied on samples of marble and granite from the Front stage of the Roman Theatre of Merida (Spain). The main goal is to study the effects of these treatments on archaeological stone material, by analyzing the surface changes. X-Ray Fluorescence and Laser-Induced Breakdown Spectroscopy techniques, as well as Nuclear Magnetic Resonance have been used in order to study changes in the surface properties of the material, comparing treated and untreated specimens. The results confirm that silicon (Si) marker tracking allows the detection of applied treatments, increasing the peak signal in treated specimens. Furthermore, it is also possible to prove changes both within the pore system of the materialand in the distribution of surface water, resulting from the application of these product
Proceedings of the international course Ceramic materials in building heritage: conservation problems and intervention
Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu
Changes in Petrophysical Properties of the Stone Surface due to Past Conservation Treatments in Archaeological Sites of Merida (Spain)
Petrophysical properties, such as porosity, permeability, density or anisotropy de-termine the alterability of stone surfaces from archaeological sites, and therefore, the future preservation of the material. Others, like superficial roughness or color, may point out changes due to alteration processes, natural or man-induced, for ex-ample, by conservation treatments.
The application of conservation treatments may vary some of these properties forcing the stone surface to a re-adaptation to the new conditions, which could generate new processes of deterioration. In this study changes resulting from the application of consolidating and hydrophobic treatments on stone materials from the Roman Theatre (marble and granite) and the Mitreo’s House (mural painting and mosaics), both archaeological sites from Merida (Spain), are analyzed. The use of portable field devices allows us to perform analyses both on site and in la-boratory, comparing treated and untreated samples. Treatments consisted of syn-thetic resins, consolidating (such as tetraethoxysilane TEOS) and hydrophobic products. Results confirm that undesirable changes may occur, with consequences ranging from purely aesthetic variations to physical, chemical and mechanical damages. This also permits us to check limitations in the use of these techniques for the evaluation of conservation treatments
Development of nanobodies against hemorrhagic and myotoxic components of Bothrops atrox snake venom
Snake envenoming is a globally neglected public health problem. Antivenoms produced using animal hyperimmune plasma remain the standard therapy for snakebites. Although effective against systemic effects, conventional antivenoms have limited efficacy against local tissue damage. In addition, potential hypersensitivity reactions, high costs for animal maintenance, and difficulties in obtaining batch-to-batch homogeneity are some of the factors that have motivated the search for innovative and improved therapeutic products against such envenoming. In this study, we have developed a set of nanobodies (recombinant single-domain antigen-binding fragments from camelid heavy chain-only antibodies) against Bothrops atrox snake venom hemorrhagic and myotoxic components. An immune library was constructed after immunizing a Lama glama with whole venom of B. atrox, from which nanobodies were selected by phage display using partially purified hemorrhagic and myotoxic proteins. Biopanning selections retrieved 18 and eight different nanobodies against the hemorrhagic and the myotoxic proteins, respectively. In vivo assays in mice showed that five nanobodies inhibited the hemorrhagic activity of the proteins; three neutralized the hemorrhagic activity of whole B. atrox venom, while four nanobodies inhibited the myotoxic protein. A mixture of the anti-hemorrhagic and anti-myotoxic nanobodies neutralized the local tissue hemorrhage and myonecrosis induced by the whole venom, although the nanobody mixture failed to prevent the venom lethality. Nevertheless, our results demonstrate the efficacy and usefulness of these nanobodies to neutralize important pathologies of the venom, highlighting their potential as innovative therapeutic agents against envenoming by B. atrox, a viperid species causing many casualties in South America.National Council of Science and Technology/[188-2015-FONDECYT]/CONCYTEC-FONDECYT/PerúUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP