Central institute for conservation

Belgrade, Serbia

Central institute for conservation

Belgrade, Serbia
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Radojkovic B.,Institut Gosa | Ristic S.,Institut Gosa | Polic S.,Central Institute for Conservation
Lasers in Engineering | Year: 2017

The main aim of this paper is to present the results of the morphological and chemical changes on the surface of a ceramic sample irradiated by the Nd:YAG laser. The tested sample is a part of an aqueduct tile, originating from the archaeological site of Yazd, Iran. The laser irradiation effects were studied as a function of the number of laser pulses and laser fluences around and over the damage threshold. The obtained modifications were investigated because these are essential in laser cleaning of aqueduct ceramics. The Nd:YAG laser with a wavelength, γ, of 1064 nm and full width at half maximum (FWHM) pulse, τ, of 150 ps has been used for the surface treatment. The ceramic surface morphology modifications, induced by laser, were characterized by a scanning electron microscope (SEM), while the composition was examined by energy-dispersive (EDX) and X-ray fluorescence (XRF) spectroscopy. The results show that there are significant differences depending on the applied laser fluences and whether the surface is glazed or not. © 2017 Old City Publishing, Inc.

Kozic M.S.,Military Technical Institute Belgrade | Ristic S.S.,Institut Gosa | Stetic Kozic S.M.,University of Belgrade | Polic S.R.,Central Institute for Conservation
Thermal Science | Year: 2015

The level of pollution concentration to the archeological site Viminacium caused by the stack of Kostolac B power plant is analysed using CFD software. The wind is directed from the stack toward Viminacium-Archeological Site, Therma and Viminacium-Museum. Three different meteorological conditions resulting in fanning, fumigating, and looping plume are modelled. The temperature gradient as the most important factor defining the conditions of the atmosphere is included through the appropriate boundary conditions. It is shown that concentrations of the pollutants on the objects of Viminacium are very low. It can be attributed to the stack height and high temperature of the smoke at its exit. It also indicates that other sources of pollution such as open ash dumps and acid rain should be checked.

Ristic S.,Institut Gosa | Polic-Radovanovic S.,Central Institute for Conservation | Katavic B.,Institut Gosa | Nikolic Z.,Institut Gosa | And 2 more authors.
Lasers in Engineering | Year: 2012

This paper presents some results of laser beam interaction (ruby laser, Q-switch) with the contaminated surface of the Neolithic ceramics from Stubline in Serbia, which had been exposed to atmospheric and other conditions. The main aim was to determine a threshold of laser light energy density applied in cleaning and to test if the ruby laser with nominal energy of 1J can be applied simultaneously for cleaning of encrustations on the ceramic surface, and non-destructive tests of the cleaning process by holographic interferometry. The first step was to determine a threshold of the laser energy density applied in cleaning. The effects of the laser beam interaction were examined by scanning electron microscope (SEM) equipped with energy-dispersion spectroscope (EDS). © 2012 Old City Publishing, Inc.

Todorovic M.S.,University of Belgrade | Todorovic M.S.,Kyung Hee University | Todorovic M.S.,University of South China | Ecim-Crossed D Signuric O.,University of Belgrade | And 3 more authors.
Energy and Buildings | Year: 2015

This paper recognizes the synergetic relationship and inextricable linkage between conservation and sustainability. Heritage preservation maximizes the use of existing materials and infrastructure, reduces waste, and preserves the historic character of older towns and cities. This paper also presents technical advances in BPS/BES (Building Performance Simulation/Building Energy Simulation), and in co-simulation for energy efficiency optimization, RES integrated historic building's greening and historic neighborhoods, settlements, as well as whole cities urban re-planning. Further, the paper presents initial results of the Aviation Museum in Belgrade preliminary energy refurbishment study focusing results obtained via BPS and co-simulation. Foreseen is the deep energy refurbishment aimed to reach the "total building performance optimization" encompassing multifunctional optimization of building's skin - glazing replacement with the semi-transparent PV glazing and day-lighting control with reference to the artifact preservation, as well as the IEQ (Indoor Environment Quality) control analysis. This study shows that the RES integrated refurbishment can result in the Museum's Zero CO2 emission and even in the sustainable Energy + status (producing more than using electricity). Finally, needs for most current ICT knowledge use and refurbishment technologies development, as well as integrated design, including particularly relevant benchmarking and rating system development are outlined. © 2014 Elsevier B.V. All rights reserved.

Milosavljevic A.,University of Zagreb | Petronic S.,Innovation Center | Polic-Radovanovic S.,Central Institute for Conservation | Babic J.,Military Technical Institute Belgrade | Bajic D.,University of Zagreb
Materiali in Tehnologije | Year: 2012

Nickel-based superalloys are distinguished from other materials by their excellent mechanical and physical properties. As they are used at high temperatures and pressures, as well as in aggressive environments, their characteristics need constant improvement. An adequate choice of their chemical composition and the heat-treatment regime contributes to the improvement of the chemical, physical and mechanical properties of these nickel-based superalloy materials. During the heat treatments of the superalloys Nimonic 263 and Hastelloy S some changes in their microstructures were observed. In this paper the changes in the microstructures after various regimes of the heat treatment were analysed on the fractured surfaces. The fractured surfaces were observed using light microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometry (EDS).

Polic S.,Central Institute for Conservation | Ristic S.,Institut Gosa | Stasic J.,Vinča Institute of Nuclear Sciences | Trtica M.,Vinča Institute of Nuclear Sciences | Radojkovic B.,Institut Gosa
Ceramics International | Year: 2014

This paper presents the results of the morphological and chemical changes on the surface of an Iranian ceramics sample irradiated by a Transversely Excited Atmospheric (TEA) CO2 and an Nd:YAG laser. The sample originates from the archeological site of Yazd (Iran) and is assumed to have been a part of an aqueduct. The effect of laser parameters (energy density (fluency), number of pulses and wavelength) on the induced changes was studied. The tests were performed in order to establish the mechanism of the interaction with the fluence above the damage threshold. This is an essential parameter in the use of lasers for cleaning as well as for eliminating surface defects such as cracks, by melting superficial layers and thus strengthening the objects in question. Another objective was to obtain as much as possible information about the material composition necessary for the conservation and restoration of this ceramics. A TEA CO2 (10.6 μm wavelength, pulse duration 100 ns (Full Width at Half Maximum - FWHM)) laser and an Nd:YAG laser (wavelength 1064 nm and 532 nm, FWHM=150 ps) have been used for the surface treatment. Laser fluences were in the range of 1-20 J/cm2. The ceramics surface morphology modifications, induced by pulsed lasers, were characterized by a scanning electron microscope (SEM), while the composition was examined by energy-dispersive (EDX) and X-ray fluorescence (XRF) spectroscopy. The results show that there are significant differences depending on the laser applied and whether the surface is glazed or not. © 2014 Elsevier Ltd and Techna Group S.r.l.

Jegdic B.,Institut Gosa | Polic-Radovanovic S.,Central Institute for Conservation | Ristic S.,Institut Gosa | Alil A.,Institut Gosa
International Journal of Conservation Science | Year: 2012

A spearhead of archaeological and cultural significance has been found and analysed in Serbia. In the corrosion products of the artefact, the dominant phases were goethite (a-FeO(OH)) and magnetite (Fe3O4) whose presence explains a good preservation of the base metal, iron, over the centuries and the artefact stability after excavation. Besides goethite and magnetite, the corrosion products were identified to contain, to a lesser extent, less stable lepidocrocite (γ-FeO(OH)) and the phases that come from the rocks and soil from the surrounding environment (plagioclase). The phases containing chloride ions were not detected in the corrosion products (akaganéite, β-Fe8O8(OH)8Cl1.35), which indirectly indicates that the content of chloride ions was not significant in the underground exploitation conditions. The lack of chloride ions also contributed to the corrosion stability of the artefact during the period after excavation.

Aleksic M.,Central Institute for Conservation | Savic A.,Central Institute for Conservation | Vasilijevic I.,Central Institute for Conservation
Structural Integrity and Life | Year: 2015

In heritage protection there are always demands for quick and non-invasive techniques of documentation which can provide a wide spectre of information. In practice often used are insufficiently precise techniques that do not give adequate amount of data. In the last decade, digital documentation through use of a 3D laser scanner has become very developed. The aim of the paper is the presentation of the rapid survey of industrial heritage objects at the Old ironworks complex in Smederevo, but also a description of pre-processing and editing of 3D scans as a basis for further static analyses of structural systems. Here described are the basic principles of laser scanner operation as a workflow of performed operations. Special focus is aimed at advantages of this method, but also on its limitations.

Radojkovic B.M.,Institut Gosa | Ristic S.S.,Institut Gosa | Polic-Radovanovic S.R.,Central Institute for Conservation
FME Transactions | Year: 2013

This paper presents the results of the ruby laser light interaction with glass surface. The investigation was conducted in order to determine the maximum density of laser light energy (λ = 694.3 nm, t = 30ns) that can be safely applied in different laser systems used in nondestructive testing methods (NDT). The process of irradiation took place in atmospheric conditions. The results show that interaction of laser beams with glass materials is a complex phenomenon. It depends on many factors and it is associated with localized formation of plasma, heating of the material that leads to melting and transient stresses causing mechanical damages. The zones of laser light interactions were investigated by scanning electron microscope (SEM) with energy-dispersal unit for the analysis of X-ray (EDX). The results obtained by SEM and EDX analysis show that the maximum allowable energy density is 5 J/cm2 for ruby laser light. © Faculty of Mechanical Engineering, Belgrade.

Ristic S.,Institut Gosa | Polic-Radovanovic S.,Central Institute for Conservation
International Journal of Conservation Science | Year: 2013

This paper presents the results of the IR thermographic diagnostics of the seismic damage inflicted upon the ẑ;iĉa Monastery after the earthquake on 3rd November 2010. The ẑiĉa Monastery founded in 13th century is located in central Serbia. The moisture content in the structure was detected too. The obtained results document the current state of the buildings and, at the same time, confirm the advantages of IR thermography as a method in the diagnosis of earthquake cracks, useful for the seismic retrofit study. The obtained results enable the identification of the structure parts where more in-depth investigations need to be concentrated. The procedures and activities for curative conservation and protection of the ẑiĉa Monastery should include the thermographic test results. The results and the conclusions obtained in this case study could be used as example for further extensive studies of historical and cultural heritage buildings.

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