991 resultados para Material heritage
Resumo:
Almost every community, country and continent is experiencing a form of conflict, war or disaster. These wars have claimed lives, antiquities, heritage materials, contemporary Arts, Galleries, Museums, Archives, Monuments andHeritage sites. The aim of this study is to explore the challenges of safeguarding cultural heritage material during violent conflict in Nigeria bearing in mind the two UNESCO world heritage sites in Nigeria: Sukur kingdom and Osun Oshogbo sacred Grove. The outcome of this study will help the policy makers to address the challenges of safeguarding cultural heritage materials in times of conflicts, bridge the gap on the existing literature concerning the safeguarding of cultural heritage materials in times of conflict and to make a modest contribution to the existing body of knowledge on cultural heritage protection in Nigeria in particular and other parts of the world in general. This study relies on both primary and secondary sources using questionnaire and oral interview to elicit information from selected relevant cultural agencies, journalists and scholars in the field of art and culture. Relevant literature and documents on the challenges of safeguarding and securing of cultural heritage materials during conflicts were reviewed. The data gathered from the questionnaires and the oral interview is presented in frequency tabular form to give precise and comprehensive insight into the study findings. Notable among the challenges were insecurity and lack of professionalism in the field of cultural heritage profession. The study also revealed that governments are not enforcing the global laws and conventions for the protection of cultural heritage materials in times of violent conflict. The communities where these materials are located have little or no knowledge about the import of these materials and do not take part in securing them in the event of conflict. It is crucial that we place high value on heritage materials since they are inextricably linked with our identity and where we come from. It is strongly recommended that Cultural Heritage Institutions should involve as much as possible the local communities living around the sites by creating awareness educating and encouraging them to take ownership of the Sites located within their communities. They must ensure that the site is safeguarded against all forms of threat. Items of heritage value are not often considered in most disaster management plans therefore there is the need to consider heritage as priority just as the protection of lives and property.
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This paper deals with the relationship between different sets of archaeological legislation, material culture and communities. First it presents a historical sketch of the heritage legislation in the West and its contemporary uses. Secondly, it shows how alternative archaeological agencies, such as community archaeology, deal with these problems. The discussion is especially relevant in Brazil, where contract archaeology is presently overwhelming, and the issue is raised in the last part of the paper.
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Conventional descriptions place conservation activities between the two poles of active restorative intervention and passive abandonment. This paper proposes that site stewards at mining heritage sites often follow presentation strategies that sit outside this neat dualism. Drawing on material presented in the form of three case studies, this paper identifies the actions these strategies entail and considers the results in terms of an aesthetic of decay. To consolidate the argument, a new overarching term is introduced to describe this strategy: contrived dereliction, in order to foreground its essential features. The paper then outlines the advantages, limitations and requirements of contrived dereliction as a heritage management and presentation practice.
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O presente trabalho visa contribuir com a conceção e implementação de uma plataforma web na área do turismo e da cultura, mais especificamente dedicada ao património (i)material, a cidade de Aveiro. A ambição do projeto é apresentar às pessoas que façam o uso do site www.imaterialaveiro.yolasite.com, o que está por trás de determinados aspetos que caracterizam a cidade de Aveiro, em especial o componente cultural, simbólico e histórico que não pode ser visto facilmente. O projeto tem dois grandes objetivos, o primeiro é fazer um levantamento bibliográfico do que já foi escrito sobre os media locativos e território hipermediatizado, tentando identificar definições dadas por autores diferentes, os exemplos trazidos por esses autores acerca destes media locativos num território hipermediatizado e qual o papel cultural desses dois elementos tecnológicos na atualidade. O segundo grande objetivo é a criação de um mapa virtual baseado em geolocalização. O projeto ImaterialAveiro terá como propósito transmitir através de vídeos o patrimônio (i)material da cidade de Aveiro. A escolha destes patrimônios (i)materiais será um grande desafio no trabalho, tendo em vista que a UNESCO, que é o órgão responsável pela identificação deste tipo de patrimônio, ainda não reconheceu nenhum aspeto da cidade de Aveiro como patrimônio imaterial. Logo, a escolha far-seá com a ajuda dos agentes locais, sendo assim, também, um desafio de cidadania participante. O projeto pretende contribuir para a análise dos media locativos e para a reflexão sobre a sua influência na experiência das cidades, além de deixar para a cidade de Aveiro um exemplo de como interagir com a cultura intangível através da geolocalização.
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A collaboration between dot.rural at the University of Aberdeen and the iSchool at Northumbria University, POWkist is a pilot-study exploring potential usages of currently available linked datasets within the cultural heritage domain. Many privately-held family history collections (shoebox archives) remain vulnerable unless a sustainable, affordable and accessible model of citizen-archivist digital preservation can be offered. Citizen-historians have used the web as a platform to preserve cultural heritage, however with no accessible or sustainable model these digital footprints have been ad hoc and rarely connected to broader historical research. Similarly, current approaches to connecting material on the web by exploiting linked datasets do not take into account the data characteristics of the cultural heritage domain. Funded by Semantic Media, the POWKist project is investigating how best to capture, curate, connect and present the contents of citizen-historians’ shoebox archives in an accessible and sustainable online collection. Using the Curios platform - an open-source digital archive - we have digitised a collection relating to a prisoner of war during WWII (1939-1945). Following a series of user group workshops, POWkist is now connecting these ‘made digital’ items with the broader web using a semantic technology model and identifying appropriate linked datasets of relevant content such as DBPedia (an archived linked dataset of Wikipedia) and Ordnance Survey Open Data. We are analysing the characteristics of cultural heritage linked datasets, so that these materials are better visualised, contextualised and presented in an attractive and comprehensive user interface. Our paper will consider the issues we have identified, the solutions we are developing and include a demonstration of our work-in-progress.
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In today’s world heritage worldwide are at the risk not only because of natural process of decay and destruction but also by social change like urbanization, globalization and homogenization of cultures. With these emerging problems, the heritage conservation discourse also has reached to a new dimension including broader range of concepts like tangible heritage, intangible heritage, community participation, indigenous knowledge and many more. Even with the changing scenario in the international context about the heritage conservation, Nepal’s heritage conservation still focus on monuments, sites and buildings. In add to that the conservation practices are still top-down approach and community involvements are limited only in plans. While numerous intangible heritages like masking dances chariot processions, festivals and rituals, which form an integral part of the daily social life of people are still being continued and managed by the community and its people, without with out serious attention form the government. In Kathmandu Valley these heritages has been maintained with the traditional social association of people known as “Guthi” which has been continuing since 5th Century. Most of the tangible and intangible heritages have survived for centuries because of this unique association of people. Among the numerous festivals of the Kathmandu Valley, the festival Yenya Punhi was chosen as a case for this study, which is also a major festival of Kathmandu. This festival is the perfect example for the study as its celebrated in the city that is the most urbanized city of Nepal with the challenges of the every modern city like social changes and urbanization. Despite modern challenges Guthi still plays a major role in the heritage conservation in Kathmandu Valley. Now there are some interventions of the various formal institutions. So this study will be focusing on the management, continuity and problems of the festival along with Nepal’s position in terms of intangible heritage conservation. The problem of Kathmandu and Yenya Punhi festival is the problem of every country in the similar situation so with this case study it can be a good example for finding solutions of the similar problem not only the other festivals within Nepal but also elsewhere in the world; Resumo: Conexão de Património: Festival Yenya Punhi um caminho de fortalecimento de identidade: A experiência de Catmandu Nos dias de hoje, os patrimónios mundiais encontram-se em risco, não só devido ao processo natural de degradação e destruição, mas também pelas mudanças sociais, tais como a urbanização, globalização e homogeneização de culturas. Com o emergir destes problemas, o discurso de conservação de Património atingiu também uma nova dimensão, incluíndo uma área mais abrangente de conceitos, como por exemplo, património material, património imaterial, participação da comunidade, conhecimento indígena, entre outros. Mesmo com este cenário de mudança no contexto mundial de conservação do património, a preservação do património do Nepal continua a focar-se em monumentos, sítios e edíficios. A acrescentar a isso, as práticas de conservação ainda têm uma abordagem descendente e os envolvimentos da comunidade são limitados por planificações. Enquanto que os numerosos patrimónios imateriais como danças com máscaras, procissões, festivais e rituais, os quais formam uma parte integral da vida diária social das pessoas que as continuam e as gerem em comunidade, sem uma atenção séria por parte do governo. No Vale de Catmandu, este património tem sido mantido pela associação tradicional de pessoas conhecidas como ''Guthi'' desde o século V. A maior parte destes patrimónios materiais e imateriais tem sobrevivido durante séculos graças a esta associação única de pessoas. Entre os numerosos festivais do Vale de Catmandu, o festival Yenya Puhni foi escolhido para este estudo, pois é também um grande festival em Catmandu. Este festival é o exemplo perfeito para este estudo, pois é celebrado na cidade mais urbanizada do Nepal, com os desafios das cidades modernas tais como mudanças sociais e urbanização. Apesar dos desafios da modernização, os ''Guthi'' ainda desempenham um papel importante na preservação do património do Vale de Catmandu. Agora, existem algumas intervenções de várias instituições formais Então, este estudo irá focar-se na gestão, continuidade e problemas do festival, juntamente com a posição do Nepal em termos de conservação de património imaterial. O problema de Catmandu e do festival Yenya Punhi é o problema de todos os países em situação semelhante então, este estudo pode ser um bom exemplo para encontrar soluções de problemas parecidos, não só em outros festivais no Nepal mas também para qualquer parte do mundo.
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Natural stone has been a popular and reliable building material throughout history appearing in many historic monuments and in more recent buildings. Research into the intrinsic properties of specific stones is important because it gives us a greater understanding of the factors that limit and act on them. This can help prevent serious problems from occurring in our buildings bringing both esthetic benefits and financial savings. To this end, the main objective of this research has been to study the influence of the fabric and the mineral composition of two types of sandstone on their durability. The first is a red continental sandstone from the Buntsandstein Age called “Molinaza Roja”, which is quarried in Montoro (Cordoba). The second is quarried in Ronda (Malaga) and is sold under the trade name of “Arenisca Ronda”. It is a light pink-whitish calcarenite deposited during the Late Tortonian to Late Messinian. We characterized their petrological and petrophysical properties by studying their rock fabrics, porous systems and mechanical properties. In order to obtain a complete vision of the behavior of their rock fabrics, we also carried out two decay tests, the salt crystallization and the freeze–thaw tests. We then measured the effects on the textures of the altered samples during and after the decay tests and we evaluated the changes in the porous system. By comparing the results between intact and altered samples, we found that Arenisca Ronda is less durable because it has a high quantity of expandable clays (smectites) and a high percentage of pores in the 0.1–1 μm range, in which the pressure produced by salt crystallization is strongest. In Molinaza Roja the decay agents caused significant sanding due to loss of cohesion between the clasts, especially during the salt crystallization test. In both stones, the anisotropies (oriented textures) have an important role in their hydric and dynamic behavior and also affect their mechanical properties (especially in the compression resistance). No changes in color were detected.
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Nowadays, one of the most important areas of interest in archeology is the characterization of the submersed cultural heritage. Mediterranean Sea is rich in archaeological findings due to storms, accidents and naval battles since prehistoric times. Chemical analysis of submerged materials is an extremely valuable source of information on the origin and precedence of the wrecks, and also the raw materials employed during the manufacturing of the objects found in these sites. Nevertheless, sometimes it is not possible to extract the archaeological material from the marine environment due to size of the sample, the legislation or preservation purposes. In these cases, the in-situ analysis turns into the only alternative for obtaining information. In spite of this demand, no analytical techniques are available for the in-situ chemical characterization of underwater materials. The versatility of laser-induced breakdown spectroscopy (LIBS) has been successfully tested in oceanography 1. Advantages such as rapid and in situ analysis with no sample preparation make LIBS a suitable alternative for field measurements. To further exploit the inherent advantages of the technology, a mobile fiber-based LIBS platform capable of performing remote measurements up to 50 meters range has been designed for the recognition and identification of artworks in underwater archaeological shipwrecks. The LIBS prototype featured both single-pulse (SP-LIBS) and multi-pulse excitation (MP-LIBS) 2. The use of multi-pulse excitation allowed an increased laser beam energy (up to 95 mJ) transmitted through the optical fiber. This excitation mode results in an improved performance of the equipment in terms of extended range of analysis (to a depth of 50 m) and a broader variety of samples to be analyzed (i.e., rocks, marble, ceramics and concrete). In the present work, the design and construction considerations of the instrument are reported and its performance is discussed on the basis of the spectral response, the remote irradiance achieved upon the range of analysis and its influence on plasma properties, as well as the effect of the laser pulse duration and purge gas to the LIBS signal. Also, to check the reliability and reproducibility of the instrument for field analysis several robustness tests were performed outside the lab. Finally, the capability of this instrument was successfully demonstrated in an underwater archaeological shipwreck (San Pedro de Alcántara, Malaga).
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The conservation and valorisation of cultural heritage is of fundamental importance for our society, since it is witness to the legacies of human societies. In the case of metallic artefacts, because corrosion is a never-ending problem, the correct strategies for their cleaning and preservation must be chosen. Thus, the aim of this project was the development of protocols for cleaning archaeological copper artefacts by laser and plasma cleaning, since they allow the treatment of artefacts in a controlled and selective manner. Additionally, electrochemical characterisation of the artificial patinas was performed in order to obtain information on the protective properties of the corrosion layers. Reference copper samples with different artificial corrosion layers were used to evaluate the tested parameters. Laser cleaning tests resulted in partial removal of the corrosion products, but the lasermaterial interactions resulted in melting of the desired corrosion layers. The main obstacle for this process is that the materials that must be preserved show lower ablation thresholds than the undesired layers, which makes the proper elimination of dangerous corrosion products very difficult without damaging the artefacts. Different protocols should be developed for different patinas, and real artefacts should be characterised previous to any treatment to determine the best course of action. Low pressure hydrogen plasma cleaning treatments were performed on two kinds of patinas. In both cases the corrosion layers were partially removed. The total removal of the undesired corrosion products can probably be achieved by increasing the treatment time or applied power, or increasing the hydrogen pressure. Since the process is non-invasive and does not modify the bulk material, modifying the cleaning parameters is easy. EIS measurements show that, for the artificial patinas, the impedance increases while the patina is growing on the surface and then drops, probably due to diffusion reactions and a slow dissolution of copper. It appears from these results that the dissolution of copper is heavily influenced by diffusion phenomena and the corrosion product film porosity. Both techniques show good results for cleaning, as long as the proper parameters are used. These depend on the nature of the artefact and the corrosion layers that are found on its surface.
Resumo:
Airborne Particulate Matter (PM), can get removed from the atmosphere through wet and dry mechanisms, and physically/chemically interact with materials and induce premature decay. The effect of dry depositions is a complex issue, especially for outdoor materials, because of the difficulties to collect atmospheric deposits repeatable in terms of mass and homogeneously distributed on the entire investigated substrate. In this work, to overcome these problems by eliminating the variability induced by outdoor removal mechanisms (e.g. winds and rainfalls), a new sampling system called ‘Deposition Box’, was used for PM sampling. Four surrogate materials (Cellulose Acetate, Regenerated Cellulose, Cellulose Nitrate and Aluminum) with different surfaces features were exposed in the urban-marine site of Rimini (Italy), in vertical and horizontal orientations. Homogeneous and reproducible PM deposits were obtained and different analytical techniques (IC, AAS, TOC, VP-SEM-EDX, Vis-Spectrophotometry) were employed to characterize their mass, dimension and composition. Results allowed to discriminate the mechanisms responsible of the dry deposition of atmospheric particles on surfaces with different nature and orientation and to determine which chemical species, and in which amount, tend to preferentially deposit on them. This work demonstrated that “Deposition Box” can represent an affordable tool to study dry deposition fluxes on materials and results obtained will be fundamental in order to extend this kind of exposure to actual building and heritage materials, to investigate the PM contribution in their decay.
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Among the most representative materials of XX Century architectural heritage, this dissertation focuses on the cement-based ones, investigating some different fields where they were exploited. Primarily, concerning the surface preservation of cement-based materials used with aesthetic intent, new self-cleaning treatments based on titania nanoparticles embedded in inorganic matrices were tested. In order to consider the role of porosity, the treatments were applied to different kinds of materials (cement-based mortar, marble and concrete) and several analyses were conducted to investigate the morphology of the coatings, their photocatalytic effectiveness, their durability and the interaction between the coating and the substrate material. The outcomes showed that several parameters influence the treatment’s performances, in particular, the presence and nature of the matrix, the concentration and dispersion of nanoparticles and, in some cases, the amount of substrate material which interacts with the coatings. Secondly, this dissertation deals with the historic “Terranova” render, a colored dry-mix mortar largely widespread in Europe in the first half of XX Century, whose formulation is still basically unknown. Some original samples of supposedly Terranova renders were subjected to several characterization analyses and the results were compared to those of the original “Terranova” render of the Engineering Faculty in Bologna. Despite the recurrence of some features, defining a common formulation seemed to be challenging. Finally, the repair and conservation of structural reinforced concrete in heritage buildings were investigated, adopting the former “Casa del Fascio” in Predappio (FC, Italy) as case study. Three different materials and solutions were tested on a slab of the building, making its repair only from the intrados. Then several analyses were conducted both on site and in laboratory. Aside from the specific features characterizing every product, the results highlighted that the application method played a fundamental role in the effectiveness of the retrofit strategies.
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Although various abutment connections and materials have recently been introduced, insufficient data exist regarding the effect of stress distribution on their mechanical performance. The purpose of this study was to investigate the effect of different abutment materials and platform connections on stress distribution in single anterior implant-supported restorations with the finite element method. Nine experimental groups were modeled from the combination of 3 platform connections (external hexagon, internal hexagon, and Morse tapered) and 3 abutment materials (titanium, zirconia, and hybrid) as follows: external hexagon-titanium, external hexagon-zirconia, external hexagon-hybrid, internal hexagon-titanium, internal hexagon-zirconia, internal hexagon-hybrid, Morse tapered-titanium, Morse tapered-zirconia, and Morse tapered-hybrid. Finite element models consisted of a 4×13-mm implant, anatomic abutment, and lithium disilicate central incisor crown cemented over the abutment. The 49 N occlusal loading was applied in 6 steps to simulate the incisal guidance. Equivalent von Mises stress (σvM) was used for both the qualitative and quantitative evaluation of the implant and abutment in all the groups and the maximum (σmax) and minimum (σmin) principal stresses for the numerical comparison of the zirconia parts. The highest abutment σvM occurred in the Morse-tapered groups and the lowest in the external hexagon-hybrid, internal hexagon-titanium, and internal hexagon-hybrid groups. The σmax and σmin values were lower in the hybrid groups than in the zirconia groups. The stress distribution concentrated in the abutment-implant interface in all the groups, regardless of the platform connection or abutment material. The platform connection influenced the stress on abutments more than the abutment material. The stress values for implants were similar among different platform connections, but greater stress concentrations were observed in internal connections.
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The present paper describes the synthesis of molecularly imprinted polymer - poly(methacrylic acid)/silica and reports its performance feasibility with desired adsorption capacity and selectivity for cholesterol extraction. Two imprinted hybrid materials were synthesized at different methacrylic acid (MAA)/tetraethoxysilane (TEOS) molar ratios (6:1 and 1:5) and characterized by FT-IR, TGA, SEM and textural data. Cholesterol adsorption on hybrid materials took place preferably in apolar solvent medium, especially in chloroform. From the kinetic data, the equilibrium time was reached quickly, being 12 and 20 min for the polymers synthesized at MAA/TEOS molar ratio of 6:1 and 1:5, respectively. The pseudo-second-order model provided the best fit for cholesterol adsorption on polymers, confirming the chemical nature of the adsorption process, while the dual-site Langmuir-Freundlich equation presented the best fit to the experimental data, suggesting the existence of two kinds of adsorption sites on both polymers. The maximum adsorption capacities obtained for the polymers synthesized at MAA/TEOS molar ratios of 6:1 and 1:5 were found to be 214.8 and 166.4 mg g(-1), respectively. The results from isotherm data also indicated higher adsorption capacity for both imprinted polymers regarding to corresponding non-imprinted polymers. Nevertheless, taking into account the retention parameters and selectivity of cholesterol in the presence of structurally analogue compounds (5-α-cholestane and 7-dehydrocholesterol), it was observed that the polymer synthesized at the MAA/TEOS molar ratio of 6:1 was much more selective for cholesterol than the one prepared at the ratio of 1:5, thus suggesting that selective binding sites ascribed to the carboxyl group from MAA play a central role in the imprinting effect created on MIP.
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Surgical treatment for enterocutaneous fistulas (EF) frequently fails. Cell therapy may represent a new approach to treatment. Mesenchymal stromal cells (MSCs) have high proliferative and differentiation capacity. This study aimed to investigate whether MSCs could adhere to suture filament (SF), promoting better EF healing. MSCs, 1 × 10(6), from adipose tissue (ATMSCs) were adhered to a Polyvicryl SF by adding a specific fibrin glue formulation. Adhesion was confirmed by confocal and scanning electron microscopy (SEM). A cecal fistula was created in 22 Wistar rats by incising the cecum and suturing the opening to the surgical wound subcutaneously with four separate stitches. The animals were randomly allocated to three groups: control (CG)-five animals, EF performed; injection (IG)-eight animals 1 × 10(6) ATMSCs injected around EF borders; and suture filament (SG): nine animals, sutured with 1 × 10(6) ATMSCs attached to the filaments with fibrin glue. Fistulas were photographed on the operation day and every 3 days until the 21st day and analyzed by two observers using ImageJ Software. Confocal and SEM results demonstrated ATMSCs adhered to SF (ATMSCs-SF). The average reduction size of the fistula area at 21st day was greater for the SG group (90.34%, P < 0.05) than the IG (71.80%) and CG (46.54%) groups. ATMSCs adhered to SF maintain viability and proliferative capacity. EF submitted to ATMSCs-SF procedure showed greater recovery and healing. This approach might be a new and effective tool for EF treatment.
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Jute fiber is the second most common natural cellulose fiber worldwide, especially in recent years, due to its excellent physical, chemical and structural properties. The objective of this paper was to investigate: the thermal degradation of in natura jute fiber, and the production and characterization of the generated activated carbon. The production consisted of carbonization of the jute fiber and activation with steam. During the activation step the amorphous carbon produced in the initial carbonization step reacted with oxidizing gas, forming new pores and opening closed pores, which enhanced the adsorptive capacity of the activated carbon. N2 gas adsorption at 77K was used in order to evaluate the effect of the carbonization and activation steps. The results of the adsorption indicate the possibility of producing a porous material with a combination of microporous and mesoporous structure, depending on the parameters used in the processes, with resulting specific surface area around 470 m2.g-1. The thermal analysis indicates that above 600°C there is no significant mass loss.