Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 14 2010 Revista Electrónic... more Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 14 2010 Revista Electrónica de Ciências da Terra Geosciences On-line Journal GEOTIC Sociedade Geológica de Portugal VIII Congresso Nacional de Geologia ...
Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 16 2010 Revista Electrónic... more Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 16 2010 Revista Electrónica de Ciências da Terra Geosciences On-line Journal GEOTIC Sociedade Geológica de Portugal VIII Congresso Nacional de Geologia ...
Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 15 2010 Revista Electrónic... more Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 15 2010 Revista Electrónica de Ciências da Terra Geosciences On-line Journal GEOTIC Sociedade Geológica de Portugal VIII Congresso Nacional de Geologia ...
Scientific examination and documentation of art is expensive. The most important and recognizable... more Scientific examination and documentation of art is expensive. The most important and recognizable works of art from prestigious museums get extensive scientific studies, unfeasible for the vast majority of cultural heritage objects, existing in local communities since they lack comparable financial resources. Typically larger museums have budgets sufficient for scientific departments equipped with cutting-edge technologies. In contrast, small to medium sized cultural institutions have relatively limited access to the same science and technology. Cultural Heritage Science Open Source (CHSOS) was launched in 2012 to bridge this technological divide, to develop and disseminate affordable and sustainable methodologies for art examination that can reach a much larger audience of cultural institutions. CHSOS disseminates methods for art examination in three significant ways, focusing specifically on the low-cost technical solutions: its popular blog, publications and training programs. The CHSOS blog has attracted a growing network of art conservation professionals interested in introducing Cultural Heritage Science concepts into their workflow. CHSOS has developed and disseminated low-cost technical solutions for panoramic infrared reflectography [1], technical photography [2,3], reflectance transformation imaging [4] and reflectance spectroscopy [5]. This paper discusses the development of a low-cost multispectral imaging [6] system for art and archaeology realized thanks to the first ever crowdfunding project in art conservation science.
The present article reviews various methods for discontinuity and rock block survey. The variety ... more The present article reviews various methods for discontinuity and rock block survey. The variety of techniques to determine the shape and size distribution of the rock blocks were divided into index and modeling methods. The index methods calculate the average size of a rock block as a representative of the rock mass. These methods are simple, cheap and fast, but are associated with large errors because of the presence of the rock mass of rock blocks with different geometries. Hence, index methods are not recommended. In modeling techniques, discontinuity surveys try to model the rock mass realistically to determine the geometry of all blocks with different algorithms. These methods also have some defects in modeling the discontinuities and calculating the geometry of blocks. In order to perform an evaluation of all methods, six conditions were identified to determine the method for surveying rock blocks. The conditions include the ability to model random discontinuities and joint sets with specific dimensions, the inability to simulate discontinuities with statistical methods (the ability to study a discontinuity network separately), determining the geometry of all rock blocks, considering the dangling and isolated discontinuities, simplicity, and three-dimensionality. Based on the above requirements, a new approach is proposed to determine suitable methods for use in the evaluation of dimension stones. This new methodology was applied in a limestone quarry in Joshqan, Iran, to verify the applicability of the different methods in dimension stone quarries.
The present article reviews various methods for
discontinuity and rock block survey. The variety... more The present article reviews various methods for
discontinuity and rock block survey. The variety of techniques
to determine the shape and size distribution of the
rock blocks were divided into index and modeling methods.
The index methods calculate the average size of a rock
block as a representative of the rock mass. These methods
are simple, cheap and fast, but are associated with large
errors because of the presence of the rock mass of rock
blocks with different geometries. Hence, index methods are
not recommended. In modeling techniques, discontinuity
surveys try to model the rock mass realistically to determine
the geometry of all blocks with different algorithms.
These methods also have some defects in modeling the
discontinuities and calculating the geometry of blocks. In
order to perform an evaluation of all methods, six conditions
were identified to determine the method for surveying
rock blocks. The conditions include the ability to model
random discontinuities and joint sets with specific dimensions,
the inability to simulate discontinuities with statistical
methods (the ability to study a discontinuity network
separately), determining the geometry of all rock blocks,
considering the dangling and isolated discontinuities,
simplicity, and three-dimensionality. Based on the above
requirements, a new approach is proposed to determine
suitable methods for use in the evaluation of dimension
stones. This new methodology was applied in a limestone
quarry in Joshqan, Iran, to verify the applicability of the
different methods in dimension stone quarries.
Bulletin of Engineering Geology and the Environment , 2014
The use of a rock as a building stone is conditioned by several factors, from its aesthetic chara... more The use of a rock as a building stone is conditioned by several factors, from its aesthetic characteristics to its petrophysical properties. Even though the latter are taken into consideration, only a few of them are usually assessed. The purpose of this study is to carry out a comprehensive evaluation of the petrophysical properties of nine Portuguese granites employed as dimension stones. Granites with different textural characteristics and degrees of weathering were selected in order to highlight the relationships between the properties, and to identify the most important ones affecting the rock behaviour. The post-tectonic granites, with low porosity and fewer fissures, show better mechanical behaviour, while the most weathered granites have poor mechanical behaviour that limits their use in some applications and/or environmental conditions. L'utilisation d'une roche comme matériau de construction est conditionnée par plusieurs facteurs, soit les caractéristiques esthétiques ou les propriétés pétrophysiques. Même si ceux-ci sont pris en considération, seuls quelques-unes d'entre elles sont généralement évaluées. L’objectif de cette étude est de réaliser une évaluation complète des propriétés pétrophysiques de neuf granites portugais employés comme pierres de taille. Granites avec différentes textures et degrés d'altération ont été sélectionnés afin de mettre en évidence les relations entre les propriétés, et d'identifier les plus importantes qui conditionnent le comportement de la roche. Les granites post-tectoniques, avec une basse porosité et moins de fissures, présentent un meilleur comportement mécanique, tandis que les granites altérés ont plus mauvais comportement mécanique qui limitent leur utilisation en certaines applications et/ou des conditions environnementales.
It is important to have a thorough knowledge of the petrographic characteristics of rocks to eval... more It is important to have a thorough knowledge of the petrographic characteristics of rocks to evaluate and understand their mechanical behavior. This paper deals with the influence of the texture and the mineral characteristics of nine Portuguese granites employed as dimensional stones. This study evaluates different mineral characteristics, such as mineral deterioration, grain size, quartz fissuration and the contacts between quartz and others mineral groups. The main differences in the studied granites were identified, clarifying the relationship between the petrographic characteristics. The consequences on their respective mechanical behavior were subsequently evaluated. The physical and textural characteristics of quartz in the studied granites have proven to be very important for understanding the behavior of granitic rocks under compressive stress. Uniaxial compressive strength values are not proportional to the quartz–feldspar ratio or quartz content and there is a tendency for strength to decrease with the increase in quartz. This could be related to the increase in quartz-quartz contacts and the decrease in the rock capacity for accommodating the deformation.
Aesthetic characteristics are important when rocks are used as construction materials. Among all ... more Aesthetic characteristics are important when rocks are used as construction materials. Among all the surface finishes available, the polished finish is the one which best enhances the rock attractiveness. Colour (C), roughness (R) and gloss (G) are surface properties usually used to assess the rock polishing. In this research, the CRG properties were assessed in polished samples of three ornamental granites with different textures and physical–mechanical properties, one weathered and two sound. C was evaluated in CIE-L * a * b * and CIE-L * C * ab h ab systems, R with R a and R z parameters and G using the 20°, 60° and 85° geometries. The weathered granite presents a noticeable colour variation, especially in the b * parameter, while the sound ones have a more homogeneous colour. Sound and more textural homogeneous granites have a low surface roughness and high gloss, which are uniformly distributed. The weathered granite shows a higher surface roughness and lower gloss, with scattered distribution. The mineral contacts are the main cause of the surface irregularities. The results show the interdependence between the CRG properties and stress the importance of the polishing process for enhancing the aesthetic characteristics of the granites. CRG properties could be used for quality control in granite processing plants, thus avoiding noticeable differences in the facades of buildings, particularly when weathered granites are used.
Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 14 2010 Revista Electrónic... more Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 14 2010 Revista Electrónica de Ciências da Terra Geosciences On-line Journal GEOTIC Sociedade Geológica de Portugal VIII Congresso Nacional de Geologia ...
Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 16 2010 Revista Electrónic... more Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 16 2010 Revista Electrónica de Ciências da Terra Geosciences On-line Journal GEOTIC Sociedade Geológica de Portugal VIII Congresso Nacional de Geologia ...
Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 15 2010 Revista Electrónic... more Page 1. e-Terra http://e-terra.geopor.pt ISSN 1645-0388 Volume 20 nº 15 2010 Revista Electrónica de Ciências da Terra Geosciences On-line Journal GEOTIC Sociedade Geológica de Portugal VIII Congresso Nacional de Geologia ...
Scientific examination and documentation of art is expensive. The most important and recognizable... more Scientific examination and documentation of art is expensive. The most important and recognizable works of art from prestigious museums get extensive scientific studies, unfeasible for the vast majority of cultural heritage objects, existing in local communities since they lack comparable financial resources. Typically larger museums have budgets sufficient for scientific departments equipped with cutting-edge technologies. In contrast, small to medium sized cultural institutions have relatively limited access to the same science and technology. Cultural Heritage Science Open Source (CHSOS) was launched in 2012 to bridge this technological divide, to develop and disseminate affordable and sustainable methodologies for art examination that can reach a much larger audience of cultural institutions. CHSOS disseminates methods for art examination in three significant ways, focusing specifically on the low-cost technical solutions: its popular blog, publications and training programs. The CHSOS blog has attracted a growing network of art conservation professionals interested in introducing Cultural Heritage Science concepts into their workflow. CHSOS has developed and disseminated low-cost technical solutions for panoramic infrared reflectography [1], technical photography [2,3], reflectance transformation imaging [4] and reflectance spectroscopy [5]. This paper discusses the development of a low-cost multispectral imaging [6] system for art and archaeology realized thanks to the first ever crowdfunding project in art conservation science.
The present article reviews various methods for discontinuity and rock block survey. The variety ... more The present article reviews various methods for discontinuity and rock block survey. The variety of techniques to determine the shape and size distribution of the rock blocks were divided into index and modeling methods. The index methods calculate the average size of a rock block as a representative of the rock mass. These methods are simple, cheap and fast, but are associated with large errors because of the presence of the rock mass of rock blocks with different geometries. Hence, index methods are not recommended. In modeling techniques, discontinuity surveys try to model the rock mass realistically to determine the geometry of all blocks with different algorithms. These methods also have some defects in modeling the discontinuities and calculating the geometry of blocks. In order to perform an evaluation of all methods, six conditions were identified to determine the method for surveying rock blocks. The conditions include the ability to model random discontinuities and joint sets with specific dimensions, the inability to simulate discontinuities with statistical methods (the ability to study a discontinuity network separately), determining the geometry of all rock blocks, considering the dangling and isolated discontinuities, simplicity, and three-dimensionality. Based on the above requirements, a new approach is proposed to determine suitable methods for use in the evaluation of dimension stones. This new methodology was applied in a limestone quarry in Joshqan, Iran, to verify the applicability of the different methods in dimension stone quarries.
The present article reviews various methods for
discontinuity and rock block survey. The variety... more The present article reviews various methods for
discontinuity and rock block survey. The variety of techniques
to determine the shape and size distribution of the
rock blocks were divided into index and modeling methods.
The index methods calculate the average size of a rock
block as a representative of the rock mass. These methods
are simple, cheap and fast, but are associated with large
errors because of the presence of the rock mass of rock
blocks with different geometries. Hence, index methods are
not recommended. In modeling techniques, discontinuity
surveys try to model the rock mass realistically to determine
the geometry of all blocks with different algorithms.
These methods also have some defects in modeling the
discontinuities and calculating the geometry of blocks. In
order to perform an evaluation of all methods, six conditions
were identified to determine the method for surveying
rock blocks. The conditions include the ability to model
random discontinuities and joint sets with specific dimensions,
the inability to simulate discontinuities with statistical
methods (the ability to study a discontinuity network
separately), determining the geometry of all rock blocks,
considering the dangling and isolated discontinuities,
simplicity, and three-dimensionality. Based on the above
requirements, a new approach is proposed to determine
suitable methods for use in the evaluation of dimension
stones. This new methodology was applied in a limestone
quarry in Joshqan, Iran, to verify the applicability of the
different methods in dimension stone quarries.
Bulletin of Engineering Geology and the Environment , 2014
The use of a rock as a building stone is conditioned by several factors, from its aesthetic chara... more The use of a rock as a building stone is conditioned by several factors, from its aesthetic characteristics to its petrophysical properties. Even though the latter are taken into consideration, only a few of them are usually assessed. The purpose of this study is to carry out a comprehensive evaluation of the petrophysical properties of nine Portuguese granites employed as dimension stones. Granites with different textural characteristics and degrees of weathering were selected in order to highlight the relationships between the properties, and to identify the most important ones affecting the rock behaviour. The post-tectonic granites, with low porosity and fewer fissures, show better mechanical behaviour, while the most weathered granites have poor mechanical behaviour that limits their use in some applications and/or environmental conditions. L'utilisation d'une roche comme matériau de construction est conditionnée par plusieurs facteurs, soit les caractéristiques esthétiques ou les propriétés pétrophysiques. Même si ceux-ci sont pris en considération, seuls quelques-unes d'entre elles sont généralement évaluées. L’objectif de cette étude est de réaliser une évaluation complète des propriétés pétrophysiques de neuf granites portugais employés comme pierres de taille. Granites avec différentes textures et degrés d'altération ont été sélectionnés afin de mettre en évidence les relations entre les propriétés, et d'identifier les plus importantes qui conditionnent le comportement de la roche. Les granites post-tectoniques, avec une basse porosité et moins de fissures, présentent un meilleur comportement mécanique, tandis que les granites altérés ont plus mauvais comportement mécanique qui limitent leur utilisation en certaines applications et/ou des conditions environnementales.
It is important to have a thorough knowledge of the petrographic characteristics of rocks to eval... more It is important to have a thorough knowledge of the petrographic characteristics of rocks to evaluate and understand their mechanical behavior. This paper deals with the influence of the texture and the mineral characteristics of nine Portuguese granites employed as dimensional stones. This study evaluates different mineral characteristics, such as mineral deterioration, grain size, quartz fissuration and the contacts between quartz and others mineral groups. The main differences in the studied granites were identified, clarifying the relationship between the petrographic characteristics. The consequences on their respective mechanical behavior were subsequently evaluated. The physical and textural characteristics of quartz in the studied granites have proven to be very important for understanding the behavior of granitic rocks under compressive stress. Uniaxial compressive strength values are not proportional to the quartz–feldspar ratio or quartz content and there is a tendency for strength to decrease with the increase in quartz. This could be related to the increase in quartz-quartz contacts and the decrease in the rock capacity for accommodating the deformation.
Aesthetic characteristics are important when rocks are used as construction materials. Among all ... more Aesthetic characteristics are important when rocks are used as construction materials. Among all the surface finishes available, the polished finish is the one which best enhances the rock attractiveness. Colour (C), roughness (R) and gloss (G) are surface properties usually used to assess the rock polishing. In this research, the CRG properties were assessed in polished samples of three ornamental granites with different textures and physical–mechanical properties, one weathered and two sound. C was evaluated in CIE-L * a * b * and CIE-L * C * ab h ab systems, R with R a and R z parameters and G using the 20°, 60° and 85° geometries. The weathered granite presents a noticeable colour variation, especially in the b * parameter, while the sound ones have a more homogeneous colour. Sound and more textural homogeneous granites have a low surface roughness and high gloss, which are uniformly distributed. The weathered granite shows a higher surface roughness and lower gloss, with scattered distribution. The mineral contacts are the main cause of the surface irregularities. The results show the interdependence between the CRG properties and stress the importance of the polishing process for enhancing the aesthetic characteristics of the granites. CRG properties could be used for quality control in granite processing plants, thus avoiding noticeable differences in the facades of buildings, particularly when weathered granites are used.
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works of art from prestigious museums get extensive scientific studies, unfeasible for the vast
majority of cultural heritage objects, existing in local communities since they lack comparable
financial resources. Typically larger museums have budgets sufficient for scientific departments
equipped with cutting-edge technologies. In contrast, small to medium sized cultural institutions
have relatively limited access to the same science and technology.
Cultural Heritage Science Open Source (CHSOS) was launched in 2012 to bridge this technological
divide, to develop and disseminate affordable and sustainable methodologies for art examination
that can reach a much larger audience of cultural institutions. CHSOS disseminates methods for art
examination in three significant ways, focusing specifically on the low-cost technical solutions: its
popular blog, publications and training programs. The CHSOS blog has attracted a growing network
of art conservation professionals interested in introducing Cultural Heritage Science concepts into
their workflow.
CHSOS has developed and disseminated low-cost technical solutions for panoramic infrared
reflectography [1], technical photography [2,3], reflectance transformation imaging [4] and
reflectance spectroscopy [5]. This paper discusses the development of a low-cost multispectral
imaging [6] system for art and archaeology realized thanks to the first ever crowdfunding project
in art conservation science.
discontinuity and rock block survey. The variety of techniques
to determine the shape and size distribution of the
rock blocks were divided into index and modeling methods.
The index methods calculate the average size of a rock
block as a representative of the rock mass. These methods
are simple, cheap and fast, but are associated with large
errors because of the presence of the rock mass of rock
blocks with different geometries. Hence, index methods are
not recommended. In modeling techniques, discontinuity
surveys try to model the rock mass realistically to determine
the geometry of all blocks with different algorithms.
These methods also have some defects in modeling the
discontinuities and calculating the geometry of blocks. In
order to perform an evaluation of all methods, six conditions
were identified to determine the method for surveying
rock blocks. The conditions include the ability to model
random discontinuities and joint sets with specific dimensions,
the inability to simulate discontinuities with statistical
methods (the ability to study a discontinuity network
separately), determining the geometry of all rock blocks,
considering the dangling and isolated discontinuities,
simplicity, and three-dimensionality. Based on the above
requirements, a new approach is proposed to determine
suitable methods for use in the evaluation of dimension
stones. This new methodology was applied in a limestone
quarry in Joshqan, Iran, to verify the applicability of the
different methods in dimension stone quarries.
works of art from prestigious museums get extensive scientific studies, unfeasible for the vast
majority of cultural heritage objects, existing in local communities since they lack comparable
financial resources. Typically larger museums have budgets sufficient for scientific departments
equipped with cutting-edge technologies. In contrast, small to medium sized cultural institutions
have relatively limited access to the same science and technology.
Cultural Heritage Science Open Source (CHSOS) was launched in 2012 to bridge this technological
divide, to develop and disseminate affordable and sustainable methodologies for art examination
that can reach a much larger audience of cultural institutions. CHSOS disseminates methods for art
examination in three significant ways, focusing specifically on the low-cost technical solutions: its
popular blog, publications and training programs. The CHSOS blog has attracted a growing network
of art conservation professionals interested in introducing Cultural Heritage Science concepts into
their workflow.
CHSOS has developed and disseminated low-cost technical solutions for panoramic infrared
reflectography [1], technical photography [2,3], reflectance transformation imaging [4] and
reflectance spectroscopy [5]. This paper discusses the development of a low-cost multispectral
imaging [6] system for art and archaeology realized thanks to the first ever crowdfunding project
in art conservation science.
discontinuity and rock block survey. The variety of techniques
to determine the shape and size distribution of the
rock blocks were divided into index and modeling methods.
The index methods calculate the average size of a rock
block as a representative of the rock mass. These methods
are simple, cheap and fast, but are associated with large
errors because of the presence of the rock mass of rock
blocks with different geometries. Hence, index methods are
not recommended. In modeling techniques, discontinuity
surveys try to model the rock mass realistically to determine
the geometry of all blocks with different algorithms.
These methods also have some defects in modeling the
discontinuities and calculating the geometry of blocks. In
order to perform an evaluation of all methods, six conditions
were identified to determine the method for surveying
rock blocks. The conditions include the ability to model
random discontinuities and joint sets with specific dimensions,
the inability to simulate discontinuities with statistical
methods (the ability to study a discontinuity network
separately), determining the geometry of all rock blocks,
considering the dangling and isolated discontinuities,
simplicity, and three-dimensionality. Based on the above
requirements, a new approach is proposed to determine
suitable methods for use in the evaluation of dimension
stones. This new methodology was applied in a limestone
quarry in Joshqan, Iran, to verify the applicability of the
different methods in dimension stone quarries.