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In the extractive industry of carbonated ornamental rocks, the presence of discontinuities, size of grain, colour, textural anisotropy and porosity are factors that determine the extraction planning and their economic viability. This characterization is important for the planning and scaling of the exploitation. The objective of this work was in first, using the penetration radar in the soil (GPR), to identify and determine the spatial distribution of these elements. The choice of this non-destructive geophysical method to perform the work was because it is a fast method of inspection, having a good horizontal and vertical resolution, and relative precision. for this purpose, a PULSEEKKO GPR (SENSORS & SOFTWARE) acquisition equipment was used, with a system of two bi-static antennas (transmitter and receiver), unshielded, with a frequency of 100 MHz, using the reflection method with a common offset and with an antenna separation of 1,00 meter (m), at the pre-defined locations at each level of the quarry. The acquired data were subsequently processed in the REFLEXW® vers. Software. 7.5.9, from SANDMEIER-GEO®. The multiple profiles obtained (radargrams) [1], [2], which were compared with the corresponding exploitation fronts. This comparison allows validating the methodology used in the identification of existing structures, their vertical and horizontal limits and spatial relations between them.
Joao Duarte; Jose Carvalho; Fernando Figueiredo. Use of Ground Penetration Radar (GPR) in the Evaluation of Geological-Structural Elements of Ornamental Carbonated Rocks - Case Study in Valinho De Fatima, Portugal. IOP Conference Series: Earth and Environmental Science 2019, 362, 012101 .
AMA StyleJoao Duarte, Jose Carvalho, Fernando Figueiredo. Use of Ground Penetration Radar (GPR) in the Evaluation of Geological-Structural Elements of Ornamental Carbonated Rocks - Case Study in Valinho De Fatima, Portugal. IOP Conference Series: Earth and Environmental Science. 2019; 362 (1):012101.
Chicago/Turabian StyleJoao Duarte; Jose Carvalho; Fernando Figueiredo. 2019. "Use of Ground Penetration Radar (GPR) in the Evaluation of Geological-Structural Elements of Ornamental Carbonated Rocks - Case Study in Valinho De Fatima, Portugal." IOP Conference Series: Earth and Environmental Science 362, no. 1: 012101.
In this paper, the importance of the dolostone (a carbonate sedimentary rock where the dominant carbonate mineral is dolomite) in monuments and urban buildings of the city of Coimbra, Portugal, is highlighted. Old quarries are not visible in the nucleus of the city, due to the sequential occupation by houses, and can only be identified by documentation (draws, contract letters and purchase orders). However, on the southern side of Mondego River (Santa Clara) some outcrops can be observed and were exploited until the mid-20th. It is presented a list of the old quarries and monuments made with this rock. The characterization of dolostones from the Coimbra Formation is also presented. It is made the connection between the local geology and the “identity” of Coimbra, putting in evidence the stone as a symbol that characterize the gilded aspect of the buildings. For restoration and rehabilitation works, a small number of blocks could be extracted from the Carvalhais quarry if were eventually necessary.
Lidia Catarino; Roque Figueiredo; Fernando Figueiredo; Pedro Andrade; João Duarte. The Use of Dolostone in Historical Buildings of Coimbra (Central Portugal). Sustainability 2019, 11, 4158 .
AMA StyleLidia Catarino, Roque Figueiredo, Fernando Figueiredo, Pedro Andrade, João Duarte. The Use of Dolostone in Historical Buildings of Coimbra (Central Portugal). Sustainability. 2019; 11 (15):4158.
Chicago/Turabian StyleLidia Catarino; Roque Figueiredo; Fernando Figueiredo; Pedro Andrade; João Duarte. 2019. "The Use of Dolostone in Historical Buildings of Coimbra (Central Portugal)." Sustainability 11, no. 15: 4158.
In the extractive and transformation processing industry of ornamental rocks, the presence of discontinuities, grain size, porosity and textural anisotropies in the explored blocks is an economic risk factor. This study aims the identification and possible quantification of these elements. The existence of a low-cost, non-intrusive and fast inspection method for the evaluation of blocks would facilitate their use avoiding their wastage. For this purpose, two nondestructive methods ("P" Wave Ultrasonic Testing and the Ground Penetration Radar (GPR)) were tested on a limestone rock block and compared the models obtained. The portable ultrasound equipment used was a Proceq Pundit Lab (Portable Ultrasonic Non-Destructive Digital Indicating Tester) which is based on the pulse rate method with 54 KHz to provide information about the uniformity, cavities, cracks and defects of the material concerned by the measurement of the ultrasonic wave time and the measurement of the pulse rate. The equipment used for the GPR data acquisition was a PULSEEKKO GPR (SENSORS & SOFTWARE), with a system of two bistatic antennas (transmitter and receiver) with a frequency of 1 GHz, using the reflection method with a common offset and with an antenna separation of 0,15 meters [m]. To make a comparison of the results valid and representative, both tests were performed with 0,10 m spacing between measurements, according to a pre-defined and common grid. In the case of the ultrasonic test, velocity color maps were created based on the results of the measurements, and through this colors differences it was possible to detect and locate some of the individual and visible fractures, but also not visible fractures on the surface of the tested face. By increasing the distance between transducers, the measurement depth also increases, creating maps of the same face at different depths. This method allows us to create several GPR profiles (radargrams) were obtained because of the processing, and were used to create 2, 2,5 and 3D models to identify the existing structures, their vertical and horizontal limits and spatial relationships between them.
Joao Duarte; Daniela Pedrosa; Jose Carvalho; Fernando Figueiredo; Lidia Catarino. Use of Non-Destructive Methods in Structural Analysis of Petrous Materials - Ultrasonic Testing and Ground Penetrating Radar (GPR). IOP Conference Series: Earth and Environmental Science 2019, 221, 012061 .
AMA StyleJoao Duarte, Daniela Pedrosa, Jose Carvalho, Fernando Figueiredo, Lidia Catarino. Use of Non-Destructive Methods in Structural Analysis of Petrous Materials - Ultrasonic Testing and Ground Penetrating Radar (GPR). IOP Conference Series: Earth and Environmental Science. 2019; 221 (1):012061.
Chicago/Turabian StyleJoao Duarte; Daniela Pedrosa; Jose Carvalho; Fernando Figueiredo; Lidia Catarino. 2019. "Use of Non-Destructive Methods in Structural Analysis of Petrous Materials - Ultrasonic Testing and Ground Penetrating Radar (GPR)." IOP Conference Series: Earth and Environmental Science 221, no. 1: 012061.
The recent use and availability of small and low cost Unmanned Aerial Systems (UAS) and the development of Open Source Photogrammetric (OSP) software opens new opportunities for their intensive use in topographic monitoring of foredune dynamics. This study assesses the accuracy and effectiveness of high resolution Digital Surface Models (DSM) generated by the combined use of low-altitude UAS imagery and OSP software. The Photogrammetric Workflow (PW) has been optimized to address the use an action camera and non-autonomous flight mode. To evaluate the accuracy of the DSMs derived from dense matching of UAS imagery we use a reference DSM obtained by a Terrestrial Laser Scanner in the same survey period. Moreover, we use robust statistical indicators for assessing the vertical accuracy of both DSMs: the raw DSM and the denoised DSM. The results shows that a detailed UAS-based DSM with a spatial resolution of 5 cm and vertical accuracy of 10 cm (robust root mean square error) can be obtained by using the proposed PW. The results also suggest that this low cost technology can be used effectively for 3D mapping of foredunes.
Gil Rito Gonçalves; Juan Antonio Pérez; João Duarte. Accuracy and effectiveness of low cost UASs and open source photogrammetric software for foredunes mapping. International Journal of Remote Sensing 2018, 39, 5059 -5077.
AMA StyleGil Rito Gonçalves, Juan Antonio Pérez, João Duarte. Accuracy and effectiveness of low cost UASs and open source photogrammetric software for foredunes mapping. International Journal of Remote Sensing. 2018; 39 (15-16):5059-5077.
Chicago/Turabian StyleGil Rito Gonçalves; Juan Antonio Pérez; João Duarte. 2018. "Accuracy and effectiveness of low cost UASs and open source photogrammetric software for foredunes mapping." International Journal of Remote Sensing 39, no. 15-16: 5059-5077.
This work aims to be a further contribution to the numerous studies that have been carried out under the prospecting of groundwater in the Cape Verde archipelago (Pina, 2009; Duarte, 2017). The application of the method has aimed to evaluate acquisition geometry in volcanic environments, to maximize and contribute to the geological, structural and hydrogeological interpretation of the area of research, and evaluation of the model of distribution of Resistivitys with lithologies distribution model (probing holes). The spatial distribution of the surveys was chosen in such a way as to coincide with the places where this drilling was effected. The work carried out was carried out in the locality of Ribeirão do Chiqueiro, the Santiago Island, where electromagnetic probes were performed 1D using the TEM-FAST. For visualization and interpretation of the geophysical models and the data of the subsurface surveys, they were integrated with high resolution aerial image.
João Duarte; A. Pina; M. Cunha; Fernando Figueiredo. Geophysics in the Prospecting Hydrogeological of Santiago. 24th European Meeting of Environmental and Engineering Geophysics 2018, 1 .
AMA StyleJoão Duarte, A. Pina, M. Cunha, Fernando Figueiredo. Geophysics in the Prospecting Hydrogeological of Santiago. 24th European Meeting of Environmental and Engineering Geophysics. 2018; ():1.
Chicago/Turabian StyleJoão Duarte; A. Pina; M. Cunha; Fernando Figueiredo. 2018. "Geophysics in the Prospecting Hydrogeological of Santiago." 24th European Meeting of Environmental and Engineering Geophysics , no. : 1.