This paper aims at reporting on the most recent outcomes of an innovative potential laboratory test (IRTest), which allows the indirect estimation of porosity of intact rock specimens through ...InfraRed Thermography. Starting from the positive preliminary available literature data, proving the existence of a relation between the cooling of previously heated rocks and their porosity, in this paper five different rock types, with a variable porosity grade (ranging from <10% to >40%), were tested according to an innovative procedure. After an initial heating phase, their cooling was monitored through InfraRed Thermography and the Cooling Rate Index (CRI) was calculated to describe their attitude during the heat dissipation. Such index proved well correlated to the porosity of tested specimens, which was preliminary calculated according to international standards. Achieved outcomes demonstrate that the cooling trend of rocks within the first 10 min of test (CRI10) represents a reliable index for the indirect quantification of such important physical parameter, thus proposing a wide range of ideas for further scientific researches aiming at implementing and validating the scientific casuistry on this new topic.
•We present the laboratory investigation of basaltic rocks.•We investigated rock specimens through InfraRed Thermography.•InfraRed Thermography allows recognizing the most persistent voids.•The ...mechanical attitude of rocks from Mount Etna is affected by a great variability.
The laboratory characterization of basaltic rocks from Mount Etna (eastern Sicily) is presented herein, with the aim of investigating on the mechanical attitude of such rock, widely employed as construction and decorative material. The analysis was carried out following both traditional and innovative approaches, through laboratory tests and InfraRed Thermography prospecting. In particular, the rocks underwent a geotechnical characterization aimed at assessing their main physical and mechanical properties, while Thermography was employed for the infrared analysis of specimens, to highlight differences and peculiar features related to their structure. Achieved results show that such rock type, renowned worldwide for its importance, cannot be represented by standard engineering geological parameters, because its properties are affected by a great statistical variability, which could condition its use as construction or decorative material.
Furthermore, the innovative methodological approach followed herein proved very worthwhile in the laboratory characterization of a rock and lays the foundations for future studies focusing on the utility of new technologies in this field.
Preliminary results on a new test for the indirect assessment of porosity through infrared thermography are presented. The study of the cooling behavior of rock samples in laboratory, through the ...analysis of thermograms, proved an innovative tool for the estimation of such an important property, which is one of the main features affecting the mechanical behavior of rocks. A detailed experimentation was performed on artificially heated volcanic rock samples characterized by different porosity values. The cooling trend was described both graphically and numerically, with the help of cooling curves and Cooling Rate Index. The latter, which proved strictly linked to porosity, was employed to find reliable equations for its indirect estimation. Simple and multiple regression analyses returned satisfactory outcomes, highlighting the great match between predicted and measured porosity values, thus confirming the goodness of the proposed model. This study brings a novelty in rock mechanics, laying the foundation for future researches aimed at refining achieved results for the validation of the model in a larger scale.
A detailed laboratory characterization of limestones employed for the reconstruction of Saint Nicholas Cathedral, a UNESCO World Heritage monument in southeastern Sicily, is presented herein with the ...purpose of achieving a complete knowledge on the behavior of such rocks under stress, whose engineering geological aspect had not been investigated before for scientific purposes. Specimens were sampled at three sites, where this rock is quarried from two lithofacies of the same geological formation, and are similar to other limestone varieties quarried worldwide and employed as construction material. Although slight differences between the samples occur at a macroscopic scale, geotechnical tests highlighted relevant differences from the physical and mechanical points of view. In order to look for one or more factors responsible of such dissimilarities, a statistical analysis was carried out and interesting outcomes were achieved with the help of a microscopic analysis of the specimens. Moreover, attention was paid on the modes of failure of tested specimens under compression, whose attitude was described and correlated to selected properties of the rock. Results have both a practical implication, because of the employment of this rock type as engineering material worldwide, and a scientific relevance, due to the peculiar behavior that such rock offered under stress.
•We study the limestones used for the reconstruction of a World Heritage monument.•Scientific results are focused on specimens belonging the Palazzolo formation.•Uniaxial and triaxial compression tests were performed on cylindrical specimens.•The failure pattern observed was related to the rock texture.•Interesting statistical relations were achieved by correlating resulting data.
The island of Sicily has a long standing tradition in citrus growing. We evaluated the sustainability of orange and lemon orchards, under organic and conventional farming, using an energy, ...environmental and economic analysis of the whole production cycle by using a life cycle assessment approach. These orchard systems differ only in terms of a few of the inputs used and the duration of the various agricultural operations. The quantity of energy consumption in the production cycle was calculated by multiplying the quantity of inputs used by the energy conversion factors drawn from the literature. The production costs were calculated considering all internal costs, including equipment, materials, wages, and costs of working capital. The performance of the two systems (organic and conventional), was compared over a period of fifty years. The results, based on unit surface area (ha) production, prove the stronger sustainability of the organic over the conventional system, both in terms of energy consumption and environmental impact, especially for lemons. The sustainability of organic systems is mainly due to the use of environmentally friendly crop inputs (fertilizers, not use of synthetic products, etc.). In terms of production costs, the conventional management systems were more expensive, and both systems were heavily influenced by wages. In terms of kg of final product, the organic production system showed better environmental and energy performances.
•We compared the sustainability of organic and conventional citrus orchards.•An energy, environmental, economic analysis of the production cycle was performed.•Organic farming showed a higher sustainability than the conventional one.•Organic systems were more sustainable because of lower chemical input.
InfraRed Thermography has been tested herein for the study of the fracturing condition of intensely jointed rock masses, in order to find out what kind of information can be assessed. Although this ...technique is widely used in several scientific fields, its direct application for rock mechanics purposes is still under development. In this paper, thermal imaging campaigns, carried out in different climatic conditions, are described. A Cooling Rate Index, related to how fractured rock masses behave during the heat transfer towards the external environment, is proposed. Such an index has been related to the degree of fracturing of the rock masses, in order to find a relationship among thermal behavior and the main quantitative fracturing indexes. Results return interesting matches between some geostructural features and thermal outputs, demonstrating the reliability of the application of such methodology to bare rock masses. Moreover, new experimental considerations are proposed, laying the foundations for future studies aimed to further validate the InfraRed Thermography as an effective remote survey technique.
•We tested the application of InfraRed Thermography for the study of rock masses.•We performed thermal imaging campaigns at fractured rock slopes.•The thermal behavior of rock masses has been studied.•The Cooling Rate Index is proposed for a correlation with geostructural features.
With the establishment of ceilometer networks by national weather services, a discussion commenced to which extent these simple backscatter lidars can be used for aerosol research. Though primarily ...designed for the detection of clouds it was shown that at least observations of the vertical structure of the boundary layer might be possible. However, an assessment of the potential of ceilometers for the quantitative retrieval of aerosol properties is still missing. In this paper we discuss different retrieval methods to derive the aerosol backscatter coefficient βp, with special focus on the calibration of the ceilometers. Different options based on forward and backward integration methods are compared with respect to their accuracy and applicability. It is shown that advanced lidar systems such as those being operated in the framework of the European Aerosol Research Lidar Network (EARLINET) are excellent tools for the calibration, and thus βp retrievals based on forward integration can readily be implemented and used for real-time applications. Furthermore, we discuss uncertainties introduced by incomplete overlap, the unknown lidar ratio, and water vapor absorption. The latter is relevant for the very large number of ceilometers operating in the spectral range around λ = 905–910 nm. The accuracy of the retrieved βp mainly depends on the accuracy of the calibration and the long-term stability of the ceilometer. Under favorable conditions, a relative error of βp on the order of 10% seems feasible. In the case of water vapor absorption, corrections assuming a realistic water vapor distribution and laser spectrum are indispensable; otherwise errors on the order of 20% could occur. From case studies it is shown that ceilometers can be used for the reliable detection of elevated aerosol layers below 5 km, and can contribute to the validation of chemistry transport models, e.g., the height of the boundary layer. However, the exploitation of ceilometer measurements is still in its infancy, so more studies are urgently needed to consolidate the present state of knowledge, which is based on a limited number of case studies.
•A complete characterization of a calcarenite from Sabucina (Sicily) has been provided.•Changes in microtextural and microstructural due to salt weathering have been studied.•Variations of ...physical-mechanical parameters due to salt weathering have been studied.•Correlation between degradation mechanism and engineering parameters has been obtained.•The obtained results are useful in planning conservative action on buildings.
The main aim of this research is to highlight the effects of salts crystallization on physical and mechanical proprieties of natural building stones in consideration of petrographic and porosimetric features. In order to achieve the goals of this work, numerous standard tests have been performed on both fresh and weathered samples of a Sicilian calcarenite named Sabucina stone, widely used as building and replace stones in local Cultural Heritages. The obtained results allow to establish interesting correlation between the intensity of degradation processes and the studied parameters; in fact, a modification of the mechanical behavior has been observed in concomitance with a change in the degradation mechanism occurred in the pore network, highlighting the influence of microtextural and microstructural modifications due to the salt crystallization in the engineering properties of the studied rock.
The migration of a groundwater contaminant plume consisting of light nonaqueous phase liquids (LNAPLs) along the Ionian coastline of Sicily, Italy, has been reported to follow a trajectory that is ...inconsistent with the regional hydraulic gradient. The influence of several faults affecting the fractured carbonate bedrock aquifer, and groundwater abstraction from a well, were hypothesized to be responsible for the anomalous trajectory of the contaminant plume. A conceptual hydrogeological model was developed for the study area that incorporated structural information derived from geophysical surveys and the mapping of fractures in bedrock outcrops. This conceptual model was incorporated into numerical groundwater flow and solute transport models to simulate the groundwater transport of the light nonaqueous phase liquids. Four model scenarios representing different levels of complexity were tested to assess the relative influence of geological heterogeneity and groundwater abstraction on the migration of the contaminant plume. Results show that underground major discontinuity systems, invoking the presence of the faults in the model domain accounted for the observed migration of the contaminant plume, act as conduits for groundwater flow. Conversely, groundwater abstraction from a well was found to result in relatively minor, localized impacts to the migration of the contamination plume. This study demonstrates the importance of incorporating geological heterogeneity into groundwater modelling and environmental risk assessments associated with the storage of LNAPLs.
A comprehensive laboratory characterization of volcanic rocks belonging to the 1669 lava flow of Mount Etna, recognized as one of the largest and most catastrophic event ever occurred, is presented ...herein with the aim of investigating on their peculiar mechanical attitude.
The multi-disciplinary approach proposed herein pointed out that although originated by the same eruptive event, 1669 trachybasaltic lavas are characterized by relevant differences in porosity and rock fabric, from both the qualitative and quantitative points of view. This is an interesting aspect, because such rocks are quarried for the production of high quality material to be employed for engineering geological purposes even in the “Val di Noto” UNESCO World Heritage site. In this perspective, their detailed characterization is an essential practice, even preparatory for the engineering geological use.
To this purpose, this paper provides a focus on the laboratory investigation of these rocks, which according to three different porosity classes, underwent petrographic, physical, mechanical and seismic analyses. Interesting statistical correlations allowed understanding the mutual dependence of the main engineering geological parameters, highlighting how porosity, through both vesicles and microcracks, plays a leading role from the engineering geological point of view. Achieved results provide a scientific casuistry on this topic and are a reliable reference for studies on similar rock types worldwide, since lavas are among the most used rock materials in the engineering geological practice.
•A close relation affects physico-mechanical and fabric features of 1669 Etnean lavas.•Although belonging to the same lava flow 1669 rocks show different porosity grades.•Voids and microcracks control the mechanical behavior of tested rocks.•Microfractures develop either within the rock matrix and within some phenocrysts.
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