2,060 research outputs found
Portable XRF: a tool for the study of corundum gems
No full textThe inspection of aspects as origin of gems is a key information not only in gemological field,
but also in Cultural Heritage studies, for the correct classification and evaluation of precious
artifacts. Due to the great value of gems and jewels, the studies on gems require the application of
non-invasive and non-destructive methods (Vandenabeele et al. 2014). Among them, portable
spectroscopic techniques (such as Raman and X-ray fluorescence) have been demonstrated as
powerful tools in investigating mineralogical identity and chemistry of gemstones (Barone et al.
2015, Barone et al. 2016a, Barone et al.2016b, Lauwers et al. 2016, Petrovà et al. 2012). In
particular, trace-element chemistry can provide a fingerprint of gems, for the determination of their
origin (e.g.: natural vs. synthetic) and provenance (e.g.: geographical areas) (Rossman 2009). In
this study, portable XRF spectroscopy has been applied to test the potential of the technique for the
origin determination of corundum gems (rubies and sapphires). Effectively, on the basis of the
obtained data, natural and synthetic rubies and sapphire have been distinguished; however, the
combined use of complementary portable spectroscopy techniques (i.e.: Raman spectroscopy) has
to be recommended for the correct interpretation of chemical results
Visualization and quantification of weathering effects and water uptake processes in natural building stones by using neutron imaging
No full textCalcarenites are the most widely used natural building stones in Sicily. They are frequently subjected to very intense degradation due to salt growth [1, 2]. This process is often responsible for strong modifications of their pore network [3] and has a great influence in the mechanical properties and the durability of materials [4]. In addition, as water transport has a key role in the degradation processes, the quantification and visualization of fluidflow into the pore network of degraded stones represent useful tools in understanding the weathering process.
Classical approaches are usually performed by applying laboratory test routines for the determination of water absorption parameters. However, they cannot provide a description of the local distribution of water inside the stone. In this framework, neutron imaging has been demonstrated as a powerful technique for the visualization and quantification of the water distribution in partially saturated porous media [5]. Moreover, the possibility to perform dynamic measurements allowed monitoring the water uptake as function of time and to explore the complex processes involved in fluid transport [6-8].
In this study neutron radiography has been used with the aim of: a) monitoring and visualizing the fluidflow patterns inside porous structure of a local calcarenite widely used as building and replace stone in several Cultural Heritages, namely Sabucina Stone; b) quantifying the water distribution as function of time, in order to understand the effects of weathering on the behavior of the stone against water. In detail, samples of un-weathered and artificially weathered[9] Sabucina Stone have been scanned with neutron imaging technique at the IMAGINE beam line located at the Laboratoire Léon Brillouin (CEA/CNRS) in Saclay (France). Capillary water uptake has been monitored over time in samples subjected to different salt crystallization cycles.
Beside the qualitative data acquired from the raw neutron images (Figure 1(a)), quantitative results have been obtained thanks to the image processing of the radiographs (Figure 1(b)) [10]. First of all, the evolution of the wetting front position over time has been observed and the penetration coefficient has been determined. The results demonstrated that changes in the hydric properties of the stone occurred with the intensification of the degradation process. Even if a good agreement with standard capillary absorption test has been obtained [11], the non-perfect linearity of capillary uptake process has been evaluated, due to the evidence of preferential flow paths. Therefore, neutron images have been processed in order to obtain quantitative water distributions as function of time. The contour plot of the water content value highlighted that degraded stones absorbed greater volumes of water than the un-weathered ones, due to the strong modification of their pore structure. Moreover, in weathered samples the quicker and deeper vertical spreading of the water was associated with an intense horizontal migration through pores enlarged by the degradation mechanisms. Finally, side effects, probably due to the more intense action of the degradation process close to the sample surface, were evidenced, determining different capillarity absorption properties for the inner and surface regions. In conclusion, neutron radiography has allowed a better understanding of the deterioration mechanisms affecting physical properties of building stones, supplying relevant data for planning powerfully actions to improve their durability. References:
[1] M. Steiger, S. Asmussen. Geochimica et Cosmochimica Acta2008; 72: 4291.
[2] G.W. Scherer. Cement and Concrete Research1999; 29:1347.
[3]S. Raneri, V. Cnudde, T. De Kock, H. Derluyn, G. Barone, P. Mazzoleni. Europen Journal of Mineralogy2015; 27: 279
[4] S. Yu, C.T. Oguchi. Engineering Geology2010; 115: 226.
[5] E. Perfect, C.L.Cheng, M. Kanga, M.Z. Bilheux, J.M. Lamanna, M.J. Gragg, D.M. Wright. Earth-Science Reviews2014; 129:120.
[6] G. Barone G, V. Crupi, F. Longo, D. Majolino, P. Mazzoleni, S. Raneri, J. Teixeira, V. Venuti. Journal Instrumentation2014; 9: C05024.
[7] V. Cnudde, M. Dierick, J. Vlassenbroeck, B. Masschaele, E. Lehmann, P. Jacob, L. Van Hoorebeke. Nucl.Instrum. Methods Phys. Res. B 2008; 266:155.
[8] M. Dierick, J. Vlassenbroeck, B. Masschaele, V. Cnudde, L. van Hoorebeke, A. Hillenbach. Nucl.Instrum.Methods Phys. Res. A2005; 542:296.
[9] UNI EN 12370, Natural stones test methods: Determination of resistance to salt crystallisation, UNI ed., Milano, 2001.
[10] F.H. Kim, D. Penumadu, D.S. Hussey. J. Geotech. Geoenviron. Eng.2012; 138:147.G.
[11] G. Barone, P. Mazzoleni, G. Pappalardo, S. Raneri. Construction and Building Materials2015; 95:355
Non-destructive chemical and mineralogical analysis of Etruscan Painted Architectural Slabs
No full textIn 2016 a huge amount of archeological materials, mainly painted architectural slabs, were retrieved from the Glyptotek of Copenhagen and the private collection of R. Syme thanks to an action of the Comando dei Carabinieri della Tutela Patrimonio Culturale. According to the analogies in style and the typology part of these materials are supposed to come from the UNESCO archeological site of Cerveteri, important Etruscan center to which belong a large amount of materials dated back to the second half of the VI century B.C. Due to the importance of these precious terracotta, all the specimens were investigated by means of non-destructive portable XRF and Raman instrumentations. Furthermore, XRD and micro-Raman spectroscopy were carried out on micro-samples picked up by the restorers of Superintendence. The research aims are: i) the individuation of the main chemical and mineralogical composition of the pottery bulk; 2) the characterization of the painted layers. The data obtained were compared with those carried out on similar fragments certainly attributed to Cerveteri and Veio. Furthermore, the use of pigments was related to the colors used in the archaic period for the Tarquinia [1] wall painted tombs.
The slabs, all with a creamy engobe, show human and animal figures in geometrical frameworks. Combined Raman and XRF analysis allowed us to distinguish different pigments and to suggest some considerations about their authentication.
[1] G. Barone, P. Mazzoleni, A. Cecchini, A. Russo. 2018. In situ Raman and pXRF spectroscopic study on the wall paintings of Etruscan Tarquinia tombs, Dyes and Pigments, 150, 390-40
Exploring the coroplasts “techne” in Greek architectural terracottas: an archaeometric approach
No full textArchitectural terracottas represent a key element in the history of ancient Greek architecture; morphological variations, technical features and decorative motifs occur over the time, especially during the archaic period (Winter, 1993). In the western Greek colonies, different styles of roof revetment and decoration are known; among them, the so called “Siceliote system” and “Selinus system”. The numerous fine architectural terracottas fragments found in the South-Eastern area of Sicily during the archeological excavations strongly suggest the existence of important local workshops. However, even if the archaeologists have extensively described this class of artifacts, the scientific debate about fabrics, raw materials supply, manufacturing technology and decoration systems is currently open. One of the most interesting problem concerns the frequent presence of coarse-grained volcanic inclusions in the ceramic paste; this feature seems to be peculiar of many Sicilian architectural terracottas, as testified by several fragments found at Gela, Siracusa and Lentini. Worth of note is that this feature is observable also in area where volcanic rocks don’t outcrop suggesting that it is probably due to technological reasons. Another significant aspect regards the painted decoration technique of the revetments (i.e. firing phases, pigments, etc.) (Rescigno & Sampaolo, 2005). Even if preliminary studies on some Geloan architectural terracottas specimens have provided really promising results (Barone et al., 2015), the drawing of a complete scenario on the manufacturing features of the regional Sicilian roof revetments needs further investigations.
In order to achieve this goal, we have studied numerous decorated sima and geison fragments and acroteria specimens coming from some of the most important temples of Siracusa and Lentini. Materials have been analysed from petrographic, mineralogical (XRD) and chemical (XRF) point of view. Additionally, in-deep analyses have been carried out on volcanic inclusions, taking advantages from a methodological routine based on clinopyroxenes chemical composition obtained through Scanning Electron Microscopy coupled with Energy-Dispersive Spectrometry (SEM- EDS) measurements (Barone et al., 2010). Finally, an analytical characterization of the polychrome decoration of surfaces has been obtained by performing SEM-EDS and micro-Raman spectroscopy measurements.
All the analytical data have been therefore discussed and compared with the results obtained on Geolan materials in the light of the archaeological interpretations, providing a detailed overview on the local tradition of architectural terracottas production.
References
Barone, G., Belfiore, C.M., Mazzoleni, P., Pezzino, A. &Viccaro, M. (2010): A volcanic temper based approach for provenance studies of archaeological ceramics from Southern Italy. Journal of Archaeological Science, 37, 713-726
Barone, G., Mazzoleni, P., Raneri, S., Spagnolo, G. &Santostefano, A. (2015): Coroplastic art in Sicily: an investigation on provenance and manufacturing technology of the Greek architectural terracottasfrom Gela (Italy), 13th European Meeting on Ancient Ceramics, EMAC2015, Athen, September 24-26, 2015.
Rescigno, C. & Sampaolo, V. (2005): Appunti sull’impiego del colore sulle terrecottearchitettoniche capuane. Mediterranea : quaderni annuali dell'Istituto di studi sulle civiltà italiche e del Mediterraneo antico del Consiglio nazionale delle ricerche, già Quaderni di archeologia etrusco-italica, II, 133-164.
Winter, N.A. (1993): Greek Architectural Terracottas: From the Prehistoric to the End of the Archaic Period, Clarendon Press, 360 p
Evaluation of the technological features of late roman cooking ware classes from Akrai (Syracuse, Sicily)
No full textIn this work, a provenance and technological investigation on cooking-ware potteries from the ancient
Greek -Roman town of Akrai (Palazzolo Acreide, Syracuse, Sicily) has proposed. A multi-methodological
approach have been used to study the manufacture quality of analysed materials; in detail, petrograp
hic, mineralogical, spectroscopic, chemical, porosimetric and micro-morphological analyses have been
applied. The study providesfundamental contribute in archeological issues related to circulation in Sicily of cooking
-ware productions during Late Roman Age; in fact, the obtained results allow to recognize in the site
the presence of different well-known cooking-ware Roman productions, highlighting interesting questions
about the technological and manufacture properties of this class of materials
Application of fractal models to ancient ceramics: structural and technological aspects
No full textIn this work we present the result of a research finalized to put forth new elements about technology of the pottery production in the Middle Bronze Age in Sicily (15th-13th century BC) by using fractal models. Recently, this approach successfully applied to study Hellenistic-Roman pottery from Syracuse (Sicily, Southern Italy) [Barbera, 2013], evidenced the efficiency of fractal geometry in description of the meso and micro scale structure of the ceramics in order to obtain technological informations.
The lack of archaeometric data about the pottery production of Prehistoric Sicilyrepresents the main problem currently conditioning future advances in archaeological research.
The characterization of ancient ceramics is complex due to the heterogeneity of the materials on different scales and to the coexistence of amorphous and crystalline phase in the same sample. For these reason, a complete structural characterization could be achieved through investigation at different scales of observation.
A group of Middle Bronze Age pottery from the cave site of Grotte di Marineo (Licodia Eubea, Catania, Italy) was selected, as case study. The sampled potteries belong to the three chronological sub-phases in which the local Bronze Age can be divided. The goal of this study is to acquireinformation about the evolution of technological aspects of pottery manufacture over the time. In particular we investigate the firing temperature and technological production processes.
The mesoscopic structure of the samples has been investigated through small angle neutron scattering (SANS), in order to obtain information about the size and surface characteristics of the aggregates of minerals and voids. These parameters are reported in literature dependent to the firing technology used in the production process [Botti, 2006]. All the obtained results were interpreted in the framework of fractal model. Data have been also compared with the mesoscopic parameters and fractal dimension extracted for clay sediments typical of the Sicilian area and fired under controlled conditions [Barone, 2009]. The observed agreement between the features of reference and archeological samples allowed us to estimate the maximum firing temperature of the latter. Barbera et al, J Arch Sci, 40: 983–991, 2013.
Barone et al., J Appl Phys, 106: 054904, 2009.
Botti et al., J. Arch Sci, 33: 307-319, 2006
The relationship between Impulse Control Disorders and cognitive dysfunctions in Parkinson's Disease: A meta-analysis
No full textImpulse Control Disorders (ICD) are associated with impairment in cognitive flexibility and cortical inhibition. In Parkinson's Disease (PD) the relationship between ICD and cognitive dysfunctions is still unclear: some studies found different cognitive profiles between Parkinsonians with and without ICD, whereas others did not. Moreover, findings from studies on ICD in PD are conflicting on which cognitive function is altered. A meta-analysis of 34 studies was performed to shed light on relationship between ICD and cognitive dysfunctions and to reveal the cognitive function compromised in Parkinsonians with ICD. Data were analysed in global cognitive functioning, memory, executive functions, attention/working memory, language, and visuospatial functions. Significant relationship between ICD and dysfunction of abstraction ability/concept formation, set-shifting, visuospatial/constructional abilities and decision-making was found. These findings suggested that people affected by PD with specific frontal dysfunctions are more vulnerable to develop ICD when they take antiparkinsonian drug. Evaluation of specific cognitive functions in routine clinical practice might help to detect those people with PD susceptible to ICD before treating them with antiparkinsonian drugs
Investigating environmentally sustainable consumption: A diary study of home-based consumption behaviors
No full textThis study analyzes three environmentally sustainable household consumption behaviors (optimizing the use of domestic water, minimizing food waste, and mini- mizing plastic packaging usage) through the model of goal-directed behavior. The findings show that attitudes, subjective norms, perceived behavioral control, antici- pated emotions, and habits are all significant predictors of the desire to adopt sus- tainable consumption behaviors, which directly fosters the intention to adopt these behaviors. Intention–behavior links were unique for each behavior; minimizing plastic packaging usage was the most difficult behavior to implement. This study offers use- ful insights into people's sustainable consumption goals and their intentions to adopt responsible consumption behaviors. A generalizable model of environmentally sus- tainable household behaviors that considers the three behaviors simultaneously is presented. This study suggests that business and policy strategies that could success- fully promote sustainability in the household might proceed by, for example, empow- ering consumers or changing their habits
"The road to food waste is paved with good intentions": when consumers' goals inhibit the minimization of household food waste
No full textDespite their generally negative attitude toward food waste, consumers often pursue goals that can inhibit their intention to reduce food waste. Identifying these goals that inhibit consumers’ intention to reduce food waste is essential for the development of successful public policy and retail approaches designed to curb or reduce household food waste. First, we conducted semi-structured qualitative interviews (N=110) aimed at identifying the consumers’ main goals conflicting with their attitude toward food waste. Four main conflicts emerged as relevant in consumers’ minds: being a good provider, concerns over possible health risks, healthy diet, and saving money. We then ran a quantitative study on adult consumers (N=163), aimed at testing an extended Theory of Planned Behavior (TPB) model with the inclusion of such conflicting goals as additional predictors of the consumers’ intention to reduce food waste. Both studies were conducted in Italy. Results show that three out of four conflicting goals – being a good provider, concerns over possible health risks, and healthy diet – together with attitude and subjective norms, significantly affect the intention to reduce food waste. In turn, the intention to reduce food waste negatively affects food waste behavior. This study contributes to research on food waste by identifying additional and previously neglected predictors of the intention to reduce food waste. In turn, these results provide evidence of the existence of other valuable entry points to use for the design of successful interventions aimed at reducing household food waste
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