Acta IMEKO

Calibration methods for high frequencies: Development and validation

2024-03-18T14:18:38+00:00

The paper presents an introduction of an advanced method for calibration of high-frequency instruments, such as oscilloscopes, frequency counters and function generators that operate at the frequencies between 1 MHz and GHz range. Based on conducted thorough survey of the needs for calibration of high-frequency measurement devices in the region of Southeast Europe, and the identified calibration and measurement capability gap in comparison to the international metrology offer, the Laboratory for Electrical Measurements at Ss. Cyril and Methodius University in Skopje developed new methods, following the general recommendations of the EURAMET cg-7 Calibration Guide. An original approach in the design of the experimental procedure, and a novel data fusion concept for the evaluation of the measurement uncertainty is deployed. The paper also investigates and resolves some challenges of setting up an unbroken measurement traceability chain, and uncertainty estimation for calibration in the domain of high frequencies. The established and accredited calibration capabilities are essential for the region of Southeast Europe, where the metrology facilities for the calibration/testing of high frequency electronic devices are inadequate to meet the conformity assessment needs of the quickly growing automotive supply chain sector, and the needs of other electrical and electronic industries.

Improvement of metrology infrastructure in the area of extreme impedance calibrations

2024-02-07T09:37:57+00:00

The paper describes how the Laboratory for Electrical Measurements at the Ss. Cyril and Methodius University in Skopje, an accredited calibration laboratory, enhanced its calibration and measurement capabilities for extreme values of electrical impedance. This was conducted through development of new calibration methods for instruments that measure extreme electrical resistance and inductance. The paper also explains how these methods were validated to ensure traceability and how the measurement uncertainty in impedance instruments calibration was innovatively estimated, by deploying the data fusion concept to increase the metrology infrastructure capacity. As the testing facilities for electrical quantities in Southeast Europe are not sufficiently developed, and some calibration areas of electrical instruments are not well provided by the existing laboratories, despite the economic and scientific demands, the relevance of this metrology infrastructure upgrade is evident.

Measurement uncertainty evaluation of equivalent roughness in hydraulic pipes

2024-04-16T19:34:23+00:00

This paper addresses the quantification of the dispersion of equivalent roughness values obtained from the experimental study of hydraulic pipes used, for example, in water supply networks. This quantity is mainly used in the determination of the friction factor related to pipe fluid flow. In this context, non-linear and complex mathematical models, such as the Colebrook-White equation, are applied to characterize the equivalent roughness of hydraulic pipes composed of different types of materials. However, knowledge about the measurement uncertainty of the obtained estimates is still reduced, having a direct impact in the conformity assessment of this type of hydraulic component and in the technical comparison between different types of pipes (materials and manufacturers). The paper describes the application of a Monte Carlo method (MCM) in the measurement uncertainty evaluation of equivalent roughness. In addition to presenting the theoretical and experimental background, the paper describes the measurement uncertainty propagation, from the probabilistic formulation of the input quantities up to the output quantity. A numerical example, based on experimental data retrieved from field testing of hydraulic pipes integrated in a large-scale agricultural irrigation network, is shown in the paper, illustrating the suitability, advantages, and limitations of the proposed approach.

Automating flowmeter calibration process: Digital measurements from numerical displays using open-source optical character recognition tools

2024-04-16T19:35:40+00:00

This paper presents a methodology for obtaining digital machine-readable measurements from numerical displays images. The proposed method provides means to digitalize an automate a previously manual and labour-intensive laboratory procedure for flowmeters calibration. The proposed method allows to obtain machine-readable readings from remote numerical displays with available-off-the-shelf hardware and open-source software. By using smartphones for remote image capture and streaming and the Tesseract open-source OCR engine, is possible to leverage the infrastructure’s digital transition, improve procedures efficiency and effectiveness while promoting sustainable actions with cost reductions.

Traceability and measurement uncertainty of non-removable field flowmeters using clamp-on ultrasonic flowmeters as reference

2024-05-01T09:02:47+00:00

This study examines the traceability and measurement uncertainty of in situ hydraulic calibration of flowmeters using clamp-on ultrasonic flowmeters as reference. The procedure compares the equipment readings with the reference ones. Measurement uncertainty evaluation uses Guide to the expression of Uncertainty in Measurement (GUM) formulation, considering the linearity conditions of the mathematical models applied. Experimental values are used to test the procedure and its suitability for actual cases where the expected accuracy needs to be achieved.

Overcoming traceability challenge in air quality measurements by developing reference gas mixtures of CO2 in a typical indoor/outdoor range for future relevant IoT technology applications

2024-05-07T09:27:29+00:00

High-resolution air quality monitoring using inexpensive sensor systems has attracted a lot of attention in the context of smart cities. However, in order to preserve metrological traceability, these systems must be regularly recalibrated. The necessity of quality control, dependability, and traceability of analytical data has received a lot of attention lately. IoT sensors can also be used to monitor the condition of equipment and ensure that it conforms with safety rules, given the rapid advancement of new technologies and their numerous everyday uses. Therefore, the primary motivation for our study endeavour was to provide reference gas mixtures to calibrate those sensors optimally in the future while keeping traceability to SI units, which is an important and demanding duty of gas standard laboratories at NMIs. Given the significance of metrological issues in the current context, the national measurement and calibration centre (SASO-NMCC) developed the methodology for preparing such primary standard gas mixtures (PSMs) through standardized gravimetric method in order to improve measurement capabilities and provide a level of confidence regarding greenhouse gas standards. Compatibility check, as per ISO 6143:2001, for the gas chromatography thermal conductivity detector (GC-TCD) with respect to the gravimetric assigned values with its associated combined uncertainty is also presented for each produced PSM. The relative expanded uncertainty of the carbon dioxide standard mixture, taking into account the contributions from verification analysis by GC-TCD, was less than 0.7 % for the prepared range of (0.00499 ± 0.00006) to (0.1996 ± 0.000424) mol/mol. This is comparable to the average of 0.25 % relative uncertainties presented on international standards mixtures.

Spatial evaluation of the museum experience in converted heritage: the case of the National Bardo Museum in Tunisia

2024-05-10T12:12:58+00:00

This paper addresses the evaluation of the conversion of the Bardo museum in Tunisia. Indeed, buildings converted into exhibition spaces rarely adapt perfectly to their new functions. Following this perspective, we propose to answer two major questions: How can we objectively evaluate the conversion of the Bardo museum, which was originally built as a seat of power and residence purposes and converted into an exhibition space? What criteria can be used to evaluate it while respecting international charters?

Through the spatial analysis carried out on the subject, our approach allowed us to highlight the spatial properties of the museum using the Depthmap simulation based on Spatial Syntax, a questionnaire, and the observation technique of Wayfinding. We have developed an objective analysis tool to evaluate the reliability of the conversion and the challenge of transforming a traditional and historical space through its architecture into a space that will fulfil a new 'function'. Hence, we deduced through this method that this conversion is a partial success.

Green synthesis and characterization of titanium dioxide nanoparticles and their photocatalytic activity

2024-04-12T08:51:34+00:00

In this study, we compared two low-temperature synthesis procedures for the large-scale production of titania nanoparticles (NPs). The first takes place in an aqueous medium with an acidic environment, by using a triblock polymer surfactant (Pluronic 123). The second involves a polycondensation reaction of alkoxide precursors at 70 °C in a water-in-oil (W/O) microemulsion with a volume ratio of 1:1, using cetylpyridinium bromide (CPB) as a cationic surfactant. The morphological and structural characterization of the samples was carried out through Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The photoactivity of the nanostructured titania was evaluated by measuring the photodegradation of Methylene Blue (MB). The solvent-free synthetic approach provided spherical titania nanoparticles mainly constituted by rutile crystallites with a very good synthetic yield. However, the photodegradation rate of MB for such titania nanoparticles ranges from 30 % to 40 %, after 1h under solar irradiation. Conversely, titania nanoparticles obtained through microemulsion synthesis show a photodegradation rate of more than 90 % comparable to titania P25. This high-yield synthesis leads to the formation of TiO₂ nanoparticles characterized by small crystallite aggregates (rutile and anatase).

Geodatabase, metric reconstruction and a GIS platform of historical-archaeological sites in Aquino

2024-02-27T15:48:00+00:00

This paper presents the contents of a geodatabase developed from the outcomes of survey operations carried out, in several stages since 2015, within the archaeological context of the Roman city of Aquinum, in southern Lazio. The proposed geodatabase integrates traditional topographic surveying techniques with total station, GPS and GNSS geodetic receivers with photogrammetric surveys and terrestrial laser-scanner (TLS) measurements, including the realization of HBIM (Historical Building Information Modeling) models, to investigate some specific historical-archaeological evidence useful to understand the Roman and medieval urban structure of the city. The processing and management of the metric and information datasets were entrusted to a GIS platform, implemented in the opensource Quantum-GIS software, to optimize the flowchart of the acquisition/processing process and to realize an intra-site Web-GIS useful for the visualization and dissemination of the results. The methodological-operational approach applied in the research activities highlights the fundamental contribution that the technological innovations of geomatics can provide for the construction of elaborate knowledge concerning cultural heritage, also becoming the base for the elaboration of more complex and detailed analyses. In this case, for example, the HBIM digital model of the Church of Santa Maria of Libera was also used for an in-depth study in the field of structural engineering, as input to model the masonry vaults of the aisles of the church and assess their structural safety through the analysis methodology denominated "Thrust Network Analysis (TNA)." In addition, the high-precision 3D models developed from detailed photogrammetric measurements of the archaeological fragments and human remains found in the excavation areas made it possible to create interesting "visual digital products" that are immediately understandable even for non-experts, and thus particularly useful for wide-ranging knowledge dissemination.

Artificial aging of monoazo and isoindoline yellow pigments

2024-04-08T15:42:17+00:00

UV- and humidity-related aging effects on two yellow synthetic organic pigments, known for their good lightfastness, were investigated: Pigment Yellow 1 (PY 1, Monoazo) and Pigment Yellow 139 (PY 139, Isoindoline). The work considers the reactivity of these pigments, as individual pigments, in combination with linseed oil, and in presence of highly reactive inorganic white pigments: basic lead carbonate, titanium dioxide, and zinc oxide. Accelerated aging was induced via UV irradiation and high humidity rate in a custom-built chamber using both simple and bilayer paint mock-ups to simulate the technique of overlaying films in paintings. After aging, physicochemical variations were analysed using colorimetry, Fourier-transform infrared spectroscopy, Raman spectroscopy, and photoluminescence spectroscopy. The results show that the accelerated aging induces a greater colour change in monoazo yellow pigment than in isoindoline one when in powder form. Conversely, when oil is present in the samples as binder, the colour variations are similar for both samples suggesting that the large part of the chemical/physical changes occur in the organic binder. For the bilayer systems, photoluminescence spectroscopy suggests that the substrates can induce a larger drying activity on the binder and could follow the contribution of fluorescence in the variation of the perceived colour.

IAEA fostering of the development and applications of nuclear analytical techniques for Heritage Science

2024-02-22T17:54:02+00:00

The IAEA Physics Section is strongly involved in the development and utilization of accelerator-based analytical techniques, which are powerful tools for the characterization of cultural and natural heritage objects and materials. Various activities are carried out with the purpose to build capacity, strengthen capabilities, transfer knowledge and foster networking in the field of heritage science. In addition, access to different X-ray fluorescence spectrometers and other analytical techniques is provided at the Nuclear Science and Instrumentation Laboratory (part of the IAEA Physics Section), and access to ion beam accelerators and synchrotron light is facilitated thanks to collaborations with Ruđer Bošković Institute (RBI) in Croatia and the Elettra Sincrotrone facility in Italy, respectively. Member States are also supported on their Research and Development programmes, as well as through the technical cooperation projects. This paper aims to provide a broad overview about how the IAEA Physics Section is engaged in the field of heritage science, promoting the safe, reliable, and effective use of ion beam, X-ray and neutron-based techniques for the characterization and preservation of cultural and natural heritage through its global networks and partners.

Characterization of multi-layered wall paintings from a Roman domus in Santa Maria Capua Vetere

2024-02-27T15:07:36+00:00

This paper regards the preliminary characterization of wall paintings sampled in a Roman domus located in the city of Santa Maria Capua Vetere. Despite its history and archaeological remains, there is a lack of scientific studies on Roman materials and techniques adopted in this site. Samples were taken from different walls of the villa. Pigments, binders, and mortars were analyzed by optical and electronic microscopies, vibrational spectroscopies including Fourier transform infrared and micro-Raman imaging, and mass-spectrometry coupled to gas and liquid chromatography. Altogether, the multi-layers preparation, the rich pigments palette (both natural and synthetic ones) and the variety of the organic ligands used (terpenic resins or animal glue) support the hypothesis of a very wealthy owner. The absence of calcite in the pictorial layer and the presence of organic binders clearly indicates an a secco technique.

Study and analysis of National Museum of Ras Al Khaimah collection for future generations accessibility

2024-04-29T16:07:43+00:00

The National Museum of Ras Al Khaimah reflects an eventful history, displaying a rich diversity of traditional architecture. Today, the 'Late Fort’ exhibits historical, ethnographical, and archaeological material relating to the emirate of Ras Al Khaimah and provides an interesting insight into the history and traditions of this area.

The formulation of history through the study and preservation of the museum collection is a dynamic and collaborative process that applies a multidisciplinary approach, ethical considerations, and a commitment to sharing the richness of human history with current and future generations. The research focuses on and sheds light on the role of technology in studying, investigating, and preserving collections, which can extract information that formulates their history. Different cases here represent different time periods: the Daggers, two cases of the Khanjar/dagger, specifically of the Jambiya type, herbarium collections, and pottery from the National Museum of Ras Al Khaimah are valuable resources and crucial evidence for formulating and understanding the history, culture, and for research, education, and inspiration when studying and preserving it. The research offers different methodologies used to approach the three cases. the study of daggers shows that examination prior to treatment can help to understand the historical significance of the objects and their technology. the digitization of the herbarium, allow data sharing of images and make them accessible to botanists and others around the world. two potteries from a modern excavation, has being subjected to different.

analyses if the sediment found inside them. By adopting integrated study and preservation approaches, using technology and the correct methodology, we can extract more information, extend the lifespan of collections, and make them more accessible and sustainable.

Experimental characterization of a novel combined composite reinforced mortar - fibre Bragg grating technology for the retrofit and control of existing structures

2024-05-19T14:45:40+00:00

This article investigates the potential of a novel integrated system for the strengthening and monitoring of existing structures. The proposed technology combines Composite Reinforced Mortar (CRM) reinforcements and Fibre Bragg Grating (FBG) sensors and is named as CRM-FBG. Direct tensile tests were conducted as the first step of prototype development and were aimed at evaluating the performance and feasibility of the CRM-FBG system. Measurements provided by FBG sensors were compared to Digital Image Correlation data. The outcomes of the laboratory experiments showed the reliability of the proposed technology, with interesting prospective applications for the retrofit and structural health monitoring of the built heritage.

Diagnostic investigation of the wall paints conservative state in a hypogeal room of the archaeological park of Baia (Italy)

2024-03-07T14:23:34+00:00

The present study investigated the correlation between the degradation processes of cultural heritage and the environmental parameters of the semi-confined site that houses it. The latter is a semi-underground room (nymphaeum) found in the Archaeological Park of Baia (Italy) dating back to the third century; it is decorated with marine motifs and painted with frescos techniques from the same period. Relative humidity and temperature were hourly registered, and the collected data were used to derive daily and annual profiles. The effects of microclimate induced degradation were investigated employing various techniques, such as Ion Chromatography for the chemical characterisation of deposits, and Thermography, for the individuation of biological layers. The data obtained showed that the underground environment, partially submerged by rising brackish water, was affected by the presence of biodeteriogens, whose distribution and growth is strongly favoured, above all, by the environmental parameters and by the substrate characteristics. All the data were then cross-referenced to obtain a complete knowledge of the conservation frameworks of the environments, essential to identify the most compatible and effective restoration methodologies to be applied in the conservation of the nymphaeum.

The virtual reconstruction of Cervara di Roma fortress: methods and tools for the dissemination of the past

2024-03-07T14:29:47+00:00

Three-dimensional (3D) technologies play a crucial role in the philological reconstruction of archaeological contexts. The integration of technology and archaeological evidence has made it possible to develop 3D virtual reconstructions, providing valuable insights into the temporal evolution of archaeological sites. This innovation serves as a significant research and analytical resource, enabling the visualisation of possible scenarios related to archaeological contexts that have significantly changed over time. Moreover, understanding these changes, the past and its relevance to the current context could pose a challenge to the general public. This work aims to illustrate a scalable rendering system using open-source Web3D apps and platforms, allowing access to information, 3D models, and descriptions to enhance the experience of artworks.

Sculptures for a tactile fruition: The head of Sant’Elena

2024-03-21T14:10:25+00:00

The creation of physical replicas of statues is not a novel concept; however, it continues to present various aspects worthy of investigation. On one hand, there is the need to optimize digital models for their physical experience while retaining distinctive features. On the other hand, there is the development of a robust pipeline for constructing reliable physical copies concerning morphometrics and materials. Both stages necessitate experimentation and comparisons, allowing for the validation of processes to achieve scientifically accurate results. This article, using the case study of the head of Sant'Elena preserved within the mausoleum of the same name, suggests comparing different processes of physical and digital 3D acquisition and reproduction of the artwork. The goal is to enhance its accessibility for individuals with visual impairments.

Virtual histology based on 3D X-ray microscopy imaging for non-destructive age-at-death estimation of incinerated teeth from the Tophet of Motya (Sicily, 6th century BC)

2024-03-07T14:37:42+00:00

The reconstruction of infant biological history and mortality profiles provides biocultural insights into adulthood morbidity, maternal health, parental caregiving practices, and social dynamics. However, interpreting biological data from cremated infant remains in archaeological contexts can be challenging due to their often poor preservation and potential biases. Tophets, sanctuaries for distinct burial of cremated infant remains present in several Phoenician-Punic colonies in the Mediterranean area, offer an ideal case study. This study presents the first virtual histology performed in X-ray Microscopy-based imaging (XRM) on a sample of crowns of cremated deciduous teeth from the Tophet of Motya (Sicily, 6^th century BC). The observation of the Neonatal Line (NL) in enamel tissue offers important informations on the community demographic profile, age-at-death classes and life-histories of the buried individuals. Results are consistent with previous studies on other human remains found in the main Tophets in Mediterranean basin and highlight the importance of using non-invasive techniques to collect and analyse data that are useful for the interpretation of newborns and infants burial practices.

Smart tools for archaeological survey in different frameworks and contexts: approaches, analysis, results

2024-04-24T12:19:18+00:00

The world of geomatics today provides new tools, smart and low cost, for archaeological survey, from geographical positioning to detailed drawing and graphic documentation of past evidence. These instruments, light and not bulky, interface directly with tablets, iPads or smartphones via intuitive applications and speed up the data collection in the field: archaeological data collection seems not to be a big issue today and 3D survey appears to be accessible even to less experienced archaeologists. We have tested the Trimble Catalyst DA2 smart system for centimetric georeferencing at the Curiae Veteres in Rome (Italy), at the Sun Temple of Niuserra, in Abu Ghurab (Egypt) and inside the ancient site of Eridu in Iraq: it was a good opportunity to check the accuracy of this tool, especially when associated to detailed and close-range survey activities, related to landscape archaeology and stratigraphic excavations. As we will see, if the instrument cannot replace more precise measurement tools still today (such as total station or laser scanner), in the field of georeferencing can be alternative to more expensive and complex GNSS systems, and it proved to be quite effective in systematic archaeological survey of large areas, especially in association with digital aerial photogrammetry made by UAV-UAS.

Radiological characterization of materials used in the Italian heritage buildings

2024-05-02T08:04:18+00:00

Building materials (BMs) can cause significant gamma dose indoors due to their natural radionuclide content. In 2013, the European Directive 59/2013/EURATOM introduced, in annex XIII, a list of types of BMs of interest for the content of gamma-emitting radionuclides among which materials or additives of natural igneous origin, such as granitoids, tuff and lava, are included. These materials have been largely employed for decorative and structural purposes in the course of centuries in the Italian heritage buildings. Aim of this study is to assess the contribute of BMs in terms of alpha exposure. Six samples of different materials, characterized in a previous study by the authors in terms of radiological content by means of a gamma spectrometry, have been analyzed in order to determine the specific exhalation rate of 222Rn, the radon emanation coefficient and excess in indoor radon concentration. Results confirm that BMs of natural igneous origin can play an important role in terms of alpha radiation dose and internal exposure due to the inhalation of the alpha particles emitted.

A multidisciplinary approach for the evaluation of the archaeological heritage of Borbona (Rieti, Italy)

2024-03-10T17:14:45+00:00

The area of Borbona (Rieti, Italy) has been sparsely researched from a historical and archaeological perspective. In order to obtain new data on unexplored areas, a systematic study was carried out combining archaeological explorations, photogrammetric surveys and geophysical prospections. All data was stored in a Geographic Information System, which enabled spatial analysis and the creation of thematic maps. The aim of the research was to discover the unknown territory and trace its origins. The project identified ancient habitats and significant Roman architectural fragments. The research aims to pass on the history and culture of Borbona to future generations and promote a sense of belonging. The protection of historical heritage and archaeologically endangered areas as well as the enhancement and promotion of existing cultural assets are fundamental measures to increase the attractiveness of the land in the present and preserve its identity in the future.

Quality control of 3D printing in bioarchaeology: a case study on dimensional assessment of cranial models

2024-04-17T17:10:20+00:00

In the last few years, 3D printing has gained widespread use in archaeology and cultural heritage fields, from research and conservation to enriching museum experiences. This study focuses on Fused Deposition Modeling (FDM) technology to assess the quality of printed replicas of archaeological human remains. A cranial model was 3D printed (3DP) from Computed Tomography (CT) data of an 8-year-old patient to simulate the remains of an archaeological skull. Eight copies were then printed and subjected to CT scanning to compare them to the original model through an objective measurement method based on image analysis. The proposed method investigates print variability and considers potential sources of error to assess the dimensional compatibility of the model before and after printing. Results showed an increasing error, up to 15 %, with higher levels of model detail. These results are discussed with reference to a metrological approach, highlighting the need for further research into optimizing 3D printing quality control, including through the definition of a standardized protocol to obtain archaeological replicas faithful to the originals.

Towards the definition of Transformation Stratigraphic Unit (TSU) as new section of the extended matrix methodology

2024-03-10T17:39:46+00:00

This study explores the interpretation of degradation and alteration phenomena as stratigraphic units, showing the preliminary results of ongoing research concerning new investigative methods and tools useful to formalize transformative processes on built heritage, in a chronological perspective. Merging conservation sciences with archaeology, the study introduces a new section of the Extended Matrix (EM) method: the Transformation Stratigraphic Unit (TSU). The aim of this work is to assess a new method for documenting and investigating cultural heritage, by generating scientifically reliable reconstructive hypotheses, and by analysing and comparing the mutual interaction of different degenerative phenomena and their relationship. The current workflow, still tentative, utilizes open-source tools and is designed to be replicable and it has been applied to the case study of the architectural complex of S. Pietro in Segni (RM).

The current workflow, still tentative, utilizes open-source tools and is designed to be replicable and it has been applied to the case study of the architectural complex of S. Pietro in Segni (RM).

Two early cinquecento Renaissance polyptychs by Antonio de Saliba on Sicily and Malta: an art-historical and scientific investigationtion

2024-05-13T09:10:28+00:00

This study focuses on two Renaissance polyptychs that were produced by Antonio (1466/7–c. 1535) and Giovanni de Saliba (doc. 1461–1517?), referred to in this study as the Taormina Polyptych (1503–04) and the Rabat Polyptych (1510–15). Through art-historical research and scientific analyses, this study sheds light on their original visual completion and manufacturing techniques. The Taormina Polyptych, located at the Cathedral of St Nicholas of Bari in Taormina, Sicily, underwent thorough on-site examination, revealing details overlooked in prior studies. A two-dimensional digital reconstruction, the creation of which was aided by early 20^th century photographs, provided insights into its original appearance. The Rabat Polyptych, once situated in the Franciscan Observant Church in Rabat, Malta, faced dismemberment in 1785, leading to challenges in reconstruction. By analysing historical documents and employing digital reconstruction techniques, the original framework was hypothesised. Scientific studies, including histological and stratigraphic analyses of wood and pigment samples respectively, carried out on two newly discovered predella panels from the Rabat Polyptych, provided insight on Antonio de Saliba's techniques. The digital reconstructions and insights into manufacturing techniques contribute to scholarship on Antonio’s works in the context of Sicilian Renaissance art.

Analysis of buried ink elements in library artefacts using pulsed thermography

2024-04-08T13:12:44+00:00

Pulsed thermography is a well-established method for the non-destructive analysis of cultural heritage items. This technique has been recently applied by the authors of this paper for reading written scraps, used for the making of bookbinding of ancient manuscripts, located between the end papers and the covers. The readability of the hidden text depends on several geometrical, optical and thermal parameters characterizing the typology of paper and the ink employed. To this end, a comprehensive mathematical model was developed by the authors for analyzing the influence of the various involved parameters. In particular, two indices were introduced, namely the signal contrast and the distortion index, used to quantitatively characterize the hidden text readability. Several numerical simulations are reported for assessing the dependence of the contrast and distortion from various parameters appearing in the model. Finally, a preliminary application to the analysis of original books is also presented.

Analytical characterization of historical mortars from the Roman villa of Frielas (Loures, Portugal)

2024-05-15T10:47:16+00:00

The analytical characterization of mortar samples from the Roman archaeological site of Frielas, located in Lisbon, Portugal; was carried out by means of X-diffraction (XRD), thermogravimetry (TGA-DTG), optical microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), acid attack and granulometric analysis. A total of eighteen mortar samples were collected from the different structures of the villa with different functional uses (render, filler, and floor). The results showed a similar composition of binder, while differences in aggregates allowed to establish several groups. Results were discussed as evidence of manufacturing techniques, production technologies, and provenance of possible raw materials. There was no prominent variation that can suggest a different chronology between the group of samples. Though, it is assumed that there might be some renovation, restoration, or partial rebuilding that occurred in the same period. In terms of production technology, proportions ruled by Vitruvius were not followed.

A validity exploration model related to the existence of the generic problem-solving competence

2022-07-18T05:24:16+00:00

There has been a growing focus on exploring the existence of Generic Problem-Solving competence across various fields, leading to heightened attention in this area. However, most of the previous and current approaches are limited in terms of validity and reliability. Thus, this paper aims to propose a new approach based on The Standards for Educational and Psychological Testing validity framework to investigate this matter. The investigation leads to the review of the conceptions of construct validity in educational measurement. The paper concentrates on the proposed validity exploration (VE) model, representing an elaborate enterprise and a serial, progressive procedure aligned with the content and structural validity aspects of The Standards framework. The PISA Computer-based Assessment was used as secondary data for this investigation.

A computer vision approach for the automatic detection of social interactions of dairy cows in automatic milking systems

2023-10-22T14:28:26+00:00

The integration of digital technologies and Artificial Intelligence (DT&AI) in veterinary practice is one of the key topics to improve Herd Health Management (HHM). The HHM includes the prevention of diseases, the assessment of the welfare, and the sustainability production of farm animals. In dairy cattle farming, particular attention is paid to automatic cow detection and tracking, as such information is closely related to animal welfare and thus to possible health issues. Cows are highly social animals; therefore, a better comprehension of social context can help improve their management and welfare. In the field of Precision Livestock Farming, computer vision represents a suitable and non-invasive method for automatic cow detection and tracking. In this study, we developed and tested the reliability of a deep learning-based computer vision system for the automatic recognition of dairy cows in a barn equipped with Automatic Milking System. We aimed to build the social network of 240 dairy cows (primiparous and multiparous) to understand how social interactions can influence their welfare and productivity.

Internet of things infrared imaging device for assessing lameness in racehorses

2023-09-24T16:38:33+00:00

Lameness is a clinical condition that heavily affects racehorses. As a result, their competitive performance is dramatically deteriorated and side effects such as changes in feeding patterns may manifest. Within this work we have presented a developed portable Internet of Things (IoT) infrared imaging device, whose application is aimed towards on-site farm level detection of lameness in equine. Additionally we have presented an in-debt review of the causes of lameness, the underlying biological changes that it induces, its influence over tissue thermal patterns and how exercise affects a racehorse's temperature profile.

Time and Metrology

2024-03-15T15:28:36+00:00

The recourse to Quantum Mechanics for the definition of the International System of Units has been the trigger of significant progress. In the first part of the paper, we briefly recall the definitions of units now in use for the basic quantities. We summarize the levels of precision available today within the framework of these definitions.

Time, whether we are aware of it or not, is a very special physical quantity. We therefore expose the extended use that could be made of the expression of physical quantities by means of time, like what is already practiced for the masses, expressed by means of energies. We detail a little more the case of the electrical quantities voltage and resistance which, without being basic quantities, benefit from new approaches thanks to two quantum phenomena: the Josephson effect, and the Quantum Hall Effect.

But time is not an absolute. The next part of the paper exposes the corresponding teachings brought by Special Relativity on the one hand, and General Relativity on the other hand.

Finally, the perspectives of the field are approached under the aspect of the metrological repercussions. Indeed, the technologies applicable to the measurement of time lead to performances that can be considered extraordinary in absolute terms, and in any case superior in relative to anything that can be achieved for other physical quantities.

In conclusion, we examine the challenge that may represent the achievement of ever-increasing metrological performance for all physical quantities, and for time in particular, and the perspectives opened up for research in the domain by fields of knowledge not yet covered.

Bearing fault detection using second-order moment spectrum and adaptive time-varying morphological filtering

2024-05-11T15:22:01+00:00

The second-order moment spectrum is a method designed to simplify the complex shape of the spectrum, thus facilitating its interpretation for the identification and localization of defects based on peak frequency. Generally used as a final step in defect detection methods, this method offers the advantage of a more easily interpretable spectral shape. Compared to the shape of the spectrum of the vibration signal defined by the Fourier transform, which includes sidebands composed of peaks of large amplitude at different frequencies, the spectrum generated by the second-order moment spectrum method stands out for its simplicity. Starting from the mean and standard deviation of the vibration signal, the second-order moment can be defined as the power of the ratio between the standard deviation and the difference between the signal and the mean. Next, the Fourier transform is applied to express the second-order moment spectrum. The performance of the second-order moment spectrum is evaluated using the principle of comparison with the envelope spectrum obtained by the Hilbert transform. Vibration signals are analyzed using two methods: adaptive time-varying morphological filtering and second-order moment spectrum. After applying these methods to the signals from the database, we observe high-amplitude peaks at the frequencies corresponding to inner ring and ball defects. The second-order moment spectrum gives similar results to those obtained with the Hilbert transform envelope.

A monitoring platform based on electrical impedance and AI techniques to enhance the resilience of the built environment

2024-02-06T18:11:18+00:00

Structural Health Monitoring (SHM) and early warning systems (EWSs) play a pivotal role in enhancing seismic resilience for both buildings and occupants. This paper introduces a monitoring platform that collects electrical impedance data from scaled concrete beams undergoing load and accelerated degradation tests. Artificial Intelligence (AI) algorithms are employed for predictive analysis, scrutinizing historical impedance data, and forecasting future trends. These algorithms adapt to environmental parameters, becoming valuable tools in data-driven decision-making processes. In particular, the study investigates concrete specimens in different test conditions, utilizing a distributed sensor network based on electrical impedance as well as temperature and relative humidity sensors. Real-time data are transmitted to a cloud infrastructure during accelerated degradation tests (both in water and in chloride-rich solution) and in room conditions. An AI-based forecasting approach using Prophet is proposed, ingesting electrical impedance and temperature data, and tested to predict electrical impedance corresponding to approximately 10 % of the time series balancing responsiveness with predictive accuracy, crucial for effective EWS operations and management requirements. The performance of the tested models is evaluated employing metrics such as Mean Average Error (MAE), Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE), and correlation. The proposed approach surpasses statistical methods and deep learning techniques, reporting a MAPE always lower than 3.20 % and a correlation higher than 81.65 % (in wet-dry cycles in water these values are 0.65 Ω and 91.85 %, respectively). This proves to be a promising step towards transparent SHM, which integrates AI models facilitating self-monitoring and early maintenance prediction, thus enhancing the resilience of the built environment.

Design of an experimental approach based on the contrast-to-noise ratio measurement for X-ray computed tomography parameters optimization applied to a carbon fiber-reinforced polymer materials scan

2024-05-04T19:05:43+00:00

This paper proposes a systematic approach for the optimization of scan parameters for industrial X-ray computed tomography (XCT), as regard its specific application as diagnostic tool on carbon fiber-reinforced polymer materials (CFRP).

This procedure allows the system operator to overcome suboptimal scan results due to a subjective choice of XCT parameters. In this work, XCT scan quality has been measured in terms of contrast-to-noise ratio (CNR) metric, by calculating it on collected XCT 2D projection images. A four-factor five-level central composite design (CCD) was implemented to perform experiments, and a quadratic polynomial model was chosen to describe the effects of XCT scanning parameters combination on CNR measurement and finally to predict optimal results. Analysis of variance was carried out to evaluate the significance of the model on the response, reporting a R² of 97.1%, and response surface analyses were also performed for CNR optimization purposes. In order to validate the CCD results, different XCT parameters combinations, coming from the CCD analysis on projection images, were used to run different scans, and, as result, the optimal CNR predicted from the model was also reflected in an optimal CNR measured on the reconstructed XCT images.

Thrust ball bearing fault identification from visualized data using optimized deep network

2024-05-31T09:15:41+00:00

Bearings are the most common components employed in machine parts. The bearings' movement facilitates the smooth motion. They also help with friction reduction. The faults in bearings are often caused by tribological parameters. Various methods have been developed to identify faults in bearings, but they often fail to predict these accurately. This work has concentrated on designing an effective fault-recognizing model. Therefore, a framework, the Zebra-based Radial Basis Prediction Mechanism (ZbRBPM), was proposed in this work. Initially, the bearing datasets are collected, and mineral oil (MO) lubrication is added to minimize wear and friction. The primary goal of the work is to detect and classify the fault in the thrust ball bearing. The bearing vibration data included a normal vibration signal, a ball fault, and inner and outer race faults. Hence, Zebra fitness is enhanced for the optimization of tribological parameters and fault identification. The proposed model is executed in the MATLAB system. Finally, performance criteria like accuracy, precision, recall, F-score, error rate, computation time, speed, specific wear rate, friction torque, and energy consumption are validated. The performance of the proposed ZbRBPM gains better accuracy rate as 99.5 %, 99 % of precision and f-score and 99.4 % of recall. Also it significantly reduced the prediction error rate into 0.5 % with lower computation time and very low wear and friction.

Journal contacts

2024-09-29T09:22:29+00:00

Introductory notes for the Acta IMEKO third issue in 2024

2024-09-29T01:38:01+00:00

Editorial to selected papers from the 2023 IMEKO TC8 & TC11 & TC24 Joint Conference

2024-09-08T12:46:09+00:00

Editorial to selected papers from the 2023 IMEKO International Conference on ‘Metrology for Archaeology and Cultural Heritage’ – part 2

2024-09-28T09:56:41+00:00