bluuebunny/crossref_metadata_2025 huggingface dataset:
Meso scale component manufacturing: a comparative analysis of non-lithography and lithography-based processes
Authors: Khalid Azfar , Wei Yang , Saleem Muhammad Rizwan , Lughmani Waqas Akbar
Published: April 2022

The paper identifies the meso scale (10 µm to few millimeters) component size that can be manufactured by using both lithography and non-lithography based approaches. Non-lithography based meso/micro manufacturing is gaining popularity to make micro 3D artifacts with various engineering materials. Being in the nascent stage, this technology looks promising for future micro manufacturing trends. Currently, lithography based micro manufacturing techniques are mature, and used for mass production of 2D, 2.5D features and products extending to 3D micro parts in some cases. In this paper, both the techniques at state-of-the-art level for meso/micro scale are explained first. The comparison is arranged based on examples and a criterion is set in terms of achievable accuracy, production rate, cost, size and form of artifacts and materials used. The analysis revealed a third combined approach where a mix of both techniques can work together for meso scale products. Critical issues affecting both the manufacturing approaches, to advance in terms of accuracy, process physics, materials, machines and product design are discussed. Process effectiveness guideline with respect to the component scale, materials, achievable tolerances, production rates and application is emerged, as a result of this exercise.
Shot-by-shot 250 kHz 3D ion and MHz photoelectron imaging using Timepix3
Authors: Bromberger Hubertus , Passow Christopher , Pennicard David , Boll Rebecca , Correa Jonathan , He Lanhai , Johny Melby , Papadopoulou Christina C , Tul-Noor Atia , Wiese Joss , Trippel Sebastian , Erk Benjamin , Küpper Jochen
Published: April 2022

We demonstrate the application of event-driven Timepix3-based detectors in combination with a double-sided velocity-map-imaging spectrometer to record the full 3D momentum of charged particles at the free-electron-laser facility FLASH. We measured the extreme ultraviolet induced fragmentation of N2 using 250 kHz FLASH bursts with sub-pixel spatial resolution and up to 1.7 ns temporal resolution for photoelectrons. To further demonstrate the capabilities of this camera at even higher repetition rates we measured single-shot images of He(1s) photoelectrons for bursts with a repetition rate of 1 MHz. Overall, with the Timepix3 camera we overcome limitations of standard-camera technology for advanced-imaging experiments with requirements on high event-rates and high spatio-temporal resolution.
Effect of the flow rate of the shielding gas on the species fluxes in the coaxial double-tube helium atmospheric pressure plasma jet
Authors: Chen Zhongqi , Zhong An , Dai Dong , Ning Wenjun
Published: April 2022

The effect of ambient air as an unavoidable problem for atmospheric pressure plasma jet (APPJ) applications has attracted a lot of interest, especially when the specific scenarios are highly sensitive to ambient species such as the biomedical process. The coaxial double-tube device is a promising method for controlling the ambient species into the jet effluent and thus the chemical properties of the jet effluent. In this work, the discharge characteristics and plasma chemistry of the coaxial double-tube helium APPJ at different shielding gas (SG) flow rates are studied numerically. An experiment on optical images of the discharge is conducted to illustratively validate the variation of the (main) discharge channel widths in the model as the SG flow rate varies. The results illustrate that the discharge is enhanced at the high flow rate, while it shows the weaker discharge behavior at the low flow rate as well as that without SG. The analysis of the dielectric plate surface indicates that the species fluxes to the dielectric plate significantly increase with the increases in the flow rate, which can be attributed to the wider (main) discharge channel. Moreover, to further explore the impact of the SG on the effluent chemistry, the ions fluxes on the surfaces of the main discharge channel and the discharge channel are distinguished and discussed. The analysis shows the great difference in the ions fluxes affected by the flow rate between the two discharge channels. In summary, advancing the knowledge that the flow rate of the SG has an impact on the discharge behavior, this study further reveals that different discharge positions greatly influence the production of nitrogen/oxygen species. This work enables the previously elusive account of the effect of SG and may open new opportunities for the further application of coaxial double-tube APPJ.
Orientational disorder in sulfur hexafluoride: a neutron total scattering and reverse Monte Carlo study
Authors: Zhang Shidong , Qin Yinze , Zhang Sijie , Gao Min , Tucker Matthew G , Keen David A , Cai Guanqun , Phillips Anthony E , Dove Martin T
Published: April 2022

The orientational disorder in crystalline sulfur hexafluoride, SF6, has been studied using a combination of neutron total scattering and the reverse Monte Carlo method. Analysis of the atomic configurations has shown the extent of the disorder through the evaluation of the S–F bond orientational distribution function, consistent with, but improving upon, the results of earlier neutron powder diffraction data. The correlations between orientations of neighbouring molecules have been studied through analysis of the distributions of F–F distances, showing that nearest-neighbour F–F close contacts are avoided, consistent with previous molecular dynamics simulation results. The results present a new case study of the application of neutron total scattering and the reverse Monte Carlo methods for the study of orientational disorder, where in this instance the disorder arises from orientational frustration rather than from a mismatch of molecular and site symmetries.
Organic self-assembled monolayers on superconducting NbSe2: interfacial electronic structure and energetics*
Authors: Ni Xiaojuan , Li Hong , Brédas Jean-Luc
Published: April 2022

While organic self-assembled monolayers (SAMs) have been widely used to modify the work function of metal and metal-oxide surfaces, their application to tune the critical temperature of a superconductor has only been considered recently when SAMs were deposited on NbSe2 monolayers (Calavalle et al 2021 Nano Lett.
21 136–143). Here, we describe the results of density functional theory calculations performed on the experimentally reported organic/NbSe2 systems. Our objectives are: (i) to determine how the organic layers impact the NbSe2 work function and electronic density of states; (ii) to understand the possible correlation with the experimental variations in superconducting behavior upon SAM deposition. We find that, upon adsorption of the organic monolayers, the work-function modulation induced by the SAM and interface dipoles is consistent with the experimental results. However, there occurs no significant difference in the electronic density of states near the Fermi level, a consequence of the absence of any charge transfer across the organic/NbSe2 interfaces. Therefore, our results indicate that it is not a SAM-induced tuning of the NbSe2 density of states near the Fermi level that leads to the tuning of the superconducting critical temperature. This calls for further explorations, both experimentally and theoretically, of the mechanism underlying the superconducting critical temperature variation upon formation of SAM/NbSe2 interfaces.
Pre- and post-accident environmental transfer of radionuclides in Japan: lessons learned in the IAEA MODARIA II programme
Authors: Tagami Keiko , Hashimoto Shoji , Kusakabe Masashi , Onda Yuichi , Howard Brenda , Fesenko Sergey , Pröhl Gerhard , Harbottle Andra-Rada , Ulanowski Alexander
Published: April 2022

An international review of radioecological data derived after the accident at the Fukushima Daiichi nuclear power plant was an important component of activities in working group 4 of the IAEA Models and data for radiological impact assessment, phase II (MODARIA II) programme. Japanese and international scientists reviewed radioecological data in the terrestrial and aquatic environments in Japan reported both before and after the accident. The environmental transfer processes considered included: (a) interception and retention radionuclides by plants, (b) loss of radionuclides from plant and systemic transport of radionuclides in plants (translocation), (c) behaviour of radiocaesium in soil, (d) uptake of radionuclides from soil by agricultural crops and wild plants, (e) transfer of radionuclides from feedstuffs to domestic and wild animals, (f) behaviour of radiocaesium in forest trees and forest systems, (g) behaviour of radiocaesium in freshwater systems, coastal areas and in the ocean, (h) transport of radiocaesium from catchments through rivers, streams and lakes to the ocean, (i) uptake of radiocaesium by aquatic organisms, and (j) modification of radionuclide concentrations in food products during food processing and culinary preparation. These data were compared with relevant global data within IAEA TECDOC-1927 ‘Environmental transfer of radionuclides in Japan following the accident at the Fukushima Daiichi Nuclear Power Plant’. This paper summarises the outcomes of the data collation and analysis within MODARIA II work group 4 and compares the Japan-specific data with existing radioecological knowledge acquired from past and contemporary radioecological studies. The key radioecological lessons learned are outlined and discussed.
Implementing a non-local lattice particle method in the open-source large-scale atomic/molecular massively parallel simulator
Authors: Sun Hao , Ferasat Keyvan , Nowak Philip , Gravelle Liam , Gaffran Noah , Anderson Chris , Sirola Tim , Pintar Owen , Lievers W Brent , Kim Il Yong , Pilkey Keith , Béland Laurent Karim
Published: April 2022

Using conventional continuum-based simulation frameworks to model crack initiation and extension can be computationally challenging. As an alternative to continuum-based approaches, particle-based simulation methods are well-suited to handle the discontinuities present during fracture propagation. A well-known particle-based method is the lattice particle method (LPM), which discretizes the system into a set of interconnected particles ollowing a periodic arrangement. Discontinuities can be handled simply by removing bonds between particles. For this reason, LPM-based simulations have been employed to simulate fracture propagation in heterogeneous media, notably in civil engineering and biomaterials applications. However, a practical limitation of this method is the absence of implementation within a commonly-used software platform. This work describes such an implementation of a non-local LPM within the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). Specifically, we implemented a new LAMMPS bond style with a many-body term to tune Poisson’s ratios. In order to validate the nonlocal formalism and our implementation of this method within LAMMPS, simulated elastic properties are compared to analytical solutions reported in the literature. Good agreement between simulated and analytical values is found for systems with positive Poisson’s ratios. The computational and parallel efficiency of the LPM-LAMMPS implementation is also benchmarked. Finally, we compare the elastic response of a 3D porous structure and an aircraft wing as calculated using the LPM and finite-element analysis.
Hyperplane families creating envelopes
Authors: Nishimura Takashi
Published: April 2022

A simple geometric mechanism: ‘the locus of intersections of perpendicular bisectors and normal lines’, often arises in many guises in nonlinear sciences. In this paper, a new application of this simple geometric mechanism is given. Namely, we show that this mechanism gives answers to all four basic problems on envelopes created by hyperplane families (existence problem, representation problem, equivalence problem of definitions, uniqueness problem) at once.
External beam irradiation angle measurement using a hybrid Cerenkov-scintillation detector
Authors: Jean Emilie , Lambert-Girard Simon , Therriault-Proulx François , Beaulieu Luc
Published: April 2022

Objective. In this study, we propose a novel approach designed to take advantage of the Cerenkov light angular dependency to perform a direct measurement of an external beam irradiation angle. Approach. A Cerenkov probe composed of a 10 mm long filtered sensitive volume of clear PMMA optical fibre was built. Both filtered and raw Cerenkov signals from the transport fibre were collected through a single 1 mm diameter transport fibre. An independent plastic scintillation detector composed of 10 mm BCF12 scintillating fibre was also used for simultaneous dose measurements. A first series of measurements aimed at validating the ability to account for the Cerenkov electron energy spectrum dependency by simultaneously measuring the deposited dose, thus isolating signal variations resulting from the angular dependency. Angular calibration curve for fixed dose irradiations and incident angle measurements using electron and photon beams where also achieved. Main results. The beam nominal energy was found to have a significant impact on the shapes of the angular calibration curves. This can be linked to the electron energy spectrum dependency of the Cerenkov emission cone. Irradiation angle measurements exhibit an absolute mean error of 1.86° and 1.02° at 6 and 18 MV, respectively. Similar results were obtained with electron beams and the absolute mean error reaches 1.97°, 1.66°, 1.45° and 0.95° at 9, 12, 16 and 20 MeV, respectively. Reducing the numerical aperture of the Cerenkov probe leads to an increased angular dependency for the lowest energy while no major changes were observed at higher energy. This allowed irradiation angle measurements at 6 MeV with a mean absolute error of 4.82°. Significance. The detector offers promising perspectives as a potential tool for future quality assurance applications in radiotherapy, especially for stereotactic radiosurgery (SRS), magnetic resonance image-guided radiotherapy (MRgRT) and brachytherapy applications.
Coherent and incoherent superposition of transition matrix elements of the squeezing operator
Authors: Varró Sándor
Published: April 2022

We discuss the general matrix elements of the squeezing operator between number eigenstates of a harmonic oscillator (which may also represent a quantized mode of the electromagnetic radiation). These matrix elements have first been used by Popov and Perelomov (1969 Zh. Eksp. Teor. Fiz.
56 1375–90) long ago, in their thorough analysis of the parametric excitation of harmonic oscillators. They expressed the matrix elements in terms of transcendental functions, the associated Legendre functions. In the present paper we will show that these matrix elements can also be derived in a different form, expressed by the classical Gegenbauer polynomials. This new expression makes it possible to determine coherent and incoherent superpositions of these matrix elements in closed analytic forms. As an application, we describe multiphoton transitions in the system ‘charged particle + electromagnetic radiation’, induced by a (strong) coherent field or by a black-body radiation component (with a Planck–Bose photon number distribution). The exact results are compared with the semi-classical ones. We will show that in case of interaction with a thermal field, the semi-classical result (with a Gaussian stochastic field amplitude) yields an acceptable approximation only in the Rayleigh–Jeans limit, however, in the Wien limit it completely fails.
Unification of random dynamical decoupling and the quantum Zeno effect
Authors: Hahn Alexander , Burgarth Daniel , Yuasa Kazuya
Published: April 2022

Periodic deterministic bang–bang dynamical decoupling and the quantum Zeno effect are known to emerge from the same physical mechanism. Both concepts are based on cycles of strong and frequent kicks provoking a subdivision of the Hilbert space into independent subspaces. However, previous unification results do not capture the case of random bang–bang dynamical decoupling, which can be advantageous to the deterministic case but has an inherently acyclic structure. Here, we establish a correspondence between random dynamical decoupling and the quantum Zeno effect by investigating the average over random decoupling evolutions. This protocol is a manifestation of the quantum Zeno dynamics and leads to a unitary bath evolution. By providing a framework that we call equitability of system and bath, we show that the system dynamics under random dynamical decoupling converges to a unitary with a decoupling error that characteristically depends on the convergence speed of the Zeno limit. This reveals a unification of the random dynamical decoupling and the quantum Zeno effect.
The local PNG bias of neutral Hydrogen, HI
Authors: Barreira Alexandre
Published: April 2022

We use separate universe simulations with the IllustrisTNG galaxy formation model to predict the local PNG bias parameters bΦ
and bΦδ
of atomic neutral hydrogen, HI. These parameters and their relation to the linear density bias parameter b
1 play a key role in observational constraints of the local PNG parameter f
NL using the HI power spectrum and bispectrum. Our results show that the popular calculation based on the universality of the halo mass function overpredicts the bΦ
(b
1) and bΦδ
(b
1) relations measured in the simulations. In particular, our results show that at z ≲ 1 the HI power spectrum is more sensitive to f
NL compared to previously thought (bΦ
is more negative), but is less sensitive at other epochs (bΦ
is less positive). We discuss how this can be explained by the competition of physical effects such as that large-scale gravitational potentials with local PNG (i) accelerate the conversion of hydrogen to heavy elements by star formation, (ii) enhance the effects of baryonic feedback that eject the gas to regions more exposed to ionizing radiation, and (iii) promote the formation of denser structures that shield the HI more efficiently. Our numerical results can be used to revise existing forecast studies on f
NL using 21 cm line-intensity mapping data. Despite this first step towards predictions for the local PNG bias parameters of HI, we emphasize that more work is needed to assess their sensitivity on the assumed galaxy formation physics and HI modeling strategy.
High gain and circularly polarized substrate integrated waveguide cavity antenna array based on metasurface
Authors: Bai Hao , Wang Guang-Ming , Zou Xiao-Jun
Published: April 2022

Two substrate integrated waveguide (SIW) cavity antenna arrays based on metasurface are proposed in this paper. By rotating the metasurface element, circularly polarized and high gain antennas are achieved respectively. Firstly, multi-mode resonance theory is employed to broaden the bandwidth of the slot antenna. And then, an SIW cavity composed of 4 × 4 cornercut elements is added on the top of the slot antenna to achieve the circular polarization and improve the front-to-back ratio. Thirdly, the metasurface elements are sequentially rotated and a high gain antenna with 2-dBi enhancement on average in the operation band is obtained. Based on the two antenna units, two 2×2 antenna arrays are designed. The circularly polarized and high gain antenna arrays are both fabricated to verify the correctness. Furthermore, the novel wideband phase shifter is employed in the circularly polarized antenna to obtain an operating bandwidth of 38% (4.05 GHz–5.95 GHz) and AR bandwidth of 24.9% (4.4 GHz–5.65 GHz). The bandwidth of the high gain antenna can reach 42.7% (3.95 GHz–6.1 GHz) and with the gain enhancement of 2 dBi compared with that of the circularly polarized antenna. The gain remains steady in most of operating band within a variation of 1 dBi. It is remarkable that the rotating of the metasurface element has a great influence on the antenna performance, which provides a new explication for the multi-function antenna design.
Method of measuring one-dimensional photonic crystal period-structure-film thickness based on Bloch surface wave enhanced Goos–Hänchen shift
Authors: Lang Yao-Pu , Liu Qing-Gang , Wang Qi , Zhou Xing-Lin , Jia Guang-Yi
Published: April 2022

This paper puts forward a novel method of measuring the thin period-structure-film thickness based on the Bloch surface wave (BSW) enhanced Goos–Hänchen (GH) shift in one-dimensional photonic crystal (1DPC). The BSW phenomenon appearing in 1DPC enhances the GH shift generated in the attenuated total internal reflection structure. The GH shift is closely related to the thickness of the film which is composed of layer-structure of 1DPC. The GH shifts under multiple different incident light conditions will be obtained by varying the wavelength and angle of the measured light, and the thickness distribution of the entire structure of 1DPC is calculated by the particle swarm optimization (PSO) algorithm. The relationship between the structure of a 1DPC film composed of TiO2 and SiO2 layers and the GH shift, is investigated. Under the specific photonic crystal structure and incident conditions, a giant GH shift, 5.1 × 103 times the wavelength of incidence, can be obtained theoretically. Simulation and calculation results show that the thickness of termination layer and periodic structure bilayer of 1DPC film with 0.1-nm resolution can be obtained by measuring the GH shifts. The exact structure of a 1DPC film is innovatively measured by the BSW-enhanced GH shift.
Development of ZnTe film with high copper doping efficiency for solar cells
Authors: Lin Xin-Lu , Zhao Wen-Xiong , Wu Qiu-Chen , Zhang Yu-Feng , Mahabaduge Hasitha , Liu Xiang-Xin
Published: April 2022

Since a hole barrier was formed in back contact due to mismatch of work function, the back contact material for CdTe cell has been a significant research direction. The ZnTe:Cu is an ideal back contact material, which reduces the valence band discontinuity and can be used as the electron back reflection layer to inhibit interface recombination. The conductivity of ZnTe:Cu film is improved by applying RF-coupled DC sputtering and post-deposition heat treatment. The doping efficiency is computed as the ratio of free hole density and copper concentration, which can be correlated with performance for CdTe-based solar cell. The higher doping efficiency means that more copper atoms substitute for Zn sites in ZnTe lattices and less mobilized copper atoms remain which can enter into the CdTe absorber layer. Copper atoms are suspected as dominant element for CdTe-based cell degradation. After optimizing the ZnTe:Cu films, a systematic study is carried out to incorporate ZnTe:Cu film into CdTe solar cell. The EQE spectrum is kept relatively stable over the long wavelength range without decreasing. It is proved that the conduction band barrier of device with ZnTe:Cu/Au contact material has an effect on the EQE response, which works as free electron barrier and reduces the recombination rate of free carrier. According to the dark J–V data or the light J–V data in the linear region, the current indicates that the intercept gives the diode reverse saturation current. The results of ideality factor indicate that the dominant recombination occurs in the space charge region. In addition, the space charge density and depletion width of solar cell can be estimated by C–V profiling.
Hexagonal boron phosphide and boron arsenide van der Waals heterostructure as high-efficiency solar cell
Authors: Li Yi , Wei Dong , Guo Gaofu , Zhao Gao , Tang Yanan , Dai Xianqi
Published: April 2022

The rapid development of two-dimensional (2D) materials offers new opportunities for 2D ultra-thin excitonic solar cells (XSCs). The construction of van der Waals heterostructure (vdWH) is a recognised and effective method of integrating the properties of single-layer 2D materials, creating particularly superior performance. Here, the prospects of h-BP/h-BAs vdW heterostructures in 2D excitonic solar cells are assessed. We systematically investigate the electronic properties and optical properties of heterogeneous structures by using the density functional theory (DFT) and first-principles calculations. The results indicate that the heterogeneous structure has good optoelectronic properties, such as a suitable direct bandgap and excellent optical absorption properties. The calculation of the phonon spectrum also confirms the well-defined kinetic stability of the heterstructure. We design the heterogeneous structure as a model for solar cells, and calculate its solar cell power conversion efficiency which reaches up to 16.51% and is higher than the highest efficiency reported in organic solar cells (11.7%). Our work illustrates the potential of h-BP/h-BAs heterostructure as a candidate for high-efficiency 2D excitonic solar cells.
Investigation of the W/Y2O3 heterogeneous interface properties and its effect on hydrogen behavior using first-principles calculations
Authors: Wen ShuLong , Zhang XingMing , Deng HuiQiu , Pan Min
Published: April 2022

Here, first-principles calculations were employed to study the properties of the W/Y2O3 interface and its effect on H dissolution and migration. Two W/Y2O3 interface structures were selected to investigate the influence of terminal structures and stacking sequences on the interface properties. The Y4O6–W (bridge) and O–W type A terminal interface exhibited the lowest interface energy at the W (110)/Y2O3 (222) interface with the orientation of W (1-10) (

2

2

×
5

)/Y2O3 (2-1-1) (

3

/
2
×

2

) and at the W (200)/Y2O3 (400) interface with the orientation of W (001) (3 × 3)/Y2O3 (001) (1 × 1). The work of adhesion of the O–W type terminal interface is larger than those of the Y–W type and Y
n
O
m
–W terminal interfaces, indicating that the O–W type A terminal interface has the most stable structure. Atomic-bonding analysis confirmed that the W–O bond plays an essential role in stabilizing the interface structure, and the stability improves as the density of the W–O bonds at the interface increases. These conclusions are further verified by charge-density difference calculations, which revealed that strong ionic bonds are formed between the W and O atoms at the W/Y2O3 interface. With regard to the H behavior at the W (200)/Y2O3 (400) interface, the segregation energy confirmed that the interface plays an important role in the segregation of H. The migration energy barrier of interstitial H along the interface is greater than that in the bulk. This means that the interface retains a significant number of injected H atoms, leading to an increase in the local concentration of H atoms at the interface. These results provide theoretical insights into the profound understanding of the interface properties and its effect on H behavior in Y2O3-dispersion-strengthened W.
Raman Spectroscopy Study of Ancient Vaccaei (s. IV-I BC) Glass Beads found at the Necropolis of “Las Ruedas” (Padilla de Duero, Valladolid, Spain)
Authors: Pinto Javier , Barroso-Solares Suset , Souto Jorge , Rodriguez E. , Sanz-Minguez Carlos , Prieto Angel Carmelo
Published: April 2022

Glass pieces were highly appreciated imported goods in the Protohistory of the Iberian Peninsula. Therefore, these remainings could provide evidence about the commercial or political relationships among contemporary cultures. However, archaeometry studies of glass beads are scarce in the Iberian Peninsula, and their results are difficult to generalize, as the studied glass beads are often found without clear historical context. On the contrary, the archaeological site of Pintia (Padilla de Duero, Valladolid, Spain) have provided about one thousand glass beads in the last decades, being a significant percentage found in well-contextualized closed tombs. Ten representative samples found in closed tombs have been selected in this work to deepen in our knowledge of the Vaccaei culture (IV-I BC). The study of the glass network of these pieces by Raman spectroscopy provided an estimation of the firing temperatures employed to produce such samples, and hence evidenced the technological development required for their production. Also, the combination of the Raman spectroscopy results with elemental analysis by ESEM/EDX narrowed the composition of the glass, as well as the pigments employed to obtain blue, yellow-orange, and green tones. Particularly, the presence of complex pigments such as lead antimoniates (e.g., Naples yellow) was confirmed. Moreover, it was possible to identify the surface degradation processes suffered by these samples. Finally, information about the complex funerary rituals performed by the Vaccaei, involving cremation, was also provided. The evolution of the glass network of glass beads altered by the cremation, evidenced by Raman spectroscopy, narrow the cremation temperature to about 600 °C.
A metabarcoding approach for the study of biodeterioration of ancient wall paintings in an Italian cave
Authors: Cennamo Paola , Luca Daniele De
Published: April 2022

Caves represent unique habitats for the development of microbial communities due to particular environmental conditions. Mural paintings occurring in caves suffer from degradation caused by natural processes in which microorganisms are significantly involved. The characterization of the microbial biofilm with non-destructive analysis is important to better preserve and safeguard these artifacts. This study aimed at investigating the microbial communities colonising the frescoes in the Fornelle cave (Calvi Risorta, Caserta, Italy) using a metabarcoding approach. We found a high representation of eubacteria, followed by cyanobacteria, fungi, and microalgae. This study confirmed the potential of non-invasive techniques as DNA metabarcoding as powerful tool for conservation and restoration of artworks.
Towards a catalogue of Sardinian WWII Heritage. The protection of Quartu Sant’Elena and its territory
Authors: Pirinu Andrea , Argiolas Raffaele , Paba Nicola
Published: April 2022

The essay shows the results of a research aimed at building a digital database of Sardinian military architectures of Second World War. Following an activity of knowledge and cataloguing entrusted to digital survey methods already employed in other case studies, this contribute analyses the IIWW heritage placed in territory of Quartu Sant’Elena, a centre close to Cagliari in the south coast of the island. Many examples of these “sentinels” are positioned along the coastline and the country road and within the actual urban context; these architectures follow the indication of design models indicated by the archival documents using square and circle shape often modified and adapted to achieve a complete mimesis in the landscape that host them. In our case study we found bunkers that seems little churches, houses and water tanks located in a restricted area close to the Simbirizzi lake, in which an integrated (direct, instrumental, and photogrammetric) survey has been carried out.
Fusion and integration of heterogeneous close range remote sensing and geophysical data. The case of Grumentum.
Authors: Masini N , Sogliani F , Sileo M , Abate N , Danese M , Vitale V , Lasaponara R , Piro S
Published: April 2022

This paper deals with the integration and fusion of UAV-based imagery, including Vis-NIR multispectral and infrared thermography data, with georadar and geomagnetic prospecting, applied on Grumentum, pre-Roman and Roman city, with an important phase dated to Late Antiquity, of the ancient Lucania, in Basilicata region. The data were processed individually and then integrated with each other in order to recover as much information as possible from the different signals. Due to the qualitative and quantitative approaches to the integration and fusion of the diverse data sets and features, it was possible to detect some urban blocks (insulae) reasonably referable to the Roman age, although obviously not datable, and other features spatially linked to the late antique/early medieval church. Grumentum’s experience shows considerable potential as well as limits in the use of the image fusion-based approach for the enhancement of archaeological features, from which emerges the need to continue experimenting these approaches on a greater number of case studies.
Terrestrial and UAV based infrared thermography for mapping and investigating the humidity of historical buildings. The case of the Castle in Calvello.
Authors: Abate Nicodemo , Lasaponara Rosa , Masini Nicola
Published: April 2022

Humidity is one of the most frequent causes of damage to the architectural heritage. An effective and non-invasive way to detect the presence of humidity and identify the possible causes, from capillary rise to infiltration and condensation, is infrared thermography. The paper shows and describes the results from terrestrial and UAV-based (Unmanned Aerial Vehicle) thermography for understanding the cause-effect mechanisms of infiltration humidity in some halls of the castle of Calvello (in Basilicata), some of them characterized by walls paintings. The analysis of the acquired data allowed us to understand the nature of the damage caused by humidity and water infiltration in the castle structures, and to be able to put in place a plan for risk mitigation and damage resolution.
Multi-scale characterisation of late-medieval tournois of Frankish Greece provenance
Authors: Paladini G , Acri G , Caridi F , Crupi V , Faenza P , Majolino D , Venuti V
Published: April 2022

An archaeometric investigation on 13 late–medievaltournoiswas here accomplished through a combined approach involving X–ray fluorescence (XRF) and Raman techniques. The aim of this study was to determine, starting from the evaluation of the elemental and molecular composition, the raw materials employed for the coin’s alloy and highlight the differences in the coin’s composition according to the location of the original mint and estimated coinage age. The aforementioned aspects not only testify the monetary policy and the political condition of the time, but also would contribute to unambiguously recognize the coin’s original treasury, which is at present an ongoing controversy among the scientific/numismatic community. Finally, the identification of specific minerals by means of Raman spectroscopy allowed us to formulate hypothesis about the state of conservation, and to identify new phases resulting from the soil/burial and climatic environmental coin’s exposition.
A 3D approach to investigate the burials: the virtual reconstruction of tb. 22 of necropolis of Piovego (PD)
Authors: Adesso F , Faresin E , Salemi G
Published: April 2022

The burials of the necropolis of Piovego (PD) have been subjected in the past years to processual research to reconstruct the post-depositional dynamics, thus providing a two-dimensional reconstruction of the original structure of the graves. The goal of this research is to define a new methodology on burial 22 of the necropolis, to replicate in other archaeological contexts. This new methodology aimed to create morphometrically accurate 3D models with a correct topological relationship between the grave finds and between them and the burial structure. 3D models of both the findings and structural elements of the burial were made from graphic documents with the aid of 3D modelling and 3D scanning techniques. The use of 3D models allowed the development of new hypotheses on the placement of the grave goods and their position within the space available in the burial. Furthermore, the models were useful to measure more accurately the perishable elements and to estimate their shape and position. The digital technologies allowed us to work in a three-dimensional perspective, overcoming the limits of a traditional approach and verifying previous hypotheses on the topology of the burial, such as positioning of the finds and the existence of perishable materials that were not preserved.
Structural feature investigation of wooden artifacts through imaging techniques: a step forward in the preservation of historical musical instruments
Authors: Fiocco G. , Ceccarelli S. , Albano M. , Rovetta T. , Malagodi M. , Orazi N. , Paoloni S.
Published: April 2022

Bowed string instruments represent a peculiar class of artworks, in some cases of historical relevance, capable of producing sound. Concert activity and natural ageing could cause mechanical stress that may lead to defects and fractures. Here, we propose an image-based methodology suitable to investigate such structural features in wooden instruments. The combined use of X-ray radiography and infrared thermography enabled a better identification and documentation of defects, woodworm galleries and cracks, thus enhancing the commonly employed approach.
The study of ancient archaeological finds through X-ray tomography: the case of the “Tintinnabulum” from the Museum of Anthropology and Ethnography of Torino
Authors: Vigorelli Luisa , Re Alessandro , Guidorzi Laura , Brancaccio Rosa , Bortolin Cristina , Grassi Novella , Mila Giorgia , Pastrone Nadia , Sacchi Roberto , Grassini Sabrina , Mangiapane Gianluigi , Boano Rosa , Giudice Alessandro Lo
Published: April 2022

X-ray Computed Tomography (CT) is a widely used diagnostic technique in the field of Cultural Heritage and beyond, above all thanks to its non-invasiveness. The high penetrating power of X-rays allows us to investigate the internal structure of the analysed objects, thus obtaining valuable information related to the history of artistic and archaeological finds. In particular, CT provides useful data on the entire volume of the objects, to finally obtain a 3D model of the studied artworks. In this field, the goal of the “neu_ART” project, a collaboration among different institutions in Torino funded by Regione Piemonte in 2010, was to develop radio-tomographic set-ups for X-ray imaging analysis dedicated to Cultural Heritage studies. In this paper, a computed tomography investigation on an ancient ceramic rattle from the Museum of Anthropology and Ethnography of the University of Torino is presented. This is the first analysis carried out at the Physics Department of University of Torino, using the imaging set-up based on a TDI linear detector moved by a high precision mechanical system. Thanks to this study, much information on the technique of execution and the state of conservation was obtained.
Non-destructive magnetic and chemical characterization of granite column shafts traded in the Mediterranean area: the case of Piazza dei Miracoli in Pisa (Italy) and Basilica of Saint-Martin d’Ainay in Lyon (France).
Authors: Rochette P , Sciuto C , Raneri S , Sutter A , Rovazzani A , Folco L. , Ambrosi JP , Andrieu V , Gattacceca J , Hartmann-Virnich A
Published: April 2022

We present a scheme for non-destructive provenancing of granite shafts dating from the Roman to the medieval period using a combination of visual, magnetic, and chemical determinations. Our results on two monumental medieval complexes in Europe, in Pisa and Lyon, shows both oriental provenance, most likely spolia, and shaft from the quarries within the influence zone of the Pisa Republic (Elba, Corsica and Sardinia) that possibly correspond to shafts newly obtained in the quarries, particularly for the large diameter shafts of Ainay in Lyon (from Corsica) and Piazza dei Miracoli (from Elba and Sardinia). pXRF appears to be an efficient way to discriminate Corsican from Egyptian grey coarse grained granite provenance.
Preliminary study on a novel Optimal Placed Sensors method based on Genetic Algorithm.
Authors: Scuro C , Demarco F , Olivito R S , Wang P , Milani G , Li S
Published: April 2022

The safeguarding of the historical and cultural heritage is one of the main research topics that has been addressed in recent years. Particular attention was given to the development of structural health monitoring systems that allowed the real time acquisition of different physical quantities that are stored in a cloud and compared with the health limit values of the structures obtained from numerical analysis previously carried out. One of the major problems highlighted by the use of these systems is related to the position and quantity of smart sensors to be used within the structure to be monitored. To avoid this, in this paper an Optimal Sensors Placement method was applied to a case study located in China. In particular, the positioning of the sensors was identified through an optimization workflow that adopt a Multi Objective Optimization engine called “Octopus” in Grasshopper3D. The identified optimal solutions have made it possible to detect the areas of the structure that will be subject to collapse during a seismic event.
Structural health monitoring system design for historical heritage building
Authors: Carnì D. L. , Scuro C. , Olivito R.S. , Lamonaca Francesco , Alì G. , Calà S
Published: April 2022

Structural Health Monitoring (SHM) systems play an important role in the defence of historical heritage. In fact, it is necessary to monitor and analyse the information that highlight the state of health of the structure. Unfortunately, in the realization of the monitoring system it is necessary to place several sensor nodes in place where it is not simple or possible the connection to the mains power supply. Moreover, it is necessary the fast detection of critical situation in which the state of conservation of an historical building can deteriorate. For these reasons in the paper is proposed the design of a low power consumption long range communication system. This design is proposed as an innovation of previous work, and the use of machine learning an algorithm to analyse the data.
Preliminary study of a mathematical model for the creation of a SHM system against river flooding
Authors: Scuro C , Alì G , Demarco F , Lamonaca F , Olivito R S , Carnì D L
Published: April 2022

The historical and cultural heritage has been damaged and destroyed for many years by catastrophic events. In Italy, the safeguarding of historic masonry buildings from seismic events has drawn the attention of researchers, often underestimating other external factors. This may be due to the fact that, over the centuries, earthquakes have frequently destroyed entire cities. In order to preserve and monitor historical and cultural heritage, structural health monitoring (SHM) systems based on the Internet of Things (IoT) paradigm, associated with maintenance and classification projects such as CARTIS, have been introduced in recent years. These systems guarantee not only the monitoring and maintenance of the single building but also a large-scale control of an urban neighbourhood. The purpose of this paper is to define a preliminary SHM system capable of preserving cities from catastrophic events other than earthquakes, focusing on the study of the phenomenon of river flooding. This is addressed by proposing a monitoring system based on smart nodes implementing new mathematical modelling to foreseen floods.
Non-invasive techniques for characterization of original Roman mosaic fragments
Authors: Radulescu Cristiana , Ion Rodica Mariana , Dulama Ioana Daniela , Gheboianu Anca Irina , Bucurica Ioan Alin
Published: April 2022

In this study, it was reported the preliminary results on the chemical and structural composition of decorative elements remains from original Roman mosaic fragments collected from the Roman Mosaic Museum, Constanta (Romania). These investigations were carried out by using non-destructive and micro-invasive techniques such as optical microscopy, X-ray diffraction, field emission - scanning electron microscopy - energy dispersive X-ray spectroscopy, vibrational spectroscopy (i.e., FTIR and Raman). The studied fragments, apart from being beneficial to different restoration opportunities of this Roman mosaic, could be also included in its modification through air pollution. The major and minor phase components of the studied mosaic fragments were determined, the crystal structure of the main phases was analyzed, and their three-dimension spatial arrangement was reconstructed. The similar composition of the major phases of all mosaic fragments can indicate a generic recipe for making mosaic elements, but minor phases were presumably added for coloring of mosaic pieces. Some degradation areas inside the volume of the mosaic fragments were found by means of the X-ray diffraction method. The areas are probably related to the formation of iron hydroxides during chemical interactions of mosaic fragments with the sea and urban polluted atmosphere. The results can also offer important information about the original materials that were used in the Roman period.
SR-FTIR microscopy for the study of residues on Palaeolithic stone tools: looking for a methodological protocol
Authors: Dominici C , Stani C , Rossini M , Vaccari L
Published: April 2022

In this paper, we use SR-FTIR microscopy to analyse residues identified on seven lithic artefacts from the Evolved Epigravettian layer 9c2 of the cave site of Grotta Paglicci (Apulia, southern Italy). Synchrotron radiation, thanks to its properties that particularly increase the sensitivity of FTIR microscopy, allows the analysis of samples of microscopic size and the characterisation of even highly degraded compounds, such as the residues of materials worked by Palaeolithic stone tools or complex compounds used for hafting. This pilot study has been carried out in the framework of a project concerning the reconstruction of hunting technologies between the Middle and Upper Palaeolithic. The preliminary results allowed us to focus on the issues of our methodological approach and to show the potential of the SR-FTIR microscopy for the analysis of residues on lithic implements.
Permittivity of wood as a function of moisture for cultural heritage applications: a preliminary study
Authors: D’Alvia L , Piuzzi E , Cataldo A , Del Prete Z
Published: April 2022

In this work, the evaluation of moisture content in historic wooden objects starting from permittivity measurements is investigated. For this purpose, a WR430 waveguide with a 1.7-2.6 GHz range was used to estimate the complex permittivity correlated to different moisture levels. Experimental tests were carried out on poplar (Populus nigra L.), a wood typically used in central Italy in the thirteenth-sixteenth centuries as a painting support. For the considered measurement system, experimental results and calibration curves are reported.
Study of the edge distortion effect in thermographic detection in semi-transparent Cultural Heritage
Authors: Ceccarelli Sofia , Caruso G. , Mercuri F. , Paoloni S. , Zammit U. , Orazi N.
Published: April 2022

In library heritage, the practice of reusing fragments of older manuscripts was very common, providing complex structures characterised by several overlapped features. Pulsed Thermography enables non-destructive investigations of such a stratigraphic structure and the detection of hidden texts. In this work, a study of the contrast generation in their thermographic detection is presented, aimed to the evaluation of the edges distortion for enhancing the readability of such features which is crucial for palaeographic purposes.