bluuebunny/crossref_metadata_2025 huggingface dataset:
On-chip monolithic wide-angle field-of-view metalens based on quadratic phase profile
Authors: Chen Cong , Chen Panpan , Xi Jianxin , Huang Wanxia , Li Kuanguo , Liang Li , Shi Fenghua , Shi Jianping
Published: November 2020

With the rapid development of integrated optics, bulky and curved traditional lenses cannot meet the requirements of on-chip optical systems. Alternatively, the metalenses based on the artificial subwavelength structure possess ultra-thin and lightweight characteristics, providing a potential candidate for on-chip optical systems. Nonetheless, most metalenses have a limited field-of-view (FOV) due to the prevalence of severe off-axis aberrations. In this work, we propose and design an on-chip metalens with wide FOV based on the quadratic phase. The metalens modulates the phase of the incident light with different lengths of gold nano-bands placed on the silicon-on-insulator substrate; thus, the quadratic distribution of the phase of the output light can be achieved by shifting the lengths of gold nano-bands and the output light is focused. The metalens can be focused on a large angle (∼120°, ranging from −60° to +60°). Furthermore, the metallic strips in the metalens are very thin with a thickness of 50 nm, which can be easily integrated into a chip. The monolithic metalens of broad FOV and ultrathin thickness will have great potential for applications in areas of sensing, imaging, and on-chip information processing.
Sublattice magnetization driven anomalous Hall resistance of FeCoGd amorphous films
Authors: Johnson Anthony , Negusse Ezana , Sharma Vinay , Anyumba Dan , McAlmont Deandre , Budhani Ramesh C.
Published: November 2020

Measurements of magnetization [M(H, T)] and anomalous Hall resistance [Rxy(H, T)] are performed over a broad range of magnetic field (H) and temperatures (T) on sputter deposited 10 nm thick films of (FeCo)1−xGdx. The Gd content (x) in the films was changed by varying the Gd source power from 20 W to 50 W, in steps of 5 W. The saturation magnetization (Ms) of these films at 300 K shows a distinct minimum for the source power of 40 W. Measurements of M(H) for the 40 W sample at several temperatures establish full compensation of the antiferromagnetically coupled magnetic sublattices of Gd and FeCo at Tcomp = 270 K ± 10 K. The approach to compensation is characterized by the emergence of perpendicular magnetic anisotropy (PMA) and a diverging coercive field. The Rxy (H) of this sample, as well as of those prepared at 30 W and 50 W, scales with M(H) at T > Tcomp and T < Tcomp. However, this scaling fails in the vicinity of Tcomp where the Rxy undergoes a sign reversal. Our analysis of these data in the framework of the existing models for Rxy(H, T) in ferrimagnets suggests that the role of spin disorder and its topological contribution to Rxy may be necessary to account for the observed behavior. A precise identification of Tcomp is also important to stabilize technologically useful non-trivial spin textures and PMA in these systems.
Acoustic levitation applied for reducing undesired lateral drift of magnetic helical microrobots
Authors: Xu Lei , Gong De , Chen Kehan , Cai Jun , Zhang Wenqiang
Published: November 2020

Magnetic helical microrobots can be effectively propelled via a controlled rotating magnetic field, and they have shown great potential in various biomedical applications. However, lateral drift caused by fluidic drag imbalance makes it hard for microrobots to achieve precise directional motion control, limiting their applications to perform practical tasks. Herein, we propose a reliable propulsion method to reduce the undesired lateral drift through levitating the microrobots from the substrate with the application of an acoustic field. We correlate the lateral drift with the total drag in the horizontal direction, which is mainly determined by the distance between the microrobots and the bottom. Theoretical analysis and simulation results suggest that a higher position from the substrate leads to a smaller lateral drift. We set up an acoustic levitation module to levitate the microrobots in fluids and an electromagnetic coil system to drive them. Experiments with and without acoustic levitation were carried out in contrast to analyze the lateral drift in motion under magnetic actuation. The results show that acoustic levitation can significantly reduce the undesired lateral drift of the helical microrobots, which would be a novel and effective strategy for further improving motion control.
Numerical investigation of thermocapillary and buoyancy convection in horizontal ribbon growth with lid-driven boundary
Authors: Sun Tao , Zhang Zhongqiang , Cheng Guanggui , Zhu Keqian , Xu Jiawei , Yuan Ningyi , Ding Jianning
Published: November 2020

The melt flow stability has a direct effect on crystal quality during the horizontal ribbon growth (HRG) process. The mixed convection in the HRG system includes thermocapillary convection, buoyancy convection, and the convection induced by the lid-driven boundary. In this study, the influences of relevant parameters such as Marangoni number, Rayleigh number, Biot number, and horizontal motion of the ribbon on flow and temperature fields have been analyzed using computational fluid dynamics. A thermal-fluid numerical model was developed by solving the Navier–Stokes and energy equations to obtain the flow, pressure, and temperature fields. The horizontal motion of the ribbon was assumed the lid-driven boundary. The results showed that the magnitude of the Marangoni number played a decisive role in the flow and temperature distribution inside the melt. In the case of a small Marangoni number, the increase in horizontal motion velocity of the ribbon was the main factor to induce convection in the melt, and the internal temperature distribution was carried out in a heat conduction mode. With the increasing Marangoni number, the thermocapillary convection was enhanced, and the convection induced by the ribbon motion was overwhelmed by the thermocapillary effect. Moreover, the increase in Biot number could reduce the temperature nonlinearity of the free surface. Particularly, the free surface temperature begins to oscillate as the Marangoni number is increased above a threshold. A larger Marangoni number could easily result in a temperature oscillation with a larger amplitude. The results indicated that the thermocapillary effect was more sensitive to temperature and flow oscillations, and should receive more attention.
Accuracy of XAS theory for unraveling structural changes of adsorbates: CO on Ni(100)
Authors: Diesen Elias , Rodrigues Gabriel L. S. , Luntz Alan C. , Abild-Pedersen Frank , Pettersson Lars G. M. , Voss Johannes
Published: November 2020

Studying surface reactions using ultrafast optical pump and x-ray probe experiments relies on accurate calculations of x-ray spectra of adsorbates for the correct identification of the spectral signatures and their dynamical evolution. We show that experimental x-ray absorption can be well reproduced for different binding sites in a static prototype system CO/Ni(100) at a standard density functional theory generalized-gradient-approximation level of theory using a plane-wave basis and pseudopotentials. This validates its utility in analyzing ultrafast x-ray probe experiments. The accuracy of computed relative core level binding energies is about 0.2 eV, representing a lower limit for which spectral features can be resolved with this method. We also show that the commonly used Z + 1 approximation gives very good core binding energy shifts overall. However, we find a discrepancy for CO adsorbed in the hollow site, which we assign to the significantly stronger hybridization in hollow bonding than in on-top.
Plate reader microrheology
Authors: Hawkins Robert F. , Duncan Gregg A.
Published: November 2020

In this work, we report the development of a simplified method to perform microrheology to rapidly assess soft materials. This approach uses fluorescence polarization and a plate reader format to measure the rotational diffusion of nanoparticles within a sample of interest. We have established that this technique can be used to characterize a range of soft materials based on the rotational diffusion of nanoparticles in materials with viscosities exceeding 100 cP. Using these fluorescence polarization-based measurements, we describe formalism that enables the estimation of viscosity in polymer solutions and gels composed of polyethylene glycol, hyaluronic acid, and Matrigel after accounting for the length-scale dependent effects of the polymer environment on the nanoparticle rotational diffusion. Using this analysis, we show that the plate reader microrheology measurements of viscosity are in reasonable agreement with traditional particle tracking microrheology. The use of a plate reader format allows this approach to be higher throughput, less technically challenging, and more widely accessible than standard macro- and micro-rheological methods, making it available to non-experts. This approach has potential applications in clinical settings where conventional rheological equipment may not be available to rapidly characterize patient-derived samples.
Ionization behavior of nanoporous polyamide membranes
Authors: Ritt Cody L. , Werber Jay R. , Wang Mengyi , Yang Zhongyue , Zhao Yumeng , Kulik Heather J. , Elimelech Menachem
Published: November 2020

Significance

Novel membrane processes and materials are needed to combat global water scarcity. The advancement of membrane materials for water purification processes such as desalination is hindered by our limited understanding of structure–property–performance relationships. We address this knowledge gap by elucidating the mechanisms which govern the ionization behavior of nanoporous polyamide films and their influence on membrane performance. Polyamide ionization is key to enhancing the separation efficiency of charged constituents in aqueous solutions. Our results illustrate that a large portion of the ionizable moieties in polyamide films remain uncharged during typical operation due to extreme confinement effects, thus going unutilized. Complete ionization of state-of-the-art polyamide membranes offers selectivity improvements that could markedly improve desalination process efficiency.
To hón ich imma insistieat
Authors: Flores Cristina , Rinke Esther , Wagner Claudia
Published: November 2020

This paper investigates syntactic variation in Hunsrückisch German, spoken in a language enclave in South Brazil over eight generations. The aim is to analyse whether this heritage language maintains asymmetric verb placement, i.e. verb-second in main clauses and verb-final in subordinate clauses, a prominent syntactic feature of German varieties. The analysis is based on a sample of 5000 sentences, produced by participants belonging to two generations of Hunsrückisch speakers: 10 older speakers (age: 55–75), and 10 younger adults (age: 25–40). The results show a general stability of asymmetric verb placement in both speaker groups, as has also been observed for other German language islands. This stability is a consequence of the active use of this minority language, not only by the older, but also by the younger generation of speakers, who are dominant in Brazilian Portuguese (BP). Variation to verb-second and verb-final order is conditioned by the same factors as in colloquial and dialectal German, and cannot be attributed to cross-linguistic influence from BP.
Ubiquitin chains earmark GPCRs for BBSome-mediated removal from cilia
Authors: Shinde Swapnil Rohidas , Nager Andrew R. , Nachury Maxence V.
Published: November 2020

Regulated trafficking of G protein–coupled receptors (GPCRs) controls cilium-based signaling pathways. β-Arrestin, a molecular sensor of activated GPCRs, and the BBSome, a complex of Bardet–Biedl syndrome (BBS) proteins, are required for the signal-dependent exit of ciliary GPCRs, but the functional interplay between β-arrestin and the BBSome remains elusive. Here we find that, upon activation, ciliary GPCRs become tagged with ubiquitin chains comprising K63 linkages (UbK63) in a β-arrestin–dependent manner before BBSome-mediated exit. Removal of ubiquitin acceptor residues from the somatostatin receptor 3 (SSTR3) and from the orphan GPCR GPR161 demonstrates that ubiquitination of ciliary GPCRs is required for their regulated exit from cilia. Furthermore, targeting a UbK63-specific deubiquitinase to cilia blocks the exit of GPR161, SSTR3, and Smoothened (SMO) from cilia. Finally, ubiquitinated proteins accumulate in cilia of mammalian photoreceptors and Chlamydomonas cells when BBSome function is compromised. We conclude that Ub chains mark GPCRs and other unwanted ciliary proteins for recognition by the ciliary exit machinery.
Gut microbiome stability and dynamics in healthy donors and patients with non-gastrointestinal cancers
Authors: Byrd Allyson L. , Liu Menghan , Fujimura Kei E. , Lyalina Svetlana , Nagarkar Deepti R. , Charbit Bruno , Bergstedt Jacob , Patin Etienne , Harrison Oliver J. , Quintana-Murci Lluís , Mellman Ira , Duffy Darragh , Albert Matthew L. ,   the Milieu Intérieur Consortium
Published: November 2020

As microbial therapeutics are increasingly being tested in diverse patient populations, it is essential to understand the host and environmental factors influencing the microbiome. Through analysis of 1,359 gut microbiome samples from 946 healthy donors of the Milieu Intérieur cohort, we detail how microbiome composition is associated with host factors, lifestyle parameters, and disease states. Using a genome-based taxonomy, we found biological sex was the strongest driver of community composition. Additionally, bacterial populations shift across decades of life (age 20–69), with Bacteroidota species consistently increased with age while Actinobacteriota species, including Bifidobacterium, decreased. Longitudinal sampling revealed that short-term stability exceeds interindividual differences. By accounting for these factors, we defined global shifts in the microbiomes of patients with non-gastrointestinal tumors compared with healthy donors. Together, these results demonstrated that the microbiome displays predictable variations as a function of sex, age, and disease state. These variations must be considered when designing microbiome-targeted therapies or interpreting differences thought to be linked to pathophysiology or therapeutic response.
Placental inflammasome signaling: Protection for mother and baby
Authors: Burgener Sabrina Sofia , Schroder Kate
Published: November 2020

The second trimester of pregnancy is traditionally viewed as an immunosuppressive state. Megli et al. (https://doi.org/10.1084/jem.20200649) change this paradigm, showing that midgestation induces inflammasome signaling in placental trophoblasts to promote fetal and maternal antimicrobial defense. The placenta is thus a dynamic immunological organ.
A knockout combination for MPN stem cells
Authors: Bywater Megan , Lane Steven W.
Published: November 2020

Myeloproliferative neoplasms (MPNs) are a group of blood cancers that are maintained by stem cell populations. In this issue of JEM, Dagher et al. (https://doi.org/10.1084/jem.20201268) combine arsenic and interferon α to deliver a knockout punch to MPN stem cells and provide new hope to cure patients with MPNs.
Impact of oxide gate electrode for ferroelectric field-effect transistors with metal-ferroelectric-metal-insulator-semiconductor gate stack using undoped HfO2 thin films prepared by atomic layer deposition
Authors: Choi Se-Na , Moon Seung-Eon , Yoon Sung-Min
Published: November 2020

Ferroelectric field-effect transistors (FETs) with a metal-ferroelectric-metal-insulator-semiconductor (MFMIS) gate stack were fabricated and characterized to elucidate the key process parameters and to optimize the process conditions for guaranteeing nonvolatile memory operations of the device when the undoped HfO2 was employed as ferroelectric gate insulator. The impacts of top gate (TG) for the MFM part on the memory operations of the MFMIS-FETs were intensively investigated when the TG was chosen as metal Pt or oxide ITO electrode. The ferroelectric memory window of the MFMIS-FETs with ITO/HfO2/TiN/SiO2/Si gate stack increased to 3.8 V by properly modulating the areal ratio between two MFM and MIS capacitors. The memory margin as high as 104 was obtained during on- and off-program operations with a program pulse duration as short as 1 μs. There was not any marked degradation in the obtained memory margin even after a lapse of retention time of 104 s at 85 °C and repeated program cycles of 10,000. These obtained improvements in memory operations resulted from the fact that the choice of ITO TG could provide effective capping effects and passivate the interfaces.
Mechanical properties of 2D blue phosphorus and temperature effect
Authors: Sun Yang , Wang Liya , Wang Chengyuan , Tang Chun
Published: November 2020

Blue phosphorus is an emerging 2D material that exhibits finite electronic band gap and may find promising applications in advanced semiconducting devices. Comparing to its allotrope, black phosphorus, mechanical properties of blue phosphorus have not been explored in detail. Here we report molecular dynamics simulations of mechanical responses of blue phosphorus under uniaxial tensile, biaxial tensile and shear loadings. It is found that blue phosphorus shows less anisotropic effect as compared to black phosphorus, the room temperature Young’s modulus is about 122.3 GPa and 121.6 GPa along armchair and zigzag directions, respectively, shear modulus is about 27.1 GPa and 28.6 GPa, respectively, along armchair and zigzag directions. Temperature effect on mechanical responses is also systematically studied within a range of 5–400 K. It is found that temperature reduces both Young’s modulus and fracture strain and fracture strength of blue phosphorus, owing to the interplay between thermal energy and strain energy applied to the models. Brittle fracture mode is found in blue phosphorus in all loading conditions, with varied crack nucleation and propagation modes. The role of strain rate on the mechanical properties is examined and found to systematically modify the ultimate stress and ultimate strain of BlueP. Structural details including bond length and bond angle variations to external strain are analyzed to gain deeper insights into the underlying mechanisms.
Porous nanotube networks of SnO2/MoO3@Graphene as anodes for rechargeable lithium-ion batteries
Authors: Zhou Hongyan , Jin Mengjing , Zhou Bojian , Zhao Jianguo , Han Weihua
Published: November 2020

We successfully fabricated composite porous nanotube networks of SnO2/MoO3@Graphene through electrospinning and used it as lithium-ion battery anodes. When the ratio of SnO2 to MoO3 is 1:1, the composite of SnO2/MoO3 delivers a high capacity of 560 mAh g−1 at 1 A g−1 after 300 cycles. The excellent electrochemical performance was attributed to the unique 3D porous nanotube network structure which could provide more transmission channels for Li+ ions and electrons, and provide more electrochemical reaction sites. The hybrid nanostructure can also weaken local stress and relieve volume expansion which contributes to the attractive cycling stability. Moreover, we added a small amount of graphene in the composite to improve the electrical conductivity, and the SnO2/MoO3@Graphene composite showed favorable electrochemical performance (798 mAh g−1 at 1 A g−1 after 300 cycles). Finally, electrospinning technology is a simple and efficient synthesis strategy, which can promote the preparation of different types of metal oxide composite materials and has good application prospects.
Structural, mechanical, electronic properties, and Debye temperature of quaternary carbide Ti3NiAl2C ceramics under high pressure: A first-principles study*
Authors: Jiang Diyou , Xiao Wenbo , Liu Sanqiu
Published: November 2020

Quaternary carbide Ti3NiAl2C ceramics has been investigated as a potential nuclear fusion structural material, and it has advantages in certain aspects compared with Ti2AlC, Ti3AlC2, and Ti3SiC2 structural materials. In this paper, quaternary carbide Ti3NiAl2C ceramics is pressurized to investigate its structural, mechanical, electronic properties, and Debye temperature. Quaternary carbide Ti3NiAl2C ceramics still maintains a cubic structure under pressure (0–110 GPa). At zero pressure, quaternary carbide Ti3NiAl2C ceramics only has three bonds: Ti–Al, Ni–Al, and Ti–C. However, at pressures of 20 GPa, 30 GPa, 40 GPa, 60 GPa, and 70 GPa, new Ti–Ni, Ti–Ti, Al–Al, Ti–Al, and Ti–Ti bonds form. When the pressure reaches 20 GPa, the covalent bonds change to metallic bonds. The volume of quaternary carbide Ti3NiAl2C ceramics can be compressed to 72% of its original volume at most. Pressurization can improve the mechanical strength and ductility of quaternary carbide Ti3NiAl2C ceramics. At 50–60 GPa, its mechanical strength can be comparable to pure tungsten, and the material changes from brittleness to ductility. However, the degree of anisotropy of quaternary carbide Ti3NiAl2C ceramics increases with the increasing pressure. In addition, we also investigated the Debye temperature, density, melting point, hardness, and wear resistance of quaternary carbide Ti3NiAl2C ceramics under pressure.
Design and verification of a broadband highly-efficient plasmonic circulator*
Authors: Han Jianfei , Zhen Shu , Wang Weihua , Han Kui , Li Haipeng , Zhao Lei , Shen Xiaopeng
Published: November 2020

Circulators play a significant role in radar and microwave communication systems. This paper proposes a broadband and highly efficient plasmonic circulator, which consists of spoof surface plasmon polaritons (SSPPs) waveguides and ferrite disks to support non-reciprocal mode coupling. The simulated performance of symmetrically designed circulator shows that it has an insertion loss of roughly 0.5 dB while the isolation and return loss is more than 12 dB in the frequency range of 6.0 GHz–10.0 GHz (relative bandwidth of 50%). Equivalent circuit model has been proposed to explain the operating mechanism of the plasmonic circulator. The equivalent circuit model, numerical simulations, and experimental results are consistent with each other, which demonstrates the good performance of the proposed plasmonic circulator.
Medium modifications of girth distributions for inclusive jets and Z
0+jets in relativistic heavy-ion collisions at the LHC *
Authors: Yan Jun , Chen Shi-Yong , Dai Wei , Zhang Ben-Wei , Wang En-Ke
Published: November 2020

In this paper, we investigate the medium modifications of girth distributions for inclusive jets and

tagged jets with a small radius (

) in Pb+Pb collisions with

TeV at the LHC. The partonic spectra in the initial hard scattering of elementary collisions are obtained by an event generator POWHEG+PYTHIA, which matches the next-to-leading order (NLO) matrix elements with parton showering, and the energy loss of a fast parton traversing the hot/dense QCD medium is calculated by Monte Carlo simulation within the higher-twist formalism of jet quenching in heavy-ion collisions. We present the model calculations of event normalized girth distributions for inclusive jets in p+p and Pb+Pb collisions at

TeV, which give good descriptions of ALICE measurements. It is shown that the girth distributions of inclusive jets in Pb+Pb are shifted to lower girth regions relative to those in p+p. Thus, the nuclear modification factor of girth distributions for inclusive jets is larger than unity at small girth regions and smaller than unity at large girth regions. This behavior results from softer fragments inside a jet as well as the fraction alteration of gluon/quark initiated jets in heavy-ion collisions. We further predict the girth distributions for

boson tagged jets in Pb+Pb collisions at

TeV and demonstrate that the medium modification on girth distributions for

tagged jets is less pronounced compared to that for inclusive jets because the dominant components of

tagged jets are quark-initiated jets.
Empirical dynamic modeling reveals climatic drivers in dynamics of bacillary dysentery epidemics in China
Authors: Wu Haisheng , Li Zhenjun , Yu Xiaolin , Zeng Qinghui , Lin Jiumin , Chen Yuliang , Ai Siqi , Guo Pi , Lin Hualiang
Published: November 2020

At present, there is still a lack of studies to address the dynamics underlying epidemics of bacillary dysentery (BD), with particular concern on the role of climatic drivers across different regions of a country or the world. The variability of climate domains, non-linear interactions, and covariations of climatic variables pose challenges for explaining the correlation between environment and BD and identifying causal climatic drivers. In this nationwide study involving 31 provincial capital cities in China, we used the empirical dynamic modeling (EDM), which is a framework for nonlinear time series analysis, to explore climate-driven patterns of BD. We first identified possible temperature (i.e. mostly via its seasonality) and relative humidity driving BD dynamics nationally. Then, we used the EDM to estimate the causal intensity of temperature and relative humidity in different latitudes. The results reveal that the combined nonlinear effect of them on BD may be nationwide, but this effect is concealed due to their high correlation in northern regions. We also found an approximately S-shaped relationship between temperature and BD at the population level; while the effects of relative humidity on BD are strongly dependent on environmental details, especially at temperatures above 0 °C. Temperature may potentially mediate and affect the effects of relative humidity on BD. This nationwide study provides a unified explanation for causal climate drivers of BD, regardless of the different climatic domains and epidemic patterns of BD in diverse cities.
Groundwater damages on the historic buildings of Cairo: the case of the medieval walls of Mokattam limestone.
Authors: Coppola M , Di Benedetto F , Garzonio CA , Pecchioni E , Santo AP
Published: November 2020

The conservation of historical buildings in Cairo represents a complex matter, influenced by several key factors such as the cultural context, the intrinsic features of a vast and heterogeneous architectural heritage and the environmental conditions. An Italian-Egyptian research group is working on the peculiarities of the monument conservation in old Cairo, concerning the material decay in relation to the anthropic and climatic factors and the pollution levels. Monument vulnerability levels strongly need to be identified and systematized to delineate adequate programs of control, management and intervention. One of the main topics developed is the study of the deterioration mechanisms of stone materials in medieval walls, connected to the capillary damp rising from the ground, common in Egypt, always accentuated by the combination with other factors. The research examines some historic buildings in different areas (El-Gamaleya, El Darb El Ahmar, Al Qarafah). The variety of materials has led to limiting the first phases of the study to the masonry materials, with special attention to the limestone blocks. The intersection of data collected on the field with those relating to underground water and environmental factors has allowed us to focus on some aspects of the problem. Some syntheses have been proposed on the main mechanisms affecting the studied material in situ and the necessary directions for further investigation have been identified. Our first results highlight the relationship existing between the environmental thermo-hygrometric excursions and the capillary water rising from the ground, which affect the evaporation speed, the imbibition levels and the crystallization of salts inside and on the rock surface. The studied rocks display intense weathering (decohesion, dissolution) due to a number of chemical and physical phenomena, responsible for a generalized decay of the mechanical properties of the original material. The observed widespread phenomena of carbonate sulphation also suggest the atmospheric contribution of particulate matter and polluting compounds. The mineralogical and physical characterization of the limestone allowed us to estimate its resistance to the decay processes.
Towards IoT monitoring of street-side monuments: the Florentine Dietrofront as a case study
Authors: Tarani Fabio , Manganelli del F´a Rachele , Riminesi Cristiano
Published: November 2020

The need for care often shown by ageing cultural heritage and the circumstantial lack of dedicated budget are increasingly calling for smart monitoring solutions to shift the maintenance paradigm from reactive-preventive to predictive. Monitoring artworks poses additional issues with respect to the more common industrial solutions, such as aesthetics, dealing with unusual materials, remote locations (archaeology), etc. In this scope, the “Dietrofront” statue in Florence, by artist Michelangelo Pistoletto, is an emblematic instance. Installed on a traffic roundabout, it comprises four travertine blocks, one of which hangs 5 m above the ground supported by a steel structure which has shown relevant symptoms of damage during the 2006 restoration works. During a later intervention, we seized the opportunity to equip the structure with a three IoT sensing devices, so as to monitor thermo-hygrometric conditions, inclination and vibrations of the structure. Various issues common to outdoor monuments have been faced, such as the need for visual non-intrusiveness and the unavailability of power supply. A small wireless sensor network was designed and installed, also exploiting an existing room inside the nearby mediaeval city gate. The network is fully solar-powered by photo-voltaic modules integrated on both the statue and the gate and not visible from the street. The data obtained have been analysed and compared to a simple lumped-parameters structural model, so as to estimate the relevance of traffic-induced vibration on the steel structure. The risk of water vapour condensation has also been assessed.
The Monumental Architecture of Po Ramé in Ninh Thuan Province, Vietnam
Authors: Van Son Quang , Noseworthy William B. , Minh Hung Ngo
Published: November 2020

This article aims to examine the architecture and characteristics of sculptures at the Po Ramé temple in Ninh Thuan province, Vietnam. There are the statues of Po Ramé himself, the queen Bia Su Can, the queen Bia Su Cih, a Nandin cow, a linga and a kut depicted more meaningfully. This provides clear assessment of preservation works that have been completed at the contemporary temple. In practice, those initiatives of the conservation effort figure out very first achievements that are definitely useful for improvement later on. Therefore, potential directions of preserving those heritages are proposed respectively from short, medium and long term in the future.
Energy Balance of a Continuous Structural Health Monitoring System based on Energy Harvesting
Authors: Stefano Clemente Carmine , Davino Daniele , Paolo Loschiavo Vincenzo
Published: November 2020

The Structural Health Monitoring (SHM) may be a relevant technique to monitor historical buildings, masonry, bridges, etc. It becomes even more important if it can be applied in a continuous way, once incorporated in a Wireless Sensor Network (WSN), being able to provide data in an automatic and endless mode without any human intervention. Of course, WSN needs a power source, a role prevalently held by batteries. However, this solution has several issues: it is not eco-friendly and needs a periodic replacement hence increasing costs and reducing the SHM spread. The Energy Harvesting (EH) is a very promising technique to supply WSN. It converts the environmental energy into electrical energy allowing its local accumulation, within the sensor node, in supercapacitor or rechargeable batteries. Anthropic environments are plenty of energy (photovoltaic, kinetic, etc) but this is a non-continuous source and then an energy balance could highlight the suitability of an EH solution. This work is aimed to present a clear picture of EH for SHM by considering all the previous elements in the context of cultural heritage. The result is the definition of specific applications in which those WSNs, based on EH, could be competitive with respect to more traditional technologies.
Investigation on the use of hygrothermal modelling for paper collections
Authors: Verticchio E. , Frasca F. , Cornaro C. , Siani A.M.
Published: November 2020

Dynamic simulation is increasingly adopted in the preventive conservation of cultural heritage as an advanced method to investigate strategies for mitigating the climate-induced degradation. The conservation of paper collections is strongly interrelated with the relative humidity of the air, as organic-hygroscopic materials act as buffers on relative humidity fluctuations while being vulnerable to moisture-induced damage. In the dynamic simulation of the microclimate within library and archival storage facilities, it is thus fundamental to include the hygrothermal interaction between the building and its hygroscopic content. The hygroscopic behaviour of paper collections can be modelled by hygrothermal tools such as those of the HAM-family (Heat, Air and Moisture), used to simulate simultaneous heat and mass transfers through porous envelope materials. This research aims at investigating the use of the HMWall model coupled with the software IDA ICE (Indoor Climate and Energy) to simulate of the 1-D heat and moisture transfer through a single wall made of paper. A literature survey was carried out to collect the available hygrothermal properties of modern and historical papers. Sensitivity analysis was used to identify the most relevant hygrothermal parameters in the simulation of moisture gradients across the paper wall. Moreover, the number of sub-layers in the paper wall model was found to significantly affect the internal distribution of moisture gradients. The use of the HMWall model was then tested in the simulation of the hygroscopic behaviour of a single paper wall in both steady-state and transient conditions. Finally, a simplified model able to preserve the accuracy of the results was proposed with the purpose of reducing the computation effort that a high-resolution model could involve if implemented in whole buildings. This study represents the first step towards the application of the HMWall model for the simulation of the indoor climate of library repositories.
The study of Severini’s wall paintings in Switzerland: how to manage heterogeneity of data and team members?
Authors: Russo Jacopo , Luppichini Stefania , Stefani Chiara , Piqué Francesca
Published: November 2020

A data management system has been created for the 4-year research project to manage the results of the study of the wall paintings by Gino Severini in fve Swiss churches (https://www.stluc.ch/). The project involves art historical and scientifc research to investigate painting materials and techniques. The data produced by the multidisciplinary team is vast and varied and is archived in a database (Db) designed to act both as a fle repository and as an exchange platform. The documentation is based on a 3D survey carried out with stereo photogrammetry and 3D laser scanning. The Db contains data sheets describing ‘entities’ which can be physical objects with cultural signifcance (e.g. a wall painting) or the structures containing them (e.g. the church). It is possible to establish hierarchical relationships between entities, e.g. the church, the apse, one of the paintings in the apse etc.. There are no limits to the number of sub-entities that can be created and nested one in the other recursively (as folders and sub-folders). In this way, the Db structure can register any type of activity involving the heritage by collecting all the documentation and data produced at all levels. Data includes vector drawings that are recorded as tables in the Db and can be visualized as maps. These allow the linking of any fle and data sheet, providing immediate access to information starting from the map. Data entry is carried out by the professionals creating it, i.e. the project team members. The system has a client-server architecture based on PostgreSQL with the PostGIS extension server side and is currently accessed by the team through a front-end application based on Access and a cartographic application based on QuantumGIS. The challenge and the innovation of this system is to allow professionals from the diferent disciplines within the research groups to safely enter and access data working with sophisticated profled privileges while the project is on-going. Once the project is completed, in an ‘Open science’ framework, data will be accessible to common users and to specialists. The Severini project is in its second year and currently two of the fve churches have been studied. The paper will discuss the challenges encountered, the solutions developed, and the potentiality and fexibility of the data model designed.
A Preliminary study on material properties of the Zerzevan Castle, Turkey
Authors: Dursun F , Coşkun A
Published: November 2020

Zerzevan is a recently discovered castle, situated on a rocky hill in the province of Diyarbakır, southeastern Turkey. Like many other Medieval defensive artifacts, Zerzevan Castle has also erected to protect the site against the incursions of enemies and to dominate the land. Zerzevan Castle, as a former military base of the Roman Empire, consists of such remains as churches, tombs observation towers, cisterns, arsenal, canals and city walls. The archaeological excavations conducted in the site revealed the existence of various underground structures, among them a temple of Mithraism, a mystery religion. The temple is considered as the first and unique Mithraeum located on the eastern border of the Roman Empire. The castle has been constructed by employing natural stones. Similar to that of the stone artifacts around the world, the Zerzevan Castle has also suffered from stone deterioration and stability problems. The present study aims to characterize stone used in the Zerzevan Castle as a building material. The study also aims to characterize the provenance of the stone material utilized in the monuments of that archaeological site. For this purpose, samples were collected from the building façade and stone quarry located on the site. The samples then used to determine their petrographic, chemical and some of the physico-mechanical properties. The preliminary results demonstrate that the stone employed in the construction of the Castle is calcitic dolomite. Moreover, the great similarities in chemical compositions of the samples collected from the building and the quarry indicate that the stone material employed in the construction was most probably extracted from the nearby quarries.
Comparison between ammonium phosphate and nanolimes for render consolidation
Authors: Masi G , Sassoni E
Published: November 2020

In this study, a systematic comparison is presented between ammonium phosphate and commercial nanolimes for the conservation of lime-based renders. Such comparison is very significant, considering that nanolimes are the most widely used inorganic consolidant commonly applied onto plasters, renders and frescoes. Specimens made of slaked lime and siliceous sand were prepared, by applying the fresh mortar onto a solid brick substrate. After curing for 4 months, samples were consolidated by (i) an aqueous solution of diammonium hydrogen phosphate and (ii) commercial nanolimes. The effects of the treatments were evaluated in terms of composition and morphology of the new phases, effectiveness (ultrasounds and scotch tape test) and compatibility (color change and water absorption). The results of the study confirm the high potential of the phosphate treatment, able to provide higher mechanical consolidation in a shorter time (24 hours, instead of at least 4 weeks for nanolimes), while being equally compatible from the aesthetical and physical point of view.
Digital Experience of the Work of Vitruvius and Leonardo
Authors: Brillarelli S , Callegari M , Carbonari L , Clini P
Published: November 2020

On the celebrations for the 500th year since Leonardo da Vinci’s death, the city of Fano (I) organized an exhibition on the works of Leonardo to put in evidence the influence of the previous studies of Vitruvius, who left in Fano remarkable signs of his talent. Among the original drawings that were shown, some sheets showed the design of three machines originally described by Vitruvius and then re-interpreted by Leonardo: the water clockwork, the ballista and the odometer. The Authors realized a digital reconstruction of such works, with the aim to let the visitors of the exhibition understand the operation of the machines but also to study the differences in the concepts, to explore their feasibility and to assess their possible performance.
Service life prediction of building components in the times of climate change
Authors: Loli A , Bertolin C , Kotova L
Published: November 2020

Buildings components and assemblies are prone to decay over time due to the inherent characteristics of the materials, environmental conditions and operational use of them. For this reason, it is very important to know the right time and type of maintenance and adaptation interventions that need to be applied to the specific compounds. The answer to the above issue can be given through the service life prediction (SLP) of the components by using standardized calculation methods.

In historic buildings, the process of SLP takes significant importance because these buildings hold non-renewable cultural heritage value and therefore, the interventions should be performed in a way that preserves the original material and value while enhancing the service life. Nowadays, for such buildings that are predicted to live for centuries, the SLP needs to be corrected by considering the effects of climate change in the construction materials.

The paper presents an overview of the application of the well-known factor method in the estimation of the serviceability of the building components, with a special focus on historic buildings impacted by climate change. The technical compatibility, economic viability, use of the building and the indoor/outdoor environments are considered during the assessment of the service life which is strictly linked with the level of decay. It gives a short explanation of the factors that constitute the method by including the effects of climate change and an example of application to a specific case study in Norway.
Augmented reality for cultural heritage: a new dimension for the perceptual knowledge
Authors: Fistola R , Rastelli A , Pham C , Amore F O
Published: November 2020

The paper presents an innovative way of conceiving the museum exhibit particularly useful in those territorial contexts in which it is possible to simultaneously show the place of discovery of the exhibit n (contextualizing it through the virtual reproduction of the historical scenario) and the find itself adding to this the possibility of narrating one’s own history and characteristics. The entire meta-project is designed for the Pietraroja site in the province of Benevento which would acquire considerable cultural interest thanks to the potential of augmented and mixed reality. The main idea is to use this new technology to involve the user (observer) by rebuilding the environment and the peculiarities of the finds. The perception of the augmented elements will be possible by design a specific application for smartphone that everyone gets in its pocket.
Standard Cataloguing of Augmented Objects for a Design Museum
Authors: Patti Isabella
Published: November 2020

Demo-ethno-anthropological assets belonging to the cultural heritage are not “autonomous” but represent the nodes of a complex system of relations. Their narration – for the purposes of knowledge and cultural diffusion – cannot transcend this relational dimension that recognises an enormous potential for development in the application of digital culture and in the prudent use of augmented reality. In the perspective of a design museum, it is therefore necessary to accompany each artefact / asset with a digital matrix that provides accurate information in relation to its critical interpretation. The exposure of an augmented object, in fact, allows to read better its use and social value along specific interpretative lines. This essay summarizes the study of a new type of archive – the animated archive of cultural materials – intended as a system of standard cataloguing of objects for a museum on design. Moreover, it is based on the critical comparison between the contribution of ludic humanism and the augmented narrative. This comparison is necessary because the rhetorical and design systems of the playful narrative offers interesting information for the realization of virtual – and non – exhibits, since the type of involvement and the environment required by the spectator is very similar; but above all because games are an important experimentation of interactive models of learning and cultural production.
Cultural Control Room: CETRA addresses and exploits the IoT to innovate Cultural Heritage promotion
Authors: Habibi Minelli Sam , Ongaro Paolo , Ugoletti Daniele , Saccoccio Rubino , Maresca Simona
Published: November 2020

CETRA - Cultural Equipment with Transmedial Recommendation Analytics - is a comprehensive combination of IoT (Internet of Things), machine learning, recommendation, content adaptivity and Big Data Analytics applications, in line with a new concept of transmediality, aiming to close the gap between tourist-cultural promotion requirements and the need to deliver personalized, dynamic and accessible heritage content to users. The paper will describe the research results related to new technological solutions addressing the heritage experience in an era of: massive content production and massive participation by visitors who demand personalized involvement.
Challenging multi-sensor data models and use of 360 images. The Twelve Months Fountain of Valentino park in Turin.
Authors: Teppati Losè L , Sammartano G , Chiabrando F , Spanò A
Published: November 2020

The cultural heritage and the ways in which it is today studied and analysed as well as disseminated and enhanced for the purposes of conservation, requires high attention in the choice of 3D survey and modelling methods. This manuscript investigates the possible integrations and fusion of methods and data, among the vast availability of image and range based systems, especially in the sphere of low cost techniques, which in the context of heritage documentation makes the whole and complex process of conservation more sustainable. The investigation is carried out on a historical fountain that includes a quantity of cultural values and the need to document its context: its location in the historical Valentino of Turin park, its architectural values and the geometry of the complex typically related to the tastes of the late XIX century that consist in the extreme refinement of the statuary complexes and the underground portion with the technological equipment for the activation of the water games. Basically, it will be possible to appreciate solved issues and permanent criticalities derived from the integration of close range and UAV photogrammetry techniques in addition to the LiDAR survey, both classic from a fixed position, and in the portable scanner mode, based on SLAM technology.