Research

18 pages, 3921 KiB

Open AccessArticle

Comparison of Aluminum Alloys from Aircraft of Four Nations Involved in the WWII Conflict Using Multiscale Analyses and Archival Study

by Toufa Ouissi, Gilles Collaveri, Philippe Sciau, Jean-Marc Olivier and Magali Brunet

Heritage 2019, 2(4), 2784-2801; https://doi.org/10.3390/heritage2040172 - 22 Nov 2019

Cited by 6 | Viewed by 5168

Abstract

Aluminum alloys are very interesting witnesses of industrial and technical development. The first ever developed was Duralumin, a light metal with good mechanical properties. In the 1930s, the rise of nationalism stimulated research and development, generating various aluminum alloys. This work reports the [...] Read more.

Aluminum alloys are very interesting witnesses of industrial and technical development. The first ever developed was Duralumin, a light metal with good mechanical properties. In the 1930s, the rise of nationalism stimulated research and development, generating various aluminum alloys. This work reports the comparison of two versions of aluminum alloys, which were found in collected parts of WWII crashed aircraft from four nations: a Messerschmitt Bf 109 (DE), a Dewoitine D.520 (FR), and a P-51 Mustang (USA) and an Avro Lancaster (United Kingdom). The first version of alloy with magnesium content below or equal to 1 wt.% and the second version with higher magnesium content (1.5 wt.%), were identified as respectively AlCuMg1, AlCuMg2 in Germany; Duralumin, Duralumin F.R. in France; Hiduminium DU Brand, Hiduminium 72 in the UK and 17S, 24S in the USA. This study uses a multiscale approach based on historical research complimented by laboratory analyses of materials directly collected on the crashed aircraft. It allows a comparison and a better knowledge of the alloys used in each nations: their chemical composition, designations, microstructure, and mechanical properties are investigated. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

20 pages, 6598 KiB

Open AccessArticle

A Painter in the Shadow: Unveiling Conservation, Materials and Techniques of the Unknown Luso-Flemish Master of Lourinhã

by Vanessa Antunes, Vitor Serrão, Sara Valadas, António Candeias, José Mirão, Ana Cardoso, Marta Manso and Maria L. Carvalho

Heritage 2019, 2(4), 2725-2744; https://doi.org/10.3390/heritage2040169 - 24 Oct 2019

Cited by 2 | Viewed by 3011

Abstract

The painting collection of Santa Casa da Misericórdia da Lourinhã is amongst Portugal’s most notable and scarcely best-known cultural heritage. The artistic interest of this pictorial group, besides the advanced state of degradation of a number of the paintings, together with the ruined [...] Read more.

The painting collection of Santa Casa da Misericórdia da Lourinhã is amongst Portugal’s most notable and scarcely best-known cultural heritage. The artistic interest of this pictorial group, besides the advanced state of degradation of a number of the paintings, together with the ruined circumstances of the building accommodating the collection, today in reconstruction, were the key reasons for this study. Thermo-hygrometric measurements were carried out. A multianalytical methodology incorporating micro-X-ray diffraction (µ-XRD), energy-dispersive X-ray fluorescence spectroscopy (EDXRF), scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS), micro-Raman spectroscopy (µ-Raman), micro-Fourier transform infrared spectroscopy (µ-FTIR) has been followed for the study. These analyses were complemented by infrared photography (IRP) and reflectography (IRR), allowing the study of the underdrawing technique. The results of this study were compared with previous ones of the painter’s workshop and important distinctions and similarities were found within the materials and techniques used. This analysis methodology on materials contributes to safeguarding and the ensuing community awareness of this cultural heritage in danger. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

13 pages, 8545 KiB

Open AccessArticle

Basic Protocol for On-Site Testing Consolidant Nanoparticles on Stone Cultural Heritage

by Javier Becerra, Ana Paula Zaderenko and Pilar Ortiz

Heritage 2019, 2(4), 2712-2724; https://doi.org/10.3390/heritage2040168 - 10 Oct 2019

Cited by 5 | Viewed by 3212

Abstract

Currently the application of consolidants based on nanoparticles is common practice among restorers. Consolidants should not modify the properties of original materials according to international recommendation, which requires previous studies to decide the optimal option. The selection must be based on empirical results, [...] Read more.

Currently the application of consolidants based on nanoparticles is common practice among restorers. Consolidants should not modify the properties of original materials according to international recommendation, which requires previous studies to decide the optimal option. The selection must be based on empirical results, and not only in the expertise of the restorer, because the consolidant’s effectiveness is influenced by its own properties and other factors such as the characteristics of the artwork (elemental composition, porosity, texture, etc.) and its context (temperature, relative humidity, etc.). Moreover, new protocols must be sustainable and compatible with on-site restoration. A new protocol to test consolidant nanoparticles has been designed and assessed. This is based on easy trials and low-cost techniques—digital microscope, colorimeter, peeling test and ultrasound—that could be employed by restorers in situ. In this paper, different consolidant nanoparticles were tested on stones from two historical quarries. The first treatment was SiO₂ nanoparticles, and the second, a new nanocomposite of Ca(OH)₂ and ZnO quantum dots that allows us to measure penetration depth easily and discern the treated areas under UV lights. This second treatment was the best option for the studied stones, validating the protocol designed for the choice of consolidants. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

13 pages, 3289 KiB

Open AccessArticle

Study of Iron Gall Inks, Ingredients and Paper Composition Using Non-Destructive Techniques

by Victoria Corregidor, Rita Viegas, Luís M. Ferreira and Luís C. Alves

Heritage 2019, 2(4), 2691-2703; https://doi.org/10.3390/heritage2040166 - 24 Sep 2019

Cited by 25 | Viewed by 7137

Abstract

Old manuscripts are among the most important elements of the cultural and historical heritage of ancient knowledge. Unfortunately, many of them suffer from degradation, mostly those written with iron gall inks. In the present work, a study using non-destructive techniques was designed with [...] Read more.

Old manuscripts are among the most important elements of the cultural and historical heritage of ancient knowledge. Unfortunately, many of them suffer from degradation, mostly those written with iron gall inks. In the present work, a study using non-destructive techniques was designed with the aim of analyzing the elemental composition and structural characteristics of iron gall inks, reproduced in laboratory, paper and their interaction when the ink is deposited on paper, inducing the paper degradation. Proton induced X-ray emission, X-ray diffraction and Fourier-transform infrared spectroscopy provided the elemental and structural information, and photography under infrared (IR) and ultraviolet (UV) light allowed the differentiation between manufactured inks. Results show that the first step of inked paper deterioration is due to acid-hydrolysis of the cellulose and the presence of reactive Fe(II) species by reducing the crystallinity index of the paper, which is affected depending on the ink recipe and the starting raw materials. These results will be useful to future studies on ancient documents written with iron gall inks, which suffer deterioration due to ink corrosion, and to differentiate between the different paper degradation mechanisms. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

13 pages, 3615 KiB

Open AccessArticle

Image-Based Quantitative Analysis of Foxing Stains on Old Printed Paper Documents

by Gyuho Kim, Jung Gon Kim, Kitaek Kang and Woo Sik Yoo

Heritage 2019, 2(3), 2665-2677; https://doi.org/10.3390/heritage2030164 - 18 Sep 2019

Cited by 29 | Viewed by 3850

Abstract

We studied the feasibility of image-based quantitative analysis of foxing stains on collections of old (16th–20th century) European books stored in the Rare Book Library of the Seoul National University in Korea. We were able to quantitatively determine the foxing affected areas on [...] Read more.

We studied the feasibility of image-based quantitative analysis of foxing stains on collections of old (16th–20th century) European books stored in the Rare Book Library of the Seoul National University in Korea. We were able to quantitatively determine the foxing affected areas on books from their photographs using a newly developed image processing software (PicMan) including cultural property characterization applications, specifically. Dimensional and color analysis of photographs were successfully done quantitatively. Histograms of RGB (red, green, blue) pixels of photographs clearly showed the change in color distribution of foxing stains compared to the other areas of the photographs. Several sample images of quantitative measurement of foxing stains and virtually restored images were generated to provide easy visual inspection and comparison between restored images and the original photographs. Image quality, resolution, and digital file format requirements for quantitative analysis are described. Image-based quantitative analysis of foxing stains on paper documents are found to be very promising towards automation for objective characterization of photographs of cultural properties. This technique can be used to create a cultural property digital database. Quantitative and statistical analysis techniques can be introduced to monitor the effect of storage and conservation environment on the cultural properties. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

13 pages, 2425 KiB

Open AccessArticle

Mineralogical Characterization and Firing Temperature Delineation on Minoan Pottery, Focusing on the Application of Micro-Raman Spectroscopy

by Ioannis E. Grammatikakis, Evangelos Kyriakidis, Konstantinos D. Demadis, Aurelio Cabeza Diaz and Laura Leon-Reina

Heritage 2019, 2(3), 2652-2664; https://doi.org/10.3390/heritage2030163 - 17 Sep 2019

Cited by 12 | Viewed by 3244

Abstract

Ceramic objects in whole or in fragments usually account for the majority of findings in an archaeological excavation. Thus, through examination of the values these items bear, it is possible to extract important information regarding raw materials provenance and ceramic technology. For this [...] Read more.

Ceramic objects in whole or in fragments usually account for the majority of findings in an archaeological excavation. Thus, through examination of the values these items bear, it is possible to extract important information regarding raw materials provenance and ceramic technology. For this purpose, either traditional examination protocols could be followed, focusing on the macroscopic/morphological characteristics of the ancient object, or more sophisticated physicochemical techniques are employed. Nevertheless, there are cases where, due to the uniqueness and the significance of an object of archaeological value, sampling is impossible. Then, the available analytical tools are extremely limited, especially when molecular information and mineral phase identification is required. In this context, the results acquired from a multiphase clay ceramic dated on Early Neopalatioal period ΜΜΙΙΙA-LMIA (1750 B.C.E.–1490 B.C.E.), from the Minoan Bronze Age site at Philioremos (Crete, Greece) through the application of Raman confocal spectroscopy, a non-destructive/ non-invasive method are reported. The spectroscopic results are confirmed through the application of X-ray microdiffraction and scanning electron microscopy coupled with energy dispersive X-ray spectrometry. Moreover, it is demonstrated how it is made possible through the application of micro-Raman (μRaman) spectroscopy to examine and collect crucial information from very small inclusions in the ceramic fabric. The aim of this approach is to develop an analytical protocol based on μRaman spectroscopy, for extracting firing temperature information from other ceramic finds (figurines) where due to their uniqueness sampling and analyses through other techniques is not possible. This information can lead to dating but also to firing kiln technology extrapolations that are very significant in archaeology. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

12 pages, 4368 KiB

Open AccessArticle

Multiscale Study of Interactions Between Corrosion Products Layer Formed on Heritage Cu Objects and Organic Protection Treatments

by Maëva L’héronde, Muriel Bouttemy, Florence Mercier-Bion, Delphine Neff, Emilande Apchain, Arnaud Etcheberry and Philippe Dillmann

Heritage 2019, 2(3), 2640-2651; https://doi.org/10.3390/heritage2030162 - 16 Sep 2019

Cited by 6 | Viewed by 2645

Abstract

In the framework of the protection of copper objects exposed to atmospheric corrosion, different solutions are envisaged, among them carboxylate treatments (HC₁₀). In this study, an analytical approach based on complementary techniques from micrometer to nanometer scale (μRS, SEM-EDS, SAM) is [...] Read more.

In the framework of the protection of copper objects exposed to atmospheric corrosion, different solutions are envisaged, among them carboxylate treatments (HC₁₀). In this study, an analytical approach based on complementary techniques from micrometer to nanometer scale (μRS, SEM-EDS, SAM) is used to describe the properties of the corrosion products layer (CPL) and determine the penetration depth of the HC₁₀ protection treatment inside the CPL of copper samples issued from the roof of the Saint Martin church in Metz. The CPL consists in a thick brochantite layer (20 to 50 μm), mainly composed of Cu₄SO₄(OH)₆, on top of a thinner (1 to 5 μm thick) cuprite layer, Cu₂O, acting as a natural corrosion barrier on the metal. Application of the organic treatment is implemented by immersing the corroded samples in HC₁₀ solution, consistent with future requirements for large scale applications. Even for short-term duration (one minute), the HC₁₀ treatment penetrates to the cuprite/brochantite interface, but Cu(C₁₀)₂ precipitate is only detected locally, whereas for a longer immersion of thirty minutes, it is present in higher proportions in the whole brochantite layer, filling the pores, up to the cuprite/brochantite interface. Cu(C₁₀)₂ acts as a second inner barrier and prevents liquid infiltration. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Graphical abstract

15 pages, 6920 KiB

Open AccessArticle

Nanotechnology in Roman Opaque Red Glass from the 2nd Century AD. Archaeometric Investigation in Red Sectilia from the Decoration of the Lucius Verus Villa in Rome

by Mario Bandiera, Patrice Lehuédé, Marco Verità, Luis Alves, Isabelle Biron and Marcia Vilarigues

Heritage 2019, 2(3), 2597-2611; https://doi.org/10.3390/heritage2030159 - 03 Sep 2019

Cited by 13 | Viewed by 4252

Abstract

This work aims to characterise the chemical composition of Roman opaque red glass sectilia dated to the 2nd century A.D and to shed light on Roman glassmaking production of different shades of red, from red to reddish-brown. Due to the lack of technical [...] Read more.

This work aims to characterise the chemical composition of Roman opaque red glass sectilia dated to the 2nd century A.D and to shed light on Roman glassmaking production of different shades of red, from red to reddish-brown. Due to the lack of technical historical sources for this period many questions about technological aspects still remain. In this project a multi-disciplinary approach is in progress to investigate the red glass sectilia with several red hues from the Imperial Villa of Lucius Verus (161–169 A.D.) in Rome. First, colorimetric measurements were taken to identify the various red hues. The second step was chemical characterization of the samples and the identification of crystalline colouring phases. Particle Induced X-Ray Emission (PIXE) analysis was used to investigate the chemical composition of these glass samples, while the crystalline phases were identified by Raman Spectroscopy and Scanning Electrons Microscope with Energy Dispersive X-ray Spectrometry (SEM-EDS). Using SEM-EDS nanoparticles were detected as a colouring agent, the chemical composition and the morphology of which has been studied in depth. This information has been compared with the colorimetric analysis to establish any correlation with the different colour hues. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

18 pages, 3517 KiB

Open AccessArticle

The Chiaravalle Cross: Results of a Multidisciplinary Study

by Daniela Di Martino, Giulia Benati, Roberto Alberti, Sandro Baroni, Carlo Bertelli, Franco Blumer, Letizia Caselli, Roberta Cattaneo, Costanza Cucini, Fabio D’Amico, Tommaso Frizzi, Elisabetta Gagetti, Michele Gironda, Lisa Greggio, Lorenzo Lazzarini, Maya Musa, Enrico Perelli Cippo, Maria Pia Riccardi and Giuseppe Gorini

Heritage 2019, 2(3), 2555-2572; https://doi.org/10.3390/heritage2030157 - 30 Aug 2019

Cited by 3 | Viewed by 3856

Abstract

The Chiaravalle Cross, a masterpiece of Mediaeval goldsmithery, went under restoration in 2016. This was a unique opportunity to undertake an in-depth multidisciplinary study. Several issues were addressed, as for example the chronology of the Cross, lacking any official document about it. The [...] Read more.

The Chiaravalle Cross, a masterpiece of Mediaeval goldsmithery, went under restoration in 2016. This was a unique opportunity to undertake an in-depth multidisciplinary study. Several issues were addressed, as for example the chronology of the Cross, lacking any official document about it. The scientific investigations included in situ and laboratory measurements, and the analyses, part of a multidisciplinary protocol, completely characterized the gemstones adorning the Cross, the cameos, the gold, silver, jasper and glass parts, to derive indications on their provenance, authenticity and dating issues. All the results were shared with the whole collaboration of experts, which included art historians, a restorer, a conservator, a scholar in ancient glyptic, gemologists, archaeometallurgists, physicists and scientists in a very fruitful exchange of knowledge. This work is an example of a real multidisciplinary research, gathering good practices in the study of a complex piece of art. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

18 pages, 13426 KiB

Open AccessArticle

Magic Lantern Glass Slides Materials and Techniques: The First Multi-Analytical Study

by Beatriz Rodrigues, Ângela Santos, Maria J. Melo, Vanessa Otero and Márcia Vilarigues

Heritage 2019, 2(3), 2513-2530; https://doi.org/10.3390/heritage2030154 - 29 Aug 2019

Cited by 4 | Viewed by 5357

Abstract

This paper presents the first systematic investigation of hand-painted magic lantern glass slides using multi-analytical techniques combined with a critical analysis of historical written sources of the painting materials and techniques used to produce them. The magic lantern was an optical instrument used [...] Read more.

This paper presents the first systematic investigation of hand-painted magic lantern glass slides using multi-analytical techniques combined with a critical analysis of historical written sources of the painting materials and techniques used to produce them. The magic lantern was an optical instrument used from the seventeenth to the twentieth century that attained great success and impact on the entertainment industry, science, religion, and advertisement industry. The glass, colorants, and organic media of five magic lantern slides from the Museum of Natural History and Science of the University of Lisbon were studied. By means of energy-dispersive X-ray fluorescence spectrometry, the glass was characterized and the oxide quantification unveiled that the glass substrate was possibly produced between 1870 and 1930. Ultraviolet-Visible, Raman and Fourier transform infrared spectroscopies allowed the characterization of the colorants: Prussian blue, an anthraquinone red lake pigment of animal origin (such as cochineal), an unidentified organic yellow, and carbon black. The remaining colors were achieved through mixtures of the pure pigments. Infrared analysis detected a complex fingerprint in all colors, nevertheless, a terpenoid resin such as shellac was identified. Metal carboxylates were also detected, contributing to the assessment of the state of conservation of the paints. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

18 pages, 3063 KiB

Open AccessCommunication

Glass Crystal Models: A First Approach to a Hidden Treasure of Teaching and Scientific Heritage

by Carolina Peixe, Conceição Casanova, Joana Lia Ferreira and Inês Coutinho

Heritage 2019, 2(3), 2495-2512; https://doi.org/10.3390/heritage2030153 - 29 Aug 2019

Cited by 2 | Viewed by 2774

Abstract

Glass crystal models arrived in Portugal around the late 19th century, when high schools, universities, and polytechnics were gradually provided with teaching collections to support science education. Therefore, they are an important material evidence of teaching methodologies of mineral and geology science in [...] Read more.

Glass crystal models arrived in Portugal around the late 19th century, when high schools, universities, and polytechnics were gradually provided with teaching collections to support science education. Therefore, they are an important material evidence of teaching methodologies of mineral and geology science in the 20th century. The Passos Manuel high school in Lisbon, owns a significant collection of scientific heritage, currently on a long-term loan at the National Museum of Natural History and Science and the University of Lisbon, which includes a set of 98 glass crystal models. Besides glass, these models are composed by adhesives, paper, cardboard, textile threads, paper/textile adhesive tapes, and metal nuts and screws. Also, they show several levels of intervention and different conservation states. In this paper, the first results of a multi-analytic approach to chemically characterize these objects’ material composition will be presented. Characterization was done based on portable equipment (pXRF), or by collecting small samples further analyzed using optical microscopy and FTIR-ATR techniques. This study allowed for a first distinction between original materials from the old repairs; to develop a more accurate assessment of the conservation condition; and finally, as one of the main aims of this work, to determine preventive conservation measures in order to better preserve these cultural objects. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

15 pages, 6768 KiB

Open AccessArticle

Multi-Scale Investigation of Body-Glaze Interface in Ancient Ceramics

by Marie Godet, Gauthier Roisine, Emmie Beauvoit, Daniel Caurant, Odile Majérus, Nicolas Menguy, Olivier Dargaud, Anne Bouquillon and Laurent Cormier

Heritage 2019, 2(3), 2480-2494; https://doi.org/10.3390/heritage2030152 - 28 Aug 2019

Cited by 4 | Viewed by 3435

Abstract

Bernard Palissy is a French Renaissance ceramist renowned for his masterpieces called Rustiques Figulines on which dozens of glazes of different chemistries (and thus firing behaviors) coexist harmoniously. This study aims at gathering information on the master procedure -never revealed- by investigating the [...] Read more.

Bernard Palissy is a French Renaissance ceramist renowned for his masterpieces called Rustiques Figulines on which dozens of glazes of different chemistries (and thus firing behaviors) coexist harmoniously. This study aims at gathering information on the master procedure -never revealed- by investigating the body-glaze interface region (focusing on iron-colored honey transparent glaze-white body system). Optical and electron microscopies including transmission electron microscopy (TEM) are used to characterize the micro and nanostructure of both archaeological and replicas interfaces elaborated in controlled conditions (firing time, cooling rate, addition of Al in the glazing mixture). Both types of interfaces are comparable: a modified paste area from which are growing a relatively continuous layer of interfacial crystals identified as lead feldspars (K,Ca)PbAl₂Si₂O₈ micro-sized single-crystals incorporating mullite 3Al₂O₃.2SiO₂ nano-sized single-crystals. Modification of the firing parameters and removal of Al from the glazing mixture change essentially the interface extension and the micro-crystals morphology. By comparing archaeological and replica interfaces and considering previous studies, we can now state that Palissy was very likely adding clay (Al) in his frit. Moreover, he was probably working with a firing time of more than 1 h followed by slow cooling in the oven. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Graphical abstract

13 pages, 2231 KiB

Open AccessArticle

Development of a Simple Method for Labeling and Identification of Protein Binders in Art

by Su Yin Ooi, Cátia Salvador, Sergio Martins, António Pereira, Ana Teresa Caldeira and João P Prates Ramalho

Heritage 2019, 2(3), 2444-2456; https://doi.org/10.3390/heritage2030150 - 16 Aug 2019

Cited by 3 | Viewed by 2717

Abstract

Easel paintings are assets with an important historic and cultural value. They usually possess a multi-tiered structure, composed of different layers some of which may present protein binders, making it important to identify these materials for restoration and conservation purposes. We propose the [...] Read more.

Easel paintings are assets with an important historic and cultural value. They usually possess a multi-tiered structure, composed of different layers some of which may present protein binders, making it important to identify these materials for restoration and conservation purposes. We propose the identification of different protein binders by a new fluorescent labeling method employing a coumarin based chromophore, C392STP (sodium(E/Z)-4-(4-(2-(6,7-dimethoxycoumarin-3-yl)vinyl)benzoyl)-2,3,5,6-tetrafluorobenzenesulfo-nate). The method was optimized using commercial proteins and was further tested on proteins extracted from hen’s egg yolk, white bovine milk, and rabbit skin glue. To model more realistic conditions, paint models of easel paintings were prepared. The paint models were made with hen’s egg yolk, white bovine milk, and rabbit skin glue, mixed with different pigments and submitted to artificial aging. Then the extracted proteins from the paint models were labeled with C392 which allowed a sensitive and selective identification by polyacrylamide gel electrophoresis (PAGE) of the different protein binders used. As a final test, three 19th century easel paintings, from the Italian painter Giorgio Marini, were analyzed. The results show the potential of the proposed method for the identification of protein binders present in easel paintings. Full article

(This article belongs to the Special Issue Cultural Heritage—Science, Materials and Technologies)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Cultural Heritage—Science, Materials and Technologies

Share This Special Issue

Special Issue Editor

Special Issue Information

Published Papers (13 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI