Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
3.9
2.5
Journals
Minerals
Sections
Clays and Other Industrial Mineral Materials
share announcement

Clays and Other Industrial Mineral Materials

A topical collection in Minerals (ISSN 2075-163X). This collection belongs to the section "Clays and Engineered Mineral Materials".

Viewed by 23412

Editors

Prof. Dr. Manuel Pozo Rodríguez

E-Mail Website1 Website2
Collection Editor
Department of Geology and Geochemistry, Universidad Autónoma of Madrid, 28049 Madrid, Spain
Interests: geology and geochemistry of clays; special clays applications; sepiolite–palygorskite; bentonite; Talc–kerolite; clays and health; mineral characterization
Special Issues, Collections and Topics in MDPI journals
Prof. Dr. Francisco Franco

E-Mail Website
Collection Editor
Department of Inorganic Chemistry, Universidad de Malaga, 29071 Malaga, Spain
Interests: kaolin; smectite group of minerals; sepiolite; palygorskite; pelotherapy; advanced, clay-based materials; pharmaceutical uses of adsorption processes; new technologies
Special Issues, Collections and Topics in MDPI journals
Prof. Dr. Michael G. Stamatakis

E-Mail Website
Collection Editor
Department of Geology & Geoenvironment, National and Kapodistrian University of Athens (NKUA), 157 84 Athens, Greece
Interests: raw materials characterization; industrial minerals in environmental applications; economic geology; green geochemistry; mineralogy; cementitious and construction materials; industrial clays; fillers–filters–absorbents; microporous raw materials; marine aggregates; raw materials policy; mine waste reuse; environmental impacts; ecosystems; geoarchaeology; natural heritage
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

Industrial minerals form an exceptionally varied group of raw materials that cover virtually all needs of modern human life, although their presence is often invisible. Industrial minerals can be defined as those minerals that, due to their physical and/or chemical properties, are used in industrial processes. From a compositional point of view, industrial mineral materials include both silicates (e.g., zeolites and clays) and nonsilicates (e.g., chromite and barite). No doubt, it can be said that clay minerals and clays, whether in their natural state or modified, are outstanding materials in the field of industrial mineral materials. They are abundant, relatively cheap to obtain, and mostly friendly from an industrial and health viewpoint.

Clay is a textural term referring to natural rock, sediment, and/or alteration products mainly made up of very fine-grained clay mineral phyllosilicates. Clay minerals, whether natural or synthetic, show economically interesting physical and chemical properties directly related to their structure and composition. Both the layer charge and small particle size of the clay minerals give place to suitable properties such as plasticity, sorption, rheology, and ion exchange, among others.

Taking into account their origin, clay minerals can be detrital and authigenic. Detrital clay minerals are inherited and thus reflect the sediment source (provenance). Authigenic clay minerals are, in a broad sense, “formed or generated in place”, whether related to soil processes, sedimentary deposition or diagenesis; in addition, authigenic clays are also formed under low-grade metamorphic conditions and/or the influence of hydrothermal events.

When they are classified as industrial minerals, a distinction is made between common clays, which usually consist of an association of several clay minerals, and special clays, which are typically formed of just one clay mineral and include kaolin, bentonite, sepiolite and palygorskite.

This collection aims to cover several broad objectives. It will be focused mainly on the study of industrial clays and clay minerals, but it also will deal with other industrial minerals. Approaches to these industrial mineral materials can be focused on: 1) geology, 2) mineralogy and geochemistry, 3) mineral genesis, 4) physical and physicochemical properties, 5) industrial and environmental applications, and 6) methods for their characterization.

We look forward to your submissions.

Prof. Dr. Manuel Pozo Rodríguez
Prof. Dr. Francisco Franco
Prof. Dr. Michael G. Stamatakis
Collection Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Clays
  • Clay minerals
  • Industrial mineral materials
  • Geology
  • Mineralogy
  • Geochemistry
  • Genesis
  • Properties
  • Applications
  • Common clays
  • Special clays
  • Bentonite
  • Kaolin and related clays
  • Sepiolite
  • Palygorskite

Published Papers (10 papers)

Download All Papers

2024

Jump to: 2022, 2021, 2020

13 pages, 2255 KiB  
Article
Impact of Limestone Surface Impurities on Quicklime Product Quality
by Matias Eriksson, Karin Sandström, Markus Carlborg and Markus Broström
Minerals 2024, 14(3), 244; https://doi.org/10.3390/min14030244 - 27 Feb 2024
Viewed by 861
Abstract
Quicklime is produced through the thermal processing of limestone in industrial kilns. During quarry operations, fine particulate quarry dust adheres to limestone lump surfaces, increasing the bulk concentration of impurities in limestone products. During thermal processing in a kiln, impurities such as Si, [...] Read more.
Quicklime is produced through the thermal processing of limestone in industrial kilns. During quarry operations, fine particulate quarry dust adheres to limestone lump surfaces, increasing the bulk concentration of impurities in limestone products. During thermal processing in a kiln, impurities such as Si, Mg, Al, Fe, and Mn react with Ca, reducing quicklime product quality. Which reactant phases are formed, and the extent to which these result in a reduction in quality, has not been extensively investigated. The present study investigated as-received and manually washed limestone product samples from two operational quarries using elemental compositions and a developed predictive multi-component chemical equilibrium model to obtain global phase diagrams for 1000–1500 °C, corresponding to the high-temperature zone of a lime kiln, identifying phases expected to be formed in quicklime during thermal processing. The results suggest that impurities found on the surface of the lime kiln limestone feed reduce the main quality parameter of the quicklime products, i.e., calcium oxide, CaO (s), content by 0.8–1.5 wt.% for the investigated materials. The results also show that, in addition to the effect of impurities, the quantity of CaO (s) varies greatly with temperature. More impurities result in more variation and a greater need for accurate temperature control of the kiln, where keeping the temperature below approximately 1300 °C, that of Hatrurite formation, is necessary for a product with higher CaO (s). Full article
►▼ Show Figures

Figure 1

0 pages, 6369 KiB  
Article
Assessment of Sorption of Anthocyanins from Red Cabbage onto Bentonites from Patagonia (Argentina)
by Vanina Rodríguez-Ameijide, Andrea Maggio, Manuel Pozo, M. Belén Gómez, Pablo M. Naranjo and M. Eugenia Roca-Jalil
Minerals 2024, 14(2), 133; https://doi.org/10.3390/min14020133 - 25 Jan 2024
Viewed by 621
Abstract
In the northern Patagonian region of Argentina, some of the largest bentonite deposits exist. Four bentonite samples (B1, B2, B3, and B4) from two deposits were thoroughly characterised and evaluated as potential adsorbents of anthocyanins extracted from red cabbage. Anthocyanins (ACys) are natural [...] Read more.
In the northern Patagonian region of Argentina, some of the largest bentonite deposits exist. Four bentonite samples (B1, B2, B3, and B4) from two deposits were thoroughly characterised and evaluated as potential adsorbents of anthocyanins extracted from red cabbage. Anthocyanins (ACys) are natural colourants obtained from fruits and plants and have shown excellent antioxidant properties that have promising applications in health. The adsorption of ACys onto bentonites enhances their stability relative to that observed in aqueous solutions. Material characterisation showed that three of the samples are soFdium bentonites (Na-bentonites: B2, B3, and B4), while the fourth exhibits a large quantity of magnesium and calcium in its interlayer, classifying it as a Mg-Ca-Na-bentonite (B1). Na-bentonites demonstrated higher ACy adsorption capacities, occurring through cation exchange, while Mg-Ca-Na-bentonite adsorption occurs by another type of interaction and a cooperative adsorption mechanism, resulting in the lowest ACy adsorption. The highest adsorption capacity was noted for B3, characterised by the highest smectite content, cation exchange capacity, and proportion of monovalent cations in its interlayer. Under the conditions studied, sodium smectites proved to be capable of retaining red cabbage ACys, thereby introducing a novel avenue for potential applications of regional materials with potential implications for health-related uses. Full article
►▼ Show Figures

Graphical abstract

19 pages, 5634 KiB  
Article
Effect of Iron Chloride (II) on Bentonites under Hydrothermal Gradients: A Comparative Study between Sodium Bentonite and Calcium Bentonite
by Carlos Mota-Heredia, Jaime Cuevas and Raúl Fernández
Minerals 2024, 14(2), 132; https://doi.org/10.3390/min14020132 - 25 Jan 2024
Viewed by 884
Abstract
This study investigates the performance of two bentonite materials, specifically MX-80 (Na-bentonite) and FEBEX (Ca-Mg-Na-bentonite), employed as engineered barriers in deep geological disposal facilities for the isolation of high-level radioactive waste, contained in metallic canisters. Experiments conducted at the laboratory scale focused on [...] Read more.
This study investigates the performance of two bentonite materials, specifically MX-80 (Na-bentonite) and FEBEX (Ca-Mg-Na-bentonite), employed as engineered barriers in deep geological disposal facilities for the isolation of high-level radioactive waste, contained in metallic canisters. Experiments conducted at the laboratory scale focused on the interaction of these bentonites with FeCl2 powder, used as a soluble iron source, to observe enhanced alteration of the bentonite. The experiments were carried out under a hydrothermal gradient. A dominant Na-Cl-SO4 saline solution was put in contact with the compacted bentonites from the top, while a constant temperature of 100 °C was maintained at the bottom using a heater in contact with the layer of FeCl2. The experimental cells were examined after six months of interaction. Various changes in the physical and chemical properties of the bentonites were observed. An increase in the water content, a reduction in the specific surface area and cation exchange capacity, changes in the distribution of aqueous species, and the formation of secondary minerals were observed. Reaction products formed at the bentonite interface with FeCl2, primarily comprising akaganeite, goethite, and hematite. The smectites showed evident structural modifications, with an enrichment in iron content, and a shift in the exchangeable ion distribution in the case of MX-80 bentonite. This work provides valuable insights into the complex interactions between bentonite barriers and materials that dissolve iron, serving as proxies for deep geological disposal environments and indicating the potential long-term behavior, taking into account higher concentrations of dissolved iron than those expected in a real repository. Full article
►▼ Show Figures

Figure 1

2022

Jump to: 2024, 2021, 2020

20 pages, 5150 KiB  
Article
Development and Characterization of Na2CO3-Activated Mozambican Bentonite: Prediction of Optimal Activation Conditions Using Statistical Design Modeling
by Afonso D. Macheca, António B. Mapossa, António J. Cumbane, Asmina E. Sulemane and Shepherd M. Tichapondwa
Minerals 2022, 12(9), 1116; https://doi.org/10.3390/min12091116 - 01 Sep 2022
Cited by 3 | Viewed by 1754
Abstract
A calcium bentonite clay from Boane region (Mozambique) was subjected to an Na2CO3 activation process. The methylene blue test together with energy-dispersive X-ray spectroscopy (EDX) analysis indicated the successful ion exchange of Ca2+ by Na+ ions since the [...] Read more.
A calcium bentonite clay from Boane region (Mozambique) was subjected to an Na2CO3 activation process. The methylene blue test together with energy-dispersive X-ray spectroscopy (EDX) analysis indicated the successful ion exchange of Ca2+ by Na+ ions since the cation exchange capacity (CEC) increased from 67.5 to 74 meq/100 g and the Na/Ca ratio from 2.91 up to 15.8, as the concentration of Na2CO3, activation temperature, and activation time were varied from 2 to 6 wt.%, from 25 to 65 °C, and from 2 to 4 h, respectively. However, the increase in the CEC did not follow the same trend as the increase in the Na/Ca ratio, and for the case of Na2CO3 concentration, the increase in the CEC was limited. The X-ray diffraction (XRD) patterns also confirmed that Ca-rich bentonite was effectively modified into Na-bentonite since after the activation, the d(001) decreased from 1.52 nm to 1.30 nm. The statistical design of the experiments showed that as well as the time and the temperature × time linear interactive effect, all the other independent factors and their interactive effects had a significant influence on the CEC. The response surface methodology (RSM) indicated that higher values of the CEC can be obtained under the optimal activation conditions of 4 wt.% Na2CO3, at a temperature of 45 °C, and with an activation time of 3 h. A statistical model was used to predict the CEC, and the R2 value was 0.99529, which denotes a satisfactory result in predicting the CEC. Full article
►▼ Show Figures

Figure 1

14 pages, 2728 KiB  
Article
Desorption of REEs from Halloysite and Illite: A Link to the Exploitation of Ion-Adsorption RE Ore Based on Clay Species
by Sen Qiu, Huashan Yan, Bengen Hong, Qibang Long, Jie Xiao, Fujian Li, Lichao Tong, Xiaowen Zhou and Tingsheng Qiu
Minerals 2022, 12(8), 1003; https://doi.org/10.3390/min12081003 - 08 Aug 2022
Cited by 5 | Viewed by 1922
Abstract
The adsorption/desorption characteristics for light and heavy rare earth elements (REEs) on halloysite and illite (which are beneficial for the utilization of ion-adsorption RE ore) were systematically investigated and compared. Additionally, halloysite and illite were fully charactered by XRD, SEM, microscope, zeta potential, [...] Read more.
The adsorption/desorption characteristics for light and heavy rare earth elements (REEs) on halloysite and illite (which are beneficial for the utilization of ion-adsorption RE ore) were systematically investigated and compared. Additionally, halloysite and illite were fully charactered by XRD, SEM, microscope, zeta potential, nitrogen adsorption–desorption isotherms and buffer pH to build the relationship between adsorption/desorption mechanisms and the minerals’ properties. The results of experiments show that the adsorption rate of halloysite is higher than illite, although they are both very fast and follow the pseudo-second-order kinetic model. The adsorption capacity of halloysite and illite increases with an increase in adsorption pH and remains constant when pH is higher than 4. Due to the narrow interlamellar spacing of halloysite and the fact that it is a nanotube, RE ions are adsorbed only through electrostatic attraction, whereas the adsorption and desorption pH have a significant effect on the recovery of RE ions from illite, because of the diverse adsorption mechanism. The results illustrated that the structure and surface properties of clays are also the key factors that affect RE ions leaching. Full article
►▼ Show Figures

Figure 1

20 pages, 11286 KiB  
Article
Sepiolite and Other Authigenic Mg-Clay Minerals Formation in Different Palustrine Environments (Madrid Basin, Spain)
by Juan Emilio Herranz and Manuel Pozo
Minerals 2022, 12(8), 987; https://doi.org/10.3390/min12080987 - 03 Aug 2022
Cited by 2 | Viewed by 2047
Abstract
Lithofacies belonging to mud-flat and palustrine deposits (lake margin) in the Miocene of the Madrid Basin (Spain) have been studied. Four lithofacies corresponding to mud flat (1 and 3) and palustrine (2 and 4) deposits have been differentiated. Units 1 and 3 consist [...] Read more.
Lithofacies belonging to mud-flat and palustrine deposits (lake margin) in the Miocene of the Madrid Basin (Spain) have been studied. Four lithofacies corresponding to mud flat (1 and 3) and palustrine (2 and 4) deposits have been differentiated. Units 1 and 3 consist mainly of mudstones and carbonates (calcretes and diolocretes). The clay fraction is dominated by trioctahedral smectite (up to 79%) with illite and kaolinite as minor components. The d(060) spacing value shows reflections at 1.52 and 1.50 Å indicating also the presence of dioctahedral phyllosilicates. Unit 2 consists predominantly of lutites (claystones), locally with carbonate and chert nodules. The clay fraction is dominated by sepiolite (up to 96%) with variable contents of smectite and subordinate illite. The d(060) spacing value shows reflections at 1.51 and 1.52 Å indicating trioctahedral clay minerals. Unit 4 consists mostly of carbonates (limestones) with mudstone and lutite inserts. The clay fraction shows different contents of sepiolite, palygorskite and dioctahedral smectite. The analysis of a selection of trace elements (Cr, Co, Th, La, Sc) has allowed us to determine the characteristics of the source area as dioritic, somewhat different from those of the nearby materials from the Batallones sector. Sepiolite shows FWHM values ranging between 0.68 and 1.10 (2θ), indicating “low crystallinity sepiolite”. Differences in the conditions of formation of magnesian smectite and palygorskite have been observed in the mud-flat and palustrine deposits. The formation of sepiolite mainly by neoformation in palustrine deposits with different hydrochemistry is remarkable, leading to differences in fibre size and crystallinity of the fibrous clay mineral. Authigenic transformation processes from previous Al-rich phases would be responsible for the formation of saponite and palygorskite in mud flat and palustrine environments, with different pH conditions. Full article
►▼ Show Figures

Figure 1

28 pages, 43332 KiB  
Article
Coal Sludge Permeability Assessment Based on Rowe Cell Consolidation, and Filtration Investigations
by Justyna Adamczyk and Radosław Pomykała
Minerals 2022, 12(2), 212; https://doi.org/10.3390/min12020212 - 07 Feb 2022
Cited by 2 | Viewed by 1783
Abstract
In this paper, an attempt has been made to investigate the possibility of using coal sludge to seal a landfill site by presenting the results of their compressibility and permeability tests. Coal sludge is a fine-grained waste from the coal enrichment process, and [...] Read more.
In this paper, an attempt has been made to investigate the possibility of using coal sludge to seal a landfill site by presenting the results of their compressibility and permeability tests. Coal sludge is a fine-grained waste from the coal enrichment process, and its permeability is also highly dependent on its degree of consolidation. The tests were carried out in a Rowe Cell, making it possible to determine the water permeability coefficient more precisely by determining the degree of the material consolidation during testing. The test was carried out using backpressure conditions. The test procedure in the Rowe Cell consisted of the following three steps: saturation, consolidation, and filtration. The coal sludge was taken directly from the filter presses as a by-product of the fines’ coal enrichment process. The paper presents the results of the individual stages performed in a Rowe Cell. The consolidation coefficient was determined using three different methods (Casagrande, Taylor, and Robbinson methods). The permeability coefficient was measured by the indirect and the direct method, the results of both were compared. The results (k < 10−9 m/s) indicated that the value of the permeability coefficient responds to the value for isolating barrier materials. Full article
►▼ Show Figures

Figure 1

2021

Jump to: 2024, 2022, 2020

13 pages, 4024 KiB  
Article
A Novel Calcium Oxalate/Sepiolite Composite for Highly Selective Adsorption of Pb(II) from Aqueous Solutions
by Hui Xie, Shilin Zhang, Jingyan Liu, Jinqing Hu and Aidong Tang
Minerals 2021, 11(6), 552; https://doi.org/10.3390/min11060552 - 23 May 2021
Cited by 5 | Viewed by 2379
Abstract
Synthesizing functional nanomaterials from naturally abundant clay has always been of vital importance for resource utilization, however, the lack of new methods to effectively utilize low-grade clay presents a significant challenge. Herein, a calcium oxalate/sepiolite nanocomposite (SMN-x) was prepared by using the water [...] Read more.
Synthesizing functional nanomaterials from naturally abundant clay has always been of vital importance for resource utilization, however, the lack of new methods to effectively utilize low-grade clay presents a significant challenge. Herein, a calcium oxalate/sepiolite nanocomposite (SMN-x) was prepared by using the water bath heating method to convert the associated calcium carbonate in low-grade sepiolite into calcium oxalate. The developed composite was subsequently used to remove Pb(II) from the aqueous solutions. The SMN-3 adsorbent prepared by heating in a water bath at 90 °C for 3 h (with a high specific surface area of 234.14 m2·g−1) revealed the maximum Pb(II) adsorption capacity of 504.07 mg·g−1 at pH 5, which was about five times higher than that of sepiolite (105.57 mg·g−1). Further, the SMN-3 adsorbent possessed a much higher selectivity for Pb(II) as compared to the other metal ions. Moreover, the residue was noted to be stable and safe. The adsorption kinetics and isotherms conformed to the quasi-second-order kinetic and Langmuir models. During the adsorption process, ion exchange was noted to the main mechanism, however, it was also accompanied by electrostatic attraction. This study provides a novel strategy for the sustainable development of simple and efficient adsorbents by utilizing low-grade clay minerals. Full article
►▼ Show Figures

Figure 1

2020

Jump to: 2024, 2022, 2021

17 pages, 3970 KiB  
Article
Sustainable Reuse of Coal Mine Waste: Experimental and Economic Assessments for Embankments and Pavement Layer Applications in Morocco
by Mustapha Amrani, Yassine Taha, Yassine El Haloui, Mostafa Benzaazoua and Rachid Hakkou
Minerals 2020, 10(10), 851; https://doi.org/10.3390/min10100851 - 26 Sep 2020
Cited by 25 | Viewed by 4581
Abstract
This paper deals with the potential reuse of coal mine waste rocks (CMWR) as an alternative material for road construction to conserve the natural resources and sustainable management of mining waste. The investigation was conducted through the determination of the chemical, mineralogical, geotechnical [...] Read more.
This paper deals with the potential reuse of coal mine waste rocks (CMWR) as an alternative material for road construction to conserve the natural resources and sustainable management of mining waste. The investigation was conducted through the determination of the chemical, mineralogical, geotechnical properties, and acid mine drainage formulation of CMWR as well as economic feasibility. This waste was used either alone for embankments and mixed with stabilizing agents fly ash (FA) and hydraulic road binder (HRB) for pavement applications. The experimental results confirmed that weathered CMWR can be successfully used alone as a sustainable alternative material for the embankment. Furthermore, the use of stabilizing agents in the following ratio CMWR:FA:HRB = 80:20:5 allow the use of CMWR in road sub-base layers for high-traffic pavements. Also, the environmental investigations showed that CMWR does not present any potential contaminating risk on the surrounding environment and most of the pyrite particles were already oxidized. Therefore, the environmental impact of acid mine drainage produced by pyritic waste throughout its life cycle can be neglected. Finally, an economic case study confirmed the workability of CMWR reuse in a radius of 29 km around their dumps by resulting in a lower cost compared with conventional materials. Full article
►▼ Show Figures

Figure 1

13 pages, 2865 KiB  
Article
Application of Evolved Gas Analysis Technique for Speciation of Minor Minerals in Clays
by Eulalia Zumaquero Silvero, Jessica Gilabert Albiol, Eva María Díaz-Canales, María Jesús Ventura Vaquer and María Pilar Gómez-Tena
Minerals 2020, 10(9), 824; https://doi.org/10.3390/min10090824 - 18 Sep 2020
Cited by 7 | Viewed by 3938
Abstract
Mineralogical characterization of clays used in manufacturing of traditional ceramic products is critical for guarantee the quality of the final product, but also for assessing the environmental impact of the industrial process in terms of atmospheric emissions. In fact, the presence of impurities [...] Read more.
Mineralogical characterization of clays used in manufacturing of traditional ceramic products is critical for guarantee the quality of the final product, but also for assessing the environmental impact of the industrial process in terms of atmospheric emissions. In fact, the presence of impurities even in low-level concentrations can have a big impact. So, it is very important to carry out an accurate mineral quantification of those minerals which are related to carbon dioxide and acid emissions (hydrogen fluoride, hydrogen chloride or sulfur dioxide). The development of hyphenated techniques coupling thermal analysis equipment with mass spectrometry and Fourier-transform infrared spectroscopy provides more valuable information and lower limit quantification than other primary techniques, such as X-ray diffraction or infrared spectroscopy. The main objective of this work is to develop an analytical procedure using evolved gas analysis to identify and quantify minerals such as chlorides, sulfides, carbonaceous materials and minor clay minerals. In addition to this, the study includes the analysis of acid emissions during the ceramic firing treatment even if they are present at low quantitative levels. This methodology was applied to reference materials so that it allows the identification of sulfur, chlorine, fluorine and carbonaceous compounds in concentrations lower than 1%. Full article
►▼ Show Figures

Figure 1

Back to TopTop