Jessica Occhiuzzi, Grazia Giuseppina Politano, Gianluca D’Olimpio, Antonio Politano,
The recent advent of two-dimensional (2D) materials has had a ground-breaking impact on science and technology. To exploit in technology their unique thickness-dependent physicochemical properties, the large-scale production of 2D materials is mandatory, but it represents an open challenge still due to various pitfalls and severe limitations including the toxicity of state-of-the-art solvents. Thus, liquid-phase exfoliation based on green and bioderived solvents represents an ideal methodology for ...
Tópico(s): MXene and MAX Phase Materials
2023 - Multidisciplinary Digital Publishing Institute | Molecules
Dario Mastrippolito, L. Ottaviano, Jing Wang, Jinjin Yang, Faming Gao, Mushtaq Ali, Gianluca D’Olimpio, Antonio Politano, Stefano Palleschi, Shafaq Kazim, R. Gunnella, Andrea Di Cicco, A. Sgarlata, Judyta Strychalska‐Nowak, Tomasz Klimczuk, R. J. Cava, L. Lozzi, G. Profeta,
Emerging defect- and oxidation-induced extrinsic phases are discovered in low-dimensional CrCl 3 .
Tópico(s): Electronic and Structural Properties of Oxides
2021 - Royal Society of Chemistry | Nanoscale Advances
Produção Nacional
Revisado por pares
Camila Silva Bôaventura, Daniel Padilha Rodrigues, Olimpio Antonio Cornehl Silva, Fabrício Henrique Beltrani, Rayssa Araruna Bezerra de Melo, Almir Galvão Vieira Bitencourt, Gustavo Gomes Mendes, Rubens Chojniak,
To evaluate the indications for performing magnetic resonance imaging of the female pelvis at a referral center for cancer.This was a retrospective, single-center study, conducted by reviewing medical records and imaging reports. We included 1060 female patients who underwent magnetic resonance imaging of the pelvis at a cancer center between January 2013 and June 2014. The indications for performing the examination were classified according to the American College of Radiology (ACR) criteria.The ...
Tópico(s): Ovarian cancer diagnosis and treatment
2017 - Colégio Brasileiro de Radiologia e Diagnóstico por Imagem | Radiologia Brasileira
Dario Mastrippolito, Stefano Palleschi, Gianluca D’Olimpio, Antonio Politano, M. Nardone, P. Benassi, L. Ottaviano,
Via experiments performed by varying the doping level of single-layer mechanically exfoliated MoS2via post exfoliation thermal annealing in the 200-300 °C temperature range, we study the power dependent room temperature (RT) photoluminescence (PL), which is dominated by A type excitons. The PL spectral yields of the as-exfoliated and annealed samples show sub-linear behaviour as a function of the excitation laser power. The PL signal of the 200 °C annealed sample is dominated by the charged exciton ( ...
Tópico(s): MXene and MAX Phase Materials
2020 - Royal Society of Chemistry | Nanoscale
Sandra E. Robles-Cruz, Manuel Watangua, Leonardo Isidoro, Joan Carles Melgarejo i Draper, Salvador Galí, Antonio Olimpio,
The Catoca group-I kimberlite, the only currently active diamond-producing mine in Angola, was emplaced in the northeastern part of the Lucapa structure. We focus here on compositional and textural variations in ilmenite from drill-core material, in the hope of elucidating events before and during the emplacement of the kimberlitic magma. We have characterized four main variants of ilmenite, with enrichments in Fe3+, Mg, Mn and nearly stoichiometric ilmenite, and in seven textural classes, and have ...
Tópico(s): earthquake and tectonic studies
2009 - Elsevier BV | Lithos
Aurora C.J.M. Bambi, Alessandra Costanzo, António Olímpio Gonçalves, Joan Carles Melgarejo i Draper,
Abstract Three Angolan carbonatites were selected to evaluate the change in composition of pyrochlores during magmatic evolution: the Tchivira carbonatites occur in a plutonic complex, the Bonga carbonatites represent hypabyssal carbonatites and the Catanda carbonatites are volcanic in origin. In Tchivira pyrochlore, zoning is poorly developed; fluorine is dominant at the Y site; chemical zoning may arise as a result of substitutions for Nb in the B site; and the rare earth element ( REE ), U, Th and ...
Tópico(s): earthquake and tectonic studies
2012 - Cambridge University Press | Mineralogical Magazine
Joan Carles Melgarejo i Draper, Alessandra Costanzo, Aurora C.J.M. Bambi, António Olímpio Gonçalves, Andrés B. Neto,
The Tchivira carbonatites contain several pyrochlore generations. Rare pyrochlore crystals, close to the fluorcalciopyrochlore end member composition, occur as primary magmatic crystals and are replaced due to subsolidus hydrothermal processes. These produced leaching of Na in the A position, balanced by F removal from the Y position. Interaction of oxydizing hydrothermal fluids with carbonatites and host rocks produced a sequence of hydrothermal alterations with zonal distribution. From the host ...
Tópico(s): earthquake and tectonic studies
2012 - Elsevier BV | Lithos
Lisard Torró, C. Villanova, M.K. Castillo, Marc Campeny, António Olímpio Gonçalves, Joan Carles Melgarejo i Draper,
Abstract The Virulundo carbonatite in Angola is one of the largest in the world and contains pyrochlore as an accessory mineral in all of the carbonatite units (calciocarbonatites, ferrocarbonatites, carbonatite breccias and trachytoids). The primary magmatic pyrochlore is fluorine dominant and typically contains about equal molar quantities of Ca and Na at the A site. High-temperature hydrothermal processes have resulted in the pseudomorphic replacement of the primary pyrochlore by a second generation ...
Tópico(s): High-pressure geophysics and materials
2012 - Cambridge University Press | Mineralogical Magazine
Sandra E. Robles-Cruz, M. Escayola, Simon E. Jackson, Salvador Galí, Vladimir Pervov, Manuel Watangua, António Olímpio Gonçalves, Joan Carles Melgarejo i Draper,
We present the first age determinations of zircon from the diamondiferous Catoca kimberlite in northeastern Angola, the fourth largest kimberlite body in the world. The U–Pb ages were obtained using a Sensitive High Resolution Ion Microprobe II (SHRIMP II) on zircon crystals derived from tuffisitic kimberlite rocks and heavy-mineral concentrates from the Catoca kimberlite. The SHRIMP results define a single weighted mean age of 117.9 ± 0.7 Ma (Mean square weighted deviation MSWD = 1.3). More than 90% ...
Tópico(s): earthquake and tectonic studies
2012 - Elsevier BV | Chemical Geology
C. Strganac, Johanna Salminen, Louis L. Jacobs, Michael J. Polcyn, Kurt M. Ferguson, Octávio Mateus, Anne S. Schulp, Maria Luísa Morais, Tatiana da Silva Tavares, António Olímpio Gonçalves,
We present the δ13C and paleomagnetic stratigraphy for marine strata at the coast of southern Angola, anchored by an intercalated basalt with a whole rock 40Ar/39Ar radiometric age of 84.6 ± 1.5 Ma, being consistent with both invertebrate and vertebrate biostratigraphy. This is the first African stable carbon isotope record correlated to significant events in the global carbon record spanning the Late Cenomanian to Early Maastrichtian. A positive ∼3‰ excursion seen in bivalve shells below the basalt ...
Tópico(s): Geology and Paleoclimatology Research
2014 - Elsevier BV | Journal of African Earth Sciences
C. Strganac, Louis L. Jacobs, Michael J. Polcyn, Octávio Mateus, Timothy S. Myers, Johanna Salminen, S.R. May, Ricardo Araújo, Kurt M. Ferguson, António Olímpio Gonçalves, Maria Luísa Morais, Anne S. Schulp, Tatiana da Silva Tavares,
Abstract The Bench 19 Bonebed at Bentiaba, Angola, is a unique concentration of marine vertebrates preserving six species of mosasaurs in sediments best correlated by magnetostratigraphy to chron C32n.1n between 71.4 and 71.64 Ma. The bonebed formed at a paleolatitude near 24°S, with an Atlantic width at that latitude approximating 2700 km, roughly half that of the current width. The locality lies on an uncharacteristically narrow continental shelf near transform faults that controlled the coastal ...
Tópico(s): Evolution and Paleontology Studies
2014 - Cambridge University Press | Netherlands Journal of Geosciences – Geologie en Mijnbouw
Ricardo Araújo, Michael J. Polcyn, Anne S. Schulp, Octávio Mateus, Louis L. Jacobs, António Olímpio Gonçalves, M.-L. Morais,
Abstract We report here a new elasmosaurid from the early Maastrichtian at Bentiaba, southern Angola. Phylogenetic analysis places the new taxon as the sister taxon to Styxosaurus snowii , and that clade as the sister of a clade composed of ( Hydrotherosaurus alexandrae ( Libonectes morgani + Elasmosaurus platyurus )). The new taxon has a reduced dorsal blade of the scapula, a feature unique amongst elasmosaurids, but convergent with cryptoclidid plesiosaurs, and indicates a longitudinal protraction-retraction ...
Tópico(s): Amphibian and Reptile Biology
2015 - Cambridge University Press | Netherlands Journal of Geosciences – Geologie en Mijnbouw
Ricardo Araújo, Michael J. Polcyn, Johan Lindgren, Louis L. Jacobs, Anne S. Schulp, Octávio Mateus, António Olímpio Gonçalves, M.-L. Morais,
Abstract New elasmosaurid plesiosaur specimens are described from the Early Maastrichtian of Angola. Phylogenetic analyses reconstruct the Angolan taxon as an aristonectine elasmosaurid and the sister taxon of an unnamed form of similar age from New Zealand. Comparisons also indicate a close relationship with an unnamed form previously described from Patagonia. All of these specimens exhibit an ostensibly osteologically immature external morphology, but histological analysis of the Angolan material ...
Tópico(s): Amphibian and Reptile Biology
2015 - Cambridge University Press | Netherlands Journal of Geosciences – Geologie en Mijnbouw
Marc Campeny, Vadim S. Kamenetsky, Joan Carles Melgarejo i Draper, José Mangas, José Mánuel, María Pura Alfonso Abella, Maya Kamenetsky, Aurora C.J.M. Bambi, António Olímpio Gonçalves,
A set of small volcanic edifices with tuff ring and maar morphologies occur in the Catanda area, which is the only locality with extrusive carbonatites reported in Angola. Four outcrops of carbonatite lavas have been identified in this region and considering the mineralogical, textural and compositional features, we classify them as: silicocarbonatites (1), calciocarbonatites (2) and secondary calciocarbonatites produced by the alteration of primary natrocarbonatites (3). Even with their differences, ...
Tópico(s): Geochemistry and Geologic Mapping
2015 - Elsevier BV | Lithos
Octávio Mateus, Marco Marzola, Anne S. Schulp, Louis L. Jacobs, Michael J. Polcyn, Vladimir Pervov, António Olímpio Gonçalves, Maria Luísa Morais,
We report here new and the first mammaliamorph tracks from the Early Cretaceous of Africa. The tracksite, that also bears crocodylomorph and sauropod dinosaurian tracks, is in the Catoca diamond mine, Lunda Sul Province, Angola. The mammaliamorph tracks have a unique morphology, attributed to Catocapes angolanus ichnogen. et ichnosp. nov. and present an anterolateral projection of digit I and V. The tracks with an average length of 2.7 cm and width of 3.2 cm are the largest mammaliamorph tracks ...
Tópico(s): Ichthyology and Marine Biology
2017 - Elsevier BV | Palaeogeography Palaeoclimatology Palaeoecology
Montgarri Castillo-Oliver, Joan Carles Melgarejo i Draper, Salvador Galí, Vladimir Pervov, António Olímpio Gonçalves, William L. Griffin, Norman J. Pearson, Suzanne Y. O’Reilly,
Magnesian ilmenite is a common kimberlite indicator mineral, although its use in diamond exploration is still controversial. Complex crystallisation and replacement processes have been invoked to explain the wide compositional and textural ranges of ilmenite found in kimberlites. This work aims to shed light on these processes, as well as their implications for diamond exploration. Petrographic studies were combined for the first time with both major- and trace-element analyses to characterise the ...
Tópico(s): earthquake and tectonic studies
2017 - Elsevier BV | Lithos
Andrea Giuliani, Marc Campeny, Vadim S. Kamenetsky, Juan Carlos Afonso, Roland Maas, Joan Carles Melgarejo i Draper, Barry P. Kohn, Erin Matchan, José Mangas, António Olímpio Gonçalves, José Mánuel,
Research Article| August 17, 2017 Southwestern Africa on the burner: Pleistocene carbonatite volcanism linked to deep mantle upwelling in Angola Andrea Giuliani; Andrea Giuliani * 1School of Earth Sciences, The University of Melbourne, Parkville, VIC 3010, Australia2ARC Centre of Excellence for Core to Crust Fluid Systems and GEMOC, Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia3Department of Earth Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands * ...
Tópico(s): earthquake and tectonic studies
2017 - Geological Society of America | Geology
Produção Nacional
Suzi Huff Theodoro, Jean Pierre Tchouankoué, António Olímpio Gonçalves, O. H. Leonardos, Julia Harper,
Este trabalho apresenta os resultados de uma pesquisa em desenvolvimento por cientistas brasileiros e de três países africanos (Angola, África do Sul e Camarões). O fio condutor da pesquisa foi a tecnologia da rochagem, que prevê a adição de rochas moídas, que contenham uma ampla variedade de agrominerais, para melhorar os índices de fertilidade dos solos. A partir de interesses comuns - a expansão da pesquisa sobre remineralização dos solos agrícolas e a difusão da tecnologia, o grupo visa principalmente ...
Tópico(s): Soil Management and Crop Yield
2013 - UNIVERSIDADE FEDERAL DE PERNAMBUCO | Revista Brasileira de Geografia Física
Sandra Amores-Casals, Joan Carles Melgarejo i Draper, Cosimo Bambi, António Olímpio Gonçalves, Eduardo Alves Morais, José Mánuel, ARTUR BASTOS NETO, Alessandra Costanzo, Joan Martı́,
The Bonga complex is composed of a central carbonatite plug (with a ferrocarbonatite core) surrounded by carbonatite cone sheets and igneous breccias of carbonatitic, fenitic, phoscoritic and lamprophyric xenoliths set in a carbonatitic, lamprophyric or mingled mesostase. To reconstruct the dynamics of the complex, the pyrochlore composition and distribution have been used as a proxy of magmatic-hydrothermal evolution of the complex. An early Na-, F-rich pyrochlore is disseminated throughout the ...
Tópico(s): earthquake and tectonic studies
2019 - Multidisciplinary Digital Publishing Institute | Minerals
C. Strganac, Louis L. Jacobs, Michael J. Polcyn, Kurt M. Ferguson, Octávio Mateus, António Olímpio Gonçalves, M.-L. Morais, Tatiana da Silva Tavares,
Abstract Stable oxygen isotope values of inoceramid marine bivalve shells recovered from Bentiaba, Angola, are utilised as a proxy for paleotemperatures during the Late Cretaceous development of the African margin of the South Atlantic Ocean. The δ 18 O values derived from inoceramids show a long-term increase from –3.2‰ in the Late Turonian to values between –0.8 and –1.8‰ in the Late Campanian. Assuming a constant oceanic δ 18 O value, an ∼2‰ increase may reflect cooling of the shallow marine environment ...
Tópico(s): Isotope Analysis in Ecology
2015 - Cambridge University Press | Netherlands Journal of Geosciences – Geologie en Mijnbouw
António Olímpio Gonçalves, Joan Carles Melgarejo i Draper, María Pura Alfonso Abella, Sandra Amores, A. Paniagua, Andrés Buta Neto, Eduardo Alves Morais, Antoni Camprubí,
The Giraúl granitic pegmatite field in Angola is composed of five pegmatite types, the most evolved belong to the beryl-columbite, beryl-columbite-phosphate and spodumene types. Pegmatites are concentrically zoned with increased grain size toward a quartz core; the most evolved pegmatites have well-developed replacement units. These pegmatites are rich in Nb-Ta oxide minerals and the field has a moderate interest for critical elements such as Ta and Hf. Tourmaline, garnet and micas occur as accessory ...
Tópico(s): earthquake and tectonic studies
2019 - Multidisciplinary Digital Publishing Institute | Minerals
Timothy S. Myers, Michael J. Polcyn, Octávio Mateus, Diana P. Vineyard, António Olímpio Gonçalves, Louis L. Jacobs,
Abstract A new stem cheloniid turtle, Cabindachelys landanensis , gen. et sp. nov., is represented by a nearly complete skull and partial hyoid collected in lower Paleocene shallow marine deposits, equivalent to the offshore Landana Formation, near the town of Landana in Cabinda, Angola. A partial chelonioid carapace previously reported from this locality is referred here to C. landanensis . Cabindachelys landanensis possesses clear synapomorphies of Pan‐Cheloniidae, including a rod‐like rostrum basisphenoidale, ...
Tópico(s): Turtle Biology and Conservation
2017 - Wiley | Papers in Palaeontology
Produção Nacional
Revisado por pares
Bruno Venancio da Silva, Peter Christian Hackspacher, Marli Carina Siqueira Ribeiro, Ulrich A. Glasmacher, António Olímpio Gonçalves, Carolina Doranti-Tiritan, Daniel Françoso de Godoy, Renata Regina Constantino,
There are two main points of view regarding how continental margins evolve. The first one argues that the present-day margins have been developed by long-term denudation since a major exhumation episode, probably driven by rifting or another relevant tectonic event. The second one argues that continental margins underwent alternating burial and exhumation episodes related to crustal tectonic and surface uplift and subsidence. To demonstrate that the proximal domain of the southwestern Angolan margin ...
Tópico(s): Geological and Geophysical Studies
2018 - Springer Science+Business Media | International Journal of Earth Sciences
Sandra Amores-Casals, António Olímpio Gonçalves, Joan Carles Melgarejo i Draper, Joan Martı́,
The Angolan alkaline–carbonatite complex of Monte Verde has a semi-circular shape and is comprised of a central intrusion of foidolite rocks surrounded by concentrically arranged minor bodies of other alkaline rocks and carbonatite magmatic breccias. This rock association is hosted by fenitized Eburnean granites. Concentric swarms of alkaline dykes of late formation, mostly of nepheline trachyte composition, crosscut the previous units. Most high-field strength elements (HFSE) and rare earth elements ( ...
Tópico(s): Geochemistry and Elemental Analysis
2019 - Multidisciplinary Digital Publishing Institute | Minerals
Produção Nacional
Revisado por pares
André Lopes Carvalho, Luiz Paulo Kowalski, Ivan Marcelo Gonçalves Agra, Everton Pontes, Olímpio Daniel de Campos, Antônio Cássio Assis Pellizzon,
OBJECTIVE To analyze the long‐term results of patients with N3 neck metastasis from squamous carcinoma of the head and neck. STUDY DESIGN This study is based on the analysis of a retrospective cohort of 224 previously untreated patients with squamous cell carcinoma of the head and neck and lymph node metastasis sized greater than 6 cm (N3) who were evaluated from 1981 to 1996. RESULTS Fifty‐four patients (24.1%) underwent neck dissection, 137 underwent radiotherapy alone (61.2%), and 33 received only ...
Tópico(s): Cancer Diagnosis and Treatment
2005 - Wiley | Otolaryngology
S. Mustafa Kazim, Mushtaq Ali, Stefano Palleschi, Gianluca D’Olimpio, Dario Mastrippolito, Antonio Politano, R. Gunnella, Andrea Di Cicco, Marco Renzelli, G. Moccia, O A Cacioppo, R. Alfonsetti, Judyta Strychalska‐Nowak, Tomasz Klimczuk, R. J. Cava, L. Ottaviano,
After the recent finding that CrI3, displays ferromagnetic order down to its monolayer, extensive studies have followed to pursue new two-dimensional (2D) magnetic materials. In this article, we report on the growth of single crystal CrCl3 in the layered monoclinic phase. The system after mechanical exfoliation exhibits stability in ambient air (the degradation occurs on a time scale at least four orders of magnitude longer than is observed for CrI3). By means of mechanical cleavage and atomic force ...
Tópico(s): Multiferroics and related materials
2020 - IOP Publishing | Nanotechnology
Danil W. Boukhvalov, Valentina Paolucci, Gianluca D’Olimpio, C. Cantalini, Antonio Politano,
Chemical reactions on surfaces of innovative materials have direct implications in application fields, such as catalysis, batteries, gas sensing and desalination.
Tópico(s): Advanced biosensing and bioanalysis techniques
2020 - Royal Society of Chemistry | Physical Chemistry Chemical Physics
Valentina Paolucci, Gianluca D’Olimpio, L. Lozzi, Antonio M. Mio, L. Ottaviano, M. Nardone, Giuseppe Nicotra, Patrice Le-Cornec, C. Cantalini, Antonio Politano,
Liquid-phase exfoliation is the most suitable platform for large-scale production of two-dimensional materials. One of the main open challenges is related to the quest of green and bioderived solvents to replace state-of-the-art dispersion media, which suffer several toxicity issues. Here, we demonstrate the suitability of methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (Rhodiasolv Polarclean) for sonication-assisted liquid-phase exfoliation of layered materials for the case-study examples of WS2, ...
Tópico(s): Advanced Sensor and Energy Harvesting Materials
2020 - American Chemical Society | ACS Sustainable Chemistry & Engineering
Produção Nacional
Revisado por pares
Seixas Rezende Oliveira, Matheus S. Lima‐Ribeiro, Antonio Olímpio de Souza, Carolina Emília dos Santos, Kauê Vergilio Silva, Marlon Zortéa, Frederico Augusto Guimarães Guilherme, Fabiano Rodrigues de Melo, Steffan Eduardo Silva Carneiro, Wilian Vaz Silva, Alessandro Ribeiro de Morais,
The current biodiversity crisis has stimulated the creation of protected areas, a fundamental conservation tool for halting biodiversity loss. Moreover, protected areas are often accessed by researchers for field observations and natural experiments, thus representing also an important tool promoting biodiversity discoveries. Here, we investigated the importance of protected areas in achieving both conservation and scientific roles for anurans in the Brazilian Cerrado. We specifically compared species ...
Tópico(s): Amphibian and Reptile Biology
2019 - Elsevier BV | Journal for Nature Conservation
Esperança Tauler, Jingyao Xu, Marc Campeny, Sandra Amores, Joan Carles Melgarejo i Draper, Salvador Martı́nez, António Olímpio Gonçalves,
Abstract Large kaolin deposits developed by weathering on Precambrian granitic rocks have been discovered in the Caluquembe area, Huíla province, Angola. To determine accuracy of analysis and to evaluate the kaolinite grade, a full-profile Rietveld refinement by X-ray Powder Diffraction (XRPD) and Thermal Gravimetric Analysis (TGA) was used. Caluquembe kaolin is composed mainly of kaolinite (44–93 wt.%), quartz (0–23 wt.%), and feldspar (4–14 wt.%). The Aparicio-Galán-Ferrell index (AGFI), calculated ...
Tópico(s): Geochemistry and Geologic Mapping
2019 - Cambridge University Press | Clays and Clay Minerals