Results 71 to 80 of about 45,988 (266)

Glass from Teniky (Madagascar): Geochemical Evidence for Multiple Production Systems and Long‐Distance Exchange in the Mediaeval Indian Ocean

open access: yesArchaeometry, EarlyView.
ABSTRACT The inland rock‐cut site of Teniky, located in the Isalo massif of southern Madagascar, represents an exceptional archaeological context recently dated to the 11th–12th centuries ad, corresponding to the early phases of settlement on the island.
Jean Rodier   +2 more
wiley   +1 more source

Long story encrypted in a small grain – zircon from meta-andesite in the Lower Köli Nappes reveals a complex history of the Virisen Arc Terrane, Scandinavian Caledonides, Sweden

open access: yesMineralogia
This short report presents the investigation results on the zircon from meta-andesitic rock from the Ankarede Volcanite Formation of the Lower Köli Nappe Complex in Scandinavian Caledonides. Previous U-Pb dating revealed a wide span of dates ranging from
Walczak Katarzyna A.   +4 more
doaj   +1 more source

New U-Pb zircon data for Maarianvaara granite and Tohmajärvi volcanic complex, eastern Finland: geologic implications [PDF]

open access: yesBulletin of the Geological Society of Finland
New U-Pb zircon ages reported for samples from the Maarianvaara granite and Tohmajärvi volcanic complex (TVC) corroborate previous estimates of their magmatic emplacement at ca. 1.85 Ga and 2.11 Ga, respectively. The ca.
Asko Kontinen   +3 more
doaj   +1 more source

ReMoDe – Recursive modality detection in distributions of ordinal data

open access: yesBritish Journal of Mathematical and Statistical Psychology, EarlyView.
Abstract The detection of the number of modes in distributions of ordinal data is relevant for applied researchers across disciplines, from uncovering polarization to detecting incidence groups in clinical symptom scales. Yet, established modality detection methods are either purely descriptive or not developed for ordinal data.
Madlen Hoffstadt   +3 more
wiley   +1 more source

Influence of Laser Repetition Rate, Fluence and Spot Size on LA‐Q‐ICP‐MS/MS 87Sr/86Sr Precision: Insights from Apatites and Silicate Glasses

open access: yesGeostandards and Geoanalytical Research, EarlyView.
Key Points Higher laser repetition rate, fluence and larger spot size increase signal intensity. Higher laser repetition rate produces overlaps in aerosolised particles, improving signal stability and precision. For Sr‐rich materials, moderate spot diameter (≤ 60 μm), 3 J cm‐2 fluence and ≥ 12 Hz repetition rate are recommended.
Edafe O. Ominigbo   +4 more
wiley   +1 more source

Appraisal of Six Natural Mica Reference Materials for In Situ Rb‐Sr Geochronology

open access: yesGeostandards and Geoanalytical Research, EarlyView.
Key Points Evaluated six natural mica reference materials for in situ LA‐ICP‐MS/MS Rb‐Sr geochronology using geochemical, microstructural and isotopic characterisation. Identified robust primary reference materials: Mount Dromedary biotite (99.37 Ma) and Mica‐Fe biotite (307.75 Ma). La Posta biotite and Högsbo muscovite are suitable secondary reference
Hugo K.H. Olierook   +38 more
wiley   +1 more source

6‐Month Clinical Evaluation of Reduced Dentin Etching Time Using Universal Adhesives in Noncarious Cervical Lesions: A Double‐Blind Randomized Clinical Trial

open access: yesJournal of Esthetic and Restorative Dentistry, EarlyView.
ABSTRACT Objectives To evaluate the effect of reduced dentin etching time on the clinical performance of two universal adhesive systems in noncarious cervical lesions (NCCLs). Methods A total of 144 NCCLs restorations were randomly placed in 36 participants according to four experimental groups: SUP5 (Scotchbond Universal Plus adhesive [pH ≈2.5–2.7 ...
Mario Felipe Gutiérrez   +4 more
wiley   +1 more source

Metamorphic or Igneous Zircon? Classification Through Rare Earth Elements, Machine Learning and Logistic Regression

open access: yesJournal of Metamorphic Geology, EarlyView.
ABSTRACT Zircon is a common, highly refractory accessory mineral found in sedimentary, igneous and metamorphic rocks that forms through various processes (e.g., magmatic, hydrothermal, metamorphic growth and recrystallization). Trace element compositions of detrital zircon have been widely applied to understanding tectonic processes and continental ...
Jarrod M. Burges   +5 more
wiley   +1 more source

Paramagnetic hole centres in natural zircon and zircon colouration

open access: yesEuropean Journal of Mineralogy, 2012
Paramagnetic defect centres and their relation to variable types of colouration were studied for eleven natural zircon crystals from three localities in North Carolina (USA), Massif Central (France), and Ural Mountains (Russia) using electron paramagnetic resonance (EPR) and optical absorption spectroscopy.
Mathias Klinger   +4 more
openaire   +1 more source

Assessment of impact of a control die on marginal fidelity of milled zirconia crown copings for finishing and polishing

open access: yesJournal of Prosthodontics, EarlyView.
Abstract Purpose This study evaluated and compared the marginal fidelity of milled zirconia copings before and after finishing and polishing with and without a control die. Materials and Methods This prospective multicenter in vitro trial involved two methods regularly used in two clinics for hybrid and full‐digital workflows.
Marwan Al Akkad   +5 more
wiley   +1 more source

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