6 research outputs found

    Project Achoo: A Practical Model and Application for COVID-19 Detection from Recordings of Breath, Voice, and Cough

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    The COVID-19 pandemic created a significant interest and demand for infection detection and monitoring solutions. In this paper we propose a machine learning method to quickly triage COVID-19 using recordings made on consumer devices. The approach combines signal processing methods with fine-tuned deep learning networks and provides methods for signal denoising, cough detection and classification. We have also developed and deployed a mobile application that uses symptoms checker together with voice, breath and cough signals to detect COVID-19 infection. The application showed robust performance on both open sourced datasets and on the noisy data collected during beta testing by the end users

    Mineralogical, geochemical and isotopic (C, O, Sr) features of the unique high-grade REE-Nb ores from the Tomtor deposit (Arctic Siberia, Russia)

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    The mineralogy (SEM), geochemistry (LA-ICP-MS) and isotopic composition of C, O and Sr in carbonates from uniquely high-grade REE-Nb ores of the Tomtor massif is presented. Testing of the formation conditions for uniquely high-grade ores from the Tomtor deposit was conducted

    Native Gold and Unique Gold–Brannerite Nuggets from the Placer of the Kamenny Stream, Ozerninsky Ore Cluster (Western Transbakalia, Russia) and Possible Sources

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    We carried out a comprehensive study of native gold (morphology, composition, intergrowths, and microinclusions) from alluvial deposits of the Kamenny stream (Ozerninsky ore cluster, Western Transbaikalia, Russia). The study showed that there were four types of native gold, which differed significantly in their characteristics and probably had different primary sources from which placers were formed: gold–quartz, oxidized gold–sulfide, gold–silver, and zones of listvenites with copper–gold and gold–brannerite (Elkon-type). Particular attention was paid to the study of unique, both in size and in composition, gold–brannerite nuggets of the Kamenny stream. It was established that the gold in the gold–brannerite nuggets (GBNs) had wide variations in chemical composition and mineral features. According to them, there were five different fineness types of native gold: 750–800‰; 850–880‰; 880–920‰; 930–960‰; and 980–1000‰. The data obtained indicated a multistage, possibly polygenic, and probably polychronous formation of GBN gold–uranium mineralization. The first stage was the formation of early quartz–nasturanium–gold–W–rutile–magnetite association (Middle–Late Paleozoic age). The second was the crystallization of brannerite and the replacement of an earlier pitchblende with brannerite (Late Triassic (T3)–Early Jurassic (J1) age). The third was the formation of the hematite–barite–rutile–gold association as a result of deformation–hydrothermal processes, which was associated with the appearance of zones of alteration in brannerite in contact with native gold with 8–15 wt.% Ag. The fourth was hypergene or the low-temperature hydrothermal alteration of minerals of early stages with the development of iron hydroxides (goethite) with impurities of manganese, tellurium, arsenic, phosphorus, and other elements. The carbon isotopic composition of an organic substance indicates the involvement of a biogenic carbon source. In the OOC area, there were signs that the composition of the GBNs and the quartz–chlorite–K–feldspar-containing rocks corresponded to Elkon-type deposits

    0Ar/39Ar age of alkaline rocks of Verkhneamginskiy massif (Aldan shield, South Yakutia)

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    Актуальность исследования обусловлена необходимостью расширения ресурсной базы полезных ископаемых, в том числе и золота. Крупные ареалы щелочного магматизма, такие как Алдано-Становой щит, представляют особый интерес, так как частосо щелочными породами ассоциируют золоторудные месторождения, в том числе крупные и гигантские. Верхнеамгинский массив расположен в Верхнеамгинском рудном районе Алдано-Станового щита, который, в свою очередь, входит в состав Чаро-Алданской металогенетической зоны, протянувшейся более чем на 700 км с запада на восток. Характерной особенностью Верхнеамгинкого рудного района является его приуроченность к Амгинской субмеридиональной структурной зоне тектонического меланжа, отделяющей Центрально-Алданский составной террейн с востока от расположенных к западу и югу от нее соответственно Западно-Алданского и Тындинского составных террейнов. Цели: определить основные типы магматических пород Верхнеамгинского массива, изучить особенности строения и состава и выяснить время внедрения различных фаз массива; сравнить полученные результаты с имеющимися геохронологическими данными по мезозойскому магматизму Алданского щита. Методы исследования: петрографические исследования и 40Ar/39Ar датирование методом ступенчатого прогрева по монофракциям флогопитов. Результаты. В результате петрографических исследований показано, что основные фазы мезозойского щелочного магматизма в пределах Верхнеамгинского массива представлены лейкократовыми сиенитами и дайками мезократовых лампрофиров (минетт). Результаты 40Ar/39Ar датирования показали, что образование массива происходило в несколько этапов: (1) 129,1±2,5 млн лет внедрение сиенитов; (2) 117,7±3,4 млн лет внедрение даек лампрофиров. Мезозойский магматизм, проявленный в Верхнеамгинском районе показывает сходные возрастные рубежи с магматическими процессами, проявленными на Алданском щите в мезозойскую эпоху.The relevance of the research is caused by the need to expand mineral resources base, including gold-bearing ores. Large alkaline provinces, like Aldan8Stanovoy shield, are of interest because gold-bearing ores usually related to alkaline rock. They may form large and even giant deposits. Verkhneamginskiy massif is located in Verkhneamginskiy ore field in Aldan-Stanovoy shield. Verkhneamginskiy ore field is the part of large Charo-Aldan metallogenic zone, its length is more than 700 km from west to east. A characteristic feature of the Verkhneamginskiy ore region is its association with the Amginsky submeridional structural zone of the tectonic melange separating the Central Aldan compound terrain in the East from the West Aldan and Tynda composite terrains in the West and South, respectively. The main aim of the research is to detect the main rock types of Verkhneamginskiy massif, to study the features of structure and composition and to identify the age of massif crystallization as well as to compare the results with the available geochronological data on Mesozoic magmatism of the Aldan shield. Methods: petrographic study and 40Ar/39Ar dating by the step heating method by phlogopite monofractions. Results. The main phases of Mesozoic alkaline magmatism are leucocratic syenites and mesocratic lamprophyres. Using the 40Ar/39Ar dating of phlogopite monofraction the authors have determined two discrete impulses: (1) 129,1.5±2,5 Ma emplacement of syenites; (2) 117,7±3,4 Ma emplacement of lamprophyre dikes. Mesozoic magmatism, manifested in Verkhneamginskiy area, demonstrates similar age boundaries with magmatic processes shown in the Aldan shield in the Mesozoic era

    Specific of Stable Carbon Isotopes Determination in Organic-Bearing Sediments

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    Проведено исследование изотопного состава углерода в органосодержащих донных осадках термального озера Фумарольное (кальдера Узон, Камчатка). Представлены результаты изучения изменений δ13С в донных осадках термального озера при последовательном разложении H3PO4 в течение 2 ч, 24 ч и 7 дней. На примере двух образцов показано изменение δ13С во времени и после обработки HCl и H2O2. После обработки HCl значения δ13С изменяются относительно исходных от 1 до 3 ‰, что можно учесть при интерпретации данных. При стандартной процедуре удаления карбоната перекисью водорода выявляется существенная трансформация остаточного С‑содержащего вещества в случае длительной реакции с Н3РО4 при повышенных температурахThe study of the carbon isotopic composition in organic-bearing bottom sediments of the thermal lake Fumarolnoye (Uzon caldera, Kamchatka) has been carried out. The results of studying δ13C changes in the bottom sediments of a thermal lake during the sequential extraction of H3PO4 for 2 hours, 24 hours and 7 days are presented. The change in δ13С with time and after treatment with HCl and H2O2 is shown using two samples as an example. After treatment with HCl, the δ13С values change relative to the initial ones from 1 to 3 ‰, which can be taken into account when interpreting the data. The standard procedure for removing carbonate with hydrogen peroxide reveals a significant transformation of the residual C‑containing substance in the case of a prolonged reaction with H3PO4 at elevated temperature
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