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2022 ◽  
Author(s):  
A. Churakova

Abstract. In this work was investigate the corrosion behavior of the TiNi alloy in a coarse-grained state in inorganic field with different concentration and holding time. An increase in the concentration of the solution leads to a significant acceleration of corrosion processes in the Ti49.1Ni50.9 alloy with a high Ni content, including until the samples are completely dissolved. It was revealed that solutions of 1 M sulfuric and hydrochloric acids after a month's exposure did not change in color and no precipitations were found, while solutions of 5 M hydrochloric and sulfuric acids acquired a violet and then green color, which is due to the predominant release of titanium ions (+4) and nickel (+2).


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7868
Author(s):  
Przemysław Zmitrowicz ◽  
Michał Kawiak ◽  
Paweł Kochmański ◽  
Jolanta Baranowska

K-TIG (Keyhole Tungsten Inert Gas) method is a new, emerging welding technology that offers a significant acceleration of the joining process, even for very thick plates. However, its potential for welding of certain materials is still unknown. Particularly challenging are duplex steels as this technology does not allow the use of a filler material, which is crucial for these steels and for weld joint microstructure adjustment. In order to demonstrate the suitability of this technology for single-pass welding of 1.4462 duplex steel detailed studies of the microstructure of the weld joints obtained for different linear energies were carried out and discussed with respect to their mechanical properties. According to the results obtained, the heat-affected zone (HAZ) shows a microstructure similar to the HAZ of duplex steel welded with the traditional TIG multi-pass methods. However, the weld, due to the lack of filler material, had a microstructure different to that typical for duplex steel welded joints and was also characterized by an increased content of ferrite. However, all joints, both in terms of microstructure and mechanical properties, met the requirements of the relevant standards. Moreover, the K-TIG process can be carried out in the linear energy range typical of duplex steel welding, although further optimization is needed.


2021 ◽  
Vol 15 (12) ◽  
pp. 5345-5369
Author(s):  
Fabian Fleischer ◽  
Florian Haas ◽  
Livia Piermattei ◽  
Madlene Pfeiffer ◽  
Tobias Heckmann ◽  
...  

Abstract. Permafrost is being degraded worldwide due to the change in external forcing caused by climate change. This has also been shown to affect the morphodynamics of active rock glaciers. We studied these changes, depending on the analysis, on nine or eight active rock glaciers, respectively, with different characteristics in multiple epochs between 1953 and 2017 in Kaunertal, Austria. A combination of historical aerial photographs and airborne laser scanning data and their derivatives were used to analyse surface movement and surface elevation change. In general, the studied landforms showed a significant acceleration of varying magnitude in the epoch 1997–2006 and a volume loss to variable degrees throughout the investigation period. Rock glaciers related to glacier forefields showed significantly higher rates of subsidence than talus-connected ones. Besides, we detected two rock glaciers with deviating behaviour and one that showed an inactivation of its terminal part. By analysing meteorological data (temperature, precipitation and snow cover onset and duration), we were able to identify possible links to these external forcing parameters. The catchment-wide survey further revealed that, despite the general trend, timing, magnitude and temporal peaks of morphodynamic changes indicate a slightly different sensitivity, response or response time of individual rock glaciers to fluctuations and changes in external forcing parameters.


2021 ◽  
Vol 2096 (1) ◽  
pp. 012199
Author(s):  
E Myasnikov

Abstract In this paper, we address the problem of fast nearest neighbour search. Unfortunately, well-known indexing data structures, such as vp-trees perform poorly on some datasets and do not provide significant acceleration compared to the brute force approach. In the paper, we consider an alternative solution, which can be applied if we are not interested in some fraction of distant nearest neighbours. This solution is based on building the forest of vp-tree-like structures and guarantees the exact nearest neighbour search in the epsilon-neighbourhood of the query point.


2021 ◽  
Vol 43 (3) ◽  
pp. 38-39
Author(s):  
E. N. Korovaev ◽  
I. N. Gimadeev

The test for the hydrophilicity of tissues according to McClure, which is reduced to the intradermal administration of 0.2 saline and monitoring the time of resorption of the blister formed in this case, has already been used for rheumatism in children (O. K-Miss), and its acceleration in the acute period has been shown rheumatism up to 15-40 minutes, whereas normally its time ranges from 30 minutes. in infants up to 52 minutes. - at an older age (MS Maslov), The most significant acceleration of it was observed in violent rheumatic arthritis and in severe acute period with severe symptoms of heart failure.


F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 1034
Author(s):  
Anna Siniarska ◽  
Napoleon Wolański

Background: Maya families suffered greatly during the henequen industry in the Yucatan, but the lives of the Maya women at the time were perhaps worse than anywhere in the world. Changes in Maya body height over the 20th century were assessed in order to show secular changes. The use of the sexual dimorphism index (SDI) allowed for the evaluation of the living conditions prevailing during the existence of the henequen haciendas to the Mexican revolution and a gradual improvement of these conditions by the end of the 20th century. Methods: In 1994, 364 men and 320 women aged 20-98 years were studied in Merida, Yucatan, Mexico. They were divided into six age groups and by gender: 20-29, 30-39, 40-49, 50-59, 60-69 and 70+ years. Stature for both genders, and age at menarche for women were considered. SDI in stature was calculated to assess living conditions. Results: There were smaller (0.25 cm/10 years) changes in height in men than in women (0.9 cm/10 years) and no significant changes in acceleration of maturation. SDI results showed changes from 9.9 to 7.6, and this may indicate a constant, but very small improvement of living conditions. The age at menarche of women did not show statistically significant acceleration with age. Conclusions: In the colonial period of the late 19th century until the Mexican Revolution, women were worse off than men. Previous research has shown that when living conditions change, men always react faster than women, e.g. by lowering or increasing body height. Our study of the Maya population in the 20th century showed otherwise; female height increased more than male height. This may reflect that the living conditions of Maya men have not changed over the 20th century, but have improved for women.


2021 ◽  
Vol 21 (16) ◽  
pp. 12631-12647
Author(s):  
Yi Yin ◽  
Frederic Chevallier ◽  
Philippe Ciais ◽  
Philippe Bousquet ◽  
Marielle Saunois ◽  
...  

Abstract. After stagnating in the early 2000s, the atmospheric methane growth rate has been positive since 2007 with a significant acceleration starting in 2014. While the causes for previous growth rate variations are still not well determined, this recent increase can be studied with dense surface and satellite observations. Here, we use an ensemble of six multi-species atmospheric inversions that have the capacity to assimilate observations of the main species in the methane oxidation chain – namely, methane, formaldehyde, and carbon monoxide – to simultaneously optimize both the methane sources and sinks at each model grid. We show that the surge of the atmospheric growth rate between 2010–2013 and 2014–2017 is most likely explained by an increase of global CH4 emissions by 17.5±1.5 Tg yr−1 (mean ± 1σ), while variations in the hydroxyl radicals (OH) remained small. The inferred emission increase is consistently supported by both surface and satellite observations, with leading contributions from the tropical wetlands (∼ 35 %) and anthropogenic emissions in China (∼ 20 %). Such a high consecutive atmospheric growth rate has not been observed since the 1980s and corresponds to unprecedented global total CH4 emissions.


Author(s):  
Min Huang ◽  
Xian Wang ◽  
Guanjie Xing ◽  
Chenchen Meng ◽  
Yunchao Li ◽  
...  

Leukemia ◽  
2021 ◽  
Author(s):  
Richard Lewis ◽  
H. Carlo Maurer ◽  
Nikita Singh ◽  
Irene Gonzalez-Menendez ◽  
Matthias Wirth ◽  
...  

AbstractAberrant CXCR4 activity has been implicated in lymphoma pathogenesis, disease progression, and resistance to therapies. Using a mouse model with a gain-of-function CXCR4 mutation (CXCR4C1013G) that hyperactivates CXCR4 signaling, we identified CXCR4 as a crucial activator of multiple key oncogenic pathways. CXCR4 hyperactivation resulted in an expansion of transitional B1 lymphocytes, which represent the precursors of chronic lymphocytic leukemia (CLL). Indeed, CXCR4 hyperactivation led to a significant acceleration of disease onset and a more aggressive phenotype in the murine Eµ-TCL1 CLL model. Hyperactivated CXCR4 signaling cooperated with TCL1 to cause a distinct oncogenic transcriptional program in B cells, characterized by PLK1/FOXM1-associated pathways. In accordance, Eµ-TCL1;CXCR4C1013G B cells enriched a transcriptional signature from patients with Richter’s syndrome, an aggressive transformation of CLL. Notably, MYC activation in aggressive lymphoma was associated with increased CXCR4 expression. In line with this finding, additional hyperactive CXCR4 signaling in the Eµ-Myc mouse, a model of aggressive B-cell cancer, did not impact survival. In summary, we here identify CXCR4 hyperactivation as a co-driver of an aggressive lymphoma phenotype.


2021 ◽  
Vol 13 (14) ◽  
pp. 7986
Author(s):  
František Pollák ◽  
Michal Konečný ◽  
Deniss Ščeulovs

In the days leading to the outbreak of the COVID-19 pandemic, open innovations in the form of the deployment of digital marketing tools in the management portfolio were an option; in a time of forced closing of economies, they suddenly became a necessity. The aim of the comprehensive research, in which the presented study is prepared, is to describe the changes in e-consumer behavior that occurred in the market during the COVID-19 pandemic. The presented study examines the seasonal and regional specifics that characterize the markets of Central and Eastern Europe. In a sample of almost 14,000,000 Facebook users, the user interactions with ten selected representatives of the e-commerce sector were recorded daily during the 2020/2021 Christmas season lasting 49 days. By analyzing the nature and timing of interactions, it was possible to identify the geographical specifics of e-consumer behavior, as well as basic seasonality indicators based on a comparison with the reference period of the first half of 2020. The synthesis of the findings provided a knowledge base for compiling a preliminary version of the model of the COVID-19 pandemic impact on e-consumer behavior. In terms of changes in e-consumer behavior, it can be stated that the step change in e-behavior patterns caused by the pandemic merges with pre-pandemic behavior patterns. In general, it can be stated that the evolutionary process of the transition from offline to online the COVID-19 pandemic appears to be a significant acceleration factor of inevitable changes.


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