Overview of the MOSAiC expedition - Atmosphere

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore cross-cutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic

The Proposal of Stock Items Reconfiguration on the Basis of Cluster Analysis Results

AbstractThe submitted article is focused on the field of distribution logistics with the aim of cluster analysis application as a tool for creation of groups of similar stock items (clusters) leading to speed up the company's reactions on customers’ requirements. When creating the groups (clusters) of stock items by using cluster analysis it is necessary to have information about the process which directly follows. It means that in case of analysis of distribution centre stock items, the input information are the data of product distribution of the previous period or distribution plan for the future period. Changes in distribution play an essential role in clustering that is why it is appropriate to use distribution data from several periods not just one. The output of the process of finished goods stock clustering by using hierarchical methods of cluster analysis is dendrogram. Consequently based on problem solver's subjective opinion the optimal numbers of clusters are selected and are incorporated into the proposal of finished goods warehouse layout reconfiguration. The result of cluster analysis in the form of finished products clusters is possibly applicable in other business processes, for instance production cells creation, raw materials warehouse layout reconfiguration and many others because the criterion of cluster creation are customers’ requirements which is determining criterion in the entire process of customer oriented companies

Amorphous versus Crystalline Li3PS4Li_3PS_{4}: Local Structural Changes during Synthesis and Li Ion Mobility

Glass–ceramic solid electrolytes have been reported to exhibit high ionic conductivities. Their synthesis can be performed by crystallization of mechanically milled Li2S–P2S5 glasses. Herein, the amorphization process of Li$_2$S–P$_2$S$_5$ (75:25) induced by ball milling was analyzed via X-ray diffraction (XRD), Raman spectroscopy, and $^{31}$P magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy. Several structural building blocks such as [P$_4$S$_{10}$], [P$_2$S$_6$]$^{4–}$, [P2S7]$^{4–}$, and [PS$_4$]$^{3–}$ occur during this amorphization process. In addition, high-temperature XRD was used to study the crystallization process of the mechanically milled Li$_2$S–P$_2$S$_5$ glass. Crystallization of phase-pure β-Li$_3$PS$_4$ was observed at temperatures up to 548 K. The kinetics of crystallization was analyzed by integration of the intensity of the Bragg reflections. $^7$Li NMR relaxometry and pulsed field-gradient (PFG) NMR were used to investigate the short-range and long-range Li$^+$ dynamics in these amorphous and crystalline materials. From the diffusion coefficients obtained by PFG NMR, similar Li$^+$ conductivities for the glassy and heat-treated samples were calculated. For the glassy sample and the glass–ceramic β-Li$_3$PS$_4$ (calcination at 523 K for 1 h), a Li$^+$ bulk conductivity σLi of 1.6 × 10$^{–4}$ S/cm (298 K) was obtained, showing that for this system a well-crystalline material is not essential to achieve fast Li-ion dynamics. Impedance measurements reveal a higher overall conductivity for the amorphous sample, suggesting that the influence of grain boundaries is small in this case

Fabrication and In Vitro Characterization of Novel Hydroxyapatite Scaffolds 3D Printed Using Polyvinyl Alcohol as a Thermoplastic Binder

This paper presents a proof-of-concept study on the biocolonization of 3D-printed hydroxyapatite scaffolds with mesenchymal stem cells (MSCs). Three-dimensional (3D) printed biomimetic bone structure made of calcium deficient hydroxyapatite (CDHA) intended as a future bone graft was made from newly developed composite material for FDM printing. The biopolymer polyvinyl alcohol serves in this material as a thermoplastic binder for 3D molding of the printed object with a passive function and is completely removed during sintering. The study presents the material, the process of fused deposition modeling (FDM) of CDHA scaffolds, and its post-processing at three temperatures (1200, 1300, and 1400 °C), as well it evaluates the cytotoxicity and biocompatibility of scaffolds with MTT and LDH release assays after 14 days. The study also includes a morphological evaluation of cellular colonization with scanning electron microscopy (SEM) in two different filament orientations (rectilinear and gyroid). The results of the MTT assay showed that the tested material was not toxic, and cells were preserved in both orientations, with most cells present on the material fired at 1300 °C. Results of the LDH release assay showed a slight increase in LDH leakage from all samples. Visual evaluation of SEM confirmed the ideal post-processing temperature of the 3D-printed FDM framework for samples fired at 1300 °C and 1400 °C, with a porosity of 0.3 mm between filaments. In conclusion, the presented fabrication and colonization of CDHA scaffolds have great potential to be used in the tissue engineering of bones

Overview of the MOSAiC expedition:atmosphere

Abstract With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore crosscutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic