TY - JOUR A1 - Mishra, Biswajit A1 - Kumar Singh, Amit A1 - Shankar Mahobia, Girija T1 - Hydrogen reduction studies of low-grade multimetallic magnetite ore pellets N2 - The hydrogen reducibility of pellets made from a low-grade multimetallic magnetite ore (Fe content ∼ 45 %) was investigated in the present study. Pellets were reduced in a horizontal tube furnace at temperatures ranging from 973 K to 1173 K for 1 to 60 min. Pure Hydrogen (H2) gas (99.9 %) at three flow rates of 0.25 L/min, 0.5 L/min, and 1 L/min were blown during the reduction process. A maximum reduction degree of 94.07 %, metallization ratio of 0.925, and H2 gas utilization of 9.01 % were obtained at a temperature and a reduction time of 1173 K and 60 min, respectively. In order to optimize the hydrogen utilization, a reduction temperature of 1173 K, a reduction time of 45 min, and a gas flow rate of 0.25 L/min were selected, resulting in a reduction degree and metallization ratio of 90 % and 0.89, respectively. The cold crushing strength (CCS) of the reduced pellets initially decreased and then increased slightly, exhibiting behavior similar to high-grade ores. Imputities like SiO2, Al2O3, and MgO, present in the low grade ores are found to control the porosity of the pellets, directly affecting the CCS and reducibility of the pellets. KW - Cold Crushing Strength KW - Low-grade iron ores KW - Hydrogen Reduction KW - Metallization ratio KW - Gangue elements PY - 2024 DO - https://doi.org/10.1016/j.mineng.2024.108823 SN - 0892-6875 VL - 215 SP - 1 EP - 14 PB - Elsevier B.V. AN - OPUS4-62539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - da Silva, Luiza Helena Bueno A1 - Goes, Aryel C. A1 - Rodrigues, Andre A1 - Fourcassié, Vincent A1 - McMahon, Dino Peter A1 - Haifig, Ives T1 - Social immune response reflects infection progression in a soldierless termite N2 - Social interactions represent a double-edged sword. On one hand, sociality can facilitate sanitary collective behaviours; on the other hand, it creates opportunities for pathogen transmission. In termites, sanitary behaviours can entail a rescuing strategy at early stages of infection, followed by the elimination at later stages. We explored whether the neotropical soldierless species Anoplotermes pacificus employs a progressive approach towards infected nestmates, with different behavioural displays depending on the infection stage. We infected A. pacificus workers with the fungus Metarhizium anisopliae and incubated them for 2, 12, 15 and 20 h, corresponding to infection progression and, therefore, severity. Infected termites were placed with naïve nestmates and their behaviours were recorded for 3 h. Fungus-infected termites triggered up to fourfold higher levels of sanitary behaviour than in non-infected termites. Antennation behaviour decreased during the observation period, whereas sanitary behaviour, which we defined as directed behaviour towards the focal termite involving mouthparts, increased in frequency as incubation duration increased. Sanitary behaviour therefore appears to be a strategy for colony disinfection, which varies in intensity according to infection status, ultimately resulting in the immobilisation of infected individuals at later stages of infection. Alarm responses were also up to three times more frequent in treatment than in control groups and did not vary with incubation duration. A. pacificus workers therefore identify, communicate and respond to pathogen-treated individuals in a progressive manner, indicating that collective responses in this species are also significantly shaped by the stage of infection. By progressively modulating their social immune responses, termites may be able to optimize resource allocation within the colony by balancing the risk of individual infection versus protection of the group. KW - Anoplotermes pacificus KW - Isoptera KW - Infection KW - Metarhizium KW - Social immunity PY - 2024 DO - https://doi.org/10.1007/s00265-024-03556-2 VL - 79 IS - 1 SP - 1 PB - Springer Science and Business Media LLC AN - OPUS4-62397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Roesch, Philipp A1 - Wittwer, Philipp A1 - Sommerfeld, Thomas A1 - Riedel, Maren A1 - Leube, Peter A1 - Kalbe, Ute A1 - Schoknecht, Ute A1 - Simon, Franz-Georg T1 - Per- and Polyfluoroalkyl Substances (PFAS) in Ski Waxes and Snow from Cross-Country Skiing in Germany - Comparative study of Sum Parameter and Target Analysis N2 - Per- and polyfluoroalkyl substances (PFAS) are often environmentally exposed via discharge through human consumer products, such as ski waxes. In our study we analyzed various ski waxes from the 1980s and 2020s, to determine both the sum parameter values total fluorine (TF), extractable organically bound fluorine (EOF), hydrolysable organically bound fluorine (HOF) as well as targeted PFAS analysis. This showed that modern high-performance waxes contain up to 6 % TF, but also PFAS-free labelled ski waxes contain traces of PFAS with EOF/HOF values in the low mg kg-1 range. With the ban of all fluorine-based waxes with the start of the 2023/2024 winter season this will probably change soon. Moreover, we applied our analysis methods to snow samples from a frequently used cross country ski trail (Kammloipe) in the Ore Mountain region in Germany, assessing the potential PFAS entry/discharge through ski waxes. Melted snow samples from different spots were analyzed by the adsorbable organically bound fluorine (AOF) sum parameter and PFAS target analysis and confirmed the abrasion of the ski waxes into the snow. Moreover, on a PFAS hotspot also soil samples were analyzed, which indicate that PFAS from the ski waxes adsorb after snow melting into the soil. KW - Combustion Ion Chromatography KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Consumer Products PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612760 DO - https://doi.org/10.1016/j.hazadv.2024.100484 VL - 16 SP - 1 EP - 5 PB - Elsevier B.V. AN - OPUS4-61276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roesch, Philipp A1 - Schinnen, Andrea A1 - Riedel, Maren A1 - Sommerfeld, Thomas A1 - Sawal, G. A1 - Bandow, N. A1 - Vogel, Christian A1 - Kalbe, Ute A1 - Simon, Franz-Georg T1 - Investigation of pH-dependent extraction methods for PFAS in (fluoropolymer-based) consumer products: A comparative study between targeted and sum parameter analysis N2 - Here, we report a comparative study of different sum parameter analysis methods for the extraction of per- and polyfluoroalkyl substances (PFAS) from manufactured consumer products, which can be measured by combustion ion chromatography (CIC). Therefore, a hydrolysis-based extraction method was further developed, which accounts for the addition of hydrolyzable covalently bound polyfluoroalkylated side-chain polymers (SFPs) to the extractable organic fluorine portion of the mass balance proposed as "hydrolyzable organically bound fluorine" (HOF). To test this hypothesis, the method was applied to 39 different consumer products containing fluoropolymers or monomeric PFAS taken from four different categories: outdoor textiles, paper packaging, carpeting, and permanent baking sheets. We also evaluated the method's efficiency by extracting four synthesized fluorotelomer polyacrylate reference compounds. The total fluorine (TF) and extractable organically bound fluorine (EOF) values were measured through CIC using established protocols. The TF values ranged from sub-ppb to %-levels, depending on the compound class. All samples showed results for hydrolyzed organofluorine (HOF) between 0.03 and 76.3 μg/g, while most EOF values were lower (