Oxidative capacity and hemolytic activity of settled dust from moisture‐damaged schools

Exposure to moisture‐damaged indoor environments is associated with adverse respiratory health effects, but responsible factors remain unidentified. In order to explore possible mechanisms behind these effects, the oxidative capacity and hemolytic activity of settled dust samples (n = 25) collected from moisture‐damaged and non‐damaged schools in Spain, the Netherlands, and Finland were evaluated and matched against the microbial content of the sample. Oxidative capacity was determined with plasmid scission assay and hemolytic activity by assessing the damage to isolated human red blood cells. The microbial content of the samples was measured with quantitative PCR assays for selected microbial groups and by analyzing the cell wall markers ergosterol, muramic acid, endotoxins, and glucans. The moisture observations in the schools were associated with some of the microbial components in the dust, and microbial determinants grouped together increased the oxidative capacity. Oxidative capacity was also affected by particle concentration and country of origin. Two out of 14 studied dust samples from moisture‐damaged schools demonstrated some hemolytic activity. The results indicate that the microbial component connected with moisture damage is associated with increased oxidative stress and that hemolysis should be studied further as one possible mechanism contributing to the adverse health effects of moisture‐damaged buildings.     

Assessing landscape preferences: a visual choice experiment in the agricultural region of Märkische Schweiz,Germany

Natural amenities and the aesthetic value of agricultural landscapes are important territorial assets for improving rural tourism and the quality of the living environment. To identify which characteristics shape the visual quality of a landscape, a stated-preference survey was conducted (N = 200) using photorealistic landscape visualisations of four different landscape attributes (point green elements, linear green elements, crop diversity and presence of livestock). We estimated respondents’ preferences for landscape attributes, examined the extent of agreement among respondents and identified socio-economic factors influencing their responses. Results revealed that point elements had the highest general preference. About 70% of respondents preferred diverse and highly structured landscapes, while about 30% of respondents had opposing preferences. Preferences were also found to be dependent on the individual’s sociocultural background, such as their level of education, gender or age. These results can help to improve the multi-objective targeting of policies by including an aesthetic value perspective.     

Immobilization of arsenic in a tailings material by ferrous iron treatment

Weathering and internal dissolution processes in mining waste materials may mobilize elevated levels of arsenic (As), contaminating ground and surface waters. Treating the polluted waters with iron oxyhydroxides is an established remediation method. By contrast, little knowledge is available to stabilize As in source materials by treating it with Fe precipitates and, on this way, to prevent the generation of polluted waters. In the present work the efficiency of Fe(II) treatment on As immobilization in a tailings material (TM) was studied with regard to the Fe:As molar ratio, the influence of CaCO3 amendment, and the As desorption at continued intensive leaching of Fe-treated TM. Fe precipitates were created by aerobic treatment of TM with Fe(II)sulfate at several Fe:As molar ratios with or without adding CaCO3, followed by aging the Fe-treated TM. The As retention in the treated tailings was studied by 4-fold elution with water, and the As desorption kinetics was examined by suspension leaching in laboratory microcosms over 3 weeks. Fe(II) treatment of TM reduced the water-extractable total As to <10 microg/L as the Fe:As molar ratio increased from 0 to 8. The water-soluble As of Fe-treated tailings could be reduced to 10-30 microg/L also under conditions of intensive leaching. Stabilizing the pH with CaCO3 resulted in consistently higher As release. The As desorption data followed the first-order kinetics in the early time stages of the desorption whereas at longer times the parabolic diffusion model was valid.     

Analysis of carotenoids and vitamin E in selected oilseeds,press cakes and oils

Carotenoids and vitamin E in oils from the market – 6 rapeseed and 6 sunflower oils, half of each cold pressed and refined – and in the oils of rape, sunflower, flax and safflower as well as the respective seeds and press cakes from a local oil mill were quantified by HPLC. Furthermore, a photometric determination of carotenoid content was tested and checked against the chromatographic method. In the cold pressed oils minor amounts of xanthophylls (all‐E)‐lutein and (all‐E)‐zeaxanthin were determined. With exception of traces of (all‐E)‐β‐carotene in cold‐pressed rapeseed oil this provitamin A active compound did not occur. Cold pressed rapeseed oils contained 0.5–1.5 mg total carotenoids/100 g which was manifold the content of the further oils. Vitamin E was found in all vegetable oils at plant‐typic tocopherol patterns. The photometric determination of carotenoids resulted in significantly higher concentrations compared to the HPLC. This overestimation bases on the carotenoid pattern which was validated by comparison with known high‐carotenoid materials, i.e. maize flour with an abundant amount of xanthophylls and carrots with an abundant amount of carotenes.     

Interfacial microstructure and shear strength of reactive air brazed oxygen transport membrane ceramic–metal alloy joints

To fabricate a multi-layered structure for maximizing oxygen production, oxygen transport membrane (OTM) ceramics need to be joined or sealed hermetically metal supports for interfacing with the peripheral components of the system. Therefore, in this study, Ag–10 wt% CuO was evaluated as an effective filler material for the reactive air brazing of dense Ce_0.9Gd_0.1O_2–δ–La_0.7Sr_0.3MnO_3±δ (GDC–LSM) OTM ceramics. Thermal decomposition in air and wetting behavior of the braze filler was performed. Reactive air brazing was performed at 1050 °C for 30 min in air to join GDC–LSM with four different commercially available high temperature-resistant metal alloys, such as Crofer 22 APU, Inconel 600, Fecralloy, and AISI 310S. The microstructure and elemental distribution of the ceramic-ceramic and ceramic-metal interfaces were examined from polished cross-sections. The mechanical shear strength at room temperature for the as-brazed and isothermally aged (800 °C for 24 h) joints of all the samples was compared. The results showed that the strength of the ceramic-ceramic joints was decreased marginally by aging; however, in the case of metal-ceramic joints, different decreases in strengths were observed according to the metal alloy used, which was explained based on the formation of different oxide layers at the interfaces.     

Synthesis and characterization of calcium phosphate coatings on Nitinol

In recent years, coating of metal orthopedic implants with bioactive layers to promote fixation with bones has become increasingly common. Calcium phosphate coatings on the Nitinol surface were formed using two low-temperature methods: sol–gel and electrochemically assisted deposition. The coatings formed were characterized using: X-ray diffraction analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. Cyclic voltammetry studies were carried out in the deposition solution to determine parameters for electrodeposition and to understand electrochemistry of deposition. The barrier properties and corrosion resistance of coatings were tested in the physiological Hanks’ solution using electrochemical impedance spectroscopy. The sol–gel deposited coating consisted of two phases, hydroxyapatite and tricalcium phosphate (TCP). Apatite coatings containing TCP offered the opportunity to create a grafting material with high bioactivity and bioresorbility. The electrodeposited coating consisted of Ca-deficient HAp which resembles to biological HAp.     

Steam pretreatment of dry and ensiled industrial hemp for ethanol production

Biomass can be converted into liquid and gaseous biofuels with good efficiency. In this study, the conversion of industrial hemp (Cannabis sativa L.), a biomass source that can be cultivated with a high biomass yield per hectare, was used. Steam pretreatment of dry and ensiled hemp was investigated prior to ethanol production. The pretreatment efficiency was evaluated in terms of sugar recovery and polysaccharide conversion in the enzymatic hydrolysis step. For both materials, impregnation with 2% SO₂ followed by steam pretreatment at 210 °C for 5 min were found to be the optimal conditions leading to the highest overall yield of glucose. Simultaneous saccharification and fermentation experiments carried out with optimised pretreatment conditions resulted in ethanol yields of 163 g kg^?1 ensiled hemp (dry matter) (71% of the theoretical maximum) and 171 g kg^?1 dry hemp (74%), which corresponds to 206–216 l Mg^?1 ethanol based on initial dry material.