Bemessung eines Stützbauwerks nach Eurocode — Teil 2: Erdbebenbemessung

Dieser Beitrag behandelt den Erdbebennachweis für die Bemessung von Gewichtsmauern aus Beton und Stahlbeton nach Eurocode 2 (EN 1992‐x), Eurocode 7 (EN 1997‐1) und Eurocode 8 (EN 1998‐x) anhand eines durchgerechneten Beispiels. Design of concrete retaining structures according to Eurocode standards — Part 2: Earth quake design. This contribution treats the design of concrete retaining structures under earth quake impact based on Eurocode 2 (EN 1992‐x), Eurocode 7 (EN 1997‐1) and Eurocode 8 (EN 1998‐x) by means of an application example.     

Contribution of volatile precursor substances to the flux of perfluorooctanoate to the Arctic

Perfluorooctanoate (PFO) has recently been found in remote ocean water and Arctic samples, despite not having been used in significant quantities in remote areas. Two main scenarios for the contamination of the Arctic by PFO have been suggested: (i) direct emissions of PFO and oceanic transport to the Arctic and (ii) emissions of volatile precursor substances that are transported and oxidized in the atmosphere to form PFO, which is subsequently deposited to the Arctic. Focusing on the atmospheric transport pathway, we compare the importance of fluorotelomer alcohols (FTOHs) and perfluorooctyl sulfonamidoethanols (FOSEs) for PFO deposition to the Arctic. Using a global scale multispecies mass balance model, we simultaneously calculate the transport, degradation, partitioning, and deposition of precursor substances, intermediate degradation products, and PFO and compare model results to field measurements. Prior to 2002, the modeled deposition fluxes of PFO to the Arctic originating from FOSEs and FTOHs are of a similar magnitude, and total estimated deposition compares well with deposition measurements for Arctic ice cores. However, the model underpredicts recent measurements of FOSEs in Arctic air, indicating that there may be additional emissions not taken into account. Using Monte Carlo calculations we quantify the uncertainties in our model results and identify that emission estimates, degradation yields, and degradation rate constants are the most influential input parameters controlling the estimated deposition of PFO to the Arctic.     

Catechin and epicatechin in testa and their association with bioactive compounds in kernels of cashew nut (Anacardium occidentale L.)

Catechins in testa and bioactive compounds in testa-free and testa-containing kernels of cashew nuts were analysed. The cashew nut testa contained (+)-catechin and (−)-epicatechin with concentrations of 5.70 and 4.46 g per kg DM, respectively. Testa-containing kernels revealed significantly higher levels of β-carotene (218 vs. 89.6 μg/kg DM), lutein (525 vs. 292 μg/kg DM), and α-tocopherol (10.1 vs. 2.4 mg/kg DM), similar amounts of zeaxanthin (7.0 vs. 7.1 μg/kg DM), γ-tocopherol (10.6 vs. 10.1 mg/kg DM), stearic acid (41 vs. 43 g/kg DM), oleic acid (214 vs. 219 g/kg DM) and linoleic acid (69 vs. 62 g/kg DM), but a lower concentration of thiamine (3.0 vs. 10.7 mg/kg DM) in comparison to testa-free samples. The testa-containing kernels provide high amounts of catechins and higher concentrations of β-carotene, lutein and α-tocopherol than do testa-free cashew nut kernels. This could have potential health benefits for consumers.     

Insight in Superiority of the Hydrophobized Gentamycin in Terms of Antibiotics Delivery to Bone Tissue

Bone infections are a serious problem to cure, as systemic administration of antibiotics is not very effective due to poor bone vascularization. Therefore, many drug delivery systems are investigated to solve this problem. One of the potential solutions is the delivery of antibiotics from poly(L-actide-co-glycolide) (PLGA) nanoparticles suspended in the gellan gum injectable hydrogel. However, the loading capacity and release kinetics of the system based on hydrophilic drugs (e.g., gentamycin) and hydrophobic polymers (e.g., PLGA) may not always be satisfying. To solve this problem, we decided to use hydrophobized gentamycin obtained by ion-pairing with dioctyl sulfosuccinate sodium salt (AOT). Herein, we present a comparison of the PLGA nanoparticles loaded with hydrophobic or hydrophilic gentamycin and suspended in the hydrogel in terms of physicochemical properties, drug loading capacity, release profiles, cytocompatibility, and antibacterial properties. The results showed that hydrophobic gentamycin may be combined in different formulations with the hydrophilic one and is superior in terms of encapsulation efficiency, drug loading, release, and antibacterial efficacy with no negative effect on the NPs morphology or hydrogel features. However, the cytocompatibility of hydrophobic gentamycin might be lower, consequently more extensive study on its biological properties should be provided to evaluate a safe dose.     

Catalytic Performance and Sulfur Dioxide Resistance of One-Pot Synthesized Fe-MCM-22 in Selective Catalytic Reduction of Nitrogen Oxides with Ammonia (NH3-SCR)—The Effect of Iron Content

The catalytic performance of Fe-catalysts in selective catalytic reduction of nitrogen oxides with ammonia (NH₃-SCR) strongly depends on the nature of iron sites. Therefore, we aimed to prepare and investigate the catalytic potential of Fe-MCM-22 with various Si/Fe molar ratios in NH₃-SCR. The samples were prepared by the one-pot synthesis method to provide high dispersion of iron and reduce the number of synthesis steps. We have found that the sample with the lowest concentration of Fe exhibited the highest catalytic activity of ca. 100% at 175 °C, due to the abundance of well-dispersed isolated iron species. The decrease of Si/Fe limited the formation of microporous structure and resulted in partial amorphization, formation of iron oxide clusters, and emission of N₂O during the catalytic reaction. However, an optimal concentration of Fe_xO_y oligomers contributed to the decomposition of nitrous oxide within 250–400 °C. Moreover, the acidic character of the catalysts was not a key factor determining the high conversion of NO. Additionally, we conducted NH₃-SCR catalytic tests over the samples after poisoning with sulfur dioxide (SO₂). We observed that SO₂ affected the catalytic performance mainly in the low-temperature region, due to the deposition of thermally unstable ammonium sulfates.     

Synthesizing verified components for cyber assured systems engineering

Software and Systems Modeling - Safety-critical systems such as avionics need to be engineered to be cyber resilient meaning that systems are able to detect and recover from attacks or safely...     

Chemical Stability and Hydrogen Reaction Behavior of SmCo 2:17-Type Permanent Magnets

Herein, the reaction behavior and chemical stability of two commercially available SmCo 2:17-type sintered magnets with nominal composition of Sm_23.75Co_48.67Fe_balCu_4.91Zr_2.37 and Sm_24.95Co_48.80Fe_balCu_4.46Zr_2.68 (wt%) are investigated. The magnets are placed in a hydrogen atmosphere with systematically varied pressure, exposure time, and temperature ranging from 1–11 bar, 2–10 d, and 25–500 °C, respectively. Hydrogen content, magnetic properties, microstructure, and lattice constants are characterized in detail. It is found that for short exposure times like 2 d an activation temperature of 120 °C is necessary to initiate the reaction and to increase the amount of hydrogen in the Sm–Co material. Hydrogen absorption starts at lower temperatures with longer exposure times. An increase in exposure time, temperature, or pressure leads to a higher hydrogen content and a decrease in remanence B_r, energy product (BH)_max, and coercivity H_cB. Lattice expansion, estimated by X-ray diffraction analysis, correlates with the increasing amount of hydrogen in the Sm–Co magnets. With respect to all varied parameters under investigation, the exposure temperature has the highest impact on the observed property changes followed by reaction time and H₂ pressure.     

Verstärkung konstruktiver Details von Brettschichtholzträgern mit Glasfasergewebe

Glass fiber reinforced details of timber beams. The mechanical behaviour of wood is characterized by the difference of its strength and stiffness in fiber direction and in direction perpenticulare to the grain. In the case of a notch the load carrying capacity decreases. The use of plywood and glued in rods and self drilling screwes improve the properties perpenticulare to the grain. In this paper the use of glass fiber products orientated cross to the wood grains is tested.