Kulturhistorische Museen in Westfalen (1900 - 1950): Geschichtsbilder, Kulturströmungen, Bildungskonzepte

Griepentrog M. Kulturhistorische Museen in Westfalen (1900 - 1950): Geschichtsbilder, Kulturströmungen, Bildungskonzepte. Forschungen zur Regionalgeschichte ; Bd. 24. Paderborn: Schöningh; 1998

Aircraft DC networks characterization and adaptive stage design for PLC use

Aerospace industry is moving towards a more electric aircraft (MEA) or even an all-electric aircraft (AEA), which will incite the focus on reducing the total harness mass and complexity, thus employing powerline communication (PLC) technique seems to be a potential solution to be implemented for airborne uses. This paper explores the feasibility to implement PLC technology over aircraft DC powerline, fed by switched-mode power supply. First, a channel characterization and analysis were conducted, also an adaptive stage was discussed and designed to transmit the data over an already existing powerline. Furthermore, the channel capacity was estimated along with the required data signal level. This study investigates also a real-case context with the use of switched-mode dc/dc converter which effect the PLC performance and signal integrity. Eventually, PLC implementation and tests were conducted as well as discussed from latency, bit error rate (BER) and EMC compliance perspective with the RTCA DO-160G standard requirements

Design of PCB-based planar coil inductive coupler

The coupling method used to superimpose and separate the data signal to and from the powerline plays a crucial role concerning the channel frequency response, the coupling efficiency, and also preserving the signal integrity against the peaks and notches caused by reflections, which will cancel certain carrier frequencies at the receiver. Furthermore, the coupling unit should be bi-directional to allow the signals coupling regardless the direction of data flow, likewise it needs to accomplish galvanic isolation together with transient protection, and offers more degrees of freedom to impedance-matching, as well as allocating less space and achieve high bandwidth for broadband coupling. This paper discusses an approach to pursue toward designing a printed-circuit board (PCB)-based planar coil inductive coupler with wide bandwidth for data transfer.The designed coupler will eventually be used to implement powerline communication (PLC) adequately for airborne use, where a real-case context study was investigated, also PLC implementation and tests were conducted as well as discussed from latency, bit error rate (BER) and electromagnetic compatibility (EMC) compliance perspective with the RTCA DO-160G standard requirements

Climatic versus geochemical controls on soil organic matter stabilization and greenhouse gas emissions along altitudinal transects in different mountain regions

Terrestrial ecosystems are strongly influenced by climate change and soils are key compartments of the globalcarbon (C) cycle in terms of their potential to store or release significant amounts of C. This study is part ofthe interregional IAEA Technical Cooperation Project INT5153 “Assessing the Impact of Climate Change and itsEffects on Soil and Water Resources in Polar and Mountainous Regions” and aims to elucidate driving factors(climatic versus geochemical) of soil organic carbon (SOC) stabilization and greenhouse gas emissions alongaltitudinal transects in different mountain regions.We present novel data from altitudinal transects of four different mountain regions (Zongo, Cordillera Real, Bo-livia; Mount Kilimanjaro, Tanzania; Gongga, Hengduan Mountains, China; Rauris, Hohe Tauern, Austria). Allaltitudinal transects cover a wide range of natural ecosystems under different climatic (MAT, MAP) and soil geo-chemical parameters. Bulk soil samples (four field replicates per ecosystems) were subjected to a combination ofaggregate and particle-size fractionation followed by organic C, total nitrogen (N), stable isotope (13C,15N) andradiocarbon (14C) analyses of all fractions. Bulk soils were further characterized for their texture, geochemistry(Na, K, Ca, Mg, CECpot, Al, Fe, Mn, Si, pH), nutrient status (NH+4, NO−3, Ptot)and incubated for 63 days to assessgreenhouse gas emissions (CO2, CH4, NO, N2O). Moreover, stable C isotope signatures of CO2were determinedto estimate potential sources of soil respiration (using Keeling plots).Cumulative soil CO2emissions (in gCO2-Ckg−1SOC)were highest for the high altitude grassland and forest sitesof Rauris (25.5-25.8) and lowest for the Kilimanjaro forests (4.8-6.9) as well as Bolivian high altitude grasslands(2.5-4.3). Soil CO2emissions were negatively correlated with SOC content (Pearson correlation coefficient rp=-0.35, p=0.002), showing that soils with low SOC contents release the highest amount of CO2per soil C, possiblydue to large fractions of unprotected SOC and thus low SOC stabilization.Particulate organic matter (POM) and sand content were positively correlated with CO2emissions (rp=0.43,p<0.001 and rp=0.57, p<0.001, respectively) and negatively correlated with SOC content (rp=-0.61, p<0.001for sand content), showing that high amounts of POM and/or a sandy soil texture impede SOC storage and supportCO2emissions. In contrast, microaggregates and clay minerals were negatively correlated with CO2emissions(rp=-0.45, p<0.001 and rp=-0.51, p<0.001, respectively) and positively correlated with SOC content (rp=0.84,p<0.001 for clay content), showing their importance for SOC stabilization.Cation exchange capacity (CEC) was positively correlated with SOC content (rp=0.93, p<0.001) and negativelycorrelated with CO2emissions (rp=-0.41, p<0.001). Oppositely, both Si content and the Si/Al ratio were negatively correlated with SOC content (rp=-0.86, p<0.001 and rp=-0.56, p<0.001, respectively) and positively correlatedwith CO2emissions (rp=0.36, p=0.002 and rp=0.34, p=0.003). These relationships point towards an important roleof soil weathering and geochemistry for the potential of soils to store SOC or release CO2.Further results of soil fractionation, greenhouse gas emissions and geochemistry will be presented in conjunctionwith climatic data of the altitudinal transects to elucidate driving factors of SOC (de)stabilization in high altitudemountain regions.ISSN:1029-7006ISSN:1607-796