Monitoring water-chemistry evolution in the bentonite buffer using magnets: Effects of corrosion on buffer stability

Bentonite has been chosen as a buffer material by several national nuclear-waste management companies because of its swelling capacity and low water permeability, and because it retards the transport of radionuclides and corrosion products toward the geosphere. The aim of the present study was to develop a magnetic material that has the ability to detect changes in groundwater compositions in an underground nucleardeposit facility through variation in its magnetic properties with time. The present study has investigated the effect of the corrosion of NdFeB magnets on the Na-bentonite buffer under different environmental conditions. Seven different aqueous solutions were used for long-time exposure tests (708C, 5 months) with fragments of NdFeB magnets and powdered Na-bentonite. The corrosion of NdFeB alloy had no detectable effect on the mineralogy of the clay minerals, and any change on the bentonite matrix, measured through X-ray diffraction analysis, was related to the different initial chemistry of the solutions.© 2016 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/)

Black carbon contributes to organic matter in young soils in the Morteratsch proglacial area (Switzerland)

Most glacier forefields of the European Alps are being progressively exposed since the glaciers reached their maximum expansion in the 1850s. Global warming and climate changes additionally promote the exposure of sediments in previously glaciated areas. In these proglacial areas, initial soils have started to develop so that they may offer a continuous chronosequence from 0 to 150-yr-old soils. The build-up of organic matter is an important factor of soil formation, and not only autochthonous but also distant sources might contribute to its accumulation in young soils and surfaces of glacier forefields. Only little is known about black carbon in soils that develop in glacier forefields, although charred organic matter could be an important component of organic carbon in Alpine soils. The aim of our study was to examine whether black carbon (BC) is present in the initial soils of a proglacial area, and to estimate its relative contribution to soil organic matter. We investigated soil samples from 35 sites distributed over the whole proglacial area of Morteratsch (Upper Engadine, Switzerland), covering a chronosequence from 0 to 150 yr. BC concentrations were determined in fine earth using the benzene polycarboxylic acid (BPCA) marker method. We found that charred organic matter occurred in the whole area, and that it was a main compound of soil organic matter in the youngest soils, where total Corg concentrations were very low. The absolute concentrations of BC in fine earth were generally low but increased in soils that had been exposed for more than 40 yr. Specific initial microbial communities may profit from this additional C source during the first years of soil evolution and potentially promote soil development in its early stage

Le api svelano il mistero delle fonti di emissione di particolato inquinante

Si tratta di una ricerca che è durata due anni, ed è stata pubblicata sul numero di luglio 2015 della Rivista scientifica internazionale Plos One. Gli autori: Ilaria Negri, Marco Pellecchia (Koiné - Consulenze Ambientali S.n.c., Parma, Italy), Christian Mavris (Department of Earth Sciences, Natural History Museum, London, United Kingdom), Gennaro Di Prisco, Emilio Caprio (Dipartimento di Agraria, Laboratorio di Entomologia E. Tremblay, Università degli Studi di Napoli Federico II, Portici - Napoli). Nello studio scientifico i ricercatori dimostrano che le api si comportano anche come “campionatori” attivi di particolato atmosferico, i cosiddetti PM (dall’inglese “Particulate Matter”), di cui sono ricche le nostre città come troppo spesso avvertono i dati dell’Agenzia Regionale di Protezione dell’Ambiente (ARPA). Dice che l’Iglesiente (Iglesias, Sardegna) è inquinato, fortemente contaminato da metalli pesanti come il piombo e il bario. E svela poi che la salute di chi ci vive potrebbe essere compromessa, se non lo è già, anche dall’alta concentrazione di ferro, silicio e alluminio. Rivela ancora, con scientifica precisione, da dove provengono le micro particelle di queste impercettibilissime polveri: dalle miniere dell’Iglesiente e dalle industrie di Portovesm

Honey Bees (Apis mellifera, L.) as Active Samplers of Airborne Particulate Matter

© 2015 Negri et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. [CC by 4.0] The attached file is the published version of the article

System Level Trade Study of Hybrid Parallel Propulsion Architectures on Future Regional and Thin Haul Turboprop Aircraft

Presented at the AIAA SCITECH 2023 ForumThis paper evaluates the potential benefits of applying hybrid parallel propulsion architectures to future turboprop aircraft that are expected to enter into service in 2030. Two baseline aircraft models are established by infusing viable 2030 airframe and engine technologies on state-of-the-art 19-passenger and 50-passenger aircraft models. Two parametric parallel hybrid architectures are proposed and applied on both size classes: Architecture 1 has two propellers, each driven by an engine and an electric motor in parallel, and allows in-flight recharging; Architecture 2 has four propellers, each driven by either an engine or an electric motor, and allows parallel operation during the cruise. A design space exploration is conducted on the powertrain design variables and the electric component key performance parameters. A constrained optimization implies that Architecture 1 and 2 can achieve fuel savings of about 2.6% and 6.6%, respectively, given 2030 electric component technology assumptions. Electric taxi consistently results in fuel saving when battery technology is beyond the projected 2030 level. Preliminary sensitivity studies show that the performance of Architecture 2 is more sensitive to the battery technology compared to Architecture 1 due to its extensive use of battery energy during the cruise.NATIONAL INSTITUTE OF AEROSPACE, GR0001018

Characterization of the Promoter, MxiE Box and 5′ UTR of Genes Controlled by the Activity of the Type III Secretion Apparatus in Shigella flexneri

Activation of the type III secretion apparatus (T3SA) of Shigella flexneri, upon contact of the bacteria with host cells, and its deregulation, as in ipaB mutants, specifically increases transcription of a set of effector-encoding genes controlled by MxiE, an activator of the AraC family, and IpgC, the chaperone of the IpaB and IpaC translocators. Thirteen genes carried by the virulence plasmid (ospB, ospC1, ospD2, ospD3, ospE1, ospE2, ospF, ospG, virA, ipaH1.4, ipaH4.5, ipaH7.8 and ipaH9.8) and five genes carried by the chromosome (ipaHa-e) are regulated by the T3SA activity. A conserved 17-bp MxiE box is present 5′ of most of these genes. To characterize the promoter activity of these MxiE box-containing regions, similar ∼67-bp DNA fragments encompassing the MxiE box of 14 MxiE-regulated genes were cloned 5′ of lacZ in a promoter probe plasmid; β-galactosidase activity detected in wild-type and ipaB strains harboring these plasmids indicated that most MxiE box-carrying regions contain a promoter regulated by the T3SA activity and that the relative strengths of these promoters cover an eight-fold range. The various MxiE boxes exhibiting up to three differences as compared to the MxiE box consensus sequence were introduced into the ipaH9.8 promoter without affecting its activity, suggesting that they are equally efficient in promoter activation. In contrast, all nucleotides conserved among MxiE boxes were found to be involved in MxiE-dependent promoter activity. In addition, we present evidence that the 5′ UTRs of four MxiE-regulated genes enhance expression of the downstream gene, presumably by preventing degradation of the mRNA, and the 5′ UTRs of two other genes carry an ancillary promoter

Zero-Emission Regional Aviation in Sweden

Presented at the 33rd ICAS Congress, Sweden (2022).Regional air operations, which can be defined as the transportation of passengers using smaller aircraft over short distances, have been overlooked in recent years by airlines focusing on high volume and profitable routes between large airports. Despite this shift of focus, the airport infrastructure still exists in many smaller communities between which demand for air travel exists. The emergence of new air vehicles designed for shorter routes could stimulate efficient and profitable operations, especially if they leverage currently underutilized and paid-for airports. However, new regional air operations need to be sustainable to be successful in a world striving for a carbon-neutral future, especially since air travel over short distances can be substituted by other means of transportation with a smaller environmental footprint such as cars, trains, or buses. Many different paths are envisioned to reach zero-emission goals. These range from technology advancements to new powertrain configurations, and from new transportation policies to new emission offsetting schemes. It is however not clear how these different paths interact and how solutions could be optimally combined. Analyses are therefore required to estimate future demand for air travel and to assess the feasibility of zero-emission regional aviation with the objective to support decision-making about viable and sustainable paths for new regional air operations. The developed modeling environment is implemented in Sweden and allows for an environmental assessment of various scenarios. Significant untapped demand is uncovered between smaller markets, and given fuel and energy consumption for these operations, it is likely that sustainable advanced regional air mobility will be possible in Sweden provided technology transitions can be made

Performance Assessment of a Distributed Electric Propulsion System for a Medium Altitude Long Endurance Unmanned Aerial Vehicle

Presented at 2021 Electric Aircraft and Technology SymposiumDistributed propulsion systems are enabled by electrified aircraft and can provide aero-propulsive benefits. The magnitude and impact of these benefits rely on the location of propulsors on the vehicle, the amount of propulsive force generated by those propulsors, vehicle geometry, and the extent of hybridization of the propulsion system. With an increased number of degrees of freedom over conventionally electrified aircraft, the full extent of the impacts of this technology have not yet been explored, especially for military applications. This study builds on a previous one that implemented a series hybrid and turboeletric propulsion architecture on a turboprop UAV, by introducing a distributed electric propulsion system on the same vehicle. The previous study showed that with a hybrid architecture, the same performance, in terms of range and endurance, could not be achieved for a fixed gross take-off weight. This study investigates the impact of the distributed propulsion system with the goal of identifying the benefits over the previous vehicle and determining the level of technology required to break even with the conventional propulsion UAV. In incorporating the new propulsion system, the engine and main motor are resized, leading edge wing mounted propellers and motors are added to the configuration, and a new battery sizing strategy is implemented. Preliminary results show that, although this new system shows increased range and endurance over the series hybrid vehicle, it still falls short compared to the conventional vehicle with current levels of technology. Although improvements are needed to the electrical system technology to reduce the weight enough to break even with the conventional system, the new vehicle shows increased performance during climb, and has the capability to store energy during the mission. With the proper power management and battery utilization strategies, this system can provide reduction in fuel burn and improved performance during certain phases of the mission which could be beneficial for military applications.Air Force Research Laborator

Modeling and Simulation of Novel Electric/Hybrid Electric Multicopter Architectures for Urban Air Mobility

Presented at AIAA Propulsion and Energy Forum, August 9-11, 2021, VIRTUAL EVENTThis paper introduces a dynamic simulation environment developed for novel multi-copter aircraft architectures. The development is motivated by the need to better understand the safety implications of architectural design choices and to provide a formal reliability assessment framework for new Vertical Take-Off and Landing (VTOL) concepts able to consider various airframe and subsystems dynamic behavior. The concepts of interests are different multi-copters configurations investigated by NASA and featuring either electric, hybrid electric, or turboshaft driven powertrains. The simulation environment is a timemarching dynamic simulator formulated using physics-based subsystem models for the batteries, electric motors, turboshaft engines and electric generators. Identified fault modes are integrated into the subsystem models for subsequent use during reliability assessments. The impacts of subsystem faults are propagated to the vehicle flight dynamic response for analysis of their impact on the ability of the vehicle to sustain safe operations. Detailed features of the electric quadrotor model are provided to illustrate the simulation capabilities. Some faults are inserted on the different aircraft in hover and the subsystems behavior is successfully propagated at the vehicle level