623 research outputs found
Ökologische Bewertung von Transportprozessen: Systematisierung und Analyse existierender Bewertungsverfahren und Studien
Die vorliegende Ausgabe beschäftigt sich mit der ökologischen Bewertung von Transportprozessen. Aus der Tatsache einer sich stets verstärkenden Überlastung des europäischen Verkehrsnetzes und der damit verbunden steigenden externen Kosten der Verkehrsüberlastung ergibt sich die Handlungsnotwendigkeit hinsichtlich einer Umgestaltung des europäischen Verkehrssystems. Neben den externen Kosten, die durch Staus oder Unfälle verursacht werden, entstehen der Volkswirtschaft zudem Kosten durch Umwelteinwirkungen des Verkehrs, wie Lärm- oder Schadstoffemissionen sowie Flächen-verbrauch beziehungsweise Flächenversiegelung. Vor dem Hintergrund der Überlastung der Verkehrsträger und der Umweltbelastungen gibt es in der Europäischen Union Bestrebungen nach einer Optimierung des Verkehrssystems, welches wirtschaftlichen, ökologischen und sozialen Ansprüchen dauerhaft genügen soll. Aus dieser Zielstellung leitete sich auch die Problemstellung für die vorliegende Arbeit ab. Um eine Optimierung des Verkehrssystems zu erreichen, ist es zunächst wichtig, Transportprozesse hinsichtlich der drei Dimensionen der Nachhaltigkeit Wirtschaft, Ökologie und Soziales zu bewerten. Spezifiziert wurde die Arbeit dabei auf die Bewertung von Transportketten des Güterverkehrs hinsichtlich ökologischer und ökonomischer Gesichtspunkte und die Umsetzung in der Praxis einerseits im Rahmen von Fallstudien und andererseits in EDV-gestützten Bewertungstools. Hierzu wurde zunächst ein integrierter Bewertungsansatz aus den drei Dimensionen der Nachhaltigen Ent-wicklung abgeleitet. Auf der Grundlage dieses Bewertungsansatzes sind anschließend Fallstudien sowie Bewertungstools beziehungsweise Softwaretools zur Transportbewertung analysiert und systematisiert worden. Die Analyse sollte zeigen, inwieweit eine Bewertung von Transportprozessen nach nachhaltigen Gesichtspunkten in der Praxis in Form von Fallbeispielen sowie der Bewertungsmethodik von EDV-gestützten Berechnungsinstrumenten dem Idealmodell gerecht wird
An Emission-free Modular Vehicle Concept for Inner Urban Transportation in Near Future Megacities (Urban MoVe-T)
As the demands for fast and sustainable transportation in megacities are growing, new transportation concepts with full electric vehicles for the distribution of goods are needed. Not only the “last mile” is important for the delivery of small goods, but also the distribution from the big logistic centres in the outskirts to the inner city has a big influence on the volume of traffic. A new concept for a zero emission vehicle, the “Urban MoVe-T” (Urban Modular Vehicle for Transportation) has been developed within the Institute of Vehicle Concepts to meet these new requirements It consists of two parts, the “Ultra Mobility Tractor” (UMT) and secondly different “Intelligent Versatile Modules” (IVM). The concept of the one-axle-two-wheeled UMT is comparable to the well-known Segway© technology, but includes an additional driver cabin and an integrated safety cell for the driver. Moreover the UMT has an innovative wheel integrated bearing and chassis suspension system. This suspension system includes an innovative electric motor coupling, which enables to keep the unsprung masses low, while providing the unit compact. With the vehicle`s tractor module the driver has a high manoeuvrability, which is important, when used for delivery in historic city centres like Vienna. Coupled with the smallest Intelligent Versatile Module, the whole transportation vehicle has a total length of 2.5m and width of 1.7m, but is capable to carry two euro-pallets with a payload of 1t each. The vehicle has the highest payload per vehicle volume rate up to date. Due to its compact dimensions it enables the new concept to be integrated in existing infrastructures like into the commuter railway system. It can be parked transverse to the direction of travel of the train and can later on leave the train without changing the direction itself. The IVMs used for carrying the load all have 360° turn able wheels for manoeuvring on the spot to meet the requirements for the usage with the UMT. As all the IVMs have their own electric drive system, the load modules are able to drive independently when used on restricted sites like in distribution centres in the outskirts of the megacities. A bigger version of the IVM is able to carry six euro-pallets and has the dimensions of 3.5m length and 2.5m width; in total the tractor/load module combination has a total length as well as a turning radius of less than 5m, which is an unchallenged value for a vehicle in the sector of transportation. The big IVMs are also capable to be put autonomous onto the train for a fast and effective transportation from the distribution centre into the city centre. There the UMTs could fetch the IVMs and bring them to their destination. So a whole new effective distribution can be achieved with a significant reduction of the overall traffic on the streets of the big cities
Tunneling resonances in quantum dots: Coulomb interaction modifies the width
Single-electron tunneling through a zero-dimensional state in an asymmetric
double-barrier resonant-tunneling structure is studied. The broadening of steps
in the -- characteristics is found to strongly depend on the polarity of
the applied bias voltage. Based on a qualitative picture for the
finite-life-time broadening of the quantum dot states and a quantitative
comparison of the experimental data with a non-equilibrium transport theory, we
identify this polarity dependence as a clear signature of Coulomb interaction.Comment: 4 pages, 4 figure
Influencing factors of the digital transformation on the supply chain complexity dimensions
Digital Disruption - 'the world in which we live in is changing'! Next-day delivery, Click & Collect, personalization, short delivery times and full order transparency have been incorporated in our daily life. In order to stay competitive, companies must react to the shifting customer demand towards on-demand, fitfor- purpose services and other market requirements. Due to these challenges and the increasing globalization, companies are confronted with ever more complex supply chain networks. The way to deal with the strongly increasing complexity of the company itself and its environment has become a key competitive factor. The complexity within a production company is characterized by the challenges encountered in daily business processes and can be described by the four dimensions of complexity: variety, heterogeneity, dynamics and non- transparency, as well as their interrelationships. Therefore, Supply Chain Management (SCM) is evolving from simply managing a chain of suppliers and manufactures towards a complex network including complicated backflows. New approaches in the context of digital transformation promise to support the management of such complex supply networks. Within this paper, influencing factors of the digital transformation and their effect on the four complexity dimensions are presented
Hochgeschwindigleitszüge - Zug der Zukunft
Wie können wir den Bahnverkehr noch sicherer, effizienter und umweltfreundlicher gestalten ? Wie müssen die Züge von Morgen beschaffen sein? Diesen Fragen gehen die Schienverkehrsforscher beim DLR nach. Im Projekt 'Next Generation Train' arbeiten DLR-Wissenschaftler daran, Hochgeschwindigkeits-Züge der nächsten Generation schnell, sicher, komfortabel und umwerltverträglich zu machen
Massive and low-mass protostars in massive "starless" cores
The infrared dark clouds (IRDCs) G11.110.12 and G28.340.06 are two of
the best-studied IRDCs in our Galaxy. These two clouds host clumps at different
stages of evolution, including a massive dense clump in both clouds that is
dark even at 70 and 100m. Such seemingly quiescent massive dense clumps
have been speculated to harbor cores that are precursors of high-mass stars and
clusters. We observed these two "prestellar" regions at 1mm with the
Submillimeter Array (SMA) with the aim of characterizing the nature of such
cores. We show that the clumps fragment into several low- to high-mass cores
within the filamentary structure of the enveloping cloud. However, while the
overall physical properties of the clump may indicate a starless phase, we find
that both regions host multiple outflows. The most massive core though 70
m dark in both clumps is clearly associated with compact outflows. Such
low-luminosity, massive cores are potentially the earliest stage in the
evolution of a massive protostar. We also identify several outflow features
distributed in the large environment around the most massive core. We infer
that these outflows are being powered by young, low-mass protostars whose core
mass is below our detection limit. These findings suggest that low-mass
protostars have already formed or are coevally formed at the earliest phase of
high-mass star formation.Comment: in print at A&
Synthesis and Characterization of Naphtho[2,1‐b:7,8‐b′]bis[1]benzothiophene
We describe a simple three‐step synthesis of naphtho[2,1‐b:7,8‐b′]bis[1]benzothiophene, which is scalable to multi‐hundred‐gram. We report the subsequent functionalization of this compound into iodine, boronic ester and silane derivatives, which are useful intermediates for various applications. The core structure was analyzed by NMR and single‐crystal X‐ray diffraction, and the physical properties were investigated by cyclic voltammetry, UV/Vis‐ and fluorescence spectroscopy
Akzeptanz des unverpackt-Angebotes in Bio-Supermärkten: Zwei Kundenbefragungen
Angesichts des steigenden Verpackungsmüllaufkommens und der zunehmenden Umweltverschmutzung durch Plastik ist ein Trend zu unverpackten Lebensmitteln und Zero-Waste-Produkten in Deutschland erkennbar. Nicht nur spezialisierte unverpackt-Läden, sondern auch Bio-Supermärkte bieten inzwischen lose und unverpackte Ware an. Eine explorative Kundenbefragung analysiert die Akzeptanz, Nutzung und Bewertung von unverpackt-Abteilungen in zwei Filialen zweier Biosupermarktketten in Berlin. Ziel ist es zu untersuchen, ob, wie und aus welchen Gründen Kunden unverpackt angebotene Ware kaufen und welche Herausforderungen sich aus dieser Form des Einkaufens ergeben. Die Ergebnisse legen nahe, dass Transparenz, mehr Information und Kommunikation des Konzept am "point of sale" sowie Maßnahmen zur Erhöhung der Alltagskompatibilität zu einer verstärkten Nutzung des unverpackt-Angebots beitragen können
Identification of poly(ADP-ribose)polymerase-1 and Ku70/Ku80 as transcriptional regulators of S100A9 gene expression
BACKGROUND: S100 proteins, a multigenic family of non-ubiquitous cytoplasmic Ca(2+)-binding proteins, have been linked to human pathologies in recent years. Dysregulated expression of S100 proteins, including S100A9, has been reported in the epidermis as a response to stress and in association with neoplastic disorders. Recently, we characterized a regulatory element within the S100A9 promotor, referred to as MRE that drives the S100A9 gene expression in a cell type-specific, activation- and differentiation-dependent manner (Kerkhoff et al. (2002) J. Biol. Chem. 277, 41879–41887). RESULTS: In the present study, we investigated transcription factors that bind to MRE. Using the MRE motif for a pull-down assay, poly(ADP-ribose)polymerase-1 (PARP-1) and the heterodimeric complex Ku70/Ku80 were identified by mass spectrometry and confirmed by chromatin immunoprecipitation. Furthermore, TPA-induced S100A9 gene expression in HaCaT keratinocytes was blocked after the pharmacologic inhibition of PARP-1 with 1,5-isoquinolinediol (DiQ). CONCLUSION: The candidates, poly(ADP-ribose)polymerase-1 (PARP-1) and the heterodimeric complex Ku70/Ku80, are known to participate in inflammatory disorders as well as tumorgenesis. The latter may indicate a possible link between S100 and inflammation-associated cancer
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