890 research outputs found
A nonlinear analysis for sloshing forces and moments on a cylindrical tank
Sloshing forces and moments on cylindrical tank - integration of nonlinear force equation
The impact of the EU ETS on the sectoral innovation system for power generation technologies: findings for Germany
This paper provides an overview of early changes in the sectoral innovation system for power generation technologies which have been triggered by the European Emission Trading Scheme (EU ETS). Based on a broad definition of the sector, our research analyses the impact of the EU ETS on the four building blocks knowledge and technologies, actors and networks, institutions and demand by combining two streams of literature, namely systems of innovation and environmental economics. Our analysis is based on 42 exploratory inter-views with German and European experts in the field of the EU ETS, the power sector and technological innovation. We find that the EU ETS mainly affects the rate and direction of the technological change of power generation technologies within the large-scale, coal-based power generation technological regime to which carbon capture technologies are added as a new technological trajectory. While this impact can be interpreted as defensive behaviour of incumbents, the observed changes should not be underestimated. We argue that the EU ETS' impact on corporate CO2 culture and routines may prepare the ground for the transition to a low carbon sectoral innovation system for power generation tech-nologies. --EU emission trading scheme (EU ETS),innovation system,power sector
An approximate nonlinear analysis of the stability of sloshing modes under transla- tional and rotational excitation
Nonlinear analysis of sloshing mode stability under translational and rotational excitatio
Competing periodicities in fractionally filled one-dimensional bands
We present a variable temperature Scanning Tunneling Microscopy and
Spectroscopy (STM and STS) study of the Si(553)-Au atomic chain reconstruction.
This quasi one-dimensional (1D) system undergoes at least two charge density
wave (CDW) transitions at low temperature, which can be attributed to
electronic instabilities in the fractionally-filled 1D bands of the
high-symmetry phase. Upon cooling, Si(553)-Au first undergoes a single-band
Peierls distortion, resulting in period doubling along the imaged chains. This
Peierls state is ultimately overcome by a competing tripleperiod CDW, which in
turn is accompanied by a x2 periodicity in between the chains. These locked-in
periodicities indicate small charge transfer between the nearly half-filled and
quarter-filled 1D bands. The presence and the mobility of atomic scale
dislocations in the x3 CDW state indicates the possibility of manipulating
phase solitons carrying a (spin,charge) of (1/2,+-e/3) or (0,+-2e/3).Comment: submitted, accepted for publication in Phys. Rev. Let
The innovation impact of EU emission trading: findings of company case studies in the German power sector
This paper provides a comprehensive analysis of how the European Emission Trading System (EU ETS) as the core climate policy instrument of the European Union has impacted innovation. Towards this end, we investigate the impact of the EU ETS on research, development, and demonstration (RD&D), adoption, and organizational change. In doing so, we pay particular attention to the rela-tive influences of context factors (policy mix, market factors, public acceptance) as well as firm characteristics (value chain position, technology portfolio, size, vision). Empirically, our analysis is based on multiple case studies with 19 power generators, technology providers, and project developers in the German power sector which we conducted from June 2008 until June 2009. We find that the innovation impact of the EU ETS has remained limited so far because of the scheme’s initial lack in stringency and predictability and the relatively greater importance of context factors. Additionally, the impact varies tremendously across technologies, firms, and innovation dimensions, and is most pronounced for RD&D on carbon capture technologies and corporate procedural change. Our analysis suggests that the EU ETS by itself may not provide sufficient incentives for fundamental changes in corporate climate innovation activities at a level adequate for reaching political long-term targets. Based on the study’s findings, we derive a set of policy and research recommendations. --EU ETS,emission trading,innovation,technological change,adoption,diffusion,organizational change,power sector
Multisensor Data Fusion Implementation for a Sensor Based Fertilizer Application System
"Mapping systems" (“mapping approach”), real-time sensor-actuator systems ("sensor
approach") or the combination of both (“Real-time approach with map overlay”) determine the
process control in mobile application systems for spatially variable fertilization. Within the
integrated research project “Information Systems Precision Farming Duernast” (IKB Duernast)
the implementation of the “Real-time approach with map overlay” was done for intensive
nitrogen fertilization. The bottom line of this sophisticated approach is a comprehensive situation
assessment, a typical multisensor data fusion task. Based on a functional and procedural
modelling of the multisensor data fusion and decision making process, it could be pointed out
that an expert system is an adequate fusion paradigm and algorithm. Therefore, a software
simulation with an expert system as core element was implemented to fuse on-line sensor
technology measurements (REIP), maps (yield, EM38, environmental constraints, draft force)
and user inputs in order to derive an application set point in real-time. The development of an
expert system can be viewed as a structured transformation in five levels from the “specification
level”, the “task level”, the “problem solving level” and the “knowledge base level” to the “tool
level”. In the “tool level” the hybrid expert system shell JESS (Java Expert System Shell) was
selected for implementation due to the results of preceding levels. Knowledge acquisition was
done within another IKB-subproject by the means of data mining. Typical and maximal times of
10 ms and 60 ms for one fusion cycle were measured running this application on a 32-bit
processor hardware (Intel Pentium III Mobile, 1 GHz)
Wavenumber Imaging For Damage Detection and Measurement
This paper presents a method for analyzing ultrasonic wavefield data using the Continuous Wavelet Transform (CWT) applied in the spatial domain. Unlike data obtained by sparse arrays of transducers, full wavefield data contains information local to the structure and can be used to obtain more detailed measurements of damage type, location, size, etc. By calculating the CWT of the wavefield in the spatial domain, the wavenumber spectrum is determined for the inspected locations. Because wavenumber is affected by the local geometry and material properties of the structure through which Lamb waves propagate, the wavenumber spectrum can be analyzed to assess the location, severity, and size of damage. The technique is first applied to experimental wavefield data obtained using a laser Doppler vibrometer and automated positioning stage. The out-of-plane velocity along the length of a composite stringer was measured to detect the presence of delaminations within the composite overwrap. Next, simulated corrosion is detected and measured within an aluminum plate using the two dimensional CWT. The experimental results show the usefulness of the technique for vehicle structure inspection applications
Formation of atom wires on vicinal silicon
The formation of atomic wires via pseudomorphic step-edge decoration on
vicinal silicon surfaces has been analyzed for Ga on the Si(112) surface using
Scanning Tunneling Microscopy and Density Functional Theory calculations. Based
on a chemical potential analysis involving more than thirty candidate
structures and considering various fabrication procedures, it is concluded that
pseudomorphic growth on stepped Si(112), both under equilibrium and
non-equilibrium conditions, must favor formation of Ga zig-zag chains rather
than linear atom chains. The surface is non-metallic and presents quasi-one
dimensional character in the lowest conduction band.Comment: submitte
Gate induced g-factor control and dimensional transition for donors in multi-valley semiconductors
The dependence of the g-factors of semiconductor donors on applied electric
and magnetic fields is of immense importance in spin based quantum computation
and in semiconductor spintronics. The donor g-factor Stark shift is sensitive
to the orientation of the electric and magnetic fields and strongly influenced
by the band-structure and spin-orbit interactions of the host. Using a
multimillion atom tight-binding framework the spin-orbit Stark parameters are
computed for donors in multi-valley semiconductors, silicon and germanium.
Comparison with limited experimental data shows good agreement for a donor in
silicon. Results for gate induced transition from 3D to 2D wave function
confinement show that the corresponding g-factor shift in Si is experimentally
observable.Comment: 4 pages, 4 figure
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