542 research outputs found
Böden marginaler Standorte - Eigenschaften, Limitierungen und Potentiale
Eine zunehmende Knappheit ackerbaulicher Standorte und der zugleich steigende Bedarf an nachwachsenden Rohstoffen für die energetische und stoffliche Nutzung lösen verstärkt Konflikte zwischen der Nahrungsmittelproduktion und der Biomasseproduktion aus. Marginale Standorte kommen entsprechend immer stärker in den Blickpunkt als mögliche Erweiterungsflächen für die Biomasseproduktion. In der wissenschaftlichen Auseinandersetzung fehlt allerdings eine eindeutige Definition für derartige marginale Standorte. Gerade im Hinblick auf eine mögliche Reduzierung von Nutzungskonflikten ist die Abgrenzung zu stillgelegten, aber agrarisch nutzbaren Standorten oder zu natürlichen Badlands, mit naturschutzfachlichen Potentialen oftmals schwierig.
Das EU H2020-Projekt SEEMLA untersucht Potentiale und Verfügbarkeit von marginalen Standorten europaweit. In Deutschland, Griechenland und der Ukraine wurden Pilotstandorte eingerichtet, auf denen der Anbau von Bioenergiepflanzen exemplarisch durchgeführt wird. Für eine erste Bewertung der Standortspotentiale und auch der Ursachen der Marginalität der Standorte wurden Bodenuntersuchungen an allen Pilotstandorten nach den Vorgaben des Muencheberger Soil Quality Rating-Verfahrens (SQR) (1) durchgeführt und die Standorte klassifiziert. Das SQR-Verfahren bewertet ausgewählte Boden- und Standortseigenschaften und bezieht zusätzlich mögliche limitierende Faktoren (Hazard Indicators) wie Versauerung, Versalzung, Vernässung etc. mit ein, um eine Gesamtbewertungszahl zur Bodenfruchtbarkeit zu ermitteln.
Dieser Beitrag stellt anhand der SEEMLA-Standorte exemplarisch Böden marginaler Standorte vor. Mit Hilfe der SQR Hazard Indicators werden charakteristische limitierende Faktoren vorgestellt. Es wird zudem versucht, die untersuchten Standorte in eine mögliche Klassifikation marginaler Standorte einzupassen und ihre Eignung für die Biomasseproduktion einzuschätzen
TINTE - nuclear calculation theory description report
The Time Dependent Neutronics and Temperatures (TINTE) code system deals with the nuclear and the thermal transient behaviour of the primary circuit of the High-temperature Gas-cooled Reactor (HTGR), taking into consideration the mutual feedback effects in twodimensional axisymmetric geometry. This document contains a complete description of the theoretical basis of the TINTE nuclear calculation, including the equations solved, solution methods and the nuclear data used in the solution. This document was prepared in compliance with the layout and review requirements of [1] and [2], and forms part of the verification and validation of TINTE
TINTE - A two-dimensional code for reactor dynamics
The TINTE main documentation consists of three parts, the first two of which/1/,/2/ have been published (in German) in the late eighties. In the first part the problems of modelling the nuclear and thermo-gas-dynamic behaviour of the primary circuit of a high temperature gas cooled reactor (HTGR) have been discussed in detail. It has been explained how the multiconnected system can be decomposed into single tasks to be solved separately. The solution of the total system is thus found by iteration of the partial results. In the second part of the documentation some major applications of TINTE are demonstrated. Among them the analyses of dynamic reactor experiments performed at the AVR reactor /4/ are of special interest. These results play a major role in the TINTE validation process, and the very good conformance obtained with the experimental data validate the TINTE calculations to a considerable extent. Earlier post-calculations of the AVR experiments with a previous version of the TINTE code have been described in /5/. Moreover, the basic algorithms as used in TINTE together with some applications have been shown in /4/. Since not all of the capabilities of TINTE could be addressed in these analysis, the validation process was continued, e.g. with the evaluation of the VELUNA corrosion experiments /6/. An addendum to the principal considerations of /1/ has been added as a supplement to /2/. Here the gas flow in an optional 1-D component and flow network is described, which may be used to enhance the 2-D reactor model for special situations. This flow network was necessary to model non-central pipes and other three-dimensional gas flow paths. It allows the description of co-axial pipes and a lumped parameter simulation of the primary side ofheat exchangers or steam generators. One example in /4/ shows that under certain limitations even a simulation of a gas-gas heat exchanger and the incorporation of the secondary loop is possible with the aid of that flow-network. In this addendum the possibility is also introduced to calculate the pressure inside the reactorfrom a given (fixed or variable in time) gas inventory. This is of relevance for accident analyses, where a failure of the pressure enclosure is assumed. If the pressure increases significantly gas may be removed from the system by burst discs or safety valves. This document starts with a description of the TINTE code structure (Section 4), while Section 5 is dedicated to the description and interpretation of the main input data. Section 6 deals with the preparation of the nuclear data base, the generation of the cross-section polynomial expansions and the necessary interface codes. Aspects included here are the evaluation of nuclide vectors (prepared by burn-up codes) and the preparation of spectrum calculations with variation of temperatures, buckling and concentrations for spectrum relevant nuclides. User notes on the code installation and calculational procedures are presented in Section 7, while Sections 8 and 9 discuss the TINTE control options and output data options, respectively. Section 10 lists the changes made in the TINTE source code over the years. The report also includes in the Appendices some newer algorithms for the treatment of special situations, while a description of the correlations used for the heat capacities and thermal conductivities are also given. Of special note here is Appendix E, which lists the detail of the ROMO model newly implemented in TINTE in 2004
Electron on solid neon -- a new solid-state single-electron qubit platform
The promise of quantum computing has driven a persistent quest for new qubit
platforms with long coherence, fast operation, and large scalability.
Electrons, ubiquitous elementary particles of nonzero charge, spin, and mass,
have commonly been perceived as paradigmatic local quantum information
carriers. Despite superior controllability and configurability, their practical
performance as qubits via either motional or spin states depends critically on
their material environment. Here we report our experimental realization of a
new qubit platform based upon isolated single electrons trapped on an
ultraclean solid neon surface in vacuum. By integrating an electron trap in a
circuit quantum electrodynamics architecture, we achieve strong coupling
between the motional states of a single electron and microwave photons in an
on-chip superconducting resonator. Qubit gate operations and dispersive readout
are used to measure the energy relaxation time of s and phase
coherence time over 200 ns, indicating that the electron-on-solid-neon
qubit already performs near the state of the art as a charge qubit.Comment: 7 pages, 3 figure
Identification of the estrogen receptor beta as a possible new tamoxifen-sensitive target in diffuse large B-cell lymphoma
Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype. Despite the proven efficacy of combined immunochemotherapy (R-CHOP) in the majority of patients, ~40% of DLBCL patients do not respond or will relapse and consequently have a very poor prognosis. The development of targeted therapies has not improved patient survival, underscoring the need for new treatment approaches. Using an unbiased genome-wide CD20 guilt-by-association approach in more than 1800 DLBCL patients, we previously identified the estrogen receptor beta (ERβ) as a new target in DLBCL. Here, we demonstrate that ERβ is expressed at significantly higher levels in DLBCL compared to normal B cells, and ERβ plays a role in the protection against apoptosis in DLBCL. Targeting of the ERβ with the selective estrogen receptor modulator tamoxifen reduces cell viability in all tested DLBCL cell lines. Tamoxifen-induced cell death was significantly decreased in an ERβ knock-out cell line. The activity of tamoxifen was confirmed in a xenograft human lymphoma model, as tumor growth decreased, and survival significantly improved. Finally, tamoxifen-treated breast cancer (BC) patients showed a significantly reduced risk of 38% for DLBCL compared to BC patients who did not receive tamoxifen. Our findings provide a rationale to investigate tamoxifen, a hormonal drug with a good safety profile, in DLBCL patients
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Next-generation magnetic nozzle prototype
This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to develop a next-generation magnetic nozzle. The project engaged the fundamental physics of plasma- magnetic field interactions to attain plasma accelerator control that is significantly more advanced than the present state-of-the-art. Central to next-generation magnetic nozzle design and development is the ability to precisely predict the interaction of flowing magnetized plasma with self-generated and applied magnetic fields. This predictive capability must order physical processes in a way that preserves accuracy while allowing for the rapid evaluation of many different nozzle configurations. Large, ``off-the-shelf``, numerical codes are not well suited to nozzle design applications in that they lack the necessary non-ideal physics and are not well disposed to rapid design evaluation. For example, we know that both non-ideal magnetohydrodynamic effects, such as Hall drifts and finite ion- gyro-radius kinetics, are important constituents of magnetic nozzle performance. We built a special purpose code to allow system design
Compression of Interstellar Clouds in Spiral Density-Wave Shocks
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Metagenomic Characterization of the Human Intestinal Microbiota in Fecal Samples from STEC-Infected Patients
The human intestinal microbiota is a homeostatic ecosystem with a remarkable impact on human health and the disruption of this equilibrium leads to an increased susceptibility to infection by numerous pathogens. In this study, we used shotgun metagenomic sequencing and two different bioinformatic approaches, based on mapping of the reads onto databases and on the reconstruction of putative draft genomes, to investigate possible changes in the composition of the intestinal microbiota in samples from patients with Shiga Toxin-producing E. coli (STEC) infection compared to healthy and healed controls, collected during an outbreak caused by a STEC O26:H11 infection. Both the bioinformatic procedures used, produced similar result with a good resolution of the taxonomic profiles of the specimens. The stool samples collected from the STEC infected patients showed a lower abundance of the members of Bifidobacteriales and Clostridiales orders in comparison to controls where those microorganisms predominated. These differences seemed to correlate with the STEC infection although a flexion in the relative abundance of the Bifidobacterium genus, part of the Bifidobacteriales order, was observed also in samples from Crohn's disease patients, displaying a STEC-unrelated dysbiosis. The metagenomics also allowed to identify in the STEC positive samples, all the virulence traits present in the genomes of the STEC O26 that caused the outbreak as assessed through isolation of the epidemic strain and whole genome sequencing. The results shown represent a first evidence of the changes occurring in the intestinal microbiota of children in the course of STEC infection and indicate that metagenomics may be a promising tool for the culture-independent clinical diagnosis of the infection
Assessment and quantification of marginal lands for biomass production in Europe using soil-quality indicators
The cultivation of bioenergy plants in fertile, arable lands
increasingly results in new land use conflicts with food production and cannot be
considered as sustainable. Marginal lands have been frequently considered as potential
alternatives for producing bioenergy from biomass. However, clear definitions and
assessment methods for selecting marginal lands and for calculating potentials are still
widely missing.
The project “SEEMLA” aims at triggering the exploitation of currently underused
marginal lands for biomass production for energy purposes. Study sites have been selected
in different European countries: Germany, Greece, and Ukraine. The selected sites
represent a wide variety of different types of marginal lands. Based on a soil assessment
set given by the Muencheberg Soil Quality Rating (SQR) system potentially “marginal”
sites have been investigated. The SQR system allows for clearly distinguishing between
soils of higher and lower quality. Soils with SQR scores below 40 are regarded as
“marginal”. They can be classified into different groups with regard to the importance
of soil hazard indicators as evaluated by the SQR approach. The calculated SQR scores
correlate significantly with biomass yields of bioenergy plants.
Further, the SQR method was adapted for use in a GIS study on marginal-land potentials in
Europe. Thus, 46 % of the investigated European area could be classified as
“marginal” with SQR scores below 40. From that area 22.6 % can be considered as
potentially suitable for producing renewable resources after eliminating protected sites
or other places not suitable for any kind of land use. Taking the ecological demands of
selected bioenergy plants into account it is possible to give first preliminary
recommendations for regional crop cultivation.
It can be concluded that Europe offers a large potential for renewable resources from
marginal sites. However, the implementation into practice is often impeded by missing or
varying policies and regulations. A proper implementation needs clear regulations and
also incentives for farmers at the European level.</p
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