140 research outputs found
Renewable energy sources to secure the base load in electricity supply. Summary
The share of renewable energies in Germany\u27s electricity supply has been increasing at an impressive rate in recent years: it already amounts to over 20 %, about half of which comes from fluctuating sources - mainly wind power and photovoltaics. In the long term (by 2050), the goal is to achieve almost full supply with renewable energies. This makes it clear that the system of electricity supply will be subject to an upheaval of historic proportions in the coming decades.
The TAB report addresses the question of how the base load in the electricity supply can continue to be secured under these conditions. This question can only be addressed in a system perspective that encompasses all levels: from generation to transport and distribution to the consumption of electricity. Therefore, the question expands to how a secure supply can be organised as a whole.
It is becoming apparent that the electricity system must be able to react much more flexibly than before to different feed-in and demand situations.
Options for increasing flexibility exist in many areas:
> Increasing the efficiency of the grids
> Increasing the flexibility of the conventional power plant fleet and its mode of operation
> Greater orientation of electricity production from renewable energies to demand
> load management, and not least the construction of additional storage facilities.
In all of these fields of action, the TAB report identifies options for action in which the public sector and the energy policy actors in the executive and legislative branches can contribute to the success of the upcoming transformation of the electricity supply by shaping the framework conditions
Sensitivity Analysis of Electrocardiogram Features to Computational Model Input Parameters
Cardiac models of electrophysiology capable of generating simulated electrocardiogram (ECG) signals are an increasingly valuable tool for both personalised medicine and understanding cardiac pathologies. Sensitivity analysis (SA) can provide crucial insight into how simulation parameters affect ECG morphology. We use two SA methods, direct numerical evaluation of integrals and polynomial chaos expansion, to calculate main and total effects for ECG features extracted from QRS complexes generated by a cardiac ventricular model. The importance of stimulation site parameters on output ECG features is evaluated. SA methods can highlight and quantify important input parameters for different ECG morphology features, which in some cases can be linked to physiological explanations. For example R peak amplitude in lead II depends on apicobasal location of stimulation sites in the left ventricle. Furthermore, different SA methods have different strengths and weaknesses. Insight into parameter importance supports model development and allows for more nuanced and patient-specific simulation changes
Regenerative EnergietrÀger zur Sicherung der Grundlast in der Stromversorgung. Endbericht zum Monitoring
Der Anteil erneuerbarer Energien an der Stromversorgung Deutschlands steigt in den letzten Jahren mit beeindruckender Geschwindigkeit: er betrĂ€gt bereits ĂŒber 20 %, davon etwa die HĂ€lfte aus fluktuierenden Quellen â vor allem Windkraft und Photovoltaik. Langfristig (bis 2050) wird die Zielsetzung einer nahezu Vollversorgung mit erneuerbaren Energien verfolgt. Damit wird deutlich, dass das System der Stromversorgung in den nĂ€chsten Jahrzehnten einem Umbruch historischen AusmaĂes unterliegen wird.
Der TAB-Bericht geht der Frage nach, wie unter diesen Bedingungen die Grundlast in der Stromversorgung weiterhin gesichert werden kann. Diese Frage kann nur in einer Systemperspektive angegangen werden, die alle Ebenen umfasst: von der Erzeugung ĂŒber den Transport und die Verteilung bis hin zum Verbrauch von ElektrizitĂ€t. Daher erweitert sich die Fragestellung dahingehend, wie eine gesicherte Versorgung insgesamt organisiert werden kann.
Es zeigt sich, dass das Stromsystem wesentlich flexibler als bisher auf unterschiedliche Einspeise- und Nachfragesituationen reagieren können muss.
Optionen zur Steigerung der FlexibilitÀt existieren in vielen Bereichen:
> Erhöhung der LeistungsfÀhigkeit der Netze
> Flexibilisierung des konventionellen Kraftwerksparks und dessen Betriebsweise
> stÀrkere Orientierung der Stromproduktion aus erneuerbaren Energien an der Nachfrage
> Lastmanagement, sowie nicht zuletzt Errichtung von zusÀtzlichen Speichern
In allen diesen Handlungsfeldern werden im TAB-Bericht Handlungsoptionen identifiziert, wie die öffentliche Hand bzw. die energiepolitischen Akteure in Exekutive und Legislative durch Gestaltung von Rahmenbedingungen dazu beitragen können, dass der anstehende Umbau der Stromversorgung gelingen kann.
INHALT
ZUSAMMENFASSUNG 5
I. EINLEITUNG 19
II. ELEKTRIZITĂTSVERSORGUNG IN DEUTSCHLAND 23
1. Ausbauziele und Szenarien fĂŒr RES-E 25
2. Grundlast und gesicherte Versorgung 29
III. STROMNETZE 39
1. Erweiterung der NetzkapazitÀt 39
1.1 Optimierung des Netzbetriebs 39
1.2 Massnahmen zur NetzverstÀrkung 40
1.3 Netzausbau 42
2. Netzausbaubedarf und Kosten 44
2.1 Deutschland 45
2.2 EuropÀische Perspektive 54
2.3 TranseuropÀisches Supergrid 56
IV. SPEICHER UND WEITERE FLEXIBILISIERUNGSOPTIONEN 63
1. Speicher 64
1.1 Speicherbedarf 66
1.2 Speicherkosten 68
1.3 Speichertechnologien 70
2. Weitere Flexibilisierungsoptionen 83
2.1 Biogas 83
2.2 WĂ€rme als Stromsenke â Verbindung zum WĂ€rmesektor 86
2.3 Lastmanagement 88
2.4 Ausbau des Stromaustausches mit Norwegen 92
2.5 Regenerative Kombi-/Hybridkraftwerke 94
3. Speicher und weitere Flexibilisierungsoptionen: Zwischenfazit 97
V. SZENARIENANALYSE 99
1. Vorgehensweise 99
2. Bestimmung der Einspeiseprofile im Referenzjahr 100
3. Szenariodarstellung 101
4. Situation des Stromversorgungsystems ohne
Flexibilisierungsoptionen 103
5. Begrenzungen und Flexibilisierungsoptionen 106
5.1 Systemdienstleistungen 107
5.2 Bestehende Flexibilisierungsoptionen 108
5.3 Geplanter Ausbau der bestehenden
Flexibiliersungsoptionen bis 2020 109
6. Parametrisierung der Flexibilisierungsoptionen 111
6.1 Beschreibung des Modellierungsansatzes 112
6.2 Ergebnisse zur GlÀttung der Residuallast 113
6.3 Ergebnisse zur GlÀttung der RES-E-Einspeisung 115
6.4 NetzengpÀsse als weitere Begrenzung 118
7. Kernergebnisse der Analyse 118
VI. INTERNATIONALE ERFAHRUNGEN 121
1. DĂ€nemark 122
2. Iberische Halbinsel 124
3. Vergleich mit Deutschland 125
VII. HANDLUNGSFELDER UND HANDLUNGSOPTIONEN 129
1. NetzengpÀsse und Netzausbau 129
2. Konventionelle Kraftwerke 131
3. Flexibilisierungsoptionen 133
4. Regelmarkt 137
5. Strommarktdesign 138
6. EuropÀische Kooperation 138
VIII. LITERATUR 139
1. In Auftrag gegebene Gutachten 139
2. Weitere Literatur 139
IX. ANHANG 153
1. Tabellenverzeichnis 153
2. Abbildungsverzeichnis 15
A New H I Survey of Active Galaxies
We have conducted a new Arecibo survey for H I emission for 113 galaxies with
broad-line (type 1) active galactic nuclei (AGNs) out to recession velocities
as high as 35,000 km/s. The primary aim of the study is to obtain sensitive H I
spectra for a well-defined, uniformly selected sample of active galaxies that
have estimates of their black hole masses in order to investigate correlations
between H I properties and the characteristics of the AGNs. H I emission was
detected in 66 out of the 101 (65%) objects with spectra uncorrupted by radio
frequency interference, among which 45 (68%) have line profiles with adequate
signal-to-noise ratio and sufficiently reliable inclination corrections to
yield robust deprojected rotational velocities. This paper presents the basic
survey products, including an atlas of H I spectra, measurements of H I flux,
line width, profile asymmetry, optical images, optical spectroscopic
parameters, as well as a summary of a number of derived properties pertaining
to the host galaxies. To enlarge our primary sample, we also assemble all
previously published H I measurements of type 1 AGNs for which can can estimate
black hole masses, which total an additional 53 objects. The final
comprehensive compilation of 154 broad-line active galaxies, by far the largest
sample ever studied, forms the basis of our companion paper, which uses the H I
database to explore a number of properties of the AGN host galaxies.Comment: To appear in ApJS; 31 pages. Preprint will full-resolution figures
can be downloaded from http://www.ociw.edu/~lho/preprints/ms1.pd
Die Potenziale der Energieeinsparung in der Abwasserwirtschaft
Welche Potenziale birgt die Abwasserwirtschaft im Sinne der Klimaschutzziele? Und welche rechtlichen Rahmenbedingungen sind dabei zu berĂŒcksichtigen? Durch innovative AnsĂ€tze sowie die Einbindung in den Energiemarkt können erhebliche Effizienzpotenziale ausgeschöpft werden
Metabolomic Profiling in Patients with Heart Failure and Exercise Intolerance: Kynurenine as a Potential Biomarker
Aims: Metabolic and structural perturbations in skeletal muscle have been found in patients with heart failure (HF) both with preserved (HFpEF) and reduced (HFrEF) ejection fraction in association with reduced muscle endurance (RME). We aimed in the current study to create phenotypes for patients with RME and HFpEF compared to RME HFrEF according to their metabolomic profiles and to test the potential of Kynurenine (Kyn) as a marker for RME. Methods: Altogether, 18 HFrEF, 17 HFpEF, and 20 healthy controls (HC) were prospectively included in the current study. The following tests were performed on all participants: isokinetic muscle function tests, echocardiography, spiroergometry, and varied blood tests. Liquid chromatography tandem mass spectrometry was used to quantify metabolites in serum. Results: Except for aromatic and branched amino acids (AA), patients with HF showed reduced AAs compared to HC. Further perturbations were elevated concentrations of Kyn and acylcarnitines (ACs) in HFpEF and HFrEF patients ( p < 0.05). While patients with HFpEF and RME presented with reduced concentrations of ACs (long- and medium-chains), those with HFrEF and RME had distorted AAs metabolism ( p < 0.05). With an area under the curve (AUC) of 0.83, Kyn shows potential as a marker in HF and RME (specificity 70%, sensitivity 83%). In a multiple regression model consisting of short-chain-ACs, spermine, ornithine, glutamate, and Kyn, the latest was an independent predictor for RME (95% CI: â13.01, â3.30, B: â8.2 per 1 ”M increase, p = 0.001). Conclusions: RME in patients with HFpEF vs. HFrEF proved to have different metabolomic profiles suggesting varied pathophysiology. Kyn might be a promising biomarker for patients with HF and RME
Gpr124 is essential for blood-brain barrier integrity in central nervous system disease
Although blood-brain barrier (BBB) compromise is central to the etiology of diverse central nervous system (CNS) disorders, endothelial receptor proteins that control BBB function are poorly defined. The endothelial G-protein-coupled receptor (GPCR) Gpr124 has been reported to be required for normal forebrain angiogenesis and BBB function in mouse embryos, but the role of this receptor in adult animals is unknown. Here Gpr124 conditional knockout (CKO) in the endothelia of adult mice did not affect homeostatic BBB integrity, but resulted in BBB disruption and microvascular hemorrhage in mouse models of both ischemic stroke and glioblastoma, accompanied by reduced cerebrovascular canonical Wnt-ÎČ-catenin signaling. Constitutive activation of Wnt-ÎČ-catenin signaling fully corrected the BBB disruption and hemorrhage defects of Gpr124-CKO mice, with rescue of the endothelial gene tight junction, pericyte coverage and extracellular-matrix deficits. We thus identify Gpr124 as an endothelial GPCR specifically required for endothelial Wnt signaling and BBB integrity under pathological conditions in adult mice. This finding implicates Gpr124 as a potential therapeutic target for human CNS disorders characterized by BBB disruption
A principal component meta-analysis on multiple anthropometric traits identifies novel loci for body shape
Large consortia have revealed hundreds of genetic loci associated with anthropometric traits, one trait at a time. We examined whether genetic variants affect body shape as a composite phenotype that is represented by a combination of anthropometric traits. We developed an approach that calculates averaged PCs (AvPCs) representing body shape derived from six anthropometric traits (body mass index, height, weight, waist and hip circumference, waist-to-hip ratio). The first four AvPCs explain >99% of the variability, are heritable, and associate with cardiometabolic outcomes. We performed genome-wide association analyses for each body shape composite phenotype across 65 studies and meta-analysed summary statistics. We identify six novel loci: LEMD2 and CD47 for AvPC1, RPS6KA5/C14orf159 and GANAB for AvPC3, and ARL15 and ANP32 for AvPC4. Our findings highlight the value of using multiple traits to define complex phenotypes for discovery, which are not captured by single-trait analyses, and may shed light onto new pathways
Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans
Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have
fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in
25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16
regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of
correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP,
while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in
Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium
(LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region.
Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant
enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the
refined data for existing association signals, we estimate that these loci now explain âŒ38.9% of the familial relative risk of PrCa,
an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of
PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent
signals within the same regio
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