Durham University

About: Durham University is a education organization based out in Durham, United Kingdom. It is known for research contribution in the topics: Population & Galaxy. The organization has 39385 authors who have published 82311 publications receiving 3110994 citations. The organization is also known as: University of Durham & Gallery of Durham University.

Blockchain technology in the energy sector: A systematic review of challenges and opportunities

Abstract: Blockchains or distributed ledgers are an emerging technology that has drawn considerable interest from energy supply firms, startups, technology developers, financial institutions, national governments and the academic community. Numerous sources coming from these backgrounds identify blockchains as having the potential to bring significant benefits and innovation. Blockchains promise transparent, tamper-proof and secure systems that can enable novel business solutions, especially when combined with smart contracts. This work provides a comprehensive overview of fundamental principles that underpin blockchain technologies, such as system architectures and distributed consensus algorithms. Next, we focus on blockchain solutions for the energy industry and inform the state-of-the-art by thoroughly reviewing the literature and current business cases. To our knowledge, this is one of the first academic, peer-reviewed works to provide a systematic review of blockchain activities and initiatives in the energy sector. Our study reviews 140 blockchain research projects and startups from which we construct a map of the potential and relevance of blockchains for energy applications. These initiatives were systematically classified into different groups according to the field of activity, implementation platform and consensus strategy used. 1 Opportunities, potential challenges and limitations for a number of use cases are discussed, ranging from emerging peer-to-peer (P2P) energy trading and Internet of Things (IoT) applications, to decentralised marketplaces, electric vehicle charging and e-mobility. For each of these use cases, our contribution is twofold: first, in identifying the technical challenges that blockchain technology can solve for that application as well as its potential drawbacks, and second in briefly presenting the research and industrial projects and startups that are currently applying blockchain technology to that area. The paper ends with a discussion of challenges and market barriers the technology needs to overcome to get past the hype phase, prove its commercial viability and finally be adopted in the mainstream.

The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances

Abstract: We report data for I-band surface brightness fluctuation (SBF) magnitudes, (V-I) colors, and distance moduli for 300 galaxies. The survey contains E, S0, and early-type spiral galaxies in the proportions of 49 : 42 : 9 and is essentially complete for E galaxies to Hubble velocities of 2000 km s-1, with a substantial sampling of E galaxies out to 4000 km s-1. The median error in distance modulus is 0.22 mag. We also present two new results from the survey. (1) We compare the mean peculiar flow velocity (bulk flow) implied by our distances with predictions of typical cold dark matter transfer functions as a function of scale, and we find very good agreement with cold, dark matter cosmologies if the transfer function scale parameter Γ and the power spectrum normalization σ8 are related by σ8Γ-0.5 ≈ 2 ± 0.5. Derived directly from velocities, this result is independent of the distribution of galaxies or models for biasing. This modest bulk flow contradicts reports of large-scale, large-amplitude flows in the ~200 Mpc diameter volume surrounding our survey volume. (2) We present a distance-independent measure of absolute galaxy luminosity, and show how it correlates with galaxy properties such as color and velocity dispersion, demonstrating its utility for measuring galaxy distances through large and unknown extinction.

Binding of human apolipoprotein E to synthetic amyloid beta peptide: isoform-specific effects and implications for late-onset Alzheimer disease

Abstract: Apolipoprotein E (apoE), a plasma apolipoprotein that plays a central role in lipoprotein metabolism, is localized in the senile plaques, congophilic angiopathy, and neurofibrillary tangles of Alzheimer disease. Late-onset familial and sporadic Alzheimer disease patients have an increased frequency of one of the three common apoE alleles, epsilon 4, suggesting apoE4 is associated with increased susceptibility to disease. To follow up on this suggestion, we compared the binding of synthetic amyloid beta (beta/A4) peptide to purified apoE4 and apoE3, the most common isoform. Both isoforms bound synthetic beta/A4 peptide, the primary constituent of the plaque and angiopathy, forming a complex that resisted dissociation by boiling in SDS. Oxygen-mediated complex formation was implicated because binding was increased in oxygenated buffer, reduced in nitrogen-purged buffer, and prevented by reduction with dithiothreitol or 2-mercaptoethanol. Binding of beta/A4 peptide was saturable at 10(-4) M peptide and required residues 12-28. Examination of apoE fragments revealed that residues 244-272 are critical for complex formation. Both oxidized apoE4 and apoE3 bound beta/A4 peptide; however, binding to apoE4 was observed in minutes, whereas binding to apoE3 required hours. In addition, apoE4 did not bind beta/A4 peptide at pH < 6.6, whereas apoE3 bound beta/A4 peptide from pH 7.6 to 4.6. Together these results indicate differences in the two isoforms in complexing with the beta/A4 peptide. Binding of beta/A4 peptide by oxidized apoE may determine the sequestration or targeting of either apoE or beta/A4 peptide, and isoform-specific differences in apoE binding or oxidation may be involved in the pathogenesis of the intra- and extracellular lesions of Alzheimer disease.

Nonlinear fluid dynamics from gravity

Abstract: Black branes in AdS5 appear in a four parameter family labeled by their velocity and temperature. Promoting these parameters to Goldstone modes or collective coordinate fields—arbitrary functions of the coordinates on the boundary of AdS5—we use Einstein's equations together with regularity requirements and boundary conditions to determine their dynamics. The resultant equations turn out to be those of boundary fluid dynamics, with specific values for fluid parameters. Our analysis is perturbative in the boundary derivative expansion but is valid for arbitrary amplitudes. Our work may be regarded as a derivation of the nonlinear equations of boundary fluid dynamics from gravity. As a concrete application we find an explicit expression for the expansion of this fluid stress tensor including terms up to second order in the derivative expansion.