4,617 research outputs found
Assessment of a satellite power system and six alternative technologies
The satellite power system is assessed in comparison to six alternative technologies. The alternatives are: central-station terrestrial photovoltaic systems, conventional coal-fired power plants, coal-gasification/combined-cycle power plants, light water reactor power plants, liquid-metal fast-breeder reactors, and fusion. The comparison is made regarding issues of cost and performance, health and safety, environmental effects, resources, socio-economic factors, and institutional issues. The criteria for selecting the issues and the alternative technologies are given, and the methodology of the comparison is discussed. Brief descriptions of each of the technologies considered are included
Partial Photoionization Cross Sections And Photoelectron Angular Distributions For Double Excitations Up To The N=5 Threshold In Helium
Partial photoionization cross sections sigma(n) and photoelectron angular distributions beta(n) were measured for all possible final ionic states He+(n) in the region of the double excitations N(K,T)(A) up to the N=5 threshold. At a photon energy bandpass of 12 meV below the thresholds N=3,4, and 5, this level of differentiation offers the most critical assessment of the dynamics of the two-electron excitations to date. The experimental data are very well described by the most advanced theoretical calculations. Weaker double-excitation series with K=N-4 are clearly visible in the beta(n) data, and even previously unobserved extremely weak series members with A=-1 can be discerned, showing the high sensitivity of the angular resolved measurements. The shapes of the resonance-induced variations of sigma(n) or beta(n) in the double excitations below a given threshold N change radically depending on the final ionic state n but display striking similarities when comparing the satellite states with n=N-1 and n=N-2 below each threshold N. These systematic patterns may indicate a general rule for the underlying two-electron dynamics
Resilience to climate shocks in the tropics
This focus collection on resilience to climate shocks in the tropics draws together 16 papers that predominantly examine the impacts of, and responses to, the 2015/2016 El Niño-Southern Oscillation event, in a range of contexts. This introductory synthesis contextualises the collection of papers by reviewing important concepts and highlighting some important insights that emerge from the collection. The papers in this collection collectively highlight: the value of longitudinal and interdisciplinary research in understanding both the roots of, and responses to, resilience challenges; the critical interaction between climatic and land-use changes; and the ways in which governance arrangements underpin societal decision-making across a range of scales and contexts to shape resilience
The Legacy of ERA, Privatization and the Policy Ratchet
This article explores the ways in which the neo-liberal impetus toward the privatization of state schooling signalled in the Education Reform Act 1988 (ERA) has become embedded in the English school system. Four main points are made. First, that ERA itself was of huge strategic rather than substantive importance as far as privatization is concerned. Second, by tracing the lineage of privatization from ERA onwards a 'ratchet' effect of small and incremental policy moves can be identified, which have disseminated, embedded and naturalized privatization within public sector provision. Third, that while privatization has been taken up and taken much further by New Labour than it had been by the Conservatives there are differences between the two sets of governments in the role of privatization in education policy and the role of the state. Fourth, the participation of private providers in the planning and delivery of state services has put the private sector at the very heart of policy. At points the article draws upon interviews conducted with private sector providers. © 2008 Sage Publications
Cloning of a gene encoding an antigen associated with the centrosome in Drosophila
The monoclonal antibody Bx63 recognizes a centrosomal antigen of Drosophila melanogaster by indirect immunofluorescence and identifies two proteins, with apparent molecular weights of 185 x 10³ and 66 x 10³, on Western blots. We have used this antibody to isolate five clones (λcs1, -2, -3, -4 and λj63) from λgt11 expression libraries of Drosophila DNA. Using polyclonal anti-centrosomal sera raised against both immunoaffinity-purified Bx63 antigen and electrophoretically purified fusion protein from clone λcs3, we have demonstrated that the fusion proteins encoded by four of these clones (λcs1-4) share at least two epitopes with the 185 x 10³ M_r centrosomal antigen. This indicates that clones λcs1-4 contain DNA from the gene coding for this protein. The four clones are independent isolates from a single chromosomal site, which we show by in situ hybridization to correspond with salivary gland chromosome region 88E 4-8. A low-abundance transcript of approximately 4.0 x 10³ bases corresponding to the cloned gene is detected in all stages of the Drosophila life-cycle
Cloning of a gene encoding an antigen associated with the centrosome in Drosophila
The monoclonal antibody Bx63 recognizes a centrosomal antigen of Drosophila melanogaster by indirect immunofluorescence and identifies two proteins, with apparent molecular weights of 185 x 10³ and 66 x 10³, on Western blots. We have used this antibody to isolate five clones (λcs1, -2, -3, -4 and λj63) from λgt11 expression libraries of Drosophila DNA. Using polyclonal anti-centrosomal sera raised against both immunoaffinity-purified Bx63 antigen and electrophoretically purified fusion protein from clone λcs3, we have demonstrated that the fusion proteins encoded by four of these clones (λcs1-4) share at least two epitopes with the 185 x 10³ M_r centrosomal antigen. This indicates that clones λcs1-4 contain DNA from the gene coding for this protein. The four clones are independent isolates from a single chromosomal site, which we show by in situ hybridization to correspond with salivary gland chromosome region 88E 4-8. A low-abundance transcript of approximately 4.0 x 10³ bases corresponding to the cloned gene is detected in all stages of the Drosophila life-cycle
Computational Complexity of Time-Dependent Density Functional Theory
Time-dependent density functional theory (TDDFT) is rapidly emerging as a premier method for solving dynamical many-body problems in physics and chemistry. The mathematical foundations of TDDFT are established through the formal existence of a fictitious non-interacting system (known as the Kohn–Sham system), which can reproduce the one-electron reduced probability density of the actual system. We build upon these works and show that on the interior of the domain of existence, the Kohn–Sham system can be efficiently obtained given the time-dependent density. We introduce a V-representability parameter which diverges at the boundary of the existence domain and serves to quantify the numerical difficulty of constructing the Kohn–Sham potential. For bounded values of V-representability, we present a polynomial time quantum algorithm to generate the time-dependent Kohn–Sham potential with controllable error bounds.Chemistry and Chemical Biolog
Supporting 'design for reuse' with modular design
Engineering design reuse refers to the utilization of any knowledge gained from the design activity to support future design. As such, engineering design reuse approaches are concerned with the support, exploration, and enhancement of design knowledge prior, during, and after a design activity. Modular design is a product structuring principle whereby products are developed with distinct modules for rapid product development, efficient upgrades, and possible reuse (of the physical modules). The benefits of modular design center on a greater capacity for structuring component parts to better manage the relation between market requirements and the designed product. This study explores the capabilities of modular design principles to provide improved support for the engineering design reuse concept. The correlations between modular design and 'reuse' are highlighted, with the aim of identifying its potential to aid the little-supported process of design for reuse. In fulfilment of this objective the authors not only identify the requirements of design for reuse, but also propose how modular design principles can be extended to support design for reuse
Making a case for just agricultural transformation in the UNFCCC: An analysis of justice in the Koronivia Joint Work on Agriculture
Introduction: From 2018 to 2022, the Koronivia Joint Working Group on Agriculture (KJWA) was the key forum for debating global agricultural change and integrating agricultural transformation priorities into the mechanisms of the United Nations Framework Convention on Climate Change (UNFCCC). As a forerunner to the landmark decision at COP27 to initiate the Sharm El-Sheik Joint Work on Implementation of Climate Action on Agriculture and Food Security, it provided an opportunity to further the (as yet underdeveloped) discourse around social transformation and just transformation in agriculture. At the conclusion of this 4 year process, we ask: to what extent and in what ways has a just agricultural transformation been envisioned within the Koronivia Joint Working Group on Agriculture and what are the implications for the Sharm El-Sheik Joint Work on Implementation?
Methods: The paper presents a textual analysis of 155 written submissions, workshops, and concluding statements from across the full programme of KJWA workshops, meetings, and consultations.
Results: We find that references to just transformations in agriculture within KJWA are largely implicit, but not absent. We argue that justice has been most obvious and evident when it comes to discussion about who is (and where are) the most vulnerable to climate change and variability, and how access to climate smart technologies and information is distributed. Less evident have been discussions about just representation in the governance and visioning of agricultural transformation, and there have been few explicit appeals to address the historical injustices that have shaped agricultural and rural livelihoods in the Global South.
Discussion: We argue that following its conclusion, there is a danger that the outcomes of KJWA become reduced to a focus on the scaling up of a techno-centric vision of agricultural transformation. To counter this, there is need for ongoing dialogue to develop a shared and more complete understanding of justice that should be central to how agricultural transformation is integrated into the UNFCCC. We highlight some recommendations of how a justice agenda could be taken forward under the Sharm El-Sheik Joint Work on Implementation
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