3,057 research outputs found
Innovation in the energy sector: advancing or frustrating climate policy goals?
The energy sector is well known for the relatively modest level of resource that it devotes to research and development (R&D). However, the incremental pace of energy innovation has speeded up in the last decade as measured by public sector R&D budgets, deployment of alternative technologies and novel institutional arrangements. While much of this effort has been targeted at technologies that promise to reduce carbon dioxide (CO2) emissions, there have also been major innovations that extend the fossil fuel resource base and reduce the cost of extraction. The last decadeâs developments can be seen in terms of a challenge to the existing energy paradigm in parallel with a renewed innovative response focusing on conventional fuels and technologies. This paper examines this tension, by exploring the expectations of a variety of organisations in both the public and private sector regarding energy sector developments and by analysing private sector expenditure on energy research and development (R&D) and public sector budgets for energy R&D and demonstration (RD&D). Scenarios and outlook exercises that have been published since 2013 reveal a wide range of beliefs about the future development of the energy system. The contrasting views underpinning the different scenarios are reflected in divergent patterns of R&D investment between the private and public sectors. There appears to be a tension between the drive to transform energy systems, on the part of public bodies, mainly motivated by the need to combat global climate change, and private sector activity, which tends to reinforce and extend existing patterns of energy provision. The paper addresses, but not answer definitively, the key question as to whether technological change is enabling or frustrating ambitious carbon goals
Determination of step rate thresholds corresponding to physical activity intensity classifications in adults
Current recommendations call for adults to be physically active at moderate and/or vigorous intensities. Given the popularity of walking and running, the use of step rates may provide a practical and inexpensive means to evaluate ambulatory intensity. Thus, the purpose of this study was to identify step rate thresholds that correspond to various intensity classifications. Methods: Oxygen consumption was measured at rest and during 10 minute treadmill walking and running trials at 6 standardized speeds (54, 80, 107, 134,
161, and 188 mâmin-1) in 9 men and 10 women (28.8 ± 6.8 yrs). Two observers counted the participantsâ steps
at each treadmill speed. Linear and nonlinear regression analyses were used to develop prediction equations
to ascertain step rate thresholds at various intensities. Results: Nonlinear regression analysis of the metabolic
cost versus step rates across all treadmill speeds yielded the highest R2 values for men (R2 = .91) and women
(R2 = .79). For men, the nonlinear analysis yielded 94 and 125 stepâmin-1 for moderate and vigorous intensities,
respectively. For women, 99 and 135 stepâmin-1 corresponded with moderate and vigorous intensities, respectively. Conclusions: Promoting a step rate of 100 stepâmin-1 may serve as a practical public health recommendation to exercise at moderate intensity
AlGaAs top solar cell for mechanical attachment in a multi-junction tandem concentrator solar cell stack
The AstroPower self-supporting, transparent AlGaAs top solar cell can be stacked upon any well-developed bottom solar cell for improved system performance. This is an approach to improve the performance and scale of space photovoltaic power systems. Mechanically stacked tandem solar cell concentrator systems based on the AlGaAs top concentrator solar cell can provide near term efficiencies of 36 percent (AMO, 100x). Possible tandem stack efficiencies greater than 38 percent (100x, AMO) are feasible with a careful selection of materials. In a three solar cell stack, system efficiencies exceed 41 percent (100x, AMO). These device results demonstrate a practical solution for a state-of-the-art top solar cell for attachment to an existing, well-developed solar cell
The global surge in energy innovation
Policymakers are seeking a transformation of the energy system driven by concerns about climate change, energy security and affordability. At the same time, emerging developments in underpinning science and engineering are opening up new possibilities across the whole technology spectrum covering renewables and other supply side technologies, energy demand and energy infrastructure. This paper reviews both the âpolicy pullâ for energy innovation activities and the âscience and technology pushâ. It explores the expectations of a variety of organisations in both the public and private sector regarding these pressures and possibilities by assessing various scenarios and outlook exercises that have been published since 2013. It reveals a wide range of beliefs about the future development of the energy system. The paper then moves on to analyse private sector expenditure on energy research and development (R&D) and public sector budgets for energy R&D and demonstration (RD&D). This analysis demonstrates significant divergences in patterns of innovation between the private and public sectors and leads to the hypothesis that the private sector is, broadly, taking measures to reinforce the existing energy paradigm while the public sector is focusing on new energy technologies that support wider policy objectives. This pattern is consistent with past technological transitions, with innovation efforts that would transform the energy system being counteracted by countervailing efforts that reinforce the existing fossil fuel-based paradigm
Facilitating and coordinating UK energy innovation through systemic innovation intermediaries
lncRNAs in development and disease: from functions to mechanisms
Differential expression of long non-coding RNAs (lncRNAs) during differentiation and their misregulation in cancer highlight their potential as cell fate regulators. While some example lncRNAs have been characterized in great detail, the functional in vivo relevance of others has been called into question. Finding functional lncRNAs will most probably require a combination of complementary approaches that will greatly vary depending on their mode of action. In this review, we discuss the different tools available to dissect genetically lncRNA requirements and how each is best suited to studies in particular contexts. Moreover, we review different strategies used to select candidate lncRNAs and give an overview of lncRNAs described to regulate development and cancer through different mechanisms.M.J.D. was funded by a PhD fellowship from Boehringer Ingelheim Fonds, a graduate studies fellowship from âla Caixaâ Foundation and by the Watson School of Biological Sciences. G.J.H. is a Wellcome Trust Investigator, was an investigator of the Howard Hughes Medical Institute, and is supported by Cancer Research UK, The Royal Society (Wolfson Professorship) and a generous gift from Kathryn W. Davis
Decoupling Graphene from SiC(0001) via Oxidation
When epitaxial graphene layers are formed on SiC(0001), the first carbon
layer (known as the "buffer layer"), while relatively easy to synthesize, does
not have the desirable electrical properties of graphene. The conductivity is
poor due to a disruption of the graphene pi-bands by covalent bonding to the
SiC substrate. Here we show that it is possible to restore the graphene
pi-bands by inserting a thin oxide layer between the buffer layer and SiC
substrate using a low temperature, CMOS-compatible process that does not damage
the graphene layer
The Atomic Slide Puzzle: Self-Diffusion of an Impure Atom
In a series of recent papers van Gastel et al have presented first
experimental evidence that impure, Indium atoms, embedded into the first layer
of a Cu(001) surface, are not localized within the close-packed surface layers
but make concerted, long excursions visualized in a series of STM images. Such
excursions occur due to continuous reshuffling of the surface following the
position exchanges of both impure and host atoms with the naturally occuring
surface vacancies. Van Gastel et al have also formulated an original
lattice-gas type model with asymmetric exchange probabilities, whose numerical
solution is in a good agreement with the experimental data. In this paper we
propose an exact lattice solution of several versions of this model.Comment: Latex, 4 pages, 2 figures, to appear in Phys. Rev. E (RC
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