Balancing solar PV deployment and RD&D: A comprehensive framework for managing innovation uncertainty in electricity technology investment planning

We present a new framework for studying the socially optimal level of generating capacity and public RD&D investments for the electric power sector under decision-dependent technical change uncertainty. We construct a bottom-up stochastic electricity generation capacity expansion model with uncertain endogenous RD&D-based technical change, focusing on solar PV RD&D investment planning for its current prominent role in sustainable energy and climate policy deliberations. We characterize the decision-dependent process of technical change uncertainty as unknown outcomes of RD&D investments that increase the likelihood of success with increasing amounts of RD&D, and calibrate to a novel expert elicitation dataset that accounts for this decision-dependence. The problem is framed as a multi-stage decision under uncertainty, where the decision maker learns and adapts to new information between decision periods. Specifically, our application considers four decision stages, with the decision-maker choosing investment levels for new capacity and solar PV RD&D, while learning about RD&D outcomes that can reduce solar PV costs between each stage. The problem is thus formulated to match the manner in which real-world decisions about RD&D investments in renewable energy are made, and avoids common assumptions of perfect foresight, or uncertainty but no learning, that are often used in practice. Numerical results show that when uncertainty and learning features are both included, the optimal solar PV RD&D investment strategy changes from solutions using other methods. Considering uncertainty and learning results in solar RD&D investment differences as high as 20 percent lower in the first-stage, and 300 percent higher in later stages. We also show that when uncertainty is considered without learning, the fraction of new solar PV capacity investments can be depressed. Overall, this paper shows that it is possible to unify several realistic features of the deployment and development problem for the electricity sector to meet sustainability goals into one framework

Puerto Rican Amazon \u3ci\u3eAmazona vittata\u3c/i\u3e

Once numbering only 13 birds in the wild, this parrot has been saved from extinction. Conservation action has increased the population since 1975, but it remains Critically Endangered because the number of mature individuals remains tiny. If more released birds successfully breed in the wild and numbers remain stable or increasing, the species may warrant downlisting in the future

Spin Seebeck effect in Y-type hexagonal ferrite thin films

Spin Seebeck effect (SSE) has been investigated in thin films of two Y-hexagonal ferrites Ba$_2$Zn$_{2}$Fe$_{12}$O$_{22}$ (Zn2Y) and Ba$_2$Co$_{2}$Fe$_{12}$O$_{22}$ (Co2Y) deposited by a spin-coating method on SrTiO$_3$(111) substrate. The selected hexagonal ferrites are both ferrimagnetic with similar magnetic moments at room temperature and both exhibit easy magnetization plane normal to $c$-axis. Despite that, SSE signal was only observed for Zn2Y, whereas no significant SSE signal was detected for Co2Y. We tentatively explain this different behavior by a presence of two different magnetic ions in Co2Y, whose random distribution over octahedral sites interferes the long range ordering and enhances the Gilbert damping constant. The temperature dependence of SSE for Zn2Y was measured and analyzed with regard to the heat flux and temperature gradient relevant to the SSE signal.Comment: 7 pages, 9 figure

La recherche ethnographique en éducation

Cet ouvrage constitue une introduction générale essentielle aux méthodes de recherche en éducation et un outil de référence incontournable, tant pour le praticien que pour l'étudiant-chercheur, qu'il soit au baccalauréat, à la maîtrise ou au doctorat. Tout comme dans les éditions précédentes, les thèmes retenus répondent à des besoins variés et sont structurés de façon à ce que le lecteur trouve facilement son chemin à travers les nombreuses perspectives adoptées par les auteurs, qui accordent une attention particulière aux enjeux d'ordre épistémologique et éthique - au cœur de toute démarche de recherche. Le lecteur sera amené à découvrir la fascinante aventure de la recherche en éducation, ainsi que les défis qu'elle contient, dont celui - fondamental - de faciliter une plus grande collaboration entre praticiens et chercheurs. Cette quatrième édition comprend un nouveau chapitre sur la recherche ethnographique ainsi que sur l'analyse des données qualitatives

Characteristic length scale of the magnon accumulation in Fe3O4/Pt bilayer structures by incoherent thermal excitation

The dependence of Spin Seebeck effect (SSE) with the thickness of the magnetic materials is studied by means of incoherent thermal excitation. The SSE voltage signal in Fe3O4/Pt bilayer structure increases with the magnetic material thickness up to 100¿nm, approximately, showing signs of saturation for larger thickness. This dependence is well described in terms of a spin current pumped in the platinum film by the magnon accumulation in the magnetic material. The spin current is generated by a gradient of temperature in the system and detected by the Pt top contact by means of inverse spin Hall effect. Calculations in the frame of the linear response theory adjust with a high degree of accuracy the experimental data, giving a thermal length scale of the magnon accumulation (¿) of 17¿±¿3¿nm at 300¿K and ¿¿=¿40¿±¿10¿nm at 70¿K

Spin-orbit torque from the introduction of Cu interlayers in Pt/Cu/Co/Pt nanolayered structures for spintronic devices

Spin currents can modify the magnetic state of ferromagnetic ultrathin films through spin-orbit torque. They may be generated by means of spin-orbit interactions by either bulk or interfacial phenomena. Electrical transport measurements reveal a 6-fold increase of the spin-orbit torque accompanied by a drastic reduction of the spin Hall magnetoresistance upon the introduction of an ultrathin Cu interlayer in a Pt/Cu/Co/Pt structure with perpendicular magnetic anisotropy. We analyze the dependence of the spin Hall magnetoresistance with the thickness of the interlayer, ranging from 0.5 to 15 nm, in the frame of a drift diffusion model that provides information on the expected spin currents and spin accumulations in the system. The results demonstrate that the major responsibility of both effects is spin memory loss at the interface. The enhancement of the spin-orbit torque when introducing an interlayer opens the possibility to design more efficient spintronic devices based on materials that are cheap and abundant such as copper. More specifically, spin-orbit torque magnetic random access memories and spin logic devices could benefit from the spin-orbit torque enhancement and cheaper material usage presented in this study

Cholecystokinin in the central nervous system of the sea lamprey Petromyzon marinus: precursor identification and neuroanatomical relationships with other neuronal signalling systems

Cholecystokinin (CCK) is a neuropeptide that modulates processes such as digestion, satiety, and anxiety. CCK-type peptides have been characterized in jawed vertebrates and invertebrates, but little is known about CCK-type signalling in the most ancient group of vertebrates, the agnathans. Here, we have cloned and sequenced a cDNA encoding a sea lamprey (Petromyzon marinus L.) CCK-type precursor (PmCCK), which contains a CCK-type octapeptide sequence (PmCCK-8) that is highly similar to gnathostome CCKs. Using mRNA in situ hybridization, the distribution of PmCCK-expressing neurons was mapped in the CNS of P. marinus. This revealed PmCCK-expressing neurons in the hypothalamus, posterior tubercle, prethalamus, nucleus of the medial longitudinal fasciculus, midbrain tegmentum, isthmus, rhombencephalic reticular formation, and the putative nucleus of the solitary tract. Some PmCCK-expressing neuronal populations were only observed in adults, revealing important differences with larvae. We generated an antiserum to PmCCK-8 to enable immunohistochemical analysis of CCK expression, which revealed that GABA or glutamate, but not serotonin, tyrosine hydroxylase or neuropeptide Y, is co-expressed in some PmCCK-8-immunoreactive (ir) neurons. Importantly, this is the first demonstration of co-localization of GABA and CCK in neurons of a non-mammalian vertebrate. We also characterized extensive cholecystokinergic fibre systems of the CNS, including innervation of habenular subnuclei. A conspicuous PmCCK-8-ir tract ascending in the lateral rhombencephalon selectively innervates a glutamatergic population in the dorsal isthmic grey. Interestingly, this tract is reminiscent of the secondary gustatory/visceral tract of teleosts. In conclusion, this study provides important new information on the evolution of the cholecystokinergic system in vertebrates.</p

Guía de la excursión al Triásico de la Sierra de Prades

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