First-principles study of H intercalation in rutile TiO2

Published versio

Capitalist farming in Brazil: An analysis of the strategies of accumulation on large holdings in the 1980s

This study is basically a discussion of the strategies of capital accumulation in large holdings in Brazilian agriculture, specifically in the State of Parana. Despite the limits of economy of size and the physical constraints to expansion of capital towards land-based activities, large operations have been increased in agriculture, favoured by the conditions of access to land and its inherent market, by the characteristics of official policies and by the dynamics of specific activities, namely those linked to the external market. The analysis is particularly related to the 1980s, when the project of transforming the latifundio into rural enterprise, launched in the late 1960s, was at stake in an economic crisis which forced the government to withdraw from agriculture most of the financial benefits based on subsidised credit. As a consequence of this turning point, farmers' political organisations re-emerged to demand stable support from the state for an agriculture unable to face the crisis on its own. On the other hand, agricultural entrepreneurship showed itself to be largely specific, inasmuch as its income growth follows a very unstable process determined mainly by price variations of each commodity, by oscillations of the land market and by the returns provided by alternative investment in the urban economy. To a large extent, farming entrepreneurs, who represent agrarian capital, have, as part of their survival strategies, begun to loosen their links with land-based activities. Simultaneously, the conditions for agriculture becoming a field of investment attractive to capital have emerged from economic interests over landownership itself, from the protection provided by the state, and finally from the profitable returns of specific activities, mainly those linked to external market and the agroindustrial complex

Tissue-specific silencing of homoeologs in natural populations of the recent allopolyploid Tragopogon mirus

The definitive version is available at www3.interscience.wiley.com http://dx.doi.org/10.1111/j.1469-8137.2010.03205.

The influence of institutional pressures on climate mitigation and adaptation strategies

Starting from institutional theory, this study aims to explore the effects of coercive, normative and mimetic pressures on businesses climate change mitigation and adaptation strategies. In order to test these hypotheses, the study relies on an econometric model by using data from 487 Italian manufacturing companies collected by a questionnaire-based survey. The empirical model based on a multivariate regression reveals that companies which perceive normative and mimetic pressures are more likely to have a higher climate change sensitivity. Moreover, companies with a higher climate change sensitivity are more likely to adopt both mitigation and adaptation strategies. The article provides several contributions. First the study contributes to the debate among institutional scholars by clarifying which institutional pressures exert a more incisive effect on pushing companies to adopt climate actions. Second, it highlights how internal factors play a mediating role between institutional pressures and business climate responses

The effect of temperature on the ammoniation of wheat straw by urea

No Abstract

Expanding the set of rhodococcal Baeyer–Villiger monooxygenases by high-throughput cloning, expression and substrate screening

To expand the available set of Baeyer–Villiger monooxygenases (BVMOs), we have created expression constructs for producing 22 Type I BVMOs that are present in the genome of Rhodococcus jostii RHA1. Each BVMO has been probed with a large panel of potential substrates. Except for testing their substrate acceptance, also the enantioselectivity of some selected BVMOs was studied. The results provide insight into the biocatalytic potential of this collection of BVMOs and expand the biocatalytic repertoire known for BVMOs. This study also sheds light on the catalytic capacity of this large set of BVMOs that is present in this specific actinomycete. Furthermore, a comparative sequence analysis revealed a new BVMO-typifying sequence motif. This motif represents a useful tool for effective future genome mining efforts.

Spectropolarimetry of Supernovae

Overwhelming evidence has accumulated in recent years that supernova explosions are intrinsically 3-dimensional phenomena with significant departures from spherical symmetry. We review the evidence derived from spectropolarimetry that has established several key results: virtually all supernovae are significantly aspherical near maximum light; core-collapse supernovae behave differently than thermonuclear (Type Ia) supernovae; the asphericity of core-collapse supernovae is stronger in the inner layers showing that the explosion process itself is strongly aspherical; core-collapse supernovae tend to establish a preferred direction of asymmetry; the asphericity is stronger in the outer layers of thermonuclear supernovae providing constraints on the burning process. We emphasize the utility of the Q/U plane as a diagnostic tool and revisit SN 1987A and SN 1993J in a contemporary context. An axially-symmetric geometry can explain many basic features of core-collapse supernovae, but significant departures from axial symmetry are needed to explain most events. We introduce a spectropolarimetry type to classify the range of behavior observed in polarized supernovae. Understanding asymmetries in supernovae is important for phenomena as diverse as the origins of gamma-ray bursts and the cosmological applications of Type Ia supernovae in studies of the dark energy content of the universe.Comment: Draft of Annual Review article prior to final copy editing; 85 pages, 13 figures, 1 tabl

Avalanche precursors of failure in hierarchical fuse networks

We study precursors of failure in hierarchical random fuse network models which can be considered as idealizations of hierarchical (bio)materials where fibrous assemblies are held together by multi-level (hierarchical) cross-links. When such structures are loaded towards failure, the patterns of precursory avalanche activity exhibit generic scale invariance: Irrespective of load, precursor activity is characterized by power-law avalanche size distributions without apparent cut-off, with power-law exponents that decrease continuously with increasing load. This failure behavior and the ensuing super-rough crack morphology differ significantly from the findings in non-hierarchical structures

Design and proof of concept for multi degree of freedom hydrostatically coupled dielectric elastomer actuators with roto-translational kinematics for object handling

In this article we present an upgraded design of the existing push-pull hydrostatically coupled dielectric elastomer actuator (HC-DEA) for use in the field of soft manipulators. The new design has segmented electrodes, which stand as four independent elements on the active membrane of the actuator. When properly operated, the actuator can generate both out of plane and in-plane motions resulting in a multi-degrees of freedom soft actuator able to exert both normal pushes (like a traditional HC-DEA) and tangential thrusts. This novel design makes the actuator suitable for delicate flat object transportation. In order to use the actuator in soft systems, we experimentally characterized its electromechanical transduction and modeled its contact mechanics. Finally, we show that the proposed actuator can be employed as a modular unit to develop active surfaces for flat object roto-translation. © 2018 IOP Publishing Ltd