4,163 research outputs found
Reactive nitrogen in the Spanish agri-food sector: environmental impact on atmosphere, soils, water and resources.
The presence of reactive species of nitrogen (N) in the biosphere might cause environmental impacts at local, regional and global scales. Nowadays the N flows generated by human activities greatly exceed natural processes, thus a necessity exists of identifying and quantifying the current state of environmental N loads. The aim of this work is to quantify the amount of reactive N used in the Spanish agri-food sector, assessing the related potential environmental impacts and potential uses of resources. Data from a previously calculated N flow analysis in the Spanish agricultural and food production system for the 1996-2000 time period were used. Total anthropogenic N inputs to the systems were calculated. Input and output flows were considered in each economic compartment in order to calculate use efficiency (ratio of useful outputs to total inputs), eco-efficiency (ratio of useful outputs to outputs to the environment) and recycling rate (ratio of flow recycled to an earlier life-cycle compartment divided by total outputs). Environmental impacts were assessed by quantifying the N balance between the economic and the environmental subsystems: water, atmosphere, ecosystems soils and other soils. In this case agricultural soils were also considered an environmental compartment, since they are an important intermediate path to the environment. The impact on resources was evaluated considering the net N imports into the system and legume fixing crops, pastures and forages versus feed and fertilizers within the system. Anthropogenic N inputs are relatively high in Spain, which is a net importer of nitrogen, mainly in fertilizers and food and feed commodities. Environmental compartments receive relative high amounts of reactive nitrogen, especially soils. Furthermore, there was a relative
low use of domestic resources, with a low proportion of N recycled within the system
About the Infinite Repetition of Histories in Space
This paper analyzes two different proposals, one by Ellis and Brundrit, based
on classical relativistic cosmology, the other by Garriga and Vilenkin, based
on the DH interpretation of quantum mechanics, both of which conclude that, in
an infinite universe, planets and living beings must be repeated an infinite
number of times. We point to some possible shortcomings in the arguments of
these authors. We conclude that the idea of an infinite repetition of histories
in space cannot be considered strictly speaking a consequence of current
physics and cosmology. Such ideas should be seen rather as examples of
{\guillemotleft}ironic science{\guillemotright} in the terminology of John
Horgan.Comment: 14 pages, no figures. Accepted for publication in slightly different
form at THEORIA (http://www.ehu.es/ojs/index.php/THEORIA
Magnetised Polish doughnuts revisited
We discuss a procedure to build new sequences of magnetised, equilibrium tori
around Kerr black holes which combines two approaches previously considered in
the literature. For simplicity we assume that the test-fluid approximation
holds, and hence we neglect the self-gravity of the fluid. The models are built
assuming a particular form of the angular momentum distribution from which the
location and morphology of equipotential surfaces can be computed. This ansatz
includes, in particular, the constant angular momentum case originally employed
in the construction of thick tori - or Polish doughnuts - and it has already
been used to build equilibrium sequences of purely hydrodynamical models. We
discuss the properties of the new models and their dependence on the initial
parameters. These new sequences can be used as initial data for
magnetohydrodynamical evolutions in general relativity.Comment: 9 pages, 6 figures. Accepted for publication in Astronomy &
Astrophysics July 12, 201
The future obligations of "project manager" as construction integral director (DIPE) in the law of buildings construction in spain (LOE)
In the year 1999 approves the Law of Construction Building (LOE, in Spanish) to regulate a sector such as construction, which contained some shortcomings from the legal point of view. Currently, the LOE has been in force 12 years, changing the spanish world of the construction, due to influenced by internationalization. Within the LOE, there regulating the different actors involved in the construction building, as the Projects design, the Director of Construction, the developer, The builder, Director of execution of the construction (actor only in Spain, similar as construcion engineer and abroad in), control entities and the users, but lacks figure Project manager will assume the delegation of the promoter helping and you organize, direct and management the process. This figure assumes that the market and contracts are not legally regulated in Spain, then should define and establish its regulation in the LOE. (Spain Construction Law) The translation in spanish of the words "Project Manager is owed to Professor Rafael de Heredia in his book Integrated Project Management, as agent acting on behalf of the organization and promoter assuming control of the project, ie Integraded Project Management . Already exist in Spain, AEDIP (Spanish Association Integrated of Project Construction management) which comprises the major companies in “Project Management” in Spain, and MeDIP (Master in Integrated Construction Project) the largest and most advanced studies at the Polytechnic University of Madrid, in "Construction Project Management" they teach which is also in Argentina. The Integrated Project ("Project Management") applied to the construction process is a methodological technique that helps to organize, control and manage the resources of the promoters in the building process. When resources are limited (which is usually most situations) to manage them efficiently becomes very important. Well, we find that in this situation, the resources are not only limited, but it is limited, so a comprehensive control and monitoring of them becomes not only important if not crucial. The alternative of starting from scratch with a team that specializes in developing these follow directly intervening to ensure that scarce resources are used in the best possible way requires the use of a specific methodology (Manual DIP, Matrix Foreign EDR breakdown structure EDP Project, Risk Management and Control, Design Management, et ..), that is the methodology used by "Projects managers" to ensure that the initial objectives of the promoters or investors are met and all actors in process, from design to construction company have the mind aim of the project will do, trying to get their interests do not prevail over the interests of the project. Among the agents listed in the building process, "Project Management" or DIPE (Director Comprehensive building process, a proposed name for possible incorporation into the LOE, ) currently not listed as such in the LOE (Act on Construction Planning ), one of the agents that exist within the building process is not regulated from the legal point of view, no obligations, ie, as is required by law to have a project, a builder, a construction management, etc. DIPE only one who wants to hire you as have been advanced knowledge of their services by the clients they have been hiring these agents, there being no legal obligation as mentioned above, then the market is dictating its ruling on this new figure, as if it were necessary, he was not hired and eventually disappeared from the building process. As the aim of this article is regular the process and implement the name of DIPE in the Spanish Law of buildings construction (LOE
Efficient implementation of a van der Waals density functional: Application to double-wall carbon nanotubes
We present an efficient implementation of the van der Waals density
functional of Dion et al [Phys. Rev. Lett. 92, 246401 (2004)], which expresses
the nonlocal correlation energy as a double spacial integral. We factorize the
integration kernel and use fast Fourier transforms to evaluate the
selfconsistent potential, total energy, and atomic forces, in N log(N)
operations. The resulting overhead in total computational cost, over semilocal
functionals, is very moderate for medium and large systems. We apply the method
to calculate the binding energies and the barriers for relative translation and
rotation in double-wall carbon nanotubes.Comment: 4 pages, 1 figure, 1 tabl
Detection of irrigation inhomogeneities in an olive grove using the NDRE vegetation index obtained from UAV images
We have developed a simple photogrammetric method to identify heterogeneous areas of irrigated olive groves and vineyard crops using a commercial multispectral camera mounted on an unmanned aerial vehicle (UAV). By comparing NDVI, GNDVI, SAVI, and NDRE vegetation indices, we find that the latter shows irrigation irregularities in an olive grove not discernible with the other indices. This may render the NDRE as particularly useful to identify growth inhomogeneities in crops. Given the fact that few satellite detectors are sensible in the red-edge (RE) band and none with the spatial resolution offered by UAVs, this finding has the potential of turning UAVs into a local farmer’s favourite aid tool.Peer ReviewedPostprint (published version
Informational structures and informational fields as a prototype for the description of postulates of the integrated information theory
Informational Structures (IS) and Informational Fields (IF) have been recently introduced
to deal with a continuous dynamical systems-based approach to Integrated Information Theory (IIT). IS and IF contain all the geometrical and topological constraints in the phase space. This allows one to characterize all the past and future dynamical scenarios for a system in any particular state. In this paper, we develop further steps in this direction, describing a proper continuous framework
for an abstract formulation, which could serve as a prototype of the IIT postulates.National Science Center of PolandUMO-2016/22/A/ST1/00077Junta de AndalucíaMinisterio de Economia, Industria y Competitividad (MINECO). Españ
- …