3,186 research outputs found
Effect of rotation and short-term tillage on soil quality after long-term zero tillage
Non-Peer ReviewedA field study was established in 2000, near Brandon Manitoba, to determine the effect of tillage and crop on soil physical and biological properties. Most soil physical and biological properties were not affected by tillage system or current year crop when sampled in the fall after harvest. The proportion of large (38 to 68.8 mm diameter) dry sieved aggregates increased under low compared to high intensities of tillage. Aggregate stability increased with increasing concentration of organic carbon. The effect of high and low intensity tillage over one or two years, after 9 years in zero tillage, on soil organic carbon, physical properties and fertility was not significant
Reflexion M\"ossbauer analysis of the in situ oxidation products hydroxycarbonate green rust
The purpose of this study is to determine the nature of the oxidation
products of FeII-III hydroxycarbonate FeII4FeIII2(OH)12CO3~3H2O (green rust
GR(CO32-)) by using the miniaturised M\"ossbauer spectrometer MIMOS II. Two
M\"ossbauer measurements methods are used: method (i) with green rust pastes
coated with glycerol and spread into Plexiglas sample holders, and method (ii)
with green rust pastes in the same sample holders but introduced into a
gas-tight cell with a beryllium window under a continuous nitrogen flow. Method
(ii) allows us to follow the continuous deprotonation of GR(CO32-) into the
fully ferric deprotonated form FeIII6O4(OH)8CO3~3H2O by adding the correct
amount of H2O2, without any further oxidation or degradation of the samples
Self-enforcing cooperation via strategic investment
We investigate how, in a situation with two players in which noncooperation is the only equilibrium, cooperation can be achieved via costly investment. We find that in the resulting equilibria, cooperation is an all-or-nothing outcome, that is, either there is full cooperation by both players, or no cooperation at all. The cost of investment is unrelated to the degree of cooperation that is ultimately achieved, unless the cost is too high, in which case investment cannot in any degree overcome the disincentive to cooperate. Moreover, the positive externalities that players have on each other in the course of play, although they affect investment, are ultimately irrelevant to the degree of cooperation achieved. We view our model as an explanation for the formation and stable existence of business alliances, where the players are firms forming a partnership defined and sustained by contractual agreements, but which is short of a merger or acquisition
Intelligent GIS: Automatic generation of qualitative spatial information
This paper reports on an extension to Geographic Information Systems (GIS) that can intelligently analyse and record qualitative information of the surrounding area when adding a feature to a map. This recorded qualitative spatial information can be utilised to perform queries such as path generation using landmarks. Although, there is a lot of research on qualitative spatial reasoning, none of the currently available GIS do actually incorporate this kind of functionality. There have been systems developed that do have functions for adding new features, or generating paths; however they do not generally analyse and record, or use, qualitative information. We have implemented a prototype illustrating our approach. © Springer-Verlag Berlin Heidelberg 2006
Cooling Tests of the NectarCAM camera for the Cherenkov Telescope Array
The NectarCAM is a camera proposed for the medium-sized telescopes in the
framework of the Cherenkov Telescope Array (CTA), the next-generation
observatory for very-high-energy gamma-ray astronomy. The cameras are designed
to operate in an open environment and their mechanics must provide protection
for all their components under the conditions defined for the CTA observatory.
In order to operate in a stable environment and ensure the best physics
performance, each NectarCAM will be enclosed in a slightly overpressurized,
nearly air-tight, camera body, to prevent dust and water from entering. The
total power dissipation will be ~7.7 kW for a 1855-pixel camera. The largest
fraction is dissipated by the readout electronics in the modules. We present
the design and implementation of the cooling system together with the test
bench results obtained on the NectarCAM thermal demonstrator.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Energy-momentum conservation in pre-metric electrodynamics with magnetic charges
A necessary and sufficient condition for energy-momentum conservation is
proved within a topological, pre-metric approach to classical electrodynamics
including magnetic as well as electric charges. The extended Lorentz force,
consisting of mutual actions by F=(E, B) on the electric current and G=(H, D)
on the magnetic current, can be derived from an energy-momentum "potential" if
and only if the constitutive relation G=G(F) satisfies a certain vanishing
condition. The electric-magnetic reciprocity introduced by Hehl and Obukhov is
seen to define a complex structure on the tensor product of 2-form pairs (F,G)
which is independent of but consistent with the Hodge star operator defined by
any Lorentzian metric. Contrary to a recent claim in the literature, it does
not define a complex structure on the space of 2-forms itself.Comment: 8 pages, 1 fugur
Judges' perceptions of expert reports: The effect of neuroscience evidence.
This article explores the impact of neuroscience evidence on how expert reports are perceived and their effects on the decisions made by trial judges. Experimental psychology has demonstrated a number of cognitive effects arising from exposure to neuroimaging data which may bias judgments and lead to (mis)interpretations that can affect decisions. We conducted a study on a sample of 62 Swiss and French judges in order to determine whether their perceptions of the credibility, quality and scientific basis of a psychiatric evaluation of a criminal defendant vary according to whether or not the evaluation includes neuroscientific data. Quantitative analyses were conducted in order to evaluate significant differences between the two conditions (one-way analyses of variance) and moderation and conditional analyses to examine whether the participants' sex and length of professional experience moderated the effect of the conditions. Terminological and thematic analyses were carried out on open questions. Quantitative and qualitative results suggest that the presence of neuroscience data in an expert report affects judges' perceptions of the quality, credibility, and scientificity (reliability, objectivity, scientific basis) of the report, and the persuasiveness of the evidence it provided. Moreover, this phenomenon was stronger in more experienced judges than in less experienced judges
A Survey on Approximation Mechanism Design without Money for Facility Games
In a facility game one or more facilities are placed in a metric space to
serve a set of selfish agents whose addresses are their private information. In
a classical facility game, each agent wants to be as close to a facility as
possible, and the cost of an agent can be defined as the distance between her
location and the closest facility. In an obnoxious facility game, each agent
wants to be far away from all facilities, and her utility is the distance from
her location to the facility set. The objective of each agent is to minimize
her cost or maximize her utility. An agent may lie if, by doing so, more
benefit can be obtained. We are interested in social choice mechanisms that do
not utilize payments. The game designer aims at a mechanism that is
strategy-proof, in the sense that any agent cannot benefit by misreporting her
address, or, even better, group strategy-proof, in the sense that any coalition
of agents cannot all benefit by lying. Meanwhile, it is desirable to have the
mechanism to be approximately optimal with respect to a chosen objective
function. Several models for such approximation mechanism design without money
for facility games have been proposed. In this paper we briefly review these
models and related results for both deterministic and randomized mechanisms,
and meanwhile we present a general framework for approximation mechanism design
without money for facility games
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