1,298 research outputs found
Energy saving: From engineering to crop management
In greenhouse horticulture, energy costs form an increasingly larger part of the total production costs. Energy is primarily used for temperature control, reduction of air humidity, increase of light intensity and CO2 supply. Use of fossil energy can be reduced by limiting the energy demand of the system and decreasing energy losses, by intelligent climate control, by increasing the energy efficiency of the crop and by replacing fossil energy sources by sustainable ones. Energy requirement of the greenhouse can be lowered up to 20-30% by using greenhouse covers with higher insulating values and the use of energy screens. A prerequisite is that these materials should not involve considerable light loss, since this would result in a loss of production. In energy efficient greenhouse concepts, durable energy sources should be included. In (semi-)closed greenhouses, the excess of solar energy in summer is collected and stored in aquifers to be reused in winter to heat the greenhouse. Ventilation windows are closed, with specific benefits to the crop: high CO2 levels can be maintained, and temperature and humidity can be controlled to the needs of the crop. Development of new greenhouse concepts is ongoing. Current examples are greenhouse systems which convert natural energy sources such as solar energy into high-value energy such as electricity. Given a certain technical infrastructure of the greenhouse, energy consumption can be further reduced by energy efficient climate control and crop management. Essential elements are to allow fluctuating temperatures, lower crop transpiration, allow higher humidities, make efficient use of light and create fluent transitions in set points. Consequences for plant growth are related to rate of development, photosynthesis, assimilate distribution, transpiration and the occurrence of diseases or disorders. Since processes involved are complex, knowledge exchange between researchers and growers is essential to realize the goals set to reduce the energy consumption
Experimental verification of entanglement generated in a plasmonic system
A core process in many quantum tasks is the generation of entanglement. It is
being actively studied in a variety of physical settings - from simple
bipartite systems to complex multipartite systems. In this work we
experimentally study the generation of bipartite entanglement in a nanophotonic
system. Entanglement is generated via the quantum interference of two surface
plasmon polaritons in a beamsplitter structure, i.e. utilising the
Hong-Ou-Mandel (HOM) effect, and its presence is verified using quantum state
tomography. The amount of entanglement is quantified by the concurrence and we
find values of up to 0.77 +/- 0.04. Verifying entanglement in the output state
from HOM interference is a nontrivial task and cannot be inferred from the
visibility alone. The techniques we use to verify entanglement could be applied
to other types of photonic system and therefore may be useful for the
characterisation of a range of different nanophotonic quantum devices.Comment: 7 pages, 4 figure
Timing of moult in male and female shelducks <i>Tadorna tadorna</i>:Effects of androgens and mates
Timing of moult in male and female shelducks <i>Tadorna tadorna</i>:Effects of androgens and mates
Observation of quantum interference in the plasmonic Hong-Ou-Mandel effect
We report direct evidence of the bosonic nature of surface plasmon polaritons
(SPPs) in a scattering-based beamsplitter. A parametric down-conversion source
is used to produce two indistinguishable photons, each of which is converted
into a SPP on a metal-stripe waveguide and then made to interact through a
semi-transparent Bragg mirror. In this plasmonic analog of the Hong-Ou-Mandel
experiment, we measure a coincidence dip with a visibility of 72%, a key
signature that SPPs are bosons and that quantum interference is clearly
involved.Comment: 5 pages, 3 figure
Timing of moult in male and female shelducks <i>Tadorna tadorna</i>:Effects of androgens and mates
‘You have a child who will call you “mama” ’: understanding adolescent pregnancy in South Sudan
Learning SO(3) Equivariant Representations with Spherical CNNs
We address the problem of 3D rotation equivariance in convolutional neural
networks. 3D rotations have been a challenging nuisance in 3D classification
tasks requiring higher capacity and extended data augmentation in order to
tackle it. We model 3D data with multi-valued spherical functions and we
propose a novel spherical convolutional network that implements exact
convolutions on the sphere by realizing them in the spherical harmonic domain.
Resulting filters have local symmetry and are localized by enforcing smooth
spectra. We apply a novel pooling on the spectral domain and our operations are
independent of the underlying spherical resolution throughout the network. We
show that networks with much lower capacity and without requiring data
augmentation can exhibit performance comparable to the state of the art in
standard retrieval and classification benchmarks.Comment: Camera-ready. Accepted to ECCV'18 as oral presentatio
Emotional Modulation of Cognition in Recent Onset Schizophrenia
__Abstract__
The current thesis describes a number of important findings on the
interaction between emotion and cognition in male recent onset
schizophrenia patients. In healthy controls a general effect of
emotional expressions on sustained attention is that it improves
reaction time while accuracy decreased after negative, but not after
positive emotional expressions. Although recent onset schizophrenia
patients have a general attentional deficit, the effect of facial
expressions on sustained attention is the same as in healthy controls.
Furthermore, despite a general selective attention deficit, the
emotional Stroop effect is not statistically different between recent
onset schizophrenia patients and healthy controls. The literature on
emotional memory modulation in patients with schizophrenia shows
contradictory results with two-thirds of the tasks finding no
difference between patients with schizophrenia and healthy controls,
this can be explained in part by methodological differences.
Nevertheless, impaired emotional modulation of memory consolidation
and a deficit in unconsciously using emotional content to modulate
memory could underlie deficits in emotional memory modulation. In
recent onset schizophrenia patients emotional modulation is preserved,
both in short and long term memory and for both verbal and visual
memory. Social cognition, in the form of gaze cueing, however, is
already disturbed in the early phase of schizophrenia
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