1,618 research outputs found
Green Strategies of Powdery Mildew Control in Hop: From Organic Products to Nanoscale Carriers
[EN] Humulus lupulus L. is a long-lived, perennial, herbaceous, and dioecious climbing plant. The
foremost producers in the European Union are Germany, the Czech Republic, Poland, Slovenia, and
Spain. The Spanish cultivated area is concentrated in the province of León. Powdery mildew, caused
by Podosphaera macularis, menaces hop production and quality in all hop growing regions located in
the Northern hemisphere, colonizing leaves, petioles, inflorescences, and finally cones. In this work,
powdery mildew control was monitored, comparing nine fungicide strategies: five organics, two
integrated disease management (IDM)-based, with and without Nutragreen® nanoscale carrier, and
two conventional treatments (CON) with and without Nutragreen® nanoscale carrier. The organic
treatments were able to diminish P. macularis on leaves, but no effect was observed in cones. CON
treatments reduced the infection on leaves and cones and increased the cone quantity and quality.
Likewise, IDM-based treatments provided satisfactory results as they diminished powdery mildew
on leaves and cones. Finally, dose reduction using a Nutragreen® nanoscale carrier showed beneficial
effects in the control of powdery mildew compared to the commercial dose. Hence, the use of nanoscale
carries permits a 30% reduction in pesticide dose, which optimizes yield and hop quality, reduces risks
linked to pesticides, and aids in compliance with public and international policy demands.SIThe authors thank the hop field agricultural engineer, hop growers, field workers in charge of the hop farms, and laboratory technicians for their help and collaboration in the necessary tasks
Photoionized OVI absorbers toward the bright QSO HE 0515-4414
We report on detailed Monte Carlo inversion analysis of five OVI systems from
the spectrum of the bright quasar HE 0515-4414 (z_e = 1.71). The associated
system at z_a = 1.697 with the neutral hydrogen column density N(HI)= 4.4
10^{13} cm^{-2} shows pronounced absorption from highly ionized transitions of
CIII, CIV, NV, OVI, SiIV, and probably SVI. We found that only a power law type
ionizing spectrum (J_nu propto nu^{-1.5}) is consistent with the observed
sample of the line profiles, i.e. the system is definitely intrinsic. The
relative metal abundances give almost the solar pattern and the metallicity of
about 5 times solar. The system originates in a thin shell of the line-of-sight
thickness L <= 16 pc. Two OVI systems at z_a = 1.674 ([C/H] = -1.6) and 1.602
([O/H] = -1.1), arising in intervening halos, have linear sizes of L = 3-14 kpc
and 17 kpc, respectively. Absorption systems at z_a = 1.385 ([C/H] = -0.3, L =
1.7-2.5 kpc) and z_a = 1.667 ([C/H] = -0.5, L = 1 kpc) exhibit characteristics
very similar to that observed in metal-enriched high velocity clouds in the
Milky Way.These systems are probably embedded in extremely metal-poor halos
with [C/H] < -2.4 (z_a = 1.667) and [C/H] < -3.7 (z_a = 1.385). We also found
two additional extremely metal-poor Ly-alpha systems at z_a = 1.500 and 1.681
with, respectively, N(HI) = 1.7 10^{15} and 1.8 10^{15} cm^{-2} and [C/H] <
-4.0 and <-3.0, - an indication that the distribution of metals in the
metagalactic medium is utterly patchy. Our results show that the ionization
states in the analyzed OVI absorbers, ranging from z = 1.4 to 1.7, can be
maintained by photoionization only and that the fraction of the shock-heated
hot gas with temperature T > 10^5 K is negligible in these systems.Comment: 16 pages, including 11 PostScript figures. Accepted for publication
in A&
Four-Body Bound State Calculations in Three-Dimensional Approach
The four-body bound state with two-body interactions is formulated in
Three-Dimensional approach, a recently developed momentum space representation
which greatly simplifies the numerical calculations of few-body systems without
performing the partial wave decomposition. The obtained three-dimensional
Faddeev-Yakubovsky integral equations are solved with two-body potentials.
Results for four-body binding energies are in good agreement with achievements
of the other methods.Comment: 29 pages, 2 eps figures, 8 tables, REVTeX
State Dependent Effective Interaction for the Hyperspherical Formalism
The method of effective interaction, traditionally used in the framework of
an harmonic oscillator basis, is applied to the hyperspherical formalism of
few-body nuclei (A=3-6). The separation of the hyperradial part leads to a
state dependent effective potential. Undesirable features of the harmonic
oscillator approach associated with the introduction of a spurious confining
potential are avoided. It is shown that with the present method one obtains an
enormous improvement of the convergence of the hyperspherical harmonics series
in calculating ground state properties, excitation energies and transitions to
continuum states.Comment: LaTeX, 16 pages, 8 ps figure
Estimulantes espermáticos en la inseminación artificial porcina = Sperm stimulants in swine artificial insemination
P. 22-33Los estimulantes espermáticos, conocidos también como
potenciadores o aditivos seminales, son un grupo de sustancias,
clasificadas en cuatro categorías ( estimulantes de la
motilidad espermática, hormonas, enzimas y otras diversas),
que añadidas al semen en el momento previo a la inseminación
de las hembras mejoran la fertilidad y/o la prolificidad.
En el presente artículo expondremos nuestras últimas investigaciones
sobre un estimulante espermático porcino (EEP),
de tipo "combinado", aplicable a la optimación de los resultados
de la inseminación artificial porcina (IAP).S
Benchmark Test Calculation of a Four-Nucleon Bound State
In the past, several efficient methods have been developed to solve the
Schroedinger equation for four-nucleon bound states accurately. These are the
Faddeev-Yakubovsky, the coupled-rearrangement-channel Gaussian-basis
variational, the stochastic variational, the hyperspherical variational, the
Green's function Monte Carlo, the no-core shell model and the effective
interaction hyperspherical harmonic methods. In this article we compare the
energy eigenvalue results and some wave function properties using the realistic
AV8' NN interaction. The results of all schemes agree very well showing the
high accuracy of our present ability to calculate the four-nucleon bound state.Comment: 17 pages, 1 figure
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