194 research outputs found
Ascorbic acid, carotenoid contents and antioxidant properties of Australian summer carrot with different irrigation amounts on a free-draining, sandy soil
It is important to reduce the use of water for agricultural production in response to water scarcity and environmental concerns. The nutritive value in fruits and vegetables including carrot (Daucus carota L.), can be influenced by various climatic conditions, such as light intensity, temperature, and irrigation. The effect of differential irrigation treatments on the contents of ascorbic acid and carotenoid as well as antioxidant properties (antioxidant content, antiradical power, and antioxidant capacity) were studied in carrot (cv. Stefano) roots grown on a free-draining, sandy soil (Grey Karrakatta Sand) in the summer period. This soil has water holding capacities as low as 10-13% and requires irrigation up to 150% of class A pan evaporation (Epan) to optimize growth and quality. The irrigation treatments applied in this study consisted of 100% Epan replacement, 150% Epan replacement and crop factor. The soil water stress index calculation showed the soil water tension ranged from -2.4 to -7.6 kPa that was within the range between saturation and field capacity for sandy soil. The reduction of irrigation amount from 150% to 100% Epan did not differentiate the contents of ascorbic acid and total carotenoid, but it slightly decreased antioxidant properties of carrot grown in the free draining sandy soil
Minimum Decision Cost for Quantum Ensembles
For a given ensemble of independent and identically prepared particles,
we calculate the binary decision costs of different strategies for measurement
of polarised spin 1/2 particles. The result proves that, for any given values
of the prior probabilities and any number of constituent particles, the cost
for a combined measurement is always less than or equal to that for any
combination of separate measurements upon sub-ensembles. The Bayes cost, which
is that associated with the optimal strategy (i.e., a combined measurement) is
obtained in a simple closed form.Comment: 11 pages, uses RevTe
Reactions of a Be-10 beam on proton and deuteron targets
The extraction of detailed nuclear structure information from transfer
reactions requires reliable, well-normalized data as well as optical potentials
and a theoretical framework demonstrated to work well in the relevant mass and
beam energy ranges. It is rare that the theoretical ingredients can be tested
well for exotic nuclei owing to the paucity of data. The halo nucleus Be-11 has
been examined through the 10Be(d,p) reaction in inverse kinematics at
equivalent deuteron energies of 12,15,18, and 21.4 MeV. Elastic scattering of
Be-10 on protons was used to select optical potentials for the analysis of the
transfer data. Additionally, data from the elastic and inelastic scattering of
Be-10 on deuterons was used to fit optical potentials at the four measured
energies. Transfers to the two bound states and the first resonance in Be-11
were analyzed using the Finite Range ADiabatic Wave Approximation (FR-ADWA).
Consistent values of the spectroscopic factor of both the ground and first
excited states were extracted from the four measurements, with average values
of 0.71(5) and 0.62(4) respectively. The calculations for transfer to the first
resonance were found to be sensitive to the size of the energy bin used and
therefore could not be used to extract a spectroscopic factor.Comment: 16 Pages, 10 figure
Evidence for Planet-induced Chromospheric Activity on HD 179949
We have detected the synchronous enhancement of Ca II H & K emission with the
short-period planetary orbit in HD 179949. High-resolution spectra taken on
three observing runs extending more than a year show the enhancement coincides
with phi ~ 0 (the sub-planetary point) of the 3.093-day orbit with the effect
persisting for more than 100 orbits. The synchronous enhancement is consistent
with planet-induced chromospheric heating by magnetic rather than tidal
interaction. Something which can only be confirmed by further observations.
Independent observations are needed to determine whether the stellar rotation
is sychronous with the planet's orbit. Of the five 51 Peg-type systems
monitored, HD 179949 shows the greatest chromospheric H & K activity. Three
others show significant nightly variations but the lack of any phase coherence
prevents us saying whether the activity is induced by the planet. Our two
standards, tau Ceti and the Sun, show no such nightly variations.Comment: 10 pages, 6 figures. Submitted to Ap
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