Improving the nutritional management of non-astringent persimmon in subtropical Australia

A series of experiments was conducted to evaluate the nutritional requirements of non-astringent persimmon in subtropical Australia. Three rates two times of application of the two major nutrients, N and K, were evaluated for two different soil types in south-east Queensland. Nitrogen and K were shown to be key manipulators of productivity. At both low (100 kg per hectare) annual rates of N, the total number of fruit per tree was reduced due to adverse effects on fruit set and increased fruit drop. With potassium, average fruit weight and yield increased with increasing rates of K applied up to 80 kg per hectare, and much more slowly thereafter. Multiple, sequential foliar applications of Ca were shown to increase leaf Ca concentrations by 20%, improve fruit firmness and storage life. A benchmarking survey of leading orchards was also undertaken to document current nutritional practices, and to determine if there was a relationship between leaf nutrient concentrations with productivity. Salinity was a major problem in some production regions; and at leaf CI concentrations above 0.8%, yield was severely reduced. Based on these studies, a new, narrower range of leaf nutrient standards at both fruit set and one month prior to harvest is being developed

A Survey of Cultivars and Management Practices in Australian Persimmon Orchards

Three surveys were conducted to determine the most commonly used cultivars and management practices across Australia. The persimmon industry is established from the semi-tropical far north of Queensland to the cool temperate zones of Victoria, South Australia and Western Australia. Fruit from warmer regions mature four months earlier, giving a harvest spread from February to June inclusive. The majority of the Australian industry is based on the non-astringent cultivar Fuyu. Only 26% of Australian orchards are planted with pollinizers. Yield and fruit size vary within and between regions. Factors contributing to lower yields and smaller size grades are temperature, salinity, pollination, and training and management systems. The most common tree training system is the freestanding vase, followed by palmette, the V- and Tatura trellises. Ruakura trellis is the least used. Trellised trees produce higher yields of marketable fruit through increased planting density, improved light interception and a tree structure that stabilises against tree movement, significantly reducing fruit blemish

Extended Stromgren Photoelectric Photometry in NGC 752

Photoelectric photometry on the extended Stromgren system (uvbyCa) is presented for 7 giants and 21 main sequence stars in the old open cluster, NGC 752. Analysis of the hk data for the turnoff stars yields a new determination of the cluster mean metallicity. From 10 single-star members, [Fe/H] = -0.06 +/- 0.03, where the error quoted is the standard error of the mean and the Hyades abundance is set at [Fe/H] = +0.12. This result is unchanged if all 20 stars within the limits of the hk metallicity calibration are included. The derived [Fe/H] is in excellent agreement with past estimates using properly-zeroed m1 data, transformed moderate-dispersion spectroscopy, and recent high dispersion spectroscopy.Comment: 14 tex'd pages including 2 tables; 2 separate files with eps figures Accepted for PASP March 200

The 'Forbidden' Abundance of Oxygen in the Sun

We reexamine closely the solar photospheric line at 6300 A, which is attributed to a forbidden line of neutral oxygen, and is widely used in analyses of other late-type stars. We use a three-dimensional time-dependent hydrodynamical model solar atmosphere which has been tested successfully against observed granulation patterns and an array of absorption lines. We show that the solar line is a blend with a Ni I line, as previously suggested but oftentimes neglected. Thanks to accurate atomic data on the [O I] and Ni I lines we are able to derive an accurate oxygen abundance for the Sun: log epsilon (O) = 8.69 +/- 0.05 dex, a value at the lower end of the distribution of previously published abundances, but in good agreement with estimates for the local interstellar medium and hot stars in the solar neighborhood. We conclude by discussing the implication of the Ni I blend on oxygen abundances derived from the [O I] 6300 A line in disk and halo stars.Comment: 16 pages, 3 eps figures included; a more compact PostScript version created using emulateapj.sty is available from http://hebe.as.utexas.edu/recent_publi.html; to appear in ApJ

The [Y/Mg] clock works for evolved solar metallicity stars

Previously [Y/Mg] has been proven to be an age indicator for solar twins. Here, we investigate if this relation also holds for helium-core-burning stars of solar metallicity. High resolution and high signal-to-noise ratio (S/N) spectroscopic data of stars in the helium-core-burning phase have been obtained with the FIES spectrograph on the NOT 2.56m telescope and the HIRES spectrograph on the Keck I 10 m telescope. They have been analyzed to determine the chemical abundances of four open clusters with close to solar metallicity; NGC 6811, NGC 6819, M67 and NGC 188. The abundances are derived from equivalent widths of spectral lines using ATLAS9 model atmospheres with parameters determined from the excitation and ionization balance of Fe lines. Results from asteroseismology and binary studies were used as priors on the atmospheric parameters, where especially the $\log g$ is determined to much higher precision than what is possible with spectroscopy. It is confirmed that the four open clusters are close to solar metallicity and they follow the [Y/Mg] vs. age trend previously found for solar twins. The [Y/Mg] vs. age clock also works for giant stars in the helium-core burning phase, which vastly increases the possibilities to estimate the age of stars not only in the solar neighborhood, but in large parts of the Galaxy, due to the brighter nature of evolved stars compared to dwarfs.Comment: 5 pages, 3 figures, accepted for publication as a Letter to A&

Dynamic earthquake rupture modelled with an unstructured 3-D spectral element method applied to the 2011 M9 Tohoku earthquake

An important goal of computational seismology is to simulate dynamic earthquake rupture and strong ground motion in realistic models that include crustal heterogeneities and complex fault geometries. To accomplish this, we incorporate dynamic rupture modelling capabilities in a spectral element solver on unstructured meshes, the 3-D open source code SPECFEM3D, and employ state-of-the-art software for the generation of unstructured meshes of hexahedral elements. These tools provide high flexibility in representing fault systems with complex geometries, including faults with branches and non-planar faults. The domain size is extended with progressive mesh coarsening to maintain an accurate resolution of the static field. Our implementation of dynamic rupture does not affect the parallel scalability of the code. We verify our implementation by comparing our results to those of two finite element codes on benchmark problems including branched faults. Finally, we present a preliminary dynamic rupture model of the 2011 M_w 9.0 Tohoku earthquake including a non-planar plate interface with heterogeneous frictional properties and initial stresses. Our simulation reproduces qualitatively the depth-dependent frequency content of the source and the large slip close to the trench observed for this earthquake

Dynamic earthquake rupture modelled with an unstructured 3-D spectral element method applied to the 2011 M9 Tohoku earthquake

An important goal of computational seismology is to simulate dynamic earthquake rupture and strong ground motion in realistic models that include crustal heterogeneities and complex fault geometries. To accomplish this, we incorporate dynamic rupture modelling capabilities in a spectral element solver on unstructured meshes, the 3-D open source code SPECFEM3D, and employ state-of-the-art software for the generation of unstructured meshes of hexahedral elements. These tools provide high flexibility in representing fault systems with complex geometries, including faults with branches and non-planar faults. The domain size is extended with progressive mesh coarsening to maintain an accurate resolution of the static field. Our implementation of dynamic rupture does not affect the parallel scalability of the code. We verify our implementation by comparing our results to those of two finite element codes on benchmark problems including branched faults. Finally, we present a preliminary dynamic rupture model of the 2011 Mw 9.0 Tohoku earthquake including a non-planar plate interface with heterogeneous frictional properties and initial stresses. Our simulation reproduces qualitatively the depth-dependent frequency content of the source and the large slip close to the trench observed for this earthquak

The Indo-U.S. Library of Coude Feed Stellar Spectra

We have obtained spectra for 1273 stars using the 0.9m Coud\'e Feed telescope at Kitt Peak National Observatory. This telescope feeds the coud\'e spectrograph of the 2.1m telescope. The spectra have been obtained with the #5 camera of the coud\'e spectrograph and a Loral 3K X 1K CCD. Two gratings have been used to provide spectral coverage from 3460 \AA to 9464 \AA, at a resolution of $\sim$1\AA FWHM and at an original dispersion of 0.44 \AA/pixel. For 885 stars we have complete spectra over the entire 3460 \AA to 9464 \AA wavelength region (neglecting small gaps of $<$ 50 \AA), and partial spectral coverage for the remaining stars. The 1273 stars have been selected to provide broad coverage of the atmospheric parameters T$_{eff}$, log g, and [Fe/H], as well as spectral type. The goal of the project is to provide a comprehensive library of stellar spectra for use in the automated classification of stellar and galaxy spectra and in galaxy population synthesis. In this paper we discuss the characteristics of the spectral library, viz., details of the observations, data reduction procedures, and selection of stars. We also present a few illustrations of the quality and information available in the spectra. The first version of the complete spectral library is now publicly available from the National Optical Astronomy Observatory (NOAO) via FTP and HTTP.Comment: 18 pages, 6 figures, 4 table

Big Bang Nucleosynthesis Constraints on Hadronically and Electromagnetically Decaying Relic Neutral Particles

Big Bang nucleosynthesis in the presence of decaying relic neutral particles is examined in detail. All non-thermal processes important for the determination of light-element abundance yields of 2H, 3H, 3He, 4He, 6Li, and 7Li are coupled to the thermonuclear fusion reactions to obtain comparatively accurate results. Predicted light-element yields are compared to observationally inferred limits on primordial light-element abundances to infer constraints on the abundances and properties of relic decaying particles with decay times in the interval 0.01 sec < tau < 10^(12) sec. Decaying particles are typically constrained at early times by 4He or 2H, at intermediate times by 6Li, and at large times by the 3He/2H ratio. Constraints are shown for a large number of hadronic branching ratios and decaying particle masses and may be applied to constrain the evolution of the early Universe.Comment: 24 pages (revtex), 11 figures, title changed, matches published versio

Customer-engineer relationship management for converged ICT service companies

Thanks to the advent of converged communications services (often referred to as ‘triple play’), the next generation Service Engineer will need radically different skills, processes and tools from today’s counterpart. Why? in order to meet the challenges of installing and maintaining services based on multi-vendor software and hardware components in an IP-based network environment. The converged services environment is likely to be ‘smart’ and support flexible and dynamic interoperability between appliances and computing devices. These radical changes in the working environment will inevitably force managers to rethink the role of Service Engineers in relation to customer relationship management. This paper aims to identify requirements for an information system to support converged communications service engineers with regard to customer-engineer relationship management. Furthermore, an architecture for such a system is proposed and how it meets these requirements is discussed