The microbiological and chemical composition of baled and precision-chop silages on a sample of farms in County Meath

peer-reviewedA Teagasc Walsh Fellowship awarded to J. McEniry supported this study.Baled and precision-chop silages were examined on a sample of farms in the Irish midlands to determine microbiological and chemical composition at feedout. Silage making practices and chemical composition were similar to those in national surveys. Wilting was an integral part of baled silage production and was reflected in a more restricted fermentation (higher pH and water-soluble carbohydrates, with lower fermentation acids and buffering capacity) compared to precision-chop silage. Yeast numbers were higher in baled silage, suggesting a more aerobic environment within the bale. Although the fermentation appeared similar in the outer and inner horizons of baled silage, yeast, lactic acid bacteria and Enterobacteria numbers were higher in the outer horizon suggesting less exacting anaerobiosis adjacent to the surface of the bale

Manipulating the ensilage of wilted, unchopped grass through the use of additive treatments

peer-reviewedBaled silage composition frequently differs from that of comparable conventional precision-chop silage. The lower final concentration of fermentation products in baled silage makes it more conducive to the activities of undesirable microorganisms. Silage additives can be used to encourage beneficial microbial activity and/or inhibit detrimental microbial activity. The experiment was organised in a 2 (chop treatments) × 6 (additive treatments) × 2 (stages of ensilage) factorial arrangement of treatments (n = 3 silos/treatment) to suggest additive treatments for use in baled silage production that would help create conditions more inhibitory to the activities of undesirable microorganisms and realise an outcome comparable to precision-chop silage. Chopping the herbage prior to ensiling, in the absence of an additive treatment, improved the silage fermentation. In the unchopped herbage, where the fermentation was poorer, the lactic acid bacterial inoculant resulted in an immediate increase (P < 0.001) in lactic acid concentration and a faster decline (P < 0.001) in pH with a subsequent reduction in butyric acid (P < 0.001) and ammonia-N (P < 0.01) concentrations. When sucrose was added in addition to the lactic acid bacterial inoculant, the combined treatment had a more pronounced effect on pH, butyric acid and ammonia-N values at the end of ensilage. The formic acid based additive and the antimicrobial mixture restricted the activities of undesirable microorganisms resulting in reduced concentrations of butyric acid (P < 0.001) and ammonia-N (P < 0.01). These additives offer a potential to create conditions in baled silage more inhibitory to the activities of undesirable microorganisms.A Teagasc Walsh Fellowship Research Scholarship awarded to J. McEniry supported this study

Time-dependent electron transport through a strongly correlated quantum dot: multiple-probe open boundary conditions approach

We present a time-dependent study of electron transport through a strongly correlated quantum dot. The time-dependent current is obtained with the multiple-probe battery method, while adiabatic lattice density functional theory in the Bethe ansatz local-density approximation to the Hubbard model describes the dot electronic structure. We show that for a certain range of voltages the quantum dot can be driven into a dynamical state characterized by regular current oscillations. This is a manifestation of a recently proposed dynamical picture of Coulomb blockade. Furthermore, we investigate how the various approximations to the electron-electron interaction affect the line-shapes of the Coulomb peaks and the I-V characteristics. We show that the presence of the derivative discontinuity in the approximate exchange-correlation potential leads to significantly different results compared to those obtained at the simpler Hartree level of description. In particular, a negative differential conductance (NDC) in the I-V characteristics is observed at large bias voltages and large Coulomb interaction strengths. We demonstrate that such NDC originates from the combined effect of electron-electron interaction in the dot and the finite bandwidth of the electrodes.Comment: 10 pages, 7 figure

Inelastic quantum transport: the self-consistent Born approximation and correlated electron-ion dynamics

A dynamical method for inelastic transport simulations in nanostructures is compared with a steady-state method based on non-equilibrium Green's functions. A simplified form of the dynamical method produces, in the steady state in the weak-coupling limit, effective self-energies analogous to those in the Born Approximation due to electron-phonon coupling. The two methods are then compared numerically on a resonant system consisting of a linear trimer weakly embedded between metal electrodes. This system exhibits enhanced heating at high biases and long phonon equilibration times. Despite the differences in their formulation, the static and dynamical methods capture local current-induced heating and inelastic corrections to the current with good agreement over a wide range of conditions, except in the limit of very high vibrational excitations, where differences begin to emerge.Comment: 12 pages, 7 figure

Technologies for restricting mould growth on baled silage

End of project reportSilage is made on approximately 86% of Irish farms, and 85% of these make some baled silage. Baled silage is particularly important as the primary silage making, storage and feeding system on many beef and smaller sized farms, but is also employed as a secondary system (often associated with facilitating grazing management during mid-summer) on many dairy and larger sized farms (O’Kiely et al., 2002). Previous surveys on farms indicated that the extent of visible fungal growth on baled silage was sometimes quite large, and could be a cause for concern. Whereas some improvements could come from applying existing knowledge and technologies, the circumstances surrounding the making and storage of baled silage suggested that environmental conditions within the bale differed from those in conventional silos, and that further knowledge was required in order to arrive at a secure set of recommendations for baled silage systems. This report deals with the final in a series (O’Kiely et al., 1999; O’Kiely et al., 2002) of three consecutive research projects investigating numerous aspect of the science and technology of baled silage. The success of each depended on extensive, integrated collaboration between the Teagasc research centres at Grange and Oak Park, and with University College Dublin. As the series progressed the multidisciplinary team needed to underpin the programme expanded, and this greatly improved the amount and detail of the research undertaken. The major objective of the project recorded in this report was to develop technologies to improve the “hygienic value” of baled silage

Tailoring negative pressure by crystal defects: Crack induced hydride formation in Al alloys

Climate change motivates the search for non-carbon-emitting energy generation and storage solutions. Metal hydrides show promising characteristics for this purpose. They can be further stabilized by tailoring the negative pressure of microstructural and structural defects. Using systematic ab initio and atomistic simulations, we demonstrate that an enhancement in the formation of hydrides at the negatively pressurized crack tip region is feasible by increasing the mechanical tensile load on the specimen. The theoretical predictions have been used to reassess and interpret atom probe tomography experiments for a high-strength 7XXX-aluminium alloy that show a substantial enhancement of hydrogen concentration at structural defects near a stress-corrosion crack tip. These results contain important implications for enhancing the capability of metals as H-storage materials.Comment: 22 pages, 9 figure

EVE: An Environment for On-board Processing

The Information Technology and Systems Center (ITSC) at The University of Alabama in Huntsville (UAH) is investigating and developing an innovative processing system capable of handling the unique constraints and characteristics of the on-board satellite data and information environment. The EnVironmEnt for On-Board Processing (EVE) system will serve as a proof-of-concept of advanced information systems technology for remote sensing platforms. EVE’s on-board, real-time processing will provide capabilities focused on the areas of autonomous data mining, classification and feature extraction. These will contribute to Earth Science research applications, including natural hazard detection and prediction, fusion of multi-sensor measurements, ntelligent sensor control, and the generation of customized data products for direct distribution to users. EVE is being engineered to provide high performance data processing in a real-time operational environment. A ground-based testbed is being created to provide testing of EVE and associated Earth Science applications in a heterogeneous embedded hardware and software environment

EVE: An Environment for On-board Processing

The Information Technology and Systems Center (ITSC) at The University of Alabama in Huntsville (UAH) is investigating and developing an innovative processing system capable of handling the unique constraints and characteristics of the on-board satellite data and information environment. The EnVironmEnt for On-Board Processing (EVE) system will serve as a proof-of-concept of advanced information systems technology for remote sensing platforms. EVE’s on-board, real-time processing will provide capabilities focused on the areas of autonomous data mining, classification and feature extraction. These will contribute to Earth Science research applications, including natural hazard detection and prediction, fusion of multi-sensor measurements, ntelligent sensor control, and the generation of customized data products for direct distribution to users. EVE is being engineered to provide high performance data processing in a real-time operational environment. A ground-based testbed is being created to provide testing of EVE and associated Earth Science applications in a heterogeneous embedded hardware and software environment