1,610 research outputs found
Improving feed grains
Clearly, to encourage grain growers to focus their production systems towards feed grains, it is important to first identify the reasons for variation in the nutritional value of grains and then to develop rapid, cheap, and accurate methods of measuring these factors. The analytical methods should ideally be suitable for application either at the site of grain delivery from the farm or within the place of stockfeed manufacture. This will mean the nutritional value of the grain can be known before it is used. The rational marketing of feed grains could then be achieved, with the benefits from more efficient animal production being shared between the grain grower and animal producer.
Yellow lupins for the pig industry
There is no doubt that Yellow lupins are suitable as an ingredient in the diet of pigs from weaning through until slaughter. While no research has been conducted on feeding this variety to breeding stock, there is no reason to believe that it would not be a suitable source of energy and amino acids. Whether it will become a significant ingredient in pig diets will depend on its availability and price
Coronal heating by magnetohydrodynamic turbulence driven by reflected low-frequency waves
A candidate mechanism for the heating of the solar corona in open field line regions is described. The interaction of Alfvén waves, generated in the photosphere or chromosphere, with their reflections and the subsequent driving of quasi-two-dimensional MHD turbulence is considered. A nonlinear cascade drives fluctuations toward short wavelengths which are transverse to the mean field, thereby heating at rates insensitive to restrictive Alfvén timescales. A phenomenology is presented, providing estimates of achievable heating efficiency that are most favorable
Making automation pay - cost & throughput trade-offs in the manufacture of large composite components
The automation of complex manufacturing operations can provide significant savings over manual processes, and there remains much scope for increasing automation in the production of large scale structural composites. However the relationships between driving variables are complex, and the achievable throughput rate and corresponding cost for a given design are often not apparent. The deposition rate, number of machines required and unit production rates needed are interrelated and consequently the optimum unit cost is difficult to predict. A detailed study of the costs involved for a series of composite wing cover panels with different manufacturing requirements was undertaken. Panels were sized to account for manufacturing requirements and structural load requirements allowing both manual and automated lay-up procedures to influence design. It was discovered that the introduction of automated tape lay-up can significantly reduce material unit cost, and improve material utilisation, however higher production rates are needed to see this benefit
Pathways from uncertainty to anxiety: An evaluation of a hierarchical model of trait and disorder-specific intolerance of uncertainty on anxiety disorder symptoms
Uncertainty is central to anxiety-related pathology and intolerance of uncertainty (IU) appears to be a transdiagnostic risk and maintaining factor. The aim of the present study was to evaluate a hierarchical model to identify the unique contributions of trait and disorder-specific IU (i.e., uncertainty specific to generalised anxiety disorder, social anxiety, obsessive compulsive disorder, and panic disorder) to disorder-specific symptoms, beyond other disorder-specific cognitive vulnerabilities (i.e., negative metacognitive beliefs, fear of negative evaluation, inflated responsibility, and agoraphobic cognitions, respectively). Participants (N = 506) completed a battery of online questionnaires. Structural equation modelling was used to evaluate model fit, as well as direct and indirect pathways. Trait and disorder-specific IU were significantly associated with multiple cognitive vulnerability factors and disorder symptoms. Indirect effects between trait IU and symptoms were observed through disorder-specific IU and cognitive vulnerabilities. The relative contribution of trait IU and disorder-specific IU to symptoms varied and theoretical and clinical implications are highlighted. Limitations include the cross-sectional design and reliance on self-report. Avenues for further research include a need for replication and extension of the model in different samples and using experimental and multi-method research methods
From Solar and Stellar Flares to Coronal Heating: Theory and Observations of How Magnetic Reconnection Regulates Coronal Conditions
There is currently no explanation of why the corona has the temperature and
density it has. We present a model which explains how the dynamics of magnetic
reconnection regulates the conditions in the corona. A bifurcation in magnetic
reconnection at a critical state enforces an upper bound on the coronal
temperature for a given density. We present observational evidence from 107
flares in 37 sun-like stars that stellar coronae are near this critical state.
The model may be important to self-organized criticality models of the solar
corona.Comment: 13 pages, 2 figures, accepted to Ap. J. Lett., February 200
A reduced magnetohydrodynamic model of coronal heating in open magnetic regions driven by reflected low-frequency waves
A reduced magnetohydrodynamic (RMHD) description is employed to examine a suggestion made by W. H. Matthaeus and colleagues in 1999 that coronal heating might be sustained by a cascade of low-frequency MHD turbulence. Here RMHD simulations show that the low-frequency cascade to high transverse wavenumbers can be driven by an externally maintained flux of low-frequency propagating Alfvén waves, in combination with reflection caused by an inhomogeneous background medium. The simulations show that the suggestions made previously on the basis of a phenomenology are indeed realizable. In addition, the effect is seen to sensitively depend on the presence of reflection, as the background turbulence level needed to maintain the cascade can be sustained only when reflection is imposed. The steady level of turbulence is insensitive to the initial seed turbulence level (provided it is nonzero). Consequences of this model for realistic models of coronal heating in open field-line regions are discussed
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