Induced Chern-Simons terms

We examine the claim that the effective action of four-dimensional SU(2)_L gauge theory at high and low temperature contains a three-dimensional Chern-Simons term with coefficient being the chemical potential for baryon number. We perform calculations in a two-dimensional toy model and find that the existence of the term is rather subtle.Comment: 12 pages, LaTe

Modelling of a poultry shed

Tegel Foods is New Zealand’s leading producer and supplier of poultry products, providing an extensive range of quality poultry products to New Zealanders for over thirty years. Tegel is a fully-integrated poultry producer involved in breeding, hatching, feeding, growing, processing and marketing of chicken and turkey in New Zealand. The problem presented by Tegel was specifically to model the energy exchange between the chickens and their shed environment in order to better understand and control the shed climate and thereby maximize growth rate. A model for the heat production and water respiration rate of a typical chicken was developed, based on physical principles. A thermodynamical model of the whole chicken+shed system included the temperature of the external air, the internal air, the chickens, the litter, the concrete floor and the underlying soil. It also included the relative humidity (RH) of the external and internal air and the water flows into and out of the shed. Modelling of the shed environment’s inputs and outputs will be particularly valuable for continuing assessment of three fundamental inputs of economic importance: feed nutrient density in terms of energy formulation, heating in terms of gas/power usage, and heat removal via extraction fans. Optimisation of liveweight gain and feed conversion potential are the end targets

Determining temperature control of wash water in a laundry environment

Fisher and Paykel (F&P) are developing a new model of washing machine. One of its key features will be that it uses less water. It is important to regulate the operating temperature of washing machines since if they operate hotter than the user-selected temperature there is a risk of damage to clothes and if they operate below the user-selected temperature there is a risk of incompletely dissolved detergent being sprayed onto clothes, which is also undesirable. F&P seek to improve their temperature regulation strategies from the current state-of-the-art. Further, since the new machine will have a smaller mass of water relative to clothes load, the impact of abnormal clothes loads and of start-up disturbances in water supply temperatures (e.g. cold slugs in hot water supply) on the bulk temperature is greater. Thus a thorough review of temperature regulation strategies is well motivated

The shelf life of wine

The aim of this project was to investigate and develop models for the shelf life of bottled wine and, in particular, the effects of elevated temperatures to the ageing process. The problem was divided into three sub-problems. First, calculations were made to describe the temperature of wine in a single bottle when subjected to an elevated external temperature, and then this was extended to pallets of cartons of wine. Second, equations were derived for the gas flow through the cork when a wine bottle is subject to oscillatory external temperatures, as is common in a domestic storage situation. Third, the temperature dependent reaction rates of the wine ageing process were considered and calculations performed on how elevated decrease shelf life. Suggestions were made as to relatively simple experiments that can be performed to test the models presented here

Ramond-Ramond Couplings on Brane-Antibrane Systems

Couplings between a closed string RR field and open strings are calculated in a system of coincident branes and antibranes of type II theory. The result can be written cleanly using the curvature of the superconnection.Comment: Latex, 9 pages. Ver2: exposition clarifie

Large N and the Dine-Rajaraman problem

We compute the effective action for scattering of three well-separated extremal brane solutions, in 11d supergravity, with zero p_ transfer and small transverse velocities. Using an interpretation of the conjecture of Maldacena, following Hyun, this can be viewed as the large N limit of the Matrix theory description of three supergraviton scattering at leading order. The result is consistent with the perturbative supergravity calculation.Comment: 10 pages, tex (harvmac

Numerical study of stability and connectivity of vertical goaf drainage holes

During underground longwall coal extraction, overburden strata deformation may result in vertical goaf drainage holes, which are drilled in advance of mining for tail gate gas management, to fail. The performance of these vertical goaf drainage holes is controlled by mine design parameters and local geomechanical properties. This paper investigates the use of advanced 3D finite element modelling and 2D discrete element modelling simulation techniques to understand the fundamentals of vertical goaf drainage hole failure mechanism due to strata shear at a currently operating gassy Australian mine site. Finite element modelling is used to investigate the location of high shear in the overburden strata at the vertical goaf gas drainage hole region during longwall mining and the discrete element modelling is used to examine connectivity from the goaf region to the goaf-gas drainage system.The Anglo-American Metallurgical Coal, Australiahttp://link.springer.com/journal/107062022-01-02hj2021Mining Engineerin

Geometrical Finiteness, Holography, and the BTZ Black Hole

We show how a theorem of Sullivan provides a precise mathematical statement of a 3d holographic principle, that is, the hyperbolic structure of a certain class of 3d manifolds is completely determined in terms of the corresponding Teichmuller space of the boundary. We explore the consequences of this theorem in the context of the Euclidean BTZ black hole in three dimensions.Comment: 6 pages, Latex, Version to appear in Physical Review Letter