Market prospects for rapeseed : 1972-73

Interest in rapeseed as an alternative crop in the agricultural region of Western Australia was reflected in the area sown in 1971, some 70,000 acres, and an initial export contract of 10,000 tons made in January 1972. This market report draws upon information released by the Department of Primary Industry and Department of Trade and Industry (both located in Canberra) and research within the Department of Agriculture. Its purpose is to outline future prospects for rapeseed as an aid to decision making for the 1972 season

Linseed production survey : Esperance, 1968

A SURVEY conducted after the 1967 linseed season found that although most farmers understood the requirements of linseed growing there were several crop failures. These were associated with time of planting, soil type and insect control measures. The Esperance district office of the Department of Agriculture conducted a second survey during December, 1968 and January, 196

Linseed : an alternative crop for the south coast

IN the over-17 inch rainfall zone of the south coast region of Western Australia animal production is the main farm enterprise. Although farmers in the main cereal growing regions of W.A. crop about one-third of their cleared land each year, farmers in the south have been reluctant to crop more than about 12 per cent, of their cleared area

Linseed : an alternative crop for the South Coast. 2. What is the future for linseed?

In a preceding article* we stated that the expansion of linseed in Western Australia was due primarily to the ability to sell on the export market at current ruling prices. This is necessary because Australia\u27s domestic needs are likely to be supplied in most years by Eastern States producers

Linseed : a forgotten crop

Linseed has become a forgotten crop in Western Australia. From a peak production of 6 200 tonnes from 12 500 hectares in 1969, and an apparently bright future, it dwindled to a bare 80 tonnes from 250 hectares in 1973. This article looks at some of the reasons for this decline and, with linseed fetching all-time record prices on world markets, gives reasons why the crop should be grown

Unique Thermal Properties of Clothing Materials.

Cloth wearing seems so natural that everyone is self-deemed knowledgeable and has some expert opinions about it. However, to clearly explain the physics involved, and hence to make predictions for clothing design or selection, it turns out to be quite challenging even for experts. Cloth is a multiphased, porous, and anisotropic material system and usually in multilayers. The human body acts as an internal heat source in a clothing situation, thus forming a temperature gradient between body and ambient. But unlike ordinary engineering heat transfer problems, the sign of this gradient often changes as the ambient temperature varies. The human body also perspires and the sweat evaporates, an effective body cooling process via phase change. To bring all the variables into analysis quickly escalates into a formidable task. This work attempts to unravel the problem from a physics perspective, focusing on a few rarely noticed yet critically important mechanisms involved so as to offer a clearer and more accurate depiction of the principles in clothing thermal comfort

Peristaltic Transport of a Rheological Fluid: Model for Movement of Food Bolus Through Esophagus

Fluid mechanical peristaltic transport through esophagus has been of concern in the paper. A mathematical model has been developed with an aim to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid. The model is formulated and analyzed with the specific aim of exploring some important information concerning the movement of food bolus through the esophagus. The analysis has been carried out by using lubrication theory. The study is particularly suitable for cases where the Reynolds number is small. The esophagus is treated as a circular tube through which the transport of food bolus takes places by periodic contraction of the esophageal wall. Variation of different variables concerned with the transport phenomena such as pressure, flow velocity, particle trajectory and reflux are investigated for a single wave as well as for a train of periodic peristaltic waves. Locally variable pressure is seen to be highly sensitive to the flow index `n'. The study clearly shows that continuous fluid transport for Newtonian/rheological fluids by wave train propagation is much more effective than widely spaced single wave propagation in the case of peristaltic movement of food bolus in the esophagus.Comment: Accepted for publication in Applied Mathematics and Mechanics (AMM), Springe

A combined study of heat and mass transfer in an infant incubator with an overhead screen

The main objective of this study is to investigate the major physical processes taking place inside an infant incubator, before and after modifications have been made to its interior chamber. The modification involves the addition of an overhead screen to decrease radiation heat losses from the infant placed inside the incubator. The present study investigates the effect of these modifications on the convective heat flux from the infant’s body to the surrounding environment inside the incubator. A combined analysis of airflow and heat transfer due to conduction, convection, radiation and evaporation has been performed, in order to calculate the temperature and velocity fields inside the incubator before and after the design modification. Due to the geometrical complexity of the model, Computer-Aided Design (CAD) applications were used to generate a computer-based model. All numerical calculations have been performed using the commercial Computational Fluid Dynamics (CFD) package FLUENT, together with in-house routines used for managing purposes and User-Defined Functions (UDFs) which extend the basic solver capabilities. Numerical calculations have been performed for three different air inlet temperatures: 32, 34 and 36ºC. The study shows a decrease of the radiative and convective heat losses when the overhead screen is present. The results obtained were numerically verified as well as compared with results available in the literature from investigations of dry heat losses from infant manikins