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With the advent of more stringent legislation for fuel and fuel vapor emissions from vehicles, it has been necessary to introduce a barrier polymer into the fuel line as a means of reducing emissions. This paper investigates the changes in mechanical properties, such as tensile modulus, of a range of plasticized nylons, tie layer polymer systems and fluoropolymers which were immersed in various mixtures of fuel components and standard fuels at a temperature of 250C. The percentage mass uptake and extent of swelling were also determined in addition to changes in glass transition temperature up to a period of 31 weeks.

Bitumen, a mixture of aromatics, paraffins, asphaltenes and resins that remain after crude oil has been fractionally distilled, finds applications in blends with a proportion of a polymer, in built up membranes for the roofing industry. Blends of three commercially used polymers with a 100 penetration grade Nynas bitumen at levels between 9% and 29% w/w were prepared using a Z-blade mixer. The morphology, thermal and dynamic mechanical properties of these blends were examined using fluorescence optical microscopy, differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The blends prepared with these polymers displayed low temperature flexibility and an onset of flow at high temperatures. The former characteristic is required for use in cold environments the latter feature being a critical property when the membrane is manufactured and later when applied by the torching process on a roof. It may be seen how the different blends function in a manner that makes them suitable for the production of built-up roofing membranes.

As Metallocene Catalysed Polyethylenes (mPEs) become more commercially available they are finding ever increasing application in the blown film industry. However, it is becoming apparent that no two mPE resins behave in exactly the same manner. This paper examines the Theological properties of a range of mPEs with different densities and MFIs. These resins were then blended with a conventional low density polyethylene (LDPE) and extruded to form monolayer films. The mechanical properties of these films were compared to three layer coextruded films of A:B:A structure, where A is LDPE and B is mPE.

This is a report on the calibration tests and the determination of the response characteristics of a thrust anemometer designed to measure the three-dimensional instantaneous wind vector. Static tests determined the instrument calibration constants and checked the linearity of the system. Dynamic tests performed in a wind tunnel established that the ‘V2’ drag law applies to the sensing system. The wind-tunnel tests also determined the range of angles for which the anemometer was capable of resolving the vector wind. Finally, the amplitude and phase frequency response characteristics were measured. It was found that knowledge of the latter was important in studying turbulence spectra and cross spectra. Some preliminary results from a recent field program are presented which document the need for correcting the amplitude and phase responses.

The uses and shortcomings of duricrusts (ferricrete, calcrete and silcrete) in engineering construction (as used for road-base, aggregate, foundation materials and aquifers) are reviewed. Australian production of these materials represents about one-third of all unprocessed road-base and they are especially important as pavement courses for lightly trafficked, low-cost rural and outback roads. However, duricrusts are regarded as marginal materials at best because of their typically poor grading, particle unsoundness, high fines plasticity, and absorption of water and bitumen. These materials are used because they are available locally in areas that are otherwise lacking in hard rock materials, such as deeply weathered and sedimentary rock terrains. The weathering profiles of which they form part are characterized by high permeability (despite being clay-rich), variable cementation, low compressibility and a tendency to become weaker with depth. Although the more indurated layers are unrippable, they are also difficult to blast. Pedogenic (nodular) duricrusts were formerly sought for natural road-base, because they occur widely and require only rudimentary processing. However, well-cemented groundwater (vadose) duricrusts are now the preferred deposits, even though they require crushing and screening. Ferricrete is the most widely exploited of the duricrusts for engineering purposes, especially in northern and southwestern Australia, although calcrete is important in South Australia and in the Murray Basin. Silcrete is only a minor source of aggregate and road-base, mainly in western Queensland.

1. A 1H-n.m.r. method was used to measure concentrations of valine, alanine, lactate, acetate, hyaluronan and lipids in synovial fluid obtained, during the normal course of examination, from the knee joints of patients attending rheumatology and orthopaedic clinics. Fluid was available from 16 patients with osteoarthritis, 18 patients with rheumatoid arthritis, four patients with meniscal tear and one patient each with systemic lupus erythematosis, mono-arthritis, synovitis and loose bodies. Four normal specimens were obtained for comparison. 2. Valine, alanine and acetate levels all showed a normal Gaussian distribution, reflecting the distributions within the serum of the sample population. 3. Lactate concentrations divided into two distinct patterns. At concentrations below 2.5 mmol/l the lactate levels showed a Gaussian distribution, reflecting the distribution in normal serum. The normal synovial fluid specimens belong to this distribution. Above 2.5-3.0 mmol/l, lactate levels were asymmetric in distribution with a long tail at higher concentrations. These high levels of lactate can be explained by the generation of lactate through anaerobic metabolism within the synovial cavity. This metabolic process is triggered by a general inflammatory condition such as in rheumatoid arthritis. 4. The distribution of n.m.r.-observable lipid concentrations in rheumatoid arthritis and osteoarthritis each shows a normal distribution and the mean concentration is significantly higher in rheumatoid arthritis. 5. An increased n.m.r.-observable hyaluronan concentration is associated with an inflammatory situation. 6. It is concluded that raised levels of lactate and n.m.r.-observable hyaluronan and lipids are useful markers to aid the clinical distinction between rheumatoid arthritis and osteoarthritis. The results of this study confirm rheumatoid arthritis as an inflammatory disease inducing higher metabolic activity within the synovial cavity.