Mixed-species plantations of nitrogen-fixing and non-nitrogen-fixing trees

Mixed-species plantations of eucalypts and acacias have the potential to improve stand productivity over that of respective monocultures through the facilitative effect of nitrogen-fixation by acacias, and increased resource capture through above- and belowground stratification. However, growth in mixed-species plantations may not be improved compared to that of monocultures when competitive interactions outweigh the effects of improved nutrient availability and resource capture. Careful selection of sites and species is therefore critical to successfully improving stand productivity using mixed-species plantations. This study set out to examine some of the processes and interactions that occur in mixed-species plantations, and the effect nutrient and water availability can have on the growth of mixtures. ¶ In three out of four mixed-species field trials examined in this study, growth was not increased in mixtures compared to monocultures. However, in the fourth field trial, heights, diameters, stand volume and aboveground biomass were higher in mixtures of E. globulus and A. mearnsii from 3-4 years after planting. ¶ ..

St. Louis Exposition of 1904 and the Accountants\u27 Congress, Sept 26-28: their history revised for 2004

This two-day congress of accountants was held in September, 1904 during the St. Louis International Exposition. The importance of the congress for the federation of certified accountants across the United States is here confirmed. But the opportunities and intellectual challenges exposed at St. Louis, as at earlier European expositions, featured little for these pragmatic practitioners. More seriously for those claiming that an international accounting congress series began at St. Louis, an examination of its planning, agenda and participation reveals an Anglo-Saxon bias which was natural for that time. This bias was countered only by one Dutch accountant who arrived late - but who promoted the next international accounting congress twenty-four years later in Amsterdam. Thus evidence is here offered which contests claims that are still widely made, that international accounting was importantly initiated at St. Louis . Rather St. Louis was a specially American event to be understood in relation and contrast to European accountancy, expositions, competitions and congresses

Whether Molcolm\u27s is best or old charge and discharge

In 1775 A.D. the recommendation was made that the accounts of Glasgow College be changed from the traditional charge and discharge type of records to a double entry bookkeeping system. This touched off an academic controversy that lasted for many years and generated much bitterness among the Faculty of the College

The characterisation and cetane number determination of synthetic diesel fuels

South African synthetic fuel plants produce large quantities of lower alkenes which can be catalytically oligomerized to liquid transportation fuels. In the screening of experimental catalysts for the production of diesel-range fuels, it is important to measure the quality, as well as the quantity, of the fuel being produced. Cetane number is an important indicator of the quality of a diesel fuel ru1d is measured by a standard engine test (ASTM D 613) which requires l litre of fuel and is therefore not suitable for the routine testing of the small volumes of fuel produced by experimental catalysts. Alternative cetane number prediction methods exist but these have generally been developed to predict the cetane number of crude-oil based fuels and are therefore not suitable for use with synthetically derived fuels. This thesis details the development of a formula which accurately predicts the cetane number of a fuel from other, easily measured parameters. Several samples of fuel were produced under varying reaction conditions and were hydrogenated to ensure that they were virtually 100% alkane. Differences in cetane number should therefore be due to differences in the degree of branching. By measuring the cetane number on a. standard test engine and correlating the result with the amount of branching as measured by ¹Hnmr, a formula was developed which was found to accurately predict the cetane number of these types of synthetic fuels. The results obtained also show that for the conversion of ethene over a supported nickel catalyst, cetane number decreases as temperature increases. This decrease is probably caused by secondary butane oligomerization reactions

Note of sadness

Obituaries for William Paton, Michael J. Mepham, and Orace Johnson

Letter to the editor: Collaboration with French historians; Collaboration with French historians

May I use your hospitable columns to try to amend an injustice, and to encourage your readers to look wide for precedent in their researches? The problem arose through the editing of my Academy Working Paper No. 64. The replacement of the entire Preface by an Abstract had consequences which may be judged as readers of the Working Paper were given no clues as to the scholarly and collaborative French tradition which I tried to translate for them rather than to report new research by myself

Engineering design applications of surrogate-assisted optimization techniques

The construction of models aimed at learning the behaviour of a system whose responses to inputs are expensive to measure is a branch of statistical science that has been around for a very long time. Geostatistics has pioneered a drive over the last half century towards a better understanding of the accuracy of such ‘surrogate’ models of the expensive function. Of particular interest to us here are some of the even more recent advances related to exploiting such formulations in an optimization context. While the classic goal of the modelling process has been to achieve a uniform prediction accuracy across the domain, an economical optimization process may aim to bias the distribution of the learning budget towards promising basins of attraction. This can only happen, of course, at the expense of the global exploration of the space and thus finding the best balance may be viewed as an optimization problem in itself. We examine here a selection of the state of-the-art solutions to this type of balancing exercise through the prism of several simple, illustrative problems, followed by two ‘real world’ applications: the design of a regional airliner wing and the multi-objective search for a low environmental impact hous

Synthesizing Normalized Faces from Facial Identity Features

We present a method for synthesizing a frontal, neutral-expression image of a person's face given an input face photograph. This is achieved by learning to generate facial landmarks and textures from features extracted from a facial-recognition network. Unlike previous approaches, our encoding feature vector is largely invariant to lighting, pose, and facial expression. Exploiting this invariance, we train our decoder network using only frontal, neutral-expression photographs. Since these photographs are well aligned, we can decompose them into a sparse set of landmark points and aligned texture maps. The decoder then predicts landmarks and textures independently and combines them using a differentiable image warping operation. The resulting images can be used for a number of applications, such as analyzing facial attributes, exposure and white balance adjustment, or creating a 3-D avatar

A comparison between theoretical prediction and experimental measurement of the dynamic behavior of spur gears

A comparison was made between computer model predictions of gear dynamics behavior and experimental results. The experimental data were derived from the NASA gear noise rig, which was used to record dynamic tooth loads and vibration. The experimental results were compared with predictions from the DSTO Aeronautical Research Laboratory's gear dynamics code for a matrix of 28 load speed points. At high torque the peak dynamic load predictions agree with the experimental results with an average error of 5 percent in the speed range 800 to 6000 rpm. Tooth separation (or bounce), which was observed in the experimental data for light torque, high speed conditions, was simulated by the computer model. The model was also successful in simulating the degree of load sharing between gear teeth in the multiple tooth contact region