Correlating Sensory Assessment of Smoke-Tainted Wines with Inter-Laboratory Study Consensus Values for Volatile Phenols

Vineyard exposure to wildfire smoke can taint grapes and wine. To understand the impact of this taint, it is imperative that the analytical methods used are accurate and precise. This study compared the variance across nine commercial and research laboratories following quantitative analysis of the same set of smoke-tainted wines. In parallel, correlations between the interlaboratory consensus values for smoke-taint markers and sensory analyses of the same smoke-tainted wines were evaluated. For free guaiacol, the mean accuracy was 94 ± 11% in model wine, while the free cresols and 4-methylguaiacol showed a negative bias and/or decreased precision relative to guaiacol. Similar trends were observed in smoke-tainted wines, with the cresols and glycosidically bound markers demonstrating high variance. Collectively, the interlaboratory results show that data from a single laboratory can be used quantitatively to understand smoke-taint. Results from different laboratories, however, should not be directly compared due to the high variance between study participants. Correlations between consensus compositional data and sensory evaluations suggest the risk of perceivable smoke-taint can be predicted from free cresol concentrations, overcoming limitations associated with the occurrence of some volatile phenols, guaiacol in particular, as natural constituents of some grape cultivars and of the oak used for barrel maturation.     

Effect of trace elements on carbon microparticle formation

Laser vapourisation cluster beam experiments have been carried out to probe the way in which the presence of elements such as O, H, Fe etc. affect the mechanism of carbon microparticle formation. Studies with oxygen and hydrogen are designed to probe the intermediates involved in combustion processes and preliminary experiments with iron are aimed at a study of the characteristic clustering behaviour that occurs in steels. In this work a new carbon oxide C₆₀O, oxobuckminsterfullerene, has been identified.     

Multicolored trees in random graphs

We discuss the existence of multi-colored trees in randomly colored, random graphs. © 1994 John Wiley & Sons, Inc.     

A new portable sound processor for the University of Melbourne/Nucleus Limited multielectrode cochlear implant.

A new processor, called the spectral maxima sound processor (SMSP), has been developed for the University of Melbourne/Nucleus Limited multielectrode cochlear implant. The SMSP analyses sound signals by means of a bandpass filterbank having 16 channels which are allocated tonotopically to the implanted electrodes. Every 4 ms, typically, the six channels with the largest amplitudes are selected, and six corresponding electrodes are activated. In an ongoing study the performance of the SMSP is being compared with that of the Mini Speech Processor (MSP). Some results of speech perception tests from the first two SMSP users are presented, in which scores for the recognition of vowels, consonants, and words all showed significant increases over the corresponding MSP scores.     

Linear Programming Applications on Microcomputers

Linear programming is normally thought of as an application to be run on large computers, and for many problems that is the case. However, there are many problems of a suitable size to run on microcomputers, and a variety of packages have appeared on the market in the last year or two claiming to solve linear programming problems on popular microcomputers. The paper considers the features to look for in a package and the type of problem to consider for solution on microcomputers.     

Evaluation of methods for the assay of neptunium and other long-lived actinides in environmental matrices

Inductively coupled plasma mass spectrometry (ICP-MS) and neutron activation analysis (NAA) have been investigated as alternatives to alpha-spectrometry for the low-level determination of²³⁷Np and other actinides in environmental matrices. ICP-MS in particular, has been shown here to offer suitable sensitivity, precision and accuracy compared to the other techniques, with considerably faster sample throughput relative to radiometric and activation approaches. Added advantages of ICP-MS are found to include the abilities to determine other long-lived actinides simultaneously and to quantify²³⁹Pu:²⁴⁰Pu ratios. The neutron activation analysis approach was found to be particularly prone to interference especially from uranium nuclides.