Search

Background and Aims: The sensory experience of wine aroma is challenging to study. Given the presence of numerous and trace level volatiles, the subtle aroma nuances involved, as well as the complexity of human odour processing, the contribution of individual compounds and mixtures can be difficult to determine. In white wines, the volatile compounds eliciting stone fruit aromas are not well understood. Methods and Results: Factorial designs were used with odorants added to model wine and assessed using sensory quantitative descriptive analysis. In model Viognier‐like wines, several monoterpenes were confirmed to convey stone fruit attributes Apricot and Peach, which were strongly suppressed by aldehydes which imparted Cardboard‐like odours. Importantly, lactones increased Apricot aroma when combined with the monoterpenes. For model unoaked Australian Chardonnay wine, sensory‐directed screening followed by factorial studies showed that aliphatic ethyl esters, in particular ethyl octanoate, directed Peach aroma. Fatty acids were strong suppressors of the Peach attribute and gave Cheesy odours. Conclusions: Apricot and peach aromas in Viognier and Chardonnay, although perceptually similar, were caused by different chemical compound families: grape‐derived monoterpenes with lactones and yeast‐derived fatty acid ethyl esters, respectively. Significance of the Study: Having confirmed the compounds responsible for apricot and peach white wine aromas, there is potential to modify their concentration through established viticultural and winemaking practices. [ABSTRACT FROM AUTHOR]

Transient gratings are an effective experimental method for investigating the kinetics in excited electronic dark states. The high sensitivity of transient grating technique with respect to the transient population gives a signal quality that allows the kinetics of vibrationally hot versus vibrational ground state mode to be differentiated.

Innovative designs of transport vehicles need to be validated in order to demonstrate reliability and provide confidence. The most common design approach of such structures involve simulations based on Finite Element (FE) analysis, which require reliable validation techniques, especially if anisotropic materials, such as fibre reinforced polymers, or complex designs, such as sandwich panels are to be considered. The present paper aims to integrate sophisticated numerical analysis with full-field optical measurement system data in order to improve the quality of both methods and increase reliability of the design.

Digital speckle correlation techniques have already been successfully proven to be an accurate displacement analysis tool for a wide range of applications. With the use of two cameras, three dimensional measurements of contours and displacements can be carried out. With a simple setup it opens a wide range of applications. Rapid new developments in the field of digital imaging and computer technology opens further applications for these measurement methods to high speed deformation and strain analysis, e.g. in the fields of material testing, fracture mechanics, advanced materials and component testing. The high resolution of the deformation measurements in space and time opens a wide range of applications for vibration analysis of objects. Since the system determines the absolute position and displacements of the object in space, it is capable of measuring high amplitudes and even objects with rigid body movements. The absolute resolution depends on the field of view and is scalable. Calibration of the optical setup is a crucial point which will be discussed in detail. Examples of the analysis of harmonic vibration and transient events from material research and industrial applications are presented. The results show typical features of the system.

We review basic metrological terms related to the use of measurement equipment for verification of numerical model calculations. We address three challenges that are faced when performing measurements in experimental mechanics with optical techniques: the calibration of a measuring instrument that (i) measures strain values, (ii) provides full-field data, and (iii) is dynamic.

Validation and calibration of optical full-field techniques that are used to measure strain and displacement in experimental mechanics is a prerequisite for validating numerical stress analyses. ICEM14 brings together practising engineers from around the world to exchange their experience regarding validation and calibration from everyday measurements with different optical techniques. The discussion addresses the following issues: (i) experience in calibrating measurement equipment based on imaging; (ii) reference measurements and calibration artefacts; (iii) validation of finite element analyses by comparison to experimental data; and (iv) uncertainties in full-field measurements.