Massey Documents by Type

Now showing 1 - 3 of 3

How does the application of ultrasound energy influence the ageing of a bottled red wine?
(Elsevier B.V., 2024-10-19) Duley G; Poggesi S; Longhi L; Longo E; Boselli E
A red wine that had aged in bottle for five years was treated with ultrasound (40 kHz) for 5 min and 30 min twice weekly and analysed after 3, 6, 9, and 12 months. Sensory analysis showed differences in overall quality at months 3 and 6, with the ultrasound-treated wines preferred. The ultrasound treatment did not decrease the free sulfur dioxide content. Differences in anthocyanins, polyphenols, and proanthocyanidins were clearest at month 9. In contrast, differences in the volatile profile were clearest at month 3. From a commercial point of view, the low-energy treatment (5 min) might be preferable given the lower costs. Ultrasound treatment was effective in enhancing the overall quality during the first 6 months of bottle storage in an aged red wine and did not increase the risk of oxidation or microbial spoilage. This work made it possible to fine-tune ultrasound treatment to maximise its positive effects.
'Smile for the camera' : a critical exploration of the meanings of routine ultrasound for pregnant couples : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Psychology at Massey University, Wellington, Aotearoa/New Zealand
(Massey University, 2012) Glen, Jessica Frances
There has been wide-spread research into the use of ultrasound in pregnancy with various participants and using different methodologies, however the field has been relatively under theorised. This research develops an integrated theoretical lens which provides an effective foundation to explore the increasing routinisation of ultrasound. With this approach it was possible to explore how seven pregnant heterosexual New Zealand couples drew on notions of visual primacy, the technological imperative and consumption and choice while working together to discursively construct what their experience with ultrasound service providers meant to them. This research was unique in its collaborative design of interviewing the pregnant woman and her partner together with their ultrasound images on hand to interact with. The couples (aged 25-40) undertook a joint semi-structured interview with the researcher in their homes, lasting between 45 to 90 minutes, which was digitally video- recorded and subsequently transcribed verbatim. They were invited to bring any images received as part of their ultrasound scan(s). The couples actively constructed certain aspects of their experience in particular ways. These included: 1) constructing the ultrasound as normal and commonsense; 2) constructing the pregnancy as legitimate and valid; 3) constructing the normality of the foetus; and 3) constructing the baby with personhood and gender. Understanding ultrasound as not just a normal, but a necessary site for the techno-visual birth of the foetus reinforced dominant biomedical understandings about what counts as real knowledge and positioned the pregnant couples as good parents-to-be, demonstrating their responsible consumption ‘choices’ on behalf of their – now visible and so viable – ‘unborn baby’. With the increasing routinisation of 2D ultrasound, and wider availability of 3D and 4D technology, these findings have implications for maternity care policy development in terms of women’s reproductive rights and pregnant couples’ (in)ability to make an informed decision about consent or refusal.
Use of ultrasound in enhancing productivity of biotechnological processes : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biochemical Engineering at Massey University, Palmerston North, New Zealand
(Massey University, 2011) Sulaiman, Ahmad Ziad Bin
This study focused on identifying optimum sonication regimens (e.g. intensity, duty cycles) that may intensify bioprocesses without damaging the biocatalyst. Possible mechanisms of productivity enhancement in various biotechnology processing scenarios were investigated. Three model processes were used: 1) production of bioethanol from lactose by fermentation with the yeast Kluyveromyces marxianus; 2) β-galactosidase catalyzed hydrolysis of lactose in a homogeneous cell-free system; and 3) hydrolysis of soluble and insoluble particulate cellulose of various sizes, catalyzed by soluble cellulase. The above processes involved: 1) conversion of a soluble substrate by a live catalyst in the presence of gas-liquid mass transfer; 2) a cell-free homogeneous bioreaction system; and 3) a heterogeneous reaction system involving substantial solid-liquid mass transfer limitations depending on the size of the substrate (i.e. soluble and insoluble particulate cellulose). Low intensity ultrasound (11.8 W cm⁻² sonication power at the sonotrode tip), enhanced the ethanol productivity of the batch fermentation process. At the specified sonication intensity a duty cycle of 20% was found to be optimal. A duty cycle of 40% adversely affected the fermentation. With the best duty cycle of 20%, the final ethanol concentration was 5.2±0.68 g L⁻¹, or nearly 3.5-fold that of the control fermentation. The productivity enhancing effect of sonication was attributed to a possible improved desorption of carbon dioxide from the fermentation broth. Ultrasound may also have facilitated transport of lactose into the cell by affecting cell permeability. While ultrasound apparently enhanced desorption of carbon dioxide, it also damaged yeast enzymes such as β-galactosidase and this may explain why a 40% duty cycle had an adverse impact on the fermentation. Although at the highest duty cycle of 40% sonication reduced cell growth, cell viability remained high at ≥70% during most of the fermentation. In continuous fermentations, sonication always enhanced the steady-state biomass concentration and ethanol concentration at all dilution rates tested relative to the corresponding controls. Ultrasound effectively influenced enzyme-substrate binding/unbinding for β- galactosidase mediated hydrolysis of lactose in a cell-free system. A short irradiation pulse (i.e. 10% duty cycle), applied at the highest irradiation power (11.8 W cm⁻²), Use of ultrasound in enhancing productivity of biotechnological processes improved the initial hydrolysis rate, by nearly 1.4-fold relative to control. This effect of ultrasound was possibly due to its accelerative effect on collision frequency of the enzyme and substrate molecules as a consequence of the microturbulence caused by sonication. The cellulase-mediated hydrolysis of soluble cellulose as well as particulate cellulose was enhanced by sonication at a 10% duty cycle and power intensity of 11.8 W cm⁻², but prolonged sonication adversely impacted the enzyme stability at a constant temperature of 50 °C relative to control.

Massey Documents by Type

Browse

Filters

Settings

Sort By

Results per page

Search Results