https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36365 Wed 29 Apr 2020 14:12:05 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51836 Wed 20 Sep 2023 16:11:03 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:14382 2S concentration in the sewer headspace with pre-corroded coupons experiencing more rapid decreases for a given H₂S concentration. Extensive corrosion of sound concrete has also been observed on pre-corroded samples over this period while minor losses are becoming apparent on new coupons. The combination of pH change, concrete losses and appearance of biological activity on the coupon surface all point to a rapid transition through an initial abiotic corrosion phase to the next stage in which corrosion is the result of neutrophilic microbial activity. A comparison of the early corrosion activity of new and pre-corroded coupons and anomalous readings at one high H2S location also indicate that the corrosion rate will most likely vary in a complex fashion over time and will be influenced by a variety of environmental factors in addition to H₂S levels. As more field data is collected and complementary laboratory and biological data become available a realistic, phenomenological model of this process will be developed allowing the service life of sewer pipes in Australia to be realistically predicted.]]> Wed 11 Apr 2018 13:07:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:21978 Wed 11 Apr 2018 10:27:58 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:9061 Wed 11 Apr 2018 09:26:00 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40821 Tue 19 Jul 2022 09:47:29 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43099 Tue 13 Sep 2022 12:40:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:18190 Sat 24 Mar 2018 08:04:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31025 2S) gas has been found to delay the appearance of many characteristics associated with senescence of horticultural produce but little attention has been given to its physiological role or its interaction with ethylene. This study used the green leafy vegetable, pak choy (Brassica rapa subsp. Chinensis) as the principal test commodity and examined the interaction of fumigation with hydrogen sulphide and storage at 10 °C in the presence of controlled levels of ethylene on endogenous ethylene production and a range of factors associated with postharvest deterioration. It was found that hydrogen sulphide inhibited ethylene production, chlorophyll loss, respiration, weight loss, various antioxidant factors and ion leakage. Hydrogen sulphide also inhibited chlorophyll loss and respiration of other green leafy vegetables/herbs, sweet Italian basil (Ocimum basilicum) and green curly kale (Brassica oleracea var. sabellica). The results suggest that the mode of action of hydrogen sulphide in delaying senescence could be by inhibiting both the production of ethylene and the action of ethylene. The substantial reduction in the rate of loss of chlorophyll following short-term treatment with hydrogen sulphide may have potential commercial benefit for extension in market life of green leafy vegetables.]]> Sat 24 Mar 2018 07:34:52 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23324 Sat 24 Mar 2018 07:13:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45516 2S) production and has been used to explore the mode of action of H₂S in prolonging storage of horticultural produce but little attention has been given to how PAG and H₂S interact when both are applied to produce. This study examined the effect of sequential application of PAG and H₂S on a range of postharvest senescence factors of the leafy vegetable pak choy (Brassica rapa subsp. Chinensis) stored at 10 °C. The results showed differential responses between factors when compared to application of PAG or H₂S alone. As expected, fumigation with H₂S reduced the rate of loss of leaf green colour, respiration rate, ethylene production, ion leakage and enhanced antioxidant activity and leaves sprayed with PAG showing converse effects. If PAG acted solely by inhibiting endogenous H₂S production then subsequent treatment with H₂S should fully negate any effect induced by PAG. However, for the combined PAG + H₂S treatment, respiration was similar leaves fumigated with H₂S, loss of green leaf colour was similar to the PAG single treatment and less than the untreated control, antioxidant activity was less than for PAG but greater than for control leaves, and ethylene production and ion leakage were similar to control leaves. Thus, the concept that PAG is exclusively an inhibitor of endogenous H₂S production was not validated, with PAG having effects on metabolism that are not linked to the action of endogenous H₂S. The additional actions of PAG could be through its inhibition of pyridoxyal-5′-phosphate (PHP) which is a coenzyme for numerous enzyme systems.]]> Mon 31 Oct 2022 13:48:56 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33610 Mon 23 Sep 2019 11:48:59 AEST ]]>