https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34580 Helicteres hirsuta Lour. (H. hirsuta L.) has been used as a traditional medicine for treatment of various ailments such as malaria and diabetes in Southeast Asian countries. This study aimed to optimize the conventional extraction conditions for obtaining the highest levels of phenolics, flavonoids, and antioxidant activities within H. hirsuta L. using response surface methodology. The Box–Behnken design was employed to evaluate the effects of extraction time, temperature, and the sample‐to‐solvent ratio on bioactive compound yield and antioxidant capacity of H. hirsuta L. The results indicated that the sample‐to‐solvent ratio had the strongest impact on bioactive compounds and antioxidant power of H. hirsuta L. and revealed the optimum extraction conditions to include temperature of 60 °C, time of 35 min at the sample‐to‐solvent ratio of 1 : 100 g/mL using 40% (v/v) methanol as the solvent. Under these conditions, the highest levels of total phenolic content and total flavonoid content were 16.87 mg GAE/g and 17.55 mg CE/g, respectively, significantly higher than the values obtained using water as the solvent. When preparing powered crude extract from H. hirsuta L., the ratio of 3 : 100 (g/mL) was suggested for the saving of 67% of solvent volume and energy required for solvent removal, as similar total phenolic content and total flavonoid content yield (86–87%) as well as antioxidant activities were obtained in comparison with the ratio of 1 : 100 (g/mL).]]> Wed 09 Feb 2022 15:55:50 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43312 Thu 15 Sep 2022 14:08:33 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44061 KL,SO2>KL,CO2. The fluxes of SO2 predicted from three methods were further compared with the experimental values measured in SO2-NaOH system. The fluxes predicted from KL,SO2 agreed well with the experimental values, whereas those from KL,CO2 and KL,O2 were significantly lower or higher. Therefore, the liquid-phase mass transfer coefficient is preferably obtained from the targeted gas. Modelling on the flux of SO2 demonstrates the transition of controlling regions against pH. At pH above 4, the gas side resistance is larger than the liquid side, whereas at pH below 4, the gas side resistance is smaller than the liquid side.]]> Thu 06 Oct 2022 10:19:26 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:7176 Sat 24 Mar 2018 08:34:17 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:12587 Sat 24 Mar 2018 08:18:42 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21392 Sat 24 Mar 2018 08:05:03 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18735 Sat 24 Mar 2018 08:02:46 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28256 Sat 24 Mar 2018 07:28:34 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44137 Sat 08 Oct 2022 12:43:41 AEDT ]]>