School of Engineering and Energy

A decision support framework has been provided to assist investors with long-term decision-making for investment choices in power generation assets under uncertain climate policy. The model combines real options analysis and modern portfolio optimization theory. A long-term correlation between carbon and renewable portfolio standard certificate prices is used to model the interaction of climate policies, with a case study being developed to investigate the optimal choice of capacity additions to an existing mix of power generation assets in Australia. The findings show that there is potential for investors to fully hedge their existing fossil fuel based generation assets through the addition of on-shore wind capacity. The model developed allows for (1) the investigation of investment risk and return under uncertain climate policies, and (2) the study of interaction among green policies.

Nanostructured hydroxyapatite (HAP) was prepared by a wet precipitation method using Ca(NO 3) and KH 2 PO 4 as the main material and NH 3 as the precipitator under ultrasonic irradiation. The Ca/P ratio was set at 1.67 and the pH maintained at a minimum of 9. The temperature conditions and ultrasound influences were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR). The results showed that Nano-HAP can be obtained by this method and the particles were achieved to around 30 nm. Crown

A Carbon nano tube (CNT)–Ferrihydrite nanocomposite was synthesized through precipitation in ethyl alcohol media. Its detailed characterization was carried out using XRD, SEM, FTIR and EDAX. The adsorption characteristics of the composite for As(V) removal were carried out as function of pH, adsorbent dose, As(V) concentration and contact time. Although pure CNT did not show any significant adsorption, CNT-Ferrihydrite proved to be a good adsorbent for arsenic. With increase in pH, the As(V) adsorption on the composite first decreased up to pH 5.0, thereafter it remained nearly constant. The adsorption followed the Langmuir isotherm model and from the data its monolayer adsorption capacity was estimated to be 44.1 mg/g. The adsorption data were best described by the pseudo-second order kinetic model.

In this study, waste macadamia nut shells were investigated for potential use as a hard organic precursor for the production of a granular activated carbon material. The processing of the macadamia shells commenced with the carbonised of the shells under a nitrogen atmosphere. This was followed by the physical activation of the shells under a carbon dioxide atmosphere, which was carried out at different temperatures to investigate the effect of the activation temperature on pore formation. The pore structure and gold loading capacity of the synthesised activated carbons were investigated. The porous nature and surface structure of the macadamia shell based activated carbon were examined by Scanning Electron Microscopy (SEM) at various stages of manufacture. In addition, gold loading studies were carried out in conjunction with elemental mapping of the activated carbon surface to determine the gold adsorption sites. The studies have revealed that the macadamia shell based carbons, activated at higher temperatures have a gold loading capacity that is comparable to the commercially available coconut based activated carbons.

The removal of heavy metals such as cadmium from contaminated waterways and soils is a very important aspect of environmental remediation. This study investigated the kinetic and adsorption performance of a nanometre scale hydroxyapatite (HAP) synthesised from a combined ultrasound and microwave based technique for the removal of cadmium from an aqueous salt solution. Parameters such as contact time, initial pH, initial cadmium concentration and temperature were investigated. The Freundlich isotherm resulted in a more precise modelling of the communicated experimental data. Maximum monolayer adsorption capacity of absorber was found to be 123.45 mg/g at 298 K. Kinetic studies established cadmium adsorption tended to follow a pseudo-second order model and intra-particle diffusion played a significant role in determining the rate. Adsorption was endothermic, spontaneous and resulted in structural changes to the HAP matrix. The structural changes were investigated using both X-ray diffraction and field emission scanning electron microscopy.

A Carbon nano tube (CNT)-Ferrihydrite nanocomposite was synthesized through precipitation in ethyl alcohol media. Its detailed characterization was carried out using XRD, SEM, FTIR and EDAX. The adsorption characteristics of the composite for As(V) removal were carried out as function of pH, adsorbent dose, As(V) concentration and contact time. Although pure CNT did not show any significant adsorption, CNT-Ferrihydrite proved to be a good adsorbent for arsenic. With increase in pH, the As(V) adsorption on the composite first decreased up to pH 5.0, thereafter it remained nearly constant. The adsorption followed the Langmuir isotherm model and from the data its monolayer adsorption capacity was estimated to be 44.1 mg/g. The adsorption data were best described by the pseudo-second order kinetic model.

Cells respond to changes in the environment by altering their phenotype. The ability to influence cell behavior by modifying their environment provides an opportunity for therapeutic application, for example, to promote faster wound healing in response to skin injury. Here, we have modified the preparation of an aluminium oxide template to generate large uniform membranes with differing nano-pore sizes. Epidermal cells (keratinocytes) and dermal cells (fibroblasts) readily adhere to these nanoporous membranes. The pore size appears to influence the rate of cell proliferation and migration, important aspects of cell behavior during wound healing. The suitability of the membrane to act as a dressing after a burn injury was assessed in vivo; application of the membrane demonstrated adherence and conformability to the skin surface of a pig, with no observed degradation or detrimental effect on the repair. Our results suggest that keratinocytes are sensitive to changes in topography at the nanoscale level and that this property may be exploited to improve wound repair after tissue injury.

The influence of substrate's vibration during vacuum deposition of aluminium thin films on copper substrates was examined. Aluminium metal was evaporated in specially designed vacuum chamber using the hot-filament technique. Copper substrates were subjected to a vibration of 7.6 kHz during deposition. The Al coatings were identified using X-ray diffraction spectroscopy and scanning electron microscopy was used to examine the resulting microstructures deposited on the substrates. Coatings deposited under substrate vibration had fewer particles, spherical in shape and deposited over uniformly over the entire surface. This was not the case for the non-vibrated substrates, which tended to have much more densely packed granular shaped particles. The reflectivity experiments revealed that vibrated substrates were superior to the non-vibrated substrates by 28 %, while the difference in the thermal response was around 14 %.Read Complete Article at ijSciences: V3201406537

Biochar has been considered as a potential tool to mitigate soil ammonia (NH 3) volatilization and greenhouse gases (GHGs) emissions in recent years. However, the aging effect of biochar on soils remains elusive, which introduces uncertainty on the effectiveness of biochar to mitigate global warming in a long term. Here, a metaanalysis of 22 published works of literature with 217 observations was conducted to systematically explore the aging effect of biochar on soil NH 3 and GHGs emissions. The results show that, in comparison with the fresh biochar, the aging makes biochar more effective to decrease soil NH 3 volatilization by 7% and less risk to contribute CH 4 emissions by 11%. However, the mitigation effect of biochar on soil N 2 O emissions is decreased by 15% due to aging. Additionally, aging leads to a promotion effect on soil CO 2 emissions by 25% than fresh biochar. Our findings suggest that along with aging, particularly the effect of artificial aging, biochar could further benefit the alleviation of soil NH 3 volatilization, whereas its potential role to mitigate global warming may decrease. This study provides a systematic assessment of the aging effect of biochar to mitigate soil NH 3 and GHGs, which can provide a scientific basis for the sustainable green development of biochar application.

An in situ surface study of the carbon dioxide corrosion of mild steel has been undertaken using the tandem technique of mixed potential/synchrotron radiation-grazing incidence X-ray diffraction ͑SR-GIXRD͒. Long-term monitoring of the mixed potential showed there was an initial shift toward cathodic potentials attributable to preferential suppression of the cathodic half-reaction ͑viz., the reduction of carbonic acid͒, probably due to the formation of an adlayer of corrosion product physically blocking the cathodic reaction sites during the uniform corrosion of mild steel. Subsequently, the mixed potential displayed a gradual shift to anodic potentials, symbolizing the preferential suppression of the anodic half-reaction as the primary corrosion products ͓viz., Fe 2 ͑OH͒ 2 CO 3 , Fe 2 O 2 ͑CO 3 ͒, Fe 6 ͑OH͒ 12 ͑CO 3 ͒, and Fe 6 ͑OH͒ 12 ͑CO 3 ͒•2H 2 O͔ acquired a sufficient thickness to physically block the interface against further corrosion. Nevertheless, the corrosion product continues to grow over time, indicating that the corrosion product is discontinuous and porous, allowing the ingression of electrolyte to enable the further corrosion of the mild steel. This research has important ramifications for the field of corrosion research; it should enable researchers to develop improved methods of chemical inhibition by using compounds that can actually bind to the newly postulated corrosion products on mild steel.

Nanostructured hydroxyapatite (HAP) was prepared by a wet precipitation method using Ca(NO 3) and KH 2 PO 4 as the main material and NH 3 as the precipitator under ultrasonic irradiation. The Ca/P ratio was set at 1.67 and the pH maintained at a minimum of 9. The temperature conditions and ultrasound influences were investigated using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Fourier Transform Infrared Spectroscopy (FT-IR). The results showed that Nano-HAP can be obtained by this method and the particles were achieved to around 30nm.

A DNA vaccine, pCAG-HAk, expressing the full-length haemagglutinin (HA) gene of avian influenza A/Eurasian coot/Western Australia/2727/1979 (H6N2) virus, together with a Kozak sequence, in a pCAGGS vector was formulated with a novel nanoparticle, Phema. Two intramuscular immunizations of layer chickens at 3-week intervals with different doses of a nano-vaccine as well as 100µg pCAG-HAk failed to induce detectable haemagglutination-inhibition (HI) antibody. Following virus challenge, the pCAG-HAk vaccinated group did not show a statistically significant difference in frequency of virus shedding in both oropharyngeal and cloacal swabs from the naive control group. However, in comparison with the naive control group, the 100µg nano-vaccine group did significantly reduce virus shedding from the oropharynx. Despite lack of a dose-sparing effect from the nano-vaccine, there was a doseresponse effect. This pilot study indicated that Phema used as an adjuvant augmented the immune response induced by the pCAG-HAk construct.

Biochar has been considered as a potential tool to mitigate soil ammonia (NH3) volatilization and greenhouse gases (GHGs) emissions in recent years. However, the aging effect of biochar on soils remains elusive, which introduces uncertainty on the effectiveness of biochar to mitigate global warming in a long term. Here, a meta-analysis of 22 published works of literature with 217 observations was conducted to systematically explore the aging effect of biochar on soil NH3 and GHGs emissions. The results show that, in comparison with the fresh biochar, the aging makes biochar more effective to decrease soil NH3 volatilization by 7% and less risk to contribute CH4 emissions by 11%. However, the mitigation effect of biochar on soil N2O emissions is decreased by 15% due to aging. Additionally, aging leads to a promotion effect on soil CO2 emissions by 25% than fresh biochar. Our findings suggest that along with aging, particularly the effect of artificial aging, biochar could further benefit the alleviation of soil NH3 volatilization, whereas its potential role to mitigate global warming may decrease. This study provides a systematic assessment of the aging effect of biochar to mitigate soil NH3 and GHGs, which can provide a scientific basis for the sustainable green development of biochar application.

An in situ surface study of the carbon dioxide corrosion of mild steel has been undertaken using the tandem technique of mixed potential/synchrotron radiation-grazing incidence X-ray diffraction ͑SR-GIXRD͒. Long-term monitoring of the mixed potential showed there was an initial shift toward cathodic potentials attributable to preferential suppression of the cathodic half-reaction ͑viz., the reduction of carbonic acid͒, probably due to the formation of an adlayer of corrosion product physically blocking the cathodic reaction sites during the uniform corrosion of mild steel. Subsequently, the mixed potential displayed a gradual shift to anodic potentials, symbolizing the preferential suppression of the anodic half-reaction as the primary corrosion products ͓viz., Fe 2 ͑OH͒ 2 CO 3 , Fe 2 O 2 ͑CO 3 ͒, Fe 6 ͑OH͒ 12 ͑CO 3 ͒, and Fe 6 ͑OH͒ 12 ͑CO 3 ͒•2H 2 O͔ acquired a sufficient thickness to physically block the interface against further corrosion. Nevertheless, the corrosion product continues to grow over time, indicating that the corrosion product is discontinuous and porous, allowing the ingression of electrolyte to enable the further corrosion of the mild steel. This research has important ramifications for the field of corrosion research; it should enable researchers to develop improved methods of chemical inhibition by using compounds that can actually bind to the newly postulated corrosion products on mild steel.