417932 research outputs found
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Conversion of agricultural waste into stable biocrude using spinel oxide catalysts
No full textBiomass, the feedstock for biocrude and ultimately renewable diesel is a low energy density feedstock. The transport of this feedstock over long distance has been proven to be a major burden on the commercialisation of biorefining. Therefore, it has been generally accepted that biomass should be upgraded to biocrude (a relatively high energy density liquid) in close proximity to the biomass sources. The biocrude liquid would then be transported to a biorefinery. Biocrude contains large amounts of oxygen (generally up to 38 wt%) that is removed from the crude in the refining process. In this study, we have synthesised a range of spinel oxide based catalysts to remove oxygen from the biocrude during the catalytic fast pyrolysis. The activity of spinel oxide (MgB2O4 where B = Fe, Al, Cr, Ga, La, Y, In) catalysts were screened for the pyrolysis reaction. While all the tested spinel oxides deoxygenated the pyrolysis vapour, MgCr2O4 was found to be effective in terms of oxygen removal efficiency relative to the quantity of bio oil produced
Comparison of linear and GAB isotherms for estimating the shelf life of low moisture foods packaged in plastic films
No full textThe shelf life of dried onion flakes and sliced green beans packaged in a plastic film and stored at 30 °C/75% RH and 40 °C/90% RH was calculated using the GAB and the linear approximation of the isotherm to ascertain whether or not the simplified linear model can be used with confidence to predict shelf life. This is of particular relevance to those in industry who may want to predict shelf life but lack the software to make the relevant calculations based on the more complex GAB isotherm. The results indicated that predicting the shelf life of low moisture foods packaged in plastic films using the simplified linear model can be done with confidence. The GAB model predicted longer shelf lives than were achieved in practice, with the over-estimation ranging from 5.8% for onion flakes at 30 °C/75% RH to 17.5% for onion flakes at 40 °C/90% RH. The corresponding range for green beans was 11.9% and 13.9% respectively. For industrial purposes, use of the GAB model for shelf life predictions does not appear to be warranted as predictions using the linear model were closer to the actual measured shelf lives. More comparative trials accompanying the experimental work would be required to confirm the validity over a wide range of practical applications
A review of the water-related energy consumption of the food system in nexus studies
No full textThis study reviewed nexus researches, synthesize and discuss insights, methodological practices, and future outlook of water-related energy consumption assessment of the food system. For the first time, the study assessed: (i) the trends and drivers of water-related energy research in different countries, (ii) how water-related energy in the food system is being evaluated (objectives & scale, study dimension & analysis focus, and methods) and (iii) the significance of food-system water-related energy in comparison with other sectors. Of 686 nexus studies undertaken since 1990, 104 studies (15%) quantified water-related energy. Studies have generally broadened in scope through time. The USA, China, and Australia have conducted most studies representing 23%, 17%, 15% of total respectively. A few of the identified major drivers in these countries leading water-related energy assessment are: providing optimal solutions and avoiding problem-shifting, analyzing the challenges and opportunities to reduce water-related energy, and exploring the energy-saving benefits by saving water. Of the 104 water-related energy studies, 65 articles (∼60%) related to the food system, focussed on the agriculture phase for irrigation energy consumption. Existing nexus studies often ignored other phases such as food processing and cooking, which are more energy-intensive. Over 50% of studies used material flow analysis to evaluate water-related energy in the food system. Few of the nexus studies evaluated inter-regional flows or changes through time. Absence of a comprehensive study of the entire food system, and wide variations in study system boundary and definitions, make it difficult to compare sectoral significance. However, the order of sectoral water-related energy consumption (from highest to lowest) identified as industrial, residential, agriculture, and water and wastewater service. Our review demonstrates a tremendous opportunity and need for an overarching framework to enable systematic evaluation and benchmarking of water-related energy consumption of the food system
Therapeutic DNA Vaccine Against HPV16-Associated Cancer
No full textHuman papillomavirus (HPV) is a contagious cause of anogenital and oropharyngeal cancers developing from persistently infected and subsequently transformed basal keratinocytes of mucosal epithelium. DNA-based immunotherapy offers great potential for the treatment of persisting HPV infections and associated cancers. Preclinical testing of therapeutic DNA-based HPV-targeted immunotherapy requires robust animal models which mimic HPV-associated cancer disease in humans. Here we describe a detailed protocol of intradermal delivery of a therapeutic DNA vaccine and a grafting model of neoantigen expressing skin to evaluate vaccine efficacy against HPV16 mediated hyperproliferative epithelium in mice
Removal of lead and other toxic metals in heavily contaminated soil using biodegradable chelators: GLDA, citric acid and ascorbic acid
No full textIn this study, we investigated the level of contamination of agricultural soil near an old recycling lead smelter in Vietnam and proposed an effective treatment for the remediation of the soil. The analysis of soil samples using an ICP-MS method revealed that the soil in the area was heavily contaminated by heavy metals, especially lead (Pb) with concentrations in surface soil of >3000 μg g. High concentrations of metals, including Pb, copper (Cu) and zinc (Zn), were found in whole soil profile. The FE-EPMA and Laser-Raman spectrometer results suggested that iron minerals and carbon materials in the soil are the important hosts of the toxic metals. Subsequently, a series of washing experiment were performed on the soil using biodegradable chelators, including N, N-dicarboxymethyl glutamic acid tetrasodium salt (GLDA), ascorbic acid and citric acid. The results showed that the mixture of GLDA-ascorbic (100 mM: 100 mM) can be considered as a potential candidate for Pb and Zn removal, which removes approximately 90% of Pb and 70% of Zn. Meanwhile, a mixture of GLDA-citric would be preferred for Cu removal based on its greater extraction efficiency compared to other mixtures
The Global-DEP conceptual framework — research on dryland ecosystems to promote sustainability
No full textGiven the increasing speed and intensity of ongoing climate change and human interventions, more systematic research is needed to realize the Sustainable Development Goals in drylands. The current research status of drylands globally was reviewed together with a conceptual framework that included four key themes: (1) dryland social-ecological system dynamics and driving forces, (2) dryland social-ecological system structure and functions, (3) dryland ecosystem services and human well-being in a changing environment and society, and (4) ecosystem management and sustainable livelihoods in drylands. The themes and their linkages were then analysed to outline three research priorities under each theme. The resulting conceptual framework and research priorities were proposed as the agenda of a new scientific programme, the Global Dryland Ecosystem Programme (Global-DEP), which is intended to facilitate actionable interdisciplinary research on drylands. This framework could be useful for wider dryland research and help meet the needs of practitioners and policymakers in drylands
Predicting rice pesticide fate and transport following foliage application by an updated PCPF-1 model
No full textThe Pesticide Concentration in Paddy Field (PCPF-1) model has been successfully used to predict the fate and transport of granular pesticides applied to the paddy fields. However, it is not applicable for pesticides in foliar formulation while previous studies have reported that foliar application may increase the risks of rice pesticide contamination to the aquatic environment due to pesticide wash-off from rice foliage. In this study, we developed and added a foliar application module into the PCPF-1 model to improve its versatility regarding pesticide application methods. In addition, some processes of the original model such as photodegradation were simplified. The updated model was then validated with data from previous studies. Critical parameters of the model were calibrated using the Sequential Uncertainty Fitting version 2 (SUFI-2) algorithm. The calibrated model simulated pesticide dissipation trend and concentrations with moderate accuracy in the two paddy compartments including rice foliage and paddy water. The accuracy of the predicted soil concentrations could not be evaluated since no observed data were available. Although the p-factor and r-factor obtained using the SUFI2 algorithm indicated that the uncertainty encompassed in the predicted concentrations was rather high, the daily predicted pesticide concentrations in rice foliage and paddy water were satisfactory based on the NSE values (0.36–0.89). The updated PCPF-1 model is a flexible tool for the environmental risk assessment of pesticide losses and the evaluation of agricultural management practices for mitigating pesticide pollution associated with rice production
Microstructural evolution and mechanical properties of bulk and porous low-cost Ti–Mo–Fe alloys produced by powder metallurgy
No full textA series of low-cost Ti–10Mo-xFe (x = 1, 5, 9 wt%) alloys were fabricated using conventional press and sinter powder metallurgy to investigate the effect of Fe content on their phase stability, sintering response, microstructure and mechanical properties. Phase analyses indicated that all alloys were composed of α, β and intermetallic phases. However, Fe additions increased the proportion of β and intermetallic phases and reduced the propensity of the alloy system to form α phase during slow furnace cooling. Densification of the Ti–10Mo-xFe alloys was subjected to two contradicting effects; a strong sintering response caused by the fast diffusion rate of Fe atoms which promotes densification and formation of Kirkendall pores related to the fast diffusion rate of Fe atoms in conjunction with comparatively slower diffusion of Ti and Mo. Nonetheless, the porosity level of the alloys was less than that of the sintered CP-Ti. Depending on the content of α, β and intermetallic phases, the alloys exhibited varied mechanical properties. It was found that Ti–10Mo–5Fe presented the best combination of mechanical properties including the highest compressive strength (2392 MPa) and strain (43%) and low elastic modulus (91 GPa) superior to the corresponding ones for the commonly used CP-Ti and some other Ti-based alloys. Porous Ti–10Mo–5Fe alloy was also fabricated by addition of 30 and 60 vol% ammonium hydrogen carbonate (NHHCO) space holder which generated sintered scaffolds with 25% and 52% porosity, respectively, with an increased effective pore size at higher porosity. This reduced the compressive strengths to 649 MPa and 168 MPa and the elastic moduli to 34 GPa and 16 GPa, respectively. This study demonstrates that Ti–Mo–Fe alloys offer significant savings on raw materials compared to current commercial and many recently developed biomedical Ti alloys. It also shows that porous Ti–10Mo–5Fe scaffolds are promising for hard tissue engineering applications offering mechanical properties which closely match with the human bone and optimal pore sizes essential for bone ingrowth
A fragile existence: a transdisciplinary food systems research program cut short
No full textThis chapter starts with a brief background on the challenge of food and nutrition security and the promise of a food systems approach to address this challenge. It tells the story of the Global Change Institute (GCI) Food Systems Program. The chapter describes the GCI Food Systems Program, emphasizing outputs from the program, including some ongoing research and teaching activities. Unfortunately for food systems research, the Australian Research Council is strongly based on disciplinary categories and themes, and the Rural Industry Research and Development Corporations are based on agricultural commodities. While the GCI more generally, and Food Systems Program specifically, can be viewed as an internal (The University of Queensland) attempt to facilitate interdisciplinary and transdisciplinary research, this attempt required supporting institutional reform with external stakeholders, including external research funding organisations. The term “food systems” refers to a specific approach to addressing food and nutrition security, and it is gaining considerable support in international literature
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