924 resultados para bio-fuels
Resumo:
Cucurbit crops host a range of serious sap-sucking insect pests, including silverleaf whitefly (SLW) and aphids, which potentially represent considerable risk to the Australian horticulture industry. These pests are extremely polyphagous with a wide host range. Chemical control is made difficult due to resistance and pollution, and other side-effects are associated with insecticide use. Consequently, there is much interest in maximising the role of biological control in the management of these sap-sucking insect pests. This study aimed to evaluate companion cropping alongside cucurbit crops in a tropical setting as a means to increase the populations of beneficial insects and spiders so as to control the major sap-sucking insect pests. The Population of beneficial and harmful insects, with a focus on SLW and aphids, and other invertebrates were sampled weekly oil four different crops which could be used for habitat manipulation: Goodbug Mix (GBM; a proprietary seed Mixture including self-sowing annual and perennial herbaceous flower species); lablab (Lablab purpureus L. Sweet); lucerne (Medicago sativa L.); and niger (Guizotia abyssinica (L.f.) Cass.). Lablab hosted the highest numbers of beneficial insects (larvae and adults of lacewing (Mallada signata (Schneider)), ladybird beetles (Coccinella transversalis Fabricius) and spiders) while GBM hosted the highest numbers of European bees (Apis mellifera Linnaeus) and spiders. Lucerne and niger showed little promise in hosting beneficial insects, but lucerne hosted significantly more spiders (double the numbers) than niger. Lucerne hosted significantly more of the harmful insect species of aphids (Aphis gossypii (Glover)) and Myzus persicae (Sulzer)) and heliothis (Heliothis armigera Hubner). Niger hosted significantly more vegetable weevils (Listroderes difficillis (Germar)) than the other three species. Therefore, lablab and GBM appear to be viable options to grow within cucurbits or as field boundary crops to attract and increase beneficial insects and spiders for the control of sap-sucking insect pests. Use of these bio-control strategies affords the opportunity to minimise pesticide usage and the risks associated with pollution.
Resumo:
Sugarcane is a major global agricultural crop that produces significant quantities of sugar and biomass in tropical and sub-tropical regions. Over many centuries, the crop has been grown primarily for its high sugar content which traditionally contributes over 95% of the revenue derived from the crop. While the production of renewable electricity from bagasse and rum from molasses has a long history, in more recent decades significant advances have been made in the production of cogeneration products and fuel ethanol at large scale. Sugarcane biorefineries producing fuels, green chemicals, biopolymers and bio-products offer great potential for improving the profitability of sugarcane production. This paper will address the opportunities available for sugarcane biorefineries to contribute to future profitability and sustainability of the sugarcane industry.
Resumo:
Biorefineries, co-producing fuels, green chemicals and bio-products, offer great potential for enhancing agricultural value, and developing new industries in the bioeconomy. Biomass biorefineries aim to convert agricultural crops and wastes through biochemical and enzymatic processes to low cost fermentable sugars and other products which are platforms for value-adding. Through subsequent fermentation or chemical synthesis, the bio-based platforms can be converted to fuels including ethanol and butanol, oils, organic acids such as lactic and levulinic acid and polymer precursors. Other biorefinery products can include food and animal feeds, plastics, fibre products and resins. In 2014, QUT commissioned a study from Deloitte Access Economics and Correlli Consulting to assess the potential future economic value of tropical biorefineries to Queensland. This paper will report on the outcomes of this study and address the opportunities available for tropical biorefineries to contribute to the future profitability and sustainability of tropical agricultural industries in Queensland and more broadly across northern Australia.
Resumo:
We present a participatory modelling framework that integrates information from interviews and discussions with farmers and consultants, with dynamic bio-economic models to answer complex questions on the allocation of limited resources at the farm business level. Interviews and discussions with farmers were used to: describe the farm business; identify relevant research questions; identify potential solutions; and discuss and learn from the whole-farm simulations. The simulations are done using a whole-farm, multi-field configuration of APSIM (APSFarm). APSFarm results were validated against farmers' experience. Once the model was accepted by the participating farmers as a fair representation of their farm business, the model was used to explore changes in the tactical or strategic management of the farm and results were then discussed to identify feasible options for improvement. Here we describe the modelling framework and present an example of the application of integrative whole farm system tools to answer relevant questions from an irrigated farm business case study near Dalby (151.27E - 27.17S), Queensland, Australia. Results indicated that even though cotton crops generates more farm income per hectare a more diversified rotation with less cotton would be relatively more profitable, with no increase in risk, as a more cotton dominated traditional rotation. Results are discussed in terms of the benefits and constraints from developing and applying more integrative approaches to represent farm businesses and their management in participatory research projects with the aim of designing more profitable and sustainable irrigated farming systems.
Resumo:
Extractive components obtained from milling residues of white cypress were studied for chemical identity and bioactivity with a view to developing a commercial use for these components, thus increasing the value of the residues and improving the economics of cypress sawn wood production. Extracts obtained by solvent or steam extraction techniques from cypress sawdust were each fractionated by a range of techniques into groups of similar compounds. Crude extracts and fractions were screened against a range of agricultural pests and diseases, including two fungi, subterranean termites, fruit spotting bugs, two-spotted mites, thrips, heliothis, banana scab moths, silverleaf whiteflies, cattle tick adults and larvae, and ruminant gastrointestinal nematodes. Additional screening was undertaken where encouraging results were achieved, for two-spotted mites, thrips, silverleaf whiteflies, cattle tick adults and ruminant gastrointestinal nematodes. After considering degrees of efficacy against, and economic importance of, the agricultural pests, and likely production costs of extracts and fractions, the crude extract (oil) produced by steam distillation was chosen for further study against silverleaf whitefly. A useful degree of control was achievable when this oil was applied to tomato or eggplant at 0.1%, with much less harmful effects on a beneficial insect. Activity of the oil against silverleaf whitefly was undiminished 3.5 years after it was generated. There was little benefit from supplementing the extract with co-formulated paraffinic oil. From the steam distilled oil, fifty-five compounds were characterised, thirty-five compounds representing 92.478 % of the oil, with guaiol (20.8%) and citronellic acid (15.9%) most abundant. These two compounds, and a group of oxygenated compounds containing bulnesol and a range of eudesmols, were found to account for most of the activity against silverleaf whitefly. This application was recommended for first progression to commercialisation.
Resumo:
The study focuses on the potential roles of the brick making industries in Sudan in deforestation and greenhouse gas emission due to the consumption of biofuels. The results were based on the observation of 25 brick making industries from three administrative regions in Sudan namely, Khartoum, Kassala and Gezira. The methodological approach followed the procedures outlined by the Intergovernmental Panel on Climate Change (IPCC). For predicting a serious deforestation scenario, it was also assumed that all of wood use for this particular purpose is from unsustainable sources. The study revealed that the total annual quantity of fuelwood consumed by the surveyed brick making industries (25) was 2,381 t dm. Accordingly, the observed total potential deforested wood was 10,624 m3, in which the total deforested round wood was 3,664 m3 and deforested branches was 6,961 m3. The study observed that a total of 2,990 t biomass fuels (fuelwood and dung cake) consumed annually by the surveyed brick making industries for brick burning. Consequently, estimated total annual emissions of greenhouse gases were 4,832 t CO2, 21 t CH4, 184 t CO, 0.15 t N20, 5 t NOX and 3.5 t NO while the total carbon released in the atmosphere was 1,318 t. Altogether, the total annual greenhouse gases emissions from biomass fuels burning was 5,046 t; of which 4,104 t from fuelwood and 943 t from dung cake burning. According to the results, due to the consumption of fuelwood in the brick making industries (3,450 units) of Sudan, the amount of wood lost from the total growing stock of wood in forests and trees in Sudan annually would be 1,466,000 m3 encompassing 505,000 m3 round wood and 961,000 m3 branches annually. By considering all categories of biofuels (fuelwood and dung cake), it was estimated that, the total emissions from all the brick making industries of Sudan would be 663,000 t CO2, 2,900 t CH4, 25,300 t CO, 20 t N2O, 720 t NOX and 470 t NO per annum, while the total carbon released in the atmosphere would be 181,000 t annually.
Resumo:
A new method of calculating the calorific values of fossil fuels from their chemical composition has been developed, based on the concept that heats of reaction of stoichiometric fuel-oxidizer systems are rectilinearly related with the total oxidizing or reducing valancies of the mixture. The calorific value of fossil fuels has been shown to be directly related to the net reducing valencies of the fuel. The proposed method is simple and compares favourably with the other prominent methods reported in the literature.
Resumo:
There is an increased interest on the use of UAVs for environmental research such as tracking bush fires, volcanic eruptions, chemical accidents or pollution sources. The aim of this paper is to describe the theory and results of a bio-inspired plume tracking algorithm. A method for generating sparse plumes in a virtual environment was also developed. Results indicated the ability of the algorithms to track plumes in 2D and 3D. The system has been tested with hardware in the loop (HIL) simulations and in flight using a CO2 gas sensor mounted to a multi-rotor UAV. The UAV is controlled by the plume tracking algorithm running on the ground control station (GCS).
Resumo:
Physical and chemical properties of biofuels vary among various feedstocks and their subsequent conversions to fuels. The biofuels contain various amounts of oxygen, and this has a significant influence on exhaust emission. This oxygen content has been considered in order to investigate its effect on diesel engine exhaust emissions. The experiments have been conducted with a heavy duty diesel engine and various oxygenated fuels. It is found that the amount of oxygen in the fuel has a high level of influence on its exhaust emissions, and this provides agreement with diesel emissions results such as PN reduction. By increasing the amount of oxygen in the blend (by adding more biofuel), the particulate number (PN) is reduced and NOx increases gradually. However, the variation of PN and NOx are not similar for waste cooking biodiesel (WCBD) and butanol blend, even though their oxygen content are the same in the blends. This is due to the source of the biofuel and their internal chemistry.
Resumo:
A new class of compounds, viz., monothiocarbohydrazones, have been found to be hypergolic with anhydrous and red fuming nitric acids. A study of the ignition delays of the various thiocarbohydrazonenitric acid systems as a function of particle size and fuel/oxidizer ratio reveals no significant effect by these parameters. The observed ignition delays have been explained in terms of the chemical reactivity and structure of these compounds.
Resumo:
High-throughput techniques are necessary to efficiently screen potential lignocellulosic feedstocks for the production of renewable fuels, chemicals, and bio-based materials, thereby reducing experimental time and expense while supplanting tedious, destructive methods. The ratio of lignin syringyl (S) to guaiacyl (G) monomers has been routinely quantified as a way to probe biomass recalcitrance. Mid-infrared and Raman spectroscopy have been demonstrated to produce robust partial least squares models for the prediction of lignin S/G ratios in a diverse group of Acacia and eucalypt trees. The most accurate Raman model has now been used to predict the S/G ratio from 269 unknown Acacia and eucalypt feedstocks. This study demonstrates the application of a partial least squares model composed of Raman spectral data and lignin S/G ratios measured using pyrolysis/molecular beam mass spectrometry (pyMBMS) for the prediction of S/G ratios in an unknown data set. The predicted S/G ratios calculated by the model were averaged according to plant species, and the means were not found to differ from the pyMBMS ratios when evaluating the mean values of each method within the 95 % confidence interval. Pairwise comparisons within each data set were employed to assess statistical differences between each biomass species. While some pairwise appraisals failed to differentiate between species, Acacias, in both data sets, clearly display significant differences in their S/G composition which distinguish them from eucalypts. This research shows the power of using Raman spectroscopy to supplant tedious, destructive methods for the evaluation of the lignin S/G ratio of diverse plant biomass materials.
Resumo:
There has been much controversy over the Trans-Pacific Partnership (TPP) – a plurilateral trade agreement involving a dozen nations from throughout the Pacific Rim – and its impact upon the environment, biodiversity, and climate change. The secretive treaty negotiations involve Australia and New Zealand; countries from South East Asia such as Brunei Darussalam, Malaysia, Singapore, Vietnam, and Japan; the South American nations of Peru and Chile; and the members of the 1994 North American Free Trade Agreement (NAFTA), Canada, Mexico and the United States. There was an agreement reached between the parties in October 2015. The participants asserted: ‘We expect this historic agreement to promote economic growth, support higher-paying jobs; enhance innovation, productivity and competitiveness; raise living standards; reduce poverty in our countries; and to promote transparency, good governance, and strong labor and environmental protections.’ The final texts of the agreement were published in November 2015. There has been discussion as to whether other countries – such as Indonesia, the Philippines, and South Korea – will join the deal. There has been much debate about the impact of this proposed treaty upon intellectual property, the environment, biodiversity and climate change. There have been similar concerns about the Trans-Atlantic Trade and Investment Partnership (TTIP) – a proposed trade agreement between the United States and the European Union. In 2011, the United States Trade Representative developed a Green Paper on trade, conservation, and the environment in the context of the TPP. In its rhetoric, the United States Trade Representative has maintained that it has been pushing for strong, enforceable environmental standards in the TPP. In a key statement in 2014, the United States Trade Representative Mike Froman insisted: ‘The United States’ position on the environment in the Trans-Pacific Partnership negotiations is this: environmental stewardship is a core American value, and we will insist on a robust, fully enforceable environment chapter in the TPP or we will not come to agreement.’ The United States Trade Representative maintained: ‘Our proposals in the TPP are centered around the enforcement of environmental laws, including those implementing multilateral environmental agreements (MEAs) in TPP partner countries, and also around trailblazing, first-ever conservation proposals that will raise standards across the region’. Moreover, the United States Trade Representative asserted: ‘Furthermore, our proposals would enhance international cooperation and create new opportunities for public participation in environmental governance and enforcement.’ The United States Trade Representative has provided this public outline of the Environment Chapter of the TPP: A meaningful outcome on environment will ensure that the agreement appropriately addresses important trade and environment challenges and enhances the mutual supportiveness of trade and environment. The Trans-Pacific Partnership countries share the view that the environment text should include effective provisions on trade-related issues that would help to reinforce environmental protection and are discussing an effective institutional arrangement to oversee implementation and a specific cooperation framework for addressing capacity building needs. They also are discussing proposals on new issues, such as marine fisheries and other conservation issues, biodiversity, invasive alien species, climate change, and environmental goods and services. Mark Linscott, an assistant Trade Representative testified: ‘An environment chapter in the TPP should strengthen country commitments to enforce their environmental laws and regulations, including in areas related to ocean and fisheries governance, through the effective enforcement obligation subject to dispute settlement.’ Inside US Trade has commented: ‘While not initially expected to be among the most difficult areas, the environment chapter has emerged as a formidable challenge, partly due to disagreement over the United States proposal to make environmental obligations binding under the TPP dispute settlement mechanism’. Joshua Meltzer from the Brookings Institute contended that the trade agreement could be a boon for the protection of the environment in the Pacific Rim: Whether it is depleting fisheries, declining biodiversity or reduced space in the atmosphere for Greenhouse Gas emissions, the underlying issue is resource scarcity. And in a world where an additional 3 billion people are expected to enter the middle class over the next 15 years, countries need to find new and creative ways to cooperate in order to satisfy the legitimate needs of their population for growth and opportunity while using resources in a manner that is sustainable for current and future generations. The TPP parties already represent a diverse range of developed and developing countries. Should the TPP become a free trade agreement of the Asia-Pacific region, it will include the main developed and developing countries and will be a strong basis for building a global consensus on these trade and environmental issues. The TPP has been promoted by its proponents as a boon to the environment. The United States Trade Representative has maintained that the TPP will protect the environment: ‘The United States’ position on the environment in the TPP negotiations is this: environmental stewardship is a core American value, and we will insist on a robust, fully enforceable environment chapter in the TPP or we will not come to agreement.’ The United States Trade Representative discussed ‘Trade for a Greener World’ on World Environment Day. Andrew Robb, at the time the Australian Trade and Investment Minister, vowed that the TPP will contain safeguards for the protection of the environment. In November 2015, after the release of the TPP text, Rohan Patel, the Special Assistant to the President and Deputy Director of Intergovernmental Affairs, sought to defend the environmental credentials of the TPP. He contended that the deal had been supported by the Nature Conservancy, the International Fund for Animal Welfare, the Joint Ocean Commission Initiative, the World Wildlife Fund, and World Animal Protection. The United States Congress, though, has been conflicted by the United States Trade Representative’s arguments about the TPP and the environment. In 2012, members of the United States Congress - including Senator Ron Wyden (D-OR), Olympia Snowe (R-ME), and John Kerry (D-MA) – wrote a letter, arguing that the trade agreement needs to provide strong protection for the environment: ‘We believe that a '21st century agreement' must have an environment chapter that guarantees ongoing sustainable trade and creates jobs, and this is what American businesses and consumers want and expect also.’ The group stressed that ‘A binding and enforceable TPP environment chapter that stands up for American interests is critical to our support of the TPP’. The Congressional leaders maintained: ‘We believe the 2007 bipartisan congressional consensus on environmental provisions included in recent trade agreements should serve as the framework for the environment chapter of the TPP.’ In 2013, senior members of the Democratic leadership expressed their opposition to granting President Barack Obama a fast-track authority in respect of the TPP House of Representatives Minority Leader Nancy Pelosi said: ‘No on fast-track – Camp-Baucus – out of the question.’ Senator Majority leader Harry Reid commented: ‘I’m against Fast-Track: Everyone would be well-advised to push this right now.’ Senator Elizabeth Warren has been particularly critical of the process and the substance of the negotiations in the TPP: From what I hear, Wall Street, pharmaceuticals, telecom, big polluters and outsourcers are all salivating at the chance to rig the deal in the upcoming trade talks. So the question is, Why are the trade talks secret? You’ll love this answer. Boy, the things you learn on Capitol Hill. I actually have had supporters of the deal say to me ‘They have to be secret, because if the American people knew what was actually in them, they would be opposed. Think about that. Real people, people whose jobs are at stake, small-business owners who don’t want to compete with overseas companies that dump their waste in rivers and hire workers for a dollar a day—those people, people without an army of lobbyists—they would be opposed. I believe if people across this country would be opposed to a particular trade agreement, then maybe that trade agreement should not happen. The Finance Committee in the United States Congress deliberated over the Trans-Pacific Partnership negotiations in 2014. The new chair Ron Wyden has argued that there needs to be greater transparency in trade. Nonetheless, he has mooted the possibility of a ‘smart-track’ to reconcile the competing demands of the Obama Administration, and United States Congress. Wyden insisted: ‘The new breed of trade challenges spawned over the last generation must be addressed in imaginative new policies and locked into enforceable, ambitious, job-generating trade agreements.’ He emphasized that such agreements ‘must reflect the need for a free and open Internet, strong labor rights and environmental protections.’ Elder Democrat Sander Levin warned that the TPP failed to provide proper protection for the environment: The TPP parties are considering a different structure to protect the environment than the one adopted in the May 10 Agreement, which directly incorporated seven multilateral environmental agreements into the text of past trade agreements. While the form is less important than the substance, the TPP must provide an overall level of environmental protection that upholds and builds upon the May 10 standard, including fully enforceable obligations. But many of our trading partners are actively seeking to weaken the text to the point of falling short of that standard, including on key issues like conservation. Nonetheless, 2015, President Barack Obama was able to secure the overall support of the United States Congress for his ‘fast-track’ authority. This was made possible by the Republicans and dissident Democrats. Notably, Oregon Senator Ron Wyden switched sides, and was transformed from a critic of the TPP to an apologist for the TPP. For their part, green political parties and civil society organisations have been concerned about the secretive nature of the negotiations; and the substantive implications of the treaty for the environment. Environmental groups and climate advocates have been sceptical of the environmental claims made by the White House for the TPP. The Green Party of Aotearoa New Zealand, the Australian Greens and the Green Party of Canada have released a joint declaration on the TPP observing: ‘More than just another trade agreement, the TPP provisions could hinder access to safe, affordable medicines, weaken local content rules for media, stifle high-tech innovation, and even restrict the ability of future governments to legislate for the good of public health and the environment’. In the United States, civil society groups such as the Sierra Club, Public Citizen, WWF, the Friends of the Earth, the Rainforest Action Network and 350.org have raised concerns about the TPP and the environment. Allison Chin, President of the Sierra Club, complained about the lack of transparency, due process, and public participation in the TPP talks: ‘This is a stealth affront to the principles of our democracy.’ Maude Barlow’s The Council of Canadians has also been concerned about the TPP and environmental justice. New Zealand Sustainability Council executive director Simon Terry said the agreement showed ‘minimal real gains for nature’. A number of organisations have joined a grand coalition of civil society organisations, which are opposed to the grant of a fast-track. On the 15th January 2013, WikiLeaks released the draft Environment Chapter of the TPP - along with a report by the Chairs of the Environmental Working Group. Julian Assange, WikiLeaks' publisher, stated: ‘Today's WikiLeaks release shows that the public sweetener in the TPP is just media sugar water.’ He observed: ‘The fabled TPP environmental chapter turns out to be a toothless public relations exercise with no enforcement mechanism.’ This article provides a critical examination of the draft Environment Chapter of the TPP. The overall argument of the article is that the Environment Chapter of the TPP is an exercise in greenwashing – it is a public relations exercise by the United States Trade Representative, rather than a substantive regime for the protection of the environment in the Pacific Rim. Greenwashing has long been a problem in commerce, in which companies making misleading and deceptive claims about the environment. In his 2012 book, Greenwash: Big Brands and Carbon Scams, Guy Pearse considers the rise of green marketing and greenwashing. Government greenwashing is also a significant issue. In his book Storms of My Grandchildren, the climate scientist James Hansen raises his concerns about government greenwashing. Such a problem is apparent with the TPP – in which there was a gap between the assertions of the United States Government, and the reality of the agreement. This article contends that the TPP fails to meet the expectations created by President Barack Obama, the White House, and the United States Trade Representative about the environmental value of the agreement. First, this piece considers the relationship of the TPP to multilateral environmental treaties. Second, it explores whether the provisions in respect of the environment are enforceable. Third, this article examines the treatment of trade and biodiversity in the TPP. Fourth, this study considers the question of marine capture fisheries. Fifth, there is an evaluation of the cursory text in the TPP on conservation. Sixth, the article considers trade in environmental services under the TPP. Seventh, this article highlights the tensions between the TPP and substantive international climate action. It is submitted that the TPP undermines effective and meaningful government action and regulation in respect of climate change. The conclusion also highlights that a number of other chapters of the TPP will impact upon the protection of the environment – including the Investment Chapter, the Intellectual Property Chapter, the Technical Barriers to Trade Chapter, and the text on public procurement.
Resumo:
Ageing behaviour, leading to ballistic changes, has been studied as a function of oxidizer loading in polystyrene/ammonium perchlorate solid-propellants. The ageing studies were carried out at 100 °C in air. Change in burning rate decreased as the oxidizer loading increased from 75 to 80%. The change in thermal decomposition rates both at 230 and 260 °C also decreased as the oxidizer loading in the propellants increased. The shapes of the plots of the changes in burning rate and thermal decomposition rate (230 and 260 °C) at different storage times for different oxidizer-loaded propellants seem to be exactly similar. These results lead to the conclusion that the thermal decomposition of the propellant may be responsible for bringing about the ballistic changes during the ageing process. Infrared studies of the binder portion of the aged propellant indicate that peroxide formation takes place during the course of ageing and that peroxide formation for a particular storage time and temperature increases as the loading decreases.
Resumo:
S-Labeled nucleosides of E. coli tRNA and some of the derivatives of thionucleosides were separated on Bio-Gel P-2 and Sephadex G-10 columns employing buffers of low salt concentration and high pH.