Fundacion Maquipucuna: an entrepreneurial Ecuadorian non-profit organisation

The purpose of this paper is to describe Fundacion Maquipucuna's community-based entrepreneurship activities. Fundacion Maquipucuna is a unique non-profit organisation in the Choco-Andes region of Ecuador. An ethnographic study and review of the literature is conducted to analyse the cacao, coffee, ecotourism and plastic thatch enterprises of Fundacion Maquipucuna. The enterprises Fundacion Maquipucuna is engaged in support the ongoing sustainability of the biodiverse ecological environment in the Choco-Andes region, which is one of the top five biodiverse hotspots in the world. On a global scale, more emphasis is being placed on promoting sustainability initiatives to preserve the environment. This paper discusses how a litre-government agency Fundacion Maquipucuna is changing from a non-profit to a for-profit structure in order to continue its community engagement projects. This paper integrates the social and community-based entrepreneurship literature to discuss how Fundacion Maquipucuna is engaging in innovative regional development that benefits the whole Choco-Andes community including the large Afro-Ecuadorian population.

Rapid composite tube manufacture utilizing the quickstep™ process

In this study, a novel method for manufacturing composite tubes utilizing the Quickstep^TM process has been developed. Tubes manufactured from `quick-cure' Toray G83C prepreg have demonstrated highly repeatable axial crush behavior with an average specific energy absorption (SEA) of 86 kJ/kg. The cure cycle is optimized by comparing the results from compression, dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and porosity testing. The tube lay-up is optimized using compression and porosity test results. The effect of changes in fiber-orientation on SEA is also investigated. Process development has resulted in a robust manufacturing method capable of producing fully cured, high performance composite tubes with a cure cycle of 7 min. This corresponds to a 95% reduction in time compared to an equivalent autoclave cycle.

Use of plastic and textile media in polishing primary treated effluent

The majority of on-site sewage management systems in Australia fail to perform to expectations. About 60% to 80% of on-site systems reportedly fail to produce acceptable effluent quality, and there is an increaed concern about the risks associated with public health and environmental pollution. In Victoria, a large proportion of septic tank installations have been reported to discharge highly polluted waste to drains and streams. Users, often considered by regulators as operators, have to bear the costs of upgrade/replacement of their old systems to meet stringent water quality guidelines. Some of the common problems include clogging of the disposal fields due to solids and organic overloading and surfacing of highly polluted effluent. Large land application area is subsequently required for irrigating the effluent and/or installation of upgraded disposal fields.
This paper investigates the effectiveness of various types of textile and plastic media, in polishing primary tank effluent, downstream from a typical two-compartment septic tank system. Results to date show that high biochemical oxygen demand removal rates are achieved from the textile and plastic media (up to 86% and 83% respectively). At these removal levels, the performance of a combined conventional septic tank system and plastic/textile filters is comparable to that of an advanced aerated wastewater treatment system. This approach, subject to further investigation, could provide a less costly upgrade.

Deformation behavior of nanostructured aluminum alloy processed by severe plastic deformation

Microstructure and deformation behavior of the commercial aluminum-based Al7.5%Zn–2.7%Mg–2.3%Cu–0.15%Zr alloy subjected to high pressure torsion (HPT) were studied in the present work. A small grain size less than 100 nm, high level of internal stresses and presence of second phase nanoparticles were revealed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The nanostructured alloy processed by HPT exhibits tensile strength of 800 MPa and ductility of 20% at optimal temperature-strain rate conditions. Unusual influence of a short pre-annealing on tensile strength and ductility of as-processed alloy is discussed.

A novel method of tube manufacture for vehicle crashworthiness utilising the QUICKSTEP™ Process.

A novel method of composite tube manufacture was developed for potential use in automotive crash structures. Tubes were crushed axially under quasi-static conditions and highly repeatable behaviour was observed with an average specific energy absorption of -85kJ/kg. DMTA results indicated that the tubes were fully cured, even when the cycle was reduced to 7 minutes, giving this process huge potential for high-volume production.

Plastic deformation in Zr41 Ti14 Cu12.5 Ni10 Be22.5 bulk metal glass under vickers indenter

Vickers indentation was conducted on an as-cast Zr41Ti14Cu12.5Ni10Be22.5 bulk metal glass (BMG) to study shear band formation using a bonded interface technique. The results indicate that the plastic deformation in the BMG is accommodated by the semi-circular (primary) and radial (secondary) shear bands. The inter-band spacing of the semi-circular shear bands is found to be independent of the applied load. The measured size of the deformation zone is in good agreement with the prediction of the theoretical model proposed by Zhang et al.

Determination of plastic yield stress from spherical indentation slope curve

The indentation slope curve from a spherical indentation on elastic-plastic materials is examined. By comparing it with that of an linear elastic material of the same elastic properties, we found that the start point of plastic yielding for an elastic-plastic material can be easily located from the indentation slope curve. Based on this analysis, a simple but effective method is proposed to measure the plastic yield stress of very small samples from a spherical nano-indentation slope curve.

Evaluating lubricants in sheet metal forming

The sheet metal forming process basically involves the shaping of sheet metal of various thickness and material properties into the desired contours. This metal forming process has been extensively used by the automotive industry to manufacture both car panels and parts. Over the years numerous investigations have been conducted on various aspects of the manufacturing process with varied success. In recent years the requirements on the sheet metal forming industry have headed towards improved stability in the forming process while lowering environmental burdens. Therefore the overall aim of this research was to identify a technique for developing lubricant formulations that are insensitive to the sheet metal forming process. Due to the expense of running experiments on production presses and to improve time efficiency of the process the evaluation procedure was required to be performed in a laboratory. Preliminary investigations in the friction/lubricant system identified several laboratory tests capable of measuring lubricant performance and their interaction with process variables. However, little was found on the correlation between laboratory tests and production performance of lubricants. Therefore the focus of the research switched to identifying links between the performance of lubricants in a production environment and laboratory tests. To reduce the influence of external parameters all significant process variables were identified and included in the correlation study to ensure that lubricant formulations could be desensitised to all significant variables. The significant process variables were found to be sensitive to die position, for instance: contact pressure, blank coating of the strips and surface roughness of the dies were found significant for the flat areas of the die while no variables affected friction when polished drawbeads were used. The next phase was to identify the interaction between the significant variables and the main lubricant ingredient groups. Only the fatty material ingredient group (responsible for the formation of boundary lubricant regimes) was found to significantly influence friction with no interaction between the ingredient groups. The influence of varying this ingredient group was then investigated in a production part and compared to laboratory results. The correlation between production performance and laboratory tests was found to be test dependant. With both the Flat Face Friction test and the Drawbead Simulator unaffected by changes in the lubricant formulation, while the Flat Bottom Cup test showing similar results as the production trial. It is believed that the lack of correlation between the friction tests and the production performance of the lubricant is due to the absence of bulk plastic deformation of the strip. For this reason the Ohio State University (OSU) friction test was incorporated in the lubricant evaluation procedure along with a Flat Bottom Cup test. Finally, it is strongly believed that if the lubricant evaluation procedure highlighted in this research is followed then lubricant formulations can be developed confidently in the laboratory.

Effect of structure relaxation on the plastic deformation behaviour in a Zr-based BMG under indenter

Vickers and nano indentations were performed on a structurally relaxed Zr₄₁Ti₁₄Cu_12.5Ni₁₀Be_22.5 bulk metallic glass (BMG), and the evolution of the shear bands in the relaxed BMG was investigated and compared to that in the as-cast alloy. Results indicate that the plastic deformation in the BMG with structure relaxation is accommodated by the semicircular (primary) and radial (secondary) as well as tertiary shear bands. Quantitatively, the shear band density in the relaxed alloy was much lower than that in the as-cast alloy. The annihilation of free volume caused by the annealing was responsible for the embrittlement of the sample with structure relaxation.

Plastic deformation in the annealed Zr41Ti14Cu12.5Ni10Be22.5 bulk metal glass under indenter

Vickers and nanoindentationswere carried out on an annealed Zr₄₁Ti₁₄Cu_12.5Ni₁₀Be_22.5 bulk metallic glass (BMG), and the evolution of the shear bands in the annealed BMG was investigated and compared to that in the as-cast alloy. Results indicate that the plastic deformation in the BMG with the structure relaxation is accommodated by the semicircular (primary) and radial (secondary) as well as tertiary shear bands. Quantitatively, the shear band density in the annealed alloywas much lower than that in the as-cast alloy. The load-displacement curve of nanoindentation test for the annealed alloy exhibited a more flat serrated flow. The annihilation of free volume caused by the annealing was responsible for the embrittlement of the annealed sample.

Plastic deformation in a partially crystallized Zr-based BMG under Vickers indenter

Vickers indentations were carried out on an anneal-introduced partially crystallized Zr₄₁Ti₁₄Cu_12.5 Ni₁₀Be_22.5 bulk metallic glass (BMG), and the evolution of the shear bands in this samplewas investigated and compared to the as-cast, aswell as the structurally relaxed counterparts. The results indicate that the plastic deformation in the partially crystallized BMG was accommodated by the semi-circular (primary) and radial (secondary) shear bands. A full crack or flake that was produced due to the spring back during the load removal was observed. The shear band density in the annealed alloy which was dispersed with crystalliteswas significantly lower than that of the as-cast alloy. The difference of the shear band features among the three kinds of alloy status, i.e., partially crystallized, structurally relaxed and as-cast alloys was discussed in terms of the free volume in the BMGs and the characteristics of nano-composites. It has been demonstrated that the plasticity for the three statuses of alloys queues in the descending order as the as-cast, annealed with partial crystallization, and annealed without crystallization.

Plastic flow properties and microstructural evolution in an ultrafine-grained Al-Mg-Si alloy at elevated temperatures

An AA6082 alloy was subjected to eight passes of equal channel angular pressing at 100 °C, resulting in an ultrafine grain size of 0.2 to 0.4 µm. The tensile deformation behavior of the material was studied over the temperature range of 100 °C to 350 °C and strain rate range of 10¯⁴ to 10¯¹ s¯¹. The evolution of microstructure under tensile deformation was investigated by analyzing both the deformation relief on the specimen surface and the dislocation structure. While extensive microshear banding was found at the lower temperatures of 100 °C to 150 °C, deformation at higher temperatures was characterized by cooperative grain boundary sliding and the development of a bimodal microstructure. Dislocation glide was identified as the main deformation mechanism within coarse grains, whereas no dislocation activity was apparent in the ultrafine grains.