Does firefighting foam affect the growth of some Australian native plants?

Firefighting foams (Class A foams) are an effective and widespread firefighting tool, and are frequently used in environmentally sensitive areas. They are known to be ecologically damaging in aquatic environments; however, their impacts at the plant species or ecosystem level are relatively unknown. Reports of shoot damage to plants, suppressed flowering and changes in plant community composition suggest that the environmental damage caused by their use may be unacceptable. Applications of four levels of foam to seedlings of seven Australian plant species, from five representative and widespread families, showed no detectable impacts on a range of vegetative growth characteristics. The results are encouraging for continued use of firefighting foam in sensitive natural habitats.

Compressibility of porous magnesium foam: dependency on porosity and pore size

Mechanical properties of porous magnesium with the porosity of 35–55% and the pore size of about 70–400 μm are investigated by compressive tests focusing on the effects of the porosity and pore size on the Young's modulus and strength. Results indicated that the Young's modulus and peak stress increase with decreasing porosity and pore size. The mechanical properties of the porous magnesium were in a range of those of cancellous bone. Therefore, it is suggested that the porous magnesium is one of promising scaffold materials for hard tissue regeneration.

Does application of firefighting foam affect soil invertebrates?

Firefighting foam (Class A foam) is an effective and widespread frrefighting tool often used in environmentally sensitive areas. Although, firefighting foam is known to be ecologically damaging to aquatic invertebrates, application of 1.0% foam to heathland soils showed no detectable impacts on soil invertebrate orders sampled over several months. The results are encouraging for the continued use of Class A foam as a fire suppression technique in areas with high conservation value.

Novel titanium foam for bone tissue engineering

Titanium foams fabricated by a new powder metallurgical process have bimodal pore distribution architecture (i.e., macropores and micropores), mimicking natural bone. The mechanical properties of the titanium foam with low relative densities of approximately 0.20-0.30 are close to those of human cancellous bone. Also, mechanical properties of the titanium foams with high relative densities of approximately 0.50-0.65 are close to those of human cortical bone. Furthermore, titanium foams exhibit good ability to form a bonelike apatite layer throughout the foams after pretreatment with a simple thermochemical process and then immersion in a simulated body fluid. The present study illustrates the feasibility of using the titanium foams as implant materials in bone tissue engineering applications, highlighting their excellent biomechanical properties and bioactivity.

Crushing simulation of foam-filled aluminium tubes

A numerical study is presented in this paper to investigate the energy absorption of foam-filled aluminium tubes during crushing. The post-buckling mode of the foam-tube structures has been successfully simulated. The predicted compressive load-displacement is in a good agreement with experimental results. The energy absorption ability of the composite structure due to plastic deformation in a crushing process is evaluated by comparison with the tube structure without foam. The results indicate that the energy absorption of a foam-filled tube structure is superior to the tube without foam. The influences of the friction and the geometric parameters of the structure on the energy absorption have also been investigated. Results from this study will assist automotive industry to design crashworthy components based on foam-filled tubes.

Energy absorption and crushing behaviour of foam-filled aluminium tubes

The crushing behaviour and energy absorption of foam filled aluminium tubular structures were investigated using the quasi-static compressive tests. The crushing behaviour of the tubular structures changed due to foam filling. The energy absorption of the foam filled tubular structures was improved significantly. Foam filling caused an interaction effect between the tube and the foam during progressive crushing, leading to an increase in the mean crushing load compared to that of the foam or tube itself. This interaction effect might be affected by several parameters such as the density of the foam, the properties of both the foam material and tube material, and the thickness and outer diameter of the tube. In particular, the interaction effect essentially depended on the ratio of the mean crushing force of the foam to that of the tube.

Surviving suppression : no detectable impacts of Class A foam on soil invertebrates and some Australian native plants

Firefighting foams (Class A foams) are an effective and widespread firefighting tool which are frequently used in environmentally sensitive areas. Firefighting foams are known to be ecologically damaging in aquatic environments, however their impacts at the plant species or ecosystem level are relatively unknown. Reports of shoot damage to plants, suppressed flowering, and changes in plant community composition suggested that the ecological damage caused by their use may be unacceptable. However, applications of foam to seedlings of some Australian plant species from representative and widespread families, showed no detectable impacts on a range of vegetative growth characteristics. Application of 1.0% foam to heathland soils showed no detectable impacts on soil invertebrate Orders sampled over several months. The results are encouraging for the continued use of Class A foam as a fire suppression technique.

Simulation of three-point bending test of titanium foam for biomedical applications

Using Titanium (Ti) foam as an implant material is a new approach for biomedical applications and it is important to understand the mechanical behaviors of this new foam material. In the present study, the bending of the Ti foam has been simulated and compared against recently published data [1]. FE Analysis has been performed by Abaqus software. Stiffness and Yield strength of foams between 50% (cortical bone) to 80% (cancellous bone) porosity range were considered. This study showed that crushable foam material model in Abaqus, which has developed primarily for Aluminum (Al) foam alloys, is also valid for Ti Foam before any crack or damage occurs in the sample.

Mechanical properties of titanium foam for biomedical applications

Understanding the mechanical behaviour of pure titanium (Ti) foam is crucial for the design and development of Ti foam-based load-bearing implants. In this work, pure titanium foam is fabricated by a powder metallurgical process using the space-holder technique with a spacer size of 500 to 800 µm. Experimental data from static compression testing on the Ti foam are presented. The application of theoretical formulae to predict Young's modulus and yield strength of titanium foams is also discussed. A foam with 63% porosity, 87 ± 5 MPa yield strength, and 6.5 ± 1.3 GPa Young's modulus is found to be appropriate for a number of dental and orthopaedic applications.

Studentship and oppositional behaviour within physical education teacher education : a case study ; and, Between the rings and under the gym mat : a narrative

This thesis represents a part of a program of study that is reaching a closure. The broadest brush that could be applied to my work is that it concerns Physical Education Teacher Education (PETE), that it focuses on aspects of professional socialisation, and that it involves various case studies utilising naturalistic inquiry. Whilst it would be impossible and naive to believe that the reading of these texts will produce the meanings that I encourage, or have internalised, nevertheless the order of reading is at least something that I can argue for. Read in the order I suggest throughout the thesis I am hopeful that my subjectivities, and the learning and understandings I have reached may become clear. The purpose of this two part thesis is an exploration of the interplay or dialectic that exists between PETE students, academic staff and the subject matter within PETE. I have had to come to understand the limitations and advantages of insider research as the work has been completed at my University in the School of Human Movement and Sports Science where I have worked for twenty years. This thesis examines the extent to which studentship and oppositional behaviour underlies the dialectic that exists between the students and the various discourses within the program. I have written the study in two very different formats, one, a collection of stories about PETE and the other, an interpretative case study conducted during 1993 and 1994. Within the case study, studentship and oppositional behaviour were viewed as a measure of the extent to which students react and push against the forces of socialisation within their PETE program that is seen to represent dominant discourses, The following broad research questions were considered to enable the above analysis. 1. What is the nature of studentship and oppositional behaviour in a high status subject within PETE compared to a subject that is seen by students to be of little relevance and of low status? 2. How are studentship and oppositional behaviour related to students subjective warrants? 3. How are the studentship and oppositional behaviours exhibited by students related to the pedagogy and discourses reflected in the knowledge, beliefs and practices within the two sites. The starting point for this research was a study conducted as a totally separate research task (Swan, 1992) that investigated the hierarchies of subject knowledge within a PETE site and investigated the influence of such hierarchies upon student intention. A great deal of meta analysis exists about the manner in which a technocratic rationality pervades PETE but very little case study material of what this means to students and academic staff within such institutions is available. The stories in Between The Rings And Under The Gym Mat, which is the second part of this thesis, represent ‘the data’ differently from the case study, but they speak their own truth. At times the nature of the story is indistinguishable from the reality of the case study. Wexler (1992) undertook an ethnographic study about identity formation in three very different high schools, and published the findings in a book entitled Becoming Somebody. His introductory words about the nature of the social story he tells, are significant to this study and story. Social history is recounted by creative intervention that can only be made from culturally accessible materials. Ethnography is neither an objective realist, nor subjective imaginist account. Rather, it is an historical artefact that is mediated by elaborated distancing of culturally embedded and internally contradictory (but seemingly independent and coherent) concepts that take on a life of their own as theory. So, this is not ‘news from nowhere,’ but a theoretically structured story where both the story and its structure are part of my times. (p.6) The case study before you is organised with an analysis of studentship and oppositional behaviour detailed in chapter one. The following chapter conceptualises studentship and oppositional behaviour in relation to particular themes of professional socialisation, resistance to oppression and youth culture. Chapter three locates the case study to the major paradigmatic debates about the value and nature of the subject matter content within PETE, Chapter four outlines the case site, the research process and the research dilemma’s confronted in this study. The remaining three chapters are the case record as I can best understand it. In Between the Rings and under the Gym Mat (part B) the story most directly concerned with studentship and oppositional behaviour, is called Tale of Two Classes’. It takes on a very different reality to the case study (part A) and much can be said about the reality of lived experience which can be portrayed in narrative form as opposed to a clinical case study. Many of the other stories pose similar images that are contradictory and never quite complete. I have written a separate methodological section for the narrative stories. It is my intention that the case study and the series of stories should be viewed as essentially complementary, but also a discrete representation of a part of PETE. As part of the Ed D program I have undertaken four discrete research tasks as the starting point for this research I have referred to the first one (Hierarchies of Subject knowledge within PETE). I also undertook an action research project about ‘Teaching Poorly by Choice.’ A further piece of research was a somewhat reflective effort to draw together what this has all meant to me from a subjective and reflexive perspective. Such efforts are often seen as being self indulgent, as subjectivity in the form of lived experience sits uneasily in academia. A final paper involved an evaluation of Between the Rings and Under the Gym Mat from a pedagogical perspective by PETE professionals around the world. And that's the way things turned out.

Processing of fine-grained aluminum foam by spark plasma sintering

Porous materials are now becoming attractive to researchers interested in both scientific and industrial applications due to their unique combinations of physical, mechanical, thermal, electrical and acoustic properties in conjunction with excellent energy absorption characteristics. Metallic foams allow efficient conversion of impact energy into deformation work, which has led to increasing applications in energy absorption devices. In particular, foams made of aluminum and its alloys are of special interest because they can be used as lightweight panels, for energy absorption in crash situations and sound or heat absorbing functions in the automotive industry with the aim to reduce weight to improve crashworthiness, safety and comfort.