On the Feasibility of Embedding Fe-SMA Short-Fibers in Ultra-High-Performance Concrete for Self Prestressing

Prestressing concrete is common practice in the construction industry. Current prestressing methods are often used for large, straight members and come with geometric limitations for curved or thin-walled members. Shape memory alloy short fibers embedded within concrete mixes may allow for the prestressing of geometries not possible with traditional methods. This study reviews past research on prestressing concrete with shape memory alloys, evaluates the achievable recovery stress within an Fe-SMA (when deformed at room temperature), and examines the mechanical behavior of Ductal dark grey UHPC when heated to 250 °C. The flexural behavior, compressive strength, and fiber-to-concrete bond strength of heated and non-heated UHPC specimens are investigated to better understand the effect high temperatures on concrete properties. Results from flexure tests indicate heating specimens increases stiffness and modulus of rupture by 6.8% and 28.1 %, respectively. The compressive strength of heated specimens was on average 53.5% higher than non-heated specimens. Steel fiber pullout tests show that fiber-to-concrete bond strength typically increases when specimens are heated to 250 °C. The tests on heated UHPC specimens show that the Ductal mix used behaves favorably upon heating and would likely work well for Fe-SMA prestressing applications. Fe-SMA recovery stress was found to reach approximately 50 ksi. This indicates that Fe-SMA fibers may be able induce about 354 psi of prestress for every 1% (per volume) of Fe-SMA fibers added to a UHPC mix

On the Feasibility of Embedding Fe-SMA Short-Fibers in Ultra-High-Performance Concrete for Self Prestressing

Prestressing concrete is common practice in the construction industry. Current prestressing methods are often used for large, straight members and come with geometric limitations for curved or thin-walled members. Shape memory alloy short fibers embedded within concrete mixes may allow for the prestressing of geometries not possible with traditional methods. This study reviews past research on prestressing concrete with shape memory alloys, evaluates the achievable recovery stress within an Fe-SMA (when deformed at room temperature), and examines the mechanical behavior of Ductal dark grey UHPC when heated to 250 °C. The flexural behavior, compressive strength, and fiber-to-concrete bond strength of heated and non-heated UHPC specimens are investigated to better understand the effect high temperatures on concrete properties. Results from flexure tests indicate heating specimens increases stiffness and modulus of rupture by 6.8% and 28.1 %, respectively. The compressive strength of heated specimens was on average 53.5% higher than non-heated specimens. Steel fiber pullout tests show that fiber-to-concrete bond strength typically increases when specimens are heated to 250 °C. The tests on heated UHPC specimens show that the Ductal mix used behaves favorably upon heating and would likely work well for Fe-SMA prestressing applications. Fe-SMA recovery stress was found to reach approximately 50 ksi. This indicates that Fe-SMA fibers may be able induce about 354 psi of prestress for every 1% (per volume) of Fe-SMA fibers added to a UHPC mix

The State, War and Strategy: Australia’s Strategic Disconnect with its Wars of Choice in Iraq and the wider Persian Gulf Region, 1990–2014

This dissertation examines the strategic significance of Australia’s deployment of elements of its military power to a series of wars of choice in the Middle East region between 1990-2014. From a Realist perspective, it establishes a series of strategic misalignments between Australian government decision and the state’s involvement in war. It demonstrates Australia displayed consistent strategic inconsistency between the nation’s strategic outlook and its approaches to war, military power, and strategy

Interstitial diagnosis and treatment of breast tumours

This thesis exploits the interaction of light with breast tissue for diagnosis and therapy. Optical biopsy is an experimental technique, based on Elastic Scattering Spectroscopy (ESS), being developed for characterising breast tissue. An optical probe interrogates tissue with a white light pulse, with spectral analysis of the reflected light. 264 spectral measurements (50 patients) were obtained from a range of breast tissues and axillary lymph nodes and correlated with conventional histology of biopsies from the same sites. Algorithms for spectral analysis were developed using ANN (Artificial Neural Network), HCA (Hierarchical Cluster Analysis) and MBA (Model Based Analysis). The sensitivity and specificity for cancer detection in breast and lymph nodes were: [diagram]. Interstitial Laser Photocoagulation (ILP) involves image guided, thermal coagulation of lesions within the breast using laser energy delivered via optical fibres positioned percutaneously under local anaesthetic. Two groups were studied: 1) Nineteen patients with benign fibroadenomas underwent ILP and the results compared with 11 treated conservatively. Thirteen ILP patients (14 fibroadenomas) and 6 controls (11 fibroadenomas) have reached their one-year review: [diagram]. These differences are statistically significant (P<0.001). 2)Six patients with primary breast cancers underwent ILP (with pre- and post-ILP contrast enhanced MRI) within 3 weeks of diagnosis and were then treated with Tamoxifen. Four underwent surgery at 3 months, two showing complete tumour ablation. MRI was reasonably accurate at detecting residual tumour. In conclusion: a) optical biopsy is a promising 'real time' diagnostic tool for breast disease. b) ILP could provide a simple and safe alternative to surgery for fibroadenomas. c) ILP with MRI monitoring may be an alternative to surgery in the management of some patients with localised primary breast cance

Heroes and Hooligans: The Heterogeneity of Video Game Modders

Video games are hugely popular, generating more than twice the revenue of global movie and music industries combined. Whilst technically illegal and often carrying negative connotations, modding constitutes a moral grey area that is commonly accepted, often encouraged by proprietary owners and forum-centred gaming communities. Literature reflects a disparity between outsider and insider perceptions of modding, with a paucity of studies reflecting insider perspectives. Using Reddit forum data, this study contributes insight into perceptions of modding held by gamers and ‘modders’, as described in their words and their territory. Thematic analysis revealed four main themes relating to unfairness in the vendor community, modders as antagonists, differences between modders and modding as forms of self-defence. Conclusions include that modding appears to have both pro- and antisocial applications, but many people and organisations demonise modders as a homogeneous group, which may encourage antisocial behaviours

Designing Second-Screening Experiences for Social Co-Selection and Critical Co-Viewing of Reality TV

Public commentary related to reality TV can be overwhelmed by thoughtless reactions and negative sentiments, which often problematically reinforce the cultural stereotyping typically employed in such media. We describe the design and month-long evaluation of a mobile "second-screening" application, Screenr, which uses co-voting and live textual tagging to encourage more critical co-viewing in these contexts. Our findings highlight how Screenr supported interrogation of the production qualities and claims of shows, promoted critical discourse around the motivations of programmes, and engaged participants in reflecting on their own assumptions and views. We situate our results within the context of existing second-screening co-viewing work, discuss implications for such technologies to support critical engagement with socio-political media, and provide design implications for future digital technologies in this domain

Diagnosis of breast cancer using elastic-scattering spectroscopy: preliminary clinical results

We report on the first stages of a clinical study designed to test elastic-scattering spectroscopy, mediated by fiberoptic probes, for three specific clinical applications in breast-tissue diagnosis: (1) a transdermal-needle (interstitial) measurement for instant diagnosis with minimal invasiveness similar to fine-needle aspiration but with sensitivity to a larger tissue volume, (2) a hand-held diagnostic probe for use in assessing tumor/resection margins during open surgery, and (3) use of the same probe for real-time assessment of the `sentinel' node during surgery to determine the presence or absence of tumor (metastatic). Preliminary results from in vivo measurements on 31 women are encouraging. Optical spectra were measured on 72 histology sites in breast tissue, and 54 histology sites in sentinel nodes. Two different artificial intelligence methods of spectral classification were studied. Artificial neural networks yielded sensitivities of 69% and 58%, and specificities of 85% and 93%, for breast tissue and sentinel nodes, respectively. Hierarchical cluster analysis yielded sensitivities of 67% and 91%, and specificities of 79% and 77%, for breast tissue and sentinel nodes, respectively. These values are expected to improve as the data sets continue to grow and more sophisticated data preprocessing is employed. The study will enroll up to 400 patients over the next two years

Evidence for core exosome independent function of the nuclear exoribonuclease Rrp6p

The RNA exosome processes and degrades RNAs in archaeal and eukaryotic cells. Exosomes from yeast and humans contain two active exoribonuclease components, Rrp6p and Dis3p/Rrp44p. Rrp6p is concentrated in the nucleus and the dependence of its function on the nine-subunit core exosome and Dis3p remains unclear. We found that cells lacking Rrp6p accumulate poly(A)+ rRNA degradation intermediates distinct from those found in cells depleted of Dis3p, or the core exosome component Rrp43p. Depletion of Dis3p in the absence of Rrp6p causes a synergistic increase in the levels of degradation substrates common to the core exosome and Rrp6p, but has no effect on Rrp6p-specific substrates. Rrp6p lacking a portion of its C-terminal domain no longer co-purifies with the core exosome, but continues to carry out RNA 3′-end processing of 5.8S rRNA and snoRNAs, as well as the degradation of certain truncated Rrp6-specific rRNA intermediates. However, disruption of Rrp6p–core exosome interaction results in the inability of the cell to efficiently degrade certain poly(A)+ rRNA processing products that require the combined activities of Dis3p and Rrp6p. These findings indicate that Rrp6p may carry out some of its critical functions without physical association with the core exosome

Pan-viral serology implicates enteroviruses in acute flaccid myelitis.

Since 2012, the United States of America has experienced a biennial spike in pediatric acute flaccid myelitis (AFM)1-6. Epidemiologic evidence suggests non-polio enteroviruses (EVs) are a potential etiology, yet EV RNA is rarely detected in cerebrospinal fluid (CSF)2. CSF from children with AFM (n = 42) and other pediatric neurologic disease controls (n = 58) were investigated for intrathecal antiviral antibodies, using a phage display library expressing 481,966 overlapping peptides derived from all known vertebrate and arboviruses (VirScan). Metagenomic next-generation sequencing (mNGS) of AFM CSF RNA (n = 20 cases) was also performed, both unbiased sequencing and with targeted enrichment for EVs. Using VirScan, the viral family significantly enriched by the CSF of AFM cases relative to controls was Picornaviridae, with the most enriched Picornaviridae peptides belonging to the genus Enterovirus (n = 29/42 cases versus 4/58 controls). EV VP1 ELISA confirmed this finding (n = 22/26 cases versus 7/50 controls). mNGS did not detect additional EV RNA. Despite rare detection of EV RNA, pan-viral serology frequently identified high levels of CSF EV-specific antibodies in AFM compared with controls, providing further evidence for a causal role of non-polio EVs in AFM