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Assessment of reliability performance based on truck driver satisfaction survey
No full textA study has been underway since 2022 to improve the performance of dump trucks in the Erdenet open pit mine in Mongolia. In the first year, our research team dynamically determined the fuel consumption of trucks based on the mining-technical conditions. The next objective of the research was to estimate the production performance of trucks in relation to mine depth and the obsolescence of the dump trucks. To achieve this goal, technical reliability analysis was performed using satisfaction surveys from drivers to determine which indicators to highlight and analyse. In labour process analysis, each particular job in any industry is graded by a combined assessment of the level of knowledge and required skill of the person to perform the job and the level of personal experience they can attain from the job. In manufacturing, jobs have their own grading, which provides the basis for wages commensurate with the level of professionalism required to perform the work. Thus, each industry will create a functionally related labour-wage system: job rank, professional degree, and wage rate. When mining companies determine the number of jobs available for a given year, they list the qualifications of the people required to fill each job. This will be the basis for proper planning of wage remuneration, professional development of workers, planned increases in wages, social welfare from profits and the redistribution of income reflected in budgets.</p
Investigating the rotation of cable bolts during pull out tests
No full textCable bolts are part of a more general category of structural elements known as wire ropes. Complexities of designing and manufacturing cable bolts have shrouded many mysteries in their performance both in academia and industry. Due to the compound nature of a cable, cables are known to rotate under axial load. This study has summarized and presented the observations and theories regarding the rotational tendency of cable bolts based on large-scale and small-scale laboratory pull out campaigns on various types of cable bolts encapsulated with a cementitious grout and two resins in monotonic and cyclic testing regimes. The results suggested that the role of rotation in reducing the axial capacity of the system is not as severe as once thought. Moreover, the results portray that an absolutes zero rotation test is an unrealistic scenario. Instead, the practitioner should take advantage of the unique failure mechanism of cable bolt systems in favour of the design.</p
Determination of coal burst risk zones using CT scanning of coal microstructure
No full textThe Australian Coal Association Research Program (ACARP) sponsored a research project (C28012 Extension) investigating the role of microfracture propagation contributing to the mechanism of gas related coal bursts. The research project used Computed Tomography (CT) scanning to identify microfracture networks and the spatial and statistic relationship of microfracture networks adjacent to known burst prone structures. An NSW coal mine was used as the case study mine for this assessment. The case study mine has experienced coal bursts and outbursts in relation to various geological structures consisting of dykes and a thrust fault. This paper defines the burst risk zone adjacent to structures at the case study mine and supports the theory of microfracture propagation to increase the microfracture frequency, in turn increasing gas desorption volumes. The research also highlighted that variability in microfracture networks was a key feature adjacent to structure, where low microfracture density or low permeability zones were observed that could act to restrict gas drainage into roadways. This paper presents the mechanics of gas desorption and gas flow during coal mine development drivage that can lead to gas related coal bursts and compares this with gas flow in areas of typical coal.</p
Styrene free polyester resin cartridges – a breakthrough technology for health and safety, with increased mechanical properties
No full textStyrene is a key ingredient in polyester resin capsules, as commonly used within underground mining rock bolting applications. Over the last decade, there has been an increase in research and associated medical knowledge regarding styrene safety, particularly its health impacts upon people. For example, the issue of carcinogenicity and harmful effects on fertility and unborn children has been identified. Due to these health concerns, the use of styrene-based resin products in civil construction projects has been subsequently banned in Europe. This scenario has further raised safety concerns within resin cartridge production facilities, as well as in the handling and usage of cartridge resin at the end customer’s site.In this paper, the characteristics and performance of a new generation of styrene free resin capsules is discussed. Among other relevant mechanical parameters, such as compressive strength and elastic modulus, stiffness properties in comparison with standard polyester resin capsules is discussed.Finally, the paper also presents field validation tests conducted in underground mines in Finland and Spain. In these tests, the focus was set on resin capsule installation, its repeatability and productivity. New styrene-free capsules have been positively tested on commonly used bolting rigs, for instance, the Sandvik ARI (Automatic Resin Injection) system. Laboratory and field data that has been compiled throughout product validation activities has confirmed the improved mechanical performance of the new styrene-free resin capsule technology and verifies its routine use for rock bolting applications in underground mines.</p
Polymeric ground consolidation chemical testing and quantification of in-situ performance
No full textThe methods of design and ultimate effectiveness of ground consolidation programs to regain stability of longwall face strata conditions vary widely and are often based on previous site-based precedence or what was considered successful at other sites in similar situations. Little quantitative work has been undertaken on the actual in-situ performance of ground consolidation material or the geomechanical behaviour of the various chemical types.This paper presents a summary of both laboratory material property testing and field-based quantification of rock mass improvement gained as a result of polymeric chemical injection, with a testing rational designed to quantify the polymeric chemical geomechanical properties, resin migration, zones of effectiveness, and quantification of the resultant rock mass improvement. This work program has recently been undertaken in conjunction with industry researchers, universities and across three longwall operations in the Bowen Basin.The results may be used to provide rock mechanics engineers with data and methods to improve the engineering basis for ground consolidation design in terms of product selection, risk management, and expected rock mass performance under various mining conditions and application parameters.</p
Development of models to improve vascularisation within islet-laden constructs with 3D bioprinting
No full textConventional pancreatic islet transplantation is a promising life-changing treatment for individuals with severe type 1 diabetes (T1D). However, due to the nature of islet isolation and purification, there is a complete disruption of the intra-islet vasculature system resulting in islet death and reduced function. Post-transplantation, the rate of intra-islet revascularisation and vascular density will determine the survival rate and functional capacity of these transplanted islets. In attempts to improve vascularisation in islets, three dimensional (3D) bioprinting is a popular method to biofabricate large tissue constructs that mimic the natural organisation found in the body. Different 3D bioprinting methods are employed to promote vascularisation via utilisation of different biomaterials and cell types. However, the quest is still ongoing to create vascularisation in a timely manner at early stages of islet transplantation. Although various 3D bioprinting techniques have been developed to support islet viability and function, the challenge of effective vascularisation between islet-laden construct and the host’s tissue remains.Therefore, this PhD project investigates a novel biofabrication approach to enhance both the rate of intra-islet revascularisation and density through creating vascularisation in islet-laden constructs. Our alternative approach utilises the Janus nozzle to create colinear constructs. We hypothesised that the creation of void spaces via the use of a sacrificial bioink can support oxygen and nutrient exchange without hindrance from the bioinks. Alongside this, empty space in the 3D construct can potentially enable the endothelial cells to form inter-connected vessel like formations between neighbouring cells further supporting the creation of vascularisation.In Chapter 2, bioink optimisation of an alginate/GelMA/gelatin of two bioink blends was developed to enable bioprinting at room temperature to remove the need for external temperature control. To evaluate the capabilities of the bioink blend, the first 3D bioprinting method explored was coaxial bioprinting. Filament extrusion and bioprinting of a scaffold were conducted to evaluate the printability but also the structural integrity of the bioink compositions. To further determine the characteristics of the bioink blend, rheology and mechanical characterisation was conducted to understand the behaviour of the bioink blend. Through these testings, the bioink showed shear thinning properties and self-recovering properties to support the 3D bioprinting extrusion process. Alongside this, mechanical strength of the scaffolds was supported by the Young’s modulus. Exposure of the bioink to human umbilical vein endothelial cells (HUVECs) showed cellular viability.In Chapter 3, an alternative method was explored utilising the Janus nozzle to contrast a colinear construct, where two bioinks are simultaneously side-by-side. This development of the model supports the concept of creating empty spaces, voids, in the 3D environment through the incorporation of a sacrificial bioink. Further optimisation of the bioinks was conducted to support this alternative model through the addition of alginate methacrylate (AlgMA) to support structural integrity. Inclusion of AlgMA showed stability at 37°C as compared to the model in Chapter 2. Moving ahead, stability at body temperature indicates the potential for transplantation post- 3D bioprinting. Additionally, HUVEC function and viability was supported in this colinear model with interconnected vessel-like formations forming in a 24-hour period post 3D bioprinting. Vessel maturation was observed between day 1 and day 7 through live/dead confocal staining showing the HUVECs were supported in this environment.Continuing in Chapter 4, in vivo transplantation of the colinear cell-laden constructs with islets showed the potential of angiogenesis in the subcutaneous region of mice. The 3D bioprinted cell-laden constructs can be manipulated to be placed in the subcutaneous region and remain intact by day 14 and day 21 post-transplantation. Presence of the human islets in the graft and their hormone insulin can confirm the presence of the hormones in the islets. Histological analysis can identify the construct at the interface of the subcutaneous region. Visualisation of blood vessels can be observed upon extraction of the graft. The colinear model holds promising results for the creation vascularisation to improve outcome of islets post-transplantation.Finally in Chapter 5, an economic analysis was conducted to determine whether implementation of 3D bioprinting as an alternative treatment to conventional islet transplantation can be cost-effective. The report has been based on assumptions and shows that 3D bioprinting can significantly reduce the economic burden of the islet transplantation procedure. The evidence in this report provides a foundation as to why implementing a new method can reduce economic burden and increase quality of life.These results show the potential of 3D bioprinting as an alternative method to break down the barrier by tackling vascularisation to enable broader application of islet transplantation.</p
Microenvironment Engineering of Carbon Based Transition Metal Single Atom Catalysts for Energy Conversion
No full textThe abstract for this item has not been populated.</p
Danger assessment for immigrant women
No full textSeveral risk factors have been associated with increased risk of violence, risk of intimate partner homicide and future life-threatening violence particularly severe and/or life threatening violence, among immigrant women. We cannot predict what will happen in your case, but we would like you to be aware of the danger of being killed in situations of abuse and for you to see how many of the risk factors apply to your situation.</p
Deep Learning for Assistive Navigation of Vision-impaired People
No full textVisually impaired people face numerous challenges in daily life due to their limited ability to perceive their surroundings. This lack of visual information can lead to diffculties in navigation, object recognition, and environment perception. Traveling safely and independently is one of the most challenging tasks, even with the assistance of white canes or guide dogs. Small collisions and falls are a daily norm for them, posing significant risks to their safety and well-being. Additionally, the lack of vision restricts their ability to explore new places freely, impacting their quality of life and their ability to fully engage in society.Assistive navigation systems are designed to address these challenges by utilizing advanced sensors as substitutes for vision. These technologies perceive the surroundings and provide visually impaired individuals with real-time information about their environment. However, these sensor-based obstacle detectors have limited functionality and reliability when facing complex and dynamic environments. Deep learning algorithms for scene perception offer a more comprehensive solution to this problem. These algorithms can analyze and interpret visual data with high accuracy, enabling the recognition of walkable paths and the detection of obstacles, which are the two most crucial factors for safe travel.Semantic segmentation offers a unified and efficient solution for pedestrian lane detection and obstacle sensing. By accurately classifying each pixel in an image, semantic segmentation allows for precise identification of pedestrian lanes and distant obstacles, ensuring that users can stay within walkable regions and receive collision warnings in advance. Combining semantic segmentation with monocular depth estimation further enhances this capability, offering a comprehensive 3D understanding of the environment. Monocular depth estimation uses a single camera to predict the distance and spatial arrangement of objects, providing depth information that complements the segmentation data.This thesis provides three major contributions. First, we review and evaluate state-of-the-art algorithms for pedestrian lane detection using a benchmark lane dataset. Second, we propose LSS-Net, a lightweight segmentation model for pedestrian scene understanding with low computational requirements. As part of this work, we create a novel pedestrian scene dataset called TrueSight for training and evaluating algorithms targeting real-world assistive navigation. Third, we propose AMT-Net, an efficient multi-task model for joint semantic segmentation and monocular depth estimation. This model uses a single-decoder architecture, achieving optimal computational efficiency on two challenging datasets. Our extensive experiments have demonstrated the state-of-the-art performance of the proposed networks. The work in the thesis contributes novel algorithms and labeled datasets for two important tasks in assistive navigation of blind people: real-time pedestrian lane detection and depth estimation from color images.</p
A consumer wisdom-informed conceptualization for understanding prosocial behaviors
No full textExisting literature has primarily studied factors related to prosocial behaviors in isolation. To further understand the multifaceted nature of prosocial behaviors, this research utilizes consumer wisdom as an overarching multidimensional framework to explore different facilitators of and barriers to prosocial behaviors. We develop a conceptual framework to illustrate how prosocial behaviors might play out in the real world, given human beings’ often conflicting motivations. After synthesizing qualitative data from a Delphi study involving three iterative rounds of data collection with behavior-change experts, our framework suggests possible associations between consumer wisdom and prosocial behaviors via multiple facilitators (values-based motivation, efficacy, self-relevance, and compassion) and barriers (self-focus and decision paralysis). Through the lens of consumer wisdom, this framework provides a comprehensive perspective transcending previous prosocial literature that has predominantly examined individual factors. Furthermore, practitioners and policymakers should integrate consumer wisdom as they develop and implement successful prosocial campaigns and initiatives.</p