The Effect of Growth Promoting Implants on Feedlot Performance by Gelbvieh Bulls

The objective of this research was to determine the effect on feedlot performance of implanting various growth promotants in young bulls. Responses to these various implants by bulls were compared to a control group of bulls to determine the differences in feedlot performance. These comparisons provide information to help determine the most effective methods of bull feeding

Inertial, Transient, and Turbulent Flow through Deformable and Propagating Fractures: Theory and Computational Engineering

Fluid flow in deformable fractures is important to many natural and industrial geological engineering applications including contaminant transport, geothermal energy, and hydraulic stimulation. Large-scale simulations of flow through fractures are almost exclusively based on the Poiseuille flow model which contains the ingrained assumptions of laminar quasi-steady-state flow conditions with negligible inertia. The high flow rates involved in industrial applications bring these assumptions into question, but the only alternative is the Navier-Stokes equations which are computationally prohibitive at reservoir scales. This thesis seeks to address the gap in available models by introducing a new reduced-dimension model that is capable of capturing inertial and transient flow behaviours without the computational burden of the Navier-Stokes equations. First, a new fracture flow model is derived from the higher-dimensional Navier-Stokes equations by integrating over the fracture aperture and making simplifying assumptions which are less restrictive than those of Poiseuille flow. This new model, dubbed the GG22 fracture flow model, yields a two-field model (fluid flux and pressure) governed by the conservation of mass and momentum. The GG22 model conserves energy and is shown to include both Poiseuille flow and Forchheimer flow as limiting cases. The performance of the GG22 model is verified against the existing Poiseuille flow model and the solution to the full Navier-Stokes equations in three benchmarks problems. The GG22 model demonstrates complex transient and inertial behaviours not previously captured and produces up to 400% improvements in error over Poiseuille flow in steady-state flow conditions for 1 ≤ Re ≤ 100. The GG22 model is demonstrated to be superior in all tested applications where the inertial forces are greater than viscous forces (Re ≥ 1) and when aperture varies in space and/or time. Next, a simulator to solve the GG22 governing equations in rigid fractures is developed. Novel numerical methods were developed as the GG22 model is more complex than Poiseuille flow. Since the GG22 model is derived from the Navier-Stokes equations, numerical methods developed for the Navier-Stokes equations may be adapted, but the new model contains its own idiosyncrasies which must be addressed. An explicit multi-step finite volume method is developed and verified. The method is based on deriving a Poisson equation for pressure with an additional continuity correction to overcome numerical instabilities. The critical timestep is derived and shown to be a function of the fundamental frequency of the fracture-fluid system and the maximum fluid velocity. The results show excellent agreement with analytical solutions, and the method demonstrates a first-order rate of fluid flux convergence in time and a second-order rate of pressure convergence in space. Applying the model to a travelling aperture wave simulating seismic excitation reveals the changes in behaviours introduced by inertia and transience. These behaviours include lower average fluxes, higher pressures, and phase-shifts in the fluid response compared to the predictions of Poiseuille flow. Finally, the GG22 model is numerically coupled with mechanical deformation of a rock mass to simulate the complex industrial applications of interest. A monolithic fully-coupled hydro-mechanical finite element - finite volume model with cohesive fracture propagation is developed and verified. The Newton-Raphson solution algorithm demonstrates poor iterative convergence behaviour, so an adaptive steepest descent line-search with Aitken relaxation is introduced to improve the rate of convergence. The hydro-mechanical model is applied to fracture flow between oscillating elastic plates. The combined effects of inertia and transience are demonstrated to create phase-shifts in the fluid response, larger fluid pressures and rock mass stresses compared to the Poiseuille flow predictions, and induce wave-like behaviour even in a quasi-static rock mass. The hydro-mechanically coupled fracture propagation model is used to examine the role of inertia and turbulence in the propagation of planar KGD-like and axisymmetric radial hydraulic fractures with constant fluid injection rates. In KGD-like fracture, inertial effects are negligible at flow rates that could be expected in practice. If the injection rate is large enough to invoke turbulence, then significantly different fracture propagation behaviour is observed. Turbulence in KGD-like fractures leads to shorter fractures with larger apertures due to the increased fluid resistance. In radial fractures, the effects of inertia and turbulence only manifest near the wellbore and lead to changes in fracture shape, but have little impact on tip behaviour or fracture length. Turbulence creates increased wellbore pressures and apertures while inertial effects decrease the wellbore pressure and aperture. Turbulent and inertial effects near the wellbore account for the majority of the pressure loss along the fracture and provide a potential explanation for the empirically observed phenomenon of entrance losses. Turbulent and inertial forces have significant effects on injection pressure predictions, and predictions which neglect these phenomena are likely to exhibit significant deviations from the true pressure behaviour. Using water as the injection fluid, turbulence is the dominant mechanism that leads to departures from the Poiseuille flow solution at high Re. The solution departs immediately upon the manifestation of turbulence, while inertial effects manifest at higher flow rates. Using slickwater as the injection fluid, the opposite trend is observed: inertial effects manifest first at modest flow rates, while turbulent effects are delayed to higher flow rates. In general, high Reynolds number flow is more common in industrial fracture flow applications than considered by current models. The threshold for departure from the Poiseuille flow solution is low and the differences in the solutions are large. This thesis provides a new model to bridge the gap between the physically restrictive Poiseuille flow model and the computationally prohibitive Navier-Stokes equations for the simulation of coupled flow processes in fractures. This new model provides a resource for the analysis and viability of many different applications including geothermal energy, carbon storage, seismic analysis, and contaminant transport among many others. It is recommended that the GG22 model be adopted for the modelling of fracture flow applications in all cases

The Effect of Synovex-S Implants on Feedlot Performance of Angus Bulls and Early Feedlor Period Castrated Angus Bulls

The objective of this research was to determine the effect on feedlot performance of implanting bulls and steers with Synovex-S, and comparing steers to bulls. Profit or loss upon marketing was also studied. Responses to these treatments in terms of feedlot performance provide information to help determine the most effective method of feeding bulls or steers and revenue in dollars upon sale assists in determining the best management scheme for profit

Metastable 9-Fluorenone: Blue-Shifted Fluorescence, Single-crystal-To-Single-Crystal Reactivity, and Evaluation as a Multimodal Fingermark Visualization Treatment

A metastable form of 9-fluorenone (MS9F) has been characterized using Raman spectroscopy, fluorimetry, and X-ray diffraction techniques. MS9F emits blue fluorescence (λmax = 495 nm) upon 365 nm irradiation and undergoes a single-crystal-tosingle-crystal (SCSC) transformation to reach the ground state form (GS9F) over ca 30 minutes, whereupon it emits the expected green fluorescence. A structure-property relationship for this fluorescent behavior has been posited. MS9F and GS9F were applied as a means of visualizing latent fingermarks on a non-porous surface. This approach identified three different modes of fluorescent fingermark visualization using 9-fluorenone

The Effects of Breed and Implant on Bullock Beef

Ninety-seven Angus and 98 Gelbvieh crossbred bulls were used to evaluate the effects of Ralgro, Synovex-H and Synovex-S implants on the growth, carcass and palatability traits of young bulls. The influence of the growth promoting implants on the feedlot performance of the bulls was dependent on their breed type and their stage growth. Percentage retail yield was the only carcass characteristic that was affected by the implants. The implanted bulls yielded carcasses with more external fat and less desirable yield grades than the controls. Rib eye area was not affected by the implants. Breed influenced feedlot performance, carcass composition and quality and palatability attributes more than the implants. The large-framed, late maturing Gelbvieh crossbred bulls grew faster and produced carcasses yielding higher percentages of boneless and produced carcasses yielding higher percentages of boneless trimmed retail cuts than the Angus bulls. The quality grades and palatability traits of the Gelbvieh bulls were marginal. The Angus bull carcasses has very acceptable yield grades (YG-2) and more desirable quality grades and sensory evaluations than the Gelbvieh crossbred bulls. Thus, the use of medium-framed intact males may be more appropriate than the larger framed breeds to produce a more acceptable product for both the packer and the consumer. Packer acceptability needs to be enhanced to make the use of intact males economically feasible for the producer

Visual based Tomato Size Measurement System for an Indoor Farming Environment

As technology progresses, smart automated systems will serve an increasingly important role in the agricultural industry. Current existing vision systems for yield estimation face difficulties in occlusion and scalability as they utilize a camera system that is large and expensive, which are unsuitable for orchard environments. To overcome these problems, this paper presents a size measurement method combining a machine learning model and depth images captured from three low cost RGBD cameras to detect and measure the height and width of tomatoes. The performance of the presented system is evaluated on a lab environment with real tomato fruits and fake leaves to simulate occlusion in the real farm environment. To improve accuracy by addressing fruit occlusion, our three-camera system was able to achieve a height measurement accuracy of 0.9114 and a width accuracy of 0.9443.Comment: 10 Pages, 12 Figure

Metadiscourse repertoire of L1 Mandarin undergraduates writing in English : a cross-contextual, cross-disciplinary study

This article presents a qualitative, comparative study of metadiscourse in the academic writing of two groups of undergraduate students working in two different disciplines. The groups of students were: 1) Native speakers of Mandarin studying in China through the medium of English; 2) Native speakers of Mandarin studying in the UK through the medium of English. For each group of students, we examined writing undertaken in two undergraduate disciplinary courses: Literary Criticism and Translation Studies. Our aim was to extend research into English writing by L1 Mandarin speakers, and to identify patterns of difference and similarity both between educational contexts and between disciplines. Results suggest that patterns of metadiscourse use in our corpus are associated with both disciplinary and contextual factors, but that contextual factors may have a stronger effect than disciplinary factors. For our data, local institutional culture seems to have a noticeable influence on student writers' use of metadiscourse

Seeing the Fruit for the Leaves: Robotically Mapping Apple Fruitlets in a Commercial Orchard

Aotearoa New Zealand has a strong and growing apple industry but struggles to access workers to complete skilled, seasonal tasks such as thinning. To ensure effective thinning and make informed decisions on a per-tree basis, it is crucial to accurately measure the crop load of individual apple trees. However, this task poses challenges due to the dense foliage that hides the fruitlets within the tree structure. In this paper, we introduce the vision system of an automated apple fruitlet thinning robot, developed to tackle the labor shortage issue. This paper presents the initial design, implementation,and evaluation specifics of the system. The platform straddles the 3.4 m tall 2D apple canopy structures to create an accurate map of the fruitlets on each tree. We show that this platform can measure the fruitlet load on an apple tree by scanning through both sides of the branch. The requirement of an overarching platform was justified since two-sided scans had a higher counting accuracy of 81.17 % than one-sided scans at 73.7 %. The system was also demonstrated to produce size estimates within 5.9% RMSE of their true size.Comment: Accepted at the International Conference on Intelligent Robots and Systems (IROS 2023

The Cyclical Development of Trypanosoma vivax in the Tsetse Fly Involves an Asymmetric Division

International audienceTrypanosoma vivax is the most prevalent trypanosome species in African cattle. It is thought to be transmitted by tsetse flies after cyclical development restricted to the vector mouthparts. Here, we investigated the kinetics of T. vivax development in Glossina morsitans morsitans by serial dissections over 1 week to reveal differentiation and proliferation stages. After 3 days, stable numbers of attached epimastigotes were seen proliferating by symmetric division in the cibarium and proboscis, consistent with colonization and maintenance of a parasite population for the remaining lifespan of the tsetse fly. Strikingly, some asymmetrically dividing cells were also observed in proportions compatible with a continuous production of pre-metacyclic trypomastigotes. The involvement of this asymmetric division in T. vivax metacyclogenesis is discussed and compared to other trypanosomatids

Intersections of nationality, gender, race and crime in news reporting: the case of Oscar Pistorius – Olympian and murderer

Taking as the starting point the importance of adopting an intersectional approach to studying mediatised representations, this study focuses on media construals of the South African athlete Oscar Pistorius. Spanning a range of intersecting identities - he is white, male, disabled, a sports champion and a convicted murderer - Pistorius presents an important case to study. In this paper, we focus on the period from his success in the 2012 London Olympics to his 'fall from grace' after fatally shooting his girlfriend in 2013. We use a combination of corpus linguistic tools and methods, and Critical Discourse Analysis, to interrogate corpora of press articles published in major British and South African newspapers. Investigating collocational patterns surrounding Pistorius, we show how media ‘mix and match’ aspects of his identity to construct a particular kind of persona. Whereas his disability and (trans)national identity are foregrounded in constructing him as a sports hero, his new emotionality and mental vulnerability are emphasized through gendered representations in the UK while a largely individual representation dominates in South Africa, where he is referred to overwhelmingly by name and in terms of his crime as an amputee, and only obliquely as white and male. At the theoretical level, our study adds to the body of research which challenges the notion that individual experience can be understood by categorising people in terms of one identity component (gender, race, ethnicity). More importantly, it shows that different aspects of identities are foregrounded or backgrounded to navigate shifts in salience in sometimes conflicting identity/ies, and that this is accomplished differently in two different media traditions. At the methodological level, this study shows the potential of a diachronic collocational analysis to unravel patterns of intersectionality in mediatised identity constructions