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This thesis is a study of the near infra-red absorption spectrum of ethylidene fluoride.

<div>Fused deposition modeling (FDM) represents one of the most common techniques for rapid proto-typing in additive manufacturing (AM). This work applies image based thermography to monitor the FDM process in-situ. The nozzle temperature, print speed and print orientation were adjusted during the fabrication process of each specimen.</div><div>Experimental and numerical analysis were performed on the fabricated specimens. The combination of the layer wise temperature profile plot and temporal plot provide insights</div><div>for specimens fabricated in x, y and z-axis orientation. For the x-axis orientation build possessing 35 layers, Specimens B16 and B7 printed with nozzle temperature of 225 ➦C and</div><div>235 ➦C respectively, and at printing speed of 60 mm/s and 100 mm/s respectively with the former possessing the highest modulus, yield strength, and ultimate tensile strength. For the y-axis orientation build possessing 59 layers, Specimens B23, B14 and B8 printed with nozzle temperature of 215°C, 225°C and 235°C respectively, and at printing speed of 80 mm/s, 80 mm/s and 60 mm/s respectively with the former possessing the highest modulus and yield strength, while the latter the highest ultimate tensile strength. For the z-axis orientation build possessing 1256 layers, Specimens B6, B24 and B9 printed with nozzle temperature of 235°C, 235°C and 235°C respectively, and at printing speed of 80 mm/s, 80 mm/s and 60 mm/s respectively with the former possessing the highest modulus and ultimate tensile strength, while B24 had the highest yield strength and B9 the lowest modulus, yield strength and ultimate tensile strength. The results show that the prints oriented in the y-axis orientation perform relatively better than prints in the x-axis and z-axis orientation.</div>

The chip formation process in machining is accompanied by heat generation. The heat generated influences both the workpiece physical properties as well as the cutting tool. High temperatures accelerate tool wear and thermal softening which are not desirable because they alter the accuracy of the machined surface and tool life. Many studies have been done to lower the heat generated in cutting. A first approach is to use a cutting fluid but its effectiveness is limited by its ability to penetrate between the tool and the chip. A second approach is to remove the heat generated through a cooling cycle as in interrupted cutting. The idea is either to translate a wide tool to the side as it moves forward relative to the workpiece, which allows the dissipation throughout the body of the tool or to use a cutting edge in the form of a disk that rotates about its principal axis. The latter, known as a rotary tool, provides a rest period for the cutting edge, thus enabling the edge to be cooled and a continuously fresh portion of the edge to be engaged with the workpiece. The rotary tool can be either driven by an external power source or self-propelled. This thesis focuses on the self-propelled rotary tool (SPRT) process for machining of difficult-to-machine material such as bearing steels, where tool life is of particular concern. Since the cutting temperatures are known to influence tool life significantly, the first task in this investigation involved developing a model to analyze heat transfer and temperature distribution in the cutting tool during SPRT turning of the hardened 52100 steel (58 HRC). Both rotary and equivalent fixed tool processes are compared in terms of cutting tool temperatures generated. The model is based on the moving heat source theory of conduction and employs the Finite Element Method (FEM) for its solution. The model is experimentally verified through measurement of the cutting temperature distribution using an Infra-Red imaging camera under different cutting conditions. Predicted and measured temperatures show good overall agreement when they are measured along the cutting edge and measured temperatures are up to 50??ower in rotary tool cutting than in fixed tool cutting under the same conditions.

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The work presented here report findings in (1) infrared detectors based on p-GaAs/AlGaAs heterojunctions, (2) J and H aggregate sensitized heterojunctions for solar cell and photon detection applications, (3) heterojunctions sensitized with quantum dots as low cost solar energy conversion devices and near infrared photodetectors. (1)A GaAs/AlGaAs based structure with a graded AlGaAs barrier is found to demonstrate a photovoltaic responsivity of ~ 30mA/W (~ 450mV/W) at the wavelength of 1.8 mm at 300K. Additionally the graded barrier has enhanced the photoconductive response at 78 K, showing a responsivity of ~ 80mA/W with a D*=1.4×108 Jones under 1V bias at 2.7 mm wavelength. This is an approximately 25 times improvement compared to the flat barrier detector structure, probably due to the improved carrier transport, and low recapture rate in the graded barrier structure. However, these graded barrier devices did not indicate a photoresponse with photoconductive mode at 300K due to high shot noise. Additionally, two generation-recombination noise components and a 1/f noise component were identified. A series of GaAs/AlGaAs multilayer hetero-junction structures were tested as thermal detectors. A superlattice structure containing 57% Al fraction in the barrier and 3 × 1018 cm-3 p-doped GaAs emitter showed the highest responsivity as a thermal detector with a TCR of ~ 4% K-1, at 300K. (2)The photovoltaic properties of heterojunctions with J-/ H- aggregated dye films sandwiched between n– and p-type semiconductors were investigated for potential application as solar cells and IR detectors. Films of cationic dye Rhodamine-B-thiocyanate adsorbed on Cu2O substrate are found to form organized dye layers by self-assembled J- aggregation, resulting in large red-shifts in the photo -response. Additionally, cells sensitized with a pentamethine cyanine dye exhibited a broad spectral response originating from J- and H-aggregates. The photocurrent is produced by exciton transport over relatively long distances with significant hole-mobility as well as direct sensitized injection at the first interface. (3) A ZnO/PbS-QD/Dye heterostructure had enhanced efficiency compared to ZnO/Dye heterostructure as a solar cell. Furthermore, a ZnO/PbS-QD structure has demonstrated UV and NIR responses with 4×105V/W (390 nm) and 5.5×105 V/W (750 nm) under 1V bias at 300K.

This research details the development of a large-scale, computer vision-based touch screen capable of supporting a large number of simultaneous hand interactions. The system features a novel lightweight multi-point tracking algorithm to improve real-time responsiveness. This system was trialled for six months in an exhibition installation at World Expo 2005 in Aichi, Japan, providing a robust, fault-tolerant interface. A pilot study was then conducted to directly compare the system against other, more established input methods (a single-touch case, a two-mouse case and a physical prototype) to determine the effectiveness and affordances of the multi-touch technology for arranging information on a large-scale wall space in a paired collaborative task. To assist in this study, a separate visualisation and interaction classification tool was developed, allowing the replay of XML log data in real time to assist in the video analysis required for observation and hypothesis testing.

This thesis aims to investigate different infrared absorbing molecules and how their properties are affected by their incorporation into polymer nanoparticles. Metal-free phthalocyanine-H2Pc, uranyl super phthalocyanine-USPc, and europium bisphthalocyanine were studied-EuPc2; the latter two capable of IR absorption. Due to the discovery of USPc’s moisture sensitivity, only H2Pc and EuPc2 were derivatized to facilitate encapsulation in polystyrene nanoparticles through a miniemulsion polymerization. These novel phthalocyanines attained loadings of up to 41wt% and exhibit substantial broadening of absorption peaks. Furthermore, the EuPc2 loaded particles also reveal an unprecedented gain in extinction coefficient of the NIR and radical absorption peaks. The leaching behavior of the dye was also studied, as this had not been undertaken in the literature, and revealed the need for a method of polymerizing/chemically binding phthalocyanines into nanoparticles; with preliminary steps taken to realize this goal.

This thesis aims to investigate different infrared absorbing molecules and how their properties are affected by their incorporation into polymer nanoparticles. Metal-free phthalocyanine-H2Pc, uranyl super phthalocyanine-USPc, and europium bisphthalocyanine were studied-EuPc2; the latter two capable of IR absorption. Due to the discovery of USPc’s moisture sensitivity, only H2Pc and EuPc2 were derivatized to facilitate encapsulation in polystyrene nanoparticles through a miniemulsion polymerization. These novel phthalocyanines attained loadings of up to 41wt% and exhibit substantial broadening of absorption peaks. Furthermore, the EuPc2 loaded particles also reveal an unprecedented gain in extinction coefficient of the NIR and radical absorption peaks. The leaching behavior of the dye was also studied, as this had not been undertaken in the literature, and revealed the need for a method of polymerizing/chemically binding phthalocyanines into nanoparticles; with preliminary steps taken to realize this goal.

This research project compares different chemical and spectroscopic techniques aimed at finding a quick and cheap replacement for the measurement of digestibility of phosphorus (P) in different inorganic feed additives for pigs. This research yielded a comparison of the digestibility of different feed additives. P digestibility was determined from in vivo studies of pigs. The animal feed in the in vivo studies contained P levels below the nutrient requirements. The basal diet was a corn soybean meal base. Assessment was performed on 6 different inorganic P sources, rock phosphate (tricalcium phosphate (TCP)), meat and bone meal (MBM), mono/dicalcium phosphate (MDCP) and three different dicalcium phosphates (DCPs). Eight pigs where selected and placed into separate pens. Two were given basal diets and the other 6 diets were randomly selected and supplied with the different inorganic P sources. P digestibility was calculated by difference. The apparent P digestibility of the sources were: TCP at 46 %, the MBM at 85 %, MDCP at 71 % and three DCPs ranged from 49 % to 73 %. This substantiated that the apparent P digestibility in the major inorganic sources of P is significantly less than 100%. The in vitro or chemical methods of assessing phosphorus availability in animal feed included the commonly used feed extraction methods of water solubility and 2 % citric acid. These two methods showed significant differences between each other. Other chemical methods used included calcium chloride, ammonium acetate, sodium bicarbonate extractions, and a double extraction using hydrochloric acid (HCl) followed by sodium bicarbonate. The chemical methods showed non-significant correlation coefficients when compared to in vivo P digestibility of the six phosphate ingredients used. Infra-red spectroscopy is now commonly used in feed production for many other nutritional tests. NIR, although being able to obtain an R2 above 0.999 for correlation curves and factor prediction curves, could not obtain a self prediction of the calcium phosphates due to the large Mahalanobis Distance. P digestibility predicted by MIR showed close agreement with the in vivo P digestibility. Again due to the small number of ingredients tested in the pig trial, the prediction of digestibility using MIR could only be compared to it self. Hence MIR can only be used as an estimate until more data can be obtained. The P31 SS-MAS-NMR indicated one of the DCPs was made up of 3 or more P compounds by displaying 3 major peaks. All the P chemical shifts from the faeces had different positions to the P peaks in the ingredients, indicating some sort of change in the P form. Overall the chemical methods were unable to predict P digestibility, and while the spectroscopic techniques showed promise, they still require more work to examine many more feed additives.Invitro, invivo, phosphorus, digestibility, swine, infra-red spectroscopy, solid state NMR