Recently designed Pepfactants® are an innovative type of nano-technological products, which could potentially replace conventional surfactants in broad-ranging applications. Currently, Pepfactants® technology is still in an initial design period at the laboratory scale. In order to develop the industrial-scale production of Pepfactants®, the design group has proposed simulated strategies for industrial-scale Pepfactants® manufacture and a desire to improve these strategies with regards to sustainability. This project aimed to assist Pepfactants® designers to understand the environmental footprint of simulated Pepfactant® AM1 manufacturing process, using the methodology of Life Cycle Assessment (LCA) – a comprehensive tool to quantify the environmental impacts from products and processes. To find the environmental shortcomings of the proposed manufacturing process for Pepfactant® AM1, the LCA outcomes were compared with published life cycle information of traditional chemical surfactant Lineal Alkylbenzene Sulphonate (LAS) production. Following LCA methodology, a life cycle inventory was compiled based on the simulated AM1 manufacture, which determined the environmental impact assessment for both AM1 and LAS production. In the LCA boundaries disregarding the usage of both surfactants, the quantitative LCA comparison results indicated that raw material and energy requirements of AM1 manufacture were much higher than LAS production, estimated to be 3,186 t/t AM1 against 31.1t/t LAS and 1,564,000MJ/t AM1 against 69,870MJ/t LAS respectively. Additionally, compared with LAS production, enormous water consumption (2,651 t/t AM1) and CO2 emission (522 t/t AM1) were also shown to be severe environmental problems for AM1 manufacture. Furthermore, the AM1 manufacture presents apparent problems with environmental impacts of nutrification, human toxicity, photochemical oxidant formation and acidification in comparison with LAS production. Other than providing the optimisation point in the view of environmental impacts for Pepfactant® AM1 manufacture, the results of experimental work in this project showed that as the surfactant concentration increases a greater foam height of Pepfactant® AM1 was achieved than when (from 7mm to 52mm between 15μM and 100μM) compared with LAS (from 8mm to 53mm between 31.3μM and 2,000μM) in the same aeration duration. This result demonstrated the great potential of AM1 to replace LAS based on the LCA functional unit – 1 tonne of products. The experiments results implied that 1 tonne of AM1 is able to have the same foaming ability as approximate 25 tonnes of LAS. Consequently, the environmental impacts from Pepfactant® AM1 manufacture are reduced by 25 times in the extended LCA boundaries linked to the quantitative usage comparison of these two surfactants. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1317664 / Thesis (M.Eng.Sc.) -- University of Adelaide, School of Chemical Engineering, 2008

Multi-trailer articulated heavy vehicles (MTAHVs) exhibit unstable motion modes at high speeds, including jack-knifing, trailer swing, and roll-over. These unstable motion modes may lead to fatal accidents. On the other hand, these vehicle combinations have poor maneuverability at low speeds. Of all contradictory design criteria of MTAHVs, the trade-off relationship between the maneuverability at low speeds and the lateral stability at high speeds is the most important and fundamental. This trade-off relationship has not been adequately addressed. The goal of this research is to address this trade-off relationship through the design optimization of MTAHVs with active safety systems. A parallel design optimization (PDO) method is developed and applied to the design of MTAHVs with integrated active safety systems, which involve active trailer steering (ATS) control, anti-roll (AR) control, differential braking (BD) control, and a variety of combinations of these three control strategies. To derive model-based controllers, a single-trailer articulated heavy vehicle (STAHV) model with 5 degrees of freedom (DOF) and a MTAHV model with 7 DOF are generated. The vehicle models are validated with those derived using a commercial software package, TruckSim, in order to examine their applicability for the design optimization of MTAHVs with active safety systems. The PDO method is implemented to perform the concurrent design of the plant (vehicle model) and controllers. To simulate the closed-loop testing maneuvers, a driver model is developed and it is used to drive the virtual vehicle following the prescribed path. Case studies indicate that the PDO method is effective for identifying desired design variables and predicting performance envelopes in the early design stages of MTAHVs with active safety systems. / UOIT

The Variable Displacement Engine (VDE) is a new generation of engines that are designed to decrease the fuel consumption at the cruise speed of a vehicle. The isolation of the VDE's new vibration pattern is beyond the capabilities of conventional mounts and bushings. Consequently, in this thesis, novel active and semi-active solutions are proposed to develop various semi-active and active hydraulic bushing proof-of-concept systems that may solve the isolation problem in a VDE system. <br /><br /> The dynamic stiffness response, which is the transfer function that relates the engine displacement to the transmitted force, is normally used as the key design criterion for engine mounts and bushings. In this thesis, a linear mathematical model of a conventional hydraulic bushing is purposed. The validity of the mathematical model is confirmed by an experimental analysis, and the various parameters in the dynamic stiffness equation are evaluated. The experimental results indicate that the dynamic stiffness frequency response of the conventional hydraulic bushing has both soft and stiff regions. The soft region is limited to low frequencies. For the VDE isolation, the goal is to provide a soft bushing for a wider range of frequencies than a conventional bushing can accommodate. Addition of a short inertia track, similar to a decoupler used in conventional hydraulic engine mounts, may be used to extend the soft region of a conventional hydraulic bushing, and the experimental results validate it. <br /><br /> Since the short inertia track provides no additional damping, a supplementary Magnetorheological (MR) valve is also devised. The MR valve has the advantage to minimize the amount of MR fluid used, which significantly reduces the cost of the overall system. The novel valve allows the damping coefficient of the bushing assembly to be controlled by varying the electrical current input to a solenoid coil. A mathematical model is derived for the MR bushing, and is validated experimentally. <br /><br /> In addition, an active bushing to solve the VDE isolation problem is purposed in this thesis. In this bushing, a magnetic actuator, composed of a permanent magnet and a solenoid coil, is included in the active bushing. This active chamber affects the dynamic stiffness response of the bushing by altering the bushing's internal pressure. The nonlinear equation of motion of the permanent magnet is linearized and is incorporated into the new mathematical model of the system. The new purposed model for the active bushing is in good agreement with the experimental results. This active chamber is also proved capable of producing complex dynamic stiffness frequency response. <br /><br /> The conclusion is that the proposals in this thesis can contribute to the isolation of the vibration pattern, imposed by the application of a VDE system.

We focus on determining the underlying physical cause of a Seyfert galaxy's appearance as type a 1.8 or 1.9. Are these "intermediate" Seyfert types typical Seyfert 1 nuclei reddened by central dusty tori or by nuclear dust lanes/spirals in the narrow-line region? Or, are they similar to NGC 2992, objects that have intrinsically weak continua and weak broad emission lines? Our study compares measurements of the reddenings of the narrow and broad-line regions with each other and with the X-ray column derived from XMM Newton 0.5-10 keV spectra to determine the presence and location of dust in the line of sight for a sample of 35 Seyfert 1.8s and 1.9s. From this, we find that Seyfert 1.9s are an almost equal mix of low-flux objects with unreddened broad line regions, and objects with broad line regions reddened by an internal dust source, either the torus or dust structures on the same size scale as the narrow line region. The 1.9s that recieved this designation due to a low continuum flux state showed variable type classifications. All three of the Seyfert 1.8s in our study are probably in low continuum states. Many objects have been misclassified as Seyfert 1.8/1.9s in the past, probably due to improper [N II]/H-alpha deconvolution leading to a false detection of weak broad H-alpha.

The Variable Displacement Engine (VDE) is a new generation of engines that are designed to decrease the fuel consumption at the cruise speed of a vehicle. The isolation of the VDE's new vibration pattern is beyond the capabilities of conventional mounts and bushings. Consequently, in this thesis, novel active and semi-active solutions are proposed to develop various semi-active and active hydraulic bushing proof-of-concept systems that may solve the isolation problem in a VDE system. <br /><br /> The dynamic stiffness response, which is the transfer function that relates the engine displacement to the transmitted force, is normally used as the key design criterion for engine mounts and bushings. In this thesis, a linear mathematical model of a conventional hydraulic bushing is purposed. The validity of the mathematical model is confirmed by an experimental analysis, and the various parameters in the dynamic stiffness equation are evaluated. The experimental results indicate that the dynamic stiffness frequency response of the conventional hydraulic bushing has both soft and stiff regions. The soft region is limited to low frequencies. For the VDE isolation, the goal is to provide a soft bushing for a wider range of frequencies than a conventional bushing can accommodate. Addition of a short inertia track, similar to a decoupler used in conventional hydraulic engine mounts, may be used to extend the soft region of a conventional hydraulic bushing, and the experimental results validate it. <br /><br /> Since the short inertia track provides no additional damping, a supplementary Magnetorheological (MR) valve is also devised. The MR valve has the advantage to minimize the amount of MR fluid used, which significantly reduces the cost of the overall system. The novel valve allows the damping coefficient of the bushing assembly to be controlled by varying the electrical current input to a solenoid coil. A mathematical model is derived for the MR bushing, and is validated experimentally. <br /><br /> In addition, an active bushing to solve the VDE isolation problem is purposed in this thesis. In this bushing, a magnetic actuator, composed of a permanent magnet and a solenoid coil, is included in the active bushing. This active chamber affects the dynamic stiffness response of the bushing by altering the bushing's internal pressure. The nonlinear equation of motion of the permanent magnet is linearized and is incorporated into the new mathematical model of the system. The new purposed model for the active bushing is in good agreement with the experimental results. This active chamber is also proved capable of producing complex dynamic stiffness frequency response. <br /><br /> The conclusion is that the proposals in this thesis can contribute to the isolation of the vibration pattern, imposed by the application of a VDE system.

In Taiwan, the trading value of electronics related stocks makes up over 60% of Taiwan stock market and has grown gradually to the recent high of 70.03% in Dec. 2009. The high correlation between the TAIEX and TAIEX Electronic Index raises our interest to build a fund aiming to outperform TAIEX Electronic Index performance with similar risk as index by constructing an enhanced fund. We are keen to investigate if active management gain higher return than passive one according to our empirical study. This paper presents a combination effect of multi-factor model in the electronic sector and illiquidity, that expected returns are increasing in illiquidity. The major outcome is that we construct single industry Multi-Factor Model (MFM) and test for its prediction ability. The other is we form a proxy for illiquidity and incorporate it into the multi-factor model using Principal Component Analysis (PCA). The objective of this study is to discover mispriced stocks and make adjustments to build an enhanced fund, targeting 3% tracking error. As a result, the most stable factors based on cumulative return in forecasting electronic sector are Leverage, Value3, ValueToGrowth, EarningQulity respectively. The average explanatory power of electronic multi-factor model (ELE-MFM) is around 52.4% over the sample from 2004/1 to 2009/12. For illiquidity measure, we run cross-regression of stock return on illiquidity and other stock characteristics from the period of 2000/1 to 2009/12. What we find is sub-period is the significant evidence for the work of illiquidity. With the PCA combination of electronic multi-factor model and illiquidity measure into scores coming from the first principal component, we rank stocks through it. With the appropriate constraint rules added into our quadratic programming, the portfolio using the techniques combining multi-factor model and liquidity measures shows IR 0.69, TE 3% and Alpha 2.04% in our sample period. The work of the electronic Multi-Factor Model (MFM) and the illiquidity measure showing satisfactory result support enhanced skills.

Many enhanced index funds are based on a quantitative model to control active risk and to acquire active return. In this thesis we first construct a multiple-factor model (MFM) and then use statistical methods to evaluate the significance and stability of factor explanatory power. Significant and stable factors are utilized to fine tune weights of T50 index fund portfolio by an intuitive weight allocation model to achieve the effect of return enhancement. Empirical studies show that the multiple-factor model can explain the excess stock return effectively; the average R-Square of multiple-factor model reaches 49%. After analyzing the sensitivity of parameter of enhanced index weight allocation, the study finds that the original weight retention rate has linear relationship with active return and active risk of the T50 index fund. Adjusting the retention rate allows us to control the active return and active risk of T50 index fund. Furthermore, adjusting the original weight retention rate according to the Adj-R2 of multiple-risk factor model can effectively improve the stability of active return. The study finds also that the expected rates of return which are calculated by multiple-risk factor model could not differentiate among future performance of the first your guarantee portfolios. Thus, the study adjusts the range of weight allocation to T50 constituent stocks with higher and lower expected return rates. The result shows that this adjustment increased the IR of the enhanced index funds.

Texte remanié de: Dissertation--Graduate School of Social Sciences der Universität Bremen. / Bibliogr. p. 321-345.

This dissertation examines two broad topics -- emission line properties of active galactic nuclei (AGN) and the effect of hands-on, integrated science courses on student understanding of astronomy. To investigate trends in overall properties of emission lines in AGN, we apply principal component analysis (PCA) to the fluxes in the H [beta] - (O III) region of a sample of 9046 spectroscopically-identified broad-line AGN from the Sloan Digital Sky Survey (SDSS) Data Release 5 with a redshift range of 0.1 < z < 0.56. After performing independent spectral PCA on subsets defined effectively by their (O III) equivalent width (EW), we find only the weakest (O III) objects retain the optical Fe II - (O III) anticorrelation and the correlation of EW[subscript O III] with H [beta] linewidth that have previously been found in high-luminosity AGN. The objects with strongest EW[subscript O III] do not differ from the entire data set significantly in other spectral and derived properties, such as luminosity, redshift, emission line shapes, Eddington ratio, continuum slope, and radio properties. However, our findings are consistent with previous suggestions that (O III) emission is primarily a function of covering factor of the narrow-line region. To investigate the other side of the Fe II - (O III) anticorrelation, we examine the effect of changes in the gas-phase abundance of Fe on observed variation in Fe II. Using AGN spectra from the SDSS in the redshift range of 0.2 < z < 0.35, we measure the Fe/Ne abundance of the narrow-line region (NLR) using the (Fe VII)/(Ne V) line intensity ratio. We find no significant difference in the abundance of Fe relative to Ne in the NLR as a function of Fe II/H [beta]. However, the (N II)/(S II) ratio increases by a factor of 2 with increasing Fe II strength. This indicates a trend in N/S abundance ratio, and by implication in the overall metallicity of the NLR gas, with increasing Fe II strength. We propose that the wide range of Fe II strength in AGN largely results from the selective depletion of Fe into grains in the low ionization portion of the broad-line region. We utilize photoionization models to show that the strength of the optical Fe II lines varies almost linearly with gas-phase Fe abundance, while the ultraviolet Fe II strength varies more weakly, as seen observationally. After examining the emission line properties of large samples of fairly typical AGN, we investigated the newly expanded regime of low-mass AGN (M[subscript BH] [less than or approximately equal to] 10⁶ M[subscript sun]) with respect to their emission line properties at a smaller scale. We utilize the high spectral resolution and small aperture of our Keck data of 27 low-mass AGN, taken with the Echellette Spectrograph and Imager, to isolate the NLRs of these low-mass black holes. Some of these low-luminosity objects plausibly represent examples of the low-metallicity AGN described by Groves et al. (2006), based on their (N II)/H[alpha] ratios and their consistency with the Kewley & Ellison (2008) mass-metallicity relation. We also find that these low-mass AGN have steeper UV continuum slopes than more-massive AGN based on their He II/H[beta] ratio. Overall, NLR emission lines in these low-mass AGN exhibit trends similar to those seen in AGN with higher-mass BHs, such as increasing blueshifts and broadening with increasing ionization potential. Additionally, we see evidence of an intermediate line region whose intensity correlates with L/L[subscript Edd] in these objects, as seen in higher-mass AGN. We highlight the interesting trend that, at least in these low-mass BHs, the (O III) EW is highest in symmetric NLR lines with no blue wing. This trend of increasing (O III) EW with line symmetry could be explained by a high covering factor of lower ionization gas in the NLR. We also investigate effective methods for teaching astronomy and connections between astronomical topics in student learning and understanding. After developing the curriculum for a hands-on, learner-centered astronomy course (Hands-on-Science, hereafter HoS) aimed at pre-service elementary teachers, we measure student performance in HoS compared to traditional, large lecture courses (hereafter Astro101). We utilize distractor-driven multiple choice assessments in order to quantitatively assess student understanding and evaluate the persistence or correction of common misconceptions in astronomy. We find that for the topics included in the HoS curriculum, HoS students have a higher average post-test score, and higher normalized gains, than the Astro101 students. We cannot pinpoint the exact cause of this student achievement because of the multitude of nontraditional practices incorporated into the HoS implementation. Increased time-on-task, a classroom environment structured around student discussion, or focus on conceptual understanding could each be key factors in the high achievement of HoS students. We conclude that the HoS students are better prepared in astronomy for their future careers as elementary school teachers by HoS courses than they would have been in traditional, introductory astronomy courses. When we compare directly between topics covered in both HoS and Astro101, we find that HoS students have normalized gains that are a factor of 2-4 higher than those of Astro101 students. Therefore, we conclude that curricula similar to the HoS approach would benefit Astro101 students as well, particularly for topics which are most impacted by the HoS method, such as Moon phases and seasons. Lastly, a PCA of the changes in HoS student scores reveals that there is very little systematic student variation apart from the trends apparent in the mean changes in the sample. Thus, we do not find groupings of questions that some subsets of students systematically learn more readily than others. Another way to interpret this result is that the HoS curriculum and methodology indiscriminately help all kinds of pre-service elementary teachers, despite presumptive differences in their own learning styles and strengths. / text

published_or_final_version / Medicine / Master / Doctor of Medicine