Finite-volume methods have been used for modeling of fluidflows involved in forced convection electrochemical coating androtating spray painting systems. Electrodeposition on a singlecircular cylinder under forced convection for Reynolds numbers10 and 200 was simulated. Comparisons with earlier numericaland theoretical results are presented and it is shown that theunsteady wake that appears for Reynolds numbers greater than 50affects the mass transfer from the surface of the cylinder onlyin an average sense. This result is compared with a heattransfer case, where unsteadiness is much more manifest. Theeffect of application of circulation movement around thecylinder surface was considered, showing that the use ofoptimal values for circulation can create a recirculation zonearound the cylinder and result in a remarkable improvement ofthe deposit uniformity. The magnetoelectrolysis researchdiscipline is presented with focus on magnetic fields uses onmass transfer processes. A classification of the governingdimensionless parameters that control the phenomena isproposed. Application of magnetoelectrolysis on electroplatingprocesses is done for the first time. It is found that the useof an alternating magnetically induced force around thecylinder can result in interesting improvement of quality andproductivity. Application of numerical methods is also studiedin another field of the surface finishing industry, thepainting atomizers. A critical situation of "reverse flow" isanalyzed. Different parameters of this phenomenon are studiedand suggestions for atomizers design are given and tested. <b>Keywords:</b>mass transfer, electrochemical coating, iontransport, forced convection, diffusion, magnetoelectrolysis,electrolyte, limiting current, numerical simulation,finite-volume methods, paint atomization, Coanda effect.

Interactions between light and a molecule can result in reversible or irreversible changes in properties of both the light and the molecule. Of the many known interactions, nonlinear absorption is a process in which an intense light signal, for instance from a laser, can be moderated. This can be manifested either in a marked lowering of the light’s intensity or in reductions in fluctuations of its intensity. Such an effect is often termed ‘optical power limiting’ (OPL). High power lasers can be very dangerous since their high intensity can damage or destroy eyes and optical sensors. However, there are currently no adequate protective measures against lasers that cover the entire visible region and there is an increasing demand for new or improved OPL materials. Some of the most promising optical power limiting materials are substances that combine nonlinear optical properties with high transparency in normal light, but after activation by a laser beam, their light transmittance falls extremely rapidly via so-called self-activating mechanisms. The platinum(II) acetylides comprise one class of compounds with such properties. In this study, various OPL Pt(II) acetylides were synthesized and their nonlinear optical properties were characterized. The emphasis of the work was on preparation of the compounds, but in order to design organoplatinum chromophores for OPL, attempts were also made to obtain insight into the mechanisms of nonlinear absorption. The work was divided into two main parts. In the first the goal was to find compounds that are good optical limiters in solution. The possibility of isolating the chromophore site by dendron shielding and the effects of incorporating a thiophene ring into the organic molecular system were also explored. In addition, a new route for synthesizing these compounds was developed. The second part was focused on incorporating the most interesting compounds into solid materials. The preparation and characterization of Pt(II) acetylides with molecular groups for covalent attachment to a silica matrix via the solution gel approach is described.

The purpose of this naturalistic inquiry was to describe, interpret, and link through voices of parents the lived experience of caring for a child with a lifelimiting and lifethreatening diagnosis within the context of existing social polices. Critical ethnology and Habermas critical theory framework together provided a broad framework from which to delve beneath the surface of everyday appearances and to produce theoretically informed accounts of social phenomena grounded in parents perceptions of caring for children who have palliative care needs. This framework provided the means to deconstruct power structures and relationships to reveal and redress oppression by unlocking silent discourses, emancipating voices, and empowering families. The stories of six parents were captured and presented a critical discourse concerning outcomes of the operationalized welfare state within a liberal paradigm that celebrates the autonomous individual as the appropriate unit of political analysis. <p>Four themes emerged that illuminated and provided a fuller understanding of the lived experiences of parenting a child with a lifelimiting and lifethreatening diagnosis. The initial theme, Mother as Caregiver, described the profound effect that assuming the caregiving role had on the lives of these mothers. The theme, Respite and Coping, explored and identified the overwhelming need for parents to obtain relief through respite, so they could parent better. The third theme, Surviving Past Expectancy, explained how their child, outliving their initial diagnosis, placed yet another new stress and burden on the family. The final theme, Getting Everyone on the Same Page, described frustrations parents experienced on a regular basis trying to find services and then act as coordinator for their child and family.<p>This study provided a unique and valuable optic to an untapped data source, which until now has remained silent. Results demonstrate the significance and meaning of the identified themes and their interrelatedness, and the study concludes with a discussion of the findings and policy implications. The main findings were the untapped resilience and strength of each participant, the uniqueness of each of their stories, and the reality that the harms associated with having a child with a lifelimiting and lifethreatening diagnosis can certainly be lessened through social polices that direct the provision and access to pediatric palliative care services to all who require them. A researchedbased understanding of the lived experience and the contextual nature of parents perceptions provides policymakers, politicians, and health care professionals an opportunity to offer specialized services and programs to children with lifelimiting and lifethreatening diagnosis and their families.

The purpose of this naturalistic inquiry was to describe, interpret, and link through voices of parents the lived experience of caring for a child with a lifelimiting and lifethreatening diagnosis within the context of existing social polices. Critical ethnology and Habermas critical theory framework together provided a broad framework from which to delve beneath the surface of everyday appearances and to produce theoretically informed accounts of social phenomena grounded in parents perceptions of caring for children who have palliative care needs. This framework provided the means to deconstruct power structures and relationships to reveal and redress oppression by unlocking silent discourses, emancipating voices, and empowering families. The stories of six parents were captured and presented a critical discourse concerning outcomes of the operationalized welfare state within a liberal paradigm that celebrates the autonomous individual as the appropriate unit of political analysis. <p>Four themes emerged that illuminated and provided a fuller understanding of the lived experiences of parenting a child with a lifelimiting and lifethreatening diagnosis. The initial theme, Mother as Caregiver, described the profound effect that assuming the caregiving role had on the lives of these mothers. The theme, Respite and Coping, explored and identified the overwhelming need for parents to obtain relief through respite, so they could parent better. The third theme, Surviving Past Expectancy, explained how their child, outliving their initial diagnosis, placed yet another new stress and burden on the family. The final theme, Getting Everyone on the Same Page, described frustrations parents experienced on a regular basis trying to find services and then act as coordinator for their child and family.<p>This study provided a unique and valuable optic to an untapped data source, which until now has remained silent. Results demonstrate the significance and meaning of the identified themes and their interrelatedness, and the study concludes with a discussion of the findings and policy implications. The main findings were the untapped resilience and strength of each participant, the uniqueness of each of their stories, and the reality that the harms associated with having a child with a lifelimiting and lifethreatening diagnosis can certainly be lessened through social polices that direct the provision and access to pediatric palliative care services to all who require them. A researchedbased understanding of the lived experience and the contextual nature of parents perceptions provides policymakers, politicians, and health care professionals an opportunity to offer specialized services and programs to children with lifelimiting and lifethreatening diagnosis and their families.

Algae is regarded as a good potential substrate for biogas production, due to high cells productivity, low cellulose and zero lignin content. Two parts were included in this study: first, cultivations of micro-algae (Chlorella sorokiniana and Tetraselmis suecica) at two different nitrate concentrations, also the effect of addition of CO2 on algae grow was investigated in this first part. Second, batch fermentations of the cultivated micro-algae as well as a powder Chlorella (obtained from Raw Food Shop) and a dry mix filamentous algae (collected in the pounds in the park at the back of the Tema-building and then dried) were performed. In this part also effects of thermo-lime pretreatment (room temperature, 80oC, 105oC and 120oC) on the algae biogas potentials was investigated. Both strains of micro-algae cultured at low nitrate gave more CH4 yield: 319 (±26) mL and 258 (±12) mL CH4 per added gVS was obtained during the degradation of Chlorella sorokiniana grown at 0.4mM-N and 2mM-N level, respectively. For Tetraselmis suecica 337 (±37) mL and 236 (±20) mL CH4 per added gVS was obtained at 2.4mM-N and 12mM-N level, respectively. Powder Chlorella gave the highest biogas production (719 ±53 mL/added gVS) and CH4 yields (392 ±14 mL/added gVS), followed by the dry filamentous algae (661 ±20 mL biogas and 295 ±9 mL CH4 per added gVS) and Tetraselmis suecica (12 mM-N; 584 ±7 mL biogas and 295 ±9 mL CH4 per added gVS). A negative effect of lime treatment at room temperature on CH4 yield of algal biomass was obtained. Lime treatment at 120oC showed the fastest degradation rate for Tetraselmis suecica and powder Chlorella during the initial 5 days of incubation. Chlorella sorokiniana and Tetraselmis suecica cultures flushed with biogas containing 70% and also CO2 enriched air (5% CO2) did not increase cells growth (measured as OD600) if compared to references grown under air. On the contrary, a clearly inhibition effect on the algal cells growth was observed in some cultures.

This thesis presents the applications of a series interconnection scheme for small distributed generation (DG) systems in distribution networks. The concept uses one set of voltage source converter (VSC) to control the injected voltage magnitude and phase angle for power injection and voltage sag mitigation. Through an energy storage device and the VSC, DG outputs vary concurrently with the line loading and provide load leveling functions. Under voltage sag situations, it provides missing voltages to effectively deal with power quality problems. Due to its series connection characteristic, it is convenient in preventing islanding operation and good for fault current limiting. The concept is suitable for locations where the voltage phase shift is not a major concern. Due to the use of only one set of converter, it is economic for customer site distributed energy resource applications and its control strategy would depend on the types of load connected.

The linear relationship between a conservative element and salinity during mixing of water masses is widely used to study biogeochemistry in estuaries and the oceans. Even though nutrient ratios are widely used to determine the limiting nutrient in aquatic environments, the rules of nutrient ratios change through the mixing of freshwater and seawater are still unstudied. This study provides general rules for nutrient ratios change via mixing. A simple mixing model is developed with the aims to illustrate that nutrient ratio is a nonlinear function of salinity, thus, shift in limiting nutrient over the salinity gradient can be simply a result of river water and seawater mixing, albeit complicated by biological consumption or remineralization. This model explains a natural phenomenon that rivers contain relatively high dissolved inorganic nitrogen (DIN) to soluble reactive phosphorus (SRP) ratios start to decrease the ratios as salinity increases when seawater contains higher SRP:DIN ratios. Although additional sources of P have been implicated as the cause for such change, this change can be a result of riverine water and seawater mixing. Four mixing rules are presented here to explain the factors governing the change in nutrient ratios vs. salinity; thus, answering why in some cases variations in nutrient loading and in other cases mixing triggers changes to seasonal limitation status in some estuaries. Shift in nutrient ratios can be explained by the change in nutrient inventories via mixing. After the P-limited riverine water shifts in N limitation by mixing with N-limited seawater, new production of the estuary in general becomes limited by the amount of N inputs from the riverine water and the seawater. The result may help to explain a current consensus that N and not P riverine loadings lead to eutrophication in estuaries which are influenced by P-limited riverine waters. Further, new production which is generated by N-limited riverine input and N-limited seawater input mainly depends on the amount of N inputs from the riverine water and the seawater.

<p>Finite-volume methods have been used for modeling of fluidflows involved in forced convection electrochemical coating androtating spray painting systems. Electrodeposition on a singlecircular cylinder under forced convection for Reynolds numbers10 and 200 was simulated. Comparisons with earlier numericaland theoretical results are presented and it is shown that theunsteady wake that appears for Reynolds numbers greater than 50affects the mass transfer from the surface of the cylinder onlyin an average sense. This result is compared with a heattransfer case, where unsteadiness is much more manifest. Theeffect of application of circulation movement around thecylinder surface was considered, showing that the use ofoptimal values for circulation can create a recirculation zonearound the cylinder and result in a remarkable improvement ofthe deposit uniformity. The magnetoelectrolysis researchdiscipline is presented with focus on magnetic fields uses onmass transfer processes. A classification of the governingdimensionless parameters that control the phenomena isproposed. Application of magnetoelectrolysis on electroplatingprocesses is done for the first time. It is found that the useof an alternating magnetically induced force around thecylinder can result in interesting improvement of quality andproductivity. Application of numerical methods is also studiedin another field of the surface finishing industry, thepainting atomizers. A critical situation of "reverse flow" isanalyzed. Different parameters of this phenomenon are studiedand suggestions for atomizers design are given and tested.</p><p><b>Keywords:</b>mass transfer, electrochemical coating, iontransport, forced convection, diffusion, magnetoelectrolysis,electrolyte, limiting current, numerical simulation,finite-volume methods, paint atomization, Coanda effect.</p>

Transient Recovery Voltage (TRV) is an important consideration in the selection and installation of circuit breakers with appropriate ratings. Capacitor banks with inrush current limiting reactors are an integral part of the power system. Capacitor banks with inrush reactors on the load side terminal of the capacitor breaker alter the TRV seen across the breaker and it is critical to carry out the TRV analysis to prevent circuit breaker failure. TRV analysis has been performed for various capacitor bank - inrush reactor configurations, with the fault occurring at different terminals on the load side. Analytical solutions have been presented for both single-phase and three-phase ungrounded capacitor banks. Neutral displacement voltage of three-phase ungrounded capacitor banks result in increased stress across the breaker. Results have been validated with PSCAD simulation and MATLAB plots. / text

The overall efficiency of photovoltaics is dictated by processes occurring within it. These processes include exciton formation, diffusion, dissociation and charge collection. This dissertation will focus around the fundamental issue of charge collection. In organic photovoltaics (OPVs) the rate of charge injection is dominated by the interaction between dissimilar materials, usually organic compound interacting with inorganic ones. In order to improve this rate of injection and, by direct consequence the efficiency of this process, fundamental knowledge of this organic-inorganic interface must be gained. In this work the focus will reside solely on creating molecules capable of probing the interface between the indium tin oxide (ITO) and the donor layer. At this interface, the usual charge transfer being transferred is the hole. Chapters 2 and 3 detail the synthesis and photophysical characterization of porphyrin-perylene diimide (Por-PDI) and porphyrin-fullerene (Por-C₆₀) molecular dyads. The idea behind these moieties is that covalent attachment of these species to ITO should lead to a robust ohmic contact. Since these molecular dyads are capable of producing charge-separated states after photoexcitation, they should have the capacity to produce a radical-cation in close proximity to the ITO. This will translate to a capacity for probing the dynamics of the hole injection at this interface. Studies performed demonstrate that in fact these dyads are capable of producing a charge-separated state upon photo-excitation. The lifetimes of these states were determine to be 35 ps and 3 ns for the Por-PDI and Por-C₆₀ respectively. Chapter 4 takes a different turn. It is focused on the application and extension of a solvent-free synthesis of metallated phthalocyanines (Pcs). Shown in chapter 4 is the synthesis of a series of metallated Pcs using various transition metals and group 3 elements. Photophysical and electrochemical investigation of these materials shows that they have near-infrared absorption and relative high HOMO levels making them potential candidates for OPV applications. In addition, they displayed non-linear optical behavior due to their highly polarizable pi-systems and the presence of axial susbtituents. Finally Chapter 5 describes the synthesis and characterization of porphyrin possessing rigid linkers. This chapter also shows the further directions in which the various ideas presented in this work could be driven.