A process for micromachining of micro-mirror devices from silicon-on-insulator wafers was proposed and implemented. Test methods and force applicators for these devices were developed. Following successful fabrication of these devices, a novel process for fabrication of devices out of the plane of the silicon wafer was proposed, so that the devices could be actuated electrostatically. In particular, the process makes use of thick photoresist layers as a sacrificial mold into which an amorphous nickel-phosphorous alloy may be deposited. Ideal design of the electrostatically actuated micro-mirrors was investigated, and a final design was selected and modeled using FEA software, which found that serpentine-hinged devices require approximately 33% of the actuation force of their straight-beamed counterparts. An aqueous electroless plating solution composed of nickel acetate, sodium hypophosphite, citric acid, ammonium acetate, and Triton X-100 in was developed for use with the process, and bath operating parameters of 85°C and 4.5 pH were determined. However, this electroless solution failed to deposit in the presence of the photoresist. Several mechanisms proposed for deposition failure included leaching of organic solvents from the photoresist, oxidation of the nickel-titanium seed layer on which the deposition was intended to occur, and nonlinear diffusion of dissolved oxygen in the solution.

<p>The absorption properties of the Pt1 chromophore at room temperature have been studied. Stretch, bend and torsion parameters for Pt(II), P, C (type 1, 2 and 4) and H have been parameterized for use in the MM3 force field. Parameters were fitted to energies computed at the B3LYP level of theory. The parameterized model was used to perform molecular dynamics simulations at room temperature. This was done for several environments and for time periods of up to 200 ps. Absorption properties were computed for snapshots from the dynamics, from which average absorption spectra were created. A conformational broadening of around 40 nm was found in the theoretical spectra, which is in good agreement with experiments. Due to a lack of solvent-solute interactions and the use of a less extensive basis set, a systematic blue shift of 40 nm is evident in the computed spectra.</p>

The present thesis deals with the development of a new type of dynamic model for metallurgical reactors. It also covers some of the theoretical aspects of steelmaking that is necessary to include in such an application. The thesis consists of modeling work, high temperature experiments and cold model experiments. Two different aspects of slags in the oxygen steelmaking were investigated. In the first study, slag samples were equilibrated with copper at 1923K in order to study their capacities in capturing phosphorous. Some of the samples were liquid-solid mixtures. The solid phases in these samples were identified by SEM analysis. The identified phases were found to agree well with Thermocalc calculations while the amount of solid fractions didn’t. The phosphorous distribution between the different phases was examined. The phosphate capacities of the samples were evaluated. The MgO content didn’t show any appreciable impact on the phosphate capacity. Furthermore the activities of FeO in the liquid slag samples were calculated and were found to deviate positively from ideality. In the second study the foaming height of CaO-SiO2-FeO slags by the reaction with hot metal was investigated. It was found that the foaming height increased with increasing FeO content up to 20-25%. The foaming height was seen to decrease with increased viscosity. The present results indicated that simply using foaming index for converter slag might lead to wrong conclusion. Simulation experiments using cold model at room temperature were conducted. Cold model experiments were carried out in order to study the penetration depth due to an impinging gas jet on the surface of a liquid metal. The liquid alloy Ga-In-Sn was used to simulate steel. And an HCl solution was used to simulate the slag. A comparison with predictions of existing models was made and a new model parameter was suggested. The observation of the movement of metal droplets generated by the gas jet was also made. The low velocity of droplets suggested that the turbulent viscosity played important role and the droplets could have long resident time in the slag. Furthermore a study of the effect of gas flow rate on homogenization and inclusion removal in a gas stirred ladle was carried out. Both industrial trials and cold model experiments were conducted. As an auxiliary tool CFD was used to predict the mixing times and was found to agree well with both the model experiments and industrial data. The increase of flow rate of inert gas would not improve the mixing substantially at higher flow rates. The water model study showed also that the gas flow rate had negligible effect on the rate of inclusion removal. Both the experiments and CFD calculation strongly suggested that low gas flow rate should be applied in the ladle treatment. Lastly a new approach to a dynamic process model of 300 ton BOF converter was made. The main feature was to utilize the velocity vectors obtained by CFD simulation. In the standalone model, the steel melt domain was sliced into 1000 cells. Based on the imported velocity vectors from the CFD calculation, the mass transfer of carbon and phosphorus was calculated taking into account the slag metal reactions. The mass exchange between slag and metal was considered to be dominated by the metal droplet formation due to oxygen jet. The convergence of the model calculation and the promising comparison between the model prediction and the industrial data strongly suggested that the proposed approach would be a powerful tool in dynamic process control. However, more precise descriptions of other process aspects need to be included before the model can be practically employed in a dynamic controlling system. / <p>QC 20120829</p>

The absorption properties of the Pt1 chromophore at room temperature have been studied. Stretch, bend and torsion parameters for Pt(II), P, C (type 1, 2 and 4) and H have been parameterized for use in the MM3 force field. Parameters were fitted to energies computed at the B3LYP level of theory. The parameterized model was used to perform molecular dynamics simulations at room temperature. This was done for several environments and for time periods of up to 200 ps. Absorption properties were computed for snapshots from the dynamics, from which average absorption spectra were created. A conformational broadening of around 40 nm was found in the theoretical spectra, which is in good agreement with experiments. Due to a lack of solvent-solute interactions and the use of a less extensive basis set, a systematic blue shift of 40 nm is evident in the computed spectra.

A key part of the development of new polymeric materials focuses on the use of flame-retardant additives, which help to reduce the inherent flammability of polymers and the production of smoke and toxic gases. The aim of this thesis was the preparation, characterization and application of new polymeric flame-retardant additives, which can lead to intumescent systems when mixed with ¨commodity¨ polymers. The synthesis of this kind of additives was carried out by chemical modification of different polymeric structures (alcohols, polyketones, polyaziridines) with phosphorous moieties, previously described as promoting flame retardance structures, and/or nitrogen containing moieties. The efficacy of some of these additives was tested by blending with polypropylene, one of the most commonly used thermoplastic. Flame retardancy behaviour of the blends, as well their compatibility and mechanical properties were studied, in order to observe how the flame retardant additives may affect the substrate properties. / Una parte fundamental del desarrollo de nuevos materiales poliméricos se centra en la utilización de agentes retardantes a la llama, los cuales contribuyen a reducir la inherente combustibilidad de los polímeros y la producción de humos y de gases tóxicos. El objetivo del presente trabajo ha sido la preparación, characterización y aplicación de nuevos aditivos retardantes a la llama de tipo polimérico que pueden dar lugar al mezclarse con polímeros termoplásticos de gran consumo a sistemas de tipo intumescente. La síntesis de estos additivos se ha llevado a cabo por modificación química de diferentes estructuras polimericas (alcoholes, policetonas, poliaziridinas) con compuestos fosforados, descritos previamente como promotores de retardancia a la llama y/o compuestos con nitrogeno. La eficacidad de algunos de estos additivos ha sido estudiada por mezclarse con polipropileno, uno de los más utilizados termoplasticos.

In connection with Henriksdals wastewater treatment plant (WWTP) a smaller plant is situated called Sjöstadsverket where new methods for wastewater treatment are tested and evaluated in different process lines. On one of the lines experiments with enhanced biological phosphorous removal (EBPR), have been carried out to evaluate if it is a good alternative to traditional chemical phosphorus removal. This thesis evaluates the results from the experiments conducted during fall 2005. The incoming water from Hammarby Sjöstad consists of only household wastewater, which gives a wastewater with high concentrations of nutrients and organic carbon. This is partly positive, because one of the limiting factors for effective biological phosphorus removal is the lack of easily biodegradable organic carbon. The high concentrations of ammonium and phosphorus demand a high reduction to achieve the requirements of outgoing concentration. To optimize the process experiments with different recirculations and different aeration techniques have been made. The experiments have shown that it is possible to obtain good results, with periods of very low outgoing phosphorus concentrations below 0,15 mg/L. It was, however, hard to obtain a stable process and to keep a good sludge quality during the period. Primary sludge was hydrolysed to increase the amount of easily degradable organic material into the biological step of the process. The hydrolyse had a high efficiency during the test period, but with big variations. The most desirable fraction of organic material, VFA, increased to approximately 1500 mg/L during the best periods. This is only 9 % of the amount VFA in the primary sedimentation, but could be increased with a higher flux. When the bioP sludge is fermented as a part of sludge treatment, a supernatant from digester sludge with high concentrations of phosphorus is received. To avoid to return phosphor into the activated sludge process and to recycle phosphorus, experiments with phosphorus precipitation were made. By using struvite precipitation up to 92 % of the phosphorus in the supernatant was reduced and precipitated. This was 12 % of the total amount of incoming phosphourus and was achieved at a pH just over 9 in the experiment tank and a Mg:P quote of 1:1. / I anslutning till Henriksdal’s reningsverk ligger Sjöstadsverket som är ett mindre reningsverk där nya reningsmetoder testas och utvärderas i på ett antal olika försökslinjer. På en av linjerna har försök med biologisk fosforrening, även kallat BioP, utförts för att undersöka om det är ett alternativ till konventionell kemisk rening av fosfor. Detta arbete sammanfattar resultaten från de experiment som utförts under hösten 2005. I Hammarby Sjöstad, som förser Sjöstadsverket med avloppsvatten, separeras dag och spillvatten, vilket bidrar till ett näringsrikt vatten med en hög halt organiskt material. Detta är delvis positivt, då en av de begränsande faktorerna för en effektiv biologisk fosforrening är bristen på lättillgängligt organiskt material. De höga halterna inkommande fosfor och kväve kräver dock en högre reningsgrad för att de stränga utsläppsmålen ska nås. För att optimera processen har försök med olika inställningar på recirkulationsgrader genomförts och försök med olika luftningsstrategier. Försöksperioden har visat att det går att få mycket bra resultat, med periodvis utgående fosfathalter under 0,15 mg/L. Det har dock varit svårt att få en stabil process och behålla en bra slamkvalitet under hela försöksperioden. Primärslam från försedimenteringen har hydrolyserats för att öka mängden lättillgängligt organiskt material in till det biologiska reningssteget. Hydrolysen fungerade bra under hela försöksperioden, dock med stora variationer. Den mest önskvärda fraktionen lättillgängligt organiskt material, VFA, hade under de bästa perioderna ökat till ca 1500 mg/L i hydrolysen. Detta utgör approximativt 9 % av mängden VFA i försedimenteringen, men skulle kunna ökas vid ett större flöde. Då BioP-slammet rötas som en del av slambehandlingen fås ett fosforrikt rejektvatten. För att undvika att få in fosfor till aktivslamprocessen och för att ta till vara på fosfor som näringsämne har försök med fosforåtervinning från rejektvatten gjorts. Genom att använda sig av struvitfällning kunde upp till 92 % av fosforn i rejektvattnet reduceras och fällas ut. Detta motsvarar 12 % av den totala inkommande fosforhalten och uppnåddes vid pH strax över 9 i struvitfällningstanken och med en Mg:P kvot på 1:1.

Phosphorous (P) has been found to be the limiting nutrient in freshwater systems, directly affecting rates of planktonic growth. The P circulation is very complex, and its pathways through lake systems are difficult to determine. Motala Ström is the biggest watercourse in the south-east of Sweden and an important source of P to the Baltic Sea. The aim of this study is to conduct a P mass balance analysis of the lakes Roxen and Glan over a period of time. The analysis will also include a quality control of the concentrations data. The P concentration data used in this investigation were collected from the Motala Ström River Association, consisting of seasonal or monthly concentration data of Tot-P during the period 1960-2010. Daily water flow data used in this study were modelled by the Swedish Meteorological and Hydrological Institute (SMHI) using the S-HYPE model. P concentration deviations from monthly averages at each sampling station were calculated, followed by a seasonal Mann Kendall trend analysis. At five out of eight sampling stations, negative trends were detected, indicating decreasing concentrations. The exception was the outflow from lake Glan, Stångån and Finspångsån. Linear interpolation of P concentration data was performed to create daily data for the period 1980-2010. Following interpolation, daily transport values were calculated and summed up to annual values. Lake Roxen has acted as a source of P during the whole period 1980-2010, except for one year. Lake Glan has acted as a source during 22 of the 31 years. There is a tendency of Glan to become more of a source over the years, which is in line with the deviation observations, but variation between years makes it necessary to analyse also future data in order to establish any possible trend in P transports. Before construction of wastewater treatment plants, the lakes were certainly sinks of phosphorus. But at least for Roxen, the switch from sink to source was completed before 1980.

I denna studie har funktionen hos sju anlagda våtmarker för behandling av avloppsvatten i Sverige jämförts över tid med avseende på avskiljning av kväve, fosfor och BOD. Syftet var att undersöka våtmarkernas långsiktiga funktion, skötselåtgärder och relaterade kostnader. Våtmarkerna (1,6 - 28 ha stora) har varit i drift olika länge, mellan 7 och 17 år, och befintliga övervakningsdata samt intervjuer med ansvariga för respektive våtmark användes som grund för studien. Resultaten visade att våtmarkernas reningsfunktion generellt sett varit god utan någon tendens till en försämrad funktion över tid. Våtmarkerna belastades med 1100 - 9900 kg N/ (ha·år) och avskiljde mellan 420 och 2400 kg N/ (ha·år), beräknat som ett medelvärde per anläggning. Belastningen av fosfor var 17 - 145 kg P/ (ha·år) med en avskiljning på 10 - 110 kg P/ (ha·år). En linjär regressionsanalys visade att en högre fosforbelastning också gav en högre avskiljning. Sambandet var svagare för kväve, vilket indikerar att andra faktorer också var viktiga för kväveavskiljningen. Problem med fosforsläpp i våtmarkerna observerades bara där fosforfällning i reningsverken skett med järnbaserad kemikalie, och verkade vara förknippade med tidvisa anaeroba förhållanden i sedimenten. Utgående halter av BOD7 låg på &lt; 5,0 mg/l för alla våtmarker trots stora skillnader i inkommande halt. Kostnaderna för avskiljningen i våtmarkerna var 30 - 190 kr per kg avskilt kväve och 0 - 4700 kr per kg avskilt fosfor. Storleken på kostnaderna var beroende av investeringskostnaden och den årliga driftkostnaden samt hur kostnaden fördelades mellan kväve och fosfor. / In this study, seven constructed free water surface wetlands for wastewater treatment in Sweden were compared, regarding the removal of nitrogen, phosphorous and BOD. The aim was to investigate the long term function, management needs, related costs and look into uncertainties regarding the risk for phosphorous release. The seven wetlands (1.6 - 28 ha) have been in operation for 7-17 years and existing monitoring data were used along with interviews with the staff responsible for the operation. All wetlands performed satisfactorily and there were no indications of a reduced treatment capacity over time. On average, the wetlands received 1100 to 9900 kg N / (ha·yr) and removed 420 to 2400 kg N / (ha·yr). The phosphorous loads varied between 17 and 145 kg P / (ha·yr) and the removal between 10 and 110 kg P / (ha·yr). A linear regression showed that a higher phosphorous load resulted in a higher removal rate. For the removal of nitrogen the linear relationship was weaker, indicating that other factors also were important. Release of bound phosphorous occurred occasionally in wetlands after WWTP using iron based phosphorous precipitation chemicals, and seemed associated with periods when sediments became anaerobic. Effluent concentrations of BOD were &lt; 5.0 mg/l despite varying inflow concentration, and seemed to reflect a background concentration. The costs for the wetland treatment varied between 30 and 190 SEK per kg N removed and between 0 and 4700 SEK per kg P removed. The size of the costs was dependent on investment and management costs as well as how the cost was distributed between nitrogen and phosphorous.

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The Upper North Bosque River (UNBR) watershed is under a Total Maximum Daily Load (TMDL) mandate to reduce Phosphorus (P) due to excess nutrients in the watershed. To address these problems, Texas A&M University researchers have developed a turfgrass sod Best Management Practice (BMP) to remove excess nutrients from impaired watersheds. Turfgrass harvest of manure fertilized sod removes a thin layer of topsoil with most of the manure applied P. Plot and field scale research has demonstrated the effectiveness of turfgrass to remove manure phosphorus (P). In order to assess the impact of the turfgrass BMP on a watershed scale, the Soil and Water Assessment Tool (SWAT) was used to predict water quality in the UNBR watershed. The SWAT model was modified to incorporate turfgrass harvest routines to predict manure and soil P export through turfgrass sod and soil during harvest. SWAT simulations of the BMP predicted stream load reductions of 20 to 36% for P loads in the UNBR depending on the implementation scenario, an average reduction of 31% for total N and 16.7% for sediment for all the scenarios, at the watershed outlet. The SWAT model also predicted up to 176 kg/ha P removed per sod harvest when fertilized with 100 kg manure P/ha, and 258 kg/ha of P removed per sod harvest when the manure P application rate was 200 kg/ha. In addition, depending on the implementation scenario, the turfgrass BMP could export between 262 and 784 metric tons of P out of the UNBR watershed every year. Manure fertilized turfgrass has the advantage of slow releasing nutrients from the composted dairy manure, so it would not require any additional P for life. This means reduced urban non-point source pollution and lower maintenance cost compared to regular sod. These modeling simulations complement the wealth of research that shows the effectiveness of the turfgrass BMP.