<p>GE Healthcare operates in Uppsala (Sweden) and develops systems, equipments and medium to purify medical substances. Discussions with the local authority concerning planed far-reaching changes and upgrades of the biological process techniques for sewage management, aroused the question about revising the terms of permit for the activity. Therefore it seemed necessary to evaluate a newly installed biological process technique, which is the background of this thesis. The evaluated biological treatment process was built in 2003 and consists of a biological reactor filled with moving bed carriers with a high surface area for biological growth. At the time of the project the biological wastewater treatment plant consisted of a flow equalization facility and two following parallel biological processes; a biological reactor with moving bed carriers and a tower trickling filter.</p><p>The aim of this thesis was to survey the function of the biological reactor with respect to the reduction of organic matter. Further to clarify which circumstances that have a negative effect on the organic reduction. During the three forthcoming years, an extensive reconstruction of the biological wastewater treatment facility will be accomplished. During the construction period the flow equalization will be very limited. Therefore an emission forecast with respect to organic matter was performed comprising the construction period during the years 2005, 2006 and 2007. This to estimate the safety margin to the emission standard during the construction period.</p><p>Several parameters were surveyed during the project, water temperature, pH, plural nutrition elements, flow, oxygen concentration, suspended solids, organic load and microbial activity. At two occasions, the parameters were extensively studied during a 24-hour period respectively. Two capacity experiments were performed in order to evaluate the organic reduction at different organic loads. The obtained results together with an estimation regarding the organic load performed by AB Ångpanneföreningen were used for the emission forecast. The forecast considered two cases, operation with and without dosage of a flow with high organic content from the local solvent recycling facility (called T10-dosage).</p><p>According to the forecast, the emission standard will be fulfilled during an average month regarding the organic load. This without T10-dosage and with an average reduction of 55 %. To fulfill the standard during a month with maximum organic load, a reduction of 65 and 75 % will be required in the cases without and with T10-dosage respectively. The organic reduction is negatively effected by lasting loads of 7 kg CODfilt/m3 or higher, or by a great increase of the load in a short period of time. Sporadic peaks regarding the organic load appeared to have temporary or no negative effects on the reduction. Flow variations during evenings, nights and weekends caused variations in the organic load with negative effect of the reduction rate. The oxygen concentration in the biological reactor has a conclusive significance of the reduction rate, a lower concentration than 2 mg/l affects the reduction rate in a negative way. The buffering capacity in the biofilm reactor showed to work excellently, the pH value varied between 6.8 and 8.9. There is an immediate risk of temperatures over 40^oC during the construction period. This could have a negative influence of the organic reduction. Individual measured temperatures of 38^oC did not have a negative effect on the reduction rate. The amount of suspended solids varied a lot in the outflow from the biological reactor and will continue to do so during the construction period.</p> / <p>GE Healthcare bedriver sin verksamhet i Uppsala vilken består av att utveckla system, utrustning och media för att rena läkemedelssubstanser. Vid diskussion med Uppsala kommuns VA- och avfallskontor väcktes frågan angående omprövning av tillståndet för verksamheten. Diskussionerna rörde planerade processförändringar och kompletteringar av bolagets biologiska processavloppsvattenrening. Av den anledningen ansågs det nödvändigt att utreda en för företaget ny processteknik för processavloppsvatten, vilket är bakgrunden till detta examensarbete. Den utvärderade processtekniken är en biofilmreaktor innehållande ett rörligt bärarmaterial med en stor skyddad yta för biologisk tillväxt. Biofilmreaktorn togs i drift under hösten år 2003 och därmed bestod det lokala reningsverket förenklat sett av en utjämningsanläggning följd av två parallella biosteg, ett biotorn med konventionell stationär biobädd över vilken processavloppsvatten spreds samt en biofilmreaktor med rörligt bärarmaterial.</p><p>Syftet med examensarbetet var att kartlägga biofilmreaktorns funktion med avseende på reduktion av organiskt material. Vidare att klargöra vid vilka förhållanden reduktionsgraden har påverkats negativt. Under de tre kommande åren skall en stor om- och tillbyggnad av reningsverket genomföras. Förändringen kommer att medföra att utjämningsvolymen blir mycket begränsad under ombyggnadsperioden. Av den anledningen var ytterligare ett syfte med examensarbetet att utföra en utsläppsprognos med avseende på organiskt material för åren 2005 till och med 2007. Detta för att bedöma säkerhetsmarginalen till utsläppsvillkoret under ombyggnadsperioden.</p><p>Examensarbetet realiserades genom att kartlägga parametrarna organisk belastning, organisk reduktion, vattentemperatur, pH, närsalter, flöde, koncentration löst syre, suspenderad substans samt mikrobiell aktivitet. Därutöver utfördes två kapacitetsförsök för att kartlägga den organiska belastningens inverkan på reduktionen. Vid det ena försöket skapades en högre organisk belastning genom att successivt öka flödesbelastningen över biofilmreaktorn. Vid det andra försöket doserades en delström (kallad T10-dosering) innehållande rester från den lokala lösningsmedelsåtervinningen med stort organiskt innehåll. Därtill utfördes två dygnsprovtagningar för att kartlägga ett flertal parametrars dygnsvariationer. Den framtagna utsläppsprognosen baserades på en belastningsprognos utförd av AB Ångpanneföreningen samt den i arbetet kartlagda reduktionen av organiskt material vid olika belastningar. Prognosen omfattar två fall, med eller utan T10-dosering.</p><p>Enligt utsläppsprognosen kommer utsläppsvillkoret inte att överskridas under åren 2005 till och med 2007. Detta gäller vid en för året genomsnittlig månad avseende belastning utan T10-dosering och med en genomsnittlig organisk reduktionsgrad på 55 %. Under en månad med maximal belastning krävs 65 % reduktion och 75 % med T10-dosering. Kapacitetsförsöken visade att reduktionsgraden påverkades negativt vid en varaktig belastning överstigande 7 kg COD_löst/m3 samt vid kraftiga belastningsökningar. Tillfälliga belastningstoppar hade endast kortvarig eller ingen negativ inverkan på reduktionen. Höga flöden under dagtid och låga flöden under nätter och helger orsakade variationer i den organiska belastningen, vilket hade en negativ inverkan på reduktionen. När koncentrationen löst syre i biofilmreaktorn understeg 2 mg/l påverkades mikroorganismerna negativt och därmed även reduktionen. Buffertkapaciteten i biofilmreaktorn var god under den studerade tidsperioden och pH-värdet varierade mellan 6,5 och 8,8. Under ombyggnadsperioden föreligger en stor risk för att vattentemperaturen kan bli för hög i biofilmreaktorn vid ett flertal tillfällen. Enstaka uppmätta temperaturtoppar på 38°C påverkade dock inte reduktionen negativt. I biofilmreaktorns utgående vatten varierade mängden suspenderad substans kraftigt, vilket även kommer att gälla under ombyggnadsperioden.</p>

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IEEE 802.11n Wireless Local Area Networks (WLANs) employ Multiple-Input-Multiple-Output (MIMO), which significantly boosts the raw data rate at the Physical layer (PHY). But the potential of enhancing Medium Access Control (MAC) layer efficiencies by MIMO is still in its early stage and is the aim of the research in this thesis. Many existing works in this field mainly employ distributed MIMO spatial multiplexing/Multi-User Detection (MUD) technique and stream sharing to enable multiple simultaneous transmissions. Most works require synchronization among multiple transmissions, split the channel, and aim for single-hop networks. In this thesis, a novel Hybrid Carrier Sense (HCS) framework is proposed, mainly at the MAC layer to exploit the power of MIMO. HCS senses the channel availability jointly by the virtual carrier sense and physical carrier sense. HCS does not require synchronization among nodes; each node independently and locally determines when to start its transmission. HCS not only shares the channel, but also exploits the bi-directional handshakes of the wireless transmissions and increases the number of simultaneous stream transmissions. For a network with M antennas in each node, HCS can accommodate 2x(M-1) streams instead of M streams achieved by all other existing works. Moreover, HCS is aimed for multi-hop wireless ad hoc networks, in which the hidden terminal, exposed terminal, and deafness problems greatly degrade network performance. The HCS framework incorporates solutions to these problems. HCS is implemented in an NS2 network simulator and the performance evaluation shows that HCS significantly outperforms MIMO-enabled IEEE 802.11 (in which MIMO is only used for enhancing the raw data rate in the physical layer), resulting in higher aggregate throughput, packet delivery ratio and fairness in multi-hop wireless ad hoc networks. The HCS framework will be in wide use in the future generation of wireless networks and opens up more research possibilities. Some ideas in the HCS framework can be applied not only for MIMO, but also for many other techniques surveyed in this thesis; or we may combine them with HCS to further boost the network performance. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2013-10-15 21:46:15.983

Konjuguotieji polimerai kaip funkcinės medžiagos gali būti panaudoti įvairiuose prietaisuose: organiniuose šviestukuose, organiniuose lauko tranzistoriuose, organiniuose saulės elementuose. Šio darbo tikslas - nustatyti fotogeneruotų krūvininkų pernašos dėsningumus π – konjuguotuose polimeruose panaudojant naują žadinimo-zondavimo metodą pagrįstą išoriniu elektriniu lauku indukuota antrosios optinės harmonikos generacija. Pagrindinis dėmesys buvo skiriamas pernašos dinamikai. Molekulinių darinių fizikos laboratorijoje buvo įrengta matavimų schema ir įvertintas metodo tinkamumas krūvio pernašos tyrimams. Buvo atlikti krūvio pernašos matavimai trijuose skirtinguose konjuguotuosiuose polimeruose. Nustatyta, kad fotogeneruotų krūvininkų judris tuoj po sužadinimo yra daug didesnis lyginant su stacionaria judrio verte, o krūvio pernašos dinamiką lemia konjuguoto polimero struktūrinė hierarchija, krūvininkų judėjimas yra daugialypis, susidedantis iš greito judėjimo viena polimero grandine ar konjuguotais polimero grandinės segmentais ir lėto šokavimo tarp atskirų polimero grandinių Pirmą kartą detaliai išnagrinėta šviesa sugeneruotų krūvininkų pernašos dinamika konjuguotuose polimeruose. Darbo rezultatai suteikia žinių apie fundamentalius krūvininkų pernašos mechanizmus konjuguotuose polimeruose, kurios gali būti panaudotos kuriant organinius elektronikos prietaisus. / Conjugated polymers are promising candidates for applications in all kinds of organic optoelectronic devices: OLEDs, organic field-effect transistors (OFETs) and organic photovoltaic cells. The main goal of this work was to investigate transport features of photogenerated electrical charge in pi-conjugated polymers by means of novel technique based on time-resolved electric field-induced second harmonic generation (TREFISH). TREFISH measurement setup was implemented in the laboratory of Molecular compounds physics, and applicability of the method has been verified. Measurements were performed on three different model polymers: methyl substituted ladder-type poly(para-phenylene) (MeLPPP), poly(fluorene-co-benzothiadiazole) (F8BT) and poly(spirobifluorene-co-benzothiadiazole) (PSF-BT), having different morphological and chemical structure. It has been found that motion of photogenerated charge carriers in π-conjugated polymer films experiences rapid dynamics after excitation. Different time domains of charge transport were distinguished. Initial fast transport of photogenerated charge carriers corresponds to the carrier motion along the single polymer chain or conjugated segment of the polymer chain. Slowest carrier motion phase is well described by the stochastic drift, which is attributed to interchain jumps and determines the macroscopic equilibrium mobility. Thus, the equilibrium mobility value is not applicable to the transport on nanometer scale up to tens of nanometers... [to full text]

The doping concentration and resistivity of tin doped Gallium arsenide nanowires (GaAs NWs) have been investigated using Hall effect-, 4-probe-, transmission line-, and field effect measurements. Single nanowires were contacted using electron beam lithography followed by thermal evaporation of Au/Ti (900/100 Å). The Sn precursor (TESn) molar ratios of the investigated nanowires were 8.5·10-7, 1.7·10-6, 3.4·10-6 and 6.8·10-6 resulting in doping concentrations ranging from 4.64·1013 to 2.11·1017 cm-3 and resistivities from ~0.01 to ~1 Ωcm. The yield of the device fabrication was 2.4-7.1 % and evaluation of additional samples should be done in order to establish the validity of the results. The contact material was proved to work well with the higher doped samples but non-ohmic, highly resistive behavior was seen in the lower doped devices. A resistivity gradient along the length of the nanowires was found to be present, most likely the result of a doping gradient. The sample series with TESn molar ratio 1.7·10-6 showed more tapering than the other series possibly leading to a highly doped shell, which was indicated by 4-probe measurements.

Wireless sensor networks has been one of the major research topics in recent years because of its great potential for a wide range of applications. In some application scenarios, sensor nodes intend to report the sensing data to a far-field destination, which cannot be realized by traditional transmission techniques. Due to the energy limitations and the hardware constraints of sensor nodes, distributed transmit beamforming is considered as an attractive candidate for long-range communications in such scenarios as it can reduce energy requirement of each sensor node and extend the communication range. However, unlike conventional beamforming, which is performed by a centralized antenna array, distributed beamforming is performed by a virtual antenna array composed of randomly located sensor nodes, each of which has an independent oscillator. Sensor nodes have to coordinate with each other and adjust their transmitting signals to collaboratively act as a distributed beamformer. The most crucial problem of realizing distributed beamforming is to achieve carrier phase alignment at the destination. This thesis will investigate distributed beamforming from both theoretical and practical aspects. First, the bit error ratio performance of distributed beamforming with phase errors is analyzed, which is a key metric to measure the system performance in practice. We derive two distinct expressions to approximate the error probability over Rayleigh fading channels corresponding to small numbers of nodes and large numbers of nodes respectively. The accuracy of both expressions is demonstrated by simulation results. The impact of phase errors on the system performance is examined for various numbers of nodes and different levels of transmit power. Second, a novel iterative algorithm is proposed to achieve carrier phase alignment at the destination in static channels, which only requires one-bit feedback from the destination. This algorithm is obtained by combining two novel schemes, both of which can greatly improve the convergence speed of phase alignment. The advantages in the convergence speed are obtained by exploiting the feedback information more efficiently compared to existing solutions. Third, the proposed phase alignment algorithm is modified to track time-varying channels. The modified algorithm has the ability to detect channel amplitude and phase changes that arise over time due to motion of the sensors or the destination. The algorithm can adjust key parameters adaptively according to the changes, which makes it more robust in practical implementation.

The multidrug resistance associated proteins (MRP(human)Mrp (rat) are ATP-dependent transporters responsible for the efflux of a wide range of substrates, including endogenous compounds e.g. bilirubin, drug metabolites e.g. paracetamol glucuronide and fluorescent dyes e.g. 5 (and 6)-carboxy-2’,7’-dichlorofluorescein (CDF). Mrp1-6 (<i>abccl-6)</i> are expressed in rat liver, with Mrp2 being expressed at the highest level. Isolation of hepatocytes by <i>in situ</i> collagenase perfusion causes bile canalicular disruption and internalisation of Mrp2. Cells cultured in a sandwich configuration of Matrigel or collagen (Type 1) showed bile canalicular reformation at different days in cell culture, depending on the extracellular matrix and time of overlay. We have developed a method for quantifying Mrp-mediated efflux in hepatocytes cultured in a sandwich configuration of collagen (Type 1). This method is unique in its ability to distinguish between sinusoidal efflux, canalicular efflux and diffusion in intact hepatocytes. Alternative <i>in vitro</i> models of Mrp2-mediated efflux include the vesicular (direct and indirect methods) and the ATPase assays. We have used these assays to identify atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin as substrates of human and rat MRP2/Mrp2. A close correlation was seen between the kinetic parameters of transport of the Mrp2 substrate; CDF determined in sandwich cultured rat hepatocytes using the method above (Km = 3.5 – 9.9 μM), vesicle preparations (Km = 37.9 μM) and membrane preparations (Km = 18.7 μM). We also present data to implicate the nuclear receptors, PXR, CAR and FXR in the regulation of <i>abcc2</i> and <i>abcc3</i> and PXR and CAR in <i>abcc1</i> gene regulation. <i>Abcc2 </i>and abcc5<i> </i>are also up-regulated in response to a toxic insult to the cell, probably via Nrf2 activation, suggesting a role in cell defence.

The relatively high level of palmitic acid (22 mol%) in cottonseeds may be due in part to the activity of a palmitoyl-acyl carrier protein (ACP) thioesterase (PATE). In embryo extracts, PATE activity was highest at the maximum rate of reserve accumulation (oil and protein). The cotton FatB mRNA transcript abundance also peaked during this developmental stage, paralleling the profiles of PATE enzyme activity and seed oil accumulation. A cotton FatB cDNA clone was isolated by screening a cDNA library with a heterologous Arabidopsis FatB probe (Pirtle et al., 1999, Plant and Cell Physiology 40: 155-163). The predicted amino acid sequence of the cotton PATE preprotein had 63% identity to the Arabidopsis FatB thioesterase sequence, suggesting that the cotton cDNA clone probably encoded a FatB-type thioesterase. When acyl-CoA synthetase-minus E. coli mutants expressed the cotton cDNA, an increase in 16:0 free fatty acid content was measured in the culture medium. In addition, acyl-ACP thioesterase activity assays in E. coli lysates revealed that there was a preference for palmitoyl-ACP over oleoyl-ACP in vitro, indicating that the cotton putative FatB cDNA encoded a functional thioesterase with a preference for saturated acyl-ACPs over unsaturated acyl-ACPs (FatA). Overexpression of the FatB cDNA in transgenic cotton resulted in elevated levels of palmitic acid in transgenic somatic embryos compared to control embryos. Expression of the anti-sense FatB cDNA in transgenic cotton plants produced some plants with a dwarf phenotype. These plants had significantly smaller mature leaves, all with smaller cells, suggesting that these plants may have less palmitic acid available for incorporation into extraplastidial membrane lipids during cell expansion. Thus manipulation of FatB expression in cotton directly influenced palmitic acid levels. Collectively, data presented in this dissertation support the hypothesis that there indeed is a palmitoyl-ACP thioesterase in cotton, encoded by the isolated FatB cDNA, which plays a major role in regulating palmitic acid content of extraplastidial complex glycerolipids. This work forms the basis for future studies of the influence of palmitic acid content on plant membrane function and provides a key target for the metabolic engineering of palmitic acid levels in storage oils of developing cottonseeds.

Nouveaux polymères avec une structure arborescente unique, les dendrimères suscitent un grand intérêt auprès des chercheurs de tous les domaines scientifiques confondus et spécialement auprès des biologistes. Théoriquement synthétisés de façon à ce qu’ils soient parfaitement mono disperses en taille et en masse et de forme sphérique, les dendrimères PAMAM ont des propriétés structurales qui pourraient donner de bons résultats lors de leur utilisation comme vecteurs de médicaments ou d’acides nucléiques.De récentes études biologiques ont montré que les dendrimères PAMAM pouvaient transfecter un grand nombre de cellules de différente nature. Les propriétés structurales et physicochimiques du dendrimère joueraient un rôle essentiel dans l’efficacité de cette transfection et pouvoir prédire ces propriétés permettraient de mieux contrôler le comportement de ces«vecteurs-médicaments» dans l’organisme / In the context of securing clinical gene transfer, new strategies are developed with the creationof synthetic gene vectors based on cationic polymers to replace commonly used viral vectors ingene therapy. PAMAM dendrimers are highly branched macromolecules with controlled nearmonodisperse three-dimensional architecture emanating from a central core. Polymer growthstarts from a central core molecule and growth occurs in an outward direction by a series ofpolymerisation reactions. Hence, precise control over size can be achieved by the extent ofpolymerisation, starting from a few nanometers. Cavities in the core structure and folding of thebranches create cages and channels. The surface groups of dendrimers are amenable tomodification and can be tailored for specific applications. Therapeutic and diagnostic agents areusually attached to surface groups on dendrimers by chemical modification.Recent biological studies have shown that PAMAM dendrimers could transfect a large numberof cells of different nature. The structural properties and physico-chemical properties ofdendrimer play a key role in the efficiency of transfection and to predict these properties wouldbetter control the behavior of these "drug delivery systems in the body.