The summing amplifier and the quantizer form two of the most critical blocks in a continuous time delta sigma (CT ΔΣ) analog-to-digital converter (ADC). Most of the conventional CT ΔΣ ADC designs incorporate a voltage summing amplifier and a voltage-mode quantizer. The high gain-bandwidth (GBW) requirement of the voltage summing amplifier increases the overall power consumption of the CT ΔΣ ADC. In this work, a novel method of performing the operations of summing and quantization is proposed. A current-mode summing stage is proposed in the place of a voltage summing amplifier. The summed signal, which is available in current domain, is then quantized with a 3-bit current mode flash ADC. This current mode summing approach offers considerable power reduction of about 80% compared to conventional solutions [2]. The total static power consumption of the summing stage and the quantizer is 5.3mW. The circuits were designed in IBM 90nm process. The static and dynamic characteristics of the quantizer are analyzed. The impact of process and temperature variation and mismatch tolerance as well as the impact of jitter, in the presence of an out-of-band blocker signal, on the performance of the quantizer is also studied.

A flash lighting circuit with the fluorescent lamp is designed to produce lighting flicker by means of controlling the operating frequency and the duty-ratio of the lamp voltage and current. The intensity of the flash lighting is adjusted by the DC-link voltage of the electronic ballast circuit. The circuit structure is mainly composed of the class-D series-resonant inverter, the full-bridge rectifier, the LC filter and the commutation circuit. A control circuit with complex programmable logic device (CPLD) is used to accomplish the regulation of the operating frequency and the duty-ratio, which should be carefully controlled to ensure a stable lighting arc. In the meantime, a flash lighting detected circuit is designed to transform the flash lighting into a voltage signal. Experiment tests are conducted to human visual perception to demonstrate the applicability of the flash lighting circuit.

In this study the data taken from Outokumpu type Flash smelter of Eti-Bakir Plant (Samsun, Turkey) was used to write a computer program in Visual Basic with interface to Excel. Flash smelting is the pyrometallurgical process for smelting metal sulfide concentrates, used in Eti-Bakir plant. In this plant, copper flash smelting consists of blowing fine, dried copper sulfide concentrate mixtures, silica flux, lignite with air into the furnace and natural gas as main fuel. The molten matte is the principal product of the furnace and slag contains 0.5-2% Cu. It is sent to a slag treatment (flotation) process for Cu recovery. This flash furnace off-gas contains from 8-12 volume % SO2 which is fixed as H2SO4. Written program was used to optimize the consumption of oxygen enriched air, fuel and lignite in this Flash Smelter by making material and heat balance of the plant.

Hard disk drive applications require a high Spurious Free Dynamic Range (SFDR), 6-bit Analog-to-Digital Converter (ADC) at conversion rates of 1GHz and beyond. This work proposes a robust, fault-tolerant scheme to achieve high SFDR in an av- eraging flash A/D converter using comparator chopping. Chopping of comparators in a flash A/D converter was never previously implemented due to lack of feasibility in implementing multiple, uncorrelated, high speed random number generators. This work proposes a novel array of uncorrelated truly binary random number generators working at 1GHz to chop all comparators. Chopping randomizes the residual offset left after averaging, further pushing the dynamic range of the converter. This enables higher accuracy and lower bit-error rate for high speed disk-drive read channels. Power consumption and area are reduced because of the relaxed design requirements for the same linearity. The technique has been verified in Matlab simulations for a 6-bit 1Gsamples/s flash ADC under case of process gradients with non-zero mean offsets as high as 60mV and potentially serious spot offset errors as high as 1V for a 2V peak to peak input signal. The proposed technique exhibits an improvement of over 15dB compared to pure averaging flash converters for all cases. The circuit-level simulation results, for a 1V peak to peak input signal, demon- strate superior performance. The reported ADC was fabricated in TSMC 0.18 ??mCMOS process. It occupies 8.79mm2 and consumes about 400mW from 1.8V power supply at 1GHz. The targeted SFDR performance for the fabricated chip is at least 45dB for a 256MHz input sine wave, sampled at 1GHz, about 10dB improvement on the 6-bit flash ADCs in the literature.

£¸¡B Pyrolysis of 2-methoxy-2¡¦-methylthiostilbene (22a) and 2,2¡¦-di(methylthio)stilbene (22b) gave not only polycyclic aromatic hydrocarbons (PAH) 17¡B18¡B2, but also the products 33, 34. In addition, photolysis of 22a¡B22b¡B2,2¡¦-dimethoxy stilbene (13) gave photocyclic products 31¡B40¡B12¡B45¡B46. ¤G¡B Pyrolysis of 2-dimethylamino-N-(arenylidene)anilines (20a-f) gave not only 1-methyl-2-arylbenzimidazole (25a-f), but also gave 2-arylquinoxaline (26a-e). Furthermore, compound 20f gave 37 and 25f, but didn't give 26f. ¤T¡B Pyrolysis of benzoic 1,2-dimethyl-3-indolyl anhydride gave 1,2-dimethylindole (19) ¡B3-methylquinoline (30) ¡B4-methylquinoline (31).

Les mémoires non volatiles de type Flash sont aujourd'hui présentes dans un grand nombre de circuits intégrés conçus pour des applications électroniques portables et occupent une grande partie de leur surface. L'absence de défauts à l'intérieur de ces mémoires constitue donc un des éléments clés du rendement de production pour tous les fabricants de ce type d'applications. Cependant, la grande densité d'intégration et la complexité de leur procédé de fabrication rendent ces mémoires Flash de plus en plus sensibles aux défauts de fabrication. Pour mettre en évidence les défaillances qui altèrent la fonctionnalité de ces mémoires, des solutions de test efficaces et peu coûteuses doivent être mises en place Les solutions et algorithmes actuellement utilisés pour tester les mémoires RAM ne sont pas adaptés à l'environnement Flash à cause de la faible vitesse de programmation de celle-ci. De plus, les modèles de faute que l'on trouve dans la littérature et qui sont relatifs aux mémoires RAM ne sont pas forcément réalistes dans le cas des mémoires Flash. La première partie de cette thèse propose une analyse complète des défauts réalistes que l'on trouve dans ces mémoires et qui sont extraits de données silicium issue d'une technologie Flash 150nm. Cette analyse, basée sur l'injection de défauts dans une matrice réduite de mémoire Flash, a permis de mettre en exergue un grand nombre de comportements fautifs et de leur attribuer des modèles de faute fonctionnels. La suite de ce travail de thèse est consacrée à l'élaboration de nouvelles solutions de test permettant d'améliorer les stratégies existantes. Les solutions proposées sont construites en s'appuyant sur les spécificités de la mémoire Flash, comme par exemple sa faculté à programmer certains de ses blocs en une seule fois avec le même motif et en un temps de programmation réduit. Une évaluation de ces solutions est ensuite effectuée à l'aide d'un simulateur de faute que nous avons spécialement développé à cet effet. Cette évaluation montre l'efficacité des solutions de test proposées en termes de couverture de fautes et de temps de test. La validation sur une mémoire Flash de 4Mbits a montré un gain en temps de test considérable (d'un facteur 34) ainsi qu'une couverture de fautes accrues (notamment pour les fautes de couplage) par rapport à des solutions utilisées dans l'industrie.

<p>I traditionella butiker kan kunden välja att ta kontakt med en försäljare för att få information om produkter eller tjänster. Försäljaren kan tipsa om lösningar efter kundens behov, även visa upp hur produkten fungerar och kunden kan själv välja vilken fråga han eller hon vill ha svar på. Den här mänskliga realtidskontakten kan i många fall vara värdefull och förtroendegivande för kunden. Vi antar att mervärden skapas för kunden när denne kan mötas ansikte mot ansikte och samtala med försäljare i en webbutik. För att se vilka dessa mervärden kunde vara, designade vi en prototyp för videosamtal. Denna implementerades i en fiktiv webbutik, som tillhandhöll kläder. Fem testpersoner fick agera presumtiva kunder och föra videosamtal med en professionell försäljare. Testpersonerna och försäljaren satt i olika rum och videosamtalen fördes via ett lokalt nätverk. Efter varje test genomfördes en kvalitativ intervju med testpersonerna och resultaten visade vilka mervärden som hade skapats. Ett mervärde var den personliga servicen med omedelbar feedback som försäljaren gav, i huvudsak via ljudkanalen. Videosamtalen medförde att kunderna kunde förhandla om priser och leveranstider. Ett annat var att kunder kunde få sina klädmått bedömda, men endast korrekt bedömda i två fall av fem. Ett annat visuellt mervärde var att kunden kunde be försäljaren att visa upp olika kombinationer av klädesplagg för att se hur de passade ihop med varandra. En testperson tyckte ett mervärde var att klädesplaggen kunde ses ur den vinkel som önskades. Ytterligare ett mervärde var att webbutiken upplevdes som trovärdig när försäljaren fanns i den som en fysisk gestalt. Testpersonerna tyckte att videosamtalen gjorde att de fick förtroende för webbutiken.</p> / <p>In retail shops in real life the customer can chose to contact a salesman to get information about products or services. The salesman can recommend solutions depending on the customers needs. The salesman can show the product to the customer and tell how it works. The customer on the other hand can ask questions to the salesman about the product to get the specific information that interests him or her. This human contact in real time can be valuable and confidece inspiring for the customer in many situations. We assume there are surplus values for the customer when he or she will meet face to face with a salesman via a video call in a webshop. To find out which these surplus values could be we designed a prototype for video calls. This was implemented in a fictitious webshop that supplied clothes. Five persons with experience from webbshopping acted customers and had video calls with a professional salesman. The customers and the salesman were in different rooms and could only communicate through a video call. Their computers were connected via a local network. We did qualitative interviews with every customer after each test and the results showed the surplus values that were generated. One surplus value was the personal service with instant feedback that the customer got from the salesman, mainly through the sound channel. The video calls resulted in negotiations about prices and delivery times. Another surplus value was that the salesman estimated the customers sizes in trousers and jackets. He only succeded in two cases of five. Another visual surplus value was that the customer asked the salesman to show articles of clothing in different combinations to see how them fit together. One person thought one surplus value was that he could see an article of clothing from whichever angle he wished. Further surplus value was that the customers experienced the webshop as trustworthy when the salesman was there as a physical human being. The customers thought that the video calls caused that they got confidence in the webshop.</p>

This thesis discusses two patterning techniques: Step and Flash Imprint Lithography, a nanoimprint technique, and patterning thin films utilizing electrohydrodynamic instabilities. Step and Flash Imprint Lithography, SFIL, is promising alternative approach to photolithography. SFIL replicates the relief pattern of a template in a photocurable liquid that has been dispensed on a substrate. The pattern is then crosslinked when the photocurable liquid is exposed to UV light through the template. In order to study the volume change in the created features upon exposure, a stochastic mesoscale model was formulated. This model allows the study of the possibility of defects forming, from under cured etch barrier, or particle contamination of the template. The results showed large defects should not occur regularly until the minimum feature size is below 3 nanometers. The mesoscale model proved to computationally intensive to simulate features of engineering interest. A base multiscale model was formulated to simulate the effects of the densification of the photocurable liquid as well as the effects of the polymerization on the feature integrity. The multiscale model combines a continuum model (compressible Mooney-Rivlin) coupled to the mesoscale code using the Arlequin method. The multiscale model lays the framework that may be adapted to the study of other SFIL processes like template release. Patterning thin films utilizing electrohydrodynamic instabilities allows for the creation of periodic arrays of pillar like features. These pillars form due to the electric field destabilizing the thin film. Prior work has focused on utilizing polymeric films heated above their glass transition temperatures. In order to decrease the process time in the pillar formation process, work was done to study photocurable systems. The systems which proved favorable to the pillar creation process were the thiol-ene system as well as the maleimide systems. Further work was done on controlling the packing and ordering of the formed pillar arrays by using patterned templates. The result of these studies is that control was only able to be achieved to the third generation of pillars formed due to the inability to fully control the gap over the entire active area. / text

Compositional simulation is a complex task that involves solving several equations simultaneously for all grid blocks representing a petroleum reservoir. Usually, these equations are separated into two groups: primary and secondary equations. Similarly, the unknowns of the system are also separated into primary and secondary variables. Considering the large number of unknowns, there are many ways to separate such variables in order to deal with the primary variables. This work aims at comparing a number of formulations for compositional reservoir simulation. It also aims at enhancing the formulations with new features not provided in the original publications. To accomplish these objectives, various formulations prevailing in the literature are implemented in The University of Texas at Austin in-house fully implicit simulator named GPAS (General Purpose Adaptive Simulator) and their performances were compared. Subsequently, some of the formulations were enhanced and tested for various applications. The comparison of the formulations studied indicated differences in efficiency for each approach. These differences come from the fact that when one is solving for a different set of primary variables, the manipulation of the equations is analogous to the use of a preconditioner applied to a linear system of equations. Furthermore, unlike a preconditioner, changing the primary variables affects the non-linear solver. Therefore, differences in terms of the number of Newton-Raphson iterations, used for solution of nonlinear equations resulting from discretization of nonlinear partial differential equations representing fluid flow in the reservoir, are expected. In addition to these differences in the non-linear solver, many formulations explore the fact that a reduced number of equations need to be solved implicitly, thus considerably reducing the CPU time dedicated to the linear solver. Finally, new features not provided in the original published formulations such as three-phase flash calculation, physical dispersion, and unstructured grid were implemented and verified. Additionally, it was demonstrated that, in certain situations, these enhancements are essential to properly model the physical phenomena occurring in oil and gas reservoirs. / text

Steady state reflectance and emission characteristics of anthracene adsorbed on silica gel and titania-silica mixed oxides have been investigated as a function of sample loading. Titania-silica mixed oxides with 1, 3, 5 and 10 wt. % TiO2 were prepared by two different methods: a dropwise method and a sol-gel route. Ground state diffuse reflectance and fluorescence emission spectra of anthracene adsorbed on titania-silica surfaces show a dependence on titania content. The absorption peaks of anthracene are difficult to resolve at higher titania content due to the increasing red-shift of the titania absorption edge. The absorption edge of titania is shifted to longer wavelengths and the band gap energy decreases with increasing the titania loading. Diffuse reflectance laser flash photolysis at 355 nm produces both the triplet and radical cation of anthracene and gives relevant information regarding the photochemical transients and the kinetics details of the surface photochemical processes. Energy dependence studies confirm the monophotonic nature of the triplet production, whereas the anthracene radical cation is formed by monophoton or multiphoton ionisation in the mixed titania-silica systems. Energy and electron transfer reactions of anthracene co-adsorbed with azulene as electron donor on silica sol-gel and titania-silica mixed oxides prepared by the sol-gel method with different titania content have been studied using the time-resolved diffuse reflectance laser flash photolysis technique. The fluorescence of excited anthracene adsorbed on silica sol-gel is quenched by the addition of azulene, while co-adsorption of azulene on titania-silica mixed oxides resulted in a decrease in the fluorescence intensity of the adsorbed anthracene due to the formation, at the same time, of anthracene radical cation and Ti3+ species on the titania-silica surface. Triplet-triplet energy transfer from the excited anthracene to ground state azulene and electron transfer from azulene to the anthracene radical cation have been investigated using a time-resolved diffuse reflectance laser flash photolysis technique following laser excitation at 355 nm. Bimolecular rate constants for energy and electron transfer between anthracene and azulene have been obtained. Kinetic analysis of the decay of the anthracene triplet state and radical cation show that the kinetic parameters depend on the titania content of the sample and the azulene concentration. This indicates that the rate of energy and electron transfer reactions increases as a function of azulene concentration and decreases with increasing titania content in titania-silica mixed oxides, whereas the observed rate of reaction on silica sol-gel is predominantly governed by the rate of diffusion of azulene. Electron transfer reactions in a ternary system using azulene for hole transfer between 9-anthracenecarboxylic acid radical cation as electron acceptor and perylene as electron donor were also studied in order to demonstrate the mobility of radical cations on the silica sol-gel and titania-silica surfaces. The co-adsorption of azulene as a molecule shuttle with 9-anthracenecarboxylic acid and perylene on both silica sol-gel and titania-silica systems has been shown to enhance the rate of electron transfer in this ternary system. Activation energies for energy and electron transfer on photoinduced bimolecular and termolecular processes on silica sol-gel and titania-silica mixed oxides have been measured. In bimolecular anthracene / azulene systems, at higher azulene loadings, the activation energies and the pre-exponential factors on titania-silica surfaces are the same for both energy and electron transfer and are comparable with the parameters extracted for azulene diffusion on silica Davisil suggesting that azulene diffuses across the silica Davisil and titania-silica mixed oxides surfaces, while at lower azulene loadings, ion-electron recombination dominates and the activation energy extracted is for this process. In a ternary 9-anthracenecarboxylic acid / azulene / perylene system, the activation energy for perylene diffusion is higher than that observed for the anthracene / azulene system, reflecting the lower mobility of the perylene molecule. In this study, a series of titania-silica samples with different loadings of titania (1 10 wt. %) prepared by the sol-gel method and also the pure TiO2 P25 Degussa have been used to study the photocatalytic degradation of 4-chlorophenol in aqueous solution under UV light irradiation. The absorption peak of 4-chlorophenol at 280 nm decreases with increasing titania content and finally disappeared suggesting that titania has a positive influence on the degradation of 4-chlorophenol. The investigated titania-silica mixed oxides prepared by the sol-gel method are less efficient photocatalysts for the degradation of 4-chlorophenol than TiO2 P25.