Dissertations / Theses on the topic 'Lonic liquids'

La investigación y desarrollo de líquidos iónicos a temperatura ambiente (RTILsl va cobrando mayor importancia, como una necesidad de contar con materiales y sustancias químicas apropiados para diversos procesos químico-industriales, así como al creciente uso de ciertas fuentes alternativas de energía, más llevaderos con nuestro medio ambiente. En este artículo se hace una reseña sobre los líquidos iónicos, sus propiedades físicas y de transporte, aplicaciones presentes y futuras.
Room temperature ionic liquids (RTILs): Properties, applieations and future prospeetsResearch and development of room-temperatureionic I iquids (RTILs) is becoming more important, as a need to count with materials and chemical substances suitable for several processes in chemical industries, as well as for the growing use of alternative sources of energy, much more friendly with our environment. In this paper is presented a review on ionic liquids, their physical and transport properties, current and future applications

An Ultraviolet to Visible (UV-Vis) spectroscopic analysis based on fuzzy logic approach has been developed for furan content measurement in transformer oil. Following the successful identification and quantification of furan derivatives in transformer oil by ASTM D5837 standard, the new approach is able to approximate the furan content more conveniently and economically. As furan concentration level would determine the absorption intensity in UV-Vis spectral range, the fuzzy logic software model developed would exploit this characteristic to aggregate the furans content level in transformer oil. The UV-Vis spectral response at other ambient temperature is also studied. The proposed technique provides a convenient alternative to conventional method of furan measurement by High Performance Liquid Chromatography (HPLC) or Gas Chromatography Mass Spectrometry (GC/MS) in ASTM D5837 Standard.

An Ultraviolet to Visible (UV-Vis) spectroscopic analysis based on fuzzy logic approach has been developed for furan content measurement in transformer oil. Following the successful identification and quantification of furan derivatives in transformer oil by ASTM D5837 standard, the new approach is able to approximate the furan content more conveniently and economically. As furan concentration level would determine the absorption intensity in UV-Vis spectral range, the fuzzy logic software model developed would exploit this characteristic to aggregate the furans content level in transformer oil. The UV-Vis spectral response at other ambient temperature is also studied. The proposed technique provides a convenient alternative to conventional method of furan measurement by High Performance Liquid Chromatography (HPLC) or Gas Chromatography Mass Spectrometry (GC/MS) in ASTM D5837 Standard.

Esta investigación tiene como objetivo principal, desarrollar un sistema de control para la gestión de la liquidez, orientado a crear valor e identificar las mejores técnicas operativas en un ambiente de incertidumbre, que aporte una ventaja competitiva a las empresas. En esta dirección, destacamos la aplicación de la lógica difusa, a partir de aplicación de diversos modelos, con fin de proporcionar una visión sobre: ¿cómo la lógica difusa puede ayudar en la toma decisión en la gestión de la liquidez? (la t eoría de los subconjuntos borrosos, números triangulares, entre otros). Así, se realizó una exhaustiva revisión de literatura sobre el estudio de la gestión de la liquidez en diferentes países y culturas empresariales. A partir de ello, se examinó los diversos componentes y variables. Además, se realizó un análisis desde la perspectiva de la teoría de agencia sobre la gestión de la liquidez. Como parte de las aportaciones de esta investigación, se presentan nuevos modelos aplicados a la gestión de la liquidez orientados a ayudar a las empresas en la toma de decisiones, mediante el uso de metodologías basadas en el tratamiento de la incertidumbre. A partir de estos, se muestra la eficacia y la utilidad de los modelos de lógica difusa aplicados para la gestión de la liquidez en las empresas. Esto ha permitido ofrecer diversas aportaciones a partir de publicaciones de artículos en revistas científicas y congresos internacionales. Por tanto, se considera que la investigación realizada, representa una herramienta útil al conocimiento científico y que permite avanzar en el estudio de gestión de la liquidez, a partir de la teoría de lógica difusa y su combinación con otras teorías financieras.
This research has as main objective to develop a control system for liquidity management, aimed at creating value and identify the best operational techniques in an environment of uncertainty that provides a competitive at enterprise advantage. In this direction, we highlight the application of fuzzy logic, from to applying various models, to provide insight on: how fuzzy logic can help in making decision on liquidity management? (the theory of fuzzy subsets, triangular numbers, etc.). Thus, a comprehensive review of literature on the study of liquidity management in different countries and business cultures was performed. From this, the various components and variables examined. In addition, an analysis was conducted from the perspective of agency theory on liquidity management. As part of the contributions of this research, they present new models applied to the management of liquidity aimed at helping businesses in decision-making, using based on uncertainty management methodologies. Based on these, shown the effectiveness and usefulness of fuzzy logic models applied for liquidity management in enterprises. This has allowed us to offer various contributions from publications of articles in scientific journals and international conferences. Therefore, it is considered that research represents a useful tool to scientific knowledge and that allows headway in the study of liquidity management, based on the theory of fuzzy logic and its combination with other financial theory.

Šio darbo tikslas – suprojektuoti ir išanalizuoti skysčio lygio valdymo sistemas su PI reguliatoriumi bei neraiškiosios logikos reguliatoriumi, atlikti imitacijas ir palyginti gautus rezultatus. Teorinėje dalyje apžvelgiamos skysčio lygio valdymo sistemos, jų pagrindiniai elementai. Taip pat išnagrinėjami sistemų valdymo ypatumai, naudojant neraiškiosios logikos ir PI reguliatorius. Tiriamojoje dalyje sudaryta: sistemos funkcinė schema, sistemos matematinis ir kompiuterinis modeliai. Atlikus procesų imitaciją nustatyta, kad sistemoje su PI reguliatoriumi pakeitus nuostatą dėl perreguliavimo gaunamos nepageidaujamos slėgio aukščio ir debito vertės. To išvengiama, naudojant neraiškiosios logikos reguliatorių. Darbo pabaigoje pateikiamos išvados. Darbą sudaro 7 dalys: įvadas, literatūros apie skysčio lygio valdymo sistemas analizė, tyrimo tikslas ir uždaviniai, teorinė dalis, tiriamoji dalis, išvados, literatūra. Darbo apimtis - 71 puslapiai be grafinės dalies, 53 iliustracijos, 6 lentelės, 40 bibliografinių šaltinių ir 4 internetinės prieigos.
The main goal of the thesis is to design and analyze liquid level control systems with a PI controller and a fuzzy logic controller, perform simulations and to compare the results. In the analytical part, liquid level control systems and main elements of liquid level control systems are overviewed. Also system control using PI and Fuzzy logic regulators is overviewed. In research part liquid level control system is projected practically. The research chapter consists of a functional scheme, mathematical and computer models design. The simulation of the system shows that changing the step size in the system with a PI controller results in unwanted total head and flow rate values because of an overshoot. This is avoided in the system with a fuzzy controller. At the end of the thesis there is a conclusions part. The work consists of seven parts: introduction, analysis of liquid level control system literature, main goal of the research, theory part, design part, conclusions, references. Work volume – 71 pages of text without appendixes, 53 illustrations, 6 tables, 40 bibliographical and 4 internet entries.

This thesis explores the application of two-dimensional (2D) materials such as graphene and single layer hexagonal boron nitride (h-BN) which are produced by liquid phase exfoliation for use in printed electronics and energy composite applications. In Chapter 2 I give a broad overview of the electrical, mechanical and optical properties of 2D materials among other nanomaterials that were used in the thesis such as carbon nanotubes and conductive polymers. Additionally I review the techniques and theory behind the exfoliation and dispersion of functional layered materials. In Chapter 3 I present the coating and printing techniques which were used in this thesis along with the experimental techniques and methods which I use to characterise my inks, films and devices. Chapter 4 is the first experimental chapter of the thesis and demonstrates the printing of 2D material heterostructures to create fully printed dieletrically gated field effect transistors with 2D materials on textile and polymer substrates. In this chapter I also demonstrate reprogrammable volatile memory, p and n type inverters, complementary inverters, and logic gates which pave the way to fully printed integrated circuits, operational at room temperature and pressure with 2D materials processed in liquid. In Chapter 5, I review spray coating (a highly industrial scalable printing technique), in terms of the optimisation of its parameters to achieve thin films of nanomaterials on three-dimensional (3D) surfaces. I then demonstrate that it is possible to create large area (∼750 cm2) transparent conducting films around curved surfaces with spray coating enabling a semi-transparent (around 360°) spherical touch sensor for interactive devices. Chapter 6 explores printed photonics for applications in terahertz (THz) frequencies. Here I demonstrate the feasibility of liquid phase exfoliated graphene to create THz saturable absorbers (SAs) which could enable many applications in THz frequencies such as tomography or time-resolved spectroscopy that require mode-locked (i.e. enabling a train of short pulses to be derived from continuous-wave operation) THz pulses. I also demonstrate that these SAs can be inkjet printed on demand providing unprecedented compactness in a quantum cascade laser system. Finally in Chapter 7, I look at the application of graphene in microbial fuel cells (MFC). I demonstrate that enhanced MFC output arises from the interplay of the improved surface area, enhanced conductivity, and catalytic surface groups of a graphene based electrode. As a final step graphene based anodes and cathodes which were entirely platinum free were combined to create an environmentally sustainable energy source.

碩士
國立臺灣大學
電機工程學研究所
95
In this thesis, a pendulum-type model is constructed to represent the liquid sloshing behavior in a rectangular container, caused by the motion of a one dimension ball-screw table. A fuzzy rule-based controller is adopted to damp the liquid sloshing and keep the cart near the center of the ball-screw table. In the controller, two fuzzy sub-controllers are designed to respectively control the liquid sloshing and the table displacement, and the sloshing control rules are based on pendulum model. The effectiveness of the adopted method is demonstrated through simulations and experimental results. In the experiment, it is seen that friction exists unavoidably in the ball-screw table. The nonlinear behaviors induced by friction would limit the performance of the system. In order to get a better performance, the LuGre model of friction is used for designing a compensation scheme.

碩士
義守大學
生物技術與化學工程研究所碩士班
97
Room-temperature ionic liquids (RTILs) are organic salts that melt below 373.15 K and have an appreciable liquid range.Room temperature ionic liquids have negligible vapor pressure, excellent thermal stability and special characteristics in comparison with conventional organic and inorganic solvents. Chemical fixation of carbon dioxide, by coupling with propylene oxide (PO) form propylene carbonate, was studied under the catalysis of ionic liquid: [Bmim]Br and ZnCl2. The reaction parameters were reaction time（1~5hr）, temperature（333~373K）, pressure（10~50atm）and catalyst/PO molar ratio. It was found that the conversion was increased with the increase of reaction time, pressure, temperature, and molar ratio. When the reaction time was 3hrs, and the catalyst molar ratio 10 at 373K and 30atm, the conversion of carbonate reached as high as 96%. According to these data conjectured reaction mechanism and calculated reaction rate and activation energy.

碩士
國立高雄第一科技大學
工程科技研究所
96
This thesis investigates the technique of PID and Fuzzy Logic control by means of control temperature system. In the acrylic reactor system, the temperature control is very important. But the heating and cooling process can be very complex, and are often poorly understood. What works and what does not works is generally know, but what things works is often known. The Fuzzy Controller is one of the most popular controllers in the industry. Now, temperature control of an exothermic tank reaction using Fuzzy Logic Controller is studied here. We propose a weighted function to tune the weights of the system error into the fuzzy controller. Then, output of the fuzzy logic is transmitted into controller to control plant. The controllers can stabilize a process with a minimal amount of prior knowledge and improve rise time, settling time and overshoot effectively. The temperature control process of acrylic reaction is a multivariable and nonlinear dynamic system. Facing this plant, this paper presents a theoretical analysis and study on optimal controller design for stability and accuracy of control temperature system. This paper is also present to design PID and Fuzzy Logic controller temperature strategy which is able to enhance the capacity of the system. Simulation research and physical analog experiment prove the feasibility of this control strategy.

碩士
元智大學
電機工程學系
95
In this thesis, optical logic gate is proposed by a novel structure and its application. Two liquid crystal spatial light modulators (LCSLMs) are used to construct the optical logic gate system. This optical logic gate with XOR operation is used to achieve both image encoding and decoding operations. This system is composed of two sets of LCSLMs, which is aligned by microscope and stuck with adhesive. It will take us less time to set up the system and to perform strict alignment in experiment. On the other hand, it can reduce the influence of vibration in optical experiment. We investigate the binary image encryption and decryption with Jones matrix in this system. In image encryption, we obtained the random binary image after encoding process. Furthermore, the decoded image is obtained by coupling of the encrypted image and random key. Finally, we utilize MSE and PSNR to evaluate the decrypted image under different random key. The simulation and experimental results are presented to investigate the performance of our system.