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1
Bily-Luton, Erin. "Post-Reinforcement Pause in Gamblers at Multi-Line Slot Machines." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2547.
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Post-reinforcement pause was examined to determine the reinforcing value of a win, loss, and a loss disguised as a win (LDW) for gamblers at multi-line video slot machines. The study was conducted in naturalistic settings across a variety of participants, age 21 years and older. The length of the post-reinforcement pause was recorded using a stopwatch for one win, one loss, and one LDW for each participant and was measured by recording the time between the outcome delivery and the initiation of the next spin. The different times were evaluated to determine which of the three resulted in the longest post-reinforcement pause for the gamblers following the slot machine outcome. The present study replicates and extends previous research on post-reinforcement pause in slot machine gambling, and provides discussion around the clinical utility of such findings on the prevention of problem gambling. Problem gambling is an epidemic, and there are numerous variables that contribute to its development. Post-reinforcement pause is one for those factors, and the present study can help us gain a better understanding of the events that maintain problem gambling and ways to prevent it. The results of the present study found that wins are the most reinforcing to gamblers compared to LDWs and losses, and that LDWs are significantly more reinforcing to gamblers than losses, as indicated by the patterns of the post-reinforcement pause.
2
Guldemir, Hanifi. "Prediction of induction motor line current spectra from design data." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287180.
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Sillars, D. B. "Non-reciprocal coupled-slot devices in fin-line structures for millimetric wavelengths." Thesis, University of the West of Scotland, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332980.
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Yang, Shun-Hui. "Giant birefringence silicon nanophotonic multi-slot waveguides for optical delay line applications." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3329926.
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Thesis (Ph. D.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed November 14, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 96-103).
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Cihangir, Aykut. "Radiation Characteristic Analysis Of Tapered Slot Antennas." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612367/index.pdf.
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The aim of this study is to investigate the effects of changes in the physical parameters of tapered slot antennas (TSA) on their radiation characteristics and also to explore the possibility of reconfiguration in the radiation pattern of TSA by
switching between two different types of tapering.
There are mainly three physical parameters that affect the radiation pattern of TSAs. These are antenna length, aperture width and the ground extension. After designing a wideband microstrip line to slot line transition, the effect of antenna parameter variations on the beamwidth and sidelobe level of the antenna are investigated through the use of a commercially available electromagnetic simulation software
HFSS by ANSOFT. The radiation characteristics of constant width slot antennas (CWSA) and linearly tapered slot antennas (LTSA) are compared. It is observed that
CWSAs exhibit narrower beamwidth and higher sidelobe level whereas linearly tapered slot antennas (LTSA) have wider beamwidth with lower sidelobe level compared to each other. A novel switching architecture between CWSA and LTSA is
proposed to obtain a reconfigurable antenna.
6
Meng, Xiangjun. "A synthesis technique for radial line slot array antennas with isoflux radiation patterns." Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28325.
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In this thesis the possibility of using radial line slot array (RLSA) antennas to provide low profile isoflux radiation patterns suitable for use as circularly-polarized tracking, telemetry & command (TT&C) antennas on low Earth orbit (LEO) satellites is investigated. The RLSA antenna elements are slot pairs located on concentric circles on the top plate of a radial waveguide. Conventional synthesis techniques cannot be used due to the fact that the RLSA antenna is a non-uniformly spaced array, the elements do not all have the same orientation, and the excitation amplitudes and phases are linked to the actual physical location of a particular slot pair. A technique is therefore developed for synthesizing such an RLSA antenna.
Keywords: Antennas, Radial Line Slot Antennas, Isoflux Radiation Patterns
7
Fox, Andrew John. "Invasive varactor tuning of a dielectric resonator." Thesis, Leeds Beckett University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297492.
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Taylor, Kevin. "EXAMINING MINIMUM BETS’ INFLUENCE ON THE ACTUAL BET WAGERED ON FIXED LINE SLOT MACHINES: A DESCRIPTIVE ANALYSIS." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/theses/1851.
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A descriptive analysis was conducted to examine the influence minimum bets 30 credits and 50 credits had on the actual bets wagered on slot machines that operated on fixed-lines. Results suggested that slots with the lower minimum bets correlated with higher wagers. There was a total of 107 participants actively gambling at two casinos located just outside of Chicago, Illinois. The participant pool was divided between 37 males and 70 females. On average, the participants who played the slot machines with a minimum bet of 30 credits actually bet more than the participants who played the slot machines with a minimum bet of 50 credits. More notably, results from a Chi-square test for significance suggested that there is a significant influence between the minimum bet required to play and the presence, or absence, of “minimizers” and “maximizers” (p <.05). Additional data analyses where also conducted that examined gender’s role and wagering tendencies, including an independent t-test. The main purpose of this paper was to examine minimizing and maximizing gambling behavior across low-value and higher-value machines.
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VASCHETTO, SILVIO. "Design and development of permanent magnet synchronous machines shaft-line embedded in aeronautic engines." Doctoral thesis, Politecnico di Torino, 2011. http://hdl.handle.net/11583/2615701.
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Technological advances in the aerospace industry have improved aircraft efficiency and reduced the cost of air transport, leading since 1960 to a continuous growth of the worldwide air traffic. Today it is postulated that also into the foreseeable future both the passenger and cargo air traffic will continue to growth, increasing the CO2 air transport emissions. In this contest, there are many environmental as well as commercial pressures on aircraft manufacturers to improve performances of future aircraft in terms of safety, air pollution, noise and climate change.
To achieve these goals, it is necessary revisiting the whole aircraft architecture system, with the introduction of new technologies for performing key functions on aircraft.
Today the conventional civil aircraft are characterized by four different secondary power distribution systems: mechanical, hydraulic, pneumatic and electrical. This implies a complex power distribution nets aboard, and the necessity of an appropriate redundancy of each of them. In order to reduce this complexity, with the aim to improve efficiency and reliability, the aerospace designer community trend is towards the `More Electric Aircraft (MEA)' concept, that is the wider adoption of electrical systems in preference to the others.
This solution involves an increase of the aircraft electrical loads and, as a consequence, heavy implications for the on-board electrical generation systems are predictable. The resulting increase of the electrical power requirements encourage the research of alternative solutions rather than simply scaling up existing technologies such as generators driven by gearboxes. To address these challenges, many studies are in the direction of the so called `More Electric Engine (MEE)', in which the electrical machines are integrated inside the main gas turbine engine to generate electrical power, start the engine and guarantee safety generation in case of a critical on-flight failure. In this way the mechanical gearbox which connects the actual generators to the aeroengine shaft can be eliminated.
The MEA and the MEE concept can be considered as an evolutionary implementation of the `All Electric Aircraft (AEA)', in which all the aircraft on-board systems are supplied in an electrical form. The MEE concept will involve important mechanical and thermodynamic implications in the aeroengine design, making necessary a preliminary system analysis on today conventional aeroengine, in order to evaluate the integration feasibility with the actual mechanical and environmental constraints. The electrical machines can be integrated inside the engine in some different positions, either in the front part before the combustion chamber, in particular in the low-pressure or in the high-pressure compressor stages, or in the rear part of the engine, in the tail-cone zone.
In the frame of the GREAT2020 (GReen Engine for Air Transport in 2020) project co-founded by Regione Piemonte, aimed to the development of new eco-compatible aircraft engines for the entry into service in 2020, the MEE concept focus is on the evaluation of the most suitable solution between four possible integration positions in the front part of the today conventional two-shaft GEnx turbofan engine. The rotational speeds and the maximum available volumes are respectively imposed by the shaft connection and by the available spaces inside the aeroengine.
In the purpose of the MEE concept on which the work presented in this dissertations is based, in order to evaluate the less critical solution between the proposed, a trade-off study conducted on preliminary electromagnetic design has been performed considering both radial and axial flux surface mounted permanent magnet synchronous machines. The comparison of the different solutions have been done on the base of same sizing indexes.
Due to the particular application in which the electrical machine integration is involved, in order to evaluate impact on the whole system performance, a wider trade-off study concerning the overall aeroengine system has been done by the aerospace company Avio, partner of the GREAT2020 project.
The focus of the work presented in this dissertation, is the development of appropriate tools to perform a preliminary electromagnetic design of radial and axial flux, surface mounted, permanent magnet synchronous machines with three-phase distributed and single-layer fractional-slot non-overlapping concentrated windings. In particular, this latter winding topology has been considered for its specific application for its shorter end-winding connections respect to the distributed layout, and for their high fault tolerant capability due to the electrical and physical separation between the phases which reduces the possibility of a fault propagation.
Regarding the radial flux topologies, both inner and outer rotor machine structures have been considered; for the axial flux machines the single-stage (one stator and one rotor) as well as the multi-stage structures, obtained connecting on the same axis more than one single-stage structure, have been considered.
The developed general purpose tools are based on simple geometrical approach using conventional design equations. The geometrical dimensions are computed starting from the design specifications and material utilization indexes imposed by the designer. The implemented codes would be a useful tool for the electrical machine designer in order to quickly define a preliminary electromagnetic design starting from a fresh sheet of paper. The conducted comparisons with commercial software have proved the validity of the tools for the conducted MEE trade-off study; however, in a prototype design aimed to the construction, detailed analysis using commercial software available on the market and Finite Element Method analysis have to be done in order to verify and improve in details the preliminary electromagnetic design obtained by the implemented codes.
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Hermány, Roman. "Vícevrstvá textilní anténní řada." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377157.
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Thesis focuses on the design and development of three possible methods to power the serial patch array and optimization of the chosen design. The antenna array is conceived as a multi-layered structure formed on a 3D textile substrate. The objective of this work is to identify the best possible configuration of antenna array for the use in automotive and aerospace industry. The first concept – array coupled by near microstrip line – proved in the case of the more serial elements as non-functional. The second concept – aperture coupled array – is unsuitable for use in close proximity to the electrically conductive shell of the aircraft. The third concept – array coupled with textile integrated waveguide – seems like the best possible solution. The design of the array coupled with textile integrated waveguide was optimized in consideration of the production process. The impedance bandwidth of this proposed three elements antenna is 890 MHz, the gain in the main lobe direction is 11.8 dBi.
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GAMBA, MATTEO. "Design of non conventional Synchronous Reluctance machine." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2669965.
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Synchronous reluctance (SyR) and Permanent magnet Synchronous Reluctance (PM-SyR) machines represent an answer to the growing emphasis on higher efficiency, higher torque density and overload capability of ac machines for variable-speed applications. Their high performance is particularly attractive in electric traction and industry applications. The SyR technology represents a convenient solution to obtain high efficiency machines at reduced cost and high reliability. The manufacturing costs are comparable to other existing technologies such as induction motors. Different SyR and PM-SyR machines with different ratings and applications were designed, for comparison with induction motors having equal frame. An accurate comparison between Induction motors, SyR and PM-SyR machines is reported, with reference to the IE4 and IE5 efficiency specifications that could become mandatory in the next years.
Three studies are classified under the term ”Non-Conventional” machines:
Line-Start SyR motor: is a special SyR machine designed for constant speed applications, line supplied. The rotor flux barriers are filled with aluminum, to obtain a squirrel cage that resembles the one of an induction motor. The manufacturing costs are comparable to those of the induction motor, and the efficiency is higher. Two prototypes were realized and tested.
FSW-SyR: tooth-wound coils and fractional slot per pole combinations were investigated. They are of interest because they permit a simplification and higher degree of automatization of the manufacturing process. However, FSW-SyR machines are known for their high torque ripple, low specific torque and power factor. The number of slots per pole was optimized to maximize the torque density. Dealing with the torque ripple, a lumped parameters model was used together with optimization in SyRE. A design with minimized ripple was obtained, comparable to a distributed winding machine in this respect. This design was prototyped and tested.
Mild Overlapped SyR: this study shows a new winding configuration applied to SyR and PM-SyR machines. The proposed case is in the direction to find a hybrid solution between distributed winding and tooth winding motors, that permits to reduce costs and improve performances. One limitation of this solution is that only number of pole pairs equal to five or higher are feasible, and this reduces the applicability of the solution to classical industry applications, where one to three pole pairs are normally used.
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Špůrek, Jan. "Textilní štěrbinová anténa." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242116.
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This diploma thesis is focused on design of various antenna structures, based on slot antennas, created in the wider wall of a rectangular-shaped waveguide. As the substrate, it is used a 3D textile material, while its properties are examined. They were designed structures, that operate with linear and circular polarization, and other related structures, that are used for feeding and power division. Structures are designed to operate at central frequency of 8 GHz and its vicinity.
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Andrade, Humberto Dion?sio de. "Desenvolvimento de um ressoador retangular de fenda com m?ltiplas camadas de substrato e com utiliza??o de material PBG para sistema de comunica??o sem fio." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15223.
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In the globalized world modern telecommunications have assumed key role within the company, causing a large increase in demand for the wireless technology of communication, which has been happening in recent years have greatly increased the number of applications using this technology. Due to this demand, new materials are developed to enable new control mechanisms and propagation of electromagnetic waves. The research to develop new technologies for wireless communication presents a multidisciplinary study that covers from the new geometries for passive antennas, active up to the development of materials for devices that improve the performance at the frequency range of operation. Recently, planar antennas have attracted interest due to their characteristics and advantages when compared with other types of antennas. In the area of mobile communications the need for antennas of this type has become increasingly used, due to intensive development, which needs to operate in multifrequency antennas and broadband. The microstrip antennas have narrow bandwidth due to the dielectric losses generated by irradiation. Another limitation is the degradation of the radiation pattern due to the generation of surface waves in the substrate. Some techniques have been developed to minimize this limitation of bandwidth, such as the study of type materials PBG - Photonic Band Gap, to form the dielectric material. This work has as main objective the development project of a slot resonator with multiple layers and use the type PBG substrate, which carried out the optimization from the numerical analysis and then designed the device initially proposed for the band electromagnetic spectrum between 3-9 GHz, which basically includes the band S to X. Was used as the dielectric material RT/Duroid 5870 and RT/Duroid 6010.LM where both are laminated ceramic-filled PTFE dielectric constants 2.33 and 10.2, respectively. Through an experimental investigation was conducted an analysis of the simulated versus measured by observing the behavior of the radiation characteristics from the height variation of the dielectric multilayer substrates. We also used the LTT method resonators structures rectangular slot with multiple layers of material photonic PBG in order to obtain the resonance frequency and the entire theory involving the electromagnetic parameters of the structure under consideration. xviii The analysis developed in this work was performed using the method LTT - Transverse Transmission Line, in the field of Fourier transform that uses a component propagating in the y direction (transverse to the real direction of propagation z), thus treating the general equations of the fields electric and magnetic and function. The PBG theory is applied to obtain the relative permittivity of the polarizations for the sep photonic composite substrates material. The results are obtained with the commercial software Ansoft HFSS, used for accurate analysis of the electromagnetic behavior of the planar device under study through the Finite Element Method (FEM). Numerical computational results are presented in graphical form in two and three dimensions, playing in the parameters of return loss, frequency of radiation and radiation diagram, radiation efficiency and surface current for the device under study, and have as substrates, photonic materials and had been simulated in an appropriate computational tool. With respect to the planar device design study are presented in the simulated and measured results that show good agreement with measurements made. These results are mainly in the identification of resonance modes and determining the characteristics of the designed device, such as resonant frequency, return loss and radiation pattern
No mundo globalizado moderno, as telecomunica??es assumiram um papel fundamental dentro das sociedades, provocando um grande aumento da demanda por tecnologia de comunica??o sem fio, isto vem acontecendo nos ?ltimos anos e tem aumentado bastante o n?mero de aplica??es que utilizam esta tecnologia. Em decorr?ncia dessa demanda, novos materiais s?o desenvolvidos no sentido de possibilitar novos mecanismos de controle e propaga??o de ondas eletromagn?ticas. A pesquisa para o desenvolvimento de novas tecnologias para comunica??o sem fios apresenta um car?ter multidisciplinar que abrange desde o estudo de novas geometrias para antenas passivas e ativas at? o de desenvolvimento de materiais para dispositivos que melhorem o desempenho naquela faixa de frequ?ncia de opera??o. Recentemente as antenas planares tem despertado interesses devido as suas caracter?sticas e vantagens que oferecem quando comparadas com os demais tipos de antenas. Na ?rea de comunica??es m?veis a necessidade de antenas desse tipo tem se tornado cada vez maior, devido ao seu intenso desenvolvimento, que necessita de antenas que operem em multifrequ?ncia e em banda larga. As antenas de microfita apresentam largura de banda estreita devido ?s perdas no diel?trico geradas pela irradia??o. Outra limita??o ? a degrada??o do diagrama de irradia??o devido ? gera??o de ondas de superf?cie no substrato. Algumas t?cnicas est?o sendo desenvolvidas para minimizar esta limita??o de banda, como ? o caso do estudo de materiais do tipo PBG Photonic Band Gap, para compor o material diel?trico. Este trabalho tem como objetivo principal o desenvolvimento do projeto de um ressoador de fenda com m?ltiplas camadas e com a utiliza??o de substrato do tipo PBG, onde foi realizada a otimiza??o a partir da analise num?rica e em seguida, projetado o dispositivo proposto inicialmente para a faixa do espectro eletromagn?tico compreendida entre 3-9 GHz, que inclui basicamente a banda S at? X. Foi utilizado como material diel?trico o RT/Duroid 5870 e RT/Duroid 6010.2LM onde ambos s?o laminados cer?micos PTFE com constantes diel?tricas de 2.33 e 10.2, respectivamente. Atrav?s de uma investiga??o experimental foi realizada uma an?lise dos resultados simulados versus medidos observando o comportamento das xvi caracter?sticas de radia??o a partir da varia??o da altura das multicamadas de subtrato diel?trico. Foi utilizado tamb?m o m?todo LTT ?s estruturas ressoadoras retangulares de fenda com m?ltiplas camadas, para a obten??o da freq??ncia de resson?ncia bem como toda a teoria que envolva os par?metros eletromagn?ticos da estrutura em estudo. As an?lises desenvolvidas neste trabalho foram realizadas com utiliza??o do m?todo LTT Linha de Transmiss?o Transversa, no dom?nio da Transformada de Fourier que utiliza uma componente de propaga??o na dire??o y (transversa ? dire??o real de propaga??o z), tratando assim as equa??es gerais dos campos el?tricos e magn?ticos em fun??o de yE e yH . A teoria PBG ser? aplicada para a obten??o da permissividade relativa para as polariza??es s e p dos substratos compostos de material fot?nico. Os resultados s?o obtidos com o software comercial Ansoft HFSS, usado para a an?lise precisa do comportamento eletromagn?tico do dispositivo planar em estudo, por meio do M?todo dos Elementos Finitos (FEM). Resultados num?rico-computacionais s?o apresentados em forma de gr?fico em duas e tr?s dimens?es, para aos par?metros de perda de retorno, frequ?ncia de radia??o, e diagrama de radia??o, efici?ncia de radia??o e densidade superficial de corrente para o dispositivo em estudo, e que tem como substratos, materiais fot?nicos e que fora simulado em uma ferramenta computacional apropriada. . No que diz respeito ao projeto do dispositivo planar em estudo s?o apresentados os resultados medidos e os simulados que apresentam boa concord?ncia com as medi??es efetuadas. Estes resultados consistem principalmente na identifica??o dos modos de resson?ncia e na determina??o das caracter?sticas do dispositivo projetado, como freq??ncia de resson?ncia, perda de retorno e diagrama de radia??o
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Petrov, Alexander. "Slow light photonic crystal line-defect waveguides." Göttingen Cuvillier, 2007. http://d-nb.info/989861244/04.
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Mustafa, Incebacak. "Design Of Series-fed Printed Slot Antenna Arrays Excited By Microstrip Lines." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612447/index.pdf.
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Series-fed printed slot antenna arrays excited by microstrip lines are low profile, easy to manufacture, low cost structures that found use in applications that doesn&rsquot require high power levels with having advantage of easy integration with microwave front-end circuitry. In this thesis, design and analysis of microstrip line fed slot antenna arrays are investigated. First an equivalent circuit model that ignores mutual coupling effects between slots is studied. A 6-element array is designed by using this equivalent circuit model. From the measurement and electromagnetic simulation results of this array, it is concluded that mutual coupling effects should be considered in order to achieve a successful design that meets the design specifications related to the main beam direction and sidelobe levels of the antenna. Next, an improved equivalent circuit model proposed for stripline fed slot antenna arrays is studied. It is observed that, the mutual coupling effects are incorporated into the equivalent model through the utilization of active impedance concept. Finally, the design equations proposed in the improved equivalent circuit model are derived for the microstrip line fed slot antenna array structure. To demonstrate the validity and the accuracy of the derived design equations, results obtained by the proposed analysis method are compared with simulation and measurement results. It is concluded that the proposed method successfully predicts the radiation pattern of the array by including the mutual coupling effects.
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Bhana, Vishal Bhooshan. "A slow-wave CMOS delay line filter for mm-wave applications." Diss., University of Pretoria, 2005. http://hdl.handle.net/2263/66201.
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The standardisation of the 60 - 80 GHz band by the IEEE802.15.3 task group 3C offers prospects for high speed gigabit wireless applications. This mm-wave band can be used to achieve high data rate transmission in high definition television processing and mobile data applications. Electronic devices utilising the 5th generation cellular standard will begin to use such transceiver chipsets. Nanoscale complementary metal oxide semiconductor (CMOS) technologies have enabled complete mm-wave systems-on-chip (SOC) containing distributed passive, RF active, and CMOS logic circuits. This approach offers the advantage of lower cost, reduced size and lower power consumption. Front-end filters are, however, typically omitted from this system integration due to the low achievable Qfactors of the constituent resonators, which results in high insertion loss and reduced selectivity. There is, therefore, a need for on-chip RF pre-select filters with low insertion loss that are immune to this Q-driven degradation. This research is aimed at the realisation of a miniaturised high performance passive filter in a CMOS technology for mm-wave technologies. Research questions have been formulated where the research outcomes result in a mm-wave passive filter topology. Firstly, the delay line filter is identified as a possible solution for implementation at mm-wave frequencies. Research has been conducted into CMOS planar transmission lines and their associated effects to identify the best suited geometry. Secondly, it is found that the delay performance of a transmission line can be improved by means of introducing geometrical shielding structures. The performance of the CMOS delay lines is evaluated using the quality factor (Q-factor) and group delay as a measure of importance. The delay lines are implemented within a delay line filter topology. The filter is synthesised and simulated in a circuit solver, after which the delay line and complete filter are simulated in a 3D full-wave electromagnetic (EM) simulation tool. The artwork of the complete design is exported, from the integrated circuit (IC) design tool, into the full-wave EM simulator to evaluate and verify the performance of the filter. Three slow-wave coplanar waveguide (CPW) delay lines and a passive mm-wave filter are designed and prototyped using the 0.13 _m bipolar complementary metal oxide semiconductor (BiCMOS) process from GlobalFoundries US as part of the experimental process. The best performing delay line, based on simulation results, has been implemented in a passive filter. The experimental verification confirms the 3D full-wave EM simulation results and answers the proposed research questions. Three CMOS CPW transmission lines have been manufactured and tested. Shielded CPW structures with narrow and wide strip spacings were manufactured to understand the slowwave mechanism. A third fabricated CPW with no shielding structures was used for comparison purposes. Slow-wave geometries have previously been studied, but this research focuses on the Q-factor and delay performance of the slow-wave CPW. Simulation and measured results demonstrate that the narrow strip spacing CPW achieves the greatest group delay at 70 GHz. The narrow strip spacing, wide strip spacing and no strip spacing lines achieve Q-factors of 38.3, 33.64 and 24.9 at 70 GHz respectively, with the narrow strip spacing showing a 34.9 % improvement in Q-factor compared to the no strip spacing CPW. The filter demonstrates a centre frequency of 70.05 GHz, a -3dB bandwidth of 20.74 GHz, a passband attenuation of 5.83 dB and a Q-factor of 4.82. The slow-wave filter compares well with recent literature published on CMOS mm-wave filters.Dissertation (MEng)--University of Pretoria, 2017.
Electrical, Electronic and Computer Engineering
MEng
Unrestricted
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Zuboraj, MD R. "Coupled Transmission Line Based Slow Wave Structures for Traveling Wave Tubes Applications." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1477947681829031.
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Alfonso, Alós Esperanza. "New quasi-TEM waveguides using artificial surfaces and their application to antennas and circuits." Doctoral thesis, Universitat Politècnica de València, 2011. http://hdl.handle.net/10251/11073.
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Research interest: In recent years we have seen the emergence of
commercial applications at high frequencies, such as the top part of
the microwave band and the millimeter and sub-millimeter bands,
and it is expected a big increase in the coming years. This growing
demand requires a rapid development of low-cost technology
with good performance at these frequencies, where common technologies,
such as microstrip and standard waveguides, have some
shortcomings. In particular, existing solutions for high-gain planar
scanning antennas at these frequencies su er from the disadvantages
of these technologies giving rise to high-cost products not suitable
for high volume production.
Objectives: The main objective of this thesis is to study the feasibility
of a new proposal to improve existing solutions to date for
low-cost high-gain planar scanning antennas at high frequencies.
This overall objective has resulted in another central objective of
this thesis, which is the research of new quasi-TEM waveguides that
are more appropriate than current technologies for the realization
of circuits and components at these frequency bands. These guided
solutions make use of periodic or arti cial surfaces in order to con-
ne and channel the elds within these waveguides.
Methodology: The work follows a logical sequence of speci c tasks
aimed at achieving the main objective of this thesis. Chapter 2
presents the proposed guiding solution and shows its performance
numerical and experimentally. The optimized design of high-gain
antennas based on waveguide slot arrays requires the development
of e cient ad-hoc codes. The implementation and validation of this
code is presented in Chapter 3, where a new method for the analysis
of corrugated surfaces is proposed, and in Chapter 4, which extends
this code to the analysis of waveguide slot arrays. The process
design and optimization of a two-dimensional array is described
in Chapter 5, where a preliminary experimental validation is also
described. Moreover, the proposed guiding solution has inspired
the development of a new guiding technology of wider bandwidth
and more versatile for the realization of circuits and components at
high frequencies. Chapter 6 presents the contributions to the study
of this technology and its application to the design of circuits.Alfonso Alós, E. (2011). New quasi-TEM waveguides using artificial surfaces and their application to antennas and circuits [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/11073
Palancia
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Balducci, Anthony (Anthony G. ). "Studies of DNA dynamics in slit-like nanochannel confinement." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45916.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2008.Includes bibliographical references (p. [135]-143).
The ability to visually observe single DNA molecules has greatly improved our understanding of polymer physics, from gel electrophoresis to the theology of dilute (and even concentrated) polymer solutions. The use of DNA in these general studies, though, resulted in a depth of specific knowledge concerning a particular polymer of major interest in biology. Researchers have taken advantage of this wealth of knowledge to develop new, faster, cheaper, and more direct methods of extracting the information, at a coarse level, embedded in the sequence of basepairs along the DNA backbone. Further development, though, is now limited by the ability to control and manipulate the position and conformation of single DNA molecules. It was recognized long ago that confinement of polymer molecules in geometries with dimensions on the order of the polymer size would greatly affect the physical behavior of that polymer. These physical changes were later hypothesized to be of use to control single molecules of DNA. However, until recently, the confinement theories and their use stood untested due to a lack of techniques to reliably and controllably construct micro- (and nano-) devices with such small feature sizes. It is the focus of this thesis to investigate these confinement effects in an ideal, nanofabricated geometry and their use in the manipulation and control of single DNA molecules. In this thesis, we present a series of single-molecule visualization studies aimed at elucidating polymer behavior in confinement and methods of possible use in the manipulation and control of the polymer conformation. In particular, confinement in a slit was shown, both experimentally and through scaling analysis, to diminish long length scale polymer-induced solvent flow sufficiently enough to render those effects negligible in the behavior of the confined molecule. We also demonstrate that confinement also alters the diffusion and relaxation time of the DNA, and we compare their dependence on channel height and molecular weight to existing theories.
(cont.) De Gennes' blob theory is found to describe the molecular weight scalings quite well, but predictions of the scalings with channel height are plagued by an oversimplified description of short length scale polymer-solvent interaction used in the theory. Thus, empirical knowledge is needed to adequately predict the scaling of DNA transport coefficients in confinement. We also investigate aspects of polymer deformation in confinement. We observe, for the first time, two slow modes of polymer relaxation. The two modes are found to govern polymer behavior based on the polymer's extension, a phenomenon unique to confinement in polymer physics. A simple, physical model is developed to explain the origin of the two governing time scales, to explain their scaling with channel height and molecular weight, and to predict the extension at which the exchange between the two timescales occurs. We also examine the effects of these two characteristic time constants on the steady-state stretch of molecules in confinement. We find that the second-longest relaxation time determines the deformation rate needed to unravel the coil, unlike bulk polymer deformation. Interestingly, details of this unraveling change significantly in confinement, highlighting the need for further work in this area. In larger channels, we demonstrate that microfabrication techniques in the form of an obstacle array with dimensions smaller than the polymer size can aid polymer stretching. While a polymer will often fold or kink during stretching, we find the use of a collision event to "precondition" the polymer conformation for stretching makes these folds and kinks less likely, and therefore, stretching occur more rapidly. The efficiency of the device depends strongly on the probability of a collision event, and results from single molecule/single post experiments are used to demonstrate the capability of a second-generation device. The impact of this thesis will be two-fold. Our fundamental results have and will continue to serve as a basis of comparison and a springboard for more complicated studies of confined polymer physics.
(cont.) These studies provide detailed information on DNA transport coefficients in geometries widely utilized in microfabricated devices. We also directly display the effects of confinement on DNA manipulation. Non-equilibrium polymer dynamics are found to be highly nontrivial, exemplified by the importance of a new timescale of polymer motion. Importantly, it is this new timescale that is of concern for applications such as gene mapping where large scale polymer deformation is required. Lastly, we demonstrate the success of a unit-operation-like approach to the design of polymer manipulation devices.
by Anthony Balducci.
Ph.D.
20
Simon, M. N., I. Pascucci, S. Edwards, W. Feng, U. Gorti, D. Hollenbach, E. Rigliaco, and J. T. Keane. "TRACING SLOW WINDS FROM T TAURI STARS VIA LOW-VELOCITY FORBIDDEN LINE EMISSION." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/622166.
Full textAbstract:
Using Keck/HIRES spectra (Delta v similar to 7 km s(-1)) we analyze forbidden lines of [O I] 6300 angstrom, [O I] 5577 angstrom. and [S II] 6731 angstrom. from 33 T Tauri stars covering a range of disk evolutionary stages. After removing a high-velocity component (HVC) associated with microjets, we study the properties of the low-velocity component (LVC). The LVC can be attributed to slow disk winds that could be magnetically (magnetohydrodynamic) or thermally (photoevaporative) driven. Both of these winds play an important role in the evolution and dispersal of protoplanetary material. LVC emission is seen in all 30 stars with detected [O. I] but only in two out of eight with detected [S. II], so our analysis is largely based on the properties of the [O. I] LVC. The LVC itself is resolved into broad (BC) and narrow (NC) kinematic components. Both components are found over a wide range of accretion rates and their luminosity is correlated with the accretion luminosity, but the NC is proportionately stronger than the BC in transition disks. The full width at half maximum of both the BC and NC correlates with disk inclination, consistent with Keplerian broadening from radii of 0.05 to 0.5 au and 0.5 to 5 au, respectively. The velocity centroids of the BC suggest formation in an MHD disk wind, with the largest blueshifts found in sources with closer to face-on orientations. The velocity centroids of the NC, however, show no dependence on disk inclination. The origin of this component is less clear and the evidence for photoevaporation is not conclusive.
21
Goksu, Mesut. "Analysis Of Slot Coupled Patch Antennas Using Closed Form Green." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610996/index.pdf.
Full textAbstract:
In this thesis, an analysis technique for the slot coupled patch antennas using MoM in
conjunction with the closed form Green&rsquos functions is presented. Slot coupled patch antennas are fed by a microstrip open stub which is coupled to the patch through an electrically small slot. Current distributions over the microstrip line, slot line and the patch are represented by rooftop basis functions. First, a relatively simple structure, microstrip coupled slot line is investigated using the proposed technique. Then the method is extended to the slot coupled patch antenna geometry. By using the method, current distributions on the feedline and the patch are calculated for a generic slot coupled patch antenna. Then by using the distributions, return scattering parameters of the antenna is approximated with complex exponentials using Prony&rsquo
s method. A parametric study is carried out to observe the effect of each antenna component on the antenna performance. Current distributions and return loss calculations are repeated for modified antennas to observe and demonstrate the performance differences. All simulations are verified using HFSS®
software and the results available in the literature.
22
Gullotta, Andrea. "The "Paris of the Northern Concentration Camps": the Cultural Life and the Literature of the Solovki Prison Camp between 1923 and 1930." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3423329.
Full textAbstract:
This research intends to bring to the attention of the academic community a ‘cultural episode’ that was rare in all respects. While the Soviet Union entered into Stalinism and the intelligentsia was being eliminated, while the repressive system was becoming more and more perfected and the socio-cultural context that would define the artistic canons of Soviet literature and art was being formed, while the system of concentration camps was being created and the pre-revolutionary Russian culture was dying, a number of intelligenty created a small intellectual citadel in the place appointed for their elimination. A citadel whose artistic canons were those of the pre-revolutionary or ‘bourgeois’ Russia. The ‘Paris of the northern concentration camps’ is what one detainee, Professor Ivan Ozerov, called the Solovetsky Lager Osobogo Naznachenia (Solovki Special Purpose Prison Camp), the so-called SLON. At Solovki, site of the first Soviet Gulag, while other prisoners perished by the hundreds or suffered horribly, a small number of inmates had the opportunity to continue the intellectual activity in which they were involved before their imprisonment. In doing so, they opposed the system that wanted to crush them with a form of cultural resistance, a sort of peaceful protest, destined to be defeated from a material point of view, yet still able to leave its mark and to send a message of extraordinary value to all humanity.
After a large introductory section dedicated to the history of the Solovki prison camp, the main part of the dissertation is dedicated to the in-depth analysis of the cultural life of the camp and, above all, of the literary works produce within. The dynamics that took to the creation of the “cultural village” of the SLON, as well as the profiles of the main protagonists of it, are described. The consultation of many archival documents, as well as all the publications of the camp, helped to reconstruct the development of the “SLON culture”. The main goal of the research is to assess thoroughly a topic scarcely investigated in order to give literary dignity to the many authors who published in the journals of the camp. Their literary works often reached high levels of quality and still represent a unique case of lagernaya literatura.
Three appendices conclude the dissertation. The first is dedicated to the contents of the publications that have been analysed; the second contains the biographies and selected texts of the main authors; the final appendix is dedicated to the Italian prisoners of the Solovki camp.
The entire work is presented in English.Il presente lavoro intende proporre all’attenzione della comunità scientifica un “episodio culturale” raro. Mentre l'intelligencija veniva sterminata e l'Unione Sovietica imboccava la via dello stalinismo, mentre la macchina repressiva si affinava e si andava formando sempre più la temperie socio-culturale che avrebbe fissato i canoni artistici dell'arte e della letteratura sovietica, mentre veniva creato il sistema dei campi di concentramento e la cultura russa prerivoluzionaria moriva, alcuni intellettuali, sfruttando una serie di circostanze del tutto casuali, furono capaci di creare, nel luogo deputato alla loro eliminazione, una piccola cittadella intellettuale, dove i canoni artistici in vigore erano prevalentemente quelli prerivoluzionari o, volendo etichettarli, quelli “borghesi”. La “Parigi dei lager del nord”: così un detenuto, il professore Ivan Ozerov, ha definito il Soloveckij Lager’ Osobogo Naznačenija (Campo di prigionia a destinazione speciale delle Solovki), il cosiddetto SLON. Sulle isole Solovki, sede del primo gulag sovietico, mentre altri prigionieri perivano a centinaia o venivano sottoposti a intollerabili martirî, un ristretto numero di detenuti ebbe l'opportunità di continuare l'attività intellettuale iniziata prima dell’imprigionamento, opponendo al sistema che li voleva annientare una resistenza di natura culturale, una sorta di lotta pacifica, destinata a sicura sconfitta sul piano materiale e, tuttavia, capace di lasciare il segno e di trasmettere all'umanità intera un messaggio di straordinario valore. Dopo un'ampia introduzione storica incentrata sulla storia del gulag delle Solovki, il presente lavoro fornisce un'approfondita analisi della vita culturale del campo e soprattutto della letteratura prodotta in esso, sviluppando a fondo le dinamiche che permisero la creazione del “villaggio culturale” dello SLON, mettendone in luce le personalità principali e portando a conoscenza, sulla scorta dell'analisi di numerosi materiali d'archivio e dei giornali pubblicati dall'amministrazione del campo, i momenti che ne segnarono l'evoluzione. Obiettivo primario della ricerca è quello di investigare con il massimo rigore scientifico un argomento che è stato complessivamente poco indagato al fine di restituire dignità ai numerosi autori che pubblicarono le loro opere sulla stampa del campo, le cui produzioni letterarie spesso raggiunsero livelli elevati, oltre a rappresentare un “unicum” nel panorama della lagernaja literatura. Il lavoro è corredato di tre appendici che presentano, rispettivamente, lo spoglio delle riviste e degli organi di stampa presi in analisi, le biografie e i brani scelti dei principali autori trattati e la ricostruzione delle vicende dei prigionieri italiani reclusi all'interno del campo. Il lavoro è redatto in lingua inglese.
23
Zeestraten, J. "Strolling to the beat of another drum : living the 'Slow Life'." Diss., Lincoln University, 2008. http://hdl.handle.net/10182/833.
Full textAbstract:
As the pace of life in contemporary Western society accelerates, an increasing number of people are engaging in an alternative lifestyle: ‘Slow Living’. Although popular in the media, Slow Living, which addresses issues of quality of life, is a relatively new area of academic enquiry. Given a lack of empirical research, especially on the realities of the Slow Life in a New Zealand context, this ethnographic study aims to augment the knowledge on this lifestyle by focusing on how families experience Slow Living. The key research question is: How do families live their interpretations of a Slow Life? To answer this question, this study examined the everyday lives of five Slow Living families in Canterbury, New Zealand. Adult family members were given a time-use diary to complete over two days. These diaries were then used as a foundation for in-depth interviews and participant observation. Slow Living families hold to a number of personal values, such as personal agency, conscious living and leading meaningful lives. These comprise their ideal way of living. The families are also faced with a number of challenges and have to employ strategies to balance their ideal and what is possible. The different ways families adapt produces a variety of Slow Living lifestyles.
24
Bishop, Derron L. "Alterations in Z-line thickness following fast motoneuron transplantation onto slow twitch skeletal muscle fibers." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/935926.
Full textAbstract:
Differentiation of skeletal muscle fibers into fast and slow twitch appears to be under control of the stimulation pattern imparted by motoneurons innervating these muscle fibers. Fast twitch muscle fibers receive intense stimulation for brief periods of time while slow twitch muscle fibers receive less intense stimulation for much longer periods of time. This study examined thickness of Zlines in dually innervated skeletal muscle fibers of slow twitch soleus muscle following transplantation of the fast extensor digitorum longus (EDL) nerve onto the surface of the soleus. Eight individual dually innervated fibers were dissected from four transplanted mouse soleus muscles and examined with a transmission electron microscope. Z-lines in these dually innervated fibers were thinner (mean = 83 nm) than control soleus (mean = 123 nm) and thicker than control EDL (mean = 57 nm). A significant difference (p< .002) was also found between Z-line thickness near the foreign EDL endplate (mean = 81 nm) versus the original soleus endplate (mean = 85 nm). These results suggest the factors controlling protein synthesis in skeletal muscle fibers have both a global and localized effect.Department of Physiology and Health Science
25
Oguri, Joanna Ratna. "Applying all diligence from spiritual sloth to spiritual growth /." Theological Research Exchange Network (TREN), access this title online, 2004. http://www.tren.com/search.cfm?p091-0055.
Full text
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Sjöberg, Rebecca, and Berna Kilinc. "Upplevelser i livets slut : Ur ett patientperspektiv." Thesis, Mälardalens högskola, Akademin för hälsa, vård och välfärd, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-40137.
Full textAbstract:
Bakgrund:Att som patient befinna sig i livets slut är en subjektiv upplevelse, dock finns det generella drag. Det är därför relevant för sjuksköterskor att få kunskap om upplevelser i livets slut. Detta för att vägleda och ge stöd under patientens sista tid. Anhöriga kan uppleva rädsla då de vistas med sin familjemedlem, då de var oroliga över att deras familjemedlem skulle avlida i deras närvaro. Problem: Aktuell forskning visar på brister i vården gällande livets slut. Det fanns en bristande delaktighet i samtalet kring patientens tillstånd. Syfte: Var att beskriva patienters upplevelser i livets slut. Metod: Detta är en systematisk litteraturstudie med beskrivande syntes där 11 vetenskapliga artiklar har analyserats. Resultat: Analysen resulterade i två teman vilka var lindrat lidande och lidande. Inom dessa teman skapades fem subteman: lindrat lidande genom tro, lindrat lidande genom acceptans, lindrat lidande genom sociala relationer, lidande genom att förlora sitt jag, lidande genom att inte vara färdig med livet, lidande genom oro för framtiden och lidande genom att uppleva smärta. Slutsats: Patienter upplevde både ett lidande och lindrat lidande i livets slut. Variationer av upplevelserna kunde bero på åldersgrupper och etniskt ursprung.
27
Skácelová, Pavlína. "On-line marketingová komunikace." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2021. http://www.nusl.cz/ntk/nusl-443104.
Full textAbstract:
The subject of this diploma thesis is online marketing communication using search engine marketing tools. It specifies what online marketing and search engine marketing are, describes its tools and explains its use. The analytical part of the work uses tools such as analysis of macro and micro environment, analysis of marketing mix and associated SEO analysis. Last but not least, the development of website traffic and the subsequent possible development of this data in the future will also be examined. Based on the findings from the analytical part, in the last part of the work will be designed online marketing communication using search engine marketing.
28
Mitsuoka, Hirokazu. "Interleukin 18 stimulates release of soluble lectin-like oxidized LDL receptor-1(sLOX-1)." Kyoto University, 2008. http://hdl.handle.net/2433/124235.
Full text
29
Wang, Bing-Hsiao, and 汪秉孝. "Broadband Slot Arrays Fed by Microstrip Line." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/15910676299809835340.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
96
The broadband designs of half-wavelength slot array and quarter-wavelength slot array are proposed in this thesis. The slot elements are offset-fed by microstrip line to obtain the wider impedance bandwidth. Furthermore, the impedance bandwidth of the array antennas which composed of the slot elements can be wider. It can be kept stable that the radiation gain and the radiation pattern of the proposed half-wavelength slot array in the impedance band. Besides, it is formed a quasi-open circuit of the slotline by the truncated ground plane. The size of the slot element and the composed array can be compact, and the impedance bandwidth can be improved. Plane sheet is used as a reflector to make the slot array unidirectional radiation. The bandwidth of the proposed quarter-wavelength slot array is wider than the half-wavelength slot array. And it is also kept stable that the radiation gains and the radiation pattern. A plane sheet is used as a reflector which cancels the backed radiation and improves the radiation gain to make the slot array unidirectional radiation. The design details of the above slot array antennas are depth discussed in this thesis and are proved with the simulation and measurement results.
30
Wang, Bing-Hsiao. "Broadband Slot Arrays Fed by Microstrip Line." 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2207200814425800.
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31
LIU, WEI TIRNG, and 劉威廷. "STUDIES OF A MICORSTRIP-LINE-FED SLOT ANTENNA." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/02921121918745017631.
Full textAbstract:
碩士國立中山大學
電機工程研究所
84
This thesis presents an experimental study of the impedance property of a printed microstrip-line-fed slot antenna. Various configurations of the printed slot antennas are constructed, including the printed slot loaded with a dielectric covere or mounted on a cylindrical surface. Effects of the dielectric cover and curvature variation on the slot impedance are analyzed. The printed slot antennas with different slot shapes, e.g., the dumbbell slots and the H-shape slots, are also constructed to analyze the effects of different slot edge shapes on the slot impedance. In additioin to the experimental sutdies, the reciprocity analysis incorporating the exact Green' s-function formulation for a narrow rectangular printed slot is also described. Theoretical results of the slot impedance are also calculated, and good agreement between theory and experiment is observed.
32
Fu-Mao, Hsieh, and 謝馥懋. "The Design of Microstrip-Line-Fed Printed Slot Antenna." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/74375620362534848658.
Full textAbstract:
碩士南台科技大學
電子工程系
93
The novel designs of printed slot antennas for broadband characteristic have been investigated in this thesis. About this thesis, the designs of printed slot antennas all adopt the method of microstrip-line-fed, they can be classified into two main types of microstrip-line-fed isosceles triangular slot antenna and rectangular slot antenna, and impedance bandwidth of these proposed designs can achieved 77% and 104%, respectively. To begin with, the microstripline feed isosceles triangular slot antenna for broadband operation, the proposed antenna with a small rectangular slot of dimensions L×W, loaded on vertex of the isosceles triangular slot and centered above the microstrip feed line. Under the new structure, the proposed antenna leads to the advantages of broadband, high antenna gain and good co-polarization level. Next, to base on the broadband design of the isosceles triangular slot, we design a structure of rectangular slot antenna with a small trapezoid slot and to perform the purpose of broadband operation. Naturally, we focus on the characteristics of impedance matching, radiation patterns and antenna gain to analyze and study, too.
33
KORZENIOWSKI, THOMAS LEO. "A 94 GHZ IMAGING ARRAY USING SLOT LINE RADIATORS." 1985. https://scholarworks.umass.edu/dissertations/AAI8602654.
Full textAbstract:
A planar endfire slotted-line antenna structure has been experimentally investigated. It was found that the H-plane beamwidths are basically dependent upon the substrate properties, whereas the E-plane beamwidths are more strongly a function of the slot's shape and size. It is shown that these antennas produce symmetrical E- and H-plane beamwidths while following Zucker's standard traveling-wave antenna beamwidth curves over some range of antenna normalized length. An empirically derived design formula for effective substrate thickness is shown to predict this range for linearly tapered slotted-line antennas. These antennas were subsequently arrayed and mutual impedance data measured with a vector network analyzer and infered from their measured single element and arrayed radiation patterns. It was found that the antennas could be spaced up to 1.5 wavelengths before mutual impedance could be measured using the vector network analyzer and up to 2.5 wavelengths before any change in the radiation patterns were found. Arrays of these LTSA antennas were constructed for operation at 94 GHz with inter-element spacings of 1.5 and 2.5 wavelengths and evaluated with a Cassegrain reflector antenna. The experimental imaging properties of these arrays were presented and imaging theory was discussed. It was shown that a minimum spacing of elements is necessary for exact reconstruction of a sampled image in a diffraction limited system. Because these LTSA elements employ the traveling-wave mechanism of radiation, they can be spaced two times closer than a conical feed horn of comparable beamwidth. An LTSA array with 2.0 wavelength inter-element spacing would be capable of exact image reconstruction when used in a complex E-field sampling system.
34
Lin, Chi-Jang, and 林琦璋. "AN EXPERIMENTAL STUDY ON THE RADIAL LINE SLOT ARRAY ANTENNAS." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/72846956102436720292.
Full textAbstract:
碩士大同大學
通訊工程研究所
89
Developments of the DBS (Direct Broadcast from Satellites) operated at the X band have an increasing growth in many countries. The parabolic reflector antennas are commonly used as the received antennas for DBS. Although the gain of the parabolic reflector antennas is over 30dB, the large structure and the curved surface make some troubles in use. The planar reflectarray antennas had been proposed in order to overcome drawbacks of the curved surface. However, large structure and low efficiency still cause problems. In this thesis, we introduce the radial line slot array (RLSA) antennas that can also used for the DBS. They are somewhat similar to a class of slotted waveguide antennas, and the operating frequencies as well as polarization are determined by slots located on special positions. The RLSA not only reduce the size of antennas but also have advantages of high gains and high directivities. This thesis introduces both linearly and circularly polarized RLSA antennas, and have more detailed discussions on gains and other properties of the RLSA fed by the feedhorn. We will also compare with the differences between the RLSA antennas fed by the coaxial cables and the feedhorn.
35
Hsu, De-Fu, and 徐德福. "The study of the meander-line antenna and spiral slot antenna." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/wn6887.
Full textAbstract:
碩士逢甲大學
電機工程所
91
In this thesis, the dual band meander-line antenna and microstrip spiral slot antenna have been studied. In Chapter 2, we presented the design of the antenna possessing two ISM bands by folded the microstrip line around the LTCC substrate to miniaturize the antenna size. In Chapter 3, we demonstrated one technique to reduce the initial resonant frequency and enhance the bandwidth of the spiral slot antenna without enlarging the antenna area. By adding a circularly capative stub at the end of the antenna, the initial resonant frequency has been lowered from 1.59 GHz to 1.28 GHz. In other words, the antenna area is reduced by 20%, approximately.
36
Ye, Yu-Ting, and 葉昱廷. "Design of Group Delay Lines with All-pass Response Using Embedded Stubs and Non-coplanar Slot-line." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/79013325502767973185.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
103
A new method to implement an all-pass phenomena by microstrip technology where two shunted stubs are attached to the 50Ω line and a slot-line is produced on the ground planar. The advantage of the new method is lowering the substrate area and obtaining the same all-pass result as possible. Originally, a transmission line with one or two shunted stubs implement a band-stop phenomena as a frequency filter；meanwhile, the central frequency is dependent on the stub physical length, and the bandwidth changes with the stub width which determines the impedance. Then, theoretically there exists a corresponding slot-line carve on the ground planar, which performs as the same filter independently. The open stubs and slot-line should have the same central frequency. After combining the open stubs and the slot-line planar, an all-pass phenomena occurs. Another breakthrough is the reference position between open stubs and slot-line. Generally, the open stubs had better locate right above the slot-line in order to get all-pass phenomena. This research is to find out whether it is possible to shift the reference position of both and obtain all-pass result.
37
liao, Zhi-Wei. "Design and Measurement Setup of 38 GHz CPW-Fed Meander Line Slot Antenna Array." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1007200402065700.
Full text
38
liao, Zhi-Wei, and 廖志威. "Design and Measurement Setup of 38 GHz CPW-Fed Meander Line Slot Antenna Array." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/28317498655837144212.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
92
Recently, uniplanar antennas have been used in many applications in millimeter-wave systems. In this dissertation, we focus on the design of the CPW-fed meander line slot antenna array for operational frequency band from 38 to 38.5 GHz. Our design goal is to achieve a high gain antenna array. We utilize two kinds of short-stub as tuning networks to tune the high input impedance of the array to match the characteristic impedance of the feeding CPW. The main beam of a high gain antenna array is usually very narrow. To make the correct measurement, it must be ensured that the antenna array stands still against the rotation of a swivel table, which may lead to a measurement error. For this reason, we make a mechanized clamping apparatus to combine the swivel table, the antenna array, and the K-connector together. It is placed on the swivel table in the anechoic chamber in order to connect the signal part of both the K-connector and the antenna array. When the swivel table is driven by a motor, it will not be vacillating and staggering. Therefore, we can reduce the error of our measurement. To check the accuracy of our design, a planar meander line slot array with a matching circuit is fabricated and tested. From experimental results, this antenna array is proved to be practical and useful.
39
Hou, You-min, and 侯佑民. "The design and investigation of a wideband common-mode rejection filter using slot line structure." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/82685450792311567788.
Full textAbstract:
碩士國立臺南大學
電機工程學系碩士班
101
Two new defected ground structures (DGSs) are proposed to realize a high performance filter for suppressing common-mode noise in high-speed circuit design. One common-mode rejection filter is designed and fabricated based on the meander slot line structure (MSLS). The phi-shaped slot line structure which consists of three kinds of resonators is implemented and integrated into another filter design. The diverse parameters and coupling effects of these two common-mode rejection filters are required to be analyzed and investigated for creating the equivalent circuit model. To reduce the area of the traditional DGS structure, the resonator is further modified. With the wavelength fixed, the slower the phase velocity, the lower the resonant frequency. By increasing the coupling strength between two resonators, the occupied area and suppression bandwidth of the conventional common-mode suppression filter are improved. Compared with the equivalent circuit model, both simulation and measurement results are in good agreement. The insertion loss is of less than -15dB ranged from 2.6GHz to 7.4GHz and the overall size is 0.52λg * 0.43λg in the meander slot line structure. The stop-band bandwidth ratio of 96% is obtained. The insertion loss is of less than -15dB ranged from 2.8GHz to 8.8GHz and the overall size is 0.21λg * 0.23λg in the phi-shaped slot line structure. The stop-band bandwidth ratio of 103% is obtained. Furthermore, it is observed that the proposed two common-mode rejection filters reached more than 87% and 82% in the suppression of common-mode voltage in the time domain analysis, respectively. The phi-shaped type filter can provide better size reduction of 78% than the meander type filter.
40
Chen, Wen-Lang, and 陳文郎. "Research and Fabrication of Ultra Wide-Band (UWB) Bandpass Filters Using Parallel Coupled Microstrip Lines and Slot Line Resonators (SLRs)." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/86043474673243819965.
Full textAbstract:
碩士南台科技大學
光電工程系
97
This thesis presents parallel coupled lines UWB bandpass filters for ultra-wideband communication system. Those are short-circuited parallel coupled bandpass filter, open-circuited parallel coupled bandpass filter, a diplexer and a stop band improvement UWB Bandpass filter, respectively. The response characteristic of short-circuited and open-circuited parallel coupled lines are exhibited all stop frequency response and the stop band appeared at 3f0 and 2f0, respectively. The central frequencies of open-circuited and short-circuited parallel coupled lines are designed at 4 GHz and 8 GHz which the electrical lengths are quarter-wavelength and half-wavelength, respectively. The short-circuited and open-circuited of parallel coupled lines are coupled to the electrical length 1800 of slot-line resonator (SLR) which can produce low band (3~5 GHz) and high band (6~10 GHz) bandpass filters for UWB application, respectively. A diplexer is designed to combine the proposed two BPFs by using microstrip impedance match which the operating frequencies are 3.2 ~ 4.8 GHz for low passband and 6.5 ~ 9.8 GHz for high passband, respectively. In additional, a novel wide stopband filter is proposed using a pair of shunt and embedded open stubs which connected the input and output ports with the UWB BPF to improve the harmonic response. A wide stopband of the proposed BPF from 10 to 20 GHz can be achieved. Final, this thesis proposes a dual-band BPF using ring open-loop resonator for wireless communication network which the operating frequencies are at 2.4 GHz and 5.7 GHz, respectively. The proposed dual-band BPF has compact, low insertion loss, good stopband response and easy fabrication. Experiment and measurement results are in good agreements with simulation results.
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Chang, Chien Hung-Hsieh, and 張簡宏劦. "Studies on Dual-band Circularly-polarized Slot Antennas with Double-bend Feeding Line for UAV Applications." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/33465066361944103246.
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碩士國防大學理工學院
航空太空工程碩士班
99
A dual-band circularly polarized (CP) printed slot antenna with a tunable frequency-ratio range is proposed in this thesis. The proposed antenna design which can find applications on UAV (Unmanned Aerial Vehicle) features a ring slot etched on ground plane, the two coupling slots beneath the ring slot, the embedded spurs-like-shaped strip in the ring slot, a double-bend feeding line and a rectangular pad connected with the feeding line for improving the impedance match of the lower frequency band. The spur-like-shaped strip can be employed to create a higher CP frequency band without deteriorating the performance of original lower CP frequency band which causes a broadband or dual-band CP performance.
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Chu, Pei-Chun, and 朱培均. "Analysis and Design of Planar Slot-Line Four Ports Crossover and Planar Double Ring Eight Ports Crossover." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/q2yv7h.
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碩士國立中正大學
電機工程研究所
103
The thesis includes six chapters，The first chapter primarily introduce our motivation of research and discussion document. In second chapter will introduce the basic theory detaily that relative to our research. Transmission line (ABCD) matrix、S parameter theory analysis and even odd mode analysis will be introduce sequentially. Then we will introduce crossover in third chapter. Branch line coupler will introduce first, introducing its basic theory and history. After that, we will introduce the traditional crossover which series by two branch line couplers. In the fourth chapter, a planar slot line crossover will introduced, including integral theory and implement. Then, an eight ports crossover which has four channels will be introduced in chapter five. And we will implement two kind of eight ports crossovers. These two crossovers are little deferent in design parameter. In these chapter, the integral theory also included. The conclusion is in chapter six.
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Alibakhshikenari, M., B. S. Virdee, C. H. See, Raed A. Abd-Alhameed, F. Falcone, and E. Limiti. "Surface wave reduction in antenna arrays using metasurface inclusion for MIMO and SAR systems." 2019. http://hdl.handle.net/10454/18126.
Full textAbstract:
YesAn effective method is presented for suppressing mutual coupling between adjacent radiating elements which is based on metasurface isolation for MIMO and synthetic aperture radar (SAR) systems. This is achieved by choking surface current waves induced over the patch antenna by inserting a cross-shaped metasurface structure between the radiating elements. Each arm of the cross-shaped structure constituting the metasurface is etched with meander-line slot (MLS). Effectiveness of the metasurface is demonstrated for a2×2antenna array that operates over six frequency sub-bands in X, Ku and K-bands. With the proposed technique, the maximum improvement achieved in attenuating mutual coupling between neighbouring antennas is: 8.5 dB (8-8.4 GHz), 28 dB (9.6-10.8 GHz), 27 dB (11.7-12.6 GHz), 7.5 dB (13.4-14.2 GHz), 13 dB (16.5-16.8 GHz) and 22.5 dB (18.5-20.3 GHz). Furthermore, with the proposed technique (i) minimum center-to-center separation between the radiating elements can be reduced to 0.26λ0, where λ0 is 8.0 GHz; (ii) use of ground-plane or defected ground structures are unnecessary; (iii) use of short-circuited via-holes are avoided; (iv) it eliminates the issue with poor front-to-back ratio; and (v) it can be applied to existing arrays retrospectively.
H2020-MSCA-ITN-2016 SECRET-722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E0/22936/1
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Zhu, F., S. Gao, A. T. S. Ho, Raed A. Abd-Alhameed, Chan H. See, T. W. C. Brown, J. Li, G. Wei, and J. Xu. "Multiple Band-Notched UWB Antenna With Band-Rejected Elements Integrated in the Feed Line." 2013. http://hdl.handle.net/10454/9770.
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NoTo mitigate potential interferences with coexisting wireless systems operating over 3.3-3.6 GHz, 5.15-5.35 GHz, or 5.725-5.825 GHz bands, four novel band-notched antennas suitable for ultra-wideband (UWB) applications are proposed. These include UWB antennas with a single wide notched band, a single narrow notched band, dual notched bands, and triple notched bands. Each antenna comprises a half-circle shaped patch with an open rectangular slot and a half-circle shaped ground plane. Good band-notched performance is achieved by using high permittivity and low dielectric loss substrate, and inserting quarter-wavelength horizontal/vertical stubs or alternatively embedding quarter-wavelength open-ended slots within the feed line. The results of both simulation and measurement confirm that the gain suppression of the single and multiple band-notched antennas in each desired notched band are over 15 dB and 10 dB, respectively. The radiation pattern of the proposed triple band-notched design is relatively stable across the operating frequency band.
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Majeed, Asmaa H., Abdulkareem S. Abdullah, Fauzi Elmegri, Khalil H. Sayidmarie, Raed A. Abd-Alhameed, and James M. Noras. "Dual Segment S-Shaped Aperture-Coupled Cylindrical Dielectric Resonator Antenna for X-Band Applications." 2015. http://hdl.handle.net/10454/7885.
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yesA new low-cost dual-segmented dielectric resonator (DR) antenna design is proposed for wideband applications in the X-band region. Two DRs coupled to an S-shaped slot introduce interesting features. The antenna performance was characterized in terms of the reflection coefficient, gain, and radiation pattern, and detailed simulation studies indicate excellent antenna performance from 7.66 GHz to 11.2 GHz (37.5% fractional bandwidth) with a maximum gain of 6.0 dBi at 10.6 GHz while the fabricated prototype has a matched bandwidth from 7.8 GHz to 11.85 GHz (41% fractional bandwidth) and maximum gain of 6dBi. The antenna is compact, size 1 x 0.83 x 0.327 time the wavelength at 10 GHz. The two DR segments may be located on the same side or on opposite sides of the substrate, giving respectively improved gain or more uniform field patterns. Experimental testing of the prototype performance showed reasonable agreement with the predicted performance.
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"Applications of Kinetic Inductance: Parametric Amplifier & Phase Shifter, 2DEG Coupled Co-planar Structures & Microstrip to Slotline Transition at RF Frequencies." Master's thesis, 2016. http://hdl.handle.net/2286/R.I.38648.
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abstract: Kinetic inductance springs from the inertia of charged mobile carriers in alternating electric fields and it is fundamentally different from the magnetic inductance which is only a geometry dependent property. The magnetic inductance is proportional to the volume occupied by the electric and magnetic fields and is often limited by the number of turns of the coil. Kinetic inductance on the other hand is inversely proportional to the density of electrons or holes that exert inertia, the unit mass of the charge carriers and the momentum relaxation time of these charge carriers, all of which can be varied merely by modifying the material properties. Highly sensitive and broadband signal amplifiers often broaden the field of study in astrophysics. Quantum-noise limited travelling wave kinetic inductance parametric amplifiers offer a noise figure of around 0.5 K ± 0.3 K as compared to 20 K in HEMT signal amplifiers and can be designed to operate to cover the entire W-band (75 GHz – 115 GHz).The research cumulating to this thesis involves applying and exploiting kinetic inductance properties in designing a W-band orthogonal mode transducer, quadratic gain phase shifter with a gain of ~49 dB over a meter of microstrip transmission line. The phase shifter will help in measuring the maximum amount of phase shift ∆ϕ_max (I) that can be obtained from half a meter transmission line which helps in predicting the gain of a travelling wave parametric amplifier. In another project, a microstrip to slot line transition is designed and optimized to operate at 150 GHz and 220 GHz frequencies, that is used as a part of horn antenna coupled microwave kinetic inductance detector proposed to operate from 138 GHz to 250 GHz. In the final project, kinetic inductance in a 2D electron gas (2DEG) is explored by design, simulation, fabrication and experimentation. A transmission line model of a 2DEG proposed by Burke (1999), is simulated and verified experimentally by fabricating a capacitvely coupled 2DEG mesa structure. Low temperature experiments were done at 77 K and 10 K with photo-doping the 2DEG. A circuit model of a 2DEG coupled co-planar waveguide model is also proposed and simulated.Dissertation/Thesis
Masters Thesis Electrical Engineering 2016
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CAI, BING-XIU, and 蔡秉修. "Design of Yagi-Like Multilayered Slot Antenna." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/4u498v.
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碩士南臺科技大學
電子工程系
107
This thesis proposes two antenna designs of Yagi-like multilayered slot antennas. In order to solve for the blind spot on the signal coverage, designs of Yagi-like multilayered slot antennas will be proposed. The high gain antenna design is used to solve the problem. In the introduction, the principle of the Yagi antenna will be surveyed and understood. And, then a design of a slot Yagi-like multilayered antenna and a design of dual-polarization Yagi-like multilayered slot antenna will be proposed: In the first case, a design of slot Yagi-like multilayered antenna for WRC 5G C-band (3.4 – 3.6 GHz) has been proposed. The overall size is 42 mm × 42 mm × 60 mm. The antenna consists of a ring-shaped slot, two directors by using ring-shaped slot, and a T-shaped feeds on the back to excite slot antenna. The introduction of the director 2 with a thin PLA (Polylactic Acid) coating enhances the impedance match. In the second case, a design of dual-polarization Yagi-like multilayered slot antenna for WRC 5G C-band (3.4 – 3.6 GHz) has been proposed. The antenna consists of a ring-shaped slot, two directors by using ring-shaped slot, a pair of double L-shaped feeds on the back to excited slot antenna and a reflective element, which is forming a design of vertically stacked antenna. The overall size of Yagi antenna is 42 mm × 42 mm × 60 mm. The introduction of the director 2 with a thin PLA (Polylactic Acid) coating and with 8 small circular apertures located on the slot is to enhance the impedance match.
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MASTRANTONI, ELISA, and Daniela Melchiorri. "ISOLATION OF SLOW CYCLING STEM-LIKE MELANOMA SPHERES FROM mGluR1 POSITIVE MELANOMA CELL LINE." Doctoral thesis, 2012. http://hdl.handle.net/11573/918057.
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Human malignant melanoma is a highly aggressive and drug-resistant tumour of neuro-ectodermal origin. Tumor heterogeneity, undifferentiated molecular signatures, and increased tumorigenicity of melanoma subsets with embryonic-like differentiation plasticity, strongly suggests the presence and involvement of cancer a stem cells in the initiation and propagation of melanoma. Parallel to the role that normal stem cells play in organogenesis, cancer stem cells are thought to be crucial for tumorigenesis. Many investigators, indeed, propose that melanoma stem cells (MSCs) may be responsible for tumour chemoresistance, invasiveness, and neoplastic progression and that targeted abrogation of a MSCs population could therefore ultimately lead to stable remissions and perhaps cure of metastatic melanoma. However, the high percentage of cells expressing different markers of undifferentiated and partially differentiated stages that form the bulk of the melanoma tumour has made the isolation of melanoma stem cells a challenging goal. In fact, no peculiar marker of stemness has been identified so far that may consistently flag up a stem cell population different from the highly heterogenic melanoma cell population.
Glutamate has been proposed to play an important role in the in biology of stem/progenitor cells (Melchiorri et al, 2007) and cancer-initiating stem cells (Nicoletti et al., 2007, Ciceroni et al, 2008). Results from previous studies suggest that the ectopic expression of the type 1 metabotropic glutamate receptor gene (GRM1) is sufficient to transform melanocytes in vitro and cause malignant melanoma in vivo (Pollock et al. 2003). In addition, it has been documented that the GRM1 gene is aberrantly expressed in about 60% of human melanomas cell lines and biopsies (Pollock et al. 2003, Ortiz P. 2007).
By culturing the type 1 metabotropic glutamate receptor-positive metastatic melanoma cell line, C8161, under conditions that are known to allow the isolation of neural stem cells, we were able to isolate a highly tumorigenic, drug resistant, slow-cycling cell population that could represent a good cell model to study Melanoma resistance and recurrence both in vitro and in vivo.
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Spirit, The Congregation of the Holy. "Spiritan Life -- Number 01." 1989. http://digital.library.duq.edu/u?/slst,100.
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Spiritan Life No. 01 -- 1989 December -- Mission Sources Justice and Peace Number 1 -- CONTENTS -- Foreword -- (pg 5) -- Introduction -- (pg 7) -- The Seminary of The Holy Spirit During The French Revolution (1789 - 1799), by Jean Godard, C.S.Sp. -- (pg 9) -- True Spirituality... Really Authentic and Genuine, by Eugene Hillman, C.S.Sp. -- (pg 45) -- The Holy Spirit and The Congregation, by Michael O'Carroll, C.S.Sp. -- (pg 57) -- Towards A Spiritan Identity, by Maurice Gobeil, C.S.Sp. -- (pg 67) -- Dialogue Between Christians and Muslims, by Robert P. Ellison, C.S.Sp. -- (pg 69) -- The Land War in Brazil, by Michael Drohan, C.S.Sp. -- (pg 79) -- Spiritan Witness at The Frontiers, by Brian O'Rourke, C.S.Sp. -- (pg 85) -- Spiritan Life Review -- (pg 91) -- Other Works by Spiritans -- (pg 95)
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Spirit, The Congregation of the Holy. "Spiritan Life -- Number 09." 1999. http://digital.library.duq.edu/u?/slst,1002.
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Presence and Solidarity -- Spiritan Life No. 9 -- September 1999 -- CONTENTS -- Editorial -- (pg 1) -- In the Steps of our Founders Bernard Reniers -- (pg 3) -- Those who have gone before us Henry Koren -- (pg 11) -- Living with Street Children Vincent Chopart -- (pg 21) -- In Durban's Hostels for Migrant Workers Jose Sabenca -- (pg 31) -- Good News and Solidarity Rene You -- (pg 39) -- Living with Refugees Armel Duteil -- (pg 45) -- Overwhelmed by Suffering Frezy Tam-Tsi -- (pg 51) -- Lay Associates working with Young Children Daniel Fasquelle & Pierre Sornay -- (pg 57) -- Reflection Article Gabriel Mbilingi -- (pg 65)