391 |
Transitions from substrate integrated waveguide to planar transmission lines and their applications to amplifier integrationTaringou, Farzaneh 03 October 2012 (has links)
In the lower millimetre-wave frequency range, Substrate Integrated Waveguide (SIW) circuits have emerged as a reasonable compromise between rectangular waveguide and standard microstrip technologies. They are formed by a top- and bottom-metalized substrate and two arrays of plated or riveted holes (via holes) to replace the vertical metallic walls in conventional rectangular waveguide. Although many passive components known from traditional waveguide technology have been fabricated in SIW, one of the main challenges is to integrate active components with typical coaxial-type interfaces within the SIW environment.
Therefore, the work presented in this dissertation focuses on new broadband transitions from SIW to other planar transmission-line technologies such as microstrip coplanar waveguide, coplanar strip line, slot line and coupled microstrips. Several of the new transitions are prototyped and experimentally verified. Two of these transitions are then used to integrate a low noise amplifier within SIW input and output ports. The measurements of fabricated SIW amplifier prototypes show very promising performance and clearly demonstrate successful integrations of active components within SIW. Finally, one of the new SIW-to-coplanar-waveguide transitions is employed as an interface to an SIW-based antenna, thus demonstrating the principle of connectivity of SIW to all currently used planar circuit technologies. / Graduate
|
392 |
Active Followership: An Essential Component of the Teacher-Principal RelationshipAmmon, Robert Darwin Nigel 04 September 2013 (has links)
Arguably, the leadership demonstrated by a school principal determines the success of an educational organization, a school. This viewpoint, grounded in literature, maintains that the role of a leader (school principal) determines the effectiveness of followers (teachers). While accurate, this premise does not consider the role of followers to influence the significance of the leader. Therefore, it is appropriate to examine the teacher-principal relationship from the perspective of the follower. Specifically, what motivates teachers to follow a school principal? A qualitative research design was employed; data collection consisted of interviews, a questionnaire and survey, where a limited number of semi-structured open-ended questions were posited. Conclusively, the study identified an exemplary followership style as predominant among participants (followers), and several specific and general professional qualities and personal characteristics, expected and modeled by principals (leaders). Collectively, style, criteria, and rationale established that active followership is an essential component of the teacher-principal relationship. / Graduate / 0525 / rammon@uvic.ca
|
393 |
Vadovavimas procesui / Active management of procedureGrigonytė, Vaida 29 December 2006 (has links)
The aim of this master paper is to reveal the role of a judge. In the first part of the paper the ideas of social civil procedure school (that is essential in the Lithuanian Republic Civil procedure code) defining an active role in civil procedure and the model of civil procedure of Lithuanian Republic are discussed. The second part of the paper deals with analysis of stages of the civil procedure. By analyzing these stages the author of the paper tries to disclose by which means provided in law the judge realizes his (hers) performing role in the procedure. Also the intensity of the judge role depending on the stage of the civil procedure is shown. Attention is paid to certain categories of cases that influence the extension of the judge’s activity and the difference of performing intensity depending on contentious proceedings as well. In the third part of the paper the possibilities of making default judgment and judicial penalties assigning as means helping to control parties that overindulge processing right or do not care about the progress of proceedings are discussed.
|
394 |
Active Space Debris Removal using Capture and EjectionMissel, Jonathan William 03 October 2013 (has links)
Low Earth Orbit is over-cluttered with rogue objects that threaten existing technological assets and interfere with allocating new ones. Traditional satellite missions are not efficient enough to collect an appreciable amount of debris due to the high cost of orbit transfers. Many alternate proposals are politically controversial, costly, or dependent on undeveloped technology. This dissertation attempts to solve the problem by introducing a new mission architecture, Space Sweeper, and bespoke hardware, Sling-Sat, that sequentially captures and ejects debris plastically. Resulting momentum exchanges are exploited to aid in subsequent orbit transfers, thus saving fuel. Sling-Sat is a spinning satellite that captures debris at the ends of adjustable-length arms. Arm length controls the angular rate to achieve a desired tangential ejection speed. Timing the release exacts the ejection angle. This process redirects debris to burn up in the atmosphere, or reduce its lifetime, by lowering its perigee.
This dissertation establishes feasibility of principles fundamental to the proposed concept. Hardware is conceptualized to accommodate Space Sweeper ’s specialized needs. Mathematical models are built for the purpose of analysis and simulation. A kinematic analysis investigates system demands and long-term behavior resulting from repeated debris interaction. A successful approach to enforce debris capture is established through optimal control techniques. A study of orbital parameters and their response to debris interactions builds an intuition for missions of this nature. Finally, a J2-compliant technique for path optimization is demonstrated. The results strongly support feasibility of the proposed mission.
|
395 |
The effects of surfactants on the solid substrate fermentation of potato starch /Góes, Ana Paula. January 1999 (has links)
The potential of surfactants for improving the yields of alpha-amylase during the solid substrate fermentation (SSF) of potato starch using pure and mixed cultures was examined. The microorganisms used in this study were Aspergillus oryzae ATCC 1011, Bacillus subtilis ATCC 21556 and Bacillus subtilis ATCC 21332. The surfactants tested were Tween 20, Tween 80, SDS and surfactin. The fermentations were carried out in perforated trays after the addition of 10% (v/w) inoculum and with temperature and humidity controlled at 30°C and 90% RH respectively. Samples were taken and analyzed quantitatively for the production of alpha-amylase and biomass and qualitatively by scanning electron microscopy (SEM) using a JSM-840 A scanning microscope at 10 kV accelerating voltage. / It was possible to increase fungal alpha-amylase production by as much as 6 fold in the process with the addition of either synthetic surfactants or the biosurfactant surfactin. The bacterial alpha-amylase yields increased up to 11.5 fold in with the addition and/or the co-culture production of surfactants. The highest enzyme activity was found in the fermentation of a mixed culture of the two Bacillus strains with the addition of Tween 80. During the SSF with B. subtilis ATCC 21332 and ATCC 21556 as a mixed bacterial culture, there was also the production of surfactin in yields comparable to those obtained in a submerged fermentation. The biofilm formation as observed by SEM appeared to be associated with the presence of surfactants in the process and was not formed when no surfactants were present. The biofilm was observed as an entrapment of the bacteria in the substrate, resulting in improved access to the starch and higher production of alpha-amylase.
|
396 |
An Analysis of Stated and Revealed Preference Cycling Behaviour: A Case Study of the Regional Municipality of WaterlooRewa, Kyrylo Cyril January 2012 (has links)
Amongst transportation professionals there is a motivation to increase the use of active transportation to achieve contemporary transportation engineering goals. This research describes a year-long GPS cycling study conducted in partnership by the University of Waterloo and the Region of Waterloo Ontario. Data were collected from 415 self-selected cyclists, using two distinct data collection mechanisms. Data collected from GPS units revealed trip origins, destinations, and routes; the data also contain time stamps from which travel speeds can be computed. An online survey was administered to gather cyclists’ socio-economic information and household composition. The survey also collected responses to questions regarding preferences for cycling infrastructure and overall satisfaction.
The trip data allow for several important conclusions. The average trip length observed in the study was 6.96 kilometers; utilitarian trips (i.e. non-recreational) constitute 92% of the observed trips. This suggests that cyclists are able to complete daily activities – commuting, shopping, etc. – with less overall travel than the general population. The trip data also suggests relationships between the propensity to cycle and land use patterns. Strong positive correlations are demonstrated between higher land use density and the number of cycling trips; moreover, cycling trips tend to be more direct in areas with traditional neighbourhood design. The time at which the trips were taken – predominantly the am or pm peaks – suggest that the cyclists’ mode choice results in lowering peak demand and, therefore, reducing regional congestion. Fewer and typically shorter cycling trips were observed during winter months, presumably as a result of less favorable climate.
Participants in the study are typically higher-than-average earners and mirror the overall regional age distribution, although seniors and children were underrepresented. The cyclists in the study are predominantly male which may reflect an overall higher propensity to cycle amongst men compared to women. Cyclists’ households are more likely than the general population to own fewer cars than licensed drivers which may be interpreted as a cost saving opportunities for these households. Finally, the survey data suggests that the single largest impediment to increased cycling is a perception of poor safety for cyclists, particularly in terms of interactions with automobiles.
|
397 |
Application of active inductors in high-speed I/O circuitsLee, Yen-Sung Michael 11 1900 (has links)
This thesis explores the use of active inductors as a compact alternative to the bulky passive spiral structures in high-speed I/O circuits. A newly proposed PMOS-based topology is introduced and used in active-inductor terminations. The 1st prototype design fabricated in a 90-nm CMOS process consists of an output driver using active-inductor terminations to provide channel equalization and output impedance matching. From measurement results, the use of active inductors in the termination, as compared to when the active inductor is disabled, increases the vertical eye opening in the receiver side by a factor of two and reduces the jitterp-p by 30% of the transmitted 10 Gb/s (2³¹-1) pseudo-random binary sequence pattern, over a 6-inch FR4 channel. An output impedance matching with S₂₂ less than -10 dB over a bandwidth of 20 GHz is achieved. The pair of active-inductor terminations occupies 17×25 µm² and has a low overhead power consumption of 0.8 mW. In the 2nd prototype design, a 4-stage output buffer with active-inductor loads is designed and implemented in a 65-nm CMOS process. Simulation results verify that when operating at 31.25 Gb/s, the output eye of the active-inductor load buffer compares favorably with that of the passive-inductor load buffer. For a similar eye-height and 78% less timing jitter the active-inductor load design’s speed (31.25 Gb/s) is 25% faster than the passive-resistor load design (25 Gb/s). The active-inductor load output buffer achieves comparable performance in terms of speed, power, and output swing with other reported designs using passive inductors. Its total area is 135×30 µm² (including three differential active inductors) which is comparable to the size of a single passive spiral inductor having a 0.5~1 nH inductance.
|
398 |
Constructions of an active language learner in English as a foreign language (EFL) teacher education in Vietnam /Dang, Hung Van. Unknown Date (has links)
This study investigates how an active language learner is constructed in the context of teacher education for teaching English as a foreign language (TEFL) in Vietnam, as well as the supportive factors and challenges in developing learner activeness in language learning. / Thesis (PhD)--University of South Australia, 2006.
|
399 |
The paradoxes of action learning :Herbert, Anne. Unknown Date (has links)
Thesis (PhD)--University of South Australia, 2001
|
400 |
Signatures of the propagation of primary and secondary cosmic ray electrons and positrons in the galaxy / Troy Anthony Porter.Porter, Troy Anthony January 1999 (has links)
Includes bibliographical references (8 p.) / ix, 173, [8] p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines some of the consequences of the acceleration and production, and propagation, of high energy electrons and positrons in the Galaxy. In particular, predictions are made of the diffuse photon signals arising from the interactions of electrons and positrons with gas, low energy photons, and the galactic magnetic field during their transport in the Galaxy. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1999
|
Page generated in 0.0216 seconds