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The Mixing Height (MH), Convective Condensation Level (CCL), and Convective Available Potential Energy (CAPE) are computed with different methods and we examined whether these parameters can help to discriminate between weak and strong convection. The observational data set contains soundings released from Stony Plain in Alberta and The Pas in Manitoba for the summers of 2006 and 2007. The major findings were: 1) The Mixing Height values computed with the Heffter method were reliable provided the critical inversion criterion was adjusted for Prairie conditions. 2) The Mixing Height values computed with the Moist Mixed layer method were in good agreement with Mixing Heights computed with the Heffter method. 3) The Mixing Height values computed with the Holzworth parcel method were less useful in that often the potential temperature did not decrease with height above the ground. 4) Observed convective cloud base heights tended to be lower than the CCL computed using the surface parcel method, the 50 mb mixed parcel method, and the moist mixed parcel method. 5) The MH, the sounding-based CCL, and the CAPE did not differentiate between weak and strong convection. 6) We derived a new parameter: the difference between the convective cloud base and the Moist Air Mixing Height. This parameter did discriminate between the likely occurrence of strong and weak convection.

Full time wheelchair users are at a height disadvantage during many function activities, such as transferring or reaching. Retrieving objects from the ground or a higher shelf while seated in the wheelchair can be both difficult and unsafe. Lateral transfers between surfaces at different heights can be difficult and unsafe. Sit-to-stand transfers are made simpler with a higher seat. This research project seeks to assist reach and transfers by designing a system to raise and lower a wheelchair seat over a 4'' range. The project included several needs assessment: 1) by conducting interviews and surveys, identify design needs from different stakeholder groups; 2) analysis of stakeholder groups' feedback and synthesis into design criteria; and 3) creation of design concepts for the adjustable height wheelchair seat; 4) evaluation of the design by setting up heuristic evaluation criteria and perform user testing; 5) design revision design based on user's performance and feedback. The design process included fabricating and testing of various concepts, validating design through user testing, and addresses technology transfer of the device.

Electroreflectance (ER) spectra of Schottky-barrier Au/n-GaN have been measured at various dc biased voltages (Vbias). The ER spectra have exhibited excitonic signals beneath band-gap energy (Eg ). In addition, Franz-Keldysh oscillations (FKOs) were also observed above Eg. The FKOs come from the former region, and the excitonic signals come from the latter region. When Vbias = 0, they are mixed. As reverse Vbias is increased, they become more separated. Furthermore, strength of surface electric field (Fs) can be deduced from the period of the FKOs. From the plot of versus Vbias, barrier height of 1.2 V and carrier concentration were obtained.

For the requirements of high-speed signal transmission has been increasing, the fiber array in the communication system has a lot of advantages which can not be replaced. But the loss of coupling efficiency is a difficult problem as the distance of communication is getting longer and longer. In order to increase the transmission and the coupling efficiency, we produce the two with high precision to reach the goal. The technique producing one dimension fiber array is very adept now. This paper chooses mounting several one dimension fiber array to produce the two dimension fiber array. Because BGA has self-alignment character, the fiber array can get nice mounting accuracy in horizontal but can¡¦t get in vertical. We use active packing to manufacture two dimension fiber. In this process we exert external force to control the mounting height. In the first, use approximate software to get the best manufacturing parameter. Then complete the experiment and compare the result with the approximation.

Abstract For the requirements of high-speed signal transmission has been increasing in the optical communication system ,so the fiber array in the communication system has a lot of advantages which can not be replaced. But the loss of coupling efficiency is a difficult problem as the distance of communication is getting longer and longer. The packaging quality of the fiber array module. In order to increase the transmission and the coupling efficiency, we produce the high precision to reach the goal. This paper use adhesive bonding technology to packageing of the fiber array module. But the adhesive had shrinkage and strength two problem. This paper presents a novel height and strength control strategy is constructed to fabricate one-dimensional optical fiber array. For the height,a active-alignment technique is used and shrinkage control and pick adhesive parameter can improve accuracy to displacement distance is below 1£gm in the work tempeture.For the strength of the adhesion¡Aa way to use different kind temperature in the work can add adhesion's strength. After work use to replace temperature in order to add strength. All the improvements of the above packading technologies are proposed to raise or keep the performance of the fiber array module.So,the error between theories and experiments can be minimized.Meanwhile,a high stability and repeatability of the packaging can be achieved due to the automation of the positioning force sensing,andinspection.

For the future development of optical fiber communication needs to develop high optical coupling of the optical transceiver module. We focus on enhancing the optical efficiency of array optical transceiver module, and improve the way is used rotation axis instead of ordinary xyz translation. In the paper the use of solder packaging technology packaging optical transceiver module. And take the characteristics of solder packaging to control the angle, so that module can produce offsets in the radial direction,and original structure packed module can be further increased the rate of coupling efficiency.

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A detailed review of existing flying height or head disk spacing testing techniques has been made, and in-depth analyses of the working principles of the currently popular optical interferometry flying height testing methods are presented with simulation results. A new dual-beam normal incidence polarisation inteferometry method is then proposed. One advantage of this dual-beam polarisation interferometry is that it can be used for both the direct spacing measurement (DSM) method and relative displacement measuring (RDM) method. The RDM method is a good way to measure the head-disk spacing and the slider pitch or roll when a real magnetic disk is used for testing. The DSM method has the advantage that the absolute head-disk spacing can be observed and measured directly, especially in the case where it is difficult for the light beam to 'spot' the back surface of the head-slider. When used for the DSM method, the flying height can be measured down to contact without losing sensitivity. Slider pitch or roll can also be measured using the phase information. Another advantage of this polarisation interferometry is that, when used for the DSM method, with the measured intensity and phase information, the optical constants of the slider material can be determined, which is necessary to determine the flying height. By investigation of the application limits and potential problems of the intensity interferometry method, an improved intensity interferometry method is also proposed by using phase-shifting technique to improve the sensitivity of this method when the head-disk spacing is below 10 nm and near contact. An experimental testing system has been built to test the capability and effectiveness of the proposed interferometry methods. Experimental results are presented which show good agreement with the results gained from theoretical analyses and simulation.

As magnetic computer disks are developed to ever-greater data storage densities, the accuracy required for head positioning is moving beyond the accuracy provided by present technology using single-stage voice-coil motors in hard disk drives. This thesis details work to develop a novel active suspension arm with 2-dimensional actuation for use in advanced hard disk drives. The arm developed is capable of high-bandwidth data tracking as well as precision head flying height control motion. High-bandwidth data tracking is facilitated by the use of piezoelectric stack actuator, positioned closer to the head. The suspension arm is also capable of motion in the orthogonal axis. This motion represents active flying height control to maintain the correct altitude during drive operation. To characterise the suspension arm's structural dynamics, a high-resolution measurement system based on the optical beam deflection technique has been developed. This has enabled the accurate measurement of minute end-deflections of the suspension arm in 2-dimensions, to sub-nanometre resolution above noise. The design process of the suspension arm has led into the development of novel piezoelectric-actuated arms. In the work involving lead zirconate titanate (PZT) thick films as actuators, work in this thesis shows that reinforcing the films with fibre improves the overall actuation characteristics of the thick films. This discovery benefits applications such as structural health monitoring. The final suspension arm design has been adopted because it is simple in design, easier to integrate within current hard disk drive environment and easier to fabricate in mass. Closed-loop control algorithms based on proportional, integral and derivative (PID) controller techniques have been developed and implemented to demonstrate high bandwidths that have been achieved. The suspension arm developed presents an important solution in head-positioning technology in that it offers much higher bandwidths for data tracking and flying height control; both very essential in achieving even higher data storage densities on magnetic disks at much reduced head flying heights, compared to those in existing hard disk drives.