The deterioration of prestressed concrete structures due to corrosion is a costly problem. This problem is accelerated in cold weather climates where de-icing salts are used. These salts accelerate the corrosion of the steel tendons greatly reducing the service life of the structures and leading to constant costly repairs. Recent research has shown composite materials such as Fibre Reinforced Polymers (FRP) to be suitable alternatives to steel, providing similar strength without being susceptible to electrochemical corrosion. Carbon FRP in particular has great promise for prestressed applications, showing resistance to corrosion in environments that might be encountered in concrete and experiencing less relaxation than steel. This thesis outlines the testing and implementation of a post-tensioned system that uses CFRP tendons to replace corroded, unbonded post-tensioned steel tendons. This system was then implemented in a parking garage in downtown Toronto. To the author’s knowledge, this is the first example of an unbonded, post-tensioned tendon replacement using FRP tendons. The system used split wedge anchors designed specifically for CFRP tendons at the University of Waterloo. The dead end was anchored by directly bonding the tendon to the concrete slab. Overall, the system was shown to work and provide a durable solution for unbonded post-tensioning systems. The CFRP tendon was successfully inserted in the opening left by the removal of the corroded tendon and stressed. It was found that the current anchorage configuration experienced large load losses of up to 60 % during the transfer. Changing the orientation of the anchor was found to reduce the load lost to a range of 1 % to 9 %. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-04-09 15:30:59.865

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<p>Dye-sensitised solar cells (DSC) have attracted much attention during the last few years due to their high efficiencies and their potentially low production costs. The technology is based on a thin layer of nano sized, high band gap (3.2 eV) TiO2 film. A Ru containing dye (from hereon called the Ru dye) is chemisorbed onto the TiO2 film. This combination acts as the working electrode. The counter electrode consists of a platinum layer which is the catalyst for the regeneration of the Iodine/Iodide electrolyte. The work that is presented here is focused on the results that were obtained during studies of the performance of the DSC under certain reverse bias conditions. When one cell in the series connection in a module is shaded, the current will pass this cell in reverse bias. In such a case the shaded cell will be subjected to a voltage in the reverse direction coming from the other lit cells in the module. This reverse voltage could permanently modify or damage the cell if it is not properly protected. Although the work is focussed on the chemical stability of the dye, various techniques were employed to determine the physical changes in the cell. It was found that a cell that was subjected to a reverse bias of 2 V for 500 min showed a 58% recovery and a cell that was subjected to 4.5 V reverse bias was irreversibly damaged. The UV-vis spectra showed a blue shift (higher energy), the Raman showed no peak at 1713 cm-1 (which indicates the absence of free carboxylate groups) and the FT-IR showed the disappearance of the NC-S absorption band at 2100 cm-1. The combined conclusion is that the &ndash / NCS ligand has been depleted and replaced with I3- ions. When measuring the impedance, the Nyquist plots showed an increase in the charge transfer resistance at the counter electrode when subjected to a reverse bias potential of 2 V. This is confirmed by the Bode plots. This indicates a partial oxidation of the Pt catalyst on the counter electrode. It can therefore be stated with confidence that the changes in the cell after being subjected to a reverse bias potential of 2 V for 500 min are changes on the -NCS bonds on the Ru dye as well as the Pt in the counter electrode.</p>

ABSTRACT Voltage instability has become a major concern in power systems. Many blackouts have been reported where the main cause is voltage instability. This thesis deals with two specific areas of voltage stability in on-line power system security assessments: small-disturbance (long-term) and large-disturbance (short-term) voltage stability assessment. For each category of voltage stability, both voltage stability analysis and controls are studied. The overall objective is to use the learning capabilities of computational intelligence technology to build up the comprehensive on-line power system security assessment and control strategy as well as to enhance the speed and efficiency of the process with minimal human intervention. The voltage stability problems are quantified by voltage stability indices which measure the system for the closeness of current operating point to voltage instability. The indices are different for small-disturbance and large-disturbance voltage stability assessment. Conventional approaches, such as continuation power flow or time-domain simulation, can be used to obtain voltage stability indices. However, these conventional approaches are limited by computation time that is significant for on-line computation. The Artificial Neural Network (ANN) approach is proposed to compute voltage stability indices as an alternative to the conventional approaches. The proposed ANN algorithm is used to estimate voltage stability indices under both normal and contingency operating conditions. The input variables of ANN are obtained in real-time by an on-line measurement system, i.e. Phasor Measurement Units (PMU). This thesis will propose a suboptimal approach for seeking the best locations for PMUs from a voltage stability viewpoint. The ANN-based method is not limited to compute voltage stability indices but can also be extended to determine suitable control actions. Load shedding is one of the most effective approaches against short-term voltage instability under large disturbances. The basic requirement of load shedding for recovering voltage stability is to seek an optimal solution for when, where, and how much load should be shed. Two simulation based approaches, particle swarm optimization (PSO) algorithm and sensitivity based algorithm, are proposed for load shedding to prevent voltage instability or collapse. Both approaches are based on time-domain simulation.

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With increase of a web application popularity there was a necessity of simplification of their creation. In this paper ways of creation electronic data processing and opportunities of their simplification are investigated. Models of web application and tools for their creation are considered in the paper. Being based on this analysis the model which more all would approach for creation of the fast interface of data processing is offered. It is based on the user interface architecture separated from logic of activity. The offered model is realized by system of programs PHPForm on a platform Eclipse, the comparative analysis of the created and existing products is executed.

Impression management (IM) handlar om enmedveten eller omedveten process att styra intrycken av sig själv som ges tillomgivningen i syfte att imponera och söka erkännande. Tidigare forskning har istor utsträckning berört anställningsrekommendation utifrån intervjuer och demest framgångsrika resultaten har visat sig vara självförbättrande IM taktik.Studiens syfte vara att undersöka hur självförbättrande IM taktik i personligtbrev, två kvalitéer av meriter, påverkar ett beslut omanställningsrekommendation, samt undersöka hur en uppsättning personliga egenskaperrelaterar till självförbättrande IM taktik. Deltagarna var studenter, 57kvinnor och 32 män. Studien var experimentell 2 x 2 x 2 mellangruppsdesign. Deviktigaste fynden var att, högre kvalité av meriter innebar högre skattning avanställningsrekommendation samt att högre skattning av egenskaper vidsjälvförbättrande IM taktik skattats. Meriters kvalité visades viktig,egenskaper visade samband med IM dock satte IM trovärdighet på spel.Könsskillnader påträffades även och vidare forskning förslås göras mellankönen.

This thesis explores the possibility that graphic design can have a positive impact on the morale of a male undergoing chemotherapy for testicular cancer. The paper explains the concept of “morale,” why it is vital for patients at a cancer infusion center, and subsequently how graphic design can boost morale. The supporting research fostered a socially-responsible design solution—a mobile application that intertwines design, health, and technology. The application is geared to the patient experience. As such, it can reduce anxiety by providing a distraction in the form of entertainment (as well as providing tools and an anonymous connection for the individual patient to a similar patient population). Furthermore, the application is also designed for research purposes by establishing a framework for collecting measurable data. In turn, this data can be used to enhance the chemotherapy experience—thus contributing to a positive impact on the morale of the cancer patient.

Guía de practicas para laboratorio de Química para carreras de ingeniería

In times of demand shocks, when quantitative forecasting based on historical time series becomes obsolete, the only information about future demand is "advance demand information", i.e. interpreting early customer bookings as an indicator of not yet known demand. This paper deals with a forecasting method which selects the optimal forecasting model type and the level of integration of advance demand information, depending on the patterns of the particular time series. This constitutes the applicability of the procedure within an industrial application where a large number of time series is automatically forecasted in a flexible and data-driven way. The architecture of such a planning system is explained and using real-world data from a make-to-order industry it is shown that the system is flexible enough to cover different demand patterns and is well-suited to forecast demand shocks. (authors' abstract)