Owing to the continued increase in kilowatt capacity of new power stations being built today, proper sizing and selection of mechanical equipment has a vital effect on dollar savings, both for operation and maintenance costs as well as the initial cost of unit installation. In today's steam-electric plants, the power consumption of the motor-driven boiler feed pumps has been rising along with the increase of operating pressures and capacities. Power savings thus becomes a more significant factor than ever in selection of boiler feed pumping arrangement. Therefore, use of a more economical and justifiable boiler feed pumping arrangement with constant speed drive or variable speed drive through hydraulic couplings would vastly improve power plant economy and operation. This study compares the costs and operating characteristics of two constant-speed boiler feed pumps operating in parallel, against those of one constant-speed pump operating in parallel with one variable speed pump which is driven through hydraulic coupling (all pumps are of half-size capacity, motor-driven). This cost comparison shows that the former pumping arrangement is more economical than the latter at the unit base load. / Master of Science

TRANSIMS is a disaggregate, behavioral, regional transportation planning package developed by Los Alamos National Laboratory (LANL) under funding from US DOT, EPA, and Department of Energy. It is an integrated system of travel forecasting models designed to give transportation planners accurate, complete information on traffic impacts, congestion, and pollution by simulating on a second-by-second basis the movements of every person and every vehicle through the transportation network of a large metropolitan area. This regional microsimulation approach provides a better assessment of the performance of a large network than the current link performance functions utilized in the current planning procedures. On the other hand, their microsimulation approach on a regional scale requires a lot of data that may not be readily available, and utilize a low fidelity microsimulation in order to make it operational. Some agencies may be interested in performing a more detailed investigation of traffic patterns within a sub area, such as the downtown area. The author implemented a subarea focusing methodology within TRANSIMS and also developed an interface that allows the investigator to use a high-fidelity, small-size network efficient traffic operational software package — CORSIM to perform sub area traffic operational analysis with demand and network extracted from applications of TRANSIMS. This methodology will allow TRANSIMS to take advantage of higher fidelity models for sub-network analysis and allow CORSIM to use planning inputs such as individual 24 hour travel activities and trip chains. An evacuation model is also built and applied to Virginia Tech main campus, Blacksburg, VA to evaluate this sub area focusing methodology. / Master of Science

No / Optimal design (vapour load, V and number of stages, N) and operation (reflux ratio, R and batch time, tb) of batch distillation have received significant attention in recent years. In these studies, it has been suggested that V should be set at some upper limit (thought to be optimum) and the optimisation task should be focused on finding the optimum values of N, R and tb, which would minimise the capital investment while maximising an economic objective function usually the profit (P). The major drawback of such optimisation strategy is that there is no constraint on the amount of product (on specification) being produced (NB = no. of batches in a given time) and the overall profit can only be maximised by producing unlimited amount of products. Unplanned and unlimited production of products are not sustainable and may lead to significant losses in the case of large inventory requirements of any excess products produced. In this work, for the first time, the optimal design and operation task for batch distillation is considered with due regards to the market demands (small to large number of batches) of the products being produced. An optimisation problem formulation is presented for the task which is different than those used in the past under unlimited product demand scenario. Simulated Annealing type algorithm is used for the solution of the optimisation problem. With several examples, it will be shown that fixing V a priori (say V < Vopt) will not allow production of NB batches of products with any combination of (N, R, tb) in a given production time. Also it will be shown that with V fixed at say V > Vopt, P will always be <Pmax for any combination of (N, R, tb). The comparisons between the results with and without fixing of V a priori show very clear improvement in the annual profit.

No / This paper assesses the relationships between public policy and the development of industrial clusters. A conceptual model of the relationship between public policies and the development of industrial clusters is developed and tested using data from 43 European industrial clusters. The results indicate that most government policies have no significant impact on the growth of industrial clusters or for the development of co-operation within industrial clusters. There is limited evidence that packages of government policies that are specifically geared towards improving the local asset base are effective in overcoming obstacles to growth of industrial clusters. However, when age is used as a control variable the weak relationship between policy packages and growth of industrial clusters disappear. The results indicate that individual and packages of public policies are not strongly connected to either high levels of co-operation, or high growth in industrial clusters. Moreover, no clear evidence was found that high levels of co-operation were associated with growth in industrial districts. In the light of the failure to find clear-cut associations between public policies and the development of industrial clusters the paper outlines a research agenda to help to increase our understanding of these issues.

Switched reluctance motors (SRMs) are becoming popular in motor drive applications due to their simple construction, fault tolerance, and cost-effectiveness, making them well-suited for electric vehicles. However, SRMs face operational challenges at high speeds, where controller and position feedback delays may hinder smooth operation and efficiency. These challenges might limit the adoption of SRM in high-performance applications. This thesis addresses high-speed SRM control issues, focusing on delay compensation in both motoring and generating modes. Gain-scheduling PWM controller improvements and delay compensation strategies are presented to reduce the impact of position and switching delays at high-speed operation. Additionally, a four-quadrant SRM controller is proposed to enable smooth operation mode transitions and improved regenerative braking capability. A dedicated experimental setup with a three-phase 12/8 SRM connected to an electric dynamometer machine is built to validate the proposed techniques and demonstrate the improvements in the phase excitation accuracy and balance in phase currents at high speeds. The experimental results support the potential of these control methods to enhance SRM performance in high-speed applications, providing valuable insights for further improvement in electric vehicle drive train applications. / Thesis / Master of Applied Science (MASc)

Water reservoirs are used to regulate river discharge for a variety of reasons, such as flood mitigation, water availability for irrigation, municipal consumption and power production purposes. Recent efforts to increase the amount of renewable power production have seen an increase in intermittent climate-variable power production due to wind and solar power production. The additional variable energy production has increased the need for regulating the capacity of the electrical system, to which hydropower production is a significant contributor. The hydraulic impact on the time lags of flows between production stations have often largely been ignored in optimization planning models in favor of computational efficiency and simplicity. In this thesis, the hydrodynamics in the stream network connecting managed reservoirs were described using the kinematic-diffusive wave (KD) equation, which was implemented in optimization schemes to illustrate the effects of wave diffusion in flow stretches on the resulting production schedule. The effect of wave diffusion within a watershed on the variance of the discharge hydrograph within a river network was also analyzed using a spectral approach, illustrating that wave diffusion increases the variance of the hydrograph while the regulation of reservoirs generally increases the variance of the hydrograph over primarily short periods. Although stream hydrodynamics can increase the potential regulation capacity, the total capacity for power regulation in the Swedish reservoir system also depends significantly on the variability in climatic variables. Alternative formulations of the environmental objectives, which are often imposed as hard constraints on discharge, were further examined. The trade-off between the objectives of hydropower production and improvement of water quality in downstream areas was examined to potentially improve the ecological and aquatic environments and the regulation capacity of the network of reservoirs. / <p>QC 20170210</p>

Im Rahmen einer vergleichenden retrospektiven Analyse wurden die präoperativen und intraoperativen Einflussfaktoren auf den frühen und mittelfristigen postoperativen Verlauf nach Fontan-Operation untersucht und die Ergebnisse der totalen cavopulmonale Anastomose mit einem intraatrialen lateralen Tunnel (LTFO, n = 25) und mit einem extrakardialen Kunststoff-Konduit (ECFO, n = 25) gegenüber gestellt. Postoperativ wurde nach ECFO ein komplikationsärmerer früher Verlauf mit kürzerer maschineller Beatmung und signifikant geringerer Inzidenz für frühe und mittelfristige Arrhythmien als nach LTFO beobachtet. Im frühen postoperativen Verlauf waren die schnellste Extubation und Entlassung bei den ECFO-Patienten möglich, bei denen keine Kardioplegie verwendet wurde. Unabhängige Risikofaktoren nach multivariater Analyse waren die Dauer der Kardioplegie in Bezug zu den unmittelbaren postoperativen Komplikationen, eine LTFO - sowohl für Tachy- als auch für Bradyarrhythmien - und die Inzision in die cavoatriale Verbindung bei LTFO in Bezug zu Bradyarrhythmien mit der Notwendigkeit einer Schrittmacherimplantation. Durch Vermeidung von Kardioplegie und chirurgischer Schaffung eines lateralen Tunnels sowie Verkürzung des kardiopulmonalen Bypasses bei ECFO werden vor allem die postoperativen Arrhythmien reduziert und es ist wahrscheinlich möglich, den postoperativen Verlauf bei Patienten mit einem durch eine langwierige Zyanose und durch Volumenbelastung vorbeschädigten singulären Ventrikel zu verbessern. Eine prospektive langfristige Vergleichsstudie mit einer größeren Patientenzahl ist notwendig, um die Frage zu beantworten, ob eine signifikante Minderung der spätpostoperativen Komplikationen und eine Verbesserung der Lebenserwartung der Patienten mit univentrikulärer Physiologie durch eine korrekt geplante und optimal durchgeführte extrakardiale Modifikationen der Fontan-Operation erreicht werden kann. / The preoperative and intraoperative risk factors for early and mid-term postoperative course after Fontan operation were analyzed and results after total cavopulmonary connection with lateral intraatrial tunnel (LTFO, n = 25) and with extracardiac conduit (ECFO, n = 25) were compared retrospectively. The early postoperative course after ECFO was better with shorter duration of mechanical ventilation. Lower incidence of arrhythmias was observed after ECFO compared to LTFO both early postoperatively and during mid-term follow-up. Patients after ECFO, in whom cardioplegia was not used intraoperatively, had the shortest duration of mechanical ventilation and of the hospital stay. Multivariate analysis revealed duration of cardioplegia as an independent risk factor for early postoperative complications, LTFO as a risk factor for tachyarrhythmias and incision into the cavoatrial junction during LTFO as a risk factor for the bradyarrhythmias requiring pacemaker implantation. With the avoidance of cardioplegia and intracardiac surgery and shorter cardiopulmonary bypass times during ECFO, postoperative arrhythmias could be reduced. Further, the early postoperative course in patients with univentricular physiology who have had cyanosis and ventricular volume overload for a long time seems to be better after extracardiac modification of Fontan operation. To investigate whether late complications are reduced by optimal extracardiac Fontan operation and whether life expectancy in patients with single ventricle is improved, long-term prospective comparative follow-up studies are needed.

This thesis aims to explore the disconnect between calls for safe zones as a tool of humanitarian intervention, and the dark history of safe zone failure. This thesis begins with a brief discussion of current calls for safe zones in Syria, and how a proper theoretical framework and historical understanding are needed to discuss whether or not safe zones can be successfully implemented in Syria. The following literature review discusses not only prominent academic arguments and the history of humanitarian intervention, but it suggests a framework for deconstructing case studies. This framework looks first at the interests of an intervening actor. The level of interest of that actor directly informs its willingness to overcome the challenges of safe zone implementation. The challenges of safe zone implementation are both practical and existential. If an actor’s interest in a given crisis is not great enough to make it willing to overcome these practical and existential challenges, or the actor is willing to overcome them but lacks the ability to do so, the safe zone will fail. In most cases of failed safe zones, moral hazard plays a role. Moral hazard can be evident in either the intervening actor’s decisions or the decisions of the international community to support or not support the intervention. This thesis then deconstructs three historical cases of safe zones with this method: Srebrenica in Bosnia, Operation Provide Comfort in Iraqi Kurdistan, and Operation Turquoise in Rwanda. Following these three case studies, this paper discusses safe zones in Syria with the help of this method and the broad historical understanding of safe zones established through the case studies. This thesis concludes with a discussion of how the analysis and available historical cases show that safe zones are dangerous tools of humanitarian intervention and should not be undertaken without adequate levels of interest and willingness to address challenges.

A microgrid is a subnetwork of power system that consists of a group of distributed energy sources and loads. It is designed to integrate distributed generation, loads, energy storage devices, converters, and monitoring and protection devices. Generally, a successful microgrid could run both in island mode (off-grid) and in grid-connected mode (on-grid), being able to convert between two modes at any time. With continuous development of the power system, distributed renewable generation unit accounts for an increasing proportion, since microgrid could effectively connect these generation units to the main grid, thereby improving the energy efficiency and the energy structure. Microgrid is increasingly playing an important role in the power system. This thesis focuses on reducing the cost of microgrids through economic operation, including both static and dynamic economic operations. Three cases are tested based on these two methods. Also, each case will include four situations including one without ESS and three situations with 2MWh ESS, 3MWh ESS, 4MWh ESS, respectively.

<p>Operation Atalanta är en EU gemensam marin operation utanför Somalias kust som syftar till att skydda Word Food Program sjötransporter från piratattacker i området. Försvarsmaktens styrkebidrag till operationen består i huvudsak av Internationella Korvettstyrkan (IKS) som innehåller korvetterna HMS Stockholm, HMS Malmö och stödfartyget HMS Trossö. Förbandet transporterades till insatsområdet med strategisk sjötransport. Att transportera svenska örlogs-fartyg på detta sätt är tämligen nytt inom marinen. Strategiska sjötransporter kräver framförhållning då sjötransportresurserna i vissa fall kan vara svårt att få tillgängliga på den tid som önskas. Därför har denna uppsats inriktats på transportplaneringen av operation Atalanta.</p><p>Uppsatsen syftar till att undersöka och jämföra teori med praktik där kvalitativ textanalys har ställts mot kvalitativa intervjuer. Genom en undersökning av transportplaneringen under operation Atalanta som jämförts med <em>Handbok Försvarsmaktens Transporter Grunder (H FM Tp Grunder) </em>har skillnader identifieras. Dessa skillnader har senare värderas mot hur transportplanerings- processen följdes.</p><p>Processen har i denna uppsats begränsats till att undersöka de tre första delprocesserna, som författaren valt kalla för faser: <em>inhämtning, bedömning och upphandling.</em> Faserna används genomgående genom empirin där underaktiviteterna i respektive fas presenteras. Faktorer att beakta under planeringen är <em>kostnadseffektivitet, tid</em> och <em>kvalitet</em>. Dessa faktorers inverkan undersöks närmare i respektive fas.</p><p>Fallstudien visar att transportplaneringsprocessen inte följts enligt <em>H</em> <em>FM Tp Grunder</em>. Den främsta orsaken är tidsbrist som forcerat planeringen. Erfarenhet hos dem som varit involverade i planeringen har dock medgett att kontrollerade avsteg från processen kunnat göras.</p> / <p>Operation Atalanta is an EU combined maritime operation outside Somalia’s coasts. The main objective of the operation is to protect World Food Program sea transports in the area from pirate attacks. The Swedish Armed Forces has contributed with a maritime task force containing two corvettes and a supply ship. The ships were transported by a strategic sealift to area of operations. The knowledge of transporting Swedish naval vessels this way is limited due to lack of experience. Sea transports of this kind need to be planned with a long-term view due to the competitive situation on the sea transport market and the limitation of resources. </p><p>This essay is therefore focused on the planning process of the described transport where an investigation of theory and practice is done. The theory comes from an internal handbook which describes The Swedish Armed Forces planning process for military transports. This planning process will be compared to the case study, operation Atalanta in order to sort out differences. These differences will show how well the planning process was followed in this particular case.  </p><p>The author has limited the planning process to involve three different stages in the planning process, these are: <em>Information gathering, Assessment </em>and<em> Procurement</em> and hereafter called phases. The stages will in time be set from the political directive to a sea transport has been procured. Different aspects are to be considered during the planning process. These are cost efficiency, time and quality. These aspects will be examined in each phase in order to investigate how they have affected the planning process.    </p><p>The case study shows that the planning process has not been followed according to what the handbook describes. The main reason is the lack of time. The time has been a crucial factor which has driven the transport planning to make deviations. However this deviation has been done with good knowledge about the planning process thru experience.</p>