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Německo jako "rozpolcený aktér" na příkladu projektu Nord Stream / Germany as "dividual actor" on the case of Nord Stream projectBundová, Klára January 2019 (has links)
This Master thesis examines the German foreign energy policy with focus on the German- Russian energy cooperation and the pipeline projects Nord Stream I and II. It seeks to analyze inconsistencies or even contradictions in the German foreign policy regarding the Nord Stream project. Both strategic and business interests on one hand and value based policy on the other are present and observable. Therefore this paper works with Jakub Eberle's concept of Germany as "dividual actor" which enables us to work with the already mentioned inconsistencies. Furthermore, this approach allows us to observe "geo-economic power" aspects in German actions (favoring strategic and mostly business interests) as well as "civilian power" aspects (value based policy) and eventually to see Germany as an actor in the international relations in its complexity. This thesis therefore aims to contribute to a broader debate about German actorness and its roles in international system. Moreover, German domestic energy policy will be analyzed in order to provide us with the basis for German foreign energy policy. The main focus of this paper is on natural gas and its importance in the German energy mix as well as on German dependence on its imports. The import routes and primarily the pipeline routes Nord Stream I and II are...
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EVALUATIONS ON ENZYMATIC EPOXIDATION, EFFICIENCY AND DECAYElena A Robles Molina (9751112) 14 December 2020 (has links)
<p>The potential use of enzymes in
industrial synthesis of epoxidized soybean oil has been limited through the
high cost of the enzyme catalyst, in this work we evaluate the effectiveness of chemo
enzymatic epoxidation of high oleic soybean oil (HOSBO) using lipase B from <i>Candida
antarctica </i>(CALB) on immobilization support Immobead 150 and H<sub>2</sub>O<sub>2
</sub>in a solvent-free system. Additionally, we evaluated the production decay
rates for hydrolytic activity and epoxide product formation over consecutive
batches to determine half-life of the enzyme catalyst. </p>
<p> Batch epoxidation of HOSBO using CALB on 4wt%
loading shows yields higher than 90% after 12 hrs. of reaction, and with a correlation
to the consumption of double bonds suggesting that the reaction is selective
and limiting side product reactions. Non-selective hydrolysis of oil was not
found beyond the initial hydrolysis degree of raw HOSBO. Evaluations of decay
given by epoxide product formation and released free fatty acids shows a half-life
of the enzyme catalyst on these activities is of 22 ad 25 hrs. respectively. Finally,
we evaluated the physical parameters influencing this decay, and found that H<sub>2</sub>O<sub>2</sub>
presence is the most important parameter of enzyme inactivation with no
significant effect from its slowed addition. We propose a new reactor
configuration for the analysis of the specific steps on epoxide formation
through peracid intermediates. </p>
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Energiemanagement Strategien für elektrische Energiebordnetze in KraftfahrzeugenBüchner, Stefan 10 July 2008 (has links)
Die elektrische Energieform gewinnt im Kraftfahrzeug wegen ihrer Nutzungsvielfalt und sehr guten Steuerbarkeit für die Realisierung neuartiger Funktionen zunehmend an Bedeutung. Voraussetzung für ihren Einsatz ist eine zuverlässige und effiziente Bereitstellung durch das Kfz-Energiebordnetz. Dafür ist ein intelligentes Energiemanagement erforderlich, welches mit geeigneten Strategien die Leistungsflüsse im Energiesystem koordiniert. In dieser Arbeit werden die beiden Entwurfsziele der Zuverlässigkeit und der Effizienz bei der Entwicklung von elektrischen Energiemanagement-Strategien systematisch betrachtet. Es erfolgt eine Beschreibung und Zuordnung der einzelnen Ziele und Maßnahmen anhand der Energieflüsse und Wirkungsketten. Ein Schwerpunkt bildet dabei die Beherrschung von Lastwechseln im Bordnetz. Für Aussagen hinsichtlich einer effizienten Erzeugung elektrischer Energie erfolgt eine Untersuchung der Energiewandlungskette anhand analytischer Methoden und mit Hilfe einer simulationsgestützten Optimierung. Ein weiterer Fokus der Arbeit liegt in der Betrachtung zur Anwendung ökonomischer Modelle für eine Energiekoordination. Es werden die theoretischen Grundlagen der Mikroökonomie zusammengestellt und mögliche Funktionsstrukturen eines einseitigen und zweiseitigen Allokationsmechanismus verglichen und bewertet. Abschließend zeigen experimentelle Untersuchungen an einem Bordnetzprüfstand zum Lastwechselverhalten und die Integration eines Energiemanagement-Systems den praktischen Bezug zum realen System.
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DIGITAL HYDRAULICS IN ELECTRIC HYBRID VEHICLES TO IMPROVE EFFICIENCY AND BATTERY USEJorge Leon Quiroga (9192758) 31 July 2020 (has links)
The transportation
sector consumes around 70% of all petroleum in the US. In recent years, there
have been improvements in the efficiency of the vehicles, and hybrid techniques
that have been used to improve efficiency for conventional combustion vehicles.
Hydraulic systems have been used as an alternative to conventional electric
regenerative systems with good results. It has been proven that hydraulic
systems can improve energy consumption in conventional combustion vehicles and
in refuse collection vehicles. The control strategy has a large impact on the
performance of the system and studies have shown the control strategy selection
should be optimized and selected based on application. The performance of a
hydraulic accumulator was compared with the performance of a set of
ultracapacitors with the same energy storage capacity. The energy efficiency
for the ultracapacitor was around 79% and the energy efficiency of the
hydraulic accumulator was 87.7%. The power/mass ratio in the set of
ultracapacitors was 2.21 kW/kg and 2.69 kW/kg in the hydraulic accumulator. The
cost/power ratio is 217 US$/kW in the ultracapacitors and 75 US$/kW in the
hydraulic accumulator. Based on these results, the hydraulic accumulator was
selected as the energy storage device for the system. A testbench was designed,
modeled, implemented to test the energy storage system in different conditions
of operation. The experimental results of the testbench show how system can be
actively controlled for different operating conditions. The operating
conditions in the system can be adjusted by changing the number of rheostats
connected to the electric generator. Different variables in the system were
measured such as the angular shaft speed in the hydraulic pump, the torque and
speed in the hydraulic motor, the pressure in the system, the flow rate, and
the current and voltage in the electric generator. The control algorithm was
successfully implemented, the results for the pressure in the system and the
angular speed in the electric generator show how the control system can follow
a desired reference value. Two different controllers were implemented: one
controller for the pressure in the system, and one controller for the speed.
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Investigation of energy management topologies for forming presses with electro hydrostatic drivetrainsReidl, Tim, Weber, Jürgen, Ihlenfeldt, Steffen 25 June 2020 (has links)
Recent Power On Demand approaches, realized by using speed and/or displacement variable pump units, led to a significant increase of energy efficiency on hydraulic forming presses. In this paper we follow up on this development by laying the focus on the energy management and storage design of such machinery. With a derived fluidtronical model, we compare five different topologies that supply and manage the power flow for a forming press with die cushion. Our evaluation criteria are: energy consumption, minimization of the infeed power, and qualitative costs. For a representative forming cycle, the losses occurring on each of the drivetrain components and the power electronics accessory are derived in detail. We expect that this research will lead to deeper investigation of more intelligent energy management systems that use multiple storages in an optimal way and further learn and adapt during operation.
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Distributed Optimization Algorithms for Inter-regional Coordination of Electricity MarketsVeronica R Bosquezfoti (10653461) 07 May 2021 (has links)
<p>In the US, seven regional transmission organizations (RTOs)
operate wholesale electricity markets within three largely independent
transmission systems, the largest of which includes five RTO regions and many
vertically integrated utilities.</p>
<p>RTOs operate a day-ahead and a real-time market. In the
day-ahead market, generation and demand-side resources are optimally scheduled
based on bids and offers for the next day.
Those schedules are adjusted according to actual operating conditions in
the real-time market. Both markets
involve a unit commitment calculation, a mixed integer program that determines
which generators will be online, and an economic dispatch calculation, an
optimization determines the output of each online generator for every interval
and calculates locational marginal prices (LMPs).</p>
<p>The use of LMPs for the management of congestion in RTO transmission
systems has brought efficiency and transparency to the operation of electric
power systems and provides price signals that highlight the need for investment
in transmission and generation. Through
this work, we aim to extend these efficiency and transparency gains to the
coordination across RTOs. Existing market-based
inter-regional coordination schemes are limited to incremental changes in
real-time markets. </p>
<p>We propose a multi-regional unit-commitment that enables
coordination in the day-ahead timeframe by applying a distributed approach to approximate
a system-wide optimal commitment and dispatch while allowing each region to
largely maintain their own rules, model only internal transmission up to the
boundary, and keep sensitive financial information confidential. A heuristic algorithm based on an extension
of the alternating directions method of multipliers (ADMM) for the mixed
integer program is applied to the unit commitment. </p>
The proposed coordinated solution was simulated and
compared to the ideal single-market scenario and to a representation of the
current uncoordinated solution, achieving at least 58% of the maximum potential
savings, which, in terms of the annual cost of electric generation in the US, could
add up to nearly $7 billion per year. In
addition to the coordinated day-ahead solution, we develop a distributed
solution for financial transmission rights (FTR) auctions with minimal
information sharing across RTOs that constitutes the
first known work to provide a viable option for market participants to seamlessly hedge price
variability exposure on cross-border transactions.
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Development of a Reduced Computational Model to Replicate Inlet Distortion in an APU-Style Inlet of a Centrifugal CompressorEvan Henry Bond (12455190) 25 April 2022 (has links)
<p>The purpose of this research was to determine what components of a complex centrifugal compression system inlet needed to be modelled to accurately predict the swirl and total pressure distortions at the compressor face. Two computational models were developed. A full-fidelity case where all the inlet geometry was modelled and a reduced model where a small portion of the inlet was considered. Both the numerical cases were compared with experimental data from a research compressor rig developed by Honeywell Aerospace. The test apparatus was designed with a modular inlet system to develop swirl distortion patterns. The modular inlet system utilized transposable baffles within the radial-to-axial section of the inlet and blockage plates of varying sizes and geometries at the inlet to this section. Discerning the dominant inlet component that dictates distortion behavior at the compressor face would allow the reduced modelling of inlet components for compression systems and would allow coupling with more tortuous systems. Furthermore, it would reduce the design iteration and simulation time of the inlet systems. Several investigations utilizing a reduced model only considering a radial-to-axial inlet are available in literature, but no comprehensive justification has been presented as to the impact this has on the distortion behavior. Experimental surveys of flow conditions just upstream of the inducer of the centrifugal compressor were conducted at several operating conditions. The highest and lowest mass flow rates of these operating points were simulated using ANSYS CFX 2020R1 for both the computational models. Multiple inlet configurations were simulated to test the robustness of the reduced model in comparison to the full fidelity. The numerical simulations highlighted shortcomings of the instrumentation used to characterize the experimental flow field at the inducer, particularly with respect to total pressure distortion. Furthermore, transient pressure data were measured in experiment and indicated unsteady fluctuations in the inlet that would not be captured by steady computational fluid dynamic simulations. These data matched locations of disagreement with swirl distortion behavior at high mass flow rates. This suggested that transient vortex movement occured at the aerodynamic interface plane in certain configurations. The total pressure distortion metrics between the two models were remarkably comparable. Furthermore, the simplified model accurately predicted the mixing losses associated with the blockage plates at the inlet to the radial-to-axial inlet using a simple inlet extension. Swirl 18 distortion was dictated by the radial-to-axial inlet. The reduced model data trends were comparable with experiment for both the baffle and blocker plate configurations. The swirl intensities for all configurations were comparable between the two models. The reduced model swirl directivity trends matched those of experiment. The most notable deviations between the full-fidelity model and the reduced model were observed with swirl directivity numerics. </p>
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Rooftop PV Impacts on Fossil Fuel Electricity Generation and CO2 Emissions in the Pacific NorthwestWeiland, Daniel Albert 27 August 2013 (has links)
This thesis estimates the impacts of rooftop photovoltaic (PV) capacity on electricity generation and CO2 emissions in America's Pacific Northwest. The region's demand for electricity is increasing at the same time that it is attempting to reduce its greenhouse gas emissions. The electricity generated by rooftop PV capacity is expected to displace electricity from fossil fueled electricity generators and reduce CO2 emissions, but when and how much? And how can this region maximize and focus the impacts of additional rooftop PV capacity on CO2 emissions? To answer these questions, an hourly urban rooftop PV generation profile for 2009 was created from estimates of regional rooftop PV capacity and solar resource data. That profile was compared with the region's hourly fossil fuel generation profile for 2009 to determine how much urban rooftop PV generation reduced annual fossil fuel electricity generation and CO2 emissions. Those reductions were then projected for a range of additional multiples of rooftop PV capacity. The conclusions indicate that additional rooftop PV capacity in the region primarily displaces electricity from natural gas generators, and shows that the timing of rooftop PV generation corresponds with the use of fossil fuel generators. Each additional Wp/ capita of rooftop PV capacity reduces CO2 emissions by 9,600 to 7,300 tons/ year. The final discussion proposes some methods to maximize and focus rooftop PV impacts on CO2 emissions, and also suggests some questions for further research.
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Design, Fabrication, and Testing of an EMR Based Orbital Debris Impact Testing PlatformManiglia, Jeffrey J, Jr. 01 June 2013 (has links) (PDF)
This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic railgun and projectile system capable of firing an approximate 1g aluminum projectile to speeds exceeding 2 km/s. A novel three part projectile is proposed to mitigate rail and projectile degradation. Projectile and sabot system kinematic equations are derived and the projectile is designed and tested along with Mk. 2 barrel. A numerical electromechanical model is developed to predict the performance of the Mk. 2 system and projectile assembly, and predicts a final velocity for the fabricated system exceeding 3.5 km/s and an efficiency as high as 24%. Testing of the Mk. 2 system showed catastrophic failure of the projectile during initial acceleration, resulting in very short acceleration times and distance, low velocity projectiles, and low efficiencies. During further testing of various projectile configurations, the barrel structure failed due to a large internal arc. Future work for the Mk. 2 system is discussed, a revised external barrel structure suggested, and a solid, more conventional solid chevron projectile design suggested.
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Performance Enhancement and Characterization of an Electromagnetic RailgunGilles, Paul M 01 December 2019 (has links) (PDF)
Collision with orbital debris poses a serious threat to spacecraft and astronauts. Hypervelocity impacts resulting from collisions mean that objects with a mass less than 1g can cause mission-ending damage to spacecraft. A means of shielding spacecraft against collisions is necessary. A means of testing candidate shielding methods for their efficacy in mitigating hypervelocity impacts is therefore also necessary. Cal Poly’s Electromagnetic Railgun was designed with the goal of creating a laboratory system capable of simulating hypervelocity (≥ 3 km/s) impacts. Due to several factors, the system was not previously capable of high-velocity (≥ 1 km/s) tests. A deficient projectile design is revised, and a new design is tested. The new projectile design is demonstrated to enable far greater performance than the previous design, with a muzzle velocity ≥ 1 km/sbeing verified during testing, and an energy conversion efficiency of 2.7%. A method of improving contact and controlling wear at the projectile/rail interface using silver plating and conductive silver paste is validated. A mechanism explaining the problem of internal arcing within the railgun barrel is proposed, and design recommendations are made to eliminate arcing on the basis of the work done during testing. The primary structural members are found to be deficient for their application and a failure analysis of a failed member, loading analysis of the railgun barrel, and design of new structures is undertaken and presented.
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