Applying life cycle assessment to analyze the environmental sustainability of public transit modes for the City of Toronto

One challenge related to transit planning is selecting the appropriate mode: bus, light rail transit (LRT), regional express rail (RER), or subway. This project uses data from life cycle assessment to develop a tool to measure energy requirements for different modes of transit, on a per passenger-kilometer basis. For each of the four transit modes listed, a range of energy requirements associated with different vehicle models and manufacturers was developed. The tool demonstrated that there are distinct ranges where specific transit modes are the best choice. Diesel buses are the clear best choice from 7-51 passengers, LRTs make the most sense from 201-427 passengers, and subways are the best choice above 918 passengers. There are a number of other passenger loading ranges where more than one transit mode makes sense; in particular, LRT and RER represent very energy-efficient options for ridership ranging from 200 to 900 passengers. The tool developed in the thesis was used to analyze the Bloor-Danforth subway line in Toronto using estimated ridership for weekday morning peak hours. It was found that ridership across the line is for the most part actually insufficient to justify subways over LRTs or RER. This suggests that extensions to the existing Bloor-Danforth line should consider LRT options, which could service the passenger loads at the ends of the line with far greater energy efficiency. It was also clear that additional destinations along the entire transit line are necessary to increase the per passenger-kilometer energy efficiency, as the current pattern of commuting to downtown leaves much of the system underutilized. It is hoped that the tool developed in this thesis can be used as an additional resource in the transit mode decision-making process for many developing transportation systems, including the transit systems across the GTHA.

Characterization of High-Performance Organic Dyes for Dye-Sensitized Solar Cell: A DFT/TDDFT Study

Dye-sensitized solar cell (DSSC) is currently a promising technology that makes solar energy efficient and cost-effective to harness. In DSSC, metal free dyes, such indoline-containing D149 and D205, are proved to be potential alternatives for traditional metal organic dyes. In this work, a DFT/TDDFT characterization for D149 and D205 were carried out using different functionals, including B3LYP, MPW1K, CAM-B3LYP and PBE0. Three different conformers for D149 and four different conformers for D205 were identified and calculated in vacuum. The performance of different functionals on calculating the maximum absorbance of the dyes in vacuum and five common solvents (acetonitrile, chloroform, ethanol, methanol, and THF) were examined and compared to determine the suitable computational setting for predicting properties of these two dyes. Furthermore, deprotonated D149 and D205 in solvents were also considered, and the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were calculated, which elucidates the substitution effect on the rhodanine ring of D149 and D205 dyes on their efficiency. Finally, D149 and D205 molecules were confirmed to be firmly anchored on ZnO surface by periodic DFT calculations. These results would shed light on the design of new highly efficiency metal-free dyes.

Flash-Sintering and Characterization of La0.8Sr0.2Ga0.8Mg0.2O3-δ Electrolytes for Solid Oxide Fuel Cells

La_0.8Sr_0.2Ga_0.8Mg_0.2O_3-δ (LSGM), a promising electrolyte material for intermediate temperature solid oxide fuel cells, can be sintered to a fully dense state by a flash-sintering technique. In this work, LSGM is sintered by the current-limiting flash-sintering process at 690°C under an electric field of 100 V cm^-1, in comparison with up to 1400°C or even higher temperature in conventional furnace sintering. The resultant LSGM samples are investigated by scanning electron microscopy, X-ray diffraction, and electrochemical impedance spectroscopy. The SEM images exhibit well-densified microstructures while XRD results show that the perovskite structure after flash-sintering does not changed. EIS results show that the conductivity of LSGM sintered by the current-limiting flash-sintering process increases with sintering current density value. The conductivity of samples sintered at 120 mA mm^-2 reaches 0.049 σ cm^-1 at 800°C, which is approximate to the value of conventional sintered LSGM samples at 1400°C. Additionally, the flash-sintering process is interpreted by Joule heating theory. Therefore, the current-limiting flash-sintering technique is proved to be an energy-efficient and eligible approach for the densification of LSGM and other materials requiring high sintering temperature.

Novel ketone diet enhances physical and cognitive performance

Ketone bodies are the most energy-efficient fuel and yield more ATP per mole of substrate than pyruvate and increase the free energy released from ATP hydrolysis. Elevation of circulating ketones via high-fat, low-carbohydrate diets has been used for the treatment of drug-refractory epilepsy and for neurodegenerative diseases, such as Parkinson's disease. Ketones may also be beneficial for muscle and brain in times of stress, such as endurance exercise. The challenge has been to raise circulating ketone levels by using a palatable diet without altering lipid levels. We found that blood ketone levels can be increased and cholesterol and triglycerides decreased by feeding rats a novel ketone ester diet: chow that is supplemented with (R)-3-hydroxybutyl (R)-3-hydroxybutyrate as 30% of calories. For 5 d, rats on the ketone diet ran 32% further on a treadmill than did control rats that ate an isocaloric diet that was supplemented with either corn starch or palm oil (P < 0.05). Ketone-fed rats completed an 8-arm radial maze test 38% faster than did those on the other diets, making more correct decisions before making a mistake (P < 0.05). Isolated, perfused hearts from rats that were fed the ketone diet had greater free energy available from ATP hydrolysis during increased work than did hearts from rats on the other diets as shown by using [(31)P]-NMR spectroscopy. The novel ketone diet, therefore, improved physical performance and cognitive function in rats, and its energy-sparing properties suggest that it may help to treat a range of human conditions with metabolic abnormalities.

Untersuchungen Gewichtsreduktionspotentiale Gegengewichtsgabelstapler

Die Masse eines Gegengewichtstaplers beeinflusst den Energieverbrauch beim Fahren maßgeblich. Steigende Energiepreise und steigendes Umweltbewusstsein führen zu grünen Trends in Logistik. Durch Reduktion der Gesamtmasse eines Gabelstaplers können große Einsparungen erreicht werden. Eine Machbarkeitsstudie soll mithilfe der numerischen Simulationen zeigen, dass neuartige Fahrzeuge mit aktiven Systemen trotz geringerer Masse hinreichend hohe Standsicherheit aufweisen können. In diesem Beitrag sollen die ersten Ergebnisse dieses Forschungsvorhabens vorgestellt werden.

Resistive Embedded Heating for Homogeneous Curing of Composite Damage Repair

Thesis (Ph.D.)--University of Washington, 2016-08

Todo Brasileiro merece nível A : habitação multifamiliar para o programa minha casa minha vida energeticamente eficiente

This thesis describes the theoretical, methodological and programmatic proposal for a multifamily residential building located in the urban expansion area of Parnamirim/RN, inserted in the program Minha Casa Minha Vida and level of energy efficiency "A", as the RegulamentoTécnico de Qualidade (RTQ-R/INMETRO) for residential buildings. The development project initially consists of procedures as the study of theoretical, architectural programming and cases studies. With the delimitation of a field solution, situated between the reference and the context, proposals are studied to determine the solution and architectural detailing of the proposal. The architectural program was built based on the method of Problem Seeking (Peña and Parshall, 2001) and research has highlighted aspects of reducing the environmental impact and of the program Minha Casa Minha Vida , among others. The design process was characterized by the incorporation of aspects reviewed and programmed, seeking them compatible and have an economically viable building, socio-spatial quality and energy efficient. The results show that it is possible to obtain a building that meets the constraints of the program that provides housing and energy efficiency level A - and many other environmental qualities and constructive, particularly through architectural design

Architecture for IoT Node and Platform

Only recently, during the past five years, consumer electronics has been evolving rapidly. Many products have started to include “smart home” capabilities, enabling communication and interoperability of various smart devices. Even more devices and sensors can be remote controlled and monitored through cloud services. While the smart home systems have become very affordable to average consumer compared to the early solutions decades ago, there are still many issues and things that need to be fixed or improved upon: energy efficiency, connectivity with other devices and applications, security and privacy concerns, reliability, and response time. This paper focuses on designing Internet of Things (IoT) node and platform architectures that take these issues into account, notes other currently used solutions, and selects technologies in order to provide better solution. The node architecture aims for energy efficiency and modularity, while the platform architecture goals are in scalability, portability, maintainability, performance, and modularity. Moreover, the platform architecture attempts to improve user experience by providing higher reliability and lower response time compared to the alternative platforms. The architectures were developed iteratively using a development process involving research, planning, design, implementation, testing, and analysis. Additionally, they were documented using Kruchten’s 4+1 view model, which is used to describe the use cases and different views of the architectures. The node architecture consisted of energy efficient hardware, FC3180 microprocessor and CC2520 RF transceiver, modular operating system, Contiki, and a communication protocol, AllJoyn, used for providing better interoperability with other IoT devices and applications. The platform architecture provided reliable low response time control, monitoring, and initial setup capabilities by utilizing web technologies on various devices such as smart phones, tablets, and computers. Furthermore, an optional cloud service was provided in order to control devices and monitor sensors remotely by utilizing scalable high performance technologies in the backend enabling low response time and high reliability.

A new distributed MIKEY mode to secure e-health applications.

Securing e-health applications in the context of Internet of Things (IoT) is challenging. Indeed, resources scarcity in such environment hinders the implementation of existing standard based protocols. Among these protocols, MIKEY (Multimedia Internet KEYing) aims at establishing security credentials between two communicating entities. However, the existing MIKEY modes fail to meet IoT specificities. In particular, the pre-shared key mode is energy efficient, but suffers from severe scalability issues. On the other hand, asymmetric modes such as the public key mode are scalable, but are highly resource consuming. To address this issue, we combine two previously proposed approaches to introduce a new hybrid MIKEY mode. Indeed, relying on a cooperative approach, a set of third parties is used to discharge the constrained nodes from heavy computational operations. Doing so, the pre-shared mode is used in the constrained part of the network, while the public key mode is used in the unconstrained part of the network. Preliminary results show that our proposed mode is energy preserving whereas its security properties are kept safe.

Computational modelling of non-equilibrium condensing steam flows in low-pressure steam turbines

The steam turbines play a significant role in global power generation. Especially, research on low pressure (LP) steam turbine stages is of special importance for steam turbine man- ufactures, vendors, power plant owners and the scientific community due to their lower efficiency than the high pressure steam turbine stages. Because of condensation, the last stages of LP turbine experience irreversible thermodynamic losses, aerodynamic losses and erosion in turbine blades. Additionally, an LP steam turbine requires maintenance due to moisture generation, and therefore, it is also affecting on the turbine reliability. Therefore, the design of energy efficient LP steam turbines requires a comprehensive analysis of condensation phenomena and corresponding losses occurring in the steam tur- bine either by experiments or with numerical simulations. The aim of the present work is to apply computational fluid dynamics (CFD) to enhance the existing knowledge and understanding of condensing steam flows and loss mechanisms that occur due to the irre- versible heat and mass transfer during the condensation process in an LP steam turbine. Throughout this work, two commercial CFD codes were used to model non-equilibrium condensing steam flows. The Eulerian-Eulerian approach was utilised in which the mix- ture of vapour and liquid phases was solved by Reynolds-averaged Navier-Stokes equa- tions. The nucleation process was modelled with the classical nucleation theory, and two different droplet growth models were used to predict the droplet growth rate. The flow turbulence was solved by employing the standard k-ε and the shear stress transport k-ω turbulence models. Further, both models were modified and implemented in the CFD codes. The thermodynamic properties of vapour and liquid phases were evaluated with real gas models. In this thesis, various topics, namely the influence of real gas properties, turbulence mod- elling, unsteadiness and the blade trailing edge shape on wet-steam flows, are studied with different convergent-divergent nozzles, turbine stator cascade and 3D turbine stator-rotor stage. The simulated results of this study were evaluated and discussed together with the available experimental data in the literature. The grid independence study revealed that an adequate grid size is required to capture correct trends of condensation phenomena in LP turbine flows. The study shows that accurate real gas properties are important for the precise modelling of non-equilibrium condensing steam flows. The turbulence modelling revealed that the flow expansion and subsequently the rate of formation of liquid droplet nuclei and its growth process were affected by the turbulence modelling. The losses were rather sensitive to turbulence modelling as well. Based on the presented results, it could be observed that the correct computational prediction of wet-steam flows in the LP turbine requires the turbulence to be modelled accurately. The trailing edge shape of the LP turbine blades influenced the liquid droplet formulation, distribution and sizes, and loss generation. The study shows that the semicircular trailing edge shape predicted the smallest droplet sizes. The square trailing edge shape estimated greater losses. The analysis of steady and unsteady calculations of wet-steam flow exhibited that in unsteady simulations, the interaction of wakes in the rotor blade row affected the flow field. The flow unsteadiness influenced the nucleation and droplet growth processes due to the fluctuation in the Wilson point.

Data-Aware Scheduling in Datacenters

Datacenters have emerged as the dominant form of computing infrastructure over the last two decades. The tremendous increase in the requirements of data analysis has led to a proportional increase in power consumption and datacenters are now one of the fastest growing electricity consumers in the United States. Another rising concern is the loss of throughput due to network congestion. Scheduling models that do not explicitly account for data placement may lead to a transfer of large amounts of data over the network causing unacceptable delays. In this dissertation, we study different scheduling models that are inspired by the dual objectives of minimizing energy costs and network congestion in a datacenter. As datacenters are equipped to handle peak workloads, the average server utilization in most datacenters is very low. As a result, one can achieve huge energy savings by selectively shutting down machines when demand is low. In this dissertation, we introduce the network-aware machine activation problem to find a schedule that simultaneously minimizes the number of machines necessary and the congestion incurred in the network. Our model significantly generalizes well-studied combinatorial optimization problems such as hard-capacitated hypergraph covering and is thus strongly NP-hard. As a result, we focus on finding good approximation algorithms. Data-parallel computation frameworks such as MapReduce have popularized the design of applications that require a large amount of communication between different machines. Efficient scheduling of these communication demands is essential to guarantee efficient execution of the different applications. In the second part of the thesis, we study the approximability of the co-flow scheduling problem that has been recently introduced to capture these application-level demands. Finally, we also study the question, "In what order should one process jobs?'' Often, precedence constraints specify a partial order over the set of jobs and the objective is to find suitable schedules that satisfy the partial order. However, in the presence of hard deadline constraints, it may be impossible to find a schedule that satisfies all precedence constraints. In this thesis we formalize different variants of job scheduling with soft precedence constraints and conduct the first systematic study of these problems.

Architectural-Physical Co-Design of 3D CPUs with Micro-Fluidic Cooling

The performance, energy efficiency and cost improvements due to traditional technology scaling have begun to slow down and present diminishing returns. Underlying reasons for this trend include fundamental physical limits of transistor scaling, the growing significance of quantum effects as transistors shrink, and a growing mismatch between transistors and interconnects regarding size, speed and power. Continued Moore's Law scaling will not come from technology scaling alone, and must involve improvements to design tools and development of new disruptive technologies such as 3D integration. 3D integration presents potential improvements to interconnect power and delay by translating the routing problem into a third dimension, and facilitates transistor density scaling independent of technology node. Furthermore, 3D IC technology opens up a new architectural design space of heterogeneously-integrated high-bandwidth CPUs. Vertical integration promises to provide the CPU architectures of the future by integrating high performance processors with on-chip high-bandwidth memory systems and highly connected network-on-chip structures. Such techniques can overcome the well-known CPU performance bottlenecks referred to as memory and communication wall. However the promising improvements to performance and energy efficiency offered by 3D CPUs does not come without cost, both in the financial investments to develop the technology, and the increased complexity of design. Two main limitations to 3D IC technology have been heat removal and TSV reliability. Transistor stacking creates increases in power density, current density and thermal resistance in air cooled packages. Furthermore the technology introduces vertical through silicon vias (TSVs) that create new points of failure in the chip and require development of new BEOL technologies. Although these issues can be controlled to some extent using thermal-reliability aware physical and architectural 3D design techniques, high performance embedded cooling schemes, such as micro-fluidic (MF) cooling, are fundamentally necessary to unlock the true potential of 3D ICs. A new paradigm is being put forth which integrates the computational, electrical, physical, thermal and reliability views of a system. The unification of these diverse aspects of integrated circuits is called Co-Design. Independent design and optimization of each aspect leads to sub-optimal designs due to a lack of understanding of cross-domain interactions and their impacts on the feasibility region of the architectural design space. Co-Design enables optimization across layers with a multi-domain view and thus unlocks new high-performance and energy efficient configurations. Although the co-design paradigm is becoming increasingly necessary in all fields of IC design, it is even more critical in 3D ICs where, as we show, the inter-layer coupling and higher degree of connectivity between components exacerbates the interdependence between architectural parameters, physical design parameters and the multitude of metrics of interest to the designer (i.e. power, performance, temperature and reliability). In this dissertation we present a framework for multi-domain co-simulation and co-optimization of 3D CPU architectures with both air and MF cooling solutions. Finally we propose an approach for design space exploration and modeling within the new Co-Design paradigm, and discuss the possible avenues for improvement of this work in the future.

Todo Brasileiro merece nível A : habitação multifamiliar para o programa minha casa minha vida energeticamente eficiente

This thesis describes the theoretical, methodological and programmatic proposal for a multifamily residential building located in the urban expansion area of Parnamirim/RN, inserted in the program Minha Casa Minha Vida and level of energy efficiency "A", as the RegulamentoTécnico de Qualidade (RTQ-R/INMETRO) for residential buildings. The development project initially consists of procedures as the study of theoretical, architectural programming and cases studies. With the delimitation of a field solution, situated between the reference and the context, proposals are studied to determine the solution and architectural detailing of the proposal. The architectural program was built based on the method of Problem Seeking (Peña and Parshall, 2001) and research has highlighted aspects of reducing the environmental impact and of the program Minha Casa Minha Vida , among others. The design process was characterized by the incorporation of aspects reviewed and programmed, seeking them compatible and have an economically viable building, socio-spatial quality and energy efficient. The results show that it is possible to obtain a building that meets the constraints of the program that provides housing and energy efficiency level A - and many other environmental qualities and constructive, particularly through architectural design

Numerical modeling of vertical earth pipe cooling system for hot and humid subtropical climate

Energy crisis is one of the major problems facing the progress of human society. There are several energy-efficient technologies that can be applied to save energy and make a sustainable environment. Passive air cooling of earth pipe cooling technology is one of them to reduce the energy consumption for hot and humid subtropical climates. The technology works with a long buried pipe with one end for intake air and the other end for providing air cooled by soil to the desired space such as residential, agricultural, or industrial buildings. It can be an attractive economical alternative to conventional cooling since there are no compressors or any customary mechanical unit. This chapter reports the performance of a vertical earth pipe cooling system for a hot and humid subtropical climatic zone in Queensland, Australia. A series of buried pipes were installed in vertical arrangement in order to increase earth pipe cooling performance. To measure the performance of the system, a numerical model was developed and simulated using the CFD software Fluent in ANSYS 15.0. Data were collected from two modeled rooms built from two shipping containers and installed at the Sustainable Precinct at Central Queensland University, Rockhampton, Australia. The impact of air temperature and velocity on room cooling performance has also been assessed. A temperature reduction of 1.82 °C was observed in the room connected to the vertical earth pipe cooling system, which will save the energy cost for thermal cooling in buildings.

Flexible roll forming of an automotive component with variable depth

Roll forming is a cost and energy efficient process for the manufacture of Ultra High Strength Steel (UHSS) structural and crash components in the automotive industry. The conventional roll forming process is limited to component having constant cross-section, while the recently deveoped Flexible Roll Forming (FRF) process allows the production of components in which the section varies over the length of the aprt; this permits optimization in terms of strength and weight. There has been an uptake in FRF in the heavy vehicle industry for the production of long and high strength structural parts, but passenger car bodies are more complex and generally parts require variations in width and also in depth. The widespread application of FRF in the automotive industy therefore requires the forming of components that have intricate variations in profile depth over the length of the part.
This work is a first comprehensive study of the FRF of high strength structural components with variable depth. For this, the FRF of an automotive bumper section is analyzed numerically using the commercial software package COPRA® FEA RF. A detailed analysis of the distribution and history of plastic strain in longitudinal, transcerse and thickness directions is performed and related to the shape defects observed in the proecss. The analysis shows that when forming variable depth components, zones of compressive longitudinal strain exist that lead to wrinkling defects. These can be reduced by applying additional flange contact during the operation. In general the current work suggests that the FRF of high strength components with variable depth is possible and can compete with other forming methods currently used in the automotive industry.