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(8763150), Amanda Johnston. "Teacher Talk in Engineering Design Projects." Thesis, 2020.
Знайти повний текст джерелаTeacher talk is a major way in which instructors support and provide scaffolding for their students, frame their pedagogies, model ways of thinking, and convey ideas. Effective teacher talk about engineering design at all levels of students’ educational experiences has the potential to better prepare students for success in engineering and increase the diversity of engineering fields. However, the most effective ways for teachers to talk to their students during engineering design are not well understood. This three-study dissertation examines the ways in which instructors use talk to interact with their students through a variety of different engineering design settings and contexts, with potential implications to improve and educate how teachers present engineering to their students. Overall, this thesis addresses the research question: How do instructors (teachers and professors) use talk interactions to scaffold students in engineering design? The first study is a case study that focuses on the whole class verbal interactions of an experienced and successful teacher throughout the entirety of a month-long life science-based STEM integration unit in a 6th grade classroom. Results show that this teacher’s talk helped to integrate engineering with the science and mathematics content of the unit and modeled the practices of informed designers to help students learn engineering in the context of their science classroom. He framed lessons around problem scoping, incorporated engineering ideas into scientific verbal interactions and aligned individual lessons and the overall unit with the engineering design process. The second study uses naturalistic inquiry to examine how six different teachers of 6th, 7th, and 8th grades talked to their students while the students were actively working in small teams on engineering design projects. Results indicate that the teachers had conversations with the students about many areas of engineering, demonstrating that middle school teachers can have high-level conversations with their students about their design ideas. However, when students struggle to communicate their ideas, the different levels of support outlined in the coding framework and examples provide a structure of support for teachers to give their students. Additionally, there were many areas of engineering that were underemphasized in the teachers’ talk and each teacher had different emphasis. The third study examines how professors in mechanical and biomedical engineering talk to their students during introductory engineering design projects. Results show that the three professors used their talk to support their role as a guide and mentor to students during their projects, although they had different goals with their mentoring. They used their talk to push students’ ideas to consider their problems more broadly, encouraged students to brainstorm diverse out-of-the-box ideas, supported teaming, and modeled engineering language. They maintained a focus on non-technical content, including the iterative nature of design, teaming, and communication, but made references to how students would apply this knowledge in future, more technical projects. The professors supported many challenges for novice designers, including supporting prototype development to represent ideas and iterating to improve their ideas, but were not comprehensive in their support of other challenges, especially problem scoping, testing and troubleshooting, and reflecting on the process. The final chapter of this dissertation presents a synthesis across the three studies and a summary of the implications for teaching. These implications include many examples of high-quality engineering conversations with students at different levels of their education, identification of aspects of engineering education that are underemphasized in teachers’ talk to their students, and connections to needed areas of support and professional development for teachers.
(7011485), Altyngul Jumabayeva. "Model-based Analysis and Design of Color Screen Sets for Clustered-Dot Periodic Halftoning and Design of Monochrome Screens Based on Direct Binary Search for Aperiodic Dispersed-Dot Halftoning." Thesis, 2020.
Знайти повний текст джерелаPeriodic clustered-dot halftones are widely used in electrophotographic printers due to the relatively poor print stability of this class of printers. It is important to analyze the nature and the causes of perceived fluctuation in order to understand the factors that prevent the high-end digital presses from achieving the same print quality as the commercial offset presses. In order to better approximate the screen sets used for the commercial offset presses, irregular screen sets can be considered. We start by developing a set of candidate screen tile-vectors that best fit the specified screen frequency, screen angle, and printer resolution. We then perform Fourier-based analysis of regular and irregular periodic, clustered-dot halftone textures in order to understand how perceived fluctuation relates to the halftoning technology. After exploring the search for the best single separation geometry, we consider the superposition of multiple periodic clustered-dot halftones, and propose to apply HVS-based model, which assists us in finding the best color assignments to the superimposed halftones. It turned out that the choice of the best color assignments depends on different combinations of colorant absorptance values, hence we propose to apply different color assignments within the image depending on the local color and content of the image. Next, we propose a step-by-step screen design for standard and high resolution periodic irregular clustered-dot halftones. Finally, we presented monochrome DBS-based screen design with overlapping clusters of 2 × 2 or 3 × 3 pixels, which can also be used in electrophotographic printers.
(11016081), Yang Wang. "DESIGN AND IMPLEMENTATIONS OF OPEN-SOURCE AG IOT DEVICES FOR FARM MACHINERY DATA ACQUISITION AND INTEGRATED ANALYTICS." Thesis, 2021.
Знайти повний текст джерелаresultant clusters between on-road and in-field data samples as well as normal and anomalous activities. The second problem concentrates on combine unloading event detections using GPS tracks of multiple combines in 16 harvest sessions. The identified events from a novel algorithm that couples Interacting Multiple Models filtering and composite rules were utilized to estimate the total yield for each session. The estimated yields had an overall accuracy of over 90% when comparing to the actual weight ticket records. Lastly, two instantaneous metrics, instantaneous area capacity and swath utilization, were proposed and estimated using GPS tracks of multiple combines in 7 different fields during various harvest years. A novel algorithm was created for estimating instantaneous actual harvested area and swath utilization. This enabled exact computations of instantaneous metrics as oppose to conventional rough estimates of area capacity. Harvest performances were evaluated both temporally and geospatially by machines and years. It was discovered that three contributing factors that lead to high area capacity were wide header attachments, high harvesting speed, and uniform harvesting patterns. Moreover, it was found that the benefit of a wider header might diminish if the harvesting speed was low.
(5929889), Joo Min Kim. "Behavior, Analysis and Design of Steel-Plate Composite (SC) Walls for Impactive Loading." Thesis, 2019.
Знайти повний текст джерела(5930033), Curtis P. Martin. "RATIONAL DESIGN OF TYPE II KINASE INHIBITORS VIA NOVEL MULTISCALE VIRTUAL SCREENING APPROACH." Thesis, 2019.
Знайти повний текст джерела(6997520), Bo Zhang. "A DESIGN PARADIGM FOR DC GENERATION SYSTEM." Thesis, 2020.
Знайти повний текст джерела(5930180), Ashish Ranjan. "Energy-efficient Memory System Design with Spintronics." Thesis, 2019.
Знайти повний текст джерелаModern computing platforms, from servers to mobile devices, demand ever-increasing amounts of memory to keep up with the growing amounts of data they process, and to bridge the widening processor-memory gap. A large and growing fraction of chip area and energy is expended in memories, which face challenges with technology scaling due to increased leakage, process variations, and unreliability. On the other hand, data intensive workloads such as machine learning and data analytics pose increasing demands on memory systems. Consequently, improving the energy-efficiency and performance of memory systems is an important challenge for computing system designers.
Spintronic memories, which offer several desirable characteristics - near-zero leakage, high density, non-volatility and high endurance - are of great interest for designing future memory systems. However, these memories are not drop-in replacements for current memory technologies, viz. Static Random Access Memory (SRAM) and Dynamic Random Access Memory (DRAM). They pose unique challenges such as variable access times, and require higher write latency and write energy. This dissertation explores new approaches to improving the energy efficiency of spintronic memory systems.
The dissertation first explores the design of approximate memories, in which the need to store and access data precisely is foregone in return for improvements in energy efficiency. This is of particular interest, since many emerging workloads exhibit an inherent ability to tolerate approximations to their underlying computations and data while still producing outputs of acceptable quality. The dissertation proposes that approximate spintronic memories can be realized either by reducing the amount of data that is written to/read from them, or by reducing the energy consumed per access. To reduce memory traffic, the dissertation proposes approximate memory compression, wherein a quality-aware memory controller transparently compresses/decompresses data written to or read from memory. For broader applicability, the quality-aware memory controller can be programmed to specify memory regions that can tolerate approximations, and conforms to a specified error constraint for each such region. To reduce the per-access energy, various mechanisms are identified at the circuit and architecture levels that yield substantial energy benefits at the cost of small probabilities of read, write or retention failures. Based on these mechanisms, a quality-configurable Spin Transfer Torque Magnetic RAM (STT-MRAM) array is designed in which read/write operations can be performed at varying levels of accuracy and energy at runtime, depending on the needs of applications. To illustrate the utility of the proposed quality-configurable memory array, it is evaluated as an L2 cache in the context of a general-purpose processor, and as a scratchpad memory for a domain-specific vector processor.
The dissertation also explores the design of caches with Domain Wall Memory (DWM), a more advanced spintronic memory technology that offers unparalleled density arising from a unique tape-like structure. However, this structure also leads to serialized access to the bits in each bit-cell, resulting in increased access latency, thereby degrading overall performance. To mitigate the performance overheads, the dissertation proposes a reconfigurable DWM-based cache architecture that modulates the active bits per tape with minimal overheads depending on the application's memory access characteristics. The proposed cache is evaluated in a general purpose processor and improvements in performance are demonstrated over both CMOS and previously proposed spintronic caches.
In summary, the dissertation suggests directions to improve the energy efficiency of spintronic memories and re-affirms their potential for the design of future memory systems.
(6618812), Harsh Patel. "IMPLEMENTING THE SUPERPAVE 5 ASPHALT MIXTURE DESIGN METHOD IN INDIANA." Thesis, 2019.
Знайти повний текст джерела(6641012), Genisson Silva Coutinho. "FACULTY BELIEFS AND ORIENTATIONS TO TEACHING AND LEARNING IN THE LAB: AN EXPLORATORY CASE STUDY." Thesis, 2019.
Знайти повний текст джерела(8796875), Dana L. Moryl. "A STUDY ON APHONOPELMA SEEMANI BIOMECHANICS OF MOTION WITH EMPHASIS ON POTENTIAL FOR BIOMIMETIC ROBOTICS DESIGN." Thesis, 2020.
Знайти повний текст джерелаWith a stable center of mass, pneumatic-aided movement, and the ability to scale multiple terrain types, the uniquely efficient and lightweight form of spiders has changed the way we think about robotic design. While the number of papers on arachnid biomechanics and spider-based biomimetic robots has been increasing in recent years, the style of analysis and the motion-types analyzed have barely changed since the 1980s. Current analyses are based on a force plate and treadmill design, in which the spider is induced into an escape run. This environmental change can affect the movements of the spider. Here I propose a novel method of testing the biomechanical and kinematic properties of spiders using a tank with a built-in sensor matrix which allows for a more natural environment for the specimens and provides force data from individual legs. The system detects a minimum force of .0196 N and has a sampling rate of 1,000 samples /second, which allows for the analysis of forces during the step. Aphonopelma seemanni, a tarantula commonly used in such research, but whose forces during movement have to date not been analyzed, was recorded walking across the matrix, and the forces, step patterns, joint angles, and center of mass deviations were recorded. Walking indicated significantly different step pattern traits than current literature, and forces per leg (.07281 N±.0235) recorded were much smaller than expected in comparison to other spiders. Statistical analysis also indicated no changes in walking movement over a range of temperatures, which also varies from literature. These findings indicate that further research on spiders should be done with respect to walking gaits in order to improve upon current biomimetic models.
(9181898), Hoda Ehsan. "A Multiple Case Study to Capture and Support the Engineering Design Thinking of Children with Mild Autism." Thesis, 2020.
Знайти повний текст джерелаResearch in pre-college engineering education has been on a sharp rise in the last two decades. However, less research has been conducted to explore and characterize the engineering thinking and engagement of young children, with limited attention to children with special needs. Conversations on broadening participation and diversity in engineering usually center around gender, socio-economic status, race and ethnicity, and to a lesser extent on neurodiversity. Autism is the fastest growing neurodiverse population who have the potential to succeed in engineering. In order to promote the inclusion of children with autism in engineering education, we need to gain a deep understanding of their engineering experiences.
The overarching research question that I intend to answer is how do children with mild autism engage in engineering design tasks? Grounding this study in theories of Constructivism and Defectology, I focused on children’s engagement in engineering design practices and the ways their parents supported their engagements. To engage children with mild autism in engineering, I have developed an engineering design activity by considering suggestions from these theories and previous literature on elementary-aged children’s engagement in engineering design, and by focusing on individuals with mild autism strengths in STEM. This activity provides opportunities for children to interact with their parents while solving engineering design problems. The families are asked to use a construction kit and design their solutions to the problem introduced in the engineering design activity. The engineering design activity consists of a series of five challenges, ranging from well- to ill-structed.
This is an exploratory qualitative case study, using a multiple case approach. These cases include 9-year-old children with autism and their families. Video recordings of the families are the main source of data for this study. Triangulation of data happens through interviewing parents and children, pictures of children’s artifacts (i.e. their prototypes), and use of the Empathizing-Systemizing survey to capture background information and autism characteristics. Depending on the data source, I utilized different methods including video analysis, thematic analysis and artifact analysis.
This study expands our understanding of what engineering design can look like when enacted by children with mild autism, particularly as engineering design is considered to be a very iterative process with multiple phases and actions associated with it. The findings of this study show that these children can engage in all engineering design phases in a very iterative process. Similarities and differences between these children’s design behaviors and the existing literature were discussed. Additionally, some of the behaviors these children engaged in resemble the practices of experienced designers and engineers. The findings of this study suggest that while children were not socially interacting with their family members when addressing the challenges, their parents played an important role in their design engagement. Parents used different strategies during the activity that supported and facilitated children’s engineering design problem-solving. These strategies include soliciting information, providing guidance, assisting both verbally and hands-on, disengagement and being a student of the child.
This study provides aspirations for future research with the aim to promote the inclusion of children with neurodiversity. It calls for conducting similar research in different settings to capture the engineering design engagement of children with mild autism when interacting with teachers, peers, siblings in different environments. Additionally, the findings of this study have implications for educators and curators of engineering learning resources.
(6823670), Priyadarshini Panda. "Learning and Design Methodologies for Efficient, Robust Neural Networks." Thesis, 2019.
Знайти повний текст джерела(5929802), Andrew M. Jackson. "A Case Study of High-School Student Self-Regulation Responses to Design Failure." Thesis, 2019.
Знайти повний текст джерела(9503810), Jose Adrian Chavez Velasco. "COMPREHENSIVE STUDY OF THE ENERGY CONSUMPTION OF MEMBRANES AND DISTILLATION." Thesis, 2020.
Знайти повний текст джерелаMolecular
separations are essential in the production of many chemicals and purified
products. Of all the available separation technologies, distillation, which is
a thermally driven process, has been and continues to be one of the most
utilized separation methods in chemical and petrochemical plants. Although
distillation and other commercial technologies fulfilled most of the current
separation needs, the energy-intensive nature of many molecular separations and
the growing concern of reducing CO2 emissions has led to intense research to
seek for more energy-efficient separation processes.
Among the emerging separation technologies alternative to distillation, there is special attention on non-thermally driven methods, such as membranes. The growing interest in non-thermal methods, and particularly in the use of membranes, has been influenced significantly from the widespread perception that they have a potential to be markedly less energy-intensive than thermal methods such as distillation. Even though many publications claim that membranes are more energy-efficient than distillation, except for water desalination, the relative energy intensity between these processes in the separation of chemical mixtures has not been deeply studied in the literature. One of the objectives of this work focuses on introducing a framework for comparative analysis of the energy intensity of membranes and distillation.
A complication generally encountered when comparing the energy consumption of membranes against an alternative process is that often the purity and recovery that can be achieved through a single membrane stage is limited. While using a multi-stage membrane process is a plausible solution to achieve both high purity and recovery, even for a simple binary separation, finding the most suitable multistage membrane process is a difficult task. This is because, for a given separation, there exists multiple cascades that fulfill the separation requirements but consume different amounts of energy. Moreover, the energy requirement of each cascade depends on the operating conditions. The first part of this work is dedicated to the development of a Mixed Integer Non-linear Program (MINLP) which allows for a given gaseous or liquid binary separation, finding the most energy-efficient membrane cascade. The permeator model, which is derived from a combination of the cross-flow model and the solution diffusion theory, and is originally expressed as a differential-algebraic equation (DAE) system, was integrated analytically before being incorporated in the optimization framework. This is in contrast to the common practice in the literature, where the DAE system is solved using various discretization techniques. Since many of the constraints have a non-convex nature, local solvers could get trapped in higher energy suboptimal solutions. While an option to overcome this limitation is to use a global solver such as BARON, it fails to solve the MINLP to the desired optimality in a reasonable amount of time for most of the cases. For this reason, we derive additional cuts to the problem by exploiting the mathematical properties of the governing equations and from physical insights. Through numerical examples, we demonstrate that the additional cuts aid BARON in expediting the convergence of branch-and-bound and solve the MINLP within 5%-optimality in all the cases tested in this work.
The proposed optimization model allows identifying membrane cascades with enhanced energy efficiency that could be potentially used for existing or new separations. In addition, it allows to compare the optimum energy consumption of a multistage membrane process against alternative separations methods and aid in the decision of whether or not to use a membrane system. Nevertheless, it should be noted that when a membrane process or any other non-thermal separation process is compared with a thermal process such as distillation, an additional complication often arises because these processes usually use different types of energies. Non-thermal processes, such as membranes, consume electrical energy as work, whereas thermal processes, such as distillations, usually consume heat, which is available in a wide range of temperatures. Furthermore, the amount of fuel consumed by a separation process strongly depends on how its supplied energy is produced, and how it is energy integrated with the rest of the plant. Unfortunately, common approaches employed to compare the energy required by thermal and non-thermal methods often lead to incorrect conclusions and have driven to the flawed perception that thermal methods are inherently more energy-intensive than non-thermal counterparts. In the second part of this work, we develop a consistent framework that enables a proper comparison of the energy consumption between processes that are driven by thermal and non-thermal energy (electrical energy). Using this framework, we refute the general perception that thermal separation processes are necessarily the most energy-intensive and conclusively show that in several industrially important separations, distillation processes consume remarkably lower fuel than non-thermal membrane alternatives, which have often been touted as more energy efficient.
In order to gain more understanding of the conditions where membranes or distillation are more energy-efficient, we carried out a comprehensive analysis of the energy consumed by these two processes under different operating conditions. The introduced energy comparison analysis was applied to two important separation examples; the separation of p-xylene/o-xylene, and propylene/propane. Our results showed that distillation is more energy favored than membranes when the target purity and recovery of the most volatile (resp. most permeable) component in the distillate (resp. permeate) are high, and particularly when the feed is not too concentrated in the most volatile (resp. most permeable) component. On the other hand, when both the recovery and purity of the most volatile (resp. most permeable) component are required at moderate levels, and particularly when the feed is highly enriched in the most volatile (resp. most permeable) component, membranes show potential to save energy as compared to distillation.
(6659816), Qizhen Li. "Coplanar Waveguide-based Low Pass Filter Design with Non-uniform Signal Trace and Ground Planes Using Different Optimization Algorithms." Thesis, 2019.
Знайти повний текст джерелаIn this study, a novel and systematic methodology
for the design and optimization of conductor-backed coplanar waveguide (CB-CPW)
based low pass filter (LPF) is proposed. The width of the signal trace is
continuously varied using a truncated Fourier series, and the adjacent gaps are
designed in several types established on a specific optimization setup to
obtain predefined electrical characteristics with maximum compactness taking
into account physical constraints. Trust-region-reflective algorithm (TRRA),
genetic algorithm (GA), and particle swarm optimization algorithm (PSO) are taken
into account to minimize the developed bound-constrained non-linear objective
function respectively.
All types are programmed and analytically
verified in MATLAB. Solutions include design parameters such as the physical
length and width of the structure, which will be drawn in AutoCAD later on.
Also, the optimized layouts are exported to Ansys High Frequency Structure
Simulation (HFSS) software for simulation and validation. Non-uniform CB-CPW
LPFs are optimized and simulated over a frequency range of 0-6 GHz with a
cutoff frequency of 2 GHz. Simulation results show a good agreement with the
analytical ones.
Palmer, Kent D. "Emergent design : explorations in systems phenomenology in relation to ontology, hermeneutics and the meta-dialectics of design." 2009. http://arrow.unisa.edu.au:8081/1959.8/74458.
Повний текст джерела(8815394), Claudio Freitas. "Understanding Engineering Education in Displacement: A Qualitative Study of "Localized Engineering" in Two Refugee Camps." Thesis, 2020.
Знайти повний текст джерела(11167785), Nicolae Christophe Iovanac. "GENERATIVE, PREDICTIVE, AND REACTIVE MODELS FOR DATA SCARCE PROBLEMS IN CHEMICAL ENGINEERING." Thesis, 2021.
Знайти повний текст джерела(9179804), Daniel Christopher Horvath. "Analysis and Design of Electric Machines Using 2D Method of Moments." Thesis, 2020.
Знайти повний текст джерела(9726050), Onkar V. Sonur. "The Sustainable Manufacturing System Design Decomposition." Thesis, 2020.
Знайти повний текст джерела(6983504), Zhou Zeng. "Sensitivity Analysis and Topology Optimization in Plasmonics." Thesis, 2019.
Знайти повний текст джерела(8740677), Jeremy Sickmiller. "REAL TIME CONTROL OF MANUFACTURING UTILIZING A MANUFACTURING EXECUTION SYSTEM (MES)." Thesis, 2020.
Знайти повний текст джерела(10686675), Kyle T. Waggoner. "Design of YBCO-Based Machines Using 2D Method of Moments." Thesis, 2021.
Знайти повний текст джерела(7022165), Raj Sahu. "Design Paradigm for Modular Multilevel Converter Based Generator Rectifier Systems." Thesis, 2019.
Знайти повний текст джерела(7241471), Michael J. Dziekan. "DESIGN OF A HYBRID HYDROGEN-ON-DEMAND AND PRIMARY BATTERY ELECTRIC VEHICLE." Thesis, 2021.
Знайти повний текст джерелаIn recent years lithium-ion battery electric vehicles and stored hydrogen electric vehicles have been developed to address the ever-present threat of climate change and global warming. These technologies have failed to achieve profitability at costs consumers are willing to bear when purchasing a vehicle. IFBattery, Inc. has developed a unique primary battery chemistry which simultaneously produces both electricity and hydrogen-on-demand while being both low cost and without carbon emissions. In order to determine the feasibility of the IFBattery chemistry for mobile applications, a prototype golf cart was constructed as the first public application of IFBattery technology. The legacy lead acid batteries of the prototype golf cart were replaced with an IFBattery chemistry tuned to primarily produce hydrogen-on-demand with supplemental electricity. Hydrogen produced by the IFBattery was purified and then fed into a hydrogen fuel cell where electricity was produced to power the vehicle. Electricity from the IFBattery was converted to the common voltage of the golf cart and also used to power the vehicle. Validation testing of the IFBattery powered golf cart demonstrated favorable results as an alternative to both lithium-ion battery and stored hydrogen technologies, and displayed potential for future applications.
(10520390), Chanel M. Beebe. "SYSTEMS THINKING IN SOCIALLY ENGAGED DESIGN SETTINGS." Thesis, 2021.
Знайти повний текст джерелаSocially engaged design programs, community development coalitions, and intentional and unintentional design spaces are rich with expertise and thinkers who are developing solutions to very pressing, yet complicated problems. Little research has been conducted on the expertise and sense-making of the community partners who participate in these situations. The goal of this research endeavor is to unpack the ways various community partners make meaning of their design experiences by answering the question: What evidence of system’s thinking can be seen in the way community partners describe their work or context? A qualitative research study was conducted in which three community partners were interviewed at various points during their engagement with socially engaged design programs. They demonstrated their systems thinking ability most strongly across the following domains: differentiate and qualify elements, explore multiple perspectives, consider issues appropriately, recognize systems, identify and characterize relationships. These findings imply that the community partners are not only capable of systems thinking but have the potential to be more deeply involved in developing solutions within these settings. Future studies should investigate systems thinking beyond socially engaged design in formal settings and should consider investigation protocols that more directly surface systems thinking domains. Overall, this study contributes to existing work in systems thinking by calling for a more expansive and inclusive engagement of community partners in socially engaged work.
(8120606), Zhaoyang Li. "Design and Simulation of Microwave Filters Using Non-uniform Transmission Line and Superformula." Thesis, 2019.
Знайти повний текст джерела(5931200), Francisco Rivera-Abreu. "Dual Band Octagonal Microstrip Patch Antenna Design Method for Energy Harvesting." 2020.
Знайти повний текст джерела(9187337), Zhiyao Yang. "AN AMMONIA-BASED CHEMISORPTION HEAT PUMP FOR COLD CLIMATE: EXPERIMENTS AND MODELING FOR PERFORMANCE ANALYSIS AND DESIGN OPTIMIZATION." Thesis, 2020.
Знайти повний текст джерелаSpace and water heating contribute over 50% of all the residential building energy consumption and are especially major energy consumers in the cold climates. Meanwhile, conventional furnaces and boilers with energy efficiency limited to below 100% dominate the residential heating in the cold climate, and the electric vapor-compression heat pump capacity and efficiency decline drastically at low ambient temperatures. Thermally driven ammonia-based chemical adsorption (chemisorption) heat pump (CSHP) systems utilize the reversible chemical reaction between the ammonia vapor and solid sorbent to generate heat pumping effect, which can provide heating with much higher energy efficiency than existing cold-climate heating technologies. Despite the significant potential of energy efficiency improvement from existing technologies, most studies in the literature on chemisorption heat pump systems focus on adopting the technology for refrigeration and energy storage applications, with very limited investigations available for using the technology for producing heating in cold climates.
This thesis study is thus conducted to characterize the operation behavior and performance of a CSHP system under cold ambient conditions and further identify optimal design and control for such systems to achieve high performance. In this study, both experimental and modelling approaches are pursued to investigate a CSHP heating system from the perspective of the sorption material using the multiple-stage LiCl-ammonia reactions, to the novel adsorber component with hybrid heat pipe heat exchanger, and finally to the performance of the complete heat pump system. The experimental studies are based on a prototype CSHP system tested to identify the chemical kinetics of the sorption material, as well as the transient performance of the adsorber and the system. The calibrated chemical kinetics are then used in the development of a transient adsorber model to analyze the operation and improve design of the adsorber. The heating COP of the prototype system was measured to be 0.75-1.16 under ambient temperatures of 8-20 C. Finally, a dynamic system model is developed based on the dynamic models of the adsorber and other components in the system. The system model is validated against the experimental data and used to analyze the detailed energy flow and operation dynamic. Based on the inefficiencies revealed by the simulation of the current prototype system, an improved system design with reduced thermal mass and heat loss is introduced. Simulation of the improved system results in heating COP of 1.17 to 1.23 under -13.9 C to 8.3 C ambient, respectively.(7456577), Xiang Zhang. "A COUPLED THERMAL/ELECTRIC CIRCUIT MODEL FOR DESIGN OF MVDC CABLES." Thesis, 2019.
Знайти повний текст джерела(6622304), Juan S. Martinez. "Tactile Speech Communication: Design and Evaluation of Haptic Codes for Phonemes with Game-based Learning." Thesis, 2019.
Знайти повний текст джерела(6857492), Emilie A. Siverling. "Heat Transfer Conceptions Used in an Engineering Design-Based STEM Integration Unit: A Case of Struggle." Thesis, 2019.
Знайти повний текст джерела