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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Sistema produto-serviço sustentável (SPSS) e seus modelos de negócio: uma proposta de categorização / Sustainable product-service system and their business models: a propose of categorization

Zeithamer, Clécio Roque 28 August 2017 (has links)
Inúmeras alterações vêm acontecendo na sociedade contemporânea devido ao surgimento de novas tecnologias, fato esse que tem influenciado várias áreas do conhecimento e alterado de forma significativa o estilo de vida da sociedade. Um dos impactos que a comunidade vem experimentando devido ao seu atual modo de vida é um contínuo e vertiginoso uso dos recursos naturais, que consecutivamente produzem abalos ambientais. Em vista disso, está crescendo o grau de conscientização da sociedade, e as empresas estão sendo impelidas a responder e se responsabilizar pelos impactos negativos gerados por suas atividades, mudando assim, paulatinamente o cenário social e ambiental. Para sanar tal situação, uma nova ferramenta com base em serviços veio proporcionar um desenvolvimento econômico apoiado na desmaterialização do crescimento, conhecido como Sistema Produto-Serviço Sustentável (SPSS). Algumas das características deste sistema se alteram em virtude das necessidades do cliente ou de acordo com a solução, priorizando o atendimento de componentes tangíveis ou intangíveis. O objetivo do estudo é propor um Mapa Visual para categorização de Modelos de Negócio de Sistemas Produto-Serviço Sustentáveis. Em relação ao caminho metodológico para atingir o objetivo proposto, foi desenvolvida uma pesquisa de natureza aplicada, com abordagem qualitativa do problema, descritiva e se valendo de técnicas bibliográfica e documental, e estudo de caso de um mobiliário escolar informatizado. Como resultado da pesquisa, propõe-se um Mapa Visual, composto por 3 categorias, 9 sub-categorias e 45 critérios para categorização de Modelos de Negócio (MN) de SPSS. / Several changes occur in the contemporaneous society, in several areas of knowledge. The impacts produced generated in the last years due to technologies recently appeared, provoked significantly the society’s way of life. These impacts generate effects such the relationship between the current way of life and the increasing use of the natural resources. Therefore, increases gradually the enterprises’ awareness, the last ones responding for these impacts. In order to solve this situation, these enterprises developed a new tool based in services, to proportionate an economic development based in knowledge’s dematerialization, well known as Sustainable Product-Service System (SPSS). Some of the characteristics of this system can be changes, in virtue of the client’s needings or according to solution, prioritizing the attendance of the material and unmaterial components. Thus, it is intended through this study propose a categorization process for Business Models related to SPSS. Concernin the methodological way to achive the proposed goal, it was developed a research of applied nature, with a qualitative approach of the problem, being descriptive and using bibliographic and documental techniques, and being the case of study, an informatized scholar furniture. As a result of this research, it proposes a Visual Map, composed by three categories, 9 subcategories and 45 categorization creiteria of the SPSS Business Models.
62

Fuzzy-Rule-Based Failure Detection and Early Warning System for Lithium-ion Battery

Wu, Meng 05 September 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Lithium-ion battery is one kind of rechargeable battery, and also renewable, sustainable and portable. With the merits of high density, slow loss of charge when spare and no memory effect, lithium-ion battery is widely used in portable electronics and hybrid vehicles. Apart from its advantages, safety is a major concern for Lithium-ion batteries due to devastating incidents with laptop and cell phone batteries. Overcharge and over-discharge are two of the most common electrical abuses a lithium-ion battery suffers. In this thesis, a fuzzy-rule-based system is proposed to detect the over-charge and over-discharge failure in early time. The preliminary results for the failure signatures of overcharged and over-discharged lithium-ion are listed based on the experimental results under both room temperature and high temperature. A fuzzy-rule-based model utilizing these failure signatures is developed and validated. For over-charge case, the abnormal increase of the surface temperature and decrease of the voltage are captured. While for over discharge case, unusual temperature increase during overcharge phases and abnormal current decrease during overcharge phases are obtained. The inference engine for fuzzy-rule-based system is designed based on these failure signatures. An early warning signal will be given by this algorithm before the failure occurs. This failure detection and early warning system is verified to be effective through experimental validation. In the validation test, the proposed methods are successfully implemented in a real-time system for failure detection and early warning. The result of validation is compatible with the design expectation. Finally an accurate failure detection and early warning system is built and tested successfully.
63

Applying Lessons from Nature to Advance Computational Sustainable Design: Designing Industrial Landscapes and Transitions towards Neutrality

Charles, Michael T. January 2021 (has links)
No description available.
64

Cellulose-Based Hydrogels for High-Performance Buildings and Atmospheric Water Harvesting

Noor Mohammad Mohammad (17548365) 04 December 2023 (has links)
<p dir="ltr">Smart windows, dynamically adjusting optical transmittance, face global adoption challenges due to climatic and economic variability. Aiming these issues, we synthesized a methyl cellulose (MC) salt system with high tunability for intrinsic optical transmittance (89.3%), which can be applied globally to various locations. Specifically, the MC window has superior heat shielding potential below transition temperatures while turning opaque at temperatures above the Lower Critical Solution Temperature (LCST), reducing the solar heat gain by 55%. Such optical tunability is attributable to the particle size change triggered by the temperature-induced reversible coil-to-globular transition. This leads to effective refractive index and scattering modulation, making them prospective solutions for light management systems, an application ahead of intelligent fenestration systems. MC-based windows demonstrated a 9°C temperature decrease compared to double-pane windows on sunny days and a 5°C increase during winters in field tests, while simulations predict an 11% energy savings.</p><p dir="ltr">Incorporating MC-based phase change materials in passive solar panels indicated optimized energy efficiency, offering a sustainable alternative. Real-time simulations validate practical applicability in large-scale solar panels. Furthermore, a temperature-responsive sorbent with a dark layer demonstrates an optimal optical and water uptake performance. Transitioning between radiative cooling and solar heating, the sorbent exhibits high water harvesting efficiency in lab and field tests. With an adjustable LCST at 38 ℃, the cellulose-based sorbent presents a potential solution for atmospheric water harvesting, combining optical switching and temperature responsiveness for sustainable water access. Furthermore, the ubiquitous availability of materials, low cost, and ease-of-manufacturing will provide technological equity and foster our ambition towards net-zero buildings and sustainable future.</p>
65

Protection of Public and Worker Safety by Understanding Hazardous Chemical Air and Exposure Risks during Plastic Cured-In-Place-Pipe Manufacture and Use

Yoorae Noh (13113138) 18 July 2022 (has links)
<p>  </p> <p>Globally, communities are embracing the cured-in-place-pipe (CIPP) process due to the need to address damaged buried water and sewer pipes. CIPP involves the chemical manufacture of a new plastic pipe inside an existing buried water and sewer pipe, without the need for excavation. The process is popular because it can be 80% less costly than alternative methods and construction workers can be present for hours to not days to weeks. However, as CIPP use has grown, so have the number of hazardous material (HAZMAT) incidents caused by using this practice. Evacuations of daycare centers, schools, homes, healthcare, institutional, and other buildings have been caused. In some cases, chemical exposure victims have required medical assistance and hospital admission. For decades, organizations within the CIPP industry and municipalities have encouraged chemical waste discharge into ambient air, resulting in preventable exposures. Recent work has indicated tons of volatile organic compounds (VOC) may be released during a single CIPP project into the air. Chemicals released include hazardous air pollutants (HAP), carcinogens (CAR), endocrine disrupting chemicals (EDR), and other compounds with little toxicological information. While polymer composites have been manufactured for other applications for more than 50 years, little information exists about what chemicals and materials are used to manufacture CIPPs. As CIPP use has grown along with the number of bystander chemical exposures, concerns about the type, magnitude, and toxicity of chemical emissions from CIPP projects have markedly increased. To reduce the potential for human harm and environmental degradation, a better understanding of CIPP composite chemistry and manufacturing is needed. This dissertation aimed to elucidate the processes that control the composition of waste generated during plastic CIPP manufacture and ascertain how to modify the manufacturing practice to minimize impacts on composite integrity and emission toxicity. </p> <p>Chapter 1 focused on indoor VOC exposure simulation and styrene contamination/ decontamination to evaluate the risk of occupant exposure during CIPP installation. Styrene is a common monomer used in many CIPP resins and can be discharged into the air at CIPP worksites. A review of prior incidents revealed that CIPP waste (liquid, organic chemicals, etc.) could enter nearby buildings through multiple routes including windows, doors, or heating, ventilation, and air conditioning outdoor air intakes. When CIPP is manufactured inside a sanitary sewer pipe, waste can enter buildings through sewer laterals of nearby buildings and through foundation cracks. Study results showed that plumbing seal backflows in bathrooms caused by sewer repair work are hydraulically possible: the minimum pressure required to displace water in the plumbing trap was estimated to be 0.995 kPa and 8.85 kPa for a sink and toilet, separately. These pressures are much lower than those applied by the contractor during the sewer lining (up to 193.05 kPa). Based on the indoor exposure events, the dissipation potential of vapors, as well as the hydraulic calculations, indoor air chemical contamination and decontamination profiles were also examined. A mass balance model of chemical vapor dispersion was developed. Modeling results revealed that bathroom exhaust fan operation during a CIPP project can increase the indoor styrene concentration by enhancing the inflow of styrene-containing air from the sink and toilet. However, the styrene concentration decreased as air leaked across the bathroom door due to reduced suction in the plumbing. Based on incident reviews, chemical magnitudes, and modeling results it was concluded that CIPP waste discharge should be treated as hazardous material discharge, because of its threat to human health. Actions are needed to reduce waste generation and contain the waste, so it does not leave the worksite. Chapter 2 aimed to determine the manufacturing conditions that most influence chemical residual left in the thermally manufactured CIPP. Bench-scale testing of multiple styrene- and non-styrene composites revealed the manufacturing conditions (curing time, temperature, initiator loading) necessary to produce a high integrity composite while minimizing chemical residual and air emissions. Even though the VOC loading of the non-styrene resin (4 wt.%) was much less than that of styrene resin (39 wt.%), the non-styrene resin did contain HAP, EDR, CAR compounds including ethylbenzene, 2-ethylhexanoic acid, methacrylic acid, styrene, toluene, and <em>m</em>-xylene. Study results also revealed that by changing initiator loading a drastic reduction in the amount of styrene (-42 wt.%) and styrene oxide (-33 wt.%) residual left in the newly manufactured composite was achieved. Discoveries prompted a new hypothesis that this decreased residual also prompted a decreased amount of VOCs emitted into the air. The explanation is that this occurs because that a greater amount of the monomer styrene was incorporated into the resin during polymerization and not permitted to enter the air. Despite decades of polymer composite use, this study provides a new fundamental understanding of composite chemicals and techniques for reducing air pollutant emissions during plastic composite manufacture. In Chapter 3, the complexity of organic vapor chemicals found in the air during thermal heating of CIPP composites was explored and quantified. The emission rate of a popular monomer, styrene, was quantified from the materials before, during, and after composite manufacture. Scaling up bench-scale results, 1.9 to 14 US tons and 0.18 to 1.35 US tons of VOCs (0.05 to 0.36 US tons and 0.001 to 0.007 US tons of styrene) were estimated to be emitted during curing of styrene- and non-styrene CIPPs (i.e., typically 1-3 m of diameter pipes). By modifying standard air sampling methods, previously undetectable chemicals associated with CIPP manufacture were found in the styrene-laden air. These include acetophenone, benzaldehyde, phenol, and 1,3,5-trimethylbenzene. Results have immediate relevance to improved air monitoring for public and worker safety. Further, results can be used to examine the cumulative health and environmental risks of the CIPP pollutant mixtures. Chapter 4 focused on identifying CIPP technology/knowledge gaps and feedback from health officials from multiple state and federal agencies. Through this study, a public health workgroup was assembled to include disciplinary experts and 13 federal, state, and city health agencies and public health associations. Building on dialogue with U.S. health officials, the state of knowledge pertaining to CIPP chemical exposures, mitigation, and response actions was reviewed. Topics included 1) CIPP manufacturing process and waste; 2) sewers and buildings; 3) chemical exposure and health; 4) chemical risk assessment; 5) risk communication. This study helped establish relationships among federal, state, and city officials to improve public health response. Additionally, a primer for CIPP chemical fate and transport, as well as assisting in identifying and prioritizing public health information needs was developed. Identification and prioritization of current public health knowledge gaps and proposed practices for reducing exposures to the public and workers were reported. CIPP-related bench and research results throughout the dissertation can serve as an important basis for environmental policy and public health guidelines on the prevention and mitigation aspects of environmental and human health impacts resulting from CIPP manufacturing practices.</p>
66

Stagnation Impacts on Building Drinking Water Safety: The Pandemic and Microplastics

Kyungyeon Ra (13164972) 28 July 2022 (has links)
<p>  </p> <p>The pandemic prompted buildings globally to transition to low or no occupancy as social distancing to reduce the spread of Coronavirus Disease (COVID-19). This consequence prompted concerns about the chemical and microbiological safety of building drinking water due to stagnation. At the same time, microplastic (MP) pollution received increasing global attention due to their presence in the environment and recent discoveries within water distribution systems and at building faucets. MP sources have primarily been targeted as originating within the drinking water sources, but plastic plumbing components are less discussed and known to deteriorate into fragments and smaller pieces that reach faucets. Literature at the time of this work as sparse on stagnation impacts to drinking water quality and the fate of MPs in plumbing. In particular, health officials and building owners issued and received many differed guidance documents telling building owners do different things and no standard guideline was available to reduce the health risks caused by stagnant building drinking water. This dissertation  examined three different types of buildings during closed to low water use conditions and conducted bench-scale testing to explore the phenomena observed in the field. Chapter 1 describes water quality impacts during a 7 year old ‘green’ middle school as it transitioned from Summer (low water use) to Fall (normal use). Field experiments revealed that more than half of first draw water samples exceeded the copper (acute) health-based action limit during low water use. Copper concentration within the school increased as distance from building entry point increased. Chapter 2 and 3 describe report on chemical and microbiological water quality in buildings at a university buildings (Chapter 2), and elementary school (Chapter 3). Chapters 2 and 3 revealed that stagnation negatively impacted chemical and microbiological building water quality (cold and hot) but flushing was effective at remediating high concentration of heavy metals and <em>Legionella pneumophila</em> at most locations. But in large buildings, where building plumbing system was more complicated, flushing did not always result in improved water quality. Also discovered was that water quality again deteriorated even after whole building water system was flushed. It is important to understand own building systems to maintain water quality as each building complexity requires specific knowledge and solutions. Chapter 4 describes current knowledge associated with MPs in drinking water and results of bench scale experiments on MP fate and transport in building plumbing. This work identified that while MPs have been reported at building faucets, sampling details lacking from available studies often resulted in study results not being comparable across others. Based on the review of the issue, it was found that MPs have likely reached building faucets for decades but have received no characterization until recently. Bench-scale testing using two MPs, of different density, in copper and crosslinked polyethylene (PEX) pipes revealed size influenced the amount of MPs retained in a pipe. Research needs were identified to determine the fundamental factors that control MP fate in plumbing and their presence at building faucets. </p>
67

COCOON: CO2 & COVID OBSERVATION & NAVIGATION INNOVATIONS FOR GUIDANCE OUT OF THE CLIMATE AND COVID-19 CRISES

Clarice E Nelson (13956267) 13 October 2022 (has links)
<p>In this work, two overarching global crises are addressed with an engineering lens; the COVID-19 pandemic and climate change. Regarding the latter, an investigation is completed into the fluxes of CO2 in the wake of a simple wind farm for identification of potentially beneficial siting of Direct Capture of CO2. In this analysis, large-eddy simulations are used to quantify scalar entrainment in the turbines’ wake for several empirical CO2 profiles. In instances with positive or a combination of CO2 gradients, it was found that the concentration of CO2 increased in wake through downward mixing and entrainment. In a negative CO2 gradient, the opposite was found, with the wind turbine mixing away the increased surface<br> concentration and entraining down lower concentration air from above. These findings were used to make recommendations on scenarios in which wind turbines were beneficial to Direct Capture plants.<br> In addition, as part of the ongoing response to the COVID-19 pandemic, an innovative new technology was designed and constructed; a prototype photoacoustic spectrometer for the rapid detection of viruses. With the vision to become a viral "breathalyzer", the primary stage of development involved the creation of a prototype for proof-of-concept of viral detection using PAS. An extensive literature review was completed to determine optimal<br> design, with several distinct innovations integrated with the end-product in mind; such as a pure silicon resonator cell and a light-emitting diode source for low-cost, portable detection.<br> This was estimated to be of sufficient quality to detect single virions, as found through Finite Element Analysis.<br> Additionally, the validation of a proposed improvement on the medical mask, named Hy-Cu, is shown. Through various tests, Hy-Cu was found to have greater breathability than KN95 or surgical masks, as well as comparable efficiency in filtration of viral droplets.<br> Additionally, the novel inclusion of a diamond-like carbon-coated copper mesh layer resulted in viral inactivation of 99% after a period of 2 hours, allowing Hy-Cu to be safely reused without risk of transmission.<br> </p> <p> </p>
68

<b>Development of a Sustainability-Oriented Decision-Making Framework and Computational Tool for Energetic and Critical Material Evaluations</b>

Anusha Sivakumar (18777499) 06 June 2024 (has links)
<p dir="ltr">The modern world faces many challenges related to sustainability, including the ability to make high-level decisions using a sustainability-oriented framework, a matter of increasing importance to the United States military with respect to energetic materials (EMs). Although a few pieces - process flowsheet optimization, life cycle assessment (LCA) studies, and the use of optimization tools to identify an option - have been studied and utilized, there exists no systematic approach that combines all these pieces to create a framework that allows for holistic decision making. This is especially true with EMs, other key critical materials, and new methods of manufacture. An interconnected framework for LCA-based decision making is developed and a tool based on this framework created for use with novel materials. The interconnected framework and tool are utilized in two case studies related to the manufacture of RDX- a lab-scale, batch-mode configuration and a simplified continuous-mode configuration, to determine the optimal reaction temperature.</p>
69

​​USE OF ALGAE, CYANOBACTERIA, AND INDIGENOUS BACTERIA FOR THE SUSTAINABLE TREATMENT OF AQUACULTURE WASTEWATER​<b> </b>

Yolanys Nadir Aranda Vega (18433941) 27 April 2024 (has links)
<p dir="ltr">Aquaculture is a controlled aquatic farming sector and one of the most important human food sources. Fish farming is one of the predominant, fast-growing sectors that supply seafood products worldwide. Along with its benefits, aquaculture practices can discharge large quantities of nutrients into the environment through non-treated or poorly treated wastewater. This study aims to understand the nutrient composition of fish wastewater and the use of indigenous bacteria, cyanobacteria, and microalgae as an alternative biological treatment method. Wastewater samples from a local fish farming facility were collected and treated using six different species of cyanobacteria and microalgae include <i>Chroococcus</i><i> </i><i>minutus</i>, <i>Porphyridium</i><i> </i><i>cruentum</i>, <i>Chlorella vulgaris</i>, <i>Microcystis aeruginosa</i>, <i>Chlamydomonas </i><i>reinhardtii</i>, and <i>Fischerella</i><i> </i><i>muscicola</i>. All the samples were incubated for 21 days, and the following parameters were measured weekly: Chemical oxygen demand (COD), phosphate, total dissolved nitrogen, and dissolved inorganic nitrogen. In addition, dissolved organic nitrogen (DON), bioavailable DON (ABDON), and biodegradable DON (BDON) were calculated from the mass-balance equations. Colorimetric and digestive methods were used for the parameter measurements. The results showed that <i>C. </i><i>reinhardtii</i> reduced the soluble COD concentration by 74.6%, DON by 94.3%, and phosphorous by more than 99%. Moreover, <i>M. aeruginosa</i>, and <i>C. </i><i>minutus</i> significantly reduced inorganic nitrogen species (>99%). This alternative fish wastewater treatment method was explored to gain insight into fish wastewater nutrient composition and to create a sustainable alternative to conventional fish wastewater treatment methods.<b> </b></p>
70

<b>GREENHOUSE GAS EMISSIONS AND TIME-USE PATTERNS UNDER WORK FROM HOME: AN ACTIVITY-BASED INDIVIDUAL-LEVEL MODEL</b>

Hongyue Wu (19183129) 20 July 2024 (has links)
<p dir="ltr">Work from home (WFH) moves work into home life, reshaping the residential, workplace, and commuting activities, which further impacts greenhouse gas (GHG) emissions. Although existing work has explored individual time-use patterns under WFH, there is a lack of complete consideration of diverse activities, their durations and timelines, as well as the comparisons with traditional life at home and Work in Office (WIO). Also, existing studies have examined GHG emissions under WFH, while individual-level estimation using activity-specific data covering all major activities is lacking. In particular, limited studies explored individual time-use patterns and quantified activity-based emissions for the construction workforce. Therefore, this dissertation aims to (1) develop an activity-based individual-level model to estimate GHG emissions under WFH, (2) compare individual time-use patterns and activity-based GHG emissions between traditional life at home, WFH, and WIO to understand how WFH affects work, life, and the environment, especially for the construction workforce, and (3) propose activity-based decarbonization strategies to reduce GHG emissions. By employing the proposed model, high-resolution calculations of individual time-use patterns and activity-based emissions were achieved, revealing major activities’ durations and timing and highlighting major contributing activities to emissions under WFH. When shifting from traditional life at home to WFH, individuals reduced sleeping and leisure hours to incorporate work activity, resulting in an 11.34% reduction in GHG emissions. When comparing WFH to WIO, individuals reduced work and commuting time to include more cooking and leisure activities at home, mitigating GHG emissions by 29.11%. Demographic groups and climate regions showed different results mainly because of the varied work and household duties and the characteristics of regions. In addition, the construction workforce reduced GHG emissions by 13% and 46% under WFH compared to traditional life at home and WIO, respectively. Compared to the general public, the construction workforce had more reduction in work and commuting hours and associated emissions when shifting from WIO to WFH. The findings could help envision how WFH influences work, life, and the environment as well as assist both individuals and policymakers in achieving decarbonization and adopting low-carbon living during the work arrangement transition, which could contribute to sustainable development.</p>

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