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Sustainability of Residential Hot Water Infrastructure: Public Health, Environmental Impacts, and Consumer DriversBrazeau, Randi Hope 24 April 2012 (has links)
Residential water heating is linked to the primary source of waterborne disease outbreaks in the United States, and accounts for greater energy demand than the combined water/wastewater utility sector. To date, there has been little research that can guide decision-making with regards to water heater selection and operation to minimize energy costs and the likelihood of waterborne disease.
We have outlined three types of systems that currently dominate the marketplace: 1) a standard hot water tank with no hot water recirculation (STAND), 2) a hot water tank with hot water recirculation (RECIRC), and 3) an on-demand tankless hot water system with no hot water recirculation (DEMAND).
Not only did the standard system outperform the hot water recirculation system with respect to temperature profile during flushing, but STAND also operated with 32 – 36% more energy efficiency. Although RECIRC did in fact save some water at the tap, when factoring in the energy efficiency reductions and associated water demand, RECIRC actually consumed up to 7 gpd more and cost consumers more money. DEMAND operated with virtually 100% energy efficiency, but cannot be used in many circumstances dependent on scaling and incoming water temperature, and may require expensive upgrades to home electrical systems.
RECIRC had greater volumes at risk for pathogen growth when set at the lower end of accepted temperature ranges, and lower volumes at risk when set at the higher end when compared to STAND. RECIRC also tended to have much lower levels of disinfectant residual (40 -850%), 4-6 times as much hydrogen, and 3-20 times more sediment compared to standard tanks without recirculation. DEMAND had very small volumes of water at risk and relatively high levels of disinfection.
A comparison study of optimized RECIRC conditions was compared to the baseline modes of operation. Optimization increased energy efficiency 5.5 – 60%, could save consumers 5 – 140% and increased the disinfectant residual up to 560% higher disinfectant residual as compared to the baseline RECIRC system. STAND systems were still between 3 – 55% more energy efficient and could save consumers between $19 - $158 annual on water and electrical costs. Thus, in the context of “green” design, RECIRC systems provide a convenience to consumers in the form of nearly instant hot water, at a cost of higher capital, operating and overall energy costs. / Ph. D.
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Methylobacterium spp.: Emerging Opportunistic Premise Plumbing PathogensSzwetkowski, Kyle John 15 May 2017 (has links)
Opportunistic premise plumbing pathogens (OPPPs) are responsible for many infections linked to drinking water. The annual cost of disease caused by these waterborne pathogens is $850 million. Key characteristics of these opportunistic waterborne pathogens include: disinfectant- resistant, biofilm formation, thermal-tolerance, desiccation-resistant, growth in amoebae and growth in low oxygen conditions. Methylobacterium spp. have been recognized as an emerging OPPP, so the purpose of this study was to investigate these waterborne bacteria in more detail to determine whether they have all characteristics of OPPPs. Seven Methylobacterium spp. strains were studied to measure growth in laboratory broth medium and drinking water, measure hydrophobicity on surfaces found in household plumbing, measure adherence and biofilm formation to surfaces found in household plumbing and measure susceptibility to hot water heater temperatures. Methylobacterium spp. were found to aggregate in lab broth medium and drinking water, hydrophobic on different surfaces in household plumbing, adhere readily and form biofilm on different surfaces and thermal-tolerant to water heater temperatures. These results support and identify Methylobacterium spp. as opportunistic premise plumbing pathogens. / Master of Science
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Organic Carbon Generation Mechanisms in Main and Premise Distribution SystemsMartin, Amanda Kristine 02 November 2012 (has links)
Assimilable organic carbon (AOC) is a suspected contributor to growth of microbes, including pathogens, in plumbing systems. Two phases of research were completed to improve knowledge of AOC and other forms of organic carbon in premise plumbing. In the first phase, the AOC Standard Method 9217B was compared to a new luminescence-based AOC in terms of time, cost, convenience, and sources of error. The luminescence method was generally more accurate, as it better captured the peak growth of the test organisms. It was also less expensive and less time-consuming. A few approaches to improving the accuracy of the method and detect possible errors were also presented.
In the second phase of research, the possibility of AOC generation in premise plumbing was reviewed and then tested in experiments. It has been hypothesized that removal of AOC entering distribution systems might be a viable control strategy for opportunistic premise plumbing pathogens (OPPPs), but if AOC was generated in premise plumbing systems this approach would be undermined. Possible sources of AOC creation in premise plumbing, which is herein termed "distribution system derived biodegradable organic carbon (DSD-BDOC)," include: leaching of organic matter from cross linked polyethylene (PEX) pipes, autotrophic oxidation of H2 generated from metal corrosion (e.g. sacrificial magnesium anode rods and iron pipes), rendering of humic substances more biodegradable by sorption to oxides such as Fe(OH)3, and accumulation of AOC on filters and sediments. The potential for various plumbing and pipe materials to generate AOC was compared in controlled simulated water heater experiments. Under the worst-case condition, generation up to 645 µg C/L was observed. IT was not possible to directly confirm the biodegradability of the generated organic carbon, and there were generally no correlations between suspected generation of organic carbon and either heterotrophic plate counts (HPC) or of bacterial 16S rRNA genes. DSD-BDOC was also explored in a simulated distribution system with two disinfectant types (chlorine and chloramine) and three pipe materials (PVC, cement, and iron). TOC increased with water age, probably due to leaching of organics from PVC and possibly the aforementioned DSD-BDOC due to autotrophic reactions of nitrifiers and iron-related bacteria. As before, relationships between the higher levels of organic carbon and either HPC or 16S were not observed. / Master of Science
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Optimal Fixed-Premise Repairs of EL TBoxes: Extended VersionKriegel, Francesco 19 July 2022 (has links)
Reasoners can be used to derive implicit consequences from an ontology. Sometimes unwanted consequences are revealed, indicating errors or privacy-sensitive information, and the ontology needs to be appropriately repaired. The classical approach is to remove just enough axioms such that the unwanted consequences vanish. However, this
is often too rough since mere axiom deletion also erases many other consequences that might actually be desired. The goal should not be to remove a minimal number of axioms but to modify the ontology such that only a minimal number of consequences is removed, including the unwanted ones. Specifically, a repair should rather be logically entailed by the input ontology, instead of being a subset. To this end, we introduce a framework for computing fixed-premise repairs of $\mathcal{EL}$ TBoxes. In the first variant the conclusions must be generalizations of those in the input TBox, while in the second variant no such restriction is imposed. In both variants, every repair is entailed by an optimal one and, up to equivalence, the set of all optimal repairs can be computed in exponential time. A prototypical implementation is provided. In addition, we show new
complexity results regarding gentle repairs. / This is an extended version of an article accepted at the 45th German Conference on Artificial Intelligence (KI 2022).
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Spatial and Temporal Hydraulic Water Quality Models for Predicting Residential Building Water QualityMaria Arantxa Palmegiani (11798894) 07 December 2022 (has links)
<p>Significant seasonal changes in chemical and
microbiological water quality can occur in buildings at different fixture
locations due to temperature and time dependent reaction rates. Here, a series
of calibrated plumbing hydraulic-water quality models were developed for the
extensively monitored Retrofitted Net-zero Energy, Water & Waste (ReNEWW)
house in West Lafayette, Indiana USA. Knowledge gaps that inhibited higher
resolution water quality modeling were also identified. The eight new models
predict the absolute level of free chlorine, total trihalomethanes (TTHM), Cu (Copper),
Fe (Iron), Pb (lead), NO<sub>3</sub><sup> – </sup>(nitrate-nitrogen),
heterotrophic plate count (HPC), and <i>Legionella spp.</i> concentration at
each fixture for plumbing use, operational characteristics, and design layouts of
the plumbing system. Model development revealed that the carrying capacity to
describe Legionella spp. growth (and other organisms) under water usage and
plumbing design conditions is lacking in the literature. This information needed
for higher resolution modeling. Reducing building water use by 25% prompted
increased absolute concentrations of HPC and Legionella, each increasing by a
factor of about 10<sup>5</sup>. When the service line length was increased,
Legionella spp. concentrations increased by up to 10<sup>6 </sup>gene copies /L
in the Summer season. The proposed modeling framework can be used to support
better planning, design, analysis, and operational decision-making.</p>
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Investigating the impact on subjective satisfaction and learnability when adopting cloud in an SMELundberg, Elina, Gavefalk, Erica January 2019 (has links)
Cloud services and solutions have served as a shift in the computer industry and create new opportunities for users. Clouds have been described as easily usable and fluid in terms of expansion and contraction depending on the real-time needs. Although the cloud is promoted with several benefits, it is not always apparent for the users that this is the case. Understanding both the benefits and challenges that exist is substantial for a successful adoption to cloud. This master’s thesis is conducted in collaboration with Exsitec ABand aims to investigate how the adoption of the cloud service Microsoft Azure will affect the development process. Also, it aims to provide a best practice for potentially needed updated working procedures, in terms of satisfaction and learnability. The investigation was performed through interviews and the System Usability Scale, to assess how the end users experienced development in a cloud environment. The thesis revealed that the Azure portal has low overall usability, but that there also exists an inconsistency of that perception. Two major factors that contributed to the satisfaction and learnability was the lack of documentation and that the Azure portal was considered hard to master. The SUS score revealed that the mean value was below an acceptable level, and thus changes in the company’s working procedures need to be implemented. Internal documentation regarding how the company should use both cloud in general, as well as the portal in particular, are required in order to increase the learnability and subjective satisfaction.
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An investigation into a dramatic writing toolset for the creation of a new work of dramaPlayer, Glen J. January 2007 (has links)
In this exegesis I have attempted to formulate a primary toolset for dramatic writing that I can apply to create dramatic structure in plays, the chief example being my play Albatross (included herein). This toolset is contingent upon Aristotle's basic tenet of drama, that "tragedy is an imitation of an action" (2002: 10). This exegesis theorises that the work of modern writers on drama such as Spencer, Packard, Catron, Lamott, See, Hicks and many others, fundamentally accords with Aristotle on this point, such that the tools they espouse can collectively be considered a standard set for dramatic writing. Beyond this, my research has led me to believe that there is a primary subset of tools specific to creating dramatic structure. These tools, formulated from dramatic theory, best capture my own way of thinking about my writing practice. I divide them into two types: the first, tools of creation, comprise Theme and Values; Character and their Values; Characters and Action; Character Orchestration and Obstacles; and Event and Significant Change. The second, tools of evaluation, are Passivity; Stakes; and Premise. Together these eight tools have been responsible for creating dramatic structure in the play, Albatross.
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Poskytování ICT služeb v cloudu / Providing ICT services in the cloudNeumann, Jiří January 2011 (has links)
This thesis focuses on the ubiquitous cloud computing trend and particularly Software as a Service. The main goal is to specify all pros and cons of this concept for its customers and also cloud providers. The global perspective is then specified to Software as a Service and deployment of SaaS ERP products. The next goal is to define an appropriate method to analyze a company's needs prior to switching to the cloud. Furthermore, recommendations as to whether the cloud is better than an on-premise version should result from the previous analysis. Another aim is to form a process for successful switch to the cloud and ensure all important aspects of using cloud services are covered. Theoretical findings and recommendations are used in a practical example of SaaS ERP deployment. To reach all goals, a theoretical analysis of all available monograph and electronic sources, covering cloud computing and consultations with experts from the company; Algotech BSC, were used. The main added value is in the dual point of view on the topic, from customer's and provider's viewpoints with a more detailed focus on ERP. The author suggests the right procedure for switching to the cloud, guidance with calculating ROI, TCO and preparing all necessary contracts and agreements.
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Anledningar till att byta sitt affärssystem från ett traditionellt till ett molnbaserat / Reasons to change your ERP-system from a traditional to a cloud-basedLjungqvist, Emmy, Alakir, Johannes January 2021 (has links)
Idag tillämpar nästan alla verksamheter någon form av affärssystem och har kommit att bli ett betydande system för verksamheter. Under de senaste åren har även molnbaserade affärssystem vuxit fram vilket möjliggör verksamheter att använda hela eller delar av sitt affärssystem över internet istället för att behöva sköta all hantering av det fysiska lokalt. Det molnbaserade affärssystemet kan leda till flera fördelar för verksamheter då det kan öka flexibiliteten, skalbarheten och minska kostnader. Det blir bara fler verksamheter som väljer att gå över till det molnbaserade dock finns det vissa som arbetar kvar med det traditionella. Med utgångspunkt från detta är syftet med denna studie att se vilka aspekter det är som påverkar valet att gå från det traditionella affärssystemet till ett molnbaserat. För studien har tidigare litteratur studerats och intervjuer har genomförts för insamling av empiri. Tidigare forskning ligger till grund för det teoretiska ramverk som ligger till grund för de intervjufrågor som tagits fram. Det har intervjuats tre olika respondenter där alla har god förståelse kring ämnet och antingen arbetar i ett affärssystem eller arbetar som leverantör av dem. Det har främst ställts frågor kring de fem olika aspekter som vi anser varit betydelsefulla i denna studie. Men även frågor kring fördelar och nackdelar av de olika affärssystemen. Detta har krävts för att vi författare ska få en så god förståelse kring ämnet som möjligt. Utifrån det insamlade teoretiska material och empiri utfördes en analys där den tidigare litteraturen framfördes mot den insamlade empirin för att kunna få fram en helhetsbild över hur verksamheten förhåller sig kring ämnet och vilka aspekter det ser är betydande vid valet av affärssystem. Avslutningvis leder detta fram till en slutsats som presenteras med de allra mest väsentliga aspekter som har kommit fram i studien.
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Mellan himmel och jord,var befinner sig kunden? : En undersökning om kunders förtroende till On-Premise- och SaaS-systemEkman, Elvis, Anté, Sandra January 2024 (has links)
Implementering av affärssystem inom verksamheter kan ge många fördelar, exempelvis effektivisering och automatisering. Hur systemet levereras till kunden kan påverka förtroendet hos kunden. Förtroendet är viktigt för att bibehålla en god relation mellan kund och leverantör och för att kunden inte ska känna osäkerhet kring att implementera affärssystem. Affärssystem kan implementeras lokalt hos kunden On-Premise eller i molnet vilket tillhandahålls hos leverantören i form av Software as a Service (SaaS). Syftet för studien var att undersöka skillnader i kunders förtroende till On-Premise och SaaS-system och kartlägga faktorer vilket kan påverka förtroendet som testades med en modell för att mäta förtroende skapad av McKnight (2009). Utifrån modellen samt tidigare forskning inom området formulerades åtta hypoteser. Hypoteserna testades med hjälp av svar från en enkät som skickades ut till kunder av On-Premise och SaaS-system. Totalt blev det 72 svar som analyserades med hjälp av ett ANOVA test vilket slutligen bekräftade fyra av åtta hypoteser. Resultatet indikerade att det inte föreligger någon signifikant skillnad mellan de två urvalsgrupperna. Resultatet tyder på ett ökat förtroende för SaaS vilket tidigare inte innehaft ett lika högt förtroende, dessutom visar det på att digitaliseringen rör sig framåt med ett ökat förtroende för molntjänster trots de risker som tillkommer. Studiens resultat har potentiell relevans för leverantörer av både On-Premise- och SaaS-system genom att öka förståelsen för kundernas förtroende. Slutligen kan leverantörer anpassa system efter kundernas behov, förbättra säkerhet och kvalitet samt främja en gynnsam och långsiktig relation mellan leverantör och kund. / Implementation of business systems within organizations can provide many advantages, such as efficiency and automation. How the system is delivered to the customer can impact the trust of the customer. Trust is crucial for maintaining a good relationship between the customer and the supplier and for preventing the customer from feeling uncertainty about implementing business systems. Business systems can be implemented locally at the customer's site On-Premise or in the cloud, provided by the supplier in the form of Software as a Service (SaaS). The purpose of the study was to examine differences in customer trust in On-Premise and SaaS systems and to identify factors that may affect trust, tested with a model to measure trust created by McKnight (2009). Based on the model and previous research in the field, eight hypotheses were formulated. The hypotheses were tested using responses from a survey sent to customers of On-Premise and SaaS systems. In total, there were 72 responses that were analyzed using an ANOVA test, which ultimately confirmed four out of eight hypotheses. The results indicated that there is no significant difference between the two sample groups. The results suggest an increased trust in SaaS, which previously did not have as high trust. Additionally, it shows that digitization is progressing with increased trust in cloud services despite the associated risks. The study's results have potential relevance for providers of both On-Premise and SaaS systems by increasing understanding of customer trust. Ultimately, providers can tailor systems to customer needs, improve security and quality, and promote a favorable and long-term relationship between supplier and customer.
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