Stuttgart, Univ., Studienarb., 2004.

Several aesthetic, health, and plumbing quality issues can arise during new construction or renovation of premise plumbing. There has been little research done on many of these concerns and therefore few guidelines or regulations are in place to protect the health of the consumer or the integrity of the plumbing infrastructure. This work examines common construction practices including: 1) effect of residual construction debris, 2) shock chlorination of new plumbing lines, and 3) lead leaching propensity of new brass ball valves. During installation of plumbing systems, residual chemicals and debris including copper brass particles and flux, can be left in plumbing lines following construction and installation. This debris is considered undesirable from health, aesthetic, and corrosion perspectives. Soldering flux is of particular concern due to its corrosive nature. Experiments were conducted to determine the effects of residual solder flux, PVC glue, and metallic debris and to quantify flushing velocities and durations to effectively remove them from a new plumbing system. A flushing velocity of 3 fps for 30 minutes is needed to remove water soluble flux, while petroleum based flux still persists after extensive flushing at 7 fps. Currently a practice known as shock chlorination, whereby super chlorinated water is used for disinfection, is used in water mains after installation or repair as specified in the ANSI/AWWA C651 Standard. This practice is now starting to be required by some building codes in premise plumbing for new construction. Water mains are typically made of concrete where as premise plumbing using copper or PVC piping. Copper pipe is susceptible to attack by high chlorine, and this reaction will also remove the chlorine residual. There is concern about potential damage to copper from free chlorine and that in some systems targeted residuals of chlorine might not be obtained. Experiments did not detect serious damage to copper pipe, but in some waters it was not possible to meet targeted residual levels of chlorine. The addition of orthophosphate corrosion inhibitor or adjustment of pH can sometimes reduce the chlorine decay rate. Extremely high and persistent lead leaching in a brand new building at the University of North Carolina (UNC) traced to leaded bronze ball valves, prompted an extensive forensic evaluation how existing standards (National Sanitation Foundation Section 8) could allow for installation of products that could create a human health hazard due to high lead. Diffusion of lead from within the device to water in the pipe, high velocity, microbial activity and other factors caused more leaching in practice than would be expected based on NSF testing and normalization factors applied to certify a valve as safe. Moreover, use of flux during soldering of joints, increased lead leaching by orders of magnitude relative to results of NSF testing without flux. / Master of Science

The ban on lead plumbing materials in the Safe Drinking Water Act (1986) and the EPA Lead and Copper Rule (1991) have successfully reduced lead contamination of potable water supplies. The success of these regulations gave rise to a belief that serious lead contamination was an important past problem that had been solved, and that additional fundamental research was therefore unnecessary. This work carefully re-examined the lead contamination issue from the perspective of 1) new regulations causing a shift from chlorine to chloramine disinfectant, 2) assumptions guiding sampling strategies, 3) existing performance standards for brass, and 4) galvanically driven corrosion of lead bearing plumbing materials. The results were instrumental in uncovering and understanding a serious problem with lead contamination in Washington, D.C. A critical reading of the literature indicates that chloramines can accelerate corrosion of lead bearing materials and increase lead contamination of water. When a new sampling protocol was conceived and used in Washington homes to assess the nature of the problem, hazardous levels of lead were found to be present in some drinking water samples. Contrary to the conventional wisdom, lead was not always highest in first draw samples, but often increased with flushing. This has several important implications for monitoring and public health. For instance, well-intentioned public education materials were causing consumers to drink water containing very high levels of lead in some circumstances. Laboratory and field-testing proved that chloramines were causing serious lead corrosion problems. That testing also discovered that, unbeknownst to scientists and utilities, free chlorine itself can act as a corrosion inhibitor, reducing lead solubility and contamination of water. The net result is that changing disinfectant from free chlorine to chloramine can sometimes trigger serious lead contamination of water. While the worst problems with lead in Washington, D.C. came from the lead services, significant levels of lead were occasionally sampled from homes with solders or brass as the lead source. This prompted re-evaluation of the ANSI/NSF 61, Section 8 standard, which is relied on to protect public health from in-line brass plumbing devices that might leach excessive lead to potable water. In-depth study of the standard revealed serious flaws arising from use of a phosphate buffer in the test waters and a failure to control carbonate dissolution from the atmosphere. Due to these deficiencies, small devices made of pure lead could actually pass the performance test. The public therefore has no assurance that devices passing NSF Section 8 testing are safe and reforms to the standard are obviously needed. Other problems arise from connecting copper pipe to lead bearing plumbing in practice. The copper is cathodic and dramatically accelerates corrosion of the lead anode via a galvanic current. Corrosion and hydrolysis of released Pb²⁺ can lower pH near the surface of the lead and increase its solubility. A similar galvanic effect can arise from cupric ions present in the water via deposition corrosion mechanism. In cases where part of a lead service line is replaced by copper pipe, the galvanic corrosion effect can create a serious long-term problem with lead contamination. Such partial lead service line replacements are occurring in many US cities and the practice should be stopped. Lead contamination of potable water is not only a problem of the past but also of the present. While additional research is necessary before regulators, utilities and homeowners can anticipate and mitigate such problems with confidence, this work provides sound fundamental basis for future progress. / Master of Science

Ingeniero Civil / El presente trabajo de título busca encontrar los valores de las razones de fluencia, Ry, y rotura, Rt, de la norma ANSI/AISC 341-10 Seismic Provisions for Structural Steel Buildings para perfiles de acero que se utilizan en Chile. Para el análisis se hace una investigación y recopilación de información de distintas fuentes chilenas que estén dispuestas a facilitar datos y que tengan relación con el ensaye de elementos de acero en sus distintos grados (por ejemplo: IDIEM, DICTUC, CESMEC, ICHA), o en su defecto con empresas que tengan relación con el rubro del acero estructural y que tengan dentro de sus políticas el tener el respaldo de los ensayos de las planchas y/o perfiles con que trabajan (por ejemplo: ARRIGONI, EDYCE, CAP). Con ello se hizo un análisis estadístico que, acorde con la metodología de cálculo de los coeficientes de la Norma AISC, tendrá como objetivo encontrar el valor de resistencia esperada tanto de fluencia como de rotura de los tipos de acero en cuestión. Así posteriormente, se planteó el valor nominal de Rt y Ry que corresponde a cada grado de acero utilizado en Chile. Lo medular se concentra en un análisis comparativo entre los valores para el acero norteamericano y el utilizado en Chile, con el motivo de discernir si es necesario el que los nuevos valores encontrados se apliquen en el medio nacional o si los estadounidenses son adecuados para las condiciones de nuestro país. Esto se hace teniendo en consideración distintos factores que pudieran afectar la calidad del acero, como el país de origen de las planchas y/o perfiles de acero y año en que fue introducido al mercado (desde 2006 a la fecha), además del total de los datos recopilados. Los resultados obtenidos indican una concordancia, en magnitud, entre las tensiones de fluencia y rotura esperadas observadas en el mercado local con los que se pueden obtener de la norma ANSI/AISC 341-10. Para el caso de planchas de acero ASTM A36 el Ry obtenido supera en un 3% al recomendado y el Rt está 1,6% bajo el normado. Por otro lado para las planchas de acero A572 Gr50 el valor de Ry supera en un 12,7% el valor propuesto por la AISC, mientras que el de Rt está por sobre el de la norma en un 7%. Los valores obtenidos para los perfiles de acero laminados en caliente de calidad A270ES son Ry=1,25 y Rt=1,15. Para perfiles laminados de calidad A345ES los coeficientes son Ry=1,26 y Rt=1,14. Estos valores son únicos y no tienen comparación con la Norma ANSI/AISC 341-10 dado que son de fabricación y nomenclatura nacional.

Arborists are exposed to many occupational hazards and experience more than three times the overall fatality rate of all U.S. workers. Investigations into fatal incidents lead to a better understanding of industry dangers. However, this knowledge does not extend to how tree workers operate when an injury or fatality does not occur. Current research regarding fatal and nonfatal injuries does not include the accreditation status of the company at which the worker was employed, nor whether certified arborists were on staff. Given the highly skilled nature of the work involved, certification and accreditation might ensure a minimum level of demonstrated safety practices. This study aimed to 1. Determine whether certification and accreditation in the tree care industry are associated with safer workplace behavior, and 2. Identify safety practices that tree workers commonly violate. Tree care companies in southern New England were divided into three categories: accredited, non-accredited with certified arborists on staff, and non-accredited with no certified arborists on staff. A stratified random sample of 63 companies was evaluated in the field by direct observation, assessing workers’ adherence to the industry’s safety standard, the American National Standards for Arboricultural Operations (ANSI Z133.1-2006). Analysis indicated that, overall, accredited companies and those with certified arborists on staff complied with the Z133.1 Standard more than those without. Although these companies were more compliant, few significant differences emerged, and low overall compliance was found for personal protective equipment and chainsaw and chipper safety. There were low levels of compliance across all types of companies with the basic aspects of safety, including feeding the chipper from the curbside, not drop-starting a chainsaw, and using head, eye, and hearing protection. Implications of findings include possible considerations for improvements on accreditation and certification processes. Further findings address aspects of the Z133.1 Safety Standard that are currently unclear.

Growing concern over adverse health effects from low level lead exposure motivated reassessment of lead occurrence in drinking water, from the perspective of 1) possibly eliminating lead from new brass materials, and 2) performance testing of existing products. During the course of this thesis work, it was discovered that several cases of childhood lead poisoning in North Carolina, South Carolina and Washington D.C. occurred from contaminated potable water. That disconcerting finding prompted additional work into 3) deficiencies in existing lead testing of drinking water samples, and 4) impacts of water treatment steps on lead leaching. Meters, components, and fittings manufactured from non-leaded brass (< 0.25 percent lead content) are increasingly specified for use in water distribution systems and premise plumbing, in response to California's Proposition 65 and the proposed Lead Free Drinking Water Act. An in-depth review of the available literature revealed that non-leaded brass releases minimal amounts of lead and other contaminants of concern to drinking water. There is legitimate concern about the corrosion resistance and longevity of these non-leaded alloys in the range of waters that will be encountered in practice. Nonetheless, when the potential impacts to manufacturers, utilities and consumers are considered, non-leaded brasses appear to be attractive albeit at slightly higher cost. For existing leaded brass products, concerns have been raised over potential limitations of performance standards used to certify the products as "safe" in the marketplace. The ANSI/NSF 61 Section 9 test is the industry standard, and its protocol is critically evaluated from the perspective of the leaching solution chemistry. Testing indicated that the protocol water is reasonably representative of a typical water supply. However, some lower pH and lower alkalinity waters can be much more aggressive than the existing section 9 water, and for potable water with these characteristics, problems with higher than desired lead leaching may occur. It may be desirable to tighten the standard's pass/fail lead criterion in order to account for this problem in practice. Several cases of childhood lead poisoning from water have been recently encountered, which prompted environmental assessments. It was visually obvious that some of the lead particles ingested by these children, present in water from the tap, were not completely dissolving in the standard method with weak acid recommended by the US EPA. A laboratory investigation proved that up to 80% particulate lead in water samples could be "missed" by the standard protocol. Unfortunately, tests with simulated gastric fluid revealed that much of this particulate lead would be bioavailable in the presence of chloride, warmer temperatures and lower pH inside the human stomach. It is recommended that water utilities be alert to this possible problem and that environmental assessments of lead poisoned children use stronger digestions to detect lead in water. Several of the lead poisoning instances occurred after the utility changed both disinfectant chemicals (from chlorine to chloramine) and coagulant types. Although authorities initially thought chloramine was the cause based on experiences in Washington D.C., bench scale studies in this work proved that a change in coagulant from aluminum sulfate to either ferric chloride or polyaluminum chloride was in fact the main reason of the lead spikes. The reduction in sulfate and increase in chloride increased the chloride to sulfate mass ratio of the water supply. A higher chloride to sulfate mass ratio triggered much higher (2.3-40 times more) lead leaching from solder connected to copper pipe. The adverse effects of the increase in the ratio could not be eliminated by adding a corrosion inhibitor. / Master of Science

Made available in DSpace on 2014-06-11T19:22:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-18Bitstream added on 2014-06-13T19:08:07Z : No. of bitstreams: 1 fabianespinoza_rg_me_ilha.pdf: 869619 bytes, checksum: 3c82572569bc2349669cb3765fb65c95 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Ensino Pesquisa e Extensão de Ilha Solteira (FEPISA) / Neste trabalho apresenta-se uma metodologia para obter um ambiente interativo de simulação com ferramentas que permitam fazer análises de sistemas de proteção como estudos de coordenação e analises pós falta. As ferramentas estão baseadas no programa de simulação de transitórios eletro- magnéticos EMTP/ATP e na linguagem de programação ANSI C, sobre a plataforma de software livre GNU/Linux. Esta metodologia pode ser implementada, da mesma forma, em qualquer plataforma Windows sobre a qual possa funcionar o EMTP/ATP e o pacote ATP/MingW. Assim, implementou- se um relé de distância numérico através de modelos externos (“foreign models”). Ilustra-se também como usar arquivos no formato COMTRADE na análise com EMTP/ATP. Dessa forma foi possível analisar o comportamento do relé implementado tendo como entradas os sinais de tensões e correntes correspondentes aos eventos reais. Os sinais de disparo, assim como os demais componentes do relé, foram testados usando um sistema teste de referência do Power System Relaying Committee da PES-IEEE e os sinais de faltas reais do Sistema Elétrico Interligado da Colômbia. Por fim, foi feito um estudo de coordenação. Os resultados são apresentados e discutidos. A metodologia proposta pode ser usada para desenvolver qualquer componente ou elemento de controle dentro de um sistema elétrico, onde haja a necessidade de usar o EMTP/ATP para simular condições específicas de operação do sistema elétrico, complementando a simplicidade da linguagem MODELS com a portabilidade e potencialidade da linguagem C / This work presents the methodology to obtain an environment of interactive simulation with tools to perform analysis of protection systems, coordination studies and analysis post fault. These tools are based on the program for electromagnetic transients EMTP/ATP and in ANSI C programming language used in the free GNU/Linux software platform. The same methodology can be followed to be used on any Windows Operating System that can run EMTP/ATP and the package ATP/MingW. Then, for this, a numerical distance relay was implemented by means of foreign models using C programming language. It also shows how to use COMTRADE files in analysis with EMTP / ATP. Thus it was possible to analyze the behavior of the implemented relay with voltage and current signals of real events as inputs. The trip signals, like the other components of the relay, were tested using a testing reference system of Power System Relaying Committee of PES-IEEE and the signals of real faults of Inter- connected Electric System of Colombia. Finally, a coordination study was made. The results are presented and discussed. This methodology could also be used to develop any component or control element within an electrical system that one may need for a particular use; therefore, compensating the simplicity of the language MODELS with the flexibility and portability of C programming language

For organisations to stay competitive, continuous improvements and development are needed.Organisations handling complex services, structured in projects, find difficulties in understanding the project performance. Understanding the project performance is important in order to achieve the ability to implement improvements and development activities in projects. Furthermore, project performance needs to be understandable for the whole organisation in order to be able to prioritize. There are several applicable methods available for handling the evaluation of performance. One method is Earned Value Management, EVM, which incorporates project scope, schedule and cost parameters in order to create project control.The purpose of this study is to investigate how EVM could be implemented for evaluating performance in projects handling repair and maintenance based on the EVM standard ANSI/EIA-748. The purpose is also to identify needed adaptations in the projects to make it possible to implement EVM. The EVM standard contains important steps and activities needed in order to be able to aggregate values and evaluate performance.The result of this study presents adaptations needed for EVM implementation based on the EVM standard ANSI/EIA-748. The study concludes that some structural and managerial changes need to be done before EVM can be implemented. The organisation needs to formulate common guidelines for structuring work and organisations, as well as formulate and define common reporting structures for documentation and reporting. In addition, the way of handling planning, and budgeting need to be reviewed and customised. The organisation also needs to continuously work with the knowledge and understanding about the importance of the business and the evaluation, to create a successful EVM implementation and a sustainable business. / För att organisationer ska kunna vara konkurrenskraftiga krävs kontinuerlig förbättring och utveckling. Organisationer som är organiserade i projekt och som hanterar komplexa tjänster, finner svårigheter i att förstå projektets prestation. Detta är viktigt för att kunna genomföra förbättringar och utvecklingsaktiviteter. Dessutom måste projektets prestation kunna förstås av hela organisationen för att skapa möjligheter att prioritera. Det finns flera tillgängliga metoder som kan användas för att hantera detta. En metod är Earned Value Management (EVM), som innehåller projektomfång, tidsplan och kostnadsparametrar för att skapa projektstyrning.Syftet med denna studie är att undersöka hur EVM kan implementeras för att utvärdera prestanda i projekt som hanterar service och underhåll, baserat på EVM-standarden ANSI/ EIA-748. Syftet är också att identifiera nödvändiga anpassningar i projekten, för att göra det möjligt att implementera EVM. EVM-standarden innehåller viktiga steg och aktiviteter som krävs för att kunna aggregera värden och utvärdera prestanda.Resultatet av denna studie presenterar anpassningar som behövs för implementering av EVM, baserat på EVM-standarden ANSI / EIA-748. Studien drar slutsatsen att vissa strukturella och ledande förändringar måste göras innan EVM kan implementeras. Organisationen måste formulera gemensamma riktlinjer för strukturering av arbete och organisationer, samt formulera och definiera gemensamma strukturer för dokumentation och rapportering. Dessutom måste sättet att hantera planering och budgetering granskas och anpassas. Organisationen måste också kontinuerligt arbeta med kunskap och förståelse om verksamhetens betydelse och utvärdering, för att skapa en framgångsrik EVM-implementering och en hållbar verksamhet.

Organisationer med komplexa projekt som sträcker sig över ett flertal år finner svårigheter att förhålla sig till projektens fördefinierade parametrar tid, kostnad och omfattning. Skenande kostnader och förseningar är vanligt förekommande i dessa typer av projekt, då projekten omfattar ett samspel av ett flertal aktiviteter och där projektets omfattning ofta förändras. Det finns metoder som verksamheter kan tillämpa för att kontrollera ovannämnda parametrar och i ett tidigt skede kunna identifiera när någon av parametrar tenderar att överskridas. En metod som styrker prestationsmätningar är Earned Value Mangament, EVM. Syftet med studien var att identifiera vart organisationer brister gentemot branschstandarden inom EVM, ANSI/EIA-748. Standarden innehåller viktiga steg för att kunna utföra en korrekt prestationsmätning tillsammans med teorin från Earned Value Management. Resultat studien presentera indikerar på att organisationer måste skapa tydliga riktlinjer hur ANSI/EIA-748 skall tillämpas. Till exempel att alla bryter ner arbetet och fördelar sina budgetar på samma sätt. Studiens resultat antyder också att Rolling Wave är ett lämpligt verktyg för komplexa och långa projekt. Av den anledningen att projektledare inte planerar för mycket i onödan eftersom projektets omfattning ständigt förändras.

Master of Science / Architectural Engineering and Construction Science / Russell J. Murdock / The purpose of this study is to identify and explore relationships between the building industry, building energy usage, and how both the industry and the energy usage correspond to greenhouse gas (GHG) emissions in the United States. Building energy codes seek to reduce energy usage and, subsequently, GHG emissions. This study specifically seeks to determine the impact that most current U.S. building energy codes could have on national GHG emissions if widespread adoption and enforcement of those codes were a reality. The report initially presents necessary background information about GHG emissions is first discussed. This establishes the current state of global GHG emissions, the position of the U.S. within the global scale, and what portion of the contribution can be attributed to the building industry. The report also describes the current issues and benefits of building energy codes. An overview of building energy codes evaluation is included, with explanation of the energy analysis used to determine the effectiveness of new building energy codes. In order to determine how to improve the building energy code system, an analysis of ANSI/ASHRAE/IES Standard 90.1-2013 (equivalent to 2015 IECC, the most recent standard available) is conducted to reveal unrealized GHG emission reductions that are expected with adoption and compliance to the newest code. Standard 90.1-2013 is analyzed due to the national popularity of the code relative to other building energy codes. This analysis includes compilation of energy usage intensity, square footage, and current code adoption data throughout the United States. Results showed that the excess GHG emission savings from enhanced adoption and compliance was not significant on a national scale. However, in terms of GHG emissions currently saved by building energy codes, the extra savings becomes more significant, proving that increased adoption and compliance is a worthwhile pursuit. Recommendations are then made for how to increase adoption and compliance. This information will give policymakers improved understanding of the current state of the industry when crafting laws regarding GHG emissions and building energy codes. Furthermore, findings from this study could benefit specific states that are attempting to lower GHG emissions.