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A Comparison of Risk Assessment Models for Pipe Replacement and Rehabilitation in a Water Distribution SystemNemeth, Lyle John 01 June 2016 (has links)
A water distribution system is composed of thousands of pipes of varying materials, sizes, and ages. These pipes experience physical, environmental, and operational factors that cause deterioration and ultimately lead to their failure. Pipe deterioration results in increased break rates, decreased hydraulic capacity, and adverse effects on water quality. Pipe failures result in economic losses to the governing municipality due to loss of service, cost of pipe repair/replacement, damage incurred due to flooding, and disruptions to normal business operations. Inspecting the entire water distribution system for deterioration is difficult and economically unfeasible; therefore, it benefits municipalities to utilize a risk assessment model to identify the most critical components of the system and develop an effective rehabilitation or replacement schedule.
This study compared two risk assessment models, a statistically complex model and a simplified model. Based on the physical, environmental, and operational conditions of each pipe, these models estimate the probability of failure, quantify the consequences of a failure, and ultimately determine the risk of failure of a pipe. The models differ in their calculation of the probability of failure. The statistically complex model calculates the probability of failure based on pipe material, diameter, length, internal pressure, land use, and age. The simplified model only accounts for pipe material and age in its calculation of probability of failure. Consequences of a pipe failure include the cost to replace the pipe, service interruption, traffic impact, and customer criticality impact. The risk of failure of a pipe is determined as the combination of the probability of failure and the consequences of a failure. Based on the risk of failure of each pipe within the water distribution system, a ranking system is developed, which identifies the pipes with the most critical risk. Utilization of this ranking system allows municipalities to effectively allocate funds for rehabilitation.
This study analyzed the 628-pipe water distribution system in the City of Buellton, California. Four analyses were completed on the system, an original analysis and three sensitivity analyses. The sensitivity analyses displayed the worst-case scenarios for the water distribution system for each assumed variable. The results of the four analyses are provided below.
Risk Analysis
Simplified Model
Complex Model
Original Analysis
All pipes were low risk
All pipes were low risk
Sensitivity Analysis: Older Pipe Age
Identified 2 medium risk pipes
Identified 2 medium risk pipes
Sensitivity Analysis: Lower Anticipated Service Life
Identified 2 medium risk pipes
Identified 9 high risk pipes and 283 medium risk pipes
Sensitivity Analysis: Older Pipe Age and Lower Anticipated Service Life
Identified 1 high risk pipe and 330 medium risk pipes
Identified 111 critical risk pipes, 149 high risk pipes, and 137 medium risk pipes
Although the results appeared similar in the original analysis, it was clear that the statistically complex model incorporated additional deterioration factors into its analysis, which increased the probability of failure and ultimately the risk of failure of each pipe. With sufficient data, it is recommended that the complex model be utilized to more accurately account for the factors that cause pipe failures.
This study proved that a risk assessment model is effective in identifying critical components and developing a pipe maintenance schedule. Utilization of a risk assessment model will allow municipalities to effectively allocate funds and optimize their water distribution system.
Keywords: Water Distribution System/Network, Risk of Failure, Monte Carlo Simulation, Normal Random Variable, Conditional Assessment, Sensitivity Analysis.
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Hodnocení investičního záměru / The Evaluation of the the Investments ProjectDaňhel, Marek January 2012 (has links)
The project elaborated within the follow-up master´ s study programme of the M-STM Manufacturing Technology and Management in Industry branch presents an evaluation of a company investment project and recommendations whether to realize the intended investment. The diploma work sets forth an overview of theories in the field of company investment activities, company analysis, details of the investment project and its evaluation. Technical economic analysis of a part fabrication with utilization of new machine equipment, together with conclusions related to the proposed technology, form a part of the project.
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Počítačové simulace dvouosých tahových zkoušek měkkých biologických tkání / Computer simulations of biaxial tension tests of soft biological tissuesSlažanský, Martin January 2014 (has links)
Within the master thesis a computational model of biaxial tension test of soft biological tissues was developed. The tested specimen can be attached using clamps or hooks. The number and the size of clamps and hooks have a significant impact on the distribution of stress and strain in the centre of the specimen, where deformation is measured. Using the developed computational model, a sensitivity analysis of number and size of clamps and hooks and a sensitivity analysis of placement of clamps was elaborated. The number and size of clamps and hooks were optimized in such a way that the material’s parameters obtained by the tension test correspond to the utmost to the actual parameters of the material. By analyzing the placement of clamps, the influence of selected deviations on the outcome of the tension test was determined. Finally, a plan of the next course of action has been proposed.
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Energimodellering av ett flerbostadshus - en parameterstudie : Granskning av energianvändning och termisk komfort / Energy simulation of a multi-apartment building - a parameter analysis : Evaluation of energy performance and thermal comfortSaidzadeh, Millad January 2013 (has links)
Idag står bostads- och servicesektorn för närmare 40 % av Sveriges totala slutliga energianvändning. Flerbostadshus utgör ca 30 % av den energianvändningen. Därför är det viktigt att lokalisera energiparametrar och redovisa dess betydelse för energianvändningen. Samtidigt bör relationen mellan energianvändning och inomhusklimat analyseras, så att inte förändringar i energin medför till försämringar för inomhusklimatet. Baserat på identifiering hos energisparpotentialen hos parametrar, parameterbeteende och parameterkänslighet för energianvändning har i studien ett antal parametrar undersökts för ett flerbostadshus. Även parametrarnas betydelse för det termiska klimatet har utifrån de parametrar som visat sig ha störst energisparpotential studerats. Studien är tänkt att komma till nytta för presentation av energisparpotentialer och beaktande hos indataparametrar vid energiberäkningar, samt öka förståelsen för hur termiska komforten påverkas av olika parametrar. En referensbyggnad har modellerats i programmet IDA ICE 4.5 och typisk spridningen för olika parametrar för byggnader från år 1970 till nutid har varierats och jämförts med ett referensfall. För det termiska klimatet har kriterier enligt certifieringsprogrammet Miljöbyggnad utnyttjats. Resultatet visar att ventilationssystem har stor energisparpotential. Vid en övergång från F-system till FTX-system görs betydande energibesparing, samtidigt som det sker en förbättring av den termiska komforten. Inomhustemperaturen har visats sig vara den känsligaste parametern vid beräkning av energianvändning. För den termiska komforten är fönsters g-värde och inomhustemperatur viktiga parametrar att beakta. Resultatet av energi- och komfortsimuleringarna visar också på en tydlig korrelation mellan energianvändning och termisk komfort. / Building stock consumes 40 % of total energy usage in Sweden, dwellings contribute almost 30% of the proportion. With an interest on the parametric analysis and its corresponding energy saving potentials, the investigation on the sensitivity of selected building parameters in a typical Swedish slab house is performed in the study. Based on the identification to the behavior of target sensitive parameters, the upgrading potential of thermal comforts is comparably analyzed with respect to approach the optimization design of further retrofitting scenario and uncertainty guidelines. A slab house built after 1970 is selected as the represented case building with a detailed typology introduction. In the study, IDA ICE 4.5 is applied to perform both the energy simulation and thermal comfort estimation. Based on the local screening analysis and the setting of criterion system, the ranking of the target parameters is rated systematically. The study is meant to be useful for the presentation of energy saving potentials and consideration of input parameters on energy calculations, and increase understanding of how thermal comfort is affected by various parameters. The results show that accomplished with the transformation of F-system to FTX-system, the applicable ventilation system efficiency shows the largest energy saving potential and improved thermal comfort, and the indoor temperature shows the largest sensitivity to the total energy profile. Comparably, along with the indoor temperature, the performance of glazing system in terms of the g-value is recognized as the parameters with the highest consideration. Based on the sensitivity analysis, the correlation between the energy savings and thermal comfort upgrading is verified, which indicate the possibility of providing optimal design scenario for both architectural error guidelines and further building retrofitting.
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Life cycle assessment and resource management options for bio-ethanol production from cane molasses in IndonesiaKummamuru Venkata, Bharadwaj January 2013 (has links)
The intent of this thesis is to analyse the sustainability of producing bio-ethanol from cane molasses in Indonesia and its potential to replace gasoline in the transportation sector. A field trip was conducted in East Java, Indonesia, and data was gathered for analysis. Life cycle assessment (LCA) was performed to analyse the net emissions and energy consumption in the process chain. The greenhouse gas (GHG) emissions of the life cycle are 17.45 gCO2e per MJ of ethanol produced. In comparison to gasoline, this results in a 78% reduction in GHG emissions in the complete process chain. Net Energy Value (NEV) and Net Renewable Energy Value (NREV) were 6.65 MJ/l and 24 MJ/l. Energy yield ratio (ER) was 9.43 MJ of ethanol per MJ of fossil energy consumed in the process. Economic allocation was chosen for allocating resources between sugar and molasses. Sensitivity analysis of various parameters was performed. The emissions and energy values are highly sensitive to sugarcane yield, ethanol yield and the price of molasses. Alternative management options were considered for optimizing the life cycle. Utilizing ethanol from all the mills in Indonesia has a potential to replace 2.3% of all motor gasoline imports. This translates in import savings of 2.3 trillion IDR per year. Use of anaerobic digestion or oxidation ponds for waste water treatment is unviable due to high costs and issues with gas leakage. Utilizing 15% of cane trash in the mill can enable grid independency. Environmental impacts due to land use change (Direct & Indirect) can be crucial in overall GHG calculations. Governmental regulation is necessary to remove current economic hurdles to aid a smoother transition towards bioethanol production and utilization. / Harnessing agricultural feedstock and residues for bioethanol production - towards a sustainable biofuel strategy in Indonesia
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The effect of increasing train lengths on the fatigue lifespan of a bridge.Monballiu, Franck, Schils, Wouter January 2016 (has links)
More and more pressure is exerted on railway infrastructure due to an increasing transportation demand and population density. Instead of expanding the net, a possible solution could lie in the enlargement of the capacity by operating longer trains rather than more short ones. However, close attention has to be paid to the behaviour and the lifetime of the infrastructure under these changed loads. In special bridges are delicate aspects in this matter. In the current thesis the simply supported Banafjäl bridge located on the Bothnia Line in the North of Sweden is studied more in detail with regards to this aspect. It is a high-speed composite railway bridge with a span of 42 m. A detailed 3D finite element (FE) model is made available. However in order to make reliable predictions about the behaviour under increasing train length loads, it had to be further improved. Different methods of calibrating measured response data to an existing FE model, finite element model updating (FEMU), are available and a detailed overview is given at the beginning of this thesis. Next a sensitivity analysis was performed to select the material parameters which are most influential for the result and will be updated. In the following, FEMU is carried out by means of two iterative updating methods, genetic and gradient-based optimization, after which also a combination of these two is implemented. Two objective functions are chosen and it is shown that all methods converge to a global optimal solution. After adjusting the initial model with the updated parameter values, a fatigue analysis on this updated model is carried out for high-speed trains of multiple lengthsby means of the Palmgren-Miner rule. The fatigue is found to increase with increasing train length and in particular when the speed approaches resonance speed. By extension an operating chart is created to indicate the maximum amount of train passages per day in function of speed and train length for a type 4 fatigue train. Furthermore, damping has been shown to have a positive effect on the fatigue, the larger this effect for shorter trains. The static behaviour has been proven not to be a problem and so will solely the weight of trains induce little to no fatigue problems in this particular bridge.
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Data uncertinties in material flow analysis.Local case study and literature survey.Danius, Lena January 2002 (has links)
The aim of this thesis is to discuss and analyse the influenceof data uncertainties with regard to the reliability of materialflow analysis (MFA) studies. MFA, as a part of environmentalsystems analysis, is a method belonging to the research field ofindustrial ecology and more specifically industrial metabolism.As such, the method strives at giving a holistic view of thecomplex world we live in, in order to reduce negativeenvironmental impact. Among other things, MFA studies have beenproposed to be useful for priority setting and following up inmunicipalities. Serving as a starting point is a local case study of flows ofnitrogen in a Swedish municipality, Västerås. The casestudy has been performed using the ComBoxmodel. The years studiedare 1995 and 1998. The main sectors in society emitting nitrogento water were identified as the agricultural and householdsectors. The dominating sectors emitting nitrogen to air wereidentified as the agricultural, transport and infrastructuresectors. As a basis for discussing data uncertainties qualitatively andquantitatively a literature survey was performed. 50 articles andbooks were identified as in some way or another dealing with datauncertainties in MFA. The literature survey showed that theuncertainties for results from a MFA study might vary between±30 % and a factor 10 depending on what kind of parameter isinvestigated. Only one method was found that dealt with datauncertainties in MFA in a complete way; a model developed byHedbrant and Sörme (HS model). When applying the HS model to the case study of nitrogen flowsin Västerås, it was found that when uncertaintyintervals were calculated the possible conclusions changed. Ofthe two pair of flows compared in relation to priority setting,none of the earlier conclusions remained. Of the three flowsanalysed in relation to following up, only the flow from onepoint source supported the same conclusion when uncertainty wasconsidered. In all, it is concluded that data uncertainties in MFAanalysis are an important aspect and that further research isneeded in order to improve input data quality estimations andframeworks for determining, calculating and presenting data, datauncertainties and results from MFA studies. However, theunderlying reality remains, e.g. that management of materialflows are important for understanding and reducing the negativeenvironmental impact. Thus, MFA is one useful tool in thiswork. <b>Keywords:</b>data uncertainties, sensitivity analysis,Material flow analysis, MFA, method to determine datauncertainties, case study, ComBox model, nitrogenflows. / NR 20140805
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Global stability analysis of complex fluidsLashgari, Iman January 2013 (has links)
The main focus of this work is on the non-Newtonian effects on the inertial instabilities in shear flows. Both inelastic (Carreau) and elastic models (Oldroyd-B and FENE-P) have been employed to examine the main features of the non-Newtonian fluids; shear-thinning, shear-thickening and elasticity. Several classical configurations have been considered; flow past a circular cylinder, in a lid-driven cavity and in a channel. We have used a wide range of tools for linear stability analysis, modal, non-modal, energy and sensitivity analysis, to determine the instability mechanisms of the non-Newtonian flows and compare them with those of the Newtonian flows. Direct numerical simulations have been also used to prove the results obtained by the linear stability analysis. Significant modifications/alterations in the instability of the different flows have been observed under the action of the non-Newtonian effects. In general, shear-thinning/shear-thickening effects destabilize/stabilize the flow around the cylinder and in a lid driven cavity. Viscoelastic effects both stabilize and destabilize the channel flow depending on the ratio between the viscoelastic and flow time scales. The instability mechanism is just slightly modified in the cylinder flow whereas new instability mechanisms arise in the lid-driven cavity flow. We observe that the non-Newtonian effect can alter the inertial flow at both baseflow and perturbation level (e.g. Carreau fluid past a cylinder or in a lid driven cavity) or it may just affect the perturbations (e.g. Oldroyd-B fluid in channel). In all the flow cases studied, the modifications in the instability dynamics are shown to be strongly connected to the contribution of the different terms in the perturbation kinetic energy budget. / <p>QC 20140113</p>
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Caso de negocio para implementar IEC 61850 en una subestación existente del tipo convencional en operaciónBarros Saluz, César Luis, Pacheco Tello, José Edmundo, Paz Egoavil, Miguel Alejandro 27 February 2021 (has links)
El presente trabajo de investigación, presenta una propuesta de Caso de Negocio para el proyecto: Implementar IEC 61850 en una Subestación Existente del Tipo Convencional en Operación, el cual permitirá contar con tecnologías actualizadas para dar mayor eficiencia y rentabilidad al negocio.
En ese sentido para poder determinar la viabilidad de la implementación del proyecto, hemos aplicando las buenas prácticas de la Guía PMBOK®, el cual describe elementos de Dirección de Proyectos para definir el alcance, cronograma y costos (Capex), así como también el desarrollo de un caso de negocio determinando los indicadores financieros para evaluar la viabilidad del Proyecto.
Como resultado de ello, obtenemos TIR: 14.36%, PRI: 6.75 Años, IR: 1.16, ROI: 16.06%, VAN: 153,100.55 USD,
Finalmente, los resultados a los que llegamos nos hacen mostrar que nuestro proyecto es altamente factible de ponerse en marcha, por el impacto en los costos de operación (Opex), operatividad de la subestación, reducción del impacto ambiental, incremento de seguridad, disponibilidad del servicio y flexibilidad. / This research paper presents a Business Case proposal for the implement IEC 61850 project in an already existing thus conventional substation throughout its operation. Therefore this will grant having updated technologies to provide greater efficiency and profitability to the business.
In this scenario, in order to determine the feasibility of the project implementation, the good practices of the PMBOK®️ Guide, were applied, in which it is described the elements of Project Management to define the scope, schedule and costs (Capex), as well as the development of a business case determining the financial indicators to assess the feasibility of the Project. As a result, we obtained IRR: 14.36%, PRI: 6.75 Years, IR: 1.16, ROI: 16.06%, NPV: 153,100.55 USD,
Eventually, the results show that our project is highly achievable to implement, due to the impact on operating costs (Opex), optimization of substation operation, reduction of environmental impact, increased safety, greater service availability and flexibility. / Trabajo de investigación
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Quantifying Uncertainty in the Residence Time of the Drug and Carrier Particles in a Dry Powder InhalerBadhan, Antara, Krushnarao Kotteda, V. M., Afrin, Samia, Kumar, Vinod 01 September 2021 (has links)
Dry powder inhalers (DPI), used as a means for pulmonary drug delivery, typically contain a combination of active pharmaceutical ingredients (API) and significantly larger carrier particles. The microsized drug particles-which have a strong propensity to aggregate and poor aerosolization performance-are mixed with significantly large carrier particles that cannot penetrate the mouth-throat region to deagglomerate and entrain the smaller API particles in the inhaled airflow. Therefore, a DPI's performance depends on the carrier-API combination particles' entrainment and the time and thoroughness of the individual API particles' deagglomeration from the carrier particles. Since DPI particle transport is significantly affected by particle-particle interactions, particle sizes and shapes present significant challenges to computational fluid dynamics (CFD) modelers to model regional lung deposition from a DPI. We employed the Particle-In-Cell method for studying the transport/deposition and the agglomeration and deagglomeration for DPI carrier and API particles in the present work. The proposed development will leverage CFD-PIC and sensitivity analysis capabilities from the Department of Energy laboratories: Multiphase Flow Interface Flow Exchange and Dakota UQ software. A data-driven framework is used to obtain the reliable low order statics of the particle's residence time in the inhaler. The framework is further used to study the effect of drug particle density, carrier particle density and size, fluidizing agent density and velocity, and some numerical parameters on the particles' residence time in the inhaler.
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