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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.
1

An investigation of E-glass structure with different filler material under vibration and bending loading a thesis /

Parra, John R. Kolkailah, Faysal A. January 1900 (has links)
Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on July 17, 2009. Major professor: Dr. Faysal Kolkailah. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree of Master of Science in Aerospace Engineering." "June 2009." Includes bibliographical references (p. 284-287).
2

Hydraulics of plunging drop structures in urban drainage systems

Camino, G. Adriana Unknown Date
No description available.
3

An Investigation of E-glass Structure with Different Filler Material Under Vibration and Bending Loading

Parra, John R 01 June 2009 (has links) (PDF)
Although fiberglass reinforced polyester manholes and wetwalls have been proven by the American Society for Testing Materials (ASTM) and are currently being used in some parts of the world, there still exists a lack of investigation for testing manhole covers made with different inorganic fillers under static and dynamic behavior. The filler would not only improve the mechanical properties of fiber-reinforced polymer matrix composite not otherwise achieved by the resin ingredients alone but also lower the overall manufacturing costs by decreasing the amount of fiber content without adversely affecting the composite’s mechanical properties. The main objective involved the development of fiberglass laminated manhole covers with different inorganic fillers and to study the static and dynamic behavior of the material by performing experimental and numerical analysis. The materials used for the composite laminated test specimens consisted of E-glass woven roving fabric, epoxy, and filler. Two types of inorganic fillers were used for this study, calcium carbonate and high-density adhesive fillers. The static/dynamic test results showed that the laminates made with fiberglass and filler experienced lower performance in tensile strength but higher improvement in flexural strength. The modal analysis results showed that laminates with less filler experienced higher modes within the specified frequency range. This was expected since the material property of filler increased the stiffness and damping behavior in the composite material.
4

Study of manhole degradation of recycled PE rotomolded used in network sewer. / Estudo de degradaÃÃo de poÃos de visita de PE rotomoldado reciclado aplicados em redes coletoras de esgoto

Andre Schramm BrandÃo 24 January 2014 (has links)
Conformity MENDONÃA [10], the investments in sanitation are four times more effective than health. There are currently answering sewage deficit in Brazil, reaching 52.9 percent of the population. The infrastructure of sewage systems of large cities has a huge variety of materials, ranging from concrete to composite materials. Disorders caused by premature failure of materials, applied in sewage systems cause environmental pollution, depreciate image utility/company and even accidents. The manholes represent 15.5 percent of the costs of implementing the sewage systems. This study aims to assess the effects of the degradation of manholes in polyethylene (PE) recycled. The accelerated degradation test simulates the etching with sulfuric acid, present in sewage systems (pH 1.1) of the test specimens for mechanical tensile and impact. The PE was produced by the rotational molding process, from virgin and recycled raw material for comparative purposes. Before the attack the materials were characterized by thermal analysis tests thermogravimetry (TG) and differential scanning colorimetric (DSC), X-ray diffraction, melt index, ash and loads. Data from the thermography images compared with assays term analysis revealed that machining by computer numerical control (CNC) did not change the mechanical properties of specimens for tensile and impact tests . Analyses term perspective and stereopsis revealed flaws in the rotational molding process (bubbles, sink marks and surface irregularity). The crystallinity of recycled PE was greater than virgin PE, this property being obtained by DSC and X-ray. The resistance of the recycled PE fracture was higher, ratified by the crystallinity and moisture present (Technical TG). The melt flow index and mechanical tests revealed that the virgin PE is more ductile than recycled. After the attack the specimens increased their residual mass being 3 times more recycled PE. Destructive of the specimens after chemical attack, trials there were no significant changes in the mechanical properties because of the high standard deviation data, arising from the failure of the material rotational molding process. / Segundo MendonÃa [10], os investimentos realizados em saneamento bÃsico sÃo quatro vezes mais eficazes que na saÃde. Atualmente, hà dÃficit de atendimento de esgotamento sanitÃrio no Brasil, atingindo 52,9% da populaÃÃo. A infraestrutura de redes coletoras de esgoto (RCEs) de grandes cidades possui uma imensa diversidade de materiais, que vÃo desde o concreto atà os materiais compÃsitos. Transtornos causados pela falha prematura dos materiais, aplicados nas redes coletoras de esgoto causam poluiÃÃo ambiental, desgaste da imagem da concessionÃria/empresa e atà acidentes. Os poÃos de visita (PVs) representam 15,5% dos custos para implantaÃÃo de RCEs. Este trabalho tem como objetivo a avaliaÃÃo dos efeitos da degradaÃÃo dos PVs em polietileno (PE) reciclado. O ensaio de degradaÃÃo acelerada simula o ataque quÃmico com Ãcido sulfÃrico, presente nas RCEs (pH de 1,1) dos corpos de prova para ensaios mecÃnicos de traÃÃo e impacto. O PE foi produzido pelo processo de rotomoldagem, de matÃria prima virgem e reciclada, para fins comparativos. Antes do ataque os materiais foram caracterizados por ensaios de anÃlises tÃrmicas de termogravimetria (TG) e colorimetria diferencial de varredura (DSC); difraÃÃo de raios X (DRX); Ãndice de fluidez; teor de cinzas e cargas. Os dados das imagens termogrÃficas comparativamente com os ensaios de termoanÃlises revelaram que a usinagem por meio do controle numÃrico computadorizado (CNC) nÃo alterou as propriedades mecÃnicas dos corpos para os ensaios traÃÃo e impacto. As termoanÃlises e a estereoscopia Ãtica revelaram as falhas do processo de rotomoldagem (bolhas, rechupes e irregularidade na superfÃcie). O grau de cristalinidade do PE reciclado foi maior do que o PE virgem, sendo esta propriedade obtida pelas tÃcnicas de DSC e Raios X. A resistÃncia a fratura do PE reciclado foi superior, ratificada pelo grau de cristalinidade e umidade presente (tÃcnica TG). O Ãndice de fluidez, juntamente com ensaios mecÃnicos, revelou que o PE virgem à mais dÃctil que o reciclado. ApÃs o ataque, os corpos de prova aumentaram sua massa residual, sendo trÃs vezes mais que o PE reciclado. Os ensaios destrutivos dos corpos de prova apÃs o ataque quÃmico, nÃo houve alteraÃÃes significativas das propriedades mecÃnicas, visto o alto desvio padrÃo dos dados, oriundo das falhas do material provenientes do processo de rotomoldagem.
5

Studie obnovy vybrané stokové sítě / The study of rehabilitation of the selected sewer network

Cagášek, Radim January 2017 (has links)
This work deals with the evaluation of the technological state of the sewerage network, as well as the subsequent method of remediation for each failure. The first part contains the accompanying report. This report includes information on the municipality in which the evaluation of the technical condition of the sewerage network took place. Next section includes the actual technical report which has data on the sewage network and its inspection. There are also information about the evaluation of the network‘s technical condition and viable ways of its rehabilitation. At the end of the section there are suggested possible ways of remediation for each of the detected failures. In the next chapter there are calculations for construction technical indicators and the calculation of the capacity of the sewerage network. The last section contains technical data sheet listing the faults of the individual sections and geodetic focus on manholes.
6

Study on Development of Integrated Urban Inundation Model Incorporating Drainage Systems / 下水道システムを考慮した統合都市浸水モデルの開発に関する研究

Lee, Seungsoo 24 September 2013 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第17867号 / 工博第3776号 / 新制||工||1577(附属図書館) / 30687 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 中川 一, 教授 戸田 圭一, 准教授 川池 健司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
7

Signal characteristics of acoustic emissions from the axial strain in polyethylene manhole / CaracterizaÃÃo do sinal de emissÃo acÃstica proveniente da deformaÃÃo axial em poÃo de visita de polietileno

Marcos Daniel Gouveia Filho 02 February 2015 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / The use of new materials in the sanitation industry aims to improve water treatment conditions and optimize the performance of the structures of sewage systems. Studies show that investments in sanitation are four times more effective than health. Manhole (PV) is an integral structure of the collection networks of major importance sewage because it is the sewage flow of the meeting from various facilities that are guided and follow for further processing. Non-destructive tests are widely used in modern industry worldwide to evaluate the quality and detection of changes in structure, small surface flaws, presence of cracks and other physical disruptions, being capable of detecting flaws in structures prematurely allowing constant monitoring and real time frame. The technique of acoustic emission (AE) is effective both during subsequent tests the implementation of the structure, guaranteeing their structural integrity, and in the real-time monitoring of the frame subject to the usual charging service, while performing its function without need of interrupting. To properly investigate the structure is necessary to know how the defects are and their respective acoustic activity. In this study, the acoustic emission signals generated in polyethylene manholes by variable axial deformation during loading are characterized both in time domain and in the frequency domain creating the signature of the defect. / A utilizaÃÃo de novos materiais na indÃstria do saneamento, visa melhorar as condiÃÃes do tratamento de Ãgua e otimizar o desempenho das estruturas de redes coletoras de esgoto. Estudos comprovam que os investimentos realizados em saneamento bÃsico sÃo quatro vezes mais efetivos que na saÃde. PoÃo de visita (PV) à uma estrutura integrante das redes coletoras de esgotos de grande importÃncia, pois nele ocorre o encontro do fluxo de esgotos provenientes de diversas instalaÃÃes que sÃo orientados e seguem para o posterior tratamento. Os ensaios nÃo destrutivos sÃo largamente utilizados na indÃstria moderna em todo o mundo para avaliaÃÃo da qualidade e detecÃÃo de variaÃÃes na estrutura, pequenas falhas superficiais, presenÃa de trincas e outras interrupÃÃes fÃsicas, sendo capaz de detectar prematuramente falhas em estruturas permitindo a monitoraÃÃo constante da estrutura e em tempo real. A tÃcnica de emissÃo acÃstica (EA) à eficaz tanto na fase de testes subsequentes à implementaÃÃo da estrutura, garantindo sua integridade estrutural, quanto no monitoramento em tempo real d a estrutura sujeita a carregamento usual de serviÃo, enquanto desempenha sua funÃÃo, sem necessidade de interrupÃÃo. Para investigar corretamente a estrutura à necessÃrio conhecer como os defeitos se manifestam e sua respectiva atividade acÃstica. Neste trabalho, os sinais de emissÃo acÃstica gerados em poÃos de visita de polietileno por deformaÃÃo axial durante carregamento variÃvel sÃo caracterizados tanto no domÃnio do tempo quanto no domÃnio da frequÃncia criando a assinatura do defeito.
8

Odkanalizování odpadních vod z průmyslového areálu ve městě Hulín / Drainage of waste water from the industrial area in Hulin city

Dohnal, Radek January 2015 (has links)
The subject of this thesis is to implement the passport of sewer system installation, technical assessment and evaluation of the technical condition of the entire sewer network in the industrial area, along with focus and plotting the current leadership of the sewerage system. It was also developed a hydraulic model of the entire solution sewer system. In the second part of the study is a proposal for an appropriate treatment system of wastewater. It was also developed a hydraulic model of the entire solution sewer system. In the second part of the study is a proposal for an appropriate treatment system of wastewater. In conclusion there is a financial assessment and comparison of different variants cleaning system in terms of investment and operating costs.
9

The analysis and application of artificial neural networks for early warning systems in hydrology and the environment

Duncan, Andrew Paul January 2014 (has links)
Artificial Neural Networks (ANNs) have been comprehensively researched, both from a computer scientific perspective and with regard to their use for predictive modelling in a wide variety of applications including hydrology and the environment. Yet their adoption for live, real-time systems remains on the whole sporadic and experimental. A plausible hypothesis is that this may be at least in part due to their treatment heretofore as “black boxes” that implicitly contain something that is unknown, or even unknowable. It is understandable that many of those responsible for delivering Early Warning Systems (EWS) might not wish to take the risk of implementing solutions perceived as containing unknown elements, despite the computational advantages that ANNs offer. This thesis therefore builds on existing efforts to open the box and develop tools and techniques that visualise, analyse and use ANN weights and biases especially from the viewpoint of neural pathways from inputs to outputs of feedforward networks. In so doing, it aims to demonstrate novel approaches to self-improving predictive model construction for both regression and classification problems. This includes Neural Pathway Strength Feature Selection (NPSFS), which uses ensembles of ANNs trained on differing subsets of data and analysis of the learnt weights to infer degrees of relevance of the input features and so build simplified models with reduced input feature sets. Case studies are carried out for prediction of flooding at multiple nodes in urban drainage networks located in three urban catchments in the UK, which demonstrate rapid, accurate prediction of flooding both for regression and classification. Predictive skill is shown to reduce beyond the time of concentration of each sewer node, when actual rainfall is used as input to the models. Further case studies model and predict statutory bacteria count exceedances for bathing water quality compliance at 5 beaches in Southwest England. An illustrative case study using a forest fires dataset from the UCI machine learning repository is also included. Results from these model ensembles generally exhibit improved performance, when compared with single ANN models. Also ensembles with reduced input feature sets, using NPSFS, demonstrate as good or improved performance when compared with the full feature set models. Conclusions are drawn about a new set of tools and techniques, including NPSFS and visualisation techniques for inspection of ANN weights, the adoption of which it is hoped may lead to improved confidence in the use of ANN for live real-time EWS applications.
10

Brunnars påverkan på cyklisters körbeteende : En kvantitativ undersökning kring cyklisters körbeteende vid passage av brunnslock på dubbelriktade cykelbanor / Manholes impact on cyclists’ behaviour : A quantitative survey about cyclists’ behaviour when passing by manhole covers on bi-directional cycle paths

Jändel, Simon, Kvarnefalk, Albin January 2021 (has links)
För att uppnå ett hållbart samhälle krävs en omställning av transportsystemet. Region Stockholmsmålsättning är att andelen cykelresor ska mer än dubbleras till år 2030 och stå för 20% av alla resor ilänet. Bristande underhåll och dålig utformning på cykelbanor står för ca 60% av allvarligasingelolyckor på cykel. Denna ökning av cykelresor ställer därmed höga krav på utformning ochunderhåll av cykelinfrastrukturen. För att cykelbanans komfort ska vara god, krävs det attcykelbanan är jämn, vilket kan komma i konflikt med brunnslock, då det ofta uppstår sättningar ibeläggningen omkring brunnarna. Brunnslocken kan upplevas som obehagliga att cykla över och haräven lägre friktion än omkringliggande yta. Detta kan resultera i halka vilket särskilt är påtagligt närvägbanan är fuktig. Brunnslock är vanligt förekommande på cykelbanor, i denna studie inventeradesde centrala delarna av elva regionala cykelstråk och där förekom ca 1200 brunnslock. Dessa var avvarierande storlek, position i cykelbanan och höjdläge jämfört med den omkringliggandebeläggningen. Brunnslock kan vara ett potentiellt hinder på cykelbanor, vilket minskar cykelbananstillgängliga bredd. Cykelbanans tillgängliga bredd är den yta som är funktionellt möjlig att cykla på.Konstruerad bredd är däremot den bredd cykelbanan byggdes med utan hänsyn till eventuellahinder.Syftet med studien är att undersöka ifall brunnslock, specifikt manhålsbrunnar och kabelbrunnar,anses vara ett hinder för cyklister på cykelbanor och hur brunnslocken påverkar den tillgängligabredden på de fyra studieplatserna. Den tillgängliga bredden på studieplatserna jämförs medrekommenderade cykelbanebredder i handböcker. Studien avgränsades för att eftersträvastudieplatsernas likvärdighet och att enbart brunnslockens egenskaper skilde studieplatserna åt. Destuderade brunnslocken var: manhålsbrunn med och utan kant samt kabelbrunn med och utan kant.Studiens resultat visar det finns en skillnad mellan situationer med och utan mötande cyklist.Majoriteten av cyklisterna håller sig till höger om brunnslocken oberoende av möte eller ej möte,vilket kan bero på deras naturliga sidledsposition. När det inte är möte väljer många att cykla tillvänster om brunnslocken. Däremot, i situationer med möte väljer nästan ingen att cykla till vänsterom brunnslocken. Minskningen i antal som cyklar vänster om brunnslocken vid möte motsvararungefär ökningen i antal som cyklar höger om brunnslocken i samma situation. Antalet som cyklaröver brunnslock skiljer sig marginellt mellan situationer med och utan möte. Detta kan tolkas somatt cyklister byter sida om brunnslocken och undviker att cykla över dem. Vid de fyra studieplatsernaär det få som cyklar över brunnslocken vilket gör att dessa brunnslock troligen bör ses som etthinder som minskar den tillgängliga bredden.Det kan konstateras att de undersökta kabelbrunnarna är ett större hinder för cyklister änmanhålsbrunnarna. Brunnslock med kant är ett större hinder än brunnslock utan kant. Fler brunnarbehöver studeras innan det går att dra mer generella slutsatser om brunnslock på cykelbanor. Dettagäller både de undersökta brunnarna och andra sorters brunnar.Den tillgängliga bredden på studieplatserna jämfördes med rekommenderade cykelbanebredder idessa handböcker: VGU, GCM-handboken, Stockholms läns regionala cykelplan, Stockholmscykelplan, Cykeln i staden och Solnas cykelplan. Bredderna som rekommenderas i handböckernauppfylls inte sett till den tillgängliga bredden på studieplatserna. / The transport system must transform to achieve a sustainable society. Region Stockholm's goal is forthe proportion of bicycle trips to more than double by 2030 and account for 20% of all trips in thecounty. Lack of maintenance and poor cycle paths account for about 60% of serious single accidentson bicycles. This increase consequently places high demands on the design and maintenance of thebicycle infrastructure. For the cycle path's comfort to be good, it is required that the cycle pathremains even, which can come into conflict with manhole covers, as subsidence often occur at andaround the manholes. The manhole covers can be experienced as unpleasant to cycle over and havelower friction than the surrounding surface. This can cause skidding, especially if the road surface iswet. Manhole covers are common on cycle paths, in this study 1 200 manhole covers were found onthe central parts of eleven regional cycle paths. These were of varying size, position in the cycle pathand height compared to the surrounding pavement. Manhole covers can be a potential obstacle oncycle paths, which reduces the available width of the cycle path. The available width of the cyclepath is the surface that is functionally possible to cycle on. Constructed width, on the other hand, isthe width the cycle path was built with without regard to any obstacles.The purpose of the study is to investigate whether manhole covers are considered an obstacle forcyclists on cycle paths and how the manhole covers affect the available width of the four study sites.The available width of the study sites is compared with recommended cycle path widths inguidelines. The study was delimited to strive for the equivalence of the study sites and that only theproperties of the manhole covers separated the study sites. Two types of manhole covers werestudied and these two types were also studied with and without edges.The results of the study show that there is a difference between situations with and without anoncoming cyclist. A majority of cyclists stay to the right of the manhole covers regardless ofoncoming cyclist or not, which may be due to their natural lateral position. When there is nooncoming cyclist, many choose to cycle to the left of the manhole covers. However, in situations ofencounter, almost no one chooses to cycle to the left of the manhole covers. The decrease in thenumber of cyclists to the left of the manhole covers at an encounter roughly corresponds to theincrease in the number of cyclists to the right of the manhole covers in the same situation. Thenumber who cycle over manhole covers differs marginally between situations with and withoutoncoming cyclists. This can be interpreted as cyclists changing sides of the manhole covers andavoiding cycling over them. At the four study sites, few people cycle over the manhole covers, whichmeans that these manhole covers should probably be seen as an obstacle that reduces the availablewidth.It can be stated that the manhole covers with edges are a greater obstacle than manhole coverswithout edges. More manholes need to be studied before it is possible to draw more generalconclusions about manhole covers on cycle paths. This applies to both the investigated manholesand other types of manholes.The available width of the study places was compared with the recommended cycle path widths inthese guidelines: “VGU”, “GCM-handboken”, “Stockholm County's regional cycle plan”, “Stockholm'scycle plan”, “Cykeln i staden” and “Solna's cycle plan”. The widths recommended in the guidelinesare not met in terms of the available width of the study places.

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