Dissertationen: „Pipeta“

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Diehl, Gustavo Nogueira. „Nova pipeta para inseminação intra-uterina em suínos“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2005. http://hdl.handle.net/10183/4814.

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A inseminação intra-uterina (IAU) permite reduzir o número de espermatozóides e o volume de diluente em comparação à inseminação tradicional. No entanto, a técnica ainda apresenta algumas limitações a serem superadas para que seja uma alternativa de diminuição dos custos de cobertura. O objetivo deste trabalho foi avaliar o desempenho reprodutivo de 423 fêmeas suínas de ordem de parto 1 a 9 submetidas à inseminação intra-uterina (IAU), com um novo modelo de pipeta (T1) cuja extremidade não é fixada na cérvix ou uma pipeta de IAU modelo Verona® e que permite a fixação da sua extremidade em espiral na cérvix (T2). Para comparar as duas pipetas foi considerado o grau de dificuldade para realização das inseminações, o tempo necessário para realizálas, presença de sangramento após a inseminação, a presença de refluxo no momento da inseminação, as taxas de retorno ao estro (TR), de prenhez (TPR) e de parto ajustada (TPA), além do número de leitões nascidos (NT). As fêmeas de ambos os grupos foram inseminadas com doses de 1 bilhão de espermatozóides, em intervalos de 24 horas. A passagem do cateter de IAU através da cérvix foi possível em 95,9% das fêmeas, sem diferença entre os tratamentos (P>0,05). Em pelo menos uma das inseminações, foi observado sangue no cateter, após a realização da IAU, em 20,6% das fêmeas do T1 e 15,2% das fêmeas do T2 (P=0,14). O tempo médio necessário para realizar a inseminação foi de 2,1 minutos para o T1 e 2,3 minutos para o T2 (P=0,26). O percentual de fêmeas com refluxo de sêmen no momento da inseminação foi maior (P=0,01) no T1 (8,4%) em comparação ao T2 (2,9%). Não houve diferença (P>0,05) nas variáveis TR (8,0 e 4,8%), TPR (93,4 e 96,2%) e NT (12,4 e 12,7 leitões) entre T1 e T2, respectivamente. A TPA do T1 (90,6%) apresentou tendência (P=0,07) de ser inferior à do T2 (95,1%). No T1, as fêmeas primíparas apresentaram maior TR e menor TPA em comparação às pluríparas (P<0,05). Os resultados mostram que a nova pipeta pode ser utilizada sem prejuízos ao desempenho reprodutivo, em fêmeas pluríparas, mas sugerem cautela para sua utilização em fêmeas primíparas.

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Čížek, Petr. „NÁVRH AUTOMATICKÉ PIPETOVACÍ HLAVY NA PRINCIPU PERISTALTICKÉHO ČERPADLA“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-442866.

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The aim of this diploma thesis is to design and create a prototype of automatic pipetting head that will be useful for pipetting in laboratories after attaching it to a robotic manipulator. In the beginning, a research about various types of automatic pipetting heads was made followed by a device design and component analysis. The prototype was made using 3D printing method and it utilises a peristaltic pump, Arduino microcontroller and Bluetooth interface. A measurement of repeatability and dispensing accuracy was made on the finished device. The results are evaluated in the conclusion.

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Nilsson, Simon, und Johan Widmark. „PIPER : Robot for vertical in-pipe climbing“. Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264440.

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In old houses, the pipes can often be in poor conditions and require cleaning to improve air quality. There are robotic solutions to this problem but often only for large industrial pipes and not for regular pipes that you would find in your home. Pipes can often be hard to access and even harder to determine the pipe’s condition. This thesis aims to research and build a small robot that can travel through pipes, gather footage and attempt to clean them. The goal is to create a robot that can climb vertically in pipes, record video inside of the pipes and detect obstacles. After research was done a prototype was built. The prototype uses spring loaded pistons that pushes wheels against the walls of the pipes to provide friction for vertical travel. To be able to perform all these tasks, the robot uses tools that can be exchanged depending on what needs to done. The ability to turn in pipes has been ignored in this thesis due to time restrictions but could be done as future work. The resulting prototype is a robot that can steadily travel vertically through pipes, carry its own weight of 750 grams and an additional load of up to 500 grams. The robot is able to stop at pre-determined locations by measuring the distance it has travelled by using a hall-effect sensor.
I gamla hus kan ventilationsrör ofta vara i dåligt skick och vara i behov av städning eller reparation för att öka luftkvalitén. Det finns robotar som loser detta problem men de är ofta skapade för stora industriella rör och inte för rör som man hittar hemma. Rör kan ofta vara svåra att komma åt och det kan vara ännu svårare att veta vilket skick rören är i. Det här projektet ska ta fram en liten robot som kan färdas genom rör och spela in video. Om tid finns, ska den också städa upp i rören. Målet med projektet är att skapa en robot som kan klättra vertikalt i rör, spela in video inuti rören och upptäcka hinder. Efter forskning så byggdes en prototyp. Prototypen använder fjädrade kolvar som trycker hjulen mot väggarna i röret och utvecklar därmed friktion för att kunna färdas vertikalt. För att kunna utföra uppgifterna så kommer roboten att kunna använda olika verktyg som byts ut beroende på vad som behöver utföras. Möjligheten att kunna svänga i rören har ignorerats i det här projektet på grund av tidsbegränsning men bör ses över vid framtida utveckling. Den slutgiltiga prototypen är en robot som kan färdas stabilit vertikalt genom rör, lyfta sin egna vikt på 750 gram och en extra vikt på upp till 500 gram. Roboten kan också stanna vid förbestämda platser då den kan mäta hur långt den färdats genom att använda en hall effekt sensor.

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Weerasekara, Lalinda. „Pipe-soil interaction aspects in buried extensible pipes“. Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/38050.

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The performance of buried pipelines in areas subjected to permanent ground displacements is an important engineering consideration in the gas distribution industry, since the failure of such systems poses a risk to public and property safety. Although, the ground movements and its variations over time can be detected and mapped with reasonable confidence, these data are of little use due to a lack of reliable models to correlate such displacements to the condition of the buried pipe. The objective of this thesis is to develop methods to estimate the pipe performance based on the measured ground displacement. An analytical method was developed to estimate the pipe performance when the pipe is subjected to tensile loading caused by the relative ground movements occurring along the pipe axis. As a part of the derivation, a modified interface friction model was developed considering the increase in friction due to constrained dilation of the soil, and the impact of mean effective stress on soil dilation. This interface friction model was combined with a nonlinear pipe stress–strain model to derive an analytical solution to represent the performance of the pipe. Using the proposed model, axial force, strain, and mobilized frictional length along the pipe can be obtained for a measured ground displacement can be obtained. Large-scale field pipe pullout tests were performed to verify the results of the proposed analytical model, in which good agreements were observed for tests conducted at different soil/burial conditions, displacement rates and pipe properties. Considering the similarities in the axial pullout mechanism, the analytical model was extended to explain the pullout response of geotextiles buried in reinforced soil structures. In this derivation, a new interface friction model was developed for planar members by considering the changes in normal stress due to constrained soil dilation. Another analytical model was derived for the case of a pipe that is subjected to combined loading from axial tension and bending when the initial soil loading is acting perpendicular to the pipe axis. With the direct account of the axial tensile force development, more realistic pipe performance behaviors were obtained as compared to the results obtained from traditional numerical formulations.

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Krantz, Richard. „PIPETT 1“. Thesis, Konstfack, Institutionen för Konst (K), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-5784.

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PIPPET 1 tar avstamp i 10 olika spår eller riktningar som är tongivande för mitt konstnärsskap. Av 10 spår valdes 3 slumpmässigt ut; Öknen, Humorn och Språket. De övriga finns nämnda i uppsatsens appendix. Då min konstnärliga praktik är projektbaserad och diskparat både i estetik och koncept, syftar detta till att bena ut min egen praktik för att komma närmare pudelns kärna. De olika spåren tar upp både populärkulturella och konstnärliga referenser, samt några få personliga anekdoter som har bäring för dem. Även tankar och kritiska reflektioner om egna konstverk tas upp.I "Öknen" disskuteras det sökande och det mytiska. "Humorn" kretsar kring den relativt nya teoribildningen Concrete Comedy, som utformats av konstnären och skribenten David Robbins. I "Språket" disskuteras användandet av ord och text som bilder, men bortom det typografiska och litterära.

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AL, Tarawneh Bashar K. „Comparison between field and analytical results on the structural performance of deeply buried 42&60-inch diameter high density polyethylene pipes“. Ohio University / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1174411226.

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7

Reginold, Jesuthasan Terence. „Rocker pipe solution to alleviate settlement induced distress in flexible pipes“. Thesis, University of East London, 2006. http://roar.uel.ac.uk/1257/.

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A number of earlier researchers investigated the soil structure interaction parameters which affect the structural behaviour of buried flexible pipes. However, it was not until the mid-1990s that the importance of rocker pipe design to accommodate differential settlement raised awareness of the consequent absence in current design procedure [BS EN 1295-3; 1998]. This study widens the understanding of the effect of differential ground movements on the behaviour of flexible pipes to address concerns raised to the Committee European de Normalisation. Many pipeline failures result from the excessive strains developed in the vicinity of the junction between a pipe and a settling structure. Case studies of such failures are presented in this thesis, which demonstrates that it can occur not only in large diameter pipeline but also in small diameter domestic pipeline systems. A method of analysis and the use of developed appropriate rocker pipe length is an industrially useful outcome of this research. Analytical solutions for flexible pipes have been developed based on the concept of beams on elastic foundation approach. Non-dimensional relationships have been developed and are presented in the form of charts. These charts permit hand calculations and rapid verification of structural design of the pipeline and, thus, assess the integrity of the existing pipelines located in areas with ground instability. Knowledge of the soil strength and sub-grade modulus is required, along with pipeline geometry and pipe stiffness, to apply the non-dimensional relationships. The soil parameters can be measured in situ or estimated using empirical correlations. The cause for failure has been investigated with the proposed analytical soil structure interaction approach which identifies the zone of distress in the pipeline. The analysis has been extended to demonstrate how a rocker pipe system can be incorporated to alleviate such distress. The concept of rocker pipes has also been investigated in the study through laboratory scale testing. Soil box tests, with ground conditions defined through plate/pipe load testing, have been developed. Full-scale testing on flexible pipes instrumented with FlexiForce pressure sensors at the pipe invert, strain gauges measuring strain due to induced differential settlement on the pipe crown and deflection transducers measuring deflection profiles along the pipe length due to differential settlement of the end structure, have been used to validate the mathematical modelling. Ile combination of rocker pipes with flexible joints and elastic effects removes the distress imposed by the differential settlement, and provides the possibility for a better comparison with the data obtained from both theoretical analysis and experimental tests. Results from each of these approaches are compared with those from experiments. It is concluded that there is need for a rational design procedure analysis for rocker pipes to be incorporated into codes of practice, such as EN 1295.

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Perotti, Tania. „Nanetto Pipetta : modos de representação“. reponame:Repositório Institucional da UCS, 2007. https://repositorio.ucs.br/handle/11338/242.

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Este estudo busca analisar determinados elementos de representação, presentes no Nanetto Pipetta de Aquiles Bernardi (1937). Entre eles, os aspectos culturais foram analisados de maneira mais detida, ao lado de questões sociais e políticas. A partir da análise e da interpretação, buscou-se compreender como aconteceu o trânsito da cultura da imigração italiana do Rio Grande do Sul de seu contexto real para os limites comportados pelo âmbito da ficção apresentados na obra. Nesse processo de transfiguração, buscou-se compreender de que maneira a cultura da imigração italiana e a cultura clerical colaboraram para que o texto literário analisado assumisse os contornos que o constituem, bem como qual o resultado dessa conjugação.
Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-05-15T17:43:38Z No. of bitstreams: 1 Dissertacao Tania Perotti.pdf: 661348 bytes, checksum: 565b097bf4f823776f7a601377c84d49 (MD5)
Made available in DSpace on 2014-05-15T17:43:38Z (GMT). No. of bitstreams: 1 Dissertacao Tania Perotti.pdf: 661348 bytes, checksum: 565b097bf4f823776f7a601377c84d49 (MD5)
This study has searched the comprehension about certain representation structures found in Aquiles Bernardi s (1937) work. Among the aspects which build up this representation, the cultural aspects had been analysed in order to be more specific, which doesn t exclude social and politic questions when necessary. It s about a route where, from the analyses and interpretation, i tried to understand how the Italian Immigration culture from Rio Grande do Sul changes happened from its real context to the limits concerning the fiction aspect present in the book which is this work s corpus. In this process i intended to comprehend in what way the Italian Immigration and the clergy culture were helpful to the analysed work, as well as the result of this conjugation.

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9

Mao, Feng. „Permeation of hydrocarbons through polyvinyl chloride (PVC) and polyethylene (PE) pipes and pipe gaskets“. [Ames, Iowa : Iowa State University], 2008.

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10

Shimoga, Ramesh. „Structural behavior of jointed leachate collection pipes“. Ohio : Ohio University, 1999. http://www.ohiolink.edu/etd/view.cgi?ohiou1175621396.

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11

Moran, Alan P. „Comparison between field and analytical results on the structural performance of deeply buried 30-inch diameter thermoplastic pipes“. Ohio : Ohio University, 2001. http://www.ohiolink.edu/etd/view.cgi?ohiou1174052234.

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12

Burton, M. J. „An experimental and numerical study of plug formation in vertical pipes during cryogenic pipe freezing“. Thesis, University of Southampton, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373569.

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13

Kastner, Robert Eugene Lee. „Structural performance of plastic pipe used for landfill leachate collection“. Ohio : Ohio University, 1992. http://www.ohiolink.edu/etd/view.cgi?ohiou1172687975.

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14

Bircan, Mehmet. „A Study On The Effect Of Pipe - Soil Relative Stiffness On The Behaviour Of Buried Flexible Pipes“. Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/2/12611562/index.pdf.

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In this study, the effect of pipe-soil relative stiffness on the behaviour of buried flexible pipes was investigated considering the pipe size, material type, stiffness, pipe-soil and natural soil-backfill interfaces and geometry of the trench using the finite element method. For this purpose, a parametric study was conducted to examine the effect of different variables on the resulting earth loads and deformations imposed on the buried pipes. Various types of trench pipe-soil cases were analysed for a certain natural ground and backfill material by the PLAXIS finite element code which allows simulating non-linear soil behaviour, the stages of construction as well as the pipe-soil interaction aspects of the problem. Loads and deformations obtained by the finite element method were compared with those calculated by the conventional approaches for different pipe-soil stiffness ratios. The finite element results obtained for the deformation of typically flexible Polyethylene pipes were then used to back-calculate the range of modulus of soil reaction, E'
, values for various pipe-soil relative stiffness and they were compared with the suggested value proposed by Howard (1977).

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Choollun, Virendra Kumar. „Residual stresses in high density polyethylene pipes with particular reference to its effects on soil-pipe interaction“. Thesis, University of East London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.532873.

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Previous studies of high-density polyethylene pipes have been based on the premise that residual stresses have no effects and have almost no role to play in the failure and performance of theses pipes. It is thought that previous studies have underestimated the effects of the residual stresses in pipes at the design stage particularly when assessing pipe-soil interaction and ground loading effects. This project tried to assess the effect of residual stresses in soil-pipe interaction of HDPE (PEIOO) pipes, and opened two main areas of research: (a) to investigate the actual residual stress profile in the pipes as a result of the manufacturing process; and, (b) to take these residual stress profiles, which have been previously ignored, in consideration to assess the performance of the pipe and the surrounding soil. A review of the existing techniques available for the determination of residual stresses was carried out and a literature review was done on how these techniques were used by various authors. On the whole, most of these techniques involved destructive tests that are believed, here, to alter the residual stress profile and magnitude in the pipe wall. The current study has tried to develop an innovative stress-optical technique for the determination of residual stresses with minimal alteration to the residual stress profile and its magnitude. After determining the residual stress profile and magnitudes by the new method, the interaction of the residual stress with internal pressure effects and ground loading effects on pipes is studied. The studies included the numerical modelling of the pipe when the residual stress in the pipe wall incorporated and the pipe subjected to internal pressure loading as well as external loadings from the weight of the surrounding soil. A number of earlier researchers have investigated the soil structure interaction parameters which affect the structural behaviour of buried flexible pipes. However, to date none of the studies have incorporated residual stresses in pipe-soil interaction modelling and the current study has raised awareness of the consequent absence in current design procedure [BS EN 1295-3; 1998].

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Tanyanyiwa, Craig Tinashe. „Towards practical pressure-based leakage characterisation of water distribution pipes with a novel pipe condition assessment device“. Master's thesis, Faculty of Engineering and the Built Environment, 2019. https://hdl.handle.net/11427/31785.

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Leakage detection and management have been proposed as effective ways of mitigating and managing water losses in an age where water scarcity has become prevalent. To this end, several methods have been developed and suggested with different benefits and drawbacks The presently available leakage detection methods, however, fail to identify and characterise the leakage while simultaneously assessing the condition of the water distribution network (WDN). This function is imperative for understanding and addressing leakage. WDN assessments are also important as knowledge of the network parameters helps in reducing water losses through planned infrastructure maintenance programmes. A pipe condition assessment device (PCAD) was thus developed which can detect, characterise leakage and assess the condition of the WDN. However, the efficacy and reliability of this device had not yet been established. In this study, the device was used to characterise leakage and assess system conditions in water networks. Initially, laboratory tests on six known leak types were conducted on a standardised laboratory setup. The leakage characteristics of these pipes were found through regression analysis. The results from the tests established that to 95% level of confidence; the standardised setup can produce repeatable and comparable results to previous studies. The accuracy of the PCAD instrumentation was verified and the device calibrated, the same pipes were then tested on the standardised setup using the PCAD. An overlap of the results from the laboratory experiments and the PCAD revealed that to 95% level of confidence, the device could adequately characterise leakage in pipes. A low variance of less than 4% of the mean parameter, across all tests conducted using the PCAD, informed that the results obtained through using the PCAD are repeatable and reliable. Field tests in the Kensington DMA were done and revealed the limitations of the device, such as its inability to characterise leakage in pipe sections that cannot be successfully isolated. However, in pipelines that were successfully isolated, the PCAD was able to detect and identify leakage characteristics in water networks and aid in conducting maintenance runs. Consequently, this study contributed to the body of knowledge by statistically establishing that the PCAD could adequately, and reliability characterise leakage in real water distribution networks.

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Dumalisile, Sinovuyo. „A study in consumers willingness to purchase water efficient fittings“. Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97320.

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Thesis (MBA)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: The continuous growth in the world’s population together with the increasing scarcity of water resources, especially drinkable water, has cultivated an environmentally-conscious society. As consumers are looking for eco-friendly alternatives or methods, manufacturers are including environmentally-friendly (EF) products in their product mix to address this topic. However, there seems to be a disconnect between manufacturers of EF product solutions and consumers. Consumers are either not aware of EF products or they are still hesitant in adopting environmentally-friendly products as the perception is that they are either too expensive or there is something amiss with the product’s functionality. It is up to suppliers and marketers of EF goods to do a better job of educating consumers about their products. This research study was conducted to understand the domestic consumer’s ecological behaviour and key influencing factors when purchasing water-efficient fittings. The literature review in this study gives us background on the status quo in terms of climate change, the green consumer, and water supply issues. A survey was conducted amongst domestic consumers in the plumbing retail environment to test their willingness to purchase water-efficient fittings based on their profile, habits and key influencing factors. The profile of the respondent showed a consumer who is more affluent. The water-efficient consumer’s primary concern is to save costs by reducing their water bill. Cost saving is the key influencing driver in terms of consumer’s willingness to purchase water-efficient fittings.

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Bratlie, Andreas, und Christian Bergstrøm Hillestad. „Impact on Duplex Steel Pipes with Precipitated Sigma-phase : Modeling a Full-scale Impact Test on Pipe Fittings“. Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for konstruksjonsteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18722.

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Duplex stainless steel (DSS) is a common material in offshore pipe fittings. A manufacturing defect has altered the behavior of the components through an erroneous heat treatment, which has led to precipitation of 𝜎-phase. A report showing a strong correlation between precipitated 𝜎-phase and the reduction in impact toughness, initiated a great interest in the offshore industry for further studies of the effect of precipitated 𝜎-phase in DSS pipe fittings. In this thesis a numerical approach to simulate the behavior of duplex stainless steel with precipitated 𝜎-phase has been performed. The simulations have been done using the Gurson material model, which is implemented in the user defined material model in the SIMLab Metal Model. In addition the material model has been combined with a brittle fracture criterion. The results deviate from the observations done in the laboratory. The reasons for the deviations were found to be quite complex, but effects from mesh sensitivity and incorrect material optimization was found. The influence of the Gurson model is limited for the specimens acting in a brittle manner. It is therefore considered unnecessary to apply this material model for these problems.

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Iwanaga, Mauricio Kiotsune. „Development of a virtual pipe test rig for testing acoustic correlators for leak detection in buried water pipes /“. Ilha Solteira, 2019. http://hdl.handle.net/11449/183466.

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Orientador: Michael John Brennan
Resumo: Vazamentos em tubulações de água enterradas são considerados um importante problema já que uma grande quantidade de água é desperdiçada entre a planta de tratamento e os consumidores. Para lidar com tal problema, companhias de saneamento utilizam dispostivos para localizar vazamentos nas tubulações. Dispositivos de escuta e correlacionadores de ruídos são os equipamentos mais utilizados em campo pelas companhias de sanemaneto ao redor do mundo. Correlacionadores de ruídos são dispositivos usados na localização de vazamentos em tubulações enterradas através da estimativa do tempo de atraso entre os sinais medidos pelos sensores posicionados em ambos os lados de um suposto vazamento. Uma vez que as companhias de saneamento devem decidir qual tipo de correlacionador é o mais compatível com a sua rede de tubulações, elas devem realizar alguns testes para ajudar em tal decisão e para treinar os funcionários que operam estes dispositivos, os quais devem ser expostos a diferentes condições, tais como tubos de diferentes materiais e geometrias, diferentes tipos de solo, vazamentos com diferentes intensidades, etc. Neste contexto, o principal objetivo desta pesquisa é contribuir com esta necessidade através da elaboração de um dispositivo de bancada capaz de reproduzir as vibrações de um tubo causadas por um vazamento. O dispositivo, chamado de simulador virtual de vazamentos, é composto por um computador, um amplificador de potência com dois canais e dois shakers. Ruídos de vazamento... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Leakage in buried water pipes is an important problem since a large amount of water is wasted between the treatment plant and the consumers. To deal with such a problem, water companies have used some devices to localize leaks in the pipe network. Listening devices and leak noise correlators are the most popular equipment used in the field by the water companies around the world. Leak noise correlators are important devices used to localize leaks in buried pipes by calculating the time delay between the signals measured by the sensors positioned either side of a suspected leak. Since water companies have to decide which leak noise correlator is more suitable for each pipe network, they have to carry out some field tests to assist in this decision and to train the personnel that handles such a device, which ideally must be exposed to different conditions, such as pipes with different materials and geometries, different types of soil, different leak strengths, etc. The main objective of this research project is to contribute with the necessity of the water companies by designing an indoor bench-top device capable to reproduce the pipe vibrations generated by a leak in the field. The device, called virtual pipe test rig, comprises a computer and a dual-channel power amplifier supplying two shakers. In the computer, leak noise is synthesized by using a model of a buried leaking pipe implemented using the software Matlab®. Since the systems, composed by the power amplifiers and th... (Complete abstract click electronic access below)
Mestre

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Fernando, Mihindukulasooriya E. R. „Field performance of corrugated plastic pipes under simulated high soil cover“. Ohio : Ohio University, 1992. http://www.ohiolink.edu/etd/view.cgi?ohiou1172266770.

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21

Andersson, Christian. „Rigid Pipelay Curve Stability“. Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25882.

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Pipeline installation would generally involve curved sections in the horizontal plane, due to existing subsea infrastructure or natural seabed characteristics. At a small curve radius, the lateral seabed friction could be insufficient providing on-bottom stability of the pipeline. Hence, additional measures like lateral supports, so called turnpoints, may be required. The effect of installing such turnpoints have been studied in this thesis, using a computer software called SIMLA. Both static and dynamic analyses have been performed in order to preserve the curve stability and control the load effect on the pipeline and the turnpoints. In the static analyses, the pipe is being fed out from the Seven Navica lay vessel. In this way, history effects get introduced as the pipe elements experience the operation from being fed out until it rests on the seabed. The dynamic analyses is carried out at the stage in the laying process that results in the highest dynamic response.The pipeline investigated is a 10" ID production pipeline laid between two templates. The route is assumed to have a constant water depth, and consists of two straight distances having a curved section with a curve radius of 400 [m] in between. In the route, originally 10 turnpoints have been installed. In order to investigate whether this is a over-conservative number, the analyses performed in this thesis have been conducted for 3-10 turnpoints along the route.In the static feeding analysis, the axial friction is turned off during laying. This is done since the results obtained with axial friction activated gave less credible results, as the simulations indicated that the static axial force distribution was changed with increased number of turnpoints. Given that the pipe is assumed laid at a constant water depth, deactivating the axial friction can be justified. The reason is that the constant water depth gives rise to a stable departure angle, and thus an approximately constant tension in the pipe during laying.From the static results, it is found that introducing more turnpoints along the route resulted in a flattening of the equivalent moment-curve. This makes sense, since the distance between the turnpoints is reduced. In the same manner, the contact force between the turnpoints and the pipeline gets reduced, as the force is more distributed and shared between additional supports. It is further noted that both the contact force and the moment is symmetrically distributed over the pipeline curvature. Based on this, symmetry of the problem could probably be exploited, reducing the size of the model.Several parameter studies have been carried out in order to obtain the overall worst case results. Based on the parameter study, the dynamic analysis was set up. The following parameters have been applied in the dynamic analyses:- A current direction of 90° pushing the pipe towards the turnpoint- A touchdown position right behind the last turnpoint.\\- A wave heading of 45°from behind on the vessel, introducing both roll and pitch motion. With a significant wave height of HS = 2.5 [m] and a wave period of TP = 7 [s].The dynamic analysis has been carried out during a 3-hour sea state, prescribed by the Jonswap-spectrum. In order to reduce the computational time running the analyses, the worst response during the sea state was found, and then all the analyses was carried out in a short time interval, based on the most critical time.The dynamic tension in the pipeline increases as more turnpoints are installed, i.e. the system gets stiffer. As the system gets stiffer with more turnpoins installed, the contact force between the turnpoints and the pipeline is actually at its lowest when only 3 turnpoints are installed. This can be explained by the increase of tension in the pipeline. A stiffer system gives higher dynamic response. As far as the moment distribution is concerned, the same applies as for the static analyses, i.e. the moment gets reduced when the number of turnpoints is increased.A local buckling check has been performed in order to control the results against DNV's standard for local buckling. It is found that neither 3 nor 4 turnpoints along the route is sufficient to satisfy the local buckling criteria. Hence, 5 or more turnpoints must be installed. In addition to this criteria, the turnpoints used in the case investigated have a geotechnical capacity of 80 [kN]. The contact force between the turnpoint and pipe must therefore be kept below this capacity.As the turnpoints are installed with a certain turnpoint tolerance, an analysis investigating the effect of such tolerance has been performed. As the tolerance was set to 0.5 [m] in the lateral direction, there was an increase in the contact forces, the moment and the tension in the pipeline. The contact force remained within the geotechnical limitations of the turnpoints utilized. However, the results showed that 5 turnpoints along the curvature is not sufficient to fulfil the local buckling criteria. Hence, installation of 6 turnpoints is proposed. This is lower than the originally 10 turnpoints that have been installed for the case investigated. Hence, the method utilized by Subsea 7 is found to be over-conservative.In order to create a picture of how the turnpoint tolerance affects the results, an analysis has been carried out for 1 [m] lateral tolerance as well. This resulted in a significant increase of moments and contact force between the pipe and the turnpoints. Furthermore, the local buckling utilization is considerably increased when the tolerance is as high as 1 [m] in the lateral direction. It is evident that the turnpoint tolerance is of high importance. Keeping the tolerance as low as possible is essential in order to install as few turnpoints as possible.

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Ebejer, Neil. „Development and application of pipet-based electrochemical imaging techniques“. Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/53742/.

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This thesis describes the development of an electrochemical scanned probe microscope, SECCM, outlining the need for such a development, by highlighting previous techniques and their limitations. SECCM consists of a double barrel capillary pulled to small dimensions, filled with electrolyte solution and a redox mediator of choice, with a QRCE is inserted into each channel. A potential is applied between the QRCEs, whilst modulating the pipet normal to the surface. The probe is translated towards the surface and once contact is established, a modulation in the ion current arises due to the physical oscillation of the probe, which is then used as a feedback parameter for imaging. The potential at the working electrode substrate is also controlled. SECCM is introduced using a model test substrate, gold bands on glass, showing that the probe is able to track topographical features, making simultaneous electrochemical measurements. Ion conductance measurements between the two QRCEs, are shown to be sensitive to the nature of the substrate investigated. The fundamental electrochemical behaviour of CVD graphene and SWNT is investigated. A multimicroscopy approach is used for CVD graphene studies, correlating surface structure and activity, deducing heterogeneous electron transfer kinetics through simulation. The SWNT samples are studied in two different morphologies: as 3D forests; and, as a 2D network. In the forests, the probe is positioned at the ends and sidewalls, making spot measurements. The voltammetric behaviour shows very similar responses, whilst in the network, a nanosized probe is scanned across the surface, showing relatively uniform activity across an entire tube. These new insights indicate that SWNTs are highly active electrode materials. The fabrication and characterisation of SECM-SICM probes, in a straightforward manner is also presented. These types of probes were found to be ideal for the investigation of biological samples, being extremely easy and quick to fabricate.

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Sant, Shachi. „Field evaluation of a multi chamber pipe device for storm water treatment“. Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1177091216.

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Backfish, Michael. „Electron Cloud in Steel Beam Pipe vs Titanium Nitride Coated and Amorphous Carbon Coated Beam Pipes in Fermilab's Main Injector“. Thesis, Indiana University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1537196.

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This paper documents the use of four retarding field analyzers (RFAs) to measure electron cloud signals created in Fermilab's Main Injector during 120 GeV operations. The first data set was taken from September 11, 2009 to July 4, 2010. This data set is used to compare two different types of beam pipe that were installed in the accelerator. Two RFAs were installed in a normal steel beam pipe like the rest of the Main Injector while another two were installed in a one meter section of beam pipe that was coated on the inside with titanium nitride (TiN). A second data run started on August 23, 2010 and ended on January 10, 2011 when Main Injector beam intensities were reduced thus eliminating the electron cloud. This second run uses the same RFA setup but the TiN coated beam pipe was replaced by a one meter section coated with amorphous carbon (aC). This section of beam pipe was provided by CERN in an effort to better understand how an aC coating will perform over time in an accelerator. The research consists of three basic parts: (a) continuously monitoring the conditioning of the three different types of beam pipe over both time and absorbed electrons (b) measurement of the characteristics of the surrounding magnetic fields in the Main Injector in order to better relate actual data observed in the Main Injector with that of simulations (c) measurement of the energy spectrum of the electron cloud signals using retarding field analyzers in all three types of beam pipe.

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Abdel-Aal, Mohamad. „Modelling the Viability of Heat Recovery from Underground Pipes. Deterministic modelling of wastewater temperatures in a 3000 sewer pipe network“. Thesis, University of Bradford, 2015. http://hdl.handle.net/10454/14467.

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Modelling wastewater temperature variations in a network of 3048 sewer pipes was achieved in this project. Recovering heat from sewers presents attractive options for producing clean energy. However, heat recovery from sewerage may result in wastewater temperature drops which may reduce the influent temperature at the wastewater treatment plant (WWTP). This drop in the WWTP influent temperature may result in the degradation of the biological treatment stage. Therefore, it is vital to predict the impact of recovering heat from sewers on the wastewater temperature. Sewer temperatures along with hydraulic data were measured for up to a year in four different Belgian sites. The measured data was utilised to calibrate a deterministic sewer pipe model that estimates the wastewater temperature variation along the sewer pipe profiles. The latter model was calibrated using data from two sites and then validated using independent data from the other two sites. The sewer pipe model was then further developed to model wastewater temperature variations in a large (3048 pipe) network. The large network model was tested by implementing three different heat recovery scenarios. It was observed that 9 MW may be recovered from the 3048 pipe network, serving a catchment with a population equivalent of 79500 inhabitants, without impacting negatively on the biological processes.

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Mindel, Scott A. „Design of Experimental Facility to Simulate Pulsating Flow Through a Blockage“. University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307457366.

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White, S. D. Davey Peter Higgins David A. „The dynamics of regionalisation and trade : Yorkshire clay tobacco pipes c1600-1800 /“. Oxford : Archaeopress, 2004. http://catalogue.bnf.fr/ark:/12148/cb392793023.

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Lock, Olga, und Rosario Rojas. „Química y Farmacología del Piper aduncum L. ("Matico")“. Revista de Química, 2017. http://repositorio.pucp.edu.pe/index/handle/123456789/100459.

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La presente publicación pretende resumir el conocimiento científico químico-biológico sobre el Piper aduncum L., y sus especies sinónimas, P. angustifolium y P. elongatum. Se han logrado aislar e identificar más de 50 compuestos en dichas especies, los cuales pueden ser agrupados en cromenos, fenilpropanoides, derivados de ácido benzoico y flavonoides. Se presenta una discusión de las actividades biológicas encontradas para los extractos crudos y los compuestos aislados de ellos.
This review article covers the present knowledge on the chemistry and biological activities of Piper aduncurn and its synonyms P. angustifoliurn and P. elongaturn. More than 50 compounds have been isolated from these species, which can be grouped as chromenes, phenylpropanoids, benzoic acid derivatives and flavonoids. The biological activities of the crude extracts, and the compounds isolated from them, are discussed.

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GRÖNKVIST, EMIL. „New bore pipe connection for Slotborer“. Thesis, KTH, Maskinkonstruktion (Inst.), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-192185.

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Slotborer är benämningen på en ny maskinprototyp som skall användas för att i gruvor borra och utvinna platina. För att erhålla ett visst borrdjup skarvas borrpipor vilket åstadkoms med en gängkoppling. Detta arbete har haft som syfte att utveckla en ny koppling för dessa pipor då konstruktionen med gängor har visat sig vara problematisk. Ett antal koncept genererades varefter det mest lovande, enligt diskussion med kund och Pughs beslutsmatriser, valdes för vidareutveckling. Detta valda koncept var en typ av bajonettkoppling som förfinades och det gjordes en 3D CAD-modell samt mer detaljerade analyser av kopplingens hållfasthet. Analytiskt med grundläggande hållfasthetslära visades kopplingens mest påkända delar ha Von Mises effektivspänningar på 230 MPa vid normal borrning, 360 MPa vid maxeffektsborrning och 605 MPa vid dragande borrning med maxeffekt. Kontakttryck i kopplingen analyserades enligt Hertz kontaktteori och uppgick i maximalt 2,6 GPa, 3,3 GPa och 4,5 GPa för respektive lastfall. En FEM-analys gjordes där lokala effektivspänningar upptäcktes vara i storleksordningarna 300 MPa, 500 MPa och 1200 MPa för respektive lastfall. Konceptutvecklingen och analysen pekar på att konstruktionen är lämplig för vidare detaljerad konstruktion.
Slotborer is a new machine prototype that is used for excavating platina in underground mines. To drill holes with desired depths there are several drill pipes that are bonded as the hole is drilled deeper with a threaded connection. This work have had the purpose of designing a new connection for these drill pipes as the thread design have shown to be problematic. A number of concepts were generated after which the most preferred, according to customer discussions and Pugh decision matrices, was chosen for further development and refinement. The chosen concept for development was a type of bayonet coupling and a more detailed 3D CAD model and analysis of the coupling strength were made. Analytical solid mechanics showed that the most heavily loaded parts of the coupling experienced effective Von Mises stresses of 230 MPa for normal drilling, 360 MPa for heavy drilling and 605 MPa for heavy back reaming. Contact pressures were analyzed with Hertzian contact theory and the maximum values of these were shown to be 2.6 GPa, 3.3 Gpa and 4.5 GPa for the respective load cases. An FE analysis made showed higher local effective stresses that was of the magnitude of 300 MPa, 500 MPa and 1200 MPa for the respective load cases. The conclusion of the concept development and analysis points out that the design is suitable for further detailed design.

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Pinto, Danielle Serafim. „Estudo fitoquímico de piperaceas do norte e nordeste brasileiro: Piper lateripilosum Yuncker, Piper montealegreanum Yuncker, Piper mollicomum Kunth“. Universidade Federal da Paraíba, 2012. http://tede.biblioteca.ufpb.br:8080/handle/tede/6727.

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The genus Piper is the largest in the family Piperaceae, with at least 1,000 species distributed particularly in the Neotropical region, where about two thirds of the described species can be found. It is a genus commercially important and with many medical applications. The phytochemical investigation of species of this genus which is so rich in metabolites and has widespread use in folk medicine, besides its various biological activities reported in the literature, can open exciting perspectives for the chemistry, pharmacology and chemotaxonomy. This work reports the phytochemical study of three species of Piper, aiming at the isolation and identification of their chemical constituents as well as the pharmacological evaluation of extracts, fractions and isolated compounds. Through usual chromatographic methods and spectroscopic techniques such as IR and one- and two-dimensional 1H and 13C NMR techniques and comparison with literature data it was possible to isolate and identify five amides and two steroids from the aerial parts of Piper lateripilosum collected in Amapá, all of them isolated for the first time in this species. From Piper mollicomum collected in Paraíba were isolated a new amide and a coumarin of the hexane and chloroform phases of the crude ethanol extract of the leaves, respectively, and a benzoic acid derivative and a aristolactam of the chloroform phase obtained from the crude ethanol extract of the stem of this species. The amide is first reported in the literature, the coumarin for the first time in the genus and the benzoic acid derivative and the aristolactam for the first time in this species. From Piper montealegreanum collected in Belém-PA it was possible to isolate a new chalcone, 3 -methoxy,3,4 ,6 -trihydroxy, 2 ,5 -dimethylchalcone, and reisolate the flavonoids 8-formyl-3 ',5-dihydroxy-7-methoxy-6-methylflavanone; 3 '-formyl-3, 4', 6'-trihydroxy-2- methoxy-5-methylchalcone and (2'-methoxy-3'-formyl-4', 6'-dihydroxy-5'-methyl phenyl) - [3''-(dimethylbut-6''-enyl)- 7- phenyl-(3-hydroxy) -cyclohex-2''-enyl]-methyl-9-one. The extracts, some phases and substances isolated from the species studied were submitted to investigation of antimicrobial and hemolytic activities, and modulator of resistance to antibacterial drugs.
O gênero Piper é o maior da família Piperaceae, com pelo menos 1000 espécies distribuídas especialmente na região Neotropical, onde cerca de dois terços das espécies descritas são encontradas. É um gênero com boa representatividade comercial e muitas aplicações medicinais. A investigação fitoquímica de espécies deste gênero, de tão grande riqueza metabólica e de vasta utilização pela medicina popular, além de suas várias atividades biológicas citadas na literatura, pode abrir perspectivas para a química, farmacologia e quimiotaxonomia. Este trabalho relata o estudo fitoquímico de três espécies de Piper, visando o isolamento e identificação de seus constituintes químicos, bem como a disponibilização de seus extratos, frações e substâncias isoladas, para realização de estudos farmacológicos. Utilizando-se métodos cromatográficos convencionais e técnicas espectroscópicas de IV e RMN de 1H e 13C uni e bidimensionais e a comparação dos dados com a literatura foi possível isolar e identificar das partes aéreas de Piper lateripilosum, coletada no Amapá, cinco amidas e dois esteróides todos isolados pela primeira vez nesta espécie. Da espécie Piper mollicomum, da Paraíba, foram isoladas uma nova amida e uma cumarina, das respectivas fases hexânica e clorofórmica do extrato etanólico bruto das folhas, além de um derivado do ácido benzóico e de uma aristolactama obtidos da fase clorofórmica do caule desta espécie. A amida está sendo relatada pela primeira vez na literatura, a cumarina pela primeira vez no gênero e o derivado do ácido benzóico e a aristolactama pela primeira vez nesta espécie. Das partes aéreas de Piper montealegreanum, coletada em Belém PA, foi possível isolar uma nova chalcona, a 3 -metoxi,3,4 ,6 -triidroxi, 2 ,5 -dimetilchalcona, bem como reisolar os flavonóides 8-formil-3 ,5-diidroxi-7-metoxi-6-metilflavanona; 3 -formil-3,4 ,6 -triidroxi-2 - metoxi-5 -metilchalcona e (2 -metoxi-3 -formil-4 ,6 -dihidroxi-5 -metilfenil)-[3 - (dimetilbut-6 -enil)-7-fenil-(3-hidroxi)-ciclohex-2 -enil]-metil-9-ona. Os extratos e algumas fases e substâncias isoladas foram disponibilizadas para a investigação da atividade antimicrobiana, hemolítica e moduladora da resistência à drogas antibacterianas.

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Haupt, William. „Ensaios mecânicos e caracterização microestrutural de tubos soldados por fricção“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/76163.

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O presente trabalho avalia a evolução das microestruturas e das propriedades mecânicas em tubos API 5L X65 soldados por fricção com auxílio de um anel centralizador na posição de topo. A soldagem foi realizada em tubos de 114,3 mm (4,5’’) de diâmetro nominal e 8 mm de espessura. A avaliação mecânica foi realizada segundo normas ASTM para os ensaios de tração, dobramento de raiz, dobramento de face, ensaio de impacto Charpy V e perfis de microdurezas. Os ensaios de fadiga foram realizados para análise da vida em fadiga das juntas soldadas. Os ensaios mecânicos realizados comprovam que houve a união metalúrgica dos materiais, sendo registradas regiões com defeitos de falta de adesão o que prejudicou as propriedades mecânicas ocasionando rupturas com baixa ductilidade nas interfaces de soldagem nestes locais. Nos resultados dos ensaios de microdurezas houve um pequeno aumento das microdurezas registradas próximo às interfaces de soldagem e uma redução nas microdurezas registradas nas regiões de ZACs. Os resultados do ensaio de impacto Charpy -20 °C foi aceitável segundo a norma API 5L. As microestruturas formadas nas interfaces de soldagem são compostas por ferrita de Widmanstätten e ferrita poligonal com crescimento de grão quando comparado com o tamanho de grão do material de base. Nas regiões de ZACs houve um reordenamento de carbonetos aliado a refino de grão sendo registrada uma redução nas microdurezas destas regiões.
This paper assesses the evolution of microstructures and mechanical properties in pipes API 5L X65 welded by friction with the aid of centering ring on top position. The welding was performed in tubes of 114.3 mm (4.5'') nominal diameter and 8 mm in thickness. The mechanical evaluation was performed according to ASTM standards for tensile, root bending, face folding, Charpy V impact test and microhardness profile. Fatigue tests were performed to analyze the fatigue life of the welded joints. The mechanical tests prove that there was a metallurgical union of the materials, regions with lack of adhesion defects being recorded which affected the mechanical properties causing fractures with low ductility in the weld interfaces in these places. Microhardness test results registered a small increase in the microhardness near the weld interfaces and a reduction in the microhardness recorded in the HAZ regions. The results of the Charpy impact test at -20°C was acceptable according to API 5L. The microstructures formed at the weld interfaces are composed of Widmanstatten ferrite and polygonal ferrite with grain growth when compared to the grain size in the base material. In HAZ regions there was a reorganization of carbides combined with grain refinement, with a reduction in microhardness of these regions being registered.

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Gustavsson, Elin. „Järnets förekomst i grundvattnet i isälvsavlagringar i Dalarna : Bakgrundshalter och rörmaterialets inverkan vid grundvattenprovtagning“. Thesis, Uppsala University, Department of Earth Sciences, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-88837.

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A study has been performed that investigates the variation of iron content in groundwater.

The study was initiated by Midvatten AB, which noticed that the iron content in groundwater samples can vary greatly over small distances. The purpose of this study was to geochemically and geohydrologically determine the factors that influence the content of iron and manganese in groundwater from a selection of eskers in Dalarna, and determine how to best sample groundwater with the method used by Midvatten AB. An evaluation was made of how the vertical variation in soil material, water composition, pumping time and pipe material affects the content of iron in groundwater. Piper diagrams were used to study the relationship between the chemical composition of the groundwater and the content of iron and manganese in groundwater samples from the studied areas. The groundwater from the studied areas was then classified in the Piper diagrams, according to the content of the major ions. Correlations were then studied between the classification and depth below groundwater table, depth below ground surface, pH, iron- and manganese content.

Field samples were collected from Lennheden in order to investigate the effect of vertical variations of soil material, pumping time and pipe material on the content of iron and manganese. This was also performed to evaluate the best way of sampling groundwater. The groundwater was sampled from a steel pipe and a plastic pipe. Redox potential, pH, dissolved oxygen, iron content, temperature in groundwater, turbidity and conductivity were measured for different depths and pumping times in field.

Also a groundwater sample from every sampling depth was sent to a laboratory for analysis. Diagrams and correlation tables were used to analyze these results. No correlation between iron and the major ions in groundwater was found in the Piper diagrams, but the content of manganese in groundwater had a tendency to increase with increasing alkalinity. The results from sampling groundwater showed that the average content of iron in groundwater was 0,11 mg/l from the steel pipe and 0,01 mg/l from the plastic pipe. Turbidity has the greatest effect on the analyzed content of iron in groundwater, thus the turbidity needs to be zero while sampling. A suggestion is that while investigating groundwater quality in large areas, iron pipes can be used. When the best place is located, plastic pipes can be used when the iron content needs to be investigated in detail.

Då företaget Midvatten AB har märkt att järnhalten vid provtagning av grundvattnet kan variera stort på små områden har en studie av järnhaltens variation i grundvattnet utförts.

Syftet var att geokemiskt och geohydrologiskt bestämma de faktorer som påverkar järn- och manganhalten i grundvattnet i ett urval isälvsavlagringar i Dalarna, samt att bestämma hur man bäst ska provta grundvatten med Midvattens AB:s provtagningsmetodik. Studien skulle då utvärdera hur de vertikala variationerna i jordmaterial, vattensammansättning, pumptid och hur rörmaterialet påverkar järn- och manganhalten i uppumpat grundvatten. För att studera sambandet mellan den kemiska sammansättningen i grundvattnet och järn- och manganhalten analyserades flera tidigare insamlade data på grundvattenprov från de studerade lokalerna i Piperdiagram. I Piperdiagrammet klassificerades grundvattenproverna till en hydrokemisk typ med hjälp av sammansättningen av de vanligaste jonerna. Samband söktes mellan klassningen av grundvattenproverna och det uttagna provets djup under grundvattenytan, det uttagna provets djup under markytan, pH, järn- och manganhalt i brunnen.

Vid undersökning av hur de vertikala variationerna i grundvattnet, pumptiden och rörmaterialet påverkade järnhalten i grundvattnet togs flera grundvattenprover i fält i Lennheden. Detta gjordes även för att utvärdera bästa tillvägagångssätt vid provtagning av grundvattnet. Grundvattnet pumpades upp i vardera ett stålrör och ett plaströr. Redoxpotential, pH, syrgashalt, järnhalt, temperatur i vattnet, turbiditet och konduktivitet mättes vid olika djup och pumptider. Prov för varje provtagningspunkt skickades in till laboratorium för analys. Resultaten av dessa analyser undersöktes därefter i diagram och korrelationstabeller. I Piperdiagrammen märktes inget samband mellan järn och grundvattnets vanligaste joner, men manganhalten tenderade att öka med ökad alkalinitet. När grundvattnet provtogs i fält var medelhalten på järn 0,11 mg/l från ett stålrör och 0,01 mg/l från ett plaströr. Det tyder på att stålröret bidrog till en högre järnhalt i grundvattnet. Den parameter (förutom stålröret) som visade störst påverkan på analysresultatet av järn i laboratorium var turbiditeten. Således behöver turbiditeten i fält vara noll vid provtagning av järn till laboratorium. Förslagsvis kan stålrör användas vid övergripande undersökning av grundvattenkvalité. Plaströr kan sedan användas vid detaljerad undersökning av järnhalten i grundvattnet när bästa plats valts.

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David, Andréia Márcia Santos de Souza. „Maturação de sementes de milho-pipoca“. Universidade Federal de Viçosa, 2002. http://www.locus.ufv.br/handle/123456789/10197.

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O experimento teve como objetivo estudar o processo de maturação de sementes de milho-pipoca. Em uma área de 780 m2 foram plantadas sementes de milho-pipoca DFT 2 (ciclo de seleção 2). A primeira colheita das sementes (23/01/01), foi realizada em torno de 30 dias após a floração plena (23/12/00), considerada quando aproximadamente 50% das plantas apresentavam florescimento feminino. As demais colheitas foram realizadas de 7 em 7 dias, até as sementes atingirem, aproximadamente, 12% (b.u.), o que ocorreu na 10a colheita (27/03/01). Imediatamente após cada colheita, procedeu-se à debulha manual das sementes, determinando o seu grau de umidade e o peso da matéria seca; avaliou-se também, visualmente, a presença da camada preta. O restante das sementes nas espigas foi submetido à secagem em estufa com ventilação forçada, a aproximadamente 30oC, até atingirem umidade de aproximadamente 12%, quando as sementes foram debulhadas manualmente e acondicionadas em sacos de papel e armazenadas em câmara fria (10oC + 2 e 75% UR + 5). Após a última colheita, as sementes foram submetidas ao expurgo e, em seguida, retornaram para a câmara fria, para posteriores avaliações quanto à retenção em peneiras, germinação e vigor. As sementes achatadas, retidas nas peneiras de crivo redondo 13, 14 e 15/64”, foram misturadas para avaliações nos testes de qualidade fisiológica (testes de germinação, primeira contagem, frio modificado, envelhecimento acelerado e condutividade elétrica). As análises estatísticas foram realizadas, utilizando-se o programa SAEG. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições por tratamento (épocas de colheita). Os resultados permitiram concluir que as sementes de milho-pipoca, variedade DFT-2, atingiram o máximo de matéria seca (maturidade de massa) aos 68 dias após a floração, sendo que a maturidade fisiológica das sementes (máximo de germinação e vigor) ocorreu no período de 62 a 68 dias após a floração. As sementes apresentavam teor de água na faixa de 17 a 20%, por ocasião da maturidade fisiológica e maturidade de massa. A camada preta mostrou-se como uma característica visual eficiente para identificação da maturidade fisiológica das sementes de milho-pipoca. As sementes de milho- pipoca mostraram-se pouco suscetíveis à deterioração no campo causada pelas condições climáticas, por ocasião do retardamento da colheita.
The objective of this study was to analyze the maturation process of the popcorn seeds. Some seeds of the popcorn DFT 2 (selection cycle 2) were sown on a 780m2 area. At approximately 30 days after full blooming (December 23, 2000), when about 50% plants exhibited feminine flowering, the first harvest of the seeds was accomplished. The other harvests were accomplished at 7- day intervals until seeds reaching approximately 12% (wet basis), which occurred upon the 10th harvesting. (March 27, 2001). Just after each harvest, the seeds were manually husked, by determining their moisture content and the weight of the dry matter. Also the development of the black layer was visually evaluated. The seeds remaining in the ears were submitted to the drying process at approximately 30o C in a mechanic air-forced oven until attaining a moisture content about 12%. Then, they were manually husked, conditioned into paper bags and stored in cold chamber (10oC ± 2 and 75% RH ± 5). After the last harvesting, the seeds were expurgated, and then they were returned to the cold chamber in order to be evaluated for retention on sieves, germination and vigor. The seeds retained on the round-opening sieves of 13, 14 and 15/64 in. were mixed in order to be submitted to the evaluating tests for physiological quality (germination, first counting, modified cold, accelerated aging and electric conductivity tests). The statistical analysis were accomplished, by using the SAEG program. The entirely randomized experimental design was used with four replicates for each treatment (harvesting times). The results allow to conclude that the popcorn seeds, cultivar DFT-2, reached the maximum dry matter weight (mass maturity) based on the 68th day after flowering, whereas the physiological maturity of the seeds (maximum germination and vigor) occurred over the period from 62 to 68 days after blooming. Upon the physiological maturity and mass maturity, the seeds showed a moisture content ranging from 17 to 20%. The black layer showed to be an efficient visual characteristic for identifying the physiological maturity of the popcorn seeds. The popcorn seeds showed little susceptibility to deterioration in the field, which is caused by the climatic conditions upon the harvesting delay.

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Su, Yuming. „Storm water runoff treatment with multi-chamber pipes“. Ohio : Ohio University, 2002. http://www.ohiolink.edu/etd/view.cgi?ohiou1177524622.

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Odhekar, Dhananjay Dilip. „Experimental investigation of bendable heat pipes“. Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Summer/master's/ODHEKAR_DHANANJAY_40.pdf.

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Suh, Junwoo. „Proof of Operation in a Planar Loop Heat Pipe (LHP) Based on CPS Wick“. University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1131033062.

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Vishwakarma, Anmol. „Development Of A Performance Analysis Framework For Water Pipeline Infrastructure Using Systems Understanding“. Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/87081.

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The fundamental purpose of drinking water distribution systems is to provide safe drinking water at sufficient volumes and optimal pressure with the lowest lifecycle costs from the source (treatment plants, raw water source) to the customers (residences, industries). Most of the distribution systems in the US were laid out during the development phase after World War II. As the drinking water infrastructure is aging, water utilities are battling the increasing break rates in their water distribution system and struggling to bear the associated economic costs. However, with the growth in sensory technologies and data science, water utilities are seeing economic value in collecting data and analyzing it to monitor and predict the performance of their distribution systems. Many mathematical models have been developed to guide repair and rehabilitation decisions in the past but remain largely unused because of low reliability. This is because any effort to build a decision support framework based on a model should rest its foundations on a robust knowledge base of the critical factors influencing the system, which varies from utility to utility. Mathematical models built on a strong understanding of the theory, current practices and the trends in data can prove to be more reliable. This study presents a framework to support repair and rehabilitation decisions for water utilities using water pipeline field performance data.
Master of Science

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Giacobbi, Dana. „The dynamics of aspirating cantilevered pipes and pipes conveying variable density fluid“. Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95074.

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This thesis undertakes the investigation of the dynamics of two different cases of a slender, flexible pipe conveying fluid: (i) an aspirating cantilevered pipe, ingesting fluid at its free end and transporting it towards the clamped end, and (ii) a pipe conveying a fluid whose density varies axially along the length of the pipe. The general context of the research is first provided by broadly introducing the field of Fluid-Structure Interactions (FSI) and reviewing the basic theory regarding pipes conveying fluid. Subsequently, a numerical approach coupling Computational Fluid Dynamics (CFD) and Computational Structural Mechanics (CSM) to simulate each system is developed in ANSYS. Lastly, the linear equation of motion is derived for each system and solved using a Galerkin approach; the numerical experiments are then combined with these analytical results to determine the stability characteristics of each system. The problem of an aspirating cantilevered pipe is of both fundamental and practical interest, with applications, for example, in deep sea ocean mining. The motivation for a continued study of the system is demonstrated through a review of previous research on the topic spanning many years and yielding often contradictory results. The newly proposed analytical model, derived using a Newtonian approach and heavily influenced by CFD analysis, is different from previous ones, most notably because of the inclusion of a two-part fluid depressurization at the intake. In this case, the combined numerical and analytical approaches suggest a first-mode loss of stability by flutter albeit a very weak one at comparable but usually lower flow velocities than the discharging cantilever. In the case of a pipe conveying variable density fluid, the analytical model is derived using a Hamiltonian approach, for (i) a pipe clamped at both ends and (ii) a cantilevered pipe. It is shown that these systems lose stability by buckling and flutter respectively, simi
Cette thèse entreprend l'étude de la dynamique de deux types de tuyaux flexibles parcourus par un fluide : (i) un tuyau encastré-libre aspirant le fluide du côté libre et l'amenant vers le côté encastré, et (ii) un tuyau transportant un fluide dont la densité varie axialement au long du tuyau. Le contexte général de cette recherche est d'abord présenté en introduisant le domaine des Interactions fluide-structure (FSI) et en révisant la théorie de base des tuyaux transportant un fluide. Par la suite, une approche numérique couplant la simulation des fluides (CFD) et des structures mécaniques (CSM) est développée dans ANSYS. Dernièrement, une équation de mouvement linéaire est dérivée pour chaque système et analysée par une méthode Galerkin; les résultats numériques sont enfin combinés avec ces résultats analytiques pour déterminer les caractéristiques de stabilité de chaque système. Le tuyau encastré-libre aspirant est d'un intérêt fondamental et aussi pratique, possédant des applications, entre autres, dans l'industrie minière sous-marine. La raison d'une étude poursuivie est démontrée par un retour sur la recherche antérieure traitant du sujet s'étendant sur plusieurs années et produisant souvent des résultats contradictoires. Le nouveau model analytique, dérivé utilisant une approche Newtonienne et largement influencé par une analyse CFD, se distingue de ses prédécesseurs notamment par l'inclusion d'une dépressurisation en deux parties à l'entrée. Pour ce cas, les approches numérique et analytique suggèrent tous les deux une perte de stabilité par flottement dans le premier mode quoiqu'une instabilité très faible à des vitesses comparables, mais généralement moindre que le cas déchargeant. Dans le cas d'un tuyau transportant un fluide de densité variable, le modèle analytique est dérivé à l'aide d'une approche Hamiltonienne, pour des tuyaux (i) encastré-encastré et (ii) encastr

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Iorio, Luis Carlos. „Redes de comunicação em automação industrial enfase na solução tecnologica da plataforma pipefa“. [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265321.

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Orientador : João Mauricio Rosario
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: Neste trabalho, procurou-se estudar a aplicação das redes de comunicação em automação, industriaL como uma segunda solução para a plataforma PIPEFA, que foi projetada com sistema convencional. No trabalho são comparados esse sistema com o Fieldbus, uma tecnologia de ponta em pleno desenvolvimento, nas indústrias, nos centros de pesquisas, por estar causando uma revolução na automação. É necessário conhecer as tecnologias de automação e seus elementos. Os resultados deste trabalho são da maior importância, é imprescindível para a atualização do conhecimento tecnológico, no ensino e dos usuários, no sentido de conhecerem a tecnologia que esta diferenciado a automação e sua competitividade. A experiência,tem demonstrado que as empresas e profissionais que relutam em acompanhar as evoluções são deixados para trás. Desta forma, também teremos a possibilidade em darmos continuidade aos objetivos idealizados pelos criadores da plataforma, pelo aprimoramento, atualização dos conhecimentos tecnológicos, de uma massa crítica de pesquisadores no domínio da Engenharia de Automação Integrada que utilizam a plataforma como base de pesquisa
Abstract: In this work, it tried to study the networks in automation industrial, as a second solution for the platform PIPEF A, that was going projected with conventional system. At work are compared this system with Fieldbus, a top development technology, in the industries, in the researches centers, for being causing a revolution in the automation. It is necessary to know the automation technologies and your elements. The results of this work are of major importance, it is essential for the technological knowledge update, in the teaching and of the users, in the meaning of knowing the technology that is differentiated the automation and your competitiveness. The experience, it has been demonstrating that the companies and professional that resist in accompany the evolutions are let back. Thus, will also have the possibility in give continuity to the goals idealized by the platform creators, by the refinement, technological knowledges update, of a critical mass of searching in the Engineering Integrated Automation domain that use the platform like research base
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica

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Kalra, Rajesh. „Structural performance of jointed plastic pipes under a simulated high landfill“. Ohio : Ohio University, 1994. http://www.ohiolink.edu/etd/view.cgi?ohiou1177532510.

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Lundgren, Paulina, und Anton Torstensson. „Rena rör : Clean pipes“. Thesis, Växjö University, School of Technology and Design, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-2653.

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In this project a washing station has been constructed for Albany International AB. At present, there is no existing system to clean the dirty pipes that are coming back to the company.

The work followed the product development process, and it started with the requirements list. This was followed by brainstorming, evaluation and completion.

The result was a concept for de present time and one concept for the future.

The present concept is intended to be built immediately. This is an adjustable bench with sliding bearings to facilitate the work. The actual cleaning is done with a high pressure washer that uses hot water. When the future concept will be brought into use, you don’t need to modify or rebuild anything, just add to the constructions that already exist. The future is to increase efficiency and become even more environmentally friendly.

The concept also includes two types of warehouses, one for the dirty pipes, and one for the clean pipes. On these you are supposed to place several pipes, so it’s possible to streamline processing, and wash more pipes in a flow.

The washing station will lead to improvement of the working environment, and the new technology will make improvements on the result.

I detta arbete har en tvättstation konstruerats åt företaget Albany international AB. I dagsläget finns inget befintligt system för att tvätta smutsiga returrör.

Arbetet följde produktutvecklingsprocessen, och började med en kravspecifikation. Därefter följde brainstorming, utvärdering och färdigställande.

Resultatet blev ett nutidskoncept och ett framtidskoncept. Nutidskonceptet är tänkt att det skall byggas omgående. Detta är en ställbar tvättbänk med kulhus för att underlätta arbetet. Själva rengöringen sker med en högtryckstvätt som använder varmvatten. När framtidskonceptet skall tas i bruk behöver företaget inte ändra eller bygga om någonting, utan bara göra tillägg i den konstruktion som redan finns. Framtidsvisionen handlar om att öka effektiviteten och samtidigt bli ännu mer miljövänlig.

I konceptet ingår det även två typer av magasin, ett för de smutsiga rören, och ett för de rena rören. På dessa ska man kunna lägga flera rör, så att man ska kunna effektivisera bearbetningen och tvätta fler rör i ett flöde.

Tvättstationen ska leda till att arbetsmiljön blir bättre, och den nya tekniken gör att resultatet förbättras.

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Luo, Renfan. „Fatigue of dented pipes“. Thesis, University of Nottingham, 2002. http://eprints.nottingham.ac.uk/13984/.

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A dented pipe fails either through being punctured or by fatigue damage accumulation due to internal pressure fluctuation. Increasing the wall thickness may prevent these failures but is impractical. As a pipe is punctured, transmission services must be cut off and repair processes have to be made immediately. However, when a dent depth is not large enough to puncture the pipe, the pipe can safely continue in service for a long time until a fatigue crack initiation occurs. Therefore, the fatigue life assessment has attracted much attention in the pipe industries for economic and safety reasons. The severe tensile residual stress concentration and the large plastic strain deformation in the dented region are the main causes of the pipe failure due to fatigue damage. Accurate calculation and prediction of the residual stress and variations resulting from internal pressure fluctuation can lead to safety assessments and prediction of the remaining life of the dented pipe. Due to the complex nature of the contact process, the deformed pipe geometry and the elastic-plasticity, analytical approaches are incapable of obtaining stress solutions. Therefore, FE modelling is employed in the present work. Experimental tests are employed to investigate the indenter force-dent depth behaviour which can be compared with the FE solutions to confirm and validate the FE models. The rigid perfect elastic-plastic limit load method and an energy-based method are also used to analytically calculate the limit load and the indenter force/deflection relationship of indented rings to predict damage. Two dimensional FE modelling is performed to calculate the contact and residual stress and strain distributions on the outer, inner surfaces and through the wall thickness. These FE solutions show that high stress concentrations occur in the indented region, which give the potential for fatigue damage. As the 2D FE modelling requires only limited resources, the indenter size and indentation position can be changed to analyse their effects on stress and strain distributions in the indented region. This forms the foundation of later 3D FE modelling. Stress sensitivity and the validation of shell models are investigated and confirmed through the 2D and 3D FE modelling and by comparing experimental test data with the FE solutions. Based on this work, the decision is made to use shell element modelling to perform the residual stress and stress range calculations in a 3D pipe. Semi-empirical formulations are developed to predict stress and stress range values if the residual dent depth, the pipe and indenter geometries, material property, internal pressure and pressure range are known. These FE solutions and semi-empirical formulae can be used to calculate the stress range and mean stress.

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Fulford, D. J. „Variable conductance heat pipes“. Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234584.

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Latini, Marco. „Mixing in Curved Pipes“. Scholarship @ Claremont, 2001. https://scholarship.claremont.edu/hmc_theses/129.

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Over the previous summer I studied mixing of a passive tracer by flow in a straight cylindrical pipe, under the supervision of prof. Bernoff. The mixing process can be thought of as the successive action of advection by the fluid flow and diffusion modeled by random walks. With this method we were able to distinguish three different regimes. For short times, diffusion is more relevant than advection and we observed a Gaussian longitudinal distribution of the concentration. In an intermediate regime, advection by the shear is dominant over longitudinal diffusion and we observed a distinctively asymmetric distribution which spread much faster than would be expected by the action of diffusion alone. Finally when the tracer had completely mixed across the pipe’s cross- section, we recovered the classical Taylor regime with a longitudinal Gaussian distribution. In each regime we have analytical prediction of tracer distribution, confirmed by numerical calculation. The object of this thesis is to extend our results to curved pipes; we will start by considering curved planar pipes and helical pipes. We will try to determine if mixing in these geometries displays the same three distinctive regimes of mixing. The pipe’s curvature introduces a secondary flow in the form of a transverse recirculation with a dipolar form, discovered by Dean (1928). We believe this transverse flow should enhance mixing, which explains why curved pipes are used in cooling systems and other situations where heat exchange is relevant. Our object is to first understand existing analytical approximations to the flow in a curved pipe due to Dean and others and then to study analytically and numerically the spread of a passive scalar in these flows.

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Laing, Nicola. „The effect of lead communication pipe replacement on lead levels in low alkalinity drinking water and the analysis of corrosion products formed in pipes“. Thesis, University of Strathclyde, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423880.

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Samsel, Adrian Christopher. „Design of a prototype handheld nanoliter pipette“. Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105677.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 26).
Handheld pipettes are invaluable to scientists in labs across the globe. Due to high inaccuracies at volumes of less than 1 [mu]L, a nanoliter pipette could truly change the way people research. This experimental nanoliter pipette uses a regulating CAM mechanism and a diaphragm to displace small amounts of fluid. The CAM mechanism has the ability to be adjusted to different steps, each of which controls the amount of working fluid to be displaced in a sealed chamber. In response to this, the diaphragm displaces a smaller volumetric amount of fluid outside the chamber. A deamplification ratio is defined by the ratio of the volume displaced by the diaphragm to the volume displaced by the CAM mechanism. The deamplification ratio is adjustable by changing the setting of the variable CAM mechanism or exchanging different tip assemblies which hold different sized diaphragms. In all, this nanoliter pipette enables measuring and dispensing of very small volumes of liquid, ranging from I nL to 1[mu] L, and can expand the tools of every lab researcher internationally.
by Adrian Christopher Samsel.
S.B.

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Givan, Daniel Rey. „Improved operational limits for offshore pipelay vessels“. ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/td/1439.

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Subsea pipelines are used extensively throughout the world’s oceans to transport oil and gas from offshore facilities to land, often hundreds of miles. These pipelines range in diameter from three to sixty inches and are installed in deeper depths every year, currently as deep as 2,900 meters. Pipeline construction and installation costs are a large percentage of offshore projects and thus, methods toward reducing costs is an imperative objective. With pipeline installation projects taking place in harsher environments, vessel operability is vital. This work presents an improved method for determining limiting criteria for pipelay operations to more effectively plan and execute offshore projects. This improvement is based on the consideration of total effective pipeline stresses as the limiting criterion rather than the traditionally used limiting pitch angle. Limiting sea curves based on a sample dynamic pipeline analysis are shown and their incorporation in workability planning is discussed.

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Maley, Jeff. „Slug flow characteristics and corrosion rates in inclined high pressure multiphase flow pipes“. Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1203365261.

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Tori, Wendy P. „Sexual selection in a species with exploded leks the white-crowned Manakin (Pipra pipra) /“. Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2008. http://etd.umsl.edu/r3041.

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Karlsson, Beatrice. „Musiken, pipet och öronproppen : En studie kring ljudnivåernas påverkan och hantering i musikundervisning“. Thesis, Linnéuniversitetet, Institutionen för musik och bild (MB), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-105055.

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Denna, både kvantitativa och kvalitativa, studie har till syfte att undersöka hur hörselkvalitén är hos musiklärare och deras elever på gymnasiet och i folkhögskola, hur musiklärarna och deras elever hanterar och upplever ljudnivåer både i musikundervisningen och privat samt huruvida hörselvård som ämne anammas i musikundervisningen. Studien baseras på en anonym enkätundersökning som utförts på två gymnasieskolor och en folkhögskola om sammanlagt 78 elever och 7 musiklärare. Resultatet redovisar statistik baserad på svarsfrekvens från enkäterna, ger svar på att musiklärarnas och elevernas hörselkvalité är till stor del lägre och flertalet hörselskador i olika former, såsom tinnitus, ljudkänslighet och hörselnedsättning upplevs. Resultatet visar också att hörselvård tas upp till stor grad i musikundervisningen.

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Dissertationen zum Thema „Pipeta“

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