Detta examensarbete har genomförts med anledning av att Norrvatten har önskemål om att få en rapport om de material som används i deras vattenledningsnät med fokus på typiska skador kopplade till ett specifikt material eller tillverkningsmetod. Det har framkommit indikationer om att kunskapen om rörmaterial och dess egenskaper med tiden har försämrats då den äldre generationens projektörer efterlämnat en kunskapslucka efter sig. Syftet med rapporten är att ge en god överblick av materialen i Norrvattens ledningsnät. Det krävs kunskap om materialen för att analysera sambandet mellan läckningsstatistik och materialets egenskaper. Informationshalten varierar mellan de olika materialen. Detta beror framförallt på materialets uppbyggnad och svårighetshalten att redovisa en klar och rättvis bild över dem. Materialen och dess information är uppdelade i kapitel för att underlätta för läsaren att på ett enkelt sätt förstå sammanhangen. Ett annat viktigt kapitel i denna rapport är beskrivningen över de anläggningsmetoder som valdes att tas med, dels markförlagda ledningar men också två schaktfria metoder vilka är infodring och rörspräckning. I verkligheten finns det många fler utbytesalternativ än dem som tas upp i rapporten, men många metoder är snarlika och dem som redovisas tillhör de vanligaste arbetssätten. Detta kapitel är direkt knutet till dimensioneringsverktyget för utbytesmetoderna med avseende på hållfasthet från jordtryck samt trafiklaster, men också dragspänningar som uppstår i framförallt de schaktfria metoderna. Dimensioneringsverktyget består av ett Excel-dokument där användaren med grundläggande parametrar fyller i dokumentet för att sedan få resultat huruvida den nylagda ledningen klarar de påfrestningar som den utsätts för. Baserat på ledningsanvändning mellan olika material och jämföra mot dess skadestatistik vill vi ge en god slutsats om vilket material som vi anser, generellt sett, är lämpligast att använda sig utav. / This thesis has been conducted in response to a request by Norrvatten for an objective report concerning the materials used in their water supply infrastructure, with a focus on the typical damages linked to specific materials or manufacturing processes. Through interviews with well-informed experts we have received indications that the knowledge regarding the materials used in Norrvatten’s water pipes and said materials’ properties have declined over time, as the older generation of construction planners have left behind a knowledge gap. The purpose of the report is to give a good insight into the materials used in Norrvatten’s water supply infrastructure (specifically the pipes used). We claim that a knowledge of the materials used is necessary to analyze the correlation between leakage statistics and the properties of the materials used in the infrastructure. The level of information available varies between the different materials. This is mainly caused by the structure of the material and the difficulty in depicting a clear and objective picture of it. The materials and their information are divided into separate chapters to make it easier for the reader to understand the picture we are trying to create. Another important chapter in this report is the description of the methods of installation we have chosen to work with; these methods are buried pipelines but also two trenchless methods which are lining and pipe bursting. In reality many more methods that the ones described here exist, but many methods are similar and the ones presented here are those that are most commonly used. This chapter is directly linked to our dimensioning model for pipe replacements concerning strength in regard to earth pressure and traffic load, but also the tensile that occur primarily in the trenchless methods. The dimensionality model is constructed as an Excel document where the user – through utilizing some basic parameters – fills out the document and automatically receives results regarding whether or not the new pipes will withstand the stress it is exposed to. Based on the correlation between damage statistics and the use of different materials in the pipe infrastructure we attempt to provide an accurate picture of which materials we deem to be, generally speaking, the most appropriate to make use of.

In North America, cold-formed square and rectangular hollow sections (collectively referred to as RHS hereinafter) of commonly specified cross-sectional dimensions are produced using either the indirect-forming approach or the direct-forming approach. The indirect-forming approach, as the conventional approach of the two, consists of three steps: (i) roll-forming the coil material progressively into a circular hollow section; (ii) closing the section using electric resistance welding (ERW); and (iii) reshaping the circular section into the final square or rectangular shape. On the other hand, the direct-forming approach, as the new approach of the two, roll-forms the coil material directly into the final square or rectangular shape. RHS with similar cross-sectional dimensions but different production histories (i.e., different cold-forming approaches and post-production treatments) are expected to have significantly different material and residual stress properties. However, RHS design provisions in the existing North American steel design standards (AISC 360-16 and CSA S16-19) are in general developed based on research on indirect-formed RHS and currently do not differentiate RHS cold-formed by different approaches. Based on the research presented in Chapter 1 of this thesis, comparing to indirect-formed RHS, direct-formed RHS in general contain lower levels of residual stresses around cross sections, since the flat faces are not severely cold worked during production. This in turn affects member behaviours under compressive and flexural loadings. The test results presented in Chapters 2 and 4 show that direct-formed RHS have superior stub column and beam behaviours, comparing to their indirect-formed counterparts. In particular, the stub column and beam testing programs, covering a wide range of cross-section dimensions and two strength grades (nominal yield stresses of 350 and 690 MPa), show that the slenderness limits in the existing North American steel design standards are excessively conservative for direct-formed RHS, resulting in unnecessary penalty and member strength underestimation. As a result, the existing design formulae are not suitable for direct-formed RHS. In response to this, subsequent finite element (FE) parametric investigations are performed and presented in Chapters 3 and 5. Modified stub column and beam design recommendations for direct-formed regular- and high-strength RHS are proposed. The effects of post-cold-forming hot-dip galvanizing on material properties, residual stresses, stub column behaviours and beam behaviours of direct-formed regular- and high-strength RHS are also studied in Chapters 1-5 of this thesis. Similar to the application of the heat treatment per ASTM A1085 Supplement S1 or the Class H finish per CSA G40.20/G40.21, post-cold-forming galvanizing improves the stub column (Chapter 2) and beam (Chapter 4) behaviours of direct-formed RHS via effective reduction of residual stresses (Chapter 1). Based on subsequent FE parametric investigations, modified stub column and beam design recommendations catering to galvanized direct-formed RHS are proposed in Chapters 3 and 5. / Graduate

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Over time the level of inoculant will decrease due to fading and this needs to be compensated bymore additions of inoculant. When casting CGI400 at Scania a one-step method is used, and the inoculant additions are based on the last ladle from the previous oven. Longer stops in production will result in the previous oven not being representable and more inoculant should be added. A method to establish the inoculation level of the base iron in the oven would make it easier to control the process. This study was about inoculation measurements with the help of thermo- analysis of the melt in the oven to get a better understanding how it fluctuates between ovens and changes over time. The study is also about how to implement this tool into production in a foundry. With the help of thermo- analytic measurements, the inoculation level of the melt was established, and the method was also used to see how the level of inoculant changed over. To establish the inoculation additions needed, the saturation point of inoculant was investigated. The results from the study shows that the starting level of inoculant is too low in the melt it also shows that the inoculation level fluctuates over time. The conclusions that can be drawn from this study is that thermos analysis can be used in production to establish the inoculation level, but moremeasurements needs to be conducted to determine its accuracy. / Över tid så minskar ympnivån i en smälta på grund av fading och detta måste kompenseras med mertillsatser av ymp. Vid gjutning av CGI400 på Scania används en en-stegs metod där man baserar ymptillsatsen i skänken på vad ympnivån var i sista skänken från den tidigare ugnen. Vid längre produktionsstopp kommer inte ympnivån från ugnen innan vara representativ utan mer ymp måste tillsättas. En metod för att bestämma ympnivån av basjärnet i ugnen skulle göra det lättare att styra processen. Denna studie handlar om ympmätning med hjälp av termisk analys i bas smälta för att få en bättre förståelse för hur den fluktuerar mellan ugnar och ändras över tid. Studien handlar också om hur man ska kunna applicera denna mätmetod i produktionen på ett gjuteri. Med hjälp av termo analytiska mätningar skulle grundnivån av ymp i smältan bestämmas och även för att se hur nivån ändrades över tiden. För att bestämma tillsatsen av ymp som borde tillföras undersöktes mättnadspunkten av ymp och hur den kunde tillsättas i skänk. Resultaten från studien visar att grundnivån av ymp är för låg och resultaten visar också att nivån av ymp fluktuerar både upp och ner ökar tid vilket inte var vad man hade förväntat sig och även det finns flera faktorer som kan påverka nivån. Slutsatsen som kan dras är att termisk analys kan användas i produktion för att bestämma ympnivån, men mer mätningar behövs för att bestämmadess noggrannhet.

Im September 2015 fand das 8. Symposium „Experimentelle Untersuchungen von Baukonstruktionen“ an der TU Dresden statt. Der inhaltliche Bogen spannte sich vom DAfStb-Sachstandbericht zur Festlegung historischer Kennwerte von Betonen und Stählen über baudynamische Untersuchungen, neue Messmethoden bis zum Bauwerksmonitoring. Berichte von Projekten zur experimentellen Traglastbestimmung rundeten das vielfältige Programm ab.

Finite element analysis modeling is a powerful technology to predict the response of materials and structures under certain loaded situations including the applied force, the changing temperature and humanity, the alterative boundary condition, etc. In this paper, the mechanical properties of wood material were analyzed with an emphasis on bending behavior under lateral applied force with the finite element simulation in ABAQUS (Dassault Systèmes, 2020 version). Two methods were conducted in ABAQUS commercial software and the modulus of elastic (MOE) attained from the computational results were compared with the data obtained from the experimental records. The simulation model with grain patterns into consideration showed more accurate behavior when comparing with the displacement from the 3rd point bending test during the elastic range. Machine learning method is widely applied to the image processing procedures like digital recognition. The paper developed a python script to process the wood image cross section with an environmental background and calculated the late wood proportion based on the unsupervised machine learning concept. Grab cut function and Gray Level Co-Occurrence Matrix (GLCM) image processing were defined to obtain the wood section and wood texture features separately. K-Means method was used to cluster the latewood and early wood material based on the mean value from the GLCM matrix then the script was able to calculate the ratio with a simple definition of the equation. The results of the latewood ratio from the python script were compared with the ratio from the dot grid method in this paper. Statistical models in SPSS version 27 (IBM, Chicago, IL) were taken for this paper to predict the relationship between several parameters quantitatively. Since the density, latewood ratio, and number of rings per inch are obviously correlated with each other, this paper proposed a ridge regression statistical model to study the relationship between MOE/modulus of rupture (MOR) with multiple independents. Ridge regression model is also known as Tikhonov Regularization method which aims to solve the collinearity problems that may lead to statistical bias with stepwise regression analysis.

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No description available.

Demands for energy have been increasing in the whole world. According to higher consumption, the price of energy rises yearly too. This evokes usage of insulating products in a wider range. By adding insulation, we lower the amount of energy needed to heat our homes, resulting in fewer associated greenhouse gas emissions and a lower monthly heating bill. Savings depend on insulation thicknesses and on conditions, in which the insulant is kept. Mineral insulation based on stone wool is also a member of building insulants that defends buildings and constructions against temperature changes of the ambient. However, even when we use modern technologies and building techniques to reduce high energy losses, we can never provide unimpeachable protection of stone wool from damage. During a construction process on a building site or at fast climate changes, it often happens that stone wool is exposed to rain precipitaions or other climate effets. This brings water to the insulating structure. Besides the loss of insulating qualities, the stone wool is left permanently wet. Even the fibres of stone wool are inorganic, they still can be attacked by degradation processes due to organic agents fixing fibres together. Analysis of damaged flat-roof constructions using stone wool and verification of material properties is a starting point of this licentiate thesis. The attached paper section can be divided into two parts: In-situ practice that notes troubles with insulating materials based on stone wool with inbuilt moisture on a building site Laboratory measurement that observe material properties of stone wool under varying conditions / QC 20101122

A detailed characterization of the Ini-xGaxAsyP1-j, quaternary material system lattice matched to GaAs, grown by gas source Molecular Beam Epitixy (MBE) has been performed. Photoluminescence, X-ray diffraction and Transmission Electron Microscopy (TEM) were used to study the lateral composition modulation (LCM) which was observed in this material system. Optimization of the growth process and the substrate orientation resulted in a significant reduction of the LCM. Additionally, a comprehensive analysis of the optical constants was performed which resulted in the first publication of wavelength and composition dependent index of refraction data for this material system. The combination of growth optimization and index of refraction data lead to the demonstration of efficient, low threshold operation of InGaAsP/GaAs based multiple quantum well lasers. In order to efficiently couple the above laser diodes to an external cavity to facilitate the generation of ultrashort pulses, antireflection facet coatings were required. As such, optical interference filters have been fabricated using a plasma enhanced chemical vapor deposition system, based on the SiOxNy material system. High quality antireflection facet coatings, suitable for application to the InGaAsP/GaAs diode lasers have been designed and fabricated, resulting in modal reflectivities of 1-2 x 10-4. Finally, an ultrashort-pulse external-cavity diode laser system was designed and manufactured which allowed the laser diode to be wavelength tuned and emit mode-locked ultrashort optical pulses. Pulses with sub 2 ps duration and greater than 1 mW average output power have been achieved. A study of the novel application of an asymmetric quantum well structure to the generation of ultrashort optical pulses has been proposed and initiated. / Thesis / Doctor of Philosophy (PhD)