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When dealing with customers, original equipment manufacturers (OEMs) classify vehicular usage by resorting to simplified, often colloquial, descriptions that allow for a rough understanding of the operating conditions and the user’s needs. In this way, the information retrieved from the customers is exploited to guide their choices in terms of vehicle design and configuration, based on the characteristics of the transport application, labeled using intuitive metrics. However, a common problem in this context is the absence of any formal connection to lower levels of representation that might effectively be used to assess vehicular energy performance in simulation, or for design optimization using mathematical algorithms. Indeed, both processes require more accurate modeling of the surroundings, including exhaustive information about the local road, weather, and traffic conditions. Therefore, starting with a detailed statistical description of the environment, this paper proposes a method for mathematical classification of transport missions and applications within the theoretical framework of the operating cycle (OC). The approach discussed in the paper combines a collection of statistical models structured hierarchically, called a stochastic operating cycle (sOC), with a bird’s-eye view description of the operating environment. The latter postulates the existence of different classes, which are representative of the usage and whose definition is based on simple metrics and thresholds expressed mathematically in terms of statistical measures. Algebraic expressions, called operating classes in the paper, are derived analytically for all the stochastic models presented. This establishes a connection between the two levels of representation, enabling to simulate longitudinal vehicle dynamics in virtual environments generated based on the characteristics of the intended application, using log data collected from vehicles and/or information provided

In the assessment of concrete dams in cold climate, it is common that the theoretical stability becomes insufficient for load cases that include ice loads. However, the magnitude and return period of these ice loads have a high degree of uncertainty. This study estimates the magnitude of ice loads on eight concrete dam monoliths using measurements of their displacement from 29 winters. In the displacement signals, events are identified and assumed to be caused solely by ice loads. The observed displacement during an event is interpreted as an ice load using a load-displacement relationship derived from FE simulations of each dam. These simulations show that ice loads of the magnitudes given in design guidelines and recorded in previous measurements would significantly affect the structural response of the studied dams. However, only small traces of ice loads can be found in the observed responses of the studied dams. The estimated ice loads are significantly lower than the ice loads recorded in traditional ice load measurements. These results indicate that the average magnitude of ice load on an entire monolith is significantly lower than the measured local pressures. This would imply that ice loads may be a smaller concern regarding dam safety than previously believed., QC 20220318

In this dataset, data from experimental testing of fibre-reinforced shotcrete is presented. The dataset contains five different fibres made of steel (Dramix 3D, Dramix 4D and Dramix5D), synthetic (BarChip R54) and basalt (MiniBar). Preparation of specimens and testing were performed by Vattenfall R&D in Älvkarleby, Sweden. This first version of the dataset contains the results for shotcrete specimens prepared through casting. The same shotcrete mix was used for all specimens, and three different dosages were used for each of the fibres except for Dramix 5D, for which only two dosages were tested. The dataset contains the shotcrete mix and standard output for the test of compressive strength according to EN 12390-3, residual flexural strength according to EN 14488-3 and energy absorption according to ASTM C1550. This dataset can be used to study how the structural toughness of fibre-reinforced shotcrete is affected by the dosage of fibre. Moreover, the data can be used to compare the structural performance of fibres of different materials. The data also provide a foundation to select a reasonable dosage of fibres to fulfil the structural requirements put on shotcrete in the design phase., QC 20230404

Världen står inför en enorm utmaning där utsläppen av växthusgaser måste minskas för att bromsa den ständigt ökande globala medeltemperaturen. Samtidigt har en lång urbaniseringstrend lett till att transportinfrastrukturen i många tätbefolkade städer måste byggas ut för att bibehålla ett fungerande transportnät. I många fall är tunnlar det mest fördelaktiga alternativet eftersom de inte stör den befintliga stadsbilden. För att minska klimatpåverkan från byggandet av nya tunnlar har Trafikverket initierat ett forskningsprojekt som ska undersöka potentialen för alternativa fibrer och detta drivs av avdelningen för Betongbyggnad på KTH., QC 20221227

QCR 20221025

QC 20221025

Hydropower is an essential source of renewable energy. To secure power production in cold climates, it is of vital importance to continuously collect information regarding ice build-up around the power plant. The amount of ice, and the quality of the same, can cause significant loss in power production. Ice loads on dam structures are complicated to model and predict without plenty of data points. Traditionally this is performed by foot and using drilling, which is not only a safety issue but usually delivers too few data points to obtain an accurate model of the ice load. With recent developments of airborne GPR equipment, hazardous areas can be investigated safely and efficiently. Furthermore, in comparison to traditional methods airborne GPR collects vast amounts of data points, thus helping create better and more stable models for ice-loads. This paper covers a study from around a hydropower plant in northern Sweden. The study discusses the pros and cons of using air borne GPR equipment for securing hydropower production in cold climate areas., QC 20230908

QC 20230825

Sedan 2021 pågår byggfasen i ett projekt med fokus på flödesanpassning och delförnyelse av utskovsdammen vid Vattenfalls anläggning Lilla Edet i Göta älv. Till den nya dammdelen kommer cirka 8000 m3 betong att användas under uppförandet. För att minska koldioxidavtrycket från den betong som ska användas och för att reducera risken för temperaturrelaterad sprickbildning har en klimatförbättrad betong med mindre cement utvecklats., QC 20230825

Background: The brain is susceptible to hypoxic-ischemic brain injury in conjuction with out-of-hospital cardiac arrest (OHCA). Cognitive impairments are documented in about half of all OHCA survivors, however with a pronounced heterogeneity in measurements and findings. More detailed studies and instruments that are sensitive to OHCA-related cognitive impairment, including predictive models to identify individuals at risk, are needed. It is also unclear how different neurocognitive outcome methods are related to each other, to the brain injury, and to associated factors.Aims: The overall aim of this thesis was to explore the extent of neurocognitive impairment following OHCA in the late recovery phase. Specific aims per papers included in this thesis were: I) To examine the psychometric properties of an observer-reported questionnaire modified for usage after cardiac arrest, the Informant Questionnaire on Cognitive Decline in the Elderly-Cardiac Arrest (IQCODE-CA). II) To explore associations between four neurocognitive outcome methods administered in the late recovery phase and early hypoxic-ischemic brain injury assessed by the biomarker serum neurofilament light (NFL), and to compare the agreement for the four outcome methods. III) To describe the rationale and, IV) report initial results of detailed assessment of neurocognitive impairment in OHCA survivors, compare the cognitive performance to a cohort of participants following acute myocardial infarction (MI), and investigate the relationship between cognitive performance and the associated factors of emotional problems, fatigue, insomnia, and cardiovascular risk factors.Methods: I & II) Post-hoc analyses of surviving participants of the international multicenter Target temperature management 33 °C versus 36 °C after out-of-hospital cardiac arrest trial (TTM-trial), its biobank, and its cognitive sub-study, with a follow-up at 6 months post-arrest. III & IV) Prospective inclusion of surviving participants of t

Concrete buttress dams could potentially be susceptible to high-frequency vibrations, especially in the cross-stream direction, due to their slender design. Previous studies have mainly focused on low-frequency vibrations in stream direction using a simplified foundation model with the massless method, which does not consider topographic amplifications. This paper therefore investigates the nonlinear behaviour of concrete buttress dams subjected to high-frequency excitations, considering cross-stream vibrations. For comparison, the effect of low-frequency excitations is also investigated. The influence of the irregular topography of the foundation surface on the amplification of seismic waves at the foundation surface and thus in the dam is considered by a rigorous method based on the domain-reduction method using the direct finite element method. The sensitivity of the calculated response of the dam to the free-field modelling approach is investigated by comparing the result with analyses using an analytical method based on one-dimensional wave propagation theory and a massless approach. Available deconvolution software is based on the one-dimensional shear wave propagation to transform the earthquake motion from the foundation surface to the corresponding input motion at depth. Here, a new deconvolution method for both shear and pressure wave propagation is developed based on an iterative time-domain procedure using a one-dimensional finite element column. The examples presented showed that topographic amplifications of high-frequency excitations have a significant impact on the response of this type of dam. Cross-stream vibrations reduced the safety of the dam due to the opening of the joints and the increasing stresses. The foundation modelling approach had a significant impact on the calculated response of the dam. The massless method produced unreliable results, especially for high-frequency excitations. The free-field modelling with the analytical method led, QC 20220502

QC 20230213

Steel fibre reinforcement in homogenous, intact, wet-mix shotcrete show an excellent durability against corrosion. The alkaline concrete environment gives good protection but the relatively thin shotcrete layers may crack due to shrinkage and other deformations. Durability requirements today often demands service-life of more than 100 years, which is not realistic with a maintained load-bearing capacity. Special measures must therefore be taken in the design of shotcrete rock support, such as addition of extra amount of fibres if the shotcrete is cracked or increased structural thickness, which is here demonstrated with examples. Due to the complex situation with requirements on service-life, climate impact and cost-efficiency, the design of future shotcrete supports will be optimized based on life cycle and life cycle cost analyses., Part of proceedings: ISBN 978-967-18427-0-6QCR 20201019

The Kafue Gorge dam along Kafue River in Zambia was commissioned in 1971. In 1988 one of the spillway gates was jammed due to concrete expansion. Measures were taken, but signs of expansion and cracking continued. After rehabilitation works on one of the spillway gates in 2011 five stop-logs were stuck in position due to concrete expansion. In 2012, ZESCO and SWECO performed an in-depth assessment of the spillway structure with crack mapping and core sampling. Extensive cracking on the upstream side of the spillway piers with crack widths of up to 30 mm was found under water. Concrete analysis verified ongoing ASR. Numerical simulations on the behavior of the dam (with major cracks and ASR-expansion) showed that there was a need for stabilizing measures. SWECO designed remedial measures to restore full integrity of the dam and resolve the problem with the jammed stop-logs that caused reduced discharge capacity. During 2019 post-tensioned tendons are installed to ensure a monolithic behavior of the structure and improve the stability. All major cracks will be sealed to reduce the contact area of concrete and water. Finally, the jammed stop-logs will be removed to restore the discharge capacity of the spillway., QC 20191022

Inom dammövervakning används begreppen larm och varning för meddelanden om upptäckten av en potentiell dammsäkerhetsrisk. Larm är kopplade till ett akut farligt beteende och en varning till ett oförväntat beteende. Dammövervakning är således ett klassificeringsproblem där varje nytt uppmätt beteende ska klassificeras som säkert eller osäkert, alternativt som förväntat eller oförväntat. Ett farligt beteende innebär att dammsäkerheten är hotad akut medan ett oförväntat värde uppstår när dammen inte beter sig enligt förväntan utifrån rådande yttre förhållanden. En sådan avvikelse betyder inte per automatik att något är fel eller att säkerheten är hotad men en oskadad damm bör bete sig enligt ett förväntat mönster och en avvikelse från det förväntade beteende kan indikera en initiering av en skada hos dammen.För att bestämma det förväntade mätvärdet behövs någon typ av prediktionsmodell som förutsäger dammens beteende utifrån de yttre förhållandena. I denna rapport delas prediktionsmodellerna upp i teoribaserade och databaserade modeller. De teoribaserade modellerna bygger på en fysikalisk koppling mellan yttre förhållanden så som vattennivå och temperaturer och dammens beteende. I de databaserade modellerna är denna koppling istället empirisk och utan fysikalisk koppling.Det finns flertalet olika typer av instrument och givare för dammövervakning. I denna rapport sammanfattas vanliga typer avsedda för dammätningar, inklusive dess mätnoggrannhet. Dessutom diskuteras användningen av olika givare baserat på om de lämpar sig som detektorer vid ett potentiellt dammbrott eller om givarna främst är att anse som stödinstrumentering vars syfte är att bidra mer information om dammens beteende eller yttre förhållanden.Varje modelltyp har unika egenskaper med för- och nackdelar. Det är därför viktigt att välja modelltyp utifrån behov och syfte. En teoribaserad modell, t.ex. FE-modell, ger möjligheten att tolka resultaten och hitta fysikaliska samband, men är sämre på att förutsäga, In the field of dam surveillance, alert and alarm values are used for error detection to notify about the discovery of a potential dam safety risk. Alarm values are used to notify that a dangerous behavior have been reached. Alert values (warnings) are used to notify that the measured data is out of the expected range. Dam surveillance can thereby be considered as a classification problem where every measured response should be classified as safe or unsafe, or alternatively as expected or unexpected. Dangerous behavior implies that the safety of the dam may be compromised (e.g. the coefficient of safety may be surpassed), while an unexpected value occurs when the dam no longer acts according to the predicted behavior based on current conditions. Such a discrepancy does not necessarily mean that the dam safety is compromised, but could indicate that the dam is damaged.In order to determine the expected behavior, some type of prediction model is required that can predict the dam behavior based on ambient conditions. In this report, the prediction models are defined as either theory-based or empirical. The theory-based models are based on physics with correlation between ambient conditions such as water level and temperatures and the response of the dam. In the empirical models, this coupling is purely empirical without any physical meaning.There are several types of sensors that can be used for dam surveillance. In this report, the instruments commonly used within the field of dam engineering and their expected accuracy are discussed. In addition, the use of different sensors based on their purpose in the surveillance program is discussed where sensors are denoted as detectors or support instruments. The detectors are considered as sensors suitable to be used to monitor a potential failure mode while the purpose of the support instruments is to provide additional information about the dam response or the ambient conditions.Every type of model has unique properties wit, QC 20190828

QC 20190618

Det är via vattenvägarna som vatten transporteras från reservoaren, förbi dammen och sedan vidare nedströms i en vattenkraftsanläggning. Vattenvägarna vid en vattenkraftsanläggning kan generellt sett delas upp i yttre och inre konstruktioner. De inre vattenvägarna omfattar ett flertal konstruktioner som intag, tilloppstunnel, tilloppstub, intagssump, spiral, sugrör, svallschakt, svallgalleri och utloppstunnel. Dessa konstruktioner är vanligtvis helt eller delvis vattenfyllda vilket medför att de i många fall är svåråtkomliga för inspektion. Det är sällan ekonomiskt försvarbart att torrlägga de inre vattenvägarna enbart för inspektion till följd av det avbrott i elproduktionen som då uppstår. Dock uppkommer emellanåt möjligheten att få inspektera de inre vattenvägarna i samband med driftstopp för reparation, inspektion eller utbyte av de elgenererande delarna. På uppdrag av Energiforsk har en genomgång av den rapportering som finns från genomförda inspektioner gjorts i ett försök att förbättra kunskapsläget gällande eventuella typskador och nedbrytningsförlopp i de inre vattenvägarna. Insamlingen av underlag har gjorts genom förfrågningar hos ägarrepresentanterna i styrgruppen för vattenkraftens betongprogram inom Energiforsk. Det erhållna underlaget omfattade både besiktningsrapporter och sammanställningar över observerade skador i de inre vattenvägarna för sammanlagt 53 olika vattenkraftverk. Utifrån analysen av det erhållna materialet i denna studie kunde det konstateras att erosion var den vanligast förekommande skadetypen då samtliga typer av inre vattenvägar beaktas. Dock blev självklart bilden en liten annan i det fall de olika typerna av vattenvägar studeras enskilt även om erosionsskador oftast återfinns högt upp i listan över observerade skador och brister. Tidigare forskning har dock visat att det ofta är en samverkan mellan olika nedbrytningsmekanismer som resulterar i en observerad skada. Av denna anledning är det därför svårt att isolera en enskild nedb, The water is transported by the waterways from the reservoir, past the dam and further downstream in a hydropower station. Generally, the waterways can be categorized to be either of channel-type or tunnel-type. The waterways of tunneltype include a number of different structures such as intakes, headrace tunnels, penstocks, intake sumps, spirals, draft tubes, surge shafts, surge galleries and tailrace tunnels. These structures are usually either fully or partially filled with water, which means that they in many cases are hard to inspect. Moreover, it is seldom financially justifiable to drain the tunnels solely to perform an inspection due to the loss of energy production that this measure entails. However, in connection to stoppage of the energy production to repair, inspect or replace some of the energy-producing parts, an opportunity to inspect the waterways of tunneltype is usually given. In this study, a review of documentation from inspections of waterways of tunneltypes has been performed on behalf of Energiforsk to improve the state of knowledge regarding common damage types and deterioration mechanisms in this type of waterways. The collection of data has been performed by inquiring data from representatives of the utility companies in the steering committee of the research program for concrete in hydropower at Energiforsk. The obtained material includes both reports from inspections as well as compilations of observed damage in the waterways for a total of 53 different hydropower stations in Sweden. From the analysis of the obtained material in this study, it could be concluded that erosion was the most common type of damage observed in waterways of tunneltype if all types of such structures are considered. However, the results become a bit different if the different types of structures are studied individually, even though erosion often is observed to be one of the most commonly observed damage types. Previous research has, however, shown that an observ, QC 20190305

QC 20191008

A laboratory method for investigation of cored samples of steel fibre reinforced sprayed concrete (shotcrete) is described. A pilot study on computed tomography (CT) has been conducted, with focus on how the technique can be used for non-destructive testing where the cores remain intact after scanning and evaluation. The CT method require advanced integrated equipment for X-ray scanning and image detection, together with a computerized visualization system that can reproduce a threedimensional virtual, transparent model of the studied object. The method is well suited to describe orientation and distribution of steel fibres within the concrete. Interfaces between rock-concrete and concrete-concrete, between layers of differentsequences ofspraying, can also be identified. The results from the CT investigations can be presented as qualitative data that in 3D shows locations of steel fibres, aggregates, etc., and also as quantitative data showing relative distributions of cement paste, aggregates, steel fibres and voids, which is here demonstrated by a selection of examples. The method is well suited for practical analysis of sprayed concrete in situ specimens and it is recommended that it is established as a standard method for special inspections and performance evaluation of rock support in tunnels and subspace structures., QC 20181008

Children and adolescents receiving services from two professional parties may obtain support with a coordinated individual plan (CIP). The Swedish law prescribes that CIP must incorporate service user participation. This study aims to explore children and parents’ experiences of participating in CIP-process to generate knowledge with practical implications of how children and parents may be involved in the CIP-process. A descriptive qualitative interview study with 13 service users was conducted during November 2014 to March 2016. Data were audio-recorded and transcribed, and further subjected to qualitative content analysis. Three main descriptive categories with six subcategories emerged. The category “Struggle for coordination” includes service users’ need for participation which are limited by professionals’ lack of consensus. The category “Alliance for coordination” points out the importance of relationship and personal support to accomplish functional coordination. The category “Structure for coordination” shows how the structure facilitate service user involvement on a high level. Service user involvement seemed limited by professionals’ actions, but could be facilitated by support of professionals working in the child’s daily life. Structured coordination seems to relieve the pressure on parents, as well as children, but CIP needs to be individually tailored to reach its full potential., Included in thesis in its submitted form.