Luleå University of Technology Publications
Not a member yet
39356 research outputs found
Sort by
Flödesmekanisk modellering av konvektion mellan solid till fluid i plåthärdnings process
No full textThe goal of this master thesis is to minimize waste in the steel industry by gaining understandingof the steel quenching process through computational simulations. Throughthe combination of fluid dynamics simulations and FEM simulations the material propertiesof the end product can be predicted before production. This master thesis focuses on the cooling process of steel quenching on the exterior ofthe steel work piece. The study dwells into how controlling the parameters for jet sprayquenching like the volume flow, jet nozzle diameter and radius of the wetting zoneaffects the cooling on the interior of the steel. The cooling process can be analyzedand understood through results obtained by computational fluid dynamics simulations.These results are then post processed as data points in Matlab to determine the linkbetween aforementioned parameters and the cooling. The cooling on the exterior ofthe steel work piece is then applied to a FEM model to simulate the interior cooling.The result from the FEM simulation is then in retrospective used to find the a properdesign setup of the jet spray cooling for minimal waste. The results of this thesis shows promise, while not perfect it can still be used for industrialapplication taken that the person utilizing the results is willing to stay on the safeside and oversize any construction based on this thesis. The fluid dynamics simulationscorrelate well with already existing research in the field of steel plate quenching
Young Workers Want To Be in the Office : An Investigation Based on Swedish Survey Data
No full textThe purpose of the chapter is to find out if the preference for working from home is different among different age cohorts, with a special interest in young workers attitudes. A survey involving 1,769 Swedish workers, among whom 1,000 were classified as office workers. In contrast to prevailing assumptions regarding the younger generation’s inclination towards remote work, our survey data from the Swedish labour market uncovers a surprising trend: it shows that young individuals exhibit a stronger preference for working in a physical office environment compared to their more senior counterparts. Overall, the results presented in the chapter underscore the rapid changes in working conditions, the need for updated knowledge, and the relevance of continuous labour market research. It provides valuable insights for both the public and policymakers, highlighting the importance of understanding diverse preferences and adapting to evolving work environments. The results underscore the necessity for customised employer policies that consider the diverse preferences within the workforce. ISBN for host publication: 978-1-032-48904-9, 978-1-032-48902-5, 978-1-003-39133-3;Full text license: CC BY-NC-ND</p
Wiggle Room in Practice: Project Managers Navigating Paradoxes Through Collaboration
No full textProject managers in interorganizational projects face paradoxes arising from competing demands from the parent and project organizations. Through a longitudinal research approach of eight infrastructure operation and maintenance projects across two case studies, we explore how project managers navigate these paradoxes through formal and informal collaboration. The study finds that public project managers practice contractual wiggle room to informally negotiate with private project partners, and that a formalization of collaboration risks disrupting well-functioning informal practices. These findings highlight the importance of recognizing the role of informal collaboration and ensuring procurement strategies remain adaptable to project-level conditions.Full text license: CC BY</p
Simulation of tropical cyclone microwave images based on ECMWF forecast data
No full textAssimilation of passive microwave imaging under all-sky conditions has in recent years proven beneficial to improving the forecasting capabilities of the European Centre for Medium-Range Weather Forecasts (ECMWF) numerical weather prediction model. Consideration may then be taken as to whether the ECMWF could benefit from providing simulated microwave imagery. A prevalent use case for such data would be tropical cyclones but for such consideration to be taken assessment of the current state of microwave simulated imagery is needed. The following thesis aims to provide an initial analysis of the validity and usefulness of simulated microwave imagery within this context by looking at the tropical cyclones Freddy, Beryl and Kong-rey. This work relies mainly on the 36.5 GHz and 89 GHz channels of the imaging radiometer AMSR2 where the primary signatures are scattering and emission from frozen- and liquid hydrometeors respectively. Simulated imagery was produced through the implementation of the radiative transfer model RTTOV via the independent simulation tool Radiance Simulator with input of atmospheric model fields from the ECMWF's forecasting system. Forecast verification via comparison to actual observed AMSR2 imagery found that the simulation, whilst recreating general large scale anatomy, lacked in small scale accuracy over convective and precipitating features. The main signifiers of the simulated imagery across cyclone features were: the production of too little scattering and emission, smeared out anatomy and blurred edges. The simulation discrepancies were emphasised as either originating from inaccurate parameter production in the forecast model or the radiative transfer models treatment of input fields with regards to scattering and emission. These findings conclude that, whilst the results provide a good tool for identifying current shortcomings in simulated microwave imagery, further work is needed to identify the sources of these errors
John Henry live at STHLM CBR
No full textJohn Henry performs at Stockholm CBR, 20250712. Validerad;2025;Nivå 0;2025-12-16 (U3) </p
Tälj : Grafisk design för att tillgängliggöra hantverk i vardagen
No full textTälj är resultatet av ett arbete som undersöker hur grafisk design kan sänka trösklarna till hantverk i hemmet. I ett samhälle där många vuxna inte längre skapar med händerna riskerar barn att växa upp utan att se kreativitet som något vardagligt. När praktiskt skapande försvinner ur hemmet blir det lätt något som uppfattas som svårt, främmande eller otillgängligt. Med utgångspunkt i intervjuer, litteraturstudier och även en normkritisk designprocess har jag tagit fram ett täljkit riktat till vuxna men med barnen i åtanke. Förpackningen är utformad för att kunna stå framme och väcka nyfikenhet. Den rymmer en träbit, ett sandpapper, ett plåster och ett instruktionsblad i form av en altarbroschyr. Instruktionen innehåller steg för att tälja en smörkniv, tips på täljgrepp och inspiration för den som vill fortsätta. Genom att kombinera visuella strategier med ett tillgängligt uttryck vill projektet utmana bilden av vem hantverk är till för och visa att det går att börja precis där man är.Tälj is the result of a design exploration into how graphic design can lower the threshold for engaging with woodcraft at home. In a society where many adults no longer work with their hands, children risk growing up without seeing creativity as a natural part of everyday life. When craft is absent from the home, it may seem unfamiliar or inaccessible. This project targets parents of school-aged children, especially those who do not consider themselves “crafty”. Through interviews, literature studies and a norm-critical design process, I developed a whittling kit that includes a wooden blank, sandpaper, a band-aid and a fold-out instruction sheet. The packaging is designed to double as storage and to be left out in the home, functioning as a visual and practical object that sparks curiosity. The instruction is simple, visual and printed in the format of a fold-out leaflet. It includes steps for carving a butter knife, tips on knife grips, and inspiration for future projects. The result shows that design can be used to challenge ideas of who craft is for, and to make it easier for more people to get started. By combining accessible visuals with thoughtful packaging, Tälj aims to encourage creativity in everyday life - right where you are, with what you have
Vision-based planting position selection system for an unmanned reforestation machine
No full textResearch on automated seedling planting systems in forestry is a crucial aspect of forestry automation. This paper introduces the development of a vision-based automated seedling planting position selection system, integrated with hardware and software components on an unmanned forest machine platform. Developed around object detection as the core, this research presents a comprehensive system consisting of two main functionalities: (i) A vision system that performs obstacle detection and localization, providing estimated obstacle types, sizes, and positions to the plant planner function. (ii) A plant planner function utilizes this information to plan the plantable areas and selects suitable planting locations. The integrated system has been tested in the field and we found it to effectively determine suitable planting locations on the ground of a clear-cut. The implementation of this system lays the foundation for subsequent automated planting operations. Furthermore, the automation of forest seedling planting reduces the need for manual labor and enhances planting precision, contributing to improved forest health and ecological balance. Looking ahead, this research offers insights into the future development of unmanned forestry operations, making strides in automating forest management, achieving cost-effectiveness, and facilitating ecological restoration. Validerad;2025;Nivå 2;2025-03-14 (u4);Full text: CC BY License;This article has previously appeared as a manuscript in a thesis.</p
Combustion as a remediation method : A study of the rescue service's possibilities for combustion of diesel in nature
No full textEn viktig uppgift för svensk räddningstjänst är skadebegränsning vid olyckor som involverar utsläpp av diesel. Med dagens metoder har räddningstjänsten bara kapacitet att hantera utsläpp som lagt sig på ytan. I den här rapporten undersöker vi en ovanlig metod som tidigare bara använts ett fåtal gånger, och kollar på dess effektivitet att rena jorden från diesel. Metoden utgår från naturliga fenomen i jord som kapilläreffekt och diesels brännbara egenskaper för att suga upp diesel ur jorden och förbränna det på ytan. De experimentella testerna undersöker metodens beroende av djup, fuktinnehåll, jordart och ökad kapilläreffekt med vekar. Resultatet visar att metoden har en högsta saneringsförmåga på 88% för lera-silt och en lägsta saneringsförmåga på 42% för morän. Jämfört med andra metoder som används idag visar sig avbränning av diesel vara minst lika effektiv för sanering av förorening på ytan av jorden, samtidigt som den också har möjlighet att hantera dieseln under jordytan. Mångsidigheten av denna metod gör att den vid rätt förutsättningar kan vara mer effektiv och mer hjälpsam och kan därför anses vara en förespråkad saneringsmetod för räddningstjänsten i framtiden.One important task for Swedish rescue services is damage control in case of accidents involving diesel products. With today’s methods rescue services only have the capacity to deal with contaminations on the surface. In this study we explore an uncommon tactic only used a couple of times before to explore its effectiveness and ability to cleanse soil from diesel. The method uses natural phenomena in soil like capillary action and the flammable nature of diesel to absorb diesel and combust it at the surface level. The experiments test the method’s dependency on depth, moisture content, type of soil and enhanced capillary action (wicks). The results show that the method had a peak remediation effectiveness of 88% for clay-silt and lowest remediation effectiveness of 42% for till. Compared to other methods used today the combustion of diesel has been shown by this study to be as effective in remediating the surface contaminants as well as being able to work subsurface. The versatility of the method means that in the right circumstances the method can be more effective and useful and could therefore be considered as a remediation method for rescue services going forward
Factors Influencing Nurses' Decisions to Stay or Leave the Profession : A Literature Review
No full textIntroduktion: Bristen på sjuksköterskor är ett globalt problem som påverkar både vårdkvaliteten och patientsäkerheten. I Sverige, som i internationella jämförelser ändå har hög andel sjuksköterskor, talas det ändå om kris. Organisatoriska och arbetsmiljömässiga faktorer bidrar till hög personalomsättning. Syfte: Att beskriva sjuksköterskors erfarenheter av att arbeta inom vården och som har betydelse för om de väljer att sluta eller stanna kvar i yrket. Metod: En kvalitativ litteraturstudie med induktiv ansats. Datasökning genomfördes i två databaser och resulterade efter kvalitetsgranskning i nio artiklar som analyserades med kvalitativ innehållsanalys med manifest ansats. Resultat: Analysen resulterade i fem kategorier: Att det är viktigt hur arbetsplatsen är organiserad, Att känna plikt och ansvar för sin profession, Att känna kontroll och ha en helhetsbild, Att förebilder och kollegor har betydelse och Att professionens värde och erkännande har betydelse. Negativa faktorer inkluderade bristande stöd, hög arbetsbelastning och låg uppskattning. Positiva faktorer som stödjande kollegor och ledarskap bidrog till en vilja att stanna kvar i yrket. Slutsats: Sjuksköterskors upplevelser speglar en komplex arbetssituation där både organisatoriska och sociala faktorer påverkar deras vilja att lämna eller stanna kvar i yrket. Det kan vara frestande att tänka att högre lön är lösningen - men denna studie visar att det är flera faktorer som har betydelse. För att öka viljan hos sjuksköterskor att stanna - och att förlängningen locka fler till yrket - krävs förbättrad arbetsmiljö och investeringar i ledarskap, arbetsvillkor och stöttande strukturer.
Between pedagogy and duty : Challenges and opportunities in reporting concerns
No full textThis study explores preschool teachers' experiences of challenges and opportunities when handling reports of concern regarding children who might be at risk. The purpose is to contribute to the development of the profession by examining the following questions: What challenges arise in connection with reporting concerns? What opportunities do such reports create? How do preschool teachers perceive the routines for addressing concerns about a child’s well-being? The results, presented in themes of challenges, opportunities, routines, and professionalism, highlight the preschool teachers' crucial role as often being the first adults to identify signs of children at risk. The study reveals significant emotional and practical challenges, such as interpreting children's signals, communicating with guardians, and dealing with inadequate support systems. However, it also identifies opportunities, including the ability to provide safety, access to resources, and professional growth through collaboration with social services and other stakeholders. The findings are analyzed through the theoretical lens of Theory of Professionalism by Thomas Brante, with focus on the terms habitus, legitimacy, and distancing, which help explain preschool teachers’ decision-making and handling of these complex situations. The results emphasize the importance of structured routines, professional support, and enhanced collaboration to strengthen the preschool teachers' ability to safeguard children’s rights and well-being, in line with legal and ethical responsibilities. This study underscores the critical need for ongoing professional development and systemic improvements to support preschool teachers in fulfilling their vital role