This thesis focuses on designing thermoplastic composites with high mechanical properties and a low processing temperature. Thermoplastic composites, which are used in this work, are composed of thermoplastic polyurethane (TPU) matrices and plain woven E-glass fabrics (GFs). TPUs were synthesised with large quantities of hard segments (HS), including 70% and 90%wt HS. The GF-TPU composites manufactured in this study have a melting point of around 175oC. As such, 180oC represents the processing temperature, which was used to produce GF-TPU composites. The influences of HS content and annealing treatment at 80oC on the thermal, dynamic mechanical and mechanical properties of TPU samples and GF-TPU composites with 25% fibre volume fraction (Vf) have been investigated. The highest crystallinity, storage modulus, Tg, yield strength, tensile strength and tensile modulus of all the TPU samples are seen in the TPU/90 samples annealed for 4 days. The TPU/90 samples display higher tensile properties than the TPU/70 and polypropylene (PP) samples, while the PP samples show the greatest elongation at break point. Furthermore, the tensile properties of the TPU/70 and TPU/90 samples are much higher than those of commercial TPUs. As such, annealed GF-TPU/90 composites with 25% Vf present the greatest dynamic mechanical, flexural, and tensile properties. GF-TPU/90 composites with 25% Vf show higher flexural strength than GF-PP composites or GF-polyamide 6 (PA6) composites with the same Vf. The effects of fibre surface treatments on the mechanical properties of GF and GF-TPU/70 composites with 25% Vf have also been studied in this investigation. GF treated with burn-off treatment is found to exhibit the lowest tensile properties. The interfacial adhesion between GF treated by NaOH for 0.5hrs and a TPU/70 matrix is greater than between GF treated by acetone for 5hrs and a TPU/70 matrix. Silanised GF presents greater tensile properties than desized GF. Thus, enhanced interfacial adhesion and tensile, flexural, ILSS and GIC properties are observed in the silanised GF-TPU/70 composites than in the desized GF-TPU/70 composites. GF-TPU/70 composites based on GFs treated by NaOH for 0.5hrs then sized with 0.15%wt. aminosilane display the greatest interfacial adhesion, flexural properties, ILSS and GIC, damage tolerance and impact-damage resistance. Conversely, the lowest interfacial adhesion, GIC, damage tolerance and impact-damage resistance are seen in the GF-PP composites based on 25% Vf as-received GF. There is a significant increase in the tensile and flexural properties of GF-TPU/90 composites with increasing the Vf from 25% to 50%. Moreover, the flexural strength of GF-TPU/90 composites with 50% Vf is not only higher than that of GF-EP composites or GF-vinyl ester composites with normalised 50% Vf, but is also much higher than that of GF-PP composites with 50% Vf. Despite this result, GF-TPU/90 composites with 50% Vf show the lowest fracture toughness, impact-damage resistance and damage tolerance, which are improved by adding 25% and 50%wt. of TPU/70 to the TPU/90 matrix. GF-TPU/90 composites based on a modified matrix have higher GIC, GIIC, impact-damage resistance and damage tolerance than GF-TPU/90 composites based on an unmodified matrix. The GIC, GIIC, impact-damage resistance and damage tolerance of GF-TPU/90 composites based on a modified matrix increase with increasing the percentage of TPU/70. Hence, the highest GIC, GIIC, impact-damage resistance and damage tolerance are seen in the GF-TPU/90 composites based on a modified matrix with 50%wt. of TPU/70.

Det finns stora förluster i sågverk som inte framkommer av deras traditionella driftsuppföljnings¬processer. Strategiskt viktigt för organisationen är frågan vad företaget behöver göra för att bli effektivt. I detta arbete diskuteras mätmetoder av effektivitet med avseende på underhåll och hur effektiviteten kan mätas med hjälp av att beräkna den totala utrustningseffektiviteten (OEE). Arbetet beskriver också olika underhållsstrategier och processen med att införa en sådan policy på sågverk. Under en period av sex dagar beräknas OEE på fem sågverk. Resultatet var att OEE värdet i snitt var runt 50 procent, som är ganska lågt. Genom att applicera en kostnadseffektiv underhållspolicy kan företaget öka sitt OEE värde och få en mer effektiv process. Detta kan göras genom att en policyn minskar de övergripande kostnaderna relaterade till de sex stora förlusterna. Diskussion förs också kring avvikelserna/stoppen och hur orsakerna till dessa kan härledas genom analyser med t.ex. Ishikawadiagram. Arbetet lyfter fram att ett systematiskt förbättringsarbete skulle ge nästan ett fördubblat kapacitetsutnyttjande för sågverken utan några större investeringar. I arbetet beskrivs hur sågverken kan bli framgångsrikare med detta genom att välja en kostnadseffektiv underhållspolicy. / There are several big losses in sawmills that are not addressed by the traditional operation feedback systems. It is strategic significant for organizations to address the question what need to be done in order to bee more effective. This work discusses methods of measurement the effectiveness with respect to maintenance and how the effectiveness can be measured by assessing the Overall Equipment Effectiveness (OEE). The work also emphasizes on maintenance strategies and the process of implementing such a policy in sawing mills. During a period of six days assessments of OEE were made in five different sawmills. The results were that OEE in general were about 50 percent, which is considered low. By implementing a cost-effective maintenance policy, it will lead to increase the value of OEE for the process. Using a policy that will decrease the overall costs related to the six big looses could do these. Discussions the production stoppages and how these can be analyzed by using different tools, such as Ishikawa diagram are addressed. The work highlights that a systematic improvement work would increase appreciably the capacity utilized without any large investments. This study also describes how sawmills can be successful when increasing their effectiveness by selecting a cost-effective maintenance policy for their process.

<p>Det finns stora förluster i sågverk som inte framkommer av deras traditionella driftsuppföljnings¬processer. Strategiskt viktigt för organisationen är frågan vad företaget behöver göra för att bli effektivt. I detta arbete diskuteras mätmetoder av effektivitet med avseende på underhåll och hur effektiviteten kan mätas med hjälp av att beräkna den totala utrustningseffektiviteten (OEE). Arbetet beskriver också olika underhållsstrategier och processen med att införa en sådan policy på sågverk. Under en period av sex dagar beräknas OEE på fem sågverk. Resultatet var att OEE värdet i snitt var runt 50 procent, som är ganska lågt. Genom att applicera en kostnadseffektiv underhållspolicy kan företaget öka sitt OEE värde och få en mer effektiv process. Detta kan göras genom att en policyn minskar de övergripande kostnaderna relaterade till de sex stora förlusterna. Diskussion förs också kring avvikelserna/stoppen och hur orsakerna till dessa kan härledas genom analyser med t.ex. Ishikawadiagram. Arbetet lyfter fram att ett systematiskt förbättringsarbete skulle ge nästan ett fördubblat kapacitetsutnyttjande för sågverken utan några större investeringar. I arbetet beskrivs hur sågverken kan bli framgångsrikare med detta genom att välja en kostnadseffektiv underhållspolicy.</p> / <p>There are several big losses in sawmills that are not addressed by the traditional operation feedback systems. It is strategic significant for organizations to address the question what need to be done in order to bee more effective. This work discusses methods of measurement the effectiveness with respect to maintenance and how the effectiveness can be measured by assessing the Overall Equipment Effectiveness (OEE). The work also emphasizes on maintenance strategies and the process of implementing such a policy in sawing mills. During a period of six days assessments of OEE were made in five different sawmills. The results were that OEE in general were about 50 percent, which is considered low. By implementing a cost-effective maintenance policy, it will lead to increase the value of OEE for the process. Using a policy that will decrease the overall costs related to the six big looses could do these. Discussions the production stoppages and how these can be analyzed by using different tools, such as Ishikawa diagram are addressed. The work highlights that a systematic improvement work would increase appreciably the capacity utilized without any large investments. This study also describes how sawmills can be successful when increasing their effectiveness by selecting a cost-effective maintenance policy for their process.</p>

This thesis deals with a construction of modified RepRap 3D printer Rebel II which operates with Fused Deposition Modeling technology and selection of suitable criterion for printing. It mainly focuses on the temperature of the material being printed and speed of printing for three selected materials. Materials were selected based on availability in the market and their application. An experiment, focusing on surface changes of products as well as on the look of a fibre after passing through a nozzle, was performed.

No description available.

Den snabbt växande utvecklingen av AI-baserade applikationer och den stora mängden data dessa applikationer behandlar ställer ökade krav på prestanda och optimering av datorsystemen. För att tillfredsställa de växande datorbehoven används hårdvaruacceleratorer som förbättrar databehandlingshastigheten genom att avlasta den befintliga utrustningen genom att hjälpa till med uppgifter och komplexa beräkningar. De befintliga lösningarna som används i dagsläget är kostsamma och MT-FoU på Umeå Universitetssjukhus efterfrågar därför en alternativ lösning i form av att kombinera mindre integrerande acceleratorer på ett större PCIe-kort. I detta examensarbete designas och implementeras en AI-accelerator bestående av fyra Google Coral Dual Edge TPU M.2 på ett 16x PCIe-kort. Arbetet genomfördes på MT-FoU och målet med examensarbetet var att undersöka om den tilltänkta konstruktionen kan förbättra prestandan hos AI-baserade system och fungera som ett billigare alternativ i verksamheten. Schemaritning och PCB-design utfördes i KiCad och information om gränssnitt och komponenter hämtades främst från tillverkares hemsidor och datablad. Kretsen består i huvudsak av fyra stycken M.2 E key kontaktdon, en 16port/16lane packetswitch och en 16x PCIe-anslutning. Switchen delar upp banorna från PCIe porten så att Edge TPU’erna kan anslutas parallellt i M.2 kontakterna. Edge TPU’erna använder pipelineparallellism för att fördela arbetsuppgifter på varje TPU så att större, mer komplexa program kan exekveras. Vid monteringen av kretskortet uppstod problem med fastlödningen av vissa komponenter. För att undvika att dessa problem uppstår och möjliggöra avlägsnandet av dessa felkällor bör montering istället beställas av fabrik där lödrobot finns tillgängligt. På grund av att tiden för kursen tog slut hann en sådan beställning inte göras och evaluering av den framtagna designen var därför inte möjlig att genomföra. Den design som togs fram var dock betydligt billigare än de existerande lösningarna och med pipelineparallellism förväntas designen kunna utföra komplexa beräkningar och därmed förbättra prestandan i befintliga system. / The rapidly growing development of AI-based applications and the large amount of data these applications process place increased demands on the performance and optimization of conventional computer systems. To satisfy these growing computing requirements, hardware accelerators are used to improve the data processing speed by offloading the existing equipment by executing models and complex calculations. The existing solutions currently used are costly and MT-R&amp;D at Umeå University Hospital is therefore requesting an alternative solution by combining smaller integrating accelerators on a larger PCIe card. In this thesis, an AI accelerator using four Google Coral Dual Edge TPU M.2 on a 16x PCIe card is designed and implemented. The work was carried out at MT-R&amp;D and the goal of the thesis was to investigate whether the intended design can improve the performance of AI-based systems and serve as a cheaper alternative in the institution. Schematic and PCB were designed in KiCad and information on interfaces and components was obtained from manufacturers' websites and data sheets. The circuit’s main components are four M.2 E key connectors, a 16port/16lane packet switch and a 16x PCIe connection. The switch divides the lanes from the PCIe port so that the Edge TPUs can be connected in parallel in the M.2 connectors. The Edge TPUs use pipeline parallelism to distribute models across each TPU so that larger, more complex programs can be executed. When assembling the circuit board, problems arose with the soldering of certain components. In order to avoid these sources of error, assembly should instead be ordered from a factory where a soldering robot is available. Due to the fact that the time for the course ran out, such an order could not be placed and evaluation of the design was therefore not possible to carry out. However, the design that was produced was significantly cheaper than the existing solutions and by using pipeline parallelism, the design is expected to be able to perform complex calculations and thus improve the performance of existing systems.

Children diagnosed with Attention Deficit Hyperactive Disorder (ADHD) are often secluded from society, as the condition is perceived to be a defect. These children constantly fidget, move, lose track of time, and forget to complete tasks, leading them to struggle within existing social environments. Additionally, in Qatar there is a need to educate society about ADHD. This research explores wearable solutions that alter behaviors through physical interactions and sensory engagements. In response to the challenges faced by ADHD, Qatari traditional attire has been customized to support children with time management, and communication between child, parent, and society. Additionally, these wearables challenge Qatari perspectives surrounding existing health conditions in Qatar. Design outcomes consists of clothing elements, driven and shaped by the experiences of ADHD children, their physical behavior, their senses like touch, smell and sight. It addresses the daily conduct of the ADHD child, and the relationship of the child and parent. By challenging existing norms and analyzing the Qatari traditional clothing (the Thobe, the Abaya and the Prayer Bead), design outcomes have been realized by experimenting and playing with materials, prototyping and 3D printing on fabric. Existing functions of zippers, pockets, beads, cuffs and technical construction of the outfit have been redesigned and reconstructed.

The task performed in this assignment is to improve the reliability of Norden Machinery ABs product family. This is to be done by examining and replacing the belt used to stop the spreading of tubes from ingoing shipping crate to the infeed of the machine. The way that this was approached was by testing different candidates on a spectrum of their rigidity to find if a flexible or more rigid belt would perform better than the current context of the system. The testing was conducted for a period of 4 weeks and results were gathered by examining damages to the belts by the use of microscope. After the damage had been analyzed the conclusion was drawn that flexible alternatives seems to perform the task better than their rigid counterparts however more work is needed in the fields regarding the fastening and operation of the machine to use the best suited candidates derived from this test, the monolithic belt FMT-02TXCT-U1.

Nowadays, polymer-metal hybrids are covering a broad range of advanced applications, especially in the automotive or aerospace industries where high performance and lightweight components are highly demanded. Hybrid parts may offer additional functionality regarding strength, durability, impact and wear resistance without sacrificing size or weight of the full component. However, there are still challenges regarding improving the adhesion between dissimilar materials such as metals to polymers and its composites. There is a lack of research about the influence of a post heat treatment on adhesion and durability in polymer-metal hybrids manufactured through an overmolding processing chain. There is also a need for using adhesive promoters that may offer simultaneous corrosion protection to metallic substrates in order to extend the lifecycle of the part when subjected to diverse harsh environments. In this work, two organic coatings used as adhesive promoters on steel substrates were investigated: the first one is a polyester-based powder-coat adhesive developed in the Leibniz-Institute in Dresden. The second one is a high performance anti-corrosive electrophoretic paint that has never been reported in the literature as an intermediate adhesive layer in a thermoplastic-polyurethane (TPU) overmolding processing chain. A TPU was overmolded on both pre-coated steel substrates, and the adhesion of the polymer to the metal substrate was investigated after a heat treatment (annealing), and a subsequent hygrothermal aging at different temperature-humidity conditions. The influence of the annealing process on the adhesion and durability of the multilayered specimen was investigated in depth; similarly, failure modes and lifetimes were evaluated after the hygrothermal aging. Lifetime predictions calculated from kinetic parameters for solid decomposition -obtained from thermogravimetric analysis- were validated experimentally with polyurethane-steel hybrids commonly used as district heat pipes. Adhesion of TPU on the steel substrate using both organic coatings as adhesive promoters was successful due to the contribution of new physical-chemical and mechanical interactions at the polymer-coating interface, especially after annealing at 100 °C for 20 h. Additionally, heat treated hybrids exhibited a much better performance because of the apparent increased in the anchoring density at the polymer-metal interfaces. It is conclusive that progressive failure of the multilayered specimen is strongly dependent on water diffusion rather than thermolysis of any of the components, as it was detected by FTIR, and observed in the micrographs on the artificially-aged hybrid surfaces. Finally, accelerated aging was used to correlate lifetime predictions throughout the analysis of the kinetics of degradation using TGA experiments and mechanical tests. The calculated values of the activation energy evidence that durability of the polyurethane-based polymers is affected by temperature and humidity at the conditions described in this work. Lifecycle is directly related to kinetic parameters, and especially to the activation energy, EA. This kinetic parameter for pre-aged specimens, and particularly for those subjected to higher temperature conditions, were lower when compared to the fresh polymer; as it was demonstrated that TGA analysis is a primary tool to predict lifetime for thermoplastic and thermosetting polyurethanes.

Covid-19 pandemin är den mest omfattande pandemin i modern tid. Länder världen över har infört olika typer av krav och rekommendationer för att hämma smittspridningen, däribland rekommendationer om att bära munskydd. Tidigare studier har utvecklat modeller och system för att avgöra huruvida personer bär munskydd eller ej. Syftet med denna studie är att bevisa att det är tekniskt genomförbart att utveckla och implementera en IT-artefakt på en Google Coral Dev Board som i realtid inte bara kan avgöra om en person bär munskydd eller ej, utan även kan klassificera om ett munskydd bärs korrekt samt ge återkoppling om eventuell felanvändning. Ett sådant system skulle kunna användas för att uppmuntra och påminna om korrekt användning av munskydd. Det utvecklade systemet bygger på en två-stegs-arkitektur bestående av två stycken Convolutional Neural Networks (CNN), en förtränad ansiktsdetekteringsmodell samt en egenutvecklad klassificeringsmodell som bygger på en MobileNetV3-arkitektur. Klassificeringsmodellen tränades med hjälp av ett dataset bestående av 184 572 bilder och kategoriserar ansikten i fyra olika kategorier: munskydd används korrekt, munskydd täcker ej näsa, munskydd placerat på haka och munskydd används ej. Vid 5-delad korsvalidering uppnådde klassificeringsmodellen en genomsnittlig accuracy på &gt;0.9994. Resultaten för studien var goda och bevisar den tekniska genomförbarheten. Den utvecklade prototypen kunde med hög tillförlitlighet detektera och korrekt klassificera ansikten i en videoström. Dock kommer studien fram till att denna typ av två-stegs-arkitektur är mindre lämplig i situationer då ett större antal ansikten är synliga i bild samtidigt då tiden som krävs för att behandla en bild ökar när antalet ansikten blir fler, vilket innebär att systemet ej kommer upplevas som responsivt.