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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Re-inventing Core Body Temperature Measurement

SHAHROOZ, MINA January 2017 (has links)
Humans are considered an integral part of future energy systems. In this context, constant awareness of human body status is critical for building responsive and intelligent environment that take energy efficiency and human comfort to the highest limits. Core body temperature is one of human body vital signs for body’s proper functioning and comfortability. Continuous non-invasive Core Body Temperature (CBT) measurements is important for patient monitoring and health status tracking in sports, sleep studying and other clinical and care procedures. Currently, there is a lack of precise and versatile methods to capture core body temperature under varying ambient conditions and through practical wearable solutions. Meanwhile, greenTEG AG, Zurich Switzerland, has developed a batch production method enabling the production of small, sensitive and very robust heat flux sensors. The main aim of this project was to develop a commercial product which for the first time measured core body temperature by placement inside a light, affordable wearable hold. This report presents a comprehensive review on heat transfer in human body and thermoregulation concepts in the first chapter followed by the state of the art methods. Then in chapter 2, according to the project design, full description and result discussions of the numerical model of human body developed by the author, was used as a prelude to the experimental tests. The model developed for this study was a Finite Difference model of different tissue layers combined with appropriate convection and radiation heat loss formulations. Tests were conducted through rigorous considerations of real body conditions including variable core body temperature and changing environmental conditions. Numerical tests were also validated by comparing with experimental results. Numerical results provided a precise preview of experimental models’ measurements and were used in the development of experimental setups. One of unique aspects of this study was the fact that the numerical model was used along with the sensor output to capture CBT and was considered a part of final product. In chapter 3, experimental tests on both skin phantom and human trials are discussed together with the sensor design and configuration. Results show that our CBT monitoring system is capable of measuring stable core body temperature under changing environmental conditions. It could also track circadian rhythm of core temperature during sleep, which for the first time, makes it possible for non-invasive miniaturized CBT tracking systems to measure accurate core temperature. These calculations are based on novel algorithms by greenTEG that could compensate for varying environmental conditions. / Människan betraktas som en integrerad del av framtidens energisystem. I detta sammanhang är ständig medvetenhet om människokroppen status avgörande för att bygga lyhörd och intelligent miljö som tar energieffektivitet och mänsklig komfort till de högsta gränser. Kroppstemperaturen är en av människokroppen vitala för kroppens funktion och comfort. Kontinuerliga icke-invasiv kroppstemperaturen (CBT) mätningar är viktigt för patientövervakning och spårning hälsotillstånd i idrott, sömn studera och andra kliniska och vårdförfaranden. För närvarande finns det en brist på exakta och mångsidiga metoder för att fånga kroppstemperaturen under varierande omgivningsförhållanden och genom praktiska bärbara lösningar. Samtidigt greenTEG AG, Zurich Schweiz, har utvecklat ett parti produktionsmetod möjliggör produktion av små, känsliga och mycket robusta värmeflödessensorer. Huvudsyftet med projektet var att utveckla en kommersiell produkt som för första gången mätt kroppstemperaturen genom placering i en ljus, prisvärd bärbar håll. Denna rapport presenterar en omfattande översyn på värmeöverföring i människokroppen och termoregulering begrepp i det första kapitlet, följt av toppmoderna metoder. Sedan i kapitel 2, i enlighet med projektets utformning, fullständig beskrivning och resultat diskussioner om den numeriska modellen av människokroppen som utvecklats av författaren, användes som ett förspel till de experimentella testerna. Modellen utvecklades för denna studie var en ändlig skillnad modell av olika vävnadsskikt i kombination med lämpliga konvektion och strålningsvärme förlust formuleringar. Tester genomfördes genom rigorösa överväganden verkliga förhållanden kroppen, inklusive rörliga kroppstemperaturen och växlande miljöförhållanden. Numeriska tester också valideras genom att jämföra med experimentella resultat. Numeriska resultat gav en exakt förhandsvisning av experimentella modeller "mätningar och användes i utvecklingen av experimentella uppställningar. En av unika aspekterna av denna studie var det faktum att den numeriska modellen användes tillsammans med sensorns utsignal för att fånga KBT och ansågs vara en del av slutprodukten. I kapitel 3, är experimentella tester på både hud fantom och mänskliga försök diskuteras tillsammans med sensordesign och konfiguration. Resultaten visar att vårt KBT övervakningssystem är i stånd att mäta en stabil kroppstemperaturen under föränderliga miljöförhållanden. Det kan också spåra dygnsrytm av kärntemperatur under sömnen, som för första gången gör det möjligt för icke-invasiva miniatyriserade KBT tracking system för att mäta exakt kärntemperatur. Dessa beräkningar är baserade på nya algoritmer från greenTEG som kan kompensera för varierande miljöförhållanden.
62

Produktutveckling av repinfästning till marina förankringar / Product development of rope attachment for marine mooring systems

Carlsson, Jonas January 2019 (has links)
Detta examensarbete kallat ”Produktutveckling av repinfästning för marina förankringar” är utfört i samarbete med Seaflex AB. Det är en produktutveckling av en redan existerande komponent i företagets produktutbud. Företaget som riktar sig mot marina förankringar med flexibilitet och hållbarhet letar efter ett mer effektivt sätt att förankra repen i den flytande applikationen utan att kompromissa produktens tillförlitlighet. I överenskommelse med handledare vid Seaflex AB bestämdes det att ta fram ett verktyg applicerbart vid den nuvarande rep-infästningen efter att flera olika koncept lagts fram. Ritningar på ett verktygskoncept med hjälp av 3D CAD som skulle vara lätt att flytta mellan de olika rep-infästningarna. Verktyget var byggt på två klaffar som kan rotera på axlar stött av en ramkloss på vardera sida. För att kunna dimensionera klaffarna i verktyget utfördes i en dragprovsmaskin ett tryckprov över repet för att se hur repet uppförde sig när det blev utsatt av en viss last.   En prototyp på verktyget togs fram och tillverkades som en funktionsprotyp anpassad för en dragprovsmaskin för att verifiera att konceptet fungerar. Funktionsprototypen kunde på grund av material inte tåla lika stora belastningar som konceptets ordinarie konstruktion och fick därför köras med andra dimensioner. Dragprovet på funktionsprototypen kördes i flera test med olika dimensioner och resultaten indikerade att funktionen och konceptet fungerar och vid korrekt dimensioner klarar att uppfylla kraven ställda i kravspecifikationen. Under tiden som konceptet togs fram och testades gjordes förbättringar på konstruktionen vilket resulterade till ett andra koncept. Den största skillnaden är att istället för att använda två klaffar som låser repet används nu bara en för att förenkla arbetet ytterligare samt minska på antal lösa delar i verktyget.   Om detta koncept tas i bruk kommer man att spara arbetstid och få en effektivare installation och dessutom kunna sälja verktyget till kunder där kunden själv installerar produkterna. Jag skulle rekommendera att gå vidare med konceptet enkelklaff då denna har en stabilare permanent rep-infästning, mindre lösa delar och förmodligen mer lättarbetat under installation. / This bachelor thesis called “Product development of rope attachment for marine mooring systems” is done in cooperation with Seaflex AB and is a product development of an already existing component in the company product range. The company who mainly targets mooring systems in marinas with flexibility and sustainability. They are looking for a more efficient way of attaching rope in the marina without compromising the products reliability.   In agreement with the project supervisor at Seaflex AB the decision after presenting different concepts went towards a development of a tool that applies to the rope attachment. A concept in Solid Works 3D was created along with blueprints for a tool that was going to be easy to move from different rope attachments. The tool consists of two flaps that can rotate on axles supported by two frame blocks, one on each side of the rope attachment. To be able to get the dimensions necessary for blueprints of the wings a pressure test was done on the rope in a tensile testing machine. From this extracted data there is a coalition between force and how much the rope is pressed together. A function prototype adapted for the tensile testing machine was made to verify that the concept would work. The function prototype had to be tested with different dimensions than the concept blueprints. The tensile testing on the function prototype was run in two different tests with different dimensions and showed results indicating that the function of the concept was working and with the correct dimensions could live up to the specifications set for the project. During the manufacturing and testing of the function prototype there was improvements being done and resulted in a second concept. The biggest difference to this new concept is that instead of using two wings to lock the rope there is only one, this to improve working with the concept tool and having fewer lose parts.   If one of these concepts is being put to work in the future, there will be improved installation time and more efficient installation on site. The product can also be sold to customers who choose to install the mooring systems themselves. I would recommend for further work on this project to proceed with the mono wing. This because of the more solid permanent rope attachment, less parts and probably easier to work with during installation.
63

Standardization and modularization of Handling system : Optimization of choice of roller conveyors andloading / unloading tables for beam handling

Corti, Giulia January 2019 (has links)
This project was commissioned by Ficep S.p.a. and performed in the field of product development with the aim of developing a method for the revision of product architectures in standardized modular configurations.The handling system for profiled beams has a generally well-established structure and technology among all main competitors in the mechanical carpentry sector, for this reason the key to success in the market is the optimization of the components to minimize redundancies and the ability to promptly satisfy the variegated customers’ demands while still keeping competitive prices.The major problem in the layout of these systems is the absence of standard rules or mathematical models, relaying mostly on the empirical norms derived from the experience of the designer, thus generating confusion and variants’ proliferation.For this reason, a standardized and optimized model for generating appropriate configurations according to functional specifics is the final goal of this work.To hit this target the development process has been analysed and reviewed all the way from the customer offer request to final layout definition, passing through the definition of the technical specifics, architecture of the handling system and inner structure of its components.The final result is a configurator that, taking the technical specifications of the client as input data, dynamically calculates the structure of the handling system adjusting even the composition of the elements it is made up of and their position for the layout.As a side project the configurator was used to create a model for cost estimation of the handling system in stages prior to the CAD design of its layout.
64

Evaluering av självlåsande gängor / Evaluation of self-locking threads

Olofsson, Anton January 2019 (has links)
Thread-locking adhesive is a common component for many manufacturers, due to its protection against vibrations and slipping in screw joints. However, this does not work as desired on stainless steel materials. The purpose of this work is to evaluate if self-locking threads can replace thread locking adhesive to ensure the quality in the screw joints and reduce assembly times. In this work, a method for testing the loosening torque has been designed, manufactured and implemented for self-locking threads (SELF-LOCK) and for threads with standard base profile and thread-locking adhesive (Loctite) applied. The design applied to the test consists of a disc of stainless steel with a thickness of 26 mm. The disc is machined with threaded holes for SELF-LOCK threads and threads with standard base profile. The sizes of the holes are M6, M8, M10, M12 and M16. All sizes are applied for both thread locking systems. The test is based on investigating the two different thread-locking systems loosening torque in the case of pre-tensioned joints, with a bias of 73% of the yield strength for 8.8 strength class. Measuring equipment in this test is a digital spring scale attached to a joint breaker bar. The distance from the screw center to the spring scale attachment to the joint breaker bar is 290 mm. All screws are mounted with an axial bearing between the goods and the screw head in order to ignore the screw head friction. After analysis of the result, it can be noted that SELF-LOCK threads do not provide higher loosening torques than coarse pitch metric threads with Loctite applied. The difference in percentages falls to an average of 12% higher to Loctite's advantage. However, the comparison analysis shows an advantage for SELF-LOCK where among other things, the assembly time for retrieving and applying Loctite took 23 seconds. Which is the time that can be saved if SELF-LOCK is implemented. Although the SELF-LOCK threads did not meet the requirement for loosening torques, I still want to see that this is further investigated due to the fact that the SELF-LOCK system is, among other things, better in environmental and work environment viewpoints, and also in terms of time. This gives great benefits to people who work in production where Loctite is used, but it can also provide economic benefits for the company on a long-term basis. For example, a more economical overview should be included in a wider investigation as well as more tests of mechanical properties such as vibration tests should be carried out. / Gänglåsningsadhesiv är en vanlig komponent hos många tillverkare för att skydda mot vibrationer och glappning. Detta fungerar dock inte som önskat på rostfritt stål. Syftet med arbetet är att utreda om självlåsande gängor kan ersätta gänglåsningsadhesiv för att säkerställa kvalitén i förbandet samt minska monteringstider. I detta arbete har en metod för testning av uppdragningsmoment konstruerats, tillverkats och genomförts för självlåsande gängor (SELF-LOCK) samt för gängor med standardbasprofil och gänglåsningsadhesiv (Loctite) applicerat. Konstruktionen som tillämpats till testet är bestående av en skiva rostfritt stål med en godstjocklek på 26 mm. Skivan är bearbetad med gängade hål för SELF-LOCK gängor samt gängor med standardbasprofil. Storlekarna på hålen är M6, M8, M10, M12 och M16. Samtliga storlekar är tillämpade för båda gänglåsningssystemen.Testet utgår ifrån att undersöka de två olika gänglåsningssystemens uppdragningsmoment vid förspända förband, med en förspänning på 73 % av sträckgränsen för 8.8 hållfasthetsklass.Mätutrustning i testet är en digital fjädervåg fäst i ett ledhantag. Avståndet från skruvenscentrum till fjädervågens infästning på ledhantaget är 290 millimeter. Alla skruvar lagras med ett axiallager mellan gods och skruvhuvud för att kunna bortse från skruvskallsfriktionen. Efter analys av resultatet, kan det konstateras att SELF-LOCK gängor inte ger högre uppdragningsmoment än grovdelad metriska gängor med Loctite applicerat. Skillnaden i procent hamnar på ett snitt av 12 % högre uppdragningsmoment till Loctites fördel. Jämförelseanalysen visar dock en fördel för SELF-LOCK där bland annat monteringstiden för att hämta och applicera Loctite tog 23 sekunder. Vilket är tid som kan sparas om SELF-LOCK implementeras.Även om SELF-LOCK gängorna inte uppfyllde kravet för uppdragningsmomentet så ser jag ändå att detta utreds vidare då SELF-LOCK systemet bland annat är bättre ur miljö- och arbetsmiljösynpunkt samt även tidsmässigt fördelaktigt. Detta ger stora fördelar för människor som jobbar i produktion där Loctite används men det kan även ge ekonomiska fördelar för företaget på långsikt. Förslagsvis bör en mer ekonomisk översikt ingå i en vidare utredning samt även fler tester av mekaniska egenskaper såsom vibrationstest genomföras.
65

Mätning av restspänning i kromoxid : En jämförelse mellan krom och kopparstrålning i röntgendiffraktion / Measurement of residual stress in chromium oxide coating : A comparison between Cr and Cu X-ray diffraction

Sjöström, Viktor January 2019 (has links)
A doctor blade among other applications is used in the paper industry, were its main purpose is to separate paper sheet from a drying cylinder. During spraying, the blade is exposed to wear by its continuous contact with the moving cylinder. The blade has been sprayed with a chromium oxide coating to withstand wear. During the application of the coating, residual stresses are built in, which influence the doctor blade performance. One method to determine residual stresses is to use X-ray diffraction, were the choice of X-ray source is crucial for receiving good measurement results. This thesis covers a comparison if a chromium or a copper X-ray source will give the best results when determining of residual stresses in the doctor blade. The thesis also includes measurement of residual principal stresses and their directions in the doctor blade in different conditions. The result show that copper as the X-ray source, and the 2𝜃 diffraction peak at 125° proved to be the best choice. The largest principal stress was found in the doctor blade directly following the plasma spraying of the coating. The stress was measured to 122,6 𝑀𝑃𝑎 and the direction was orthogonal to the blades longer side. / Ett schaberblad används bland annat inom pappersindustrin där dess huvudsakliga uppgift är att separera pappersmassa från en torkcylinder. Bladet utsätts för nötning och har försetts med en belagd yta av kromoxid. Under appliceringen av kromoxid skiktet byggs det inre spänningar som förkortar livslängden. En metod för att undersöka restspänningar är röntgendiffraktion där val av strålkälla är avgörande för resultatet. I denna examensuppsats jämfördes det mellan koppar och krom om vilken strålkälla som gav bäst resultat vid mätning av restspänningar i kromoxid. En vidare undersökning utfördes för att mäta storlek och riktning av huvudspänning på schaberblad i olika tillstånd från tillverkningsprocessen. Koppar visade sig ge bättre resultat i kromoxid då bakgrundsstrålningen var lägre, mindre spridning av mätdata och dess diffraktionstopp befann sig över 125°. Störst restspänning visade sig det blad ha vars tillstånd var endast plasmasprutad, vilket uppmättes till 123 𝑀𝑃𝑎 med riktning ortogonal mot bladets långsida.
66

Ledlösning till Kiruna Wagons Helix Dumper Wagon / Hinge Solution for Kiruna Wagons Helix Dumper Wagon

Petersson, Jonathan January 2016 (has links)
A high degree of wear has been identified in the hinge between load cube and underframe on one of Kiruna Wagons freight cars. The wagon is mainly used in the transport of iron ore, which means that it operates in a very dusty environment. The excessive wear results in an increased service demand and high downtime of the wagon. To reduce the need for service and thereby increase the availability of the wagon the cause of the high wear is to be determined. The report includes an analysis of the current hinge, load cases have been developed and strength simulations have been performed. The results of the calculations from the current hinge have been compared to studies of the hinge in reality to determine the conditions applied when using the wagon. Subsequently, the load cases have been modified by demands from the company. Several concepts of new hinges have been developed to then undergo a selection process that identifies the concepts that are most likely to be working on large-scale production.After analysis of the current hinge, it was discovered that the contact pressure in the joints is too high. The contact surface is not sealed from the environment, allowing foreign particles to contaminate the contact surfaces. The company wishes that the new hinge will not require continuous lubrication, or require maintenance with short intervals. The life-expectancy on the exchangeable parts are set to half the life-expectancy of the complete wagon. The concept hinges’ contact surfaces are sealed with o-rings, the journal is a thick-walled tube instead of a solid. The axle rotates against a bushing of a polymeric material rather than, as before, directly against the steel in the seat. The separation of the two steel surfaces remedies the problems that have been observed at the existing hinge, such as adhesion and material transfer between the two surfaces. The design of the concept hinge for the outer and inner hinge is now more homogeneous than before. This allows the company to have to stock fewer unique components.
67

Kartläggning av knivhantering i saxar och rullmaskiner / Investigation of knife management and specific improvements on the management of knifes

Sandström, Jonathan January 2019 (has links)
This report is a summary of a project launched by Stora Enso Skutskär Bruk together with Karlstad universitet as a finishing element on a bachelor degree in mechanical engineering. Stora Enso have today a operationell production of papermass, but with a lot of opportunities for improvement on one of their blocks. A few of these elements are how the knives are being handled while changing and running them. This project have investigated parts that are involved with these knives and enlighten potential factors that might be the cause of the lack of functionality. After these factors has been enlighten, theoretical improvements has been made that the company can use in the future. One of the reasons that can be a part of the problem is how the operators handle the knives in the machine and the maintenance of the knives. Furthermore, the theoretical improvements have been focused on the flaws that was found under the investigation with methods like Lean and constant improvements.
68

Surf Leash : Product Development of the Cord and Assembly / Surf Leash : Produktutveckling av lina med tillhörande infästning

Fritz, Lukas January 2019 (has links)
This bachelor thesis treats the product development process in general and the product development of a surf leash in particular. The thesis mainly concerns the product development of the surf leash cord and assembly. The product development process was initiated in South Africa, where problems with the surf leashes provided on today’s market was experienced. They get worn out to quick and it is expensive to replace a complete surf leash, as it is not possible to replace a broken part individually. The product development project aimed to obtain a well-defined final concept with an associated technical requirement specification for the surf leash, within the given time frame. To do so, the product development process was divided into four different phases, project plan, market requirement specification, concept selection and technical requirement specification. During the project plan phase, a plan for the product development process was created. Necessary methods and tools were selected for respective phase and a time schedule was created. The market requirement specification is mainly based on a market survey which was performed. The market survey contributed with valuable information, which has been used throughout the complete product development process to increase the costumer value in an efficient way. The concept selection is based on the outcome of the idea generation process, which were generated with regard to the requirements and desires in the market requirement specification. Various matrices were used to narrow the range of possible solution and to find the optimal concept for the cord and assembly. The concept selection phase resulted in a cord with a core of an elastic material with a protective cover in a material with less elasticity. This is made to protect the inner core from getting stretched-out and not return to its original length, the outer cover can also be constructed to make the cord less prone to tangle. The assembly consists of a male connector with a small trace which is connected to a receiver with a double pin lock mechanism. This creates a module-based, rotational free assembly which is easy to attach and detach. Thus, the surf leash can be optimized after personal preferences and allows for a broken part to be replaced individually. The technical requirement specification is based on available information and can be used as a basis for future work with layout- and detail construction.
69

FEM Analytisk studie av kilar för riktverk : FEM Analytisk studie av konstruktionsändringar för delkomponenten kilkasset i riktverk 1, Formatsträcka 4 SSAB Borlänge

Eriksson Röhnisch, Kasper January 2019 (has links)
No description available.
70

Produktionsoptimering av en linje för tillverkning av rundknäcke : Barilla, Filipstad

Hämäläinen, Christian January 2019 (has links)
No description available.

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