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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.
1

MULTISCALE MODELING TECHNIQUES PERTAINING TO COMPOSITIONALLY GRADED MARTENSITIC STEELS

Cicoria, Robert January 2016 (has links)
The introduction of composition gradients into the already hierarchical structure of martensitic steel leads to difficulties in modeling that arise from events occurring in the material at different length scales. In this thesis we isolate the features that are important to describing the mechanical properties of martensite and constitutively couple them through their respective length scales. The idea of a representative volume element is rigorously explored in which the microstructure is represented through a Masing model as well as more advanced structures akin to a nanocomposite. As such, we are able to keep track of microscopic yielding and internal stress evolution at the smallest scales (nanoscale through microscale). With the use of representative volume elements, we are able to track events at the largest scale as well by freely being able to change scale. As such, macroscopic phenomenon such as: thermal fields, composition fields, macroscopic loads, and the associated macroscopic phase distributions and stress distributions are evaluated. We conclude by demonstrating the power of this modelling technique in the design and optimization of compositionally graded steel structures via virtual prototyping. / Dissertation / Doctor of Philosophy (PhD)
2

Compensation to Automate an External Glucose Level Management System for Diabetes Type 1 : Artificial Pancreas

Trygg, Sebastian January 2016 (has links)
This report takes an approach of laying the first steps to create an artificial pancreassystem as treatment for type 1 diabetes. This includes a thoroughly performedanalysis of the most intrusive physical factors, such as hormonal activity, time offset,errors of measurement and metabolism. Such factors raise a need forcompensation. A compensation that will enable the development of the link betweena continuous glugose monitoring(CGM)-device and an insulin infusion pump,a system that can be described as an Artificial Pancreas.Through analysis of measured glucose series, a mathematicalapproximation is presented to solve the time offset of CGM.The approximation gives sufficient results but with room for improvementFrom the analysis of affecting factors, a compensation model isdeveloped. The model is designed as a closed loop which is suitable for timecontinuous systems. The output of the compensation model equation presented here is adirective that would be read by an insulin pump.
3

Patienters upplevelse av e-hälsa som stöd för egenvård vid diabetes typ 2 / Patients' experience of using e-health in self-management support fortype 2 diabetes

Westerberg, Simon, Karlsson, Devi January 2021 (has links)
Bakgrund: Som en del i omvårdnaden av personer med diabetes typ 2 utgör egenvård den viktigaste åtgärden efter hälso- och sjukvårdens insatser. De senaste tjugo åren har stora framsteg gjorts inom användningen av e-hälsa som en del i egenvården och flera studier visar att det kan ha en avgörande roll i hanteringen av diabetes typ 2.  Syftet: Utforska patienters upplevelse i användningen av e-hälsa som stöd för egenvård vid diabetes typ 2. Metod: En litteraturöversikt genomfördes och datasökningar i PubMed och CINAHL utfördes. Åtta kvalitativa artiklar inkluderades i analysen som inspirerades av Elo & Kyngäs deduktiva metod för kvalitativ analys. En modifikation av Orems egenvårdsmodell användes där fem kategorier valdes utifrån stödet de utgjorde för patienten. Under analysen identifierades meningsenheter som sedan sorterades utifrån de fem kategorierna. Subkategorier formulerades för att tydliggöra specifika fenomen inom varje kategori. Resultat: Analysen visade hur e-hälsa bistod patienten: 1) genom att agera eller utföra, 2) genom att stödja, 3) genom att undervisa, 4) genom att vägleda och 5) genom att tillhandahålla en utvecklande miljö. Slutsats: Implementeringen av e-hälsa upplevdes gynna användarna och förbättra deras livskvalitet. Teknologiska svårigheter begränsade dock vissa användare från att utnyttja applikationerna till fullo. Detta och kostnaden för vissa e-hälsotjänster kommer behöva åtgärdas för att öka tillgängligheten för användarna och ytterligare studier behövs för att följa utvecklingen.
4

The Formation Mechanisms of Galaxy Tails: A Statistical and Case Study

Lu, Hong Yi January 2022 (has links)
Using a hydrodynamical smoothed particle hydrodynamics (SPH) zoom-in simu lation of a galaxy group, we present a set of tail identification methods, and study the statistical properties of galaxy tails and their correlations with their expected formation mechanisms. We have a sample of 4548 M > 108 M⊙ galaxies across 58 snapshots from z = 0.67 to z = 0. For each galaxy, we apply a series of velocity and density cuts to identify the tail. We observed no significant correlations between galaxy tail mass and ram pressure, though we note some issues with our sampling. Tracking four visually identified jellyfish galaxies over time showed some evidence of increased ram pressure driving ISM mass loss, as well as spikes in tail mass pre ceding spikes in ram pressure with temporal offsets ranging from 500 Myr to 2 Gyr. No correlation was found between ISM mass and tail mass. We track the tail gas of a particularly well defined jellyfish galaxy 3.2 Gyrs back in time. We find that a lower bound of 30% of the tail gas was never in the ISM. Distinguishing between former ISM tail material and never ISM-accreted tail material, we see evidence of temperature mixing with the IGM in the former. Velocity and radial trajectory maps show a sharp impulse of ∆v ≈ 50 km s−1 over 4 snapshots, affecting both the never ISM-accreted tail material and CGM material, with the former showing evidence of momentum mixing onto the former ISM material. Combined with ob servations of CGM stripping, we propose that a significant portion of galaxy tails consists of stripped CGM that got swept up into the stripped ISM / Thesis / Master of Science (MSc)
5

Ungdomars upplevelse av Dexcom G5s följarfunktion : En intervjustudie

Björk, Ellinor, Rudenholm Elow, Susanne January 2018 (has links)
Background: Dexcom G5, a continues glucose monitoring system, includes a follower function that gives people the possibility to see other people's glucose levels in real time. During the adolescents the metabolic control often deteriorate, When the responsibility for the diabetes care is shared between the parent and the youth there is better possibility to achieve a good metabolic control (Olinder, Nyhlin och Smider 2011). Purpose: The purpose of this study is to investigate how adolescents perceive the follower function in Dexcom G5. Method: A qualitative interview method with inductive onset. Eleven adolescents have been interviewed using a question guide with semi structured questions. The material was analysed with content analysis by Graneheim and Lundman (2014). The theoretic framework  used is person centred  care (Ekman et al., 2011). Result: The conclusion from the analysis were one theme, three categories and eight subcategories. The theme is a means of adolescents to liberation using the follower function. The categories are use of technology, safety and liberation. The adolescents had a positive perception of the follower function and they felt safe, especially during the night and when there was a risk for hypoglycaemia. They felt that their parents was safer which led to fewer diabetes related conflicts and more liberation. The adolescents felt that it was easier to get help with the self-care. Some could feel some restrictions to their integrity and they could experience some stress by being responsible for their self-care. Most did not perceive the follower function as offensive to their integrity. They could understand that their parents used it with their welfare in mind. Conclusion: The follower function can be helpful when adolescents gradually take responsibility for their self-care. It is useful both in that it makes the adolescents feel safe, but it also provides a means for parents to let go. There are times when the adolescents may feel supervised and the follower function restrict their integrity. In such cases good communication is important. This is where the diabetes nurse has an important role to play. / Bakgrund: Till Dexcom G5, en kontinuerlig glukosmätare, finns en följarfunktion som ger möjlighet att följa andras glukosvärden i realtid. Under adolescensen försämras ofta den metabola kontrollen. När ansvaret för egenvården delas mellan föräldrar och ungdomar finns det bättre förutsättningar för att god metabol kontroll uppnås (Olinder, Nyhlin och Smide 2011). Syftet: Syftet med denna studie är att undersöka ungdomars upplevelse av Dexcom G5s följarfunktion. Metod: En kvalitativ intervjumetod med induktiv ansats. Elva ungdomar har intervjuats med en frågeguide med semistrukturerade frågor. Materialet har analyserats med hjälp av innehållsanalys utifrån Graneheim och Lundman (2004). Den teoretiska referensram som använts är personcentrerad vård (Ekman et al., 2011). Resultat: Vid analysen framkom ett tema, tre kategorier och åtta subkategorier. Temat var ungdomars väg till frigörelse med hjälp av följarfunktionen, kategorierna var handhavande av teknik, trygghet och frigörelse. Ungdomarna var positiva till följarfunktionen och kände sig trygga framförallt på nätterna samt vid risk för hypoglykemier. De upplevde att deras föräldrar var tryggare, vilket ledde till färre diabetesrelaterade konflikter och en större frihet. Ungdomarna upplevde att de lättare kunde få hjälp med egenvården. Några kände sig delvis inskränkta i sin integritet, och kunde ibland uppleva det stressande att alltid ställas till svars för hur de skötte sin egenvård. De flesta upplevde dock att följarfunktionen inte var kränkande för deras integritet, de förstod oftast att föräldrarna använde sig av den med gott uppsåt. Slutsats: Följarfunktionen kan vara till hjälp för att ungdomarna successivt ska kunna ta över ansvaret för sin egenvård. Den är till nytta både för att ungdomarna ska känna sig trygga, men också för att föräldrarna ska våga släppa taget. Det fanns dock tillfällen då ungdomarna kände sig övervakade och att följarfunktionen inskränkte på deras integritet. I dessa fall framkom det att kommunikation var extra viktig. Här har diabetessjuksköterskan en viktig roll.
6

Rädsla för hypoglykemi : patientens strategier och oro vid kontinuerlig blodsockermätning / Fear of Hypoglycaemiasystem : patients´strategies and concerns with continuous glucose monitoring

Bredenberg, Ingela January 2013 (has links)
No description available.
7

Kontinuerlig glukosmätning för en bättre hälsa / Continuous glucose monitoring for a better health

Haddad, Jenny, Naser, Haneen January 2022 (has links)
Abstract Aim: The primary aim of this study was to investigate whether continuous glucose monitoring (CGM) can be used to control glucose levels and whether CGM can improve eating habits and physical activities for people who use this device. Method: The study had 6 participants, aged between 26 to 30 years. The study contained two parts, a digital form, and an interview. All participants completed different questionnaires about their experience with the Lifestyle Libre sensor that they had already used for two weeks or more. Results: CGM is an effective tool for improving people's health. All participants believe that CGM can help them avoid foods that are high in energy and can cause blood sugar to rise a lot. The majority of the participants felt no anxiety about eating patterns. On the other hand, it depended on the individual and their knowledge. The use of the CGM can be painful for some due to the sensor being inserted under the skin, usually on the back of the upper arm. However, this was not an obstacle for the participants in testing the system. One of six participants experienced pain due to the sensor, while all others ranged from slightly painful to no pain at all. Regarding the comfort of wearing the CGM for two weeks, we received different responses from the participants. Regarding activities, four of the six experienced no change in activities because they were already active before the use of the CGM. However, one of the six participants expressed a desire to have the system measure other biomarkers, such as blood oxygen levels, temperatures, etc. Conclusion: In conclusion, the CGM is an effective tool for assisting people in living healthier lives. / En relativt ny teknik är kontinuerligt glukosmättning (continuous glucose monitoring, CGM). Kontinuerlig glukosmättning är en av många självspårningsanordningar som har utvecklats och som är användbar inom bland annat hälsobranschen och för personer med diabetes. CGM är ett öppet system som gör att användaren kan följa upp och förstå hur kroppen reagerar på glukosnivåer. Genom ett öppet system kan blodsockernivån avläsas och därmed ge en varning i realtid. Detta kan exempelvis ge patienter med diabetes en större möjlighet till att ingripa och kontrollera sin diabetes. Det finns alltså många möjligheter med CGM-systemet och det kan uppmuntra många användare att övervaka sin blodsockernivå och göra justeringar mot en mer tillfredsställande. Detta är en intervjustudie och den undersöker hur CGM kan användas för att underlätta individens livsstil eftersom ändringar i människans kost kan ha stora konsekvenser för hälsan. Detta kan i sin tur minska användarnas risk att utveckla diabetes till exempel diabetes typ2. Syftet med studien var att undersöka om CGM kan användas för att kontrollera blodsockernivåerna, och om CGM kan förbättra kostvanor och fysisk aktivitet för personer som använder systemet. Detta kan leda till att utvecklingen av diabetes och andra relaterade sjukdomar kan förhindras. Avgränsningar för studien var att undersöka om CGM kan användas för att förbättra deltagarnas liv. I denna studie analyserade vi inte data från systemet utan vi analyserade den information som deltagarna hade givit till oss. Studien använder sig av sex olika deltagare som alla har använt CGM tidigare. En av dem har diabetes typ 1 och de andra fem deltagarna är helt friska. Studien har delats in i två steg, där det första steget var att skicka en enkät till alla deltagare. Det andra steget var ett digitalt möte för att få mer information samt diskutera svaren som vi redan hade fått från enkäten. Vi spelade in alla digitala intervjuer för att säkerställa att all given information fanns att tillgå senare vid behov. Vi delade sedan in de olika frågeställningarna i olika teman för att få en strukturerad helhetsbild. Utifrån detta kunde vi sedan analysera deltagarnas svar. Resultaten som vi fick från denna studie var positiva. CGM är ett effektivt hjälpmedel som kan användas för att förbättra människors liv genom att hjälpa dem att leva mer hälsosamt. Alla deltagarna anser att CGM kan hjälpa dem att undvika kost som är energirik och som kanorsaka att blodsockernivån stiger mycket och hastigt. Majoriteten av deltagarna kände ingen ängslan kring ätmönster, men det berodde till stor del på individen själv och dennes kunskap. Användningen av CGM kan vara smärtsamt för vissa på grund av att en sensor sättas in under huden, vanligtvis på baksidan av överarmen. Däremot var detta inget hinder för deltagarna att testa systemet. En av sex deltagare upplevde smärta på grund av sensorn medan alla andras upplevelser varierade mellan lite smärtsamt till ingen smärta alls. När det gäller hur bekvämt det är att bära CGM under två veckor, fick vi olika svar från deltagarna. Gällande fysisk aktivitet upplevde fyra av sex ingen ändring eftersom de redan var aktiva innan användningen av CGM. Deltagarna önskade att systemet kunde mäta andra biomarkörer liksom syrenivå i blod, temperatur och liknande. Slutsatsen vi kom fram till med denna studie var att CGM är ett användbart system som kan hjälpa individer att leva mer hälsosamt. För att kunna få en bättre förståelse för hur ämnesomsättningen fungerar i kroppen kan man behöva använda CGM under mer än två veckor.
8

Continuous Glucose Monitoring and Tight Glycaemic Control in Critically Ill Patients

Signal, Matthew Kent January 2013 (has links)
Critically ill patients often exhibit abnormal glycaemia that can lead to severe complications and potentially death. In critically ill adults, hyperglycaemia is a common problem that has been associated with increased morbidity and mortality. In contrast, critically ill infants often suffer from hypoglycaemia, which may cause seizures and permanent brain injury. Further complicating the matter, both of these conditions are diagnosed by blood glucose (BG) measurements, often taken several hours apart, and, as a result, these conditions can remain poorly managed or go completely undetected. Emerging ‘continuous’ glucose monitoring (CGM) devices with 1-5 minute measurement intervals have the potential to resolve many issues associated with conventional intermittent BG monitoring. The objective of this research was to investigate and develop methods and models to optimise the clinical use of CGM devices in critically ill patients. For critically ill adults, an in-silico study was conducted to quantify the potential benefits of introducing CGM devices into the intensive care unit (ICU). Mathematical models of CGM error characteristics were implemented with existing, clinically validated, models of the insulin-glucose regulatory system, to simulate the behaviour of CGM devices in critically ill patients. An alarm algorithm was also incorporated to provide a warning at the onset of predicted hypoglycaemia, allowing a virtual dextrose intervention to be administered as a preventative measure. The results of the in-silico study showed a potential reduction in nurse workload of approximately 75% and a significant reduction in hypoglycaemia, while also providing insight into the optimal rescue dose size and resulting dynamics of glucose recovery. During 2012, ten patients were recruited into a pilot clinical trial of CGM devices in critical care with a primary goal of assessing the reliability of CGM devices in this environment, with a specific interest in the effects of CGM device type and sensor site on sensor glucose (SG) data. Results showed the mean absolute relative difference of SG data across the cohort was between 12-24% and CGM devices were capable of monitoring some patients with a high degree of accuracy. However, certain illnesses, drugs and therapies can potentially affect sensor performance, and one particular set of results suggested severe oedema may have affected sensor performance. A novel and first of its kind metric, the Trend Compass was developed and used to assesses trend accuracy of SG in a mathematically precise fashion without approximation, and, importantly, does so independent of glucose level or sensor bias, unlike any other such metrics. In this analysis, the trend accuracy between CGM devices was typically good. A recent hypothesis suggesting that glucose complexity is associated with mortality was also investigated using the clinical CGM data. The results showed that complexity results from detrended fluctuation analysis (DFA) were influenced far more by CGM device type than patient outcome. In addition, the location of CGM sensors had no significant effect on complexity results in this data set. Thus, while this emerging analytical method has shown positive results in the literature, this analysis indicates that those results may be misleading given the impact of technology outweighing that of physiology. This particular result helps to further delineate the range of potential applications and insight that CGM devices might offer in this clinical scenario. In critically ill infants, CGM devices were used to investigate hypoglycaemia during the first 48 hours after birth. More than 50 CGM data sets were obtained from several studies of CGM in infants at risk of hypoglycaemia at the Waikato hospital neonatal ICU (NICU). In light of concerns regarding CGM accuracy, particularly during the first few hours of monitoring and/or at low BG levels, an alternative, novel calibration scheme was developed to increase the reliability of SG data. The recalibration algorithm maximised the value of very accurate calibration BG measurements from a blood gas analyser (BGA), by forcing SG data to pass through these calibration BG measurements. Recalibration increased all metrics of hypoglycaemia (number, duration, severity and hypoglycaemic index) as the factory CGM calibration was found to be reporting higher values at low BG levels due to its least squares calibration approach based on the assumption of a less accurate calibration glucose meter. Thus, this research defined new calibration methods to directly optimise the use of CGM devices in this clinical environment, where accurate reference BG measurements are available. Furthermore, this work showed that metrics such as duration or area under curve were far more robust to error than the typically used counted-incidence metrics, indicating how clinical assessment may have to change when using these devices. The impact of errors in calibration measurements on metrics used to classify hypoglycaemia was also assessed. Across the cohort, measurement error, particularly measurement bias, had a larger effect on hypoglycaemia metrics than delays in entering calibration measurements. However, for patients with highly variable glycaemia, timing error can have a significantly larger impact on output SG data than measurement error. Unusual episodes of hypoglycaemia could be successfully identified using a stochastic model, based on kernel density estimation, providing another level of information to aid decision making when assessing hypoglycaemia. Using the developed algorithms/tools, with CGM data from 161 infants, the incidence of hypoglycaemia was assessed and compared to results determined using BG measurements alone. Results from BG measurements showed that ~17% of BG measurements identified hypoglycaemia and over 80% of episodes occurred in the first day after birth. However, with concurrent BG and SG data available, the SG data consistently identified hypoglycaemia at a higher rate suggesting the BG measurements were not capturing some episodes. Duration of hypoglycaemia in SG data varied from 0-10+%, but was typically in the range 4-6%. Hypoglycaemia occurred most frequently on the first day after birth and an optimal measurement protocol for at risk infants would likely involve CGM for the first week after birth with frequent intermittent BG measurements for the first day. Overall, CGM devices have the potential to increase the understanding of certain glycaemic abnormalities and aid in the diagnosis/treatment of other conditions in critically ill patients. This research has used a range of prospective and retrospective clinical studies to develop methods to further optimise the use of CGM devices within the critically ill clinical environment, as well as delineating where they are less useful or less robust. These latter results clearly define areas where clinical practice needs to adapt when using these devices, as well as areas where device makers could target technological improvements for best effect. Although further investigations are required before these devices are regularly implemented in day-to-day clinical practice, as an observational tool they are capable of providing useful information that is not currently available with conventional intermittent BG monitoring.
9

Låt inte gästen få sista ordet. : En kvalitativ studie om hur tjänsteföretag inom besöksnäringen arbetar och skulle kunna arbeta med Sociala medier, WOM och eWOM

Braunander, Joacim, Olofsson, Fredrik January 2015 (has links)
Internet har utvecklats snabbt de senaste åren och med utvecklingen har sociala medier blivit en stor del av Internet. Sociala medier innebär all form av kommunikation som sker på Internet så som exempelvis Tripadvisor, Facebook, Twitter, Booking.com eller Instagram. Konsumenter som väljer att kommentera upplevelser och produkter på sociala medier ökar. Enligt forskning så litar framtida konsumenter mer på andra konsumenters kommentarer än vad de litar på företagets marknadsföring över deras produkt/tjänst. Kommentarer som skrivs på olika sociala medier lämnas ofta obesvarade av tjänsteföretagen. De kommentarer som lämnas på sociala medier har en stor effekt på framtida konsumenters köpbeslut. Den form av kommunikation som gästerna förmedlar på sociala medier kallas electronic Word-of-mouth eller eWOM. Vilket ledde oss in på att genomföra en studie som undersöker hur tjänsteföretag tar sig an och hur de skulle kunna arbeta med kommunikation genom WOM, eWOM och sociala medier. Vi undersökte detta genom att göra en jämförande studie mellan olika hotell i Umeå. En modell med fyra olika steg skapades för att ta fram en eventuell kommunikationsprocess till tjänsteföretagen. Modellen lägger grund för den undersökning som vi genomför vid insamlandet av data.  Undersökningen gjordes som en kvalitativ forskning med ett avsiktligt urval där vi intervjuade en respondent för respektive företag. Undersökningen visade att det finns en skillnad mellan hur och till vilken grad tjänsteföretagen i Umeå använder sig av eWOM och sociala medier i sin kommunikation med konsumenterna Många tjänsteföretag skulle kunna förbättra det operativa arbetet med WOM, eWOM och sociala medier.
10

Self-Management Among Pre-teen and Adolescent Insulin Pump Users (SPIN)

Faulds, Eileen 11 September 2020 (has links)
No description available.

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