Medicin och vaccin förvaras i injektionsflaskor. Flaskorna förseglas med gummiproppar somsitter kvar även när sjuksköterskan för nålen genom dem för att nå innehållet. Innan medicinkan lagras i injektionsflaskor måste gummipropparna steriliseras för att säkerställa att ingenkontaminering kan ske och att medicineringen för patienten är ren. Gummipropparna somanvänds inom läkemedelsindustrin behöver därmed genomgå en steriliseringsprocess. Iprocessen stoppas propparna in i Tyvek-Beta Bags och placeras på perforerade plåtar på envagn. Vagnen placeras i en autoklav som utsätter påsarna för ånga med temperaturer mellan121 och 134°C samt vakuum. Under steriliseringsprocessen utsätts påsen för spänningar ochblåses upp som en ballong vilket resulterar i påfrestning vid huvudet/öppningen.I projektet Beta Bag Retainer har en två studenter från Högskolan i Halmstad samarbetat medGetinge Sterilization AB utvecklat en låsanordning som låser fast Beta Bagen på plåten samt germöjlighet att optimera lasten och därmed öka kapaciteten under steriliseringsprocesserna.Projektet har genomförts genom användning av Set-based design och agil produktutveckling.Låsanordningen är användarvänlig, lätt att montera och anpassad efter Getinge Sterilizationsexisterande produkter samt en kravspecifikation. / Medicine and vaccines are stored inside injection vials. The bottles are sealed with rubber stoppersthat remain in place even when the nurse moves the needle through them to reach the contents.Before medicine can be stored in vials, the rubber stoppers must be sterilized to ensure that nocontamination can occur and that the medication for the patient is safe.The rubber stoppers used in the pharmaceutical industry need to go through a sterilization process.In this process, the stoppers are put into Tyvek bags called BetaBags and placed on perforatedshelves on a trolley. The trolley is placed inside an autoclave that exposes the bags to steam attemperatures between 121 and 134°C as well as vacuum. During the sterilization process, the bagis subjected to tension when inflated like a balloon which also is putting pressure on thehead/opening of the bag.In the Beta Bag Retainer project, the project group has developed a locking device that keeps thebag in place which gives the opportunity to optimize the load and thereby increase capacity duringthe sterilization process. The lock is user-friendly and mainly works with Getinge Sterilizationsexisting products. The project group has worked with Set-based Design and agile production todevelop a solution that achieves all the requirements and demands from the company. The solutionis a user friendly locking device, which is easy to keep clean and to assemble onto perforatedshelves.

Concierge medicine is a model of care in which patients pay an upfront annual membership fee to belong to the practice. In return for the fee the doctor is contracted to give the patient a more dedicated and individualized model of patient care. Concierge medicine was created out of the frustrations primary care physicians felt towards the restrictions place on them by insurance companies. Physicians want to be able to practice good medicine and not be buried in tedious paperwork that restricts the amount of time they can spend with patients. Physicians benefit because they able to spend more time with their patients, allowing them to establish relationships with their patients. Physicians are actually able to practice medicine and worry less about restrictions placed on them by insurance companies. They can practice preventative care which is a crucial part of their job. Their incomes are also protected because their salary is not regulated by the number of patients they see a day and the number of tests and labs they may run. Most importantly, physcian’s are much more satisfied with their jobs because of the time they are able to spend with the patients. Patients benefit even more than physicians. They can have long conversations with their physicians, rather than being rushed. When they need to see the doctor, patients are able to make same day appointments and avoid long wait times in the waiting room. Patients have 24/7 access to their physicians, so whenever a question or issue comes up, it can be addressed. Patients receive preventative care, to be proactive in preventing bad health outcomes for the future and undergo less unnecessary testing. There is much controversy with concierge medicine because many feel it is not ethical to provide better care for those who can afford concierge medicine. Proponents of concierge medicine argue that it is affordable to people from all socioeconomic statuses. Critics believe that concierge physicians are denying care to people of lower socioeconomic status, but most concierge physicians have a form of scholarship care in place for people who cannot afford the fee. While there is much controversy surrounding concierge medicine, there is not concrete evidence that is benefits patients or causes harm to the health care system. Many studies need to be done to determine its benefits. It is known that it does leave patients feeling much more satisfied with the quality of care, than when they received care in non-concierge practices. The real issue that needs to be addressed in the health care system is how to provide a quality of care similar to that provided by concierge physicians for everyone.

No description available.

O objetivo do estudo foi avaliar, comparativamente, a influência do cimento biocerâmico EndoSequence BC a diferentes cimentos endodônticos sobre a resistência de união do conjuno cimento resinoso/pino de fibra de vidro à dentina radicular. Setenta e dois dentes caninos selecionados tiveram a coroa seccionada transversalmente e o remanescente radicular padronizado em 17mm. O canal radicular foi preparado com Reciproc R50 e NaOCl 1%. Os espécimes foram distribuídos conforme o cimento obturador utilizado (n=12): G1-controle (sem cimento); G2- óxido de zinco e eugenol (EndoFill) G3- hidróxido de cálcio (Sealapex); G4- resina epóxi (AHPlus); G5-resina epóxi e hidróxido de cálcio (Sealer Plus) e G6- biocerâmico (EndoSequence BC). Decorridas 48h da obturação, as raízes foram desobturadas e preparadas para receber o pino de fibra de vidro. Após secagem do canal, os pinos foram cimentados com Panavia F 2.0. Dez raízes de cada grupo foram seccionadas transversalmente para obtenção dos slices. O primeiro slice de cada terço foi submetido ao teste de resistência de união (push-out) e padrão de falha. No segundo slice foi avaliada a interface adesiva dentina/cimento resinoso, por meio de microscopia de varredura confocal a laser (MVCL). Dois espécimes de cada grupo não tiveram o pino cimentado no canal radicular e foram destinados à microscopia eletrônica de varredura para observação de remanescente de material obturador na superfície dentinária. Os dados referentes à resistência de união foram submetidos ao teste Shapiro-Wilk, seguido de ANOVA two way. Os dados referentes à MVCL foram analisados pelo teste Kruskal-Wallis seguido pelo teste Dunn ( = 5%). Os grupos controle e AHPLus apresentaram os maiores valores de RU (p<0,05). Os cimentos EndoSequence BC, Sealer Plus e Sealapex apresentaram os valores intermediários de RU, sem diferença estatística entre eles. O cimento EndoFill apresentou os menores valores de RU com diferença estatisticamente significante em relação aos demais grupos (p<0,05). Quanto aos terços radiculares, os maiores valores de RU foram observados no terço cervical (p<0,05). As imagens de MEV demonstraram no geral, presença de poucos remanescentes de material obturador na superfície radicular em todos os grupos. Quanto a análise da interface cimento resinoso/dentina, a maioria dos grupos apresentou adaptação razoável, com exceção do EndoFill. Concluiu-se que os cimentos endodônticos Endosequence BC, Sealapex, Sealer Plus e EndoFill influenciaram negativamente a RU do conjunto pino/cimento resinoso à dentina radicular / The aim of this study was to compare the influence of EndoSequence BC bioceramic sealer on the bond strength (BS) of resin cement/fiber post in root canals filled with different sealers. The coronary of seventy-two canines were removed and the root length standardized at 17mm. The root canal was prepared with Reciproc R50 and 1% NaOCl. The specimens were distributed according to the filling material used (n=12): G1- control (no sealer); G2- zinc oxide and eugenol (EndoFill) G3- calcium hydroxide (Sealapex); G4- epoxy resin (AHPlus); G5- epoxy resin and calcium hydroxide (Sealer Plus) and G6- bioceramic (EndoSequence BC). Later forthy eight hours, the roots were prepared to insert the fiberpost. Fiberposts were attached with Panavia F 2.0. Ten roots of each group were sectioned transversely, obtaining slices of cervical, medium and apical root canal thirds. The BS of the first slice of each third was evaluated by push-out test and failures was analyzed by stereo microscope. The interface between dentin wall/resin cement of the second slice was evaluated by confocal laser microscopy (CLM). Two specimens from group were not restored with fiberpost, and assigned to scanning electron microscopy (SEM) to analyze the remaining material on the dentin surface. Data on the bond strength were submitted to the Shapiro-Wilk test, followed by two way ANOVA. The CLM data were submitted to the Kruskal-Wallis and Dunn tests ( = 5%). The control and AHPLus groups had the highest RU values (p <0.05). The EndoSequence BC, Sealer Plus and Sealapex sealers presented the intermediate values of RU, with no statistical difference between them. EndoFill sealer presented the lowest values of RU with a statistically significant difference in relation to the other groups (p <0.05). Regarding root thirds, the highest BS values were observed in cervical third (p <0.05). SEM images showed presence of few remaning filling material on the root surface in all groups. Regarding the dentine/resin cement interfaces analyzes most of the groups presented average adaptation, unless the G2. It was concluded that Endosequence BC, Sealapex, Sealer Plus and EndoFill endodontic sealers poor influenced the BS of the fiber post/resin cement in root canal dentin

Orientador: Rodolfo Bruniera Anchieta / Resumo: O objetivo deste trabalho foi avaliar “in vitro” e “in silico” a integridade estrutural da interface de cimentação, o comportamento biomecânico, e a resistência de união da interface dentina/cimento de diferentes técnicas de cimentação de pinos de fibra de vidro (PFV) em canais amplos. Para tanto, foram utilizados 33 incisivos bovinos. Após o tratamento endodôntico, os espécimes foram divididos aleatoriamente em três grupos (n=11): PCN- Pino convencional cimentado em dente com conduto normal; PCA- Pino convencional cimentado em dente com conduto amplo; PAA- Pino anatômico cimentado em dente com conduto amplo. Em seguida, foram executados os preparos intrarradiculares de acordo com cada grupo com brocas pré-estabelecidas, tratamento de superfície dos PFV (WhitePost nº3 DC, FGM) e cimentação dos mesmos com o cimento resinoso autoadesivo (Rely X U200, 3M ESPE). Então, 6 espécimes de cada grupo foram submetidos ao escaneamento em um microtomógrafo de alta resolução (SkyScan 1272) para avaliação da integridade, volume e presença de bolhas na interface de cimentação. Posteriormente, com base nos dados do µCT e imagens de microscopia (n=1), dois modelos tridimensionais de cada grupo foram confeccionados para a análise de elementos finitos, sendo que o primeiro foi considerado ideal (G1, G3 e G5), sem defeitos na interface, e o segundo continha as condições encontradas pela análise de µCT(G2, G4 e G6). Após o envelhecimento em estufa por 7 meses, todos os espécimes foram submetidos a... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to evaluate “in vitro” and “in silico” the structural integrity of the cementation interface, the biomechanical behavior and the bond strength of different fiberglass post cementation techniques in flared root canal. To this end, 33 bovine incisors were used. After the endodontic treatment, the specimens were randomly divided into three groups (n = 11): PCN - conventional post cemented in tooth with normal canal lumen; PCA- Conventional fiberglass post cemented in flared root canal; PAA- Fiberglass post relined with composite resin and cemented in flared root canal; Then, the intra-radicular preparations were performed according to each group with pre-established drills, surface treatment of PFV (WhitePost Nº. 3DC, FGM) and cementation with self-adhesive resin cement (Rely X U200, 3M ESPE). Then, 6 specimens from each group were submitted to scanning in a high resolution microtomograph (SkyScan 1272) to evaluate the integrity, volume and presence of bubbles at the cementation interface. Then, based on the μCT data and the microscopic images (n = 1), two three-dimensional models of each group were made to analyze finite elements, the first one being considered ideal (G1, G3 and G5), without interface defects and the second contained the conditions found by μCT analysis (G2, G4 and G6). After being stored for 7 months, all specimens were submitted to the pushout bond strength test (n = 10). Data were submitted to ANOVA with repeated measures and ... (Complete abstract click electronic access below) / Mestre

O objetivo foi avaliar a influência de variações no formato da férula dada por núcleo estojado sobre as tensões desenvolvidas na raiz em um modelo tridimensional de um segundo pré-molar superior submetido a quatro condições de carregamentos: cunha, alavanca vestibular, alavanca proximal e torção. Seis modelos foram confeccionados a partir das dimensões médias obtidas na literatura. Um deles representou o dente hígido, e outros cinco dentes restaurados com coroa e retentor intra-radicular fundido: um simulou núcleo simples, sem férula (E2A0), e em quatro modelos variou-se o tamanho do espelho (E) em 1/3 da espessura da parede radicular (E1) ou 2/3 (E2) e a altura (A) da férula foi equivalente a E1 (A1) ou a E2 (A2); ou seja: os modelos E1A1 e E2A2 tiveram 45º de inclinação do bisel da férula. Todas as estruturas foram consideradas homogêneas, isotrópicas e lineares elásticas. Os resultados permitem afirmar que a férula não parece necessária para melhorar a distribuição de tensões e que, exceto para o caso de carregamento longitudinal (que demonstrou ser o menos danoso), o cimento ficou submetido a tensões que justificam sua fratura e a dentina apresentou tensões de tração compatíveis com fraturas longitudinais (com início na crista óssea), especialmente para a alavanca vestibular. / The aim was to evaluate the influence of variations in the radicular ferrule format given by the casing core on stress developed in the root in a three-dimensional model of one upper second premolar submitted to four load conditions: wedge, vestibular lever, proximal lever and torsion. Six models were built according the average dimensions obtained from the literature. One of them represented the sound tooth, and other five restored teeth with cast radicular retainer and crown: one simulated simple core, without ferrule (E2A0), and in four models the mirror (E) size was varied in 1/3 of the radicular wall thickness (E1) or 2/3 (E2) and the ferrule height (A) was equivalent to E1 (A1) or E2 (A2); or be: E1A1 and E2A2 had 45º inclination of the ferrule bisel. All the structures were considered homogeneous, isotropic and linear elastic behavior. The results allow to affirm that the ferrule doesn\'t seem necessary to improve the stress distribution and that, except for the longitudinal load case (that demonstrated to be the least harmful), the cement was submitted to stress that justify his fracture and the dentine presented compatible tensile stress with longitudinal fractures (with beginning in the bone crest), especially for the vestibular lever.

O objetivo foi avaliar a influência de variações no formato da férula dada por núcleo estojado sobre as tensões desenvolvidas na raiz em um modelo tridimensional de um segundo pré-molar superior submetido a quatro condições de carregamentos: cunha, alavanca vestibular, alavanca proximal e torção. Seis modelos foram confeccionados a partir das dimensões médias obtidas na literatura. Um deles representou o dente hígido, e outros cinco dentes restaurados com coroa e retentor intra-radicular fundido: um simulou núcleo simples, sem férula (E2A0), e em quatro modelos variou-se o tamanho do espelho (E) em 1/3 da espessura da parede radicular (E1) ou 2/3 (E2) e a altura (A) da férula foi equivalente a E1 (A1) ou a E2 (A2); ou seja: os modelos E1A1 e E2A2 tiveram 45º de inclinação do bisel da férula. Todas as estruturas foram consideradas homogêneas, isotrópicas e lineares elásticas. Os resultados permitem afirmar que a férula não parece necessária para melhorar a distribuição de tensões e que, exceto para o caso de carregamento longitudinal (que demonstrou ser o menos danoso), o cimento ficou submetido a tensões que justificam sua fratura e a dentina apresentou tensões de tração compatíveis com fraturas longitudinais (com início na crista óssea), especialmente para a alavanca vestibular. / The aim was to evaluate the influence of variations in the radicular ferrule format given by the casing core on stress developed in the root in a three-dimensional model of one upper second premolar submitted to four load conditions: wedge, vestibular lever, proximal lever and torsion. Six models were built according the average dimensions obtained from the literature. One of them represented the sound tooth, and other five restored teeth with cast radicular retainer and crown: one simulated simple core, without ferrule (E2A0), and in four models the mirror (E) size was varied in 1/3 of the radicular wall thickness (E1) or 2/3 (E2) and the ferrule height (A) was equivalent to E1 (A1) or E2 (A2); or be: E1A1 and E2A2 had 45º inclination of the ferrule bisel. All the structures were considered homogeneous, isotropic and linear elastic behavior. The results allow to affirm that the ferrule doesn\'t seem necessary to improve the stress distribution and that, except for the longitudinal load case (that demonstrated to be the least harmful), the cement was submitted to stress that justify his fracture and the dentine presented compatible tensile stress with longitudinal fractures (with beginning in the bone crest), especially for the vestibular lever.

Introduction : Après un traitement orthodontique, la rétention (ou contention) est essentielle pour éviter les récidives vers la malocclusion initiale. Le fil de rétention lingual est un appareil fixe, relativement facile à installer et bien accepté par les patients pour maintenir la position finale des dents antérieures inférieures. Étant de plus en plus utilisé, il devient important de s’assurer de sa fiabilité pour la stabilité de l’alignement dentaire. Objectif : Le but de cette étude clinique randomisée prospective est de déterminer le taux de survie d’un fil lingual mandibulaire de rétention en comparant les méthodes de collage direct et de collage indirect à court et moyen termes. Méthodologie : L’échantillon est constitué de 117 patients consécutifs aléatoirement distribués dans 2 groupes : collage direct (n=58) et collage indirect (n=59). Les fils torsadés de diamètre 0,0175’’ sont préformés par un technicien de laboratoire soit selon la méthode de collage direct, soit selon la méthode de collage indirect. Une matrice de transfert en silicone assure le positionnement précis du fil lingual en bouche. Assure® et Filtek™ Flow ont été utilisés pour le collage direct. Filtek™ Flow, Assure®, and Sondhi™ ont été utilisés pour le collage indirect. Les fils de rétention ont été évalués pour le décollement, l’infiltration, la distorsion et le bris à 2 mois (T1) et 6 mois (T2). Résultats : À T1, le taux de survie du fil de rétention est de 90,2% pour le groupe de collage direct, comparativement à 79,5% pour le groupe de collage indirect (p=0,232). À T2, le fil est resté intact pour 74,1% des participants dans le groupe de collage direct et pour 70,0% des participants dans le groupe de collage indirect (p=0,481). Les différences ne sont pas statistiquement significatives entre les 2 groupes. La fréquence du décollement est plus haute que les autres problèmes enregistrés à T1 (p<0,022), représentant 85,7% des échecs. À T2, le décollement est plus fréquent que la distorsion ou le bris (p<0,04), mais pas statistiquement plus fréquent que l’infiltration (p=0,109). Il représente alors 86,4% des échecs. Conclusion : Le décollement est la principale cause d’échec d’un fil de rétention lingual. Il n’y a pas de différence statistiquement significative du taux de survie d’un fil lingual mandibulaire de rétention entre les techniques de collage direct et de collage indirect à court et moyen termes. / Background: The lingual wire has been shown to be an effective way to ensure the retention of the lower anterior segment after orthodontic treatment. As it is increasingly used, it is important to achieve proper bonding of the wire to ensure stability. Objective: The aim of this prospective randomized clinical study is to assess the short and medium term survival rate of the mandibular lingual retention wire using 2 different bonding techniques (direct and indirect). Materials and Methods: The sample of 117 consecutive patients was randomly distributed into 2 groups: direct bonding (n=58) and indirect bonding (n=59). The multi-strand twist wires (0,0175”) used were all preformed by a technician and prepared for either direct or indirect bonding technique with a transfer matrix. Assure® and Filtek™ Flow were used for direct bonding. Filtek™ Flow, Assure®, and Sondhi™ were used for indirect bonding. The lingual wires were evaluated for bonding failure, infiltration, breakage, and distortion at 2 months (T1) and 6 months (T2). Results: At T1, survival rate for the lingual wire was 90,2% for direct bonding and 79,5% for indirect bonding (p=0,232). At T2, the lingual wire was intact for 74,1% of the participants in the direct bonding group and 70,0% for the indirect bonding group (p=0,481). The differences between the 2 groups were not statistically significant. Debonding was more frequent than all other problems at T1 (p<0,022), accounting for 85,7% of the failures. At T2, debonding was more frequent than distortion and breakage (p<0,04), but not statistically more frequent than infiltration (p=0,109). It then accounted for 86,4% of the failures. Conclusion: Debonding is the main cause of failure for a lingual retention wire. There is no statistically significant difference in the survival rate of a lingual retention wire using direct and indirect bonding techniques in the short and medium term.

The problem addressed in this thesis is the delevitation modelling of an active magnetic bearing (AMB) supported rotor. A system model needs to be developed that models the highly non-linear interaction of the rotor with the backup bearings (BBs) during a delevitation event. The model should accurately predict forward and backward whirl as well as the system forces experienced. To this end, the severity of rotor delevitation events should be characterised. The contributions of the research include a more comprehensive model of a cross-coupled flexible rotor-AMB-BB system, a method to obtain repeatable experimental results, two methods for quantifying the severity of a rotor-drop (RDQ and Vval) and the simulation of forward whirl. A simulation model (BBSim) was developed to predict the behaviour of a rotor in rolling element BBs in an AMB system during a rotor delevitation event. The model was validated using a novel rotor delevitation severity quantification method (Vval) to compare experimental and simulated results. In this study the force impulse values as the rotor impacts the BBs are seen as critical to monitor, as an indication of rotor drop severity. The novel quantification method was verified by comparing the impulse values of delevitation events to the values obtained for the same delevitation events using the novel quantification method. The simulation model (BBSim) was developed by integrating and cross coupling various simpler models to obtain a model that could accurately predict the behaviour of a rotor during a delevitation event. A plethora of simulation results were generated for various initial conditions. The simulation results were used to perform a parametric study, from which the effects that certain design parameters have on the severity of rotor delevitation events are determined. The novel quantification method results presented in this research compared well to the impulse values. Since most AMB systems that have BBs do not have force measurement capabilities, the development of the novel quantification method enables the quantification of rotor drop severity solely based on position data. The simulation model BBSim was found to accurately predict the behaviour of a rotor during a delevitation event. The parametric study completed using BBSim revealed that the severity of rotor delevitation events is less sensitive to the bearing stiffness than the bearing damping. The parametric study also found that the severity of a delevitation event is slightly sensitive to the angle of delevitation. The friction factor between the rotor and the inner-race of the rolling element bearings moderately influences the severity of the rotor delevitation event. The inertia of the rolling element bearing’s inner-race and balls influences the behaviour in a complex manner, where the inertia should be kept as low as possible for actively braked rotors, and should be higher for free running rotors. The unbalance of the rotor plays a major role in the severity of rotor delevitation events. A rotor with a high unbalance usually tends to go into forward whirl, whereas low unbalance could promote the development of backward whirl if the inertia of the inner-race and the friction factor between the inner-race and the rotor are excessively large. Some of the recommended future work to be done on BBSim Include investigations into load sharing, various failure modes of AMBs, the effect that rotor circularity has on the stability of AMB control and an investigation into forward whirl. Envisaged improvements that can be made to BBSim are the inclusion of an axial rotor AMB and BB model, cross-coupled with the existing BBSim model. Other improvements could be the inclusion of thermal modelling and the ability to simulate other types of BBs. Future experimental work could include a comparison of simulated and experimental results of larger systems and using the developed quantification methods to refine the defined threshold values for the safe operation of AMB systems. / PhD, North-West University, Potchefstroom Campus, 2014 / Appendix C is attached seperately because of the size of the pdf (920 MB). If it is too large to download, please loan the hardcopy with the CD from the Loan desk in the Ferdinand Postma Library.

The problem addressed in this thesis is the delevitation modelling of an active magnetic bearing (AMB) supported rotor. A system model needs to be developed that models the highly non-linear interaction of the rotor with the backup bearings (BBs) during a delevitation event. The model should accurately predict forward and backward whirl as well as the system forces experienced. To this end, the severity of rotor delevitation events should be characterised. The contributions of the research include a more comprehensive model of a cross-coupled flexible rotor-AMB-BB system, a method to obtain repeatable experimental results, two methods for quantifying the severity of a rotor-drop (RDQ and Vval) and the simulation of forward whirl. A simulation model (BBSim) was developed to predict the behaviour of a rotor in rolling element BBs in an AMB system during a rotor delevitation event. The model was validated using a novel rotor delevitation severity quantification method (Vval) to compare experimental and simulated results. In this study the force impulse values as the rotor impacts the BBs are seen as critical to monitor, as an indication of rotor drop severity. The novel quantification method was verified by comparing the impulse values of delevitation events to the values obtained for the same delevitation events using the novel quantification method. The simulation model (BBSim) was developed by integrating and cross coupling various simpler models to obtain a model that could accurately predict the behaviour of a rotor during a delevitation event. A plethora of simulation results were generated for various initial conditions. The simulation results were used to perform a parametric study, from which the effects that certain design parameters have on the severity of rotor delevitation events are determined. The novel quantification method results presented in this research compared well to the impulse values. Since most AMB systems that have BBs do not have force measurement capabilities, the development of the novel quantification method enables the quantification of rotor drop severity solely based on position data. The simulation model BBSim was found to accurately predict the behaviour of a rotor during a delevitation event. The parametric study completed using BBSim revealed that the severity of rotor delevitation events is less sensitive to the bearing stiffness than the bearing damping. The parametric study also found that the severity of a delevitation event is slightly sensitive to the angle of delevitation. The friction factor between the rotor and the inner-race of the rolling element bearings moderately influences the severity of the rotor delevitation event. The inertia of the rolling element bearing’s inner-race and balls influences the behaviour in a complex manner, where the inertia should be kept as low as possible for actively braked rotors, and should be higher for free running rotors. The unbalance of the rotor plays a major role in the severity of rotor delevitation events. A rotor with a high unbalance usually tends to go into forward whirl, whereas low unbalance could promote the development of backward whirl if the inertia of the inner-race and the friction factor between the inner-race and the rotor are excessively large. Some of the recommended future work to be done on BBSim Include investigations into load sharing, various failure modes of AMBs, the effect that rotor circularity has on the stability of AMB control and an investigation into forward whirl. Envisaged improvements that can be made to BBSim are the inclusion of an axial rotor AMB and BB model, cross-coupled with the existing BBSim model. Other improvements could be the inclusion of thermal modelling and the ability to simulate other types of BBs. Future experimental work could include a comparison of simulated and experimental results of larger systems and using the developed quantification methods to refine the defined threshold values for the safe operation of AMB systems. / PhD, North-West University, Potchefstroom Campus, 2014 / Appendix C is attached seperately because of the size of the pdf (920 MB). If it is too large to download, please loan the hardcopy with the CD from the Loan desk in the Ferdinand Postma Library.