Bakgrund: Medkänsla är en hörnsten i omvårdnad. En del av att visa medkänsla är att dela andra personers lidande. Vid compassion fatigue förlorar sjuksköterskan förmågan att visa medkänsla och får därmed svårt att möta lidande. Compassion fatigue har en negativ inverkan på sjuksköterske- och patientrelationen såväl som sjuksköterskans egna fysiska och psykiska hälsa samt förändrar hur sjuksköterskan ser på sin roll och på yrket. Syftet med litteraturstudien var att belysa sjuksköterskans upplevelse av compassion fatigue. Metod: En litteraturstudie genomfördes med kvalitativ ansats och tio artiklar inkluderades i resultatet. Databassökningarna gjordes i databaserna Cinahl och Pubmed. SBU:s granskningsmall för kvalitativ forskningsmetod användes vid kvalitetsgranskningen och för analysen användes Popenoes manual för dataanalys av litteraturstudier. Resultat: Två kategorier framkom: Compassion fatigue på arbetet och compassion fatigue under ledig tid samt nio subkategorier: tömd på energi, känslor av otillräcklighet, sorg vid patienters bortgång, förlorad medkänsla i mötet med patienten, förändringar av den professionella rollen, förändrad syn på sjuksköterskeyrket, gränsen mellan arbete och fritid suddas ut, trötthet i själen och mindre energi för personliga relationer. Konklusion: Vid compassion fatigue upplever sjuksköterskan att tillvaron förändras och hälsan försämras. När sjuksköterskor inte förmår möta sitt eget lidande förlorar de förmågan att möta och lindra patienters lidande och förmågan att visa medkänsla försvinner. När förmågan att visa medkänsla går förlorad kan patienters smärta och stress öka samt patienters hälsa försämras. / Background: Compassion is a cornerstone of nursing. Part of showing compassion is sharing the suffering of others. When affected by compassion fatigue the nurse loses the ability to show compassion. Compassion fatigue has a negative impact on the nurse and patient relationship as well as the nurse's own physical and mental health and changes how the nurse views her role and the profession.Aim: the aim of the literature review is to illuminate the nurse’s experience of compassion fatigue. Method: A literature review was conducted with a qualitative approach and ten articles were included in the results. The database searches were made in the databases Cinahl and Pubmed. SBU's review template for qualitative research methods was used in the quality review and for the analysis Popenoe´s manual for data analysis of literature studies was used. Result: Two categories emerged: Compassion fatigue at work and compassion fatigue during free time as well as nine subcategories: depleted of energy, feelings of inadequacy, grief at the death of patients, loss of compassion in the meeting with the patient, changes in the professional role, changed view of the nursing profession, blurring of the boundary between work and leisure, fatigue of the soul and less energy for personal relationships. Conclusion: For the nurse experiencing compassion fatigue the existence changes and health deteriorates. When nurses are unable to face their own suffering, they lose the ability to face and alleviate patients' suffering and feel compassion. When nurses' ability to show compassion is lost, patients' pain and stress can increase, and patients' health deteriorate.

The existence of a glycogen-sarcoplasmic reticulum has been demonstrated by a number of researchers. This complex is suspected to participate in the calcium uptake activities of the sarcoplasmic reticulum (SR). Removal of glycogen particles associated with this complex may alter the calcium handling abilities of the SR. This experiment sought to determine what effect exercise and treatment with a-amylase had on the abilities of the SR to regulate intracellular calcium ([Ca2+]i). Rats were either run on a treadmill for 60 min at a speed of 21 m/min and a 10% grade or were not exercised. Animals were then killed by decapitation after inhalation of CO2. Left and right gastrocnemius muscles were excised from both groups and underwent SR vesicle preparation to separate the heavy and light SR fractions (HSR and LSR respectively). Left hindlimb muscle homogenate also underwent 60 min incubation with a-amylase to digest glycogen before differential centrifugation. Treatment with a-amylase significantly depressed rate of calcium uptake by LSR and HSR fractions by 22.89% and 25.22% respectively (p<0.05). alpha-Amylase had no effect on SR's rate of calcium release. There was no effect of exercise on calcium uptake or release rates. Glycogen concentration associated with the SR was unaffected by either alpha-amylase treatment or exercise. These results indicate that treatment with alpha-amylase decreases the ability of the SR to sequester calcium ions. / Master of Science

Pressurized artificial muscles show promise in both standard aircraft actuation operations and in morphing structures as an alternative to currently used actuation systems due to their high power-to-weight ratio. Pressurized artificial muscles have already demonstrated the necessary force production to be utilized as an alternative actuation mechanism. In order to better understand the feasibility of using pressurized artificial muscles as a standard actuation mechanism it is necessary to determine the life cycle of pressurized artificial muscles under high pressures, loads, and strains, and how muscle geometry and materials effect the life cycle of the artificial muscle. This thesis presents a study to determine the fatigue characteristics of pressurized artificial muscles to address the issues noted above. The life cycle of the pressurized artificial muscle is examined at high internal pressures and high strains. The materials composing the pressurized artificial muscle, and the artificial muscle geometry are changed throughout the study to determine their effect on the life cycle of a pressurized artificial muscle. Finally a morphing aileron utilizing pressurized artificial muscles as the actuation mechanism is fatigue tested. Fatigue testing results show that pressurized artificial muscle fatigue life is dependent on both actuator materials and geometry. Latex rubber bladders were shown to perform better than bladders of other materials. Increasing the wall thickness of the latex bladder increased the life cycle of the pressurized artificial muscles. Additionally, casting the pressurized artificial muscle in a cylindrical polyurethane resin matrix increased the life cycle of the actuator, and increasing the diameter of this resin matrix further increased the life cycle of the actuator. / Master of Science

Fatigue during exercise is associated with reduced muscle glycogen. However, evidence linking glycogen content to fatigue is lacking. In this study we examined whether reduced muscle glycogen content limited SR function or muscle performance. Two groups of female Sprague-Dawley rats were fasted for 24 hr and exercised for 90 min to reduce muscle glycogen; rats fasted after exercise formed the low glycogen (LG) group. Rats in the high glycogen (HG) group were allowed free access to food and a 5% sucrose solution. The LG group had 42% less muscle glycogen and 90% less glycogen associated with the sarcoplasmic reticulum (SR) than the HG group. Notably, time to exhaustion during a subsequent treadmill run (21 m/min at 10% grade) was markedly lower in the LG group (35 vs. 166.75 min). Despite less glycogen, the LG group had a higher SR Ca2+ uptake rate (45%) and Ca2+-stimulated ATPase activity (51%) possibly due to a 33% greater SERCA content. Surprisingly, in situ gastrocnemius initial twitch and tetanic forces were not different between groups although the rates of relaxation were higher in the LG group. The force responses to fatigue-inducing stimulus trains (20 Hz for 333 ms every 1 sec for 30 min) also were similar for both groups as were twitch and tetanic forces in the fatigued state. These results suggest that despite reduction in exercise performance, reduced muscle glycogen does not limit muscle performance or SR function. / Ph. D.

This study examined the effects of a sports drink on the performance of young soccer players. Ten competitive young male soccer players, ages 10 and 11, performed two experimental trials while consuming 32 ounces of either a sports drink (G)- Gatorade or a placebo (P)- Crystal Light in a double-blind, crossover design. Both trials consisted of a 15-minute warm-up period, a pre and post exercise test protocol and a 40-minute indoor scrimmage with a five-minute half time. The assigned fluid was consumed just prior to the warm-up, pre-test protocol, scrimmage and post-test protocol as well as during the half time of the scrimmage. The exercise tests included six activities such as shooting velocity, dribbling, passing, jumping, backward running, and sprinting in order to measure skill, agility, power, and speed. The results showed that due to the interaction of the 40-minute scrimmage and the consumption of Gatorade, the post-test shot velocity measurement was significantly (p<0.01) lower for P while G remained similar to the pre-test measurement. Also, there was a significant (p<0.05) decrease in the number of jumps completed for both P and G during the post-test jumping exercise when compared to the pre-test measurement. However, there were no significant difference of treatment, time and/or their interaction for the dribbling, passing, backward running, and sprinting. Many possible reasons may account for this lack of effect. 1) Muscle glycogen may not have been substantially depleted, possibly because the prescribed exercise during the trial was not intense or long enough. 2) Prior to the experimental trials, muscle glycogen stores were sufficient where no additional CHO was necessary (due to the subject's diet on the day of the trial or the short fast prior to the experimental trials). 3) Alternative mechanism, such as increased lactate production or dehydration and not muscle glycogen depletion, may be the cause of impaired skills. 4) A child's increased fat utilization allows for less of a need for manipulation of glycogen stores. / Master of Science

Twist Capsules are rotating electrical connections that are used when low noise electrical signals are required between a stationary connector and a mechanically oscillating one. Twist capsules are used throughout industry especially in areas that require exceptionally clean signals such as the space satellite industry and military applications. Due to the high cost of replacing parts on satellites launched into space and life-sustaining aspects of military applications, accurate modeling of these devices is essential to predict their behavior. Clock spring twist capsules use a flex tape, copper traces between two layers of Kapton, which rolls onto itself tightening against the shaft at one extreme and rolling out against the frame at the other extreme. This cyclic tightening and loosing can cause stresses on these flex tapes consequently, resulting in their failure due to fatigue. Therefore, it is imperative that some method be used to estimate the stresses in the flex tape in order that the optimal design parameters may be calculated. The natural progression from estimating the stresses is to predict the life of the twist capsule. Current techniques involve iteratively building physical models and heritage (what has worked in the past will work in the future) to build twist capsules. This methodology has been sufficient, but a large factor of safety is used during design to cover the lack of assurance in the method. This thesis proposes a new design method using clock spring equations to estimate the torque in twist capsules and the stresses induced into the flex tapes. This new design method accurately predicts operating range, torque, and stress in the normal operating range of the twist capsule sufficient enough for design purposes in a fraction of the amount of time it would normally take to design a twist capsule. / Master of Science

L’objectif général de ce travail doctoral était d’étudier les effets de la fatigue (physique et mentale) sur le contrôle postural. Tout d’abord, les effets de la fatigue musculaire du quadriceps fémoral induite par des contractions volontaires et des contractions électro-induites ont été comparés. Les résultats ont montré que des contractions volontaires altéraient davantage le contrôle postural que des contractions électro-induites pour une perte de force musculaire équivalente. Ceci s’expliquerait par la présence d’une fatigue centrale après les contractions volontaires, ainsi qu’une sollicitation différente des fibres musculaires entre les deux modalités de contraction. Des mécanismes compensatoires seraient mis en œuvre après ces deux modalités de contractions fatigantes, mais de façon plus prononcée pour les contractions volontaires. Concernant la fatigue mentale, les effets d’une tâche cognitive exigeante et prolongée sur ordinateur (induisant un état de fatigue mentale) et d’un visionnage de documentaire (tâche contrôle) sur le contrôle postural ont été comparés. De prime abord, la fatigue mentale affecterait le contrôle postural en condition de privation visuelle, en réduisant l’efficacité des stratégies d’attention associatives. De façon surprenante, visionner un documentaire conduirait également à une altération du contrôle postural, potentiellement en raison du maintien prolongé d’une posture assise affaissée. La posture assise pourrait ainsi constituer un facteur confondant dans les protocoles expérimentaux comportant une évaluation posturale. Une analyse statistique de classification en cluster hiérarchique a permis de mettre en évidence des sensibilités différentes au sein des individus à l’égard de la tâche mentalement fatigante. Le niveau de fatigue mentale serait associé au niveau de dégradation du contrôle postural sur un support stable avec les yeux ouverts. La réalisation d’une tâche cognitive prolongée exigeant une attention visuelle soutenue face à un écran d’ordinateur provoquerait une fatigue visuelle. Cette fatigue visuelle affecterait différemment les individus. Elle toucherait plus particulièrement les sujets les plus dépendants des informations visuelles, pour lesquels le contrôle postural se dégraderait davantage que les autres individus. / The overall objective of this doctoral work was to study the effects of fatigue (physical and mental) on postural control. First, the effects of femoral quadriceps muscle fatigue induced by voluntary contractions and electro-induced contractions were compared. The results showed that voluntary contractions affected postural control more than electro-induced contractions for an equivalent loss of muscle strength. This could be explained by the presence of central fatigue after voluntary contractions, as well as a different strain on muscle fibres between the two modes of contraction. Compensatory mechanisms would be implemented after these two modes of tiresome contractions, but more pronounced for voluntary contractions. With regard to mental fatigue, the effects of demanding and prolonged cognitive computer work (inducing mental fatigue) and documentary viewing (task control) on postural control were compared. At first glance, mental fatigue would affect postural control in conditions of visual deprivation, reducing the effectiveness of associative attention strategies. Surprisingly, viewing a documentary would also lead to an alteration in postural control, potentially due to the prolonged maintenance of a collapsed sitting posture. Sitting posture could thus be a confounding factor in experimental protocols involving postural evaluation. A statistical analysis of hierarchical cluster classification revealed different sensitivities within individuals towards the mentally demanding task. The level of mental fatigue would be associated with the level of degradation of postural control on a stable support with eyes open. Performing a prolonged cognitive task requiring sustained visual attention to a computer screen would cause visual fatigue. This visual fatigue would affect individuals differently. It would particularly affect the subjects most dependent on visual information, for which postural control would be more degraded than other individuals.

Submitted in partial fulfilment of the requirements for the Degree of Master of Technology: Mechanical Engineering, Durban University of Technology, 2011. / The objective of the present study was to investigate if piezoelectric techniques or sensors can be used in monitoring structural degradation. The study considers experimental results and analytical modelling of a ductile structure under tensile and cyclic loading. Throughout the project the emphasis was placed on the effectiveness of strain measuring sensors. Conventional tensile testing was conducted using a Lloyds testing machine. The testing machine was calibrated to have a lateral movement of 2mm/min (tension force). Rectangular plates were pulled in tension until failure. From that experimental data was produced for a uni-axial loading system. Cyclic testing was carried out using an in-house designed and manufactured fatigue machine. It produced a reciprocating load (force) of 25rad/s on a rectangular plate. Two different sensor measuring instruments (strain gauge and piezoelectric) were used. The strain gauge sensor was attached to a specimen and connected to a Wheatstone bridge. The piezoelectric sensor was attached to the specimen and then linked directly to the capturing system. From these two sensors experimental results were obtained and compared. The mathematical relationships for the rectangular plates were formulated using effective stress-strain behaviour based on the elastic and plastic behaviour of the plates. The analytical and experimental results were compared. Results from this investigation show that piezoelectric sensors can be useful for measuring fatigue failure on a ductile material.

This doctoral thesis concerns fatigue of welded structures. Welding is one of the world’s most common joining methods and it is frequently used in several structural applications in many fields. Some examples are construction vehicles, loader cranes, trucks, busses, forestry and agricultural machines, bridges and ships. Since these structures are subjected to repeated loading, fatigue is the most common cause of failure. A novel numerical algorithm has been developed which assesses the welded surface and calculates and quantifies weld quality parameters and the presence of defects which are critical in fatigue applications. The algorithm is designed for implementation in serial production. It will provide robust and reliable feedback on the quality being produced, which is essential if high strength steels are utilized. Two welding procedures which can increase the weld quality in as welded conditions have been assessed. These procedures utilize welding in different positions and pendling techniques, which can be accomplished using the existing welding equipment. It was found that by using these methods, the fatigue strength can be increased compared to normal weld quality. Furthermore, two fatigue assessment methods ability to account for increased weld quality in low cycle and high cycle fatigue applications has been studied. One of these methods showed sufficient accuracy in predicting the fatigue strength with small scatter and also account for increased weld quality. When implementing thinner high strength steels, the overall stress level in the structure increase. Therefore, other locations such as the steel cut edges may become critical for fatigue failure unless they are not designed and manufactured with the same quality as the welded joint. The influence of surface quality on cut edges was studied and the fatigue strength was estimated using international standards and a fatigue strength model for cut edges. / <p>QC 20160613</p> / WIQ / LIGHTSTRUCT / ONWELD

No description available.