Saturation behavior of a Doppler broadened transition involving levels with closely spaced structure

Saturation behavior of Doppler broadened transition involving levels with closely spaced structur

A Hyperbaric Aerodynamic Levitator For Containerless Materials Research

A hyperbaric aerodynamic levitator has been developed for containerless materials research at specimen temperatures exceeding 2000 °C and pressures up to 10.3 MPa (1500 psi). This report describes the prototype instrument design and observations of the influence of specimen size, density, pressure, and flow rate on levitation behavior. The effect of pressure on heat transfer was also assessed by studying the heating and cooling behavior of levitated Al2O3 liquids. A threefold increase in the convective heat transfer coefficient was estimated as pressure increased to 10.3 MPa. The results demonstrate that hyperbaric aerodynamic levitation is a promising technique for containerless materials research at high gas pressures

Measurements of dense fuel hydrodynamics in the NIF burning plasma experiments using backscattered neutron spectroscopy

The hydrodynamics of the dense confining fuel shell is of great importance in defining the behaviour of the burning plasma and burn propagation regimes of inertial confinement fusion experiments. However, it is difficult to probe due to its low emissivity in comparison to the central fusion core. In this work, we utilise the backscattered neutron spectroscopy technique to directly measure the hydrodynamic conditions of the dense fuel during fusion burn. Experimental data is fit to obtain dense fuel velocities and apparent ion temperatures. Trends of these inferred parameters with yield and velocity of the burning plasma are used to investigate their dependence on alpha heating and low mode drive asymmetry. It is shown that the dense fuel layer has an increased outward radial velocity as yield increases showing burn has continued into re-expansion, a key signature of hotspot ignition. Comparison with analytic and simulation models show that the observed dense fuel parameters are displaying signatures of burn propagation into the dense fuel layer, including a rapid increase in dense fuel apparent ion temperature with neutron yield

Resonant nonlinear magneto-optical effects in atoms

In this article, we review the history, current status, physical mechanisms, experimental methods, and applications of nonlinear magneto-optical effects in atomic vapors. We begin by describing the pioneering work of Macaluso and Corbino over a century ago on linear magneto-optical effects (in which the properties of the medium do not depend on the light power) in the vicinity of atomic resonances, and contrast these effects with various nonlinear magneto-optical phenomena that have been studied both theoretically and experimentally since the late 1960s. In recent years, the field of nonlinear magneto-optics has experienced a revival of interest that has led to a number of developments, including the observation of ultra-narrow (1-Hz) magneto-optical resonances, applications in sensitive magnetometry, nonlinear magneto-optical tomography, and the possibility of a search for parity- and time-reversal-invariance violation in atoms.Comment: 51 pages, 23 figures, to appear in Rev. Mod. Phys. in Oct. 2002, Figure added, typos corrected, text edited for clarit

Probable Psittacosis Outbreak Linked to Wild Birds

Residence in the upper Blue Mountains, age of 50–64 years, direct contact with wild birds, and lawn mowing without a grass catcher were associated with psittacosis

The effect of massage on localized lumbar muscle fatigue

BACKGROUND: There is not enough evidence to support the efficacy of massage for muscle fatigue despite wide utilization of the modality in various clinical settings. This study investigated the influence of massage application on localized back muscle fatigue. METHODS: Twenty-nine healthy subjects participated in two experimental sessions (massage and rest conditions). On each test day, subjects were asked to lie in the prone position on a treatment table and perform sustained back extension for 90 seconds. Subjects then either received massage on the lumbar region or rested for a 5 minute duration, then repeated the back extension movement. The median frequency (MDF), mean power frequency (MNF), and root mean square (RMS) amplitude of electromyographic signals during the 90 second sustained lumbar muscle contraction were analyzed. The subjective feeling of fatigue was then evaluated using the Visual Analogue Scale (VAS). RESULTS: MDF and MNF significantly declined with time under all conditions. There was no significant difference in MDF, MNF or RMS value change between before and after massage, or between rest and massage conditions. There was a significant increase in fatigue VAS at the end of the 2(nd) back extension with rest condition. There was a significant difference in fatigue VAS change between massage and rest condition. CONCLUSIONS: A significant difference was observed between massage and rest condition on VAS for muscle fatigue. On EMG analysis, there were no significant differences to conclude that massage stimulation influenced the myoelectrical muscle fatigue, which is associated with metabolic and electrical changes

Psychosocial issues of women with type 1 diabetes transitioning to motherhood: a structured literature review

BACKGROUND: Life transitions often involve complex decisions, challenges and changes that affect diabetes management. Transition to motherhood is a major life event accompanied by increased risk that the pregnancy will lead to or accelerate existing diabetes-related complications, as well as risk of adverse pregnancy outcomes, all of which inevitably increase anxiety. The frequency of hyperglycaemia and hypoglycaemia often increases during pregnancy, which causes concern for the health and physical well-being of the mother and unborn child. This review aimed to examine the experiences of women with T1DM focusing on the pregnancy and postnatal phases of their transition to motherhood. METHODS: The structured literature review comprised a comprehensive search strategy identifying primary studies published in English between 1990-2012. Standard literature databases were searched along with the contents of diabetes-specific journals. Reference lists of included studies were checked. Search terms included: 'diabetes', 'type 1', 'pregnancy', 'motherhood', 'transition', 'social support', 'quality of life' and 'psychological well-being'. RESULT: Of 112 abstracts returned, 62 articles were reviewed in full-text, and 16 met the inclusion criteria. There was a high level of diversity among these studies but three common key themes were identified. They related to physical (maternal and fetal) well-being, psychological well-being and social environment. The results were synthesized narratively. CONCLUSION: Women with type 1 diabetes experience a variety of psychosocial issues in their transition to motherhood: increased levels of anxiety, diabetes-related distress, guilt, a sense of disconnectedness from health professionals, and a focus on medicalisation of pregnancy rather than the positive transition to motherhood. A trusting relationship with health professionals, sharing experiences with other women with diabetes, active social support, shared decision and responsibilities for diabetes management assisted the women to make a positive transition. Health professionals can promote a positive transition to motherhood by proactively supporting women with T1DM in informed decision-making, by facilitating communication within the healthcare team and co-ordinating care for women with type 1 diabetes transitioning to motherhood

Detecting ‘poachers’ with drones: Factors influencing the probability of detection with TIR and RGB imaging in miombo woodlands, Tanzania

Conservation biologists increasingly employ drones to reduce poaching of animals. However, there are no published studies on the probability of detecting poachers and the factors influencing detection. In an experimental setting with voluntary subjects, we evaluated the influence of various factors on poacher detection probability: camera (visual spectrum: RGB and thermal infrared: TIR), density of canopy cover, subject distance from the image centreline, subject contrast against the background, altitude of the drone and image analyst. We manually analysed the footage and marked all recorded subject detections. A multilevel model was used to analyse the TIR image data and a general linear model approach was used for the RGB image data. We found that the TIR camera had a higher detection probability than the RGB camera. Detection probability in TIR images was significantly influenced by canopy density, subject distance from the centreline and the analyst. Detection probability in RGB images was significantly influenced by canopy density, subject contrast against the background, altitude and the analyst. Overall, our findings indicate that TIR cameras improve human detection, particularly at cooler times of the day, but this is significantly hampered by thick vegetation cover. The effects of diminished detection with increased distance from the image centreline can be improved by increasing the overlap between images although this requires more flights over a specific area. Analyst experience also contributed to increased detection probability, but this might cease being a problem following the development of automated detection using machine learning