Asymmetric inlet flow in axial turbomachines

May 1959Includes bibliographical references (leaves 53-55)A modified actuator disc analysis is made which, through an improved prediction of the blade forces, attempts to give closer correspondence with experiment than the previous theory. The fluid is assumed inviscid and incompressible. Perturbations to the two-dimensional flow through an isolated blade row are considered. The steady flow equations of motion and continuity are linearized. According to experiments conducted on an isolated compressor rotor, the present theory offers an improvement, compared to previous theory, in the prediction of distortion attenuation, effects of flow rate, and effects of varying chord/spacing ratio.Under the Sponsorship of: General Electric Company, Westinghouse Electric Corporation and Allison Division of General Motors Corporatio

Largest M Dwarf Flares from ASAS-SN

The All-sky Automated Survey for Supernovae (ASAS-SN) is the only project in existence to scan the entire sky in optical light approximately every day, reaching a depth of g ~ 18 mag. Over the course of its first 4 yr of transient alerts (2013–2016), ASAS-SN observed 53 events classified as likely M dwarf flares. We present follow-up photometry and spectroscopy of all 53 candidates, confirming flare events on 47 M dwarfs, one K dwarf, and one L dwarf. The remaining four objects include a previously identified T Tauri star, a young star with outbursts, and two objects too faint to confirm. A detailed examination of the 49 flare star light curves revealed an additional six flares on five stars, resulting in a total of 55 flares on 49 objects ranging in V-band contrast from ΔV = −1 to −10.2 mag. Using an empirical flare model to estimate the unobserved portions of the flare light curve, we obtain lower limits on the V-band energy emitted during each flare, spanning log(E_V/erg) = 32–35, which are among the most energetic flares detected on M dwarfs. The ASAS-SN M dwarf flare stars show a higher fraction of Hα emission, as well as stronger Hα emission, compared to M dwarfs selected without reference to activity, consistent with belonging to a population of more magnetically active stars. We also examined the distribution of tangential velocities, finding that the ASAS-SN flaring M dwarfs are likely to be members of the thin disk and are neither particularly young nor old

The federal government commissioner for patient issues in Germany: initial analysis of the user inquiries

BACKGROUND: The political objective in many countries worldwide is to give better consideration to the interests of patients within the health system. The establishment of a federal government commissioner for the issues of patients in the health system in Germany in 2004 is part of these endeavours. The structure and field of activities of this institution has been unique so far. This study investigates for the first time the inquiries the commissioner receives from the public. METHODS: A 33% sampling (n = 850) of the written inquiries (correspondence and e-mails) addressed to the commissioner in the first six months of the year 2005 (n = 2580) was investigated. In a procedure comprising combined qualitative and quantitative levels, the material was thematically encoded and the inquiries allocated to the resulting categories (multiple nominations). The results are presented in descriptive form and investigated especially with respect to sex and age-specific differences. The interdependences between the categorized criteria are analysed. RESULTS: The inquirers are equally spread out amongst the sexes (49% women, 51% men). Older persons outweigh the younger (69% over 60 years). In most cases the issues take the form of claims (72%, n = 609). In every fifth inquiry (n = 168) the personal financial burden for health services is considered as being too high; about equally high (n = 159) is the proportion of persons who criticize the communication with health professionals, especially hospitals and doctors' surgeries. Every third who mentions a medical practice uses terms such as "uncertainty" and "anxiety". It is conspicuous that men more often than women write that they feel unfairly treated in the health system (62% vs. 38%, p < 0.05). CONCLUSION: Predominantly older persons seek the assistance of the federal government commissioner for patient issues. Considerable uncertainty and anxiety with respect to services and charges within the system of the German health insurances become evident. It is not possible from the data to draw conclusions concerning the impact of the commissioner's work on the health system. Nor do we gain any knowledge about the usefulness of the service for the individual. Therefore, evaluation of the political impact and the user satisfaction should follow

Reducing Legionella Colonization of Water Systems with Monochloramine

Monochloramine reduced colonization in building hot water systems

Largest M Dwarf Flares from ASAS-SN

The All-sky Automated Survey for Supernovae (ASAS-SN) is the only project in existence to scan the entire sky in optical light approximately every day, reaching a depth of g ~ 18 mag. Over the course of its first 4 yr of transient alerts (2013–2016), ASAS-SN observed 53 events classified as likely M dwarf flares. We present follow-up photometry and spectroscopy of all 53 candidates, confirming flare events on 47 M dwarfs, one K dwarf, and one L dwarf. The remaining four objects include a previously identified T Tauri star, a young star with outbursts, and two objects too faint to confirm. A detailed examination of the 49 flare star light curves revealed an additional six flares on five stars, resulting in a total of 55 flares on 49 objects ranging in V-band contrast from ΔV = −1 to −10.2 mag. Using an empirical flare model to estimate the unobserved portions of the flare light curve, we obtain lower limits on the V-band energy emitted during each flare, spanning log(E_V/erg) = 32–35, which are among the most energetic flares detected on M dwarfs. The ASAS-SN M dwarf flare stars show a higher fraction of Hα emission, as well as stronger Hα emission, compared to M dwarfs selected without reference to activity, consistent with belonging to a population of more magnetically active stars. We also examined the distribution of tangential velocities, finding that the ASAS-SN flaring M dwarfs are likely to be members of the thin disk and are neither particularly young nor old

Technology roadmap for cold-atoms based quantum inertial sensor in space

Recent developments in quantum technology have resulted in a new generation of sensors for measuring inertial quantities, such as acceleration and rotation. These sensors can exhibit unprecedented sensitivity and accuracy when operated in space, where the free-fall interrogation time can be extended at will and where the environment noise is minimal. European laboratories have played a leading role in this field by developing concepts and tools to operate these quantum sensors in relevant environment, such as parabolic flights, free-fall towers, or sounding rockets. With the recent achievement of Bose-Einstein condensation on the International Space Station, the challenge is now to reach a technology readiness level sufficiently high at both component and system levels to provide "off the shelf"payload for future generations of space missions in geodesy or fundamental physics. In this roadmap, we provide an extensive review on the status of all common parts, needs, and subsystems for the application of atom-based interferometers in space, in order to push for the development of generic technology components

Mapping the internal recognition surface of an octanuclear coordination cage using guest libraries

Size and shape criteria for guest binding inside the cavity of an octanuclear cubic coordination cage in water have been established using a new fluorescence displacement assay to quantify guest binding. For aliphatic cyclic ketones of increasing size (from C5 to C11), there is a linear relationship between ΔG for guest binding and the guest’s surface area: the change in ΔG for binding is 0.3 kJ mol–1 Å–2, corresponding to 5 kJ mol–1 for each additional CH2 group in the guest, in good agreement with expectations based on hydrophobic desolvation. The highest association constant is K = 1.2 × 106 M–1 for cycloundecanone, whose volume is approximately 50% of the cavity volume; for larger C12 and C13 cyclic ketones, the association constant progressively decreases as the guests become too large. For a series of C10 aliphatic ketones differing in shape but not size, ΔG for guest binding showed no correlation with surface area. These guests are close to the volume limit of the cavity (cf. Rebek’s 55% rule), so the association constant is sensitive to shape complementarity, with small changes in guest structure resulting in large changes in binding affinity. The most flexible members of this series (linear aliphatic ketones) did not bind, whereas the more preorganized cyclic ketones all have association constants of 104–105 M–1. A crystal structure of the cage·cycloundecanone complex shows that the guest carbonyl oxygen is directed into a binding pocket defined by a convergent set of CH groups, which act as weak hydrogen-bond donors, and also shows close contacts between the exterior surface of the disc-shaped guest and the interior surface of the pseudospherical cage cavity despite the slight mismatch in shape

A Critical Review of Biomarkers Used for Monitoring Human Exposure to Lead: Advantages, Limitations, and Future Needs

Lead concentration in whole blood (BPb) is the primary biomarker used to monitor exposure to this metallic element. The U.S. Centers for Disease Control and Prevention and the World Health Organization define a BPb of 10 μg/dL (0.48 μmol/L) as the threshold of concern in young children. However, recent studies have reported the possibility of adverse health effects, including intellectual impairment in young children, at BPb levels < 10 μg/dL, suggesting that there is no safe level of exposure. It appears impossible to differentiate between low-level chronic Pb exposure and a high-level short Pb exposure based on a single BPb measurement; therefore, serial BPb measurements offer a better estimation of possible health outcomes. The difficulty in assessing the exact nature of Pb exposure is dependent not so much on problems with current analytical methodologies, but rather on the complex toxicokinetics of Pb within various body compartments (i.e., cycling of Pb between bone, blood, and soft tissues). If we are to differentiate more effectively between Pb stored in the body for years and Pb from recent exposure, information on other biomarkers of exposure may be needed. None of the current biomarkers of internal Pb dose have yet been accepted by the scientific community as a reliable substitute for a BPb measurement. This review focuses on the limitations of biomarkers of Pb exposure and the need to improve the accuracy of their measurement. We present here only the traditional analytical protocols in current use, and we attempt to assess the influence of confounding variables on BPb levels. Finally, we discuss the interpretation of BPb data with respect to both external and endogenous Pb exposure, past or recent exposure, as well as the significance of Pb determinations in human specimens including hair, nails, saliva, bone, blood (plasma, whole blood), urine, feces, and exfoliated teeth