Comparison between measured turbine stage performance and the predicted performance using quasi-3D flow and boundary layer analyses

A method for calculating turbine stage performance is described. The usefulness of the method is demonstrated by comparing measured and predicted efficiencies for nine different stages. Comparisons are made over a range of turbine pressure ratios and rotor speeds. A quasi-3D flow analysis is used to account for complex passage geometries. Boundary layer analyses are done to account for losses due to friction. Empirical loss models are used to account for incidence, secondary flow, disc windage, and clearance losses

Elucidation of active sites for the reaction of ethanol on TiO2/Au(111)

Obtaining a molecular-level understanding of the reaction of alcohols with heterogeneous model catalysts is critical for improving industrial catalytic processes, such as the production of H2 from alcohols. Gold has been shown to be an excellent oxidation catalyst once oxygen is added to it. The use of reducible oxides provides a source of oxygen on Au(111) for the reaction of ethanol, which is easily regenerated in the presence of an oxygen background. In this work, ethanol operates as a probe molecule to investigate the role of Au(111), TiO2 nanoparticles, and TiO2/Auinterfacial surface sites on the catalytic properties of TiO2/Au(111). Ultrahigh vacuum temperature programmed desorption (TPD) studies with ethanol/Au(111) elucidate previously unreported adsorption sites for ethanol. Ethanol molecularly adsorbs to Au terrace sites, step edges, and undercoordinated kink sites with adsorption energies of -51.7, -55.8, and -65.1 kJ/mol, respectively. A TPD coverage study of ethanol on TiO2/Au(111) indicates ethanol undergoes dissociative adsorption to form H*(a) and CH3CH2O*(a) on the inverse model catalyst surface. The desorption temperature of low coverages of ethanol from TiO2/Au(111) (Tdes= ~235 K) is at an intermediate temperature between the desorption temperatures from bulk Au(111) and TiO2(110), indicating both Au and TiO2 play a role in the adsorption of ethanol. Both low-temperature adsorption and high-temperature reactions are studied and indicate that ethanol-derived products—such as acetaldehyde and ethylene—desorb from TiO2/Au(111) at ~500 K

The Relationship Between Insomnia, Sleep Continuity Disturbance, Sleep-related Daytime Dysfunction, Problem Endorsement, and Aging in a Community-based Sample

Although older adults experience greater difficulty initiating sleep, maintaining sleep, or waking up earlier than intended, they are less likely to report that they perceive this to be a problem. The discordance between sleep disorder symptoms and the reported perception that they are troubling is unusually prevalent among older adults. This may be problematic, in that individuals who do not perceive their sleep continuity disturbances (SCDs; difficulty falling asleep, staying asleep, or waking up earlier than intended) to be problems are less likely to seek treatment. Untreated SCD has been shown to be a risk factor for the development or exacerbation of multiple medical and psychiatric disorders such as cardiovascular disease, stroke, dementia, and depression. This study aimed to identify the relationship between age, SCD, sleep-related daytime dysfunction, and the perception that these symptoms are problematic. The study utilized a cross-sectional group comparison approach to assess for age differences in relation to SCD, sleep-related daytime dysfunction, and percent problem endorsement in an archival, community dataset comprised of individuals between 18 and 89 years of age, with sleep complaints. The results indicated that, as expected, SCD worsens with age (except sleep latency); sleep-related daytime dysfunction did not worsen with age except for concentration; and, contrary to expectation, problem endorsement increased with age (except for sleep latency). Findings illustrate the importance of comprehensive sleep assessments, preferably with the inclusion of the question: Is this a problem