Morphology of Graphene on SiC(000-1) Surfaces

Graphene is formed on SiC(000-1) surfaces (the so-called C-face of the crystal) by annealing in vacuum, with the resulting films characterized by atomic force microscopy, Auger electron spectroscopy, scanning Auger microscopy and Raman spectroscopy. Morphology of these films is compared with the graphene films grown on SiC(0001) surfaces (the Si-face). Graphene forms a terraced morphology on the C-face, whereas it forms with a flatter morphology on the Si-face. It is argued that this difference occurs because of differing interface structures in the two cases. For certain SiC wafers, nanocrystalline graphite is found to form on top of the graphene.Comment: Submitted to Applied Physics Letters; 9 pages, 3 figures; corrected the stated location of Raman G line for NCG spectrum, to 1596 cm^-

An Examination of Disgust, its Measures, and Gender Differences in the Experience of Disgust Sensitivity

The emotion of disgust is understudied. It has been implicated in various forms of psychopathology, but its overall influence remains unclear. New and improved methods and constructs are required if we are to better understand the relationship of disgust in attitude formation and psychological functioning. This study was an investigation of a measure referred to herein as the Disgust Propensity and Sensitivity Evolutionary Scale (DPSES). A total of 655 participants were recruited from a private university in the southeastern United States to complete a pencil -and-paper version of the measure in exchange for course credit. Exploratory factor analysis revealed an adequate five-factor structure that was further evaluated and supported through confirmatory factor analysis. The five-factor structure of the DPSES was determined to assess properties of disgust propensity, disgust sensitivity, sexual, moral, and pathogen disgust. Women\u27s scores were significantly higher than males\u27 across all subscales (Cohen\u27s d = 0.59 for disgust propensity, d = 0.62 for disgust sensitivity, d = 1.73 for sexual disgust, d = 0.37 for moral disgust, and d = 0.70 for pathogen disgust). Women are repeatedly demonstrated to have stronger reactions to disgust than men, most particularly in relation to sexual associations. A better overall understanding of reactions, gender differences, and ways that maladaptive responses to disgust influence various psychological disorders and dysfunctions increases the potential for advancements in corresponding diagnostic and treatment strategies

Variability and long-term changes in tropical cold-point temperature and water vapor

The tropical tropopause layer (TTL) is the main gateway for air transiting from the troposphere to the stratosphere and therefore impacts the chemical composition of the stratosphere. In particular, the cold-point tropopause, where air parcels encounter their final dehydration, effectively controls the water vapor content of the lower stratosphere. Given the important role of stratospheric water vapor for the global energy budget, it is crucial to understand the long-term changes in cold-point temperature and their impact on water vapor trends. Our study uses Global Navigation Satellite System – Radio Occultation (GNSS-RO) data to show that there has been no overall cooling trend of the TTL over the past 2 decades, in contrast to observations prior to 2000. Instead, the cold point is warming, with the strongest trends of up to 0.7 K per decade during boreal winter and spring. The cold-point warming shows longitudinal asymmetries, with the smallest warming over the central Pacific and the largest warming over the Atlantic. These asymmetries are anticorrelated with patterns of tropospheric temperature trends, and regions of strongest cold-point warming are found to show slight cooling trends in the upper troposphere. Overall, the here-identified warming of the cold point is consistent with model predictions under global climate change, which attribute the warming trends to radiative effects. The seasonal signals and zonal asymmetries of the cold-point temperature and height trends might be related to dynamical responses to enhanced upper-tropospheric heating, changing convection, or trends in the stratospheric circulation. Water vapor observations in the TTL show mostly positive trends consistent with cold-point warming for 2004–2021. We find a decrease in the amplitude of the cold-point temperature seasonal cycle by ∼ 7 % driving a reduction in the seasonal cycle in 100 hPa water vapor by 5 %–6 %. Our analysis shows that this reduction in the seasonal cycle is transported upwards together with the seasonal anomalies and has reduced the amplitude of the well-known tape recorder over the last 2 decades.</p