Optimization of a Langmuir-Taylor detector for lithium

This paper describes the construction and optimization of a Langmuir-Taylor detector for lithium, using a rhenium ribbon. The absolute detection probability of this very sensitive detector is measured and the dependence of this probability with oxygen pressure and surface temperature is studied. Sources of background signal and their minimization are also discussed in details. And a comparison between our data concerning the response time of the detector and literature values is given. A theoretical analysis has been made: this analysis supports the validity of the Saha-Langmuir law to relate the ionization probability to the work function. Finally, the rapid variations of the work function with oxygen pressure and temperature are explained by a chemical equilibrium model.Comment: 11 pages, 7 figures, to appear in Rev. Sci. Instru

Digitalization and the Anthropocene

Great claims have been made about the benefits of dematerialization in a digital service economy. However, digitalization has historically increased environmental impacts at local and planetary scales, affecting labor markets, resource use, governance, and power relationships. Here we study the past, present, and future of digitalization through the lens of three interdependent elements of the Anthropocene: (a) planetary boundaries and stability, (b) equity within and between countries, and (c) human agency and governance, mediated via (i) increasing resource efficiency, (ii) accelerating consumption and scale effects, (iii) expanding political and economic control, and (iv) deteriorating social cohesion. While direct environmental impacts matter, the indirect and systemic effects of digitalization are more profoundly reshaping the relationship between humans, technosphere and planet. We develop three scenarios: planetary instability, green but inhumane, and deliberate for the good. We conclude with identifying leverage points that shift human–digital–Earth interactions toward sustainability

Chemisorbed Oxygen at Pt(111): a DFT Study of Structural and Electronic Surface Properties

Simulations based on density functional theory are used to study the electronic and electrostatic properties of a Pt(111) surface covered by a layer of chemisorbed atomic oxygen. The impact of the oxygen surface coverage and orientationally ordered interfacial water layers is explored. The oxygen adsorption energy decreases as a function of oxygen coverage due to the lateral adsorbate repulsion. The surficial dipole moment density induced by the layer of chemisorbed oxygen causes a positive shift of the work function. In simulations with interfacial water layers, ordering and orientation of water molecules strongly affect the work function. It is found that the surficial dipole moment density and charge density are roughly linearly dependent on the oxygen surface coverage. Moreover, we found that water layers exert only a small impact on the surface charging behavior of the surface

Künstliche Intelligenz und Klimawandel

KÜNSTLICHE INTELLIGENZ UND KLIMAWANDEL Künstliche Intelligenz und Klimawandel / Kaack, Lynn H. (CC BY-NC-SA) ( -

Detecting dementia among older, ethnically diverse residents of rural subsidized housing

•Rural, ethnically diverse residents face at least twice the dementia risk than urban residents.•Home-based cognitive screening and follow-up by AGNPs in rural settings was a successful approach.•Rural providers welcomed AGNP dementia-specific evaluations when discussing patient memory loss.•Hartford institute of geriatric nursing offers resources regarding dementia diagnosis and treatment.•Policy changes supporting AGNP rural home visits for dementia detection can improve health outcomes. Rural, ethnically diverse residents face at least twice the risk of Alzheimer's disease than urban residents. Chronic diseases such as diabetes and hypertension which increase dementia risk are more prevalent in rural areas with less access to specialty providers. A home-based approach for increasing dementia detection and treatment rates was tested among rural residents of government-assisted independent living facilities (N = 139; 78% non-White, and 70% with health literacy below 5th grade). Of 28 residents identified at risk during cognitive screening, 25 agreed to further in-depth assessment by adult gerontological nurse practitioners (AGNP). Fifteen of 25 (60%) completing consequent primary provider referrals were diagnosed with dementia and receiving new care (statistically significant; [χ2(1) = 76.67, p < .001, Phi = 0.743]). Home-based dementia management through a community engagement approach can help to meet the Healthy People 2030 goals of earlier detection and treatment and reduce the length of costly institutionalizations