Solving the Coulomb scattering problem using the complex scaling method

Based on the work of Nuttall and Cohen [Phys. Rev. {\bf 188} (1969) 1542] and Resigno et al{} [Phys. Rev. A {\bf 55} (1997) 4253] we present a rigorous formalism for solving the scattering problem for long-range interactions without using exact asymptotic boundary conditions. The long-range interaction may contain both Coulomb and short-range potentials. The exterior complex scaling method, applied to a specially constructed inhomogeneous Schr\"odinger equation, transforms the scattering problem into a boundary problem with zero boundary conditions. The local and integral representations for the scattering amplitudes have been derived. The formalism is illustrated with numerical examples.Comment: 3 pages, 3 figure

Water outlet control mechanism for fuel cell system operation in variable gravity environments

A self-regulated water separator provides centrifugal separation of fuel cell product water from oxidant gas. The system uses the flow energy of the fuel cell's two-phase water and oxidant flow stream and a regulated ejector or other reactant circulation pump providing the two-phase fluid flow. The system further uses a means of controlling the water outlet flow rate away from the water separator that uses both the ejector's or reactant pump's supply pressure and a compressibility sensor to provide overall control of separated water flow either back to the separator or away from the separator

Behind the Mask of Morality: (E)urochristian Bioethics and the Colonial-Racial Discourse

The discipline of bioethics is insufficient and ineffective in addressing the persistent issues of racism and racial inequalities in healthcare. A minority of bioethicists are indeed attentive to issues such as implicit bias, structural racism, power inequalities, and the social determinants of health. Yet, these efforts do not consider the colonial-racial discourse -- that racism is an instrument of eurochristian colonialism, and bioethics is a product of that same colonial worldview. Exposing mainstream bioethicists to the work of anti-colonial scholars and activists would provide bioethicists a framework through which they would be better equipped to address issues of race through: 1) a deeper understanding of their complicity with colonialism, and 2) the importance of anti-colonial methods and approaches to ethical decision-making in healthcare. Three contemporary bioethics cases involving issues of race are examined including Jahi McMath and the diagnosis of brain death, the Havasupai diabetes research protocol, and the treatment of Latinx undocumented immigrants with end-stage renal disease. These cases serve as the focal point for 1) the extrication of eurochristian colonial themes within three foundational bioethics texts, and 2) the application of the knowledge and praxis of three anti-colonial scholars toward racially responsive case analyses and outcomes. I conclude that the combination of a robust self-examination of the discipline\u27s eurochristian worldview and the prioritization of a range of anti-colonial perspectives would serve bioethics more fully in the imagining of a racially conscious bioethics practice, scholarship, and policy that aims to reject colonial constructs and normalize difference

Mind the Gap : Tech-Based Dispute Resolution for Disputes in Global Supply Blockchains

Peer reviewedPostprin

Double K-shell photoionization of atomic beryllium

Double photoionization of the core 1s electrons in atomic beryllium is theoretically studied using a hybrid approach that combines orbital and grid-based representations of the Hamiltonian. The 1S ground state and 1P final state contain a double occupancy of the 2s valence shell in all configurations used to represent the correlated wave function. Triply differential cross sections are evaluated, with particular attention focused on a comparison of the effects of scattering the ejected electrons through the spherically symmetric valence shell with similar cross sections for helium, representing a purely two-electron target with an analogous initial-state configurationWork partially supported by the MICINN projects FIS2010-15127, ACI2008-0777, and CSD 2007-00010; the ERA-Chemistry project PIM2010EEC- 00751; European grants MC-ITN CORINF and MC-RG ATTOTREND; and the European COST Action CM0702. F.L.Y. acknowledges support from Extesp-MICINN Modalidad B. Work at the Lawrence Berkeley National Laboratory was performed under the auspices of the US DOE under Contract No. DE-AC02-05CH11231 and was supported by the US DOE Office of Basic Energy Sciences, Division of Chemical Science

Fully differential single-photon double ionization of neon and argon

Triply differential cross sections are calculated for one-photon double ionization of neon and argon at various photon energies and electron energy sharings by using a frozen-core treatment to represent the remaining electrons of the residual ion. Angular distributions agree well with all existing experimental data, showing that in spite of its simplicity the method can treat the double ionization of complex targets reliably. A comparison of the cross sections for helium, neon, and argon into the same final state symmetry at the same relative excess energies reveals a distinctive signature of the role of electron correlation in each targetThis work was accomplished with an allocation of computer time from Mare Nostrum BSC and NERSC and partially supported by the MICINN Projects No. FIS2010- 15127, No. ACI2008-0777, and No. CSD 2007-00010, the ERA-Chemistry Project No. PIM2010EEC-00751, the European grant MC-ITN CORINF, the European COST Action CM0702, and the Advanced Grant of the European Research Council No. XCHEM 290853. C.W.M. and T. N.R. acknowledge support from U.S. Department of Energy Office of Basic Energy Sciences, Division of Chemical Sciences Contract No. DE-AC02-05CH11231. F. L.Y. acknowledges a postdoc contract from MICIN

The Effects of Airflow and Constriction of the Vocal Tract in the Production of Aerosols in Speech

With the rise of infectious disease spread by airborne transmission such as SARS-CoV-2, there is a need to understand the role of speech aerosol in transmission. This study examined the role of the speech mechanism in the production of aerosols of five female participants. Particle counts were measured for sustained vowels /ɑ, i, ɛ, ə/ produced in modal register, falsetto register, vocal fry, whisper, loud, and with an h-onset. The presence of a super emitter altered results and necessitated analysis that included and excluded the super emitter. Our results consistently showed that amount of airflow through the speech mechanism contributes to the amount of particles released with whispering and loud voice producing the most, followed by modal register, falsetto register, h-onset, and lastly vocal fry. Tongue tension and vowel shape did not contribute to changes in particle generation as both tense, lax, open, and closed vowels produced high particle counts.</p

Anthropogenic effects on chronic stress and nest predation patterns in freshwater turtles

Human altered landscapes contribute to direct and indirect threats on wildlife populations. Chronically high stress, an indirect threat, has been associated with decreased fitness. I examined chronic stress in Midland Painted Turtles (Chrysemys picta marginata), Snapping Turtles (Chelydra serpentina), and Blanding's Turtles (Emydoidea blandingii) in areas with varying densities of anthropogenic structures in Muskoka,Ontario. Enzyme immunoassays were run, in partnership with Dr. Gabriela Mastromonaco (Toronto Zoo), on turtle claws to obtain concentrations of corticosterone (CORT). Most Snapping Turtles had above-minimum CORT, and male Midland Painted Turtles and Blanding's Turtles had relatively high CORT levels. Anthropogenic density did not seem to affect CORT levels, but more research needs to be done to understand the complex relationships. I also determined the rate and pattern of nest depredation, a direct threat, throughout egg incubation in areas of varying anthropogenic densities. Nest depredation occurred throughout egg incubation and relative nest mesopredator abundance did not differ among sites with varying anthropogenic densities. Contrary to some nest caging protocols, my findings suggest that nest cages should be kept on nests until the turtles hatch and priority should be given to caging nests in low road density areas to help increase population recruitment. Understanding indirect and direct threats to turtles can help inform mitigation strategies to improve their fitness.Master of Science (MSc) in Biolog