Photoionization of the valence orbitals of OH

We report the results of studies of the photoionization cross sections and asymmetry parameters for the 3σ and 1π levels of OH, corresponding to the production of the A ^3Π, c ^1Π, a ^1Δ, b ^1Σ+, and X ^3Σ− molecular ions. The calculations employed multiplet‐specific Hartree–Fock potentials and numerical photoelectron continuum orbitals, obtained using the iterative Schwinger variational method. Noticeable nonstatistical behavior of the cross sections is seen, mainly for the 1π level, although deviations are not as pronounced as in other open‐shell systems. Comparison with fragmentary experimental data is encouraging, although synchrotron radiation studies are needed to fully assess the accuracy of the calculated cross sections

Shape-resonance-induced non-Franck–Condon effects in (2+1) resonance enhanced multiphoton ionization of the C 3Πg state of O2

We show that strong non-Franck–Condon effects observed in (2+1) resonance enhanced multiphoton ionization of the C 3Pig state of O2 are due to the ksigmau shape resonance previously observed in single-photon studies of diatomic molecules. Calculated vibrational branching ratios for the v=2,3 levels of the C 3Πg state are in reasonable agreement with experiment. Certain discrepancies remain in comparing theoretical results with the measured spectra, and possible electron-correlation effects which underly this are discussed

Studies related to the design of a magnetic suspension and balance system Interim technical report, Dec. 1964 - Jan. 1966

Magnetic suspension and balance system for use in hypersonic flow apparatu

A recurrence matrix method for the analysis of longitudinal and torsional vibrations in non-uniform multibranch beams with variable boundary conditions

An approximate method for calculating the longitudinal and torsional natural frequencies and associated modal data of a beamlike, variable cross section multibranch structure is presented. The procedure described is the numerical integration of the first order differential equations that characterize the beam element in longitudinal motion and that satisfy the appropriate boundary conditions

Active vibration isolator for flexible bodies Patent

Vibration control of flexible bodies in steady accelerating environmen

Improved active vibration isolator

Active vibration isolator simultaneously isolates a flexible structure or payload from disturbances, attenuates the response of a flexible structure to transient disturbances, and maintains the equilibrium position of the payload within predetermined limits over a wide range of steady loads and accelerators

Vibrational state dependence of ionic rotational branching ratios in resonance enhanced multiphoton ionization of CH

We show that rapid evolution of a Rydberg orbital with internuclear distance in a resonance enhanced multiphoton ionization (REMPI) process can have a profound influence on the production of molecular ions in alternative rotational states. This is illustrated by calculations of ionic rotational branching ratios for (2+1′) REMPI via the O11 (20.5) branch of the E′ ^2Σ^+(3pσ) Rydberg state of CH. The rotational propensity rule for ionization changes from ΔN=odd (ΔN=N_+−N_i) at lower vibrational excitation, as expected from the ΔN+l=odd selection rule, to ΔN=even at higher vibrational levels. This effect is expected to be quite general and should be most readily observable in diatomic hydrides

Radial fall of a test particle onto an evaporating black hole

A test particle falling into a classical black hole crosses the event horizon and ends up in the singularity within finite eigentime. In the `more realistic' case of a `classical' evaporating black hole, an observer falling onto a black hole observes a sudden evaporation of the hole. This illustrates the fact that the discussion of the classical process commonly found in the literature may become obsolete when the black hole has a finite lifetime. The situation is basically the same for more complex cases, e.g. where a particle collides with two merging black holes. It should be pointed out that the model used in this paper is mainly of academic interest, since the description of the physics near a black hole horizon still presents a difficult problem which is not yet fully understood, but our model provides a valuable possibility for students to enter the interesting field of black hole physics and to perform numerical calculations of their own which are not very involved from the computational point of view.Comment: 6 pages, 3 figures, LATE

Black lesbian identities, power and violence in public and private spaces

This study examined black South African lesbian’s lived experiences of power and violence through a reading of the lesbian body as a site through which social identities and power are produced, maintained, contested and reframed. The analytic gaze was cast inward on intimate relationships as well as outward on the social and community contexts. Forty black lesbian women who were or had been in intimate same-sex relationships participated in five focus group discussions and 22 depth interviews. Discourse analysis, edified by a feminist poststructuralist theoretical paradigm that advanced an intersectional analytical approach, revealed that participants assumed multiple and ambiguous gendered subject positions, and vacillated between positions of power and powerlessness in various contexts. The enactment of gendered and sexualised violence on the lesbian body within intimate lesbian relationships, as well as in public and social spaces that also marked politicised and racialised spaces, reflected tensions and contradictions that may be situated within the historical juxtapositioning of colonialism and democracy. While black lesbian women generally exercised high levels of self-surveillance in order to avoid culturally and socially endorsed raced and gendered practices that served to regulate and punish black lesbian sexuality; the lesbian body represented a powerful site of resistance in which gendered identities and sexualities were reconceptualised and renegotiated in more fluid ways within the current historical period in South Africa. Within this reframing, black lesbian identity represented and embodied a personal and a political statement of identity and resilience which troubled and contested citizenship in democratic South Africa. This study has foregrounded the importance of considering the interconnectedness of the public and private domains, and the intersections of history and contexts in the enactment and experience of power and violence in the lives of black lesbian women. It has important implications for research, programme design and policy