Confronting the Concept of Intersectionality: The Legacy of Audre Lorde and Contemporary Feminist Organizations

Audre Lorde was one of many women to criticize second wave feminism for overlooking issues of intersectionality. This paper examines the ways in which Lorde introduced intersectionality into feminist discourse and how feminist organizations embrace this concept today. Five organizations are examined (National Organization for Women, Grand Valley State University Women’s Center, Ms. Foundation, Third Wave Foundation, and Guerilla Girls) by interviewing representatives and/or evaluating websites to assess organizational mission, vision, values and practices. Analyses reveal that all five organizations have specific policy statements addressing intersectionality. This research can conclusively say that intersectionality is at least considered by all of the organizations. Determining whether or not the current intervention strategies are effective for women experiencing overlapping oppressions is beyond the scope of this study. The different rhetoric used by each organization to address the intersectional issue, however, suggests that intersectionality is “applied” or put into practice differently by different organizations

Mathematical models of continuous flow electrophoresis: Electrophoresis technology

Two aspects of continuous flow electrophoresis were studied: (1) the structure of the flow field in continuous flow devices; and (2) the electrokinetic properties of suspended particles relevant to electrophoretic separations. Mathematical models were developed to describe flow structure and stability, with particular emphasis on effects due to buoyancy. To describe the fractionation of an arbitrary particulate sample by continuous flow electrophoresis, a general mathematical model was constructed. In this model, chamber dimensions, field strength, buffer composition, and other design variables can be altered at will to study their effects on resolution and throughput. All these mathematical models were implemented on a digital computer and the codes are available for general use. Experimental and theoretical work with particulate samples probed how particle mobility is related to buffer composition. It was found that ions on the surface of small particles are mobile, contrary to the widely accepted view. This influences particle mobility and suspension conductivity. A novel technique was used to measure the mobility of particles in concentrated suspensions

A spaceship with a thruster - one body, one force

A spaceship with one thruster producing a constant magnitude force is analyzed for various initial conditions. This elementary problem, with one object acted upon by one force, has value as a challenge to one's physical intuition and in demonstrating the benefits and limitations of dimensional analysis. In addition, the problem can serve to introduce a student to special functions, provide a mechanical model for Fresnel integrals and the associated Cornu spiral, or be used as an example in a numerical methods course. The problem has some interesting and perhaps unexpected features.Comment: 8 pages, 12 figures. Submitted to the American Journal of Physics. After it is published, it will be found at http://scitation.aip.org/aj

Supersymmetric Flavor-Changing Sum Rules as a Tool for b -> s gamma

The search for supersymmetry (SUSY) and other classes of new physics will be tackled on two fronts, with high energy, direct detection machines, and in high precision experiments searching for indirect signatures. While each of these methods has its own strengths, even more can be gained by finding ways to combine their results. In this paper, we examine one way of bridging these two types of experiments by calculating sum rules which link physical squark masses to the flavor-violating squark mixings. These sum rules are calculated for minimally flavor-violating SUSY theories at both high and low tan(beta). We also explore how the sum rules could help to disentangle the relative strengths of different SUSY contributions to b -> s gamma, a favored channel for indirect searches of new physics. Along the way, we show that the gluino contributions to b -> s gamma can be very sizable at large tan(beta).Comment: 27 pages, 3 figure

Efficient placement of structural dynamics sensors on the space station

System identification of the space station dynamic model will require flight data from a finite number of judiciously placed sensors on it. The placement of structural dynamics sensors on the space station is a particularly challenging problem because the station will not be deployed in a single mission. Given that the build-up sequence and the final configuration for the space station are currently undetermined, a procedure for sensor placement was developed using the assembly flights 1 to 7 of the rephased dual keel space station as an example. The procedure presented approaches the problem of placing the sensors from an engineering, as opposed to a mathematical, point of view. In addition to locating a finite number of sensors, the procedure addresses the issues of unobserved structural modes, dominant structural modes, and the trade-offs involved in sensor placement for space station. This procedure for sensor placement will be applied to revised, and potentially more detailed, finite element models of the space station configuration and assembly sequence

Resolution of a paradox: Hummingbird flight at high elevation does not come without a cost

Flight at high elevation is energetically demanding because of parallel reductions in air density and oxygen availability. The hovering flight of hummingbirds is one of the most energetically expensive forms of animal locomotion, but hummingbirds are nonetheless abundant at high elevations throughout the Americas. Two mechanisms enhance aerodynamic performance in high-elevation hummingbirds: increase in wing size and wing stroke amplitude during hovering. How do these changes in morphology, kinematics, and physical properties of air combine to influence the aerodynamic power requirements of flight across elevations? Here, we present data on the flight performance of 43 Andean hummingbird species as well as a 76-taxon multilocus molecular phylogeny that served as the historical framework for comparative analyses. Along a 4,000-m elevational transect, hummingbird body mass increased systematically, placing further aerodynamic demands on high-elevation taxa. However, we found that the minimum power requirements for hovering flight remain constant with respect to elevation because hummingbirds compensate sufficiently through increases in wing size and stroke amplitude. Thus, high-elevation hummingbirds are not limited in their capacity for hovering flight despite the challenges imposed by hypobaric environments. Other flight modes including vertical ascent and fast forward flight are more mechanically and energetically demanding, and we accordingly also tested for the maximum power available to hummingbirds by using a load-lifting assay. In contrast to hovering, excess power availability decreased substantially across elevations, thereby reducing the biomechanical potential for more complex flight such as competitive and escape maneuvers

Bohr's 1913 molecular model revisited

It is generally believed that the old quantum theory, as presented by Niels Bohr in 1913, fails when applied to few electron systems, such as the H2 molecule. Here we find new solutions within the Bohr theory that describe the potential energy curve for the lowest singlet and triplet states of H2 about as well as the early wave mechanical treatment of Heitler and London. We also develop a new interpolation scheme which substantially improves the agreement with the exact ground state potential curve of H2 and provides a good description of more complicated molecules such as LiH, Li2, BeH and He2.Comment: 6 pages, 9 figure

Modelling the spring ozone maximum and the interhemispheric asymmetry in the remote marine boundary layer 1. Comparison with surface and ozonesonde measurements

Here we report a modelling study of the spring ozone maximum and its interhemispheric asymmetry in the remote marine boundary layer (MBL). The modelled results are examined at the surface and on a series of time-height cross sections at several locations spread over the Atlantic, the Indian, and the Pacific Oceans. Comparison of model with surface measurements at remote MBL stations indicate a close agreement. The most striking feature of the hemispheric spring ozone maximum in the MBL can be most easily identified at the NH sites of Westman Island, Bermuda, and Mauna Loa, and at the SH site of Samoa. Modelled ozone vertical distributions in the troposphere are compared with ozone profiles. For the Atlantic and the Indian sites, the model generally produces a hemispheric spring ozone maximum close to those of the measurements. The model also produces a spring ozone maximum in the northeastern and tropical north Pacific close to those measurements, and at sites in the NH high latitudes. The good agreement between model and measurements indicate that the model can reproduce the proposed mechanisms responsible for producing the spring ozone maximum in these regions of the MBL, lending confidence in the use of the model to investigate MBL ozone chemistry (see part 2 and part 3). The spring ozone maximum in the tropical central south Pacific and eastern equatorial Pacific are less well reproduced by the model, indicating that both the transport of $O_3$ precursors from biomass burning emissions taking place in southeastern Asia, Australia, Oceania, southern Africa, and South America are not well represented in the model in these regions. Overall, the model produces a better simulation at sites where the stratosphere and biomass burning emissions are the major contributors.Comment: 24 pages, 8 figure

Correlation patterns from massive phonons in 1+1 dimensional acoustic black holes: A toy model

Transverse excitations in analogue black holes induce a mass like term in the longitudinal mode equation. With a simple toy model we show that correlation functions display a rather rich structure characterized by groups of parallel peaks. For the most part the structure is completely different from that found in the massless case.Comment: 40 pages, 13 figures. Minor changes and corrections Phys. Rev. D versio

Efficient sorting of Bessel beams

We demonstrate the efficient sorter of Bessel beams separating both the azimuthal and radial components. This is based upon the recently reported transformation of angular to transverse momentum states. We separately identify over forty azimuthal and radial components, with a radial spacing of 1588 m<sup>−1</sup>, and outline how the device could be used to identify the two spatial dimensions simultaneously