Electromagnetic waves in a Josephson junction in a thin film

We consider a one-dimensional Josephson junction in a superconducting film with the thickness that is much less than the London penetration depth. We treat an electromagnetic wave propagating along this tunnel contact. We show that the electrodynamics of a Josephson junction in a thin film is nonlocal if the wave length is less than the Pearl penetration depth. We find the integro-differential equation determining the phase difference between the two superconductors forming the tunnel contact. We use this equation to calculate the dispersion relation for an electromagnetic wave propagating along the Josephson junction. We find that the frequency of this wave is proportional to the square root of the wave vector if the wave length is less than the Pearl penetration depth.Comment: 12 pages, a figure is included as a uuencodeded postscript file, ReVTe

Framing and Immigration Through the Trump Era

For the last decade, undocumented or illegal immigration has been one of the most contested policy issues in the United States, with significant news attention on policies affecting the undocumented population, ranging from deportations to comprehensive immigration reform, the DREAM Act, and Deferred Action for Childhood Arrivals. Despite these prominent and multifaceted policy debates, scholarship on media framing and public opinion remain more focused on the portrayal of immigrants rather than policies affecting them. In general, we find that policy frames are far more consequential to public opinion than equivalency frames (variations in how news media describe unauthorized immigrants, either as illegal or undocumented ) or episodic frames (whether news articles are heavy on human-interest stories rather than policy facts and statistics). In addition, negative frames generally have stronger effects than positive frames, and these effects sometimes vary by partisanship and family migration history. Finally, the relative infrequency of powerful frames in news stories, like time spent living in the United States, provides opportunities for advocates to move public opinion on immigration policy. These findings have important implications for future battles over immigration policy in the United States, which show no signs of abating

Composite excitation of Josephson phase and spin waves in Josephson junctions with ferromagnetic insulator

Coupling of Josephson-phase and spin-waves is theoretically studied in a superconductor/ferromagnetic insulator/superconductor (S/FI/S) junction. Electromagnetic (EM) field inside the junction and the Josephson current coupled with spin-waves in FI are calculated by combining Maxwell and Landau-Lifshitz-Gilbert equations. In the S/FI/S junction, it is found that the current-voltage (I-V) characteristic shows two resonant peaks. Voltages at the resonant peaks are obtained as a function of the normal modes of EM field, which indicates a composite excitation of the EM field and spin-waves in the S/FI/S junction. We also examine another type of junction, in which a nonmagnetic insulator (I) is located at one of interfaces between S and FI. In such a S/I/FI/S junction, three resonant peaks appear in the I-V curve, since the Josephson-phase couples to the EM field in the I layer.Comment: 16 pages, 5 figure

Slice Stretching at the Event Horizon when Geodesically Slicing the Schwarzschild Spacetime with Excision

Slice-stretching effects are discussed as they arise at the event horizon when geodesically slicing the extended Schwarzschild black-hole spacetime while using singularity excision. In particular, for Novikov and isotropic spatial coordinates the outward movement of the event horizon (``slice sucking'') and the unbounded growth there of the radial metric component (``slice wrapping'') are analyzed. For the overall slice stretching, very similar late time behavior is found when comparing with maximal slicing. Thus, the intuitive argument that attributes slice stretching to singularity avoidance is incorrect.Comment: 5 pages, 2 figures, published version including minor amendments suggested by the refere

Exact boundary conditions in numerical relativity using multiple grids: scalar field tests

Cauchy-Characteristic Matching (CCM), the combination of a central 3+1 Cauchy code with an exterior characteristic code connected across a time-like interface, is a promising technique for the generation and extraction of gravitational waves. While it provides a tool for the exact specification of boundary conditions for the Cauchy evolution, it also allows to follow gravitational radiation all the way to infinity, where it is unambiguously defined. We present a new fourth order accurate finite difference CCM scheme for a first order reduction of the wave equation around a Schwarzschild black hole in axisymmetry. The matching at the interface between the Cauchy and the characteristic regions is done by transfering appropriate characteristic/null variables. Numerical experiments indicate that the algorithm is fourth order convergent. As an application we reproduce the expected late-time tail decay for the scalar field.Comment: 14 pages, 5 figures. Included changes suggested by referee

Additive Construction with Mobile Emplacement: Multifaceted Planetary Construction Materials Development

The National Aeronautics and Space Administration's Additive Construction with Mobile Emplacement (ACME) project is developing construction materials with which infrastructure elements, including habitats, will be additively constructed for planetary surface missions. These materials must meet requirements such as the ability to be produced from available in-situ resources to eliminate the cost of launching materials from Earth, the ability to be emplaced via three dimensional building techniques, the ability to resist aging in extreme environments including radiation and micrometeorite bombardment, and the ability to provide the necessary structural integrity for a given building. This paper reviews the constraints placed on such planetary construction materials and details the work of the ACME team in characterizing materials that could one day construct planetary surface structures on Mars or the Moon. Material compositions, compressive strength, and requirements for additive construction on planetary surfaces are discussed. Due to the multifunctional requirements of the material, an optimization is necessary to balance between the site-specific regolith composition, emplacement via additive construction techniques, and characteristics of the final structure

Children's daily travel to school in Johannesburg-Soweto, South Africa: geography and school choice in the Birth to Twenty cohort study

This paper has two aims: to explore approaches to the measurement of children’s daily travel to school in a context of limited geospatial data availability, and to provide data regarding school choice and distance travelled to school in Soweto-Johannesburg, South Africa. The paper makes use of data from the Birth to Twenty cohort study (n=1428) to explore three different approaches to estimating school choice and travel to school. Firstly, straight-line distance between home and school is calculated. Secondly, census geography is used to determine whether a child's home and school fall in the same area. Thirdly, distance data are used to determine whether a child attends the nearest school. Each of these approaches highlights a different aspect of mobility, and all provide valuable data. Overall, primary school aged children in Soweto-Johannesburg are shown to be travelling substantial distances to school on a daily basis. Over a third travel more than 3km, one-way, to school, 60% attend schools outside of the suburb in which they live, and only 18% attend their nearest school. These data provide evidence for high levels of school choice in Johannesburg-Soweto, and that families and children are making substantial investments in pursuit of high quality educational opportunities. Additionally, these data suggest that two patterns of school choice are evident: one pattern involving travel of substantial distances and requiring a higher level of financial investment, and a second pattern, involving choice between more local schools, requiring less travel and a more limited financial investment

Beyond Prejudice as Simple Antipathy: Hostile and Benevolent Sexism Across Cultures

The authors argue that complementary hostile and benevolent componen:s of sexism exist ac ro.ss cultures. Male dominance creates hostile sexism (HS). but men's dependence on women fosters benevolent sexism (BS)-subjectively positive attitudes that put women on a pedestal but reinforce their subordination. Research with 15,000 men and women in 19 nations showed that (a) HS and BS are coherenl constructs th at correlate positively across nations, but (b) HS predicts the ascription of negative and BS the ascription of positive traits to women, (c) relative to men, women are more likely to reject HS than BS. especially when overall levels of sexism in a culture are high, and (d) national averages on BS and HS predict gender inequal ity across nations. These results challenge prevailing notions of prejudice as an antipathy in that BS (an affectionate, patronizing ideology) reflects inequality and is a cross-culturally pervasive complement to HS

Incentives as connectors : insights into a breastfeeding incentive intervention in a disadvantaged area of North-West England

PMID: 22458841 [PubMed - indexed for MEDLINE] PMCID: PMC3414740 Free PMC ArticlePeer reviewedPublisher PD

Assessment and treatment of distorted schemas in sexual offenders

The aim of this review is to examine the literature related to the assessment and treatment of sex offenders’ distorted schemas. Where appropriate, the review draws upon current insights from the field of social cognition to aid in the critical evaluation of the findings. First, the review considers the various different methodologies for assessing distorted schemas, discussing their strengths and limitations. Second, the review examines the work related to the treatment of sex offenders’ schemas. Suggestions for future research, and the implications for clinical practice, are highlighted in the article