2,846 research outputs found

    Labor in the New Urban Battlegrounds: Local Solidarity in a Global Economy

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    [Excerpt] Labor in the New Urban Battlegrounds is an energizing, optimistic book. By using the contemporary metropolis as a comparative laboratory to see what contexts and strategies contribute best to labor revitalization, Lowell Turner, Daniel Cornfield, and their collaborators generate a fresh sense of positive possibilities for labor and new insights as to how creative actors can best take advantage of those possibilities. Energizing optimism should not be confused with seeing things through rose-colored glasses. The book fully acknowledges the odds against labor revitalization and the structural obstacles to a more equitable society. Optimism is generated by pairing obstacles with possibilities, often brought to light by another city in which similar obstacles have been overcome with innovative strategies. This book builds on a new tradition of recent analyses of U.S. labor that compellingly contests previous premature obituaries of the labor movement while making a distinctive contribution. Its power is rooted in the comparative metropolis analytical theme and the editors\u27 skill in bringing a diverse baker\u27s dozen of substantive studies to bear on it. The individual chapters are empirically diverse, complementing a gamut of metropolitan areas in the United States with comparative cases from Europe. They employ varied methodological approaches to look at the social infrastructure and strategic choices that underlie urban successes and failures. Many chapters are in-depth case studies of individual cities, while others (e.g., Greer, Byrd, and Fleron; Hauptmeier and Turner) are paired comparisons. Still others (Applegate; Luce; Reynolds) draw their evidence from larger numbers of cities. One (Sellers) employs an ingenious analysis of cross-national data to draw inferences about differences in urban strategic possibilities. The result is much more powerful analytically than it would have been had the editors collected thirteen metropolitan case studies and then tried to figure out their comparative implications. Empirical range and methodological diversity augment the power of the volume, but the overarching focus on comparative metropolitan analysis is what gives the book its distinctive analytical punch. Even though a variety of organizations and social actors populate the stageā€”campaigns, nongovernmental organizations, individual unions, and ethnic communitiesā€”defining the urban area as the stage on which the dramas occur was a critical decision. From this decision flows the book\u27s special contribution to refocusing contemporary labor debates

    Perturbative Theoretical Model of Electronic Transient Circular Dichroism Spectroscopy of Molecular Aggregates

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    A chiral analog of transient absorption spectroscopy, transient circular dichroism (TCD) spectroscopy is an emerging time-resolved method. Both spectroscopic methods can probe the electronic transitions of a sample, and TCD is additionally sensitive to the dynamic aspects of chirality, such as those induced by molecular excitons. Here, we develop a theoretical description of TCD for electronic multi-level models in which the pump pulse is linearly polarized and probe pulse is alternately left- and right-circularly polarized. We derive effective response functions analogous to those often used to describe other four-wave mixing methods and then simulate and analyze TCD spectra for three representative multi-level electronic model systems. We elaborate on the presence and detection of the spectral signatures of electronic coherences

    Conformal GaP layers on Si wire arrays for solar energy applications

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    We report conformal, epitaxial growth of GaP layers on arrays of Si microwires. Silicon wires grown using chlorosilane chemical vapor deposition were coated with GaP grown by metal-organic chemical vapor deposition. The crystalline quality of conformal, epitaxial GaP/Si wire arrays was assessed by transmission electron microscopy and x-ray diffraction. Hall measurements and photoluminescence show p- and n-type doping with high electron mobility and bright optical emission. GaP pn homojunction diodes on planar reference samples show photovoltaic response with an open circuit voltage of 660 mV

    10 Āµm minority-carrier diffusion lengths in Si wires synthesized by Cu-catalyzed vapor-liquid-solid growth

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    The effective electron minority-carrier diffusion length, L_(n,eff), for 2.0 Āµm diameter Si wires that were synthesized by Cu-catalyzed vapor-liquid-solid growth was measured by scanning photocurrent microscopy. In dark, ambient conditions, L_(n,eff) was limited by surface recombination to a value of ā‰¤ 0.7 Āµm. However, a value of L_(n,eff) = 10.5Ā±1 Āµm was measured under broad-area illumination in low-level injection. The relatively long minority-carrier diffusion length observed under illumination is consistent with an increased surface passivation resulting from filling of the surface states of the Si wires by photogenerated carriers. These relatively large L_(n,eff) values have important implications for the design of high-efficiency, radial-junction photovoltaic cells from arrays of Si wires synthesized by metal-catalyzed growth processes

    Prioritising neonatal medicines research: UK Medicines for Children Research Network scoping survey

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    BACKGROUND: The dosing regimen and indications for many medicines in current use in neonatology are not well defined. There is a need to prioritise research in this area, but currently there is little information about which drugs are used in UK neonatal units and the research needs in this area as perceived by UK neonatologists. METHODS: The Neonatal Clinical Studies Group (CSG) of the Medicines for Children Research Network (MCRN) undertook a 2 week prospective scoping survey study to establish which medicines are used in UK neonatal units; how many babies are receiving them; and what clinicians (and other health professionals) believe are important issues for future research. RESULTS: 49 out of 116 units responded to at least one element of the survey (42%). 37 units reported the number of neonates who received medicines over a 2 week period. A total of 3924 medicine-patient pairs were reported with 119 different medicines. 70% of medicine-patient pairs involved medicines that were missing either a license or dose for either term or preterm neonates. 4.3% of medicine-patient pairs involved medicines that were missing both license and dose for any neonate. The most common therapeutic gap in need of additional research identified by UK neonatologists was chronic lung disease (21 responding units), followed by patent ductus arteriosus and vitamin supplements (11 responding units for both) CONCLUSION: The research agenda for neonatal medicines can be informed by knowledge of current medicine use and the collective views of the neonatal community

    Perceptions of the intergroup structure and anti-Asian prejudice amongst white Australians

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    Proof oSubjective intergroup beliefs and authoritarianism were assessed in a field study (N= 255) of White Australiansā€™ anti-Asian stereotyping and prejudice. A social identity analysis of intergroup prejudice was adopted, such that perceptions of the intergroup structure (instability, permeability, legitimacy and higher ingroup status) were proposed as predictors of higher prejudice (blatant and covert) and less favorable stereotyping. Consistent with the social identity approach, both independent and interacting roles for sociostructural predictors of Anti-Asian bias were observed, even after demographic and personality variables were controlled. For example, perceived legitimacy was associated with higher prejudice when White Australiansā€™ status position relative to Asian Australians was valued. Moreover, when participants evaluated Whitesā€™ position as unstable and high status or legitimate, perceptions of permeable intergroup boundaries were associated with anti-Asian bias. The present findings demonstrate status protection responses in advantaged group members in a field setting, lending weight to the contention that perceptions of sociostructural threat interact to predict outgroup derogation. Implications for theories of intergroup relations are discussed

    High-performance Si microwire photovoltaics

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    Crystalline Si wires, grown by the vaporā€“liquidā€“solid (VLS) process, have emerged as promising candidate materials for lowcost, thin-film photovoltaics. Here, we demonstrate VLS-grown Si microwires that have suitable electrical properties for high-performance photovoltaic applications, including long minority-carrier diffusion lengths (L_n Ā» 30 Āµm) and low surface recombination velocities (S Ā« 70 cmĀ·s^(-1)). Single-wire radial pā€“n junction solar cells were fabricated with amorphous silicon and silicon nitride surface coatings, achieving up to 9.0% apparent photovoltaic efficiency, and exhibiting up to ~600 mV open-circuit voltage with over 80% fill factor. Projective single-wire measurements and optoelectronic simulations suggest that large-area Si wire-array solar cells have the potential to exceed 17% energy-conversion efficiency, offering a promising route toward cost-effective crystalline Si photovoltaics

    Si microwire-array solar cells

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    Si microwire-array solar cells with Air Mass 1.5 Global conversion efficiencies of up to 7.9% have been fabricated using an active volume of Si equivalent to a 4 Ī¼m thick Si wafer. These solar cells exhibited open-circuit voltages of 500 mV, short-circuit current densities (J_(sc)) of up to 24 mA cm^(-2), and fill factors >65% and employed Al_2O_3 dielectric particles that scattered light incident in the space between the wires, a Ag back reflector that prevented the escape of incident illumination from the back surface of the solar cell, and an a-SiN_x:H passivation/anti-reflection layer. Wire-array solar cells without some or all of these design features were also fabricated to demonstrate the importance of the light-trapping elements in achieving a high J_(sc). Scanning photocurrent microscopy images of the microwire-array solar cells revealed that the higher J_(sc) of the most advanced cell design resulted from an increased absorption of light incident in the space between the wires. Spectral response measurements further revealed that solar cells with light-trapping elements exhibited improved red and infrared response, as compared to solar cells without light-trapping elements
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