Solar Concentrators Manufacture and Automation

Solar energy is one of the most promising types of renewable energy. Flat facet solar concentrators were proposed to decrease the cost of materials needed for production. They used small flat mirrors for approximation of parabolic dish surface. The first prototype of flat facet solar concentrators was made in Australia in 1982. Later various prototypes of flat facet solar concentrators were proposed. It was shown that the cost of materials for these prototypes is much lower than the material cost of conventional parabolic dish solar concentrators. To obtain the overall low cost of flat facet concentrators it is necessary to develop fully automated technology of manufacturing and assembling processes. Unfortunately, the design of known flat facet concentrators is too complex for automation process. At present we develop the automatic manufacturing and assembling system for flat facet solar concentrators. For this purpose, we propose the design of flat facet solar concentrator that is convenient for automatization. We describe this design in the paper. At present, almost all solar-energy plants in the world occupy specific areas that are not used for agricultural production. This leads to a competition between the solar-energy plants and agriculture production systems. To avoid this competition, it is possible to co-locate solar-energy devices in agricultural fields. The energy obtained via such co-location can be used for agricultural needs (e.g., water extraction for irrigation) and other purposes (e.g., sent to an electrical grid). In this study, we also describe the results of an investigation on co-location methods for the minimal loss of agricultural harvest too

De la mitigación de desastres a la interrupción de trampas de riesgo: la experiencia de aprendizajeacción de clima sin riesgo

RESUMEN: En las últimas décadas hemos asistido a una profunda reformulación de cómo entender las condiciones de riesgo en el contexto urbano. Sin embargo, aún enfrentamos significativos desafíos para capturar conceptual, metodológica y empíricamente los círculos viciosos de reproducción de riesgos que configuran ‘trampas de riesgo urbano’ frecuentemente invisibilizadas. Entendemos a las trampas de riesgo como el resultado de la reproducción de riesgos cotidianos y de desastres repetitivos y frecuentes de pequeña escala, que afectan en forma desproporcional a los sectores empobrecidos en forma altamente localizada. A partir de cLIMA sin Riesgo - un proyecto de investigación-acción desarrollado por los autores en el contexto de Lima - este artículo explora las condiciones que producen y reproducen estas trampas, cómo y dónde se materializan, quié- nes son afectados y con qué consecuencias para aquellos que viven en barrios tugurizados y/o asentamientos informales y marginalizados. La discusión examina cómo el conocimiento espacial de la urbanización en riesgo y la evaluación critica de las inversiones y los esfuerzos de mitigación realizados por parte de pobladores y agencias estatales permiten avanzar hacia una apreciación más precisa del impacto de dichas trampas a lo largo del tiempo, así como hacia estrategias de acción para su interrupción. ABSTRACT: The last decades have witnessed a profound change in our understanding of the conditions of risk in urban contexts. However, we still face significant conceptual, methodological and empirical challenges in capturing the vicious cycles of risk accumulation that often render so-called ‘urban risk traps’ invisible. We define risk traps as the result of the reproduction of everyday risks and frequent small-scale disasters, which have highly localized impacts and disproportionately affect impoverished inhabitants. Based on the action-research project cLIMA without Risk (cLIMA sin riesgo), which was conducted by the authors in the context of two marginalized areas in the centre and periphery of Lima, Peru, this article explores the conditions that produce and reproduce these risk traps and it analyses how and where they materialize, who they affect and with what consequences. The discussion examines how spatial knowledge of urbanization at risk together with a critical evaluation of inhabitants’ and state agencies’ investments in mitigation efforts allows us to move towards a more accurate assessment of the impact of these risk traps over time, which is required for developing transformative strategies to disrupt them

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum