The LUX-ZEPLIN (LZ) radioactivity and cleanliness control programs

LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above 1.4×10−48cm2 for a WIMP mass of 40GeV/c2 and a 1000days exposure. LZ achieves this sensitivity through a combination of a large 5.6t fiducial volume, active inner and outer veto systems, and radio-pure construction using materials with inherently low radioactivity content. The LZ collaboration performed an extensive radioassay campaign over a period of six years to inform material selection for construction and provide an input to the experimental background model against which any possible signal excess may be evaluated. The campaign and its results are described in this paper. We present assays of dust and radon daughters depositing on the surface of components as well as cleanliness controls necessary to maintain background expectations through detector construction and assembly. Finally, examples from the campaign to highlight fixed contaminant radioassays for the LZ photomultiplier tubes, quality control and quality assurance procedures through fabrication, radon emanation measurements of major sub-systems, and bespoke detector systems to assay scintillator are presented

Un enfoque psicológico complementario para la investigación en el hábitat popular que redefine el tema-problema

Fil: Peyloubet, Paula. Centro Experimental de la Vivienda Económica, Argentina.Fil: Peyloubet, Paula. CONICET, Argentina.Fil: O’neill, Tomás. Centro Experimental de la Vivienda Económica, Argentina.Fil: O’neill, Tomás. CONICET, Argentina.El presente artículo intenta aportar algunos aspectos que caracterizan la pobreza y su relación con el hábitat popular, y hacer una interpretación diferente de la misma desde una visión ampliada y el reconocimiento de nuevos indicadores generadores de dinámica para el sector. En ese sentido, un enfoque epistemológico alternativo. aparecerá respecto a lo que se considera el hábitat popular y su relación con la población pobre, en cuanto a sus potencialidades y no solo de sus deficiencias, en la búsqueda de resoluciones diferentes y efectivas. Se considerarán los aspectos individuales y manifestaciones que contribuyen al desarrollo de los sistemas colectivos a partir de los logros compartidos en común. Se considerará como hipótesis de partida la existencia del factor humano como determinante del avance en el hábitat aún en situaciones adversas

Cabriadas de “par y tirante” con madera Pinus Elliottii

Una alternativa de solución para techos con madera, a base de componentes estructurales tipo Cabriadas y cubierta de machihembrado, tableros o similar. Los componentes estructuralesprincipales de las Cabriadas se conforman con seis elementosconsistentes en secciones de tablas de madera de Pino Elliottii, de iguales dimensiones en escuadría y longitud. Para el acabado final de la cubierta se estudia y compara la utilización detejas francesas y láminas de chapa metálica sinusoidal.Se reseñan diseño, cálculos estructurales y definición dimensional de los elementos y componentes de las cubiertas.Se resumen los resultados y recomendaciones de una maneragráfica, para fácil lectura y comprensión de la propuestaconstructiva y como llevarla a cabo a los fines del traspasoy transferencia tecnológica al habitante, para la autogestiónen la producción de viviendas.DescriptoresCabriadas, pinus elliottii; techos de maderaAbstractThe proposal is an alternate solution for wooden ceilings, based on truss-like structural components covered with woven dovetail joints, wood panels or similar plates.The main structural components of trusses are made with six elements consisting in board sections made from Pinus Elliottii wood, each one with equal dimensions in length and angles.For the finish, in this paper we’ve studied and compared the use of French roof tiles and metal sinusoidal sheets.The text describes the design, structural calculations and definition of the dimensions of the elements and components of the covers. The results and recommendations are summarized with graphics.The construction proposal and its execution are offered in an easy-to-understand way in lieu of transferring the technology to the tenant and thus aid the autonomous housing construction.Descriptorstrusses, Pinus Elliottii, wood roo

El agua: fuente de vida y un recurso estratégico por preservar

Los costos de la infraestructura sanitaria, la escasez de agua potable y la carencia de un adecuado sistema de salud, hechosque afectan a gran parte de la población, han motivado intentos de nuevas búsquedas en el diseño de la vivienda individual y colectiva, lo cual ha generado diversas técnicas y formas funcionales relacionadas con la instalación, uso y mantenimiento de redes de provisión y evacuación y, en consecuencia, la accesibilidad a los mismos para su reparación o reposición. Las instalaciones sanitarias, en particular, presentan una problemática compleja, aún no resuelta en la vivienda de los sectores pobres.Con este enfoque y durante tres décadas, se han desarrollado en elCentro Experimental de la Vivienda Económica-CEVE, en Córdoba (Argentina), diversas alternativas sanitarias orientadas a la autogestión y autoconstrucción en el marco de la Producción Socialdel Hábitat, a través de proyectos de Investigación. Los “Muebles Sanitarios” que aquí se presentan son algunos de los resultados de esas acciones.DescriptoresMuebles sanitarios, Hidro-domésticos de producciónindustrial, Aporte a la economía de agua potable.AbstractThe costs of the sanitary substructure, the drinkable water shortage and the lack of an adequate health system, facts thataffect a great amount of the population, have motivated attempts of new searches in the individual and collective housing design, which has produced diverse techniques as well as functional forms related to the installation, uses and maintenance of the evacuation and provision nets, and, in consequence, their accessibility for its repair or replacement. Particularly, the sanitary installation have complex problems, not yet solved in the poor sector housing. With this view and during three decades, have been developed, inthe Experimental Center of the Economic Housing –CEVE, Córdoba (Argentina), through investigation projects,diverse sanitary alternatives directed to the selfmanagementand construction in the Environment Social Production. The “Sanitary Furnitures” which are presented in this paperare some of the results of those actions.DescriptorsSanitary furnitures,Hydric devices of industrial production, Contribution tothe drinkable water econom

α-1 Antitrypsin regulates human neutrophil chemotaxis induced by soluble immune complexes and IL-8

Hereditary deficiency of the protein α-1 antitrypsin (AAT) causes a chronic lung disease in humans that is characterized by excessive mobilization of neutrophils into the lung. However, the reason for the increased neutrophil burden has not been fully elucidated. In this study we have demonstrated using human neutrophils that serum AAT coordinates both CXCR1- and soluble immune complex (sIC) receptor–mediated chemotaxis by divergent pathways. We demonstrated that glycosylated AAT can bind to IL-8 (a ligand for CXCR1) and that AAT–IL-8 complex formation prevented IL-8 interaction with CXCR1. Second, AAT modulated neutrophil chemotaxis in response to sIC by controlling membrane expression of the glycosylphosphatidylinositol-anchored (GPI-anchored) Fc receptor FcγRIIIb. This process was mediated through inhibition of ADAM-17 enzymatic activity. Neutrophils isolated from clinically stable AAT-deficient patients were characterized by low membrane expression of FcγRIIIb and increased chemotaxis in response to IL-8 and sIC. Treatment of AAT-deficient individuals with AAT augmentation therapy resulted in increased AAT binding to IL-8, increased AAT binding to the neutrophil membrane, decreased FcγRIIIb release from the neutrophil membrane, and normalization of chemotaxis. These results provide new insight into the mechanism underlying the effect of AAT augmentation therapy in the pulmonary disease associated with AAT deficiency