Complete elimination of 1K Pot vibrations in dilution refrigerators

Cryogenic vibrations generated by continuously filled 1K Pots are a well known source of noise in all cryogenic experiments using dilution refrigerators. Starting from recent developments we realized a non invasive modification to the cryostat that completely eliminated vibrations, thermalizing the helium coming from the main bath at the pot temperature. We describe the new experimental setup and complete study of the phenomena

The CUORE Experiment: Bolometric Detectors in 1-Ton Scale Projects

CUORE is the first of a new generation 1-ton scale cryogenic detectors for rare events physics. CUORE, a detector to search neutrinoless Double Beta Decay of 130Te, is an array of 988 TeO2 bolometers that will work at 10 mK. Latest developments on detectors performances are reported together with improvements reached in background reduction. Results of CUORICINO, a single CUORE tower running since 2003, that widely showed the feasibility of the project are also reported and discussed

Comparison of predicted and measured elastohydrodynamic film thickness in a 20-millimeter-bore ball bearing

Elastohydrodynamic film thicknesses were measured for a 20-mm bore ball bearing using the capacitance technique. The bearing was thrust loaded to 90, 445, and 778 N (20, 100, and 175 lb). The corresponding maximum contact stress on the inner race was 1.28, 2.09, and 2.45 GPa (185 000, 303,000, and 356, 000 psi). Test speeds ranged from 400 to 15,000 rpm. Measurements were taken with four different lubricants: (1) synthetic paraffinic; (2) synthetic paraffinic with additives; (3) synthetic type II aircraft oil; and (4) synthetic cycloaliphatic hydrocarbon traction fluid. The test bearing was mist lubricated. Test temperatures were 27, 65, and 121 C (80, 150, and 250 F). The measured results for the various test parameters were compared to theoretical predictions from computer programs. Also the data were plotted on dimensionless coordinates and compared to several classical isothermal theories

1.3 kg bolometers to search for rare events

Abstract Two TeO 2 crystal bolometers of 1.3 kg each, the largest single crystals ever operated with this technique, have been successfully realized and tested below 10 mK, in a dilution refrigerator located deep underground in the Gran Sasso National Laboratories. The calibration spectrum, obtained using an external 232Th γ -ray source, shows an energy resolution of 3–4 keV FWHM from 0.5 to 2.6 MeV, for both detectors. In the α region, a 4.3 keV FWHM resolution has been observed on the 5407 keV peak due to the α decay of 210Po, a natural contaminant of TeO 2 crystals

The effect of personality on collaborative task performance and interaction

Collocated, multi-user technologies, which support group-work are becoming increasingly popular. Examples include MERL's Diamondtouch and Microsoft's Surface, both of which have evolved from research prototypes to commercial products. Many applications have been developed for such technologies which support the work and entertainment needs of small groups of people. None of these applications however, have been studied in terms of the interactions and performances of their users with regards to their personality. In this paper, we address this research gap by conducting a series of user studies involving dyads working on a number of multi-user applications on the DiamondTouch tabletop device

Antennal Phenotype of Triatoma dimidiata Populations and Its Relationship with Species of phyllosoma and protracta Complexes

Triatoma dimidiata (Latreille 1811) Reduviidae Triatominae is the main vector of Chagas disease in several countries of Latin America. As for other vector species, the characterization of T. dimidiata subpopulations within particular geographical regions or occupying different habitats could help in better planning of vector control actions. A Þrst objective in this study was to evaluate the antennal phenotype as a phenetic marker to characterize populations of T. dimidiata collected in different geographic areas and domestic and sylvatic habitats. A second objective was to evaluate the phenetic relationships of T. dimidiata with other species of the phyllosoma complex: longipennis, pallidipennis, and phyllosoma. The antennal sensilla of T. dimidiata specimens collected in Mexico, Central America, and Colombia were analyzed and compared with the antennal sensilla of T. longipennis, T. pallidipennis, and T. phyllosoma. T. barberi was used as an outgroup in the analysis. For each specimen, the ventral side of the three distal segments of the antennae was drawn, identifying and counting four types of sensilla. In T. dimidiata, univariate and multivariate analysis showed differences between sexes, among populations collected in different habitats within the same region, and among populations collected in different geographic regions. Two types of antennal sensilla showed a latitudinal variation. Domestic specimens showed intermediate characteristics of the antennal phenotype, between sylvatic cave- and sylvatic forest-collected specimens. The antennal phenotypes show high similarities among T. pallidipennis, T. phyllosoma, and T. longipennis, with a better differentiation of T. pallidipennis. T. dimidiata is separated from the other members of the complex by a similar distance to T. barberi, of the protracta complex.Fil: Catala, Silvia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Sachetto, C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Moreno, Mariana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Rosales, R.. Universidad de San Carlos; GuatemalaFil: Salazar Schettino, P. M.. Universidad Nacional Autónoma de México; MéxicoFil: Gorla, David Eladio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; Argentin

The spatial pattern of “Mal de Río Cuarto del Maíz” (Rio Cuarto Corn disease) in corn fields

Se estudió el patrón de disposición espacial del “Mal de Rio Cuarto del maíz “ durante tres campañas agrícolas en la Provincia de Córdoba, Argentina. El trabajo combinó estimaciones por la prueba de ELISA en un campo experimental durante la primera campaña, con datos de .síntomas microscópicos tomados en la misma situación y en campos comerciales durante dos campañas posteriores. Las muestras analizadas por medio de ELISA mostraron un patrón espacial de la enfermedad indistinguible del esperado por izar. Los datos de síntomas, analizados mediante el “test común de runs “, mostraron que solo 13 de las 120 muestras estudiadas en la primera campaña en el campo experimental tenían disposición espacial agregada y que sólo 3 de lis 23 muestras analizadas en los campos comerciales durante dos campañas posteriores mostraron agregación. No se identificó ningún gradiente de incidencia de Mal de Rio Cuarto desde el perímetro al centro del cultivo, observación que sugiere que el vector no se dispersa a lotes de maíz desde fuentes cercanas.The spatial pattern of Mal de Río Cuarto del maíz (Rio Cuarto Corn Disease) was studied during three growing seasons in Córdoba Province, Argentina. The study combined ELISA determinations in experimental plots outside the endemic area during the first growing season with symptom assessments in that situation and in commercial plots in or near the endemic area during the two subsequent growing seasons. For the experimental plots studied during the first growing season, ELISA data indicated i random spatial pattern of the disease, whereas symptoms data, analyzed by ordinary runs test, showed only 13 out of 120 simples with clumped pattern. Symptom analysis during the next two seasons revealed only 3 of 23 samples with significant aggregation. No edge-to-center disease gradients were identified, suggesting that the vector does not disperse from nearby sources. Our results agree with the hypothesis of a random spatial pattern of this disease, consistent with i monocyclic nature

Asymptotic Boundary-Layer Solutions for Mixed Convection from a Vertical Surface in a Micropolar Fluid

Using the theory of micropolar fluids due to Eringen, asymptotic boundary layer solutions are presented to study the combined convection from a vertical semi-infinite plate to a micropolar fluid. Consideration is given to the region close to the leading edge as well as the region far away from the leading edge. Numerical results are obtained for the velocity, angular velocity and temperature distribution. The missing wall values of the velocity, angular velocity and thermal functions are tabulated. Micropolar fluids display drag reduction and reduced surface heat transfer rate when compared to Newtonian fluids

Asymptotic Boundary-Layer Solutions for Mixed Convection from a Vertical Surface in a Micropolar Fluid

Using the theory of micropolar fluids due to Eringen, asymptotic boundary layer solutions are presented to study the combined convection from a vertical semi-infinite plate to a micropolar fluid. Consideration is given to the region close to the leading edge as well as the region far away from the leading edge. Numerical results are obtained for the velocity, angular velocity and temperature distribution. The missing wall values of the velocity, angular velocity and thermal functions are tabulated. Micropolar fluids display drag reduction and reduced surface heat transfer rate when compared to Newtonian fluids