Science and technology of BOREXINO: A Real time detector for low-energy solar neutrinos: A Real Time Detector for Low Energy Solar Neutrinos

BOREXINO, a real-time device for low energy neutrino spectroscopy is nearing completion of construction in the underground laboratories at Gran Sasso, Italy (LNGS). The experiment's goal is the direct measurement of the flux of 7Be solar neutrinos of all flavors via neutrino-electron scattering in an ultra-pure scintillation liquid. Seeded by a series of innovations which were brought to fruition by large scale operation of a 4-ton test detector at LNGS, a new technology has been developed for BOREXINO. It enables sub-MeV solar neutrino spectroscopy for the first time. This paper describes the design of BOREXINO, the various facilities essential to its operation, its spectroscopic and background suppression capabilities and a prognosis of the impact of its results towards resolving the solar neutrino problem. BOREXINO will also address several other frontier questions in particle physics, astrophysics and geophysics

Machine learning uncovers the most robust self-report predictors of relationship quality across 43 longitudinal couples studies

Given the powerful implications of relationship quality for health and well-being, a central mission of relationship science is explaining why some romantic relationships thrive more than others. This large-scale project used machine learning (i.e., Random Forests) to 1) quantify the extent to which relationship quality is predictable and 2) identify which constructs reliably predict relationship quality. Across 43 dyadic longitudinal datasets from 29 laboratories, the top relationship-specific predictors of relationship quality were perceived-partner commitment, appreciation, sexual satisfaction, perceived-partner satisfaction, and conflict. The top individual-difference predictors were life satisfaction, negative affect, depression, attachment avoidance, and attachment anxiety. Overall, relationship-specific variables predicted up to 45% of variance at baseline, and up to 18% of variance at the end of each study. Individual differences also performed well (21% and 12%, respectively). Actor-reported variables (i.e., own relationship-specific and individual-difference variables) predicted two to four times more variance than partner-reported variables (i.e., the partner’s ratings on those variables). Importantly, individual differences and partner reports had no predictive effects beyond actor-reported relationship-specific variables alone. These findings imply that the sum of all individual differences and partner experiences exert their influence on relationship quality via a person’s own relationship-specific experiences, and effects due to moderation by individual differences and moderation by partner-reports may be quite small. Finally, relationship-quality change (i.e., increases or decreases in relationship quality over the course of a study) was largely unpredictable from any combination of self-report variables. This collective effort should guide future models of relationships

Resolving Apparent Differences between Heat and Density Pulse-Propagation in Jet and Text

Sawtooth induced heat and density pulse measurements reported in the literature for the JET and TEXT experiments are discussed. In JET the heat pulse travels ten times faster than the density pulse, but in TEXT both pulses travel at the same speed. The measurements are analysed using coupled transport equations for energy and particles. It is shown that the different behaviour of the density pulse in the two experiments can be attributed to differences in the off-diagonal elements of the transport matrix. If the perturbed fluxes of heat and particles are expressed as linear combinations of the thermodynamic forces del p and del T (rather than del n and del T), the corresponding transport matrices are remarkably similar. However, minor differences in this transport matrix between JET and TEXT account for the qualitative difference in the density pulses

Tokamak Transport Studies Using Perturbation Analysis

Studies of the transport properties of tokamak plasmas using perturbation analysis are discussed. The focus is on experiments with not too large perturbations, such as sawtooth induced heat and density pulse propagation, power modulation and oscillatory gas-puff experiments. The approximations made in the standard analysis of such experiments are made explicit and are discussed. References are given to papers that deal with specific aspects of the theory. Points of agreement as well as discrepancies between different experiments and gaps in the experimental data base are highlighted. The analysis of cross-coupling between electron thermal and particle transport using simultaneous measurements of heat and density pulses in JET is discussed, as an illustration of the potentiality to measure off-diagonal elements of the transport matrix in perturbative experiments