Making it to the top in team sports:Start later, intensify, and be determined

It is debated whether young athletes need to specialize early, or if it is more beneficial to follow the path of early diversification. The present study investigates the career paths and related motivational and volitional factors of Danish elite and near-elite team sport athletes. Seventy-six athletes matched by sport, age and sex participated in the study. Elite athletes started their career later and showed higher self-determination and lower values in postponing training. The logistic regression showed that fewer accumulated training hours up to age 12, but more up to age 15 significantly predicted elite group membership. All other investigated variables did not show significant results. It is concluded that there are more similarities than differences between the two groups

Operations Systems Engineering for the Lunar Flashlight Mission

Lunar Flashlight, a 6U CubeSat developed by NASA\u27s Jet Propulsion Laboratory (JPL) and operated by students at the Georgia Institute of Technology (GT), was launched in December 2022 with a mission to demonstrate novel small satellite technologies, including a first-of-its-kind green monopropellant system, and to map surface water ice in permanently shadowed regions of the lunar south pole using near-infrared laser reflectometry. As operations systems engineers, the GT team has maintained, developed, and refined models of spacecraft subsystems as well as coordinated the project\u27s approach to anomaly response and fault protection. This paper reports how analysis of flight data and post-launch experiences have allowed the team to make more efficient use of the spacecraft\u27s capabilities by taking advantage of margins, synthesizing data, and adapting flight rules and constraints. In-flight anomalies have required substantial rework of the mission\u27s concept of operations, and anomaly management and resolution has leaned heavily on modeling and predictions from the operations systems engineers. The GT operations team has made full use of available data, including telemetry and observed system behavior, to swiftly recognize and address anomalies, support strenuous recovery efforts, and make possible a realignment of the concept of operations despite significant challenges

Hydrodynamic coupling of two rotating spheres trapped in harmonic potentials

We theoretically study in detail the hydrodynamic coupling of two equal-sized colloidal spheres at low Reynolds numbers assuming the particles to be harmonically trapped with respect to both their positions and orientations. By taking into account the rotational motion, we obtain a rich spectrum of collective eigen modes whose properties we determine on the basis of pure symmetry arguments. Extending recent investigations on translational correlations [J.-C. Meiners and S. R. Quake, Phys. Rev. Lett. 82, 2211 (1999)], we derive the complete set of auto- and cross-correlation functions emphasizing the coupling of rotation to translation which we illustrate in a few examples. An important feature of our system is the self-coupling of translation and rotation of one particle mediated by the neighboring particle that is clearly visible in the appropriate auto-correlation function. This coupling is a higher-order effect and therefore not included in the widely used Rotne-Prager approximation for the hydrodynamic mobilities.Comment: to be published in Phys. Rev.

Method for separating single-wall carbon nanotubes and compositions thereof

The invention relates to a process for sorting and separating a mixture of (n, m) type single-wall carbon nanotubes according to (n, m) type. A mixture of (n, m) type single-wall carbon nanotubes is suspended such that the single-wall carbon nanotubes are individually dispersed. The nanotube suspension can be done in a surfactant-water solution and the surfactant surrounding the nanotubes keeps the nanotube isolated and from aggregating with other nanotubes. The nanotube suspension is acidified to protonate a fraction of the nanotubes. An electric field is applied and the protonated nanotubes migrate in the electric fields at different rates dependent on their (n, m) type. Fractions of nanotubes are collected at different fractionation times. The process of protonation, applying an electric field, and fractionation is repeated at increasingly higher pH to separated the (n, m) nanotube mixture into individual (n, m) nanotube fractions. The separation enables new electronic devices requiring selected (n, m) nanotube types

Selective functionalization of carbon nanotubes

The present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations

Presentasjon av casestudier i REBO

Copyright SINTEF akademisk forlag 201

Methods for selective functionalization and separation of carbon nanotubes

The present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations

Identity of the universal repulsive-core singularity with Yang-Lee edge criticality

Lattice and continuum fluid models with repulsive-core interactions typically display a dominant, critical-type singularity on the real, negative activity axis. Lai and Fisher recently suggested, mainly on numerical grounds, that this repulsive-core singularity is universal and in the same class as the Yang-Lee edge singularities, which arise above criticality at complex activities with positive real part. A general analytic demonstration of this identification is presented here using a field-theory approach with separate representation of the repulsive and attractive parts of the pair interactions.Comment: 6 pages, 3 figure