aCORN: Measuring the electron-antineutrino correlation in neutron beta decay

The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line obtained the result a = 0.1090 +/- 0.0030 (stat) +/- 0.0028 (sys), the most precise to date. The second run on the new NG-C high flux beam line promises an improvement in precision to ¡ 2%. In addition we show that an improved measurement of the neutrino asymmetry (B-coefficient) can be made using the aCORN apparatus on a highly polarized neutron beam.

Effects of Attentional and Motivational Priming on Athletic Performance

The effect of motivational and attentional primes on athletic performance was assessed. Thirty-four male, recreational basketball players shot 10 free throws after completing a word scrambled sentence task that primed either autonomous motivation, fluency, or nothing (control). Results revealed that neither prime significantly increased free throw scores more than the control, but fluency primed participants scored significantly more free throws than autonomous motivation primed participants. Results provide support that athletes should try to relax during high pressure situations that require precision. Focusing on the task at hand will hinder performance, while naturally going through the motions will enhance performance. Results also provided support that there is an optimal level of arousal for performing one’s best. Too low or too high of arousal actually hinders an athlete’s performance.

Elbow Musculoskeletal Model for Industrial Exoskeleton with Modulated Impedance Based on Operator’s Arm Stiffness

With the ageing of the workforce in the manufacturing industry, the possibility of introducing support aids such as exoskeletons to reduce the fatigue and effort of the operator has to be evaluated. An upper-limb exoskeleton with controlled impedance is expected to reduce the discomfort in the operations which require precision. Hence, arm joint stiffening is required. Real-time calculation of the exoskeleton impedance should be based on the operator’s limb impedance, evaluated through electromyographic signals. A model of the operator’s arm is necessary to identify the best control law for the exoskeleton. In this paper, preliminary considerations and a model of the elbow on which two muscles act as agonist-antagonist are presented. Numerical results are discussed, and an estimation of the performance is also proposed.

Ultra Precise Positioning of a Stage Driven by Pneumatic Bellows

Ultra precise positioning techniques that support nanotechnologies led by the semiconductor industry mainly require precision of nanometer order. Currently, it is piezoelectric elements that are most often used for positioning control of this order. Piezoelectric elements, however, are deficient in strokes and durability. In this research, we propose to use for ultra precise positioning control pneumatic bellows instead of piezoelectric elements, because the durability of pneumatic bellows is well proven. Specifically, we manufacture an elastic-hinge-guided, fine-motion stage which is driven by pneumatic bellows. In addition, we have developed a mathematical model for this fine-motion stage as well as its dynamic characteristics. We review feedback control to achieve ultra precise positioning, using the developed stage and mathematical model. As a result, we have succeeded in developing a fine-motion stage with longer strokes than ones driven by piezoelectric elements, though it is inferior in response. Positioning accuracy of the pneumatic-bellowdriven stage is ±5 [nm], which is tantamount to that achieved by piezoelectric elements.

Causation in the Law

Previous accounts of ‘causation’ in the law are flawed by their failure to appreciate that causal language is used to express different information about the world. Because causal terms have been used to communicate answers to different questions, any philosophical search for a free-standing account of causation is doomed. Lawyers require precision of terminology, so they should explicitly choose just one interrogation to underlie causal usage in law. It is argued that this interrogation should be chosen to serve the wide projects of the law. In these projects the law is interested to identify when a specified factor was ‘involved’ in the existence of a particular phenomenon, where the notion of ‘involvement’ identifies a contrast between the actual world and some specified hypothetical world from which we exclude (at least) that specified factor: this contrast being that, while in the former world the phenomenon exists, in the latter it does not. (Such contrasts of necessity can be generated in three ways, all of importance to the law.)

Quality control in radiotherapy of brain tumors

(Conclusion) Radiotherapy techniques for brain tumors are complex and require precision in planning and giving radiotherapy programs. Continual application of quality control should enable achieving better treatment results with minimizing risk for late treatment-related complications. Introduction of uniform and precise parameters for the therapy planning, dose determining and patient's control, makes possible for optimal follow-up and comparison of treatment results between different therapeutic centers.