Manufacturing of a Ceramic Turbine Rotor for a Compact Jet Engine

The primary goal of this study was to develop a low-cost, timely, scalable manufacturing method that produced a ceramic turbine that can be tested as a drop-in replacement on a JetCat P400 small scale gas turbine engine. This research compared two processes for manufacturing a ceramic turbine utilizing a pour casting method and 3D printing using stereolithography ceramic manufacturing (SLCM). The pour casting method used Silicon Nitride to create a cast turbine using a sacrificial 3D printed mold. The SLCM method evaluated producing an alumina turbine using an ADMATEC Admaflex 300 SLCM printer to directly print a ceramic turbine. This study covers the finite element analysis of multiple designs and detailed overview of the varying manufacturing processes as well as lessons learned. It also covers how the turbines would be tested and incorporated into JetCat P400

Synchronized single electron emission from dynamical quantum dots

We study synchronized quantized charge pumping through several dynamical quantum dots (QDs) driven by a single time modulated gate signal. We show that the main obstacle for synchronization being the lack of uniformity can be overcome by operating the QDs in the decay cascade regime. We discuss the mechanism responsible for lifting the stringent uniformity requirements. This enhanced functionality of dynamical QDs might find applications in nanoelectronics and quantum metrology.Comment: 4 pages, 3 figures, submitted to AP

Reliability and validity of the ActivPAL activity monitor for office-based tasks

The ActivPAL physical activity monitor has been previously reported as a reliable and valid tool to measure everyday physical activities. The aim of this study was to examine the reliability and validity of the ActivPAL during typical office-based activities. A convenient sample of 10 adults participated in this study with two ActivPAL units attached to the participant's right thigh. Participants completed 6 minutes of specific office-based tasks such as typing an email, writing on a whiteboard, collecting printing and running a small errand with instructions provided through an audio recording. Each bout was filmed with time of sitting, standing and walking visually assessed using the same categories provided by the ActivPAL analysis. Reliability between ActivPAL recordings was assessed via Wilcoxon comparisons and intraclass correlation coefficients (ICC). Relative error was calculated as the difference between visual observations and ActivPAL recordings. Validity was assessed via Wilcoxon comparisons between ActivPAL recordings and video observations. There were no significant differences between ActivPAL units for sitting (196.2+/-5.0 vs. 195.9+/-5.1 seconds), standing (121.8+/-4.8 vs. 122.3+/-6.9 seconds) or walking (42.0+/-6.1 vs. 41.9+/-7.1 seconds) activities. Significant ICC were detected for sitting (0.928), standing (0.849) and walking (0.849) time. In contrast, the ActivPAL recordings for sitting, standing and walking time were significantly different to visual observations (p3.8%, >24.5% and >54.1%, respectively. The current study has identified ActivPAL units as reliable tools to document physical activity. However, the ActivPAL underestimated sitting and walking time, and overestimated standing time during office-based tasks

Team performance indicators explain outcome during women's basketball matches at the Olympic games

The Olympic Games is the pinnacle international sporting competition with team sport coaches interested in key performance indicators to assist the development of match strategies for success. This study examined the relationship between team performance indicators and match outcome during the women's basketball tournament at the Olympic Games. Team performance indicators were collated from all women's basketball matches during the 2004-2016 Olympic Games (n = 156) and analyzed via linear (binary logistic regression) and non-linear (conditional interference (CI) classification tree) statistical techniques. The most parsimonious linear model retained "defensive rebounds", "field-goal percentage", "offensive rebounds", "fouls", "steals", and "turnovers" with a classification accuracy of 85.6%. The CI classification tree retained four performance indicators with a classification accuracy of 86.2%. The combination of "field-goal percentage", "defensive rebounds", "steals", and "turnovers" provided the greatest probability of winning (91.1%), while a combination of "field-goal percentage", "steals", and "turnovers" provided the greatest probability of losing (96.7%). Shooting proficiency and defensive actions were identified as key team performance indicators for Olympic female basketball success. The development of key defensive strategies and/or the selection of athletes highly proficient in defensive actions may strengthen Olympic match success. Incorporation of non-linear analyses may provide teams with superior/practical approaches for elite sporting success

Community Structure in Time-Dependent, Multiscale, and Multiplex Networks

Network science is an interdisciplinary endeavor, with methods and applications drawn from across the natural, social, and information sciences. A prominent problem in network science is the algorithmic detection of tightly-connected groups of nodes known as communities. We developed a generalized framework of network quality functions that allowed us to study the community structure of arbitrary multislice networks, which are combinations of individual networks coupled through links that connect each node in one network slice to itself in other slices. This framework allows one to study community structure in a very general setting encompassing networks that evolve over time, have multiple types of links (multiplexity), and have multiple scales.Comment: 31 pages, 3 figures, 1 table. Includes main text and supporting material. This is the accepted version of the manuscript (the definitive version appeared in Science), with typographical corrections included her

Physical, anthropometric and athletic movement qualities discriminate development level in a rugby league talent pathway

This study compared the physical, anthropometric and athletic movement qualities of talent identified rugby league (RL) players within a development pathway. From a total of 174 players, three developmental levels were defined: under 18 (U18; n = 52), under 20 (U20; n = 53), and state league (SL; n = 69). All players performed a test battery that consisted of five physical assessments, two anthropometric measurements and an athletic movement assessment. A multivariate analysis of variance modelled the main effect of developmental level (Three levels: U18, U20 and SL) on test criterion variables. Receiver operating characteristic (ROC) curves were then built for the criterion variables that showed a significant developmental level effect. A significant effect was noted (V = 0.775, F = 5.43, P <0.05), with the SL players outperforming their U18 and U20 counterparts for measures of body mass, peak and average lower limb power, double lunge (left side), single leg Romanian deadlift (left and right sides), the push up, and total athletic ability assessment score (P<0.05; d = 0.35 – 1.21). The ROC curves generated an area under the curve of greater than 65% for each test criterion, indicating greater than chance discrimination. These results highlight the physical, anthropometric and athletic movement qualities discriminant of development level within a rugby league talent pathway. Practitioners are encouraged to consider the thresholds from the ROC curves as an objective guide to assist with the development of physical performance qualities that may augment player progression in Australian rugby league

Vertex similarity in networks

We consider methods for quantifying the similarity of vertices in networks. We propose a measure of similarity based on the concept that two vertices are similar if their immediate neighbors in the network are themselves similar. This leads to a self-consistent matrix formulation of similarity that can be evaluated iteratively using only a knowledge of the adjacency matrix of the network. We test our similarity measure on computer-generated networks for which the expected results are known, and on a number of real-world networks

A multi-factorial assessment of elite paratriathletes’ response to two weeks of intensified training

Purpose: In able-bodied athletes, several hormonal, immunological and psychological parameters are commonly assessed in response to intensified training due to their potential relationship to acute fatigue and training/non-training stress. This has yet to be studied in Paralympic athletes. Methods: Ten elite paratriathletes were studied for five weeks around a 14-day overseas training camp whereby training load was 137% of pre-camp levels. Athletes provided: six saliva samples (one pre-camp, four during camp, one post-camp) for cortisol, testosterone and secretory immunoglobulin A; weekly psychological questionnaires (POMS and RESTQ-S); daily resting heart rate and subjective wellness measures including sleep quality and quantity. Results: There was no significant change in salivary cortisol, testosterone, cortisol:testosterone ratio or secretory immunoglobulin A during intensified training (p≥0.090). Likewise, there was no meaningful change in resting heart rate or subjective wellness measures (p≥0.079). Subjective sleep quality and quantity increased during intensified training (p≤0.003). There was no significant effect on any POMS subscale other than lower anger (p=0.049) whilst there was greater general recovery and lower sport and general stress from RESTQ-S (p≤0.015). Conclusions: There was little to no change in parameters commonly associated with the fatigued state which may relate to the training camp setting minimising external life stresses and the careful management of training loads from coaches. This is the first evidence of such responses in Paralympic athletes