Numerical modelling of free-surface flows

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Synchronization and Characterization of an Ultra-Short Laser for Photoemission and Electron-Beam Diagnostics Studies at a Radio Frequency Photoinjector

A commercially-available titanium-sapphire laser system has recently been installed at the Fermilab A0 photoinjector laboratory in support of photoemission and electron beam diagnostics studies. The laser system is synchronized to both the 1.3-GHz master oscillator and a 1-Hz signal use to trigger the radiofrequency system and instrumentation acquisition. The synchronization scheme and performance are detailed. Long-term temporal and intensity drifts are identified and actively suppressed to within 1 ps and 1.5%, respectively. Measurement and optimization of the laser's temporal profile are accomplished using frequency-resolved optical gating.Comment: 16 pages, 17 figures, Preprint submitted to Elsevie

Isostaticity of Constraints in Jammed Systems of Soft Frictionless Platonic Solids

The average number of constraints per particle $$ in mechanically stable systems of Platonic solids (except cubes) approaches the isostatic limit at the jamming point ($\rightarrow 12$), though average number of contacts are hypostatic. By introducing angular alignment metrics to classify the degree of constraint imposed by each contact, constraints are shown to arise as a direct result of local orientational order reflected in edge-face and face-face alignment angle distributions. With approximately one face-face contact per particle at jamming chain-like face-face clusters with finite extent form in these systems.Comment: 4 pages, 3 figures, 4 tabl

John Blair Deaver, M.D., and his marvelous retractor.

John Blair Deaver was born near Buck, Pennsylvania, in Lancaster County on July 25, 1855, to Dr. Joshua Montgomery Deaver and Elizabeth Clair Moore. The elder Deaver was a reputable country physician, educated at the University of Maryland, who fathered three physicians and a college president. John Blair Deaver (Fig. 1) went to boarding school at West Nottingham Academy in Maryland. After boarding school he taught in Lancaster County country schools to raise funds to attend the nation’s first medical school, the University of Pennsylvania. On receiving his M.D. degree in 1878, Dr. Deaver completed 1-year internships at both Germantown Hospital and Philadelphia Children’s Hospital, after which he embarked into clinical practice. Alongside his brother, Dr. Harry Clay Deaver, he made home visits to patients to perform surgeries as well as managed a busy 16th Street and Vine Street Philadelphia office

Emerging schooling landscapes in England: how primary system leaders are responding to new school groupings

In England the balance of responsibilities between national and local government for the governance of education is changing. Relationships between schools are shifting and new structures, groups and alliances are being created in response to national policy. The paper is part of a project to understand how the new local education landscapes are emerging. Primary schools are relatively reluctant to embrace key aspects of national policy. We analysed interviews with primary system leaders in three contrasting Local Authorities to find how they were responding, and why, and the nature of the groups they wanted to join, create or cooperate with. We identify concerns, interests and motivations that conflict with key aspects of national policy. In the process we supplement earlier contributions as to how school groupings might usefully be categorised

Effects of the Boy Scouts of America Personal Fitness Merit Badge on Cardio-Metabolic Risk, Health Related Fitness and Physical Activity in Adolescents Boys

International Journal of Exercise Science 10(7): 964-976, 2017. A growing number of adolescents are more sedentary and have fewer formal opportunities to participate in physical activity. With the mounting evidence that sedentary time has a negative impact on cardio-metabolic profiles, health related fitness and physical activity, there is a pressing need to find an affordable adolescent physical activity intervention. One possible intervention that has been overlooked in the past is Boy Scouts of America. There are nearly 900,000 adolescent boys who participate in Boy Scouts in the United States. The purpose of this research study was to evaluate the effect of the Personal Fitness merit badge system on physical activity, health-related fitness, and cardio-metabolic blood profiles in Boy Scouts 11-17 years of age. Participants were fourteen (N = 14) Boy Scouts from the Great Salt Lake Council of the Boy Scouts of America who earned their Personal Fitness merit badge. Classes were held in the Spring of 2016 where boys received the information needed to obtain the merit badge and data were collected. Results from the related-samples Wilcoxon signed rank test showed that the median of differences between VO2 peak pre-test and post-test scores were statistically significant (p = 0.004). However, it also showed that the differences between the Pre-MetS (metabolic syndrome) and Post-MetS scores (p = 0.917), average steps taken per day (p = 0.317), and BMI (p = 0.419) were not statistically significant. In conclusion, the merit badge program had a positive impact on cardiovascular endurance, suggesting this program has potential to improve cardiovascular fitness and should be considered for boys participating in Boy Scouts