Core restraint development. Quarterly progress report for period ending August 31, 1975

This quarterly progress covers work performed between June 1, 1975 and August 31, 1975

A Classification of the Vegetation of Boothia Peninsula and the Northern District of Keewatin, N.W.T.

The vegetation of Boothia Peninsula and the northern District of Keewatin (212,500 km²) was surveyed, and a vegetation classification suitable for synoptic level surveys of wildlife habitat was produced. A total of 45 plant communities was recognized on Boothia Peninsula. Principal components and discriminant function analysis were used to identify seven significant groupings of these communities. These seven groups, designated as the vegetation groups for Boothia Peninsula, were: Sedge Meadows, Willow Hummocks, Lichen-Dryas Plateaus, Seepage Slopes, Moss Tundra, Purple-Saxifrage Plains, and Rock Barrens. Forty-two plant communities were recognized in the northern District of Keewatin. The six significant groupings which resulted, and which were designated as the vegetation groups for the northern District of Keewatin, were: Sedge Meadows, Willow-Sedge Meadows, Orthophyll Shrub, Lichen-Heath Plateaus, Lichen Uplands, and Barrens. The species composition and relationship to the physical environment for each of these vegetation groups is described

Distribution and Numbers of the Kaminuriak Caribou Herd in March and April, 1977

The distribution and abundance of the Kaminuriak caribou herd were documented through an aerial survey conducted in March and April 1977. It appears that the herd altered its traditional migration patterns and abandoned its southern wintering grounds in this year at least. The size of the herd was estimated at 30,770 animals - a significant decrease from the 63,000 animals found in 1968. Available data, although limited, suggests that the maximum allowable harvest of 5% of the herd has been exceeded in recent years. Although the possibility exists that some Kaminuriak caribou may have dispersed northward, it is considered most likely that the decline in the size of the herd is the result of overharvesting

Theoretical tool movement required to diamond turn an off-axis paraboloid on axis

High-quality, off-axis parabolic reflectors, required by the CTR and laser-fusion programs at Lawrence Livermore Laboratory (LLL) and other ERDA laboratories, are currently manufactured by hand. There are several drawbacks to this method, including lead times of up to a year, costs in excess of $75,000 for a small reflector, and unsatisfactory limits to the tolerances obtainable. This situation has led to a search for cheaper and more accurate methods of manufacturing off-axis paraboloids. An alternative method, turning the workpiece about its axis on a diamond-turning machine, is presented, and the equations describing the necessary tool movement are derived. A discussion of a particular case suggests that the proposed technique is feasible. (auth

Electron correlation energy in confined two-electron systems

Radial, angular and total correlation energies are calculated for four two-electron systems with atomic numbers Z=0-3 confined within an impenetrable sphere of radius R. We report accurate results for the non-relativistic, restricted Hartree-Fock and radial limit energies over a range of confinement radii from 0.05 - 10 a0. At small R, the correlation energies approach limiting values that are independent of Z while at intermediate R, systems with Z > 1 exhibit a characteristic maximum in the correlation energy resulting from an increase in the angular correlation energy which is offset by a decrease in the radial correlation energy

Helioseismology of Sunspots: A Case Study of NOAA Region 9787

Various methods of helioseismology are used to study the subsurface properties of the sunspot in NOAA Active Region 9787. This sunspot was chosen because it is axisymmetric, shows little evolution during 20-28 January 2002, and was observed continuously by the MDI/SOHO instrument. (...) Wave travel times and mode frequencies are affected by the sunspot. In most cases, wave packets that propagate through the sunspot have reduced travel times. At short travel distances, however, the sign of the travel-time shifts appears to depend sensitively on how the data are processed and, in particular, on filtering in frequency-wavenumber space. We carry out two linear inversions for wave speed: one using travel-times and phase-speed filters and the other one using mode frequencies from ring analysis. These two inversions give subsurface wave-speed profiles with opposite signs and different amplitudes. (...) From this study of AR9787, we conclude that we are currently unable to provide a unified description of the subsurface structure and dynamics of the sunspot.Comment: 28 pages, 18 figure

On the Progenitors of Core-Collapse Supernovae

Theory holds that a star born with an initial mass between about 8 and 140 times the mass of the Sun will end its life through the catastrophic gravitational collapse of its iron core to a neutron star or black hole. This core collapse process is thought to usually be accompanied by the ejection of the star's envelope as a supernova. This established theory is now being tested observationally, with over three dozen core-collapse supernovae having had the properties of their progenitor stars directly measured through the examination of high-resolution images taken prior to the explosion. Here I review what has been learned from these studies and briefly examine the potential impact on stellar evolution theory, the existence of "failed supernovae", and our understanding of the core-collapse explosion mechanism.Comment: 7 Pages, invited review accepted for publication by Astrophysics and Space Science (special HEDLA 2010 issue

The effect of unrestricted milk feeding on the growth and health of Jersey calves

This study was conducted to determine the effect of feeding high milk volumes on the growth rate, health and cross-sucking behaviour in group-fed Jersey calves. Three-day-old heifers (n = 120) in a seasonal calving dairy herd were randomly assigned to one of 6 treatment groups. Three groups received high milk volumes (HMV), consisting of ad libitum milk or milk replacer feeding twice a day, while 3 groups received restricted milk volumes (RMV), consisting of 2 twice daily, during the pre-weaning period. After a pre-weaning period during which feeding was reduced to once daily, all calves were weaned at 42 days and monitored until 60 days of age.Adjusting for birth mass, birth date,damparity and sire, average daily mass gain (ADG), both pre-weaning (days 0–42) and overall (days 0–60), was higher inHMVthan inRMVcalves (P<0.001).After weaning, growth rates showed no differences and at 60 days of age the HMV calves maintained a 6.74 kg advantage in mean body mass (P < 0.001). The mean intake of dry starter feed was higher in RMV than in HMVcalves. Overall feed conversion rate ofHMVcalves was 9.6%better thanRMVcalves. However, the variable cost per kg mass gain was 12 % higher for HMV calves. In the RMV groups 75 % of calves showed cross-sucking behaviour pre-weaning and 18 % post-weaning, whereas in HMV calves the proportions were 2 % and 7 %, respectively. There was no significant effect of milk volume on the incidence of diarrhoea.We conclude that the feeding of high volumes of milk to Jersey calves has a positive effect on growth rate, without compromising health or reducing solid feed intake after weaning. However, the higher cost of such a feeding system may limit its implementation.http://www.journals.co.za/ej/ejour_savet.htm

Physical profile of junior and senior amateur boxers

© JPES. Purpose: The purpose of this study was to profile the physiological characteristics of amateur boxers using a battery of tests designed to assess the physiological and physical demands required for performance. Fifteen junior amateur (age 14.9 ± 2.0 years; stature 164 ± 12 cm; body mass 50.9 ± 11.3 kg) and sixteen senior amateur boxers (n = 16; age 20.5 ± 4.0 years; stature 174 ± 9 cm; body mass 65.2 ± 10.7 kg) provided informed consent to participate in the study. Body composition, squat jump (SJ), countermovement jump (CMJ), 5-and 10 m sprint (5SP/10SP), press up (PU), right and left medicine-ball single-arm throws (MBR, MBL), repeated sprint test (RST) and Yo-Yo intermittent recovery test level 1 (YY) were performed. The likelihood (% chance) of between-group differences were assessed using a magnitude based approach, standardised-difference score (Cohen’s d) and 90% confidence intervals [CI]. Linear regression (r) was used to examine the association between variables. Results: Senior boxers outperformed (79 to 99% chance) junior counterparts in PU, YY, CMJ, SJ, 10SP, MBL and MBR tests (d ≥ 0.50 [-0.34 to 1.61]). There were very large (r 0.70) correlations between fat free mass, upper-and lower body lean mass and medicine ball throw distance. There were large correlations (r 0.50 to 0.69) between medicine ball throw distance and CMJ, SJ, PU, 5SP and 10SP. Conclusions: A simple and time-effective test battery was able to differentiate performance between junior and amateur boxers. These assessments could be useful when profiling junior and senior amateur boxers