54,170 research outputs found
BANDIT in NASTRAN
BANDIT has been implemented into the NASTRAN April '83 release. It is now a permanent feature in NASTRAN and will be included in all future releases for all four computing machines (IBM, CDC, UNIVAC, and VAX). Originally BANDIT operated as a preprocessor of NASTRAN. It read the NASTRAN input cards and produced a set of resequencing (SEOGP) cards that would greatly reduce the computational time required by the matrix decomposition module of NASTRAN for a large structure. In the past, many computer centers had installed BANDIT in their systems together with the NASTRAN program. The user would run the BANDIT program and NASTRAN as if they were one program (or two separated programs depending on how the two programs were actually tied together in the computer systems). In some cases, the user was required to pass the input cards and the output SEQGP cards between the two programs, and n others, the data was manipulated through the use of cataloged disc files. Although there is nothing wrong with this BANDIT-NASTRAN arrangement, there are, however, several shortcomings which are mentioned in this paper. The BANDIT in the NASTRAN April '83 release has removed all the deficiencies, and it comes in one version applicable to the four computing machines
COSMIC/NASTRAN Free-field Input
A user's guide to the COSMIC/NASTRAN free field input for the Bulk Data section of the NASTRAN program is proposed. The free field input is designed to be user friendly and the user is not forced out of the computer system due to input errors. It is easy to use, with only a few simple rules to follow. A stand alone version of the COSMIC/NASTRAN free field input is also available. The use of free field input is illustrated by a number of examples
The motion of a deformable drop in a second-order fluid
The cross-stream migration of a deformable drop in a unidirectional shear flow of a second-order fluid is considered. Expressions for the particle velocity due to the separate effects of deformation and viscoelastic rheology are obtained. The direction and magnitude of migration are calculated for the particular cases of Poiseuille flow and simple shear flow and compared with experimental data
Design and application of gas-gap heat switches
Gas-gap heat switches can serve as an effective means of thermally disconnecting a standby cryocooler when the primary (operating) cooler is connected and vice versa. The final phase of the development and test of a cryogenic heat switch designed for loads ranging from 2 watts at 8 K, to 100 watts at 80 K are described. Achieved heat-switch on/off conductance ratio ranged from 11,000 at 8 K to 2200 at 80 K. A particularly challenging element of heat-switch design is achieving satisfactory operation when large temperatures differentials exist across the switch. A special series of tests and analyses was conducted and used in this Phase-2 activity to evaluate the developed switches for temperature differentials ranging up to 200 K. Problems encountered at the maximum levels are described and analyzed, and means of avoiding the problems in the future are presented. A comprehensive summary of the overall heat-switch design methodology is also presented with special emphasis on lessons learned over the course of the 4-year development effort
New Enhancements in April 85 NASTRAN Release
Several features were added to COSMIC NASTRAN, along with some enhancements to improve or update existing capabilities. Most of these additions and enhancements were provided by industry users to be incorporated into NASTRAN for wider use. DIAG 48 provides a synopsis of significant developments in past NASTRAN releases (1983-1985) and indexes all diagnostic output messages and operation requests (DOMOR). Other features include: volume and surface computation of the 2-D and 3-D elements, NOLIN5 input and; NASTRAN PLOTOPT-N (where N = 2, 3, 4, or 5); shrink element plots; and output scan. A nonprint option on stress and force output request cards was added. Automated find and nofind options on the plot card, fully stressed design, high level plate elements, eigenvalue messages, and upgrading of all FORTRAN source code to the ANSI standard are enhancements made
The effects of man-marking on work intensity in small-sided soccer games
The aim of this study was to examine the effect of manipulating defensive rules: with and without man-marking (MM and NMM) on exercise intensity in 3 vs. 3 small-sided games (SSGs). Twelve adolescent soccer players (age: 16.2 ± 0.7 years; body mass: 55.7 ± 6.4 kg; body height: 1.70 ± 0.07 m) participated in this repeated measures study. Each participant performed in four different SSGs formats: 3 vs. 3 MM with and without goals and 3 vs. 3 NMM with and without goals. Each SSG lasted 3 x 4 minutes interspersed with 4 minutes passive recovery. The percentage heart rate reserve (%HRreserve) was recorded continuously during SSG and session-rating of perceived exertion (session-RPE) after the SSG. MANOVA showed that defensive rule had significant effects on intensity (F = 5.37, p < 0.01). Specifically, MM during SSG induced significantly higher %HRreserve compared to NMM (Goal: 80.5 vs. 75.7%; No goal: 80.5 vs. 76.1%; p < 0.05, effect size = 0.91-1.06), irrespective of the presence or absence of goals. However, only MM with the presence of goals induced significant higher session-RPE compared to NMM (7.1 vs. 6.0; p < 0.05, effect size = 1.36), whereas no difference in session-RPE was observed
between MM and NMM (7.4 vs. 6.9; p > 0.05, effect size
= 0.63) when no goals were used. Higher intra-class reliability and lower coefficient of variation values were also reported in MM as compared to NMM. This study in youth soccer players shows there is ~4.5% increase in heart rate response by using the man-marking in 3 vs. 3 SSG thus the intensity of SSG can be significantly increased when using man-marking tactics
Cosmological Constraints on Radion Evolution in the Universal Extra Dimension Model
The constraints on the radion evolution in the Universal Extra Dimension
(UED) model from Cosmic Microwave Background (CMB) and Type Ia supernovae (SNe
Ia) data are studied. In the UED model, where both the gravity and standard
model fields can propagate in the extra dimensions, the evolution of the extra
dimensional volume, the radion, induces variation of fundamental constants. We
discuss the effects of variation of the relevant constants in the context of
UED for CMB power spectrum and SNe Ia data. We then use the three-year WMAP
data to constrain the radion evolution at z \sim 1100, and the 2 \sigma
constraint on \dot{\rho} / \rho_0 (\rho is a function of the radion, to be
defined in the text) is [ -8.8, 6.6] \times 10 ^{-13} yr^-1. The SNe Ia gold
sample yields a constraint on \dot{\rho} / \rho_0, for redshift between 0 and
1, to be [-4.7, 14] \times 10^{-13} yr^-1. Furthermore, the constraints from
SNe Ia can be interpreted as bounds on the evolution QCD scale parameter,
\dot{\Lambda}_{QCD} / \Lambda_{QCD, 0}, [-1.4, 2.8] \times 10^{-11} yr^-1,
without reference to the UED model.Comment: 8 pages, 3 figures, comments added, to appear in Phys. Rev.
Electric field induced charge noise in doped silicon: ionization of phosphorus donors
We report low frequency charge noise measurement on silicon substrates with
different phosphorus doping densities. The measurements are performed with
aluminum single electron transistors (SETs) at millikelvin temperatures where
the substrates are in the insulating regime. By measuring the SET Coulomb
oscillations, we find a gate voltage dependent charge noise on the more heavily
doped substrate. This charge noise, which is seen to have a 1/f spectrum, is
attributed to the electric field induced tunneling of electrons from their
phosphorus donor potentials.Comment: 4 page, 3 figure
- …