M-1 engine test complex data acquisition systems

Instrumentation and data acquisition system for development testing of liquid hydrogen/liquid oxygen M-1 rocket engin

The ground state and the long-time evolution in the CMC Einstein flow

Let (g,K)(k) be a CMC (vacuum) Einstein flow over a compact three-manifold M with non-positive Yamabe invariant (Y(M)). As noted by Fischer and Moncrief, the reduced volume V(k)=(-k/3)^{3}Vol_{g(k)}(M) is monotonically decreasing in the expanding direction and bounded below by V_{\inf}=(-1/6)Y(M))^{3/2}. Inspired by this fact we define the ground state of the manifold M as "the limit" of any sequence of CMC states {(g_{i},K_{i})} satisfying: i. k_{i}=-3, ii. V_{i} --> V_{inf}, iii. Q_{0}((g_{i},K_{i}))< L where Q_{0} is the Bel-Robinson energy and L is any arbitrary positive constant. We prove that (as a geometric state) the ground state is equivalent to the Thurston geometrization of M. Ground states classify naturally into three types. We provide examples for each class, including a new ground state (the Double Cusp) that we analyze in detail. Finally consider a long time and cosmologically normalized flow (\g,\K)(s)=((-k/3)^{2}g,(-k/3))K) where s=-ln(-k) is in [a,\infty). We prove that if E_{1}=E_{1}((\g,\K))< L (where E_{1}=Q_{0}+Q_{1}, is the sum of the zero and first order Bel-Robinson energies) the flow (\g,\K)(s) persistently geometrizes the three-manifold M and the geometrization is the ground state if V --> V_{inf}.Comment: 40 pages. This article is an improved version of the second part of the First Version of arXiv:0705.307

Experimental tests of relativistic gravitation theories

Experimental tests were studied for determining the potential uses of future deep space missions in studies of relativistic gravity. The extensions to the parametrized post-Newtonian framework to take explicit account of the solar system's center of mass relative to the mean rest frame of the Universe is reported. Discoveries reported include the Machian effects of motion relative to the universal rest frame. Summaries of the JPL research are included

Evaluation of postural mechanisms under dynamic conditions

A stimulus delivery and data acquisition system for assessment of human posture was developed based on a digital computer and a translating platform. The movement of the platform acts to displace the subject's base of support while the computer tracks the corrections which are made by the subject to maintain balance. Various stimuli are used ranging from fast transients to sine waves

Development of methodologies for vestibular experimentation with man and animals

Calculations on the possibilities for an animal centrifuse which will be useful in the study of the otolith organs in space research are presented with discussion on the design of such a centrifuse

Determination of the masses of the Moon and Venus and the astronomical unit from radio tracking data of the Mariner II SPACECRAFT

Masses of Venus and Moon, and astronomical unit determined by Mariner II radio tracking dat

A Mission to Test the Pioneer Anomaly

Analysis of the radio tracking data from the Pioneer 10/11 spacecraft has consistently indicated the presence of an anomalous small Doppler frequency drift. The drift can be interpreted as being due to a constant acceleration of a_P= (8.74 +/- 1.33) x 10^{-8} cm/s^2 directed towards the Sun. Although it is suspected that there is a systematic origin to the effect, none has been found. The nature of this anomaly has become of growing interest in the fields of relativistic cosmology, astro- and gravitational physics as well as in the areas of spacecraft design and high-precision navigation. We present a concept for a designated deep-space mission to test the discovered anomaly. A number of critical requirements and design considerations for such a mission are outlined and addressed.Comment: Final changes for publication. Honorable Mention, 2002 Gravity Research Foundation Essay

Numerical solution of flowfields behind rectangular wings

The numerical solution of flow fields behind rectangular wings is described. Subjects discussed are: (1) evaluation of various differencing methods applied to the hyperbolic partial differential equations encountered in gas dynamics, (2) application of the numerical differencing techniques to the wedge flow, two dimensional shock reflection for the three dimensional finite thickness wing at zero degrees angle of attack, and (3) calculation of preliminary results for wedge flows using optimum differencing methods

A case study of effective practice in mathematics teaching and learning informed by Valsiner’s zone theory

The characteristics that typify an effective teacher of mathematics and the environments that support effective teaching practices have been a long-term focus of educational research. In this article we report on an aspect of a larger study that investigated ‘best practice’ in mathematics teaching and learning across all Australian states and territories. A case study from one Australian state was developed from data collected via classroom observations and semi-structured interviews with school leaders and teachers and analysed using Valsiner’s zone theory. A finding of the study is that ‘successful’ practice is strongly tied to school context and the cultural practices that have been developed by school leaders and teachers to optimise student learning opportunities. We illustrate such an alignment of school culture and practice through a vignette based on a case of one ‘successful’ school