Injection of a drag-reducing fluid into turbulent pipe flow of a Newtonian fluid

Injection of drag reducing fluid into turbulent pipe flow of Newtonian flui

Study of the mechanics of non-Newtonian fluids Final report, 26 Jun. 1963 - 26 Dec. 1968

Aspects of mechanics of nonNewtonian fluid

Effects of spiral longitudinal vortices on turbulent boundary layer skin friction

Effect of spiral longitudinal vortices on turbulent boundary layer skin frictio

Mars - the analysis of the mars data and the absolute rate of energy loss of muons in iron

The method by which the data from the new Durham cosmic ray muon spectrograph, MAES, are analysed by the on-line computer is described in detail. Particular reference is made to a new computer technique which has been developed for the analysis of flash-tube data and an attempt has been made to reconcile experiment and theory. It is concluded that the technique correctly interprets the flash-tube data, especially with regard to extraneously discharged and inefficient tubes, and that its accuracy is sufficient to enable the cosmic ray muon momentum spectrum to be determined by MABS to beyond 5000 GeV/c. Details of a preliminary measurement of the vertical muon momentum spectrum and charge ratio for the momentum range of 10 - 500 GeV/c are given. Satisfactory agreement is found between these results and those of previous workers. An experiment is described by which a direct measurement of the absolute rate of energy loss of muons in iron for the momentum range 5-40 &eV/c has been made. Agreement is found with the predictions of Sternheimer and Peierls for ionisation loss (together with values for other losses) to within the experimental uncertainties. As such, this experiment is a measurement of the rate of energy loss in a momentum range not previously studied by a direct technique

Causal Classical Theory of Radiation Damping

It is shown how initial conditions can be appropriately defined for the integration of Lorentz-Dirac equations of motion. The integration is performed \QTR{it}{forward} in time. The theory is applied to the case of the motion of an electron in an intense laser pulse, relevant to nonlinear Compton scattering.Comment: 8 pages, 2 figure

Origins of NASA names

Names are selected for NASA spaceflight projects and programs from various sources. Some have their foundations in mythology and astrology or legend and folklore. Some have historic connotations; others are based on a description of their mission, often resulting in an acronym. Included are names of launch vehicles, spacecraft, manned spaceflight programs, sounding rockets, and NASA field installations. This study is limited to names of approved projects through 1974; it does not include names of numerous projects which have been or are being studied or projects that were canceled or postponed before reaching actual flight

How much dystrophin is enough: the physiological consequences of different levels of dystrophin in the mdx mouse

Splice modulation therapy has shown great clinical promise in Duchenne muscular dystrophy, resulting in the production of dystrophin protein. Despite this, the relationship between restoring dystrophin to established dystrophic muscle and its ability to induce clinically relevant changes in muscle function is poorly understood. In order to robustly evaluate functional improvement, we used in situ protocols in the mdx mouse to measure muscle strength and resistance to eccentric contraction-induced damage. Here, we modelled the treatment of muscle with pre-existing dystrophic pathology using antisense oligonucleotides conjugated to a cell-penetrating peptide. We reveal that 15% homogeneous dystrophin expression is sufficient to protect against eccentric contraction-induced injury. In addition, we demonstrate a >40% increase in specific isometric force following repeated administrations. Strikingly, we show that changes in muscle strength are proportional to dystrophin expression levels. These data define the dystrophin restoration levels required to slow down or prevent disease progression and improve overall muscle function once a dystrophic environment has been established in the mdx mouse model

Development of dynamic calibration methods for POGO pressure transducers

Two dynamic pressure sources are described for the calibration of pogo pressure transducers used to measure oscillatory pressures generated in the propulsion system of the space shuttle. Rotation of a mercury-filled tube in a vertical plane at frequencies below 5 Hz generates sinusoidal pressures up to 48 kPa, peak-to-peak; vibrating the same mercury-filled tube sinusoidally in the vertical plane extends the frequency response from 5 Hz to 100 Hz at pressures up to 140 kPa, peak-to-peak. The sinusoidal pressure fluctuations can be generated by both methods in the presence of high pressures (bias) up to 55 MPa. Calibration procedures are given in detail for the use of both sources. The dynamic performance of selected transducers was evaluated using these procedures; the results of these calibrations are presented. Calibrations made with the two sources near 5 Hz agree to within 3% of each other

A dynamic pressure source for the calibration of pressure transducers

A dynamic pressure source is described for producing sinusoidally varying pressures of up to 34 kPa zero to peak, over the frequency range of approximately 50 Hz to 2 kHz. The source is intended for the dynamic calibration of pressure transducers. The transducer to be calibrated is mounted near the base of the thick walled aluminum tube forming the vessel so that the pressure sensitive element is in contact with the liquid in the tube. A section of the tube is filled with small steel balls to damp the motion of the 10-St dimethyl siloxane working fluid in order to extend the useful frquency range to higher frequencies than would be provided by an undamped system. The dynamic response of six transducers provided by the sponsor was evaluated using the pressure sources; the results of these calibrations are given