820 research outputs found
In Girum (version/round 1.3, 2008) – Dir. Nick Cope: Video/DVD in collaboration with Composer Tim Howle, 6’05”. Awards: Abstracta International Abstract Cinema Exhibition, Rome, August 2009 – Honourable Mention of the Jury.
Short film/video exploring the encounter of electroacoustic music composition and moving image practice
Laser Doppler velocimeter aerial spray measurements
An experimental research program for measuring the location, spatial extent, and relative concentration of airborne spray clouds generated by agricultural aircraft is described. The measurements were conducted with a ground-based laser Doppler velocimeter. The remote sensing instrumentation, experimental tests, and the results of the flight tests are discussed. The cross section of the aerial spray cloud and the observed location, extent, and relative concentration of the airborne particulates are presented. It is feasible to use a mobile laser Doppler velocimeter to track and monitor the transport and dispersion of aerial spray generated by an agricultural aircraft
High speed lookup table approach to radiometric calibration of multispectral image data
A concept for performing radiometric correction of multispectral image data onboard a spacecraft at very high data rates is presented and demonstrated. This concept utilized a lookup table approach, implemented in hardware, to convert the raw sensor data into the desired corrected output data. The digital lookup table memory was interfaced to a microprocessor to allow the data correction function to be completely programmable. Sensor data was processed with this approach at rates equal to the access time of the lookup table memory. This concept offers flexible high speed data processing for a wide range of applications and will benefit from the continuing improvements in performance of digital memories
A selected ion flow tube study of the reactions of gas-phase cations with PSCl3
A selected ion flow tube was used to investigate the positive ion chemistry of thiophosphoryl chloride, PSCl. Rate coefficients and ion product branching ratios have been determined at room temperature for reactions with nineteen cations ; HO, CF, CF, NO, NO, SF, SF, CF, O, HO, NO, O, CO, CO, N, N, Ar, F and Ne (in order of increasing recombination energy). Complementary data described in the previous paper have been obtained for this molecule via the observation of threshold photoelectron photoion coincidences. For ions whose recombination energies are in the range 10-22 eV, comparisons are made between the product ion branching rations of PSCl from photoionisation and from ion-molecule reactions. In most instances, the data from the two experiments are well correlated, suggesting that long-range charge transfer is the dominant mechanism for these ion-molecule reactions ; the agreement is particularly good for the atomic ions Ar, F and Ne. Some reactions (e.g. O + PSCl), however, exhibit significant differences; short-range charge transfer must then be occurring following the formation of an ion-molecule complex. For ions whose recombination energies are less than 10 eV (i.e. HO, CF, CF and NO), reactions can only occur via a chemical process in which bonds are broken and formed, because the recombination energy of the cation is less than the ionisation energy of PSCl
Preliminary design for a standard 10 sup 7 bit Solid State Memory (SSM)
A modular concept with three separate modules roughly separating bubble domain technology, control logic technology, and power supply technology was employed. These modules were respectively the standard memory module (SMM), the data control unit (DCU), and power supply module (PSM). The storage medium was provided by bubble domain chips organized into memory cells. These cells and the circuitry for parallel data access to the cells make up the SMM. The DCU provides a flexible serial data interface to the SMM. The PSM provides adequate power to enable one DCU and one SMM to operate simultaneously at the maximum data rate. The SSM was designed to handle asynchronous data rates from dc to 1.024 Mbs with a bit error rate less than 1 error in 10 to the eight power bits. Two versions of the SSM, a serial data memory and a dual parallel data memory were specified using the standard modules. The SSM specification includes requirements for radiation hardness, temperature and mechanical environments, dc magnetic field emission and susceptibility, electromagnetic compatibility, and reliability
Threshold photoelectron photoion coincidence spectroscopy of trichloroethene and tetrachloroethene
The threshold photoelectron, the threshold photoelectron photoion coincidence and ion breakdown spectra of trichloroethene and tetrachloroethene have been recorded from 9 – 22 eV. Comparisons with the equivalent data for the three dichloroethene molecules and theoretical calculations highlight the nature of the orbitals involved during photoionisation in this energy range. The ground electronic state of CHCl (CCl) is bound, with excited valence states dissociating to CHCl (CCl) and CHCl (CCl). Appearance energies suggest that CHCl forms from CHCl by loss of two chlorine atoms, whereas CCl forms from CCl by loss of a Cl molecule. The translational kinetic energy release into CHCl (CCl) + Cl is determined as a function of energy. In both cases, the fraction of the available energy released into translational energy of the two products decreases as the photon energy increases
The photoionization dynamics of the three structural isomers of dichloroethene
Using tunable vacuum-UV radiation from a synchrotron, the threshold photoelectron spectrum, threshold photoelectron photoion coincidence spectrum and ion breakdown diagram of the 1,1, cis-1,2 and trans-1,2 isomers of CHCl have been recorded in the range 9-23 eV. The energies of the peaks in the threshold photoelectron spectrum are in good agreement with outer-valence Greens function caculations. The major difference between the isomers, both predicted and observed experimentally is that the F and G states of CHCl are approximately degenerate for 1,1 and trans-1,2, but well separated for the cis-1,2 isomer. The ground and low-lying valence states of CHCl are bound, with higher-lying states dissociating to CHCl or CH. The translational kinetic energy release into CHCl + Cl is determined as a function of energy. Isolated-state behaviour for the low-lying electronic states of CHCl becomes more statistical as the energy increases
Remote measurement utilizing NASA's scanning laser Doppler systems. Volume 2: Laser Doppler dust devil velocity profile measurement program
The first detailed velocity profile data on thermally induced dust vortices are presented. These dust devils will be analyzed and studied to determine their flow fields and origin in an effort to correlate this phenomena with the generation and characteristics of tornadoes. A continuing effort to increase mankind's knowledge of vortex and other meteorological phenomena will hopefully allow the prediction of tornado occurrence, their path, and perhaps eventually even lead to some technique for their destruction
Effect of varying injection rates of a saline chaser on aortic enhancement in CT angiography: phantom study
The effect of varying injection rates of a saline chaser on aortic enhancement in computed tomography (CT) angiography was determined. Single-level, dynamic CT images of a physiological flow phantom were acquired between 0 and 50 s after initiation of contrast medium injection. Four injection protocols were applied with identical contrast medium administration (150ml injected at 5ml/s). For baseline protocol A, no saline chaser was applied. For protocols B, C, and D, 50ml of saline was injected at 2.5ml/s, 5ml/s, and 10ml/s, respectively. Injecting the saline chaser at twice the rate as the contrast medium yielded significantly higher peak aortic enhancement values than injecting the saline at half or at the same rate as the contrast medium (P 0.05). In CT angiography, saline chaser injected at twice the rate as the contrast medium leads to increased peak aortic enhancement and saline chaser injected at half the rate tends towards prolonging peak aortic enhancement platea
Femtosecond-laser pumped CdSiP<sub>2</sub> optical parametric oscillator producing 100 MHz pulses centered at 6.2 μm
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