The calibration of photographic and spectrographic films

Certain techniques and procedures are developed and evaluated for the ascertainment of the relative spectral-photometric characteristics of standard and special spectroscopic films and plates in the visible and UV regions. These films are used in ground based and rocket launched instruments. Two photographic spectral sensitometers were developed. One instrument is a vacuum sensitometer covering a range of 1,000 to 3,000 Angstroms and the other sensitometer is the device this investigator used to study its spectral responses in the visible region of the spectrum through the utilization of a computer microdensitometric and photometric plot and contour routines

Determination of subcritical damping by moving-block/randomdec applications

Two techniques are described which allow the determination of subcritical dampings and frequencies during aeroelastic testing of flight vehicles. The moving-block technique is shown to have the advantage of being able to provide damping and frequency information for each mode which might be present in a signal trace, but it has the disadvantage of requiring that the structure be excited transiently. The randomdec technique requires only random turbulence for excitation, but the randomdec signature is difficult to analyze when more than one mode is present. It is shown that by using the moving-block technique to analyze the randomdec signatures, the best features of both methods are gained. Examples are presented illustrating the direct application of the moving-block method to model helicopter rotor testing and application of the combined moving-block/randomdec method to flutter studies of two fixed-wing models

Application of interactive computer graphics in wind-tunnel dynamic model testing

The computer-controlled data-acquisition system recently installed for use with a transonic dynamics tunnel was described. This includes a discussion of the hardware/software features of the system. A subcritical response damping technique, called the combined randomdec/moving-block method, for use in windtunnel-model flutter testing, that has been implemented on the data-acquisition system, is described in some detail. Some results using the method are presented and the importance of using interactive graphics in applying the technique in near real time during wind-tunnel test operations is discussed

The calibration of photographic and spectroscopic films: 1: A microscopic analysis of IIaO films. 2: The effects of agitation and soaking on IIaO films. 3: The effects of electric field on IIaO films. 4: The effects of X-ray radiation on IIaO films

The grain structure of the emulsion using both reflected and transmission light was examined along with the effects of soaking. The effect of a static charge by a Tesla-coil, and the effects of airport equipment, and dental X-rays on the film were also analyzed

The calibration of photographic and spectroscopic films: The response of 2aO film to small dosages of alpha particles from 3/10th's rad to 8 rads at energy levels 153 MeV, 79 MeV and 47 MeV

The 2aO film, pre-exposed to a series of neutral density filters which on development under standard conditions will produce the standard H-D curve for that film, were then exposed to Alpha paricles with a dose range of 3/10ths rads to 8 rads while varying the energy of the particles using 153 MeV, 70 MeV, and 47 MeV, respectively. An analysis of the film shows that the 3/10th rad dose produces the lowest optical density changes at 70 MeV and 47 MeV. While the optical density readings for the darker patterns seem to oscillate and decrease when exposed to radiation dosages of 3/10th rads to 8 rads

The calibration of photographic and spectroscopic films: Reciprocity failure and thermal responses of IIaO film at liquid nitrogen temperatures

Reciprocity failure was examined for IIaO spectroscopic film. The results indicate reciprocity failure occurs at three distinct minimum points in time; 15 min, 30 min and 90 min. The results are unique because theory suggests only one minimum reciprocity failure point should occur. When incubating 70mm IIaO film for 15 and 30 min at temperatures of 30, 40, 50, and 60 C and then placing in a liquid nitrogen bath at a temperature of -190 C the film demonstrated an increase of the optical density when developed at a warm-up time of 30 min. Longer warm-up periods of 1, 2 and 3 hrs yield a decrease in optical density of the darker wedge patterns; whereas, shorter warm-up times yield an overall increase in the optical densities

IIaO ultraviolet and nuclear emulsion films responses to orbital flights on STS-3, STS-7, STS-8, and STS-40

Two types of film were flown on STS-40 space shuttle mission in June 1991. The IIaO special purpose ultraviolet film showed continued desensitization because of various thermal and cosmic ray interactions. The films were exposed to the space orbital environment for 9 days. There were several built-in launch pad delays of the shuttle mission. However, there was adequate monitoring of the temperature variations on board the shuttle that allowed for adequate knowledge of the thermal film history. This IIaO film was flown on the ASTRO I mission and is currently slated for use with the ASTRO II mission. A 50 micron thick IIIford Nuclear emulsion film was also placed on a 175 micron polyester base. The exposure to space produced several cosmic ray interactions that were analyzed and measured using Digital Image Processing techniques. This same nuclear emulsion film was flown on STS-8 and produced a similar number of cosmic ray and thermal interactions. From previous experiments of film using various laboratory electromagnetic radiation sources (e.g., alpha, beta, and neutron particles), we have been able to infer the possible oribtal interactions of both IIaO and nuclear emulsion films. The characteristic responses of IIaO on STS-40 compared favorably to the results obtained from previous STS-7 and STS-8 gas can experiments. The results indicate sufficient evidence correlating increased density on the film with possible cosmic ray, thermal and shuttle out gassing interactions

A densitometric analysis of IIaO film flown aboard the space shuttle transportation system STS-3, STS-8, and STS-7

Three canisters of IIaO film were prepared along with packets of color film from the National Geographic Society, which were then placed on the Space Shuttle #3. The ultimate goal was to obtain reasonably accurate data concerning the background fogging effects on IIaO film as it relates to the film's total environmental experience. This includes: the ground based packing, and loading of the film from Goddard Space Flight Center to Cape Kennedy; the effects of the solar wind, humidity, and cosmic rays; the Van Allen Belt radiation exposure; various thermal effect; reentry and off-loading of the film during take off, and 8 day, 3 hour 15 minutes orbits. The total densitometric change caused by all of the above factors were examined. The results of these studies have implications for the utilization of IIaO spectroscopic film on the future shuttle and space lab missions. These responses to standard photonic energy sources will have immediate application for the uneven responses of the film photographing a star field in a terrestrial or extraterrestrial environment with associated digital imaging equipment

Combined Face-Brain Morphology and Associated Neurocognitive Correlates in Fetal Alcohol Spectrum Disorders

BACKGROUND: Since the 1970s, a range of facial, neurostructural, and neurocognitive adverse effects have been shown to be associated with prenatal alcohol exposure. Typically, these effects are studied individually and not in combination. Our objective is to improve the understanding of the teratogenic effects of prenatal alcohol exposure by simultaneously considering face-brain morphology and neurocognitive measures. METHODS: Participants were categorized as control (n = 47), fetal alcohol syndrome (FAS, n = 22), or heavily exposed (HE) prenatally, but not eligible for a FAS diagnosis (HE, n = 50). Structural brain MRI images and high-resolution 3D facial images were analyzed using dense surface models of features of the face and surface shape of the corpus callosum (CC) and caudate nucleus (CN). Asymmetry of the CN was evaluated for correlations with neurocognitive measures. RESULTS: (i) Facial growth delineations for FAS, HE, and controls are replicated for the CN and the CC. (ii) Concordance of clinical diagnosis and face-based control-FAS discrimination improves when the latter is combined with specific brain regions. In particular, midline facial regions discriminate better when combined with a midsagittal profile of the CC. (iii) A subset of HE individuals was identified with FAS-like CN dysmorphism. The average of this HE subset was FAS-like in its facial dysmorphism. (iv) Right-left asymmetry found in the CNs of controls is not apparent for FAS, is diminished for HE, and correlates with neurocognitive measures in the combined FAS and HE population. CONCLUSIONS: Shape analysis which combines facial regions with the CN, and with the CC, better identify those with FAS. CN asymmetry was reduced for FAS compared to controls and is strongly associated with general cognitive ability, verbal learning, and recall in those with prenatal alcohol exposure. This study further extends the brain-behavior relationships known to be vulnerable to alcohol teratogenesis

The Coupled Electronic-Ionic Monte Carlo Simulation Method

Quantum Monte Carlo (QMC) methods such as Variational Monte Carlo, Diffusion Monte Carlo or Path Integral Monte Carlo are the most accurate and general methods for computing total electronic energies. We will review methods we have developed to perform QMC for the electrons coupled to a classical Monte Carlo simulation of the ions. In this method, one estimates the Born-Oppenheimer energy E(Z) where Z represents the ionic degrees of freedom. That estimate of the energy is used in a Metropolis simulation of the ionic degrees of freedom. Important aspects of this method are how to deal with the noise, which QMC method and which trial function to use, how to deal with generalized boundary conditions on the wave function so as to reduce the finite size effects. We discuss some advantages of the CEIMC method concerning how the quantum effects of the ionic degrees of freedom can be included and how the boundary conditions can be integrated over. Using these methods, we have performed simulations of liquid H2 and metallic H on a parallel computer.Comment: 27 pages, 10 figure