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During rapid scanning of the Apollo 15 panoramic camera photography, a peculiar feature was noted in a small patch of mare material lying between the Haemus and the Apennine Mountains. The patch is abnormal in that it is an unbordered plateau with the surface appearing to lie several hundred meters above adjacent mare patches. Significant characteristics of the feature are discussed and two panoramic camera photographs are illustrated.
Electric field data from two passes of the Injun 5 satellite, one corresponding to magnetically quiet conditions and one corresponding to substorm conditions, are compared with simultaneous all-sky-camera data from College, Alaska. In each case, a significant deviation of the electric field from the expected V x B field (where V is the satellite velocity) was evident and a distinct electric field reversal could be identified. In the region of substantial electric field equatorward of the electric field reversal a diffuse auroral arc was observed during the magnetically quiet pass and auroral patches were observed during the substorm pass. The motion of the auroral patches was consistent with the general direction and magnitude of the E x B drift computed from the satellite electric field measurements. In the substorm case the electric field reversal occurred very near a discrete auroral arc at the poleward side of the diffuse arcs and patches. Comparison of the quiet time and substorm cases suggests that the convection electric field penetrates deeper into the magnetosphere during a substorm.
This paper presents a simplified procedure for determining water current velocities and diffusion coefficients. Dye drops which form dye patches in the receiving water are made from an aircraft. The changes in position and size of the patches are recorded from two flights over the area. The data processing procedure requires that the ground coordinates about the dye patches be determined at the time of each flight. With an automatic recording coordinatograph for measuring coordinates and a computer for processing the data, this technique provides a practical method of determining circulation patterns and mixing characteristics of large aquatic systems.
A case history is presented in which the NASTRAN system provided both guidelines and working software for use in the development of a discrete element program, PATCHES-111. To avoid duplication and to take advantage of the wide spread user familiarity with NASTRAN, the PATCHES-111 system uses NASTRAN bulk data syntax, NASTRAN matrix utilities, and the NASTRAN linkage editor. Problems in developing the program are discussed along with details on the architecture of the PATCHES-111 parametric cubic modeling system. The system includes model construction procedures, checkpoint/restart strategies, and other features.
A mathematical model is developed to evaluate a number of physical effects in turbomachine blade tip contact on the basis of a broad brush approach to provide insights without undue complexity. The analysis is restricted to the case of a shoe encountering a moving blade row and pressing against it with a fixed time-average force. Relative displacement components in the contact region are identified and determined. Two key equations are derived, where it is shown that wear rate plays a strong role in determining the traversal speed of the contact patch. The formula for estimating the size of the contact patch shows that the higher the traversal speed is, the wider is the contact patch.
High resolution photographs of Phobos taken during close flybys of Viking Orbiter 1 reveal many dark patches on the floors of several craters. The apparently dark material is only prominent at large phase angles. Analysis of the photometric properties indicates that the dark patches represent areas of unusually rough textures whose reflectance near zero phase is similar to that of the mean surface (approximately 6 percent in the visible), but whose phase curve is much steeper. The contrast of such areas is less than 10 percent zero phase but approaches 100 percent near phase angles of 90 degrees. It is proposed that these intricately textured deposits represent patches of vesticular impact melt.
An analytical approach is presented for the modeling of the thermomechanical interactions which occur in high speed sliding situations. These sliding contact problems which are characterized by active and interrelated thermal and mechanical phenomena could be called 'rub energetics' problems. Analytical models were developed to simulate two different rub situations: high energy braking of disk brakes and high speed rubs of gas path seals in turbine engines. The models proved to be particularly useful in predicting the severe temperatures and deformations near hot contact patches on the rubbing surfaces. The size of the hot patches is generally determined by normal load and the properties of the contacting materials. Temperatures at the contact patches can approach the melting point of the materials, especially at high sliding velocities. These high temperatures can lead to large amounts of near-surface deformation and high wear rates. Decreased contact temperatures can result from using materials with increased thermal conductivity and increased heat capacity or choosing mechanical properties (decreased stiffness, yield stress or coefficient of thermal expansion) which give larger hot spot size.
The description of the modified code includes details of a doublet subpanel technique in which panels that are close to a velocity calculation point are replaced by a subpanel set. This treatment gives the effect of a higher panel density without increasing the number of unknowns. In particular, the technique removes the close approach problem of the earlier singularity model in which distortions occur in the detailed pressure calculation near panel corners. Removal of this problem allowed a complete wake relaxation and roll-up iterative procedure to be installed in the code. The geometry package developed for the new technique and also for the more general configurations is based on a multiple patch scheme. Each patch has a regular array of panels, but arbitrary relationships are allowed between neighboring panels at the edges of adjacent patches. This provides great versatility for treating general configurations.
A system for automatically verifying the connections between terminals of a patchboard is described. The system includes a back plane having a plurality of plugs corresponding to the pins of the patchboard. A number of decoders are connected to the plugs of the back plane so that a signal can be sequentially applied to each plug of the back plane under control of a stepping register and a control circuit. A plurality of data selectors are also connected to the plugs of the back plane and under control of a second external register. This control circuit sequentially makes connections between an output circuit and the plugs of the back plane so as to patch the signal applied to a respective plug through a patch connection to the output circuit. The precise locations of the patches on the patchboard can be identified and compared with previously stored information in a memory unit.
The cutaneous primary irritancy and allergenicity potential of cotton shirts/fabrics treated with flame retardants were evaluated in order to establish their suitability for spacecraft crew use. Twenty-five volunteer human subjects were patch tested on the back utilizing standard methodology, with both treated and untreated cotton fabric. The fabric was treated with tetrakis (hydroxymethyl) phosphonium hydroxide and subsequently cured with gaseous ammonia. The final treatment comprised adding on dicyandiamine phosphoric acid. None of the individuals experienced primary irritant or allergic reactions attributable to the fabric during induction or challenge patch testing. Likewise, there were no reactions to treated or untreated fabric patches placed on ten subjects of the usage panel at the conclusion of the study.
An idea, due to A. Feiveson, is presented for relaxing the assumption of class conditional independence of LANDSAT spectral measurements within the same patch (field). Theoretical arguments are given which show that any significant refinement of the model beyond Feiveson's proposal will not allow the reduction, essential to HISSE, of the pure data to patch summary statistics. A slight alteration of the new model is shown to be a reasonable approximation to the model which describes pure data elements from the same patch as jointly Guassian with a covariance function which exhibits exponential decay with respect to spatial separation.
A method for relaxing the assumption of class conditional independence of LANDSAT spectral measurements within the same patch (field) is discussed. Theoretical arguments are given which show that any significant refinement of the model beyond this proposal will not allow the reduction, essential to HISSE, of the pure data to patch summary statistics. A slight alteration of the new model is shown to be a reasonable approximation to the model which describes pure data elements from the same patch as jointly Gaussian with a covariance function which exhibits exponential decay with respect to spatial separation.
The work on rectangular microstrip antennas for dual frequency operation is reported on. The principle of this approach is based on the excitation of a patch for two or more different modes which correspond to different frequencies. However, for a given geometry, the modal frequencies have a fixed relationship; therefore, the usefulness of such a design is greatly limited. In this study three different methods have been contrived to control the frequency ratio over a wide range. First, as found prevously, if shorting pins are inserted at certain locations in the patch, the low frequency can be raised substantially. Second, if slots are cut in the patch, the high frequency can be lowered considerably. By using both techniques, the two frequency ratio can be varied approximately from 3 to 1.3. After that, the addition of more pins or slots becomes ineffective.
Patches and easy-to-use tools yield pressure-tight seal. Repairer lifts patch from repair kit with hook-and-pile-tipped tool and positions it over puncture hole. With tool, even gloved repairer easily manipulates patch without damaging it.
A technique is presented for measuring ocean wave directional spectra from aircraft using microwave Doppler radar. The technique involves backscattering coherent microwave radiation from a patch of sea surface which is small compared to dominant ocean wavelengths in the antenna look direction, and large compared to these lengths in the perpendicular (azimuthal) direction. The mean Doppler shift of the return signal measured over short time intervals is proportional to the mean sea surface velocity of the illuminated patch. Variable sea surface velocities induced by wave motion therefore produce time-varying Doppler shifts in the received signal. The large azimuthal dimension of the patch implies that these variations must be produced by surface waves traveling near the horizontal antenna look direction thus allowing determination of the direction of wave travel. Linear wave theory is used to convert the measured velocities into ocean wave spectral densities. Spectra measured simultaneously with this technique and two laser profilometers, and nearly simultaneous with this technique and two laser profilometers, and nearly simultaneous with a surface buoy, are presented. Applications and limitations of this airborne Doppler technique are discussed.
Detailed experimental results on microstrip antennas consisting of one center-fed patch and several identical parasitic patches are presented. The effects of the number of elements and interelement spacing are studied for two configurations: a linear array and a five-element array. It is shown that placing identical parasitic elements adjacent to a fed patch permits broadside radiation patterns with significant enhancement in gain to be obtained without any degradation of the pattern characteristics.
High-resolution in situ Dynamics Explorer 2 data on thermal plasma densities are used here to study the small-scale irregularity structure of the F layer patches. It is shown that spatially discrete density structures associated with polar cap patches can be detected fairly high in the topside by an in situ irregularity sensor and that they correspond to temporally discrete scintillation patches. It is also shown that it is possible to model phase and amplitude scintillation occurrence from a knowledge of irregularity amplitude at a satellite altitude of about 800 km provided that independent measurements of the peak density and scale height of the F region are available.
Patched-grid algorithms for the analysis of complex configurations with an implicit, upwind-biased Navier-Stokes solver were investigated. Conservative and non-conservative approaches for performing zonal interpolations were implemented. The latter approach yields the most flexible technique in that it can handle both patched and overlaid grids. Results for a two-dimensional blunt body problem show that either approach yield accurate steady-state shock locations and jump conditions. In addition, calculations of the turbulent flow through a hypersonic inlet on a three-zone grid show that the numerical prediction is in good agreement with the experimental results. Through the use of a generalized coordinate transformation at the zonal interface between two or more blocks, the algorithm can be applied to highly stretched viscous grids and to arbitrarily-shaped zonal boundaries. Applications were made to the F-18 aircraft at subsonic, high-alpha conditions, in support of the NASA High-Alpha Research Program. The calculations were compared to ground-based and flight test experiments and were used as a guide to understanding the ground-based tests, which are laminar and transitional, and their relationship to flight. Calculations about a complete reconnaissance aircraft were also performed in order to further demonstrate the capability of the patched-grid algorithm.