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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The research concerned with the liaison, interface, coupling, and technology transfer processes that occur in research and development is reported. Overviews of the functions of communication and coupling in the R and D processes, and the theoretical considerations of coupling, communication, and values are presented along with descriptions of the field research program and the instrumentation.
The question of radiation scales is critically examined. There are two radiation scales which are of fundamental validity and there are several calibration standards and radiation scales which have been set up for practical convenience. The interrelation between these scales is investigated. It is shown that within the limits of accuracy of irradiance measurements in general and solar irradiance measurements in particular, the proposed standard values of the solar constant and solar spectrum should be considered to be on radiation scales of fundamental validity; those based on absolute electrical units and on the thermodynamic Kelvin temperature scale.
Decision makers within Governmental agencies and Congress must evaluate competing (and sometimes conflicting) proposals which seek funding and implementation. Present value analysis can be an effective decision making tool by enabling the formal evaluation of the effects of competing proposals on efficient national resource utilization. A project's costs are not only its direct disbursements, but its social costs as well. How much does it cost to have those funds diverted from their use and economic benefit by the private sector to the public project? Comparisons of competing projects' social costs allow decision makers to expand their decision bases by quantifying the projects' impacts upon the economy and the efficient utilization of the country's limited national resources. A conceptual model is established for the choosing of the appropriate discount rate to be used in evaluation decisions through the technique.
Provisional hourly values of equatorial atmospheric radiation conditions for the period January to June 1972 were obtained. The data are presented in numerical tables with graphical presentation of the digital data included.
Color excesses in B-V are determined indirectly from a study of Stromgren's b-y color for a sample of F0 - K5 supergiants. The resulting E(B-V)'s are estimated to have an expected precision of + or - 0.05. With the calculated color excesses and the observed values of B-V given in various catalogs, the run of B-V with spectral type is obtained. This B-V/(spectral type) relationship is compared with those found previously by other investigators.
A general theory of spherically symmetric boundary-value problems of the one-speed neutron transport theory is presented. The formulation is also applicable to the 'gray' problems of radiative transfer. The Green's function for the purely absorbing medium is utilized in obtaining the normal mode expansion of the angular densities for both interior and exterior problems. As the integral equations for unknown coefficients are regular, a general class of reduction operators is introduced to reduce such regular integral equations to singular ones with a Cauchy-type kernel. Such operators then permit one to solve the singular integral equations by the standard techniques due to Muskhelishvili. We discuss several spherically symmetric problems. However, the treatment is kept sufficiently general to deal with problems lacking azimuthal symmetry. In particular the procedure seems to work for regions whose boundary coincides with one of the coordinate surfaces for which the Helmholtz equation is separable.
The value of space exploration in relation to such earth bound problems as poverty, hunger, overpopulation, pollution, disease, and urban blight is discussed.
Tables of provisional hourly values of equatorial Dst for July, August, and September 1972 are presented.
A parametric study of low-boom supersonic transport airplanes with conventional configurations was made to identify the features of specific configurations that promise relatively low sonic boom overpressures (less than 47.9 N/sq m). The range of values considered was gross weight from 28,300 to 170,000 kg; cruise Mach numbers of 2 to 3.2; and wing loadings of 1436, 2870, and 4309 N/sq m. Fuselage length was varied from 49.1 to 102.4 m and fuselage diameter from 2.75 to 3.98 m. A nominal Mach 2 configuration weighing 56,700 kg and having a wing loading of 2870 N/sq m was selected; and its gross geometric, aerodynamic, and structural features were estimated. At a cruise altitude of 18,300 m, lift-drag ratio was estimated to be 7.35, while sonic boom overpressure was 41.7 N/sq m. Takeoff thrust loading using four afterburning turbojet engines at maximum dry thrust was 0.32. Payload for a 4440-km range was 16.7 percent of gross weight, giving a direct operating cost of 0.82 cent per seat statute mile.
The three advanced propulsion systems analyzed are an advanced chemical system, an improved solid-core nuclear rocket engine with a 25-kilowatt auxiliary powerplant, and a nuclear-electric system. The comparison of these systems is made on the basis of transportation cost divided by the expected value of the data returned to earth. The analysis shows that for the Mercury Orbiter mission and for missions to the outer planets with a high data requirement, the nuclear-electric system emerges as the best system. For the Venus Orbiter mission, the advanced chemical propulsion system is best.
A solution is obtained for the geodetic boundary value problem which defines height anomalies to + or - 5 cm, if the earth were rigid. The solution takes into account the existence of the earth's topography, together with its ellipsoidal shape and atmosphere. A relation is also established between the commonly used solution of Stokes and a development correct to order e cubed. The data requirements call for a complete definition of gravity anomalies at the surface of the earth and a knowledge of elevation characteristics at all points exterior to the geoid. In addition, spherical harmonic representations must be based on geocentric rather than geodetic latitudes.
Tables covering provisional hourly values of equatorial Dst for November and December 1972 are presented.
Previously published asymptotic solutions for lunar and interplanetery trajectories have been modified and combined to formulate a general analytical solution to the problem of N-bodies. The earlier first-order solutions, derived by the method of matched asymptotic expansions, have been extended to second order for the purpose of obtaining increased accuracy. The complete derivation of the second-order solution, including the application of a regorous matching principle, is given. It is shown that the outer and inner expansions can be matched in a region of order mu to the alpha power, where 2/5 alpha 1/2, and mu (the moon/earth or planet/sun mass ratio) is much less than one. The second-order asymptotic solution has been used as a basis for formulating a number of analytical two-point boundary value solutions. These include earth-to-moon, one- and two-impulse moon-to-Earth, and interplanetary solutions. Each is presented as an explicit analytical solution which does not require iterative steps to satisfy the boundary conditions. The complete derivation of each solution is shown, as well as instructions for numerical evaluation. For Vol. 1, see N73-27738.
The research accomplished during this period is reported. Published abstracts and technical reports are listed. Articles presented include: boundedness of absolute values of generalized Fourier coefficients, propagation in stochastic media, and stationary conditions for stochastic differential equations.
The question of the considerable variations in various blood parameters under the influence of changes in environmental factors is discussed. Recommendations are given that so-called normal values should be given special attention. Fibrinolytic and fibrinogenolytic activity studies on the blood in healthy human beings revealed significant differences for individual months and even on specific days. Changes in the activity of fibrinolysis and fibrinogenolysis show a correlation with changes in the meteorological conditions, seasonal variations and changes in solar activity.
Background information is provided which emphasizes the philosophy behind analytical techniques used in the business risk and value of operations in space (BRAVO) study. The focus of the summary is on the general approach, operation of the procedures, and the status of the study. For Vol. 1, see N74-12493; for Vol. 2, see N74-14530.
Transition probabilities for 14 lines of Fe II and 12 lines of Fe I in the wavelength region 2560-2737 A were measured by use of a shock tube and the hook method. Absolute oscillator strengths for resonance lines of Fe I reported by Banfield and Huber were used to determine the number density of neutral iron in the shock-heated gas. With the assumption of thermal equilibrium, the density of singly ionized iron atoms in this gas was then computed from the measured temperature and pressure with the aid of the Saha equation. Our results on the 12 strongest of the 13 lines belonging to the first ultraviolet multiplet of Fe II indicate that the multiplet f-value is larger by a factor of 2 than that derived from lifetime measurements by Assousa and Smith.
This study investigates the use of Green's functions in the numerical solution of the two-point boundary value problem. The first part deals with the role of the Green's function in solving both linear and nonlinear second order ordinary differential equations with boundary conditions and systems of such equations. The second part describes procedures for numerical construction of Green's functions and considers briefly the conditions for their existence. Finally, there is a description of some numerical experiments using nonlinear problems for which the known existence, uniqueness or convergence theorems do not apply. Examples here include some problems in finding rendezvous orbits of the restricted three body system.